JP2022171289A - Motor valve controller and motor valve control program - Google Patents

Abstract

To detect step-out in a stepping motor used in a motor valve.SOLUTION: A motor valve controller comprises: a stepping motor that rotates a rotor; a rotation instruction unit that is connected to a motor valve having a mechanism for changing the rotary motion of the rotor into the axial motion of a valve body and a sensor for measuring an angle of the rotor, and instructs the stepping motor to indicate the angle; a rotation detection unit that acquires the angle of the rotor from the sensor; and a step-out detection unit that determines a step-out when the difference between the rotor angle and the angle instructed to the stepping motor deviates from a reference range.SELECTED DRAWING: Figure 13

Description

TECHNICAL FIELD The present invention relates to an electrically operated valve, and more particularly to a rotor control method.

An automobile air conditioner is generally configured by arranging a compressor, a condenser, an expansion device, an evaporator, etc. in a refrigeration cycle. A refrigerating cycle is provided with various control valves, such as an expansion valve as an expansion device, for controlling the flow of refrigerant. 2. Description of the Related Art With the recent spread of electric vehicles and the like, electrically operated valves having a motor as a drive unit are being widely used.

As such an electric valve, there is known one that includes a magnetic sensor for detecting the degree of opening of the valve (see Patent Document 1, for example). A valve body is provided at one end of an operating rod that rotates with the rotor, and a magnet (sensor magnet) is provided at the other end. A magnetic sensor is provided so as to face the sensor magnet in the axial direction. Rotational motion of the rotor is converted into axial motion of the valve body by the screw feed mechanism. By capturing the change in magnetic flux accompanying the rotation of the rotor with a magnetic sensor, the rotation angle of the sensor magnet and thus the axial position of the valve body can be detected, and the valve opening can be calculated.

A reference position, which serves as a control reference, is set for the valve body that moves up and down in the electric valve. When the rotor continues to rotate in the valve closing direction and reaches a reference position also called an "origin", the rotation of the rotor is restricted by a stopper (see Patent Document 2, for example).

Japanese Patent Application Laid-Open No. 2018-135908 JP 2020-204344 A

Stepper motors used to rotate the rotor can sometimes get out of step. Loss of synchronism is a phenomenon in which rotation induction in a stepping motor is lost due to sudden speed change or overload. When step-out occurs, the rotor cannot be rotated normally. Therefore, in order to guarantee the operation of the motor-operated valve, it is necessary to correctly detect stepping out of the stepping motor and notify the external device.

As a conventional technique, there is known a method of monitoring the current applied to the stepping motor and determining that the stepping motor has stepped out when a change in induced electromotive force that occurs at the time of stepping out is detected. However, with this method, there is a problem that step-out is overlooked when there is no obvious change in the induced electromotive force. Further, in the case of Patent Document 1, although it is possible to detect the rotation angle with a magnetic sensor, it is not detected whether or not the rotation angle is caused by step-out.

SUMMARY OF THE INVENTION A main object of the present invention is to provide a technique for detecting step-out in a stepping motor used in an electric valve.

A motor-operated valve control device according to one aspect of the present invention is connected to a motor-operated valve having a stepping motor that rotates a rotor, a mechanism that converts the rotary motion of the rotor into axial motion of a valve body, and a sensor that measures the angle of the rotor. When the difference between the rotor angle and the angle instructed to the stepping motor is out of the reference range , and a step-out detection unit for determining a step-out.

A motor-operated valve control program according to one aspect of the present invention is connected to a motor-operated valve having a stepping motor that rotates a rotor, a mechanism that changes the rotational motion of the rotor into axial motion of the valve body, and a sensor that measures the angle of the rotor. When the difference between the rotor angle and the angle instructed to the stepping motor is out of the reference range, and a function of determining out-of-step.

According to the present invention, it is possible to detect step-out in a stepping motor used in an electric valve.

1 is a cross-sectional view showing an electrically operated valve according to an embodiment; FIG. FIG. 3 is a diagram showing the configuration of a stator and its surroundings; It is a figure showing the structure of a rotor. FIG. 2 is a schematic diagram showing the relationship between a magnetic sensor, a sensor magnet, and magnetic lines of force generated from the sensor magnet; It is a top view of a sensor magnet. 4 is a graph showing the relationship between the sensor value of the sensor magnet and the sensing angle; 4 is a graph showing the relationship between an angle value (duty ratio) and steps. FIG. 4 is a schematic diagram of the movement range of the rotor; 4 is a graph showing the relationship between steps and an ideal rotor angle; 4 is a graph showing changes in drive torque; FIG. 10 is a diagram showing the reference value of the step difference and the reference value of the mechanical angle difference in each scene; FIG. 10 is a diagram showing a truth table of logical operation Z; 7 is a graph showing an example of determination of out-of-step and synchronization. It is a functional block diagram of an electric valve control device. 4 is a flow chart showing a main processing process; 4 is a flow chart showing a main processing process; 4 is a flow chart showing a step-out determination process for each scene;

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the following description, for the sake of convenience, the positional relationship of each structure may be expressed based on the illustrated state. Also, in the following embodiments and modifications thereof, substantially the same constituent elements are denoted by the same reference numerals, and description thereof will be omitted as appropriate.

FIG. 1 is a cross-sectional view showing an electrically operated valve according to an embodiment.
The motor-operated valve 1 is applied to a refrigerating cycle of an automotive air conditioner (not shown). This refrigeration cycle includes a compressor that compresses the circulating refrigerant, a condenser that condenses the compressed refrigerant, an expansion valve that throttles and expands the condensed refrigerant and delivers it in the form of mist, and an evaporator that evaporates the refrigerant in the form of mist. An evaporator or the like is provided to cool the air in the passenger compartment by the latent heat of evaporation. Motor operated valve 1 functions as an expansion valve for the refrigeration cycle.

A motor-operated valve 1 is configured by assembling a valve body 2 and a motor unit 3 . The valve main body 2 has a body 5 that accommodates a valve portion. The body 5 functions as a "valve body". The body 5 is configured by assembling a first body 6 and a second body 8 coaxially. Both the first body 6 and the second body 8 are made of stainless steel (hereinafter referred to as "SUS"). Since the valve seat 24 is provided in the second body 8, a material with excellent wear resistance is selected. The first body 6 has better weldability than the second body 8 , and the second body 8 has better workability than the first body 6 .

The first body 6 has a stepped cylindrical shape whose outer diameter gradually decreases downward. The outer diameter of the upper end portion of the first body 6 is slightly reduced, and a locking portion 52 is formed by a step. A male thread 10 is formed on the lower outer peripheral surface of the first body 6 for assembling the electric valve 1 to a piping body (not shown). A pipe extending from the condenser side, a pipe leading to the evaporator, and the like are connected to the pipe body, but the details thereof will not be described. A seal accommodating portion 12 consisting of an annular groove is formed on the outer peripheral surface of the first body 6 slightly above the male thread 10, and a seal ring 14 (O-ring) is fitted.

A circular hole-shaped concave fitting portion 16 is provided in the lower portion of the first body 6 . The second body 8 has a cylindrical shape with a bottom, and its upper portion is press-fitted into the concave fitting portion 16 . A seal accommodating portion 18 consisting of an annular groove is formed in the lower outer peripheral surface of the second body 8, and a seal ring 20 is fitted therein. A valve hole 22 is provided so as to axially penetrate the bottom of the second body 8 , and a valve seat 24 is formed at the upper end opening of the valve hole 22 . An inlet port 26 is provided at the side of the second body 8 and an outlet port 28 is provided at the bottom. A valve chamber 30 is formed inside the first body 6 and the second body 8 . The inlet port 26 and the outlet port 28 communicate through the valve chamber 30 .

An operating rod 32 extending from a rotor 60 of the motor unit 3 is inserted inside the body 5 . The operating rod 32 passes through the valve chamber 30 . The operating rod 32 is obtained by cutting a bar made of non-magnetic metal, and a needle-shaped valve element 34 is integrally provided in the lower part thereof. The valve portion is opened and closed by attaching and detaching the valve element 34 to and from the valve seat 24 from the valve chamber 30 side.

A guide member 36 is erected at the center of the upper portion of the first body 6 . The guide member 36 is obtained by cutting a tubular member made of a non-magnetic metal into a stepped cylindrical shape, and has a male thread 38 formed on the outer peripheral surface of the central portion in the axial direction. The lower end portion of the guide member 36 has a large diameter, and the large diameter portion 40 is press-fitted into the upper center of the first body 6 and fixed coaxially. The guide member 36 slidably supports the operating rod 32 in the axial direction with its inner peripheral surface, and slidably supports the rotating shaft 62 of the rotor 60 with its outer peripheral surface.

A spring receiver 42 is provided on the operating rod 32 slightly above the valve body 34 , and a spring receiver 44 is also provided on the bottom of the guide member 36 . A spring 46 (functioning as a "biasing member") is interposed between the spring bearings 42 and 44 to bias the valve body 34 in the valve closing direction.

On the other hand, the motor unit 3 is configured as a three-phase stepping motor including a rotor 60 and a stator 64. As shown in FIG. The motor unit 3 has a cylindrical can 66 with a bottom, the rotor 60 is arranged inside the can 66, and the stator 64 is arranged outside. The can 66 is a bottomed cylindrical member that covers the space in which the valve body 34 and its drive mechanism are arranged and that encloses the rotor 60. The can 66 acts as an inner pressure space (internal space) where the pressure of the refrigerant acts. and an outer non-pressure space (external space).

The can 66 is made of a non-magnetic metal (SUS in this embodiment), and is coaxially attached to the upper end of the first body 6 so that its lower portion is externally inserted. The amount of insertion of the can 66 is restricted by locking the lower end of the can 66 with the locking portion 52 . The body 5 and the can 66 are fixed and sealed by all-around welding (not shown) along the boundary between the lower end of the can 66 and the first body 6 . A space surrounded by the body 5 and the can 66 forms the pressure space.

The stator 64 is configured by arranging a plurality of salient poles at regular intervals on the inner peripheral portion of the laminated core 70 . The laminated core 70 is configured by laminating annular cores in the axial direction. A bobbin 74 with a coil 73 (electromagnetic coil) is attached to each salient pole. These coils 73 and bobbins 74 constitute a "coil unit 75". In this embodiment, three motor units 75 for supplying three-phase current are provided at intervals of 120 degrees with respect to the central axis of the laminated core 70 (details will be described later).

The stator 64 is provided integrally with the case 76 of the motor unit 3 . That is, the case 76 is obtained by injection molding (also referred to as “insert molding” or “molding”) of a corrosion-resistant resin material. The stator 64 is covered with molding resin obtained by injection molding. The case 76 is made of the mold resin. Hereinafter, the molded product of the stator 64 and the case 76 will also be referred to as a "stator unit 78".

The stator unit 78 has a hollow structure and is attached to the body 5 while coaxially passing through the can 66 . A seal accommodating portion 80 consisting of an annular groove is formed on the outer peripheral surface slightly below the locking portion 52 of the first body 6, and a seal ring 82 (O-ring) is fitted. A seal ring 82 is interposed between the upper outer peripheral surface of the first body 6 and the lower inner peripheral surface of the case 76 to prevent the outside atmosphere (such as water) from entering the gap between the can 66 and the stator 64. is prevented.

Rotor 60 includes a cylindrical rotor core 102 assembled to rotating shaft 62 , rotor magnets 104 provided on the outer peripheral surface of rotor core 102 , and sensor magnets 106 provided on the upper end surface of rotor core 102 . The rotor core 102 is attached to the rotating shaft 62 . The rotor magnet 104 is magnetized (magnetized) with a plurality of poles in its circumferential direction. The sensor magnet 106 is also magnetized (magnetized) with multiple poles. The rotor magnet 104 and the sensor magnet 106 are obtained by magnetizing a magnet portion integrally molded with the rotor core 102 in a post-process, the details of which will be described later.

The rotary shaft 62 is a cylindrical shaft with a bottom, and is fitted around the guide member 36 with its open end facing downward. A female thread 108 is formed on the lower inner peripheral surface of the rotating shaft 62 and meshes with the male thread 38 of the guide member 36 . Rotational motion of the rotor 60 is converted into axial motion of the operating rod 32 by the screw feed mechanism 109 using these threaded portions. As a result, the valve body 34 is moved (lifted/lowered) in the axial direction, that is, in the opening/closing direction of the valve portion.

The diameter of the upper portion of the operating rod 32 is reduced, and the reduced diameter portion 110 penetrates the bottom portion 112 of the rotating shaft 62 . An annular stopper 114 is fixed to the distal end of the reduced diameter portion 110 . On the other hand, a spring 116 is interposed between the base end of the diameter-reduced portion 110 and the bottom portion 112 to urge the operating rod 32 downward (that is, in the valve closing direction). With such a configuration, when the valve is opened, the operating rod 32 is displaced integrally with the rotor 60 in such a manner that the stopper 114 is locked to the bottom portion 112 . On the other hand, when the valve is closed, the spring 116 is compressed by the reaction force that the valve element 34 receives from the valve seat 24 . The valve element 34 can be pressed against the valve seat 24 by the elastic reaction force of the spring 116 at this time, and the seating performance (valve closing performance) of the valve element 34 can be enhanced.

The motor unit 3 has a circuit board 118 outside the can 66 . The circuit board 118 is fixed inside the case 76 . In this embodiment, various circuits functioning as a control section and a communication section are mounted on the lower surface of the circuit board 118 . Specifically, a drive circuit for driving the motor, a control circuit (microcomputer) that outputs control signals to the drive circuit, a communication circuit for the control circuit to communicate with an external device, each circuit and motor (coil) A power supply circuit and the like for supplying power are mounted. The upper end of the case 76 is closed with a lid 77 . A circuit board 118 is arranged in the space below the lid 77 in the case 76 .

A magnetic sensor 119 is provided on the surface of the circuit board 118 facing the sensor magnet 106 . The magnetic sensor 119 axially faces the sensor magnet 106 through the bottom end wall of the can 66 . The magnetic flux generated by the sensor magnet 106 changes as the rotor 60 rotates. The magnetic sensor 119 detects the amount of displacement of the rotor 60 (in this embodiment, the rotation angle of the rotor 60) by capturing this change in magnetic flux. Based on the displacement of the rotor 60, the control unit calculates the axial position of the valve body 34 and thus the valve opening degree.

A pair of terminals 117 connected to the coil 73 extends from each bobbin 74 and is connected to a circuit board 118 . A power supply terminal, a ground terminal, and a communication terminal (also collectively referred to as “connection terminals 81”) extend from the circuit board 118 and pass through the side wall of the case 76 to be drawn to the outside. A connector portion 79 is provided integrally with the side portion of the case 76 , and connection terminals 81 are arranged inside the connector portion 79 .

A stopper 90 is formed below the rotor 60 . As shown in Patent Document 2, the structure of the stopper 90 is known. When the operating rod 32 reaches the valve closing position, the spring 116 applies an elastic reaction force to the rotor 60 to keep the valve closed stably. Ultimately, the stopper 90 comes into contact with a projection (locking portion) (not shown) formed as a part of the guide member 36, thereby completely restricting the rotation of the rotor 60 in the valve closing direction. Hereinafter, the step when the stopper 90 comes into contact with the protrusion is referred to as the "origin" of the step. Further, in this embodiment, the valve body 34 is assumed to be at the "reference position" at the origin of the step.

FIG. 2 is a diagram showing the configuration of the stator 64 and its surroundings. FIG. 2A is a cross-sectional view of the stator unit 78 corresponding to the cross-section taken along line AA of FIG. FIG. 2B is a diagram showing only the stator 64 (state before resin molding). For reference, FIG. 2A shows the can 66 and the rotor 60 (see two-dot chain lines).

Since the motor unit 3 is a three-phase motor, the coil units 75 are provided at equal intervals around the axis L of the rotor 60 as shown in FIG. 2(A). As shown in FIG. 2B, slots 120a to 120c (collectively referred to as "slots 120" when not distinguished) are formed in the inner peripheral portion of the laminated core 70 at intervals of 120 degrees with respect to the axis L. is provided. In each slot 120, salient poles 122a to 122c (generically referred to as "salient poles 122") projecting radially inward from the center thereof are formed. (collectively referred to as "coil 73") are assembled. A slit 124 having a U-shaped cross section is also formed between the slots 120 adjacent to each other to optimize the magnetic path.

The rotor magnet 104 faces the salient poles 122a to 122c via the can 66. As shown in FIG. In this embodiment, as shown in FIG. 2(A), the rotor magnet 104 is magnetized with 10 male-threaded poles, but the number of poles can be set appropriately.

Next, the configuration of the magnets in rotor 60 will be described in detail.
FIG. 3 is a diagram showing the configuration of the rotor 60. As shown in FIG. 3(A) is a perspective view, FIG. 3(B) is a front view, FIG. 3(C) is a plan view, and FIG. 3(D) is a cross-sectional view taken along line BB of FIG. 3(C). "N" in the figure indicates an N pole, and "S" indicates an S pole. For convenience of explanation, the illustration of the rotating shaft 62 (see FIG. 1) is omitted in FIG.

The rotor 60 has a rotor magnet 104 along the outer peripheral surface of the rotor core 102 and a sensor magnet 106 at the axial end of the rotor core 102 (FIGS. 3A and 3D). The rotor magnet 104 has a cylindrical shape and is magnetized with 10 poles on its outer peripheral surface (FIGS. 3(B) and 3(C)). On the other hand, the sensor magnet 106 has an annular shape and is magnetized with planar two poles.

As shown in FIG. 3D, the inner peripheral surface of the rotor magnet 104 is fitted in the annular groove 140, and the lower surface of the sensor magnet 106 is fitted in the annular groove 144. As shown in FIG. That is, the annular groove 140 functions as a drop-off prevention structure that prevents the rotor magnet 104 from dropping off from the rotor core 102 . Similarly, annular groove 144 functions as a drop-off prevention structure that prevents drop-off of sensor magnet 106 from rotor core 102 .

Based on the above configuration, a method for detecting the rotation angle of the rotor 60 by the magnetic sensor 119 will now be described. In addition, below, the up-down direction of FIG. 1 is called "opening-and-closing direction" or "up-down direction."

FIG. 4 is a schematic diagram showing the relationship between the magnetic sensor 119, the sensor magnet 106, and the lines of magnetic force generated from the sensor magnet 106. As shown in FIG.
FIG. 4 is a schematic diagram of the magnetic sensor 119 and the sensor magnet 106 viewed from the side. As shown in FIG. 4, magnetic lines of force are generated from N to S of the sensor magnet 106 (permanent magnet). A magnetic sensor 119 positioned directly above the sensor magnet 106 is a known rotary sensor that detects magnetic lines of force generated from the sensor magnet 106 . The magnetic sensor 119 detects the rotation angle of the sensor magnet 106 (rotor 60) based on the direction of the magnetic lines of force (details will be described later). In the present embodiment, the magnetic sensor 119 can detect the rotation angle of the sensor magnet 106. The magnetic sensor 119 directly detects the distance to the sensor magnet 106, in other words, the amount of movement of the operating rod 32 in the opening/closing direction. It is assumed that it cannot be detected.

FIG. 5 is a plan view of the sensor magnet 106. FIG.
Rotational driving force is applied to the rotor 60 by applying a driving current to the coils 73 of the stator 64 by a method described later. When the rotor 60 is rotated in the valve closing direction (downward direction) (hereinafter referred to as “downward rotation”), the operating rod 32 (valve element 34) moves in the valve closing direction, that is, in the drawing of FIG. Move down. When the rotor 60 is rotated in the valve-opening direction (hereinafter referred to as "upward rotation"), the operating rod 32 (valve body 34) moves in the valve-opening direction, that is, upward in FIG. .

As the rotor 60 rotates, the sensor magnet 106 also rotates. As the sensor magnet 106 rotates, the magnetic field direction MA of the sensor magnet 106 also changes. When the XY coordinate system (corresponding to the horizontal plane in FIG. 1) is set as shown in FIG. 5, the angle formed by the magnetic field direction MA with the X axis is assumed to be θ. The magnetic sensor 119 detects the rotation angle θ of the sensor magnet 106 by a known method shown in the angle sensor of Patent Document 1.

FIG. 6 is a graph showing the relationship between the sensor value of the sensor magnet 106 and the sensing angle.
The horizontal axis indicates the rotation angle θ of the sensor magnet 106 to be measured by the magnetic sensor 119 (hereinafter sometimes referred to as "sensing angle"). The vertical axis is the sensor value of the magnetic sensor 119 . The sensor values in this example are arctangent values. As shown in FIG. 6, the magnetic sensor 119 detects a sensor value showing a sawtooth waveform corresponding to the sensing angle. The magnetic sensor 119 replaces the sensor value, which is an analog signal, with a pulse duty ratio by PWM (Pulse Width Modulation), and outputs a current indicating a modulated digital signal. At this time, the duty ratio of the pulse is determined by normalizing the sensor value from "lower limit value DA to upper limit value TA". The lower limit value DA and the upper limit value TA can be set arbitrarily. The lower limit value DA may be zero. Hereinafter, the pulse duty ratio may be referred to as an "angle value". The control circuit can identify the actual rotor angle (perceived angle) based on the duty ratio (angle value) read from the pulse of the digital signal according to the specifications of the magnetic sensor 119 .

FIG. 7 is a graph showing the relationship between the angle value (duty ratio) and step.
In this embodiment, when moving the valve body 34 from the highest point to the lowest point, the rotor 60 rotates four times in total. Although details will be described later, the control circuit rotates the rotor 60 by changing the magnetic field direction of each coil 73 by changing the drive current supplied to the three-phase coils 73 . In this embodiment, the control circuit rotates the rotor 60 in units of u1 degrees (details will be described later). Hereinafter, this unit rotation amount will be referred to as a "step". From 360 degrees×4 rotations÷u1 degrees=1440/u1=SM4, the control circuit instructs the rotor 60 to rotate a total of 4 steps of SM within the operating range of the operating rod 32 . The angle value changes four times between DA and TA corresponding to four rotations of the rotor 60 .

Step 0 corresponds to the origin, and step n represents the nth step counted from the origin. In the following description, step n may also be referred to as valve position Pos(n). SM1 shown in the figure represents the order of steps when the mechanical angle makes one revolution, SM2 represents the order of steps when the mechanical angle makes two revolutions, and SM3 represents the order of steps when the mechanical angle makes three revolutions. , and SM4 represents the order of steps when the mechanical angle rotates four times. A mechanical angle refers to an angle in real space of a rotating body such as the rotor 60 .

The control circuit supplies a predetermined level of drive current to the U-phase coil 73a. At this time, a drive current of a predetermined level is similarly applied to V-phase coil 73b and W-phase coil 73c. By applying a drive current to each coil 73, the magnetic field in the coil 73 is changed and the rotor 60 is rotated. A combination of current values of drive currents to be applied to each of U-phase coil 73a, V-phase coil 73b and W-phase coil 73c is called an "excitation pattern". There are N types of excitation patterns in this embodiment. Changing a certain excitation pattern P1 to an adjacent excitation pattern P2 corresponds to "one step" of rotation, in other words, a rotation instruction for a unit rotation amount.

By changing the excitation pattern, in other words, by changing the excitation pattern step by step, the indicated angle α (ideal rotor angle) is controlled. The rotor 60 rotates in synchronization with the change in the indicated angle α, and the sensing angle θ also changes. After changing the excitation pattern, by calculating the sensing angle θ from the angle value detected by the magnetic sensor 119, the control circuit can detect a state in which the sensing angle θ (actual rotor angle) follows the indicated angle α. It is determined whether or not. The state in which the sensing angle .theta.

A pattern ID is assigned to each of the N types of excitation patterns. IU(N1), IV (N1) and IW(N1). That is, the excitation pattern (N1) means a combination of [IU(N1), IV(N1), IW(N1)]. Drive currents IU(N1), IV(N1) and IW(N1) generate a magnetic field in each coil 73 to guide the rotor 60 to an indicated angle α corresponding to the excitation pattern (N1).

The N types of pattern IDs correspond to N steps for one round of the electrical angle. The electrical angle is a theoretical value obtained by evenly assigning N pattern IDs in the range of 0 to 360 degrees. Each step n from the origin to the top is cyclically associated with the pattern ID in sequence. For example, the pattern ID is defined as the remainder of n divided by N. A continuous pattern ID corresponds to an excitation pattern that changes continuously.

When the control circuit moves from step n to step n+1, it switches from excitation pattern (N1) to excitation pattern (N1+1). As a result, the magnetic field generated by each coil 73 is changed with the drive current values [IU(N1+1), IV(N1+1), IW(N1+1)], and the rotor 60 is rotated upward by the unit rotation amount. Conversely, when the control circuit moves from step n to step n-1, it switches from excitation pattern (N1) to excitation pattern (N1-1). As a result, the magnetic field generated by each coil 73 is changed by the drive current values [IU(N1-1), IV(N1-1), IW(N1-1)], and the rotor 60 is rotated downward by the unit rotation amount.

In the case of the rotor 60 having the structure shown in FIG. 3, since the rotor magnet 104 has five pairs of N and S poles, the rotor 60 rotates five times in one revolution (360 mechanical degrees). That is, one round of the electrical angle corresponds to 72 degrees of the mechanical angle. Also, since one revolution of the electrical angle includes N steps, the mechanical angle rotated by one step change is u1=72/N degrees. Further, as described with reference to FIG. 7, when the rotor 60 is rotated four times while the valve body 34 is moved from the highest point to the origin, 4.times.5.times.N steps are advanced in the movement over the entire area. become. That is, SM4 shown in FIG. 7 is 4×5×N. Similarly, SM1 is 5*N, SM2 is 2*5*N, and SM3 is 3*5*N.

In this embodiment, the position of the rotor 60 when the stopper 90 contacts the guide member 36 (more precisely, the projection of the guide member 36) is defined as the origin (reference position), and the control circuit controls the angle value and The excitation pattern is recorded as "origin information (reference information)". When the motor-operated valve 1 is manufactured, origin information (reference information) unique to the motor-operated valve 1 is recorded in the non-volatile memory of the circuit board 118 . Then, the control circuit adjusts the amount of movement of the operating rod 32, that is, the valve opening degree of the motor-operated valve 1, by step n based on the origin (valve closed position).

FIG. 8 is a schematic diagram of the movement range of the rotor 60. As shown in FIG.
The right direction in FIG. 8 indicates the opening direction (upward direction) of the rotor 60, and the left direction indicates the closing direction (downward direction). The origin of step 0 is the limit position where the stopper 90 is restricted in rotation and the rotor 60 cannot rotate downward any more. Step M is the valve opening point at which the rotor 60 rotates upward. The value of M may be a predetermined common value, or may be a peculiar value different for each motor operated valve 1 . When the eigenvalue is used, the value of M indicating the valve opening step is stored in the non-volatile memory of the circuit board 118 . In the range from the origin to the valve opening point, the valve body 34 is pressed against the valve seat 24 by the elastic reaction force of the spring 116, so the valve closed state is maintained. When the rotor 60 continues to rotate upward from the origin 0 and exceeds the valve opening point M, the valve body 34 separates from the valve seat 24 and the valve is opened. When the upward rotation of the rotor 60 continues even after the valve opening point is exceeded, the valve opening degree gradually increases, and the flow rate from the inlet port 26 to the outlet port 28 increases.

In both the valve closed state from the origin to the valve opening point and the valve open state from the valve opening point to the highest point, load torque is generated during sliding due to frictional resistance in the screw feed mechanism 109 . In particular, when the valve is closed, the pressure on the contact surface between the female thread 108 and the male thread 38 is increased and the frictional resistance is increased, so the load torque is greater than when the valve is open. Therefore, the motor-operated valve 1 has a mechanical characteristic that the drive torque required to rotate the rotor 60 is greater in the valve closed state than in the valve open state. That is, when the valve is closed, it is more difficult to slide than when the valve is open, so it can be said that the indicated angle α (ideal rotor angle) and the sensed angle θ (actual rotor angle) are likely to deviate.

In this embodiment, step-out is detected in the control circuit. Specifically, when the difference (hereinafter referred to as "mechanical angle difference") between the indicated angle α (ideal rotor angle) and the sensed angle θ (actual rotor angle) exceeds a predetermined threshold, the judged to have been adjusted. Strictly speaking, when the mechanical angle difference exceeds the threshold value, it is not necessarily the case that a step-out phenomenon has actually occurred, but it is determined as a step-out in the sense that the stable tuning state is lost. Note that the mechanical angle difference is sometimes called "load angle".

In this example, step-out detection is performed when permission is set from an external device through LIN (Local Interconnect Network) communication. In addition, step-out during valve movement and when the valve is stopped during use is detected, but step-out during calibration is not detected. The rotor angle RA_m(0) at the step 0 position (origin position) stored in a non-volatile memory (for example, NVRAM (Non-Volatile RAM)) is used as a reference. This reference refers to the origin detected during manufacture. RA_m(0) is the eigenvalue of the motor operated valve 1; In other words, the rotor angle RA_m(0) at the origin is different for each individual.

Assuming that n steps have progressed from the origin, the valve position is identified by step n. In the following, step n will be referred to as valve position and may be expressed as Pos(n).

The indicated angle α (ideal rotor angle) described above is a target angle of the rotor 60 determined over time according to a command from an external device. Below, the indicated angle α is expressed as an ideal rotor angle: RA_c(n). For example, when guiding the valve body 34 to the origin, the ideal rotor angle RA_c(0) is the rotor angle RA_m(0) at the origin position.

As the step n (=valve position Pos(n)) is increased, the posture of the rotor 60 changes. The angle through which the rotor 60 rotates is proportional to the value of n (=Pos(n)). Denoting the mechanical angle/step ratio by a given value R, the relative increment angle is (Pos(n)*R). Therefore, the cumulative rotor 60 angle relative to the origin is (Pos(n)*R)+RA_m(0). Here, the ideal rotor angle RA_c(n) is obtained by Equation (1) when expressed in terms of an angle (0 to 360 degrees) that indicates the attitude, taking into account that the rotor 60 rotates more than once.
RA_c(n)=((Pos(n)×R)+RA_m(0)) mod 360 [Formula 1]

FIG. 9 is a graph showing the relationship between the step and the ideal rotor angle.
The one-dot chain line shown in the figure indicates that the step SM4, which is the highest point, is reached when the rotor 60 makes four revolutions and the rotor angle cumulatively changes by 1440 degrees. Also, the gradient of the dash-dotted line represents the mechanical angle/step ratio R (for example, u1 degrees).

The illustrated solid line indicates the relationship between the step and the ideal rotor angle in the motor operated valve 1 where the rotor angle RA_m(0) at the origin position is 180 degrees. As described above, the ideal rotor angle RA_c(n) falls within the range of 0 to 360 degrees, which indicates the orientation of the rotor 60 . The white circle on the solid line indicates that the ideal rotor angle RA_c (0.83×SM1) at the step (0.83×SM1) is 120 degrees calculated by ((0.83×SM1×u1)+180) mod 360 It shows that

The illustrated dashed line indicates the relationship between the step and the ideal rotor angle in the motor operated valve 1 where the rotor angle RA_m(0) at the origin position is 270 degrees. The white circle on the dashed line indicates that the ideal rotor angle RA_c (1.67×SM1) at step (1.67×SM1) is 150 degrees calculated by ((1.67×SM1×u1)+270) mod 360 It shows that

Thus, the relationship between step n (=valve position Pos(n)) and ideal rotor angle RA_c(n) is determined by geometric theory. On the other hand, the relationship between the step n (=valve position Pos(n)) and the sensing angle θ (actual rotor angle) cannot be determined only by geometric theory. This is because the actual rotor angle is determined by the dynamic balance between the load torque during sliding and the drive torque applied to the rotor 60 . The ideal rotor angle is the angle of the rotor 60 that is geometrically generated when the motor unit 3 is stabilized by excitation. It is the angle of the rotor 60 in the assumed case. On the other hand, the actual rotor angle is the angle of the rotor 60 when the load torque actually generated during sliding and the driving torque of the motor unit 3 are balanced. In the following, the actual rotor angle appearing as the sensed angle θ is represented as RA_m(n).

FIG. 10 is a graph showing changes in drive torque.
The driving torque of the motor unit 3 is determined by the electrical angle indicated by the excitation pattern (hereinafter referred to as the “ideal electrical angle”) and the electrical angle corresponding to the actual attitude of the rotor 60 (hereinafter referred to as the “actual electrical angle”). ) is determined by the difference between This electrical angle difference is defined as the ideal electrical angle minus the actual electrical angle. The drive torque can be calculated as a sine value with the electrical angle difference as a variable. Therefore, a sine curve is drawn as shown. In this figure, the drive torque is shown with a ratio of 1 to the maximum drive torque.

The electrical angle difference is proportional to the difference between the step corresponding to the excitation pattern (hereinafter referred to as the "ideal step") and the step corresponding to the actual attitude of the rotor 60 (hereinafter referred to as the "actual step"). in a relationship. This step difference is defined as ideal step minus actual step. Therefore, the magnitude relationship between the electrical angle difference in a certain state A and the electrical angle difference in another state B matches the magnitude relationship between the step difference in the state A and the step difference in the state B. FIG.

Furthermore, the electrical angle difference is proportional to the mechanical angle difference between the ideal rotor angle and the actual rotor angle corresponding to the electrical angle indicated by the excitation pattern. This mechanical angle difference is defined as the ideal rotor angle minus the actual rotor angle. Therefore, the magnitude relationship between the electrical angle difference in state A and the electrical angle difference in another state B matches the magnitude relationship between the mechanical angle difference in state A and the mechanical angle difference in state B. FIG.

A description will be given of how the drive torque changes as the electrical angle difference increases. When the electrical angle difference is 0, no driving torque is generated. As the electrical angle difference increases, the driving torque increases. The driving torque becomes maximum when the electrical angle difference is 90 degrees. As the electrical angle difference further increases, the driving torque begins to decrease. If the drive torque falls below the load torque while the drive torque is decreasing, it is considered that a step-out phenomenon actually occurs.

Therefore, if the step n is changed to rotate upward, the rotor 60 will not rotate until the drive torque exceeds the load torque. When the drive torque exceeds the load torque, rotor 60 begins to rotate. After that, the actual rotor angle follows the ideal rotor angle while the electrical angle difference remains. As long as the electrical angle difference does not increase and the driving torque does not fall below the load torque as described above, follow-up continues.

When stopping the rotor 60, the step n is not changed. As a result, the actual electrical angle approaches the ideal electrical angle and the electrical angle difference is reduced. However, as the electrical angle difference becomes smaller, the driving torque becomes smaller, so the approach does not occur until the electrical angle difference becomes zero. The rotor 60 stops when the drive torque is balanced with the load torque.

When the electrical angle difference is a negative value, the direction of the driving torque is reversed and a similar change is shown. The rotor 60 also exhibits a similar behavior with its direction reversed. Note that the tuning range of each illustrated scene will be described later.

In this embodiment, out-of-step detection is performed in consideration of the behavior described above. Specifically, when the mechanical angle difference between the actual rotor angle and the ideal rotor angle exceeds a reference value, it is determined that the rotor has stepped out. From another point of view, it may be considered that step-out is determined when the electrical angle difference between the actual electrical angle and the ideal electrical angle exceeds a reference value. Alternatively, if the step difference between the actual step and the ideal step exceeds a reference value, it may be considered that the step-out is determined. Determination using either type of difference is theoretically synonymous.

In this embodiment, different reference values are used when the valve is moving and when the valve is stopped. "Valve movement" as used herein means a state in which steps are switched to change the excitation pattern. If the valve is open, the valve literally moves, but if the valve is closed, the valve does not move even if the step is changed. However, if the step is switched even when the closed valve does not move, it is regarded as during the valve movement here. Further, the term "valve stop" used herein means a state in which a constant excitation pattern is maintained without switching steps. Furthermore, the reference value is also distinguished between the valve closed state and the valve open state. In the following, the reference values corresponding to each scene will be described assuming a scene combining the valve moving state and the valve stopped state, and the valve closed state and the valve open state.

FIG. 11 is a diagram showing the reference value of the step difference and the reference value of the mechanical angle difference in each scene.
Scene (a) during valve movement at step n greater than the valve opening point, scene (b) during valve stop at step n greater than the valve opening point, and valve movement at step n below the valve opening point. and scene (d) when the valve is stopped at step n below the valve opening point. In scenes (a) and (b), a small load torque is generated with the valve open. In scenes (c) and (d), a large load torque is generated when the valve is closed.

Here, the upper limit number and the lower limit number of the step difference are shown as examples of the reference value of the step difference. The range from the lower limit number to the upper limit number of the step difference is called the tuning range of the step difference. The step difference tuning range represents the step difference at stable tuning conditions. The tuning range of the step difference is an example of a reference range that serves as a reference for determining out-of-step.

Also, the upper limit and the lower limit of the mechanical angle difference are shown as an example of the reference value of the mechanical angle difference. The range from the lower limit to the upper limit of the mechanical angle difference is called the tuning range of the mechanical angle difference. The mechanical angle difference tuning range also represents the mechanical angle difference in a stable tuning state.

If the step difference is out of the tuning range, that is, if the mechanical angle difference is out of the tuning range, it is considered as out-of-step. Even if it is out of the tuning range, it does not necessarily mean that the phenomenon of step-out actually occurs, but at least it can be said that the risk of step-out is high. Therefore, the step-out detected in this example can be regarded as a kind of abnormality or a kind of caution or warning.

In scene (a), the upper limit number of step differences is Ua, and the lower limit number is La. FIG. 10 shows an example of the upper limit number Ua and the lower limit number La. In this example, the upper limit number Ua corresponds to the electrical angle difference of 90 degrees. The lower limit number La corresponds to the electrical angle difference of -90 degrees. That is, during the valve movement in the valve open state, it is determined that there is no step-out until the absolute value of the driving torque reaches the maximum value. Note that the upper limit number Ua corresponds to the upper limit ua of the mechanical angle difference, as shown in the figure. In this example, the upper limit ua of the mechanical angle difference is 72/4=18 degrees. Also, the lower limit number La corresponds to the lower limit la of the mechanical angle difference. In this example, the upper limit la of the mechanical angle difference is -18 degrees.

In the scene (b), the upper limit number of step differences is Ub, and the lower limit number is Lb. FIG. 10 shows an example of the upper limit number Ub and the lower limit number Lb. In this example, the upper limit number Ub corresponds to an electrical angle difference of 45 degrees. The lower limit number Lb corresponds to the electrical angle difference of -45 degrees. That is, if the absolute value of the drive torque does not exceed the maximum value×sin45 when the valve is stopped while the valve is open, it is determined that there is no step-out. Note that the upper limit number Ub corresponds to the upper limit ub of the mechanical angle difference, as shown in the figure. In this example, the upper limit ub of the mechanical angle difference is 72/8=9 degrees. Also, the lower limit number Lb corresponds to the lower limit lb of the mechanical angle difference. In this example, the lower limit lb of the mechanical angle difference is -9 degrees.

In scene (c), the upper limit number of step differences is Uc, and the lower limit number is Lc. FIG. 10 shows an example of the upper limit number Uc and the lower limit number Lc. In this example, the upper limit number Uc corresponds to an electrical angle difference of 97.5 degrees. The lower limit number Lc corresponds to an electrical angle difference of −97.5 degrees. That is, when the valve is moving in the closed state, if the absolute value of the drive torque exceeds the maximum value and does not fall below the maximum value×sin 97.5, it is determined that there is no step-out. As shown in the figure, the upper limit number Uc corresponds to the upper limit uc of the mechanical angle difference. Also, the lower limit number Lc corresponds to the lower limit lc of the mechanical angle difference.

In scene (d), the upper limit number of step differences is Ud, and the lower limit number is Ld. FIG. 10 shows an example of the upper limit number Ud and the lower limit number Ld. In this example, the upper limit number Ud corresponds to an electrical angle difference of 60 degrees. The lower limit number Ld corresponds to the electrical angle difference of -60 degrees. In other words, when the valve is closed and the valve is stopped, it is determined that there is no step-out unless the absolute value of the driving torque exceeds the maximum value×sin60. As shown in the figure, the upper limit number Ud corresponds to the upper limit ud of the mechanical angle difference. Also, the lower limit number Ld corresponds to the lower limit ld of the mechanical angle difference.

In this example, for each upper limit number, the magnitude relationship is Uc>Ua>Ud>Ub. Similarly, for each lower limit number, the magnitude relationship is Lc<La<Ld<Lb.

The reason why Uc (valve closed state) > Ua (valve open state) for the upper limit number during valve movement and Lc (valve closed state) < La (valve open state) for the lower limit number during valve movement is because the valve is closed state This is because the load torque increases and the step difference tends to widen during movement. The reason why Ud (valve closed state) > Ub (valve open state) for the upper limit number when the valve is stopped and Ld (valve closed state) < Lb (valve open state) for the lower limit number when the valve is stopped is as follows. This is because when the valve is closed, the load torque is large, so the driving torque balanced with this is also large, and the step difference is not completely reduced, and the vehicle stops.

In a specific process, based on these upper limit numbers Ua, Ub, Uc and Ud and lower limit numbers La, Lb, Lc and Ld, the actual rotor angle tuning range in each scene is assumed. The actual rotor angle tuning range is specified by the maximum and minimum angles. If the actual rotor angle deviates from this tuning range, it is determined that the rotor has stepped out.

Scene (a): When the valve is moving at a step n greater than the valve opening, the maximum angle RA_max(n) of the tuning range is given by Equation 2 or Equation 3 below.
RA_max(n)=RA_c(n+Ua) [Formula 2]
RA_c(n+Ua): Ideal rotor angle RA_max(n) at step (n+Ua)=(RA_c(n)+Ua×R) mod 360 [Formula 3]
RA_c(n): ideal rotor angle at step n R: mechanical angle/step ratio

Further, in the case of scene (a), the minimum angle RA_min(n) of the tuning range is obtained by Equation 4 or Equation 5 below.
RA_min(n)=RA_c(n+La) [Formula 4]
RA_c(n+La): Ideal rotor angle RA_min(n) at step (n+La)=(RA_c(n)+La×R) mod 360 [Formula 5]

Scene (b): When the valve is stopped at a step n larger than the valve opening point, the maximum angle RA_max(n) of the tuning range is obtained by Equation 6 or Equation 7 below.
RA_max(n)=RA_c(n+Ub) [Formula 6]
RA_c(n+Ub): Ideal rotor angle RA_max(n) at step (n+Ub)=(RA_c(n)+Ub×R) mod 360 [Formula 7]

Also, in the case of scene (b), the minimum angle RA_min(n) of the tuning range is obtained by Equation 8 or Equation 9 below.
RA_min(n)=RA_c(n+Lb) [Formula 8]
RA_c(n+Lb): Ideal rotor angle RA_min(n) at step (n+Lb)=(RA_c(n)+Lb×R) mod 360 [Formula 9]

Scene (c): When the valve is moving at step n below the valve opening point, the maximum angle RA_max(n) of the tuning range is obtained by Equation 10 or Equation 11 below.
RA_max(n)=RA_c(n+Uc) [Formula 10]
RA_c(n+Uc): ideal rotor angle RA_max(n) at step (n+Uc)=(RA_c(n)+Uc×R) mod 360 [Equation 11]

Also, in the case of scene (c), the minimum angle RA_min(n) of the tuning range is obtained by Equation 12 or Equation 13 below.
RA_min(n)=RA_c(n+Lc) [Equation 12]
RA_c(n+Lc): Ideal rotor angle RA_min(n) at step (n+Lc)=(RA_c(n)+Lc×R) mod 360 [Equation 13]

Scene (d): When the valve is stopped at step n below the valve opening point, the maximum angle RA_max(n) of the tuning range is obtained by the following equation 14 or 15.
RA_max(n)=RA_c(n+Ud) [Formula 14]
RA_c(n+Ud): Ideal rotor angle RA_max(n) at step (n+Ud)=(RA_c(n)+Ud×R) mod 360 [Equation 15]

Also, in the case of scene (d), the minimum angle RA_min(n) of the tuning range is obtained by Equation 16 or Equation 17 below.
RA_min(n)=RA_c(n+Ld) [Equation 16]
RA_c(n+Ld): Ideal rotor angle RA_min(n) at step (n+Ld)=(RA_c(n)+Ld×R) mod 360 [Equation 17]

In any of the scenes (a) to (d), the maximum angle RA_max(n) and the minimum angle RA_min(n) are converted into duty ratios. A duty ratio SO_max(n) corresponding to the maximum angle is obtained by Equation (18). Also, the duty ratio SO_min(n) corresponding to the minimum angle is obtained by Equation (19).
SO_max(n)=constant S×RA_max(n)+constant T [Formula 18]
SO_min(n)=constant S×RA_min(n)+constant T [equation 19]
The constant S is the ratio of duty ratio/mechanical angle. The constant T is the lower limit value DA of the duty ratio.

FIG. 12 shows the truth table of logical operation Z. FIG.
In this embodiment, step-out is determined by logical operation Z using the duty ratios SO_max(n) and SO_min(n) described above. A logic operation Z (formula 23) is performed based on the success or failure of formula 20 representing relationship A, formula 21 representing relationship B, and formula 22 representing relationship C.
Relation A: SO_max(n)>SO_min(n) [Equation 20]
Relation B: SO_max(n)≧SO_m(n) [Formula 21]
Relation C: SO_m(n)≧SO_min(n) [Equation 22]
Logical operation Z: Relation A xor Relation B xor Relation C [Formula 23]

SO_m(n) is the duty ratio (angle value) read from the digital signal pulse received from the magnetic sensor 119 . The duty ratio SO_m(n) corresponds to the actual rotor angle RA_m(n). This correspondence relationship is illustrated in FIG.

If the result of the logical operation Z is true (1), it is determined that it is in sync, and if the result of the logical operation Z is false (0), it is determined that it is out of sync. There are six combinations of patterns 1 to 6 shown in the figure that are logically possible.

In this example, the magnitude relation is determined by the duty ratio for relation A to relation C, which matches the magnitude relation in the actual rotor angle.

FIG. 13 is a graph showing an example of determination of out-of-step and synchronization.
The left vertical axis indicates the rotor angle RA, and the right vertical axis indicates the duty ratio SO. The rotor angle RA and duty ratio SO are in a linear relationship. Therefore, they are mutually convertible. The horizontal axis indicates the step n (=valve position Pos(n).

The illustrated solid line indicates the maximum angle RA_max(n) of the tuning range and the duty ratio SO_max(n) corresponding to the maximum angle. Similarly, the dashed-dotted line indicates the ideal rotor angle RA_c(n) and the duty ratio SO_c(n) corresponding to the ideal rotor angle. Similarly, dashed lines indicate the minimum angle RA_min(n) of the tuning range and the duty ratio SO_min(n) corresponding to the minimum angle.

Black circles indicate out-of-step examples of patterns 1, 4 and 5. FIG. Tuning examples of patterns 2, 3 and 6 are indicated by white circles.
For example, for pattern 6, SO_max(n)>SO_min(n) and relationship A is true (1). SO_max(n)≧SO_m(n) and relation B is true (1). Also, SO_m(n)≧SO_min(n) and relation C is true (1). Therefore, the logical operation Z is true (1), and the determination result is tuning.

For example, for pattern 5, SO_max(n)>SO_min(n) and relation A is true (1), as shown. SO_max(n)≧SO_m(n) and relation B is true (1). Also, SO_m(n)<SO_min(n) and relationship C is false (0). Therefore, the logical operation Z is false (0), and the determination result is step-out.

In the section where step n is P1 to P2, the relationship A is false (0) because the magnitude relationship between SO_max(n) and SO_min(n) is reversed. Patterns 1 to 3 in this section have a different determination logic from patterns 4 to 6 in the section where relation A is true (1).

Next, the timing of determination will be described.
As for determination during valve movement, determination processing is executed immediately before switching to the next excitation every time the valve is moved by one step. The determination when the valve is stopped is performed once each time the valve is stopped. Specifically, the determination process is executed when a predetermined standby time has elapsed after the holding current stop process. The standby time may be based on the time until the three-phase coil current (probe) converges when the power line is open. For example, the length of time obtained by adding a predetermined extra time to the time until convergence may be used as the waiting time.

FIG. 14 is a functional block diagram of the electric valve control device 200. As shown in FIG.
Each component of the electric valve control device 200 includes hardware (control circuit) including a control circuit (microcomputer) on the circuit board 118, storage devices such as memory and storage, and wired or wireless communication lines connecting them. It is implemented by software that is stored in a storage device and that supplies processing instructions to the calculator. Computer programs may consist of device drivers and application programs, as well as libraries that provide common functionality to these programs. Each block described below represents a functional block rather than a hardware configuration.

The electric valve control device 200 includes a data processing section 202 , a communication section 204 , a reference information storage section 206 and a rotor interface section 208 .
The communication unit 204 functions as an interface with an external device via the connection terminal 81 . Rotor interface section 208 functions as an interface for magnetic sensor 119 and coil unit 75 . The reference information storage unit 206 stores origin information (reference information). A reference information storage unit 206 is a storage area configured in a nonvolatile memory. The data processing unit 202 executes various processes based on the reference information and various data acquired from the communication unit 204 and the rotor interface unit 208 . Data processing unit 202 also functions as an interface for communication unit 204 , rotor interface unit 208 and reference information storage unit 206 .

Communication unit 204 includes a receiving unit 210 that receives data and commands from an external device, and a transmitting unit 212 that transmits data to the external device.

Rotor interface portion 208 includes a rotation instructing portion 214 and a rotation detecting portion 216 . Rotation instruction unit 214 outputs a drive current to each of U-phase coil 73a, V-phase coil 73b, and W-phase coil 73c according to the excitation pattern. The rotation detector 216 reads the duty ratio (angle value) from the current pulse received from the magnetic sensor 119 .

The data processing section 202 includes a rotation control section 218 and a step-out detection section 220 . The rotation control section 218 controls the rotation instruction section 214 based on the origin information and the command received from the external device. The step-out detection unit 220 detects step-out by performing step-out determination processing in each scene.

15 and 16 are flow charts showing the main processing steps.
Rotation control unit 218 identifies step n (S10). Step n is determined based on the movement command (including the movement direction and movement speed) or the stop command received from the external device by the receiving unit 210 .

The step-out detection unit 220 determines whether step n has progressed (S12). In the case of movement in the valve opening direction, the rotation control unit 218 switches the excitation pattern to the upward rotation direction, so step n is increased by one. In the case of movement in the valve closing direction, the rotation control unit 218 switches the excitation pattern to the downward rotation direction, so the step n is decreased by one. Whether step n increases or decreases, it is determined that step n has progressed. The timing at which step n advances is determined by the rotation control unit 218 based on the moving speed.

When it is determined that step n has progressed (Y in S12), the step-out detection unit 220 determines whether or not step n is greater than the valve opening point (S14). If the step n is greater than the valve opening point (Y of S14), that is, if the valve is open, the step-out detection unit 220 executes the step-out determination process of scene (a) (S16). On the other hand, if step n is equal to or less than the valve opening point (N in S14), that is, if the valve is closed, the step-out detection unit 220 executes the step-out determination process of scene (c) (S18). . The step-out determination process for each scene will be described later with reference to FIG. After the step-out determination process, the rotation control unit 218 switches the excitation pattern instructed to the rotation instructing unit 214 (S20). The excitation pattern at this time corresponds to step n specified in S10. Then, the process returns to S10 and repeats the above-described processing.

It returns to description of the process of S12. If it is determined that step n has not progressed (N of S12), the process proceeds to S22 shown in FIG.

The rotation control unit 218 determines whether or not to stop energizing the rotation instructing unit 214 (S22). For example, when receiving unit 210 receives a stop command from an external device, rotation control unit 218 determines to stop energization of rotation instructing unit 214 .

When the rotation control unit 218 determines not to stop the energization (N of S22), the process returns to S10. On the other hand, when the rotation control unit 218 determines to stop the energization (Y of S22), the rotation control unit 218 turns off the energization of the rotation instructing unit 214 (S24).

When the movement command is issued again, it is necessary to restart the energization, so the rotation control section 218 determines whether or not to restart the energization of the rotation instructing section 214 (S26). If the receiving unit 210 has not received a movement command from the external device, the rotation control unit 218 determines not to resume energization of the rotation instructing unit 214 . If it is determined not to restart the energization (N of S26), the step-out detection unit 220 determines whether or not a predetermined waiting time has elapsed since the energization was turned off (S28). The predetermined standby time corresponds to, for example, the time required for the current to fall. That is, it waits until the three-phase coil current (probe) converges due to the opening of the power supply line.

If it is determined that the predetermined waiting time has not passed (N of S28), the rotation control section 218 returns to the process of S26. Then, if it is determined to restart the energization (Y of S26), the rotation control section 218 turns ON the energization of the rotation instructing section 214 (S30), and returns to the process of S10. In this way, when the energization is restarted immediately, the out-of-step determination process at the time of valve stop is not performed.

On the other hand, if it is determined that the predetermined standby time has elapsed without restarting the energization (Y in S28), the step-out detection unit 220 determines whether step n is greater than the valve opening point ( S32). If the step n is greater than the valve opening point (Y of S32), that is, if the valve is open, the step-out detection unit 220 executes the step-out determination process of scene (b) (S34). On the other hand, if step n is equal to or less than the valve opening point (N of S32), that is, if the valve is closed, the step-out detection unit 220 executes the step-out determination process of scene (d) (S36). .

After performing the out-of-step determination process, the system waits until the energization is resumed. That is, the rotation control unit 218 repeatedly determines whether or not to restart the energization of the rotation instructing unit 214 (S38). Power supply to the instruction unit 214 is turned on (S40), and the process returns to S10. That is, when the receiving unit 210 receives a movement command from the external device, the original processing is resumed.

FIG. 17 is a flow chart showing the step-out determination process for each scene.
First, the step-out detection unit 220 calculates the ideal rotor angle RA_c(n) by performing the calculation of Equation 1 described above (S50).

Next, the step-out detector 220 calculates the maximum angle RA_max(n) of the tuning range (S52). In the case of scene (a), the step-out detection unit 220 executes the processing of calculating the equation 3 described above. If it is the scene (b), the step-out detection unit 220 executes the processing of calculating the equation 7 described above. In the case of scene (c), the step-out detection unit 220 executes the processing of the above-described equation (11). If it is scene (d), the step-out detection unit 220 executes the processing of the above-described equation (15).

Furthermore, the step-out detector 220 calculates the minimum angle RA_min(n) of the tuning range (S54). In the case of scene (a), the step-out detection unit 220 executes the processing of calculating the equation 5 described above. If it is the scene (b), the step-out detection unit 220 executes the processing of calculating the equation 9 described above. In the case of scene (c), the step-out detection unit 220 executes the processing of the above-described equation (13). If it is scene (d), the step-out detection unit 220 executes the processing of calculating the equation 17 described above.

The step-out detector 220 calculates the duty ratio SO_max(n) corresponding to the maximum angle RA_max(n) (S56). The step-out detection unit 220 executes the processing of calculating Equation 18 described above.

The step-out detection unit 220 calculates the duty ratio SO_min(n) corresponding to the minimum angle RA_min(n) (S58). The step-out detection unit 220 executes the processing of calculating the equation (19) described above.

The rotation detector 216 reads the duty ratio SO_m(n) from the pulse received from the magnetic sensor 119 (S60).

Then, step-out detecting section 220 determines whether relation A (formula 20), relation B (formula 21), and relation C (formula 22) are true or false, and further determines the truth or falsehood of relation C (formula 22). Based on, the truth or falsehood of the logical operation Z (formula 23) is determined (S62). If the result of logical operation Z is true (1), it is determined that there is no step-out, and if it is false (0), it is determined that step-out has occurred.

When the step-out detection unit 220 determines that there is no step-out (N of S64), the process returns to the caller of the main process (S20 or S38).

On the other hand, if the step-out detection unit 220 determines that step-out has occurred (Y in S64), the transmission unit 212 transmits a step-out notification to the external device to notify that the step-out has occurred (S66). Then, the process returns to the caller (S20 or S38) of the main process.

It should be noted that the present invention is not limited to the above-described embodiments and modifications, and can be embodied by modifying the constituent elements without departing from the scope of the invention. Various inventions may be formed by appropriately combining a plurality of constituent elements disclosed in the above embodiments and modifications. Also, some constituent elements may be deleted from all the constituent elements shown in the above embodiments and modifications.

[Modification]
In this embodiment, an example in which the origin of the lowest point is used as the reference position has been described. As a modification, the highest point may be set as the reference position. The reference position may be a reference position for driving the operating rod 32 by the rotor 60 . The reference position can be arbitrarily determined as long as it is a position where the rotation of the rotor 60 can be restricted by the stopper 90 .

Equation 24 may be used instead of Equation 21 for relationship B described above.
Relation B: SO_max(n)>SO_m(n) [Formula 24]
Similarly, Equation 25 may be used instead of Equation 22 for relationship C.
Relationship C: SO_m(n)>SO_min(n) [Equation 25]

The read duty ratio (angle value) SO_m(n) may be converted into the actual rotor angle RA_m(n), and the logical operation Z may be performed based on the relationships A to C of the rotor angles. In that case, the relationship A is represented by Equation 26. Relationship B is represented by Equation 27 or Equation 28. Relationship C is represented by Equation 29 or Equation 30.
Relation A: RA_max(n)>RA_min(n) [Formula 26]
Relation B: RA_max(n)≧RA_m(n) [Formula 27]
Relation B: RA_max(n)>RA_m(n) [Formula 28]
Relation C: RA_m(n)≧RA_min(n) [Equation 29]
Relation C: RA_m(n)>RA_min(n) [Formula 30]

The determination process may be executed in synchronization with the PWM period of the magnetic sensor 119 . In other words, the determination process may be executed at the timing when the PWM pulse is received.

In the above embodiment, the example of executing the out-of-step determination process only once when the valve is stopped has been described, but as a modified example, the out-of-step determination process may be performed multiple times when the valve is stopped.

In the above-described embodiment, the configuration in which the magnetic sensor 119 faces the sensor magnet 106 in the axial direction is exemplified (see FIG. 1). In a modification, the magnetic sensor may be arranged laterally (outside in the radial direction) of the sensor magnet. That is, both may be opposed in the radial direction. The outer peripheral surface of the sensor magnet may be magnetized. The number of poles can be appropriately set, for example, two poles in the valve body.

In the above embodiment, the configuration in which the rotor magnet 104 and the sensor magnet 106 are separated in the axial direction is exemplified. In a modification, the rotor magnet and the sensor magnet may be integrated. In the magnet portion molding step, the rotor magnet portion and the sensor magnet portion may be integrally molded. In that case, the area (outer diameter) of the sensor magnet may be increased so that the magnetic sensor can reliably detect the magnetic flux. Since the sensor magnet protrudes outside the rotor core, injection molding of the sensor magnet and the rotor magnet is facilitated.

In each embodiment, a laminated core (laminated magnetic core) is exemplified as the core of the stator. Alternatively, a dust core or other core may be employed. A dust core is also called a "dust core" and is obtained by pulverizing a soft magnetic material and coating it with a non-conductive resin or the like, kneading the powder with a resin binder, compression molding, and heating.

In each embodiment, the configuration in which the drive circuit, the control circuit, the communication circuit, and the power supply circuit are mounted on the lower surface of the circuit board is exemplified, but the circuits to be mounted can be changed as appropriate. For example, the drive circuit and power supply circuit may be implemented, while the control circuit may be located external to the motor operated valve. Also, each circuit may be mounted on the upper surface of the circuit board.

In each embodiment, a PM stepping motor is used as the motor unit, but a hybrid stepping motor may be used. Also, in the above embodiment, the motor unit is a three-phase motor, but other motors such as two-phase, four-phase, and five-phase motors may be used. The number of electromagnetic coils in the stator is not limited to three or six, and may be appropriately set according to the number of phases of the motor.

The motor-operated valve of each embodiment is suitably applied to a refrigeration cycle that uses a CFC substitute (HFC-134a) as a refrigerant, but it can also be applied to a refrigeration cycle that uses a refrigerant with a high operating pressure, such as carbon dioxide. is. In that case, an external heat exchanger such as a gas cooler is arranged in the refrigeration cycle instead of the condenser.

In each embodiment, the electric valve is configured as an expansion valve, but it may be configured as an on-off valve or a flow control valve that does not have an expansion function.

In each embodiment, an example in which the electric valve is applied to the refrigerating cycle of an automotive air conditioner is shown, but the electric valve is applicable not only to vehicles but also to air conditioners equipped with an electric expansion valve. Also, it can be configured as an electrically operated valve that controls the flow of fluid other than refrigerant.

1 in this embodiment is applicable not only to electric vehicles but also to various vehicles.

The sensor magnet 106 may be magnetized on both sides with four poles (double-sided magnetization with two poles on the single-sided valve main body). Magnetic flux can be strengthened by reversing the polarity of the magnetic poles on the top and bottom surfaces. In this case, even if the rotor 60 is displaced in the valve closing direction and the distance between the sensor magnet 106 and the magnetic sensor 119 increases, the sensitivity of the magnetic sensor 119 can be maintained satisfactorily.

Reference Signs List 1 electric valve, 2 valve body, 3 motor unit, 5 body, 6 first body, 8 second body, 10 male thread, 12 seal housing portion, 14 seal ring, 16 concave fitting portion, 18 seal housing portion, 20 seal ring, 22 valve hole, 24 valve seat, 26 inlet port, 28 outlet port, 30 valve chamber, 32 operating rod, 34 valve body, 36 guide member, 38 male screw, 40 large diameter portion, 42 spring bearing, 44 spring bearing, 46 spring, 52 locking portion, 60 rotor, 62 rotating shaft, 64 stator, 66 can, 70 laminated core, 73 coil, 73a U-phase coil, 73b V-phase coil, 73c W-phase coil, 74 bobbin, 75 coil unit, 76 case, 77 cover, 78 stator unit, 79 connector, 80 seal housing, 81 connection terminal, 82 seal ring, 90 stopper, 102 rotor core, 104 rotor magnet, 106 sensor magnet, 108 female screw, 109 screw feed mechanism, 110 reduced diameter portion 112 bottom portion 114 stopper 116 spring 117 terminal 118 circuit board 119 magnetic sensor 120 slot 122 salient pole 124 slit 140 annular groove 144 annular groove 200 electric valve control device 202 data processing unit, 204 communication unit, 206 reference information storage unit, 208 rotor interface unit, 210 reception unit, 212 transmission unit, 214 rotation instruction unit, 216 rotation detection unit, 218 rotation control unit, 220 step-out detection unit

Claims (8)

A motor-operated valve having a stepping motor that rotates a rotor, a mechanism that converts the rotational motion of the rotor into axial motion of the valve body, and a sensor that detects the angle of the rotor,
a rotation instruction unit for instructing an angle to the stepping motor;
a rotation detection unit that acquires the angle of the rotor from the sensor;
an out-of-step detection unit that determines out-of-step when a difference between the angle of the rotor and the angle instructed to the stepping motor deviates from a reference range. . 2. The motor-operated valve control device according to claim 1, wherein the step-out detector changes the reference range according to the operating state of the motor-operated valve. The step-out detecting section uses the first reference range as the reference range when the valve body is not in contact with the valve seat, and uses the first reference range when the valve body is in contact with the valve seat. 3. The electric valve control device according to claim 1, wherein a second reference range different from the reference range is used as the reference range. 4. The electric valve control device according to claim 3, wherein the second reference range is wider than the first reference range. The step-out detection unit uses the third reference range as the reference range when the step of the stepping motor is changing, and uses the third reference range when the step of the stepping motor is not changing. 5. The electric valve control device according to any one of claims 1 to 4, wherein a fourth reference range different from the reference range is used as the reference range. 6. The electric valve control device according to claim 5, wherein the fourth reference range is narrower than the third reference range. The step-out detection unit detects that the maximum value of the reference range exceeds the upper limit of the predetermined width and shifts to the lower limit when a value that circulates within a predetermined width is used as the parameter indicating the angle of the rotor. When the minimum value of the reference range does not reach the upper limit of the predetermined width and thus the maximum value appears to be smaller than the minimum value, the range from the minimum value of the reference range to the upper limit of the predetermined width 7. The method according to any one of claims 1 to 6, wherein a logical operation is performed to determine the range and the range from the lower limit of the predetermined width to the maximum value of the reference range as the reference range. motorized valve controller. A computer connected to a motor-operated valve having a stepping motor that rotates a rotor, a mechanism that converts the rotational motion of the rotor into axial motion of the valve body, and a sensor that measures the angle of the rotor,
a function of instructing an angle to the stepping motor;
the ability to obtain the angle of the rotor from the sensor;
A motor-operated valve control program for exerting a function of judging out-of-step when a difference between the angle of the rotor and the angle instructed to the stepping motor is out of a reference range.

Images