JPH07204909A - Double side chuck - Google Patents

Abstract

PURPOSE:To improve operational moving ratio and machining accuracy by making it possible for a chuck, which is provided on a machine tool such as a lathe which holds a workpiece and rotate it by a motor, to hold both ends of the workpiece assuming the form of protruding beyond both sides of the chuck and to simultaneously machine both sides of the said workpiece. CONSTITUTION:A both end opened cylindric collet sleeve 14, which is formed so that it can elastically expand and contract by supporting a rotating disc 10 on the inside circumference of a ring shaped part of a casing 1 through a bearing 9 and providing slittings 15 from its end surface, is arranged in the rotating center of the rotating disc 10. A clamp disc 19, which contracts a collet tube by impacting the tapered outside circumferential surfaces 16a, 16b of the collet sleeve 14 and makes it hold a workpiece 50 inserted into the collet tube, is concentrically screwed on the rotating disc 10 and it is equipped with a motor capable of rotating the rotating disc 10 forwardly and reversely and a stop plate for keeping the clamp disc 19 from rotating together with the rotating disc 10.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a chuck provided on a machine tool such as a lathe for gripping a workpiece and rotating it by a motor. More specifically, the workpiece is gripped in such a manner that both ends of the workpiece protrude from both sides of the chuck. The present invention relates to a double-sided chuck capable of simultaneously processing both ends of the workpiece.

[0002]

2. Description of the Related Art Generally, a chuck of a lathe inserts one end of a workpiece such as a bar into the chuck, grips the workpiece, and rotates the workpiece to form a bit on a portion protruding from the workpiece. Since it is intended to perform machining such as cutting by hitting with the above, it is necessary to reset the workpiece to the chuck when machining both ends of the workpiece.

[0003]

For this reason, when machining both ends is required, the workpiece must be reset on the chuck each time, which requires labor and time, resulting in poor work efficiency. There was a problem.

Further, when the workpiece is set again as described above, the set state changes minutely with each set, which causes a problem that the machining accuracy deteriorates.

[0005]

SUMMARY OF THE INVENTION In order to solve the above problems, the present invention is to provide a double-sided chuck which can set both ends of a workpiece only once by setting the workpiece on the chuck.

For this reason, the double-sided chuck of the present invention is a double-sided open cylinder which is formed so as to elastically expand and contract by supporting the rotary disk through a bearing on the inner periphery of the annular portion of the casing and providing a slit from the end surface. -Shaped collet sleeve is arranged at the center of rotation of the rotary disk, and the tapered outer peripheral surface of the collet sleeve is pressed to shrink the collet tube and hold the workpiece inserted in the collet tube. A motor capable of concentrically screwing the tightening board to the rotary disk, rotating the rotary disk so as to rotate in the forward and reverse directions, and a braking device for preventing the tightening disk from rotating together with the rotary disk. It is characterized by comprising.

Further, the present invention is characterized in that, in the above-mentioned double-sided chuck, a flywheel is provided in place of the brake.

[0008]

[Function] By operating the brake to prevent rotation of the tightening plate with the rotating plate and rotating the rotating plate in the forward direction, the tightening plate is screwed to the rotating plate and the collet tube is contracted so that the workpiece is It can be held. Then, the braking of the tightening plate by the brake is released and the rotary plate is rotated in the forward direction so that the workpiece is rotated and both ends thereof can be machined such as cutting. When the brake is operated and the rotary disk is rotated in the reverse direction, the tightening disk is screwed in an opposite direction to the rotary disk, the collet tube is restored, and the workpiece is released from the grip.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to the drawings. 1 and 2 show a double-sided chuck according to the present invention in a longitudinal section and a right front view thereof. In the figure, reference numeral 1 denotes a casing fixed to an attachment portion 4 by inserting a bolt 3 into the attachment base portions 2 and 2, and an annular portion 5 is formed in the casing 1 and diagonally above the outer periphery of the annular portion 5. A tubular extension 6 is integrally provided on the base.

An outer race of the bearing 9 is fixed to the inner circumference of the annular portion 5 by bolts 7 and retaining rings 8 as shown in an enlarged view in FIG. Then, the rotary disk 10 is fitted into the inner race of the bearing 9, and an annular gear 11 is fixed to one surface of the rotary disk 10 with bolts 12 to sandwich the inner race, and the rotary disk 10 is fixed to the annular portion 5. It is rotatably supported inside. Reference numeral 12 is an annular cover further fixed to one surface of the gear 11 by a bolt 13.

As shown in FIG. 4, reference numeral 14 denotes a cylindrical collet sleeve whose both ends are open. The collet sleeve 14 is provided with slits 15 alternately from both end surfaces so that its diameter can be elastically expanded and contracted. Has been done. The outer peripheral surfaces 16a and 16b near both ends are formed in a tapered end surface shape.

The collet sleeve 14 is the turntable 10 described above.
It is arranged so that one outer peripheral surface 16a thereof abuts on the tapered opening 17 provided at the center of rotation.

Further, a screw groove 18 is formed on the inner circumference of the rotary disk 10, and a substantially cylindrical tightening disk 19 is screwed into the screw groove 18, and the collet sleeve 14 is loosely fitted in the tightening disk 19. At the same time, the collet sleeve 1 is inserted into a tapered opening 22 of an opening plate 21 fixed to one end of the tightening plate 19 with a bolt 20.
The other outer peripheral surface 16b of No. 4 is abutted.

A gear 23 having the same diameter as the gear 11 is rotatably attached to the rotary disc 10 on the side opposite to the gear 11 of the rotary disc 10. That is, the bolt 2 on the turntable 10
The retaining ring 25 is fixed by 4 and the annular sliding body 26 is rotatably held by the retaining ring 25, and the rotation transmitting ring 28 and the gear 23 are fixed to the annular sliding body 26 by the bolt 27. The rotation transmission ring 28 has a spline (axial groove) 29 formed on the inner peripheral portion thereof, and the spline 29 meshes with a spline formed on the outer periphery of the front end collar portion 30 of the tightening board 19 to rotate the gear 23. Can be transmitted to the tightening board 19. In addition, 31 is the bolt 3 for the rotation transmission ring 28.
It is an annular stopper fixed by 2 to limit the axial movement range of the tightening board 19. Reference numeral 33 is an annular cover fixed to the gear 23 with bolts 34.

The cylindrical extension 6 of the casing 1 has a bearing 3
A rotary shaft 36 is pivotally supported by 5, 35, and a gear 38 fixed to the rotary shaft 36 by a key 37 is meshed with the gear 11. Further, a rotary shaft 39 is rotatably supported by bearings 40, 40 so as to be concentric with the rotary shaft 36, and a gear 42 fixed to the rotary shaft 39 by a key 41.
Is meshed with the gear 23.

Then, a bolt 43 is attached to one surface of the tubular extension 6.
The case 44 is fixed by the above, and the housing of the motor 45 is fixed to the case 44 with the bolt 46, and the rotation shaft of the motor 45 is connected to the rotation shaft 36 via the joint 47. The motor 45 is a motor that can rotate in the normal and reverse directions.

A case 49 is provided on the other surface of the tubular extension 6.
An electromagnetic rotary brake 48 is provided therein, and the brake is applied to the rotation of the rotary shaft 39 by operating the brake 48.

FIG. 5 is a plan view showing an outline of a cutting machine such as a lathe equipped with the double-sided chuck, 50 is a round bar-shaped work held by the double-sided chuck, and 51a and 51b are tool bits 52, respectively. The turrets 53a and 53b which it has are drills.

In the double-sided chuck constructed as described above, the workpiece 50 is inserted into the collet sleeve 14, and the brake 4
By operating 8, the rotation of the rotary shaft 39, the gear 42, and the gear 23 is stopped, and the rotation transmission ring 28,
With the rotation of the tightening board 19 that is continuously hitting via the spline 29 being stopped, the motor 45 is normally rotated to transmit the rotation of the gear 38 to the turntable 10 via the gear 11. By doing so, the rotary plate 10 rotates relative to the tightening plate 19, so that the tightening plate 19 moves along the screw groove 18 in FIG.
Screw in the direction shown in. Therefore, the opening plate 21 integrated with the tightening plate 19 moves in the direction of the arrow, and the opening 22 presses the outer peripheral surface 16b. Therefore, the outer peripheral surfaces 16a and 16b of the collet sleeve 14 are pressed and the collet sleeve 1
4 contracts and the inner diameter becomes smaller, so that the outer periphery of the workpiece 50 can be clamped and gripped.

Thus, the workpiece 50 is the collet sleeve 1
Tightening board 1 by the brake 48 when it can be set in 4
When the braking of 9 is released, the tightening board 19 is rotated together with the rotating board 10 by the rotation of the motor 45, and the workpiece 50 can be rotated in the gripped state. For this reason, the tool rests 50a and 51b can be moved to cut the outer peripheries of both ends of the workpiece 50 at the same time by the cutting tool 52, and both end surfaces of the workpiece 50 can be simultaneously drilled by the drills 53a and 53b.

When the work piece 50 thus machined is removed from the collet sleeve 14, the motor 45 is stopped once, and the rotation of the work piece 50 is stopped, and then the brake 48 is operated to stop the tightening board 19 and the motor. Reverse 45. As a result, the rotary disk 10 rotates relative to the tightening disk 19 in the opposite direction to the above, and the tightening disk 19 is screwed along the screw groove 18 in the direction opposite to the arrow a in the figure, so that the opening The pressing of the outer peripheral surface 16b by the opening 22 of the board 21 is released, and the elasticity of the collet sleeve 14 restores the inner diameter of the collet sleeve 14 to enlarge the inner diameter of the workpiece 50.
Therefore, the workpiece 50 can be removed.

By operating the brake 48 in this manner, the tightening disc 19 is prevented from rotating together with the rotary disc 10 and the rotary disc 10 is normally or reversely rotated by the motor 45, whereby the collet sleeve 14 is rotated. Thus, the workpiece 50 can be easily gripped or released.

In this way, since the braking device 48 restrains the accompanying rotation of the tightening board 19, a flywheel is provided on the rotating shaft 39 instead of the braking device 48, and when the motor 45 is normally rotated. Alternatively, even when the tightening board 19 is temporarily prevented from rotating due to the inertia of the flywheel when it is rotated in the reverse direction, the collet sleeve 14 can hold or release the work piece 50 similarly to the brake machine 48.

[0024]

As described in the above embodiments, according to the double-sided chuck of the present invention, a workpiece is inserted into a cylindrical collet sleeve whose both ends are open and a slit is provided, and the collet sleeve serves as a rotary disk. Since the workpiece can be gripped by expanding and contracting by screwing due to relative rotation with the tightening board, both ends of the workpiece can be gripped and rotated while protruding from both end surfaces of the collet tube. For this reason, both ends of the workpiece can be machined by setting it once, and the time and labor required can be greatly reduced, which improves working efficiency and improves machining accuracy. Moreover, since the workpiece can be gripped with a small clamping margin, there is an advantage that both processable end portions can be lengthened.

[Brief description of drawings]

FIG. 1 is a partial vertical cross-sectional side view showing an embodiment of a double-sided chuck according to the present invention.

FIG. 2 is a right front view of FIG.

FIG. 3 is an enlarged view of a main part of FIG.

FIG. 4 is a perspective view of a collet sleeve.

FIG. 5 is a plan view showing the outline of a cutting machine including a double-sided chuck according to the present invention.

[Explanation of Codes] 1 Casing 5 Annular portion 9 Bearing 10 Rotating disk 11 Gear 14 Collet sleeve 15 Slot 16a, 16b Outer peripheral surface 18 Screw groove 19 Clamping board 23 Gear 26 Annular sliding body 28 Rotation transmission ring 29 Spline 36 Rotating shaft 38 Gears 39 Rotating Shafts 42 Gears 45 Motors 48 Brakes 50 Workpieces

Claims (2)

[Claims] 1. A cylindrical collet sleeve which is open at both ends and is formed so as to elastically expand and contract by supporting a rotary disk through a bearing on an inner circumference of an annular portion of a casing and providing a slit from an end surface. The tightening board is disposed at the center of rotation of the board, and presses the tapered outer peripheral surface of the collet sleeve to shrink the collet tube to hold a work piece inserted in the collet tube. And a motor that is concentrically screwed together and that is capable of rotating the turntable such that the turntable can rotate forward and backward, and a brake that stops the tightening disc from rotating with the turntable. Characteristic double-sided chuck. 2. The double-sided chuck according to claim 1, wherein a flywheel is provided instead of the brake.