JPS63202811A - Fluid pressure drive device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a drive device that drives a load device by converting fluid pressure energy into displacement, velocity, force, etc., and is applicable to equipment that requires high-speed operation. The present invention relates to a fluid pressure drive device suitable for use in, for example, a circuit breaker.

[Conventional technology]

Conventionally, in this type of fluid pressure drive device, for example,
As described in No. 4893°4, its main components are 2
It was assembled in parts. That is, a fluid pressure generating section;
The drive unit was connected to the drive unit by piping. The former is
Motors, pumps, tanks, filters, safety valves and other auxiliary equipment, the latter including control valves and actuators. By the way, the tank occupies the largest amount of space in the device, and takes up more than half the space of the fluid pressure drive device, partly because the amount of fluid required is large.

[Problem that the invention seeks to solve]

Fluid pressure drives are generally characterized by small size, high output, and high response compared to other types of drive devices. Therefore, they are used in ways that take advantage of their characteristics, and are used in products ranging from large systems such as construction machinery, rolling mills, and testing machines to relatively small equipment such as elevators and machine tools. However, in the conventional fluid pressure drive device, the fluid pressure generating section and the driving section are separate, and the two are connected by piping. Furthermore, the fluid pressure generating section is equipped with a large tank that occupies about half the space of the device. For this reason, although it is said to be small, it occupies twice as much space just for the tank that stores the fluid, so it is hard to say that it has been miniaturized to the limit. Furthermore,
Since the drive section performs work to the outside, it necessarily requires a means for sealing high-pressure fluid, but some fluid leakage from this seal is unavoidable at the current state of the art. Therefore, a device is required to recover the leaked fluid to the tank.
This space and cost cannot be ignored.

SUMMARY OF THE INVENTION An object of the present invention is to provide a fluid pressure drive device that allows a tank to be made smaller.

[Means for solving problems]

An object of the present invention is to double the actuators of the fluid pressure drive unit, with the inner actuator serving as an actuator that performs work on the outside, and the outer part serving as a fluid pressure tank.

[Effect]

2 actuator parts that receive driving force through the action of high-pressure fluid.
By making the actuator heavier and providing a tank outside it, even if there is a leak from the sliding part of the actuator, it can be collected into the tank without being exposed to the outside air. Therefore, external leakage of liquid is eliminated. External dust will no longer enter the tank along with the leaked liquid. The most important effect is that the tank can be made smaller and the entire device can be made smaller.

〔Example〕

FIG. 1 is a general circuit diagram of a fluid pressure drive device to which the present invention is applied. Pump 2. Control valve 3. Actuator 4. Filter 5. It consists of a tank 6 and other auxiliary equipment not shown but necessary depending on the purpose. 7 to 11 are channels connecting these devices, and actuator 4
are cylinder 21, piston 22. It is composed of a piston rod 23, and the load 12 is driven by the piston rod 23. The pump 2 is driven by a motor 1, sucks fluid from a tank 6 through a filter 5, and supplies the fluid to an actuator 4, the flow direction or flow rate of which is controlled by a control valve 3. In the actuator 4, via the piston rod 23,
The force generated by the pressure fluid is transmitted to the load 12. When the high-pressure fluid is supplied to the flow path 9 side, the load 12 is driven to the right, and when it is supplied to the flow path 10 side, the load 12 is driven to the left.

FIG. 2 shows a case in which the apparatus shown in FIG. 1 is realized by the method of the present invention. The same symbols as in FIG. 1 represent the same equipment. FIG. 3 is a view of FIG. 2 from the right side. FIG. 4 is a diagram showing a detailed cross section of the actuator section. The actuator 4 has double cylinders, with the inner cylinder 21 used as a cylinder and the outer cylinder 24 used as a tank. Therefore, the inner cylinder 21 has a piston 22. There is a piston rod 23 and two fluid chambers 26, 27, each communicating with the control valve 3 by a flow path 9, 10. The fluid chamber 28 of the outer cylinder 24 stores fluid and is connected to the flow path 7. llv filter5. Connected to control valve 3. The pump 2, motor 1, control valve 3, filter 5, etc. are attached around the outer cylinder 24. When the piston 22 moves in the left-right direction, the change in the volume of the fluid chambers 26 and 27 is the same as the volume of the piston rod 23, which is not so large. Fluid volume fluctuations within the tank 24 therefore do not become too large. It is sufficient for the tank 24 to have a size that compensates for this and leaves some margin. The filter 5 has the function of not only removing dust from the liquid, but also gas from the liquid, so that the fluid sucked into the pump 2 is free of dust and gas, thereby preventing cavitation from occurring. controlled, efficiency, noise,
It is also more convenient in terms of durability. FIG. 5 shows an example of a vertical arrangement of a fluid pressure drive device having the same function as those in FIGS. 2-4. This is the same as last time, and detailed explanation will be omitted.

FIG. 6 shows a case in which the actuator performs one-way pulling operation, in which the fluid chamber 26 is connected to the fluid chamber 28 through a communication hole, and has a stopper 30 that specifies the stroke end position of the piston 22.

In this case, the fluid chamber 26 also functions as a tank like 28.

FIG. 7 shows a case in which the actuator acts in one direction of pushing, contrary to the example shown in FIG. 6, where the fluid chamber 27 is connected to the fluid chamber 28 via a communicating hole and serves as a tank. Further, the stopper 3o specifies the stroke end of the piston 22. FIG. 7 shows a case where the actuator is of a ram type, and the ram 23 performs work on the outside instead of the piston and piston rod.

Although the structure of the actuator in FIGS. 5 to 8 is different, the motor, pump, control valve, filter, etc. are the same as in FIG. 3. In the embodiment, an example was shown in which these devices were installed around the actuator 4, but this is convenient for downsizing the device and maximizing its capabilities, so it may be unavoidable due to the layout of the system. In some cases, as an improvement measure, the motor, pump, etc. may be placed in an I arrangement with the actuator, and both may be connected by piping, but the effects of the invention can still be achieved.

FIG. 9 is a diagram showing details of the head portion of the actuator. Inner cylinder 21. Piston 22. A holding part 34 holding a wear ring 36, a holding part 33 holding a packing 35, and an end plate 32 holding a dust seal 37 are stacked on the cylinder 21 with the piston rod 23 at the center. The outer cylinder 24 is fixed to the end plate 32 substantially coaxially with the inner cylinder 21. These holding members are fixedly connected by bolts 43, 44, 45. The fluid chamber 28 is a tank in which fluid is stored, and the liquid level is represented by 29. 10 is fluid chamber 2
7 is a supply or discharge port for pressure fluid. Although the pressure fluid in the fluid chamber 27 is sealed with a gasket 35,
In case of any leakage, it accumulates in the space 39, which is cut off from the outside by the dust seal 37, and this space is connected to the chamber 41 through the flow path 4o and further to the fluid chamber 28 through the flow path 42, and is maintained at atmospheric pressure. Therefore, the fluid leaking from the gasket 35 is collected into the fluid chamber 28, ie, the tank, without any contamination, and is not leaked to the outside or contaminated with external dust. Further, the fluid leaked at this time is collected into the tank without any separate collection means or device.

FIG. 10 is the same as FIG. 9, but the packing holding part 33
The packing and the wear ring holding part 34 are integrated, and the packing and the wear ring are held by the same member 33, and the structure is such that they are collected directly into the tank through the flow path 42 without the chamber 41 shown in FIG.

At this time, if the filter 3 has the function of not only removing dust contained in the fluid but also removing gas contained in the liquid, the feature of the present invention, that is, the tank internal volume can be further reduced, and the fluid Maximizes the performance of the drive unit. By removing air bubbles, it is possible to suppress the occurrence of cavitation and improve responsiveness.

In the embodiment of the present invention, a case has been shown in which a pump, a motor, a filter, etc. are integrally connected to a tank and an actuator, but these may be placed separately depending on the case. In that case, only two pipes are required, one for suction from the tank and one for discharge from the pump, and the dimensions of the fluid pressure generating parts such as the motor and pump are the same as in the embodiment. Can be made smaller.

〔Effect of the invention〕

According to the present invention, the actuator is made into a double cylinder so that the inner side is used as the actuator and the outer side is used as the tank, so it is possible to downsize the tank. That is, since the change in volume of the fluid in the actuator due to the operation of the actuator is small, the tank capacity may be a volume that compensates for the change in volume of the fluid and provides some margin.

Moreover, since the actuator surface area can be relatively large compared to the fluid volume, the heat radiation area is also relatively large, and the heat radiation effect is increased.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram of a general fluid pressure drive device. FIG. 2 is a configuration diagram of the fluid pressure drive device of the present invention. FIG. 3 is a side view of FIG. 2. FIG. 4 is a diagram showing the structure of the actuator shown in FIG. 2. 5 to 8 are diagrams showing other embodiments of the present invention. 9 and 1o are diagrams showing the structure of the actuator head section. 1...Motor, 2...Pump, 3...Control valve, 4
...actuator, 6...tank 7-11...
Flow path, 12...Load, 21...Inner cylinder, 22...Piston, 23...Piston rod, 24...Outer cylinder

Claims (1)

[Scope of Claims] 1. A fluid pressure drive device consisting of a fluid pressure generating section composed of a motor, a pump, a tank, etc., an actuator that drives a load, and a control valve that controls its direction or magnitude. , a fluid pressure drive device characterized in that the actuator has a double-tube structure, the inner side of which acts as an actuator having a piston, piston rod, etc., and the outer side of which acts as a tank. . 2. In the fluid pressure drive device according to claim 1, the leakage fluid from the packing that seals the pressure fluid in the actuator is collected in a space, and the outside thereof is isolated from the outside world by a separate sealing means. A fluid pressure drive device characterized in that this space and a tank are connected by a flow path. 3. In the fluid pressure drive device according to claim 1, a motor, a pump, a filter, a control valve, etc. are integrally assembled around the outer cylinder of the actuator, and they are connected through necessary flow paths. Characteristic fluid pressure drive device. 4. In the fluid pressure drive device according to claim 1, the filter disposed between the tank and the pump is provided with a function capable of removing gas in the fluid in addition to dust in the fluid. A fluid pressure drive device characterized by using.