JPS62130109A - Automatically replaceable collet chuck - Google Patents

Abstract

PURPOSE:To enable the automatic replacement of a collet chuck and save energy by providing a collet having a grip groove for the gripper of a robot hand, etc., a collet engaging part, an engageable and removable claw body, and their driving means. CONSTITUTION:When a draw tube 4 is drawn by means of a driving device, the taper 5a of a collet 5 becomes an open condition being released from a taper hole. Then, when a pressure air is sent to the front chamber 7b of a cylinder 7, causing a piston 8 to be retracted to a main spindle side against a compression spring 17, a claw body 6 is outwardly moved by means of a bell crank lever 12 removing the engaging part 6a of the claw body 6 from the engaging part 5c of the collet 5. And, a collar 10 connected to the piston 8 is retracted, an approaching switch 16 is operated by means of a dog 11 and, due to an output signal and by means of a replacing arm of a robot or an ATC, a desired collet which is gripped out from a stocker, etc., is positioned in a replacing position, while the collet 5 is taken out with its grip groove 54 being gripped by another empty gripper, and the new collet is inserted and fixed.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a collet chuck that can be easily adapted to the diameter of a workpiece in a machine tool, particularly a lathe.

BACKGROUND OF THE INVENTION Jarret chucks are widely used as chucks for mass production of workpieces with fixed diameter dimensions. However, the collet of a collet chuck has an extremely narrow gripping range corresponding to the machining tolerance of the workpiece, so it must be replaced every time the diameter of the workpiece changes.

Problems to be Solved by the Invention Collets are prepared in numbers with different diameters depending on the workpiece to be machined, and are replaced manually when the workpiece is changed. For this reason, a lot of time was spent changing setups, which was a tedious task.

Means for Solving the Problem] A collet guide 3 inserted through the center of the let chuck body 2 is integrally connected with a draw tube 4 inserted through the center of the main shaft and movable in the axial direction. A collet 5 is opened and closed by the movement of the collet 5, and has an engaging portion 5C on its outer periphery and a gripping groove 5d for a gripper of a robot hand or an automatic tool changing arm at its outer end, and is provided in the collet chuck body 2 so as to be movable in the radial direction. The collet chuck body 2 is provided with a claw body 6 which can be engaged with and detached from an engaging portion of the collet 5, and driving means 7, 8, and 12 provided on the collet chuck body 2 to move the claw body 6.

Example Embodiments of the present invention will be described below based on the drawings.

A collet chuck body 2 is fitted onto the end face of a main shaft l of a lathe with a taper of 17 degrees, and a collet guide 3 having a tapered hole is slidably inserted into the center hole of the collet chuck body 2. The collet guide 3 is inserted through the main shaft so as to be movable in the axial direction and is integrally connected to a draw tube 4 that is moved back and forth by a drive device (not shown). and draw tube 4
With this movement, the collet 5 inserted into the collet guide 3 and having an outer taper 5a corresponding to the taper hole thereof is opened and closed. The collet 5 has an annular groove 5b on the outside of the taper 5a, and the main shaft side engaging surface 5c of the groove is an inclined surface such that the groove width at the back becomes wider, and further protrudes from the collet chuck body 2 on the outside. robot hand or AT at the end
A gripping groove 5d, which is gripped by the gripper 18 of the exchange arm C, is cut, the inner diameter is made to a size corresponding to the workpiece, and several cuts 5e are cut in the axial direction extending inward from the gripper a5d to the inner end. ing. The collet chuck body 2 has a claw body 6 which is slidable in the radial direction in several equal angular positions at a position corresponding to the engagement surface 5c of the annular groove 5b of the collet 5 fitted therein.
There are several. The inner end of the claw body 6 is inserted into the annular groove 5b of the collet with a back gap when the collet 5 is in the workpiece gripping state (the state shown in the figure), and is inserted into the engagement surface 5c.
The engaging surface 6a has an inclined surface that fits and fits in correspondence with the inclined surface of the engaging surface 6a, and an engaging notch 6b for a bell crank lever, which will be described later, is formed on the side surface on the main shaft side. The collet chuck body 2 is further provided with cylinders 7 parallel to the chuck axis in correspondence with the claws 6, and a space 2a is formed between the cylinders 7 and the claws 6. A piston 8 is fitted into the cylinder 7, and is always kept in the forward direction of the six claw bodies by a compression spring 17 inserted in the rear chamber 7a. A collar IO having an annular groove 10a cut therein is fixed to the end of the rod 9 of the piston 8 that penetrates the cylinder wall and extends into the space 2a.
) is attached to window 2 of collet chuck body 2.
I want b. and collar 10 or piston 8
An annular groove 10a of the collar 10 is used to transmit the movement to the claw body 6.
A bell crank lever 12 is pivotably supported by a support shaft 13 provided on the collet chuck body 2, and has a tip 12a that engages with the collet chuck body 2, a notch of the claw body 6, and an other end 12b that engages with the notch 6b. Further, a chuck cover 15 attached to a headstock 14 bearing the main spindle 1 is provided with a proximity switch 16 corresponding to the dog 1) for confirming opening/closing of the chuck.

When the working draw tube 4 is pulled by a drive device (not shown) and the collet guide 3 is in the retracted position, the taper 5a of the collet 5 is released from the taper hole and opened by its own elasticity. The front chamber 7b of the cylinder 7 is open to the atmosphere and there is no internal pressure, and the piston 8 is moved forward by the force of the compression spring 17, and the bell crank lever 12 is turned clockwise to engage the inner end of the claw body 6. Surface 6a
is inserted into the annular groove 5b of the collet 5.

When a workpiece is inserted into the collet 5 by a robot or a loader in this state, the draw tube 4 is advanced by a drive device (not shown) and pushes the tapered surface 5a of the collet 5, causing the inclined surface of the engaging portion 5c of the collet 5 to engage. The cut-out portion of the collet 5 is pushed inward due to its elasticity and deformed to firmly grip the workpiece because it comes into contact with the inclined surface of the inner end engaging surface of the body 6 and is stretched. Then, the main spindle 1 is rotated to cut the workpiece using a tool (not shown). This rotation of the main shaft 1 rotates the chuck, and centrifugal force acts to move the claw body 6 outward, but the retainers 5c and 6a are engaged on the inclined surface, and the collet 5 does not move in the axial direction, so the chuck is moved outward. The body 6 does not escape outward due to the spring force of the compression spring 17.

The workpiece is attached and detached by moving the draw tube 4 back and forth, but if the workpiece is changed within the range determined by the thickness of the collet guide 3, the robot needs to change the collet to match the workpiece. A matching collet stored in a stocker or tool magazine placed within the movement range is selected, and one gripper of the robot arm or one gripper of the ATC tween exchange arm grips the selected collet in the gripping groove 5d according to a command. grasp. On the other hand, on the left chuck side, the draw tube 4 is retracted so that a gap is left between the taper 5a surface of the collet 5 and the large taper surface of the collet guide 3, and pressure is applied to the front chamber 7b of the cylinder 7. Air is sent to move the piston 8 back toward the main shaft against the force of the compression spring 17. Since the collar 10 also retreats accordingly, the bell crank lever 12 is turned counterclockwise to move the pawl body 6 outward and release the engagement. During this movement, the engagement surface 6a of the claw body 6 causes the collet 5 to escape in the axial direction due to the force acting on the inclined surface, and the engagement state is released. When the collar 10 retreats, the dog 1) is positioned in front of the proximity switch 16, and a collar retreat confirmation signal is output from the proximity switch 16. This signal positions the robot arm or the ATC exchange arm to the exchange position, and the other empty The gripper grips the gripping groove 5d of the collet 5 and moves in the collet axial direction to take out the collet from the collet chuck body 2.The gripper rotates and the selected collet is positioned on the axis of the collet chuck. The collet is moved in the axial direction and inserted into the collet guide 3. cylinder 7
When the front chamber 7b of the front chamber 7b is opened to the atmosphere and the pressure is removed, the piston 8 and the accompanying collar 10 are advanced toward the claw body 6 by the force of the compression spring 17, and the bell crank lever 13 is rotated clockwise to center around the claw body 6. The engaging end of the claw body 6 is inserted into the annular groove 5b of the collet 5, and the collet 5 cannot be pulled out. The robot arm or exchange arm releases its grip and stores the exchanged collet in the striker or magazine.

Effects As detailed above, the present invention provides a collet with an annular groove in which the gripping groove of the exchange arm and the claw body engage, and a claw body that is inserted into the annular groove to fix the collet in the axial direction. Since a drive means is provided to move the collet in the radial direction, the collet stored together with the tool or separately and the collet on the main shaft can be replaced automatically by ATC without the need for manual replacement, resulting in unmanned operation and labor savings. This has the effect of shortening collet replacement time.

[Brief explanation of drawings]

The drawing is a longitudinal sectional view of the collet chunk of the present invention. 2. Collet chuck body

Claims (3)

[Claims] (1) A collet guide that is inserted through the center of the main shaft and is integrally connected to a draw tube that can move forward and backward in the axial direction, and that is inserted through the center of the collet chuck body. a collet having a gripping groove for a gripper of a robot hand or an automatic tool changing arm at the outer end of the joint; and a claw that is movably provided in the collet chuck body in a radial direction and is capable of engaging and disengaging with the engaging part of the collet. 1. An automatically replaceable collet chuck, comprising: a collet chuck body; and a driving means provided on the collet chuck body to move the claw bodies. (2) A patent in which the mutual engagement surfaces of the engaging portion of the collet and the engaging portion of the jaw body are inclined surfaces in the direction in which the jaw body does not move against the centrifugal force acting on the jaw body when the collet chuck rotates. An automatically replaceable collet chuck according to claim 1. (3) The automatically replaceable collet chuck according to claim 1, wherein the driving means is a bell crank lever that engages with the claw body and a hydraulic cylinder piston mechanism that acts to rotate the bell crank lever.