JPH0519868A - Valve and method for pressure control - Google Patents

Abstract

PURPOSE:To perform highly precise pressure control at a high speed regardless of the load capacity of a body to be applied with pressure such as a cylinder. CONSTITUTION:A pressure reception body 20 partitions the inside of a pressure chamber 19 into a pilot chamber 23 and a feedback chamber 24. A pressure sensor 33 which detects the pressure on the side of an output port 4 is provided. Further, an air intake-side valve 29 which controls pressure applied from an air intake port 3 to the pilot chamber 23 and an air outlet-side valve 31 which controls pressure discharged from the pilot chamber 23 are provided. A passage 39 which connects the pilot chamber 23 to the side of the output port 4 is provided and an orifice 38 is arranged in the passage 39. When the load capacity of the body to be applied with the pressure is large and it takes a long time to make the pressure on the side of the output port 4 reach set pressure, even if the pressure in the pilot chamber 23 is becoming high, it is discharged to the side of the output port 4 through the orifice 38.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pressure control valve and its pressure control method.

[0002]

2. Description of the Related Art Conventionally, as a pressure control valve, there is one disclosed in, for example, Japanese Patent Application Laid-Open No. 2-284213. In this pressure control valve, the on-off valve that opens and closes the gas flow path is opened and closed by the reciprocating movement of the pressure receiving body, and the pressure receiving body is reciprocated according to the pressure fluctuation in the pilot chamber.
Further, in this pressure control valve, a pressure sensor for detecting the pressure on the output port side of the flow path, an air supply side solenoid valve for controlling the pressure supplied from the supply port side of the flow path into the pilot chamber, An exhaust side solenoid valve for controlling the pressure discharged from the pilot chamber to the outside is provided. Then, the controller opens and closes each solenoid valve based on the difference between the pressure detected by the pressure sensor and the set pressure to supply or discharge the pressure to the pilot chamber, thereby changing and controlling the pressure in the pilot chamber. The open / close valve is opened / closed according to the change in the pressure, and the pressure of the output port is controlled to the set pressure.

[0003]

However, in the conventional pressure control valve described above, the load capacity of the pressure-supplied supply body such as the cylinder to which the pressure gas is supplied from the output port is large, and the pressure of the output port is equal to the set pressure. If it takes time to reach the set pressure, that is, if the pressure at the output port is lower than the set pressure for a long time, the controller opens the solenoid valve on the air supply side in order to bring the pressure at the output port closer to the set pressure. To increase the pressure in the pilot room. In other words, in this pressure control valve, the solenoid valve is controlled to open and close based on the difference between the set pressure and the pressure of the output port, so if the state where the pressure of the output port is lower than the set pressure becomes long, the pressure of the pilot chamber will increase. Very high. As a result, the on-off valve is greatly opened, and a large amount of pressure gas from the air supply port is supplied to the output port, so the output port pressure can be brought close to the set pressure at high speed, but the pilot chamber pressure is Since the pressure is high regardless of the difference between the pressure and the set pressure, there is a problem that the return of the on-off valve is delayed when the pressure of the output port reaches the set pressure, and accurate pressure control cannot be performed.

In order to solve this problem, for example, a configuration may be considered in which the opening of the air supply side solenoid valve is controlled so that the pressure at the output port slowly approaches the set pressure.
With this, high-speed pressure control cannot be expected.

The present invention has been made to solve the above problems, and an object thereof is to perform pressure control at high speed and with high accuracy even if the load capacity of a pressure-supplied body such as a cylinder is large. A pressure control valve and a pressure control method therefor are provided.

[0006]

In order to achieve the above-mentioned object, in the first invention, a gas flow channel having ports formed at both ends thereof and the flow channel provided between the both ports are provided. An opening / closing unit having a valve body that opens and closes the flow path, a pressure receiving body that opens and closes the valve body according to pressure fluctuations in the pilot chamber, and a pressure sensor that detects the pressure of the flow path on the one port side, Based on the detection signal of the pressure sensor,
In a pressure control valve having control means for changing and controlling the pressure of the pilot chamber, a passage for releasing the internal pressure of the pilot chamber is connected to the pilot chamber, and an orifice is provided in the passage.

In a second aspect of the invention, a feedback chamber is provided which is partitioned from the pilot chamber by the pressure receiving body and communicates with the flow path on the one port side to introduce the pressure on the one port side. A pressure sensor detects the pressure in the feedback chamber.

In the third invention, another pressure sensor for detecting the pressure in the pilot chamber is provided, and when the difference between the pressure detected by the pressure sensor and the pressure detected by the pressure sensor is larger than a predetermined value, or both pressures. If it takes a long time to match, the control means is controlled based on the pressure detected by another pressure sensor.

According to the fourth aspect of the invention, the pressure in the flow passage on the one port side is introduced into the feedback chamber, and the pressure fluctuation in the feedback chamber due to the movement of the pressure receiving body is detected by the pressure sensor, and the detection signal of the pressure sensor is detected. Based on the above, the control means changes the pressure of the pilot chamber, and the valve body is opened / closed via the pressure receiving body according to the pressure fluctuation of the pilot chamber, thereby opening / closing the flow path. is there.

In the fifth aspect of the invention, the pressure in the flow passage on one port side is detected by the pressure sensor, and the pressure in the pilot chamber is detected by another pressure sensor. The pressure detected by this pressure sensor and the pressure sensor When the difference from the detected pressure is larger than a predetermined value or when it takes time for the two pressures to coincide with each other, the control means changes and controls the pressure of the pilot chamber based on the detected pressure of another pressure sensor, According to the pressure fluctuation in the pilot chamber, the valve body is opened / closed via the pressure receiving body, whereby the opening / closing of the flow path is controlled.

[0011]

Therefore, according to the first aspect of the present invention, when the pressure capacity of the pressure-supplied body such as the cylinder is large and it takes time for the pressure at one port to reach the set pressure, the pressure in the pilot chamber is reduced. Even if the pressure becomes high, the pressure is released through the orifice, so that the pressure in the pilot chamber does not become abnormally high. Therefore, when the pressure of one port reaches the set pressure, the valve element of the opening / closing section immediately returns, and the pressure of the one port does not exceed the set pressure.

According to the second and fourth aspects of the invention, when the pressure in the pilot chamber rises and the pressure receiver moves, the pressure entering the feedback chamber is momentarily compressed and becomes higher than the pressure in one port. The increased pressure in the feedback chamber is detected by the pressure sensor. That is, since the detected pressure is higher than the pressure of one port at the time of the detection, the pressure detected by the pressure sensor is detected as the pressure rising earlier than the actual pressure of the port. If the control means is controlled based on that pressure, even if it takes time for the pressure at one port to reach the set pressure, that time can be apparently shortened, and the pressure in the pilot chamber becomes abnormal. It does not rise.

According to the third and fifth aspects of the invention, when the difference between the pressure detected by the pressure sensor and the pressure detected by another pressure sensor is larger than a predetermined value, or when it takes time for the two pressures to coincide with each other. Since the pressure control is performed based on the pressure detected by the pilot chamber of another pressure sensor, the pressure in the pilot chamber does not rise abnormally.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. As shown in FIG. 1, a flow path 2 for gas is formed in the valve housing 1, and both ends of the flow path 2 are an air supply port 3 and an output port 4, respectively.
The opening / closing part 5 for opening / closing the flow path 2 has a valve seat 6 and a valve body 7, and the valve body 7 is slidably fitted into a back chamber 8 formed at a position facing the valve seat 6. There is. The valve body 7 is biased toward the valve seat 6 by the spring 9, and in the state of FIG. 1, the valve body 7 is pressed against the valve seat 6 and the flow path 2 is closed. Further, the valve body 7 includes the output port 4 side of the flow path 2 and the back chamber 8.
Is formed with a communication hole 7a that communicates with the communication hole 7a.
The valve body 7 is pressure-balanced by making the pressures of the output port 4 side and the back chamber 8 side of the valve body 7 equal to each other via.

Another flow channel 10 is the output port 4 of the flow channel 2.
It is formed in the valve housing 1 so as to communicate with the side, and an end portion thereof is an exhaust port 11. The first housing cover 12 is attached to the upper surface of the valve housing 1. Opening / closing unit 1 for opening / closing the flow path 10
3 has a valve seat 14 and a valve body 15, and the valve body 15 has a valve seat 14
Is slidably fitted into the back chamber 16 formed in the first housing cover 12 at the opposing position. And
The valve body 15 is biased toward the valve seat 14 by the spring 17, and in the state of FIG. 1, the valve body 15 is pressed against the valve seat 14 to close the flow path 10. Further, the valve body 15 is formed with a communication hole 15a for communicating the output port 4 side of the flow path 2 and the back chamber 16 with each other, and the valve body 1 is connected through this communication hole 15a.
By making the pressures of the output port 4 side and the back chamber 16 side of No. 5 the same, the valve element 15 is pressure balanced.

The second housing cover 18 is attached to the upper surface of the first housing cover 12, and both cover 1
A pressure chamber 19 is formed between 2 and 18, and a pressure receiving body 20 is arranged between the covers 12 and 18 so as to be located in the pressure chamber 19. The pressure receiving body 20 is the second
Housing cover 18 and first housing cover 12
It is composed of a diaphragm 21 sandwiched and fixed between and, and a pressure receiving plate 22 sandwiching the diaphragm 21 from both sides. Pressure receiver 20 and second housing cover 18
The pressure receiving body 20 defines a pressure chamber 19 so that a pilot chamber 23 is formed between the pressure receiving body 20 and the first housing cover 12 and a feedback chamber 24 is formed between the pressure receiving body 20 and the first housing cover 12.

The rod 25 is fixed to the pressure receiving body 20 by a nut 26, and the rod 25 and the pressure receiving body 20 are connected to each other by the rod 2.
5, it is possible to reciprocate integrally along the axial direction.
The rod 25 extends through the first housing cover 12 and the valve body 15 to the vicinity of the upper surface of the valve body 7. A ring 27 is fixed to a substantially middle portion of the rod 25, and the ring 27 can be engaged with the lower surface of the valve body 15. Then, the internal pressure of the pilot chamber 23 becomes higher than the internal pressure of the feedback chamber 24, and the pressure receiving body 2
When the rod 25 is moved downward together with 0, the rod 25
The lower end of the valve contacts the valve body 7 and pushes down the valve body 7 against the urging force of the spring 9 to open the opening / closing portion 5. Further, when the internal pressure of the feedback chamber 24 becomes larger than the internal pressure of the pilot chamber 23 and the rod 25 is moved upward together with the pressure receiving body 20, the ring 27 of the rod 25 engages with the valve body 15 to cause the valve body 15 to move. 15 is pushed up against the biasing force of the spring 17 to open the opening / closing part 13.

The air supply passage 28 is the air supply port 3 of the flow path 2.
The valve housing 1, the first housing cover 12, and the second housing cover 18 are formed so as to connect the side and the pilot chamber 23. The air supply side valve 29, which is an electromagnetic valve, has a second valve for controlling the opening and closing of the air supply passage 28.
Is provided on the housing cover 18, and high pressure gas on the side of the air supply port 3 is introduced into the pilot chamber 23 as necessary to raise the internal pressure thereof. The exhaust passage 30 is formed in the second housing cover 18 so as to connect the pilot chamber 23 and the outside. Exhaust valve 3 consisting of a solenoid valve
1 is provided on the second housing cover 18 so as to control the opening and closing of the exhaust passage 30, and discharges the gas in the pilot chamber 23 to the outside to reduce the internal pressure thereof, if necessary. The air supply side valve 29 and the exhaust side valve 31 constitute a control means.

The feedback passage 32 connects the output port 4 side of the flow passage 2 and the feedback chamber 24 so that the valve housing 1 and the first housing cover 1 are connected.
2 is formed. Therefore, the pressure on the output port 4 side of the flow path 2 is introduced into the feedback chamber 24. The pressure sensor 33 is provided on the second housing cover 18,
The passage 34 includes the feedback passage 32 and the pressure sensor 3
The second housing cover 1 so as to communicate with the lower surface of
8 are formed. Then, the pressure sensor 33 detects the internal pressure of the passage 34 communicating with the output port 4 side of the flow path 2 and the feedback chamber 24 via the feedback passage 32, and outputs a detection signal.

The cover 35 is the second housing cover 18
Is attached on the first housing cover 12 so as to cover the air supply side valve 29, the exhaust side valve 31, and the pressure sensor 33.
Covers. An exhaust hole 36 is formed on the side surface of the cover 35. Further, a substrate 37 is arranged in the cover 35, and a control circuit for controlling opening / closing of the air supply side valve 29 and the exhaust side valve 31 based on the detection signal from the pressure sensor 33 is mounted on the substrate 37. There is. That is, the pressure sensor 33
When the pressure detected on the output port 4 side is lower than the input set pressure, the supply side valve 29 is opened to supply the pressure on the supply port 3 side of the flow path 2 into the pilot chamber 23. To do. When the pressure on the output port 4 side is lower than the set pressure, the exhaust side valve 31 is opened to discharge the pressure in the pilot chamber 23 to the outside.

The passage 39 is the passage 34 and the pilot chamber 2
An orifice 38 is formed in the passage 39 of the orifice 38. This orifice 38
Is for releasing the pressure gas in the pilot chamber 23 to the output port 4 side when the internal pressure of the pilot chamber 23 is higher than the pressure on the output port 4 side. That is, when the load capacity of the pressure-supplied supply body such as the cylinder to which the pressure gas is supplied from the output port 4 is large, the pressure on the output port 4 side is lower than the set pressure, and it takes time to reach the set pressure, The pressure gas in the pilot chamber 23 is sent to the output port 4 side via the orifice 38.

Next, the operation of the pressure control valve configured as described above will be described. Now, FIG. 1 shows a state in which the pressures in the pilot chamber 23 and the feedback chamber 24 are balanced, and in this state, the rod 25 is in the neutral position and the opening / closing portions 5, 13 on the air supply side and the exhaust side are closed. ing.

When the pressure gas is supplied to the air supply port 3 and the pressure on the output port 4 side detected by the pressure sensor 33 is lower than the set pressure, the air supply side valve 29 is controlled by the control circuit on the substrate 37. Is controlled to open and pilot room 2
The pressure on the air supply port 3 side of the flow path 2 is supplied into the inside 3. Thereby, the feedback chamber 24 leading to the output port 4
Becomes smaller than the internal pressure of the pilot chamber 23, and the pressure receiving body 20 is moved downward according to the pressure difference. Along with this, the rod 25 is moved downward, and the lower end of the rod 25 comes into contact with the valve body 7 to push down the valve body 7 and open the opening / closing portion 5. As a result, the pressure gas in the air supply port 3 is supplied to the output port 4, and the pressure on the output port 4 side is increased to the set pressure.

When the pressure on the output port 4 side detected by the pressure sensor 33 is higher than the set pressure, the substrate 37
The exhaust side valve 31 is controlled to be opened by the above control circuit, and the pressure gas in the pilot chamber 23 is discharged to the outside. As a result, the internal pressure of the feedback chamber 24 becomes higher than the internal pressure of the pilot chamber 23, and the pressure receiving body 20 is moved upward according to the pressure difference. Along with this, the rod 25 is moved upward, and the ring 27 of the rod 25 engages with the valve body 15 to push up the valve body 15 and open the opening / closing portion 13.
As a result, the excess pressure gas in the output port 4 causes the flow path 10
Is discharged from the exhaust port 11 to the atmosphere via the air, and the pressure on the output port 4 side is reduced to the set pressure.

If the load capacity of the pressure-supplied body such as a cylinder is large, it takes time for the pressure on the output port 4 side to reach the set pressure. That is, the state in which the pressure on the output port 4 side is lower than the set pressure becomes longer, and the supply circuit valve 29 is controlled to be opened by the control circuit on the substrate 37, and the internal pressure of the pilot chamber 23 is increased. Then, the pressure in the pilot chamber 23 becomes significantly larger than the pressure on the output port 4 side, and the pressure gas in the pilot chamber 23 becomes the orifice 38.
The pressure on the output port 4 side is rapidly increased together with the pressure of the gas discharged to the output port 4 side via the air supply port 3, and the pilot chamber 23
The internal pressure will not rise abnormally. Therefore, the pressure on the output port 4 side can be brought close to the set pressure at high speed, and when the pressure on the output port 4 side reaches the set pressure, the valve body 7 can immediately return to the closed state, and the output port 4 side Pressure does not exceed the set pressure. Therefore,
Even if the load capacity of the pressure-supplied body is large, high-speed and accurate pressure control can be performed, and high accuracy can be maintained.

Further, when the load capacity of the pressure-supplied body is not so large, the amount of pressure released from the orifice 38 decreases, and the pressure is increased based on the opening / closing operation of each opening / closing section 5, 13 as described above. Control is performed. Therefore, stable pressure control can be performed regardless of the load capacity of the pressure-supplied body.

Next, another example of the present invention will be described with reference to FIG. Now, in the pressure control valve of this another example, the feedback passage 32 and the passage 34 are provided in the feedback chamber 2
4 are communicated with each other. When the pressure gas is supplied to the air supply port 3 and the pressure on the output port 4 side detected by the pressure sensor 33 is lower than the set pressure, the air supply side valve 29 is controlled to be opened as described above. The internal pressure of the pilot chamber 23 is increased and the pressure receiving body 20 is moved downward.
At this time, the pressure that enters the feedback chamber 24 from the output port 4 via the feedback passage 32 is momentarily compressed to a pressure higher than the output pressure of the output port 4, and the downward movement of the pressure receiving body 20 becomes slower. The increased internal pressure of the feedback chamber 24 is detected by the pressure sensor 33 via the passage 34. Since the detected pressure is higher than the output pressure of the output port 4 at the time of the detection, the pressure detected by the pressure sensor 33 is a pressure that rises earlier than the actual output pressure of the output port 4. To be detected. That is, from the pressure sensor 33 to each valve 2
When the pressure detection signal sent to 9, 31 is sent earlier, the load capacity of the pressure-supplied body such as a cylinder is large, and the pressure on the output port 4 side is lower than the set pressure for a long time. However, the low state can be apparently shortened, and the passage 39 and the orifice 3 of the above-described embodiment can be shortened.
Combined with the action and effect of 8, it is possible to suppress an abnormal increase in the internal pressure of the pilot chamber 23, and to perform stable pressure control regardless of the load capacity of the pressure-supplied body. The above effect is effective even when the passage 39 and the orifice 38 are not provided.

Next, another example of the present invention will be described with reference to FIG. Now, in the pressure control valve of this another example, the pilot chamber 2 is provided on the second housing cover 18.
Another pressure sensor 40 is provided for detecting the internal pressure of 3. The internal pressure of the pilot chamber 23 detected by the pressure sensor 40 and the pressure sensor 33
When the difference from the pressure on the output port 4 side detected in step 1 is larger than a predetermined value or when it takes time for both the pressures to match, pressure control is performed based on the pressure detected by the pressure sensor 40. In other cases, pressure control is performed based on the pressure detected by the pressure sensor 33. That is, for example, when the load capacity of the pressure-supplied body such as a cylinder is large and the state where the pressure on the output port 4 side is lower than the set pressure becomes long, the internal pressure of the pilot chamber 23 and the pressure on the output port 4 side are increased. When the difference between and becomes larger than a predetermined value, pressure control is performed based on the pressure detected by the pressure sensor 40,
Combined with the effects of the passage 39 and the orifice 38 of the above-described embodiment, it is possible to suppress an abnormal increase in the internal pressure of the pilot chamber 23, and to perform stable pressure control regardless of the load capacity of the pressure-supplied body. It can be carried out.
The above effect is effective even when the passage 39 and the orifice 38 are not provided.

The present invention is not limited to the above-described embodiment. For example, the orifice 38 is arranged in the exhaust passage 30, or a variable orifice such as a rubber orifice is used as the orifice 38, and the pilot chamber 23 and the output port. The passage amount of gas may be changed according to the pressure difference with the 4 side, or the flow passage and the opening / closing portion may be provided only at one place excluding the flow passage 10 and the opening / closing portion 13 on the exhaust side. It is also possible to embody by arbitrarily changing the configuration of each unit without departing from the spirit of the invention.

[0030]

As described above in detail, according to the present invention, it is possible to achieve an excellent effect that pressure control can be performed at high speed and with high accuracy regardless of the load capacity of a pressure-supplied body such as a cylinder. To do.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of a pressure control valve embodying the present invention.

FIG. 2 is a cross-sectional view showing another example of the pressure control valve.

FIG. 3 is a cross-sectional view showing another example of the pressure control valve.

[Explanation of symbols]

2 flow paths, 3 air supply port, 4 output port, 5 opening / closing part, 7 valve body, 20 pressure receiving body, 23 pilot chamber, 29
Supply side valve (control means), 31 Exhaust side valve (control means), 33 Pressure sensor, 38 Orifice, 39 Passage, 40 Pressure sensor.

Claims (5)

[Claims] 1. A gas flow path (2) having ports (3, 4) formed at both ends thereof, and the flow path (2) provided between the both ports (3, 4). An opening / closing section (5) having a valve body (7) for opening and closing 2); a pressure receiving body (20) for opening and closing the valve body (7) according to pressure fluctuations in the pilot chamber (23); Pressure sensor (33) for detecting the pressure in the flow path (2) on the port (4) side of the control unit, and control means for changing and controlling the pressure in the pilot chamber (23) based on the detection signal of the pressure sensor (33). (2
9, 31), a passage (39) for discharging the internal pressure is connected to the pilot chamber (23), and an orifice (38) is provided in the passage (39). A pressure control valve characterized in that 2. The pressure receiving body (20) separates from the pilot chamber (23) and communicates with the flow passage (2) on the side of the one port (4), and the channel on the side of the one port (4) is connected. Feedback chamber where pressure is introduced (24)
The pressure control valve according to claim 1, wherein the pressure sensor (33) detects the pressure of the feedback chamber (24). 3. A separate pressure sensor (40) for detecting the pressure in the pilot chamber (23) is provided, and the difference between the pressure detected by the pressure sensor (40) and the pressure detected by the pressure sensor (33) is predetermined. When it is larger than the value or when it takes time for the two pressures to coincide with each other, the control means (29, 3) is based on the pressure detected by another pressure sensor (40).
The pressure control valve according to claim 1, wherein the pressure control valve is configured to control 1). 4. The pressure of the flow passage (2) on the side of one port (4) is introduced into the feedback chamber (24), and the pressure fluctuation of the feedback chamber (24) due to the movement of the pressure receiving body (20) is controlled. It is detected by the sensor (33), and based on the detection signal of the pressure sensor (33), the control means (29, 3)
The pressure in the pilot chamber (23) is changed and controlled by 1),
A pressure characterized in that the valve body (7) is opened and closed through the pressure receiving body (20) according to the pressure fluctuation of the pilot chamber (23), and thereby the flow passage (2) is controlled to be opened and closed. Control valve pressure control method. 5. The pressure sensor (33) detects the pressure of the flow path (2) on the side of one port (4) and the pressure sensor (40) detects the pressure of the pilot chamber (23). If the difference between the pressure detected by the pressure sensor (40) and the pressure detected by the pressure sensor (33) is larger than a predetermined value or if it takes time for both pressures to coincide with each other, another pressure sensor (40 ), The control means (29, 31) changes and controls the pressure in the pilot chamber (23), and the valve body is passed through the pressure receiving body (20) according to the pressure fluctuation in the pilot chamber (23). A pressure control method for a pressure control valve, characterized in that (7) is opened and closed to thereby control the opening and closing of the flow path (2).