JPH022964Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an exhaust pressure recovery device that recovers and stores exhaust pressure from an actuator in an accumulator.

[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 to the atmosphere via the directional control valve.

[Problems to be solved by the invention] 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 not directly released into the atmosphere. Emitting it is problematic from the perspective of energy conservation.

However, if the air discharged from the cylinder is simply collected and stored, it will create back pressure that will impede the driving of the cylinder.

The present invention collects and stores a part of the exhaust gas discharged from the actuator in an accumulator, making it possible to use the energy effectively.
In recovering the exhaust gas, the problem to be solved is to prevent the exhaust gas collected and accumulated in the accumulator from becoming back pressure on the actuator.

[Means for Solving the Problems] The present invention provides an actuator drive system that drives an actuator by supplying compressed air from a high-pressure air source to the actuator via a switching valve. An accumulator is connected to a flow path for exhaust gas discharged from the exhaust gas through a recovery valve, and the collection valve is connected to an exhaust inlet port connected to the exhaust flow path, a recovery port connected to the accumulator, and an exhaust port communicating with the atmosphere. While the pressure difference between the exhaust pressure and the accumulator pressure is large, the exhaust 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 communicated with the recovery port. The above-mentioned problem was solved by using a switching mechanism that automatically switches to communicate with the discharge port.

[Function] Exhaust gas discharged from the actuator when the actuator is driven or returned by switching the directional control valve is fed to the exhaust inlet port of the recovery valve, and in this recovery valve, the exhaust pressure is equal to the exhaust pressure at the initial stage of operation of the actuator. While the pressure difference between the exhaust pressure and the accumulator pressure is large, the inlet port communicates with the recovery port, and the exhaust gas is collected and accumulated in the accumulator through the recovery port.When the pressure difference between the exhaust pressure and the accumulator pressure becomes small in the later stages of actuator operation, the inlet port communicates with the recovery port. Since the flow path from the port is switched to the exhaust port, the exhaust gas is discharged to the atmosphere and a reduction in output due to back pressure is prevented.

[Embodiment] Hereinafter, an embodiment of the present invention will be described in detail based on the drawings. In FIG. It shows the collection section that collects and accumulates.

The cylinder drive section 1 includes a double-acting cylinder 3, a high-pressure air source 4 for driving the double-acting cylinder 3, and a directional switching valve 5 for switching a flow path between these. It is configured to selectively switch between the head side flow path 6 and rod side flow path 7 of No. 3, and the air supply flow path 8 and exhaust flow path 9 communicating with the high pressure air source 4.

The recovery unit 2 also includes a recovery valve 10 connected to the exhaust flow path 9 to recover exhaust gas from the cylinder drive unit 1, and an accumulator 11 connected to the recovery port side of the recovery valve 10. The recovery valve 10 has three ports: an exhaust inlet port 12 connected to the exhaust flow path 9, a recovery port 13 connected to the accumulator 11, and an exhaust port 14 communicated with the atmosphere; In other words, when the exhaust pressure starts to flow into the accumulator, which is set at a sufficiently lower pressure than that at the beginning of cylinder operation, and the pressure has not yet dropped to that low, and the accumulator pressure has not risen that much, the exhaust pressure The exhaust inlet port 12 is communicated with the recovery port 13 while the pressure difference between When the pressure is lower than the initial pressure and the accumulator pressure is slightly increased, when the pressure difference between the exhaust pressure and the accumulator pressure becomes small, the exhaust inlet port 12 is automatically connected to the exhaust port 14. It consists of a switching mechanism that switches automatically. The flow path switching mechanism in this recovery valve 10 is as follows:
Various mechanisms can be employed, as described below.

The embodiment shown in FIG. 2 shows a case where the cylinder drive unit 1 is a single-acting cylinder drive system, and the cylinder drive unit 1 includes a single-acting cylinder 15, a high-pressure air source 4, and a directional switching valve 16. The air supply passage 18 or the exhaust passage 1 communicates the head side passage 17 of the single-acting cylinder 15 with the high pressure air source 4 through the directional switching valve 16.
It is configured to selectively switch to 9.

Thus, the collecting section 2 in this embodiment is similar to that in the embodiment of FIG.

Although the case of a general double-acting and single-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 via a switching valve. It can be applied to actuator drive systems.

In the exhaust pressure recovery device having such a configuration, the exhaust gas discharged from the cylinder as the cylinder is driven or returned by switching the directional control valve is fed to the exhaust inlet port 12 of the recovery valve 10. , the inlet port 12 communicates with the recovery port 13 while the exhaust gas is at high pressure, and as the pressure of the exhaust becomes low, the flow path from the inlet port 12 is switched to the exhaust port 14, so that the high-pressure exhaust is discharged. During this period, it is collected and accumulated in the accumulator 11 through the collection port 13, and when the pressure at the inlet port 12 reaches a certain switching pressure,
The reduced pressure exhaust gas is released into the atmosphere. Therefore, a portion of the exhaust gas is collected into the accumulator 11 for each stroke of the cylinder.

The volume and form of the accumulator 11 can be selected depending on the scale of the cylinder drive system, the purpose of the recovered exhaust gas, etc., and an adjustment mechanism such as a variable volume type can be added as necessary. In addition, the compressed air collected and accumulated in the accumulator 11 in this way can be used as: (a) an air pressure source for systems that use low-pressure air as a working medium, such as signal air systems and cylinder drive systems that do not require output, and (b) high-pressure air. Suitable for use as a cooling air source for power system air cooling, etc. (c) An air source that is pressurized by a compressor and circulated back to the cylinder drive unit, etc.

Various structures can be adopted as the recovery valve, and examples of the structures are shown in FIGS. 3 to 6.

The recovery valve 10 shown in FIG. 3 is of a differential switching type in which the pressures of an inlet port 12 and a recovery port 13 are opposed, and a spring 22 is installed in a valve body 20 having an inlet port 12, a recovery port 13, and a discharge port 14.
When the inlet port 12 is supplied with high pressure exhaust from the cylinder, the pressure causes the spool 21 to be energized.
is moved to the left against the urging force of the spring 22 and the feedback pressure in the pressure chamber 24 communicating with the recovery port 13 through the feedback passage 23, and the inlet port 12 and the recovery port 13 are connected through the through hole 25 in the spool 21. By communicating with each other, exhaust gas is recovered to the accumulator connected to the recovery port 13, and when the pressure at the inlet port 12 approaches the pressure inside the accumulator, the spring 2
The spool 21 is pushed back to the illustrated position by the biasing force of 2 and the pressure acting on both sides of the spool 21, and the recovery port 13 is closed and the discharge port 14 is opened to feed the fluid from the cylinder to the inlet port 12. The remaining air is discharged to the atmosphere through the exhaust port 14.

In the embodiment shown in Fig. 4, 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 of 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 26
The accumulator 1 is passed through a flow path 29 to a pilot pressure chamber 28 behind a diaphragm 27 provided in the
When the cylinder exhaust gas supplied to the inlet port 12 is applied to the lower surface of the diaphragm 27 through the communication hole 30, if the pressure is high, the diaphragm 27 moves upward. Since the recovery valve body 31 connected to the diaphragm 27 opens the recovery valve seat 32 communicating with the recovery port 13, high-pressure exhaust from the inlet port 12 is recovered to the accumulator 11 via the recovery port 13, and the inlet port 12 When the pressure of the exhaust gas supplied to the diaphragm 27 decreases, the diaphragm 27 moves downward and the recovery valve body 31 moves the exhaust valve body 33 to the spring 3.
4, the exhaust valve body 33 opens the exhaust valve seat 35 that communicates the inlet port 12 with the exhaust port 14, thereby releasing the residual exhaust gas to the atmosphere.

In the embodiment shown in FIG. 5, the valve body of 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. When the exhaust gas is at a high pressure, it acts on the piston portion 38 of the exhaust valve body 37, and the valve body 37 is moved by the adjusting screw 39.
By moving the exhaust valve element 37 upward against the biasing force of the spring 40 supported by the exhaust valve seat 41, the exhaust port 14 is closed, and the high-pressure exhaust gas closes the check valve 42. Push it open to communicate the inlet port 12 with the recovery port 13, and when the exhaust gas level decreases, the exhaust valve body 37
The check valve 42 then returns to the state shown and the exhaust gas is discharged from the inlet port 12 through the exhaust port 14 to the atmosphere.

Furthermore, the embodiment shown in FIG. 6 uses a pressure accumulation chamber and a throttle valve to make it possible to adjust the timing of switching the flow path from the inlet port to the recovery port to the discharge port. 1
When the exhaust gas from the cylinder 2 is at high pressure, it rapidly flows from the inlet port 12 through the communication hole 44 and the check valve 45 into the pressure accumulator 46, and the piston 47 collects the high pressure exhaust gas from the cylinder. In order to press the main valve 49 with the bias spring 48, the main valve 49 is driven against the biasing force of the spool spring 50, and the valve seat 51 between the inlet port 12 and the recovery port 13 is opened. Then, the exhaust gas passes through the recovery port 13 and is recovered to the accumulator 11.

The biasing force of each of the springs 48, 50 and the piston return spring is such that the main valve 49 and the piston 47 are activated when the pressure in the pressure accumulation chamber 46, that is, the pressure in the inlet port 12, and the pressure in the accumulator 11 reach a certain pressure difference. Therefore, when the pressure of the air at the inlet port 12 decreases due to the inflow into the low-pressure accumulator, the flow rate of the air accumulated in the pressure accumulator 46 is adjusted by the knob 52. Possible throttle valve 53
After some time has passed, the pressure inside the pressure accumulating chamber 46 decreases to the above pressure difference. Therefore, the main valve 49 returns and the inlet port 12
The cylinder exhaust gas flowing into the cylinder is discharged from the exhaust port 14.

According to this embodiment, by selecting the volume of the pressure accumulation chamber 46 and adjusting the flow rate of the throttle valve 53 using the knob 52, it is possible to appropriately change the time period during which the pressure in the pressure accumulation chamber decreases.

[Effects of the invention] In the present invention, while the exhaust gas discharged from the actuator is under high pressure at the initial stage of operation of the actuator, the exhaust gas is collected and stored in the accumulator by the recovery valve, so that the energy of the exhaust gas can be effectively used. In addition, in the latter half of the actuator's stroke, the recovery valve is switched to allow the low-pressure exhaust to flow out from the exhaust port to the atmosphere, so the pressure in the accumulator becomes back pressure in the latter half of the actuator's stroke. This has the effect of preventing this.

[Brief explanation of drawings]

1 and 2 are circuit diagrams showing different circuit examples of the exhaust pressure recovery device according to the present invention, and FIGS. 3 to 6 are sectional views showing different embodiments of recovery valves suitable for use therein. be. 4... High pressure air source, 10... Recovery valve, 11...
Accumulator, 12... Inlet port, 13...
Recovery port, 14...Discharge port.

Claims (1)

[Scope of utility model registration request] In an actuator drive system that drives an actuator by supplying compressed air from a high-pressure air source to the actuator via a switching valve,
An accumulator is connected via a recovery valve to a flow path for exhaust gas discharged from the actuator via the switching valve, and the recovery valve is connected to an exhaust inlet port connected to the exhaust flow path, a recovery port connected to the accumulator, and While the pressure difference between the three exhaust ports communicating with the atmosphere and the exhaust pressure and the accumulator pressure is large, the exhaust inlet port is communicated with the recovery port, and when the pressure difference between the exhaust pressure and the accumulator pressure becomes small. and a switching mechanism that automatically switches the exhaust inlet port to communicate with the exhaust port.