JPWO2020067172A1 - Internal combustion engine - Google Patents

Abstract

It provides an internal combustion engine that can be made compact in the vehicle width direction, the number of parts is reduced, and the shaft of the auxiliary machine can be lubricated.
The engine-side drive shaft 64, which is rotatably supported by the internal combustion engine main body 40 and is rotated by the rotational torque generated by the internal combustion engine, the auxiliary machine 100, the auxiliary machine housing 101 attached to the internal combustion engine main body 40, and the auxiliary machine housing. It has an auxiliary machine main body 102 supported by 101, and an auxiliary machine drive shaft 114 rotatably supported in the auxiliary machine housing 101 so as to be coaxial with the engine side drive shaft 64 and drives the auxiliary machine main body 102. In an internal combustion engine, the inside of the engine side drive shaft 64 and the auxiliary machine drive shaft 114 is hollow, and the engine side drive shaft side hollow portion 64a and the auxiliary machine drive shaft side hollow portion 114a communicate with each other, and the hollow portions 64a, 114a Is configured as an oil channel.

Description

The present invention relates to an internal combustion engine.

Conventionally, in an internal combustion engine having an auxiliary machine, a technique for lubricating the joint member while maintaining the rigidity of the joint member connecting the engine side drive shaft and the auxiliary machine drive shaft has been known (for example, Patent Document 1). reference).

Japanese Unexamined Patent Publication No. 2014-137057

However, in the conventional technique, it is necessary to additionally provide an oil passage for the auxiliary drive shaft, and there is a problem that the number of parts increases and a member having no bearing is generated.
The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an internal combustion engine capable of making the vehicle width direction compact, reducing the number of parts, and lubricating the shaft of an auxiliary machine.

This specification includes all the contents of the Japanese patent application / Japanese Patent Application No. 2018-185941 filed on September 28, 2018.
The internal combustion engine is rotatably supported by the internal combustion engine main body (40, 270), and the engine side drive shaft (64, 294), which is rotated by the rotational torque generated by the internal combustion engine, an auxiliary machine (100), and the internal combustion engine. The auxiliary machine housing (101) attached to the engine main body (40, 270), the auxiliary machine main body (102) supported by the auxiliary machine housing (101), and the engine side in the auxiliary machine housing (101). In an internal combustion engine having an auxiliary machine drive shaft (114) rotatably supported so as to be coaxial with the drive shaft (64, 294) and driving the auxiliary machine main body (102), the engine side drive is performed. The inside of the shaft (64, 294) and the auxiliary machine drive shaft (114) is hollow, and the engine side drive shaft side hollow portion (64a, 294a) and the auxiliary machine drive shaft side hollow portion (114a) communicate with each other. The hollow portion (64a, 294a, 114a) is characterized in that it is configured as an oil passage.

In the above configuration, the auxiliary machine (100) may be a fuel pumping device (100) that pumps fuel.

Further, in the above configuration, the suction port (103) or the discharge port (104) of the fuel pumping device (100) or both of them may be oriented so as not to protrude outward in the vehicle width direction.

Further, in the above configuration, the engine side drive shaft (64, 294) may be the camshaft (64, 294) of the valve operating mechanism (63, 293).

Further, in the above configuration, the joint portion between the engine side drive shaft (64, 294) and the auxiliary machine drive shaft (114) may have a spline structure.

Further, in the above configuration, the auxiliary machine (100) may be located behind the front end portion (47a, 277a) of the internal combustion engine in the front-rear direction when mounted on the vehicle.

Further, in the above configuration, the auxiliary machine (100) may overlap with the vehicle body frame (12) in the side view of the vehicle.

Further, in the above configuration, the cylinder center (44a, 232a) of the internal combustion engine (13, 211) is biased to the left or right in the vehicle width direction, and the auxiliary machine (100) has the cylinder center (44a, 232a). It may be provided on the side opposite to the biased direction.

Further, in the above configuration, the center of the crank chamber of the internal combustion engine (13, 211) is biased to the left or right in the vehicle width direction, and the auxiliary machine (100) is provided on the side opposite to the direction in which the center of the crank chamber is biased. May be done.

Further, in the above configuration, the cooling air may be guided to the auxiliary machine (100) by the tank shroud (246) attached to the fuel tank (237).

The internal combustion engine is rotatably supported by the internal combustion engine main body and is rotated by the rotational torque generated by the internal combustion engine. An internal combustion engine having an auxiliary machine main body supported by the machine housing and an auxiliary machine drive shaft rotatably supported in the auxiliary machine housing so as to be coaxial with the engine side drive shaft and driving the auxiliary machine main body. In an engine, the inside of the engine side drive shaft and the auxiliary machine drive shaft is hollow, the engine side drive shaft side hollow portion and the auxiliary machine drive shaft side hollow portion communicate with each other, and the hollow portion is configured as an oil passage. Has been done. According to this configuration, when the auxiliary machine is provided, the size in the vehicle width direction can be reduced, the number of parts can be reduced, and the shaft of the auxiliary machine can be lubricated.

In the above configuration, the auxiliary machine may be a fuel pumping device that pumps fuel. According to this configuration, the fuel pumping device, which tends to get hot because it is arranged near the cylinder head, can be cooled by the oil in the oil passage.

Further, in the above configuration, the suction port and / or the discharge port of the fuel pumping device may be oriented so as not to protrude outward in the vehicle width direction. According to this configuration, the protruding portion of the fuel pumping device such as the suction port and the discharge port can be protected.

Further, in the above configuration, the engine-side drive shaft may be a camshaft of a valve operating mechanism. According to this configuration, since the fuel injection timing is the same as the rotation cycle of the cam, the fuel injection timing can be matched with the operation timing of the valve gear. As a result, it is not necessary to provide a reduction mechanism between the engine side drive shaft and the auxiliary machine drive shaft, and the size can be reduced.

Further, in the above configuration, the joint portion between the engine side drive shaft and the auxiliary machine drive shaft may have a spline structure. According to this configuration, it is possible to reduce the play in the circumferential direction between the engine side drive shaft and the auxiliary machine drive shaft.

Further, in the above configuration, the auxiliary machine may be located behind the front end portion of the internal combustion engine in the front-rear direction when mounted on the vehicle. According to this configuration, the auxiliary machine can be prevented from protruding in the front-rear direction with respect to the internal combustion engine.

Further, in the above configuration, the auxiliary machine may overlap with the vehicle body frame in the side view of the vehicle. According to this configuration, the auxiliary machine can be protected by the vehicle body frame.

Further, in the above configuration, the center of the cylinder portion of the internal combustion engine may be biased to the left or right in the vehicle width direction, and the auxiliary machine may be provided on the side opposite to the direction in which the center of the cylinder portion is biased. According to this configuration, when the auxiliary machine is provided, the protrusion in the vehicle width direction can be suppressed.

Further, in the above configuration, the center of the crank chamber of the internal combustion engine may be biased to the left or right in the vehicle width direction, and the auxiliary machine may be provided on the side opposite to the direction in which the center of the crank chamber is biased. According to this configuration, it is possible to easily balance the engine by providing an auxiliary machine on the side opposite to the direction in which the center of the crank chamber is biased.

Further, in the above configuration, the cooling air may be guided to the auxiliary machine by the tank shroud attached to the fuel tank. According to this configuration, the auxiliary equipment can also be cooled by air.

FIG. 1 is a right side view of a motorcycle according to the first embodiment of the present invention. FIG. 2 is a front view of a motorcycle. FIG. 3 is a right side view of the unit swing engine. FIG. 4 is a cross-sectional view of the unit swing engine. FIG. 5 is a perspective view of a main part of the high-pressure fuel pump. FIG. 6 is a right side view of the cylinder portion of the motorcycle. FIG. 7 is a top view of the cylinder head of a motorcycle. FIG. 8 is a right side view of the motorcycle according to the second embodiment of the present invention. FIG. 9 is a front view of the motorcycle. FIG. 10 is a right side view of the engine of the second embodiment. FIG. 11 is a front view of the engine of the second embodiment. FIG. 12 is a rear view of a cross section of the cylinder portion of the engine. FIG. 13 is a right side view of the cylinder portion of the motorcycle.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the explanation, the directions such as front / rear / left / right and up / down are the same as the directions with respect to the vehicle body unless otherwise specified. Further, the reference numerals FR shown in each figure indicate the front of the vehicle body, the reference numerals UP indicate the upper part of the vehicle body, and the reference numerals LH indicate the left side of the vehicle body.

<First Embodiment>
FIG. 1 is a right side view of a motorcycle according to the first embodiment of the present invention. In FIG. 1, only the one on the right side is shown as a pair of left and right ones.
The motorcycle 1 is a scooter-type saddle-mounted vehicle having a low-floor step floor (flat floor) 11 on which an occupant seated on the seat 10 rests his / her feet. The motorcycle 1 has a front wheel 2 in front of a vehicle body frame (vehicle body) 12, and a rear wheel 3 which is a driving wheel is pivotally supported by a unit swing engine (internal combustion engine, engine) 13 arranged at the rear of the vehicle. ..

FIG. 2 is a front view of the motorcycle 1.
As shown in FIGS. 1 and 2, the motorcycle 1 includes a front fork 14 that is pivotally supported by the front end of the vehicle body frame 12, and the front wheel 2 is pivotally supported by the lower end of the front fork 14. The steering wheel 15 steered by the occupant is attached to the upper end of the front fork 14.
The motorcycle 1 includes a vehicle body cover 16 that covers a vehicle body such as a vehicle body frame 12.

The vehicle body frame 12 includes a head pipe 17 provided at the front end, a down frame 18 extending rearward and downward from the head pipe 17, and a pair of left and right lower frames 19 and 19 extending substantially horizontally from the lower end of the down frame 18 to the rear. A pair of left and right seat frames 20 and 20 extending rearward from the rear ends of the frames 19 and 19 are provided.
The lower frames 19 and 19 and the seat frames 20 and 20 have a pipe shape extending in the front-rear direction.

Each seat frame 20 includes a rising portion 21 extending rearward from the rear end of each lower frame 19, and a rear extending portion 22 extending from the upper end of the rising portion 21 to the rear end of the vehicle body frame 12. The rear extending portion 22 extends rearwardly with a gentler inclination than the rising portion 21.

The vehicle body frame 12 includes a cross member 23 that connects the rear ends of the lower frames 19 and 19 in the vehicle width direction, and an upper cross member (seat support stay) 24 that connects the upper portions of the rising portions 21 and 21 in the vehicle width direction. Be prepared.
Further, the vehicle body frame 12 includes a pair of left and right engine brackets 26, 26 projecting rearward from the rising portions 21 of the seat frames 20, 20.

The unit swing engine 13 is swingably supported on the engine brackets 26 and 26 via a link mechanism 48.
The unit swing engine 13 is a unit swing power unit in which an engine body 40, which is a drive source, and an arm portion 41 that supports the rear wheels 3 are integrated.
A rear suspension 29 is hung between the rear end of the unit swing engine 13 and the rear of the seat frames 20 and 20.
The rear wheel 3 is pivotally supported by the rear wheel axle 3a at the rear end of the arm portion 41.

The exhaust pipe 77 of the engine body 40 is pulled downward from the front part of the engine body 40, passes from the other side (left side) to the one side (right side) in the vehicle width direction, extends rearward to the side of the rear wheel 3. Extend. The rear end of the exhaust pipe 77 is connected to the muffler 78 on the side of the rear wheel 3.
When the unit swing engine 13 swings via the link mechanism 48, the engine body 40, the exhaust pipe 77, and the like swing integrally.
A storage box 27 capable of storing an article such as a helmet is provided between the left and right seat frames 20 and 20 above the unit swing engine 13. The sheet 10 is supported on the upper surface of the storage box 27 and covers the opening on the upper surface of the storage box 27.

A fuel tank 37 is arranged in front of the unit swing engine 13. The fuel tank 37 is arranged in front of the cross member 23 between the left and right lower frames 19 and 19. The motorcycle 1 of the present embodiment is a so-called underfloor tank scooter type vehicle (scooter type saddle type vehicle) in which the fuel tank 37 is arranged below the step floor 11. A fuel pump 38 is arranged at the rear of the fuel tank 37. The fuel pump 38 is attached to the upper part of the fuel tank 37. A low-pressure fuel hose 39 is connected to the fuel pump 38. The low-pressure fuel hose 39 is arranged on the unit swing engine 13 side. The fuel pump 38 supplies the fuel in the fuel tank 37 to the unit swing engine 13 via the low-pressure fuel hose 39.

The vehicle body cover 16 includes an upper cover 30 that covers the peripheral portion of the handle 15, a front cover 31 that covers the head pipe 17 and the down frame 18 from the front and sides, and the head pipe 17 and the down frame that are combined with the front cover 31 from the rear. It is provided with a leg shield 32 that covers 18.
Further, the vehicle body cover 16 includes an undercover 33 that covers the lower frames 19 and 19 from below, underside covers 33A and 33A that cover the lower frames 19 and 19 from the side, and a step floor that covers the lower frames 19 and 19 from above. 11 is provided. The undercover 33, the underside covers 33A, 33A and the step floor 11 cover the fuel tank 37 from the top, bottom, left and right.
Further, the vehicle body cover 16 includes a pair of left and right side covers 34, 34 that cover the seat frames 20, 20 and the storage box 27 from the side below the seat 10, and the storage box 27 and the unit swing engine 13 below the seat 10. It is provided with a center lower cover (cover under the seat) 35 that covers from the front.
Further, the motorcycle 1 includes a front fender 36 that covers the front wheels 2 from above.

FIG. 3 is a right side view of the unit swing engine 13. FIG. 4 is a cross-sectional view of the unit swing engine 13.
In the present embodiment, the engine body (internal combustion engine body) 40 provided at the front of the unit swing engine 13 is a single-cylinder 4-cycle engine. The engine body 40 includes a crankcase 43 for accommodating a crankshaft 42 extending in the vehicle width direction, and a cylinder portion 44 extending forward from the crankcase 43.
The cylinder portion 44 includes a cylinder 45, a cylinder head 46, and a head cover (cylinder head cover) 47 in this order from the crankcase 43 side.
The engine body 40 is a horizontal engine in which the cylinder axis (center of the cylinder portion) 44a of the cylinder portion 44 extends substantially horizontally in the vehicle front-rear direction. Specifically, the cylinder portion 44 extends substantially horizontally toward the front of the vehicle in a slightly upward direction when viewed from the side of the vehicle.

As shown in FIG. 4, the crankcase 43 includes a support wall 51 and a support wall 52 orthogonal to the crankshaft 42, and the crankshaft 42 is supported by the support wall 51 and the support wall 52 via bearings. The support wall 51 and the support wall 52 form a part of the crank chamber 53 in which the crankshaft 42 is housed. The center of the crank chamber 53 in the vehicle width direction is biased to the left with respect to the vehicle center line 1c.

A piston 54 is slidably housed in the cylinder 45. The piston 54 is connected to the crankshaft 42 in the crank chamber 53 via the connecting rod 55.
A combustion chamber 46a is provided at the rear of the cylinder head 46 facing the front surface of the piston 54. On the right side wall portion 67R side, the spark plug 68 is inserted from the right side of the cylinder head 46 toward the combustion chamber 46a, and the tip of the spark plug 68 faces the inside of the combustion chamber 46a. The cylinder head 46 is provided with an intake port (not shown) and an exhaust port 46b connected to the combustion chamber 46a, and the inner ends thereof are open to the combustion chamber 46a. An intake valve and an exhaust valve (not shown) for opening and closing the respective openings are provided at the inner end openings of the intake port and the exhaust port 46b (not shown).
Further, as shown in FIG. 7, the injector of the fuel injection device 130 is inserted from above the cylinder head 46 toward the combustion chamber 46a, and the tip of the injector faces the inside of the combustion chamber 46a. The fuel injection device 130 is a direct injection system.

The crankcase 43 includes a generator chamber 56 on one left and right side (right side) of the crankcase 53.
At one end of the crankshaft 42 extending into the generator chamber 56, a generator 58 that generates electricity by the rotation of the crankshaft 42 is provided. The generator 58 rotates integrally with the crankshaft 42. A cooling fan 59 is provided on the outer surface of the generator 58.

The cooling fan 59 is covered with a fan cover 81. The fan cover 81 is fastened to the crankcase so as to cover the cooling fan 59. The fan cover 81 includes a suction cylinder 82 that forms a suction port 82a. The suction cylinder 82 is arranged at the position of the cooling fan 59.
A shroud 83 that covers the cylinder 45 and the cylinder head 46 is arranged in front of the fan cover 81. The shroud 83 is composed of a pair of upper and lower cover members 84, 85 (see FIG. 3) that are connected to each other so as to cover the cylinder 45 and the cylinder head 46 in a cooperative manner. The cover members 84 and 85 are supported by the engine body 40 by being fastened to the fastening portion 81a of the fan cover 81 and the front portion of the head cover 47.

The shroud 83 has a shape that curves toward the head cover 47 on one side of the cylinder 45 and the cylinder head 46 toward the front, and forms a space between the shroud 83 and the engine body 40. The cooling air passage 86 is formed by the space between the engine body 40 and the shroud 83. The cooling fan 59 sucks in the outside air and guides the air into the shroud 83 as shown by the arrow A1, and the forced air cooling air discharged from the cooling fan 59 flows through the cooling air passage 86 as shown by the arrow A2. A plurality of cooling fins 45a are provided so as to project from the outer surface of the cylinder 45. The cooling fins 45a are arranged in the cooling air passage 86, and efficient cooling by the air flowing through the cooling air passage 86 is possible.
The fan cover 81 and the cover members 84 and 85 are each made of synthetic resin.

The cylinder head 46 is provided with a valve gear (valve gear mechanism) 63 for driving an intake valve and an exhaust valve (not shown). The valve gear 63 includes a camshaft (engine-side drive shaft) 64 arranged in parallel with the crankshaft 42, and an intake valve and an exhaust valve (not shown) driven by the camshaft 64. The head cover 47 covers the valve gear 63. The cylinder head 46 and the head cover 47 form a valve operating mechanism accommodating portion.

The camshaft 64 is rotatably supported via a bearing 62. A pair of bearings 62 are arranged in the axial direction of the camshaft 64. The camshaft 64 is driven by the crankshaft 42 via a camchain 65 that connects the camshaft 64 and the crankshaft 42.

A driven sprocket 65a is provided on the other end side of the camshaft 64. A cam chain (valve valve mechanism transmission device) 65 is wound around the driven sprocket 65a. The cam chain 65 is wound around the drive sprocket 65b of the crankshaft 42. The rotation of the crankshaft 42 is transmitted to the camshaft 64 via the cam chain 65. Every time the crankshaft 42 makes two rotations, the camshaft 64 makes one rotation.

The cylinder portion 44 includes a cam chain chamber 66 through which the cam chain 65 passes on the other end side of the cam shaft 64. The cam chain chamber (transmission chamber) 66 is provided so as to straddle the crankcase 43, the cylinder 45, and the cylinder head 46, and extends in the axial direction of the cylinder portion 44. The cam chain chamber 66 is located on the side opposite to the generator chamber 56 with respect to the crank chamber 53 in the vehicle width direction, and is on the left side (inside) of the side wall portions 67L and 67R in the left-right direction (vehicle width direction) of the cylinder portion 44. It is provided on the side wall portion 67L on the side). The side wall portions 67L and 67R include a side wall portion (side surface) of the cylinder head 46.

The crankcase 43 integrally includes a transmission case portion 70 extending rearward from a side surface portion on the side opposite to the generator chamber 56 side. The transmission case portion 70 extends from the central portion of the rear portion of the crank chamber 53 to the left side of the rear wheel 3.
The transmission case portion 70 is formed in a case shape in which the outer surface in the vehicle width direction is open, and this open portion is closed by the transmission case cover 71.
By fixing the transmission case cover 71 to the transmission case portion 70, the above-mentioned arm portion 41 is configured.

A belt-type continuously variable transmission 73, a centrifugal clutch mechanism 74, and a reduction mechanism 75 composed of a plurality of gears are provided in the hollow arm portion 41.
The driving force of the crankshaft 42 is transmitted to the rear wheels 3 via the belt-type continuously variable transmission 73, the clutch mechanism 74, and the reduction mechanism 75.

FIG. 5 is a perspective view of a main part of the high-pressure fuel pump 100. In FIG. 5, for convenience of explanation, the internal member is shown by a solid line, and the housing 101 is shown by a chain double-dashed line. The fuel flow path is not shown.
As shown in FIGS. 3 and 5, a high-pressure fuel pump (fuel pumping device) 100 is supported by the cylinder head 46 of the engine body 40. The high-pressure fuel pump 100 includes a housing (auxiliary machine housing) 101 and a pump body (auxiliary machine body) 102 supported by the housing 101.

The pump body 102 has a low pressure suction unit 103 (see FIG. 3) and a high pressure discharge unit 104 (see FIG. 3). The low-pressure suction unit 103 and the high-pressure discharge unit 104 communicate with each other via a hollow pressurizing chamber (not shown) formed inside the housing 101. The low pressure suction unit 103 is formed in a tubular shape having a suction port 103a. A low-pressure fuel hose 39 extending from the fuel tank 37 is connected to the low-pressure suction unit 103. Low-pressure fuel is supplied to the low-pressure suction unit 103 from the fuel tank 37.

The high-pressure discharge unit 104 is formed in a tubular shape having a discharge port 104a. A high-pressure fuel pipe 131 is connected to the high-pressure discharge unit 104. The high-pressure fuel pipe 131 is connected to a direct injection type fuel injection device 130 (see FIG. 7). The high-pressure fuel pump 100 sends fuel to the fuel injection device 130 at high pressure.

The pump body 102 includes a plunger 111 as shown in FIG. The plunger 111 is a shaft-shaped member extending in the direction perpendicular to the pump shaft (auxiliary drive shaft) 114. The plunger 111 is slidably supported along a cylinder portion 112 extending in a tubular shape. An eccentric cam-shaped lifter 113 is arranged on the other end 111b side of the plunger 111. The lifter 113 is rotatably and slidably supported by a pump shaft 114 extending in a direction orthogonal to the plunger 111 via a needle bearing 116. The pump shaft 114 is rotatably supported by bearings 115, 115 arranged on both sides of the lifter 113. The bearings 115 and 115 are fixed to the housing 101.
The lifter 113, the pump shaft 114, the bearings 115, 115, and the needle bearing 116 are arranged in a hollow drive chamber 117 formed inside the housing 101.

The pump shaft 114 projects outward through an opening (not shown) formed in the housing 101. The pump shaft 114 is formed in a hollow shape, and a hollow portion (hollow portion on the auxiliary drive shaft side) 114a extending in the axial direction is formed. Further, the pump shaft 114 is formed with a through hole 114b (see FIG. 4) penetrating in the radial direction. Oil can pass through the hollow portion 114a, and the oil is supplied to the needle bearing 116 through the through hole 114b, lubricates the sliding surface, and then is discharged into the drive chamber 117. A spline portion 114c is formed on the outer peripheral portion of the pump shaft 114.

A stay 106 is fixed to the housing 101. The stay 106 is formed with a diameter larger than that of the pump shaft 114, and an opening 106a through which the pump shaft 114 penetrates is formed. The drive chamber 117 communicates with the inside and outside of the housing 101 by the opening 106a.

In the fuel flow path to the fuel injection device 130, a spill valve 105 is arranged between the low pressure suction unit 103 and the pressurizing chamber (not shown) of the pump body 102. The spill valve 105 is a solenoid valve and includes a control connector 105a. The connector 105a is connected to an ECU (Electronic Control Unit) (not shown) via an electric cable (not shown). The spill valve 105 controls the valve to adjust the amount of low-pressure fuel supplied to the pressurizing chamber (not shown).

A pulsation damper 122 (see FIG. 3) is arranged on the side opposite to the plunger 111 with the pressurizing chamber (not shown) interposed therebetween. The pulsation damper 122 absorbs pressure fluctuations.

Low-pressure suction section 103, high-pressure discharge section 104, spill valve 105, pressurizing chamber (not shown), plunger 111, cylinder section 112, lifter 113, pump shaft 114, bearings 115, 115, needle bearing 116, drive chamber 117, and the like. The pump body 102 is configured by the pulsation damper 122.

Therefore, when the pump shaft 114 rotates, the plunger 111 moves according to the eccentric movement of the lifter 113, and the plunger 111 enters and retracts into the pressurizing chamber (not shown). When the plunger 111 enters the pressurizing chamber (not shown), the low-pressure fuel is compressed in the pressurizing chamber (not shown) to become a high pressure. The high-pressure fuel is supplied to the high-pressure fuel pipe 131 via the high-pressure discharge unit 104 by opening the discharge valve (not shown).

As shown in FIG. 3, the high-pressure fuel pump 100 is fixed to the cylinder head 46 via the stay 106. The stay 106 is fixed to the cylinder head 46 with bolts. The cylinder head 46 is located at the end of the engine body 40, and the high-pressure fuel pump 100 has improved assemblability with respect to the engine body 40.

The pump shaft 114 of the high pressure fuel pump 100 is coupled to the camshaft 64.
Here, the camshaft 64 is formed to be hollow, and includes a hollow portion (engine-side drive shaft-side hollow portion) 64a extending from the axial central portion to one end side. Further, the camshaft 64 is formed with a through hole 64b that penetrates in the radial direction and communicates with the hollow portion 64a. Oil is supplied to the hollow portion 64a via an oil oil passage (not shown) of the cylinder 45 or the cylinder head 46. Oil may be supplied from the through hole 64b to the hollow portion 64a. This oil is supplied by an oil pump (not shown) that is driven by receiving the rotational torque of the crankshaft 42.

The pump shaft 114 is inserted into the hollow portion 64a of the camshaft 64. An engaging portion for a spline extending in the axial direction is formed in the inner peripheral portion of the hollow portion 64a, and the spline portion 114c of the pump shaft 114 fits into the hollow portion 64a to be spline-coupled. At this time, the hollow portion 64a of the camshaft 64 and the hollow portion 114a of the pump shaft 114 communicate with each other. Therefore, the oil is supplied from the hollow portion 64a. The oil flowing into the pump shaft 114 is supplied to the needle bearing 116 of the housing 101 through the through hole 114b, lubricates the sliding surface, and then is discharged into the drive chamber 117 to lubricate the bearing 115 and the like. Then, it returns to the inside of the cylinder portion 44 from the opening 106a. That is, it constitutes a hollow portion 64a of the camshaft 64, a hollow portion 114a of the pump shaft, a through hole 114b (see FIG. 4), a drive chamber 117, an opening 106a, and an oil passage through which oil flows.

In the present embodiment, the high-pressure fuel pump 100 is attached to the cylinder head 46 and is arranged so as to be covered with the shroud 83. Further, in the present embodiment, since the high-pressure fuel pump 100 is supported by the cylinder head 46, heat is easily transferred through the cylinder head 46 to a high temperature. The high-pressure fuel pump 100 is arranged in the shroud 83 and is arranged in the cooling air passage 86. Therefore, the high-pressure fuel pump 100 can be cooled by the forced cold air by the cooling fan 59. The high-pressure fuel pump 100 is arranged at a position outside the vehicle width direction and closer to the inner wall of the shroud 83 than the cylinder block including the cylinder 45 and the cylinder head 46. As a result, the high-pressure fuel pump 100 can be cooled by the cold air flowing from the cooling fan 59 along the inner surface of the shroud 83 as shown by the arrow A2 (see FIG. 4), and the cooling efficiency is improved.

The center of the crank chamber 53 of the engine body 40 is biased to the left with respect to the vehicle center line 1c, and the high-pressure fuel pump 100 is provided on the right side of the vehicle center line 1c on the opposite side of the direction in which the center of the crank chamber is biased. Therefore, it is possible to easily balance the unit swing engine 13.

FIG. 6 is a right side view of the cylinder portion 44 of the motorcycle 1. FIG. 7 is a top view of the cylinder head 46 of the motorcycle 1. In FIGS. 6 and 7, the shroud 83 is not shown.
As shown in FIG. 6, the high-pressure fuel pump 100 is arranged at a position overlapping the rising portion 21 of the seat frame 20 when viewed from the side of the vehicle. The high-pressure fuel pump 100 is protected from scattered objects from the outside.

The unit swing engine 13 is swingably supported by the vehicle body frame 12 via a link mechanism (connecting portion) 48 provided above the unit swing engine 13.
The link mechanism 48 swings with a swing shaft 48a connected to the upper part of the crankcase 43 and a pair of left and right vehicle body side swing shafts 48b and 48b connected to the engine brackets 26 and 26 of the seat frames 20 and 20. A link member 48c for connecting the shaft 48a and the vehicle body side swing shafts 48b and 48b is provided. In other words, the swing shaft 48a is provided in the upper portion of the crankcase 43 located above the cylinder axis 44a of the cylinder portion 44, and the swing shaft 48a and the vehicle body side swing shafts 48b and 48b are provided via the link member 48c. The unit swing engine 13 is swingably supported by the vehicle body frame 12.
The swing shaft 48a and the vehicle body side swing shaft 48b are horizontal shafts extending in the vehicle width direction. The unit swing engine 13 can swing around the swing shaft 48a and the vehicle body side swing shafts 48b and 48b.
In the unit swing engine 13, the engine body 40 is swingably connected to the vehicle body frame 12 together with the arm portion (swing arm) 41 that supports the rear wheels (wheels) 3 and the rear wheel axles (axles) 3a.

The high-pressure fuel pump 100 is supported behind the front end portion (internal combustion engine front end portion) 47a of the engine body 40. In the present embodiment in which the cylinder axis 44a extends upward to the right, the front end portion (internal combustion engine front end portion) 47a corresponds to the corner portion of the front lower head cover 47 with respect to the cylinder axis 44a. The high-pressure fuel pump 100 can be prevented from protruding in the front-rear direction from the unit swing engine 13.

As shown in FIG. 4 and the like, the cylinder axis 44a is biased to the left of the vehicle center line 1c corresponding to the center portion in the width direction of the front wheels 2 and the rear wheels 3. The high-pressure fuel pump 100 is provided on the side opposite to the direction in which the cylinder axis 44a is biased, that is, on the right side. Therefore, the high-pressure fuel pump 100 is arranged on the side where space is likely to be generated, and the amount of protrusion in the vehicle width direction is suppressed.

Further, both the suction port 103a of the low-pressure suction section 103 and the discharge port 104a of the high-pressure discharge section 104 of the high-pressure fuel pump 100 face in a direction that does not project outward in the vehicle width direction, that is, toward the rear side of the unit swing engine 13. Therefore, the low-pressure fuel hose 39 extending from the low-pressure suction section 103 and the high-pressure fuel pipe 131 extending from the high-pressure discharge section 104 tend to overlap on the unit swing engine 13, as shown in FIG. Therefore, the protruding portions such as the low pressure suction portion 103 and the high pressure discharge portion 104 can be protected.

As described above, according to the first embodiment to which the present invention is applied, a cam shaft 64 rotatably supported by the engine body 40 and rotated by the rotational torque generated by the unit swing engine 13, and a high-pressure fuel. The pump 100, the housing 101 attached to the engine body 40, the pump body 102 supported by the housing 101, and the pump body 102 rotatably supported in the housing 101 so as to be coaxial with the cam shaft 64, drive the pump body 102. In the unit swing engine 13 having the pump shaft 114 and the pump shaft 114, the inside of the cam shaft 64 and the pump shaft 114 is hollow, and the hollow portion 64a of the cam shaft 64 and the hollow portion 114a of the pump shaft 114 communicate with each other and are hollow. Parts 64a and 114a are configured as oil passages. Therefore, even if the high-pressure fuel pump 100 is arranged, the vehicle width direction can be made compact and the number of parts can be reduced. Further, the cam shaft 64 and the pump shaft 114 have bearings 62 and 115, and the pump shaft 114 can be cooled and lubricated.

In the present embodiment, the high-pressure fuel pump 100 is a fuel pumping device that pumps fuel. Therefore, the high-pressure fuel pump 100, which tends to get hot because it is arranged at a position close to the cylinder head, can be effectively cooled.

Further, in the present embodiment, both the suction port 103a of the low pressure suction part 103 of the high pressure fuel pump 100 and the discharge port 104a of the high pressure discharge part 104 are oriented so as not to protrude outward in the vehicle width direction. Therefore, the protruding portions of the high-pressure fuel pump 100 such as the low-pressure suction unit 103 and the high-pressure discharge unit 104 can be protected.

Further, in the present embodiment, the camshaft 64 is the camshaft of the valve gear 63. Therefore, since the fuel injection timing is the same as the rotation cycle of the cam, the fuel injection timing can be matched with the operation timing of the valve operating mechanism. As a result, it is not necessary to provide a reduction mechanism between the engine side drive shaft and the auxiliary machine drive shaft, and the size can be reduced.

Further, in the present embodiment, the joint portion between the camshaft 64 and the pump shaft 114 has a spline structure. Therefore, the play in the circumferential direction between the camshaft 64 and the pump shaft 114 can be reduced.

Further, in the present embodiment, the high-pressure fuel pump 100 is located behind the front end portion 47a of the head cover in the front-rear direction when mounted on the vehicle. Therefore, the high-pressure fuel pump 100 can be prevented from protruding in the front-rear direction with respect to the unit swing engine 13.

Further, in the present embodiment, the high-pressure fuel pump 100 overlaps with the rising portion 21 of the vehicle body frame 12 in the side view of the vehicle. Therefore, the high-pressure fuel pump 100 can be protected by the vehicle body frame 12.

Further, in the present embodiment, the high-pressure fuel pump 100 is provided on the cylinder head 46 forming the valve operating mechanism accommodating portion for accommodating the valve operating device 63. Therefore, the assembling property of the high-pressure fuel pump 100 is improved.

Further, in the present embodiment, the center of the crank chamber 53 of the engine body 40 of the unit swing engine 13 in the vehicle width direction is biased to the left in the vehicle width direction, and the high-pressure fuel pump 100 is opposite to the direction in which the center of the crank chamber 53 is biased. It is provided on the right side, which is the side. Therefore, the high-pressure fuel pump 100 can be provided on the side opposite to the direction in which the center of the crank chamber 53 is biased, so that the unit swing engine 13 can be easily balanced.

<Second Embodiment>
FIG. 8 is a right side view of the motorcycle 201 according to the second embodiment of the present invention.
In the description of the second embodiment, the same components as those of the first embodiment are designated by the same reference numerals and the description thereof will be omitted.
In the motorcycle 201 of the second embodiment, the body frame (body) 210 supports the engine (internal combustion engine) 211 as a power unit, and the steering system 212 that steerably supports the front wheels 202 is located at the front end of the body frame 210. This is a vehicle in which a swing arm 213 that is steerably supported and supports the rear wheels 203 is provided at the rear of the vehicle body frame 210.
The motorcycle 201 is a saddle-riding vehicle in which a seat 214 on which an occupant sits straddles is provided above the rear portion of the vehicle body frame 210.

The body frame 210 includes a head pipe 215 provided at the front end of the body frame 210, a main frame 216 extending downward from the rear of the head pipe 215, and a down frame 217 extending rearward and downward from the rear of the head pipe 215. A pivot frame 218 connected to the lower end of the main frame 216, a pair of left and right seat frames 219 extending rearward from the upper part of the rear part of the main frame 216 to the rear end of the vehicle, and a seat frame 219 extending rearward from the pivot frame 218. It includes a pair of left and right subframes 220 connected to the rear portion.

FIG. 9 is a front view of the motorcycle 201.
As shown in FIGS. 8 and 9, the steering system 212 includes a steering shaft (not shown) pivotally supported by the head pipe 215, a top bridge 221 fixed to the upper end of the steering shaft, and a lower end of the steering shaft. It is provided with a bottom bridge 222 fixed to, a pair of left and right front forks 223 supported by the top bridge 221 and the bottom bridge 222, and a steering handle 224 fixed to the top bridge 221.
The front wheel 202 is pivotally supported at the lower end of the front fork 223.

The pivot frame 218 is provided with a pivot shaft 226 that penetrates the pivot frame 218 in the vehicle width direction, and the front end portion of the swing arm 213 is pivotally supported by the pivot shaft 226. The swing arm 213 includes an arm portion 213a extending rearward in pairs from the pivot shaft 226 side, and the rear wheel 203 is pivotally supported by a rear wheel axle 203a passed between the rear end portions of the arm portion 213a.
A pair of left and right rear suspensions 227 are hung between the rear portion of the arm portion 213a and the seat frame 219.

The engine 211 includes a crankcase 231 for accommodating the crankshaft 272 and a cylinder portion 232 extending upward from the front portion of the crankcase 231. A transmission (not shown) is built in the rear part of the crankcase 231.

As shown in FIG. 8, the engine 211 is arranged below the main frame 216 between the down frame 217 and the pivot frame 218 and is supported by the down frame 217 and the pivot frame 218.
The exhaust pipe 233 of the engine 211 extends rearward and downward from the exhaust port 232b (see FIG. 10) on the front right side of the cylinder portion 232. The exhaust pipe 233 extends rearward through below the engine 211 and is connected to a muffler 234 located on the right side of the swing arm 213.
The output of the engine 211 is transmitted to the rear wheels 203 by the drive chain 235. The drive chain 235 is covered by a chain case 236 provided along the left arm portion 213a.

The fuel tank 237 is supported on the front of the mainframe 216. A fuel pump 238 is arranged inside the fuel tank 237. The fuel pump 238 is attached to the bottom of the fuel tank 237. A low pressure fuel hose 239 is connected to the fuel pump 238. The low pressure fuel hose 239 is arranged on the engine 211 side. The fuel pump 238 supplies fuel from the fuel tank 237 via the low pressure fuel hose 239.

The seat 214 is supported by the seat frame 219 and extends continuously to the fuel tank 237 to the rear end of the motorcycle 201.
A pair of left and right steps 240 on which the occupant puts his / her feet are provided on the left and right sides of the lower portion of the crankcase 231.
A pair of left and right pillion step brackets 241 are provided on the left and right sides of the pivot frame 218. A pair of left and right pillion steps 242 for passengers are supported by a pillion step bracket 241.

As a body cover, the motorcycle 201 includes a front cover 245 that covers the upper part of the front fork 223 from the front, a front side cover (tank shroud) 246 that covers the front part of the body frame 210 from the side, a fuel tank 237, and a seat 214. A side cover 247 that covers the lower part of the front portion of the seat 214 and a rear side cover 248 that covers the lower portion of the rear portion of the seat 214 are provided.
The front side cover (tank shroud) 246 is arranged in front of the cylinder head 276 and includes a tank lower cover 246B that covers the lower side of the front portion of the fuel tank 237.
The side cover 247 includes an upper side cover 247A that covers the lower part of the front portion of the fuel tank 237 and the seat 214, and an underside cover 247B that covers the lower part of the upper side cover 247A.
A front fender 249 is provided above the front wheels 202.
The motorcycle 201 is provided with a front wheel braking device 250 for braking the front wheels 202 at the front of the vehicle and a rear wheel braking device 260 for braking the rear wheels 203 at the rear of the vehicle.

FIG. 10 is a right side view of the engine 211 of the second embodiment.
The engine 211 has an engine body 270 composed of a crankcase 231 and a cylinder portion 232. The cylinder portion 232 of the engine body 270 includes a cylinder 275, a cylinder head 276, and a head cover (cylinder head cover) 277 in this order from the crankcase 231 side.
The engine body 270 is an engine in which the cylinder axis (center of the cylinder portion) 232a of the cylinder portion 232 is slightly tilted forward and extends upward when viewed from the side of the vehicle.

FIG. 11 is a front view of the engine 211 of the second embodiment.
The crankcase 231 is composed of left and right divisions that are divided into two in the vehicle width direction on a plane orthogonal to the crankshaft 272 (see FIG. 10). The crankcase 231 includes a right side case 231R and a left side case 231L. A right crankcase cover 243 is supported on the right side of the right case 231R. A generator (not shown) is arranged in the space between the right case 231R and the right crankcase cover 243. A left crankcase cover 244 is supported on the left side of the left case 231L. A transmission (not shown) is arranged in the space between the left case 231L and the left crankcase cover 244.

FIG. 12 is a rear view of the cross section of the cylinder portion 232 of the engine 211.
The engine body (internal combustion engine body) 270 of the second embodiment is a single-cylinder 4-cycle engine. The basic configuration of the engine body 270 is the same as that of the engine body 40 of the first embodiment. Some of the corresponding members are designated by the same reference numerals as those in the first embodiment, and the description thereof will be omitted. The high-pressure fuel pump 100 has the same configuration as that of the first embodiment.

The cylinder head 276 is provided with a valve gear (valve gear mechanism) 293 that drives an intake valve and an exhaust valve (not shown). The valve gear 293 includes a camshaft 294 arranged in parallel with the crankshaft 272, and an intake valve and an exhaust valve (not shown) driven by the camshaft 294. The head cover 277 covers the valve gear 293. The cylinder head 276 and the head cover 277 form a valve operating mechanism accommodating portion.

The camshaft 294 is rotatably supported via a bearing 62. A pair of bearings 62 are arranged in the axial direction of the camshaft 294. A driven sprocket 65a is provided on the left side (the other end side) of the camshaft 294, and the rotation of the crankshaft 272 is transmitted to the camshaft 294 via the camchain 65 and the driven sprocket 65a. Every time the crankshaft 272 makes two rotations, the camshaft 294 makes one rotation.

A cam chain chamber 66 through which the cam chain 65 passes is formed in the cylinder portion 232. The high-pressure fuel pump 100 is arranged on the opposite side of the cam chain chamber 66, that is, on the right side (one end side) of the camshaft 294. The high-pressure fuel pump 100 is fixed to the cylinder head 276 via a stay 106. In the high-pressure fuel pump 100, the pump shaft 114 is spline-coupled to the camshaft 294 and the hollow portion 114a of the pump shaft 114 communicates with the hollow portion 294a of the camshaft 294, as in the first embodiment. Oil is supplied from the hollow portion 294a to the hollow portion 114a to lubricate the high-pressure fuel pump 100.

The motorcycle 201 has a water pump unit (second auxiliary machine) 280 for sending cooling water, a radiator 290 (see FIG. 8), and a radiator 290 from the engine body 270 side as a cooling structure for cooling the engine body 270 with cooling water. A feed-side hose (not shown) through which the cooling water flows to, a return-side hose 291 (see FIG. 11) through which the cooling water returning from the radiator 290 to the engine body 270 side, and cooling water from the water pump unit 280 to the engine body 270. 292 (see FIG. 11) and a thermoactor unit (not shown) for switching the flow path of the cooling water.

The water pump unit 280 is arranged on the opposite side of the high-pressure fuel pump 100 and the cylinder axis 232a in the vehicle width direction, that is, on the left side of the camshaft 64. The water pump unit 280 includes a housing (second auxiliary machine housing) 281. The housing 281 includes a base portion 281a and a cover portion 281b that covers the base portion 281a to form a space. The space between the base portion 281a and the cover portion 281b constitutes a water channel 281c through which cooling water passes. The base portion 281a is fixed to the cylinder head 276 via a stay (not shown).

Further, the water pump unit 280 includes a pump main body (second auxiliary machine main body) 282. The pump body 282 is supported by the housing 281. The pump body 282 has a pump shaft 284 rotatably supported within the housing 281 via bearings 283. The pump shaft 284 is arranged coaxially with the camshaft 294 and is spline-coupled to the camshaft 294. Further, the pump body 282 includes an impeller 285 that rotates together with the camshaft 294. That is, the impeller 285 is driven by the crankshaft 272 together with the pump shaft 284 via the camshaft 294.

Inside the wall of the cylinder portion 232, a water jacket 275a through which cooling water passes and a water jacket (not shown) communicating with the water jacket 275a are provided. Cooling water is sent to the water jacket 275a via the hose 292. When the crankshaft 272 rotates, the water pump unit 280 is driven, and the cooling water is pumped through the hoses 291, 292 and the like. As a result, the cooling water circulates between the radiator 290 and the engine body 270.

FIG. 13 is a right side view of the cylinder portion 232 of the motorcycle 201.
As shown in FIG. 13, in the high-pressure fuel pump 100, the stay 106 (see FIG. 5) is bolted and fixed to the cylinder head 276. Since the cylinder head 276 is located at the end of the engine body 270, the assembling property of the high-pressure fuel pump 100 to the engine body 270 is improved.
In the second embodiment, in the high-pressure fuel pump 100, the pulsation damper 122 overlaps with the lower edge 237a of the fuel tank 237 in the vehicle side view.
A tank lower cover 246B is supported in front of the high-pressure fuel pump 100. The tank lower cover 246B is supported by a fixed piece-shaped front engaging portion 237b formed on the lower edge of the fuel tank 237. The position of the front engaging portion 237b in the front-rear direction overlaps with the front end portion 277a of the engine body 270 when viewed from the side of the vehicle. A fixed piece-shaped rear engaging portion 237c is formed on the rear side of the front engaging portion 237b. An underside cover 247B (see FIG. 8) is supported on the rear engaging portion 237c.

As shown in FIG. 13, the tank lower cover 246B has an inverted L-shaped front end edge (see FIG. 9), protrudes outward in the vehicle width direction, and then gradually has a vehicle width as it goes downward. It has a front edge that slopes inward in the direction. A radiator 290 (see FIG. 8) is arranged between the left and right tank lower covers 246B. The vent 246B1 is configured by the opening shape surrounded by the radiator 290 and the inverted L-shaped front end edge of the tank lower cover 246B. The running wind is guided to the engine 211 side through the air guide port 246B1. Since the high-pressure fuel pump 100 is located at the rear of the air guide port 246B1 on the right side, the high-pressure fuel pump 100 is easily cooled by the running wind.

Further, the high-pressure fuel pump 100 is arranged behind the front end portion (internal combustion engine front end portion) 277a of the engine body 270. In the second embodiment in which the cylinder axis 232a rises to the right, the front end portion 277a corresponds to the corner portion of the front lower head cover 277 with respect to the cylinder axis 232a. Therefore, the high-pressure fuel pump 100 can be prevented from protruding in the front-rear direction from the engine 211.

As shown in FIG. 12, the cylinder axis 232a is biased to the left of the vehicle center line 201c. The high-pressure fuel pump 100 is provided on the side opposite to the direction in which the cylinder axis 232a is biased, that is, on the right side. The high-pressure fuel pump 100 is arranged on the side where space is likely to occur, and the amount of protrusion in the vehicle width direction is suppressed.

Further, in the present embodiment, as shown in FIG. 11, the left side case 231L is wider in the vehicle width direction than the right side case 231R. The center of the crank chamber of the engine body 270 is biased to the left in the vehicle width direction with respect to the vehicle center line 201c (see FIG. 9), and the high-pressure fuel pump 100 is provided on the right side opposite to the direction in which the center of the crank chamber is biased. .. Therefore, the high-pressure fuel pump 100 can be provided on the side opposite to the direction in which the center of the crank chamber is biased, so that the engine 211 can be easily balanced.

As shown in FIG. 10, both the suction port 103a of the low-pressure suction section 103 and the discharge port 104a of the high-pressure discharge section 104 of the high-pressure fuel pump 100 face in a direction that does not project outward in the vehicle width direction, that is, toward the rear side of the engine 211. ing. Therefore, the low-pressure fuel hose 239 extending from the low-pressure suction section 103 and the high-pressure fuel pipe 131 extending from the high-pressure discharge section 104 tend to overlap on the engine 211 as shown in FIG. Therefore, the protruding portions such as the low pressure suction portion 103 and the high pressure discharge portion 104 can be protected.

As described above, according to the second embodiment to which the present invention is applied, in the engine 211, the insides of the camshaft 294 and the pump shaft 114 are hollow, and the hollow portion 294a of the camshaft 294 and the pump The hollow portions 114a of the shaft 114 communicate with each other, and the hollow portions 294a and 114a are configured as oil passages. Therefore, in the second embodiment as well as in the first embodiment, even if the high-pressure fuel pump 100 is arranged, the vehicle width direction can be made compact. That is, even in the second embodiment, the configuration corresponding to the first embodiment has the same effect as that of the first embodiment.

In the second embodiment, both the high pressure fuel pump 100 and the water pump unit 280 are provided on the cylinder head 276 that forms the valve operating mechanism accommodating portion that accommodates the valve operating device 293. Therefore, the assembling property of the high-pressure fuel pump 100 and the water pump unit 280 is improved.

Further, in the second embodiment, the cooling air is guided to the high-pressure fuel pump 100 by the front side cover 246 attached to the fuel tank 237. Therefore, the high-pressure fuel pump 100 can be cooled by air.

The above-described embodiment shows only one aspect of the present invention, and can be arbitrarily modified and applied without departing from the gist of the present invention.
In each of the above embodiments, the configuration of the camshaft 64 and 294 as the engine side drive shaft has been described. However, the crankshafts 42 and 272 may be used as the engine-side drive shaft that transmits the rotational torque to the high-pressure fuel pump 100.
In the above embodiment, the configuration of the high-pressure fuel pump 100 has been described as an auxiliary machine. However, any auxiliary machine can be applied as long as it is an auxiliary machine of an internal combustion engine having an auxiliary machine side drive shaft such as a water pump or an oil pump. Accordingly, the fuel injection device 130 does not have to be a direct injection system.
In the above embodiment, the engine main body 40 and 270 have described the configuration of a single-cylinder 4-cycle engine. However, the engine body does not have to be a single cylinder engine or a four-cycle engine.

In the second embodiment, the configuration of the water pump unit 280 as the second auxiliary machine has been described. However, the second auxiliary machine may have an oil pump configuration.

In the above embodiment, the motorcycle 1 as a saddle-riding vehicle has been described as an example, but the present invention is not limited to this, and the present invention is a three-wheeled vehicle including two front wheels or two rear wheels. It can be applied to saddle-riding vehicles and saddle-riding vehicles equipped with four or more wheels.

3 Rear wheels (wheels)
3a Rear wheel axle (axle)
12 Body frame 13 Unit swing engine (internal combustion engine)
40, 270 Engine body (internal combustion engine body)
41 Swing arm 44a, 232a Cylinder center 46 Cylinder head 47, 277 Head cover (cylinder head cover)
47a, 277a front end (internal combustion engine front end)
59 Cooling fan 63, 293 Valve gear (valve mechanism)
64, 294 camshaft (engine side drive shaft)
64a, 294a Hollow part (engine side drive shaft side hollow part)
83 Shroud 100 High-pressure fuel pump (auxiliary equipment, fuel pumping device)
101 housing (auxiliary equipment housing)
102 Pump body (auxiliary machine body)
103a Intake port 104a Discharge port 114 Pump shaft (auxiliary drive shaft)
114a Hollow part (hollow part on the auxiliary drive shaft side)
211 engine (internal combustion engine)
237 Fuel tank 246 Front side cover (tank shroud)
280 Water pump unit (second auxiliary machine)

Claims (10)

An engine-side drive shaft (64, 294) that is rotatably supported by the internal combustion engine body (40, 270) and rotates by the rotational torque generated by the internal combustion engine.
Auxiliary machine (100) and
Auxiliary machine housing (101) attached to the internal combustion engine main body (40, 270) and
Auxiliary machine main body (102) supported by the auxiliary machine housing (101) and
Auxiliary drive shaft (114) that is rotatably supported in the auxiliary machine housing (101) so as to be coaxial with the engine side drive shaft (64, 294) and drives the auxiliary machine main body (102). In an internal combustion engine that has
The inside of the engine side drive shaft (64, 294) and the auxiliary machine drive shaft (114) is hollow, and the engine side drive shaft side hollow portion (64a, 294a) and the auxiliary machine drive shaft side hollow portion (114a) are hollow. An internal combustion engine that communicates with the hollow portions (64a, 294a, 114a) and is configured as an oil passage. The internal combustion engine according to claim 1, wherein the auxiliary machine (100) is a fuel pumping device (100) for pumping fuel. The internal combustion engine according to claim 2, wherein the suction port (103) and / or the discharge port (104) of the fuel pumping device (100) are oriented so as not to project outward in the vehicle width direction. The internal combustion engine according to any one of claims 1 to 3, wherein the engine-side drive shaft (64, 294) is a camshaft (64, 294) of a valve operating mechanism (63, 293). The internal combustion engine according to any one of claims 1 to 4, wherein the joint portion between the engine side drive shaft (64, 294) and the auxiliary machine drive shaft (114) has a spline structure. The internal combustion engine according to any one of claims 1 to 5, wherein the auxiliary machine (100) is located behind the front end portions (47a, 277a) of the internal combustion engine in the front-rear direction when mounted on a vehicle. The internal combustion engine according to any one of claims 1 to 6, wherein the auxiliary machine (100) overlaps with a vehicle body frame (12) in a side view of the vehicle. The center of the cylinder (44a, 232a) of the internal combustion engine (13, 211) is biased to the left or right in the vehicle width direction.
The internal combustion engine according to any one of claims 1 to 7, wherein the auxiliary machine (100) is provided on the side opposite to the direction in which the center of the cylinder portion (44a, 232a) is biased. The center of the crank chamber of the internal combustion engine (13, 211) is biased to the left or right in the vehicle width direction.
The internal combustion engine according to any one of claims 1 to 8, wherein the auxiliary machine (100) is provided on the side opposite to the direction in which the center of the crank chamber is biased. The internal combustion engine according to any one of claims 1 to 9, wherein a tank shroud (246) attached to the fuel tank (237) guides cooling air to the auxiliary machine (100).

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