JPS6254046B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a filter device for liquids, gases, and other fluids, such as a filter device provided in a hydraulic circulation path of an automobile power steering.

The filter device of conventional power steering equipment is installed in the oil reservoir tank, and the tank is connected to the suction side (downstream side) of the oil pump and the return side (upstream side) of the power steering control valve. The oil is configured to flow to the suction side through a filter provided in the tank. In order to prevent damage caused by increased pressure on the return side when the filter becomes clogged, a safety valve is installed in the filter part of the oil reservoir tank. It is designed to flow directly to the suction side via the same safety valve.

In conventional tanks as described above, the safety valve is provided inside the tank, especially in the filter area, so the area of the filter is reduced, and to increase the area, the capacity of the tank itself must be increased. . Further, providing a safety valve itself has disadvantages such as high cost.

On the other hand, in Japanese Utility Model Application No. 50-13047, a pipeline from the discharge side of the pump and a pipeline to the oil supply route side equipped with a main filter are opened at one end of the cylinder, and the supply route is opened at the other end of the cylinder. A pipe line communicating with the downstream side of the main filter is opened, a free piston is provided in the cylinder so that the two openings on the one end side of the cylinder always communicate with each other, and At a position above the opening of the supply channel, a preliminary supply channel is opened that communicates with the filter downstream of the supply channel via another filter, and when the main filter becomes clogged, the free piston moves and the pump A device is shown in which the discharge side and the pre-feed passage are in communication.

This device uses another filter even when supplying oil through a detour when the main filter is clogged, so it has the advantage of not supplying dirty oil, but the safety valve device is large-scale and is expensive. This can be said to have major drawbacks.

The present invention was made in order to eliminate these conventional drawbacks, and by providing the filter itself with a safety valve function in an oil reservoir tank with a filter (generally a fluid filter device), It is characterized by being able to release pressure when the filter is clogged without providing a special safety valve.

The present invention will be explained below with reference to drawings showing embodiments thereof. In FIGS. 1 and 2, reference numeral 1 denotes a cylindrical power steering reservoir tank, which in this example consists of a large diameter portion 10 and a small diameter portion 11. The small diameter portion 11 is provided near the bottom thereof. The large diameter portion 10 and the small diameter portion 11 are provided with joint pipes 10A and 11 integrally therewith, respectively.
A is provided. Joint pipe 11A
is connected to the return side of a power steering control valve (not shown), and the other joint pipe 10A is connected to the suction side of the oil tank.

A filter device 2 is inserted into the large diameter portion 10 of the reservoir tank 1 . In this example, the filter device 2 includes a cylindrical filter support 20 that houses a filter F and is open at one end (bottom);
It has an annular seal holder 21 having a U-shaped cross section and a seal ring 22 held within the seal holder. In this example, the filter F is held in the form of being filled inside the support body 20. The seal holder 21 is fixed to the outer peripheral surface of the open end of the filter support 20 by, for example, screw connection.

A large number of small holes are formed in the closed end and cylindrical portion of the filter support 20 to allow oil to flow therethrough. In addition, the outer periphery of the closing side end (top) of the guide ribs 23, 23, . . .
are provided at four locations in this example. Rib 23
protrude radially outward from the filter support 20, and the distances from the axis of the support 20 to each radial tip are approximately equal. The outer diameter of this rib 23 (outer diameter of a virtual circle passing through each tip)
The outer diameter of the seal holder 21 is formed to be slightly smaller than the inner diameter of the large diameter portion 10 of the tank 1, and the outer diameter of the seal ring 22 is formed to be slightly larger than that.

The filter device 2 configured as described above has a seal ring 22 from the opening (large diameter portion) of the tank 1.
The seal holder 21 is inserted with its side facing down, and is held when the lower end of the seal holder 21 abuts the shoulder between the large diameter part 10 and the small diameter part 11 of the tank 1. Since the seal ring 22 is formed in advance to be larger than the inner diameter of the large diameter portion 10 of the tank 1, when the filter device is fitted into the large diameter portion 10, the seal ring 22 is compressed and deformed between the seal holder 21 and the tank inner wall. The holding force is obtained by the friction. The joint pipe 10A opens to the side of the tank 1, and the seal ring 22 is located below the opening.

As described above, the inside of the tank 1 is partitioned by the filter device 2 into a lower chamber A communicating with the return side and an upper chamber B communicating with the suction side.
The open end of the tank 1 is closed by a ventilation cap 3. Reference numeral 4 in the figure indicates an oil filler port filter, and 5 indicates a gasket. The oil filler port filter 5 is fixed to the small diameter end of a conical cylindrical support member, and has a flange portion provided on the large diameter side, and the flange portion is connected to the tank 1.
It is placed on the shoulder formed at the open end of the cap and is tightened and fixed by the cap 3 via the gasket 5.

Next, the operation of the present invention configured as above will be explained.

Figure 3 shows the flow of oil in a normal state where the filter F is not clogged. The oil that has flowed into the chamber A from the joint pipe 11A flows into the chamber B through the filter F, and then flows into the joint pipe 1.
Flows from 0A to the suction side of the oil pump.
The friction of the seal ring 22 holds the filter device 2 in the mounting position shown. In addition,
The arrows in the figure indicate the flow of oil.

When the filter F becomes clogged, the pressure inside the chamber A increases, and when this pressure increases to the extent that it overcomes the friction between the seal ring 22 and the inner circumferential surface of the large diameter portion 10 of the tank 1, the entire filter device 2 becomes large. Move inside the diameter to the chamber B side. At the position where the seal ring 22 passes through the opening of the joint pipe 10A, the filter device 2 comes into contact with a suitable stopper device in the tank, in this example, the lower end of the oil filler port filter 4, and its movement is stopped. Since the joint pipes 10A and 11A are in direct communication with each other in the chamber A, the return oil flows directly to the suction side without passing through the filter F, thereby avoiding an abnormal increase in pressure and damage to the oil circulation system. .

If the tank 1 is made of a milky white or translucent synthetic resin, such as nylon resin, it is possible to check whether the filter is clogged by visually observing the position of the filter device from the outside. Of course, if the tank is made of transparent glass or acrylic resin, visual inspection will be easier.

FIG. 5 shows an example in which the filter device 2 is inserted in the opposite direction. In the figure, the same parts as in FIG. 1 are indicated by the same reference numerals. In this case, the opening of the joint pipe 10A on the suction side into the tank 1 is located above the seal ring 22. Since the operation and effect are substantially the same as those in the previous example, the explanation will be omitted.

The guide ribs 23 of the filter device 2 are provided to prevent the filter device 2 from falling over (tilting) when it moves within the tank, but only when the seal ring 22 and its seal holder 21 fit into the inner wall of the tank. However, if the above-mentioned inclination can be prevented, it is not necessarily necessary.

The filter F is a cap-shaped filter support 2
0, but this structure itself may be of a known type. In this example, the filter F, in combination with the support body 20, allows oil to flow in the lateral direction (radial direction) and upward direction (axial direction), so in the event of clogging, the entire filter device will be affected. Axial pressure will be applied. Even if the filter F is configured to allow flow only in the lateral direction in the example of FIG. 1, it may be configured so that pressure is applied in the axial direction when the filter is clogged. That is, the filter support 20
In the above example, a large number of small holes are formed at the closed end (top) of the filter, but if the filter is completely sealed, pressure will be applied to the closed end if the filter becomes clogged. Therefore, the filter device 2 can be moved in the axial direction. The same applies to types where the sides (circumferential surfaces) are closed and allow oil to flow only in the axial direction.

The structure of the holder 20 is not limited to the illustrated example, and any structure that can hold the filter may be used.

The joint pipe 11A was set as the return side (upstream side), and the joint pipe 10A was set as the suction side (downstream side).
This also holds true even if 11A is the discharge side of the pump and 10A is the supply side. In short, it is sufficient that the filter is provided in the fluid system so that when the filter becomes clogged, the fluid pressure on the upstream side increases and an axial force is applied to the filter. In that case, the friction of the seal ring 22 may not be able to sufficiently withstand the pressure. Therefore, as shown in FIG. 6, the seal ring 22 is designed to have at least the function of sealing both chambers A and B.
Spring 6 is installed between the filter device and the top of the tank.
An example would be to insert . If the strength is determined so that the filter device 2 moves in the axial direction when the filter F becomes clogged, the same operation and effect as described above can be obtained. In this figure, the same parts as in FIG. 1 are indicated by the same reference numerals. In this example, the joint pipe 11A is provided to open at the lower end of the tank 1.

The structure of the tank 1 is not limited to that shown in the drawings, and may have the same diameter. In that case, the filter device 2 will be located at the bottom of the lower end of the tank 1, but the joint pipe 11A may be opened at the bottom as shown in FIG. As shown in Figure 1, the same joint pipe 11A
When opening from the side, a suitable protrusion may be provided from the bottom of the tank or from the lower end of the filter device to ensure a clearance.

FIG. 7 shows another embodiment of the present invention, in which joint pipes 10A and 11A are opened at the bottom and sides of the tank 1, respectively. Also tank 1
A small diameter cylindrical portion 12 is integrally molded at the bottom. The filter device 2 has a cylindrical filter support 20 consisting of a large diameter portion 24 and a small diameter portion 25, into which a filter F is inserted. Support body 20
A seal holder 21 and a seal ring 22 similar to those described above are attached to the upper and lower ends of. When the filter device 2 is inserted into the tank 1, the upper and lower seal rings 22 have the same holding function as in the embodiment described above (the seal ring 22 on the small diameter portion 25 side is attached to the cylindrical portion 12 at the bottom of the tank). ). The inside of the tank 1 is partitioned into chambers A and B.

Since a large number of small holes are provided around the entire circumference of the large diameter portion 24, the oil flowing in (returning) from the joint pipe 11A passes through the filter F and flows from the joint pipe 11A to the suction side of the oil pump. leak. When the filter F becomes clogged, the pressure on the chamber A side increases, and the filter device 2
rises inside the tank 1 and seals the lower seal ring 2.
2 leaves the cylindrical portion 12, chambers A and B communicate with each other, and the oil from the joint pipe 11A flows directly to the joint pipe 10A without passing through a filter, thereby preventing an abnormal increase in pressure. By using a spring between the cap side of the tank 1 and the filter device, the same actions and effects as in the example shown in FIG. 6 can be obtained. If the movement of the filter device is detected by a combination of a magnet and a reed switch, for example, and displayed on the meter panel, clogging can be confirmed from the driver's seat.

Although the present invention has been described using an oil reservoir tank with a filter for power steering as an example, it can be widely applied to other liquid or gas filter devices.

Since the present invention is constructed as described above, it is possible to obtain a filter device that has a simpler structure and a larger filter area than the conventional filter device. In particular, since there is no need to provide a special safety valve when the filter is clogged, it is extremely advantageous in terms of cost.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing one embodiment of the present invention, and FIG.
The figures are a perspective view of the filter device 2 shown in Fig. 1, Fig. 3 is a schematic cross-sectional view showing the operating state shown in Fig. 1, Fig. 4 is a diagram showing another operating state shown in Fig. 3, and Fig. FIG. 6 is a schematic cross-sectional view showing another example of the present invention; FIG. 7 is a schematic cross-sectional view showing still another example of the present invention; FIG. This figure is another operating state diagram of FIG. 7. Symbols 1...Tank, 2...Filter device, F...Filter, 20...Filter support body, 21...Seal holder, 22...Seal ring.

Claims (1)

[Claims] 1. A filter device is provided in a tank connected to the upstream and downstream sides of a fluid circulation flow path, and the filter device is supported on the inner wall surface of the tank by a seal ring provided on its outer periphery, and the inside of the tank is filled with the filter device. By partitioning the upstream side and the downstream side by the device and the seal ring, the fluid on the upstream side is configured to flow downstream through the filter device, and when the pressure on the upstream side increases to a predetermined value, the fluid on the upstream side flows through the filter device. A filter device is characterized in that it moves within a tank by overcoming friction between a seal ring and an inner wall of the tank, and is configured to directly communicate flow paths on the upstream side and the downstream side within the tank.