JPH04183512A - Throw-away type end mill - Google Patents

Abstract

PURPOSE:To enhance the clamp strength and to reduce defect of a chip by locating first and second cutting blade chips at the tip end of an end mill body in a counterclockwise twist relationship, and by providing an axial side wall on the chip seat of the first cutting blade chip. CONSTITUTION:A cutting chip discharge pocket 2 which is twisted clockwise in reference to a direction viewing the tip end thereof, is formed axially of an end mill body 1. Further, chip seats 4 are formed in this pocket 2 so that a plurality of cutting chips 3 are arranged at narrow intervals in the axial direction. Each of the chip seats 4 is provided thereon with first and second cutting blade chips 31, 32, or first to third cutting blade chips 31, 32, 33 in a counterclockwise twisting relationship. Further, the twisting is changed from the second cutting blade chip 32 or the third cutting blade chip 33 which is the final one in the counterclockwise direction.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an indexable end mill, and is particularly suitable for use with a long ladle cutting edge.

(Prior Art) Conventionally, this type of indexable end mill has been disclosed, for example, in Japanese Utility Model Application Laid-Open No. 61-78520. The end mill shown in this publication is provided with a right-handed chip discharge pocket in its r-tool body, and inside this chip discharge pocket, cutting blade tips that also have a right-handed twist are arranged at intervals in the axial direction. It is something that Furthermore, in order to cut the bottom surface of the cutting edge tip located at the tip of the tool body, consideration has been given to increasing the clamping force in the axial direction by driving a bottle or providing a key in the tip seat. .

(Problems to be Solved by the Invention) However, even with the cutting edge consideration given to the cutting edge tip, the clamping strength is weak, and under the recent trend toward high efficiency cutting, this has been a cause of tool breakage. In addition, with this type of end mill, chipping of the cutting edge or damage to the tool body due to biting of chips during cutting is likely to occur, and countermeasures have also been a problem.

(Means for Solving the Problems) The present invention has been made in view of the points mentioned in -F, and includes a chip evacuation pocket that is twisted to the right when viewed from the tip in the axial direction of the approximately cylindrical tool body. This is an improvement based on the premise of a throw-away type 1-inch mill, which is equipped with a chip seat so that multiple cutting blade chips are arranged with narrower spacing between them in the axial direction within this chip evacuation pocket. It is.

In other words, the chip seats are arranged so that the first and second cutting chips or the first to third cutting chips at the leading edge of each chip discharge pocket are arranged with a left-handed twist. This is what I did. Further, the second or third cutting blade tip, which is the final left-handed twist, is configured to be converted to right-handed twist.

(Function) Thumb-away type 1 tommill ii of the present invention, the first cutting edge at the leading edge of the tool body, the door and the second
Since the third cutting edge tip is arranged to be twisted to the left at least, the tip seat in the first cutting edge tip has a side wall in the axial direction of the tool body. In particular, the clamp rigidity in the axial direction can be improved.

Furthermore, in the indexable end mill of the present invention, the axial distance between the cutting blade tips is also small, so that the entrapment of chips is reduced.

(Example) In Figures 1 to 3, (1) is a cylindrical end mill body, and this body (1) usually has a plurality of chip evacuation pockets that are twisted to the right when viewed from the tip. (2
) is provided, and within this chip discharge pocket (2) is provided a chip seat (4) for receiving the cutting blade chip (3).

The cutting edge tip (3) is arranged at the fourth position on the rotation trajectory.
It is as shown in the figure, and its developed view is as shown in Fig. 5.

Therefore, the arrangement of the cutting blade tips (3) is narrow in the axial direction as shown in Fig. 5 and Fig. 6 which is a cross-sectional view. Placed. Regarding the arrangement in the torsional direction, the first cutting blade tip (3,) and the second cutting blade tip (32) at the leading edge are left-handed, and the second cutting blade tip (32) is twisted to the left. ) and after that, it becomes a right-handed twist. This is a consideration to increase the clamping strength in the axial direction by providing a side wall in the axial direction of the chip seat (4) in the first cutting edge tip (31), as seen in FIG. Therefore, the first cutting edge tip (3
, ) can sufficiently withstand the cutting force even if the bottom surface of the workpiece is cut.

Fig. 7 shows another modification, in which the first to third cutting blade tips +311 t: 32) +3.1 are left-handed twists, and the third cutting blade tip (3,) In the following, a right-handed twist will be constructed.

Furthermore, FIG. 8 shows another modification, in which the same shape is applied to the cutting tip (3),
No. 1] 24 (3.l (3+l) with the cutting start position in the axial direction set to the first position.

That is, in the indexable end mill shown in FIGS. 4 to 7, the cutting start position of the first cutting edge tip (3,) located at the leading edge is made equal for the first position in the axial direction, and One of the cutting blade tips (3,) is made slightly larger, and two types of cutting blade tips are applied.

(Effects of the Invention) As explained above, the present invention is configured to improve the twisting direction in the arrangement of the cutting blade tips (3) and to reduce the adjacent interval in the axial direction.

Therefore, the clamping strength is increased by the presence of the axial side wall in the chip seat (4) of the first cutting edge chip (3,) located at the leading edge of the tool body (11).
It also has the advantage of reducing damage to the cutting edge tip (3) due to biting of chips.

[Brief explanation of drawings]

Fig. 1 is a partial front view showing one embodiment of the throw 7-way type ecito mill of the present invention, Fig. 2 is a bottom view thereof, Fig. 3 is a partially side view of Fig. 2, and Fig. 4 is an explanatory diagram of the rotation locus of the cutting blade tip, Figure 5 is a developed view when the cutting blade tip is placed against the end mill body, and Figure 6 is an explanation of the installation state of the cutting blade tip. 7M and 8 are exploded views showing modified examples when the cutting tip is arranged with respect to the end mill body. (1)... End mill body (21... Chip discharge pocket (3)... Cutting blade tip (31)... First cutting blade tip (32)... Second cutting blade Tip (3,)...Third cutting edge tip (4)...Chip seat Patent applicant Toshiba Tungaloy Corporation

Claims (1)

[Claims] A chip discharge pocket (2) is provided in the axial direction of the end mill body (1) having a substantially cylindrical shape, and is twisted to the right when viewed from the tip. , an indexable end mill in which a chip seat (4) is provided so that a plurality of cutting blade chips (3) are arranged with narrow adjacent intervals in the axial direction; The first and second cutting tips (3_
1) (3_2) or the first to third cutting blade tips (3_1) (3_2) (3_3) are arranged in a left-handed twist, and the second cutting edge tip (3_2) is the last left-handed twist. 3_2) or the third cutting edge tip (3_2)
3) is an indexable end mill characterized by being converted to a right-hand helix.