JPH0212004Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention mainly relates to a throw-away tip that is incorporated into a large-diameter throw-away drill.

(Prior Art) Conventionally, as this type of throw-away chip, for example, Japanese Patent Application Laid-Open No. 54-53387,
-There are some that can be seen in Publication No. 39291, etc. The former is
A plurality of recesses are provided to cut out the edge of the cutting edge, and the latter has chip breaker grooves formed in parallel along the edge of the cutting edge.

(Problems to be Solved by the Invention) However, in these publications, the flow direction of chips is perpendicular to the edge of the cutting edge. However, with this type of throw-away tip, there are cases where it is necessary to cut across the entire cutting edge. In such a case, the generated chips may become entangled, resulting in a problem that appropriate chip disposal cannot be achieved. Therefore, the rake face solves the above problems so that effective chip disposal can be performed even when cutting is performed over the entire cutting edge.

(Means for Solving the Problems) The present invention was developed in view of the above-mentioned points, and the cutting edge ridge and the chip breaker groove adopt a substantially sinusoidal waveform shape, and also prevent the flow of chips. Regarding the direction, the direction of the waveform shape is set so that the chips are not bound to each other.

(Function) Since the throw-away tip of the present invention has a substantially sinusoidal cutting edge, the chips generated are
It flows out in a wavy shape along the edge of the cutting edge. Since the chips are forcibly curled at the boundary between the central land portions, a shearing force is applied to the chips, and the chips are broken into a predetermined length.

Further, the outflow direction of the chips is parallel to the bisector of the apex angle B, and the constraint in the orthogonal direction is small. As a result, a reduction in chip resistance and an increase in the chip ratio are observed, resulting in an effect of expanding the chip disposal range.

(Example) Hereinafter, an example of the throw-away chip of the present invention will be described with reference to the drawings.

In FIGS. 1 to 3, reference numeral 1 denotes a throw-away chip in the form of a hexagonal plate with equal sides, and a center mounting hole 2 is formed in the center of the throw-away chip. This throw-away chip 1 has a relationship of apex angle A < apex angle B, and apex angles A and B are located alternately adjacent to each other. For example, in the case shown, the apex angle is
It constitutes an acute angle of 60 degrees or more, and the apex angle B constitutes an obtuse angle, examples of which include A = 80 degrees and B = 160 degrees.

This throw-away tip 1 forms a symmetrical cutting edge 3 on both sides with the apex angle B in the center. Furthermore, a chip breaker groove 4 and a central land portion 5 are formed on the rake face side forming the cutting edge 3.

The cutting edge 3 and the chip breaker groove 4 exhibit a substantially sinusoidal waveform shape as clearly shown in FIG. 2, and thereby produce chips having a waveform cross section. .

The chip breaker groove 4 has a substantially sinusoidal wavy shape in a direction perpendicular to the bisector of the apex angle B. This is different from the conventional one which is perpendicular to the cutting edge 3.

That is, the waveform shape of the throwaway tip 1 of the present invention forms a peak on the bisector of the apex angle B, and at the nose portion 6 near both ends thereof, it changes from a flat surface to a trough toward the center. It continues to the top on the bisector through the top and valley located in the middle.

Further, the cutting edge 3 has a rake angle θ (for example, θ
= 5°), and is located at a somewhat lower level (for example, lower amount δ = 0.1 mm) than the central land portion 5, and accordingly, the tip breaker groove 4 has a boundary with the central land portion 5. It is cut up in parts. As a result, the generated chips are forcibly curled at this boundary portion, so that shearing force is applied to the chips and the chips are broken into a predetermined length.

FIG. 4 shows a drilling tool to which this throw-away tip 1 is applied. In Figure 4, 11
is a rod-shaped tool body, and the central part is
A pilot drill 12 is attached, and a cartridge 14 with a throw-away tip 1 screwed into each flute groove 13 on its outer periphery is installed.
is attached with a tightening screw 15. In this case, a pair of injection holes 17 are drilled in the helical groove 16 of the pilot drill 12, and a chip pocket 18 is formed along the helical groove 16.
An injection hole 19 is also bored in the hole. The injection hole 19 is provided with a plug 20 having three branch openings, for example, in order to prevent the intrusion of chips generated from a workpiece (not shown).

In this embodiment, the present invention is applied to a drilling tool equipped with a pilot drill 12, but it goes without saying that the invention can also be applied to a trepanning tool, a parting tool, a grooving tool, and the like.

(Effects of the invention) As explained above, the present invention forms the cutting edge 3 and the chip breaker groove 4 in a waveform shape of a substantially sinusoidal curve, and takes into consideration the flow direction of the generated chips. Therefore, it has the following effects.

First, the chips must be properly disposed of. This is because the wavy shape generates chips and breaks them to a predetermined length, making it easier to dispose of the chips. Further, since the outflow direction of the chips is parallel to the bisector of the apex angle B, the chips are no longer bound to each other.

Second, chip resistance is reduced and cutting efficiency is improved. This is because the above-mentioned chip disposal is improved, and since the chips are not bound to each other, effective cutting work can be performed.

[Brief explanation of the drawing]

FIG. 1 is a front view showing one embodiment of the throw-away tip of the present invention, FIG. 2 is a bottom view thereof, and FIG.
The figure is a sectional view taken along the - line in FIG. 1, and FIG. 4 is a partial perspective view showing the state in which it is assembled into a drilling tool. 1... Throwaway tip, 3... Cutting edge ridge,
4... Chip breaker groove, 5... Central land area, 6...
...Nose part.

Claims (1)

[Claims for Utility Model Registration] Equilateral hexagonal plate-like plates with the relationship of apex angle A < apex angle B are arranged alternately adjacent to each other, and the sides constituting the apex angle B are shallow. A V-shaped cutting edge 3 is formed, and this cutting edge 3
There are chip breaker grooves 4 around the entire circumference of the rake face side.
In the throw-away chip in which the central land portion 5 remains due to the formation of It has a wavy shape, and forms a peak on the bisector, and at the nose portion 6 near both ends thereof, the plane becomes a trough toward the center, and this wavy shape forms a peak located in the middle, The cutting edge 3 is connected to the top on the bisector through the valley, and the cutting edge 3 is located at a somewhat lower level than the central land 5, and is formed along with the formation of the chip breaker groove 4. A throw-away tip characterized by exhibiting a waveform shape.