JPH0315816Y2 - - Google Patents

Description

[Detailed description of the invention] (Field of industrial application) This invention returns the return fuel, which contains almost no easily vaporized components, from the oversupply of fuel sent to the engine from the sub-tank to the sub-tank from the return pipe. In order to compensate for the insufficient supply of fuel to the engine by the fuel pump due to the return fuel returning to the sub-tank via the return pipe, priority is given to the fuel overflowing from the overflow port provided in the sub-tank. This relates to a device that allows fuel to be pumped back into the sub-tank, refilled from the upper layer of the sub-tank, mixed with return fuel from the lower layer through a stirring phenomenon that occurs naturally within the sub-tank, and then supplied to the engine by a fuel pump.

(Prior art) Fuel filled in a sub-tank is supplied to the engine by a fuel pump, excess fuel is returned to the sub-tank by a return pipe on the engine side, and the fuel in the fuel tank is pushed up into the sub-tank to drain the fuel into the sub-tank. It is a well-known technique that an auxiliary pump is used to circulate excess fuel in the sub-tank to an overflow port, but the return fuel that is returned to the sub-tank by the return pipe contains components that are easily vaporized by the heat near the engine. It is an ideal fuel because the amount of fuel it contains is small and the return fuel that is returned to the sub-tank via the return pipe is 80 to 90% of the amount supplied to the engine by the fuel pump, but the amount is insufficient to re-send it to the engine. Naturally, it is necessary to refuel the subtank. However, conventionally, fuel containing a relatively large amount of vaporized soot components in the fuel tank is refilled, and a device for preferentially replenishing the sub-tank with high-quality fuel equivalent to return fuel has not yet been developed.

(Problems to be solved by the invention) In view of the above, the invention uses an auxiliary pump to preferentially use high-quality fuel that contains few easily vaporized components and is equivalent to the overflow fuel flowing out from the overflow port of the sub-tank. This problem is solved by pushing up the fuel into the sub-tank and replenishing it, thereby minimizing the replenishment rate of fuel that contains a high proportion of easily vaporized components in the fuel tank.

(Means for Solving the Problems) The fuel pump device of the present invention aims to specifically solve the problems mentioned in the previous section. a fuel pump 6 that replenishes the engine with fuel, and a return pipe 8 that returns fuel supplied by the fuel pump 6 and oversupplied on the engine side to the sub-tank 3.
In a configuration including an overflow port 14 that returns excess fuel in the sub-tank 3 to the fuel tank 1, and a replenishment pipe 9 equipped with an auxiliary pump 13 that pushes up the fuel in the fuel tank 1 to replenish the sub-tank 3, the return The lower end of the pipe 8 is placed at a low position inside the sub-tank 3, and the intake port 100 of the supply pipe 9 is covered with a cover 16 having an inlet 17 at the bottom of the fuel tank 1. an overflow pipe 1 that communicates with the cover 16 and the overflow port 14 that flows out the
9 is provided, and a replenishment port 12 which opens into the sub-tank 3 of the replenishment pipe 9 is provided at a high position.

A preferred embodiment of the invention will now be described.

(Example) The attached drawings illustrate the present invention, in which 1 is a fuel tank, 3 is a sub-tank installed inside the fuel tank 1, and is suspended from the upper opening 4 of the fuel tank 1. , a sealing lid 5 is applied to the mouth portion 4. Inside the sub-tank 3, a discharge pipe 7 of a fuel pump 6 is fixedly attached to the airtight lid 5 in a hanging manner, and furthermore, an excess amount of fuel sent to the engine side by the fuel pump 6 for consumption by the engine is transferred to the sub-tank 3. A return pipe 8 is provided to return the

At the bottom of the sub-tank 3 is an inlet port 10 fitted with a filter 11 that is almost in contact with the bottom of the fuel tank 1.
A replenishment pipe 9 is provided, and an auxiliary pump 13 is provided in the replenishment pipe 9 to suck up fuel from the fuel tank 1.
A replenishment port 12 of the replenishment pipe 9 is opened in the upper part of the sub-tank 3. Further, an overflow port 14 is provided in the sub-tank 3 at a level almost parallel to the supply port 12.

The above is a conventional known structure.

The present invention differs from the above-mentioned known structure by placing the lower end of the return pipe 8 at a lower position in the sub-tank 3 as shown in the figure, and by covering the suction port 10 and filter 11 of the supply pipe 9 with a cover 16. An inlet 17 opening into the fuel tank 1 is provided in the lower part, and an overflow pipe 19 is further provided for passing overflow fuel from the overflow port 14 to the cover 16.

(Function) The present invention supplies the return fuel from the sub-tank 3 to the engine by the fuel pump 6 and returns the return fuel, which contains almost no easily vaporized components as described above, to the sub-tank 3 from the lower end of the return pipe 8, and then returns the fuel to the sub-tank 3 by the fuel pump 6. In addition to having the conventional function of re-feeding fuel to the engine, the overflow fuel flowing out from the overflow port 14 is guided to the cover 16 by the overflow pipe 19, and the fuel is given priority and sucked into the suction port 10 of the auxiliary pump 13, and the fuel is sucked into the supply pipe 9. The fuel is pushed up and returned to the sub-tank 3 from the replenishment port 12 located at a high position, and the fuel cost other than that corresponding to the fuel consumption of the engine is returned to the overflow port 14.
In addition to repeating the circulation from the fuel tank 1 to the cover 16 and back to the sub-tank 3, when the supply amount is still insufficient due to the fuel pump, the content of components that easily vaporize in the cover 16 from the fuel tank 1 via the inlet 17 is relatively low. A large amount of fuel is allowed to flow in and pushed up into the sub-tank 3 by the auxiliary pump 13 and supply pipe 9.

(Effect) The present invention has the above-mentioned effect, and the fuel pump 6 supplies the return fuel to the engine and returns it to the sub-tank 3 through the return pipe 8, which contains almost no easily vaporized components, to the engine. In order to further utilize the benefit of retransferring and preventing vapor lock troubles, high-quality fuel similar to overflow fuel is transferred from the overflow port 14 of the sub-tank 3 to the supply pipe 9 that includes an overflow pipe 19, a cover 16, and an auxiliary pump 13. is returned to the sub-tank 3 through the replenishment port 12 of the fuel tank 1, making up for the lack of supply to the engine by the fuel pump 6, and at the same time causing the remaining amount to overflow as described above, to remove easily vaporized components in the fuel tank 1. It is possible to reduce the replenishment rate of fuel with a relatively high content, and although some air bubbles may be drawn in when entering the overflow pipe 19 from the overflow 14, the auxiliary pump 13 has a lower content of components that easily vaporize than the fuel in the fuel tank 1. This has the effect that fuel containing less air bubbles, etc., which cause vapor lock, can be returned to the sub-tank 3 from the supply pipe 9 and further supplied to the engine by the fuel pump 6.

[Brief explanation of the drawing]

The accompanying drawings are mostly longitudinal sectional front views illustrating the present invention. 1...Fuel tank, 3...Sub tank, 4...
Mouth part, 5...Sealing lid, 6...Fuel pump, 7...
Discharge pipe, 8... Return pipe, 9... Supply pipe,
10...Intake port, 11...Filter, 12...
Supply port, 13...Auxiliary pump, 14...Overflow port, 16...Cover, 17...Inflow port, 1
9...Overflow pipe.

Claims (1)

[Scope of Claim for Utility Model Registration] A fuel pump 6 that replenishes fuel to the engine in a sub-tank 3 provided inside the fuel tank 1; The return pipe 8 returns the excess fuel in the sub tank 3 to the fuel tank 1.
In a configuration including a sub-overflow port 14 for returning fuel to the sub-tank 3, and a replenishment pipe 9 equipped with an auxiliary pump 13 that pushes up the fuel in the fuel tank 1 to replenish the sub-tank 3, the lower end of the return pipe 8 is connected to a lower part of the sub-tank 3 position and the intake port 10 of the supply pipe 9
is covered with a cover 16 having an inlet 17 at the bottom of the fuel tank 1, an overflow pipe 19 is provided that communicates the cover 16 with an overflow port 14 provided in the sub-tank 3 to drain the internal fuel, A fuel pump device characterized in that a replenishment port 12 that opens into a sub-tank 3 of a pipe 9 is provided at a high position.