CA2355038A1 - Two-cycle engine including improved exhaust valve mechanism, and method - Google Patents
Two-cycle engine including improved exhaust valve mechanism, and method Download PDFInfo
- Publication number
- CA2355038A1 CA2355038A1 CA002355038A CA2355038A CA2355038A1 CA 2355038 A1 CA2355038 A1 CA 2355038A1 CA 002355038 A CA002355038 A CA 002355038A CA 2355038 A CA2355038 A CA 2355038A CA 2355038 A1 CA2355038 A1 CA 2355038A1
- Authority
- CA
- Canada
- Prior art keywords
- exhaust valve
- primary
- axis
- engine
- movement
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02D—CONTROLLING COMBUSTION ENGINES
- F02D13/00—Controlling the engine output power by varying inlet or exhaust valve operating characteristics, e.g. timing
- F02D13/02—Controlling the engine output power by varying inlet or exhaust valve operating characteristics, e.g. timing during engine operation
- F02D13/028—Controlling the engine output power by varying inlet or exhaust valve operating characteristics, e.g. timing during engine operation for two-stroke engines
- F02D13/0284—Variable control of exhaust valves only
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01L—CYCLICALLY OPERATING VALVES FOR MACHINES OR ENGINES
- F01L1/00—Valve-gear or valve arrangements, e.g. lift-valve gear
- F01L1/36—Valve-gear or valve arrangements, e.g. lift-valve gear peculiar to machines or engines of specific type other than four-stroke cycle
- F01L1/38—Valve-gear or valve arrangements, e.g. lift-valve gear peculiar to machines or engines of specific type other than four-stroke cycle for engines with other than four-stroke cycle, e.g. with two-stroke cycle
-
- 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
- F02B27/00—Use of kinetic or wave energy of charge in induction systems, or of combustion residues in exhaust systems, for improving quantity of charge or for increasing removal of combustion residues
- F02B27/04—Use of kinetic or wave energy of charge in induction systems, or of combustion residues in exhaust systems, for improving quantity of charge or for increasing removal of combustion residues in exhaust systems only, e.g. for sucking-off combustion gases
-
- 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
- F02B75/02—Engines characterised by their cycles, e.g. six-stroke
- F02B2075/022—Engines characterised by their cycles, e.g. six-stroke having less than six strokes per cycle
- F02B2075/025—Engines characterised by their cycles, e.g. six-stroke having less than six strokes per cycle two
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02D—CONTROLLING COMBUSTION ENGINES
- F02D9/00—Controlling engines by throttling air or fuel-and-air induction conduits or exhaust conduits
- F02D9/04—Controlling engines by throttling air or fuel-and-air induction conduits or exhaust conduits concerning exhaust conduits
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02D—CONTROLLING COMBUSTION ENGINES
- F02D9/00—Controlling engines by throttling air or fuel-and-air induction conduits or exhaust conduits
- F02D9/08—Throttle valves specially adapted therefor; Arrangements of such valves in conduits
- F02D9/12—Throttle valves specially adapted therefor; Arrangements of such valves in conduits having slidably-mounted valve members; having valve members movable longitudinally of conduit
- F02D9/14—Throttle valves specially adapted therefor; Arrangements of such valves in conduits having slidably-mounted valve members; having valve members movable longitudinally of conduit the members being slidable transversely of conduit
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
- Y02T10/00—Road transport of goods or passengers
- Y02T10/10—Internal combustion engine [ICE] based vehicles
- Y02T10/12—Improving ICE efficiencies
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Valve Device For Special Equipments (AREA)
Abstract
A two-cycle engine includes a primary exhaust valve that is installed so as to be able to slide within a guiding passageway in a wall proximate to the cylinder head. A slidable secondary exhaust valve is slidable in a direction parallel to the primary exhaust valve and can be used to restrict flow through a secondary exhaust for the cylinder. Preferably the sliding direction of the primary exhaust valve subtends an acute angle with the axis of the cylinder. Primary and secondary exhaust valves may conveniently be actuated by a common drive.
Description
TWO-CYCLE ENGINE INCLUDING IMPROVED EXHAUST VALVE MECHANISM, AND METHOD
FIELD OF THE INVENTION
The present invention relates to two-cycle engines, and more particularly to a mechanism and method for controlling the exhaust of a two-cycle engine.
BACKGROUND OF THE INVENTION
to So that two-cycle engines can deliver peak performance at high speeds, it is desirable that they receive a full charge and that charge losses are kept as small as possible. This is achieved, on the one hand, by appropriately early opening of the exhaust port and, on the other, by exploiting the resonance of the exhaust system.
is Matching the exhaust system to the peak output of the engine, however, typically results in a noticeable loss of usable piston travel and a marked increase in charge losses in the middle of the engine-speed range, because of the comparatively high level of exhaust. This, in turn, is concomitant with a reduction in torque and an increase in fuel consumption.
In the lower speed range, torque can be increased with a simultaneous reduction in fuel consumption by reducing the exhaust. As such, US Patent No.
4,399,788 discloses an exhaust valve (restricting member) slideable within a passageway in the wall of an associated exhaust duct. This exhaust valve is 2s proximate to the cylinder head and subtends an acute angle with the axis of the cylinder. At its unattached end, the exhaust valve forms a restricting edge that is matched to the cylinder bore. In its working position, the exhaust valve is advanced toward the cylinder and partially covers the exhaust port, thereby varying its axial extent. This results in a corresponding reduction of the time the exhaust port is open.
In order to ensure that the exhaust duct is largely obstructed in the exhaust s valve's working position it may be flush with the cylinder bore across the whole width of the exhaust port. For example, German Patent Document DE 195 35 069 A1 disclosed an exhaust valve including a parallel-slide gate valve having a curved guide surface, in a plane that is at right angles to the direction of movement of the valve.
io In other known two-stroke engines, secondary exhausts for the cylinder are provided in addition to the primary exhaust in order to enhance exhaust performance, and thereby increase the maximal throughput of gas. Typically, secondary exhausts are connected to the primary exhaust duct by way of secondary is ducts. In order to shorten the effective exhaust time, these secondary exhausts may be closed. This is typically effected by roller-like blocking members that pass through the secondary ducts and can rotate between a closed position and an open position, about an axis of rotation perpendicular to the axis of the cylinder (JP 8-158870). The roller-like blocking members incorporate a recess for opening the 2o secondary ducts. So that the blocking members can be actuated using a valve mechanism for a sliding exhaust valve in the primary exhaust duct, the roller-like blocking bodies are typically connected to the valve mechanism through a complicated linkage.
2s Still other engines, such as those disclosed in European patent document EP
0 141 650 A2 incorporate secondary exhausts, controlled by a valve in dependence on the engine speed, so that the secondary exhaust is only opened at higher engine speeds. These known engines, however, do not also control the exhaust of the primary exhaust.
FIELD OF THE INVENTION
The present invention relates to two-cycle engines, and more particularly to a mechanism and method for controlling the exhaust of a two-cycle engine.
BACKGROUND OF THE INVENTION
to So that two-cycle engines can deliver peak performance at high speeds, it is desirable that they receive a full charge and that charge losses are kept as small as possible. This is achieved, on the one hand, by appropriately early opening of the exhaust port and, on the other, by exploiting the resonance of the exhaust system.
is Matching the exhaust system to the peak output of the engine, however, typically results in a noticeable loss of usable piston travel and a marked increase in charge losses in the middle of the engine-speed range, because of the comparatively high level of exhaust. This, in turn, is concomitant with a reduction in torque and an increase in fuel consumption.
In the lower speed range, torque can be increased with a simultaneous reduction in fuel consumption by reducing the exhaust. As such, US Patent No.
4,399,788 discloses an exhaust valve (restricting member) slideable within a passageway in the wall of an associated exhaust duct. This exhaust valve is 2s proximate to the cylinder head and subtends an acute angle with the axis of the cylinder. At its unattached end, the exhaust valve forms a restricting edge that is matched to the cylinder bore. In its working position, the exhaust valve is advanced toward the cylinder and partially covers the exhaust port, thereby varying its axial extent. This results in a corresponding reduction of the time the exhaust port is open.
In order to ensure that the exhaust duct is largely obstructed in the exhaust s valve's working position it may be flush with the cylinder bore across the whole width of the exhaust port. For example, German Patent Document DE 195 35 069 A1 disclosed an exhaust valve including a parallel-slide gate valve having a curved guide surface, in a plane that is at right angles to the direction of movement of the valve.
io In other known two-stroke engines, secondary exhausts for the cylinder are provided in addition to the primary exhaust in order to enhance exhaust performance, and thereby increase the maximal throughput of gas. Typically, secondary exhausts are connected to the primary exhaust duct by way of secondary is ducts. In order to shorten the effective exhaust time, these secondary exhausts may be closed. This is typically effected by roller-like blocking members that pass through the secondary ducts and can rotate between a closed position and an open position, about an axis of rotation perpendicular to the axis of the cylinder (JP 8-158870). The roller-like blocking members incorporate a recess for opening the 2o secondary ducts. So that the blocking members can be actuated using a valve mechanism for a sliding exhaust valve in the primary exhaust duct, the roller-like blocking bodies are typically connected to the valve mechanism through a complicated linkage.
2s Still other engines, such as those disclosed in European patent document EP
0 141 650 A2 incorporate secondary exhausts, controlled by a valve in dependence on the engine speed, so that the secondary exhaust is only opened at higher engine speeds. These known engines, however, do not also control the exhaust of the primary exhaust.
Accordingly, there is a need for a two-cycle engine with an improved mechanism for controlling the engine exhaust.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide a two-cycle engine including primary and secondary exhaust ducts and associated control valves operable to vary the duration of an open exhaust using a mechanism that may be easily constructed.
io In accordance with an embodiment of the present invention a two-cycle engine includes a primary exhaust valve that is installed so as to be able to slide within a guiding passageway in a wall proximate to the cylinder head, so as to subtend an acute angle with the axis of the cylinder. A slidable secondary exhaust is valve that may be moved in a direction parallel to the primary exhaust valve can be used to restrict flow through a secondary exhaust for the cylinder.
Conveniently, by providing a primary exhaust valve having an actuating movement that is parallel to movement of the secondary exhaust valve, the 2o secondary exhaust valve need only be installed so as to slide in a bore in the wall of the exhaust duct that is parallel to the guiding passageway for the primary exhaust valve. Conveniently, this bore may pass through the secondary duct, so that in its forward, working position, the secondary exhaust valve closes off the secondary duct, leaving it open when the secondary exhaust valve is in its retracted, normal 2s position.
Because the directions of movements of primary and secondary exhaust valves coincide; it is much simpler to couple the drives for the primary exhaust valve and the secondary exhaust valve slide. The secondary exhaust valve and the primary exhaust valve can be operated in an advantageous manner by way of a common actuating head that works against a spring. The spring may act in the direction of the working position or in the direction of the normal position.
s In order to even out unequal actuating travel but at the same time permit actuation of the primary exhaust valve and of the secondary exhaust valve that is staggered over time-which can also allow the timing of the exhaust to be adapted to a wide range of engine speeds-the secondary exhaust valve can be installed so as to be able to slide relative to the primary exhaust valve. This sliding can be io limited by a stop, without the need to provide separate drive systems for the two valves. In this regard, a particularly simple construction will result if the primary exhaust valve and the secondary exhaust valve are acted upon by separate springs in the direction of their working positions. So arranged, the secondary exhaust valve, for example, can be moved within the mutual displacement travel relative to is the primary control valve, when urged into its working position. As such, when the primary exhaust valve is in its working position, the secondary exhaust may be moved independently.
The common actuating head can be driven pneumatically. For example, a 2o diaphragm that is accommodated in a diaphragm cell and connected to the actuating head through a rod as disclosed in US Patent No. 4,399,788 may be employed.
Alternatively, the common actuating head may be positioned by a rack and pinion. A
toothed rack may be arranged on the guide shaft of the actuating head, and a pinion may engage this rack. Alternatively, the guide shaft of the actuating head may 2s include a thread or a side pin to be driven by a threaded bushing that is associated with the thread or by a guideway bushing associated with the pin.
Another advantageous arrangement for operating the primary and secondary exhaust valves includes a common guide rod having guideways machined therein.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide a two-cycle engine including primary and secondary exhaust ducts and associated control valves operable to vary the duration of an open exhaust using a mechanism that may be easily constructed.
io In accordance with an embodiment of the present invention a two-cycle engine includes a primary exhaust valve that is installed so as to be able to slide within a guiding passageway in a wall proximate to the cylinder head, so as to subtend an acute angle with the axis of the cylinder. A slidable secondary exhaust is valve that may be moved in a direction parallel to the primary exhaust valve can be used to restrict flow through a secondary exhaust for the cylinder.
Conveniently, by providing a primary exhaust valve having an actuating movement that is parallel to movement of the secondary exhaust valve, the 2o secondary exhaust valve need only be installed so as to slide in a bore in the wall of the exhaust duct that is parallel to the guiding passageway for the primary exhaust valve. Conveniently, this bore may pass through the secondary duct, so that in its forward, working position, the secondary exhaust valve closes off the secondary duct, leaving it open when the secondary exhaust valve is in its retracted, normal 2s position.
Because the directions of movements of primary and secondary exhaust valves coincide; it is much simpler to couple the drives for the primary exhaust valve and the secondary exhaust valve slide. The secondary exhaust valve and the primary exhaust valve can be operated in an advantageous manner by way of a common actuating head that works against a spring. The spring may act in the direction of the working position or in the direction of the normal position.
s In order to even out unequal actuating travel but at the same time permit actuation of the primary exhaust valve and of the secondary exhaust valve that is staggered over time-which can also allow the timing of the exhaust to be adapted to a wide range of engine speeds-the secondary exhaust valve can be installed so as to be able to slide relative to the primary exhaust valve. This sliding can be io limited by a stop, without the need to provide separate drive systems for the two valves. In this regard, a particularly simple construction will result if the primary exhaust valve and the secondary exhaust valve are acted upon by separate springs in the direction of their working positions. So arranged, the secondary exhaust valve, for example, can be moved within the mutual displacement travel relative to is the primary control valve, when urged into its working position. As such, when the primary exhaust valve is in its working position, the secondary exhaust may be moved independently.
The common actuating head can be driven pneumatically. For example, a 2o diaphragm that is accommodated in a diaphragm cell and connected to the actuating head through a rod as disclosed in US Patent No. 4,399,788 may be employed.
Alternatively, the common actuating head may be positioned by a rack and pinion. A
toothed rack may be arranged on the guide shaft of the actuating head, and a pinion may engage this rack. Alternatively, the guide shaft of the actuating head may 2s include a thread or a side pin to be driven by a threaded bushing that is associated with the thread or by a guideway bushing associated with the pin.
Another advantageous arrangement for operating the primary and secondary exhaust valves includes a common guide rod having guideways machined therein.
Primary and secondary exhaust valves can be controlled completely independently of each other, depending only on the particular shape of the guideways.
In accordance with an aspect of the present invention, there is provided a s two-cycle combustion engine comprising: a combustion cylinder having a cylinder axis; a primary exhaust duct in flow communication with an exhaust port for the cylinder; a secondary exhaust duct in flow communication with the primary exhaust duct; a primary exhaust valve slidably mounted to the cylinder, and moveable along an axis of movement between a normal position and a working position whereat the 1o primary exhaust valve extends into the primary exhaust duct, to partially obstruct the primary exhaust duct; a secondary exhaust valve, moveable along an axis of movement generally parallel to the axis of movement of the primary exhaust valve, between a normal position and a working position whereat the secondary exhaust valve at least partially obstructs the secondary exhaust duct. A drive operably is connects the primary exhaust valve and the secondary exhaust valve to move the primary exhaust valve and the secondary exhaust valves between their normal and working positions.
In accordance with another aspect of the present invention there is provided a 2o method of controlling the exhaust flow of a two-cycle engine comprising a cylinder having primary and secondary exhaust ducts associated therewith. The method includes driving an actuator to sequentially extend a secondary exhaust valve along an axis of movement to at least partially obstruct flow through the secondary exhaust duct, and thereafter extend a primary exhaust valve along an axis parallel to the axis 2s of movement of the secondary exhaust valve to obstruct flow through the primary exhaust duct.
In accordance with a further aspect of the present invention there is provided an exhaust valve mechanism for a two stroke engine including primary and secondary exhausts. The mechanism includes an actuator slideable along an axis of movement; a primary exhaust valve moveable to at least partially obstruct the primary exhaust, a secondary exhaust valve moveable to at least partially obstruct the secondary exhaust, the primary exhaust valve and the secondary exhaust valve s coupled to the actuator for movement therewith along axes parallel to the axis of movement.
Other aspects and features of the present invention will become apparent to those of ordinary skill in the art, upon review of the following description of specific io embodiments of the invention in conjunction with the accompanying figures.
BRIEF DESCRIPTION OF THE DRAWINGS
In the following figures which illustrate, by way of example only, embodiments is of the invention:
FIG. 1 is a cross sectional view of an exemplary exhaust valve mechanism for a cylinder of a two-cycle engine, exemplary of an embodiment of the present invention, taken through the cylinder axis proximate its exhaust duct;
FIG. 2 is a cross section of FIG. 1 taken along the line II-II;
2o FIG. 3: is a front cross-sectional view of another exemplary exhaust valve mechanism for a two-cycle engine, exemplary of another embodiment of the present invention;
FIG. 4: is a cross-sectional view of yet another exemplary exhaust valve mechanism for a two cycle engine, exemplary of yet a further embodiment of 2s the present invention; and FIGS. 5, 6 are simplified cross-sectional views of additional exemplary exhaust valve mechanisms including alternate exhaust valve drive arrangements.
DETAILED DESCRIPTION
FIG. 1 illustrates a cylinder 1 of a two-cycle engine, exemplary of an s embodiment of the present invention. As illustrated, cylinder 1 includes an exhaust duct 3 contiguous with an engine exhaust port 2. Two side secondary exhausts 4 are symmetrically arranged about primary exhaust port 2. Secondary ducts 5 connect secondary exhausts 4 to exhaust duct 3.
io A wall 6 of exhaust duct 3 that is proximate to the cylinder head also forms a passageway 7 for guiding movement of a primary exhaust valve 8. At its unattached end, primary exhaust valve 8 forms a restricting edge 9 that is matched to the cylinder bore, as best illustrated in FIG. 2. This primary exhaust valve 8 can be moved between a retracted (normal) position and an extended (working) position is along an axis of movement at an acute angle to the axis of cylinder 1. In its working position, the primary exhaust valve 8 is moved forward toward wall 6 of exhaust duct 3, proximate the cylinder head, and thus toward cylinder 1. Primary exhaust valve 8 is biased by a spring 10 towards this working position. To this end, spring 10 (illustrated as a coil spring) bears against a stop surface 11 that is fixed to cylinder 1.
2o By moving primary exhaust valve 8 towards its working position, the axial extent of port 2 is effectively reduced.
Two receiving bores 12 illustrated in FIG. 2 extend parallel to passageway 7 proximate secondary ducts 5. Receiving bores 12, receive secondary exhaust 2s valves 13. Each secondary exhaust valve 13 slides within an associated bore between a normal position that leaves an associated secondary duct 5 unobstructed and a working position that substantially obstructs this secondary duct 5.
Secondary exhaust valves 13 may be formed in numerous ways known to those of ordinary skill in the art. In the preferred embodiment of FIG. 2, secondary exhaust valves 13 are formed as rotationally symmetrical cylinders.
A bridge-like actuating head 14 is provided to move the two secondary s exhaust valves 13. Actuating head 14 is acted upon by a spring 15 in the direction of the working position of the two secondary exhaust valves 13 and may be retracted into its normal position by an actuating drive 16, acting against the force of spring 15. Conveniently, a drive lug 17 extends from the top of each secondary exhaust valve 13 toward primary exhaust valve 8. The valve assembly including primary io exhaust valve 8 includes a complementary pair of lug stops 18.
In operation, actuating drive 16 moves actuating head 14 and thereby secondary exhaust valves 13 between their normal and working positions.
Primary exhaust valve 8, in turn may be retracted into its normal position by drive 16 as lugs 15 17 of secondary exhaust valves 13 move primary exhaust valve 8 by exerting upward force against the lug stops 18. As such, secondary exhaust valves 13 may be moved into their working positions by drive 16 before primary exhaust valve 8 is moved, as driving lugs 17 move along an idle path. Thus, in this embodiment, primary exhaust valve 8 is moved along with secondary exhaust valves 13 only after 2o secondary ducts 5 have been opened by actuating drive 16. Retraction of primary exhaust valve 8 and secondary exhaust valves 13 advantageously opens the cylinder exhaust completely as is desired for peak performance of the engine (FIGS.
1 and 2). Conveniently, a single drive 16 moves both primary exhaust valve 8 and secondary exhaust valves 13 along generally parallel axes.
Of course, primary exhaust valve 8 and secondary exhaust valves 13 could be rigidly coupled to each other through the bridge-like actuating head 14, so that the primary exhaust valve 8 and secondary exhaust valves 13 move in synchronism, and so that there is no relative movement between them. Although simpler, such an s embodiment would likely require primary exhaust valve 13 to extend into wall 6 in its normal position, to allow a delay between closing secondary exhaust valves 13 and primary exhaust valve 8, by allowing for longer actuating travel of secondary exhaust valves 13. This, in turn, would not allow primary exhaust valve 8 to rest flush with s wall 6, thus forming a cavity (not shown) extending into wall 6, which could degrade the performance of the engine.
In the engine of FIGS. 1 and 2, drive 16 may include a conventional pneumatic actuator including a diaphragm cell that accommodates a diaphragm, and io an actuating rod (not shown) as, for example, disclosed in US patent no.
4,399,788.
In alternate embodiments, as for example illustrated in FIG. 3, it is possible to form an exhaust valve mechanism, exemplary of an embodiment of the present invention, having a reduced height. To this end, as illustrated, two secondary is exhaust valves 13' are secured to a common actuating head 14' installed in a housing 20, over a cylindrical stem 21 so as to be able to slide thereon.
Housing 20 includes a guide 22 for cylindrical stem 21. Actuating head 14' and secondary exhaust valves 13' are held in their forward (working) position by two springs 15'. An assembly including primary exhaust valve 8' includes a driving rod slidably mounted 2o in the interior of guide 22, allowing relative movement of primary exhaust valve 8' relative to actuating head 14'. This rod includes lug stops 18'. Actuating head 14' includes complementary lugs 17'. A spring 10' bears against housing 20, and against the top of lug stops 18', biasing primary exhaust valve 8' forward, away from housing 20. A drive 23 further controls the vertical motion of actuating head 14'.
In operation, actuating head 14' and secondary exhaust valves 13' are retracted from their working position toward their normal position by a drive 23 as required. If actuating head 14' is only slightly retracted, primary exhaust valve 8' will initially remain in its working position, biased by spring 10'. If actuating head 14' is retracted far enough, driving lugs 17' of the actuating head 14' after moving along an idle path, will come into contact with the lug stop 18' associated with primary exhaust valve 8'. Thereafter, primary exhaust valve 8' and secondary exhaust valves 13' move in unison with actuating head 14', until the cylinder exhaust is completely s open.
Optionally, as also shown in FIG. 3 primary exhaust valve 8' may be independently driven by a pinion that secured to housing 20 so as to be able to rotate and engage a rack that is attached to the cylindrical stem 21 (the rack and io pinion are indicated by dashed lines in FIG 3). The pinion may be driven by a Bowden-cable and actuator 23, 24 or, alternatively by a servomotor, or the like.
Primary exhaust valve 8' could, of course be pneumatically actuated as, for example, described in connection with FIGS. 1 and 2. As such, the extension of primary exhaust valve 8' relative to the position of secondary exhaust valves 13' is may be adjusted. This in turn allows for control of the relative delay and position between secondary exhaust valves 13' and primary exhaust valve 14', as these move from their normal to working positions.
Other possible drive systems for the primary exhaust valve 8 (or primary 2o exhaust valve 8') and secondary exhaust valves 13 (or 13'), or for the common actuating head 14, are shown in FIGS. 5 and 6. For simplicity, only an exemplary primary exhaust valve 8" (like primary exhaust valve 8 or 8') is shown.
As illustrated, the primary exhaust valve 8" may be coupled to rods installed 2s in a guide bushing 29 (only indicated herein) so as to be able to slide in the direction of the axis of movement 30 of the primary exhaust valve 8". In order to adjust the position of the primary exhaust valve 8" (or an actuating head 14" connected thereto) the shaft of the exhaust valve is provided with a thread 31 (FIG. 5) or with a guide pin 32 (FIG. 6).
to If provided with a thread 31, as illustrated in FIG. 5, thread 31 may engage a threaded bushing 33 that is prevented from motion along the axis of motion of valve 8" yet supported in a guide bushing 29 so as to be able to rotate. As such, when s threaded bushing 33 is rotated, the primary exhaust valve 8" is moved between its working position and normal positions. The threaded bushing 33 can be moved either by a notched belt 34, by gearing, a servo motor, hydraulically, pneumatically, or otherwise.
io Alternatively, in order to allow long travel of primary exhaust valve 8"
with very little rotational movement, an actuating rod of exhaust valve 8" may engage a bushing 35 as illustrated in FIG. 6. As illustrated, bushing 35 includes a guideway machined therein. Pin 32 on the actuating rod of exhaust valve 8" engages the guideway of the bushing 35. Of course, alternatively bushing 35 could be provided is with one or more pins, and a complementary guideway could be formed as part of an actuating rod of primary exhaust valve 8".
A further embodiment allowing the largely independent actuation of primary exhaust valve 8"' (like valves 8, 8', 8") and of secondary exhaust valves 13"' (like 2o valves 13, 13', 13") is illustrated in FIG. 4. As illustrated, primary exhaust valve 8"' and secondary exhaust valves 13"' are once again guided by the cylinder housing.
Secondary exhaust valves 13"' are moved by a guide rod 25 that can slide transversely to the direction of movement of the primary exhaust valve 8"'.
The guide rod 25 is installed either in a housing that is secured to the cylinder, or directly 2s within the cylinder, and is once again moved by a cable, actuator motor, or pneumatically. Guideways 26 are machined into the guide bar 25 and the slides engage in this by way of pins or bolts 27.
a If guide rod 25 is moved in the direction indicated by the arrow 28, primary exhaust valve 8"' and then secondary exhaust valve 13"' are moved toward the cylinder, into their working positions. On subsequent retraction of the guide in the direction opposite that indicated by the arrow 28, first the secondary exhaust valve s 13"' and then the primary exhaust valve 8"' is retracted. Depending on the particular shape (rise, travel) of guideways 26, the primary exhaust valve 8"' and the secondary exhaust valve 13"' can be moved as desired, largely independently of each other. This, in turns, allows great flexibility in timing the primary and the secondary exhaust valves.
to The arrangement described above can be used to particular advantage in multicylinder, in-line engines. In such engines all valves may be operated by a common guide rod 25, greatly reducing the number of engine components.
is The present invention is not, of course, confined to the embodiments shown and described herein. Many modifications are possible. For example, only one secondary exhaust could be provided in place of two such exhausts.
The described drives for the primary exhaust valve 13 (or 13', 13", 13"') and 2o secondary exhaust valves 8 (or 8', 8", 8"') may be extensively modified so that secondary exhaust valves and the primary exhaust valve are actuated in a predetermined dependency on each other. Conveniently, this is simplified as both the primary and secondary exhaust valves are moved along generally parallel axes, in generally the same direction.
Finally, it should be remembered that the primary exhaust valve 8 (or 8', 8", 8"') may also be configured as a double slide (as described in Austrian Patent Document AT 399204) so that the exhaust time can in addition be controlled incrementally.
As such, it will be appreciated that the described embodiments of carrying out the invention are susceptible to many modifications of form, arrangement of parts, details and order of operation. The invention, rather, is intended to encompass all such modification within its scope, as defined by the claims.
In accordance with an aspect of the present invention, there is provided a s two-cycle combustion engine comprising: a combustion cylinder having a cylinder axis; a primary exhaust duct in flow communication with an exhaust port for the cylinder; a secondary exhaust duct in flow communication with the primary exhaust duct; a primary exhaust valve slidably mounted to the cylinder, and moveable along an axis of movement between a normal position and a working position whereat the 1o primary exhaust valve extends into the primary exhaust duct, to partially obstruct the primary exhaust duct; a secondary exhaust valve, moveable along an axis of movement generally parallel to the axis of movement of the primary exhaust valve, between a normal position and a working position whereat the secondary exhaust valve at least partially obstructs the secondary exhaust duct. A drive operably is connects the primary exhaust valve and the secondary exhaust valve to move the primary exhaust valve and the secondary exhaust valves between their normal and working positions.
In accordance with another aspect of the present invention there is provided a 2o method of controlling the exhaust flow of a two-cycle engine comprising a cylinder having primary and secondary exhaust ducts associated therewith. The method includes driving an actuator to sequentially extend a secondary exhaust valve along an axis of movement to at least partially obstruct flow through the secondary exhaust duct, and thereafter extend a primary exhaust valve along an axis parallel to the axis 2s of movement of the secondary exhaust valve to obstruct flow through the primary exhaust duct.
In accordance with a further aspect of the present invention there is provided an exhaust valve mechanism for a two stroke engine including primary and secondary exhausts. The mechanism includes an actuator slideable along an axis of movement; a primary exhaust valve moveable to at least partially obstruct the primary exhaust, a secondary exhaust valve moveable to at least partially obstruct the secondary exhaust, the primary exhaust valve and the secondary exhaust valve s coupled to the actuator for movement therewith along axes parallel to the axis of movement.
Other aspects and features of the present invention will become apparent to those of ordinary skill in the art, upon review of the following description of specific io embodiments of the invention in conjunction with the accompanying figures.
BRIEF DESCRIPTION OF THE DRAWINGS
In the following figures which illustrate, by way of example only, embodiments is of the invention:
FIG. 1 is a cross sectional view of an exemplary exhaust valve mechanism for a cylinder of a two-cycle engine, exemplary of an embodiment of the present invention, taken through the cylinder axis proximate its exhaust duct;
FIG. 2 is a cross section of FIG. 1 taken along the line II-II;
2o FIG. 3: is a front cross-sectional view of another exemplary exhaust valve mechanism for a two-cycle engine, exemplary of another embodiment of the present invention;
FIG. 4: is a cross-sectional view of yet another exemplary exhaust valve mechanism for a two cycle engine, exemplary of yet a further embodiment of 2s the present invention; and FIGS. 5, 6 are simplified cross-sectional views of additional exemplary exhaust valve mechanisms including alternate exhaust valve drive arrangements.
DETAILED DESCRIPTION
FIG. 1 illustrates a cylinder 1 of a two-cycle engine, exemplary of an s embodiment of the present invention. As illustrated, cylinder 1 includes an exhaust duct 3 contiguous with an engine exhaust port 2. Two side secondary exhausts 4 are symmetrically arranged about primary exhaust port 2. Secondary ducts 5 connect secondary exhausts 4 to exhaust duct 3.
io A wall 6 of exhaust duct 3 that is proximate to the cylinder head also forms a passageway 7 for guiding movement of a primary exhaust valve 8. At its unattached end, primary exhaust valve 8 forms a restricting edge 9 that is matched to the cylinder bore, as best illustrated in FIG. 2. This primary exhaust valve 8 can be moved between a retracted (normal) position and an extended (working) position is along an axis of movement at an acute angle to the axis of cylinder 1. In its working position, the primary exhaust valve 8 is moved forward toward wall 6 of exhaust duct 3, proximate the cylinder head, and thus toward cylinder 1. Primary exhaust valve 8 is biased by a spring 10 towards this working position. To this end, spring 10 (illustrated as a coil spring) bears against a stop surface 11 that is fixed to cylinder 1.
2o By moving primary exhaust valve 8 towards its working position, the axial extent of port 2 is effectively reduced.
Two receiving bores 12 illustrated in FIG. 2 extend parallel to passageway 7 proximate secondary ducts 5. Receiving bores 12, receive secondary exhaust 2s valves 13. Each secondary exhaust valve 13 slides within an associated bore between a normal position that leaves an associated secondary duct 5 unobstructed and a working position that substantially obstructs this secondary duct 5.
Secondary exhaust valves 13 may be formed in numerous ways known to those of ordinary skill in the art. In the preferred embodiment of FIG. 2, secondary exhaust valves 13 are formed as rotationally symmetrical cylinders.
A bridge-like actuating head 14 is provided to move the two secondary s exhaust valves 13. Actuating head 14 is acted upon by a spring 15 in the direction of the working position of the two secondary exhaust valves 13 and may be retracted into its normal position by an actuating drive 16, acting against the force of spring 15. Conveniently, a drive lug 17 extends from the top of each secondary exhaust valve 13 toward primary exhaust valve 8. The valve assembly including primary io exhaust valve 8 includes a complementary pair of lug stops 18.
In operation, actuating drive 16 moves actuating head 14 and thereby secondary exhaust valves 13 between their normal and working positions.
Primary exhaust valve 8, in turn may be retracted into its normal position by drive 16 as lugs 15 17 of secondary exhaust valves 13 move primary exhaust valve 8 by exerting upward force against the lug stops 18. As such, secondary exhaust valves 13 may be moved into their working positions by drive 16 before primary exhaust valve 8 is moved, as driving lugs 17 move along an idle path. Thus, in this embodiment, primary exhaust valve 8 is moved along with secondary exhaust valves 13 only after 2o secondary ducts 5 have been opened by actuating drive 16. Retraction of primary exhaust valve 8 and secondary exhaust valves 13 advantageously opens the cylinder exhaust completely as is desired for peak performance of the engine (FIGS.
1 and 2). Conveniently, a single drive 16 moves both primary exhaust valve 8 and secondary exhaust valves 13 along generally parallel axes.
Of course, primary exhaust valve 8 and secondary exhaust valves 13 could be rigidly coupled to each other through the bridge-like actuating head 14, so that the primary exhaust valve 8 and secondary exhaust valves 13 move in synchronism, and so that there is no relative movement between them. Although simpler, such an s embodiment would likely require primary exhaust valve 13 to extend into wall 6 in its normal position, to allow a delay between closing secondary exhaust valves 13 and primary exhaust valve 8, by allowing for longer actuating travel of secondary exhaust valves 13. This, in turn, would not allow primary exhaust valve 8 to rest flush with s wall 6, thus forming a cavity (not shown) extending into wall 6, which could degrade the performance of the engine.
In the engine of FIGS. 1 and 2, drive 16 may include a conventional pneumatic actuator including a diaphragm cell that accommodates a diaphragm, and io an actuating rod (not shown) as, for example, disclosed in US patent no.
4,399,788.
In alternate embodiments, as for example illustrated in FIG. 3, it is possible to form an exhaust valve mechanism, exemplary of an embodiment of the present invention, having a reduced height. To this end, as illustrated, two secondary is exhaust valves 13' are secured to a common actuating head 14' installed in a housing 20, over a cylindrical stem 21 so as to be able to slide thereon.
Housing 20 includes a guide 22 for cylindrical stem 21. Actuating head 14' and secondary exhaust valves 13' are held in their forward (working) position by two springs 15'. An assembly including primary exhaust valve 8' includes a driving rod slidably mounted 2o in the interior of guide 22, allowing relative movement of primary exhaust valve 8' relative to actuating head 14'. This rod includes lug stops 18'. Actuating head 14' includes complementary lugs 17'. A spring 10' bears against housing 20, and against the top of lug stops 18', biasing primary exhaust valve 8' forward, away from housing 20. A drive 23 further controls the vertical motion of actuating head 14'.
In operation, actuating head 14' and secondary exhaust valves 13' are retracted from their working position toward their normal position by a drive 23 as required. If actuating head 14' is only slightly retracted, primary exhaust valve 8' will initially remain in its working position, biased by spring 10'. If actuating head 14' is retracted far enough, driving lugs 17' of the actuating head 14' after moving along an idle path, will come into contact with the lug stop 18' associated with primary exhaust valve 8'. Thereafter, primary exhaust valve 8' and secondary exhaust valves 13' move in unison with actuating head 14', until the cylinder exhaust is completely s open.
Optionally, as also shown in FIG. 3 primary exhaust valve 8' may be independently driven by a pinion that secured to housing 20 so as to be able to rotate and engage a rack that is attached to the cylindrical stem 21 (the rack and io pinion are indicated by dashed lines in FIG 3). The pinion may be driven by a Bowden-cable and actuator 23, 24 or, alternatively by a servomotor, or the like.
Primary exhaust valve 8' could, of course be pneumatically actuated as, for example, described in connection with FIGS. 1 and 2. As such, the extension of primary exhaust valve 8' relative to the position of secondary exhaust valves 13' is may be adjusted. This in turn allows for control of the relative delay and position between secondary exhaust valves 13' and primary exhaust valve 14', as these move from their normal to working positions.
Other possible drive systems for the primary exhaust valve 8 (or primary 2o exhaust valve 8') and secondary exhaust valves 13 (or 13'), or for the common actuating head 14, are shown in FIGS. 5 and 6. For simplicity, only an exemplary primary exhaust valve 8" (like primary exhaust valve 8 or 8') is shown.
As illustrated, the primary exhaust valve 8" may be coupled to rods installed 2s in a guide bushing 29 (only indicated herein) so as to be able to slide in the direction of the axis of movement 30 of the primary exhaust valve 8". In order to adjust the position of the primary exhaust valve 8" (or an actuating head 14" connected thereto) the shaft of the exhaust valve is provided with a thread 31 (FIG. 5) or with a guide pin 32 (FIG. 6).
to If provided with a thread 31, as illustrated in FIG. 5, thread 31 may engage a threaded bushing 33 that is prevented from motion along the axis of motion of valve 8" yet supported in a guide bushing 29 so as to be able to rotate. As such, when s threaded bushing 33 is rotated, the primary exhaust valve 8" is moved between its working position and normal positions. The threaded bushing 33 can be moved either by a notched belt 34, by gearing, a servo motor, hydraulically, pneumatically, or otherwise.
io Alternatively, in order to allow long travel of primary exhaust valve 8"
with very little rotational movement, an actuating rod of exhaust valve 8" may engage a bushing 35 as illustrated in FIG. 6. As illustrated, bushing 35 includes a guideway machined therein. Pin 32 on the actuating rod of exhaust valve 8" engages the guideway of the bushing 35. Of course, alternatively bushing 35 could be provided is with one or more pins, and a complementary guideway could be formed as part of an actuating rod of primary exhaust valve 8".
A further embodiment allowing the largely independent actuation of primary exhaust valve 8"' (like valves 8, 8', 8") and of secondary exhaust valves 13"' (like 2o valves 13, 13', 13") is illustrated in FIG. 4. As illustrated, primary exhaust valve 8"' and secondary exhaust valves 13"' are once again guided by the cylinder housing.
Secondary exhaust valves 13"' are moved by a guide rod 25 that can slide transversely to the direction of movement of the primary exhaust valve 8"'.
The guide rod 25 is installed either in a housing that is secured to the cylinder, or directly 2s within the cylinder, and is once again moved by a cable, actuator motor, or pneumatically. Guideways 26 are machined into the guide bar 25 and the slides engage in this by way of pins or bolts 27.
a If guide rod 25 is moved in the direction indicated by the arrow 28, primary exhaust valve 8"' and then secondary exhaust valve 13"' are moved toward the cylinder, into their working positions. On subsequent retraction of the guide in the direction opposite that indicated by the arrow 28, first the secondary exhaust valve s 13"' and then the primary exhaust valve 8"' is retracted. Depending on the particular shape (rise, travel) of guideways 26, the primary exhaust valve 8"' and the secondary exhaust valve 13"' can be moved as desired, largely independently of each other. This, in turns, allows great flexibility in timing the primary and the secondary exhaust valves.
to The arrangement described above can be used to particular advantage in multicylinder, in-line engines. In such engines all valves may be operated by a common guide rod 25, greatly reducing the number of engine components.
is The present invention is not, of course, confined to the embodiments shown and described herein. Many modifications are possible. For example, only one secondary exhaust could be provided in place of two such exhausts.
The described drives for the primary exhaust valve 13 (or 13', 13", 13"') and 2o secondary exhaust valves 8 (or 8', 8", 8"') may be extensively modified so that secondary exhaust valves and the primary exhaust valve are actuated in a predetermined dependency on each other. Conveniently, this is simplified as both the primary and secondary exhaust valves are moved along generally parallel axes, in generally the same direction.
Finally, it should be remembered that the primary exhaust valve 8 (or 8', 8", 8"') may also be configured as a double slide (as described in Austrian Patent Document AT 399204) so that the exhaust time can in addition be controlled incrementally.
As such, it will be appreciated that the described embodiments of carrying out the invention are susceptible to many modifications of form, arrangement of parts, details and order of operation. The invention, rather, is intended to encompass all such modification within its scope, as defined by the claims.
Claims (16)
1. A two-cycle combustion engine comprising:
a combustion cylinder having a cylinder axis;
a primary exhaust duct in flow communication with an exhaust port for said cylinder;
a secondary exhaust duct in flow communication with said primary exhaust duct;
a primary exhaust valve slidably mounted to said cylinder, and moveable along an axis of movement between a normal position and a working position whereat said primary exhaust valve extends into said primary exhaust duct, to partially obstruct said primary exhaust duct;
a secondary exhaust valve, moveable along an axis of movement generally parallel to said axis of movement of said primary exhaust valve, between a normal position and a working position whereat said secondary exhaust valve at least partially obstructs said secondary exhaust duct;
a drive operably connected to said primary exhaust valve and said secondary exhaust valve to move said primary exhaust valve and said secondary exhaust valves between their normal and working positions.
a combustion cylinder having a cylinder axis;
a primary exhaust duct in flow communication with an exhaust port for said cylinder;
a secondary exhaust duct in flow communication with said primary exhaust duct;
a primary exhaust valve slidably mounted to said cylinder, and moveable along an axis of movement between a normal position and a working position whereat said primary exhaust valve extends into said primary exhaust duct, to partially obstruct said primary exhaust duct;
a secondary exhaust valve, moveable along an axis of movement generally parallel to said axis of movement of said primary exhaust valve, between a normal position and a working position whereat said secondary exhaust valve at least partially obstructs said secondary exhaust duct;
a drive operably connected to said primary exhaust valve and said secondary exhaust valve to move said primary exhaust valve and said secondary exhaust valves between their normal and working positions.
2. The engine of claim 1, wherein said axis of movement of said primary exhaust valve extends at an acute angle to said cylinder axis.
3. The engine of claim 2, wherein said primary exhaust valve in its working position reduces the axial extent of said exhaust port.
4. The engine of claim 1, further comprising an actuating head coupled to said drive, said primary exhaust valve and said secondary exhaust valve.
5. The engine of claim 4, further comprising a spring biasing said actuating head.
6. The engine of any one of claims 1 to 4, wherein said secondary exhaust valve is slidable relative to said primary exhaust for independent movement of said secondary exhaust valve.
7. The engine of claim 5, wherein movement of said secondary exhaust valve relative to said primary exhaust valve is limited by a stopping surface on at least one of said primary exhaust valve and said secondary exhaust valve.
8. The engine of claim 3, further comprising independent first and second springs respectively biasing said primary exhaust valve and said secondary exhaust valve toward their working positions.
9. The engine of claim 3, 4 or 5 wherein said drive comprises a pneumatic drive operatively connected to said actuating head.
10.The engine of claim 3, 4 or 5 wherein said drive comprises a rack and pinion operatively connected to said actuating head.
11.The engine of claim 3, 4 or 5 wherein said drive comprises a threaded bushing operatively connected to said actuating head.
12.The engine of claim 3, 4 or 5 wherein said drive comprises a bushing having a guide machined therein.
13.The engine of claim 3, 4 or 5 wherein said drive comprises a guide rod moveable along an axis of motion, said guide rod comprising first and second pin guides, extending parallel and transverse to said axis of motion, said first and second pin guides engaging first and second guide pins extending from said primary exhaust valve and said secondary exhaust valve, respectively, to move said primary exhaust valve and said secondary exhaust valve between their normal and working positions as said guide rod is moved along its axis of motion.
14.A method of controlling the exhaust flow of a two-cycle engine comprising a cylinder having primary and secondary exhaust ducts associated therewith, said method comprising:
driving an actuator to sequentially extend a secondary exhaust valve along an axis of movement to at least partially obstruct flow through said secondary exhaust duct, and thereafter extend a primary exhaust valve along an axis parallel to said axis of movement of said secondary exhaust valve to obstruct flow through said primary exhaust duct.
driving an actuator to sequentially extend a secondary exhaust valve along an axis of movement to at least partially obstruct flow through said secondary exhaust duct, and thereafter extend a primary exhaust valve along an axis parallel to said axis of movement of said secondary exhaust valve to obstruct flow through said primary exhaust duct.
15. The method of claim 14, wherein said axis of movement is at an acute angle to an axis of said cylinder.
16. An exhaust valve mechanism for a two cycle engine comprising primary and secondary exhausts, said mechanism comprising:
an actuator slideable along an axis of movement;
a primary exhaust valve moveable to at least partially obstruct said primary exhaust, a secondary exhaust valve moveable to at least partially obstruct said secondary exhaust, said primary exhaust valve and said secondary exhaust valve coupled to said actuator for movement therewith along axes parallel to said axis of movement.
an actuator slideable along an axis of movement;
a primary exhaust valve moveable to at least partially obstruct said primary exhaust, a secondary exhaust valve moveable to at least partially obstruct said secondary exhaust, said primary exhaust valve and said secondary exhaust valve coupled to said actuator for movement therewith along axes parallel to said axis of movement.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA002355038A CA2355038A1 (en) | 2001-08-14 | 2001-08-14 | Two-cycle engine including improved exhaust valve mechanism, and method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA002355038A CA2355038A1 (en) | 2001-08-14 | 2001-08-14 | Two-cycle engine including improved exhaust valve mechanism, and method |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2355038A1 true CA2355038A1 (en) | 2003-02-14 |
Family
ID=4169727
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002355038A Abandoned CA2355038A1 (en) | 2001-08-14 | 2001-08-14 | Two-cycle engine including improved exhaust valve mechanism, and method |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA2355038A1 (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7213544B2 (en) | 2004-01-30 | 2007-05-08 | Brp-Rotax Gmbh & Co. Kg | Exhaust-outlet control for 2-stroke engine |
| EP1988270A1 (en) | 2007-05-02 | 2008-11-05 | KTM Sportmotorcycle AG | Two-stroke internal combustion engine |
-
2001
- 2001-08-14 CA CA002355038A patent/CA2355038A1/en not_active Abandoned
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7213544B2 (en) | 2004-01-30 | 2007-05-08 | Brp-Rotax Gmbh & Co. Kg | Exhaust-outlet control for 2-stroke engine |
| EP1988270A1 (en) | 2007-05-02 | 2008-11-05 | KTM Sportmotorcycle AG | Two-stroke internal combustion engine |
| DE102007020579A1 (en) | 2007-05-02 | 2008-11-06 | Ktm-Sportmotorcycle Ag | Two-stroke internal combustion engine |
| US8201526B2 (en) | 2007-05-02 | 2012-06-19 | KTM Sportmotorcycle, AG | Two-stroke internal combustion engine |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US7213544B2 (en) | Exhaust-outlet control for 2-stroke engine | |
| CA2491723C (en) | Valve-operating system for internal combustion engine | |
| US4621596A (en) | Exhaust control system | |
| ITTO980156A1 (en) | INTERNAL COMBUSTION ENGINE WITH VARIABLE OPERATION VALVES. | |
| JPH03130509A (en) | Valve actuating device of engine | |
| US5016581A (en) | Valve mechanisms | |
| US6644255B1 (en) | Guide plate for a poppet valve | |
| CA2355038A1 (en) | Two-cycle engine including improved exhaust valve mechanism, and method | |
| US5752476A (en) | Exhaust controller for two-stroke-cycle engine | |
| DK200001075A (en) | Method for activating an exhaust valve for an internal combustion engine and such an exhaust valve | |
| EP0604699B1 (en) | Exhaust timing controller for two-stroke cycle engine | |
| US6886513B2 (en) | Valve mechanism comprising a variable cross-section of a valve opening | |
| EP0324092A1 (en) | Valve actuation device for multi-valve-type engine | |
| JP3434084B2 (en) | Exhaust timing control structure for two-cycle engine | |
| JP3313376B2 (en) | Exhaust control device for two-stroke engine | |
| KR960013355B1 (en) | Suction & exhaust valve variable opening apparatus for a car | |
| JPH05321673A (en) | Exhaust device for two-cycle engine | |
| KR960013353B1 (en) | Suction & exhaust valve variable opening apparatus | |
| JP3887392B2 (en) | Valve operating device for internal combustion engine | |
| JP3557452B2 (en) | Exhaust timing control device for two-stroke engine | |
| KR960013354B1 (en) | Suction & exhaust valve variable opening apparatus | |
| JPS6224917Y2 (en) | ||
| JPH06117209A (en) | Valve system for internal combustion engine | |
| JPH0351886B2 (en) | ||
| GB2228536A (en) | Two stroke engine exhaust port control |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| EEER | Examination request | ||
| FZDE | Discontinued | ||
| FZDE | Discontinued |
Effective date: 20100226 |