JPH0525006U - Return circuit filter base structure - Google Patents

Abstract

(57) [Summary] (Modified) [Purpose] To provide a base for fixing a filter for simplifying an oil return circuit connected to an oil tank. [Structure] The base is provided with a plurality of return holes that connect a return circuit that does not pass through the filter and a return hole that passes through the filter. Connect to the oil tank by.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a filter base structure provided in a return circuit for returning return oil from hydraulic equipment such as power shovels that operates hydraulically such as construction machinery to an oil tank. More specifically, it relates to a filter passage structure. The present invention relates to a filter base structure in which a circuit and a filter non-passage circuit are integrally formed.

[0002]

[Prior Art]

 A construction machine such as a power shovel has a swing frame, a boom, an arm connected to a tip of the boom, a bucket provided at a tip of the arm, and the like, and these are each configured to be operated by a cylinder. The oil supplied to these many cylinders is returned to the oil tank through the respective return circuits, and at this time, it passes through the filter circuit to purify the oil.

[0003]

[Problems to be solved by the device]

 Many oil return circuits are designed to filter some of the oil used in the hydraulic circuit without passing through the filter. Therefore, it is necessary to provide a circuit that passes the filter and a circuit that does not pass the filter in the return circuit of the conventional oil, so that there are multiple connections on the oil tank side, and there are also connections. However, the number of parts required for assembly is increased and the number of assembling steps for mounting these components is also increased, resulting in cost reduction. In addition, a large number of pipes are arranged in a complicated manner at the part where the pipes are connected to the oil tank, and the installation space of the oil tank is narrowed, which makes mounting difficult.

As described above, in the conventional device, it is necessary to separately provide a passing circuit that allows the filter to pass therethrough and a non-passing circuit that does not allow the filter to pass therethrough, and as a result, various kinds of defects have occurred as described above. However, the present invention aims to eliminate this drawback.

[0005]

[Means for solving the problem]

 The present invention for achieving the above object is a return circuit for returning return oil from a hydraulic device to a single oil tank through a plurality of return circuits, and a filter passage circuit and a filter which are respectively connected to the return circuit. In addition to being integrally formed with a non-passage circuit, a filter base having a single recirculation hole is attached to an oil tank through this single recirculation hole.

That is, a plurality of return oil supply ports to be supplied to one filter base are provided, and most of these supply ports are filter non-passing circuits that do not pass through the filter. The supply port is a filter passage circuit that passes through the filter, and the filter non-passage circuit and the route that passes through the filter are configured to return to the oil tank via one return port.

[0007]

[Work]

 Therefore, the return oil from multiple hydraulic devices is returned to a single oil tank via multiple return circuits, which have multiple open filters on the integrally formed filter base. It is connected to a passage circuit, and one or a few of them are connected to the filter passage circuit, filtered by the filter, passed through the non-passage circuit, merged with the oil, and returned to the oil tank. Therefore, the number of parts for fittings to be attached to the oil tank is significantly reduced, and the number of assembly steps is reduced, resulting in cost down. Further, the filter base can be downsized.

[0008]

【Example】

 The present invention will be described in detail with reference to the drawings. FIG. 1 is a side view of an oil tank provided with a device according to the present invention, and FIG. 2 is an enlarged view of a main part of the device according to the present invention. As described above, the construction machine is provided with a large number of hydraulic equipment such as cylinders, and the oil supplied to the construction machine is returned to the oil tank 2 through the return pipe 1. A one-piece filter base that is composed of a filter non-passing circuit 1a that does not pass through the filter and a filter passing circuit 1b that passes through the filter, and is fixed corresponding to the inflow hole 3a opened in the side plate 3 of the oil tank 2. It is fixed to 4 respectively.

The filter base 4 is a casting product, and one side is provided with a passage 5a to which the filter non-passage circuit 1a is connected and a passage 5b to which the filter non-passage circuit 1b is connected. A return hole 5d is provided via a communication hole 5c to which the passage circuit 1a is connected. A filter mounting seat 6 is provided below the filter base 4, and the mounting seat 6 has a screw portion 6a, which is a return hole for purified oil, in the central portion thereof, and next to it. Each has an outflow hole 6b connected to the passage 5b. Reference numeral 7 is a cartridge type filter, in which the opening of the container-like main body is closed by a top plate. A screw portion is formed in the center of the top plate, the filter member 7a is housed inside the main body, and the screw portion provided in the center of the upper portion is screwed into the screw portion 6a of the mounting seat 6 to thereby filter the filter base. The outflow hole 6b and the supply hole 7a of No. 4 are connected. A flange 5e is integrally formed at the ends of the passages 5a and 5b of the filter base 4, and a flange (or holder) 1c is integrally formed at the ends of the filter non-passage circuit 1a and the filter passage circuit 1b. Is configured to connect.

Oil that has operated a hydraulic device such as a cylinder flows back through the circuits 1a and 1b, but the two circuits 1a flow into the reflux hole 5d side through the communication hole 5c. The remaining filter passage circuit 1b flows into the filter 7 through the passage 5b and the inflow hole 6b, and the oil filtered by this flows out from the discharge hole 6c in which the screw portion 6a is formed and flows into the return hole 5d. They join and flow back into the oil tank 2 through the inflow hole 3a. A check valve 8 whose opening pressure is adjusted by spring pressure is provided in the communication hole 5b connected to the filter passage circuit 1b, and the filter 7 is clogged and the internal pressure of the check valve 8 falls within an allowable range. When it exceeds, the check valve 8 is opened to return the return oil to the oil tank 2 without passing through the filter 7.

In this embodiment, an example in which the oil return pipe 1 including two filter non-passage circuits 1a and one filter passage circuit 1b is formed has been described. However, a plurality of filter passage circuits 1b are provided. It is also possible to do so. As described above, the filter non-passage circuit 1a connected to the plurality of hydraulic devices is returned to the oil tank 2 as it is, and in this embodiment, one filter passage circuit 1b is filtered through the filter 7. Since the oil is recirculated to the oil tank 2 after the operation, the oil can be circulated between the oil tank 2 and the hydraulic equipment while preventing the operating oil from being contaminated.

[0012]

[Effect of the device]

 The return circuit filter structure according to the present invention is a return circuit for returning return oil from a plurality of hydraulic devices to a single oil tank via a plurality of return circuits, each of which is connected to the return circuit. Since the filter passing circuit and the filter non-passing circuit are integrally formed, and the filter base having a single return hole is attached to the oil tank through this single return hole, The effect of can be achieved.

That is, one or a small number of pipes of the return oil circuit are connected to a passage communicating with a filter provided in the filter base, and the other pipes are not connected to this filter. It does not have to connect individual pipes to the oil tank as in the conventional device, and simplifies the piping. In addition, the number of parts can be reduced with simplification of the piping, and the assembling work becomes easy. Further, since the arrangement of the pipes is simplified, the piping work can be easily performed even in a narrow space.

[0014]

[Brief description of drawings]

FIG. 1 is a front view of a return circuit using a filter base according to the present invention.

FIG. 2 is a front view showing a filter base and a filter partially cut away.

[Explanation of symbols]

1 Return Pipe 1a Filter Passing Circuit 1b Filter Passing Circuit 2 Oil Tank 3 Side Plate 3a Inlet Hole 5a, 5b Passage 5c Communication Hole 5d Reflux Hole
6 Filter mounting seat 6a Screw part 6b Inflow hole 7 Filter 7
a Filter mounting member.

Claims (1)

[Scope of utility model registration request] Claim: What is claimed is: 1. A return circuit for returning return oil from a plurality of hydraulic devices to a single oil tank via a plurality of return circuits, comprising a filter passage circuit and a filter non-passage circuit respectively connected to the return circuits. A filter circuit structure of a return circuit in which a filter base which is integrally formed with a single reflux hole is attached to an oil tank through the single reflux hole.