JPS59196107A - Throw-away tip - Google Patents

Abstract

PURPOSE:To efficiently discharge chips, by finely breaking the chips to be separated in the width direction through step differences provided in the edge point part of a throw away tip. CONSTITUTION:A throw away tip 20 provides edge point parts 22a, 22b, 22c in its three-side part in the periphery of the main unit 21 of the tip, forming step differenced parts 23a, 23b, 23c for use as a chip breaker oppositely facing to each edge point parts 22a-22c. Further each edge point part 22a, 22b, 22c provides step differences 25a, 25b in the direction of thickness of the tip main unit 21, forming chip separators, that is, step differenced parts 26a, 26b in the cutting direction for finely breaking a chip to be separated in its width direction.

Description

[Detailed Description of the Invention] (Field of Application and Object of the Invention) This invention relates to a cutting blade for drilling deep holes in metal workpieces, particularly a so-called so-called cutting blade that is replaceably attached to a drill. Regarding throw-away tips.

(Prior Art) FIGS. 1 and 2 show a state in which a throw-away tip 1 (hereinafter referred to as a tip) of this kind of conventional structure is attached to a rod 2 of a drill. FIG. 3 shows this chip 1 and its mounting base 3. Generally, this type of chip 1 includes a chip body 4
The periphery of the main body is formed into a polygonal shape, as shown in the figure, it is an equilateral triangle in the front, and more specifically, each side of the triangle is slightly chevron-shaped.Of course, this may be a straight side, but the cutting edge 5a of each side .

5b and 5c, and is additionally formed on the front side of the chip body 4 (as will be explained later, a stepped portion 6 for a chip breaker is formed protrudingly. Note that this chip breaker 6 is not shown in the figure). Although the chip breaker is formed integrally with the chip body 4, a separate metal piece for the chip breaker may be attached and fixed to the chip body 4, which is a well-known and commonly used technique.

As shown in FIG. 1, this tip 1 is attached to the tip of the drill head 2 at two or more locations near the center and outside of the head 2, with one of the cutting edges 58 to 5C slightly protruding. A tool shank (not shown) is attached to the attachment part 2a, and a guide butt 2b is fixed to the side surface of the head 2 by screws 2C, and a deep hole is cut by rotation of these screws. Then, the cut chips and the cutting oil that have finished their work are discharged from the hollow part 2d of the drill head 2 to the outside through the hollow part of the tool shank.

When attaching the tip 1 to the trill head 2, as shown in FIG. 5, a concave part 7a for attaching the tip knob 1 may be provided at the throat/throat, and the tip knob 1 may be directly attached to this. Generally, in order to facilitate replacement, the mounting base 3 is provided with a recess 7 that matches the shape of the chip knob 1, as shown in FIG.
This is fixed to the mounting base 3, and this is fixed as a cartridge to the mounting recess 2e of the drill head 2 with screws 9 (see Fig. 1, Fig. 2, and especially Fig. 4). . If the cutting edge 5a of the tip 1 is worn out due to use, remove the mounting base 3 from the drill/nod 2, remove the tip 1 screwed to the mounting base 3, and insert a new cutting edge 5b or the other side. 5C is placed accurately at the cutting edge and screwed again, and this is screwed to the drill head 2 via the mounting base 3. Therefore, when the tip main body 4 has three cutting edges 5a, 5b, and 5c on its periphery as shown in the figure, it can be replaced with new cutting edges at least three times.

4 and 5 show a state in which a workpiece W is cut by this tip 1. FIG. Chips W1 generated by cutting by the cutting edge portion 5a of the tip 1 are as follows.

While hitting the stepped portion 6 protruding from the front of the main body 4 and being curved in an abbreviated shape, it is crushed at the curved portion P, as shown in FIG.
2 and is sent rearward from the hollow part 2d of the drill head 2 and discharged. Since the stepped portion 6 crushes the cutting waste W1 in the process of cutting, the stepped portion 6 is called a chip breaker. The reason why the cutting waste W1 in the middle of cutting is divided into thin pieces in this way is to prevent it from smoothly passing through the narrow hollow part 2d of the drill head 2 and the hollow part of the tool shank connected to this and causing clogging. In order to smoothly discharge the cutting waste, it is preferable that the cutting waste is divided as finely as possible.

Therefore, the cutting waste W1 has a small width β1 in the cutting waste generation direction.
However, in the direction perpendicular to this, it naturally becomes cutting chips with a width of 12, which corresponds to the width of the cutting edge of the cutting edge portion 5a, and if this width / 2 can be separated into approximately 2 pieces, the above-mentioned clogging will occur. This is preferable because it reduces the number of times. For this purpose, for example, as shown in FIG. 7, a deep hole cutting device which is relatively similar to the present invention, although it belongs to a different technical field,
That is, in the case of a cutting blade 11 that is integrally fixed to the drill head 10 by brazing or the like and cannot be replaced, a stepped part 12 in the cutting direction is provided on the cutting edge part 11a (this is called a chip separator). At step part 2, the width of the cutting waste during cutting is divided into two, and the width is narrow and the dark blue width is also cut into small pieces by the chip breaker and smoothly discharged.

However, in this type of replaceable tip 1, which is the technical field of the present invention, each of the cutting edge portions 5a to 5c of the tip 1 is always attached to the mounting base accurately and without wobbling in any exchange mode as described above. For this purpose, the outer circumferential surface of the chip body 4, which is generally referred to as the restraining surface 13 (see FIG. 3,
4 and 5), this restraining surface 13 must be seated accurately on the inner circumferential surface 14 of the recessed portion 7 or 7a. If a step is provided on the restraint surface 13, the chip l cannot be stably restrained in the recesses 7, 7a, and for this reason, a chip breaker cannot be provided in the conventional chip of this type. However, it was considered that chip separators could not be provided.

(Objective of the Invention) The present invention provides this type of thrower with a part that plays the same role as a chip separator without affecting the above-mentioned restraint surface in any way, thereby dividing cutting chips into finer pieces. The purpose is to make it possible.

(Structure of the Invention) In order to achieve the above-mentioned object, the first aspect of the present invention is to adopt a configuration in which an indexable tip having a cutting edge portion on the periphery is characterized in that the cutting edge portion is provided with a step in the thickness direction. It is something to do.

Second, in the same indexable tip that has a cutting edge on the periphery, a step in the thickness direction is provided at the cutting edge, and a kerf is provided in the restraining surface for positioning the 1000-knob, which is continuous with the step and extends in the thickness direction. It adopts a configuration characterized by the following.

Embodiment FIGS. 8 to 10 show an embodiment of the first invention. The indexable tip 20 shown in the embodiment includes a tip body 21 having a substantially equilateral triangular shape from the front, and a peripheral edge of the tip body 21. A cutting edge portion 22a provided on three sides of the blade.

22b, 22c, and chip breaker step portions 23a, 23b, which are formed in a flat front center portion of the chip body 21 to face each of the cutting edge portions 22a to 22c.
23c, and a mounting hole 24 for screw fixing, and in particular each cutting edge portion 22a, 22b, 22
c, there are steps 25a, 25 in the thickness direction of the chip body 21.
b. That is, Fig. 8,
In particular, as shown in FIG. 9, the cutting edge portion 22a is divided into three equal parts, and the central side thereof is formed into a tapered shape that gradually becomes thinner from the maximum thickness point a to the minimum thickness point d of the tip body 21. A tapered cutting edge piece 22a1 is formed, and the straight cutting edge piece 22a2 extends from the -blade side to the minimum thickness point to the same thickness, and the other side extends from the maximum thickness point a to the minimum thickness. Partial Taber cutting edge piece 2 consisting of a part that extends to the thick point and a part that extends to the same thickness from the minimum thickness point.
2a3, each cutting edge piece 22a1
．． 22a2. At the boundary of 22as, there is a step 2 in the thickness direction.
5a and 25b are provided.

To explain in more detail, as shown in FIG. 9C, if the depth of the step 25a provided in the thickness direction of the cutting edge portion 22a is X, and the relief angle of the cutting edge portion is α, then Xx tan α-3
As shown in FIG. 9d, the stepped portion 26a with a depth of
It appears in the cutting direction of 2a, and this serves as a chip separator. That is, as shown in FIG. 9a, stepped portions 26a, 26b in the cutting direction are formed on the respective cutting edge portions 22a, 22b, '22C. Note that depending on the type of chi/knob, the chip itself may or may not have the above-mentioned relief angle, but as shown in Figure 5, when it is attached to the drill/nod 2, It is designed to be installed at a slight inclination so as to provide the required relief angle α°, and therefore, by installing this type of chi knob to the drill head, the above-mentioned chip separation step portions 26a and 26b appear. It turns out.

Moreover, the cutting edge portions 22 a , 22 b , 22 on each side
Even if steps 25a and 25b are provided in the thickness direction in c.
As shown in the figure, each restraint surface 2 which is the outer peripheral surface of the chip body 21
As for chips 7a, 27b, and 27C, there are no uneven steps, so the chips 20 are placed in the chip shown in FIG.
The knob can be seated stably and accurately in the concave portion 7 of the knob mount 3.

FIG. 10 shows the state of cutting waste formation in this embodiment, in which cutting waste W! is generated by cutting with the cutting edge portion 22a.
As in the conventional case, the chip hits the step 23a for the chi-knob breaker and is crushed at the part indicated by P in the figure, and in this embodiment, the cutting chips with the width corresponding to the width of the cutting edge 22a are crushed at the cutting edge. The small piece Ws is separated at the steps 26a and 26b in the cutting direction formed by the steps 25a and 25b of 22a, divided into thirds in the width direction, and crushed into thin pieces in both width and length.

W4. It becomes Ws and is discharged.

Figures 11a and 11b show an embodiment of the second invention, and the general structure of the throw-away tip 28 in this embodiment is the same as that of the first invention, with the same reference numerals as in the previous embodiment. However, the cutting edge portions 22a, 22
Continuing from each step 25a, 25b provided in b, 22c, each restraint surface 29a, 29b,
29 c & kerf grooves 30a, 30b extending in the thickness direction
It is characterized by having the following. This kerf 30a.

By providing the groove 30b, each step 25a, 25b4 can be made deeper by the depth S of the step 26a plus the depth t of the kerf 30, as shown in FIG. The restraining surfaces 29a, 29b, and 29c have flat surfaces over almost the entire area, and uneven steps do not occur.

12 to 13 a and 13 b show an indexable tip 31 according to another embodiment of the first invention, and in the embodiment shown in FIGS. 8 to 9, the cutting edge portion 22a is A step 25a in the thickness direction is provided in the blade edge portion 22a by forming a tapered or straight thin portion in the thickness direction over the entire area, but in this embodiment, each blade edge portion 22a , 2
Parts 32a and 32b of 2b and 22c are connected to a restraining surface (
Steps 33a, 33b in the thickness direction are provided at the cutting edge portions 22a, 22b, 22c by cutting in a substantially V-shape from the flank surface to the rake surface.
, b, the stepped portions 34a, 34b in the cutting direction corresponding to the clearance angle α of the cutting edge portion are formed on each of the cutting edge portions 22a, 22.
b, 22c.

FIG. 14 does not show the indexable tip 35 of another embodiment in the second invention, and each step 33a provided on the cutting edge portions 22a, 22b, 22c of the embodiment shown in FIG. , 33b, and further each restraint surface 35a, 36b.

It is characterized in that grooves 37a and 37b extending in the thickness direction are provided in 36C, respectively. This kerf 37
a.

By providing 37b, each cutting edge portion 22a, 2
2b and 22c, the step in the cutting direction has a large step, so even if the feed rate becomes high, the cutting waste is more reliably divided at this step.

(Effects of the Invention) According to the present invention, cutting waste can be finely divided (separated) in the width direction of the indexable tip, so that the efficiency of discharging cutting waste can be significantly improved.

Also, according to the second invention, by providing a cutting groove on the restraining surface of the indexable insert that is continuous with the separation step at the cutting edge, cutting chips can be more reliably distributed in the width direction even when the cutting speed is high. It can be divided into small pieces.

[Brief explanation of drawings]

Figures 1 to 7 show conventional examples, of which the first
The figure is a front view showing how the symmetrical indexable tip of the present invention is attached to the trill head, and Figure 2 is a plan view of the same.
Fig. 3 is an exploded perspective view showing an example of the installed state of the throw-away tip, Figs. 4 and 5 are longitudinal sectional views of main parts showing the cutting state, and Fig. 6 is an enlarged view showing the state of generation of cutting waste. 7 is a front view showing a state in which a cutting blade is attached to a drill head in a field that is relatively similar to, but different from, the present invention. Figures 8 to 10 show the first
FIG. 8 is an enlarged perspective view, FIG. 9 a is a front view, FIG. 9 is a plan view, and FIG. 9 C is an enlarged plan view of the same main part. FIG. 9d is an enlarged front view of the same essential part, and FIG. 10 is an enlarged view showing the state of generation of cutting chips. FIG. 11a is an enlarged perspective view showing an embodiment of the second invention;
FIG. 11 is an enlarged front view of the same essential parts, FIG. 12 is an enlarged perspective view showing another embodiment of the first invention, FIG. 13a is a front view of the same, FIG. FIG. 14 is an enlarged perspective view showing another embodiment of the second invention. 20.28.3L35... Throwaway tip, 2
2a. 22b, 22c=-blade tip, 25a, 25b,
33a, 33b, one step difference, 30a, 30b, 37a
, 37b-kerf. Fig. 4 Fig. 5 Fig. 6 Fig. 7 One Fig. 11 a @11 Fig. 12 Fig. 1 Fig. 13 a Fig. 13 Fig. 14 Fig. 5 ZC

Claims (2)

[Claims] (1) An indexable tip having a cutting edge on the periphery, characterized in that the cutting edge is provided with a step in the thickness direction. (2) An indexable insert having a cutting edge on the periphery, characterized in that the cutting edge is provided with a step in the thickness direction, and the insert positioning restraining surface is provided with a kerf that is continuous with the step and extends in the thickness direction. Throwaway tip.