JP2001140721A - Fuel supply device - Google Patents

Abstract

(57) [Summary] [Purpose] To prevent the vapor contained in the return fuel from being sucked into the fuel pump again to improve the discharge performance, and to reduce the noise generated by the return fuel being injected into the fuel tank. Suppress and further suppress the temperature rise in the fuel tank. [Structure] The fuel in a fuel tank is pressurized by a fuel pump and supplied to a fuel injection valve while the pressure is regulated to a constant pressure by a pressure regulator. On the other hand, return fuel of the pressure regulator is supplied via a return fuel passage. Reflux into the fuel tank. The wire mesh tubular body 10 is formed by a wire mesh tubular portion 10C having both ends opened with an upper opening 10A and a lower opening 10B, and an upper closing member 10D closing the upper opening 10A. Wire mesh tubular body 1
0 in the cup body S and the lower opening 10B.
Is fitted to the positioning tubular protrusion SA provided on the cup body S and closed. Return fuel passage 24 to upper blocking member 1
It is opened in the wire mesh tubular portion 10C via OD, and is arranged facing the protruding end surface SC of the positioning tubular protrusion SA.

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 pressurized by the fuel pump P is supplied from the fuel supply passage 4 into the fuel chamber 23, the diaphragm 21 is moved toward the spring 22 chamber against the spring force of the spring 26 contracted in the spring 22 chamber. 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 in the fuel that flows back into the fuel tank T from the return fuel passage 24 and is discharged. or,
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 discharge performance of the pump is reduced. May deteriorate, 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. I can not get the nature. There is a problem that.

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 problems, 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 closes a lower opening of a fuel tank with a cup body having a cup shape with a bottom and removes fuel in the cup body. In the fuel supply device, the fuel is pumped up by the fuel pump and the fuel regulated to a constant pressure by the pressure regulator is supplied to the fuel injection valve, while the return fuel of the pressure regulator is returned to the fuel tank through the return fuel passage. , A wire mesh tubular body, an upper opening, a wire mesh tubular portion having both ends opened with a lower opening,
Formed by an upper closing member that closes the upper opening,
The wire mesh tubular body is arranged in the cup body, and the lower opening is closed by being fitted to a positioning tubular protrusion provided in the cup body, and the return fuel passage is further closed via an upper closing member. The positioning cylindrical projection is open to the inside of the projection and is opposed to the projection end face of the positioning cylindrical projection.

[0007]

According to the present invention, the return fuel ejected from the return fuel passage is returned to the fuel tank through the wire mesh tubular body. The vapor contained in the return fuel is
When passing through the wire mesh tubular portion of the wire mesh tubular body, it is miniaturized, cooled by the wire mesh tubular portion, and 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. Also, the temperature of the return fuel ejected from the return fuel passage is absorbed by contacting the wire mesh cylindrical portion and the protruding end surface of the positioning cylindrical protrusion of the cup body, and the heat is absorbed into the atmosphere through the cup body. Heat is dissipated. Further, the wire mesh tubular body is positioned and fixed by fitting the lower opening to the positioning tubular protrusion of the cup body, so that the mountability of the wire mesh tubular body can be improved.

[0008]

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 is formed by a wire mesh tubular portion 10C having both ends opened with an upper opening 10A and a lower opening 10B, and an upper closing member 10D closing the upper opening 10A. The upper opening 10A is a disk or cylindrical upper closing member 10
D, and the fuel return passage 2
4 is provided with an opening 10E into which the base 4 can be inserted. The lower opening 1
In order to maintain the strength of the opening at 0B, the ring member 10F
May be arranged. The metal net tubular portion 10C is made of a metal material (for example, iron, aluminum, an aluminum alloy, stainless steel, or the like) having a higher thermal conductivity than a synthetic resin material, filter paper, or the like.
Is woven in a mesh shape, and the size of the mesh is appropriately selected.

The wire mesh tubular body 10 is disposed in the cup body S. At this time, the lower opening 10B of the wire mesh tubular body 10 is fitted into the positioning tubular protrusion SA provided on the cup body S. Be placed. The positioning cylindrical protrusion SA is formed as a cylindrical protrusion protruding upward from the bottom SB of the cup body S. Accordingly, the lower opening 10B of the wire mesh tubular portion 10C is fitted and arranged in the positioning tubular protrusion SA of the cup body S, whereby the wire mesh tubular body 10 can be fixedly arranged at a predetermined position in the cup body S.

On the other hand, the return fuel passage 24 is inserted and arranged in the opening 10E of the upper closing member 10D.
It opens into the wire netting cylindrical portion 10A via D and opens toward the protruding end surface SC of the positioning cylindrical protrusion SA of the cup body S.

What should be particularly noted here is that when the wire mesh tubular body 10 is arranged in the cup body S, the wire mesh tubular body 1
That is, the lower opening 10B of OC is closed by the positioning projection SA, and the return fuel passage 24 is opened facing the protruding end surface SC of the positioning cylindrical projection SA.

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 is ejected from the opening of the return fuel passage 24 into the wire mesh tubular portion 10A, and then passes through the wire mesh tubular portion 10C into the cup body S. 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. First, the diameter of the vapor can be reduced uniformly when the vapor passes through the wire mesh tubular portion 10C. That is, when a large vapor passes through the wire mesh tubular portion 10C, the vapor is mechanically and uniformly reduced in diameter according to the size of the mesh of the wire mesh tubular portion 10C. And at the time of its passage,
The vapor is cooled by the wire mesh tubular portion 10C 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 10C, the temperature of the return fuel is higher than the temperature of the fuel in the fuel tank T including the cup body, and the wire mesh tubular material 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. Further, the fact that the temperature of the return fuel is higher than the temperature of the fuel in the fuel tank T means that the fuel supply system such as the fuel supply passage, the pressure regulator R, the fuel distribution pipe, the return fuel passage 24, etc. is arranged near the engine. , Because it is susceptible to heat from the engine. Second, since the opening of the return fuel passage 24 is slid toward the protruding end surface SC of the positioning cylindrical protrusion SA of the cup body S, the return fuel ejected from the return fuel passage 24 is once protruded. After colliding with the SC, the fuel is jetted into the cup body S via the wire mesh tubular portion 10C. According to the above description, the return fuel collides with the protruding end surface SC, so that a large vapor is previously formed in the wire mesh tubular body 10. Since the powder is pulverized, the vapor in the cup body S can be eliminated more effectively. Thirdly, the vapor uniformly reduced in diameter from the wire mesh tubular portion 10C is used as a cup body S having a low fuel temperature.
When the fuel inside is touched, the reduced diameter vapor is further reduced, and finally the vapor disappears. 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 through the wire mesh tubular portion 10C. 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. The velocity energy of the return fuel injected into the cup S is determined by the positioning cylindrical protrusion SA.
Can be reduced by colliding with the protruding end surface SC, so that the generation of noise due to the return fuel jet can be further suppressed in combination with the reduction of the speed energy by the wire mesh tubular portion 10C.

Further, the temperature of the fuel injected from the return fuel passage 24 into the wire mesh tubular body 10 is lower than the temperature of the return fuel. The wire mesh tubular portion 10C and the positioning tubular protrusion SA of the cup body S are located at a lower temperature. Is directly absorbed by the protruding end surface SC, and the absorbed heat is radiated 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 effectively reduce the increased fuel temperature by the wire mesh tubular portion 10C of the wire mesh tubular body 10 and the cup body S. The fuel temperature in the T can be prevented from rising, the low-distilled components in the fuel can be prevented from evaporating, and the amount of fuel vapor discharged from the fuel tank T to the outside can be reduced. Can be prevented.

The upper opening 10A of the wire mesh cylindrical body 10 disposed in the cup S is closed by an upper closing member 10D, and the lower opening 10B is closed by a positioning cylindrical protrusion SA of the cup S. Therefore, a special member for closing the lower opening 10B is not required, which is effective for reducing the manufacturing cost of the device itself. Further, when the wire mesh tubular body 10 is mounted on the cup body S, the lower opening 10B is formed by positioning the cylindrical tubular projection SA of the cup body S.
By fitting the wire mesh tubular body 10, the wire mesh tubular body 10 can be positioned and fixedly arranged, so that the mountability can be greatly improved.

[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 with an upper opening and a lower opening, and an upper portion closing the upper opening. A closure member is formed, and the wire mesh tubular body is disposed in the cup body, and the lower opening is closed by fittingly disposed in a positioning tubular protrusion provided in the cup body, and further, the return fuel passage is located on the upper side. Opening into the wire mesh tubular portion via the closing member and facing the protruding end surface of the positioning tubular protrusion, the vapor contained in the return fuel can be effectively eliminated in the fuel tank because the fuel contained in the return fuel can be effectively eliminated. It is possible to suppress the deterioration of the discharge performance of the pump, obtain the stability of the discharge, and further suppress the generation of noise due to the return fuel. Also, the temperature of the fuel ejected from the return fuel passage is absorbed by the wire mesh tubular portion of the wire mesh tubular body and the positioning protrusion of the cup body, and this heat is radiated to the atmosphere through the cup body. It is possible to suppress a rise in fuel temperature inside the fuel tank, thereby suppressing the generation of fuel vapor in the fuel tank and discharging the fuel to the outside of the fuel tank, and further improve the startability of the engine at low temperatures.
Furthermore, the lower opening of the wire mesh tubular body is closed by being fitted to the positioning tubular protrusion of the cup body and is fixedly positioned on the cup body, thereby reducing the number of parts and improving the mounting property. This is effective in reducing the manufacturing cost of the device itself.

[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 SA Positioning cylindrical projection SC Projecting end face P Fuel pump 10 Wire mesh tubular body 10A Upper opening 10B Lower opening 10C Wire mesh tubular part 10D Upper closing member 24 Return fuel passage

Claims (1)

[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 10C having both ends opened with an upper opening 10A and a lower opening 10B, and an upper opening 10A.
By closing the wire mesh tubular body in the cup body S and fitting the lower opening 10B to the positioning tubular protrusion SA provided in the cup body S. The return fuel passage 24 is closed via the upper closing member 10D.
A fuel supply device, wherein the fuel supply device opens in C and faces the protruding end surface SC of the positioning cylindrical protrusion SA.