Electric valve control device

Abstract

The invention provides an electric valve control device, and aims to easily update a control program. The controller (1) is provided with: a control microcomputer (6) for controlling the degree of superheat of the refrigeration cycle system by controlling the opening and closing of the electronic expansion valve (24) by means of a control program (71) on the basis of temperature data and pressure data; and a communication circuit (2) that receives the update program (151) from the outside. Furthermore, when the control microcomputer (6) updates the control program (71) to the update program (151), the electronic expansion valve (24) is kept in a fully closed state.

Description

Technical Field

[0001] The present invention relates to a control device for electric valves such as a superheat controller and an electronic expansion valve. Background Art

[0002] Conventionally, there is known a refrigeration device using an electronic expansion valve. This refrigeration device obtains the difference (superheat) between the temperature at the outlet side of an evaporator and the temperature at the inlet side of the evaporator of a refrigeration cycle system of the refrigeration device, and controls the opening of the electronic expansion valve, for example, by PID control, based on the deviation between the measured value of the superheat and the set value (target value) of the superheat (for example, see Patent Document 1).

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent No. 4672001 Summary of the invention

[0006] Problems to be solved by the invention

[0007] The control of the electric valves such as the electronic expansion valves described above is often performed by a control program executed by a microcomputer etc. Such a control program is sometimes updated by adding functions, correcting malfunctions, etc.

[0008] However, updating of the control program in such an electric valve control device is performed by manually estimating the timing of system stoppage, etc., which takes time and effort.

[0009] In order to save such trouble, it is also considered to automatically update the control program, but depending on the state of the electric valve when it stops, it may affect other equipment such as the compressor that constitutes the refrigeration cycle system. Therefore, sometimes it is not enough to automatically update it only when the system stops.

[0010] Therefore, an object of the present invention is to enable easy updating of a control program without affecting other equipment and the like constituting a refrigeration cycle system.

[0011] Solutions to Solve Problems

[0012] The invention completed to solve the above-mentioned problems is characterized in that it comprises: a control unit, which controls the opening and closing of the electric valve at least based on temperature information and through a control program, thereby controlling the superheat of the refrigeration cycle system; a receiving unit, which receives a new control program from the outside; and an updating unit, which updates the control program to the new control program, and the control unit maintains the electric valve in a predetermined state when the updating unit performs the updating.

[0013] Effects of the Invention

[0014] According to the present invention, by holding the electric valve in a predetermined state, the control program can be updated without affecting other devices constituting the refrigeration cycle system, for example, when updating the control program or restarting after completion. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is a diagram showing an example of a refrigeration system using an electronic expansion valve as an electric valve according to an embodiment of the present invention.

[0016] Figure 2 So Figure 1 The schematic structure of the system centered on the controller is shown.

[0017] Figure 3 yes Figure 2 Flowchart of the update action of the controller shown.

[0018] Figure 4 yes Figure 2 Flowchart of the update action of the controller shown.

[0019] Figure 5 Yes means Figure 2 FIG. 2 is a diagram showing a modified example of the method of using the EEPROM shown.

[0020] In the figure:

[0021] 1—controller (superheat controller); 2—communication circuit (receiving part); 5—contact detection circuit (input part); 6—control microcomputer (control part, update part); 7—EEPROM (storage part); 15—user PC (setting part); 24—electronic expansion valve (electric valve); 71—control program; 151—update program (new control program). DETAILED DESCRIPTION

[0022] A superheat controller and an electric valve control circuit according to an embodiment of the present invention will be described. Figure 1 This is a diagram showing an example of a refrigeration system using an electronic expansion valve as the electric valve according to the present embodiment.

[0023] like Figure 1 As shown, the cooling device forms a known refrigeration cycle by connecting an evaporator 21 provided in a freezer 20, a compressor and a condenser in a refrigerator 22, a liquid supply electromagnetic valve 23, and an electronic expansion valve 24 in a ring shape through piping.

[0024] Figure 1Symbol 25 is an evaporator outlet temperature sensor for measuring the temperature on the outlet side of the evaporator 21, symbol 26 is an evaporator inlet temperature sensor for measuring the temperature on the inlet side of the evaporator 21, symbol 27 is an internal temperature sensor for measuring the temperature inside the freezer 20, and the measurement signals of these sensors are input to the controller 1.

[0025] The controller 1 includes a control unit such as a microcomputer (microcomputer), a drive circuit for an electronic expansion valve, a memory, a display unit, and an operation unit, etc. It obtains the difference (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 for controlling the opening of the electronic expansion valve 24 by PID control according to the deviation between the measured value of the superheat and the set value (target value) of the superheat. In addition, the controller 1 is also called a superheat controller.

[0026] Figure 2 express Figure 1 The schematic structure diagram of the controller 1 is shown in FIG. Figure 1 As shown, the controller 1 includes a communication circuit 2, a measurement circuit 3, a drive circuit 4, a contact point detection circuit 5, a control microcomputer 6 and an EEPROM 7.

[0027] The communication circuit 2 communicates with the user PC 15 described later by serial communication, for example. Then, the communication circuit 2 receives the 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 a new control program from the outside.

[0028] 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.

[0029] 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. For example, the drive circuit 4 can be configured as a constant current chopper drive circuit.

[0030] The contact detection circuit 5 receives an action instruction from a start input 13 described later. That is, the contact detection circuit 5 functions as an input unit for inputting information related to the action instruction from the host device. The contact detection circuit 5 outputs the input action instruction to the control microcomputer 6. The action instruction includes, for example, start or stop. When the action instruction is "ON", it indicates start, and when the action instruction is "OFF", it indicates stop.

[0031] The control microcomputer 6 is responsible for the overall control of the controller 1. Based on the temperature data and pressure data input from the measurement circuit 3, the control microcomputer 6 generates an excitation signal for controlling the opening of the electronic expansion valve 24 and outputs it to the drive circuit 4. In addition, the control microcomputer 6 performs the above-mentioned overall control, the drive of the electronic expansion valve 24, etc. through the control program 71 stored in the EEPROM 7. That is, the control microcomputer 6 functions as a control unit, which controls the opening and closing of the electric valve based on at least the temperature information and through the control program 71, thereby controlling the superheat of the refrigeration cycle system.

[0032] The EEPROM (Electrically Erasable Programmable Read Only Memory) 7 is a readable and writable non-volatile semiconductor memory, and functions as a storage unit storing a control program 71 for the control microcomputer 6. Figure 2 In the structure, the EEPROM 7 is an external component of the control microcomputer 6. However, when a nonvolatile memory is built into the control microcomputer 6, the control program 71 can also be stored in the nonvolatile memory.

[0033] The temperature sensor 11 is Figure 1 The evaporator outlet temperature sensor 25, the evaporator inlet temperature sensor 26, and the internal temperature sensor 27 are collectively referred to as shown. The pressure sensor 12 is a sensor for detecting 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 host system 14 and outputs it to the controller 1.

[0034] The host system 14 is a control Figure 1 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.

[0035] 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 of the control program 71 of the control microcomputer 6, and is connected to the controller 1 to update the control program 71 via the communication circuit 2. In addition, the update program 151 is an updated version of the control program 71 as described above.

[0036] Next, refer to Figure 3 as well as Figure 4 The flowchart of will now explain the updating operation of the control program 71 in the controller 1 having the above-described configuration. Figure 3 This is a flowchart when the operation instruction from the contact point detection circuit 5 is not referred to. Figure 3 as well as Figure 4The flowchart shown is 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.

[0037] First, the control microcomputer 6 determines whether or not superheat control is being performed (step S101 ). That is, the control microcomputer 6 determines whether or not the opening degree of the electronic expansion valve 24 is being controlled at the current time point.

[0038] If the result of determination in step S101 is that superheat control is in progress (step S101 : YES), the control microcomputer 6 determines whether there is an update request for the control program 71 (step S102 ). The update request is input from the user PC 15 via the communication circuit 2 .

[0039] Next, when the result of determination in step S102 is that there is a request to update the control program 71 (step S102 : Yes), the control microcomputer 6 stops the superheat control (step S103 ) and starts updating the control program 71 (step S104 ).

[0040] On the other hand, if the result of determination in step S102 is that there is no update request for the control program 71 (step S102: No), the control microcomputer 6 continues superheat control (step S105) and controls the opening of the electronic expansion valve 24 (step S106). That is, since there is no update request, normal operation is continued.

[0041] On the other hand, if the result of step S101 is that superheat control is not in progress (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 stored in the EEPROM 7.

[0042] When the result of determination in step S107 is that the update is in progress (step S107: Yes), the control microcomputer 6 directly continues the update (step S108). In addition, during the update, the opening of the electronic expansion valve 24 is set to be fully closed (step S109). That is, the control microcomputer 6 stops the electronic expansion valve 24 to maintain it in a predetermined state. As the predetermined state, it is preferable that the refrigeration cycle system is in a safe state, and in the present embodiment, it is set to be fully closed as an example.

[0043] By fully closing the electronic expansion valve 24, a vacuum state can be set from the electronic expansion valve 24 to the compressor to eliminate the liquefied refrigerant, so that it does not accumulate in the piping. Therefore, liquid compression will not occur at the next startup, and damage to the compressor can be prevented. In addition, as a predetermined state, as long as it can be maintained in a safe state, it is not limited to fully closed, and it can also be fully open. Alternatively, it can also be a slightly opened slightly open state. That is, the predetermined state can be appropriately set according to the purpose, installation environment, etc.

[0044] In addition, as the predetermined state, an initial value may be set as described above and always applied, but the user may be able to change it appropriately using the user PC 15, etc. That is, the user PC 15 functions as a setting unit for setting the predetermined state, and the predetermined state can be changed to the state set by the user PC (setting unit).

[0045] return Figure 3 As explained above, if the result of determination in step S107 is that the program is not being updated (step S107: No), the control microcomputer 6 stops updating (step S110) and starts superheat control (step S111). That is, writing to the EEPROM 7 is completed, and the updating is completed, so superheat control is started by the updated control program 71.

[0046] Next, refer to Figure 4 The flowchart of FIG. 1 illustrates the case where the contact detection circuit 5 refers to the operation instruction. First, the control microcomputer 6 determines whether the superheat control is in progress (step S201). Step S201 is similar to step S101, and the control microcomputer 6 determines whether the electronic expansion valve 24 is under opening and closing control.

[0047] If the result of determination in step S201 is that the superheat 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 a start. If the result of determination in step S202 is that the start input is ON (step S202: Yes), the control microcomputer 6 continues the superheat control (step S203) and controls the opening of the electronic expansion valve 24 (step S204). That is, since there is no request for update, the normal operation is continued.

[0048] On the other hand, if the start input is not ON in step S202 (step S202: No), the control microcomputer 6 stops the superheat control (step S205). That is, since the operation instruction input from the contact detection circuit 5 is stop (not ON), the superheat control is stopped.

[0049] On the other hand, if the result of the determination in step S201 is that the superheat control is not in progress (step S201: No), the control microcomputer 6 determines whether the start input is ON (step S206). As a result of the determination in step S206, if 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. In addition, step S207 is the same as step S208. Figure 3 The same as step S107.

[0050] If the result of step S207 is that the update is in progress (step S207: Yes), the control microcomputer 6 continues the update as it is (step S208). In addition, during the update, the opening of the electronic expansion valve 24 is set to fully closed (step S209). Steps S208 to S209 are similar to Figure 3 Steps S108 to S109 are the same.

[0051] If the result of step S207 is that the system is not being updated (step S207: No), the control microcomputer 6 starts superheat control (step S210). In step S210, the start input is ON and the system is not being updated, so the superheat control starts according to the instruction of the start input.

[0052] On the other hand, as a result of the determination in step S206, when the start input is not ON (step S206: No), the control microcomputer 6 determines whether the control program 71 is being updated (step S211). When the determination result in step S211 is that the control program 71 is being updated (step S211: Yes), the control microcomputer 6 directly continues the update (step S212). In addition, during the update, the opening of the electronic expansion valve 24 is set to fully closed (step S213). Steps S211 to S213 are the same as steps S207 to S209.

[0053] If the result of the determination in step S211 is that the control program 71 is not being updated (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 opening of the electronic expansion valve 24 is also set to fully closed (step S216).

[0054] On the other hand, if the result of the determination in step S214 is that there is no update request for the control program 71 (step S214: No), the control microcomputer 6 stops the update of the control program 71 (step S217). Figure 3Similarly to step S110, writing to EEPROM 7 is completed and the updating is completed. In the case of step S217, the start input is not ON (step S206: No), so the superheat control is not started.

[0055] exist Figure 4 In the flowchart of FIG. 1 , when step S206 is “No”, the update is performed. That is, the control microcomputer 6 determines whether the control program 71 can be updated based on the information related to the operation instruction. Then, the update is performed when step S206 branches to “No”, so the control microcomputer 6 determines that the control program 71 can be updated when the information related to the operation instruction is an instruction to stop the normal operation.

[0056] Here, the states of steps S208 and S210 are explained. When starting the update, if step S201: No, step S206: No, step S211: No, and step S214: Yes, then it is executed. Therefore, the start input is usually OFF during the update, but since the upper system 14 does not directly participate in the update action, there may be a case where the start input is ON during the update. In this case, the update is prioritized over the start input and the update is continued in step S208. Then, when the update is completed, step S210 is entered, and superheat control is started corresponding to the start input ON.

[0057] That is, when the operation instruction is switched from OFF (instruction indicating stop of normal operation) to ON (instruction indicating start) during update, the control microcomputer 6 starts opening and closing control of the electronic expansion valve 24 (electric valve) after the update is completed.

[0058] According to the present embodiment, the controller 1 includes: a control microcomputer 6 that controls the opening and closing of the electronic expansion valve 24 through a control program 71 based on temperature data and pressure data, thereby controlling the superheat of the refrigeration cycle system; and a communication circuit 2 that receives an update program 151 from the outside. Furthermore, when the control microcomputer 6 updates the control program 71 to the update program 151, the electronic expansion valve 24 is kept in a fully closed state.

[0059] By configuring the controller 1 as described above, the electronic expansion valve 24 is kept in the fully closed state, so that when the control program 71 is updated or restarted after the update is completed, the update can be performed without affecting, for example, the compressor constituting the refrigeration cycle.

[0060] In addition, the holding state of the electronic expansion valve 24 may be predetermined as an initial value when the control program 71 is updated. Thus, the control program can be updated while keeping most of the refrigeration cycle systems in a safe state.

[0061] In addition, a predetermined state may be set from the user PC 15 via the communication circuit 2, and the state (fully closed, fully open, slightly open, etc.) set via the communication circuit 2 may be changed. Thus, the setting may be changed to an appropriate state according to the system.

[0062] In addition, the contact detection circuit 5 is provided to input an action instruction from the host system 14, and the control microcomputer 6 determines whether the update is possible based on the action instruction. Therefore, when the control program 71 is updated based on the action instruction of the host system 14, it is possible to understand that there is no malfunction 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 action, such as when it is not in the startup state.

[0063] When the operation instruction indicates stopping the normal operation, the control microcomputer 6 determines that it is possible to update the control program 71. Therefore, it is understood that the superheat control as the normal operation is stopped and there is no malfunction in the system, and the control program 71 is updated.

[0064] In addition, when the action instruction of the control microcomputer 6 is switched from the instruction indicating the stop of the normal action to the instruction indicating the start during the update of the control program 71, the opening and closing control of the electronic expansion valve 24 is started after the update of the control program 71 is completed. In this way, the controller 1 is in an uncontrollable state during the update of the control program 71. In this way, even if the start (action) is instructed from the upper system 14, the start instruction can be ignored before the update is completed and the update can be completed.

[0065] In the above-mentioned embodiment, the case where only the update program 151 stored in the EEPROM 7 is updated is described, but for example Figure 5 As shown in FIG. 1 , two areas, area 7a and area 7b, may be provided in the storage area of ​​EEPROM 7. Furthermore, when the control program 71 before update is stored in area 7a, the update program 151 may be stored in area 7b, and when the update is performed next, the update program 151 may be stored in area 7a. That is, an area for storing the update program 151 and an area for storing the control program 71 before update may be provided. Furthermore, these areas may be updated alternately.

[0066] Furthermore, the control microcomputer 6 may determine whether the update of the control program 71 is successful, and if the result of the determination is that the update has failed, switch to the control program 71 before the update. That is, the control program 71 may be read from the area storing the control program 71 before the update. The failure of the update may be determined by using, for example, an error detection code such as a checksum.

[0067] Thus, even when the update fails, it is possible to return to the previous control program 71. Therefore, at least the operation before the update can be ensured.

[0068] In addition, when the action instruction is switched from the instruction indicating the stop of the normal action to the instruction indicating the start during the switching to the control program 71 before the update, the control microcomputer 6 can also start the opening and closing control of the electronic expansion valve 24 after the switching is completed. Thus, in the same way as when the update program 151 is updated, during the switching to the control program 71 before the update, even if the start (action) is instructed from the upper system 14, the start instruction can be ignored before the switching is completed and the switching can be completed.

[0069] In addition, the present invention is not limited to the above-mentioned embodiments. That is, those skilled in the art can implement the present invention by various modifications according to the previously known understandings without departing from the scope of the present invention. Through such modifications, as long as the structure of the electric valve control device of the present invention is provided, it is of course also included in the scope of the present invention.

Claims

1. An electric valve control device, characterized in that: have: a control unit that controls the opening and closing of the electric valve by a control program based at least on the temperature information, thereby controlling the superheat of the refrigeration cycle system; 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, The control unit maintains the electric valve in a predetermined state when the updating unit performs the updating.

2. The electric valve control device according to claim 1, characterized in that: The predetermined state is predetermined as an initial value.

3. The electric valve control device according to claim 1, characterized in that: A setting unit is provided, the setting unit setting the predetermined state, The predetermined state can be changed to a state set by the setting unit.

4. The electric valve control device according to claim 1, characterized in that: The device further comprises an input unit for inputting information related to the action instruction from a host device. The updating unit determines whether the updating is possible based on the information related to the operation instruction.

5. The electric valve control device according to claim 4, characterized in that: The updating unit determines that the updating is possible when the information related to the operation instruction is an instruction to stop the normal operation.

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

7. The electric valve control device according to claim 4, characterized in that: further comprising a storage unit storing the control program, The storage unit is provided with an area for storing the new control program and an area for storing the control program before updating.

8. The electric valve control device according to claim 7, characterized in that: The updating unit determines whether the updating is successful, and switches to the control program before the updating if the updating fails.

9. The electric valve control device according to claim 8, characterized in that: When the information related to the operation instruction is switched from an instruction indicating stopping the normal operation to an instruction indicating starting during the switching to the control program before the update, the update unit causes the control unit to start opening and closing control of the electric valve after the switching is completed.

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