JP2808720B2 - Vehicle fuel supply system - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a fuel supply device for a vehicle having a fuel pump mounted in a fuel tank.

2. Description of the Related Art Conventionally, there is a fuel supply device for a vehicle in which a fuel pump is accommodated in a sub-tank and mounted in the fuel tank (Japanese Patent Laid-Open Publication No. Sho 63/1988)
-502446).

This fuel supply device transfers fuel from a fuel tank to a sub-tank, and pressure-feeds the fuel stored in the sub-tank by a fuel pump. Most of the pumped fuel is returned to the sub-tank via a return pipe, and the consumed fuel is supplied from the fuel tank to the sub-tank by a jet pump provided at the bottom of the sub-tank.

The jet pump is attached to the bottom of the sub tank and ejects fuel returned from the return pipe.The jet opens outside of the sub tank and faces the nozzle, and is sucked from outside the sub tank together with the fuel ejected from the nozzle. And a throat portion for guiding the fuel into the sub-tank.

[Problems to be Solved by the Invention] As described above, in the fuel supply device having the mechanism for taking the fuel in the fuel tank into the sub-tank by the jet pump, it is required to pump up the fuel as far as possible. Therefore, it is necessary to bring the jet pump close to the bottom surface of the fuel tank so that the fuel can be sucked even at a low liquid level.

From this, when the jet pump is assembled to the bottom of the sub tank, the above-described conventional jet pump:
Since the cross-sectional shape of the throat portion is formed in a circular shape, if the fuel pump is mounted on the jet pump, the mounting position of the fuel pump is increased.

Therefore, in order to lower the mounting position of the fuel pump and reduce the ineffective remaining amount, it is necessary to arrange the fuel pump beside the jet pump. As a result, the conventional fuel supply device has a problem that the mounting method of the fuel pump is limited.

The present invention has been made based on the above circumstances, and an object of the present invention is to provide a vehicular fuel supply device having an improved mountability of a fuel pump.

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a fuel tank,
A fuel pump mounted in the fuel tank, a sub-tank containing the fuel pump in the fuel tank, a return pipe for guiding excess fuel of the fuel discharged from the fuel pump into the sub-tank, A nozzle that is assembled to the bottom and ejects the fuel returned from the return pipe, and opens to the outside of the sub tank opposite to the nozzle, and is sucked from outside the sub tank together with the fuel ejected from the nozzle. A jet pump comprising a throat portion for guiding fuel into the sub-tank, and the throat portion has a flat shape.

[Operation and Effect of the Invention] The vehicle fuel supply device of the present invention having the above-described configuration has a flat throat portion constituting the jet pump, and thus has a greater cross-section than a conventional throat portion having a circular cross-sectional shape. If the opening area of the throat is the same, the overall height of the throat can be reduced.

As a result, the fuel pump can be mounted above the jet pump without significantly increasing the mounting position of the fuel pump, so that the mountability of the fuel pump can be improved as compared with the related art.

Example Next, a vehicle fuel supply device of the present invention will be described based on an example shown in the drawings.

 FIG. 1 is a longitudinal sectional view of a vehicle fuel supply device.

In the vehicle fuel supply device of the present embodiment, a fuel pump 1 is housed in a sub tank 2 and mounted in a fuel tank 3.

The fuel tank 3 has an opening 3a for inserting the sub-tank 2 containing the fuel pump 1 in the upper wall surface (the upper surface in FIG. 1).
Is provided. The opening 3a is airtightly closed by a cover 5 via a packing 4.

When the fuel pump 1 is energized, the fuel pump 1 sucks the fuel at the bottom inside the sub-tank 2 through the filter 6, and transfers the sucked fuel through the discharge pipe 7 connected to the discharge port 1 a of the fuel pump 1. To the outside. The pumped fuel is supplied to a combustion chamber (not shown) of the engine via a fuel injection valve (not shown), and excess fuel is guided again into the sub-tank 2 through the return pipe 8.

The discharge pipe 7 and the return pipe 8 are each made of metal (material STSW), are insert-molded in the cover 5, and are formed integrally with the cover 5.

The sub-tank 2 includes a resin-made sub-tank body 9 having an open upper end and a resin-made sub-tank cover 10 for closing the opening of the sub-tank body 9 for housing the fuel pump 1, and is provided integrally with the cover 5. It is supported by a bracket 11 (described later).

The sub tank main body 9 has a substantially elliptical upper end opening,
With the fuel pump 1 housed, about 700 cc of fuel can be stored inside.

As shown in FIG. 2, the sub-tank body 9 and the sub-tank cover 10 have three claws 9a provided on the outer periphery of the upper end of the sub-tank body 9 and three places provided on the peripheral edge of the sub-tank cover 10. Is assembled by fitting the grooved arm 10a.

Discharge port 1a of fuel pump 1 housed in sub tank 2
And a discharge pipe 7 fixed to the cover 5 are connected by a bellows 12 made of nylon (may be a wire core), and each is fixed by a clip.

The bellows 12 passes through an opening 10b formed in the sub-tank cover 10 and is connected to a discharge port 1a as a fuel pipe of the fuel pump 1 and a discharge pipe 7 as a communication pipe. Not fixed.

The bracket 11 is provided so as to extend downward from the bottom surface side of the cover 5, and has a rectangular projection 9 b (the second projection) formed on the outer periphery of the upper end of the sub-tank main body 9 at the center near the lower end.
Window 11a is formed.

The window 11a has a lateral width large enough to fit the projection 9b, and is formed to be long in the vertical direction. Accordingly, the sub-tank 2 is supported by the window 11a of the bracket 11 and the projection 9b of the sub-tank main body 9 to be engaged with each other so that the movement in the circumferential direction is restricted with respect to the bracket 11 and the sub-tank 2 is slidable in the vertical direction. ing.

The sub-tank 2 supported by the bracket 11 is urged downward by a spring 13 disposed between the cover 5 and the sub-tank cover 10 on the outer periphery of the return pipe 8,
It is pressed against the bottom of the fuel tank 3.

On the bottom surface of the sub tank main body 9, as shown in FIG.
An inflow port 14 through which fuel flows into the sub-tank 2 is formed.
A check valve 15 made of rubber is provided for opening and closing the inflow port 14 by a pressure difference between the inside and the inside.

The check valve 15 closes the inflow port 14 when the fuel level in the sub tank 2 is higher than the fuel level in the fuel tank 3, for example, and the fuel level in the fuel tank 3 Open the inlet 14 when it is higher than the surface by about 5 mm or more.

Near the center of the bottom surface of the sub-tank body 9, a rubber cushion 16 that is in contact with the bottom surface of the fuel tank 3 when the sub-tank 2 is supported by the bracket 11 and mounted in the fuel tank 3 is attached. . FIG. 3 is a bottom view of the fuel supply device.

A fuel gauge 17 for detecting the remaining amount of fuel in the fuel tank 3 is attached to the sub tank 2.

When the fuel gauge 17 indicates the point E (empty) of the fuel gauge, the float 17a that moves in accordance with the displacement of the fuel liquid level,
The sub-tank 9 is disposed so as to fit into a recess 9c formed at the bottom of the sub-tank main body 9. At this time (when indicating point E),
The float 17a and the float arm 17b of the fuel gauge 17 are provided so as to fit within the outer shape of the sub-tank 2, as shown in FIG.

In the sub-tank body 9, the fuel returned from the outside of the fuel tank 3 via the return pipe 8 is attached to a jet pump (described later) mounted on the bottom of the sub-tank body 9.
An introduction passage 19 leading to 18 and a supply passage 20 for supplying the fuel ejected from the jet pump 18 into the sub-tank 2 are provided integrally.

The introduction passage 19 is provided to extend from the bottom to the upper part of the sub-tank main body 9, and is connected to a nozzle (see FIG. 4) 18a of the jet pump 18 on the bottom side. The return pipe 8 is inserted into the upper end of the introduction passage 19 in a liquid-tight manner.

The supply passage 20 is connected to a throat portion 18b (see FIG. 4) of the jet pump 18 at the bottom of the sub-tank main body 9, and is provided with a downstream end opening upward in the sub-tank 2.

As shown in FIG. 4, the jet pump 18 has a nozzle 18a for ejecting surplus fuel returned through the return pipe 8 and the introduction passage 19 at a high speed, and an opening facing the nozzle 18a at a predetermined distance. And a throat section 18b having a section. The nozzle 18a protrudes outward from the bottom surface of the sub-tank main body 9, so that the opening of the throat portion 18b opens to the outside of the sub-tank 2.

When jetting excess fuel returned through the return pipe 8 and the introduction passage 19 from the nozzle 18a at high speed, the jet pump 18 causes the fuel at the bottom of the fuel tank 3 to be discharged together with the excess fuel by the jet action of the fuel. Throat part
It sucks into 18b.

As shown in FIG. 5, the throat portion 18b is provided in a flat shape having an opening height (H1) of 3.0 mm and an opening width (W1) of 9 mm, and extends from the opening to the supply passage 20. Length 35
is set to mm.

The nozzle 18a is formed in a vertically long rectangular shape having an opening height (H2) of 1.8 mm and an opening width (W2) of 1.0 mm.

The distance between the nozzle 18a and the throat portion 18b is set to 5.0 mm.

Next, the operation of the vehicular fuel supply device having the above configuration will be briefly described.

The fuel tank 3 is inserted into the sub tank 2 through a check valve 15.
The fuel inside is being supplied.

When the fuel pump 1 is energized, fuel in the sub tank 2 is sucked through the filter 6 and supplied to the internal combustion engine through the discharge pipe 7.

Most of the fuel supplied to the internal combustion engine becomes surplus fuel and is led into the fuel tank 3 via the return pipe 8. The fuel returned via the return pipe 8 is guided to the jet pump 18 through the introduction passage 19, and is ejected at a high speed from the nozzle 18a.

The fuel at the bottom of the fuel tank 3 is sucked into the throat 18b together with the fuel ejected from the nozzle 18a, and
Through the sub-tank 2.

During the operation of the fuel pump 1, the fuel is supplied into the sub-tank 2 by the operation of the jet pump 18,
A substantially constant amount of fuel is stored in the sub tank 2.

Next, effects of the fuel supply device of the present embodiment will be described.

a) Regarding the throat portion 18b of the jet pump 18.

In this embodiment, the throat portion 18b of the jet pump 18 has a flat shape, so that the throat portion 18b has the same opening area as the throat portion 18b as compared with a conventional throat portion having a circular cross-sectional shape. Height (H1) can be reduced.

As a result, it is possible to mount the fuel pump 1 above the jet pump 18 without significantly raising the mounting position of the fuel pump 1, so that the mountability of the fuel pump 1 can be improved compared to the related art. .

b) The bellows 12 connected to the discharge port 1a of the fuel pump 1 and the discharge pipe 7.

When the discharge port 1a of the fuel pump 1 and the discharge pipe 7 are connected by fitting to a cylindrical support formed integrally with the sub-tank cover 10, a seal member made of a fluororesin incorporated in the support is used. Cost increases.

On the other hand, by using the bellows 12 as in the present embodiment, the cost can be reduced, and
The assemblability at the time of connecting the discharge port 1a of the fuel pump 1 and the discharge pipe 7 can be improved.

Moreover, variations in tank depth can be absorbed without positioning the discharge port 1a and the discharge pipe 7 with high accuracy. As a result, even if the tank depth varies, the sub-tank is always positioned at the lowermost portion of the fuel tank, and the opening of the fuel tank can be closed by the cover with a simple configuration.

c) About the fuel gauge 17.

When the float 17a of the fuel gauge 17 is assembled so as to protrude from the outer shape of the sub-tank 2, when the sub-tank 2 is inserted into the fuel tank 3,
It is necessary to insert while tilting, so the mountability is poor.

In this embodiment, when indicating the E point (empty) of the fuel gauge,
Since the float 17a and the float arm 17b of the fuel gauge 17 are provided so as to fit within the outer shape of the sub-tank 2, it is not necessary to insert the sub-tank 2 while tilting it when inserting it into the fuel tank 3. Can be improved.

In addition, since the protrusion of the float 17a is eliminated, damage to the fuel gauge 17 during assembly can be reduced.

(Modification) In the above embodiment, the dimensions of the nozzle 18a and the throat portion 18b described in the description of the jet pump 18 are merely examples, and are not limited to these numbers.

[Brief description of the drawings]

1 to 5 show an embodiment of the present invention.
1 is a longitudinal sectional view of a fuel supply device for a vehicle, FIG. 2 is a perspective view of a sub tank, FIG. 3 is a bottom view of a sub tank supported by a bracket, FIG. 4 is a perspective view of a jet pump, and FIG. FIG. 4 is a diagram showing a cross-sectional shape of an opening of a nozzle and a throat portion. In the figure, 1 ... fuel pump, 2 ... sub tank 3 ... fuel tank, 8 ... return pipe 18 ... jet pump, 18a ... nozzle 18b ... throat section

Continuation of front page (58) Field surveyed (Int.Cl. ⁶ , DB name) F02B 37/18 F02B 37/007

Claims (2)

(57) [Claims] 1. A fuel tank, a fuel pump mounted in the fuel tank, a sub-tank accommodating the fuel pump in the fuel tank, and a surplus fuel of fuel discharged from the fuel pump in the sub-tank. And a nozzle that is assembled to the bottom of the sub-tank and ejects the fuel returned from the return pipe, and opens to the outside of the sub-tank opposite to the nozzle, together with the fuel ejected from the nozzle. A jet pump comprising a throat portion for guiding the fuel sucked from the outside of the sub-tank into the sub-tank, wherein the throat portion has a flat shape. An opening for inserting the sub-tank in the fuel tank; a cover having a communication pipe for closing the opening and communicating the inside of the sub-tank with the outside of the fuel tank; and supporting the sub-tank. A fuel supply device for a vehicle provided with a bracket, wherein a fuel pipe toward the cover is provided in the sub-tank, and the communication pipe and the fuel pipe are connected by a telescopic bellows. Claims to be made (1)
A fuel supply device for a vehicle according to claim 1.