JPH08277758A - Fuel filter - Google Patents

Abstract

PURPOSE: To reduce labor for ensuring the sealing property by reducing piping paths and connection paths. CONSTITUTION: A filter 30 is housed in a fuel filter housing 20, and also it is interposed between a fuel suction port 23 and a fuel discharge port 24, and a check valve 27 is interposed between the fuel discharge port 24 and a fuel pipe 51, being connected to the the injector, while a fuel discharge port 25 is connected to the inside of a fuel tank 50. Hereby, the piping path between the fuel tank 50 and the injector can be made one, whereby the connection paths are reduced and the labor for ensuring sealing property can be reduced.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION This invention relates to fuel filters.

[0002]

2. Description of the Related Art Conventionally, as this type of fuel filter, the one shown in Japanese Utility Model Laid-Open No. 61-53564 has been known. In FIG. 5, the fuel filter housing 1 contains a cylindrical filter medium 2 having an inner peripheral surface on the clean side, and between the fuel suction port 3 and the fuel discharge port 4 formed in the fuel filter housing 1. Intervened. In FIG. 6, the fuel suction port 3 of the fuel filter 5 is connected to the discharge port of the fuel pump 7 in the fuel tank 6, and the fuel discharge port 4 is connected to the injector 8 and the pressure regulator 9 of the engine. The pressure regulator 9 bypasses the fuel to the fuel tank 6 when the discharge pressure to the injector 8 becomes equal to or higher than a predetermined pressure. The maximum discharge amount of the injector 8 per unit time is smaller than the maximum discharge amount of the fuel pump 7.

The fuel discharged from the fuel pump 7 passes through the fuel filter 5, is filtered to remove dust and the like, and is supplied to the injector 8 and the pressure regulator 9. Part of the fuel is supplied to the combustion chamber of the engine via the injector 8. However, the rest is sent back to the fuel tank 6 via the pressure regulator 9. That is, a forward path and a return path are formed in the pipe path between the fuel tank 6 and the injector 8.

[0004]

In the above-described conventional fuel filter, a loop-shaped two pipes, an outward route and a return route, are prepared as a pipe passage between the fuel tank 6 and the injector 8, and A pressure regulator, which is a separate component, has to be arranged on the way, and there is a problem in that the number of connection paths increases and the labor for securing the sealing property increases.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a fuel filter capable of reducing the labor for securing the sealing property by reducing the number of piping and connecting paths.

[0006]

In order to achieve the above object, the invention according to claim 1 accommodates a filter medium in a fuel filter housing to partition the inside thereof, and forms a fuel suction port on the dirty side of the filter medium. At the same time, a fuel discharge port is formed on the clean side, and a pressure regulator for communicating the inside and the outside when the internal pressure of the fuel filter housing becomes equal to or higher than a predetermined pressure is integrally formed.

The invention according to claim 2 is the fuel filter according to claim 1, wherein the fuel filter is housed in the fuel tank. further,
The invention according to claim 3 is the fuel filter according to claim 1 or claim 2, wherein the pressure regulator is open to the clean side in the fuel filter housing.

[0008]

In the invention according to claim 1 configured as described above, the fuel is supplied from the fuel suction port to the dirty side of the fuel filter housing partitioned by the filter medium, and the fuel passing through the filter medium is cleaned. At the time of discharging from the fuel discharge port formed on the side, the pressure regulator keeps the discharge pressure of the fuel filter housing constant because the pressure regulator communicates the inside and outside when the internal pressure of the fuel filter housing exceeds a predetermined pressure. From the engine side to the engine side.

Further, in the invention according to claim 2 configured as described above, the fuel filter is housed in the fuel tank, and excess fuel discharged from the pressure regulator is directly discharged into the fuel tank. To be done. further,
In the invention according to claim 3 configured as described above,
Excess fuel discharged by the pressure regulator is discharged from the clean side, so the fuel that passes through the pressure regulator becomes clean, and there is a route for filtering the fuel in the fuel tank and discharging it again into the fuel tank. It is formed.

[0010]

As described above, according to the present invention, the discharge pressure is made constant in the fuel filter. Therefore, it is possible to reduce the number of connecting passages to a seal by reducing the number of connecting passages from the fuel filter to the engine side. It is possible to provide a fuel filter capable of reducing the time and effort required to secure the property. According to the invention of claim 2,
Since the fuel filter is housed in the fuel tank, it is possible to reduce the sealing performance for the fuel filter. Here, when perfect sealing performance against fuel is required, it takes a lot of man-hours including the check in the manufacturing process. However, since the fuel filter is housed in the fuel tank, the complete sealing performance required for the conventional fuel filter becomes unnecessary, and the manufacturing process can be greatly omitted.

Further, according to the invention of claim 3, the fuel in the fuel tank can be always filtered. Also,
The fuel that has passed through the pressure regulator is debris-free, so that the valve portion of the pressure regulator can be prevented from being damaged by the dust.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. 1 is a sectional view showing a fuel supply system to which a fuel filter according to an embodiment of the present invention is applied, FIG. 2 is a sectional view showing a state in which a pressure regulator is closed, and FIG. 3 is an open state. The state which is valved is shown by sectional drawing.

Referring to FIG. 1, the fuel filter 10 includes a fuel filter housing 20 having a generally cup-shaped lower case 21 and an inverted dish-shaped upper case 22 which is fixed by welding to cover an upper opening of the lower case 21. And a filter medium 30 is housed in the fuel filter housing 20. The filter medium 30 is formed into a substantially cylindrical shape, and has a side wall on which a filter medium is disposed, and an upper surface is opened and a bottom surface is closed by a lid. The upper surface of the filter medium 30 is in close contact with the ceiling surface of the upper case 22, and between the outer peripheral surface of the filter medium 30 and the inner peripheral surface of the lower case 21, and between the inner peripheral surface of the filter medium 30 and the ceiling surface of the upper case 22. Separated spaces are secured in each.

The space in the fuel filter housing 20 facing the outer peripheral surface of the filter medium 30 is a dirty side, and a tubular fuel suction port 23 projecting downward is formed at the bottom corner of the lower case 21. . On the other hand, the space facing the inner peripheral surface of the filter medium 30 in the fuel filter housing 20 is a clean side, and forms a tubular fuel discharge port 24 that projects from the upper case 22 toward the inside of the filter medium 30 to communicate the inside and the outside. At the same time, a through hole 25a is formed on the bottom surface of the lower case 21, and a pipe 25b is penetrated through the lid body on the bottom surface of the filter medium 30 to be connected to the through hole 25a to form a fuel discharge port 25. In this way, the inside of the filter medium 30, which is the clean side, communicates with the outside through the fuel discharge port 24 and the fuel discharge port 25.

A check valve 27 is formed at the outlet of the fuel discharge port 24 on the upper surface of the upper case 22. This check valve 27 is used for the upper case 2
2, the peripheral edge of the fuel discharge port 24 is extended upward in a cylindrical shape, and the upper end thereof is covered with a lid 26 which is a donut-shaped disc.
The valve plug 28 is abutted by a coil spring 29 toward the. With this configuration, the fuel discharge port 24
The fuel flows in the direction from the check valve 27 to the check valve 27, but does not flow in the opposite direction.
In addition, on the outer peripheral surface of the check valve 27, an annular groove 2 is formed.
7a is formed, and an O-ring 27b is attached to the groove 27a. As a result, it is possible to easily connect the check valve 27 while ensuring the sealing property only by inserting the check valve 27 into the cylindrical body.

In this embodiment, the fuel filter housing 20 and the filter medium 30 are generally cylindrical, but
If the inside of the closed case is divided by a filter medium and the fuel suction port 23 is opened in one space and the fuel discharge port 24 is opened in the other space and the filter medium is interposed therebetween,
Other shapes are possible. Also, check valve 2
The fuel filter 1 is not always necessary for the fuel filter 1.
Since the outlet of 0 is also an inlet to a single pipeline as it is, preventing backflow at that portion makes it difficult for air to enter the pipeline.

A pressure regulator 40 is integrally formed on the bottom surface of the lower case 21, and the through hole 25 is formed.
a communicates with the pressure regulator 40. The pressure regulator 40 has a casing 41 that projects downward from the lower surface of the lower case 21, and forms a single discharge path 42 that communicates from the upper portion to the lower portion of the casing 41. The upper end of the discharge path 42 communicates with the through hole 25a, and has an opening 43 that opens laterally at an intermediate portion, and the inside of the opening 43 is located at the center to the lower part of the discharge path 42. Small hole 4 communicating
4 is formed. Also, the cover 43 covers the opening 43, and the valve seat unit 47 is pressed toward the small hole 44 through the coil spring 46 in the cover 45 to seal the opening 43. Therefore, when the valve seat unit 47 divides the discharge path 42 and the pressure on the upper side is smaller than a predetermined pressure, the valve seat unit 47 is formed in the small hole 44 by the coil spring 46 as shown in FIG. Press the discharge route 4
2 is closed, and when the pressure on the upper side becomes higher than a predetermined pressure, the valve seat unit 47 is separated from the small hole 44 and the discharge path 42 is opened against the coil spring 46 as shown in FIG. . Thereby, the pressure on the upper side can be kept constant.

The pressure regulator 40 in this embodiment is merely an example, and another structure may be used as long as the inside and outside communicate with each other when the internal pressure of the fuel filter housing 20 exceeds a predetermined pressure. Also in that shape, it may be in another shape that is integrally formed. Further, the fuel discharge port 25 communicating with the discharge path 42 does not necessarily have to be opened to the clean side, but by opening to the clean side, a circulation path for fuel to pass through the filter medium 30 is formed between the fuel tank and the fuel tank. , Can clean the fuel. Further, the fuel from which dust has been removed passes between the valve seat unit 47 and the small hole 44, so that the valve seat unit 47 can be prevented from being damaged and the small hole 44 can be prevented from being clogged. it can.

The fuel filter 10 has a fuel tank 50.
It is housed inside. As shown in FIGS. 1 and 4, a fuel pipe 51 communicating with an injector 60 on the engine side is connected to a ceiling surface of the fuel tank 50, and a lower end of the fuel pipe 51 is a cylinder into which the check valve 27 can be inserted. It is formed into a shape. Therefore, the fuel filter 10
By inserting the check valve 27 protruding from the upper surface into the tubular portion from below, the O-ring 27b on the outer peripheral surface closely seals the inner peripheral surface of the tubular portion,
The fuel discharge port 24 and the fuel pipe 51 communicate with each other through the hole of the lid 26 of the check valve 27.

A fuel pump 7 is provided below the fuel filter 10.
0 is arranged, the discharge port 71 of the fuel pump 70 is connected to the fuel suction port 23, and the suction port 72 of the fuel pump 70 is connected.
Is opened in the fuel tank 50 through a strainer 73. Further, a discharge conduit 48 is connected to the lower end of the discharge passage 42 of the pressure regulator 40 integrally formed in the lower portion of the fuel filter 10 and opened in the fuel tank 50. Next, the operation of this embodiment having the above configuration will be described. The fuel pump 70 sucks fuel in the fuel tank 50 and supplies the fuel into the fuel filter housing 20 through the fuel suction port 23 of the fuel filter 10. Initially, as shown in FIG. 2, the pressure regulator 40 closes the valve seat unit 47 by abutting the valve seat unit 47 toward the small hole 44. Then, when the internal pressure tends to increase as the fuel is supplied into the fuel filter housing 20 and becomes higher than the predetermined discharge pressure, that is, the pressure determined by the coil spring 46 of the pressure regulator 40, FIG. As shown, the valve seat unit 47 is separated from the small hole 44 against the coil spring 46, and a gap is formed to open the valve. Then, the fuel sucked from the fuel suction port 23 into the fuel filter housing 20 passes through the filter medium 30, and the fuel discharge port 25
The fuel is discharged from the fuel filter housing 20 through the discharge passage 42 of the pressure regulator 40 and discharged into the fuel tank 50. Therefore, the discharge pressure, which is the internal pressure of the fuel filter housing 20, becomes constant. Since the discharge amount of the fuel pump 70 is larger than the amount of fuel injected by the injector 60, the fuel is constantly circulated through the filter medium 30 into the fuel tank 50, and the fuel dust may be removed. it can. On the other hand, when the fuel pump 70 sucks and discharges the fuel, abrasion powder worn from the rotating portion and the like is discharged together with the fuel. The abrasion powder is filtered by the filter medium 30 and the fuel from which dust has been removed is supplied to the pressure regulator 40, so that the valve seat unit 47 is not damaged and the small hole 44 is not clogged.

On the other hand, when the injector 60 is opened, the fuel inside the fuel filter housing 20 passes through the filter medium 30 and is supplied from the fuel discharge port 24 through the check valve 27 to the injector 60 through the fuel pipe 51. Normally,
When the injector 60 is opened, a required amount of fuel is discharged from the fuel discharge port 24 via the check valve 27, and in parallel with this, the fuel discharge port 25 is appropriately opened and closed to keep the discharge pressure constant.

By containing the fuel filter 10 in the fuel tank 50, the sealing property of each part is not required to be complete. This is because even if there is some leakage, it only leaks into the fuel tank 50 and does not leak outside the vehicle body. In this way, the filter medium 30 is housed in the fuel filter housing 20 and is interposed between the fuel suction port 23 and the fuel discharge port 24, and the check valve 2 is provided between the fuel discharge port 24 and the fuel pipe 51.
The fuel discharge port 25 is connected to the fuel tank 50 through the pressure regulator 40 while being connected to the injector 60 with the fuel tank 50 interposed therebetween.
The number of piping paths between the injector 60 and the injector 60 is one, and thus the number of connection paths can be reduced and the time and effort for ensuring the sealing performance can be reduced.

[Brief description of drawings]

FIG. 1 is a sectional view of a fuel supply system to which a fuel filter according to an embodiment of the present invention is applied.

FIG. 2 is a cross-sectional view showing a state in which the pressure regulator is closed.

FIG. 3 is a cross-sectional view showing a state in which a pressure regulator is open.

FIG. 4 is a schematic configuration diagram of a fuel supply path to which a fuel filter is applied.

FIG. 5 is a sectional view of a conventional fuel filter.

FIG. 6 is a schematic configuration diagram of a fuel supply path to which a conventional fuel filter is applied.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Fuel filter 20 ... Fuel filter housing 23 ... Fuel suction port 24 ... Fuel discharge port 25 ... Fuel discharge port 30 ... Filter material 40 ... Pressure regulator 41 ... Casing 42 ... Discharge path 43 ... Opening 44 ... Small hole 45 ... Cover 46 ... Coil spring 47 ... Valve seat unit 50 ... Fuel tank 60 ... Injector 70 ... Fuel pump

Claims (3)

[Claims] 1. A filter medium is housed in a fuel filter housing to partition the interior thereof, a fuel suction port is formed on the dirty side of the filter medium, and a fuel discharge port is formed on the clean side of the filter medium. A fuel filter integrally formed with a pressure regulator for communicating the inside and the outside when the internal pressure exceeds a predetermined pressure. 2. The fuel filter according to claim 1, wherein the fuel filter is housed in the fuel tank. 3. The fuel filter according to claim 1 or 2, wherein the pressure regulator is open to the clean side in the fuel filter housing.