JPS6342969Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present application relates to a mechanical work driver that is attached to the main shaft of a machine tool such as a lathe and grips and rotates the outer periphery of a centered work.

Conventional Technology Many work drivers of this type have been used in the past. Conventional work drivers are heavy and unsuitable for high-speed rotation, so in order to correct the drawbacks of the conventional work drivers, the present applicant first proposed Japanese Patent Application Laid-Open No. 102406/1983 ( (hereinafter referred to as the "prior application") and has achieved the intended purpose.

Problems to be solved by the invention However, since the above-mentioned prior application uses a spring to return the correction plate and hold the posture,
Due to the weight of the correction plate itself or the resistance when the correction plate slides, the rotating claw may not return completely when the grip is released, and the elastic force of the spring may cause the grip to be released. This has the disadvantage that the gripping force is canceled out by acting in the direction of the gripping force.

Means for Solving the Problems In view of the above-mentioned shortcomings of the device of the prior application, the present application does not use a spring to grasp the posture and return the correction plate, but directly hooks the correction plate with the main claw, and The present invention will be described in detail below with reference to the drawings showing the embodiments, which eliminates the drawbacks of the device of the prior application by forcibly returning the correction plate and holding the posture by the backward movement.

Embodiment 1 is a chuck body of a two-jaw automatic centripetal chuck A, and the chuck body 1 is fixed to a main shaft (not shown) with screws 2 and rotated by rotation of the main shaft. On the front side of the chuck body 1, two sliding grooves 3, 5 are provided in the radial direction symmetrically with respect to the rotation axis.
3, and parent claws 4, 54 are slidably fitted into the respective grooves. Each of the main pawls 4 and 54 consists of two cranks 5 (one not shown) pivotally supported on the chuck body 1, a draw sleeve 6 inserted into the chuck body 1, a connecting bolt 7 fixed to the sleeve, and the bolt. 7 and a rotary cylinder (both not shown) connected via a drawbar, the actuating mechanism is configured to slide in the radial direction by a conventionally well-known operating mechanism. Further, on the front side of the main claws 4, 54, pivot parts 9, 59 of the gripping claws 8, 58, which will be described in detail later, are protrudingly provided.
The center of the chuck 59 is located on a line perpendicular to the axis of rotation of the chuck body, and is equidistant from the axis.

Next, 10 is a center pin, and the center pin 1
0 indicates a pilot bushing 11 that fits into the draw sleeve 6 and is screwed to the chuck body 1, and a pin presser 1 that is screwed to the pilot bushing 11.
The tip of the center pin 10 protrudes from the hole 512 of the pin holder 12 to the front surface of the chuck body 1, and is adapted to support the center hole of the workpiece M. A flange 6 is provided around the entire circumference of the pin holder 12.
12 are provided.

Next, the correction plate 14 and the gripping claws 8, 58, which constitute the main parts of the present application, will be explained. The correction plate 14 is fitted into a guide groove 15 provided on the front surface of the chuck body 1 in the same direction as the sliding direction of the master claws 4, 54, and is slidably attached to the front surface of the chuck body 1. As shown in FIGS. 1 and 2, the correction plate 14 has master claws 4 and 54 in the open position (the fully open position of the gripping claws described later).
When this is reached, the pivot parts 9, 59 of the main claws 4, 54 abut on the outer end surfaces 17, 517, respectively,
In addition, a pair of correction grooves 16, 516 having a length that allows the entire sliding range of the main claws 4, 54, and the entire circumference of the pin holding plate 12, especially on the side corresponding to the main claws 4, 54, are provided. An insertion hole 18 surrounding the surface with a predetermined clearance 19 is bored, the pivot parts 9 and 59 are fitted into the correction grooves 16 and 56, and the pin holding plate 12 is fitted into the insertion hole 18. The play gap 19 is covered by a flange 612 provided on the pin holding plate 12 to prevent chips and the like from entering. Further, two correction pins 20, 520 are provided protrudingly on the correction plate 14 as described above, and their protruding positions are aligned with the longitudinal center line of the correction groove 16, 516, that is, the center line of the pivot parts 9, 59. On opposite sides to each other and at equal distances in the vertical direction from the rotational axis of the chuck body 1, in other words, from the axis of the center pin 10 in the state shown in FIG.
It is set to be equidistant from the longitudinal center line between 6 and 56 in the left and right direction.

Next, each of the gripping claws 8, 58 is arranged so that the gripping parts 21, 521 provided over a predetermined range from the tip thereof are on opposite sides, and the pivot parts 9, 59 protruding from the main claws 4, 54 are It is rotatably fitted into the correction plate 14 and rotates while slidingly contacting the correction plate 14. Also, grip part 2
As the shape of 1,521 reaches the tip,
It has an arcuate surface such that the distance (radius) from the pivot parts 9, 59 increases. Further, each of the gripping claws 8, 58 is provided with a connecting groove 22, 522 into which the two correction pins 20, 520 described above are fitted, and the correction plate 14 and the gripping claw 8, 58 are connected to the connecting groove 22, 522. They are loosely connected via correction pins 20 and 520. The connecting grooves 22, 522 are bored at the positions where the connecting grooves 22, 522 are formed, as shown in FIGS. 1 and 2.
slides to the uppermost limit, and when the pivot parts 9 and 59 abut against the outer end surfaces 17 and 517 of the correction grooves 16 and 516, and the correction plate 14 is located at the center position (at this time, the center pin gripping member 13 and the insertion hole 18 are approximately equally spaced around the entire circumference), both gripping claws 8 and 58 are bored at positions that grip the fully open state, and the respective correction grooves 22 and 522 The size of the gripping claws 8 and 58 is set to allow the entire rotation range of the gripping claws 8 and 58, which will be described in detail later.

As shown in FIG.
The operation will be described in the case where the chuck main body 1 is supported eccentrically upward with respect to the center of rotation as shown in FIG. First, when the draw sleeve 6 is pulled to the left in FIG. 2 by a rotating cylinder (not shown), both cranks 5
The cranks (one crank not shown) are respectively swung to slide the master claws 4 and 54 toward the center of rotation of the chuck body 1. When the main claws 4, 54 are slid toward the rotation center of the chuck body 1 in this way, the main claws 4, 54
The gripping claws 8, 58 fitted in the pivot parts 9, 59 of 54 have the correction grooves 16,
516 in the direction of the rotation center of the chuck body, but the movement of the connecting grooves 22 and 522 toward the rotation center of the chuck body 1 is prevented by the correction pins 20 and 520 on the correction plate 14. Therefore, both gripping claws 8 and 58 rotate counterclockwise to reach the fourth position.
As shown in FIG. B, the gripping portions 21, 521 are close to the center of rotation of the chuck body 1. As a result of the rotation of these gripping claws 8 and 58, the gripping portion 21 of the upper gripping claw 8 on the side where the workpiece M is eccentric, that is, the upper gripping claw 8 in FIGS. Although the gripping claws 8 come into contact with the outer circumferential surface of the workpiece M and are prevented from rotating thereafter, the master claws 4 and 54 are still forcibly slid toward the rotation center of the chuck body 1. Therefore, as the master pawls 4 and 54 slide thereafter, the gripping pawl 8 is corrected by the connecting groove 22 pushing the correction pin 20 due to the pressing action in the axial direction acting on the gripping pawl 8 from the pivot portion 9. While sliding the plate 14 downward in FIGS. 1 and 4, the plate 14 itself is shown in FIG.
As shown in , the gripping part 21 is rotated clockwise (claw release direction) while in contact with the outer circumferential surface of the workpiece M, whereby the gripping part 21 of the gripping claw 8 slightly holds the workpiece M together with the center pin 10. It is pressed against the outer peripheral surface of the workpiece M while being rotated counterclockwise.
On the other hand, the gripping claw 58 is rotated counterclockwise in FIG. The groove 522 portion is pushed by the correction pin 520 and further rotated counterclockwise in FIG.
The gripping portion 521 of No. 8 is brought into contact with the outer peripheral surface of the workpiece M. In this way, the gripping portion 521 of the lower gripping claw 58
After contacting the outer peripheral surface of the workpiece M, the gripping portions 21, 521 of both gripping claws 8, 58 are strongly pressed against the outer peripheral surface of the workpiece M by the subsequent sliding force of the main claw 54, and this workpiece Grip M securely. next,
In this state, the spindle (not shown) is rotated to rotate the mechanical work driver and the work M counterclockwise in FIGS. 1 and 4, and the work M is processed. When a rightward (clockwise) moment is applied to the workpiece M as shown in FIGS. 1 and 4 during processing of the workpiece M, both gripping claws 8 and 58 react by an angle corresponding to the biting into the workpiece M. rotated slightly clockwise,
As a result, the correction pins 20, 520 on the correction plate 14
The large force applied to the correction pins 20, 520 and the correction plate 14 is no longer applied.

Next, when releasing the grip on the workpiece M, the draw sleeve 6 is slid in the opposite direction to that described above, so that each master pawl 4, 54 moves in the opposite direction, that is, outwardly from the rotation axis. slide. As a result of this sliding, the gripping claws 8 and 58 gripping the workpiece M, as shown in FIG. 520 and the connecting grooves 22, 522, respectively, to rotate clockwise, and in the middle of the rotation, the pivot portion 9 of the master pawl 4 moves into the correction groove 16 bored in the correction plate 14, which has been pushed down as described above. When it hits the outer end surface 17 and continues to move while lifting the correction plate 14, the master claws 4 and 54 return to their original positions as shown in FIG. The gripping claws 8 and 18 are in contact with the outer end surface 517 of the groove 516, and the gripping claws 8 and 18 are fixedly gripped. As a result, this can be carried out smoothly without interfering with the center pin gripping member 13.

Effects As detailed above, the present application eliminates the use of the posture gripping spring, which is a drawback of the earlier application filed by the applicant, JP-A No. 56-102406, and the sliding of the correction plate is controlled by the main claw. In addition to the above-mentioned advantages of the earlier application, which improves the drawbacks of the prior art by controlling only by the sliding of the This is an extremely important device that corrects the problem that the gripping force is canceled out by the elastic force.

[Brief explanation of drawings]

The drawings show an embodiment of the present application, and FIG. 1 is a front view, FIG. 2 is a sectional view taken along the line of FIG. 1, FIG. 3 is a sectional view taken along the line of FIG. 1...chuck body, 4, 54...main claw, 8,
58...Gripping claw, 9, 59...Pivotal part, 14...
Correction plate, 16,516... Correction groove, 19... Play, 20,520... Correction pin, 22,522...
...Connection groove.

Claims (1)

[Scope of utility model registration request] On the front surface of each main pawl of the automatic centripetal chuck, a gripping portion is formed in a predetermined range from the tip on a pivot point provided on a line perpendicular to the rotational axis of the chuck body and at equal intervals from the axis. The gripping claws are rotatably mounted so that the gripping parts are on opposite sides,
Furthermore, a pair of correction grooves in which the respective pivot parts abut against the outer end surface when the gripping claw is fully opened, an insertion hole surrounding the peripheral surface of the gripping member of the center pin with a predetermined clearance, and a longitudinal length of the correction groove. A correction plate having a pair of correction pins provided on opposite sides of the center line of the direction and on the opposite side of the tip of the gripping claw,
Each of the pivot parts is attached to each of the correction grooves, and a center pin gripping member is slidably attached to the front surface of the chuck body so as to fit loosely in the insertion hole, and each of the correction pins is provided on each of the gripping claws. A mechanical work driver with a connecting groove that allows the full rotation range of the gripping claw.