Control device, valve device, program, storage medium for storing program, and control method

Abstract

[Problem] To develop a technique for reducing a sound that is the sound at the time of origin setting processing and has been often recognized as noise. [Solution] A control device according to the present embodiment is configured to perform: origin setting processing for setting the origin position of a motor by controlling the motor so that a movable part of an electric device using the motor as a drive source is further pressed in the state of abutting on a stopper; and position control processing for controlling the rotation position of the motor with respect to the origin position. The control device is provided with a current setting unit configured to change a drive current so that the drive current to the motor in the origin setting processing becomes smaller than the drive current to the motor in the position control processing.

Description

Control device, valve device, program, storage medium for storing program, and control method

[0001] The present disclosure relates to a control device and control method for performing position control processing of a motor, a valve device equipped with such a control device, a program executed by a computer of such a control device, and a storage medium for storing the program.

[0002] Conventionally, as this type of control device, there is known a device that performs an origin setting process for setting an origin position used in a position control process (see, for example, Patent Document 1). In this origin setting process, the motor is controlled so that a movable part of an electric device using the motor as a drive source is further pressed against a stopper while in contact with the stopper, and then the current position of the motor is set as the origin position.

[0003] JP 2022-171289 A (paragraph

[0052] , FIG. 8)

[0004] However, the sound generated during the above-described origin setting process may be perceived as noise, and there is a need to develop a technique for reducing this noise.

[0005] A control device according to one aspect of the present disclosure is a control device configured to perform an origin setting process that controls a motor so that a movable part of an electric device driven by the motor is further pressed against a stopper while in contact with the stopper, thereby setting the origin position of the motor, and a position control process that controls the rotational position of the motor relative to the origin position, and is a control device that includes a current setting unit configured to change the drive current to the motor in the origin setting process so that the drive current to the motor is smaller than the drive current to the motor in the position control process.

[0006] A program according to one aspect of the present disclosure causes a computer of a control device for an electric device that uses a motor as a drive source to function as an origin setting unit configured to control the motor of the control device to set an origin position of the motor so that the movable part of the electric device is further pressed against a stopper while in contact with it, a position control unit configured to control the rotational position of the motor relative to the origin position, and a current setting unit configured to change the drive current so that the drive current when the origin setting unit controls the motor is smaller than the drive current when the position control unit controls the motor.

[0007] A control method according to one aspect of the present disclosure performs an origin setting process in which an origin position of an electric device driven by a motor is set by controlling the motor so that a movable part of the motor is further pressed against a stopper while in contact with the stopper, and a position control process in which the rotational position of the motor relative to the origin position is controlled, and the control method changes the drive current to the motor in the origin setting process so that the drive current to the motor is smaller than the drive current to the motor in the position control process.

[0008] 1 is a side cross-sectional view of a flow control valve according to a first embodiment of the present disclosure. FIG. 2 is a circuit diagram of a control device. FIG. 3 is a conceptual diagram of an excitation pattern. FIG. 4 is a program flowchart. FIG. 5A is a conceptual diagram of an excitation pattern, FIG. 5B is a conceptual diagram of a current control pulse signal, and FIG. 5C is a conceptual diagram of an on / off control signal. FIG. 6 is a block diagram of a control circuit. FIG. 7 is a block diagram of a control circuit.

[0009] 1 to 9, a valve device 10 according to a first embodiment of the present disclosure will be described. The valve device 10 includes a flow control valve 11 as an electrically driven device and a control device 30A that controls the flow control valve 11. A motor 12, which is the drive source of the flow control valve 11, is, for example, a stepping motor, and includes a central shaft 14 of its rotor 13 and a base portion 20 that rotatably supports the central shaft 14, which has a male screw portion 14N and a female screw portion 20N that threadably engage with each other. As a result, a valve element 18, which will be described below, moves linearly as the rotor 13 rotates.

[0010] A central hole 14A is formed at one end of the central shaft 14, and the base end of a needle-shaped valve element 18 is fitted therein in a slidable but retained manner. A compression coil spring 18S housed in the central hole 14A biases the valve element 18 in the direction that it protrudes from the central shaft 14.

[0011] The base portion 20 is formed with a first hole 21A extending coaxially with the central shaft 14 and a second hole 21B laterally communicating with the first hole 21A, forming an L-shaped flow path 21 through which a fluid can pass from the first hole 21A and the second hole 21B. The first hole 21A is narrowed at a portion away from the second hole 21B to form a valve hole 22. The valve element 18 moves linearly toward and away from the valve hole 22, changing the opening degree of the valve hole 22 and changing the flow rate of the fluid passing through the flow path 21. When the valve element 18 abuts against a valve seat 23, which is part of the inner surface of the valve hole 22, the valve hole 22 is closed.

[0012] A screw guide 19G, formed by spirally wound wire, is fixed to the end of the central shaft 14 opposite the valve body 18 so as to rotate integrally with the central shaft 14. A stopper 19A, formed by spirally wound wire with a larger diameter and shorter length than the screw guide 19G, is threadedly engaged with the outer surface of the screw guide 19G. A pair of stopper abutment portions 19S1, 19S2 are provided at both ends of the screw guide 19G, and the stopper 19A abuts against the pair of stopper abutment portions 19S1, 19S2 to prevent it from coming off the screw guide 19G. Furthermore, a rotation restriction bar 90A extends parallel to the central shaft 14 from one end of a rotor case 90 that houses the rotor 13 of the motor 12. The rotation restriction bar 90A is positioned to the side of the screw guide 19G, and a portion of the stopper 19A abuts against the rotation restriction bar 90A. The rotation limiting mechanism 19K, which includes the screw guide 19G, the stopper 19A, and the rotation restricting bar 90A, causes the stopper 19A to move linearly along the rotation restricting bar 90A as the rotor 13 rotates. When the rotor 13 rotates in one direction, as shown in Figure 1, the stopper 19A abuts against one stopper abutment portion 19S1, positioning the rotor 13 at one end of its rotatable range. When the rotor 13 rotates multiple times in the other direction from that end position, the stopper 19A abuts against the other stopper abutment portion 19S2, positioning the rotor 13 at the other end of its rotatable range. The rotatable range of the rotor 13 is stored in a memory 36B, which will be described later, as a maximum rotatable angle θmax of the rotor 13.

[0013] In the flow control valve 11 of this embodiment, one end position of the rotatable range of the rotor 13, which is positioned by the stopper abutment portion 19S1, is set as an origin position for controlling the rotational position of the rotor 13 by a control device 30A (described below) (i.e., for controlling the position of the motor 12). Furthermore, at this end position of the rotor 13, i.e., the origin position, the valve element 18 abuts against the valve seat 23, and the compression coil spring 18S is in a slightly deflected state.

[0014] In this embodiment, the stopper abutment portion 19S1 that positions the rotor 13 at the home position is provided inside the motor 12, but it may be provided outside the motor 12. For example, the valve element 18 may be configured to abut against the valve seat 23 as a stopper, thereby positioning the rotor 13 at the home position. In this case, it is preferable that the valve element 18 is fixed so as not to slide relative to the central shaft 14. Furthermore, in this embodiment, when the rotor 13 is located at the home position, the valve element 18 abuts against the valve seat 23 and the valve hole 22 is fully closed. However, when the rotor 13 is located at the home position, the valve element 18 may be slightly separated from the valve seat 23, allowing a small amount of fluid to pass through the valve hole 22.

[0015] 2, the control device 30A includes a drive circuit 33 for driving the motor 12 and a control circuit 36 ​​for controlling the drive circuit 33. To explain the configuration of the drive circuit 33, the configuration of the motor 12 will be explained more specifically. As shown in FIG. 1, the motor 12 is a claw-pole stepping motor having a permanent magnet 13M (see FIG. 1) in the rotor 13 and two-phase coils 91, 92 in the stator 93.

[0016] 2, the drive circuit 33 is connected to the coils 91 and 92 in, for example, a unipolar configuration and has four switches 31A, 31a, 32B, and 32b, with one coil 91 divided into coils A and a, and the other coil 92 divided into coils B and b. The switches 31A, 31a, 32B, and 32b correspond one-to-one to the coils A, a, B, and b, and when any of the switches is turned on, a drive current is passed through the corresponding coil.

[0017] The control circuit 36 ​​includes a CPU 36A and a memory 36B, which is a computer-readable storage medium for storing information. An excitation pattern P for rotating the rotor 13 is stored in the memory 36B, an example of which is shown in FIG. 3 . As shown in FIG. 3 , the excitation pattern P is composed of excitation patterns PA, Pa, PB, and Pb for the coils A, a, B, and b, respectively. In FIG. 3 , the horizontal axis represents time and the number of steps. In this example excitation pattern, one electrical rotation of the rotor 13 is divided into four steps ST. Each time step ST is switched in the direction of the time axis in FIG. 3 , the combination of excitation and non-excitation of coils A, a, B, and b is switched, and the rotor 13 is rotated in the valve closing direction by one-quarter of an electrical rotation. Furthermore, by switching step ST in the direction opposite to the direction of the time axis in FIG. 3 , the rotor 13 is rotated in the valve opening direction. In addition, by arbitrarily changing the execution time of each step ST of the excitation pattern (hereinafter referred to as "step width"), it is possible to arbitrarily change the rotation speed and rotation acceleration of the rotor 13. Furthermore, by arbitrarily changing the number of steps constituting the excitation pattern, it is possible to arbitrarily change the rotation angle of the rotor 13.

[0018] The memory 36B stores a program PG1 shown in Fig. 4. This program PG1 is executed, for example, when the control device 30A is powered on. When the program PG1 is executed, first, a preset first rotation speed ω1 is set as the target rotation speed ωx (S11), and a preset rotation acceleration speed μ0 is set as the target rotation acceleration μx (S12).

[0019] Next, a preset first drive current I1 is set as the target drive current Ix to be supplied to the coils A, a, B, and b (S13). The target drive current Ix is used to control the drive current when driving the motor 12 in the origin setting process (S14) described below. Since this control is performed using PWM control, the first drive current I1 set as the target drive current Ix and a second drive current I2 (described later) are set with a duty ratio. The second drive current I2 is set to 100%, while the first drive current I1 is set to a smaller duty ratio. More specifically, the first drive current I1 is set to a value corresponding to the minimum drive current required for the rotor 13 to rotate against frictional resistance, etc., which is actually measured.

[0020] Next, an origin setting process (S14) is executed. When the origin setting process (S14) is executed, origin setting excitation patterns PA, Pa, PB, Pb (see FIG. 5A) for rotating the rotor 13 in the valve closing direction by a target rotation angle θx obtained by adding a preset additional rotation angle θa to the maximum rotatable angle θmax are generated, and a current control pulse signal Y1 having a constant period t sufficiently smaller than the step width T of the origin setting excitation patterns PA, Pa, PB, Pb is generated (see FIG. 5B). At this time, the step length of each of the origin setting excitation patterns PA, Pa, PB, Pb is set to a length for rotating the rotor 13 at the target rotation speed ωx and target rotation acceleration μx, and the duty ratio of the minute pulse signal is set to the duty ratio of the first target drive current Ix. Then, the origin setting excitation patterns PA, Pa, PB, Pb are stepped, and only when the origin setting excitation patterns PA, Pa, PB, Pb are in the on state, the current control pulse signal Y1 is output as the on / off control signals ZA, Za, ZB, Zb (see Figure 5C) for the switches 31A, 31a, 32B, 32b.

[0021] When the switches 31A, 31a, 32B, and 32b are turned on and off by the on / off control signals ZA, Za, ZB, and Zb, the excitation states of the coils A, a, B, and b are switched so that the rotor 13 rotates in the valve-closing direction by the target rotation angle θx. However, before the rotation angle of the rotor 13 reaches the target rotation angle θx, the stopper 19A and the stopper abutment portion 19S1 abut against each other, rendering the rotor 13 unable to rotate. Since the excitation states of the coils A, a, B, and b continue to be switched so as to rotate the rotor 13 in the valve-closing direction, the motor 12 repeatedly loses and regains synchronization while the stopper 19A is pressed against the stopper abutment portion 19S1.

[0022] Here, the noise generated when the motor 12 repeatedly steps out and demodulates may be louder than the noise generated when the rotor 13 is operating without stepping out. However, in the program PG1, the drive current applied to the motor 12 (specifically, coils A, a, B, and b) in the origin setting process (S14) is PWM controlled to a drive current having a duty ratio equal to the current control pulse signal Y1 described above, and is therefore smaller than the drive current applied to the motor 12 in the position control process (S17) described below, thereby suppressing the output torque of the motor 12. This reduces the noise caused by the step-out and demodulation of the motor 12 in the origin setting process (S14).

[0023] When the above-described on / off control signals are sent up to the last step of the origin setting excitation patterns PA, Pa, PB, and Pb, the excitation states of coils A, a, B, and b are maintained at the excitation states of the last step. The rotational position of the rotor 13 at this time is set as the origin position. Then, each time the rotor 13 is rotated, the current rotational position of the rotor 13 is updated and stored in memory 36B as the "number of steps away from the origin position." In this way, the origin position is identified from the current rotational position updated and stored in memory 36B. In other words, the origin position is set by storing the current rotational position of the rotor 13 in memory 36B.

[0024] When the origin setting process (S14) is completed, the target rotational speed ωx is set to a second rotational speed ω2 that is greater than the first rotational speed ω1 (S15), and the target drive current Ix is set to a second drive current I2 that is greater than the first drive current I1 (S16). In this embodiment, since the second drive current I2 is set to, for example, 100%, when the second drive current I2 is set to the target drive current Ix, PWM control of the drive current of the motor 12 is not substantially performed.

[0025] Next, a position control process (S17) is executed. When the position control process (S17) is executed, the control device 30A waits until command data is provided from outside the control device 30A, for example. Here, the command data is provided as, for example, a target valve opening or a target flow rate of the flow control valve 11. The memory 36B also stores a data table that associates the command data with a target rotational position of the rotor 13. Then, in the position control process (S17), when the command data is provided, the target rotational position corresponding to the command data is determined based on the data table. Then, from the current rotational position and the target rotational position of the rotor 13, excitation patterns PA, Pa, PB, and Pb for rotating the rotor 13 to the target rotational position at a target rotational speed ωx and a target rotational acceleration μx are provided to each of the switches 31A, 31a, 32B, and 32b as on / off control signals ZA, Za, ZB, and Zb.

[0026] As a result, the motor 12 is driven with a larger drive current and at a faster rotation speed than during the origin setting process, and the flow control valve 11 reaches the target valve opening according to the command data. Then, the position control process (S17) is executed every time command data is received, whereby flow control by the flow control valve 11 is performed.

[0027] It should be noted that a stepping motor has the characteristic that the output torque increases as the rotational speed of the rotor 13 decreases. However, due to the difference between the first drive current I1 and the second drive current I2 set as the target drive current Ix in the program PG1 of this embodiment, the output torque is smaller during the origin setting process, when the rotational speed of the rotor 13 is lower than during the position control process.

[0028] When executing the program PG1, the CPU 36A functions as a speed setting unit 41, an acceleration setting unit 42, a current setting unit 43, a rotation angle setting unit 44, a first pulse signal generating unit 45, a second pulse signal generating unit 46, an AND circuit 47, an execution control unit 49, and the like, all of which are shown in the block diagram of FIG. 6 . The speed setting unit 41 sets the target rotation speed ωx to the first or second rotation speed ω1 or ω2, and the acceleration setting unit 42 sets the target rotation acceleration μx to the rotation acceleration μ0. The rotation angle setting unit 44 determines the target rotation angle θx from external command data and a data table. Then, based on power-on information, the execution control unit 49 determines whether to provide the first pulse signal generating unit 45 with the target rotation angle θx determined by the rotation angle setting unit 44 or the target rotation angle θx determined from the maximum rotatable angle θmax and the additional rotation angle θa.

[0029] The current setting unit 43 sets the target drive current Ix to either the first drive current I1 or the second drive current I2. Immediately after powering on the control device 30A, the first pulse signal generating unit 45 acquires data on the target rotational speed ωx, the target rotational acceleration μx, and the target rotational angle θx, generates excitation pattern pulse signals XA, Xa, XB, and Xb for setting the origin, and outputs them separately to the multiple AND circuits 47. Thereafter, the first pulse signal generating unit 45 generates excitation pattern pulse signals XA, Xa, XB, and Xb based on command data, and outputs them separately to the multiple AND circuits 47.

[0030] The second pulse signal generating unit 46 acquires the target drive current Ix, generates a current control pulse signal Y1 having a duty ratio corresponding to the target drive current Ix, and outputs the generated signal to a plurality of AND circuits 47. The plurality of AND circuits 47 then perform AND processing on the excitation pattern pulse signals XA, Xa, XB, and Xb and the current control pulse signal Y1 to generate on / off control signals ZA, Za, ZB, and Zb, and output the signals to the switches 31A, 31a, 32B, and 32b.

[0031] Here, when the first pulse signal generating unit 45 receives the target rotation angle θx determined from the command data, it becomes a position control unit 52 for performing position control, and when the first pulse signal generating unit 45 receives the target rotation angle θx determined from the maximum rotatable angle θmax and the additional rotation angle θa, it becomes an origin setting unit 51 for performing origin setting processing. Furthermore, when performing position control, the duty ratio of PWM control becomes 100%, and PWM control is not actually performed, so the CPU 36A when executing the above program PG1 can also be shown in the block diagrams of Figures 7 to 9.

[0032] This completes the description of the configuration of this embodiment. According to the control device 30A, program PG1, and control method for the flow control valve 11 of this embodiment, as described above, the drive current to the motor 12 in the origin setting process (S14) is changed so that it is smaller than the drive current to the motor 12 in the position control process (S17). This reduces noise during the origin setting process compared to the conventional method in which the motor 12 is driven with the same drive current during both the position control process and the origin setting process. Furthermore, because the drive current to the motor 12 in the origin setting process (S14) is set to the minimum required to rotate the rotor 13, noise during the origin setting process can be minimized. Furthermore, because the rotational speed of the motor 12 in the origin setting process (S14) is slower than the rotational speed of the motor 12 in the position control process (S17), this also reduces noise during the origin setting process.

[0033] As described above, according to the configuration of this embodiment, the noise generated during the origin setting process is reduced compared to the conventional case in which the motor 12 is driven with the same drive current and at the same rotational speed during the position control process and the origin setting process, thereby meeting the demand for quietness.

[0034] In this embodiment, the drive current to the motor 12 in the origin setting process (S14) is measured to set the minimum required magnitude and determined for each flow control valve 11, but if the drive current to the motor 12 in the origin setting process (S14) is smaller than the drive current to the motor 12 in the position control process (S17), the drive current to the motor 12 in the origin setting process (S14) may be determined uniformly for multiple flow control valves 11 without actual measurement. Also, in this embodiment, the rotation speed of the motor 12 when performing the origin setting process (S14) is slower than the rotation speed of the motor 12 when performing the position control process (S17), but the rotation speed of the motor 12 may be the same between the origin setting process (S14) and the position control process (S17).

[0035] Second Embodiment This embodiment is shown in FIGS. 10 and 11, and differs from the first embodiment in the configuration of the drive circuit 33 of the control device 30A and the program PG2.

[0036] As shown in FIG. 10 , in the drive circuit 33, the terminals of the coils A, a, B, and b that are not connected to the corresponding switches 31A, 31a, 32B, and 32b are commonly connected to the power supply 34. A selection switch 35 and first and second resistors R1 and R2 serving as current-reducing elements are connected between the common connection and the power supply 34. The selection switch 35 selectively connects either the first or second resistor R1 or R2 between the power supply 34 and the coils A, a, B, and b. The first resistor R1 has a larger resistance than the second resistor R2, thereby restricting the current that can pass through. In other words, the drive current flowing through the coils A, a, B, and b is smaller when the first resistor R1 is connected to the power supply 34 than when the second resistor R2 is connected to the power supply 34.

[0037] 11 , in the program PG2 of the present embodiment, instead of step S13 of the program PG1 of the first embodiment, the selection switch 35 is set so that the first resistor R1 is connected to the power supply 34 (S20). Then, in the origin setting process (S14), the current control pulse signal Y1 is not generated, and the origin setting excitation patterns PA, Pa, PB, and Pb (see FIG. 5A ) are applied to the switches 31A, 31a, 32B, and 32b as on / off control signals ZA, Za, ZB, and Zb. After the origin setting process (S14) is completed, instead of step S16 of the program PG1 of the first embodiment, the selection switch 35 is switched so that the second resistor R2 is connected to the power supply 34 (S21).

[0038] In this way, in this embodiment, the current setting unit 35K is composed of the selection switch 35 and the first and second resistors R1 and R2, and similar to the configuration of the first embodiment, the noise during the origin setting process is reduced compared to the conventional configuration, making it possible to meet the demand for high quietness when such demands are met.

[0039] As a modification of this embodiment, instead of the configuration in which the first and second resistors R1 and R2 are selectively switched, the output voltage of the power supply device 34 may be switched between the first and second output voltages. Even with such a configuration, the same effect can be obtained.

[0040] 12 and 13, the program PG3 differs from that of the first embodiment. The program PG3 is executed immediately after the control device 30A is powered on, and is also interrupted and terminated each time a predetermined time (e.g., 12 hours, 24 hours, etc.) has elapsed since power was turned on, and then executed again from the beginning. Furthermore, the current position information of the rotor 13, which is updated and stored in the memory 36B, is reset (i.e., erased) when power supply to the control device 30A is stopped, but is maintained without being reset when the interruption of the program PG3 is terminated.

[0041] When program PG3 is executed, a preset value μ0 is set as the target rotational acceleration μx (S30). Then, it is checked whether the origin setting process has been completed (S31). Specifically, for example, whether the origin setting process has been completed is checked based on whether information on the current position of the rotor 13 is stored in memory 36B.

[0042] If the origin setting process has not been completed (NO in S31), the first rotation speed ω1 is set as the target rotation speed ωx (S41), the first drive current I1 is set as the target drive current Ix (S42), and then the same origin setting process (S43) as the origin setting process (S14) described in the first embodiment is performed.

[0043] On the other hand, if the origin setting process has been completed (YES in S31), the target rotational speed ωx is set to the second rotational speed ω2 (S32), the target drive current Ix is set to the second drive current I2 (S33), and then the origin return position control process (S34) is performed. Then, the target rotational speed ωx is set to the first rotational speed ω1 (S35), the target drive current Ix is set to the first drive current I1 (S36), and then the origin setting process for update (S37) is performed. Here, the first rotational speed ω1 is smaller than the second rotational speed ω2, and the first drive current I1 is smaller than the second drive current I2. This is the same as in the first embodiment.

[0044] In the position control process for returning to the origin (S34), the same process as the position control process (S17) described in the first embodiment is performed to move the rotor 13 to the origin position. Furthermore, the origin setting process for updating (S37) is the same as the origin setting process (S14) described in the first embodiment except that the additional rotation angle θa is set as the target rotation angle θx for rotating the rotor 13 in the valve closing direction.

[0045] As a result, when program PG3 is executed immediately after powering on control device 30A and then executed again, rotor 13 is rotated and driven to the origin position at the rotational speed and drive current of normal position control, and then coils A, a, B, and b are excited so that rotor 13 is further rotated in the same direction at a rotational speed and drive current slower than those of normal position control, and stopper 19A is pressed against stopper abutment portion 19S1. The rotational position of rotor 13 is then stored in memory 36B as the origin position.

[0046] When either the origin setting process (S43) or the update origin setting process (S37) is completed, the second rotation speed ω2 is set as the target rotation speed ωx (S38), and the second drive current I2 is set as the target drive current Ix (S39), and then the same position control process (S40) as the position control process (S17) described in the first embodiment is performed.

[0047] 13, and checks whether there is information on the current position of the rotor 13 to be updated and stored in the memory 36B. When the discriminator 48 determines that there is information on the current position, the result of the determination is received by the execution control unit 49, which controls whether the first pulse signal generator 45 functions as an origin setting unit 51 or as a position control unit 52.

[0048] According to the configuration of this embodiment, even if a large resistance is encountered while the rotor 13 is being moved from a position away from the origin position to the origin position, the origin setting process can be performed after the rotor 13 is reliably moved to the origin position. More specifically, for example, when a fluid is flowing through the flow path 21 in the flow control valve 11, it is assumed that the valve element 18 will encounter a large fluid resistance before being moved to the origin position, and in such a case, the configuration of this embodiment is effective.

[0049] In this embodiment, not only the target drive current Ix but also the target rotation speed ωx is switched, but the target rotation speed ωx may be fixed to a constant value.

[0050] Other Embodiments In the above embodiment, the electrically-powered device having the motor 12 controlled by the control device 30A is the flow control valve 11, but is not limited to this and may be, for example, a printer, a toy, or the like.

[0051] While the motor 12 in the above embodiment is a PM-type stepping motor with a permanent magnet 13M in the rotor 13, the present invention is not limited to this. For example, the motor may be a variable reluctance type with a gear-shaped iron core in the rotor 13, or a hybrid type in which both a permanent magnet and a gear-shaped iron core are used in the rotor 13. Furthermore, while the motor 12 in the above embodiment is a claw-pole stepping motor in which multiple phase coils 91, 92 are arranged in the direction of the rotation axis on the stator side, the motor may also have a structure in which multiple teeth are arranged in the circumferential direction on the stator side and a coil is wound around each tooth. Furthermore, the motor does not have to be a stepping motor as long as it requires setting of the origin position, and may be, for example, a servo motor equipped with a resolver as a rotation sensor.

[0052] If the motor 12 is a stepping motor, the drive circuit 33 that drives the motor 12 is not limited to the unipolar wiring illustrated in the above embodiment, but may be bipolar wiring. Furthermore, the excitation pattern was full-step excitation, in which a constant voltage is applied to the coils 91 and 92, but may also be half-step excitation or microstep excitation, in which the applied voltage is divided into multiple steps. Furthermore, while multi-phase excitation was used, in which multiple phase coils are simultaneously excited, single-phase excitation may also be used. In the above-described modified example, the drive current to the motor 12 may be changed between the origin setting process and the position control process by performing PWM control as in the above embodiment, or may be changed by means other than the PWM control described in the second embodiment.

[0053] In the above embodiment, the rotational acceleration is constant between the origin setting process and the position control process, but the rotational acceleration may be different between the origin setting process and the position control process.

[0054] <Supplementary Notes> Below, the group of features extracted from the above embodiment will be explained, indicating, as necessary, the effects, etc. Note that, for ease of understanding, the corresponding configurations in the above embodiment will be indicated in parentheses as appropriate below, but these group of features are not limited to the specific configurations indicated in parentheses.

[0055] [Feature 1] A control device (30A) configured to perform an origin setting process (S14, S37, S43) for setting an origin position of the motor (12) by controlling the motor (12) so that a movable part (19S1) of an electric device (11) using the motor (12) as a drive source is further pressed against a stopper (19A) while in contact with the stopper (19A), and a position control process (S17, S34, S40) for controlling a rotational position of the motor (12) relative to the origin position, the control device (30A) including a current setting unit (35K, 43) configured to change a drive current to the motor (12) in the origin setting process (S14, S37, S43) so that the drive current to the motor (12) is smaller than the drive current to the motor (12) in the position control process (S17, S34, S40).

[0056] [Feature 2] The control device (30A) according to Feature 1, configured to perform a preliminary position control process (S34) to match the rotational position of the motor (12) with the origin position before the origin setting process (S14, S37, S43) is performed.

[0057] [Feature 3] The control device (30A) according to Feature 1, comprising: a determination unit (48) configured to determine whether the origin position has been set or not; and an execution control unit (49) configured to, if the origin position has been set, perform a preliminary position control process (S34) to match the rotational position of the motor (12) with the origin position before performing the origin setting process (S37), while, if the origin position has not been set, control execution of the preliminary position control process (S34) so ​​that the preliminary position control process (S34) is not performed before performing the origin setting process (S43).

[0058] [Feature 4] The control device (30A) according to any one of Features 1 to 3, further comprising: a speed setting unit (41) configured to make the rotation speed of the motor (12) in the origin setting process (S14, S37, S43) smaller than the rotation speed of the motor (12) in the position control process (S17, S34, S40).

[0059] [Feature 5] The control device (30A) according to any one of Features 1 to 3, wherein the control device (30A) is configured to make the rotation speed of the motor (12) in the origin setting process (S14, S37, S43) equal to the rotation speed of the motor (12) in the position control process (S17, S34, S40).

[0060] [Feature 6] The control device (30A) according to any one of Features 1 to 5, wherein the drive current to the motor (12) in the origin setting process (S14, S37, S43) is set to an individual magnitude for each of the electrically-driven devices (11).

[0061] [Feature 7] The control device (30A) according to any one of Features 1 to 6, wherein the motor (12) is provided with a rotation limiting mechanism (19K) that limits the rotatable range of the rotor to a plurality of revolutions, and the stopper (19A) is provided as a part of the rotation limiting mechanism (19K).

[0062] [Feature 8] The control device (30A) according to any one of Features 1 to 6, wherein the electric device (11) is a flow control valve (11), the movable part (19S1) is a valve body (18) of the flow control valve (11), and the stopper (19A) is a valve seat (23) of the flow control valve (11).

[0063] [Feature 9] A valve device (10) comprising: the control device (30A) according to any one of Features 1 to 8; and a flow control valve (11) controlled by the control device (30A).

[0064] [Feature 10] Programs (PG1 to PG3) that cause a computer (36A) of a control device (30A) for an electric device (11) using a motor (12) as a drive source to function as: an origin setting unit (51) configured to control the motor (12) of the control device (30A) to set an origin position of the motor (12) so that a movable part (19S1) of the electric device (11) is further pressed against a stopper (19A) while in contact with the stopper; a position control unit (52) configured to control the rotational position of the motor (12) relative to the origin position; and a current setting unit (35K, 43) configured to change the drive current so that the drive current when the origin setting unit (51) controls the motor (12) is smaller than the drive current when the position control unit (52) controls the motor (12).

[0065] [Feature 11] The program (PG3) according to Feature 10, which causes the computer (36A) to function as an execution control unit (49) configured to control activation of the position control unit (52) so that the position control unit (52) is activated and the rotational position of the motor (12) coincides with the origin position before activation of the origin setting unit (51).

[0066] [Feature 12] The program (PG3) according to Feature 10 causes the computer (36A) to function as: a discrimination unit (48) configured to determine whether the origin position has been set or not; and an execution control unit (49) configured to, if the origin position has been set, activate the position control unit (52) before activation of the origin setting unit (51) to make the rotational position of the motor (12) coincide with the origin position; and, if the origin position has not been set, control activation of the position control unit (52) so that the position control unit (52) does not activate before activation of the origin setting unit (51).

[0067] [Feature 13] The program (PG3, PG3) according to any one of Features 10 to 12, which causes the computer (36A) to function as a speed setting unit (41) configured to make the rotation speed of the motor (12) controlled by the origin setting unit (51) smaller than the rotation speed of the motor (12) controlled by the position control unit (52).

[0068] [Feature 14] The program (PG1) according to any one of Features 10 to 12, which causes the computer (36A) to function as a speed setting unit (41) configured to make the rotation speed of the motor (12) controlled by the origin setting unit (51) and the rotation speed of the motor (12) controlled by the position control unit (52) the same.

[0069] [Feature 15] A storage medium (36B) that stores the program (PG1) according to any one of Features 10 to 14.

[0070] [Feature 16] A control method that performs an origin setting process (S14, S37, S43) that sets an origin position of the motor (12) by controlling the motor (12) so that a movable part (19S1) of an electric device (11) using the motor (12) as a drive source is further pressed against a stopper (19A) while in contact with the stopper (19A), and a position control process (S17, S34, S40) that controls a rotational position of the motor (12) relative to the origin position, wherein the control method changes the drive current to the motor (12) in the origin setting process (S14, S37, S43) so that the drive current to the motor (12) is smaller than the drive current to the motor (12) in the position control process (S17, S34, S40).

[0071] [Feature 17] The control method according to Feature 16, wherein the position control process (S34) is performed in advance to match the rotational position of the motor (12) with the origin position before the origin setting process (S37) is performed.

[0072] [Feature 18] The control method according to Feature 16, wherein it is determined whether the origin position has been set or not, and if the origin position has been set, a preliminary position control process (S34) is performed to match the rotational position of the motor (12) with the origin position before the origin setting process (S37) is performed, whereas if the origin position has not been set, the preliminary position control process (S34) is not performed before the origin setting process (S43) is performed.

[0073] [Feature 19] The control method according to any one of Features 16 to 18, wherein a first drive current (I1), which is the drive current minimum required to rotate the rotor of the motor (12), is actually measured and stored, and in the origin setting process (S14), the first drive current (I1) is applied to the motor (12).

[0074] [Feature 20] The control method according to any one of Features 16 to 19, wherein the rotation speed of the motor (12) in the origin setting process (S14, S37, S43) is set to be smaller than the rotation speed of the motor (12) in the position control process (S17, S34, S40).

[0075] [Feature 21] The control method according to any one of Features 16 to 19, wherein the rotation speed of the motor (12) in the origin setting process (S14) is made the same as the rotation speed of the motor (12) in the position control process (S17).

[0076] According to the control device of Feature 1, the program of Feature 10, the storage medium of Feature 15, and the control method of Feature 16, the drive current to the motor in the origin setting process is changed so that it is smaller than the drive current to the motor in the position control process, thereby reducing the noise during the origin setting process compared to the conventional case in which the motor is driven with the same drive current during the position control process and the origin setting process. Furthermore, according to the valve device of Feature 9, which controls a flow control valve with this control device, it is possible to meet the demand for quietness when used in an air conditioning system.

[0077] According to the control device of Features 2 and 3, the program of Features 11 and 12, and the control method of Features 17 and 18, even if a large resistance is applied during the movement from a position away from the origin position to the origin position, the origin setting process can be performed after the movement to the origin position with reliability.

[0078] According to the control device of Feature 4, the program of Feature 13, and the control method of Feature 20, the rotational speed of the motor in the origin setting process is lower than the rotational speed of the motor in the position control process, thereby reducing the noise generated during the origin setting process compared to conventional methods in which the motor was driven at the same rotational speed during the position control process and the origin setting process. Note that, as in the control device of Feature 5, the program of Feature 14, and the control method of Feature 20, if the rotational speed of the motor in the origin setting process is made the same as or faster than the rotational speed of the motor in the position control process, the origin setting process can be performed quickly.

[0079] In the control device of Feature 6, the drive current to the motor during the origin setting process is set to an individual value for each electrically driven device, so it is possible to accommodate the drive current to the motor that varies from one electrically driven device to another. Furthermore, as in the control method of Feature 19, the origin setting process can be performed with the minimum drive current required to drive the motor of each electrically driven device, and the noise during the origin setting process can be minimized.

[0080] Although the present specification and drawings disclose specific examples of the technology included in the scope of the claims, the technology described in the claims is not limited to these specific examples, but also includes various modifications and variations of the specific examples, and also includes parts of the specific examples taken out alone.

[0081] 10 Valve device 11 Flow control valve (electric device) 12 Motor 14S Origin setting process 16S Position control process 18 Valve body 19A Stopper 19K Rotation limiting mechanism 23 Valve seat 30A Control device 35K, 43 Current setting section 36A CPU (computer) 36B Memory 41 Speed ​​setting section 43 Current setting section 48 Discrimination section 49 Execution control section 51 Origin setting section 52 Position control section PG1 to PG3 Program

Claims

1. A control device configured to perform an origin setting process for setting an origin position of the motor by controlling the motor so that a movable part of an electric device driven by the motor is further pressed against a stopper while in contact with the stopper, and a position control process for controlling a rotational position of the motor relative to the origin position, a control device including a current setting unit configured to change the drive current to the motor in the origin setting process so that the drive current to the motor in the position control process is smaller than the drive current to the motor in the position control process;

2. 2. The control device according to claim 1, wherein the control device is configured to perform a preliminary position control process to match the rotational position of the motor with the origin position before the origin setting process is performed.

3. a determination unit configured to determine whether the origin position has been set or not; 2. The control device according to claim 1, further comprising: an execution control unit configured to, when the origin position has already been set, perform a preliminary position control process to match the rotational position of the motor to the origin position before the origin setting process is performed, while, when the origin position has not yet been set, control the execution of the preliminary position control process so that the preliminary position control process is not performed before the origin setting process is performed.

4. 4. The control device according to claim 1, further comprising a rotation speed setting unit configured to make the rotation speed of the motor in the origin setting process slower than the rotation speed of the motor in the position control process.

5. 4. The control device according to claim 1, wherein the rotation speed of the motor in the origin setting process is set to be the same as the rotation speed of the motor in the position control process.

6. 4. The control device according to claim 1, wherein the drive current to the motor in the origin setting process is set to an individual value for each of the electrically driven devices.

7. 4. The control device according to claim 1, wherein the motor is provided with a rotation limiting mechanism that limits the rotatable range of the rotor to a plurality of rotations, and the stopper is provided as part of the rotation limiting mechanism.

8. 4. The control device according to claim 1, wherein the motorized device is a flow control valve, the movable part is a valve body of the flow control valve, and the stopper is a valve seat of the flow control valve.

9. A control device according to any one of claims 1 to 3; a flow control valve controlled by the control device.

10. A computer for a control device for an electric device driven by a motor, an origin setting unit configured to control the motor of the control device so that the movable part of the electric device is further pressed against a stopper while in contact with the stopper, thereby setting an origin position of the motor; a position control unit configured to control a rotational position of the motor relative to the origin position; a current setting unit configured to change the drive current when the origin setting unit controls the motor so that the drive current is smaller than the drive current when the position control unit controls the motor; A program that functions as a

11. The computer The program according to claim 10, which functions as an execution control unit configured to control the activation of the position control unit so that the position control unit is activated before the origin setting unit is activated and the rotational position of the motor coincides with the origin position.

12. The computer a determination unit configured to determine whether the origin position has been set or not; an execution control unit configured to, when the origin position has already been set, activate the position control unit and make the rotational position of the motor coincide with the origin position before activation of the origin setting unit, and, when the origin position has not yet been set, control activation of the position control unit so that the position control unit does not activate before activation of the origin setting unit; The program according to claim 10, which causes the program to function as

13. The computer 13. The program according to claim 10, wherein the program functions as a rotational speed setting unit configured to make the rotational speed of the motor controlled by the origin setting unit smaller than the rotational speed of the motor controlled by the position control unit.

14. The computer 13. The program according to claim 10, which functions as a rotational speed control unit configured to control the rotational speed of the motor controlled by the origin setting unit so that the rotational speed of the motor controlled by the position control unit is the same.

15. A storage medium storing the program according to any one of claims 10 to 12.

16. A control method comprising: an origin setting process for setting an origin position of the motor by controlling the motor so that a movable part of an electric device driven by the motor is further pressed against a stopper while the movable part is in contact with the stopper; and a position control process for controlling a rotational position of the motor relative to the origin position, A control method for changing the drive current to the motor in the origin setting process so that the drive current to the motor in the position control process is smaller than the drive current to the motor in the position control process.

17. 17. The control method according to claim 16, wherein the position control process is performed in advance to match the rotational position of the motor with the origin position before the origin setting process is performed.

18. determining whether the origin position has been set or not; 17. The control method according to claim 16, wherein, if the origin position has already been set, a preliminary position control process is performed before the origin setting process is performed to match the rotational position of the motor to the origin position, whereas, if the origin position has not yet been set, the preliminary position control process is not performed before the origin setting process is performed.

19. 19. A control method according to any one of claims 16 to 18, wherein a first drive current, which is the minimum drive current required to rotate the rotor of the motor, is measured and stored, and in the origin setting process, the first drive current is applied to the motor.

20. 19. The control method according to claim 16, wherein the rotation speed of the motor in the origin setting process is set to be lower than the rotation speed of the motor in the position control process.

21. 19. The control method according to claim 16, wherein the rotation speed of the motor in the origin setting process is set to be the same as the rotation speed of the motor in the position control process.

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