Electric valves and electric valve devices

Abstract

[Problem] To provide an electric valve and an electric valve device that can detect the rotation direction of a stepping motor. [Solution] A magnet rotor 31 of this electric valve 5 has: a drive rotor 311; and a detection rotor 312 coaxially connected to the drive rotor 311. The detection rotor 312 includes an outer circumferential surface which has a cylindrical shape and on which a plurality of detection magnetic poles dp1-dp6 are disposed in the circumferential direction. A magnetic sensor 91 of the electric valve 5 detects a magnetic field of the plurality of detection magnetic poles dp1-dp6. At least three detection magnetic poles among the plurality of detection magnetic poles dp1-dp6 have mutually different circumferential lengths.

Description

[Technical Field]

[0001] The present invention relates to a motor-driven valve, and a motor-operated valve device including the motor-driven valve and a motor-driven valve control device. [Background Art]

[0002] Patent Document 1 discloses an example of a conventional motor-driven valve. The motor-driven valve is incorporated in, for example, an air conditioning system. The motor-driven valve includes a case, a rotor, a stator, and one Hall IC. The rotor is arranged inside the case. The rotor includes a drive rotor and a detection rotor. The stator is arranged outside the case. The rotor and the stator constitute a stepping motor. The Hall IC is arranged outside the case. The output signal of the Hall IC is a signal (binary signal) corresponding to the direction of the magnetic field generated by the detection rotor. [Prior Art Documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2003-329698 [Summary of the Invention] [Problem to be Solved by the Invention]

[0004] The motor-driven valve is controlled by an air conditioning control device. The air conditioning control device inputs pulses to the stepping motor to rotate the rotor. N poles and S poles are arranged on the outer circumferential surface of the detection rotor at equal intervals in the circumferential direction, and the output signal of the Hall IC changes at a constant period regardless of which direction the rotor rotates in. Therefore, the air conditioning control device cannot detect the rotation direction of the rotor based on the output signal of the Hall IC, and cannot determine whether the rotor is rotating in the correct direction.

[0005] Therefore, the present invention aims to provide an electric valve and an electric valve device capable of detecting the rotation direction of a stepping motor. [Means for solving the problem]

[0006] To achieve the above objective, an electric valve according to one aspect of the present invention comprises a valve body having a valve port, a stepping motor having a drive rotor and a stator, a valve body that moves relative to the valve port in accordance with the rotation of the drive rotor, a detection rotor connected coaxially with the drive rotor, and a magnetic sensor, wherein the detection rotor has a cylindrical outer surface on which a plurality of detection magnetic poles are arranged in the circumferential direction, the magnetic sensor detects the magnetic field of the plurality of detection magnetic poles, and at least three of the plurality of detection magnetic poles have different circumferential lengths.

[0007] According to the present invention, when the detection rotor rotates together with the drive rotor, the magnetic fields of multiple detection poles are sequentially detected by the magnetic sensor. The output signal of the magnetic sensor includes signal portions corresponding to at least three detection poles with different circumferential lengths. The order in which these signal portions appear when the detection rotor rotates in a first direction is different from the order in which they appear when the detection rotor rotates in a second direction. Therefore, the rotation direction of the drive rotor can be detected based on the output signal of the magnetic sensor.

[0008] In the present invention, it is preferable that the plurality of detection magnetic poles are arranged circumferentially on the outer surface of the detection rotor such that their polarities alternate, and at least one of their polarities and circumferential lengths is different from one another.

[0009] According to the present invention, when the detection rotor rotates together with the drive rotor, the magnetic fields of multiple detection poles are sequentially detected by the magnetic sensor. The output signal of the magnetic sensor includes signal portions corresponding to the multiple detection poles. Since the multiple detection poles differ from each other in at least one of their polarity and circumferential length, the signal portions differ from each other in at least one of their signal value and length. The order in which the signal portions appear when the detection rotor rotates in a first direction is different from the order in which the signal portions appear when the detection rotor rotates in a second direction. Therefore, the rotation direction of the drive rotor can be detected based on the output signal of the magnetic sensor.

[0010] Furthermore, the positions (angles) of the boundaries between multiple detection magnetic poles (N pole, S pole) on the outer surface of the detection rotor are predetermined. When the detection rotor rotates and these boundaries pass through the detection area of ​​the magnetic sensor, the output signal changes from the first signal value to the second signal value, or vice versa. In a configuration where the magnetic sensor outputs a binary signal corresponding to the direction of the magnetic field, for example, the first signal value is "H" and the second signal value is "L". In a configuration where the magnetic sensor outputs an analog signal corresponding to the direction of the magnetic field, for example, the first signal value is a positive value and the second signal value is a negative value. Therefore, the rotation angle of the drive rotor can be obtained based on the output signal of the magnetic sensor.

[0011] In the present invention, it is preferable that the plurality of detection magnetic poles are arranged in order of their circumferential length. In this way, the length of the signal portion corresponding to the detection magnetic pole in the output signal of the magnetic sensor gradually increases or decreases depending on the rotation direction of the detection rotor. Therefore, the rotation direction of the drive rotor can be detected more easily based on the output signal of the magnetic sensor.

[0012] In the present invention, it is preferable that the electric valve further includes a stopper mechanism that restricts the rotation of the drive rotor in a first direction when the drive rotor is in a reference position, and that when the drive rotor is in the reference position, the magnetic sensor detects the magnetic field of one of the plurality of detection poles (hereinafter referred to as the "reference detection pole"). In this way, when the rotation of the drive rotor in the first direction is restricted at the reference position, the output of the signal portion corresponding to the reference detection pole in the output signal of the magnetic sensor is not completed. As a result, when the signal portion corresponding to the reference detection pole is not included in the output signal of the magnetic sensor, it can be estimated that the drive rotor is in the reference position. Therefore, it is possible to detect that the drive rotor is in the reference position based on the output signal of the magnetic sensor.

[0013] In the present invention, it is preferable that the reference detection magnetic pole is the detection magnetic pole having the shortest circumferential length among the plurality of detection magnetic poles. By doing so, it is possible to determine relatively quickly whether or not the output of the signal portion corresponding to the reference detection magnetic pole in the output signal of the magnetic sensor has been completed. Therefore, it is possible to detect relatively quickly that the drive rotor is in the reference position based on the output signal of the magnetic sensor.

[0014] In the present invention, it is preferable that the drive rotor has a cylindrical outer surface and a plurality of drive magnetic poles, the plurality of drive magnetic poles are arranged circumferentially on the outer surface of the drive rotor with alternating polarities, each having the same circumferential length, the circumferential length of the reference detection magnetic pole is less than or equal to the circumferential length of the drive magnetic poles, and a straight line passing through the circumferential center of the reference detection magnetic pole passes through the circumferential center of one of the plurality of drive magnetic poles. By doing so, it is possible to determine more quickly whether the output of the signal portion corresponding to the reference detection magnetic pole in the output signal of the magnetic sensor has been completed. Therefore, it is possible to detect more quickly that the drive rotor is in the reference position based on the output signal of the magnetic sensor.

[0015] In the present invention, it is preferable that the center angle corresponding to the circumferential length of the reference detection magnetic pole is less than twice the step angle of the stepping motor. By doing so, the signal portion corresponding to the reference detection magnetic pole in the output signal of the magnetic sensor is approximately the length of one pulse, and it is possible to determine more quickly whether or not the output of the signal portion corresponding to the reference detection magnetic pole in the output signal of the magnetic sensor has been completed. Therefore, it is possible to detect more quickly that the drive rotor is in the reference position based on the output signal of the magnetic sensor.

[0016] To achieve the above objective, another embodiment of the present invention provides an electric valve device comprising an electric valve and an electric valve control device for controlling the electric valve, wherein the electric valve control device acquires the rotation direction of the drive rotor based on the output signal of the magnetic sensor. According to the present invention, the electric valve control device can detect the rotation direction of the drive rotor of the electric valve with simple control.

[0017] In the present invention, it is preferable that the electric valve control device inputs pulses to the stepping motor so that the drive rotor rotates, and detects stepping motor loss based on the rotation angle of the drive rotor obtained based on the output signal of the magnetic sensor and the rotation angle of the drive rotor corresponding to the pulse input to the stepping motor. In this way, the electric valve control device can detect stepping motor loss with simple control.

[0018] In order to achieve the above object, a motorized valve device according to another aspect of the present invention is a motorized valve device including the motorized valve and a motorized valve control device that controls the motorized valve, wherein, in the operation of the motorized valve control device positioning the drive rotor at the reference position, pulses are input to the stepping motor such that the drive rotor rotates in the first direction, and input of pulses to the stepping motor is stopped when the output signal of the magnetic sensor does not include a signal portion corresponding to the reference detection magnetic pole. According to the present invention, the motorized valve control device can stop the stepping motor after positioning the drive rotor at the reference position through simple control. Effects of the Invention

[0019] According to the present invention, the rotation direction of the stepping motor can be detected with a simple configuration. Brief Description of the Drawings

[0020] [Figure 1] It is a block diagram of an air conditioner system including a motorized valve device according to an embodiment of the present invention. [Figure 2] It is a cross-sectional view of the motorized valve device. [Figure 3] It is a perspective view of a magnet rotor. [Figure 4] It are a bottom view and a plan view of the magnet rotor. [Figure 5] It is a developed plan view of the outer peripheral surface of the magnet rotor. [Figure 6] It is a cross-sectional view of a stator unit. [Figure 7] It is a perspective view of a sensor substrate and a substrate support member. [Figure 8] It is another perspective view of the sensor substrate and the substrate support member. [Figure 9] It is a diagram explaining the arrangement of magnetic sensors. [Figure 10] It is a diagram schematically showing the positional relationship between the pole teeth of the stator and the magnetic sensors. [Figure 11] It is a perspective view of a control board. [Figure 12] This diagram shows the connection relationships between the microcomputer, stepping motor, and magnetic sensor. [Figure 13] This figure shows an example of the relationship between pulse and drive current. [Figure 14] This diagram schematically shows the positional relationship between the magnet rotor and the stator (when pulse P[1] is input). [Figure 15] This diagram schematically shows the positional relationship between the magnet rotor and the stator (when pulse P[2] is input). [Figure 16] This diagram schematically shows the positional relationship between the magnet rotor and the stator (when pulse P[3] is input). [Figure 17] This diagram schematically shows the positional relationship between the magnet rotor and the stator (when pulse P[4] is input). [Figure 18] This diagram schematically shows the positional relationship between the magnet rotor and the stator (when pulse P[5] is input). [Figure 19] This diagram schematically shows the positional relationship between the magnet rotor and the stator (when pulse P[6] is input). [Figure 20] This diagram schematically shows the positional relationship between the magnet rotor and the stator (when pulse P[7] is input). [Figure 21] This diagram schematically shows the positional relationship between the magnet rotor and the stator (when pulse P[8] is input). [Figure 22] This figure shows an example of the output signal from a magnetic sensor. [Figure 23] This figure shows an example of the relationship between time, pulses input to the stepping motor, the rotation direction and angle of the magnet rotor, and the output signal of the magnetic sensor. [Figure 24] This diagram illustrates the movement of a magnetic rotor when its rotation in the first direction is restricted. [Figure 25] This diagram illustrates the movement of the magnetic rotor when its rotation in the first direction is restricted. (Continued from Figure 24). [Figure 26] This flowchart shows an example of the operation of an electric valve control device. [Figure 27] These are a bottom view and a top view showing the configuration of the first modified example of the magnet rotor. [Figure 28] These are a bottom view and a top view showing the configuration of a second modified example of the magnet rotor. [Modes for carrying out the invention]

[0021] Hereinafter, an electric valve device according to one embodiment of the present invention will be described with reference to Figures 1 to 26.

[0022] Figure 1 is a block diagram of an air conditioning system having an electric valve device according to one embodiment of the present invention. Figure 2 is a cross-sectional view of the electric valve device having an electric valve and an electric valve control device. Figure 3 is a perspective view of the magnet rotor of the electric valve. Figure 4A is a bottom view of the magnet rotor. Figure 4B is a plan view of the magnet rotor. Figure 5 is a diagram showing the outer circumferential surface of the magnet rotor unfolded in a planar manner. In Figures 4A, 4B, and 5, the magnetic poles of the drive rotor and the detection rotor of the magnet rotor are schematically shown. Figure 6 is a cross-sectional view of the stator unit of the electric valve. Figure 7 is a perspective view of the sensor substrate and substrate support member of the electric valve. Figure 8 is another perspective view of the sensor substrate and substrate support member. Figure 9 is a diagram illustrating the arrangement of the magnetic sensor of the electric valve. Figure 10 is a diagram schematically showing the positional relationship between the pole teeth of the stator and the magnetic sensor. Figure 11 is a perspective view of the control board of the electric valve control device. Figure 12 is a diagram schematically showing the connection relationship between the microcomputer of the electric valve control device, the stepping motor of the electric valve, and the magnetic sensor. Figure 13 shows an example of the relationship between pulses and the drive current supplied to the stators (A-phase stator, B-phase stator). Figures 14 to 21 schematically show the positional relationship between the magnet rotor and the stator. Figures 14 to 21 correspond to when pulses P[1] to P[8] are input to the stepping motor. Figure 22A shows an example of the output signal of the magnetic sensor when the magnet rotor is rotating in the first direction. Figure 22B shows an example of the output signal of the magnetic sensor when the magnet rotor is rotating in the second direction. Figure 23 shows an example of the relationship between time, pulses input to the stepping motor, the rotation direction and angle of the magnet rotor, and the output signal of the magnetic sensor. Figures 24 and 25 illustrate the movement of the magnet rotor when its rotation in the first direction is restricted. Figure 26 is a flowchart showing an example of the operation of the electric valve control device. In Figures 2 and 6, the magnetic sensor is shown by a dashed line. In Figures 2, 6-9, and 11, the X direction indicated by arrow X represents the left-right direction, the Y direction indicated by arrow Y represents the front-back direction, and the Z direction indicated by arrow Z represents the up-down direction.In arrow X, the side with the letter "X" points to the right; in arrow Y, the side with the letter "Y" points forward; and in arrow Z, the side with the letter "Z" points upward.

[0023] The electric valve device 1 according to this embodiment comprises an electric valve 5 and an electric valve control device (hereinafter simply referred to as "control device 100").

[0024] The electric valve device 1 is incorporated, for example, into the air conditioning system 400 shown in Figure 1. The air conditioning system 400 includes a compressor 401, a condenser 402, the electric valve device 1 (electric valve 5), and an evaporator 403. The compressor 401, condenser 402, electric valve 5, and evaporator 403 are connected in sequence via piping 405. The air conditioning system 400 also includes an air conditioning control device 410. The air conditioning control device 410 is communicatively connected to the electric valve device 1 (control device 100) via a communication bus 420. The air conditioning control device 410 uses the electric valve device 1 to control the flow rate of refrigerant flowing through the piping 405.

[0025] As shown in Figure 2, the electric valve 5 includes a valve body 10, a can 20, a drive mechanism 30, a valve element 40, a stator unit 50, a sensor substrate 90, and a magnetic sensor 91.

[0026] The valve body 10 is made of a metal such as an aluminum alloy. The valve body 10 includes a main body member 11, a support member 12, and a connecting member 13. The main body member 11 has a rectangular parallelepiped shape. The main body member 11 has a mounting hole 11a. The mounting hole 11a is located on the upper surface 11b of the main body member 11. The support member 12 has a cylindrical shape. The lower part of the support member 12 is located in the mounting hole 11a. The support member 12 is attached to the main body member 11 by a screw structure. The upper part of the support member 12 protrudes from the upper surface 11b of the main body member 11. The support member 12 has a fitting hole 12a. The fitting hole 12a is located on the upper surface of the support member 12. The main body member 11 includes 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 opening 17. The valve seat 18 surrounds the valve opening 17 in the valve chamber 14. The connecting member 13 has an annular plate shape. The inner periphery of the connecting member 13 is joined to the upper part of the support member 12.

[0027] The can 20 is made of a metal such as stainless steel. The can 20 has a cylindrical shape. The can 20 is closed at the top and open at the bottom. The bottom end of the can 20 is joined to the outer edge of the connecting member 13. The can 20 is a case.

[0028] The drive mechanism 30 moves the valve body 40 in the vertical direction (axis L direction). The drive mechanism 30 is located inside the can 20. The drive mechanism 30 includes a magnet rotor 31, a valve stem holder 32, and a guide bush 33.

[0029] Figures 3 to 5 show the magnet rotor 31. 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. The magnet rotor 31 integrally includes a drive rotor 311 and a detection rotor 312.

[0030] The drive rotor 311 has a cylindrical outer surface. The drive rotor 311 has a plurality of drive poles cp. The plurality of drive poles cp are arranged on the outer surface of the drive rotor 311. The plurality of drive poles cp extend in the vertical direction. The plurality of drive poles cp consist of a plurality of N poles and a plurality of S poles. The plurality of N poles and S poles are arranged alternately at equal intervals in the circumferential direction. In this embodiment, the drive rotor 311 has 12 N poles and 12 S poles, and the total number of the plurality of drive poles cp is 24. The circumferential lengths of the plurality of drive poles cp are the same. The central angle α1 corresponding to the circumferential length of the plurality of drive poles cp is 15 degrees. The plurality of drive poles cp are arranged circumferentially on the outer surface of the drive rotor 311 with alternating polarities, and each has the same circumferential length.

[0031] The detection rotor 312 is connected to the upper end of the drive rotor 311. The detection rotor 312 may also be connected to the lower end of the drive rotor 311. The detection rotor 312 is coaxially positioned with the drive rotor 311. The detection rotor 312 rotates together with the drive rotor 311. The outer diameter of the detection rotor 312 is the same as the outer diameter of the drive rotor 311. The detection rotor 312 has a cylindrical outer surface.

[0032] The detection rotor 312 has multiple detection magnetic poles dp1 to dp6. The detection magnetic poles dp1 to dp6 are arranged on the outer circumferential surface of the detection rotor 312. The multiple detection magnetic poles dp1 to dp6 consist of multiple north poles and multiple south poles. Detection magnetic poles dp1, dp3, and dp5 are north poles. Detection magnetic poles dp2, dp4, and dp6 are south poles. The detection magnetic poles dp1 to dp6 are arranged circumferentially on the outer circumferential surface of the detection rotor 312 so that their polarities alternate.

[0033] The central angle β1 corresponding to the circumferential length of the detected magnetic pole dp1 is 10 degrees. The central angle β2 corresponding to the circumferential length of the detected magnetic pole dp2 is 30 degrees. The central angle β3 corresponding to the circumferential length of the detected magnetic pole dp3 is 45 degrees. A central angle β4 corresponding to the circumferential length of the detection magnetic pole dp4 is 50 degrees. A central angle β5 corresponding to the circumferential length of the detection magnetic pole dp5 is 100 degrees. A central angle β6 corresponding to the circumferential length of the detection magnetic pole dp6 is 125 degrees.

[0034] The detection magnetic poles dp1 to dp6 differ in at least one of polarity and circumferential length. For the detection magnetic poles dp1 to dp6, if their polarities are different, their circumferential lengths may be the same. For the detection magnetic poles dp1 to dp6, if their circumferential lengths are different, their polarities may be the same.

[0035] The circumferential lengths of the detection magnetic poles dp1, dp3, and dp5 are different from each other. When the circumferential lengths of the detection magnetic poles dp1, dp3, and dp5 are denoted as B1, B3, and B5 respectively, the relation B1 < B3 < B5 holds true. The circumferential lengths of the detection magnetic poles dp2, dp4, and dp6 are different from each other. When the circumferential lengths of the detection magnetic poles dp2, dp4, and dp6 are denoted as B2, B4, and B6 respectively, the relation B2 < B4 < B6 holds true. In the motor-operated valve 5, the relation B1 < B2 < B3 < B4 < B5 < B6 holds true. Among the circumferential lengths of the detection magnetic poles dp1 to dp6, the detection magnetic pole dp1 has the shortest circumferential length, and the detection magnetic pole dp6 has the longest circumferential length. The detection magnetic pole dp1 is the minimum detection magnetic pole. The detection magnetic pole dp6 is the maximum detection magnetic pole.

[0036] The detection magnetic poles dp1 to dp6 are arranged in the order of their circumferential lengths. In FIG. 4B, the detection magnetic poles dp1, dp2, dp3, dp4, dp5, and dp6 are arranged in this order in the counterclockwise direction (left rotation direction). The circumferential length of the detection magnetic poles dp1 to dp6 gradually increases as going in the counterclockwise direction. The circumferential length of the detection magnetic poles dp1 to dp6 may gradually increase as going in the clockwise direction.

[0037] In the electric valve 5, the circumferential length of the detection magnetic pole dp1 is smaller than the circumferential length of the drive magnetic pole cp. When the circumferential length of the drive magnetic pole cp is defined as A1, B1 < A1 holds. It is preferable that B1 ≤ A1 holds. The circumferential length of the detection magnetic pole dp1 may be larger than the circumferential length of the drive magnetic pole cp. In the electric valve 5, a line E1, which is a straight line passing through the circumferential center of the detection magnetic pole dp1, passes through the circumferential center of one drive magnetic pole cp1 among the plurality of drive magnetic poles cp. The line E1 may be offset from the circumferential center of the drive magnetic pole cp1.

[0038] As shown in FIG. 5, in the detection rotor 312, when the circumferential center of the detection magnetic pole dp1 is set to 0 degrees, the boundary between the detection magnetic pole dp1 and the detection magnetic pole dp6 is located at a position rotated by 5 degrees around the axis L, the boundary between the detection magnetic pole dp6 and the detection magnetic pole dp5 is located at a position rotated by 130 degrees around the axis L, the boundary between the detection magnetic pole dp5 and the detection magnetic pole dp4 is located at a position rotated by 230 degrees around the axis L, the boundary between the detection magnetic pole dp4 and the detection magnetic pole dp3 is located at a position rotated by 280 degrees around the axis L, the boundary between the detection magnetic pole dp3 and the detection magnetic pole dp2 is located at a position rotated by 325 degrees around the axis L, and the boundary between the detection magnetic pole dp2 and the detection magnetic pole dp1 is located at a position rotated by 355 degrees around the axis L.

[0039] The valve shaft holder 32 has a cylindrical shape. The valve shaft holder 32 is closed at the upper end and open at the lower end. A support ring 35 is fixed to the upper wall of the valve shaft holder 32. The support ring 35 connects the magnet rotor 31 and the valve shaft holder 32. An internal thread 32c is provided on the inner peripheral surface of the valve shaft holder 32.

[0040] The guide bush 33 integrally comprises a base portion 33a and a support portion 33b. The base portion 33a has a cylindrical shape. The support portion 33b also has a cylindrical shape. The outer diameter of the support portion 33b is smaller than the outer diameter of the base portion 33a. The support portion 33b is coaxially connected to the upper end of the base portion 33a. A male thread 33c is provided on the outer circumferential surface of the support portion 33b. The male thread 33c is screwed into the female thread 32c of the valve stem holder 32. The base portion 33a is press-fitted into the fitting hole 12a of the support member 12 of the valve body 10. The guide bush 33 is coupled to the valve body 10.

[0041] A movable stopper 32s is fixed to the valve stem holder 32. A fixed stopper 33s is fixed to the base 33a of the guide bush 33. When the movable stopper 32s and the fixed stopper 33s come into contact, the rotation of the valve stem holder 32 (i.e., the magnet rotor 31) in the first 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 first direction.

[0042] The valve body 40 integrally comprises a first shaft portion 41, a second shaft portion 42, and a valve portion 43. The first shaft portion 41 has a cylindrical shape. The first shaft portion 41 is located inside the guide bush 33 and inside the support member 12. The lower end of the first shaft portion 41 is located in the valve chamber 14. The second shaft portion 42 has a cylindrical shape. The diameter of the second shaft portion 42 is smaller than the diameter of the first shaft portion 41. The second shaft portion 42 is coaxially connected to the upper end of the first shaft portion 41. The second shaft portion 42 is inserted through a hole provided in the upper wall of the valve shaft holder 32. A push nut 36 for retaining the second shaft portion 42 is attached. The valve portion 43 has a frustoconical shape, with its diameter gradually decreasing from the upper end to the lower end. The valve portion 43 is coaxially connected to the lower end of the first shaft portion 41. The valve portion 43 is located in the valve chamber 14. The valve portion 43 faces the valve port 17 in the vertical direction. The valve portion 43 opens and closes the valve port 17. When the valve portion 43 contacts the valve seat 18, the valve port 17 closes. When the valve portion 43 moves away from the valve seat 18, the valve port 17 opens. The valve body 40 has a stepped portion 44. The stepped portion 44 is an annular plane facing upward. The stepped portion 44 is located at the connection point between the first shaft portion 41 and the second shaft portion 42. A valve closing spring 37 is located between the stepped portion 44 and the upper wall portion of the valve stem holder 32. The valve closing spring 37 is a compression coil spring. The valve closing spring 37 pushes the valve body 40 downward. The valve body 40 is formed, for example, by machining a cylindrical workpiece.

[0043] The stator unit 50 includes a stator 60, a housing 70, and a case 80.

[0044] The stator 60 has a cylindrical shape. The stator 60 includes an A-phase stator 61 and a B-phase stator 62.

[0045] The A-phase stator 61 has multiple claw-pole type pole teeth 61a and 61b on its inner circumference. The tips of the pole teeth 61a point downward, and the tips of the pole teeth 61b point upward. The pole teeth 61a and 61b are arranged alternately 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 adjacent pole teeth 61a and 61b is 15 degrees. When the coil 61c of the A-phase stator 61 is energized, the pole teeth 61a and 61b become opposite in polarity.

[0046] The B-phase stator 62 has multiple claw-pole type pole teeth 62a and 62b on its inner circumference. The tips of the pole teeth 62a point downward, and the tips of the pole teeth 62b point upward. The pole teeth 62a and 62b are arranged alternately 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 adjacent pole teeth 62a and 62b is 15 degrees. When the coil 62c of the B-phase stator 62 is energized, the pole teeth 62a and 62b have opposite polarities. The B-phase stator 62 has the same (including substantially the same) configuration as the A-phase stator 61.

[0047] 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 direction of axis L, the angle between adjacent pole teeth 61a of the A-phase stator 61 and pole teeth 62a of the B-phase stator 62 is 7.5 degrees. This angle is half the angle between adjacent pole teeth 61a and 61b, and half the angle between adjacent pole teeth 62a and 62b. The coil 61c of the A-phase stator 61 and the coil 62c of the B-phase stator 62 are connected to multiple terminals 65.

[0048] The housing 70 is made of synthetic resin. The housing 70 has a cylindrical shape. The housing 70 is molded by injection molding. The housing 70 houses the stator 60. The housing 70 is integrally molded (insert molded) with the stator 60. Alternatively, the stator 60 and the housing 70 may be manufactured separately, and the stator 60 may be fitted inside the housing 70.

[0049] The stator unit 50 has an inner space 74 defined by the inner surface of the housing 70 and the inner circumferential surface of the stator 60. The can 20 is positioned in the inner space 74. The stator 60 and the magnet rotor 31 (drive rotor 311) constitute a stepping motor 66. When the stator 60 (coils 61c, 62c) is energized, attractive and repulsive forces act between the drive magnetic pole cp of the drive rotor 311 and the pole teeth 61a, 61b, 62a, 62b of the stator 60, causing the drive rotor 311 to rotate.

[0050] The housing 70 has a substrate space 75. The substrate space 75 extends in the lateral direction (a direction perpendicular to the axis L). The substrate space 75 is located adjacent to the inner space 74. A partition wall 76 is provided between the inner space 74 and the substrate space 75. The partition wall 76 separates the inner space 74 and the substrate space 75. The cross-section of the partition wall 76 (a cross-section perpendicular to the direction of the axis L) has an arc shape that follows the outer circumferential surface of the can 20.

[0051] The case 80 is made of synthetic resin. The case 80 has a rectangular box shape. The case 80 is joined to the housing 70. The internal space 85 of the case 80 is connected to the substrate space 75 through an opening 80a. A connector 83 is provided on the top of the case 80.

[0052] Figures 7 and 8 show the sensor substrate 90. The sensor substrate 90 is a printed circuit board on which electronic components are mounted. The sensor substrate 90 is housed in a substrate space 75. The sensor substrate 90 is oriented laterally. The first end 90a of the sensor substrate 90 is located in the space 85 of the case 80. The second end 90b of the sensor substrate 90 is located near the partition wall 76. A substrate support member 95 is attached to the sensor substrate 90. A boss 87 of the case 80 is located inside the cylindrical portion 97 of the substrate support member 95. The sensor substrate 90 is attached to the boss 87 via the substrate support member 95. One magnetic sensor 91 is mounted on the sensor substrate 90.

[0053] The magnetic sensor 91 is a Hall IC. The output signal K of the magnetic sensor 91 is a binary signal. The magnetic sensor 91 is located at the second end 90b of the sensor substrate 90.

[0054] The magnetic sensor 91 is positioned radially toward the detection rotor 312 of the magnet rotor 31 via the can 20 and the partition wall 76. In other words, the magnetic sensor 91 is positioned to face the detection rotor 312 radially (laterally) via the can 20 and the partition wall 76. The magnetic sensor 91 detects the magnetic field generated by one of the detection magnetic poles dp1 to dp6 that faces the magnetic sensor 91 radially. The magnetic sensor 91 may also be positioned to face the detection rotor 312 vertically.

[0055] The output signal K of the magnetic sensor 91 is a signal corresponding to the direction of the magnetic field generated by the detected magnetic poles dp1 to dp6 of the detection rotor 312. Specifically, when the magnetic sensor 91 detects a magnetic field related to the north pole, it outputs an H signal (first signal value) as the output signal K, and when it detects a magnetic field related to the south pole, it outputs an L signal (second signal value) as the output signal K.

[0056] The output signal K of the magnetic sensor 91 may be an analog signal corresponding to the direction of the magnetic field. The motorized valve 5 may have two or more magnetic sensors 91.

[0057] Figure 9 shows an example of the arrangement of the magnetic sensor 91. Figure 9 is a view from above of the can 20, the magnet rotor 31, the stator 60, the sensor substrate 90, and the magnetic sensor 91. In Figure 9, the can 20 and the magnet rotor 31 are shown in cross-sections cut by a plane including the top surface of the stator 60. In Figure 9, the sensor substrate 90 and the magnetic sensor 91 are shown by dashed lines. In Figure 9, line M1 connects the axis L and the magnetic detection part of the magnetic sensor 91. Line M1 is a straight line perpendicular to the axis L. Line M1 passes through the circumferential center of the pole teeth 61a of the A-phase stator 61 (Figure 14).

[0058] Figure 10 schematically shows an example of the positional relationship between the A-phase stator 61, the B-phase stator 62, and the magnetic sensor 91. As shown in Figure 10, when the A-phase stator 61 and the B-phase stator 62 are viewed radially, the center of the pole teeth 61a of the A-phase stator 61 and the magnetic detection part of the magnetic sensor 91 are positioned on line L1. Line L1 is a straight line parallel to the axis L. Line L1 is perpendicular to line M1.

[0059] 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 (drive rotor 311, detection rotor 312), valve body 40, and stator 60 (A-phase stator 61, B-phase stator 62) each have their central axes coincide with the axis L.

[0060] In the electric valve 5, when the magnet rotor 31 rotates in the first direction, the magnet rotor 31 and the valve stem holder 32 move downward due to 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. The valve stem holder 32 pushes the valve body 40 downward via the valve closing spring 37. The valve body 40 moves downward and contacts the valve seat 18. At this time, the position of the magnet rotor 31 is the closed position Rc. If the magnet rotor 31 rotates further in the first direction from this state, the valve closing spring 37 is compressed and the magnet rotor 31 and the valve stem 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 first direction is restricted. At this time, the position of the magnet rotor 31 is the reference position Rx.

[0061] In the electric valve 5, when the magnet rotor 31 rotates in the second direction, the magnet rotor 31 and the valve stem holder 32 move upward due to 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. The valve stem holder 32 pushes the push nut 36 upward. The valve body 40 moves upward and separates from the valve seat 18. As 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 away from the valve port 17.

[0062] Furthermore, the electric valve 5 may be configured such that the valve body 40 is separated from the valve seat 18 when the magnetic rotor 31 is in the reference position Rx.

[0063] In the electric valve 5, when the magnet rotor 31 is in the reference position Rx, the circumferential center of the detection magnetic pole dp1 is positioned on line M1, and the detection magnetic pole dp1 is aligned radially with the magnetic sensor 91 and the magnet rotor 31. The detection magnetic pole dp1 is the reference detection magnetic pole. When the magnet rotor 31 is in the reference position Rx, any of the detection magnetic poles dp2 to dp6 may be aligned radially with the magnetic sensor 91. The rotation angle of the magnet rotor 31 when it is in the reference position Rx is set to 0 degrees. When the magnet rotor 31 rotates in the second direction, the rotation angle increases, and when it rotates in the first direction, the rotation angle decreases.

[0064] Furthermore, in the electric valve 5, when the magnet rotor 31 is in the reference position Rx, the drive magnetic pole cp1 is aligned radially with the pole teeth 61a of the A-phase stator 61 and the magnet rotor 31.

[0065] The control device 100 includes a control board 110 and a microcomputer 120.

[0066] Figure 11 shows the control board 110. The control board 110 is a printed circuit board on which electronic components are mounted. The control board 110 is housed in the space 85 of the case 80. The control board 110 is oriented vertically. The control board 110 is perpendicular to the sensor board 90. The control board 110 is located near the first end 90a of the sensor board 90. The control board 110 is connected to the sensor board 90 via connection terminals 93. Multiple terminals 65 of the stator 60 are connected to the control board 110. Bosses 87 of the case 80 are positioned in through holes 112 of the control board 110. The control board 110 is mounted on the bosses 87. A microcomputer 120 is mounted on the control board 110.

[0067] As shown in Figures 1 and 12, the microcomputer 120 is an embedded device microcomputer that integrates, for example, a central processing unit (CPU) 121, non-volatile memory 122, a motor driver 123, a working memory 124, and a communication module 125 into a single package. The microcomputer 120 controls the electric valve 5. Note that the non-volatile memory, working memory, communication module, and motor driver may be individual electronic components externally connected to the microcomputer 120.

[0068] The CPU 121 executes programs stored in the non-volatile memory 122 and functions as various functional units. The working memory 124 stores variables used by the various functional units. The communication module 125 is connected to the air conditioner control device 410 via the communication bus 420. The motor driver 123 is connected to the stepping motor 66. Specifically, as shown in Figure 12, the motor driver 123 is connected to the coil 61c of the A-phase stator 61 and the coil 62c of the B-phase stator 62. The motor driver 123 supplies drive current to the coils 61c and 62c according to the pulse P.

[0069] The magnet rotor 31 rotates when pulses P (P[1] to P[8]) are input to the stepping motor 66. Specifically, the magnet rotor 31 rotates when a drive current corresponding to the pulses P is supplied to the stator 60 of the stepping motor 66. In this specification, "pulses P being input to the stepping motor 66" is synonymous with "a drive current corresponding to the pulses P being supplied to the stator 60 of the stepping motor 66". The pulses P are repeatedly input to the stepping motor 66 in ascending or descending order. Pulses P[1] to P[8] represent one cycle of pulses P, and are multiple pulses P that are repeatedly input to the stepping motor 66 in a predetermined order.

[0070] In this embodiment, the excitation mode of the stepping motor 66 is 1-2 phase excitation, and 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, restricting the rotation of the magnet rotor 31 in the first direction. The number of pulses P required to rotate the magnet rotor 31 from the reference position Rx to the fully open position Rz (initialization number) is 500.

[0071] The stepping motor 66 is input with pulses P[1] to P[8] in order, as shown in Figure 13. Figures 14 to 21 schematically show an example of the positional relationship between the magnet rotor 31 and the stator 60 when pulses P[1] to P[8] are input. Figure 14 shows the state where the magnet rotor 31 is at the reference position Rx. In Figure 14, the rotation angle of the magnet rotor 31 is 0 degrees. Figures 14 to 21 schematically show the magnetic poles of the magnet rotor 31 (drive rotor 311, detection rotor 312) and the pole teeth of the stator 60. In Figures 14 to 21, marks (black circles) are placed on the reference pole teeth 61a and the reference magnetic pole (drive magnetic pole cp1) of the magnet rotor 31 to make it easier to understand the positional relationship between the magnet rotor 31 and the stator 60 (A-phase stator 61, B-phase stator 62).

[0072] When pulses P are input to the stepping motor 66 in ascending order (P[1] to P[8]), the magnet rotor 31 rotates in the second direction (counterclockwise in Figures 14 to 21).

[0073] When pulses P are input to the stepping motor 66 in descending order (P[8] to P[1]), the magnet rotor 31 rotates in the first direction (clockwise in Figures 14 to 21).

[0074] When the magnet rotor 31 is rotating in the first and second directions, the magnetic sensor 91 outputs H signals and L signals alternately in accordance with the detected magnetic poles dp1 to dp6. The H and L signals corresponding to the detected magnetic poles dp1 to dp6 are the signal portions in the output signal K that correspond to the detected magnetic poles dp1 to dp6. Since the detected magnetic poles dp1 to dp6 differ from each other in at least one of their polarity and circumferential length, the signal portions in the output signal K that correspond to the detected magnetic poles dp1 to dp6 differ from each other in at least one of their signal value and length.

[0075] The magnetic sensor 91 outputs an H signal corresponding to the detected magnetic pole dp1, and the length of the H signal corresponds to approximately three pulses P. The magnetic sensor 91 outputs an L signal corresponding to the detected magnetic pole dp2, and the length of the L signal corresponds to approximately 8 pulses P. The magnetic sensor 91 outputs an H signal corresponding to the detected magnetic pole dp3, and the length of the H signal corresponds to approximately 12 pulses P. The magnetic sensor 91 outputs an L signal corresponding to the detected magnetic pole dp4, and the length of the L signal corresponds to approximately 13 pulses P. The magnetic sensor 91 outputs an H signal corresponding to the detected magnetic pole dp5, and the length of the H signal corresponds to approximately 27 pulses P. The magnetic sensor 91 outputs an L signal corresponding to the detected magnetic pole dp6, and the length of the L signal corresponds to approximately 33 pulses P.

[0076] Figure 22A shows an example of the output signal K of the magnetic sensor 91 when the magnet rotor 31 is rotating at a constant speed in the first direction. In the waveform of the output signal K corresponding to one rotation (360 degrees) of the magnet rotor 31, the length of the H signal and the length of the L signal gradually increase. This waveform is repeated each time the magnet rotor 31 rotates.

[0077] Figure 22B shows an example of the output signal K of the magnetic sensor 91 when the magnet rotor 31 is rotating at a constant speed in the second direction. In the waveform of the output signal K corresponding to one rotation (360 degrees) of the magnet rotor 31, the lengths of the H signal and the L signal gradually shorten. This waveform is repeated each time the magnet rotor 31 rotates.

[0078] The magnetic sensor 91 outputs an output signal K corresponding to the rotation direction of the detection rotor 312. That is, the waveform of the output signal K when the detection rotor 312 rotates in the first direction is different from the waveform of the output signal K when it rotates in the second direction. Therefore, the control device 100 can detect the rotation direction of the magnet rotor 31 based on the output signal K of the magnetic sensor 91.

[0079] Furthermore, the positions (angles) of the boundaries between the detected magnetic poles dp1 to dp6 (N pole, S pole) on the outer surface of the detection rotor 312 are predetermined. When the boundary passes a position radially aligned with the magnetic sensor 91, the output signal K changes from an H signal to an L signal, or from an L signal to an H signal. Therefore, the control device 100 can obtain the rotation angle of the magnet rotor 31 based on the output signal K of the magnetic sensor 91. In particular, the control device 100 can obtain the absolute rotation angle (0 to 360 degrees) of the magnet rotor 31 at the time of the second change based on the signal value and length of the output signal K from the first change to the second change following the first change. The control device 100 may use the absolute rotation angle of the magnet rotor 31 to calibrate the rotation angle (variable) of the magnet rotor 31 used for control.

[0080] Next, the output signal K of the magnetic sensor 91 when the magnet rotor 31 is rotated in the first direction in the electric valve device 1 will be explained with reference to Figures 23 to 25. Figure 23 is a diagram showing an example of the pulse P input to the stepping motor 66, the rotation direction and rotation angle of the magnet rotor 31, and the output signal K at times T1 to T113. Figures 24 and 25 are diagrams illustrating the movement of the magnet rotor 31 when its rotation in the first direction is restricted. In Figures 24 and 25, marks (black circles) are placed on the reference pole teeth 61a and the drive magnetic pole cp1 (S pole) of the reference drive rotor 311 to make it easier to understand the positional relationship between the magnet rotor 31 and the stator 60 (A-phase stator 61, B-phase stator 62). In Figures 24 and 25, the right direction is the first direction, and the left direction is the second direction. Figures 24A to 24D and 25A to 25D correspond to the time intervals T105 to T113 in Figure 23.

[0081] When the control device 100 repeatedly inputs pulses P in descending order to the stepping motor 66 at regular time intervals (times T1 to T113), the magnet rotor 31 rotates in the first direction by step angles. At time T1, when pulse P[1] is input to the stepping motor 66, the rotation angle of the magnet rotor 31 becomes 390 degrees.

[0082] The magnetic sensor 91 outputs an L signal when a pulse P is input to the stepping motor 66 between times T1 and T7 (rotation angle: 390.00 to 367.50 degrees). When a pulse P is input to the stepping motor 66 at time T8, the magnet rotor 31 rotates in the first direction, and the output signal K switches from an L signal to an H signal when the magnet rotor 31 passes the position where the rotation angle is 365 degrees.

[0083] When a pulse P is input to the stepping motor 66 between times T8 and T10 (rotation angle: 363.75 to 356.25 degrees), the magnetic sensor 91 outputs an H signal. The H signal between times T8 and T10 corresponds to the detected magnetic pole dp1. When a pulse P is input to the stepping motor 66 at time T11, the magnet rotor 31 rotates in the first direction, and the output signal K switches from an H signal to an L signal at the moment the magnet rotor 31 passes the position where the rotation angle is 355 degrees.

[0084] When a pulse P is input to the stepping motor 66 between times T11 and T18 (rotation angle: 352.50 to 326.25 degrees), the magnetic sensor 91 outputs an L signal. The L signal between times T11 and T18 corresponds to the detected magnetic pole dp2. When a pulse P is input to the stepping motor 66 at time T19, the magnet rotor 31 rotates in the first direction, and the output signal K switches from an L signal to an H signal at the moment the magnet rotor 31 passes the position where the rotation angle is 325 degrees.

[0085] When a pulse P is input to the stepping motor 66 between times T19 and T30 (rotation angle: 322.50 to 281.25 degrees), the magnetic sensor 91 outputs an H signal. The H signal between times T19 and T30 corresponds to the detected magnetic pole dp3. When a pulse P is input to the stepping motor 66 at time T31, the magnet rotor 31 rotates in the first direction, and the output signal K switches from an H signal to an L signal at the moment the magnet rotor 31 passes the position where the rotation angle is 280 degrees.

[0086] When a pulse P is input to the stepping motor 66 between times T31 and T43 (rotation angle: 277.50 to 232.50 degrees), the magnetic sensor 91 outputs an L signal. The L signal between times T31 and T43 corresponds to the detected magnetic pole dp4. When a pulse P is input to the stepping motor 66 at time T44, the magnet rotor 31 rotates in the first direction, and the output signal K switches from an L signal to an H signal at the moment the magnet rotor 31 passes the position where the rotation angle is 230 degrees.

[0087] When a pulse P is input to the stepping motor 66 between times T44 and T70 (rotation angle: 228.75 to 131.25 degrees), the magnetic sensor 91 outputs an H signal. The H signal between times T44 and T70 corresponds to the detected magnetic pole dp5. When a pulse P is input to the stepping motor 66 at time T71, the magnet rotor 31 rotates in the first direction, and the output signal K switches from an H signal to an L signal at the moment the magnet rotor 31 passes the position where the rotation angle is 130 degrees.

[0088] When a pulse P is input to the stepping motor 66 between times T71 and T103 (rotation angle: 127.50 to 7.50 degrees), the magnetic sensor 91 outputs an L signal. The L signal between times T71 and T103 corresponds to the detected magnetic pole dp6. When a pulse P is input to the stepping motor 66 at time T104, the magnet rotor 31 rotates in the first direction, and the output signal K switches from an L signal to an H signal when the magnet rotor 31 passes a position where the rotation angle is 5 degrees.

[0089] Then, when pulse P[1] is input to the stepping motor 66 at time T105, the magnet rotor 31 is positioned at the reference position Rx, and the rotation angle of the magnet rotor 31 becomes 0 degrees. The magnetic sensor 91 outputs an H signal at time T105. The H signal at time T105 corresponds to the detected magnetic pole dp1. As shown in Figure 24A, when the magnet rotor 31 is positioned at the reference position Rx, the movable stopper 32s comes into contact with the fixed stopper 33s, restricting the rotation of the magnet rotor 31 in the first direction.

[0090] At times T106, T107, T108, and T109, when pulses P[8], P[7], P[6], and P[5] are input to the stepping motor 66, the magnet rotor 31 does not rotate, as shown in Figures 24B, 24C, 24D, and 25A. Therefore, after the input of pulse P at times T106, T107, T108, and T109, the rotation angle of the magnet rotor 31 is 0 degrees, and the magnetic sensor 91 outputs an H signal.

[0091] When pulse P[4] is input to the stepping motor 66 at time T110, as shown in Figure 25B, the magnet rotor 31 rotates in the second direction by an angle three times the step angle, and the output signal K switches from an H signal to an L signal when the magnet rotor 31 passes the position where the rotation angle is 5 degrees. The magnet rotor 31 is positioned at the same position as at time T102 (rotation angle: 11.25 degrees). Time T102 is the time when pulse P[4] was input immediately before time T110. After pulse P input at time T110, the magnetic sensor 91 outputs an L signal. The L signal immediately after time T110 corresponds to the detected magnetic pole dp6.

[0092] At times T111, T112, and T113, when pulses P[3], P[2], and P[1] are input to the stepping motor 66, the magnet rotor 31 rotates in the first direction by step angles, as shown in Figures 25C, 25D, and 24A. After pulse P is input at time T111 (rotation angle: 7.50 degrees), the magnetic sensor 91 outputs an L signal. After pulse P is input at time T112 (rotation angle: 3.75 degrees), the magnetic sensor 91 outputs an H signal. After pulse P is input at time T113 (rotation angle: 0.00 degrees), the magnetic sensor 91 outputs an H signal. Between times T111 and T113, when the magnet rotor 31 passes the position where the rotation angle is 5 degrees, the output signal K switches from an L signal to an H signal.

[0093] From this point onward, in response to the input pulses P[8] to P[1], the output signal K repeats the same changes as at times T106 to T113. That is, the magnetic sensor 91 alternates radially with the detected magnetic poles dp1 and dp6, and repeatedly outputs H signals corresponding to approximately 6 pulses P and L signals corresponding to approximately 2 pulses P. The lengths of these H and L signals are different from the lengths of the signal portions (H signals and L signals) corresponding to the detected magnetic poles dp1 to dp6.

[0094] When the magnet rotor 31 is rotating normally, the output signal K of the magnetic sensor 91 contains only H and L signals corresponding to the detected magnetic poles dp1 to dp6. When the rotation of the magnet rotor 31 in the first direction is restricted, an L signal corresponding to the detected magnetic pole dp6 (times T71 to T103) is followed by an H signal corresponding to the detected magnetic pole dp1 and an H signal of a different length (times T104 to T109). In other words, when the rotation of the magnet rotor 31 in the first direction is restricted, the output of the signal portion corresponding to the detected magnetic pole dp1 is not completed, and the signal portion corresponding to the detected magnetic pole dp1 does not appear in the output signal K. Therefore, the control device 100 can detect that the magnet rotor 31 has been positioned at the reference position Rx by determining whether or not the output signal K contains the signal portion corresponding to the detected magnetic pole dp1.

[0095] Next, an example of the operation of the control device 100 (the operation of positioning the magnet rotor 31 at the reference position Rx) will be explained with reference to the flowchart in Figure 26.

[0096] The control device 100 (specifically the CPU 121) inputs pulses P in descending order to the stepping motor 66 (S110). The magnet rotor 31 rotates in the first direction. The control device 100 acquires the output signal K from the magnetic sensor 91 (S120). When the output signal K contains a signal portion corresponding to the detected magnetic pole dp1 (reference detected magnetic pole) (Y in S130), the control device 100 determines that the magnet rotor 31 is rotating in the first direction and inputs the next pulse P (returns to S110). When the output signal K does not contain a signal portion corresponding to the detected magnetic pole dp1 (N in S130), the control device 100 determines that the magnet rotor 31 is not rotating and detects that the rotation of the magnet rotor 31 in the first direction has been restricted (S140). As a result, the control device 100 terminates its operation, assuming that the magnet rotor 31 is positioned at the reference position Rx.

[0097] The control device 100 can detect, based on the output signal K from the magnetic sensor 91, that the rotation of the magnet rotor 31 in the first direction is restricted by the stopper mechanism 38. Furthermore, based on the output signal K from the magnetic sensor 91, the control device 100 can also detect, for example, that the rotation of the magnet rotor 31 is restricted by foreign matter mixed in the refrigerant.

[0098] Furthermore, the control device 100 detects the rotation direction of the magnet rotor 31 based on the order in which the signal portions corresponding to the detected magnetic poles dp1 to dp6 appear in the output signal K.

[0099] Furthermore, the control device 100 obtains the rotation angle of the magnet rotor 31 based on the timing at which the H signal and L signal switch in the output signal K (actual rotation angle). The control device 100 calculates the rotation angle of the magnet rotor 31 based on the pulse P input to the stepping motor (calculated rotation angle). Based on the actual rotation angle and the calculated rotation angle, the control device 100 detects step loss in the stepping motor 66.

[0100] The electric valve device 1 according to this embodiment includes an electric valve 5 and a control device 100. The electric valve 5 includes a valve body 10 having a valve port 17, a stepping motor 66 having a drive rotor 311 and a stator 60, a valve body 40 that moves relative to the valve port 17 in accordance with the rotation of the drive rotor 311, a detection rotor 312 having a cylindrical outer surface and connected coaxially with the drive rotor 311, and a magnetic sensor 91 radially aligned with the detection rotor 312. The output signal K of the magnetic sensor 91 is a binary signal corresponding to the direction of the magnetic field detected by the magnetic sensor 91. The detection rotor 312 has a plurality of detection magnetic poles dp1 to dp6. The magnetic sensor 91 detects the magnetic fields of the plurality of detection magnetic poles dp1 to dp6. The plurality of detection magnetic poles dp1 to dp6 include a plurality of N poles and a plurality of S poles, and are arranged on the outer surface of the detection rotor 312 so that their polarities alternate. The plurality of N poles have different circumferential lengths. Multiple south poles have different circumferential lengths.

[0101] According to the electric valve 5, when the detection rotor 312 rotates, multiple detection magnetic poles dp1 to dp6 are aligned radially with the magnetic sensor 91 in sequence. The magnetic fields of the multiple detection magnetic poles dp1 to dp6 are detected sequentially by the magnetic sensor 91. The output signal K of the magnetic sensor 91 includes signal portions (H signal, L signal) corresponding to the multiple detection magnetic poles dp1 to dp6. Since the multiple detection magnetic poles dp1 to dp6 differ from each other in at least one of their polarity and circumferential length, the signal portions differ from each other in at least one of their signal value and length. The order in which these signal portions appear (i.e., the waveform of the output signal K) when the detection rotor 312 rotates in a first direction is different from the order in which these signal portions appear when the detection rotor 312 rotates in a second direction. Therefore, the rotation direction of the drive rotor 311 can be detected based on the output signal K of one magnetic sensor 91.

[0102] Furthermore, the boundary positions (angles) of the detection magnetic poles dp1 to dp6 (N pole, S pole) on the outer surface of the detection rotor 312 are predetermined. When the boundary passes a position radially aligned with the magnetic sensor 91, the output signal K changes from an H signal to an L signal, or from an L signal to an H signal. Therefore, the rotation angle of the magnet rotor 31 can be obtained based on the output signal K of the magnetic sensor 91.

[0103] Furthermore, multiple detection magnetic poles dp1 to dp6 are arranged in order of their circumferential length. In this way, the length of the signal portion corresponding to the detection magnetic poles dp1 to dp6 in the output signal K of the magnetic sensor 91 gradually increases or decreases depending on the rotation direction of the detection rotor 312. Therefore, the rotation direction of the drive rotor 311 can be detected more easily based on the output signal K of the magnetic sensor 91.

[0104] Furthermore, the electric valve 5 has a stopper mechanism 38 that restricts the rotation of the drive rotor 311 in the first direction when the drive rotor 311 is in the reference position Rx. When the drive rotor 311 is in the reference position Rx, one of the multiple detection magnetic poles dp1 to dp6, the detection magnetic pole dp1 (reference detection magnetic pole), is aligned radially with the magnetic sensor 91, and the magnetic sensor 91 detects the magnetic field of the detection magnetic pole dp1. In this way, when the rotation of the drive rotor 311 in the first direction is restricted at the reference position Rx, the output of the signal portion (H signal) corresponding to the detection magnetic pole dp1 in the output signal K of the magnetic sensor 91 is not completed. As a result, when the signal portion corresponding to the detection magnetic pole dp1 is not included in the output signal K of the magnetic sensor 91, it can be estimated that the drive rotor 311 is in the reference position Rx. Therefore, it is possible to detect that the drive rotor 311 is in the reference position Rx based on the output signal K of the magnetic sensor 91.

[0105] Furthermore, the reference detection pole is the detection pole dp1 (minimum detection pole) which has the shortest circumferential length among the multiple detection poles dp1 to dp6. This allows for relatively quick determination of whether the output of the signal portion corresponding to the detection pole dp1 in the output signal K of the magnetic sensor 91 has been completed. Therefore, it is possible to detect relatively quickly that the drive rotor 311 is at the reference position Rx based on the output signal K of the magnetic sensor 91.

[0106] Furthermore, the drive rotor 311 has a cylindrical outer surface and a plurality of drive magnetic poles cp. The plurality of drive magnetic poles cp include a plurality of N poles and a plurality of S poles, and are arranged circumferentially on the outer surface of the drive rotor 311 so that their polarities alternate. Each of the plurality of drive magnetic poles cp has the same circumferential length. The circumferential length of the detected magnetic pole dp1 is less than or equal to the circumferential length of the plurality of drive magnetic poles cp. A line E1 passing through the circumferential center of the detected magnetic pole dp1 passes through the circumferential center of one of the plurality of drive magnetic poles cp, cp1. In this way, it is possible to determine more quickly whether the output of the signal portion corresponding to the detected magnetic pole dp1 in the output signal K of the magnetic sensor 91 has been completed. Therefore, it is possible to detect more quickly that the drive rotor 311 is at the reference position Rx based on the output signal K of the magnetic sensor 91.

[0107] Furthermore, it is preferable that the central angle β1 corresponding to the circumferential length of the detected magnetic pole dp1 is less than twice the step angle of the stepping motor 66. By doing so, the signal portion of the output signal K of the magnetic sensor 91 corresponding to the detected magnetic pole dp1 is approximately the length of one pulse P, and it is possible to determine more quickly whether or not the output of the signal portion of the output signal K of the magnetic sensor 91 corresponding to the detected magnetic pole dp1 has been completed. As a result, it is possible to detect more quickly that the drive rotor 311 is at the reference position Rx based on the output signal K of the magnetic sensor 91.

[0108] Furthermore, the control device 100 inputs a pulse P to the stepping motor 66 so that the drive rotor 311 rotates. The control device 100 obtains the rotation direction of the drive rotor 311 based on the output signal K of the magnetic sensor 91. The control device 100 can detect the rotation direction of the magnet rotor 31 of the electric valve 5 with simple control.

[0109] Furthermore, the control device 100 inputs a pulse P to the stepping motor 66 so that the drive rotor 311 rotates. The control device 100 detects stepping out of step in the stepping motor 66 based on the rotation angle of the magnet rotor 31 obtained based on the output signal K of the magnetic sensor 91 and the rotation angle of the magnet rotor 31 corresponding to the pulse P input to the stepping motor 66. The control device 100 can detect stepping out of step in the stepping motor 66 of the electric valve 5 with simple control.

[0110] Furthermore, in the operation of positioning the drive rotor 311 at the reference position Rx, the control device 100 inputs a pulse P to the stepping motor 66 so that the drive rotor 311 rotates in the first direction. When the control device 100 detects that the output signal K of the magnetic sensor 91 does not include a signal portion corresponding to the detected magnetic pole dp1, it stops inputting the pulse P to the stepping motor 66. The control device 100 can stop the stepping motor 66 after positioning the drive rotor 311 at the reference position Rx with simple control.

[0111] According to the electric valve device 1, an inexpensive electric valve having only one magnetic sensor 91 can detect the rotation direction, rotation angle, and step loss of the stepping motor 66 (magnet rotor 31).

[0112] In this embodiment, the electric valve device 1 has a magnetic rotor 31. Six detection magnetic poles dp1 to dp6 are provided on the outer circumferential surface of the detection rotor 312 of the magnetic rotor 31, extending over the entire circumferential direction. The electric valve device 1 may have a magnetic rotor 31A as shown in Figure 27 or a magnetic rotor 31B as shown in Figure 28 instead of the magnetic rotor 31.

[0113] Figure 27 shows the configuration of a magnet rotor 31A, which is a first modified example of the magnet rotor 31 of the electric valve device 1 according to this embodiment. Figure 27A is a bottom view of the magnet rotor 31A. Figure 27B is a top view of the magnet rotor 31A.

[0114] The magnet rotor 31A integrally includes a drive rotor 311 and a detection rotor 312A. The drive rotor 311 of the magnet rotor 31A has the same configuration as the drive rotor 311 of the magnet rotor 31.

[0115] The detection rotor 312A is connected to the upper end of the drive rotor 311. The detection rotor 312A may also be connected to the lower end of the drive rotor 311. The detection rotor 312A is coaxially positioned with the drive rotor 311. The detection rotor 312A rotates together with the drive rotor 311. The outer diameter of the detection rotor 312A is the same as the outer diameter of the drive rotor 311. The detection rotor 312A has a cylindrical outer surface.

[0116] The detection rotor 312A has multiple detection magnetic poles dp1 to dp3. The detection magnetic poles dp1 to dp3 are arranged on the outer circumferential surface of the detection rotor 312A. Detection magnetic poles dp1 and dp3 are north poles. Detection magnetic pole dp2 is a south pole. The detection magnetic poles dp1 to dp3 are arranged circumferentially on the outer circumferential surface of the detection rotor 312A so that their polarities alternate. The detection magnetic poles dp1 to dp3 of the detection rotor 312A have the same configuration as the detection magnetic poles dp1 to dp3 of the detection rotor 312 of the magnet rotor 31.

[0117] The detection rotor 312A has an unmagnetized portion NP. The unmagnetized portion NP is located between detection pole dp1 and detection pole dp3 on the outer circumferential surface of the detection rotor 312A. The unmagnetized portion NP is the unmagnetized part on the outer circumferential surface of the detection rotor 312A. No magnetic poles are provided in the unmagnetized portion NP.

[0118] The detection rotor 312A has three detection poles (detection poles dp1 to dp3) and one unmagnetized portion NP. The detection poles dp1 to dp3 and the unmagnetized portion NP are arranged circumferentially on the outer surface of the detection rotor 312A. The central angle βn corresponding to the circumferential length of the unmagnetized portion NP is 275 degrees.

[0119] The detection rotor 312A has the same configuration as the detection rotor 312 of the magnet rotor 31, except that it has one unmagnetized portion NP instead of detection magnetic poles dp4 to dp6.

[0120] As the detection rotor 312A rotates together with the drive rotor 311, the magnetic fields of multiple detection poles dp1 to dp3 are sequentially detected by the magnetic sensor 91. The output signal K of the magnetic sensor 91 includes signal portions corresponding to the detection poles dp1 to dp3, which have different circumferential lengths. The order in which these signal portions appear when the detection rotor 312A rotates in a first direction is different from the order in which they appear when the detection rotor 312A rotates in a second direction. Therefore, the control device 100 can detect the rotation direction of the drive rotor 311 based on the output signal K of the magnetic sensor 91.

[0121] Figure 28 shows the configuration of a magnet rotor 31B, which is a second modified example of the magnet rotor 31 of the electric valve device 1 according to this embodiment. Figure 28A is a bottom view of the magnet rotor 31B. Figure 28B is a top view of the magnet rotor 31B.

[0122] The magnet rotor 31B integrally includes a drive rotor 311 and a detection rotor 312B. The drive rotor 311 of the magnet rotor 31B has the same configuration as the drive rotor 311 of the magnet rotor 31.

[0123] The detection rotor 312B is connected to the upper end of the drive rotor 311. The detection rotor 312B may also be connected to the lower end of the drive rotor 311. The detection rotor 312B is coaxially positioned with the drive rotor 311. The detection rotor 312B rotates together with the drive rotor 311. The outer diameter of the detection rotor 312B is the same as the outer diameter of the drive rotor 311. The detection rotor 312B has a cylindrical outer surface.

[0124] The detection rotor 312B has multiple detection magnetic poles dp1 to dp6. The detection magnetic poles dp1 to dp6 are arranged on the outer circumferential surface of the detection rotor 312B. Detection magnetic poles dp1, dp3, and dp5 are north poles. Detection magnetic poles dp2, dp4, and dp6 are south poles. The detection magnetic poles dp1 to dp6 are arranged circumferentially on the outer circumferential surface of the detection rotor 312A so that their polarities alternate.

[0125] The central angle β1 corresponding to the circumferential length of the detected magnetic pole dp1 is 10 degrees. The central angle β2 corresponding to the circumferential length of the detected magnetic pole dp2 is 80 degrees. The central angle β3 corresponding to the circumferential length of the detected magnetic pole dp3 is 30 degrees. The central angle β4 corresponding to the circumferential length of the detected magnetic pole dp4 is 80 degrees. The central angle β5 corresponding to the circumferential length of the detected magnetic pole dp5 is 80 degrees. The center angle β6 corresponding to the circumferential length of the detection magnetic pole dp6 is 80 degrees.

[0126] The circumferential lengths of detection magnetic poles dp1, dp3, and dp5 are different from each other. When the circumferential lengths of detection magnetic poles dp1, dp3, and dp5 are denoted as B1, B3, and B5 respectively, the relation B1 < B3 < B5 holds. The circumferential lengths of detection magnetic poles dp2, dp4, and dp6 are the same. When the circumferential lengths of detection magnetic poles dp2, dp4, and dp6 are denoted as B2, B4, and B6 respectively, the relation B2 = B4 = B6 holds. Additionally, the circumferential length of detection magnetic pole dp5 is the same as the circumferential length of detection magnetic pole dp2.

[0127] Note that, instead of the detection magnetic poles dp2, dp4, and dp6, the detection rotor 312B may have three non-magnetized portions NP.

[0128] When the detection rotor 312B rotates together with the drive rotor 311, the magnetic fields of the plurality of detection magnetic poles dp1, dp3, and dp5 are sequentially detected by the magnetic sensor 91. The output signal K of the magnetic sensor 91 includes signal portions corresponding to the detection magnetic poles dp1, dp3, and dp5 which have different circumferential lengths from each other. The appearance order of the signal portions when the detection rotor 312B rotates in a first direction is different from the appearance order of the signal portions when the detection rotor 312B rotates in a second direction. Therefore, the control device 100 can detect the rotation direction of the drive rotor 311 based on the output signal K of the magnetic sensor 91.

[0129] It should be noted that the detection rotor according to the present invention only needs to have at least three detection magnetic poles with circumferential lengths different from each other. It is preferable that the detection magnetic poles differ from each other in at least one of polarity and circumferential length. Portions other than the detection magnetic poles on the outer circumferential surface of the detection rotor may be non-magnetized portions.

[0130] Also in the motor-operated valve device 1 having the magnet rotor 31A or the magnet rotor 31B, the same (including substantially the same) effects as those of the present embodiment can be achieved.

[0131] In this embodiment, the control device 100 controls the electric valve 5, but the air conditioner control device 410 may directly control the electric valve 5. In this case, the air conditioner control device 410 is the electric valve control device.

[0132] In this specification, terms describing the shape of a member, such as "cylinder" or "column," are also used to refer to members that substantially have the shape of that term. For example, "cylindrical member" includes both cylindrical members and substantially cylindrical members.

[0133] Although embodiments of the present invention have been described above, the present invention is not limited to these examples. Additions, deletions, and design modifications of components, or combinations of features of the embodiments as appropriate by those skilled in the art, are also included within the scope of the present invention, as long as they do not contradict the spirit of the invention. [Explanation of Symbols]

[0134] 1…Electric valve device, 5…Electric valve, 10…Valve body, 11…Body member, 11a…Mounting hole, 11b…Top surface, 12…Support member, 12a…Matching hole, 13…Connecting member, 14…Valve chamber, 15, 16…Flow path, 17…Valve port, 18…Valve seat, 20…Can, 30…Drive mechanism, 31, 31A, 31B…Magnet rotor, 311…Drive rotor, 312, 312A, 312B…Detection rotor, 32…Valve shaft holder -, 32c...female thread, 32s...movable stopper, 33...guide bush, 33a...base, 33b...support part, 33c...male thread, 33s...fixed stopper, 35...support ring, 36...push nut, 37...valve closing spring, 38...stopper mechanism, 40...valve body, 41...first shaft part, 42...second shaft part, 43...valve part, 44...step part, 50...stator unit, 60...stator, 61...A-phase stator, 61a, 61b...pole teeth, 61c...coil, 62...B-phase stator, 62a, 62b...pole teeth, 62c...coil, 65...terminal, 66...stepping motor, 70...housing, 74...inner space, 75...board space, 76...partition, 80...case, 80a...opening, 83...connector, 85...space, 87...boss, 90...sensor board, 90a...first end, 90b...second end, 93...connection terminal, 9 5...Substrate support member, 97...Cylindrical part, 91...Magnetic sensor, 100...Electric valve control device, 110...Control board, 112...Through hole, 120...Microcomputer, 121...CPU, 122...Non-volatile memory, 123...Motor driver, 124...Working memory, 125...Communication module, cp, cp1...Drive magnetic pole, dp1~dp6...Detection magnetic pole, NP...Unmagnetized part, L...Axis, K...Output signal

Claims

1. An electric valve comprising: a valve body having a valve port; a stepping motor having a drive rotor and a stator; a valve body that moves relative to the valve port in accordance with the rotation of the drive rotor; a detection rotor connected coaxially with the drive rotor; and a magnetic sensor, The electric valve has only one of the magnetic sensors, The detection rotor has a cylindrical outer surface on which a plurality of detection magnetic poles are arranged in the circumferential direction, The magnetic sensor detects the magnetic fields of the plurality of detection poles, An electric valve characterized in that at least three of the plurality of detection magnetic poles have different circumferential lengths.

2. The electric valve according to claim 1, wherein the plurality of detection magnetic poles are arranged circumferentially on the outer surface of the detection rotor such that their polarities alternate, and at least one of their polarities and circumferential lengths is different from one another.

3. The electric valve according to claim 2, wherein the plurality of detection magnetic poles are arranged in order of circumferential length.

4. The electric valve further includes a stopper mechanism that restricts the rotation of the drive rotor in a first direction when the drive rotor is in a reference position. The electric valve according to claim 1 or 2, wherein when the drive rotor is in the reference position, the magnetic sensor detects the magnetic field of one of the plurality of detection magnetic poles (hereinafter referred to as the "reference detection magnetic pole").

5. The electric valve according to claim 4, wherein the reference detection pole is a detection pole having the minimum circumferential length among the plurality of detection poles.

6. The drive rotor has a cylindrical outer surface and a plurality of drive magnetic poles, The plurality of drive magnetic poles are arranged circumferentially on the outer surface of the drive rotor such that their polarities alternate, and each has the same circumferential length. The circumferential length of the reference detection magnetic pole is less than or equal to the circumferential length of the drive magnetic pole. The electric valve according to claim 5, wherein the straight line passing through the circumferential center of the reference detection magnetic pole passes through the circumferential center of one of the plurality of drive magnetic poles.

7. The electric valve according to claim 6, wherein the central angle corresponding to the circumferential length of the reference detection magnetic pole is less than twice the step angle of the stepping motor.

8. An electric valve device comprising an electric valve according to claim 1 and an electric valve control device for controlling the electric valve, The electric valve control device acquires the rotation direction of the drive rotor based on the order in which the signal portions corresponding to the at least three detected magnetic poles included in the output signal of the magnetic sensor appear.

9. The electric valve control device, A pulse is input to the stepping motor so that the drive rotor rotates. The electric valve device according to claim 8, which detects stepping out of step of the stepping motor based on the rotation angle of the drive rotor obtained based on the output signal of the magnetic sensor and the rotation angle of the drive rotor corresponding to the pulse input to the stepping motor.

10. An electric valve device comprising an electric valve according to claim 4 and an electric valve control device for controlling the electric valve, In the operation of the electric valve control device to position the drive rotor at the reference position, A pulse is input to the stepping motor so that the drive rotor rotates in the first direction. An electric valve device that stops the input of pulses to the stepping motor when the output signal of the magnetic sensor does not include a signal portion corresponding to the reference detected magnetic pole.

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