EP1977097B1 - Improvements to an engine with variable volumetric ratio - Google Patents

Improvements to an engine with variable volumetric ratio Download PDF

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Publication number
EP1977097B1
EP1977097B1 EP07701584A EP07701584A EP1977097B1 EP 1977097 B1 EP1977097 B1 EP 1977097B1 EP 07701584 A EP07701584 A EP 07701584A EP 07701584 A EP07701584 A EP 07701584A EP 1977097 B1 EP1977097 B1 EP 1977097B1
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EP
European Patent Office
Prior art keywords
crankshaft
cylinder
engine
cylinders
stroke
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EP07701584A
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German (de)
French (fr)
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EP1977097A1 (en
Inventor
Gilbert Lucien Charles Henri Louis Van Avermaete
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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
    • F02B75/00—Other engines
    • F02B75/16—Engines characterised by number of cylinders, e.g. single-cylinder engines
    • F02B75/18—Multi-cylinder engines
    • F02B75/22—Multi-cylinder engines with cylinders in V, fan, or star arrangement
    • F02B75/225—Multi-cylinder engines with cylinders in V, fan, or star arrangement having two or more crankshafts
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02D—CONTROLLING COMBUSTION ENGINES
    • F02D15/00—Varying compression ratio
    • F02D15/04—Varying compression ratio by alteration of volume of compression space without changing piston stroke

Definitions

  • the object of the invention consists in regulating the force of the engine torque between two crankshafts of a variable volumetric ratio engine, as well as the arrangement of a combustion chamber in groups of two cylinders.
  • the present invention relates to the arrangement of the variable-pitch transmission of a variable volumetric ratio engine to improve the control device of the phase angle between a first and second crankshaft.
  • This means is defined by a new form of spacing between the two crankshafts, so as to cause the overflow of the coupling of the variable timing transmission next to the engine flywheel.
  • the control of the variable pitch transmission is provided with a direct drive cylinder for controlling the phase angle between the short stroke crankshaft and the long stroke crankshaft.
  • Means are provided to allow the reduction, see preferably the removal of transfers of engine torque not regulated by the small crankshaft on the shaft line of the large crankshaft.
  • crankcase Other means are also provided in the crankcase by a new arrangement of the two cylinders grouped to form at their top dead center a combustion chamber common to these two cylinders. Also, this new arrangement of the two cylinders grouped in the crankcase allows the decluttering of the two couplings of the two crankshafts, this means allowing the standardization of the center-to-center spacing on the coupling of the large crankshaft.
  • the patent EP 0689642 B1 describes a four-stroke variable displacement ratio engine designed with two crankshafts, a long stroke crankshaft and a short stroke crankshaft. It is known that the shaft line of a crankshaft of an internal combustion engine is an element capable of vibrating naturally in torsion because of its elasticity and the masses of the organs under effort, which are directly or indirectly related to it.
  • the short-stroke crankshaft does not have a force-regulating steering wheel. Consequently, at the output of the variable-timing transmission there is a plurality of unregulated motive torques which generate vibrations caused by the short-stroke crankshaft on the long-stroke crankshaft. As a result, the computation of the resistance of the crankshaft with a large stroke is then inherent to the torques coming from its own cylinders, but also to the torques coming from the cylinders of the small-stroke crankshaft.
  • the present invention relates to the concept of a variable volumetric ratio engine which makes it possible to vary the volume of the combustion chamber as a function of the density and the temperature of the intake air, the speed of rotation and the the engine temperature, which allows a supercharging of the engine, with the support of a single or double supercharging pressure with inter cooling.
  • the present invention describes a novel combination of a four-stroke variable-volume combustion chamber engine.
  • the engine advantageously comprises a kinematic chain where the shafts of the two crankshafts are coupled at the same rotational speed by means of the variable-pitch transmission.
  • the angular displacement stroke between the two crankshafts performed between the start and the end of travel of the variable pitch transmission is arranged by a suitable ratio between the two displacements of the two grouped cylinders and between the volume of the latter and the dead space which makes it possible to modulate the volumetric ratio of the engine by the linear displacement of the piston of the small cylinder relative to the phases of the engine.
  • Engine manufacturers therefore comply with certain design rules by determining, on the one hand, a limit to the amplitude of the intake pressure variations and, on the other hand, by producing an average compression ratio between the pressure of the engine and the engine. atmospheric suction and boost pressure. As the determination of the average compression ratio is a compromise best reconciling the different engine speeds, the atmospheric suction speed is located at too low pressures and temperatures, and the supercharging pressure regime is located at too high pressures and temperatures.
  • the cylinder block part advantageously has a face along which the cylinders are advantageously opened along the face of the head gasket plane, channels and passages being formed in the face of the cylinder block making facing the joint plane of the cylinder head to form at least one separate passage or channel for each cylinder group, a channel or passage of a group extending between a cylinder of the first series and a cylinder of the second series, said channel having a mean and / or minimum width (determined in the joint plane) between 0.25 and 2 times, advantageously between 0.3 and 1 time, preferably between 0.5 and 0.8 times the average diameters of the cylinders connected by the channel or passage considered.
  • the axis of a cylinder of the first series of the group considered forms with a straight line parallel to the axis of rotation of a line crankshaft shaft a first plane
  • said planes define between them an angle between 1 ° ° and 60 °, preferably between 10 ° and 50 °, preferably between 15 ° and 45 °.
  • the axes of the cylinders of a group intersect substantially at one point.
  • the median plane or the median line of a group of cylinders is substantially perpendicular to said plane defined by the two axes of rotation of the two crankshaft shaft lines.
  • the volume of the channel situated between two cylinders of a group is between 1% and 25%, in particular from 2% to 15%, of the total dead volume of the group considered. , said total dead volume being defined by the total free volume of the group with the two pistons in the top dead center position.
  • the motor comprises a camshaft engaged at half speed with the first crankshaft line (4) to ensure the periodic communication of the groups of two cylinders (2,3). with intake and exhaust lines by means of intake and exhaust valves at predetermined times in the four-stroke cycle.
  • the engine comprises an arrangement for the variable pitch transmission, said arrangement being adapted to at least partially receive a device for controlling the difference in phase angle between the first and second crankshaft lines.
  • crankshaft lines are respectively associated with a first drive wheel and a second drive wheel
  • drive means extend between said wheels.
  • variable-pitch transmission when a flywheel is mounted on the axis of the crankshaft with a large stroke, while the variable-pitch transmission is mounted on the axis of the short-stroke crankshaft, the distance separating the axes both crankshafts are sufficient, so that the variable timing transmission is located next to the engine steering wheel.
  • control of the variable timing transmission includes a direct drive pilot cylinder for controlling the difference in phase angle between the short stroke crankshaft and the long stroke crankshaft.
  • the engine comprising a variable pitch transmission comprising a separate assembly of the short crank crankshaft shaft.
  • the variable-pitch transmission has an applied bearing which is centered in a hole in the cylinder block.
  • the variable-pitch transmission comprises a shaft whose one end has external splines, while the shaft is associated with an element or has a portion having a recess with internal grooves adapted to cooperate with the external splines of the shaft to ensure a coupling of the shafts between them, while allowing axial movement between them.
  • the shaft (13) is associated with a bearing journal (20) having internal splines cooperating with the outer splines of the shaft (12).
  • the engine comprises means for reinforcing the axial stiffness between the short-stroke crankshaft (5) and the variable-pitch transmission (10), the shafts (12, 13) are merged into a single shaft so as to allow the transmission shaft (35) comprising the disc (40) and the straight splines (47) to be associated with the short-stroke crankshaft (5).
  • the separation distance between the disk mounting brackets (40) and the bearing (15) is made at the same separation distance between the cylinder block housing (1) of the bearing (15) and the disk mounting bracket ( 40) when the short-stroke crank shaft is inserted into the bearings of the crankcase. It follows from this assembly an axial attachment of the short-stroke crank shaft (5) by the bearing (39) and a radial attachment of the sleeve (36) by the bearings of the small stroke crankshaft (5).
  • the axis of the cylinders of the first series is disposed substantially perpendicular to the joint plane. breech.
  • the pistons of the cylinders of the second series are provided with a corrective boss of the shape of the combustion chamber, said boss having at least one face substantially parallel to the joint plane of the cylinder head.
  • the face substantially parallel to the yoke joint plane is at least 25%, advantageously at least 40%, preferably at least 60% to 90% of the cylinder surface of the second series measured in the plane of the yoke. cylinder head gasket.
  • the piston of the cylinder of the first series has a substantially parallel face to the yoke joint plane, said face having a recessed portion adapted to be open on a channel.
  • the boss and / or the recess are adapted to form in the dead position of the pistons a dead volume having at least one adjacent portion of the channel extending into the cylinder under the head gasket plane without the gasket.
  • cylinder head at a height equal to at least the depth of the channel (32) under the bolt plane.
  • the engine has a cylinder head adapted to receive for each cylinder of the second series a portion of the piston in top dead position and to form at least partially for each cylinder of the second series, in position top dead center of the piston a recess of a portion of the piston exceeding the cylinder head plane or a chamber located in the cylinder housing communicating with the channel.
  • the axes of the cylinders of the first series and the axes of the cylinders of the second series are not arranged perpendicular to the yoke plane.
  • the pistons of the cylinders of the second series are truncated in a corrective manner to the shape of the combustion chamber, said pistons having at least one face substantially parallel to the joint plane of the cylinder head, and the pistons of the cylinders are truncated in a corrective manner to the shape of the combustion chamber, said pistons having at least one face substantially parallel to the joint plane of the cylinder head .
  • the engine comprises a flywheel focused and fixed on the end of the crankshaft of the pistons of the cylinders of the first series in a coupling housing.
  • the variable pitch transmission (10) is focused on the end of the shaft of the small crankshaft (5) next to the engine flywheel (26).
  • the engine comprises in the coupling housing, a transmission with gear train between the crankshaft of the pistons of the second series and the engine flywheel via the variable-pitch transmission.
  • the variable-pitch transmission comprises a shaft or shaft sliding axially relative to the axis of rotation of the crankshaft of the pistons of the cylinders of the second series, while the engine comprises stop means for limiting the stroke of the variable-pitch transmission movement between a start and an end of travel.
  • the engine comprises a control cylinder controlling the axial displacement of the tube or the sliding shaft, said cylinder being associated with stop means for limiting the movement between said start and end of stroke, said control cylinder being advantageously fixed on a support provided on a closing cover of the coupling housing located next to the flywheel.
  • the shafts of the two crankshafts are associated with direct drive gears, the shafts rotating in the opposite direction of rotation and at the same speed.
  • the shafts of the two crankshafts are coupled to each other by a train of two intermediate coupling gears arranged between the two gears mounted on the shafts so that the latter rotate in the opposite direction of rotation and at the same speed.
  • the two intermediate gears located between the gears mounted on the shafts are advantageously arranged and coupled each on either side of a plane passing through the axes of the two crankshafts.
  • the engine comprises a control cylinder for varying the angular position between the two crankshafts (4,5) without passing through the engine flywheel (26) located at the rear of the engine ;
  • variable-pitch transmission comprises three superimposed concentric elements, namely an internal element constituted by a transmission shaft, an external element consisting of a sleeve carrying a gear for coupling the two lines of crankshafts, and an element intermediate between said inner and outer elements and consisting of a sliding tube relative to said inner and outer elements, the sleeve being held in a bearing bearing, by means of a bearing.
  • the second crankshaft shaft has a shaft whose end is joined to one end of the transmission shaft, said ends having corresponding male and female straight splines to allow coupling and self centering of the three elements of the transmission.
  • variable pitch relative to the shaft of the second crankshaft line when attaching the bearing applied in an orifice provided the cylinder block this means, according to one embodiment, allowing the assembly and disassembly of the transmission variable pitch without having to disassemble the second crankshaft shaft line.
  • a bearing carries a fixing ring forming the housing of the outer ring of a bearing whose inner ring is fixed on the sleeve so as to maintain the drive shaft.
  • a spacer extends between the inner ring of the bearing and the inner ring of the bearing, this spacer compensating the space separating between said rings and maintaining the bearing ring axially against a shoulder that the sleeve presents, while a single nut ensures fixing the inner rings of the bearing and the bearing and the spacer on the sleeve.
  • the transmission shaft has on the side of the fixing ring straight splines on which is slipped the sliding tube having on its inner face straight splines so as to slide linearly on the transmission shaft the sleeve has on its face.
  • the sliding tube has an end permanently disengaged from the sleeve, said end being secured to an inner ring of a two row angular contact bearing, the outer ring of the bearing being secured to an attachment piece to the jack.
  • the helical splines are arranged so that the sliding tube moving out of the sleeve decreases the angular advance of the crank of the second crankshaft line relative to the crank of the first crankshaft line.
  • the engine comprises at least one fuel injector in the dead space, the fuel injection is carried out at half speed with the crankshaft with a large stroke.
  • the ignition is controlled and comprises at least one spark plug in the dead space, the ignition being carried out in synchronism at half speed with the first crankshaft line.
  • the engine has a ratio between the displacements of the two grouped cylinders (2, 3) between 1/10 and 9/10, advantageously between 1/5 and 3/5.
  • the engine comprises an oil sump (27) which includes all of the two crankshafts from below the cylinder block.
  • the four-stroke internal combustion engine comprises an oil sump located below the crankshaft of the cylinder pistons of the first series, while the crankshaft of the piston pistons of the second series is enclosed in the cylinder block above a face of the cylinder block and at a level located above the oil sump, said face being inclined towards the oil sump, said inclined face of the cylinder block being advantageously equipped with an access panel to the crankshaft of the pistons of the cylinders of the second series.
  • the engine comprises a variable-pitch transmission control cylinder, said variable-pitch transmission advantageously located at the front of the engine without passing through the steering wheel located at the back of the engine.
  • the four-stroke internal combustion engine comprises two separate casings, namely a coupling casing and a cylinder block, so that the two abovementioned elements are assembled side by side in the axial direction of the casings.
  • crankshafts the engine comprises a flywheel mounted by means of a concentric engagement centered on the shaft of the large crankshaft.
  • the coupling housing is movable relative to the cylinder block so as to angularly position it on the cylinder block by fastening means, in particular provided on the periphery of the contiguous portions of the two aforementioned casings.
  • the four-stroke internal combustion engine comprises a coupling housing and a crankcase forming a single non-divisible element, and an oil sump lying below the two said casings and adapted to be disassembled, so that disassembly of said oil pan also releases the underside of the coupling housing.
  • the invention further relates to a machine or an apparatus or a machine provided with one or more motors according to the invention.
  • the present invention relates to more suitable means for regulating the instantaneous couples between the two crankshafts of the variable volumetric ratio engine.
  • variable-pitch transmission is coupled to the engine flywheel and placed in interposition between the engine flywheel and the crank shaft with a large stroke.
  • Means are provided so that the displacement of the hydraulic cylinder on the control of the variable pitch transmission varies the angular position between the two shafts of the two crankshafts so that it is achieved without the slightest axial effort on the shaft of the small crankshaft .
  • this new engine comprises two lines of crankshafts, one with a crank with a large stroke, the other crank with short stroke.
  • the two crankshafts are coupled to the flywheel of the engine at the same rotational speed by means of a gear train and a variable timing transmission whose coupling gear forming part of the gear train moves angularly relative to to the short-stroke crankshaft, which allows an infinite number of wedges between the two crankshafts without requiring interruption of transmission between them.
  • the coupling of the shaft of the variable-pitch transmission is placed inside the first bearing of the short-stroke crankshaft, so as to promote a greater axial precision and a smaller space requirement. says mating.
  • variable pitch transmission is arranged and fixed in the cylinder block in such a way that the coupling of the variable timing transmission can overflow into the coupling case next to the engine flywheel.
  • the variable timing transmission is designed such that it can be separated from the crankcase independently of the short stroke crankshaft shaft, the long stroke crankshaft shaft and the engine flywheel.
  • a closing cover on the coupling housing said closure cover also serving as a mounting bracket for the driving cylinder of the variable-pitch transmission. Disassembly of the closing cover of the coupling housing making accessible the variable-pitch transmission fixed on the cylinder block. Disassembly of the variable-pitch transmission of the cylinder block is realized as an interchangeable mechanical assembly without the need to disassemble the coupling housing.
  • the two grouped cylinders are arranged in inverted V-shape.
  • the two cylinders grouped are contiguous by their top dead center so as to form in the cylinder block a common combustion chamber to allow the gas to pass from one to the other of these cylinders regardless of the position of the pistons.
  • the engine may also have several groups of two cylinders, each of the cylinders is located above one of the two rows of crankshafts. The crankshaft crankshaft with small stroke operating with the piston rod of the smaller cylinder, the crankshaft crankshaft with large stroke operating with the piston rod of the largest cylinder.
  • the engine comprises at least one fuel injector in the dead space, the fuel injection is carried out at half speed with the crankshaft with a large stroke.
  • the engine comprises at least one spark plug in the dead space
  • the ignition is carried out by known means in synchronism at half speed with the crankshaft with a large stroke.
  • the distribution is ensured at least by a camshaft engaged at half speed with the crankshaft with a large stroke, periodically communicating the group of two cylinders with the intake and exhaust pipes (not shown) by means of the intake and exhaust valves (not shown) at specific times in the four-stroke cycle.
  • the expansion phase is carried out simultaneously on each piston of the two cylinders grouped making the two crankshafts cooperate with the engine force.
  • the two crankshafts are put in direct connection with the external transmission members of the engine, so that the variable-pitch transmission transmits only the engine torque of the crankshaft at short stroke on the engine flywheel without passing over the crank handle (s). the tree of the big crankshaft.
  • variable-pitch transmission between the two crankshafts have the effect of modifying, in the fine compression phase (top dead center of the piston of the largest displacement), an additional space generated in the smallest displacement. additional space being defined with the dead space, so as to modify the volumetric ratio of the engine in the maximum direction at the beginning of travel of the variable-pitch transmission, and in the minimum direction at the end of the travel of the variable-pitch transmission.
  • a hydraulic force amplifier whose slave cylinder acts on the variable-pitch transmission, modifies the additional volume of the small displacement in proportion to the supercharging pressure, to maintain the engine under optimal operating conditions with minimum pollution.
  • a pre-established program on a pre-series engine makes it possible to eliminate the excessive stress of pressures and temperatures.
  • Each engine speed is stored in a ladder progression ladder, so as to encompass all engine capabilities.
  • Each storage point is a combination of four sensor measurements: intake air pressure, intake air temperature, engine speed, and engine temperature.
  • Each combination is recorded simultaneously with the position of the control cylinder of the variable timing transmission.
  • This program allows the automatic piloting of the engine of series identical to that of the engine carried out with the test bench.
  • the fuel specifications must also be identical to reproduce exactly the same operating conditions on the standard engine, thanks to high frequency monitoring of the measurements of the four sensors.
  • an arrangement of the variable pitch transmission is provided to improve the control device of the phase angle between a first and second crankshaft.
  • This means is defined by a new form of spacing between the two crankshafts, so as to cause the overflow of the variable timing transmission next to the engine flywheel.
  • the variable-pitch transmission is equipped with a direct-drive pilot cylinder to control the phase angle between the short-stroke crankshaft and the long-stroke crankshaft.
  • the dimensional ratio between the two displacements of the two grouped cylinders can be at least between 1/10 and 9/10, preferably between 1/5 and 3/5 depending on the degree of maximum supercharging pressure provided. for the engine.
  • the configuration of the variable volumetric ratio engine has the axes of the two grouped cylinders arranged in the form of an inverted V asymmetric with respect to the plane of the cylinder head.
  • the opening angle between axes of the two cylinders grouped can be adapted between 1 and 60 degrees minimum according to the requirements due to the size of the fixed and movable parts of the couplings of the two crankshafts.
  • the arrangement of the axes of the two cylinders grouped in the crankcase of the engine is presented under two different options: the first option of the engine has two cylinders grouped oriented in inverted V-shaped asymmetric but of which only the axis the larger of the two cylinders is fixed perpendicular to the plane of the cylinder head, the piston of the small cylinder is provided with a rectifying boss of the contour of the combustion chamber so as to achieve the top dead center, in the thin phase of compression, the shape and the minimum volume of the combustion chamber, there is also provided a recess on the piston of the large cylinder oriented perpendicularly to the plane of the cylinder head.
  • the hollow and the boss of said pistons are advantageously arranged so as not to close the communication port of the two cylinders grouped when said pistons are positioned at top dead center.
  • the second option of the engine is with the axes of the two asymmetrical inverted V-shaped cylinders not arranged perpendicularly to the plane of the cylinder head.
  • the space between the untrimmed planes of the two pistons located at top dead center and the plane of the cylinder head forms the combustion chamber.
  • the cylinder of the large-stroke crankshaft and the cylinder of the small-stroke crankshaft are joined to each other by their top dead center, so as to create a combustion chamber common to these two cylinders grouped.
  • the combustion chamber being unified with said cylinders by a recess or channel at the joint to the cylinder head plane or beyond the cylinder head plane, so that the intake and combustion gases can communicate continuously between said cylinders and the combustion chamber, regardless of the position of the pistons in the four-stroke cycle.
  • the engine flywheel is focused and attached to the end of the large crankshaft shaft at the rear of the engine; the variable-pitch engine transmission is focused on the end of the shaft, on the side of the engine flywheel.
  • the coupling between the small crankshaft and the flywheel of the engine is carried out integrally with said flywheel via the variable-pitch transmission allowing the said flywheel of the engine to simultaneously regulate the pairs of each of the two crankshafts independently of one another.
  • the engine architecture is realized according to the requirements of the separation distance between the two shafts of the two crankshafts. At a lower separation distance between the two gears focused on their respective crankshaft, the latter are coupled in direct drive at the same rotational speed. At a greater separation distance between the two crankshafts, a kinematic chain, composed of two complementary coupling gears between the two gears geared to their respective crankshaft, is provided to also determine a coupling at the same speed of rotation.
  • the means of a control jack is also valid when the variable-pitch transmission is at the front of the engine, so as to be able to vary the angular setting between the two. crankshafts without passing through the steering wheel located at the rear of the engine.
  • the cylinder block (1) comprises two crankshafts (4,5) arranged in parallel, one crank with a large stroke (4), the other crank with short stroke (5) , the two cylinders (2, 3) respectively provided with pistons (6,8) and respective connecting rods (7,9) are each disposed above the two lines of crankshafts (4 and 5).
  • the small crankshaft crank (5) supported by the bearings (20) operating with the connecting rod (9) of the piston (8) of the smaller cylinder (3), the crankshaft of the large-stroke crankshaft (4) supported by the bearings (21) operating with the connecting rod (7) of the piston (6) of the largest cylinder (2).
  • the axes of the two grouped cylinders (2, 3) are arranged in the cylinder block (1) in the form of an inverted V asymmetrical with respect to the plane of the cylinder head (29). It can be seen that the two aforementioned cylinders are also contiguous to each other by means of a dead space relative to the common combustion chamber (24). The passage of gases between said cylinders (2,3) is effected by an orifice or internal channel or channel formed in the cylinder block (32) of said combustion chamber.
  • the ratio between the displacements of the two cylinders grouped (2,3) in the 4 figures is set at 2/5, which determines a theoretical torque portion of 2/7 for the cylinder of the small cylinder (3) relative to the total displacement of the two cylinders grouped (2,3).
  • the head-to-foot distance between the connecting rods and the piston stroke is 1.68.
  • the stroke / bore ratio of the cylinders is set at 1.21.
  • the sizing of the other components of the two engine options were based on a widely tested 6-cylinder in-line type compression-ignition engine with a maximum speed of 2200 rpm and a horsepower of 400 horsepower. validated on a course of 1,500,000 kilometers.
  • the engine comprises at least one fuel injector (not shown) in the dead space (24).
  • the injection of the fuel is carried out by known means (not shown) engaged at half speed with the crank crankshaft with large stroke (4).
  • the engine comprises at least one spark plug (not shown) in the dead space (24).
  • the ignition is carried out by known means (not shown) in synchronism at half speed with the crankshaft with a large stroke (4).
  • a second camshaft (not shown) engaged at half speed with the long stroke crankshaft (4) may be provided in the part of the cylinder head (not shown) overhanging the smaller one cylinder (3), so as to ensure periodic second opening and closing of the inlet and the exhaust at the same time as the opening and closing of the four-stroke cycle carried out in the largest cylinder (2).
  • the ratio between the displacements of the two grouped cylinders (2, 3) is at least between 1/10 and 9/10, preferably between 1/5 and 3/5, making it possible to adapt the engine to supercharging pressure ratios of 1 to 7.
  • variable-pitch transmission (10) is formed of three superimposed concentric elements: the first element is constituted by the transmission shaft (35) located in the inner part the second element is constituted by the sleeve (36) of the gearing (14) located in the outer portion and the third member is constituted by the sliding tube (17) located in the intermediate portion between the two other aforementioned elements.
  • the sleeve (36) is held in an applied bearing (15) by means of a bearing (39) in a suitable row between the bearing (15) and the sleeve (36).
  • Said bearing (15) is fixed to the cylinder block (1) so that the variable pitch transmission (10) can constitute a separate assembly of the shaft (13) of the short-stroke crankshaft (5).
  • the small-stroke crankshaft (5) and the variable-pitch transmission (10) are made in connection with their respective shaft (12) and (13).
  • the variable-pitch transmission (10) is provided with an applied bearing (15) which is centrally fixed in an orifice in the cylinder block (1).
  • the internal straight grooves of the shaft (12) are located in the trunnion of the cylinder.
  • bearing (20) are matched with the external straight splines of the shaft (13), in order to have sufficient rigidity qualities of the axis of the variable-pitch transmission and a reduced bulk of the coupling between the two shafts ( 12,13); this arrangement allows the dismounting of the variable timing transmission out of the engine block (1) without having to disassemble the short-stroke crankshaft (5).
  • the shaft (35) and the sleeve (36) are advantageously held concentrically and axially relative to each other by means of a bearing (40) integral with the shaft (35).
  • the bearing (40) is provided with an axial and radial thrust bearing (43) for free rotation of the shaft (35) independently of the sleeve (36).
  • the bearing (40) is an integral part of the shaft (35) where the straight splines (12) and (47) are limited.
  • the bearing (40) and the sleeve (36) are located inside the crankcase (1).
  • the bearing (40) is in the form of a disk regularly pierced with orifices for bolting a ring (41) located on the face of the side where the straight splines (47) of the shaft (35) are limited. ).
  • the application of the ring (41) on the bearing (40) is used to form a housing for fixing the outer ring (42) of the bearing (43) axial and radial forces, while the inner ring ( 44) of the bearing (43) is fixed on the sleeve (36) against a spacer (45) in the form of a ring surrounding the sleeve (36), the spacer (45) is intended to catch the separation space between the ring inside (44) of the bearing (43) and the inner ring (37) of the bearing (39), the latter being held axially against a shoulder provided on the sleeve (36) by the fixing of all the aforementioned parts by means of a nut (51) on the sleeve (36).
  • the gear (14) of the sleeve (36) is located outside the crankcase (1) coupled at the same speed of rotation with the long-stroke crankshaft (4) by means of a gear (16) secured to it. last and two intermediate gears (not shown) between the two aforementioned gears (14,16).
  • the drive shaft (35) comprises on the side of the bearing (40) facing the applied bearing (15) straight splines (47) on which the sliding tube (17) engages.
  • This sliding tube (17) has on its inner periphery splines (48) matched to the straight splines (47), so that the sliding tube (17) can slide axially on the transmission shaft (35).
  • the sleeve (36) has on its inner periphery helical splines (49) matched to the outer helical splines (52) of the sliding tube (17) so that the latter can slide helically in the sleeve (36) and allow angular displacement. between said second and third elements at the same time as the right sliding between the first and third elements mentioned above.
  • the sleeve (36) is fixed integrally in rotation with the shaft (17) when the sliding tube (17) is not in axial translation.
  • the length of the sliding tube (17) is pre-established inside the sleeve (36) when the end of said sliding tube (17) is at the stop limit defined by the obstruction of the bearing (40).
  • the other end of the sliding tube (17) is disengaged outside the sleeve (36) through the gear (14) out of the engine block (1) to allow, by appropriate means, the fixing of the ring Inner bearing (50) with two rows of oblique contact.
  • Said inner ring of the bearing (50) is made integral with the rotational movement of the sliding tube (17), while the outer ring of the bearing (50), without rotational movement, is secured to the attachment piece (18). ).
  • a decision memory of the compression rate program acting by a hydraulic control system allows the displacement of the attachment piece (18) and the sliding tube (17) to modify the wedging between the two crankshafts (4 and 5).
  • the start of travel of the variable pitch transmission is arranged so that the sliding tube (17) is at the output stop position provided on the cylinder (not shown) corresponds to the minimum angular advance of the crankshaft crankshaft. short stroke (5) relative to crankshaft crank with large stroke (4).
  • the end of travel of the variable pitch transmission is arranged in such a way that the sliding tube (17) is at the stop position also provided on the jack (no shown) corresponding to the maximum angular advance of the short-stroke crankshaft crank (5) relative to the long-stroke crankshaft crank (4).
  • the distribution is provided at least by a camshaft (not shown) engaged at half speed with the crankshaft large stroke (4).
  • the intake and exhaust valves in the cylinder head (not shown), periodically communicating the group of two cylinders (2, 3) with the intake and exhaust lines (not shown) at specific times in the cylinder. four-stroke cycle.
  • the ratio between the cylinder capacity of the cylinder (3) and the cylinder capacity of the cylinder (2) is at least between 1/10 and 9/10, preferably between 1/5 and 3/5, making it possible to adapt the volumetric ratio of the engine to depending on the rate of the boost pressure.
  • variable-pitch transmission (10) is provided with an applied bearing (15) which attaches to the cylinder block (1), so that the variable-pitch transmission (10) can constitute a separate assembly of the shaft (13). crankshaft crankshaft with short stroke (5).
  • the variable-pitch transmission (10) and the short-stroke crankshaft (5) are each made with their respective shaft (12, 13).
  • the externally splined end of the shaft (12) of the variable pitch transmission (10) is made to match the internal splines in the bearing journal (20) and the shaft (13).
  • the coupling between the two contiguous parts is provided by axial sliding at the time of application of the applied bearing (15) in an orifice provided in the cylinder block (1).
  • the bearing (15) is centered on the shaft (13) of the crankshaft crankshaft with short stroke (5), so as to allow the centering of the shaft (12) in the trunnion (20) and in said shaft ( 13), the latter advantageously acting as a rigid bearing on the shaft (12) during the application of the bearing (15) to the cylinder block (1); this means allowing disassembly of the variable-pitch transmission (10) out of the cylinder block and out of the coupling housing (1) without having to disassemble the short-stroke crankshaft crankshaft (5).
  • the contiguous male end of the shaft (12) of the variable pitch transmission (10) and the female contiguous end formed in the shaft (13) at the small crank crankpin (20) of the crankshaft ( 5) provide the advantage of reducing the size of the coupling of the variable-pitch transmission in the crankcase (1),
  • the engine comprises means for reinforcing the axial rigidity between the short-stroke crankshaft (5) and the variable-pitch transmission (10), the shafts (12 and 13) being fused into a single shaft so as to allow the transmission shaft (35) comprising the disk (40) and the straight splines (47) to be associated with the short-stroke crankshaft (5).
  • the separation distance between the disk mounting brackets (40) and the bearing (15) is made at the same separation distance between the cylinder block housing (1) of the bearing (15) and the disk mounting bracket ( 40) when the short-stroke crank shaft is inserted into the bearings (20) of the cylinder block (1). It follows from this assembly an axial attachment of the short-stroke crank shaft (5) by the bearing (39) and a radial attachment of the sleeve (36) by the bearings of the small stroke crankshaft (5).
  • the coupling housing (31) there are provided two intermediate coupling gears (not shown) between the gears (14) of the short-stroke crankshaft (5) and a second gear ( 16) fixed to the spacer (19) integral with the flywheel of the motor (26) and the crankshaft with a large stroke (4) so as to obtain opposite directions of rotation at the same speed of the two crankshafts (4,5).
  • the variable-pitch transmission (10) comprises a sliding tube (17) on the gear-facing side (14), the outer portion of the sliding tube has on its outer periphery helical splines paired with the helical splines (not shown) of the gear (14).
  • the sliding tube (17) also comprises internal straight splines (not shown) matched to the external splines integral with the shaft (12) (not shown) on which the sliding tube (17) is engaged so that said sliding tube (17) can effect the angular offset between the transmission shaft (12) and the gear (14).
  • the start and end of travel of the variable pitch transmission can be arranged in such a way that the sliding tube (17) can not slide beyond the stop positions which are provided on the control jack (not shown).
  • Said control cylinder being fixed on a support provided on the closing cover (23) of the coupling housing (31) located next to the flywheel (26). Disassembly of the closure cover (23) making it possible to make maintenance or dismantling of the variable-pitch transmission (10) accessible without disassembly of the coupling housing (31).
  • the axis of said control jack is advantageously fixed to the attachment piece (18) of the control of the variable pitch transmission (10).
  • the minimum and maximum volumetric ratios selected for the type of engine to be designed are made according to the dimensions of the various elements of the engine, namely on the one hand, the ratio between the cubic capacity of the two grouped cylinders (2 and 3) and secondly, the ratio formed by the total volume of the two displacements of these cylinders (2, 3) with the volume formed by the dead space (24), these latter ratios are arranged from in such a way that the maximum angular advance of the crankshaft of the short-stroke crankshaft (5) relative to the crankshaft of the long-stroke crankshaft (4), defined by the end-of-travel position of the variable-pitch transmission, correspond, in the end phase of compression (top dead center of the piston 6), the positioning of the piston (8) with the additional space necessary for the dead space (24) to define the said minimum volumetric ratio of the engine with an angle of at least 90 ° between the connecting rod (9) and crankshaft crankshaft short stroke (5).
  • the selected maximum volumetric ratio is made on the same data base as the dimensional values defined for the minimum volumetric ratio, such that the minimum angular advance of the crankshaft of the short-stroke crankshaft (5) relative to the crank of the crankshaft with a large stroke (4), defined by the start position of the variable-pitched transmission, correspond in the fine compression phase (top dead center of the piston (6), the positioning of the piston (8) with the additional space required for the dead space (24) to define the maximum volumetric ratio of the engine with the connecting rod (9) of the small crankshaft crank (5) spaced from its top dead center, so that said connecting rod (9) forms an angle with the crankshaft of the short-stroke crankshaft (5).
  • This operation has the advantage of accelerating the process of changes in the volumetric ratio of the engine at low load.
  • Va additional volume in addition to the volume of the dead space at the beginning of the variable-pitch transmission defined by the minimum angle of the angular advance of the crankshaft of the small-stroke crankshaft.
  • Vr ( ⁇ minimum) air flow volume at the start of the variable-timing transmission stroke, defined by the minimum angular advance angle of the short-stroke crankshaft crank when the large crankshaft crankshaft is at the bottom dead center, in the late phase admission.
  • V ⁇ 1 + V ⁇ 2 ⁇ number of groups of 2 cylinder engine displacement .
  • V ⁇ 1 + V ⁇ 2 - Vr ⁇ ⁇ Num . grp 2 cyl . Engine displacement defined by the timing of the variable timing transmission .
  • V ⁇ 1 + V ⁇ 2 - Vr ⁇ + ve ve + Goes ⁇ P .
  • Vr ( ⁇ minimum) should not be deduced from V2 because too negligible.
  • V ⁇ 1 + V ⁇ 2 - Vr maximum ⁇ + ve ve + Goes ⁇ . maximum P minimum
  • Vr maximum ⁇
  • the selected minimum volumetric ratio can be achieved between two end-of-travel limits of the variable-pitch transmission.
  • the first limit is achieved with a maximum angular advance of the short-stroke crankshaft crank (5) relative to the crankshaft of the large-stroke crankshaft (4) so as to determine the end of compression (top dead center of the piston 6) the positioning of the piston (8) in relation to the additional space required for the dead space (24) to define the said minimum volumetric ratio with an angle of at least 90 ° between the connecting rod and the crank of the small-stroke crankshaft (5)
  • the second limit is achieved with a smaller angular advance of the short-stroke crankshaft crank (5) relative to the crankshaft of the large-stroke crankshaft (4) and this proportionally to the decrease in the ratio between the two displacements of the two cylinders (2, 3) up to the limit of tolerance generated by the working space of the two crankshafts (4, 5) defined by the parallel and close positions of the two grouped cylinders (2, 3) according to the has the minimum volume
  • Vr ( ⁇ maximum) should not be deduced from V2; because the mass admitted in V1 and V2 is dependent on the calibration memorized between the volumetric ratio and the boost pressure.
  • the selected maximum volumetric ratio is made on the basis of the data of the dimensional values defined for the minimum volumetric ratio, such that at the beginning of the stroke of the variable pitch transmission, the minimum angular advance of the crankshaft crankshaft to small stroke (5) relative to the crankshaft of the large-stroke crankshaft (4) determines, at the end of compression (top dead center of the piston 6), the positioning of the piston (8) in relation to the additional space necessary for the dead space (24) to define a maximum volumetric ratio with the connecting rod (9) of the short crankshaft crank (5) spaced from its top dead center, so that said rod (9) forms an angle with the crank of the crankshaft with short stroke (5).
  • We can therefore define the maximum volumetric ratio according to the formula: V ⁇ 1 + V ⁇ 2 - Vr ⁇ . minimum + ve ve + Goes ⁇ . minimum Maximum P
  • Vr ( ⁇ minimum) should not be deduced from V2, because the air mass admitted at V1 and V2 is dependent on the calibration memorized between the volumetric ratio and the atmospheric depression in the pipe. admission.
  • the above formula recorded in a spreadsheet of the computer makes it possible to generate the dimensional values between the various elements of the engine, that is to say, the volumetric ratios between the two displacements of the two grouped cylinders (2,3). and the ratio formed by the total volume of the two displacements of these cylinders (2, 3) with the volume formed by the dead space (24), the calculation is established in such a way that the specifications which have been provided for the maximum volumetric ratios and engine minima may coincide with the corresponding degrees of the minimum and maximum crank angle of the small crankshaft crank relative to the crankshaft of the large stroke crank respectively of the start and end of stroke of the variable pitch transmission.
  • the engine brake can be maintained by considering an increase in engine power in support of a speed limiter on the vehicle.
  • the multiple enclosing walls of the coolant between the two inverted V-shaped cylinders terminate in a single wall at the junction of the high dead points of said cylinders, said wall being taken advantage of to be enlarged into a substantially rectangular channel shape up to the bolt plane.
  • the passage of gases between the two cylinders grouped by the said channel also makes it possible to concretize a combustion chamber common to these said cylinders.
  • the channels (32) are located only in the cylinder block body and partially in the cylinder head gasket or in the thickness of said cylinder head gasket.

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  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Output Control And Ontrol Of Special Type Engine (AREA)
  • Shafts, Cranks, Connecting Bars, And Related Bearings (AREA)
  • Cylinder Crankcases Of Internal Combustion Engines (AREA)

Description

Le but de l'invention consiste en la régularisation de l'effort du couple moteur entre deux vilebrequins d'un moteur à rapport volumétrique variable, ainsi que de l'agencement d'une chambre de combustion par groupes de deux cylindres.The object of the invention consists in regulating the force of the engine torque between two crankshafts of a variable volumetric ratio engine, as well as the arrangement of a combustion chamber in groups of two cylinders.

Domaine technique de l'inventionTechnical field of the invention

La présente invention concerne l'aménagement de la transmission à calage variable d'un moteur à rapport volumétrique variable pour perfectionner le dispositif de commande de l'angle de phase entre un premier et deuxième vilebrequins. Ce moyen est définie par une nouvelle forme d'espacement entre les deux vilebrequins, de manière à engendrer le débordement de l'accouplement de la transmission à calage variable à côté du volant du moteur. La commande de la transmission à calage variable est pourvue d'un vérin de pilotage en prise directe pour contrôler l'angle de phase entre le vilebrequin à petite course et le vilebrequin à grande course. Des moyens sont prévus pour permettre la réduction, voir de préférence la suppression des transferts d'efforts de couple moteur non régularisés par le petit vilebrequin sur la ligne d'arbre du grand vilebrequin. D'autres moyens sont aussi prévus dans le carter cylindre par une nouvelle disposition des deux cylindres groupés permettant de constituer à leur point mort haut une chambre de combustion commune à ces deux cylindres. Egalement, cette nouvelle disposition des deux cylindres groupés dans le carter cylindre autorise le désencombrement des deux attelages des deux vilebrequins, ce moyen permettant la standardisation de l'entraxe tête pied de bielle sur l'attelage du grand vilebrequin.The present invention relates to the arrangement of the variable-pitch transmission of a variable volumetric ratio engine to improve the control device of the phase angle between a first and second crankshaft. This means is defined by a new form of spacing between the two crankshafts, so as to cause the overflow of the coupling of the variable timing transmission next to the engine flywheel. The control of the variable pitch transmission is provided with a direct drive cylinder for controlling the phase angle between the short stroke crankshaft and the long stroke crankshaft. Means are provided to allow the reduction, see preferably the removal of transfers of engine torque not regulated by the small crankshaft on the shaft line of the large crankshaft. Other means are also provided in the crankcase by a new arrangement of the two cylinders grouped to form at their top dead center a combustion chamber common to these two cylinders. Also, this new arrangement of the two cylinders grouped in the crankcase allows the decluttering of the two couplings of the two crankshafts, this means allowing the standardization of the center-to-center spacing on the coupling of the large crankshaft.

Le brevet EP 0689642 B1 décrit un moteur à rapport volumétrique variable, à quatre temps, conçu avec deux vilebrequins, un vilebrequin à grande course et un vilebrequin à petite course. Il est connu que la ligne d'arbre d'un vilebrequin d'un moteur à combustion interne constitue un élément susceptible de vibrer naturellement en torsion du fait de son élasticité ainsi que les masses des organes sous efforts, qui lui sont liées directement ou indirectement. Dans la description du brevet EP 0689642 B1 précité, le vilebrequin à petite course ne comporte pas de volant régulateur d'efforts. Par conséquent, il se produit à la sortie de la transmission à calage variable un cumul de couples moteurs non régularisés qui génèrent des vibrations provoquées par le vilebrequin à petite course sur le vilebrequin à grande course. De ce fait, le calcul de résistance du vilebrequin à grande course est alors inhérent aux couples issus de ses propres cylindres, mais également aux couples issus des cylindres du vilebrequin à petite course.The patent EP 0689642 B1 describes a four-stroke variable displacement ratio engine designed with two crankshafts, a long stroke crankshaft and a short stroke crankshaft. It is known that the shaft line of a crankshaft of an internal combustion engine is an element capable of vibrating naturally in torsion because of its elasticity and the masses of the organs under effort, which are directly or indirectly related to it. In the patent description EP 0689642 B1 mentioned above, the short-stroke crankshaft does not have a force-regulating steering wheel. Consequently, at the output of the variable-timing transmission there is a plurality of unregulated motive torques which generate vibrations caused by the short-stroke crankshaft on the long-stroke crankshaft. As a result, the computation of the resistance of the crankshaft with a large stroke is then inherent to the torques coming from its own cylinders, but also to the torques coming from the cylinders of the small-stroke crankshaft.

Dans le brevet EP 0689642 B1 le rapprochement en parallèle des deux cylindres groupés a pour conséquence de limiter l'espace latéral nécessaire à la mobilité des deux vilebrequins; dans cette approche, l'architecture du moteur nécessite un éloignement vertical des deux vilebrequins par le moyen de bielles courtes (bielles à petit entraxe) sur le vilebrequin à petite course et de bielles longues (bielles à grand entraxe) sur le vilebrequin à grande de course, ce qui nécessite une plus grande hauteur du carter cylindre. Il est également connu que pour le même angle de manivelle entre le point mort haut et le point mort bas, le déplacement linéaire d'un piston axé sur une bielle courte est d'autant plus rapide aux environs du point mort haut qu'aux environs du point mort bas. Logiquement, on peut discerner qu'une bielle longue sur le vilebrequin à grande course, présente moins d'obliquité dans son mouvement tournant. Il s'ensuit qu'au premier quart de tour de la phase de détente des gaz, la course linéaire du piston du vilebrequin à grande course se trouve diminuée par rapport à son mouvement tournant.In the patent EP 0689642 B1 the parallel approximation of the two grouped cylinders has the effect of limiting the lateral space required for the mobility of the two crankshafts; in this approach, the architecture of the engine requires a vertical distance of the two crankshafts by means of short rods (rods with small spacing) on the small stroke crankshaft and long rods (big-axis rods) on the crankshaft with large diameter. stroke, which requires a larger cylinder block height. It is also known that for the same crank angle between the top dead center and bottom dead center, the linear displacement of a piston focused on a short rod is all the faster around the top dead center than in the vicinity from the bottom dead center. Logically, we can discern that a long rod on the crankshaft with a large stroke, has less obliquity in its rotating movement. It follows that in the first quarter turn of the gas expansion phase, the linear stroke of the crankshaft piston with large stroke is decreased relative to its rotating movement.

La présente invention concerne le concept d'un moteur à rapport volumétrique variable qui permet de faire varier le volume de la chambre de combustion en fonction de la densité et de la température de l'air d'admission, de la vitesse de rotation et de la température du moteur, ce qui permet une hyper suralimentation du moteur, à l'appui d'une simple ou double pression de suralimentation avec inter refroidissement.The present invention relates to the concept of a variable volumetric ratio engine which makes it possible to vary the volume of the combustion chamber as a function of the density and the temperature of the intake air, the speed of rotation and the the engine temperature, which allows a supercharging of the engine, with the support of a single or double supercharging pressure with inter cooling.

La présente invention décrit une combinaison nouvelle d'un moteur à chambre de combustion à volume variable à quatre temps. Le moteur comprend avantageusement une chaîne cinématique où les arbres des deux vilebrequins sont accouplés à même vitesse de rotation au moyen de la transmission à calage variable. La course de décalage angulaire entre les deux vilebrequins réalisée entre le début et la fin de course de la transmission à calage variable est agencée par un rapport approprié entre les deux cylindrées des deux cylindres groupés et entre le volume de ces derniers et l'espace mort, ce qui permet de moduler le rapport volumétrique du moteur par le déplacement linéaire du piston du petit cylindre par rapport aux phases du moteur.The present invention describes a novel combination of a four-stroke variable-volume combustion chamber engine. The engine advantageously comprises a kinematic chain where the shafts of the two crankshafts are coupled at the same rotational speed by means of the variable-pitch transmission. The angular displacement stroke between the two crankshafts performed between the start and the end of travel of the variable pitch transmission is arranged by a suitable ratio between the two displacements of the two grouped cylinders and between the volume of the latter and the dead space which makes it possible to modulate the volumetric ratio of the engine by the linear displacement of the piston of the small cylinder relative to the phases of the engine.

Par définition, le principe de la suralimentation des moteurs à pistons est d'augmenter les masses d'air sans augmenter la cylindrée. Il en résulte pour les moteurs à taux de compression fixe une augmentation de la pression de combustion et une plus grande puissance volumétrique (puissance par litre de cylindrée). Cependant, quand la pression de suralimentation est augmentée, les contraintes d'efforts mécaniques et thermiques s'accroissent sur les organes du moteur. Cet inconvénient majeur provient du fait que le rapport volumétrique, engendré par la chambre de combustion et la course du piston, est non modifiable, ne pouvant s'adapter aux variations de pressions et températures de l'air d'admission et des vitesses et températures du moteur.By definition, the principle of supercharging piston engines is to increase the air masses without increasing the displacement. This results in engines with fixed compression ratio an increase in combustion pressure and a higher volumetric power (power per liter of displacement). However, when the supercharging pressure is increased, the stresses of mechanical and thermal forces increase on the engine components. This major drawback stems from the fact that the volumetric ratio, generated by the combustion chamber and the piston stroke, is non-modifiable, unable to adapt to variations in intake air pressures and temperatures and speeds and temperatures. of the motor.

Dès lors, les motoristes respectent certaines règles de conception en déterminant, d'une part, une limite à l'amplitude des variations de pressions à l'admission, et d'autre part, en réalisant un rapport de compression moyen entre la pression d'aspiration atmosphérique et la pression de suralimentation. Comme la détermination du rapport de compression moyen est un compromis conciliant au mieux les différents régimes du moteur, le régime d'aspiration atmosphérique est situé à de trop basses pressions et températures, et le régime de pressions de suralimentation est situé à de trop hautes pressions et températures.Engine manufacturers therefore comply with certain design rules by determining, on the one hand, a limit to the amplitude of the intake pressure variations and, on the other hand, by producing an average compression ratio between the pressure of the engine and the engine. atmospheric suction and boost pressure. As the determination of the average compression ratio is a compromise best reconciling the different engine speeds, the atmospheric suction speed is located at too low pressures and temperatures, and the supercharging pressure regime is located at too high pressures and temperatures.

L'invention a pour objet un moteur à combustion interne à quatre temps comprenant au moins une phase d'aspiration, une phase de compression, une phase de détente et une phase d'échappement, ledit moteur fonctionnant par auto-inflammation ou par allumage commandé comprenant:

  • une pièce carter cylindre présentant une première série de cylindres (2) présentant chacun un axe et un diamètre et une deuxième série de cylindres (3) présentant chacun un axe et un diamètre, les cylindres (2) de la première série présentant une cylindrée et un diamètre plus grands que la cylindrée et le diamètre des cylindres (3) de la deuxième série,
  • des pistons (6,8), chaque piston étant adapté pour être animé d'un mouvement alternatif dans un cylindre et étant associé à une bielle,
  • deux lignes d'arbres vilebrequins présentant des axes de rotation parallèles entre eux, une première ligne (4) présentant une manivelle avec une grande course, tandis que la deuxième ligne (5) présente une manivelle avec une petite course inférieure à la grande course de la manivelle de la première ligne d'arbre vilebrequin, lesdits arbres vilebrequins (4,5) étant adaptés pour être accouplés à même vitesse de rotation au moyen d'un train d'engrenages (14,16) et d'une transmission à calage variable (10);
dans lequel chaque piston étant associé à une bielle (7,9) est opéré avec une manivelle d'un vilebrequin, la manivelle de petite course de la deuxième ligne d'arbre vilebrequin (5) opérant la bielle (9) du piston (8) se déplaçant dans le petit cylindre (3), tandis que la manivelle de grande course de la première ligne d'arbre vilebrequin (4) opère la bielle (7) du piston (6) se déplaçant dans le grand cylindre (2),
dans lequel la première série de cylindres (2) est disposée au-dessus de la première ligne d'arbre vilebrequin (4), tandis que la deuxième série de cylindres (3) est disposé au-dessus de la deuxième ligne d'arbre vilebrequin (5), et
dans lequel chaque cylindre (2) de la première série communique avec au moins un cylindre (3) de la deuxième série via un espace mort de manière à former un groupe de deux cylindres (2,3) communiquant entre eux pour permettre aux gaz de passer d'un cylindre à l'autre indépendamment de la position des pistons (6,8) se déplaçant dans lesdits cylindres (2,3).The invention relates to a four-stroke internal combustion engine comprising at least one suction phase, a compression phase, an expansion phase and an exhaust phase, said engine operating by auto-ignition or controlled ignition. comprising:
  • a crankcase part having a first series of cylinders (2) each having an axis and a diameter and a second series of cylinders (3) each having an axis and a diameter, the cylinders (2) of the first series having a displacement and a diameter greater than the cylinder capacity and the diameter of the cylinders (3) of the second series,
  • pistons (6,8), each piston being adapted to be reciprocated in a cylinder and associated with a connecting rod,
  • two lines of crankshafts having axes of rotation parallel to each other, a first line (4) having a crank with a large stroke, while the second line (5) has a crank with a small stroke smaller than the large race of the crank of the first crankshaft line, said crank shafts (4,5) being adapted to be coupled at the same rotational speed by means of a gear train (14,16) and a stall transmission variable (10);
wherein each piston being associated with a connecting rod (7,9) is operated with a crank of a crankshaft, the crank of small stroke of the second crankshaft shaft line (5) operating the connecting rod (9) of the piston (8). ) moving in the small cylinder (3), while the long-stroke crank of the first crankshaft line (4) operates the connecting rod (7) of the piston (6) moving in the large cylinder (2),
wherein the first series of cylinders (2) is disposed above the first crankshaft line (4), while the second series of cylinders (3) is disposed above the second crankshaft line (5), and
in which each cylinder (2) of the first series communicates with at least one cylinder (3) of the second series via a dead space so as to form a group of two cylinders (2,3) communicating with each other to allow the gases to pass from one cylinder to the other regardless of the position of the pistons (6,8) moving in said cylinders (2,3).

Dans le moteur selon l'invention, la pièce carter cylindre présente avantageusement une face le long de laquelle les cylindres sont ouverts avantageusement le long de la face du plan de joint de culasse, des canaux et passages étant formés dans la face du carter cylindre faisant face au plan de joint de la culasse pour former au moins un passage ou canal distinct pour chaque groupe de cylindre, un canal ou passage d'un groupe s'étendant entre un cylindre de la première série et un cylindre de la deuxième série, ledit canal présentant une largeur moyenne et/ou minimale (déterminée dans le plan de joint de culasse) comprise entre 0,25 et 2 fois, avantageusement entre 0,3 et 1 fois, de préférence entre 0,5 et 0,8 fois la moyenne des diamètres des cylindres reliés par le canal ou passage considéré.In the engine according to the invention, the cylinder block part advantageously has a face along which the cylinders are advantageously opened along the face of the head gasket plane, channels and passages being formed in the face of the cylinder block making facing the joint plane of the cylinder head to form at least one separate passage or channel for each cylinder group, a channel or passage of a group extending between a cylinder of the first series and a cylinder of the second series, said channel having a mean and / or minimum width (determined in the joint plane) between 0.25 and 2 times, advantageously between 0.3 and 1 time, preferably between 0.5 and 0.8 times the average diameters of the cylinders connected by the channel or passage considered.

Avantageusement, pour un moteur dans lequel pour chaque groupe de cylindres reliés entre eux par un canal ou passage, l'axe d'un cylindre de la première série du groupe considéré forme avec une droite parallèle à l'axe de rotation d'une ligne d'arbre vilebrequin un premier plan, tandis que l'axe du cylindre de la deuxième série du groupe considéré forme avec une droite parallèle à l'axe de rotation d'une ligne d'arbre vilebrequin un deuxième plan, lesdits plans définissent entre eux un angle compris entre 1° ° et 60°, avantageusement entre 10° et 50°, de préférence entre 15° et 45°.Advantageously, for an engine in which for each group of cylinders interconnected by a channel or passage, the axis of a cylinder of the first series of the group considered forms with a straight line parallel to the axis of rotation of a line crankshaft shaft a first plane, while the axis of the cylinder of the second series of the group considered forms with a straight line parallel to the axis of rotation of a crankshaft line a second plane, said planes define between them an angle between 1 ° ° and 60 °, preferably between 10 ° and 50 °, preferably between 15 ° and 45 °.

De préférence, les axes des cylindres d'un groupe se coupent sensiblement en un point.Preferably, the axes of the cylinders of a group intersect substantially at one point.

Selon une forme de réalisation dans lequel un plan est défini par les deux axes de rotation des deux lignes d'arbre vilebrequin, et dans lequel un plan médian ou une droite médiane défini entre lesdits premier et deuxième plans ou entre lesdits axes de rotation, le plan médian ou la droite médiane d'un groupe de cylindres est sensiblement perpendiculaire audit plan défini par les deux axes de rotation des deux lignes d'arbre vilebrequin.According to an embodiment in which a plane is defined by the two axes of rotation of the two crankshaft shaft lines, and in which a median plane or a median line defined between said first and second planes or between said axes of rotation, the median plane or the median line of a group of cylinders is substantially perpendicular to said plane defined by the two axes of rotation of the two crankshaft shaft lines.

Selon un détail avantageux d'un moteur suivant l'invention, le volume du canal situé entre deux cylindres d'un groupe est compris entre 1% et 25%, en particulier de 2% à 15%, du volume mort total du groupe considéré, ledit volume mort total étant défini par le volume libre total du groupe avec les deux pistons en position point mort haut.According to an advantageous detail of an engine according to the invention, the volume of the channel situated between two cylinders of a group is between 1% and 25%, in particular from 2% to 15%, of the total dead volume of the group considered. , said total dead volume being defined by the total free volume of the group with the two pistons in the top dead center position.

Selon un autre détail d'une forme de réalisation, le moteur comprend un arbre à cames en prise à demi-vitesse avec la première ligne d'arbre vilebrequin (4) pour assurer la communication périodique des groupes de deux cylindres (2,3) avec des conduites d'admission et d'échappement au moyen de soupapes d'admission et d'échappement à des moments prédéterminés du cycle à quatre temps.According to another detail of an embodiment, the motor comprises a camshaft engaged at half speed with the first crankshaft line (4) to ensure the periodic communication of the groups of two cylinders (2,3). with intake and exhaust lines by means of intake and exhaust valves at predetermined times in the four-stroke cycle.

Dans une forme de réalisation avantageuse, le moteur comporte un aménagement pour la transmission à calage variable, ledit aménagement étant adapté pour recevoir au moins partiellement un dispositif de commande de la différence d'angle de phase entre les première et deuxième lignes d'arbre vilebrequin.In an advantageous embodiment, the engine comprises an arrangement for the variable pitch transmission, said arrangement being adapted to at least partially receive a device for controlling the difference in phase angle between the first and second crankshaft lines. .

De préférence, lorsque la première et la deuxième ligne d'arbre vilebrequin sont associées respectivement à une première roue d'entraînement et à une deuxième roue d'entraînement, un moyen d'entraînement s'étend entre lesdites roues.Preferably, when the first and second crankshaft lines are respectively associated with a first drive wheel and a second drive wheel, drive means extend between said wheels.

En particulier, lorsqu' un volant moteur est monté sur l'axe de l'arbre vilebrequin à grande course, tandis que la transmission à calage variable est monté sur l'axe de l'arbre vilebrequin à petite course, la distance séparant les axes des deux vilebrequins est suffisante, de manière à ce que la transmission à calage variable se situe à côté du volant du moteur.In particular, when a flywheel is mounted on the axis of the crankshaft with a large stroke, while the variable-pitch transmission is mounted on the axis of the short-stroke crankshaft, the distance separating the axes both crankshafts are sufficient, so that the variable timing transmission is located next to the engine steering wheel.

Par exemple, la commande de la transmission à calage variable comprend un vérin de pilotage en prise directe, pour contrôler la différence d'angle de phase entre l'arbre vilebrequin à petite course et l'arbre vilebrequin à grande course.For example, the control of the variable timing transmission includes a direct drive pilot cylinder for controlling the difference in phase angle between the short stroke crankshaft and the long stroke crankshaft.

Selon une forme de réalisation possible, le moteur comprenant une transmission à calage variable comprenant un ensemble séparé de l'arbre du vilebrequin à manivelle à petite course. La transmission à calage variable est dotée d'un palier applique qui se fixe par centrage dans un orifice prévu dans le carter cylindre. La transmission à calage variable comprend un arbre dont une extrémité présente des cannelures externes, tandis que l'arbre est associé à un élément ou présente une portion présentant un évidement avec des cannelures internes adaptées pour coopérer avec les cannelures externes de l'arbre pour assurer un accouplement des arbres entre eux, tout en permettant un déplacement axial entre eux.According to one possible embodiment, the engine comprising a variable pitch transmission comprising a separate assembly of the short crank crankshaft shaft. The variable-pitch transmission has an applied bearing which is centered in a hole in the cylinder block. The variable-pitch transmission comprises a shaft whose one end has external splines, while the shaft is associated with an element or has a portion having a recess with internal grooves adapted to cooperate with the external splines of the shaft to ensure a coupling of the shafts between them, while allowing axial movement between them.

De préférence, l'arbre (13) est associé à un tourillon de palier (20) présentant des cannelures internes coopérant avec les cannelures externes de l'arbre (12).Preferably, the shaft (13) is associated with a bearing journal (20) having internal splines cooperating with the outer splines of the shaft (12).

Selon une autre forme de réalisation possible, le moteur comprend des moyens pour renforcer la rigidité axiale entre le vilebrequin à petite course (5) et la transmission à calage variable (10), les arbres (12,13) sont fusionnés en un seul arbre de manière à permettre que l'arbre de transmission (35) comprenant le disque (40) et les cannelures droites (47) s'associe au vilebrequin à petite course (5). La distance de séparation entre les supports de fixation du disque (40) et le palier (15) est réalisée à la même distance de séparation entre la fixation du carter cylindre (1) du palier (15) et le support de fixation du disque (40) lorsque l'arbre du vilebrequin à petite course est inséré dans les paliers du carter cylindre. Il découle de cet assemblage une fixation axiale de l'arbre du vilebrequin à petite course (5) par le roulement (39) et une fixation radiale du manchon (36) par les paliers du vilebrequin à petite course (5).According to another possible embodiment, the engine comprises means for reinforcing the axial stiffness between the short-stroke crankshaft (5) and the variable-pitch transmission (10), the shafts (12, 13) are merged into a single shaft so as to allow the transmission shaft (35) comprising the disc (40) and the straight splines (47) to be associated with the short-stroke crankshaft (5). The separation distance between the disk mounting brackets (40) and the bearing (15) is made at the same separation distance between the cylinder block housing (1) of the bearing (15) and the disk mounting bracket ( 40) when the short-stroke crank shaft is inserted into the bearings of the crankcase. It follows from this assembly an axial attachment of the short-stroke crank shaft (5) by the bearing (39) and a radial attachment of the sleeve (36) by the bearings of the small stroke crankshaft (5).

Selon une caractéristique d'une forme de réalisation, dans lequel le joint de culasse s'étend sensiblement dans un plan, par rapport au plan du joint de culasse, l'axe des cylindres de la première série est disposé sensiblement perpendiculairement au plan de joint de culasse.According to a characteristic of an embodiment, in which the cylinder head gasket extends substantially in a plane, with respect to the plane of the cylinder head gasket, the axis of the cylinders of the first series is disposed substantially perpendicular to the joint plane. breech.

De préférence, les pistons des cylindres de la deuxième série sont pourvus d'un bossage rectificatif de la forme de la chambre de combustion, ledit bossage présentant au moins une face sensiblement parallèle au plan de joint de culasse.Preferably, the pistons of the cylinders of the second series are provided with a corrective boss of the shape of the combustion chamber, said boss having at least one face substantially parallel to the joint plane of the cylinder head.

En particulier, la face sensiblement parallèle au plan de joint de culasse est égale à au moins 25%, avantageusement au moins 40%, de préférence au moins 60% à 90% de la surface du cylindre de la deuxième série mesurée dans le plan de joint de culasse.In particular, the face substantially parallel to the yoke joint plane is at least 25%, advantageously at least 40%, preferably at least 60% to 90% of the cylinder surface of the second series measured in the plane of the yoke. cylinder head gasket.

Selon une autre particularité, le piston du cylindre de la première série présente une face sensiblement parallèle au plan de joint de culasse, ladite face présentant une portion en creux adaptée pour être ouverte sur un canal.According to another feature, the piston of the cylinder of the first series has a substantially parallel face to the yoke joint plane, said face having a recessed portion adapted to be open on a channel.

De manière plus spécifique, le bossage et/ou le creux sont adaptés pour former en position mort haut du pistons un volume mort présentant au moins une portion adjacente du canal s'étendant dans le cylindre sous le plan de joint de culasse sans le joint de culasse sur une hauteur égale à au moins la profondeur du canal (32) sous le plan de culasse.More specifically, the boss and / or the recess are adapted to form in the dead position of the pistons a dead volume having at least one adjacent portion of the channel extending into the cylinder under the head gasket plane without the gasket. cylinder head at a height equal to at least the depth of the channel (32) under the bolt plane.

Selon un détail d'une autre forme de réalisation, le moteur présente une culasse adaptée pour recevoir pour chaque cylindre de la deuxième série une partie du piston en position point mort haut et pour former au moins partiellement pour chaque cylindre de la deuxième série, en position point mort haut du piston un évidement d'une partie du piston dépassant le plan de culasse ou une chambre située dans le carter cylindre communiquant avec le canal.According to a detail of another embodiment, the engine has a cylinder head adapted to receive for each cylinder of the second series a portion of the piston in top dead position and to form at least partially for each cylinder of the second series, in position top dead center of the piston a recess of a portion of the piston exceeding the cylinder head plane or a chamber located in the cylinder housing communicating with the channel.

Selon une particularité d'une forme de réalisation particulière, les axes des cylindres de la première série et les axes des cylindres de la deuxième série ne sont pas disposés perpendiculairement au plan de culasse.According to a feature of a particular embodiment, the axes of the cylinders of the first series and the axes of the cylinders of the second series are not arranged perpendicular to the yoke plane.

De façon avantageuse, les pistons des cylindres de la deuxième série sont tronqués de manière rectificative de la forme de la chambre de combustion, lesdits pistons présentant au moins une face sensiblement parallèle au plan de joint de culasse, ainsi que les pistons des cylindres sont tronqués de manière rectificative de la forme de la chambre de combustion, lesdits pistons présentant au moins une face sensiblement parallèle au plan de joint de culasse.Advantageously, the pistons of the cylinders of the second series are truncated in a corrective manner to the shape of the combustion chamber, said pistons having at least one face substantially parallel to the joint plane of the cylinder head, and the pistons of the cylinders are truncated in a corrective manner to the shape of the combustion chamber, said pistons having at least one face substantially parallel to the joint plane of the cylinder head .

Selon une caractéristique d'une autre forme de réalisation possible, le moteur comprend un volant moteur axé et fixé sur l'extrémité de l'arbre vilebrequin des pistons des cylindres de la première série dans un carter d'accouplement.
De préférence, la transmission à calage variable (10) est axée sur l'extrémité de l'arbre du petit vilebrequin (5) à coté du volant du moteur (26).
En particulier, le moteur comporte dans le carter d'accouplement, une transmission avec train d'engrenages entre l'arbre vilebrequin des pistons de la deuxième série et le volant du moteur via la transmission à calage variable.According to a characteristic of another possible embodiment, the engine comprises a flywheel focused and fixed on the end of the crankshaft of the pistons of the cylinders of the first series in a coupling housing.
Preferably, the variable pitch transmission (10) is focused on the end of the shaft of the small crankshaft (5) next to the engine flywheel (26).
In particular, the engine comprises in the coupling housing, a transmission with gear train between the crankshaft of the pistons of the second series and the engine flywheel via the variable-pitch transmission.

Selon toujours une autre caractéristique d'un moteur suivant l'invention, la transmission à calage variable comporte un tube ou arbre coulissant axialement par rapport à l'axe de rotation de l'arbre vilebrequin des pistons des cylindres de la deuxième série, tandis que le moteur comporte des moyens de butées pour limiter la course du mouvement de la transmission à calage variable entre un début et une fin de course.
En particulier, le moteur comprend un vérin de commande commandant le déplacement axial du tube ou de l'arbre coulissant, ledit vérin étant associé à des moyens de butées pour limiter le déplacement entre ledit début et fin de course, ledit vérin de commande étant avantageusement fixé sur un support prévu sur un couvercle de fermeture du carter d'accouplement situé à côté du volant moteur.According to another characteristic of an engine according to the invention, the variable-pitch transmission comprises a shaft or shaft sliding axially relative to the axis of rotation of the crankshaft of the pistons of the cylinders of the second series, while the engine comprises stop means for limiting the stroke of the variable-pitch transmission movement between a start and an end of travel.
In particular, the engine comprises a control cylinder controlling the axial displacement of the tube or the sliding shaft, said cylinder being associated with stop means for limiting the movement between said start and end of stroke, said control cylinder being advantageously fixed on a support provided on a closing cover of the coupling housing located next to the flywheel.

Toujours selon un détail avantageux d'une forme de réalisation possible, les arbres des deux vilebrequins sont associés à des engrenages en prise directe, les arbres tournant en sens de rotation inverse et à même vitesse.Still according to an advantageous detail of a possible embodiment, the shafts of the two crankshafts are associated with direct drive gears, the shafts rotating in the opposite direction of rotation and at the same speed.

De façon avantageuse; les arbres des deux vilebrequins sont accouplés l'un à l'autre par un train de deux engrenages d'accouplement intermédiaires disposé entre les deux engrenages montés sur les arbres afin que ces derniers tournent en sens de rotation inverse et à même vitesse.Advantageously; the shafts of the two crankshafts are coupled to each other by a train of two intermediate coupling gears arranged between the two gears mounted on the shafts so that the latter rotate in the opposite direction of rotation and at the same speed.

De préférence, les deux engrenages intermédiaires situés entre les engrenages montés sur les arbres sont avantageusement disposés et accouplés chacun de part et d'autre d'un plan passant par les axes des deux arbres vilebrequins.Preferably, the two intermediate gears located between the gears mounted on the shafts are advantageously arranged and coupled each on either side of a plane passing through the axes of the two crankshafts.

Dans une forme de réalisation possible, le moteur comprend un vérin de commande pour faire varier la position angulaire entre les deux arbres vilebrequins (4,5) sans passer par l'intermédiaire du volant du moteur (26) situé à l'arrière du moteur;In a possible embodiment, the engine comprises a control cylinder for varying the angular position between the two crankshafts (4,5) without passing through the engine flywheel (26) located at the rear of the engine ;

Selon une forme de réalisation préférée, la transmission à calage variable comporte un mécanisme de commande pour faire varier angulairement le calage de la manivelle de la seconde ligne d'arbre vilebrequin par rapport à la manivelle de la première ligne d'arbre vilebrequin, au moyen d'un amplificateur de force hydraulique comportant un vérin asservi agissant sur la transmission à calage variable, ladite transmission permettant de modifier en phase fin de compression du piston du grand cylindre le rapport volumétrique du moteur entre un rapport volumétrique minimal et un rapport volumétrique maximal, lesdits rapports volumétriques minimal et maximal étant fonction:

  1. a) du rapport entre la cylindrée du grand cylindre et la cylindrée du petit cylindre, et
  2. b) du rapport entre, d'une part, le volume total du petit cylindre et du grand cylindre et, d'autre part, le volume de l'espace mort et d'un volume additionnel créé dans le petit cylindre en phase fin de compression du piston du grand cylindre , la transmission à calage variable réglant l'avance angulaire de la manivelle de la seconde ligne d'arbre vilebrequin par rapport à la manivelle de la première ligne d'arbre vilebrequin pour obtenir lesdits rapports volumétriques, ladite avance angulaire variant entre une avance angulaire maximale telle qu'au moins un angle de 90° soit formé entre la bielle du piston du petit cylindre et la manivelle de la seconde ligne d'arbre vilebrequin en phase fin de compression du piston du grand cylindre pour définir le rapport volumétrique minimal, et une avance angulaire minimale telle que l'angle de l'avance angulaire correspond en phase fin de compression du piston du grand cylindre au positionnement du piston dans le petit cylindre pour créer le volume additionnel requis pour obtenir le rapport volumétrique maximal, la manivelle de la seconde ligne d'arbre vilebrequin formant un angle avec la bielle du piston du petit cylindre.
According to a preferred embodiment, the variable pitch transmission comprises a control mechanism for angularly varying the crank timing of the second crankshaft line relative to the crank of the first crankshaft line, by means of a hydraulic force amplifier comprising a slave cylinder acting on the variable-pitch transmission, said transmission making it possible to modify the volumetric ratio of the engine between a minimum volumetric ratio and a maximum volumetric ratio, in the fine phase of compression of the piston of the large cylinder; said minimum and maximum volumetric ratios being a function of:
  1. a) the ratio between the cylinder capacity of the large cylinder and the cylinder capacity of the small cylinder, and
  2. (b) the ratio between the total volume of the small cylinder and the large cylinder and the volume of the dead space and an additional volume created in the small, thin-phase cylinder of the compression of the piston of the large cylinder, the variable-pitch transmission controlling the angular advance of the crank of the second crankshaft line with respect to the crank of the first crankshaft line to obtain said volumetric ratios, said angular advance varying between a maximum angular advance such that at least a 90 ° angle is formed between the piston rod of the small cylinder and the cranking of the second crankshaft shaft line in the fine phase of compression of the piston of the large cylinder to define the minimum volumetric ratio, and a minimum angular advance such that the angle of the angular advance corresponds to the fine phase of compression of the piston of the large cylinder positioning the piston in the small cylinder to create the additional volume required to obtain the maximum volumetric ratio, the crank of the second crankshaft line forming an angle with the piston rod of the small cylinder.

Selon une particularité d'un moteur pour lequel la manivelle du premier arbre vilebrequin passe par un point mort haut et par un point mort bas lors de sa rotation, les deux lignes d'arbre à vilebrequin sont agencées pour définir un espace de travail minimum des deux lignes d'arbre à vilebrequin de telle sorte que soit obtenu un rapport des cylindrées de deux cylindres groupés minimal. La transmission à calage variable présente une course de déplacement s'étendant entre un début de course et une fin de course , le rapport volumétrique minimal de deux cylindres groupés étant obtenu en fin de course de la transmission à calage variable, ce rapport volumétrique étant calculé par la formule suivante: V ⁢ 1 + V ⁢ 2 - Vr α . ⁢ maximum + ve ve + Va α . ⁢ maximum = P minimum

Figure imgb0001

dans laquelle

  • V1: cylindrée du grand cylindre des deux cylindres groupés.
  • V2 : cylindrée du petit cylindre des deux cylindres groupés.
  • Ve: volume de l'espace mort des deux cylindres groupés permettant le transfert de gaz entre les cylindres sans laminage excessif.
  • (αmaximum): avance angulaire de la manivelle de la seconde ligne d'arbre vilebrequin, en fin de course de la transmission à calage variable.
  • Vr (αmaximum): volume de refoulement d'air en fin de course de la transmission à calage variable, défini par l'avance angulaire de la manivelle de la seconde ligne d'arbre vilebrequin lorsque la manivelle de la ligne d'arbre vilebrequin se situe au point mort bas en phase fin d'admission.
  • Va (αmaximum): volume additionnel s'ajoutant au volume de l'espace mort (24) en fin de course de la transmission à calage variable, défini par l'avance angulaire de la manivelle de la seconde ligne d'arbre vilebrequin lorsque la manivelle de la première ligne d'arbre vilebrequin se situe au point mort haut, en phase fin de compression.
According to a feature of an engine for which the crank of the first crankshaft passes through a top dead center and a bottom dead point during its rotation, the two crankshaft lines are arranged to define a minimum working space of the crankshafts. two crankshaft shaft lines so that a ratio of the displacements of two minimum grouped cylinders is obtained. The variable-pitch transmission has a displacement stroke extending between a start of travel and an end of travel, the minimum volumetric ratio of two grouped cylinders being obtained at the end of travel of the variable timing transmission, this volumetric ratio being calculated by the following formula: V ⁢ 1 + V ⁢ 2 - Vr α . ⁢ maximum + ve ve + Goes α . ⁢ maximum = P minimum
Figure imgb0001
in which
  • V1: cylinder capacity of the large cylinder of the two grouped cylinders.
  • V2: cylinder capacity of the small cylinder of the two grouped cylinders.
  • Ve: volume of the dead space of the two grouped cylinders allowing the transfer of gas between the rolls without excessive rolling.
  • (αmaximum): angular advance of the crank of the second crankshaft line, at the end of the travel of the variable-pitch transmission.
  • Vr (αmaximum): end-of-stroke air discharge volume of the variable-pitch transmission, defined by the angular advance of the crank of the second crankshaft line when the crank shaft crankshaft is is at the low dead point in the end phase of admission.
  • Va (αmaximum): additional volume added to the volume of the dead space (24) at the end of travel of the variable-pitch transmission, defined by the angular advance of the crank of the second crankshaft line when the The crankshaft crankshaft is at the top dead center, in the late stage of compression.

Avantageusement, la transmission à calage variable comprend trois éléments concentriques superposés, à savoir un élément interne constitué par un arbre de transmission, un élément externe constitué par un manchon portant un engrenage pour l'accouplement des deux lignes d'arbres vilebrequins, et un élément intermédiaire situé entre lesdits éléments interne et externe et constitué d'un tube coulissant par rapport aux dits éléments interne et externe, le manchon étant maintenu dans un palier applique , au moyen d'un roulement. La seconde ligne d'arbre vilebrequin présente un arbre dont une extrémité est jointive à une extrémité de l'arbre de transmission, lesdites extrémités présentant des cannelures droites mâles et femelles correspondantes pour permettre leur accouplement et l'auto centrage des trois éléments de la transmission à calage variable par rapport à l'arbre de la seconde ligne d'arbre vilebrequin lors de la fixation du palier applique dans un orifice prévu du carter cylindre, ce moyen, suivant une forme de réalisation, permettant le montage et le démontage de la transmission à calage variable sans devoir démonter la seconde ligne d'arbre vilebrequin.Advantageously, the variable-pitch transmission comprises three superimposed concentric elements, namely an internal element constituted by a transmission shaft, an external element consisting of a sleeve carrying a gear for coupling the two lines of crankshafts, and an element intermediate between said inner and outer elements and consisting of a sliding tube relative to said inner and outer elements, the sleeve being held in a bearing bearing, by means of a bearing. The second crankshaft shaft has a shaft whose end is joined to one end of the transmission shaft, said ends having corresponding male and female straight splines to allow coupling and self centering of the three elements of the transmission. variable pitch relative to the shaft of the second crankshaft line when attaching the bearing applied in an orifice provided the cylinder block, this means, according to one embodiment, allowing the assembly and disassembly of the transmission variable pitch without having to disassemble the second crankshaft shaft line.

Un palier porte une bague de fixation formant le logement de la bague extérieure d'un roulement dont la bague intérieure est fixée sur le manchon de manière à maintenir l'arbre de transmission. Une entretoise s'étend entre la bague intérieure du roulement et la bague intérieure du roulement, cette entretoise compensant l'espace séparant entre lesdites bagues et maintenant axialement la bague de roulement contre un épaulement que présente le manchon, tandis qu'un seul écrou assure la fixation des bagues intérieures du roulement et du roulement et de l'entretoise sur le manchon.
L'arbre de transmission présente du côté de la bague de fixation des cannelures droites sur lesquelles vient s'emmancher le tube coulissant présentant sur sa face interne des cannelures droites de manière à coulisser linéairement sur l'arbre de transmission le manchon comporte sur sa face interne des cannelures hélicoïdales.
Le tube coulissant présente une extrémité dégagée en permanence hors du manchon, ladite extrémité étant solidaire d'une bague intérieure d'un roulement à deux rangées à contacts obliques, la bague extérieure du roulement étant solidaire d'une pièce d'attache au vérin. Les cannelures hélicoïdales sont agencées de sorte que le tube coulissant en se déplaçant hors du manchon diminue l'avance angulaire de la manivelle de la seconde ligne d'arbre à vilebrequin par rapport à la manivelle de la première ligne d'arbre à vilebrequin.A bearing carries a fixing ring forming the housing of the outer ring of a bearing whose inner ring is fixed on the sleeve so as to maintain the drive shaft. A spacer extends between the inner ring of the bearing and the inner ring of the bearing, this spacer compensating the space separating between said rings and maintaining the bearing ring axially against a shoulder that the sleeve presents, while a single nut ensures fixing the inner rings of the bearing and the bearing and the spacer on the sleeve.
The transmission shaft has on the side of the fixing ring straight splines on which is slipped the sliding tube having on its inner face straight splines so as to slide linearly on the transmission shaft the sleeve has on its face. internal helical grooves.
The sliding tube has an end permanently disengaged from the sleeve, said end being secured to an inner ring of a two row angular contact bearing, the outer ring of the bearing being secured to an attachment piece to the jack. The helical splines are arranged so that the sliding tube moving out of the sleeve decreases the angular advance of the crank of the second crankshaft line relative to the crank of the first crankshaft line.

Selon une particularité pour un moteur à allumage par compression, le moteur comprend au moins un injecteur de carburant dans l'espace mort, l'injection du carburant est effectuée en prise à demi-vitesse avec le vilebrequin à grande course.According to a feature for a compression ignition engine, the engine comprises at least one fuel injector in the dead space, the fuel injection is carried out at half speed with the crankshaft with a large stroke.

Selon une autre particularité, l'allumage est commandé et comprend au moins une bougie d'allumage dans l'espace mort, l'allumage étant effectué en synchronisme à demi-vitesse avec la première ligne d'arbre à vilebrequin.According to another feature, the ignition is controlled and comprises at least one spark plug in the dead space, the ignition being carried out in synchronism at half speed with the first crankshaft line.

Par exemple, le moteur présente un rapport entre les cylindrées des deux cylindres groupés (2,3) entre 1/10 et 9/10, avantageusement entre 1/5 et 3/5.For example, the engine has a ratio between the displacements of the two grouped cylinders (2, 3) between 1/10 and 9/10, advantageously between 1/5 and 3/5.

Selon un autre détail d'une forme de réalisation, le moteur comprend un carter d'huile (27) qui englobe l'ensemble des deux vilebrequins par le dessous du carter cylindre.According to another detail of an embodiment, the engine comprises an oil sump (27) which includes all of the two crankshafts from below the cylinder block.

Selon une particularité, le moteur à combustion interne à quatre temps comprend un carter d'huile situé en dessous de l'arbre vilebrequin des pistons des cylindres de la première série, tandis que l'arbre vilebrequin des pistons des cylindres de la deuxième série est enfermé dans le carter cylindre au dessus d'une face du carter cylindre et à un niveau situé au-dessus du carter d'huile, ladite face étant inclinée vers le carter d'huile, ladite face inclinée du carter cylindre étant avantageusement équipée d'un panneau d'accès à l'arbre vilebrequin des pistons des cylindres de la deuxième série.According to one feature, the four-stroke internal combustion engine comprises an oil sump located below the crankshaft of the cylinder pistons of the first series, while the crankshaft of the piston pistons of the second series is enclosed in the cylinder block above a face of the cylinder block and at a level located above the oil sump, said face being inclined towards the oil sump, said inclined face of the cylinder block being advantageously equipped with an access panel to the crankshaft of the pistons of the cylinders of the second series.

Selon une autre particularité d'un moteur à combustion interne à quatre temps, le moteur comporte un vérin de commande de la transmission à calage variable, ladite transmission à calage variable se situant avantageusement à l'avant du moteur sans passer par le volant situé à l'arrière du moteur.According to another feature of a four-stroke internal combustion engine, the engine comprises a variable-pitch transmission control cylinder, said variable-pitch transmission advantageously located at the front of the engine without passing through the steering wheel located at the back of the engine.

Selon toujours une autre particularité, le moteur à combustion interne à quatre temps comporte deux carters distincts, à savoir un carter d'accouplement et un carter cylindre, de telle façon que les deux éléments précités soient assemblés côte à côte, dans la direction axiale des arbres vilebrequins. Avantageusement, le moteur comporte un volant moteur monté au moyen d'un emboîtement concentrique axé sur l'arbre du grand vilebrequin. De préférence, le carter d'accouplement est mobile par rapport au carter cylindre de manière à le positionner angulairement sur le carter cylindre par des moyens de fixation, en particulier prévus sur le pourtour des parties jointives des deux carters précités.According to another feature, the four-stroke internal combustion engine comprises two separate casings, namely a coupling casing and a cylinder block, so that the two abovementioned elements are assembled side by side in the axial direction of the casings. crankshafts. Advantageously, the engine comprises a flywheel mounted by means of a concentric engagement centered on the shaft of the large crankshaft. Preferably, the coupling housing is movable relative to the cylinder block so as to angularly position it on the cylinder block by fastening means, in particular provided on the periphery of the contiguous portions of the two aforementioned casings.

Selon un détail d'une autre forme de réalisation, le moteur à combustion interne à quatre temps comprend un carter d'accouplement et un carter cylindre formant un seul élément non divisible, et un carter d'huile se situant en dessous des deux carters précités et adapté pour être démonté, de manière que le démontage du dit carter d'huile libère également le dessous du carter d'accouplement.According to a detail of another embodiment, the four-stroke internal combustion engine comprises a coupling housing and a crankcase forming a single non-divisible element, and an oil sump lying below the two said casings and adapted to be disassembled, so that disassembly of said oil pan also releases the underside of the coupling housing.

L'invention a encore pour objet un engin ou un appareil ou une machine muni d'un ou de plusieurs moteurs suivant l'invention.The invention further relates to a machine or an apparatus or a machine provided with one or more motors according to the invention.

Des particularités et détails de formes de réalisation ressortiront de la description suivante.Features and details of embodiments will become apparent from the following description.

DESCRIPTION DE FORMES DE REALISATION PREFEREESDESCRIPTION OF PREFERRED EMBODIMENTS

La présente invention concerne des moyens mieux appropriés à la régulation des couples instantanés entre les deux vilebrequins du moteur à rapport volumétrique variable.The present invention relates to more suitable means for regulating the instantaneous couples between the two crankshafts of the variable volumetric ratio engine.

Pour se faire, la transmission à calage variable est accouplée au volant du moteur et placé en interposition entre le volant du moteur et l'arbre du vilebrequin à grande course.To do this, the variable-pitch transmission is coupled to the engine flywheel and placed in interposition between the engine flywheel and the crank shaft with a large stroke.

Des moyens sont prévus pour que le déplacement du vérin hydraulique sur la commande de la transmission à calage variable fasse varier la position angulaire entre les deux arbres des deux vilebrequins pour qu'elle se réalise sans le moindre effort axial sur l'arbre du petit vilebrequin.Means are provided so that the displacement of the hydraulic cylinder on the control of the variable pitch transmission varies the angular position between the two shafts of the two crankshafts so that it is achieved without the slightest axial effort on the shaft of the small crankshaft .

Selon l'invention, ce nouveau moteur comporte deux lignes d'arbres vilebrequins, l'une à manivelle à grande course, l'autre à manivelle à petite course. Les deux vilebrequins sont accouplés sur le volant du moteur à même vitesse de rotation au moyen d'un train d'engrenages et d'une transmission à calage variable dont le pignon d'accouplement faisant partie du train d'engrenages se déplace angulairement par rapport à l'arbre vilebrequin à petite course, ce qui autorise un nombre infini de calages entre les deux vilebrequins sans nécessiter l'interruption de la transmission entre ces derniers.According to the invention, this new engine comprises two lines of crankshafts, one with a crank with a large stroke, the other crank with short stroke. The two crankshafts are coupled to the flywheel of the engine at the same rotational speed by means of a gear train and a variable timing transmission whose coupling gear forming part of the gear train moves angularly relative to to the short-stroke crankshaft, which allows an infinite number of wedges between the two crankshafts without requiring interruption of transmission between them.

Selon l'invention l'accouplement de l'arbre de la transmission à calage variable est placé à l'intérieur du premier palier de l'arbre du vilebrequin à petite course, de façon à favoriser une plus grande précision axiale et un moindre encombrement du dit accouplement.According to the invention, the coupling of the shaft of the variable-pitch transmission is placed inside the first bearing of the short-stroke crankshaft, so as to promote a greater axial precision and a smaller space requirement. says mating.

Selon l'invention, la transmission à calage variable est disposée et fixée dans le carter cylindre de telle manière que l'accouplement de la transmission à calage variable puisse déborder dans le carter d'accouplement à côté du volant du moteur. La transmission à calage variable est conçue de telle manière qu'elle puisse être séparée du carter moteur indépendamment de l'arbre du vilebrequin à petite course, de l'arbre du vilebrequin à grande course et du volant du moteur.According to the invention, the variable pitch transmission is arranged and fixed in the cylinder block in such a way that the coupling of the variable timing transmission can overflow into the coupling case next to the engine flywheel. The variable timing transmission is designed such that it can be separated from the crankcase independently of the short stroke crankshaft shaft, the long stroke crankshaft shaft and the engine flywheel.

Il est avantageusement prévu, à côté du volant du moteur, un couvercle de fermeture sur le carter d'accouplement, le dit couvercle de fermeture servant aussi comme support de fixation du vérin de pilotage de la transmission à calage variable. Le démontage du couvercle de fermeture du carter d'accouplement rendant accessible la transmission à calage variable fixée sur le carter cylindre. Le démontage de la transmission à calage variable du carter cylindre se réalise comme un ensemble mécanique interchangeable sans que ne soit rendu nécessaire le démontage du carter d'accouplement.It is advantageously provided, next to the flywheel of the engine, a closing cover on the coupling housing, said closure cover also serving as a mounting bracket for the driving cylinder of the variable-pitch transmission. Disassembly of the closing cover of the coupling housing making accessible the variable-pitch transmission fixed on the cylinder block. Disassembly of the variable-pitch transmission of the cylinder block is realized as an interchangeable mechanical assembly without the need to disassemble the coupling housing.

Selon l'invention, les deux cylindres groupés, différenciés par leur cylindrée, sont disposés en forme de V inversé. Les deux cylindres groupés sont accolés par leur point mort haut de façon à former dans le carter cylindre une chambre de combustion commune afin de permettre aux gaz de passer de l'un à l'autre de ces cylindres indépendamment de la position des pistons. Le moteur peut disposer également de plusieurs groupes de deux cylindres dont chacun des cylindres se situe au-dessus de l'une des deux lignes d'arbres vilebrequins. La manivelle du vilebrequin à petite course opérant avec la bielle du piston du plus petit cylindre, la manivelle du vilebrequin à grande course opérant avec la bielle du piston du plus grand cylindre.According to the invention, the two grouped cylinders, differentiated by their displacement, are arranged in inverted V-shape. The two cylinders grouped are contiguous by their top dead center so as to form in the cylinder block a common combustion chamber to allow the gas to pass from one to the other of these cylinders regardless of the position of the pistons. The engine may also have several groups of two cylinders, each of the cylinders is located above one of the two rows of crankshafts. The crankshaft crankshaft with small stroke operating with the piston rod of the smaller cylinder, the crankshaft crankshaft with large stroke operating with the piston rod of the largest cylinder.

Selon l'invention, en version à allumage par compression, le moteur comprend au moins un injecteur de carburant dans l'espace mort, l'injection du carburant est effectuée en prise à demi-vitesse avec le vilebrequin à grande course.According to the invention, in a compression-ignition version, the engine comprises at least one fuel injector in the dead space, the fuel injection is carried out at half speed with the crankshaft with a large stroke.

Selon l'invention, en version à allumage commandé, le moteur comprend au moins une bougie d'allumage dans l'espace mort, l'allumage est effectué par des moyens connus en synchronisme à demi-vitesse avec le vilebrequin à grande course.According to the invention, in the spark ignition version, the engine comprises at least one spark plug in the dead space, the ignition is carried out by known means in synchronism at half speed with the crankshaft with a large stroke.

Conformément à la présente invention, la distribution est assurée au moins par un arbre à cames en prise à demi-vitesse avec le vilebrequin à grande course, mettant en communication périodique le groupe des deux cylindres avec les conduites d'admission et d'échappement (non représentées) au moyen des soupapes d'admission et d'échappement (non représentées) à des moments précis du cycle à quatre temps. La phase de détente est effectuée simultanément sur chaque piston des deux cylindres groupés faisant coopérer les deux vilebrequins à l'effort moteur. Les deux vilebrequins sont mis en liaison directe avec les organes de transmission externes du moteur, de telle sorte que la transmission à calage variable ne transmette que le couple moteur du vilebrequin à petite course sur le volant du moteur sans passer sur la ou les manivelles de l'arbre du grand vilebrequin. Les différents décalages angulaires de la transmission à calage variable entre les deux vilebrequins ont pour effet de modifier, en phase fin de compression (point mort haut du piston de la plus grande cylindrée), un espace additionnel engendré dans la plus petite cylindrée.. Cet espace additionnel étant défini avec l'espace mort, de façon à modifier le rapport volumétrique du moteur dans le sens maximal en début de course de la transmission à calage variable, et dans le sens minimal en fin de course de la transmission à calage variable.According to the present invention, the distribution is ensured at least by a camshaft engaged at half speed with the crankshaft with a large stroke, periodically communicating the group of two cylinders with the intake and exhaust pipes ( not shown) by means of the intake and exhaust valves (not shown) at specific times in the four-stroke cycle. The expansion phase is carried out simultaneously on each piston of the two cylinders grouped making the two crankshafts cooperate with the engine force. The two crankshafts are put in direct connection with the external transmission members of the engine, so that the variable-pitch transmission transmits only the engine torque of the crankshaft at short stroke on the engine flywheel without passing over the crank handle (s). the tree of the big crankshaft. The various angular offsets of the variable-pitch transmission between the two crankshafts have the effect of modifying, in the fine compression phase (top dead center of the piston of the largest displacement), an additional space generated in the smallest displacement. additional space being defined with the dead space, so as to modify the volumetric ratio of the engine in the maximum direction at the beginning of travel of the variable-pitch transmission, and in the minimum direction at the end of the travel of the variable-pitch transmission.

Suivant la présente invention,, un amplificateur de force hydraulique dont le vérin asservi agit sur la transmission à calage variable, modifie le volume additionnel de la petite cylindrée proportionnellement à la pression de suralimentation, de manière à maintenir le moteur dans des conditions de fonctionnement optimales avec le minimum de pollution.According to the present invention, a hydraulic force amplifier whose slave cylinder acts on the variable-pitch transmission, modifies the additional volume of the small displacement in proportion to the supercharging pressure, to maintain the engine under optimal operating conditions with minimum pollution.

Egalement suivant l'invention, un programme préétabli sur un moteur de présérie permet d'éliminer les contraintes excessives des pressions et des températures. Chaque régime du moteur est mémorisé dans une échelle de progression par points, de façon à englober toutes les capacités du moteur. Chaque point de mémorisation est une combinaison formée par les mesures de quatre capteurs : la pression de l'air d'admission, la température de l'air d'admission, la vitesse du moteur et la température du moteur. Chaque combinaison est enregistrée simultanément avec la position du vérin de commande de la transmission à calage variable. Ce programme permet le pilotage automatique du moteur de série identique à celui du moteur réalisé au banc d'essai. Les spécifications du carburant doivent également être identiques pour reproduire exactement les mêmes conditions de fonctionnement sur le moteur de série, grâce à une surveillance à haute fréquence des mesures des quatre capteurs.Also according to the invention, a pre-established program on a pre-series engine makes it possible to eliminate the excessive stress of pressures and temperatures. Each engine speed is stored in a ladder progression ladder, so as to encompass all engine capabilities. Each storage point is a combination of four sensor measurements: intake air pressure, intake air temperature, engine speed, and engine temperature. Each combination is recorded simultaneously with the position of the control cylinder of the variable timing transmission. This program allows the automatic piloting of the engine of series identical to that of the engine carried out with the test bench. The fuel specifications must also be identical to reproduce exactly the same operating conditions on the standard engine, thanks to high frequency monitoring of the measurements of the four sensors.

Selon l'invention, un aménagement de la transmission à calage variable est prévu pour perfectionner le dispositif de commande de l'angle de phase entre un premier et deuxième vilebrequins. Ce moyen est défini par une nouvelle forme d'espacement entre les deux vilebrequins, de manière à engendrer le débordement de la transmission à calage variable à côté du volant du moteur. La transmission à calage variable est pourvue d'un vérin de pilotage en prise directe, pour contrôler l'angle de phase entre le vilebrequin à petite course et le vilebrequin à grande course.According to the invention, an arrangement of the variable pitch transmission is provided to improve the control device of the phase angle between a first and second crankshaft. This means is defined by a new form of spacing between the two crankshafts, so as to cause the overflow of the variable timing transmission next to the engine flywheel. The variable-pitch transmission is equipped with a direct-drive pilot cylinder to control the phase angle between the short-stroke crankshaft and the long-stroke crankshaft.

Conformément à la présente invention, le rapport dimensionnel entre les deux cylindrées des deux cylindres groupés peut se situer au moins entre 1/10 et 9/10, de préférence entre 1/5 et 3/5 suivant le degré de pression de suralimentation maximal prévu pour le moteur. La configuration du moteur à rapport volumétrique variable présente les axes des deux cylindres groupés disposés sous la forme d'un V inversé asymétrique par rapport au plan de culasse. L'angle d'ouverture entre les axes des deux cylindres groupés peut être adapté entre 1 et 60 degrés au minimum selon les exigences dues à l'encombrement des pièces fixes et mobiles des attelages des deux vilebrequins.According to the present invention, the dimensional ratio between the two displacements of the two grouped cylinders can be at least between 1/10 and 9/10, preferably between 1/5 and 3/5 depending on the degree of maximum supercharging pressure provided. for the engine. The configuration of the variable volumetric ratio engine has the axes of the two grouped cylinders arranged in the form of an inverted V asymmetric with respect to the plane of the cylinder head. The opening angle between axes of the two cylinders grouped can be adapted between 1 and 60 degrees minimum according to the requirements due to the size of the fixed and movable parts of the couplings of the two crankshafts.

Suivant la présente invention, l'arrangement des axes des deux cylindres groupés dans le carter cylindre du moteur se présente sous deux options différentes: la première option du moteur dispose de deux cylindres groupés axés en forme de V inversé asymétriques mais dont seul l'axe du plus grand des deux cylindres est fixé perpendiculairement au plan de culasse, le piston du petit cylindre est pourvu d'un bossage rectificatif du contour de la chambre de combustion de manière à réaliser au point mort haut, en phase fin de compression, la forme et le volume minimum de la chambre de combustion, il est également prévu un creux sur le piston du grand cylindre axé perpendiculairement au plan de culasse. Le creux et le bossage des dits pistons sont avantageusement agencés de manière à ne pas obturer l'orifice de communication des deux cylindres groupés lorsque les dits pistons sont positionnés au point mort haut.According to the present invention, the arrangement of the axes of the two cylinders grouped in the crankcase of the engine is presented under two different options: the first option of the engine has two cylinders grouped oriented in inverted V-shaped asymmetric but of which only the axis the larger of the two cylinders is fixed perpendicular to the plane of the cylinder head, the piston of the small cylinder is provided with a rectifying boss of the contour of the combustion chamber so as to achieve the top dead center, in the thin phase of compression, the shape and the minimum volume of the combustion chamber, there is also provided a recess on the piston of the large cylinder oriented perpendicularly to the plane of the cylinder head. The hollow and the boss of said pistons are advantageously arranged so as not to close the communication port of the two cylinders grouped when said pistons are positioned at top dead center.

Il peut être également prévu dans la première option précitée, une dispense de bossage sur l'un des pistons des deux cylindres groupés lorsqu'il est prévu dans la culasse un évidemment compensatoire, de même forme et même grandeur que le dépassement du dit piston.It may also be provided in the aforementioned first option, a boss relief on one of the pistons of the two cylinders grouped when there is provided in the cylinder head a compensating obviously, of the same shape and same size as exceeding said piston.

La deuxième option du moteur se présente avec les axes des deux cylindres groupés en forme de V inversé asymétriques non disposés perpendiculairement au plan de culasse. Il est prévu sur le haut des pistons une arête tronquée avec un jeu de tolérance parallèle au plan de culasse lorsque les dits pistons sont situés au point mort haut. L'espace compris entre les plans non tronqués des deux pistons situés au point mort haut et le plan de culasse forme la chambre de combustion.The second option of the engine is with the axes of the two asymmetrical inverted V-shaped cylinders not arranged perpendicularly to the plane of the cylinder head. There is provided on the top of the pistons a truncated edge with tolerance clearance parallel to the bolt plane when said pistons are located at the top dead center. The space between the untrimmed planes of the two pistons located at top dead center and the plane of the cylinder head forms the combustion chamber.

Suivant l'invention, suivant les deux options précitées, et suivant le nombre de deux cylindres groupés axés en forme de V inversé asymétrique, le cylindre du vilebrequin à grande course et le cylindre du vilebrequin à petite .course sont accolés l'un à l'autre par leur point mort haut, de manière à créer une chambre de combustion commune à ces deux cylindres groupés. La chambre de combustion étant unifiée à ces dits cylindres par un évidement ou canal au niveau de la jointure jusqu'au plan de culasse ou au-delà du plan de culasse, de manière à ce que les gaz d'admission et de combustion puissent communiquer en permanence entre les dits cylindres et la chambre de combustion, quelle que soit la position des pistons dans le cycle à quatre temps.According to the invention, according to the two aforementioned options, and according to the number of two asymmetrical inverted V-shaped grouped cylinders, the cylinder of the large-stroke crankshaft and the cylinder of the small-stroke crankshaft are joined to each other by their top dead center, so as to create a combustion chamber common to these two cylinders grouped. The combustion chamber being unified with said cylinders by a recess or channel at the joint to the cylinder head plane or beyond the cylinder head plane, so that the intake and combustion gases can communicate continuously between said cylinders and the combustion chamber, regardless of the position of the pistons in the four-stroke cycle.

Le volant du moteur est axé et fixé sur l'extrémité de l'arbre du grand vilebrequin à l'arrière du moteur; la transmission à calage variable du moteur est axée sur l'extrémité de l'arbre, du coté du volant du moteur. L'accouplement entre le petit vilebrequin et le volant du moteur s'effectue solidairement au dit volant via la transmission à calage variable permettant au dit volant du moteur de régulariser simultanément les couples de chacun des deux vilebrequins indépendamment l'un de l'autre.The engine flywheel is focused and attached to the end of the large crankshaft shaft at the rear of the engine; the variable-pitch engine transmission is focused on the end of the shaft, on the side of the engine flywheel. The coupling between the small crankshaft and the flywheel of the engine is carried out integrally with said flywheel via the variable-pitch transmission allowing the said flywheel of the engine to simultaneously regulate the pairs of each of the two crankshafts independently of one another.

Suivant la présente invention, suivant les deux options précitées, l'architecture du moteur se réalise suivant les exigences de la distance de séparation entre les deux arbres des deux vilebrequins. A moindre distance de séparation entre les deux engrenages axés sur leur vilebrequin respectif, ces derniers sont accouplés en prise directe à la même vitesse de rotation. A plus grande distance de séparation entre les deux vilebrequins, une chaîne cinématique, composée de deux engrenages d'accouplement complémentaires entre les deux engrenages axés sur leur vilebrequin respectif, est prévue pour déterminer également un accouplement à la même vitesse de rotation.According to the present invention, according to the two aforementioned options, the engine architecture is realized according to the requirements of the separation distance between the two shafts of the two crankshafts. At a lower separation distance between the two gears focused on their respective crankshaft, the latter are coupled in direct drive at the same rotational speed. At a greater separation distance between the two crankshafts, a kinematic chain, composed of two complementary coupling gears between the two gears geared to their respective crankshaft, is provided to also determine a coupling at the same speed of rotation.

Suivant l'invention, suivant les deux options précitées, le moyen d'un vérin de commande est également valable lorsque la transmission à calage variable se situe à l'avant du moteur, de manière à.pouvoir faire varier le calage angulaire entre les deux vilebrequins sans passer par l'intermédiaire du volant situé à l'arrière du moteur.According to the invention, according to the two aforementioned options, the means of a control jack is also valid when the variable-pitch transmission is at the front of the engine, so as to be able to vary the angular setting between the two. crankshafts without passing through the steering wheel located at the rear of the engine.

L'invention sera décrite plus en détail à l'aide de la description qui suit et au regard de 7 dessins et un schéma annexés de deux formes de réalisation spécifiques données à titre d'exemple uniquement représentant deux options du moteur. Dans ces dessins:

  • La figure 1 représente une vue en coupe transversale du carter cylindre (1) d'un moteur. Pour la clarté du dessin, les contrepoids (28) ne sont pas représentés sur les vilebrequins (4,5). Les deux cylindres groupés (2,3) sont axés en forme de V inversé asymétrique et dont l'axe du plus grand des deux cylindres (2) se situe perpendiculairement au plan de culasse (29). La chambre de combustion (24) commune à ces deux cylindres groupés (2,3) est située dans le carter cylindre (1). Dans la chambre de combustion (24) est inclus un orifice (32). Il est aussi prévu un creux (non représenté) sur le piston (6) du cylindre (2) situé perpendiculairement au plan de culasse. Un bossage (11) est prévu sur le piston (8) du cylindre (3). Les pistons (6,8) sont positionnés en phase de détente pour discerner les intervalles entre les deux attelages des vilebrequins (4,5). L'ouverture axiale des deux cylindres groupés (2,3) en forme de V inversé asymétrique est définie à 30 degrés. L'axe A des grands cylindres (2) est perpendiculaire au plan de joint de culasse 29. Le passage ou canal (32) est formé dans le carter pour s'étendre pour chaque groupe de cylindres (2,3), entre un petit cylindre et un grand cylindre.
  • La figure 2 représente une vue en plan du carter cylindre de la figure 1. On peut voir en perspective les 4 groupes de deux cylindres. La coupe ou arrachement partiel permet de voir la transmission à calage variable (10) ainsi que les engrenages (14,16) des deux vilebrequins (4,5) sans les deux engrenages de liaison intermédiaires (non représentés). Les pistons ont été représentés en phase d'échappement afin de démontrer l'espace nécessaire entre les attelages des deux vilebrequins (4,5) et les parois latérales du carter cylindre. On peut réaliser le dégagement entre la transmission à calage variable (10) et le volant du moteur (26) en fonction de l'ouverture angulaire des deux cylindres groupés (2,3) axés en forme de V inversé asymétrique située à 30 degrés. Le canal 32 a une largeur moyenne (largeur mesurée perpendiculairement à la droite passant par le point d'intersection de l'axe du grand cylindre avec le plan de joint de culasse et par le point d'intersection de l'axe du petit cylindre avec le plan de joint de culasse) comprise entre 0,5 et 0,8 fois la moyenne des diamètres des cylindres. La largeur moyenne est déterminée avantageusement au niveau du plan de joint de culasse. De préférence, la largeur minimale du canal au niveau du plan de joint de culasse (29) est avantageusement comprise entre 0,3 fois et 1 fois, en particulier entre 0,5 et 0,8 fois la moyenne dés diamètres des cylindres d'un groupe. Le volume d'un canal est compris entre 2% et 15% du volume mort minimal avec les deux pistons en position mort haut.
  • La figure 3 représente une vue en coupe transversale du carter cylindre (1). Pour la clarté du dessin, les contrepoids (28) ne sont pas représentés sur les vilebrequins (4,5). On peut distinguer les deux cylindres groupés (2,3) axés en forme de V inversé asymétrique dont les axes de ces cylindres ne sont pas situés perpendiculairement au plan de culasse (29). La chambre de combustion (24) commune à ces deux cylindres groupés (2,3) est située dans le carter cylindre (1) avec sur le haut de chacun de ces pistons (6,8) une arête tronquée limitée par le plan de culasse (29). Dans la chambre de combustion (24) est inclus un orifice (32). Les pistons ont été représentés en phase de détente afin de démontrer l'espace nécessaire entre les attelages des deux vilebrequins (4,5). L'ouverture axiale des deux cylindres groupés (2,3) en forme de V inversé asymétrique, a été définie sur une ouverture angulaire de 24 degrés avec une répartition de 9 degrés pour le grand cylindre et 15 degrés pour le petit cylindre par rapport au plan de culasse (29). On peut réaliser le dégagement entre la transmission à calage variable (10) et le volant du moteur (26) en fonction de l'ouverture angulaire des deux cylindres groupés (2,3) axés en forme de V inversé asymétrique située à 24 degrés.
  • La figure 4 représente une vue en plan du carter cylindre de la figure 3. On peut voir en perspective les 4 groupes de deux cylindres (2,3). Le crevé partiel permet de voir la transmission à calage variable (10) ainsi que les engrenages (14,16) des deux vilebrequins (4,5) sans les deux engrenages de liaison intermédiaires (non représentés). Les pistons (6,8) sont positionnés en phase d'échappement pour représenter les intervalles entre les deux attelages des vilebrequins (4,5) et les parois latérales du carter cylindre (1). On peut réaliser le dégagement entre la transmission à calage variable (10) et le volant du moteur (26) en fonction de l'ouverture angulaire des deux cylindres groupés (2,3) axés en forme de V inversé asymétrique située à 24 degrés. Les axes des cylindres (2,3) ne sont pas perpendiculaires au plan de joint de culasse. Par rapport à une droite perpendiculaire au plan de joint de culasse, l'axe du grand cylindre (2) est avantageusement moins incliné que l'axe du petit cylindre (3).
  • La figure 5 représente une vue en coupe parallèle à l'axe de la transmission à calage variable. On peut voir sur l'extrémité de l'arbre (12) les cannelures externes de la transmission à calage variable.
  • La figure 6 représente une vue en coupe partielle de la transmission à calage variable dont l'arbre d'accouplement (12) est intégré à l'arbre du vilebrequin à petite course (5).
  • La figure 7 est une vue en coupe et en perspective de la transmission à calage variable intégrée à l'arbre du vilebrequin à petite course où l'on peut distinguer les canaux de lubrification.
  • La figure 8 est un schéma qui révèle 32 combinaisons possibles pour aménager la construction du moteur à rapport volumétrique variable.
The invention will be described in more detail with the help of the description which follows and with respect to 7 appended drawings and a diagram of two specific embodiments given by way of example only, representing two options of the engine. In these drawings:
  • The figure 1 represents a cross-sectional view of the cylinder block (1) of an engine. For the sake of clarity, the counterweights (28) are not shown on the crankshafts (4,5). The two grouped cylinders (2, 3) are oriented in the form of an asymmetric inverted V and whose axis of the largest of the two cylinders (2) is perpendicular to the plane of the cylinder head (29). The combustion chamber (24) common to these two grouped cylinders (2,3) is located in the cylinder block (1). In the combustion chamber (24) is included an orifice (32). There is also provided a recess (not shown) on the piston (6) of the cylinder (2) located perpendicular to the yoke plane. A boss (11) is provided on the piston (8) of the cylinder (3). The pistons (6,8) are positioned in the relaxation phase to discern the intervals between the two couplings crankshaft (4,5). The axial opening of the two asymmetric inverted V-shaped group cylinders (2,3) is set at 30 degrees. The axis A of the large cylinders (2) is perpendicular to the joint plane of the cylinder head 29. The passage or channel (32) is formed in the housing to extend for each group of cylinders (2,3), between a small cylinder and a large cylinder.
  • The figure 2 represents a plan view of the cylinder block of the figure 1 . We can see in perspective the four groups of two cylinders. The partial cut or tear allows to see the variable pitch transmission (10) and the gears (14,16) of the two crankshafts (4,5) without the two intermediate linkages (not shown). The pistons were shown in the exhaust phase to demonstrate the necessary space between the couplings of the two crankshafts (4,5) and the side walls of the cylinder block. The clearance between the variable pitch transmission (10) and the engine flywheel (26) can be achieved as a function of the angular aperture of the two asymmetric inverted V-shaped grouped cylinders (2,3) at 30 degrees. The channel 32 has an average width (width measured perpendicular to the line passing through the point intersection of the axis of the large cylinder with the joint plane of the cylinder head and the point of intersection of the axis of the small cylinder with the joint plane of the cylinder head) between 0.5 and 0.8 times the average cylinder diameters. The average width is advantageously determined at the level of the head gasket plane. Preferably, the minimum width of the channel at the yoke joint plane (29) is advantageously between 0.3 times and 1 time, in particular between 0.5 and 0.8 times the average diameter of the rolls of the cylinder. a group. The volume of a channel is between 2% and 15% of the minimum dead volume with both pistons in the top dead position.
  • The figure 3 represents a cross-sectional view of the cylinder block (1). For the sake of clarity, the counterweights (28) are not shown on the crankshafts (4,5). It is possible to distinguish the two asymmetric inverted V-shaped grouped cylinders (2, 3) whose axes of these cylinders are not located perpendicular to the plane of the cylinder head (29). The combustion chamber (24) common to these two grouped cylinders (2, 3) is located in the cylinder block (1) with on the top of each of these pistons (6, 8) a truncated edge bounded by the plane of the cylinder head (29). In the combustion chamber (24) is included an orifice (32). The pistons were shown during the relaxation phase to demonstrate the necessary space between the couplings of the two crankshafts (4,5). The axial opening of the two asymmetric inverted V-shaped bundles (2,3) was defined on an angular opening of 24 degrees with a distribution of 9 degrees for the large cylinder and 15 degrees for the small cylinder with respect to breech plane (29). The clearance between the variable pitch transmission (10) and the flywheel of the engine (26) can be achieved as a function of the angular aperture of the two asymmetric inverted V-shaped cluster cylinders (2,3) at 24 degrees.
  • The figure 4 represents a plan view of the cylinder block of the figure 3 . We can see in perspective the four groups of two cylinders (2,3). The partial puncture makes it possible to see the variable-pitch transmission (10) as well as the gears (14, 16) of the two crankshafts (4, 5) without the two intermediate linkages (not shown). The pistons (6,8) are positioned in the exhaust phase for represent the intervals between the two couplings of the crankshafts (4,5) and the side walls of the cylinder block (1). The clearance between the variable pitch transmission (10) and the flywheel of the engine (26) can be achieved as a function of the angular aperture of the two asymmetric inverted V-shaped cluster cylinders (2,3) at 24 degrees. The axes of the cylinders (2,3) are not perpendicular to the joint plane of the cylinder head. With respect to a straight line perpendicular to the yoke joint plane, the axis of the large cylinder (2) is advantageously less inclined than the axis of the small cylinder (3).
  • The figure 5 represents a sectional view parallel to the axis of the variable-pitch transmission. On the end of the shaft (12) can be seen the external splines of the variable pitch transmission.
  • The figure 6 is a partial sectional view of the variable-pitch transmission of which the coupling shaft (12) is integrated with the short-stroke crank shaft (5).
  • The figure 7 is a cross-sectional and perspective view of the variable-timing transmission integrated into the short-stroke crankshaft, where the lubrication channels can be distinguished.
  • The figure 8 is a diagram that reveals 32 possible combinations to develop the construction of the variable volumetric ratio engine.

En se référant aux figures de 1 à 7, le carter cylindre (1) comprend deux vilebrequins (4,5) disposés parallèlement, l'un à manivelle à grande course (4), l'autre à manivelle à petite course (5), les deux cylindres (2,3) munis respectivement de pistons (6,8) et respectivement de bielles (7,9) sont chacun disposés au-dessus des deux lignes d'arbres vilebrequins (4 et 5). La manivelle du vilebrequin à petite course (5) supportée par les paliers (20) opérant avec la bielle (9) du piston (8) du plus petit cylindre (3), la manivelle du vilebrequin à grande course (4) supportée par les paliers (21) opérant avec la bielle (7) du piston (6) du plus grand cylindre (2). Les axes des deux cylindres groupés (2,3) sont disposés dans le carter cylindre (1) sous la forme d'un V inversé asymétrique par rapport au plan de la culasse (29). On peut constater que les deux cylindres précités sont également accolés l'un à l'autre au moyen d'un espace mort relatif à la chambre de combustion commune (24). Le passage des gaz entre les dits cylindres (2,3) est effectué par un orifice ou canal intérieur ou canal formé dans le carter cylindre (32) de la dite chambre de combustion.Referring to Figures 1 to 7, the cylinder block (1) comprises two crankshafts (4,5) arranged in parallel, one crank with a large stroke (4), the other crank with short stroke (5) , the two cylinders (2, 3) respectively provided with pistons (6,8) and respective connecting rods (7,9) are each disposed above the two lines of crankshafts (4 and 5). The small crankshaft crank (5) supported by the bearings (20) operating with the connecting rod (9) of the piston (8) of the smaller cylinder (3), the crankshaft of the large-stroke crankshaft (4) supported by the bearings (21) operating with the connecting rod (7) of the piston (6) of the largest cylinder (2). The axes of the two grouped cylinders (2, 3) are arranged in the cylinder block (1) in the form of an inverted V asymmetrical with respect to the plane of the cylinder head (29). It can be seen that the two aforementioned cylinders are also contiguous to each other by means of a dead space relative to the common combustion chamber (24). The passage of gases between said cylinders (2,3) is effected by an orifice or internal channel or channel formed in the cylinder block (32) of said combustion chamber.

Le rapport entre les cylindrées des deux cylindres groupés (2,3) sur les 4 figures est fixé à 2/5, ce qui détermine une portion de couple théorique de 2/7 pour la cylindre du petit cylindre (3) par rapport à la cylindrée totale des deux cylindres groupés (2,3). L'entraxe tête-pied des bielles par rapport à la course des pistons est fixé à 1,68. Le rapport course /alésage des cylindres est fixé à 1,21.The ratio between the displacements of the two cylinders grouped (2,3) in the 4 figures is set at 2/5, which determines a theoretical torque portion of 2/7 for the cylinder of the small cylinder (3) relative to the total displacement of the two cylinders grouped (2,3). The head-to-foot distance between the connecting rods and the piston stroke is 1.68. The stroke / bore ratio of the cylinders is set at 1.21.

Les dimensionnements des autres organes des deux options de moteurs ont été instruits à partir d'un type de moteur à allumage par compression largement éprouvé de 6 cylindres en ligne, à vitesse maximum de 2200 tours/minute, d'une puissance de 400 chevaux et validé sur un parcours de 1.500.000 kilomètres.The sizing of the other components of the two engine options were based on a widely tested 6-cylinder in-line type compression-ignition engine with a maximum speed of 2200 rpm and a horsepower of 400 horsepower. validated on a course of 1,500,000 kilometers.

En version à allumage par compression, le moteur comprend au moins un injecteur de carburant (non représenté) dans l'espace mort (24). L'injection du carburant est effectuée par des moyens connus (non représentés) en prise à demi-vitesse avec le vilebrequin à manivelle à grande course (4).In the compression ignition version, the engine comprises at least one fuel injector (not shown) in the dead space (24). The injection of the fuel is carried out by known means (not shown) engaged at half speed with the crank crankshaft with large stroke (4).

En version à allumage commandé, le moteur comprend au moins une bougie d'allumage (non représenté) dans l'espace mort (24). L'allumage est effectué par des moyens connus (non représentés) en synchronisme à demi-vitesse avec le vilebrequin à grande course (4).In the spark ignition version, the engine comprises at least one spark plug (not shown) in the dead space (24). The ignition is carried out by known means (not shown) in synchronism at half speed with the crankshaft with a large stroke (4).

Pour les moteurs à très grande cylindrée, un deuxième arbre à cames (non représenté) en prise à demi-vitesse avec le vilebrequin à grande course (4) peut être prévu dans la partie de la culasse (non représentée) surplombant le plus petit cylindre (3), de façon à assurer de secondes ouverture et fermeture périodiques de l'admission et de l'échappement au même moment que l'ouverture et la fermeture du cycle à quatre temps réalisées dans le plus grand cylindre (2). Le rapport entre les cylindrées des deux cylindres groupés (2,3) se situe au moins entre 1/10 et 9/10 de préférence entre 1/5 et 3/5 permettant d'adapter le moteur à des taux de pressions de suralimentation de 1 à 7.For very large displacement engines, a second camshaft (not shown) engaged at half speed with the long stroke crankshaft (4) may be provided in the part of the cylinder head (not shown) overhanging the smaller one cylinder (3), so as to ensure periodic second opening and closing of the inlet and the exhaust at the same time as the opening and closing of the four-stroke cycle carried out in the largest cylinder (2). The ratio between the displacements of the two grouped cylinders (2, 3) is at least between 1/10 and 9/10, preferably between 1/5 and 3/5, making it possible to adapt the engine to supercharging pressure ratios of 1 to 7.

La transmission à calage variable (10) est formée de trois éléments concentriques superposés: le premier élément est constitué par l'arbre de transmission (35) situé dans la partie interne le deuxième élément est constitué par le manchon (36) de l'engrenage (14) situé dans la partie externe et le troisième élément est constitué par le tube coulissant (17) situé dans la partie intermédiaire entre les deux autres éléments précités. Le dit manchon (36) est maintenu dans un palier applique (15) au moyen d'un roulement (39) à une rangées approprié entre le palier applique (15) et le manchon (36). Le dit palier applique (15) est fixé au carter cylindre (1) de manière que la transmission à calage variable (10) puisse constituer un ensemble séparé de l'arbre (13) du vilebrequin à petite course (5). A cet effet, le vilebrequin à petite course (5) et la transmission à calage variable (10) sont réalisés en liaison avec leur arbre respectif (12) et (13). La transmission à calage variable (10) est dotée d'un palier applique (15) qui se fixe par centrage dans un orifice prévu dans le carter cylindre (1) Les cannelures droites internes de l'arbre (12) situées dans le tourillon du palier (20) sont appariées avec les cannelures droites externes de l'arbre (13), afin de présenter les qualités de rigidité suffisantes de l'axe de la transmission à calage variable et un encombrement réduit de l'accouplement entre les deux arbres (12,13) ; cette disposition permettant le démontage de la transmission à calage variable hors du bloc moteur (1) sans devoir procéder au démontage du vilebrequin à petite course (5).The variable-pitch transmission (10) is formed of three superimposed concentric elements: the first element is constituted by the transmission shaft (35) located in the inner part the second element is constituted by the sleeve (36) of the gearing (14) located in the outer portion and the third member is constituted by the sliding tube (17) located in the intermediate portion between the two other aforementioned elements. The sleeve (36) is held in an applied bearing (15) by means of a bearing (39) in a suitable row between the bearing (15) and the sleeve (36). Said bearing (15) is fixed to the cylinder block (1) so that the variable pitch transmission (10) can constitute a separate assembly of the shaft (13) of the short-stroke crankshaft (5). For this purpose, the small-stroke crankshaft (5) and the variable-pitch transmission (10) are made in connection with their respective shaft (12) and (13). The variable-pitch transmission (10) is provided with an applied bearing (15) which is centrally fixed in an orifice in the cylinder block (1). The internal straight grooves of the shaft (12) are located in the trunnion of the cylinder. bearing (20) are matched with the external straight splines of the shaft (13), in order to have sufficient rigidity qualities of the axis of the variable-pitch transmission and a reduced bulk of the coupling between the two shafts ( 12,13); this arrangement allows the dismounting of the variable timing transmission out of the engine block (1) without having to disassemble the short-stroke crankshaft (5).

La substitution d'un accouplement sans support entre le vilebrequin à petite course (5) et la transmission à calage variable (10) par un accouplement avec support par le palier (20) du tourillon du vilebrequin à petite course (5) a pour avantage de limiter le roulement (39) à une seule rangée appropriée entre le palier applique (15) et le manchon (36).The substitution of an unsupported coupling between the short-stroke crankshaft (5) and the variable-pitch transmission (10) by a bearing-supported coupling (20) of the small-stroke crankshaft journal (5) has the advantage of limiting the bearing (39) to a single appropriate row between the bearing (15) and the sleeve (36).

L'arbre (35) et le manchon (36) sont avantageusement maintenus concentriquement et axialement l'un par rapport à l'autre au moyen d'un palier (40) solidaire de l'arbre (35). Le palier (40) est doté d'un roulement (43) à butée axiale et radiale permettant la rotation libre de l'arbre (35) indépendamment du manchon (36). Le palier (40) fait partie intégrante de l'arbre (35) à l'endroit où se limitent les cannelures droites (12) et (47). Le palier (40) et le manchon (36) sont situés à l'intérieur du carter moteur (1). Le palier (40) est réalisé sous la forme d'un disque régulièrement transpercé d'orifices permettant le boulonnage d'une bague (41) située sur la face du côté où se limitent les cannelures droites (47) de l'arbre (35). L'application de la bague (41) sur le palier (40) est mise à profit pour former un logement permettant la fixation de la bague extérieure (42) du roulement (43) à efforts axial et radial, tandis que la bague intérieure (44) du roulement (43) est fixée sur le manchon (36) contre une entretoise (45) en forme de bague entourant le manchon (36), l'entretoise (45) est destinée à rattraper l'espace de séparation entre la bague intérieure (44) du roulement (43) et la bague intérieure(37) du roulement (39), cette dernière étant maintenue axialement contre un épaulement prévu sur le manchon (36) par la fixation de toutes les pièces précitées au moyen d'un écrou (51) sur le manchon (36).The shaft (35) and the sleeve (36) are advantageously held concentrically and axially relative to each other by means of a bearing (40) integral with the shaft (35). The bearing (40) is provided with an axial and radial thrust bearing (43) for free rotation of the shaft (35) independently of the sleeve (36). The bearing (40) is an integral part of the shaft (35) where the straight splines (12) and (47) are limited. The bearing (40) and the sleeve (36) are located inside the crankcase (1). The bearing (40) is in the form of a disk regularly pierced with orifices for bolting a ring (41) located on the face of the side where the straight splines (47) of the shaft (35) are limited. ). The application of the ring (41) on the bearing (40) is used to form a housing for fixing the outer ring (42) of the bearing (43) axial and radial forces, while the inner ring ( 44) of the bearing (43) is fixed on the sleeve (36) against a spacer (45) in the form of a ring surrounding the sleeve (36), the spacer (45) is intended to catch the separation space between the ring inside (44) of the bearing (43) and the inner ring (37) of the bearing (39), the latter being held axially against a shoulder provided on the sleeve (36) by the fixing of all the aforementioned parts by means of a nut (51) on the sleeve (36).

L'engrenage (14) du manchon (36) est situé à l'extérieur du carter moteur (1) accouplé à même vitesse de rotation avec le vilebrequin à grande course (4) au moyen d'un engrenage (16) solidaire à ce dernier et de deux engrenages intermédiaires (non représentés) entre les deux engrenages précités (14,16).The gear (14) of the sleeve (36) is located outside the crankcase (1) coupled at the same speed of rotation with the long-stroke crankshaft (4) by means of a gear (16) secured to it. last and two intermediate gears (not shown) between the two aforementioned gears (14,16).

L'arbre de transmission (35) comprend du côté du palier (40) faisant face au palier applique (15), des cannelures droites (47) sur lesquelles vient s'emmancher le tube coulissant (17). Ce tube coulissant (17) comporte sur sa périphérie interne des cannelures (48) appariées aux cannelures droites (47), de manière que le tube coulissant (17) puisse coulisser axialement sur l'arbre de transmission (35).The drive shaft (35) comprises on the side of the bearing (40) facing the applied bearing (15) straight splines (47) on which the sliding tube (17) engages. This sliding tube (17) has on its inner periphery splines (48) matched to the straight splines (47), so that the sliding tube (17) can slide axially on the transmission shaft (35).

Le manchon (36) comporte sur sa périphérie interne des cannelures hélicoïdales (49) appariées aux cannelures hélicoïdales externes (52) du tube coulissant (17), de manière que ce dernier puisse coulisser hélicoïdalement dans le manchon (36) et permettre le décalage angulaire entre les dits deuxième et troisième éléments en même temps que le coulissement droit entre les premier et troisième éléments précités. Le manchon (36) est fixé solidairement en rotation avec l'arbre (17) lorsque le tube coulissant (17) n'est pas en translation axiale.The sleeve (36) has on its inner periphery helical splines (49) matched to the outer helical splines (52) of the sliding tube (17) so that the latter can slide helically in the sleeve (36) and allow angular displacement. between said second and third elements at the same time as the right sliding between the first and third elements mentioned above. The sleeve (36) is fixed integrally in rotation with the shaft (17) when the sliding tube (17) is not in axial translation.

La longueur du tube coulissant (17) est préétablie à l'intérieur du manchon (36) lorsque l'extrémité du dit tube coulissant (17) se situe à la limite d'arrêt définie par l'obstruction du palier (40). L'autre extrémité du tube coulissant (17) est dégagée à l'extérieur du manchon (36) au travers de l'engrenage (14) hors du bloc moteur (1) pour permettre, par des moyens appropriés, la fixation de la bague intérieure du roulement (50) à deux rangées à contact oblique. La dite bague intérieure du roulement (50) est rendue solidaire avec le mouvement de rotation du tube coulissant (17), tandis que la bague extérieure du roulement (50), sans mouvement de rotation, est solidarisée avec la pièce d'attache (18).The length of the sliding tube (17) is pre-established inside the sleeve (36) when the end of said sliding tube (17) is at the stop limit defined by the obstruction of the bearing (40). The other end of the sliding tube (17) is disengaged outside the sleeve (36) through the gear (14) out of the engine block (1) to allow, by appropriate means, the fixing of the ring Inner bearing (50) with two rows of oblique contact. Said inner ring of the bearing (50) is made integral with the rotational movement of the sliding tube (17), while the outer ring of the bearing (50), without rotational movement, is secured to the attachment piece (18). ).

Une mémoire de décision du programme des taux de compression agissant par un système de commande hydraulique permet le déplacement de la pièce d'attache (18) et du tube coulissant (17) pour modifier le calage entre les deux vilebrequins (4 et 5).A decision memory of the compression rate program acting by a hydraulic control system allows the displacement of the attachment piece (18) and the sliding tube (17) to modify the wedging between the two crankshafts (4 and 5).

Le début de course de la transmission à calage variable est agencé de telle sorte que le tube coulissant (17) soit à la position de butée de sortie prévue sur vérin (non représentée) correspond au minimum d'avance angulaire de la manivelle du vilebrequin à petite course (5) par rapport à la manivelle du vilebrequin à grande course (4).The start of travel of the variable pitch transmission is arranged so that the sliding tube (17) is at the output stop position provided on the cylinder (not shown) corresponds to the minimum angular advance of the crankshaft crankshaft. short stroke (5) relative to crankshaft crank with large stroke (4).

La fin de course de la transmission à calage variable est agencée de telle sorte que le tube coulissant (17) soit à la position de butée également prévu sur le vérin (non représentée) correspondant au maximum d'avance angulaire de la manivelle du vilebrequin à petite course (5) par rapport à la manivelle du vilebrequin à grande course (4).The end of travel of the variable pitch transmission is arranged in such a way that the sliding tube (17) is at the stop position also provided on the jack (no shown) corresponding to the maximum angular advance of the short-stroke crankshaft crank (5) relative to the long-stroke crankshaft crank (4).

La distribution est assurée au moins par un arbre à cames (non représenté) en prise à demi-vitesse avec le vilebrequin à grande course (4). Les soupapes d'admission et d'échappement dans la culasse (non représenté), mettant en communication périodique le groupe des deux cylindres (2,3) avec les conduites d'admission et d'échappement (non représenté) à des moments précis du cycle à quatre temps.The distribution is provided at least by a camshaft (not shown) engaged at half speed with the crankshaft large stroke (4). The intake and exhaust valves in the cylinder head (not shown), periodically communicating the group of two cylinders (2, 3) with the intake and exhaust lines (not shown) at specific times in the cylinder. four-stroke cycle.

Le rapport entre la cylindrée du cylindre (3) et la cylindrée du cylindre (2) se situe au moins entre 1/10 et 9/10 de préférence entre 1/5 et 3/5 permettant d'adapter le rapport volumétrique du moteur en fonction du taux de la pression de suralimentation.The ratio between the cylinder capacity of the cylinder (3) and the cylinder capacity of the cylinder (2) is at least between 1/10 and 9/10, preferably between 1/5 and 3/5, making it possible to adapt the volumetric ratio of the engine to depending on the rate of the boost pressure.

La transmission à calage variable (10) est dotée d'un palier applique (15) qui se fixe au carter cylindre (1), de manière que la transmission à calage variable (10) puisse constituer un ensemble séparé de l'arbre (13) du vilebrequin à manivelle à petite course (5). A cet effet, la transmission à calage variable (10) et le vilebrequin à manivelle à petite course (5) sont réalisés chacun avec leur arbre respectif (12,13). L'extrémité à cannelures externes de l'arbre (12) de la transmission à calage variable (10) est réalisée de manière à faire correspondre les cannelures internes situées dans le tourillon du palier (20) et dans l'arbre (13). L'accouplement entre les deux parties jointives est prévu par un glissement axial au moment de l'application du palier applique (15) dans un orifice prévu dans le carter cylindre (1). Le palier applique (15) est axé sur l'arbre (13) du vilebrequin à manivelle à petite course (5), de manière à permettre le centrage de l'arbre (12) dans le tourillon (20) et dans ledit arbre (13), ce dernier servant avantageusement de palier rigide à l'arbre (12) lors de l'application du palier applique (15) sur le carter cylindre (1); ce moyen permettant le démontage de la transmission à calage variable (10) hors du carter cylindre et hors du carter d'accouplement(1) sans devoir procéder au démontage du vilebrequin à manivelle à petite course (5).The variable-pitch transmission (10) is provided with an applied bearing (15) which attaches to the cylinder block (1), so that the variable-pitch transmission (10) can constitute a separate assembly of the shaft (13). crankshaft crankshaft with short stroke (5). For this purpose, the variable-pitch transmission (10) and the short-stroke crankshaft (5) are each made with their respective shaft (12, 13). The externally splined end of the shaft (12) of the variable pitch transmission (10) is made to match the internal splines in the bearing journal (20) and the shaft (13). The coupling between the two contiguous parts is provided by axial sliding at the time of application of the applied bearing (15) in an orifice provided in the cylinder block (1). The bearing (15) is centered on the shaft (13) of the crankshaft crankshaft with short stroke (5), so as to allow the centering of the shaft (12) in the trunnion (20) and in said shaft ( 13), the latter advantageously acting as a rigid bearing on the shaft (12) during the application of the bearing (15) to the cylinder block (1); this means allowing disassembly of the variable-pitch transmission (10) out of the cylinder block and out of the coupling housing (1) without having to disassemble the short-stroke crankshaft crankshaft (5).

L'extrémité jointive mâle de l'arbre (12) de la transmission à calage variable (10) et l'extrémité jointive femelle façonnée dans l'arbre (13) au niveau du tourillon (20) du vilebrequin à manivelle à petite course (5) apportent l'avantage de diminuer l'encombrement de l'accouplement de la transmission à calage variable dans le carter moteur (1),The contiguous male end of the shaft (12) of the variable pitch transmission (10) and the female contiguous end formed in the shaft (13) at the small crank crankpin (20) of the crankshaft ( 5) provide the advantage of reducing the size of the coupling of the variable-pitch transmission in the crankcase (1),

Suivant une forme préférée de l'invention le moteur comprend des moyens pour renforcer la rigidité axiale entre le vilebrequin à petite course (5) et la transmission à calage variable (10), les arbres (12 et 13) sont fusionnés en un seul arbre de manière à permettre que l'arbre de transmission (35) comprenant le disque (40) et les cannelures droites (47) s'associent au vilebrequin à petite course (5). La distance de séparation entre les supports de fixation du disque (40) et le palier (15) est réalisée à la même distance de séparation entre la fixation du carter cylindre (1) du palier (15) et le support de fixation du disque (40) lorsque l'arbre du vilebrequin à petite course est inséré dans les paliers (20) du carter cylindre (1). Il découle de cet assemblage une fixation axiale de l'arbre du vilebrequin à petite course (5) par le roulement (39) et une fixation radiale du manchon (36) par les paliers du vilebrequin à petite course (5).According to a preferred form of the invention, the engine comprises means for reinforcing the axial rigidity between the short-stroke crankshaft (5) and the variable-pitch transmission (10), the shafts (12 and 13) being fused into a single shaft so as to allow the transmission shaft (35) comprising the disk (40) and the straight splines (47) to be associated with the short-stroke crankshaft (5). The separation distance between the disk mounting brackets (40) and the bearing (15) is made at the same separation distance between the cylinder block housing (1) of the bearing (15) and the disk mounting bracket ( 40) when the short-stroke crank shaft is inserted into the bearings (20) of the cylinder block (1). It follows from this assembly an axial attachment of the short-stroke crank shaft (5) by the bearing (39) and a radial attachment of the sleeve (36) by the bearings of the small stroke crankshaft (5).

Suivant une forme préférée de l'invention, dans le carter d'accouplement (31) il est prévu deux engrenages d'accouplement intermédiaires (non représentés) entre les engrenages (14) du vilebrequin à petite course (5) et un deuxième engrenage (16) fixé à l'entretoise (19) solidaire du volant du moteur (26) et du vilebrequin à grande course (4) de façon à obtenir des sens de rotation inverses à même vitesse des deux vilebrequins (4,5).According to a preferred form of the invention, in the coupling housing (31) there are provided two intermediate coupling gears (not shown) between the gears (14) of the short-stroke crankshaft (5) and a second gear ( 16) fixed to the spacer (19) integral with the flywheel of the motor (26) and the crankshaft with a large stroke (4) so as to obtain opposite directions of rotation at the same speed of the two crankshafts (4,5).

La transmission à calage variable (10) comprend un tube coulissant (17) du côté faisant face à l'engrenage (14), la partie externe du tube coulissant comporte sur sa périphérie externe des cannelures hélicoïdales appariées aux cannelures hélicoïdales (non représenté) de l'engrenage (14). Le tube coulissant (17) comprend également des cannelures droites internes (non représentées) appariées aux cannelures externes solidaires de l'arbre (12) (non représentées) sur lesquelles vient s'emmancher le tube coulissant (17), de manière que le dit tube (17) en coulissant puisse réaliser le décalage angulaire entre l'arbre de transmission (12) et l'engrenage (14).The variable-pitch transmission (10) comprises a sliding tube (17) on the gear-facing side (14), the outer portion of the sliding tube has on its outer periphery helical splines paired with the helical splines (not shown) of the gear (14). The sliding tube (17) also comprises internal straight splines (not shown) matched to the external splines integral with the shaft (12) (not shown) on which the sliding tube (17) is engaged so that said sliding tube (17) can effect the angular offset between the transmission shaft (12) and the gear (14).

Une mémoire de décision du programme des taux de compression agissant sur le vérin de commande (non représenté) fixé sur la pièce d'attache (18) et le tube coulissant (17) afin de modifier le calage angulaire entre les deux arbres des deux vilebrequins (4,5).A decision memory of the compression ratio program acting on the control cylinder (not shown) attached to the attachment piece (18) and the sliding tube (17) in order to modify the angular setting between the two shafts of the two crankshafts (4,5).

Le début et la fin de course de la transmission à calage variable peuvent être agencés de telle sorte que le tube coulissant (17) ne puisse coulisser au-delà des positions de butées qui sont prévues sur le vérin de commande (non représenté). Le dit vérin de commande étant fixé sur un support prévu sur le couvercle de fermeture (23) du carter d'accouplement (31) situé à côté du volant moteur (26). Le démontage du couvercle de fermeture (23) permettant de rendre accessible l'entretien ou le démontage de la transmission à calage variable (10) sans le démontage du carter d'accouplement (31). Suivant l'invention et suivant cette disposition, l'axe du dit vérin de commande est avantageusement fixé à la pièce d'attache (18) de la commande de la transmission à calage variable (10).The start and end of travel of the variable pitch transmission can be arranged in such a way that the sliding tube (17) can not slide beyond the stop positions which are provided on the control jack (not shown). Said control cylinder being fixed on a support provided on the closing cover (23) of the coupling housing (31) located next to the flywheel (26). Disassembly of the closure cover (23) making it possible to make maintenance or dismantling of the variable-pitch transmission (10) accessible without disassembly of the coupling housing (31). According to the invention and according to this arrangement, the axis of said control jack is advantageously fixed to the attachment piece (18) of the control of the variable pitch transmission (10).

Selon une forme préférée de l'invention, les rapports volumétriques minimal et maximal sélectionnés pour le type de moteur à concevoir, sont réalisés en fonction des dimensions des différents éléments du moteur, à savoir d'une part, le rapport entre la cylindrée des deux cylindres groupés (2 et 3) et d'autre part, le rapport formé par le volume total des deux cylindrées de ces cylindres (2,3) avec le volume formé par l'espace mort (24), ces derniers rapports sont agencés de telle manière, que l'avance angulaire maximale de la manivelle du vilebrequin à petite course (5) par rapport à la manivelle du vilebrequin à grande course (4), définie par la position de fin de course de la transmission à calage variable, fasse correspondre, en phase fin de compression (point mort haut du piston 6), le positionnement du piston (8) avec l'espace additionnel nécessaire à l'espace mort (24) pour définir le dit rapport volumétrique minimal du moteur avec un angle d'au moins 90° entre la bielle (9) et la manivelle du vilebrequin à petite course (5).According to a preferred form of the invention, the minimum and maximum volumetric ratios selected for the type of engine to be designed, are made according to the dimensions of the various elements of the engine, namely on the one hand, the ratio between the cubic capacity of the two grouped cylinders (2 and 3) and secondly, the ratio formed by the total volume of the two displacements of these cylinders (2, 3) with the volume formed by the dead space (24), these latter ratios are arranged from in such a way that the maximum angular advance of the crankshaft of the short-stroke crankshaft (5) relative to the crankshaft of the long-stroke crankshaft (4), defined by the end-of-travel position of the variable-pitch transmission, correspond, in the end phase of compression (top dead center of the piston 6), the positioning of the piston (8) with the additional space necessary for the dead space (24) to define the said minimum volumetric ratio of the engine with an angle of at least 90 ° between the connecting rod (9) and crankshaft crankshaft short stroke (5).

Les dispositions du réglage angulaire précitées entre les deux vilebrequins dans la position de fin de course de la transmission à calage variable, en relation avec les dimensions appropriées entre les différents éléments du moteur, permettent à ce dernier de fonctionner:

  • en phase de détente, avec les gaz de combustion sur le piston (8) associés au moins à partir du couple maximum instantané sur la manivelle du vilebrequin à petite course (5);
  • en phase de détente, en limitant la remontée du piston (non représenté) antérieurement à l'ouverture de la soupape d'échappement (non représentée) source de contre-pressions des gaz de combustion sur le dit piston (8);
  • en phase fin d'admission, en limitant la remontée du piston (non représenté) source de diminution du volume de remplissage dans le cylindre (3).
The above-mentioned angular adjustment arrangements between the two crankshafts in the end-of-travel position of the variable-pitch transmission, in relation to the appropriate dimensions between the different elements of the engine, allow the latter to operate:
  • in the expansion phase, with the combustion gases on the piston (8) associated at least from the instantaneous maximum torque on the crank of the short-stroke crankshaft (5);
  • in the expansion phase, limiting the rise of the piston (not shown) prior to the opening of the exhaust valve (not shown) source of counterpressures of the combustion gases on said piston (8);
  • in the end phase of admission, limiting the rise of the piston (not shown) source of decrease of the filling volume in the cylinder (3).

Ces fonctionnements ont pour avantage d'assurer le maintien du rendement optimal du moteur au régime de la pleine charge.These operations have the advantage of ensuring the maintenance of optimum performance of the engine at the full load regime.

Le rapport volumétrique maximal sélectionné est réalisé sur la même base de données que les valeurs dimensionnelles définies pour le rapport volumétrique minimal, de telle manière, que l'avance angulaire minimale de la manivelle du vilebrequin à petite course (5) par rapport à la manivelle du vilebrequin à grande course (4), définie par la position de début de course de la transmission à calage variable, fasse correspondre en phase fin de compression (point mort haut du piston (6), le positionnement du piston (8) avec l'espace additionnel nécessaire à l'espace mort (24) pour définir le rapport volumétrique maximal du moteur avec la bielle (9) de la manivelle du vilebrequin à petite course (5) écartée de son point mort haut, de manière que la dite bielle (9) forme un angle avec la manivelle du vilebrequin à petite course (5).The selected maximum volumetric ratio is made on the same data base as the dimensional values defined for the minimum volumetric ratio, such that the minimum angular advance of the crankshaft of the short-stroke crankshaft (5) relative to the crank of the crankshaft with a large stroke (4), defined by the start position of the variable-pitched transmission, correspond in the fine compression phase (top dead center of the piston (6), the positioning of the piston (8) with the additional space required for the dead space (24) to define the maximum volumetric ratio of the engine with the connecting rod (9) of the small crankshaft crank (5) spaced from its top dead center, so that said connecting rod (9) forms an angle with the crankshaft of the short-stroke crankshaft (5).

Les dispositions du réglage angulaire précitées entre les deux vilebrequins (4,5) dans la position de début de course de la transmission à calage variable en relation avec les dimensions appropriées entre les différents éléments du moteur, permettent à ce dernier de fonctionner:

  • en phase fin de compression, en assurant un mouvement de translation plus important sur le piston (8) par degré unitaire de décalage angulaire entre les manivelles des deux vilebrequins (4,5).
The above-mentioned angular adjustment arrangements between the two crankshafts (4,5) in the starting position of the variable timing transmission in relation to the appropriate dimensions between the various elements of the engine, allow the latter to operate:
  • in the fine compression phase, by providing a greater translational movement on the piston (8) by unit angular offset degree between the cranks of the two crankshafts (4,5).

Ce fonctionnement a pour avantage d'accélérer le processus de modifications du rapport volumétrique du moteur à faible charge.This operation has the advantage of accelerating the process of changes in the volumetric ratio of the engine at low load.

Nature des symboles adoptés:

  • P = rapport volumétrique.
  • V1 = cylindrée du plus grand des deux cylindres groupés.
  • V2 = cylindrée du plus petit des deux cylindres groupés.
  • V1/V2 = rapport volumétrique entre les deux cylindrées des deux cylindres groupés.
  • α = avance angulaire de la manivelle du vilebrequin à petite course.
  • Ve = volume de l'espace mort des deux cylindres groupés nécessaire pour le transfert des gaz sans laminage excessif.
  • (α minimum): avance angulaire de la manivelle du vilebrequin à petite course, en début de course de la transmission à calage variable.
  • (α maximum) : avance angulaire de la manivelle du vilebrequin à petite course,
en fin de course de la transmission à calage variable.Nature of symbols adopted:
  • P = volumetric ratio.
  • V1 = displacement of the largest of the two grouped cylinders.
  • V2 = cubic capacity of the smaller of the two grouped cylinders.
  • V1 / V2 = volumetric ratio between the two displacements of the two grouped cylinders.
  • α = angular advance of crankshaft crank with small stroke.
  • Ve = volume of the dead space of the two grouped cylinders necessary for the transfer of gases without excessive rolling.
  • (α minimum): angular advance of crankshaft crank with short stroke, at the start of the variable-pitch transmission stroke.
  • (α maximum): angular advance of crankshaft crank with small stroke,
at the end of the race of the variable timing transmission.

Va (α minimum): volume additionnel s'ajoutant au volume de l'espace mort en début de course de la transmission à calage variable défini par l'angle minimum de l'avance angulaire de la manivelle du vilebrequin à petite course.Va (α minimum): additional volume in addition to the volume of the dead space at the beginning of the variable-pitch transmission defined by the minimum angle of the angular advance of the crankshaft of the small-stroke crankshaft.

Va (α maximum): volume additionnel s'ajoutant au volume de l'espace mort, en fin de course de la transmission à calage variable, défini par l'angle maximum de l'avance angulaire de la manivelle du vilebrequin à petite course lorsque la manivelle du vilebrequin à grande course se situe au point mort haut, en phase fin de compression.Va (maximum α): additional volume added to the volume of the dead space, at the end of the variable-timing transmission, defined by the maximum angle of the angular advance of the crankshaft crank with short stroke when crankshaft crankshaft with high stroke is at the top dead center, in the late phase of compression.

Vr (α minimum): volume de refoulement d'air en début de course de la transmission à calage variable, défini par l'angle minimum de l'avance angulaire de la manivelle du vilebrequin à petite course lorsque la manivelle du vilebrequin à grande course se situe au point mort bas, en phase fin admission.Vr (α minimum): air flow volume at the start of the variable-timing transmission stroke, defined by the minimum angular advance angle of the short-stroke crankshaft crank when the large crankshaft crankshaft is at the bottom dead center, in the late phase admission.

Vr (α maximum): volume de refoulement d'air en fin de course de la transmission à calage variable, défini par l'angle maximum de l'avance angulaire de la manivelle du vilebrequin à petite course lorsque la manivelle du vilebrequin à grande course se situe au point mort bas, en phase fin admission.Vr (α maximum): end-of-stroke air discharge volume of the variable-pitch transmission, defined by the maximum angle of angular advance of the crankshaft crank with short stroke when crankshaft crankshaft with large stroke is at the bottom dead center, in the late phase admission.

Caractéristiques et formules des rapports volumétriques du moteur à chambre de combustion à volume variable. V ⁢ 1 + V ⁢ 2 × nombre de groupes de 2 cylindres = cylindrée du moteur .

Figure imgb0002
V ⁢ 1 + V ⁢ 2 - Vr α × nomb . de grp de 2 cyl . = cylindrée du moteur définie par le calage de la transmission à calage variable .
Figure imgb0003
 V ⁢ 1 + V ⁢ 2 - Vr α + ve ve + Va α = P . théorique
Figure imgb0004
 Features and formulas of volumetric ratios of variable volume combustion chamber engine. V ⁢ 1 + V ⁢ 2 × number of groups of 2 cylinder = engine displacement .
Figure imgb0002
 V ⁢ 1 + V ⁢ 2 - Vr α × Num . grp 2 cyl . = Engine displacement defined by the timing of the variable timing transmission .
Figure imgb0003
 V ⁢ 1 + V ⁢ 2 - Vr α + ve ve + Goes α = P . theoretical
Figure imgb0004

Caractéristique volumétrique théorique du moteur avec définition des rapports volumétriques agencés par le calage de la transmission à calage variable. V ⁢ 1 + V ⁢ 2 - Vr α . minimum + ve ve + Va α . minimum = P maximum

Figure imgb0005
Theoretical volumetric characteristic of the engine with definition of volumetric ratios arranged by the wedging of the variable-pitch transmission. V ⁢ 1 + V ⁢ 2 - Vr α . minimum + ve ve + Goes α . minimum = Maximum P
Figure imgb0005

Définition du rapport volumétrique maximum en début de course de la transmission à calage variable. En pratique, on peut considérer que Vr (α minimum) ne doit pas se déduire de V2 car trop négligeable. V ⁢ 1 + V ⁢ 2 - Vr α maximum + ve ve + Va α . maximum = P minimum

Figure imgb0006
Definition of the maximum volumetric ratio at the start of the stroke of the variable timing transmission. In practice, we can consider that Vr (α minimum) should not be deduced from V2 because too negligible. V ⁢ 1 + V ⁢ 2 - Vr maximum α + ve ve + Goes α . maximum = P minimum
Figure imgb0006

Définition du rapport volumétrique minimum en fin de course de la transmission à calage variable. En pratique, on peut considérer que Vr (α maximum) ne doit pas se déduire de V2 car la masse admise en V1 et V2 est tributaire de l'étalonnage mémorisé à la pression de suralimentation maximale.Definition of the minimum volumetric ratio at the end of the stroke of the variable timing transmission. In practice, it can be considered that Vr (maximum α) should not be deduced from V2 because the mass allowed in V1 and V2 is dependent on the calibration stored at the maximum boost pressure.

On peut admettre une formule simplifiée du rapport volumétrique suivant que Va (α) se situe à n'importe quelle position angulaire entre le début et la fin de course de la transmission à calage variable soit: V ⁢ 1 + V ⁢ 2 + ve ve + Va α = P

Figure imgb0007
We can admit a simplified formula of the volumetric ratio according to which Va (α) is located at any angular position between the beginning and the end of the race of the variable-pitched transmission: V ⁢ 1 + V ⁢ 2 + ve ve + Goes α = P
Figure imgb0007

Conformément à l'invention, le rapport volumétrique minimal sélectionné peut être réalisé entre deux limites de fin de course de la transmission à calage variable. La première limite est réalisée avec une avance angulaire maximale de la manivelle du vilebrequin à petite course (5) par rapport à la manivelle du vilebrequin à grande course (4) de façon à déterminer en fin de compression (point mort haut du piston 6) le positionnement du piston (8) en rapport avec l'espace additionnel nécessaire à l'espace mort (24) pour définir le dit rapport volumétrique minimal avec un angle d'au moins 90° entre la bielle et la manivelle du vilebrequin à petite course (5), la deuxième limite est réalisée avec une moindre avance angulaire de la manivelle du vilebrequin à petite course (5) par rapport à la manivelle du vilebrequin à grande course (4) et ce proportionnellement à la diminution du rapport entre les deux cylindrées des deux cylindres (2,3) jusqu'à la limite de tolérance engendrée par l'espace de travail des deux vilebrequins (4,5) défini par les positions parallèles et rapprochées des deux cylindres groupés (2,3) suivant la formule du rapport volumétrique minimal ci-après: V ⁢ 1 + V ⁢ 2 - Vr α . maximum + ve ve + Va α . maximum = P minimum

Figure imgb0008
According to the invention, the selected minimum volumetric ratio can be achieved between two end-of-travel limits of the variable-pitch transmission. The first limit is achieved with a maximum angular advance of the short-stroke crankshaft crank (5) relative to the crankshaft of the large-stroke crankshaft (4) so as to determine the end of compression (top dead center of the piston 6) the positioning of the piston (8) in relation to the additional space required for the dead space (24) to define the said minimum volumetric ratio with an angle of at least 90 ° between the connecting rod and the crank of the small-stroke crankshaft (5), the second limit is achieved with a smaller angular advance of the short-stroke crankshaft crank (5) relative to the crankshaft of the large-stroke crankshaft (4) and this proportionally to the decrease in the ratio between the two displacements of the two cylinders (2, 3) up to the limit of tolerance generated by the working space of the two crankshafts (4, 5) defined by the parallel and close positions of the two grouped cylinders (2, 3) according to the has the minimum volumetric ratio formula below: V ⁢ 1 + V ⁢ 2 - Vr α . maximum + ve ve + Goes α . maximum = P minimum
Figure imgb0008

On peut calculer un plus grand rapport volumétrique entre les deux cylindrées des deux cylindres groupés afin de diminuer les contraintes d'efforts sur la transmission à calage variable sur les moteurs à plus petite cylindrée, à l'inverse on peut calculer un plus petit rapport volumétrique entre les deux cylindrées des deux cylindres groupés (2,3) afin d'augmenter la vitesse des moteurs à plus grande cylindrée.It is possible to calculate a greater volumetric ratio between the two displacements of the two cylinders grouped in order to reduce the stress of forces on the variable timing transmission on the engines with smaller displacement, conversely we can calculate a smaller volumetric ratio. between the two displacements of the two grouped cylinders (2,3) in order to increase the speed of the engines with larger displacement.

En pratique, on peut considérer que Vr (α maximum) ne doit pas se déduire de V2; car la masse admise en V1 et V2 est tributaire de l'étalonnage mémorisé entre le rapport volumétrique et la pression de suralimentation.In practice, we can consider that Vr (α maximum) should not be deduced from V2; because the mass admitted in V1 and V2 is dependent on the calibration memorized between the volumetric ratio and the boost pressure.

Le rapport volumétrique maximal sélectionné est réalisé sur la base des données des valeurs dimensionnelles définies pour le rapport volumétrique minimal, de telle manière qu'en début de course de la transmission à calage variable, l'avance angulaire minimale de la manivelle du vilebrequin à petite course (5) par rapport à la manivelle du vilebrequin à grande course (4) détermine, en fin de compression (point mort haut du piston 6), le positionnement du piston (8) en rapport avec l'espace additionnel nécessaire à l'espace mort (24) pour définir un rapport volumétrique maximal avec la bielle (9) de la manivelle du vilebrequin à petite course (5) écartée de son point mort haut, afin que la dite bielle (9) forme un angle avec la manivelle du vilebrequin à petite course (5). On peut donc définir le rapport volumétrique maximal suivant la formule: V ⁢ 1 + V ⁢ 2 - Vr α . minimum + ve ve + Va α . minimum = P maximum

Figure imgb0009
The selected maximum volumetric ratio is made on the basis of the data of the dimensional values defined for the minimum volumetric ratio, such that at the beginning of the stroke of the variable pitch transmission, the minimum angular advance of the crankshaft crankshaft to small stroke (5) relative to the crankshaft of the large-stroke crankshaft (4) determines, at the end of compression (top dead center of the piston 6), the positioning of the piston (8) in relation to the additional space necessary for the dead space (24) to define a maximum volumetric ratio with the connecting rod (9) of the short crankshaft crank (5) spaced from its top dead center, so that said rod (9) forms an angle with the crank of the crankshaft with short stroke (5). We can therefore define the maximum volumetric ratio according to the formula: V ⁢ 1 + V ⁢ 2 - Vr α . minimum + ve ve + Goes α . minimum = Maximum P
Figure imgb0009

En pratique, on peut considérer que Vr (αminimum) ne doit pas se déduire de V2, car la masse d'air admise en V1 et V2 est tributaire de l'étalonnage mémorisé entre le rapport volumétrique et la dépression atmosphérique dans la pipe d'admission.In practice, it can be considered that Vr (αminimum) should not be deduced from V2, because the air mass admitted at V1 and V2 is dependent on the calibration memorized between the volumetric ratio and the atmospheric depression in the pipe. admission.

Les diagrammes sont établis à partir de la formule ci-après:

  • a = point mort haut du petit cylindre (3)
  • b = sommet du petit piston (8)
  • s = surface du petit piston (8)
  • l = longueur de la petite bielle (9)
  • r = longueur du petit vilebrequin (5)
  • A = point mort haut du grand cylindre (2)
  • B = sommet du grand piston (6)
  • S = surface du grand piston (6)
  • L = longueur de la grande bielle (7)
  • R = longueur du grand vilebrequin (4)
  • Vm = volume de l'espace mort (24)
  • A = rotation angulaire (0° au point mort haut) (sens anti-trigonométrique)
  • A = avance angulaire du petit vilebrequin (5) par rapport au grand vilebrequin (4)
The diagrams are based on the formula below:
  • a = top dead center of the small cylinder (3)
  • b = top of the small piston (8)
  • s = surface of the small piston (8)
  • l = length of the small connecting rod (9)
  • r = length of the small crankshaft (5)
  • A = top dead center of the large cylinder (2)
  • B = top of the big piston (6)
  • S = large piston surface (6)
  • L = length of the big connecting rod (7)
  • R = length of the large crankshaft (4)
  • Vm = volume of the dead space (24)
  • A = angular rotation (0 ° at top dead center) (anti-trigonometric direction)
  • A = angular advance of the small crankshaft (5) relative to the large crankshaft (4)

Exemple pour rendre le moteur fonctionnel et performant suivant l'une des nombreuses applications V = ab × s + AB × S + Vm = s ⁢ r ⁢ 1 - cos α + ϕ + 1 ⁢ 1 - 1 - r / 1 2 sin 2 α + ϕ + S ⁢ R ⁢ 1 - cos α + L ⁢ 1 - 1 - R / L 2 sin 2 α + Vm

Figure imgb0010
Example to make the engine functional and efficient according to one of the many applications V = ab × s + AB × S + vm = s ⁢ r ⁢ 1 - cos α + φ + 1 ⁢ 1 - 1 - r / 1 2 sin 2 α + φ + S ⁢ R ⁢ 1 - cos α + The ⁢ 1 - 1 - R / The 2 sin 2 α + vm
Figure imgb0010

La formule ci-dessus enregistrée dans une feuille de calcul de l'ordinateur permet de générer les valeurs dimensionnelles entre les différents éléments du moteur, c'est à dire, les rapports volumétriques entre les deux cylindrées des deux cylindres groupés (2,3) et le rapport formé par le volume total des deux cylindrées de ces cylindres (2,3) avec le volume formé par l'espace mort (24), le calcul est établi de manière que les spécifications qui ont été prévues pour les rapports volumétriques maxima et minima du moteur puissent coïncider avec les degrés correspondants des avances angulaires minima et maxima de la manivelle du vilebrequin à petite course par rapport à la manivelle du vilebrequin à grande course respectivement du début et de fin de course de la transmission à calage variable.The above formula recorded in a spreadsheet of the computer makes it possible to generate the dimensional values between the various elements of the engine, that is to say, the volumetric ratios between the two displacements of the two grouped cylinders (2,3). and the ratio formed by the total volume of the two displacements of these cylinders (2, 3) with the volume formed by the dead space (24), the calculation is established in such a way that the specifications which have been provided for the maximum volumetric ratios and engine minima may coincide with the corresponding degrees of the minimum and maximum crank angle of the small crankshaft crank relative to the crankshaft of the large stroke crank respectively of the start and end of stroke of the variable pitch transmission.

Avantages pour le moteur à quatre temps à allumage par compression.

  • augmentation du rendement volumétrique;
  • augmentation de la puissance massique ;
  • diminution des pertes par frottements mécaniques;
  • adaptation du moteur à l'indice de cétane ;
  • définition avec précision d'une température de fin de compression idéale pour l'auto-inflammation du carburant dans toutes les circonstances envisageables (du démarrage à froid jusqu'aux hautes pressions de suralimentation);
  • Meilleure performance du moteur en altitude ;
  • minimisation des rejets d'oxyde d'azote et d'hydrocarbures imbrûlés.
Advantages for the four-stroke compression ignition engine.
  • increase in volumetric efficiency;
  • increase in the mass power;
  • reduction of mechanical friction losses;
  • adaptation of the engine to the cetane number;
  • accurately defining an ideal compression end temperature for self-ignition of the fuel in all conceivable circumstances (from cold start to high boost pressures);
  • Best performance of the engine at altitude;
  • minimizing releases of nitrogen oxide and unburned hydrocarbons.

Avantages pour le moteur à quatre temps à allumage commandé.

  • augmentation du rendement volumétrique;
  • augmentation de la puissance massique;
  • diminution des pertes par frottements mécaniques et par pompages;
  • augmentation du rendement du moteur en charges partielles, du fait de l'augmentation du taux de compression proportionnellement à la dépression dans la pipe d'admission.
    (fermeture du papillon des gaz)
  • adaptation du moteur à l'indice d'octane;
  • meilleures performances du moteur en altitude;
  • meilleure homogénéité du mélange ;
  • minimisation des rejets de monoxyde de carbone, d'oxydes d'azote et d'hydrocarbures imbrûlés.
Advantages for the four-stroke spark ignition engine.
  • increase in volumetric efficiency;
  • increase in the mass power;
  • decrease in losses due to mechanical friction and pumping;
  • increased efficiency of the engine in partial loads, due to the increase of the compression ratio proportionally to the depression in the intake pipe.
    (closing the throttle valve)
  • adaptation of the engine to the octane number;
  • better performance of the engine at altitude;
  • better homogeneity of the mixture;
  • minimizing releases of carbon monoxide, oxides of nitrogen and unburned hydrocarbons.

Avantages et conditions d'utilisation du moteur à quatre temps à allumage par compression à haut taux de pression de suralimentation sur les véhicules tracteurs routiers.Advantages and conditions of use of four-stroke compression-ignition engine with high boost pressure ratio in road tractor vehicles.

La réduction de la cylindrée de chaque cylindre du moteur suivant le critère de la vitesse moyenne des pistons, permet une augmentation du régime moteur et une diminution cohérente des basses fréquences. Il sera prévu une plus grande démultiplication sur l'ensemble boîte de vitesses-arbre de transmission jusqu'à la deuxième réduction du pont moteur. Comme le frottement mécanique est proportionnel à la cylindrée et peu sensible à la charge, le rendement s'en trouve amélioré. Le frein moteur pourra être maintenu en envisageant une augmentation de la puissance du moteur à l'appui d'un limiteur de vitesse sur le véhicule.The reduction of the displacement of each cylinder of the engine according to the criterion of the average speed of the pistons, allows an increase of the engine speed and a coherent decrease of the low frequencies. It will be expected a greater reduction on the gearbox-shaft assembly until the second reduction of the engine bridge. As the mechanical friction is proportional to the cubic capacity and not very sensitive to the load, the efficiency is improved. The engine brake can be maintained by considering an increase in engine power in support of a speed limiter on the vehicle.

Dans la forme de la figure 6, la rigidité radiale entre le vilebrequin à petite course (5) et la transmission à calage variable (10) est renforcée.
Les arbres (12,13) sont fusionnés en un arbre unique de manière que l'arbre de transmission (35) portant le disque (40) soit associé au vilebrequin à petite course (5). Lorsque le vilebrequin à petite course est monté dans les paliers du carter cylindre, le manchon (36) équipé de ses pièces mécaniques (15,36,39,41,43,45,51) est fixé sur le disque (40) de l'arbre de transmission (35), en même temps que la fixation du palier (15) à travers l'orifice prévu dans le carter cylindre (1). Il découle d'un tel montage que l'arbre du vilebrequin à petite course est fixé axialement par le roulement (39), tandis que le manchon (36) est maintenu radialement par l'ensemble des paliers du vilebrequin à petite course par rapport au roulement (39).In the form of the figure 6 the radial stiffness between the short stroke crankshaft (5) and the variable pitch transmission (10) is increased.
The shafts (12, 13) are merged into a single shaft so that the drive shaft (35) carrying the disc (40) is associated with the short stroke crankshaft (5). When the small-stroke crankshaft is mounted in the bearings of the crankcase, the sleeve (36) equipped with its mechanical parts (15,36,39,41,43,45,51) is fixed on the disc (40) of the crankcase. transmission shaft (35), at the same time as the fixing of the bearing (15) through the orifice provided in the cylinder block (1). It follows from such an assembly that the short-stroke crankshaft shaft is fixed axially by the bearing (39), while the sleeve (36) is held radially by all the bearings of the crankshaft with small stroke relative to the bearing (39).

En ce que les multiples parois d'enfermement du liquide de refroidissement entre les deux cylindres groupés en forme de V inversé se terminent par une simple paroi au niveau de la jonction des points morts hauts de ces dits cylindres, la dite paroi étant mise à profit pour être élargie en forme de canal sensiblement rectangulaire jusqu'au plan de culasse. Le passage des gaz entre les deux cylindres groupés par le dit canal permet aussi de concrétiser une chambre de combustion commune à ces dits cylindres.In that the multiple enclosing walls of the coolant between the two inverted V-shaped cylinders terminate in a single wall at the junction of the high dead points of said cylinders, said wall being taken advantage of to be enlarged into a substantially rectangular channel shape up to the bolt plane. The passage of gases between the two cylinders grouped by the said channel also makes it possible to concretize a combustion chamber common to these said cylinders.

Dans des formes de réalisation préférées et représentées, les canaux (32) sont situés uniquement dans le corps du carter cylindre et partiellement dans le joint de culasse ou dans l'épaisseur dudit joint de culasse.In preferred and illustrated embodiments, the channels (32) are located only in the cylinder block body and partially in the cylinder head gasket or in the thickness of said cylinder head gasket.

Claims (18)

  1. A four-stroke internal combustion engine having an intake phase, a compression phase, an expansion phase and an exhaust phase, said engine operating by self-combustion or by controlled ignition, including:
    - a cylinder housing component (1) having a first series of cylinders (2), each having an axis and a diameter, and a second series of cylinders (3),each having an axis and diameter, the cylinders (2) of the first series having a larger displacement and diameter than the displacement and the diameter of the cylinders (3) of the second series (3),
    - pistons (6, 8), each piston being adapted to be driven by an alternative movement in a cylinder and being associated with a connecting rod,
    - two crankshafts with rotational axes parallel to one another, a first crankshaft (4) having a crank with a large stroke, whilst the second crankshaft (5) has a crank with a small stroke, less than the long stroke of the crank of the first crankshaft, the said crankshafts (4, 5) being adapted to be coupled at the same rotational speed, by means of a gear train (14, 16) and a variably timed transmission (10);
    in which each piston, being associated with a connecting rod (7, 9), is operated by a crank of a crankshaft, the short-stroke handle of the second crankshaft (5) operating the rod (9) of the piston (8) moving within the small cylinder (3), whilst the large-stroke crank of the first crankshaft (4) operates the lever (7) of the piston (6) moving within the large cylinder (2), in which the first series of cylinders (2) is laid out above the first crankshaft (4), whilst the second series of cylinders (3) is laid out above the second crankshaft (5),
    in which each cylinder (2) of the first series communicates with at least one cylinder (3) of the second series via a clearance space, in such a way as to form a pair of two cylinders (2, 3) communicating with one another to allow the gases to pass from one cylinder to the other, independently of the position of the pistons (6, 8) moving within the said cylinders (2, 3),
    characterised in that the cylinder housing component displays a face along which the cylinders are open, advantageously along the face of the cylinder head seal plane, channels being formed in the said face to form distinct passages for each pair of cylinders, a channel from one group extending between a cylinder from the first series and a cylinder from the second series, advantageously with a corresponding additional recess in the cylinder head gasket, the said channel having an average width determined in the cylinder head gasket plane of between 0.5 and 0.8 times the mean of the diameter of the cylinders connected by the channel in question.
  2. Engine as claim 1, in which, for each pair of cylinders connected to one another by a channel, the axis of a cylinder from the first series of the pair in question forms a first plane with a straight line parallel to the rotational axis of a crankshaft, whilst the axis of the cylinder from the second series of the pair in question forms a second plane with a straight line parallel to the rotational axis of a crankshaft, distinguished by the fact that the said planes define between themselves an angle lying between 1° and 60°, advantageously between 10° and 50°, preferably between 15° and 45°. The axes of the cylinders of a group intersect roughly in a point.
  3. Engine as any of the preceding claims, characterised in that the volume of the channel located between two cylinders of a pair lies between 1% and 25% of the total clearance volume of the pair in question, the said total clearance volume being defined by the total free volume of the pair with the two pistons at top dead centre.
  4. Engine following any of the preceding claims, characterised in that it includes a camshaft in mesh, at half speed, with the first crankshaft (4), so as to connect periodically groups of two cylinders (2,3) with intake and exhaust pipes via intake and exhaust valves, at definite moments of the four-stroke cycle,
  5. Engine as any of the preceding claims, characterised in that it includes a layout for the variably timed transmission (10), the said layout being adapted to receive, at least in part, a device for controlling the phase angle difference between the first and second lines of crankshafts.
  6. Engine as claim 5, in which the first and second crankshafts are associated, respectively, with a first driving wheel and a second driving wheel, and in which an engine flywheel is mounted on the long-stroke crankshaft (4), whilst the variably timed transmission (10) is mounted on the shaft of the short-stroke crankshaft (5) characterised in that a means of transmission extends between the said wheels, and in that the shafts of the two crankshafts (4, 5) are adapted in such a way that the variably timed transmission (10) is positioned next to the engine flywheel (26).
  7. Engine as any of the preceding claims, characterised in that it contains a variably timed transmission (10) comprising an assembly separated from the shaft (13) of the short-stroke crankshaft (5), in that the variably timed transmission (10) is fitted with a bearing plate (15) which is fixed by centring in an orifice provided for in the cylinder housing (1), and in that the variably timed transmission contains a shaft (12) of which one end has external splines, whilst the shaft (13) is associated with an element (20) or has a portion with a recess with internal splines adapted to co-operate with the external splines of the shaft (12) to ensure that the shafts (12, 13) are coupled to one another, while still permitting an axial displacement between them.
  8. Engine as claim 7, characterised in that the shaft (13) is associated with a bearing housing journal (20) having internal splines co-operating with the external splines of the shaft (12)., and in that advantageously, to reinforce the axial rigidity between the short-stroke crankshaft (5) and the variably timed transmission (10), the shafts (12 and 13) are merged into a single shaft in such a way as to allow the transmission shaft (35) including the disc (40) and the straight splines (47) to be associated with the short-stroke crankshaft (5), the separation distance between the fastening supports of the disc (40) and the bearing plate (15) being advantageously made at the same separation distance between fastening of the cylinder housing (1) of the bearing plate (15) and the fastening support of the disc (40) when the short-stroke crankshaft is inserted into the bearing housings of the cylinder housing.
  9. Engine as any of the preceding claims, in which the cylinder head gasket extends, roughly, in a plane, characterised in that, in relation to the cylinder head gasket plane, the axis of the cylinders (2) of the first series is positioned, more or less, perpendicularly to the cylinder head plane (29).
  10. Engine as any of claims 1 to 9, characterised in that it has a cylinder head adapted to receive (for each cylinder from the second series) a part of the piston (8) in the top dead centre position, and to form, at least partially (for each cylinder from the second series), when the piston (8) is at top dead centre, a chamber positioned in the cylinder head, communicating with the channel (32).
  11. Engine as any of claims 1 to 10, characterised in that the axes of the cylinders (2) of the first series and the axes of the cylinders (3) of the second series are not positioned perpendicularly to the cylinder head plane (29).
  12. Engine as any of the preceding claims, characterised in that it includes an engine flywheel (26) orientated around and fastened to the end of the crankshaft (4) of the pistons of the cylinders of the first series, the said engine flywheel being advantageously positioned in a coupling housing (31).
  13. Engine as any of the preceding claims, characterised in that the variably timed transmission includes a tube or shaft (17) sliding axially in relation to the rotational axis of the crankshaft of the pistons of the cylinders of the second series, and in that it includes stop means to limit the movement travel of the variably timed transmission between a start-of stroke and an end-of-stroke.
  14. Engine as any of preceding claims, characterised in that the two crankshafts (4, 5) are associated with gears (14, 16) in direct contact, with the shafts turning in opposite rotational directions and at the same speed.
  15. Engine as any of the preceding claims, characterised in that it includes a control cylinder to vary the angular position between the two crankshafts (4,5) without passing through the intermediary of the engine flywheel (26) positioned at the rear of the engine, or characterised in that the control of the variably timed transmission (10) includes a guidance cylinder in direct contact to monitor the phase angle difference between the short-stroke crankshaft (5) and the long-stroke crankshaft (4).
  16. Engine as any of the preceding claims, in which the variably timed transmission (10) has a control mechanism to vary the lead angle between the crank of the second crankshaft (5) and the crank of the first crankshaft (4), by means of a hydraulic force amplifier having a controlled thrustor acting on the variably timed transmission (10), said transmission altering at the end of the compression phase of the piston (6) in the larger cylinder (2), the compression ratio of the engine between a minimum and a maximum, said minimum and maximum compression ratios depending on:
    a) the ratio between the displacement of the larger cylinder (2) and the displacement of the smaller cylinder (3), and
    b) the ratio between, on the one hand, the total volume of the smaller cylinder and the larger cylinder and between, on the other hand, the volume of the clearance space (24) and an additional volume created in the smaller cylinder (3) at the end of the compression phase of the piston (6) in the larger cylinder (2), the variably timed transmission (10) adjusting the lead angle between the crank of the second crankshaft (5) and the crank of the first crankshaft (4), so as to obtain said compression ratios, said lead angle varying between a maximum so that an angle of at least 90° is obtained between the connecting rod (9) of the piston (8) in the smaller cylinder (3) and the crank of the second crankshaft (5), at the end of the compression phase of the piston (6) in the larger cylinder (2), in order to define the minimum compression ratio, and a minimum so that the lead angle corresponds, at the end of the compression phase of the piston (6) in the larger cylinder (2), to the appropriate position of the piston (8) in the smaller cylinder (3) to create the additional volume required to obtain the maximum compression ratio, the crank of the second crankshaft (5) forming an angle with the connecting rod (9) of the piston (8) in the smaller cylinder (3).
  17. Engine as any of the preceding claims, for which the crank of the first crankshaft (4) passes through a top dead centre and a bottom dead centre during its rotation, characterised in that the two crankshafts (4,5) are arranged to define a minimum working space for the two crankshafts, in such a way that a minimal ratio is obtained between the displacements of two paired cylinders (2,3) and in which the variably timed transmission travels between a start-of-travel position and an end-of-travel position, the minimum compression ratio of the paired cylinders (2,3) being obtained at the end-of-travel of the variably timed transmission and calculated according to the following formula: V ⁢ 1 + V ⁢ 2 - Vr α max ⁢ imum + ve ve + Va α max ⁢ imum = P min ⁢ imum
    Figure imgb0012
    in which
    V1: displacement of the larger cylinder (2) of the paired cylinders (2, 3).
    V2: displacement of the smaller cylinder (3) of the paired cylinders (2, 3).
    ve: volume of the clearance space (24) of the paired cylinders (2, 3) required for gas transfer between the cylinders (2, 3), without excessive lamination.
    (α maximum): lead angle of the crank of the second crankshaft (5), at the end-of-travel of the variably timed transmission.
    Vr (α maximum): compressed air volume at the end-of-travel of the variably timed transmission, defined by the lead angle of the crank of the second crankshaft (5), when the crank of the first crankshaft (4) is located at its bottom dead centre, at the end of the intake phase.
    Va (α maximum): additional volume added to the clearance space volume (24), at the end-of-travel of the variably timed transmission, defined by the lead angle of the crank of the second crankshaft (5), when the crank of the first crankshaft (4) is located at its top dead centre, at the end of the compression phase.
  18. Appliance or apparatus or machine including at least one engine as any of claims 1 to 17.
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Families Citing this family (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US8272356B2 (en) * 2009-06-30 2012-09-25 The United States of America, as represented by the Administrator of the United States Environmental Protection Agency Two mode dual crankshaft engine
LU91831B1 (en) * 2011-06-24 2012-12-27 Gilbert Lucien Ch H L Van Avermaete Internal combustion engine with variable-timing transmission
US8763570B2 (en) * 2011-09-14 2014-07-01 GM Global Technology Operations LLC Engine assembly including multiple bore center pitch dimensions
US8443769B1 (en) 2012-05-18 2013-05-21 Raymond F. Lippitt Internal combustion engines
US9719444B2 (en) 2013-11-05 2017-08-01 Raymond F. Lippitt Engine with central gear train
US9664044B2 (en) 2013-11-15 2017-05-30 Raymond F. Lippitt Inverted V-8 I-C engine and method of operating same in a vehicle
US9217365B2 (en) * 2013-11-15 2015-12-22 Raymond F. Lippitt Inverted V-8 internal combustion engine and method of operating the same modes
WO2015184448A1 (en) * 2014-05-30 2015-12-03 Lippitt Raymond F Inverted v-8 i-c engine and method of operating same in a vehicle
US10408095B2 (en) * 2015-01-05 2019-09-10 Edward Charles Mendler Variable compression ratio engine camshaft drive
FR3047043B1 (en) * 2016-01-26 2018-01-26 IFP Energies Nouvelles INTERNAL COMBUSTION ENGINE WITH VARIABLE COMPRESSION RATE WITH TWO MIXING ZONES, ESPECIALLY FOR A MOTOR VEHICLE AND INJECTION METHOD FOR SUCH AN ENGINE.
CN109854370A (en) * 2019-03-11 2019-06-07 湖南大兹动力科技有限公司 A kind of variable compression ratio internal combustion engine
US11519342B2 (en) * 2021-02-11 2022-12-06 Schaeffler Technologies AG & Co. KG Cranktrain phase adjuster for variable compression ratio
US20230023207A1 (en) * 2021-07-21 2023-01-26 Schaeffler Technologies AG & Co .KG Cranktrain phase adjuster for variable compression ratio

Family Cites Families (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2137941A (en) * 1936-04-08 1938-11-22 Helmore William Internal combustion engine
FR1032534A (en) * 1951-02-16 1953-07-02 System of an inverted v-engine unit with opposing pistons in pairs and capable of high ignition compression
US3961607A (en) * 1972-05-12 1976-06-08 John Henry Brems Internal combustion engine
US4876992A (en) * 1988-08-19 1989-10-31 Standard Oil Company Crankshaft phasing mechanism
LU88235A1 (en) 1993-03-19 1994-10-03 Gilbert Van Avermaete Improvements made to four-stroke internal combustion engines, with variable volumetric ratio allowing high rates of boost pressure and operating by compression ignition or by controlled ignition
CA2339315A1 (en) * 2001-02-19 2002-08-19 Heru Santoso Delta pair combustion engine

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CN101371019A (en) 2009-02-18
DE602007004945D1 (en) 2010-04-08
ES2341301T3 (en) 2010-06-17
WO2007082355A1 (en) 2007-07-26
US20090020103A1 (en) 2009-01-22
BE1016961A3 (en) 2007-11-06
US7730856B2 (en) 2010-06-08
EP1977097A1 (en) 2008-10-08
CN101371019B (en) 2012-10-31

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