JPH04128306U - Operating axis return-to-origin structure of electric linear actuator - Google Patents

Abstract

(57) [Summary] [Purpose] To develop a structure for returning the operating shaft of an electric linear actuator to its original position, in which the operating shaft provided on a nut that moves on a screw shaft rotated by a motor retracts from the frame. to provide. [Structure] The operating axis return-to-origin structure includes a movable member that can move along the screw shaft and come into contact with the nut, an elastic body that presses the movable member against the nut, and a movable member that is provided on the frame and is biased by the elastic body. It has an origin setting stopper that receives the member. As the screw shaft rotates, the nut and the moving member move against the elastic body, and the operating shaft moves in and out of the frame. When the motor is stopped after the operation of the operating axis is completed,
The nut moves back on the screw shaft while causing the rotatable screw shaft to reversely rotate due to the biasing force of the elastic body. During this return movement, the moving member comes into contact with the origin setting stopper and stops. This means that the operating axis has returned to its original position.

Description

[Detailed explanation of the idea]

0001

[Industrial application field]

This invention is a structure for returning the operating axis of an electric linear actuator to its home position after operation. Regarding construction.

0002

[Conventional technology]

Conventionally, electric linear actuators (not shown) move on a screw shaft rotated by a motor. The actuating shaft installed on the moving nut moves in and out of the frame, moving the actuated object in a straight line. It is designed to move. After an electric linear actuator has been used once, when it is used again, the actuating shaft must be moved to the correct position. Sometimes it is necessary to start the movement from a fixed origin position. However, electric linear actuators are equipped with a home return mechanism that returns the operating axis to the home position. Since it is not grounded, it is not possible to apply external force using ancillary equipment such as weights or air cylinders. In addition, the operating axis is moved to either end of the movement range.

0003

[Problem that the idea aims to solve]

However, such electric linear actuators do not have a return-to-origin mechanism, so they are difficult to operate. Ancillary equipment such as a weight or air cylinder that applies an external force to the moving shaft is required; Problems such as difficulty in setting the origin position in the middle of the movement stroke of have.

0004

[Means to solve the problem]

This invention is based on a mechanism installed on a nut that moves on a screw shaft rotated by a motor. In an electric linear actuator where the moving shaft protrudes and retracts from the frame, along the screw shaft a movable member that is movable and capable of abutting the nut; and a movable member that presses the movable member against the nut. an elastic body brought into contact with the moving part provided on the frame and biased by the elastic body; The operating axis return-to-origin structure, which has an origin setting stopper that receives the material, enables the above-mentioned This is a solution to a problem.

[0005]

[Effect]

As the screw shaft rotates, the nut moves on the screw shaft, and the operating shaft is aligned with the frame. They appear and move around. At this time, the elastic body is compressed as the nut moves. When the motor is stopped after the actuating shaft protrudes or retracts by a predetermined amount, the screw shaft is driven to rotate. No force is applied, and the screw shaft becomes freely rotatable. Since the nut is biased by an elastic body through a moving member, this biasing force The nut is moved back on the screw shaft while rotating the screw shaft in the opposite direction. child By the return movement of the nut, the actuating shaft retracts or protrudes from the frame. At this time, the moving member is also moved back together with the nut. During this return movement, the moving member is pressed against the origin setting stopper and moves back. stop. Therefore, the biasing force of the elastic body is no longer applied to the nut, and the nut is moved. Return movement is stopped together with the moving member. This causes the operating axis to return to its home position. I was forced to do so.

[0006]

【Example】

Hereinafter, embodiments of the present invention will be described based on the drawings. The electric linear actuator 10 includes a screw shaft 12 rotated by a motor 11; A nut 14 screwed into the frame 13 and prevented from rotating; It includes a cylindrical operating shaft 15 and an origin return structure 30. The rotational force of the motor 11 is transmitted through a speed reduction mechanism consisting of a plurality of gears 16, 17, 18, and 19. 20 to be transmitted to the screw shaft 12. The rotation of the nut 14 with respect to the frame 13 is prevented by a combination provided on the frame 13. Several rotation regulating shafts 31, 31 pass through two flanges 32, 33 that are integral with the nut 14. It is done by doing.

[0007] The origin return structure 30 includes moving members 34, 34, 35, 35 and a coil spring. (Elastic bodies) 36, 36, 37, 37 and origin setting stoppers 38, 38, 39, 3 It consists of 9. The moving members 34 and 35 move onto the rotation regulating shaft 31 on both sides of the two collars 32 and 33. possible. The coil springs 36, 36, 37, 37 are attached to the head side plate 131 of the frame 13. and the movable members 34, 34, and between the bottom side plate 132 of the frame 13 and the movable member 35. , 35 on the rotation regulating shafts 31, 31. The origin setting stoppers 38, 38, 39, and 39 are provided on the frame 13. , the moving members 34 and 35 are brought into contact with the tips thereof. In addition, in FIG. 1, the heads of the origin setting stoppers 38 and 39 near the motor 11 are , the motor 11 and the frame 13 are in a state of being sandwiched, but this is not explained. For the sake of clarity, origin setting stoppers 38, 39 and rotation regulating shaft 31 are placed directly below the motor 11. etc., and actually the origin setting stoppers 38, 39, rotation regulating shaft 3 The first type is provided at a position away from the motor 11.

[0008] Next, the operation will be explained. When the motor 11 is started, the screw shaft 12 is rotated at a reduced speed by the speed reduction mechanism 20, and the nut is rotated at a reduced speed. The shaft 14 moves on the screw shaft 12 in the direction of arrow A in FIG. As the nut 14 moves, The actuating shaft 15 protrudes from the frame 13 and actuates an actuated body (not shown). . During this time, the coil springs 36, 36 are connected to the nut 1 via the moving members 34, 34. Compressed by 4. Of course, the driving force of the motor 11 is derived from the coil spring 3. It must exceed the elastic repulsive force of 6.37.

[0009] After the operating shaft 15 has protruded a predetermined amount, when the motor 11 is stopped, the screw shaft 12 is driven. No rotational force is applied, and the screw shaft 12 becomes rotatable. Coil springs 36, 36 are connected to the nut 14 via moving members 34, 34. Due to the applied force, this elasticity causes the nut 14 to rotate the screw shaft 12 in the opposite direction. while moving back on the screw shaft 12. This causes the actuating shaft 15 to become free. Immerse yourself in the game 13. At this time, the moving members 34, 34 are also returned together with the nut 14. be moved. During this return movement, the moving members 34, 34 touch the origin setting stoppers 36, 36. It is brought into pressure contact and stops returning. For this reason, the coil spring 3 is attached to the nut 14. 6 and 36 are no longer applied, and the nut 14 returns together with the moving members 34 and 34. and stop moving. As a result, the operating shaft 15 has been returned to its original position. become.

0010 The above operation describes the operation when the actuating shaft 15 is protruded, but conversely, when the actuating shaft 15 is immersed In this case, the left moving members 35, 35, coil springs 37, 37, Origin setting stops 39, 39 similarly return operating shaft 15 to the origin position. Therefore, the origin return structure 30 allows the operating shaft 15 to move in and out of the frame 13. Even if the operation is performed, the operating axis 15 remains at the origin position set at the intermediate position of the frame 13. can be restored to.

[0011] Note that the above home return structure 30 has moving members and coil springs on both sides of the nut 14. It is equipped with an origin setting stopper, but it may be provided on only one side. . In this case, the right moving member 34, the coil spring 36, the origin setting stopper If only 38 is provided, the operating shaft 15 that has stopped protruding will be moved to the middle position of the frame 13. It can be pushed back into place. Left side moving member 35, coil spring 37, origin If only the setting stopper 39 is provided, the operating shaft 15 that has stopped while being recessed will be removed from the frame. It can be pushed back to the intermediate position of 13. Also, by changing the position of the origin setting stoppers 38 and 39, the origin return position can be adjusted. Of course, it is possible to change.

0012

[Effect of the idea]

The operating axis return-to-origin structure of the present invention has the following effects. Since it is installed inside the electric linear actuator, it eliminates the need for weights and air, which were previously required. Ancillary equipment such as cylinders becomes unnecessary. By changing the position of the origin setting stopper, the origin position can be changed to the movement stroke of the operating axis. You can freely set it in the middle of the arc.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view along the operating axis of an electric linear actuator equipped with an operating axis return-to-origin structure according to the present invention.

[Explanation of symbols]

10 Electric linear actuator 11 Motor 12 Screw shaft 13 frames 14 Nut 15 Operating axis 30 Origin return structure 34, 35 Moving member 36, 37 Coil spring (elastic body) 38, 39 Origin setting stopper

Claims (1)

[Scope of utility model registration request] Claim 1: In an electric linear actuator in which an actuating shaft provided on a nut that moves on a screw shaft rotated by a motor protrudes and retracts from a frame, the actuator is movable along the screw shaft and can come into contact with the nut. An electric linear operation characterized by having a moving member, an elastic body that presses the moving member against the nut, and an origin setting stopper that is provided on the frame and receives the moving member biased by the elastic body. Motivation axis return-to-origin structure.