JPH0367058A - Fuel supply device for car - Google Patents

Abstract

PURPOSE:To prevent vapor generation and production of a counterflow phenomenon by connecting the outlet from a jet pump with a fuel pipe inlet in plumb condition continuously through an arc of a circle. CONSTITUTION:The return fuel to be returned from the engine part is introduced to a fuel supply pipe 12 of a sub-tank 11 through a return pipe 13, led to the inlet 141 of a jet pump 14 in horizontal condition from this pipe 12 in plumb condition, and converted into a horizontal flow to then reach a nozzle 142. The fuel is jetted out of a nozzle 142 at a hgh speed, and thereby the fuel in a fuel tank is inhaled from a fuel lead-in hole 15 to be introduced to a throat 143 and released into the sub-tank 11 from over the liquid surface therein through a fuel pipe 16. Because the outlet 144 of the pump 14 is led to the plumb pipe 16 through a coupling part 17 in the form of an arc of a circle, which provides good releasing-through of the vapor generated in high temp. condition, and drop of the pump 14 performanced in the high temp. condition is suppressed certainly.

Description

[Detailed description of the invention] [Industrial application field] [Prior art] A fuel pump is installed in a fuel tank mounted on a vehicle,
A fuel supply device is known in which fuel is supplied to an engine using this fuel pump. However, in such a fuel supply device, if the fuel level in the fuel tank decreases or the fuel level oscillates or tilts, and there is a shortage of fuel at the intake port of the fuel pump, the air Even the fuel is sucked into the fuel pump, preventing smooth fuel supply to the engine.

In order to solve these problems, a sub-tank is installed at the bottom of the fuel tank, a fuel intake is formed at the bottom of the sub-tank, and the fuel taken in from this fuel intake is transferred to the vertical fuel tank. It has been considered to lead the fuel to a predetermined level in the sub-tank using a pipe, stabilize the liquid level in the sub-tank, and ensure that fuel is always smoothly supplied to the engine.

In this case, the fuel intake port is formed as an opening in the bottom of the sub-tank that communicates with the inside of the fuel tank.A jet pump is formed adjacent to this intake port, and the high-speed flow of fuel flowing into this jet pump It sucks in the fuel in the fuel tank and sends this fuel into a fuel vibrator that stands up at a right angle.

In this case, the jet pump is formed horizontally at the bottom of the sub-tank, and the fuel pipe stands vertically, so that the outlet of the jet pump and the inlet of the fuel pipe are connected by a right angle. Therefore, at the inlet of this fuel pipe, the fuel flowing at high speed through the throat of the jet pump does not smoothly bend at a right angle and transfer to the fuel pipe, but especially when the temperature is high, the fuel flows at a right angle. Vapor was generated in some areas, and backflow began to occur.

[Problem to be solved by the invention, 8] This invention was made in view of the above points, and as a result pressure loss occurs at the outlet of the jet pump, vapor is generated, and backflow occurs. We have solved the problem that caused this phenomenon, and now the fuel is stably sucked from the fuel tank into the sub-tank, and the fuel is stably taken into the sub-tank to ensure a stable fuel supply to the engine. For example, the present invention aims to provide a fuel supply device for an engine mounted on a vehicle.

[Means for Solving the Problems] In the fuel supply device according to the present invention, a sub-tank in which a fuel pump is installed is provided in the fuel tank, a jet pump is formed on the bottom of the sub-tank, and a jet pump is formed on the bottom of the sub-tank. The fuel in the fuel tank is sucked in from the inside of the fuel tank.

Then, this sucked fuel is guided from the jet pump outlet installed horizontally to the fuel pipe set vertically, and is supplied into the subtank from above the liquid level of the subtank. The jet pump outlet and the vertical fuel vibe inlet are connected by an arc.

[Function] In the fuel supply device configured in this way, the flow of fuel supplied to the return vibe is supplied to the jet pump in a horizontal state along the bottom of the sub-tank, and the flow of fuel is The fuel in the fuel tank is sucked in from the bottom of the sub-tank.

Then, the horizontal flow of fuel along the bottom of the sub-tank is guided to a vertically set fuel pipe, guided above the liquid level of the sub-tank, and supplied into the sub-tank. In this case, the jet pump outlet with a horizontal fuel flow is led via an arcuate section into a vertical fuel pipe. Therefore, the flow of fuel from the jet pump outlet to the fuel pump is extremely smooth, and it is possible to effectively suppress the occurrence of failures such as backflow caused by vapor generation in the fuel, and as a result, for example, Fuel supply control can be stably performed for the engine installed in a vehicle.

[Embodiments of the invention] Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

Figure 1 shows the cross-sectional structure of the sub-tank 11.
is installed in a fuel tank mounted on a vehicle such as an automobile. A fuel supply vibe 12 is set in the sub tank 11 in a vertical state, and a return vibe 13 is connected to this fuel supply vibe 12. Return fuel from an engine (not shown) is connected to this return pipe 13. Supplied.

A jet pump 14 is set at the bottom of the sub-tank 11. This jet pump 14 has an inlet 141 that is set to continue perpendicularly to the lower end of the fuel supply vibrator 12, and includes a nozzle 142 formed along the bottom surface of the sub-tank 11. Therefore, the fuel supplied to the return pipe 13 is ejected from the nozzle 142 at high speed.

Here, a fuel inlet 15 opening toward the outside is formed in the bottom plate of the sub-tank 11 corresponding to the outlet portion of the nozzle 142, and the high-speed fuel flow generated at the outlet of the nozzle 142 causes The fuel in the fuel tank outside the sub-tank 11 is sucked in. In this case, by setting the sub-tank 11 close to the bottom portion of the fuel tank, even if the amount of fuel in the fuel tank decreases, the jet pump 14 reliably sucks the fuel.

The fuel sucked from the fuel inlet 15 is transferred to the sub tank 11.
It is guided to the throw 143 set to extend horizontally on the lower surface of the jet pump 14, and is guided to the outlet 144 of the jet pump 14.

The outlet 144 of the jet pump 14 is connected to a fuel pipe te vertically set in the sub-tank 11, in which a backflow prevention function is set. In this case, the jet pump 14 is set horizontally along the bottom surface of the sub-tank 11, while the fuel pipe 16 is set vertically, and the fuel flowing through the jet pump 14 is bent at a right angle and directed upward. will be sent. The outlet 144 of the jet pipe 14 facing in the horizontal direction and the inlet of the vertical fuel vibrator 16 are connected by an arcuate joint 17.

A fuel pump 18 is housed inside the sub-tank 11 . This fuel pump 18 discharges fuel introduced into the sub-tank 11 to the outside via a discharge pipe 19, and this discharged fuel is supplied to an engine (not shown).

The return fuel that comes back from the engine part is
The fuel is introduced into the fuel supply pipe 12 of the sub-tank 11 via the return pipe 13. Then, this return fuel is guided from the vertical fuel supply pipe I2 to the inlet 141 of the horizontal jet pump 14, converted into a horizontal flow, and reaches the nozzle 142. Fuel is ejected from the nozzle 142 at high speed, and the fuel in the fuel tank is sucked through the fuel inlet 15 by this high-speed fuel flow and introduced into the throat 143. Then, this fuel is discharged from above the liquid level of the sub-tank 11 into the sub-tank (1) via the fuel pipe 1G.

Here, the outlet 144 of the jet pump I4 is led to the vertical fuel vibrator 16 via the arc-shaped coupling part 17.

For this reason, vapor generated in a high temperature state can be easily removed, and deterioration in the performance of the jet pump 14 in a high temperature state is reliably suppressed.

By configuring the joint 17 in an arc shape in this way, the temperature at which the liquid level in the sub-tank 11 starts to drop due to vapor lock generated at high temperatures is lower than that in the case where the joint 17 is bent at right angles. For example, as shown in Fig. 2, it rose.

In the example shown in FIG. 2, an example in which the radius R of the arc of the connecting portion 17 is "4.5" is shown by a solid line, and a case where this arc does not exist is shown by a broken line.

[Effects of the Invention] As described above, according to the fuel supply device according to the present invention, a sub-tank housing a fuel pump is installed in the fuel tank, and the jet pump installed in the sub-tank sucks the fuel in the fuel tank. The fuel pump supplied into the sub-tank is designed to supply the engine to the engine.In the sub-tank, the fuel sucked in by the jet pump smoothly flows into the vertical fuel pipe. It is then released from above the liquid level into the sub-tank. In particular, the fuel passage from the jet pump, which is set horizontally, to the vertical fuel pipe is formed by an arc-shaped joint, which reliably suppresses the occurrence of vapor lock even in high-temperature conditions, ensuring a smooth flow. This ensures accurate fuel supply control.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional configuration diagram for explaining a fuel supply device according to an embodiment of the present invention, and FIG. 2 is a diagram showing the vapor flow at the jet pump outlet of the above-mentioned fuel supply device and a conventional fuel supply device of this type. FIG. 3 is a diagram comparing and showing the temperatures at which failures occur due to the occurrence of the failures. 11...Subtank, 12...Fuel supply pipe, turn pipe, 14...Jets] pump, 1410.
142... Nozzle, 143... Throat, 1441
5... Fuel inlet, te... Fuel pipe (vertical) viscous part (arc shape). 13...Enter...Exit 1. 17...

Claims (1)

[Scope of Claims] A sub-tank equipped with a fuel pump and installed inside the fuel tank; A jet pump set at the bottom of the sub-tank and configured to suck fuel from outside the sub-tank; and an outlet of the jet pump. leading the fuel continuously and sent by a jet pump to above the liquid level of the sub-tank;
1. A fuel supply device for a vehicle, comprising: a fuel pipe set in a vertical direction, wherein a connection portion between the jet pump outlet portion and the vertical fuel pipe is continuous in an arc.