JPH0871819A - Power chuck serving for both inner and outer diameter - Google Patents

Abstract

PURPOSE: To provide a power chuck which can grip the inside or outside of a workpiece without changing clamping jaws. CONSTITUTION: Plural oscillating members 17 with the tips having inner clamping jaws 23 for gripping the inner periphery of a workpiece are provided on the front inner side of a chuck body 1 fixed to the main spindle of a lathe, and plural oscillating members 37 with the tips having outer clamping jaws 43 for gripping the outer periphery of the workpiece are provided on the front outer side of the chuck body 1. The chuck body 1 is internally provided with inner-outer clamping jaw drive mechanism 11, 31 for oscillating the respective oscillating members 17, 37 simultaneously by the advance-retreat of a draw bar 3 so as to open-close the respective clamping jaws 23, 43.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power chuck for a lathe capable of freely grasping the inside or outside of a work without replacing a clamp claw.

[0002]

2. Description of the Related Art In a lathe chuck, a hand-tightened or power-driven scroll chuck can grasp the inside or outside of a work by using one type of clamp claw. However, most power chucks of the type in which the clamp jaws are opened and closed by utilizing the forward / backward movement of the drawbar are chucks dedicated to the inner diameter and the outer diameter.

[0003]

Particularly in the case of a power chuck of the type in which the swing member having the clamp claw at the tip is swung by the forward / backward movement of the draw bar, for example, when the draw bar is retracted, the swing member is slightly retracted. If the clamp claw at the tip clamps the inner circumference of the work and presses the work against the work stopper on the front surface of the chuck body, replace the clamp claw at the tip of the same swinging member for grasping the outer circumference. When trying to grasp the outer circumference of the work piece, the work piece is clamped when the draw bar is moved forward.

When the draw bar is retracted, that is, clamped when pulled, the swing member retracts and clamps by the amount of the play of the support portion as described above, so that the work can be pressed against the work stopper and held accurately. However, if the work is clamped by advancing the draw bar, there is a problem that the work floats from the work stopper.

An object of the present invention is to solve the above problems of the conventional power chuck and to provide a power chuck capable of grasping the inner diameter or the outer diameter of a workpiece under the same conditions without replacing the clamp claws. is there.

[0006]

In order to solve the above-mentioned problems, the present invention has a plurality of inner clamp claws for grasping the inner circumference of a work at the tip near the inside of the front part of the chuck body fixed to the spindle of a lathe. An oscillating member is provided, and a plurality of oscillating members having outer clamp claws for grasping the outer circumference of the work are provided near the front of the chuck main body. A structure is provided in which an internal and external clamp pawl drive mechanism is provided to open and close each clamp pawl by rocking the moving member at all.

[0007]

[Function] When grasping the inner diameter of the work, when the inner peripheral surface of the work is positioned outside the inner clamp claws on the inner side and the draw bar is retracted, the swing members interlocked with the draw bar are moved outward. When rotated, each inner clamp claw at its tip is pressed against the inner peripheral surface of the work to fix the work concentrically with the chuck body.

When the outer diameter of the work is to be grasped, the outer peripheral surface of the work is positioned inside the outer clamp claws on the outer side, and when the draw bar is retracted, the swing members interlocking with the draw bar are moved inward. The workpiece is pivoted in the direction, and the outer clamp claws at the tip end are pressed against the outer peripheral surface of the work to fix the work concentrically with the chuck body.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In the embodiment shown in the drawings, 1 is a chuck body which is concentrically fixed to the tip of a main shaft of a lathe (not shown) and is integrally fixed together with a rear member 2 by a plurality of bolts.

Reference numeral 3 denotes a drawbar which is moved forward and backward by a hydraulic cylinder (not shown) or the like. The rear end of the tubular small-diameter portion 5 at the rear portion of the clamp claw driving member 4 is fixed to the front end of the drawbar by a bolt 6, and the front portion of the member 4 is The protruding shaft 7 is a guide hole 8 on the front wall of the main body 1.
The hole 8 is closed by a dustproof lid 9.

The driving member 4 is fitted in the space 10 in the main body 1, and the small diameter portion 5 thereafter penetrates the central hole of the rear member 2 and is connected to the draw bar 3 as described above. . 11 of FIGS. 1 and 3 is a drive mechanism for the inner clamp claw,
A plurality of excitable sliding balls 13 rotatably mounted on the small diameter portion 12 of the drive member 4 and a round bar portion 14 at the rear part slidably fitted in the holes of each ball 13;
A plurality of rocking members 1 mounted on a spherical inner surface of a bearing race 16 having a spherical portion 15 fixed to the front wall of the main body 1 so as to be swingable.
It is composed of 7.

Then, the pressing element 19 is slidably mounted in the concave hole formed at the rear end of each of the round bar portions 14.
By pressing 9 against the rear member 2 by the spring 20,
The reaction force pushes the swinging member 17 forward.

The bearing race 16 is composed of a pair of upper and lower semi-circles, is fixed to the front portion of the main body 1 with a plurality of bolts, and extends laterally through the center of the spherical portion 15 of the member 17. The two ends of are engaged with the engaging portions on both sides of the bearing race 16 with a slight amount of play, so that the swinging member 17 performs an equalizing action.

Further, inner clamp claws 23 are fixed to the mounting portions 22 at the tip of the swinging member 17. A groove 24 having a T-shaped cross section with an enlarged inside is provided in the mounting portion 22 in the outer peripheral direction from the center side of the chuck body 1, and a T nut 25 is fitted into the groove 24 and loosely inserted in the hole of the clamp claw 23. The plurality of bolts 26 are screwed into the nut 25 so that the member 17
And the mounting portion 22 are integrally connected to each other so that the position can be adjusted. 27
Is a cemented carbide insert fixed to the clamp claw 23 with a screw 29.

Reference numerals 31 and 32 in FIGS. 1 and 4 denote a plurality of excitable sliding balls 33 rotatably mounted on the large-diameter portion 32 of the driving member 4 by the driving mechanism of the outer clamp claws, and the holes of the balls 33. The rear round bar portion 34 is slidably fitted, and the plurality of swing members 37 are swingably mounted on the spherical inner surface of the bearing race 36 having the spherical portion 35 fixed to the front wall of the main body 1. There is.

Then, the presser 39 is slidably placed outside the recessed hole formed at the rear end of each of the round bar portions 34, and the presser 3
By pressing 9 against the rear member 2 by the spring 40,
The reaction force pushes the swinging member 37 forward.

The bearing race 36 is composed of a pair of upper and lower semi-circles, is fixed to the front wall of the main body 1 by a plurality of bolts, and extends laterally through the center of the spherical portion 35 of the member 37. The two ends of are engaged with the engaging portions on both sides of the bearing race 36 with a slight amount of play, so that the swinging member 37 performs the equalizing action.

The outer clamp claws 43 are fixed to the mounting portions 42 at the tip of the swinging member 37. A groove 44 having an enlarged T-shaped cross section is provided in the mounting portion 42 from the center side of the chuck body 1 to the outer peripheral direction, and a T nut 45 is fitted into the groove 44 and loosely inserted in the hole of the mounting portion 42. A plurality of bolts 46 are screwed into the nut 45 so that the member 37 and the clamp claw 43 are integrally and positionally adjusted. FIG.
47 is an attachment fixed to the clamp claw 43,
It is manufactured according to the work and is detachably attached to the clamp claw 43 with a plurality of bolts 49.

Next, the chucking action of the embodiment will be described for the case where the works 50 and 51 having the shapes shown in FIGS. 3 and 4 are mounted. First, the case where the inner diameter of the work 50 is grasped will be described.

This chuck is of a retractable type, and when the retracting mechanism is unclamped, the front portions of the spherical portions 15, 35 of the swinging members 17, 37 are brought to the front side of the spherical inner surfaces of the bearing races 16, 36 by the springs 20, 40. It has been pressed.

Therefore, due to the play between the spherical inner surfaces of the races 16 and 36 and the spherical portions 15 and 35, the clamp claws 23 and 4 are formed.
No. 3 is pushed forward by about 0.5 mm compared to when clamped.

Next, the inner peripheral surface 5 of the ring-shaped work 50
2 is brought into contact with the inner side of each inner clamp claw 23 group at the uncuck position, and its end face is applied to the front end face of each work stopper (not shown), and the draw bar 3 is moved to the position shown in FIG.
Towards the left, pull to the left to start the clamp operation.

When the drawbar 3 is pulled as described above, the drive member 4 connected to the drawbar 3 is also retracted, and accordingly, each of the excitable sliding balls 13 is retracted while rotating the swinging member 17 about the spherical portion 15 thereof. To do.

By the above movement, each clamp claw 23 moves around the spherical portion 15 in an arc from the inner peripheral side to the outer peripheral side of the chuck body 1, and the cemented carbide insert 27 of each clamp claw 23 is moved to the workpiece 50. The inner peripheral surface 52 is pressed and grasped as shown in FIG.

Further, as described above, each clamp claw 23 which has advanced by about 0.5 mm at the time of uncucking moves backward by about 0.5 mm as the draw bar 3, the driving member 4 and the sliding ball 13 move backward at the time of chucking. For this reason,
After each clamp claw 23 grasps the workpiece 50 as described above, the amount of pull-in until the spherical portion 15 of the swing member 17 hits the rear portion of the spherical inner surface of the bearing race 16 by the pulling force of the draw bar 3 larger than each spring 20. Is obtained. Therefore, the end surface of the work 50 is in close contact with the end surface of each work stopper and is accurately grasped by each clamp claw 23.

After machining the outer diameter and the like in the chucked state, the draw bar 3 may be moved forward in order to bring it into the unclamped state. As a result, each part acts in the reverse of the chucking state, and each clamp claw 23 is moved. Work piece 50 by slightly moving forward
After the end face of is lifted from the end face of each work stopper, move outward and release the chuck.

Next, a case of grasping the outer circumference of the work 51 will be described. In the unclamped state in which the drawbar 3 is moving forward, the attachment 47 of each clamp claw 43 group at the unclamped position is formed in the groove on the outer periphery of the work 51.
Of the work stopper (not shown), and the draw bar 3 is pulled leftward in FIG. 1 to start a clamping operation.

When the drawbar 3 is pulled as described above, the drive member 4 connected to the drawbar 3 also retracts.

When the drive member 4 is retracted as described above, the exciting sliding ball 33 causes the swing member 37 to move.
It retreats while rotating around the spherical portion 35.
Due to the above movement, each outer clamp claw 43 has a spherical portion 35.
With the center of the chuck body 1, the chuck body 1 moves in an arc from the outer peripheral side to the centerline side, and the protrusions 54 of the attachments 47 of the respective clamp claws 43 are moved to the groove 5 on the outer peripheral side of the workpiece 51 as shown in FIG.
Figure out three.

Further, the clamp claw 43, which was moved forward by about 0.5 mm at the time of uncucking, is the draw bar 3 at the time of chucking.
Then, as the driving member 4 and the sliding ball 33 move backward, they move backward by about 0.5 mm. Therefore, after each clamp claw 43 grasps the work 51 as described above, each spring 40
The larger pulling force of the drawbar 3 provides the amount of retraction until the spherical portion 35 of the member 37 hits the rear portion of the spherical inner surface of the bearing race 36. Therefore, the end surface of the work piece 51 is in close contact with the end surface of each work piece stopper and each clamp claw 4
Accurately grasped by 3.

After the inner diameter is machined in the chucked state, the draw bar 3 may be moved forward to make it unclamped, whereby each part acts in the reverse of the chucking and each clamp claw 43 is slightly moved. After advancing so that the end surface of the work is lifted from the end surface of each work stopper, move outward and release the chuck.

During each of the above clamping operations, the workpiece 50,
Since the inner and outer peripheries of 51 are in a rough finished state before finishing, they are not perfect circles, but the clamp claws 23, 43 have spherical portions 15, 35.
The work of the work 50, 5 due to the action of the equalizing mechanism of the part
Be sure to grasp the inner and outer circumferences of 1.

In the above embodiment, the inner clamp claw 23 is made of the carbide insert 27, and the outer clamp claw 43 is made of the attachment 4.
7 is fixed, but if the shapes of the works 50 and 51 are different, attach an attachment to the clamp claw 23,
Of course, a carbide insert may be attached to the clamp claw 43.

[0034]

[Effect] According to the present invention, since the inner clamp claw and the outer clamp claw are clamped by the pulling action of one drawbar, the inner or outer diameter of the work can be grasped without replacing the clamp claw. Since the drawbar is pulled and clamped regardless of the diameter, the work is clamped while being pulled toward the chuck body, which has the effect of stabilizing the work during clamping.

[Brief description of drawings]

FIG. 1 is a vertical sectional side view of an embodiment.

FIG. 2 is a front view of the above.

FIG. 3 is an enlarged vertical side view of an inner clamp claw mounting portion.

FIG. 4 is an enlarged vertical sectional side view of an outer clamp claw mounting portion.

[Explanation of symbols]

 1 Chuck Main Body 3 Drawbar 4 Clamp Claw Drive Member 11 Drive Mechanism 17 Swing Member 23 Inner Clamp Claw 31 Drive Mechanism 37 Swing Member 43 Outer Clamp Claw 50 Work 51 Work

Claims (1)

[Claims] 1. A plurality of swinging members having inner clamp pawls for grasping the inner circumference of a work are provided near the front inside of the chuck body fixed to the main shaft of a lathe, and at the front outside of the chuck body. A plurality of oscillating members having outer clamp claws for grasping the outer circumference of the work are provided. Inside the chuck body, each of the oscillating members is oscillated by the draw bar forward and backward to open and close each clamp claw. A power chuck with inner and outer diameters that is equipped with an inner and outer clamp claw drive mechanism.