JPS5817681Y2 - tool holding chuck - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a tool holding chuck used in NC machine tools and the like.

In conventional tool holding chucks, a taper is formed on the inner circumferential surface of the chuck cylinder of the chuck body having a tapered shank, and a taper formed on the outer circumferential surface of the collet is brought into close contact with the inner circumferential surface of the chuck cylinder, so that the collet can be moved in the axial direction. It is slidably fitted into the chuck cylinder.

Therefore, when the shank of a tool such as a cutting tool is inserted into the collet and clamped, the collet and shank move in the axial direction due to the dimensional difference in the shank thickness of the tool, and the fitting depth of the shank into the chuck tube increases. The quality is different.

Therefore, there is a problem in that it is difficult to accurately measure the length from the tip of the spindle of a machine tool fitted with a taper shank to the tip of the tool, and that this dimension fluctuates each time the tool is replaced.

In particular, with tool holding chucks used in recent NC machine tools, the movement of the tip of the tool is programmed in advance by commands on the NC tape, so the length dimension of the tool used must be accurate to hold the tool in the chuck. There is a need,
There is a strong demand for a solution to the above-mentioned problems.

The present invention was developed in response to these demands, and is designed to reliably clamp the tool shank while always maintaining the desired depth of engagement, even if the shank of the tool has a difference in thickness. By providing a tool holding chuck that allows for easy clamping operations by simultaneously tightening the shank with the collet and pressing the shank with the clamping piece, we have developed a tool holding chuck that allows for easy clamping. The purpose of this is to enable the length to the tip of the tool to be accurately and easily maintained at a required dimension.

An embodiment of the present invention will be described below with reference to the drawings.

The chuck body 1 is provided with a taper junk 3 that is fitted onto the main shaft 2 of a machine tool on the distal end side, and a chuck tube 4 on the distal end side. A groove 6 is formed.

The collet 7 has a tapered outer circumferential surface, and split grooves 8 along the axial direction are formed at multiple locations in the circumferential direction, allowing the diameter to be reduced by elastic deformation. A locking protrusion 9 is formed.

By reducing the diameter of the collet 7, returning it to its original shape, and engaging the locking protrusion 9 in the annular groove 6 of the chuck tube 4, the collet 7 is prevented from moving in the axial direction, and the collet 7 is prevented from moving in the chuck tube 4. fitted inside.

A sleeve 10 is inserted between the inner circumferential surface 5 of the chuck tube 4 and the outer circumferential surface of the collet 7 so as to be slidable in the axial direction. A taper in the opposite direction is formed.

A cylinder 11 is screwed onto the outer circumferential surface of the tip of the chuck tube 4 and has a substantially cap nut shape, and the inner circumferential surface of the tip of the tube 11 protrudes from the tip of the chuck tube 4 and the chuck tube of the sleeve 10. 4 and the outer circumferential surface of the distal end protruding from the distal end surface of the collet 7, approximately half of the steel balls 12 are fitted so as to be freely movable. are engaged so as to be rotatable and prevented from moving in the axial direction.

A clamping piece 13 slides through the hole 14 formed in the chuck tube 4 in close contact with the hole 14 formed in the chuck tube 4 from the outside of the chuck tube 4, and also extends through an axially long notch 15 and a collet 17 formed in the sleeve 10. The inner end portion of the collet 7 protrudes from the inner surface of the collet 7 by passing through a hole 16 formed in the collet 7.

Further, a hemispherical pressing body 17 is fitted to the inner end of the clamping piece 13, and an outer end surface 18 of the clamping piece 13 protruding from the outer peripheral surface of the chuck tube 4 has a protruding length on the distal side. An inclined groove 19 is formed so that the outer end surface 18 becomes longer, and the bottom surface thereof is parallel to the slope of the outer end surface 18.

A clamp cylinder 20 is positioned outside the clamping piece 13 and fitted on the outer peripheral side of the chuck cylinder 4, and this clamp cylinder 2
A connecting member 23 consisting of a snap ring fitted onto the outer peripheral surface of the distal end of the cylindrical body 11 is rotatably and axially movably connected to the annular groove 22 on the inner surface of the distal end protrusion 21 of the cylindrical body 11. A spring 24 such as a disc spring is interposed between the distal end surface of the cylinder 20 and the end surface of the inner circumferential portion of the tightening cylinder body 11.

A tapered surface is formed on the inner circumferential surface of the clamp tube 20 so that the distal end side has a large inner diameter, and a linking pin 25 is protruded, and the tip end surface of the linking pin 25 is aligned with the inclined groove 19 of the clamping piece 13. It is slidably engaged with the bottom.

In addition, in the figure, 26 is a screw plug for supporting the steel ball 12, 27 is a cutting tool, 28 is a shank of the cutting tool 27, 29 is a rotation prevention notch surface provided on the shank 27, and 30 is a sleeve 10.
A seal member 31, such as cutting waste, is provided on the inner circumferential surface of the distal end of the chuck cylinder and contacts the outer circumferential surface of the cutting tool 27. Reference numeral 31 is the inner surface of the distal end of the chuck cylinder.

Next, the operation of the tool holding chuck configured as above will be explained.

Insert the shank 28 of the cutting tool 27 into the collet 7 to the desired depth.
When the tube body 11 is rotated, the sleeve 10 slides toward the distal end of the chuck tube 4 via the steel balls 12.

As the sleeve 10 slides, the collet 7 in close contact with the sleeve 10 is elastically deformed and reduced in diameter by both the tapers of the sleeve 10 and the collet 7, and the locking protrusion 9 of the collet 7 and the annular groove 6 of the chuck tube 4 Even if there is a slight gap in the axial direction between them, when the distal end surface of the collet 7 comes into contact with the distal inner surface 31 of the chuck tube 4, the collet 7 will not move toward the distal end side of the chuck tube 4, and in this state, the collet 7, the shank 28 of said tool 27 is loosely tightened.

Therefore, if the end surface of the collet 7 is in contact with the end inner surface 31 of the chuck tube 4, and the length of the tip of the main shaft 2 of the machine tool and the tip of the tool 27 is set to the required length, the collet 7 and the shank 28 of the tool 27, tightening causes the cylinder 11 to further spiral toward the distal end of the chuck cylinder 4, and the accompanying movement of the sleeve 10 absorbs the slack. shank 28 of the collet 7 and the tool 27 without displacing the collet 7 and the shank 28 of the tool 27 in the axial direction.
can be gripped and held by the chuck body 1.

In addition, the above-mentioned tightening is achieved by the screw movement of the cylinder 11, which causes the clamp cylinder 20 connected thereto to move toward the distal side of the chuck cylinder 4 via the spring 24, and the taper provided on the inner circumferential surface of the clamp cylinder 20 The surface presses the clamping piece 13 inward while sliding on the outer end surface 18 of the clamping piece 13.

For this purpose, the hemispherical pressing body 17 attached to the inner end of the clamping piece 13 presses against the detent notch surface 29 provided on the shank 28 of the tool 27.

Therefore, the shank 28 of the tool 27 and the collet 7, the collet 7 and the sleeve 10, and the sleeve 10 and the chuck tube 4
Of these, only the frictional resistance between the contact surfaces of the outer peripheral surface (or the end surface of the collet 7 and the chuck tube 4)
If the torque is not sufficiently transmitted from the shank 28 side of the tool 27 to the shank 28 side by the clamping piece 13,
The required torque can be transmitted from the main shaft 2 to the shearing of the tool 27.

To remove the tool 27 from the state in which the shank 28 of the tool 27 is attached to the chuck body 1, tighten the shank 28 of the cylindrical body 1.
1 is rotated in the opposite direction to the tightening direction and moved backward, the sleeve 10 is returned toward the tip of the chuck tube 4 via the steel ball 12, and the collet 7 is loosened accordingly. The collet 7 expands in diameter due to its elastic restoring force.

At the same time, as the cylinder 11 moves back, the clamp cylinder 20 is returned to the tip side of the chuck cylinder 4 via the connecting member 23 and the linking pin 25, and the clamp cylinder 20 is loosened. Accordingly, the tool 2 via the clamping piece 13
7 is released from being pressed against the shank 28.

Therefore, the tool 27 is removed by pulling out the shank 28 of the tool 27 from the collet 7.

In addition, in the present invention, if the diameter of the collet is to be reduced even after the axial movement is prevented, the collet may be configured to have a locking protrusion locked in the annular groove of the chuck tube as in the above-mentioned embodiment. Any suitable configuration can be used without limitation.

As explained above, the present invention brings the taper formed on the outer circumferential surface of the collet 7 into close contact with the taper formed on the inner circumferential surface of the sleeve 10, and tightens the chuck tube 4 of the chuck body 1 by tightening the chuck tube 4. By rotating the body 11, the diameter of the collet 7 is reduced through the sleeve 10 while being prevented from moving in the axial direction, and the shank 28 of the tool 27 can be tightened. Even if there is a dimensional difference, the collet 7 and shank 28 are always kept at the desired depth to fit the chuck tube 4 into the shank 28.
can be clamped.

Further, the tightening is performed by moving the clamp cylinder 20 smoothly by the linking pin 25 by moving the cylinder body 11 in the axial direction, and by moving the tapered surface provided on the inner circumferential surface of the clamp cylinder 20 by moving the reflamp corner piece 13. Since the pressing of the tool 27 against the shank 28 can be released, the clamping piece 13 and the collet 7 can be operated simultaneously, and the clamping operation and its release are easy.

Therefore, it is possible to easily maintain the length from the tip of the main spindle 2 of the machine tool to the tip of the tool 27 at the required dimension with simple operations, and it is possible to provide a tool holding chuck that is especially suitable for NCC machining. effective.

[Brief explanation of the drawing]

The figure is a partially longitudinal side view showing an embodiment of the present invention. 1...Chuck body, 2...Main shaft of machine tool, 3...Taper shank, 4...
・Chuck tube, 5... Inner peripheral surface of chuck tube, 7
...Collet, 10...Sleeve, 1
1... Tightening cylinder, 13... Clamp piece, 20... Clamp tube, 25...
Linking pin, 27...tool, 28...tool shank.

Claims (1)

[Scope of utility model registration request] a chuck body 1 having a taper shank 3 and a chuck tube 4; a radially expandable collet 7 fitted into the chuck tube 4 to prevent axial movement and having a tapered outer peripheral surface; A taper is formed on the inner peripheral surface of the chuck tube 4 so as to be slidable in the axial direction between the inner peripheral surface of the chuck tube 4 and the outer peripheral surface of the collet 7, and that is in close contact with the taper of the collet 7 in the opposite direction. A sleeve 10 and a sleeve 1 that is screwed onto the outer circumferential surface of the chuck tube 4 and is engaged with the sleeve 10 in a manner that allows rotation and prevents axial movement.
For tightening for zero movement, the shank 2 of the tool 27 is tightened by passing through the cylinder 11, the chuck cylinder 4, the sleeve 10, and the collet 7.
The clamping piece 13 abuts on the cylindrical body 1.
The clamp cylinder 20 is connected to the end side of the clamp piece 1 and slidably engages with the outer end slope of the clamp piece 13 on its inner circumferential surface to press the clamp piece 13 inward. Tool holding chuck.