JP2819667B2 - 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 Application Laid-Open (JP-A) No. H11-163873).
See 1-159456).

The fuel supply device having such a sub-tank transfers the fuel in the fuel tank into the sub-tank and sends the fuel stored in the sub-tank to the outside of the fuel 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.

In the fuel supply device equipped with such a jet pump, when the fuel in the fuel tank is supplied into the sub-tank by the jet pump, water droplets condensed on the inner wall of the fuel tank flow into the sub-tank together with the fuel, and gradually the sub-tank is It will collect at the bottom.

Therefore, in order to prevent the water collected at the bottom of the sub-tank from being sucked when the fuel pump is operated, the intake port of the fuel pump has a twill-woven type fuel filter that separates water and fuel and sucks only the fuel. Are arranged.

[Problems to be Solved by the Invention] Twill weave type fuel filters can be used even when exposed to water.
When the ratio of fuel to accumulated water is high, only fuel can be passed without passing water, but the amount of water accumulated at the bottom of the sub tank gradually increases, and the water reaches a certain height When the above is reached, only water passes without fuel.

Therefore, in the conventional fuel supply device using the twill-type fuel filter, when the amount of water accumulated in the sub-tank increases, the fuel pump sucks only water at a stretch, which may cause engine stall.

The present invention has been made based on the above circumstances, and an object of the present invention is to provide a vehicle fuel supply device that prevents water accumulated in a sub tank from being sucked into an engine at one time.

Means for Solving the Problems In order to achieve the above object, the present invention provides a fuel tank having an opening in a wall surface and having a cover closing the opening, A sub-tank to be inserted, a fuel pump housed in the sub-tank, for pumping the fuel in the sub-tank to the outside of the fuel tank, and a fuel supply unit for supplying the fuel in the fuel tank to the sub-tank, A fuel filter of a plain weave type disposed at a bottom portion of the sub-tank to filter fuel sucked into the fuel pump; and a stay fixed to the cover and supporting the sub-tank in the fuel tank. The sub-tank includes a sub-tank main body having an open upper end, and a sub-tank cover for closing an upper end opening of the sub-tank main body. Engagement piece is provided on the periphery of the Kukaba enters inside the sub-tank main body,
There is a predetermined gap between the engagement piece and the inner peripheral surface of the sub tank main body, and a projection is provided on an outer surface of the engagement piece. The stay is a window that can engage with the projection. And inserted into the inside of the sub-tank body through a gap between the engagement piece and the inner peripheral surface of the sub-tank body, and supporting the sub-tank by fitting the projection to the window. Is a technical means.

[Operation and Effect of the Invention] The fuel supply device for a vehicle according to the present invention having the above-described configuration is configured such that the fuel filter disposed at the bottom in the sub tank is of a plain weave type, so that when the fuel pump is operated,
The water accumulated in the sub-tank is gradually sucked in together with the fuel. Since the water discharged from the fuel pump together with the fuel is very small, it can be evaporated in the engine.

In this way, the water accumulated in the sub-tank is gradually sucked together with the fuel by the plain weave type fuel filter, so that a large amount of water is not sucked into the engine at one time unlike the conventional case, and therefore, the engine stall is reduced. Can be prevented.

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

1 is a sectional view of a fuel supply device for a vehicle, and FIG. 2 is a partial sectional view of a side surface of a sub-tank containing a fuel pump.

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

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

When the fuel pump 2 is energized, the fuel pump 2 sucks the fuel in the sub-tank 3 through a plain-woven type fuel filter 6 disposed at the bottom in the sub-tank 3, and discharges the fuel from the discharge port 2 a of the fuel pump 2. The sucked fuel is pumped out of the fuel tank 1 through a pipe 7. The pumped fuel is
The fuel is supplied to the combustion chamber of the engine via a fuel injection valve (not shown), and excess fuel is guided again into the sub-tank 3 through the return pipe 8. In FIG. 1, reference numeral 9 denotes an air vent pipe for supplying fuel into the fuel tank 1. Numeral 10 is a lead wire connected from the connector to the fuel pump 2.

The sub-tank 3 includes a resin-made sub-tank main body 11 having an upper end opened to accommodate the fuel pump 2, and a sub-tank cover 12 for closing the opening of the sub-tank main body 11. Stay (described later)
Supported by 13.

The sub-tank main body 11 has a substantially circular opening at the upper end, and can store about 700 cc of fuel inside with the fuel pump 2 accommodated therein.

As shown in FIG. 2, a rectangular cut-out locking window 14 is provided at three places in the circumferential direction on the upper outer peripheral wall of the sub-tank main body 11.

On the other hand, as shown in FIGS. 3 and 4, when the sub-tank cover 12 is placed over the opening of the sub-tank main body 11, the sub-tank main body 11 Three claws 15 are provided for locking from inside.

Therefore, this sub tank cover 12 is
After covering the opening 11, the claw 15 is fixed to the sub-tank main body 11 by fitting three claws 15 into the locking window 14 and locking them.

The sub-tank cover 12 is provided with three engaging pieces 16 supported by a stay 13 at three positions symmetrical to the three pawls 15 as shown in FIG. There is a slit-shaped gap between each of the sub-tank 11 and the inner peripheral surface of the sub-tank main body 11. The engagement piece 16 is formed to extend downward, and has a claw-shaped projection 16a formed on the outer peripheral surface. The engagement piece 16 is provided slightly closer to the center than the outer periphery of the sub-tank cover 12 so as to enter the inside of the sub-tank main body 11 when the sub-tank cover 12 is placed over the opening of the sub-tank main body 11. (See FIG. 3).

FIG. 3 is a top view of the sub tank cover 12.
FIG. 4 is a side view of the sub-tank cover 12 viewed from the direction A in FIG.

A stay 13 for supporting the sub-tank 3 is fixed to the bottom surface of the cover 5 by welding and extends downward.

Each stay 13 has an engagement piece provided on the sub tank cover 12.
A vertically long window 17 that engages with the 16 projections 16a is formed.
The window 17 has a lateral width large enough to fit the projection 16a, and is formed to be long in the vertical direction.
This stay 13 is, as shown in FIGS. 2 and 3,
The sub-tank body 11 passes through a gap provided between the engagement piece 16 of the sub-tank cover 12 and the inner peripheral surface of the sub-tank body 11.
Each stay 13 is inserted from the outer peripheral side of the engagement piece 16
The sub-tank 3 is supported by fitting the windows 17 into the projections 16a.

At the upper end of each window 17, a rectangular stopper 18 projecting inward is provided. This stopper 18
When the window 17 is formed by punching or the like, the window 17 is formed by raising a portion left uncut in a rectangular shape inward.

Accordingly, the sub-tank 3 is restricted from moving in the circumferential direction with respect to the stay 13, and is slidably supported in a predetermined range in the vertical direction. The vertical movement of the sub-tank 3 is restricted by the upper end surface of the sub-tank cover 12 abutting against the stopper 18, so that the upward movement is restricted. Movement to is regulated.

In addition, as shown in FIG.
Of the sub-tank cover 12 may be made to function.

The sub tank 3 supported by the stay 13 is urged toward the bottom of the fuel tank 1 by a spring 19 between the cover 5 and the sub tank cover 12. The lower end of the spring 19 is fitted around the outer periphery of a boss 20 formed substantially at the center of the sub tank cover 12, and the upper end is
It is fitted around the outer periphery of the spring retainer 21 fixed to the cover. The mounting load of the spring 19 is set to 8 kgf or less.

On the inner periphery of the boss portion 20 formed on the sub-tank cover 12, there is provided a cylindrical ring connecting the discharge port 2 a of the fuel pump 2 and the discharge pipe 7 in a liquid-tight manner through seal rings (fluororesin) 22 and 23. Support 24 is provided.

The support 24 is not fixed to the sub-tank cover 12, but is mounted in a floating state with a gap between the inner periphery of the boss 20 and the outer periphery of the support 24. As shown in FIG. 1, a flange-shaped projecting portion 24a is provided on the outer periphery of the support 24. When the projecting portion 24a comes into contact with the inner surface side of the sub tank cover 12, the support 24 is provided. Is prevented from going upward.

As shown in FIG. 6, the seal ring 23 of this embodiment
A recess 23a having a semicircular cross section is formed over the entire outer peripheral surface, and has a semicircular space over the entire circumference between the concave portion 23a and the inner wall of the support 24. The seal ring 23 and the discharge pipe 7
Is slidably provided with a sliding resistance of 5 kgf or less.

A check valve (not shown) that allows fuel to flow into the sub tank 3 is provided on the bottom surface of the sub tank main body 11.

This check valve is opened and closed by a pressure difference between the inside of the sub tank 3 and the inside of the fuel tank 1.
When the fuel level in the fuel tank 1 is higher than the fuel level in the fuel tank 1, it is closed. When the fuel level in the fuel tank 1 is higher than the fuel level in the sub-tank 3 by about 5 mm or more, it is opened.

The sub-tank main body 11 has an introduction passage 26 for guiding the fuel returned through the return pipe 8 to a jet pump (described below) 25 formed at the bottom of the sub-tank main body 11, and the fuel discharged from the jet pump 25. Is supplied integrally into the sub tank 3.

The introduction passage 26 is provided extending from the bottom of the sub-tank main body 11 to the top, and the nozzle 25 of the jet pump 25 is provided on the bottom side.
a has been contacted. The return pipe 8 is inserted into the upper end of the introduction passage 26 in a liquid-tight manner.

The supply passage 27 is connected to the discharge passage 25b of the jet pump 25 at the bottom of the sub-tank main body 11, and has a downstream end (upper end in FIG. 1) opened upward in the sub-tank 3.

The jet pump 25 discharges excess fuel returned through the return pipe 8 and the introduction passage 26 from the nozzle 25a at a high speed, and the jet flow action causes the fuel tank to be discharged into the discharge passage 25b opened to the outside of the sub-tank 3. The fuel is supplied to the supply passage 27 while sucking the fuel at one bottom portion, and is a fuel supply means of the present invention.

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

The fuel in the fuel tank 1 is supplied into the sub tank 3 via a check valve.

When the fuel pump 2 is energized, the fuel in the sub tank 3 is sucked through the fuel 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 guided into the fuel tank 1 via the return pipe 8. The fuel returned via the return pipe 8 is guided to the jet pump 25 through the introduction passage 26, and is discharged at high speed from the nozzle 25a.

The fuel at the bottom of the fuel tank 1 is sucked into the discharge passage 25b together with the fuel discharged from the nozzle 25a, and is supplied to the supply passage 27b.
Through the sub-tank 3.

During the operation of the fuel pump 2, fuel is supplied into the sub-tank 3 by the function of the jet pump 25, so that a substantially constant amount of fuel is stored in the sub-tank 3.

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

a) Regarding the fuel filter 6.

Since the fuel supply device of this embodiment has a structure in which the fuel in the fuel tank 1 is sucked into the sub-tank 3 by the jet pump 25, water droplets condensed on the inner wall of the fuel tank 1 are sucked into the sub-tank 3 together with the fuel. However, when the fuel pump 2 is operated, the water accumulated in the sub-tank 3 gradually passes through the fuel filter 6 together with the fuel when the fuel pump 2 is operated, and is sucked into the fuel pump 2 by employing the flat-woven type fuel filter 6. . Since the water discharged from the fuel pump 2 together with the fuel is very small, it can be evaporated in the engine.

As a result, unlike the conventional fuel supply device using a twill-type fuel filter, water accumulated in the sub-tank 3 is not sucked into the engine at one time, and the occurrence of engine stall is prevented. Can be.

b) About the support structure of the stay 13 and the sub tank 3.

In this embodiment, the engagement piece 16 of the sub-tank cover 12 is provided slightly closer to the center than the outer circumference of the sub-tank cover 12 so that the stay 13 can be inserted into the inner peripheral side of the sub-tank main body 11 to support the sub-tank 3.

In the case of a structure in which the stay 13 (or a bracket) supports the outside of the sub tank 3, it is necessary to provide a projection on the outer wall of the sub tank 3.
On the other hand, the outer diameter of the sub tank 3 must be made smaller by the amount of the protrusion.

Therefore, as described above, the stay 13 is
If the structure supports the sub-tank 3 by being inserted into the inner peripheral side of the sub-tank 3, the outer diameter of the sub-tank main body 11 can be set larger than that of the structure supporting from the outside of the sub-tank 3. As a result, a sufficient sub-tank volume can be ensured even when the fuel tank is mounted on a low-height fuel tank.

c) About the mounting structure of the support 24.

Since the support 24 is not fixed to the sub-tank cover 12 and is assembled in a floating state, the vibration of the fuel pump 2 can be prevented from being transmitted from the support 24 to the sub-tank cover 12. As a result, support 24 with sub-tank cover
The noise transmitted to the vehicle interior can be reduced as compared with the case where it is formed integrally with the motor vehicle 12.

d) Shape of seal ring 23.

The seal ring 23 assembled in the support 24 supports the fuel pressurized by the fuel pump 2 without leaking at the contact surface with the discharge pipe 7 and slidably moves the discharge pipe 7 up and down. It is.

However, conventional seal rings (made of fluororesin)
By sucking and swelling the fuel (gasoline) discharged from the fuel pump 2 and expanding on the sliding surface side with the discharge pipe 7,
The sliding resistance with the discharge pipe 7 increases, making the vertical movement of the discharge pipe 7 impossible.

Therefore, in the present embodiment, by forming a recess 23a having a semicircular cross section over the entire outer peripheral surface of the seal ring 23, and forming a semicircular space between the inner wall surface of the support 24, Even if you swell by inhaling fuel (gasoline), support 24
By expanding so that the space with the inner wall surface is reduced, it is possible to maintain the sealing property with the discharge pipe 7 and to enable the discharge pipe 7 to move up and down smoothly.

e) About the stopper 18 provided on the stay 13.

2. Description of the Related Art In a fuel supply device including a sub tank, a structure for supporting the sub tank slidably in a vertical direction is generally used.

However, in the conventional fuel supply device, the lower position of the sub tank 3 with respect to the stay 13 is determined by the support structure of the sub tank 3 and the stay (or bracket) 13, but the upward movement of the sub tank 3 is restricted. Absent.

Therefore, for example, when the sub-tank 3 slides upward and the fuel pump 2 is operated in a state where the discharge port 2a of the fuel pump 2 and the discharge pipe 7 are in contact with each other in the support 24, the vibration of the fuel pump 2 Is directly transmitted to the discharge pipe 7 to increase noise. In the worst case, the discharge port 2a of the fuel pump 2 may be damaged.

Alternatively, the lead wire 10 connected to the fuel pump 2
There is also a possibility that the wire will be broken by being sandwiched between the sub tank cover 12 and the fuel pump 2.

Therefore, by providing the stopper 18 on the stay 13 as in the present embodiment, the upward movement of the sub tank 3 is restricted, and the upper position of the sub tank 3 with respect to the stay 13 can be determined. As a result, the above-described problems can be prevented.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a vehicle fuel supply device of the present invention, FIG. 2 is a side partial cross-sectional view of a sub-tank containing a fuel pump,
FIG. 3 is a top view of the sub-tank cover, FIG. 4 is a side view of the sub-tank cover viewed from the direction A in FIG. 3, FIG. 5 is a perspective view showing a modification of the stopper, and FIG. FIG. In the drawing, 1 ... fuel tank 2 ... fuel pump 3 ... sub tank 5 ... cover 6 ... fuel filter 11 ... sub tank body 12 ... sub tank cover 13 ... stay 16 ... engaging piece 16a ... projection 17 …… Window 25 …… Jet pump (fuel supply means)

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-1-159456 (JP, A) JP-A-50-130064 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) B01D 35/02 F02M 37/10 F02M 37/22

Claims (1)

(57) [Claims] (A) a fuel tank having an opening in a wall surface and having a cover closing the opening; (b) a sub-tank inserted into the fuel tank through the opening; (c) A fuel pump housed in the sub-tank for pumping fuel in the sub-tank to the outside of the fuel tank; (d) fuel supply means for supplying fuel in the fuel tank to the sub-tank; A plain weave type fuel filter disposed at the bottom in the sub-tank and filtering fuel sucked into the fuel pump; and (f) a stay fixed to the cover and supporting the sub-tank in the fuel tank. The sub-tank is a sub-tank body having an open upper end,
A sub-tank cover for closing an upper end opening of the sub-tank main body, and an engagement piece that enters the inside of the sub-tank main body is provided at a peripheral edge of the sub-tank cover. A protrusion is provided on an outer surface of the engagement piece, and the stay has a window capable of engaging with the protrusion, and the stay is provided between the engagement piece and the sub tank main body. A fuel supply device for a vehicle, which is inserted into the inside of the sub-tank main body through a gap between itself and a peripheral surface, and supports the sub-tank by fitting the projection to the window.