JPH0314249Y2 - - Google Patents

Description

[Detailed description of the invention] (Field of industrial application) This invention relates to an end mill made of hard material that is based on epoxy resin and contains quartz sand as an internal component, and is suitable for manufacturing, modifying, and processing non-metallic molds, etc. .

(Prior art) Recently, some molds are changing from iron-based metals to non-metallic molds, and the materials used are based on epoxy resin and contain quartz sand as an internal component. Summer. For manufacturing, modifying, and processing this type of mold, an end mill having a normal structure in which a shank 1 has a twisted cutting edge 3 formed at the tip, as shown in FIG. 3, is used.

(Problem that the invention aims to solve) However, since these ordinary end mills are mainly intended for processing ferrous metals, non-ferrous metals, and special alloys, they are based on the above-mentioned epoxy resin and contain quartz as an internal component. Materials containing sand (hereinafter referred to as "special materials") cannot withstand long-term use. This is clear from various cutting test data. This fact indicates that even end mills coated with a coating to improve wear resistance or made of carbide material similarly wear out quickly and cannot withstand long-term use.

(Means for solving the problem) This invention is an end mill made of a hard material, in which the rake angle of the cutting edge is zero or negative, and the land has no counter-relief surface, and is suitable for cutting special materials. This is to prevent premature wear.

(Embodiment) Next, an embodiment of the end mill of this invention will be described with reference to FIG. 1. It is made of a hard material and has a cylindrical shank 1 at one end and four rounded grooves 21 at the other end. A cutting edge 31 is formed. At the tip, a bottom blade 4 is formed by intersecting rounded grooves 31 at the center O, as shown in FIG. Since the land 5 is not provided with the second relief surface 6 of the conventional product shown in FIG. 3, the width of the land on the outer periphery is increased. Furthermore, the rake angle α of the rake angle 7 of the cutting edge 31 is the first
As is clear from Figure 2, it is negative.

In the embodiment shown in FIG. 2, the groove 21 is U-shaped, and four grooves are bored in a straight line along the axis, and the rake angle α of the cutting edge 31 is negative as in FIG. It's summery. Similarly, the grooves 21 intersect at the center O at the tip to form the bottom edge 4.

The hard material for the end mill is cemented carbide, such as JIS K05~10, or cermet.
Use a wear-resistant tool grade such as CBN. Alternatively, those coated with a hard material such as TiC, TiN.Al ₂ O ₃ can be used. In addition, the number of grooves was 4 in the example, but depending on the material,
Of course, an appropriate value such as 3 or 5 can be selected.

(Function) The end mill according to this invention produced relatively good results when cutting was performed at a relatively low speed because the special material was hard and lacked toughness. By the way, when cutting with the end mill related to this invention at a cutting speed of 10 m/min
When cutting 12.35mm, the wear on the blade side is 0.15mm,
The outer diameter was 0.005 mm, which was fully satisfactory.

(Effects) This design has a zero or negative rake surface on the cutting edge as mentioned above, and does not form a second relief surface on the land, so it is special because it can sufficiently withstand abrasion phenomena. Even if the material is cut over a long period of time, no wear will occur. Furthermore, since cutting edges 31 are formed on both sides of the land, even if one cutting edge wears out, the other cutting edge on the rubbing side is not worn out, so by rotating the land in the opposite direction, cutting can be done with the other cutting edge. can do. Also, groove 2
No. 1 has many advantages, such as the fact that it does not wear out, so a cutting edge can be easily formed by simply grinding the outer periphery.

[Brief explanation of the drawing]

Fig. 1A is a side view of the embodiment of this invention, Fig. 1B is a front view of Fig. 2A, Fig. 2A is a side view of another embodiment, Fig. 2B is a front view of Fig. 3A, The figure is a side view of a conventional product, and the figure (b) is a front view of the same figure (a). 31... Cutting edge, 5... Land, 6... Second counter flank, α... Rake angle.

Claims (1)

[Claims for Utility Model Registration] (1) An end mill made of a hard material in which the rake angle of the cutting edge is zero or negative, and the land does not have a second relief surface. (2) The hard material end mill according to claim 1, wherein the rake angle is formed by a rounded groove. (3) The hard material end mill according to claim 1, wherein the rake angle is formed by a U-shaped groove. (4) The hard material end mill according to claim 1, wherein the cutting blades are formed on both side edges of the land.