JP4372492B2 - engine - Google Patents

Description

  The present invention relates to an engine, and more particularly to an engine characterized by an oil pump.

  In the engine, oil (engine oil) is used for lubricating parts such as a crankshaft and a rocker shaft. Oil is pumped to various places by an oil pump and circulates in the engine. One of the oil circulation systems is a dry sump system (see Patent Document 1). In the case of a dry sump engine, the oil in the oil tank is pumped to various places and used for lubrication, and the oil used for lubrication flows down and is collected in an oil pan. The oil collected in the oil pan is collected in the oil tank and pumped again to various places.

  Therefore, in a dry sump type engine, an oil pump (feed pump) for pumping oil from the oil tank to various places and an oil pump (scavenging pump) for collecting the oil collected in the oil pan to the oil tank are provided. I need. Further, in an engine with a relatively large output, the oil pump is also required to have a large capacity, and therefore, a plurality of feed pumps or scavenging pumps may be provided, and a total of three or more oil pumps may be provided.

There is a wet sump type as another oil circulation method. In the case of a wet sump engine, the oil collected in the oil pan is pumped to various places without being collected in the oil tank. Therefore, it has only a feed pump that pumps the oil in the oil pan to various places. However, in the case of an engine with a large output or an engine with a plurality of oil circulation routes, a feed corresponding to each route is provided. There may be a plurality of pumps.
Japanese Patent Laid-Open No. 2003-14094

  By the way, in an engine provided with a plurality of oil pumps as described above, if each oil pump is provided independently, an increase in the number of parts, a decrease in productivity, and an increase in the size of the engine may occur. However, in the case of an engine mounted on a motorcycle, for example, there is a limit to the size of the engine that can be mounted, and a reduction in the number of parts and an improvement in productivity are desired.

  Therefore, an object of the present invention is to provide an engine including an oil pump that can be reduced in size and weight without reducing the capacity and can improve productivity.

  The present invention has been made in view of the circumstances as described above, and an engine according to the present invention includes a pump shaft and a plurality of pumps that are arranged side by side on the pump shaft and operate as the pump shaft rotates. An oil pump having each rotor of the pump and an integrally formed pump casing that houses the plurality of rotors is provided.

  In such a configuration, the number of parts can be reduced as compared with the case where a plurality of oil pumps are configured independently, and the oil pump can be reduced in size and weight without reducing the capacity. Can do.

  Further, an engine housing may be provided, and the pump casing may be formed integrally with the engine housing. In such a configuration, when an engine housing such as a crankcase is manufactured, the number of parts and the number of assembly operations can be reduced by integrally forming the pump casing at the same time.

  The pump casing has a cylindrical shape having a closed end and an open end, and the inner diameter is the same from the closed end side to the open end side, or the inner diameter increases from the closed end side to the open end side. The pump shaft may be arranged along the axis of the pump casing, and the rotor may be arranged in parallel from the closed end side to the open end side of the pump casing.

  In such a configuration, the oil pump can be configured by fitting a plurality of rotors in order from the opening end of the pump casing, and the assembly of the oil pump is easy. In addition, since the oil pump can be easily disassembled by taking out each rotor from the opening end, the maintainability of the oil pump is improved.

  In the pump casing, the rotors of the first oil pump, the second oil pump, and the third oil pump may be arranged in parallel from the closed end side to the open end side. In such a configuration, for example, an engine that requires one feed pump and a scavenging pump for each of the crank chamber and the clutch chamber, or one scavenging pump and two feed pumps, In an engine or the like that requires the above, the above-described effects can be achieved.

  Further, a first port portion constituting an oil intake port and a discharge port for the first oil pump may be integrally formed on an inner wall of the closed end of the pump casing. In the case of such a configuration, it is not necessary to separately prepare members constituting the suction port and the discharge port for the first oil pump, and the number of parts and the number of assembling operations can be reduced.

  An oil discharge route for the second oil pump may be formed on the inner wall of the peripheral portion of the pump casing. In the case of such a configuration, it is not necessary to separately prepare a pipeline that forms the discharge route, and it is not necessary to attach the pipeline.

  The first oil pump and the second oil pump are scavenging pumps, and a discharge route for the second oil pump extends from a substantially central position of the pump casing to the closed end side, and You may communicate with the discharge port for oil pumps.

  In the case of such a configuration, when two scavenging pumps are provided, the oil discharged from each can be merged and sent to the oil tank. Accordingly, the structure can be simplified and the size can be reduced as compared with the case where the oil discharged from each is sent to the oil tank via another route.

  In addition, an oil suction route for the second oil pump, which is recessed in the diameter-enlarging direction and forms a groove shape, extends from a substantially central position to the opening end side on the inner wall of the peripheral portion of the pump casing. Good. In the case of such a configuration, it is not necessary to separately prepare a pipeline that forms the suction route, and an installation work for the pipeline is also unnecessary.

  A second port member having a suction port and a discharge port for the second oil pump is provided between the rotor of the first oil pump and the rotor of the second oil pump. The port member may also form a seal member between the first oil pump and the second oil pump.

  In such a configuration, since the seal between the first oil pump and the second oil pump arranged side by side can be realized by the second port member, it is necessary to prepare a seal member separately. Absent. Therefore, the number of parts can be reduced.

  A third port member having a suction port and a discharge port for the third oil pump is provided between the rotor of the third oil pump and the rotor of the second oil pump. The port member may also form a seal member between the third oil pump and the second oil pump.

  In such a configuration, since the seal between the second oil pump and the third oil pump arranged side by side can be realized by the third port member, it is necessary to prepare a seal member separately. Absent. Therefore, the number of parts can be reduced.

  Further, a suction route for the second oil pump, which is recessed in the diameter increasing direction and forms a groove shape, extends from a substantially central position to the opening end side on the inner wall of the peripheral portion of the pump casing. A check valve may be provided to prevent the oil from flowing back along the route.

  When the suction route is extended on the inner wall of the peripheral portion of the pump casing, the oil flowing through the suction route may flow backward after the second oil pump is stopped, particularly when the pump casing is arranged so that the shaft core is substantially horizontal. . By providing the check valve as described above, it is possible to prevent such back flow of oil in the suction route.

  For example, when the second oil pump is used to recover the oil in the clutch chamber to the oil tank, the oil in the oil tank may flow back to the clutch chamber through the suction route after the second oil pump is stopped. There is. When oil flows into the clutch chamber, the clutch may be immersed in oil, which may affect the operability of the clutch. Therefore, by providing the check valve as described above, it is possible to prevent the oil from being immersed in the clutch and to maintain the operability of the clutch satisfactorily.

  The check valve may include a valve portion and a housing portion that houses the valve portion, and the housing portion may be integrally formed with the engine housing. In the case of such a configuration, it is not necessary to prepare a separate check valve casing, and it is not necessary to arrange the casing.

  ADVANTAGE OF THE INVENTION According to this invention, the engine provided with the oil pump which can be reduced in size and weight without reducing a capacity | capacitance and can aim at the improvement of productivity 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. 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. The cylinders 6 and 7 have cylinder heads 6a and 7a at their upper parts, and a valve operating system (not shown) such as a valve and a rocker shaft inside the cylinder heads 6a and 7a.

[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.

  The left crankcase 10, the inner clutch cover 12, and the outer clutch cover 13 are formed with an oil reservoir 24 a whose inner bottom is recessed downward. Oil collected in the clutch chamber 24 is stored in the oil reservoir 24a.

  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. . Accordingly, the number of parts can be reduced as compared with the case where each of the chambers 20 to 24 is configured separately, so that the engine weight and the number of assembly work steps can also be reduced. Further, the engine E can be made compact.

[Power transmission structure]
The left crankcase 10 and the right crankcase 11 described above are provided with a plurality of shafts for transmitting the power of the engine E. 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 31, and the crankshaft 30 is rotatably supported by the bearing portion 31 so that the shaft core is directed in the left-right direction. A piston 34 is connected to the crankpin 32 of the crankshaft 30 via a connecting rod 33.

  The right end of the crankshaft 30 penetrates the right crankcase 11 and protrudes into the cam chamber 25, and is connected to cam sprockets 35 and 36 (see FIG. 3) via a chain. Further, the right end portion of the crankshaft 30 is also connected to balancer shafts 37 and 38 (see FIG. 3) disposed before and after the crankshaft 30 via a chain. The balancer shafts 37 and 38 rotate with the rotation of the crankshaft 30, and the balancer shaft 38 disposed on the rear side is an oil pump for pumping or sucking up oil circulating in the engine E (FIG. 6). The oil pump 71 is driven.

  As shown in FIG. 5, a partition wall 39 formed in the left crankcase 10 is provided between the crank chamber 20 and the clutch chamber 24 to partition both chambers. The bearing 31 described above is provided through the partition wall 39. The left end portion of the crankshaft 30 passes through a bearing portion 31 provided in the partition wall 39 and protrudes into the clutch chamber 24, and a generator 40 for power generation is provided at the left end portion.

  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 through sprockets 46 and 47 and a chain 48 in the clutch chamber 24.

  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 51 composed of a plurality of gears 50 having different diameters. When an operator operates a change lever (not shown), a predetermined gear 50 of the main shaft 41 and a counter shaft are arranged. 42 predetermined gears 50 mesh with each other. In addition, a plurality of oil injection holes 52 that pass through the peripheral portions of the main shaft 41 and the counter shaft 42 and communicate with the internal oil passage 43 are provided at the base positions of the plurality of gears 50 that form the transmission 51.

  An output shaft 53 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 53 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 53 and the right end portion of the counter shaft 42, and the rotational force of the counter shaft 42 is transmitted to the output shaft 53 via the gears.

  The left end portion of the output shaft 53 protrudes from the output shaft chamber 22 to the left side of the left crankcase 10, and a pulley 54 is provided at the left end portion. A belt is stretched between the pulley 54 and the shaft of the rear wheel 3 (see FIG. 1) of the motorcycle 1 so that the rotational force of the output shaft 53 is transmitted to the rear wheel 3. .

[Oil pan]
By the way, in the engine E according to the present embodiment, the oil circulation form is a dry sump type, and the oil lubricated in various places is once collected in the oil pan 9. FIG. 6 is a perspective view of the oil pan 9. As shown in FIG. 6, the oil pan 9 has a rectangular shape that is long in the front-rear direction in plan view. A partition wall 60 is erected at a position rearward of the center in the front-rear direction. The partition wall 60 partitions the front crank chamber oil pan 61 and the rear mission chamber oil pan 62.

  The crank chamber oil pan 61 is inclined so that the inner bottom surface is directed downward from the left and right ends to the center position, and the bottom of the oil pan 61 is an oil reservoir 63 having a wedge-shaped cross section perpendicular to the front-rear direction. ing. An oil strainer 64 having a long tubular shape is disposed in the oil reservoir 63 with its longitudinal direction coinciding with the front-rear direction. The oil strainer 64 has a suction port 65 in the lower peripheral surface, and a rear end is provided in contact with the partition wall 60.

  An oil passage 66 is integrally formed in the mission chamber oil pan 62, and the oil passage 66 extends in the front-rear direction at a central position on the left and right sides of the mission chamber oil pan 62. The oil passage 66 extends forward to the partition wall 60 and communicates with an oil strainer 64 provided in the crank chamber oil pan 61.

  On the other hand, it extends to the rear end of the oil pan 9 at the rear, and can communicate with the outside through the drain plug 67. Therefore, when the oil is changed, the oil accumulated in the crank chamber oil pan 61 can be discharged to the outside by removing the drain plug 67. The oil passage 66 branches in the middle of the front-rear direction and extends upward, and communicates with a crank chamber scavenging pump (see a crank chamber scavenging pump 72 in FIG. 7) described later.

  The oil pan 9 described above forms the bottom of the crank chamber 20 and the transmission chamber 21. As shown in FIG. 5, the crank chamber 20 and the clutch chamber 24 partitioned by the partition wall 39 are used to Not shared. Therefore, as shown in FIG. 4, the space between the oil pan 61 for the crank chamber 61 that forms the bottom of the crank chamber 20 and the bottom of the clutch chamber 24 is blocked by the partition wall 39 to restrict the oil flow.

[Oil pump]
FIG. 7 is a VII-VII cross-sectional view of the engine E shown in FIG. 2, and FIG. 8 is a right side view of the left crankcase 10. As shown in FIGS. 7 and 8, the left crankcase 10 is integrally formed with a partition wall 70 that partitions the crank chamber 20 and the transmission chamber 21, and an oil pump 71 is provided below the partition wall 70. Yes. As shown in FIG. 7, the oil pump 71 includes, in order from the right side of the engine E, a crank chamber scavenging pump (first oil pump) 72, a clutch chamber scavenging pump (second oil pump) 73, and a feed pump. (Third oil pump) 74 is provided, and these are configured such that respective rotors and the like are housed in a pump casing 75 integrally formed with the partition wall 70.

  FIG. 9 is a perspective view of the pump casing 75 with a part cut away. The pump casing 75 has a cylindrical shape having an open end 80 and a closed end 81. As shown in FIG. 7, the pump casing 75 is arranged with the open end 80 facing the left side.

  As shown in FIG. 9, in the pump casing 75, in order from the closed end 81 side, a first pump room 82 where the crank chamber scavenging pump 72 is located, and a second pump where the clutch chamber scavenging pump 73 is located. A room 83 and a third pump room 84 in which the feed pump 74 is located are provided. The first pump room 82 and the second pump room 83 have substantially the same diameter, and the third pump room 84 is expanded in diameter relative to the second pump room 83.

  The closed end 81 of the pump casing 75 is provided with a through hole, and forms a bearing portion 86 that rotatably supports a pump shaft 85 (see FIG. 7) that drives each pump. A first port portion 89 forming a first suction port 87 and a first discharge port 88 for oil of the crankcase scavenging pump 72 is formed integrally with the pump casing 75 on the inner wall of the closed end 81. Has been.

  A first suction route 90 extends downward from the first suction port 87. The first suction route 90 is connected to the crank chamber oil pan 61 via the oil passage 66 shown in FIG. Communicate (see also FIG. 7). A first discharge route 91 extends from the first discharge port 88 through the closed end 81.

  The first discharge route 91 is formed in a partition wall 70 (see FIG. 8) that partitions the crank chamber 20 and the transmission chamber 21, and extends rightward from the left crankcase 10 to the right crankcase 11. The first discharge route 91 communicates with an oil pipe 92 (see FIG. 3) connected to the right side portion of the right crankcase 11, and the oil pipe 92 is formed at the lower portion of the outer mission cover 17 as shown in FIG. It is connected and communicates with the oil storage chamber 26 (see also FIG. 5) from below.

  As shown in FIG. 9, a groove recessed in the diameter-expanding direction extends from the opening end 80 to the second pump room 83 in the lower inner wall portion of the pump casing 75, and the clutch chamber scavenging pump 73 second inhalation routes 95 are formed. In addition, a groove that is recessed in the diameter-expanding direction extends from the opening end 80 to the closing end 81 on the inner wall portion of the upper portion of the pump casing 75, and the second discharge route 96 of the clutch chamber scavenging pump 73. Is made. The second discharge route 96 communicates with the first discharge port 88 of the crankcase scavenging pump 72.

  From the third pump room 84, a third suction route 97 and a third discharge route 98 of the feed pump 74 are extended downward. The third suction route 97 and the third discharge route 98 are arranged on the front and rear sides of the second suction route 95 of the clutch chamber scavenging pump 73. As shown in FIG. 7, the third suction route 97 communicates with an oil suction part 99 disposed in the mission chamber oil pan 62. Further, the third discharge route 98 communicates with an oil gallery (not shown) extending to various parts of the engine E.

  FIG. 10 is an exploded perspective view showing the pump casing 75 constituting the oil pump 71, the rotor accommodated in the pump casing 75, and the like. In the first pump room 82 (see FIG. 9) closest to the closed end 81 of the pump casing 75, the first outer rotor 100 and the first inner rotor 101 are housed and cranked together with the first port portion 89 (see FIG. 9). A room scavenging pump 72 is configured.

  Accordingly, when the first outer rotor 100 and the first inner rotor 101 are operated, the oil sucked from the first suction port 87 shown in FIG. 9 is discharged to the first discharge port 88.

  In the second pump room 83 (see FIG. 9) located in the middle of the pump casing 75, the second port member 102, the second outer rotor 103, and the second inner rotor 104 are housed, and the scavenging pump for the clutch chamber is stored. 73 is constituted. A second suction port 105 and a second discharge port 106 are formed in the second port member 102. The second suction port 105 communicates with a second suction route 95 (see FIG. 9) formed on the lower inner wall of the pump casing 75, and the second discharge port 106 is a second discharge route formed on the upper inner wall of the pump casing 75. 96 (see FIG. 9).

  Accordingly, when the second outer rotor 103 and the second inner rotor 104 are operated, the oil sucked from the second suction port 105 is discharged to the second discharge port 106.

  The second port member 102 is disposed between the first outer rotor 100 and the first inner rotor 101, and the second outer rotor 103 and the second inner rotor 104, and is connected to the crank chamber scavenging pump 72. The gap between the clutch chamber scavenging pump 73 is sealed.

  In the third pump room 84 (see FIG. 9) on the most opening end 80 side of the pump casing 75, a bottomed cylindrical third port member 107 is fitted and inserted in the same direction as the pump casing 75. Yes. A third outer rotor 108 and a third inner rotor 109 are arranged in the third port member 107 to constitute a feed pump 74.

  A third suction port 110 and a third discharge port 111 are formed at the inner bottom (right back) of the third port member 107. The third suction port 110 communicates with a third suction route 97 (see FIG. 9) extending downward from the pump casing 75, and the third discharge port 111 is a third discharge route extending downward from the pump casing 75. 98 (see FIG. 9).

  Therefore, when the third outer rotor 108 and the third inner rotor 109 are operated, the oil sucked from the third suction port 110 is discharged to the third discharge port 111.

  The third port member 107 seals between the clutch chamber scavenging pump 73 and the feed pump 74, and a flange 112 is formed at the opening edge. An opening 113 communicating with the second suction route 95 of the clutch chamber scavenging pump 73 is provided at the lower portion of the flange 112.

  As described above, the pump casing 75 is integrally formed, and the diameter of the third pump room 84 is larger than that of the first pump room 82 and the second pump room 83. Therefore, the oil pump 71 can be easily assembled by sequentially storing the rotors in the pump casing 75. Moreover, it is easy to take out each rotor and it is excellent in maintainability.

  The pump cover 120 is provided at the open end 80 of the pump casing 75 in a state where the rotors and port members described above are accommodated in the pump casing 75. The pump cover 120 is fixed to the flange 112 of the third port member 107 housed in the pump casing 75. In the lower part of the pump cover 120, another opening 121 is provided so as to be aligned with the opening 113 of the flange 112 so as to communicate with the second suction route 95 of the clutch chamber scavenging pump 73.

  The pump shaft 85 passes through the approximate center of the pump cover 120, each rotor, and each port member, along the axis of the pump casing 75, and one end 122 of the pump cover 120 extends from the pump cover 120 to the outside (left side). It protrudes. The one end portion 122 is provided with a sprocket 123, and is connected to a rear balancer shaft 38 (see FIG. 2) via a chain 124.

  Further, the other end portion 125 of the pump shaft 85 passes through a bearing portion 86 formed at the closed end 81 of the pump casing 75 and protrudes to the outside (right side). The other end portion 125 is provided with a drive gear 126. The drive gear 126 drives a water pump 127 provided in the right crankcase 11 as shown in FIG. Further, the first inner rotor 101, the second inner rotor 104, and the third inner rotor 109 are fixed to the pump shaft 85.

  In the oil pump 71 described above, the pump shaft 85 rotates in conjunction with the balancer shaft 38 (see FIG. 2), and the first inner rotor 101, the second inner rotor 104, and the third inner rotor 109 rotate. As a result, the crank chamber scavenging pump 72, the clutch chamber scavenging pump 73, and the feed pump 74 operate simultaneously.

  As shown in FIG. 7, one end of an oil pipe 130 is connected to the opening 121 provided in the lower part of the pump cover 120. The oil pipe 130 is laid at the bottom of the left crankcase 10, and the other end is connected to a check valve 131. The check valve 131 includes a valve portion 132 made of a ball, a spring, and the like, and a housing portion 133 that houses the valve portion 132, and the housing portion 133 is integrated with the inner clutch cover 12. (See also Fig. 4).

  Therefore, the check valve 131 has a small number of independent components and is easy to assemble. Note that the configuration of the check valve 131 is not limited to that described above, and other known configurations may be applied. However, the case portion is integrally formed with the housing of the engine E as described above. Similar effects can be obtained.

  As shown in FIG. 7, one end of an oil pipe 134 is further connected to the check valve 131, and the other end of the oil pipe 134 is connected to an oil strainer 135. The oil pipe 134 communicates with the oil pipe 130 via the check valve 131. The oil strainer 135 is disposed in an oil reservoir 24 a provided at the bottom of the outer clutch cover 13. The check valve 131 allows the oil to flow from the oil strainer 135 to the clutch chamber scavenging pump 73 and restricts the reverse flow.

[Oil flow]
The flow of oil in the engine E configured as described above will be described with reference to FIGS. FIG. 11 is a schematic diagram showing the flow of oil in the engine E. In the crank chamber 20, oil that has been used for lubrication is collected in various places. That is, the oil used for valve train lubrication by the cylinder heads 6 a and 7 a and the oil that has finished the lubrication of the crankshaft 30 flow down and are collected in the crank chamber 20. The oil is sucked up by the crank chamber scavenging pump 72 and collected in the transmission chamber 21 forming an oil tank.

  The oil flow accompanying the operation of the crankcase scavenging pump 72 in the above-described oil flow will be described in detail with reference to FIG. As the pump shaft 85 (see FIG. 10) rotates, the first inner rotor 101 and the first outer rotor 100 rotate, and the crank chamber scavenging pump 72 operates.

  As a result, the oil stored in the crank chamber oil pan 61 (see FIG. 6) at the bottom of the crank chamber 20 passes through the oil strainer 64 and the oil passage 66, and further through the first suction route 90 shown in FIG. Sucked into port 87. The oil sucked up to the first suction port 87 is pumped by the first outer rotor 100 and the first inner rotor 101 and discharged to the first discharge port 88. The discharged oil is sent out from the first discharge port 88 through the first discharge route 91, and further recovered into the oil storage chamber 26 through the oil pipe 92 as shown in FIG.

  As shown in FIG. 11, the oil recovered into the oil storage chamber 26 is injected from a plurality of oil injection holes 52 through the oil passages 43 in the main shaft 41 and the counter shaft 42 and lubricates the transmission 51. Then, it is collected in the transmission chamber 21.

  On the other hand, as shown in FIG. 11, a part of the oil used for lubrication in various places is a vent hole 140 provided in the partition wall 39 that partitions the crank chamber 20 and the clutch chamber 24 (see also FIG. 8). Through the clutch chamber 24. The oil collected in the clutch chamber 24 is sucked up by the clutch chamber scavenging pump 73 and collected in the transmission chamber 21.

  The oil flow accompanying the operation of the clutch chamber scavenging pump 73 in the above-described oil flow will be described in detail with reference to FIG. As the pump shaft 85 (see FIG. 10) rotates, the second inner rotor 104 and the second outer rotor 103 rotate, and the clutch chamber scavenging pump 73 operates.

  As a result, the oil stored in the oil reservoir 24a (see FIG. 11) in the clutch chamber 24 passes through the oil strainer 135, the check valve 131, and the second suction route 95 shown in FIG. Suctioned up to the suction port 105. The oil sucked up to the second suction port 105 is pumped by the second outer rotor 103 and the second inner rotor 104 and discharged to the second discharge port 106. The discharged oil is sent out from the second discharge port 106 through the second discharge route 96, and is sent to the first discharge port 88 communicating with the second discharge route 96.

  As shown in FIG. 11, the oil flowing through the first discharge port 88 together with the oil discharged from the crank chamber scavenging pump 72 (see FIG. 12), the oil storage chamber 26 through the first discharge route 91 and the oil pipe 92. To be recovered. The oil collected into the oil storage chamber 26 is injected from a plurality of oil injection holes 52 through the oil passages 43 in the main shaft 41 and the countershaft 42 to lubricate the transmission 51 and then recovered in the transmission chamber 21. Is done.

  The oil collected in the transmission chamber 21 as described above is pressure-fed to various parts of the engine E through the oil gallery 141 by the feed pump 74 as shown in FIG. The pumped oil is filtered by the oil filter 142 and then used for lubricating the crankshaft 30, or supplied to the rocker shafts 143 and 144 by the cylinder heads 6a and 7a and used for lubricating the valve train. The

  The oil flow accompanying the operation of the feed pump 74 in the above-described oil flow will be described in detail with reference to FIG. As the pump shaft 85 (see FIG. 10) rotates, the third inner rotor 109 and the third outer rotor 108 rotate, and the feed pump 74 operates.

  As a result, as shown in FIG. 7, the oil stored in the mission chamber oil pan 62 is sucked up to the third suction port 110 through the oil suction portion 99 and the third suction route 97. As shown in FIG. 14, the oil sucked up to the third suction port 110 is transported by the third outer rotor 108 and the third inner rotor 109 and discharged to the third discharge port 111. The discharged oil is pumped from the third discharge port 111 through the third discharge route 98 to various places in the engine E through the oil gallery 141 shown in FIG.

  By the way, when the engine E stops, the balancer shaft 38 (see FIG. 3) also stops, so the pump shaft 85 (see FIG. 10) does not rotate and the oil pump 71 stops. At this time, the oil existing in the second suction port 105, the second discharge port 106, the second discharge route 96, etc. of the scavenging pump 73 for the clutch chamber shown in FIG. There is a case where it is likely to flow into the clutch chamber 24. In particular, as shown in FIG. 1, the motorcycle 1 according to the present embodiment has a side stand 5 on the left side of the vehicle body, and when the engine 1 is stopped and the motorcycle 1 is supported by the side stand 5, the clutch chamber 24 Since the engine E is tilted so that the oil flows downward, the oil easily flows into the clutch chamber 24.

  However, in the engine E according to the present embodiment, the check valve 131 is provided on the route that connects the clutch chamber scavenging pump 73 and the clutch chamber 24 as shown in FIG. After the stop, the oil does not flow backward from the clutch chamber scavenging pump 73 to the clutch chamber 24. Therefore, it is possible to prevent the clutch 45 from being immersed in oil after the engine E is stopped.

  A relief valve 145 is provided in the middle of the oil gallery 142, and when the hydraulic pressure in the oil gallery 142 exceeds a predetermined reference value, the relief valve 145 is opened and depressurized.

  In the case of the oil pump 71 mounted on the engine E as described above, the crank chamber scavenging pump 72, the clutch chamber scavenging pump 73, and the feed pump 74 are housed in one pump casing 75, and one Since the pump is driven by the pump shaft 85, the pump output performance is maintained and the number of parts is reduced and the size is reduced as compared with the case where each is configured separately.

  The pump casing 75 is formed integrally with the left crankcase 10, and each of the first suction port 87, the first discharge port 88, the second suction route 95, and the second discharge route 96 is formed integrally with the pump casing 75. Has been. Therefore, the number of parts can be reduced as compared with the case where each is provided independently, and the assembly work is also reduced.

  The oil pump 71 according to the present embodiment is suitable for a dry sump engine that collects oil separately from the crank chamber 20 and the clutch chamber 24. However, the present invention may be applied to an oil pump that is configured to include one scavenging pump and one feed pump by allowing oil to freely flow between the crank chamber 20 and the clutch chamber 24. If necessary, four or more pumps may be configured on one pump shaft and housed in one integrally formed pump casing.

  The engine according to the present invention is not limited to an American type motorcycle, and can also be applied to a road racer type and other types of motorcycles. Further, the present invention is not limited to motorcycles, and can be applied to engines such as four-wheel buggies and automobiles, and can include a small and high-performance oil pump as described above.

  The present invention can be applied to an engine mounted on a motorcycle, a four-wheel buggy or the like.

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 a perspective view of an oil pan. FIG. 3 is a VII-VII cross-sectional view of the engine shown in FIG. 2. It is a right view of a left crankcase. It is a perspective view of the pump casing which notched a part. It is a disassembled perspective view which shows the pump casing which comprises an oil pump, the rotor etc. which are accommodated in this pump casing. It is a schematic diagram which shows the flow of the oil in an engine. It is a schematic diagram which shows the flow of the oil accompanying operation | movement of the scavenging pump for crank chambers. It is a schematic diagram which shows the flow of the oil accompanying operation | movement of the scavenging pump for clutch chambers. It is a schematic diagram which shows the flow of the oil accompanying operation | movement of a feed pump.

Explanation of symbols

1 Motorcycle 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 24 Clutch chamber 24a Oil reservoir 26 Oil storage chamber 30 Crankshaft 39 Bulkhead 61 Crank chamber Oil pan 62 Mission chamber oil pan 70 Bulkhead 71 Oil pump 72 Crank chamber scavenging pump 73 Clutch chamber scavenging pump 74 Feed pump 75 Pump casing 80 Open end 81 Closed end 82 First pump room 83 Second pump room 84 Third pump room 85 Pump shaft 87 First suction port 88 First discharge port 89 First port portion 90 First suction route 91 First discharge route 95 Second suction route 96 Second discharge Route 97 Third suction route 98 Third discharge route 100 First outer rotor 101 First inner rotor 102 Second port member 103 Second outer rotor 104 Second inner rotor 105 Second suction port 106 Second discharge port 107 Third port Member 108 Third outer rotor 109 Third inner rotor 120 Pump cover 131 Check valve 132 Valve portion 133 Housing portion 135 Oil strainer 140 Ventilation hole

Claims (10)

An engine having a clutch chamber surrounded by a clutch cover on one side of the crankcase;
A pump shaft;
A first rotor of a first scavenging pump for a crank chamber, a second rotor of a second scavenging pump for a clutch chamber, which are arranged side by side on the pump shaft and operate in accordance with the rotation of the pump shaft ; A third rotor of the feed pump ;
An oil pump having an integrally molded pump casing that houses a plurality of the rotors ,
The pump casing has a cylindrical shape having a closed end and an open end, and is provided on the wall of the crankcase with the open end facing into the clutch chamber. The pump casing includes the first scavenging The pump, the second scavenging pump, and the feed pump are arranged in this order from the back side,
The peripheral inner wall of said pump casing, said to pass communication between the feed pump and across at the said clutch chamber second scavenging pump, engine characterized that you have formed a groove-like suction route.   The engine according to claim 1, further comprising an engine housing, wherein the pump casing is formed integrally with the engine housing. The pump casing is enlarged inner diameter according to the same inside diameter with the previous SL closed end reaches to the open end, or from the closed end side extending to the open end,
The pump shaft is disposed along the axis of the pump casing,
The engine according to claim 1, wherein the rotor is arranged in parallel from the closed end side to the open end side of the pump casing. The inner wall of the closed end of the pump casing, to claim 3 in which the first port portion forming a suction port and a discharge port of the oil for the first scavenging pump is characterized in that it is integrally molded The listed engine. The engine according to claim 4 , wherein an oil discharge route for the second scavenging pump is formed in the inner wall of the peripheral portion of the pump casing so as to form a groove shape that is recessed in the diameter increasing direction. Claim discharge route for the second scavenging pump, which extends from the approximate center of the pump casing to the closed end side, characterized in that it communicates with the discharge port for the first scavenging pump 5. The engine according to 5 . Between the rotor of the first scavenging pump and the rotor of the second scavenging pump, there is provided a second port member in which a suction port and a discharge port for the second scavenging pump are formed. The engine according to claim 3 , wherein the two-port member also forms a seal member between the first scavenging pump and the second scavenging pump. Between the rotor of the feed pump and the rotor of the second scavenging pump, there is provided a third port member in which a suction port and a discharge port for the feed pump are formed, and the third port member is 4. The engine according to claim 3 , further comprising a sealing member between a feed pump and the second scavenging pump. The engine oil pump according to claim 3 , wherein a check valve is provided to prevent oil from flowing back in the suction route for the second scavenging pump. 10. The check valve according to claim 9 , wherein the check valve includes a valve portion and a housing portion that houses the valve portion, and the housing portion is integrally formed with the engine housing. The listed engine.

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