WO2021192274A1

WO2021192274A1 - Internal combustion engine

Info

Publication number: WO2021192274A1
Application number: PCT/JP2020/014227
Authority: WO
Inventors: 賢小田島; 大森　謙一
Original assignee: 本田技研工業株式会社
Priority date: 2020-03-27
Filing date: 2020-03-27
Publication date: 2021-09-30

Abstract

Provided is an internal combustion engine in which an auxiliary machine is easily cooled regardless of driving and stopping of a cooling fan. The internal combustion engine comprises: an engine side driving shaft 64 that is rotatably supported by an internal combustion engine body 40 and rotates with a rotating torque generated by the internal combustion engine body 40; an auxiliary machine 100; an auxiliary machine housing 101 that is attached to the internal combustion engine body 40; an auxiliary machine body 102 that is supported by the auxiliary machine housing 101; and an auxiliary machine driving shaft 114 that is rotatably supported to be coaxial with the engine side driving shaft 64 inside the auxiliary machine housing 101 and drives the auxiliary machine body 102. The internal combustion engine 13 has a shroud 83 that covers a cylinder head 46 and a cooling fan 59 that draws the air and introduces the same into the shroud 83. A part of the auxiliary machine 100 is provided inside the shroud 83, and the other part thereof is provided outside the shroud 83.

Description

Internal combustion engine

The present invention relates to an internal combustion engine.

Conventionally, a structure in which an auxiliary machine is arranged in a forced air-cooled shroud is known (see, for example, Patent Document 1). In Patent Document 1, the entire turbocharger is arranged in the shroud to cool the entire turbocharger.

Japanese Unexamined Patent Publication No. 2000-104557

However, in the configuration in which the entire auxiliary machine is arranged in the shroud as in Patent Document 1, the volume in the shroud is reduced, so that the forced air cooling performance for the internal combustion engine may be deteriorated as the volume is reduced. In addition, after the internal combustion engine is stopped, there is residual heat of the internal combustion engine, but cooling air is not sent into the shroud. Therefore, a structure that is placed in the shroud is not suitable for parts that want to be cooled even after the internal combustion engine is stopped. ..
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 in which an auxiliary machine is easily cooled regardless of whether the cooling fan is driven or stopped.

The internal combustion engine is rotatably supported by the internal combustion engine main body (40), and the engine side drive shaft (64), which is rotated by the rotational torque generated by the internal combustion engine main body (40), an auxiliary machine (100), and the internal combustion engine. The auxiliary machine housing (101) attached to the engine main body (40), the auxiliary machine main body (102) supported by the auxiliary machine housing (101), and the engine side drive shaft 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 (64) and driving the auxiliary machine main body (102), the internal combustion engine main body (40) is It has a shroud (83) that covers the cylinder head (46) and a cooling fan (59) that sucks in outside air and guides it into the shroud (83). The other part is provided outside the shroud (83).

In the above configuration, the auxiliary machine (100) is a fuel pumping device (100) for pumping fuel, and the other side of the fuel pumping device (100) having a fuel chamber (109) through which fuel passes is the shroud (100). It may be more prominent than 83).

Further, in the above configuration, the auxiliary machine (100) is a fuel pumping device (100) for pumping fuel, and one side of the fuel pumping device (100) having the auxiliary machine drive shaft (114) is said. It may be provided in the shroud (83).

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

Further, in the above configuration, the internal combustion engine main body (40) may be swingably connected to the vehicle body frame (12) together with the swing arm (41) supporting the wheels (3) and the axle (3a).

Further, in the above configuration, the auxiliary machine (100) may be located behind the front end portion (47a) 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 auxiliary machine (100) may be provided on the cylinder head cover (47) forming the valve operating mechanism accommodating portion for accommodating the valve operating mechanism (63).

Further, in the above configuration, at least one of the connector (105a), the suction port (103) or the discharge port (104) provided in the auxiliary machine (100) may protrude from the shroud (83).

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 main body. It has an auxiliary machine main body supported by an auxiliary 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 drives the auxiliary machine main body. In an internal combustion engine, the internal combustion engine main body has a shroud that covers a cylinder head and a cooling fan that sucks in outside air and guides the air into the shroud. It is provided outside the shroud. According to this configuration, hot air is trapped inside the shroud after the internal combustion engine is stopped. Therefore, the part of the auxiliary equipment that is desired to be cooled even after the internal combustion engine is stopped is provided outside the shroud, so that the part to be cooled is cooled by the outside air. be able to.

In the above configuration, the auxiliary machine is a fuel pumping device for pumping fuel, and the other side of the fuel pumping device having a fuel chamber through which fuel passes may protrude from the shroud. According to this configuration, the other side of the fuel pumping device having the fuel chamber is exposed to the outside air, and the fuel can be cooled even after the internal combustion engine is stopped.

Further, in the above configuration, the auxiliary machine is a fuel pumping device for pumping fuel, and one side of the fuel pumping device having the auxiliary machine drive shaft may be provided in the shroud. According to this configuration, one side of the fuel pumping device having an auxiliary drive shaft that generates heat when the internal combustion engine is driven can be positively cooled by the cooling air of the cooling fan during engine operation in which relatively heat is generated. can.

Further, in the above configuration, the engine side drive shaft may be a camshaft of a valve operating mechanism. According to this configuration, the fuel injection timing can be adjusted to the rotation of the camshaft.

Further, in the above configuration, the internal combustion engine main body may be swingably connected to the vehicle body frame together with the swing arm supporting the wheels and axles. According to this configuration, the engine can be cooled more effectively by providing a cooling fan in the scooter type saddle type vehicle.

Further, in the above configuration, the auxiliary machine may be located behind the front end of the internal combustion engine in the front-rear direction when mounted on the vehicle. According to this configuration, it is possible to prevent the internal combustion engine from protruding in the front-rear direction even if an auxiliary machine is provided.

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 from the side of the vehicle by the vehicle body frame.

Further, in the above configuration, the auxiliary machine may be provided on the cylinder head cover forming the valve operating mechanism accommodating portion for accommodating the valve operating mechanism. According to this configuration, since the cylinder head cover is located at the end of the internal combustion engine, the auxiliary machine can be easily assembled to the internal combustion engine.

Further, in the above configuration, at least one of the connector, the suction port or the discharge port provided in the auxiliary machine may protrude from the shroud. According to this configuration, at least one of the cable connector connected to the connector provided on the auxiliary machine, the fuel pipe connected to the suction port, or the fuel pipe connected to the discharge port is attached and detached outside the shroud. It is possible to make it easy to put on and take off.

FIG. 1 is a right side view of a motorcycle according to an 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 left side view of the unit swing engine. FIG. 5 is a sectional view taken along line VV of FIG. FIG. 6 is a sectional view taken along line VI-VI of FIG. FIG. 7 is a perspective view of the cylinder portion of the unit swing engine as viewed from the front upper side.

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.

FIG. 1 is a right side view of the motorcycle 1 according to the 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-type 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 front wheel axle 2a at the lower end of the front fork 14. NS. 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 (fuel pipe) 39.

The vehicle body cover 16 includes an upper cover 30 that covers the peripheral portion of the steering wheel 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 left side view of the unit swing engine 13. FIG. 5 is a sectional view taken along line VV of FIG.
In the present embodiment, the engine body (internal combustion engine body) 40 (see FIG. 5) 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 (see FIG. 5) extending in the vehicle width direction, and a cylinder portion 44 extending forward from the crankcase 43.
As shown in FIG. 5, 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.
As shown in FIG. 3, 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. 5, 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.

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 46c (see FIG. 4) and an exhaust port 46b connected to the combustion chamber 46a, and the inner ends thereof are open to the combustion chamber 46a. The inner end openings of the intake port 46c and the exhaust port 46b are provided with an intake valve and an exhaust valve (not shown) that open and close the respective openings.
An injector of the fuel injection device 130 is inserted below the spark plug 68 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 crank chamber 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 43 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 covers the cylinder 45 and the cylinder head 46. The shroud 83 of the present embodiment is composed of a combined structure of a plurality of covers. As shown in FIG. 3, the shroud 83 includes a rear lower cover 84 that covers the cylinder 45 from below, a rear upper cover 85 that covers the cylinder 45 from above, a front lower cover 86 that covers the cylinder head 46 from below, and a cylinder. A front upper cover 87 that covers the head 46 from above and a pump cover 88 (see FIG. 4) that covers the high-pressure fuel pump 100 supported by the cylinder portion 44 are provided.

The rear lower cover 84 and the rear upper cover 85 are fastened and integrated by a fastening member 83b (see FIG. 3) extending vertically. The rear lower cover 84 and the rear upper cover 85 are fastened to the front end of the fan cover 81 by a fastening member 83a.

A front lower cover 86, a front upper cover 87, and a pump cover 88 are arranged in front of the rear lower cover 84 and the rear upper cover 85. The front lower cover 86, the front upper cover 87, and the pump cover 88 form the front portion of the shroud 83.
The front lower cover 86, the front upper cover 87, and the pump cover 88 are fastened to the engine body 40 by a fastening member 83c (see FIG. 3) or the like.

The shroud 83 is formed with a wind guide portion 89 having a U-shaped cross section that protrudes to the right. The rear end of the wind guide 89 is formed corresponding to the vertical width of the fan cover 81, and is connected to the opening of the fan cover 81. In the right side view shown in FIG. 3, the width of the wind guide portion 89 becomes narrower as it moves forward. Further, in the cross-sectional view shown in FIG. 5, the wind guide portion 89 is curved so as to approach the cylinder axis 44a side as it advances forward.

A cooling air passage 89a is formed by a hollow space between the air guide portion 89 of the shroud 83 and the engine body 40. The cooling fan 59 sucks the outside air as shown by the arrow A1 and guides it into the shroud 83, and the cooling air for forced air cooling discharged from the cooling fan 59 directs the cooling air passage 89a toward the cylinder portion 44 as shown by the arrow A2. Flow. The cooling air guided to the cylinder portion 44 flows forward while crossing the outer periphery of the cylinder portion 44 in the shroud 83 and is exhausted. A plurality of cooling fins 45a are provided so as to project from the outer surface of the cylinder 45. The cooling fins 45a can be efficiently cooled by the cooling air flowing through the cooling air passage 89a.

The cylinder head 46 is provided with a valve gear (valve 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. 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. The camshaft 64 is driven by the crankshaft 42 via a camchain 65 that connects the camshaft 64 and the crankshaft 42. Every time the crankshaft 42 makes two rotations, the camshaft 64 makes one rotation.

The cylinder portion 44 is provided with a cam chain chamber (transmission chamber) 66 through which the cam chain 65 passes on the other end side of the cam shaft 64. The cam chain 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 opposite to the generator chamber 56 in the vehicle width direction. 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. 6 is a sectional view taken along line VI-VI of FIG.
As shown in FIGS. 5 and 6, a high-pressure fuel pump (fuel pumping device) 100 is attached to the cylinder portion 44 of the engine body 40. In the present embodiment, the high-pressure fuel pump 100 is fixed to the left side surface of the head cover 47. As a result, the high-pressure fuel pump 100 is arranged on the left side surface of the head cover 47 and the cylinder head 46. 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 high-pressure fuel pump 100 has a low-pressure suction unit 103 and a high-pressure discharge unit 104. The low-pressure suction unit 103 and the high-pressure discharge unit 104 communicate with each other via a hollow pressure chamber 108 formed inside the housing 101. The low-pressure suction unit 103, the high-pressure discharge unit 104, and the pressurizing chamber 108 form a flow path (fuel chamber) 109 (see FIG. 6) through which fuel passes.

The low-pressure suction unit 103 is formed in a cylindrical shape having a suction port, and protrudes rearward. A low-pressure fuel hose 39 (see FIG. 1) extending from the fuel tank 37 (see FIG. 1) 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 by the fuel pump 38 (see FIG. 1).

As shown in FIG. 4, the high-pressure discharge unit 104 is formed in a cylindrical 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. 5). The high-pressure fuel pump 100 sends fuel to the fuel injection device 130 at high pressure.

As shown in FIG. 6, the pump body 102 includes a shaft-shaped plunger 111. The plunger 111 extends in the direction perpendicular to the pump shaft (auxiliary drive shaft) 114. The plunger 111 is slidably supported along the cylindrical cylinder portion 112. An eccentric cam-shaped lifter 113 is arranged on one end 111b side of the plunger 111. The lifter 113 is rotatably and slidably supported on the pump shaft 114 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.

As shown in FIG. 5, the pump shaft 114 projects into the cylinder head 46 from the drive chamber 117 of the housing 101 through the opening 101a formed in the housing 101. A spline portion 114c is formed on the outer peripheral portion of the pump shaft 114. The pump shaft 114 is rotatably supported in the housing 101 so as to be coaxial with the cam shaft 64, and drives the pump body 102.

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 the other end side. The pump shaft 114 of the high-pressure fuel pump 100 is inserted into the hollow portion 64a of the camshaft 64. A spline structure extending in the axial direction is formed on the inner peripheral portion of the hollow portion 64a. The spline portion 114c of the pump shaft 114 fits into the hollow portion 64a, and the pump shaft 114 and the cam shaft 64 are spline-coupled. As a result, the pump shaft 114 rotates integrally with the camshaft 64. Therefore, in the high-pressure fuel pump 100, the fuel injection timing can be the same as the rotation of the camshaft 64, and once every two rotations of the crankshaft 42. Perform injection.

In the fuel flow path 109 (see FIG. 6) of the high-pressure fuel pump 100, a spill valve 105 (see FIG. 4) is arranged between the low-pressure suction unit 103 and the pressurizing chamber 108 of the pump body 102. As shown in FIG. 4, the spill valve 105 is a solenoid valve and includes a control connector 105a. A cable 141 is connected to the connector 105a via the connector 141a. The cable 141 is connected to an EDU (Electronic Drive Unit) and an ECU (Electronic Control Unit) (not shown). The spill valve 105 controls the valve to adjust the amount of low-pressure fuel supplied to the pressurizing chamber 108.

As shown in FIG. 6, a damper accommodating portion 121 is formed on the left side with respect to the pressurizing chamber 108. The housing 101 portion on which the damper accommodating portion 121 is formed protrudes in the vehicle width direction from the housing 101 portion on which the cylinder portion 112 is formed. The damper accommodating portion 121 is recessed toward the pressurizing chamber 108 side. In the damper accommodating portion 121, the left opening 121a is closed by the closing member 123. A pulsation damper 122 (see FIG. 3) is arranged in the damper accommodating portion 121. The pulsation damper 122 absorbs fluctuations in fuel pressure.

Low pressure suction part 103, high pressure discharge part 104, spill valve 105, pressure chamber 108, plunger 111, cylinder part 112, lifter 113, pump shaft 114,

bearings

115, 115, needle bearing 116, drive chamber 117, pulsation damper 122 The pump body 102 is configured by the above.

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 108. When the plunger 111 enters the pressurizing chamber 108, the low-pressure fuel is compressed in the pressurizing chamber 108 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.

FIG. 7 is a perspective view of the cylinder portion 44 of the unit swing engine 13 as viewed from the front upper side.
The front of the cylinder portion 44 is surrounded by a front lower cover 86, a front upper cover 87, and a pump cover 88 of the shroud 83. The front lower cover 86, the front upper cover 87, and the pump cover 88 constitute the front portion of the shroud 83 of the present embodiment. The front portion of the shroud 83 has a substantially square cylindrical cross section.

Specifically, the front upper cover 87 includes a flat plate-shaped upper wall portion 87a extending in the vehicle width direction, a flat plate-shaped right wall portion 87b extending downward from the right end of the upper wall portion 87a, and a left end of the upper wall portion 87a. It is provided with a flat plate-shaped left wall portion 87c extending downward from the surface. Here, the cylinder head 46 is formed in a substantially prismatic shape when viewed from the direction along the cylinder axis 44a (see FIG. 6). In the front upper cover 87 of the shroud 83, the upper wall portion 87a is arranged along the upper surface of the cylinder head 46, the right wall portion 87b is arranged along the right surface of the cylinder head 46, and the left wall portion 87c is arranged along the cylinder head 46. It is placed along the left side of. The left wall portion 87c is located between the cylinder head 46 and the high-pressure fuel pump 100 in the cylinder axis view (see FIG. 6).

A notch-shaped opening 87a1 is formed in the upper wall portion 87a. Through the opening 87a1, the intake pipe of the intake port 46c projects upward. Further, a plug cord (not shown) connected to the spark plug 68 and a high-pressure fuel pipe 131 (see FIG. 4) connected to the injector of the fuel injection device 130 are arranged from the outside to the inside of the shroud 83 through the opening 87a1. Be searched.

The front lower cover 86 of the shroud 83 has a flat plate-shaped lower wall portion 86a extending in the vehicle width direction, a flat plate-shaped right wall portion 86b extending upward from the left end of the lower wall portion 86a, and a flat plate-shaped lower wall portion 86a extending upward from the left end of the lower wall portion 86a. It is provided with a bent plate-shaped left wall portion 86c erected upward.
The lower wall portion 86a extends from the right end of the cylinder head 46 to below the high-pressure fuel pump 100 projecting to the left from the cylinder head 46. The right wall portion 86b is arranged along the right surface of the cylinder head 46. The left wall portion 86c is bent so as to avoid the high pressure fuel pump 100.

At the lower left of the front lower cover 86, a flat plate-shaped front wall 86d extending upward from the front left end of the lower wall 86a and overlapping the drive chamber 117 of the high-pressure fuel pump 100 is formed in the cylinder axis view. ing. The front wall portion 86d has an inverted L shape when viewed from the cylinder axis. On the left side of the front wall portion 86, a left wall portion 86c is formed along the bent left end edge of the front wall portion 86d. The front lower cover 86 is connected to the rear lower cover 84 behind the left wall portion 86c via the rear wall portion 86e (see FIG. 4).

The pump cover 88 is arranged above the left wall portion 86c, the front wall portion 86d, and the rear wall portion 86e and the left wall portion 86c. The pump cover 88 includes a flat upper wall portion 88a, a left wall portion 88c connected to the left end of the upper wall portion 88a, a front wall portion 88d connected to the front end of the upper wall portion 88a, and an upper wall portion 88a. It is provided with a rear wall portion 88e (see FIG. 4) connected to the rear end. The left wall portion 88c of the pump cover 88 is connected to the left wall portion 86c of the front lower cover 86. The front wall portion 88d of the pump cover 88 is connected to the front wall portion 86d of the front lower cover 86. The rear wall portion 88e of the pump cover 88 is connected to the rear wall portion 86e of the front lower cover 86. In the present embodiment, the upper wall portion 88a of the pump cover 88 is arranged between the pressurizing chamber 108 and the drive chamber 117, and the tip end (right end) of the upper wall portion 88a is the left wall of the front upper cover 87. It is close to the part 87c. The upper wall portion 88a overlaps with the cylinder portion 102 in the cylinder axis view. The upper wall portion 88a is arranged below the damper accommodating portion 121.

The lower wall portion 86a, the left wall portion 86c, the front wall portion 86d, and the rear wall portion 86e of the front lower cover 86, and the upper wall portion 88a, the left wall portion 88c, the front wall portion 88d, and the pump cover 88. With the rear wall portion 88e, the shroud 83 is formed with a pump accommodating portion 83d having a shape bulging on the other side in the vehicle width direction. The pump accommodating portion 83d is covered with the drive chamber 117 side (one side in the axial direction of the high pressure fuel pump 100, a part) of the high pressure fuel pump 100. Therefore, (the shroud 83 makes it easier for the cooling air to be guided to the drive chamber 117 side of the high-pressure fuel pump 100, and the shroud 83 protects the cooling air.

A notch-shaped opening 88a1 is formed in the upper wall portion 88a of the pump cover 88. Through the opening 88a1, the flow path 109 side of the high-pressure fuel pump 100 (the other side in the axial direction of the high-pressure fuel pump 100, the other portion) protrudes. Specifically, the spill valve 105, the damper accommodating portion 121, the low-pressure suction portion 103 (see FIG. 7), and the high-pressure discharge portion 104 are arranged so as to project upward with respect to the shroud 83. Since the connector 105, the low pressure suction part 103, and the high pressure discharge part 104 are exposed to the outside of the shroud 83, the connector 141a of the cable 141 connected to the connector 105a can be attached and detached, and the low pressure connected to the low pressure suction part 103. The attachment / detachment of the fuel hose 39 and the attachment / detachment of the high-pressure fuel pipe 131 connected to the high-pressure protrusion 104 are facilitated.

Here, since the high-pressure fuel pump 100 is arranged close to the cylinder head 46, heat is easily transferred through the cylinder head 46 to a high temperature. In particular, the drive chamber 117 side of the high-pressure fuel pump 100 including the pump shaft 114 tends to generate heat due to the drive of the pump shaft 114. In the present embodiment, since the drive chamber 117 side of the high-pressure fuel pump 100 is arranged in the shroud 83 through which the cooling air flows, the high-pressure fuel pump 100 can be cooled by the cooling air.

On the other hand, in the shroud 83, the cooling fan 59 is stopped after the engine body 40 is stopped, and hot air is likely to be trapped in the shroud 83 due to the residual heat of the engine body 40. On the other hand, in the present embodiment, the flow path 109 side of the high-pressure fuel pump 100 protrudes from the shroud 83 and is exposed to the outside. Therefore, even if the cooling fan 59 is stopped, the flow path 109 side of the high-pressure fuel pump 100 is easily cooled by the outside air, and the fuel in the flow path 109 is difficult to vaporize.
Therefore, in the present embodiment, when the engine body 40 is driven, the drive chamber 117 side, which tends to become hot due to driving, can be cooled by forced air cooling, and when the engine body 40 is stopped, the flow path 109 side through which fuel flows is cooled by the outside air. It is possible to suppress the vaporization of fuel.

As shown in FIGS. 1 and 3, 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.
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. By providing the cooling fan 59 in the scooter type motorcycle 1, the engine body 40 can be cooled more effectively.

As shown in FIG. 4, 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. In the present embodiment, the high-pressure fuel pump 100 as a whole is provided above the lower end 21A of the rising portion 21. The high-pressure fuel pump 100 is protected from scattered objects from the outside. In particular, the other side portion of the high pressure fuel pump 100 projecting to the outside of the shroud 83 can be effectively protected.

The high-pressure fuel pump 100 is located behind the cooling fins (front end of the internal combustion engine) 47a of the head cover 47 at the front end of the engine body 40. The cooling fins 47a of the head cover 47 project forward from the shroud 83. In the present embodiment in which the cylinder axis 44a extends upward to the right, the front end of the engine body 40 corresponds to the corner portion of the front lower cooling fin 47a with respect to the cylinder axis 44a. Even if the high-pressure fuel pump 100 is provided, it is possible to prevent the unit swing engine 13 from protruding in the front-rear direction.

In this embodiment, the high pressure fuel pump 100 is fixed to the head cover 47. The head cover 47 is located at the end of the engine body 40. Therefore, the high-pressure fuel pump 100 has improved assemblability with respect to the engine body 40.

As described above, according to the present embodiment to which the present invention is applied, the cam shaft 64 rotatably supported by the engine body 40 and rotated by the rotational torque generated by the engine body 40, and the high-pressure fuel pump 100 , The housing 101 attached to the engine body 40, the pump body 102 supported by the housing 101, and the pump shaft rotatably supported in the housing 101 so as to be coaxial with the cam shaft 64 and drive the pump body 102. In an internal combustion engine having 114, the engine body 40 has a shroud 83 that covers the cylinder head 46 and a cooling fan 59 that sucks in outside air and guides the air into the shroud 83, and the high-pressure fuel pump 100 partially shrouds. It is provided inside the 83, and the other part is provided outside the shroud 83. Therefore, since hot air is trapped inside the shroud 83 after the engine body 40 of the unit swing engine 13 is stopped, the portion of the high-pressure fuel pump 100 that is desired to be cooled even after the engine body 40 is stopped is provided outside the shroud 83 for cooling. The desired part can be cooled by the outside air.

In the present embodiment, the high-pressure fuel pump 100 is a high-pressure fuel pump 100 that pumps fuel, and the other side of the high-pressure fuel pump 100 having a flow path 109 through which fuel passes protrudes from the shroud 83. Therefore, the other side of the high-pressure fuel pump 100 having the flow path 109 in the axial direction can be brought into contact with the outside air to cool the fuel even after the engine body 40 is stopped.

In the present embodiment, the high-pressure fuel pump 100 is a high-pressure fuel pump 100 that pumps fuel, and one side of the high-pressure fuel pump 100 having a pump shaft 114 is provided in a shroud 83. Here, since the pump shaft 114 tends to generate heat only during rotation, there is little need to cool it with the outside air after the engine body 40 is stopped. Therefore, by having the configuration of the present embodiment, one side in the axial direction of the high-pressure fuel pump 100 having the pump shaft 114 that generates heat when the engine body 40 is driven is cooled by a cooling fan during engine operation in which relatively heat is generated. It can be positively cooled by the cooling air of 59.

In this embodiment, the engine-side drive shaft is the camshaft 64 of the valve gear 63. Therefore, the fuel injection timing can be adjusted to the rotation of the camshaft 64.

In the present embodiment, the engine body 40 is swingably connected to the vehicle body frame 12 together with the arm portion 41 that supports the rear wheels 3 and the rear wheel axles 3a. Therefore, by providing the cooling fan 59 in the scooter-type saddle-riding vehicle 1, the engine body 40 can be cooled more effectively.

In this embodiment, the joint between the camshaft 64 and the pump shaft 114 has a spline structure. According to this configuration, the cam shaft 64 and the pump shaft 114 can be firmly fixed while reducing play in the circumferential direction.

In the present embodiment, the high-pressure fuel pump 100 is located behind the cooling fins 47a of the head cover 47 in the front-rear direction when mounted on the vehicle. According to this configuration, the high-pressure fuel pump 100 can prevent the unit swing engine 13 from protruding in the front-rear direction.

In the present embodiment, the high-pressure fuel pump 100 overlaps with the vehicle body frame 12 when viewed from the side of the vehicle. According to this configuration, the high-pressure fuel pump 100 can be protected from the vehicle side by the vehicle body frame 12.

In the present embodiment, the high-pressure fuel pump 100 is provided on the head cover 47 forming the valve operating mechanism accommodating portion for accommodating the valve operating device 63. Therefore, since the head cover 47 is located at the end of the unit swing engine 13, the high-pressure fuel pump 100 can be easily assembled to the unit swing engine 13.

In the present embodiment, the connector 105a provided on the high-pressure fuel pump 100, the low-pressure suction unit 103, and the high-pressure discharge unit 104 project from the shroud 83. Therefore, the connector 141a of the cable 141 connected to the connector 105a provided on the high-pressure fuel pump 100, the low-pressure fuel hose 39 connected to the low-pressure suction unit 103, and the fuel pipe 131 connected to the high-pressure discharge unit 104 are shrouded. Since it can be attached and detached outside the 83, it can be easily attached and detached.

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 the above embodiment, the configuration of the camshaft 64 as the engine side drive shaft has been described. However, the crankshaft 42 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 has 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 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 Engine body (internal combustion engine body)
41 Arm part (swing arm)
46 Cylinder head 47 Head cover (Cylinder head cover)
47a Front end (front end of internal combustion engine)
59 Cooling fan 63 Valve gear (valve mechanism)
64 Camshaft (engine side drive shaft)
83 Shroud 100 High-pressure fuel pump (auxiliary equipment, fuel pumping device)
101 housing (auxiliary equipment housing)
102 Pump body (auxiliary machine body)
103 Low pressure suction part (suction port)
104 High-pressure discharge part (discharge port)
105a connector 114 pump shaft (auxiliary drive shaft)

Claims

An engine-side drive shaft (64) rotatably supported by the internal combustion engine body (40) and rotated by the rotational torque generated by the internal combustion engine body (40).
Auxiliary machine (100) and
Auxiliary machine housing (101) attached to the internal combustion engine main body (40) and
Auxiliary machine main body (102) supported by the auxiliary machine housing (101) and
The auxiliary machine housing (101) has an auxiliary machine drive shaft (114) that is rotatably supported so as to be coaxial with the engine side drive shaft (64) and drives the auxiliary machine main body (102). In the internal combustion engine
The internal combustion engine main body (40) has a shroud (83) that covers the cylinder head (46) and a cooling fan (59) that sucks in outside air and guides the air into the shroud (83).
An internal combustion engine characterized in that a part of the auxiliary machine (100) is provided inside the shroud (83) and the other part is provided outside the shroud (83).
The auxiliary machine (100) is a fuel pumping device (100) for pumping fuel.
The internal combustion engine according to claim 1, wherein the other side of the fuel pumping device (100) having a fuel chamber (109) through which fuel passes protrudes from the shroud (83).
The auxiliary machine (100) is a fuel pumping device (100) for pumping fuel.
The internal combustion engine according to claim 1 or 2, wherein one side of the fuel pumping device (100) having the auxiliary drive shaft (114) is provided in the shroud (83).
The internal combustion engine according to claim 2 or 3, wherein the engine-side drive shaft (64) is a camshaft (64) of a valve operating mechanism (63).
Claims 1 to 4, wherein the internal combustion engine main body (40) is swingably connected to a vehicle body frame (12) together with a swing arm (41) that supports a wheel (3) and an axle (3a). The internal combustion engine according to any one of the above.
The internal combustion engine according to any one of claims 1 to 5, wherein the auxiliary machine (100) is located behind the front end portion (47a) 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 auxiliary machine (100) is provided in any one of claims 1 to 7, wherein the auxiliary machine (100) is provided on a cylinder head cover (47) forming a valve operating mechanism accommodating portion for accommodating the valve operating mechanism (63). The described internal combustion engine.
Claims 1 to 8, wherein at least one of the connector (105a), the suction port (103), or the discharge port (104) provided in the auxiliary machine (100) protrudes from the shroud (83). The internal combustion engine according to any one item.