JPH0567413U - Drill blade - Google Patents

Abstract

(57) [Summary] [Purpose] Since the drill blade is subject to load on the blade edge and is prone to wear, a drill blade with a shape that does not concentrate the load on the shoulder portion of the blade edge is provided. [Structure] A drill blade 10 has a spiral blade 11 formed around a shaft, and a cutting edge 12 thereof is formed so as to be inclined downward from an axis center toward an outer peripheral direction, and the shoulder portion 1 of the cutting edge is formed.
The inclination angle θ2 in 3 was further inclined than the inclination angle θ1 of the cutting edge 12, and the shape was cut off.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to the structure of a conical or drill blade.

[0002]

[Prior Art]

 As shown in FIG. 3, a conventional drill blade has a spiral blade 21 formed around a shaft, and a cutting edge 22 thereof is inclined so as to descend from an axis center toward an outer peripheral direction. In such a conventional drill blade 20, the portion of the cutting edge 22 bites into an object such as a metal plate or the like to make a hole while cutting.

[0003]

[Problems to be solved by the device]

 In the conventional polishing of the cutting edge 22 of the drill blade 20, the cutting edge 22 has a planar shape because it is polished with a predetermined inclination angle with respect to the axial direction. However, since the outer peripheral surface of the spiral blade is formed into a cylindrical surface, the shoulder portion 23 of the blade tip is more loaded than other portions, and accidents such as chipping or abrasion and partial sharpness cause sharpness. There was a problem of getting worse.

Therefore, the present invention has been made for the purpose of providing a drill blade having a shape such that the load is not concentrated on only the shoulder portion of the cutting edge.

[0005]

[Means for Solving the Problems]

 In the present invention made in view of the above problems, in a drill blade in which a spiral blade is formed around a shaft and the blade edge is inclined downward from the axis toward the outer peripheral direction, Measures were taken to further incline the angle of inclination at the shoulder.

[0006]

[Action]

 According to the present invention having the above-described configuration, since the inclination angle of the shoulder portion of the cutting edge of the drill is further inclined than that of the other cutting edge portions, the load is not concentrated on the shoulder portion due to the rotation of the drill blade. .

[0007]

【Example】

 Hereinafter, a detailed description will be given based on an embodiment of the drill blade of the present invention. FIG. 1 is a perspective view of an essential part of the drill blade of the above embodiment, and FIG. 2 is a side view of the drill blade.

As shown in FIG. 1, the drill blade 10 has a spiral blade 11 formed around its axis, and its cutting edge 12 is formed so as to be inclined downward from the axis toward the outer peripheral direction. The inclination angle θ2 of the shoulder portion 13 of the cutting edge was further inclined as compared with the inclination angle θ1 of the cutting edge 12, and the shape was cut off.

Both shoulder portions of the cutting edge 12 may be ground into a cut-off shape.

According to the drill blade 10 having such a shape, since the inclination angle of the shoulder portion 13 of the blade tip is further inclined as compared with the portion of the other blade tip 12, the rotation of the drill blade concentrates only on the shoulder portion. Is not overloaded. Therefore, it is possible to prevent the shoulder portion 13 from being chipped and prevent partial wear.

As described above, according to the drill blade 10, it is possible to obtain an excellent sharpness and an excellent durability without wear loss.

It should be noted that the structure of the present invention is characterized in that the shoulder portion of the cutting edge is formed obliquely, and it is preferably applied to a cone for a steel plate or a drill blade. Of course, it can be applied to metals other than iron plates, hard materials, and other drill blades.

[0013]

[Effects of the Invention] According to the drill blade of the present invention, the inclination angle of the shoulder portion of the drill edge is further inclined as compared with the other blade edge portions. Therefore, it is possible to prevent stress from being concentrated, prevent the shoulder part from chipping, and prevent partial wear. Therefore, it is possible to obtain an excellent sharpness and also an excellent durability without wear defects.

[Brief description of drawings]

FIG. 1 is a perspective view of an essential part of a drill blade according to an embodiment of the present invention.

FIG. 2 is a side view of the drill blade.

FIG. 3 is a perspective view of a main part of a conventional drill blade.

[Explanation of symbols]

 10 Drill Blade 11 Spiral Blade 12 Blade Edge 13 Shoulder Part θ1, θ2 Inclination Angle

Claims (1)

[Scope of utility model registration request] 1. A drill blade in which a spiral blade is formed around an axis, and the blade edge is inclined downward from the axis toward the outer peripheral direction, the inclination angle of the shoulder portion of the blade edge is further inclined. A drill blade characterized by being made.