JP2007283482A - Cutting insert, rotating cutting tool installed with it and cutting method using it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cutting insert capable of reducing cutting resistance, improving strength of a cutting blade positioned at the head end side of a holder and reducing chattering vibration and damage of the cutting blade in machining even in heavy cutting work under a more serious cutting condition. <P>SOLUTION: This cutting insert is constituted by forming a rake face 3 on an upper surface of a main body part, a seating surface 2 on a lower surface, a flank 4 on a side surface and the cutting blade 5 on at least one part of an intersection part of the rake face 3 and the flank 4, and width 6A of a first groove part 6A positioned nearest to one end side out of a plurality of the groove parts 6 formed on the flank 4 so as to reach the rake face 3 is smaller than width 6a of the second groove part 6a adjacent to the first groove part 6A. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a cutting insert used for a turning tool such as a face mill or an end mill.

Conventionally, a rolling tool such as a face mill or an end mill, in particular, a rolling tool having a long cutting edge length and a large number of cutting edges attached thereto is used. Patent Document 1 discloses a cutting insert in which a rake face with respect to a main cutting edge has a positive rake angle while being mounted on a holder, and a flank face is divided by a groove portion together with the main cutting edge. Such a cutting insert is mainly used for heavy cutting with a large amount of chips discharged and a large cutting resistance during cutting. In this case, the main cutting edge is divided into a plurality of divided main cutting edges, so that the chips finely divided in the width direction are discharged. Thus, the cutting resistance at the time of cutting can be reduced by dividing | segmenting the chip | tip discharged | emitted in the width direction small. As a result, it is possible to reduce chatter vibration during processing.
JP 7-299636 A

  Generally, as described above, a cutting tool used for achieving high efficiency is used with a large number of cutting edges attached thereto. By adopting such a configuration, since many cutting edges are simultaneously involved in cutting, fluctuations in cutting force during cutting can be suppressed. As a result, it is possible to reduce deterioration of the finished surface accuracy due to movement of the work material or damage to the cutting insert forming the cutting edge due to the impact due to the fluctuation of the cutting force.

  However, as a recent trend in the machining industry, heavy cutting with a large depth of cut tends to be performed in order to further increase the efficiency of cutting work. Under such severer cutting conditions, the fluctuation of the cutting force at the cutting start stage becomes very large compared to the middle stage of cutting where the fluctuation of the cutting force is small. That is, in the cutting start stage, only the cutting edge portion that is first cut into the work material, that is, only the cutting edge portion that is located on the tip side of the holder becomes the cutting edge that is involved in the cutting. A large impact is applied to the portion due to fluctuations in the cutting force, and a large load is applied.

  Therefore, in the heavy cutting under the severer cutting conditions as described above, with the cutting insert having the conventional configuration, the largest load is applied when contacting the work material, and the cutting is located on the tip side of the holder. There was a problem that the blade portion was insufficient in strength and easily broken.

  The present invention has been made to solve such problems of the prior art, and is a cutting tool, particularly a cutting insert that is used in a cutting tool having a long cutting edge length and a large number of cutting edges attached thereto. In the above, it is an object to provide a cutting insert that reduces cutting resistance, improves the cutting edge strength on the tip side of the holder, and exhibits excellent cutting performance even in severer heavy cutting.

  In order to solve the above problems, a cutting insert according to the present invention includes a main body portion having an upper surface, a lower surface, and a side surface, the main body portion includes a rake face formed on the upper surface of the main body portion, and a side surface of the main body portion. A flank formed on the rake face, a cutting edge formed on at least a part of an intersection of the rake face and the flank, and the rake face so as to divide the cutting edge. A plurality of groove portions, wherein the groove portion has a first groove portion located closest to one end of the cutting edge, and a second groove portion adjacent to the first groove portion, and the main body In the top view of the part, the width of the first groove part is smaller than the width of the second groove part.

  With such a configuration, the cutting edge is constituted by a divided cutting edge divided by a plurality of grooves formed on the flank face, so that the cutting resistance can be reduced by subdividing the chips. Further, when the main body is viewed from above, the width of the first groove is made smaller than the width of the second groove, so that it is positioned on the tip side of the holder where a large load is applied when contacting the work material. The strength of the cutting edge portion to be improved can be improved. Therefore, even in heavy cutting under severer cutting conditions, chatter vibration during processing and chipping of the cutting edge on the holder tip side can be reduced.

  The cutting insert of the present invention includes a main body portion having an upper surface, a lower surface, and a side surface. The main body portion includes a rake face formed on the upper surface of the main body portion and a relief formed on the side surface of the main body portion. A cutting edge formed on at least a part of the intersection of the rake face and the flank, and a plurality of grooves formed on the flank so as to divide the cutting edge. The groove portion has a first groove portion that is positioned closest to one end of the cutting edge, and a second groove portion that is adjacent to the first groove portion. The depth of the first groove portion is smaller than the depth of the second groove portion.

  With such a configuration, the cutting edge is constituted by a divided cutting edge divided by a plurality of grooves formed on the flank face, so that the cutting resistance can be reduced by subdividing the chips. Furthermore, in the top view of the main body portion, the depth of the first groove portion is smaller than the depth of the second groove portion, so that a large load is applied to the holder distal end side where a large load is applied when contacting the work material. The protruding amount of the positioned cutting edge part to the outside of the main body becomes smaller, and the strength of the cutting edge part can be improved. Therefore, even in heavy cutting under severer cutting conditions, chatter vibration during processing and chipping of the cutting edge on the holder tip side can be reduced.

  Furthermore, the cutting insert of the present invention includes a main body portion having an upper surface, a lower surface, and a side surface, and the main body portion includes a rake face formed on the upper surface of the main body portion and a relief formed on the side surface of the main body portion. A cutting edge formed on at least a part of the intersection of the rake face and the flank, and a plurality of grooves formed on the flank so as to reach the rake face so as to divide the cutting edge The groove portion has a first groove portion that is positioned closest to one end of the cutting edge, and a second groove portion that is adjacent to the first groove portion, and in a side view of the main body portion The length of the first groove portion is smaller than the length of the second groove portion.

  With such a configuration, the cutting edge is constituted by a divided cutting edge divided by a plurality of grooves formed on the flank face, so that the cutting resistance can be reduced by subdividing the chips. Furthermore, in the side view of the main body, the length of the first groove is smaller than the length of the second groove, so that a large load is applied to the tip of the holder where a large load is applied when contacting the work material. The strength of the flank in the vicinity of the positioned cutting edge portion can be improved. Therefore, even in heavy cutting under severer cutting conditions, chatter vibration during processing and chipping of the cutting edge on the holder tip side can be reduced.

  The intersecting ridge line between the wall surface of the first groove portion and the rake face has a curved connection portion formed by connecting to the cutting edge at both ends, and the wall surface of the second groove portion and the Since the intersection ridge line with the rake face has a curved connection portion formed by connecting to the cutting edge at both ends, the strength of the connection portion corresponding to the corner portion on the outer periphery of the main body portion is increased. This is desirable because the strength of the cutting edge connected to the connecting portion can be improved.

  Furthermore, the connection part of the first groove part and the connection part of the second groove part have a substantially arc shape, and the connection part close to the other end of the cutting blade of the two connection parts of the first groove part, Of the two connecting portions of the second groove portion, the cutting edge portion positioned between the first groove portion and the second groove portion has a larger radius than the connecting portion adjacent to one end of the cutting blade. Of these, it is desirable because the strength of the cutting edge on one end to which a larger load is applied can be improved.

  Further, the two connecting portions of the first groove portion have a substantially arc shape, and the radius of the connecting portion close to one end of the cutting edge is larger than the radius of the connecting portion close to the other end of the cutting edge. Since it is comprised, it can improve the intensity | strength of the holder front end which requires a big load at the time of contact with a cut material, and since the defect | deletion of a cutting blade can be reduced, it is desirable.

Furthermore, the groove has a central groove formed to reach the central region of the cutting edge,
In the top view of the main body part, the groove part is formed so that the width gradually increases as it goes from the first groove part to the central groove part, as it goes from one end side of the cutting edge to the central region. Corresponding to the reduced load applied to each divided cutting edge, it is desirable because the cutting edge strength of each divided cutting edge can be controlled, and damage to the cutting edge and further the tip can be reduced.

  Further, in the top view of the main body portion, the groove portion is formed so as to gradually increase in depth as it goes from the first groove portion to the central groove portion, so that the central region extends from one end side of the cutting edge. Correspondingly to the load applied to each divided cutting edge that decreases as it goes to, the strength of each divided cutting edge can be suitably controlled, and chipping and cutting insert damage can be reduced and cutting resistance can be reduced. desirable.

  Further, in the side view of the main body portion, the groove portion is formed so as to gradually increase in length from the first groove portion toward the central groove portion. Corresponding to the load applied to each of the divided cutting edges, the strength of the flank portion in the vicinity of each of the divided cutting edges can be controlled to reduce the damage to the chip and increase the holder restraint surface. Therefore, it is desirable because the cutting insert can be attached to the holder more stably.

  Further, the groove portion has a third groove portion that is formed closest to the other end of the cutting edge, and in the top view of the main body portion, the width of the third groove portion is larger than the width of the central groove portion. Even in the case of a cutting insert having a high rake, it is possible to form the third groove portion on the other end side of the cutting edge, so that the strength of the cutting edge portion located on the holder base end side is increased. It is desirable because it can be ensured to reduce cutting resistance and can be applied to severer heavy cutting.

  Furthermore, in the top view of the main body portion, the depth of the third groove portion is smaller than the depth of the central groove portion, so that the third groove portion can be formed on the other end side of the cutting blade. The cutting resistance applied to the cutting insert can be reduced even with a cutting insert having a high rake, and the amount of protrusion of the cutting edge portion located on the other end side of the cutting edge to the outside of the main body can be reduced. It is desirable because the cutting edge strength can be improved by reducing the size.

  Furthermore, in the side view of the main body portion, the length of the third groove portion is smaller than the length of the central groove portion, so that the third groove portion can be further formed on the other end side of the cutting edge. It is possible to reduce the cutting resistance applied to the cutting insert even with a high rake cutting insert, and it is desirable because the strength of the flank portion located on the other end side of the cutting edge can be secured. .

  The cutting insert of the present invention includes a main body portion having an upper surface, a lower surface, and a side surface. The main body portion includes a rake face formed on the upper surface of the main body portion and a relief formed on the side surface of the main body portion. A cutting edge formed on at least a part of the intersection of the rake face and the flank, and a plurality of grooves formed on the flank so as to divide the cutting edge. The groove portion includes a first groove portion that is positioned closest to one end of the cutting edge, and a second groove portion that is adjacent to the first groove portion, and a wall surface of the first groove portion; The intersecting ridge line with the rake face has a curved connecting portion formed by connecting to the cutting edge at both ends, and the intersecting ridge line between the wall surface of the second groove and the rake face is at both ends. Characterized in that it has a curved connecting portion formed by connecting to the cutting edge. It is.

  With such a configuration, the strength of the connecting portion of the first groove portion and the second groove portion is improved, so that the cutting edge strength of the divided cutting edge connected to the first groove portion and the second groove portion can be improved, and the cutting edge is lost. Can be reduced.

  Furthermore, the turning tool of the present invention is characterized by comprising the above-mentioned cutting insert and a holder on which a plurality of the cutting inserts have a positive axial rake.

  With such a configuration, even in heavy cutting under severer cutting conditions, chips can be subdivided to reduce cutting resistance, and the cutting edge strength on the holder tip side can be ensured. It is possible to reduce the vibration and chipping of the cutting edge, provide a machining tool with high machining accuracy and a long life.

  Furthermore, the cutting method of the work material of the present invention comprises the step of rotating the above-mentioned rolling tool to bring the cutting edge close to the work material, and bringing the cutting edge into contact with the surface of the work material. And a step of cutting the work material and a step of retracting the cutting edge from the work material.

  With such a configuration, the cutting edge strength located at the tip of the holder is high, and cutting is performed using a rolling tool that exhibits excellent cutting performance. In addition, a high-quality workpiece can be obtained, and stable machining can be realized for a long time.

  According to the cutting insert of the present invention, the rake face is reached so as to divide the cutting edge, and a plurality of grooves are formed on the flank. Since the width of the one groove portion is formed to be smaller than the width of the second groove portion, cutting resistance can be reduced and the strength of the cutting edge portion positioned on the tip end side of the holder can be secured. Resistant to impact caused by fluctuations in cutting force at the start stage, chatter vibration and chipping of cutting edges can be reduced even in heavy cutting under severer cutting conditions.

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

  1 and 2 show an embodiment of the present invention. FIG. 1 is a plan view of a cutting insert (hereinafter abbreviated as an insert) 1 according to a first embodiment of the invention, FIG. ) Long side view. 2A is a plan view of the insert 21 according to the second embodiment, and FIG. 2B is a side view of the long side. FIG. 3 is an overall perspective view of a rolling tool using the insert of the present invention.

  Further, FIG. 4 is an enlarged view of a main part of FIG. 1A for explaining a groove shape of the insert 1 according to the first embodiment shown in FIG.

  5A is a plan view of the insert 31 according to the third embodiment of the invention, and FIG. 5B is a side view of the long side.

  1, the insert 1 according to the first embodiment includes a seating surface 2 on the lower surface of the main body, a rake surface 3 on the upper surface, and a relief surface 4 on the side surface. And the cutting edge 5 is formed in the crossing part of the rake face 3 and the flank 4, and at least one part of the substantially polygonal side. In the present embodiment, the main body has a polygonal plate shape, more specifically, a parallelogram plate shape.

  Here, the flank 4 is provided with a plurality of grooves 6 that reach the rake face 3 side by side. As shown in FIGS. 1 (a) and 1 (b), the groove 6 has a first groove 6A that is formed closest to one end of one side of a substantially polygon where the cutting edge 5 is formed; The second groove 6a is formed adjacent to the first groove 6A. As shown in FIG. 1A, the cutting edge 5 is divided into a plurality of divided cutting edges 5 </ b> A by these groove portions 6.

  FIG. 3 is an overall perspective view of the rolling tool 11 to which the insert 1 according to the first embodiment of the present invention is mounted. Here, the insert 1 is mounted on the holder 12 so that the cutting tool 11 has a positive axial rake in a state where the insert is mounted. As described above, in general, in a cutting tool, particularly a cutting tool used for heavy cutting, a plurality of cutting edges simultaneously cut into contact with a work material during cutting in order to reduce cutting resistance during processing. It is configured not to go. That is, a plurality of cutting blades are arranged in a spiral shape along the axial direction of the rolling tool 11 so that the cutting blades sequentially come into contact with the work material and cut from the holder tip side portion. . With a rolling tool having such a configuration, by simultaneously increasing the number of cutting edges involved in cutting, fluctuations in cutting force at the time of cutting are suppressed, and the impact due to fluctuations in cutting force at the time of cutting is reduced. It is possible to prevent the cutting material from being moved, the cutting insert from being damaged, and the finished surface accuracy from being lowered.

  However, as described above, in the cutting start stage, only the cutting edge portion that comes into contact with the work material first and cuts, that is, only the cutting edge portion on the tip side of the holder is involved in the cutting. Therefore, the impact and load due to the fluctuation of the cutting force are greatly applied to the holder tip side cutting edge portion. On the other hand, since the cutting force due to the cutting edge portion on the tip side of the holder has already occurred in the other cutting edge portions that are subsequently cut into the work material, the variation in the cutting force becomes smaller. Therefore, the fluctuations in the cutting force applied to the other cutting edge portions that are sequentially cut into the work material are gradually reduced, and the impact and load applied correspondingly are also reduced. Therefore, under severe cutting conditions such as heavy cutting, a large load is applied to any cutting edge portion when cutting into the work material, but the load applied to each cutting edge portion of the insert is relatively low. The cutting edge portion that cuts faster into the material becomes larger.

Therefore, as shown in FIGS. 1A and 1B, the insert 1 according to the present invention includes a first groove portion 6 </ b> A among the groove portions 6 arranged in parallel on the relief surface 4 in a top view of the main body portion. The width W _6A is smaller than the width W _6a of the second groove 6a. As a result, the width W _6A of the first groove 6A formed in the cutting edge portion of the holder tip side, which is first contacted and cut into the work material at the time of cutting and is subjected to the largest load, is the second groove 6a provided adjacently. The width _W6a is smaller than the width _W6a . Therefore, it is possible to secure the length of the cutting edge portion of the holder that is subjected to the greatest load when contacting the work material, and to improve the cutting edge strength of the cutting edge portion.

  For this reason, conventionally, even if the strength of the center portion of the cutting edge is large, the largest load is applied at the cutting start stage. Even in heavy cutting under severer cutting conditions that tend to occur, the strength of the entire cutting edge, that is, the strength of the cutting insert itself can be increased, and in particular, the strength of the cutting edge of the holder tip side can be improved. , Cutting edge defects can be reduced.

  Further, the cutting edge 5 is constituted by a divided cutting edge 5 </ b> A that is divided by a plurality of grooves 6 arranged in parallel on the flank 4. Thereby, the chip | tip discharged | emitted can be subdivided in the width direction, and cutting resistance can be reduced. As a result, chatter vibration and cutting edge defects during machining can be reduced, excellent finished surface accuracy can be obtained, and the tool life can be extended.

Furthermore, since the width W _6A of the first channel section 6A is formed smaller than the second groove width W _6a, the one end portion of the cutting edge 5, conventional, even in a region which could not be formed a groove The first groove 6A can be formed. As a result, the strength of the cutting edge of the holder that is subjected to the greatest load when cutting into the work material can be secured, and the cutting resistance can be further reduced. Therefore, excellent cutting performance can be achieved even under severer cutting conditions. Can be demonstrated.

Here, as the width of each of the first groove 6A and the second groove 6a, when the maximum dimension in the direction substantially parallel to the width W of the insert 1 (the dimension in the longitudinal direction of the insert) is w. 0.01w to 0.10w, more preferably 0.04w to 0.08w. The difference in width between the first groove 6A and the second groove 6a is desirably 0.01 w or more. For example, in the case of an insert having a longitudinal dimension w of 25 mm, the width W _6A of the first groove _6A is preferably 1.2 mm, and the width W _6a of the second groove _6a is preferably 1.6 mm. Thereby, an above-described effect can be improved.

Furthermore, as illustrated in FIGS. 1 (a) and (b), the insert 1, in a top view of the body portion, the depth D _6A of the first groove section 6A, than the depth D _6a of the second groove portion 6a Is also formed small. This suppresses an increase in the protruding amount of the cutting edge portion protruding outward from the wall surface 7 of the groove portion, and further improves the strength of the cutting edge portion of the holder tip side, effectively reducing chipping. can do.

Here, as the depth of each of the first groove 6A and the second groove 6a, the maximum dimension in the direction substantially parallel to the direction of the depth D of the insert 1 (the dimension in the width direction of the insert) is d. In this case, 0.01d to 0.10d, more preferably 0.04d to 0.08d. The difference in width between the first groove 6A and the second groove 6a is preferably 0.02d or more. For example, in the case of an insert having a dimension d in the width direction of the insert of 15.88 mm, the depth D _6A of the first groove _6A is 0.8 mm, and the depth D _6a of the second groove _6a is 1.2 mm. Is good. Thereby, an above-described effect can be improved.

  In addition, by forming the first groove portion and the second groove portion so that both the width and the depth of the first groove portion and the second groove portion have the above-described relationship, the amount of protrusion of the holder tip side cutting edge portion can be reduced. While making it small, the cutting edge length can be secured. Therefore, the cutting edge strength is high, the area of the rake face 3 of the entire insert is widened, and the effect of reducing chipping of the cutting edge is further enhanced.

Furthermore, as illustrated in FIGS. 1A and 1B, the insert 1 has a length L _6A of the first groove 6A that is longer than a length L _6a of the second groove 6a in a side view of the main body. It is formed small. Thereby, the intensity | strength of the holder front end side cutting edge part can be enlarged. In particular, the first groove 6 </ b> A is formed on the flank 4 so as not to reach the seating surface 2. That is, since the end of the first groove 6A does not reach the seating surface 2, the flank 4 is not divided by the first groove 6A. Therefore, the strength of the flank 4 can be increased in the vicinity of the holder tip side cutting edge portion. As a result, since the cutting edge strength and the toughness of the entire insert can be increased, damage to the insert can be reduced. Further, along with the improvement in strength of the flank 4 near the cutting edge on the holder tip side, flank wear can be reduced. Furthermore, since the flank 4 becomes wider, the restraint surface for restraining the insert is increased, and the insert can be mounted on the holder more stably.

Here, as the length of each of the first groove 6A and the second groove 6a, the maximum dimension in the direction substantially parallel to the length L direction of the insert 1 (the dimension in the thickness direction of the insert) is l. In such a case, 0.01 l to 0.10 l, more preferably 0.04 l to 0.08 l is preferable. The difference in width between the first groove 6A and the second groove 6a is preferably 0.02 l or more. For example, in the case of an insert having a dimension 1 in the thickness direction of the insert of 6.35 mm, the length L _6A of the first groove _6A is 3.0 mm, and the length L _6a of the second groove _6a is 4.5 mm. Is good. Thereby, an above-described effect can be improved.

  In addition, in the 1st groove part and the 2nd groove part which have the above-mentioned relationship about the width | variety and depth of a groove part, it is set as the structure which has the relationship about the length of the groove part mentioned above, and cutting edge strength And the strength of the entire insert, and further, the flank strength can be improved, so that the progression of small chipping to chipping of the cutting edge can be reduced. As a result, the cutting performance can be further improved, and the finished surface accuracy can be improved even under more severe cutting conditions.

  Further, by forming the first groove portion and the second groove portion so that the depth and length of the first groove portion and the second groove portion have the relationship as described above, the material has a cutting function of chips and a work material. Interference can be reduced. As a result, cutting resistance can be reduced, and excellent chip discharge performance can be exhibited.

  The width W of each groove in the top view of the main body is the dimension of the groove in the longitudinal direction of the insert 1 as shown in FIG. That is, in the top view of the main body (when the upper surface of the insert is projected onto a surface parallel to the seating surface 2), the intersection between the wall surface 7 of the groove portion and the rake surface 3 and the virtual straight line of the cutting edge 5 It is the distance between intersections.

  Further, in the top view of the main body portion, the depth D of each groove portion is a dimension of the groove portion in the width direction of the insert 1 as illustrated in FIG. That is, in the top view of the main body (when the upper surface of the insert is projected onto a surface parallel to the seating surface 2), the width from the intersection of the wall surface 7 of the groove and the rake surface 3 to the virtual straight line of the cutting edge 5 It is the distance in the direction (direction perpendicular to the cutting edge 5). Here, the wall surface 7 of the groove portion refers to a series of surfaces connected to the rake face 3 and the flank face 4.

  Furthermore, in the side view of the main body, the length L of each groove is a dimension of the groove in the thickness direction of the insert 1 as illustrated in FIG. That is, in the side view of the main body (when the side of the insert is projected onto a surface perpendicular to the seating surface 2), the shortest distance from one end of the groove, that is, the rake face 3, to the other end of each groove. is there.

Further, the insert 1 is formed with a plurality of groove portions 6 such that the width W increases from the first groove portion 6A toward the central groove portion 6B formed to reach the central region of one side of the substantially polygonal shape. . That is, the load applied to each of the divided cutting edges 5A when cutting into the work material is gradually reduced according to the order of contact with the work material, but the width W of the groove 6 is positioned on the holder front end side accordingly. The first groove 6A is formed so as to gradually increase from the center groove 6B. That is, the width _{W 6B} of the center groove 6B is large, the first channel section 6A is formed so that the width _{W 6A} decreases. Thereby, the cutting edge length corresponding to each cutting edge portion can be secured to ensure the strength of each cutting edge, and the cutting resistance can be reduced by subdividing discharged chips.

  Further, the depth D of each groove 6 is formed so as to gradually increase from the first groove 6A toward the central groove 6B in a top view of the main body. Thereby, in response to the load applied to each of the divided cutting edges 5A, the amount of the cutting edge protruding from the wall surface 7 of the groove portion to the outside of the insert is suppressed to ensure the cutting edge strength, and cutting by fragmentation of chips. The resistance can be reduced. Therefore, it is possible to achieve both reduction of chipping of the cutting edge and improvement of chip discharging property.

  Furthermore, in the side view of the main body, the length L of each groove 6 is formed so as to gradually increase from the first groove 6A toward the central groove 6B. Thereby, while being able to control the intensity | strength of each cutting blade part according to the magnitude | size of the load concerning each cutting blade part, flank strength can be improved. As a result, it is possible to further reduce cutting edge defects and improve chip discharge performance.

Further, the width W _6C of the third groove 6C formed closest to the other end of one side of the substantially polygonal shape is formed to be smaller than the width W _6B of the central groove 6B. Thereby, when the groove part with the large width W is formed, the cutting edge length becomes small, and the third groove part 6C can be formed also in the cutting edge part where the strength of the cutting edge is insufficient and is easily lost. In particular, the third groove portion 6C can be formed in a cutting edge portion formed in a portion having a small insert thickness, such as a cutting edge portion located on the holder base end side of the insert having a high rake. That is, a groove can be formed on the other end side of the cutting edge. Therefore, the cutting edge strength of the insert can be ensured and the cutting resistance can be further reduced. Therefore, even in heavy cutting processing where a higher cutting resistance is applied, chatter vibration during cutting and chipping of the cutting edge are eliminated. Can be reduced.

Furthermore, the depth D _6C of the third groove _6C is formed to be smaller than the depth D _6B of the central groove 6B in a top view of the main body. In addition, the length L _6C of the third groove _6C is formed to be smaller than the length L _6B of the central groove 6B in a top view of the main body.

  Accordingly, since the third groove portion 6C is formed smaller than the central groove portion 6B, the third groove portion is conventionally formed on the cutting edge portion where the strength of the cutting edge is insufficient and it is difficult to form the groove portion. 6C can be provided. Therefore, even with an insert having a high rake, the cutting resistance can be further reduced without reducing the cutting edge strength, so that chatter vibration and chipping of the cutting edge can be reduced even under severer cutting conditions. .

In particular, since the length L _6C the third groove portion 6C is formed to be smaller than the length L _6B of the central groove 6B, since the other end of the third groove portion 6C on flank 4 located, the entire insert Strength and toughness are increased. Therefore, flank wear can be reduced.

On the other hand, the depth D _6C of the third groove portion 6C is, by being formed to be smaller than the depth L _6B of the central groove 6B, it is possible to reduce the amount of protrusion of the cutting edge of the third groove portion 6C portion, The cutting edge strength of the part can be improved.

  Further, the insert 1 according to the present embodiment has a curved connecting portion 8A formed by connecting the cutting edge 5 at both ends of the intersecting ridge line between the wall surface 7A of the first groove portion 6A and the rake face 3. Become. And the intersection ridgeline of the wall surface 7a of the 2nd groove part 6a and the rake face 3a has the curved connection part 8a formed by connecting to the cutting edge 5 at both ends. By setting it as such a structure, since the intensity | strength of the connection part corresponded to a corner | angular part in the outer periphery of a main-body part increases, the improvement of the cutting-blade strength connected to a connection part can be aimed at.

Furthermore, the connection portion 8A of the first groove portion 6A and the connection portion 8a of the second groove portion 6a are formed to have a substantially arc shape. Forming the connecting portion 8 so as to have a substantially arc shape is effective in reducing stress concentration. And when connection part 8A, 8a of 1st groove part 6A and 6a is formed in a substantially circular arc shape in this way, connection part 8A which adjoins the other end of cutting blade 5 among two connection parts of 1st groove part 6A. _2, it is desirable that the have a larger radius than the connecting portion 8a ₁ adjacent to two end of the out cutting edge 5 of the connecting portion of the second groove portion 6a. That is, as shown in FIG. 4, the radius RA ₂ of the connection portion 8A ₂ of the first groove portion 6A is formed so as not to be larger than the radius Ra ₁ of the connection portion 8a ₁ of the second groove portion 6a (; RA ₂ > Ra ₁ ) is desirable. Thereby, among the cutting edge portions 5A ′ positioned between the first groove 6A and the second groove 6a, it is possible to improve the cutting edge strength on one end side where a larger load is applied.

Here, the radius of the connecting portion 8a ₂ connecting portions 8A ₂ and the second groove portion 6a of the first channel section 6A, both 0.01D～0.05D, more preferably, a 0.02w~0.04w It is preferable. Within this range, RA ₂ and Ra ₁ may be configured to have the above magnitude relationship. For example, as described above, when the insert is 15.88 mm, it is preferable that RA ₂ is 0.4 mm and Ra ₁ is 0.35 mm.

Further, the two connecting portions 8A ₁ and 8A ₂ of the first groove portion 6A have a radius RA ₁ of the connecting portion 8A ₁ close to one end of the cutting edge 5 and the connecting portion 8A ₂ close to the other end of the cutting edge 5. it is better to become configured to be greater than the radius RA _2. That is, as shown in FIG. 4, the radius RA ₁ of the connection portion 8A ₁ of the first groove portion 6A is formed to be larger than the radius RA ₂ of the connection portion 8A ₂ of the first groove portion 6A (; RA ₁ > RA ₂ ) is desirable. As a result, it is possible to improve the cutting edge strength of the cutting edge portion 5A ″ located on the tip side of the holder where a large load is applied when contacting the work material. Therefore, it is possible to reduce chipping of the cutting edge.

Here, the radius of the connecting portion 8A ₂ connecting portions 8A ₁ and the first groove portion 8A of the first groove portion 6A, as in the above-connecting portion, both 0.01D～0.015D, more preferably, 0. It is preferable to set it as 02d-0.04d. Within this range, RA ₁ and RA ₂ may be configured to have the above magnitude relationship. For example, as described above, when w is 25 mm and RA ₂ is 0.4 mm, RA ₁ is preferably 0.45 mm.

  Here, the radius R of the connecting portion 8 is a radius of a curved line having a substantially arc shape in a top view as shown in FIG. Moreover, in this embodiment, although the connection part 6 formed what was formed by one circular arc, not only this but the connection part 8 may have a some circular arc. In the case of the connecting portion 8 having a plurality of arcs as described above, the radius R of the connecting portion 8 is the maximum radius among the radii of the plurality of arcs.

  Next, the insert 21 according to the second embodiment of the present invention will be described with reference to FIG. In addition, about the structure same as the insert 1 by 1st embodiment here, the same code | symbol is attached | subjected and description is abbreviate | omitted.

  As illustrated in FIGS. 2A and 2B, the insert 21 is formed with a third groove 6C having the same configuration as the central groove 6B. That is, the third groove 6 </ b> C is formed so as to reach the rake face 3 and reach the seating face 2. Even if it is such a structure, while improving the intensity | strength of the holder front end side cutting edge part to which the largest load is cut | disconnected in a cut material among the cutting edges 5, cutting resistance can be reduced. Therefore, chatter vibration at the cutting start stage and chipping of the cutting edge can be reduced.

  Note that, under heavy cutting conditions such as heavy cutting with a particularly large cutting depth, the other end side of the cutting edge, that is, the holder base end side cutting edge part portion, like the insert 1 according to the first embodiment. It is desirable to use an insert in which the third groove 6C is formed. As a result, the cutting resistance can be effectively reduced even under severer cutting conditions, and chatter vibration and cutting edge defects can be reduced at the cutting start stage and the cutting middle stage.

  Moreover, the groove part 6 formed in the insert 21 by 2nd embodiment is formed so that the length L of a groove part may become large gradually in the top view of a main-body part as it goes to the center groove part 6B from 6A of 1st groove parts. In the insert 1 according to the first embodiment, the groove portion 6 formed adjacent to the second groove portion 6a has the same configuration as the central groove portion 6B. However, as in this embodiment, in the top view of the main body portion, You may form groove part (6 ') adjacent to the 2nd groove part 6a so that the length L of a groove part may become larger than the length of the 2nd groove part 6a. With such a configuration, the strength of each cutting edge can be improved from the central region of the cutting edge toward the holder tip side cutting edge where the load applied to the cutting start step gradually increases, thereby reducing chipping. be able to.

  Furthermore, the length L of the groove portion formed between the second groove portion 6a and the central groove portion 6B may be formed with different lengths L (not shown) so as to gradually increase. In addition, although this embodiment demonstrated the groove part from which the length L differs, you may form so that the width W and the depth D of a groove part may become large similarly.

  Next, an insert 31 according to a third embodiment of the present invention will be described with reference to FIG. In addition, about the structure same as the insert 1 by 1st embodiment here, the same code | symbol is attached | subjected and description is abbreviate | omitted.

  As shown in FIGS. 5A and 5B, the insert 31 has the longest divided cutting edge 5A ″ located on one end side of the cutting edge 5 among the plurality of divided cutting edges 5A divided by the groove 6. With such a configuration, it is possible to improve the cutting edge strength of the cutting edge portion of the holder tip side while reducing the decrease in cutting edge strength due to the formation of the first groove 6A. Therefore, chipping of the cutting edge can be reduced even under more severe cutting conditions, and as a result, cutting can be performed under more severe cutting conditions, and cutting efficiency can be improved. In this case, machining accuracy can be improved and stable cutting can be performed for a long time.

  Here, FIGS. 1, 2, and 5 exemplify the insert 1 and the insert 21 in which the main body has a parallelogram plate shape, but as another embodiment of the present invention, the main body corresponds to the holder shape. It goes without saying that the same effect can be obtained even when the plate is formed in a square plate shape, a rhombus plate shape, or the like. Furthermore, the shape is not limited to a polygonal plate shape, and a circular shape or other special shape can also be used.

  Furthermore, although the shape of each groove part illustrated the embodiment formed so that all of width W, depth D, and length L may become gradually large toward the center groove part 6B from the 1st groove part 6A, However, the width W, the depth D, and the length L of each groove 6 may be the same. The same applies to the relationship between the central groove 6B and the third groove 6C. The magnitude relationship of all the elements may not have the above-described relationship.

Furthermore, although the embodiment satisfying any relationship of RA ₂ > Ra ₁ and RA ₁ > RA ₂ is illustrated for the magnitude relationship between the connecting portions of the first groove 6A and the second groove 6a, Only one of the magnitude relationships may be satisfied. For example, RA ₁ > RA ₂ of the first groove 6A has a relationship, and the connecting portions of the other grooves including the second groove 6a are configured to have an arc shape having the same radius as RA _2. Also good. Even in such a configuration, it is possible to improve the strength of the cutting edge located on the holder front end side.

  In addition, the effect of the present invention can be obtained even if the groove 6 is not formed over the entire cutting edge. However, in order to reduce the cutting resistance more effectively, the groove 6 is cut as in this embodiment. It is desirable to form over the entire blade.

  Furthermore, at least one protrusion may be formed corresponding to the divided cutting edge 5A in order to improve chip discharge.

  Finally, the cutting method of the work material which concerns on this invention is demonstrated. First, the insert 1 according to the present invention is attached to the holder 12 to obtain a rolling tool 11. Then, the rolling tool 11 is rotated to bring the rolling tool 11 closer to the work material. The rolling tool 11 and the work material may be relatively close to each other. For example, the work material may be brought close to the rolling tool 11.

  Thereafter, the cutting edge 5 of the insert 1 mounted on the rolling tool 11 is brought into contact with the surface of the work material to cut the work material. After finishing the necessary amount of cutting, the rolling tool 11 is separated from the work material.

  Thus, since the cutting method of the work material which concerns on this invention has the insert 1 which concerns on this invention, it can exhibit the outstanding finished surface precision also in the cutting process on severer cutting conditions. Therefore, the cutting efficiency can be improved. In particular, as described above, by cutting a work material using a rolling tool in which a plurality of inserts according to the present invention are mounted on a holder, a cutting tool exhibiting high cutting edge strength can be used under more severe cutting conditions. Can be cut. And in severer cutting conditions, for example, in heavy cutting such as high feed processing, chip disposal becomes an important issue for improving the cutting efficiency. Since it can be subdivided in the direction, it is possible to improve the discharge performance of chips having a large thickness. As a result, the volume of the generated chips can be reduced, and the working efficiency can be improved.

  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.

It is (a) top view of the cutting insert by 1st embodiment of this invention, (b) Long side side view. It is the (a) top view and (b) long side side view of the cutting insert by 2nd embodiment of this invention. It is a whole perspective view of the turning tool using the throw away insert of the present invention. It is a principal part enlarged view of Fig.1 (a) for demonstrating the groove part shape of the insert 1 by 1st embodiment shown in FIG. It is the (a) top view and (b) long side side view of the cutting insert by 3rd embodiment of this invention.

Explanation of symbols

1 Cutting insert (insert)
2 Seating surface 3 Rake face 4 Flank 5 Cutting edge 5A Divided cutting edge 6 Groove 6A First groove 6a Second groove 6B Central groove 6C Third groove 7 Groove wall 8 Groove connection 11 Rolling tool 12 Holder 21 Cutting Insert W: Groove width D: Groove depth L: Groove length w: Insert width d: Insert depth l: Insert length

Claims (20)

A main body having an upper surface, a lower surface and side surfaces;
The main body includes a rake surface formed on the upper surface of the main body, a flank formed on a side surface of the main body, and a cut formed on at least a part of an intersection of the rake surface and the flank. A blade and a groove formed on the flank so as to reach the rake face so as to divide the cutting edge.
The groove has a first groove located closest to one end of the cutting edge, and a second groove adjacent to the first groove,
A cutting insert in which the width of the first groove portion is smaller than the width of the second groove portion in a top view of the main body portion.   The cutting insert according to claim 1, wherein a depth of the first groove portion is smaller than a depth of the second groove portion in a top view of the main body portion.   The cutting insert according to claim 1 or 2, wherein the length of the first groove portion is smaller than the length of the second groove portion in a side view of the main body portion. A main body having an upper surface, a lower surface and side surfaces;
The main body includes a rake surface formed on the upper surface of the main body, a flank formed on a side surface of the main body, and a cut formed on at least a part of an intersection of the rake surface and the flank. A blade and a groove formed on the flank so as to reach the rake face so as to divide the cutting edge.
The groove has a first groove located closest to one end of the cutting edge, and a second groove adjacent to the first groove,
The cutting insert in which the depth of the first groove portion is smaller than the depth of the second groove portion in a top view of the main body portion.   The cutting insert according to claim 4, wherein the length of the first groove portion is smaller than the length of the second groove portion in a side view of the main body portion. A main body having an upper surface, a lower surface and side surfaces;
The main body includes a rake surface formed on the upper surface of the main body, a flank formed on a side surface of the main body, and a cut formed on at least a part of an intersection of the rake surface and the flank. A blade and a groove formed on the flank so as to reach the rake face so as to divide the cutting edge.
The groove has a first groove located closest to one end of the cutting edge, and a second groove adjacent to the first groove,
A cutting insert in which the length of the first groove portion is smaller than the length of the second groove portion in a side view of the main body portion. The intersecting ridge line between the wall surface of the first groove and the rake face has curved connection portions formed by connecting to the cutting edge at both ends,
The cutting insert according to any one of claims 1 to 6, wherein the intersecting ridge line between the wall surface of the second groove portion and the rake face has a curved connection portion formed at both ends connected to the cutting edge. The connection part of the first groove part and the connection part of the second groove part have a substantially arc shape,
Of the two connection parts of the first groove part, the connection part close to the other end of the cutting edge has a larger radius than the connection part close to one end of the cutting edge of the two connection parts of the second groove part. The cutting insert according to claim 7.   The two connecting portions of the first groove portion are substantially arc-shaped, and the radius of the connecting portion close to one end of the cutting edge is larger than the radius of the connecting portion close to the other end of the cutting edge. The cutting insert according to claim 7 or 8, wherein: The groove has a central groove formed to reach the central region of the cutting edge,
The cutting insert according to any one of claims 1 to 9, wherein in the top view of the main body portion, the groove portion is formed such that the width gradually increases from the first groove portion toward the central groove portion.   The cutting insert according to any one of claims 1 to 10, wherein the groove portion is formed so that the depth gradually increases from the first groove portion toward the central groove portion in a top view of the main body portion.   The cutting insert according to any one of claims 1 to 11, wherein in the side view of the main body portion, the groove portion is formed such that the length gradually increases from the first groove portion toward the central groove portion. The groove has a third groove formed closest to the other end of the cutting edge,
The cutting insert according to any one of claims 1 to 12, wherein a width of the third groove portion is smaller than a width of the central groove portion in a top view of the main body portion.   The cutting insert according to claim 13, wherein the depth of the third groove portion is smaller than the depth of the central groove portion in a top view of the main body portion.   The cutting insert according to claim 13 or 14, wherein the length of the third groove portion is smaller than the length of the central groove portion in a side view of the main body portion. A main body having an upper surface, a lower surface and side surfaces;
The main body includes a rake surface formed on the upper surface of the main body, a flank formed on a side surface of the main body, and a cut formed on at least a part of an intersection of the rake surface and the flank. A blade and a groove formed on the flank so as to reach the rake face so as to divide the cutting edge.
The groove has a first groove located closest to one end of the cutting edge, and a second groove adjacent to the first groove,
The intersecting ridge line between the wall surface of the first groove and the rake face has curved connection portions formed by connecting to the cutting edge at both ends,
The cutting ridge line which has the curved connection part formed by connecting the wall surface of the said 2nd groove part and the said rake face to the said cutting edge at both ends. The connection part of the first groove part and the connection part of the second groove part have a substantially arc shape,
Of the two connecting parts of the first groove part, the connecting part close to the other end of the cutting edge has a larger radius than the connecting part close to one end of the cutting edge of the two connecting parts of the second groove part. The cutting insert according to claim 16.   The two connecting portions of the first groove portion are substantially arc-shaped, and the radius of the connecting portion close to one end of the cutting edge is larger than the radius of the connecting portion close to the other end of the cutting edge. The cutting insert according to claim 16 or 17, wherein:   A cutting tool comprising: the cutting insert according to claim 1; and a holder on which a plurality of the cutting inserts have a positive axial rake. Rotating the rolling tool according to claim 19, and bringing the cutting edge close to the work material;
Contacting the cutting edge with the surface of the work material and cutting the work material;
Retracting the cutting edge from the work material;
A method for cutting a work material comprising:

Images