JPH0115442Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a throw-away tip for cutting, and more specifically, to an improvement of a chip breaker groove to widen the range of operating conditions in which continuous chips can be broken into desired shapes. It is.

In cutting work that generates continuous long chips such as steel, etc., it is necessary to curl the chips and further divide them into appropriate sizes from various points of view, such as safety, ease of work, and automatic chip conveyance. is necessary. For this reason, cutting tools that have grooves or protruding obstacles (collectively referred to as chip breaker grooves) that curl and break up chips near the cutting edge, especially throw-away tips, are used for one-step transport. ing.

FIG. 1 is a plan view showing an example of a conventional throw-away chip having a chip breaker groove.
By forming this chip breaker groove, a protruding portion 6 is provided extending from the remaining central land portion 4 toward the corner portion 5. FIG. 2 is an enlarged plan view of the vicinity of the corner in FIG. 1, in which the protrusion 6 toward the corner tapers linearly, and the tapered tip intersects perpendicularly to the bisector of the corner. It is cut in the shape. Furthermore, FIG. 3 shows another example of a conventional throw-away chip having a chip breaker groove, and FIG. 4 shows an enlarged plan view of the vicinity of the corner of FIG. 3. The tip of the protruding portion 6 toward the corner portion is rounded.

As shown in FIGS. 2 and 4, the conventional product having the above-mentioned protrusion into the corner part is located at the intersection 9 of the ridge 7 of the protrusion 6 and the bisector of the corner, A contact 10 is normally present.

In general, the distance from the cutting edge 2 to the rising ridge of the breaker groove 3, that is, the ridge 7, mainly determines the curling and separation of chips, and determines the normally usable feed rate range. That is, the shorter the distance, the better the chips will curl and break even if the feed amount is small, but on the other hand, if the feed amount is increased, the chips will curl and break more than necessary. The throw-away tip of the above conventional example is designed to exhibit relatively good chip control performance even in finishing cutting with small feed rate and depth of cut, and is mainly based on the position of the closest point 10 (distance from the cutting edge). The lower limit of the feed amount was determined by: Therefore, there is a difficult-to-use cutting condition range in which chips are curled and broken more than necessary even with a slight increase in the feed rate. Figure 5 shows the first
The conventional throw-away tip illustrated in the figure (however, the distance from the straight side cutting edge to the nearest point 10 is
1.3mm, and the distance to intersection 9 is 1.6mm. )
FIG. 3 is a feed amount--depth of cut area diagram showing a usage condition area. The hatched area in FIG. 5 is the condition range in which a good chip shape is generated. As is clear from this, when the depth of cut is about 2 mm, the allowable upper limit of the feed amount is significantly lowered. Such a throw-away tip is not suitable for cutting operations where the depth of cut varies, such as profile cutting or when the machining allowance of a workpiece varies. The reason why the permissible upper limit of feed rate decreases abnormally at a certain depth of cut is as follows.
As shown in FIG. 2, since the ridge 7 of the protrusion 6 toward the corner protrudes in a direction perpendicular to the bisector of the corner, there is a closest point 10 to the straight cutting edge; Therefore, when the depth of cut is such that the chips mainly collide with the closest point 10, it was thought that due to the shape, the smooth outflow of the chips would be inhibited and unreasonable curling and separation would occur.

The main conditions for the area test shown in FIG. 5 are as follows.

Work material: SCM-435 (H _B = 170~200) Throwaway tip: TNMG432 Throwaway holder: Side edge angle = 0° Cutting speed: 100m/min Dry longitudinal continuous turning Chip control evaluation method: Precision In the "Chip shape classification method" edited by the Japan Society of Mechanical Engineers, Cuttability Expert Committee, type 3 (up to segmented type) is considered better than type 6 in the main classification.

Furthermore, FIG. 6 is a plan view showing an example of another conventional throw-away chip having a chip breaker groove, and FIG. 7 is an enlarged plan view of the vicinity of the corner portion of FIG. 6. In this conventional example, there is no nearest point 10 as shown in FIG. 2 described above, and the protrusion 6 is formed by a linear ridge 7. Chips from the throw-away tip of this conventional example (the distance from the straight cutting edge to the intersection 9 is 1.0 mm, and the angle θ is 15 degrees) were measured under the same conditions as those used to obtain the data in Figure 5. FIG. 8 shows the results of obtaining a region diagram of feed amount vs. depth of cut indicating processing performance. The hatched area in FIG. 8 is the condition range in which a good chip shape is generated. In the case of this conventional example, the allowable upper limit of the feed amount does not abnormally decrease at a certain depth of cut, but the usable limit is when the depth of cut is approximately 3 mm, and when the depth of cut is greater than this,
Since the chips collide with the entire area of the ridge 7, unnecessarily curling and splitting of the chips and significant "chattering" occur.

In view of the above-mentioned points, the present invention eliminates unnecessarily curling and breaking of chips at a specific depth of cut, and at the same time provides a well-balanced usage area that can be used when the depth of cut is large. To provide a throw-away chip having a chip breaker groove with excellent waste disposal properties.

That is, the present invention provides a throw-away tip 1 having a polygonal plate shape and having a breaker groove 3 along the entire circumference of an outer cutting edge 2 on at least one upper surface (rake surface) forming the polygon. , a protrusion 6 is formed into the breaker groove 3 from the remaining central land portion 4 toward the corner portion 5 due to the formation of the breaker groove 3, and the ridge 7 of this protrusion 6
is a circular arc that is convex toward the outer cutting edge so that it intersects on the bisector of the angle forming the corner, and the tangent angle at the intersection on the bisector is 1/2 to 1/2 of the angle forming the corner. This is a throw-away tip characterized by an arcuate edge that is 1/4 of the radius.

This will be explained in more detail in Examples below.

FIG. 9 is a plan view of a throw-away tip 1 showing an example of the present invention, in which a breaker groove 3 is provided along the outer peripheral cutting edge 2, and the remaining central land portion 4 extends from the corner by forming the breaker groove 3. A protruding portion 6 is formed into the breaker groove 3 toward the portion 5. FIG. 10 is a partially enlarged plan view near the corner of FIG. 9, showing the features of the present invention. That is, the ridges 7 of the protrusion 6 from the central land portion 4 intersect on the bisector of the corner with an arc convex toward the cutting edge, and the tangent to the ridge 7 at the intersection 9 and the bisector of the corner The angle θ formed by this corner is the bisector of the corner, that is, 45° in the case of the rectangular throw-away chip of this embodiment. Note that the dashed dot line 11 in Figure 10
indicates the groove bottom of the breaker groove 3. Further, FIG. 11 is a partially enlarged sectional view taken along the line A-A in FIG. 9, showing that the upper surface of the protruding portion 6 is connected to the upper surface of the central land portion 4 on the same plane.

Furthermore, FIG. 12 shows another example of the invention.
FIG. 3 is a partially enlarged plan view of the vicinity of a corner portion. In this embodiment, the protruding part 6 does not have an upper flat surface part and protrudes into the breaker groove 3 while being inclined. Imaginary intersection line 8 showing the continuity of intersections with
are circular arcs that are convex toward the cutting edge and intersect on the bisector of the corner, and the angle θ between the tangent to the intersection line 8 at the intersection 9 and the bisector of the corner is 30°. It's a chip. Note that the dashed dotted line 11 in FIG. 12 indicates the groove bottom of the breaker groove 3.

As shown in the above embodiments, the present invention is such that the protrusion 6 is closest to the cutting edge at the intersection 9 on the bisector of the angle forming the corner, and the protrusion 6
The edge 7 of the ridge 7 has an arcuate shape. The present invention is usually manufactured by stamping, and the throw-away chip of the present invention is used when manufacturing the mold used at this time, or when processing the cutting edge with free abrasive grains in the final process of manufacturing. Intersection 9 of protrusion 6 of
A slight roundness is formed. The radius of this roundness is
It should be 0.2mm or less, preferably 0.1mm or less.

Using the throw-away tip of the example shown in Fig. 9 (distance from the straight cutting edge to the intersection point 9 is 1.0 mm), the applicable range of feed rate - depth of cut was determined under the same cutting test conditions as in the conventional example described above. Ta. FIG. 13 shows this result. The hatched area surrounded by a solid line is the applicable area of the throw-away chip of the present invention, and the broken line is a comparison of the conventional throw-away chip shown in FIG. 5. It shows. As is clear, neither the depth of cut nor the feed amount is uniquely unusable under certain conditions, and the cutting application area is generally well-balanced. Furthermore, the present invention can be used even in a region where the feed rate is low, although this example is better than the conventional one in this respect as well.
A throw-away tip having a well-balanced cutting application area, such as the above-mentioned throw-away tip of the present invention, is highly desirable especially for cutting where the depth of cut varies, such as copy cutting.

In the case of the above embodiment, the tangent angle θ (see FIG. 10) at the intersection point 9 is equal to 45°, that is, the bisector angle of the corner. If the tangent angle θ is greater than or equal to the bisector of the corner, the closest point 10 will occur as illustrated in FIG. 2 or FIG. 4, which will impede the purpose of the present invention. In addition, if the tangent angle θ is less than the quarter angle of the corner, the tip of the protruding part will become too sharp and the protruding part will become too thin, causing problems in terms of strength and may break due to collision with chips. . In addition, when the tangent angle θ is made smaller than 1/4 of the angle forming the corner part,
As shown in the embodiment of FIG.
It is better to have a shape that protrudes while sloping inward.

From the above, the range of the angle θ is set to be less than or equal to the bisector of the angle forming the corner and greater than or equal to the quarter of the angle forming the corner.

Furthermore, the gist of the present invention is to improve the shape of the protruding tip of the protruding part 6, and therefore it is possible to improve the shape of the protruding tip of the protruding part 6. Application examples of the invention include a throw-away chip in which the main breaker groove 3 changes in the width direction of the breaker as shown in Fig. 15, a throw-away chip in which the height of the cutting edge changes as shown in Fig. 16, etc. The present invention is also applicable to In particular, as a throw-away tip for profile cutting as mentioned above, the protrusion-shaped throw-away tip of the present invention, in which the breaker groove changes in the width direction and the cutting edge height changes toward the center, is suitable. It exhibited very good chip control performance.

As described above, the throw-away tip of the present invention has a well-balanced cutting area without any special areas where chips curl or break up more than necessary, and at the same time extends the area of use to areas with low feed rates. This chip has significantly improved chip control performance than conventional throw-away tips.
It is highly effective for copy cutting using NC machines.

[Brief explanation of the drawing]

Figure 1 is a plan view showing an example of a conventional throw-away chip with a breaker groove, and Figure 2 is a plan view of an example of a throw-away chip with a conventional breaker groove.
FIG. 3 is an enlarged plan view of the vicinity of a corner of the figure. FIG. 3 is a plan view showing an example of another conventional throw-away chip having a breaker groove, and FIG.
FIG. 4 is an enlarged plan view of the vicinity of the corner portion of FIG. 3; FIG. 5 is a field diagram of the feed amount vs. depth of cut showing the chip control performance of the conventional throw-away tip shown in FIG. FIG. 6 is a plan view showing still another conventional example of the throw-away tip, and FIG.
The figure is an enlarged plan view of the vicinity of the corner of FIG. 6. FIG. 8 is a field diagram of the feed amount vs. depth of cut showing the chip control performance of the conventional throw-away tip shown in FIG. Figure 9 shows the first part of the present invention.
FIG. 10 is a plan view of a throwaway tip showing an embodiment of the present invention, and FIGS.
FIG. 2 is an enlarged plan view of the vicinity of a corner portion of the figure and a partial enlarged cross-sectional view of a section A-A. FIG. 12 is an enlarged plan view of the vicinity of a corner of a throw-away chip showing a second example of the present invention. FIG. 13 is a field diagram of the feed amount vs. depth of cut showing the chip control performance of the throw-away tip of the present invention shown in FIG. 14, 15, and 16 show other application examples of the present invention, in which FIG. 14 is an enlarged plan view near the corner, FIG. 15 is a plan view of the throw-away tip, and FIG. The figure is a side view of the throw-away tip. 1: Throwaway tip, 2: Peripheral cutting edge,
3: Breaker groove, 4: Central land portion, 5: Corner portion, 6: Projection, 7: Ridge of projection, 8: Intersection line of plane parallel to the top surface and projection, 9: Ridge of projection or A point on the bisector of the corner of the line of intersection, 10: The ridge of the protrusion relative to the linear peripheral cutting edge or the closest point of the line of intersection, 11: Bottom of the breaker groove.

Claims (1)

[Scope of utility model registration request] In the indexable tip 1, which has a polygonal plate shape and has a breaker groove 3 along the entire circumference of the outer peripheral cutting edge 2 on at least one upper surface forming the polygon, the upper surface is A protrusion 6 is formed into the breaker groove 3 from the remaining central land portion 4 toward the corner portion 5, and furthermore, the ridge 7 of the protrusion 6 intersects on the bisector of the angle forming the corner portion. As shown in FIG. A throw-away chip characterized by an arcuate edge that is less than or equal to a bisector angle and greater than or equal to a quarter angle.