JP2600566Y2 - Actuator - Google Patents

Description

[Detailed description of the invention]

[0001]

The present invention relates to an actuator,
In particular, the present invention relates to an actuator that linearly moves an output shaft by a screw structure.

[0002]

2. Description of the Related Art In an actuator for performing a reciprocating linear motion, a pinion is fixed to a rotating shaft of a motor, and an outer periphery of the pinion is meshed with a gear, and an inner periphery is meshed with a gear of a gear formed on an internal thread (inner screw). The inner screw is formed by screwing an output shaft having an outer periphery formed on a male screw (outer screw).

[0003] The rotation of the motor rotates the gear via the pinion to rotate the inner screw.

[0004] The output shaft screwed to the inner screw prevents rotation, so that the output shaft moves linearly when the inner screw rotates.

Conventionally, in this type of actuator, since a tightening torque and a loosening torque of the screw mechanism are present, it is usual to not use a forcible stop structure.

For example, the screw mechanism is configured not to be tightened by stopping the motor, or a continuous operation structure is provided without providing a forced stop mechanism.

In the case of a structure in which the screw is forcibly stopped, the friction coefficient of the screw sliding portion is minimized by using a screw mechanism of a ball screw type.

[0008]

However, in this type of conventional actuator, when the output shaft is forcibly stopped via a stopper or the like, the screw mechanism is caused to have a torque greater than the maximum torque of the motor due to the inertia force of the motor. Is applied.

For example, the tightening torque is about 4 to 5 times the maximum torque of the motor. Further, although the loosening torque varies with the friction coefficient depending on the tightening torque, about 80% of the approximate tightening torque is required.

The loosening torque is three to four times the maximum torque of the motor, and in this state (loose torque> starting torque), the motor cannot be started only by the motor starting torque.

Therefore, in the case where the structure is forcibly stopped, it is necessary to minimize the friction coefficient of the screw sliding portion by using a ball screw system or the like to reduce the tightening torque and the loosening torque of the screw. Increases costs.

A structure in which the motor is stopped and a continuous operation structure without forcible stop, and a structure in which a tightening torque and a loosening torque are not generated has a problem that the use conditions are restricted.

The present invention has been made in view of the above points,
It is an object of the present invention to provide an actuator that can be forcibly stopped with a simple structure and can be reliably started.

[0014]

According to the present invention, a thread portion is formed on an outer periphery of an output shaft, and a female thread portion is screwed into a male thread portion.
In an actuator that reciprocates the output shaft by rotating the female thread according to the rotation of the motor,
A female screw portion is formed on the inner peripheral side, a first convex portion is formed on the outer peripheral side, and a female screw member rotating about the output shaft is provided on the same circumference as the first convex portion. Do not touch the convex part of
A second convex portion formed so as to be displaced in the axial direction of the output shaft so as to be rotatable with respect to the female screw member, the outer periphery of which is engaged with the motor, A gear member rotating about an output shaft, a first convex portion, and a second
Can collide with the first and second protrusions on the same circumference as the protrusion
The output shaft is centered with respect to the female screw member and the gear member.
At least a second convex portion is disposed at the center so as to be rotatable by a predetermined angle.
A rotation transmitting member configured to apply an impact force to the second convex portion when colliding with the portion .

[0015]

According to the present invention, the gear member rotates under load until the second convex portion collides with the third convex portion of the rotation transmitting member, and then the third convex portion becomes the first convex portion. And further rotates with no load together with the rotation transmitting member until collision occurs.

Therefore, the gear member can be rotated by a sufficient rotation angle from the rotation of the gear member to the collision with the female screw member, so that the female screw member can be driven while the rotation of the motor is stable, and the gear can be rotated. After the member has sufficient inertia, it collides with the female thread member,
By tightening the female thread member and the male thread member by applying force
Since torque greater than the mounting torque can be obtained,
The screws remain small and the female and male threads are securely tightened.
Can be released. Also, according to the present invention, the first and second
Since the projection and the rotation transmitting member are arranged on the same circumference,
The mechanism can be downsized.

[0017]

FIG. 1 is a sectional view of an embodiment of the present invention. In the figure, reference numeral 1 denotes a motor, for example, a DC motor. The motor 1 is stored in a storage case 2 and is electrically connected to an external circuit via a circuit board 3.

A motor protection circuit for protecting the motor 1 is formed on the circuit board 3, and is housed in the housing 2 in the same manner as the motor 1.

A pinion 4 is press-fitted and fixed to the rotating shaft 1a of the motor 1. The pinion 4 meshes with a tooth portion 5 a formed on the outer periphery of the gear member 5, and transmits the rotation of the motor 1 to the gear member 5.

The gear member 5 is engaged with an inner screw member 6 which is a female screw member via a rotation transmission member 8, and the rotation of the gear member 5 is performed via the rotation transmission member 8 via the rotation transmission member 8 by a structure described later. The power is transmitted to the screw member 6. The inner screw member 6 has a female screw portion 6c formed on the inner periphery, and the female screw portion 6c has a male screw portion 7a formed on the outer periphery of the output shaft 7.
Screw.

The inner screw member 6 is held in the storage case 2 and rotates about the output shaft 7. A guide portion 7b is fixed to the lower end of the output shaft 7. The guide portion 7b engages with a guide groove 2a formed in the storage case 2 in the operation direction (the direction of the arrow A) of the output shaft 7.

The output shaft 7 is configured so that the guide portion 7b is engaged with the guide groove 2a and does not rotate by the rotation of the inner screw member 6.

For this reason, when the inner screw member 6 rotates, the screw portion 6c is formed on the inner screw member 6 so that the screw portion 6c acts on the external thread portion 7a of the output shaft 7, and the output shaft 7 is moved in the axial direction (direction of arrow A). Make a linear motion.

FIG. 2 is a perspective view of a main part of one embodiment of the present invention.
FIG. 3 is an exploded perspective view of a main part of one embodiment of the present invention. The configuration of the main part of the present invention will be described with reference to FIGS.

The gear member 5 has a tooth portion 5a on the outer periphery, and the tooth portion 5a is press-fitted into the output shaft 1a of the motor 1.
Is disposed in the storage case 2 so as to mesh with the first case. The gear member 5 has a convex portion 5b formed on the inner peripheral portion.

The inner screw member 6, which is a female screw member, has a female screw portion 6c formed on the inner periphery thereof, and the output shaft 7 having a male screw portion 7a formed on the outer periphery thereof is screwed into the female screw portion 6c. . Also, the outer periphery 6 of the female screw portion 6c of the inner screw member 6
d is rotatably engaged with the inner periphery 5d of the gear member 5. A disk-shaped surface 6e extending to the outer periphery is formed on the outer peripheral portion of the inner screw member 6, and a convex portion 6b is formed on the outer peripheral portion so as to face and not engage with the convex portion 5b of the gear member 5. ing. A boss portion 5e is formed on the inner peripheral portion of the gear member 5, and an inner peripheral hole 8a of the rotation transmitting member 8 is rotatably engaged with the outer peripheral portion of the boss portion 5e. The outer peripheral portion of the rotation transmitting member 8 has a convex portion 6 of the inner screw member 6 at a lower portion.
b and a convex portion 8b which engages with the convex portion 5b of the gear member 5 at the upper portion.
Are integrally formed. In the rotation transmitting member 8, at the time of transmitting the rotation, the convex portion 5 b of the gear member 5 abuts on one end surface of the convex portion 8 b, and the convex portion 6 b of the inner screw member 6 contacts the other end surface.
The rotation of the gear member 5 is transmitted when the projection 5b of the gear member 5 presses the projection 6b of the inner screw member 6 via the projection 8b of the rotation transmitting member 8.

Next, the operation of the apparatus will be described. 4 and 5 are explanatory diagrams of the operation of the embodiment of the present invention.

FIG. 4A shows that the projection 5b of the gear member 5 is in contact with one end of the projection 8b of the rotation transmitting member 8 and the projection 5b of the gear 5 is in contact with the other end. The state where the part 5 rotates in the direction of the arrow B ₁ and the rotation of the gear part 5 is transmitted to the inner screw member 6 via the rotation transmitting member 8 is shown. 4 then from the state of (A), rotating the gear unit 5 reverses the rotation direction of the motor 1 in the arrow B ₂ direction protrusions 5b of the gear member 5 starts to rotate in the arrow B ₂ direction. At this time, since the gear member 5, the rotation transmitting member 8, and the inner screw member 6 are rotatably connected to each other, the convex portion 5b
The engagement between the convex portion 8b is released, only the gear member 5 is rotated in the arrow B ₂ direction. When the gear member 5 rotates about 360 °, the convex portion 5b of the gear member 5 passes over the convex portion 6b of the inner screw member 6 as shown in FIG. impinges on the same end face abutting an end surface of the projection 6b, by the convex portions 5b of the gear member 5 presses the convex portion 8b of the rotation transmission member 8 in the arrow B ₂ direction, FIG. 4
5D, the rotation transmission member 8 starts rotating in synchronization with the rotation of the gear member 5. As shown in FIG. At this time, the gear member 5 and the rotation transmitting member 8 are rotatably connected to each other, and the rotation transmitting member 8 rotates in a direction of releasing the engagement between the convex portions 8b and the convex portions 6b. Remains stationary without any addition. When the gear member further rotates, as shown in FIG.
The projection 8 b of the rotation transmitting member 8, which is pushed by the colliding member, collides with the projection 6 b of the inner screw member 6.

Further, when the gear member 5 and the rotation transmitting member 8 rotate, as shown in FIG.
b, the projection 8b of the rotation transmitting member 8 presses the projection 6b of the inner screw member 6, and the inner screw member 6
The rotation transmission member 8 starts rotating in synchronization with the rotation of the gear 5. When the inner screw member 6 starts rotating, the output shaft 7 screwed to the inner screw member 6 becomes the guide convex portion 7.
because it has been rotated blocked by b, the output shaft 7 is linearly moved upward (arrow A ₁ direction) (rise). Further, to rotate the motor 1 as shown in FIG. 5 (D) in the opposite direction to the case of linear motion output shaft 7 downward (arrow A ₂ direction).

When the motor 1 is rotated in the reverse direction, the gear member 5 rotates in the reverse direction via the pinion 4, and when the gear member 5 rotates approximately 360 ° as shown in FIG. As shown in (B) and (C), it passes over the convex portion 6b of the inner screw member 6 and contacts the convex portion 8b of the rotation transmitting member 8 from the same end surface as the contact surface of the convex portion 6b of the inner screw member 6. contact to rotate the rotation transmitting member 8 in the arrow B ₁ direction.
At this time, the inner screw member 6 does not rotate because the rotation transmitting member 8 rotates in the direction in which the protrusion 8b is released from the protrusion 6b, and the inner screw member 6 remains stationary at that position.

When the rotation transmitting member 8 is rotated by about 360 ° with no load by the gear member 5, the convex portion 8b of the rotation transmitting member 8 reverses to the convex portion 6b of the inner screw member 6 as shown in FIG. It collided from the side, to rotate the inner screw member 6 in the arrow B ₁ direction. Inner screw member 6 has arrow B
The output shaft 7 and rotates in _one direction to linear motion downwards (A ₂ direction) (downward).

As described above, when the output shaft 7 is forcibly stopped by the guide projections 7b by coupling the gear member 5 and the inner screw member 6 via the rotation transmitting member 8, the motor is problematic. The tightening torque applied to the inner screw member 6 and the output shaft 7 by the inertia force is not less than the maximum torque of the motor 1 until the rotation of the motor 1 becomes stable, and the convex portion 5b of the gear member 5 is rotated. By rotating the convex portion 8b of the rotation transmitting member 8 synchronously and colliding with the convex portion 6b of the inner screw member 6 and obtaining a torque equal to or greater than the loosening torque by the impact force at that time, the inner screw member 6 and the output are output. The tightening with the shaft 7 is released, the inner screw member 6 is started to rotate, and the output shaft 7 can be linearly moved. The required loosening torque can be obtained with a relatively simple configuration of a gear member having a convex portion, an inner screw member having a convex portion, and a rotation transmitting member having a convex portion that engages with the convex portions. An actuator having a structure for stopping the output shaft can be reliably realized at low cost.

[0033]

As described above , according to the present invention, a gear member is provided.
Rotation angle sufficient to hit the female thread member
The motor is in a stable rotation.
The screw member can be driven and the gear member has sufficient
Impact on the female thread member after obtaining
By tightening the female thread member and the male thread member by applying force
Since torque greater than the mounting torque can be obtained,
The screws remain small and the female and male threads are securely tightened.
It has features such as being able to be released. Also, according to the present invention,
If the first and second projections and the rotation transmitting member are on the same circumference,
It has the advantage that the mechanism can be miniaturized.
You.

[Brief description of the drawings]

FIG. 1 is a sectional view of an embodiment of the present invention.

FIG. 2 is a perspective view of a main part of one embodiment of the present invention.

FIG. 3 is an exploded perspective view of a main part of one embodiment of the present invention.

FIG. 4 is an operation explanatory diagram of one embodiment of the present invention.

FIG. 5 is an operation explanatory view of one embodiment of the present invention.

FIG. 6 is an operation explanatory diagram of one embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Motor 2 Storage case 3 Circuit board 4 Pinion 5 Gear member 5b, 6b, 8b Convex part 6 Inner screw 7 Output shaft 8 Rotation transmission member

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁶ , DB name) F16H 19/02 F16H 25/20

Claims (1)

(57) [Scope of request for utility model registration] 1. An output shaft is formed by forming a threaded portion on the outer periphery of an output shaft, screwing a female threaded portion with the male threaded portion, and rotating the female threaded portion in accordance with rotation of a motor. An actuator for reciprocating movement, wherein the female screw portion is formed on the inner peripheral side and a first convex portion is formed on the outer peripheral side, and a female screw member rotating about the output shaft; and the first convex portion Abuts the first convex portion on the same circumference as
A second convex portion formed so as to be displaced in the axial direction of the output shaft so as not to be rotatable with respect to the female screw member, and having an outer periphery engaged with the motor; A gear member that rotates about the output shaft in accordance with the rotation of the first and second protrusions on the same circumference as the first protrusion and the second protrusion.
The first convex portion and the second convex portion can collide with each other;
Centering on the output shaft with respect to the internal thread member and the gear member
At a predetermined angle, and at least the second
In order to apply an impact force to the second convex portion when colliding with the convex portion
An actuator comprising: a rotation transmitting member configured as described above.