JPH0821290B2 - Fluid pressure drive - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a drive device for converting pressure energy of a fluid into displacement, velocity, force, etc. to drive a load device, and equipment requiring high-speed operation. , For example, to a fluid pressure drive device suitable for a circuit breaker.

[Conventional technology]

Conventionally, in this type of fluid pressure drive device, for example, Japanese Patent Publication No.
As described in 48934, its main components were assembled in two parts. That is, the fluid pressure generating portion and the driving portion are connected by piping. The former are motors, pumps, tanks, filters, safety valves and other reinforcements, and the latter are control valves and actuators. By the way, the tank occupies the largest space in the device due to the large amount of fluid required, and is a space more than half that of the fluid pressure drive device.

[Problems to be solved by the invention]

The fluid pressure drive device is generally characterized by small size, large output, and high response as compared with other types of drive devices. Therefore, it is used to make the best use of its characteristics, and is used for large-scale products such as construction machines, rolling mills, and testing machines, as well as relatively small devices such as elevators and machine tools. However, in the conventional fluid pressure drive device, the fluid pressure generation unit and the drive unit are separate, and both are connected by piping. Further, the fluid pressure generating portion is provided with a large tank that occupies about half the space of the device. For this reason, even though it is said to be small, it simply occupies twice as much space because it is only a tank that stores fluid, and it is hard to say that the size has been reduced to the limit. Further, since the drive section needs work to seal the high-pressure fluid in order to perform work to the outside, some leakage of fluid from the seal section is inevitable in the current state of the art. Therefore, a device for collecting the leaked fluid up to the tank is required, and this space and cost cannot be ignored.

An object of the present invention is to provide a fluid pressure drive device which is designed to reduce the size of a tank.

[Means for solving problems]

An object of the present invention is to provide an actuator for a fluid pressure drive unit.
The actuators are stacked, and the inside is an actuator that works to the outside, and the outside is a fluid pressure tank.

[Action]

Even if there is a leak from the sliding part of the actuator, the actuator part that receives the driving force due to the high-pressure fluid is doubled, and the tank is provided outside the actuator part. Can be collected. Therefore, there is no external leakage of liquid. External dust will not enter the tank together with the leaked liquid. The most important effect is that the tank can be downsized and the entire device can be downsized.

〔Example〕

FIG. 1 is a general circuit diagram of a liquid pressure drive device to which the present invention is applied. The motor 1, the pump 2, the control valve 3, the actuator 4, the filter 5, the tank 6 and others are not shown but have the purpose. Comprised of necessary auxiliary equipment according to. 7 to 11 are flow paths for connecting these devices, and the actuator 4 is the cylinder 2
The piston 12 and the piston rod 23 drive the load 12 with the piston rod 23. The pump 2 is driven by the motor 1, sucks fluid from the tank 6 through the filter 5,
A fluid whose flow direction or flow rate is controlled by the control valve 3 is supplied to the actuator 4. In the actuator 4, the force generated by the pressure fluid is transmitted to the load 12 via the piston rod 23. When the high-pressure fluid is supplied to the channel 9 side, the load 12 is driven to the right, and conversely, when the high-pressure fluid is supplied to the channel 10 side, the load 12 is driven to the left.

FIG. 2 shows a case where the apparatus shown in FIG. 1 is realized by the method according to the present invention. The same reference numerals as those in FIG. 1 represent the same devices. FIG. 3 is a view of FIG. 2 seen from the right side.
FIG. 4 is a diagram showing a detailed cross section of the actuator portion.
The actuator 4 is made into a double cylinder, and the inner cylinder 21 is used as a cylinder and the outer cylinder 24 is used as a tank. Therefore, the inner cylinder 21 has a piston 22 and a piston rod 23, and has two fluid chambers 26 and 27, which are connected to the control valve 3 through the flow paths 9 and 10, respectively. The fluid chamber 28 of the outer cylinder 24 stores the fluid and is connected to the flow path 7, 11v filter 5, and the control valve 3. The pump 2, the motor 1, the control valve 3, the filter 5, etc. are mounted 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 volume of the piston rod 23, which is not so large. Therefore, the volume of the fluid in the tank 24 is not changed and does not become so large. It is sufficient that the tank 24 has a size that supplements it and has a slight margin. The filter 5 not only removes dust in the liquid, but also has a function of removing gas in the liquid, and the fluid sucked into the pump 2 is free of dust and gas, which causes cavitation. It is controlled and more convenient in terms of efficiency, noise and durability. FIG. 5 shows an example of a vertical arrangement of a fluid pressure drive device having the same function as in FIGS. Since it is the same as the previous figure, the detailed description is omitted.

FIG. 6 shows a case where the actuator is operated in one direction of pulling, in which the fluid chamber 26 is connected to the fluid chamber 8 through the communication hole 31, and the stopper 30 for designating the stroke end position of the piston 22 is provided. In this case, the fluid chamber 26 also plays the role of a tank like 28.

In contrast to the example of FIG. 6, FIG. 7 shows a case in which the actuator pushes and acts in one direction, and the fluid chamber 27 is connected to the fluid chamber 28 via the communication hole 31 and functions as a tank. Further, the stopper 30 specifies the stroke end of the piston 22. Seventh
The figure shows the case where the actuator is a ram type.
The ram 23, instead of the piston and piston rod, does the work to the outside.

5-8, the structure of the actuator is different,
The motor, pump, control valve, filter, etc. are the same as in FIG. In the embodiment, the example in which these devices are mounted around the actuator 4 is shown. However, it is convenient for downsizing the device and maximizing the capability,
If the arrangement of the system is unavoidable, the invention can be exerted even if the motor, pump, etc. are arranged separately from the actuator and the two are connected by piping as a measure for improvement.

FIG. 9 is a diagram showing details of the head portion of the actuator. For the inner cylinder 21, piston 22, piston rod 23,
A holding portion 34 that holds the wear ring 36, a holding portion 33 that holds the packing 35, and an end plate 32 that holds the dust seal 37 are laminated on the cylinder 21 with the piston rod 23 as the center. The outer cylinder 24 is almost coaxial with the inner cylinder 21 and has an end plate.
Fixed at 32. These holding members are fixedly connected with bolts 43, 44 and 45. The fluid chamber 28 is a tank in which fluid is stored, and its liquid level is represented by 29. Reference numeral 10 denotes a supply port or a discharge port of the pressure fluid to the fluid chamber 27.
The pressure fluid in the fluid chamber 27 is sealed by the packing 35, but if it should leak, it will be collected in the space 39 and cut off from the outside by the dust seal 37. At 42, it is connected to the fluid chamber 28 and is maintained at atmospheric pressure. Therefore, the leaked fluid from the packing 35 portion is collected in the fluid chamber 28, that is, the tank without being contaminated, and is not leaked to the outside or contaminated with dust from the outside. In addition, the fluid leaked at this time, without any other recovery means, device,
Collected in a tank.

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

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

In the embodiment of the present invention, the tank, the actuator, and the pump, the motor, the filter, and the like are integrally connected, but they may be separately provided depending on the case.
In that case, only two pipes for suction from the tank and discharge from the pump are required, and the dimensions of the fluid pressure generating portion of the motor, the pump, etc. are no different from those of the embodiment. Can be miniaturized.

〔The invention's effect〕

According to the present invention, since the actuator is made into a double cylinder and the inside is used as the actuator and the outside is used as the tank, the anch can be downsized. That is, since the volume change 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 the volume of the fluid and has a slight margin.
Moreover, since the actuator surface area can be made relatively large compared to the fluid volume, the heat radiation area is also relatively wide, and the heat radiation effect is large.

[Brief description of drawings]

FIG. 1 is a circuit diagram of a general fluid pressure drive device. FIG. 2 is a block diagram of the fluid pressure drive device of the present invention. FIG. 3 is a side view of FIG. FIG. 4 is a view showing the structure of the actuator of FIG. 5 to 8 are views showing another embodiment of the present invention. 9 and 10 are views showing the structure of the actuator head portion. 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 (3)

[Claims] 1. A fluid pressure drive device comprising a fluid pressure generating portion including a motor, a pump, a tank, etc., an actuator for driving a load, and a control valve for controlling the direction or size of the load. A double cylinder structure, which has a piston, a piston rod, etc. on its inner side and acts as a tank on the outer side, and has a packing that seals the pressure fluid in the actuator. The fluid pressure drive device is characterized in that the leaking fluid is stored in a space, the outside of which is cut off from the outside by another sealing means, and the space and the tank are connected by a flow path. 2. A fluid pressure drive device according to claim 1, wherein a motor, a pump, a filter, a control valve and the like are integrally assembled around the outer cylinder of the actuator,
A fluid pressure drive device characterized in that they are connected in a required flow path. 3. The fluid pressure drive device according to claim 1, wherein the filter arranged between the tank and the pump has a function of removing not only dust in the fluid but also gas in the fluid. A fluid pressure drive device characterized by using the provided device.