Electric valve, temperature adjustment system, and control device

Abstract

An electric valve 30 comprises: a valve main body 40 that has a valve chamber 42 and a valve port 44 which is connected to the valve chamber 42; a valve body 46 that moves with respect to the valve port 44; a drive device 50 that drives the valve body 46; a motor driver 72, an angle sensor 78, and an RTC 86 that detect the state of the valve main body 40 or the drive device 50; and a control unit 70 that controls the drive device 50 on the basis of detection results of the motor driver 72, the angle sensor 78, and the RTC 86. When having determined that the necessity to replace the electric valve 30 will arise before a next inspection time T1, the control unit 70 provides notification that it is necessary to replace the electric valve 30.

Description

Electric valves, temperature control systems and control devices

[0001] The present disclosure relates to a motorized valve, a temperature regulation system, and a control device.

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

[0003] The present disclosure provides a motor-operated valve that can be prepared for replacement before the time comes when replacement becomes necessary.

[0004] The first embodiment of the electric valve is 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 that drives the valve element, and a control unit that controls the drive device based on the state of the valve body or the drive device, and when the control unit determines that the electric valve needs to be replaced by the next inspection date, it notifies the user that the electric valve needs to be replaced.

[0005] The motor-operated valve according to the first aspect includes a control unit that controls the drive device based on the state of the valve body or the drive device. Furthermore, if the control unit determines that the motor-operated valve needs to be replaced before the next inspection period, it notifies the user that the motor-operated valve needs to be replaced. Therefore, with the motor-operated valve according to this aspect, the user can prepare for the motor-operated valve replacement before the time comes when the motor-operated valve needs to be replaced.

[0006] In the second aspect of the electric valve, in the electric valve described in the first aspect, the control unit determines that the electric valve needs to be replaced if the number of times the valve body is driven from the start of use to the next inspection time exceeds a predetermined first threshold value.

[0007] In the motor-operated valve according to the second aspect, if the number of times the valve element is actuated between the start of use and the next inspection exceeds a predetermined first threshold, the control unit determines that the motor-operated valve needs to be replaced. Therefore, the motor-operated valve according to this aspect allows the user to be aware of the manufacturer's recommended replacement timing for the motor-operated valve.

[0008] In the third aspect of the electric valve, in the electric valve described in the first or second aspect, the control unit determines that the electric valve needs to be replaced when the change in a characteristic quantity that changes with use of the electric valve between the measured value at the start of use and the predicted value at the next inspection time exceeds a predetermined second threshold value.

[0009] In the motor-operated valve according to the third aspect, when the change in a feature quantity that changes with use of the motor-operated valve between a measured value at the start of use and a predicted value at the next inspection time exceeds a predetermined second threshold, the motor-operated valve according to this aspect can make the user aware of the need for replacement based on changes over time that occur with use of the motor-operated valve.

[0010] A fourth aspect of the motor-operated valve is a motor-operated valve described in any one of the first to third aspects, wherein the control unit determines that the motor-operated valve needs to be replaced when the change in the detection result of the measurement value over a predetermined period of time for a feature that changes due to use of the motor-operated valve exceeds a predetermined third threshold value.

[0011] In the motor-operated valve according to the fourth aspect, the control unit determines that the motor-operated valve needs to be replaced when a change in a measured value over a predetermined period of time for a feature that changes with use of the motor-operated valve exceeds a predetermined third threshold. Therefore, with the motor-operated valve according to this aspect, even if the motor-operated valve suddenly malfunctions during use, the user can be made aware that the motor-operated valve needs to be replaced.

[0012] The fifth aspect of the electric valve is the electric valve according to the third or fourth aspect, wherein the characteristic quantity includes at least one of the back electromotive voltage generated in the drive device, the current flowing through the drive device, the number of pulses that the drive device uses to drive the valve body, and the flow rate of the fluid flowing inside the valve body.

[0013] The sixth aspect of the electric valve is an electric valve described in any one of the first to fifth aspects, in which the control unit notifies the user that the electric valve needs to be replaced if it determines that the electric valve needs to be replaced by the next inspection date that is set after the next inspection date.

[0014] The motor-operated valve according to the sixth aspect notifies the user of the need for motor-operated valve replacement when it determines that the motor-operated valve needs to be replaced by the next inspection period that follows the next inspection period, thereby urging the user to prepare for motor-operated valve replacement.

[0015] The seventh aspect of the electric valve is an electric valve described in any one of the first to sixth aspects, wherein the control unit notifies the user that the electric valve needs to be replaced when it detects a malfunction of the valve body or the drive device.

[0016] The motor-operated valve according to the seventh aspect notifies the user that the motor-operated valve needs to be replaced when a failure of the valve body or the drive device is detected, thereby urging the user to promptly replace the motor-operated valve.

[0017] The eighth aspect of the electric valve is an electric valve described in any one of the first to seventh aspects, further comprising a detection unit that detects the state of the valve body or the drive device, and the control unit determines the need to replace the electric valve based on the detection results detected by the detection unit.

[0018] The motor-operated valve according to the eighth aspect further includes a detection unit that detects the state of the valve body or the drive unit. The control unit determines the need for replacement of the motor-operated valve based on the detection results from the detection unit. Therefore, the motor-operated valve according to this aspect has a simpler configuration than when the state of the valve body or the drive unit is detected based on the detection results from an external device of the motor-operated valve.

[0019] The temperature adjustment system of the ninth aspect includes a pump that circulates a fluid that transfers thermal energy from a heat absorber to a heat radiator, an electric valve described in any one of the first to eighth aspects that controls the flow of the fluid, and a control device that sends a control command to the control unit of the electric valve by operation of a user.

[0020] A temperature adjustment system according to a ninth aspect includes a pump that circulates a fluid that transfers thermal energy from a heat absorber to a heat radiator, and the motor-operated valve according to any one of the first to eighth aspects that controls the flow of the fluid. The temperature adjustment system according to this aspect also includes a control device that transmits a control command to a control unit of the motor-operated valve in response to a user's operation. Therefore, the temperature adjustment system according to this aspect can make it possible to recognize the need to replace the motor-operated valve included in the temperature adjustment system.

[0021] The control device of the tenth aspect is a control device that controls an electric valve that includes 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 that drives the valve element, and a control unit that controls the drive device, and when the control unit detects that it has determined that the electric valve will need to be replaced by the time of the next inspection, it notifies the user that the electric valve needs to be replaced.

[0022] A control device according to a tenth aspect includes a control unit that controls the drive device based on the state of the valve body or the drive device. Furthermore, if the control unit determines that the motor-operated valve needs to be replaced before the next inspection period, the control unit notifies the user that the motor-operated valve needs to be replaced. Therefore, with the control device according to this aspect, the user can prepare for motor-operated valve replacement before the time comes when the motor-operated valve needs to be replaced.

[0023] The control device of the eleventh aspect is the control device described in the tenth aspect, wherein the electric valve further includes a detection unit that detects the state of the valve body or the drive unit, and the control unit determines the need to replace the electric valve based on the detection results detected by the detection unit.

[0024] In a control device according to an eleventh aspect, the motor-operated valve further includes a detection unit that detects the state of the valve body or the drive unit. The control unit determines the need for replacement of the motor-operated valve based on the detection results of the detection unit. Therefore, the control device according to this aspect has a simpler configuration than when the state of the valve body or the drive unit is detected based on the detection results of a device external to the motor-operated valve.

[0025] According to the present disclosure, a motor-operated valve is provided that can be prepared for replacement before the time comes when replacement of the motor-operated valve becomes necessary.

[0026] FIG. 5 is a diagram of a chiller unit having a cooling system according to an embodiment of the present disclosure; FIG. 6 is a diagram illustrating a motor-operated valve according to the embodiment; FIG. 7 is a block diagram illustrating the configuration of the motor-operated valve according to the embodiment; FIG. 8 is a diagram illustrating the procedure by which a control unit of the motor-operated valve operates; FIG. 9 is a diagram illustrating the procedure by which a control unit of the motor-operated valve operates, following FIG. 4, and is a diagram illustrating the relationship between a measured value and a first threshold value and a second threshold value; FIG. 10 is a diagram illustrating the procedure by which a control unit of the motor-operated valve operates, following FIG. 4 and FIG. 11, and is a diagram illustrating the relationship between a measured value and a third threshold value.

[0027] This embodiment will be described below. In the following description of the drawings, identical or similar parts are designated by the same or similar reference numerals. However, the drawings are schematic, and the relationship between thickness and planar dimensions, the thickness ratio of each device or member, etc., differ from the actual ones. Therefore, specific thicknesses and dimensions should be determined with reference to the following description. Furthermore, parts with different dimensional relationships and ratios are included among the drawings.

[0028] 1 shows a chiller unit 10 having a cooling system 12 according to this embodiment. The chiller unit 10 has the cooling system 12 and a cooling water circuit 14.

[0029] The cooling system 12 is an example of a "temperature adjustment system" in this embodiment. As shown in Fig. 1, the cooling system 12 includes a control device 22, an electric valve 30, an evaporator 18, a compressor 26, and a condenser 16. The electric valve 30, the evaporator 18, the compressor 26, and the condenser 16 are connected to each other via a refrigerant pipe 20. A refrigerant, which is an example of a fluid in this embodiment, is placed inside the refrigerant pipe 20.

[0030] The compressor 26 is an example of a "pump" in this embodiment and is a device that compresses a gaseous refrigerant. The refrigerant compressed by the compressor 26 flows into the condenser 16, which is an example of a "heat radiator" in this embodiment, and is liquefied while being cooled by the fan 24. The liquefied refrigerant flows into the motor-operated valve 30.

[0031] The flow of the liquefied refrigerant is controlled by the motor-operated valve 30. More specifically, the pressure or flow rate of the refrigerant is adjusted by the motor-operated valve 30 as described below, and the refrigerant flows out. The specific configuration of the motor-operated valve 30 will be described later.

[0032] The refrigerant that flows out from the motor-operated 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 coolant flowing through the coolant circuit 14, as described below. 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.

[0033] As shown in FIG. 1, the cooling water circuit 14 includes a cooling water pipe, a liquid pump 28 that causes cooling water to flow through the cooling water pipe, and a water tank WT.

[0034] The cooling water piping is piping through which cooling water flows to cool a cooling object (not shown) that is located outside the chiller unit 10. As shown in Fig. 1, the cooling water piping is connected to an outlet through which cooling water flows out of the chiller unit 10 and an inlet through which cooling water flows into the chiller unit 10. The cooling water piping also connects the evaporator 18, the water tank WT, and the pump.

[0035] The cooling water, whose temperature has increased by cooling 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 is then flowed out of the water tank WT again by the liquid supply pump 28 to the outside of the chiller unit 10.

[0036] Next, the motor-operated valve 30 and the control device 22 in this embodiment will be described with reference to Figures 2 and 3. Figure 2 shows the motor-operated valve 30 in this embodiment, and Figure 3 shows the motor-operated valve 30 and the control device 22 in this embodiment.

[0037] 2, the motor-operated valve 30 according to this embodiment includes a valve body 40, a can 36, a valve element 46, a drive unit 50, and a control unit 70. The drive unit 50 includes a rotor 52, a stator 56, and a valve element lifting / lowering drive mechanism 54.

[0038] (Valve body 40) The valve body 40 is a cylindrical member with a bottom and 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 surface of the valve port 44, with which the valve element 46 comes into contact, as will be described later. A drive unit 50 is inserted into the valve chamber 42 from the top of the valve body 40, as will be described later.

[0039] A first inlet / outlet 32 ​​made up of a pipe joint is joined to the left side of the valve chamber 42 of the valve body 40 in the drawing. Similarly, a second inlet / outlet 34 made up of a pipe joint is joined to the lower side of the valve chamber 42 of the valve body 40 in the drawing.

[0040] (Can 36) The can 36 is a cylindrical member with a bottom. The opening side of the can 36 faces downward in the figure and is joined to the valve body 40, thereby sealing the top surface of the valve body 40. Inside the can 36, there are disposed a disk body that is fixed by being fitted into the inner wall surface of the can 36, and a shaft body 52S that is joined at one end to the disk body and extends in the vertical direction in the figure.

[0041] (Rotor 52) The rotor 52 has a cylindrical magnet, and is rotatably disposed inside the can 36 by a shaft 52S, so that it can rotate above the valve chamber 42 in the drawing. The lower part of the rotor 52 is joined to a valve element lifting / lowering drive mechanism 54.

[0042] (Valve element lifting drive mechanism 54) The valve element lifting drive mechanism 54 is a mechanism for lifting and lowering the valve element 46. More specifically, the valve element lifting drive mechanism 54 has a feed screw mechanism 54F, which converts the rotation of the rotor 52 into the vertical direction in the drawing. The feed screw mechanism 54F has a lower portion located inside the valve chamber 42. The feed screw mechanism 54F is also arranged so that its lower portion contacts the valve element 46. When the rotor 52 rotates, the valve element lifting drive mechanism 54 drives the valve element 46 in the vertical direction in the drawing.

[0043] (Valve Disk 46) As shown in the figure, the valve disk 46 is a component disposed inside the valve chamber 42, and moves relative to the valve port 44 by the operation of the valve disk lifting drive mechanism 54 described above. As shown in the figure, the valve disk 46 comes into contact with the valve seat 48 in the valve port 44 to close the valve port 44. As the valve disk 46 moves away from the valve port 44, the refrigerant flows through the valve port 44. The flow of the refrigerant is adjusted by the distance between the valve disk 46 and the valve port 44.

[0044] (Stator 56) The stator 56 is disposed on the outer periphery of the can 36, i.e., on the outside of the can 36. The stator 56 includes a yoke, a bobbin, a coil 58, a resin mold, and the like. A pulse current is applied to the coil 58 of the stator 56 from the control unit 70. The stator 56 and the rotor 52 form a stepping motor. In other words, the stator 56 drives the rotor 52 to rotate, thereby driving the valve body 46.

[0045] (Control Unit 70) As shown in FIG. 3, the control unit 70 has a regulator 74, a communication unit 76, a microcomputer 80, an angle sensor 78, and a motor driver 72.

[0046] As shown in FIG. 3, the regulator 74 is connected to the power supply Vcc and the ground Gnd, and serves as the power supply Vdd that operates the control unit 70 .

[0047] 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, the Internet, an intranet, or a public line such as a telephone line. Note that the communication means may also be communication means using sound, light, vibration, image, or the like.

[0048] The microcomputer 80 is a device that controls each part of the control unit 70. The microcomputer 80 has the functions of a computer and, as shown in Fig. 3, has a CPU 81 (Central Processing Unit), a RAM 82 (Random Access Memory), a flash memory 83, an AD converter 84, an I / O interface 85, and an 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 connected to one another by a control bus (not shown).

[0049] The CPU 81 is a central processing unit that executes various programs recorded in the flash memory 83 and controls each section. The RAM 82 serves as a work area and temporarily stores programs or data. The AD converter 84 communicates with the motor driver 72, converts analog signals received from the angle sensor 78 into digital signals, and stores the digital signals in the RAM 82. The RTC 86 is a component that continues to measure time, and transmits a time signal to the CPU 81 that indicates the time at which a signal was transmitted.

[0050] The flash memory 83 is an example of a "non-volatile memory" in this embodiment and stores various programs and data. More specifically, the flash memory 83 stores predetermined "first threshold," "second threshold," and "third threshold" values ​​that are referenced in the control procedure described below. The flash memory 83 also records the number of times the motor-operated valve 30 has been driven, in other words, the number of times the rotor 52 has been rotated in response to a control command received from the control device 22. In this embodiment, the number of times the control unit 70 has rotated the rotor 52 is an example of the "number of processes for driving the valve element 46" in this embodiment. The flash memory 83 also records past measured values ​​measured in the procedure for predicting the possibility of a failure described below.

[0051] The angle sensor 78 is a so-called Hall sensor that detects the amount of rotation (the angle of rotation including the direction of rotation) of the rotor 52. The detected amount of rotation of the rotor 52 is stored as data in the RAM 82 by the AD converter 84 of the microcomputer 80, as described above.

[0052] The motor driver 72 is electrically connected to the microcomputer 80 and the stator 56, and is a component that converts a control signal for the stator 56 received from the microcomputer 80 into a pulse signal and transmits it to the stator 56. The motor driver 72 is also capable of measuring parameters such as voltage and current of the pulse signal supplied to the stator 56 through the microcomputer 80. More specifically, the motor driver 72 is capable of measuring the back electromotive force generated when a pulse current is passed through the stator 56, as well as a current value according to the rotational torque of the rotor 52, which corresponds to the mechanical resistance when the valve element 46 is driven.

[0053] That is, the measurement of the pulse signal supplied to the stator 56 by the motor driver 72 corresponds to the "detection unit" in this embodiment. The voltage, current, and other values ​​measured by the microcomputer 80 are an example of the "detection result" in this embodiment.

[0054] The time signal from the RTC 86, i.e., the signal relating to the time the motor-operated valve 30 was in use, and the amount of rotation of the rotor 52 from the angle sensor 78 are other examples of the "detection result" in this embodiment. In other words, the RTC 86 and the angle sensor 78 are other examples of the "detection unit" in this embodiment. Note that the measurement intervals by these components are not particularly limited, but are set to be shorter than the inspection interval CI described below.

[0055] In this embodiment, the specific configuration of the control unit 70 is not limited to the above. That is, each of the above-described components may be provided as so-called hardware, or may be provided as software that functions when the microcomputer 80 executes a program.

[0056] In this embodiment, the control unit 70 is disposed adjacent to the stator 56 as shown in FIG.

[0057] (Control device 22) The control device 22 is a device that has an input unit 22I that accepts user operations, an indication unit 22O that presents the status of the chiller unit 10 to the user, and a control unit (not shown). The control device 22 is also a device that transmits control commands to the motor-operated valve 30 in response to user operations input to the input unit 22I. The input unit 22I and the indication unit 22O may have any configuration, but as an example, a touch panel is used to serve the functions of both components.

[0058] In addition, the control unit 70 of the control device 22 sends a control command to the electric valve 30 based on the temperature of the cooling water flowing through the cooling water circuit 14 measured by a sensor not shown in the figure so that the temperature of the cooling water becomes the set value input by user operation.

[0059] For example, when the temperature of the coolant flowing through the coolant circuit 14 is higher than a set value, the control device 22 sends a control command to the control unit 70 to increase the cooling capacity of the evaporator 18. The control device 22 includes the distance (coordinate value) of the motor-operated valve 30 from the valve orifice 44 in the control command to increase the opening degree (the distance between the valve orifice 44 and the valve element 46) of the motor-operated valve 30. Furthermore, based on the received control command, the control unit 70 sends a pulse signal to the stator 56 to drive the valve element 46 so that the position of the valve element 46 matches the coordinate value.

[0060] In a cooling system 12 incorporating an electric valve 30, there comes a time when the electric valve 30 needs to be replaced. For example, the feed screw mechanism 54F that drives the valve element 46 of the electric valve 30 wears with use of the electric valve 30, making it necessary to increase the rotational torque that rotates the rotor 52. In other words, wear of the feed screw mechanism 54F can increase the rotational torque required to drive the valve element 46, i.e., mechanical resistance. In such cases, as shown in Figures 5 and 6 (described below), the mechanical resistance is likely to gradually increase. In other words, when the number of uses of the electric valve 30 exceeds a predetermined number set by the manufacturer of the electric valve 30, the electric valve 30 is prone to malfunction.

[0061] If the rotor 52 becomes unable to rotate due to the increased mechanical resistance, it will lose its ability to drive the valve element 46. In this state, the motor-operated valve 30 will no longer function as a component of the cooling system 12, so it is desirable to replace the motor-operated valve 30 when it has been used more than an appropriate number of times (for example, a predetermined number of times set by the manufacturer of the motor-operated valve 30).

[0062] Here, a procedure for detecting a possible malfunction of the motor-operated valve 30 according to this embodiment will be described with reference to FIGS. 4 to 6 . This procedure is executed by the microcomputer 80 by loading a program (not shown) stored in the flash memory 83. In this embodiment, the microcomputer 80 executes this procedure at predetermined time intervals. This time interval is hereinafter referred to as the inspection interval CI. The next inspection time T1 refers to the time when one inspection interval CI has elapsed since the current time T0. Similarly, the next inspection time T2 refers to the time when two inspection intervals CI have elapsed since the current time T0. In this embodiment, the inspection interval CI is, for example, the time interval at which the user operates the control device 22 to inspect the chiller unit 10 for malfunctions. The specific value of the inspection interval CI is appropriately set by the designer of the chiller unit 10, for example.

[0063] (Procedure for Detecting Possible Malfunction) First, in step S102, the microcomputer 80 measures the number of times the motor-operated valve 30 has been driven, the magnitude of mechanical resistance, and the current time as current values. More specifically, the microcomputer 80 obtains the number of times the rotor 52 has rotated from the flash memory 83 and obtains the current time from the RTC 86. Regarding the mechanical resistance, the microcomputer 80 moves the valve disc 46 a predetermined distance and measures the power consumed in moving the valve disc 46, i.e., the pulse current. Then, the microcomputer 80 proceeds to step S102.

[0064] Next, in step S104, the microcomputer 80 determines whether the current value of the mechanical resistance exceeds a threshold value. More specifically, the microcomputer 80 determines whether the measured value of the mechanical resistance measured in step S102 exceeds a first threshold value Th1, as shown in FIG. 5 . The microcomputer 80 also determines whether the amount of change in the measured value of the mechanical resistance from the measured value IV at the time of shipping inspection exceeds a second threshold value Th2, as shown in FIG. 5 . That is, the horizontal axis of the graph of the mechanical resistance shown in FIG. 5 represents the elapsed time from the start of use of the motor-operated valve 30 to the present time, and the vertical axis of the graph represents the magnitude of the pulse current. In step S104, the microcomputer 80 makes a positive determination if the measured value of the mechanical resistance exceeds the first threshold value Th1 or if the amount of change from the measured value IV at the time of shipping inspection exceeds the second threshold value Th2. In addition, if the microcomputer 80 does not make a positive determination in step S104, the microcomputer 80 makes a negative determination.

[0065] If the microcomputer 80 makes a positive determination in step S104, the process proceeds to step S106. On the other hand, if the microcomputer 80 makes a negative determination in step S104, the process proceeds to step S108.

[0066] Next, in step S106, the microcomputer 80 notifies the controller 22 of the malfunction. More specifically, in step S106, the microcomputer 80 transmits information including information indicating that the motor-operated valve 30 has malfunctioned to the controller 22, and causes the display unit 220 of the controller 22 to indicate that the motor-operated valve 30 has malfunctioned. Any method of indication may be used, but in this embodiment, a message indicating that the motor-operated valve 30 has malfunctioned is displayed on the touch panel display. The microcomputer 80 then proceeds to step S102.

[0067] In step S108, the microcomputer 80 determines whether the change in the mechanical resistance or the number of times the motor-operated valve 30 is driven exceeds a threshold value. More specifically, the microcomputer 80 determines whether the magnitude of change in the measured mechanical resistance or the measured number of times the motor-operated valve 30 is driven within a predetermined period PP, measured in step S102, exceeds a third threshold value Th3 shown in FIG. 6 . In other words, in step S108, the microcomputer 80 determines whether the number of times the motor-operated valve 30 is used has changed suddenly. Note that the horizontal axis of the graph in FIG. 6 for the mechanical resistance represents the elapsed time from the time the motor-operated valve 30 was used to the current time, and the vertical axis of the graph represents the magnitude of the pulse current. Also, in step S108, the horizontal axis of the graph in FIG. 6 for the number of times the motor-operated valve 30 is driven represents the elapsed time from the time the motor-operated valve 30 was used to the current time, and the vertical axis of the graph represents the number of times the motor-operated valve 30 is driven. In step S108, the microcomputer 80 determines "YES" if the magnitude of the change in the mechanical resistance or the magnitude of the change in the number of times the motor-operated valve 30 is driven exceeds the third threshold value Th3. If the determination in step S108 is not affirmative, the microcomputer 80 makes a negative determination.

[0068] If the microcomputer 80 determines in step S108 that the determination is affirmative, the process proceeds to step S114. On the other hand, if the microcomputer 80 determines in step S108 that the determination is negative, the process proceeds to step S110.

[0069] Next, in step S110, the microcomputer 80 calculates a predicted value based on the past measured values ​​PM. More specifically, as shown in FIG. 5, the microcomputer 80 calculates a prediction function PF, which is a predicted change in mechanical resistance, based on the past measured values ​​PM. Any method may be used to derive the prediction function PF, but as an example, a polynomial approximation is performed based on the past measured values ​​PM, and the resulting approximation is used as the prediction function PF. In step S110, the microcomputer 80 also calculates a prediction function PF for the number of times the motor-operated valve 30 is driven.

[0070] In step S110, the microcomputer 80 calculates the measurement values ​​for the next inspection time T1 and the next next inspection time T2, which are predicted based on the prediction function PF, for the mechanical resistance and the number of times the motor-operated valve 30 is driven. The microcomputer 80 then proceeds to step S112.

[0071] Next, in step S112, the microcomputer 80 determines whether the predicted value of the next inspection time T1 exceeds a threshold value. More specifically, in step S110, the microcomputer 80 determines whether the measured value of the next inspection time T1 calculated for the mechanical resistance exceeds a first threshold value Th1 or a second threshold value Th2, as shown in FIG. 5. In step S110, the microcomputer 80 also determines whether the measured value of the next inspection time T1 calculated for the number of times the motor-operated valve 30 is actuated exceeds a first threshold value Th1 or a second threshold value Th2, as shown in FIG. 5. Then, if the microcomputer 80 determines in step S112 that at least one of the mechanical resistance or the number of times the motor-operated valve 30 is actuated exceeds the first threshold value Th1 or the second threshold value Th2, it makes a positive determination. If the microcomputer 80 does not make a positive determination in step S112, it makes a negative determination.

[0072] If the microcomputer 80 makes a positive determination in step S112, the process proceeds to step S114. On the other hand, if the microcomputer 80 makes a negative determination in step S112, the process proceeds to step S116.

[0073] Next, in step S114, the microcomputer 80 notifies the control device 22 that the motor-operated valve 30 should be replaced. More specifically, in step S114, the microcomputer 80 transmits information to the control device 22 indicating that the motor-operated valve 30 is not currently faulty (the time measured in step S102), but that it may fail by the next inspection time T1, and causes the display unit 22O of the control device 22 to indicate that the motor-operated valve 30 should be replaced by the next inspection time T1. Any method of indication may be used, but in this embodiment, a message indicating that the motor-operated valve 30 should be replaced by the next inspection time T1 is displayed on the touch panel display. Note that displaying a message on the display is an example of "notifying" in this embodiment. The microcomputer 80 then proceeds to step S102.

[0074] In step S116, the microcomputer 80 determines whether the predicted value of the next next inspection time T2 exceeds a threshold value. More specifically, in step S110, the microcomputer 80 determines whether the measured value of the next next inspection time T2 calculated for the mechanical resistance exceeds a first threshold value Th1 or a second threshold value Th2, as shown in FIG. 5 . In step S110, the microcomputer 80 also determines whether the measured value of the next next inspection time T2 calculated for the number of times the motor-operated valve 30 is driven exceeds a first threshold value Th1 or a second threshold value Th2, as shown in FIG. 5 . The microcomputer 80 then makes a positive determination in step S116 if it determines that at least one of the mechanical resistance or the number of times the motor-operated valve 30 is driven exceeds the first threshold value Th1 or the second threshold value Th2. In step S116, the microcomputer 80 makes a negative determination if it does not make a positive determination.

[0075] If the microcomputer 80 makes a positive determination in step S116, the process proceeds to step S118. On the other hand, if the microcomputer 80 makes a negative determination in step S116, the process proceeds to step S120.

[0076] Next, in step S118, the microcomputer 80 notifies the control device 22 that the motor-operated valve 30 should be replaced. More specifically, in step S118, the microcomputer 80 transmits information to the control device 22 indicating that the motor-operated valve 30 is not currently faulty (the time measured in step S102), but that it may fail by the next-next inspection time T2, and causes the display unit 22O of the control device 22 to indicate that the motor-operated valve 30 should be replaced at the next-next inspection time T2. In other words, in step S118, the microcomputer 80 causes the display unit 22O of the control device 22 to indicate that a replacement motor-operated valve 30 should be prepared at the next inspection time T1. Any method of indication may be used, but in this embodiment, the microcomputer 80 displays on the touch panel display a message indicating that the motor-operated valve 30 should be replaced at the next inspection time T1. The microcomputer 80 then proceeds to step S102.

[0077] In step S120, the microcomputer 80 determines whether to continue the procedure for detecting the possibility of a malfunction. If the determination in step S120 is affirmative, the microcomputer 80 proceeds to step S102. On the other hand, if the determination in step S120 is negative, the microcomputer 80 ends the procedure for detecting the possibility of a malfunction.

[0078] In this manner, in the motor-operated valve 30 of this embodiment, the control unit 70 determines the possibility of a malfunction based on the mechanical resistance or the number of times the motor-operated valve 30 is driven. Furthermore, the motor-operated valve 30 displays a message on the display to inform the user based on the result of the control unit 70's determination of the possibility of a malfunction. Displaying a message on the display is an example of "notifying" in this embodiment. In this embodiment, the need for replacement of the motor-operated valve 30 refers not only to a situation in which the drive unit 50 is no longer able to drive the valve element 46, as in step S104 described above, but also to a situation in which the function of changing the refrigerant flow may be lost, as in steps S112 and S116.

[0079] In the above-described procedure, mechanical resistance and the number of times the motor-operated valve 30 is driven are detected to detect possible malfunctions. However, this is not limited to this, and possible malfunctions may be detected based on other parameters. For example, the back electromotive force generated in the coil 58 of the stator 56 may be measured to detect aging deterioration of the coil 58. In this case, the vertical axis of the graphs in FIGS. 5 and 6 represents the voltage value, and the horizontal axis represents the elapsed time since the start of use, measured by the RTC 86. Other parameters include the cumulative number of pulses that the coil 58 of the stator 56 has driven the valve disc 46 and the flow rate of the fluid flowing through the valve body 40. These parameters are all examples of "feature quantities that change with use of the motor-operated valve 30" in this embodiment. The state of the drive unit 50 is detected based on the measured values ​​of these parameters. Furthermore, even if an abnormality occurs in the valve body 40 (e.g., deformation of the valve port 44), the abnormality is detected based on the measured values.

[0080] In the above-described procedure, the possibility of a malfunction is detected based on the mechanical resistance and the number of times the motor-operated valve 30 is driven, but the present invention is not limited to this and the types and number of parameters may be increased or decreased. For example, the procedure may be based only on the mechanical resistance, or only on the number of times the motor-operated valve 30 is driven. Furthermore, the other parameters described above may also be included.

[0081] Next, the operation and effect of the motor-operated valve 30 in this embodiment will be described.

[0082] (Operation and Effect) In the motor-operated valve 30 according to this aspect, the motor driver 72 and the angle sensor 78 measure the state of the valve body 40 or the drive device 50. Furthermore, if the microcomputer 80 determines based on the measurement results that replacement of the motor-operated valve 30 will be necessary before the next inspection time T1 arrives, it notifies the user that replacement of the motor-operated valve 30 is necessary. Therefore, with the motor-operated valve 30 according to this aspect, the user can prepare for replacement of the motor-operated valve 30 before the time comes when replacement of the motor-operated valve 30 will be necessary.

[0083] Furthermore, in the motor-operated valve 30 according to this aspect, if the number of times the valve element 46 is actuated from the start of use until the next inspection time T1 exceeds a predetermined first threshold value Th1, the microcomputer 80 determines that it is necessary to replace the motor-operated valve 30. Therefore, the motor-operated valve 30 according to this aspect can make the user aware of the manufacturer-recommended replacement time for the motor-operated valve 30.

[0084] Furthermore, in the motor-operated valve 30 according to this aspect, when the amount of change between the measurement result of the characteristic amount at the start of use and the measurement result of the characteristic amount at the next inspection time T1 exceeds a predetermined second threshold value Th2, the microcomputer 80 determines that the motor-operated valve 30 needs to be replaced. Therefore, the motor-operated valve 30 according to this aspect can make the user aware of the need for replacement based on changes over time that occur with use of the motor-operated valve 30 incorporated in the cooling system 12.

[0085] Furthermore, in the motor-operated valve 30 according to this aspect, when the amount of change in the measurement result of the characteristic amount over a predetermined period PP exceeds a predetermined third threshold value Th3, the microcomputer 80 determines that the motor-operated valve 30 needs to be replaced. Therefore, according to the motor-operated valve 30 according to this aspect, even if the motor-operated valve 30 that is being used and incorporated into a cooling system suddenly malfunctions, the user can be made aware that the motor-operated valve 30 needs to be replaced.

[0086] Furthermore, in the motor-operated valve 30 according to this aspect, if it is determined that replacement of the motor-operated valve 30 will be necessary by the time the next inspection time T2, which is set after the next inspection time T1, is reached, the microcomputer 80 notifies the user of the need to replace the motor-operated valve 30. Therefore, the motor-operated valve 30 according to this aspect can prompt the user to prepare for replacement of the motor-operated valve 30.

[0087] Furthermore, in the motor-operated valve 30 according to this aspect, when a failure of the valve body 40 or the drive device 50 is detected, the microcomputer 80 notifies the user that the motor-operated valve 30 needs to be replaced. Therefore, the motor-operated valve 30 according to this aspect can prompt the user to replace the motor-operated valve 30 promptly.

[0088] The motor-operated valve 30 according to this aspect also includes a configuration equivalent to a detection unit that detects the state of the valve body 40 or the drive unit 50. The control unit 70 then determines the need for replacement of the motor-operated valve 30 based on the detection results. Therefore, the motor-operated valve 30 according to this aspect has a simpler configuration than when the state of the valve body 40 or the drive unit 50 is detected based on the detection results of an external device of the motor-operated valve 30.

[0089] The cooling system 12 according to this embodiment also includes a pump that circulates a refrigerant that transfers thermal energy from the evaporator 18 to the condenser 16, and an electric valve 30 that controls the flow of the refrigerant. The cooling system 12 according to this embodiment also includes a control device 22 that sends a control command to the microcomputer 80 of the electric valve 30 in response to a user operation. Therefore, the cooling system 12 according to this embodiment can make the user aware of the need to replace the electric valve 30 included in the cooling system 12.

[0090] (Modification) Note that some of the steps described in the procedure for detecting the possibility of a malfunction of the motor-operated valve 30 may be omitted. More specifically, step S104, step S108, and step S116 may be omitted. In this case, as in the above description, the user can prepare for replacement of the motor-operated valve 30 before the time when replacement of the motor-operated valve 30 becomes necessary.

[0091] In the above description, the number of times the motor-operated valve 30 is driven is used as an example of the number of times the valve element 46 of the motor-operated valve 30 is driven. However, the "number of times the valve element 46 is driven" in this embodiment is not limited to this. For example, the integrated value of the number of times the control unit 70 has performed initialization to recognize the position of the valve element 46, or the total number of pulses transmitted by the control unit 70 to the stator 56 may be used.

[0092] In the above description, the motor-operated valve 30 has a configuration equivalent to a "detection unit" that detects the state of the valve element 46 or the drive unit 50. In the present embodiment, the motor-operated valve 30 does not need to have a configuration equivalent to a detection unit. For example, an external device may detect the state of the valve element 46 or the drive unit 50, and the control unit 70 may perform control based on the results detected by the external device.

[0093] The first threshold value Th1, the second threshold value Th2, and the third threshold value Th3 in the above description may be set to any specific value. The first threshold value Th1, the second threshold value Th2, and the third threshold value TH3 may be set as values ​​determined based on test results for the motor-operated valve 30, or may be set as values ​​determined based on a ratio to a value at the start of use, for example. In the present disclosure, the "amount of change" refers to a value of change over time associated with use of the motor-operated valve 30, and includes a difference between measured values ​​(i.e., an absolute value) and a ratio between measured values ​​(i.e., a relative value).

[0094] The above describes an embodiment of the present disclosure with reference to the accompanying drawings. However, it is clear that a person with ordinary knowledge in the field of technology to which the present disclosure pertains can conceive of various modifications or applications within the scope of the technical ideas set forth in the claims, and it is understood that these also naturally fall within the technical scope of the present disclosure.

[0095] The disclosure of Japanese Patent Application No. 2024-134467, filed on August 9, 2024, is incorporated herein by reference in its entirety. All documents, patent applications, and technical standards mentioned herein are incorporated herein by reference to the same extent as if each individual document, patent application, and technical standard were specifically and herein indicated to be incorporated by reference.

Claims

1. A motor-operated 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 that drives the valve element; and a control unit that controls the drive device based on the state of the valve body or the drive device, wherein the control unit issues a notice that the motor-operated valve needs to be replaced if it determines that the motor-operated valve needs to be replaced by the time of the next inspection.

2. The motor-operated valve according to claim 1, wherein the control unit determines that the motor-operated valve needs to be replaced if the number of times the valve element is driven from the start of use until the next inspection time exceeds a predetermined first threshold value.

3. The motor-operated valve according to claim 1, wherein the control unit determines that the motor-operated valve needs to be replaced when the change in a characteristic quantity that changes with use of the motor-operated valve between the measured value at the start of use and the predicted value at the next inspection time exceeds a predetermined second threshold value.

4. The motor-operated valve according to claim 1, wherein the control unit determines that the motor-operated valve needs to be replaced when the amount of change in the measured value over a predetermined period of time for a feature that changes with use of the motor-operated valve exceeds a predetermined third threshold value.

5. The motor-operated valve according to claim 3 or claim 4, wherein the characteristic quantity includes at least one of the back electromotive voltage generated in the drive device, the current flowing through the drive device, the number of pulses that the drive device uses to drive the valve body, and the flow rate of the fluid flowing inside the valve body.

6. The motor-operated valve according to claim 1, wherein the control unit notifies the user that the motor-operated valve needs to be replaced if it determines that the motor-operated valve needs to be replaced by the next inspection time that is set after the next inspection time.

7. The motor-operated valve according to claim 1, wherein the control unit notifies the user that the motor-operated valve needs to be replaced when a malfunction of the valve body or the drive device is detected.

8. The motor-operated valve according to claim 1, further comprising a detection unit that detects the state of the valve body or the drive unit, and the control unit determines the need for replacement of the motor-operated valve based on the detection results detected by the detection unit.

9. A temperature adjustment system comprising: a pump that circulates a fluid that transfers thermal energy from a heat sink to a heat radiator; an electric valve according to claim 1 that controls the flow of the fluid; and a control device that transmits a control command to the control unit of the electric valve in response to a user's operation.

10. A control device for controlling 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 that drives the valve element, and a control unit that controls the drive device, wherein the control device notifies the user that the electric valve needs to be replaced when the control unit detects that the electric valve needs to be replaced by the time of the next inspection.

11. The control device according to claim 10, wherein the motor-operated valve has a detection unit that detects the state of the valve body or the drive unit, and the control unit determines the need for replacement of the motor-operated valve based on the detection results detected by the detection unit.

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