WO2019030856A1

WO2019030856A1 - In-vehicle actuator

Info

Publication number: WO2019030856A1
Application number: PCT/JP2017/028933
Authority: WO
Inventors: 將敏春名
Original assignee: 三菱電機株式会社
Priority date: 2017-08-09
Filing date: 2017-08-09
Publication date: 2019-02-14
Also published as: JP6837559B2; JPWO2019030856A1

Abstract

A rotary actuator (1) is provided with: a motor (4) having a hollow motor shaft (5); an output shaft (2), which penetrates the inside of the motor shaft (5), and which has both end sections that are protruding from the motor shaft (5); a speed change mechanism (20), which is disposed on the side of one end section of the output shaft (2), said one end section protruding from the motor shaft (5), and which transmits rotational force of the motor shaft (5) to the output shaft (2); and a position sensor (30), which is disposed on the side of the other end section of the output shaft (2), said the other end section protruding from the motor shaft (4), and which detects the rotation angle of the output shaft (2).

Description

Automotive actuator

The present invention relates to a rotational output type in-vehicle actuator.

The rotary output type actuator (hereinafter referred to as a rotary actuator) operates various devices by accelerating and decelerating the rotational torque of the motor to a desired torque and rotational speed by a gear transmission mechanism. In the conventional rotary actuator, the motor shaft and the output shaft are disposed in a parallel or orthogonal positional relationship via a spur gear or a worm reduction mechanism (see, for example, Patent Document 1).

JP 2005-180456 A

The allowable temperature limit of the rotary actuator is determined by the allowable temperature limit of the position sensor, which is an electronic component for detecting the rotation angle of the output shaft. When the conventional rotary actuator as described above is mounted on a vehicle, the position sensor is located close to the heat source of the turbocharger due to the structure of the rotary actuator, so it can be used until the heat resistant temperature is reached There was a problem that time was short.

Further, since the output shaft in the conventional rotary actuator is disposed at a position offset in parallel or orthogonal direction from the motor axis by the distance between the axes of the speed reduction mechanism, there is a problem that the rotary actuator is large.

The present invention has been made to solve the problems as described above, and its object is to improve the heat resistance of a rotary actuator and to miniaturize it.

The on-vehicle actuator according to the present invention includes a motor having a hollow motor shaft, an output shaft which penetrates the inside of the motor shaft and both ends project from the motor shaft, and an end portion of the output shaft which projects from the motor shaft. It has a transmission mechanism that is disposed and transmits the rotational force of the motor shaft to the output shaft, and a position sensor that is disposed on the other end side of the output shaft protruding from the motor shaft and detects the rotation angle of the output shaft. .

According to this invention, the heat resistance of the rotary actuator can be improved by arranging the position sensor with low heat resistance at a position far from the heat source. Further, the rotary actuator can be miniaturized by coaxially arranging the motor shaft and the output shaft.

FIG. 1 is a cross-sectional view showing a configuration example of a rotary actuator according to Embodiment 1. It is a reference example for helping understanding of the rotary actuator according to the first embodiment, and is a cross-sectional view showing an example in which the motor shaft and the output shaft are arranged in parallel. It is a reference example for helping understanding of the rotary actuator according to the first embodiment, and is a view showing a positional relationship between a heat source and a position sensor.

Hereinafter, in order to explain the present invention in more detail, a mode for carrying out the present invention will be described according to the attached drawings.
Embodiment 1
FIG. 1 is a cross-sectional view showing a configuration example of the rotary actuator 1 according to the first embodiment. The rotary actuator 1 is for rotating the lever 3 connected to the output shaft 2. A variable blade (VG), an exhaust gas recirculation (EGR) valve, a waste gate (WG) valve or the like (not shown) of the turbocharger is connected to the end of the lever 3 and these are operated by the rotary actuator 1.

First, the configuration of the rotary actuator 1 will be described.
The motor 4 is a drive source that rotates the motor shaft 5. The motor 4 is a brushed DC motor including a motor shaft 5, a commutator 6, a brush 7, a coil 8, a magnet 9, and a yoke 10, in a motor housing 13 made of thermoplastic resin or thermosetting resin. Be coated. Inside the motor housing 13, two

bearings

11 and 12 are installed at both axial ends of the motor shaft 5, and the

bearings

11 and 12 rotatably support the motor shaft 5. The commutator 6, the coil 8 and the sun gear 21 of the transmission mechanism 20 are fixed to the outer peripheral surface of the motor shaft 5. A brush 7 is installed on the outer peripheral side of the commutator 6 in the motor housing 13. The magnet 9 and the yoke 10 are installed on the outer peripheral side of the coil 8 in the motor housing 13. The motor 4 is not limited to the brushed DC motor, and may be any motor that rotates the motor shaft 5.

The motor shaft 5 has a hollow structure, and the output shaft 2 passes through the inside of the motor shaft 5. A space may be provided between the motor shaft 5 and the output shaft 2, and a bearing 14 may be installed. A sensor magnet 31 which is a target of the position sensor 30 is fixed to one end of the output shaft 2 which protrudes through the motor shaft 5. The carrier 22 of the transmission mechanism 20 is fixed to the other end of the output shaft 2 which protrudes through the motor shaft 5. The output shaft 2 and the motor shaft 5 are made of a nonmagnetic material such as stainless steel or a magnetic material such as steel. Although the output shaft 2 and the motor shaft 5 made of nonmagnetic materials are expensive, they have characteristics such as being less susceptible to noise generated in the motor 4 and the output of the rotary actuator 1 is large. Although the output shaft 2 and the motor shaft 5 made of magnetic material are inexpensive, the output of the rotary actuator 1 is small.

The transmission mechanism 20 is a transmission and reception mechanism that accelerates and decelerates the rotational force of the motor shaft 5 to increase or decrease torque and transmits the torque to the output shaft 2. The motor shaft 5 and the output shaft 2 can be coaxially arranged. The transmission mechanism 20 is a planetary reduction mechanism including a sun gear 21 made of steel or resin, a carrier 22, a planetary gear 23, and a ring gear 24, and is covered with a gear housing 25 made of aluminum or the like. The sun gear 21 is fixed to the motor shaft 5, and the carrier 22 is fixed to the output shaft 2. The carrier 22 rotatably supports a planetary gear 23 engaged with the sun gear 21 and the ring gear 24. The planetary gear 23 may be one or plural. The ring gear 24 is formed on the inner circumferential surface of the gear housing 25. Further, a bearing 26 is installed inside the gear housing 25, and the bearing 26 rotatably supports the output shaft 2. Note that the transmission mechanism 20 is not limited to the planetary reduction mechanism, and may be a hypocycloid mechanism or a wave gear mechanism as long as the motor shaft 5 and the output shaft 2 can be coaxially disposed.

One end side of the output shaft 2 which protrudes through the motor shaft 5 is covered with a sensor housing 32 made of thermoplastic resin, thermosetting resin or the like. The sensor magnet 31 is fixed to this one end. The sensor magnet 31 is coated with, for example, a resin, and the resin portion is fixed to one end of the output shaft 2 by press fitting, caulking, welding, or the like. A position sensor 30 is installed at a position opposite to the sensor magnet 31 in the sensor housing 32. The position sensor 30 detects the magnetic field of the sensor magnet 31 corresponding to the rotation angle of the output shaft 2. Since this position sensor 30 is an electronic component with low heat resistance such as a Hall IC (Integrated Circuit), as described above, the heat resistance temperature of the rotary actuator 1 is determined by the heat resistance temperature of the position sensor 30. . Further, a connector 33 is formed on the sensor housing 32.

Next, the operation of the rotary actuator 1 will be described.
When the connector 33 is energized, current flows to the brush 7, the commutator 6, and the coil 8, and the motor shaft 5 rotates with the coil 8. When the sun gear 21 rotates with the motor shaft 5, the planetary gear 23 meshing with the sun gear 21 revolves around the motor shaft 5 while rotating. The revolution rotation component of the planetary gear 23 is transmitted to the output shaft 2 by the carrier 22 and the lever 3 is actuated by the rotation of the output shaft 2. The position sensor 30 detects the magnetic field of the sensor magnet 31 rotating with the output shaft 2, converts it to the rotation angle of the output shaft 2, and externally outputs it via the connector 33. The rotation angle of the output shaft 2 detected by the position sensor 30 is used for feedback control, and the energization direction and application duty to the motor 4 are determined.

Next, the effect of the rotary actuator 1 will be described.
FIG. 2 is a reference example for helping understanding of the rotary actuator 1 according to the first embodiment, and is a cross-sectional view of the rotary actuator 100 in which the motor shaft 105 and the output shaft 102 are arranged in parallel. In the reference example, the transmission mechanism 120 including the pinion gear 121 and the

flat gears

122 and 123 is interposed between the motor shaft 105 of the motor 104 and the output shaft 102 to which the lever 103 is connected. The transmission mechanism 120 decelerates the rotational force of the motor shaft 105, increases torque, and transmits the torque to the output shaft 102. A position sensor 130 and a sensor magnet 131 for detecting the rotation angle of the output shaft 102 are disposed at the upper end of the output shaft 102.

FIG. 3 is a reference example for assisting the understanding of the rotary actuator 1 according to the first embodiment, and is a view showing the positional relationship between the heat source and the position sensor 130. As shown in FIG. The turbocharger 200 includes a compressor housing 201 incorporating a compressor wheel, and a turbine housing 202 incorporating a turbine wheel. As the turbine wheel rotates using exhaust gas, the compressor wheel coupled to the turbine wheel also rotates to compress engine intake air. The turbine housing 202 through which the exhaust gas flows has a high temperature and serves as a heat source. The position sensor 130 in the rotary actuator 100 installed in the turbocharger 200 is disposed on the tip end side of the output shaft 102 of the transmission mechanism 120 and is disposed at a position close to the lever 103 on the heat source side. Therefore, the position sensor 130 has a short usable time to reach the heat resistant allowable temperature in the actual use environment.

On the other hand, position sensor 30 of the first embodiment is disposed on the tip end side of output shaft 102 ahead of transmission mechanism 20 and motor 4 and is on the heat source side compared to position sensor 130 in rotary actuator 100. It is disposed at a position away from the lever 3. Therefore, when the rotary actuator 1 is installed at the same position as the rotary actuator 100 shown in FIG. 3, the usable time until the heat resistance allowable temperature of the position sensor 30 is reached in an actual use environment can be extended. The heat resistant allowable temperature of the rotary actuator 1 can be improved. Further, by improving the heat resistant allowable temperature of the rotary actuator 1, the current supplied to the motor 4 can be increased instead of prolonging the usable time, and the output of the rotary actuator 1 can be increased by increasing the current. Possible torque can be improved.

Further, since the rotary actuator 100 of the reference example shown in FIGS. 2 and 3 has a configuration in which the motor shaft 105 and the output shaft 102 are arranged in parallel, the projected area as viewed from the direction of arrow A in FIG. Is large and large.

On the other hand, since the rotary actuator 1 according to the first embodiment is a coaxial deceleration system using a planetary reduction mechanism or the like, the projection area as viewed in the direction of arrow A in FIG. 1 can be reduced. The actuator 1 can be miniaturized. Also, by increasing the number of planet gears 23 of the planetary reduction mechanism, the load on each planet gear 23 is reduced. Therefore, the material of each component such as the planetary gear 23 constituting the planetary reduction mechanism can be made low in strength and low in cost, and the heat treatment applied to each component can be made in low cost. Therefore, it is possible to reduce the cost of the rotary actuator 1 while improving the design freedom of the layout by miniaturizing the rotary actuator 1.

As described above, the rotary actuator 1 according to the first embodiment includes the motor 4 having the hollow motor shaft 5, and the output shaft 2 which penetrates the inside of the motor shaft 5 and whose both ends project from the motor shaft 5. A transmission mechanism 20 disposed on one end side of the output shaft 2 protruding from the motor shaft 5 and transmitting the rotational force of the motor shaft 5 to the output shaft, and the other end side of the output shaft 2 protruding from the motor shaft 5 And a position sensor 30 for detecting the rotation angle of the output shaft 2. With this configuration, since the position sensor 30 with low heat resistance can be disposed at a position far from the heat source, the heat resistance of the rotary actuator 1 can be improved. Further, since the motor shaft 5 and the output shaft 2 can be coaxially arranged, the rotary actuator 1 can be miniaturized.

The output shaft 2 of the first embodiment is a nonmagnetic material, and a sensor magnet 31 which is a target of the position sensor 30 is fixed to the other end of the output shaft 2 protruding from the motor shaft 5. By forming the vicinity of the sensor magnet 31 fixed portion of the output shaft 2 with a nonmagnetic material, the position sensor 30 is less susceptible to the noise generated by the motor 4 and the external magnetic field.

In the scope of the invention, modification of any component of the embodiment or omission of any component of the embodiment is possible within the scope of the invention.

Since the rotary actuator according to the present invention is improved in heat resistance, it is suitable for use in an on-vehicle actuator or the like installed near a turbocharger which is heated to a high temperature.

1,100 rotary actuators (vehicle-mounted actuators), 2,102 output shafts, 3,103 levers, 4,104 motors, 5,105 motor shafts, 6 commutators, 7 brushes, 8 coils, 9 magnets, 10 yokes, 11, 12 bearings, 13 motor housings, 14 bearings, 20, 120 transmission mechanisms, 21 sun gears, 22 carriers, 23 planet gears, 24 ring gears, 25 gear housings, 26 bearings, 30, 130 position sensors, 31, 131 sensors Magnet, 32 sensor housings, 33 connectors, 121 pinion gears, 122, 123 flat gears.

Claims

A motor having a hollow motor shaft,
An output shaft which penetrates the inside of the motor shaft and both ends project from the motor shaft;
A transmission mechanism disposed on one end side of the output shaft protruding from the motor shaft and transmitting the rotational force of the motor shaft to the output shaft;
And a position sensor disposed on the other end side of the output shaft protruding from the motor shaft and detecting a rotation angle of the output shaft.
The vehicle according to claim 1, wherein the output shaft is a nonmagnetic material, and a magnet serving as a target of the position sensor is fixed to the other end of the output shaft protruding from the motor shaft. Actuator.
The on-vehicle actuator according to claim 1, wherein a variable blade of a turbocharger is operated.
The on-vehicle actuator according to claim 1, wherein the exhaust gas recirculation valve of the turbocharger is operated.
The on-vehicle actuator according to claim 1, wherein the waste gate valve of the turbocharger is operated.
The on-vehicle actuator according to claim 1, wherein the transmission mechanism is a planetary reduction mechanism.