JPH10296512A - Chuck - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform chucking and unchucking operation for a chuck to gather with centering without using an actuator. SOLUTION: A center 20 which can slide in the center direction is provided in the center of a chuck body 15 with jaws 17. A center ring 26 of a cam shape is provided between the center 20 and each jaw 17. In a process in which a workpiece W engaged in a center hole C is pressed in a chuck body side 15, the jaw 17 is rotated and displaced by the center ring 26 to chuck the workpiece W.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a chuck used for chucking operations of various types of machining, and more particularly, when a slidable center provided at the center of the chuck is used together, the sliding displacement of the center is improved. The present invention relates to a chuck capable of performing a chucking operation of a jaw by utilizing a chuck.

[0002]

2. Description of the Related Art As is well known, a so-called power chuck having a hydraulic cylinder or the like as an actuator is used for a chucking operation in a machining process of a work for mass production (for example, Japanese Utility Model Application Laid-Open No. 58-177207). Reference).

[0003]

The conventional power chuck has an advantage that the chucking operation and the unchucking operation can be performed quickly, but on the other hand, in order to convert the movement of the actuator itself to the movement of the jaw. A plurality of power transmission members must be interposed between the two, which results in an increase in the size of the chuck itself due to an increase in the number of parts and an increase in equipment costs, which is not preferable.

The present invention has been made in view of the above problems. When a slide center provided at the center of a chuck is used together, the jaw of the jaw is effectively used by utilizing the slide displacement of the center. An object of the present invention is to provide a chuck capable of performing substantially the same function as a power chuck without attaching an actuator by performing a chucking operation.

[0005]

According to the first aspect of the present invention, there are provided a plurality of jaws provided on a chuck main body, and a center provided at a central portion of the chuck main body so as to be slidable in the axial direction thereof. By supporting the other end of the work, one end of which is supported by another support means, at the center and pushing the work into the chuck body together with the center, the jaw performs a chucking operation according to the slide displacement of the center. It is characterized in that it grips a work.

According to a second aspect of the present invention, a drive cam is provided between the jaw and the center according to the first aspect of the present invention, the drive cam being in contact with the inclined cam surface on the jaw side, so that the end of the center slide stroke. The jaws are driven by a drive cam to perform a chucking operation.

According to a third aspect of the present invention, the center and the drive cam are configured so as to be relatively movable in the axial direction of the center in the second aspect of the invention, and the center is located at the end of the slide stroke of the center. It is characterized in that the center drives the jaws via a drive cam.

According to a fourth aspect of the present invention, the drive cam according to the third aspect of the invention is configured to be floatable with respect to the center, and the drive cam equalizes the chucking forces of the plurality of jaws. It is characterized by having an equalizing function.

Therefore, according to the first aspect of the present invention,
The other end of the work, one end of which is supported by another supporting means such as a chuck or a center, is supported by the center in the chuck body, and the work is pushed into the chuck body side, so that the jaw according to the sliding displacement of the center. Autonomously performs a chucking operation to grip the other end of the work.

According to the second aspect of the invention, the jaw does not perform a chucking operation at the initial stage of the center slide stroke, and is driven by the jaw or the drive cam at the end of the slide stroke to chuck the workpiece. Will do.

According to the third aspect of the present invention, since the center and the drive cam can move relative to each other, the jaw chucks at an optimal timing with respect to the slide stroke of the center.

According to the fourth aspect of the present invention, since the drive cam has a floating structure, the chucking force of each jaw is equalized, and, for example, even when there is a processing error in the diameter of the work. Thus, it is possible to reliably chuck the work.

[0013]

According to the first aspect of the present invention, when the workpiece is chucked by the chuck having the center at the center, the jaws are operated to chuck according to the sliding displacement of the center. Because the center operation and the chucking operation are performed completely mechanically in synchronization with each other, the operation reliability is high, and the chucking operation of the jaw is performed while having substantially the same function as the power chuck. There is no need for an actuator for performing the operation, and there is an effect that a small chuck having a small number of parts can be provided at low cost.

According to the second aspect of the present invention, the jaw is driven by the drive cam to perform the chucking operation only at the end of the center slide stroke, and as a result, the work is stored in the chuck body. The chucking operation of the jaws in a state in which is fully pressed, in addition to the same effect as the invention according to claim 1,
There is an effect that the contact area between the jaw and the work and thus the gripping area can be secured sufficiently large to improve gripping reliability.

In particular, according to the third aspect of the invention, the center and the drive cam are configured to be relatively movable, and not all of the center's sliding stroke is converted to the chucking operation of the jaw. Therefore, the jaws can be chucked at an optimal timing with respect to the center slide stroke. In addition to the same effect as the invention described in claim 2, the work is pushed further deeper into the chuck body. Thus, there is an effect that the workpiece can be chucked more reliably.

According to the fourth aspect of the present invention, the drive cam has a floating degree of freedom in addition to the slidable degree of freedom, and exhibits a so-called equalizer function. Even if the chucking force of each jaw is equalized, there is an effect that even a work having a dimensional variation can be reliably chucked.

[0017]

1 to 3 show a typical embodiment of the present invention. When a quenching process is performed on a journal portion J of a crankshaft W of an internal combustion engine, the crankshaft W is removed. 2 shows an example of a chuck for supporting both ends.

As shown in FIG. 3, a headstock 1 and a tailstock 2 are arranged opposite to each other in the quenching equipment, and the tailstock 2 is fixed in position while the headstock 1 is attached to the tailstock 2. It is possible to move forward and backward. As will be described later, the head stock 1 and the tail stock 2 support a crankshaft (hereinafter, referred to as a work) W at both ends, and the spindle 3 is driven to rotate. W is driven to rotate.

A conventionally well-known power chuck 4 is mounted on the tip of the spindle 3 of the head stock 1. When the work W is conveyed to a predetermined position by conveying means (not shown), the head stock 1 moves forward by a predetermined stroke. Thus, the chuck claw 5 of the power chuck 4 grips one end Wa of the work W.

On the other hand, a sleeve 7 serving also as a piston is inserted and supported in the housing 6 of the tail stock 2 so as to be able to advance and retreat. The housing 6 and the sleeve 7 form a hydraulic or pneumatic type air cylinder 8. ing.
A spindle 10 is rotatably supported on the sleeve 7 via a bearing 9.
A chuck 11 to be described later is mounted at the leading end of the “0”.

Therefore, the sleeve 7 moves forward by the operation of the cylinder 8 with respect to the work W previously held by the power chuck 4 on the headstock 1 side, so that the chuck 11 at the tip of the spindle 10 on the tailstock 2 side is moved. The other end Wb of the work W is gripped, and as a result, the work W is supported by the chucks 4 and 11 at both ends. In this state, the quenching process is performed on the journal portion J of the work W. The work W is rotationally driven at a low speed so that uneven quenching does not occur. In order to stop the work W later at the so-called fixed angle stop position, the spindle 1
The rotation of the work W is detected by the rotation sensor 13 with the disk 12 rotating integrally with the workpiece 0 as a close body.

FIGS. 1 and 2 show details of the chuck 11 on the tail stock 2 side. A substantially cylindrical chuck body 15 is provided as a chuck body in a hollow shank portion 14 which is press-fitted and fixed to a spindle 10. Are fixed integrally with bolts 27, and the chuck body 15 has a shape that is slit left and right at a central portion, and a jaw that also serves as a pair of chuck claws is provided in a slit 16 at the central portion. 17 is rotatably mounted via a pin 18. A return spring (compression coil spring) 19 is provided between each jaw 17 and the chuck body 15.
The jaws 17 are respectively urged in the unchucking direction.

A center 20 slidable in the axial direction is inserted and supported in the center of the chuck body 15 and the shank 14. The center 20 is formed by a shaft portion 21 and a center body 22 attached to the tip of the shaft portion 21. A return spring (compression coil spring) 24 is interposed between the shaft portion 21 and an end cap 23 at the rear end of the shank portion 14. While being constantly biased in the forward direction,
The shank portion 14 is formed by the engagement between the key 25 and the key groove 26.
At the same time, the stroke is restricted.

A center ring 26 having a tapered cone shape is inserted and supported as a drive cam in the shaft portion 21 of the center 20. A predetermined play G is provided between the center ring 26 and the shaft 21 so that the center ring 26 is slidable with respect to the shaft 21 and, at the same time, tilts or moves in the range of the play G. It has a so-called floating structure that can be moved in the radial direction.

Each jaw 17 has a center ring 2
The inclined cam surfaces 17a corresponding to the 6-side inclined surfaces 26a are formed respectively, and the respective jaws 17 are rotationally driven, that is, chucked, by the sliding contact between the inclined surfaces 26a and the inclined cam surfaces 17a on the center ring 26 side. It is designed to be driven by unchucking. The regulating surface 26b of the center ring 26 on the side opposite to the inclined surface 26a is formed in the groove 17 of the jaw 17 adjacent to the inclined cam surface 17a.
b.

Therefore, according to the structure of the chuck 11, in the free state, as shown in FIG. And the center ring 26 is engaged with the groove 17b on each jaw 17 side at the same time. As a result, only the force of the return spring 19 acts on each jaw 17, and each jaw 1
7 self-holds the unchucking state shown in FIG.

On the other hand, as shown in FIGS. 1A and 1B and FIG.
Is moved forward together with the spindle 10 together with the sleeve 7 with respect to the work W, the center 20 is engaged with the center hole C on the work W side. When the chuck 11 is further advanced, the center 20 is relatively pushed into the chuck body 15 along with the work W, and the lower surface 22a of the neck of the center 20 is restricted by the regulating surface of the center ring 26 as shown in FIG. 26b, contact with the center 20 for the first time from this point
Is transmitted to the center ring 26, the inclined surface 26a of the center ring 26 and the inclined cam surface 1 on each jaw 17 side.
7a comes into sliding contact.

Thus, each jaw 17 is rotationally displaced in the closing direction about the pin 18 as a rotation center as shown in FIG. 1B, and the outer peripheral surface of the other end Wb of the work W is firmly fixed by the outer diameter chuck method. Will be chucked.

As a result, the work W is supported at both ends as shown in FIG. 3, and as long as the head stock 1 is at the forward limit position and the sleeve 7 is at the forward limit position, the work W Is held centered by the center 20 and then chucked by the chuck 11.

Here, even if the diameter of the workpiece W to be chucked has a dimensional variation, the center ring 26 exhibits an equalizer function by so-called floating of the center ring 26 within the range of the play G described above. The jaws 17 serve to equalize the gripping force exerted on the work W. Thereby, the workpiece W having the dimensional variation can be reliably chucked as long as it is within the allowable dimension.

When the sleeve 7 shown in FIG. 3 is retracted during the unchucking operation, the center 20 is moved by the force of the return spring 24.
While moving forward with respect to 5, each jaw 17 returns to the unchucking state shown in FIG. 1A by the force of the return spring 19 to release the work W.

As described above, according to the present embodiment, the centering of the work W by the center 20 and the chucking operation of the work W by the jaws 17 are performed in a completely pure mechanically synchronized manner. Since the operation reliability is high and the slide stroke of the center 20 is converted into the rotational displacement of the jaw 17, the actuator has substantially the same function as the power chuck but does not require a conventional actuator. There is an advantage.

Here, by changing the angle of the inclined surface 26a of the center ring 26 and the inclined cam surface 17a on each jaw 17 side according to the size of the work W, etc., the gripping force of the work W, that is, chucking, is changed accordingly. It is possible to change the force. Further, by changing the position of the pin 18 supporting each jaw 17,
Can be adjusted.

[Brief description of the drawings]

FIG. 1 is a view showing an embodiment of a chuck of the present invention,
(A) is an explanatory sectional view of the unchucking state,
(B) is a sectional explanatory view of a chucking state.

FIG. 2 is a left side view of FIG.

FIG. 3 is an explanatory view showing a use state of the chuck shown in FIG. 1;

[Explanation of symbols]

 7 ... Sleeve 10 ... Spindle 11 ... Chuck 14 ... Shank part 15 ... Chuck body (chuck body) 17 ... Jaw (chuck claw) 17a ... Incline cam surface 18 ... Pin 20 ... Center 21 ... Shaft part 22 ... Center body 26 ... Center Ring (drive cam) 26a: inclined surface C: center hole W: work (crankshaft)

Claims (4)

[Claims] 1. A work having a plurality of jaws provided on a chuck body and a center provided at a center portion of the chuck body so as to be slidable in an axial direction thereof, and one end of which is supported by another support means. The chuck is characterized in that the other end is supported by the center, and the work is pushed into the chuck body together with the center, so that the jaw chucks the work according to the sliding displacement of the center to grip the work. . 2. A drive cam is provided between the jaw and the center, the drive cam being in contact with the inclined cam surface on the jaw side, and the jaw is driven by the drive cam at the end of a slide stroke of the center to perform a chucking operation. The chuck according to claim 1, wherein the chuck is provided. 3. The center and the drive cam are relatively movable in the axial direction of the center, and the center drives the jaws via the drive cam at the end of the slide stroke of the center. The chuck according to claim 2, wherein: 4. The drive cam is configured to be floatable with respect to the center, and the drive cam has an equalizing function for equalizing chucking forces of a plurality of jaws. Claim 3
Chuck described.