JPH078882Y2 - Oil tank - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Purpose of Invention] (Industrial field of application) The present invention accommodates oil supplied to and discharged from a hydraulic actuator (hydraulic motor, hydraulic cylinder, etc.) used in, for example, construction machinery. It relates to the oil tank.

(Prior Art) Oil used in hydraulic systems of construction machines is
As shown in FIG. 6, the oil that has been supplied to the hydraulic actuator (hydraulic motor, hydraulic cylinder, etc.) 14 via the oil tank 11, the pump 12 and the control valve 13 and has reached a high temperature is shown in FIG. 6 to FIG. As shown in, the oil is returned to the oil tank 11 via the return filter 15 and the oil cooler 16. A relief valve 17 is provided in parallel with the oil cooler 16. The relief valve 17 has a function of returning the oil from the return filter 15 directly to the tank 11 when the internal pressure of the oil cooler 16 is high (in the case of high viscosity due to low temperature at the time of starting, clogging, etc.).

The conventional example shown in FIGS. 6 and 7 is a circuit in the case where the number of the return filter 15 is one. The conventional example shown in FIG.
When the relief valve 17 is connected in parallel in the middle of the piping, pressure loss occurs at the merging and branching points of the piping, and when the oil temperature is low and the viscosity is high at the time of starting, it is difficult for the oil to quickly return from the return filter 15 to the tank 11. In the conventional example of FIG. 7, the circuit after the relief valve 17 is directly returned to the tank 11, but the relief valve 17 is installed in the middle of the piping.

The conventional example shown in FIG. 8 has a plurality of return filters 15.
In this case, since the filter capacity is large and the relief valve 17 is installed in the middle of the piping, the relief valve 17 having a large capacity is attached according to the filter capacity. Further, since there is a pipe merging point and a branch point between the return pipe from the return filter 15 to the tank 11 and the relief valve 17, a large pressure loss is likely to occur.

(Problems to be solved by the invention) In order to reduce such pressure loss, it is necessary to increase the pipe diameter or the relief valve capacity in accordance with the amount of oil from the return filter 15 to the oil tank 11. Good, but with mechanical design limitations. Moreover, each filter 1
5, When oil cooler 16 and relief valve 17 are connected by piping, hose, pipe, elbow, etc. are required for the pipeline components, and pressure loss in the pipeline is still liable to occur. I won't.

An object of the present invention is to reduce pressure loss in an oil return path to an oil tank and to reduce cost by simplifying the path.

[Constitution of device]

(Means for Solving the Problem) The invention of claim 1 is an oil tank for storing oil to be supplied to and discharged from a hydraulic actuator.
21 is integrally provided with a filter chamber 24.
Is provided with a return filter 27, and an oil chamber 25 for oil passing through the return filter 27 is provided below the filter chamber 24.
The oil chamber 25 is provided with a relief valve 29 and the oil chamber 25 and the tank main body are passed through the relief valve 29.
It is connected to the inside of 21.

According to the invention of claim 2, a partition 28 between the oil chamber 25 and the inside of the tank body 21 is provided.
Is provided with a relief valve 29.

(Operation) According to the invention of claim 1, when the oil returned from the hydraulic actuator enters the filter chamber 24 and is filtered by the return filter 27, it directly enters the oil chamber 25, and the oil pressure in the oil chamber 25 is reduced. When the value is high, the oil is returned from the oil chamber 25 into the tank body 21 through the relief valve 29.

According to the invention of claim 2, when the oil pressure in the oil chamber 25 is high, the partition wall
Oil is returned from the oil chamber 25 directly into the tank body 21 via the relief valve 29 of 28.

(Embodiment) Hereinafter, the present invention will be described in detail with reference to an embodiment shown in FIGS. 1 to 5.

As shown in FIG. 1, the tank body 21 is provided with a filter container.
22 is integrally provided, and a partition plate is provided inside the filter container.
23 is provided horizontally, and the partition plate 23 partitions the upper filter chamber 24 and the lower oil chamber 25. Partition board
An oil passage 26 is bored in 23, and the oil chamber 26 connects the filter chamber 24 and the oil chamber 25. A return filter 27 is provided in the filter chamber 24. A relief valve 29 is provided on a partition wall 28 between the oil chamber 25 and the tank body 21.

A pipe line 31 for guiding the oil discharged from the hydraulic actuator is connected to the filter chamber 24, and the oil chamber 25 is connected to the tank body 21 via the pipe line 32, the oil cooler 33 and the pipe line 34.
Connected to.

As shown in FIGS. 2 and 3, the filter chamber
A plurality of (three) return filters 27 are provided in parallel with 24. In addition, a connection port 35 for the conduit 31 and a connection port 36 for the conduit 32 are provided on the side surface of the filter container 22.

As shown in FIG. 4, the return filter 27 is
The filter attaching / detaching port 41 opened on the upper surface of the filter container 22 is inserted onto the opening edge of the oil passage port 26, and the filter attaching / detaching plate 42 and the compression coil spring 43 are set on the upper end of the return filter 27 to attach / detach the filter. Lid 41 on mouth 41
The return filter 27 is elastically fixed by the repulsive force of the spring 43. A rod 45 is integrally fitted to the center of the filter pressing plate 42, and
Filter bypass valve 46 slidably fitted to 45
Is a valve seat part integrally formed with the filter pressing plate 42.
The spring 48 is pressed against 47. 49 is
The spring receiving nut is integrally provided on the rod 45.

The filter bypass valve 46 is a return filter 27.
Is a valve for protecting the filter chamber 24 from an excessive internal pressure, and when the internal pressure of the filter chamber 24 becomes excessively large, the oil in the filter chamber 24 resists the spring 48 and causes the filter bypass valve 46 to open the valve seat. It pushes open from the portion 47 and enters the inner space of the return filter 27.

The relief valve 29 is shown in FIG. In this relief valve 29, a valve body 51 is screwed to the partition wall 28, a rod 53 is fitted to a central portion 52 of the valve body 51, and a valve operating portion 54 is slidably fitted to the rod 53. The valve actuating portion 54 is engaged with a valve seat 56 of the valve body 51 by a coil spring 55 mounted on the rod 53 so as to be able to come into contact with and separate from the valve seat 56. The valve body 51 is provided with a plurality of oil passage holes 57. The spring 55 is interposed between the valve operating portion 54 and the spring receiving portion 58 fitted to the rod 53 in a compressed state, and the spring receiving portion 58
Are locked by a nut 60 screwed into the threaded portion 59 of the rod 53.

Next, the operation of this embodiment will be described. In FIG. 1, the oil that has flowed into the filter chamber 24 flows through the return filter 27, from the oil passage 26 to the oil chamber 25, and then the pipeline.
After passing through 32, the oil flows out to an external oil cooler 33, is cooled by the oil cooler 33, and is then returned to the tank main body 21 via a pipe line 34.

When the internal pressure of the oil cooler 33 is high (when the oil has a low temperature and high viscosity or is clogged), the internal pressure of the oil chamber 25 may exceed the relief pressure set by the nut 60 of the relief valve 29. The oil in the oil chamber 25 is the spring 55
The valve actuating portion 54 is pushed open against the pressure and is returned directly into the tank body 21.

Even when a large-capacity valve is required as the relief valve 29, a plurality of relief valves 29 can be attached to the partition wall 28, and a small-capacity valve can be used without increasing the pipe diameter or increasing the number of pipes.

[Effect of device]

According to the invention of claim 1, the tank body is integrally provided with the filter chamber, the filter chamber is provided with the return filter, and the oil chamber of the oil passing through the return filter is defined and formed in the lower portion of the filter chamber. Since the relief valve is provided in the chamber, the piping from the return filter to the relief valve can be omitted, the pressure loss can be reduced accordingly, and the cost can be reduced by omitting the piping. Further, even when a large-capacity filter is required as a return filter, by mounting a plurality of return filters in a common filter chamber, a small-capacity filter can be used without increasing the pipe diameter or increasing the number of pipes.

According to the invention of claim 2, since the relief valve is provided in the partition wall between the oil chamber and the inside of the tank main body, the piping from the relief valve to the inside of the tank main body can be omitted, and the pressure loss can be reduced accordingly, and the piping can be reduced. The cost can be reduced by omitting it. Further, even when a large capacity valve is required as a relief valve, a plurality of relief valves can be attached to the partition wall so that a small capacity valve can be used without increasing the pipe diameter or increasing the number of pipes.

[Brief description of drawings]

FIG. 1 is a schematic view showing an embodiment of the oil tank of the present invention, FIG. 2 is a front view thereof, FIG. 3 is a plan view thereof, FIG. 4 is a sectional view of a return filter thereof, and FIG. Sectional views of the valve, FIG. 6, FIG. 7 and FIG. 8 are circuit diagrams of an oil return line for a conventional oil tank, respectively. 21 …… Tank body, 24 …… Filter chamber, 25 …… Oil chamber, 27
...... Return filter, 28 ...... Partition, 29 ...... Relief valve.

Claims (2)

[Scope of utility model registration request] In an oil tank for storing oil supplied to and discharged from a hydraulic actuator, a tank chamber is integrally provided with a filter chamber, a return filter is provided in the filter chamber, and a return filter is provided at a lower portion of the filter chamber. An oil tank characterized in that an oil chamber of the oil that has passed through is formed by partitioning, a relief valve is provided in this oil chamber, and the oil chamber and the inside of the tank body are communicated via this relief valve. 2. The oil tank according to claim 1, wherein a relief valve is provided on a partition wall between the oil chamber and the tank body.