JPH09226389A - Fuel supply device for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the initial fuel filling quantity in a production factory by providing an ejector pump having an intake port opened in the vicinity of the bottom of a main tank and a discharge port opened above the lowest liquid surface level in a fuel supply device having a main tank and a sub-tank for accepting a fuel pump. SOLUTION: At the time of injecting initial fuel in a production line, when fuel is injected from an oil supply pipe 4, the fuel flows into a sub-tank 3 through an introduction port 13, and at this time, injection is stopped just before the liquid level F1 reaches the introduction port 13 to overflow into a main tank 1. When an engine is started in such a condition, fuel in the sub-tank 3 is sucked to be supplied to the engine through a delivery passage 9. Surplus fuel in a fuel pump 2 is returned through a return path 10, and by the venturi action of flow of surplus fuel passing a venturi part 16 of an ejector pump 12, fuel in the main tank 1 is sucked through a communicating path 11 to be exhausted to the sub-tank 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle fuel supply system for supplying fuel in a fuel tank mounted on a vehicle to an internal combustion engine by means of a fuel pump provided in the tank, and particularly, at the time of factory shipment. The present invention provides an effective technique for reducing the amount of fuel injected into a tank.

[0002]

2. Description of the Related Art The liquid level in a fuel tank of an automobile accelerates,
Since the liquid fuel moves forward, backward, leftward and rightward due to the inertial force acting during deceleration and turning, the liquid fuel is constantly changing. In this way, even if the fuel flows in the tank, in order to keep the liquid level around the suction port of the pump higher than others, the fuel that has once flowed into the main tank flows out. It is common to have sub-tanks designed to be difficult.

As an example of such a sub-tank, Japanese Utility Model Publication No. 5-11337 discloses that a pump is disposed in a sub-tank suspended from a lid that seals an upper opening of a main tank and is connected to a discharge port of the pump. There is disclosed a structure in which the supply pipe is extended to the outside of the main tank and a return pipe for circulating the surplus fuel supplied to the engine is exposed to the inside of the sub tank. In this case, in order to further take in the fuel in the main tank into the sub tank, an ejector pump having a suction port opened at the bottom of the main tank is provided at the end of the return pipe. According to this, the fuel in the main tank is sucked into the sub tank due to the flow of the return fuel, so that the liquid level in the sub tank always rises with respect to the liquid level in the main tank during engine operation.

[0004]

On the other hand, in a vehicle production plant, it is necessary to inject fuel into a tank for a final test on a bench and for self-propelled vehicle up to a vehicle yard outside the plant. From the economical aspect, there is a demand to reduce the initial injection amount as much as possible.

However, in the case of the conventional tank structure disclosed in the above publication, the liquid level of the sub tank constantly rises above the liquid level of the main tank during operation of the engine, and the fuel once taken into the sub tank is transferred to the main tank by the check valve. However, at the time of initial fuel injection, the liquid levels of the sub tank and the main tank become equal to each other. Therefore, to secure the initial startability, it is necessary to inject fuel into the main tank as much as possible so that the suction port of the pump is submerged below the liquid level, and the initial fuel injection amount is reduced to less than that. It was difficult to do.

The present invention has been devised to eliminate such inconveniences, and its main purpose is to increase the initial fuel injection amount in a vehicle production plant and increase the manufacturing cost. Another object of the present invention is to provide a vehicular fuel supply device that can be further reduced.

[0007]

In order to achieve such an object, in the present invention, a structure of a sub-tank provided in a main tank for receiving a fuel pump is provided with a pipe for returning surplus fuel from an engine. In order to discharge the fuel sucked from outside the pipe into the sub tank by the fuel flowing in the pipe,
An ejector pump with an inlet opening near the bottom of the main tank and an outlet opening above the minimum liquid level required for initial engine start, and the minimum liquid level to introduce fuel from the oil supply pipe And a fuel introducing port provided above the fuel introducing port, and a portion below the fuel introducing port is substantially closed.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The configuration of the present invention will be described below in detail with reference to the accompanying drawings.

FIG. 1 shows a fuel tank T to which the present invention is applied.
The whole is shown. The fuel tank T is a main tank 1 that substantially functions as a fuel storage tank, and a main tank 1 that shuts down the fluctuation of the liquid level due to the motion of the vehicle so that the suction port of the fuel pump 2 is always submerged below the liquid level. It comprises a sub tank 3 provided in the tank 1. The main tank 1 is connected to an oil supply pipe 4 which is opened at a proper position on the vehicle body.
There is an opening near the upper part of the peripheral wall.

The sub-tank 3 is basically composed of a container body 5 having a bottomed cylindrical shape, and a lid plate 6 which is fitted in an opening of the container body 5 in a liquid-tight manner. It is inserted into the main tank 1 through the opening 7 provided in the. The lid plate 6 is liquid-tightly joined to the peripheral portion of the opening 7 of the main tank 1 via the gasket 8.

A fuel pump 2 is housed inside the container body 5. A discharge passage 9 connected to the discharge port of the fuel pump 2 and a return passage 10 for circulating the excess fuel from the engine are integrally fixed to the cover plate 6. In addition, on the peripheral wall of the container body 5, a communication passage 1 for communicating an upper space in the sub tank 3 with a bottom space in the main tank 1 is provided.
1 is formed.

A known ejector pump 12 for sucking the fuel outside the pipeline by the fuel flowing in the pipeline is provided between the sub-tank openings of the return passage 10 and the communication passage 11.

An inlet port 13 for introducing the fuel from the oil supply pipe 4 is provided in the upper part of the peripheral wall of the container body 5. At the lower edge of the introduction port 13, a receiving plate 14 for receiving the fuel discharged from the discharge port of the oil supply pipe 4 facing the introduction port 13 is provided.

Next, the operation of the device of the present invention will be described.
When fuel is injected into the main tank 1 from the fuel supply pipe 4 at the time of initial fuel injection at the time of line off from the production line,
First, the fuel directly flows into the sub tank 3 from the inlet 13 provided in the upper part of the peripheral wall of the container body 5 of the sub tank 3. After the liquid level FL in the sub-tank 3 reaches the inlet 13, it overflows into the main tank 1 and fills the main tank 1. Is set so as to be secured at the liquid level below the inlet 13, so it is sufficient to inject until just before overflow.

In this state, the intake port provided in the lower portion of the fuel pump 2 is already submerged below the liquid surface. Therefore, when the engine is started, the fuel in the sub-tank 3 is drawn from the intake port through the filter 15. Then, the fuel is fed from the discharge port provided on the upper portion of the fuel pump 2 to the engine (not shown) through the discharge passage 9.

The capacity of the fuel pump is set so that a discharge amount sufficient for full load operation can always be generated, and excess fuel during low load operation or partial load operation is
It recirculates to the sub tank 3 through the return passage 10. At this time, since the venturi portion 16 is decompressed by the flow of the surplus fuel passing through the venturi portion 16 of the ejector pump 12 provided at the discharge port of the return passage 10, the fuel in the main tank 1 is sucked through the communication passage 11. Then, it is discharged from the discharge port of the ejector pump 12 into the sub tank 3 together with the surplus fuel. As a result, during operation of the engine, the excess fuel is constantly circulated and the fuel in the main tank 1 is sucked in at the same time, so that the liquid level of the sub tank 3 is always higher than the liquid level of the main tank 1, and when turning, etc. Filter 1 installed at the inlet of the fuel pump 2 even if the fuel moves to the
5 is not exposed on the liquid surface. Since the bottom of the container body 5 of the sub tank 3 is closed, the fuel once taken into the sub tank 3 does not flow out of the sub tank 3 other than being sucked by the fuel pump 2.

[0017]

As described above, according to the present invention, when fuel is injected into the tank, the fuel first flows into the sub-tank, and the minimum amount of fuel required for initial starting is stored exclusively in the sub-tank. Since the bottom of the sub tank is closed, the fuel once taken into the sub tank does not flow out unless it overflows. Moreover, this action can be obtained without providing the check valve by providing the intake port of the ejector pump at the bottom portion of the sub-tank and the discharge port at the upper portion of the sub-tank, so that the manufacturing cost is not increased.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram of a fuel tank to which the present invention is applied.

[Explanation of symbols]

 1 Main Tank 2 Fuel Pump 3 Sub Tank 4 Oil Supply Pipe 5 Container 6 Cover Plate 7 Opening 8 Gasket 9 Discharge Passage 10 Return Passage 11 Communication Passage 12 Ejector Pump 13 Inlet 14 Filter Plate 15 Filter 16 Venturi Part

Claims (1)

[Claims] 1. A fuel supply system for a vehicle, comprising: a main tank; and a sub-tank for receiving a fuel pump in the main tank, wherein the sub-tank flows in a pipeline for returning surplus fuel from an engine. In order to discharge the fuel sucked from the outside of the pipeline by the fuel into the sub-tank, an inlet is opened near the bottom of the main tank, and an outlet is opened above the minimum liquid level necessary for initial starting of the engine. Having an ejector pump and a fuel introduction port provided above the lowest liquid level in order to introduce the fuel from the oil supply pipe, and the portion below the fuel introduction port is substantially closed A fuel supply device for a vehicle, wherein: