JPS6338967Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Field of Application] This invention relates to a collect chuck used as a chuck on the inner circumference of a workpiece in a machine tool.

[Conventional technology]

Figure 2 shows a conventional collect chuck used in machine tools. In this collect chuck, a collet 1 whose tip is divided in the circumferential direction and whose diameter can be expanded and contracted is fixed to a cylinder 2, and the outer periphery of the cylinder 2 is attached to a bearing. 3 and supported by a frame 4 so as to be rotatable in the circumferential direction but immovable in the axial direction. A draw bar 5 is inserted through the collet 1, and a large diameter portion 6 is provided at the distal end of the draw bar 5, which can be fitted into the distal end of the collet 1 to enlarge the diameter of the distal end of the collet 1.
is provided. The drawbar 5 extends rearward from the base end of the collet 1, and a flange 7 is fixed to the base end. A plurality of disc springs 8 are interposed between the proximal end of the collet 1 and the flange 7, and the drawbar 5 is biased toward the proximal end of the collet 1. When the large diameter portion 6 of the drawbar 5 is drawn into the tip of the collet 1 by the disc spring 8, the tip of the collet 1 is expanded in diameter and can chuck the workpiece. A gear 9 is attached to the cylinder 2, and the gear 9 is connected to a drive source (not shown) via a gear 10 or the like. The collection chuck is rotated while chucking the workpiece.

An actuator 12 such as a hydraulic cylinder is provided at the base end of the frame 4 to project a rod 11 toward the base end of the drawbar 5.
When the base end of the drawbar 5 is pushed in step 1, the drawbar 5 moves forward, causing the large diameter portion 6 to come out of the collet 1, the diameter of the tip of the collet 1 is reduced, and the workpiece is anti-yacked. .

[The problem that the idea aims to solve]

With such conventional collect chucks, the axial position of the workpiece is fixed at the position where the workpiece is chucked, and even if it is desired to float the workpiece in the axial direction, it is impossible to float the workpiece.

The present invention has been developed in view of the above points, and its purpose is to provide a collect chuck that can float in the axial direction while maintaining chuck force while chucking a workpiece.

[Means to solve the problem]

In order to achieve the above object, the collector chuck of the present invention includes a cylinder rotatably but immovably supported in the main body via a bearing, and a cylinder that is coaxial with the cylinder and that rotates in the direction of rotation by the cylinder. A cylindrical collet to which power is transmitted and whose tip end diameter can be expanded and contracted; A drawbar extending into the cylinder, a flange provided at a proximal end of the drawbar extending rearward from the collet, and a rear end of the collet, the drawbar being connected to the collet. The collector chuck has a spring biasing the drawbar in the proximal direction, and the main body is provided with a rod protruding toward the proximal end of the drawbar, and an actuator for driving the rod. An outer cylinder is fixed to the distal end surface of the cylinder coaxially with the cylinder, the inner circumferential surface of the outer cylinder is slidably fitted to the outer circumferential surface of the collet, and the collet, drawbar, spring, and flange are fixed to the cylinder. The rod and actuator are attached to a frame having a guide bar that is loosely fitted into the main body, and the tip of the guide bar has an engagement member that engages with the outer cylinder. It is characterized by having a section.

[Effect]

According to the above configuration, it is possible to float the workpiece in the axial direction while chucking it, and it is also possible to anti-chuck the workpiece without applying any load to the bearing.

〔Example〕

An embodiment of the collect chuck according to the present invention will be described below with reference to the drawings. In the figures, the same or equivalent parts as in the conventional example are designated by the same reference numerals.

FIG. 1 shows an embodiment of the present invention. In this figure, the frame 4 has a guide bar 14 that slidably passes through the main body 13 and is provided parallel to the drawbar 5.
and a bracket 1 fixed to the base end of the guide bar 14 and to which the actuator 12 is attached.
5 and a bracket 16 fixed to the tip of the guide bar 14, and the frame 4 is slidable in the axial direction with respect to the bearing 3. A stepped portion 1a is formed near the tip of the collet 1, and a convex portion 1 that engages with this stepped portion 1a is formed.
The inner circumferential surface of the outer cylinder 17 on which the outer tube 7a is formed is slidably fitted to the outer circumferential surface of the collet 1. A flange portion 17b is formed at one end of the outer cylinder 17 in the proximal direction, and this flange portion 17b is fixed to the end surface 2a of the cylinder 2 in the distal end direction.
The tip of the guide bar 14 is fixed to a bracket 16, and an engaging portion 18 is provided on the bracket 16 at a position facing the flange portion 17b of the outer cylinder 17. An outer cylinder 19 is slidably fitted to the outer periphery of the portion of the drawbar 5 inside the cylinder 2, and one end of the outer periphery 19 in the distal direction abuts one end of the collet 1 in the proximal direction. One end of the outer cylinder 19 in the proximal direction faces the flange 7 with a predetermined distance therebetween. A plurality of disc springs 8 are provided between the outer periphery of the outer cylinder 19 and the inner periphery of the cylinder 2, and urge the drawbar 5 toward the proximal end with respect to the collet 1 via the flange 7. are doing.

The operation of one embodiment of the present invention constructed as described above will be described below. When chucking, the drawbar 5 is moved to the right in the figure via the flange 7 by the disc spring 8, and the large diameter part 6 formed at the tip of the drawbar 5 expands the taper part at the tip of the collet 1 to tighten the workpiece. Checking the inner diameter is the same as in the conventional example, but in this example, the collet 1, drawbar 5, flange 7, disc spring 8, etc. that make up the chuck part can slide in the axial direction within the cylinder 2. Therefore, it is possible to move to the right within a certain range while maintaining the chuck force. In other words, it is floating in the axial direction.

At the time of anti-yuck, the actuator 12 is actuated to move the rod 11 forward in the direction of the tip, and the tip of the rod 11 comes into contact with the end of the drawbar 5. At this time, the biasing force of the disc spring 8 is strong, so the actuator 12, the bracket 15, and the guide bar 1
4. When the bracket 16 and the engaging part 18 move together to the right with respect to the main body 13 and the engaging part 18 comes into contact with the surface of the flange part 17b, the force of the actuator 12 overcomes the biasing force of the disc spring 8. Then push the drawbar 5 to the left to open the collet 1 and anti-yack the workpiece. In such a configuration, the axial force is transmitted to the collet 1 via the bracket 15, the guide bar 14, the bracket 16 and the engaging portion 18, independently of the bearing 3.

A hydraulic motor 20 is attached to the main body 13, and the cylinder 2 is rotationally driven by the hydraulic motor 19 via gears 9, 10, and 21. Further, depending on the posture of the collector chuck, springs may be inserted between the main body 13 and the actuator 12 and between the collector 1 and the cylinder 2 in order to support the weight of the cylinder portion and the collector portion, respectively.

[Effect of idea]

As described above, according to the present invention, the collet, drawbar, flange, disc spring, etc. that make up the chuck part can all slide in the axial direction within the cylinder, so that the axial length of the workpiece can be adjusted. Even if the load changes, the chuck part can now float in the axial direction while maintaining the chuck force in response to the change, and at the same time, no load is applied to the bearing during anti-chuck, so this is highly effective. It is.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal cross-sectional view showing one embodiment of a collector chuck according to the present invention, and FIG. 2 is a longitudinal cross-sectional view showing a conventional collector chuck. 1... Collet, 2... Cylinder, 3... Bearing, 4... Frame, 5... Drawbar, 6
...Large diameter section, 7...Flange, 8...Disc spring,
9, 10... Gear, 11... Rod, 12... Actuator, 13... Main body, 14... Guide bar, 15, 16... Bracket, 17... Outer cylinder,
18... Engaging portion, 19... Outer cylinder, 20... Hydraulic motor, 21... Gear.

Claims (1)

[Claims for Utility Model Registration] A cylinder rotatably but immovably supported in the axial direction via a bearing in the main body; A cylindrical collet whose diameter can be expanded or contracted, and a collet which can be fitted into the tip of the collet from the outside to expand the diameter of the tip of the collet, and which extends into the cylinder through the axial center of the collet. a flange provided at a proximal end portion of the drawbar extending rearward from the collet and a rear end portion of the collet; and a spring for biasing the drawbar, and the main body is provided with a rod protruding toward the base end of the drawbar, and an actuator for driving the rod. An outer cylinder is fixed coaxially with the cylinder, the inner circumferential surface of the outer cylinder is slidably fitted to the outer circumferential surface of the collet, and the collet, drawbar, spring, and flange are slidable in the axial direction with respect to the cylinder. On the other hand, the rod and the actuator are attached to a frame having a guide bar that is loosely fitted into the main body, and an engaging part that engages with the outer cylinder is provided at the tip of the guide bar. This is a collection feature that is characterized by: