JP7317259B1 - shaft brake - Google Patents

Abstract

[PROBLEMS] To provide a collet chuck type shaft brake capable of reliably preventing parts from falling off due to over-rotation of an operation nut during unlocking without increasing the number of parts. SOLUTION: A slide sleeve-shaped collet 20 is inserted into a shaft insertion hole of a housing 10, and the collet 20 is slid in a central axis direction by an operation nut 30 screwed to the housing 10. - 特許庁The inner tapered portion 11 of the housing 10 and the outer tapered portion 21 of the collet 20 are fitted together. The inner tapered portion 11 and the outer tapered portion 21 are of a pull-out lock type in which the outer tapered portion 21 of the collet 20 is contracted and deformed to lock the shaft as the collet 20 is pulled out from the shaft insertion hole of the housing 10 . be. [Selection diagram] Fig. 1

Description

The present invention relates to a collet chuck type shaft brake used as various stoppers for restraining axial and/or circumferential relative movement with respect to a shaft, such as a height adjusting mechanism for a tool holder or a table with legs.

FIG. 4 shows a conventional typical structure of a collet chuck type shaft brake. As shown in the figure, the conventional collet chuck type shaft brake includes, as main components, a sleeve-shaped housing 10, a sleeve-shaped collet 20 slidably inserted into the housing 10, and the housing 10. It has a ring-shaped operating nut 30 attached to one end, and the shaft to be locked is passed through the inside thereof.

The housing 10 and the operation nut 30 are made of a rigid body such as metal, and the housing 10 has an inner tapered portion 11 in the inner shaft insertion hole. The collet 20 is made of an elastic material such as resin, and has an outer tapered portion 21 which is fitted with the inner tapered portion 11 of the housing 10 and which can be expanded and contracted. The operation nut 30 is screwed into a part of the housing 10 from one end side of the shaft insertion hole of the housing 10, and reciprocates the collet 20 in the central axis direction by rotating operation. For this reason, the collet 20 and the operating nut 30 are connected in the central axis direction.

The relationship between the inner tapered portion 11 of the housing 10 and the outer tapered portion 21 of the collet 20 is determined by screwing the operation nut 30 into the housing 10 toward the base end side (on the mounting base side of the housing 10, toward the bottom in FIG. 4). As a result, the collet 20 is inserted deep into the shaft insertion hole of the housing 10, and the outer tapered portion 21 is pushed into the inner tapered portion 11 of the housing 10, whereby the diameter of the outer tapered portion 21 is reduced and deformed. Tighten and lock the shaft. That is, the collet chuck type shaft brake here is of the push lock type.

In order to achieve this, the inner surface tapered portion 11 of the housing 10 is partially formed in a part of the housing 10 in the central axis direction, and the inner surface gradually expands in diameter from the proximal side to the distal side. there is Further, the collet 20 has a plurality of elastic tongues 22 formed by dividing a part of the front end in the insertion direction into a plurality of pieces in the circumferential direction. Corresponding to the inner surface tapered portion 11 of 10, the diameter is gradually increased from the front end side in the insertion direction toward the rear end side in the insertion direction.

Thus, as the operation nut 30 is screwed, the collet 20 is pushed into the housing 10, whereby the outer surface tapered portion 21, that is, the plurality of elastic tongues 22 are deformed to reduce in diameter, and the shaft passing therethrough is deformed. is locked.

In such a conventional collet chuck type shaft brake, various devices have been devised in terms of mechanical structure (Patent Document 1), but as an operation method, it is unified to the above-mentioned push lock type. That is, when the shaft is locked, by rotating the operating nut 30 clockwise toward the housing 10, the collet 20 is pushed into the housing 10 and the diameter of the outer tapered portion 21 is reduced. On the contrary, when the shaft is unlocked, by rotating the operation nut 30 counterclockwise toward the housing 10, the collet 20 is pulled out from the housing 10, and the outer surface tapered portion 21 is expanded and deformed. .

However, the conventional collet chuck type shaft brake adopting such a push lock type has the following problems due to its operation method. For example, when removing a tool from a tool holder, the operation nut 30 is rotated toward the detachment side with respect to the housing 10 to loosen the restraint on the shaft. , forced to bear an unexpected burden. In order to prevent the operation nut 30 and the collet chuck 20 from coming off due to over-rotation of the operation nut 30, a separate retaining mechanism and drop prevention mechanism are required, which increases the number of parts and increases the manufacturing cost. forced to.

JP-A-2005-066758

SUMMARY OF THE INVENTION An object of the present invention is to provide a collet chuck type shaft brake that can reliably prevent parts from falling off due to over-rotation of an operating nut during unlocking without increasing the number of parts.

In order to achieve the above object, the shaft brake of the present invention includes a housing having a shaft insertion hole through which a shaft to be fixed is inserted and an inner surface tapered portion provided in the shaft insertion hole; A slide sleeve to be inserted, which has an outer tapered portion interfitted with the inner tapered portion, and the collet that locks and unlocks the shaft by expanding and contracting the outer tapered portion by advancing and retracting the slide sleeve. and an operation nut that is screwed into a part of the housing and slides the collet in the advancing and retreating directions by rotating the collet chuck type shaft brake,
The inner tapered portion of the housing and the outer tapered portion of the collet that are fitted together are deformed to reduce in diameter as the collet is pulled out from the shaft insertion hole of the housing and slid in the withdrawal direction. While the shaft is locked by pressing the collet, it is a pull-out lock type in which the shaft is unlocked by expanding and deforming the outer surface tapered portion of the collet as the collet is pushed into the shaft insertion hole of the housing. A feature of the configuration is that there is a

In the shaft brake of the present invention, the operating nut is operated in the disengagement direction to slide the collet in the withdrawal direction from the housing, whereby the diameter of the outer tapered portion of the collet is reduced and deformed to restrain the shaft passing through the inner side. . As this operation proceeds, the outer surface tapered portion undergoes diameter reduction deformation, and the operating force of the operating nut increases, thereby completing the locking operation.

That is, in the shaft brake of the present invention, the so-called loosening operation of operating the operating nut in the disengagement direction increases the tightening force by the outer surface tapered portion of the collet, thereby locking the shaft. Therefore, it is possible to prevent the operation nut and the collet from being separated from the housing at the time of locking. Further, since the operation nut is to be tightened when unlocking, the operation nut and the collet are prevented from coming off at this time as well.

The thread type of the operation nut here is preferably a left-hand thread (reverse thread) that rotates counterclockwise toward the housing. With a left-handed (reverse) thread, the collet is tightened when the operation nut is tightened, so it feels natural and reduces operational errors.

In the shaft brake of the present invention, the operating nut is pushed in the disengagement direction from the housing, and by loosening the collet chuck, the collet chuck is pulled out of the housing and locked. This can be reliably prevented, and there is no need to increase the number of parts.

1 is a partially broken perspective view of a shaft brake showing an embodiment of the present invention; FIG. It is a partially broken exploded perspective view of this shaft brake. It is a vertical cross-sectional view showing the function of this shaft brake, (a) shows an unlocked state, (b) shows a locked state, respectively. FIG. 10 is a vertical cross-sectional view showing the structure of a conventional shaft brake;

An embodiment of the present invention will be described below with reference to FIGS. The shaft brake of this embodiment is used as various stoppers for restraining axial and/or circumferential relative movement with respect to a shaft, such as a height adjustment mechanism for a tool holder or a table with legs.

The shaft brake of this embodiment is of the collet chuck type similar to the conventional shaft brake shown in FIG. It comprises a sleeve-shaped collet 20 and a ring-shaped operating nut 30 attached to the tip of the housing 10, and the shaft to be locked is inserted through the inside of these, which is substantially the same as a conventional shaft brake. is.

Further, the housing 10 and the operation nut 30 are made of a rigid body such as metal, the housing 10 has an inner surface tapered portion 11 in the inner shaft insertion hole, the collet 20 is made of an elastic body such as resin, and the housing 10 The operation nut 30 is located on one end side of the shaft insertion hole of the housing 10, and has an outer tapered portion 21 that can be deformed to expand and contract. 10, and rotating to reciprocate the collet 20 in the direction of the central axis. It is substantially the same as a conventional shaft brake.

Regarding the direction of the housing 10, the mounting base side (lower side in the figure) is called the proximal end side, and the opposite side is called the distal end side. Therefore, the collet 20 is inserted into the shaft insertion hole from the tip side of the housing 10, and the operation nut 30 is screwed into the housing 10 from the tip side of the housing 10. As shown in FIG.

The difference from the conventional shaft brake is the structure of the inner tapered portion 11 of the housing 10 and the outer tapered portion 21 of the collet 20 which are fitted together, and this point will be described in detail below.

The inner surface tapered portion 11 of the housing 10 is formed in a portion of the housing 10 in the central axis direction, specifically, in a portion of the base end side (mounting base side) of the housing 10, and tapers toward the base end side thereof. The inner diameter gradually increases. That is, the inner tapered portion 11 expands toward the base end side of the housing 10 like a trumpet. The collet 20 has a plurality of elastic tongues 22 formed by dividing a part of the front end side in the insertion direction into a plurality of pieces in the circumferential direction. , the diameter gradually increases from the rear end side in the insertion direction toward the front end side in the insertion direction.

In addition, the collet 20 has a collar portion 23 at the end on the rear end side in the insertion direction. On the other hand, the operating nut 30 is a so-called cap nut, and has a circular concave portion 32 on the surface of its flange portion 31 . The collar 23 of the collet 20 fitted into the circular recess 32 and the retaining ring 40 attached to the collet 20 behind the flange 31 prevent the collet 20 from coming off. As a result, the collet 20 and the operating nut 30 are connected in the direction of the central axis in a mutually rotatable state and interlocked.

Next, the operating method and function of the shaft brake of this embodiment will be described.

FIG. 3(a) shows the initial state of the shaft brake. The operation nut 30 is screwed all the way in, and the collet 20 is all the way inserted into the shaft insertion hole of the housing 10 . In this state, the outer tapered portion 21 of the collet 20 is fitted into the inner tapered portion 11 of the housing 10, and the inner surface is a straight circumferential surface having a constant inner diameter over the entire length in the central axis direction. Thereby, the shaft inserted inside the collet 20 is movable in the central axis direction and the circumferential direction. That is, the shaft brake is in the unlocked state.

From this state, the operating nut 30 is rotated in the disengagement direction. Then, as shown in FIG. 3(b), the collet 20 is gradually pulled out toward the distal end of the housing 10. Then, as shown in FIG. As a result, the outer tapered portion 21 of the collet 20 slides from the inner tapered portion 11 of the housing 10 toward the distal end thereof, and is constricted from the outer peripheral side by the inner tapered portion 11 to reduce the diameter, thereby tightening the shaft inserted inside. . Further rotation of the operating nut 30 increases this tightening force and completes the locking operation. At this time, it goes without saying that the shaft brake is designed so that the locking operation is completed before the operating nut 30 comes out of the housing 10 .

Rotating the operating nut 30 in the opposite direction, i.e., the screwing direction, returns the shaft brake to the unlocked state. The operation nut 30 will not come off from the housing 10 regardless of which direction the operation nut 30 is rotated.

Therefore, the separation of the operating nut 30 from the housing 10 and thus the separation of the collet 20 are reliably prevented. Moreover, the number of parts constituting the shaft brake is the same as that of the conventional shaft brake shown in FIG.

The thread type of the operation nut 30 may be a right-handed thread that is screwed by rotating it clockwise toward the housing 10, or a left-handed thread (reverse thread). In the case of a right-handed screw, by rotating the operating nut 30 counterclockwise toward the housing 10, the operating nut 30 moves in the disengagement direction to perform the locking operation. Conversely, in the case of a left-hand thread, the locking operation is performed by rotating the operating nut 30 clockwise toward the housing 10 . From the point of view of work and operation, a left-handed screw (reverse screw), which tightens clockwise and loosens counterclockwise, is more desirable in the present invention because it feels natural and reduces operational errors.

REFERENCE SIGNS LIST 10 housing 11 inner tapered portion 20 collet 21 outer tapered portion 22 elastic tongue piece 23 collar portion 30 operating nut 31 flange portion 32 circular concave portion 40 retaining ring

Claims (2)

A housing having a shaft insertion hole through which a shaft to be fixed is inserted, and an inner tapered portion is provided in the shaft insertion hole; The collet locks and unlocks the shaft by expanding and contracting deformation of the outer tapered portion due to the forward and backward movement of the slide sleeve. A collet chuck type shaft brake comprising an operation nut for sliding the collet in the advancing and retreating direction,
The inner tapered portion of the housing and the outer tapered portion of the collet that are fitted together are deformed to reduce in diameter as the collet is pulled out from the shaft insertion hole of the housing and slid in the withdrawal direction. While the shaft is locked by pressing the collet, it is a pull-out lock type in which the shaft is unlocked by expanding and deforming the outer surface tapered portion of the collet as the collet is pushed into the shaft insertion hole of the housing. Some shaft brakes. A shaft brake according to claim 1, wherein
The thread type of the operation nut is a left-handed (reverse thread) shaft brake that rotates counterclockwise toward the housing.

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