JPH0329046Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a throw-away tip used for turning, and relates to an improvement of a breaker for a throw-away tip that has a protrusion at the tip end.

[Conventional technology]

Conventionally, in turning work on steel, etc., in order to prevent the generation of continuous chips, throw-away chips were used, which had a breaker groove or protrusion on the top surface of the chip, and cut the chips into appropriate lengths without clogging them. (hereinafter sometimes simply referred to as "chip") is used.

As these chips, for example, the one shown in FIG.
A plurality of protrusions are provided in a breaker groove formed in the nose portion.

This chip has a breaker groove 14 along the cutting edge 13.
is formed, and there are two protrusions 1 near the nose part.
By providing the protrusions 5 and 16, during light cutting with a small depth of cut, the chips come into contact with the protrusions and are curled and separated.
In addition, during heavy cutting, the chips are curled in the breaker groove 14 and cut into pieces to dispose of the chips.

[Problem that the invention attempts to solve]

However, with this chip, when a pulling feed is applied in the direction of arrow A with depth of cut d as shown in FIG. The chips 17 are arranged so that the distances L ₁ and L ₂ from each cutting edge to the protrusions 15 and 16 in FIG. 9, which shows the cross section of FIG. 7, and FIG. 10, which shows the cross section, satisfy L ₁ <L _2. As a result, the curl radius of the chips becomes smaller at the protrusion 15, and the curl radius of the chips becomes larger at the protrusion 16, which curls toward the finished surface 18 as shown in FIG. 8, damaging the machined surface. It ends up.

It is an object of the present invention to solve the above-mentioned problems and to provide a throw-away tip that provides good chip control even in work involving pull cutting of end faces.

[Means for solving problems]

In order to achieve the above object, the present invention has the following structural requirements. That is, in a throwaway tip that is polygonal, has a breaker groove along the cutting edge, and has a plurality of protrusions on the bisector of the nose, the first protrusion is provided closest to the nose; A second spherical protrusion is formed so as to be separated from the protrusion by a certain distance or partially overlap with the protrusion, and a third truncated conical protrusion is provided to overlap only near the highest part of the second spherical protrusion. , and the shortest distance between the point where the first protrusion and the second spherical protrusion intersect with the breaker groove and the cutting edge is such that the distance to the first protrusion l ₁ > the distance to the second protrusion l ₂ The cutting edge is formed as shown in FIG. Features a throw-away tip.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings.

Fig. 1 shows a triangular throw-away tip of the present invention, and in Fig. 1a there are cutting edges on three sides.
A breaker groove 3 is formed from the land portion 2 toward the center of the chip, and a plurality of protrusions are provided on the bisector of the apex angle near the nose portion.

The protrusion has a second cross-section shown in FIG. 1a.
As shown in the figure, a first protrusion 4 is provided closest to the nose part, a second spherical protrusion 5 is formed so as to partially overlap with this, and a third spherical protrusion 5 is formed so as to overlap only near the top of the first protrusion 4. A truncated dome-shaped projection 6 is provided.

The protrusion 4 and the protrusion 5 are provided at approximately the same height as the cutting edge of the nose portion, and the protrusion lowering portion and the breaker groove 3
Fig. 3 shows the cross section of Fig. 1a and Fig. 4 shows the shortest distance between the intersection of
As shown in the figure, the distance between the first protrusion 4 and the l ₁ >second
By forming the protrusion 5 at a distance l ₂ , when a pulling feed is applied in the direction of arrow A with the depth of cut d in the pull cutting of the end face as shown in Fig. 5, the chip 7 is By making the chips 7 contact the protrusions 5 faster than the protrusions 4, the chips 7 can be curled in the feeding direction and can be discharged without hitting the finished surface 8. This makes it possible to prevent the finished surface from deteriorating after processing as in the conventional example. Here, the distance _l2 is narrowed by increasing the radius of the spherical protrusion 5, and the ejected chips contact the two contact points of the protrusion 4 and the protrusion 5, and are curled with low resistance without contacting the protrusion. Ru. As shown in Fig. 1b, the shape of the cutting edge 1 in side view is a combination of a straight cutting edge 1a near the nose and a concave cutting edge 1b having an inclined surface that descends toward the center of the cutting edge. By doing so, the direction of chip outflow is toward the center of the chip by the inclination angle of the inclined surface, so chips during pull cutting come into contact with the protrusion 5 more quickly, and chip control can be made more stable. .

Further, the projection 6 is positioned higher than the nose portion to form a flat portion, similar to the fourth projection 9 provided at a certain distance from the fourth projection 9 and the boss surface 10 formed continuously thereto. ing. By providing this third protrusion 6, the amount of protrusion from the cutting edge on the back side of the cutting edge can be reduced during cutting, thereby increasing the stability of holding the chip, resulting in an economical chip that can be used on both the front and back sides of the chip. can do.

Furthermore, as a preferable chip shape, the protrusion 9 is one end so as to be symmetrical with respect to the ridgeline of the boss surface 10, and the other end is curved toward the center of the chip and reaches the protrusion 11. Alternatively, the breaker groove 3 is a breaker groove 3 recessed along the cutting edge only between the protrusion and the protrusion 5, as shown in FIG. and a flat portion following it, and the flat portion 12 is formed lower than the cutting edge position. By doing as shown in Fig. 6, the contact area of chips during cutting is reduced by the breaker groove 3, which is formed in a substantially arc shape so that the rising part of the breaker groove is reduced, compared to the conventional example. It is possible to reduce the cutting force, and it is possible to process chips in good condition without clogging even in heavy cutting, and even in cutting with a high feed rate, the amount of chips that are ejected can be reduced. The breaker groove 3, protrusion 5, protrusion 9 and protrusion 1
By curling at one point of contact, cutting resistance can be reduced, making stable cutting possible. Furthermore, by providing the protrusion 11 near the cutting edge, it is possible to stabilize the chip seat in combination with the protrusion 9 and the boss surface 11 during cutting.

In the above embodiment, a triangular chip has been described, but the present invention can also be applied to a polygonal chip such as a square.

[Effects of the invention] As explained above, according to the invention, it is possible to process chips in a desirable shape and discharge them with low resistance even in work including pulling cutting of the end face, which was previously unsatisfactory. This provides a throw-away tip that makes it possible.

[Brief explanation of drawings]

FIG. 1 shows an embodiment of the throw-away chip according to the present invention, FIG. 1a is a front view thereof, and FIG. 1b is a front view thereof.
The figure is a bottom view, and Figures 2, 3, 4 and 6 are - and - in Figure 1a, respectively.
, - is a cross-sectional view showing the cross-sectional shape, FIG. 5 is an explanatory diagram of the processing state of chips during cutting, FIGS. 7 to 10 show a conventional example, and FIG. 7 is a front view thereof, and FIG. 8 is an explanatory view showing the processing state of chips during cutting, and FIGS. 9 and 10 are cross-sectional views showing the - and - cross sections in FIG. 7. 1... Cutting edge, 1a... Straight cutting edge ridge, 1b... Concave cutting edge ridge, 4... First protrusion, 5... Second spherical protrusion, 6... Third truncated dome shape protrusion.

Claims (1)

[Claims for Utility Model Registration] (1) In a throw-away tip that is polygonal, has a breaker groove along the cutting edge, and has a plurality of protrusions on the bisector of the nose, A first protrusion is provided nearby, a second spherical protrusion is formed at a certain distance from the protrusion or partially overlaps with the protrusion, and a third spherical protrusion is formed that overlaps only near the highest part of the second spherical protrusion. A truncated dome-shaped projection is provided, and the shortest distance between the cutting edge and the point where the first projection and the second spherical projection intersect with the breaker groove is a distance from the first projection l ₁ >second The cutting edge is formed so as to have a distance l ₂ from the projection to the protrusion, and furthermore, the cutting edge has a straight cutting edge near the nose and a concave cutting edge having an inclined surface that descends toward the center of the cutting edge when viewed from the side. A throw-away tip characterized by consisting of a combination with a blade ridge. (2) In the throw-away tip according to claim 1 of the utility model registration, the first and second protrusions are provided at approximately the same height as the cutting edge of the nose portion, and the first protrusion is located at the top of the tip. A throw-away chip characterized by being formed so as to be inclined toward the center of the chip. (3) In the throw-away chip according to claim 1 or 2 of the utility model registration claim, the third
The throw-away tip is characterized in that the protrusion is at the same height as the central boss surface, which is located higher than the height of the cutting edge of the nose part.