Motor valve control device

Abstract

To reduce the size and cost of a system.SOLUTION: A pulse converter 1 includes an analog input part 2 into which a signal showing the valve opening of an electronic expansion valve 10 is input, a micro computer 3 for converting a signal showing the valve opening of the electronic expansion valve 10 into a driving pulse which drives the electronic expansion valve, an electronic expansion valve drive circuit 4 for driving the electronic expansion valve 10 on the basis of the driving pulse, and a power source circuit A5 for insulating the analog input part 2, the micro computer 3 and the electronic expansion valve drive circuit 4 from a supply power source 30, and creating a predetermined voltage on the basis of a voltage supplied from the supply power source 30, to be supplied to the analog input part 2, the micro computer 3 and the electronic expansion valve drive circuit 4.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an electric valve control device for controlling the valve opening of an electric valve such as an electronic expansion valve. [Background technology]

[0002] For example, motor-operated valves such as electronic expansion valves are used in refrigerators and chillers for semiconductor manufacturing equipment, etc. This type of motor-operated valve can perform precise opening and closing control by using a stepping motor.

[0003] Such motor-operated valves are driven and controlled by converting an analog signal output from a control device such as a temperature regulator into a pulse signal by a pulse drive device (also called a pulse output unit or pulse converter) (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2011-220451 A Summary of the Invention [Problem to be solved by the invention]

[0005] For example, if multiple motor-operated valves are required due to multiple temperature adjustment points, multiple pulse drive devices are also required. Therefore, it is possible to share an external power source to supply power to multiple pulse drive devices. However, if the external power source is shared, disturbances such as noise generated in the external power source will propagate to and affect all pulse drive devices and motor-operated valves. Furthermore, disturbances generated in a specific motor-operated valve or pulse drive device will propagate through the power line to and affect other pulse drive devices and other motor-operated valves.

[0006] Details will be described with reference to the drawings. Fig. 3 shows an example of a configuration in which an external power source is shared to supply power to a plurality of pulse driving devices. In Fig. 3, reference numerals 100A, 100B, and 100C denote pulse driving devices, and reference numerals 101A, 101B, and 101C denote motor-operated valves (e.g., electronic expansion valves). The pulse driving device 100A drives the motor-operated valve 101A, the pulse driving device 100B drives the motor-operated valve 101B, and the pulse driving device 100C drives the motor-operated valve 101C. Reference numeral 102 denotes an external power source. The external power source 102 is connected to the pulse driving devices 100A, 100B, and 100C by a junction wiring.

[0007] In the configuration of Fig. 3, when a disturbance occurs on the external power supply 102A side, the disturbance propagates through the power line to the pulse drive devices 100A, 100B, 100C and the motor-operated valves 101A, 101B, 101C (left side of Fig. 3). On the other hand, when a disturbance occurs on the load side (pulse drive devices and motor-operated valves), the disturbance propagates through the power line to the external power supply 102, other pulse drive devices and motor-operated valves (right side of Fig. 3). The diagram on the right side of Fig. 3 shows that a disturbance generated in the motor-operated valve 101A propagates to the pulse drive device 100A, other pulse drive devices, other motor-operated valves and the external power supply 102.

[0008] Conventionally, this has been dealt with by providing separate external power supplies as shown in Fig. 4. In Fig. 4, external power supply 102A is dedicated to pulse driver 100A, external power supply 102B is provided for pulse driver 100B, and external power supply 102C is provided for pulse driver 100C. By doing this, even if a disturbance occurs on the external power supply 102A side, it does not affect pulse driver 100B, 100C and motor-operated valves 101B, 101C (left side of Fig. 4). On the other hand, even if a disturbance occurs on motor-operated valve 101A, it does not affect pulse driver 100B, 100C and motor-operated valves 101B, 101C (right side of Fig. 4).

[0009] However, providing separate external power supplies as shown in FIG. 4 increases the number of power supply devices, leading to an increase in the size of the system and an increase in costs.

[0010] SUMMARY OF THE PRESENT EMBODIMENT An object of the present invention is to reduce the size and cost of the system. [Means for solving the problem]

[0011] The invention made to solve the above problems is characterized by comprising an input circuit unit to which a signal indicating the valve opening of an electric valve is input, a control unit that converts the signal into an opening signal of the electric valve via the input circuit unit, a drive circuit that drives the electric valve based on the opening signal, and an isolated power supply circuit that insulates the input circuit unit, the control unit, and the drive circuit from an external power source, and generates a predetermined voltage based on a voltage supplied from the external power source and supplies it to the input circuit unit, the control unit, and the drive circuit. Effect of the Invention

[0012] According to the present invention, the input circuit, the control unit, and the drive circuit are isolated from the external power supply by the isolated power supply circuit, so that disturbances are not propagated to other motor-operated valve control devices or motor-operated valves via the power supply lines. Therefore, the number of external power supplies can be reduced by sharing them, and the system can be made smaller and less expensive. [Brief description of the drawings]

[0013] [Figure 1] 1 is a schematic configuration diagram of a system including an electric valve control device according to an embodiment of the present invention. [Diagram 2] 2 is an explanatory diagram of the operation of a system including the motor-operated valve control device shown in FIG. 1. [Diagram 3] 1 is a diagram illustrating a problem in a conventional motor-operated valve control device. [Figure 4] FIG. 1 is an explanatory diagram of a method for solving a conventional problem. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An electric valve control device according to an embodiment of the present invention will be described below. Fig. 1 is a schematic diagram of an electric valve control system including the electric valve control device according to the present embodiment.

[0015] The motor-operated valve control system shown in Fig. 1 includes a pulse converter 1, an electronic expansion valve 10, a setting device 20, and a power supply 30. In Fig. 1, two pulse converters 1 are shown, reference numerals 1A and 1B, but three or more may be provided. Two electronic expansion valves 10 are shown, reference numerals 10A and 10B. Two setting devices 20 are shown, reference numerals 20A and 20B. Like the pulse converters 1, three or more electronic expansion valves 10 and setting devices 20 may be provided.

[0016] The pulse converter 1 functions as the motor-operated valve control device according to this embodiment. The pulse converter 1 includes an analog input unit 2, a microcomputer 3, an electronic expansion valve drive circuit 4, a power supply circuit A5, a power supply circuit B6, and a power supply circuit C7.

[0017] The analog input unit 2 includes an I / V conversion circuit that converts a signal current indicating the valve opening of the motor-operated valve input from the setting device 20 into a voltage, and an operational amplifier circuit that converts the voltage converted by the I / V conversion circuit into a voltage value suitable for the microcomputer 3. In other words, the analog input unit 2 functions as an input circuit unit to which a signal indicating the valve opening of the electronic expansion valve 10 (motor-operated valve) is input.

[0018] The microcomputer 3 is a microcomputer equipped with an A / D conversion circuit, a CPU (Central Processing Unit), an I / O circuit, a ROM (Read Only Memory), and a RAM (Random Access Memory). The microcomputer 3 converts the valve opening signal, which has been converted into a digital signal by the A / D conversion circuit, into a drive pulse for driving the electronic expansion valve 10, and controls the valve opening of the electronic expansion valve 10 via the I / O circuit and the electronic expansion valve drive circuit 4. In other words, the microcomputer 3 functions as a control unit that converts a signal current (a signal indicating the valve opening of the motor-operated valve) into a drive pulse (pulse signal) for driving the electronic expansion valve 10.

[0019] The electronic expansion valve drive circuit 4 drives the electronic expansion valve 10 and controls the valve opening degree based on the drive pulse output from the microcomputer 3. That is, the electronic expansion valve drive circuit 4 functions as a drive circuit that drives the motor-operated valve based on the drive pulse (pulse signal).

[0020] The power supply circuit A5 supplies a voltage of DC 24V supplied from the power supply 30, which is an external power source, to the power supply circuit B6, the power supply circuit C7, etc. The power supply circuit A5 is configured as an isolated power supply circuit that insulates the power supply 30 side (primary side) from the internal circuit side (secondary side) of the power supply circuit B6, etc. Specifically, the power supply circuit A5 can be configured as an isolated DC / DC converter.

[0021] In other words, the power supply circuit A5 functions as an isolated power supply circuit that insulates the analog input unit 2 (input circuit), the microcomputer 3 (control unit), and the electronic expansion valve drive circuit 4 (drive circuit) from the power supply 30 (external power source), and generates a predetermined voltage based on the voltage supplied from the power supply 30 (external power source), and supplies it to the analog input unit 2 (input circuit), the microcomputer 3 (control unit), and the electronic expansion valve drive circuit 4 (drive circuit).

[0022] The power supply circuit B6 converts the voltage supplied from the power supply circuit A5 to DC 12 V and outputs the converted DC 12 V. The DC 12 V converted by the power supply circuit B6 is supplied to the electronic expansion valve 10, for example.

[0023] The power supply circuit C7 converts the voltage supplied from the power supply circuit B6 to DC 5 V and outputs the converted DC 5 V. The DC 5 V converted by the power supply circuit C7 is supplied to the microcomputer 3, for example.

[0024] The electronic expansion valve 10 is one form of the motor-operated valve in this embodiment. The electronic expansion valve 10 is provided in, for example, a refrigerator or a chiller for semiconductor manufacturing equipment. The electronic expansion valve 10 has a stepping motor as described above, and is controlled to open and close by the pulse converter 1.

[0025] The setting device 20 is a device that sets the valve opening degree in the pulse converter 1, and outputs a signal current that indicates the opening degree of the motor-operated valve. The setting device 20 can be configured as a temperature regulator that outputs a control signal such as a valve opening degree based on a temperature measured at a predetermined location in, for example, a refrigerator or a chiller for semiconductor manufacturing equipment. The setting device 20 can also be configured as, for example, a PLC (Programmable Logic Controller).

[0026] The power supply 30 is an external power supply and supplies DC 24V to the pulse converter 1. The power supply 30 and the pulse converters 1A and 1B are connected by a power line PL via a jumper wiring.

[0027] The operation of the motor-operated valve control system having the above-mentioned configuration will be described with reference to Fig. 2. Fig. 2 is a simplified version of the configuration shown in Fig. 1, as shown in Figs. 3 and 4. The pulse converter 1C shown in Fig. 2 has the same configuration as the pulse converters 1A and 1B shown in Fig. 1, and the electronic expansion valve 10C shown in Fig. 2 has the same configuration as the electronic expansion valves 10A and 10B shown in Fig. 1. The setting device 20 shown in Fig. 1 is not shown.

[0028] As described above, the primary side and secondary side of the pulse converter 1 are electrically insulated by the power supply circuit A5. Therefore, even if a disturbance occurs in the power supply 30, it does not propagate to the secondary side. Therefore, it is possible to prevent the disturbance from propagating to the internal circuits of the pulse converter 1, such as the analog input unit 2, the microcomputer 3, and the electronic expansion valve drive circuit 4, and the electronic expansion valve 10 (left side of FIG. 2).

[0029] On the other hand, even if a disturbance occurs in the electronic expansion valve 10A, the disturbance is prevented from propagating to the primary side by the power supply circuit A5. Therefore, the disturbance can be prevented from propagating to the pulse converters 1B and 1C and the electronic expansion valves 10B and 10C connected by the power supply 30 and the power line PL (Figure 2, right).

[0030] According to this embodiment, the pulse converter 1 includes an analog input unit 2 to which a signal indicating the valve opening of the electronic expansion valve 10 is input, a microcomputer 3 that converts the signal indicating the valve opening of the electronic expansion valve 10 into a drive pulse for driving the electronic expansion valve, and an electronic expansion valve drive circuit 4 that drives the electronic expansion valve 10 based on the drive pulse. The pulse converter 1 further includes a power supply circuit A5 that insulates the analog input unit 2, the microcomputer 3, and the electronic expansion valve drive circuit 4 from a power supply 30, and generates a predetermined voltage based on the voltage supplied from the power supply 30 and supplies it to the analog input unit 2, the microcomputer 3, and the electronic expansion valve drive circuit 4.

[0031] By configuring the pulse converter 1 as described above, the analog input unit 2, the microcomputer 3, and the electronic expansion valve drive circuit 4 are insulated from the power supply 30 by the power supply circuit A5, so that disturbances are not propagated to other pulse converters 1 or electronic expansion valves 10 via the power supply line PL. Therefore, the number of power supplies 30 can be reduced by sharing them, and the system can be made smaller and less expensive.

[0032] In addition, because it is composed of an isolated DC / DC converter, it is possible to reduce costs by using existing components without having to design special circuits.

[0033] The present invention is not limited to the above-described embodiment. In other words, a person skilled in the art can implement various modifications according to conventional knowledge without departing from the gist of the present invention. As long as the configuration of the motor-operated valve control device of the present invention is still included in the scope of the present invention even after such modifications, the modifications are of course included in the scope of the present invention. [Explanation of symbols]

[0034] 1 Pulse converter (motor valve control device) 2 Analog input section (input circuit section) 3 Microcomputer (control unit) 4. Electronic expansion valve drive circuit (drive circuit) 5 Power supply circuit A (isolated power supply circuit, isolated DC / DC converter) 10 Electronic expansion valve (motorized valve)

Claims

1. an input circuit section to which a signal indicating a valve opening degree of the motor-operated valve is input; a control unit that converts a signal indicating a valve opening degree of the motor-operated valve into a pulse signal that drives the motor-operated valve; a drive circuit that drives the motor-operated valve based on the pulse signal; an isolated power supply circuit that insulates the input circuit unit, the control unit, and the drive circuit from an external power supply, generates a predetermined voltage based on a voltage supplied from the external power supply, and supplies the predetermined voltage to the input circuit unit, the control unit, and the drive circuit; An electric valve control device comprising:

2. 2. The motor-operated valve control device according to claim 1, wherein the isolated power supply circuit is formed of an isolated DC / DC converter.

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