Electric valve control device and electric valve device

Abstract

Provided are an electrically operated valve control device and an electrically operated valve device capable of more accurately detecting a malfunction of a stepping motor of an electrically operated valve. The electric valve device (1) is provided with an electric valve (5) and an electric valve control device (100). The electric valve (5) is provided with a stepping motor (66), and the stepping motor (66) is provided with a magnetic rotor (31), an A-phase stator (61) and a B-phase stator (62). An electric valve control device (100) controls, by PWM, an A-phase current (Ia) supplied to an A-phase coil (61c) of an A-phase stator (61) and a B-phase current (Ib) supplied to a B-phase coil (62c) of a B-phase stator (62). An electrically operated valve control device (100) detects that an abnormality has occurred in an A-phase coil (61c) or a B-phase coil (62c) on the basis of a comparison between an A-phase duty ratio (Da) of an A-phase current (Ia) and a B-phase duty ratio (Db) of a B-phase current (Ib).

Description

Technical Field

[0001] The invention relates to an electric valve control device and an electric valve device having an electric valve and the electric valve control device. Background Art

[0002] Patent Document 1 discloses an example of a conventional electric valve. The electric valve includes a housing, a magnetic rotor, and a stator. The magnetic rotor is disposed inside the housing. The stator is disposed outside the housing. The magnetic rotor and the stator constitute a stepping motor.

[0003] Electric valves are incorporated into air conditioning systems, for example, and are used to control the flow rate of refrigerant. The coil of the electric valve stator may have an abnormality. The abnormality includes short circuit, partial short circuit and short circuit. If the coil has an abnormality, the electric valve may malfunction.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Publication No. 2018-179133

[0007] Patent Document 2: Japanese Patent Application Publication No. 2020-178500

[0008] Technical problem to be solved by the invention

[0009] Patent document 2 discloses an example of a fault diagnosis device capable of detecting a short circuit of a coil of a stepping motor. The fault diagnosis device detects a short circuit based on the magnitude of the current flowing to the coil. However, the magnitude of the current flowing to the coil may change due to changes in the drive voltage of the stepping motor, the ambient temperature, etc. Therefore, the fault diagnosis device may mistakenly detect a fault in the stepping motor. Summary of the invention

[0010] Therefore, an object of the present invention is to provide an electric valve control device and an electric valve device capable of more accurately detecting a failure of a stepping motor of an electric valve.

[0011] Technical means for solving technical problems

[0012] In order to achieve the above-mentioned purpose, an electric valve control device of one embodiment of the present invention controls an electric valve, wherein the electric valve has: a valve body having a valve chamber, a valve core arranged in the valve chamber, and a stepper motor for moving the valve core, the stepper motor having a magnetic rotor, an A-phase stator, and a B-phase stator, the electric valve control device controls the A-phase current supplied to the A-phase coil of the A-phase stator and the B-phase current supplied to the B-phase coil of the B-phase stator by PWM, the electric valve control device detects an abnormality in the A-phase coil or the B-phase coil based on a comparison of the duty cycle of the A-phase current and the duty cycle of the B-phase current, hereinafter, the duty cycle of the A-phase current is referred to as the A-phase duty cycle, and the duty cycle of the B-phase current is referred to as the B-phase duty cycle.

[0013] In the present invention, preferably, the electric valve control device compares: the A-phase duty cycle of the A-phase current controlled to be equal to the A-phase current target value and the B-phase duty cycle of the B-phase current controlled to be equal to the B-phase current target value, and the B-phase current target value is the same size as the A-phase current.

[0014] In the present invention, preferably, the electric valve control device compares the A-phase duty ratio and the B-phase duty ratio when the A-phase current and the B-phase current are controlled to rotate the magnet rotor.

[0015] In the present invention, it is preferred that the multiple pulses have a sequence, and the A-phase current target value and the B-phase current target value are set for the multiple pulses respectively. When the A-phase current equal to the A-phase current target value set for the multiple pulses is supplied to the A-phase coil in the sequence, and the B-phase current equal to the B-phase current target value set for the multiple pulses is supplied to the B-phase coil in the sequence, the magnetic rotor rotates, and the electric valve control device compares: the A-phase duty cycle of the A-phase current controlled to be equal to the A-phase current target value set for one of the multiple pulses and the B-phase duty cycle of the B-phase current controlled to be equal to the B-phase current target value set for other pulses of the multiple pulses, and the B-phase current target value is the same size as the A-phase current target value set for the one pulse.

[0016] In order to achieve the above-mentioned purpose, another embodiment of the present invention is an electric valve control device, which controls an electric valve, wherein the electric valve has: a valve body having a valve chamber, a valve core arranged in the valve chamber, and a stepper motor for moving the valve core, the stepper motor having a magnetic rotor, an A-phase stator, and a B-phase stator. The electric valve control device controls the A-phase voltage supplied to the A-phase coil of the A-phase stator and the B-phase voltage supplied to the B-phase coil of the B-phase stator by PWM. The electric valve control device detects an abnormality in the A-phase coil or the B-phase coil based on a comparison of the duty cycle of the A-phase voltage and the duty cycle of the B-phase voltage.

[0017] In order to achieve the above-mentioned object, an electric valve device according to another aspect of the present invention includes the electric valve and the electric valve control device.

[0018] Effects of the Invention

[0019] The electric valve control device controls the A-phase current supplied to the A-phase coil of the A-phase stator and the B-phase current supplied to the B-phase coil of the B-phase stator by PWM. The electric valve control device detects abnormality in the A-phase coil or the B-phase coil based on comparison of the duty ratio of the A-phase current (A-phase duty ratio) and the duty ratio of the B-phase current (B-phase duty ratio).

[0020] In a structure that controls the current supplied to the coil by PWM, when the resistance value and inductance (hereinafter referred to as "impedance") of the coil change, the duty cycle of the PWM signal also changes. For example, when the driving voltage and ambient temperature of the stepper motor change, the duty cycle of the A phase and the duty cycle of the B phase change together. In this case, the relationship between the duty cycle of the A phase and the duty cycle of the B phase does not change. Then, when an abnormality occurs in the A phase coil or the B phase coil, the impedance of the A phase coil or the impedance of the B phase coil changes, and the duty cycle of the A phase or the duty cycle of the B phase changes. In this case, the relationship between the duty cycle of the A phase and the duty cycle of the B phase changes. Therefore, when the electric valve control device compares the duty cycle of the A phase and the duty cycle of the B phase and the relationship changes, it can be determined that the A phase coil or the B phase coil has an abnormality. Therefore, the false detection of the abnormality of the coil caused by the change of the driving voltage and ambient temperature of the stepper motor is suppressed, so that the failure of the stepper motor can be detected more accurately. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 1 is a block diagram of an air conditioning system including an electric valve device according to an embodiment of the present invention.

[0022] Figure 2 It is a cross-sectional view of the electric valve device.

[0023] Figure 3 It is a diagram for explaining a magnetic rotor and a stator of an electric valve device.

[0024] Figure 4 This is a diagram for explaining a microcomputer, a stepping motor, and a magnetic sensor of an electric valve device.

[0025] Figure 5 This is a diagram for explaining the CPU of a microcomputer and a motor driver.

[0026] Figure 6 It is a diagram showing an example of a waveform of a PWM signal.

[0027] Figure 7 This is a diagram showing an example of the correspondence between a plurality of pulses and the A-phase current target value and the B-phase current target value.

[0028] Figure 8 This is a diagram showing an example of a current waveform of an A-phase current flowing to an A-phase coil and a current waveform of a B-phase current flowing to a B-phase coil.

[0029] Fig. 9 This is a flowchart showing an example of processing executed by the electric valve control device. DETAILED DESCRIPTION

[0030] Below, refer to Figures 1 to 9 An electric valve device according to an embodiment of the present invention will be described.

[0031] Figure 1 1 is a block diagram of an air conditioning system including an electric valve device according to an embodiment of the present invention. Figure 2 It is a cross-sectional view of the electric valve device. Figure 3 1 is a diagram illustrating a magnetic rotor and a stator of an electric valve device. Figure 3 In FIG. 1 , the magnetic poles of the magnetic rotor and the pole teeth of the stator are schematically shown. Figure 3 In the figure, the radial outer side corresponds to the upper side, and the radial inner side corresponds to the lower side. Figure 4 This is a diagram for explaining a microcomputer, a stepping motor, and a magnetic sensor of an electric valve device. Figure 4 The connection relationship between the microcomputer, stepping motor and magnetic sensor is schematically shown. Figure 5 This is a diagram for explaining the CPU of a microcomputer and a motor driver. Figure 5 The connection relationship between the CPU and the motor driver is schematically shown. Figure 6 It is a diagram showing an example of a waveform (voltage waveform) of a PWM signal. Figure 7 This is a diagram showing an example of the correspondence between a plurality of pulses and the A-phase current target value and the B-phase current target value. Figure 8 This is a diagram showing an example of a current waveform of an A-phase current flowing to an A-phase coil and a current waveform of a B-phase current flowing to a B-phase coil. Fig. 9 This is a flowchart showing an example of processing executed by the electric valve control device.

[0032] The electric valve device 1 of the present embodiment includes an electric valve 5 and an electric valve control device (hereinafter simply referred to as a “control device 100 ”).

[0033] The electric valve device 1 is incorporated, for example, into Figure 1 The air conditioning system 400 shown. The air conditioning system 400 has a compressor 401, a condenser 402, an electric valve device 1 (electric valve 5), and an evaporator 403 connected in sequence via a pipe 405. The air conditioning system 400 has an air conditioning control device 410. The air conditioning control device 410 is an external device. The air conditioning control device 410 is connected to the electric valve device 1 (control device 100) via a communication bus 420 in a manner capable of communication. The air conditioning control device 410 uses the electric valve device 1 to control the flow rate of the refrigerant flowing in the pipe 405.

[0034] like Figure 2 As shown, the electric valve 5 includes a valve body 10 , a can 20 , a drive mechanism 30 , a valve element 40 , a permanent magnet 45 , and a stator unit 50 .

[0035] The valve body 10 is made of a metal such as aluminum alloy. The valve body 10 includes a main body part 11, a support part 12 and a connecting part 13. The main body part 11 has a rectangular parallelepiped shape. The main body part 11 has a mounting hole 11a. The mounting hole 11a is arranged on the upper surface 11b of the main body part 11. The support part 12 has a cylindrical shape. The lower part of the support part 12 is arranged on the mounting hole 11a. The support part 12 is mounted on the main body part 11 using a threaded structure. The upper part of the support part 12 protrudes from the upper surface 11b of the main body part 11. The main body part 11 has a valve chamber 14, a flow path 15, a flow path 16, a valve port 17 and a valve seat 18. The flow path 15 is connected to the valve chamber 14. The flow path 16 is connected to the valve chamber 14 via the valve port 17. The valve seat 18 surrounds the valve port 17 in the valve chamber 14. The connecting part 13 has a circular ring plate shape. The upper portion of the support member 12 is joined to the inner peripheral edge of the connecting member 13 .

[0036] The can body 20 is made of metal such as stainless steel, for example. The can body 20 has a cylindrical shape. The upper end of the can body 20 is closed and the lower end is open. The lower end of the can body 20 is joined to the outer peripheral edge of the connecting member 13.

[0037] The drive mechanism 30 moves the valve body 40 in the up-down direction (the direction of the axis L). The drive mechanism 30 includes a magnet rotor 31 , a valve shaft holder 32 , a guide bush 33 , and a valve shaft 34 .

[0038] The magnetic rotor 31 has a cylindrical shape. The outer diameter of the magnetic rotor 31 is slightly smaller than the inner diameter of the tank body 20. A small gap is formed between the inner circumferential surface of the tank body 20 and the outer circumferential surface of the magnetic rotor 31. The magnetic rotor 31 has a plurality of magnetic poles (a plurality of N poles, a plurality of S poles). A plurality of N poles and a plurality of S poles are arranged on the outer circumferential surface of the magnetic rotor 31. The plurality of N poles and the plurality of S poles extend in the up and down directions. The plurality of N poles and the plurality of S poles are alternately arranged at equal intervals in the circumferential direction. In the present embodiment, the magnetic rotor 31 has twelve N poles and twelve S poles. The interval (angle) between adjacent N poles and S poles is 15 degrees.

[0039] The valve shaft holder 32 has a cylindrical shape. The upper end of the valve shaft holder 32 is blocked and the lower end is open. A support ring 35 is fixed to the upper part of the valve shaft holder 32. The support ring 35 connects the magnetic rotor 31 and the valve shaft holder 32. The valve shaft holder 32 rotates together with the magnetic rotor 31. An internal thread 32c is provided on the inner circumferential surface of the valve shaft holder 32.

[0040] The guide bushing 33 integrally includes a first cylindrical portion 33a and a second cylindrical portion 33b. The outer diameter of the second cylindrical portion 33b is smaller than the outer diameter of the first cylindrical portion 33a. The second cylindrical portion 33b is coaxially connected to the upper end of the first cylindrical portion 33a. An external thread 33c is provided on the outer peripheral surface of the second cylindrical portion 33b. The external thread 33c is screwed into the internal thread 32c of the valve shaft retainer 32. The first cylindrical portion 33a is pressed into the fitting hole 12a provided in the support member 12 of the valve body 10. The guide bushing 33 is combined with the valve body 10.

[0041] A movable stopper 32s is fixed to the valve shaft holder 32. A fixed stopper 33s is fixed to the first cylindrical portion 33a of the guide bushing 33. When the movable stopper 32s contacts the fixed stopper 33s, the rotation of the valve shaft holder 32 (i.e., the magnetic rotor 31) in the valve closing direction is restricted. The movable stopper 32s and the fixed stopper 33s constitute a stopper mechanism 38. The stopper mechanism 38 restricts the rotation of the magnetic rotor 31 in the valve closing direction.

[0042] The valve shaft 34 integrally includes a first portion 34a and a second portion 34b. The first portion 34a and the second portion 34b have a cylindrical shape. The diameter of the second portion 34b is smaller than that of the first portion 34a. The second portion 34b is coaxially connected to the upper end of the first portion 34a. The second portion 34b passes through the valve shaft holder 32. A thrust nut 36 for preventing disengagement is installed on the second portion 34b. The valve shaft 34 is arranged on the inner side of the guide bushing 33 and the inner side of the support member 12. The lower end of the first portion 34a is arranged in the valve chamber 14. The valve shaft 34 has a step portion 34d. The step portion 34d is arranged at the connection portion between the first portion 34a and the second portion 34b. A valve closing spring 37 is arranged between the step portion 34d and the valve shaft holder 32. The valve closing spring 37 is a compression coil spring. The valve closing spring 37 pushes the valve shaft 34 downward.

[0043] The valve element 40 is disposed in the valve chamber 14. The valve element 40 is opposed to the valve port 17 in the vertical direction. The valve element 40 opens and closes the valve port 17. The valve element 40 is connected to the lower end of the valve shaft 34. For example, the valve shaft 34 and the valve element 40 are integrally formed by cutting a cylindrical workpiece.

[0044] The permanent magnet 45 is arranged above the magnetic rotor 31 on the inner side of the tank body 20. The permanent magnet 45 has a circular ring plate shape. The permanent magnet 45 has an N pole and an S pole. The N pole and the S pole are arranged to be opposite to each other in the radial direction. The permanent magnet 45 is supported by a guide member 46 mounted on the support ring 35. The guide member 46 supports the permanent magnet 45 so that it can move relative to the guide member 46 in the up and down directions. The permanent magnet 45 transmits the rotation of the magnetic rotor 31 via the guide member 46. The permanent magnet 45 rotates together with the magnetic rotor 31. A support spring 47 is arranged between the permanent magnet 45 and the guide member 46. The support spring 47 is a compression coil spring. The support spring 47 pushes the permanent magnet 45 upward. A sliding member 48 is embedded in the inner side of the permanent magnet 45. The sliding member 48 protrudes from the upper surface of the permanent magnet 45. The sliding member 48 is made of, for example, an engineering plastic with a relatively small friction coefficient.

[0045] The permanent magnet 45 is pushed upward by the support spring 47, and the sliding member 48 is always in contact with the inner surface of the tank body 20. Even if the magnetic rotor 31 is moved in the vertical direction by the thread feed action of the internal thread 32c of the valve shaft holder 32 and the external thread 33c of the guide bushing 33, the position of the permanent magnet 45 in the vertical direction is constant.

[0046] The stator unit 50 has a stator 60 and a housing 70 .

[0047] The stator 60 has a cylindrical shape and includes an A-phase stator 61 and a B-phase stator 62 .

[0048] The A-phase stator 61 has a plurality of pole claw-type pole teeth 61a and 61b on the inner circumference. The top of the pole tooth 61a faces downward, and the top of the pole tooth 61b faces upward. The pole teeth 61a and the pole teeth 61b are alternately arranged at equal intervals along the circumferential direction. In this embodiment, the A-phase stator 61 has twelve pole teeth 61a and twelve pole teeth 61b. The angle between the adjacent pole teeth 61a and pole teeth 61b is 15 degrees. The A-phase stator 61 has an A-phase coil 61c. When the A-phase coil 61c is energized, the pole teeth 61a and the pole teeth 61b become different polarities.

[0049] The B-phase stator 62 has a plurality of pole claw-type pole teeth 62a and 62b on the inner circumference. The top of the pole tooth 62a faces downward, and the top of the pole tooth 62b faces upward. The pole teeth 62a and the pole teeth 62b are alternately arranged at equal intervals along the circumferential direction. In the present embodiment, the B-phase stator 62 has twelve pole teeth 62a and twelve pole teeth 62b. The angle between the adjacent pole teeth 62a and pole teeth 62b is 15 degrees. The B-phase stator 62 has a B-phase coil 62c. When the B-phase coil 62c is energized, the pole teeth 62a and the pole teeth 62b become different polarities. The B-phase stator 62 has the same structure as the A-phase stator 61 (including substantially the same). The designed impedance (resistance value and inductance) of the B-phase coil 62c is the same as the designed impedance of the A-phase coil 61c. That is, when the A-phase coil 61c and the B-phase coil 62c are normal, their impedances are the same.

[0050] The A-phase stator 61 and the B-phase stator 62 are coaxially arranged. The A-phase stator 61 and the B-phase stator 62 are in contact with each other. When viewed from the axis L, the angle between the pole teeth 61a of the A-phase stator 61 and the pole teeth 62a of the B-phase stator 62 adjacent to each other is 7.5 degrees. The A-phase coil 61c and the B-phase coil 62c are connected to a plurality of terminals 65.

[0051] The housing 70 is made of synthetic resin. The housing 70 has a rectangular box shape. The housing 70 accommodates the stator 60. The tank 20 is arranged inside the stator 60 and inside the housing 70. The stator 60 and the magnetic rotor 31 constitute a stepping motor 66 for driving the valve core 40. The housing 70 is provided with a connector 83 protruding in a lateral direction (a direction perpendicular to the axis L).

[0052] In the electric valve 5, the center axes of the main body component 11 (valve port 17, valve seat 18), support component 12, connecting component 13, tank body 20, magnetic rotor 31, valve shaft 34, valve core 40, permanent magnet 45, and stator 60 (A phase stator 61, B phase stator 62) are consistent with the axis L.

[0053] In the electric valve 5, when the magnetic rotor 31 rotates in the valve closing direction, the magnetic rotor 31 and the valve shaft holder 32 are moved downward by the thread feed action of the internal thread 32c of the valve shaft holder 32 and the external thread 33c of the guide bushing 33. The valve shaft holder 32 pushes the valve shaft 34 downward via the valve closing spring 37. The valve shaft 34 and the valve core 40 move downward and the valve core 40 contacts the valve seat 18. The position of the magnetic rotor 31 at this time is the valve closing position Rc. When the magnetic rotor 31 further rotates in the valve closing direction from this state, the valve closing spring 37 is compressed, so that the magnetic rotor 31 and the valve shaft holder 32 move further downward. The valve core 40 does not move downward. Then, when the movable stopper 32s contacts the fixed stopper 33s, the rotation of the magnetic rotor 31 in the valve closing direction is restricted. The position of the magnetic rotor 31 at this time is the reference position Rx.

[0054] In the electric valve 5, when the magnetic rotor 31 rotates in the valve opening direction, the magnetic rotor 31 and the valve shaft holder 32 move upward by the thread feed action of the internal thread 32c of the valve shaft holder 32 and the external thread 33c of the guide bushing 33. The valve shaft holder 32 pushes the thrust nut 36 upward. The valve shaft 34 and the valve core 40 move upward and the valve core 40 leaves the valve seat 18. When the magnetic rotor 31 further rotates in the valve opening direction, the magnetic rotor 31 reaches the fully open position Rz. When the magnetic rotor 31 is at the fully open position Rz, the valve core 40 is farthest from the valve port 17.

[0055] The control device 100 includes a control substrate 110 , a magnetic sensor 115 , and a microcomputer 120 .

[0056] The control board 110 is a printed circuit board on which electronic components are mounted. The control board 110 is housed in the housing 70. The control board 110 is arranged in the horizontal direction above the can body 20. The control board 110 is connected to the plurality of terminals 65 of the stator 60 via wires 111. The control board 110 is mounted with a magnetic sensor 115 and a microcomputer 120.

[0057] The magnetic sensor 115 is arranged in the vertical direction with the permanent magnet 45 sandwiched between the tank body 20. In other words, the magnetic sensor 115 is opposite to the permanent magnet 45 in the vertical direction with the tank body 20 sandwiched between them. The magnetic sensor 115 detects the magnetic field generated by the permanent magnet 45. The magnetic sensor 115 outputs a signal (analog signal) corresponding to the rotation angle of the magnetic field. That is, the magnetic sensor 115 is a rotation angle sensor that outputs a signal corresponding to the rotation angle of the permanent magnet 45 (i.e., the magnetic rotor 31). In addition, as the magnetic sensor 115, one or more Hall ICs that output binary signals can also be used.

[0058] like Figure 1 , Figure 4As shown, the microcomputer 120 is, for example, a microcomputer for embedded devices that integrates a CPU 121 as a central processing unit, a nonvolatile memory 122, a motor driver 123, a working memory 124, a communication module 125, a temperature sensor 126, etc. in one package. The microcomputer 120 is responsible for controlling the electric valve 5. In addition, the nonvolatile memory, the working memory, the communication module, the motor driver, and the temperature sensor may also be separate electronic components externally connected to the microcomputer 120.

[0059] The CPU 121 executes the program stored in the nonvolatile memory 122 and functions as various functional units. The current position of the magnetic rotor 31 before the power of the CPU 121 is about to be cut off is stored in the nonvolatile memory 122. When the power of the CPU 121 is turned on, the CPU 121 reads the current position of the magnetic rotor 31 from the nonvolatile memory 122. The working memory 124 stores variables used by the functional units. The communication component 125 is connected to the air conditioning control device 410 via the communication bus 420. The temperature sensor 126 outputs a signal corresponding to the ambient temperature K of the microcomputer 120 (i.e., the air temperature inside the housing 70). The motor driver 123 is connected to the stepping motor 66. Specifically, as Figure 4 As shown, the motor driver 123 is connected to the A-phase coil 61c and the B-phase coil 62c. The motor driver 123 supplies current to the A-phase coil 61c and the B-phase coil 62c.

[0060] like Figure 5 As shown, the motor driver 123 has H-bridge circuits 123A and 123B, and drives the stepping motor 66 in a two-stage manner.

[0061] The H-bridge circuit 123A is connected to the A-phase coil 61c. The H-bridge circuit 123A includes switches SW11, SW12, SW13, and SW14. When current flows from the terminal A1 of the A-phase coil 61c to the terminal A2, the switches SW11 and SW14 are turned on, and the switches SW12 and SW13 are turned off. When current flows from the terminal A2 of the A-phase coil 61c to the terminal A1, the switches SW12 and SW13 are turned on, and the switches SW11 and SW14 are turned off.

[0062] The H-bridge circuit 123A is connected to the reference potential (GND) via the current detection resistor 127A. A voltage Va corresponding to the current (A-phase current Ia) supplied to the A-phase coil 61c is generated at the terminals of the current detection resistor 127A. The terminals of the current detection resistor 127A are connected to the CPU 121 via an amplifier and an analog-to-digital converter 128A not shown. The CPU 121 inputs a pulse width modulation (PWM) signal to the switches SW11, SW12, SW13, and SW14. The CPU 121 adjusts the duty cycle (A-phase duty cycle Da) of the PWM signal input to the switches SW11, SW12, SW13, and SW14 so that the voltage Va becomes a value corresponding to the A-phase current target value Ita. The CPU 121 controls the A-phase current Ia in a PWM manner.

[0063] The H-bridge circuit 123B is connected to the B-phase coil 62c. The H-bridge circuit 123B includes switches SW21, SW22, SW23, and SW24. When current flows from the terminal B1 of the B-phase coil 62c to the terminal B2, the switches SW21 and SW24 are turned on, and the switches SW22 and SW23 are turned off. When current flows from the terminal B2 of the B-phase coil 62c to the terminal B1, the switches SW22 and SW23 are turned on, and the switches SW21 and SW24 are turned off.

[0064] The H-bridge circuit 123B is connected to the reference potential (GND) via the current detection resistor 127B. A voltage Vb corresponding to the current (B-phase current Ib) supplied to the B-phase coil 62c is generated at the terminal of the current detection resistor 127B. The terminals of the current detection resistor 127B are connected to the CPU 121 via an amplifier and an analog-to-digital converter 128B not shown. The CPU 121 inputs a PWM signal to switches SW21, SW22, SW23, and SW24. The CPU 121 adjusts the duty cycle (B-phase duty cycle Db) of the PWM signal input to the switches SW21, SW22, SW23, and SW24 so that the voltage Vb becomes a value corresponding to the B-phase current target value Itb. The CPU 121 controls the B-phase current Ib in a PWM manner.

[0065] The PWM signal is turned on, off, or on and off at a specified pulse period Tp. The duty cycle of the PWM signal is the ratio of the pulse period Tp to the on time Ton of the PWM signal (Ton / Tp). When the duty cycle is 0%, the PWM signal is off during the entire pulse period Tp. When the duty cycle is 30%, the PWM signal is on for 30% of the pulse period Tp and off for 70% of the pulse period Tp. When the duty cycle is 100%, the PWM signal is on for the entire pulse period Tp.

[0066] As long as the magnitude (absolute value) of the current flowing to the A-phase coil 61c is the same, the A-phase duty cycle Da is the same even if the direction of the current is different. The direction of the current is from terminal A1 to terminal A2 or from terminal A2 to terminal A1. The impedance of the A-phase coil 61c (the impedance between terminal A1 and terminal A2) changes when an abnormality occurs in the A-phase coil 61c. Abnormalities include short circuits, partial short circuits, and open circuits. Moreover, when the impedance of the A-phase coil 61c changes, the time required for a specified amount of current to flow to the A-phase coil 61c changes. Therefore, when an abnormality occurs in the A-phase coil 61c, the on-time Ton changes and the A-phase duty cycle Da changes. For example, when the impedance of the A-phase coil 61c becomes smaller, the rise time and fall time of the current flowing to the A-phase coil 61c according to the PWM signal become shorter, and the specified amount of current flows in a shorter time. Therefore, the on-time Ton becomes shorter. The rise time is the time it takes for the current to change from 0 to the maximum value, and the fall time is the time it takes for the current to change from the maximum value to 0. In Figure 6 (A) schematically shows the waveform (voltage waveform) of the PWM signal before the short circuit. Figure 6 The waveform of the PWM signal after the short circuit is schematically shown in (B). The B-phase coil 62c is the same as the A-phase coil 61c.

[0067] The magnetic rotor 31 is rotated by inputting a plurality of pulses P (P[1] to P[8]) to the stepping motor 66. Specifically, the magnetic rotor 31 is rotated by supplying a current corresponding to the pulses P to the stator 60 of the stepping motor 66. In this specification, "inputting pulses P to the stepping motor 66" is synonymous with "supplying a current corresponding to the pulses P to the stator 60 of the stepping motor 66". The plurality of pulses P have a sequence and are repeatedly input to the stepping motor 66 in ascending or descending order.

[0068] For the plurality of pulses P, the A-phase current target value Ita and the B-phase current target value Itb are set respectively. Figure 7 The corresponding relationship between the pulse P and the A-phase current target value Ita and the B-phase current target value Itb is shown in FIG. Figure 8 Schematically shows the current waveforms of the A-phase current Ia and the B-phase current Ib flowing in the order of a plurality of pulses P. Figure 8 In the above, the A-phase current Ia is a current whose magnitude and direction are the same as the A-phase current target value Ita, and the B-phase current Ib is a current whose magnitude and direction are the same as the B-phase current target value Itb. Figure 7 , Figure 8 In the diagram, the symbol (+ / -) indicates the direction of current flow. "+" indicates the direction from terminal A1 to terminal A2 or from terminal B1 to terminal B2. "-" indicates the direction from terminal A2 to terminal A1 or from terminal B2 to terminal B1. "0" indicates that current does not flow (disconnected).

[0069] In this embodiment,

[0070] For pulse P[1], "+I2" is set as the A-phase current target value Ita, and "0" is set as the B-phase current target value Itb.

[0071] For pulse P[2], "+I1" is set as the A-phase current target value Ita, and "+I1" is set as the B-phase current target value Itb.

[0072] For pulse P[3], "0" is set as the A-phase current target value Ita, and "+I2" is set as the B-phase current target value Itb.

[0073] For pulse P[4], "-I1" is set as the A-phase current target value Ita, and "+I1" is set as the B-phase current target value Itb.

[0074] For pulse P[5], "-I2" is set as the A-phase current target value Ita, and "0" is set as the B-phase current target value Itb.

[0075] For pulse P[6], set "-I1" as the A-phase current target value Ita, and set "-I1" as the B-phase current target value Itb.

[0076] For pulse P[7], set "0" as the A-phase current target value Ita, and set "-I2" as the B-phase current target value Itb.

[0077] For pulse P[8], "+I1" is set as the A-phase current target value Ita, and "-I1" is set as the B-phase current target value Itb.

[0078] “+I2” and “-I2” mean that the magnitude of the current is the same but the direction of the current is different.

[0079] “+I1” and “-I1” mean that the magnitude of the current is the same but the direction of the current is different.

[0080] “+I2” and “+I1” mean that the magnitudes of the currents are different but the directions of the currents are the same.

[0081] Pulses P[1] to P[8] are sequentially input to the stepping motor 66.

[0082] When pulses P are input to the stepping motor 66 in ascending order (in the order of P[1] to P[8]), the magnetic rotor 31 moves in the valve closing direction (in the order of Figure 3Specifically, when the CPU 121 supplies the A-phase current Ia controlled to be equal to the A-phase current target value Ita set for the pulse P to the A-phase coil 61c in the order of pulses P (in ascending order), and supplies the B-phase current Ib controlled to be equal to the B-phase current target value Itb set for the pulse P to the B-phase coil 62c in the order of pulses P (in ascending order), the magnetic rotor 31 rotates in the valve closing direction.

[0083] When pulses P are input to the stepping motor 66 in descending order (P[8] to P[1]), the magnetic rotor 31 moves in the valve opening direction (in Figure 3 Specifically, when the CPU 121 supplies the A-phase current Ia controlled to be equal to the A-phase current target value Ita set for the pulse P to the A-phase coil 61c in the order of pulses P (descending order), and supplies the B-phase current Ib controlled to be equal to the B-phase current target value Itb set for the pulse P to the B-phase coil 62c in the order of pulses P (descending order), the magnetic rotor 31 rotates in the valve opening direction.

[0084] In addition, the fact that the A-phase current Ia is equal to the A-phase current target value Ita indicates that the magnitude of the current and the direction of the current of the A-phase current Ia are the same as the magnitude of the current and the direction of the current of the A-phase current target value Ita. The fact that the B-phase current Ib is equal to the B-phase current target value Itb indicates that the magnitude of the current and the direction of the current of the B-phase current Ib are the same as the magnitude of the current and the direction of the current of the B-phase current target value Itb.

[0085] In this embodiment, the excitation mode of the stepping motor 66 is 1-2 phase excitation. The step angle of the stepping motor 66 is 3.75 degrees. When the magnetic rotor 31 is located at the reference position Rx, the movable stopper 32s contacts the fixed stopper 33s, and the rotation of the magnetic rotor 31 in the valve closing direction is restricted. The number of pulses (initialization number) required to rotate the magnetic rotor 31 from the reference position Rx to the fully open position Rz is 500.

[0086] When the magnet rotor 31 rotates, the permanent magnet 45 also rotates, and the signal of the magnetic sensor 115 changes. When the magnet rotor 31 does not rotate, the permanent magnet 45 also does not rotate, and the signal of the magnetic sensor 115 does not change. Therefore, the control device 100 can determine whether the magnet rotor 31 rotates based on the signal of the magnetic sensor 115.

[0087] Next, refer to Fig. 9 An example of the processing of the control device 100 is described with reference to the flowchart.

[0088] When the power is turned on, the control device 100 (specifically, the CPU 121 ) reads the current position of the magnet rotor 31 (the current valve opening of the electric valve 5 ) from the nonvolatile memory 122 , and waits for a command from the air conditioning control device 410 .

[0089] The control device 100 receives a command for specifying the valve opening of the electric valve 5 from the air conditioning control device 410 (S110). The command includes information related to the target valve opening of the electric valve 5. When the current valve opening is greater than the target valve opening (S120: Yes), the control device 100 inputs pulses P in ascending order (S130). When the current valve opening is less than the target valve opening (S120: No, S140: Yes), the control device 100 inputs pulses P in descending order (S150). When the current valve opening is the target valve opening (S120: No, S140: No), the control device 100 ends the present process and waits for the next command.

[0090] The control device 100 inputs a PWM signal to the H-bridge circuit 123A corresponding to the input of the pulse P[1] so that the A-phase current Ia supplied to the A-phase coil 61c becomes "+I2", and inputs a PWM signal to the H-bridge circuit 123B so that the B-phase current Ib supplied to the B-phase coil 62c becomes "0". The control device 100 stores the duty ratio of the PWM signal input to the H-bridge circuit 123A (the A-phase duty ratio Da[1]) in the working memory 124. The control device 100 stores the duty ratio of the PWM signal input to the H-bridge circuit 123B (the B-phase duty ratio Db[1]) in the working memory 124. In addition, the duty ratio stored in the working memory 124 is, for example, the average value of the duty ratio during the input period Tpls of the pulse P, or the duty ratio obtained after the PWM signal is stabilized (for example, when the fluctuation of the duty ratio is small in the second half of the input period Tpls of the pulse P).

[0091] The control device 100 inputs a PWM signal to the H-bridge circuit 123A corresponding to the input of the pulse P[2] so that the A-phase current Ia supplied to the A-phase coil 61c becomes "+I1", and inputs a PWM signal to the H-bridge circuit 123B so that the B-phase current Ib supplied to the B-phase coil 62c becomes "+I1". The control device 100 stores the duty ratio of the PWM signal input to the H-bridge circuit 123A (A-phase duty ratio Da[2]) in the operation memory 124. The control device 100 stores the duty ratio of the PWM signal input to the H-bridge circuit 123B (B-phase duty ratio Db[2]) in the operation memory 124.

[0092] The control device 100 inputs a PWM signal to the H-bridge circuit 123A corresponding to the input of the pulse P[3] so that the A-phase current Ia supplied to the A-phase coil 61c becomes "0", and inputs a PWM signal to the H-bridge circuit 123B so that the B-phase current Ib supplied to the B-phase coil 62c becomes "+I2". The control device 100 stores the duty ratio of the PWM signal input to the H-bridge circuit 123A (the A-phase duty ratio Da[3]) in the operation memory 124. The control device 100 stores the duty ratio of the PWM signal input to the H-bridge circuit 123B (the B-phase duty ratio Db[3]) in the operation memory 124.

[0093] The control device 100 inputs a PWM signal to the H-bridge circuit 123A corresponding to the input of the pulse P[4] so that the A-phase current Ia supplied to the A-phase coil 61c becomes "-I1", and inputs a PWM signal to the H-bridge circuit 123B so that the B-phase current Ib supplied to the B-phase coil 62c becomes "+I1". The control device 100 stores the duty ratio of the PWM signal input to the H-bridge circuit 123A (A-phase duty ratio Da[4]) in the operation memory 124. The control device 100 stores the duty ratio of the PWM signal input to the H-bridge circuit 123B (B-phase duty ratio Db[4]) in the operation memory 124.

[0094] The control device 100 inputs a PWM signal to the H-bridge circuit 123A in response to the input of the pulse P[5], so that the A-phase current Ia supplied to the A-phase coil 61c becomes "-I2", and inputs a PWM signal to the H-bridge circuit 123B, so that the B-phase current Ib supplied to the B-phase coil 62c becomes "0". The control device 100 stores the duty ratio of the PWM signal input to the H-bridge circuit 123A (the A-phase duty ratio Da[5]) in the operation memory 124. The control device 100 stores the duty ratio of the PWM signal input to the H-bridge circuit 123B (the B-phase duty ratio Db[5]) in the operation memory 124.

[0095] The control device 100 inputs a PWM signal to the H-bridge circuit 123A corresponding to the input of the pulse P[6] so that the A-phase current Ia supplied to the A-phase coil 61c becomes "-I1", and inputs a PWM signal to the H-bridge circuit 123B so that the B-phase current Ib supplied to the B-phase coil 62c becomes "-I1". The control device 100 stores the duty ratio of the PWM signal input to the H-bridge circuit 123A (A-phase duty ratio Da[6]) in the operation memory 124. The control device 100 stores the duty ratio of the PWM signal input to the H-bridge circuit 123B (B-phase duty ratio Db[6]) in the operation memory 124.

[0096] The control device 100 inputs a PWM signal to the H-bridge circuit 123A corresponding to the input of the pulse P[7] so that the A-phase current Ia supplied to the A-phase coil 61c becomes "0", and inputs a PWM signal to the H-bridge circuit 123B so that the B-phase current Ib supplied to the B-phase coil 62c becomes "-I2". The control device 100 stores the duty ratio of the PWM signal input to the H-bridge circuit 123A (the A-phase duty ratio Da[7]) in the operation memory 124. The control device 100 stores the duty ratio of the PWM signal input to the H-bridge circuit 123B (the B-phase duty ratio Db[7]) in the operation memory 124.

[0097] The control device 100 inputs a PWM signal to the H-bridge circuit 123A corresponding to the input of the pulse P[8] so that the A-phase current Ia supplied to the A-phase coil 61c becomes "+I1", and inputs a PWM signal to the H-bridge circuit 123B so that the B-phase current Ib supplied to the B-phase coil 62c becomes "-I1". The control device 100 stores the duty ratio of the PWM signal input to the H-bridge circuit 123A (A-phase duty ratio Da[8]) in the operation memory 124. The control device 100 stores the duty ratio of the PWM signal input to the H-bridge circuit 123B (B-phase duty ratio Db[8]) in the operation memory 124.

[0098] The control device 100 compares the A-phase duty ratio Da and the B-phase duty ratio Db (S160) in accordance with the input of the pulse P. When the control device 100 detects that there is no abnormality in the A-phase coil 61c and the B-phase coil 62c based on the comparison result (S170: No), the control device 100 returns to step S120. When the control device 100 detects that there is an abnormality in the A-phase coil 61c or the B-phase coil 62c based on the comparison result (S170: Yes), the control device 100 sends information indicating a fault in the electric valve 5 to the air conditioning control device 410 (S180), and ends this process.

[0099] Next, a method for comparing the A-phase duty ratio Da and the B-phase duty ratio Db and a method for detecting abnormality will be described.

[0100] When the pulses P are input in ascending order, the control device 100 compares the B-phase duty ratio Db[K] obtained corresponding to the input of the pulse P[K] and the A-phase duty ratio Da[J] obtained corresponding to the input of the first two pulses P[J] of the pulse P[K]. The A-phase current target value Ita set for the pulse P[J] and the B-phase current target value Itb set for the pulse P[K] have the same current magnitude and current direction.

[0101] Specifically,

[0102] When the control device 100 obtains the B-phase duty ratio Db[1] corresponding to the input of pulse P[1], it compares the B-phase duty ratio Db[1] with the A-phase duty ratio Da[7] obtained corresponding to the input of the two pulses P[7] before pulse P[1].

[0103] When the control device 100 obtains the B-phase duty ratio Db[2] corresponding to the input of pulse P[2], it compares the B-phase duty ratio Db[2] with the A-phase duty ratio Da[8] obtained corresponding to the input of the two pulses P[8] before pulse P[2].

[0104] When the control device 100 obtains the B-phase duty ratio Db[3] corresponding to the input of pulse P[3], it compares the B-phase duty ratio Db[3] with the A-phase duty ratio Da[1] obtained corresponding to the input of the two pulses P[1] before pulse P[3].

[0105] When the control device 100 obtains the B-phase duty ratio Db[4] corresponding to the input of pulse P[4], it compares the B-phase duty ratio Db[4] with the A-phase duty ratio Da[2] obtained corresponding to the input of the two pulses P[2] before pulse P[4].

[0106] When the control device 100 obtains the B-phase duty ratio Db[5] corresponding to the input of pulse P[5], it compares the B-phase duty ratio Db[5] with the A-phase duty ratio Da[3] obtained corresponding to the input of the two pulses P[3] before pulse P[5].

[0107] When the control device 100 obtains the B-phase duty ratio Db[6] corresponding to the input of pulse P[6], it compares the B-phase duty ratio Db[6] with the A-phase duty ratio Da[4] obtained corresponding to the input of the two pulses P[4] before pulse P[6].

[0108] When the control device 100 obtains the B-phase duty ratio Db[7] corresponding to the input of pulse P[7], it compares the B-phase duty ratio Db[7] with the A-phase duty ratio Da[5] obtained corresponding to the input of the two pulses P[5] before pulse P[7].

[0109] When the control device 100 obtains the B-phase duty ratio Db[8] corresponding to the input of pulse P[8], it compares the B-phase duty ratio Db[8] with the A-phase duty ratio Da[6] obtained corresponding to the input of the two pulses P[6] before pulse P[8].

[0110] Then, the control device 100 compares the A-phase duty ratio Da[J] and the B-phase duty ratio Db[K], and when the difference between them is less than a predetermined reference value, it is determined that the A-phase coil 61c and the B-phase coil 62c are not abnormal. The reference value is, for example, 3 to 20%. When the difference exceeds the predetermined reference value, the control device 100 determines that the A-phase coil 61c or the B-phase coil 62c is abnormal, that is, it is detected that the A-phase coil 61c or the B-phase coil 62c is abnormal.

[0111] When the pulses P are input in descending order, the control device 100 compares the A-phase duty ratio Da[K] obtained corresponding to the input of the pulse P[K] and the B-phase duty ratio Db[J] obtained corresponding to the input of the two pulses P[J] preceding the pulse P[K]. The A-phase current target value Ita set for the pulse P[K] and the B-phase current target value Itb set for the pulse P[J] have the same current magnitude and current direction.

[0112] Specifically,

[0113] When the control device 100 obtains the A-phase duty ratio Da[8] corresponding to the input of pulse P[8], it compares the A-phase duty ratio Da[8] with the B-phase duty ratio Db[2] obtained corresponding to the input of the two pulses P[2] before pulse P[8].

[0114] When the control device 100 obtains the A-phase duty ratio Da[7] corresponding to the input of pulse P[7], it compares the A-phase duty ratio Da[7] with the B-phase duty ratio Db[1] obtained corresponding to the input of the two pulses P[1] before pulse P[7].

[0115] When the control device 100 obtains the A-phase duty ratio Da[6] corresponding to the input of pulse P[6], it compares the A-phase duty ratio Da[6] with the B-phase duty ratio Db[8] obtained corresponding to the input of the two pulses P[8] before pulse P[6].

[0116] When the control device 100 obtains the A-phase duty ratio Da[5] corresponding to the input of pulse P[5], it compares the A-phase duty ratio Da[5] with the B-phase duty ratio Db[7] obtained corresponding to the input of the two pulses P[7] before pulse P[5].

[0117] When the control device 100 obtains the A-phase duty cycle Da[4] corresponding to the input of pulse P[4], it compares the A-phase duty cycle Da[4] with the B-phase duty cycle Db[6] obtained corresponding to the input of the two pulses P[6] before pulse P[4].

[0118] When the control device 100 obtains the A-phase duty ratio Da[3] corresponding to the input of pulse P[3], it compares the A-phase duty ratio Da[3] with the B-phase duty ratio Db[5] obtained corresponding to the input of the two pulses P[5] before pulse P[3].

[0119] When the control device 100 obtains the A-phase duty ratio Da[2] corresponding to the input of pulse P[2], it compares the A-phase duty ratio Da[2] with the B-phase duty ratio Db[4] obtained corresponding to the input of the two pulses P[4] before pulse P[2].

[0120] When the control device 100 obtains the A-phase duty ratio Da[1] corresponding to the input of pulse P[1], it compares the A-phase duty ratio Da[1] with the B-phase duty ratio Db[3] obtained corresponding to the input of pulses P[3] two before pulse P[1].

[0121] Then, the control device 100 compares the A-phase duty ratio Da[K] and the B-phase duty ratio Db[J], and when the difference between them is less than a predetermined reference value, it is determined that the A-phase coil 61c and the B-phase coil 62c are not abnormal. When the difference exceeds a predetermined reference value, the control device 100 determines that an abnormality has occurred in the A-phase coil 61c or the B-phase coil 62c, that is, it is detected that an abnormality has occurred in the A-phase coil 61c or the B-phase coil 62c.

[0122] In the above-mentioned comparison method, the control device 100 may compare the A-phase duty ratio Da and the B-phase duty ratio Db obtained in response to the input of the pulses P[2], P[4], P[6], and P[8] as follows. The A-phase current target value Ita and the B-phase current target value Itb set for the pulses P[2], P[4], P[6], and P[8] are at least the same in magnitude.

[0123] When the control device 100 obtains the A-phase duty ratio Da[2] and the B-phase duty ratio Db[2] in response to the input of the pulse P[2], the control device 100 compares the A-phase duty ratio Da[2] and the B-phase duty ratio Db[2].

[0124] When the control device 100 obtains the A-phase duty ratio Da[4] and the B-phase duty ratio Db[4] in response to the input of the pulse P[4], the control device 100 compares the A-phase duty ratio Da[4] and the B-phase duty ratio Db[4].

[0125] When the control device 100 obtains the A-phase duty ratio Da[6] and the B-phase duty ratio Db[6] in response to the input of the pulse P[6], the control device 100 compares the A-phase duty ratio Da[6] and the B-phase duty ratio Db[6].

[0126] When the control device 100 obtains the A-phase duty ratio Da[8] and the B-phase duty ratio Db[8] in response to the input of the pulse P[8], the control device 100 compares the A-phase duty ratio Da[8] and the B-phase duty ratio Db[8].

[0127] The electric valve device 1 of this embodiment has an electric valve 5 and a control device 100. The electric valve 5 has: a valve body 10 having a valve chamber 14, a valve core 40 arranged in the valve chamber 14, and a stepping motor 66 for moving the valve core 40. The stepping motor 66 has a magnetic rotor 31 and a stator 60 (A-phase stator 61, B-phase stator 62). The control device 100 controls the electric valve 5. The control device 100 controls the A-phase current Ia supplied to the A-phase coil 61c of the A-phase stator 61 and the B-phase current Ib supplied to the B-phase coil 62c of the B-phase stator 62 by PWM. The control device 100 detects that an abnormality has occurred in the A-phase coil 61c or the B-phase coil 62c based on the comparison of the A-phase duty ratio Da of the A-phase current Ia and the B-phase duty ratio Db of the B-phase current Ib.

[0128] For example, when the driving voltage and ambient temperature of the stepping motor 66 change, the A-phase duty cycle Da and the B-phase duty cycle Db change together. In this case, the relationship between the A-phase duty cycle Da and the B-phase duty cycle Db does not change. Moreover, when an abnormality occurs in the A-phase coil 61c or the B-phase coil 62c, the impedance of the A-phase coil 61c or the impedance of the B-phase coil 62c changes, and the A-phase duty cycle Da or the B-phase duty cycle Db changes. In this case, the relationship between the A-phase duty cycle Da and the B-phase duty cycle Db changes. Therefore, when the control device 100 compares the A-phase duty cycle Da and the B-phase duty cycle Db and the relationship changes, it can be determined that an abnormality has occurred in the A-phase coil 61c or the B-phase coil 62c. The relationship is, for example, the difference between the A-phase duty cycle Da and the B-phase duty cycle Db. Therefore, the control device 100 suppresses erroneous detection of an abnormality of the coil due to fluctuations in the drive voltage of the stepping motor 66 or the ambient temperature, and can more accurately detect a failure of the stepping motor 66 .

[0129] In addition, the control device 100 compares: the A-phase duty ratio Da of the A-phase current Ia controlled to be equal to the A-phase current target value Ita and the B-phase duty ratio Db of the B-phase current Ib controlled to be equal to the B-phase current target value Itb, and the B-phase current target value Itb is the same as the A-phase current target value Ita. In this way, when there is no abnormality in the A-phase coil 61c and the B-phase coil 62c, the A-phase duty ratio Da is the same as the B-phase duty ratio Db, and when an abnormality occurs in the A-phase coil 61c or the B-phase coil 62c, the A-phase duty ratio Da is different from the B-phase duty ratio Db. Therefore, the control device 100 can compare the A-phase duty ratio Da with the B-phase duty ratio Db through simple processing.

[0130] In addition, the control device 10 may also compare: the A-phase duty ratio Da of the A-phase current Ia controlled to be equal to the A-phase current target value Ita and the B-phase duty ratio Db of the B-phase current Ib controlled to be equal to the B-phase current target value Itb, and the B-phase current target value Itb is different from the A-phase current target value Ita. In this case, the control device 100 compares the A-phase duty ratio Da and the B-phase duty ratio Db in consideration of the difference (ratio) between the A-phase current target value Ita and the B-phase current target value Itb. For example, when the ratio (Ita / Itb) of the A-phase current target value Ita and the B-phase current target value Itb is 1 / 2 and there is no abnormality in the A-phase coil 61c and the B-phase coil 62c, the ratio (Da / Db) of the A-phase duty ratio Da and the B-phase duty ratio Db also becomes 1 / 2. Therefore, the control device 100 compares the value (Da×2) of the 2 times A-phase duty ratio Da with the B-phase duty ratio Db.

[0131] In addition, the control device 100 compares the A-phase duty ratio Da and the B-phase duty ratio Db when the A-phase current Ia and the B-phase current Ib are controlled to rotate the magnetic rotor 31. In this way, the control device 100 can detect an abnormality of the A-phase coil 61c or the B-phase coil 62c in the normal process (processing for making the valve opening of the electric valve 5 become a specified target valve opening).

[0132] In addition, an A-phase current target value Ita and a B-phase current target value Itb are set for the plurality of pulses P, respectively. When an A-phase current Ia equal to the A-phase current target value Ita set for the plurality of pulses P is supplied to the A-phase coil 61c in the order of the plurality of pulses P, and a B-phase current Ib equal to the B-phase current target value Itb set for the plurality of pulses P is supplied to the B-phase coil 62c in the order of the plurality of pulses P, the magnetic rotor 31 rotates. The control device 100 compares: the A-phase duty ratio Da of the A-phase current Ia controlled to be equal to the A-phase current target value Ita set for one pulse P among the plurality of pulses P, and the B-phase duty ratio Db of the B-phase current Ib controlled to be equal to the B-phase current target value Itb set for the other pulses P among the plurality of pulses P, the B-phase current target value Itb being the same size as the A-phase current target value Ita set for the one pulse P. In this way, the control device 100 can compare the A-phase duty ratio Da with the B-phase duty ratio Db by simple processing. Furthermore, the control device 100 can detect abnormality of the A-phase coil 61 c or the B-phase coil 62 c during normal processing.

[0133] The control device 100 of this embodiment has a structure for detecting an abnormality of the A-phase coil 61c or the B-phase coil 62c in normal processing, but the present invention is not limited to such a structure. The control device 100 may also have a structure for detecting an abnormality of the A-phase coil 61c or the B-phase coil 62c in the initialization processing just after the power is turned on. For example, the control device 100 inputs a PWM signal to the H-bridge circuit 123A in the initialization processing so that the A-phase current Ia supplied to the A-phase coil 61c becomes "+I2", and inputs a PWM signal to the H-bridge circuit 123B so that the B-phase current Ib supplied to the B-phase coil 62c becomes "+I2". The control device 100 compares the duty cycle of the PWM signal input to the H-bridge circuit 123A (A-phase duty cycle Da) with the duty cycle of the PWM signal input to the H-bridge circuit 123B (B-phase duty cycle Db). Then, the control device 100 detects that an abnormality has occurred in the A-phase coil 61c or the B-phase coil 62c based on the comparison result.

[0134] The control device 100 of this embodiment performs current control on the electric valve 5 (stepping motor 66), but it is also possible to perform voltage control on the electric valve 5. In the voltage control structure, the control device 100 controls the A-phase voltage supplied to the A-phase coil 61c of the A-phase stator 61 and the B-phase voltage supplied to the B-phase coil 62c of the B-phase stator 62 by PWM. The control device 100 detects that an abnormality has occurred in the A-phase coil 61c or the B-phase coil 62c based on the comparison of the duty ratio of the A-phase voltage (A-phase voltage duty ratio) and the duty ratio of the B-phase voltage (B-phase voltage duty ratio).

[0135] In addition, in the voltage control structure, the control device 100 can also compare the A-phase voltage duty cycle of the A-phase voltage controlled to be equal to the A-phase voltage target value with the B-phase voltage duty cycle of the B-phase voltage controlled to be equal to the B-phase voltage target value, and the B-phase voltage target value is the same size as the A-phase voltage target value.

[0136] In the voltage control configuration, the control device 100 may compare the A-phase voltage duty ratio and the B-phase voltage duty ratio when the A-phase voltage and the B-phase voltage are controlled to rotate the magnet rotor 31 .

[0137] In addition, in the voltage control structure, the following structure can also be adopted. The plurality of pulses P have a sequence, and the A-phase voltage target value and the B-phase voltage target value are set for the plurality of pulses P, respectively. When the A-phase voltage equal to the A-phase voltage target value set for the plurality of pulses P is supplied to the A-phase coil 61c in the sequence of the plurality of pulses P, and the B-phase voltage equal to the B-phase voltage target value set for the plurality of pulses P is supplied to the B-phase coil 62c in the sequence of the plurality of pulses P, the magnetic rotor 31 rotates. Then, the control device 100 compares: the A-phase voltage duty ratio of the A-phase voltage controlled to be equal to the A-phase voltage target value set for one of the plurality of pulses P, and the B-phase voltage duty ratio of the B-phase voltage controlled to be equal to the B-phase voltage target value set for the other pulses P among the plurality of pulses P, the B-phase voltage target value being the same size as the A-phase voltage target value set for the above-mentioned one pulse P.

[0138] In addition, the A-phase voltage being equal to the A-phase voltage target value indicates that the magnitude of the voltage of the A-phase voltage and the direction of the voltage are the same as the magnitude of the voltage of the A-phase voltage target value and the direction of the voltage. The B-phase voltage being equal to the B-phase voltage target value indicates that the magnitude of the voltage of the B-phase voltage and the direction of the voltage are the same as the magnitude of the voltage of the B-phase voltage target value and the direction of the voltage.

[0139] The control device 100 that controls the voltage of the electric valve 5 has the same (including substantially the same) effects as those of the above-described control device 100 .

[0140] In the present embodiment, the control device 100 controls the electric valve 5, but the air conditioning control device 410 may directly control the electric valve 5. In this case, the air conditioning control device 410 is an electric valve control device.

[0141] In this specification, the terms "cylindrical" and "column" indicating the shape of a component are also used for components substantially having the shape of these terms. For example, "a cylindrical component" includes a cylindrical component and a substantially cylindrical component.

[0142] The embodiments of the present invention are described above, but the present invention is not limited to these examples. A person skilled in the art may appropriately add, delete, design and modify the structure of the constituent elements of the above embodiments, or appropriately combine the features of the embodiments, and these are included in the scope of the present invention as long as they do not violate the gist of the present invention.

[0143] Explanation of symbols

[0144] 1…Electric valve device, 5…Electric valve, 10…Valve body, 11…Main body member, 11a…Mounting hole, 11b…Upper surface, 12…Support member, 12a…Engagement hole, 13…Connecting member, 14…Valve chamber, 15…Flow path, 16…Flow path, 17…Valve port, 18…Valve seat, 20…Can body, 30…Drive mechanism, 31…Magnetic rotor, 32…Valve shaft holder, 32c…Internal thread, 32s…Movable stopper, 33…Guide bushing, 33a…First cylindrical portion, 33b…Second cylindrical portion, 33c…External thread groove, 33e...through hole, 33s...fixed stopper, 34...valve shaft, 34a...first portion, 34b...second portion, 34d...step portion, 35...support ring, 36...thrust nut, 37...valve closing spring, 38...stop mechanism, 40...valve core, 45...permanent magnet, 46...guide member, 47...support spring, 48...sliding member, 50...stator unit, 60...stator, 61...A-phase stator, 61a...pole tooth, 61b...pole tooth, 61c...A-phase coil, 62...B-phase stator, 62a...pole tooth, 62b…pole teeth, 62c…B-phase coil, 65…terminal, 66…stepping motor, 70…housing, 83…connector, 100…electric valve control device, 110…control board, 111…wire, 115…magnetic sensor, 120…microcomputer, 121…CPU, 122…nonvolatile memory, 123…motor driver, 123A…H-bridge circuit, 123B…H-bridge circuit, 124…operating memory, 125…communication module, 126…temperature sensor, 127A…current detection resistor , 127B…current detection resistor, 128A…analog-to-digital converter, 128B…analog-to-digital converter, 400…air conditioning system, 401…compressor, 402…condenser, 403…evaporator, 405…piping, 410…air conditioning control device, 420…communication bus, Ia…A phase current, Ib…B phase current, Ita…A phase current target value, Itb…B phase current target value, Da…A phase duty cycle, Db…B phase duty cycle, L…axis line, Rc…valve closing position, Rx…reference position, Rz…fully open position.

Claims

1. An electric valve control device for controlling an electric valve, characterized in that: The electric valve includes: a valve body having a valve chamber, a valve element arranged in the valve chamber, and a stepping motor for moving the valve element. The stepper motor has a magnetic rotor, an A-phase stator and a B-phase stator. The electric valve control device controls the A-phase current supplied to the A-phase coil of the A-phase stator and the B-phase current supplied to the B-phase coil of the B-phase stator by PWM. The electric valve control device detects an abnormality in the A-phase coil or the B-phase coil based on a comparison of the duty cycle of the A-phase current and the duty cycle of the B-phase current. Hereinafter, the duty cycle of the A-phase current is referred to as the A-phase duty cycle, and the duty cycle of the B-phase current is referred to as the B-phase duty cycle.

2. The electric valve control device according to claim 1, characterized in that: The electric valve control device compares: the A-phase duty cycle of the A-phase current controlled to be equal to the A-phase current target value and the B-phase duty cycle of the B-phase current controlled to be equal to the B-phase current target value, and the B-phase current target value is the same as the A-phase current.

3. The electric valve control device according to claim 1 or 2, characterized in that: The electric valve control device compares the A-phase duty ratio and the B-phase duty ratio when the A-phase current and the B-phase current are controlled to rotate the magnet rotor.

4. The electric valve control device according to claim 1, characterized in that: The plurality of pulses have a sequence, and a target current value of the A phase and a target current value of the B phase are set for the plurality of pulses respectively. When the A-phase current equal to the A-phase current target values ​​respectively set for the plurality of pulses is supplied to the A-phase coil in the sequence, and the B-phase current equal to the B-phase current target values ​​respectively set for the plurality of pulses is supplied to the B-phase coil in the sequence, the magnetic rotor rotates, The electric valve control device compares: the A-phase duty cycle of the A-phase current controlled to be equal to the A-phase current target value set for one of the multiple pulses and the B-phase duty cycle of the B-phase current controlled to be equal to the B-phase current target value set for the other pulses among the multiple pulses, and the B-phase current target value is the same size as the A-phase current target value set for the one pulse.

5. An electric valve control device for controlling an electric valve, characterized in that: The electric valve includes: a valve body having a valve chamber, a valve element arranged in the valve chamber, and a stepping motor for moving the valve element. The stepper motor has a magnetic rotor, an A-phase stator and a B-phase stator. The electric valve control device controls the A-phase voltage supplied to the A-phase coil of the A-phase stator and the B-phase voltage supplied to the B-phase coil of the B-phase stator by PWM. The electric valve control device detects that an abnormality has occurred in the A-phase coil or the B-phase coil based on a comparison between a duty ratio of the A-phase voltage and a duty ratio of the B-phase voltage.

6. An electric valve device, characterized in that: A motor-driven valve control device as claimed in claim 1 or 5 and the motor-driven valve.

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