JP2001140722A - Fuel supply device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve discharge performance by preventing vapor included in return fuel from being absorbed again into a fuel pump, to prevent occurrence of noise accompanied by return fuel injection to the inside of the fuel tank, and to prevent temperature rise in the fuel tank. SOLUTION: Fuel in the fuel tank is pressurized by the fuel pump, and also fuel regulated to a constant pressure by a pressure regulator is supplied to a fuel injection valve. Return fuel in the pressure regulator is made to flow back into the inside of the fuel tank through a return fuel passage. A wire mesh cylindrical body 10 comprises a wire mesh cylindrical body 10A, a one side closing member 10B and an other side closing member 10C. The wire mesh cylindrical body 10 is arranged in a cup body S, and also the one side closing member 10B is arranged to be abutted on the cup body S. A fuel return passage 24 is opened in the inside of the wire mesh cylindrical body 10A through the other side closing member 10C and also placed to the one side closing member 10B.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel pump in which a fuel in a fuel tank is pressurized by a fuel pump, the pressurized fuel is regulated to a constant fuel pressure by a pressure regulator, and the fuel is supplied to an engine via a fuel injection valve. More specifically, the present invention relates to a return fuel passage for returning fuel from a pressure regulator to a fuel tank.

[0002]

2. Description of the Related Art A return fuel passage in a conventional fuel supply system is shown in FIG. Opening T at the bottom of fuel tank T
A has a bottomed cup-shaped cup body S for closing the opening, which is fastened by a screw 1. The cup body has the following configuration. P denotes an electric fuel pump including a pump unit and a motor unit. The suction passage PA projects and opens downward, and the discharge passage PB projects and opens upward. A first filter 2 is disposed in the suction passage PA, and the first filter 2 serves to remove foreign substances contained in the fuel flowing from the fuel tank T into the fuel pump P. The discharge path PB is connected to the inflow path 3A of the second filter 3 disposed in the fuel tank T, and foreign matter contained in the fuel discharged from the fuel pump P is removed from the second filter 3. The fuel that is removed by the filter 3 and is cleaner is supplied to the fuel supply path 4 from the outflow path 3B of the second filter 3. The fuel supply path 4
Is open to the outside through the cup body S,
The fuel supply path 4 is connected to a fuel distribution pipe having a fuel injection valve (not shown). On the other hand, the fuel supply path 4 is connected to the pressure regulator R. In the pressure regulator R, the housing 20 is divided by a diaphragm 21 into a spring chamber 22 and a fuel chamber 23, and the fuel chamber has the fuel supply path 4 and the return fuel path 24 connected to the fuel tank T. A valve 25 for opening and closing a return fuel passage 24 opening to a fuel chamber 23 is integrally attached to the diaphragm 21. Here, when the fuel whose pressure is increased by the fuel pump P is supplied from the fuel supply passage 4 into the fuel chamber 23, the diaphragm 21 resists the spring force of the spring 26 contracted in the spring chamber 22 and the spring chamber 22. As a result, the valve opens the return fuel passage 24 so that the fuel pressure supplied to the fuel distribution pipe can be regulated to a predetermined constant fuel pressure. According to the valve 25 opening the return fuel passage 24 at the time of the pressure regulation, a part of the pressurized fuel supplied from the fuel supply passage 4 into the fuel chamber 23 is partially returned to the return fuel passage 2.
4 squirts vigorously into the fuel tank T including the cup body S.

[0003]

According to such a fuel supply device, the fuel pressure is greatly changed by the fuel pump P. In addition, the fuel supply path such as the fuel supply path 4 and the fuel distribution pipe disposed near the engine is largely heated by the heat of the engine in the hood of the vehicle. As a result, a large amount of vapor is contained and discharged in the fuel flowing back from the return fuel passage 24 into the fuel tank T.
Further, the temperature of the fuel flowing back from the return fuel passage 24 into the fuel tank T rises, and the temperature of the fuel in the fuel tank T rises. Here, when a large amount of vapor is discharged into the fuel tank T, the vapor is easily sucked into the pump section of the fuel pump P again through the first filter 2, and according to this, the pump discharges. Performance may be degraded, and stable fuel supply cannot be performed. Furthermore, when a large vapor is sucked into the fuel tank T, noise is generated, which is not preferable. Further, when the temperature of the fuel in the fuel tank T rises, low-distilled components in the fuel evaporate and are discharged to the outside of the fuel tank T, which is not desirable. It has a problem that the property cannot be obtained.

On the other hand, in order to solve the above-mentioned problem, it is considered to arrange a spongy metal member 5 which is randomly bent toward the opening of the return fuel passage 24.
According to this, although a deterrent effect on the vapor entering the first filter 2 is recognized, the following problem still remains. (1) The temperature rise in the fuel tank T cannot be suppressed. (2) The return fuel passage 24 is still in the fuel tank T
Since it opens directly into the inside, generation of noise in the fuel tank T is not suppressed. (3) The sponge-like member 5 needs to be arranged over substantially the entire circumference of the first filter 2. (If there is a portion that does not cover the first filter 2, the vapor may enter the first filter 2 through this space.) However, the first filter 2 is located at the bottom of the cup body S. It is extremely difficult to cover the entire periphery of the first filter 2 with the sponge-like member 5 because it is disposed in a narrow portion of the first filter 2, and it requires a large number of work steps. Even if it can be covered with the sponge-like member 5, it is more difficult to confirm the state.

[0005] The fuel supply device according to the present invention has been made in view of the above-mentioned problem, and the vapor contained in the return fuel flowing through the return fuel passage is sucked into the fuel pump again through the first filter. Deterring that. Suppress the rise in fuel temperature in the fuel tank. And to reduce noise generated when return fuel is injected into the fuel tank. It is an object of the present invention to provide a fuel supply device that can perform the following.

[0006]

In order to achieve the above object, a fuel supply device according to the present invention is characterized in that a lower opening of a fuel tank is closed by a cup having a cup shape with a bottom and fuel in the cup is supplied to the fuel tank. In the fuel supply device, the fuel is supplied to the fuel injection valve while the pressure is increased by the pump and the pressure is regulated to a constant pressure by the pressure regulator, and the return fuel of the pressure regulator is returned to the fuel tank through the return fuel passage. The wire mesh tubular body is formed by a wire mesh tubular portion having both ends opened, one side closing member and the other side closing member closing the opening, and the wire mesh tubular body is disposed in the cup body and the one side is closed. A closing member is disposed in contact with the cup body, and the return fuel passage is further opened in the wire mesh cylindrical portion via the other closing member and is arranged facing the one closing member. The first, characterized in that the.

[0007] In addition to the first feature, the present invention further comprises a first positioning portion provided on one side closing member of the wire mesh tubular body, and the first positioning portion provided on the cup body. The second feature is that the wire mesh tubular body is positioned and fixed to the cup body by inserting and arranging the wire mesh tubular body in the cup body.

[0008]

According to the first feature, the return fuel ejected from the return fuel passage is recirculated in the fuel tank through the wire mesh tubular body. The vapor contained in the return fuel is miniaturized when passing through the wire mesh tubular portion of the wire mesh tubular body, is cooled by the wire mesh tubular portion, and is discharged into the fuel tank. The miniaturized vapor is further cooled by the fuel in the fuel tank and disappears. Further, the velocity energy of the return fuel can be reduced when passing through the wire mesh tubular portion, and the noise due to the jet can be reduced. Further, the temperature of the return fuel ejected from the return fuel passage is increased by coming into contact with the wire mesh tubular portion and the one-side closing member, thereby absorbing the heat, and this heat is radiated to the atmosphere through the one-side closing member and the cup body. You. According to the second feature, the wire mesh tubular body is positioned and fixed by inserting the first positioning portion of the one-side closing member into the second positioning portion of the cup body. Can be improved.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of a fuel supply device according to the present invention will be described below with reference to FIG. Note that the same components as those in FIG. Return fuel passage 24
Are connected to the fuel tank T via the wire mesh tubular body 10. The wire mesh tubular body 10 will be described in detail with reference to FIG. The wire mesh tubular body 10 has a tubular wire mesh tubular portion 10A having both ends opened, one side closing member 10B and the other side closing member 10C closing both openings.
And The one-side closing member 10B has a disk or cylindrical shape for closing the lower opening of the wire mesh tubular portion 10A, and has a first positioning portion 10D facing upward at the center thereof.
In the present embodiment, the first positioning portion 10D is formed as a cylindrical concave portion facing upward. The other-side closing member 10C has a disk or cylindrical shape for closing the upper opening of the wire mesh tubular portion 10A, and has an opening 10E at the center thereof into which the fuel return passage 24 can be inserted. Further, the metal net tubular portion 10A is made of a metal material having a higher thermal conductivity than a synthetic resin material, filter paper, or the like (for example, iron, aluminum, an aluminum alloy, stainless steel, or the like).
Is woven in a mesh shape, and the size of the mesh is appropriately selected. Further, the one-side closing member 10B and the other-side closing member 10C are also formed of a synthetic resin material, a metal material having a higher thermal conductivity than filter paper, or the like.

The wire mesh tubular body 10 is disposed in the cup body S. At this time, the first positioning portion 10D of the one side closing member 10B of the wire mesh tubular body 10 is provided on the cup body S. 2 It is inserted and arranged in the positioning part SA. The second positioning portion SA is formed as a cylindrical protrusion projecting upward from the bottom SB of the cup body S. In other words, the cylindrical concave portion serving as the first positioning portion 10D of the one-side closing member 10B is inserted and arranged in the cylindrical projection serving as the second positioning portion SA of the cup body S. At a predetermined position.

On the other hand, the return fuel passage 24 is inserted and arranged in the opening 10E of the other-side closing member 10C. According to this, the return fuel passage 24 is inserted into the wire mesh tubular portion 10A via the other-side closing member 10C. It is opened and opens facing the one-side closing member 10.

What should be particularly noted here is that the one-side closing member 10B is disposed in contact with the cup body S when the metal mesh tubular body 10 is disposed in the cup body S. Specifically, the bottom surface 10F of the one-side closing member 10B is disposed in contact with the bottom portion SB of the cup body S, and the first side of the one-side closing member 10B is
The cylindrical concave portion serving as the positioning portion 10D is disposed in contact with the cylindrical protrusion serving as the second positioning portion SA of the cup body S.

Next, the operation will be described. When the fuel pump P is driven in association with the operation of the engine, the fuel in the cup body S connected to the fuel tank T is sucked into the pump unit via the first filter 2 and the suction passage PA, and is pressurized by the pump unit. The fuel is discharged into the fuel supply path 4 via the discharge path PB and the second filter 3. The fuel in the fuel supply path 4 is regulated to a constant fuel pressure by the pressure regulator R, and the fuel is injected and supplied to the engine through a fuel injection valve mounted on a fuel distribution pipe. On the other hand, when the pressure is regulated by the pressure regulator, the fuel in the fuel chamber 23 of the pressure regulator R is returned to the fuel tank T via the return fuel passage 24.
The return fuel discharged from 4 is ejected into the cup body S via the wire mesh tubular body 10. Here, according to the present invention, the following special effects can be obtained. That is, the return fuel flows from the opening of the return fuel passage 24 to the wire mesh tubular portion 10.
A, and then into the cup S through the wire mesh tubular portion 10A. According to the above, the vapor contained in the return fuel is reduced in diameter and can be effectively eliminated in the cup body S. This means that firstly, when the vapor passes through the wire mesh tubular portion 10A, the diameter of the vapor can be reduced uniformly. That is, when a large vapor passes through the wire mesh tubular portion 10A, the diameter of the vapor is mechanically and uniformly reduced according to the size of the mesh of the wire mesh tubular portion 10A. Further, at the time of passage, the vapor is cooled by the wire mesh tubular portion 10A made of a metal having high thermal conductivity to reduce the diameter. It is due to. In the above, when the return fuel including the vapor is cooled by the wire mesh tubular portion 10A, the temperature of the return fuel is higher than the temperature of the fuel in the fuel tank T including the cup, and the metal tubular body 10 This is because the fuel is disposed in the cup body S where the temperature is low and is kept at a low temperature state. The fact that the temperature of the return fuel is higher than the fuel temperature in the fuel tank T means that the fuel supply path, the pressure regulator R, the fuel distribution pipe, the return fuel passage 2
This is because a fuel supply system such as 4 is disposed near the engine and is easily affected by heat from the engine. Secondly, since the opening of the return fuel passage 24 is directed toward the one-side closing member 10B, the return fuel ejected from the return fuel passage 24 once collides with the one-side closing member 10B, and then collides with the wire mesh tubular portion. It spouts out into the cup body S via 10A. According to the above, since the large vapor is crushed in advance in the wire mesh tubular body 10 by the return fuel colliding with the one-side closing member 10B, it is possible to more effectively eliminate the vapor in the cup body S. it can. Third, when the vapor uniformly reduced in diameter from the wire mesh cylindrical portion 10A touches the fuel in the cup body S having a low fuel temperature, the reduced diameter vapor is further reduced in diameter, and finally the vapor becomes Disappear. According to the above, most of the vapor is eliminated in the cup body S, and the vapor contained in the return fuel is not sucked into the fuel pump again through the first filter 2 and the discharge performance is improved. Deterioration can be suppressed and stable fuel supply can be performed.

According to the above, the return fuel passage 24
The fuel to be ejected is not ejected directly into the cup body S, but is ejected into the cup body S via the wire mesh tubular portion 10A. According to this, the velocity energy of the return fuel is: Since the noise is greatly reduced when passing through the wire mesh cylindrical portion 10A, the noise due to the jet of the return fuel can be greatly reduced. Also, the velocity energy of the return fuel injected into the cup body S can be reduced by colliding with the one-side closing member 10B, so that the velocity energy of the wire mesh tubular portion 10A is reduced, and the noise due to the return fuel jet is further increased. Can be suppressed.

Further, the temperature of the fuel ejected from the return fuel passage 24 into the wire mesh tubular body 10 is controlled by the wire mesh tubular portion 10A.
And the heat absorbed by the one-side closing member 10B is transmitted from the one-side closing member 10B to the cup body S,
Heat is released from the cup body S to the atmosphere. According to the above description, the fuel whose temperature is increased, which is ejected from the return fuel passage 24, can decrease the increased fuel temperature in the wire mesh tubular body 10, and can suppress the increase in the fuel temperature in the fuel tank T, and The evaporation of the low-distilled components in the medium can be suppressed, whereby the amount of fuel vapor discharged from the fuel tank T to the outside can be reduced, and the low-temperature startability of the engine can be prevented from deteriorating.

[0016]

As described above, according to the fuel supply device of the present invention, the wire mesh tubular body has a wire mesh tubular portion having both ends opened, a one-side closing member and another side closing member closing the opening. , The wire mesh tubular body is arranged in the cup body and the one-side closing member is arranged in contact with the cup body,
Further, since the return fuel passage is opened in the wire mesh tubular portion via the other-side closing member and is arranged to face the one-side closing member, the vapor contained in the return fuel is effectively eliminated in the fuel tank. Thus, it is possible to suppress the deterioration of the discharge performance of the fuel pump, obtain the stability of the discharge, and further suppress the generation of noise due to the return fuel. Further, the temperature of the fuel ejected from the return fuel passage is absorbed by the wire mesh tubular portion of the wire mesh tubular portion and the one-side closing member, and this heat is radiated to the atmosphere through the cup body. A rise in temperature can be suppressed, whereby generation of fuel vapor in the fuel tank and discharge to the outside of the fuel tank can be suppressed, and startability of the engine at low temperatures can be improved. Also, a first positioning portion is provided on one side closing member of the wire mesh tubular body, and the first positioning portion is
The wire mesh tubular body was positioned and fixed in the cup body by inserting and arranging it in the second positioning portion provided in the cup body, thereby greatly improving the mountability of the wire mesh tubular body.

[Brief description of the drawings]

FIG. 1 is a vertical sectional view showing a main part of an embodiment of a fuel supply device according to the present invention.

FIG. 2 is an enlarged vertical cross-sectional view of the wire mesh tubular body in FIG.

FIG. 3 is a longitudinal sectional view of a main part of a conventional fuel supply device.

[Explanation of symbols]

 T Fuel tank R Pressure regulator S Cup body P Fuel pump T Fuel tank 10 Wire mesh cylinder 10A Wire mesh cylinder 10B One-side closing member 10C Other-side closing member 10D First positioning portion SA Second positioning portion

Claims (2)

[Claims] 1. A lower opening TA of a fuel tank T is closed by a cup body S having a cup shape with a bottom and a cup body S
The fuel inside the fuel tank is pressurized by the fuel pump P and the fuel whose pressure is regulated to a constant pressure by the pressure regulator R is supplied to the fuel injection valve. On the other hand, the return fuel of the pressure regulator R is supplied to the fuel In the fuel supply device refluxed into the tank T, the wire mesh tubular body 10 includes a wire mesh tubular portion 10A having both ends opened, one side closing member 10B closing the opening, and another side closing member 10C.
And the wire mesh tubular body 10 is formed into a cup body S
And the one-side closing member 10B is placed in the cup body S.
And the return fuel passage 24 is opened in the wire mesh tubular portion 10A via the other-side closing member 10C, and is disposed facing the one-side closing member 10B. apparatus. 2. A wire mesh by providing a first positioning portion 10D on one side closing member 10B of the wire mesh tubular body and inserting the first positioning portion into a second positioning portion SA provided on the cup body S. The fuel supply device according to claim 1, wherein the tubular body (10) is positioned and fixed to the cup body (S).