JP2008284666A - Cutting insert - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To dispose of cutting chips smoothly and stably from finish cutting to rough cutting in a cutting insert with a convenient side, which is provided with a breaker groove. <P>SOLUTION: In this cutting insert, a cutting blade 5 extended from a corner section 4 is formed in one of a pair of side ridge sections crossing the corner section 4 of a rake face 2. In this rake face 2, the breaker groove 6 with a groove bottom face 6a continuous to the cutting blade 5 and a groove wall face 6b rising from this groove bottom face 6a while facing the cutting blade 5 side is formed to be extended along the cutting blade 5 from the corner section 4. In this breaker groove 6, a plurality of steps of wall sections 8a, 9a, 6b extended to a direction in which the cutting blade 5 is extended from the corner section 4 side while facing the cutting blade 5 side are formed in order toward the direction in which the other side ridge section is extended from the corner section 4 to increase height relative to the groove bottom face 6a and length along the direction in which the cutting blade 5 is extended. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention is a cutting insert having one or more cutting blades that are mounted on a cutting holder and perform cutting, and intersects a corner portion of a rake face so as to improve chip disposal in a cutting feed direction. A cutting blade extending from the corner portion is formed on one of the pair of side ridge portions of the rake face, and a breaker groove extending from the corner portion along the cutting edge is formed on the rake face. It relates to a cutting insert with a so-called option.

As such a cutting insert with a hand, for example, in Patent Document 1, a chip breaker is formed by joining an ultra-high hardness sintered body to the upper surface of a corner. Proposals have been made in which a breaker is processed by wire electric discharge machining, electric discharge machining or polishing.
JP-A-8-118113

  However, in the cutting insert with a hand described in this Patent Document 1, since the chip breaker is only formed from the groove bottom surface connected to the cutting edge and the groove wall surface rising from the groove bottom surface, Depending on the width of the breaker to the wall surface, the radius of curvature of the groove wall surface, the height with respect to the groove bottom surface, etc., when the cutting is small in finish cutting etc. and cutting is performed only at the corner part side of the cutting edge, the width is generated small. However, if the cutting is performed with a cutting edge from the corner to the almost full length of the chip breaker by rough cutting etc., it will be generated wide. There is a risk that the chips will be clogged.

  In addition, this Patent Document 1 also describes a two-stage breaker in which the groove wall surface is formed in two stages in a double edged edge sharpened breaker in which cutting edges are formed on both of a pair of side ridges intersecting the corner part. Has been. However, in such a cutting insert, since it is not with a hand, it becomes difficult to make the chip | tip produced | generated only by the corner part side collide with a groove wall surface, and the process becomes difficult. On the other hand, since the two-step groove wall surface extends over the entire length of the chip breaker, even when cutting with the entire length of the cutting edge, wide chips collide with both of the two-step groove wall surfaces. There is a risk of increasing cutting resistance.

  The present invention has been made under such a background, and in a cutting insert with a hand that is formed with a breaker groove as described above, the entire length is used from the finish cutting in which the corner side of the cutting edge is used. An object of the present invention is to provide a cutting insert capable of smoothly and stably treating chips up to rough cutting.

  In order to solve the above problems and achieve such an object, the present invention provides a cutting blade extending from the corner portion on one side ridge portion of a pair of side ridge portions intersecting the corner portion of the rake face. A breaker groove having a groove bottom surface continuous with the cutting edge and a groove wall surface rising from the groove bottom surface toward the cutting edge side extends from the corner portion along the cutting edge. In this breaker groove, a plurality of steps of wall portions extending from the corner portion side toward the direction in which the cutting blade extends are directed from the corner portion to the pair of sides. It is formed so that the length along the direction in which the above-mentioned cutting edge extends becomes long so that the height with respect to the above-mentioned groove bottom becomes high in order toward the direction in which the other side ridge part extends among the ridges. It is characterized by that.

  Therefore, in such a cutting insert, chips generated on the corner portion side of the cutting edge in finish cutting or the like are reliably guided from the groove bottom surface of the breaker groove connected to the cutting edge to the groove wall surface, and the other side. It flows out in the direction in which the ridges extend. Further, on the corner portion side of the breaker groove, a plurality of stepped wall portions having heights with respect to the groove bottom surface in order toward the direction in which the other side ridge portion extends from the corner portion, respectively face the cutting edge side. Since the cutting edge extends in the direction in which the cutting edge extends from the corner side, the outflowing chips are sequentially collided with these wall portions to receive resistance, and are securely curled and processed. .

  On the other hand, as the depth of cut increases from such finish cutting to rough cutting, the width of the chips generated by the cutting edge also increases. It is also formed so that the length along the direction in which the cutting edge extends is increased in order toward the direction in which the side ridge extends, so that the wall portion reliably collides with the portion where the width of the chip is increased. Can be processed. Moreover, since the number of steps of the wall that collides with the chips generated in this way is smaller on the side away from the corner than on the corner, the cutting resistance does not increase unnecessarily, and the chips are clogged. Can also be prevented.

  Here, a concave portion recessed with respect to the groove bottom surface is formed on the groove bottom surface of the breaker groove on the corner portion side, and the cutting blade extends in the direction in which the cutting blade extends from the corner portion side on the groove wall surface of the breaker groove. A ridge portion extending longer than the concave portion toward the inner wall surface facing the cutting edge side of the concave portion, and a wall surface facing the cutting blade side of the ridge portion, and the plurality of wall portions By doing so, it becomes possible to process chips more smoothly and efficiently in all the incision regions from finish cutting to rough cutting as described above.

  In other words, by forming a recess on the corner side of the groove bottom surface of the breaker groove and a protrusion extending from the corner side longer than the recess on the groove wall surface, the corner of the cutting edge can be used in finish cutting or the like. The small chips generated on the part side first flow into the recess and collide with the inner wall surface facing the cutting edge of the recess where the height of the breaker groove with respect to the groove bottom is negative. Next, the chips run up from the recess to the groove wall surface of the breaker groove, collide with the wall surface of the ridge portion whose height relative to the groove bottom surface is higher than the recess, receive resistance, and are curled more reliably.

  On the other hand, wide chips generated by the substantially full length of the cutting edge in rough cutting etc. flow out along the groove bottom surface of the breaker groove as a whole, so the portion on the corner side rarely flows into the recess, As it is, it runs up the groove wall surface of the breaker groove and collides with the wall surface of the ridge. Therefore, since there is no resistance due to the inner wall surface of the recess, no large resistance acts on the chips, so that it is possible to reliably suppress an increase in cutting resistance and effectively clog the chips. It becomes possible to prevent.

  However, when the cutting insert is exclusively used for such rough cutting, as described above, the groove bottom surface is formed as a continuous surface without providing a recess at the corner side of the groove bottom surface of the breaker groove. In the groove wall surface of the breaker groove, only the ridge portion extending shorter than the groove wall surface in the direction in which the cutting edge extends from the corner side is formed at a position where the height relative to the groove bottom surface is lower than the groove wall surface, A wall surface facing the cutting edge side of the ridge portion and a portion of the groove wall surface that is higher in height with respect to the groove bottom surface than the ridge portion may be used as the multi-stage wall portion. In this case, when wide chips are generated, an increase in cutting resistance and chip clogging can be reliably prevented in the same manner as described above. On the other hand, even when used for finishing cutting, The generated chips can be treated with the wall surface of the ridge and the above-mentioned high portion of the groove wall surface of the breaker groove.

  In addition, when forming a ridge part in the groove | channel wall surface of a breaker groove | channel like these, it is the said groove | channel in order toward the direction where the said other edge part extends from a corner part. It is desirable that the height with respect to the bottom surface is increased and the length along the direction in which the cutting edge extends is increased. As a result, it is possible to obtain optimum chip disposability for the width of the generated chips in a wide cutting area from intermediate finishing to rough cutting.

  Contrary to the above, when the cutting insert is exclusively used for finish cutting, the groove wall surface of the breaker groove is not provided with a protrusion, and the groove wall surface is used as a continuous surface. On the groove bottom surface of the groove, only the concave portion that is recessed with respect to the groove bottom surface is formed on the corner portion side, and the inner wall surface facing the cutting edge side of the concave portion and the groove wall surface of the breaker groove are used as the plurality of stepped wall portions. Also good. Even in such a case, chips generated on the corner side of the cutting edge during finish cutting are caused by the wall surface of the recess and the breaker groove wall surface disposed higher than the groove bottom surface. On the other hand, even if it is used for rough cutting or the like, it is possible to treat wide chips without increasing resistance or clogging by the groove wall surface of the breaker groove.

  As described above, according to the present invention, in a cutting insert having a cutting edge formed on one of a pair of side ridges intersecting the corner portion of the rake face, the width on the corner portion side of the cutting edge is reduced. In finish cutting where small chips are generated, the chips can be reliably processed by colliding with multiple steps of the wall, while in rough cutting where almost the entire length of the cutting blade is used to generate wide chips. General purpose capable of reducing cutting resistance and preventing clogging of chips without unnecessarily imparting excessive resistance to chips, and enabling smooth and stable chip disposal from finish cutting to rough cutting It is possible to provide a cutting insert with high performance.

  1 to 6 show a first embodiment of the present invention. In the cutting insert of the present embodiment, the insert body 1 is formed of a hard material such as cemented carbide to form an equilateral triangular flat plate shape, and the front and back surfaces forming the equilateral triangle are the rake face 2. Three side surfaces arranged around the rake face 2 are defined as flank faces 3, and the rake face 2 is formed at a side ridge portion of the rake face 2 which is an intersection ridge line portion between the rake face 2 and the flank face 3. Only one of the pair of side ridges intersecting each corner portion 4 of the equilateral triangle (a side ridge portion extending in a clockwise direction from each corner portion 4 in FIG. 2) extends from the corner portion 4. Each of the blades 5 is formed, and the rake face 2 is a free insert having a breaker groove 6 formed so as to extend from the corner portion 4 along the cutting blade 5.

  Here, the insert body 1 has a mounting hole 7 that passes through the insert body 1 in the thickness direction (vertical direction in FIGS. 3 to 6) so as to open in the center of the equilateral triangle formed by the rake face 2. The insert body 1 is formed in a rotational symmetry of 120 ° around the center line of the mounting hole 7 and is also formed in a reverse-inversion symmetry. Further, the rake surfaces 2 on the front and back sides are formed in a planar shape perpendicular to the thickness direction except for the opening portion of the mounting hole 7 and the breaker groove 6, and the flank 3 extends along the thickness direction. Therefore, the cutting insert of this embodiment is a negative type insert in which the flank 3 and the rake face 2 are orthogonal to each other. In addition, each corner part 4 is made into the 1/3 convex circular arc shape which touches the said pair of side ridge part smoothly in planar view along this thickness direction.

  The breaker groove 6 includes a groove bottom surface 6a that is continuous with the cutting edge 5 and a groove wall surface 6b that is continuous with the groove bottom surface 6a and rises toward the cutting edge 5 and is orthogonal to the cutting edge 5. In the cross section, the groove bottom surface 6a is a flat surface inclined so as to gradually recede at a constant angle toward the inside of the rake face 2, and the groove wall surface 6b smoothly contacts the groove bottom face 6a in the same section. It is a concave arcuate curved surface that cuts to the side. Therefore, strictly speaking, the cutting edge 5 is formed at the intersecting ridge line portion between the groove bottom surface 6a of the breaker groove 6 and the flank surface 3, and the position in the thickness direction is in the thickness direction. The rake face 2 is set at a low position slightly lower than the planar portion of the rake face 2 and is formed so as to extend perpendicularly to the thickness direction.

  Such a breaker groove 6 is a portion on the corner portion 4 side of the other side ridge portion of the pair of side ridge portions intersecting the corner portion 4 from the corner portion 4 on the corner portion 4 side where the cutting edge 5 is continuous. Therefore, the cutting edge 5 in the corner portion 4 has the thickness as it goes from the one side ridge portion side to the other side ridge portion side as shown in FIG. It is inclined so as to gradually recede in the direction. Further, the breaker groove 6 extends from the corner portion 4 side in a direction in which the cutting edge 5 extends so that the groove width is constant, and on the opposite side to the corner portion 4 is a regular triangle formed by the rake face 2. A concave curved surface is formed around the midpoint of one side, and the groove is cut to the rake face 2 side so that the groove width is reduced. Accordingly, the breaker grooves 6 formed on one rake face 2 do not intersect with each other in the present embodiment and also do not intersect with the mounting hole 7, and the rake face 2 has a planar shape therebetween. The left part is left.

  And in such a breaker groove | channel 6, the multi-step wall part extended toward the direction where this cutting blade 5 extends from the corner part 4 side toward the cutting blade 5 side is further formed, The plurality of stepped wall portions extend in order from the corner portion 4 in the direction in which the other side ridge portion extends, so that the height of the breaker groove 6 with respect to the groove bottom surface 6a increases. The length along the direction is long. Note that the height of the wall portion with respect to the groove bottom surface 6a is, for example, a rake face in a direction perpendicular to the flat surface when the groove bottom surface 6a is inclined as described above as in the present embodiment. However, the height may be simply the height in the thickness direction from the tangent L portion between the groove bottom surface 6a and the groove wall surface 6b, which is the deepest portion of the breaker groove 6.

  In forming such a multi-stage wall portion, in the present embodiment, firstly, a recess 8 that is recessed with respect to the groove bottom surface 6a is formed on the corner portion 4 side on the groove bottom surface 6a. The inner wall surface 8a of the recess 8 facing the cutting blade 5 is the first wall on the cutting blade 5 side among the plurality of wall portions. Here, the concave portion 8 includes a bottom surface 8b that is recessed by one step parallel to the groove bottom surface 6a, and the inner wall surface that is inclined so as to gradually recede from the bottom surface 8b toward the groove bottom surface 6a. 8a including four inner wall surfaces, and from the corner portion 4 to a slight portion of the cutting edge 5 on the corner portion 4 side, between the corner portion 4 and the cutting edge 5 and the tangent line L, respectively. It is recessed so as to have a very small fixed interval.

  Therefore, the groove bottom surface 6a is left between the concave portion 8 and the corner portion 4, the cutting edge 5, and the tangent L. Also, as shown in FIG. The inner wall surface on the corner portion 4 side is formed to be curved along the corner portion 4, and the inner wall surface on the cutting blade 5 side and the tangent L side facing the inner wall surface and facing the cutting blade 5 side are formed. The inner wall surface 8a is formed so as to extend in parallel with the cutting edge 5, while the inner wall surface facing the corner portion 4 is formed so as to extend in a direction perpendicular to the cutting edge 5 in this embodiment. The depth of the recess 8 from the groove bottom surface 6a is, for example, sufficiently smaller than the depth of the breaker groove 6 from the rake face 2, and the inner wall surface 8a has a wall with respect to the groove bottom surface 6a of the breaker groove 6. The height of the part is a negative height.

  On the other hand, in the present embodiment, when forming the plurality of stepped wall portions, secondly, the protruding portion 9 extending from the corner portion 4 side toward the extending direction of the cutting edge 5 is formed on the groove wall surface 6b of the breaker groove 6. The protruding portion 9 is formed so as to protrude from the groove wall surface 6b, and the length of the protruding portion 9 in the direction in which the cutting edge 5 extends is longer than that of the recessed portion 8, and the length of the groove wall surface 6b of the breaker groove 6 is long. It is shorter than that. In addition, in the present embodiment, a plurality of such protrusions 9 are formed on the groove wall surface 6b (two in this embodiment), and the other side ridge is aligned in the extending direction. The second protrusion 9B opposite to the cutting edge 5 is longer than the first protrusion 9A on the cutting edge 5 side in the direction in which the cutting edge 5 extends, and the breaker groove 6 The height with respect to the groove bottom surface 6a is increased, and the wall surface 9a facing the cutting edge 5 side of the protrusions 9A and 9B is the second and third wall portions, respectively.

  Here, both of the first and second protrusions 9A and 9B are formed in the thickness direction from the planar protrusion top surface 9b perpendicular to the thickness direction and the groove bottom surface 6a side of the breaker groove 6. The wall surface 9a is inclined so as to gradually recede toward the top surface 9b, and the cross-ridge line portion between the wall surface 9a and the top surface 9b has a cross section as shown in FIG. Convex curve chamfering is applied. The height of the wall surface 9a up to the top surface 9b with respect to the groove bottom surface 6a is higher in the second protrusion 9B than in the first protrusion 9A, and the height with respect to the groove bottom 6a. The height of the wall surface 9a of the first protrusion 9A is higher than that of the inner wall surface 8a of the negative recess 8.

  In addition, the inclination angle of the wall surface 9a that is inclined backward in this way with respect to the thickness direction is such that the inclination angle of the first protrusion 9A on the cutting blade 5 side is larger than the inclination angle of the second protrusion 9B. And, it is set to be smaller than the inclination angle of the inner wall surface 8a of the concave portion 8, that is, the first wall portion from the inner wall surface 8a which is the first step wall portion to the second step and third step wall portions. The slopes are steep in order toward the wall surface 9a of the second protrusions 9A and 9B. Further, the first and second protrusions 9A and 9B extend to the other side ridge portion side of the corner portion 4 while maintaining the cross-sectional shape shown in FIG. 5, and as shown in FIG. It is made to cross | intersect the flank 3 which continues to the edge part.

  Further, the first protrusion 9A protrudes from the wall surface 9a of the second protrusion 9B slightly beyond the tangent line L to the cutting edge 5 side on the cutting edge 5 side of the groove wall surface 6b of the breaker groove 6. However, it is formed so as not to overlap the concave portion 8 of the groove bottom surface 6a, and the wall surface 9a of the first protrusion 9A is directed in the direction in which the cutting edge 5 extends from the corner portion 4. After extending in parallel with the cutting edge 5, the convex part is drawn from the vicinity of the recess 8 and is retracted with respect to the cutting edge 5 to intersect the wall surface 9a of the second protrusion 9B. Further, the wall surface 9a of the second protrusion 9B extends in parallel with the cutting blade 5 in the direction in which the cutting blade 5 extends from the corner portion 4 and is about ½ of the length of the breaker groove 6. It is formed so as to recede with respect to the cutting edge 5 while drawing a convex curved surface from the position and intersect the groove wall surface 6 b of the breaker groove 6.

  Furthermore, in the present embodiment, as the third of the plurality of wall portions, a second protrusion having a high height from the groove bottom surface 6a of the breaker groove 6 among the first and second protrusions 9A and 9B. Also in the strip portion 9B, the height of the protruding top surface 9b is made smaller than the height of the groove wall surface 6b from the groove bottom surface 6a to the flat rake face 2, that is, the groove depth of the breaker groove 6. Thus, a groove wall surface 6b of the breaker groove 6 is left between the top surface 9b of the second protrusion 9B and the rake face 2, and the groove wall surface 6b is grooved more than the protrusion 9. The height of the bottom surface 6a is high, and the length along the direction in which the cutting blade 5 extends is a fourth-stage wall portion. Here, the portion on the rake face 2 side of the groove wall surface 6b, which is the fourth step wall portion, has a second ridge portion whose inclination angle with respect to the thickness direction is the third step wall portion. The slope angle of the wall surface 9a of 9B is smaller than the inclination angle, that is, the rake face 2 perpendicular to the thickness direction has a steep slope in the order of the first to fourth wall portions from the cutting edge 5 side. .

  When the cutting insert configured as described above is used to perform finish cutting of a workpiece using a portion from the corner portion 4 of the cutting edge 5 to the concave portion 8 on the corner portion 4 side, the cutting insert is arbitrarily used. In other words, the cutting edge 5 and the breaker groove 6 are formed so as to extend along only one side ridge portion of the pair of side ridge portions intersecting the corner portion 4. Since the opening of the breaker groove 6 is cut off along the side ridge and is connected to the rake face 2, the small chip generated on the corner 4 side of the cutting blade 5 is the other side ridge. It flows out in the direction in which the portion extends, and is reliably guided from the groove bottom surface 6a of the breaker groove 6 to the groove wall surface 6b.

  The breaker groove 6 has a plurality of steps (four steps in the present embodiment) extending from the corner portion 4 toward the cutting blade 5 side and extending in the direction in which the cutting blade 5 extends from the corner portion 4 side. The cutting edge is formed so that the height with respect to the groove bottom surface 6a is increased in order toward the direction in which the other side ridge extends, and the length along the direction in which the cutting edge 5 extends is increased. 5 corners 4 are erected in such a way that these four-step wall portions become higher in order toward the outflow direction of the chips, so that the chips guided by the breaker grooves 6 as described above are put on these wall portions. By sequentially impinging and applying resistance, it is possible to reliably curl and process.

  That is, according to the cutting insert of the first embodiment, the chips generated on the corner portion 4 side of the cutting edge 5 at the time of finish cutting first fall into the recess 8 from the groove bottom surface 6a of the breaker groove 6. Then, it collides with the inner wall surface 8a facing the cutting edge 5 which is the first-stage wall portion, and then flows out from the concave portion 8 to the groove wall surface 6b side of the breaker groove 6 and is formed on the groove wall surface 6b. In the part 9, it collides with each wall surface 9a of the 1st, 2nd protrusion part 9A, 9B made into the wall part of the 2nd step and the 3rd step. Further, the chips colliding with the wall surface 9a of the second protrusion 9B in this way are left on the groove wall surface 6b of the breaker groove 6 as the fourth wall portion left between the top surface 9b and the rake face 2. In this way, resistance is given one after another by sequentially colliding with the wall portions of the plurality of stages in this way, so that the chips are curled and divided and processed.

  In addition, for such finish cutting, it is generated in the case of rough cutting that uses the substantially entire length of the cutting edge 5 formed at the intersecting ridge line portion of the groove bottom surface 6a of the breaker groove 6 and the flank 3. The wide chips flow out from the cutting edge 5 to the groove bottom surface 6a in the same manner as in the finish cutting. However, since they are wide, they fall into the recesses 8 and receive resistance by the inner wall surface 8a which is the first-stage wall portion. There are few, it flows out to the groove wall surface 6b side of the breaker groove | channel 6 as it is, it collides with the wall surface 9a of the 1st, 2nd protrusion part 9B in the said protrusion part 9, and also this 2nd protrusion part 9B and rake face 2 It is made to curl by colliding with the groove wall surface 6b between them and receiving resistance.

  However, the wall surface 9a of the second ridge portion 9B, which is the third-stage wall portion, has a length in the direction in which the cutting blade 5 extends from the corner portion 4 with respect to the groove wall surface 6b that is the fourth-stage wall portion. The wall surface of the first protrusion 9A, which is short and further the second stage wall, is shorter than the wall surface 9a of the second protrusion 9B. The applied resistance decreases sequentially. Therefore, in the above-described rough cutting from the semi-finished cutting in which the width of the chip exceeds the length of the concave portion 8, resistance is received by the inner wall surface 8a of the concave portion 8 which is the first-stage wall portion as described above. Combined with the small amount, the resistance more than necessary does not act on the chips, so that it is possible to suppress an increase in the cutting resistance generated in the cutting insert, and wide chips are clogged in the breaker groove 6. Can also be prevented.

  Thus, according to the cutting insert having the above-described configuration, in the finish cutting, chips generated on the corner portion 4 side of the cutting edge 5 can be reliably guided to the breaker groove 6. It can be curled and processed by giving sufficient resistance by colliding with a plurality of fourth-stage walls. On the other hand, it is possible to avoid excessive resistance from acting on wide chips generated in the incision region from intermediate finish cutting to rough cutting, resulting in increased cutting resistance and chip clogging. Therefore, it is possible to treat the chips with the above-mentioned plurality of wall portions, and therefore, it is possible to treat the chips smoothly and stably in all areas from finish cutting to rough cutting.

  Moreover, in the cutting insert of the present embodiment, a plurality of ridges 9 (first and second ridges 9A, 9B) are formed on the groove wall surface 6b of the breaker groove 6, and the cutting blade As the distance from the side 5 increases, the height of the groove bottom surface 6a increases in order, and the length in the direction in which the cutting blade 5 extends increases in order. Among the cut areas, it is possible to obtain processing performance suitable for the width of chips generated for each fine cut area.

  That is, in the semi-finished cutting in which chips having a width similar to the length of the first protrusion 9A are generated, the wall surface 9a of the first protrusion 9A and the wall surface of the second protrusion 9B In the rough cutting in which chips having a width similar to the length of the second protrusion 9B are generated, while the necessary and sufficient resistance can be imparted to the chips by 9a and the groove wall surface 6b, the chips can be curled. Similarly, although resistance is provided by the wall surface 9a and the groove wall surface 6b of the first and second protrusions 9A and 9B, the resistance that acts on the unit width of the chip by the short amount of the first protrusion 9A. Therefore, it is possible to more reliably prevent an increase in cutting resistance and clogging of chips. However, in this embodiment, the first and second two ridges 9A and 9B are formed in this way, but depending on the cutting conditions, the size of the insert body 1, etc., the one ridge 9 is formed. Only three protrusions 9 or more may be formed.

  Further, particularly in the present embodiment, the plurality of steps of the wall portions are arranged in order from the cutting blade 5 side, that is, from the inner wall surface 8a of the first step recess 8 to the wall surfaces 9a of the first and second protrusions 9A and 9B. , And in order of the groove wall surface 6b of the breaker groove 6 between the second protrusion 9B and the rake face 2, the gradient is formed so that the chips are separated from the cutting blade 5. The greater the wall, the greater the resistance. For this reason, even if the chips are not sufficiently curled only by the front wall portion on the cutting blade 5 side, a large resistance is gradually given to the chips as it collides with the rear wall portion. According to this, it becomes possible to achieve more reliable chip disposal.

  On the other hand, in the present embodiment, the wall surface 9a of the first and second ridges 9A and 9B in the second and third steps out of the plurality of steps is convex at the end opposite to the corner 4. It is formed so as to recede with respect to the cutting edge 5 while drawing a curved surface and to be immersed so as to intersect with the wall surface 9a of the second protrusion 9B and the groove wall surface 6b of the breaker groove 6. When the chips are generated with a width larger than the length of the protruding portion 9A, or when the chips are generated with a width larger than the length of the second protruding portion 9B by rough cutting, the cutting blade 5 extends. It is also possible to avoid a large resistance acting on the chips at the step between the first and second protrusions 9A and 9B in the direction and at the difference between the second protrusion 9B and the groove wall surface 6b.

  In addition, the cutting surface 5 of the present embodiment in which the rake surfaces 2 on the front and back sides of the insert body 1 are symmetrically reversed and the cutting edge 5 and the breaker groove 6 are formed only from the corner portion 4 to one side ridge portion side. In the insert, as shown in FIGS. 1, 3, and 4, with respect to the cutting edge 5 and the breaker groove 6 excluding the corner portion 4 of one rake face 2, the other rake face is opposite to the front and back sides. The part made into the flat surface perpendicular | vertical to the thickness direction of 2 insert main bodies 1 is left. For this reason, the cutting force acting on the cutting edge 5 and the breaker groove 6 used in intermediate finish cutting and rough cutting is reliably secured by the insert mounting seat of the cutting tool through the flat rake face 2 on the opposite side. Therefore, it is possible to prevent a situation in which the mounting stability of the insert is impaired during the cutting and the cutting accuracy is deteriorated by such cutting resistance.

  By the way, in the said 1st Embodiment, while the recessed part 8 which defines the inner wall face 8a used as the 1st step wall part is formed in the groove bottom face 6a of the breaker groove | channel 6, the groove wall face 6b has 2 or 3 steps | paragraphs. First and second protrusions 9A and 9B that define a wall surface 9a to be the eye wall are formed, and the groove wall surface of the breaker groove 6 between the second protrusion 9B and the rake face 2 6b constitutes the fourth-stage wall portion. For example, in the case where the cutting insert is exclusively used for intermediate finishing to rough cutting, the second embodiment of the present invention shown in FIGS. As in the cutting insert of the embodiment, the recess 8 is not formed on the groove bottom surface 6a of the breaker groove 6, but the first and second protrusions 9A and 9B having the wall surface 9a only on the groove wall surface 6b are formed. May be.

  Therefore, in the second embodiment, the groove bottom surface 6a of the breaker groove 6 is a flat surface that is inclined so as to gradually recede from the cutting edge 5 toward the inside of the rake face 2 at a constant angle. The wall surface 9a of the first protrusion 9A is the first wall, the wall 9a of the second protrusion 9 is the second wall, the second protrusion 9B and the rake face 2. The groove wall surface 6b of the breaker groove 6 in between constitutes the third-stage wall portion. In the second embodiment and the third embodiment shown in FIGS. 13 to 18 to be described later, the same reference numerals are given to the same components as those in the first embodiment shown in FIGS. The explanation is omitted.

  When such a cutting insert of the second embodiment is used for rough cutting from the above-described intermediate finish cutting, in the same manner as the chips flow out over the recess 8 in the first embodiment, It is possible to achieve a smooth and efficient chip treatment without increasing the cutting resistance and without causing clogging of chips. On the other hand, even if it is used for finish cutting in which chips are generated only at the corner 4 side of the cutting edge 5, the first and second protrusions 9A and 9B are formed in the breaker groove 6 on the corner 4 side. Since the three-stage wall portions of each wall surface 9a and groove wall surface 9b are formed so as to increase the height from the groove bottom surface 6a in order, chips are collided with these wall portions in order to make resistance. Can be processed.

  On the other hand, when the cutting insert is exclusively used for finish cutting, a breaker groove is formed as in the cutting insert according to the third embodiment of the present invention shown in FIGS. The groove bottom surface 6a is merely formed with the concave portion 8 that defines the inner wall surface 8a serving as the first-stage wall portion, and the groove wall surface 6b may not have the protrusion 9 formed thereon. That is, in the third embodiment, the entire groove wall surface 6b of the breaker groove 6 is smoothly in contact with the groove bottom surface 6a on the rake face 2 side as shown in FIGS. The inner wall surface 8a facing the cutting edge 5 side of the concave portion 8 constitutes the first-stage wall portion, and the groove wall surface 6b itself of the breaker groove 6 constitutes the second-stage wall portion. It will be.

  In such a cutting insert of the third embodiment, in finishing cutting in which only the corner portion 4 side of the cutting blade 5 is used to generate a chip having a small width, the chip is firstly the same as in the first embodiment. Resistance is obtained by falling into the recess 8 and colliding with the inner wall surface 8a, and then flowing out while sliding in contact with the groove wall surface 6b of the breaker groove 6 so that the resistance is further curled and processed. On the other hand, in the case of intermediate finish cutting or rough cutting, the chips get over the recesses 8, so the cutting resistance is less likely to increase unnecessarily, and it is possible to more reliably prevent the chips from becoming clogged. .

  Next, FIGS. 19 to 24 show modifications of the first embodiment, FIGS. 25 to 30 show modifications of the second embodiment, and FIGS. 31 to 36 show modifications of the third embodiment. Each component is shown, and the same reference numerals are assigned to components common to the corresponding embodiments to simplify the description. Here, in the first to third embodiments, the insert main body 1 has a regular triangular flat plate shape, and the front and back regular triangular surfaces are the rake face 2, whereas in these modifications, the insert main body 1 is the insert main body. 1 is a square flat plate shape, and among the four rectangular surfaces arranged around the pair of square surfaces, a pair of rectangular surfaces located on opposite sides is a rake face 2, and the pair of square surfaces Is the flank 3

  Then, from the pair of corner portions 4 that are diagonally positioned among the four corner portions of the rake face 2, one long side ridge of the pair of side ridge portions of the rake face 2 that intersects the corner portion 4 respectively. The cutting edge 5 is formed so as to extend to the intersection, that is, the intersecting ridge line part of the rake face 2 and the flank face 3, and the breaker groove 6 is formed from the corner part 4 along the cutting edge 5 on the rake face 2. Has been. Therefore, the cutting inserts of these modified examples are also of a negative type with a selfishness, and are so-called vertical blade cutting inserts.

  In these modified examples, the insert body 1 is opened in the thickness direction (FIGS. 20, 22, 26, 26) so that the insert body 1 opens in the center of the square surface as the flank 3. A mounting hole 7 penetrating in the vertical direction in FIGS. 28, 32, and 34 is formed, and the insert body 1 is formed in a rotational symmetry of 180 ° around the center line of the mounting hole 7, that is, The pair of rake surfaces 2 are formed to be reversely symmetric with respect to each other, and each rake surface 2 is also 180 ° rotationally symmetric around the center line of the rectangular surface perpendicular to the center line of the mounting hole 7. In addition, each of the four corner portions of the rake face 2 includes a pair of corner portions 4 from which the cutting edge 5 extends, and has a ¼ convex arc shape in plan view along the center line.

  Here, the said breaker groove | channel 6 is opened by the said corner part 4 side in a pair of other rectangular surfaces other than the rectangular surface used as the scoop surface 2 among the said four rectangular surfaces of the insert main body 1, In the modification, the width of the groove bottom surface 6a, which is an inclined plane that gradually recedes at a constant angle toward the inside of the rake face 2, has a corner as shown in FIG. 20, FIG. 26, and FIG. It is formed so as to gradually increase in the direction in which the cutting blade 5 extends from the portion 4. On the other hand, the groove wall surface 6b having a concave arcuate curved surface that cuts smoothly in contact with the groove bottom surface 6a is formed such that the width in the plan view is gradually reduced in the direction in which the cutting blade 5 extends. ing.

  Therefore, the tangent L between the groove bottom surface 6a and the groove wall surface 6b, which is the groove bottom of the breaker groove 6, is the other side ridge portion of the rake surface 2 that intersects the corner portion 4, that is, the rake surface. 2 extends obliquely from the corner portion 4 side of the short side ridge portion of the rectangular surface toward the center of the rectangular surface, and its depth gradually increases. Further, the breaker groove 6 is cut off from about 1/2 of the length of the long side ridge in the extending direction of the cutting edge 5, and exceeds the half of the length and is opposite to the same rake face 2 The breaker grooves 6 are crossed with the groove wall surface 6b of the breaker groove 6, and the breaker grooves 6 formed on one rake face 2 communicate with each other at the central portion of the rectangular surface.

  In these modified examples, the long side ridge is formed from a portion of the rake face 2 other than the portion where the breaker grooves 6 are formed, that is, from a pair of corner portions other than the pair of corner portions 4 from which the cutting blade 5 extends. Convex portions 2A projecting one step from the rake face 2 are formed at portions extending along the portion. The projecting top surfaces of these convex portions 2A are located on one plane perpendicular to the center line of the rectangular surface formed by the rake face 2 and protrude most on the rake face 2 in the direction of the center line. The cutting edge 5 is formed so as to extend parallel to the plane at a position retreated from the one plane in the direction of the center line.

  Of these, in the modifications of the first and third embodiments, the recess 8 is formed on the corner portion 4 side of the groove bottom surface 6a, and the inner wall surface 8a facing the cutting blade 5 side is the first step. It is a wall. Here, in the concave portion 8 in these modified examples, as the tangent line L extends obliquely as described above, the inner wall surface 8a along the tangent line L also extends from the corner portion 4 side. The inner wall surface of the portion along the corner portion 4 is formed in a trapezoidal shape in the plan view, which is inclined so as to be separated from the cutting blade 5 in the direction. Similarly to the third embodiment, a quarter arc shape along the corner portion 4 is formed.

  In the modification of the first and second embodiments, the groove wall surface 6b has a plurality of protrusions 9 extending in the direction in which the cutting edge 5 extends from the corner part 4 side (in these modifications, two lines are also provided). ) Is formed. These ridges 9 are, in order from the corner 4 toward the direction in which the other side ridge extends, a second ridge opposite to the first ridge 9A on the cutting blade 5 side. The strips 9B are formed so that the height with respect to the groove bottom surface 6a is higher and the length along the direction in which the cutting blade 5 extends is longer, and faces the respective cutting blades 5 side. In the modification of the first embodiment, the wall surface 9a is the second and third walls, and in the modification of the second embodiment, the wall 9a is the first and second walls.

  In addition, in the modified example, these ridges 9 are also directed toward the center of the rectangular surface inside the rake face 2 in the direction in which the cutting edge 5 extends from the corner part 4 side. Similarly, in the plan view, as shown in FIG. 20 and FIG. 26, it is inclined toward the inside of the rake face 2 so as to be separated from the cutting edge 5. Moreover, in the modification of these 1st, 2nd embodiment, the protrusion part 9 is formed so that it may protrude over the said groove | channel bottom face 6a straddling the said tangent L, Among these, 9A of 1st protrusion parts Is formed so as to be immersed in the wall surface 9a of the second protruding portion 9B in the direction in which the cutting edge 5 extends, beyond the recess 8 and exceeding ½ of the length of the cutting edge 5. The protrusion 9B is formed so as to extend to the vicinity of the center of the rectangular surface over substantially the entire length of the groove wall surface 6b.

  Moreover, in the modification of these 1st, 2nd embodiment, it is on the opposite side to the cutting blade 5 of the 2nd protrusion part 9B among these, rather than the protrusion top surface 9b of this 2nd protrusion part 9B. Furthermore, the groove wall surface 6b portion of the breaker groove 6 extending to a higher position with respect to the groove bottom surface 6a is left, and the groove wall surface 6b of this portion is the fourth-stage wall portion in the modification of the first embodiment, In the modification of the second embodiment, the third-stage wall portion is used. On the other hand, in the modified example of the third embodiment, these protrusions 9 are not formed, and the groove wall surface 6b extends toward the center while having a concave arc shape in cross section, and the next 2 of the inner wall surface 8a. It is the wall of the step.

  The cutting inserts of the modifications of the first to third embodiments configured as described above are, for example, the above-described rake face 2 opposite to the rake face 2 on which the cutting edge 5 used for the cutting is formed. The protruding top surface of the convex portion 2A, the flank 3 opposite to the flank 3 of the cutting edge 5, and the corner opposite to the corner 4 where the cutting edge 5 is connected to the flank 3 on the opposite side. The four rectangular side surfaces of the insert main body 1 that intersect at the portion 4 are brought into contact with three wall surfaces that are orthogonal to each other and formed on the insert mounting seat of the cutting tool, so that the mounting is performed. It is detachably fixed by a clamping means such as a clamping screw, a clamping pin or a clamping piece inserted into the hole 7.

  Also in these modified examples, the breaker groove 6 formed along the cutting edge 5 used for the cutting is directed toward the cutting edge 5 in the direction in which the cutting edge 5 extends from the corner portion 4 side. A plurality of wall portions extending toward the groove bottom surface 6a in order from the corner portion 4 toward the direction in which the other side ridge portion of the pair of side ridge portions of the rake face 2 intersecting the corner portion 4 extends. Since the length along the direction in which the cutting blade 5 extends is increased, the chips are surely guided to the breaker groove 6 at the time of finish cutting. While it can be processed by giving resistance to the wall portion, the number of steps of the wall portion where the chips collide on the side away from the corner portion 4 of the cutting edge 5 is reduced in the intermediate finish cutting and rough cutting. It is possible to prevent an increase in the size and clogging of chips.

  In these modified examples, the width of the groove bottom surface 6a of the breaker groove 6 gradually increases in the direction in which the cutting edge 5 extends from the corner portion 4 side. Since a large capacity of the breaker groove 6 can be secured, clogging of chips at the time of intermediate finishing cutting, particularly rough cutting can be more reliably eliminated. In addition, since the breaker grooves 6 formed on one rake face 2 communicate with each other at the central portion of the rectangular surface of the insert body 1 that is the rake face 2, the opposite sides are communicated with each other. It is also possible to discharge chips to the breaker groove 6 and smoothly discharge the chips generated during intermediate finish cutting and particularly rough cutting without causing clogging.

1 is a perspective view showing a first embodiment of the present invention. FIG. 2 is a plan view of the first embodiment shown in FIG. 1 as viewed from the direction facing the rake face 2 along the center line of the mounting hole 7. It is the side view which looked at 1st Embodiment shown in FIG. 1 from the direction which opposes one flank 3 perpendicularly | vertically. FIG. 2 is a side view of the first embodiment shown in FIG. 1 viewed from a direction parallel to one flank 3. It is AA sectional drawing in FIG. It is BB sectional drawing in FIG. It is a perspective view which shows the 2nd Embodiment of this invention. It is the top view which looked at 2nd Embodiment shown in FIG. 7 from the direction which opposes the rake face 2 along the centerline of the attachment hole 7. FIG. It is the side view which looked at 2nd Embodiment shown in FIG. 7 from the direction which opposes one flank 3 perpendicularly | vertically. It is the side view which looked at 2nd Embodiment shown in FIG. 7 from the direction parallel to one flank 3. It is AA sectional drawing in FIG. It is BB sectional drawing in FIG. It is a perspective view which shows the 3rd Embodiment of this invention. It is the top view which looked at 3rd Embodiment shown in FIG. 13 from the direction which opposes the rake face 2 along the centerline of the attachment hole 7. FIG. It is the side view which looked at 3rd Embodiment shown in FIG. 13 from the direction which opposes one flank 3 perpendicularly | vertically. It is the side view which looked at 3rd Embodiment shown in FIG. 13 from the direction parallel to one flank 3. It is AA sectional drawing in FIG. It is BB sectional drawing in FIG. It is a perspective view which shows the modification of the 1st Embodiment of this invention. FIG. 20 is a plan view of a modification of the first embodiment shown in FIG. 19 as viewed from the direction facing the rake face 2 along the center line of the rake face 2. FIG. 20 is a side view of a modification of the first embodiment shown in FIG. 19 as viewed from the direction facing the flank 3 along the center line of the mounting hole 7. It is the side view seen from the direction parallel to the rake face 2 and the flank 4 in the modification of 1st Embodiment shown in FIG. It is AA sectional drawing in FIG. It is BB sectional drawing in FIG. It is a perspective view which shows the modification of the 2nd Embodiment of this invention. FIG. 26 is a plan view of a modification of the second embodiment shown in FIG. 25 as viewed from the direction facing the rake face 2 along the center line of the rake face 2. FIG. 26 is a side view of a modification of the second embodiment shown in FIG. 25 as viewed from the direction facing the flank 3 along the center line of the mounting hole 7. It is the side view seen from the direction parallel to the rake face 2 and the flank face 4 in the modification of 2nd Embodiment shown in FIG. It is AA sectional drawing in FIG. It is BB sectional drawing in FIG. It is a perspective view which shows the modification of the 3rd Embodiment of this invention. FIG. 32 is a plan view of a modification of the third embodiment shown in FIG. 31 as viewed from the direction facing the rake face 2 along the center line of the rake face 2. FIG. 32 is a side view of a modification of the third embodiment shown in FIG. 31 as viewed from the direction facing the flank 3 along the center line of the mounting hole 7. FIG. 32 is a side view of the modified example of the first embodiment shown in FIG. 31 as viewed from a direction parallel to the rake face 2 and the flank face 4. It is AA sectional drawing in FIG. It is BB sectional drawing in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Insert body 2 Rake face 3 Flank face 4 Corner part 5 Cutting edge 6 Breaker groove 6a Groove bottom face of breaker groove 6 6b Groove wall surface (wall part) of breaker groove 6
8 Concave portion 8a Inner wall surface (wall portion) facing the cutting blade 5 side of the concave portion 8
8b Bottom surface of recess 8 9, 9A, 9B Projection portion 9a Wall surface (wall portion) of projection portion 9
9b Top surface of the ridge 9

Claims (5)

  A cutting blade extending from the corner portion is formed on one side ridge portion of the pair of side ridge portions intersecting the corner portion of the rake face, and a groove bottom surface connected to the cutting edge and the groove bottom surface are formed on the rake face. A breaker groove having a groove wall surface rising from the corner toward the cutting edge is formed so as to extend along the cutting edge from the corner, and the breaker groove faces the cutting edge and is A plurality of stepped wall portions extending from the corner portion toward the extending direction of the cutting edge are sequentially directed to the groove bottom surface from the corner portion toward the extending direction of the other side ridge portion of the pair of side ridge portions. A cutting insert characterized by being formed so as to have a high height and a length along a direction in which the cutting blade extends.   A recess that is recessed with respect to the groove bottom surface is formed on the corner portion side of the groove bottom surface of the breaker groove, and the cutting blade extends toward the direction in which the cutting blade extends from the corner portion side on the groove wall surface of the breaker groove. And the inner wall surface facing the cutting edge side of the recess and the wall surface facing the cutting edge side of the protrusion are the plurality of wall portions. The cutting insert according to claim 1, wherein:   On the groove wall surface of the breaker groove, a protrusion that extends shorter than the groove wall surface in the direction in which the cutting blade extends from the corner side is formed at a position lower than the groove wall surface with respect to the groove bottom surface. The wall surface of the ridge portion facing the cutting edge and the portion of the groove wall surface that is higher than the ridge portion with respect to the groove bottom surface are the multi-stage wall portions. The cutting insert according to claim 1, wherein:   In the groove wall surface of the breaker groove, a plurality of the protrusions are sequentially increased in the height from the groove bottom in the direction in which the other side ridge extends from the corner part, and The cutting insert according to claim 2 or 3, wherein the cutting insert is formed so that a length along a direction in which the cutting blade extends is long.   On the groove bottom surface of the breaker groove, a recess recessed with respect to the groove bottom surface is formed on the corner portion side, an inner wall surface facing the cutting edge side of the recess, and a groove wall surface of the breaker groove, The cutting insert according to claim 1, wherein the plurality of stepped wall portions are used.

Images