Electric valve control device, electric valve device, and method for controlling an electric valve

Abstract

To provide a motor valve control device capable of reducing power consumption of a motor valve, a motor valve device having the motor valve control device, and a method for controlling a motor valve.SOLUTION: A motor valve control device 70 acquires a voltage generated in a stator 60 by the rotation of a rotor 41, and determines the relation between a rotation load and the magnitude of a drive current supplied to the stator 60 based on that voltage. When the motor valve control device 70 determines that the magnitude of the drive current is appropriate for the rotation load, it maintains the magnitude of the drive current, when it determines that the magnitude of the drive current is large for the rotation load, it reduces the magnitude of the drive current, and when it determines that the magnitude of the drive current is small for the rotation load, it increases the magnitude of the drive current.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to an electrically operated valve control device, an electrically operated valve device having the electrically operated valve control device, and a method for controlling a electrically operated valve. [Background technology]

[0002] Patent Document 1 discloses an example of a conventional motor-operated valve. Such a motor-operated valve is incorporated into the refrigeration cycle of an air conditioner. The motor-operated valve has a valve body and a stepping motor for moving the valve body. The stepping motor has a rotor and a stator. When a pulse is input to the stepping motor, the rotor rotates. Specifically, when a driving current corresponding to the pulse is supplied to the coil of the stator, the rotor rotates. When the rotor rotates, the valve body moves. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2019 / 130928 Summary of the Invention [Problem to be solved by the invention]

[0004] The rotational load of the rotor varies according to the force applied to the valve disc. To ensure that the rotor rotates reliably, the magnitude of the drive current supplied to the stator coil is set to match a relatively large rotational load. Therefore, when the rotational load is small, the drive current is large relative to the rotational load, and the stepping motor consumes extra power.

[0005] SUMMARY OF THE PRESENT DISCLOSURE In view of the above, an object of the present invention is to provide a motor-operated valve control device capable of reducing the power consumption of a motor-operated valve, a motor-operated valve device having the motor-operated valve control device, and a method for controlling the motor-operated valve. [Means for solving the problem]

[0006] The inventors used multiple motor-operated valves to measure the voltage generated in the stator by the rotation of the rotor (the voltage electromagnetically induced in the stator) and thoroughly investigated the measurement results. As a result, the inventors found that there is a difference between the voltage when the magnitude of the drive current is appropriate for the rotation load of the rotor and the voltage when the magnitude of the drive current is inappropriate for the rotation load of the rotor, and arrived at the present invention.

[0007] In order to achieve the above object, an electric valve control device according to one aspect of the present invention comprises: An electric valve control device for controlling an electric valve having a valve body having a valve port, a stepping motor having a rotor and a stator, and a valve body that moves relative to the valve port when the rotor rotates, a rotation control unit that supplies a drive current to the stator to rotate the rotor; an acquisition unit that acquires a voltage generated in the stator due to rotation of the rotor; a determination unit that determines a relationship between a rotation load of the rotor and a magnitude of the drive current based on the voltage acquired by the acquisition unit, The rotation control unit is When the determination unit determines that the magnitude of the drive current is appropriate for the rotation load of the rotor, the magnitude of the drive current is maintained; When the determination unit determines that the magnitude of the drive current is large relative to the rotation load of the rotor, the magnitude of the drive current is reduced; When the determining unit determines that the magnitude of the drive current is small relative to the rotation load of the rotor, the magnitude of the drive current is increased.

[0008] In the present invention, It is preferable that the determination unit determines the relationship based on a degree of difference between the waveform of the voltage acquired by the acquisition unit and a reference waveform of the voltage.

[0009] In the present invention, It is preferable that the determination section calculates a dissimilarity index value indicating a degree of difference between the waveform of the voltage and a reference waveform of the voltage, and determines the relationship based on a result of comparing the dissimilarity index value with a determination value.

[0010] In the present invention, the reference waveform of the voltage is a data table in which a time is associated with a reference voltage at the time, The acquisition unit acquires the voltage in time series, The determination unit, calculating an intermediate value that is a squared value of a difference between the voltage acquired by the acquisition unit at an acquisition time and the reference voltage associated with the time corresponding to the acquisition time in the data table; It is preferable that the dissimilarity index value is calculated by adding up a plurality of the intermediate values ​​calculated using the voltages.

[0011] In order to achieve the above object, a motor-operated valve control device according to another aspect of the present invention comprises: An electric valve control device for controlling an electric valve having a valve body having a valve port, a stepping motor having a rotor and a stator, and a valve body that moves relative to the valve port when the rotor rotates, a rotation control unit that supplies a drive current to the stator to rotate the rotor; an acquisition unit that acquires a current generated in the stator due to rotation of the rotor; a determination unit that determines a relationship between a rotation load of the rotor and a magnitude of the drive current based on the current acquired by the acquisition unit, The rotation control unit is When the determination unit determines that the magnitude of the drive current is appropriate for the rotation load of the rotor, the magnitude of the drive current is maintained; When the determination unit determines that the magnitude of the drive current is large relative to the rotation load of the rotor, the magnitude of the drive current is reduced; When the determining unit determines that the magnitude of the drive current is small relative to the rotation load of the rotor, the magnitude of the drive current is increased.

[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 control device and the motor-operated valve.

[0013] In order to achieve the above object, a control method for a motor-operated valve according to another aspect of the present invention includes the steps of: A method for controlling an electrically operated valve having a valve body having a valve port, a stepping motor having a rotor and a stator, and a valve body that moves relative to the valve port when the rotor rotates, comprising: Supplying a driving current to the stator to rotate the rotor; Acquire a voltage generated in the stator due to rotation of the rotor; determining a relationship between a rotation load of the rotor and a magnitude of the drive current based on the voltage; When it is determined that the magnitude of the drive current is appropriate for the rotation load of the rotor, the magnitude of the drive current is maintained; When it is determined that the magnitude of the drive current is large relative to the rotation load of the rotor, the magnitude of the drive current is reduced; When it is determined that the magnitude of the drive current is small relative to the rotation load of the rotor, the magnitude of the drive current is increased.

[0014] In order to achieve the above object, a control method for a motor-operated valve according to another aspect of the present invention includes the steps of: A method for controlling an electrically operated valve having a valve body having a valve port, a stepping motor having a rotor and a stator, and a valve body that moves relative to the valve port when the rotor rotates, comprising: Supplying a driving current to the stator to rotate the rotor; Acquire a current generated in the stator due to the rotation of the rotor; determining a relationship between a rotation load of the rotor and a magnitude of the drive current based on the current; When it is determined that the magnitude of the drive current is appropriate for the rotation load of the rotor, the magnitude of the drive current is maintained; When it is determined that the magnitude of the drive current is large relative to the rotation load of the rotor, the magnitude of the drive current is reduced; When it is determined that the magnitude of the drive current is small relative to the rotation load of the rotor, the magnitude of the drive current is increased. Effect of the Invention

[0015] According to one aspect of the present invention, an electric valve control device supplies a drive current to a stator to rotate a rotor. The electric valve control device acquires a voltage generated in the stator by the rotation of the rotor. The electric valve control device determines a relationship between the rotation load of the rotor and the magnitude of the drive current based on the acquired voltage. When the electric valve control device determines that the magnitude of the drive current is appropriate for the rotation load of the rotor, it maintains the magnitude of the drive current, when it determines that the magnitude of the drive current is large for the rotation load of the rotor, it reduces the magnitude of the drive current, and when it determines that the magnitude of the drive current is small for the rotation load of the rotor, it increases the magnitude of the drive current.

[0016] According to another aspect of the present invention, the motor-operated valve control device supplies a drive current to the stator to rotate the rotor. The motor-operated valve control device acquires a current generated in the stator by the rotation of the rotor. The motor-operated valve control device determines a relationship between the rotation load of the rotor and the magnitude of the drive current based on the acquired current. When the motor-operated valve control device determines that the magnitude of the drive current is appropriate for the rotation load of the rotor, it maintains the magnitude of the drive current, when it determines that the magnitude of the drive current is large for the rotation load of the rotor, it reduces the magnitude of the drive current, and when it determines that the magnitude of the drive current is small for the rotation load of the rotor, it increases the magnitude of the drive current.

[0017] As a result, the motor-operated valve control device can supply to the stator a drive current of an appropriate magnitude relative to the rotational load of the rotor, thereby reducing the power consumption of the motor-operated valve. [Brief description of the drawings]

[0018] [Figure 1] 1 is a block diagram of an air conditioning system having an electric valve device. [Diagram 2] FIG. 2 is a cross-sectional view of the motor-operated valve device of FIG. [Diagram 3] 3 is a diagram showing a valve stem holder of the motor-operated valve device of FIG. 2. [Figure 4] 3 is a side view of a guide bush provided in the motor-operated valve device of FIG. 2. [Diagram 5] 3 is a diagram showing a stopper member of the motor-operated valve device of FIG. 2. [Figure 6] 3 is a plan view of a valve stem holder, a stopper member, a rotor, and a stator that the motor-operated valve device of FIG. 2 has. [Figure 7] 3 is a diagram showing a computer, a motor driver including a current circuit having a switch element, and a stepping motor included in the motor-operated valve device of FIG. 2. FIG. [Figure 8] 4 is a diagram showing an example of a correspondence relationship between a pulse input to a stepping motor and an A-phase current target value and a B-phase current target value. FIG. [Figure 9] 4A and 4B are diagrams illustrating an example of an A-phase current waveform and a B-phase current waveform. [Figure 10] 2 is a diagram showing a schematic diagram of the positional relationship between the magnetic poles of the rotor and the pole teeth of the stator (when pulse P[1] is input). FIG. [Figure 11] 1 is a diagram showing a schematic diagram of the positional relationship between the magnetic poles of the rotor and the pole teeth of the stator (when pulse P[2] is input). [Figure 12] 1 is a diagram showing a schematic diagram of the positional relationship between the magnetic poles of the rotor and the pole teeth of the stator (when pulse P[3] is input). [Figure 13] 1 is a diagram showing a schematic diagram of the positional relationship between the magnetic poles of the rotor and the pole teeth of the stator (when pulse P[4] is input). [Figure 14]1 is a diagram showing a schematic diagram of the positional relationship between the magnetic poles of the rotor and the pole teeth of the stator (when pulse P[5] is input). [Figure 15] 1 is a diagram showing a schematic diagram of the positional relationship between the magnetic poles of the rotor and the pole teeth of the stator (when pulse P[6] is input). [Figure 16] FIG. 2 is a diagram showing a schematic diagram of the positional relationship between the magnetic poles of the rotor and the pole teeth of the stator (when pulse P[7] is input). [Figure 17] FIG. 2 is a diagram showing a schematic diagram of the positional relationship between the magnetic poles of the rotor and the pole teeth of the stator (when pulse P[8] is input). [Figure 18] FIG. 4 is a diagram showing an example of a waveform of a voltage generated in a stator by rotation of a rotor. [Figure 19] FIG. 19 is an enlarged view of a portion of FIG. [Figure 20] FIG. 4 is a diagram showing an example of a data table relating to a waveform of a voltage generated in a stator by rotation of a rotor. [Figure 21] FIG. 4 is a diagram showing a change in the rotation angle of the rotor for each driving current. [Figure 22] FIG. 4 is a diagram showing the waveform of a voltage generated in a stator by rotation of a rotor for each driving current. [Diagram 23] 13 is a graph showing the relationship between the magnitude of the drive current and the dissimilarity index value (when the magnitude of the drive current corresponding to the reference voltage waveform is 0.30 [A]). [Figure 24] 13 is a graph showing the relationship between the magnitude of the drive current and the dissimilarity index value (when the magnitude of the drive current corresponding to the reference voltage waveform is 0.06 [A]). [Diagram 25] 13 is a graph showing the relationship between the magnitude of the drive current and the dissimilarity index value (when the magnitude of the drive current corresponding to the reference voltage waveform is 0.60 [A]). [Figure 26] 13 is a graph showing the relationship between the magnitude of the drive current and the dissimilarity index value (when the magnitude of the drive current corresponding to the reference voltage waveform is 0.30 [A] and 0.06 [A]). [Figure 27]13 is a graph showing the relationship between the magnitude of the drive current and the dissimilarity index value (when the magnitude of the drive current corresponding to the reference voltage waveform is 0.06 [A] and 0.60 [A]). [Figure 28] 1 is a graph (part 1) showing the relationship between the magnitude of the rotational load of the rotor and the dissimilarity index value. [Figure 29] 13 is a graph (part 2) showing the relationship between the magnitude of the rotational load of the rotor and the dissimilarity index value. [Diagram 30] 4A and 4B are diagrams showing an example of a waveform of a voltage generated in a stator by rotation of a rotor and a reference waveform of the voltage; [Diagram 31] 4 is a flowchart showing an example of the operation of the motor-operated valve control device. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] The motor-operated valve device will be described below with reference to FIGS.

[0020] FIG. 1 is a block diagram of an air conditioning system having an electric valve device. FIG. 2 is a cross-sectional view of the electric valve device of FIG. 1. FIG. 3 is a diagram showing a valve stem holder of the electric valve device of FIG. 2. FIG. 3A is a perspective view of the valve stem holder, and FIG. 3B is a plan view of the valve stem holder. FIG. 4 is a side view of a guide bush of the electric valve device of FIG. 2. FIG. 5 is a diagram showing a stopper member of the electric valve device of FIG. 2. FIG. 5A is a perspective view of the stopper member, and FIG. 5B is a plan view of the stopper member. FIG. 6 is a plan view of the valve stem holder, the stopper member, the rotor, and the stator of the electric valve device of FIG. 2. In FIG. 6, the magnetic poles of the rotor and the stator are shown typically. FIG. 7 is a diagram explaining a computer, a motor driver including a current circuit having a switch element, and a stepping motor of the electric valve device of FIG. 2. FIG. 8 is a diagram showing an example of a correspondence relationship between a pulse input to the stepping motor and an A-phase current target value and a B-phase current target value. FIG. 9 is a diagram showing an example of the waveform of an A-phase current and a waveform of a B-phase current supplied to the stator.

[0021] Figures 10 to 17 are diagrams showing the positional relationship between the magnetic poles of the rotor and the pole teeth of the stator. Figures 10 to 17 show the case where pulses P[1] to P[8] are input to the stepping motor. Figures 10 to 17 show the magnetic poles of the rotor and the stator.

[0022] FIG. 18 is a diagram showing an example of a waveform of a voltage generated in the stator by the rotation of the rotor. FIG. 19 is a diagram showing an enlarged view of a part of FIG. 18 (a section corresponding to pulse P[1]). In FIG. 18 and FIG. 19, the horizontal axis is time and the vertical axis is voltage. FIG. 20 is a diagram showing an example of a data table relating to a waveform of a voltage generated in the stator by the rotation of the rotor. FIG. 21 is a diagram showing a change in the rotation angle of the rotor for each drive current. In FIG. 21, the horizontal axis is time and the vertical axis is rotation angle. FIG. 22 is a diagram showing a waveform of a voltage generated in the stator by the rotation of the rotor for each drive current. In FIG. 22, the horizontal axis is time and the vertical axis is voltage.

[0023] 23 to 27 are graphs showing the relationship between the magnitude of the drive current supplied to the stator and the dissimilarity index value. In FIG. 23 to FIG. 27, the horizontal axis is the magnitude of the drive current, and the vertical axis is the dissimilarity index value (Score). FIG. 23 to FIG. 25 show graphs when the magnitude of the drive current corresponding to the reference voltage waveform is 0.30 [A], 0.06 [A], and 0.60 [A]. FIG. 26 shows a graph when the magnitude of the drive current corresponding to the reference voltage waveform is 0.30 [A] and 0.06 [A]. FIG. 27 shows a graph when the magnitude of the drive current corresponding to the reference voltage waveform is 0.06 [A] and 0.60 [A].

[0024] Figures 28 and 29 are graphs showing the relationship between the magnitude of the rotation load of the rotor and the dissimilarity index value. Figure 30 is a diagram showing an example of a waveform of a voltage generated in a stator by rotation of the rotor and a reference waveform of the voltage. In Figure 30, the horizontal axis represents time and the vertical axis represents voltage. Figure 31 is a flowchart showing an example of the operation of the motor-operated valve control device.

[0025] The motor-operated valve device 1 according to this embodiment is used, for example, as a flow control valve that controls the flow rate of a refrigerant, which is a fluid, in the refrigeration cycle of an air conditioning system.

[0026] FIG. 1 shows an example of an air conditioning system 100 mounted on a vehicle. The air conditioning system 100 has a compressor 101, a condenser 102, an electric valve device 1 (electric valve 5), and an evaporator 103, which are connected in this order via piping 105. The electric valve device 1 is an expansion valve. The air conditioning system 100 has an air conditioning control device 110. The air conditioning control device 110 is connected to the electric valve device 1 (electric valve control device 70) so as to be able to communicate with the electric valve device 1. The air conditioning control device 110 uses the electric valve device 1 to control the flow rate of refrigerant flowing through the piping 105.

[0027] As shown in FIG. 2, the motor-operated valve device 1 includes a motor-operated valve 5 and a motor-operated valve control device 70.

[0028] The motor-operated valve 5 includes a valve body 10 , a can 20 , a valve element 30 , a drive mechanism 40 , and a stator 60 .

[0029] The valve body 10 includes a main body member 11 and a connecting member 13. The main body member 11 has a cylindrical shape. The main body member 11 has a valve chamber 14, a valve port 17, and a valve seat 18. A first conduit 15 and a second conduit 16 are joined to the main body member 11. The first conduit 15 is arranged in a direction perpendicular to the axis L (left-right direction in FIG. 2) and is connected to the valve chamber 14. The second conduit 16 is arranged in the direction of the axis L (up-down direction in FIG. 2) and is connected to the valve chamber 14 via a valve port 17. The valve port 17 is surrounded by a ring-shaped valve seat 18 in the valve chamber 14. The main body member 11 has a circular fitting hole 11a. The fitting hole 11a is arranged on the upper end surface of the main body member 11. The inner peripheral surface of the fitting hole 11a has a plane 11d facing leftward in FIG. 2. A through hole 11b communicating with the valve chamber 14 is provided at the bottom surface of the fitting hole 11a. The connecting member 13 has a circular ring plate shape. The inner peripheral edge of the connecting member 13 is joined to the upper end portion of the main body member 11. The main body member 11 and the connecting member 13 are made of metal such as aluminum alloy, stainless steel, or brass.

[0030] The can 20 is made of a metal such as stainless steel. The can 20 has a cylindrical shape. The lower end of the can 20 is open and the upper end is closed. The lower end of the can 20 is joined to the outer periphery of the connection member 13.

[0031] The valve body 30 has a first shaft portion 31, a second shaft portion 32, and a valve portion 33. The first shaft portion 31 has a cylindrical shape. The second shaft portion 32 has a cylindrical shape. The diameter of the second shaft portion 32 is smaller than the diameter of the first shaft portion 31. The second shaft portion 32 is coaxially connected to the upper end portion of the first shaft portion 31. The valve body 30 has a step portion 34 which is an annular flat surface facing upward. The step portion 34 is disposed at the connection portion between the first shaft portion 31 and the second shaft portion 32. The valve portion 33 has a substantially conical shape whose diameter decreases from the top to the bottom. The valve portion 33 is coaxially connected to the lower end portion of the first shaft portion 31. The valve portion 33 is disposed in the valve port 17. A variable throttle portion is formed between the valve portion 33 and the valve port 17. The valve portion 33 faces the valve port 17 and the valve seat 18. When the valve portion 33 comes into contact with the valve seat 18, the valve port 17 is closed. When the valve portion 33 moves away from the valve seat 18, the valve port 17 is opened.

[0032] The drive mechanism 40 moves the valve element 30 in the vertical direction (the direction of the axis L). The valve port 17 is opened and closed by the movement of the valve element 30. The drive mechanism 40 has a rotor 41, a valve stem holder 42, a guide bush 43, a stopper member 44, and a fixing device 45.

[0033] The rotor 41 has a cylindrical shape. The outer diameter of the rotor 41 is slightly smaller than the inner diameter of the can 20. The rotor 41 is disposed inside the can 20. The rotor 41 is rotatable relative to the valve body 10. The rotor 41 has a plurality of N poles and a plurality of S poles. The plurality of N poles and the plurality of S poles are disposed on the outer peripheral surface of the rotor 41. The plurality of N poles and the plurality of S poles extend in the vertical direction. The plurality of N poles and the plurality of S poles are disposed alternately at equal angular intervals in the circumferential direction. The rotor 41 has, for example, 12 N poles and 12 S poles. The angle between adjacent N poles and S poles is 15 degrees.

[0034] FIG. 3 shows the valve stem holder 42. The valve stem holder 42 has a cylindrical shape. The lower end of the valve stem holder 42 is open. An upper wall portion 42a is provided at the upper end of the valve stem holder 42. The upper wall portion 42a has an axial hole 42b. The valve stem holder 42 is fitted into a fitting hole 41a of the rotor 41. The valve stem holder 42 rotates together with the rotor 41. A movable stopper 42s is arranged at the lower end of the outer circumferential surface of the valve stem holder 42. The movable stopper 42s is a protrusion that protrudes radially outward. The second shaft portion 32 of the valve body 30 is arranged in the axial hole 42b so as to be movable in the direction of the axis L. A washer 46 is arranged on the lower surface of the upper wall portion 42a of the valve stem holder 42. A valve-closing spring 47 is arranged between the washer 46 and the step portion 34 of the valve body 30. The valve-closing spring 47 is a coil spring, and presses the valve body 30 toward the valve seat 18. A female thread 42c is provided on the inner circumferential surface of the valve shaft holder 42. The movable stopper 42s is fixed to the rotor 41.

[0035] FIG. 4 shows the guide bush 43. The guide bush 43 has a base portion 43a and a support portion 43b. The base portion 43a has a cylindrical shape. The outer peripheral surface of the base portion 43a has a flat surface 43d. The base portion 43a is press-fitted into the fitting hole 11a of the main body member 11, and the flat surface 43d contacts the flat surface 11d of the fitting hole 11a. As a result, the central axis of the main body member 11 and the central axis of the guide bush 43 coincide on the axis L, and the guide bush 43 is correctly positioned around the axis L with respect to the main body member 11. The support portion 43b has a cylindrical shape. The outer diameter of the support portion 43b is smaller than the outer diameter of the base portion 43a. The inner diameter of the support portion 43b is the same as the inner diameter of the base portion 43a. The support portion 43b is coaxially connected to the upper end portion of the base portion 43a. A male thread 43c is provided on the outer peripheral surface of the support portion 43b. The male thread 43c is screwed into the female thread 42c of the valve shaft holder 42. The first shaft portion 31 of the valve body 30 is disposed inside the guide bush 43. The guide bush 43 supports the valve body 30 so as to be movable in the axial L direction.

[0036] FIG. 5 shows the stopper member 44. The stopper member 44 has a stopper body 44a. The stopper body 44a has a cylindrical shape. An internal thread 44c is provided on the inner peripheral surface of the stopper body 44a. A fixed stopper 44s is disposed on the outer peripheral surface of the stopper body 44a. The fixed stopper 44s is a protrusion that protrudes radially outward. The internal thread 44c is screwed into the external thread 43c until the stopper body 44a abuts against the base 43a of the guide bush 43. This fixes the stopper member 44 to the guide bush 43. The fixed stopper 44s is fixed to the valve body 10.

[0037] The fixture 45 has a fixed portion 45a and a flange portion 45b. The fixed portion 45a has a stepped cylindrical shape. The second shaft portion 32 of the valve body 30 is disposed inside the fixed portion 45a. The fixed portion 45a is joined to the second shaft portion 32. The flange portion 45b is connected to the lower end portion of the fixed portion 45a. A return spring 48 is disposed outside the fixture 45. The return spring 48 is a coil spring.

[0038] The motor-operated valve 5 has a drive mechanism 40 that uses the rotation of the rotor 41 without reducing the speed. The motor-operated valve 5 may have a drive mechanism having a speed reduction mechanism that reduces the speed of the rotation of the rotor 41, instead of the drive mechanism 40.

[0039] The stator 60 has a cylindrical shape. The stator 60 includes an A-phase stator 61 and a B-phase stator 62.

[0040] 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 angular intervals in the circumferential direction. The A-phase stator 61 has, for example, 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 become magnetic poles of different polarities.

[0041] 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 angular intervals in the circumferential direction. The B-phase stator 62 has, for example, 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 become magnetic poles of different polarities.

[0042] The A-phase stator 61 and the B-phase stator 62 are arranged coaxially. The A-phase stator 61 is in contact with the B-phase stator 62. 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. In other words, the B-phase stator 62 is located at a position rotated 7.5 degrees around the axis L with respect to the A-phase stator 61 from the position where the pole tooth 61a and the pole tooth 62a are aligned in the axis L direction.

[0043] The can 20 is disposed inside the stator 60. The rotor 41 is disposed inside the can 20. The stator 60 and the rotor 41 form a stepping motor 66.

[0044] The stepping motor 66 is connected to the motor-operated valve control device 70. Specifically, as shown in Fig. 7, terminals A1, A2 of the A-phase coil 61c and terminals B1, B2 of the B-phase coil 62c are connected to a motor driver 77 of the motor-operated valve control device 70.

[0045] Pulses P (P[1] to P[8]) are input to the stepping motor 66, causing the rotor 41 to rotate. Specifically, a drive current corresponding to the pulses P is supplied to the stator 60 of the stepping motor 66, causing the rotor 41 to rotate. In this specification, "input of the pulses P to the stepping motor 66" is synonymous with "supply of a drive current corresponding to the pulses P to the stator 60 of the stepping motor 66."

[0046] Pulses P[1] to P[8] are input to the stepping motor 66 in sequence. A-phase current Ia, which is a drive current corresponding to the pulse P, is supplied to the A-phase stator 61. A-phase current Ib, which is a drive current corresponding to the pulse P, is supplied to the B-phase stator 62. The combination of the A-phase current Ia and the B-phase current Ib differs for each pulse P. The number of combinations is eight, which is called the number of patterns of the pulse P. The "pattern" is also called the "switching mode." The numbers (1 to 8) of the pulses P[1] to P[8] are pattern numbers for identifying the pulses P[1] to P[8]. For example, the period of the pulse P is 8 ms, and one period T including the pulses P[1] to P[8] is 64 ms. 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.

[0047] An A-phase current target value Ita corresponding to pulses P[1] to P[8] is set for the A-phase current Ia. A B-phase current target value Itb corresponding to pulses P[1] to P[8] is set for the B-phase current Ib. Fig. 8 shows an example of the correspondence between the pulse P and the A-phase current target value Ita and the B-phase current target value Itb.

[0048] 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.

[0049] FIG. 9 shows a schematic diagram of the waveform of the A-phase current Ia and the waveform of the B-phase current Ib when pulses P are input to the stepping motor 66 in ascending order. In FIG. 9, the A-phase current Ia has the same magnitude and current direction as the A-phase current target value Ita, and the B-phase current Ib has the same magnitude and current direction as the B-phase current target value Itb. In FIG. 8 and FIG. 9, 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.

[0050] When pulse P[1] or P[5] is input to stepping motor 66, A-phase current Ia is supplied to A-phase stator 61, and B-phase current Ib is not supplied to B-phase stator 62. When pulse P[3] or P[7] is input to stepping motor 66, A-phase current Ia is not supplied to A-phase stator 61, and B-phase current Ib is supplied to B-phase stator 62. When a pulse P[2], P[4], P[6] or P[8] is input to the stepping motor 66, an A-phase current Ia is supplied to the A-phase stator 61, and a B-phase current Ib is supplied to the B-phase stator 62.

[0051] 10 to 17 show examples of the positional relationship between the rotor 41 and the stator 60 when pulses P[1] to P[8] are input. In order to make it easier to understand the positional relationship between the rotor 41 and the stator 60 (A-phase stator 61, B-phase stator 62) in Fig. 10 to 17, the reference pole tooth 61a and the reference magnetic pole (S pole) of the rotor 41 are marked with black circles.

[0052] When the rotor 41 is rotated in the first direction (clockwise in Figs. 10 to 17), pulses P are cyclically input to the stepping motor 66 in ascending order (the order of pulses P[1] to P[8]). When the rotor 41 rotates in the first direction, the rotor 41 and the valve shaft holder 42 move downward due to the feed screw action of the female thread 42c of the valve shaft holder 42 and the male thread 43c of the guide bush 43. The rotor 41 (valve shaft holder 42) presses the valve body 30 downward via the valve closing spring 47. The valve body 30 moves downward and the valve portion 33 comes into contact with the valve seat 18. The position of the rotor 41 at this time is the valve closing position Rc. When the rotor 41 is further rotated in the first direction from this state, the valve closing spring 47 is compressed and the rotor 41 moves further downward. The valve body 30 does not move downward. When the movable stopper 42s of the valve stem holder 42 comes into contact with the fixed stopper 44s of the stopper member 44, the rotation of the rotor 41 in the first direction is restricted. The position of the rotor 41 at this time is the reference position Rx. The movable stopper 42s and the fixed stopper 44s form a stopper mechanism 49 that restricts the rotation of the rotor 41 in the first direction.

[0053] When the rotor 41 is rotated in a second direction (counterclockwise in Figs. 10 to 17) opposite to the first direction, pulses P are cyclically input to the stepping motor 66 in descending order (the order of pulses P[8] to P[1]). When the rotor 41 rotates in the second direction, the rotor 41 and the valve stem holder 42 move upward due to the feed screw action of the female thread 42c of the valve stem holder 42 and the male thread 43c of the guide bush 43. The rotor 41 (valve stem holder 42) pushes the fixture 45 upward. The valve body 30 moves upward together with the fixture 45, and the valve body 30 separates from the valve seat 18. The position of the rotor 41 when the flow rate of the fluid at the valve port 17 (opening of the valve port 17) is a predetermined set value in a predetermined flow measurement environment is defined as the valve open position Ro. The set value is appropriately set according to the configuration and use of the motor-operated valve device 1. When the rotor 41 rotates in the second direction and reaches the fully open position Rz, the valve body 30 is farthest from the valve orifice 17, and the valve orifice 17 opens to the maximum extent.

[0054] The number of pulses P for rotating the rotor 41 from the fully open position Rz to the reference position Rx is called the stroke number Ns. In other words, when pulses P with the stroke number Ns are input to the stepping motor 66 of the motor-operated valve 5 with the rotor 41 in the fully open position Rz, the rotor 41 is positioned at the reference position Rx. For example, the stroke number Ns is 500. The number of pulses P for rotating the rotor 41 from the reference position Rx to the fully open position Rz is also the stroke number Ns.

[0055] An initialization number Ni is set based on the stroke number Ns. The initialization number Ni is the number of pulses P sufficient to rotate the rotor 41 from the fully open position Rz to the reference position Rx. In other words, regardless of the position of the rotor 41, when the pulses P of the initialization number Ni are input to the stepping motor 66, the rotor 41 is positioned at the reference position Rx. The initialization number Ni is, for example, 1.05 to 1.3 times the stroke number Ns. The initialization number Ni is used in an initialization operation that positions the rotor 41 at the reference position Rx.

[0056] In the motor-operated valve 5, the valve port 17, valve seat 18, can 20, valve body 30, rotor 41, valve shaft holder 42, guide bush 43, and stator 60 (A-phase stator 61, B-phase stator 62) each have a central axis that coincides with the axis L.

[0057] The motor-operated valve control device 70 has a substrate 71 on which a plurality of electronic components (not shown) are mounted. As shown in Fig. 1, the motor-operated valve control device 70 has a non-volatile memory 75, a communication device 76, a motor driver 77, and a computer 80. The motor-operated valve control device 70 controls the motor-operated valve 5 based on commands from the air conditioner control device 110.

[0058] The non-volatile memory 75 stores data that needs to be retained even when the power is cut off. The non-volatile memory 75 is, for example, an EEPROM or a flash memory.

[0059] The communication device 76 is communicatively connected to the air conditioner control device 110 via a wired communication bus 120. The air conditioner system 100 employs a communication method such as Local Interconnect Network (LIN) or Controller Area Network (CAN). The communication device 76 may be connected to the air conditioner control device 110 so as to be able to communicate wirelessly.

[0060] The motor driver 77 is controlled by the computer 80 and supplies driving currents (A-phase current Ia and B-phase current Ib) to the stator 60 of the stepping motor 66 .

[0061] The motor driver 77 is connected to the stator 60 (FIG. 7). The motor driver 77 supplies an A-phase current Ia to the A-phase coil 61c, and supplies a B-phase current Ib to the B-phase coil 62c.

[0062] The motor driver 77 receives a pulsed step signal (STEP) and a direction signal (DIR) from the computer 80. Inputting a step signal when a direction signal corresponding to a first direction is input to the motor driver 77 corresponds to inputting pulses P in ascending order to the stepping motor 66. Inputting a step signal when a direction signal corresponding to a second direction is input to the motor driver 77 corresponds to inputting pulses P in descending order to the stepping motor 66.

[0063] Further, a current control signal (CONTROL) is input to the motor driver 77 from the computer 80. The current control signal is a signal for setting the A-phase current target value Ita and the B-phase current target value Itb in the motor driver 77.

[0064] 7, the motor driver 77 has H-bridge circuits 77A and 77B and a current control unit 77C. The H-bridge circuits 77A and 77B are current circuits. The motor driver 77 drives the stepping motor 66 in a bipolar manner.

[0065] The H-bridge circuit 77A is connected to the A-phase coil 61c. The H-bridge circuit 77A has switches SW11, SW12, SW13, and SW14 which are switching elements. The H-bridge circuit 77B is connected to the B-phase coil 62c. The H-bridge circuit 77B has switches SW21, SW22, SW23, and SW24 which are switching elements. The switches SW11, SW12, SW13, and SW14 and the switches SW21, SW22, SW23, and SW24 are, for example, N-channel MOSFETs or P-channel MOSFETs, and both may be used together.

[0066] The switches SW11, SW12, SW13, and SW14 and the switches SW21, SW22, SW23, and SW24 are controlled to be on (conductive state) / off (non-conductive state).

[0067] The current control section 77C controls the H-bridge circuits 77A and 77B in response to a step signal and a direction signal from the computer 80 using a pulse width modulation (PWM) control method.

[0068] When A-phase current Ia flowing from terminal A1 to terminal A2 is supplied to A-phase coil 61c: (1) The current control unit 77C turns off the switches SW12 and SW13. (2) Current control unit 77C controls the on-time (ie, duty cycle) of switches SW11 and SW14 so that the magnitude of A-phase current Ia is equal to the magnitude of A-phase current target value Ita.

[0069] When A-phase current Ia flowing from terminal A2 to terminal A1 is supplied to A-phase coil 61c: (1) The current control unit 77C turns off the switches SW11 and SW14. (2) Current control unit 77C controls the ON time of switches SW12 and SW13 so that the magnitude of A-phase current Ia becomes equal to the magnitude of A-phase current target value Ita.

[0070] When a B-phase current Ib flowing from terminal B1 to terminal B2 is supplied to the B-phase coil 62c: (1) The current control unit 77C turns off the switches SW22 and SW23. (2) The current control unit 77C controls the ON time of the switches SW21 and SW24 so that the magnitude of the B-phase current Ib becomes equal to the magnitude of the B-phase current target value Itb.

[0071] When a B-phase current Ib flowing from terminal B2 to terminal B1 is supplied to the B-phase coil 62c: (1) The current control unit 77C turns off the switches SW21 and SW24. (2) The current control unit 77C controls the ON time of the switches SW22 and SW23 so that the magnitude of the B-phase current Ib becomes equal to the magnitude of the B-phase current target value Itb.

[0072] The current control unit 77C may control the H-bridge circuits 77A and 77B using a control method other than the pulse width modulation control method.

[0073] The computer 80 is a microcomputer for embedded devices in which a CPU, a ROM, a RAM, an input / output interface, an A / D converter, etc. are incorporated in one package. The computer 80 may include a non-volatile memory 75, a communication device 76, and a motor driver 77. The computer 80 functions as a rotation control unit 81, an acquisition unit 82, and a determination unit 83 by the CPU executing a program stored in the ROM.

[0074] The rotation control unit 81 inputs a pulse P to the stepping motor 66 to rotate the rotor 41 in a first direction or a second direction. Specifically, the rotation control unit 81 controls the motor driver 77 based on a command from the air conditioner control device 110 to supply an A-phase current Ia and a B-phase current Ib to the stator 60 (A-phase coil 61c, B-phase coil 62c). The rotation control unit 81 inputs a step signal, a direction signal, and a current control signal to the motor driver 77.

[0075] The acquisition unit 82 acquires the voltage generated in the stator 60 due to the rotation of the rotor 41 , that is, the voltage electromagnetically induced in the stator 60 .

[0076] Specifically, the acquisition unit 82 acquires the voltage VB generated between the terminals B1 and B2 of the B-phase coil 62c in a time series manner when the rotation control unit 81 supplies a drive current only to the A-phase coil 61c in response to the pulses P[1] and P[5]. The acquisition unit 82 acquires the voltage VA generated between the terminals A1 and A2 of the A-phase coil 61c in a time series manner when the rotation control unit 81 supplies a drive current only to the B-phase coil 62c in response to the pulses P[3] and P[7]. The acquisition unit 82 does not acquire the voltage VA and the voltage VB when the rotation control unit 81 supplies a drive current to the A-phase coil 61c and the B-phase coil 62c in response to the pulses P[2], P[4], P[6], and P[8]. In the following description, the voltage VA and the voltage VB acquired by the acquisition unit 82 are simply referred to as "voltage V".

[0077] Acquiring unit 82 may acquire voltage V in time series when rotation control unit 81 supplies drive current to A-phase coil 61c and B-phase coil 62c in response to pulses P[1] to P[8]. In this configuration, acquiring unit 82 separates a voltage component related to electromagnetic induction from the voltage generated between terminals A1 and A2, and sets this voltage component as voltage VA. Acquiring unit 82 separates a voltage component related to electromagnetic induction from the voltage generated between terminals B1 and B2, and sets this voltage component as voltage VB.

[0078] The voltage V acquired in a time series is the waveform of the voltage V. In this specification, a "waveform" refers to a change over time in a physical quantity (voltage) at one fixed point. When a "waveform" is visualized, it is expressed on a coordinate plane with the physical quantity on the vertical axis and time on the horizontal axis. In addition, invisible things such as a data table in which physical quantity data and time data are associated and stored in the RAM of the computer 80 or the non-volatile memory 75 are also included in the "waveform". In addition, the "area of ​​the waveform" is the area of ​​the region enclosed by the waveform and the horizontal axis when the waveform is expressed on a coordinate plane with the physical quantity on the vertical axis and time on the horizontal axis corresponding to physical quantity 0.

[0079] Fig. 18 shows an example of the waveform of the voltage VB when the rotor 41 is rotated in the first direction. The waveforms shown in Fig. 18 include waveforms of the voltage VB corresponding to the pulses P[1] and P[5]. Fig. 19 shows an example of the waveform of the voltage VB corresponding to the pulse P[1].

[0080] The acquisition unit 82 acquires the voltage V in time series at a predetermined sampling period during the period from the start to the end of the pulse P. For example, the length from the start to the end of the pulse P is 8 ms, and the sampling period is 200 μs. For example, the acquisition unit 82 acquires the voltage V 40 times in response to the input of one pulse P.

[0081] The voltage V acquired by the acquisition unit 82 may be stored in the RAM as a data table. An example of the data table is shown in Fig. 20. In the data table, times t at predetermined time intervals from the start of the pulse P (time 0) are associated with voltage v, which is the voltage V at the time t. The interval between the times t is the same as the sampling period (200 μs). In Fig. 20, the unit of the time t is μs. The unit of the voltage v is mv. The unit of the time t and the unit of the voltage v may be original units, for example, units according to the sampling period and resolution of the A / D converter included in the motor-operated valve control device 70.

[0082] The determination unit 83 determines the relationship between the rotation load of the rotor 41 and the magnitude of the drive current supplied to the stator 60. Specifically, the determination unit 83 determines whether the magnitude of the drive current is appropriate for the rotation load.

[0083] In relation to the operation of the determination unit 83, the present inventors conducted the following Experiments 1 to 3.

[0084] (Experiment 1) The inventors used an electric valve 5 with a constant rotational load applied to the rotor 41 to obtain the rotation angle of the rotor 41 and the voltage generated in the stator 60 by the rotation of the rotor 41 when a plurality of drive currents of different magnitudes were supplied to the stator 60 in order to rotate the rotor 41. In this experiment, the rotational load of the rotor 41 was a viscous damping coefficient, and its magnitude was 10×10 -5 [Nm / (rad / s)]. The magnitudes of the driving currents are 0.04[A], 0.06[A], 0.10[A], 0.15[A], 0.30[A] and 0.60[A]. The results are shown in Figures 21 and 22.

[0085] As shown in FIG. 21, (1) when the drive current is 0.30 [A], the rotation angle of the rotor 41 increases stepwise, and the magnitude of the drive current is appropriate for the rotation load of the rotor 41. (2) When the drive current is 0.04 [A], the rotation angle of the rotor 41 does not increase, and the magnitude of the drive current is insufficient for the rotation load of the rotor 41. (3) When the drive current is 0.06 to 0.15 [A], compared to (1) above, the rotation angle of the rotor 41 increases with a delay, and the magnitude of the drive current is small for the rotation load of the rotor 41. (4) When the drive current is 0.60 [A], the rotation angle of the rotor 41 increases with oscillation, and the magnitude of the drive current is large for the rotation load of the rotor 41.

[0086] As shown in FIG. 22, the waveform of the voltage generated in the stator 60 by the rotation of the rotor 41 differs depending on the magnitude of the drive current.

[0087] (Experiment 2) The inventors used an electric valve 5 in which a constant rotational load was applied to the rotor 41, and obtained the voltage generated in the stator 60 due to the rotation of the rotor 41 when a plurality of drive currents of different magnitudes were supplied to the stator 60. Specifically, in the electric valve 5, pulses P were input in sequence to the stepping motor 66. Then, the waveform of the voltage VB generated in the B-phase stator 62 was obtained when a drive current was supplied only to the A-phase stator 61 in response to pulse P[1]. In this experiment, the rotational load of the rotor 41 was a viscous damping coefficient, and its magnitude was 10×10 -5 [Nm / (rad / s)]. The magnitude of the multiple drive currents ranges from 0.04[A] to 0.60[A] in increments of 0.01[A].

[0088] The waveform of the voltage VB is stored in the data storage device as the data table. The data table corresponds to a number of drive currents having magnitudes ranging from 0.04 [A] to 0.60 [A].

[0089] The inventors then used one of the multiple voltage VB waveforms corresponding to the multiple driving currents as a reference waveform of voltage VB, and obtained the degree of difference between the multiple voltage VB waveforms and the reference waveform of voltage VB.

[0090] Specifically, the inventors calculated a value (dissimilarity index value sv) indicating the degree of difference between the waveform of the voltage VB and the reference waveform of the voltage VB. The larger the dissimilarity index value sv, the greater the degree of difference between the waveform of the voltage VB and the reference waveform of the voltage VB.

[0091] The dissimilarity index value sv is calculated using a data table of the waveform of the voltage VB and a data table of the reference waveform of the voltage VB.

[0092] The method of calculating the dissimilarity index value sv is to (1) calculate a value (difference value dv) by subtracting the voltage v associated with time t in the data table of the reference waveform of voltage VB from the voltage v associated with that time t in the data table of the waveform of voltage VB, (2) calculate a value (intermediate value dv2) by squaring the difference value dv, and (3) add up the multiple intermediate values ​​dv2 calculated for each time t to calculate the dissimilarity index value sv.

[0093] The inventors then obtained graphs showing the relationship between the magnitude of the drive current and the dissimilarity index value sv. The graphs are shown in Figs. 23 to 25.

[0094] FIG. 23 shows a graph when the waveform of the voltage VB corresponding to a drive current of 0.30 [A] is used as the reference waveform of the voltage VB. In FIG. 23, when the magnitude of the drive current is 0.30 [A], the difference index value sv is 0, and the waveform of the voltage VB and the reference waveform of the voltage VB match. In FIG. 23, as the magnitude of the drive current increases from 0.30 [A], the difference index value sv gradually increases, and the difference between the waveform of the voltage VB and the reference waveform of the voltage VB gradually increases. In FIG. 23, as the magnitude of the drive current decreases from 0.30 [A], the difference index value sv gradually increases, and the difference between the waveform of the voltage VB and the reference waveform of the voltage VB gradually increases. In FIG. 23, as the magnitude of the drive current decreases from 0.10 [A], the difference index value sv gradually decreases, and the difference between the waveform of the voltage VB and the reference waveform of the voltage VB gradually decreases.

[0095] Fig. 24 shows a graph when the waveform of voltage VB corresponding to a drive current of 0.06 [A] is used as the reference waveform of voltage VB. In Fig. 24, when the magnitude of the drive current is 0.06 [A], the dissimilarity index value sv is 0, and the waveform of voltage VB and the reference waveform of voltage VB match. In Fig. 24, as the magnitude of the drive current increases from 0.06 [A], the dissimilarity index value sv gradually increases, and the difference between the waveform of voltage VB and the reference waveform of voltage VB gradually increases. The graph shown in Fig. 24 shows a monotonous increase.

[0096] FIG. 25 shows a graph when the waveform of the voltage VB corresponding to a drive current of 0.60 [A] is used as the reference waveform of the voltage VB. In FIG. 25, when the magnitude of the drive current is 0.60 [A], the difference index value sv is 0, and the waveform of the voltage VB and the reference waveform of the voltage VB match. In FIG. 25, as the magnitude of the drive current decreases from 0.60 [A], the difference index value sv gradually increases, and the difference between the waveform of the voltage VB and the reference waveform of the voltage VB gradually increases. In FIG. 25, as the magnitude of the drive current decreases from 0.10 [A], the difference index value sv gradually decreases, and the difference between the waveform of the voltage VB and the reference waveform of the voltage VB gradually decreases.

[0097] The results of this experiment show that when the relationship between the rotation load of the rotor 41 and the magnitude of the drive current supplied to the stator 60 changes, the waveform of the voltage VB changes. Since the voltage VA is symmetrical to the voltage VB, it is estimated that when the relationship changes, the waveform of the voltage VA also changes. In other words, the relationship is reflected in the voltage V (voltage VA, voltage VB) generated in the stator 60 by the rotation of the rotor 41. Therefore, the relationship can be determined based on the dissimilarity index value sv associated with the voltage. An example of a determination method is shown below.

[0098] Judgment method 1: A judgment value H11 is set based on the graph in FIG. 23. A waveform of voltage V corresponding to a drive current of 0.30 [A] is used as the reference waveform of voltage V. The waveform of voltage V is acquired. A dissimilarity index value sv is calculated using the waveform of voltage V and the reference waveform of voltage V. When the dissimilarity index value sv is less than or equal to judgment value H11 (section B), it is judged that the magnitude of the drive current is appropriate for the rotation load of rotor 41, and when the dissimilarity index value sv is greater than judgment value H11 (sections A and C), it is judged that the magnitude of the drive current is not appropriate for the rotation load of rotor 41.

[0099] Judgment method 2: The judgment values ​​H21 and H22 are set based on the graph in FIG. 24. The waveform of voltage V corresponding to a drive current of 0.06 [A] is used as the reference waveform of voltage V. The waveform of voltage V is acquired. The waveform of voltage V and the reference waveform of voltage V are used to calculate a dissimilarity index value sv. When the dissimilarity index value sv is less than the judgment value H21 and greater than or equal to the judgment value H22 (section B), it is judged that the magnitude of the drive current is appropriate for the rotation load of the rotor 41; when the dissimilarity index value sv is greater than the judgment value H21 (section C), it is judged that the magnitude of the drive current is large for the rotation load of the rotor 41; and when the dissimilarity index value sv is smaller than the judgment value H22 (section A), it is judged that the magnitude of the drive current is small for the rotation load of the rotor 41.

[0100] Judgment method 3: The judgment values ​​H31 and H32 are set based on the graph in FIG. 25. A waveform of voltage V corresponding to a drive current of 0.60 [A] is used as the reference waveform of voltage V. The waveform of voltage V is acquired. A dissimilarity index value sv is calculated using the waveform of voltage V and the reference waveform of voltage V. When the dissimilarity index value sv is less than the judgment value H31 and greater than or equal to the judgment value H32 (section B), it is judged that the magnitude of the drive current is appropriate for the rotation load of the rotor 41; when the dissimilarity index value sv is greater than the judgment value H31 (section A), it is judged that the magnitude of the drive current is small for the rotation load of the rotor 41; and when the dissimilarity index value sv is less than the judgment value H32 (section C), it is judged that the magnitude of the drive current is large for the rotation load of the rotor 41.

[0101] Judgment method 4: As shown in Figure 26, the graphs in Figures 23 and 24 are combined to set judgment values ​​H11 and H21. A waveform of voltage V corresponding to a drive current of 0.30 [A] is used as the reference waveform of voltage V (reference waveform 1). A waveform of voltage V corresponding to a drive current of 0.06 [A] is used as the reference waveform of voltage V (reference waveform 2). The waveform of voltage V is acquired. A dissimilarity index value sv1 is calculated using the waveform of voltage V and reference waveform 1. A dissimilarity index value sv2 is calculated using the waveform of voltage V and reference waveform 2. When the dissimilarity index value sv1 is less than the judgment value H11 (section B), it is judged that the magnitude of the drive current is appropriate for the rotational load of the rotor 41; when the dissimilarity index value sv1 is greater than the judgment value H11 and the dissimilarity index value sv2 is greater than the judgment value H21 (section C), it is judged that the magnitude of the drive current is large for the rotational load of the rotor 41; and when the dissimilarity index value sv1 is greater than the judgment value H11 and the dissimilarity index value sv2 is less than the judgment value H21 (section A), it is judged that the magnitude of the drive current is small for the rotational load of the rotor 41.

[0102] Judgment method 5: As shown in Figure 27, the graphs in Figures 24 and 25 are combined to set judgment values ​​H21 and H31. A waveform of voltage V corresponding to a drive current of 0.06 [A] is used as the reference waveform of voltage V (reference waveform 2). A waveform of voltage V corresponding to a drive current of 0.60 [A] is used as the reference waveform of voltage V (reference waveform 3). The waveform of voltage V is acquired. A dissimilarity index value sv2 is calculated using the waveform of voltage V and reference waveform 2. A dissimilarity index value sv3 is calculated using the waveform of voltage V and reference waveform 3 of voltage V. When the dissimilarity index value sv2 is less than or equal to the judgment value H21 and the dissimilarity index value sv3 is less than or equal to the judgment value H31 (section B), it is judged that the magnitude of the drive current is appropriate for the rotational load of the rotor 41; when the dissimilarity index value sv2 is greater than the judgment value H21 (section C), it is judged that the magnitude of the drive current is large for the rotational load of the rotor 41; and when the dissimilarity index value sv3 is greater than the judgment value H31 (section A), it is judged that the magnitude of the drive current is small for the rotational load of the rotor 41.

[0103] In the determination methods 1 to 5, waveforms of the voltage V corresponding to drive currents of 0.30 [A], 0.06 [A], and 0.60 [A] are used as the reference waveform of the voltage V. The waveform of the voltage V corresponding to which magnitude of the drive current is to be used as the reference waveform of the voltage V can be appropriately selected depending on the configuration, application, etc. of the motor-operated valve device 1.

[0104] (Experiment 3) The inventors used an electric valve 5 in which a plurality of rotational loads of different magnitudes were applied to the rotor 41, and obtained the voltage generated in the stator 60 due to the rotation of the rotor 41 when a drive current of a certain magnitude was supplied to the stator 60. Specifically, in the electric valve 5, pulses P were input in sequence to the stepping motor 66. Then, the waveform of the voltage VB generated in the B-phase stator 62 was obtained when a drive current was supplied only to the A-phase stator 61 in response to the pulse P[1].

[0105] In this experiment, the rotation load of the rotor 41 is the viscous damping coefficient, and its magnitude is 100×10 -5 From [Nm / (rad / s)] 10×10 -5 Up to [Nm / (rad / s)] 10×10 -5 [Nm / (rad / s)] increments. 10×10 -5 From [Nm / (rad / s)] 1×10 -5 Up to [Nm / (rad / s)] 1×10 -5 It is in increments of [Nm / (rad / s)]. The magnitude of the drive current is 0.30 [A].

[0106] The waveform of the voltage VB is stored in the data storage device as the data table. The data table has a size of 100×10 -5 [Nm / (rad / s)]~1×10 -5 Supports multiple rotational loads of [Nm / (rad / s)].

[0107] The inventors used a waveform of the voltage VB corresponding to a drive current of 0.30 [A] as a reference waveform of the voltage VB (reference waveform 1), and obtained the degree of difference (difference index value sv1) between the waveforms of the multiple voltage VB and reference waveform 1, as in Experiment 2. The inventors also used a waveform of the voltage VB corresponding to a drive current of 0.06 [A] as a reference waveform of the voltage VB (reference waveform 2), and obtained the degree of difference (difference index value sv2) between the waveforms of the multiple voltage VB and reference waveform 2, as in Experiment 2.

[0108] The inventors then obtained a graph showing the relationship between the magnitude of the rotor rotation load and the dissimilarity index values ​​sv1 and sv2. The graphs are shown in Figs. 28 and 29. In Figs. 28 and 29, the dashed line graph shows the dissimilarity index value sv1, and the dashed line graph shows the dissimilarity index value sv2. In Figs. 28 and 29, the rotation load increases leftward on the horizontal axis, and decreases rightward on the horizontal axis. When the rotation load increases, the drive current decreases relative to the rotation load. When the rotation load decreases, the drive current increases relative to the rotation load.

[0109] As shown in FIG. 28, as the rotation load of the rotor 41 increases (the drive current decreases relatively to the rotation load), the dissimilarity index value sv1 gradually increases and the dissimilarity index value sv2 gradually decreases.

[0110] As shown in FIG. 29, as the rotation load of the rotor 41 decreases (the drive current increases relatively to the rotation load), the dissimilarity index value sv1 gradually increases, and the dissimilarity index value sv2 gradually increases.

[0111] Although not shown in Figures 28 and 29, the rotation load is 10 x 10 -5 When the distance is [Nm / (rad / s)], the dissimilarity index value sv1 is 0.

[0112] Similar to experiment 2, the results of this experiment show that the waveform of voltage VB (and the waveform of voltage VA) changes when the relationship between the rotation load of rotor 41 and the magnitude of the drive current supplied to stator 60 changes. By setting the determination values ​​H11 and H21 in Figs. 28 and 29, the rotation load can be divided into sections A to C, similar to Fig. 26. This shows that a determination method similar to that in experiment 2 is effective even when the magnitude of the drive current is changed relative to the rotation load.

[0113] The judgment unit 83 adopts the above judgment method and judges the relationship between the rotational load of the rotor 41 and the magnitude of the drive current supplied to the stator 60 based on the degree of difference (difference index value sv) between the waveform of the voltage V acquired by the acquisition unit 82 and the reference waveform of the voltage V.

[0114] A reference waveform of a first voltage V and a reference waveform of a second voltage V are set for one pulse P[k] (k=1, 3, 5, 7). The reference waveform of the first voltage V is used to determine when the rotor 41 is rotating in a first direction. The reference waveform of the second voltage V is used to determine when the rotor 41 is rotating in a second direction.

[0115] The reference waveform of the first voltage VA set for the pulse P[ka] (ka = 3, 7) is set based on the waveform of the voltage VA obtained when a drive current is supplied only to the B-phase stator 62 in response to the pulse P[ka] input to the stepping motor 66 when rotating the rotor 41 in the first direction. The reference waveform of the second voltage VA set for the pulse P[ka] is set based on the waveform of the voltage VA obtained when a driving current is supplied only to the B-phase stator 62 in response to the pulse P[ka] input to the stepping motor 66 when rotating the rotor 41 in the second direction.

[0116] The reference waveform of the first voltage VB set for the pulse P[kb] (kb=1, 5) is set based on the waveform of the voltage VB obtained when a driving current is supplied only to the A-phase stator 61 in response to the pulse P[kb] input to the stepping motor 66 when rotating the rotor 41 in the first direction. The reference waveform of the second voltage VB set for the pulse P [kb] is set based on the waveform of the voltage VB obtained when a driving current is supplied only to the A-phase stator 61 in response to the pulse P [kb] input to the stepping motor 66 when rotating the rotor 41 in the second direction.

[0117] The reference waveform of the voltage V is stored in advance in the non-volatile memory 75 as a data table.

[0118] A first reference waveform table C1[k] and a second reference waveform table C2[k] are stored in the non-volatile memory 75. The first reference waveform table C1[k] is a reference waveform of a first voltage V set for a pulse P[k]. The second reference waveform table C2[k] is a reference waveform of a second voltage V set for a pulse P[k].

[0119] The first reference waveform table C1[k] and the second reference waveform table C2[k] have the same format as the data table in Fig. 20, and times t at predetermined time intervals from the start of the pulse P (time 0) are associated with the voltage v (reference voltage rv) at that time t. The interval between the times t is the same as the sampling period (200 μs). One data table has 40 pairs of times t and reference voltages rv.

[0120] The determination unit 83 calculates a value (dissimilarity index value sv) indicating the degree of difference between the waveform of the voltage V acquired by the acquisition unit 82 and a reference waveform of the voltage V.

[0121] When the acquisition unit 82 acquires a voltage v (voltage V) at acquisition time tv in response to the input of the pulse P[k], the determination unit 83 reads out a reference voltage rv associated with the time t corresponding to the acquisition time tv from a data table (first reference waveform table C1[k] or second reference waveform table C2[k]) of the reference waveform of the voltage V set for the pulse P[k]. The determination unit 83 calculates a value (difference value dv) obtained by subtracting the reference voltage rv from the voltage v. The determination unit 83 calculates a value (intermediate value dv2) obtained by squaring the difference value dv. The determination unit 83 calculates a dissimilarity index value sv[k] by adding up the multiple intermediate values ​​dv2 calculated in response to the input of the pulse P[k].

[0122] The determination unit 83 calculates the difference index value sv[k] using the voltage v acquired by the acquisition unit 82 during a part of the period from the start to the end of the pulse P[k]. Specifically, when the period from the start of the pulse P[k] to time t1 is defined as a first period p1, and the period from time t1 to time t2 is defined as a second period p2, the determination unit 83 calculates the difference index value sv[k] using the voltage v during the second period p2. The time t1 is a time after the start of the pulse P[k]. The time t2 is a time after the time t1 and before the end of the pulse P[k]. The time t2 may be the end of the pulse P[k]. FIG. 30 shows an example of the waveform of the voltage VB acquired in response to the input of the pulse P[1] (solid line: "acquired waveform") and the reference waveform of the voltage VB (dashed line). 30, the length of the vertical line connecting the waveform of the voltage VB and the reference waveform of the voltage VB in the second period p2 indicates the difference value dv used in calculating the dissimilarity index value sv[1]. The determination unit 83 does not use the voltage v in the first period p1 in calculating the dissimilarity index value sv[k].

[0123] The voltage v may include a voltage component (the former voltage component) related to the back electromotive force due to the inductance of the coil of the stator 60 and a voltage component (the latter voltage component) related to the electromagnetic induction due to the rotation of the rotor 41. At a time slightly after the start of the pulse P[k], the former voltage component is larger than the latter voltage component, and the former voltage component decreases with time. Therefore, the determination unit 83 calculates the difference index value sv[k] using the voltage v acquired by the acquisition unit 82 after a certain amount of time has passed since the start of the pulse P[k]. Specifically, the determination unit 83 calculates the difference index value sv[k] using the voltage v acquired by the acquisition unit 82 after the former voltage component becomes smaller than the latter voltage component. In this way, the ratio of the latter voltage component in the voltage v becomes relatively large, and the determination unit 83 can determine the relationship between the rotation load of the rotor 41 and the magnitude of the drive current supplied to the stator 60 with higher accuracy.

[0124] The length of the first period p1 is 5 to 50% of the period from the start to the end of the pulse P[k], and preferably 20 to 30%. The length of the second period p2 is 50 to 95% of the period from the start to the end of the pulse P[k], and preferably 70 to 80%. In the voltage v acquired by the acquisition unit 82 in the second period p2, the voltage component related to the back electromotive force due to the inductance of the coil of the stator 60 is smaller than the voltage component related to the electromagnetic induction due to the rotation of the rotor 41. Note that the determination unit 83 may calculate the dissimilarity index value sv[k] using the voltage v acquired by the acquisition unit 82 in the period from the start to the end of the pulse P[k] (the entire period). In this configuration, the start of the pulse P[k] is time t1, and the end of the pulse P[k] is time t2.

[0125] When the voltage v acquired at an acquisition time tv between time t1 and time t2 is v[tv], and the reference voltage rv associated with the time t corresponding to the acquisition time tv in the reference waveform data table is rv[tv], the dissimilarity index value sv is expressed by the following equation (1).

[0126]

number

[0127] The determination unit 83 determines the relationship between the rotation load of the rotor 41 and the magnitude of the drive current supplied to the stator 60 based on the difference index value sv[k]. Specifically, the determination unit 83 compares the difference index value sv[k] with a predetermined determination value H. The determination value H is, for example, the above-mentioned determination values ​​H11, H21, H22, H31, and H32. The determination unit 83 determines the relationship based on a comparison result between the difference index value sv[k] and the determination value H. The motor-operated valve control device 70 may have a determination value H[k] corresponding to the difference index value sv[k]. The determination values ​​H[k] may be the same value or may be different values ​​from each other. The determination unit 83 may calculate the difference index value sv for only one of the pulses P[k] and determine the relationship.

[0128] Next, an example of the operation of the motor-operated valve control device 70 will be described with reference to FIG.

[0129] In this operation, the motor-operated valve control device 70 uses any one of the above-mentioned determination methods 2 to 4 to determine the relationship between the rotation load of the rotor 41 and the magnitude of the drive current supplied to the stator 60. The non-volatile memory 75 stores reference waveforms of the voltage V (first reference waveform table C1, second reference waveform table C2) and a determination value H according to the determination method used by the motor-operated valve control device 70. The reference waveform of the voltage V is set based on the waveform of the voltage V acquired in advance in the motor-operated valve 5.

[0130] The motor-operated valve control device 70 (specifically, the computer 80) receives a command to change the valve opening (opening of the valve port 17) from the air conditioner control device 110 (S110). The motor-operated valve control device 70 obtains the number of pulses P (target number Nt) to be input to the stepping motor 66 in order to change the current valve opening to the target valve opening included in the command, and the rotation direction (first direction or second direction) of the rotor 41.

[0131] The motor-operated valve control device 70 starts inputting pulses P to the stepping motor 66 to rotate the rotor 41 in the calculated rotation direction (S120). Specifically, the motor-operated valve control device 70 inputs a current control signal for setting initial values ​​to the target values ​​of the drive current (A-phase current target value Ita, B-phase current target value Itb) corresponding to the pulses P[1] to P[8] and a direction signal indicating the rotation direction to the motor driver 77. Then, the motor-operated valve control device 70 starts inputting a step signal to the motor driver 77. The initial values ​​are set according to the maximum rotation load expected for the rotor 41.

[0132] The motor-operated valve control device 70 acquires the voltage V (S130). Specifically, the motor-operated valve control device 70 acquires the voltage VA in time series when a drive current is supplied only to the B-phase stator 62 in response to the pulse P[ka]. The motor-operated valve control device 70 also acquires the voltage VB in time series when a drive current is supplied only to the A-phase stator 61 in response to the pulse P[kb]. That is, the motor-operated valve control device 70 acquires the waveforms of the voltage VA and the voltage VB. The motor-operated valve control device 70 may store the waveforms of the voltage VA and the voltage VB in a RAM.

[0133] The motor-operated valve control device 70 determines the relationship between the rotation load of the rotor 41 and the magnitude of the drive current supplied to the stator 60 (S140). Specifically, the motor-operated valve control device 70 calculates a difference index value sv using the waveform of the voltage V and a reference waveform of the voltage V at the end of the pulse P[k], and determines the relationship based on the difference index value sv and the determination value H.

[0134] Here, a case where the motor-operated valve control device 70 uses the above-mentioned determination method 4 will be described. The motor-operated valve control device 70 calculates a difference index value sv1 using the waveform of the voltage V and a reference waveform 1. The motor-operated valve control device 70 calculates a difference index value sv2 using the waveform of the voltage V and a reference waveform 2. When the difference index value sv1 is equal to or smaller than a determination value H11, the motor-operated valve control device 70 determines that the magnitude of the drive current is appropriate for the rotation load of the rotor 41. When the difference index value sv1 is greater than the determination value H11 and the difference index value sv2 is greater than the determination value H21, the motor-operated valve control device 70 determines that the magnitude of the drive current is large for the rotation load of the rotor 41. When the difference index value sv1 is greater than the determination value H11 and the difference index value sv2 is equal to or smaller than the determination value H21, the motor-operated valve control device 70 determines that the magnitude of the drive current is small for the rotation load of the rotor 41.

[0135] When the motor-operated valve control device 70 determines that the magnitude of the drive current is appropriate for the rotation load of the rotor 41 (Y in S150), it does not change the target value of the drive current. In other words, the motor-operated valve control device 70 maintains the magnitude of the drive current.

[0136] When the motor-operated valve control device 70 determines that the magnitude of the drive current is large relative to the rotation load of the rotor 41 (N in S150, Y in S160), it reduces the magnitude of the drive current (S170). Specifically, the motor-operated valve control device 70 inputs a current control signal to the motor driver 77 to set a new value that is a predetermined magnitude (for example, 1 [mA]) smaller than the current value to the target value of the drive current corresponding to pulses P[1] to P[8]. Note that the motor-operated valve control device 70 prevents the target value of the drive current from becoming smaller than the lower limit value determined for the stepping motor 66.

[0137] When the motor-operated valve control device 70 determines that the magnitude of the drive current is small relative to the rotation load of the rotor 41 (N in S150, N in S160), it increases the magnitude of the drive current (S180). Specifically, the motor-operated valve control device 70 inputs a current control signal to the motor driver 77 to set a new value that is a predetermined magnitude (e.g., 1 [mA]) greater than the current value to the target value of the drive current corresponding to pulses P[1] to P[8]. Note that the motor-operated valve control device 70 prevents the target value of the drive current from exceeding the upper limit determined for the stepping motor 66.

[0138] The predetermined magnitude may be a fixed value determined in advance, or may be a value according to the difference between the dissimilarity index value sv and the judgment value H. Moreover, instead of the predetermined magnitude, a predetermined percentage (e.g., 3%) may be used. The motor-operated valve control device 70 may set a target value of the drive current using PID control.

[0139] The motor-operated valve control device 70 may reduce the magnitude of the drive current when it is determined multiple times in succession that the magnitude of the drive current is large relative to the rotation load of the rotor 41. The motor-operated valve control device 70 may increase the magnitude of the drive current when it is determined multiple times in succession that the magnitude of the drive current is small relative to the rotation load of the rotor 41.

[0140] The motor-operated valve control device 70 repeats the operations of steps S130 to S190 until the number of pulses P input to the stepping motor 66 (the number of pulses of the step signal) reaches the target number Nt (N in S190). When the number of pulses P input to the stepping motor 66 reaches the target number Nt (Y in S190), the motor-operated valve control device 70 stops inputting the pulses P to the stepping motor 66 (S200) and ends this operation.

[0141] As described above, the motor-operated valve device 1 includes the motor-operated valve 5 and the motor-operated valve control device 70. The motor-operated valve 5 includes the valve body 10 having the valve port 17, the stepping motor 66 having the rotor 41 and the stator 60, and the valve element 30 that moves relative to the valve port 17 when the rotor 41 rotates.

[0142] The motor-operated valve control device 70 supplies a drive current to the stator 60 for rotating the rotor 41 (rotation control unit 81). The motor-operated valve control device 70 acquires a voltage V generated in the stator 60 by the rotation of the rotor 41 (acquisition unit 82). The motor-operated valve control device 70 determines the relationship between the rotation load of the rotor 41 and the magnitude of the drive current based on the acquired voltage V (determination unit 83).

[0143] The motor-operated valve control device 70 maintains the magnitude of the drive current when it determines that the magnitude of the drive current is appropriate for the rotation load of the rotor 41. The motor-operated valve control device 70 reduces the magnitude of the drive current when it determines that the magnitude of the drive current is large for the rotation load of the rotor 41. The motor-operated valve control device 70 increases the magnitude of the drive current when it determines that the magnitude of the drive current is small for the rotation load of the rotor.

[0144] As a result, the motor-operated valve control device 70 can supply to the stator 60 a drive current of an appropriate magnitude relative to the rotational load of the rotor 41, and the power consumption of the motor-operated valve 5 can be reduced.

[0145] Furthermore, the motor-operated valve control device 70 determines the relationship between the rotation load of the rotor 41 and the magnitude of the drive current, based on the voltage V generated in the stator 60 by the rotation of the rotor 41. As a result, the motor-operated valve control device 70 does not require any components for detecting the rotation load of the rotor 41, and the motor-operated valve control device 70 or the motor-operated valve 5 can be configured simply.

[0146] Furthermore, the motor-operated valve control device 70 determines the relationship between the rotation load of the rotor 41 and the magnitude of the drive current based on the degree of difference between the waveform of the voltage V and the reference waveform of the voltage V. In this manner, the motor-operated valve control device 70 can determine the relationship with higher accuracy compared to a configuration that determines the relationship based on the area of ​​the waveform or the maximum amplitude of the waveform.

[0147] Furthermore, the motor-operated valve control device 70 calculates a difference index value sv indicating the degree of difference between the waveform of the voltage V and a reference waveform of the voltage V, and determines the relationship between the rotational load of the rotor 41 and the magnitude of the drive current based on the result of comparing the difference index value sv with the determination value H. In this manner, the motor-operated valve control device 70 can determine the relationship with higher accuracy.

[0148] Also, the reference waveform of the voltage V is a data table in which time t is associated with the reference voltage rv at the time t. The motor-operated valve control device 70 acquires the voltage V (voltage v) in a time series. The motor-operated valve control device 70 calculates an intermediate value dv2, which is a squared value of a difference value dv between the voltage v acquired at the acquisition time tv and the reference voltage rv associated with the time t corresponding to the acquisition time tv in the data table. The motor-operated valve control device 70 calculates a difference index value sv by adding up a plurality of intermediate values ​​dv2 calculated using the voltage v. In this way, the difference index value sv appropriately reflects the degree of difference in the shape of the waveform, unlike the area and maximum amplitude of the waveform. Therefore, the motor-operated valve control device 70 can determine the relationship between the rotation load of the rotor 41 and the magnitude of the drive current with higher accuracy.

[0149] There is a close relationship between voltage and current. Therefore, the motor-operated valve control device 70 may determine the relationship between the rotation load of the rotor 41 and the magnitude of the drive current supplied to the stator 60 by using the current generated in the stator 60 by the rotation of the rotor 41, instead of the voltage generated in the stator 60 by the rotation of the rotor 41. The configuration using the current waveform also provides the same effects as the configuration using the voltage waveform.

[0150] In this specification, terms indicating a shape, such as "cylinder" or "column", are also used for members or parts of members that have substantially the shape of the term. For example, a "cylindrical member" includes a cylindrical member and a substantially cylindrical member. In addition, in this specification, the term "same" may include the case where something is exactly the same as another, and the case where something is substantially the same as another.

[0151] Although the embodiments of the present invention have been described above, the present invention is not limited to the embodiments. 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]

[0152] 1...motor-operated valve device, 5...motor-operated valve, 10...valve body, 11...body member, 11a...fitting hole, 11b...through hole, 11d...flat surface, 13...connecting member, 14...valve chamber, 15...first conduit, 16...second conduit, 17...valve port, 18...valve seat, 20...can, 30...valve body, 31...first shaft portion, 32...second shaft portion, 33...valve portion, 34...step portion, 40...drive mechanism, 41...rotor, 41a...fitting hole, 42... Valve shaft holder, 42a...upper wall portion, 42b...shaft hole, 42c...female thread, 42s...movable stopper, 43...guide bush, 43a...base portion, 43b...support portion, 43c...male thread, 43d...flat surface, 44...stopper member, 44a...stopper body, 44c...female thread, 44s...fixed stopper, 45...fixing device, 45a...fixing portion, 45b...flange portion, 46...washer, 47...valve closing stopper spring, 48... return spring, 49... stopper mechanism, 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, 66... ​​stepping motor, 70... motor-operated valve control device, 71... board, 75... non-volatile memory, 76... communication device, 77... motor driver, 77A... H-bridge circuit, 77B... H-bridge circuit, 77C... current control unit, 80... computer, 81... rotation control unit, 82... acquisition unit, 83... determination unit, 100... air conditioning system, 101... compressor, 102... condenser, 103... evaporator, 105... piping, 110... air conditioning control device, 120... wired communication bus, A1... terminal, A2... terminal, B1... terminal, B2... terminal, L... axis line

Claims

1. An electric valve control device for controlling an electric valve having a valve body having a valve port, a stepping motor having a rotor and a stator, and a valve body that moves relative to the valve port when the rotor rotates, a rotation control unit that supplies a drive current to the stator to rotate the rotor; an acquisition unit that acquires a voltage generated in the stator due to rotation of the rotor; a determination unit that determines a relationship between a rotation load of the rotor and a magnitude of the drive current based on the voltage acquired by the acquisition unit, The rotation control unit is When the determination unit determines that the magnitude of the drive current is appropriate for the rotation load of the rotor, the magnitude of the drive current is maintained; When the determination unit determines that the magnitude of the drive current is large relative to the rotation load of the rotor, the magnitude of the drive current is reduced; 2. An electrically operated valve control device comprising: a drive current control unit for controlling a drive current of a rotor; a drive current control unit for controlling a drive current of the rotor;

2. The motor-operated valve control device according to claim 1 , wherein the determination unit determines the relationship based on a degree of difference between the waveform of the voltage acquired by the acquisition unit and a reference waveform of the voltage.

3. 3. The motor-operated valve control device according to claim 2, wherein the determination unit calculates a difference index value indicating a degree of difference between the voltage waveform and a reference voltage waveform, and determines the relationship based on a comparison result between the difference index value and a determination value.

4. the reference waveform of the voltage is a data table in which a time is associated with a reference voltage at the time, The acquisition unit acquires the voltage in time series, The determination unit, calculating an intermediate value that is a squared value of a difference between the voltage acquired by the acquisition unit at an acquisition time and the reference voltage associated with the time corresponding to the acquisition time in the data table; The motor-operated valve control device according to claim 3 , wherein the difference index value is calculated by adding up a plurality of the intermediate values ​​calculated using the voltages.

5. An electric valve control device for controlling an electric valve having a valve body having a valve port, a stepping motor having a rotor and a stator, and a valve body that moves relative to the valve port when the rotor rotates, a rotation control unit that supplies a drive current to the stator to rotate the rotor; an acquisition unit that acquires a current generated in the stator due to rotation of the rotor; a determination unit that determines a relationship between a rotation load of the rotor and a magnitude of the drive current based on the current acquired by the acquisition unit, The rotation control unit is When the determination unit determines that the magnitude of the drive current is appropriate for the rotation load of the rotor, the magnitude of the drive current is maintained; When the determination unit determines that the magnitude of the drive current is large relative to the rotation load of the rotor, the magnitude of the drive current is reduced; 2. An electrically operated valve control device comprising: a drive current control unit for controlling a drive current of a rotor; a drive current control unit for controlling a drive current of the rotor;

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

7. A method for controlling an electrically operated valve having a valve body having a valve port, a stepping motor having a rotor and a stator, and a valve body that moves relative to the valve port when the rotor rotates, comprising: Supplying a driving current to the stator to rotate the rotor; Acquire a voltage generated in the stator due to rotation of the rotor; determining a relationship between a rotation load of the rotor and a magnitude of the drive current based on the voltage; When it is determined that the magnitude of the drive current is appropriate for the rotation load of the rotor, the magnitude of the drive current is maintained; When it is determined that the magnitude of the drive current is large relative to the rotation load of the rotor, the magnitude of the drive current is reduced; A method for controlling a motor-operated valve, comprising the steps of: increasing the magnitude of the drive current when it is determined that the magnitude of the drive current is small relative to the rotational load of the rotor.

8. A method for controlling an electrically operated valve having a valve body having a valve port, a stepping motor having a rotor and a stator, and a valve body that moves relative to the valve port when the rotor rotates, comprising: Supplying a driving current to the stator to rotate the rotor; Acquire a current generated in the stator due to the rotation of the rotor; determining a relationship between a rotation load of the rotor and a magnitude of the drive current based on the current; When it is determined that the magnitude of the drive current is appropriate for the rotation load of the rotor, the magnitude of the drive current is maintained; When it is determined that the magnitude of the drive current is large relative to the rotation load of the rotor, the magnitude of the drive current is reduced; A method for controlling a motor-operated valve, comprising the steps of: increasing the magnitude of the drive current when it is determined that the magnitude of the drive current is small relative to the rotational load of the rotor.

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