Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02N—STARTING OF COMBUSTION ENGINES; STARTING AIDS FOR SUCH ENGINES, NOT OTHERWISE PROVIDED FOR
  • F02N15/00—Other power-operated starting apparatus; Component parts, details, or accessories, not provided for in, or of interest apart from groups F02N5/00 - F02N13/00
  • F02N15/02—Gearing between starting-engines and started engines; Engagement or disengagement thereof
  • F02N15/04—Gearing between starting-engines and started engines; Engagement or disengagement thereof the gearing including disengaging toothed gears
  • F02N15/06—Gearing between starting-engines and started engines; Engagement or disengagement thereof the gearing including disengaging toothed gears the toothed gears being moved by axial displacement
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02N—STARTING OF COMBUSTION ENGINES; STARTING AIDS FOR SUCH ENGINES, NOT OTHERWISE PROVIDED FOR
  • F02N15/00—Other power-operated starting apparatus; Component parts, details, or accessories, not provided for in, or of interest apart from groups F02N5/00 - F02N13/00
  • F02N15/02—Gearing between starting-engines and started engines; Engagement or disengagement thereof
  • F02N15/04—Gearing between starting-engines and started engines; Engagement or disengagement thereof the gearing including disengaging toothed gears
  • F02N15/06—Gearing between starting-engines and started engines; Engagement or disengagement thereof the gearing including disengaging toothed gears the toothed gears being moved by axial displacement
  • F02N15/062—Starter drives
  • F02N15/063—Starter drives with resilient shock absorbers
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02N—STARTING OF COMBUSTION ENGINES; STARTING AIDS FOR SUCH ENGINES, NOT OTHERWISE PROVIDED FOR
  • F02N15/00—Other power-operated starting apparatus; Component parts, details, or accessories, not provided for in, or of interest apart from groups F02N5/00 - F02N13/00
  • F02N15/02—Gearing between starting-engines and started engines; Engagement or disengagement thereof
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02N—STARTING OF COMBUSTION ENGINES; STARTING AIDS FOR SUCH ENGINES, NOT OTHERWISE PROVIDED FOR
  • F02N15/00—Other power-operated starting apparatus; Component parts, details, or accessories, not provided for in, or of interest apart from groups F02N5/00 - F02N13/00
  • F02N15/02—Gearing between starting-engines and started engines; Engagement or disengagement thereof
  • F02N15/022—Gearing between starting-engines and started engines; Engagement or disengagement thereof the starter comprising an intermediate clutch
  • F02N15/023—Gearing between starting-engines and started engines; Engagement or disengagement thereof the starter comprising an intermediate clutch of the overrunning type

Definitions

• the invention relates to an electric starter equipped with a rotary output shaft and a launcher for driving a ring gear of the flywheel of a vehicle combustion engine, said launcher comprising:
• a pinion which can slide axially on the rotary output shaft between a rest position in which it is disengaged from the crown, and an active working position in which it meshes with said crown, a disengageable torque transmission device, such as a freewheel or bevel clutch device.
• a motor vehicle starter conventionally comprises a rotary electric motor intended to rotate an output shaft equipped with a movable pinion intended to cooperate with a ring gear to ensure the starting of the combustion engine of the vehicle.
• the toothed crown is called the starting crown and is secured to one another by an annular part, such as an engine flywheel, rigidly or resiliently connected to the crankshaft of the internal combustion engine of the motor vehicle.
• the output shaft is in one embodiment confused with the output shaft of the electric starter motor.
• the output shaft is separate from the output shaft of the electric starter motor.
• an epicyclic train is arranged between the two shafts as described in document EP B 0 708 239 or in document FR A 2 751 803.
• the pinion is generally slidably mounted on the output shaft between a rest position, in which it is disengaged from the ring gear, and an active working position in which it meshes with said ring gear, which is linked in rotation to the crankshaft of the vehicle engine.
• a control member usually in the form of an actuating lever, is controlled by a contactor, and cooperates with a starter with freewheel or conical clutch.
• the bevel clutch or the freewheel is arranged between the pinion and a trainer belonging to the starter.
• the lever acts on the driver or on a housing that includes the freewheel or the conical clutch. In a conventional starter, the housing is integral with the driver.
• This driver comprises a drive bushing having at its internal periphery helical grooves cooperating in a complementary manner with helical grooves that the output shaft has locally at its external periphery. In the active position the pinion cooperates with a stop integral with the output shaft.
• the main function of the disengageable torque transmission device is to prevent the motor vehicle from starting when the internal combustion engine, also called the internal combustion engine, starts, the pinion drives the electric motor of the starter motor at too high a speed likely to deteriorate this latest.
• the documents FR 96 13016, FR 96 13015 and FR 96 09550 - published respectively under the numbers FR 2 754 857, FR 2 754 856 and FR 2 751 803 - relate to damping devices intended to absorb the shocks and vibrations generated during starter operation.
• the damping function results in. a reduction in the intensity of the shocks received at the launcher.
• These damping devices are generally constituted by elastomer damping blocks, the role of which is to absorb energy to dissipate it in the form of internal friction depending on the structure of the material, and of external friction between the parts in relative movement.
• the damping devices are mounted in a housing integral with the driver.
• the damping device is mounted between the output shaft and the output element of the reduction gear.
• the piston compresses the mixture of air and fuel, and the internal pressure gradually increases up to the Top Dead Center called hereinafter TDC.
• TDC Top Dead Center
• the starter which drives the thermal engine in rotation must therefore provide an increasingly high torque until TDC, which results in a decrease in the drive speed.
• the cylinder enters the decompression phase, during which the internal pressure creates an engine torque which accelerates the speed of rotation of the crankshaft. Taking into account the respective torques and moments of inertia of the engine and the starter, the acceleration of the crankshaft is faster than that of the starter pinion.
• the pinion is therefore driven by the heat engine, and is driven alone in overspeed following the intervention of the freewheel or the bevel clutch between the pinion and the electric motor of the starter.
• the heat engine then continues its acceleration movement to the bottom dead center, later called PMB.
• a compression phase appears in the next cylinder in the order of ignition, causing the crankshaft to slow down.
• the electric motor of the starter having no more load to transmit, sees its speed increase according to the conventional laws of rise in idle speed of electric motors.
• the freewheel or the bevel clutch locks, and the starter again supplies a torque to the heat engine.
• the torque of the cylinder in compression makes the starter slow down which delivers an increasingly high torque until TDC, and so on until the appearance of the first explosions. It is noted that from time tl, the speed of the combustion engine N m and the speed of the starter N d are different.
• the starter is therefore sometimes leading, sometimes driven.
• At the start of each training period there is a take-up of the angular clearances, and of the axial clearance between the pinion and the stop. This game catch-up results in a shock and a noise emission.
• the load on the pinion / crown gear increases until TDC, and these load variations also result in noise emission.
• the interval RL corresponds to the freewheeling period
• the interval EN corresponds to the training period.
• the object of the invention is to eliminate the backlash of the transmission elements to reduce the noise of the starter launcher during the drive period of the engine.
• the device according to the invention is characterized in that the launcher is equipped with an elastic torsional device arranged to store energy during the compression phases of the heat engine, and to restore it during the decompression phases and in that the torsional elastic device is axially offset relative to the disengageable torque transmission device.
• the torsional elastic device initially compresses during the compression phases of the vehicle's heat engine, then, in a second step, restores the accumulated energy to give an angular acceleration to the pinion greater than that of the crankshaft. the engine of the vehicle.
• This elastic device in torsion for a given radial size may have a large size because it is axially offset with respect to the disengageable torque transmission device.
• This arrangement makes it possible to conserve and spare the free wheel or the conical clutch and therefore to increase the life of the starter while reducing noise.
• the torsional elastic device advantageously comprises a spiral spring attached to the spiral coaxially surrounding the output shaft, being hung between a casing of the freewheel or of the conical clutch and a part integral with the pinion or the driver.
• the torsional elastic device is housed between the pinion and the disengageable torque transmission device, such as a freewheel device or a conical clutch.
• This torsional elastic device comprises a spiral spring coaxially surrounding the output shaft, being hung between a casing of the freewheel or the conical clutch and a tubular extension of the pinion.
• the elastic torsion device is not directly engaged with the shaft of the electric motor of the starter.
• This preferred embodiment is simple, reliable and economical because it comprises a minimum number of parts and makes it possible to simplify the pinion devoid of track for a freewheel or conical clutch device.
• the trainer is also simplified because the track or the internal friction surface of the disengageable torque transmission device is advantageously secured to the trainer so that the housing associated with this torque transmission device is separate from the trainer and the pinion and is simple to manufacture.
• This preferred embodiment also makes it possible to further reduce the internal diameter of the spiral spring, which thus for a given external diameter can store the maximum of energy.
• the spiral spring is trapped in a simple, reliable and economical manner in a compartment of the housing by means of a closing disc secured to the pinion.
• the closing disc has at least one protruding sector housed in a cutout of the housing, which has an angular width greater than the sector angle so that the angular movement of the disc by relation to the housing corresponds to the difference between the two angles;
• the spring is prestressed so as to exert a restoring torque tending to bring the sector of the disc against a stop of the housing to obtain a predetermined angular positioning of the pinion relative to the housing when the starter is in the rest state;
• the housing is provided with a second compartment for housing the rollers of the freewheel or the frustoconical surfaces of the conical clutch;
• the housing is centered and guided on the output shaft by means of a self-lubricating ring to allow the rotary movements of translation and rotation of the launcher.
• FIG. 1 shows the compression and decompression cycle in a combustion engine cylinder during startup
• - Figure 2 is a half sectional view of a starter launcher according to the invention
• Figure 3 shows a sectional view of the launcher housing of Figure 2
• Figure 4 is a side view of Figure 3;
• FIG. 5 is a sectional view along line 5-5 of Figure 3;
• Figure 6 shows a perspective view of the spiral spring constituting the torsional elastic device;
• - Figure 7 shows an elevational view of the closing disc of the launcher housing;
• Figure 8 shows a sectional view of the pinion and closing disc assembly;
• FIG. 9 illustrates the torque generated by the spiral spring as a function of the relative position of the pinion relative to the housing.
• the launcher 10 comprises a pinion 12 and a disengageable torque transmission device here with free wheel 14, which is composed of a driver 16 and a housing 17, here of annular shape, delimiting here a housing for pebbles 19.
• the driver 16 is equipped, as mentioned above, with helical splines 16a cooperating with splines 16b complementary to the output shaft 18 intended to be driven in rotation by the electric motor of the starter.
• This shaft 18 is in one embodiment in one piece with the output shaft of the electric motor or alternatively separate from the output shaft of the electric motor; a planetary gear reducer intervening for example then between the two shafts.
• the structure of the grooves 16a, 16b allows the connection in rotation and the axial movement of the launcher 10.
• a bore 20 is formed in the driver 16 to ensure the centering of the track cylindrical 22 of the freewheel 14 on the shaft 18.
• the splines 16a belong to a drive bush (not referenced) extending axially towards the rear, in the direction opposite to the pinion 12, the track 22 formed in favor of a protuberance that the coach presents locally at its outer periphery.
• the housing 17 has is hollowed out at its outer periphery to form inclined ramps 24, constituting cams, causing, in a known manner, the jamming of the rollers 19 in a direction of rotation of the shaft 18, and the release of the rollers 19 reverse.
• This housing is centered and guided on the shaft 18 by means of a self-lubricating ring 26 allowing the relative movements of translation and rotation.
• the housing 17 also includes shouldered housings for pressure springs acting in a known manner on the rollers 19 to wedge them between the track 22 and the ramps 24.
• a torsional elastic device 28 is mounted within the launcher in an axially offset manner relative to the disengageable torque transmission device.
• This device stores energy during the compression phases of the heat engine of the motor vehicle and restores this energy during the decompression phases of this heat engine.
• this device 28 consists of a spiral spring hung between the housing 17 and a part belonging to the pinion or to the driver. This spring is housed in a compartment of the housing 17.
• This device 28 is in one embodiment disposed between the housing 17 and the driver 16.
• This device is arranged in the embodiment shown between the pinion 12 and the freewheel 14.
• the housing 17 is extended on the left side by a tubular sleeve 30, delimiting a compartment 31 for receiving a spiral spring 32 constituting said torsional elastic device 28.
• the spiral spring 32 is provided with a recess 34 on the end of its outer turn allowing the latter to make a rotational connection with a tongue 36 of complementary shape disposed in the socket 30 of the housing 17.
• the stop in rotation must be at least unidirectional in the direction of compression of the spring 32.
• the recess 34 has a rectangular section in which the end of the tongue 36 of the sleeve 30 is placed. It is clear that the male and female parts of the connection can be reversed.
• the other end on the inner turn is provided with a lug 38 allowing it to be hooked at least in the direction of rotation necessary for the compression of the spiral spring 32.
• the lug 38 is formed by a radial bending towards the inside of the ribbon constituting the spring 32. This bent end is housed in a slot 33 arranged in the tubular extension 40 of the pinion 12.
• a closing disc 42 extends between the sleeve 30 and the extension 40 to trap the spiral spring 32 in the compartment 31.
• the disc 42 is fixed to the pinion 12 by welding, riveting or any other known fixing means.
• the outer part of the disc 42 of a thickness el, has a diameter D1 substantially equal to the outside diameter D2 of the tubular sleeve 30.
• Two circular recesses 44 locally reduce the outside diameter to a value D3 less than the internal diameter D4 of the sleeve 30 (FIG. 3), so as to form two protruding sectors 46 of angle A and diametrically opposite. Each sector is delimited by two faces 54 and 50 here radial ( Figure 7).
• the end of the sleeve 30 has cutouts 48 intended to receive the sectors 46 of the disc 42.
• Each cutout 48 is delimited by two faces 52 and 56, here radial, of the socket 30 and has a depth e2 slightly greater than the thickness el of the disc 42, and an angular width B> A.
• the faces 50 and 54 d a sector 46 are intended to come into contact respectively with the faces 52 and 56 of the sleeve 30 of the housing 17.
• the spring 32 which is prestressed, exerts a torque C 0 tending to bring the face 50 of the disc 42 against the face 52 of the housing 17, so as to angularly position the pinion 12 relative to the housing 17 when the starter is at rest.
• a cover 55 (FIG. 2) consists of a tube made of deformable material, comprising two folded ends which close the housing 17 by trapping all the components of the launcher 10. The cover is in contact by its internal periphery with the cylindrical external periphery of the housing 17 comprising the external periphery of the sleeve 30.
• This cover 55 has a folded end which serves to hold a disc 142 closing the freewheel device 14 and serving as a support for the control member, such as a lever , supra.
• FIG. 9 illustrates the torque generated by the spiral spring 32 as a function of the relative position PA of the pinion 12 with respect to the housing 17.
• the spring 32 restores energy by accelerating the speed of the pinion 12, which has a very low inertia with respect to the electric motor of the starter.
• the spring 32 is relaxed to the angle A ⁇ corresponding to a torque C m supplied by the spring.
• the energy supplied to the pinion 12 is represented diagrammatically by the area of the trapezoid PQRS. This results in permanent contact of the pinion 12 against the ring gear of the combustion engine.
• A- must be greater than 0 at the end of each decompression.
• d must be greater than A_ so as not to have a significant impact from the face 54 against the face 56 of the housing 17.
• the spring 32 returns to its rest position bringing the face 50 of the disc 42 against the housing 17.
• An elastic element can be interposed between the two bearing faces to reduce the noise at the end of starting.
• the freewheel 14 comes into action to allow the speed differential between the pinion 12 driven by the heat engine and the starter shaft 18.
• the track 22 and the ramps 24 are alternatively of frustoconical shape to form a conical clutch with frustoconical friction surface as described for example in documents FR A 2 772 433 or FR A 2 827 915.
• the rollers are eliminated as well as the pressure springs associated with the rollers and the driver can be made of plastic.
• This trainer then advantageously takes the form of that of FIG. 3 of the document FR A 2 827 915, the control member of the launcher then being associated with the trainer.
• the additional frustoconical friction surfaces can be added.
• the external periphery of the housing 17 has at its external periphery in one embodiment the sleeve 30 and a wall of frustoconical shape carrying at its internal periphery one of the frustoconical friction surfaces of the conical clutch.
• the spring 32 according to the invention would be mounted in a housing delimited by the wall 1a of this FIG. 8 and by the sleeve 30 of FIG. 2 according to the invention, the spring 32 acting between the housing and the extension 40 of the pinion.
• the housing 17 has an annular wall 117 of transverse orientation with respect to the axis of axial symmetry of FIG. 2.
• This wall 117 is perforated centrally for centering the housing on the sleeve 26 shouldered for this purpose
• the bush 26 extends in axial projection relative to the wall 117 so that the coach can come into contact with the latter.
• the edge of the central hole of the wall 117 is shouldered to come contact with the shoulder of the sleeve (figure 2).
• This wall 117 delimits two housings extending on either side of the latter.
• One of the housings is dedicated to the spring 32 and the other to the freewheel or to the conical clutch.
• One of the housings, that of the spring 32 can therefore be of the standard type and the other adaptable according to the applications (freewheel or bevel clutch).
• driver 16 and the pinion 12 of Figure 2 have a simple shape because the wall 117 is separate from the driver and the pinion.
• the pinion 12 with its tubular extension 40 can be made of sintered material or any other suitable material because the elastic torsion device intervenes between the pinion and the disengageable torque transmission device with free wheel or conical clutch. .
• the pinion 12 is made of sintered material attached to a bushing to which the extension 40 belongs.

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• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Valve Device For Special Equipments (AREA)
• Output Control And Ontrol Of Special Type Engine (AREA)
• Mechanical Operated Clutches (AREA)
• One-Way And Automatic Clutches, And Combinations Of Different Clutches (AREA)
• Jellies, Jams, And Syrups (AREA)
• Devices For Conveying Motion By Means Of Endless Flexible Members (AREA)

Priority Applications (3)

Applications Claiming Priority (2)

Publications (1)

Family

ID=27763526

Family Applications (1)

Country Status (6)

Cited By (3)

Families Citing this family (2)

Citations (5)

Family Cites Families (1)

• 2002
  • 2002-02-28 FR FR0202535A patent/FR2837532B1/fr not_active Expired - Fee Related
• 2003
  • 2003-02-25 WO PCT/FR2003/000602 patent/WO2003072935A1/fr active IP Right Grant
  • 2003-02-25 DE DE60320536T patent/DE60320536T2/de not_active Expired - Fee Related
  • 2003-02-25 AT AT03722671T patent/ATE393311T1/de not_active IP Right Cessation
  • 2003-02-25 KR KR10-2004-7013291A patent/KR20040091077A/ko not_active Application Discontinuation
  • 2003-02-25 EP EP03722671A patent/EP1478844B1/de not_active Expired - Lifetime

Patent Citations (5)

Non-Patent Citations (1)

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