JPH09268956A - Fuel supplying device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To ensure a large volume of fuel which is necessary for starting of a fuel pump by forming an erecting upward the suction port side of the fuel pump provided inside of a fuel tank, and arranging a fuel liquid surface holding means for accumulating fuel in the capacity part of the erecting part. SOLUTION: A fuel supplying unit 11 is installed on the opening part of the upper tank 4 of a fuel tank, and it is arranged so as to push from the upper tank 4 toward the bottom of a fuel tank. A filter housing 6 is arranged inside of an auxiliary tank cover body 13, and a fuel pump 14 is arranged on the center side of the filter housing 6. A suction filter 31 including an oil film forming filter 33 on the inlet side of the suction pipe 18 of the fuel pump 14 in a shape erected vertically upward a container so as to form as a liquid surface holding means 32, a check valve 34 is arranged upward the oil film forming filter 33, and fuel of about 100 to 300cc which is necessary for starting of the fuel pump 14 is accumulated in the erecting part of the suction filter 31.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel supply device having a fuel pump for pumping fuel in a fuel tank.

[0002]

2. Description of the Related Art As a method of supplying fuel into a sub tank of a fuel tank mounted on a vehicle, US Pat.
18, 4750522, 4971017, 507084
The patent gazettes of No. 9 are known. In these publications, a fuel pump for supplying fuel to an engine and a sub-tank are integrated to improve the mountability of the integrated fuel pump in the fuel tank. In addition, a valve that connects the inside and outside of the sub tank inside the fuel tank is provided at the bottom of the sub tank, and this valve can be opened by a minute pressure. If there is a small amount of fuel in the fuel tank at the completion of vehicle assembly, some of this small amount of fuel may flow into the sub tank through the valve, and the fuel pump may pump up the fuel in this sub tank. You can do it.

[0003]

For example, when a vehicle is parked for a long period of three to four weeks, the fuel in the sub tank leaks out of the sub tank from the valve during that time, and the fuel in the sub tank is leaked during the subsequent start. The engine may not be able to be started because it is too small. Japanese Unexamined Patent Publication No. 7-63133 discloses a device in which a subtank in a fuel tank is equipped with a diaphragm valve to secure fuel in a fuel storage tank for a long period of time. According to the structure in which the fuel storage tank is provided, there is a problem in that the cost is increased by providing a diaphragm valve. Further, the device for storing the fuel pumped up by the fuel pump in the fuel tank is complicated and expensive.

Further, Japanese Patent Laid-Open No. 7-180632 discloses that
The fuel tank is equipped with a mesh filter, and the vapor separated from the return fuel returned to the fuel tank is collected in the return fuel chamber formed in the upper part inside the filter body, and the pressure in the return fuel chamber is more than a predetermined pressure. Then, the one-way valve is opened, the vapor is discharged from the return fuel chamber to the upper space inside the tank body, and only the fuel liquid of the return fuel is sucked into the fuel pump and supplied to the engine side. . This fuel supply device has a function of removing the vapor in the fuel pumped up by the fuel pump, but does not have a function of ensuring the fuel for a long period at the pump inlet side for pumping the fuel pump.

Further, there is no known fuel storage device which secures a large amount of fuel, for example 300 cc, for a long period of time, for example, for 3 to 4 weeks on the suction port side of the fuel pump in the fuel tank. SUMMARY OF THE INVENTION An object of the present invention is to provide a fuel supply device that always secures fuel that can be started by the fuel pump on the suction port side of the fuel pump in the fuel tank. Another object of the present invention is to
It is an object of the present invention to provide a fuel supply device that always secures a fuel amount capable of starting the fuel pump on the suction port side of the fuel pump even if the vehicle leans.

[0006]

According to the fuel supply device of the first aspect of the present invention, a fuel tank for storing fuel, a fuel pump provided in the fuel tank for pumping up the fuel in the fuel tank, The fuel tank includes a sub-tank that is provided so as to cover the fuel pump and has a fuel intake port that takes in fuel into the fuel tank from below, a pump filter that is provided inside the sub-tank, and a flange that fixes the sub-tank to the fuel tank. Then, a fuel liquid level holding means is formed so as to rise upward on the suction port side of the fuel pump, and the fuel is stored in the volume portion of this rising portion. This makes it possible to secure a large amount of fuel required for starting the fuel pump in the fuel tank with a simple configuration. According to this fuel supply device, the fuel can be held for a long period of time at the high fuel liquid level position where the fuel on the inlet side of the fuel pump in the fuel tank can be pumped up.

According to the fuel supply device of the second aspect,
Since the passage that connects the fuel inlet at the bottom of the sub-tank to the inside of the sub-tank is formed by the passage wall, it is possible to secure the fuel inside the partition partitioned by the passage wall even if the fuel tank is inclined. According to the fuel supply device of claim 3, the flange has a return pipe that discharges to the fuel tank side, and the sub tank lid has a sliding seal portion that fits into the return pipe. improves.

According to the fuel supply device of the fourth aspect,
Since the jet pump is provided on the return side of the fuel pump, the fuel in the fuel tank can be pumped up into the sub tank by using the energy of the fuel discharged from the fuel pump. According to the fuel supply device of the fifth aspect, since the spring receiving portion of the flange projects toward the side opposite to the fuel tank, the spring is unlikely to be displaced with respect to the flange, so that the sub tank can be stably attached to the flange.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. (First Embodiment) A first embodiment of the present invention is shown in FIGS. 1, 2 and 7. The fuel supply unit 11 shown in FIG. 1 is pressed from the upper tank 4 (not shown) to the bottom of the fuel tank.

The resin flange 1 is attached to the opening of a metal upper tank 4. The flange 1 is formed with an electric connector 2 for receiving power and a supply pipe 3 for supplying fuel to the engine side. A sub tank 9 is provided inside the fuel tank of the flange 1. The sub tank 9
It is composed of a sub tank body 12 and a sub tank lid body 13 that covers an upper opening of the sub tank body 12. A filter housing 6 is provided inside the sub tank of the sub tank lid 13.

A fuel pump 14 is provided at the center of the filter housing 6. Suction port 15 of fuel pump 14
A bracket 17 is attached to the bracket 17, and a suction pipe 18 extends from the bracket 17 in an L shape. The discharge port 16 of the fuel pump 14 is connected to the filter housing 6 via a seal ring 19 around the discharge port 16.
The filter housing 6 accommodates the filter element 20 in a semi-cylindrical shape in a part of the outer peripheral portion of the fuel pump 14. The filter element 20 is fixed to the filter housing 6 with an adhesive 21. Sub tank lid 1
3, the snap-fit claw 21 has a sub-tank body 1
The two fitting holes 22 are elastically fitted. Fuel pump 14
The fuel that has passed through the fuel filter element 20 from the inside is supplied to the engine supply side at the branch portion 23 of the filter housing 6 and the return path 25 to be returned to the sub tank.
Divided into A pressure regulator 26 is attached to the return path 25 side, and a nozzle 27 is provided on the outlet side of the pressure regulator 26. The sub-tank body 12 has its snap-fit claw 28 elastically fitted in the fitting hole 29 of the flange 1.

Hereinafter, a plurality of main parts of the fuel supply unit 11 of the present invention will be sequentially described. (1) Suction Filter The suction filter 31 has a liquid level holding means 32 formed at the inlet side of the suction pipe 18 of the fuel pump 14 such that the container rises vertically upward. The liquid level holding means 32 is
An oil film forming filter 33 having an opening of about 30 to 50 μm is provided on the inlet side of the suction pipe 18 so as to rise upward. A check valve 34 is provided above the oil film forming filter 33. The bottom portion 51 of the oil film forming filter 33 is located at a position lower than the labyrinth wall passage bottom portion 35 described later.

The suction filter 31 has a rising shape and creates a state in which this portion is filled with about 100 to 300 cc of fuel. As a result, the fuel filled in the suction filter 31 can be sucked into the fuel pump 14 through the suction pipe 18. For suction filters, open the filter material 3
An oil film strength experiment was carried out for a 0 μm plain weave and a 60 μm plain weave. The result is as shown in FIG. The types of mesh of the suction filter include plain weave (opening 30 μm), twill weave (opening 30 μm)
m), plain weave (opening 30 μm) + tatami weave (opening 100)
.mu.m), twill weave (30 .mu.m) + tatami weave (100 .mu.m), and the above double mesh can improve the clogging life. In addition, the suction filter 31
The surface area itself can be reduced.

(2) Maze Structure A maze structure is formed at the bottom of the sub-tank 9 so that the fuel taken into the sub-tank 9 from the fuel inlet 36 formed at the bottom of the sub-tank 9 does not escape when the liquid surface is inclined. There is.
This maze structure includes an intake hole 36, a throat portion 43, a labyrinth wall bottom 35, a semicircular labyrinth wall 37, and a labyrinth wall end 38. With this maze structure, as shown in FIG. 2, even when the fuel supply unit 11 is inclined, the maze wall 3
The fuel inside 7 is sucked from the suction port 15 of the fuel pump 14.

(3) Sliding seal The pipe 52 protruding inside the supply pipe 3 of the flange 1.
An annular sliding seal member 39 attached to the sub-tank lid 13 is attached to the outer peripheral portion of so as to be slidable in the longitudinal direction of the pipe. (4) Jet Pump The nozzle 27 of the jet pump is provided integrally with the sub tank 9 via the O-ring 42. The inner diameter of the nozzle 27 is set between 1.0 and 3.6 mm, and the inner diameter of the throat portion 43 of the jet pump is set between 4 and 13 mm. The valve 40 provided at the fuel intake port 36 of the sub tank 9 has an umbrella shape and is made of FKM or fluorosilcon.

A valve 40 is provided at the fuel inlet 36 formed at the bottom of the sub-tank 9, and the negative pressure generated by the jet flow of the return fuel ejected from the nozzle hole 30 of the nozzle 27 causes the fuel from the outside of the sub-tank 9. Fuel is sucked into the sub tank 9 through the intake port 36. Accordingly, the fuel can be sucked from the outside of the sub tank inside the fuel tank to the inside by the jet flow of the return fuel.
Therefore, when the fuel pump 14 is driven, the sub tank 9 is always filled with the amount of fuel required for the fuel pump 14 to suck.

(5) Spring receiving member The sub-tank lid 13 is biased downward by the compression coil spring 41 with respect to the flange 1. As a result, the sub-tank 9 is constantly pressed against the bottom surface of the tank to reduce the remaining amount of ineffective fuel and to position the sub-tank in the fuel tank. Rattling of the sub tank 9 with respect to the flange 1 is prevented. Spring receiving projection 4
It is the compression coil spring 4 that makes 5 and 46 convex.
This is because the axial length of 1 can be stably attached.

The seal ring 19 and the sliding seal 44 are F
KM, H-NBR, fluorosilicone or the like is used. The sub tank 9 is preferably made of carbon-containing POM or POM. A convex portion 45 that holds one end of the compression coil spring 41 is provided on the lower surface of the flange 1, and a convex portion 46 that holds the other end of the compression coil spring 41 is provided on the upper surface of the sub tank lid 13.

Next, the flow of fuel in this fuel supply unit will be described. When the fuel pump 14 is driven, the fuel discharged from the discharge port 16 of the fuel pump 14 is returned to the fuel tank through the filter element 20 and the fuel supplied to the engine side at the branch portion 23 and the pressure regulator 26. It is divided into fuel and fuel. Fuel supplied to the engine is supplied to the engine from the supply passage 24 through a passage in the supply pipe 3. The return fuel flowing to the pressure regulator 26 side is ejected from the injection hole 30 of the nozzle 27. At this time, the fuel is sucked from the outside of the sub-tank 9 through the fuel intake port 36 by the fuel suction action due to the negative pressure generated by the jet flow, and the throat portion 43
Suck it into the sub tank 9. The fuel sucked into the sub tank enters the suction filter 31, passes through the suction pipe 18, and is sucked through the suction port 15 to the fuel pump 1.
It is discharged from the discharge port 16 through the inside of the nozzle 4.

Upon completion of the assembly of the vehicle equipped with this fuel supply device, for example, an amount of about 6 which allows initial running in the fuel tank.
About 10 liters of fuel is supplied. At this time, the fuel liquid level in the fuel tank is higher than the position of the labyrinth wall passage bottom portion 35, and the valve 40 is opened by a slight pressure difference between the inside and outside of the sub tank 9. Since the liquid level of the fuel is higher than that of the bottom portion 35 of the maze wall passage, the fuel passes from the fuel intake port 36 to the throat portion 43 and the maze wall 37, and from the maze wall end 38 to the suction filter 31 inside the sub tank 9. It flows into the bottom of the interior. At this time, when the suction pipe 18 of the suction filter 31 is filled with the fuel, the fuel pump 14 can suction and discharge the fuel, and pumps the fuel.

During normal running, fuel passes from the discharge port 16 through the filter element 20, and branches from the branch portion 23 of the filter housing 6 into the engine side flow path and the return side flow path, and the fuel flowing to the engine side flows into the supply pipe 3. Is supplied to the engine through. The fuel flowing to the return side is regulated by the pressure regulator 26 and flows into the nozzle 27. The fuel ejected from the nozzle hole 30 of the nozzle 27 becomes a jet and flows into the throat portion 43. At this time, the pressure energy is changed to the flow energy by the fluid energy conversion, and the fuel outside the sub tank 9 is sucked into the sub tank 9. As a result, the liquid level in the sub-tank 9 rises to the outside of the sub-tank 9, and the inside of the sub-tank 9 is filled with fuel. During normal driving, the return flow rate is sufficiently large compared to the engine consumption, so the sub tank 9
Even if there is no fuel outside, the fuel stored in the sub tank 9 does not cause a breathing phenomenon during turning, and stable fuel supply can be performed.

When the vehicle is left on a sloping ground for a long period of time, since the suction filter 31 has a fine opening as shown in FIG. 3, the oil film strength is improved, so that the suction filter 31 inside the sub-tank 9 is improved. The state of being filled up to the upper part is maintained for a long time, and 100 to 300 cc of fuel can be secured. That is, in order to secure a fuel amount of about 100 to 300 cc when the vehicle is left on a sloping land for a long period of time, since the sub tank 9 is filled by the above operation, the suction filter 3 is caused by the head difference.
The inside of 1 is also filled with fuel. At this time, the air stored in the suction filter 31 is discharged from the check valve 34.

When the vehicle is parked, the check valve 4
Even if fuel leaks to the outside of the sub-tank 9 from 0, the suction filter 31 is sealed by the oil film strength because the openings of the suction filter 31 are made fine as shown in FIG.
The fuel in 1 can be retained for a long time. In the conventional technique, the fuel is secured only by the valve 40. Therefore, when the vehicle is left for a long period of three to four weeks, the fuel leaks from the valve 40 that opens with a slight pressure to lower the liquid level. Occurs,
There is a problem that the vehicle cannot be started after being left for three to four weeks.

In this embodiment, the function can be achieved at low cost because the sealing can be performed by using the natural phenomenon of the oil film as described above. Further, since the maze-shaped wall is provided at the bottom of the suction filter 31, fuel always exists at the bottom of the suction filter 31, so that the oil film is prevented from breaking due to surface tension. Further, under this condition, when vapor is generated in the suction filter 31, the vapor comes out from the check valve 34 to the outside.

According to this embodiment, since the sliding seal 39 is used, the height change of the position of the sub tank 9 in the fuel tank can be arbitrarily adjusted according to the height of the fuel tank. For a particularly short fuel tank in recent years, such a compact structure makes it possible to easily equip the sub tank 9 without routing a hose.

Further, in this embodiment, by providing the sliding seal 39, it is possible to follow the tank height change of about 30-40 mm in width even in a shallow fuel tank of about 160 mm. Furthermore, in this embodiment, the sliding seal 3
Since the thickness of 9 is increased and the sliding resistance is suppressed to about 2 kgf, it has the effect of damping the vibration of the fuel pump 14.
As a result, vibration of the flange 1 which causes noise in the vehicle interior can be reduced. Further, the fuel pressure applies a fuel pressure in a direction in which the flange 1 and the sub tank 9 are separated from each other, so that an auxiliary force of the compression coil spring 41 can be obtained.

(Second Embodiment) FIG. 4 shows a second embodiment of the present invention.
Shown in The second embodiment shown in FIG. 4 is an example in which the spring guide portion 49 formed on the flange 1 is convex upward. According to this embodiment, since the total length of the compression coil spring 41 can be made long, the following range of the fuel supply unit 11 in the tank height direction can be made large.

The other components are designated by the same reference numerals as those of FIG. (Third Embodiment) A third embodiment of the present invention is shown in FIG. FIG.
The third embodiment shown in is an example in which a valve is not provided in the fuel intake hole 36. A valve is not provided at the bottom of the sub tank 9.

This embodiment is effective for a fuel supply system having a specification in which it is not necessary to secure fuel for several days. That is, the check valve is abolished, and it is possible to secure fuel only when the vehicle is left for a long period of three to four weeks, thereby reducing the cost. (Fourth Embodiment) A fourth embodiment of the present invention is shown in FIG.

The embodiment shown in FIG. 6 is an embodiment in which the labyrinth wall structure is omitted from the embodiment shown in FIG. By not providing the structure of the maze wall in the sub tank, the structure in the sub tank is simplified and the cost can be reduced. The suction filter 31 and other components are the same as in the example shown in FIG.

[Brief description of drawings]

FIG. 1 is a sectional view showing a fuel supply device according to a first embodiment of the present invention.

FIG. 2 is a diagram showing a fuel level state when the fuel supply unit according to the first embodiment of the present invention is inclined when the vehicle is turning.

FIG. 3 is a diagram showing an experimental result of oil film strength of a suction filter.

FIG. 4 is a sectional view showing a fuel supply device according to a second embodiment of the present invention.

FIG. 5 is a sectional view showing a fuel supply device according to a third embodiment of the present invention.

FIG. 6 is a sectional view showing a fuel supply device according to a fourth embodiment of the present invention.

FIG. 7 is a plan view of the sub tank body according to the first embodiment of the present invention as seen from above.

[Explanation of symbols]

 1 Flange 6 Filter Housing 9 Sub Tank 11 Fuel Supply Unit 12 Sub Tank Main Body 13 Sub Tank Lid 14 Fuel Pump 15 Suction Port 16 Discharge Hole 17 Bracket 18 Suction Pipe 20 Filter Element 26 Pressure Regulator 31 Suction Filter 32 Liquid Level Holding Means 33 Oil Film Forming Filter 34 check valve 35 maze wall passage bottom 36 fuel intake 37 maze wall 38 maze wall end 39 sliding seal member 41 compression coil spring

Claims (5)

[Claims] 1. A fuel tank for storing fuel, a fuel pump provided in the fuel tank for pumping the fuel in the fuel tank, a fuel pump provided so as to cover the fuel pump, and the fuel is supplied from the bottom to the inside. In a fuel supply device including a sub-tank having a fuel intake port to be taken in, a pump filter provided inside the sub-tank, and a flange for fixing the sub-tank to the fuel tank, the fuel supply device rises upward to the suction port side of the fuel pump. A fuel supply device characterized in that it is provided with a fuel level holding means for storing fuel in the volume of the rising portion. 2. A check valve is provided at the fuel intake port at the bottom of the sub-tank, and a passage communicating from the fuel intake port to the inside of the sub-tank is formed by a passage wall. The fuel supply device described. 3. A fuel filter provided on an upper portion of the fuel pump, a filter housing which accommodates the fuel filter and is coupled to the sub tank, and a sub tank lid provided on the flange side with respect to the sub tank. The fuel supply device according to claim 1, wherein the flange has a return pipe that discharges toward the fuel tank, and the sub-tank lid has a sliding seal portion that fits into the return pipe. 4. The fuel discharged from the fuel pump through a filter is branched into a fuel on the external supply side and a fuel on the return side, and a jet pump is provided on the return side of the branch portion. Item 2. The fuel supply device according to item 1. 5. A fuel filter provided on an upper portion of a fuel pump, a filter housing which accommodates the fuel filter and is connected to the sub tank, and between the flange and the sub tank between the sub tank body and the sub tank lid. 2. The fuel supply device according to claim 1, further comprising a spring for adjusting the height of the flange according to the depth of the fuel tank, wherein the spring receiving portion of the flange projects toward the side opposite to the fuel tank.