JPH022965Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] The present invention is a double-acting actuator that uses air pressure and requires a large output in the drive stroke but does not require a large output in the return stroke. (referred to as double-acting actuator).

[Prior Art] In a conventional cylinder drive system driven by pneumatic pressure, compressed air from a high-pressure air source is supplied to the cylinder via a directional control valve to drive the cylinder, and the cylinder is driven or returned. The air discharged from the cylinder is discharged into the atmosphere via the directional control valve.

In the above-mentioned conventional cylinder drive system, the air discharged from the cylinder as the cylinder is driven and returned has pressure, that is, a large amount of energy, so it is problematic from an energy saving perspective to release it directly into the atmosphere. be.

However, rather than simply collecting and storing the air discharged from a cylinder in an accumulator and using it as an air source for another device, using it to power the cylinder requires no equipment and allows for more effective use of energy. It was considered that this air could be used as return power for the cylinder.

In this case, if the actuator is of the drive output type, the drive stroke driven by high-pressure air from the high-pressure air source will have no problem since the low-pressure return side air will be exhausted, but the return stroke using the air pressure of the accumulator will not cause any problems. However, if the drive side pressure chamber is communicated with the accumulator in order to recover high pressure air, the air pressure on the drive side and the return side become the same, which has the disadvantage of interfering with the return of the actuator.

[Problems to be solved by the invention] The invention collects and accumulates a part of the exhaust gas discharged from the drive pressure chamber of the drive output type double-acting actuator in an accumulator, and uses it as return power for the actuator. Therefore, in order to utilize the energy effectively, the problem to be solved is to prevent the exhaust gas collected and accumulated in the accumulator from becoming a hindrance when the drive output type double-acting actuator returns.

[Means for Solving the Problems] The present invention provides a method for controlling a switching valve that controls the drive of a drive output type double-acting actuator that includes a drive side pressure chamber and a return side pressure chamber, in a first switching position. The drive-side pressure chamber and the high-pressure air source are communicated with each other, and the return-side pressure chamber and the exhaust inlet port of the recovery valve are communicated with each other, and in the second switching position, the drive-side pressure chamber, the exhaust inlet port, and the return valve are communicated with each other. The recovery valve is configured by a switching valve that communicates between the mold pressure chamber and the accumulator, and the recovery valve is connected to three ports: the exhaust inlet port, the recovery port connected to the accumulator, and the discharge port open to the atmosphere, and the exhaust pressure and the accumulator pressure. While the pressure difference between the exhaust pressure and the accumulator pressure is large, the inlet port is communicated with the recovery port, and when the pressure difference between the exhaust pressure and the accumulator pressure becomes small, the exhaust inlet port is automatically communicated with the discharge port. The above-mentioned problem is solved by the above-mentioned switching mechanism.

[Function] When the switching valve is in the first switching position, high pressure air from the high pressure air source flows into the drive side pressure chamber to drive the drive output type double acting actuator, and the exhaust from the return side pressure chamber is Since the low-pressure gas recovered in the accumulator is used, it is discharged to the atmosphere from the discharge port of the recovery valve. When the switching valve is switched to the second switching position, the high pressure air in the drive side pressure chamber flows into the accumulator through the recovery valve and is recovered and accumulated. Accordingly, when the pressure of the high pressure air in the drive side pressure chamber decreases, the inlet port of the recovery valve communicates with the exhaust port and the exhaust air in the drive side pressure chamber is discharged to the atmosphere, so that the accumulated air from the accumulator is Then, the double-acting actuator returns. The operation of the recovery valve prevents the pressure of the exhaust gas recovered by the accumulator from being applied to the drive-side pressure chamber and interfering with the return of the actuator.

[Example] Hereinafter, an example of the present invention will be described in detail based on the drawings. In FIG. 3 and a return side pressure chamber 4, and 5 is a switching valve for controlling the drive of the double-acting cylinder device 1. configured. The switching valve 5
is in the first switching position in the energized state,
The head side flow path 6 leading to the drive side pressure chamber 3 and the air supply flow path 8 leading to the high pressure air source 7 are communicated, and the rod side flow path 9 leading to the return side pressure chamber 4 is communicated with each other.
and the exhaust flow path 11 leading to the inlet port 10a of the recovery valve 10, respectively, and in the illustrated second switching position in the non-energized state, the head side flow path 6 and the exhaust flow path 11 are communicated with each other. , the rod side flow path 9 and the accumulator 12
The reflux passages 13 communicating with each other are configured to communicate with each other.

The capacity and form of the accumulator 12 can be selected depending on the scale of the cylinder drive system, etc., and an adjustment mechanism such as a variable volume type can be attached as necessary.

The recovery valve 10 is connected to the accumulator 12 via a recovery flow path 14 in addition to the inlet port 10a.
3 ports, the recovery port 10b that leads to the atmosphere, and the exhaust port 10c that is open to the atmosphere, and the inlet port 1 while there is a large pressure difference between the exhaust pressure and the accumulator pressure.
0a to the recovery port 10b, and automatically switches the inlet port 10a to the discharge port 10c when the exhaust pressure decreases and the pressure difference between the exhaust pressure and the accumulator pressure becomes small, While there is a large pressure difference between the pressure of the exhaust gas flowing into the inlet port 10a from the exhaust flow path 11 and the accumulator pressure, the inlet port 10a is connected to the recovery port 10.
b to allow the exhaust gas to flow to the accumulator 12 side, and when the pressure difference between the exhaust pressure and the accumulator pressure becomes small, the inlet port 10
a is communicated with the exhaust port 10c so that the exhaust gas is switched and discharged to the atmosphere. This recovery valve 10
As described later, various mechanisms can be employed as the channel switching mechanism.

Next, the operation of the actuator drive device having the above configuration will be explained.

An overview of the operation of the above actuator drive device is as follows:
When the piston 2 in the drive-output type double-acting cylinder device 1 is driven to the right, high-pressure fluid from a high-pressure air source is used, and when the piston 2 returns, a part of the exhaust gas discharged from the drive-side pressure chamber 3 is transferred to the accumulator. 12, and the accumulator 12
The fluid pressure collected and accumulated is supplied to the return side pressure chamber 4 to perform the return operation.

More specifically, in FIG. 1, the pressure fluid of the accumulator 12 is sent to the return side pressure chamber 4, and the drive side pressure chamber 3 is connected to the switching valve 5 and the recovery valve 1.
If the switching valve 5 is moved to the right from this state and switched to the first switching position, compressed air from the high-pressure air source 7 flows through the air supply flow path 8 and the switching valve 5. , flows into the drive-side pressure chamber 3 via the head-side flow path 6, drives the piston 2 to the right to perform work, and the accompanying exhaust from the return-side pressure chamber 4 flows through the rod-side flow path 9. , the switching valve 5 and the exhaust flow path 11 into the inlet port 10a of the recovery valve 10. The recovery valve 10 switches the outflow path between the recovery port 10b side and the exhaust port 10c side depending on the inflow pressure of the exhaust gas into the inlet port 10a as described above. , are discharged to the outside from the discharge port 10c.

Next, when the switching valve 5 is switched to the second switching position shown in the figure, the high pressure exhaust inside the drive side pressure chamber 3 is
Head side flow path 6, switching valve 5 in second switching position, exhaust flow path 11, inlet port 10 of recovery valve 10
a, flows to the accumulator 12 through the recovery port 10b and the recovery channel 14, and
It is collected and accumulated in 2.

When the pressure of the exhaust gas decreases due to the flow of the exhaust gas into the accumulator 12 and the pressure difference between the exhaust pressure and the accumulator pressure becomes small, the recovery valve 10
Since the inlet port 10a of the inlet port 10a communicates with the exhaust port 10c by the switching mechanism, the remaining exhaust gas in the drive side pressure chamber 3 is released to the atmosphere, and at the same time, the accumulated pressure air in the accumulator 12 is transferred to the circulation path 13 and the second switching mechanism. It flows into the return side pressure chamber 4 of the double-acting cylinder device 1 through the switching valve 5 in the position and the rod side flow path 9, and the piston 2 returns to the left.

Thereafter, the above operation is repeated by alternately switching the switching valve 5 to the first switching position and the second switching position.

Regarding the air balance of the double-acting cylinder drive system, the air pressure of the high-pressure air source 7 is P _H , the internal pressure of the accumulator 12 is P _L1 , and the pressure on the inlet port 10a side when the recovery valve 10 switches the outflow path is the above. P _L2 slightly higher than P _L1 , double acting cylinder device 1
If the volume of is V, then for one stroke of the piston, the amount of air supplied...VP _H The amount of air consumed (released to the atmosphere)...V (P _L1 + P _L2 ) ≒ 2VP _L1 (These amounts of air It means the amount of air converted into 1, and since the atmospheric pressure P _O can be regarded as 1, multiplying each amount of air by 1/P _O (≒1) is omitted.) The difference between them is V(P _H −2P _L1 ), so P _H ≒
If set to 2P _L1 , the air supply amount and air consumption amount will be equal, so the internal pressure P _L1 of the accumulator 12 can always be maintained at P _L1 regardless of the operation of the double-acting cylinder device 1. The air consumption V _H (≒2VP _L1 ) is approximately half that of a conventional double-acting cylinder device. The accumulator pressure may fluctuate up or down depending on the case, but the air pressure flowing from the accumulator into the return side pressure chamber 4 of the cylinder device 1 also increases or decreases, and normally the accumulator pressure is kept almost constant. . Also, the accumulator pressure may increase as the cylinder device is driven;
In that case, the air pressure recovered by the accumulator may be appropriately utilized for other purposes, thereby keeping the pressure of the accumulator substantially constant within a pressure range.

Although the case of a general double-acting cylinder drive system has been described here, the present invention drives the actuator by supplying compressed air from a high-pressure air source to the actuator with output during driving through a switching valve. Then, the actuator is reset by low-pressure compressed air from the accumulator, and a part of the exhaust gas accompanying the return is collected into the accumulator.
This can be applied to an actuator drive system that accumulates output during driving.

Furthermore, when a plurality of double-acting cylinder drive systems having the above configuration are provided, one accumulator can be shared.

Various structures can be adopted as the recovery valve, and examples of the structures are shown in FIGS. 2 to 5.

The recovery valve 10 shown in FIG. 2 is of a switching type that operates by opposing pressures at an inlet port 10a and a recovery port 10b, and a spool 22 is slid into a valve body 21 having an inlet port 10a, a recovery port 10b, and a discharge port 10c. The switching mechanism includes a spring 23, a feedback passage 24, and a pressure chamber 25. When high-pressure exhaust from the cylinder is supplied to the inlet port 10a, the pressure causes the spool 22 to switch to the spring 23. The inlet port 1 is moved to the left against the biasing force of
0a and the recovery port 10b communicate through the through hole 26 in the spool 22, so that the exhaust gas is recovered to the accumulator 12 connected to the recovery port 10b, and when the pressure at the inlet port 10a approaches the pressure inside the accumulator 12, Spring 23
The spool 22 is pushed back to the illustrated position by the biasing force of and the pressure acting on both sides of the spool 22, and the recovery port 10b is closed and the discharge port 10c is opened, so that the spool 22 is moved from the cylinder to the inlet port 10.
The remaining air supplied to a is discharged to the atmosphere through the exhaust port 10c.

In the embodiment shown in Fig. 3, an arbitrary set pressure (or biasing force of a spring, etc.) is applied behind the diaphragm, and the diaphragm, which is displaced by opposition to the pressure at the inlet port, is used to control the recovery valve body and the exhaust gas. It is a setting type that operates the valve body, and the valve body 31
An exhaust valve body 37b and an exhaust valve seat 39 are provided inside, as well as a diaphragm 32 and a pilot pressure chamber 3.
3. A diaphragm 3 provided in the valve body 31 and equipped with a switching mechanism consisting of a flow path 34, a communication hole 35, a recovery valve body 36, a recovery valve seat 37a, and a spring 38.
The pressure inside the accumulator 12 is introduced into the pilot pressure chamber 33 behind the diaphragm 2 through the passage 34, and when the cylinder exhaust gas fed to the inlet port 10a is applied to the lower surface of the diaphragm 32 through the communication hole 35, the When the pressure is high, the diaphragm 32 moves upward and the recovery valve body 36 connected to the diaphragm 32 opens the recovery valve seat 37a leading to the recovery port 10b, so that the high-pressure exhaust from the inlet port 10a is recovered. When the pressure of the exhaust gas recovered by the accumulator 12 via the port 10b and fed to the inlet port 10a becomes low, the diaphragm 32 moves downward and the recovery valve body 36 pushes the exhaust valve body 37b under the biasing force of the spring 38. In order to move downward against this, the exhaust valve body 37b opens the exhaust valve seat 39 that communicates the inlet port 10a with the exhaust port 10c, thereby releasing the residual exhaust gas to the atmosphere.

In the embodiment shown in FIG. 4, the valve body in the flow path leading to the recovery port and the discharge port is operated by the exhaust pressure of the cylinder supplied to the inlet port. It is equipped with a switching mechanism consisting of a valve body 42, its piston part 43, an adjustment screw 44, a spring 45, and an exhaust valve seat 46. acts on the piston portion 43 of the exhaust valve body 42 to move the valve body 42 upward against the biasing force of the spring 45 supported by the adjustment screw 44.
2 into pressure contact with the exhaust valve seat 46 to open the exhaust port 10c.
At the same time, the high-pressure exhaust pushes open the check valve 47 and connects the inlet port 10a to the recovery port 1.
0b, and when the exhaust pressure decreases, the exhaust valve body 42 and check valve 47 return to the illustrated state, and the exhaust gas is discharged from the inlet port 10a to the exhaust port 10c to the atmosphere. .

Furthermore, the embodiment shown in FIG. 5 uses a pressure accumulation chamber and a throttle valve to make it possible to adjust the switching time for switching the flow path from the inlet port to the recovery port to the discharge port. In addition to providing a valve 57, a communication hole 52, a check valve 53a,
Knob 53b, throttle valve 53c, pressure accumulation chamber 54, piston 55, bias spring 56, piston return spring 56a, spool spring 58
When the cylinder exhaust gas fed to the inlet port 10a of the valve body 51 is at high pressure, it is switched from the inlet port 10a to the communication hole 52.
and the pressure accumulator 54 rapidly through the check valve 53a.
Since the piston 55 presses the main valve 57 with the high-pressure exhaust from this cylinder, the main valve 57 is affected by the biasing force of the spool spring 58 and the biasing force of the piston return spring 56a via the bias spring 56. A valve seat 5 between the inlet port 10a and the recovery port 10b is driven against the
9 is opened, and the exhaust gas is communicated to the recovery port 10b and recovered to the accumulator.

The biasing force of each of the springs 56, 58 and the piston return spring 56a is such that the main valve 57 and the piston 55 are activated when the pressure in the pressure accumulation chamber 54 reaches a constant pressure that is slightly higher than the pressure accumulated in the accumulator 12. When the pressure of the air discharged through the inlet port 10a decreases below the above-mentioned constant pressure, the flow rate of the air accumulated in the pressure accumulation chamber 54 can be adjusted using the knob 53b. After some time has elapsed for the flow to flow out through the throttle valve 53c and until the pressure in the pressure accumulation chamber 54 reaches the above-mentioned constant pressure, the main valve 57
is returned, and the cylinder exhaust gas flowing into the inlet port 12 is discharged from the exhaust port 10c.

According to this embodiment, by adjusting the flow rate of the throttle valve 53c using the knob 53b, it is possible to appropriately change the time period during which the pressure in the pressure accumulation chamber 54 falls below the above-mentioned constant pressure.
Even if there are variations in the biasing forces of a and 58 due to manufacturing errors, the pressure can be adjusted to be constant.

[Effects of the invention] The present invention collects and stores the exhaust gas in the accumulator using the recovery valve while the pressure difference between the pressure of the exhaust gas discharged from the drive side pressure chamber of the output type double-acting actuator during driving and the accumulator pressure is large. However, since the collected and accumulated exhaust gas is used to return the double-acting actuator, the energy of the exhaust air can be used effectively, and the amount of high-pressure air consumed can be reduced.

In addition, the present invention allows the exhaust inlet port of the recovery valve to be discharged when the pressure of the exhaust discharged from the drive-side pressure chamber of the drive-output type double-acting actuator decreases and the pressure difference between the exhaust pressure and the accumulator pressure becomes small. Since the remaining exhaust air in the drive side pressure chamber is communicated with the port and released to the atmosphere, the accumulated pressure air collected and accumulated in the accumulator is used to return the double-acting actuator, but the exhaust air in the drive side pressure chamber is not used to drive the drive side pressure chamber. This has the effect of preventing hindrance when the time output type double-acting actuator returns.

[Brief explanation of drawings]

FIG. 1 is a circuit diagram of an actuator drive device according to the present invention, and FIGS. 2 to 5 are sectional views showing different embodiments of recovery valves suitable for use therein. 3... Drive side pressure chamber, 4... Return side pressure chamber, 5
...Switching valve, 7...High pressure air source, 10...Recovery valve, 10a...Inlet port, 10b...Recovery port, 10c...Discharge port, 12...Accumulator.

Claims (1)

[Scope of utility model registration request] When the switching valve that controls the drive of the drive output type double-acting actuator, which is equipped with a drive side pressure chamber and a return side pressure chamber, is in the first switching position, the drive side pressure chamber, the high pressure air source, and the return side are connected to each other. The pressure chamber and the inlet port of the recovery valve are communicated with each other, and the second
comprising a switching valve that communicates the drive side pressure chamber with the inlet port and the return side pressure chamber with the accumulator at the switching position,
The recovery valve is connected to three ports: the inlet port, the recovery port connected to the accumulator, and the exhaust port opened to the atmosphere, and the inlet port is communicated with the recovery port while the pressure difference between the exhaust pressure and the accumulator pressure is large. An actuator drive device comprising: a switching mechanism that automatically switches the inlet port to communicate with the discharge port when the pressure difference between the exhaust pressure and the accumulator pressure becomes small.