JPH0318084Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a throw-away tip that can widen the chip disposal range.

2. Description of the Related Art Conventionally, the one shown in FIG. 1 has been known as a throw-away tip that has a high chip processing ability for separating chips. This throw-away tip 1 has a peripheral edge of the rake face 11 along the cutting edge 12 as an inclined surface 11a that gradually descends from the cutting edge 12 side toward the inside.
The inner part of the flat surface 11b is defined as the flat surface 11b.
A convex portion 13 is formed in the vicinity of the nose portion 12a of the cutting blade 12 at the peripheral edge of the cutting blade 1b.

Throwaway tip 1 configured in this way
When cutting is performed with the nose portion 12a under cutting conditions of low feed and low depth of cut, thin and flexible chips are generated by the nose portion 12a. The chips extend along the inclined surface 11a and collide with the lower end of the convex portion 13, where they are sharply curled and divided. On the other hand, when chip machining is performed under cutting conditions of high feed and high depth of cut, the nose part 1
2a produces thick and hard chips. The chips leave the inclined surface 11a at a midpoint. Then, it collides with the top of the convex portion 13 while sliding thereon, and is gently curled with a large radius of curvature. At this time, since the chips are thick and hard, even if the curl radius is large, a large amount of stress is generated inside the chips, and the chips are divided by this internal stress. Moreover, since the chips slide and collide with the top of the convex part 13, the chips collide with the convex part 13.
There is no possibility of jamming between the cutting edge 12 and the cutting edge 12. Therefore, according to the throw-away tip 1, chips can be separated without causing chip clogging in a range of chip conditions from low feed and low depth of cut to high feed and high depth of cut. (Hereinafter, the range of such chip conditions will be referred to as the chip processing range.) By the way, the throwaway tip 1 as described above can be used for chip processing under chip conditions where the feed rate and depth of cut are particularly small, such as in finishing machining. This produces thinner and more flexible chips. Therefore, in such a case, the curl radius of the chips must be made smaller in order to reliably separate the chips, and for this purpose, the convex portion 13
It is necessary to bring this close to the nose portion 12a.

However, when the convex portion 13 is brought closer to the nose portion 12a, thick and hard chips, which are produced in the case of high feed and high depth of cut, collide with the lower end of the convex portion 13 and are rapidly curled. At this time, the chips are subjected to a large amount of frictional resistance. For this reason, the smooth discharge of chips is hindered, and the
and the convex portion 13. Further, the large impact force generated when thick and hard chips are suddenly curled causes the throw-away tip 1 to vibrate, causing problems such as chipping of the cutting edge 12 and deterioration of the finished surface. Therefore, although the throw-away tip 1 can widen the chip processing range compared to conventional throw-away tips, it can also be used for processing ranging from low feed and low depth of cut such as finishing machining to high feed and high depth of cut. It is not possible to dispose of the chips within that range.

This idea was created in consideration of the above circumstances, and while preventing the above problems from occurring during high feeds and high depths of cut, it also covers the range of low feeds and low depths of cut such as finishing machining. It is an object of the present invention to provide a throw-away tip that can widen the chip disposal range.

The feature of this device is that the part between the rake face with a cutting edge formed on the periphery and the cutting edge protrudes from the rake face and is lower in height than the convex part, and extends from the convex part to the cutting edge side. The point is that a protrusion is formed that extends toward the opposite side and has an upright wall portion formed on the cutting edge side from the top toward the rake face side.

An embodiment of this invention will be described below with reference to FIG. Fig. 2 shows the throw-away chip according to this invention, Fig. A is a plan view thereof, Fig. B is an enlarged cross-sectional view of Fig. A in the direction of X-X arrows, and Fig. C is an enlarged view of Fig. A in the direction of Y-Y arrows. FIG.

As shown in these figures, also in this throw-away tip 2, the peripheral edge portion of the rake face 21, on which the cutting edge 22 is formed, extends inward from the cutting edge 22 side. The slope surface 11a gradually descends, and the rake surface 2
1 is a flat surface 21b, and a convex portion 23 having a curved top is formed near the nose portion 22a of the flat surface 21b. This configuration is similar to the conventional throw-away chip described above.

However, this throw-away tip 2 is not only configured as described above, but also has a convex portion protruding from the rake face 21 and a portion between the convex portion 23 of the rake face 21 and the nose portion 22a. A protrusion 24 is formed extending from 23 toward the nose portion 22a. The height of this protrusion 24 is set lower than the height of the convex portion 23.

An upright wall portion 24a is formed on the cutting edge 22 side of the protrusion 24 from the top of the protrusion 24 toward the inclined surface 21a of the rake face 21. Note that, when the height of the convex portion 23 is H ₁ and the height of the protrusion 24 is H ₂ , it is desirable that H ₂ is 1/10H ₁ to 8/10H ₁ .

Therefore, the nose portion 22a of the throwaway tip 2 configured as described above allows for low feed,
When a low depth of cut cutting process is performed, the chips collide with the standing wall 24a at the tip of the protrusion 24 and are curled.
Since a is closer to the nose portion 22a than the convex portion 23, the chips are curled with a smaller radius than when only the convex portion 23 is formed. Therefore, cutting can be divided even when the feed amount and depth of cut are particularly small, such as in finish cutting.

On the other hand, when high-feed, high-cut chip machining is performed, the chips first collide with the vertical wall portion 24a at the tip of the protrusion 24 in this case as well. However, in this case, since the height of the protrusion 24 is lower than the height of the protrusion 23, the chips slide over the protrusion 24. Therefore, chips do not get stuck between the protrusion 24 and the nose portion 22a.
In addition, since the chips slide over the protrusion 24, no large impact force is applied to the chips, and the chip itself can be prevented from vibrating. Deterioration of the surface can be prevented. Note that, after climbing over the protrusion 24, the chips collide with the curved top of the protrusion 23, and are gently curled and separated by the cooperation of the protrusion 24 and the protrusion 23. At this time, since the contact area between the chips and the curved convex portion 23 is small,
Frictional resistance is low, so cutting resistance does not increase. Moreover, even in high feed and high depth of cut cutting in which the cutting edge part that is spaced apart from the nose part 22a is used, after the chips generated by the cutting edge 22 pass through the rake face 21, the convex portion 2 protrudes from the cutting edge 22a.
Since the chips are reliably curled and separated by the tops of the chips, it is possible to greatly expand the range of chip disposal.

Next, another embodiment of this invention will be described. Note that explanations of parts similar to those of the above embodiments will be omitted, and only the characteristic points of each embodiment will be described below.

The throwaway tip 3 shown in FIG.
The height of the protrusion 4 is gradually lowered from the convex part 33 toward the nose part 32a, and the protrusion 34 has a high part 34a where the height is higher on the convex part 33 side,
The lower part 34b has a lower height on the side of the nose part 32a. As a result, a standing wall portion 34c is formed between the high portion 34a and the bottom portion 34b, and a standing wall portion 34a is formed between the bottom portion 34b and the rake face. In addition, the height of the bottom part 34b
It is desirable that H ₃ is set to 1/10 to 8/10 of the height H ₂ of the high portion 34a.

In this case, the chip disposal range can be more reliably set from the range of low feed and low depth of cut to the range of high feed and high depth of cut than in the above-described embodiment. In other words, if the chip disposal range is simply a lower feed and lower depth of cut range, it is sufficient to form one low protrusion and bring its tip close to the nose part. However, in this case, when cutting is performed with a medium feed amount and a medium depth of cut, the chips will ride on the protrusion, and at this time, the chips will be gently curled with a large radius. Then, there is a possibility that it will extend for a long time without colliding with the convex portion. In this regard, according to this throw-away tip 3, when the feed rate is low and the depth of cut is low, chips are removed from the bottom 3.
It is abruptly curled and divided by the standing wall portion 34d of 4b. In addition, in the case of medium feed and medium depth of cut, the chips go over the low part 34b and then reach the high part 34b.
It collides with the standing wall part 34c of a, and the low part 34b and the high part 3
It is curled and separated by cooperation with 4a. Furthermore, in the case of high feed and high depth of cut, chips are
4b and the high portion 34a in order to reach the convex portion 33.
The lower portion 34b, the higher portion 34a, and the convex portion 33 cooperate to cause curling and separation.

In addition, the throwaway tip 4 shown in FIG.
Not only does the protrusion 44 consist of a high part 44a and a low part 44b, but also the width of the low part 44b is the same as that of the high part 4.
It is wider than the width of 4a. In addition, the lower part 4
The width of 4b is preferably set to 1.5 to 3 times the width of high portion 44a. This throwaway tip 4
is particularly suitable when thin and wide chips are produced, such as at low feed and high depth of cut.

Furthermore, the throwaway tip 5 shown in FIG.
This is a modification of the throw-away tip 4 shown in FIG. 4, in which the entire rake face 51 is a flat surface.

Next, by explaining the results of experiments conducted on the chip disposal range of the throw-away tip according to this invention and the conventional throw-away tip,
Let us clarify this idea further. In this experiment, the chip 2 shown in FIG. 2 was used as the throw-away chip according to this invention, and the chip 1 shown in FIG. 1 was used as the conventional throw-away chip. It goes without saying that both chips are made of the same material, size, etc., except for the protrusion, which is a feature of this invention. The specific dimensions and cutting conditions of both chips are as follows.

Chip dimensions Inscribed circle diameter 12.7mm Nose radius 0.8mm Thickness 4.76mm Cutting conditions Work material S45C Cutting speed 100m/mm The experimental results are shown in Figure 6. 6th
In the figure, the range indicated by is the chip disposal range of the conventional throw-away tip, and the range indicated by is the chip disposal range of the throw-away tip according to the present invention. As is clear from this, in the throw-away tip according to this invention, compared to the conventional throw-away tip, the chip disposal range is slightly narrower at high feeds and high depths of cut, but it is significantly narrower at low feeds and low depths of cut. As a result, the total chip disposal range can be made significantly wider than that of conventional throw-away tips.

In the above embodiment, the shape of the throwaway tip in plan view is triangular, but it may be a polygonal shape such as a square, or it may be circular. Further, the location where the convex portion and the protrusion are formed is not limited to the vicinity of the nose portion, but may be located near the straight portion of the cutting blade. moreover,
In the above embodiments, the height of the protrusion is made uniform or lowered stepwise; however, the height of the protrusion is not limited to this, and the height of the protrusion may be made from the convex side to the nose side. It may be gradually lowered.

As explained above, according to the throw-away tip of this invention, in the part between the cutting edge and the convex part that protrudes from the rake face with the cutting edge formed on the periphery and has a curved top, A protrusion is formed that protrudes from the rake face, is lower in height than the convex part, extends from the convex part toward the cutting edge side, and has a standing wall part formed on the cutting edge side from its top toward the rake face side. Therefore, the chip disposal range can be set at low feed and low depth of cut such as finish cutting without damaging the cutting edge or deteriorating the cut surface in the high feed and high depth of cut range. Furthermore, in high feed and high depth of cut cutting, the chips protrude from the rake face and can be reliably curled and separated by the convex portion having a curved top. Therefore, it is possible to obtain the effect that the total chip disposal range can be significantly widened. In addition, since the chips are curled by the curved convex portion when the cutting depth is high, the contact area with the chips is small. Therefore, the frictional resistance with chips is low, and cutting resistance does not increase.

[Brief explanation of the drawing]

Fig. 1 shows an example of a conventional throw-away chip, Fig. A is a plan view thereof, Fig. B is an enlarged sectional view taken along the X-X arrow of Fig. A, and Fig. C is an enlarged sectional view taken along the Y-Y arrow of Fig. A. , Figures 2 to 5 each show an embodiment of this invention, where Figure A is a plan view thereof, Figure B is an enlarged sectional view taken along the line X-X in Figure A, and Figure C is a cross-sectional view taken along the Y-Y line in Figure A. FIG. 6, an enlarged cross-sectional view in the direction of arrows, is a diagram showing the chip disposal ranges of the throw-away tip according to this invention and the conventional throw-away tip. 2, 3, 4, 5... Throwaway tip, 2
1,51...rake face, 22...cutting edge, 23,3
3...Protrusion, 24, 34, 44...Protrusion, 34
a, 44a...high part, 34b, 44b...low part.

Claims (1)

[Claims for Utility Model Registration] 1. A throw-away comprising a rake face with a cutting edge formed on its periphery, and a convex part that projects from the rake face and has a curved apex spaced apart from the cutting edge. In the chip, a portion between the convex portion of the rake face and the cutting edge,
A vertical wall portion is formed on the cutting edge side, protruding from the rake face, having a height lower than the convex portion, extending from the convex portion toward the cutting edge side, and extending from the top thereof toward the rake face side. Throwaway tip characterized by forming a protrusion. 2. The throw-away according to claim 1 of the utility model registration, characterized in that the height of the protrusion gradually decreases from the protrusion side toward the cutting edge side. Chip.