JPH065811U - Tool clamping device for machine tools - Google Patents

Abstract

(57) [Summary] [Purpose] When mounting a deep hole drilling tool on a collet chuck provided on the spindle of a machine tool, attach it closely without creating a gap on the contact surface between the two. A chuck base fixed to one end of a main shaft rotatably supported by a machine tool and having an insertion hole, and a chuck base movably inserted in the main shaft axis direction. A sleeve having a through hole and a tapered hole portion having a large diameter on the one side is provided on the inner peripheral portion, and a taper portion that abuts the tape hole portion of the sleeve is formed on the inner peripheral portion on the outer peripheral portion of the sleeve. Then, when the sleeve moves to the one side, it is attached to the chuck base body that grips the shank of the tool by elastic deformation of the collet, restricts the axial movement of the collet, and contacts the collar portion of the tool. A cover body that is in contact with and axially positioned, and is arranged in the radial direction of the sleeve, is biased toward the spindle center line, engages with the engagement groove of the tool, and the tool is opposed to the spindle. An engaging member for pressing the other side of the axial Te.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a machining tool, and more particularly to a tool clamping device for a machine tool capable of reliably clamping a deep hole machining tool on a collet chuck of a spindle.

[0002]

[Prior art]

 When mounting a deep hole drilling tool that performs deep hole drilling, insert the shank part at the rear end of this deep hole drilling tool into the collet chuck on the spindle side, and tighten the collet chuck in the radial direction. Clamping by force is common practice. Such a deep hole machining tool is generally long, and has a cylindrical shape with a recovery hole for recovering chips together with the cutting agent inside. This recovery hole must be drilled with a specified diameter so that chips can be easily recovered together with the cutting agent, and the shank portion of this deep hole machining tool is a straight shank. For example, a clamp mechanism for a collet chuck of such a deep hole machining tool is described in Japanese Patent Application Laid-Open No. 2-311208 previously proposed by the present applicant.

[0003]

[Problems to be solved by the device]

 However, in such a machine tool for deep hole drilling, when a deep hole drilling tool is mounted in the collet chuck and clamped only by the radial tightening force, there is no pressing force in the spindle axis direction. Since it is clamped in a state where it is tilted due to its own weight, etc., a gap was likely to be created between the front end of the collet chuck and the shank collar of the deep hole machining tool. Therefore, there is a problem that the machining dimension in the direction of the axis of the spindle varies. This invention was devised to solve the above-mentioned problems, and its purpose is to prevent a gap from being formed in the spindle axis direction between a deep hole machining tool having a straight shank portion and a collet chuck. The present invention provides a tool clamping device for a machine tool, which improves the machining accuracy in the axial direction of a machining hole in a workpiece.

[0004]

[Means for Solving the Problems]

 The object of the present invention is to form a through hole in the axial direction to extend a hole for making a hole in a workpiece, to provide a cutting edge portion at one end and to hold a radial end at the other end. A tool clamp for a machine tool equipped with a tool having a straight shank formed of an outer peripheral portion, a flange portion continuous to the outer peripheral portion, and an engaging groove formed in a part of the outer peripheral portion. In the device, a main shaft rotatably supported by the base of the machine tool, a chuck base fixed to one end of the main shaft and having an insertion hole, and an insertion hole of the chuck base. A sleeve that is movably inserted in the spindle axis direction and that has a through hole in the inner peripheral part and a tapered hole part with a large diameter on the one side, and a sleeve inserted into the inner peripheral part of the sleeve and the outer peripheral part. A taper portion that contacts the tape hole portion of the sleeve is formed, and the taper portion is formed. When the tab moves to the one side and the taper hole presses the taper, it is attached to the collet that holds the straight shank by elastic deformation and the chuck base, and restricts the movement of the collet in the axial direction. In addition, the cover body that comes into contact with the collar portion of the tool to perform axial positioning and the radial direction of the sleeve is constantly urged toward the spindle center line to form the engagement groove of the tool. It can be achieved by a tool clamping device for a machine tool, characterized in that it has an engaging member that engages with the tool and presses the tool to the other side in the spindle axis direction with respect to the spindle.

[0005]

[Action]

 The tool clamp device of the machine tool of the present invention inserts the straight shank of the deep hole machining tool into the collet chuck with the sleeve moved to the unclamp position. Then, when the sleeve is moved to the clamp position, the collet radially tightens the outer periphery of the straight shank, and the tip of the engaging member provided on the sleeve engages with the engaging groove of the straight shank. The deep hole drilling tool is pressed and clamped in the direction of the spindle axis. Therefore, there is no gap between the spindle axis and the shank collar of the deep hole machining tool, and the machining accuracy in the spindle axis direction is improved.

[0006]

【Example】

 FIG. 1 is a cross-sectional view of a main shaft portion provided with a tool clamp device of the present invention. FIG. 2 is an enlarged sectional view of the clamp mechanism portion according to the present invention. A tool clamp device for a machine tool of the present invention will be described below based on an embodiment shown in the drawings. A spindle 1 is rotatably supported by a spindle headstock 13 of a machine tool. A chuck base body 3 having a through hole 3a is fixed to the front surface side of the main shaft 1 with a bolt 2. A sleeve 6 is inserted into the through hole 3a for opening and closing the collet 4 incorporated in the through hole 3a. One end of this sleeve 6 is screwed to a draw tube 10, which is a sliding member in the main shaft 1. A hole portion 6b is formed in the sleeve 6, and an engaging member 7 having an engaging portion protruding from the inner peripheral surface of the sleeve 6 is fitted in the hole portion 6b so that the engaging portion can be retracted. ing. The engaging member 7 is constantly urged by a spring 8 toward the main shaft center line, and the spring 8 is fixed by a set screw 9. In this embodiment, the engaging member 7 is formed of a steel ball. By providing a plurality of the engaging members 7 evenly on the circumference of the sleeve 6, the engaging groove ends 11d of the deep hole drilling tool 11 can be pressed in the spindle axis direction of the plurality of engaging members 7. Hole machining The straight shank portion 11a can be firmly fixed while the shank collar portion 11c of the tool 11 is reliably brought into contact with the front cover 5 of the spindle 1. For example, a hole 6b is bored at a position where the circumference of the sleeve 6 is divided into three parts, and an engaging member 7 and a spring 8 are internally fitted into each hole and fixed by a set screw 9.

The deep hole drilling tool 11 is a BTA type tool, and a through hole is also formed in the straight shank portion 11a so as to be collected through the through hole 3a together with the cutting agent cut by the tip edge portion 11e. is there. An engaging groove 11b with which the tip of the engaging member 7 engages is formed near the end of the straight shank portion 11a. When the engaging groove 11b of the engaging member 7 is in contact, the shank flange portion 11c of the deep hole machining tool 11 and the front end surface 5a of the front cover 5 are in contact with each other. Reference numeral 14 is a chuck cylinder provided at the rear portion of the main shaft 1, and a piston 15 is connected to a draw tube 10 penetrating the main shaft 1. It is partitioned by the chuck cylinder 14 and the piston 15 to form a first cylinder chamber 14a and a second cylinder chamber 14b.

The operation of the tool clamping device of the present invention thus constructed will be described. The collet 4 supplies pressure oil to the first cylinder chamber 14a side of the chuck cylinder 14, moves the piston 15 backward (moves to the right in FIG. 1), and the sleeve 6 in the chuck base body 3 fixed to the main shaft 1 is drawn. Since it retracts together with the tube 10, the elasticity of the collet 4 itself causes the collet 4 to open. In this state, the tool exchanging of the deep hole machining tool 11 is performed by an automatic tool exchanging device (not shown), and the straight shank portion 11a of the new tool is inserted into the collet 4. After the insertion, when pressure oil is supplied into the second cylinder chamber 14b of the chuck cylinder 14, the piston 15 moves leftward in FIG. 1, and the sleeve 6 moves leftward (FIG. 1) through the draw tube 10, The taper portion 6a presses the collet 4 in the radial direction, and the collet 4 tightens the deep hole machining tool 11. At this time, the plurality of engaging members 7 provided on the sleeve 6 are engaged in the engaging groove 11b. Therefore, the engagement groove 11b at the rear end of the deep hole machining tool 11 can be pressed by the engagement member 7 in the spindle axis direction. Therefore, the deep hole machining tool 11 can be firmly clamped in the collet 4 without forming a gap between the shank collar portion 11c of the deep hole machining tool 11 and the front end portion 5a of the front cover 5. Since the shank collar portion 11c of the deep hole drilling tool 11 and the front end portion 5a of the front cover 5 are always in accurate contact with each other in this manner, the clamping accuracy of the deep hole drilling tool 11 in the spindle axis direction is improved, The processing accuracy of the object w has also been greatly improved.

[0009]

[Effect of device]

 The tool clamping device of the machine tool of the present invention grips the straight shank portion of the deep hole machining tool with the collet, and the clamping members are always biased toward the main shaft side by the plurality of engaging members arranged on the peripheral surface of the shank. Maintained in position. Therefore, the spindle end and the shank collar of the deep hole machining tool abut each other without forming a gap. Further, there is an excellent effect that the machining dimension of the workpiece in the axial direction of the spindle is not varied.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a main shaft portion provided with a tool clamp device of the present invention.

FIG. 2 is an enlarged sectional view of a holding mechanism portion according to the present invention.

[Explanation of symbols]

 1 ... Spindle 2 ... Bolt 3 ... Chuck base 4 ... Collet 5 ... Front cover 6 ... Sleeve 7 ... Engaging member 8 ... Spring 10 ... Draw tube 11 ... Deep hole processing tool 11b ... Engaging groove 11c ... Shank collar 13 ... Headstock 14 ... Chuck cylinder 15 ... Piston

Claims (1)

[Scope of utility model registration request] 1. A hole is formed in a workpiece, a through hole is formed in the axial direction to extend, and a cutting edge portion is provided at one end.
A tool having a straight shank formed of an outer peripheral portion gripped in the other end in the radial direction, a brim portion continuous to the outer peripheral portion, and an engaging groove formed in a part of the outer peripheral portion. In a tool clamp device for a machine tool to be mounted, a main shaft rotatably supported by a base of the machine tool, a chuck base body fixed to one end of the main shaft and having an insertion hole, A sleeve that is movably inserted in the main shaft axis direction into the insertion hole of the base body and has a through hole and a tapered hole portion having a large diameter on the one side on the inner peripheral portion; and a sleeve that is inserted into the inner peripheral portion of the sleeve. A taper portion that contacts the tape hole portion of the sleeve is formed on the outer peripheral portion, and when the sleeve moves to the one side and the taper hole portion presses the taper portion, a collet that grips the straight shank by elastic deformation. A cover body that is attached to the chuck base body, restricts the movement of the collet in the axial direction, and contacts the collar portion of the tool to perform axial positioning, and always in the radial direction of the sleeve, An engaging member that is biased toward the spindle center line, engages with the engagement groove of the tool, and presses the tool to the other side in the spindle axis direction with respect to the spindle. Tool clamping device for machine tools.