JPH0236802B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention is directed to a double-acting hydraulic cylinder (hereinafter referred to as a , simply referred to as a hydraulic cylinder).

This type of drive device is generally called an air-hydraulic drive device, and because it combines the advantages of pneumatics and hydraulics,
Attention has been paid.

[Prior art and its problems]

By the way, in conventionally proposed pneumatic-hydraulic drive devices, an expensive pneumatic-hydraulic converter is provided to obtain pressure oil for moving one hydraulic cylinder forward, and an expensive air-hydraulic converter is provided to obtain pressure oil for moving the same hydraulic cylinder backward. Another air-oil converter is installed to obtain the oil, which not only has the disadvantage of high costs, but also has the disadvantage that it is inevitable that the device will be larger and that it is difficult to secure installation space. . Furthermore, in the conventional device, the air-oil converter and the reservoir are provided separately, which not only requires connecting piping but also requires a large occupied floor space.

[Means for solving problems]

The present invention has been made to solve the above-mentioned problems, and includes a casing having a discharge port and a suction port, and a drive device fitted in the casing so as to be able to reciprocate and move the discharge and suction ports within the casing. a plunger partitioned into an oil chamber in which a port opens and an empty chamber connected to an air pressure source; the oil chamber is configured to open at least one double-acting hydraulic cylinder when the plunger is pushed toward the oil chamber; A single air-oil converter having a discharge capacity sufficient to discharge hydraulic oil for one reciprocation, and an inlet integrally provided on the outer periphery of the oil chamber in this air-oil converter and connected to a return oil path. and an annular reservoir having a volume substantially equal to or larger than the discharge volume of the oil chamber of the air-oil converter, having an outflow port connected to the port and the suction port through a communication passage, an air breather in an upper portion, and a discharge volume of the oil chamber of the air-oil converter. , disposed within the communication path connecting the outflow port of the reservoir and the suction port of the air-oil converter, allowing the flow of hydraulic oil to the suction port and blocking the flow of hydraulic oil to the reservoir. a check valve that connects the cavity to a pneumatic source in order to allow the plunger to move forward toward the oil chamber in a first position, and in a second position to allow the plunger to move backward; a first switching valve that connects the valve to the atmosphere; and, while the first switching valve is held at the first position, the supply oil passage and the return oil passage that are connected to the discharge port, and the double-acting hydraulic pressure. The configuration includes a second switching valve that switches the connection between both oil chambers of the cylinder.

[Action/effect of the invention]

In the drive device according to the present invention configured as described above, air pressure can be supplied to the empty chamber by the first switching valve, and the plunger can be directed toward the oil chamber by the air pressure. Pressure oil sufficient to make at least one double-acting hydraulic cylinder reciprocate one time can be discharged from the oil chamber into the supply oil passage, and the same pressure oil can be transferred to the supply oil passage by the second switching valve. It can be supplied to a dynamic hydraulic cylinder, and can be returned from the hydraulic cylinder to a return oil path.
The hydraulic cylinder can be reciprocated at least once in a short time without waiting time. For this reason, not only can the operating efficiency of the hydraulic cylinder be improved, but also a single air-hydraulic converter is required to reciprocate at least one double-acting hydraulic cylinder, which reduces the size of the device. It is possible to achieve this goal and also to reduce costs.

Further, in the drive device according to the present invention, a recirculating reservoir is adopted as the reservoir, which is integrally provided on the outer periphery of the oil chamber in the air-oil converter and communicates with the oil chamber through a communication passage with a check valve interposed therebetween. Therefore, piping between the air-oil converter and the reservoir can be eliminated, making piping work easier, and the occupied floor area can be reduced, leading to space savings.

〔Example〕

Embodiments of the present invention will be described below based on the drawings. FIG. 1 shows the basic circuit for operating one hydraulic cylinder by means of a drive device according to the invention. In this FIG. 1, an air-oil converter 10
and the reservoir 41 are integrally formed. teeth,
The discharge port 11a and the suction port 11b are always open and the oil chamber Ro is filled with hydraulic oil, and the port 11c
An annular cavity A1 that is always open and a port 11d
A vacant room A2 is formed which is always open. The empty chamber A1 is connected to the electromagnetic switching valve 20 via an air passage 21 connected to the port 11c, and the empty chamber A2
is connected to the electromagnetic switching valve 20 via an air passage 22 connected to the port 11d. Solenoid switching valve 2
0 is a two-position switching valve, which connects the air passage 21 to the compressed air source 23 and the air passage 22 to a silencer 24 communicating with the atmosphere in the illustrated position where the solenoid 20a is inactive; solenoid 2
The air flow path 21 is in the position when 0a is activated.
is connected to a silencer 24 and the air flow path 22 is connected to a compressed air source 23.

The oil chamber Ro accommodates enough hydraulic oil to make the hydraulic cylinder 60 reciprocate once, and the oil chamber Ro contains enough hydraulic oil to make one reciprocation of the hydraulic cylinder 60.
The electromagnetic switching valve 50 is connected to the
It is connected to the. The supply oil passage 30 is equipped with a check valve 31 that allows hydraulic oil to be discharged from the oil chamber Ro, and a pressure gauge 33 is provided through a stopper valve 32.
is installed. Further, the oil chamber Ro communicates with the outflow port 41b of the reservoir 41 through a communication passage 43 which is provided with a check valve 42 that allows the suction of hydraulic oil at the suction port 11b. The reservoir 41 is integrally provided around the outer periphery of the oil chamber Ro, has an annular shape, and has a capacity that is substantially the same as or larger than the discharge capacity of the oil chamber Ro.
Further, the reservoir 41 has an air breather 41a in its upper part and an inflow port 41c in its lower part.
c is connected to an electromagnetic switching valve 50 via a return oil passage 40.

The electromagnetic switching valve 50 is a three-position switching valve that switches the piston 61 of the hydraulic cylinder 60 between stop, downward movement, and upward movement, and in the illustrated position where both solenoids 50a and 50b are inactive, the supply oil passage 30 and the return oil passage are closed. 40. Cut off all connections between the oil passage 70 connected to the illustrated upper oil chamber 62 of the hydraulic cylinder 60 and the oil passage 80 connected to the illustrated lower oil chamber 63 of the hydraulic cylinder 60, and supply the oil at the position when the solenoid 50a was activated. The oil passage 30 is connected to the oil passage 70, the return oil passage 40 is connected to the oil passage 80, and the supply oil passage 30 is connected to the oil passage 80 at the position when the solenoid 50b is activated, and the return oil passage 40 is connected to the oil passage 80. 70. The oil passage 70 is equipped with a speed controller (flow rate control valve with a check valve) 71, and the oil passage 80 is equipped with check valves 81, 82, a speed controller 83 and a speed controller 84 with normally open deceleration valves. There is.

In this embodiment configured as described above, when the solenoid 20a of the switching valve 20 is operated, compressed air flows from the compressed air source 23 into the empty space A2 through the air passage 22 and the port 11d, and at the same time, the air flows into the empty space A2. The compressed air in A1 is transferred to port 11c, air flow path 21
and exhaust into the atmosphere through the muffler 24, and the plunger 12 is pressed toward the oil chamber Ro. The pressing force at this time is increased in accordance with the pressure receiving area ratio of the plunger 12 and is applied to the hydraulic oil in the oil chamber Ro.
In this state, the solenoid 50 of the switching valve 50
When actuating a, the supply oil passage 30 is connected to the oil passage 70 and the return oil passage 40 is connected to the oil passage 80,
The plunger 12 is moved upward toward the oil chamber Ro by the compressed air in the chamber A2, and the hydraulic oil in the oil chamber Ro is prevented from flowing to the reservoir 41 by the check valve 42, and the oil supply path 30 and oil through the passage 70 into the illustrated upper oil chamber 62 of the hydraulic cylinder 60 and at the same time into the illustrated lower oil chamber 63 of the hydraulic cylinder 60.
The hydraulic oil inside flows into the reservoir 41 through the oil passage 80 and the return oil passage 40, and the piston 61 of the hydraulic cylinder 60 is moved downward (forward movement) by the pressure oil supplied into the upper oil chamber 62 in the figure. be done. This piston 6
During the downward movement of the piston 61, the flow of the hydraulic oil is mainly controlled by the speed controllers 83 and 84, and the downward movement of the piston 61 is controlled. This operation continues while the upper end of the plunger 12 moves upward to the position indicated by the dashed line in the figure. When the upper end of the plunger 12 moves upward to the position indicated by the chain line in the figure, the piston 61 of the hydraulic cylinder 60 moves to the lower end. It reaches the stop position and stops, and at the same time the plunger 12 stops.

Next, when the solenoid 50a of the switching valve 50 is deactivated and the solenoid 50b is activated, the supply oil passage 30 is connected to the oil passage 80, the return oil passage 40 is connected to the oil passage 70, and the plunger 12
is again moved upward toward the oil chamber Ro by the compressed air in the empty chamber A2, and the hydraulic oil in the oil chamber Ro is prevented from flowing to the reservoir 41 by the check valve 42.
Further, the hydraulic oil flows through the supply oil passage 30 and the oil passage 80 into the illustrated lower oil chamber 63 of the hydraulic cylinder 60, and at the same time, the hydraulic oil in the illustrated upper oil chamber 62 of the hydraulic cylinder 60 flows into the illustrated oil passage 70 and the return oil passage 40. The piston 61 of the hydraulic cylinder 60 is moved upward (backwards) by the pressure oil supplied into the lower oil chamber 63 shown in the figure. When the piston 61 moves upward, the flow of the hydraulic oil is mainly controlled by the speed controller 71, and the upward movement of the piston 61 is controlled. This operation continues while the upper end of the plunger 12 moves upward to the position indicated by the two-dot chain line in the figure. When the upper end of the plunger 12 moves upward to the position indicated by the two-dot chain line in the figure, the hydraulic cylinder 60
The piston 61 reaches the upper end stop position (original position in the figure) and stops, and at the same time the plunger 12 stops.

After that, when the solenoid 50b of the switching valve 50 is deactivated and the solenoid 20a of the switching valve 20 is deactivated, the supply oil path 30, the return oil path 40, and the oil path 7
0 and the oil line 80 are disconnected, and the compressed air source 23
Compressed air flows into the cavity A1 through the air passage 21 and the port 11c, and at the same time compressed air in the cavity A2 is discharged into the atmosphere through the port 11d, the air passage 22 and the muffler 24, and the plunger 12
is moved downward by the compressed air in the chamber A1, and at the same time, the hydraulic oil in the reservoir 41 is sucked into the oil chamber Ro through the check valve 42, resulting in the state shown in the figure.

As can be understood from the above explanation, in this embodiment, the hydraulic cylinder 60 is heated in a short time without waiting time by the pressure oil obtained by the upward movement of the plunger 12 in the oil chamber Ro of the air-oil converter 10. Since the hydraulic cylinder 60 can be reciprocated once, it goes without saying that the operating efficiency of the hydraulic cylinder 60 can be increased.
It is not necessary to provide two air-oil converters as in the past, and the device can be made smaller and cost can be reduced. In addition, by reducing the number of air-oil converters by half compared to the conventional one, the exhaust noise generated when compressed air is discharged into the atmosphere from the vacant rooms A1 and A2 is halved, improving the working environment. can. Further, in the above embodiment, since the air-oil converter 10 and the reservoir 41 are integrated,
Not only can piping between the air-oil converter 10 and the reservoir 41 be eliminated, making piping work easier, but also space can be saved by reducing the occupied floor area. .

In addition, in the above embodiment, the empty chamber A1 and the oil chamber
An annular groove 15 is provided between a pair of O rings 13 and 14 for sealing between Ro.
communicates with the reservoir 41 through the communication hole 16. Therefore, even if compressed air passes through the lower O-ring 14 from the cavity A1, this compressed air enters the reservoir 41 through the groove 15 and the communication hole 16, and flows out into the atmosphere from the air breather 41a. Therefore, compressed air does not flow into the oil chamber Ro, and problems associated with air flowing into the hydraulic oil are prevented. Further, even if pressure oil passes through the upper O-ring 13 from the oil chamber Ro, this pressure oil enters the reservoir 41 through the groove 15 and the communication hole 16, and does not enter the empty chamber A1.

Note that when implementing the present invention, the plunger 12
If the amount of hydraulic oil discharged from the oil chamber Ro by the upward movement and the hydraulic oil storage capacity of the reservoir 41 are doubled, the hydraulic cylinder 60 can be made to reciprocate twice by the pressure oil obtained by the upward movement of the plunger 12. Of course, the two hydraulic cylinders 60, 160 can each be reciprocated once as shown in FIG. In the circuit shown in FIG. 2, from the switching valve 50 of the above embodiment to the hydraulic cylinder 6.
A circuit having the same configuration as the circuit leading to 0 (corresponding members are given similar symbols) is connected to both oil passages 30 and 4.
0 in parallel. For this reason,
In this embodiment, each solenoid 50a, 50b, 150a, 150 of the switching valves 50 and 150
Solenoid 2 of switching valve 20
By appropriately setting the operation timing of 0a, the operation timings of both hydraulic cylinders 60 and 160 can of course be made to be the same time, but also can be made to be different.

Further, in the above embodiment, a pressure-increasing type air-oil converter 10 was adopted as the air-oil converter that intermittently converts compressed air pressure into hydraulic pressure, but when implementing the present invention, as shown in FIG. It is also possible to employ the air-oil converter 110 shown. This air-oil converter 11
0, the upward movement of the plunger 112 is made by compressed air, and the downward movement of the plunger 112 is made by the compression coil spring 119. Also,
In the above embodiment, the switching valves 50 and 150 are used to connect and disconnect the supply oil passage 30 and the oil passages 70 and 170 or the oil passages 80 and 180, and also to connect the return oil passage 4
0 and the oil passages 80, 180 or the oil passages 70, 170, however, when implementing the present invention, the supply oil passage 30 and the oil passages 70, 170 or the oil passages are 80 and 180, and the return oil path 40 is switched on and off by the second two-position switching valve.
It is also possible to implement this by connecting and disconnecting the oil passages 80, 180 or the oil passages 70, 170.

[Brief explanation of drawings]

Fig. 1 is a basic circuit diagram for operating one hydraulic cylinder by the drive device according to the present invention;
The figure is a circuit diagram for operating two hydraulic cylinders by the drive device according to the present invention, and FIG. 3 is a schematic configuration diagram of an air-hydraulic converter that can be employed in carrying out the present invention. Explanation of symbols, 10...Air-oil converter, 11...Casing, 11a...Discharge port, 11b...Suction port, 12...Plunger, 20...Solenoid switching valve (first switching valve), 30... Supply oil line, 40...
...Return oil path, 41...Reservoir, 41a...Air breather, 41b...Outflow port, 41c...Inflow port, 42...Check valve, 43...Communication path, 50...Solenoid switching valve (second switching valve) ), 60...
...Hydraulic cylinder, 62...Upper oil chamber, 63...Lower oil chamber, Ro...Oil chamber of air-oil converter, A2...Empty chamber.

Claims (1)

[Claims] 1. A casing having discharge and suction ports;
A plunger is reciprocatably fitted into the casing and divides the inside of the casing into an oil chamber in which the discharge and suction ports open and a cavity connected to an air pressure source, and the oil chamber is provided with a plunger in which the plunger is connected. a single pneumatic-hydraulic converter having a discharge capacity sufficient to discharge hydraulic fluid enough to make at least one double-acting hydraulic cylinder reciprocate once when pushed toward the same oil chamber; The oil chamber has an inflow port connected to the return oil path and an outflow port connected to the suction port through a communication path, which is integrally provided on the outer periphery of the oil chamber, and includes an air breather in an upper portion of the air-oil converter. an annular reservoir having a capacity that is substantially the same as or larger than the discharge capacity of the oil chamber; and an annular reservoir disposed within the communication passage connecting the outflow port of the reservoir and the suction port of the air-oil converter; a check valve that allows flow of hydraulic oil to the port and blocks the flow of hydraulic oil to the reservoir; and in a first position, uses the hollow chamber as a pneumatic pressure source to move the plunger forward toward the oil chamber. a first switching valve that connects the empty chamber to the atmosphere in a second position to enable backward movement of the plunger; and a first switching valve that is held in the first position; A drive device for a double-acting hydraulic cylinder, comprising a second switching valve that switches connections between the supply oil path and the return oil path connected to the discharge port and both oil chambers of the double-acting hydraulic cylinder.