JPH05162009A - Ball type chuck device - Google Patents

Abstract

PURPOSE:To make the center axis of a holder coincide with that of a member to be chucked easily by slidably fitting an outer cylinder cover onto a holder and forming a taper which slides a chucking ball in the center direction of an insertion hole in the inner peripheral surface of the outer cylinder cover. CONSTITUTION:A member 2 to be chucked is inserted into an insertion hole 3 with a tapered part 6c meeting a chucking ball 5, and an outer cylinder cover 6 is moved in the direction of the member 2 to be chucked, so that the tapered part 6a moves the chucking ball 5 in the central direction of the insertion hole 3 to press the outer periphery of the member 2 to be chucked in the insertion hole 3 for chucking. At this time, the chucking ball 5 chicks the member 2 to be chucked by even force at regular intervals from at least three directions, so that the center axis of the member 2 to be chucked is made to coincide with that of the holder 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ball type chuck device used for chucking a workpiece, a tool, a measured product or the like in a machine tool, a precision measuring instrument or the like.

[0002]

2. Description of the Related Art Conventionally, as a ball type chuck device,
It is disclosed in Japanese Utility Model Publication No. 62-198026. FIG. 8 shows the ball-type chuck device of the above publication, in which the holder 21 has a holding hole 23 for a chucked member 22 at its tip.
Is formed, and a plurality of through holes 25 for guiding and holding the chuck balls 24 are formed in the holding hole 23. An outer cylinder cover 26 is externally inserted into the holder 21,
A groove 27 is formed on the inner peripheral surface of the outer cylinder cover 26 at a position concentric with the through hole 25, and an elastic member 28 with which the chuck ball 24 guided and held by the through hole 25 abuts is arranged in the groove 27. Has been done. Then, the chucked member 22 having the groove 29 formed concentrically with the through hole 25 is press-fitted into the holding hole 23 of the holder 21 to push up the chuck ball 24, and then by the reaction force of the elastic member 28. The chucked member 22 is chucked and held by the holder 21 when the chucked ball 24 pushed back enters the groove 29.

[0003]

However, in the above-mentioned conventional chuck device, it is necessary that the chucked member 22 has the groove 29 at the concentric position with respect to the through hole 25 when it is press-fitted into the holder 21. Also, although the chucking is performed by the reaction force of the elastic member 28, since the reaction force varies, the chucked member 22 such as a workpiece and the holder 2 are
Since it is difficult to align the central axis with the chuck 1, the chucked member 22 is bent and chucked, which is not suitable for a chucking device such as a measuring instrument that requires accuracy.

The present invention has been made in view of the above-mentioned problems of the prior art. The present invention does not depend on the presence or absence of the groove of the chucked member, and the chucked member is not bent and chucked during chucking. An object of the present invention is to provide a ball type chuck device that can easily cope with a chuck member having a different outer diameter.

[0005]

In order to achieve the above object, a ball type chuck device of the present invention is provided with a holder having an insertion hole for a member to be chucked formed inside the tip, and the inner peripheral surface of the insertion hole. At least three open through-holes are formed at equal intervals, at least one chuck ball is slidably arranged in each through-hole, and the outer cylinder cover is slidably attached to the holder. The outer peripheral cover is fitted with a taper on the inner peripheral surface of the chuck ball so that the chuck ball slides toward the center of the insertion hole.

[0006]

In the above structure, the taper portion is inserted into the insertion hole with the taper portion facing the chucking ball, and the outer cylinder cover is moved toward the chucked member, whereby the taper is chucked. The work ball is moved toward the center of the insertion hole (holder), and the outer peripheral surface of the chucked member in the insertion hole is pressed to be chucked. At this time, the chucking ball chucks the chucked member with equal force in at least three directions at equal intervals, and the chucked member and the central axis of the holder coincide with each other.

[0007]

Embodiment 1 FIGS. 1 to 3 show Embodiment 1 of a ball chuck device of the present invention. FIG. 1 is a central longitudinal sectional view, FIG. 2 is a sectional view taken along the line AA in FIG. 1, and FIG. It is an expanded sectional view of the B section in FIG. In the figure, reference numeral 1 denotes a holder. A male screw portion 1a is formed at the center of the outer peripheral surface of the holder 1, and an insertion hole 3 for a chucked member 2 is formed at the center of the tip.

At the tip of the holder 1, there is formed a through hole 4 which is opened substantially in the middle of the inner peripheral surface of the insertion hole 3 from the outer peripheral surface of the tip of the holder 1. The through hole 4 is formed perpendicularly to the central axis of the insertion hole 3, and is 120 mm centered on the central axis.
It is provided radially at three intervals. A claw portion 4a is formed in the opening of the through hole 4 on the insertion hole 3 side to prevent the chuck ball 5 slidably inserted and arranged in the through hole 4 from falling into the insertion hole 3. There is.

An outer cylinder cover 6 is detachably fitted on the outer peripheral portion of the holder 1. Outer cylinder cover 6 tip inner peripheral surface 6
a is formed to be the same as or slightly larger than the outer diameter of the tip of the holder 1, and the inner peripheral surface connecting from the inner peripheral surface 6a of the tip to the inside is formed with a female screw portion 6b that meshes with the male screw portion 1a of the holder 1. There is. On the opening side of the tip inner peripheral surface 6a, a taper 6c that is widened toward the opening side is formed. When the outer cylinder cover 6 is fastened to the holder 1, the taper 6c is used for chuck balls of the holder 1. 5 is provided at a position where it does not abut.

In this embodiment, the taper 6c is positioned at the chuck ball 5 and the chucked member 2 is inserted into the insertion hole 3 of the holder 1. Then, the outer cylinder cover is turned in the tightening direction of the screws 1a and 1b to bring the tip inner peripheral surface 6a of the outer peripheral cover 6 into contact with the chuck balls 5. At this time, the chuck ball 5 is pushed by the taper 6c surface and slides in the through hole 4 in the insertion hole 3 direction, and presses the outer peripheral surface 2a of the chucked member 2 to chuck the chucked member 2. ..

According to this embodiment, the chuck balls 5 are used.
Presses the outer peripheral surface of the chucked member 2 evenly, so that the chucked member 2 can be chucked in a stable state, and the central axes 5 of the chucked member 2 and the holder 1 can be aligned. It is possible to prevent chucking in a bent state. Further, even if the chuck balls 5 have different outer diameters within the range of the movement of the chuck balls 5 within the through holes 4, the chuck balls 5 can be used.
It is possible to deal with it by exchanging only the holder 1 without exchanging the holder 1 or the like. Further, as shown in FIG. 4, since the chuck outer diameter G is determined by the relationship between the claw distance h and the chuck ball diameter H, the chucked member 2 having any outer diameter can be chucked by changing the above parameters. can do.

[0012]

Second Embodiment FIGS. 5 to 7 show a second embodiment of the ball chuck device of the present invention. FIG. 5 is a central longitudinal sectional view, FIG. 6 is a sectional view taken along the line CC in FIG. 5, and FIG. It is an expanded sectional view of the D section in FIG. Reference numeral 11 in the drawing denotes a holder, and an insertion hole 13 for the chucked member 2 is formed at the center of the tip. At the tip of the holder 11, there is provided a through hole 14 that opens to the inner peripheral surface of the insertion hole 13. The through holes 14 are formed in a tapered shape in which the opening of the insertion hole 13 has a small diameter and are perpendicular to the central axis of the insertion hole 13 (holder 11) and are equally spaced by 90 degrees about the central axis. There are four radial lines. A chuck ball 15 is slidably arranged in each through hole 14.

The chuck balls 15 are formed in different diameters so that the diameters of the chuck balls 15 increase sequentially from the opening side of the insertion hole 13. The outer diameter of the chuck ball 15 located in the opening is formed to be slightly larger than the inner diameter of the opening, thereby preventing the chuck ball 15 from falling into the insertion hole 13.

An outer cylinder cover 16 is provided on the outer peripheral portion of the holder 11.
Is slidably fitted in the longitudinal direction of the holder 11.
Further, a taper 16b is formed on the inner peripheral surface 6a at the tip of the outer cylinder cover 16a, as in the first embodiment. On the other hand, on the rear end side of the outer cylinder cover 16, a compression spring 17 is wound around the holder 11. The compression spring 17 is attached to the holder 11
A ring 18 attached and fixed to the rear end of the outer cylinder cover 16 is always biased toward the outer cylinder cover 16 so that the outer cylinder cover 16 is constantly pressed toward the tip of the holder 11. In addition, the outer cylinder cover 16 includes the stepped portion 11 of the holder 11.
It is prevented from coming off from the holder 11 by engaging with a.

In this embodiment, the outer cylinder cover 16 is pulled against the elastic force of the compression spring 17 and moved toward the rear end of the holder 11 to position the chuck ball 15 at the taper 16b. To open the chuck balls 15. Then, the chucked member 2 is inserted into the insertion hole 13 of the holder 11, and the pulling of the outer cylinder cover 16 is released. As a result, the outer cylinder cover 16 moves toward the tip of the holder 11 by the compression spring 17, and the taper 16b of the outer cylinder cover 16 moves the chuck ball 15 toward the chucked member 2. As a result, the chuck balls 15 are
The chucked member 2 is chucked by sliding in the through hole 14 and pressing the outer peripheral surface of the chucked member 2.

According to this embodiment, since the compression spring 17 is used as the operating means of the outer cylinder cover 16, the chucking method is simplified. Also, the chuck balls 15 in the through holes 14
By using the taper as the holding means, the deterioration of the chucking accuracy due to mechanical fatigue can be reduced as compared with the holding by the claw as in the first embodiment. Further, even if the outer diameter of the member to be chucked 2 is changed, it can be dealt with to some extent by exchanging the chuck balls.

[0017]

As described above, according to the ball type chuck device of the present invention, the chucked member is inserted into the insertion hole at the tip of the holder, and the outer cylinder cover is moved toward the tip of the holder. Due to the taper formed at the tip of the inner peripheral surface of the chuck, the chuck ball moves in the through hole in the direction of the central axis of the holder, and the outer peripheral surface of the chucked member is pressed at equal intervals and chucked. As a result, the center axes of the holder and the member to be chucked can be easily matched, and, for example, the processing accuracy of a machine tool or the like can be improved.

[Brief description of drawings]

FIG. 1 is a central longitudinal sectional view showing a first embodiment of a ball type chuck device of the present invention.

FIG. 2 is a sectional view taken along line AA in FIG.

FIG. 3 is an enlarged sectional view of a B part in FIG.

FIG. 4 is an explanatory diagram showing a relationship between a distance between claws, a chuck ball diameter, and a chuck outer diameter.

FIG. 5 is a central longitudinal sectional view showing a second embodiment of the ball chuck device of the present invention.

6 is a cross-sectional view taken along the line CC in FIG.

FIG. 7 is an enlarged cross-sectional view of a D part in FIG.

FIG. 8 is a cross-sectional view of a conventional ball chuck device.

[Explanation of symbols]

 1,11 Holder 2 Chucked member 3,13 Insertion hole 4,14 Through hole 5,15 Chuck ball 6,16 Outer cylinder cover 6a, 16a Inner peripheral surface of insertion hole 6c, 16b Taper

Claims (1)

[Claims] 1. A holder in which an insertion hole for a chucked member is formed is provided inside a tip, and at least three through holes opened on the inner peripheral surface of the insertion hole are formed at equal intervals, and each through hole is formed in each through hole. At least one chuck ball is slidably arranged, an outer cylinder cover is slidably fitted on the holder, and the chuck ball is attached to the inner peripheral surface of the outer cylinder cover at the center of the insertion hole. A ball type chuck device characterized in that a taper that slides in a direction is formed.