JPS639367Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a tool holder that allows fine adjustment of the radial dimension of the cutting edge of a tool for precision boring.

B. Prior art For example, in ultra-precision machining that involves finishing the inner diameter surface of a workpiece, in order to accurately align the workpiece surface and the cutting edge of a boring tool, the radial dimension of the cutting edge of the tool from the spindle center is finely adjusted. It is necessary to adjust the radial dimension of the cutting edge for each machining process, and also to prevent the cutting edge from contacting the machined surface and creating a so-called return mark that damages the machined surface when the tool returns after machining.

Conventionally, as a method of finely adjusting the radial dimension from the center of the cutting edge of a tool, a cam is interposed between the tool and a tool holder that holds the tool, as shown in Utility Model Application No. 55-75403. There is one that changes the position of the cutting edge by moving the blade. However, this method does not allow the radial dimension of the cutting edge of the tool to be made very small, making it impossible to machine small-diameter holes. In addition, the tool holder for this type of precision machining tool must have enough support rigidity to withstand the cutting reaction force during cutting and not cause vibration.

B. Purpose of the invention This invention is a tool that has support rigidity sufficient to withstand cutting reaction forces during cutting, allows fine adjustment of the radial dimension of the cutting edge of the tool in a short period of time, and is also capable of drilling small diameter holes. It is intended to provide a holder.

C. Structure of the device In this device, the outer circumferential surface 8a of the tip of the holding member 4 that holds the tool is formed into a spherical surface, the upper surface of the rear shaft portion 6 is formed with a slope of an appropriate angle, and the housing 12 that holds the holding member 4 is formed to have a spherical surface. The inner peripheral surface of the tip is formed into a spherical surface that supports the rear half of the spherical surface part 8a of the holding member 4, and holds the inner peripheral surface of the ring-shaped lid 28 that is attached to the front end surface of the housing 12 via the spacer ring 31. The front half of the spherical portion 8a of the member 4 is formed into a supporting spherical surface, and the thickness of the spacer ring 31 is selected to adjust the distance between the housing 12 and the lid 28 to apply an appropriate preload to the holding member. A lock ball 33 is interposed between the ring 31 and the holding member 4 under preload to prevent relative rotation in the circumferential direction, and is held by the adjusting member 22 slidably inserted into the housing 12. The members are made to be inclined.

D. Embodiment FIGS. 1 to 5 are drawings showing an embodiment of the tool holder of the present invention, in which 1 is a tool for boring the inner diameter surface 2a of the workpiece 2, and a A chip-shaped cutting blade 3 is attached. Reference numeral 4 denotes a holding member for holding the rear part of the tool 1, which is composed of a large-diameter holding part 5 and a small-diameter rear shaft part 6;
A fitting hole 7 is formed in the center thereof into which the rear part of the tool 1 is fitted from the front end surface, and a circumferential surface 8a of a flange 8 formed in a part of the outer circumferential surface is formed into a spherical shape. Further, screw holes 9, 9... are bored in several places on the wall of the holding part 5 toward the center, and these screw holes 9, 9...
The tool 1 is fixed to the holding member 4 by inserting screws (not shown) into the holes. The rear shaft portion 6 of the holding member 4 has an upper surface 6a formed as a flat surface, and a wedge-shaped cemented carbide plate 11 is fitted and fixed in a fitting groove 10 formed in the flat surface 6a along the axial direction, The upper surface of the plate 11 is sloped upward toward the rear. This slope is set to 1°, for example. Further, both rear end sides 6b and 6c of the shaft portion 6 and the lower surface 6d are formed into flat surfaces (see FIG. 5).

Reference numeral 12 denotes a cylindrical housing that supports the holding member 4, and a large-diameter coupling flange 13 is integrally formed on the rear outer peripheral surface. The inner circumferential surface 12a of the front end of the housing 12 is formed into a conical spherical surface 14 that widens forward to support the rear half of the center O of the spherical section 8a of the holding member 4.
2b is formed into a straight cylindrical surface. 15
is a large-diameter through hole formed from below toward the center of the coupling flange 13 of the housing 12; a telescopic pressing member 16 is inserted into this through hole 15, and a cap nut is screwed onto the outer opening end. The pressing member 16 and the cap nut 17 are prevented from coming off at 17.
A plurality of disk springs 18, 18, . Supporting force and holding member 4
is constantly biased in a counterclockwise direction. 19,20
are small-diameter through holes formed from both sides of the coupling flange 13 of the housing 12 toward the center. Distance pieces 21 and 21 are inserted into the through holes 19 and 20, respectively, and a cap nut 3 is inserted into the outer open end.
7 and 37 are screwed together to form the distance piece 2.
The tips of 1 and 21 are pressed against the flat surfaces 6b and 6c on both sides of the shaft portion 6 of the holding member 4 while allowing relative sliding of both 6 and 21, thereby preventing lateral vibration of the holding member 4 during cutting. .

Reference numeral 22 denotes an adjustment member inserted from the rear between the holding member 4 and the housing 12, the outer peripheral surface of which is formed into a cylindrical shape that can be slidably fitted into the cylindrical inner peripheral surface 12b of the housing 12, and the inner peripheral surface of the adjusting member 22. The surface is formed at an inner diameter facing the holding member 4 with an appropriate distance therebetween. Openings 23, 24, 25 are provided in the lower and both side walls of the adjusting member 22 facing the pressing member 16 and the distance pieces 21, 21 to allow the adjusting member 22 to move in the axial direction. A predetermined dimension is formed along the axial direction (see FIGS. 1 and 5). Reference numeral 26 indicates an adjustment member 22 corresponding to the plate 11 attached to the shaft portion 6 of the holding member 4.
As shown in FIG. 4, a pressing member such as an adjustment pin is inserted and fixed in the horizontal direction perpendicular to the axial direction on the upper wall of the plate 11, and constantly presses the upper surface of the plate 11 downward. They move back and forth as one, thereby swinging the holding member 4 vertically about the center O of its spherical portion 8a as a fulcrum, thereby adjusting the radial dimension of the cutting blade 3 at the tip of the tool. The amount of adjustment, that is, the movement dimension of the cutting blade 3 is determined by the amount of movement of the holding member 4 moved in the radial direction by the movement of the adjustment pin
The lever ratio between the amount of movement of the holding member 4, the axial dimension _l1 from the pivot center O of the holding member 4 to the adjustment pin 26, and the axial dimension _l2 from the pivot center O to the tip of the cutting blade 3, and the rear shaft section 6 It is set by the slope of The adjustment member 22
A suitable moving means, for example, a piston rod (not shown) of a moving cylinder is connected to the central shaft 27 at the rear, and the adjusting member 22 moves back and forth by the expansion and contraction of the moving cylinder to adjust the radial dimension of the cutting blade 3. adjust.

Reference numeral 28 denotes a ring-shaped lid body coupled to the front end surface of the housing 12, and its inner peripheral surface is formed into a spherical surface 29 that widens rearward to support the front half of the spherical surface portion 8a of the holding member 4 from the center O. The diameters of the spherical surface 29 of the lid 28 and the spherical surface 14 of the housing 12 are made slightly smaller than the diameter of the spherical surface portion 8a of the holding member 4. Reference numeral 30 denotes an O-ring mounted between the inner circumferential surface of the tip of the ring-shaped lid 28 and the holding member 4. 31
is a spacer ring interposed between the housing 12 and the lid 28, and its inner peripheral surface 31a is formed to have a slightly larger diameter than the outer diameter of the spherical part 8a of the holding member 4, so that there is a slight space between them. It is designed to cause This spacer ring 31 is designed to have an appropriate thickness and adjust the distance between the lid 28 and the housing 12, which are integrally attached to the housing 12 with bolts 32, so that the spherical surface of the holding member 4 can be adjusted between both 28 and 12. The portion 8a is held under constant pressure to provide sufficient supporting rigidity to receive the reaction force during cutting.

33, 33 are the spacer ring 31 and the holding member 4
A fixing member such as a lock ball interposed between the holding member 4 and the spacer ring 31 prevents the holding member 4 and the spacer ring 31 from rotating relative to each other around the central axis during cutting. These lock balls 33, 33 are spherical portions 8a of the holding member 4.
It is press-fitted between concave spherical or V-shaped locking grooves 34 and 35 formed opposite to each other at appropriate positions in the circumferential direction of the inner circumferential surface 31a of the spacer ring 31 (see FIG. 3). and the spacer ring 3
1 is slightly deformed in the radial direction, and its elastic restoring force applies preload to the lock balls 31, 31 to ensure that the relative relationship between the holding member 4 and the spacer ring 31 does not deform even when subjected to the reaction force during cutting. It is designed to prevent rotation and provide drive to the cutting blade 3. Note that each of the lock grooves 34 and 35 is connected to the holding member 4.
The diameter of the lock ball 31 is larger than that of the lock ball 31 so as to allow the rocking motion of the lock ball 31.

The housing 12 is attached to a slide base (not shown) using attachment holes 36, 36, . . . formed in the coupling flange 13.

To explain the operation in the above configuration, when finishing the inner diameter surface 2a of the workpiece 2, the moving cylinder of the tool holder is shortened in order to align the inner diameter surface 2a and the cutting blade 3, and the adjusting member 22 is moved back by a predetermined amount, and the holding member 4 is pressed downward via the plate 11 using the adjustment pin 26.
Then, the holding member 4 swings clockwise about the center O of the spherical portion 8a as a fulcrum, and moves the tip of the cutting blade 3 radially outward to align it with the workpiece 2. After that, while rotating the workpiece 2, the slide table with the tool holder fixed thereon is moved forward, and the cutting blade 3 is moved forward.
The workpiece 2 is bored. When the processing is completed, the moving cylinder is extended, the adjusting member 22 is slightly advanced, and the pressing of the holding member 4 by the adjusting pin 26 is released. Then, the holding member 4 is swung counterclockwise about the center O by the pushing force of the pressing member 16 and disc springs 18, 18 provided in the housing 12 and the adjusting member 22, and the cutting blade 3 is rotated. The cutting blade 3 is moved inward in the radial direction to provide a slight gap between the cutting blade 3 and the inner diameter surface 2a of the workpiece 2. In this state, move the slide table backward and cut the cutting blade 3.
is removed from the workpiece 2. Then, the machined workpiece 2 is removed from the rotating main shaft, a new workpiece 2 is attached, and the above operations are repeated to perform the process.

In the above embodiment, the case where processing is performed while rotating the workpiece 2 and not rotating the tool holder has been explained, but conversely, the case where processing is performed while the workpiece 2 is stopped and the tool holder is rotated is explained. It's good to wear. Further, the back and forth movement of the adjustment member 22 is not limited to the telescopic cylinder, but may be performed using any other appropriate reciprocating linear movement mechanism, or may be performed manually.

E. Effect of the invention In this invention, the spherical part of the holding member is supported by the spherical surface formed on the housing and the ring-shaped lid, so by tightening the housing and the lid, the holding member can be supported with an appropriate pressure, and cutting Accurate precision machining can be performed without rattling even when subjected to reaction forces, and when adjusting the position of the cutting blade, the holding member oscillates around the center of the spherical part as a fulcrum, so the oscillation is It is smooth and easy to adjust. In addition, the amount of adjustment of the radial dimension of the cutting blade is the amount by which the amount of movement of the holding member accompanying the movement of the adjustment member is expanded.
The inclination angle of the slope formed on the holding member can be made small, and the radial dimension of the cutting blade can be easily finely adjusted. Further, since an appropriate preload is applied to the lock ball interposed between the holding member and the spacer ring by utilizing the elastic force of the spacer ring, relative rotation between the holding member and the housing can be sufficiently prevented. I can do it.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal sectional side view of a tool holder according to the present invention, Fig. 2 is a front view of the tool holder, Fig. 3 is a sectional view taken along the line of Fig. 1, and Fig. 4 is a sectional view taken from Fig. 1.
A line sectional view, FIG. 5 is a line sectional view taken from FIG. 1. 1... Tool, 2... Workpiece, 3... Cutting blade,
4... Holding member, 6... Rear shaft portion, 11... Gradient plate, 12... Housing, 14... Spherical surface, 22... Adjustment member, 26... Adjustment pin, 28
...Ring-shaped lid body, 31 ...Spacer ring, 3
3...Rock ball.

Claims (1)

[Scope of utility model registration request] A holding member having an insertion hole for holding a tool in the center and having a spherical outer peripheral surface partially formed with a shaft portion at the rear of the holding portion, the upper surface of the shaft portion being sloped; and the holding member. A cylindrical housing having a spherical surface that supports the rear half of the spherical portion of the housing, and a pressing member that is slidably inserted between the holding member and the housing, and that a pressing member is provided on the inner circumferential surface of the housing so as to face the slope of the holding member. a ring-shaped lid body having a spherical surface supporting the front half of the spherical surface portion of the holding member on its inner circumferential surface and fixed to the front end of the housing via a spacer ring; and the spacer ring and the holding member A tool holder comprising a fixing member interposed between the two to integrate the two.