JPS6236977Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a torque limiter that cuts off the transmission of rotational force when an overload is applied.

Conventionally, torque limiters have balls or sloped cams, and when an overload is applied, the thrust force from the balls or slopes cuts off power transmission, but at this time, the balls or sloped cams repeatedly engage and disengage. , a strong torsional vibration torque was generated, damaging the power transmission system and causing discomfort to the driver. Furthermore, the output side of a torque limiter is often used to drive a work machine such as a knife, but when the torque limiter is activated, an abnormal load must be removed without disengaging the clutch, and this work may cause the work machine to suddenly operate, resulting in serious damage. An accident occurred.

Therefore, the present invention provides a locking portion on a sliding member that receives thrust force and interrupts power transmission, and also provides a flyweight with a locking pawl on the input shaft side of the sliding member. It is an object of the present invention to provide a torque limiter in which the locking pawl of the flyweight is locked to the locking portion of the sliding member when the torque limiter is in operation due to the centrifugal force acting thereon, thereby eliminating the above-mentioned drawbacks. That is.

Embodiments of the present invention will be described below with reference to the drawings.

The torque limiter 1, as shown in FIG.
It is arranged between the input shaft 2 and the output shaft 3. The limiter 1 has an intermediate shaft 5 rotatably supported between input and output shafts 2 and 3 by protruding small diameter parts 5a and 5b, and these shafts 2, 3, and 5 are supported by bearings 6 and 6. It has a case 7 that rotatably supports it and covers the entire body. intermediate shaft 5
A spline 5c is formed on the input shaft 2 side of the spline 5c, and a clutch 9 is slidably supported at the tip of the spline 5c. This allows for intermittent operation with the input shaft 2. On the other hand, the output shaft 3 side of the intermediate shaft 5 is a flange 11;
1 has three through holes 13 for housing balls 12 having a predetermined diameter (see FIG. 2). Also, the output shaft 3 faces the flange 11.
A flange 3a is also formed at the end of the flange 3a, and the flange 3a has a number of recesses 15 for receiving the balls 12.
have. The ball 12 is held across the through hole 13 and the recess 15;
The recess 15 is relatively shallow, and the center of the ball 12 is located in the through hole 13, so that both flanges 1
When 1 and 3a rotate relative to each other, a thrust force acts on the ball 13 and the ball 13 is recessed into the through hole 13 portion. Furthermore, a bracket 16 is disposed at the base end portion of the spline 5c of the intermediate shaft 5, the sliding position of which is regulated by a retaining ring 17. ball 12
A presser plate 19 is slidably supported, and a spring 20 of a predetermined strength is compressed between the bracket 16 and the presser plate 19. Furthermore, two fly weights 21, 2 are attached to the bracket 16.
1 is pivotally supported by a pin 22, and the weight portions 21a of these weights 21 are urged toward each other by a spring 25 via a pin 23, as shown in detail in FIG. The end is a locking pawl 21b, and the locking pawl 21b is used when the ball 12 is inserted into the through hole 13 of the flange 11, that is, when the power transmission between the intermediate shaft 5 and the output shaft 3 is cut off. , can be locked in a locking groove 19a formed in the ball holding plate 19.

Since this embodiment has the above-described configuration, under normal power transmission conditions, the rotation of the input shaft 2 is transmitted to the intermediate shaft 5 of the torque limiter 1 via the clutch 9, and further transmitted to the output shaft 3 via the ball 12. has been communicated to. At this time, as the intermediate shaft 5 rotates, the flyweight 21 also rotates via the bracket 16, and centrifugal force acts on the weight portion 21a, which attempts to expand against the spring 25, but the locking claw 21b is in contact with the land portion 19b of the holding plate 19, and the weight 21 is prevented from expanding. Then, when an overload occurs on the output shaft 3,
As shown in FIG. 4, a force is generated between the flange 3a of the output shaft and the flange 11 of the intermediate shaft, and a thrust force based on the force causes the ball 12 to resist the spring 20 and rotate the flange 11 of the intermediate shaft. The intermediate shaft 5 and the output shaft 3 are inserted into the through hole 13, and power transmission between the intermediate shaft 5 and the output shaft 3 is cut off. At the same time, ball 12
As a result, the holding plate 19 is retracted against the spring 20, and due to the centrifugal force acting on the fly weight 21, the locking pawl 21b is locked in the locking groove 19a of the holding plate 19, and the holding plate 19 spring 20
Returns are prevented. As a result, ball 1
2 does not enter the recess 15 intermittently, and generation of torsional vibration torque in the power transmission system is prevented. Then, the driver uses torque limiter 1.
When the operator knows that the clutch has been activated, the operator operates the operating lever 10 to disengage the clutch 9 as shown in FIG. Then, the rotation from the input shaft 2 is not transmitted to the intermediate shaft 5, the rotation of the intermediate shaft 5 decreases, and therefore the centrifugal force acting on the fly weight 21 decreases, and the weight 21 is returned by the spring 25. The locking pawl 21b is removed from the locking groove 19a. Then,
The holding plate 19 is pressed by the spring 20 to project the ball 12 from the through hole 13, and the ball 12 is fitted into the recess 15 of the output shaft flange 3a. At this time, the intermediate shaft 5 rotates slightly due to inertia.
The ball 12 is securely fitted into the recess 15, so that the torque limiter 1 is automatically reset.

Note that in the above embodiment, the ball 12 is held by the holding plate 19.
Although the plate holding the ball 12 may be slidably provided on the intermediate shaft 5, other engaging members such as an inclined cam may be used instead of the ball 12. In short, the thrust It suffices if it can slide in the axial direction in response to force.

As explained above, according to the present invention, the locking portion 19a is provided on the member 19 that slides under thrust force due to overload, and the locking claw 21 is provided on the intermediate shaft 5.
A flyweight 21 having a diameter b is provided, and the locking claw 21b of the flyweight is locked to the locking portion 19a of the sliding member 19 while the torque limiter 1 is activated by the centrifugal force acting on the flyweight. With this structure, when the torque limiter is activated, the balls 12, etc. are held in a disengaged position from the recess 15, etc. of the output shaft 3, and the balls, etc. are prevented from being repeatedly engaged and disengaged, and torsional vibration torque is applied to the power transmission system. can be prevented from occurring. Furthermore, when the clutch 9 is disengaged and the power transmission to the intermediate shaft 5 is cut off,
The centrifugal force acting on the fly weight 21 decreases,
The locking of the weight 21 by the locking pawl 21b is released and the torque limiter 1 is automatically reset, and since the clutch 9 is made of a separate member from the ball 12 etc. which is the engagement part of the torque limiter 1,
The clutch 9 can be easily operated with light operating force. Therefore, the driver disengages the clutch 9 before removing the abnormal load, which prevents the output-side work equipment from suddenly operating and a serious accident. Even if you forget to turn off the clutch 9 and remove the abnormal load, the clutch 9
Since the torque limiter 1 will not be reset unless the centrifugal force of the fly weight 21 is eliminated by cutting off the torque limiter 1, the work machine will not suddenly start driving, and it is safe.

Note that the clutch 9 does not need to be disposed inside the torque limiter 1; it is sufficient to dispose it on the input shaft 2 side. Therefore, the clutch 9 may be a main clutch, and in this case, the intermediate shaft 5 is connected to the torque limiter 1.
means the axis on the input side.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing a torque limiter according to an embodiment of the present invention, FIG. 2 is a sectional view thereof along the - arrow, and FIG. 3 is a sectional view thereof along the - arrow.
FIG. 4 is a cross-sectional view showing the torque limiter in operation, and FIG. 5 is a cross-sectional view showing the torque limiter in a reset state after the clutch is disengaged. 1...Torque limiter, 2...Input shaft, 3...
...Output shaft, 5...Input shaft side (intermediate shaft), 12...
Thrust force receiving member (ball), 19...Sliding member (pressing plate), 19a...Locking part (concave groove), 21...
...Fly weight, 21b...Latching claw.

Claims (1)

[Scope of utility model registration request] In a torque limiter having a sliding member that slides in the axial direction in response to a thrust force due to an overload and cuts off power transmission, a locking portion is provided on the sliding member and the locking portion is locked on the input shaft side of the sliding member. A flyweight having a claw is provided, and the locking claw of the flyweight is locked to the locking portion of the sliding member with the sliding member cutting off power transmission by centrifugal force acting on the flyweight. A torque limiter configured to