JPH0480762B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION "Field of Industrial Application" The present invention relates to an indexable cutting tool in which an indexable tip is detachably attached to a tool body.

``Prior Art'' Conventionally, as shown in FIGS. 14 and 15, this type of throw-away cutting tool has a throw-away tip 2 seated in a groove-shaped tip seat 1a of a tool body 1, A structure is known in which a hexagon socket head screw 3 is inserted into the mounting hole 2a of the throwaway chip 2 and screwed into the female threaded portion 1b of the chip seat 1a.

"Problem to be Solved by the Invention" However, in the case of the above-mentioned throw-away type cutting tool, when it becomes necessary to replace the throw-away tip 2, the screw 3 must be completely removed from the tool body 1. However, at that time, the removed screw 3 was sometimes lost. In addition, since screw 3 cannot be removed or installed without turning it a considerable number of times, it is extremely difficult to work with, and it takes a lot of time to replace the tip. It was used as a measuring tool for cutting tools such as cutters equipped with a tip 2.

This invention was made in view of the above circumstances,
To provide a throw-away cutting tool whose throw-away tip can be easily and quickly replaced without completely removing the screw from the tool body.

``Means for Solving the Problems'' In order to achieve the above object, the present invention provides a throw-away chip with a mounting hole formed in the throw-away chip, the diameter of which increases as it goes toward the end. In the throw-away type cutting tool, the throw-away tip is removably attached to the tool body by inserting a screw into the attachment hole, and the tool body has an elastic deformation portion. The collet is mounted with its elastically deformable portion protruding from the tip seat of the tool body, and the elastically deformable portion has an outer diameter smaller than an inner diameter of the attachment hole of the throwaway tip in a free state, The tool has a tapered shape whose diameter increases toward the end, and is configured to engage and abut an enlarged portion of the mounting hole of the throw-away tip in the expanded state. The throwaway chip is seated on the chip seat of the main body with the collet fitted into its mounting hole, and the head of the throwaway chip is seated on at least one of the collet and the tool main body in a screwed state. By expanding the elastic deformation portion of the collet at the enlarged portion and engaging and abutting the enlarged portion of the mounting hole of the throw-away tip, the screw fixing the throw-away tip to the tool body can be tightened and loosened freely. It was worn.

"Function" In the throw-away cutting tool of the present invention, the elastic deformation part of the collet is expanded by the enlarged part of the head of the screw, and the elastic deformation part engages with the enlarged part of the mounting hole of the throw-away tip. The throw-away tip is fixed to the tip seat of the tool body. If you want to replace the throw-away tip in this state, loosen the screw to release the elastically deformed part of the collet, pull the throw-away tip out of the collet, replace it with a new one, and then tighten the screw again. Fix it on the tip seat.

"Example" The first embodiment of the present invention will be described below in Figures 1 to 4.
This will be explained with reference to the figures.

In the figure, reference numeral 10 denotes a tool main body, and a recessed groove-shaped chip seat 12 into which the throw-away chip 11 is fitted is formed on the edge of the upper surface of the tool body. The upper end is tip seat 1
A through hole 13 having a circular cross section and opening at the bottom of the tool body 10 and having a lower end opening at the lower surface of the tool body 10 is formed. This through hole 13 has a small diameter portion 13a on the upper end side and a large diameter portion 13b on the lower end side, and a threaded portion 13c is formed at a lower portion of the large diameter portion 13b. 14 is fitted.

The collet 14 has a cylindrical shape with a constant inner diameter, and has a thick wall on the root end side and a thin wall on the distal end side, and the thick wall portion 14a is fitted into the large diameter portion 13b of the through hole 13. , its thin part 1
4b fits into the small diameter portion 13a of the through hole 13, and its upper end side protrudes upward from the chip seat 12.
A plurality of (four in the figure) slits s extending downward at equal intervals in the circumferential direction are formed in the portion that protrudes upward from the tip seat 12, and the upper end of the slit s extends downwardly at equal intervals in the circumferential direction. It has an outer diameter smaller than the inner diameter of the mounting hole 11a of No. 11, and has a tapered shape that gradually increases in diameter toward the top, and this upper end is elastically expanded from the inside. This serves as an elastically deformable portion 15.

Furthermore, a fastening member 16 shorter than the length of the threaded portion 13c of the through hole 13 is screwed with its upper end surface abutting the lower end surface of the collet 14, and the presser member 16 ' is screwed with its upper end surface in contact with the lower end surface of the fastening member 16. A screw hole 16a is formed in the fastening member 16 at its axis coaxial with the collet 14 and having the same inner diameter as the inner diameter of the root end side of the collet 14.

In addition, the tip seat 12 of the tool body 10 includes:
The throwaway chip 11 has a mounting hole 11a with a tapered enlarged part 11b whose diameter increases as the upper end side goes upward. Inserted and seated, collection 14
The elastic deformation portion 15 is the enlarged portion 1 of the mounting hole 11a.
It's stuck in 1b. A screw 17 having an enlarged portion 17a on its head is fitted into the inside of the collet 14, and the lower end of this screw 17 is screwed into a screw hole 16a of a fastening member 16 in a manner that allows it to be tightened and loosened freely. The enlarged portion 17a of the head of the screw 17 expands the elastically deformable portion 15 of the collet 14 from the inside to the outside to open the mounting hole 11 of the throwaway tip 11.
It is brought into engagement contact with the enlarged portion 11b of a.

As shown in FIG. 2, the axis of the throw-away tip 11 is slightly eccentric with respect to the axis of the collet 14, etc., and when the throw-away tip 11 is seated on the tip seat 12 and the screw 17 is tightened, By tightening the screw 17, the throwaway tip 11 is pressed against the side wall of the tip seat 12.

Therefore, in the throw-away cutting tool having the above configuration, the throw-away tip 11 is the first tip.
It is fixed to the tool body 10 as shown in the figure. That is,
In FIG. 1, the screw 17 is screwed to a fastening member 16 that is screwed to the tool body 10, and the enlarged portion 17a of the head of the screw 17 is connected to the collet 14.
The elastically deformable portion 15 is expanded to engage and abut the enlarged portion 11b of the attachment hole 11a of the throwaway tip 11, thereby fixing the throwaway tip 11 to the tip seat 12.

When replacing the throw-away tip 11 with a new one from this state, loosen the screw 17 to the extent that the enlarged portion 17a of the head part separates from the elastic deformation portion 15 of the collet 14. Then, the elastically deformable portion 15 of the collet 14 is released from its expansion and returns to its free state, but since the outer diameter of the elastically deformable portion 15 of the collet 14 in the free state is smaller than the inner diameter of the mounting hole 11b of the throwaway tip 11. , the throw-away tip 11 can be easily pulled out upward as shown in FIG. To install a new throw-away chip 11, fit the screw 17 protruding from the chip seat 12 and the upper end of the collet 14 into the mounting hole 11a, seat the throw-away chip 11 on the chip seat 12, and then tighten the screw 17. Fastening member 16
Just screw it in place.

In this way, in the case of the above-mentioned throw-away type cutting tool, the throw-away tip 11 can be removed by simply loosening the screw 17 slightly without removing it from the tool body 10 side, and the throw-away tip 11 can also be attached. This can be done by simply seating the chip on the chip seat 12 and retightening the slightly loosened screw 17. Therefore, it is not necessary to rotate the screw many times to attach and detach the screw as in the past, which greatly speeds up the chip replacement work, and also prevents the removed screw from being lost. There is no risk of stains when it is put away, and work efficiency is significantly improved.

Next, some other embodiments of the above cutting tool will be described.

FIG. 5 shows a second embodiment in which the holding member in the first embodiment is omitted and the fastening member 16 is made longer.
Further, FIGS. 6 to 9 show a third embodiment, in which the sheet 18 forming the chip seat 12 is connected to the tool body 10 via the collet 19.
The collet 19 has a threaded portion formed on its outer periphery and is screwed to the tool body 10, while the screw 17 is screwed directly to the tool body 10 without using a fastening member so that it can be tightened or loosened. has been done. Furthermore, in the fourth embodiment shown in FIGS. 10 and 11,
A screw hole 20a is formed inside a collet 20 which is screwed and fixed to the tool body 10, and a screw 17 is screwed into the collet 20 itself so that it can be tightened or loosened.

Furthermore, in the fifth embodiment shown in FIG. 12, the tip seat 12 is not formed into a groove shape in the third embodiment, but is formed on the same plane as the upper surface of the tool body 10.
The sixth embodiment shown in FIG. 13 is the same as the fifth embodiment except that the sheet 18 is omitted.

Furthermore, although not shown, enlarged portions 11b are provided at both ends of the mounting hole 11a of the throwaway tip 11.
By forming the throwaway tip 1
1 can be fixed on both sides. Also, screw 1
By making the threaded portion 7 a multi-thread thread, the number of turns of the screw 17 when exchanging the chip can be reduced, and the exchanging work can be further speeded up.

"Effects of the Invention" As explained above, in the throw-away cutting tool of the present invention, a mounting hole is formed in the throw-away tip, and the end of the mounting hole has a taper whose diameter increases toward the end. The throw-away tip is removably attached to the tool body by inserting a screw into the attachment hole, and a collet with an elastic deformation section is formed on the tool body. The elastically deformable portion is attached so as to protrude from the tip seat of the tool body, and has an outer diameter smaller than the inner diameter of the attachment hole of the throwaway tip in a free state, and expands toward the end. It has a tapered shape and is configured to engage and abut an enlarged portion of the mounting hole of the throwaway tip in an expanded state;
The throw-away tip is seated on the tip seat of the tool body with the collet fitted into its mounting hole, and the head of the throw-away tip is seated on at least one of the collet and the tool body in a screwed state. By expanding the elastic deformation part of the collet at the enlarged part of the part and engaging and abutting the enlarged part of the mounting hole of the throw-away tip, the screw fixing the throw-away tip to the tool body can be tightened and loosened. Since the collet is screwed onto the tool body, the collet with the elastic deformation part is attached to the tool body.
By expanding the elastic deformation part by the enlarged part of the head of the screw and engaging and abutting this elastic deformation part with the enlarged part of the mounting hole of the throw-away chip, the screw head is perpendicular to the axis of the throw-away chip and its mounting hole. The throw-away tip can be pressed not only in the axial direction of the mounting hole, but also in the axial direction of the mounting hole.Therefore, the throw-away tip can be firmly fixed to the tool body, and there is no need to attach or remove screws as in the conventional case. Chip replacement work can be greatly speeded up, there is no risk of damage if the removed screw is lost, and work efficiency is significantly improved.

[Brief explanation of drawings]

1 to 4 show a first embodiment of the present invention, in which FIG. 1 is a cross-sectional view with the throw-away tip fixed, FIG. 2 is a cross-sectional view with the throw-away tip removed, Fig. 3 is a partially cutaway side view of the collet, Fig. 4 is a view taken in the direction of - arrow in Fig. 3, Fig. 5 is a sectional view showing the second embodiment, and Figs. Fig. 6 is a sectional view of the throw-away tip fixed, Fig. 7 is a sectional view of the throw-away tip removed, Fig. 8 is a partially cutaway side view of the collet, and Fig. 8 is a sectional view of the collet. 9 is a view taken along the - arrow in FIG. 8, FIGS. 10 and 11 are sectional views showing the fourth embodiment, FIG. 12 is a sectional view showing the fifth embodiment, and FIG. 13 is a sectional view showing the sixth embodiment. Further, FIG. 14 is a plan view showing a conventional example, and FIG. 15 is a sectional view taken along the - line in FIG. 14. 10...Tool body, 11...Throwaway tip, 12...Tip seat, 14...Collection, 1
5...Elastic deformation part, 11a...Mounting hole, 11b...
... Enlarged part, 17a... Enlarged part, 17... Screw, 1
9,20...Collect.

Claims (1)

[Claims] 1 A mounting hole is formed in the throwaway tip,
Further, a tapered enlarged portion whose diameter increases toward the end is formed at the end of the mounting hole, and the throw-away tip can be freely attached to and removed from the tool body by inserting a screw into the mounting hole. In the throw-away cutting tool attached to the tool body, a collet having an elastic deformation portion is attached to the tool body with the elastic deformation portion protruding from the tip seat of the tool body, and the elastic deformation portion is free. In the state, the throwaway tip has an outer diameter smaller than the inner diameter of the mounting hole of the throwaway tip, and has a tapered shape that increases in diameter toward the end, and in the expanded state, the throwaway tip has an outer diameter smaller than the inner diameter of the mounting hole of the throwaway tip. The throw-away tip is configured to engage and come into contact with the enlarged portion of the mounting hole of the tool body, while the throw-away tip is arranged in the tip seat of the tool body.
The collet is fitted into the mounting hole and is seated, and at least one of the collet and the tool body is provided with an elastically deformable portion of the collet expanded by an enlarged portion of the head when the collet is screwed into the tool body. Throw-away cutting, characterized in that a screw for fixing the throw-away tip to the tool body is screwed in such a way that it can be tightened or loosened by engaging and abutting the enlarged part of the attachment hole of the throw-away tip. tool.