JPH01171702A - Chuck for long size material - Google Patents

Abstract

PURPOSE:To vibration-isolatingly hold a long-size material rotating at a high speed by operating a chuck portion which strongly holds the long-size material in a position in close vicinity to a tool rest and a chuck portion which bufferingly hold the middle portion of the material a certain distance apart from that position, by means of a common cylinder. CONSTITUTION:As a pressure oil is poured from a port 17 into a left-side operation chamber d2, it also flows into a buffering chamber r1. At this time, a piston 13 is moved to the right while the collet 14 of a chuck portion 7 is moved to the left to clamp a long-size material. At the same time, since the movement of the piston 13 moves the collet 11 of a chuck portion 6 to the right, the collet 11 together with the collet 14 also clamps the outer peripheral face of the long- size material. As the pressure oil is fed into the buffering chamber r1 at the time of clamping by the collet 14, the collet 14 bufferingly holds the middle portion of the long-size material under the effects of both slopes 14a, 18a and the pressure oil in the buffering chamber r1. Then, at the time of releasing the long-size material, pressure oil is fed into a right-side operation chamber d1 via a port 16 and an oil passage P1 to move the collet 14, a linking cylinder 30, and the collet 11 to the left.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a chuck for holding elongated materials such as bars.

[Conventional technology]

Generally, in order to process and cut long materials such as bars, for example, a bar feeder is placed adjacent to the lathe, and the bar feeder feeds the bars one by one into the lathe, and at the same time feeds the bars one by one to the lathe's spindle. The tip of the bar is held by the chuck, and the tip of the bar is processed using a tool such as a tool on a tool post.

In recent years, with the development of machining technology, there is a desire for faster machining.
Therefore, it has been desired that the chuck for holding the bar material also has a holding force that prevents vibration.

[Problem that the invention seeks to solve]

However, in conventional lathes, when machining a long bar, the bar is rotated and held by a chuck installed at one location near the turret, but this holding is not sufficient and the bar rotates at high speed. The disadvantage was that the vibrations of the rods being held could not be sufficiently suppressed.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a chuck for elongated materials, which can hold elongated materials such as rods rotating at high speed in a state that sufficiently prevents vibrations.

[Means for solving problems]

SUMMARY OF THE INVENTION The present invention provides a long material chuck that is attached to the rotating main shaft of a machine tool and grips a long material to be processed, such as a bar, in which the chuck is provided at a position close to a tool rest. First for strongly gripping long materials
a chuck part; and a second chuck part provided at a position spaced apart from the first chuck part in a direction away from the tool rest by a predetermined distance and for gripping the middle part of the elongated material in a cushioning manner, The first and second chuck parts were operated by one common actuation cylinder.

[Effect]

A long material such as a bar that rotates at high speed is strongly gripped by a first chuck provided in a position close to the tool rest of the lathe, and the first chuck is tilted at a predetermined distance in the direction of leakage from the tool rest. The intermediate portion of the elongated material is provided at a spaced apart position and is gripped by the second chuck portion in a cushioning manner. Therefore, the long material rotating at high speed is gripped at two points, and its vibrations are sufficiently prevented. Furthermore, the first chuck part grips the elongated material securely in a non-cushioning manner, whereas the second chuck part grips the long material in a cushioning manner. In this way, by firmly gripping the rod with one chuck part and gripping it with a cushioning effect with the other chuck part, vibrations of the bar can be firmly suppressed without play between the two chuck parts.

〔Example〕

In FIG. 1, the chuck M of the present invention has a spindle 2 rotatably held on a spindle stock 1, and this spindle 2 is rotatably held on the head stock 1 by a bearing 3.4. A pulley 5 is provided at the left end of the spindle 2 in the drawing, and this pulley 5 is connected to a large number of belts b, b.
, . . . are rotationally driven by bo. A first chuck part 6 is provided on the right side of the spindle 2 in the drawing, and a second chuck part 7 is provided on the opposite side of the first chuck part 6 with respect to the headstock 1.

The first chuck section 6 has a casing 8, and the casing 8 is fixed to the right end of the spindle 2 in the figure with a bolt 9. Inside the casing 8,
An actuating sleeve 10 is provided, and the actuating sleeve 10 has an inner peripheral inclined surface 10a. On the other hand, a normal collet 11 is provided within the operating sleeve 10, and an outer peripheral inclined surface 11a that cooperates with the inclined surface 10a of the operating sleeve 10 is formed on the outer peripheral surface of the tip portion of the collet 11.

The second chuck section 7 has an operating cylinder 12, and the operating cylinder 12 includes a large diameter section 12a having a large diameter and a collet holding cylinder section 12b connected to the large diameter section 12a. A piston 13 is provided within the large diameter portion 12a, and a threaded portion 13a is provided at the left end of the piston 13 in the drawing.
is formed, and this threaded portion 13a engages with the right end portion in the figure of an expandable and retractable collet 14 that is provided within the collet holding cylinder portion 12b.

The collet holding cylinder portion 12b is rotatably held by a holder 15, and the holder 15 is formed with bows 16 and 17 for supplying pressure oil. An operating sleeve 18 is provided between the outer circumferential surface of the collet and the inner circumferential surface of the collet holding cylinder portion 12b, and an inclined surface 18a is formed on the inner circumferential surface of the front end of the operating sleeve 18. A stepped portion 18b is formed. The inclined surface 18a cooperates with the outer peripheral inclined surface 14a of the collet 14, and the inclined directions of these inclined surfaces 14a, 18a and the inclined surfaces 10a, lla of the first chuck portion are formed to be the same.

On the other hand, a step portion 12c is formed on the inner circumferential surface of the collet holding cylinder portion 12b opposite to the step portion 18b of the operating sleeve, and a g-space r1 is formed between these step portions 18b and 12c. This #1 chamber r1 has the operating cylinder 12
One end of an oil passage P2 formed within the inner wall thickness is connected thereto. This oil continuation path P is the working chamber d on the left side in the figure of the large diameter part.
Connected to 2. An oil passage P 1 is connected to the working chamber d 1 on the right side of the piston 13, and the tip of this oil passage P1 is connected to the boat 16. The oil from this boat 16 is drained through an annular extinguishing aperture formed on the inner circumferential surface of the holding body 15.
The oil in the boat 17 is designed to flow into the oil passage P1 through the oil passage P1, while the oil in the boat 17 is made to flow into the oil passage P2 through a vent a2 formed on the inner circumferential surface of the holder. This holding body 15 rotatably holds the collet holding cylinder portion 12b via bearings b, b, . . . b, and the annular groove a, In addition to annular grooves a 1 and a 2 , annular grooves a 1 and a 2 are provided, and oil flows into the drain casing 20 through the annular grooves a 1 and a 2 and is discharged to the outside through a drain pipe 21 connected to the drain casing 20 .

Next, the operation of the present invention will be explained.

A long material to be processed passes through the collet 14, spindle 2, and collet 11 from the left side in the figure, and its tip reaches the tool rest. FIG. 1 shows collets 14 and 11 releasing elongated material.

Next, pressure oil is injected from the boat 17 into the left working chamber d2 via the oil passage P2 and flows into the buffer chamber r1. At this time, the piston 13 moves to the right in the drawing, and thereby the collet 14 of the second chuck section 7 moves to the left to clamp the long material. At the same time, the movement of the piston 13 is controlled by the collet 1 of the first chuck part 6 via a connecting cylinder 30 that is slidably provided in the spindle 2.
1 to the right side of the diagram. As a result, the collet 11 of the first chuck section 6 and the collet 14 of the second chuck section 7 tighten the outer peripheral surface of the elongated material.

The collet 11 of the first chuck section 6 firmly holds the tip of the elongated material in a non-MI manner, while the collet 14 of the second chuck section 7 grips the middle part of the elongated material in an [i-like manner]. . That is, when tightening the collet 14, pressure oil is also supplied to the buffer chamber rl, so that the collet 14 is tightened on both the inclined surfaces 14a and 1.
8a and the pressure oil in the buffer chamber r1, the intermediate portion of the elongated material is gripped in a cushioning manner.

When releasing the elongated material, pressure oil is supplied to the right working chamber d1 via the boat 16 and the oil passage P1, and the collet 14, the connecting cylinder 30, and the collet 11 are moved to the left in the figure.

In this way, the first chuck part 6 firmly holds the elongated material, and the second chuck part 7 is provided at a constant distance from the long material.
If the long material is gripped in a GTR manner, vibrations can be sufficiently prevented even when the long material is rotated at high speed, and one of the chuck parts 6 and 7 will not come loose. Furthermore, in this embodiment, both chuck parts are operated by a common operating cylinder 12, so that the entire apparatus can be made compact.

Furthermore, since both chuck parts 6, 7 are caused to perform the same operation by the movement of the piston 13 in the same direction, the structure is extremely simple.

In FIG. 1, pressure oil is supplied to the buffer chamber r1, but as shown in FIG. 2, a coil spring S for buffering may be housed in the chamber r2. Note 5. In this case, an oil passage P3 is provided in place of the oil passage P, and this oil passage P3 is not connected to the buffer chamber S, and as shown in FIG. r1. The collet 14 without providing r2
is directly inserted into the collet holding cylinder 12b, and the tip inner inclined surface of the holding fm12b cooperates with the tip outer circumferential inclined surface of the collet 14. The lead groove 30 etc. may be provided directly. In this case, the body of the chuck must be made of a relatively soft metal, and the lead eraser 30 functions to allow the body of the collet 14 to expand and contract as the piston 13 moves.

〔Effect of the invention〕

Since the present invention is configured as described above, it is possible to grip a rotating long material in a state where vibrations can be sufficiently prevented, and the entire device can be made compact.

[Brief explanation of the drawing]

FIG. 1 is a partial vertical cross-sectional view of a chuck for elongated material of the present invention;
FIGS. 2 and 3 are longitudinal sectional views showing other embodiments of the second chuck section. DESCRIPTION OF SYMBOLS 1... Spindle head, 2... Spindle, 6... First chuck part, 7... Second chuck part, 11.14...
collet, 15...holding body, 18...operating cylinder, rl...m town room. Applicant's representative Yasushi Ishikawa Rikitsutsu 2 Figure

Claims (1)

[Claims] 1. A long material chuck that is attached to a rotating main shaft of a machine tool to grip a long material to be processed, such as a bar, wherein the chuck is located close to a tool rest. A first chuck part is provided to strongly grip the elongated material, and a first chuck part is provided at a position spaced apart from the first chuck part by a predetermined distance in a direction away from the tool post to cushion the middle part of the elongated material. a second chuck portion for gripping;
A chuck for elongated material, wherein the first and second chuck parts are operated by one common actuation cylinder. 2. The first and second chuck portions perform the same operation by the movement of the operating cylinder in the same direction to grip and release the elongated material at the same time. Chuck for the long materials listed. 3. The working cylinder is driven by hydraulic pressure, and the second chuck part includes a casing and an expandable collet that is provided in the casing and grips a long material and is moved in the axial direction by the working cylinder. and an actuating sleeve that accommodates the collet and has an inner circumferential inclined surface that cooperates with the outer circumferential inclined surface thereof and is slidable in the axial direction of the second chuck part, the actuating sleeve and the inner wall of the casing. A buffer chamber for receiving pressure oil is formed therebetween, and the actuating sleeve moves in a direction to increase the pressure in the buffer chamber when the collet grips a long material. A chuck for a long material according to item 1 or 2. 4. The second chuck part includes a casing, a collet that is provided in the casing and is expandable and retractable that grips a long material and is moved in the axial direction by an operating cylinder, and a collet that accommodates the collet and has an outer circumferential slope. an operating sleeve having an inner circumferential inclined surface that cooperates with the surface and slidable in the axial direction of the second chuck part, and the collet is operated in a cushioning manner between the operating sleeve and the inner wall of the casing. A chuck for elongated material according to claim 2, characterized in that a buffer spring is interposed. 5. The second chuck section has a casing and an expandable and contractible collet that is provided in the casing and grips the elongated material and is moved in the axial direction by an actuating cylinder. A chuck for elongated material according to claim 2, characterized in that it is made of a relatively soft material and its body is slightly expandable and retractable in the axial direction.