JPH073904U - Throw-away tip - Google Patents

Abstract

(57) [Summary] [Purpose] Strengthening the cutting edge strength of the nose part to improve chip disposability at low depth of cut. [Structure] On an upper surface 15 of a throw-away tip 13 having a substantially triangular plate shape, a ridge line of a cutting edge 18 connecting between the nose portions is an arc-shaped curved line 18a which is convex toward the lower surface 14. Fastening hole 6
The central bottom portion 21 around the circumference of the lower projections 23, 24 having a chevron shape in a longitudinal section in which the distance between the upper and lower surfaces gradually increases in the direction of each nose portion.
25 is provided. Center bottom 21 and low protrusions 23, 24, 2
On the outer periphery of 5, an inclined surface 11 is provided which is inclined toward the cutting edge 18 so that the distance between the upper and lower surfaces gradually increases.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a throw-away tip for cutting a relatively soft work material such as an aluminum alloy.

[0002]

[Prior art]

 Conventionally, as a throw-away tip of this type, there is one shown in FIGS. 6 to 9, for example. The throw-away tip 1 has a substantially triangular plate shape in a plan view, and has three acute-angled noses, a lower surface 2 which is a mounting surface for attaching to a holder (not shown) and an upper surface 3 which is a surface facing the mounting surface. The entire circumference of the ridgeline including the portions 4a, 4b, 4c and each side constitutes a cutting edge 5. A stepped hole 8 for fixing the chip 1 to a holder or the like is formed by penetrating the lower surface 2 from the center of the upper surface 3. Around the stepped hole 8 on the upper surface 3, a central bottom portion 10 having a smaller vertical distance than the portion of the cutting blade 5 is formed along the cutting blade 5, and in the nose portion direction of the central bottom portion 10, Center-bottomed bottom inclined portions 10a, 10b, 10c each having a substantially triangular shape in plan view are provided as rake faces, and are inclined so that the distance between the upper and lower surfaces gradually increases toward the nose portions 4a, 4b, 4c. There is.

Moreover, on the outer circumference of the central bottom portion 10 and the central bottom portion inclined surfaces 10a, 10b, 10c, there is provided an inclined surface 11 having a cutting edge 5 and the distance between the upper and lower surfaces gradually increasing in the direction of the cutting edge 5. Has been. This inclined surface 11 constitutes the rake face of the cutting blade 5. Each nose portion area of the inclined surface 11 is formed as a corner inclined surface 11a, 11b, 11c in which the distance between the upper and lower surfaces gradually increases in the direction of the cutting edge 5 as compared with the central bottom inclined portion 10a, 10b, 10c. There is.

Then, the rake angle γ1 of the corner inclined surfaces 11a, 11b, 11c of each of the nose portions 4a, 4b, 4c (see FIGS. 7 and 8) and the rake angle γ2 of the inclined surface 11 other than the corner inclined surfaces (see FIG. 7) are set to about 20 ° in each case. The inclination angle α of each central bottom surface inclined portion 10a, 10b, 10c is set to about 12 °, and the inclination angle λ of the cutting edge 5 forming the ridge of each corner inclined surface 11a, 11b, 11c is about 10 °. (See FIG. 8). Further, the angle β1 (see FIG. 8) formed by the corner inclined surface 11a (11b, 11c) at the tip of the nose portion 4a (4b, 4c) and the central bottom surface inclined portion 10a (10b, 10c), and the planar central bottom portion 10 The angle β2 (see FIG. 7) formed by the inclined surface 11 and the inclined surface 11 is set to be larger than 130 °. The angle θ in the longitudinal direction of each corner inclined surface 11a, 11b, 11c is set to about 8 ° (see FIG. 9). In the case of the throw-away tip 1 as described above, since the work material is relatively soft such as aluminum alloy, the cutting edge is sharp, the rake angle is large, and the chips are easily welded, so that it is configured as a positive tip. It

[0005]

[Problems to be Solved by the Invention]

 By the way, when cutting is performed using the throw-away tip 1, the cutting force is large because the rake angles γ1, γ2 of the cutting edge 5 are as large as about 20 °, but the cutting edges of the nose portions 4a, 4b, 4c are large. It has the drawback of low strength. Therefore, when cutting, there is no choice but to limit the maximum depth of cut and the maximum amount of feed, and there is a problem that cutting efficiency is poor. Moreover, in the case of a low depth of cut, the chips cut by the cutting edge 5 of the nose run from the corner inclined surface 11a to the central bottom inclined portion 10a and are bent and curled at the opposite corner inclined surface 11a. As a result, the diameter of the chips becomes relatively large, and the chips flow to the machined surface of the work material to damage the machined surface.

In view of the above problems, it is an object of the present invention to provide a throw-away tip that can improve the strength of the cutting edge, has good chip disposability, and has good sharpness.

[0007]

[Means for Solving the Problems]

 The indexable insert according to the present invention is provided with a plurality of nose parts on the upper surface facing the lower surface forming the seating surface, the ridge line on the outer periphery of the upper surface forms a cutting edge, and the periphery of the chip fixing part in the center of the upper surface is above and below the cutting edge. For cutting a relatively soft work material that forms a center bottom with a small distance and a rake face is formed as a rake face with the distance between the upper and lower faces gradually increasing from this center bottom toward the cutting edge. In the polygonal indexable insert, the ridgeline of the cutting edge that connects the nose parts is formed in a curved shape that is convex in the direction of the lower surface in side view, and also in plan view from the center bottom to the inclined surface of the nose part. A low protrusion having a tapered shape and a chevron shape in a vertical cross-section is provided, and the low protrusion is inclined from the center bottom side toward the nose side so that the distance between the upper and lower surfaces becomes second larger.

The rake angle of the cutting edge formed by the inclined surface is set in the range of 10 to 20 °, and the clearance angle of the flank formed by the side surfaces between the upper and lower surfaces is 5 to 25 °. It is characterized by being set in the range.

Further, the flank of the nose portion formed at the side crossing between the upper and lower surfaces is formed within a clearance angle of 5 to 25 ° by cutting the upper part of the side crossing, and further from the flank to the lower surface. The feature is that the angle of inclination at the side intersection in the direction is set to be larger than that of the flank.

Further, the low protrusion is characterized in that it is formed in a mountain shape on two opposite surfaces, and the inclination angle of its ridge is set to 5 to 7 °.

Further, the inclination angle of the tangent line passing through the end of the curved region of the cutting edge in side view is set in the range of 5 to 10 °.

[0012]

[Action]

 Since the cutting edge between the nose parts is formed in a curved shape and the rake face of the nose part is provided with a low protrusion, the cutting edge strength can be strengthened, and especially in the case of a low cutting depth, the chips are bent with a low protrusion. Since it is easily discharged to the outside, chips are less likely to damage the machined surface.

Further, since the rake angle and the clearance angle are large, it is suitable for cutting non-ferrous metal.

[0014]

【Example】

 Hereinafter, a preferred embodiment of the present invention will be described with reference to FIGS. 1 is a perspective view of a throw-away tip according to this embodiment, FIG. 2 is a plan view of the throw-away tip of FIG. 1, FIG. 3 is a side view of the throw-away tip of FIG. 1, and FIG. 4 is a vertical cross-sectional shape of a low protrusion. FIG. 5 is a sectional view taken along the line CC of FIG. The throw-away tip 13 according to the present embodiment is, for example, in the form of a plate having a substantially triangular shape in plan view as shown in FIG. 1, and has a lower surface 14 serving as a mounting surface for mounting on a holder (not shown) and an upper surface 15 facing the lower surface 14. And are provided. Further, a stepped hole 16 for fixing the chip 13 is formed by penetrating the lower surface 14 from the center of the upper surface 15. A ridgeline forming an outer periphery including three acute-angled (for example, about 60 °) nose portions 17a, 17b, 17c on the upper surface 15 constitutes a cutting edge 18. The ridges of the cutting blades 18 that connect the nose portions each form a concave curve slightly recessed in the direction of the stepped hole 16 in plan view (see FIG. 2), and each is a circle convex in the direction of the lower surface 14 in side view. The arcuate region 18a is formed (see FIG. 3). In each side of the cutting edge 18, both ends of the arc-shaped area 18a are connected to the cutting edges 18 of the other sides adjacent to each other at the nose portions 17a, 17b, 17c via the more sloping and gentle end areas 18b, 18b. Has been done. By constructing the ridgeline of the cutting edge 18 in this way, the plate thickness in the cutting edge 18 region near the nose portion becomes relatively large, and the strength of the cutting edge can be enhanced. Here, the inclination angle λ in the tangential direction from the end of the arcuate region 18a of the cutting edge 18 is set in the range of 5 ° to 10 °, which is 6 ° in this embodiment.

Around the stepped hole 16 on the upper surface 15, a substantially triangular flat central bottom portion 21 is formed along the cutting edge 18 with a distance between the upper and lower surfaces being smaller than that of the cutting edge. From the corners of the central bottom portion 21 toward the nose portions 17a, 17b, 17c, low protrusions 23, 24, 25 having a chevron shape (see FIG. 4) in longitudinal section are respectively formed as rake faces. These low protrusions 23, 24, 25 have a pair of mountain-shaped surfaces a1, a2 such that the distance between the upper and lower surfaces gradually increases from the stepped hole 16 side toward the nose portions 17a, 17b, 17c. Are inclined. Here, the angles ν between the surfaces a1 and a2 of the low protrusions 23, 24, and 25 are set to 150 to 170 °, respectively (see FIG. 4). Further, the inclination angle α of the ridge line a3 that forms the boundary between the surfaces a1 and a2 of the low protrusions 23, 24 and 25 is set in the range of 5 to 7 ° (see FIG. 5). The ridge line a3 is located at a position lower than the cutting edge 18 in this region. Here, if the angle ν of the low protrusions 23, 24, 25 is made larger than the above range, the position of the ridge line a3 becomes too high, and especially when cutting a soft work material such as an aluminum alloy, chips. Is easily welded to the surface a1 or a2, which is not preferable. By providing the above-mentioned low protrusions 23, 24, 25, the cutting edge strength of the nose portions 17a, 17b, 17c can be increased. Further, when cutting the work material with the cutting blades 18 near the nose portions 17a, 17b, 17c, the chips contact the one surface a1 or a2 of the low protrusions 23, 24, 25 and are curled. Has a small diameter, which makes it difficult to flow in the direction of the machining surface and is easy to discharge.

Further, on the outer periphery of the central bottom portion 21 and the low protrusions 23, 24, 25, the distance between the upper and lower surfaces gradually increases from the central bottom portion 21 and the low protrusions 23, 24, 25 toward the cutting edge 18. An inclined surface 26 is provided to form a rake surface. The rake angle γ1 of the inclined surface 26 in the nose portions 17a, 17b, 17c and the rake angle γ2 of the inclined surface 26 in the areas other than the nose portions 17a, 17b, 17c are in the range of 10 to 20 °, respectively. In the embodiment, it is set to 13 °. Further, the inclination angle θ along the longitudinal direction of each inclined surface 26 near the low protrusions 23, 24, 25 is set to about 6 °.

On the peripheral side surface of the throw-away tip 15, a portion excluding the areas of the nose portions 17a, 17b, 17c constitutes a flank 28. In the region of each nose part 17a, 17b, 17c, the upper part is cut in a triangle toward the nose part to form a nose part flank 30 at an intersection part 29 where two side faces of each side intersect. (See Figure 1). Therefore, in each of the nose portions 17a, 17b, 17c, the flank is formed by two steps, that is, the flank 30 of the nose and each side crossing portion 29 having a larger clearance angle than the flank 30. . Here, the clearance angles δ of the flanks 28 and the nose flanks 30 are set in the range of 5 to 25 °, respectively, and in this embodiment, 20 °. Further, the combined clearance angle ε of the nose flank 30 and the side crossing 29 of each nose 17a, 17b, 17c is set to about 36 ° (see FIG. 3).

Since the present embodiment is configured as described above, when the throw-away tip 15 is attached to a holder (not shown) to cut a non-ferrous metal or the like, for example, an aluminum alloy or the like, for example, a rake angle γ1 , Γ2 is a positive angle of 13 °, the clearance angle δ is 20 °, and the combined clearance angle ε of the nose part is set to 36 °. Both the rake angle and the clearance angle are large, so the cutting force is large. high. Also, especially in the case of a low depth of cut, the chips generated by cutting with the nose portion 17a, 17b, or 17c are guided by the inclined surface 26 and one surface a1 or a2 of the low protrusion 23, 24, or 25. And is bent into a relatively small diameter. Moreover, as shown in FIGS. 1 and 2, the widths of the surfaces a1 and a2 of the low protrusion 23 and the like are widened from the side of the nose portion 17a and the like toward the cutting hole 16, The chips are sent away from the machined surface in the direction of the cutting hole 16 and discharged. Therefore, the chips are unlikely to damage the machined surface.

As described above, according to this embodiment, the ridgeline of the cutting edge 18 connecting the nose portions is formed in the arc-shaped region 18a, and moreover, the rake face of the nose portions 17a, 17b, 17c is formed. Since the low protrusions 23, 24, 25 are formed, the cutting edge strength of the nose portions 17a, 17b, 17c can be particularly strengthened. Therefore, it is not necessary to reduce the maximum depth of cut and the maximum amount of feed unlike the prior art. Further, since the low protrusions 23, 24, 25 are provided, the curl diameter of chips and the discharge direction can be controlled especially at low depth of cut, and the possibility of damaging the machined surface is small, and the chips may be welded. small. Further, the throw-away tip 15 according to this embodiment has a large rake angle and a large clearance angle, and is therefore suitable for cutting a relatively soft work material such as non-ferrous metal.

Incidentally. In the above-described embodiment, the throw-away tip 15 is formed in a substantially triangular plate shape, but the shape of the throw-away tip is not limited to the shape of the embodiment, and the throw-away tip may be a square plate or another appropriate polygonal shape. It can be used for away chips.

[0021]

[Effect of device]

 As described above, in the throw-away tip according to the present invention, the ridge line of the cutting edge that connects between the nose portions is formed in a curved shape that is convex in the lower surface direction in side view, and it extends from the central bottom portion to the inclined surface of the nose portion. A low protrusion that is generally tapered in plan view and has a chevron shape in a vertical cross section is formed.The low protrusion is inclined so that the distance between the upper and lower surfaces gradually increases from the center bottom side toward the nose side. It is possible to enhance the strength of the cutting edge of the part, and at the same time, improve the processability of chips, especially at low depths of cut, and reduce the risk of chips scratching the machined surface. Moreover, the welding of chips to the low protrusions is unlikely to occur. Further, since the rake angle and the relief angle are set to be large, it is suitable for processing non-ferrous metal such as aluminum alloy.

[Brief description of drawings]

FIG. 1 is a perspective view of a throw-away tip according to an embodiment of the present invention.

FIG. 2 is a plan view of the throw-away tip shown in FIG.

FIG. 3 is a side view of the throw-away tip of FIG.

FIG. 4 is a view showing a vertical cross-sectional shape of a low protrusion.

5 is a cross-sectional view taken along line CC of FIG.

FIG. 6 is a perspective view of a conventional throw-away tip.

7 is a sectional view of the throw-away tip of FIG. 6 taken along the line AA.

FIG. 8 is an enlarged view of the nose portion of FIG.

9 is a sectional view of the throw-away tip of FIG. 6 taken along the line BB.

[Explanation of symbols]

 13 Throw-away tip 14 Lower surface 15 Upper surface 17a, 17b, 17c Nose portion 18 Cutting edge 21 Central bottom portion 23, 24, 25 Low protrusion 26 Sloping surface 28 Flank surface 29 Intersection 30 Corner flank surface

Claims (5)

[Scope of utility model registration request] 1. A plurality of nose portions are provided on an upper surface facing a lower surface which forms a seating surface, a ridge line on the outer periphery of the upper surface forms a cutting edge, and a chip fixing portion around the center of the upper surface has a distance between upper and lower surfaces than the cutting edge. A polygonal shape for cutting a relatively soft work material, which forms a small central bottom portion, and is formed as a rake surface with an inclined surface in which the distance between the upper and lower surfaces gradually increases from the central bottom portion toward the cutting edge. In the throw-away tip, the ridge lines of the cutting edges that connect the nose portions are each formed in a curved shape that is convex in the lower surface direction in a side view, and are tapered in a plan view from the central bottom portion toward the inclined surface of the nose portion. In addition, a throw-away tip is provided with low protrusions each having a chevron shape in a longitudinal cross-section, and the low protrusions are inclined so that the distance between the upper and lower surfaces gradually increases from the center bottom side toward the nose side. 2. The rake angle of the cutting edge formed by the inclined surface is set in the range of 10 to 20 °, and the clearance angle of the flank formed by the side surfaces between the upper and lower surfaces is 5 to 25 °. The throw-away tip according to claim 1, wherein the throw-away tip is set in a range. 3. Formed at a side surface intersection between the upper and lower surfaces,
The flank of the nose portion is formed in the range of a clearance angle of 5 to 25 by cutting the upper part of the flank, and the flank of the flank from the flank to the lower surface has a larger inclination angle than the flank. The throw-away tip according to claim 1 or 2, wherein the throw-away tip is provided. 4. The low protrusion is formed in a mountain shape on two opposite faces, and the inclination angle of the ridge line thereof is set to 5 to 7 °. Throw-away tip. 5. The inclination angle of a tangent line passing through the end of the curved region in side view of the cutting edge is set in the range of 5 to 10 °. Throw-away tip.