JPH0512770Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] The present invention is suitable for detecting an overspeed state by operating a limit switch or the like when the rotational speed of a rotating body exceeds a set value. The present invention relates to an actuator for detecting rotational speed that can be used for.

[Prior Art] This type of actuator is attached to a rotating shaft of a gearbox, for example, and is used when a limit switch is switched to cut off the drive power when an overspeed condition occurs. There are some that operate using centrifugal force.
That is, in the conventional type, an actuator is provided on a body that rotates with a rotating shaft or the like so that it can be operated between a standby position and an operating position, and this actuator is biased toward the standby position by a spring, and the actuator is biased toward the standby position by a spring. The actuator is configured to be able to urge the actuator toward the actuation position by centrifugal force acting on the flyweight or the like due to rotation of the body.

[Problems to be solved by the invention] However, with such a configuration, as the centrifugal force increases, the actuator gradually moves toward the operating position while resisting the biasing force of the spring. . Therefore, there is a problem in that it is difficult to set the limit switch or the like to accurately switch the moment the rotational speed of the rotary shaft or the like exceeds a target value.

In order to solve this conventional problem, the actuator, which exerts a force that pushes the body in the direction of its rotational axis, is locked in a standby position with a lock pin, etc., so that the rotation speed of the body reaches a specified rotation speed. sometimes,
A mechanism has been proposed in which the lock pin is pulled out by centrifugal force to release the locked state, thereby causing the actuator to suddenly pop out in the direction of the operating position.

However, in this method, the lock pin directly contacts the actuator to maintain the locked state of the actuator. To elaborate further,
The lock pin is pressed directly between the actuator and the body in a direction orthogonal to the axis by the axial biasing force acting on the actuator. As a result, a relatively large frictional force acts on the contact surface between the two parts and between the opposing lock pin and the body, so if the coefficient of friction between these parts is not maintained constant, centrifugal force will occur. This results in an unstable force required when the lock pin is pulled out. And due to this,
There was a problem that variations occurred in the detected rotational speed of the rotating body.

An object of the present invention is to provide a rotational speed detection actuator that can reliably solve these problems with a simple configuration and can reliably detect a desired rotational speed.

[Means for Solving the Problems] In order to achieve this purpose, the present invention locks the actuator in a standby position, and when the centrifugal force acting on a specific member exceeds a set value, It is constructed so that the locked state can be released using the centrifugal force. In other words, the rotational speed detection actuator according to the present invention includes a body that rotates together with the rotating body, an actuator provided on the body that can operate from a standby position to an actuation position, and this actuator that is stabilized in the standby position. a first spring for holding; a centrifugal biasing function that biases the actuator in the direction of the operating position using centrifugal force caused by the rotation of the body; a lock pin that can move forward and backward, and a first lock pin that is provided on the lock pin and engages with the actuator.
a second roller that applies a force acting on the lock pin side to the body through the first roller; and a second roller that urges the lock pin toward the actuator and engages the first roller with the actuator. It is characterized by comprising a second spring.

[Function] With such a configuration, the following operations can be performed. First, when the rotation of the body is stopped or the rotation speed is low, the actuator is locked in the standby position. As the rotational speed of the body increases from this state, the force that biases the actuator toward the operating position by the centrifugal biasing mechanism becomes larger than the biasing force of the first spring. The actuator is held at the standby position by the action of a second roller, a second spring, and the like. At this time, the biasing force of the actuator acting on the lock pin side via the first roller is applied to the body via the second roller.

If the rotational speed of the body increases further from this state and exceeds the preset value,
The lock pin is pulled out by centrifugal force to release the locked state, and the actuator is moved all at once from the standby position to the operating position by the urging force of the centrifugal urging mechanism. Furthermore, the frictional resistance force that acts when the lock pin is pulled out is suppressed to an extremely small value due to the rolling motion of the first roller and the second roller. Therefore, by snap-action-like operation of the actuator, switching of the limit switch, etc. can be clearly performed at the target set rotational speed.

On the other hand, when the rotational speed of the body decreases, the biasing force of the centrifugal biasing mechanism decreases, so that the actuator returns toward the standby position due to the biasing force of the first spring, and is locked again in that position by the lock pin or the like in the same manner as described above.

[Example] Hereinafter, an example of the present invention will be described with reference to the drawings.

FIG. 1 shows a plan view of the rotational speed detection actuator according to the present invention, and FIG. 2 shows the −-
The vertical cross-sectional view in Figure 3 is the same as - in Figure 1.
A vertical cross-sectional view is shown between the two. This rotational speed detection actuator is used by being attached to the rotating shaft (not shown) of a gearbox, which is a rotating body.
As shown in the drawings, it has a disc-shaped body 1. A boss portion 2 that is fitted onto one end of the rotating shaft is provided at the center of the end of the body 1, and a cylindrical protrusion portion 3 is formed at the center of the body 1 on the side opposite to the boss portion. A push rod 4, which is an actuator, is fitted inside it. The push rod 4 has a cylindrical shape, and when the body 1 rotates, it moves to the second position.
The rotation axis l of the body 1 is located between the standby position A indicated by a solid line in FIG.
It is possible to move back and forth in the direction. A limit switch (not shown), which is switched by being pressed by the outer end 4a of the push rod 4, is arranged near the operating position B of the push rod 4. Based on the opening and closing of this limit switch, the rotation shaft to which the actuator is mounted is adjusted. Circuits such as a driving power source are designed to be switched on and off. Further, an annular locking collar 4c is provided at the inner end 4b of the push rod 4.
is formed, and a stepped portion 4d is provided in the intermediate portion. A first coiled spring 5 is wound around the push rod 4 and is interposed between the stepped portion 4d and the tip of the protrusion 3. is urged inward to stably hold it at the standby position A.

On the other hand, a centrifugal biasing mechanism 7 is provided on an extending portion 6 that integrally extends from both sides of the protruding portion 3 toward the outer edge of the body 1 . The centrifugal biasing mechanism 7 is for moving the push rod 4 outward by using the centrifugal force _F1 generated by the rotation of the body 1. A pair of flyweights 8 arranged symmetrically with respect to each other are pivotally supported on the body 1 via hinge pins 9. When centrifugal force _F1 acts on the flyweight 8 and the distal end side of the flyweight 8 opens outward with the hinge pin 9 as a fulcrum, an arm integrally extends from the base end of the flyweight 8. 8a and the inner end 4b of the push rod 4.
is configured so that it can be pressed outward against the biasing force of the first spring 5.

Further, the body 1 is integrally provided with another extension part 10 that is orthogonal to the extension part 6, and a holding hole 11 that is orthogonal to the rotation axis l is formed in this extension part 10. A cylindrical lock pin 12 that can move forward and backward in a direction perpendicular to the rotational axis l into this holding hole 11
has been inserted. The tip 1 of this lock pin 12
2a is provided with a first roller 13 that engages with the locking collar 4c of the push rod 4. The first roller 13 is connected to the tip 12 of the lock pin 12.
The lock pin 12 is mounted in a notch 12b formed in the direction of the rotation axis l, and its rotation surface 13a protrudes slightly from the lower end surface 12c and the tip surface 12d of the tip 12a, and rolls in the direction of the axis m of the lock pin 12. Possibly supported by a bin 14. This first roller 13
Above, a second roller 15 is installed in the notch 12b in the same way as the first roller 13, for applying a force in the direction of the rotational axis l to the body 1 through the roller 13. ing. Specifically, the rotating surface 15a is slightly protruded from the upper end surface 12e and the distal end surface 12d of the tip portion 12a, and the rotating surface 15a of the first roller 13
3a, and is supported by a pin 16 so as to be able to roll in the direction of the axis m.

That is, when the push rod 4 is held at the standby position A, these members are in contact with the rotating surface 13a of the first roller 13, the upper surface 4e of the locking collar 4c, and the rotating surface 15a of the second roller 15. ,
Furthermore, this rotating surface 15a and the upper surface 1 of the holding hole 11
It is installed so that it is in contact with 1a.

On the other hand, a second spring 17 is wound around the outer periphery of the lock pin 12, which urges the lock pin 12 in the push rod 4 direction and engages the first roller 13 by biting into the locking collar 4C. The ends are connected to the tip 12a and the retainer 1.
It is supported between the inside of 8.

The retainer 18 includes a threaded portion 11 of the holding hole 11.
A cap-shaped member is screwed onto the retaining hole 1 and has a threaded portion 18a formed on its outer periphery.
The second spring 1
7 can be adjusted to a desired value. Further, an opening 18b is provided at the center of the outer end of the retainer 18 so that the lock pin 12 can be slidably supported. The retainer 18 is fixed by bringing the tips of the retainers 19 into contact with each other.

According to this configuration, when the body 1 rotates and centrifugal force _F1 acts on the flyweight 8, a biasing force acts on the arm 8a of the flyweight 8 to move the push rod 4 outward.
As the rotational speed of the body 1 increases, its biasing force increases and exceeds the biasing force of the first spring 5. However, if the rotational speed is less than the set value, the push rod 4 It is held at the standby position A by being locked by the first roller 13, the second roller 15, etc.

Then, when the rotational speed of the body 1 further increases and exceeds the set value, the locked state is released. That is, when the centrifugal force _F2 acting on the lock pin 12 etc. exceeds the biasing force of the second spring 17, the lock pin 12 moves outward, and the first roller 13 at its tip 12a engages with the push rod 4. It will come off as if being pulled out from the stop flange 4c. At this time, the push rod 4 is instantaneously moved from the standby position A to the operating position B by the urging force received from the flyweight 8. As a result, the outer end 4a of the push rod 4
The limit switch, which is placed opposite to the , will also be switched instantaneously.

On the other hand, when the rotational speed of the body 1 falls below a certain level, the biasing force of the first spring 5 causes the push rod 4 to return to the original standby position A, and is again locked by the lock pin 12, first roller 13, etc.

Therefore, with such a configuration, when the lock pin 12 is pulled out to release the lock state, the shaft generated between the push rod 4 and the lock pin 12, and between the lock pin 12 and the body 1, etc. It becomes possible to release the locked state without generating almost any frictional force in the direction of the center m. As a result, the outward pulling force of the lock pin 12 becomes constant, and the push rod 4 can be clearly actuated in a snap-action manner when the rotational speed of the body 1 reaches a set value.

In addition, by screwing the retainer 18 back and forth, the deflection force of the second spring 17 can be changed to operate the push rod 4 at a desired rotational speed. Moreover, the retainer 18 has a set screw 19
Since the retainer 19 is fixed by the retainer 19, it is possible to prevent the retainer 19 from moving due to vibrations during operation and causing errors in operation.

Note that the rotational speed detection actuator according to the present invention is of course not limited to the embodiments described above, and for example, as schematically shown in FIG. It is also possible to use Also, in such a case,
Rollers 113 and 115 corresponding to the first roller and second roller described above are provided in the vertical direction, and a pair of rollers 116 and 117 are also provided in a direction perpendicular to these rollers 113 and 115, so that the lock pin 112 is attached to the body. It may be held.

[Effects of the invention] As explained above, according to the invention, the contact between the locking flange of the actuator and the lock pin and the contact between the lock pin and the body are made as rolling contact by rollers, so that the detected rotational speed is It is possible to substantially avoid the generation of frictional force that causes variations in the temperature. As a result, when the rotational speed of the rotating body reaches the target set value, it is possible to accurately operate the actuator in a snap-action manner, making it possible to clearly perform switching and other operations. Therefore, it is possible to provide an actuator for detecting rotational speed.

[Brief explanation of the drawing]

1 to 4 show an embodiment of the present invention,
Figure 1 is a plan view, Figure 2 is a - in Figure 1.
3 is a cross-sectional view taken from FIG. 1, FIG. 4 is a perspective view showing a main part, and FIG. 5 is a perspective view showing another embodiment of the same main part. 1... Body, 4... Actuator (push rod), 4c... Locking collar, 5... First spring,
7...Centrifugal biasing mechanism, 8...Fly weight, 1
2... Lock pin, 13... First roller, 15
...Second roller, 17...Second spring,
18...retainer.

Claims (1)

[Scope of utility model registration request] A body that rotates together with the rotating body, an actuator provided on the body that can operate between a standby position and an operating position, a first spring that stably holds the actuator in the standby position, and a first spring that stably holds the actuator in the standby position; a centrifugal biasing function that biases the actuator in the direction of the actuation position using the centrifugal force generated; a lock pin that is movable back and forth in a direction perpendicular to the rotational axis of the body; a first roller that engages with the actuator, a second roller that applies a force acting on the lock pin side to the body through the first roller, and a second roller that urges the lock pin toward the actuator and An actuator for detecting rotational speed, comprising a second spring that engages the roller with the actuator.