KR100387976B1 - Motor actuator - Google Patents

Abstract

The task is to provide a motor actuator capable of simplifying the device by reducing the number of parts and stabilizing the operation of a washing machine or a ventilation line.

As a means for solving this problem, a motor actuator having a motor 14 and an output shaft 30 which is rotationally driven by the motor 14 and connected to the operation member, and which operates the operation member by the driving force of the motor 14. In (1), the cam 40 driven by the motor 14 and the switches 70a and 70b operated by this cam 40 are arrange | positioned, and the magnitude | size of the voltage applied to the motor 14 is arrange | positioned. By switching by switching the switches 70a and 70b, the operation mode of the operation member is changed.

Description

Motor Actuator {MOTOR ACTUATOR}

The present invention relates to an improvement of a motor actuator for driving a drain valve of a washing machine, a shutter of a ventilation line, and the like.

Background Art Conventional techniques have been proposed in various ways as described in, for example, Japanese Patent Application Laid-Open No. 9-131021, for example, a motor actuator serving as a driving source such as a drain valve of a washing machine or a shutter of a ventilation line. An example thereof is shown in FIG. 7 and described next.

The motor actuator is an AC synchronous motor (only the rotor 103 is described in FIG. 7), a box body composed of a case 101 and a cover 102, and a deceleration lubrication for reducing and transmitting the rotational force of the rotor 103 of the motor. The clutch mechanism 107 is assembled in the hot air balloon 104A, the output shaft 105, and the deceleration lubrication mechanism 104, and continuously cuts the deceleration lubrication mechanism 104 by turning on and off the power supply to the solenoid coil 106. Have

When the clutch mechanism 107 is turned on and the motor is rotated, the rotational force of the rotor 103 is transmitted to the output shaft 105 through the deceleration lubrication mechanism 104, and the output shaft 105 rotates. As a result, the pulley 108 fixed to the output shaft 105 rotates integrally with the output shaft 105 to wind the wire 109. In addition, a switch for stopping the rotor 103 is configured to cooperate with a predetermined rotation of the output shaft 105. That is, the switch is turned on and off by operating the switch piece by a cam (not shown) which rotates integrally with the output shaft 105.

In addition, since the power supply to the solenoid coil 106 is continued even when the driving of the motor is stopped by the operation of the switch in the state in which the wire 109 is wound to a predetermined position, the output shaft 105 and the motor 103 are decelerated and lubricating mechanism 104. Is connected via). Therefore, the wire 109 is fixed at the reeled position by the detent torque of the motor.

In this state, when the energization of the solenoid coil 106 is stopped and the clutch mechanism 107 is turned off, the wire 109 is free to the motor, and the wound by its own weight is released to the position before winding up. Will be returned. In this motor actuator, when the wire 109 returns, the rubber brake 110 assembled to the deceleration lubrication mechanism 104 is operated to adjust the speed of the return operation of the wire 109.

In the above-described motor actuator, by changing the configuration of the switch, the stop position of the wire 109 is made into two modes of the start position of the winding and the rewind position, or in addition to the three mode which makes it possible to stop at the intermediate position. The above mode can be achieved. In other words, if the clutch mechanism 107 is turned on when the motor stops driving, the wire 109 is fixed at the position, and the switch operating position is provided to have several stop positions of the wire 109. Can be.

In the conventional motor actuator described above, the clutch mechanism 107 using the on / off of the solenoid coil 106 is assembled in the deceleration lubrication mechanism 104, but the configuration of the clutch mechanism 107 will be described in detail again.

The clutch mechanism 107 has a rotating body 112 on which the flanger 111 which rides in accordance with the on-off of the solenoid coil 106, and the spring 113 which biases this rotating body 112 to the flanger 111 side. And the gear 114 which is arrange | positioned at the motor side as the position which overlaps with the rotating body 112 in the axial direction.

Then, when the solenoid coil 106 is turned on and the flanger 111 and the rotor 112 are pushed downward in FIG. 7 against the bias force of the spring 113, the groove 112 is formed in the gear 114. The rotary body 112 and the tooth 114 can be integrally rotated in the circumferential direction. On the contrary, when the solenoid coil 106 is off, the rotating body 112 is pushed upwards by the force of the spring 113, and the rotating body 112 and the tooth | gear 114 are separated. As a result, the rotor 112 is in a state where the connection with the motor side is broken. This state is a state where the pulley 108 mentioned above is free with respect to a motor, and the rotating body 112 rotates freely according to rotation of the pulley 108. As a result, the rubber brake 110 disposed on the rotor 112 also operates in accordance with the rotation of the rotor 112.

As described above, the conventional motor actuator incorporates the clutch mechanism 107 using the on / off of the solenoid coil 106 into the deceleration lubrication mechanism 104. Therefore, the various components constituting the solenoid coil 106 and the clutch mechanism 107 (a body or flanger fixing the solenoid coil 106 or the rotating body 112, the spring 113, the gear 114, etc.) Since the number of parts is required in the apparatus, the apparatus is large in size and complicated, and at the same time, the reliability of the apparatus operation becomes unstable.

In addition, in the conventional motor actuator, when the clutch mechanism 107 is turned off, the rotation of the deceleration lubrication heat 104 is controlled to suppress the shock caused by the operation during the return operation due to the weight of the wire 109 itself. The rubber brake 110 which slows down the operation of the 109 is provided. As a result, the number of parts increases further, resulting in a more complicated device.

It is an object of the present invention to simplify a device by reducing the number of parts and to provide a motor actuator capable of stabilizing the operation of a washing machine or a ventilation line.

1 is a longitudinal sectional view of a motor actuator of an embodiment of the present invention.

Figure 2 is a plan view of the cover and bracket of the motor actuator of Figure 1 removed.

3 is a plan view of the bracket attached to the motor actuator of FIG.

4 is a diagram illustrating a motor power supply circuit of the motor actuator of FIG. 1.

5 is a partial cross-sectional plan view of a driven mechanism including an operating member driven by the motor actuator of FIG.

6 is a view showing a modification of the motor actuator of the embodiment of the present invention, a plan view of a state in which the cover is removed.

7 is a partial cross-sectional exploded view showing an example of a conventional motor actuator.

In order to achieve this object, the present invention provides a motor and a motor actuator having a motor and an output shaft connected to an operation member while being driven by the motor, wherein the motor actuator operates the operation member by the driving force of the motor. By arranging a cam driven and a switch operated by the cam, and switching the magnitude of the voltage applied to the motor by switching the switch, the operation mode of the operating member is changed, and between the motor and the output shaft A deceleration lubrication mechanism is installed in the motor, and the motor rotates the output shaft through the deceleration lubrication mechanism, and the magnitude of the voltage applied to the motor corresponds to at least a return force in which the driving force of the motor acts on the operating member. The size and the force greater than this It is set to have a magnitude of the driving force to pull up the operation member, and the brake using the magnetoresistance that the rotor rotates through the deceleration lubrication mechanism for the return force acting on the operation member when the voltage to the motor is stopped. It is supposed to work.

Another invention is a motor actuator having a motor and an output shaft connected to an operation member while being rotated by the motor and operating the operation member by a driving force of the motor, the motor feeding circuit for supplying a voltage to the motor and the switch; The voltage divider acting as the switch is arranged, and the voltage applied to the motor increases in the non-operation state of the switch to operate the operating member, while the switch is operated to determine the operating member by passing the voltage applied to the motor through the voltage divider. I fix it to a position.

Another invention is provided with a return means for returning the operation member to a predetermined position in addition to the above-described motor actuators, while operating the operation member against the return force of the return means by the driving force of the motor when the switch is on. When the switch is off, power is supplied to the motor through the resistor to weaken the driving force of the motor.

In addition, in another invention, the resistance value is set so that the driving force of the motor driven by the applied voltage through the resistor in addition to each motor actuator described above is balanced with the return force of the return means for returning the operation member to the predetermined position.

In still another aspect of the present invention, in addition to the motor actuators described above, when the electric supply to the motor is cut off, the operation member is returned to the predetermined position by the return force of the return means.

In yet another invention, the motor is a DC motor in addition to the motor actuators described above.

According to still another aspect of the present invention, in addition to the above-described motor actuators, the switch is composed of a cam that rotates in coordination with the output shaft and a switch piece controlled by the cam.

According to the above-described motor actuator, when electric power is supplied to the motor, the rotational force of the motor is transmitted to the operating member, and for example, the drain valve of the washing machine is opened. At that time, the switch operates to switch the voltage applied to the motor. As a result, the operating mode of the operating member changes so far (for example, from winding up a wire to simply fixing). As described above, in the present invention, even if a clutch using a solenoid like the conventional apparatus is provided, the operating mode of the operating member can be changed in various ways by switching the magnitude of the voltage supplied to the motor, so that the conventional operation can be realized with a simple mechanical configuration. do.

Next, an embodiment of the motor actuator of the present invention will be described with reference to FIGS. 1 to 5. Moreover, this motor actuator 1 is for driving the drain valve of a washing machine.

The motor actuator 1 of the present invention does not have a clutch mechanism that continuously disconnects between the motor and the output shaft unlike the conventional one. The motor actuator 1 of the present invention is operated by switching the magnitude of the voltage applied to the DC motor 14 by switching on and off of the first and second switches 70a and 70b described later (the rod 87 described later). And the pulley 50 connected to the pulley 50, or the pulley 50 is fixed at the wound position.

Next, the configuration for realizing the operation will be described in detail. 1 to 3, the box 11 of the motor actuator 1 is covered by the case 11a and the cover 11b which is covered with the case 11a and fastened to the case 11a with the tapping screw 11c. Is formed. In this box 11, the DC motor 14 which becomes a motor of a drive source for operating the rod 87 is arrange | positioned like FIG. 5 mentioned later. The motor pinion 14b is press-fitted to the motor output shaft 14a of the DC motor 14.

In addition, the box 11 includes a deceleration lubrication mechanism 20 that decelerates and transmits the rotational driving force of the DC motor 14, and an output shaft 30 receiving the driving force of the DC motor 14 through the deceleration lubrication mechanism 20. Are arranged respectively. The deceleration lubrication mechanism 20 includes a first gear 21 engaged with the motor pinion 14b, a second gear 22 engaged with the first gear 21, and a second gear ( A third gear 23 engaged with 22). And the small tooth 23b of the 3rd gear 23 is meshed with the output gear 30a formed in the output shaft 30. As shown in FIG.

Moreover, in the box 11 shown in FIG. 1, the intermediate plate 15 is arrange | positioned above the case 11a at regular intervals with respect to the inner bottom face of the case 11a. And between the inner bottom face of the case 11a and the intermediate | middle plate 15, the shaft 22c, 23c supported by the both ends of the case 11a and the intermediate | middle plate 15 is arrange | positioned, respectively, These shafts 22c and 23c ), The second and third toothed portions 22, 23 are supported so as to rotate freely.

In addition, the first gear 21 has a larger diameter 21a on the upper side of the intermediate plate 15 in FIG. 1, and a normal small diameter tooth 21b long in the axial direction allows the intermediate plate 15 to penetrate. It is arrange | positioned in the box 11. The tooth 22a of the large diameter of the 2nd gear part 22 mentioned above is engaged with the lower part in the intermediate plate 15 of the tooth 21b of the 1st gear part 21 small diameter.

The output shaft 30 is provided with the above-described output gear 30a disposed below the intermediate plate 15 at the lower end of FIG. 1, and the upper end side thereof protrudes upward of the intermediate plate 15 and covers the cover ( 11b) protrudes upward. Then, the cam 40 is loosely fitted between the intermediate plate 15 and the cover 11b on the output shaft 30, and a pulley 50 for operating the rod 87 to be described later is integrally fitted thereon. You lose.

As shown in Fig. 2, the cam 40 has three parts: an outermost periphery 40a, an intermediate portion 40b serving as a first step portion, and an innermost portion 40c serving as a second step portion. At the position opposite to the outer circumferential surface of the cam 40, three switch pieces 71, 7 constituting the first and second switches 70a, 70b for switching the voltage applied to the DC motor 14, 73) is being deployed. In addition, in this embodiment, although several switches are made and it operates in three modes, you may make it operate by making two switches as one, or arranging several switches and making it into several modes.

The cam 40 rotates approximately 210 degrees from a state in which the bent portion 71a of the switch contact piece 71 is raised (initial state) from the middle position of the outermost circumference portion 40a to a portion on the side of the middle portion 40b slightly. As shown in Fig. 2, the bent portion 71a rotates to the state (final state) in which it is separated from the innermost peripheral portion 40c and vice versa.

These switch contact pieces 71, 72 and 73 are each configured such that the base side is fixed in the case 11a and the tip side is operated by the cam 40. As shown in FIG. When the switch contact piece 71 is lifted up against the outermost peripheral part 40a of the cam 40, the front end side of the switch contact piece 71 bends greatly in the outer circumferential direction, and the switch contact piece contacts the switch contact piece 72 at the same time. The switch contact piece 72 which is pushed outward by 71 is in contact with the switch contact piece 73 of another outer side. In this state, both the first switch 70a composed of the switch pieces 72 and 73 and the second switch 70b composed of the switch pieces 71 and 72 are turned on.

In the state where the front end side of the switch contact piece 71 faces away from the middle portion 40b of the cam 40, the tip warpage of the switch contact piece 71 and the switch contact piece 72 becomes small, and the central switch contact piece 72 is formed. And the switch contact piece 73 on the outside move away. As a result, the first switch 70a constituted by the switch pieces 72 and 73 is turned off. On the other hand, the second switch 70b continues to be in the on state.

When the first switch 70a is turned off, the application of the voltage to the DC motor 14 performed by the lead wires 16a and 16b as shown in FIG. 4 results in the resistance 17a being the first voltage divider having a predetermined resistance value. It is supposed to be done through. For this reason, the driving force for driving the DC motor 14 becomes "weak". At this time, the value of the resistor 17a is intended to take the wire 53 out of the pulley 50 by the driving force to wind up the pulley 50 of the DC motor 14 and the action of the drain valve mechanism 93 to be described later. The power to act is a balanced value. Accordingly, the operation member to be described later can be fixed at a predetermined position.

Then, the cam 40 is rotated again by switching the application of the voltage to the DC motor 14 performed by the lead wires 16a and 16b to the lead wires 16a and 16c. When the front end side faces away from the innermost periphery 40c of the cam 40, the switch contact piece 71 moves away from the switch contact piece 72, and the second switch 70b composed of the switch contact pieces 71 and 72 is turned off. At the same time, the first switch 70a is turned off.

When the second switch 70b is turned off, the voltage is applied to the DC motor 14 as shown in FIG. 4 through the resistor 17b serving as the second voltage divider resistor having a predetermined resistance value. For this reason, the driving force for driving the DC motor 14 becomes "weak" again. At this time, the value of the resistance 17b is a value in which the driving force for winding up the pulley 50 of the DC motor 14 and the force for pulling out the wire 53 from the pulley 50 are balanced. In other words, the present embodiment is configured to repeat the pulling operation of the operating member and the fixing at the lowering position twice.

In addition, the motor actuator 1 of this embodiment stops the application of the voltage to the DC motor 14 under the control of an external control device after both the first and second switches 70a and 70b are turned off. . The wire 53 is pulled out from the pulley 50 by the return force of the spring 89 as a return means for returning the rod 87 (refer FIG. 5) by the stop of this electric power supply.

The rotational force in the reverse direction from the driving of the pulley 50 is reversed from the output shaft 30 by the third gear 23, the second gear 22, the first gear 21, and the motor output shaft 14a. Is passed to. For this reason, the brake force using the magnetic resistance which generate | occur | produces in the DC motor 14 with respect to the rotor (not shown) which rotates with the motor output shaft 14a acts, and the return operation of the rod 87 is controlled by the rotor for speed control. It will move slowly.

Lead wires 16a, 16b and 16c serving as power supply units to the DC motor 14 are provided to protrude outwardly from the case 11a, and these lead wires 16a, 16b and 16c are external power sources. The power supply and stop to the DC motor 14 are controlled by being connected to the control device which also serves as the control unit. In addition, in the case 11a, as shown in FIG. 4, resistors 17a and 17b serving as first and second voltage divider resistors that are arranged in parallel with the first and second switches 70a and 70b, respectively, are provided. have.

In addition, as shown in FIG. 2, the switch contact piece 71 includes a bent part 71a contacting the cam 40, a contact part 71b contacting the switch contact 72, a lead wire 16c drawn out, and a resistor. It has the connection part 71c connected to (17a) (17b). Moreover, the switch contact piece 72 is comprised from the contact part 72a which contacts the switch contact pieces 71 and 73, and the connection part 72b connected to the DC motor 14 and the resistor 17b. Moreover, the switch contact piece 73 is comprised from the contact part 73a which contact | connects the switch contact piece 72, the lead wire 16b drawn out to the exterior, and the connection part 73b connected to the resistor 17a.

In addition, the resistors 17a and 17b are placed and placed so as to be arranged in the opening 15a formed in the intermediate plate 15. The resistor 17a is connected to the connecting portion 71c of the switch contact piece 71 in which the upper end (end portion on the cover 11b side) is further disposed on the cam 40 side via a metal piece, and the lower end (on the case 11a side). End) is connected to a lead wire 16b for connecting to an external control device. On the other hand, the upper end of the resistor 17b is connected to a lead wire 16c for connecting to an external control device, and the lower end is connected to the DC motor 14 via a metal piece.

In addition, the connection relationship between the switch contacts 71, 72, 73, the resistors 17a, 17b, and the DC motor 14 is the same as that of the motor power supply circuit. One end of the DC motor 14 is connected to an external power supply by a lead wire 16a. The other end of the DC motor 14 is connected to the switch contact piece 72 and the resistor 17b. The resistor 17b is connected in parallel with the second switch portion 70b constituted by the switch contacts 72 and 71. When the second switch portion 70b is on, most of the power source is the second switch portion ( 70b), and hardly flows through this resistance 17b. The other end of the resistor 17b is connected with a lead wire 16c for connection to an external power source.

As shown in FIG. 4, one end of the resistor 17a is connected to the switch contact piece 73 which is foldable. The resistor 17a is connected in parallel with the first switch portion 70a constituted by the switch pieces 72 and 73, and the power is supplied by the lead wires 16a and 16b and the first switch portion ( When 70a) is on, little current flows, and only when it is off, current passes. The other end of the resistor 17a is connected to a lead wire 16b for connection with an external power source.

On the other hand, the pulley 50 connected to the distal end of the output shaft 30 is prevented from falling off by the stop spring 51 while the boss is fitted into the shaft hole of the cover 11b. In addition, a bracket 52 serving as a pulley cover for covering the pulley 50 is attached to the box 11. This bracket 52 is an attachment part to the other member of this apparatus.

One end of the wire 53 is connected to the pulley 50 by the stopper 53a. The other end of the wire 53 is connected to the rod 87 as an operating member in the drain valve mechanism 93 via the intermediate plate 81 and the connecting strip 88 as shown in FIG.

The casing 85 is provided with a water inlet 82 and a drain 84, and the end portion 85a of the bellows 85 is pressed against the inclined wall 83a of the casing 83 by the force of the spring 89. Is closed between the inlet port 82 and the drain port 84. That is, the spring 89 is a return means for returning the rod 87 as the operation member to a predetermined position (a position for closing the inlet 82 and the drain port 84).

On the other hand, when the wire 53 is wound around the pulley 50 by the rotational drive of the pulley 50 as shown in Figure 5, the rod 87 is pulled against the bias force of the spring 89 to the end of the bellows (85) ( 85a is separated from the inclined wall 83a of the casing 83, and the water introduced from the inlet port 82 is drained through the drain port 84.

In addition, although the above-mentioned embodiment is a suitable embodiment of this invention, it is not limited to this, A various change is possible in the range which does not deviate from the summary of this invention. For example, in the above-described embodiment, the rod 87 is operated by connecting the rod 87 as the operating member to the front end side of the wire 53 and winding the wire 53 with the pulley 50 to operate the rod 87. The mechanical mechanism for operating the member may be configured as shown in FIG.

That is, as shown in FIG. 6, a parting circumference cut out part of the circumferential direction on the output shaft 30 which is integrally rotated with the output gear 30a engaged with the third gear 23, which is the final end of the deceleration lubrication mechanism 20. (35) is arranged to rotate integrally. The rack 36 including the cutout gear 35 and the rack teeth 36a that can be engaged may be connected to the operation member instead of the wire 53 described above. In the configuration shown in Fig. 6, the cam 40, the first and second switches 70a and 70b, and other mechanical mechanisms and motor power supply circuits are the same as in the above-described embodiment.

In the configuration of FIG. 6 described above, the drive of the cutting gear 35 is continued without disconnection of the DC motor 14, so that the coupling between the rack teeth 36a and the cutting gear 35 is separated and operated. It is also possible for the operating member to return to its original position by the return force of the member. However, when such control is performed, the brake due to the magnetoresistance of the DC motor 14 does not operate, so when decelerating the return sound using the brake, the energization of the DC motor 14 is cut off as in the above-described embodiment. It is preferable to return the operating member to its original position.

In the above-described embodiment, the rotational position of the cam 40 is fixed by balancing the driving force of the "about" power of the DC motor 14 and the return force of the operation member. In other words, for example, the drive force of the "weak" of the DC motor 14 may be slightly stronger than the return force, so that the drive force of the DC motor 14 may be slowly rolled up compared to the case of the case of winding by the drive force of the "strong".

In addition, the pulley 50 once wound up may be slowly released by making the driving force of "about" weaker than the return force.

In addition, four or more switch contact pieces may be used, and three or more stepped parts may be provided accordingly. Alternatively, switch contacts may be arranged at two positions on both sides of the cam 40, or part of several switch contacts may be used for other functions.

The cam 40 may be returned by using a motor capable of forward and reverse rotation, instead of using a spring force such as the spring 89 of the drain valve mechanism 93, and energizing the motor again. The DC motor 14 may be a pulse motor, such as a stepping motor, instead of a normal DC motor, or an AC motor may be employed, such as a small AC synchronous motor.

As described above, in the motor actuator of the present invention, the operation mode of the operation member is changed by switching the magnitude of the voltage applied to the motor by switching the switch. Therefore, in the present invention, it is not necessary to provide a clutch using a solenoid as in the conventional apparatus, so that the apparatus can be simplified by reducing the number of parts.

In other words, by switching the switch, it is possible to perform various operations such as the pulling operation of the operating member, the fixing at the pulling position, or the pulling up or slowing down slowly. Therefore, when this motor actuator is used as a drain valve driving device of a washing machine or as a shutter driving device of an exhaust line, the operation can be various, and the device can cope with various modes.

If the DC motor is used as the driving source and the configuration is not provided with the clutch in the middle of the heating cycle, the supply of power to the DC motor is stopped so that the external force from the operating member side rotates the rotor of the DC motor. This makes it possible to apply an appropriate brake to the operation of the operating member, and when used in various devices, the device becomes a quiet device without impact sound or the like caused by the operation of the operating member. As a result, it is not necessary to include a rubber brake in the apparatus as in the conventional apparatus, so that the number of parts can be reduced. In addition, when the switch is composed of a cam that rotates in coordination with the output shaft and the switch contact piece controlled by the cam, the linkage between the switch and the cam can be assured further.

Claims (7)

A motor actuator having a motor and an output shaft connected to an operation member while being driven by the motor, wherein the motor actuator operates the operation member by a driving force of the motor. By disposing a cam driven by the motor and a switch operated by the cam, and changing the magnitude of the voltage applied to the motor by switching of the switch to change the operating mode of the operating member, A deceleration lubrication mechanism is installed between the motor and the output shaft, and the motor rotates the output shaft through the deceleration lubrication mechanism. The magnitude of the voltage applied to the motor is at least such that the driving force of the motor corresponds to the return force acting on the operation member, and the operation member can be maintained at a predetermined position and operated with a force greater than this. It is set to become the size which becomes the driving force to raise a member, And a brake using a magnetoresistance in which the rotor rotates through the deceleration lubrication mechanism with respect to a return force applied to the operation member when the voltage to the motor is stopped. A motor actuator having a motor and an output shaft connected to an operation member while being driven by the motor, wherein the motor actuator is operated by a driving force of the motor, the motor actuator comprising: a switch in a motor supply circuit for supplying voltage to the motor; The voltage divider resistor disposed by the switch is disposed, and the voltage applied to the motor increases in the non-operation state of the switch to operate the operating member, while the voltage is applied to the voltage divider resistor by operating the switch. The motor actuator according to claim 1, wherein the motor actuator is made small by means of fixing the fixing member to a predetermined position. The method according to claim 1 or 2, A return means for returning the operation member to a predetermined position, and when the switch is turned on, when the switch is turned off while operating the operation member against the return force of the return means by the driving force of the motor A motor actuator characterized in that the driving force of the motor is weakened by supplying electricity to the motor through a resistor. The method of claim 3, wherein And the resistance value is set such that the driving force of the motor driven by the applied voltage through the resistance is balanced with the return force of the return means for returning the operation member to the predetermined position. The method of claim 3, wherein And if the electric supply to the motor is cut off, returning the operating member to the predetermined position by a return force of the return means. The method according to claim 1 or 2, A motor actuator comprising the motor as a DC motor. The method according to claim 1 or 2, And the switch comprises a cam that rotates in coordination with the output shaft, and a switch contact piece controlled by the cam.