JP2615074B2 - Vehicle fluid pump device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a fluid pump device for a vehicle such as a fuel pump that operates by pulsating pressure of an engine such as a motorcycle.

(Prior art and its problems) Conventionally, as an arrangement structure of a fuel pump of a motorcycle, for example, a structure described in JP-A-62-83282 is known. According to this, fuel is supplied by a fuel pump to an engine cylinder constituting a power unit supported swingably on a frame, and the fuel pump is connected to a fuel tank located below a footrest and the cylinder. And below the cylinder.

However, according to the arrangement structure of the fuel pump, the fuel pump takes in the pulsating pressure from, for example, the pulsating pressure outlet of the engine into the suction chamber that expands and contracts due to, for example, the diaphragm motion of the diaphragm, and accordingly, the fuel tank according to the pulsating pressure When the fuel in the pump chamber connected to the engine is fed toward the cylinder, the position of the fuel pump is lower than that of the engine. There is a problem that unnecessary substances are likely to stay, which may reduce the pumping action of the fuel pump particularly when the engine is restarted. In particular, when the pulsating pressure outlet of the engine is formed at an arbitrary position in the crank chamber, the oil in the crank chamber penetrates into the suction chamber through the pressure guide pipe to the diaphragm constituting the suction chamber. By sticking, not only preventing smooth membrane movement of the diaphragm thereafter, but also necessitating replacement of the expensive diaphragm.

SUMMARY OF THE INVENTION An object of the present invention is to solve such a problem of the prior art, and the pulsation pressure from a pulsation pressure outlet provided in a crankcase of a two-stroke engine is taken into a suction chamber to thereby generate the pulsation. A fluid pump device for a vehicle that supplies a fluid in a pump chamber in a predetermined direction according to a pressure, the fluid pump for a vehicle being capable of preventing impurities such as oil entering the suction chamber of the fluid pump device from remaining in the suction chamber. It is to provide a device.

(Means for Solving the Problem) The object described above is to take a pulsating pressure from a pulsating pressure outlet provided in a crankcase of a two-stroke engine into a suction chamber, so that a fluid in a pump chamber is changed in accordance with the pulsating pressure. In a fluid pump device for a vehicle that feeds the fluid in a predetermined direction, the fluid pump device is fixed to a vehicle body frame, and a crankcase of the two-stroke engine is moved from the vehicle body frame in a front-rear direction and rearward of the vehicle body frame. The body frame is swingably supported in the vertical direction via an extended link, and the suction chamber is disposed above and forward with respect to the pulsating pressure outlet, and the pulsating pressure outlet is A pressure guide pipe connecting the suction chamber and the pulsating pressure outlet port is inclined so as to be gradually lowered toward the pulsation pressure outlet port side; Achieved by a body pump device.

(Action) According to the fluid pump device for a vehicle of the present invention, when impurities such as oil enter the suction chamber of the fluid pump together with the pulsating pressure in the crankcase, the engine stops and the pump action of the fluid pump device is reduced. When stopped, impurities such as oil that have entered the suction chamber can be returned into the crankcase through the pressure guide pipe that is inclined so as to gradually decrease toward the pulsating pressure outlet port side, and oil and the like can be returned to the crankcase. By preventing impurities from remaining in the suction chamber of the fluid pump device and adhering to the diaphragm constituting the suction chamber, smooth diaphragm movement of the diaphragm is maintained, thereby eliminating the need for expensive diaphragm replacement. be able to. Accordingly, a smooth pumping operation can be performed without hindering the flow of the fluid when the fluid pump device is restarted. In addition, the fluid pump device is fixed to a vehicle body frame, and the crankcase of the two-stroke engine is connected to the vehicle body via a link extending from the vehicle body frame in the front-rear direction and rearward of the vehicle body frame. Since the frame is supported swingably in the vertical direction on the frame, it is easy to arrange the length of the pressure guide tube along the link. The arrangement of the fluid pump device in the vehicle can be made compact. further,
Since the amount of change in the inclination of the pressure guide tube can be reduced when the crankcase, that is, the pulsating pressure outlet is vertically swung, the bending of the pressure guide tube can be reduced and the pressure guide tube can be prevented from being damaged. , The return of impurities such as oil that has entered the suction chamber to the crankcase can be kept constant.

(Embodiment) As shown in FIG. 1, a bracket 1A and a link piece 2 are provided behind a body frame 1 of a scooter type motorcycle.
(E.g., a two-cycle engine) 3 is swingably suspended via a fin, and a fuel tank 5 is disposed below the footrest 4. Further, one end of a substantially straight pressure guide tube 6 is attached to a predetermined portion (pulsation pressure outlet) of the crankcase 3a of the engine 3, and the other end of the pressure guide tube 6 is located in front of the vehicle body. The other end of the pressure guide tube 6 is connected to a negative pressure intake port (to be described later) of the fuel pump 7 and has a height difference indicated by reference numeral h in the figure. doing. Here, a fuel inlet 7a of the fuel pump 7 is connected to the fuel tank 5, and a fuel outlet 7b located on the opposite side of the fuel inlet 7a.
Is connected to one end of a fuel transport pipe 8 and the other end is connected to a carburetor 9.

2 and 3 show details of the pulsating pressure outlet described above. A crankshaft 11 disposed in a crank chamber 10 of a two-cycle engine 3 has a pair of bearings 12 at a substantially central portion thereof. 13 and supported by
Sealing members are located outside the bearings 12 and 13 respectively.
14, 15 are installed. And, between one bearing 12 of the crankshaft 11 and the seal member 14,
A worm 16 is formed. The worm 16 has an axial direction perpendicular to the axial direction of the crankshaft 11 and has a worm gear of a drive shaft 18 which constitutes an oil pump 17.
19 are meshed. The drive shaft 18 is connected to the crank chamber 10
A pulsating pressure outlet 23 faces a space 22 formed between the worm gear 19 and the seal portion 21 in the housing 20 which communicates with the pulsating pressure. Joint pipe 24 from outlet 23
The pressure guide pipe 6 is connected to the joint pipe 24.

Further, as shown in FIG. 6, the pulsating pressure M is composed of a positive pressure and a negative pressure, so that not only a negative pressure but also a positive pressure having a maximum pressure value larger than the negative pressure is used, and a diaphragm described later is used. 24 membrane movements are planned.

FIGS. 4 and 5 show details of the fuel pump 7, in which a main body 7A is sandwiched and fixed by a base 7B and a cover 7C in a sandwich manner, and a gap between the main body 7A and the base 7B is provided. , And diaphragms 24 and 25 are interposed between the main body 7A and the cover 7C, respectively. The main body 7A is provided with a suction valve body 26 and a discharge valve body 27, and the inside of the main body 7A is provided with an inflow chamber 28, a storage chamber 29, and a discharge chamber 30 through both the valve bodies 26 and 27. Is divided into three rooms. And the diaphragm is provided in the storage chamber 29 in the base part 7B.
The joint pipe 32 is connected to the negative pressure inlet 31 of the adjacent suction chamber 35 via 24, and the main body 7A faces the Jont pipe 33 facing the inflow chamber 28 and the discharge chamber 30. Are connected to each other. The relief valve 36
Is provided for adjusting the pressure difference between the discharge chamber 30 and the inflow chamber 28.

With this configuration, the crankcase of the engine 3
The pulsating pressure obtained from 10 is the pressure guide pipe 6 and the joint pipe
Guided to the negative pressure intake 31 via 32, the diaphragm 24 is moved in one direction to open the valve body 26, and the fuel flowing in through the joint pipe 33 is fed into the storage chamber 29. . Next, the valve body 26 is opened by the diaphragm movement in the other direction of the diaphragm 24, and the valve body 27 is opened to discharge the fuel stored in the storage chamber 29 to the discharge chamber 30, and the fuel is jointed. It is fed to the carburetor 9 via the pipe 34 and the fuel transport pipe 8.

On the other hand, when the engine stops and the pumping operation of the fuel pump 7 also stops, the negative pressure intake port of the fuel pump 7
Since the pulsating pressure outlet 31 of the engine 3 is located above the pulsating pressure outlet 23 (the position indicated by h in the figure), in this embodiment, the outlet 23 is provided in the crank chamber 10 surrounded by the bearing 12 and the seal member 14. Even if the oil intrudes into the negative pressure intake 31, the oil naturally falls to the engine side and does not stop.

In the above-described embodiment, the fuel pump 7 for feeding the liquid fuel from the fuel tank 5 by the pump action is used as an example of the fluid pump. However, the fluid may be a gas. Further, since it is necessary to prevent the fuel from stopping in the fuel pump 7, the height position of the engine 3 with respect to the fuel pump 7 becomes a problem, but the height position of the fuel pump 7 with respect to the carburetor 9 does not matter.

(Effects of the Invention) As described above, according to the present invention, the pulsation pressure from the pulsation outlet provided in the crankcase of the two-stroke engine is taken into the suction chamber, and the pump chamber inside the pump chamber is responsive to the pulsation pressure. In a fluid pump device for a vehicle that supplies a fluid in a predetermined direction, the suction chamber is disposed above and in front of the pulsating pressure outlet, and a pressure guide that connects the pulsating pressure outlet and the suction chamber. Since the pipe is inclined so as to gradually decrease toward the pulsation pressure outlet, the engine stops when impurities such as oil enter the suction chamber of the fluid pump together with the pulsation pressure in the crankcase. When the pumping action of the fluid pump device stops, the suction chamber is connected to the suction chamber via a pressure guide pipe that is inclined so as to gradually decrease toward the pulsation outlet. Impurities such as oil that have penetrated can be returned to the inside of the crankcase, and impurities such as oil stop at the suction chamber of the fluid pump device and are prevented from adhering to the diaphragm constituting the suction chamber. Thereafter, smooth membrane movement can be maintained, and replacement of expensive diaphragms can be eliminated. Accordingly, a smooth pumping operation can be performed without hindering the flow of the fluid when the fluid pump device is restarted. In addition, the fluid pump device is fixed to a vehicle body frame, and the crankcase of the two-stroke engine is connected to the vehicle body via a link extending from the vehicle body frame in the front-rear direction and rearward of the vehicle body frame. Since it is configured to be vertically swingably supported by the frame, it is easy to arrange the pressure guide tube along the link, and the arrangement of the fluid pump device in the vehicle can be made compact. . Further, since the amount of change in the inclination of the pressure guide tube can be reduced when the crankcase, that is, the pulsating pressure take-out port swings up and down, the bending of the pressure guide tube can be reduced to prevent the pressure guide tube from being damaged. By maintaining the inclination of the guide tube, the return of impurities such as oil that has entered the suction chamber to the crankcase can be maintained at a constant rate.

[Brief description of the drawings]

FIG. 1 is a side view of an essential part showing an embodiment in which the present invention is applied to a scooter type motorcycle, FIG. 2 and FIG.
FIG. 2 is a sectional view of a main part showing details of the vicinity of the negative pressure outlet shown in FIG. 1, FIG. 2 is a sectional view taken along the line II-II of FIG.
4 and 5 show details of the fuel pump shown in FIG. 1. FIG. 5 is a sectional view taken along the line V--V of FIG. 4, and FIG. FIG. 4 is a characteristic diagram to be described. 3 ... engine, 6 ... pressure guide tube, 7 ... fuel pump (fluid pump), 23 ... negative pressure outlet, 31 ...
Negative pressure intake, 35 ... Suction chamber.

 ────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-62-34876 (JP, A) JP-A-58-88455 (JP, A) JP-A-58-88454 (JP, A)

Claims (1)

(57) [Claims] A pulsating pressure from a pulsating pressure outlet provided in a crankcase of a two-stroke engine is taken into a suction chamber, whereby a fluid in a pump chamber is supplied in a predetermined direction according to the pulsating pressure. In the fluid pump device, the fluid pump is fixed to a vehicle body frame;
The crankcase of the cycle engine is vertically swingably supported by the body frame via a link extending from the body frame to the front and rear direction and the rear side of the body frame, and the suction chamber is provided with the suction chamber. The pulsating pressure outlet is disposed above and forward with respect to the pulsating pressure outlet, and the pressure guide tube connecting the pulsating pressure outlet and the suction chamber is inclined so as to gradually decrease toward the pulsating pressure outlet. A fluid pump device for a vehicle, comprising: