JP5071048B2 - Insert detachable cutting tool head member and insert detachable cutting tool - Google Patents

Description

  The present invention provides a head member of an insert detachable cutting tool that forms an insert detachable cutting tool by forming an insert mounting seat to which a cutting insert having a cutting blade is detachably attached and being attached to the tip of a holder, In addition, the present invention relates to an insert detachable cutting tool which is mounted on the tip of a holder and used, for example, for grooving or parting off a work material.

As an insert detachable cutting tool used for such grooving and parting-off, one of the jaws formed at the tip of the holder is provided with a pressing surface, and the other jaw is a pedestal. An insert mounting seat is formed by arranging the pressing surface and the pedestal surface so as to face each other, and a slit extends from the rear end of the insert mounting seat toward the rear end side. The one jaw is elastically deformed by screwing a clamp screw engaged with one jaw, and a cutting insert having a cutting blade is clamped and attached between the pressing surface and the pedestal surface. Is known. Patent Document 1 proposes an insert detachable cutting tool in which this insert mounting seat is formed on a head member that is detachably attached to the tip of a holder by a fixing screw.
Japanese Patent Laid-Open No. 05-192802

  In such an insert detachable cutting tool, the one jaw portion includes a rear wall surface facing the front end side of the rear end of the slit, a holder positioned on the slit extending direction side with respect to the rear wall surface, and the head member. The pair of jaw portions between the rear end surfaces is elastically deformed toward the other jaw portion with the connecting portion as a fulcrum. Therefore, if the connecting portion serving as the fulcrum is close to the insert mounting seat, when the one jaw portion is elastically deformed, the inclination of the pressing surface changes greatly even if the pressing surface approaches the pedestal surface side at the same distance. Therefore, it is desirable that the connection part be located as far as possible from the insert mounting seat on the rear end side, and the slit should extend as long as possible to the rear end side. It is desirable to be done.

  However, when the insert mounting seat and the slit are formed on the head member that is attached to and detached from the holder tip as described in Patent Document 1, the size of the main body of the head member is limited. The length must be limited. Moreover, in order to attach the head member to the tip of the holder with the fixing screw as described above, an insertion hole for inserting the fixing screw must be formed in the head member main body, and interference with the insertion hole is avoided. Therefore, since the slit length is further limited, it is difficult to ensure the clamp stability of the cutting insert.

  However, in this respect, in the head member of the insert detachable cutting tool described in Patent Document 1, the slit is extended in an oblique straight line so as to avoid such interference with the insertion hole. Since the gap between the slit and the insertion hole is widened, the strength of the head member body is impaired particularly in a portion where the gap is narrow. For example, when the fixing screw is tightened too much, deformation or damage may occur. is there. Moreover, in the head member described in Patent Document 1, the slit extends to a position beyond the insertion hole in the extending direction, and the connection portion is disposed at a position away from the periphery of the insertion hole pressed by the fixing screw. Therefore, when the connecting portion is elastically deformed, the head member body around the connecting portion may also be deformed, and it is difficult to stably clamp the cutting insert.

  The present invention has been made under such a background, and as described above, in the head member that is attached to the tip of the holder of the insert detachable cutting tool by the fixing screw, the fixing screw is inserted into the head member main body. Even if the insertion hole to be formed is formed, the length of the slit is secured and the change in the inclination of the pressing surface when the jaw part is elastically deformed is suppressed and the deformation other than the connection part is suppressed, thereby stabilizing A head member of an insert detachable cutting tool capable of clamping a cutting insert and preventing deformation and damage of the head member body around the insertion hole, and an insert detachable cutting tool equipped with such a head member It is intended to provide.

  In order to solve the above problems and achieve such an object, the head member of the present invention has an insert mounting seat on which a cutting insert having a cutting blade is detachably mounted on the head member main body. A head member of an insert detachable cutting tool which is mounted on the tip of the holder and constitutes an insert detachable cutting tool by screwing a fixing screw inserted into the member main body into the holder, Is formed with an insertion hole through which the fixing screw is inserted, and the insert mounting seat is formed between the pressing surface of one jaw portion and the other jaw portion of the pair of jaw portions formed in the head member body. And is formed so as to open to the front end side of the head member body and extend to the rear end side, and from the rear end of the insert mounting seat to the insertion hole. Further, a slit extending to the rear end side is extended, and this slit has a bent portion extending in a circular arc shape coaxial with the insertion hole while bending to the one jaw portion side at the rear end portion. It is characterized by that. Moreover, the insert detachable cutting tool of the present invention is characterized in that such a head member is attached to the tip of the holder.

  In the head member and insert detachable cutting tool configured as described above, an insertion hole through which the fixing screw is inserted is formed in the head member main body, and a slit is formed from the rear end of the insert mounting seat toward the insertion hole. Even if the slit is extended, the slit further has a bent portion at the rear end thereof that bends to the side of the one jaw where the pressing surface is formed. Can be extended to the end side. And since this bending part is formed so that the said insertion hole may be made into the circular arc shape coaxial, the space | interval with an insertion hole is not produced, but equal thickness is ensured around an insertion hole. Even if the fixing screw is tightened too much, it is possible to prevent the head member body around the insertion hole from being deformed or damaged.

  Further, the bent portion is thus formed in an arc shape coaxial with the insertion hole, so that the rear wall surface of the slit located at the rear end of the bent portion and facing the front end side, and the slit extending direction of the bent portion on the rear wall surface The connecting portion between the rear end surface of the head member main body located on the side is also disposed adjacent to the periphery of the insertion hole. Therefore, when the head member main body is mounted on the head tip, the periphery of the insertion hole is pressed by the fixing screw, so that it is possible to suppress elastic deformation of portions other than the connection portion in the head member main body. It is possible to surely clamp one of the jaws with the connecting portion as a fulcrum and clamp the cutting insert more stably by the pressing surface.

  Even though the bent portion has a circular arc shape coaxial with the insertion hole as described above, and the uniform thickness can be secured around the insertion hole, the central angle of the arc formed by the bent portion is too large. In other words, if the length of the bent portion becomes too long, the portion where the periphery of the insertion hole continues to the head member body is conversely shortened, and there is a possibility that such a portion may be damaged. On the other hand, if this central angle is too small and the length of the bent portion is too short, the slit cannot be extended sufficiently to the rear end side, so this arc-shaped bent portion is the center of the insertion hole. The central angle formed with respect to is preferably in the range of 20 ° to 50 °.

  As described above, according to the present invention, even if the insertion hole for the fixing screw is formed in the head member body, the slit can be extended to the rear end side without interfering with the insertion hole, and the connecting portion can be a fulcrum. When one of the jaws is elastically deformed, it is possible to prevent the inclination of the pressing surface from changing greatly, and the area around this insertion hole is pressed by a fixing screw, so that elasticity other than the connecting part can be obtained. Deformation can be suppressed, and the cutting insert can be clamped stably to improve machining accuracy. Further, even when the periphery of the insertion hole is pressed by the fixing screw in this way, a uniform thickness is ensured between the bent portion and damage and deformation can be prevented.

  FIGS. 1 to 12 show an embodiment of the head member of the present invention. FIGS. 13 to 16 show an embodiment of the insert detachable cutting tool of the present invention to which the head member of this embodiment is mounted. It is shown. The insert detachable cutting tool of this embodiment is an insert detachable turning tool (bite) that performs grooving or parting-off on a rotating work material, and is roughly held by a tool post of a machine tool. The holder 10 has a quadrangular prism shape, the head member 30 of the above-described embodiment that is attached to the tip of the holder 10, and the cutting insert 50 that is clamped to the head member 30.

  The holder 10 is formed of a steel material or the like and has a substantially square prism shape having an upper surface 11 and a lower surface 12 and a pair of side surfaces 13A and 13B facing each other, and a rear end side thereof (upper right side in FIGS. 13 and 15, 14 and 16 is the shank portion 14 extending along the central axis O of the regular quadrangular prism, and the tip side of the holder 10 (the lower left side in FIGS. 13 and 15, and in FIGS. 14 and 16). On the lower right side, a protrusion 15 protruding upward from the upper surface 11 of the holder 10 is formed, and a mounting for mounting the head member 30 on the tip of the holder 10 where the protrusion 15 is formed. A portion 16 is provided.

  The mounting portion 16 is formed in a concave shape so as to cut out a tip surface of the holder 10 and a portion on the side surface 13A side of the tip portion, and is a plane extending in parallel with the one side surface 13A of the holder 10. A first receiving surface 17 having a shape, a second receiving surface 18 extending in a direction orthogonal to the first receiving surface 17 and perpendicular to the axis O and facing the front end side of the holder 10, and the first receiving surface 18 And a third receiving surface 19 having an upward flat surface extending in a direction orthogonal to the second receiving surfaces 17 and 18.

  Among these, the 1st receiving surface 17 is formed so that it may be dented from the one side surface 13A to the other side surface 13B side, and may extend to the upper end of the said protrusion part 15. As shown in FIG. In the present embodiment, three first fixing screw holes 20A to 20C are formed in the first receiving surface 17 in a direction orthogonal to the first receiving surface 17, and are mutually in the axis O direction. As shown in FIG. 13, it is formed so as to open at the position of each vertex of an unequal triangular shape that is flattened up and down and aligned in the front-rear direction of the holder 10.

  The second receiving surface 18 is arranged in a direction orthogonal to the front end side of the first receiving surface 17 in the axis O direction via a chamfered portion, and is recessed toward the rear end side from the front end surface of the protruding portion 15. It is formed so as to form an L shape when viewed from the front end side. Two second fixing screw holes 21 </ b> A and 21 </ b> B, which are also formed in the second receiving surface 18 in a direction orthogonal to the second receiving surface 18, are orthogonal to the axis O and parallel to the first receiving surface 17. In this embodiment, the holders 10 are opened side by side in the vertical direction.

  Further, the third receiving surface 19 is disposed between the first receiving surface 17 that is recessed toward the other side surface 13 </ b> B and the side surface facing the one side surface 13 </ b> A side of the holder 10 tip, and is orthogonal to the first receiving surface 17. The third receiving surface 19 extends in the direction orthogonal to the second receiving surface 18 via the chamfered portion at the tip end side thereof. The mounting portion 16 having a concave shape is formed in a “U” shape whose rear end side opens to the front end side when viewed from the direction facing the one side surface 13A, and the first and third receiving surfaces 17, 19 is extended to the rear end portion, and the first fixing screw hole 20C on the rearmost end side of the first fixing screw holes 20A to 20C is formed in the rear end portion. Yes.

  Of the first fixing screw holes 20A to 20C, the most distal first fixing screw hole 20A and the second fixing screw holes 21A and 21B extend perpendicular to the axis O and parallel to the first receiving surface 17. It arrange | positions so that it may become a respectively different position in a direction, ie, an up-down direction in this embodiment. In the present embodiment, as shown in FIG. 13, the first fixing screw hole 20A on the distal end side is arranged between the two second fixing screw holes 21A and 21B arranged vertically.

  Further, the projecting portion 15 has a clamp screw that is inclined so as to be separated from the first receiving surface 17 at a predetermined angle as it goes downward in a plane orthogonal to the axis O from the upper end portion downward. A hole 22 is formed. A stepped recess 23 that is larger than the clamp screw hole 22 is formed around the upper end opening of the clamp screw hole 22, and one side 13 </ b> A side of the recess 23 has a first receiving surface 17. The first receiving surface 17 is opened so as to intersect with the upper end of the first receiving surface 17. Further, the stepped surface 24 of the recess 23 is perpendicular to the center line of the clamp screw hole 22, and forms an obtuse angle with respect to the first receiving surface 17 so as to gradually recede downward toward the one side surface 13A. Is inclined.

  The head member 30 of this embodiment mounted on the mounting portion 16 of the holder 10 is constituted by a head member main body 31 that is also integrally formed from a steel material or the like. As shown in FIGS. 7 and 8, the head member main body 31 is thicker at the rear end (right side in FIGS. 6 to 9) than the front end (left side in FIGS. 6 to 9). It is set as the multistage substantially flat plate shape.

  At the rear end portion, in the attached state attached to the holder 10, one side surface of the head member body 31 facing the one side surface 13A of the holder 10 (the lower side surface in FIG. 7 and the upper side in FIG. 8). The side surface 31A and the other side surface (the upper side surface in FIG. 7 and the lower side surface in FIG. 8) 31B are arranged in parallel. However, as shown in FIGS. 7 and 8, the head member main body 31 is flat when viewed from above and below in the attached state, with the one side surface 31 </ b> A extending in the direction of the axis O (front-rear direction). The rear end portion of the other side surface 31B protrudes one step toward the other side surface 13B of the holder 10 with respect to the tip portion.

  Further, from the leading edge of the rear end portion of the projecting other side surface 31B to the lower end surface 31C of the rear end portion, as shown in FIGS. 5 and 11, a projecting wall portion 31D having an L-shaped flat plate shape, It is also formed integrally with the head member main body 31, and a back surface 31E facing the rear end side of the protruding wall portion 31D extends in a direction perpendicular to the axis O in the mounted state. The other side surface 31B at the rear end portion of the head member main body 31 excluding the projecting wall portion 31C is planar when viewed from above and below.

  On the other hand, at the distal end of the head member body 31 that is one step thinner than the rear end, a pair of jaws (upper jaws) extending toward the distal end along the one side surface 13A of the holder 10 in the attached state. A part 32 and a lower jaw part 33) are formed. Among these, the upper jaw 32 that is one jaw in the present embodiment is provided with a pressing surface 34 that presses an insert 60 described later from above, and the lower jaw 33 that is the other jaw is provided with the above pressing surface. 34, a pedestal surface 35 is provided to be opposed to the insert. In the present embodiment, the pressing surface 34 and the pedestal surface 35 are formed in a concave shape that opens to the front end side and extends to the rear end side as shown in FIG. A mounting seat 36 is formed. As shown in FIG. 10, when viewed from the front end side, the pedestal surface 35 has an inverted convex V shape that protrudes upward, and the pressing surface 34 has a convex V shape that protrudes downward. ing.

  Further, at the back of the insert mounting seat 36 on the rear end side between the pressing surface 34 and the pedestal surface 35, the abutting surface facing the front end side perpendicular to the axis O in the mounting state on the pedestal surface 35 side in the above mounting state. 37 is formed. Further, from between the contact surface 37 and the pressing surface 34, the head member main body 31 penetrates between the side surfaces 31 A and 31 B of the rear end portion perpendicularly to the side surfaces 31 A and 31 B, and the insert mounting seat 36. A slit 38 extending from the rear end further toward the rear end side is formed, and the upper jaw portion 32 is elastically deformed so as to bend toward the lower jaw portion 33 side with a connection portion 39 with the lower jaw portion 33 at the rear end of the slit 38 as a fulcrum. It is possible. The slit 38 extends parallel to the axis O on the distal end side communicating with the insert mounting seat 36.

  Further, as shown in FIGS. 6 and 9, the lower jaw portion 33 protrudes to the front end side from the upper jaw portion 32, and protrudes downward from the lower end surface 31 </ b> C at the rear end portion of the head member body 31 to protrude from the protruding wall. The protruding wall portion 31D is continuous with the lower surface flush with the portion 31D. In addition, the lower end surface 31C at the rear end portion is formed in a plane shape perpendicular to the side surfaces 31A and 31B, and extends in parallel with the axis O in the attached state. Is formed.

  In such a head member 30, the rear end portion of the head member main body 31 is inserted into the concave mounting portion 16 at the tip of the holder 10, and the other side surface 31 B of the rear end portion is connected to the first end of the mounting portion 16. The rear surface 31E of the protruding wall portion 31D is seated on the receiving surface 17 so as to be in close contact with the second receiving surface 18 and the lower end surface 31C of the rear end portion thereof is in close contact with the third receiving surface 19. Here, the first fixing screw holes 20A to 20C and the second fixing screw hole 21A are mounted on the rear end portion of the head member main body 31 and the protruding wall portion 31D in a state where the head member 30 is thus seated. , 21B, three first insertion holes 40A to 40C and two second insertion holes 41A, 41B are formed, respectively.

  These first and second insertion holes 40A to 40C, 41A, and 41B are circular in cross section formed so as to penetrate the rear end portion and the protruding wall portion 31D, respectively, provided that the hole bottom side will be described later. The diameter of the fixing screw 42 is reduced so that the back surface of the head comes into contact. Further, in the state where the head member 30 is seated on the mounting portion 16 as described above, the first insertion holes 40A to 40C are centered on the third receiving surface 19 with respect to the centers of the first fixing screw holes 20A to 20C. The second insertion holes 41A, 41B are centered at the second fixing screw holes 21A, 21B so as to be slightly eccentric obliquely toward the tip side and the upper side of the holder 10 so as to be separated from the second receiving surface 18 side. Is slightly decentered obliquely toward the one side surface 13A and the upper side so as to be separated from the lower surface 12 of the holder 10 and approach the first receiving surface 17.

  Therefore, in the seated state, the fixing screw 42 is inserted into the first and second insertion holes 40A to 40C, 41A, 41B as shown in FIGS. 13 and 14, and as shown in FIGS. 1, the head member 30 is screwed into the second fixing screw holes 20A to 20C, 21A, 21B, so that the other side surface 31B of the rear end portion of the head member body 31 is pressed against the first receiving surface 17 and The rear surface 31E of the wall portion 31D is pressed against the second receiving surface 18, and the lower end surface 31C of the rear end portion is pressed against the third receiving surface 19 to be fixed, and is attached to the mounting portion 16 as in the above attachment state.

  The rear end surface 31F of the head member main body 31 is perpendicular to the side surfaces 31A and 31B, and is downwardly stepped toward the rear end side as shown in FIG. 6 in a side view facing the one side surface 31A. The square-shaped convex part formed by the step part on the most rear end side and the lower end face 31C is open to the above-mentioned front end side on the rear end side of the mounting part 16 among them. The first insertion hole 40C at the end of the first insertion holes 40A to 40C is formed in the convex portion. However, the rear end surface 31F is spaced so as not to contact the wall surface facing the front end side of the mounting portion 16 in the attached state. The most advanced first insertion hole 40A is located closest to the lower end surface 31C among the three insertion holes 40A to 40C, and is opened near the rear surface 31E of the protruding wall portion 31D.

  Furthermore, the first insertion hole 40B located between the first insertion holes 40A and 40C and positioned closest to the upper jaw portion 32 among the three first insertion holes 40A to 40C is one from the convex portion in the side view. It is formed inside the step part on the upper end of the tip, and the distance from the most advanced first insertion hole 40A is larger than the distance from the first insertion hole 40C at the rearmost end. Further, in the same side view, the opening on the one side surface 31A side of the first insertion hole 40B has an upper edge on the lower surface of the slit 38 that extends in parallel to the axis O from the rear end of the insert mounting seat 36. It is arranged so as to touch or intersect the extension line.

  The rear end portion of the slit 38 is a bent portion 38A that is bent so as to extend toward the upper upper jaw portion 32 as it goes toward the rear end side as shown in FIG. The first insertion hole 40 </ b> B located close to the rear end side of the slit 38 is formed in a circular arc shape coaxial with the first insertion hole 40 </ b> B and spaced from the opening of the first insertion hole 40 </ b> B. Therefore, in the present embodiment, a portion between the rear wall surface 38B facing the front end side of the rear end of the bent portion 38A and the rear end surface 31F of the head member main body 31 is the connecting portion 39, and the slit 38 in the bent portion 38A is formed. The extending direction is a tangential direction of the arc formed by the bent portion 38A. In this embodiment, the rear wall surface 38B has a concave curved surface that forms a concave arc or the like in the side view.

  Here, the connecting portion 39 is located in the vicinity of the corner at the top end of the step where the first insertion hole 40B is formed, and is located immediately above the first insertion hole 40B. In the form, the upper jaw portion 32 is arranged on a line extending to the rear end side of the pressing surface 34 or at a slightly higher position. The radial width of the arc in the bent portion 38A is slightly larger than the width of the slit 38 extending parallel to the axis O.

  Further, the rear wall surface 38B of the slit 38 facing the front end side of the bent portion 38A is directed toward the front end side as it goes from the one side surface 31A side of the head member body 31 to the other side surface 31B side as shown in FIG. Thus, the connecting portion 39 formed between the rear wall surface 38 and the rear end surface 31F of the head member main body 31 perpendicular to the side surfaces 31A and 31B is extended as described above. As shown in FIG. 12, the width in the direction is formed so as to gradually increase from one side surface 31A side to the other side surface 31B side.

  In the present embodiment, the width of the connecting portion 39 in the extending direction is along the extending direction (tangential direction) of the rear wall 38B at the bent portion 38A at the rear end of the slit 38 as shown in FIG. In the AA cross section, as shown in FIG. 12, it is formed in a trapezoidal shape that becomes wider toward the separation direction at a constant rate. Here, in this cross section, the rear wall surface 38B and the rear end surface 31F are formed in a direction intersecting at an angle θ within the range of 5 ° to 15 ° as shown in FIG.

  On the other hand, the upper jaw portion 32 is formed with a counterbore portion 43 that opens to the upper surface and the other side surface 31B on the tip side of the connection portion 39, and the counterbore portion 43 is in the attached state. The holder 10 communicates with the concave portion 23 opened on the upper surface of the protruding portion 15, and is inclined so as to form a circular cross section with the center line of the clamp screw hole 22 as the center. Further, the bottom face 43A of the spot facing portion 43 is formed in an arc shape as shown in FIG. 7, and gradually recedes downward toward the one side surface 31A side and the rear end side of the head member body 31. The other side surface 31B is inclined at an acute angle, and is arranged so as to protrude one step from the stepped surface 24 of the recess 23 toward the center line direction of the clamp screw hole 22 in the attached state.

  In the head member 30 of the present embodiment, the recesses 44 that are recessed from the side surfaces 31A and 31B that are planar in the top and bottom view as described above are formed on the side surfaces 31A and 31B of the head member main body 31. ing. For example, as shown in FIG. 12, the recess 44 has an inner wall surface 45 that intersects the side surfaces 31 </ b> A and 31 </ b> B at an angle and continues around the inner periphery of the recess 44. Are formed so as to have a bottom surface 46 parallel to the side surfaces 31A and 31B intersecting and connecting at an angle without passing through the head member main body 31, and the front end surface of the head member main body 31 or the like. The rear end surface 31F, the upper surface, the lower end surface 31C, the slit 38 and the first insertion holes 40A to 40C are not opened, and the recesses 44 are not communicated with each other.

  Here, a plurality of recesses 44 are formed in the head member main body 31, and one side surface 31A facing the front side (one side surface 13A side of the holder 10) and the back side (first side of the mounting portion 16) in the mounted state. The recess 44 is formed on both the other side surface 31B facing the receiving surface 17) side, and a plurality of recesses 44 are formed on each of the side surfaces 31A and 31B. However, in these front and back side surfaces 31A and 31B, the recess 44 is formed only in the rear end portion which is thicker in one step in the present embodiment, and the front end portion and the protruding wall where the upper and lower jaw portions 32 and 33 are formed. The portion 31C is not formed.

  Among these, five recesses 44A to 44E are formed in the one side surface 31A on the front side as shown in FIG. 6, and a part (one in this embodiment) of the first recesses 44A is formed. Is formed on the upper jaw 32 side above the slit 38. The inner wall surface 45 of the recess 44A extends at a substantially constant interval between the slit 38 including the bent portion 38A and the upper surface and the rear end surface 31F of the head member main body 31. Inclined straight to the tip side toward the lower side, the lower part is connected to the tip of the upper part, extends downward so as to incline and recede toward the rear end side, and continues around the circumference .

  Further, the remaining second to fifth recesses 44B to 44E formed on the lower jaw 33 side below the slit 38 are the second recesses 44B on the distal end side between the first insertion hole 40A and the slit 38. A third recess 44C is formed on the upper side and a fourth recess 44D is formed on the lower side between the first and second insertion holes 40A and 40B. A fifth recess 44E is formed on the tip side of the third insertion hole 40C below the hole 40B. The second to fifth recesses 44B to 44E also have a substantially constant interval between the slit 38, the opening of the first to third insertion holes 40A to 40C and the lower end surface 31C. Also, the interval between the adjacent recesses 44B to 44E is slightly large, but is also constant.

  The portions between the adjacent recesses 44B to 44E are the first portion between the second and third recesses 44B and 44C and the portion between the third and fourth recesses 44C and 44D. While extending radially from the insertion hole 40A, a portion between the third and fourth recesses 44C and 44D and a portion between the fourth and fifth recesses 44D and 44E also extend radially from the second insertion hole 40B. It is formed as follows. However, the portion between each of the second to fourth recesses 44B to 44D slightly protrudes below the rear end of the holder 10 in the mounted state, while between the fourth and fifth recesses 44D and 44E. This portion is curved so as to be slightly convex toward the tip side. Further, the inner wall surface 45 on the front end side of the second recess 44B protrudes upward toward the rear end side along the extended line of the convex curve formed by the lower portion on the front end side of the first recess 44A. It extends so as to recede while being curved.

  On the other hand, below the slit 38 on the other side surface 31B on the back side, as shown in FIG. 9, the upper sixth recess 44F between the first and second insertion holes 40A, 40B and the lower seventh The three recesses 44F to 44H of the eighth recess 44H on the tip side of the third insertion hole 40C below the recess 44G and the second insertion hole 40B are also the slit 38 and the first to third insertion holes. It is formed with a substantially constant gap between the openings 40A to 40C and the lower end surface 31C. Further, the portion between the adjacent sixth and seventh recesses 44F and 44G extends radially from the first insertion hole 40A, and the portion between the sixth and seventh recesses 44F and 44G and the seventh and seventh recesses 44F and 44G. The portion between the eight recesses 44G and 44H extends radially from the second insertion hole 40B.

  However, among these, the portion between the sixth and seventh recesses 44F, 44G extends straight with a constant width so as to connect the first and second insertion holes 40A, 40B in a straight line, while the seventh, The portion between the eighth recesses 44G and 44H is inclined so that the inner wall surface 45 of the seventh recess 44G is directed toward the distal end side from the second insertion hole 40B toward the lower end surface 31C, and the width gradually increases. It is formed to be wide. As described above, in this embodiment, the front and back side surfaces 31A and 31B are formed so that the shape and number of the recesses 44 are different from each other, and the side surfaces 31A and 31B are particularly viewed from the direction facing the side surfaces 31A and 31B. In this case, all the recesses 44 have different shapes without matching each other.

  Further, in the present embodiment, the depths of the recesses 44 from the side surfaces 31A and 31B, that is, the depths from the side surfaces 31A and 31B to the bottom surface 46 of the recess 44 are different. Specifically, as shown in FIG. 12, the depth of the recess from the side surface 31A of the first to fifth recesses 44A to 44E formed on the one side surface 31A on the front side is set on the other side surface 31B on the back side. The depths of the formed sixth to eighth recesses 44F to 44H are significantly shallower than the recess depth from the side surface 31B. However, in the recesses 44A to 44E and the recesses 44F to 44H on the side surfaces 31A and 31B, respectively. The depths of the recesses are made equal. As a result, the portions between the bottom surfaces 46 of the recesses 44A to 44E and the bottom surfaces 46 of the recesses 44F to 44H on both side surfaces 31A and 31B are made thin at the tip of the head member body 31 as shown in FIG. Further, the lower jaw 33 is formed so as to be arranged at substantially the center of the thickness.

  The head member 30 having such a recess 44 is formed by cutting the head member main body 31 in which the recess 44 is not formed from a steel material or the like and then forming the recess 44 by an end mill or the like. However, for example, a divided material obtained by reversing the shape of the head member main body 31 is made of a material made by mixing a raw material powder of a steel material used as the head member main body 31 and a binder such as a resin to have fluidity. It can also be manufactured by MIM (Metal Injection Molding) method, in which the binder is removed by heating after injection molding in the mold and the raw material fine powder is sintered. When manufactured by such MIM method, the inner wall surface 45 of the recess 44 is given a draft angle that inclines outward from the bottom surface 46 toward the side surfaces 31A and 31B.

  In addition, even when manufactured by the MIM method or manufactured by cutting, the head member body 31 manufactured is urged to harden the surface by injecting hard small spherical particles on the surface thereof. It is desirable that peening is applied.

  The grooving / cutting-off cutting insert 50 attached to the insert mounting seat 36 of the head member 30 has an insert main body 51 formed into a square bar shape whose outer shape is substantially square in cross section by a hard material such as cemented carbide. However, the lower surface and the central portion of the upper surface are formed in a V-shaped cross section so that the V-shaped bisectors coincide with the pressing surface 34 and the pedestal surface 35 having a convex V-shaped cross section. Can be contacted. In addition, rake faces are formed at both ends of the upper surface at positions one step backward from the center, and cutting edges 52 used for grooving and parting off are formed at both edges of these rake faces. ing.

  Such a cutting insert 50 is directed to the head member 30 in the above-mentioned mounting state, with its one cutting edge 52 facing the tip side, and a concave V-shaped lower surface and an upper surface central portion between the pedestal surface 35 and the pressing surface. 34 is inserted into the insert mounting seat 36 from the front end side so as to face the end 34, and when the end surface of the insert main body 51 facing the rear end side contacts the contact surface 37, it is positioned in the axis O direction.

  Further, as shown in FIGS. 13 and 14, the clamp screw 47 is screwed into the clamp screw hole 22 formed in the protruding portion 15 of the holder 10, so that the head of the clamp screw 47 is seated on the head member body 31. The clamp screw 47 engages with the upper jaw portion 32 in contact with the bottom surface 43A of the bore portion 43, and then the upper jaw portion 32 is pressed in the direction in which the clamp screw hole 22 is drilled, with the connecting portion 39 as a fulcrum. It is elastically deformed so as to bend toward the portion 33 side, the pressing surface 34 presses the insert body 51 toward the pedestal surface 35 side, and the cutting insert 50 is clamped, whereby the insert detachable cutting tool of this embodiment is configured.

  Therefore, in the head member 30 configured as described above and the insert detachable cutting tool equipped with the head member 30, the slit 38 is first inserted from the rear end of the insert mounting seat 36 to attach the head member main body 31 to the tip of the holder 10. Even if the slit 38 extends toward the hole (first insertion hole 40B), the rear end of the slit 38 is a bent portion 38A that bends toward the upper jaw 32 where the pressing surface 34 is formed. The slit 38 can be extended to the rear end side while avoiding interference with the one insertion hole 40B. For this reason, the position of the connecting portion 39 with the lower jaw 33 serving as a fulcrum for elastic deformation of the upper jaw 32 can also be arranged on the rear end side of the head member body 31, and the pressing surface 34 during elastic deformation. Can be prevented from tilting greatly.

  Further, the bent portion 38A is formed to have an arc shape coaxial with the first insertion hole 40B. Therefore, the fixing screw 42 is also inserted into the connecting portion 39 located at the rear end of the bent portion 38A. And being arranged on the extension of the arc around the first insertion hole 40B to be pressed to the first receiving surface 17 side of the holder 10 by being screwed into the first fixing screw hole 20B. Become. Then, when the periphery of the first insertion hole 40B is pressed by the fixing screw 42 in this way, when the upper jaw portion 32 is elastically deformed to bend toward the lower jaw portion 33 with the connecting portion 39 as a fulcrum, deformation occurs in other portions. Therefore, it is possible to surely promote elastic deformation with the connecting portion 39 as a fulcrum.

  Therefore, according to the head member 30 and the insert detachable cutting tool configured as described above, the upper jaw portion 32 can be elastically deformed without causing a large change in inclination on the pressing surface 34 with the connection portion 39 as a fulcrum. Therefore, the cutting insert 50 can be stably pressed and clamped to the pedestal surface 35 side while the pressing surface 34 is in close contact with the center of the upper surface of the insert body 51. For this reason, it is possible to prevent the insert main body 51 from rattling during cutting, and to improve the processing accuracy of grooving and parting-off by the cutting blade 52. Further, by forming the bent portion 38A in this way, the slit 38 can be extended from the rear end of the insert mounting seat 36 regardless of the position of the insertion hole, so that the degree of freedom in designing the head member 30 is improved. In addition, the head member body 31 can be made compact.

  Further, the bent portion 38A is made coaxial with the first insertion hole 40B in this way, so that an arc plate shape having a uniform thickness over the circumferential direction is provided between the bent portion 38A and the first insertion hole 40B. Thus, there is no occurrence of a gap between the slit and the insertion hole as in the case where the linearly extending slit is extended. For this reason, even if the fixing screw 42 inserted into the first insertion hole 40B as described above is screwed too much into the first fixing screw hole 20B of the holder 10, the head member main body 31 is not deformed between the slit 38 and the head member body 31. It is possible to prevent the occurrence of damage, and conversely, in some cases, by pressing and fixing the periphery of the first insertion hole 40B with a stronger pressing force, the elasticity of the connection portion 39 as a fulcrum is further ensured. Deformation can also be encouraged.

  However, even if a uniform thick arc-shaped plate-like portion having no width is formed between the bent portion 38A of the slit 38 and the first insertion hole 40B, the bent portion 38A is too long in the circumferential direction. Then, the portion that continues to the head member main body 31 around the first insertion hole 40B is shortened, and the strength may be insufficient to cause damage. On the other hand, if the bent portion 38A is too short, the above-described effect cannot be obtained. Therefore, the bent portion 38A having an arc shape coaxial with the first insertion hole 40B is formed in the first insertion hole as shown in FIG. It is desirable that the central angle α with respect to the center of 40B is in the range of 20 ° to 50 °.

  In the present embodiment, as described above, the rear wall surface 38B is formed so as to be inclined toward the front end side from the one side surface 31A side of the head member main body 31 toward the other side surface 31B side. When the wall surface 38B is inclined, the central angle α is the edge on the side where the rear wall surface 38B is inclined from the edge on the front end side of the bent portion 38A toward the rear end as shown in FIG. The wall surface 38 </ b> B has a central angle up to the edge of the side surface 31 </ b> A.

  By the way, in the present embodiment, when the cutting insert 50 is clamped, the clamp screw 47 is screwed into the clamp screw hole 22 formed obliquely with respect to the first receiving surface 17 in the protrusion 15 at the tip of the holder 10. When the head of the clamp screw 47 presses the inclined bottom surface 43A of the counterbore 43 of the head member body 31, the upper jaw 32 is elastically deformed with the connecting portion 39 as a fulcrum as described above. . Therefore, the upper jaw portion 32 receives a pressing force so that the pressing surface 34 bends to the pedestal surface 35, and the upper jaw portion 32 falls to the other side surface 13 </ b> B side of the holder 10 around the connection portion 39 as viewed from the distal end side. The pressing force is also received in the direction of inclination.

  However, the first receiving surface 17 of the mounting portion 16 is disposed on the side on which the upper jaw portion 32 falls in this way and is brought into close contact with the other side surface 31B of the head member main body 31 in the upper jaw portion 32. In this embodiment, the rear wall 38B facing the front end of the rear end of the bent portion 38A of the slit 38 has one side surface of the head member body 31 as described above. The connecting portion 39 between the rear end surface 31F perpendicular to the side surfaces 31A and 31B is connected to the one side surface 31A. The upper jaw 32 is formed so as to gradually become thicker toward the other side surface 31B on the side where the upper jaw 32 falls.

  Accordingly, the upper jaw portion 32 is not easily deformed to the other side surface 31B side where the connection portion 39 is made thick, and thus receives the force that falls to the other side surface 13B side of the holder 10 as described above. In addition, it is possible to prevent a situation in which the upper jaw portion 32 is inclined and presses the cutting insert 50. For example, the pressing surface 34 and the pedestal surface 35 have a convex V-shaped cross section as in the present embodiment, and the insert body 51. When the lower surface and the central portion of the upper surface are formed in a concave V-shape in cross section, the cutting insert 50 can be pressed and clamped in a state where these V-shaped bisectors are exactly matched. For this reason, the cutting insert 50 can be clamped reliably and firmly, and it becomes possible to prevent the situation where the insert main body 51 is rattled by the cutting load and the processing accuracy is impaired.

  In this embodiment, the rear end surface 31F of the head member main body 31 is made perpendicular to the side surfaces 31A and 31B as described above, and the rear wall surface 38B of the bent portion 38A at the rear end of the slit 38 is inclined so that the connection is established. As described above, the portion 39 gradually increases in thickness toward the side where the upper jaw portion 32 falls, but conversely, the rear wall surface 38B is perpendicular to the side surfaces 31A and 31B, and the rear end surface 31F is the side surface. The rear end side may be inclined toward the side surface 31B from the 31A side, and both the rear wall surface 38B and the rear end surface 31F may be inclined so as to be spaced apart from the side surface 31A side toward the side surface 31B. Also good.

  However, by inclining the rear wall surface 38B and the rear end surface 31F in this manner, the pressing force acts on the upper jaw portion 32 by the thickness of the connecting portion 39 on the other side surface 31B side of the head member main body 31, that is, by the clamp screw 47. When the inclination angle θ shown in FIG. 12 is too large, the pressing surface 34 is a pedestal depending on the width of the connecting portion 39 between the rear wall surface 38B and the rear end surface 31F. There is a possibility that it is difficult to bend the upper jaw 32 so as to approach the surface 35. On the other hand, even if the inclination angle θ is too small, the above-described effect is not reliably achieved. Therefore, as shown in FIG. 12, the inclination angle θ is the extending direction of the bent portion 38A on the rear wall 38B, that is, the bent portion. It is desirable that the angle is set to 5 ° to 15 ° in the cross section along the tangential direction of the arc formed by the portion 38A.

  On the other hand, in the head member 30 of the present embodiment, the above-described recess 44 is formed on the side surfaces 31A and 31B. The recess 44 includes an inner wall surface 45 continuous around the circumference, and the inner wall surface. 45 has a bottom surface 46 continuous over the entire circumference thereof, so that the bottom surface of the recess 44 is between the recess 44 and the upper surface, the rear end surface 31F, and the lower end surface 31C of the head member body 31. At least two rib-like portions that stand and protrude with respect to 46 are formed on both sides of the recess 44. In particular, in the present embodiment, since the plurality of recesses 44A to 44H are formed on the side surfaces 31A and 31B, such rib-shaped portions are also formed between the inner wall surfaces 45 of the adjacent recesses 44B to 44E. The

  Therefore, even if vibration is generated in the insert main body 51 from the cutting edge 52 directed toward the distal end side of the cutting insert 50 during the above-described grooving / parting-off processing, this vibration propagates from the head member 30 to the holder 10. Sometimes it is dispersed through such a plurality of rib-like parts and does not directly propagate to the holder 10, so that such vibration concentrates and chatter vibration or the like occurs in the holder 10. Can be suppressed. Moreover, since the weight of the head member main body 31 can be reduced by the recess 44, vibration itself is easily damped, and it is possible to suppress the occurrence of chatter vibration.

  For this reason, according to the present embodiment, even if the protruding amount of the cutting blade 52 at the time of grooving / parting-off processing is increased, the cutting operation is hindered by this chatter vibration or the processing accuracy is deteriorated. Therefore, it is possible to stably and smoothly perform high-precision and high-quality cutting. Moreover, since the surface area of the head member main body 31 is increased by forming the recess 44 in this way, the cutting heat generated in the cutting insert 50 during cutting can be quickly dissipated through the head member 30, for example. In dry cutting or the like, it is also possible to prevent the cutting insert 50 from being thermally damaged or causing chip welding.

  On the other hand, even if the thickness of the head member main body 31 is reduced by forming such a recess 44, the recess 44 is the first and second insertion holes in the head member 30 of the present embodiment. 40A to 40C, 41A, and 41B do not penetrate the head member body 31, and are positioned between the side surfaces 31A and 31B of the head member body 31 such as the insert mounting seat 36, the slit 38, or the counterbore portion 43. Since the rib-shaped portion as described above is formed around the recess 44 without opening in the peripheral end surface (front end surface, rear end surface 31F, upper surface, lower end surface 31C), the head member main body 31 The strength and rigidity are not significantly impaired. In particular, by performing shot peening on the head member main body 31 as described above, the strength and rigidity of the head member 30 can be more reliably improved and more stable cutting can be achieved.

  However, even when the rib-like portion is formed or shot peened as described above, if the total volume of the recess 44 becomes too large, the strength and rigidity of the head member main body 31 are inevitably lowered. . On the other hand, even if the total volume of the recess 44 is too small, the effects such as the above-described vibration prevention and cutting heat dissipation are insufficient. Therefore, the recess 44 is formed in the total volume of the recess 44. It is desirable to be in the range of 2% to 15% of the volume of the head member main body 31 that is not present. In this embodiment, the recess 44 has a bottom surface 46 parallel to the side surfaces 31A and 31B intersecting the inner wall surface 45 at an angle, but the inner wall surface 45 and the bottom surface 46 are smoothly connected to each other. For example, it may be a concave spherical recess that forms a curved surface.

  In the present embodiment, as described above, the recesses 44A to 44E and the recesses 44F to 44H are formed on the front and back side surfaces 31A and 31B of the one side surface 31A and the other side surface 31B of the head member body 31, respectively. These recesses 44 have different shapes when viewed from the direction facing the side surfaces 31A and 31B, that is, when viewed from either side of the side surfaces 31A and 31B. For this reason, since the rib-shaped portions formed around the recesses 44A to 44E and the recesses 44F to 44H are also different from each other, vibrations can be more reliably dispersed and vibrations can be mutually dispersed. It is also possible to cancel each other, and it is possible to more effectively suppress the propagation of vibration to the holder 10.

  Further, in the present embodiment, the recesses 44A to 44E and the recesses 44F to 44H formed on the front and back side surfaces 31A and 31B are different from each other in depth from the side surfaces 31A and 31B. Since the height of the rib-like portion is also different on the front and back sides, the dispersed vibrations can be canceled more reliably. In the present embodiment, the recesses 44A to 44E on one side surface 31A and the recesses 44F to 44H on the other side surface 31B have the same recess depth, but the recess 44 is the head member main body 31. If it does not penetrate, the recessed part 44 from which a dent depth differs in at least one of each side surface 31A, 31B may be formed.

1 is a perspective view of a head member 30 according to an embodiment of the present invention, as viewed from the upper end side and one side surface 31A side of a head member body 31. FIG. FIG. 2 is a perspective view of the embodiment shown in FIG. 1 as viewed from the upper end side and the other side surface 31B side of the head member body 31. It is the perspective view which looked at the embodiment shown in Drawing 1 from the tip lower part side and one side 31A side. It is the perspective view which looked at the embodiment shown in Drawing 1 from the tip lower side and the other side 31B side. It is the perspective view which looked at the embodiment shown in Drawing 1 from the rear end lower side and the other side 31B side. It is the side view which looked at embodiment shown in FIG. 1 from the one side 31A side. It is the top view (top view) which looked at embodiment shown in FIG. 1 from the upper surface side. It is the bottom view (bottom view) which looked at embodiment shown in FIG. 1 from the lower end surface 31C side. It is the side view which looked at the embodiment shown in Drawing 1 from the other side 31B side. It is the front view which looked at the embodiment shown in Drawing 1 from the tip side. It is the rear view which looked at embodiment shown in FIG. 1 from the rear end surface 31F side. It is AA sectional drawing in FIG. FIG. 2 is an exploded perspective view of an insert detachable cutting tool according to an embodiment of the present invention to which the head member 30 shown in FIG. 1 is mounted as viewed from the upper end side and the one side surface 13A side of the holder 10. It is the disassembled perspective view which looked at the embodiment shown in FIG. 13 from the tip upper side and the other side surface 13B side of the holder 10. It is the assembly perspective view which looked at the embodiment shown in Drawing 13 with which head member 30 and cutting insert 50 were installed from the tip upper part side and one side 13A side. It is the assembly perspective view which looked at embodiment shown in FIG. 13 with which the head member 30 and the cutting insert 50 were mounted | worn from the front-end | tip upper side and the other side surface 13B side.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Holder 16 Mounting part 22 Clamp screw hole 30 Head member 31 Head member main body 31A One side surface 31B of the head member main body 31 The other side surface 31F of the head member main body 31 The rear end surface 32 of the head member main body 32 The upper jaw part 33 The lower jaw part 34 Press Surface 35 Base surface 36 Insert mounting seat 38 Slit 38A Bent part 38B Rear wall surface of the bent part 38A 39 Connection part 40A to 40C First insertion hole 42 Fixing screw 43 Counterbore part 44 (44A to 44H) Recess 45 Recess 45 Inner wall 46 Bottom surface of recess 44 47 Clamp screw 50 Cutting insert 51 Insert body 52 Cutting edge O Axis of holder 10 θ The rear wall 38B and the rear end surface 31F are in a cross section along the extending direction of the slit 38 in the rear wall 38B. The angle α formed by the bent portion 38A is opposed to the center of the first insertion hole 40B. Central angle eggplant Te

Claims (3)

  An insert mounting seat to which a cutting insert having a cutting blade is detachably attached is formed on the head member main body, and a fixing screw inserted through the head member main body is screwed into the holder to be attached to the tip of the holder. The insert member detachable cutting tool is a head member of the insert detachable cutting tool, wherein the head member main body is formed with an insertion hole through which the fixing screw is inserted, and the insert mounting seat is Of the pair of jaws formed on the head member body, the pressing surface of one jaw part and the pedestal surface of the other jaw part are configured to open to the front end side of the head member body and extend to the rear end side. A slit extending from the rear end of the insert mounting seat toward the insertion hole is further extended toward the rear end side. The insert-indexable tool of the head member, characterized in that it has a bent portion that extends at the insertion hole coaxial with the arc-shaped with bent on one jaw side of the.   The head member of an insert detachable cutting tool according to claim 1, wherein a central angle of an arc formed by the bent portion is in a range of 20 ° to 50 °.   3. The insert detachable cutting tool according to claim 1, wherein the head member of the insert detachable cutting tool is attached to the tip of the holder.

Images