JP4372481B2 - Motorcycle engine and motorcycle equipped with the engine - Google Patents

Description

  The present invention relates to an engine for a motorcycle capable of maintaining good operability of a clutch, and a motorcycle equipped with the engine.

  An engine mounted on a motorcycle mainly includes an upper cylinder, a lower crankcase, and an oil pan at the bottom of the crankcase. A crank chamber for storing the crankshaft and a clutch chamber for storing the clutch are provided in the crankcase. A handle of the motorcycle is provided with a clutch lever, and an operator can disengage the clutch or connect the clutch by operating the clutch lever.

  In such an engine, oil (engine oil) used for lubrication and cooling is circulated through various places in the engine. One form of circulating oil in the engine is a dry sump type (see Patent Document 1).

  Dry sump engines are equipped with an oil pump (scavenging pump) for collecting the oil in the oil pan to the oil tank and an oil pump (feed pump) for pumping the oil in the oil tank to various parts of the engine. ing. Both the scavenging pump and the feed pump are driven by engine operation (crankshaft rotation).

  In the case of a four-stroke engine, a part of the oil pumped by the feed pump is sent to the cylinder head and serves to lubricate the valve train. After that, the oil that has been used for lubrication is collected in an oil pan. The oil collected in the oil pan is sucked up by a scavenging pump through a scavenge mouth provided in the oil pan and collected in an oil tank provided separately from the oil pan. The oil in the oil tank is pumped to a cylinder head or the like by a feed pump, and again used for lubrication and cooling.

In such a dry sump engine, oil collected in the oil pan is collected in an oil tank by a scavenging pump, so that a large amount of oil is not stored in the oil pan.
Japanese Patent Laid-Open No. 2003-14094

  By the way, depending on the structure of the engine, the oil returning from the cylinder head to the oil pan may be forced to pass through the clutch chamber. In this case, the oil level in the clutch chamber becomes high, and the clutch is easily immersed in oil. As a result, the viscous resistance of the oil may affect the operability of the clutch.

  For example, when the engine that was operating is stopped, the oil sent to the cylinder head descends and is collected in the clutch chamber, but is collected because the engine is stopped and the scavenging pump is not operating. The accumulated oil is not collected in the oil tank but accumulated in the inner bottom of the clutch chamber. Therefore, the clutch may be immersed in the accumulated oil, and the operability may be affected.

  In the case of an engine in which a clutch chamber is disposed on the same side as the side stand with respect to the vehicle body, the vehicle body is tilted so that the clutch chamber is lowered when supported by the side stand. Accordingly, the oil accumulated in the oil pan or the oil descending from the cylinder head as described above may enter the clutch chamber and the oil level in the clutch chamber may increase, which affects the operability of the clutch.

  Accordingly, the present invention provides an engine for a motorcycle that prevents oil from accumulating in the clutch chamber, prevents the clutch from being immersed in oil after the engine is stopped, and maintains good operability of the clutch. And a motorcycle equipped with the engine.

  The present invention has been made in view of the above-described circumstances, and a motorcycle engine according to the present invention includes a crank chamber that houses a crankshaft and has an oil pan at a lower portion thereof, and is disposed adjacent to the crank chamber. A clutch chamber for accommodating the clutch, and a partition wall for partitioning the crank chamber and the clutch chamber, and an oil passage for guiding oil to the oil pan is formed in the partition wall.

  In such a configuration, the oil flowing down from the cylinder head can be guided to the oil pan through the oil passage formed in the wall constituting the clutch chamber, so that the oil does not collect in the clutch chamber and the clutch is It is possible to prevent oil soaking.

  In addition, an oil inlet through which oil flowing into the clutch chamber passes and an oil outlet through which oil flows out from the clutch chamber to the oil pan are formed in the partition wall. An oil inflow passage leading to the inflow port and an oil outflow passage leading to the oil outflow port are formed. In the clutch chamber, the oil flowing in from the oil inflow port is prevented from scattering, and the oil is sent to the oil outflow port. In order to guide, a cover may be provided to cover the oil inlet.

  In such a configuration, for example, when oil flows down from the cylinder head, the oil flowing in from the oil inlet is blocked by the cover even if the engine structure has to pass through the clutch chamber. Therefore, the oil can be smoothly guided to the oil outlet without being scattered into the clutch chamber. Therefore, oil flowing down from the cylinder head after the engine is stopped can be guided to the oil pan without accumulating in the inner bottom portion of the clutch chamber, and the clutch can be prevented from being immersed in oil.

  In addition, a recess may be formed in the partition wall, the oil inlet and the oil outlet may be formed at the back of the recess, and the cover may be provided by closing the opening of the recess. In such a configuration, a closed space (oil return chamber) having an oil inlet and an oil outlet is formed by the recess and the cover. Therefore, the oil flowing in from the oil inlet is unlikely to leak from the space into the clutch chamber, and can be more reliably guided to the oil pan through the oil outlet.

  The cover may have a weight shape and may be provided so as to protrude to the back side of the recess. In such a configuration, the oil flowing in from the oil inlet rebounds on the surface of the cover and is easily guided to the back side of the recess. Accordingly, oil is more difficult to leak from the space formed by the recess and the cover to the clutch chamber.

  The cover may be made of metal, and a generator for power generation may be provided close to the cover in the clutch chamber. In such a configuration, heat generated by the generator is transferred to the cover and radiated. The heat transmitted to the cover is also taken away by the oil that has come into contact with the cover. Therefore, it is possible to cool the generator that becomes relatively hot during power generation.

  As a more specific configuration example, an end of the crankshaft penetrates the recess and the cover and protrudes into the clutch chamber, and a rotor of a generator for power generation is formed at the end. The cover may be made of metal, and the generator stator may be provided close to the cover. In such a configuration, the generator and the cover can be disposed relatively easily and heat dissipation and cooling of the generator can be promoted through the cover.

  In addition, between the crank chamber and the clutch chamber, the partition wall restricts the flow of oil between the bottom portions, and sucks the oil accumulated in the inner bottom portions of the crank chamber and the clutch chamber. A scavenging pump may be provided.

  In such a configuration, since the crank chamber and the clutch chamber are partitioned by a partition wall, even if the engine is tilted, the oil accumulated in the inner bottom portion of the crank chamber does not flow into the clutch chamber, and the clutch Can be prevented from being soaked in oil.

  The clutch chamber may be disposed on the same side as the side stand with respect to the vehicle body with respect to the crank chamber. In such a configuration, even if the vehicle body is tilted by supporting the vehicle body with the side stand and the clutch chamber is positioned below the crank chamber, the oil accumulated in the inner bottom of the crank chamber is retained. Intrusion into the crank chamber can be prevented.

  In addition, when the above-described engine is mounted on a motorcycle, it is possible to realize a motorcycle in which the clutch of the engine is not easily immersed in oil, and the clutch operation can be smoothly performed at the time of shifting.

  According to the present invention, for a motorcycle, oil can be prevented from accumulating in the clutch chamber, and the clutch can be kept oil-free after the engine is stopped, and the operability of the clutch can be maintained satisfactorily. An engine and a motorcycle equipped with the engine can be provided.

  Hereinafter, a motorcycle engine according to an embodiment of the present invention and a motorcycle equipped with the engine will be specifically described with reference to the drawings. FIG. 1 is a left side view of the motorcycle. A motorcycle 1 shown in FIG. 1 is an American type, and includes a frame 4 that forms a skeleton of a vehicle body between a front wheel 2 and a rear wheel 3, and an engine E is mounted in the frame 4. The engine E is fixed to the frame 4 via a plurality of brackets. A side stand 5 is provided on the left side of the frame 4. In the following description of the present embodiment, description will be made based on directions (front and rear, left and right, and up and down) related to the motorcycle 1 shown in FIG.

  2 is a left side view of the engine E with a part cut away, and FIG. 3 is a right side view of the engine E with a part cut out. The engine E is a V-type two-cylinder four-cycle engine, and cylinders 6 and 7 are arranged in a V shape so as to incline forward and backward, and a crank provided below the cylinders 6 and 7. A case 8 and an oil pan 9 provided below the crankcase 8 are provided. Further, the cylinders 6 and 7 have cylinder heads 6a and 7a at their upper portions, and have valve operating systems such as valves and rocker shafts therein.

[Main housing]
FIG. 4 is an exploded perspective view showing the main housing parts of the engine E excluding the cylinders 6 and 7. As shown in FIG. 4, the engine E includes a left crankcase 10 and a right crankcase 11 that are paired on the left and right. When the left crankcase 10 and the right crankcase 11 are closed from the left and right to form a crankcase 8, a crank chamber 20, a transmission chamber 21, an output shaft chamber 22, and a separator chamber 23 are contained in the crankcase 8. It is formed.

  The left side portion (outer side portion) of the left crankcase 10 is recessed toward the right side (center side) to form a part of the clutch chamber 24. An inner clutch cover 12 is attached to the left crankcase 10 from the left side and the peripheral portions thereof are joined to each other, and an outer clutch cover 13 is attached to the left side portion of the inner clutch cover 12. An inner clutch cover 12 is joined to the left crankcase 10, and an outer clutch cover 13 is joined to the inner clutch cover 12, whereby a clutch chamber 24 is formed inside the cover.

  A cam cover 14 is attached to the front side of the right side (outer side) of the right crankcase 11. A space between the right crankcase 11 and the cam cover 14 forms a cam chamber 25, in which a cam, a cam chain, and the like to be described later are housed. Further, an inner mission cover 15 is attached to a position near the right side of the right crankcase 11, and an outer mission cover 17 is attached to the right side of the inner mission cover 15. An internal space formed by the inner mission cover 15 and the outer mission cover 17 forms an oil storage chamber 26.

  An oil pan 9 is attached to the lower part of the left crankcase 10 and the right crankcase 11. As a result, the oil pan 9 is located below the crank chamber 20 and the transmission chamber 21.

  In addition, although not shown in figure, the sealing member is interposed between each member mentioned above, and gas and a liquid do not leak from the connection location between each member.

  FIG. 5 is a VV cross-sectional view of the engine E shown in FIG. As shown in FIG. 5, in the engine E, the crank chamber 20 is located below the cylinders 6 and 7, and a transmission chamber 21 is disposed behind the crank chamber 20. The transmission chamber 21 is also used as an oil tank.

  An output shaft chamber 22 is disposed behind the transmission chamber 21, and a right side portion of the transmission chamber 21 extends rearward along the right side portion of the output shaft chamber 22. A separator chamber 23 is disposed behind the output shaft chamber 22. Further, a clutch chamber 24 is disposed on the left side of the engine E and on the left side of the crank chamber 20 and the transmission chamber 21, and an oil storage chamber 26 is disposed on the right side of the engine E and on the right side of the transmission chamber 21. Has been placed.

  The crank chamber 20, the transmission chamber 21, the output shaft chamber 22, the separator chamber 23, and the clutch chamber 24 are integrally formed by a crank case 8 formed by closing the left crank case 10 and the right crank case 11. .

  Since the engine E formed integrally in this way can reduce the number of parts compared to the case where the transmission chamber 21, the output shaft chamber 22, and the separator chamber 23 are configured separately from the crank chamber 20, Engine weight and assembly man-hours can also be reduced. Further, the engine E can be made compact.

[Power transmission structure]
As shown in FIG. 5, a crankshaft 30 is accommodated in the crank chamber 20. Each of the left crankcase 10 and the right crankcase 11 is provided with a bearing portion 30a, and the crankshaft 30 is rotatably supported by the bearing portion 30a so that the shaft core faces in the left-right direction. A piston 33 is connected to the crankpin 31 of the crankshaft 30 via a connecting rod 32. The piston 33 reciprocates substantially vertically along the inner wall surfaces of the cylinders 6 and 7 in conjunction with the rotation of the crankshaft 30.

  The right end portion of the crankshaft 30 penetrates the right crankcase 11 and protrudes into the cam chamber 25, and is connected to the cam sprockets 34 and 35 via a chain (see FIG. 3). Further, the right end portion of the crankshaft 30 is also connected to balancer shafts 36 and 37 disposed before and after the crankshaft 30 via a chain (see FIG. 3).

  The balancer shafts 36 and 37 are arranged in parallel to the crankshaft 30, and weights are provided on the shaft (not shown). The balancer shafts 36 and 37 rotate with the rotation of the crankshaft 30 to suppress vibration of the engine E itself caused by the operation of the engine E. As will be described later, the balancer shaft 37 disposed on the rear side drives an oil pump (see oil pump 90 in FIG. 12) for pumping or sucking up oil circulating in the engine E.

  As shown in FIG. 5, a partition wall 38 formed in the left crankcase 10 is provided between the crank chamber 20 and the clutch chamber 24 to partition both chambers. The bearing portion 30a described above is provided through the partition wall 38. The left end portion of the crankshaft 30 passes through a bearing portion 30a provided in the partition wall 38 and a cover 39 which will be described later and protrudes into the clutch chamber 24, and a generator 40 for power generation is provided at the left end portion. Yes.

  A main shaft 41 and a counter shaft 42 are rotatably supported in the transmission chamber 21 such that the shaft core is parallel to the crankshaft 30. The main shaft 41 and the counter shaft 42 are hollow tubular, and an oil passage 43 is formed inside thereof. A left end portion of the main shaft 41 passes through a partition wall 44 that partitions the transmission chamber 21 and the clutch chamber 24 and protrudes into the clutch chamber 24, and a clutch 45 is provided at the left end portion.

  The crankshaft 30 and the main shaft 41 are connected to each other in the clutch chamber 24 through sprockets 30b and 41b and a chain 41a. When the clutch 45 is engaged, the rotational force of the crankshaft 30 is transmitted to the main shaft 41 via the sprockets 30b and 41b and the chain 41a. When the clutch 45 is disengaged, the rotation of the crankshaft 30 is performed. The force is not transmitted to the main shaft 41.

  The right end portions of the main shaft 41 and the countershaft 42 penetrate the inner mission cover 15, and an oil passage 43 formed in each shaft opens in the oil storage chamber 26. Therefore, the oil storage chamber 26 and the respective oil passages 43 in the main shaft 41 and the counter shaft 42 communicate with each other.

  The main shaft 41 and the counter shaft 42 are provided with a transmission 46 composed of a plurality of gears 46a having different diameters. When an operator operates a change lever (not shown), a predetermined gear 46a of the main shaft 41 and a counter shaft 42 is engaged with a predetermined gear 46a. In addition, a plurality of oil injection holes 47 are provided at the base positions of the plurality of gears 46 a forming the transmission 46 so as to penetrate the peripheral portions of the main shaft 41 and the counter shaft 42 to the internal oil passage 43.

  An output shaft 48 is rotatably supported in the output shaft chamber 22 such that the axis is parallel to the counter shaft 42. The right end portion of the output shaft 48 protrudes from the output shaft chamber 22 to the transmission chamber 21. Gears that mesh with each other are provided at the right end portion of the output shaft 48 and the right end portion of the counter shaft 42, respectively, and the rotational force of the counter shaft 42 is transmitted to the output shaft 48 via the gears.

  The left end portion of the output shaft 48 protrudes from the output shaft chamber 22 to the left side of the left crankcase 10, and a pulley 49 is provided at the left end portion. A belt is stretched between the pulley 49 and the shaft of the rear wheel 3 (see FIG. 1) of the motorcycle 1 so that the rotational force of the output shaft 48 is transmitted to the rear wheel 3. .

[Clutch room]
6 is a left side view partially showing the left crankcase 10 constituting the clutch chamber 24, and FIG. 7 is a cross-sectional view taken along the arrow VII-VII of the left crankcase 10 shown in FIG. As shown in FIGS. 6 and 7, around the bearing portion 30a provided on the left crankcase 10, an annular projecting portion 50 is provided concentrically with the bearing portion 30a so as to project toward the clutch chamber 24 side. An annular recess 51 is formed on the inner diameter side of the protrusion 50.

  Oil inlets 52 and 53 are formed in the upper part of the inner surface of the recess 51, and oil inlets (oil passages) 54 and 55 are passed upward from the oil inlets 52 and 53 through the partition wall 38. Is extended. The oil inflow passages 54 and 55 are opened at the upper end of the left crankcase 10 so that the oil from the cylinder heads 6a and 7a above the cylinders 6 and 7 (see FIG. 1) flows. It communicates with oil pipes 56 and 57 provided on the left side of.

  Oil outlets 60 and 61 are formed in the lower part of the inner surface of the recess 51, and oil outlets (oil passages) 62 and 63 pass downward from the oil outlets 60 and 61 through the partition wall 38. Is extended. The oil outflow passages 62 and 63 open toward the oil pan 9 (see FIG. 4) at the lower end of the left crankcase 10.

  As shown in FIG. 6, a plurality of (seven in FIG. 6) vent holes 66 are provided in the partition wall 38 outside the protruding portion 50. As shown in FIG. 7, the vent hole 66 passes through the partition wall 38 and communicates between the crank chamber 20 and the clutch chamber 24, and from the crank chamber 20 as the piston 33 (see FIG. 5) moves up and down. Air enters and exits the clutch chamber 24.

  8 is a left side view showing a state in which the cover 39 and the annular stator 70 for the generator 40 are attached to the left crankcase 10 shown in FIG. 6, FIG. 9 is a perspective view of the cover 39, and FIG. It is XX arrow sectional drawing of the left crankcase 10 shown in FIG. As shown in FIG. 8, the cover 39 and the stator 70 have a circular shape when viewed from the left side, and are arranged concentrically with the crankshaft 30.

  As shown in FIG. 9, the cover 39 has a short truncated conical shape, and a flange 71 extending in the diameter-enlarging direction is formed on the entire circumference, and a plurality of (see FIG. In FIG. 9, four screw holes 72 are provided. The flange 71 is made of metal such as aluminum.

  As shown in FIG. 10, the cover 39 is disposed so that the top portion faces the back side (right side) of the recess 51 (projects toward the back side), and the cover 39 is arranged with respect to the left end portion of the projection 50. The flange 71 is screwed with the stator 70 interposed therebetween. As a result, the opening of the recess 51 is covered with the cover 39, and an oil return chamber 73 is formed on the back side of the cover 39. The oil return chamber 73 has oil inlets 52 and 53 and oil outlets 60 and 61 as shown in FIG. 8, and is shielded from the clutch chamber 24 by a cover 39 as shown in FIG.

  The plurality of vent holes 66 provided in the partition wall 38 are provided so as to open toward the stator 70 in a state where the stator 70 is fixed to the protruding portion 50. Accordingly, the blow-by gas flowing from the crank chamber 20 through the vent hole 66 is blown to the stator 70, and the stator 70 is cooled. The crankshaft 30 supported by the bearing portion 30a passes through the centers of the cover 39 and the stator 70 and protrudes into the clutch chamber 24, and a rotor 74 for the generator 40 is attached to the end thereof. .

  The flow of oil until the oil provided for lubrication of the valve operating system in the cylinder heads 6a and 7a (see FIGS. 2 and 3) is returned to the oil pan 9 is as follows. That is, as shown in FIGS. 8 and 10, the oil that has flowed down through the oil pipes 56 and 57 flows down through the oil inflow passages 54 and 55 and flows into the oil return chamber 73 from the oil inflow ports 52 and 53. The oil that has flowed into the oil return chamber 73 flows out from the oil outlets 60 and 61, flows down through the oil outlets 62 and 63, and is returned to the oil pan 9 (see FIG. 4).

  Since the oil return chamber 73 is cut off from the clutch chamber 24 by the cover 39, the oil flowing into the clutch chamber 24 is prevented from leaking into the clutch chamber 24 while preventing the oil flowing in from the oil inlets 52 and 53 from flowing into the oil outlets 60 and 61. Can be guided. Further, the cover 39 protrudes toward the back side of the oil return chamber 73, and the oil dropped from the oil inflow ports 52 and 53 bounces back on the inner surface of the cover 39 and goes to the back side, so that it leaks into the clutch chamber 24. Can be further prevented.

  Further, since the cover 39 and the stator 70 are provided in contact with each other, the heat generated in the stator 70 is transmitted to the cover 39 and radiated. Since the oil flowing in from the oil inflow ports 52 and 53 comes into contact with the cover 39, the heat radiation from the cover 39 is further promoted, and the stator 70 that has a relatively high temperature can be cooled.

  Note that the cover 39 does not necessarily have a truncated cone shape, and may be, for example, a disk shape, as long as the oil return chamber 73 can be shielded from the clutch chamber 24. The recess 51 is not always necessary. For example, a space shielded from the clutch chamber 24 may be formed by arranging the cover 39 so that the top portion is directed outward (left side). That is, other configurations may be used as long as the oil movement route from the oil inlets 52 and 53 to the oil outlets 60 and 61 can be shielded in the clutch chamber 24. And the stator 70 may not be in contact with each other.

  In the present embodiment, the oil flow path formed in the partition wall 38 communicates with the oil return chamber 73 through the oil inlets 52 and 53 and the oil outlets 60 and 61. However, the present invention is not limited to this configuration. . That is, the oil inflow passages 54 and 55 and the oil outflow passages 62 and 63 may be directly connected to form an oil passage. In this case, the cover 39 is not necessary and the oil does not leak into the clutch chamber 24 without providing the oil return chamber 73.

[Oil pan]
FIG. 11 is a perspective view of the oil pan 9. As shown in FIG. 11, the oil pan 9 has a rectangular shape that is long in the front-rear direction in plan view. A partition wall 80 is erected at a position rearward of the center in the front-rear direction. The partition wall 80 partitions the front crank chamber oil pan 81 and the rear mission chamber oil pan 82.

  The crank chamber oil pan 81 is inclined so that the inner bottom surface is directed downward from the left and right ends to the center position, and the bottom thereof is an oil reservoir 83 whose cross section perpendicular to the front-rear direction forms a wedge shape. ing. An oil strainer 84 having a long tubular shape is disposed in the oil reservoir 83 with its longitudinal direction aligned with the front-rear direction. The oil strainer 84 has a suction port 85 in the lower peripheral surface, and a rear end is provided in contact with the partition wall 80.

  An oil passage 86 is integrally formed in the mission chamber oil pan 82, and the oil passage 86 extends in the front-rear direction at the left and right center positions of the mission chamber oil pan 82. The oil passage 86 extends forward to the partition wall 80 and communicates with an oil strainer 84 provided in the crank chamber oil pan 81.

  On the other hand, the rear part extends to the rear end of the oil pan 9 and can communicate with the outside through the drain plug 87. Therefore, when the oil is changed, the oil accumulated in the crank chamber oil pan 81 can be discharged to the outside by removing the drain plug 87. The oil passage 86 branches in the middle of the front-rear direction and extends upward, and communicates with a crank chamber scavenging pump described later.

  The oil pan 9 described above forms the bottom of the crank chamber 20 and the transmission chamber 21, and the crank chamber 20 and the clutch chamber 24 shown in FIG. 5 partitioned by the partition wall 38 do not share the oil pan 9. . Therefore, as shown in FIG. 4, the oil flow for the oil is restricted by being blocked by the partition wall 38 between the crank chamber oil pan 81 forming the bottom of the crank chamber 20 and the bottom 24 a of the clutch chamber 24. For example, as described above, oil that has flowed down through the oil inflow passages 54 and 55, the oil return chamber 51, and the oil outflow passages 62 and 63 is accumulated in the oil pan 81 for the crank chamber, and the oil enters the clutch chamber 24. It is difficult to do.

[Oil pump]
12 is a cross-sectional view of the engine E shown in FIG. 2 taken along XII-XII, and FIG. 13 is a right side view of the left crankcase 10. As shown in FIGS. 12 and 13, an oil pump 90 is provided below the crankcase 8. More specifically, a pump casing 92 is formed integrally with the left crankcase 10 below the partition wall 91 that partitions the crank chamber 20 and the transmission chamber 21 (see also FIG. 4).

  As shown in FIG. 12, the pump casing 92 has a substantially cylindrical shape with a step that is open on the left side (the clutch chamber 24 side) with the central axis aligned in the left-right direction. Three pump rotors are fitted into the pump casing 92, and a pump shaft 93 shared by the rotors is fitted into the shaft core. As a result, as the oil pump 90, a crank chamber scavenging pump 94, a clutch chamber scavenging pump 95, and a feed pump 96 are formed in order from the right side.

  Further, the left end portion of the pump shaft 93 is connected to the left end portion of the balancer shaft 37 by a chain 93a (see FIG. 2), and rotates in conjunction with the balancer shaft 37. In this embodiment, all the pumps are trochoidal.

  An oil suction passage 100 extends downward from the inner peripheral portion of the pump casing 92, and the oil suction passage 100 communicates with an oil passage 86 formed in the oil pan 9. Accordingly, the crank chamber oil pan 81 (see FIG. 11) communicates with the suction port (not shown) of the crank chamber scavenging pump 94 through the oil passage 86 and the oil suction passage 100.

  As shown in FIG. 12, another oil suction passage 101 that is recessed in the diameter increasing direction is formed in the inner bottom portion of the pump casing 92 from the substantially central portion in the left-right direction to the left end portion (see FIG. 4). . As shown in FIG. 4, an oil reservoir 102 that is recessed downward is formed on the inner bottom of the left crankcase 10 and the inner clutch cover 12 and on the extension of the oil suction passage 101 to the left. ing.

  As shown in FIG. 12, an oil pipe 103 is disposed in the oil reservoir 102 so that the shaft core extends in the left-right direction. The oil pipe 103 has an opening for sucking the oil in the oil reservoir 102 at the lower part of the peripheral surface at the left end, and the right end communicates with the oil suction path 101. Accordingly, the clutch chamber 24 communicates with the suction port (not shown) of the clutch chamber scavenging pump 95 through the oil pipe 103 and the oil suction passage 101.

  As shown in FIG. 13, an oil discharge path 104 is formed in a partition wall 91 that partitions the crank chamber 20 and the transmission chamber 21. The oil discharge passage 104 extends in the left-right direction from a partition wall 91 provided in the left crankcase 10 to a partition wall 91 (see FIG. 4) provided in the right crankcase 11.

  The oil discharge passage 104 communicates with a discharge port (not shown) of the crank chamber scavenging pump 94 and the clutch chamber scavenging pump 95 shown in FIG. It communicates with the connected oil pipe 105 (see FIG. 3). As shown in FIG. 3, the oil pipe 105 is connected to the lower part of the outer mission cover 17, and communicates with the oil storage chamber 26 (see FIG. 5) from below.

  As shown in FIG. 12, an oil strainer 106 is disposed in the mission chamber oil pan 82, and the oil strainer 106 communicates with the suction port of the feed pump 96 via an oil suction path (not shown). An oil discharge port (not shown) of the feed pump 96 communicates with various parts of the engine E through a main gallery (not shown) formed in the crankcase 8.

  The crank chamber scavenging pump 94, the clutch chamber scavenging pump 95, and the feed pump 96 described above are driven by the pump shaft 93 rotating in conjunction with the balancer shaft 37. The right end of the pump shaft 93 is connected to a water pump 97 via a gear, and the water pump 97 is also driven in conjunction with the balancer shaft 37.

[Oil flow]
The oil flow in the engine E will be described. FIG. 14 is a schematic diagram for explaining the flow of oil in the engine E. FIG. As shown in FIG. 14, the oil stored in the transmission chamber 21 forming the oil tank is sucked up by a feed pump 96 that is driven by the operation of the engine E, and is pumped to various places in the engine E through the main gallery 110. The

  The pumped oil is filtered by the oil filter 111, and on the one hand, supplied to the crankshaft 30 and used for lubrication of the sliding contact surface between the crankpin 31 and the connecting rod 32 (see FIG. 5). It is also supplied into the rocker shafts 112 and 113 provided in the heads 6a and 7a to be used for lubricating the valve train.

  The oil provided for lubrication or the like by the crankshaft 30 then drops in the crank chamber 20 and is collected in an oil reservoir 83 formed in the oil pan 9. The oil used for valve system lubrication flows down in the oil pipes 56 and 57 and the oil inflow passages 54 and 55, passes through the oil return chamber 73, then flows down in the oil outflow passages 62 and 63, and the oil pan. Nine oil reservoirs 83 are collected. Since the oil return chamber 73 is shielded in the clutch chamber 24, the oil flowing down from the cylinder heads 6a and 7a can be prevented from leaking into the clutch chamber 24. The oil reservoir 83 is provided in the lower part of the crank chamber 20, and the crank chamber 20 and the clutch chamber 24 are partitioned by the partition wall 38, so that the oil collected in the oil reservoir 83 flows out into the clutch chamber 24. There is nothing.

  The oil collected in the oil reservoir 83 is sucked into the crank chamber scavenging pump 94 through the oil strainer 84, the oil passage 86 (see FIG. 11), and the oil suction passage 100 (see FIG. 12), and the oil discharge passage. 104 and the oil pipe 105 are discharged into the oil storage chamber 26. Further, the oil stored in the oil storage chamber 26 is injected from a plurality of oil injection holes 47 through the oil passages 43 in the main shaft 41 and the counter shaft 42 to lubricate the transmission 46, and then forms an oil tank. Returned to the transmission chamber 21.

  A relief valve 114 is provided in the middle of the main gallery 110. When the hydraulic pressure in the main gallery 110 exceeds a predetermined reference value, the relief valve 114 is opened and depressurized.

  Further, blow-by gas is generated in the crank chamber 20, and the blow-by gas travels between the crank chamber 20 and the clutch chamber 24 through the vent hole 66 as the piston 33 moves up and down. At this time, part of the oil contained in the blow-by gas flowing into the clutch chamber 24 adheres to the inner wall of the clutch chamber 24. A part of the blow-by gas that has flowed in is separated into gas and liquid, and the liquid oil is collected in an oil reservoir 102 formed in the inner bottom of the clutch chamber 24.

  The oil collected in the oil reservoir 102 is sucked into the clutch chamber scavenging pump 95 through the oil pipe 103 and the oil suction passage 101 (see also FIG. 12). The oil sucked into the clutch chamber scavenging pump 95 is discharged to the oil storage chamber 26 through the oil discharge passage 104 and the oil pipe 105 in the same manner as the oil sucked into the crank chamber scavenging pump 94. The oil is returned from the oil injection hole 47 to the transmission chamber 21 forming the oil tank through the oil passage 43 in the shaft 41 and the counter shaft 42.

  In this manner, the crank chamber scavenging pump 94 and the clutch chamber scavenging pump 95 are separately provided, and oil in the crank chamber 20 and the clutch chamber 24 is collected by independent routes. Therefore, even in the motorcycle 1 equipped with the engine E having the clutch chamber 24 on the same left side as the side stand 5 as in the present embodiment, the oil in the clutch chamber 24 can be efficiently recovered, 45 can be prevented from being soaked in oil.

  Further, since the crank chamber 20 and the clutch chamber 24 are partitioned by the partition wall 38 and the oil flow between the two chambers is restricted, for example, the oil accumulated in the oil pan 9 or adhered to the inner wall of the crank chamber 20. It is possible to prevent the oil that has entered from entering the clutch chamber 24.

  On the other hand, when the engine E is stopped, the oil supplied to the rocker shafts 112 and 113 and used for lubricating the valve operating system flows down to the clutch chamber 24 through the oil pipes 56 and 57. Since the scavenging pump 95 for the clutch chamber is stopped when the engine E is stopped, the oil collected in the clutch chamber 24 thereafter is accumulated in the oil reservoir 102 and cannot be collected in the transmission chamber 21.

  However, in the case of the engine E according to the present embodiment, the oil flowing down the oil pipes 56 and 57 passes through the oil return chamber 73 that is shielded against the outside in the clutch chamber 24, and therefore the oil return chamber 73. Oil does not leak into the outer clutch chamber 24. Therefore, it is possible to prevent oil from collecting in the clutch chamber 24 after the engine E is stopped and the clutch 45 from being oiled.

  In the present embodiment, the engine E is described in which the side stand 5 is on the left side of the vehicle body and the clutch chamber 24 is positioned on the left side of the crank chamber 20, but the side stand is on the right side of the vehicle body and the clutch The present invention can also be applied to an engine whose chamber is located on the right side of the crank chamber.

  In addition, the crank chamber 20, the transmission chamber 21, the output shaft chamber 22, and the separator chamber 23 show the engine E that is integrally formed by the crankcase 8. However, the present invention is not limited to this, and each has an independent configuration. There may be.

  Alternatively, an engine that outputs rotation from the end of the countershaft 42 to the rear wheel 3 via a pulley or sprocket without the output shaft 48 may be used.

  Furthermore, the present invention is not limited to an engine mounted on an American type motorcycle, but can be applied to other types of motorcycle engines as long as the engine circulates oil via a clutch chamber.

  The present invention can be applied particularly to an engine mounted on a motorcycle, and can be applied to various types of motorcycles in addition to the American type.

1 is a left side view of a motorcycle equipped with an engine according to an embodiment of the present invention. FIG. 2 is a left side view of the engine shown in FIG. 1 with a part cut away. FIG. 2 is a right side view of the engine shown in FIG. 1 with a part cut away. It is a disassembled perspective view which shows the main housing components of the engine except a cylinder. FIG. 5 is a VV cross-sectional view of the engine shown in FIG. 2. It is the left view which partially showed the left crankcase which comprises a clutch chamber. It is VII-VII sectional drawing of the left crankcase shown in FIG. FIG. 7 is a left side view showing a state in which a cover and a stator for a generator are attached to the left crankcase shown in FIG. 6. It is a perspective view of a cover. It is XX sectional drawing of the left crankcase shown in FIG. It is a perspective view of an oil pan. It is XII-XII sectional drawing of the engine shown in FIG. It is a right view of a left crankcase. It is a schematic diagram for demonstrating the flow of the oil in the engine which concerns on this Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Motorcycle 5 Side stand 6, 7 Cylinder 8 Crankcase 9 Oil pan 10 Left crankcase 11 Right crankcase 12 Inner clutch cover 13 Outer clutch cover 20 Crank chamber 21 Transmission chamber 22 Output shaft chamber 23 Separator chamber 24 Clutch chamber 30 Crankshaft 30a Bearing part 38 Partition 39 Cover 40 Generator 45 Clutch 50 Protrusion part 51 Depression part 52, 53 Oil inlet 54, 55 Oil inlet 56, 57 Oil pipe 60, 61 Oil outlet 62, 63 Oil outlet 66 66 Vent hole 70 Stator 73 Oil return chamber 81 Crank chamber oil pan 82 Mission chamber oil pan 83 Oil reservoir 90 Oil pump 94 Crank chamber scavenging pump 95 Clutch chamber scavenging port Flop 96 the feed pump 102 oil reservoir portion

Claims (8)

A crank chamber that houses the crankshaft and has an oil pan at the bottom;
A clutch chamber disposed adjacent to the crank chamber and storing a clutch;
A partition partitioning the crank chamber and the clutch chamber,
An oil inlet through which oil flowing into the clutch chamber passes and an oil outlet through which oil flows out from the clutch chamber to the oil pan pass through the partition wall near the crankshaft bearing portion. Formed to open to the chamber,
Furthermore, an oil inflow passage leading to the oil inlet and an oil outlet passage from the oil outlet to the oil pan are formed in the partition.
A cover is provided in the clutch chamber so as to cover the oil inlet and the oil outlet in order to prevent the oil flowing in from the oil inlet from scattering and to guide the oil to the oil outlet. A motorcycle engine characterized by this. A recess is formed in the partition wall, the oil inlet and the oil outlet are formed at the back of the recess, and the cover is provided to close the opening of the recess. The motorcycle engine according to claim 1 . The motorcycle engine according to claim 2 , wherein the cover has a weight shape and is provided so as to protrude to the back side of the recess. The said cover is metal , The stator of the generator for electric power generation is attached to the said partition close to the said cover in the said clutch chamber, The Claim 1 thru | or 3 characterized by the above-mentioned. Motorcycle engine. The motorcycle engine according to claim 4 , wherein the generator stator is provided between the partition and the cover . Between the crank chamber and the clutch chamber, the partition wall restricts the flow of oil between the bottom portions, and scavenging for sucking the oil accumulated in the inner bottom portions of the crank chamber and the clutch chamber. motorcycle engine according to claim 1 to 5, characterized in that it comprises a pump. The motorcycle engine according to claim 6 , wherein the clutch chamber is disposed on the same side as the side stand with respect to the vehicle body with respect to the crank chamber. A motorcycle equipped with the engine according to any one of claims 1 to 7 .

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