JPH04105990U - Fuel pump residual pressure holding valve - Google Patents

Abstract

(57) [Summary] [Purpose] The present invention prevents the valve body of a residual pressure holding valve from sinking into the discharge port due to abnormal back pressure generated in the discharge pipe. [Structure] A spring bearing 26 is provided on the upper end side of the valve shaft 24B of the valve body 24, and the spring bearing 26 and the guide cylinder portion 25 of the valve guide 25 are connected to each other.
A coil spring 27 is provided between the coil spring 27 and the spring receiver 26B, and the free end side of the coil spring 27 is connected to the spring receiver 26B of the spring receiver
The configuration is such that the spacer is spaced apart by a minute dimension L in the axial direction. When abnormal back pressure occurs in the discharge pipe 11 and the valve body 24 is strongly pressed in the valve closing direction, and the valve body 24 is displaced in the valve closing direction by a minute dimension L or more, the spring retainer of the spring retainer 26 Part 26B
comes into contact with the free end of the coil spring 27, and the coil spring 27 biases the valve body 24 upwardly via the spring receiver 26 due to its spring force, so that the valve portion 24A of the valve body 24 extends beyond the minute dimension L, Prevents it from being press-fitted into the seat 23.

Description

[Detailed explanation of the idea]

0001

[Industrial application field]

The present invention is provided at the discharge port of a fuel pump, and inside the fuel pipe connected to the discharge port. The present invention relates to a residual pressure holding valve for a fuel pump that maintains a residual pressure of .

0002

[Conventional technology]

FIGS. 2 to 5 show turbine-type fuel pumps as conventional fuel pumps. The following is an example.

0003 In the figure, 1 is provided in a fuel tank (not shown) and has a cylindrical casing body. A turbine-type fuel pump that has a built-in motor part 3 and a pump part 4 inside the fuel pump 2. The pump 1 is provided at the lower end side of the casing body 2 and sucks fuel in the fuel tank. The suction port 2A and the fiber-reinforced wood provided by covering the upper end of the casing body 2 It is provided integrally with the upper cover 2B made of oily material, and the casing is connected from the suction port 2A. A discharge port 2C is provided for discharging the fuel sucked into the main body 2 to the discharge pipe 11 side, which will be described later. A residual pressure holding valve 6, which will be described later, is provided inside the discharge port 2C. And the combustion The fuel pump 1 is powered by a motor section by power supply from a control unit (not shown). 3 is rotated, the fuel in the fuel tank is transferred from the suction port 2A through the filter 5. The fuel is sucked into the pump section 4 and discharged from the discharge port 2C via the residual pressure holding valve 6. It is discharged to the pipe 11 side.

0004 6 indicates a residual pressure holding valve provided in the discharge port 2C of the casing body 2; As shown in FIGS. 3 and 4, the holding valve 6 includes a valve chamber 7 formed in the discharge port 2C, and a valve chamber 7 formed in the discharge port 2C. A valve seat 8 is formed by reducing the diameter of the upstream side (bottom side) of A rubber such as NBR that opens and closes the discharge port 2C by displacing in the axial direction depending on the discharge pressure of the material. The valve body 9 is made of aluminum material and is installed in the valve chamber 7, and the valve body 9 can be slid in the axial direction. The valve guide 10 serves as a valve body support member supported by the valve body.

[0005] Here, the valve body 9 is a hemispherical valve portion 9A that is seated on and off the valve seat 8 as shown in FIG. and a valve integrally formed extending axially inside the valve chamber 7 from the upper surface side of the valve portion 9A. It is composed of a shaft 9B. Then, when the motor section 3 is stopped, the valve body 9 The fuel remaining in the fuel pipe (not shown) connected to the outlet pipe 11 causes the fuel to flow downward. When pressed, the valve portion 9A of the valve body 9 contacts the valve seat 8 within a range where its tip surface can be restored. The valve closes by slightly elastically deforming and seating, reducing the pressure of the fuel in the fuel pipe. (residual pressure) is maintained. Further, the valve guide 10 is located at the discharge port 2C. A large-diameter cylindrical fixed tube portion 10A fixed to the inner circumferential side, and a bottom portion inside the fixed tube portion 10A. The valve body 9 is formed to protrude downward from the center, and the valve shaft 9B of the valve body 9 is inserted therethrough. It is composed of a small diameter cylindrical guide cylinder part 10B etc. that supports the body 9 slidably in the axial direction. It is.

[0006] 11 is a discharge pipe provided above the discharge port 2C, 12 is the discharge pipe 11 and the discharge pipe. A connection hose connecting the port 2C is shown, and both ends of the connection hose are attached to the hose band 1. 3 and 13. Further, the tip 11A of the discharge pipe 11 is provided with fuel. Dust-proof cap that prevents dust from entering from the outside during storage and transportation of pump 1 14 is installed.

[0007] The fuel pump 1 according to the prior art has the above-mentioned configuration, and does not require external supply. The motor section 3 is rotated by electricity, and the motor section 3 drives the motor in the pump section 4. A bottle (not shown) is driven to rotate, whereby the fuel in the fuel tank is transferred to the suction port 2. While being sucked into the casing body 2 from A, the discharge port 2C is drawn from inside the casing body 2. , is discharged into the discharge pipe 11 via the residual pressure holding valve 6, and the fuel is discharged through the discharge pipe 11. It is sent into the pipe.

[0008] Then, the fuel pump 1 stops and the supply of fuel to the fuel injection device is stopped. The pressure inside the housing body 2 is equal to the fuel pump discharge pressure (approximately 0.7 kg/cm² )Than When the pressure also decreases, the residual pressure holding valve 6 crosses the valve portion 9A of the valve body 9 due to the back pressure in the fuel pipe. The valve is closed by being seated on the valve seat 8 while being slightly elastically deformed, and thereby the inside of the fuel pipe is Pressure about 0.7kg/cm²Secure the fuel in the fuel pipe by holding it at a certain level, and then close the engine. Prepare for Jin's restart.

[0009] Now, the fuel pump 1 mentioned above is assembled as a product at the manufacturing stage at the factory. Afterwards, an operation test is performed using test fuel such as kerosene for quality control. stop After the operation test is completed, the test fuel in the casing body 2 and the discharge pipe 11 is After the dust cap 14 is removed and the dust cap 14 is attached to the tip 11A of the discharge pipe 11. , shipped.

0010

[Problem that the idea aims to solve]

By the way, in the conventional technology mentioned above, test fuel is not used for quality control. We are testing the operation of fuel pump 1 using It is difficult to completely remove the fuel, so there is no test inside the casing body 2 or the discharge pipe 11. fuel remains. As a result, the fuel pump 1 is protected from dust as shown in FIG. If the cap 14 is attached and stored in a high temperature place, the residual pressure holding valve 6 and dustproof The test fuel remaining in the discharge pipe 11, which has become a sealed space due to the cap 14, As a result of the volatilization, the pressure inside the discharge pipe 11 rises abnormally, and this pressure rises as indicated by the arrow A in FIG. The valve body 9 may be strongly pressed in the valve closing direction.

[0011] Therefore, in the fuel pump 1 according to the prior art, the residual pressure holding valve 6 is located inside the discharge pipe 11. Pressed by abnormal pressure, the valve portion 9A of the valve body 9 is pressed against the valve seat 8, as shown in FIG. The so-called "sink-in" phenomenon occurs when the tip side is deformed beyond its elastic limit and is press-fitted. occurs, and as a result, the residual pressure holding valve 6 cannot be opened with the discharge pressure when the fuel pump 1 is started. Otherwise, the valve part 9A cannot be restored to its original shape and remains deformed, causing the valve to close when closed. If the sealing performance of the fuel pump 1 is significantly reduced, the reliability of the fuel pump 1 will be significantly reduced. There is a problem.

0012 The present invention was developed in view of the problems of the prior art mentioned above. Even if back pressure due to a rise in internal temperature acts on the residual pressure holding valve, the residual pressure holding valve will not leak. The purpose of the present invention is to provide a fuel pump that can prevent the occurrence of clogging phenomenon. shall be.

[0013]

[Means to solve the problem]

The feature of the configuration adopted by this invention to solve the above-mentioned problems is that the tip of the valve stem of the valve body A spring holder is provided on the end side, and the spring holder is disposed between the spring holder and the valve body support member, and the proximal end is provided with the valve body support member. It is fixed to the body support member, the tip side is a free end, and there is a minute distance from the spring receiver. Alternatively, a spring member that comes into contact with the spring receiver is provided.

[0014]

[Effect]

With the above configuration, if abnormal back pressure occurs on the fuel pipe side and acts on the residual pressure holding valve, this will occur. The valve body of the residual pressure holding valve is pressed in the valve closing direction by the back pressure, and is supported by the valve body support member. It is displaced toward the bottom inside the valve chamber. Then, the valve body has minute dimensions inside the valve chamber. When displaced, the spring receiver comes into contact with the tip side of the spring member, and the valve body moves to a predetermined size. It is possible to prevent downward displacement beyond the normal limit.

[0015]

【Example】

Hereinafter, an embodiment of the present invention will be described based on FIG. 1. In addition, in the example, the above-mentioned The same components as those in the prior art shown in FIGS. 2 to 5 are given the same reference numerals, and their explanations are shall be omitted.

[0016] In the figure, 21 indicates the residual pressure holding valve according to this embodiment, and the residual pressure holding valve 21 is different from the conventional one. A valve chamber 22 formed in the discharge port 2C, almost the same as the residual pressure holding valve 6 described in the section, A valve seat 23 formed on the upstream side of the valve chamber 22, and a valve portion 24A that abuts the valve seat 23. and a valve shaft 24B formed on the upper end side of the valve portion 24A, made of a rubber material such as NBR. Although it is roughly composed of a valve body 24 made of material and a valve guide 25, the front The valve body 24 is provided with a spring receiver 26 (described later), and the valve guide 25 is provided with a coil (described later). A spring 27 is attached.

[0017] Here, the valve guide 25 is a fixed cylindrical portion 25A fixed to the inner peripheral side of the discharge port 2C. is formed to protrude downward from the center of the bottom side of the fixed cylindrical portion 25A, and is formed to protrude downward from the center of the bottom side of the fixed cylinder portion 25A, and is formed on the valve shaft of the valve body 24. 24B and a guide tube portion 25B that slidably supports the guide tube 24B. A cylindrical support that supports and fixes the coil spring 27 is provided on the inner peripheral side of the upper end of the portion 25B. A holding portion 25C is integrally provided.

[0018] That is, 26 indicates a spring receiver provided on the upper end side of the valve shaft 24B of the valve body 24. The spring bearing 26 is connected to a fixed shaft 26A that is press-fitted into the valve shaft 24B and fixed thereto. It is composed of a flat spring receiving part 26B integrally formed on the upper end side. So The spring receiver 26 is connected to the lower surface side of the spring receiver portion 26B and the upper end side of the coil spring 27. For example, a minute dimension L of about 0.05 mm is secured between the fixed shaft 2 6A is attached by being press-fitted into the valve shaft 24B of the valve body 24.

[0019] 27 is a spring receiving part 26B of the spring receiver 26 and a guide cylinder part 25B of the valve guide 25. A coil spring is shown as a spring member disposed between the coil spring and the coil spring. The lower end side of the valve guide 27 is fitted onto the supporting portion 25C of the valve guide 25 and fixed to the valve guide 25. The upper end side becomes a free end, and the minute dimension is They are separated by a distance of L.

[0020] The coil spring 27 is connected to the valve body 24 when the fuel pump 1 stops operating. is pressed in the valve-closing direction and is displaced by a minute dimension L, the upper end of the 26, and thereby the valve portion 24A of the valve body 24 contacts the valve seat 23. Seats while being slightly deformed within the restorable range and seals between the valve portion 24A and the valve seat 23. At the same time, abnormal back pressure is generated on the fuel pipe side due to high temperature etc., causing the valve body 24 to close. If the valve is displaced by a minute dimension L or more, the upward spring force in the axial direction The valve body 24 is biased in the valve opening direction via the spring receiver 26, and the valve body 24 is This prevents it from moving downward.

[0021] The fuel pump according to this embodiment has the above-mentioned configuration, and its basic operation is as follows. There is no particular difference from the conventional technology.

[0022] However, in this embodiment, a spring receiver 26 is provided on the upper end side of the valve shaft 24B of the valve body 24, A coil spring 27 is installed between the spring receiver 26 and the guide cylinder portion 25B of the valve guide 25. The coil spring 27 has its proximal end fixed to the support portion 25C of the valve guide 25. with the tip side being a free end and between it and the lower end surface of the spring receiver part 26B of the spring receiver 26. , because it is configured to be separated by the minute dimension L necessary to obtain sealing performance when the valve is closed. , abnormal back pressure occurs in the discharge pipe 11, and the valve body 24 is strongly pressed in the valve closing direction, causing the valve body to close. 24 is displaced by the minute dimension L or more, the spring receiving part 26B of the spring receiving part 26 becomes a coil spring. abuts against the free end of the spring 27, causing the coil spring 27 to exert its spring force. The valve body 24 is biased upward via the spring receiver 26, and the valve portion 24A of the valve body 24 is opened as a valve. It is possible to effectively prevent the seat 23 from being deformed and press-fitted. As a result, the valve body 24 The residual pressure holding valve 21 is prevented from being abnormally deformed because the valve portion 24A cannot return to its original shape. This effectively prevents malfunctions such as valve opening and closing failures, and improves the performance of the fuel pump. Reliability and lifespan can be significantly improved.

[0023] In the above embodiment, the spring bearing 26 is press-fitted into the valve shaft 24B of the valve body 24 and fixed. However, the present invention is not limited to this, and the spring receiver 26 can be fixed by screwing, adhesive, etc. Alternatively, a spring bearing may be attached to the tip of the valve shaft 24B. It may be integrally formed on the side.

[0024] Further, in the above embodiment, the coil spring 27 is used as the spring member. However, the present invention is not limited to this, and can be applied to other spring parts such as disc springs and rubber springs. Materials may also be used.

[0025] Furthermore, in the embodiment, the spring receiving part 26B of the spring receiving part 26 and the coil spring 2 The above description assumes that a minute dimension of approximately 0.05 mm is secured between the free end of 7 and the free end of 7. However, the present invention is not limited to this, and for example, the discharge pressure of the fuel pump is 2.5 kg/cm2. In the case of Just adjust L appropriately. In addition, the valve body is formed from a hard material such as a metal material, and the valve part If sealing performance can be obtained simply by sitting on the valve seat, the minute dimension L can be set to substantially 0. As shown in FIG. You may.

[0026] On the other hand, in the above embodiment, explanation was given using a turbine type fuel pump as an example. The invention is not limited to this, for example, there are various types such as roller vane type and trochoid type fuel pumps. It can also be applied to other types of fuel pumps.

[0027]

[Effect of the idea]

As detailed above, according to the present invention, a spring bearing is provided on the tip end side of the valve shaft of the valve body. The proximal end is fixed to the valve body support member, and the distal end is disposed between the valve body support member and the valve body support member. A spring whose end side is a free end and is spaced by a minute distance from the spring receiver or comes into contact with the spring receiver. Since the structure is equipped with spring members, even if abnormal back pressure occurs on the fuel piping side, residual pressure will be eliminated. The valve body of the holding valve should be larger than the required size in the valve closing direction to obtain sealing performance inside the discharge port when the valve is closed. It can effectively prevent displacement from occurring, and ensure that the phenomenon of sinking into the residual pressure holding valve occurs. This effectively prevents malfunctions such as opening and closing failures of residual pressure holding valves. The reliability of the fuel pump can be improved.

[Brief explanation of drawings]

FIG. 1 is an enlarged vertical sectional view of a residual pressure holding valve according to an embodiment of the present invention.

FIG. 2 is a front view showing a storage state of a fuel pump according to the prior art.

FIG. 3 is a partially cutaway front view showing an enlarged view of the fuel pump.

FIG. 4 is an enlarged vertical sectional view of a main part of the residual pressure holding valve in FIG. 3;

FIG. 5 is a vertical cross-sectional view of a main part similar to FIG. 4, showing a state in which the residual pressure holding valve has sunk into the discharge port.

[Explanation of symbols]

1 Fuel pump 2C discharge port 21 Residual pressure holding valve 22 Valve chamber 23 Valve seat 24 Valve body 24A Valve part 24B Valve stem 25 Valve guide (valve body support member) 26 Spring holder 27 Coil spring (spring member)

Claims (1)

[Scope of utility model registration request] 1. A valve chamber formed in a discharge port of a fuel pump, a valve seat provided at the bottom of the valve chamber, a valve section provided in the valve chamber and seated on and off the valve seat, and the valve. A fuel comprising: a valve body comprising a valve shaft extending axially into the valve chamber from the valve body; and a valve body support member provided within the valve chamber and slidably supporting the valve shaft of the valve body in the axial direction. In the residual pressure holding valve of the pump, a spring bearing is provided on the distal end side of the valve shaft of the valve body, the spring bearing is disposed between the spring bearing and the valve body support member, and the proximal end side is fixed to the valve body support member. 1. A residual pressure holding valve for a fuel pump, characterized in that a spring member is provided, the tip side of which is a free end, and is spaced apart from or in contact with the spring receiver by a minute dimension.