JPH0315817Y2 - - Google Patents

Description

[Detailed description of the invention] (Field of industrial application) This invention uses an auxiliary pump to preferentially push overflow fuel with a low content of easily vaporized components from the overflow port of the sub-tank into the sub-tank, thereby preventing its vaporization. This invention relates to a device that supplies fuel in a sub-tank containing few easily vaporized components to an engine using a fuel pump together with return fuel containing almost no easily vaporized components.

(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 excess fuel in the sub-tank is drained from an overflow port. It is a well-known technology that generates a circulation in which the fuel in the fuel tank overflows and returns to the fuel tank, and then pushes the fuel in the fuel tank up to the sub-tank, but in normal driving of a car, the fuel is returned from the engine to the sub-tank by the return pipe. As much as 80 to 90% of the fuel is supplied to the engine by the fuel pump, and the low boiling point fuel that is easily vaporized by the heat of the engine is vaporized, and this is returned mixed with liquid fuel. However, within the sub-tank, the vaporized gas escapes upwards and a portion of it is separated into the fuel tank from the overflow port, and the fuel in the sub-tank has a low content of easily vaporized components. Naturally, the fuel that overflows into the fuel tank has a low content of components that easily vaporize. However, no method has been taken to select only this overflow fuel and push it up into the sub-tank through the supply pipe.

(Problems to be Solved by the Invention) In view of the above, the present invention allows the air bubbles mixed with the overflow fuel to escape and pushes as much of it as possible back into the sub-tank using the auxiliary pump in the supply pipe. It is an object of the present invention to obtain a structure that allows an auxiliary pump, a fuel pump, and an engine to draw in fuel that contains almost no bubbles or easily vaporized components that cause vapor lock in the pump and fuel pump.

(Means for solving the problem) The purpose of the present invention is to specifically solve the problem mentioned in the previous section.The sub-tank 3 is installed inside the fuel tank 1, and A fuel pump 6 that replenishes fuel to the engine, and a replenishment pipe 9 that includes an auxiliary pump 13 that pushes up the fuel in the fuel tank 1 to replenish it to the sub tank 3. Return pipe 8 that returns fuel to sub tank 3
and an overflow port 14 for returning excess fuel in the sub-tank 3 to the fuel tank 1, the suction port 10 of the supply pipe 9 is covered with a cover 16, and the cover 16 has a bubble escape port 18 and an overflow port 14 for returning excess fuel in the sub-tank 3 to the fuel tank 1. The present invention relates to a fuel pump device characterized in that an inlet 17 communicating with the lower layer of the fuel pump is provided, and an overflow pipe 19 communicating the overflow port 14 and the cover 16 is further provided.

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 the upper opening 2 of the fuel tank 1.
A sealing lid 5 is applied to the container. A discharge pipe 7 of a fuel pump 6 is provided inside the sub-tank 3 by penetrating and fixed to the airtight lid 5, and a return pipe is also provided to return to the sub-tank 3 an excess amount of fuel sent to the engine side by the fuel pump 6 for consumption by the engine. 8 will be provided.

A replenishment pipe 9 having a suction port 10 with a filter 11 attached thereto, which is in almost contact with the bottom of the fuel tank 1, is provided on the lower side of the sub-tank 3, an auxiliary pump 13 is provided in the replenishment pipe 9, and a replenishment port 12 of the replenishment pipe 9 is provided. 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 provides a supply pipe 9 in the above-mentioned known structure.
The suction port 10 and the filter 11 are covered with a cover 16, an inflow pipe 17 leading to the lower layer of the fuel tank 1 is provided in the lower part of the cover 16, a bubble escape port 18 is formed in the upper surface part, and the overflow port 14 and the filter 11 are covered with a cover 16. An overflow pipe 19 communicating with the cover 16 is installed.

(Function) The fuel overflowing from the overflow port 14 has a low content of easily vaporized components. However, when overflowing, the overflow pipe 19
Air bubbles may get caught up in the fuel, and if air bubbles are mixed in, the performance of the auxiliary pump 13 will deteriorate. However, if even a small amount of air bubbles is mixed into the fuel led to the cover 16 by the overflow pipe 19, the air bubbles will escape into the fuel tank 1 from the air bubble escape port 18 due to the difference in specific gravity, and the fuel will be given priority to the suction port 10 of the auxiliary pump 13. The content of easily vaporized components is pumped up by the auxiliary pump 13 in the supply pipe 9 and returned to the sub-tank 3 through the supply port 12, and the fuel corresponding to the fuel consumption of the engine is returned to the lower layer of the sub-tank 3 from the return pipe 8. The amount of fuel that is low is replenished and supplied to the engine by the fuel pump 6, and the rate at which the auxiliary pump 13 pushes up the fuel with a relatively high content of easily vaporized components from the fuel tank 1 into the sub-tank 3 is reduced as much as possible. .

(Effect) The present invention uses the excess fuel supplied to the engine side by the fuel pump 6 to be returned to the sub-tank 3 by the return pipe 8, and the overflow port 14.
overflow from the overflow pipe 1
9, or after entering the fuel, which may contain air bubbles, is led to the cover 16, and then the bubble escape port 18 allows the air bubbles to escape into the fuel tank 1 due to the difference in specific gravity, thereby reducing the content of easily vaporized components. The fuel is returned to the fuel and pushed up to the sub tank 3 by the auxiliary pump 13 and the supply pipe 9 to replenish the fuel consumption of the engine, and the surplus fuel from the replenishment is pumped to the overflow port, the overflow pipe 19, and the cover 1.
6. The fuel can be circulated to the sub-tank 3 through the supply pipe 9 equipped with the auxiliary pump 13, which has the effect of reducing the rate of replenishment of fuel in the fuel tank 1 to the sub-tank 3 by the auxiliary pump.

[Brief explanation of the drawing]

The accompanying drawings are mostly longitudinal side views illustrating the present invention. 1...Fuel tank, 2...Mouth, 3...Sub tank, 5...Sealing lid, 6...Fuel pump, 7...
Discharge port, 8... Return pipe, 9... Supply pipe,
1... Suction port, 11... Filter, 12... Supply port, 13... Auxiliary pump, 14... Overflow port, 16... Cover, 17... Inflow port, 18
...Bubble escape port, 19...Overflow pipe.

Claims (1)

[Scope of Claim for Utility Model Registration] A sub-tank 3 is installed inside the fuel tank 1, a fuel pump 6 supplies fuel in the sub-tank 3 to the engine, and a fuel pump 6 pushes up the fuel in the fuel tank 1 to supply the sub-tank 3. A replenishment pipe 9 equipped with an auxiliary pump 13 to supply fuel to the sub tank 3, and a fuel pump 6 to supply excess fuel from the engine side to the sub tank 3.
and an overflow port 1 that returns excess fuel in the sub-tank 3 to the fuel tank 1.
4, the intake port 10 of the supply pipe 9 is covered with a cover 16, and the cover 16 is provided with an air bubble escape port 18 and an inlet port 17 that communicates with the lower layer of the fuel tank, and the overflow port 14 and A fuel pump device characterized in that an overflow pipe 19 communicating with a cover 16 is provided.