JPH04124865U - electric actuator - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a fail-safe mechanism in an "electric actuator" that does not cause damage to teeth. [Structure] A worm wheel 36 to which the output shaft 12 is attached at the center of rotation, and a thrust shaft 33 to which the worm 35 that meshes with the worm wheel 36 is attached and is movable along the thrust directions A and B of the worm 35.
And, this thrust shaft 33 is connected to the worm wheel 3.
A solenoid 34 is provided in the casing 25, which generates an electromagnetic force when energized to move the solenoid 6 and the worm 35 in the direction B in which they engage with each other. Further, a tension coil spring 37 that rotates the output shaft 12 in a direction in which the actuated member 26 (water valve) opens the waterway is attached between the rotary lever 14 and the vehicle body.

Description

[Detailed explanation of the idea]

0001

[Industrial application field]

This invention is used to improve electric actuators used in automobile air conditioners, etc. related.

0002

[Conventional technology]

Various doors such as air mix doors and intake doors of recent automotive air conditioners. Automotive door windows, etc. use electric actuators as their driving source.

0003 As shown in FIG. 4, a general electric actuator has upper and lower cases 10a, 10 In the casing 10 consisting of b, there is a motor M and a a deceleration mechanism 11 that rotates, an output shaft 12 rotated by the deceleration mechanism 11, and a motor M. A rotation control section 13 that performs rotation control is provided. Then, the rotation of the output shaft 12 is transmitted to the rotating lever 14 attached to the output shaft, and connected to this rotating lever 14. Various doors (not shown) are opened and closed via the control cable 15. ing.

0004 The speed reduction mechanism 11 includes a worm 16, a worm wheel 17, and spur gears 18, 1 9 etc., and the rotation control section 13 has a pattern shape formed on the wiring board 20. It has a circuit 21 and a brush 22 attached to the back surface of the spur gear 19. this When the brush 22 comes into sliding contact with the patterned circuit 21, depending on the position of the brush 22, When the power to motor M stops, continues, or reverses, Thus, the power supply to the motor M is controlled. In this way, there is no power supply control to motor M. As a result, the output shaft 12 rotates by a predetermined angle.

[0005] By the way, when it comes to electric actuators installed in vehicles, the ignition When the key is turned off or in the event of a malfunction, move the operated parts such as doors to the initial setting position or the safe side. Some have a fail-safe mechanism that allows them to move to the desired position.

[0006] Conventional fail-safe mechanisms can move toward and away from each other along the radial direction. The speed reduction mechanism 11 is equipped with two spur gears that can be used to reduce the speed, and the electromagnetic force of the solenoid is used to It is designed to move the spur gear closer together. The rotary lever 14 also has a A spring is attached that rotates the bar 14 in the direction in which the actuated member moves to the initial setting position, etc. It is attached. When the ignition key is turned off or in the event of a malfunction, the The power to the lenoid has stopped, and the two spur gears that were meshing are now relatively radial. The output shaft becomes free. Then, the rotation lever is moved by the spring force. The actuated member moves to the initial setting position or the like.

[0007]

[Problem that the idea aims to solve]

When the ignition key is turned on again using the above-mentioned failsafe mechanism, When the solenoid is energized, the spur gear connected to the motor M rotates. Moves relatively close to the other spur gear from the radial direction. However, when a rotating spur gear meshes with another spur gear, the teeth may be damaged. There was a risk of injury.

[0008] The present invention was made to solve the problems associated with the above-mentioned conventional technology, and To provide an electric actuator with a fail-safe mechanism that does not cause damage to the The purpose is to

[0009]

[Means to solve the problem]

The present invention, which achieves the above objectives, uses a motor that rotates when energized and a workpiece such as a valve. an output shaft connected to a moving member; and a gear train that transmits rotation of the motor to the output shaft. When the power supply is stopped or a failure occurs, the actuated member is returned to the initial setting position or safe position. and a fail-safe mechanism for shifting the fail-safe mechanism to the a first drive means for connecting and disconnecting the output shaft and the motor; a second driving means for rotating the actuated member in a direction in which it moves to the initial setting position or the like; In the electric actuator, the first drive means is connected to the gear. The worm wheel is rotatably provided in the array and meshes with this worm foil. A worm is attached and is movable along the thrust direction of the worm. a thrust shaft which is attached to the worm wheel and the worm wheel; The solenoid is generated by energizing the electromagnetic force that moves the arm in the direction of engagement. This is an electric actuator constructed by the following.

0010

[Effect]

During normal operation, the thrust shaft is generated by the electromagnetic force generated by the solenoid when energized. The shaft moves in the direction where the worm wheel and worm engage, ensuring a fail-safe The first drive means of the mechanism connects the output shaft and the motor. Then, the rotation of the motor is transmitted to the output shaft via the gear train, and the actuated member connected to this output shaft outputs the It is driven according to the rotation angle of the shaft.

[0011] On the other hand, when the power is stopped or there is a malfunction, the power to the solenoid is stopped and the electromagnetic The force is removed and the thrust shaft is free to move along the thrust direction of the worm. state, the first drive means of the fail-safe mechanism disconnects the output shaft and motor. I do. Then, the output shaft is rotated by the second drive means, and the actuated member returns to the initial setting. position or move to a safer position. The rotation of the output shaft is also transmitted to the worm wheel. and a thrust shaft with a worm attached that meshes with this worm wheel. The worm moves along the thrust direction in which the worm leaves the worm foil.

0012 When the electric actuator is activated again, the solenoid is energized and The generated electromagnetic force causes the thrust shaft to move in the thrust direction, causing the worm and worm to move. form foil and mesh together. At this time, the rotation of the motor is transmitted to the worm and Even if the worm is rotating, the teeth will not be damaged due to the structure of the worm and worm wheel. It won't hurt.

[0013]

【Example】

Hereinafter, one embodiment of the present invention will be described in detail based on the drawings.

[0014] 1 and 2 are sectional views and diagrams showing an electric actuator according to an embodiment of the present invention. 3 is a schematic circuit diagram of the same embodiment, and parts common to those shown in FIG. 4 are the same. , and some explanations thereof will be omitted.

[0015] As shown in FIG. 1, the electric actuator of this embodiment has a lower case 25a and an upper case. A motor M and a motor M are housed in a casing 25 consisting of a a deceleration mechanism 11 that decelerates the rotation of the motor M; and an output shaft 1 rotated by the deceleration mechanism 11. 2 and a rotation control section 13 (see FIG. 4) that controls the rotation of the motor M. Ru. Then, the rotation of the output shaft 12 is controlled by a rotating lever 14 attached to the output shaft 12. The control cable 15 is connected to the rotating lever 14 to control the workpiece. The movable member 26 is driven. Furthermore, this electric actuator has When the ignition key is turned off or in the event of a failure, the connection between the output shaft 12 and motor M is A fail safety switch that disconnects the actuated member 26 and moves the actuated member 26 to an initial setting position or a safe position. A roof mechanism 27 is provided. The actuated member 26 is, for example, an air compressor for an automobile. Adjusts the amount of engine cooling water to the heater core (not shown) provided in the conditioner. This is a water valve.

[0016] The speed reduction mechanism 11 includes a first spur gear 29 connected to a rotating shaft 28 of a motor M; A second spur gear 30 that meshes with the first spur gear 29 and a second spur gear 30 that is coaxial with the second spur gear 30. It has a rotating third spur gear 31.

[0017] The failsafe mechanism 27 connects and disconnects the output shaft 12 and the motor M. The connection between the first drive means 27a, the output shaft 12, and the motor M, which performs the The water valve 26 rotates the rotary lever 14, which is in a state of - in the direction that opens the water channel. It has a second driving means 27b for driving.

[0018] The first driving means 27a is a slurry movable along the axial direction of the third spur gear 31. The thrust shaft 33 has a third spur gear 31 which is always connected to the thrust shaft 33. A fourth spur gear 32 that is in mesh is attached. One end of the thrust shaft 33 A solenoid 34 is provided in the section, and the solenoid 34 is energized. Due to the electromagnetic force generated by the Move in the direction. Further, approximately in the center of the thrust shaft 33 in the axial direction, there is a wall. 35 is attached. Therefore, the worm 35 moves along its thrust direction. It can be moved freely. The worm foil 36 that engages with the worm 35 is attached to the cage. It is rotatably provided in the worm wheel 36 and is located in front of the center of rotation of the worm wheel 36. A recording output shaft 12 is attached. Then, the worm wheel 36 is connected to the arrow C in the figure. When the rotation lever 14 rotates in the same direction C, the rotation lever 14 also rotates in the same direction C around the output shaft 12. , this rotational motion is transmitted to the water valve 26 via the control cable 15. The water valve 26 is configured to rotate in the O direction to open the water channel. Ru.

[0019] Also, the length L where the worm 35 and the worm wheel 36 engage is the thrust. In order to allow the shaft 33 to move in the thrust direction indicated by arrow A in the figure, A shaft housing portion 39 is formed in the casing 25 .

[0020] In the illustrated embodiment, the output shaft 12 is attached to the rotation center of the worm wheel 36. However, the first driving means 27a is not limited to this case. , a worm wheel at any position of the gear train that transmits the rotation of the motor M to the output shaft 12. A worm wheel 36 and a worm 35 that meshes with this worm wheel 36 are attached. It has a last shaft 33, and this thrust shaft 33 is connected to the thrust of the worm 35. Any structure may be used as long as it can be moved along the direction.

[0021] In the illustrated example, the second driving means 27b connects the tip of the rotary lever 14 and the vehicle body. 38 and a tension coil spring 37 attached between the water valve 26 and the water valve 26. An elastic force is acting on the rotation lever 14 to rotate it in the O direction. water valve When the water valve 26 is rotated in the O direction and the waterway is opened, the water valve 26 is at its initial state. This is the default setting position or the safe position. In addition, the elastic force of the tension coil spring 37 is Of course, the force is set to be smaller than the operating torque of the rotating lever 14. It is about.

[0022] Note that the second driving means 27b is not limited to the tension coil spring 37, A direction in which the output shaft 12 moves the actuated member 26 to the initial setting position or a safe position. It is fine as long as it rotates. For example, attach a spiral spring to the output shaft 12. Alternatively, a hydraulic cylinder may be attached to the rotating lever 14.

[0023] The electric actuator configured in this way is used in automobile air space, as shown in Figure 3. Connected to the control unit 40 of the air conditioner, this control unit Based on the signal from 40, power supply to the motor M is controlled. Also, the solenoid 34 is also connected to the control unit 40, and this control unit 40 Power supply to the solenoid 34 is controlled based on these signals.

[0024] Next, the operation of this embodiment will be explained.

[0025] As shown in Figure 1, when the automobile air conditioner is operating, the control The solenoid 34 continues to be energized based on the signal from the control unit 40, and the solenoid 34 continues to be energized. Electromagnetic force is generated in the lenoid 34. This electromagnetic force causes the thrust shaft 33 is maintained in the thrust direction shown by arrow B in the figure, and the thrust shaft The worm 35 of 33 and the worm foil 36 are engaged with each other.

[0026] Also, based on the signal from the control unit 40, the motor M is energized. by stopping, continuing, or reversing the motor M. Electricity is also controlled. The rotation of the motor M due to this energization control is caused by the reduction mechanism 11→ Fourth spur gear 32 of thrust shaft 33 → Worm 35 of thrust shaft 33 →It is transmitted to the worm wheel 36, and the output shaft 12 is in the rotation direction of the worm wheel 36. It will rotate by a predetermined angle in the same direction.

[0027] For example, when the worm wheel 36 and the output shaft 12 rotate in the direction of arrow C in the figure, The rotating lever 14 fixed to the output shaft 12 also rotates in the same direction C around the output shaft 12. do. This rotational movement of the rotary lever 14 is controlled by a control cable 15. The water valve 26 rotates in the O direction to open the water channel. Ru. Conversely, when the worm wheel 36 and the output shaft 12 rotate in the direction of arrow D in the figure, The rotating lever 14 rotates in the same direction D against the elastic force of the tension coil spring 37, and The water valve 26 will rotate in the S direction to close the water channel.

[0028] When the output shaft 12 is rotated by a predetermined angle in this way, the output shaft 12 is rotated by a corresponding angle. Since the water valve 26 opens and closes, the opening and closing of the water valve 26 is linear. It is possible to linearly control engine cooling water to the heater core, and automatic It becomes possible to improve the temperature control of the vehicle air conditioner.

[0029] On the other hand, when the ignition key is turned off or there is a malfunction, as shown in Figure 2, The failsafe mechanism 27 is activated, and the output shaft is 12 and the motor M are disconnected, and the water is removed by the action of the second driving means 27b. Valve 26 rotates in the O direction to open the water channel.

[0030] In detail, when the ignition key is turned off, the solenoid 34 is The energization is stopped, and no electromagnetic force is generated in the solenoid 34. For this reason, the slus The shaft 33 is now movable in the thrust direction, and the worm 35 is also in the thrust direction. The worm wheel 36 is engaged with the worm wheel 36 while being freely movable in the opposite direction. Also, the pull Due to the elastic force of the tension coil spring 37, the rotating lever 14 is rotated around the output shaft 12. Since the water valve 26 rotates in the direction of arrow C in the figure, the water valve 26 rotates in the O direction and to the default open position or the safe position.

[0031] When the rotary lever 14 rotates in this way, this rotational movement is transmitted via the output shaft 12. is transmitted to the worm wheel 36, and the worm wheel 36 also rotates in the same direction C. I will do it. As mentioned above, the worm 35 is movable in its thrust direction. Since the worm 35 is engaged with the worm wheel 36 in this state, the worm 35 is engaged with the worm wheel 36. As the beam wheel 36 rotates, a distance L (see FIG. 1) moves in the thrust direction indicated by arrow A in the figure. ) and the engagement with the worm wheel 36 is released. Also, thrust One end of the shaft 33 is also moved by a distance L and stored in the shaft storage section 39. become. This state where the worm 35 and the worm wheel 36 are disengaged However, the fourth spur gear 32 of the thrust shaft 33 is the third spur gear 3 of the reduction mechanism 11. It meshes with 1.

[0032] When the electric actuator operates again, the solenoid 34 starts to be energized. The generated electromagnetic force causes the thrust shaft 33 to move in the thrust direction indicated by arrow B in the figure. The worm 35 and the worm foil 36 are brought into engagement with each other. this When the rotation of the motor M is transmitted to the worm 35, the worm 35 rotates. However, the structure of the worm 35 and worm wheel 36 prevents damage to the teeth. do not have.

[0033]

[Effect of the idea]

As explained above, according to the present invention, a fail-safe method that does not cause damage to the teeth can be achieved. We were able to provide an electric actuator with a mechanism.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing a normal state of an electric actuator according to an embodiment of the present invention.

FIG. 2 is a sectional view showing a state when the failsafe mechanism of the same embodiment is activated.

FIG. 3 is a schematic circuit diagram of the same embodiment.

FIG. 4 is an exploded perspective view showing a general electric actuator.

[Explanation of symbols]

27... Fail safe mechanism 27a... First drive means 27b... Second drive means 33... Thrust shaft 34... Solenoid 35... Worm 36... Worm foil 37... Tension coil spring M... Motor

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[Procedural amendment]

[Submission date] June 5, 1991

[Procedural amendment 1]

[Name of document to be corrected] Drawing

[Correction target item name] Full map

[Correction method] Change

[Correction details]

[Figure 1]

[Figure 2]

[Figure 3]

[Figure 4]

Claims (1)

[Scope of utility model registration request] Claim 1: A motor (M) that rotates when energized, an output shaft (12) connected to an actuated member (26) such as a valve, and a motor that rotates the motor (M) to the output shaft (12). A transmission gear train,
It has a fail-safe mechanism (27) that moves the actuated member (26) to an initial setting position or a safe position when electricity is stopped or a failure occurs, and the fail-safe mechanism (27) is connected to the output shaft. (12) and a first driving means (27a) for connecting and disconnecting the motor (M), and a direction in which the actuated member (26) moves the output shaft (12) to the initial setting position, etc. and a second drive means (27b) for rotating the first drive means (27a), a worm wheel (36) rotatably provided on the gear train;
A thrust shaft (33) is provided with a worm (35) that meshes with this worm wheel (36) and is movable along the thrust direction (A, B) of the worm (35), and this thrust shaft (33). and a solenoid (34) that generates an electromagnetic force when energized to move the worm wheel (36) and the worm (35) in a direction (B) in which they engage.