Electric valve and temperature adjustment system

Abstract

This electric valve 30 comprises: a valve body 40 having a valve chamber 42 and a valve port 44 connected to the valve chamber 42; a valve body 46 which moves with respect to the valve port 44; a drive device 50 for driving the valve body 46; a temperature sensor 90 for acquiring the temperature of a refrigerant; and a control unit 70 for controlling the drive device 50. A control procedure of the control unit 70 has: a manual mode for controlling the drive device 50 on the basis of a control command of a control device 22 for determining a control amount of the drive device 50; and an autonomous mode for controlling the drive device 50 by determining the control amount of the drive device 50 on the basis of the temperature of the refrigerant acquired by the temperature sensor 90.

Description

Electric valve and temperature control system

[0001] The present disclosure relates to an electric valve and a temperature control system.

[0002] For example, as disclosed in International Publication No. 2022 / 168651, an electric valve having a stator unit with an inner space where a magnet is disposed is known. The electric valve of International Publication No. 2022 / ABCDEFG has a stator unit having a substrate that drives and controls a stepping motor.

[0003] The present disclosure provides an electric valve that performs control based on a control index even when there is no control command from a control device to control a driving device.

[0004] The electric valve according to the first aspect is an electric valve including a valve body having a valve chamber and a valve port connected to the valve chamber, a valve element that moves with respect to the valve port, a driving device that drives the valve element, an acquisition unit that acquires a control index, and a control unit that controls the driving device. As a control method of the control unit, there are a heteronomous mode in which the driving device is controlled based on a control command of a control device that determines a control amount of the driving device, and an autonomous mode in which a control amount of the driving device is determined based on the control index acquired by the acquisition unit and the driving device is controlled.

[0005] The electric valve according to this aspect has, as a control method of the control unit, a heteronomous mode in which the driving device is controlled based on a control command of a control device that determines a control amount of the driving device, and an autonomous mode in which a control amount of the driving device is determined based on the control index acquired by the acquisition unit and the driving device is controlled. Therefore, according to the electric valve according to this aspect, control based on the control index can be performed even when there is no control command from the control device to control the driving device.

[0006] The electric valve according to the second aspect is the electric valve according to the first aspect, wherein when the control unit controls in the autonomous mode, the control unit makes the control index approach a target value notified from the control device.

[0007] In this embodiment of the electric valve, when the control unit controls in autonomous mode, it brings the control index closer to the target value notified by the control device. Therefore, with this embodiment of the electric valve, control is more stable even without notification of a control command from the control device, compared to when the target value is determined by the electric valve itself.

[0008] In the third embodiment of the electric valve, the control unit notifies the control device when the control index does not fall within the target range based on the target value.

[0009] In this embodiment of the electric valve, the control unit notifies the control device if the control index does not fall within the target range based on the target value. Therefore, with this embodiment of the electric valve, if the control index cannot be brought within the target range by the operation of the electric valve alone, the control device can be notified of the control index.

[0010] The electric valve of the fourth embodiment is the electric valve of the third embodiment, wherein the control unit controls in the heteronomous mode when the control index does not fall within the target range based on the target value.

[0011] In this embodiment, the electric valve controls the control unit in a heteronomous mode when the control index does not fall within the target range based on the target value. Therefore, with this embodiment, if the electric valve alone cannot bring the control index within the target range, it can receive a control command from the control device and control the control index.

[0012] The fifth embodiment of the electric valve is an electric valve described in any one of the first to fourth embodiments, wherein the acquisition unit is a measurement unit that measures a control index.

[0013] In this embodiment of the electric valve, the acquisition unit is a measuring unit that measures a control index. Therefore, with this embodiment of the electric valve, the control index can be acquired without the use of external equipment.

[0014] The sixth embodiment of the temperature control system comprises a pump for circulating a fluid that transfers thermal energy from a heat absorber to a heat radiator, an electric valve according to any one of the first to fifth embodiments for controlling the flow of the fluid, and a control device that transmits control commands to the control unit of the electric valve upon user operation.

[0015] The temperature control system according to this embodiment includes a pump that circulates a fluid that transfers thermal energy from a heat absorber to a heat radiator, and an electric valve that controls the fluid flow. Furthermore, the temperature control system according to this embodiment includes a control device that transmits control commands to the control unit of the electric valve in response to user operation. As a result, the control cost of the control device is reduced in a temperature control system incorporating the electric valve according to this embodiment, and therefore the development cost of the control device and the capabilities required of the control device are reduced.

[0016] According to this disclosure, an electric valve is provided that performs control based on control indicators even when there is no control command from the control device to control the drive device.

[0017] This is a diagram of a chiller unit having a cooling system according to one embodiment of the present disclosure. This is a diagram illustrating an electric valve according to this embodiment. This is a block diagram illustrating the configuration of the electric valve of this embodiment. This is a diagram illustrating the procedure in which the control device of this embodiment operates. This is a diagram illustrating the procedure in which the control unit of the electric valve of this embodiment operates.

[0018] This embodiment is described below. In the following drawings, identical and similar parts are denoted by the same or similar reference numerals. However, the drawings are schematic, and the relationship between thickness and planar dimensions, the ratio of thickness of each device and component, etc., may differ from reality. Therefore, specific thicknesses and dimensions should be determined by referring to the following explanation. Furthermore, there are parts where the relationships and ratios of dimensions differ between drawings.

[0019] (Configuration) Figure 1 shows a chiller unit 10 having a cooling system 12 according to this embodiment. The chiller unit 10 has a cooling system 12 and a cooling water circuit 14.

[0020] The cooling system 12 is an example of a "temperature control system" in this embodiment. As shown in Figure 1, the cooling system 12 comprises a control device 22, an electric valve 30, an evaporator 18, a compressor 26, and a condenser 16. The electric valve 30, evaporator 18, compressor 26, and condenser 16 are connected to each other through a refrigerant pipe 20. The refrigerant pipe 20 contains a refrigerant, which is an example of a fluid in this embodiment.

[0021] The compressor 26 is an example of a "pump" in this embodiment and is a device that compresses gaseous refrigerant. The refrigerant compressed by the compressor 26 flows into the condenser 16, which is an example of a "heat exchanger" in this embodiment, and is liquefied while being cooled by the fan 24. The liquefied refrigerant flows into the electric valve 30.

[0022] The flow of the liquefied refrigerant is controlled by the electric valve 30. More specifically, the refrigerant is discharged with its pressure or flow rate adjusted by the electric valve 30, as will be described later. The specific configuration of the electric valve 30 will be described later.

[0023] The refrigerant that flows out from the electric valve 30 flows into the evaporator 18, which is an example of a "heat absorber" in this embodiment, and evaporates by absorbing thermal energy from the cooling water flowing through the cooling water circuit 14, as will be described later. The refrigerant that has absorbed thermal energy flows back into the compressor 26 and is compressed, thereby obtaining the refrigeration cycle of the cooling system 12 of the chiller unit 10 according to this embodiment.

[0024] As shown in Figure 1, the cooling water circuit 14 includes cooling water piping, a liquid pump 28 that circulates cooling water inside the cooling water piping, and a water tank WT.

[0025] The cooling water piping is a pipe through which cooling water flows to cool an object to be cooled (not shown) located outside the chiller unit 10. As shown in Figure 1, the cooling water piping is connected to an outlet from which cooling water flows out of the chiller unit 10 and an inlet from which cooling water flows into the chiller unit 10. The cooling water piping also connects to the evaporator 18, the water tank WT, and the pump.

[0026] The cooling water, whose temperature has risen due to the cooling of the object to be cooled, flows through the cooling water piping into the evaporator 18 of the cooling system 12. The cooling water that flows into the evaporator 18 is cooled as described above, flows out, and is stored in the water tank WT. The cooling water then flows out of the water tank WT again to the outside of the chiller unit 10 by the liquid transfer pump 28.

[0027] Next, the electric valve 30 and control device 22 in this embodiment will be described with reference to Figures 2 and 3. Figure 2 shows the electric valve 30 in this embodiment, and Figure 3 shows the electric valve 30 and control device 22 in this embodiment.

[0028] (Configuration of the electric valve 30) As shown in Figure 2, the electric valve 30 according to this embodiment comprises a valve body 40, a can 36, a valve element 46, a drive device 50, and a control unit 70. The drive device 50 comprises a rotor 52, a stator 56, and a valve element lifting drive mechanism 54.

[0029] (Valve body 40) The valve body 40 is a bottomed cylindrical member with an open top. The valve body 40 has a valve chamber 42 and a valve port 44. A valve seat 48 is formed on the upper side of the valve port 44, which the valve body 46 contacts as will be described later. The drive device 50 is inserted into the valve chamber 42 from the top of the valve body 40 as will be described later.

[0030] A first inlet / outlet 32, consisting of a pipe fitting, is connected to the left side of the valve chamber 42 of the valve body 40 in the diagram. Similarly, a second inlet / outlet 34, consisting of a pipe fitting, is connected to the lower side of the valve chamber 42 of the valve body 40 in the diagram.

[0031] (Can 36) The can 36 is a bottomed cylindrical member. The opening side of the can 36 faces downward in the figure and is joined to the valve body 40, thereby sealing the upper surface of the valve body 40. Inside the can 36, there is a disc body fixed by fitting into the inner wall surface of the can 36, and a shaft body 52S that is joined at one end to the disc body and extends in the vertical direction in the figure.

[0032] (Rotor 52) The rotor 52 has a cylindrical magnet and is rotatably positioned inside the can 36 by a shaft 52S, thereby allowing it to rotate on the upper side of the diagram relative to the valve chamber 42. The lower part of the rotor 52 is connected to the valve body lifting drive mechanism 54.

[0033] (Valve body lifting drive mechanism 54) The valve body lifting drive mechanism 54 is a mechanism for raising and lowering the valve body 46. More specifically, the valve body lifting drive mechanism 54 has a lead screw mechanism 54F, which converts the rotation of the rotor 52 into an up-and-down direction in the diagram. The lower part of the lead screw mechanism 54F is located inside the valve chamber 42. The lower part of the lead screw mechanism 54F is also positioned in contact with the valve body 46. When the rotor 52 rotates, the valve body 46 is driven in the up-and-down direction in the diagram by the valve body lifting drive mechanism 54.

[0034] (Valve body 46) As shown in the figure, the valve body 46 is a component located inside the valve chamber 42 and moves relative to the valve opening 44 by the operation of the valve body lifting drive mechanism 54 described above. The valve body 46 also closes the valve opening 44 by contacting the valve seat 48 at the valve opening 44, as shown in the figure. When the valve body 46 moves away from the valve opening 44, the refrigerant flows through the valve opening 44. The flow of the refrigerant is regulated by the distance between the valve body 46 and the valve opening 44.

[0035] (Stator 56) The stator 56 is positioned on the outer circumference of the can 36, that is, outside the can 36. The stator 56 includes a yoke, bobbin, coil 58, resin mold, etc. A pulse current is supplied to the coil 58 of the stator 56 from the control unit 70. The stator 56 and the rotor 52 constitute a stepping motor. In other words, the stator 56 drives the valve body 46 by rotating the rotor 52.

[0036] (Control Unit 70) As shown in Figure 3, the control unit 70 includes a regulator 74, a communication unit 76, a microcontroller 80, an angle sensor 78, a motor driver 72, and a temperature sensor 90.

[0037] As shown in Figure 3, the regulator 74 is connected to the power supply Vcc and ground Gnd, and is a component that provides the power supply Vdd to operate the control unit 70.

[0038] The communication unit 76 is a component for communicating with other devices such as the control device 22. Specifically, the communication unit 76 communicates with other devices using communication means such as wired, wireless, internet, intranet, and public lines such as telephone lines. The communication means may also be communication means using voice, light, vibration, images, etc.

[0039] The microcontroller 80 is a device that controls each part of the control unit 70. This microcontroller 80 has the functions of a computer and, as shown in Figure 3, has a CPU 81 (Central Processing Unit), RAM 82 (Random Access Memory), flash memory 83, AD converter 84, I / O interface 85, and RTC 86 (Real-Time Clock). The CPU 81, RAM 82, flash memory 83, AD converter 84, I / O interface 85, and RTC 86 are each interconnected by a control bus (not shown).

[0040] The CPU 81 is a central processing unit that executes various programs stored in the flash memory 83 and controls various parts. The RAM 82 temporarily stores programs or data as a working area. The AD converter 84 communicates with the motor driver 72 and converts the analog signal received from the angle sensor 78 into a digital signal and stores it in the RAM 82. The RTC 86 is a component that continuously measures the time and transmits a time signal to the CPU 81 indicating the time when the signal was transmitted.

[0041] The flash memory 83 stores various programs and data. More specifically, the flash memory 83 stores programs that are referenced in the control procedure described later. The flash memory 83 also records the measured values ​​of each measurement taken during the control procedure described later.

[0042] The angle sensor 78 is a so-called Hall sensor, which detects the rotation amount (rotation angle including the rotation direction) of the rotor 52. The detected rotation amount of the rotor 52 is stored as data in the RAM 82 by the AD converter 84 of the microcomputer 80 as described above.

[0043] The motor driver 72 is electrically connected to the microcomputer 80 and the stator 56, and is a component configured to convert the control signal of the stator 56 received from the microcomputer 80 into a pulse signal and transmit it to the stator 56. Also, for the pulse signal supplied to the stator 56, parameters such as voltage and current can be measured by the microcomputer 80. More specifically, in addition to the back electromotive voltage generated when a pulse current flows through the stator 56, it is possible to measure the current value corresponding to the rotational torque of the rotor 52, which corresponds to the mechanical resistance when driving the valve body 46.

[0044] The temperature sensor 90 is a sensor that measures the temperature of the refrigerant circulating inside the refrigerant pipe 20. More specifically, as an example, the temperature sensor 90 measures the temperature of the refrigerant flowing inside the refrigerant pipe of the downstream of the electric valve 30 and upstream of the evaporator 18. Then, the measured temperature of the refrigerant is transmitted to the microcomputer 80 as an electric signal. Also, the temperature of the refrigerant is stored as data in the RAM 82.

[0045] And the temperature sensor 90 corresponds to the "measurement unit" in the present embodiment. Also, the refrigerant is the control target of the electric valve 30 in the present embodiment. The temperature sensor's 90 measurement of the temperature and pressure of the refrigerant is an example of "acquiring control indicators" in the present embodiment. In other words, the temperature sensor 90 is also an example of the "detection unit" in the present embodiment.

[0046] Note that in the present embodiment, the specific configuration of the control unit 70 is of course not limited to the above. That is, each of the above-described configurations may be provided as so-called hardware, or may be provided as software that functions when the microcomputer 80 executes a program.

[0047] In addition, in the present embodiment, as shown in FIG. 2, the control unit 70 is arranged adjacent to the stator 56.

[0048] (Control device 22) The control device 22 is an external control device for the motorized valve 30, and is a device having an input unit 22I that receives a user's operation, an indication unit 22O that presents the state of the chiller unit 10 to the user, and a control unit 23. Further, the control device 22 is a device that transmits a control command to the motorized valve 30 according to the user's operation input to the input unit 22I. The input unit 22I and the indication unit 22O may have any configuration, but for example, a touch panel is used to serve the roles of both configurations.

[0049] The control unit 23 has a recording device (not shown) that stores various programs and various data. More specifically, the recording device stores the programs referred to in the control procedure described later. Also, the recording device records the past measured values measured in the control procedure described later as well.

[0050] Further, the control unit 23 of the control device 22 transmits a control command to the motorized valve 30 based on the temperature of the cooling water flowing through the cooling water circuit 14 measured by a sensor (not shown) so that the temperature of the cooling water becomes the set value input by the user's operation.

[0051] For example, when the temperature of the cooling water flowing through the cooling water circuit 14 is higher than the set value, the control device 22 transmits a control command to the control unit 70 in order to increase the cooling capacity of the evaporator 18. The control device 22 includes, as the control command, the distance (coordinate value) with respect to the valve port 44 of the motorized valve 30 in order to increase the opening degree (distance between the valve port 44 and the valve body 46) of the motorized valve 30. Further, based on the received control command, the control unit 70 transmits a pulse signal to the stator 56 to drive the valve body 46 so that the position of the valve body 46 is as per the coordinate value.

[0052] Furthermore, the control unit 23 of the control device 22 is capable of obtaining the refrigerant temperature from the control unit 70 of the electric valve 30. More specifically, the control unit 23 requests the microcomputer 80 to notify it of the refrigerant temperature measured by the temperature sensor 90. The microcomputer 80, upon receiving the request from the control unit 23, then notifies the control unit 23 of the refrigerant temperature, thereby enabling the control unit 23 of the control device 22 to obtain the refrigerant temperature.

[0053] Incidentally, in a cooling system 12 incorporating an electric valve 30, maintaining the connection (so-called connection) between the electric valve 30 and the control device 22 may increase control costs. For example, if the control device 22 sequentially calculates and determines the control amount of the connected electric valve 30, the control unit 23 of the control device 22 will incur costs for performing calculation processing. The costs required for the control device 22 to control the electric valve 30 in this manner are referred to as "control costs."

[0054] Here, the procedure by which the control device 22 and the electric valve 30 control the flow of refrigerant in the cooling system 12 according to this embodiment will be explained with reference to Figures 4 and 5.

[0055] The procedure shown in Figure 4 is executed by the control unit 23 of the control device 22 reading a program (not shown) recorded in a recording unit (not shown). The procedure shown in Figure 5 is executed by the microcomputer 80 reading a program (not shown) recorded in the flash memory 83. In this embodiment, the conditions for the control device 22 to start executing the procedure shown in Figure 4 and the conditions for the microcomputer 80 to start executing the procedure shown in Figure 5 are set as appropriate. These procedures are started, for example, when power is supplied to the control device 22 and the electric valve 30 (i.e., when the cooling system 12 is started).

[0056] (Control procedure of control device 22) First, in step S102, the control unit 23 acquires the temperature of the cooling water and the temperature of the refrigerant. More specifically, the control unit 23 acquires the temperature of the cooling water flowing through the cooling water circuit 14, which is measured by a sensor (not shown). The control unit 23 also acquires the temperature of the refrigerant from the electric valve 30. Then, the control unit 23 proceeds to step S104.

[0057] Next, in step S104, the control unit 23 determines whether control authority can be transferred to the electric valve 30. As an example, the control unit 23 determines whether the temperature of the cooling water is approaching the set temperature based on the amount of deviation of the cooling water temperature from a predetermined set temperature and the amount of change of the cooling water temperature per unit time. Also, in step S104, the control unit 23 determines that control authority can be transferred to the electric valve 30 if the temperature of the cooling water is approaching the predetermined set temperature. The amount of change of the cooling water temperature when it is determined in step S104 that the temperature of the cooling water is approaching the predetermined set temperature is set as appropriate.

[0058] Then, if the control unit 23 determines that it cannot transfer control authority to the electric valve 30, it proceeds to step S106. On the other hand, if the control unit 23 determines that it can transfer control authority to the electric valve 30, it proceeds to step S108.

[0059] Furthermore, in step S106, the control unit 23 notifies the electric valve 30 of a control command. More specifically, the control unit 23 notifies the microcomputer 80 of the electric valve 30 of a signal to drive the valve body 46. Note that the control command to drive the valve body 46 also includes the case where the valve body 46 is not driven, i.e., the case where the valve body 46 maintains its position. Then, when the control unit 23 notifies the electric valve 30 of the control command, it proceeds to step S102.

[0060] Furthermore, in step S108, the control unit 23 notifies the electric valve 30 of the target value of the refrigerant temperature and transfers control authority. More specifically, in step S108, the control unit 23 notifies the microcomputer 80 of the electric valve 30 of the target value of the refrigerant temperature when the cooling water temperature reaches a predetermined set temperature. Then, when the control unit 23 notifies the microcomputer 80 of the electric valve 30 of the target value, it proceeds to step S110.

[0061] Next, in step S110, the control unit 23 determines whether the cooling water temperature is stable or not. As an example, the control unit 23 determines whether the cooling water temperature is deviating from a predetermined set temperature based on the deviation of the cooling water temperature from the predetermined set temperature and the rate of change of the cooling water temperature per unit time. In other words, in step S110, the control unit 23 makes the same determination as in step S104. Note that the rate of change of the cooling water temperature when the control unit 23 determines in step S110 that the cooling water temperature is stable relative to the predetermined set temperature is set as appropriate.

[0062] Furthermore, if the control unit 23 has received a notification from the microcontroller 80 of the electric valve 30, it may decide to proceed to step S110 based on the contents of the notification. The specific notifications received from the microcontroller 80 in step S110 will be described later.

[0063] Then, if the control unit 23 determines that the temperature of the cooling water is not stable, that is, that the temperature of the cooling water is far from a predetermined temperature, it proceeds to step S112. On the other hand, if the control unit 23 determines that the temperature of the cooling water is stable, it proceeds to step S114.

[0064] Furthermore, in step S112, the control unit 23 acquires control authority from the electric valve 30. More specifically, in step S112, the control unit 23 notifies the electric valve 30 of a control command to acquire control authority. Then, when the control unit 23 has notified the electric valve 30 of the control command, it proceeds to step S102.

[0065] Furthermore, the control unit 23 remains on standby in step S114. In other words, the control unit 23 does not notify the electric valve 30 of a predetermined time. Then, when the predetermined time has elapsed, the control unit 23 proceeds to step S116.

[0066] Furthermore, in step S116, the control unit 23 determines whether or not to continue the control procedure. If the control unit 23 determines that the procedure is correct in step S116, it proceeds to step S110. On the other hand, if the control unit 23 determines that the procedure is incorrect in step S116, it terminates the control procedure.

[0067] Next, the control procedure for the microcontroller 80 will be explained with reference to Figure 5.

[0068] (Control procedure of microcontroller 80) First, in step S202, the microcontroller 80 determines whether or not the electric valve 30 has control authority. More specifically, the microcontroller 80 determines whether or not the control unit 23 has executed the procedure in step S108 and transferred control authority to the electric valve 30. If the microcontroller 80 determines that the result is positive in step S202, it proceeds to step S204. On the other hand, if the microcontroller 80 determines that the result is negative in step S202, it proceeds to step S216.

[0069] Furthermore, in step S204, the microcontroller 80 measures the temperature of the refrigerant. More specifically, the microcontroller 80 obtains the temperature of the refrigerant from the temperature sensor 90. Then, the microcontroller 80 proceeds to step S216.

[0070] Furthermore, in step S206, the microcomputer 80 calculates the amount of movement of the valve body 46 so that the refrigerant temperature reaches the target value. More specifically, based on the refrigerant temperature measured in step S204, the microcomputer 80 determines the amount of movement of the valve body 46 so that the refrigerant temperature reaches the target value notified by the control unit 23 in the procedure of step S108. Then, the microcomputer 80 proceeds to step S208.

[0071] Furthermore, in step S208, the microcomputer 80 drives the valve body 46 based on the calculation result of the amount of movement of the valve body 46. In other words, the microcomputer 80 drives the valve body so that the temperature of the refrigerant acquired in step S204 approaches the target value notified by the control unit 23. Then, the microcomputer 80 proceeds to step S210.

[0072] Next, in step S210, the microcontroller 80 determines whether the refrigerant temperature is within the target range. More specifically, the microcontroller 80 determines whether the measured result of the refrigerant temperature falls within the target range based on the target value notified by the control unit 23. The target range based on the target value, when the microcontroller 80 determines in step S210 that the refrigerant temperature is within the target range, is set as appropriate.

[0073] Then, if the microcomputer 80 determines that the refrigerant temperature is not within the target range, that is, that the refrigerant temperature is far from the target value, it proceeds to step S212. In other words, if the microcomputer 80 determines that the measured result of the refrigerant temperature is not within the target range based on the target value, it proceeds to step S212. On the other hand, if the microcomputer 80 determines that the refrigerant temperature is within the target range, it proceeds to step S222.

[0074] Furthermore, in step S222, the microcontroller 80 determines whether or not to continue the control procedure. If the microcontroller 80 determines that the procedure is correct in step S222, it proceeds to step S204. On the other hand, if the microcontroller 80 determines that the procedure is incorrect in step S222, it terminates the control procedure.

[0075] Furthermore, in step S212, the microcontroller 80 notifies the control device 22 of the unstable state. More specifically, in step S212, the microcontroller 80 notifies the control device 22 that the refrigerant temperature is deviating from the target value due to the influence of external disturbances, etc. In other words, the microcontroller 80 causes the control unit 23 to make a negative determination in step S110. Then, if the microcontroller 80 notifies the control device 22 of the unstable state, it proceeds to step S214.

[0076] Next, in step S214, the microcontroller 80 transfers control authority to the control device 22. In other words, the microcontroller 80 communicates with the control unit 23 to cause the control unit 23 to execute step S112. Then, if the microcontroller 80 has transferred control authority to the control device 22, it proceeds to step S222.

[0077] In step S216, the microcontroller 80 drives the valve body 46 based on the control command notified by the control unit 23. More specifically, in step S216, the microcontroller 80 drives the valve body 46 based on the control command notified by the control unit 23 by executing the procedure in step S106. Then, the microcontroller 80 proceeds to step S218.

[0078] Next, in step S218, the microcomputer 80 determines whether the refrigerant temperature is stable. More specifically, the microcomputer 80 measures the refrigerant temperature in the same manner as in step S204 and determines whether the amount of change in the refrigerant temperature per unit time is greater than a predetermined threshold. In other words, the specific threshold for when the microcomputer 80 determines that the refrigerant temperature is stable in step S218 is set as appropriate.

[0079] Then, the microcontroller 80 proceeds to step S220 if it determines that the refrigerant temperature is stable, that is, if the rate of change of the refrigerant temperature per unit time is less than a threshold. On the other hand, if the microcontroller 80 determines that the refrigerant temperature is not stable, it proceeds to step S222.

[0080] Furthermore, in step S220, the microcontroller 80 requests control authority from the control device 22. More specifically, the microcontroller 80 notifies the control device 22 to make an affirmative decision in step S110. Then, if the microcontroller 80 notifies the control device 22 of its request for control authority, it proceeds to step S222.

[0081] In this embodiment, the control unit 23 of the control device 22 and the microcomputer 80 of the electric valve 30 control the flow of refrigerant by performing the control procedure and communication described above. Here, in the procedure from step S206 to step S208, the microcomputer 80 determines the control amount of the drive device 50 and controls the drive device 50. That is, the procedure from step S206 to step S208 is an example of the "autonomous mode" in this embodiment.

[0082] Furthermore, in step S216, the microcontroller 80 controls the drive unit 50 based on the control command received from the control device 22. In other words, step S216 is an example of the "heteronomous mode" in this embodiment.

[0083] In step S220, the microcontroller 80 requests control authority from the control device 22, but the criteria for the control unit 23 to make a decision are set as appropriate. More specifically, when the control unit 23 receives a notification from the microcontroller 80 requesting control authority, the control unit 23 may be configured to make a decision in step S110 based on that request, or it may be configured to ignore the request. Also, for example, if the control unit 23 receives a notification from the microcontroller 80 requesting control authority more than a predetermined number of times, the control unit 23 may be configured to make an affirmative decision in step S110.

[0084] Furthermore, the control procedure of the control unit 23 shown in Figure 4 and the control procedure of the microcontroller 80 shown in Figure 5 are executed at the same time. For example, in Figure 4, the control unit 23 requests the electric valve 30 for the temperature of the refrigerant, but in Figure 5, the reception and notification of this request are omitted. The control unit 23 will appropriately perform the reception and notification of requests not shown in Figure 5.

[0085] Next, the operation and effects of the electric valve 30 in this embodiment will be described.

[0086] (Operation and Effects) The electric valve 30 according to this embodiment has two control methods for the microcomputer 80: an externally controlled mode in which the drive unit 50 is controlled based on a control command from the control device 22 that determines the control amount of the drive unit 50, and an autonomous mode in which the drive unit 50 is controlled based on the temperature of the refrigerant acquired by the acquisition unit. Therefore, with the electric valve 30 according to this embodiment, the temperature of the refrigerant can be controlled based on a control command even when there is no control command from the control device 22 to control the drive unit 50.

[0087] Furthermore, with respect to the cooling system 12 incorporating the electric valve 30 according to this embodiment, the frequency at which the control device 22 performs control operations can be reduced, thereby reducing the development cost of the control device 22 and the capabilities required of the control device 22. For this reason, the cooling system 12 incorporating the electric valve 30 according to this embodiment reduces development costs.

[0088] Furthermore, in this embodiment, when the microcomputer 80 controls the electric valve 30 in autonomous mode, it brings the refrigerant temperature closer to the target value notified by the control device 22. Therefore, with this embodiment, the electric valve 30 makes it easier to maintain the refrigerant temperature even without a control command notification from the control device 22, compared to when the microcomputer 80 determines the target value itself.

[0089] Furthermore, in this embodiment, the electric valve 30 notifies the control device 22 when the microcomputer 80 determines that the refrigerant temperature does not fall within the target range based on the target value. Therefore, with this embodiment, the electric valve 30 can notify the control device 22 of the refrigerant temperature if the electric valve 30 alone cannot bring the refrigerant temperature within the target range.

[0090] Furthermore, in this embodiment, the electric valve 30 is controlled by the microcomputer 80 in heteronomous mode when the refrigerant temperature does not fall within the target range based on the target value. Therefore, with this embodiment, if the electric valve 30 alone cannot bring the refrigerant temperature within the target range, it can receive a control command from the control device 22 and control the refrigerant temperature.

[0091] Furthermore, in this embodiment, the electric valve 30 has a temperature sensor 90 that measures the temperature of the refrigerant as its acquisition unit. Therefore, with this embodiment of the electric valve 30, the temperature of the refrigerant can be acquired without the control device 22.

[0092] Furthermore, the cooling system 12 according to this embodiment includes a compressor 26 that circulates a fluid that transfers thermal energy from the evaporator 18 to the condenser 16, and an electric valve 30 that controls the fluid flow. The cooling system 12 according to this embodiment also includes a control device 22 that transmits control commands to a microcomputer 80 of the electric valve 30 based on user operation. As a result, the control cost of the control device 22 is reduced for the cooling system 12 incorporating the electric valve 30 according to this embodiment, and therefore the development cost of the control device 22 and the capabilities required of the control device 22 are reduced.

[0093] (Modifications) In addition, some of the steps described above regarding the control procedure of the microcomputer 80 for controlling the temperature of the refrigerant may be omitted. More specifically, step S212 or step S214 may be omitted. Also, step S210 may be omitted, and the procedure of step S208 may be executed, after which the system proceeds to step S222. Furthermore, steps S218 and S220 may be omitted. In this case as well, the electric valve 30 can control the temperature of the refrigerant even when there is no control command from the control device 22 to control the drive device 50, as described above.

[0094] Furthermore, the order of the steps described above regarding the control procedure of the microcomputer 80 for controlling the refrigerant temperature may be changed. More specifically, steps S210 to S214 may be executed before step S206. Also, step S204 may be executed before step S202, provided that it is executed before step S206. In this case as well, the electric valve 30 can control the refrigerant temperature even when there is no control command from the control device 22 to control the drive device 50, as described above.

[0095] Furthermore, in the above description, the temperature sensor 90, which is an example of a measuring unit, measured the temperature of the refrigerant. However, the objects measured by the measuring unit in this disclosure are not limited to this. For example, instead of measuring the temperature of the refrigerant, the pressure or flow rate of the refrigerant may be measured. Also, instead of measuring the temperature or pressure of the refrigerant, the measuring unit may measure the temperature of the cooling water circulating in the cooling water circuit 14, etc.

[0096] Furthermore, in the above description, the control unit 23 of the control device 22 obtained the refrigerant temperature from the control unit 70 of the electric valve 30. However, the method by which the control unit 23 obtains the refrigerant temperature is not limited to this in this disclosure. For example, the control unit 23 may obtain the refrigerant temperature from a sensor other than the control unit 70 of the electric valve 30. In other words, the control unit 23 may measure the refrigerant temperature using a sensor different from the temperature sensor 90 used by the microcomputer 80 to measure the refrigerant temperature.

[0097] Furthermore, in the above description, a temperature sensor 90, which is an example of a measurement unit, was used as an example of a detection unit of the electric valve 30. The configuration of the detection unit in this disclosure is not limited to this. For example, the microcomputer 80 may obtain the state of the refrigerant by obtaining the temperature of the refrigerant from an external device of the electric valve 30. In other words, the electric valve 30 in this embodiment may be configured such that the microcomputer 80 obtains control indicators (control indexes or parameters) from an external device without being equipped with a temperature sensor 90.

[0098] While embodiments of this disclosure have been described above with reference to the attached drawings, it is clear that any person with ordinary skill in the art to which this disclosure belongs could conceive of various modifications or applications within the scope of the technical idea described in the claims, and these too are naturally understood to fall within the technical scope of this disclosure.

[0099] The disclosure of Japanese Patent Application No. 2024-157782, filed on 11 September 2024, is incorporated herein by reference in its entirety. All documents, patent applications, and technical standards described herein are incorporated herein by reference to the same extent as the individual documents, patent applications, and technical standards are incorporated herein by reference in the same manner as the individual documents, patent applications, and technical standards are incorporated herein by reference in the same manner as described herein.

Claims

1. An electric valve comprising: a valve body having a valve chamber and a valve port connected to the valve chamber; a valve element that moves relative to the valve port; a drive device for driving the valve element; an acquisition unit for acquiring control indicators; and a control unit for controlling the drive device, wherein the control method of the control unit includes a heteronomous mode in which the drive device is controlled based on a control command from a control device that determines the control amount of the drive device, and an autonomous mode in which the drive device is controlled by determining the control amount of the drive device based on the control indicators acquired by the acquisition unit.

2. The electric valve according to claim 1, wherein the control unit, when controlling in the autonomous mode, brings the control index closer to the target value notified by the control device.

3. The electric valve according to claim 2, wherein the control unit notifies the control device when the control index does not fall within the target range based on the target value.

4. The electric valve according to claim 3, wherein the control unit controls in the heteronomous mode when the control index does not fall within the target range based on the target value.

5. The electric valve according to claim 1, wherein the acquisition unit is a measuring unit for measuring a control index.

6. A temperature control system comprising: a pump for circulating a fluid that transfers thermal energy from a heat absorber to a heat sink; an electric valve according to any one of claims 1 to 4 for controlling the flow of the fluid; and a control device for transmitting control commands to the control unit of the electric valve by user operation.

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