JP2001232116A - Filter device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce labor and time for the exchange work of a filter element. SOLUTION: A 1st filter element 13 for filtering pilot line oil and a 2nd filter element 14 for filtering drain line oil are incorporated in a case 11 of a filter device 10 so as to be separated liquid tightly with a partition plate 15, and the 1st and 2nd filter inlet side and outlet side ports 11a-11d respectively communicated with the oil introducing side and oil discharge side of each filter element are formed in the case 11.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention belongs to the technical field of a filter device provided in a machine having various hydraulic devices such as a construction machine.

[0002]

2. Description of the Related Art Generally, a hydraulic circuit of a machine having various hydraulic devices such as a construction machine is provided with a filter for removing pollutants (contaminants) in oil. It is provided corresponding to each system such as a main system, a pilot system, and a drain constituting the hydraulic circuit. That is, taking the hydraulic circuit of the hydraulic excavator shown in FIG. 4 as an example,
In FIG. 4, 1 is an engine, 2 and 3 are main pumps,
4 is a pilot pump, 5 is an oil tank, 6 is various hydraulic actuators such as a traveling motor and a boom cylinder, 7 is a main system control valve for controlling the supply and discharge of hydraulic oil to each of the hydraulic actuators 6, and 8 is an operating tool. A pilot control valve for supplying a pilot pressure to the main control valve 7 based on the pilot pressure. The main system return oil passage from the main system control valve 7 to the oil tank 5 has a large capacity corresponding to the large flow rate oil discharged from the main pumps 2 and 3, and has a pressure loss even at a large flow rate. A coarse return system filter 9 is provided so as not to be damaged. The pilot system from the pilot pump 4 to the pilot system control valve 8 (or the control system main valve 7) has a small capacity corresponding to the small flow rate oil required for the highly accurate pilot system control valve 8, and A fine pilot system filter 27 is provided. further,
In the drain system from the hydraulic actuator 6 and the drain oil passages of the main pumps 2 and 3 to the oil tank 5, a small-capacity drain filter 28 corresponding to the amount of drain oil is provided. In order to prevent unnecessary back pressure (case pressure) from being applied to the motor system and the pump system, a filter coarser than the pilot system filter 27 is employed.

[0003]

By the way, the filter is
It is necessary to periodically replace the filter element due to clogging as it is used.However, in the above-mentioned conventional type, since the filters are individually provided in each of the main, pilot and drain systems, the user needs to remove the filter of each system. Need to be replaced individually, which is troublesome and troublesome. Further, there is a problem that a space for disposing a filter must be secured in each system, and there is a problem to be solved by the present invention.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned circumstances, and has been made for the purpose of solving these problems, and comprises a plurality of liquid-tightly partitioned filter elements. A filter device including a case in which the plurality of filter elements are housed, and a plurality of inlet ports and outlet ports formed in the case in a state of communicating with the oil introduction side and the oil outlet side of each filter element, respectively. It was done. By doing so, a plurality of filter elements can be replaced at a time, and the efficiency of the replacement operation is improved. In this device, the filter device is provided with a check valve that allows oil to flow from the inlet port to the filter element, but prevents oil from flowing from the filter element to the inlet port. Contaminants captured by the element can be prevented from flowing out of the inlet port. This filter device can be employed, for example, in a case where oil of a pilot system and a drain system of a hydraulic circuit provided in a construction machine is respectively filtered by a corresponding filter element. The drain filter element can be replaced at a time. In addition, the arrangement space for the filter device may be secured in one place in both the pilot system and the drain system, so that there is an advantage that the space can be easily secured. Further, the present invention provides a filter comprising: a filter element; a case in which the filter element is provided; and an inlet port and an outlet port formed in the case in communication with the oil introduction side and the oil discharge side of the filter element. In the device, the filter device is provided with a check valve that allows oil to flow from the inlet port to the filter element, but prevents oil from flowing from the filter element to the inlet port. And by doing this,
When the filter element is replaced, it is possible to prevent the contaminants captured by the filter element from flowing out from the inlet port.

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, a first embodiment of the present invention will be described with reference to FIGS. First, FIG. 1 shows a schematic diagram of a hydraulic circuit of a hydraulic excavator. In FIG.
1 is an engine, 2 and 3 are a main pump, 4 is a pilot pump, 5 is an oil tank, 6 is various hydraulic actuators such as a traveling motor and a boom cylinder provided on a hydraulic shovel, and 7 is hydraulic oil for each hydraulic actuator 6. A main system control valve for supplying and discharging control, 8 is a pilot system control valve for supplying a pilot pressure to the main system control valve 7 based on operation of an operating tool, and 9 is a main system for returning from the main system control valve 7 to the oil tank 5. The return filter 10 disposed in the return oil passage is a filter device, and the present invention is implemented in the filter device 10.

The structure of the filter device 10 will be described with reference to FIG.
And a filter element unit 12 detachably mounted in the case 11. The filter element unit 12 further includes first and second filter elements 13 and 14, and these filter elements 13 and 14. The partition plate 15 and the seal member 16 that partition the space liquid-tight are integrally assembled.

The case 11 includes a hollow cylindrical case main body 17 having one side opened, and a case cover 18 for covering the opening side of the case main body 17. By removing the case cover 18 from the case body 17, the filter element unit 12 can be attached and detached inside the cylinder of the case body 17. Reference numeral 19 denotes a sealing material for sealing between the case body 11 and the case cover 18.

Further, the case 11 has a first filter inlet port 11a and a first filter outlet port 11a.
b, a second filter inlet port 11c and a second filter outlet port 11d. here,
The first filter inlet port 11 a is connected to the pilot pump 4 via the pipe 20, while communicating with the oil introduction side of the first filter element 13. The first filter outlet port 11b communicates with the oil outlet side of the first filter element 13 and is connected to the pilot control valve 8 via a pipe 21. Further, the second filter inlet side port 11c is connected to the hydraulic actuator 6
Of the motors and the drain oil passages 22b of the main pumps 2 and 3 are connected via a pipe 22, while communicating with the oil introduction side of the second filter element 14. Furthermore, the second filter outlet side port 1
1 d communicates with the oil outlet side of the second filter element 13 and is connected to the oil tank 5 via the pipe 23.

That is, the first filter element 13 is disposed in a pilot system from the pilot pump 4 to the pilot system control valve 8, and the second filter element 14 is provided with the hydraulic actuator 6 and the main pump 2,
3 is provided in a drain system extending from the drain oil passages 22 a and 22 b to the oil tank 5. And the filter device 10
One having a capacity suitable for the pilot system and the drain system (the return filter 9 disposed in the main system return oil passage)
Smaller capacity). In this embodiment, the first filter inlet port 11a is formed in the case cover 18, and the first filter outlet port 11b, the second filter inlet port 11c, and the second filter outlet port 11d are formed in the case body 17. However, without being limited to this, for example, all the ports 11a to 11a
1d may be formed on the case body 17.

In the apparatus configured as described above, the filter device 10 is formed by detachably mounting a filter element unit 12 in a case 11, and the filter element unit 12 filters pilot oil. The first filter element 13 and the second filter element 14 for filtering the drain-based oil
And are integrally assembled in a liquid-tight partition state.

As a result, the filter elements 13 and 14
Is clogged, the filter element unit 12
Is removed from the case 11 and replaced, so that the filter elements 13 and 14 of the pilot system and the drain system can be replaced at a time, thereby improving the efficiency of the replacement work. In addition, as for the space for disposing the filter device 10, it is only necessary to secure one place in both the pilot system and the drain system, so that there is an advantage that the space can be easily secured.

Next, FIG. 3 shows a second embodiment of the present invention. The filter device 24 according to the second embodiment is shown in FIG.
The first filter element 13 for filtering the pilot oil and the second filter element 14 for filtering the drain oil are integrally assembled as a filter element unit 12. Ports 11a to 11d communicating with the oil introduction side and the oil outlet side of the filter elements 13 and 14 are formed in the same manner as in the first embodiment. The first filter inlet side port 1
1a is provided with a poppet type check valve 25 that allows the flow of oil from the pipe 20 to the first filter element 13 but prevents the flow in the reverse direction. Similarly, the flow of oil from the pipe 22 to the second filter element 14 is allowed in the second filter inlet port 11c,
A poppet-type check valve 26 that prevents the flow in the reverse direction is mounted. And these check valves 25, 26
As a result, the filter element unit 12 is
From the first and second filter elements 1
The contaminants captured in 3 and 14 can be prevented from flowing out to the pipes 20 and 22 side.
In the second embodiment, the same components as those in the first embodiment (the same components) are denoted by the same reference numerals, and the detailed description thereof is omitted. Here, reference numerals 25a and 26a denote bullets for biasing the check valves 25 and 26. Also, FIG. 1 shares the one of the first embodiment.

In the second embodiment configured as described above, the same operation and effect as those of the first embodiment can be obtained. However, in the second embodiment, a filter device is provided. When the filter element unit 12 is removed from the case 11 by the check valves 25 and 26 attached to the inlet ports 11a and 11b of the
There is an advantage that the contaminants captured by the first and second filter elements 13 and 14 can be prevented from flowing out of the inlet ports 11a and 11b and returning to the hydraulic circuit of the excavator.

The present invention is, of course, not limited to the first and second embodiments. For example, when the pressure of the oil passage on the inlet side becomes higher than the set pressure, the filter passes through the filter element. The design of the relief valve, which allows the oil in the oil passage on the inlet side to flow to the outlet side without performing this, can be changed as appropriate, for example, by incorporating the relief valve into the filter device corresponding to each filter element.

[Brief description of the drawings]

FIG. 1 is a schematic hydraulic circuit diagram of a hydraulic shovel.

FIG. 2 is a diagram illustrating a filter device according to a first embodiment.

FIG. 3 is a diagram illustrating a filter device according to a second embodiment.

FIG. 4 is a schematic hydraulic circuit diagram of a conventional hydraulic shovel.

[Explanation of symbols]

 Reference Signs List 10 filter device 11 case 11a first filter inlet side port 11b first filter outlet side port 11c second filter inlet side port 11d second filter outlet side port 13 first filter element 14 second filter element 15 partition plate 24 filter device 25 Check valve 26 Check valve

Claims (4)

[Claims] 1. A plurality of filter elements which are liquid-tightly partitioned, a case in which the plurality of filter elements are provided, and a case formed in a state communicating with an oil introduction side and an oil discharge side of each filter element. A filter device comprising: a plurality of inlet ports and outlet ports. 2. The filter device according to claim 1, wherein the filter device is provided with a check valve that permits oil to flow from the inlet port to the filter element, but prevents oil from flowing from the filter element to the inlet port. Filter device. 3. The filter according to claim 1, wherein the filter device filters pilot-system and drain-system oils of a hydraulic circuit provided in the construction machine with respective corresponding filter elements. apparatus. 4. A filter comprising: a filter element; a case in which the filter element is provided; and an inlet port and an outlet port formed in the case so as to communicate with an oil introduction side and an oil outlet side of the filter element. A filter device, wherein the filter device is provided with a check valve that permits oil to flow from the inlet port to the filter element but prevents oil from flowing from the filter element to the inlet port.