JPH042741Y2 - - Google Patents

Description

[Detailed Description of the Invention] "Industrial Application Field" This invention relates to a throw-away cutting tool in which a tip seat facing the direction of rotation is provided at the tip of the tool body.

"Prior Art" Conventionally, indexable end mills 11 as shown in FIGS. 13 to 17 are known as indexable cutting tools. This indexable end mill 11 includes a cylindrical tool body 13. The tool main body 13 has a shank portion 15 provided at its rear portion and precisely ground and finished, and a head portion 17 formed in a cylindrical shape provided at its front portion.

The head 17 is provided with a tip pocket 19 that is open toward the front and radially outward. This tip pocket 19 has a tip pocket bottom surface 21 facing the rotation direction of the tool body 13 and a tip pocket 19 that faces the rotation direction of the tool body 13.
and a tip pocket side wall 23 facing in a direction opposite to the direction of rotation of the tip pocket. The head 17
The forward side of the tip pocket 19 in the rotational direction is
The rib portion 25 is formed so as to be spaced apart from the bottom surface 21 of the tip pocket toward the rear from the tip of the head.

A chip seat 27 is provided in the front half of the bottom surface 21 of the chip pocket. This chip za 27
A chip seat bottom surface 29 facing the rotational direction of the tool body 13 and located rearward in the rotational direction from the tip pocket bottom surface 21, and a first chip seat side wall (chip seat side wall) 31 facing forward of the tool body 13.
and a second chip seat side wall 33 facing outward in the radial direction of the tool body 13. The first and second chip seat side walls 31 and 33 have a contact surface 35 with which the side surface of the cutting blade chip fixed to the chip seat 27 comes into contact, and a contact surface 35 between the contact surface 35 and the chip seat bottom surface 29. A relief surface 37 is formed between the tip and the tip seat bottom surface 29, and a corner radius 39 is formed between the relief surface 37 and the tip seat bottom surface 29.

In such a chip seat 27, a cutting blade chip 41 is installed.
is installed. The cutting edge tip 41 is fixed by a clamp screw 47 with its tip bottom surface 43 in contact with the tip seat bottom surface 29 and its tip side surface 45 in contact with the abutting surface 35 . Then, the tool body 13 is rotated, and the cutting tip 41 cuts the workpiece.

"Problems to be Solved by the Invention" By the way, in the indexable end mill 11 described above, the intersection between the tip seat bottom surface 29 and the outer circumferential surface 49 of the head 17 intersects with the tip seat side wall 31. , Stress is most concentrated during cutting. However, as shown in FIG.
The angle α between the cutting edge tip 41 and the outer circumferential surface 49 is
Not only is it thick, but the cutting edge tip is usually 41 mm.
It is necessary to provide a positive rake angle in the circumferential direction, so it is made at an acute angle. Therefore, as shown in FIG. 17, a crack A is generated due to the notch effect at a portion where the tip seat bottom surface 29 and the outer circumferential surface 49 intersect with the tip seat side wall 31. There was a problem in that it was easy to cause defects in No. 13, and therefore, efficient and economical cutting was hindered.

Incidentally, in the case of the end mill 51 with a bottom blade shown in FIGS. 18 to 20, breakage occurred on the plane indicated by arrow B in the figures, and the tip side thereof was chipped.

``Means for solving the problem'' This invention was made to solve the above problem, and it is a part of the intersection between the outer peripheral surface of the tool body and the bottom surface of the chip seat near the side wall of the chip seat. To,
It is configured with a chamfered surface.

"Example" Hereinafter, an example of this invention will be described with reference to FIGS. 1 to 12. In addition, in these figures, the same reference numerals are given to the parts having the same configuration as those of the conventional example, and the explanation thereof will be omitted.

1 to 3 are diagrams showing a throw-away type end mill 61 according to the present invention. In this indexable end mill 61, a chamfered surface 63 is provided on the outer circumferential surface 49 of the head 17 at the intersection of the tip seat bottom surface 29 and the tip seat side wall 31. This chamfered surface 63 is a grooved surface extending in the tangential direction of the outer circumferential surface 49, and as shown in FIG.
It is formed to have an angle of 90° or more. and,
This chamfered surface 63 is formed such that a portion of the chamfered surface 63 that intersects with the intersection of the chip seat bottom surface 29 and the chip seat side wall 31 is the deepest part with respect to the outer circumferential surface 49.

In addition, in FIGS. 1 to 3, the cutting blade tip 41 attached to the tip seat 27 is omitted from illustration in order to make the area around the tip seat 27 easier to see.

As described above, in the case of this indexable end mill 61, a chamfered surface 63 is provided on the outer circumferential surface 49 at the intersection of the tip seat bottom surface 29 and the tip seat side wall 31, and the chamfered surface 63 is provided at the intersection of the tip seat bottom surface 29 and the Since the angle β formed with the chamfered surface 63 is 90° or more, it is possible to prevent the notch effect, and therefore, it is possible to prevent cracks from occurring in this portion and causing damage to the main body.

4 to 6 are diagrams showing a throw-away type end mill 71 which is another embodiment of the present invention. This indexable end mill 71
In the outer peripheral surface 49 of the head 17, a chamfered surface 73 consisting of a spherical recess is provided at the intersection of the chip seat bottom surface 29 and the chip seat side wall 31. As shown in FIG. 4, this chamfered surface 73 is formed so that it forms an obtuse angle with the tip seat bottom surface 29.

As described above, in this throw-away type end mill 71, a chamfered surface 73 is provided on the outer circumferential surface 49 at the intersection of the tip seat bottom surface 29 and the tip seat side wall 31, and the chamfered surface 73 is provided at the intersection of the tip seat bottom surface 29 and the Since the angle formed with the chamfered surface 73 is an obtuse angle, it is possible to prevent the notch effect similarly to the indexable end mill 61 described above, thereby preventing cracks from occurring in this part and causing damage to the main body. can do.

In addition, in FIGS. 4 to 6, the cutting blade tip 41 attached to the tip seat 27 is omitted in order to make the area around the tip seat 27 easier to see.

7 to 9 are diagrams showing an example in which the present invention is applied to a boring bar 81, in which reference numeral 83 indicates a chamfered surface.

10 to 12 are views showing an example in which the present invention is applied to a throw-away type drill 91, and the reference numeral 93 in the figures indicates a chamfered surface.

In addition, in the above embodiment, a concave curved surface is employed as the chamfered surface, but there is no need to limit it to this, and a convex curved surface or a straight plane may be used.

"Effect of the invention" As explained above, according to this invention, a chamfered surface is provided at the intersection of the outer peripheral surface of the tool body and the bottom surface of the chip seat near the side wall of the chip seat. It is possible to prevent cracks from occurring at the intersection between the bottom surface of the chip seat and the outer peripheral surface of the tool body and the side wall of the chip seat, thereby preventing damage to the tool body and improving efficiency and economy. The effect of being able to perform cutting is obtained.

[Brief explanation of the drawing]

1 to 3 are views showing one embodiment of the present invention, in which FIG. 1 is a sectional view taken along the line - in FIG. 2, FIG. 2 is a plan view thereof, and FIG. Its front view and FIGS. 4 to 6 are views showing other embodiments of the present invention, in which FIG. 4 is a sectional view taken along the line - in FIG. 5, and FIG. 5 is a plan view thereof. , FIG. 6 is a front view thereof, and FIGS. 7 to 9 are views showing other embodiments of the present invention, and FIG. 7 is a plan view thereof.
FIG. 8 is a front view thereof, FIG. 9 is a top view in the axial direction, and FIGS. 10 to 12 are views showing other embodiments of the present invention, and FIG. 10 is a plan view thereof;
FIG. 11 is a front view thereof, FIG. 12 is a view from the tip in the axial direction, and FIGS. 13 to 17 are views showing an example of a conventional indexable end mill, and FIG. 13 is a plan view thereof. FIG. 14 is a front view thereof, FIG. 15 is a view from the tip in the axial direction, FIG. 16 is a sectional view taken along the line - in FIG. 14, and FIG. 17 is an enlarged view of the arrowed part in FIG. 14. 1st
Figures 8 to 20 are views showing the damaged parts of another example of the conventional throw-away type end mill, in which Figure 18 is a plan view thereof, Figure 19 is a view from the tip in the axial direction, and Figure 20. is a front view of only the tip thereof. 13... Tool body, 27... Chip seat, 29...
...Chip seat bottom surface, 31...First chip seat side wall (chip seat side wall), 41...Cutting blade chip, 49...
Outer peripheral surface, 61... Throwaway end mill (throwaway cutting tool), 63... Chamfered surface, 71... Throwaway end mill (throwaway cutting tool), 73... Chamfered surface, 8
1... Boring bar (throw-away cutting tool), 83... Chamfered surface, 91... Throw-away drill (throw-away cutting tool), 93
... Chamfered surface.

Claims (1)

[Scope of utility model registration request] A tip seat bottom face facing the rotational direction of the tool body and intersecting the outer circumferential surface of the tool body, and a tip seat bottom face facing the forward direction of the tool body intersecting the outer circumference surface of the tool body, are provided at the tip of the cylindrical tool body. In a throw-away cutting tool in which a chip seat is provided with a chip seat side wall and a cutting edge tip is attached to the chip seat, the chip seat is located at the intersection of the outer peripheral surface of the tool body and the bottom surface of the chip seat. A throw-away cutting tool characterized by having a chamfered surface near the side wall.