JP2855289B2 - Auxiliary drive of air / fuel injection engine - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel injection engine in which air and fuel are respectively injected into a combustion chamber, and relates to an air pump and an air / fuel injection engine that drives a fuel pump. The present invention relates to an accessory driving device.

[Conventional technology]

2. Description of the Related Art Conventionally, there is a vehicle engine such as a motorcycle engine that injects a mixture of air and fuel into a combustion chamber in order to obtain clean exhaust gas and improve fuel efficiency. In this type of fuel injection engine, a cylinder is provided with a fuel chamber fuel injection device, and air and fuel are pressure-fed to the combustion chamber fuel injection device by an air pump and a fuel pump, respectively. When the fuel injection engine is applied to a motorcycle, the air pump and the fuel pump are mechanically driven by the engine because the power supply capacity of the motorcycle is small.

[Problems to be Solved by the Invention] However, in such mechanical air pumps and fuel pumps, when the engine is in a low rotation range such as when starting the engine, the air pressure and the fuel pressure are quickly increased to a predetermined pressure. Can not. For this reason, this type of conventional engine is difficult to start.

[Means for solving the problem]

The auxiliary drive device for an air-fuel injection engine according to the present invention includes an air pump and a fuel pump that inject air and fuel into a combustion chamber of the engine, respectively. It is connected to the crankshaft, and the one with the larger reduction ratio of the two drive paths is
A drive shaft connected to the air pump and fuel pump is connected via a one-way clutch, and the smaller reduction ratio transmits power when the engine speed is low and reaches a high speed range. In this case, the power is connected to the drive main shaft via power switching means for shutting off the power when the power is turned off.

(Operation)

The air pump and the fuel pump rotate at a high speed when the engine speed is in a low speed range, and rotate at a low speed when the engine speed is in a high speed range.

〔Example〕

Hereinafter, an embodiment of the present invention will be described in detail with reference to FIGS.

1 is a side view of an air / fuel injection engine according to the present invention, FIG. 2 is a sectional view taken along line II-II in FIG. 1, FIG. 3 is a sectional view taken along line III-III in FIG. FIG. 5 is a longitudinal sectional view of the fuel pump, and FIG. 5 is an exploded perspective view of a pin clutch constituting power switching means. In these figures, 1
Is an air / fuel injection engine, and this engine 1 is a two-stroke engine for a motorcycle. Reference numeral 2 denotes a crankcase of the engine 1, reference numeral 3 denotes a cylinder block, and reference numeral 4 denotes a cylinder head. The cylinder head 4 is provided with an ignition plug 5 and a combustion chamber fuel injection device 7 for mixing and injecting air and fuel into the combustion chamber 6. Also,
In the combustion chamber fuel injection device 7, a combustion chamber fuel injection injector 8 is attached at a predetermined angle to the front of the engine with respect to the device body.

Reference numeral 9 denotes a crankshaft rotatably provided in the crankcase 2, and reference numeral 10 denotes a piston connected to the crankshaft 9 via a connecting rod 11. Reference numeral 12 denotes a reed valve mounted on an intake passage of the crankcase 2, reference numeral 13 denotes an intake pipe connected to the intake passage, and an intake pipe fuel injector 14 for injecting fuel into the intake passage. Is installed. The upstream end of the intake pipe 14 is communicated with an air cleaner (not shown) through a throttle valve (not shown). By opening and closing the throttle valve, the flow rate of air guided to the intake passage is controlled. It is configured to be.

Reference numeral 15 denotes a main shaft of the engine 1. The main shaft 15 is connected to the crankshaft 9 via a reduction gear 16 and a multi-plate clutch 17.
It is connected to. The reduction gear 16 is rotatably supported by the main shaft 15 and meshes with a small-diameter gear 9 a provided at the shaft end of the crankshaft 9. The drive side of the multi-plate clutch 17 is connected to the reduction gear 16, and the driven side is connected to the main shaft 15. That is, when the multi-plate clutch 17 is in the engaged state, the rotation of the crankshaft 9 is transmitted to the main shaft 15 via the small-diameter gear 9a, the reduction gear 16, and the multi-plate clutch 17.
Reference numeral 18 denotes an output shaft connected to the main shaft 15 via a transmission 19. The output shaft 18 is provided with a drive sprocket (not shown) for driving rear wheels.

20 is a balancer and this balancer 20 is a crankcase 2
The balancer gear 22 provided on the balancer shaft 20a meshes with the large-diameter gear 9b of the crankshaft 9. The balancer gear 22 and the large-diameter gear 9b have the same diameter, and the balancer 20 is configured to rotate at the same speed as the crankshaft 9. Reference numeral 23 denotes a pump driving gear for driving a pump crankshaft of an air pump to be described later, and is coupled to the shaft end of the balancer shaft 20a.

31 is an air pump for pumping air to the combustion chamber fuel injection device 7 of the engine 1 via an air hose 32. 33 is a combustion chamber fuel injector 8 and an intake pipe fuel injection injector of the combustion chamber fuel injection device 7. 14 to fuel hose
A fuel pump for pumping fuel through 34. The air pump 31 and the fuel pump 33 are mounted on the upper right portion of the crankcase 2 and substantially above the main shaft 15, respectively. The air pump 31 is mounted on the crankcase 2, and the fuel pump 33 is mounted on the crankcase 2. The case 2 is fixed to a crankcase cover 35 that covers the right side of the case 2.
Reference numeral 36 denotes an air supply hose for connecting the air inlet of the air pump 31 and an air cleaner (not shown), and 37 denotes an oil supply hose for connecting the fuel inlet of the fuel pump 33 and a fuel tank (not shown). is there.

The air pump 31 is a positive displacement pump in which a pump piston 39 reciprocates in a pump cylinder 38. The pump piston 39 is connected to a pump crankshaft 41 via a connecting rod 40. The pump cylinder 38 is a crankcase 2
A cylinder head 38a having a suction valve 42 and a discharge valve 43 is fixed to an upper portion thereof. The air supply hose 36 communicates with the intake port of the cylinder head 38a, and the air hose 32 communicates with the discharge port. Although FIG. 2 illustrates that the air hose 32 communicates with the intake port where the intake valve 42 is located, the air hose 32 communicates with a discharge port (not shown). The pump crankshaft 41 has a crank web 41a formed at one end of a shaft portion, and is rotatably supported by the crankcase 2 and the crankcase cover 35 via bearings 44 and 45. The pump crankshaft 41
Is mounted on the crankcase 2 so that its axis is parallel to that of the crankshaft 9. A large-diameter portion 41b and a small-diameter portion 41c are formed in the shaft portion of the pump crankshaft 41. A bearing 44 is provided in the large-diameter portion 41b, and a bearing 45 is provided in the small-diameter portion 41c.
Are fitted respectively. Further, a through hole 41d penetrating the pump crankshaft 41 along the longitudinal direction is formed in the axial center portion of the pump crankshaft 41, and a pin clutch as a power switching means is provided in the through hole 41d. The constituent sliding rod 46 is slidably fitted. The crank web 41a and the large diameter portion 41b in the through hole 41d
Is formed in a series of engagement grooves 41e in which the pins 47 of the sliding rod 46 are slidably fitted. This engagement groove 4
1e is formed over a part of the small diameter portion 41c from the axial end face of the crank web 41a through the crank web 41a and the large diameter portion 41b. The small diameter portion 41c of the pump crankshaft 41
The drive gear 48 meshes with the pump driving gear 23 of the balancer 20, a one-way clutch 49 meshes with the reduction gear 16, and a worm 50 for driving the fuel pump 33.
And are attached. The drive gear 48 is disposed at a position adjacent to the large diameter portion 41b, the worm 50 is disposed on the shaft end side of the small diameter portion 41c, and the one-way clutch 49 is disposed between the drive gear 48 and the worm 50. The worm 50 is keyed to the small diameter portion 41c.

The drive gear 48 is rotatably supported by the small-diameter portion 41c, and engages with an inner peripheral side of the boss portion 48a in which the pin 47 of the sliding rod 46 is fitted as shown in FIG. A groove 48b is formed. This engagement groove 48b is
In this embodiment, the pin 47 is formed at four locations so that the pin 47 can be easily fitted. That is, the sliding rod 46 is connected to the crank web 41a.
When the pin 47 is retracted from the side to the small-diameter portion 41c side and the pin 47 is fitted into the engagement groove 48b, the rotation of the drive gear 48 rotating together with the balancer 20 is transmitted to the pump crankshaft 41 via the pin 47 and the sliding rod 46. Can be In this embodiment, the drive gear 48 is formed to have a slightly smaller diameter than the pump drive gear 23, and thus the number of revolutions is slightly higher than that of the crankshaft 9. For this reason, the drive gear 48 is
When coupled to 41, pump crankshaft 41 will rotate slightly faster than crankshaft 9. Further, when the sliding rod 46 advances toward the crank web 41a, the pin 47 is disengaged from the engagement groove 48b, and power is not transmitted from the drive gear 48.

The one-way clutch 49 is configured to transmit only rotation of the outer peripheral member to the inner peripheral member. The outer peripheral member is meshed with the reduction gear 16, and the inner peripheral member is connected to the small diameter portion 41c. That is, in this one-way clutch 49,
Only the power from the reduction gear 16 is transmitted to the pump crankshaft 41. The outer peripheral member of the one-way clutch 49 is formed to have a slightly larger diameter than the small diameter gear 9a of the crankshaft 9 so as to rotate at a lower speed than the crankshaft 9. That is, when the sliding rod 46 is retracted and the drive gear 48 and the pump crankshaft 41 are connected,
Since the drive gear 48 rotates at a higher speed than the outer peripheral member of the one-way clutch 49, the one-way clutch 49 is disengaged and power is not transmitted from the reduction gear 16. At this time, the power is transmitted from the drive gear 48 to the pump crankshaft 41 and the pump crankshaft 41 rotates at a high speed. Then, when the sliding rod 46 moves forward and the power of the engine is not transmitted to the drive gear 48, the rotation of the reduction gear 16 is transmitted to the pump crankshaft 41 via the one-way clutch 49.

Reference numeral 51 denotes a power switching piston for moving the drive rod 46 forward and backward. The piston 51 is reciprocally fitted into a cylinder 35a integrally formed with the crankcase cover 35, It is in contact with the shaft end via a ball 52. Reference numeral 53 denotes a return spring for urging the sliding rod 46 in the backward direction. Further, a cylinder cover 54 for closing the opening of the cylinder is screwed to the cylinder portion 35a. The cylinder communicates with an air supply portion of the combustion chamber fuel injection device 7 via an air pipe 55 connected to the cylinder cover 54. Reference numeral 56 denotes a pressure accumulator interposed in the air pipe 55. The pressure accumulator 56 regulates the air pressure injected from the combustion chamber fuel injection device 7 and the air pressure supplied to the cylinder. That is, when the engine speed is low, such as at the time of starting, the discharge pressure of the air pump 31 is small, and air pressure is not applied to the cylinder for driving the sliding rod. Held in position. Further, when the engine runs in the normal running state and the engine speed reaches the high rotation range and the air pressure from the air pump 31 becomes larger than the set value of the accumulator 56, the air is accumulated from the accumulator 56 to the sliding rod driving cylinder. Supplied. Then, the piston 51 is pushed by the air pressure, and the sliding rod 46 moves forward.

The fuel pump 33 is a rotary pump including an eccentric piston 58 rotating in a cylinder 57 and a plurality of centrifugal rollers 59 rotating with the eccentric piston 58. It is fixed to the crankcase cover 35 while being clamped. A drive shaft 62 for driving the eccentric piston 58 is substantially perpendicular to the crankshaft 9 by being directed substantially vertically, and is connected to the pump crank through a connecting shaft 63 supported by the crankcase 2. It is connected to the shaft 41. This connecting shaft 63
The worm gear 63a is disposed on the same axis as the drive shaft 62, and a worm gear 63a provided at a lower end thereof meshes with the worm 50 of the pump crankshaft 41. Therefore, the rotation of the pump crankshaft 41 is transmitted to the connection shaft 63 via the worm 50 and the worm gear 63a, and the rotation of the connection shaft 63 causes the drive shaft 62 to rotate. That is,
The pump crankshaft 41 includes an air pump 31 and a fuel pump 33.
When the rotation speed of the pump crankshaft 41 changes, the rotation speed of the fuel pump 33 together with the air pump 31 changes. The connecting shaft 63 is connected to the drive shaft 62 in such a manner that the connecting shaft 63 is supported by the crankcase 2 and then connected to the drive shaft 62.
So that the lower end of the drive shaft 62 is fitted into a fitting groove formed at the upper end of the connection shaft 63 so as to be able to be connected. That is, in order to incorporate the fuel pump 33 into the engine 1, first, the crankcase cover 35 is attached with the connecting shaft 63 supported by the crankcase 2. Then, while connecting the drive shaft 62 to the connection shaft 63, the pump body including the cylinder 57, the housings 60, 61 and the like is placed on the crankcase cover 35. In this state, the lower housing 61 is fixed to the crankcase cover 35 with bolts or the like, and the assembly is completed. Reference numeral 64 denotes an accumulator for keeping the pressure of the fuel discharged from the fuel pump 33 at a predetermined value, and is connected to the fuel outlet of the upper housing 60.

The accessory drive device for an air / fuel injection engine according to the present invention includes a pump crankshaft 41, a sliding rod 46, a drive gear 48, a one-way clutch 49, and the like. In this drive device, as a drive path for driving the air pump 31 and the fuel pump 33, a path with a relatively small reduction ratio in which power is transmitted from the crankshaft 9 via the balancer 20 and the drive gear 48, and a drive path from the crankshaft 9 Two paths having different reduction ratios from a path having a relatively large reduction ratio in which power is transmitted via the reduction gear 16 and the one-way clutch 49 are provided. The two driving paths are switched by the sliding rod 46 according to the engine speed. That is, when the engine speed is in a low rotation range at the time of starting or the like, the pump crankshaft 41 is connected to the drive gear 48 and rotates at high speed because the sliding rod 46 is held at the retracted position. In addition, when the engine speed is in a high rotation range such as during normal running, the pump crankshaft 41 rotates at a low speed due to the transmission of power from the one-way clutch 49 due to the forward movement of the sliding rod 46.

Therefore, the air pump 31 and the fuel pump 33 rotate at a high speed when the engine speed is in a low speed range, and rotate at a low speed when the engine speed is in a high speed range. Even if the number of rotations is low, the air pump 31 and the fuel pump 33 can rotate at high speed to quickly increase the air pressure and the fuel pressure to predetermined pressures.

Further, as shown in this embodiment, when the air pump 31 and the fuel pump 33 are installed on the upper side of the crankcase 2 and on one side in the left-right direction, the engine width can be prevented from being increased by both pumps. In addition, it is possible to prevent both pumps from interfering with an obstacle. Further, in the above-described structure, the air pump 31, the air hose 32 connecting the fuel pump 33 and the combustion chamber fuel injection device 7, and the fuel hose 34 follow the same path and pass upward from the rear of the cylinder. Since they come close to each other, the handling of these hoses becomes easy.

〔The invention's effect〕

As described above, the auxiliary device driving device for an air-fuel injection engine according to the present invention includes an air pump and a fuel pump for injecting air and fuel into a combustion chamber of the engine, respectively. And the other of the two drive paths having the larger reduction ratio is connected to the drive main shaft connected to the air pump and the fuel pump via a one-way clutch, and the speed is reduced. The smaller ratio is connected to the main drive shaft through power switching means for transmitting power when the engine speed is in a low speed range and shutting off power when the engine speed reaches a high speed range. The pump rotates at a high speed when the engine speed is in a low speed range, and rotates at a low speed when the engine speed is in a high speed range. Therefore, even when the rotation speed of the crankshaft is low as in the case of starting with a kick lever, the air pump and the fuel pump can rotate at high speed to quickly increase the air pressure and the fuel pressure to predetermined pressures. Therefore, according to the present invention, air / air
A fuel injection engine can be obtained.

[Brief description of the drawings]

1 is a side view of an air / fuel injection engine according to the present invention, FIG. 2 is a sectional view taken along line II-II in FIG. 1, FIG. 3 is a sectional view taken along line III-III in FIG. FIG. 5 is a longitudinal sectional view of the fuel pump, and FIG. 5 is an exploded perspective view of a pin clutch constituting power switching means. 1 ... air / fuel injection engine, 2 ... crankcase, 6 ... combustion chamber, 7 ... combustion chamber fuel injection device, 9 ...
Crankshaft, 9a …… Small diameter gear, 9b …… Large diameter gear, 16 ……
Reduction gear, 22 Balancer gear, 23 Pump drive gear, 31 Air pump, 33 Fuel pump, 41 Pump crankshaft, 46 Slide rod, 48 Drive gear, 49
…… One-way clutch, 62 …… Drive shaft, 63 …… Connection shaft.

Claims (1)

(57) [Claims] An air pump and a fuel pump for respectively injecting air and fuel into a combustion chamber of an engine are connected to a crankshaft of the engine through two drive paths having different reduction ratios. The one with the larger reduction ratio is connected to the drive main shaft connected to the air pump and the fuel pump via a one-way clutch, and the one with the smaller reduction ratio is used when the engine speed is in the low rotation range. And a drive switching means for shutting off the power when the engine speed reaches a high rotation range. The auxiliary drive device for an air / fuel injection engine is connected to the drive main shaft.