WO2016092632A1

WO2016092632A1 - Actuator

Info

Publication number: WO2016092632A1
Application number: PCT/JP2014/082542
Authority: WO
Inventors: 後藤　隆
Original assignee: 三菱電機株式会社
Priority date: 2014-12-09
Filing date: 2014-12-09
Publication date: 2016-06-16
Also published as: JPWO2016092632A1; JP6351755B2

Abstract

An actuator 100 is provided with a plate 27 that is disposed between a hollow motor chamber 32 that accommodates both a brushed motor 200 and a shaft 7 and a hollow sensor chamber 33 that communicates with the motor chamber 32 and accommodates a sensor 20 used to control the movement of the shaft 7. Blocking heat, noise, and the like, generated within the motor chamber 32 using the plate 27 makes it possible to enhance the detection accuracy of the sensor 20. Further, because merely adding the plate 27 makes it possible to block both heat and noise, an increase in the number of parts can be suppressed.

Description

Actuator

The present invention relates to an actuator that linearly moves or rotates a shaft by a driving force of a motor with a brush.

In recent years, actuators are increasingly used for control drive parts of automobiles as automobiles become more electrified. In general, an actuator using a motor with a brush that has a simple structure and is inexpensive is employed as an actuator for an automobile.

A typical brush motor has a stator composed of a cylindrical stator yoke and a magnet provided on the inner periphery of the stator yoke. A rotor is constituted by a core inserted through the stator yoke and a winding wound around the core. By energizing the windings from the power supply brush through the commutator that rotates integrally with the core, the direction of the current flowing in each winding is switched alternately according to the rotation of the commutator, so that the stator In contrast, the rotor rotates.

The driving system of the actuator for automobiles is classified into a direct acting type and a rotating type. The direct-acting actuator converts the rotary motion of the rotor into a linear motion by a screw mechanism or the like, and moves the shaft along the axial direction. The rotary actuator rotates the shaft by the rotational movement of the rotor. An automobile manufacturer selects an actuator of any drive system according to the mountability when the actuator is mounted on a car.

In addition, actuators have been developed that increase the accuracy of shaft position control by providing a sensor that detects the position of the shaft in the linear motion direction in a linear motion actuator. Similarly, in a rotary actuator, an actuator has been developed in which a sensor for detecting the rotation angle of the shaft is provided to improve the accuracy of shaft rotation control. As these sensors, for example, magnetic sensors provided on a substrate in an actuator are used.

Actuators used in automobile engine rooms are required to have high performance such as high heat resistance and long life. For example, an actuator used for a purpose of holding the valve opening at a constant opening or a purpose of holding the shaft at a predetermined position must always supply power to the rotor windings to maintain the thrust of the actuator. For this reason, especially when the operation frequency is high, there is a concern about the influence of the self-heating of the rotor.

The influence of the self-heating of the rotor is serious for the motor, and causes a decrease in performance such as a decrease in thrust and a decrease in life. The most concerned problem is that electronic parts such as sensors provided in the motor are damaged and the motor cannot be driven or controlled. On the other hand, the electric motor of Patent Document 1 dissipates heat generated inside the motor to the outside of the motor by attaching a heat radiation fin to the housing of the motor.

In addition, as a problem peculiar to a motor with a brush, there is a problem that a sensor provided in the motor malfunctions due to radiation noise (so-called “spark noise”) generated when a commutator piece energized from a brush is switched. is there. On the other hand, the electric motor of Patent Document 2 reduces the influence of noise on the sensor by arranging circuit elements such as capacitors, varistors, and choke coils on a substrate inside the motor.

JP 2009-171734 A JP 2008-35626 A

The electric motor of Patent Document 1 dissipates heat generated inside the motor to the outside of the motor by attaching a heat radiation fin to the motor casing. However, when mounted on a portion where air flow is generated inside the vehicle, the air flow is inhibited by the radiating fins, so that there is a problem that the degree of freedom of the mounting portion is lowered. Further, in the configuration in which the heat dissipating fins are simply provided, there is a problem that the influence of the spark noise generated between the commutator and the brush cannot be reduced.

The electric motor of Patent Document 2 reduces the influence of noise by arranging circuit elements such as capacitors, varistors, and choke coils on a substrate inside the motor. However, there is a problem that the number of parts increases due to these circuit elements, and the cost of the entire electric motor increases. Further, in the configuration in which circuit elements are simply added, there is a problem that the influence of the heat generated by the rotor on the sensor or the like cannot be reduced.

The present invention has been made to solve the above-described problems, and reduces the influence of the heat generated by the rotor and the spark noise generated between the commutator and the brush on the sensor while suppressing an increase in the number of components. An object of the present invention is to provide an actuator using a brushed motor.

The actuator of the present invention is an actuator that linearly rotates or rotates the shaft by the driving force of the brushed motor, communicates with the motor with the brush and the hollow motor chamber and the motor chamber, and moves the shaft. It comprises a plate arranged between a hollow sensor chamber containing a sensor used for control.

In the actuator of the present invention, since the plate is provided between the motor chamber and the sensor chamber, it is possible to shield the heat generated by the rotor and the spark noise generated between the commutator and the brush, thereby reducing the influence on the sensor. Moreover, since both heat generation and noise can be cut off simply by adding a plate, an increase in the number of parts can be suppressed.

It is sectional drawing of the actuator of Embodiment 1 of this invention. It is explanatory drawing which shows the example of the magnetic field which generate | occur | produced in the motor chamber of the actuator of Embodiment 1 of this invention. It is explanatory drawing which shows the example of the spark and radiation noise which generate | occur | produced in the motor chamber of the actuator of Embodiment 1 of this invention. It is explanatory drawing which shows the example of the heat | fever which generate | occur | produced in the motor chamber of the actuator of Embodiment 1 of this invention. Fig.5 (a) is explanatory drawing which shows the inclination angle of the sensor shaft in the actuator which does not have a plate and a 2nd holding | maintenance part. FIG.5 (b) is explanatory drawing which shows the inclination angle of the sensor shaft in the actuator of Embodiment 1 of this invention. It is sectional drawing of the cover of Embodiment 1 of this invention. It is sectional drawing of the other cover of Embodiment 1 of this invention. It is sectional drawing of the actuator of Embodiment 2 of this invention. It is explanatory drawing which shows the example of the heat | fever which generate | occur | produced in the motor chamber of the actuator of Embodiment 2 of this invention. It is sectional drawing of the actuator of Embodiment 3 of this invention. It is explanatory drawing which shows the example of the high frequency noise which the electric wire adjacently installed in the actuator of Embodiment 3 of this invention generate | occur | produced. It is sectional drawing of the other actuator of Embodiment 3 of this invention. It is a perspective view of the other plate, the 2nd holding | maintenance part, and electromagnetic shielding part of Embodiment 3 of this invention.

Hereinafter, in order to explain the present invention in more detail, modes for carrying out the present invention will be described with reference to the accompanying drawings.
Embodiment 1 FIG.
FIG. 1 shows a cross-sectional view of the actuator of the first embodiment. The actuator 100 according to the first embodiment will be described with reference to FIG.

The core 1 is made of, for example, a laminated steel plate. The core 1 has a cylindrical yoke and a plurality of teeth protruding from the outer periphery of the yoke. In the illustrated example, when the laminated steel plate is resin-molded, the bobbin is integrally formed, and the winding 2 is wound around the bobbin. A rotor 3 is constituted by the core 1 and the winding 2.

The pipe 4 is fixed to the hollow portion of the core 1 and is rotated integrally with the core 1. A shaft 7 is inserted along the axis of the pipe 4. A screw mechanism 8 is provided between the inner periphery of the pipe 4 and the outer periphery of the shaft 7, and the shaft 7 moves linearly along the axial direction in accordance with the rotation of the rotor 3. Yes.

One end 71 of the shaft 7 protrudes from one end of the pipe 4. A convex stopper 9 that restricts the linear movement of the shaft 7 by contacting the screw mechanism 8 and the housing 11 is formed on the outer peripheral portion in the vicinity of the one end portion 71 of the shaft 7.

A commutator 10 is fixed to the other end of the pipe 4. The commutator 10 includes a cylindrical insulator and a plurality of commutator pieces installed on the side peripheral surface of the insulator. Each commutator piece is electrically connected to at least one winding 2.

The rotor 3 is accommodated in a bottomed cylindrical housing 11. A hole 111 is formed in the center of the bottom of the housing 11, and one end 71 of the shaft 7 passes therethrough. A bearing 12 is interposed between the inner periphery of the housing 11 and one end of the pipe 4, and a bearing 13 is interposed between the inner periphery of the housing 11 and the other end of the rotor 3. . The rotor 3 and the pipe 4 are rotatably supported with respect to the housing 11 by the

bearings

12 and 13.

A magnet 14 facing the rotor 3 is fixed to the inner periphery of the housing 11. A ring 15 is provided between the magnet 14 and the bearing 12.

The opening of the housing 11 is covered with a cover 16. The cover 16 has a bottomed cylindrical main body 161 and a flange 162 formed in the opening of the main body 161, and the flange 162 is fixed to the opening of the housing 11.

A plurality of brushes 17 facing the commutator 10 are provided on the collar portion 162 of the cover 16. Each brush 17 is pressed against the commutator 10 by a spring 18. The commutator 10 is rotated in accordance with the rotation of the rotor 3, and the commutator pieces in contact with the brushes 17 are switched.

A substrate 19 is provided on the bottom of the main body 161 of the cover 16. A sensor 20 is provided on the substrate 19. The sensor 20 is constituted by a magnetic sensor, for example. Connector terminals 21 are formed on the outer peripheral portion of the main body 161 of the cover 16. The connector terminal 21 is provided with a conductor 22 electrically connected to the brush 17 and the substrate 19.

A cylindrical first holding portion 23 is formed at the center of the bottom portion of the main body portion 161 of the cover 16. A sensor shaft 24 is inserted through the first holding part 23. The sensor shaft 24 is pressed against the shaft 7 by a spring 25, and moves linearly integrally with the shaft 7 in a state where the tip end portion of the sensor shaft 24 is in contact with the other end portion 72 of the shaft 7. .

A sensor magnet 26 is provided on the sensor shaft 24 so as to move directly with the sensor shaft 24. The sensor magnet 26 is a target of detection by the sensor 20, and the sensor 20 detects the magnetic flux density formed by the sensor magnet 26 and the direction of the magnetic flux.

Hereinafter, in the present application, among the hollow portions formed by the housing 11 and the cover 16, the hollow portions accommodating the main components of the brushed motor 200 such as the rotor 3, the commutator 10 and the brush 17 and the shaft 7 are referred to as “motor chamber”. " In addition, a hollow portion that accommodates the substrate 19, the sensor 20, and the sensor shaft 24 is referred to as a “sensor chamber”. That is, the motor chamber 32 and the sensor chamber 33 are constituted by an integral hollow portion, and communicate with each other in a state where a plate 27 described later is not provided.

A plate 27 is provided between the commutator 10 and the sensor 20. The plate 27 is made of, for example, a magnetic material. The plate 27 has a circular shape whose diameter is larger than the inner diameter of the main body portion 161 of the cover 16, and the peripheral end portion of the plate 27 is integrated with the side wall portion of the main body portion 161 by insert molding. That is, in the example of FIG. 1, the plate 27 is provided so as to divide the integral hollow portion into the motor chamber 32 and the sensor chamber 33, and separates the motor chamber 32 and the sensor chamber 33 without a gap.

A hole 271 is formed in the center of the plate 27, and the sensor shaft 24 penetrates from the sensor chamber 33 side to the motor chamber 32 side. The edge portion of the hole 271 has a shape protruding in a cylindrical shape, thereby forming a second holding portion 28 that holds the sensor shaft 24.

The rotor 3, pipe 4, commutator 10, housing 11,

bearings

12 and 13, magnet 14, ring 15, cover 16, brush 17, spring 18, connector terminal 21, and conductor 22 constitute a brushed motor 200. . The actuator 100 includes the motor 200 with brush, the shaft 7, the screw mechanism portion 8, the substrate 19, the sensor 20, the first holding portion 23, the sensor shaft 24, the spring 25, the sensor magnet 26, the plate 27, and the second holding portion 28. Has been.

Next, the operation of the actuator 100 will be described.
When a power supply unit (not shown) applies a voltage to the conductor 22 of the connector terminal 21, a current flows from the conductor 22 to the commutator piece of the commutator 10 via the brush 17, and the winding 2 is energized. When the winding 2 is energized, a magnetic field is generated around the winding 2, and the core 1 is excited to form a magnetic pole.

The excited core 1 is attracted to the magnet 14 disposed on the inner periphery of the housing 11, and the rotor 3 rotates. Thereafter, the commutator 10 also rotates in conjunction with the rotation of the rotor 3, so that the direction of the current flowing through the individual windings 2 is switched, the magnetic poles of the core 1 are switched, and the rotor 3 continues to rotate.

At this time, one end portion 71 of the shaft 7 is pushed out of the housing 11 by the screw mechanism portion 8 according to the rotation of the rotor 3. On the other hand, by reversing the direction of the current supplied from the brush 17 to the commutator 10, the rotation direction of the rotor 3 is reversed, and the one end portion 71 of the shaft 7 is drawn into the housing 11. Thus, the shaft 7 moves linearly according to the rotation of the rotor 3.

Also, the sensor 20 detects the magnetic flux density formed by the sensor magnet 26 and the direction of the magnetic flux. A control unit (not shown) detects the position of the shaft 7 in the axial direction using the magnetic flux density detected by the sensor 20 and the direction of the magnetic flux. The control unit controls the movement of the shaft 7 by controlling the current supplied from the brush 17 to the rotor 3, and controls the amount of projection of the shaft 7 from the housing 11.

Next, the effects of the plate 27 and the second holding portion 28 will be described with reference to FIGS.
FIG. 2 shows an example of the magnetic field I generated by exciting the core 1. As shown in FIG. 2, since the plate 27 blocks the magnetic field I generated in the motor chamber 32, it is possible to prevent the magnetic field I from affecting the operation of the sensor 20 in the sensor chamber 33.

FIG. 3 shows an example of the spark II generated when the commutator piece in contact with the brush 17 is switched and the radiation noise III generated by the spark II. As shown in FIG. 3, since the radiation noise III generated in the motor chamber 32 is blocked by the plate 27, the radiation noise III can be prevented from affecting the operation of the sensor 20 in the sensor chamber 33.

FIG. 4 shows an example of heat IV generated in the motor chamber 32. The heat IV includes, for example, heat generated by a spark between the brush 17 and the commutator piece, heat generated by energizing the winding 2, heat generated by mechanical loss of the bearing 13, and magnetic loss of the core 1. And heat generated by. As shown in FIG. 4, the movement of the heat IV from the motor chamber 32 to the sensor chamber 33 is blocked by the plate 27 absorbing the heat IV generated in the motor chamber 32. Thereby, the temperature rise of the sensor 20 can be suppressed and deterioration of sensing sensitivity due to the temperature rise can be suppressed.

FIG. 5B shows the maximum value θ2 of the tilt angle of the sensor shaft 24 in the actuator 100 of the first embodiment. FIG. 5A shows the maximum value θ1 of the tilt angle of the sensor shaft 24 in the actuator that does not have the second holding portion 28 as a comparison object of FIG.

The actuator not having the second holding portion 28 holds the sensor shaft 24 only by the first holding portion 23 provided on the cover 16. On the other hand, the actuator 100 according to the first embodiment holds the sensor shaft 24 at two locations, the first holding portion 23 provided on the cover 16 and the second holding portion 28 provided on the plate 27. As a result, the actuator 100 of the first embodiment has the maximum inclination angle θ2 of the sensor shaft 24 with respect to the linear movement direction of the shaft 7 smaller than the maximum inclination angle θ1 of the actuator that does not have the second holding portion 28. can do. As a result, the fluctuation range of the magnetic pole direction of the sensor magnet 26 with respect to the sensor 20 can be reduced, and the detection accuracy and linearity of the position of the shaft 7 in the linear motion direction using the sensor 20 can be improved.

In addition, the shape and structure of the main components of the brushed motor 200 such as the rotor 3, the commutator 10, and the brush 17 are not limited to the shape and structure shown in FIG. Any member having any shape and structure may be used as long as it is a member constituting a general brush motor. Further, the magnet 14 is not limited to a permanent magnet, but may be an electromagnet using a coil or the like.

Further, the shapes of the housing 11 and the cover 16 are not limited to the shapes shown in FIG. Any shape may be used as long as it has an integral hollow portion that constitutes a motor chamber containing a rotor, a commutator, a brush, and the like of a motor with a brush and a sensor chamber containing a sensor.

Further, the shape of the plate 27 is not limited to the shape shown in FIG.
As shown in FIG. 1, when the plate 27 has a circular shape whose diameter is larger than the inner diameter of the main body portion 161 of the cover 16 and the peripheral end portion of the plate 27 is integrated with the side wall portion of the main body portion 161, The motor chamber 32 and the sensor chamber 33 are separated from each other without a gap. Further, the hole 271 provided at the center of the plate 27 is closed by the sensor shaft 24. Thereby, the shielding effect of the magnetic field I, the radiation noise III, and the heat IV can be maximized.
On the other hand, a through hole different from the hole 271 is further drilled in the plate 27, or the plate 27 has a non-circular shape such as an ellipse or a polygon, and a gap is provided between the peripheral end portion and the side wall portion of the main body portion 161. In this case, it is possible to reduce the weight of the actuator 100 by reducing the weight of the plate 27 while having a certain blocking effect.

The actuator 100 may be a rotary actuator in which the shaft 7 is fixed to the pipe 4 without the screw mechanism portion 8 and the shaft 7 and the sensor shaft 24 are rotated according to the rotation of the rotor 3. In this case, the sensor 20 may detect the rotation angle of the sensor shaft 24, and the control unit may calculate the rotation speed of the shaft 7 using this rotation angle and control the movement of the shaft 7.

Further, the material of the plate 27 is not limited to a magnetic material. Even the plate 27 made of a non-magnetic metal such as copper or aluminum can block radiation noise III and heat IV. However, since the magnetic field I can be cut off by configuring the plate 27 with a magnetic material, it is more preferable to configure the plate 27 with a magnetic material.

Further, the cover 16 may be a combination of the first cover member A and the second cover member B as shown in FIG. In this case, first, the substrate 19 and the sensor 20 are mounted on the first cover member A in which the conductor 22 is insert-molded. Further, the second cover member B in which the plate 27 is insert-molded is manufactured separately from the first cover member A. Next, the conductor 22 protruding from the first cover member A is inserted into the hole 163 formed in the second cover member B, and the first cover member A and the second cover member B are combined. Finally, the cover 16 provided with the substrate 19, the sensor 20, the conductor 22, and the plate 27 is manufactured by bonding the joint portion between the first cover member A and the second cover member B.

Alternatively, after the substrate 19 and the sensor 20 are mounted on the cover 16 in which the conductor 22 is insert-molded, the plate 27 may be inserted into the cover 16 from the opening of the cover 16. In this case, as shown in FIG. 7, a ring-shaped fitting member 29 having a recess into which the peripheral end portion of the plate 27 is fitted may be insert-molded on the side wall portion of the main body portion 161 of the cover 16. The fitting member 29 is also preferably made of a magnetic material similar to the plate 27.

As described above, the actuator 100 according to the first embodiment communicates with the motor chamber 32 and the hollow motor chamber 32 that houses the rotor 3, the commutator 10, and the brush 17 of the brushed motor 200. A plate 27 is provided between the sensor chamber 33 and the hollow sensor chamber 33 that houses the sensor 20 used for control.
By providing the plate 27 between the motor chamber 32 and the sensor chamber 33, the radiation noise III generated by the spark II between the brush 17 and the commutator piece of the commutator 10 is prevented from affecting the operation of the sensor 20. be able to. Further, it is possible to prevent the heat IV generated in the motor chamber 32 from affecting the operation of the sensor 20. As a result, the detection accuracy of the sensor 20 can be improved.
Furthermore, since both the radiation noise III and the heat IV can be blocked only by adding the plate 27 to the actuator, an increase in the number of parts can be suppressed.

The actuator 100 is housed in the sensor chamber 33, and is provided on the sensor shaft 24 and the sensor shaft 24 that abuts on the other end 72 of the shaft 7 housed in the motor chamber 32 and moves linearly or integrally. And a sensor magnet 26 serving as a target detected by the sensor 20. The plate 27 has a hole 271 that allows the sensor shaft 24 to pass from the sensor chamber 33 side to the motor chamber 32 side, and a second holding portion 28 that holds the sensor shaft 24 in a shape in which an edge portion of the hole 271 protrudes in a cylindrical shape. And have.
By holding the sensor shaft 24 at two locations of the first holding portion 23 of the cover 16 and the second holding portion 28 of the plate 27, the maximum value θ2 of the inclination angle of the sensor shaft 24 with respect to the axial direction of the shaft 7 is small. Thus, the change in the direction of the magnetic flux of the sensor magnet 26 due to the inclination of the sensor shaft 24 can be suppressed. As a result, the detection accuracy of the sensor 20 can be further improved.

The plate 27 has a shape that separates the motor chamber 32 and the sensor chamber 33 without any gap. Thereby, the interruption | blocking effect by the plate 27 can be heightened to the maximum.

The plate 27 is made of a magnetic material. Thereby, in addition to the radiation noise III and the heat IV, it is possible to prevent the magnetic field I generated by exciting the rotor 3 from affecting the operation of the sensor 20.

Embodiment 2. FIG.
FIG. 8 shows a cross-sectional view of the actuator of the second embodiment. With reference to FIG. 8, the actuator 101 in which the heat radiating portion 30 is formed by the end portion of the plate 27 will be described. In FIG. 8, the same components as those of the actuator 100 of the first embodiment shown in FIG.

The end of the plate 27 penetrates the cover 16 and protrudes to the outside of the actuator 101 to form a heat radiating part 30. The plate 27 having the heat radiating portion 30 is insert-molded on the side wall portion of the main body portion 161 of the cover 16. Although the size of the heat radiating portion 30 is not limited, it is more preferable that the length L1 between the center portion of the plate 27 and the tip end portion of the heat radiating portion 30 is longer than the radius L2 of the outer diameter of the housing 11.

Next, the effect of the heat dissipation part 30 will be described with reference to FIG.
FIG. 9 shows an example of heat IV generated in the motor chamber 32. The heat IV includes, for example, heat generated by a spark between the brush 17 and the commutator piece of the commutator 10, heat generated by energizing the winding 2, and heat generated by mechanical loss of the bearing 13. The heat generated by the magnetic loss of the core 1 is included. As shown in FIG. 9, the plate IV absorbs heat IV generated in the motor chamber 32, and the absorbed heat is radiated from the heat radiating unit 30 to the outside of the actuator 101. Thereby, the temperature rise of the sensor 20 can be further suppressed, and the deterioration of the sensing sensitivity due to the temperature rise can be further suppressed.

At this time, the length L1 of the heat radiating portion 30 is made longer than the radius L2 of the housing, thereby blocking the propagation of the magnetic field generated in the motor chamber 32 around the outside of the housing 11 to the motor chamber 32. Can do. As a result, this sneak magnetic field can be prevented from affecting the operation of the sensor 20, and the detection accuracy of the sensor 20 can be further improved.

As described above, the actuator 101 according to the second embodiment forms the heat radiating portion 30 by projecting the end portion of the plate 27 to the outside of the actuator 101. By radiating the heat IV absorbed by the plate 27 from the heat radiating unit 30 to the outside of the actuator 101, the temperature rise of the sensor 20 can be further suppressed, and the detection accuracy of the sensor 20 can be further improved.

In addition, the shape of the heat radiating part 30 is not limited to the shape shown in FIG. Any shape that penetrates the cover 16 and protrudes to the outside of the actuator 101 may be used.

Embodiment 3 FIG.
FIG. 10 shows a cross-sectional view of the actuator of the third embodiment. With reference to FIG. 10, the actuator 102 in which the electromagnetic shield portion 31 is provided on the plate 27 will be described. In FIG. 10, the same components as those of the actuator 100 according to the first embodiment shown in FIG.

A cylindrical electromagnetic shield portion 31 along the side wall portion of the main body portion 161 of the cover 16 is formed on the peripheral end portion of the plate 27. That is, the electromagnetic shield portion 31 has a shape along the wall portion of the sensor chamber 33 that houses the sensor 20.

Next, the effect of the electromagnetic shield part 31 will be described with reference to FIG.
When the actuator 102 is installed in an engine room of an automobile, the electric wire C is provided next to the outside of the actuator 102, and a high-frequency current may flow through the electric wire C. The actuator 102 according to the third embodiment blocks the high-frequency noise V radiated from the electric wire C by the electromagnetic shield unit 31, so that the external high-frequency noise V affects the operation of the sensor 20 in the sensor chamber 33. Can be prevented.

As described above, in the actuator 102 according to the third embodiment, the plate 27 has the electromagnetic shield portion 31 having a shape along the wall portion of the sensor chamber 33. Since the electromagnetic shield unit 31 blocks the external high-frequency noise V, it is possible to prevent the high-frequency noise V from affecting the operation of the sensor 20. As a result, the detection accuracy of the sensor 20 can be further improved.

The electromagnetic shield part 31 may be provided along the inner peripheral part of the side wall part of the body part 161 of the cover 16 as shown in FIG. 11, or embedded in the side wall part as shown in FIG. It may be what was done.

Further, as shown in the perspective view of FIG. 13, the electromagnetic shield part 31 is formed as a separate member from the plate 27, and then the claw part 272 of the plate 27 and the claw part 311 of the electromagnetic shield part 31 are welded. And may be integrated with the plate 27.

In the present invention, within the scope of the invention, free combinations of the respective embodiments, modifications of arbitrary components of the respective embodiments, or omission of arbitrary components of the respective embodiments are possible. .

In the actuator of the present invention, since the plate is provided between the motor chamber and the sensor chamber, it is possible to reduce the influence of the heat generated by the rotor and the spark noise generated between the commutator and the brush on the sensor while suppressing an increase in the number of components. It is suitable for an actuator for automobiles used for supercharging pressure control of an engine or opening degree control of a valve.

1 core, 2 winding, 3 rotor, 4 pipe, 7 shaft, 8 screw mechanism, 9 stopper, 10 commutator, 11 housing, 12, 13 bearing, 14 magnet, 15 ring, 16 cover, 17 brush, 18 spring , 19 substrate, 20 sensor, 21 connector terminal, 22 conductor, 23 first holding part, 24 sensor shaft, 25 spring, 26 sensor magnet, 27 plate, 28 second holding part, 29 fitting member, 30 heat dissipation part, 31 Electromagnetic shield part, 32 motor room, 33 sensor room, 71 one end part, 72 other end part, 100, 101, 102 actuator, 111 hole, 161 body part, 162 collar part, 163 hole, 200 brush motor, 271 hole, 272 nails, 311 nails.

Claims

In an actuator that moves or rotates the shaft directly with the driving force of a motor with a brush,
A plate disposed between the motor with brush and a hollow motor chamber accommodating the shaft, and a hollow sensor chamber communicating with the motor chamber and accommodating a sensor used for controlling the movement of the shaft. An actuator characterized by.
A sensor shaft that is housed in the sensor chamber and abuts on one end of the shaft and linearly moves or rotates integrally;
A sensor magnet provided on the sensor shaft and serving as a target to be detected by the sensor;
The plate has a hole through which the sensor shaft passes from the sensor chamber side to the motor chamber side, and a holding portion that holds the sensor shaft in a shape in which an edge of the hole protrudes in a cylindrical shape. The actuator according to claim 1.
2. The actuator according to claim 1, wherein the plate has a shape separating the motor chamber and the sensor chamber without a gap.
2. The actuator according to claim 1, wherein the plate is made of a magnetic material.
The actuator according to claim 1, wherein an end portion of the plate protrudes outside the actuator to form a heat radiating portion.
2. The actuator according to claim 1, wherein the plate has an electromagnetic shield part shaped along the wall part of the sensor chamber.