Motor-operated valve control apparatus

Abstract

To enable easy update of a control program.SOLUTION: A controller 1 includes: a control microcomputer 6 which controls opening / closing of an electronic expansion valve 24 using a control program 71 based on temperature data and pressure data, to control a degree of superheat of a refrigeration cycle system; and a communication circuit 2 which receives an update program 151 from the outside. The control microcomputer 6 holds the electronic expansion valve 24 in a fully closed state during updating the control program 71 to the update program 151.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a control device for an electrically operated valve such as an electronic expansion valve, for example a superheat controller. [Background technology]

[0002] Conventionally, refrigeration devices using an electronic expansion valve have been known. This type of refrigeration device calculates the difference (degree of superheat) between the temperature on the outlet side of an evaporator and the temperature on the inlet side of the evaporator in a refrigeration cycle system of the refrigeration device, and controls the opening degree of the electronic expansion valve by, for example, PID control according to the deviation between the measured value of the degree of superheat and a set value (target value) of the degree of superheat (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 4672001 Summary of the Invention [Problem to be solved by the invention]

[0004] The control of motor-operated valves such as the electronic expansion valve described above is often performed by a control program executed by a microcomputer, etc. Furthermore, this type of control program may be updated to add functions, correct defects, etc.

[0005] However, updating of the control program in such a control device for the motor-operated valve has been performed manually when the system has stopped, etc., which is time-consuming.

[0006] To avoid such trouble, it is possible to automatically update the control program, but depending on the state of the motor-operated valve when the system is stopped, this may affect other devices such as the compressor that constitutes the refrigeration cycle system. Therefore, simply updating the control program automatically when the system is stopped may not be sufficient.

[0007] SUMMARY OF THE PRESENT EMBODIMENT An object of the present invention is to easily update a control program without affecting other devices that configure a refrigeration cycle system. [Means for solving the problem]

[0008] The invention made to solve the above problems comprises a control unit that controls the superheat degree of a refrigeration cycle system by controlling the opening and closing of an electric valve using a control program based on at least temperature information, a receiving unit that receives a new control program from the outside, and an updating unit that updates the control program to the new control program, and is characterized in that the control unit holds the electric valve in a predetermined state while the updating unit is performing the update. Effect of the Invention

[0009] According to the present invention, by maintaining the electric valve in a predetermined state, the control program can be updated without affecting other equipment that constitutes the refrigeration cycle system, for example, when updating the control program or when restarting after termination. [Brief description of the drawings]

[0010] [Figure 1] 1 is a diagram showing an example of a refrigeration device using an electronic expansion valve as a motor-operated valve according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a schematic configuration diagram of a system centered around a controller shown in FIG. 1. [Diagram 3] 3 is a flowchart of an update operation of the controller shown in FIG. 2; [Figure 4] 3 is a flowchart of an update operation of the controller shown in FIG. 2; [Diagram 5] 3 is a diagram showing a modified example of a method of using the EEPROM shown in FIG. 2. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] A superheat controller and a motor-operated valve control circuit according to one embodiment of the present invention will be described below. Fig. 1 is a diagram showing an example of a refrigeration device using an electronic expansion valve as the motor-operated valve according to this embodiment.

[0012] As shown in FIG. 1, the cooling device includes an evaporator 21 installed in a freezer 20, a compressor and a condenser in a refrigerator 22, a liquid supply solenoid valve 23, and an electronic expansion valve 24, which are connected in a ring shape by piping to form a well-known refrigeration cycle.

[0013] In Figure 1, reference numeral 25 denotes an evaporator outlet temperature sensor that measures the temperature on the outlet side of the evaporator 21, reference numeral 26 denotes an evaporator inlet temperature sensor that measures the temperature on the inlet side of the evaporator 21, and reference numeral 27 denotes an inside temperature sensor that measures the temperature inside the freezer 20, and the measurement signals from these sensors are input to the controller 1.

[0014] The controller 1 has a control unit such as a microcomputer, a drive circuit for the electronic expansion valve, a memory, a display unit, an operation unit, etc., and calculates the difference (degree of superheat) between the evaporator outlet temperature measured by the evaporator outlet temperature sensor 25 and the evaporator inlet temperature measured by the evaporator inlet temperature sensor 26, and outputs an operation signal to the electronic expansion valve 24 to control the opening degree of the electronic expansion valve 24 by PID control according to the deviation between the measured value of the superheat and a set value (target value) of the superheat. The controller 1 is also called a superheat controller.

[0015] Fig. 2 shows a schematic configuration diagram of the controller 1 shown in Fig. 1. As shown in Fig. 1, the controller 1 includes a communication circuit 2, a measurement circuit 3, a drive circuit 4, a contact detection circuit 5, a control microcomputer 6, and an EEPROM 7.

[0016] The communication circuit 2 communicates with a user PC 15, which will be described later, for example, by serial communication. The communication circuit 2 receives an updated version (new control program) of the control program of the control microcomputer 6 from the user PC 15, and outputs it to the control microcomputer 6. That is, the communication circuit 2 functions as a receiving unit that receives the new control program from the outside.

[0017] A temperature sensor 11 and a pressure sensor 12, which will be described later, are connected to the measurement circuit 3. The measurement circuit 3 outputs signals input from the temperature sensor 11 and the pressure sensor 12 to the control microcomputer 6 as temperature data and pressure data.

[0018] The drive circuit 4 outputs a drive signal for driving the electronic expansion valve 24 based on an excitation signal or the like from the control microcomputer 6. The drive circuit 4 can be configured as, for example, a constant current chopper drive circuit.

[0019] The contact detection circuit 5 receives an operation instruction from a start input 13, which will be described later. That is, the contact detection circuit 5 functions as an input unit to which information related to the operation instruction is input from a higher-level device. The contact detection circuit 5 outputs the input operation instruction to the control microcomputer 6. An operation instruction can be, for example, start or stop, and an "ON" operation instruction indicates start, and an "OFF" operation instruction indicates stop.

[0020] The control microcomputer 6 is responsible for the overall control of the controller 1. The control microcomputer 6 generates an excitation signal for controlling the opening degree of the electronic expansion valve 24 based on the temperature data and pressure data input from the measurement circuit 3, and outputs the excitation signal to the drive circuit 4. The control microcomputer 6 also performs the above-mentioned overall control and drives the electronic expansion valve 24 according to a control program 71 stored in the EEPROM 7. That is, the control microcomputer 6 functions as a control unit that controls the degree of superheat of the refrigeration cycle system by controlling the opening and closing of the motor-operated valve according to the control program 71 based on at least temperature information.

[0021] The EEPROM (Electrically Erasable Programmable Read Only Memory) 7 is a readable and writable nonvolatile semiconductor memory, and functions as a storage unit in which a control program 71 for the control microcomputer 6 is stored. In the configuration of Fig. 2, the EEPROM 7 is external to the control microcomputer 6, but if the control microcomputer 6 has a built-in nonvolatile memory, the control program 71 may be stored in the nonvolatile memory.

[0022] The temperature sensor 11 collectively refers to the evaporator outlet temperature sensor 25, the evaporator inlet temperature sensor 26, and the inside temperature sensor 27 shown in Fig. 1. The pressure sensor 12 is a sensor that detects the evaporation pressure on the outlet side of the evaporator 21. The start input 13 receives an operation instruction for the controller 1 output from the upper system 14, and outputs it to the controller 1.

[0023] The host system 14 is a system that controls each device shown in Fig. 1, the refrigerator 22, etc. The host system 14 is composed of, for example, a computer. The host system 14 issues an operation instruction to the controller 1 via the start input 13.

[0024] The user PC 15 is, for example, a PC (personal computer) owned by a user, a maintenance worker, etc. The user PC 15 stores an update program (new control program) 151 for the control program 71 of the control microcomputer 6, and updates the control program 71 via the communication circuit 2 by connecting to the controller 1. The update program 151 is an updated version of the control program 71 as described above.

[0025] Next, an update operation of the control program 71 in the controller 1 having the above-mentioned configuration will be described with reference to the flowcharts of Fig. 3 and Fig. 4. Fig. 3 is a flowchart in the case where an operation instruction from the contact detection circuit 5 is not referred to. The flowcharts shown in Fig. 3 and Fig. 4 are executed by the control microcomputer 6. Therefore, the control microcomputer 6 functions as an update unit that updates the control program to a new control program.

[0026] First, the control microcomputer 6 determines whether the superheat degree control is being performed (step S101). That is, the control microcomputer 6 determines whether the opening degree of the electronic expansion valve 24 is being controlled at the present time.

[0027] If the result of the determination in step S101 is that the superheat degree control is being performed (step S101: Yes), the control microcomputer 6 determines whether there is a request to update the control program 71 (step S102). The update request is input from the user PC 15 via the communication circuit 2.

[0028] Next, if it is determined in step S102 that there is a request to update the control program 71 (step S102: Yes), the control microcomputer 6 stops the superheat degree control (step S103) and starts updating the control program 71 (step S104).

[0029] On the other hand, if it is determined in step S102 that there is no request to update the control program 71 (step S102: No), the control microcomputer 6 continues the superheat degree control (step S105) and controls the opening degree of the electronic expansion valve 24 (step S106). In other words, since there is no request to update, normal operation is continued.

[0030] On the other hand, if the result of the determination in step S101 is that the superheat degree control is not being performed (step S101: No), the control microcomputer 6 determines whether the control program 71 is being updated (step S107). That is, it determines whether the update program 151 acquired via the communication circuit 2 is being stored in the EEPROM 7.

[0031] As a result of the determination in step S107, if an update is in progress (step S107: Yes), the control microcomputer 6 continues the update as is (step S108). During this update, the electronic expansion valve 24 is fully closed (step S109). That is, the control microcomputer 6 stops the electronic expansion valve 24 so as to maintain it in a predetermined state. The predetermined state is preferably a safe state for the refrigeration cycle system, and in this embodiment, as an example, it is fully closed.

[0032] By fully closing the electronic expansion valve 24, a vacuum is created from the electronic expansion valve 24 to the compressor, eliminating the liquefied refrigerant and preventing it from accumulating in the piping. Therefore, liquid compression will not occur the next time the compressor is started, and damage to the compressor can be prevented. Note that the predetermined state is not limited to being fully closed as long as it can be maintained in a safe state, and may be fully open. Alternatively, it may be a slightly open state with a slight leak. In other words, the predetermined state may be set appropriately depending on the application, installation environment, etc.

[0033] As the predetermined state, an initial value may be set as described above and applied at all times, but the user may be able to change it as appropriate using, for example, the user PC 15. That is, the user PC 15 functions as a setting unit that sets the predetermined state, and the predetermined state can be changed to the state set by the user PC (setting unit).

[0034] 3, if the result of the determination in step S107 is that the update is not in progress (step S107: No), the control microcomputer 6 stops the update (step S110) and starts the superheat degree control (step S111). In other words, since the writing to the EEPROM 7 is completed and the update is finished, the superheat degree control is started by the updated control program 71.

[0035] Next, a case where an operation instruction is referred to from the contact detection circuit 5 will be described with reference to the flowchart of Fig. 4. First, the control microcomputer 6 determines whether superheat degree control is in progress (step S201). In step S201, similar to step S101, the control microcomputer 6 determines whether opening and closing control of the electronic expansion valve 24 is in progress.

[0036] If the result of the determination in step S201 is that superheat degree control is in progress (step S201: Yes), the control microcomputer 6 determines whether the start input is ON (step S202). That is, it determines whether the operation instruction input from the contact detection circuit 5 is start. If the result of the determination in step S202 is that the start input is ON (step S202: Yes), the control microcomputer 6 continues the superheat degree control (step S203) and controls the opening degree of the electronic expansion valve 24 (step S204). That is, since there is no request for an update, normal operation is continued.

[0037] On the other hand, if the result of the determination in step S202 is that the start input is not ON (step S202: No), the control microcomputer 6 stops the superheat degree control (step S205). In other words, since the operation instruction input from the contact detection circuit 5 is stopped (not ON), the superheat degree control is stopped.

[0038] On the other hand, if the result of the determination in step S201 is that superheat degree control is not in progress (step S201: No), the control microcomputer 6 determines whether the start input is ON (step S206). If the result of the determination in step S206 is that the start input is ON (step S206: Yes), the control microcomputer 6 determines whether the control program 71 is being updated (step S207). Step S206 is the same as step S202. Also, step S207 is the same as step S107 in FIG. 3.

[0039] As a result of the determination in step S207, if an update is in progress (step S207: Yes), the control microcomputer 6 continues the update as is (step S208). During this update, the electronic expansion valve 24 is fully closed (step S209). Steps S208 to S209 are the same as steps S108 to S109 in FIG. 3.

[0040] If it is determined in step S207 that updating is not in progress (step S207: No), the control microcomputer 6 starts superheat degree control (step S210). In step S210, the start input is ON and updating is not in progress, so superheat degree control is started according to the instruction of the start input.

[0041] On the other hand, if it is determined in step S206 that the start input is not ON (step S206: No), the control microcomputer 6 determines whether the control program 71 is being updated (step S211). If it is determined in step S211 that the control program 71 is being updated (step S211: Yes), the control microcomputer 6 continues the update (step S212). During this update, the electronic expansion valve 24 is fully closed (step S213). Steps S211 to S213 are similar to steps S207 to S209.

[0042] If the result of the determination in step S211 is that an update is not in progress (step S211: No), the control microcomputer 6 determines whether there is a request to update the control program 71 (step S214). If the result of the determination in step S214 is that there is a request to update the control program (step S214: Yes), the control microcomputer 6 starts updating the control program 71 (step S215). At this time, the electronic expansion valve 24 is also fully closed (step S216).

[0043] On the other hand, if it is determined in step S214 that there is no request to update the control program 71 (step S214: No), the control microcomputer 6 stops updating the control program 71 (step S217). That is, similar to step S110 in Fig. 3, writing to the EEPROM 7 is completed and the update ends. In the case of step S217, the start input is not ON (step S206: No), so superheat degree control does not start.

[0044] In the flowchart of Fig. 4, if step S206 is "No", the update is being performed. That is, the control microcomputer 6 determines whether the control program 71 can be updated based on the information regarding the operation instruction. Since the update is being performed when step S206 branches to "No", the control microcomputer 6 determines that the control program 71 can be updated if the information regarding the operation instruction is an instruction to stop normal operation.

[0045] Here, the states of steps S208 and S210 will be described. When starting an update, the following steps are executed: step S201: No, step S206: No, step S211: No, and step S214: Yes. Therefore, the start input is usually OFF during an update, but since the upper system 14 is not directly involved in the update operation, the start input may turn ON during an update. In that case, the update is prioritized over the start input, and the process proceeds to step S208 to continue the update. Then, when the update is completed, the process proceeds to step S210, and superheat control is started in response to the start input turning ON.

[0046] In other words, if the operation instruction switches from OFF (instruction indicating the stop of normal operation) to ON (instruction indicating startup) during an update, the control microcontroller 6 starts controlling the opening and closing of the electronic expansion valve 24 (motor-operated valve) after the update is completed.

[0047] According to this embodiment, the controller 1 includes a control microcomputer 6 that controls the opening and closing of the electronic expansion valve 24 by a control program 71 based on temperature data and pressure data, thereby controlling the degree of superheat of the refrigeration cycle system, and a communication circuit 2 that receives an update program 151 from the outside. While updating the control program 71 to the update program 151, the control microcomputer 6 holds the electronic expansion valve 24 in a fully closed state.

[0048] By configuring the controller 1 as described above, the electronic expansion valve 24 is kept fully closed, so that the control program 71 can be updated without affecting, for example, the compressor that constitutes the refrigeration cycle system when updating the control program 71 or when restarting the system after updating is completed.

[0049] In addition, the state of the electronic expansion valve 24 when updating the control program 71 may be preset as an initial value. In this way, the control program can be updated while maintaining a safe state for most refrigeration cycle systems.

[0050] Also, a predetermined state can be set from the user PC 15 via the communication circuit 2, and the state can be changed to a set state (fully closed, fully open, slight leakage, etc.) via the communication circuit 2. In this way, the setting can be changed to an appropriate state depending on the system.

[0051] Also, a contact detection circuit 5 to which an operation instruction is input from the upper system 14 is provided, and the control microcomputer 6 determines whether an update is possible based on the operation instruction. In this manner, when updating the control program 71 based on the operation instruction of the upper system 14, it is possible to know that there is no problem in the system and update it. For example, the control program 71 can be updated when the controller 1 is not expected to perform a control operation, such as when the controller 1 is not in a started state.

[0052] Furthermore, when the operation instruction is an instruction to stop normal operation, the control microcomputer 6 determines that it is possible to update the control program 71. Therefore, the control microcomputer 6 updates the control program 71 while determining that the superheat control, which is normal operation, has stopped and that there is no malfunction in the system.

[0053] Furthermore, when the operation instruction is switched from an instruction to stop normal operation to an instruction to start during the update of the control program 71, the control microcomputer 6 starts the opening and closing control of the electronic expansion valve 24 after the update of the control program 71 is completed. In this manner, even if the controller 1 is in the process of updating the control program 71 and is in an uncontrollable state, and is instructed to start (operate), the controller 1 can ignore the start instruction and go through with the update until the update is completed.

[0054] In the above embodiment, the update program 151 stored in the EEPROM 7 is simply updated. However, for example, as shown in FIG. 5, the storage area of ​​the EEPROM 7 may be provided with two areas, an area 7a and an area 7b. When the pre-update control program 71 is stored in the area 7a, the update program 151 may be stored in the area 7b, and when the next update is performed, the update program 151 may be stored in the area 7a. In other words, an area for storing the update program 151 and an area for storing the pre-update control program 71 may be provided. These areas may be updated alternately.

[0055] The control microcomputer 6 then determines whether the update of the control program 71 has been successful, and if the result of the determination is that the update has failed, the control microcomputer 6 may switch to the control program 71 before the update. In other words, the control program 71 may be read from an area in which the control program 71 before the update is stored. The failure of the update may be determined by using an error detection code such as a checksum.

[0056] By doing so, even if the update fails, it is possible to return to the previous control program 71. Therefore, it is possible to at least ensure the operation before the update.

[0057] Furthermore, when the operation instruction changes from an instruction to stop normal operation to an instruction to start during switching to the pre-update control program 71, the control microcomputer 6 may start the opening and closing control of the electronic expansion valve 24 after the switching is completed. In this manner, as in the case of updating the update program 151, even if a start (operation) instruction is received from the upper system 14 during switching to the pre-update control program 71, the start instruction can be ignored and the switching can be completed until the switching is completed.

[0058] 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]

[0059] 1 Controller (superheat controller) 2 Communication circuit (receiver) 5 Contact detection circuit (input section) 6 Control microcomputer (control unit, update unit) 7 EEPROM (storage section) 15 User PC (settings section) 24 Electronic expansion valve (motorized valve) 71 Control Program 151 Update program (new control program)

Claims

1. a control unit that controls the degree of superheat of the refrigeration cycle system by controlling opening and closing of the motor-operated valve based on at least temperature information by a control program; a receiving unit that receives a new control program from an external device; an update unit that updates the control program to the new control program; Equipped with The control unit maintains the motor-operated valve in a predetermined state while the update unit is performing the update. An electric valve control device comprising:

2. 2. The motor-operated valve control device according to claim 1, wherein the predetermined state is determined in advance as an initial value.

3. A setting unit that sets the predetermined state, The predetermined state can be changed to a state set by the setting unit.

2. The motor-operated valve control device according to claim 1.

4. An input unit for inputting information regarding an operation instruction from a higher-level device, The update unit determines whether the update is possible based on information related to the operation instruction.

2. The motor-operated valve control device according to claim 1.

5. 5. The motor-operated valve control device according to claim 4, wherein the update unit determines that the update is possible when the information on the operation instruction is an instruction to stop a normal operation.

6. The electric valve control device according to claim 5, characterized in that, when the information regarding the operation instruction changes from an instruction indicating the stop of the normal operation to an instruction indicating the start of the normal operation during the update, the update unit causes the control unit to start opening and closing control of the electric valve after the update is completed.

7. A storage unit for storing the control program is further provided.

5. The motor-operated valve control device according to claim 4, wherein the storage unit is provided with an area for storing the new control program and an area for storing the control program before the update.

8. The electrically operated valve control device according to claim 7, wherein the update unit determines whether the update has been successful, and if the update has failed, the update unit switches to the control program before the update.

9. The electric valve control device according to claim 8, characterized in that if the information regarding the operation instructions changes from an instruction indicating the stop of normal operation to an instruction indicating the start of operation during switching to the control program before the update, the update unit causes the control unit to start controlling the opening and closing of the electric valve after the switching is completed.

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