JP2001099030A - Fuel supply device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve discharging performance while suppressing re-intake of vapor contained in returned fuel into a fuel pump, and suppress generation of noises accompanied with injection of returned fuel into a fuel tank. SOLUTION: Fuel in a fuel tank is boosted by a fuel pump and adjusted in its pressure to a constant value by means of a pressure regulator. The thus obtained fuel is supplied to a fuel injection valve. The returned fuel in the pressure regulator is circulated to the fuel tank through a return fuel passage. A metal mesh cylindrical body is arranged in the fuel tank, while the return fuel passage is opened into the metal mesh cylindrical body. The returned fuel is circulated into the fuel tank through the metal mesh cylindrical body.

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 a pressure regulator (not shown). In the pressure regulator, the housing is divided into a spring chamber and a fuel chamber by a diaphragm, and the fuel chamber has a return fuel passage R connected to the fuel supply passage 4 and the fuel tank T described above.
Opens. A valve that opens and closes a return fuel passage that opens to the fuel chamber is integrally attached to the diaphragm. Here, when fuel pressurized by the fuel pump P is supplied from the fuel supply passage 4 into the fuel chamber by the fuel pump P, the diaphragm is displaced toward the spring chamber against the spring force of the spring contracted in the spring chamber, and the valve is moved. Opens the return fuel passage so that the fuel pressure supplied to the fuel distribution pipe can be regulated to a predetermined constant fuel pressure. According to the valve opening the return fuel passage at the time of the pressure regulation, a part of the pressurized fuel supplied from the fuel supply passage 4 into the fuel chamber includes the cup body S via the return fuel passage R. It squirts well into the fuel tank T.

[0003]

According to the flow of fuel in such a fuel supply device, a large amount of vapor is contained and discharged in the fuel flowing back from the return fuel passage R into the fuel tank T. The generation of the vapor means that the fuel pressure is largely 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. by. Here, when the return fuel passage R is directly opened into the fuel tank T and the return fuel is jetted into the fuel tank T, the large vapor contained in the return fuel does not disappear and remains in the fuel tank. This vapor is likely to be sucked into the pump portion of the fuel pump P again through the first filter 2, which may deteriorate the discharge performance of the pump and stabilize it. Fuel supply cannot be performed. Furthermore, when a large vapor is sucked into the fuel tank T, noise is generated, which is not preferable.

On the other hand, in order to solve the above-mentioned problem, it is considered that a metallic sponge-like member 5 which is randomly bent toward the opening of the return fuel passage R is arranged. According to this, although a deterrent effect on the vapor entering the first filter 2 is recognized, the following problem still remains. (1) Since the return fuel passage R still directly opens into the fuel tank T, generation of noise in the fuel tank T is not suppressed. (2) The sponge-like member 5 needs to be arranged over almost 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. 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 increases the pressure of a fuel in a fuel tank by a fuel pump and adjusts the pressure of the fuel to a constant pressure by a pressure regulator. In a fuel supply device for supplying fuel to a fuel injection valve and returning return fuel of a pressure regulator to a fuel tank through a return fuel passage, a wire mesh tubular body is arranged in the fuel tank and the wire mesh tubular body is provided. Open the return fuel passage inside the
The first feature is that the return fuel is returned to the fuel tank through the wire mesh tubular portion of the wire mesh tubular body.

Further, according to the present invention, in addition to the first aspect, the wire mesh tubular body comprises a wire mesh tubular portion having both ends opened, and a plate portion closing the opening, and a return fuel passage is formed. A second feature is that the metal mesh tubular body is opened toward the inner plate portion.

[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, according to the second feature, the return fuel once collides with the plate portion in the wire mesh tubular body and then passes through the wire mesh tubular portion and is ejected into the fuel tank. Therefore, the velocity energy of the return fuel can be further reduced by the collision with the plate portion, the vapor heading toward the wire mesh tubular portion can be reduced in advance, and the vapor can be further reduced by passing through the wire mesh tubular portion. Can disappear.

[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. The return fuel passage R is connected to the inside of the fuel tank T via the wire mesh tubular body 10. FIG.
Will be described in detail with reference to FIG. Wire mesh tubular body 1
Numeral 0 includes a cylindrical wire mesh tubular portion 10A having both ends opened, and plates 10B and 10C closing both openings. The wire mesh tubular portion 10A is made of a metal material (for example, iron, stainless steel, or the like) having a higher thermal conductivity than a synthetic resin material, filter paper, or the like, and is woven in a mesh shape, and the size of the mesh is appropriately selected. . The wire mesh tubular body is arranged in the cup body S, and the return fuel passage R is opened and arranged in the wire mesh tubular portion 10A via the lower plate 10B.

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 a pressure regulator (not shown), and this fuel is injected and supplied to the engine via 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 of the pressure regulator is recirculated into the fuel tank T via the return fuel passage R.
Is discharged into the cup body S through 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 R into the wire mesh tubular portion 10A, and then passes through the wire mesh tubular portion 10A and is ejected 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. 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. And at the time of its 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. Further, 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 system such as the fuel supply path, the pressure regulator, the fuel distribution pipe, the return fuel path R, etc. is arranged near the engine, Because it is easily affected by heat from the engine. Second, the wire mesh tubular portion 1
When the vapor uniformly reduced in diameter from 0 A 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 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.

Further, according to the above, the fuel injected from the return fuel passage R is not injected straight into the cup body S, but is discharged into the cup body S via the wire mesh tubular body 10. According to this, the velocity energy of the return fuel is greatly weakened when passing through the wire mesh tubular portion 10A, so that the noise due to the jet of the return fuel can be greatly reduced.

Further, as shown in detail in FIG. 2, when the opening of the return fuel passage R is directed toward the upper plate 10C, the return fuel ejected from the return fuel passage R once collides with the plate 10C. Later, it is ejected into the cup body S via the wire mesh tubular portion 10A. According to the above, a large vapor is crushed in advance in the wire mesh tubular body 10 by the return fuel colliding with the plate 10C, so that the vapor in the cup body S can be eliminated more effectively. Further, since the velocity energy of the return fuel can be reduced by the collision with the plate 10C, the generation of noise due to the return fuel jet can be further suppressed in combination with the reduction of the velocity energy by the wire mesh tubular portion 10A.

[0013]

As described above, according to the fuel supply apparatus of the present invention, the wire mesh tubular body is disposed in the fuel tank, and the return fuel passage is opened inside the wire mesh tubular body, so that the return fuel is supplied. Since the fuel is returned into the fuel tank T through the wire mesh tubular portion of the wire mesh tubular body, the vapor contained in the return fuel can be effectively eliminated in the fuel tank, and the deterioration of the discharge performance of the fuel pump can be reduced. In addition to suppressing the noise, it is possible to obtain the stability of the discharge and further suppress the generation of noise due to the return fuel. Also, since the wire mesh tubular body includes a wire mesh tubular portion having both ends opened and a plate portion closing the opening, and the return fuel passage is opened toward the inner plate portion of the wire mesh tubular body. Thus, the vapor can be more effectively eliminated in the fuel tank, and the generation of noise can be further suppressed.

[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 longitudinal sectional view of a wire mesh cylinder state 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 return fuel passage P fuel pump 10 wire mesh tube 10A wire mesh tube 10C plate

Claims (2)

[Claims] 1. The fuel in a fuel tank is pressurized by a fuel pump and supplied to a fuel injection valve at a constant pressure by a pressure regulator, and the return fuel of the pressure regulator is supplied to a return fuel passage. In the fuel supply device which is recirculated into the fuel tank through the fuel tank T, the wire mesh tubular body 10 is arranged in the fuel tank T, and the return fuel passage R is opened inside the wire mesh tubular body 10 to return the return fuel to the wire mesh. Wire mesh tubular portion 10A of tubular body 10
A fuel supply device, wherein the fuel is returned into the fuel tank T through the fuel supply device. 2. The wire mesh tubular body includes a wire mesh tubular portion 10A having both ends opened, and a plate portion 10 closing the opening.
2. The fuel supply device according to claim 1, wherein the fuel supply device comprises B and 10C, and the return fuel passage R is opened toward the inner plate portion 10C of the wire mesh tubular body 10.