JP2007260842A - Cutting insert and cutting tool furnished with it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cutting insert used for finishing cutting work in a cutting region small in cutting and feeding and excellent in a cutting chip discharging property by certainly curling chips even when a cutting material is a material rich in ductility such as low carbon steel and stainless steel. <P>SOLUTION: This cutting insert is furnished with: a main body part formed in a roughly polygonal plate shape; a rake face 3 formed on an upper surface of the main body part; a seating surface 2 formed on a lower surface of the main body part; a flank 4 formed on a side surface of the main body part; a cutting blade 5 formed at least on one part of a crossing crest line part of the rake face surface 3 and the flank 4; and a projected part 6 formed by having a top part in correspondence with the cutting blade 5. In this case, a chip sliding part 9 is formed at least on one part in the region sandwiched between the cutting blade 5 and the top part 7 of the projected part on the rake face 3, and the maximum height roughness at the chip sliding part 9 is made largest on the rake face 3. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a cutting insert used for cutting a metal or the like, in particular, a finish cutting of a material having high ductility such as low carbon steel or stainless steel.

Conventionally, as a cutting insert used for cutting a metal or the like, as shown in Patent Document 1, a protrusion-like shape is formed at the tip of an inclined surface protruding from the boss surface at the center of the cutting insert body toward the tip of the corner of the cutting insert. A cutting insert having a configuration in which a step portion is formed is known. Projecting Okoshijo stepped portion becomes sandwiched in a plane that theta ₁ inclined towards the front end which is formed on the corner portion side, and theta ₂ inclined surface toward the tip formed in a boss surface, these The inclination angle is configured to satisfy θ ₁ > θ ₂ . By adopting such a configuration, the chips flowing out from the cutting edge are appropriately sized by deforming the chips on the inclined surface of θ ₁ even under the cutting conditions with a small depth of cut and feed in the finish cutting region. It can be curled and divided.
Japanese Utility Model Publication No. 7-15206

  However, even with the cutting insert having the above configuration, when the work material is a material having high ductility such as low carbon steel or stainless steel, the chips are slipped on the inclined surface, and are not easily curled and generated. The chips are not divided at the protruding stepped portion as described above, but easily get over the protruding stepped portion. As a result, there has been a problem that the expanded chips are entangled with the work material and the holder, and the surface of the product is damaged, or the holder and the cutting insert are damaged.

  The present invention has been made to solve such problems of the prior art, and particularly in a cutting insert used for finishing cutting in a cutting region where cutting and feeding are small, the work material is low carbon steel or stainless steel. Even in the case of a material having high ductility such as steel, it is an object to provide a cutting insert that is capable of curling chips reliably and having excellent chip discharge performance.

  In order to solve the above problems, a cutting insert according to the present invention includes a main body portion formed in a substantially polygonal plate shape, a rake face formed on the upper surface of the main body portion, and a seat formed on the lower surface of the main body portion. A cutting edge formed on at least a part of a surface, a flank formed on a side surface of the main body, a ridge line portion between the rake face and the flank, and the cutting edge on the rake face. In a cutting insert comprising a protrusion formed correspondingly, and at least a part of a region sandwiched between the cutting edge and the top of the protrusion in the rake face, A chip sliding portion is formed, and the maximum height roughness in the chip sliding portion of the rake face is the largest.

  With such a configuration, the chips generated by cutting pass through the chip sliding portion having the largest maximum height roughness on the rake face even when the work material is rich in ductility. By this, it is possible to decelerate to a sufficient traveling speed before reaching the projection where the chips are curled. Therefore, the chips are easily curled and broken at the protrusions without the chips getting on the protrusions. Therefore, even under cutting conditions where cutting and feeding are difficult, such as when cutting and feeding are difficult, especially when cutting a work material with a high ductility, the chip extends and winds around the holder and the work material. Can be suppressed. As a result, it is possible to prevent the surface of the product from being damaged, and to finish the product with excellent processing surface accuracy, and it is possible to extend the life of the cutting insert and the holder.

  Further, the chip sliding portion is formed to have a plurality of crests, and the ridge line of the crests is substantially perpendicular to the cutting edge. Even in a non-constant processing mode, it is desirable to reduce the entry speed of the chips into the protrusions so that the chips are easily curled by the protrusions.

  Furthermore, when the work piece is rich in ductility, the chip sliding portion is formed to have a plurality of ridges, and the ridge line of the ridges is substantially parallel to the cutting edge. Also in the processing, the generated chips come into contact with the ridge lines of the plurality of peak portions, so that an appropriate impact is given to the chips, and the approach speed of the chips into the projecting portions is reduced. This is desirable because the curling action of the chips can be enhanced.

  Moreover, in order to solve the said subject, the cutting tool of this invention mounts the said cutting insert, It is characterized by the above-mentioned.

  With such a configuration, the generated chips are broken even under cutting conditions where cutting and feeding are small, even when the work material is a ductile material such as low carbon steel or stainless steel. Therefore, it is possible to prevent the chips from being stretched and effectively curl the chips with the projections and discharge them. As a result, winding of chips on the holder and product damage can be suppressed, so that the life of the cutting insert and the holder can be extended, and the processing accuracy is also excellent.

  According to the cutting insert of the present invention, the chip sliding portion is formed in at least a part of the region sandwiched between the cutting edge and the top of the projection portion, and the chip sliding portion of the rake face is in the chip sliding portion. Since the maximum height roughness is configured to be the largest, the generated chips pass through the chip sliding portion having the largest maximum height roughness, and the traveling speed is reduced. Therefore, even if the chip is rich in ductility and easily stretched, it is possible to prevent the chip from riding on the protrusion by effectively curling the chip. As a result, winding of chips on the holder and product damage can be suppressed, so that the life of the cutting insert and the holder can be extended, and the processing accuracy is also excellent.

  Embodiments of the present invention will be described below with reference to the accompanying drawings.

  1 to 4 show an embodiment of the present invention. FIG. 1 is an overall perspective view of a cutting insert (hereinafter abbreviated as an insert) 1 according to a first embodiment of the present invention, and FIG. FIG. 2 is a plan view of the insert 1 in FIG. 1. FIG. 3 is an enlarged view of a main part of the insert 1 of FIG. 1 and the inserts according to the second to fourth embodiments of the present invention. Moreover, FIG. 4 is (a) principal part enlarged view of the insert 1 by 1st embodiment, (b) AA sectional drawing. FIG. 5 is a comparative example of the insert 1, (a) an enlarged view of a main part of the insert 101, and (b) a cross-sectional view taken along line AA.

  In FIG. 1, an insert 1 according to the first embodiment is formed in a substantially polygonal plate-like main body, specifically, a rhombus plate shape. A seating surface 2 is formed on the lower surface of the main body, a rake surface 3 is formed on the upper surface of the main body, a flank 4 is formed on the side surface of the main body, and a cutting edge 5 is formed on at least a part of the intersecting ridge line portion between the rake surface 3 and the flank 4. It is formed. And on the rake face 3, the protrusion part 6 extended toward the cutting edge 5 located in an acute angle corner part is formed.

  The protruding portion 6 has a top portion 7 of the protruding portion formed above the insert from the cutting edge 5, and a side wall portion 8 of the protruding portion sandwiched between the top portion 7 of the protruding portion and the cutting edge 5. The top portion 7 of the protrusion is formed so that the width becomes narrower from the center of the insert 1 toward the acute corner portion. Further, the side wall portion 8 of the protruding portion is configured by an inclined surface that is inclined from the top portion 7 of the protruding portion toward the rake face 3.

  Further, a chip sliding portion 9 is formed on the rake face 3 in at least a part of a region sandwiched between the cutting edge 5 and the top portion 7 of the protruding portion. That is, in the present embodiment, the chip sliding portion 9 is formed in a region including a rake face portion from the cutting edge 5 to the side wall portion 8 of the protrusion and the side wall portion 8 of the protrusion.

  In FIG.5 (b), the comparative example of the cutting insert 1, the principal part enlarged view of the insert 101, and AA sectional drawing are shown. The insert 101 has a cutting edge 105 formed at a part of an intersecting ridge line portion of the rake face 103 and the flank face 104, and a protrusion 106 is formed on the rake face 103 corresponding to the cutting edge 105. The Further, the rake face region sandwiched between the cutting edge 105 and the top portion 107 of the protruding portion has the same surface configuration as that of the rake face other than the region, that is, a burnt surface. With such a configuration, when the rigidity of the chips generated by the cutting edge 105 is high, the insert 101 is partially curled at the same time as the chips are generated by the cutting edge 105. For this reason, such a highly rigid chip collides with the protrusion 106 while being curled to some extent, and is curled at the upper portion of the inclined portion 108 of the protrusion, sometimes broken and discharged. However, under cutting conditions with small incisions and feeds, the chips are thin and insufficiently rigid, so that the chips are not curled at the same time as they are generated. It becomes easy to grow. In particular, in the case where the work material is a material having high ductility, the chips generated by the cutting edge 105 pass in a stretched state so as not to be subjected to friction through a part of the rake face 103 made of a grilled surface. In this case, the collision with the projecting portion 106 is vigorous, so that it often does not curl but rides on the top portion 107 of the projecting portion. For this reason, the chips that are not curled and extend easily tend to be wound around the work material and the holder, tending to lower the finishing accuracy and shorten the holder life.

  On the other hand, as shown in FIGS. 4A and 4B, the insert 1 of the present invention has a chip sliding portion 9 in a part of a region sandwiched between the cutting edge 5 and the top portion 7 of the protruding portion. Is formed. And this chip | tip slide part 9 is comprised so that the maximum height roughness may become the largest among the rake faces 3. FIG. That is, in the insert 101, the chip sliding portion 9 is formed in an area that contributes to the chip curling action by contacting the chip among the rake face areas having the same surface configuration as the burnt surface, Unlike the other rake face regions, the chip sliding portion 9 is formed with minute irregularities. Thereby, the traveling speed of the chips generated by the cutting edge 5 is reduced by the generated friction and impact while passing through the chip sliding portion 9 having the largest maximum roughness. As a result, the cutting speed of the chips differs on the tip side (projection part side) and the end side (cutting blade side) of the chips, and is compressed on the tip side of the chips, thereby increasing the thickness of the chips. Then, the chips whose thickness is increased reach the side wall portion 8 of the protruding portion in a state in which the traveling speed is reduced, and thus are easily curled and broken above the side wall portion 8 of the protruding portion. As described above, according to this configuration, when the chips reach the protrusions 6, it is possible to create an environment in which the chips are easily curled and broken. Therefore, even if it is the cutting of the material rich in ductility, the shape of the chips can be controlled, and the chips can be prevented from being wound around the holder or the work material. As a result, the holder life can be extended and finishing accuracy can be increased.

  Preferably, the maximum height roughness of the chip sliding portion 9 is 5 μm to 10 μm. When the maximum height roughness of the chip sliding portion 9 is less than 5 μm, the ductile rich chips slip and pass through the chip sliding portion 9 with almost no friction and impact, and the chip traveling speed. It is difficult to create an environment where chips are curled and broken easily. Therefore, the chips are easily curled without being curled, and are easily wound on the holder and the work material by riding on the top 7 of the protrusion. Moreover, when the maximum height roughness of the chip sliding portion 9 is larger than 10 μm, the convex portion of the chip sliding portion 9 is too large, and similarly to the protruding portion 6, the effect of reducing the advancement speed of the chip is exhibited. It is easy for the cut chips and chips to ride on the convex portions of the chip sliding portion 9. As a result, in the side wall portion 8 of the protruding portion, the traveling speed is fast and the chips easily reach in a state where the thickness is not sufficient.

  In addition, the maximum height roughness in the above-described chip sliding portion 9 and other rake face regions is measured by, for example, a contact-type surface roughness measuring instrument, a non-contact-type laser microscope, or the like, respectively, The average value can be the maximum height roughness.

  In addition, since the uneven shape that has a large influence on the chip traveling direction, such as breaker protrusions and breaker grooves that are generally formed on the rake face, has a step of about 0.1 mm to It does not have the maximum height roughness at the breaker protrusion etc. with a step. That is, the maximum height roughness in each part on the rake face is measured on each constituent face that constitutes the breaker protrusion, the breaker groove, and the like.

  Here, the insert 1 according to the present embodiment is formed on the side wall portion 8 of the protruding portion in the region where the chip sliding portion 9 is sandwiched between the cutting edge 5 and the top portion 7 of the protruding portion. In addition, the chip sliding portion 9 is formed to have a plurality of peak portions so as to have the largest maximum height roughness in the rake face 3. Further, the ridge line of the peak portion is formed so as to be substantially perpendicular to the cutting edge 5. With such a configuration, even under cutting conditions in which chips are conventionally stretched without being curled, the chips come into contact with a plurality of ridges of the chip sliding portion 9 so that the chips and the chip sliding are performed. Appropriate friction and impact can be generated between the portion 9 and the portion 9. As a result, the approach speed to the protrusion can be reduced, the thickness of the chip at the protrusion 6 can be ensured, and an environment in which the chip can be easily curled and broken at the protrusion 6 can be created. Further, even in a machining mode in which the chip generation direction is not constant, such as copying, the cutting speed of the chip into the protrusion is reduced and the direction of movement of the chip is adjusted so that the chip is generated at the protrusion. This is desirable because it is easily curled.

  Next, inserts according to second to fourth embodiments of the present invention will be described with reference to FIGS. In addition, description is abbreviate | omitted about the structure same as the insert 1 by 1st embodiment here.

  As shown in FIG. 3 (b), the chip sliding portion 29 of the insert 21 according to the second embodiment is formed between the cutting edge 5 and the protruding portion in the region sandwiched between the cutting edge 5 and the top portion 7 of the protruding portion. It is formed in a rake face region sandwiched between the side wall portions 8. According to the present embodiment, the cutting speed is surely cut into the protruding portion 6 (side wall portion 8 of the protruding portion) even under cutting conditions in which cutting and feeding are small and elongated chips are easily generated. Can be dropped before the trash reaches. Therefore, it is possible to secure a chip thickness and create an environment in which the chip is easily curled above the side wall portion 8 of the protrusion.

  Moreover, as shown in FIG.3 (c), the chip slide part 39 of the insert 31 by 3rd embodiment is the cutting blade 5 and the side wall part 7 of a protrusion part similarly to the insert 21 by 2nd embodiment. Formed in a rake face region sandwiched between the two. And the chip | tip slide part 39 of this embodiment is comprised by the shape different from the insert by 1st and 2nd embodiment. The chip sliding portion 39 is formed to have a plurality of peaks, and the ridge line of the peaks is formed so as to be substantially parallel to the cutting edge 5. As a result, the chips intermittently abut on the plurality of crests of the chip sliding portion 39, thereby generating appropriate friction and impact between the chips and the chip sliding portion 39. It becomes easy to secure the thickness. As a result, chips can be effectively curled by the protrusions 6. Moreover, also in the cutting process when the work material is rich in ductility, the generated chips come into contact with the ridge lines of the plurality of mountain parts, and the entry speed to the protrusions 6 can be effectively reduced. The chip curling action at the protrusion can be enhanced, which is desirable.

  Further, as shown in FIG. 3 (d), the chip sliding portion 49 of the insert 41 according to the fourth embodiment is similar to the insert according to the second and third embodiments, and the side walls of the cutting edge 5 and the protruding portion. It is formed in a rake face region sandwiched between the portions 7. And the chip | tip slide part 49 of this embodiment is comprised by the shape different from the insert by 1st thru | or 3rd embodiment. The chip sliding portion 49 is formed having a plurality of recesses. In the insert 41, the concave portion is formed in a substantially hemispherical shape, but not limited to this, even in other shapes, the maximum height roughness of the chip sliding portion 9 is controlled to the above relationship, Any shape that can create an environment in which the protrusions 6 are easily curled and broken by the protrusion 6 may be used. For example, the bottom surface of the recess may be polygonal.

  In addition, in the cutting process etc. which make the material more rich in ductility etc., it is preferable to form the chip sliding part 9 in the whole region of the area | region pinched by the cutting edge 5 and the top part 7 of a projection part. That is, it is preferable to form the chip sliding portion 9 in the rake face region sandwiched between the cutting edge 5 and the side wall portion 8 of the protrusion and the side wall portion 8 of the protrusion. Thereby, in the rake face region sandwiched between the cutting edge 5 and the side wall part 8 of the protrusion, the cutting speed when curled by the side wall part 8 of the protrusion is effectively reduced by reducing the advancement speed of the chips. It is easy to ensure the thickness of scrap. And in the side wall part 8 of a projection part, while reducing the advancing speed of a chip, also in the processing form where the chip generation directions, such as copying, are not constant, the chip is warped by the side wall part 8 of the projection part, It can prevent riding on the top part 7 of a projection part, and can show the stable chip discharge | emission property. However, if the maximum height roughness is large in the rake face area that is not involved in the chip curl action, that is, in the rake face area other than the area sandwiched between the cutting edge and the top of the protrusion, the protrusion may curl or break. Friction is generated when the chip is brought into contact, which is undesirable because it adversely affects chip discharge.

  As mentioned above, although embodiment of this invention was illustrated, this invention is not limited to embodiment, It cannot be overemphasized that it can be made arbitrary, unless it deviates from the objective of invention.

1 is an overall perspective view of a cutting insert 1 according to a first embodiment of the present invention. It is (a) top view of the cutting insert 1 of FIG. 1, (b) It is a principal part enlarged view. It is a principal part enlarged view (a)-(d) of 1st thru | or 4th embodiment of this invention. It is (a) principal part enlarged view of the cutting insert by 1st embodiment by this invention, (b) AA sectional drawing. It is the comparative example of the cutting insert by 1st embodiment of this invention, (a) principal part enlarged view of the cutting insert 101, (b) AA sectional drawing.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Cutting insert 2 Seating surface 3 Drake surface 4 Relief surface 5 Cutting edge 6 Projection part 7 Top part of projection part 8 Side wall part 9 of a projection part Chip sliding part

Claims (4)

A main body portion formed in a substantially polygonal plate shape, a rake surface formed on the upper surface of the main body portion, a seating surface formed on the lower surface of the main body portion, and a clearance surface formed on the side surface of the main body portion And a cutting edge formed on at least a part of an intersecting ridge line portion between the rake face and the flank face, and a protrusion formed on the rake face with a top corresponding to the cutting edge, In a cutting insert comprising:
Of the rake face, a chip slip portion is formed in at least a part of a region sandwiched between the cutting edge and the top of the projection, and of the rake face, the maximum height roughness in the chip slip portion is A cutting insert characterized by the largest thickness.   The cutting insert according to claim 1, wherein the chip sliding portion is formed to have a plurality of ridges, and a ridge line of the ridges is substantially perpendicular to the cutting edge.   The cutting insert according to claim 1, wherein the chip sliding portion is formed to have a plurality of ridges, and a ridge line of the ridges is substantially parallel to the cutting edge. A cutting tool comprising the cutting insert according to any one of claims 1 to 3.

Images