JP2000234652A - Actuator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To stop a turn shaft by making it holdable by fixed force, scarcely generate an impact noise and a defect in a structural part of worm wheel or the like. SOLUTION: This actuator, comprising a normal/reverse rotatable motor 2, worm 5 formed in an output shaft 4 of the motor 2, worm wheel 6 meshed with the worm 5, and a turn shaft 8 positioned on the shaft center of the worm wheel 6 to output turning force of the motor 2 transmitted through the worm wheel 6 to the outside, is provided with a clutch mechanism 20 regulating a turning range of the turn shaft 8 and restricting only the turn shaft 8 in its turn end to permit turning of the worm wheel 6, also provided with a control switch 9 abutting to the worm wheel 6 continuing turning in a stage restricting the turn shaft 8 by the clutch mechanism 20 to interrupt supply of power to the motor 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an actuator used for a high-speed / low-speed switching mechanism and a 2WD / 4WD switching mechanism of a four-wheel drive vehicle.

[0002]

2. Description of the Related Art Conventionally, as an actuator employed in a high-speed / low-speed step switching mechanism of a four-wheel drive vehicle as described above, for example, a motor capable of rotating forward and reverse and a worm formed on an output shaft of the motor are used. There is a worm wheel that meshes with the worm, and a worm wheel that is located on the axis of the worm wheel and has a rotating shaft that rotates in a predetermined range by the rotating force of the motor transmitted through the worm wheel,
At the rotating end of the rotating shaft, reverse rotation is prevented by engagement of the worm and the worm wheel, and the rotating shaft is held with a constant force.

[0003]

However, in the above-described conventional actuator, when the rotation shaft is stopped, the output shaft of the motor is locked, so that a large portion is formed at the meshing portion between the worm and the worm wheel. There is a problem that an impulsive sound is generated and there is a possibility that the worm or the worm wheel teeth may be damaged by the impact load at this time, and it is a conventional problem to solve this problem. Was.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems, and it is possible to hold the rotating shaft with a constant force and to generate almost no impact noise. Further, it is an object of the present invention to provide an actuator capable of stopping a rotating shaft without causing a trouble in a structural component such as a worm and a worm wheel.

[0005]

According to the first aspect of the present invention, there is provided a motor capable of rotating forward and reverse, a worm formed on an output shaft of the motor, a worm wheel meshing with the worm, and an axial center of the worm wheel. An actuator having a rotating shaft for outputting a rotating force of a motor transmitted through a worm wheel to an external device, wherein the rotating range of the rotating shaft is regulated, and the rotating shaft is rotated at its rotating end. A clutch mechanism is provided to restrict the rotation of the worm wheel by restricting only the worm wheel, and the power supply to the motor is cut off by contacting the worm wheel that continues to rotate when the rotation shaft is restricted by the clutch mechanism. The actuator is characterized in that it has a configuration in which a control switch is provided.

[0006] In the actuator according to the second aspect of the present invention, the clutch mechanism includes a transmitting body that rotates with the worm wheel, a rotating body that has an annular wall surrounding the transmitting body and rotates with the rotating shaft, The two moving bodies respectively held movably in the radial direction at intervals corresponding to the rotation range of the rotating shaft on the annular wall of the moving body, and the moving body positioned around the annular wall of the rotating body. A guide body that is pressed toward the center and protrudes from the annular wall, and the transmission body is located on the delay side in the rotation direction of the transmission body among the moving bodies that are pressed by the guide body and project toward the center. Notch for transmitting the rotational force of the motor to the rotating body by engaging with the moving body,
The guide body allows the moving body located on the delay side in the rotation direction of the transmission body at the rotating end of the rotating body to move in the centrifugal direction and engages with the moving body detached from the notch to form the rotating body. Provide a concave portion to stop, at the stage when the rotating body has stopped,
The transmission body restricts the movement of the moving body engaged with the concave portion of the guide body in the radial direction.

In the actuator according to a third aspect of the present invention, two sets of two moving bodies are provided on the annular wall of the rotating body at an interval of 180 °, and the notch of the transmission body and the recess of the guide body are respectively provided. It is configured to be provided at two places at an interval of 180 °.

[0008] In the actuator according to claim 4 of the present invention, the moving body has a roller shape. In the actuator according to claim 5 of the present invention, the moving body includes a pin and a roller member fitted to the pin. It is provided with a configuration.

In the actuator according to the sixth aspect of the present invention, a locking portion is provided on the annular wall of the rotating body, and the guide body is locked with the locking portion of the rotating body to regulate the rotation range of the rotating body. The structure is provided with a stopper.

[0010]

In the actuator according to the first aspect of the present invention, even if the rotation shaft reaches the rotation end and its operation is stopped by the clutch mechanism, the worm wheel itself comes into contact with the control switch and the motor is driven. The rotation continues until the power supply to the motor is cut off, preventing the output shaft of the motor from being locked.As a result, a loud impact sound is generated at the meshing portion between the worm and the worm wheel. Also, damage to the worm or the tooth portion of the worm wheel due to an impact load can be avoided.

At the rotation end of the rotation shaft, the rotation shaft is continuously restrained by the clutch mechanism, so that the rotation shaft is held with a constant force.

In the actuator according to the second aspect of the present invention, when the rotating body reaches the rotating end, the rotating body is engaged with the notch of the transmitting body to transmit the torque of the motor to the rotating body. Of the moving bodies, the moving body located on the delay side in the rotation direction of the transmission body is separated from the notch, moves in the centrifugal direction and engages with the recess of the guide body, so that only the rotating body stops and the moving body Is disengaged, the transmission body continues to rotate.

When the rotating body is stopped, the transmitting body regulates the radial movement of the moving body engaged with the concave portion of the guide body. The moving shaft is held with a constant force.

In the actuator according to the third aspect of the present invention, since the actuator has the above-described structure, the transmission of the rotational force of the motor to the rotating body can be reliably shut off. Since the actuator has the above-described configuration, transmission of the rotational force of the motor to the rotating body is smoothly interrupted.

In the actuator according to the sixth aspect of the present invention, since the above-described configuration is employed, the rotation range of the rotary body is reliably restricted.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings.

FIGS. 1 to 5 show an embodiment of an actuator according to the present invention. In this embodiment, the actuator according to the present invention is employed in a high-speed / low-speed switching mechanism of a four-wheel drive vehicle. This is a case where the actuator is a suitable actuator.

As shown in FIGS. 1 and 2, the actuator 1 comprises a motor 2, a worm 5 formed on the distal end of an output shaft 4 protruding into a gear case 3 connected to the motor 2, and a gear case. A worm wheel 6 housed in the worm wheel 3 and meshing with the worm 5, and an end (right end in FIG. 1A) located on the axis of the worm wheel 6 and protruding from the gear case 3 to the outside. A rotating shaft 8 to which an arm 7 for driving a low-speed gear change clutch is fixed is provided.

In this case, the gear case 3 is provided with a clutch mechanism 20 which regulates the rotation range of the arm 7 and restricts only the arm 7 at the rotation end thereof to allow the rotation of the worm wheel 6. A control switch 9 is provided for contacting with the worm wheel 6 which continues to rotate when the arm 7 is restrained by the clutch mechanism 20 to cut off the supply of power to the motor 2.

The clutch mechanism 20 includes a drive lever (transmitter) 21 fitted on the rotation shaft 8 and rotated together with the worm wheel 6, an annular wall 22 c surrounding the drive lever 21, and a square hole located on the axis. 22d and this square hole 22d
A rotor (rotating body) 22 that is fitted to the square shaft portion 8 a of the rotating shaft 8 and rotates together with the rotating shaft 8, and an interval corresponding to the rotating range of the arm 7 on the annular wall 22 c of the rotor 22. And two moving bodies 23, 23 movably held in radial sliding grooves 22 a, 22 a provided at a distance from each other, and the moving body 23 being positioned around the annular wall 22 c of the rotor 22 and centered on the moving body 23. The moving body 23 is provided with a pin 23a and ball bearings (roller members) 23b, 23b fitted on both ends of the pin 23a, respectively. Has become.

The drive lever 21 has a protrusion 21 a provided on the surface facing the worm wheel 6.
3 is rotated integrally with the worm wheel 6 by fitting into the recess 6a provided on the guide body 24, as shown in FIG. The moving body 23 (the moving body 2 on the left side in FIG. 3A) which is located on the delayed side in the rotation direction of the drive lever 21 among the moving bodies 23 that are pressed and protruded toward the center.
At 3 and 23, the drive lever 21 rotates counterclockwise, so that it engages with the moving body 23) located on the upper side and
A notch 21b for transmitting the rotational force to the rotor 22 is provided.

The guide body 24 includes a screw 2 in the gear case 3.
5 and the annular wall 22c of the rotor 22
3D, a rotor 22 is provided as shown in FIG.
At the rotation end thereof, the moving body 23 located on the delay side in the rotation direction of the driving lever 21 is allowed to move in the centrifugal direction, and engages with the moving body 23 detached from the notch 21b of the driving lever 21 to engage with the rotor 22. When the rotor 22 stops, a concave portion 24a for stopping the rotation is provided.
As shown in (e) and (f), the outer peripheral surface 21c of the drive lever 21 regulates the radial movement of the moving body 23 engaged with the concave portion 24a of the guide body 24 to apply a constant force to the arm 7. To keep it.

In this embodiment, two moving bodies 23,
Two sets 23 are provided on the annular wall 22c of the rotor 22 at an interval of 180 °, and correspondingly, the notch 21b of the drive lever 21 and the recess 24a of the guide body 24 are also provided at an interval of 180 °. It is provided in two places.

In the portion of the guide body 24 surrounding the annular wall 22c of the rotor 22, stoppers 24b are provided at two places at an interval of 180 °.
b and 24b are recesses (locking portions) 22 provided along the circumferential direction provided at 180 ° intervals on the annular wall 22c of the rotor 22.
b, 22b.

That is, at the rotating end of the rotor 22, the moving body 23 is engaged with the concave portion 24a of the guide
In addition to restricting the rotation of the rotor 22, the rotation of the rotor 22 is restricted by locking the respective ends of the recesses 22b, 22b of the rotor 22 to the stoppers 24b, 24b of the guide body 24, respectively. Has become.

On the other hand, two control switches 9 are provided at 90 ° intervals on a holder 12 provided between the cover 11 for closing the gear case 3 via the packing 10 and the worm wheel 6. As shown in FIG. 4, when the arm 7 is restrained, the arm 7 comes into contact with both ends of a rotation restricting portion 6b provided on the worm wheel 6 which continues to rotate together with the drive lever 21. The switches 9 and 9 are connected to a switching controller 13 as shown in FIG.

The switching controller 13 has two transistors 14 and 15. When the ignition switch 16 is turned on, the first relay switch 17 is turned on through the first transistor 14 to turn on the motor. 2 forward, while the second
By turning on the second relay switch 18 through the transistor 15, the motor 2 is rotated in the reverse direction. In any case, the end of the rotation restricting portion 6 b of the worm wheel 6 contacts the control switch 9. The power supply to the motor 2 is stopped when the control switch 9 is turned on.

1 and 2, reference numeral 31 denotes a connecting pin, reference numeral 32 denotes a nut, reference numeral 33 denotes a spring washer, reference numeral 34 denotes an oil seal, reference numerals 35 and 36 denote ball bearings, and reference numeral 37 denotes a breather. Numerals 38 and 39 are a lead wire and a grommet.

When the actuator 1 is switched from the high speed stage to the low speed stage, first, with the ignition switch 16 turned on, the first relay switch 17 is turned on through the first transistor 14 of the switching controller 13 to turn on the motor 2. When power is supplied to the motor 2, the motor 2 starts rotating in the forward direction, and the driving lever 21 of the clutch mechanism 20 changes from the state shown in FIG. 3A by the rotational force of the motor 2 transmitted through the worm wheel 6. Rotation starts counterclockwise.

Next, as shown in FIG. 3 (b), the notches 21b, 21b of the drive lever 21 are pushed by the guide body 24 and protrude toward the center. 3B, the rotating force of the motor 2 is transmitted to the rotor 22 when the moving body 23 is engaged with the moving body 23 (the moving body 23 positioned on the upper left and lower right sides in FIG. 3B). As shown in FIG.
2 rotates together with the drive lever 21, that is, the arm 7 rotates to drive the clutch to the lower speed side.

Subsequently, when the rotor 22 (arm 7) reaches the rotation end and is switched to the low speed stage, as shown in FIG. 3 (d), the rotor 22 (arm 7) engages with the notch 21b of the drive lever 21. Moving bodies 23, 23 located on the delay side in the rotation direction of the drive lever 21 that has transmitted the rotational force of the motor 2 to the rotor 22.
Are disengaged from the notches 21b, 21b, move in the centrifugal direction and engage with the recesses 24a of the guide body 24, respectively.
The rotor 22 stops together with the arm 7, while the moving body 2
The drive lever 21 that has been disengaged from the drive levers 3 and 23 is shown in FIG.
As shown in (e), rotation continues with the worm wheel 6.

Then, as shown in FIG. 4, when the end of the rotation restricting portion 6b of the worm wheel 6 which continues to rotate contacts the control switch 9, the control switch 9 is turned on. When the first relay switch 17 is turned off by the command from the controller 2, the power supply to the motor 2 is stopped at this time, and until the motor 2 stops, as shown in FIG. It rotates together with the wheel 6 by inertia and stops.

When switching from the low-speed stage to the high-speed stage, when the second relay switch 18 is turned on through the second transistor 15 of the switching controller 13 to supply power to the motor 2, the motor 2 rotates in the reverse direction. And the driving lever 21 of the clutch mechanism 20 starts rotating clockwise from the state shown in FIG. 3F by the torque of the motor 2 transmitted via the worm wheel 6. Conversely, switching to the high-speed stage is performed through the steps of FIGS. 3 (e) to 3 (a).

Therefore, in the state shifted to the high speed stage or the low speed stage, FIG. 3 (f) or FIG.
As shown in FIG. 7, the outer peripheral surface 21c of the drive lever 21 restricts the radial movement of the moving body 23 engaged with the concave portion 24a of the guide body 24, so that the constraint of the rotor 22 is held, that is, the arm 7 is held with a constant force.

When the rotor 22 reaches the rotation end, only the rotor 22 stops and the worm wheel 6
The rotation of the output shaft 4 of the motor 2 is prevented since the end of the rotation restricting portion 6b contacts the control switch 9 and the rotation is continued until the power supply to the motor 2 is cut off. As a result, a loud impact sound is generated at the meshing portion between the worm 5 and the worm wheel 6, and the tooth portion of the worm 5 or the worm wheel 6 is prevented from being damaged by the impact load. It will be.

In the actuator 1 described above, the two moving bodies 23 are attached to the annular wall 22c of the rotor
Two sets are provided at an interval of 0 °, and the notch 21b of the drive lever 21 and the guide body 24 are correspondingly provided.
Are also provided at two places with an interval of 180 °, so that the transmission of the rotational force of the motor 2 to the rotor 22 can be reliably shut off. In this actuator 1, the pins 23a and This pin 23a
Ball bearings 23b fitted at both ends of the
23b, the moving body 23 is constituted by the rotor 2
In addition, in the actuator 1, the stopper 24b is provided at a portion of the guide body 24 surrounding the annular wall 22c of the rotor 22, and the rotation of the rotor 22 is prevented. Recess 22b that can be locked to the stopper 24b on the annular wall 22c
Is provided, the rotation range of the rotor 22 is surely regulated.

In the above-described embodiment, the case where the actuator according to the present invention is an actuator employed in a high-speed / low-speed switching mechanism of a four-wheel drive vehicle has been described. However, the present invention is not limited to this. 2W of four-wheel drive vehicle
Naturally, it can be used as an actuator of a D / 4WD switching mechanism.

Further, in the above-described embodiment, the moving body 23 is composed of the pin 23a and the ball bearings 23b and 23b fitted respectively to both ends of the pin 23a. However, the present invention is not limited to this. As another configuration, for example, the moving body may be formed into a roller shape or a spherical shape.

[0039]

As described above, according to the first aspect of the present invention,
According to the actuators according to the first and second aspects, since the above-described configuration is employed, the rotating shaft can be held with a constant force, and when the rotating shaft is stopped, a large portion is formed at the meshing portion between the worm and the worm wheel. It is possible to obtain an extremely excellent effect that it is possible to prevent the generation of an impact sound and to prevent the worm or the worm wheel from being damaged by the impact load.

According to the actuator of the third aspect of the present invention, since the above-described structure is employed, the rotational force of the motor can be reliably transmitted to the rotating body and cut off.
Since the actuator according to the fourth and fifth aspects of the present invention has the above-described configuration, it is possible to obtain an extremely excellent effect that the transmission of the rotational force of the motor to the rotating body can be smoothly interrupted.

In the actuator according to the sixth aspect of the present invention, since the actuator has the above-described structure, an extremely excellent effect that the rotation range of the rotating body can be more reliably regulated can be obtained.

[0042]

[Brief description of the drawings]

FIGS. 1A and 1B are an explanatory sectional view and an explanatory plan view showing an embodiment of an actuator according to the present invention.

FIG. 2 is an exploded perspective view of a gear case in the actuator shown in FIG.

3 (a) to 3 (f) are explanatory views of the operation of a clutch mechanism in the actuator shown in FIG. 1;

FIG. 4 is an explanatory plan view showing a relationship between a control switch of an actuator and a worm wheel in FIG. 1 in a state where a cover is removed from a gear case.

5 is an explanatory diagram of an electric circuit of the actuator in FIG. 1. FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Actuator 2 Motor 4 Output shaft 5 Worm 6 Worm wheel 8 Rotating shaft 9 Control switch 20 Clutch mechanism 21 Drive lever (Transmission body) 21b Notch 22 Rotor (Rotating body) 22b Depression (Locking part) 22c Annular wall 23 Movement Body 23a Pin 23b Ball bearing (roller member) 24 Guide body 24a Recess 24b Stopper

Claims (6)

[Claims] A worm formed on an output shaft of the motor, a worm wheel meshing with the worm, and a motor transmitted through the worm wheel positioned on the axis of the worm wheel. An actuator having a rotating shaft for outputting a rotating force to an outside, wherein a clutch mechanism for restricting a rotating range of the rotating shaft and restricting only the rotating shaft at a rotating end thereof to allow rotation of the worm wheel. And a control switch for stopping supply of power to the motor by contacting a worm wheel that continues to rotate when the rotation shaft is restrained by the clutch mechanism. The clutch mechanism includes: a transmission body that rotates with the worm wheel; a rotation body that has an annular wall surrounding the transmission body and rotates with the rotation axis; Two moving bodies each held movably in the radial direction at an interval corresponding to the rotation range; and an annular wall positioned around the annular wall of the rotating body and pressed toward the center to move the moving body toward the center. A motor that engages with the moving member that is located on the delay side in the rotation direction of the transmitting member among the moving members that are pressed by the guiding member and project toward the center. The guide body is provided with a notch for transmitting the rotational force of the rotating body to the rotating body, and the guide body allows movement of the moving body, which is located on the delay side in the rotating direction of the rotating body at the rotating end of the rotating body, in the centrifugal direction; A recess that stops the rotating body by engaging with the moving body detached from the notch The actuator according to claim 1, wherein a portion is provided, and when the rotating body stops, the transmitting body regulates a radial movement of the moving body engaged with the recess of the guide body. 3. The two moving bodies are attached to the annular wall of the rotating body by 180.
3. The actuator according to claim 2, wherein two sets are provided at an interval of ゜, and a cutout portion of the transmission body and a concave portion of the guide body are provided at two places at an interval of 180 °. 4. The actuator according to claim 2, wherein the moving body has a roller shape. 5. The actuator according to claim 2, wherein the moving body includes a pin and a roller member fitted on the pin. 6. A guide member provided with a locking portion on the annular wall of the rotating body, and a stopper for locking the locking portion of the rotating body to restrict a rotation range of the rotating body on the guide body. The actuator according to any one of the above.