JPH0255163B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Field of Application] The present invention relates to a tool for drilling holes in difficult-to-cut materials. [Conventional technology] Conventional tools for drilling holes in difficult-to-cut materials (hardened stainless steel, die steel, high-speed steel, etc.) include:
Hard alloy is used for the cutting edge. [Problem to be solved by the invention] A normal torsion drill with cemented carbide has a chisel part (chisel part) at the end, and when drilling a hole, it does not perform any cutting action but is simply pushed in, so there is no resistance. was large and there was a problem of breakage. Furthermore, since the cutting edge has a helix angle and a rake angle, the cutting edge has an acute angle and often bites into the material during cutting, resulting in cutting damage. SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a tool for drilling difficult-to-cut materials, which prevents the cutting edge from biting into the tool during cutting. [Means for Solving the Problems] In order to achieve the above-mentioned object, the present invention provides a drill shank material with a front end having a parallelogram shape when viewed from the end, and a bisecting position of one diagonal line and the drill shank material. A plate-shaped cemented carbide alloy whose axes coincide with each other is provided, and the tip surface of this cemented carbide is made such that the matching point of the diagonal line becomes the apex and the diagonal line having the matching point is inclined toward both ends.
A conical angle of 110° to 180° is provided, and furthermore, there is no chisel part along the entire length of the diagonal at symmetrical positions with the above matching point on both sides of the diagonal as a boundary, and the helix angle and rake angle are 0°. It is constructed by providing a cutting edge with a sharp edge. [Operation] The cone angle is 110° to 180°, there is no chisel part, and the cutting edge has a helix angle of 0° and a rake angle of 0°, so there is no large resistance when cutting during drilling work.
The cutting blade will not dig in and break. [Embodiments] Hereinafter, embodiments of the present invention will be described based on the accompanying drawings. In the figure, 1 is a drill shank material. At the tip of the drill shank material 1, there is provided a plate-like superhard alloy 2 whose surface when viewed from the tip has a parallelogram shape and whose bisecting position on one side of the diagonal coincides with the axis of the drill shank material 1. ing. Further, a cone angle 3 of 110° to 180° is provided at the tip of the superhard alloy 2 so that the matching point of the diagonal lines becomes the apex and is inclined toward both ends of the diagonal line having the matching point. Further, at symmetrical positions with the matching points on both sides of the diagonal line as boundaries, there is no chisel portion along the entire length of the diagonal line having the matching points, and the cutting edge 4 has a helix angle and a rake angle of 0°. , 4 are provided. In addition, the tool A for drilling difficult-to-cut materials configured as described above is as follows:
In the case shown in the figure, the drill shank material 1 and the plate-shaped cemented carbide 2 are integrally provided using a super hard alloy. It's okay. In the figure, 5 is a first flank, and 5' is a second flank. [Effects] As described above, according to the tool for drilling difficult-to-cut materials according to the present invention, the cone angle is set to 110° to 180°, there is no chisel part, the helix angle is set to 0°, and the rake angle is set to 0. Since the cutting edge is provided with an angle of .degree., it is possible to solve the problem of the cutting edge biting in and breaking during cutting. The following is a cutting comparison table of the drilling tool (X) according to the present invention and the conventional drilling tool (Y) made of cemented carbide.

[Table] The experimental results show that the tool of the present invention has excellent durability for drilling holes in difficult-to-cut materials.

[Brief explanation of drawings]

The drawings show an embodiment of the tool according to the present invention, and FIG. 1 is a front view, FIG. 2 is a side view of the same, FIG. 3 is a bottom view of the same, and FIG. 4 is a perspective view. A...Drilling tool for difficult-to-cut materials, 1...Drill shank material, 2...Superhard alloy, 3...Conical angle, 4...Cutting edge.

Claims (1)

[Claims] 1 At the tip of the drill shank material 1, a plate-shaped superhard alloy 2 is provided, whose surface when viewed from the tip has a parallelogram shape, and the bisecting position of one of the diagonals coincides with the axis of the drill shank material 1, and A conical angle 3 of 110° to 180° is provided on the tip surface of this super hard alloy 2 so that the matching point of the diagonal lines becomes the apex and is inclined toward both ends of the diagonal line having the matching point, and For drilling difficult-to-cut materials, cutting blades 4, 4 without a chisel part and with a helix angle and rake angle of 0° are provided along the entire length of the diagonal line at symmetrical positions with the matching points on both sides as boundaries. tool.