JP7166993B2 - electropneumatic regulator - Google Patents

Description

The present invention provides an electro-pneumatic regulator comprising an air supply control valve and an exhaust control valve that operate a main valve section, and a control section that controls the air supply control valve and the exhaust control valve, the control section is an electro-pneumatic regulator that adjusts the output pressure value of the control fluid by controlling the control valve for air supply or the control valve for exhaust based on the target pressure value indicated by the control device and operating the main valve unit. It is about.

An electropneumatic regulator is a fluid control device that adjusts the output pressure value at an output port of a control fluid input from an input port by a main valve section. The adjustment of the output pressure value is based on the target pressure value indicated by an external control device connected to the electro-pneumatic regulator. It is performed by controlling the opening and closing of the valve and operating the main valve. The control unit detects the output pressure value of the control fluid at the output port with a pressure sensor, and pulse width modulates the air supply control valve and the exhaust control valve based on the pressure difference between the output pressure value and the target pressure value. (Pulse Width Modulation (PWM)) control. Thereby, the electropneumatic regulator can accurately adjust the output pressure value of the control fluid to the target pressure value.

The control valve for air supply and the control valve for exhaust used in such an electro-pneumatic regulator are required to open the control valve for supply or the control valve for exhaust when adjusting the output pressure value from the equilibrium state to the target pressure value. The duty ratio, which is the ratio of the period during which the operation is turned on (pulse period) and the time during which the valve opening operation is turned on (pulse width), is in a state where the duty ratio is large (i.e., a high duty ratio state). The action is repeated with high frequency.

Depending on the method of use, the air supply control valve and the exhaust control valve, which are repeatedly operated at high frequency, may malfunction in a short period of time after the start of use of the electro-pneumatic regulator. For example, if the high duty ratio state continues for a long time (excessive operation state) in the air supply control valve and the exhaust control valve, the life of the air supply control valve and the exhaust control valve will be shortened. As a result, the product life of the electropneumatic regulator is shortened. When an abnormality occurs in the air supply control valve and the exhaust control valve, the operator needs to replace the electropneumatic regulator with a new one.

2. Description of the Related Art An electro-pneumatic regulator disclosed in Patent Document 1 is known as an electro-pneumatic regulator that allows an operator to easily know that an abnormality has occurred in the electro-pneumatic regulator.

The electro-pneumatic regulator disclosed in Patent Literature 1 can display the operating state of the electro-pneumatic regulator with a two-color light-emitting element. For example, by providing a red LED and a green LED as light-emitting elements, when the operation of the electro-pneumatic regulator is in a stable state, only the green LED emits light to display green, and in an unstable state. In some cases, the red and green LEDs are illuminated to display an orange color, and in an abnormal state, only the red LED is illuminated to display a red color. It is possible to easily know the operating state of the electro-pneumatic regulator by the color displayed.

Japanese Patent No. 4615753

However, the above prior art has the following problems.
With the above electro-pneumatic regulator, it is possible to know whether the electro-pneumatic regulator in operation is in a stable state, an unstable state, or an abnormal state by means of two-color light-emitting elements. It is not possible to know the operation states of the air supply control valve and the exhaust control valve, which tend to malfunction in a short period of time. If the operation status of the air supply control valve and the exhaust control valve cannot be known, the operator may experience problems with the supply control valve and exhaust control valve in a short period of time, such as frequent repetition of excessive operation. You may not be able to notice the cause of the If the operator cannot notice the cause, the life of the electropneumatic regulator will be shortened, and the electropneumatic regulator will have to be replaced frequently. If the electro-pneumatic regulator is to be replaced frequently, for example, if the electro-pneumatic regulator is attached to the semiconductor manufacturing equipment, the operation of the semiconductor manufacturing equipment must be stopped in order to replace the electro-pneumatic regulator. However, if the electropneumatic regulator is replaced frequently, the production efficiency of semiconductors may be lowered.

SUMMARY OF THE INVENTION The present invention is intended to solve the above-mentioned problems, and it is possible to easily monitor the operation states of the air supply control valve and the exhaust control valve and prevent the life of the electro-pneumatic regulator from being shortened. It is an object of the present invention to provide an electropneumatic regulator that is

In order to solve the above problems, the electropneumatic regulator of the present invention has the following configuration .

(1) An electro-pneumatic regulator comprising an air supply control valve and an exhaust control valve that operate a main valve unit, and a control unit that controls the air supply control valve and the exhaust control valve, wherein the control unit is , an electro-pneumatic regulator that adjusts the output pressure value of the control fluid by controlling the supply control valve or the exhaust control valve based on the target pressure value instructed by the control device and operating the main valve unit , the control unit monitors the operating states of the air supply control valve and the exhaust control valve based on the pressure difference between the output pressure value and the target pressure value, and the pressure difference determines the target pressure value from the output pressure value. When the pressure difference is a positive value and is within the first predetermined range, the control unit controls the cycle in which the valve opening operation is turned on and the valve opening period. Judging that the duty ratio, which is the ratio of the time when the operation is on, is in a high duty ratio state, and when the pressure difference is a negative value and is within the second predetermined range, the control The control unit determines that the air supply control valve is in a high duty ratio state, and when the pressure difference is within the first predetermined range for a predetermined time or longer, the control unit determines that the exhaust control valve is in an excessive state. when the pressure difference is within a second predetermined range for a predetermined time or longer, the control unit determines that the air supply control valve is in an over-operating state; The time is longer than the duration, which is the time during which the high duty ratio state that cannot be avoided for the electro-pneumatic regulator to adjust the output pressure value based on the target pressure value is continued; The first predetermined range and the second predetermined range are characterized by being determined by the value of the pressure difference at the start of the duration and the value of the pressure difference at the end of the duration.

(3) In the electro-pneumatic regulator described in (2), the control unit includes a storage unit, and the storage unit stores the number of times the air supply control valve and the exhaust control valve are in the high duty ratio state and the high duty ratio state. It is characterized by storing the operation states of the air supply control valve and the exhaust control valve, including at least the length of time during which the duty ratio state has been maintained.

(4) In the electropneumatic regulator according to any one of (1) to (3), the electropneumatic regulator is connected to a control device via a master; is connected to the master through a star-type connection centering on the master of the field network.

The electro-pneumatic regulator of the present invention has the following functions and effects due to the above configuration.
According to the electropneumatic regulator described in (1), the control unit that controls the air supply control valve and the exhaust control valve controls the air supply control valve based on the pressure difference between the output pressure value and the target pressure value. Since it is possible to monitor the operating states of the air supply control valve and the exhaust control valve, even if the air supply control valve and the exhaust control valve are in an excessive operating state, the operator can notice it and prevent the excessive operation. It is possible to prevent the operating state from being repeated frequently. If it is possible to prevent frequent repetition of excessive operation, it is possible to prevent the life of the electro-pneumatic regulator from being shortened, which leads to prevention of frequent replacement of the electro-pneumatic regulator. If it is possible to prevent the electro-pneumatic regulator from being replaced frequently, the frequency of stopping the operation of the equipment to which the electro-pneumatic regulator is attached (for example, semiconductor manufacturing equipment) for the replacement of the electro-pneumatic regulator can be suppressed. It is possible to prevent a decrease in production efficiency (for example, production efficiency of semiconductors).

Furthermore, according to the electro-pneumatic regulator described in (1) , when either the air supply control valve or the exhaust control valve is in an excessive operation state, the pressure difference value determines whether the air supply control valve It becomes easy to monitor which of the exhaust control valves is in an over-operated state, and it is possible to prevent the life of the electro-pneumatic regulator from being shortened.

For example, an air supply control valve can be assumed to be in an unnecessary over-operated state if the electro-pneumatic regulator is operating while no control fluid is being supplied to the input port of the electro-pneumatic regulator. etc. can be considered. Since the control fluid is not supplied to the input port, the output pressure value at the output port does not reach the target pressure value. It will continue to operate in a high duty ratio state over time. As a result, the control valve for air supply ends up in an over-operated state. On the other hand, it is assumed that the exhaust control valve will be in an over-operated state when back pressure continues to be applied on the output port side of the electro-pneumatic regulator. In this case, since the exhaust control valve continues to operate in a high duty ratio state for a long time in an attempt to reduce the output pressure value, the exhaust control valve is in an excessive operation state. If it becomes easy to monitor which of the air supply control valve and the exhaust control valve is in an over-operated state, it will be easier for the operator to take countermeasures against the cause of the above-mentioned over-operated state. It is possible to prevent the life of the empty regulator from being shortened.

The excessive operation state includes the case where the electro-pneumatic regulator is used incorrectly, resulting in an unnecessarily high duty ratio state, and the case where the electro-pneumatic regulator is used unreasonably, resulting in a high duty ratio state. can be considered.

When the electro-pneumatic regulator is used incorrectly and the duty ratio becomes unnecessarily high, as described above, the electro-pneumatic regulator is not supplied with control fluid to the input port of the electro-pneumatic regulator. is operating or there is a constant back pressure on the output port side of the electro-pneumatic regulator.

On the other hand, when the electro-pneumatic regulator is used unreasonably and a high duty ratio state occurs, for example, when the electro-pneumatic regulator is used in a paint air blower used in painting work, It is conceivable that the flow rate of the sprayed paint is forcibly increased. FIG. 5 is a graph showing the relationship between the paint output pressure value P2 of the electropneumatic regulator in the air blower and the flow rate. The output pressure value P2 is adjusted by the electro-pneumatic regulator so as to reach the instructed target pressure value Pt2. However, when the operator increases the flow rate of the paint by, for example, increasing the throttle of the supply source of the paint, when the flow rate exceeds a certain flow rate F1, the output pressure value P2 cannot maintain the pressure. It decreases with respect to the target pressure value Pt2. When the output pressure value P2 decreases, the air supply control valve continues to operate in a high duty ratio state for a long time to increase the output pressure value P2 to the target pressure value Pt2. can be obtained, the control valve for air supply will be in an excessive operating state, and it can be said that the electro-pneumatic regulator is being used forcibly. Therefore, if the electro-pneumatic regulator of the present invention makes it easy to monitor which of the air supply control valve and the exhaust control valve is in an over-operated state, the operator will not be forced to use the electro-pneumatic regulator. can be noticed and countermeasures can be taken to prevent reduction of the life of the electro-pneumatic regulator.

According to the electropneumatic regulator described in (3), the storage unit includes at least the number of times the high duty ratio state has occurred and the length of time the high duty ratio state has occurred. Since the operating state of the control valve is stored, it is possible to accumulate information related to the operating state and use it as big data. It is possible to predict to some extent whether the life will be If it becomes possible to predict the life of the electro-pneumatic regulator, it will be possible to prevent unexpected abnormalities from occurring due to the end of the life of the electro-pneumatic regulator. If it is possible to prevent unexpected abnormalities due to the life of the electro-pneumatic regulator, it is possible to unexpectedly stop the operation of the equipment to which the electro-pneumatic regulator is attached (e.g., semiconductor manufacturing equipment) in order to replace the electro-pneumatic regulator. It is possible to prevent the possibility that the production efficiency (for example, the production efficiency of semiconductors) is lowered.

In addition, conventionally, in order to prevent the equipment to which the electro-pneumatic regulator is attached from stopping due to an unexpected abnormality occurring due to the life of the electro-pneumatic regulator, it is necessary to replace the electro-pneumatic regulator with a margin before the end of its life. Since it was exchanged for something else, the frequency of exchange increased. However, if the service life can be predicted as described above, the electro-pneumatic regulator can be used until the service life is nearly reached, and the frequency of replacement can be suppressed, thereby reducing costs.

According to the electro-pneumatic regulator described in (4), it is possible to easily monitor the operation states of the air supply control valves and the exhaust control valves of the plurality of electro-pneumatic regulators, thereby preventing the life of the electro-pneumatic regulators from being shortened. It is possible.

Multiple electro-pneumatic regulators are connected to the master through a star connection with a single master at the center to form a field network. and the operating state of the exhaust control valve can be collected by the master and transmitted to the control device. Therefore, it is possible to collectively manage the operation states of the air supply control valves and the exhaust control valves of the plurality of electropneumatic regulators. The operator can easily collectively know whether or not the air supply control valves and the exhaust control valves in the plurality of electro-pneumatic regulators are in a high duty ratio state, so that the malfunction in the plurality of electro-pneumatic regulators can be easily detected. Frequent repetition of the required high duty ratio state can be prevented. As a result, it is possible to prevent the life of the plurality of electropneumatic regulators from being shortened.

Here, the field network refers to IO-Link (registered trademark), for example. In conventional connection between a control device and an electro-pneumatic regulator, it was necessary to separately connect a cable for transmitting signals from the control device to the electro-pneumatic regulator and a cable for transmitting signals from the electro-pneumatic regulator to the control device. , IO-Link uses a 3-wire or 4-wire unshielded cable for the connection between the master and the electro-pneumatic regulator. can be performed mutually. Since it is sufficient to connect one cable between the single master and the controllers of the plurality of electropneumatic regulators, the factory layout can be simplified.

1 shows a field network configured using electropneumatic regulators; FIG. It is a circuit diagram of an electropneumatic regulator. 4 is a graph showing the relationship between PWM drive, output pressure value, and target pressure value. 4 is a graph showing the relationship between the pressure difference between the output pressure value and the target pressure value and time. It is a graph which shows the relationship between an output pressure value and a flow rate at the time of using an electropneumatic regulator for the air blow apparatus of paint.

An embodiment of the present invention will be described.
FIG. 1 is a diagram showing a field network configured using electropneumatic regulators 1A, 1B, and 1C according to this embodiment.
A field network is, for example, an IO-Link, and electropneumatic regulators 1A, 1B, and 1C are connected to a network controller 2 as a control device via a master 3. Electropneumatic regulators 1A, 1B, and 1C are connected to a single A star connection is made with the master 3 at the center. The number of electropneumatic regulators 1A, 1B, 1C is not limited to the three shown in FIG. Also, the number of masters 3 does not need to be one, and a plurality of masters 3 can be connected to the network controller 2 to provide a plurality of star connections centering on the masters 3 .

An unshielded cable having three wires or four wires is used for connection between the network controller 2, the master 3, and the electropneumatic regulators 1A, 1B, and 1C. It is possible to send and receive signals between them. Therefore, the network controller 2 can instruct the electro-pneumatic regulators 1A, 1B, and 1C of the target pressure value, and the electro-pneumatic regulators 1A, 1B, and 1C can notifies the network controller 2 that an abnormality has occurred, and in response to the notification, the network controller 2 changes the operating states stored in the electropneumatic regulators 1A, 1B, and 1C (for example, the electropneumatic regulator It refers to the operation state of the air supply control valve 12 and the exhaust control valve 13 provided in 1A, 1B, and 1C.Details will be described later.).

In conventional connection between a network controller and an electro-pneumatic regulator, it was necessary to separately connect a cable for transmitting signals from the network controller to the electro-pneumatic regulator and a cable for transmitting signals from the electro-pneumatic regulator to the network controller. , IO-Link uses a 3-wire or 4-wire unshielded cable as described above, so a single cable can connect the network controller 2 and the electro-pneumatic regulator 1A, electro-pneumatic regulator 1B or electro-pneumatic regulator 1C. and can exchange signals between them. Therefore, it becomes possible to simplify the factory layout.

The network controller 2 has a CPU, ROM, and RAM (not shown). The CPU temporarily stores data in the RAM according to a program stored in the ROM for controlling the electropneumatic regulators 1A, 1B, and 1C. The electro-pneumatic regulators 1A, 1B and 1C are controlled while storing the information. The control of the electropneumatic regulators 1A, 1B, and 1C performed by the network controller 2 means the pressure control in the electropneumatic regulators 1A, 1B, and 1C, such as instructing the target pressure values to the electropneumatic regulators 1A, 1B, and 1C. It refers to executing, or inquiring about the operating states stored in the electro-pneumatic regulators 1A, 1B, and 1C when an abnormality is detected in the electro-pneumatic regulators 1A, 1B, and 1C.

The master 3 is a unit for inputting and outputting signals, and the master 3 allows the network controller 2 and the plurality of electropneumatic regulators 1A, 1B, and 1C to exchange signals with each other without individual cable connection. Therefore, even if the distance between the network controller 2 and the electro-pneumatic regulators 1A, 1B, 1C is long, the wiring cost can be reduced.

Here, the electropneumatic regulators 1A, 1B, and 1C are all the same electropneumatic regulator, and will be simply referred to as electropneumatic regulator 1 hereinafter.
The electropneumatic regulator 1 is, for example, a fluid control device used in a dispenser device that discharges a chemical solution onto a wafer of a semiconductor manufacturing apparatus. an air supply control valve 12 and an exhaust control valve 13 controlled by 18, a main valve section 14 operated by the air supply control valve 12 and the exhaust control valve 13, and an input port 11 for inputting a control fluid. , and an output port 17 for outputting the control fluid.

The input port 11 and the output port 17 communicate with the main valve portion 14 . The input port 11 is connected to a supply source of control fluid and supplied with control fluid (for example, air). The main valve portion 14 has a valve body and a valve seat (not shown), and adjusts the output pressure value of the control fluid by contacting and separating the valve body and the valve seat. The output port 17 is connected to, for example, a syringe of the dispenser device, and outputs the control fluid controlled to the output pressure value to the syringe. The output pressure value is a value controlled based on the target pressure value indicated by the network controller 2 .

The air supply control valve 12 is connected to the input port 11 via an input flow path 21 and connected to a pilot chamber (not shown) of the main valve portion 14 via a flow path 24 . The air supply control valve 12 supplies air to the pilot chamber to operate the main valve portion 14 and controls the output pressure value at the output port 17 of the control fluid input to the input port 11 . A pressure sensor 16 is arranged in the output flow path 22 and detects the output pressure value of the control fluid at the output port 17 by the pressure sensor 16 .

The exhaust flow path 23 branches from the flow path 24 between the air supply control valve 12 and the main valve portion 14 and is connected to the exhaust port 15 open to the atmosphere. An exhaust control valve 13 is arranged in the exhaust flow path 23 . An exhaust port 15 communicates with the exhaust control valve 13, and the exhaust control valve 13 controls the control fluid that is exhausted from the pilot chamber of the main valve portion 14 to the exhaust port 15 through the flow path 24. do.

The control circuit 18 is electrically connected to the air supply control valve 12, the exhaust control valve 13, and the pressure sensor 16, respectively. The control circuit 18 is connected to the network controller 2 via the master 3 and receives from the network controller 2 instructions of a target pressure value, which is a target value of the output pressure value. The control circuit 18 controls the opening and closing of the air supply control valve 12 or the exhaust control valve 13 based on the target pressure value instructed by the network controller 2, and operates the main valve unit 14 to open the input port 11. adjusts the output pressure value at output port 17 of the control fluid input to .

In addition, the control circuit 18 stores a monitoring program for monitoring the operation states of the air supply control valve 12 and the exhaust control valve 13, and the air supply control valve 12 and the exhaust control valve 13 are operated for a long period of time. If an excessive operation state with a high duty ratio occurs, or if an abnormality occurs, it can be detected and notified to the network controller 2 . Details of the high duty ratio state and the excessive operation state will be described later.

Furthermore, the control circuit 18 is provided with a storage section 181 for storing the operating states of the air supply control valve 12 and the exhaust control valve 13 . Then, in response to a request from the network controller 2 , the stored operating states of the air supply control valve 12 and the exhaust control valve 13 are transmitted to the network controller 2 . Here, the stored operating states refer to the number of times the air supply control valve 12 and the exhaust control valve 13 have been in the high duty ratio state and the length of time during which they have been in the high duty ratio state.

The electro-pneumatic regulator 1 having such a configuration operates as follows.
When the electro-pneumatic regulator 1 receives the target pressure value from the network controller 2, the control circuit 18 detects the output pressure value detected by the pressure sensor 16 and compares it with the target pressure value. The control circuit 18 controls opening and closing of the air supply control valve 12 and the exhaust control valve 13 based on the pressure difference between the output pressure value and the target pressure value. Due to the opening/closing control of the air supply control valve 12 and the exhaust control valve 13, pressure fluctuations occur in the pilot chamber of the main valve portion 14, and the valve element of the main valve portion 14 is operated. As a result, the electropneumatic regulator 1 adjusts the output pressure value at the output port 17 of the control fluid input to the input port 11 so as to reach the target pressure value, and supplies the control fluid from the output port 17 to a syringe (not shown). .

Control of the opening and closing of the air supply control valve 12 and the exhaust control valve 13 by the control circuit 18 is performed by PWM driving. PWM drive means that the cycle T (see FIG. 3) in which the valve opening operation of the air supply control valve 12 or the exhaust control valve 13 is turned on is set constant, and the time during which the valve opening operation is turned on (pulse width Pw1 , Pw2, Pw3, Pw4, Pw5, Pw6 (see FIG. 3)). , control the opening and closing of the air supply control valve 12 and the exhaust control valve 13 .

The graph shown in FIG. 3 represents the relationship between the PWM drive, the output pressure value P, and the target pressure value Pt when the target pressure value is varied from 0 to P1.
The upper graph in FIG. 3 is a graph showing variations in the output pressure value and variations in the target pressure value, where the waveform P represents the output pressure value and the waveform Pt represents the target pressure value. The graph in the middle of FIG. 3 represents the PWM drive state of the air supply control valve 12 (indicated as an air supply valve in the drawing for convenience), and the graph in the lower part of FIG. 3 represents the exhaust control. The state of the PWM drive of the valve 13 (expressed as an exhaust valve in the drawing for convenience) is shown.

From time t0 to time t1, the target pressure value (waveform Pt) is 0 and the output pressure value (waveform P) is also 0, which is in equilibrium. At this time, the air supply control valve 12 and the exhaust control valve 13 are not operated.

For the electro-pneumatic regulator 1 in such a state, at time t1, the target pressure value (waveform Pt) is increased to P1 so that the output pressure value (waveform P) becomes P1. ) is input to the control circuit 18 . Then, the valve opening operation of the air supply control valve 12 is turned on, and the valve is first fully opened. As a result, the main valve portion 14 is operated, and the output pressure value (waveform P) begins to rise. At this stage, since the control valve 12 for air supply continues to be in the ON state, the operating state is stable and the load on the control valve 12 for air supply is not large.

A certain amount of time has passed since time t1, and the output pressure value (waveform P) needs to be finely adjusted from time t2 toward P1. becomes repeated. The period T during which the valve opening operation of the air supply control valve 12 is turned on is relatively long (pulse widths Pw1 and Pw2), that is, the duty ratio is large. It can be said that the air control valve 12 is in a high duty ratio state. Through such operations, the output pressure value (waveform P) gradually approaches P1.

The high duty ratio state of the air supply control valve 12 continues until time t3 when the output pressure value (waveform P) approaches P1. After that, when the output pressure value (waveform P) reaches P1 (time t4), the output pressure value (waveform P) is in an equilibrium state. After the time point t3, the operation of the air supply control valve 12 has a constant turn-on cycle T, but the pulse width Pw3 becomes smaller, so the duty ratio becomes smaller and the load on the air supply control valve 12 becomes smaller. Become.

Next, at time t5, the target pressure value (waveform Pt) is input so that the output pressure value (waveform P) is 0 as the target pressure value (waveform Pt) is 0. Then, the valve opening operation of the exhaust control valve 13 is turned on, and the exhaust control valve 13 is first fully opened. As a result, the main valve portion 14 is operated, and the output pressure value (waveform P) begins to drop. At this stage, since the exhaust control valve 13 continues to be in the ON state, the operating state is stable and the load on the exhaust control valve 13 is not large.

A certain amount of time has passed since time t5, and from time t6, the output pressure value (waveform P) needs to be finely adjusted toward 0. Therefore, the valve opening operation of the exhaust control valve 13 is turned on and off. becomes repetitive. With respect to the cycle T in which the valve opening operation of the exhaust control valve 13 is turned on, the period during which the exhaust control valve 13 is turned on (pulse widths Pw4 and Pw5) is relatively long, that is, the duty ratio is large. It can be said that the operating state of the control valve 13 is in a high duty ratio state. Through such operations, the output pressure value (waveform P) gradually approaches zero.

The high duty ratio state of the exhaust control valve 13 continues until time t7 when the output pressure value (waveform P) approaches zero. After that, when the output pressure value (waveform P) becomes 0, the output pressure value (waveform P) enters an equilibrium state. After time t7, the exhaust control valve 13 operates with a constant ON period T, but the pulse width Pw6 decreases, so the duty ratio decreases and the load on the exhaust control valve 13 decreases.

As described above, when the electro-pneumatic regulator 1 performs pressure control of the control fluid, it is unavoidable that the air supply control valve 12 and the exhaust control valve 13 are in a high duty ratio state. Since the burden on the air supply control valve 12 and the exhaust control valve 13 is large, if the excessive operation state in which the high duty ratio state is performed for a long time is repeated, , the air supply control valve 12 and the exhaust control valve 13 may malfunction.

For example, it is assumed that the air supply control valve 12 is in an unnecessary over-operated state because the electro-pneumatic regulator 1 operates even though the input port 11 of the electro-pneumatic regulator 1 is not supplied with control fluid. It is conceivable that the In this case, since the control fluid is not supplied to the input port 11, the output pressure value at the output port 17 does not reach the target pressure value. It continues to operate in a high duty ratio state for a long time in order to approach the pressure value. As a result, the air supply control valve 12 will be in an excessive operation state. On the other hand, it is assumed that the exhaust control valve 13 is in an over-operated state when back pressure continues to be applied on the output port 17 side of the electro-pneumatic regulator 1 . In this case, since the exhaust control valve 13 continues to operate in a high duty ratio state for a long time in an attempt to reduce the output pressure value, the exhaust control valve 13 will be in an excessive operation state.

Therefore, in order to prevent an abnormality in the air supply control valve 12 and the exhaust control valve 13 from occurring in a short period of time, it is monitored whether the air supply control valve 12 and the exhaust control valve 13 are in an excessive operating state. is required. Under such circumstances, the applicant found a certain relationship between the operating states of the air supply control valve 12 and the exhaust control valve 13 and the pressure difference between the output pressure value and the target pressure value. Therefore, the control circuit 18 of the electro-pneumatic regulator 1 according to the present embodiment uses a monitoring program for monitoring the operating states of the air supply control valve 12 and the exhaust control valve 13 to control the pressure between the output pressure value and the target pressure value. The operating states of the air supply control valve 12 and the exhaust control valve 13 are monitored based on the difference.

How to monitor the operating state will be specifically described below.
When the pressure difference is obtained by subtracting the target pressure value (waveform Pt) from the output pressure value (waveform P) shown in FIG. 3, the graph in FIG. waveform Pd.

In FIG. 3, from time t1 to time t4, the output pressure value (waveform P) is smaller than the target pressure value (waveform Pt), and from time t4 to time t5, the output pressure value (waveform P) and the target pressure Since the values (waveform Pt) are substantially the same, the pressure difference (waveform Pd) during operation of the air supply control valve 12 (from time t1 to time t5) is 0 as shown in FIG. It is below.

During the period from time t1 to time t5 when the air supply control valve 12 is in operation, the air supply control valve 12 from time t1 to time t2 is in a stable state as described above. It can be seen that the difference (waveform Pd) is within the range A3 from Pd5 to Pd6.

Further, the air supply control valve 12 from time t2 to time t3 is in a high duty ratio state with a large duty ratio as described above, and the pressure difference (waveform Pd) during this time is within the range A2 of Pd4 to Pd5. It can be seen that there is

Furthermore, from the time t3 to the time t5, the air supply control valve 12 is in a light load state with a small duty ratio as described above, and the pressure difference (waveform Pd) during this time is in the range A1 of 0 to Pd4. you know it's inside.

Therefore, when the value of the pressure difference (waveform Pd) is within the range A2, it indicates that the air supply control valve 12 is in the high duty ratio state.

On the other hand, in FIG. 3, from time t5 to time t8, the output pressure value (waveform P) is greater than the target pressure value (waveform Pt), and after time t8, the output pressure value (waveform P) and the target pressure value ( Since the waveform Pt) is substantially the same, the pressure difference (waveform Pd) is 0 or more as shown in FIG. 4 while the exhaust control valve 13 is operating (after time t5). .

After time t5 when the exhaust control valve 13 is in operation, the exhaust control valve 13 from time t5 to time t6 is in a stable state as described above, and the pressure difference (waveform Pd) during this period is It can be seen that it is within the range A6 from Pd2 to Pd3.

As described above, the exhaust control valve 13 from time t6 to time t7 is in a high duty ratio state with a large duty ratio, and the pressure difference (waveform Pd) during this time is within the range A5 of Pd1 to Pd2. I know there is.

Furthermore, after time t8, the exhaust control valve 13 is in a light load state with a small duty ratio as described above, and the pressure difference (waveform Pd) during this time is within the range A4 of 0 to Pd1. I understand.

Therefore, when the value of the pressure difference (waveform Pd) is within the range A5, it indicates that the exhaust control valve 13 is in the high duty ratio state.

As described above, since a certain relationship can be found between the pressure difference (waveform Pd) and the operation states of the air supply control valve 12 and the exhaust control valve 13, the electropneumatic regulator according to the present embodiment 1 control circuit 18, when the pressure difference (waveform Pd) calculated by subtracting the target pressure value (waveform Pt) from the output pressure value (waveform P) is positive and within range A5, Judging that the exhaust control valve 13 is in a high duty ratio state, and the pressure difference is a negative value and is within the range A2, it is judged that the air supply control valve 12 is in a high duty ratio state. It is assumed that

Then, when it is determined that the air supply control valve 12 or the exhaust control valve 13 is in the high duty ratio state, the time for which the high duty ratio state continues is monitored, and the high duty ratio state exceeds the predetermined time. , it is determined that the air supply control valve 12 or the exhaust control valve 13 is in an excessive operation state. It should be noted that the predetermined time is a high duty ratio state that cannot be avoided in operating the electro-pneumatic regulator 1, such as between time t2 and time t3 and between time t6 and time t7 in FIG. This time is longer than the continuous time, and is appropriately set according to the specifications of the electro-pneumatic regulator 1 .

In addition, the storage unit 181 provided in the control circuit 18 stores the number of times the air supply control valve 12 and the exhaust control valve 13 are in the high duty ratio state and the length of time in the high duty ratio state. Store state. Therefore, the electro-pneumatic regulator 1 can not only notify the electro-pneumatic regulator 1 that an abnormality has occurred, but also notify the network controller 2 of the stored operating state. For example, the network controller 2 that has received the notification of the occurrence of an abnormality makes a specific inquiry about the operating state to the control circuit 18, and as a reply, transmits the operating state stored in the storage unit 181 to the network controller 2. be able to.

If the transmitted operating state is stored, the number of times the electro-pneumatic regulator 1 with an abnormality has entered the high duty ratio state and the length of time during which the high duty ratio state has been maintained can be used as big data. It is possible to predict the life of the electro-pneumatic regulator 1 to some extent based on the number of high duty ratio states and the length of time in the high duty ratio state. If the life expectancy can be predicted, it is possible to prevent unexpected abnormalities from occurring due to the end of the life of the electro-pneumatic regulator 1 . It is possible to prevent the possibility of unexpectedly stopping the operation of the semiconductor manufacturing apparatus to which the electro-pneumatic regulator 1 is attached in order to replace the electro-pneumatic regulator 1, and to prevent the production efficiency of semiconductors from being lowered. .

Moreover, if the service life can be predicted as described above, the electro-pneumatic regulator 1 can be used until the service life is nearing the end, and the frequency of replacement can be reduced, thereby reducing costs.

As described above, according to the electropneumatic regulator 1 of this embodiment,
(1) Provided with an air supply control valve 12 and an exhaust control valve 13 that operate the main valve section 14, and a control section (control circuit 18) that controls the air supply control valve 12 and the exhaust control valve 13. In the electro-pneumatic regulator 1, a control section (control circuit 18) controls the air supply control valve 12 or the exhaust control valve 13 based on the target pressure value indicated by the control device (network controller 2). In the electro-pneumatic regulator 1 that adjusts the output pressure value of the control fluid by operating the main valve portion 14, the control portion (control circuit 18) operates based on the pressure difference between the output pressure value and the target pressure value. Since it is characterized by monitoring the operation states of the air supply control valve 12 and the exhaust control valve 13, the control unit (control circuit 18) that controls the air supply control valve 12 and the exhaust control valve 13 is Since it is possible to monitor the operation states of the air supply control valve 12 and the exhaust control valve 13 based on the pressure difference between the output pressure value and the target pressure value, In the valve 13, even if unnecessary high duty ratio is performed, the operator can notice it, and can prevent unnecessary high duty ratio from being repeated frequently. If it is possible to prevent frequent repetition of unnecessary high duty ratios, it is possible to prevent the life of the electro-pneumatic regulator 1 from being shortened. lead to prevention. If it is possible to prevent the replacement of the electro-pneumatic regulator 1 from becoming too frequent, the frequency of stopping the operation of a device (for example, a semiconductor manufacturing device) to which the electro-pneumatic regulator 1 is attached to replace the electro-pneumatic regulator 1 can be suppressed, and a decrease in production efficiency (for example, production efficiency of semiconductors) can be prevented.

(2) In the electropneumatic regulator 1 described in (1), the pressure difference is calculated by subtracting the target pressure value from the output pressure value, the pressure difference is a positive value, and is within the first predetermined range. When it is in A2, the control unit (control circuit 18) controls the exhaust control valve 13 so that the duty ratio is Determining that it is in a large high duty ratio state, the pressure difference is a negative value, and when it is within the second predetermined range A4, the control unit (control circuit 18) determines that the air supply control valve 12 is , determining that the exhaust control valve 13 is in the high duty ratio state, and when the exhaust control valve 13 is in the high duty ratio state for a predetermined time or longer, the control unit (control circuit 18) determines that the exhaust control valve 13 is in the excessive operation state When the air supply control valve 12 is in a high duty ratio state for a predetermined time or longer, the control unit (control circuit 18) determines that the air supply control valve 12 is in an excessive operation state Since it is characterized by judging, when either the air supply control valve 12 or the exhaust control valve 13 is in a high duty ratio state, depending on the value of the pressure difference, the air supply control valve 12 and the exhaust It becomes easy to monitor which one of the control valves 13 for high duty ratio is in the high duty ratio state.

For example, it is assumed that the air supply control valve 12 is in an over-operated state because the electro-pneumatic regulator 1 is operating even though the input port 11 of the electro-pneumatic regulator 1 is not supplied with control fluid. Such cases can be considered. Although the output pressure value at the output port 17 does not reach the target pressure value because the control fluid is not supplied to the input port 11, the air supply control valve 12 brings the output pressure value closer to the target pressure value. However, it continues to operate in a high duty ratio state for a long time. As a result, the air supply control valve 12 will be in an excessive operation state. On the other hand, it is assumed that the exhaust control valve 13 is in an over-operated state when back pressure continues to be applied on the output port 17 side of the electro-pneumatic regulator 1 . In this case, since the exhaust control valve 13 continues to operate in a high duty ratio state for a long time in an attempt to reduce the output pressure value, the exhaust control valve 13 will be in an excessive operation state. If it becomes easy to monitor which of the air supply control valve 12 and the exhaust control valve 13 is in the over-operated state, it will be easier for the operator to take countermeasures against the cause of the over-operated state as described above. Become. Therefore, it becomes possible to prevent the life of the electro-pneumatic regulator 1 from being shortened.

(3) In the electro-pneumatic regulator 1 described in (2), the control section (control circuit 18) includes a storage section 181, and the storage section 181 stores the air supply control valve 12 and the exhaust control valve 13 in high It is characterized by storing the operation states of the air supply control valve 12 and the exhaust control valve 13, including at least the number of times the duty ratio state has occurred and the length of time the high duty ratio state has occurred. The operating states of the air supply control valve 12 and the exhaust control valve 13 are stored in the storage unit 181, including at least the number of times the high duty ratio state has occurred and the length of time the high duty ratio state has occurred. Therefore, by accumulating information about the operating state, it is possible to make big data, and from the big data, it is possible to predict to some extent how many times the high duty ratio state will be repeated until the end of the life of the electro-pneumatic regulator 1. It becomes possible to If it becomes possible to predict the service life, it is possible to prevent unexpected abnormalities from occurring due to the service life of the electro-pneumatic regulator 1 . If it is possible to prevent the occurrence of an unexpected abnormality due to the life of the electro-pneumatic regulator 1, the operation of a device (for example, a semiconductor manufacturing device) to which the electro-pneumatic regulator 1 is attached can be expected for replacement of the electro-pneumatic regulator 1. In this way, it is possible to prevent the possibility of stopping the production process without fail, and to prevent a decrease in production efficiency (for example, production efficiency of semiconductors).

Moreover, if the service life can be predicted as described above, the electro-pneumatic regulator 1 can be used until the service life is nearing the end, and the frequency of replacement can be reduced, thereby reducing costs.

(4) In the electropneumatic regulator 1 according to any one of (1) to (3), the electropneumatic regulator 1 is connected to a control device (network controller 2) via a master 3; are connected to the master 3 through a star connection centering on a single master 3 to form a field network. It is possible to easily monitor the operating states of the air control valve 12 and the exhaust control valve 13 and prevent the life of the electro-pneumatic regulator 1 from being shortened.

A plurality of electro-pneumatic regulators 1 are connected to the master 3 through a star connection centering on a single master 3 to form a field network. ) can be collected by the master 3 and transmitted to the control device (network controller 2). Therefore, the operating states of the air supply control valves 12 and the exhaust control valves 13 of the plurality of electropneumatic regulators 1 can be easily collectively managed. The operator can easily collectively know whether or not the air supply control valves 12 and the exhaust control valves 13 in the plurality of electropneumatic regulators 1 are in the high duty ratio state. Frequent repetition of an unnecessary high duty ratio state in the regulator 1 can be prevented. Thereby, it is possible to prevent the life of the plurality of electropneumatic regulators 1 from being shortened.

Here, the field network refers to IO-Link (registered trademark), for example. In conventional connection between a control device and an electro-pneumatic regulator, it was necessary to separately connect a cable for transmitting signals from the control device to the electro-pneumatic regulator and a cable for transmitting signals from the electro-pneumatic regulator to the control device. , IO-Link uses a 3-wire or 4-wire unshielded cable for the connection between the master 3 and the electro-pneumatic regulator 1. signals can be exchanged with each other. Since it is sufficient to connect one cable between the single master 3 and the control units (control circuits 18) of the plurality of electropneumatic regulators 1, the factory layout can be simplified. .

It should be noted that the above-described embodiment is merely an example, and does not limit the present invention in any way. Therefore, the present invention can naturally be improved and modified in various ways without departing from the scope of the invention.
For example, in the above embodiment, the electro-pneumatic regulator 1 is a fluid control device used in a dispenser device of a semiconductor manufacturing apparatus, but it is not limited to this and can be used in other pneumatic control devices. It is possible.

1 electropneumatic regulator 2 network controller (an example of a control device)
11 Input port 12 Air supply control valve 13 Exhaust control valve 14 Main valve section 17 Output port 18 Control circuit (an example of control section)

Claims (3)

An electro-pneumatic regulator comprising: an air supply control valve and an exhaust control valve that operate a main valve unit; and a control unit that controls the air supply control valve and the exhaust control valve, wherein the control unit is , based on the target pressure value instructed from the control device, the control valve for air supply or the control valve for exhaust is controlled, by operating the main valve portion, the electric power that adjusts the output pressure value of the control fluid In an empty regulator,
wherein the control unit monitors operating states of the air supply control valve and the exhaust control valve based on a pressure difference between the output pressure value and the target pressure value;
the pressure difference is calculated by subtracting the target pressure value from the output pressure value;
When the pressure difference is a positive value and is within a first predetermined range, the control unit controls the cycle in which the exhaust control valve is turned on and the valve opening operation is turned on. Determining that it is in a high duty ratio state in which the duty ratio, which is the ratio of the time it is held, is large,
When the pressure difference is a negative value and is within a second predetermined range, the control unit determines that the air supply control valve is in the high duty ratio state;
when the pressure difference is within a first predetermined range for a predetermined time or longer, the control unit determines that the exhaust control valve is in an over-operating state;
when the pressure difference is within a second predetermined range for a predetermined time or longer, the control unit determines that the air supply control valve is in an over-operating state;
The predetermined time is longer than the duration of the high duty ratio state that cannot be avoided for the electro-pneumatic regulator to adjust the output pressure value based on the target pressure value . to be,
The first predetermined range and the second predetermined range are determined by the value of the pressure difference at the start of the duration and the value of the pressure difference at the end of the duration;
An electropneumatic regulator characterized by: The electropneumatic regulator of claim 1, wherein
The control unit comprises a storage unit;
The storage unit stores at least the number of times that the air supply control valve and the exhaust control valve are in the high duty ratio state and the length of time that the high duty ratio state has been in the air supply. storing the operating states of the exhaust control valve and the exhaust control valve;
An electropneumatic regulator characterized by: The electropneumatic regulator according to claim 1 or 2,
the electropneumatic regulator is connected to the control device via a master;
a plurality of the electropneumatic regulators are connected to the master through a star connection centering on the single master to form a field network;
An electropneumatic regulator characterized by:

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