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

Abstract

Provided is an electric valve control device, an electric valve device, and a control method of an electric valve, which can shorten the time required for initialization operation of an electric valve and suppress noise. An electric valve control device (70) inputs a pulse to a stepping motor (66) to rotate a rotor (41) in a first direction. The electric valve control device (70) acquires a voltage generated in a stator (60) due to the rotation of the rotor (41). Then, the electric valve control device (70) determines whether the electric valve (5) is in a first rotation restriction state in which the rotation of the rotor (41) in the first direction is restricted, based on the degree of difference between the waveform of the voltage and a reference waveform of the voltage.

Description

Technical Field

[0001] This invention relates to an electric valve control device, an electric valve device having an electric valve control device, and a method for controlling an electric valve. Background Technology

[0002] Patent Document 1 discloses an example of a conventional electric valve. Such an electric valve assembly is incorporated into the refrigeration cycle of an air conditioner. The electric valve has a valve body, a valve core, and a stepper motor for moving the valve core. The stepper motor has a rotor and a stator. When a pulse is input to the stepper motor, the rotor rotates. The valve core moves accordingly to the rotation of the rotor. When the rotor is in a reference position, a movable stop that rotates with the rotor abuts against a fixed stop fixed to the valve body, thereby restricting the rotor's rotation in a first direction.

[0003] The electric valve is controlled by an electric valve control device. During initialization, the electric valve control device inputs pulses to the stepper motor, causing the rotor to rotate in a first direction and position it at a reference position. The number of pulses input to the stepper motor is sufficient to allow the movable stop and fixed stop to abut (hereinafter referred to as the "initialization number"). When the rotor rotates in the first direction and the movable stop abuts the fixed stop, the rotor is positioned at the reference position.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: International Publication No. 2019 / 130928

[0007] The technical problem that the invention aims to solve

[0008] The electric valve control device inputs pulses to the stepper motor until the number of pulses input to the stepper motor reaches the initialization threshold. Therefore, the electric valve control device sometimes needs to input pulses even after the rotor is positioned at the reference position, resulting in a longer initialization time. Furthermore, when pulses are input to the stepper motor after the rotor is positioned at the reference position, the movable stop and the fixed stop repeatedly collide, generating noise. This noise is particularly pronounced when the rotor is close to the reference position before initialization, leading to a prolonged period of noise generation. Summary of the Invention

[0009] Therefore, the purpose of this invention is to provide an electric valve control device that can shorten the time required for the initialization action of an electric valve and suppress noise, an electric valve device having an electric valve control device, and a control method for an electric valve.

[0010] Technical means for solving technical problems

[0011] The inventors used multiple electric valves to measure the voltage generated in the stator (the voltage electromagnetically induced by the stator) due to the rotation of the rotor during initialization, and carefully examined the measurement results. As a result, the inventors discovered a difference between the waveform of the voltage before the rotor rotation was restricted by the stop mechanism and the waveform of the voltage after the rotor rotation was restricted by the stop mechanism, thus completing the present invention.

[0012] An electric valve control device controls an electric valve, the electric valve comprising: a valve body having a valve seat; a rotor rotatable relative to the valve body; a stator forming a stepper motor together with the rotor; a valve core opposite to the valve seat, the valve core moving toward the valve seat when the rotor rotates in a first direction; and a stop mechanism restricting the rotation of the rotor in the first direction when the rotor is in a reference position. The electric valve control device further comprises: a rotation control unit that inputs pulses to the stepper motor to rotate the rotor in the first direction; a voltage acquisition unit that acquires a voltage generated in the stator due to the rotation of the rotor; and a state determination unit that determines whether the electric valve is in a rotation restriction state where the rotation of the rotor in the first direction is restricted based on at least one of the following conditions: (i) the area of ​​the voltage waveform, (ii) the amplitude of a wave periodically observed in the voltage waveform, and (iii) the periodic occurrence of a new wave different from the wave periodically observed in the voltage waveform.

[0013] Preferably, when the state determination unit determines that the electric valve is in the rotation restriction state, the rotation control unit stops supplying the drive current to the stator.

[0014] Preferably, the stator has an A-phase stator and a B-phase stator, and when the rotation control unit supplies drive current to only one of the A-phase stator and the B-phase stator, the voltage acquisition unit acquires the voltage generated in the other of the A-phase stator and the B-phase stator.

[0015] Preferably, the valve core is opposite to the valve seat. When the rotor rotates in the first direction, the valve core is pressed toward the valve seat by a helical spring. The reference position is located at a position where the rotor has rotated further in the first direction compared to the valve-closed position where the valve core contacts the valve seat. When the state determination unit periodically observes the amplitude of the wave in the voltage waveform and the amplitude gradually decreases, it determines that the electric valve is in an intermediate state between the valve-closed position and the reference position.

[0016] An electric valve control device controls an electric valve, the electric valve comprising: a valve body having a valve seat; a rotor rotatable relative to the valve body; a stator forming a stepper motor together with the rotor; a valve core opposite to the valve seat, the valve core moving toward the valve seat when the rotor rotates in a first direction; and a stop mechanism restricting the rotation of the rotor in the first direction when the rotor is in a reference position. The electric valve control device further comprises: a rotation control unit that inputs pulses to the stepper motor to rotate the rotor in the first direction; a current acquisition unit that acquires the current generated in the stator due to the rotation of the rotor; and a state determination unit that determines whether the electric valve is in a rotation restriction state where the rotation of the rotor in the first direction is restricted based on at least one of the following conditions: (i) the area of ​​the waveform of the current, (ii) the amplitude of a wave periodically observed in the waveform of the current, and (iii) the periodic occurrence of a new wave different from the wave periodically observed in the waveform of the current.

[0017] The electric valve device includes the electric valve and the electric valve control device.

[0018] A method for controlling an electric valve, the electric valve comprising: a valve body having a valve seat; a rotor rotatable relative to the valve body; a stator constituting a stepper motor together with the rotor; a valve core opposite to the valve seat, the valve core moving toward the valve seat when the rotor rotates in a first direction; and a stop mechanism restricting the rotation of the rotor in the first direction when the rotor is in a reference position. The method further comprises supplying a drive current to the stator to cause the rotor to rotate in the first direction, acquiring a voltage generated in the stator due to the rotation of the rotor, and determining whether the electric valve is in a rotation-limited state where the rotation of the rotor in the first direction is restricted by the stop mechanism based on at least one of the following conditions: (i) the area of ​​the voltage waveform, (ii) the amplitude of a wave periodically observed in the voltage waveform, and (iii) the periodic occurrence of a new wave different from the wave periodically observed in the voltage waveform.

[0019] A method for controlling an electric valve, the electric valve comprising: a valve body having a valve seat; a rotor rotatable relative to the valve body; a stator constituting a stepper motor together with the rotor; a valve core opposite to the valve seat, the valve core moving toward the valve seat when the rotor rotates in a first direction; and a stop mechanism restricting the rotation of the rotor in the first direction when the rotor is in a reference position. The method further comprises supplying a drive current to the stator to cause the rotor to rotate in the first direction, acquiring a current generated in the stator due to the rotation of the rotor, and determining whether the electric valve is in a rotation-limited state where the rotation of the rotor in the first direction is restricted by the stop mechanism based on at least one of the following conditions: (i) the area of ​​the waveform of the current, (ii) the amplitude of a wave periodically observed in the waveform of the current, and (iii) the periodic occurrence of a new wave different from the wave periodically observed in the waveform of the current.

[0020] To achieve the above objectives, one aspect of the present invention relates to an electric valve control device that is,

[0021] An electric control device for an electric valve includes: a valve body having a valve seat; a rotor rotatable relative to the valve body; a stator forming a stepper motor together with the rotor; a valve core opposite to the valve seat, which moves toward the valve seat when the rotor rotates in a first direction; and a stop mechanism restricting rotation of the rotor in the first direction when the rotor is in a reference position.

[0022] A rotation control unit that inputs pulses to the stepper motor to cause the rotor to rotate in the first direction;

[0023] A voltage acquisition unit acquires the voltage generated in the stator due to the rotation of the rotor; and

[0024] The state determination unit determines whether the electric valve is in a first rotation restriction state in which the rotation of the rotor in the first direction is restricted, based on the degree of difference between the waveform of the voltage and the reference waveform of the voltage.

[0025] In this invention, preferably,

[0026] The reference waveform includes a first rotation-allowed state waveform, which is set based on the waveform of the voltage when the electric valve is in a state that allows rotation of the rotor in the first direction, and a pulse (hereinafter referred to as the "first direction pulse") is input to the stepper motor to rotate the rotor in the first direction.

[0027] The state determination unit calculates a difference index value and determines whether the electric valve is in the first rotation restriction state based on the comparison result between the difference index value and the difference determination value. The difference index value indicates the degree of difference between the waveform of the first rotation permission state and the waveform of the voltage obtained by the voltage acquisition unit corresponding to the input of the first direction pulse of the stepper motor.

[0028] In this invention, preferably,

[0029] The reference waveform includes a first rotation limiting state waveform, which is set based on the waveform of the voltage when the electric valve is in a state that limits the rotation of the rotor in the first direction, and a pulse (hereinafter referred to as the "first direction pulse") is input to the stepper motor to rotate the rotor in the first direction.

[0030] The state determination unit calculates a difference index value and determines whether the electric valve is in the first rotation restriction state based on the comparison result between the difference index value and the difference determination value. The difference index value indicates the degree of difference between the waveform of the first rotation restriction state and the waveform of the voltage obtained by the voltage acquisition unit corresponding to the input of the first direction pulse of the stepper motor.

[0031] In this invention, preferably,

[0032] The reference waveform includes:

[0033] A first rotation-allowing state waveform is set based on the waveform of the voltage when the electric valve is in a state that allows rotation of the rotor in the first direction, and a pulse (hereinafter referred to as the "first direction pulse") is input to the stepper motor to rotate the rotor in the first direction; and

[0034] The first rotation limiting state waveform is set based on the voltage waveform when a pulse in the first direction is input to the stepper motor when the electric valve is in a state that limits the rotation of the rotor in the first direction.

[0035] The state determination unit

[0036] A difference index value (hereinafter referred to as the "first rotational allowable state difference index value") is calculated, representing the degree of difference between the waveform of the first rotational allowable state and the waveform of the voltage acquired by the voltage acquisition unit corresponding to the input of the first direction pulse of the stepper motor.

[0037] A difference index value (hereinafter referred to as the "first rotation limit state difference index value") is calculated, representing the degree of difference between the waveform of the first rotation limit state and the waveform of the voltage obtained by the voltage acquisition unit corresponding to the input of the first direction pulse of the stepper motor.

[0038] Based on the comparison results of the first rotational allowable state difference index value and the first rotational allowable state difference judgment value and the comparison results of the first rotational restriction state difference index value and the first rotational restriction state difference judgment value, it is determined whether the electric valve is in the first rotational restriction state.

[0039] In this invention, preferably,

[0040] When the state determination unit determines that the electric valve is in the first rotation restriction state, the rotation control unit stops inputting the pulse to the stepper motor.

[0041] In this invention, preferably,

[0042] The reference waveform includes a second rotation-allowing state waveform, which is set based on the waveform of the voltage when the electric valve is in a state that allows rotation of the rotor in a second direction, and a pulse is input to the stepper motor causing the rotor to rotate in the second direction (hereinafter referred to as the "second direction pulse").

[0043] When the state determination unit determines that the electric valve is in the first rotation restriction state, the rotation control unit inputs the pulse to the stepper motor to cause the rotor to rotate in the second direction.

[0044] The state determination unit calculates a difference index value (hereinafter referred to as the "second rotational allowable state difference index value"), which represents the degree of difference between the waveform of the second rotational allowable state and the waveform of the voltage obtained by the voltage acquisition unit corresponding to the input of the second direction pulse of the stepper motor. Based on the comparison result between the second rotational allowable state difference index value and the second rotational allowable state difference determination value, it determines whether the electric valve is in a second rotational restriction state in which the rotation of the rotor in the second direction is restricted.

[0045] When the state determination unit determines that the electric valve is in the second rotation restriction state, the rotation control unit stops inputting the pulse to the stepper motor.

[0046] After the state determination unit determines that the electric valve is in the first rotation restriction state, when the number of pulses input to the stepper motor reaches the number of reversals, the rotation control unit inputs the number of pulses of the number of reversals to the stepper motor to make the rotor rotate in the first direction.

[0047] In this invention, preferably,

[0048] The reference waveform is a data table that sets the time for the first direction pulse and associates the time with the reference voltage at that time.

[0049] When the first direction pulse is input to the stepper motor, the voltage acquisition unit acquires the voltage in a timely manner.

[0050] When the voltage acquisition unit acquires the voltage at the acquisition time corresponding to the input of the first direction pulse, the state determination unit calculates a value obtained by squaring the difference between the voltage and the reference voltage (hereinafter referred to as the "first intermediate value"). The reference voltage is associated with the acquisition time corresponding to the acquisition time in the data table set for the first direction pulse input to the stepper motor.

[0051] The state determination unit adds up a plurality of the first intermediate values ​​to calculate the difference index value, and the plurality of the first intermediate values ​​are calculated using the voltage obtained by the voltage acquisition unit in correspondence with the input of the first direction pulse.

[0052] In this invention, preferably,

[0053] The reference waveform is a data table that sets the time for the second-direction pulse and associates the time with the reference voltage at that time.

[0054] When the second direction pulse is input to the stepper motor, the voltage acquisition unit acquires the voltage in a timely manner.

[0055] When the voltage acquisition unit acquires the voltage at the acquisition time corresponding to the input of the second direction pulse, the state determination unit calculates a value obtained by squaring the difference between the voltage and the reference voltage (hereinafter referred to as the "second intermediate value"). The reference voltage is associated with the acquisition time corresponding to the acquisition time in the data table set for the second direction pulse input to the stepper motor.

[0056] The state determination unit adds up a plurality of second intermediate values ​​to calculate the difference index value, and the plurality of second intermediate values ​​are calculated using the voltage obtained by the voltage acquisition unit in correspondence with the input of the second direction pulse.

[0057] In this invention, preferably,

[0058] The state determination unit adds up a plurality of the first intermediate values ​​to calculate the difference index value. The plurality of first intermediate values ​​are calculated using the voltage acquired by the voltage acquisition unit during a portion of the period from the start to the end of the first direction pulse.

[0059] The voltage component involved in the back electromotive force due to the inductance of the stator contained in the voltage during the period is smaller than the voltage component involved in the electromagnetic induction caused by the rotation of the rotor contained in the voltage.

[0060] In this invention, preferably,

[0061] The state determination unit adds up a plurality of second intermediate values ​​to calculate the difference index value. These plurality of second intermediate values ​​are calculated using the voltage acquired by the voltage acquisition unit during a portion of the period from the start to the end of the second direction pulse.

[0062] The voltage component involved in the back electromotive force due to the inductance of the stator contained in the voltage during the period is smaller than the voltage component involved in the electromagnetic induction caused by the rotation of the rotor contained in the voltage.

[0063] In this invention, preferably,

[0064] When the state determination unit determines that the electric valve is in the first rotation restriction state, a start pattern number is obtained based on the pattern number of the first direction pulse corresponding to the waveform of the voltage used for the determination.

[0065] When the rotation control unit rotates the rotor, which is located at the reference position, in the second direction, the pulse with the same pattern number as the starting pattern number is input.

[0066] In this invention, preferably,

[0067] Based on the waveforms of a plurality of voltages pre-acquired in the electric valve combined with the electric valve control device, the first rotation limit state waveform is set for the first direction pulse.

[0068] For each first direction pulse, a first rotation limit state waveform is set.

[0069] In this invention, preferably,

[0070] Based on the waveforms of the multiple voltages pre-acquired in the multiple electric valves, the first rotation limit state waveform is set for the first direction pulse.

[0071] For a given first direction pulse, set multiple first rotation limit state waveforms that are different from each other.

[0072] The number of first rotation limit state waveforms set for a first direction pulse is the same as the number of pulse patterns.

[0073] The first rotation restriction state waveform set for a first direction pulse is set based on the waveform of the voltage obtained from a plurality of electric valves that are different from each other at the time point corresponding to the pulse that restricts the rotation of the rotor in the first direction by the stop mechanism.

[0074] In this invention, preferably,

[0075] The stator has an A-phase stator and a B-phase stator.

[0076] When the rotation control unit supplies drive current to only one of the A-phase stator and the B-phase stator in accordance with the pulse input to the stepper motor, the voltage acquisition unit acquires the voltage generated by the other of the A-phase stator and the B-phase stator.

[0077] In this invention, preferably,

[0078] The valve core is opposite to the valve seat. When the rotor rotates in the first direction, the valve core is pressed towards the valve seat via a helical spring.

[0079] The reference position is located at a position where the rotor has rotated further in the first direction compared to the valve-closed position where the valve core contacts the valve seat.

[0080] In this invention, preferably,

[0081] To achieve the above objectives, another aspect of the present invention relates to an electric valve control device, which is...

[0082] An electric control device for an electric valve includes: a valve body having a valve seat; a rotor rotatable relative to the valve body; a stator forming a stepper motor together with the rotor; a valve core opposite to the valve seat, which moves toward the valve seat when the rotor rotates in a first direction; and a stop mechanism restricting rotation of the rotor in the first direction when the rotor is in a reference position.

[0083] A rotation control unit that inputs pulses to the stepper motor to cause the rotor to rotate in the first direction;

[0084] A current acquisition unit acquires the current generated in the stator due to the rotation of the rotor; and

[0085] The state determination unit determines whether the electric valve is in a first rotation restriction state in which the rotation of the rotor in the first direction is restricted, based on the degree of difference between the waveform of the current and the reference waveform of the current.

[0086] To achieve the above objectives, another embodiment of the present invention relates to an electric valve device.

[0087] It has the electric valve and the electric valve control device.

[0088] To achieve the above objectives, another embodiment of the present invention relates to a method for controlling an electric valve, which is as follows:

[0089] The electric valve comprises: a valve body having a valve seat; a rotor rotatable relative to the valve body; a stator forming a stepper motor together with the rotor; a valve core opposite to the valve seat, which moves toward the valve seat when the rotor rotates in a first direction; and a stop mechanism restricting rotation of the rotor in the first direction when the rotor is in a reference position.

[0090] A pulse is input to the stepper motor to cause the rotor to rotate in the first direction.

[0091] Obtain the voltage generated in the stator due to the rotation of the rotor.

[0092] The degree of difference between the waveform of the voltage and the reference waveform of the voltage is used to determine whether the electric valve is in a first rotation restriction state in which the rotation of the rotor in the first direction is restricted.

[0093] To achieve the above objectives, another embodiment of the present invention relates to a method for controlling an electric valve, which is as follows:

[0094] The electric valve comprises: a valve body having a valve seat; a rotor rotatable relative to the valve body; a stator forming a stepper motor together with the rotor; a valve core opposite to the valve seat, which moves toward the valve seat when the rotor rotates in a first direction; and a stop mechanism restricting rotation of the rotor in the first direction when the rotor is in a reference position.

[0095] A pulse is input to the stepper motor to cause the rotor to rotate in the first direction.

[0096] To obtain the current generated in the stator due to the rotation of the rotor.

[0097] The degree of difference between the waveform of the current and the reference waveform of the current is used to determine whether the electric valve is in a first rotation restriction state in which the rotation of the rotor in the first direction is restricted.

[0098] The effects of the invention

[0099] According to one aspect of the invention, pulses are input to a stepper motor to rotate the rotor in a first direction. The voltage generated in the stator due to the rotor's rotation is acquired. Then, based on the degree of difference between the voltage waveform and a reference voltage waveform, it is determined whether the electric valve is in a first rotation-limiting state where the rotor's rotation in the first direction is restricted.

[0100] According to another aspect of the invention, pulses are input to a stepper motor to rotate the rotor in a first direction. The current generated in the stator due to the rotor's rotation is acquired. Then, based on the degree of difference between the current waveform and a reference current waveform, it is determined whether the electric valve is in a first rotation-limiting state where the rotor's rotation in the first direction is restricted.

[0101] Therefore, for an electrically operated valve that is functioning normally, when the valve is determined to be in the first rotation restriction state, the rotor is located at a reference position. Thus, when the valve is determined to be in the first rotation restriction state, stopping the rotor's rotation in the first direction can shorten the time required for initialization. Furthermore, after the rotor is positioned at the reference position, prolonged noise generation can be suppressed. Additionally, the valve's state is determined based on the degree of waveform difference. Therefore, compared to structures that determine the valve's state based on waveform area or maximum waveform amplitude, the valve's state can be determined with even higher accuracy. Attached Figure Description

[0102] Figure 1 This is a block diagram of an air conditioning system with an electric valve device.

[0103] Figure 2 yes Figure 1 A cross-sectional view of an electric valve device.

[0104] Figure 3 It means Figure 2 A diagram of the valve shaft retainer of the electric valve device.

[0105] Figure 4 yes Figure 2 A side view of the guide bushing of the electric valve device.

[0106] Figure 5 It means Figure 2 A diagram showing the stop component of an electric valve device.

[0107] Figure 6 yes Figure 2 A top view of the valve shaft cage, stop components, rotor, and stator of the electric valve device.

[0108] Figure 7 This is an explanation Figure 2 The diagram shows the computer, motor driver, and stepper motor of the electric valve device.

[0109] Figure 8 It is a diagram that schematically shows the positional relationship between the rotor's magnetic poles and the stator's pole teeth (when pulse P[1] is input).

[0110] Figure 9 It is a diagram that schematically shows the positional relationship between the rotor's magnetic poles and the stator's pole teeth (when pulse P[2] is input).

[0111] Figure 10 It is a diagram that schematically shows the positional relationship between the rotor's magnetic poles and the stator's pole teeth (when pulse P[3] is input).

[0112] Figure 11 It is a diagram that schematically shows the positional relationship between the rotor's magnetic poles and the stator's pole teeth (when pulse P[4] is input).

[0113] Figure 12 It is a diagram that schematically shows the positional relationship between the rotor's magnetic poles and the stator's pole teeth (when pulse P[5] is input).

[0114] Figure 13 It is a diagram that schematically shows the positional relationship between the rotor's magnetic poles and the stator's pole teeth (when pulse P[6] is input).

[0115] Figure 14 It is a diagram that schematically shows the positional relationship between the rotor's magnetic poles and the stator's pole teeth (when pulse P[7] is input).

[0116] Figure 15 It is a diagram that schematically shows the positional relationship between the rotor's magnetic poles and the stator's pole teeth (when pulse P[8] is input).

[0117] Figure 16 This is a diagram illustrating an example of the waveform of the voltage generated in the stator by the rotation of the rotor during the initialization operation of an electric valve device.

[0118] Figure 17 It's enlarged. Figure 16 A diagram of a portion of the voltage waveform.

[0119] Figure 18 It's enlarged. Figure 16 Another part of the voltage waveform is shown in the diagram.

[0120] Figure 19 It means Figure 2 A flowchart illustrating an example of the initialization actions performed by a computer in an electric valve device.

[0121] Figure 20 This is a diagram showing an example of a standard waveform (the waveform of the first rotational permissible state) containing voltage.

[0122] Figure 21 This is a diagram showing an example of a standard waveform containing voltage (first rotational limit state waveform #1).

[0123] Figure 22 This is a diagram showing an example of a standard waveform containing voltage (first rotational limit state waveform #2).

[0124] Figure 23 This is a diagram showing an example of a standard waveform containing voltage (first rotational limit state waveform #3).

[0125] Figure 24 This is a diagram showing an example of a standard waveform containing voltage (first rotational limit state waveform #4).

[0126] Figure 25 This is a diagram showing an example of a standard waveform containing voltage (first rotational limit state waveform #5).

[0127] Figure 26 This is a diagram showing an example of a standard waveform containing voltage (first rotational limit state waveform #6).

[0128] Figure 27 This is a diagram showing an example of a standard waveform containing voltage (first rotational limit state waveform #7).

[0129] Figure 28 This is a diagram showing an example of a standard waveform containing voltage (first rotational limit state waveform #8).

[0130] Figure 29 This is a diagram of an example of a data table (first rotational permissible state table) representing the standard waveform of voltage.

[0131] Figure 30 This is a diagram showing examples of voltage waveforms and reference voltage waveforms.

[0132] Figure 31 This is a flowchart illustrating an example 1 of the operation of an electric valve control device according to an embodiment of the present invention.

[0133] Figure 32 This is a flowchart illustrating an example 2 of the operation of an electric valve control device according to an embodiment of the present invention.

[0134] Figure 33 This is a flowchart illustrating an operational example 2 of the electric valve control device according to an embodiment of the present invention (continued). Figure 32 ). Detailed Implementation

[0135] The following is for reference Figures 1 to 19 The electric valve device will be described. The electric valve device 1 is used, for example, as a flow control valve to control the refrigerant flow in the refrigeration cycle of an air conditioner.

[0136] Figure 1 This is a block diagram of an air conditioning system with an electric valve device. Figure 2 yes Figure 1 A cross-sectional view of an electric valve assembly. Figure 2 The image shows, schematically, the stator and the electric valve control device. Figure 3 It means Figure 2 A diagram of the valve shaft retainer of the electric valve device. Figure 3 (A) is a perspective view of the valve shaft cage. Figure 3 (B) is a top view of the valve shaft cage. Figure 4 yes Figure 2 A side view of the guide bushing of the electric valve device. Figure 5 It means Figure 2 A diagram showing the stop component of an electric valve device. Figure 5 (A) is a three-dimensional view of the stop component. Figure 5 (B) is a top view of the stop component.

[0137] Figure 6 yes Figure 2 A top view of the valve shaft cage, stop components, rotor, and stator of the electric valve device. Figure 6 In the diagram, the stator is schematically represented. Additionally, in... Figure 6 The image shows the magnetic poles of the rotor. Figure 7 This is an explanation Figure 2 The diagram shows the computer, motor driver, and stepper motor of the electric valve device. Figure 7 (A) schematically illustrates the connection of a computer, motor driver, and stepper motor in an electric valve control device. Figure 7 (B) represents an example of the pulse corresponding to the drive current supplied by the motor driver to the stator. Figures 8-15 It is a diagram that schematically shows the positional relationship between the rotor's magnetic poles and the stator's pole teeth. Figures 8-15 Corresponding to the input of pulses P[1] to P[8]. Figures 8-15 In the diagram, the stator is schematically represented. Additionally, in... Figures 8-15 The image shows the magnetic poles of the rotor. Figure 16This is a diagram illustrating an example of the waveform of the voltage generated in the stator by the rotation of the rotor during the initialization operation of an electric valve device. Figure 17 It's enlarged. Figure 16 A graph of a portion of the voltage waveform (during period T1). Figure 18 It's enlarged. Figure 16 The diagram shows another part of the voltage waveform (during period T7). Figure 19 It means Figure 2 A flowchart illustrating an example of the initialization actions performed by a computer in an electric valve device.

[0138] Figure 1 This illustrates an example of an air conditioning system 100 installed in a vehicle. The air conditioning system 100 includes a compressor 101, a condenser 102, an electric valve device 1 (electric valve 5), and an evaporator 103, connected sequentially via piping 105. The electric valve device 1 is an expansion valve. The air conditioning system 100 includes an air conditioning control device 110. The air conditioning control device 110 is connected to the electric valve device 1 in a manner capable of communicating with it. The air conditioning control device 110 uses the electric valve device 1 to control the flow rate of refrigerant flowing in the piping 105.

[0139] like Figure 2 As shown, the electric valve device 1 has an electric valve 5 and an electric valve control device 70.

[0140] The electric valve 5 has a valve body 10, a housing 20, a valve core 30, a drive mechanism 40, and a stator 60.

[0141] The valve body 10 has a main component 11 and a connecting component 13. The main component 11 has a cylindrical shape. The main component 11 has a valve chamber 14. A first conduit 15 and a second conduit 16 engage with the main component 11. The first conduit 15 is aligned in a direction orthogonal to the axis L. Figure 2 The second conduit 16 is configured in the left-right direction and is connected to the valve chamber 14. The second conduit 16 is along the axis L (…). Figure 2 The valve is configured (vertically and vertically) and connected to the valve chamber 14 via a valve port 17. The valve port 17 is surrounded by an annular valve seat 18 in the valve chamber 14. The main body component 11 has a circular fitting hole 11a. The fitting hole 11a is disposed on the upper end face of the main body component 11. The inner circumferential surface of the fitting hole 11a has a... Figure 2 The center faces left-side plane 11d. A through hole 11b communicating with valve chamber 14 is formed on the bottom surface of fitting hole 11a. Connecting member 13 has an annular plate shape. The inner periphery of connecting member 13 engages with the upper end of main body member 11. Main body member 11 and connecting member 13 are made of metals such as aluminum alloy, stainless steel, and brass.

[0142] The housing 20 is made of stainless steel or other metal. The housing 20 has a cylindrical shape. The lower end of the housing 20 is open and the upper end is closed. The lower end of the housing 20 is engaged with the outer periphery of the connecting member 13.

[0143] The valve core 30 has a first shaft portion 31, a second shaft portion 32, and a valve portion 33. The first shaft portion 31 is cylindrical. The second shaft portion 32 is cylindrical. 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 of the first shaft portion 31. The valve core 30 has a stepped portion 34 that is an upward-facing annular plane. The stepped portion 34 is disposed at the connection point between the first shaft portion 31 and the second shaft portion 32. The valve portion 33 has a generally conical shape whose diameter decreases from top to bottom. The valve portion 33 is coaxially connected to the lower end of the first shaft portion 31. The valve portion 33 is disposed at a valve port 17. A variable throttling portion is formed between the valve portion 33 and the valve port 17. The valve portion 33 is disposed opposite to a valve seat 18, and when the valve portion 33 contacts the valve seat 18, the valve port 17 is closed.

[0144] The drive mechanism 40 moves the valve core 30 in the vertical direction (axis L direction). The valve port 17 opens and closes as a result of the movement of the valve core 30. The drive mechanism 40 includes a rotor 41, a valve shaft retainer 42, a guide bushing 43, a stop member 44, and a fixing member 45.

[0145] The rotor 41 has a cylindrical shape. The outer diameter of the rotor 41 is slightly smaller than the inner diameter of the housing 20. The rotor 41 is disposed inside the housing 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 circumferential 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 alternately arranged at equal angular intervals in the circumferential direction. In the electric valve device 1, 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.

[0146] Figure 3The valve shaft retainer 42 is indicated. The valve shaft retainer 42 has a cylindrical shape. The lower end of the valve shaft retainer 42 is open, and the upper end is closed. The valve shaft retainer 42 is fitted into the fitting hole 41a of the rotor 41. The valve shaft retainer 42 rotates together with the rotor 41. A movable stop 42s, which is a radially outward protrusion, is disposed at the lower end of the outer peripheral surface of the valve shaft retainer 42. A shaft hole 42b is formed in the upper wall portion 42a of the valve shaft retainer 42. The second shaft portion 32 of the valve core 30 is disposed in the shaft hole 42b in a manner movable in the axial direction L. A washer 46 is disposed on the lower surface of the upper wall portion 42a of the valve shaft retainer 42. A valve closing spring 47 is disposed between the washer 46 and the stepped portion 34 of the valve core 30. The valve closing spring 47 is a helical spring, and the valve core 30 is pressed towards the valve seat 18. An internal thread 42c is formed on the inner peripheral surface of the valve shaft retainer 42. The movable stop 42s is fixed relative to the rotor 41.

[0147] Figure 4 The guide bushing 43 is indicated. The guide bushing 43 has a base 43a and a support 43b. The base 43a has a cylindrical shape. The support 43b has a cylindrical shape. The outer peripheral surface of the base 43a has a plane 43d. The base 43a is pressed into the fitting hole 11a of the main body component 11, and the plane 43d contacts the plane 11d of the fitting hole 11a. Thus, the central axis of the main body component 11 and the central axis of the guide bushing 43 coincide on the axis L, and the guide bushing 43 is correctly positioned relative to the main body component 11 about the axis L. The outer diameter of the support 43b is smaller than the outer diameter of the base 43a. The inner diameter of the support 43b is the same as the inner diameter of the base 43a. The support 43b is coaxially connected to the upper end of the base 43a. An external thread 43c is formed on the outer peripheral surface of the support 43b. The external thread 43c engages with the internal thread 42c of the valve shaft retainer 42. The first shaft portion 31 of the valve core 30 is disposed inside the guide bushing 43. The guide bushing 43 supports the valve core 30 so that it can move in the direction of the axis L.

[0148] Figure 5 The stop member 44 is indicated. The stop member 44 has a stop body 44a. The stop body 44a has a cylindrical shape. An internal thread 44c is formed on the inner circumferential surface of the stop body 44a. A fixing stop 44s, which is a protrusion projecting radially outward, is disposed on the outer circumferential surface of the stop body 44a. The internal thread 44c engages with the external thread 43c until the stop body 44a abuts against the base 43a of the guide bushing 43. Thus, the stop member 44 is fixed to the guide bushing 43. The fixing stop 44s is fixed relative to the valve body 10.

[0149] The fixing member 45 has a fixing portion 45a and a flange portion 45b. The fixing portion 45a has a stepped cylindrical shape. A second shaft portion 32 of the valve core 30 is disposed inside the fixing portion 45a. The fixing portion 45a is welded to the second shaft portion 32. The flange portion 45b is connected to the lower end of the fixing portion 45a. A return spring 48 is disposed on the outside of the fixing member 45. The return spring 48 is a helical spring.

[0150] The stator 60 has a cylindrical shape. The stator 60 has an A-phase stator 61 and a B-phase stator 62.

[0151] The A-phase stator 61 has multiple claw-shaped pole teeth 61a and 61b on its inner circumference. The tips of pole teeth 61a face downwards, and the tips of pole teeth 61b face upwards. The pole teeth 61a and 61b are arranged alternately at equal angular intervals in the circumferential direction. In the electric valve device 1, the A-phase stator 61 has, for example, 12 pole teeth 61a and 12 pole teeth 61b. The angle between adjacent pole teeth 61a and 61b is 15 degrees. When the coil 61c of the A-phase stator 61 is energized, the pole teeth 61a and 61b become magnetic poles with opposite polarities.

[0152] The B-phase stator 62 has multiple claw-shaped pole teeth 62a and 62b on its inner circumference. The tips of pole teeth 62a face downwards, and the tips of pole teeth 62b face upwards. The pole teeth 62a and 62b are arranged alternately at equal angular intervals in the circumferential direction. In the electric valve device 1, the B-phase stator 62 has, for example, 12 pole teeth 62a and 12 pole teeth 62b. The angle between adjacent pole teeth 62a and 62b is 15 degrees. When the coil 62c of the B-phase stator 61 is energized, the pole teeth 62a and 62b become magnetic poles with opposite polarities.

[0153] Phase A stator 61 and phase B stator 62 are coaxially arranged. Phase A stator 61 is in contact with phase B stator 62. When viewed from the axis L, the angle between the adjacent pole teeth 61a of phase A stator 61 and the pole teeth 62a of phase B stator 62 is 7.5 degrees. That is, phase B stator 62 is in a position where the pole teeth 61a and 62a are arranged side by side in the axis L direction, rotated 7.5 degrees relative to phase A stator about the axis L. Figure 7 As shown in (A), the terminals A1 and A2 of the coil 61c of the A-phase stator 61 and the terminals B1 and B2 of the coil 62c of the B-phase stator 62 are connected to the electric valve control device 70 (motor driver 77).

[0154] A housing 20 is disposed inside the stator 60. A rotor 41 is disposed inside the housing 20. The stator 60 and the rotor 41 together constitute a stepper motor 66.

[0155] The rotor 41 is rotated by inputting pulse P (P[1]~P[8]) into the stepper motor 66. Specifically, the rotor 41 is rotated by supplying a drive current corresponding to pulse P to the stator 60 of the stepper motor 66. In this specification, "inputting pulse P into the stepper motor 66" and "supplying a drive current corresponding to pulse P to the stator 60 of the stepper motor 66" have the same meaning.

[0156] Figure 7 The pulses P[1] to P[8] shown in (B) are sequentially input into the stepper motor 66. The combination of the drive current supplied to the A-phase stator 61 and the drive current supplied to the B-phase stator 62 is different for each pulse P. The number of combinations is 8, which is called the number of patterns of pulse P. The “pattern” is also called the “switching mode”. The numbers (1 to 8) of pulses P[1] to P[8] are the pattern numbers used for a specific pulse P[1] to P[8]. Figures 8-15 An example illustrating the positional relationship between rotor 41 and stator 60 when pulses P[1] to P[8] are input. Figures 8-15 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), black dots are marked on the reference pole tooth 61a and the magnetic pole (S pole) of the reference rotor 41.

[0157] When the rotor 41 is oriented in the first direction ( Figures 8-15 When the rotor 41 rotates clockwise, pulses P are cyclically input into the stepper motor 66 in ascending order (pulse P[1] to P[8]). When the rotor 41 rotates in the first direction, the rotor 41 and the valve shaft holder 42 move downwards due to the thread feed action of the internal thread 42c of the valve shaft holder 42 and the external thread 43c of the guide bushing 43. The rotor 41 (valve shaft holder 42) presses the valve core 30 downwards via the valve closing spring 47. The valve core 30 moves downwards and the valve part 33 contacts the valve seat 18. At this time, the position of the rotor 41 is the valve closed position Rc. When the rotor 41 is rotated further in the first direction from this state, the valve closing spring 47 is compressed and the rotor 41 moves further downwards. The valve core 30 does not move downwards. Then, when the movable stop 42s of the valve shaft holder 42 contacts the fixed stop 44s of the stop member 44, the rotation of the rotor 41 in the first direction is restricted. At this time, the rotor 41 is at the reference position Rx.

[0158] The rotor 41 is directed in a second direction opposite to the first direction. Figures 8-15When the rotor 41 rotates counterclockwise, pulses P are cyclically input into the stepper motor 66 in descending order (pulse P[8] to P[1]). When the rotor 41 rotates in the second direction, the rotor 41 and the valve shaft holder 42 move upward through the thread feed action of the internal thread 42c of the valve shaft holder 42 and the external thread 43c of the guide bushing 43. The rotor 41 (valve shaft holder 42) presses the fixing member 45 upward. The valve core 30 moves upward together with the fixing member 45, thereby separating the valve core 30 from the valve seat 18. The position of the rotor 41 when the flow rate of the fluid in the valve port 17 (the opening degree of the valve port 17) is a specified set value under a specified flow measurement environment is set as the valve open position Ro. The set value is appropriately set according to the structure, purpose, etc. of the electric valve device 1.

[0159] In the electric valve 5, the central axis of each of the valve port 17, valve seat 18, housing 20, valve core 30, rotor 41, valve shaft retainer 42, guide bushing 43, and stator 60 (A-phase stator 61 and B-phase stator 62) is aligned with the axis L.

[0160] The electric valve control device 70 has a base plate 71 on which multiple electronic components (not shown) are mounted. For example... Figure 1 As shown, the electric valve control device 70 includes a non-volatile memory 75, a communication device 76, a motor driver 77, and a computer 80. The electric valve control device 70 controls the electric valve 5 based on commands from the air conditioning control device 110.

[0161] Non-volatile memory 75 stores data that needs to be retained even when the power is cut off. Non-volatile memory 75 is, for example, EEPROM or flash memory.

[0162] The communication device 76 is connected to the air conditioning control device 110 via a wired communication bus 120 in a communicative manner. The air conditioning system 100 may employ communication methods such as Local Interconnect Network (LIN) or Controller Area Network (CAN). Alternatively, the communication device 76 may also be connected to the air conditioning control device 110 in a wireless communication manner.

[0163] The motor driver 77 supplies drive current to the stepper motor 66 based on pulse P input from the computer 80. For example... Figure 7 As shown in (A), the motor driver 77 is connected to terminals A1 and A2 of the coil 61c of phase A stator 61 and terminals B1 and B2 of the coil 62c of phase B stator 62. Figure 7 (B) represents an example of the correspondence between pulse P and the drive circuit supplied by motor driver 77. Figure 7In (B), (+) indicates that a drive current is supplied from terminal A1 to terminal A2 or from terminal B1 to terminal B2, (﹣) indicates that a drive current is supplied from terminal A2 to terminal A1 or from terminal B2 to terminal B1, and (0) indicates that no drive current is supplied.

[0164] When a pulse P[1] is input from computer 80, motor driver 77 supplies a driving current (+) from terminal A1 to terminal A2 to coil 61c, and does not supply a driving current (0) to coil 62c.

[0165] When a pulse P[2] is input from the computer 80, the motor driver 77 supplies a driving current (+) from terminal A1 to terminal A2 to the coil 61c and a driving current (+) from terminal B1 to terminal B2 to the coil 62c.

[0166] When a pulse P[3] is input from computer 80, motor driver 77 does not supply driving current (0) to coil 61c, but supplies driving current (+) from terminal B1 to terminal B2 to coil 62c.

[0167] When a pulse P[4] is input from the computer 80, the motor driver 77 supplies a driving current (-) from terminal A2 to terminal A1 to the coil 61c, and a driving current (+) from terminal B1 to terminal B2 to the coil 62c.

[0168] When a pulse P[5] is input from computer 80, motor driver 77 supplies a driving current (﹣) from terminal A2 to terminal A1 to coil 61c, and does not supply a driving current (0) to coil 62c.

[0169] When a pulse P[6] is input from the computer 80, the motor driver 77 supplies a driving current (﹣) from terminal A2 to terminal A1 to the coil 61c, and a driving current (﹣) from terminal B2 to terminal B1 to the coil 62c.

[0170] When a pulse P[7] is input from computer 80, motor driver 77 does not supply driving current (0) to coil 61c, but supplies driving current (﹣) from terminal B2 to terminal B1 to coil 62c.

[0171] When a pulse P[8] is input from the computer 80, the motor driver 77 supplies a driving current (+) from terminal A1 to terminal A2 to the coil 61c, and a driving current (-) from terminal B2 to terminal B1 to the coil 62c.

[0172] Computer 80 is a microcomputer with a built-in device that integrates a CPU, ROM, RAM, input / output connectors, and an A / D converter into a single component. Computer 80 may also include non-volatile memory 75, a communication device 76, and a motor driver 77. Computer 80 functions as a rotation control unit 81, a voltage acquisition unit 82, and a status determination unit 83 by executing programs stored in ROM through the CPU.

[0173] The rotation control unit 81 inputs pulse P to the stepper motor 66 to rotate the rotor 41 in a first direction or a second direction. Specifically, the rotation control unit 81 inputs pulses P[1] to P[8] to the motor drive unit 77 based on a command received from the air conditioning control device 110. The motor drive unit 77 supplies drive current to the coil 61c of phase A stator 61 and the coil 62c of phase B stator 62 according to the input pulses P[1] to P[8].

[0174] The voltage acquisition unit 82 acquires the voltage generated in the stator 60 due to the rotation of the rotor 41 (the voltage electromagnetically induced by the stator 60). Specifically, when the rotation control unit 81 supplies drive current only to the coil 61c of the A-phase stator 61 according to pulses P[1] and P[5], the voltage acquisition unit 82 sequentially acquires the voltage VB generated between terminals B1 and B2 of the coil 62c of the B-phase stator 62. When the rotation control unit 81 supplies drive current only to the coil 62c of the B-phase stator 62 according to pulses P[3] and P[7], the voltage acquisition unit 82 sequentially acquires the voltage VA generated between terminals A1 and A2 of the coil 61c of the A-phase stator 61. When the rotation control unit 81 supplies drive current to both coil 61c and coil 62c according to pulses P[2], P[4], P[6], and P[8], the voltage acquisition unit 82 does not acquire voltages VA and VB. Alternatively, when the rotation control unit 81 supplies drive current to coils 61c and 62c according to pulses P[1] to P[8], the voltage acquisition unit 82 sequentially acquires voltages VA and VB. In this case, the voltage acquisition unit 82 separates the electromagnetically induced voltage component from the voltage generated between terminals A1 and A2, and uses this voltage component as voltage VA. The voltage acquisition unit 82 separates the electromagnetically induced voltage component from the voltage generated between terminals B1 and B2, and uses this voltage component as voltage VB. The sequentially acquired voltage VA is the waveform of voltage VA. The sequentially acquired voltage VB is the waveform of voltage VB.

[0175] During the operation of positioning the rotor 41 at the reference position Rx (hereinafter referred to as the "initialization operation"), the state determination unit 83 determines the state of the electric valve 5 based on the waveforms of the voltage VA and voltage VB acquired by the voltage acquisition unit 82. The electric valve 5 has a rotation-allowing state Sp and a rotation-limiting state Sr. The rotation-allowing state Sp is the state in which the rotor 41 has not reached the reference position Rx and rotation of the rotor 41 in the first direction is allowed. The rotation-limiting state Sr is the state in which the rotor 41 has reached the reference position Rx and the movable stop 42s abuts against the fixed stop 44s, thus limiting the rotation of the rotor 41 in the first direction. The movable stop 42s and the fixed stop 44s constitute the stop mechanism 49.

[0176] In this specification, a "waveform" refers to the time-varying change of a physical quantity (voltage) at a fixed point. When visualizing a "waveform," it is displayed on a coordinate plane with the physical quantity as the vertical axis and time as the horizontal axis. Additionally, a "waveform" also includes invisible structures such as the RAM of the computer 80 and data tables in the non-volatile memory 75 that associate and store physical quantity data with time data. Furthermore, the "area of ​​the waveform" refers to the area enclosed by the waveform and the horizontal axis when the waveform is displayed on a coordinate plane with the physical quantity as the vertical axis and time as the horizontal axis corresponding to the physical quantity 0.

[0177] Figures 16-18 This shows an example of the waveforms of voltage VA and voltage VB measured during the initialization operation. During periods T1 to T9, pulses P[1] to P[8] are input to the stepper motor 66 in ascending order. Although in Figure 16 It is not recorded, but the waveforms of voltage VA and voltage VB before period T1 are the same as (including substantially the same) as the waveforms of voltage VA and voltage VB during period T1. In electric valve device 1, for example, the period of pulse P is 8ms, and a period T is 64ms. At time tc, valve core 30 contacts valve seat 18, and rotor 41 is positioned in the closed position Rc. At time tx, movable stop 42s abuts against fixed stop 44s, and rotor 41 is positioned in the reference position Rx. Rotation of rotor 41 in the first direction is permitted before time tx and restricted after time tx.

[0178] The waveform of voltage VA includes A waves (a1~a9), B waves (b1~b9), C waves (c1~c9), D waves (d1~d9), and E waves (e7~e9). A waves and B waves are negative voltage (-V) waves observed periodically throughout all periods T. C waves and D waves are positive voltage (+V) waves observed periodically throughout all periods T. E waves are positive voltage (+V) waves observed periodically after time tx. Furthermore, each wave has an amplitude greater than a specified magnitude.

[0179] When the area of ​​the waveform (including the waveforms of C and D waves) in the interval corresponding to pulse P[7] in the period T1~T9 is set as SA1~SA9, the area SA6~SA9 in the period T6~T9 after time tx is smaller than the area SA1~SA5 in the period T1~T5 before time tx.

[0180] In addition, the D wave is a positive voltage wave with a large amplitude before time tx (d1~d5) and a positive voltage wave with a small amplitude after time tx (d6~d9).

[0181] Furthermore, the E-wave was not observed before time tx, but was periodically observed after time tx (e7~e9). That is, the E-wave is a new wave that is different from the wave that is periodically observed in all periods T, and it appears periodically after time tx.

[0182] The waveform of voltage VB includes F-wave (f1~f9), G-wave (g1~g9), H-wave (h1~h9), J-wave (j1~j9), K-wave (k1~k9), and M-wave (m7~m9). F-wave and G-wave are positive voltage (+V) waves observed periodically throughout all periods T. H-wave, J-wave, and K-wave are negative voltage (-V) waves observed periodically throughout all periods T. M-wave is a positive voltage (+V) wave observed periodically after time tx. Furthermore, each wave has an amplitude greater than a specified magnitude.

[0183] When the area of ​​the waveform (including the waveforms of F wave, G wave and H wave) in the interval corresponding to pulse P[1] in the period T1~T9 is set as SB1~SB9, the area SB7~SB9 in the period T7~T9 after time tx is smaller than the area SB1~SB6 in the period T1~T6 before time tx.

[0184] Furthermore, the G wave is a positive voltage wave with a large amplitude before time tx (g1 to g6), and a positive voltage wave with a small amplitude after time tx (g7 to g9). In addition, the G wave combines with the H wave to form a single wave (g7 to g9) after time tx.

[0185] In addition, the K wave is a negative voltage wave with a smaller amplitude before time tx (k1~k5) and a negative voltage wave with a larger amplitude after time tx (k7~k9).

[0186] Furthermore, the M-wave was not observed before time tx, but was periodically observed after time tx (m7~m9). That is, the M-wave is a new wave that is different from the wave that is periodically observed in all periods T, and it appears periodically after time tx.

[0187] Therefore, the waveforms of voltage VA and voltage VB have the following differences before and after time tx.

[0188] (i) The area of ​​the waveform in the period T after time tx is smaller than the area of ​​the waveform in the period T before time tx.

[0189] (ii) The amplitude of the wave after time tx is different from the amplitude of the wave before time tx.

[0190] (iii) Waves that are different from those observed before time tx appear periodically after time tx.

[0191] Therefore, by detecting at least one of the phenomena shown in (i) to (iii) above in the waveform of voltage VA or voltage VB, it can be determined that time tx has been exceeded, that is, the rotor 41 has reached the reference position Rx and the electric valve 5 has entered the rotation restriction state Sr.

[0192] During the initialization operation, if none of the phenomena described in (i) to (iii) above are detected in the waveforms of voltage VA and voltage VB acquired by voltage acquisition unit 82, state determination unit 83 determines that electric valve 5 is in the rotation-allowed state Sp. If at least one of the phenomena described in (i) to (iii) above is detected, state determination unit 83 determines that electric valve 5 is in the rotation-restricted state Sr. Then, when state determination unit 83 determines that it is in the rotation-restricted state Sr, rotation control unit 81 stops inputting pulses P[1] to P[8] to the stepper motor 66 and ends the initialization operation.

[0193] Alternatively, when two or more of the phenomena described in (i) to (iii) above are detected, the state determination unit 83 determines that the electric valve 5 is in the rotation restriction state Sr. In this case, when the state determination unit 83 does not determine that the electric valve 5 is in the rotation restriction state Sr, it determines that the electric valve 5 is in the rotation permission state Sp.

[0194] Next, refer to Figure 19 An example of the operation of the electric valve control device 70 will be described.

[0195] When the electric valve control device 70 (specifically, the computer 80) receives an initialization command from the air conditioning control device 110 (S110), it begins to input the ascending pulses P[1] to P[8] of the stepper motor 66 (S120). As a result, the initialization operation begins, the stator 60 is supplied with the drive current corresponding to the pulses P[1] to P[8], and the rotor 41 rotates in the first direction.

[0196] When the rotor 41 rotates in the first direction, the electric valve control device 70 sequentially acquires the voltage VA generated between terminals A1 and A2 of the coil 61c of the A-phase stator 61 and the voltage VB generated between terminals B1 and B2 of the coil 62c of the B-phase stator 62 (S130). That is, the electric valve control device 70 acquires the waveforms of voltage VA and voltage VB. Specifically, when driving current is supplied only to the coil 61c of the A-phase stator 61 according to pulses P[1] and P[5], the electric valve control device 70 acquires the voltage VB generated between terminals B1 and B2 of the coil 62c of the B-phase stator 62. In addition, when driving current is supplied only to the coil 62c of the B-phase stator 62 according to pulses P[3] and P[7], the electric valve control device 70 acquires the voltage VA generated between terminals A1 and A2 of the coil 61c of the A-phase stator 61. The electric valve control device 70 does not acquire voltage VA and voltage VB when pulses P[2], P[4], P[6] and P[8] are input.

[0197] The electric valve control device 70 determines the state of the electric valve 5 at the end of the current period T during which pulses P[1] to P[8] are input (S140). Specifically, the electric valve control device 70 performs the following (1) to (8).

[0198] (1) The electric valve control device 70 calculates the area SA(k) of the waveform corresponding to the pulse P[7] in the current period T(k) for the waveform of the voltage VA. Then, when it is detected that the area SA(k) is smaller than the area SA(k-1) of the waveform corresponding to the pulse P[7] in the previous period T(k-1) and the difference between the area SA(k) and the area SA(k-1) is greater than or equal to a predetermined first area determination value, the electric valve control device 70 determines that the electric valve 5 is in the rotation restriction state Sr. In addition, the area SA(k) may be the area of ​​the waveform in a part of the period T(k) or the area of ​​the waveform in the entire period T(k).

[0199] (2) The electric valve control device 70 obtains the amplitude WA(k) of the D wave in the current period T(k) of the voltage VA waveform. Then, when it is detected that the amplitude WA(k) is smaller than the amplitude WA(k-1) of the D wave in the previous period T(k-1) and the difference between the amplitude WA(k) and the amplitude WA(k-1) is above a predetermined first amplitude judgment value, the electric valve control device 70 determines that the electric valve 5 is in the rotation restriction state Sr.

[0200] (3) When a new E wave, which is different from the A wave, B wave, C wave and D wave observed in all periods T, is detected to appear periodically in multiple consecutive periods T (e.g., three periods), the electric valve control device 70 determines that the electric valve 5 is in the rotation restriction state Sr.

[0201] (4) The electric valve control device 70 calculates the area SB(k) of the waveform corresponding to the pulse P[1] in the current period T(k) for the waveform of the voltage VB. Then, when it is detected that the area SB(k) is smaller than the area SB(k-1) of the waveform corresponding to the pulse P[1] in the previous period T(k-1) and the difference between the area SB(k) and the area SB(k-1) is greater than or equal to a predetermined second area determination value, the electric valve control device 70 determines that the electric valve 5 is in the rotation restriction state Sr. In addition, the area SB(k) may be the area of ​​the waveform in a part of the period T(k) or the area of ​​the waveform in the entire period T(k).

[0202] (5) The electric valve control device 70 obtains the amplitude WB1(k) of the G wave in the current period T(k) of the voltage VB waveform. Then, when it is detected that the amplitude WB1(k) is smaller than the amplitude WB1(k-1) of the G wave in the previous period T(k-1) and the difference between the amplitude WB1(k) and the amplitude WB1(k-1) is greater than or equal to a predetermined second amplitude determination value, the electric valve control device 70 determines that the electric valve 5 is in the rotation restriction state Sr.

[0203] (6) The electric valve control device 70 obtains the amplitude WB2(k) of the K wave in the current period T(k) of the voltage VB waveform. Then, when it is detected that the amplitude WB2(k) is smaller than the amplitude WB2(k-1) of the K wave in the previous period T(k-1) and the difference between the amplitude WB2(k) and the amplitude WB2(k-1) is greater than or equal to a predetermined third amplitude judgment value, the electric valve control device 70 determines that the electric valve 5 is in the rotation restriction state Sr.

[0204] (7) When a new M wave, which is different from the F wave, G wave, H wave, J wave, and K wave observed in all periods T, is detected to appear periodically in multiple consecutive periods T (e.g., three periods), the electric valve control device 70 determines that the electric valve 5 is in the rotation restriction state Sr.

[0205] Furthermore, the area and amplitude used in (1), (2), (4) to (6) above can also be moving averages over multiple consecutive periods T. Additionally, the electric valve control device 70 can also perform only a portion of (1) to (7) above.

[0206] (8) If the electric valve control device 70 does not determine that the electric valve 5 is in the rotation restriction state Sr in (1) to (7) above, it determines that the electric valve 5 is in the rotation permission state Sp.

[0207] Furthermore, the electric valve control device 70 can also make temporary determinations regarding (1) to (7) above. In this case, if the electric valve control device 70 makes a temporary determination that the electric valve 5 is in the rotation restriction state Sr multiple times (e.g., more than twice), it will formally determine that the electric valve 5 is in the rotation restriction state Sr. If the electric valve control device 70 does not formally determine that the electric valve 5 is in the rotation permission state Sp.

[0208] When the electric valve 5 is in the rotation restriction state Sr (S150: Yes), the electric valve control device 70 stops inputting pulses P[1] to P[8] to the stepper motor 66 and notifies the air conditioning control device 110 of the end of the initialization action (S170).

[0209] When the electric valve 5 is in the rotation-allowed state Sp (S150: No) and the number of pulses P input to the stepper motor 66 exceeds the initialization quantity X (S160: Yes), the electric valve control device 70 stops inputting pulses P to the stepper motor 66 and notifies the air conditioning control device 110 of the end of the initialization operation (S170). The initialization quantity X is the number of pulses P required to rotate the rotor 41 from the position (fully open position Rz) corresponding to the maximum opening of the valve port 17 to the reference position Rx. For example, the initialization quantity X is 500.

[0210] When the number of pulses P input to the stepper motor 66 is less than the initial number X (S160: No), the electric valve control device 70 acquires the voltage VA and voltage VB again (S130) and repeats the above operation (S130~S160).

[0211] The electric valve device 1 includes an electric valve 5 and an electric valve control device 70. The electric valve 5 includes: a valve body 10 having a valve seat 18; a rotor 41 rotatable relative to the valve body 10; a stator 60, which, together with the rotor 41, forms a stepper motor 66; a valve core 30 opposite to the valve seat 18 and pressed against the valve seat 18 via a closing spring 47 when the rotor 41 rotates in a first direction; and a stop mechanism 49 that restricts the rotation of the rotor 41 in the first direction when the rotor 41 is at a reference position Rx. The electric valve control device 70 supplies a drive current to the stator 60 to rotate the rotor 41 in the first direction. The electric valve control device 70 acquires the voltages VA and VB generated in the stator 60 due to the rotation of the rotor 41. Then, the electric valve control device 70 determines whether the electric valve 5 is in a rotation restriction state Sr, which restricts the rotation of the rotor 41 in the first direction by the stop mechanism 49, based on at least one of the following conditions: (i) the area of ​​the waveforms of voltage VA and voltage VB, (ii) the amplitude of the wave periodically observed in the waveforms of voltage VA and voltage VB, and (iii) the periodic appearance of a new wave that is different from the wave periodically observed in the waveforms of voltage VA and voltage VB.

[0212] Therefore, when the electric valve control device 70 determines that the electric valve 5 is in the rotation restriction state Sr, the rotor 41 is at the reference position Rx. Thus, when the electric valve control device 70 determines that the electric valve 5 is in the rotation restriction state Sr, by stopping the rotation of the rotor 41 in the first direction, the time required for initialization can be shortened. Furthermore, after the rotor 41 is positioned at the reference position Rx, the number of times the movable stop 42s and the fixed stop 44s repeatedly collide can be reduced. Therefore, the electric valve control device 70 can suppress noise generation over a long period and can suppress wear and fatigue of the movable stop 42s and the fixed stop 44s. The electric valve control device 70 can suppress noise and extend the lifespan of the electric valve 5.

[0213] Furthermore, the electric valve control device 70 determines whether the electric valve 5 is in the rotation-limited state Sr based on the waveform area SA of voltage VA and the waveform area SB of voltage VB. The electric valve control device 70 also determines whether the electric valve is in the rotation-limited state Sr based on the amplitude WA of the D wave periodically observed in the waveform of voltage VA and the amplitudes WB1 and WB2 of the G wave and K wave periodically observed in voltage VB. The electric valve control device 70 further determines whether the electric valve 5 is in the rotation-limited state Sr based on the periodic appearance of a new E wave, different from the A, B, C, and D waves periodically observed in the waveform of voltage VA, and the periodic appearance of a new M wave, different from the F, G, H, J, and K waves periodically observed in voltage VB. Therefore, it is possible to determine whether the electric valve 5 is in the rotation-limited state Sr by performing relatively simple processing on voltages VA and VB.

[0214] Furthermore, when the electric valve control device 70 determines that the electric valve 5 is in the rotation restriction state Sr, it stops the input of pulse P to the stepper motor 66 and stops the supply of drive current to the stator 60. Thus, for example, by notifying the air conditioning control device 110 that the electric valve 5 is in the rotation restriction state Sr and receiving a stop command from the air conditioning control device 110, the rotation of the rotor 41 in the first direction can be stopped simply and quickly compared to the structure that stops the initialization operation.

[0215] Furthermore, the stator 60 has an A-phase stator 61 and a B-phase stator 62. The electric valve control device 70 acquires the voltage VB generated in the B-phase stator 62 when only the drive current is supplied to the A-phase stator 61, and acquires the voltage VA generated in the A-phase stator 61 when only the drive current is supplied to the B-phase stator 62. Therefore, in the electric valve control device 70, it is not necessary to separate the electromagnetically induced voltage component from the voltage generated in the A-phase stator 61, nor is it necessary to separate the electromagnetically induced voltage component from the voltage generated in the B-phase stator 62. Thus, voltages VA and VB can be acquired with a relatively simple structure.

[0216] The electric valve control device 70 determines whether the electric valve 5 is in a rotation-allowed state Sp or a rotation-limited state Sr. The electric valve control device 70 can also determine the state of the electric valve 5 other than the rotation-allowed state Sp or the rotation-limited state Sr.

[0217] according to Figure 16In the waveform of voltage VA, the D wave is a positive voltage wave with a constant amplitude during each period T before time tc (d1, d2), and its amplitude gradually decreases between time tc and time tx (d3 to d5). Similarly, in the waveform of voltage VB, the K wave is a negative voltage wave with a constant amplitude during each period before time tc (k1, k2), and its amplitude gradually decreases between time tc and time tx (k3 to k5). It is presumed that this is due to the gradual compression of the valve-closing spring 47 after the rotor 41 passes the closed valve position Rc, causing a gradual decrease in the rotational speed of the rotor 41. Therefore, by detecting the gradual decrease in the amplitude of the waves in the waveforms of voltage VA or voltage VB, it can be determined that the rotor 41 is between the closed valve position Rc and the reference position Rx.

[0218] Therefore, it is also possible that when the amplitude of the D wave, which is periodically observed in the waveform of voltage VA, gradually decreases and / or the amplitude of the K wave, which is periodically observed in the waveform of voltage VB, gradually decreases, the electric valve control device 70 determines that the electric valve 5 is in an intermediate state Sq between the closed position Rc and the reference position Rx. The intermediate state Sq is a state between the rotation-allowed state Sp and the rotation-limited state Sr. For example, by including the case where the electric valve 5 has been determined to be in the intermediate state Sq in the determination condition of the rotation-limited state Sr, the accuracy of the determination of the rotation-limited state Sr can be further improved.

[0219] Alternatively, the electric valve 5 is configured such that when the rotor 41 rotates in the first direction, the valve shaft retainer 42, which is fitted with the rotor 41, presses the valve core 30 downward via the valve closing spring 47. The electric valve 5 can also be configured such that when the rotor 41 rotates in the first direction, the valve shaft retainer 42, which is fitted with the rotor 41, directly presses the valve core 30 downward. Alternatively, the electric valve 5 can also be configured such that the rotor 41 (or valve shaft retainer 42) is fixed to the valve core 30. In this configuration, when the valve core 30 contacts the valve seat 18, the rotation of the rotor 41 in the first direction is restricted. That is, the valve core 30 and the valve seat 18 constitute a stop mechanism, and the position of the rotor 41 when the valve core 30 contacts the valve seat 18 is the reference position Rx that restricts the rotation of the rotor 41 in the first direction.

[0220] Furthermore, the electric valve control device 70 determines whether the electric valve 5 is in a rotation-limiting state Sr based on the voltage generated in the stator 60 due to the rotation of the rotor 41. Since current is closely related to voltage, the electric valve control device 70 can also determine whether the electric valve 5 is in a rotation-limiting state Sr based on the current generated in the stator 60 due to the rotation of the rotor 41. In this structure, the electric valve control device 70 has a current acquisition unit instead of a voltage acquisition unit, which acquires the current generated in the stator 60 due to the rotation of the rotor 41 (the current electromagnetically induced by the stator 60). Then, the state determination unit determines whether the electric valve 5 is in a rotation-limiting state Sr based on at least one of the following conditions: (i) the area of ​​the current waveform, (ii) the amplitude of the wave periodically observed in the current waveform, and (iii) the periodic appearance of a new wave different from the wave periodically observed in the current waveform.

[0221] The electric valve 5 has a drive mechanism 40 that operates without slowing down the rotation of the rotor 41. Alternatively, the electric valve 5 may have a drive mechanism with a speed reduction mechanism that slows down the rotation of the rotor 41, instead of the drive mechanism 40.

[0222] Next, an electric valve device 2 according to an embodiment of the present invention will be described. The electric valve device 2 has the same hardware structure as the electric valve device 1. The operation of the electric valve control device 70 of the electric valve device 2 is different from the operation of the electric valve control device 70 of the electric valve device 1.

[0223] The electric valve control device 70 acquires voltage VA and voltage VB sequentially. That is, the electric valve control device 70 acquires the waveforms of voltage VA and voltage VB. Then, the electric valve control device 70 compares the waveforms of voltage VA and voltage VB with preset reference waveforms of voltage VA and voltage VB to determine the state of the electric valve 5.

[0224] The electric valve 5 has a first rotation-allowing state Sp1, a second rotation-allowing state Sp2, a first rotation-limiting state Sr1, and a second rotation-limiting state Sr2. The first rotation-allowing state Sp1 allows the rotor 41 to rotate in a first direction. The second rotation-allowing state Sp2 allows the rotor 41 to rotate in a second direction. The first rotation-limiting state Sr1 restricts the rotation of the rotor 41 in the first direction. The second rotation-limiting state Sr2 restricts the rotation of the rotor 41 in the second direction.

[0225] The non-volatile memory 75 of the electric valve control device 70 stores the reference waveforms of voltage VA and voltage VB. The reference waveforms include a first rotation-allowed state waveform, a second rotation-allowed state waveform, and a first rotation-limited state waveform.

[0226] A reference waveform is set for pulse P. In this embodiment, a reference waveform is set for a portion of pulse P (P[1], P[3], P[5], P[7]), while no reference waveform is set for the remaining pulses P (P[2], P[4], P[6], P[8]). The reference waveform is set based on the waveforms of voltage VA and voltage VB obtained in the normally functioning electric valve 5.

[0227] The waveform of the first rotational allowable state of voltage VA is set based on the waveform of voltage VA obtained when electric valve 5 is in the first rotational allowable state Sp1 and drive current is supplied only to coil 62c of B phase stator 62 according to pulses P[3] and P[7] that cause rotor 41 to rotate in the first direction.

[0228] The waveform of the first rotational allowable state of voltage VB is set based on the waveform of voltage VB obtained when electric valve 5 is in the first rotational allowable state Sp1 and drive current is supplied only to coil 61c of A phase stator 61 according to pulses P[1] and P[5] that cause rotor 41 to rotate in the first direction.

[0229] The second rotational allowable state waveform of voltage VA is set based on the waveform of voltage VA obtained when electric valve 5 is in the second rotational allowable state Sp2 and drive current is supplied only to coil 62c of B phase stator 62 according to pulses P[3] and P[7] that cause rotor 41 to rotate in the second direction.

[0230] The second rotational allowable state waveform of voltage VB is set based on the waveform of voltage VB obtained when electric valve 5 is in the second rotational allowable state Sp2 and drive current is supplied only to coil 61c of A phase stator 61 according to pulses P[1] and P[5] that cause rotor 41 to rotate in the second direction.

[0231] In this embodiment, the first rotation-allowed state waveform and the second rotation-allowed state waveform are set based on the waveforms of multiple voltages (the waveforms of voltage VA and voltage VB) individually acquired in each electric valve 5 at the time of manufacture. The electric valve control device 70 stores the first rotation-allowed state waveform and the second rotation-allowed state waveform set based on the waveforms of the multiple voltages acquired in the electric valve 5 associated with it.

[0232] Alternatively, the first and second rotation-allowed state waveforms can be set based on the waveforms of multiple voltages acquired in the multiple electric valves 5. In this case, the multiple electric valve control devices 70 store a common first and second rotation-allowed state waveform.

[0233] When acquiring the voltage waveforms used to set the first and second rotational allowable states, to avoid the valve-closing spring 47 affecting the rotation of the rotor 41, it is preferable that the rotor 41 is between the closed position Rc and the fully open position Rz. The first rotational allowable state waveform is the center line of the multiple voltage waveforms. The second rotational allowable state waveform is the center line of the multiple voltage waveforms. The center line is, for example, a line formed by connecting the average voltages of each acquisition time (sampling time) in the multiple voltage waveforms in the order of that acquisition time.

[0234] The first rotational allowable state waveform of voltage VA is set one by one for pulses P[3] and P[7] respectively, and the first rotational allowable state waveform of voltage VB is set one by one for pulses P[1] and P[5] respectively. The second rotational allowable state waveform of voltage VA is set one by one for pulses P[3] and P[7] respectively, and the second rotational allowable state waveform of voltage VB is set one by one for pulses P[1] and P[5] respectively.

[0235] Figure 20 This section shows an example of a waveform that includes the first rotational allowable state waveform of the voltage VB set for pulse P[1] and the first rotational allowable state waveform of the voltage VB set for pulse P[5].

[0236] The first and second rotational allowable state waveforms are stored as a data table in non-volatile memory 75.

[0237] The non-volatile memory 75 stores first rotation permission state tables C[3], C[7], C[1] and C[5]. First rotation permission state table C[3] is the first rotation permission state waveform of voltage VA set for pulse P[3] input when the rotor 41 rotates in the first direction. First rotation permission state table C[7] is the first rotation permission state waveform of voltage VA set for pulse P[7] input when the rotor 41 rotates in the first direction. First rotation permission state table C[1] is the first rotation permission state waveform of voltage VB set for pulse P[1] input when the rotor 41 rotates in the first direction. First rotation permission state table C[5] is the first rotation permission state waveform of voltage VB set for pulse P[5] input when the rotor 41 rotates in the first direction. The pulses P[3], P[7], P[1] and P[5] input when the rotor 41 rotates in the first direction are first direction pulses.

[0238] The non-volatile memory 75 stores the second rotation permission state tables D[3], D[7], D[1] and D[5]. The second rotation permission state table D[3] is the second rotation permission state waveform of the voltage VA set for the pulse P[3] input when the rotor 41 rotates in the second direction. The second rotation permission state table D[7] is the second rotation permission state waveform of the voltage VA set for the pulse P[7] input when the rotor 41 rotates in the second direction. The second rotation permission state table D[1] is the second rotation permission state waveform of the voltage VB set for the pulse P[1] input when the rotor 41 rotates in the second direction. The second rotation permission state table D[5] is the second rotation permission state waveform of the voltage VB set for the pulse P[5] input when the rotor 41 rotates in the second direction. The pulses P[3], P[7], P[1] and P[5] input when the rotor 41 rotates in the second direction are second direction pulses.

[0239] The waveform of the first rotational limitation state of voltage VA is set based on the waveform of voltage VA obtained when electric valve 5 is in the first rotational limitation state Sr1 and driving current is supplied only to coil 62c of B phase stator 62 according to pulses P[3] and P[7] that cause rotor 41 to rotate in the first direction.

[0240] The waveform of the first rotational limitation state of voltage VB is set based on the waveform of voltage VB obtained when electric valve 5 is in the first rotational limitation state Sr1 and driving current is supplied only to coil 61c of A phase stator 61 according to pulses P[1] and P[5] that cause rotor 41 to rotate in the first direction.

[0241] Among the multiple electric valves 5, depending on the different precision of the parts and the assembly precision, the pulse P (pattern number) corresponding to the time point when the rotation of the rotor 41 in the first direction is restricted by the stop mechanism 49 is different. The time point when the rotation of the rotor 41 in the first direction is restricted by the stop mechanism 49 is the time point when the movable stop 42s and the fixed stop 44s abut. Among the multiple electric valves 5, for example, if there is an electric valve 5 where the movable stop 42s and the fixed stop 44s abut at the time point when pulse P[1] is input (the former electric valve 5), then there is also an electric valve 5 where the movable stop 42s and the fixed stop 44s abut at the time point when pulse P[2] (or any one of P[3] to P[8]) is input (the latter electric valve 5). In the former electric valve 5 and the latter electric valve 5, the position of the rotor 41 (specifically, the relative position of the rotor 41 and the stator 60) at the time point when each pulse P is input is different. That is, in the former electric valve 5 and the latter electric valve 5, for example, the position of the rotor 41 at the time point when pulse P[1] (or any one of P[2] to P[8]) is input is different. In the electric valve 5, if the position of the rotor 41 is different, the waveform of the voltage generated by the rotation of the rotor 41 is also different. Therefore, in the former electric valve 5 and the latter electric valve 5, the waveform of the voltage (the waveform of voltage VA and the waveform of voltage VB) when pulse P with the same pattern number is input is different. Thus, in multiple electric valves 5 where the pulse P corresponding to the time point of contact with the movable stop 42s and the fixed stop 44s is different from each other, the waveform of the voltage when a pulse P with the same pattern number is input is different from each other, and there are multiple changing waveforms of the first rotation limit state waveform for a pulse P. The number of changing waveforms of the first rotation limit state waveform of voltage VA for a pulse P is the same as the number of patterns of pulse P. The number of waveforms changing with respect to the first rotational limit state of voltage VB for a single pulse P is the same as the number of patterns for pulse P.

[0242] In one electric valve 5, the pulse P (pattern number) corresponding to the time point when the movable stop 42s and the fixed stop 44s come into contact is always the same. For example, in one electric valve 5, the pulse P input at the time point when the movable stop 42s comes into contact with the fixed stop 44s is pulse P[1]. In other electric valves 5, the pulse P input at the time point when the movable stop 42s comes into contact with the fixed stop 44s is pulse P[2] (or any one of [3] to [8]).

[0243] In this embodiment, the first rotation restriction state waveform is set based on the waveforms of multiple voltages (the waveforms of voltage VA and voltage VB) individually acquired in each electric valve 5 at the time of manufacture. The electric valve control device 70 stores a first rotation allowance state waveform set based on the waveforms of multiple voltages acquired in the electric valve 5 associated with it.

[0244] In this embodiment, the first rotational limiting state waveform of voltage VA is set for pulses P[3] and P[7] respectively, and the first rotational limiting state waveform of voltage VB is set for pulses P[1] and P[5] respectively.

[0245] Alternatively, the first rotation limit state waveform can also be set based on the waveforms of multiple voltages acquired in the multiple electric valves 5. In this case, a common first rotation allowance state waveform is stored in the multiple electric valve control devices 70. Then, multiple first rotation limit state waveforms are set for pulses P[3], P[7], P[1], and P[5]. The multiple first rotation limit state waveforms are composed of variations of the first rotation limit state waveform. For pulses P[3] and P[7], first rotation limit state waveforms of eight voltages VA are set respectively, and for pulses P[1] and P[5], first rotation limit state waveforms of eight voltages VB are set respectively.

[0246] Alternatively, the waveform most suitable for the electric valve 5 in conjunction with the electric valve control device 70 can be set as the first rotation limit state waveform in the electric valve control device 70 from among the multiple first rotation limit state waveforms (variable waveforms). In this case, the first rotation limit state waveform of voltage VA is set one by one for pulses P[3] and P[7], and the first rotation limit state waveform of voltage VB is set one by one for pulses P[1] and P[5].

[0247] When acquiring the waveform of the voltage used to set the first rotation limiting state waveform, it is preferable that the electric valve 5 is in a state where the rotation of the rotor 41 in the first direction is limited by the stop mechanism 49. The first rotation limiting state waveform is the center line of the waveforms of multiple voltages.

[0248] The waveform of the first rotational limitation state is stored as a data table in the non-volatile memory 75.

[0249] The non-volatile memory 75 stores first rotation limit state tables E[3], E[7], E[1] and E[5]. First rotation limit state table E[3] is the first rotation limit state waveform of voltage VA set for pulse P[3] input when the rotor 41 rotates in the first direction. First rotation limit state table E[7] is the first rotation limit state waveform of voltage VA set for pulse P[7] input when the rotor 41 rotates in the first direction. First rotation limit state table E[1] is the first rotation limit state waveform of voltage VB set for pulse P[1] input when the rotor 41 rotates in the first direction. First rotation limit state table E[5] is the first rotation limit state waveform of voltage VB set for pulse P[5] input when the rotor 41 rotates in the first direction.

[0250] Alternatively, when multiple first rotation limit state waveforms are set for pulses P[3], P[7], P[1], and P[5], the non-volatile memory 75 stores first rotation limit state tables E[3]_1~E[3]_8, E[7]_1~E[7]_8, E[1]_1~E[1]_8, and E[5]_1~E[5]_8. First rotation limit state tables E[3]_1~E[3]_8 are first rotation limit state waveforms of eight voltages VA set for the pulse P[3] input when the rotor 41 is rotated in the first direction. First rotation limit state tables E[7]_1~E[7]_8 are first rotation limit state waveforms of eight voltages VA set for the pulse P[7] input when the rotor 41 is rotated in the first direction. The first rotation limit state tables E[1]_1 to E[1]_8 are the first rotation limit state waveforms of eight voltages VB set for the pulse P[1] input when the rotor 41 is rotated in the first direction. The first rotation limit state tables E[5]_1 to E[5]_8 are the first rotation limit state waveforms of eight voltages VB set for the pulse P[5] input when the rotor 41 is rotated in the first direction.

[0251] Figures 21-28 This section shows an example of a waveform that includes the first rotation limit state waveform of the voltage VB set for pulse P[1] and the first rotation limit state waveform of the voltage VB set for pulse P[5]. Figures 21-28 The waveform shown is obtained from an electric valve 5 whose pulse P corresponds to the contact points of the movable stop 42s and the fixed stop 44s, and is an example of the waveform of the first rotational limit state of the voltage VB.

[0252] In this embodiment, the data table stored in the non-volatile memory 75 is shown below. The numbers in square brackets correspond to the pattern numbers of pulse P.

[0253] First rotational allowable state waveform of voltage VA

[0254] First rotational allowable state table C[3]

[0255] First rotational allowable state table C[7]

[0256] First rotational allowable state waveform of voltage VB

[0257] First rotational allowable state table C[1]

[0258] First rotational permissible state table C[5]

[0259] The second rotational allowable state waveform of voltage VA

[0260] Second rotational permissible state table D[3]

[0261] Second rotational allowable state table D[7]

[0262] The second rotational allowable state waveform of voltage VB

[0263] Second rotational allowable state table D[1]

[0264] Second rotational permissible state table D[5]

[0265] First rotational limiting state waveform of voltage VA

[0266] First rotational constraint state table E[3]

[0267] First rotational constraint state table E[7]

[0268] The waveform of the first rotational limiting state of voltage VB

[0269] First rotational constraint state table E[1]

[0270] First rotational constraint state table E[5]

[0271] In each data table, a specified actual time t elapsed from the start of pulse P (time 0) is associated with a reference voltage rv at that time t. For example, the period from the start to the end of pulse P is 8 ms, and the interval of time t is 200 μs. A data table has forty groups of time t and reference voltage rv. Figure 29 This represents an example of the first rotation-allowed state table C[1]. In Figure 29 In this context, the unit of time t is μs. The unit of the reference voltage rv is mV. The units of time t and the reference voltage rv can, for example, be inherent units corresponding to the sampling period and decomposition energy of the A / D converter possessed by the electric valve control device 70.

[0272] The computer 80 of the electric valve control device 70 functions as a rotation control unit 81, a voltage acquisition unit 82, and a status determination unit 83.

[0273] The rotation control unit 81 and the voltage acquisition unit 82 have the same (including substantially the same) structure as the electric valve 1 described above. The voltage acquisition unit 82 acquires voltages VA and VB sequentially at time intervals equal to the time intervals t in the data table during the period from the start to the end of pulse P. In this embodiment, the voltage acquisition unit 82 acquires voltages VA and VB forty times corresponding to the input of one pulse P.

[0274] During initialization, the state determination unit 83 calculates a value (difference index value) indicating the degree of difference between the waveforms of the voltages acquired by the voltage acquisition unit 82 (the waveforms of voltage VA and voltage VB) and the reference waveforms of the voltages (the reference waveforms of voltage VA and voltage VB). The state determination unit 83 determines the state of the electric valve 5 based on the difference index value. The larger the difference index value, the greater the degree of difference between the voltage waveforms and the reference waveforms.

[0275] When the voltage acquisition unit 82 acquires voltage v (voltage VA, voltage VB) corresponding to the input of pulse P[k] (k = 1, 3, 5, 7) at acquisition time tv, the state determination unit 83 reads the reference voltage rv associated with time t corresponding to acquisition time tv from the data table of the reference waveform corresponding to pulse P[k] (at least one of the first rotation allowable state table C[k], the second rotation allowable state table D[k], and the first rotation restriction state E[k]). The state determination unit 83 calculates the value (dv) obtained by subtracting the reference voltage rv from the voltage acquired by the voltage acquisition unit 82. The state determination unit 83 calculates the value obtained by squaring the difference dv (intermediate value dv2). The state determination unit 83 adds the multiple intermediate values ​​dv2 calculated corresponding to the input of pulse P[k] to calculate the difference index value sv[k]. The state determination unit 83 compares the difference index value sv[k] with the predetermined difference determination value H. The state determination unit 83 determines whether the electric valve 5 is in any one of the first rotation-allowed state Sp1, the second rotation-allowed state Sp2, the first rotation-restricted state Sr1, and the second rotation-restricted state Sr2 based on the comparison result between the difference index value sv[k] and the prescribed difference determination value H. Furthermore, when pulses P[2], P[4], P[6], and P[8] that cause the rotor 41 to rotate in the first direction are input, the state determination unit 83 determines that the electric valve 5 is in the first rotation-allowed state Sp1. When pulses P[2], P[4], P[6], and P[8] that cause the rotor 41 to rotate in the second direction are input, the state determination unit 83 determines that the electric valve 5 is in the second rotation-allowed state Sp2.

[0276] In this embodiment, the state determination unit 83 uses the voltage v acquired by the voltage acquisition unit 82 during a portion of the period from the start to the end of pulse P[k] to calculate the difference index value sv[k]. Specifically, when the period from the start of pulse P[k] to time t1 is taken as the first period p1, and the period from time t1 to time t2 is taken as the second period p2, the state determination unit 83 uses the voltage v of the second period p2 to calculate the difference index value sv[k]. Figure 30Examples show the waveform (solid line) of voltage VB acquired corresponding to the input of pulse P[1] and the waveform (dashed line) of the first rotational allowable state of voltage VB. Time t1 is the time after the start of pulse P[k]. Time t2 is the time after time t1 and before the end of pulse P[k]. Time t2 can also be the end of pulse P[k]. Figure 30 In the second period p2, the length of the vertical line connecting the waveform of voltage VB and the waveform of the first rotation allowed state of voltage VB corresponds to the difference dv used to calculate the difference index value svC[1]. The state determination unit 83 does not use the voltage v of the first period p1 to calculate the difference index value sv[k].

[0277] The voltage v includes: a voltage component related to the back electromotive force caused by the inductance of the stator 60 coil shortly after the start of pulse P[k] (the former voltage component); and a voltage component related to the electromagnetic induction caused by the rotation of rotor 41 (the latter voltage component), with the former voltage component being larger than the latter voltage component. The former voltage component decreases over time. Therefore, the state determination unit 83 uses the voltage v acquired by the voltage acquisition unit 82 after a certain period of time has elapsed since the start of pulse P[k] to calculate the difference index value sv[k]. Specifically, the state determination unit 83 uses the voltage v acquired by the voltage acquisition unit 82 to calculate the difference index value sv[k] after the former voltage component becomes smaller than the latter voltage component. As a result, the proportion of the latter voltage component in the voltage v increases relatively, and the state determination unit 83 can further determine the state of the electric valve 5 with higher accuracy. The length of the first period p1 is 5% to 50% of the period from the start to the end of pulse P[k], 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 pulse P[k], preferably 70% to 80%. In the voltage v acquired by the voltage acquisition unit 82 during the second period p2, the voltage component related to the back electromotive force caused by the inductance of the stator 60 coil is smaller than the voltage component related to the electromagnetic induction caused by the rotation of the rotor 41. Furthermore, the state determination unit 83 can also use the voltage v acquired by the voltage acquisition unit 82 during the entire period from the start to the end of pulse P[k] to calculate the difference index value sv[k]. In this case, pulse P[k] starts at time t1 and ends at time t2.

[0278] When the voltage v acquired at time tv between time t1 and time t2 is set as v[tv], and the reference voltage rv associated with time t corresponding to the acquisition time tv in the reference waveform data table is set as rv[tv], the difference index value sv is represented by the following formula (1).

[0279] [Formula 1]

[0280]

[0281] Next, refer to Figure 31 An example of the initialization action of the electric valve control device 70 (Action Example 1) will be explained.

[0282] In Action Example 1, the electric valve control device 70 terminates the initialization action of the electric valve 5 when the rotation of the rotor 41 in the first direction is restricted.

[0283] When the electric valve control device 70 receives an initialization command from the air conditioning control device 110 (S210), it begins to input the ascending pulses P[1] to P[8] of the stepper motor 66 (S220). As a result, the initialization operation begins, the stator 60 is supplied with the drive current corresponding to the pulses P[1] to P[8], and the rotor 41 rotates in the first direction.

[0284] When the rotor 41 rotates in the first direction, the electric valve control device 70 sequentially acquires the voltage VA generated between terminals A1 and A2 of the coil 61c of the A-phase stator 61 and the voltage VB generated between terminals B1 and B2 of the coil 62c of the B-phase stator 62 (S230). That is, the electric valve control device 70 acquires the waveforms of voltage VA and voltage VB. Specifically, when driving current is supplied only to the coil 61c of the A-phase stator 61 according to pulses P[1] and P[5], the electric valve control device 70 acquires the voltage VB generated between terminals B1 and B2 of the coil 62c of the B-phase stator 62. In addition, when driving current is supplied only to the coil 62c of the B-phase stator 62 according to pulses P[3] and P[7], the electric valve control device 70 acquires the voltage VA generated between terminals A1 and A2 of the coil 61c of the A-phase stator 61. The electric valve control device 70 does not acquire voltage VA and voltage VB when pulses P[2], P[4], P[6] and P[8] are input.

[0285] The electric valve control device 70 calculates the difference index value sv (S235) and determines the state of the electric valve 5 based on the difference index value sv (S240). There are three methods for determining the first rotation restriction state Sr1 based on the difference index value sv.

[0286] Judgment Method 1: Use only the first rotation allowed state table C.

[0287] Judgment Method 2: Use only the first rotation limit state table E.

[0288] Judgment Method 3: Use the first rotation allowable state table C and the first rotation limit state table E.

[0289] <Judgment Method 1>

[0290] The electric valve control device 70 uses the first rotation allowable state table C[k] (k = 1, 3, 5, 7) to calculate the difference index value svC[k] (S235). Specifically, the electric valve control device 70 uses the first rotation allowable state table C[1] to calculate the difference index value svC[1] corresponding to the input of pulse P[1]. The electric valve control device 70 uses the first rotation allowable state table C[3] to calculate the difference index value svC[3] corresponding to the input of pulse P[3]. The electric valve control device 70 uses the first rotation allowable state table C[5] to calculate the difference index value svC[5] corresponding to the input of pulse P[5]. The electric valve control device 70 uses the first rotation allowable state table C[7] to calculate the difference index value svC[7] corresponding to the input of pulse P[7].

[0291] The electric valve control device 70 determines the state of the electric valve 5 at the end of pulse P[k] (S240). Specifically, the electric valve control device 70 compares the difference index value svC[k] with the difference judgment value HC, and compares the difference index value svC[j] calculated just before the difference index value svC[k] (j=k-2 when k=3, 5, 7, j=7 when k=1) with the difference judgment value HC. When both the difference index value svC[k] and the difference index value svC[j] are above the difference judgment value HC, the electric valve control device 70 determines that the electric valve 5 is in the first rotation restriction state Sr1. At this time, the electric valve control device 70 stores the previous number of j (j-1 when j=3, 5, 7, 8 when j=1) as the start pattern number Nx in the non-volatile memory 75. When the electric valve control device 70 does not determine that the electric valve 5 is in the first rotation-allowing state Sp1, the electric valve control device 70 determines that the electric valve 5 is in the first rotation-limiting state Sr1.

[0292] As a variation of determination method 1, the electric valve control device 70 may determine the state of the electric valve 5 using only the difference index value svC[k] instead of the difference index value svC[j]. In this case, the electric valve control device 70 determines that the electric valve 5 is in the first rotation restriction state Sr1 when the difference index value svC[k] is greater than or equal to the difference determination value HC. At this time, the electric valve control device 70 stores the previous number of k (k-1 when k = 3, 5, or 7, and 8 when k = 1) as the start pattern number Nx in the non-volatile memory 75. The electric valve control device 70 determines that the electric valve 5 is in the first rotation allowable state Sp1 when the difference index value svC[k] is less than the difference determination value HC.

[0293] As another variation of determination method 1, the electric valve control device 70 may determine the state of the electric valve 5 using only one of the waveforms of voltage VA and voltage VB. The electric valve control device 70 may also determine the state of the electric valve 5 using only the waveform of voltage VA corresponding to one of pulses P[3] and P[7]. The electric valve control device 70 may also determine the state of the electric valve 5 using only the waveform of voltage VB corresponding to one of pulses P[1] and P[5]. Preferably, the waveform used for determination has less noise.

[0294] For example, the electric valve control device 70 uses the first rotational permissible state table C[k] (k = 1, 7) to calculate the difference index value svC[k] (S235). The electric valve control device 70 determines the state of the electric valve 5 at the end of the pulse P[k] (S240). Alternatively, k can be 3, 5, 1, 3, or 5, 7. Or, k can be one of 1, 3, 5, or 7.

[0295] Specifically, when k=7, the electric valve control device 70 compares the difference index value svC[7] and the difference judgment value HC, and compares the difference index value svC[7]' calculated just before the difference index value svC[7] with the difference judgment value HC. When the period during which pulses P[1] to P[8] are input is set as period T, the difference index value svC[7]' is calculated corresponding to the input of pulse P[7] in the period T immediately preceding the current period T. When the difference index value svC[7] is greater than or equal to the difference judgment value HC and the difference index value svC[7]' is greater than or equal to the difference judgment value HC, the electric valve control device 70 determines that the electric valve 5 is in the first rotation restriction state Sr1. At this time, the electric valve control device 70 stores the number preceding k (i.e., 6) as the start pattern number Nx in the non-volatile memory 75. When k=1, the electric valve control device 70 compares the difference index value svC[1] and the difference judgment value HC, and also compares the difference index value svC[1]' calculated just before the difference index value svC[1] with the difference judgment value HC. The difference index value svC[1]' is calculated corresponding to the input of the pulse P[1] in the period T immediately preceding the current period T. When the difference index value svC[1] is greater than or equal to the difference judgment value HC and the difference index value svC[1]' is greater than or equal to the difference judgment value HC, the electric valve control device 70 determines that the electric valve 5 is in the first rotation restriction state Sr1. At this time, the electric valve control device 70 stores the number preceding k (i.e., 8) as the start pattern number Nx in the non-volatile memory 75. When the electric valve control device 70 does not determine that the electric valve 5 is in the first rotation restriction state Sr1, it determines that the electric valve 5 is in the first rotation allowable state Sp1.

[0296] <Judgment Method 2>

[0297] The electric valve control device 70 uses the first rotation limit state table E[k] to calculate the difference index value svE[k] (S235). Specifically, the electric valve control device 70 uses the first rotation limit state table E[1] to calculate the difference index value svE[1] corresponding to the input of pulse P[1]. The electric valve control device 70 uses the first rotation limit state table E[3] to calculate the difference index value svE[3] corresponding to the input of pulse P[3]. The electric valve control device 70 uses the first rotation limit state table E[5] to calculate the difference index value svE[5] corresponding to the input of pulse P[5]. The electric valve control device 70 uses the first rotation limit state table E[7] to calculate the difference index value svE[7] corresponding to the input of pulse P[7].

[0298] The electric valve control device 70 determines the state of the electric valve 5 at the end of pulse P[k] (S240). Specifically, the electric valve control device 70 compares the difference index value svE[k] with the difference judgment value HE, and also compares the difference index value svE[j] calculated just before the difference index value svE[k] with the difference judgment value HE. The electric valve control device 70 determines that the electric valve 5 is in the first rotation restriction state Sr1 when the difference index value svE[k] is smaller than the difference judgment value HE and the difference index value svE[j] is smaller than the difference judgment value HE. At this time, the electric valve control device 70 stores the number preceding j as the start pattern number Nx in the non-volatile memory 75. When the electric valve control device 70 does not determine that the electric valve 5 is in the first rotation restriction state Sr1, the electric valve control device 70 determines that the electric valve 5 is in the first rotation allowable state Sp1.

[0299] As a variation of determination method 2, the electric valve control device 70 may determine the state of the electric valve 5 using only the difference index value svE[k] instead of the difference index value svE[j]. In this case, the electric valve control device 70 determines that the electric valve 5 is in the first rotation restriction state Sr1 when the difference index value svE[k] is less than the difference determination value HE. At this time, the electric valve control device 70 stores the number preceding k as the start pattern number Nx in the non-volatile memory 75. The electric valve control device 70 determines that the electric valve 5 is in the first rotation allowable state Sp1 when the difference index value svE[k] is greater than or equal to the difference determination value HE.

[0300] As another variation of determination method 2, when multiple first rotation limit state waveforms (E[3]_1~E[3]_8, E[7]_1~E[7]_8, E[1]_1~E[1]_8 and E[5]_1~E[5]_8) are set for a pulse P, the electric valve control device 70 determines the state of the electric valve 5 as follows: The electric valve control device 70 uses the first rotation limit state table E[k]_1~E[k]_8 to calculate the difference index values ​​svE[k]_1~svE[k]_8. The electric valve control device 70 compares the difference index values ​​svE[k]_1~svE[k]_8 with the difference determination value HE, and compares the difference index values ​​svE[j]_1~svE[j]_8 with the difference determination value HE. If at least one of the difference index values ​​svE[k]_1 to svE[k]_8 is smaller than the difference judgment value HE, and at least one of the difference index values ​​svE[j]_1 to svE[j]_8 is smaller than the difference judgment value HE, the electric valve control device 70 determines that the electric valve 5 is in the first rotation restriction state Sr1. At this time, the electric valve control device 70 stores the previous number of j as the start pattern number Nx in the non-volatile memory 75. When the electric valve control device 70 does not determine that the electric valve 5 is in the first rotation restriction state Sr1, it determines that the electric valve 5 is in the first rotation allowable state Sp1. Alternatively, the electric valve control device 70 may determine the state of the electric valve 5 using only the difference index values ​​svE[k]_1 to svE[k]_8, without using the difference index values ​​svE[j]_1 to svE[j]_8.

[0301] As another variation of determination method 2, the electric valve control device 70 may determine the state of the electric valve 5 using only one of the waveforms of voltage VA and voltage VB. The electric valve control device 70 may also determine the state of the electric valve 5 using only the waveform of voltage VA corresponding to one of pulses P[3] and P[7]. The electric valve control device 70 may also determine the state of the electric valve 5 using only the waveform of voltage VB corresponding to one of pulses P[1] and P[5]. Preferably, the waveform used for determination has less noise.

[0302] For example, the electric valve control device 70 uses the first rotation limit state table E[k] (k = 1, 7) to calculate the difference index value svE[k] (S235). The electric valve control device 70 determines the state of the electric valve 5 at the end of the pulse P[k] (S240). Alternatively, k can be 3, 5, 1, 3, or 5, 7. Or, k can be one of 1, 3, 5, 7.

[0303] Specifically, when k=7, the electric valve control device 70 compares the difference index value svE[7] and the difference judgment value HE, and also compares the difference index value svE[7]' calculated just before the difference index value svE[7] with the difference judgment value HE. The difference index value svE[7]' is calculated corresponding to the input of the pulse P[7] in the period T immediately preceding the current period T. When the difference index value svE[7] is smaller than the difference judgment value HE and the difference index value svE[7]' is smaller than the difference judgment value HE, the electric valve control device 70 determines that the electric valve 5 is in the first rotation restriction state Sr1. At this time, the electric valve control device 70 stores the number preceding k (i.e., 6) as the start pattern number Nx in the non-volatile memory 75. When k=1, the electric valve control device 70 compares the difference index value svE[1] and the difference judgment value HE, and also compares the difference index value svE[1]' calculated just before the difference index value svE[1] with the difference judgment value HE. The difference index value svE[1]' is calculated corresponding to the input of the pulse P[1] in the period T immediately preceding the current period T. When the difference index value svE[1] is smaller than the difference judgment value HE and the difference index value svE[1]' is smaller than the difference judgment value HE, the electric valve control device 70 determines that the electric valve 5 is in the first rotation restriction state Sr1. At this time, the electric valve control device 70 stores the number preceding k (i.e., 8) as the start pattern number Nx in the non-volatile memory 75. When the electric valve control device 70 does not determine that the electric valve 5 is in the first rotation restriction state Sr1, it determines that the electric valve 5 is in the first rotation allowable state Sp1.

[0304] <Judgment Method 3>

[0305] The electric valve control device 70 uses the first rotation allowance state table C[k] and the first rotation restriction state table E[k] to calculate the difference index values ​​svC[k] and svE[k] (S235). Specifically, the electric valve control device 70 uses the first rotation allowance state table C[1] to calculate the difference index value svC[1] and the first rotation restriction state table E[1] to calculate the difference index value svE[1] corresponding to the input of pulse P[1]. The electric valve control device 70 uses the first rotation allowance state table C[3] to calculate the difference index value svC[3] and the first rotation restriction state table E[3] to calculate the difference index value svE[3] corresponding to the input of pulse P[3]. The electric valve control device 70 uses the first rotation allowance state table C[5] to calculate the difference index value svC[5] and the first rotation restriction state table E[5] to calculate the difference index value svE[5] corresponding to the input of pulse P[5]. The electric valve control device 70 uses the first rotation allowable state table C[7] to calculate the difference index value svC[7] in correspondence with the input of pulse P[7], and uses the first rotation limit state table E[7] to calculate the difference index value svE[7].

[0306] The electric valve control device 70 determines the state of the electric valve 5 at the end of pulse P[k] (S240). Specifically, the electric valve control device 70 compares the difference index value svC[k] with the difference judgment value HC, and compares the difference index value svC[j] calculated just before the difference index value svC[k] with the difference judgment value HC. The electric valve control device 70 compares the difference index value svE[k] with the difference judgment value HE, and compares the difference index value svE[j] calculated just before the difference index value svE[k] with the difference judgment value HE. When the difference index value svC[k] is greater than or equal to the difference judgment value HC, the difference index value svC[j] is greater than or equal to the difference judgment value HC, the difference index value svE[k] is less than the difference judgment value HE, and the difference index value svE[j] is less than the difference judgment value HE, the electric valve control device 70 determines that the electric valve 5 is in the first rotation restriction state Sr1. At this time, the electric valve control device 70 uses the previous number of j as the starting pattern number Nx and stores it in the non-volatile memory 75. The electric valve control device 70 determines that the electric valve 5 is in the first rotation-allowed state Sp1 when it does not determine that the electric valve 5 is in the first rotation-limited state Sr1.

[0307] In determination method 3, the difference index values ​​svC[k] and svC[j] are the difference index values ​​for the first permissible rotation state, and the difference index values ​​svE[k] and svE[j] are the difference index values ​​for the first restricted rotation state. The difference determination value HC is the difference determination value for the first permissible rotation state. The difference determination value HE is the difference determination value for the first restricted rotation state. The difference determination value HC can be the same as or different from the difference determination value HE.

[0308] As a variation of determination method 3, the electric valve control device 70 may determine the state of the electric valve 5 using only the difference index values ​​svC[k] and svE[k], without using the difference index values ​​svC[j] and svE[j]. In this case, the electric valve control device 70 determines that the electric valve 5 is in the first rotation restriction state Sr1 when the difference index value svC[k] is greater than or equal to the difference determination value HC and the difference index value svE[k] is less than the difference determination value HE. At this time, the electric valve control device 70 stores the number preceding k as the start pattern number Nx in the non-volatile memory 75. The electric valve control device 70 determines that the electric valve 5 is in the first rotation allowable state Sp1 when neither of the two values ​​is determined to be in the first rotation restriction state Sr1.

[0309] As another variation of determination method 3, the electric valve control device 70 may determine the state of the electric valve 5 using only one of the waveforms of voltage VA and voltage VB. The electric valve control device 70 may also determine the state of the electric valve 5 using only the waveform of voltage VA corresponding to one of pulses P[3] and P[7]. The electric valve control device 70 may also determine the state of the electric valve 5 using only the waveform of voltage VB corresponding to one of pulses P[1] and P[5]. Preferably, the waveform used for determination has less noise.

[0310] For example, the electric valve control device 70 uses the first rotation allowable state table C[k] (k = 1, 7) and the first rotation limit state table E[k] to calculate the difference index value svC[k] and the difference index value svE[k] (S235). The electric valve control device 70 determines the state of the electric valve 5 at the end of the pulse P[k] (S240). Alternatively, k can be 3, 5, 1, 3, or 5, 7. Or, k can be one of 1, 3, 5, or 7.

[0311] Specifically, when k=7, the electric valve control device 70 compares the difference index value svC[7] and the difference judgment value HC, and compares the difference index value svC[7]' calculated just before the difference index value svC[7] with the difference judgment value HC. When k=7, the electric valve control device 70 compares the difference index value svE[7] and the difference judgment value HE, and compares the difference index value svE[7]' calculated just before the difference index value svE[7] with the difference judgment value HE. When the difference index value svC[7] is greater than or equal to the difference judgment value HC, the difference index value svC[7]' is slightly greater than or equal to the difference judgment value HC, the difference index value svE[7] is smaller than the difference judgment value HE, and the difference index value svE[7]' is smaller than the difference judgment value HE, the electric valve control device 70 determines that the electric valve 5 is in the first rotation restriction state Sr1. At this time, the electric valve control device 70 uses the number preceding k (i.e., 6) as the starting pattern number Nx and stores it in the non-volatile memory 75. When k=1, the electric valve control device 70 compares the difference index value svC[1] and the difference judgment value HC, and compares the difference index value svC[1]' calculated just before the difference index value svC[1] with the difference judgment value HC. When k=1, the electric valve control device 70 compares the difference index value svE[1] and the difference judgment value HE, and compares the difference index value svE[1]' calculated just before the difference index value svE[1] with the difference judgment value HE. When the difference index value svC[1] is greater than or equal to the difference judgment value HC, the difference index value svC[1]' is greater than or equal to the difference judgment value HC, the difference index value svE[1] is less than the difference judgment value HE, and the difference index value svE[1]' is less than the difference judgment value HE, the electric valve control device 70 determines that the electric valve 5 is in the first rotation restriction state Sr1. At this time, the electric valve control device 70 stores the previous number of k (i.e., 8) as the start pattern number Nx in the non-volatile memory 75. When the electric valve control device 70 does not determine that the electric valve 5 is in the first rotation restriction state Sr1, it determines that the electric valve 5 is in the first rotation allowable state Sp1.

[0312] Alternatively, at the time of manufacture of the electric valve device 1, an appropriate pattern number may be stored in the non-volatile memory 75 as the starting pattern number Nx of the electric valve 5. In this case, the electric valve control device 70 does not store the starting pattern number Nx in determination methods 1 to 3.

[0313] When the electric valve 5 is in the first rotation restriction state Sr1 (S250: Yes), the electric valve control device 70 ends the input of pulses P[1] to P[8] to the stepper motor 66 and notifies the air conditioning control device 110 of the end of the initialization action (S270).

[0314] When the electric valve 5 is in the first rotation-allowed state Sp1 (S250: No) and the number of pulses P input to the stepper motor 66 exceeds the initialization number X (S260: Yes), the electric valve control device 70 ends the input of pulses P to the stepper motor 66 and notifies the air conditioning control device 110 of the end of the initialization action (S270).

[0315] When the number of pulses P input to the stepper motor 66 is less than the initial number X (S260: No), the electric valve control device 70 acquires the voltage VA and voltage VB again (S230) and repeats the above operation (S230~S260).

[0316] When the initialization operation ends, the rotor 41 is positioned at the reference position Rx. When the electric valve control device 70 rotates the rotor 41, which is located at the reference position Rx, in the second direction, it inputs pulses P[1] to P[8] in descending order to the stepper motor 66. At this time, the electric valve control device 70 starts inputting pulses P from the pattern number that is the same as the starting pattern number Nx. For example, when the starting pattern number Nx is [7], the electric valve control device 70 starts inputting pulses P[7] in descending order.

[0317] Next, refer to Figure 32 , Figure 33 Another example (Action Example 2) of the initialization operation of the electric valve control device 70 will be explained.

[0318] In Operation Example 2, when the electric valve control device 70 determines that the initialization of the electric valve 5 is successful after restricting the rotation of the rotor 41 in the first direction, and then the initialization operation ends. In Operation Example 2, the electric valve control device 70 determines the state of the electric valve 5 more rigorously than in Operation Example 1.

[0319] In Action Example 2, the steps that perform the same (including substantially the same) actions as in Action Example 1 are marked with the same symbols, and detailed descriptions are omitted.

[0320] When the electric valve control device 70 (specifically, the computer 80) receives an initialization command from the air conditioning control device 110 (S210), it begins to input the ascending pulses P[1] to P[8] of the stepper motor 66 (S220). As a result, the initialization operation begins, the stator 60 is supplied with the drive current corresponding to the pulses P[1] to P[8], and the rotor 41 rotates in the first direction.

[0321] When the rotor 41 rotates in the first direction, the electric valve control device 70 sequentially acquires the voltage VA generated between terminals A1 and A2 of the coil 61c of the A-phase stator 61 and the voltage VB generated between terminals B1 and B2 of the coil 62c of the B-phase stator 62 (S230).

[0322] The electric valve control device 70 calculates the difference index value sv (S235) and determines the state of the electric valve 5 based on the difference index value sv (S240). The electric valve control device 70 uses any one of the determination methods 1 to 3 to determine the state of the electric valve 5.

[0323] When the electric valve 5 is in the first rotation-allowed state Sp1 (S250: No) and the number of pulses P input to the stepper motor 66 exceeds the initialization quantity X (S260: Yes), the electric valve control device 70 stops inputting pulses P to the stepper motor 66 and notifies the air conditioning control device 110 of the end of the initialization operation (initialization failure) (S270). In this case, due to factors such as wear of the stop mechanism 49, there is a possibility that the waveform of voltage VA or voltage VB may change in the electric valve 5, making it impossible for the electric valve control device 70 to correctly determine the state of the electric valve 5.

[0324] When the number of pulses P input to the stepper motor 66 is less than the initial number X (S260: No), the electric valve control device 70 acquires the voltage VA and voltage VB again (S230) and repeats the above operation (S230~S260).

[0325] When the electric valve 5 is in the first rotation restriction state Sr1 (S250: Yes), the electric valve control device 70 begins to input descending pulses P[1] to P[8] of the stepper motor 66 (S320). At this time, the electric valve control device 70 starts inputting pulse P with the same pattern number as the starting pattern number Nx. As a result, a drive current corresponding to pulses P[1] to P[8] is supplied to the stator 60, thereby causing the rotor 41 to rotate in the second direction.

[0326] When the rotor 41 rotates in the second direction, the electric valve control device 70 sequentially acquires voltages VA and VB (S330). In step S330, the electric valve control device 70 performs the same (including substantially the same) operation as in step S230.

[0327] The electric valve control device 70 calculates the difference index value sv (S335) and determines the state of the electric valve 5 based on the difference index value sv (S340).

[0328] The electric valve control device 70 uses the second rotation allowable state table D[k] (k = 1, 3, 5, 7) to calculate the difference index value svD[k] (S335). Specifically, the electric valve control device 70 uses the second rotation allowable state table D[1] to calculate the difference index value svD[1] corresponding to the input of pulse P[1]. The electric valve control device 70 uses the second rotation allowable state table D[3] to calculate the difference index value svD[3] corresponding to the input of pulse P[3]. The electric valve control device 70 uses the second rotation allowable state table D[5] to calculate the difference index value svD[5] corresponding to the input of pulse P[5]. The electric valve control device 70 uses the second rotation allowable state table D[7] to calculate the difference index value svD[7] corresponding to the input of pulse P[7].

[0329] The electric valve control device 70 determines the state of the electric valve 5 at the end of pulse P[k] (S340). Specifically, the electric valve control device 70 compares the difference index value svD[k] with the difference judgment value HD, and compares the difference index value svD[j] calculated just before the difference index value svD[k] (j=k-2 when k=3, 5, 7, j=7 when k=1) with the difference judgment value HD. The electric valve control device 70 determines that the electric valve 5 is in the second rotation restriction state Sr2 when both the difference index value svD[k] and the difference index value svD[j] are above the difference judgment value HD. The electric valve control device 70 determines that the electric valve 5 is in the second rotation permission state Sp2 when it does not determine that the electric valve 5 is in the second rotation restriction state Sr2.

[0330] The difference index values ​​svD[k] and svD[j] are the difference index values ​​for the second allowable rotational state. The difference judgment value HD is the difference judgment value for the second allowable rotational state. The difference judgment value HD can be the same as or different from the difference judgment value HC (or the difference judgment value HE).

[0331] Alternatively, the electric valve control device 70 may determine the state of the electric valve 5 using only the difference index value svD[k] instead of the difference index value svD[j]. In this case, the electric valve control device 70 determines that the electric valve 5 is in the second rotation restriction state Sr2 when the difference index value svD[k] is higher than the difference judgment value HD, and determines that the electric valve 5 is in the second rotation allowable state Sp2 when the difference index value svD[k] is lower than the difference judgment value HD.

[0332] Alternatively, the electric valve control device 70 may use only one of the waveforms of voltage VA and voltage VB to determine the state of the electric valve 5. The electric valve control device 70 may also use only the waveform of voltage VA corresponding to one of pulses P[3] and P[7] to determine the state of the electric valve 5. The electric valve control device 70 may also use only the waveform of voltage VB corresponding to one of pulses P[1] and P[5] to determine the state of the electric valve 5. Preferably, the waveform used for determination has less noise.

[0333] For example, the electric valve control device 70 uses the second rotational permissible state table D[k] (k = 1, 7) to calculate the difference index value svD[k] (S335). The electric valve control device 70 determines the state of the electric valve 5 at the end of the pulse P[k] (S340). Alternatively, k can be 3, 5, 1, 3, or 5, 7. Or, k can be one of 1, 3, 5, or 7.

[0334] Specifically, when k=7, the electric valve control device 70 compares the difference index value svD[7] and the difference judgment value HD, and compares the difference index value svD[7]' calculated just before the difference index value svD[7] with the difference judgment value HD. The difference index value svD[7]' is calculated corresponding to the input of the pulse P[7] in the period T before the current period T. When the difference index value svD[7] is higher than the difference judgment value HD and the difference index value svD[7]' is higher than the difference judgment value HD, the electric valve control device 70 determines that the electric valve 5 is in the second rotation restriction state Sr2. When k=1, the electric valve control device 70 compares the difference index value svD[1] and the difference judgment value HD, and compares the difference index value svD[1]' calculated just before the difference index value svD[1] with the difference judgment value HD. The difference index value svD[1]' is calculated corresponding to the input of the pulse P[1] in the period T immediately preceding the current period T. When the difference index value svD[1] is greater than or equal to the difference judgment value HD and the difference index value svD[1]' is greater than or equal to the difference judgment value HD, the electric valve control device 70 determines that the electric valve 5 is in the second rotation restriction state Sr2. When the electric valve control device 70 does not determine that the electric valve 5 is in the second rotation restriction state Sr2, it determines that the electric valve 5 is in the second rotation permission state Sp2.

[0335] When the electric valve 5 is in the second rotation restriction state Sr2 (S350: Yes), the electric valve control device 70 stops inputting pulses P[1] to P[8] to the stepper motor 66 and notifies the air conditioning control device 110 of the end of the initialization action (initialization failure) (S270). In this case, there is a possibility that the electric valve 5 will malfunction and the rotor 41 will not rotate in the first and second directions.

[0336] When the electric valve 5 is in the second rotation-allowed state Sp2 (S350: No) and the number of pulses P input to the stepper motor 66 reaches the reversal number Y (S360: Yes), the electric valve control device 70 inputs pulses P with the reversal number Y to the stepper motor 66 in ascending order (S370). As a result, the rotor 41 rotates in the first direction and stops at the reference position Rx. The reversal number Y is the number of pulses P required in the electric valve 5 to determine whether the rotor 41 can rotate in the second direction. For example, the reversal number Y is 16. Then, the electric valve control device 70 stops inputting pulses P to the stepper motor and notifies the air conditioning control device 110 that the initialization operation has ended (initialization successful) (S380).

[0337] When the number of pulses P input to the stepper motor 66 is less than the number of reversals Y (S360: No), the electric valve control device 70 acquires voltage VA and voltage VB again (S330) and repeats the above operation (S330~S360).

[0338] When the initialization operation is completed (initialization successful), the rotor 41 is positioned at the reference position Rx. When the electric valve control device 70 rotates the rotor 41, which is at the reference position Rx, in the second direction, it inputs pulses P[1] to P[8] in descending order to the stepper motor 66. At this time, the electric valve control device 70 starts inputting pulses P from the pattern number that is the same as the starting pattern number Nx.

[0339] The electric valve device 2 includes an electric valve 5 and an electric valve control device 70. It comprises: a valve body 10 having a valve seat 18; a rotor 41 rotatable relative to the valve body 10; a stator 60, which, together with the rotor 41, forms a stepper motor 66; a valve core 30 opposite to the valve seat 18 and moving toward the valve seat 18 when the rotor 41 rotates in a first direction; and a stop mechanism 49 that restricts the rotation of the rotor 41 in the first direction when the rotor 41 is at a reference position Rx. The electric valve control device 70 inputs a pulse P to the stepper motor 66 to rotate the rotor 41 in the first direction. The electric valve control device 70 acquires the voltages (voltage VA and voltage VB) generated in the stator 60 due to the rotation of the rotor 41. The electric valve control device 70 determines whether the electric valve 5 is in a first rotation restriction state Sr1, where the rotation of the rotor 41 in the first direction is restricted, based on the degree of difference between the voltage waveform and the reference voltage waveform.

[0340] Therefore, when the electric valve control device 70 determines that the electric valve 5, which is capable of normal operation, is in the first rotation restriction state Sr1, the rotor 41 is at the reference position Rx. Thus, when the electric valve control device 70 determines that the electric valve 5 is in the first rotation restriction state Sr1, by stopping the rotation of the rotor 41 in the first direction, the time required for initialization can be shortened. Furthermore, after the rotor 41 is positioned at the reference position Rx, noise generation over a long period can be suppressed. Additionally, the electric valve control device 70 determines the state of the electric valve 5 based on the degree of difference between the voltage waveform and the reference voltage waveform. Therefore, compared to structures that determine the state of the electric valve 5 based on the waveform area or the maximum amplitude of the waveform, the electric valve control device 70 can determine the state of the electric valve 5 with even higher accuracy.

[0341] Furthermore, the electric valve control device 70 determines whether the electric valve 5 is in the first rotation restriction state Sr1 based on the voltages (voltage VA and voltage VB) generated in the stator 60. Therefore, the electric valve control device 70 eliminates the need for components such as rotation angle sensors that determine the state of the electric valve 5 based on the rotation of the rotor 41, allowing for a simpler structure for both the electric valve control device 70 and the electric valve 5.

[0342] In addition, the reference waveform of voltage VA includes a first rotational allowable state waveform based on the waveform of voltage VA when a pulse P (first direction pulse) is input to the stepper motor 66 in the electric valve 5 in the first rotational allowable state Sp1, causing the rotor 41 to rotate in the first direction. The first rotational allowable state waveform of voltage VA is the first rotational allowable state table C[3] and C[7]. The reference waveform of voltage VB includes a first rotational allowable state waveform based on the waveform of voltage VB when a first direction pulse is input to the stepper motor 66 in the electric valve 5 in the first rotational allowable state Sp1. The first rotational allowable state waveform of voltage VB is the first rotational allowable state table C[1] and C[5]. The electric valve control device 70 calculates a difference index value svC (svC[3], svC[7]) indicating the degree of difference between the first rotational allowable state waveform of voltage VA and the waveform of voltage VA obtained according to the input of the first direction pulse to the stepper motor 66. The electric valve control device 70 calculates a difference index value svC (svC[1], svC[5]) representing the degree of difference between the waveform of the first rotational allowable state of voltage VB and the waveform of voltage VB obtained based on the input of the first direction pulse to the stepper motor 66. The electric valve control device 70 determines whether the electric valve 5 is in the first rotational restriction state Sr1 (determination method 1) based on the comparison result between the difference index value svC and the difference judgment value HC. Thus, the electric valve control device 70 can further determine the state of the electric valve 5 with high precision.

[0343] In addition, the reference waveform of voltage VA includes a first rotation limit state waveform set based on the waveform of voltage VA when a first direction pulse is input to stepper motor 66 in electric valve 5 in the first rotation limit state Sr1. The first rotation limit state waveform of voltage VA is the first rotation limit state table E[3] and E[7]. The reference waveform of voltage VB includes a first rotation limit state waveform set based on the waveform of voltage VB when a first direction pulse is input to stepper motor 66 in electric valve 5 in the first rotation limit state Sr1. The first rotation limit state waveform of voltage VB is the first rotation allowable state table E[1] and E[5]. The electric valve control device 70 calculates a difference index value svE (svE[3], svE[7]) indicating the degree of difference between the first rotation limit state waveform of voltage VA and the waveform of voltage VA obtained according to the input of the first direction pulse to stepper motor 66. The electric valve control device 70 calculates a difference index value svE (svE[1], svE[5]) representing the degree of difference between the waveform of the first rotation limit state of voltage VB and the waveform of voltage VB obtained based on the input of the first direction pulse to the stepper motor 66. The electric valve control device 70 determines whether the electric valve 5 is in the first rotation limit state Sr1 (determination method 2) based on the comparison result between the difference index value svE and the difference judgment value HE. Thus, the electric valve control device 70 can further determine the state of the electric valve 5 with high precision.

[0344] In addition, the reference waveform of voltage VA includes the first rotation-allowed state waveform and the first rotation-limited state waveform. The reference waveform of voltage VB includes the first rotation-allowed state waveform and the first rotation-limited state waveform. The electric valve control device 70 calculates the difference index value svC (svC[3], svC[7], svC[1], svC[5]). The electric valve control device 70 calculates the difference index value svE (svE[3], svE[7], svE[1], svE[5]). The electric valve control device 70 determines whether the electric valve 5 is in the first rotation-limited state Sr1 (determination method 3) based on the comparison result of the difference index value svC and the difference judgment value HC and the comparison result of the difference index value svE and the difference judgment value HE. Thus, the electric valve control device 70 can further determine the state of the electric valve 5 with high precision.

[0345] Furthermore, when the electric valve control device 70 determines that the electric valve 5 is in the first rotation restriction state Sr1, it stops inputting pulse P to the stepper motor 66. Compared to a structure that, for example, notifies the air conditioning control device 110 that the electric valve 5 is in the first rotation restriction state Sr1, and receives a stop command from the air conditioning control device 110 to stop the initialization operation, the electric valve control device 70 can simply and quickly stop the rotation of the rotor 41 in the first direction.

[0346] In addition, the reference waveform of voltage VA includes a second rotation allowable state waveform based on the waveform of voltage VA when a pulse P (second direction pulse) is input to the stepper motor 66 in the electric valve 5, which is in the second rotation allowable state Sp2, causing the rotor 41 to rotate in the second direction. The second rotation allowable state waveform of voltage VA is the second rotation allowable state table D[3] and D[7]. The reference waveform of voltage VB includes a second rotation allowable state waveform based on the waveform of voltage VB when a second direction pulse is input to the stepper motor 66 in the electric valve 5, which is in the second rotation allowable state Sp2. The second rotation allowable state waveform of voltage VB is the second rotation allowable state table D[1] and D[5]. When the electric valve control device 70 determines that the electric valve 5 is in the first rotation restriction state Sr1, it inputs a pulse P to the stepper motor 66 to cause the rotor 41 to rotate in the second direction. The electric valve control device 70 calculates a difference index value svD (svD[3], svD[7]) representing the degree of difference between the second rotational allowable state waveform of voltage VA and the waveform of voltage VA obtained based on the input of the second direction pulse to the stepper motor 66. The electric valve control device 70 calculates a difference index value svD (svD[1], svD[5]) representing the degree of difference between the second rotational allowable state waveform of voltage VB and the waveform of voltage VB obtained based on the input of the second direction pulse to the stepper motor 66. The electric valve control device 70 determines whether the electric valve 5 is in the second rotational restriction state Sr2 based on the comparison result of the difference index value svD and the difference judgment value HD. When the electric valve control device 70 determines that the electric valve 5 is in the second rotational restriction state Sr2, it stops inputting the pulse P to the stepper motor 66. At this time, the electric valve 5 is trapped in a state where the rotor 41 can neither rotate in the first direction nor in the second direction (fault state). When the electric valve control device 70 determines that the electric valve 5 is in the first rotation restriction state Sr1, and the number of pulses P input to the stepper motor 66 reaches the number of reverse rotations Y, it inputs pulses P with the number of reverse rotations Y to the stepper motor, causing the rotor 41 to rotate in the first direction. Thus, the electric valve control device 70 can detect when the electric valve 5 is in a faulty state.

[0347] The first rotation-allowed state waveform is a data table (first rotation-allowed state table C) that associates time t with a reference voltage rv at time t, set for the first direction pulse. The first rotation-limited state waveform is a data table (first rotation-limited state table E) that associates time t with a reference voltage rv at time t, set for the first direction pulse. The electric valve control device 70 sequentially acquires voltage v (voltage VA, voltage VB) when the first direction pulse is input to the stepper motor 66. When the electric valve control device 70 acquires voltage v at acquisition time tv corresponding to the input of the first direction pulse, it calculates the value (first intermediate value Dv2_1) obtained by squaring the difference Dv between the voltage v and the reference voltage rv, which is associated with time t corresponding to the acquisition time tv in the data table set for the first direction pulse input to the stepper motor 66. The electric valve control device 70 adds multiple first intermediate values ​​Dv2_1 calculated using the voltage v acquired corresponding to the input of the first direction pulse to calculate the difference index value svC and the difference index value svE. The difference index values ​​svC and svE are calculated using the formula (1) above. Thus, unlike the waveform area and maximum amplitude, the difference index values ​​svC and svE appropriately reflect the degree of difference in the waveform shape. Therefore, the electric valve control device 70 can further determine the state of the electric valve 5 with high precision.

[0348] The second rotational allowable state waveform is a data table (second rotational allowable state table D) that associates time t with a reference voltage rv at time t, set for the second direction pulse. The electric valve control device 70 sequentially acquires voltage v (voltage VA, voltage VB) when the second direction pulse is input to the stepper motor 66. Corresponding to the input of the second direction pulse, when acquiring voltage v at acquisition time tv, the electric valve control device 70 calculates the value obtained by squaring the difference Dv between the voltage v and the reference voltage rv (second intermediate value Dv2_2), which is associated with time t corresponding to the acquisition time tv in the data table set for the second direction pulse input to the stepper motor 66. The electric valve control device 70 adds multiple first intermediate values ​​Dv2_2 calculated using the voltage v acquired corresponding to the input of the second direction pulse to calculate the difference index value svD. The difference index value svD is calculated using the above formula (1). Thus, unlike the waveform area and the maximum amplitude of the waveform, the difference index value svD appropriately reflects the degree of difference in the waveform shape. Therefore, the electric valve control device 70 can further determine the state of the electric valve 5 with high precision.

[0349] The difference index values ​​(svC, svD, svE) are not limited to being calculated using the formula (1) above. For example, the difference index value can also be the shift in the magnitude of the voltage v at each acquisition time tv. Specifically, when the electric valve control device 70 acquires the voltage v at acquisition time tv corresponding to the input of pulse P (first direction pulse, second direction pulse), it calculates the difference Dv between the voltage v and the reference voltage rv, which is associated with the time t corresponding to the acquisition time tv in the data table set for the pulse P input to the stepper motor 66. The difference Dv is calculated as an absolute value. The electric valve control device 70 uses the number of differences Dv calculated using the voltage v acquired corresponding to the input of pulse P that exceed a predetermined difference judgment value as the difference index value. Such a difference index value appropriately reflects the degree of difference in the waveform shape. Alternatively, the difference index value can also be the shift in the slope of the voltage v at each acquisition time tv. The difference index value is preferably a value that reflects a timing element.

[0350] Furthermore, the electric valve control device 70 calculates the difference index values ​​svC and svE by adding multiple first intermediate values ​​Dv2_1. These multiple first intermediate values ​​Dv2_1 are calculated using voltage v acquired during a second period P2, which is part of the period from the start to the end of the first direction pulse. The voltage component in voltage v during the second period P2 that involves the back electromotive force caused by the inductance of the stator 60 is smaller than the voltage component in voltage v that involves the electromagnetic induction caused by the rotation of the rotor 41. As a result, the latter voltage component has a larger proportion in voltage v, allowing the electric valve control device 70 to determine the state of the electric valve 5 with high accuracy.

[0351] Furthermore, the electric valve control device 70 calculates the difference index value svD by adding multiple second intermediate values ​​Dv2_2. These multiple first intermediate values ​​Dv2_2 are calculated using the voltage v acquired during a second period P2, which is part of the period from the start to the end of the second direction pulse. The voltage component in the voltage v during the second period P2 that involves the back electromotive force caused by the inductance of the stator 60 is smaller than the voltage component in the voltage v that involves the electromagnetic induction caused by the rotation of the rotor. As a result, the latter voltage component has a larger proportion in the voltage v, allowing the electric valve control device 70 to determine the state of the electric valve 5 with higher accuracy.

[0352] Furthermore, when the electric valve control device 70 determines that the electric valve 5 is in the first rotation restriction state Sr1, it obtains a starting pattern number Nx based on the pattern number of the first direction pulse corresponding to the waveforms of the voltage VA and voltage VB used for this determination. When the electric valve control device 70 rotates the rotor 41, which is located at the reference position Rx, in the second direction, it inputs pulses P starting from the pulse with the same pattern number as the starting pattern number Nx in descending order. As a result, the electric valve control device 70 can further control the position of the rotor 41 with high precision.

[0353] Furthermore, in the electric valve control device 70, the first rotation limit state waveform is set for the first direction pulse based on the waveforms of multiple voltages (the waveforms of voltage VA and voltage VB) pre-acquired in the electric valve 5 coupled with the electric valve control device 70. One first rotation limit state waveform is set for each first direction pulse. Thus, the electric valve control device 70 sets an optimal first rotation limit state waveform for the electric valve 5 coupled with it. Therefore, the electric valve control device 70 can further determine the state of the electric valve 5 with high accuracy.

[0354] Furthermore, in the electric valve control device 70, the first rotation limiting state waveform is set for the first direction pulse based on the waveforms of multiple voltages (the waveforms of voltage VA and voltage VB) pre-acquired in multiple electric valves 5. In this case, multiple first rotation limiting state waveforms that are different from each other are set for one first direction pulse. The number of first rotation limiting state waveforms set for one first direction pulse is the same as the number of pulse P patterns (eight). The first rotation limiting state waveform set for one first direction pulse is set based on the waveforms of voltages acquired in multiple electric valves 5 that are different from each other at the time point when the rotation of rotor 41 in the first direction is limited by the stop mechanism 49. Thus, it is not necessary to acquire the voltage waveforms individually in each electric valve 5 at the time of shipment, which can reduce the manufacturing time of the electric valve device 1.

[0355] Furthermore, the stator 60 has an A-phase stator 61 and a B-phase stator 62. The electric valve control device 70 obtains the voltage VB generated in the B-phase stator 62 when only the drive current is supplied to the A-phase stator 61, and obtains the voltage VA generated in the A-phase stator 61 when only the drive current is supplied to the B-phase stator 62. Therefore, in the electric valve control device 70, it is not necessary to separate the voltage component involved in electromagnetic induction from the voltage generated in the A-phase stator 61, nor is it necessary to separate the voltage component involved in electromagnetic induction from the voltage generated in the B-phase stator 62. Thus, voltages VA and VB can be obtained with a relatively simple structure.

[0356] Furthermore, the valve core 30 is opposite the valve seat 18, and when the rotor 41 rotates in the first direction, it is pressed against the valve seat 18 via the valve closing spring 47. The reference position of the rotor 41 is located further in the first direction than the valve closing position Rc where the valve seat 18 contacts the valve core 30. As a result, the force pressing the valve core 30 against the valve seat 18 by the valve closing spring 47 is mitigated, and the situation where the valve core 30 is pressed against the valve seat 18 due to excessive force can be prevented.

[0357] In the electric valve control device 70, the reference waveforms of voltage VA and voltage VB are preset. The electric valve control device 70 can also update the voltage reference waveforms based on the voltage waveforms (waveforms of voltage VA and voltage VB) acquired during the operation of the electric valve 5.

[0358] Furthermore, the electric valve control device 70 determines whether the electric valve 5 is in the first rotation restriction state Sr1 based on the voltage generated in the stator 60 due to the rotation of the rotor 41. Since current and voltage are closely related, the electric valve control device 70 can also determine whether the electric valve 5 is in the first rotation restriction state Sr1 based on the current generated in the stator 60 due to the rotation of the rotor 41. In this structure, the electric valve control device 70 has a current acquisition unit instead of a voltage acquisition unit, which acquires the current generated in the stator 60 due to the rotation of the rotor 41 (the current electromagnetically induced by the stator 60). Then, the state determination unit determines whether the electric valve 5 is in the first rotation restriction state Sr1 based on the degree of difference between the current waveform and the current reference waveform.

[0359] In this specification, terms such as "cylinder" and "cylindrical" that indicate shape are also used for parts or portions of parts that substantially have the shape described by that term. For example, "cylindrical-shaped part" includes both cylindrical-shaped parts and parts that are substantially cylindrical in shape.

[0360] While embodiments of the present invention have been described above, the present invention is not limited to these examples. Structures obtained by adding, deleting, or modifying structural elements of the above embodiments, or by appropriately combining features of the embodiments, without departing from the spirit of the present invention, are also included within the scope of the present invention.

[0361] Symbol Explanation

[0362] 1…Electric valve device, 5…Electric valve, 10…Valve body, 11…Main body component, 11a…Matching hole, 11b…Through hole, 11d…Plane, 13…Connecting component, 14…Valve chamber, 15…First conduit, 16…Second conduit, 17…Valve port, 18…Valve seat, 20…Housing, 30…Valve core, 31…First shaft, 32…Second shaft, 33…Valve part, 34…Step, 40…Drive mechanism, 41…Rotor, 41a…Matching hole, 42…Valve shaft retainer Frame, 42a…Upper wall, 42b…Shaft hole, 42c…Internal thread, 42s…Modible stop, 43…Guide bushing, 43a…Base, 43b…Support, 43c…External thread, 43d…Flat surface, 44…Stop component, 44a…Stop body, 44c…Internal thread, 44s…Fixed stop, 45…Fixed component, 45a…Fixed part, 45b…Flange, 46…Washer, 47…Closing valve spring, 48…Return spring, 49…Stop mechanism, 60… Stator, 61…A-phase stator, 61a…pole tooth, 61b…pole tooth, 61c…coil, 62…B-phase stator, 62a…pole tooth, 62b…pole tooth, 62c…coil, 66…stepper motor, 70…electric valve control device, 71…board, 75…non-volatile memory, 76…communication device, 77…motor driver, 80…computer, 81…rotation control unit, 82…voltage acquisition unit, 83…status determination unit, 100…air conditioning system, 101…pressure Compressor, 102…Condenser, 103…Evaporator, 110…Air conditioning control unit, 120…Wired communication bus, A1…Terminal, A2…Terminal, B1…Terminal, B2…Terminal, L…Axis, P…Pulse, Rc…Closed valve position, Ro…Open valve position, Rx…Reference position, Sp…Rotation allowable state, Sq…Intermediate state, Sr…Rotation limit state, T…Period, tc…Time, tx…Time, VA…Voltage, VB…Voltage, X…Initialization quantity;

[0363] 2… Electric valve device, C… First rotation allowable state table, D… Second rotation allowable state table, E… First rotation restriction state table, H, HC, HD, HE… Difference determination value, sv, svC, svD, svE… Difference index value, Nx… Start pattern number, p1… First period, p2… Second period, Sp1… First rotation allowable state, Sp2… Second rotation allowable state, Sr1… First rotation restriction state, Sr2… Second rotation restriction state, Y… Reversal number.

Claims

1. An electric valve control device for controlling an electric valve, the electric valve comprising: a valve body having a valve seat; a rotor rotatable relative to the valve body; a stator forming a stepper motor together with the rotor; a valve core opposite to the valve seat, the valve core moving toward the valve seat when the rotor rotates in a first direction; and a stop mechanism restricting rotation of the rotor in the first direction when the rotor is in a reference position, characterized in that... have: A rotation control unit that inputs pulses to the stepper motor to cause the rotor to rotate in the first direction; A voltage acquisition unit acquires the voltage generated in the stator due to the rotation of the rotor; as well as The state determination unit determines whether the electric valve is in a first rotation restriction state in which the rotation of the rotor in the first direction is restricted, based on the degree of difference between the waveform of the voltage and the reference waveform of the voltage.

2. The electric valve control device according to claim 1, characterized in that, The reference waveform includes a first rotation-allowed state waveform, which is set based on the waveform of the voltage when the electric valve is in a state that allows the rotor to rotate in the first direction, and the stepper motor is input with the pulse that causes the rotor to rotate in the first direction. Hereinafter, the pulse that causes the rotor to rotate in the first direction will be referred to as the "first direction pulse". The state determination unit calculates a difference index value and determines whether the electric valve is in the first rotation restriction state based on the comparison result between the difference index value and the difference determination value. The difference index value indicates the degree of difference between the waveform of the first rotation permission state and the waveform of the voltage obtained by the voltage acquisition unit corresponding to the input of the first direction pulse of the stepper motor.

3. The electric valve control device according to claim 1, characterized in that, The reference waveform includes a first rotation limiting state waveform, which is set based on the waveform of the voltage when the electric valve is in a state that limits the rotation of the rotor in the first direction, and the stepper motor is input with the pulse that causes the rotor to rotate in the first direction. Hereinafter, the pulse that causes the rotor to rotate in the first direction will be referred to as the "first direction pulse". The state determination unit calculates a difference index value and determines whether the electric valve is in the first rotation restriction state based on the comparison result between the difference index value and the difference determination value. The difference index value indicates the degree of difference between the waveform of the first rotation restriction state and the waveform of the voltage obtained by the voltage acquisition unit corresponding to the input of the first direction pulse of the stepper motor.

4. The electric valve control device according to claim 1, characterized in that, The reference waveform includes: The first rotation-allowed state waveform is set based on the waveform of the voltage when the electric valve is in a state that allows the rotor to rotate in the first direction, and the pulse that causes the rotor to rotate in the first direction is input to the stepper motor. Hereinafter, the pulse that causes the rotor to rotate in the first direction will be referred to as the "first direction pulse". as well as The first rotation limiting state waveform is set based on the voltage waveform when a pulse in the first direction is input to the stepper motor when the electric valve is in a state that limits the rotation of the rotor in the first direction. The state determination unit The difference index value is calculated to represent the degree of difference between the waveform of the first rotational allowable state and the waveform of the voltage obtained by the voltage acquisition unit corresponding to the input of the first direction pulse of the stepper motor. This value is referred to as the "first rotational allowable state difference index value". A difference index value is calculated to represent the degree of difference between the waveform of the first rotation restriction state and the waveform of the voltage acquired by the voltage acquisition unit corresponding to the input of the first direction pulse of the stepper motor. This value is hereinafter referred to as the "first rotation restriction state difference index value". Based on the comparison results of the first rotational allowable state difference index value and the first rotational allowable state difference judgment value and the comparison results of the first rotational restriction state difference index value and the first rotational restriction state difference judgment value, it is determined whether the electric valve is in the first rotational restriction state.

5. The electric valve control device according to claim 1, characterized in that, When the state determination unit determines that the electric valve is in the first rotation restriction state, the rotation control unit stops inputting the pulse to the stepper motor.

6. The electric valve control device according to any one of claims 2 to 4, characterized in that, The reference waveform includes a second rotation-allowed state waveform, which is set based on the waveform of the voltage when the electric valve is in a state that allows the rotor to rotate in a second direction, and the stepper motor is input with the pulse that causes the rotor to rotate in the second direction. Hereinafter, the pulse that causes the rotor to rotate in the second direction will be referred to as the "second direction pulse". When the state determination unit determines that the electric valve is in the first rotation restriction state, the rotation control unit inputs the pulse to the stepper motor to cause the rotor to rotate in the second direction. The state determination unit calculates a difference index value, hereinafter referred to as the "second rotational allowable state difference index value," representing the degree of difference between the waveform of the second rotational allowable state and the waveform of the voltage obtained by the voltage acquisition unit corresponding to the input of the second direction pulse of the stepper motor. Based on the comparison result between the second rotational allowable state difference index value and the second rotational allowable state difference determination value, it determines whether the electric valve is in a second rotational restriction state in which the rotation of the rotor in the second direction is restricted. When the state determination unit determines that the electric valve is in the second rotation restriction state, the rotation control unit stops inputting the pulse to the stepper motor. After the state determination unit determines that the electric valve is in the first rotation restriction state, when the number of pulses input to the stepper motor reaches the number of reversals, the rotation control unit inputs the number of pulses of the number of reversals to the stepper motor to make the rotor rotate in the first direction.

7. The electric valve control device according to any one of claims 2 to 4, characterized in that, The reference waveform is a data table that sets the time for the first direction pulse and associates the time with the reference voltage at that time. When the first direction pulse is input to the stepper motor, the voltage acquisition unit acquires the voltage in a timely manner. When the voltage acquisition unit acquires the voltage at the acquisition time corresponding to the input of the first direction pulse, the state determination unit calculates a value obtained by squaring the difference between the voltage and the reference voltage, hereinafter referred to as the "first intermediate value". The reference voltage is associated with the acquisition time corresponding to the acquisition time in the data table set for the first direction pulse input to the stepper motor. The state determination unit adds up a plurality of the first intermediate values ​​to calculate the difference index value, and the plurality of the first intermediate values ​​are calculated using the voltage obtained by the voltage acquisition unit in correspondence with the input of the first direction pulse.

8. The electric valve control device according to claim 6, characterized in that, The reference waveform is a data table that sets the time for the second-direction pulse and associates the time with the reference voltage at that time. When the second direction pulse is input to the stepper motor, the voltage acquisition unit acquires the voltage in a timely manner. When the voltage acquisition unit acquires the voltage at the acquisition time corresponding to the input of the second direction pulse, the state determination unit calculates a value obtained by squaring the difference between the voltage and the reference voltage, hereinafter referred to as the "second intermediate value". The reference voltage is associated with the acquisition time corresponding to the acquisition time in the data table set for the second direction pulse input to the stepper motor. The state determination unit adds up a plurality of second intermediate values ​​to calculate the difference index value, and the plurality of second intermediate values ​​are calculated using the voltage obtained by the voltage acquisition unit in correspondence with the input of the second direction pulse.

9. The electric valve control device according to claim 7, characterized in that, The state determination unit adds up a plurality of the first intermediate values ​​to calculate the difference index value. The plurality of first intermediate values ​​are calculated using the voltage acquired by the voltage acquisition unit during a portion of the period from the start to the end of the first direction pulse. The voltage component involved in the back electromotive force due to the inductance of the stator contained in the voltage during the period is smaller than the voltage component involved in the electromagnetic induction caused by the rotation of the rotor contained in the voltage.

10. The electric valve control device according to claim 8, characterized in that, The state determination unit adds up a plurality of second intermediate values ​​to calculate the difference index value. These plurality of second intermediate values ​​are calculated using the voltage acquired by the voltage acquisition unit during a portion of the period from the start to the end of the second direction pulse. The voltage component involved in the back electromotive force due to the inductance of the stator contained in the voltage during the period is smaller than the voltage component involved in the electromagnetic induction caused by the rotation of the rotor contained in the voltage.

11. The electric valve control device according to any one of claims 2 to 4, characterized in that, When the state determination unit determines that the electric valve is in the first rotation restriction state, a start pattern number is obtained based on the pattern number of the first direction pulse corresponding to the waveform of the voltage used for the determination. When the rotation control unit rotates the rotor, which is located at the reference position, in the second direction, the pulse with the same pattern number as the starting pattern number is input.

12. The electric valve control device according to claim 3 or 4, characterized in that, Based on the waveforms of a plurality of voltages pre-acquired in the electric valve combined with the electric valve control device, the first rotation limit state waveform is set for the first direction pulse. For each first direction pulse, a first rotation limit state waveform is set.

13. The electric valve control device according to claim 3 or 4, characterized in that, Based on the waveforms of the multiple voltages pre-acquired in the multiple electric valves, the first rotation limit state waveform is set for the first direction pulse. For a given first direction pulse, set multiple first rotation limit state waveforms that are different from each other. The number of first rotation limit state waveforms set for a first direction pulse is the same as the number of pulse patterns. The first rotation restriction state waveform set for a first direction pulse is set based on the waveform of the voltage obtained from a plurality of electric valves that are different from each other at the time point corresponding to the pulse that restricts the rotation of the rotor in the first direction by the stop mechanism.

14. The electric valve control device according to any one of claims 1 to 4, characterized in that, The stator has an A-phase stator and a B-phase stator. When the rotation control unit supplies drive current to only one of the A-phase stator and the B-phase stator in accordance with the pulse input to the stepper motor, the voltage acquisition unit acquires the voltage generated by the other of the A-phase stator and the B-phase stator.

15. The electric valve control device according to any one of claims 1 to 4, characterized in that, The valve core is opposite to the valve seat. When the rotor rotates in the first direction, the valve core is pressed towards the valve seat via a helical spring. The reference position is located at a position where the rotor has rotated further in the first direction compared to the valve-closed position where the valve core contacts the valve seat.

16. An electric valve control device for controlling an electric valve, the electric valve comprising: a valve body having a valve seat; a rotor rotatable relative to the valve body; a stator forming a stepper motor together with the rotor; a valve core opposite to the valve seat, the valve core moving toward the valve seat when the rotor rotates in a first direction; and a stop mechanism restricting rotation of the rotor in the first direction when the rotor is in a reference position, characterized in that... have: A rotation control unit that inputs pulses to the stepper motor to cause the rotor to rotate in the first direction; A current acquisition unit acquires the current generated in the stator due to the rotation of the rotor; as well as The state determination unit determines whether the electric valve is in a first rotation restriction state in which the rotation of the rotor in the first direction is restricted, based on the degree of difference between the waveform of the current and the reference waveform of the current.

17. An electric valve device, characterized in that, It has the electric valve control device and the electric valve as described in claim 1 or claim 16.

18. A method for controlling an electric valve, the electric valve comprising: a valve body having a valve seat; a rotor rotatable relative to the valve body; a stator constituting a stepper motor together with the rotor; a valve core opposite to the valve seat, the valve core moving toward the valve seat when the rotor rotates in a first direction; and a stop mechanism restricting rotation of the rotor in the first direction when the rotor is in a reference position, characterized in that... A pulse is input to the stepper motor to cause the rotor to rotate in the first direction. Obtain the voltage generated in the stator due to the rotation of the rotor. The degree of difference between the waveform of the voltage and the reference waveform of the voltage is used to determine whether the electric valve is in a first rotation restriction state in which the rotation of the rotor in the first direction is restricted.

19. A method for controlling an electric valve, the electric valve comprising: a valve body having a valve seat; a rotor rotatable relative to the valve body; a stator forming a stepper motor together with the rotor; a valve core opposite to the valve seat, the valve core moving toward the valve seat when the rotor rotates in a first direction; and a stop mechanism restricting rotation of the rotor in the first direction when the rotor is in a reference position, characterized in that... A pulse is input to the stepper motor to cause the rotor to rotate in the first direction. To obtain the current generated in the stator due to the rotation of the rotor. The degree of difference between the waveform of the current and the reference waveform of the current is used to determine whether the electric valve is in a first rotation restriction state in which the rotation of the rotor in the first direction is restricted.

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