JPH01266818A - Filter device - Google Patents

Abstract

PURPOSE:To surely catch foreign matter and to prevent the caught foreign matter from being dispersed again by disposing the check valve allowing a fluid to flow only from the inlet port of one side to the outlet port of the other side, in parallel with a filter element. CONSTITUTION:The check valve 21 allowing an oil liquid to flow only from the chamber C side to the chamber A side is disposed in a filter pressing plate 19 so as to be parallel with the filter element 16 in a filter case 11, and the oil liquid is allowed to pass through the filter element 16 only when the pressure oil is returned to a tank side from a pressure oil cylinder. Consequently, the foreign matter, such as abraded powder generated in flow direction changing- over valves, is surely caught by the filter element 16 when the pressure oil is returned through an inlet and outlet port 14 to the tank side after to pressure oil has been supplied to the pressure oil cylinder through the check valve 21 and an inlet and outlet port 15. And the foreign matter once caught by the filter element is not dispersed again in the oil liquid by the flow of reverse direction.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is provided between a hydraulic power source and an actuator in a hydraulic circuit, for example, and is suitable for removing foreign substances from oil fluid as a fluid. The present invention relates to a filter device used.

[Conventional technology]

FIG. 5 shows a hydraulic circuit for adjusting the 4j height provided with a filter device of the prior art.

In the figure, reference numeral 1 indicates a pump unit constituting a fluid source, and the pump 2) 1 includes a tank 2 that accommodates oil as a fluid, and a hydraulic cylinder 5 that transfers the oil in the tank 2. It is comprised of a hydraulic pump 3 for supplying pressure towards the target, and a filter 4 for removing dust provided between the hydraulic pump 3 and a directional switching valve 7, which will be described later. Reference numeral 5 denotes a hydraulic cylinder for adjusting vehicle height which constitutes an actuator. The hydraulic cylinder 5 is composed of a tube 5A and a rod 5B extending and contracting from the tube 5A. The projecting end of the rod 5B and the tube 5
One end of A is provided between the vehicle body side and the axle side (neither are shown). The rod 5B of the hydraulic cylinder 5 expands and contracts by supplying and discharging pressure oil from the pump unit 1, thereby adjusting the vehicle height.

Reference numeral 6 indicates a hydraulic pipe connected between the pump unit l and the hydraulic cylinder 5, and 7 indicates a directional switching valve provided in the middle of the hydraulic pipe 6. The directional switching valve 7 is a 3-point, 3-position electromagnetic valve. It consists of a type directional control valve, which is always in the neutral position (A).
When power is applied from the outside, the inside is switched from position 1 (a) to switching position (b) or (c). and,
When the directional switching valve 7 is switched to the switching position (B), the pressure oil from the hydraulic pump 3 flows from the piping section 6A side of the hydraulic piping 6 toward the hydraulic cylinder 5, and the directional switching valve 7 is switched to the switching position (C).
So, how is the pressure oil in the hydraulic cylinder 5 arranged on the tank side? Part 6
It is discharged into tank 2 via B.

Reference numeral 8 indicates a filter device located between the directional control valve 7 and the hydraulic cylinder 5 and provided in the middle of the hydraulic piping 6. The filter device 8 has a pair of inflow and outflow ports 9 at both ends in the axial direction.
A cylindrical filter case 9 provided with filters A and 9B, and a filter element lO provided within the filter case 9.
It is roughly composed of. And the filter device 8
prevents foreign matter such as abrasion powder generated in the directional control valve 7 and dirt in the oil fluid from entering the hydraulic cylinder 5, and also prevents foreign matter such as abrasion powder and dirt in the oil fluid generated in the hydraulic cylinder 5 from entering the hydraulic cylinder 5. It is configured as a two-way filter that prevents 11- from entering the directional switching valve 7.

In the conventional technology configured in this way, a vehicle-mounted HH
When the lj product becomes low due to an increase in Tube 5 of hydraulic cylinder 5 via 8 etc.
A and extends the rod 5B to raise the vehicle height.

In addition, when the vehicle height increases due to a decrease in the loaded weight, etc., the directional control valve 7 is switched to the switching position (c), and the pressure oil in the hydraulic cylinder 5 is passed through the filter device 8 to the tank 2.
The fuel is discharged to the inside, and the lock 15B is reduced to lower the vehicle height.

As described above, the filter device 8 removes foreign substances from the bidirectionally flowing hydraulic fluid (pressure oil) using the filter element IO, so that clean hydraulic fluid can be supplied to the hydraulic cylinder 5 and the like. In addition, a filter 4 installed in the bomb unit 1 removes foreign matter such as abrasion powder generated from the hydraulic pump 3 and dirt in the oil fluid, and prevents this foreign matter from entering the directional control valve 7, etc. It has become.

[Problem to be solved by the invention]

By the way, in the prior art described in -1-, the filter device 4
Since 8 is configured as a bidirectional filter, when the directional switching valve 7 is switched to the switching position (B) and pressure oil from the hydraulic pump 3 is supplied to the hydraulic cylinder 5, the filter element 10 is used to filter out the oil in the oil. Even if a foreign object is captured, when the directional control valve 7 is switched to the switching position 71 (c) and the pressure oil is discharged from the hydraulic cylinder 5 to the tank 2 side, the oil flow in the opposite direction will cause the above-mentioned Foreign matter may be dispersed into the oil from the filter element 10 and may enter the directional control valve 7, resulting in a problem that the directional control valve 7 and the like may malfunction.

The present invention has been made in view of the problems of the prior art described above.1 The present invention makes it possible to reliably remove foreign substances from the oil by always making the flow of the oil passing through the filter element in one direction. To provide a filter device which can reliably prevent foreign matter once captured by a filter element from being dispersed into an oil liquid again.

[F stage for solving problems]

A feature of the configuration adopted by the present invention in order to solve the above-mentioned problems is that a check valve is provided in parallel with the filter element to allow fluid to flow only from one inflow/outflow port to the other outflow/inflow port. That's true.

[Effect]

With the configuration described in -1-, the fluid flowing from one inflow/outflow port to the other outflow/inflow port does not pass through the filter element, but flows through the check valve, and flows in the opposite direction. Only the fluid is allowed to flow through the filter element, and foreign substances and the like can be reliably removed.

〔Example〕

Embodiments of the present invention will be described below with reference to FIGS. 1 to 4. In the embodiment, the same components as those of the prior art shown in FIG. 5 described above are denoted by the same reference numerals, and the explanation thereof will be omitted.

Thus, FIGS. 1 and 2 show a first embodiment of the present invention.

In the figure, reference numeral 11 indicates a cylindrical filter case formed as a closed container, and the filter case 11 has a bottom portion 1.
2A and a cylindrical portion 12B, the case body 12 has a bottomed cylindrical shape and has an enlarged diameter portion 12c at the inner periphery on the tip side of the cylindrical portion 12B.
and a lid 13 which is screwed onto the tip of the enlarged diameter portion 12C of the case body 12 and which covers the case body 12. On the inner surface of the lid 13, there is a concentric large diameter spring holder. Part 13A
and a small diameter spring receiving portion 13B are formed. In addition, on the inner side of the bottom 12A of the case body 12, a packing 1, which will be described later, is provided.
Four circular parts 12D are formed at the shallow bottom for positioning the parts 7 and the like.

Reference numeral 14 indicates one inflow/outflow port bored in the center of the lid body 13, and the inflow/outflow port 14 is arranged to be located radially inside the spring receiving portion 13B, as shown in FIG. It is connected to a directional control valve 7 and a pump unit l via hydraulic piping 6 and the like. Reference numeral 15 indicates the other inlet/outlet port bored in the center of the bottom 12A of the case body 12, and the inlet/outlet port 15 is disposed so as to be located inside the recess 120 in the radial direction, as shown in FIG. It is connected to a hydraulic cylinder 5 via a hydraulic pipe 6.

Reference numeral 16 indicates a filter element for removing dust provided inside the case body 12. The filter element 16 is formed into a cylindrical shape by mesh such as wire mesh, and its base end is connected to the case body through an annular parkin 17. 12 recesses 12
D and is fixed with a retainer fE. Also,
The filter element 16 is supported at its distal end by a filter holder 19, which will be described later, and is positioned substantially coaxially within the case body 12. The filter element 16 defines the inside of the case body 12 into inner and outer chambers A and H through the filter holder 19, and the chambers A are the inflow and outflow ports 1.
5, it is always in communication with the hydraulic cylinder 5 side. Reference numeral 18 indicates an annular packing inserted between the tip of the filter element 16 and the filter holder 19.

Reference numeral 19 indicates a filter holder that is located between the lid body 13 and the filter element 16 and is slidably inserted into the enlarged diameter portion 12C of the case body 12, and the filter holder 19 is formed in the shape of a cylinder with a lid. An annular flange portion 19A having an outer diameter corresponding to the inner diameter of the enlarged diameter portion 12G is provided on the outer peripheral side thereof.

On one side of the filter holder 19, another spring receiving part 19B is protruded in a circular shape, facing the spring receiving part 13B of the lid body 13, and on the radially inner side of the spring receiving part 19B is a filter holder. A sleeve hole 19C is bored through the lid portion 19 in the axial direction.

Further, on the other side of the filter holder 19, a cylindrical portion 1 is slidably inserted into the inner periphery of the distal end side of the filter element 16.
For example, three U-shaped notches 19E, 19E, . . . are formed at predetermined intervals in the circumferential direction, extending in the axial direction from the end surface of the cylindrical portion 19D. The cylindrical portion 19D of the filter holder 19 slidably supports the distal end side of the filter element 16, and when the filter holder 19 slides against a setting spring 20, which will be described later, each notch 19E The chambers A and B are communicated with each other on the gasket 18 side through the gasket 18 side. Further, the flange portion 19A of the filter holder 19 has sleeve holes 19F in the axial direction at predetermined intervals in the circumferential direction.

19F, . . . are drilled, and the six oil holes 19F are connected to the lid body 13.
, the chamber C between the filter holders 19 is communicated with the chamber B.

20 is located between the lid body 13 and the filter holder 19,
A setting spring disposed between the spring receivers 13B and 19E is shown, and the setting spring 20 presses the filter holder 19 onto the tip of the filter element 16 with the seal 18 with a predetermined spring load.
This ensures that foreign matter in the oil flowing between chambers A and B is removed by the filter element 16. Here, the setting spring 20 is the filter presser 1
9 together with the relief valve 24 as shown in FIG.
When the filter element 16 is clogged with foreign matter and the pressure inside the chamber A becomes high, the filter holder 19 is allowed to slide in the axial direction due to the pressure at this time, and the chamber A is removed through each notch 19E. , B are communicated with each other. Therefore, the spring load of the setting spring 20 is
Pressure loss when 6 becomes clogged and oil passes through (
The pressure inside the chamber A is set to a value corresponding to the pressure inside the chamber A when the resistance (resistance) increases.

Reference numeral 21 denotes a check valve disposed inside the filter holder 19. The check valve 21 is fixed to the lid of the filter holder 19, and has a valve seat 21A corresponding to the sleeve hole 19G and a radial communication hole 21B. The formed valve case 21G and the pole-shaped valve body 21 seated on and off the valve seat 21A of the valve case 21C.
0, and a valve spring 2 disposed between the valve body 21D and the spring receiver 21E to always bias the valve body 21D in the valve-closing direction]
The valve spring 21F is formed of a coil spring or the like with a weak spring load. The check valve 21 is located between the inflow and outflow ports 14 and 15, and is arranged in parallel with the filter element 16, and allows the flow of oil only from the inflow and outflow port 14 side to the outflow and inflow port 15 side. (See Figure 2).

Furthermore, 22 is a flange portion 19A- of the filter holder 19.
Another check valve is shown which is disposed on the side and normally closes each sleeve hole 19F, and the check valve 22 is formed of a thin annular plate or the like,
The valve spring 23 disposed between the valve A and the valve spring 23 is always biased in the direction of the valve closing force. The check valve 22 is arranged in series with the filter element 16 between the inflow and outflow ports 14 and 15! from the inflow/outflow port 15 side to the outflow/inflow port 14
The valve spring 23 is designed to allow oil to flow only toward the side (see FIG. 2), and the valve spring 23 is formed of a coil spring or the like with a relatively weak spring load.

The filter device according to this embodiment has the above-mentioned configuration, and has the inflow and outflow ports 14 and 15 of the filter case 11.
is connected between the directional control valve 7 and the hydraulic cylinder 5 via a hydraulic pipe 6, as shown in FIG.

Then, when the directional control valve 7 is switched to the switching position (b),
Pressure oil from the hydraulic pump 3 flows into the chamber C from the inflow/outflow port 14, opens the valve body 210 of the check valve 21, flows into the chamber A, and then flows from the inflow/outflow port 15 to the hydraulic pipe 6.
It is supplied to the hydraulic cylinder 5 via. Also, when the directional control valve 7 is switched to the switching position (), the hydraulic cylinder 5
Pressure oil is taken out from inside, flows into the chamber A from the inflow/outflow port 15, and since the flow to the chamber C side is cut off by the check valve 21, it passes through the filter element 16 and enters the chamber. At this time, foreign substances in the oil are removed by the filter 16, and then the check valve 2
2 is opened to flow from the chamber B to the chamber C, and is discharged into the tank 2 from the inflow/outflow port 14 via the directional control valve 7 or the like.

Furthermore, with the directional control valve 7 switched to the switching position (c), while the oil passes through the filter element 16 as described above, the filter element 16 is prevented from becoming clogged by foreign matter in the oil. When the pressure loss increases, the pressure inside chamber A becomes high, so the pressure at this time causes the filter holder 19 that constitutes the relief valve 24 to move toward the chamber C side against the setting spring 20. chamber A.
, B are communicated through each notch 19E of the filter holder 19, and the pressure in the chamber A is relieved to the chamber B side, and the pressure oil in the hydraulic cylinder 5 is circulated through the chambers A, B, and C in this order. Then, it can be returned to the tank 2 side, and the vehicle height adjustment by the hydraulic cylinder 5 can be continued.

In this embodiment, a check valve 21 that allows oil to flow only from the chamber C side to the chamber A side is disposed in the filter holder 19 in the filter case 11 in parallel with the filter element 16, and the hydraulic cylinder Since the configuration is such that the pressure oil is passed through the filter element 16 only when returning pressure oil from 5 to the tank 2 side, foreign matter such as wear powder generated in the directional switching valve 7 etc. is removed from the pressure oil once supplied to the hydraulic cylinder 5 side. When the foreign matter is returned to the tank 2 side after being removed, the foreign matter is reliably removed by the filter element 16, and the foreign matter once captured by the filter element 16 as in the conventional technology is dispersed into the oil liquid by the flow in the opposite direction. This can effectively prevent foreign matter from entering the directional switching valve 7 and causing malfunction.

In addition, since the check valves 21, 22, etc. are assembled to the filter holder 19 and are compactly stored within the filter case 11, it is possible to prevent the filter case 11 from becoming larger due to the check valves 21, 22, etc. The entire structure can be made compact, and there is no need to install special piping.

The filter device can be easily integrated into the hydraulic circuit used in the prior art.

Furthermore, since the relief valve 24 consisting of the filter holder 19 and the setting spring 20 is built into the filter case 11, even if the filter element 16 becomes clogged, it is difficult to adjust the vehicle height using the hydraulic cylinder 5. This has various effects, such as being able to prevent this from happening and allowing vehicle height adjustment to continue.

Next, FIGS. 3 and 4 show a second embodiment of the present invention, and a feature of this embodiment is that the check valve 22, valve spring 23, etc. used in the first embodiment can be omitted. It's what I did.

In the figure, 31 indicates a filter case, and the filter case 31 consists of a case main body 32 and four bodies 33, almost the same as the filter case 11 described in the first embodiment. A portion 32B and a shallow recessed portion 32C are provided. Further, a spring receiving portion 33A is recessed in the lid body 33, and one inflow/outflow port 34 is bored inside the spring receiving portion 33A in the radial direction.

The other inflow/outflow port 35 is bored in the bottom 32A of the case body 32, and the outflow/inflow port 34.35 is connected to a hydraulic pipe 6 between the directional control valve 7 and the hydraulic cylinder 5 as shown in FIG. connected via.

Reference numeral 36 designates a filter element provided within the case body 32, and the filter element 36 is formed substantially in the same manner as the filter element 16 described in the first embodiment.
Gaskets 37 and 38 are provided on both ends in the axial direction. 39 connects the filter element 36 to the case body 3
2 shows the filter holder supported between the fourth part 32C,
The filter holder 39 has a sleeve hole 39A on the lid side and is formed into a right-hand lid cylindrical shape, and is provided with an annular stepped protrusion 39B on the outer periphery thereof. The small diameter side of the stepped protrusion 39B is slidably inserted into the inner periphery of the distal end side of the filter element 36, and by covering the distal end side of the filter element 36, a chamber A is formed between the inside and the outside. , B are defined. Furthermore, notches 39C are formed at predetermined intervals in the circumferential direction on the small diameter side of the stepped protrusion 39A, and the filter retainer 3
9 constitutes a relief valve 42 as shown in FIG. 4 together with a setting spring 40 which will be described later.

Reference numeral 40 indicates a setting spring disposed between the spring receiving part 39D protruding from one side of the filter holder 39 and the spring receiving part 33A of the lid body 33. 39 is pressed against the tip of the filter element 3 through the gasket 38, and the relief pressure by the filter holder 39 (relief valve 42) is determined in substantially the same way as the setting spring 20 described in the first embodiment. Then, when the filter element 36 becomes clogged and the pressure inside the chamber A exceeds this relief pressure, the setting spring 40
The filter holder 39 is allowed to slide, and the chambers A and B are communicated through each notch 39G of the filter holder 39.

Further, reference numeral 41 indicates a check valve disposed within the filter holder 39, and the check valve 41 is disposed in parallel with the filter element 36 in substantially the same manner as the check valve 21 described in the first embodiment. The valve case 4IC includes a valve seat 41A, a radial sleeve hole 41B, etc., a pole-shaped valve body 41D, a spring receiver 41E, and a valve spring 41F. However, in the check valve 41, the valve spring 41
The spring load of F is small, and the valve element 410 opens against the valve spring 41F at a pressure smaller than the pressure loss (resistance) when the oil fluid flows between chambers B and A.

The filter device according to this embodiment has the above-described configuration and can obtain almost the same effects as those of the first embodiment, but in particular, in this embodiment, the chamber B is The filter holder 39 is formed to have a smaller diameter than the cylindrical portion 32B of the case body 32 so as to be in continuous communication with the filter element 36, and the check valve 41 is opened at a pressure smaller than the pressure loss caused by the filter element 36. The check valve 22'''g- used in the embodiment described above is no longer necessary, the number of parts can be reduced, and the workability during assembling can be improved.

In addition, in each of the above embodiments, the filter device is ・F height,
J8! Although the present invention has been described using an example of application to a maintenance hydraulic circuit, the present invention is not limited thereto, and can also be applied to various fluid pressure circuits, such as a hydraulic circuit for driving an actuator other than the hydraulic cylinder 5. .

〔Effect of the invention〕

As described in detail below, according to the present invention, the check valve that allows fluid to flow only from one inflow/outflow port to the other outflow/inflow port is arranged in parallel with the filter element. For example, when a directional valve is disposed between a fluid source and the filter device, and the fluid is supplied from the fluid source to the actuator side and then returned to the tank side by switching the directional valve, The filter element can reliably remove foreign matter, etc., and prevent the captured foreign matter from entering the directional control valve or the like and causing malfunction.

[Brief explanation of the drawing]

1 and 2 show a first embodiment of the present invention, FIG. 1 is a longitudinal sectional view of a filter device, 214 is a hydraulic circuit diagram, and FIGS. 3 and 4 are a second embodiment of the present invention. 3 is a longitudinal sectional view of the filter device, FIG. 4 is a hydraulic circuit diagram, and FIG. 5 is a hydraulic circuit diagram showing a conventional technique. 1... Pump unit (fluid source), 2... Tank,
3... Hydraulic pump, 4... Filter, 5... Hydraulic cylinder, 6... Hydraulic piping, 7... Directional switching valve, 1
1.31... Filter case, 12.32... Case body, 13.33... Lid body, 14, 15, 34.3
5... Outflow/inflow hoard, 16.36... Filter element, 19.39... Filter holder, 19C, 39
A...Cuff hole, 20.40...Setting spring, 21.41
...Check valve. Figure 1 IJA IA;
Snake Figure 2 Figure 4 Figure 3 Figure 5

Claims (1)

[Claims] A filter device comprising a cylindrical filter case having one inflow/outflow port and another inflow/outflow port connected between a fluid source side and an actuator side, and a filter element provided within the filter case. . A filter device, characterized in that a check valve is provided in parallel with the filter element to allow fluid to flow only from one inflow/outflow port to the other outflow/inflow port.