JPH031126Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a chuck for gripping rotary cutting tools such as drills and end mills.

(Prior Art) In the case of a spindle device, a cutting tool is held by a tool chuck, and this chuck is attached to the main shaft of the spindle device.

Here, the general chuck structure is
No. 33930, Publication No. 58-56086, No. 143107
As disclosed in No. 1, etc., a tool fitting sleeve whose outer circumferential surface is a tapered conical surface is provided at the tip of the chuck body, and a needle bearing whose axis is inclined with respect to the axis of the chuck body is mounted outside this sleeve. A rotary tube whose inner circumferential surface is an inner conical surface parallel to the outer circumferential surface of the sleeve is inserted through the sleeve, and the rotating tube is rotated to move in the axial direction, and this movement presses the outer circumferential surface of the sleeve, thereby releasing the sleeve. The inner diameter is reduced to firmly hold the tool inserted into the sleeve.

(Problem to be solved by the invention) In the conventional chuck described above, in order to securely hold the tool by the inner circumferential surface of the sleeve, the outer circumferential surface of the sleeve and the inner circumferential surface of the rotating cylinder are made parallel conical surfaces, and the outer circumferential surface of the sleeve Although the entire surface is pressed with a uniform force, it is difficult to process the sleeve so that the outer circumferential surface and the inner circumferential surface of the rotating cylinder are completely parallel, resulting in uneven tightening of the tool. The rotation may become unbalanced and the finish may be poor.

(Means for Solving the Problems) In order to solve the above problems, the present invention provides a collar which is provided on the outside of a tool fitting sleeve and whose outer peripheral surface is a tapered conical surface, and an inner peripheral surface of the collar or the sleeve. A groove-shaped oil chamber is formed on the outer circumferential surface at equal intervals in the circumferential direction and extends parallel to the axial direction in multiple grooves, and is rotatably attached to the outside of the collar via a bearing and moves forward and backward in the axial direction by rotation. The chuck is characterized by comprising a rotating cylinder that moves, a cylinder chamber formed within the chuck body and communicating with the groove-shaped oil chamber, and a piston that slides within the cylinder chamber in accordance with the forward and backward movement of the rotating cylinder. It is.

(Function) According to the present invention configured as described above, when the rotary cylinder is rotated and the rotary cylinder moves in the tightening direction, the piston slides within the cylinder chamber, and the hydraulic oil in the cylinder chamber flows around the inner circumference of the collar. The hydraulic pressure flows into the groove-shaped oil chambers, which are formed at equal intervals in the circumferential direction on the outer circumferential surface of the sleeve and extend parallel to the axial direction in multiple strips, and this oil pressure causes the outer circumferential surface of the sleeve to It is pressed with a uniform force in the diametrical direction along the axial direction at the location, thereby reducing the inner diameter of the sleeve and firmly holding the tool.

(Example) An example of the present invention will be described below based on the accompanying drawings.

Fig. 1 is a partially cutaway side view of the chuck according to the present invention, and Fig. 2 is a radial cross-sectional view of the chuck. A hole 3 into which a pull stud is inserted is bored in the tapered portion 2.

Further, a collar 4 is integrally formed at the tip of the chuck body 1 to protrude, and a sleeve 5 for fitting a tool is press-fitted into the inside of this collar 4 via a seal 6, and this sleeve 5 is secured by a pin 7. Chuck body 1
is fixed.

On the other hand, on the inner peripheral surface of the collar 4, a plurality of groove-shaped oil chambers 8...8 extending in the axial direction are formed at equal intervals in the radial direction.
Further, the outer peripheral surface of the collar 4 has a tapered conical surface, and the outer peripheral surface of the collar 4 is rotated via needle bearings 10...10 held by a retainer 9 and whose axis is slightly inclined with respect to the axis of the chuck body 1. Cylinder 1
1 is rotatably inserted. This rotating cylinder 11
The inner circumferential surface of the collar 4 is an inner conical surface parallel to the outer circumferential surface of the collar 4, and the outer circumferential surface is formed with a notch in which a rotating jig is engaged.
3, the rotating cylinder 11 is held. Further, a seal 14 is provided between the inner circumferential surface of the tip of the rotary cylinder 11 and the outer circumferential surface of the tip of the collar 4, and the needle bearing 1
This prevents chips, dust, etc. from entering the 0 part.

Furthermore, a cylinder chamber 15 is formed within the chuck body 1. This cylinder chamber 15 has a plug member 1.
Oil is supplied through the oil hole 17 sealed by the cylinder chamber 15, and the cylinder chamber 15 and the groove-shaped oil chambers 8...8 are connected through the communication hole 18. A piston 19 is slidably mounted thereon. This piston 19 has a buffer spring 20 interposed in its intermediate portion, and its tip protrudes from the chuck body 1. A ball bearing 21 is provided at the protruding tip. is in contact with.

In the above process, the rotary cylinder 11 is rotated in one direction (clockwise) with the base of the cutting tool inserted into the inner diameter hole of the sleeve 5. Then, since the axis of the needle bearing 10 is inclined with respect to the axis of the chuck body 1, the rotary cylinder 11 moves to the left in FIG. The diameter of the circumferential surface is reduced, and the oil pressure in the groove-shaped oil chamber 8 is increased. At the same time, as the rotary cylinder 11 moves to the left in FIG. 18 into each groove-shaped oil chamber 8, and due to the synergistic effect with the above, the oil pressure in the groove-shaped oil chamber 8 becomes even higher.

When the oil pressure in the groove-shaped oil chamber 8 increases, the outer peripheral surface of the sleeve 5 is pressed, and the inner diameter of the sleeve 5 is reduced to firmly hold the tool.

Further, when the rotary cylinder 11 is rotated in the opposite direction, the inner diameter of the sleeve 5 expands due to the opposite effect to that described above, as shown in FIG. 3, and the tool can be pulled out from the sleeve 5.

In the illustrated example, the groove-shaped oil chamber 8 is formed on the inner peripheral surface of the collar 4, but the groove-shaped oil chamber may be formed on the outer peripheral surface of the sleeve 5.

(Effect of the invention) As explained above, according to the invention, between the sleeve into which the tool is fitted and the outer collar of this sleeve, a plurality of strips parallel to the axial direction are spaced at equal intervals in the circumferential direction. A groove-shaped oil chamber extending from the cylinder chamber to the cylinder chamber is formed, and oil is supplied from the cylinder chamber to each groove-shaped oil chamber by rotating the rotary cylinder, so that the outer circumferential surface of the sleeve is formed at multiple points in the circumferential direction. The tool is pressed with a uniform force in the diametrical direction along the axial direction, thereby allowing the tool to be held with a uniform force by the inner peripheral surface of the sleeve. In addition, by rotating the rotary cylinder, the collar is also reduced in diameter, and this reduction in diameter also increases the pressure in the groove-shaped oil chamber, resulting in many effects such as being able to strongly hold the tool.

[Brief explanation of the drawing]

Fig. 1 is a partially cutaway side view of the chuck according to the present invention, Fig. 2 is a radial cross-sectional view of the chuck,
FIG. 3 is a sectional view showing the rotary cylinder rotated in the tool removal direction. 1...Chuck body, 4...Collar, 5...Sleeve,...Groove oil chamber, 10...Needle bearing, 11...Rotating tube, 15...Cylinder chamber, 1
9... Piston.

Claims (1)

[Scope of utility model registration request] A collar provided on the outside of the sleeve for inserting a tool and having an outer peripheral surface having a tapered conical surface, and a collar formed on the inner peripheral surface of this collar or the outer peripheral surface of the sleeve at equal intervals in the circumferential direction and extending parallel to the axial direction in multiple stripes. a groove-shaped oil chamber extending in the chuck body, a rotary cylinder that is rotatably attached to the outside of the collar via a bearing and moves forward and backward in the axial direction by the rotation thereof, and a rotary cylinder that is formed in the chuck body and communicates with the groove-shaped oil chamber. A chuck comprising a cylinder chamber and a piston that slides within the cylinder chamber according to the forward and backward movement of the rotary cylinder.