JP2000240680A - Torque limitter and hoisting accessory with integrated torque limitter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To transmit the entire rotating torque of a driving means in one directional rotation and limitedly transmit the rotating torque of the driving means in the other directional rotation by performing the transmission of the entire drive torque of the driving means by a cam clutch and the limited transmission of the rotating torque by a friction board. SOLUTION: Since a friction force as a cam 9 is fallen works when the minor diameter part 1a of a hub 1 rotates clockwise, a clearance is formed between the surface of the cam 9 and the inner surface of a sprocket 16, and the rotating torque of a geared motor 15 is not transmitted to the sprocket 16 through a cam clutch 8. Since a friction force as the cam 9 is raised works, conversely, when the minor diameter part 1a of the hub 1 rotates counterclockwise, all the cams 9 make contact with the inner surface of the sprocket 16 as they are pressed thereto, and the sprocket 16 is rotated integrally with the hub 1. Therefore, the rotating torque of the geared motor 15 is entirely transmitted to the sprocket 16 through the cam clutch 8.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a torque limiter, and more particularly, to transmitting the entire torque of a driving means to rotation of a rotating shaft in one direction, and applying the rotating torque of the driving means to rotation of the rotating shaft in the other direction. The present invention relates to a torque limiter that transmits data in a limited manner and a hanger incorporating the torque limiter.

[0002]

2. Description of the Related Art When a slab or a coil is moved by a ceiling crane in an ironworks, a hanging tool mounted on the ceiling crane is used. FIG. 2 shows an example of such a hanger. FIG. 2 is a front view of the hanger, and a hanger, such as a slab or a coil, is lifted by a pair of arms 21 with both sides thereof lifted and carried.

A pair of arms 21 is provided with a nut 24 screwed to a screw shaft 23 provided in a horizontal direction on a horizontal support member 22 of a hanging tool.
When 3 rotates in one direction, they approach each other to grasp the load, and when they rotate in the other direction, they can separate and unload the load.

[0004] The rotation of the screw shaft 23 is performed by transmitting a driving force of an electric motor to a sprocket 25 provided at one end of the screw shaft 23. The driving mechanism of the screw shaft 23 will be described with reference to FIG. The rotation of the screw shaft 23 causes the driving force of the geared motor 26 to move between the sprocket 27 provided on the rotating shaft 26a of the geared motor 26 and the sprocket 25 provided at one end of the screw shaft 23. This is carried out by transmitting the power to the screw shaft 23 by the driven drive chain 28 that has been wound around.

When an excessive pressing force is applied to the arm 21 when the load is gripped by the above-described hanging tool, a flaw is generated on the gripped portion by the arm claw 21a. Normally, the gear should be
A torque limiter 29 is provided on a rotating shaft 26a of the motor 26 so that a rotating torque exceeding a predetermined rotating torque is not transmitted to the screw shaft 23.

FIG. 4 is a side view showing the structure of a conventional torque limiter 29. The torque limiter 29 is fixed to the rotary shaft 26a (fixed to a key groove by a key) to transmit the rotational torque of the geared motor 26 to the screw shaft 23 via the sprocket 27. Hub 31, a sprocket 27 slidably fitted in a small diameter portion 31 a of the hub 31, friction plates 32 arranged on both side surfaces of the sprocket 27, and the friction plate 32
A friction plate presser 33 for pressing the flange portion 31b and both side surfaces of the sprocket 26, a disc spring 34 for applying a pressing force to the friction plate press 33, a disc spring press 35 for pressing the disc spring 34, and a hub. 31 small diameter portion 31a
And an adjustment bolt 37 screwed to the nut 36.

In this torque limiter, the rotational torque of the geared motor 26 is applied to the friction plates 32a and 32b.
Is transmitted to the sprocket 27 and, consequently, the screw shaft 23 by frictional force. Flange 31 of hub 31
The frictional force generated between the spring b and the side surface of the sprocket 27 is generated by the pressing force of the disc spring 34 pressing the friction plate holder 33, and the pressing force of the disk spring 34 is
Can be adjusted by adjusting the position with the adjustment bolt 37.

As described above, in the conventional torque limiter 29, since the rotational torque of the geared motor 26 is transmitted to the screw shaft 23 via the friction plate 32, the friction acting on the friction plate 32 If the force is adjusted to a frictional force that does not cause flaws in the suspended load, the hub 3 will not be able to transmit excessive rotational torque to the screw shaft 23.
1 slips between the friction plate 32 and the excessive rotation torque is not transmitted.

[0009]

However, the above-mentioned conventional torque limiter has the following problems.

When a load is gripped, an excessive pressing force does not act on the load, so that the load works effectively. However, the screwing state between the screw shaft and the nut of the arm causes play due to wear of the mechanical system or the like. In such a state, swelling due to an increase in sliding resistance or the like occurs, and when the load is released, the rotational torque increases.

As a result, the torque limiter operates, and the
The system will not open and operations will have to be stopped.

As a countermeasure, it is conceivable to adjust the frictional force of the torque limiter. However, it is necessary to set the value for each hanging tool, and it is difficult to set the value to an appropriate value. .

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems of the prior art, and can transmit the full rotation torque of the driving means when rotating in one direction, and can transmit the torque when rotating in the other direction. It is an object of the present invention to provide a torque limiter capable of transmitting a rotational torque of a driving means while limiting the torque, and a hanger incorporating the torque limiter.

[0014]

The torque limiter according to the present invention transmits the rotational torque of the driving means to the rotating shaft, and transmits the full rotational torque of the driving means to one-way rotation. With respect to the rotation in the direction, the rotation torque of the driving means is limited and transmitted.

Further, the transmission of the entire driving torque of the driving means is performed by a cam clutch, and the limited transmission of the rotational torque is performed by a friction plate.

Further, a hanging device incorporating the torque limiter according to the present invention has the torque limiter incorporated in an arm opening / closing mechanism.

By incorporating this torque limiter into the lifting device, the rotation torque transmitted to the screw shaft for closing the arm so as not to apply an excessive pressing force to the load when grasping the load is limited. Full rotation torque can be transmitted to the screw shaft that opens the arm.

Therefore, the load is not damaged, and the operation is not stopped without opening the arm.

[0019]

Embodiments of the present invention will be described with reference to the drawings. FIG. 1 is an explanatory view of a torque limiter according to an embodiment of the present invention. FIG. 1 (a) is a side view of the torque limiter, and FIG. 1 (b) is a view taken along the line AA of FIG. 1 (a). .

This torque limiter is a geared motor 1
In order to transmit the rotation torque of No. 5 to a rotation shaft such as a screw shaft, the hub 1 is fixedly attached to the rotation shaft 15a of the geared motor 15, and is fitted into the small diameter portion 1a of the hub 1. The sprocket 16, the friction plates 2 arranged on both sides of the sprocket 16, the friction plate holder 3 for pressing the friction plate 2 against the flange portion 1 b of the hub 1 and both sides of the sprocket 16, and the pressing force on the friction plate holder 3 Disc spring 4 for imparting a spring, and a disc spring retainer 5 for holding the disc spring 4
, A nut 6 fixed to the small-diameter portion 1a of the hub 1, an adjusting bolt 7 screwed to the nut 6, and the small-diameter portion 1a of the hub 1.
And the cam clutch 8 disposed between the outer surface of the sprocket 16 and the inner surface of the sprocket 16.

This torque limiter operates in the same manner as the conventional torque limiter described with reference to FIG. 3 except that the cam clutch 8 is mounted. Is omitted, and only the cam clutch 8 will be described.

As shown in FIG. 1B, the cam clutch 8 includes a plurality of cylindrical cams 9 arranged at equal intervals between the outer surface of the small diameter portion 1a of the hub 1 and the inner surface of the sprocket 16.
In order to prevent the cams 9 from falling apart, a ring-shaped spring 10 penetrating through the center of all the cams 9 and pressing the cams 9 against the outer surface of the small-diameter portion 1a of the hub 1, and the distance between the adjacent cams 9 And a distance holder 11 for keeping the distance constant.

The portion of the cam 9 that is in contact with the outer surface of the small diameter portion 1a of the hub 1 and the portion that is in contact with the inner surface of the sprocket 16 have a smooth convex shape toward each surface. The dimension W between the most convex parts of
Is larger than the dimension w of the gap between the outer surface of the small diameter portion 1a and the inner surface of the sprocket 16. Therefore, the cams 9 are arranged in a state of being inclined obliquely in the gap and in a state where all the cams 9 are inclined in the same direction (in the figure, they are inclined to the left).

When the small-diameter portion 1a of the hub 1 rotates clockwise while the cams 9 are arranged as shown in FIG. 1B, the outer surface of the small-diameter portion 1a of the hub 1 and the cam 9 Since a frictional force acts on the surface of the sprocket 16 to cause the cam 9 to fall, a gap is formed between the surface of the cam 9 and the inner surface of the sprocket 16. 8 is not transmitted to the sprocket 16. That is, during this rotation, the gear motor 1
5 is transmitted only through the friction plate 2.

Conversely, when the small-diameter portion 1a of the hub 1 rotates counterclockwise, a frictional force that causes the cam 9 acts between the outer surface of the small-diameter portion 1a of the hub 1 and the surface of each cam 9. Therefore, all the cams 9 come into contact with the inner surface of the sprocket 16 so as to be pressed, and the sprocket 16 rotates integrally with the hub 1. Therefore, the rotational torque of the geared motor 15 is transmitted through the cam clutch 8 All sprockets 1
6 is transmitted.

Therefore, if the above-described torque limiter of the present invention is incorporated in the arm opening / closing mechanism of the hoist so that the cam clutch 8 operates when the arm is opened, the hub 1 can be connected to the flange surface 1b. Even if a slip occurs between the friction plate 2 and the sprocket 16, the small diameter portion 1a of the hub 1 rotates together with the sprocket 16, so that the arm cannot be opened and the operation is stopped. Absent.

[0027]

According to the present invention, there is no flaw in the load due to the arm of the hanging tool, and the operation can be stably performed without the arm being opened.

[Brief description of the drawings]

FIGS. 1A and 1B are explanatory diagrams of a torque limiter according to an embodiment of the present invention, wherein FIG. 1A is a side view of the torque limiter, and FIG.

FIGS. 2A and 2B are explanatory diagrams of an example of a hanging tool, wherein FIG. 2A is a front view of the hanging tool, FIG. 2B is a side view of the hanging tool, and FIG.
It is an arrow view.

FIG. 3 is a side view showing a configuration of a conventional torque limiter.

FIG. 4 is a side view showing a configuration of a conventional torque limiter.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Hub 2 Friction plate 3 Friction plate holder 4 Belleville spring 5 Belleville spring retainer 6 Nut 7 Adjusting bolt 8 Cam clutch 9 Cam 10 Spring 11 Distance holding device 15 Gear motor 16 Sprocket

Continued on the front page (72) Inventor Munetsugu Yuki 1-2-1, Marunouchi, Chiyoda-ku, Tokyo F-term (reference) 3F004 AA02 AB08 AG08 EA03 EA09

Claims (3)

[Claims] When transmitting the rotation torque of the driving means to the rotating shaft, the rotation torque of the driving means is transmitted for rotation in one direction, and the rotation torque of the driving means is transmitted for rotation in the other direction. Characterized in that the torque limiter is configured to transmit the power in a limited manner. 2. The torque limiter according to claim 1, wherein transmission of the entire driving torque of said driving means is performed by a cam clutch, and transmission of limited rotational torque is performed by a friction plate. 3. A lifting device comprising the torque limiter according to claim 1 incorporated in an arm opening / closing mechanism.