JPS5817923Y2 - air hydraulic cylinder device - Google Patents

Description

[Detailed Description of the Invention] The present invention is a two-stage pressurized pneumatic-hydraulic cylinder device using a pneumatic-hydraulic conversion method, in particular, an output hydraulic cylinder in which an output piston is advanced by hydraulic pressure and retracted by pneumatic pressure.
are arranged concentrically outside this output hydraulic cylinder,
A pre-pressure hydraulic cylinder that converts air pressure into hydraulic pressure and presses the resulting oil into the output hydraulic cylinder through an oil passage to advance the output piston, and a push-in body integrated with the pre-pressure hydraulic cylinder that advances the pressure booster piston with air pressure. The present invention relates to a pneumatic hydraulic cylinder device comprising a pressure increasing pneumatic cylinder which blocks the oil passage and enters the output hydraulic cylinder to further advance the output piston.

Conventionally, as this type of pneumatic hydraulic cylinder device, the
As is known from Japanese Utility Model Publication No. 70 and Japanese Utility Model Application Publication No. 55-80501, etc., within the annular space between the output hydraulic cylinder and the preload cylinder, this annular space is divided into a pneumatic chamber and a hydraulic chamber. A partitioning annular piston is slidably fitted, and compressed air is sent into the pneumatic chamber to push the annular piston toward the hydraulic chamber, thereby transferring the oil in the hydraulic chamber into the output hydraulic cylinder. There are known products that can be press-fitted into.

However, with this conventional type, if the output and preload hydraulic cylinders, which have a double cylinder structure, are combined even slightly eccentrically, the annular piston will not slide smoothly, and this will be compensated for. Therefore, if the fitting gap of the annular piston is made large, the gasket attached to the piston receives an uneven load, resulting in leakage of compressed air and oil.

Furthermore, since the outer circumferential surface of the output hydraulic cylinder and the inner circumferential surface of the preload hydraulic cylinder require hard plating treatment such as hard chrome plating, it also has the disadvantage of being expensive.

The present invention is designed to easily overcome these conventional drawbacks, and its feature is that a cylindrical diaphragm is used instead of an annular piston as a member that divides the annular space into a pneumatic chamber and a hydraulic chamber. It has been used.

That is, in the present invention, an expandable cylindrical diaphragm is disposed within an annular space, concentrically dividing the annular space into two inner and outer chambers, and one of these two inner and outer chambers is designated as a pneumatic chamber, The other side is a hydraulic chamber, and the oil in the hydraulic chamber can be press-fitted into the output hydraulic cylinder through an oil passage.

The present invention will now be described in detail with reference to the illustrated embodiments.

This pneumatic hydraulic cylinder device is made by combining three cylinders: an output hydraulic cylinder A, a preload hydraulic cylinder B, and a pressure increasing pneumatic cylinder C as follows.

That is, the output hydraulic cylinder A and the preload hydraulic cylinder B are arranged concentrically with the former's tube 1 on the inside and the latter's tube 2 on the outside, and their front and rear end openings are connected to a common cylinder cover 3, 4. It has a closed double cylinder structure.

The residual pressure increasing pneumatic cylinder C is directly connected to the two hydraulic cylinders A and B with the rear end opening of the tube 5 closed by the cylinder cover 6 and the front end opening closed by the cylinder cover 4.

The output hydraulic cylinder A has an output piston 7 slidably fitted in its tube 1, and a hydraulic fluid is pressurized into a chamber in the tube 1 on the rear side of the output piston γ. By moving the output piston γ forward, the piston rod 8 can take out the output to the outside, and the port 9 provided in the cylinder cover 3
By feeding compressed air into the chamber in front of the output piston 7, the output piston 7 can be moved backward.

In addition, the preload hydraulic cylinder B has an annular space between its tube 2 and the tube 1 of the output hydraulic cylinder A.
A bellows-shaped cylindrical diaphragm 10 made of rubber or the like and capable of expanding and contracting is disposed, and its annular space is concentrically divided into two chambers, an inner chamber and an outer chamber. The outer chamber that meets the pneumatic chamber 11° is a hydraulic chamber 12.

The diaphragm 10 has both ends attached to the cylinder covers 3 and 4.
They are fixed respectively.

The diaphragm 10 may be a long corrugated tube with annular protrusions 13 formed on its outer circumferential surface, as shown in FIG. 2 with only two parts enlarged, or as shown in FIG. 3. A long corrugated pipe with an annular protrusion 13 formed on the inner circumferential surface as shown in FIG.
The corrugated pipe formed on the same inner and outer circumferential surfaces is attached to the cylinder cover 3.
It is constructed by cutting the protrusions 13 at the positions of the protrusions 13 and 4 according to the distance between the protrusions 13 and 4, and
By locking the cylinder covers 3 and 13 to the cylinder covers 3 and 4, respectively, the cylinder covers 3 and 4 can be provided at low cost and can be easily secured to both the cylinder covers 3 and 4.

The preload hydraulic cylinder B feeds compressed air into the pneumatic chamber 11 through the port 9' to expand the diaphragm 10, thereby discharging the oil in the hydraulic chamber 12 into the oil passage provided in the cylinder cover 4. 14 into the output hydraulic cylinder A (a chamber on the rear side of the output piston 7), thereby making it possible to move the output piston 7 forward.

Further, the pressure increasing pneumatic cylinder C has a pressure increasing piston 15 having a diameter larger than the output piston 7 slidably fitted in the tube 5 thereof.

A port 1 provided in the cylinder cover 6 is located inside the tube 5 and in the chamber on the rear side of the pressure booster piston 15.
By feeding compressed air through the cylinder cover 6 and moving the pressure booster piston 15 forward, the piston rod IT, which is a push-in body with the pressure booster piston 15 projecting therethrough, passes through the through hole 18 provided in the cylinder cover 4. It is designed to enter the output cylinder A (the chamber on the rear side of the output piston 7) and move the output piston 7 forward, and the pressure booster piston 15 is inserted through the port 19 provided in the cylinder cover 4. By feeding compressed air into the front chamber of the pump, the pressure increasing piston 15 can be moved back.

The through hole 18 communicates with the oil passage 14, and when the piston rod 17 passes through the through hole 18 as described above, the oil passage 14 is thereby blocked.

The output piston T is provided with a horizontal hole 20 into which oil enters.

Then, compressed air is fed into the pneumatic chamber 11 of the preload hydraulic cylinder B via the switching valve (5-way valve) 21 to expand the diaphragm 10, and the oil in the hydraulic chamber 12 is outputted via the oil passage 14. After moving the output piston T forward by press-fitting it into the hydraulic cylinder A, another switching valve (3-way valve) 2
When compressed air is fed into the port 16 through the piston 2 to advance the pressure boosting piston 15 and the piston rod 17 is thrust into the output hydraulic cylinder A, the output piston 7 can be advanced with even stronger pressure.

Furthermore, if the switching valve 21 is switched to simultaneously feed compressed air into the ports 9 and 19, the output piston 7 and the pressure increase piston 15 can be moved backward at the same time.

By the way, if the output hydraulic cylinder A or the preload hydraulic cylinder B is pressed and oil leaks, the length of the forward movement of the output piston 7 becomes shorter and the output decreases.

Therefore, this pneumatic hydraulic cylinder device is designed to automatically replenish oil by effectively utilizing the air pressure for retracting the output piston 7.

That is, the out port 23 provided in the cylinder cover 3 is connected via piping to the replenishment oil tank E via a pressure reducing valve, and the output piston 7 is placed in a chamber in the output hydraulic cylinder A on the front side of the output piston 7. When compressed air is supplied to retreat the oil tank, the compressed air is depressurized and simultaneously supplied into the oil tank B, and the oil tank E and the oil passage 14 are connected through a check valve F. Piping is connected, and oil flows from the oil tank E into the output hydraulic cylinder A or the preload hydraulic cylinder B, but the reverse flow is prevented by the check valve F.

Therefore, low air pressure is applied inside the oil tank B during the backward stroke of the output piston 7, so when the output piston 7 reaches the rear stroke end, the oil in the oil tank B is transferred to the hydraulic cylinder. It is automatically replenished to fill up the amount that leaks into A or hydraulic cylinder B.

If excessive oil flows into hydraulic cylinder A or hydraulic cylinder B due to incorrect operation of the empty hydraulic cylinder device or sudden stop of the compressed air supply source,
Push the manual operator 24 on the check valve F to open the pawl valve body 2.
By forcibly opening 5, the oil in the hydraulic cylinder A or B can flow back into the oil tank B.

Furthermore, to replenish oil into oil tank B from the outside,
This is done by closing the stop valve 26 to cut off the supply of compressed air, and then opening the stopper 2T.

In addition, in the above embodiment, the preload oil pressure cylinder B
In the above, the inside of the two internal and external chambers divided by the diaphragm 10 was used as the pneumatic chamber 11 and the outside as the hydraulic chamber 12, but conversely, the inside may be used as the hydraulic chamber and the outside as the pneumatic chamber.

As is clear from the above description, the pneumatic hydraulic cylinder device of the present invention concentrically divides the annular space between the output hydraulic cylinder and the preload hydraulic cylinder into two chambers: the inner and outer chambers. An expandable cylindrical diaphragm is installed, and one of these two inner and outer chambers is a pneumatic chamber,
The other side is a hydraulic chamber, and the oil in the hydraulic chamber can be press-fitted into the output hydraulic cylinder through an oil passage.

Therefore, according to the present invention, the pneumatic chamber and the hydraulic chamber can be partitioned airtightly and liquid-tightly by the cylindrical diaphragm, unlike conventional devices in which an annular piston is slidably fitted in the annular space. In other cases, the output and preload hydraulic cylinders are eccentric and the annular piston does not slide smoothly, or the gasket attached to the piston receives an uneven load, causing leakage of compressed air and oil. There are no problems at all, and since there is no need to perform hard plating on the outer circumferential surface of the output hydraulic cylinder and the inner circumferential surface of the preload hydraulic cylinder, it can be provided at low cost.

[Brief explanation of the drawing]

Figure 1 is an exploded view showing an embodiment of the present invention, Figures 2 and 3 are
Each figure is an enlarged cross-sectional view of a portion of the tube with corrugations forming the diaphragm. 7... Output piston, A... Output hydraulic cylinder,
14... Oil passage, B... Hydraulic cylinder for preload, 15
. . . Pressure increasing piston, 17 . . . Piston rod serving as a pushing body, C . . . Pressure increasing pneumatic cylinder, 10 .

Claims (1)

[Scope of utility model registration request] There is an output hydraulic cylinder that advances the output piston with hydraulic pressure and moves it backward with air pressure, and an output hydraulic cylinder that is arranged concentrically outside of this output hydraulic cylinder, converts the air pressure into hydraulic pressure, and sends the oil through the oil passage. A preload hydraulic cylinder press-fits into the output hydraulic cylinder to advance the output piston, and a push-in body integrated with the pressure booster piston that advances the pressure increase piston using air pressure, while blocking the oil passage. A pneumatic-hydraulic cylinder device comprising a pressure increasing pneumatic cylinder that plunges into the output piston and further advances the output piston, extends the annular space inside and outside the annular space between the output hydraulic cylinder and the preload hydraulic cylinder. An expandable cylindrical diaphragm partitioned concentrically into two chambers is arranged, and one of these two chambers (outside and outside) is used as a pneumatic chamber and the other as a hydraulic chamber, and the oil in the hydraulic chamber is passed through the oil passage. A pneumatic hydraulic cylinder device characterized in that it can be press-fitted into the output hydraulic cylinder.