JP2526635Y2 - Slow way type milling tool - Google Patents

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to an improvement of a throw-away type milling tool, and more specifically, to an improvement of a means for fixing a tip to a throw-away type end mill or a shank of a drill. It was done.

2. Description of the Related Art Conventionally, throw-away type end mills and drills have been disclosed in, for example, Japanese Utility Model Application Laid-Open No. 63-124412 and Japanese Utility Model Application Laid-Open No. 64-12720 or Japanese Utility Model Application Laid-Open No. 2-47115. The chip seat provided at the end is a flat surface, and the seat surface of the chip fixed to the chip seat is also formed in a flat shape, and is used by being screwed.

Further, as in the technique disclosed in Japanese Utility Model Laid-Open No. 2-114418, the tip seat of the shank and the seat surface of the tip are provided with straight recesses and projections in a direction of 90 ° or less with respect to the axis of the tool. Is formed, and the chip is fixed to the chip seat in a state where the concave portion and the convex portion are fitted.

[Problem to be Solved by the Invention] However, in the chip seat described above and the chip seat surface formed in a plane, when a cutting load is applied to the chip, the chip in the shank tip seat slightly moves. Significantly degrades the accuracy of the machined surface.

Further, the above-described shank tip seat and a linear recess and projection formed on the tip seat surface and fixed with the recess and projection fitted together are easy to machine. In addition, the processing cost is increased, and the one in which the concave groove is formed in the chip seating surface has a possibility that the chip strength is reduced and the chip is damaged.

[Purpose of the Invention] The present invention provides high-precision machining without slight movement of the insert even when a cutting load is applied to the insert at the insert seat of the shank, and has good machinability and low machining cost. It is another object of the present invention to provide a throw-away milling tool that does not reduce the strength of the insert.

[Means for Solving the Problems] The present invention has solved the above-mentioned problems by the following means.

That is, a tip seat having a standing wall is provided at the end of the shank, a boss having a notch is formed in the center of the tip seat, and the boss and the notch are formed on the seat surface of the chip fixed to the tip seat. A concave portion having a locking portion allowing fitting with the portion is provided, and at least the notch portion of the chip seat and the locking portion of the chip are brought into contact with or slightly separated from the chip seat. The chip is fixed.

According to the present invention, the tip in the tip seat of the shank is formed by the above-described means, and the tip seat, the seat surface of the tip, the two standing walls in the tip seat, and the two sides of the tip (flank face).
And the notch of the boss portion on the tip seat of the shank and the locking portion in the recess of the tip are restrained by four surfaces.

Therefore, the chip fixing force to the shank is greatly increased, so that even if a cutting load is applied to the chip during cutting, fine movement of the chip in the chip seat can be prevented, and a highly accurate machined surface can be obtained. It is to prevent.

[Example] Hereinafter, an example will be described based on the attached drawings.

The attached drawings show a ball end mill according to an embodiment of the present invention. FIG. 1 is an overall view, FIG. 2 is an enlarged front view of a main part of FIG. 1, and FIG. FIG. 4 shows the chip, FIG. 4 (a) is a front view, FIG.
FIG. 4 (b) is a rear view of FIG. 4 (a), and FIG. 4 (c) is a bottom view with a part of FIG. 4 (a) cut away.

In the figure, a tip 2 to be described later is attached to an end of a shank 1.
A chip seat 12 having standing walls 11a and 11b corresponding to the side surfaces (flank surfaces) is provided, and a screw hole 13 for screwing a chip fixing bolt is formed in the center of the chip seat.
A circular boss 14 is formed with circular arc-shaped cutouts 15a and 15b at predetermined intervals Fa and Fb with respect to the center 10a of the screw hole 13 and with the center 10b as a reference.

In the embodiment, the notch formed in the boss portion 14 is shown as a pair formed with a predetermined inclination angle toward the tool center 0.
The boss 14 may be formed with more than the number of places, and the shape of the notch may be elliptical or polygonal.

The tip 2 fixed to the tip seat 12 by the bolt 3 includes a pair of cutting edges 21a, 21b, 21c formed of an arc and a straight line composed of side faces 20a, 20b and rake faces 20c, 20d.
And a bolt hole 22 for inserting the bolt 3 in the center.
The chip seating surface 23 is provided with a recess 25 having locking portions 24a and 24b that can be inserted into the boss 14 having the cutouts 15a and 15b provided on the tip seat of the shank.

Then, insert 2 into the tip seat 12 of the shank
Is placed and the bolt 3 is tightened.
Means that the side surfaces 20a and 20b of the chip are standing walls 11a and 11b of the chip seat, and the locking portion 24a in the chip recess is the notch 15b and the chip seat of the chip seat. The chip is fixed to the chip seat with the surface 23 and the chip seat 12 pressed together.

[Effects of the Invention] As described above, in the present invention, the chip is fixed with the four sides constrained to the chip seat, so the fixing force is greatly increased and the chip is cut during cutting. Even if a load is applied, the chip is prevented from micro-moving, an extremely high machined surface is obtained, and breakage accompanying the micro-movement of the chip is greatly reduced.

[Brief description of the drawings]

FIG. 1 shows a ball end mill according to an embodiment of the present invention. FIG. 1 is an overall view, FIG. 2 is an enlarged front view of a main part of FIG. 1, and FIG. 3 is a view of FIG. FIG. 4 (a) is a front view, FIG. 4 (b) is a back side view of FIG. 4 (a), and FIG. 4 (c) is a side view of FIG. It is a bottom view etc. which fractured a part of figure (a). 1 ... Shank 10a ... Center of screw hole 10b ... Center of boss 11a, 11b ... Standing wall 12 ... Tip seat 14 ... Boss 15a, 15b ... Notch 2 ... Tip 21a, 21b ... Cutting blade 23: Tip seat surface 2a, 24b: Stop 25: Recess

Claims (1)

(57) [Scope of request for utility model registration] 1. A tip seat having an upright wall is provided at an end of a shank, a boss having a notch is formed at the center of the tip seat, and the boss is provided on a seat surface of a chip fixed to the tip seat. A concave portion having a locking portion that allows fitting between the chip seat and the notch portion, and at least the notch portion of the chip seat and the chip locking portion are in contact with or slightly separated from each other. A throw-away milling tool, characterized in that the insert is fixed to the cutting tool.