Motor-operated valve control device and motor-operated valve device

Abstract

[Problem] To provide a motorized valve control device and a motorized valve device that can more accurately detect a malfunction of a stepping motor of a motorized valve. [Solution] A motorized valve device (1) comprises a motorized valve (5) and a motorized valve control device (100). The motorized valve (5) has a stepping motor (66), and the stepping motor (66) has a magnet rotor (31), an A-phase stator (61), and a B-phase stator (62). The motorized valve control device (100) controls an A-phase current (Ia) which is supplied to an A-phase coil (61c) of the A-phase stator (61), and a B-phase current (Ib) which is supplied to a B-phase coil (62c) of the B-phase stator (62), by a PWM method. The motorized valve control device (100) detects occurrence of an abnormality in the A-phase coil (61c) or the B-phase coil (62c), on the basis of a comparison between an A-phase duty ratio (Da) related to the A-phase current (Ia) and a B-phase duty ratio (Db) related to the B-phase current (Ib).

Description

[Technical field]

[0001] The present invention relates to a motor-operated valve control device, and a motor-operated valve device having a motor-operated valve and a motor-operated valve control device. [Background technology]

[0002] Patent Document 1 discloses an example of a conventional motor-operated valve. The motor-operated valve has a case, a magnet rotor, and a stator. The magnet rotor is disposed inside the case. The stator is disposed outside the case. The magnet rotor and the stator constitute a stepping motor.

[0003] Motor-operated valves are incorporated in, for example, air conditioning systems and are used to control the flow rate of refrigerant. The coil of the stator of the motor-operated valve can sometimes become abnormal. Abnormalities include short circuits, rare short circuits, and open circuits. If an abnormality occurs in the coil, it may cause the motor-operated valve to malfunction. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2018-179133 A [Patent Document 2] JP 2020-178500 A Summary of the Invention [Problem to be solved by the invention]

[0005] Patent Document 2 discloses an example of a fault diagnosis device capable of detecting a short circuit in the coil of a stepping motor. The fault diagnosis device detects a short circuit based on the magnitude of the current flowing through the coil. However, the magnitude of the current flowing through the coil may change due to fluctuations in the driving voltage of the stepping motor and the ambient temperature. As a result, the fault diagnosis device may erroneously detect a fault in the stepping motor.

[0006] SUMMARY OF THE PRESENT DISCLOSURE In view of the above, an object of the present invention is to provide an electric valve control device and an electric valve device that are capable of more accurately detecting a failure in a stepping motor of a motor-operated valve. [Means for solving the problem]

[0007] In order to achieve the above object, an electric valve control device according to one embodiment of the present invention is an electric valve control device that controls an electric valve, the electric valve having 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 stepping motor having a magnet rotor, an A-phase stator, and a B-phase stator, the electric valve control device controls an A-phase current supplied to an A-phase coil of the A-phase stator and a B-phase current supplied to a B-phase coil of the B-phase stator by a PWM method, and detects an abnormality in the A-phase coil or the B-phase coil based on a comparison between a duty ratio associated with the A-phase current (hereinafter referred to as the "A-phase duty ratio") and a duty ratio associated with the B-phase current (hereinafter referred to as the "B-phase duty ratio").

[0008] In the present invention, it is preferable that the motor-operated valve control device compares the A-phase duty ratio associated with the A-phase current controlled to be equal to an A-phase current target value with the B-phase duty ratio associated with the B-phase current controlled to be equal to a B-phase current target value having the same magnitude as the A-phase current target value.

[0009] In the present invention, it is preferable that the motor-operated valve control device compares the A-phase duty ratio with the B-phase duty ratio when controlling the A-phase current and the B-phase current so as to rotate the magnet rotor.

[0010] In the present invention, it is preferable that a plurality of pulses have an order, an A-phase current target value and a B-phase current target value are set for each of the plurality of pulses, and when the A-phase current equal to the A-phase current target value set for each of the plurality of pulses is supplied to the A-phase coil in the order and the B-phase current equal to the B-phase current target value set for each of the plurality of pulses is supplied to the B-phase coil in the order, the magnet rotor rotates, and the motor-operated valve control device compares the A-phase duty ratio associated with the A-phase current controlled to be equal to the A-phase current target value set for one pulse of the plurality of pulses with the B-phase duty ratio associated with the B-phase current controlled to be equal to the B-phase current target value set for another pulse of the plurality of pulses and having the same magnitude as the A-phase current target value set for the one pulse.

[0011] In order to achieve the above object, an electric valve control device according to another embodiment of the present invention is an electric valve control device that controls an electric valve, the electric valve having a valve body having a valve chamber, a valve body arranged in the valve chamber, and a stepping motor for moving the valve body, the stepping motor having a magnet rotor, an A-phase stator, and a B-phase stator, the electric valve control device controls an A-phase voltage supplied to an A-phase coil of the A-phase stator and a B-phase voltage supplied to a B-phase coil of the B-phase stator by a PWM method, and detects the occurrence of an abnormality in the A-phase coil or the B-phase coil based on a comparison between a duty ratio associated with the A-phase voltage and a duty ratio associated with the B-phase voltage.

[0012] In order to achieve the above object, a motor-operated valve device according to another aspect of the present invention includes the motor-operated valve and the motor-operated valve control device. Effect of the Invention

[0013] The motor-operated valve control device uses the PWM method to control 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.The motor-operated valve control device detects the occurrence of an abnormality in the A-phase coil or B-phase coil based on a comparison between the duty ratio related to the A-phase current (A-phase duty ratio) and the duty ratio related to the B-phase current (B-phase duty ratio).

[0014] In a configuration in which the current supplied to the coil is controlled by the PWM method, when the resistance value and inductance (hereinafter referred to as "impedance") of the coil change, the duty ratio of the PWM signal also changes. For example, when the driving voltage or ambient temperature of the stepping motor changes, both the A-phase duty ratio and the B-phase duty ratio change. In this case, the relationship between the A-phase duty ratio and the B-phase duty ratio does not change. 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 A-phase duty ratio or the B-phase duty ratio changes. In this case, the relationship between the A-phase duty ratio and the B-phase duty ratio changes. Therefore, the motor-operated valve control device can determine that an abnormality has occurred in the A-phase coil or the B-phase coil when there is a change in the relationship by comparing the A-phase duty ratio and the B-phase duty ratio. Therefore, it is possible to suppress erroneous detection of coil abnormalities due to fluctuations in the driving voltage or ambient temperature of the stepping motor, and more accurately detect failures in the stepping motor. [Brief description of the drawings]

[0015] [Figure 1] 1 is a block diagram of an air conditioning system having a motor-operated valve device according to an embodiment of the present invention. [Diagram 2] FIG. [Diagram 3] 3A and 3B are diagrams illustrating a magnet rotor and a stator of the motor-operated valve device. [Figure 4] FIG. 2 is a diagram illustrating a microcomputer, a stepping motor, and a magnetic sensor of the motor-operated valve device. [Diagram 5]FIG. 2 is a diagram illustrating a CPU and a motor driver of a microcomputer. [Figure 6] FIG. 4 is a diagram illustrating an example of a waveform of a PWM signal. [Figure 7] 10 is a diagram showing an example of a correspondence relationship between a plurality of pulses and an A-phase current target value and a B-phase current target value. FIG. [Figure 8] 4 is a diagram showing an example of a current waveform of an A-phase current flowing through an A-phase coil and a current waveform of a B-phase current flowing through a B-phase coil. FIG. [Figure 9] 4 is a flowchart showing an example of a process executed by the motor-operated valve control device. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] Hereinafter, a motor-operated valve device according to one embodiment of the present invention will be described with reference to FIGS.

[0017] FIG. 1 is a block diagram of an air conditioning system having an electric valve device according to an embodiment of the present invention. FIG. 2 is a cross-sectional view of the electric valve device. FIG. 3 is a diagram for explaining a magnet rotor and a stator of the electric valve device. In FIG. 3, the magnetic poles of the magnet rotor and the pole teeth of the stator are shown typically. In FIG. 3, the radially outer side corresponds to the upper side, and the radially inner side corresponds to the lower side. FIG. 4 is a diagram for explaining a microcomputer, a stepping motor, and a magnetic sensor of the electric valve device. FIG. 4 shows a schematic diagram of the connection relationship between the microcomputer, the stepping motor, and the magnetic sensor. FIG. 5 shows a diagram for explaining a CPU and a motor driver of the microcomputer. FIG. 5 shows a schematic diagram of the connection relationship between the CPU and the motor driver. FIG. 6 is a diagram showing an example of a waveform (voltage waveform) of a PWM signal. FIG. 7 is a diagram showing an example of the correspondence relationship between a plurality of pulses and an A-phase current target value and a B-phase current target value. FIG. 8 is a diagram showing an example of the current waveform of the A-phase current flowing through the A-phase coil and the current waveform of the B-phase current flowing through the B-phase coil. FIG. 9 is a flowchart showing an example of a process executed by the electric valve control device.

[0018] The motor-operated valve device 1 according to this embodiment includes a motor-operated valve 5 and a motor-operated valve control device (hereinafter simply referred to as a "control device 100").

[0019] The motor-operated valve device 1 is incorporated, for example, in an air conditioning system 400 shown in Fig. 1. The air conditioning system 400 has a compressor 401, a condenser 402, the motor-operated valve device 1 (motor-operated valve 5), and an evaporator 403, which are connected in this order via piping 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 communicatively connected to the motor-operated valve device 1 (control device 100) via a communication bus 420. The air conditioning control device 410 uses the motor-operated valve device 1 to control the flow rate of refrigerant flowing through the piping 405.

[0020] As shown in FIG. 2, the motor-operated 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.

[0021] The valve body 10 is made of a metal such as an aluminum alloy. The valve body 10 includes a body member 11, a support member 12, and a connection member 13. The body member 11 has a rectangular parallelepiped shape. The body member 11 has a mounting hole 11a. The mounting hole 11a is disposed on the upper surface 11b of the body member 11. The support member 12 has a cylindrical shape. The lower part of the support member 12 is disposed in the mounting hole 11a. The support member 12 is attached to the body member 11 by a screw structure. The upper part of the support member 12 protrudes from the upper surface 11b of the body member 11. The body member 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 member 13 has a circular plate shape. The upper portion of the supporting member 12 is joined to the inner peripheral edge of the connecting member 13.

[0022] The can 20 is made of a metal such as stainless steel. The can 20 has a cylindrical shape. The upper end of the can 20 is closed and the lower end is open. The lower end of the can 20 is joined to the outer periphery of the connection member 13.

[0023] The drive mechanism 30 moves the valve body 40 in the vertical direction (the direction of the axis L). The drive mechanism 30 has a magnet rotor 31, a valve stem holder 32, a guide bush 33, and a valve stem .

[0024] The magnet rotor 31 has a cylindrical shape. The outer diameter of the magnet rotor 31 is slightly smaller than the inner diameter of the can 20. A small gap is formed between the inner peripheral surface of the can 20 and the outer peripheral surface of the magnet rotor 31. The magnet rotor 31 has multiple magnetic poles (multiple N poles and multiple S poles). The multiple N poles and multiple S poles are arranged on the outer peripheral surface of the magnet rotor 31. The multiple N poles and multiple S poles extend in the vertical direction. The multiple N poles and multiple S poles are arranged alternately at equal intervals in the circumferential direction. In this embodiment, the magnet rotor 31 has 12 N poles and 12 S poles. The interval (angle) between adjacent N poles and S poles is 15 degrees.

[0025] The stem holder 32 has a cylindrical shape. The upper end of the stem holder 32 is closed and the lower end is open. A support ring 35 is fixed to the upper part of the stem holder 32. The support ring 35 connects the magnet rotor 31 and the stem holder 32. The stem holder 32 rotates together with the magnet rotor 31. An internal thread 32c is provided on the inner peripheral surface of the stem holder 32.

[0026] The guide bush 33 has a first cylindrical portion 33a and a second cylindrical portion 33b integrally therewith. 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 circumferential surface of the second cylindrical portion 33b. The external thread 33c is screwed into the internal thread 32c of the valve shaft holder 32. The first cylindrical portion 33a is press-fitted into a fitting hole 12a provided in the support member 12 of the valve body 10. The guide bush 33 is coupled to the valve body 10.

[0027] A movable stopper 32s is fixed to the valve stem holder 32. A fixed stopper 33s is fixed to the first cylindrical portion 33a of the guide bush 33. When the movable stopper 32s and the fixed stopper 33s come into contact with each other, the rotation of the valve stem holder 32 (i.e., the magnet 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 magnet rotor 31 in the valve closing direction.

[0028] The valve shaft 34 has a first portion 34a and a second portion 34b integrally. The first portion 34a and the second portion 34b have a cylindrical shape. The diameter of the second portion 34b is smaller than the diameter 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 penetrates the valve shaft holder 32. A push nut 36 for preventing the valve shaft 34 from coming off is attached to the second portion 34b. The valve shaft 34 is disposed inside the guide bush 33 and inside the support member 12. The lower end of the first portion 34a is disposed in the valve chamber 14. The valve shaft 34 has a step portion 34d. The step portion 34d is disposed at the connection portion between the first portion 34a and the second portion 34b. A valve-closing spring 37 is disposed 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 presses the valve shaft 34 downward.

[0029] The valve element 40 is disposed in the valve chamber 14. The valve element 40 faces the valve orifice 17 in the vertical direction. The valve element 40 opens and closes the valve orifice 17. The valve element 40 is connected to the lower end of the valve shaft 34. The valve shaft 34 and the valve element 40 are integrally formed, for example, by cutting a cylindrical workpiece.

[0030] The permanent magnet 45 is disposed above the magnet rotor 31 inside the can 20. The permanent magnet 45 has a circular plate shape. The permanent magnet 45 has one N pole and one S pole. The N pole and the S pole are disposed so as to face each other in the radial direction. The permanent magnet 45 is supported by a guide member 46 attached to the support ring 35. The guide member 46 supports the permanent magnet 45 so as to be movable in the vertical direction relative to the guide member 46. The rotation of the magnet rotor 31 is transmitted to the permanent magnet 45 via the guide member 46. The permanent magnet 45 is rotated together with the magnet rotor 31. A support spring 47 is disposed 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 fitted inside 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 having a relatively small coefficient of friction.

[0031] The permanent magnet 45 is pushed upward by the support spring 47, and the sliding member 48 is constantly in contact with the inner surface of the can 20. Even if the magnet rotor 31 moves up and down due to the feed screw action of the female thread 32c of the valve stem holder 32 and the male thread 33c of the guide bush 33, the vertical position of the permanent magnet 45 remains constant.

[0032] The stator unit 50 includes a stator 60 and a housing 70 .

[0033] The stator 60 has a cylindrical shape. The stator 60 includes an A-phase stator 61 and a B-phase stator 62.

[0034] The A-phase stator 61 has a plurality of claw-pole type pole teeth 61a, 61b on the inner circumference. The tip of the pole tooth 61a faces downward, and the tip of the pole tooth 61b faces upward. The pole teeth 61a and the pole teeth 61b are alternately arranged at equal intervals in the circumferential direction. In this embodiment, the A-phase stator 61 has 12 pole teeth 61a and 12 pole teeth 61b. The angle between the pole teeth 61a and the pole teeth 61b adjacent to each other 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 have polarities different from each other.

[0035] The B-phase stator 62 has a plurality of claw-pole-shaped pole teeth 62a, 62b on the inner circumference. The tip of the pole tooth 62a faces downward, and the tip of the pole tooth 62b faces upward. The pole teeth 62a and the pole teeth 62b are alternately arranged at equal intervals in the circumferential direction. In this embodiment, the B-phase stator 62 has 12 pole teeth 62a and 12 pole teeth 62b. The angle between the pole teeth 62a and the pole teeth 62b adjacent to each other 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 have polarities different from each other. The B-phase stator 62 has the same configuration as the A-phase stator 61 (including substantially the same configuration). The design impedance (resistance value and inductance) of the B-phase coil 62c is the same as the design 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.

[0036] The A-phase stator 61 and the B-phase stator 62 are arranged coaxially. The A-phase stator 61 and the B-phase stator 62 are in contact with each other. When viewed from the axis L direction, the angle between the pole tooth 61a of the A-phase stator 61 and the pole tooth 62a of the B-phase stator 62 that are 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.

[0037] The housing 70 is made of synthetic resin. The housing 70 has a rectangular box shape. The housing 70 accommodates the stator 60. The can 20 is disposed inside the stator 60 and inside the housing 70. The stator 60 and the magnet rotor 31 constitute a stepping motor 66 for driving the valve body 40. The housing 70 is provided with a connector 83 that protrudes in the lateral direction (direction perpendicular to the axis L).

[0038] In the electric valve 5, the main body member 11 (valve port 17, valve seat 18), support member 12, connecting member 13, can 20, magnet rotor 31, valve shaft 34, valve body 40, permanent magnet 45, and stator 60 (A-phase stator 61, B-phase stator 62) each have a central axis that coincides with the axis L.

[0039] In the motor-operated valve 5, when the magnet rotor 31 rotates in the valve closing direction, the magnet rotor 31 and the valve shaft holder 32 move downward due to the feed screw action of the female screw 32c of the valve shaft holder 32 and the male screw 33c of the guide bush 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 body 40 move downward and the valve body 40 contacts the valve seat 18. The position of the magnet rotor 31 at this time is the valve closing position Rc. When the magnet rotor 31 rotates further in the valve closing direction from this state, the valve closing spring 37 is compressed and the magnet rotor 31 and the valve shaft holder 32 move further downward. The valve body 40 does not move downward. Then, when the movable stopper 32s contacts the fixed stopper 33s, the rotation of the magnet rotor 31 in the valve closing direction is restricted. The position of the magnet rotor 31 at this time is the reference position Rx.

[0040] In the motor-operated valve 5, when the magnet rotor 31 rotates in the valve opening direction, the feed screw action between the female thread 32c of the valve stem holder 32 and the male thread 33c of the guide bush 33 causes the magnet rotor 31 and the valve stem holder 32 to move upward. The valve stem holder 32 pushes the push nut 36 upward. The valve stem 34 and valve body 40 move upward, and the valve body 40 moves away from the valve seat 18. When the magnet rotor 31 rotates further in the valve opening direction, the magnet rotor 31 reaches the fully open position Rz. When the magnet rotor 31 is in the fully open position Rz, the valve body 40 is furthest from the valve orifice 17.

[0041] The control device 100 includes a control board 110 , a magnetic sensor 115 , and a microcomputer 120 .

[0042] The control board 110 is a printed circuit board on which electronic components are mounted. The control board 110 is accommodated in the housing 70. The control board 110 is arranged above the can 20 along the horizontal direction. A plurality of terminals 65 of the stator 60 are connected to the control board 110 via electric wires 111. A magnetic sensor 115 and a microcomputer 120 are mounted on the control board 110.

[0043] The magnetic sensor 115 is aligned vertically with the permanent magnet 45 via the can 20. In other words, the magnetic sensor 115 faces the permanent magnet 45 in the vertical direction via the can 20. The magnetic sensor 115 detects the magnetic field generated by the permanent magnet 45. The magnetic sensor 115 outputs a signal (analog signal) according to the rotation angle of the magnetic field. In other words, the magnetic sensor 115 is a rotation angle sensor that outputs a signal according to the rotation angle of the permanent magnet 45 (i.e., the magnet rotor 31). Note that one or more Hall ICs that output a binary signal may be used as the magnetic sensor 115.

[0044] 1 and 4, the microcomputer 120 is a microcomputer for an embedded device that integrates, for example, a central processing unit CPU 121, a non-volatile memory 122, a motor driver 123, a working memory 124, a communication module 125, a temperature sensor 126, and the like in one package. The microcomputer 120 controls the motor-operated valve 5. The non-volatile memory, the working memory, the communication module, the motor driver, and the temperature sensor may be separate electronic components externally connected to the microcomputer 120.

[0045] The CPU 121 executes a program stored in the non-volatile memory 122 and functions as various functional units. The non-volatile memory 122 stores the current position of the magnet rotor 31 immediately before the power supply to the CPU 121 is cut off. When the power supply to the CPU 121 is turned on, the CPU 121 reads the current position of the magnet rotor 31 from the non-volatile memory 122. The work memory 124 stores variables used in the functional units. The communication module 125 is connected to the air conditioner control device 410 via the communication bus 420. The temperature sensor 126 outputs a signal according to the temperature K around 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 shown in FIG. 4, 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.

[0046] As shown in FIG. 5, the motor driver 123 has H-bridge circuits 123A and 123B, and drives the stepping motor 66 in a bipolar manner.

[0047] The H-bridge circuit 123A is connected to the A-phase coil 61c. The H-bridge circuit 123A has switches SW11, SW12, SW13, and SW14. When a current flows from the terminal A1 to the terminal A2 of the A-phase coil 61c, the switches SW11 and SW14 are turned ON and the switches SW12 and SW13 are turned OFF. When a current flows from the terminal A2 to the terminal A1 of the A-phase coil 61c, the switches SW12 and SW13 are turned ON and the switches SW11 and SW14 are turned OFF.

[0048] The H-bridge circuit 123A is connected to a reference potential (GND) via a current detection resistor 127A. A voltage Va corresponding to a current (A-phase current Ia) supplied to the A-phase coil 61c is generated at the terminal of the current detection resistor 127A. The terminal of the current detection resistor 127A is connected to the CPU 121 via an amplifier (not shown) and an analog-digital converter 128A. The CPU 121 inputs a pulse width modulation (PWM) signal to the switches SW11, SW12, SW13, and SW14. The CPU 121 adjusts the duty ratio (A-phase duty ratio 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 by the PWM method.

[0049] The H-bridge circuit 123B is connected to the B-phase coil 62c. The H-bridge circuit 123B has switches SW21, SW22, SW23, and SW24. When a current flows from the terminal B1 to the terminal B2 of the B-phase coil 62c, the switches SW21 and SW24 are turned ON and the switches SW22 and SW23 are turned OFF. When a current flows from the terminal B2 to the terminal B1 of the B-phase coil 62c, the switches SW22 and SW23 are turned ON and the switches SW21 and SW24 are turned OFF.

[0050] The H-bridge circuit 123B is connected to a reference potential (GND) via a current detection resistor 127B. A voltage Vb corresponding to a current (B-phase current Ib) supplied to the B-phase coil 62c is generated at the terminal of the current detection resistor 127B. The terminal of the current detection resistor 127B is connected to the CPU 121 via an amplifier (not shown) and an analog-digital converter 128B. The CPU 121 inputs a PWM signal to the switches SW21, SW22, SW23, and SW24. The CPU 121 adjusts the duty ratio (B-phase duty ratio 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 by the PWM method.

[0051] The PWM signal is ON, OFF, or ON and OFF at a specified pulse period Tp. The duty ratio of a PWM signal is the ratio (Ton / Tp) of the pulse period Tp to the ON time Ton of the PWM signal. When the duty ratio is 0%, the PWM signal is OFF for the entire pulse period Tp. When the duty ratio 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 ratio is 100%, the PWM signal is ON for the entire pulse period Tp.

[0052] If the magnitude (absolute value) of the current flowing through the A-phase coil 61c is the same, the A-phase duty ratio Da will be the same even if the direction of the current is different. The direction of the current is from the terminal A1 to the terminal A2, or from the terminal A2 to the terminal A1. The impedance of the A-phase coil 61c (the impedance between the terminal A1 and the terminal A2) changes when an abnormality occurs in the A-phase coil 61c. The abnormality includes a short circuit, a layer short circuit, and a disconnection. When the impedance of the A-phase coil 61c changes, the time required for a predetermined amount of current to flow through 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 ratio Da changes. For example, when the impedance of the A-phase coil 61c becomes small, the rise time and fall time of the current flowing through the A-phase coil 61c in response to the PWM signal become shorter, and a predetermined 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 go from 0 to its maximum value, and the fall time is the time it takes for the current to go from its maximum value to 0. Fig. 6A shows a schematic waveform (voltage waveform) of the PWM signal before the short circuit, and Fig. 6B shows a schematic waveform of the PWM signal after the short circuit. The same applies to the B-phase coil 62c as to the A-phase coil 61c.

[0053] The magnet rotor 31 rotates when multiple pulses P (P[1] to P[8]) are input to the stepping motor 66. Specifically, the magnet rotor 31 rotates when a current corresponding to the pulses P is supplied to the stator 60 of the stepping motor 66. In this specification, "inputting the 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 multiple pulses P have an order, and are repeatedly input to the stepping motor 66 in ascending or descending order.

[0054] A phase A current target value Ita and a phase B current target value Itb are set for each of the multiple pulses P. FIG. 7 shows the correspondence between the pulses P and the phase A current target value Ita and the phase B current target value Itb. FIG. 8 shows the current waveforms of the phase A current Ia and the phase B current Ib that flow in the order of the multiple pulses P. In FIG. 8, the phase A current Ia has the same magnitude and direction as the phase A current target value Ita, and the phase B current Ib has the same magnitude and direction as the phase B current target value Itb. In FIG. 7 and FIG. 8, the signs (+ / -) indicate the direction in which the current flows. "+" 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 no current flows (OFF).

[0055] In this embodiment, For pulse P[1], the A-phase current target value Ita is set to "+I2", and the B-phase current target value Itb is set to "0". For pulse P[2], the A-phase current target value Ita is set to "+I1", and the B-phase current target value Itb is set to "+I1". For pulse P[3], the A-phase current target value Ita is set to "0", and the B-phase current target value Itb is set to "+I2". For pulse P[4], the A-phase current target value Ita is set to "-I1", and the B-phase current target value Itb is set to "+I1". For pulse P[5], the A-phase current target value Ita is set to "-I2", and the B-phase current target value Itb is set to "0". For pulse P[6], the A-phase current target value Ita is set to "-I1", and the B-phase current target value Itb is set to "-I1". For pulse P[7], the A-phase current target value Ita is set to "0", and the B-phase current target value Itb is set to "-I2". For pulse P[8], the A-phase current target value Ita is set to "+I1", and the B-phase current target value Itb is set to "-I1". "+I2" and "-I2" have the same current magnitude but different current directions. "+I1" and "-I1" have the same current magnitude but different current directions. "+I2" and "+I1" have different current magnitudes but the same current direction.

[0056] The stepping motor 66 receives pulses P[1] to P[8] in sequence.

[0057] When pulses P are input to the stepping motor 66 in ascending order (the order of P[1] to P[8]), the magnet rotor 31 rotates in the valve closing direction (clockwise in FIG. 3). Specifically, when the CPU 121 supplies an A-phase current Ia, which is controlled to be equal to an A-phase current target value Ita set for the pulses P, to the A-phase coil 61c in the order of the pulses P (ascending order), and supplies a B-phase current Ib, which is controlled to be equal to a B-phase current target value Itb set for the pulses P, to the B-phase coil 62c in the order of the pulses P (ascending order), the magnet rotor 31 rotates in the valve closing direction.

[0058] When pulses P are input to the stepping motor 66 in descending order (the order of P[8] to P[1]), the magnet rotor 31 rotates in the valve-opening direction (counterclockwise in FIG. 3). Specifically, when the CPU 121 supplies an A-phase current Ia, which is controlled to be equal to an A-phase current target value Ita set for the pulses P, to the A-phase coil 61c in the order of the pulses P (descending order), and supplies a B-phase current Ib, which is controlled to be equal to a B-phase current target value Itb set for the pulses P, to the B-phase coil 62c in the order of the pulses P (descending order), the magnet rotor 31 rotates in the valve-opening direction.

[0059] The A-phase current Ia being equal to the A-phase current target value Ita means that the magnitude and direction of the A-phase current Ia are the same as those of the A-phase current target value Ita, and the B-phase current Ib being equal to the B-phase current target value Itb means that the magnitude and direction of the B-phase current Ib are the same as those of the B-phase current target value Itb.

[0060] 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 magnet rotor 31 is in the reference position Rx, the movable stopper 32s and the fixed stopper 33s come into contact with each other, and the rotation of the magnet rotor 31 in the valve closing direction is restricted. The number of pulses (initialization number) required to rotate the magnet rotor 31 from the reference position Rx to the fully open position Rz is 500.

[0061] When the magnet rotor 31 rotates, the permanent magnet 45 also rotates, changing the signal of the magnetic sensor 115. When the magnet rotor 31 does not rotate, the permanent magnet 45 does not rotate either, and there is no change in the signal of the magnetic sensor 115. Therefore, the control device 100 can determine whether or not the magnet rotor 31 has rotated, based on the signal of the magnetic sensor 115.

[0062] Next, an example of the processing of the control device 100 will be described with reference to the flowchart of FIG.

[0063] When the control device 100 (specifically, the CPU 121) is powered on, it reads out the current position of the magnet rotor 31 (the current valve opening of the motor-operated valve 5) from the non-volatile memory 122 and waits for a command from the air conditioner control device 410.

[0064] The control device 100 receives a command specifying the valve opening of the motor-operated valve 5 from the air conditioner control device 410 (S110). The command includes information regarding the target valve opening of the motor-operated valve 5. When the current valve opening is greater than the target valve opening (Y in S120), the control device 100 inputs pulses P in ascending order (S130). When the current valve opening is smaller than the target valve opening (N in S120, Y in S140), the control device 100 inputs pulses P in descending order (S150). When the current valve opening is the target valve opening (N in S120, N in S140), the control device 100 ends this process and waits for the next command.

[0065] The control device 100 inputs a PWM signal to the H-bridge circuit 123A so that the A-phase current Ia supplied to the A-phase coil 61c becomes "+I2" in response to the input of the pulse P[1], 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 (A-phase duty ratio Da[1]) of the PWM signal input to the H-bridge circuit 123A in the work memory 124. The control device 100 stores the duty ratio (B-phase duty ratio Db[1]) of the PWM signal input to the H-bridge circuit 123B in the work memory 124. The duty ratio stored in the work memory 124 is, for example, the average value of the duty ratio in the input period Tpls of the pulse P, or the duty ratio acquired after the PWM signal has stabilized (for example, when the variation in the duty ratio is small, such as in the latter half of the input period Tpls of the pulse P).

[0066] In response to the input of the pulse P[2], the control device 100 inputs a PWM signal to the H-bridge circuit 123A 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 (A-phase duty ratio Da[2]) of the PWM signal input to the H-bridge circuit 123A in the working memory 124. The control device 100 stores the duty ratio (B-phase duty ratio Db[2]) of the PWM signal input to the H-bridge circuit 123B in the working memory 124.

[0067] The control device 100 inputs a PWM signal to the H-bridge circuit 123A so that the A-phase current Ia supplied to the A-phase coil 61c becomes "0" in response to the input of the pulse P[3], 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 (A-phase duty ratio Da[3]) of the PWM signal input to the H-bridge circuit 123A in the working memory 124. The control device 100 stores the duty ratio (B-phase duty ratio Db[3]) of the PWM signal input to the H-bridge circuit 123B in the working memory 124.

[0068] The control device 100 inputs a PWM signal to the H-bridge circuit 123A so that the A-phase current Ia supplied to the A-phase coil 61c becomes "-I1" in response to the input of the pulse P[4], 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 (A-phase duty ratio Da[4]) of the PWM signal input to the H-bridge circuit 123A in the working memory 124. The control device 100 stores the duty ratio (B-phase duty ratio Db[4]) of the PWM signal input to the H-bridge circuit 123B in the working memory 124.

[0069] The control device 100 inputs a PWM signal to the H-bridge circuit 123A so that the A-phase current Ia supplied to the A-phase coil 61c becomes "-I2" in response to the input of the pulse P[5], 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 (A-phase duty ratio Da[5]) of the PWM signal input to the H-bridge circuit 123A in the working memory 124. The control device 100 stores the duty ratio (B-phase duty ratio Db[5]) of the PWM signal input to the H-bridge circuit 123B in the working memory 124.

[0070] The control device 100 inputs a PWM signal to the H-bridge circuit 123A so that the A-phase current Ia supplied to the A-phase coil 61c becomes "-I1" in response to the input of the pulse P[6], 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 (A-phase duty ratio Da[6]) of the PWM signal input to the H-bridge circuit 123A in the working memory 124. The control device 100 stores the duty ratio (B-phase duty ratio Db[6]) of the PWM signal input to the H-bridge circuit 123B in the working memory 124.

[0071] The control device 100 inputs a PWM signal to the H-bridge circuit 123A so that the A-phase current Ia supplied to the A-phase coil 61c becomes "0" in response to the input of the pulse P[7], 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 (A-phase duty ratio Da[7]) of the PWM signal input to the H-bridge circuit 123A in the working memory 124. The control device 100 stores the duty ratio (B-phase duty ratio Db[7]) of the PWM signal input to the H-bridge circuit 123B in the working memory 124.

[0072] The control device 100 inputs a PWM signal to the H-bridge circuit 123A so that the A-phase current Ia supplied to the A-phase coil 61c becomes "+I1" in response to the input of the pulse P[8], 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 (A-phase duty ratio Da[8]) of the PWM signal input to the H-bridge circuit 123A in the working memory 124. The control device 100 stores the duty ratio (B-phase duty ratio Db[8]) of the PWM signal input to the H-bridge circuit 123B in the working memory 124.

[0073] The control device 100 compares the A-phase duty ratio Da with the B-phase duty ratio Db in response to the input of the pulse P (S160). When the control device 100 detects based on the comparison result that no abnormality has occurred in the A-phase coil 61c and the B-phase coil 62c (N in S170), the process returns to step S120. When the control device 100 detects based on the comparison result that an abnormality has occurred in the A-phase coil 61c or the B-phase coil 62c (Y in S170), the control device 100 transmits information indicating a malfunction of the motor-operated valve 5 to the air conditioner control device 410 (S180), and ends this process.

[0074] Next, a method of comparing the A-phase duty ratio Da with the B-phase duty ratio Db and a method of detecting an abnormality will be described.

[0075] When the pulses P are input in ascending order, the control device 100 compares the B-phase duty ratio Db[K] obtained in response to the input of the pulse P[K] with the A-phase duty ratio Da[J] obtained in response to the input of the pulse P[J] that is two pulses before 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.

[0076] in particular, When the control device 100 acquires the B-phase duty ratio Db[1] in response to the input of the pulse P[1], it compares the B-phase duty ratio Db[1] with the A-phase duty ratio Da[7] acquired in response to the input of the pulse P[7] that is two pulses before the pulse P[1]. When the control device 100 acquires the B-phase duty ratio Db[2] in response to the input of the pulse P[2], it compares the B-phase duty ratio Db[2] with the A-phase duty ratio Da[8] acquired in response to the input of the pulse P[8] that is two pulses before the pulse P[2]. When the control device 100 acquires the B-phase duty ratio Db[3] in response to the input of the pulse P[3], it compares the B-phase duty ratio Db[3] with the A-phase duty ratio Da[1] acquired in response to the input of the pulse P[1] that is two pulses before the pulse P[3]. When the control device 100 acquires the B-phase duty ratio Db[4] in response to the input of the pulse P[4], it compares the B-phase duty ratio Db[4] with the A-phase duty ratio Da[2] acquired in response to the input of the pulse P[2] that is two pulses before the pulse P[4]. When the control device 100 acquires the B-phase duty ratio Db[5] in response to the input of the pulse P[5], it compares the B-phase duty ratio Db[5] with the A-phase duty ratio Da[3] acquired in response to the input of the pulse P[3] that is two pulses before the pulse P[5]. When the control device 100 acquires the B-phase duty ratio Db[6] in response to the input of the pulse P[6], it compares the B-phase duty ratio Db[6] with the A-phase duty ratio Da[4] acquired in response to the input of the pulse P[4] that is two pulses before the pulse P[6]. When the control device 100 acquires the B-phase duty ratio Db[7] in response to the input of the pulse P[7], it compares the B-phase duty ratio Db[7] with the A-phase duty ratio Da[5] acquired in response to the input of the pulse P[5] that is two pulses before the pulse P[7]. When the control device 100 acquires the B-phase duty ratio Db[8] in response to the input of the pulse P[8], it compares the B-phase duty ratio Db[8] with the A-phase duty ratio Da[6] acquired in response to the input of the pulse P[6] that is two pulses before the pulse P[8].

[0077] Then, the control device 100 compares the A-phase duty ratio Da[J] with the B-phase duty ratio Db[K], and when the difference between them is equal to or less than a predetermined judgment reference value, determines that no abnormality has occurred in the A-phase coil 61c and the B-phase coil 62c. The judgment reference value is, for example, 3 to 20%. When the difference exceeds the predetermined judgment 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, detects that an abnormality has occurred in the A-phase coil 61c or the B-phase coil 62c.

[0078] When the pulses P are input in descending order, the control device 100 compares the A-phase duty ratio Da[K] obtained in response to the input of the pulse P[K] with the B-phase duty ratio Db[J] obtained in response to the input of the pulse P[J] that is two pulses before 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.

[0079] in particular, When the control device 100 obtains the A-phase duty ratio Da[8] in response to the input of the pulse P[8], it compares the A-phase duty ratio Da[8] with the B-phase duty ratio Db[2] obtained in response to the input of the pulse P[2] that is two pulses before the pulse P[8]. When the control device 100 obtains the A-phase duty ratio Da[7] in response to the input of the pulse P[7], it compares the A-phase duty ratio Da[7] with the B-phase duty ratio Db[1] obtained in response to the input of the pulse P[1] that is two pulses before the pulse P[7]. When the control device 100 obtains the A-phase duty ratio Da[6] in response to the input of the pulse P[6], it compares the A-phase duty ratio Da[6] with the B-phase duty ratio Db[8] obtained in response to the input of the pulse P[8] that is two pulses before the pulse P[6]. When the control device 100 obtains the A-phase duty ratio Da[5] in response to the input of the pulse P[5], it compares the A-phase duty ratio Da[5] with the B-phase duty ratio Db[7] obtained in response to the input of the pulse P[7] that is two pulses before the pulse P[5]. When the control device 100 obtains the A-phase duty ratio Da[4] in response to the input of the pulse P[4], it compares the A-phase duty ratio Da[4] with the B-phase duty ratio Db[6] obtained in response to the input of the pulse P[6] that is two pulses before the pulse P[4]. When the control device 100 obtains the A-phase duty ratio Da[3] in response to the input of the pulse P[3], it compares the A-phase duty ratio Da[3] with the B-phase duty ratio Db[5] obtained in response to the input of the pulse P[5] that is two pulses before the pulse P[3]. When the control device 100 obtains the A-phase duty ratio Da[2] in response to the input of the pulse P[2], it compares the A-phase duty ratio Da[2] with the B-phase duty ratio Db[4] obtained in response to the input of the pulse P[4] that is two pulses before the pulse P[2]. When the control device 100 obtains the A-phase duty ratio Da[1] in response to the input of the pulse P[1], it compares the A-phase duty ratio Da[1] with the B-phase duty ratio Db[3] obtained in response to the input of the pulse P[3] that is two pulses before the pulse P[1].

[0080] The control device 100 compares the A-phase duty ratio Da[K] with the B-phase duty ratio Db[J], and when the difference between them is equal to or less than a predetermined reference value, determines that no abnormality has occurred in the A-phase coil 61c and the B-phase coil 62c. When the difference exceeds the 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, detects that an abnormality has occurred in the A-phase coil 61c or the B-phase coil 62c.

[0081] In the above-described 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] have at least the same current magnitude.

[0082] When the control device 100 acquires 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] with the B-phase duty ratio Db[2]. When the control device 100 acquires 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], it compares the A-phase duty ratio Da[4] with the B-phase duty ratio Db[4]. When the control device 100 acquires 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] with the B-phase duty ratio Db[6]. When the control device 100 acquires 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] with the B-phase duty ratio Db[8].

[0083] The motor-operated valve device 1 according to the present embodiment includes a motor-operated valve 5 and a control device 100. The motor-operated valve 5 includes a valve body 10 having a valve chamber 14, a valve element 40 arranged in the valve chamber 14, and a stepping motor 66 for moving the valve element 40. The stepping motor 66 includes a magnet rotor 31 and a stator 60 (A-phase stator 61, B-phase stator 62). The control device 100 controls the motor-operated 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 the PWM method. The control device 100 detects that an abnormality has occurred in the A-phase coil 61c or the B-phase coil 62c based on a comparison between the A-phase duty ratio Da related to the A-phase current Ia and the B-phase duty ratio Db related to the B-phase current Ib.

[0084] For example, when the driving voltage or the ambient temperature of the stepping motor 66 changes, both the A-phase duty ratio Da and the B-phase duty ratio Db change. In this case, the relationship between the A-phase duty ratio Da and the B-phase duty ratio Db does not change. 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 ratio Da or the B-phase duty ratio Db changes. In this case, the relationship between the A-phase duty ratio Da and the B-phase duty ratio Db changes. Therefore, the control device 100 can determine that an abnormality has occurred in the A-phase coil 61c or the B-phase coil 62c when there is a change in the relationship by comparing the A-phase duty ratio Da and the B-phase duty ratio Db. The relationship is, for example, a difference value between the A-phase duty ratio Da and the B-phase duty ratio Db. Therefore, the control device 100 can suppress erroneous detection of an abnormality in the coil due to fluctuations in the driving voltage of the stepping motor 66 or the ambient temperature, and can detect a failure in the stepping motor 66 more accurately.

[0085] Moreover, the control device 100 compares the A-phase duty ratio Da associated with the A-phase current Ia controlled to be equal to the A-phase current target value Ita with the B-phase duty ratio Db associated with the B-phase current Ib controlled to be equal to the B-phase current target value Itb having the same magnitude as the A-phase current target value Ita. In this manner, when no abnormality occurs in the A-phase coil 61c and the B-phase coil 62c, the A-phase duty ratio Da and the B-phase duty ratio Db are the same, and when an abnormality occurs in the A-phase coil 61c or the B-phase coil 62c, the A-phase duty ratio Da and the B-phase duty ratio Db are different. Therefore, the control device 100 can compare the A-phase duty ratio Da and the B-phase duty ratio Db by simple processing.

[0086] The control device 100 may compare an A-phase duty ratio Da associated with an A-phase current Ia controlled to be equal to an A-phase current target value Ita with a B-phase duty ratio Db associated with a B-phase current Ib controlled to be equal to a B-phase current target value Itb having a magnitude different from the A-phase current target value Ita. In this case, the control device 100 compares the A-phase duty ratio Da with 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) between the A-phase current target value Ita and the B-phase current target value Itb is 1 / 2 and no abnormality occurs in the A-phase coil 61c and the B-phase coil 62c, the ratio (Da / Db) between the A-phase duty ratio Da and the B-phase duty ratio Db is also 1 / 2. Therefore, the control device 100 compares the value obtained by multiplying the A-phase duty ratio Da by two (Da×2) with the B-phase duty ratio Db.

[0087] The control device 100 also compares the A-phase duty ratio Da with the B-phase duty ratio Db when the control device 100 controls the A-phase current Ia and the B-phase current Ib so as to rotate the magnet rotor 31. In this manner, the control device 100 can detect an abnormality in the A-phase coil 61c or the B-phase coil 62c during normal processing (processing for setting the valve opening of the motor-operated valve 5 to a specified target valve opening).

[0088] Further, an A-phase current target value Ita and a B-phase current target value Itb are set for each of the multiple pulses P. When an A-phase current Ia equal to the A-phase current target value Ita set for the multiple pulses P is supplied to the A-phase coil 61c in the order of the multiple pulses P and a B-phase current Ib equal to the B-phase current target value Itb set for the multiple pulses P is supplied to the B-phase coil 62c in the order of the multiple pulses P, the magnet rotor 31 rotates. The control device 100 compares an A-phase duty ratio Da related to the A-phase current Ia controlled to be equal to the A-phase current target value Ita set for one pulse P among the multiple pulses P with a B-phase duty ratio Db related to the B-phase current Ib controlled to be equal to a B-phase current target value Itb set for another pulse P among the multiple pulses P and having the same magnitude 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 and the B-phase duty ratio Db by simple processing. Furthermore, the control device 100 can detect an abnormality in the A-phase coil 61c or the B-phase coil 62c during normal processing.

[0089] The control device 100 of this embodiment has a configuration for detecting an abnormality in the A-phase coil 61c or the B-phase coil 62c in normal processing, but the present invention is not limited to such a configuration. The control device 100 may have a configuration for detecting an abnormality in the A-phase coil 61c or the B-phase coil 62c in initialization processing immediately after power-on. For example, in the initialization processing, the control device 100 inputs a PWM signal to the H-bridge circuit 123A 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 ratio (A-phase duty ratio Da) of the PWM signal input to the H-bridge circuit 123A with the duty ratio (B-phase duty ratio Db) of the PWM signal input to the H-bridge circuit 123B. 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.

[0090] Although the control device 100 of this embodiment controls the current of the motor-operated valve 5 (stepping motor 66), it may also control the voltage of the motor-operated valve 5. In a voltage control configuration, 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 the PWM method. The control device 100 detects that an abnormality has occurred in the A-phase coil 61c or the B-phase coil 62c based on a comparison between the duty ratio related to the A-phase voltage (A-phase voltage duty ratio) and the duty ratio related to the B-phase voltage (B-phase voltage duty ratio).

[0091] In addition, in the voltage control configuration, the control device 100 may compare an A-phase voltage duty ratio associated with an A-phase voltage controlled to be equal to an A-phase voltage target value with a B-phase voltage duty ratio associated with a B-phase voltage controlled to be equal to a B-phase voltage target value that is the same magnitude as the A-phase voltage target value.

[0092] In addition, in the voltage control configuration, the control device 100 may compare the A-phase voltage duty ratio with the B-phase voltage duty ratio when controlling the A-phase voltage and the B-phase voltage so that the magnet rotor 31 rotates.

[0093] The voltage control may be configured as follows. The pulses P have an order, and an A-phase voltage target value and a B-phase voltage target value are set for each of the pulses P. When an A-phase voltage equal to the A-phase voltage target value set for each of the pulses P is supplied to the A-phase coil 61c in the order of the pulses P, and a B-phase voltage equal to the B-phase voltage target value set for each of the pulses P is supplied to the B-phase coil 62c in the order of the pulses P, the magnet rotor 31 rotates. Then, the control device 100 compares an A-phase voltage duty ratio related to an A-phase voltage controlled to be equal to the A-phase voltage target value set for one pulse P among the pulses P with a B-phase voltage duty ratio related to a B-phase voltage controlled to be equal to a B-phase voltage target value that is the same magnitude as the A-phase voltage target value set for the one pulse P, which is set for another pulse P among the pulses P.

[0094] Note that, "the A-phase voltage is equal to the A-phase voltage target value" means that the voltage magnitude and voltage direction of the A-phase voltage are the same as those of the A-phase voltage target value, and "the B-phase voltage is equal to the B-phase voltage target value" means that the voltage magnitude and voltage direction of the B-phase voltage are the same as those of the B-phase voltage target value.

[0095] The control device 100 that controls the voltage of the motor-operated valve 5 also achieves the same (including substantially the same) functions and effects as the control device 100 described above.

[0096] In this embodiment, the control device 100 controls the motor-operated valve 5, but the air conditioner control device 410 may directly control the motor-operated valve 5. In this case, the air conditioner control device 410 is the motor-operated valve control device.

[0097] In this specification, terms indicating the shape of a member, such as "cylinder" or "column", are also used for members having substantially the shape of the term. For example, a "cylindrical member" includes a cylindrical member and a substantially cylindrical member.

[0098] Although the embodiments of the present invention have been described above, the present invention is not limited to these examples. Any addition, deletion, or design change of components by a person skilled in the art to the above-mentioned embodiments, or any combination of features of the embodiments as appropriate, is also included in the scope of the present invention as long as it does not go against the spirit of the present invention. [Explanation of symbols]

[0099] 1...motor-operated valve device, 5...motor-operated valve, 10...valve body, 11...body member, 11a...mounting hole, 11b...upper surface, 12...support member, 12a...fitting hole, 13...connecting member, 14...valve chamber, 15...flow path, 16...flow path, 17...valve port, 18...valve seat, 20...can, 30...drive mechanism, 31...magnet rotor, 32...valve stem holder, 32c...female thread, 32s...movable stopper, 33...guide bush, 33a...first cylindrical portion, 33b...second cylindrical portion, 33c...male thread, 33e...through hole, 33 s...fixed stopper, 34...valve stem, 34a...first portion, 34b...second portion, 34d...step portion, 35...support ring, 36...push nut, 37...valve closing spring, 38...stopper mechanism, 40...valve body, 45...permanent magnet, 46...guide member, 47...support spring, 48...sliding member, 50...stator unit, 60...stator, 61...A-phase stator, 61a...pole teeth, 61b...pole teeth, 61c...A-phase coil, 62...B-phase stator, 62a...pole teeth, 62b...pole teeth, 62c...B Phase coil, 65... terminal, 66... ​​stepping motor, 70... housing, 83... connector, 100... motor-operated valve control device, 110... control board, 111... electric wire, 115... magnetic sensor, 120... microcomputer, 121... CPU, 122... non-volatile memory, 123... motor driver, 123A... H-bridge circuit, 123B... H-bridge circuit, 124... working memory, 125... communication module, 126... temperature sensor, 127A... current detection resistor, 12 7B...current detection resistor, 128A...analog-digital converter, 128B...analog-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 ratio, Db...B-phase duty ratio, L...axis, Rc...valve closed position, Rx...reference position, Rz...fully open position

Claims

1. An electric valve control device for controlling an electric valve, The motor-operated valve includes a valve body having a valve chamber, a valve element disposed in the valve chamber, and a stepping motor for moving the valve element, the stepping motor has a magnet rotor, an A-phase stator, and a B-phase stator; The motor-operated valve control device is an A-phase current supplied to an A-phase coil of the A-phase stator and a B-phase current supplied to a B-phase coil of the B-phase stator are controlled by a PWM method; The motor-operated valve control device detects an abnormality in the A-phase coil or the B-phase coil based on a comparison between a duty ratio related to the A-phase current (hereinafter referred to as the "A-phase duty ratio") and a duty ratio related to the B-phase current (hereinafter referred to as the "B-phase duty ratio").

2. 2. The motor-operated valve control device according to claim 1, wherein the motor-operated valve control device compares the A-phase duty ratio associated with the A-phase current controlled to be equal to an A-phase current target value with the B-phase duty ratio associated with the B-phase current controlled to be equal to a B-phase current target value having the same magnitude as the A-phase current target value.

3. 3. The motor-operated valve control device according to claim 1, wherein the motor-operated valve control device compares the A-phase duty ratio with the B-phase duty ratio when the A-phase current and the B-phase current are controlled so as to rotate the magnet rotor.

4. A plurality of pulses have an order, and an A-phase current target value and a B-phase current target value are set for each of the plurality of pulses; when the A-phase current equal to the A-phase current target value set for each of the plurality of pulses is supplied to the A-phase coil in the order, and the B-phase current equal to the B-phase current target value set for each of the plurality of pulses is supplied to the B-phase coil in the order, the magnet rotor rotates, The motor-operated valve control device is 2. The electric valve control device according to claim 1, wherein the A-phase duty ratio of the A-phase current controlled to be equal to the A-phase current target value set for one pulse of the plurality of pulses is compared with the B-phase duty ratio of the B-phase current controlled to be equal to the B-phase current target value set for another pulse of the plurality of pulses, the B-phase current target value being the same magnitude as the A-phase current target value set for the one pulse.

5. An electric valve control device for controlling an electric valve, The motor-operated valve includes a valve body having a valve chamber, a valve element disposed in the valve chamber, and a stepping motor for moving the valve element, the stepping motor has a magnet rotor, an A-phase stator, and a B-phase stator; The motor-operated valve control device is an A-phase voltage supplied to an A-phase coil of the A-phase stator and a B-phase voltage supplied to a B-phase coil of the B-phase stator are controlled by a PWM method; and detecting an occurrence of an abnormality in the A-phase coil or the B-phase coil based on a comparison between a duty ratio associated with the A-phase voltage and a duty ratio associated with the B-phase voltage.

6. A motor-operated valve device comprising the motor-operated valve and the motor-operated valve control device according to claim 1 or 5.

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