JP2009006443A - Cutting insert, cutting tool and cutting method using the tool - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cutting insert having an upper surface making a rake face, restraint applied on the side surface side of which is strong and stable in the working direction, which can be changed from the side surface side and which is simple in a clamping structure. <P>SOLUTION: This cutting insert is restrained on a holder by a fixing member, a main body part of the cutting insert has at least one corner cutting blade positioned on a corner part as seen at an upper surface and a through hole provided so that both ends are opened to a side surface of the main body part and pass through the main body part, and the through hole has a first opening part opened along two surfaces of at least either one of two side surfaces adjacent to each other of the main body part restrained by the holder and a side surface adjacent to the other side surface side and a second opening part proximate to the corner cutting blade and at least one part of which is pressurized by the fixing member. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a cutting insert used for cutting.

  A turning tool used for outer diameter machining or the like is used by attaching a cutting insert to a holder by various clamping methods. When such a turning tool is used for small diameter machining and automatic lathes, the size of the cutting insert and the holder is small because the tool itself is small, and there is also a work space for exchanging the cutting insert. Narrow. In particular, when a small work material is cut into a complicated shape by a small-diameter NC lathe or the like and finished, a plurality of turning tools are arranged around the work material, so the upper surface side that forms the rake face of the cutting insert The remaining work space will be very narrow. Therefore, high workability at the time of cutting insert replacement is required for a clamp method used for a turning tool for small-diameter machining and used on an automatic lathe or the like.

Therefore, in Patent Document 1, a cavity that communicates with the through hole of the cutting insert and a screw hole that intersects the cavity and opens on the side surface of the holder are formed in the holder, and one end of the lever disposed in the cavity is A cutting tool is disclosed in which the other end of the lever is engaged with the wall surface of the through hole of the cutting insert and is restrained by the holder by being pushed down by a set screw screwed into the screw hole. With such a configuration, the cutting insert can be replaced from the side surface direction, and the cutting insert can be easily replaced.
Japanese Patent Laid-Open No. 07-15204

  However, since the cutting tool described in Patent Document 1 does not directly operate the lever that presses the cutting insert to clamp the cutting insert, the direction in which the cutting insert should be pressed does not match the direction in which the lever is retracted. However, there is a problem that the clamping efficiency is lowered. Therefore, when the restraining force applied to the side surface of the cutting insert is weak, the cutting insert is displaced in a so-called dimensional direction, and there is a problem that processing accuracy is deteriorated. This problem is a particularly serious problem in a turning tool for small diameter machining used in a lathe.

  Further, in a turning tool used for end face machining and copying along with outer diameter machining, the direction of the cutting force applied during cutting differs between outer diameter machining, end face machining, and copying. Therefore, in such a tool, it is necessary to exert the force which restrains the cutting insert corresponding to the cutting force applied at the time of each processing form by one clamp method. On the other hand, since the cutting tool described in Patent Document 1 uses a lever to constrain the cutting insert, there is a problem in that the direction in which the restraining force acts is not stable, in addition to a decrease in clamping efficiency. Therefore, when the cutting method of the cutting tool of Patent Document 1 is applied to a turning tool that can be used in a plurality of machining forms that receive cutting force from a plurality of directions, the strong corresponding to the cutting force in different directions applied in each machining form. There was a problem that the binding force could not be obtained, and the cutting insert was displaced in the dimensional direction at any machining mode.

  Furthermore, with the recent diversification of machining forms for cutting small work materials into complex shapes, there is a need for further miniaturization of cutting tools. Since the number of points is large and the clamp structure is complicated, there is a problem that the cutting insert and the holder cannot be downsized.

  Furthermore, since the cutting tool described in Patent Document 1 has a complicated clamp structure, it is difficult to process the holder, and there is a problem that the processing cost of the holder increases.

  Accordingly, the present invention has been made to solve such problems of the prior art, and the binding force applied to the side surface of the cutting insert having the upper surface forming the rake face is strong and the working direction is stable. Accordingly, an object of the present invention is to provide a cutting insert that has high clamping efficiency, can be replaced from the side, and has a simple clamping structure.

  In order to solve the above-described problem, the cutting insert of the present invention includes a main body having an upper and lower surface and a plurality of side surfaces, and at least two side surfaces of the plurality of side surfaces are constrained to a holder by a fixing member. A cutting insert, wherein the main body portion is located at at least one corner portion in a top view and is provided with a corner cutting edge provided at a crossing portion between the upper surface and the side surface, and both ends are open to the side surface. A through-hole through which the fixing member is inserted, and the through-hole is at least one of the two side surfaces constrained by the holder among the plurality of side surfaces A first opening that opens over two sides of the side and the side that is adjacent to the other side of the side, and a second opening that is close to the corner cutting edge And wherein the Rukoto.

  With such a configuration, by operating the fixing member that directly presses the cutting insert from the side surface side of the main body portion of the cutting insert, both of the two side surfaces that serve as the constraining surfaces to the holder are stable and have a strong restraining force. The clamp structure restrained by the holder can be realized, and the displacement of the cutting insert in the dimensional direction can be suppressed. In addition, since the clamp structure is simple, the cutting insert and the holder can be downsized. Therefore, the obtained cutting insert is small and has high clamping efficiency, so the work space on the upper surface side that forms the rake face is narrow, and small diameter machining used in automatic lathes etc. that require a strong clamping force in the side surface direction. It can be suitably used for a tool for use.

  Further, a pressing portion located on the second opening side of the inner wall of the through hole and pressed by the fixing member is close to the corner cutting edge among the two side surfaces constrained by the holder in a top view. The through hole is positioned on the side close to the corner cutting edge with respect to a plane substantially perpendicular to the lower surface passing through a virtual straight line connecting the midpoint of the side surface to the center of the inscribed circle of the main body. A pressing portion located on the second opening side pressed by the fixing member on the inner wall is close to a corner cutting edge that receives a large cutting force during cutting with respect to a plane that passes through the virtual straight line and is substantially perpendicular to the lower surface. Because it is located on the side, it is pressed by the fixing member at a position close to the corner cutting edge to which a larger cutting force is applied and at a position far from the side surface restrained by the holder, so that the clamping force on the side surface is increased. Masui.

  Further, the main body portion has a substantially n-square shape (n ≧ 4: n is a natural number) in a top view, and is positioned on the second opening side of the inner wall of the through hole and is pressed by the fixing member. The pressing part is directed to a plane substantially perpendicular to the lower surface through an imaginary straight line connecting ends close to the corner cutting edge among both end portions of the two side surfaces constrained by the holder in a top view. The clamp is applied to the side surface because it is pressed by the fixing member at a position closer to the corner cutting blade and at a position farther from the side surface restrained by the holder. It is desirable because the power can be further improved.

  In addition, a pressing portion located on the second opening side of the inner wall of the through-hole and pressed by the fixing member passes through a virtual inscribed circle of the main body portion in a top view and is in a curved surface substantially perpendicular to the lower surface. Since the fixing member is pressed by the fixing member at a position close to the corner cutting blade and at a position far from the side surface restrained by the holder, it is suppressed that the fixing member protrudes from the main body portion. This is desirable because interference with the work material can be suppressed and a strong clamping force is applied to the side surface.

  Furthermore, since the axis of the through hole is provided so as to bisect the angle formed by the two side surfaces, an equal restraining force can be applied to the two side surfaces constrained by the holder. This is desirable because the effect of suppressing the shift is increased.

  Further, in both processing modes in which the axis of the through hole bisects the corner of the one corner portion where the corner cutting edge is provided, the cutting force is applied in different directions such as outer diameter processing and end surface processing. Are desirable because each can obtain an effect of suppressing the displacement of the cutting insert in the dimension direction.

  Furthermore, the main body has a symmetrical shape with a straight line perpendicular to the axis of the through hole as the axis of symmetry when viewed from above, so that the strength of the cutting insert is increased, and further miniaturization can be achieved. It can use suitably for the tool for small diameter processing used.

  Moreover, in order to solve the said subject, the cutting tool of this invention has a fixing member, the cutting insert provided with the main-body part which has an up-and-down surface, and a some side surface, The holder by which this cutting insert is fixed by the said fixing member And the cutting insert is located at at least one corner when viewed from above, and has a corner cutting edge provided at the intersection of the upper surface and the side surface, and both ends of the side surface are the side surfaces. At least one of the two side surfaces of the plurality of side surfaces that are constrained by the holder. A through hole formed on one side and a side adjacent to the side and the other side, and the holder is fixed to the cutting insert. An insert pocket having both a constraining lower surface that contacts the lower surface of the cutting insert and two constraining side surfaces that respectively contact the two side surfaces of the cutting insert, and an axis of the through hole that communicates with the through hole of the cutting insert A screw hole having an axis that is eccentric with respect to the screw member, and the fixing member has a screw part that is screwed into the screw hole of the holder, and a head part that has a larger diameter than the screw part, The fixing member is inserted from the other opening of the two openings of the through hole that opens on the side surface of the cutting insert, and the screw portion of the fixing member is screwed into the screw hole of the holder and fixed. When the head of the member presses the pressing portion located on the other opening side of the inner wall of the through-hole, the lower surface of the cutting insert is moved to the restraining lower surface of the holder. The two sides of the cutting insert, wherein each pressed by the cutting insert into two captive sides of the holder, characterized in that it is fixed to the holder.

  With such a configuration, since the through hole is open on the side surface, the fixing member can be operated from the side surface side, and the through hole is opened over two surfaces including one of the two restrained side surfaces. As a result, a strong restraining force can be applied to both of the two restraining side surfaces. Therefore, even when used in a small-diameter machining tool using an automatic lathe or the like in which the working space on the upper surface side is small and the dimensional accuracy is likely to deteriorate due to the shift in the lateral direction of the cutting insert, the machining accuracy is high and the workability is excellent.

  The pressing portion passes through an imaginary straight line connecting a midpoint of a side surface close to the corner cutting edge of the two side surfaces of the cutting insert in a top view and a center of an inscribed circle of the main body portion. By being located on the side close to the corner cutting edge with respect to a plane substantially perpendicular to the cutting edge, the cutting is performed at a position close to the corner cutting edge where a large cutting force is applied during cutting and at a position far from the restraining side surface of the holder. Since the insert is pressed by the fixing member, the cutting insert is more firmly fixed to the holder, which is desirable because the effect of reducing the displacement of the cutting insert in the dimensional direction is enhanced.

  Further, the main body portion of the cutting insert has a substantially n-square shape (n ≧ 4: n is a natural number) in a top view, and the pressing portion is included in both end portions of the two side surfaces in the top view. By being located closer to the corner cutting edge with respect to a plane substantially perpendicular to the lower surface passing through an imaginary straight line connecting ends close to the corner cutting edge, the position closer to the corner cutting edge. In addition, since the cutting insert is pressed by the fixing member at a position far from the restraining side surface of the holder, the clamping force can be further improved and the dimensional accuracy is increased.

  The holder includes a cutting portion to which the cutting insert is fixed and a gripping portion that is positioned on the rear end side of the cutting portion and is gripped by an external device, and an upper surface of the cutting portion is By being positioned at substantially the same height as the upper surface, the upper surface of the cutting part and the gripping part should be formed at the same height in the holder positioned behind the cutting insert that does not have a hole opening on the upper surface. Thus, in addition to the smooth flow of chips on the upper surface of the cutting insert, the flow of chips also improves on the upper surface of the holder, which is desirable because further chip discharge performance can be improved.

  Furthermore, in order to solve the said subject, the cutting method of the workpiece of this invention has the process of making the cutting tool mentioned above adjoin to the rotating workpiece, and the cutting blade of the said cutting tool on the surface of the said workpiece A step of contacting and cutting the work material; and a step of separating the cutting tool from the work material.

  With such a configuration, the cutting insert can be prevented from shifting in the dimensional direction during cutting, and the cutting insert can be exchanged from the side surface direction of the cutting insert, so that cutting with high processing accuracy and workability is possible. Can be realized.

  According to the cutting insert of the present invention, by operating the fixing member that directly presses the cutting insert from the side surface side of the main body portion, both of the two side surfaces serving as the constraining surfaces to the holder are fixed with a strong constraining force. A clamp structure can be realized and displacement of the cutting insert in the dimensional direction can be suppressed. Therefore, the working space on the upper surface side forming the rake face is narrow, and it can be suitably used as a small-diameter machining tool used in an automatic lathe or the like that requires a strong clamping force in the side surface direction.

  According to the cutting tool of the present invention, the fixing member can be operated from the side surface side of the cutting insert, and a strong restraining force acts on both of the restraining surfaces of the cutting insert to the two holders by the fixing member. Even in small-diameter machining tools using an automatic lathe or the like, in which the working space on the upper surface side is small and the dimensional accuracy is likely to deteriorate due to the displacement of the side surface of the cutting insert, the machining accuracy is high and the workability is excellent.

  According to the cutting method of the work material of the present invention, the clamp structure is easy, the cutting insert can be prevented from shifting in the dimensional direction during the cutting process, and work from the side surface direction of the cutting insert is possible. Therefore, cutting with high machining accuracy and high work efficiency can be realized at low cost.

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

  1 to 5 show an embodiment of the present invention. 1 is an overall perspective view of a cutting insert (hereinafter abbreviated as an insert) 1 according to an embodiment of the present invention, FIG. 2 is a top view of the insert 1 of FIG. 1, and FIGS. It is the side view seen from I direction, the side view seen from II direction of (c) and (a), and the AA sectional view of (d) and (b). FIG. 3 is an overall perspective view of the cutting tool 10 according to an embodiment of the present invention. 4A is a top view of the cutting tool 10 of FIG. 3, FIG. 4B is a side view of the cutting tool 10 viewed from the I direction, and FIG. 4C is a side view of the cutting tool 10 viewed from the II direction of FIG.

  An insert 1 according to an embodiment of the present invention will be described with reference to FIGS. 1 and 2.

  In FIG. 1, an insert 1 includes a main body 2 having an upper and lower surface and a plurality of side surfaces. In the main body, at least a part of the upper surface forms a rake face, and at least a part of a side surface connected to the rake face forms a flank face. And the main-body part 2 is located in the at least 1 corner part C in top view, and the corner cutting edge 5 provided in the crossing part of the upper surface 3 and the side surface 4, and both ends open to a side surface, and a main-body part 2 and a through-hole 6 provided so as to penetrate 2. In the present embodiment, the main body 2 is formed so that the top view has a polygonal shape, specifically, the top view has a rhombus shape.

  The through-hole 6 is a hole through which the fixing member is inserted when attaching the insert 1 to a holder described later, and has a first opening 61 located at one end and a second opening 62 located at the other end. ing. The second opening 62 is close to the corner cutting edge 5 formed at one corner C of the main body 2. The first opening 61 extends over two surfaces of at least one of the two side surfaces (4a, 4b) restrained by the holder and a side surface adjacent to the side surface and the other side surface side. It is formed to open.

  Here, the first opening is configured to open over two side surfaces of at least one of the two side surfaces constrained by the holder and the side surface adjacent to the other side surface side. Divided into two cases. Specifically, as in the present embodiment, when two side surfaces constrained by the holder are provided adjacent to each other among the plurality of side surfaces of the insert 1, the first opening 61 has two adjacent ones. It is formed so as to open over two surfaces of the side surfaces (4a, 4b). And when two side surfaces restrained by a holder are provided without adjoining among a plurality of side surfaces of an insert, that is, two side surfaces restrained by a holder are connected via a side surface not restrained by a holder. The first opening is located between one of the two side surfaces constrained by the holder and the two side surfaces constrained by the holder and adjacent to the one side surface. It forms so that it may open over two surfaces, the side surface which is not restrained (not shown).

  With such a configuration, the through-hole 6 penetrates the main body 2 from one side surface to the other side surface, and the first opening 61 has at least one of the two side surfaces (4a, 4b). And the side surface adjacent to the other side surface side, so that the fixing member can be operated from the side surface side of the main body 2 when the insert 1 is replaced. The restraining force on the holder acts on both of the two side surfaces (4a, 4b), and the working direction is stable and strong. Therefore, when the insert 1 is used for a cutting tool having a narrow work space on the upper surface side of the insert 1 that forms a rake face, such as a cutting tool for small-diameter machining used in an automatic lathe or the like, the working efficiency is increased. A stable restraining force in the lateral direction is obtained, and the shift in the dimensional direction is reduced. As a result, the insert 1 is a cutting insert having excellent workability and processing accuracy.

  Here, the displacement of the insert in the dimensional direction means that the insert 1 is displaced in a direction that is substantially horizontal with respect to the vertical direction of the main body 2, that is, in the side surface direction. The displacement of the insert in the side surface direction becomes the displacement of the insert in the feed direction of the cutting method in each processing form, and affects the dimensional accuracy of the processed surface of the work material.

  Since the insert 1 is configured so that a strong and stable restraining force acts on the two side surfaces restrained by the holder as described above, the insert 1 can be used as a cutting tool corresponding to a plurality of processing forms such as outer diameter processing and end surface processing. When used, in any processing form, positional deviation in the dimensional direction can be suppressed, and excellent processing accuracy can be shown.

  Moreover, as shown in FIG. 1, since the insert 1 does not have the hole opened in the upper surface 3 provided in the insert corresponding to a lever lock system, the produced | generated chip | tip flows smoothly through the upper surface 3. Therefore, the insert 1 can be discharged smoothly even if it is a very small chip generated during small diameter machining, unlike the conventional insert corresponding to the lever lock method. Even when used in a processing tool, excellent chip discharge performance can be exhibited.

  As shown in FIGS. 1 and 2, the insert 1 of this embodiment is formed so that two side surfaces (4a, 4b) constrained by the holder are adjacent to each other. Accordingly, the first opening 61 is formed so as to open over two adjacent side surfaces (4a, 4b). The insert according to the present invention is not limited to such a configuration, but two side surfaces constrained by the holder are adjacent to each other, and the first opening 61 is formed on both sides of the two adjacent side surfaces (4a, 4b). Since it is formed so as to open, clamping efficiency is increased, which is desirable. That is, it is desirable because the restraining force of the insert 1 acting when the fixing member presses the second opening 62 can be efficiently applied to the two side surfaces (4a, 4b).

  As shown in FIGS. 2A and 2D, the pressing portion 62A located on the second opening 62 side and pressed by the fixing member in the inner wall of the through hole 6 is restrained by the holder in a top view. Of the two side surfaces (4a, 4b) adjacent to the corner cutting edge 5 and a virtual straight line connecting the center O of the inscribed circle of the main body part 2 through L1 and substantially perpendicular to the lower surface of the main body part 2 It forms so that it may be located in the side close | similar to the corner cutting blade 5 with respect to a flat plane. With such a configuration, the pressing portion 62A is disposed at a position closer to the corner cutting edge 5 to which a large cutting force is applied at the time of cutting, that is, a position far from the side surface restrained by the holder.

  The openings 61 and 62 in the present embodiment refer to a portion where the through hole 6 opens to the side surface of the main body portion 2, that is, a portion where the inner wall of the through hole 6 and the side surface of the main body portion 2 are connected. Moreover, the inner wall of the through-hole 6 in this embodiment has the press part 62A pressed by the fixing member at the 2nd opening part 62 side, as shown to Fig.2 (a), (d).

  As shown in FIG. 2A, when the distance from the two side surfaces (4a, 4b) constrained by the holder to the corner cutting edge 5 is equal in the top view as in this embodiment, In any case, the same virtual straight line can be obtained, so the virtual straight line L1 may be obtained by connecting the center O and the midpoint of either side.

  The insert 1 has either one side surface (4a or 4b) of the two side surfaces (4a, 4b) restrained by the holder when the corner cutting edge 5 receives the cutting force. As a starting point, the insert 1 tries to rotate in the lateral direction. That is, as described above, a force that shifts in the dimensional direction acts on the insert 1, but the rotation of the insert 1 caused by the force starts from one of the two side surfaces (4 a, 4 b). It is what.

  Therefore, like the insert 1 of the present embodiment, the pressing portion 62A is formed so as to be located on the side close to the corner cutting edge 5 with respect to a plane that passes through the virtual straight line: L2 and is substantially perpendicular to the lower surface. The insert 1 can be pressed at a position farther from the two side surfaces (4a, 4b) that are the starting points of the rotation of the insert 1. Therefore, it can suppress that the insert 1 shifts | deviates to a dimension direction firmly with smaller force. Therefore, the clamping efficiency is high and the processing accuracy can be further improved.

  The term “substantially perpendicular to the lower surface of the main body 2” here means that the insert 1 is substantially perpendicular to a flat surface that functions as a seating surface when the insert 1 is mounted on the holder.

  Furthermore, when the main body 2 is substantially n-gonal (n ≧ 4: n is a natural number) when viewed from the top, the pressing portion 62A has both ends of the two side surfaces (4a, 4b) when viewed from the top. An imaginary straight line connecting the end portions close to the corner cutting edge 5 among the portions is preferably formed so as to be positioned on the side close to the corner cutting edge 5 with respect to a plane passing through L2 and substantially perpendicular to the lower surface. With such a configuration, the insert 1 is pressed at a position closer to the corner cutting edge 5 and at a position farther from the two side surfaces (4a, 4b) restrained by the holder. Therefore, the effect of improving the above-described clamping efficiency and processing accuracy is enhanced.

  Furthermore, the pressing portion 62A satisfies the positional relationship described above with respect to a plane that passes through the virtual straight lines L1 and L2 and is substantially perpendicular to the lower surface, and is in a curved surface that passes through the virtual inscribed circle of the insert 1 in a top view and is substantially perpendicular to the lower surface. It is desirable to be formed to be positioned. With such a configuration, it is possible to ensure a strong restraining force on the holder and to prevent the fixing member from protruding from the main body 2 when the fixing member is inserted into the through hole 6. Therefore, since the fixing member can maintain a strong restraining force on the holder without interfering with the work material, the clamp efficiency can be further improved.

  In addition, the shape of the opening part 62 close | similar to a corner cutting blade among the opening parts of the both ends of the through-hole 6 should just be a shape with 62 A of press parts pressed by a fixing member. In the present embodiment, as shown in FIG. 2 (d), the pressing portion 62 </ b> A of the inner wall of the through hole 6 has a tapered shape in which the diameter on the outer side is larger than the inner side of the main body portion 2. Is illustrated. As described above, when the pressing portion 62A is tapered, the pressing portion 62A can be stably pressed by forming the pressing portion 62A to have a larger angle with respect to the taper angle of the portion of the fixing member that contacts the pressing portion 62A. .

  Further, the pressing portion 62A may be formed to have a conical shape in addition to the tapered shape. That is, the pressing portion 62 </ b> A may be a convex curved surface that protrudes toward the axis of the through hole 6. With such a configuration, when the insert 1 is initially restrained by a line contact between the fixing member and the pressing portion, the fixing member and the pressing portion are in appropriate surface contact as the fixing member wears. The restraint force of the insert 1 is increased, and the fixing member can be easily removed.

  Furthermore, as shown in FIG. 2D, the axis X of the through hole 6 is provided so as to bisect the angle formed by the two side surfaces (4a, 4b). With such a configuration, since the pressing portion 62A pressed by the fixing member is provided at a position that is symmetric with respect to the axis X of the through-hole 6, both of the two side surfaces (4a, 4b) restrained by the holder A restraining force equal to can be applied. Therefore, the effect of suppressing the displacement of the insert in the dimensional direction is enhanced.

  Furthermore, it is desirable that the axis X of the through hole 6 bisects the corner of one corner portion C where the corner cutting edge 5 is provided. With such a configuration, the insert 1 is symmetric with respect to the two constraining surfaces (4a, 4b) and the corner C where the corner cutting edge 5 that receives a large cutting force during cutting is located. Is also pressed by the fixing member at a symmetrical position. Therefore, the insert 1 is fixed to the holder by a strong and stable restraining force that acts in a balanced manner in the side surface direction of the main body 2. As a result, even in both processing forms in which cutting force is applied in different directions such as outer diameter processing and end surface processing, displacement of the insert 1 in the dimensional direction can be suppressed, and excellent dimensional accuracy can be exhibited.

  Further, as shown in FIG. 2D, the main body 2 desirably has a symmetric shape with a straight line (L2) perpendicular to the axis X of the through hole 6 as a symmetric axis when viewed from above. As a result, the shape of the inner wall of the through-hole 6 is symmetrical with respect to a plane that passes through the bisector L2 and is substantially perpendicular to the lower surface, so that the pressing portion 61A is also provided on the first opening 61 side. It is done. Accordingly, when viewed from above, the corner cutting edge is formed also in the other corner portion C (C2) facing the one corner portion C (C1) provided with the corner cutting edge 5, and the through hole 6 is formed on the upper surface. In view, when provided so as to be located on a diagonal line connecting two corner portions C1 and C2 facing each other, the insert 1 can be constrained to the holder corresponding to the two corner cutting edges 5 by one through hole. . That is, the fixing member can be inserted from the first opening 61 side and fixed to the holder, and the fixing member can be inserted from the second opening 62 side and fixed to the holder. As a result, it is possible to obtain a two-corner insert with a high strength of the main body 2, which is excellent in economic efficiency, and further miniaturization of the insert 1 can be achieved. In addition, since the screw hole formed in the holder corresponding to the through hole 6 can be handled by one, the rigidity of the holder can be increased.

  Further, as shown in FIG. 2B, the through hole 9 is formed so as to be positioned approximately in the middle in the vertical direction of the main body 2. In this way, the through-hole 6 has a shape with the diagonal line connecting the two corners C1 and C2 facing each other as the axis of symmetry, and a symmetrical shape with respect to the middle of the main body 2 in the vertical direction of the main body 2. By forming so as to form a negative type insert with a clearance angle of 0 ° of the main body 2, it can be used as a four-corner insert. That is, the insert can be used on both sides. Therefore, the insert 1 is very excellent in economic efficiency.

  Next, the cutting tool 10 by one Embodiment concerning this invention is demonstrated using FIG. 3 and FIG.

  In FIG. 3, the cutting tool 10 includes a fixing member 7, the above-described insert 1, and a holder 8 to which the insert 1 is fixed by the fixing member 7. The features of the insert 1 constituting the cutting tool 10 are as described above, and a description thereof will be omitted.

  The holder 8 has an insert pocket 11 to which the insert 1 is fixed and a screw hole (not shown) communicating with the through hole 6 of the insert 1.

  The insert pocket 11 has a constraining lower surface 12 that contacts the lower surface of the insert 1, and constraining side surfaces 13 a and 13 b that contact the two side surfaces 4 a and 4 b of the insert 1, respectively. In the present embodiment, a relief portion 14 is formed between the two restraint side surfaces 13a and 13b so that the corner portion where the corner cutting edge 5 ′ not involved in cutting is formed and the holder 8 do not interfere with each other. Yes. Specifically, as shown in FIG. 4A, the relief portion 14 is formed by cutting out the restraint side surface 13b on the restraint side surface 13b side so that the restraint side surface 13b is shorter than the restraint side surface 13a in a top view. ing.

  The screw hole is provided so as to have an axis that is eccentric with respect to the axis of the through hole 6. In this embodiment, the screw hole is formed so as to open to the constraining side surface 13a and the relief portion 14 (not shown). In consideration of the rigidity of the holder and the like, a shape opened on both of the restraining side surfaces 13a and 13b and a shape opened only on the escape portion 14 can be selected as appropriate.

  The fixing member 7 has a screw portion 71 screwed into the screw hole of the holder 8 and a head portion 72 having a larger diameter than the screw portion 71.

  Then, the fixing member 7 is inserted through the other opening (second opening 62) of the two openings of the through hole 6 that opens on the side surface 4 of the insert 1, and the screw portion 71 of the fixing member 7 is inserted into the holder 8. While being screwed into the screw hole, the head 72 of the fixing member 7 presses the pressing portion 62 </ b> A located on the second opening 62 side in the inner wall of the through hole 6. Thereby, the lower surface of the insert 1 is pressed against the restraining lower surface 12 of the holder 8, the side surfaces 4 a and 4 b of the insert 1 are pressed against the restraining side surfaces 13 a and 13 b of the holder 8, and the insert 1 is fixed to the holder 8.

  With such a configuration, by operating the fixing member 7 having the threaded portion 71 from the side surface side of the insert 1 from the side surface side of the insert 1, the fixing member 7 directly presses the insert 1 and the two restraining side surfaces 13 a. , 13b exerts a pressing force on both sides. Therefore, the insert 1 can be firmly and stably fixed to the holder 8, and the insert 1 can be prevented from shifting in the dimensional direction. As a result, high working efficiency and high machining accuracy can be exhibited even when used for small-diameter machining performed using an automatic lathe or the like having a narrow work space on the upper surface side forming the rake face.

  Further, as shown in FIGS. 3 and 4, the holder 8 includes a cutting portion 81 to which the insert 1 is fixed, a gripping portion 82 that is positioned on the rear end side of the cutting portion 81 and is gripped by an external device, Consists of. And as shown in FIG.4 (b), it is desirable to form the upper surface of the cutting part 81 so that it may be located in the substantially same height as the upper surface of the holding part 82. FIG. Thereby, chips flow smoothly on the upper surface of the holder 8. Furthermore, since the upper surface of the gripping portion 82 of the holder 8 is generally formed to have substantially the same height as the corner cutting edge 5 of the insert 1, the upper surface of the cutting portion 81 is gripped as in this embodiment. When the height is substantially the same as the upper surface of the portion 82, a step is generated between the upper surface of the cutting portion 81 and the gripping portion 82, so that it is possible to suppress clogging of chips on the upper surface of the holder. Therefore, chips generated by the corner cutting edge 5 can be smoothly discharged to the outside of the holder 8 without clogging the upper surface of the insert 1 and the upper surface of the holder 8.

  Finally, the cutting method of the work material concerning this invention is demonstrated using FIG. 5 and FIG.

  As an embodiment of the cutting method of the work material according to the present invention, a cutting method for machining the outer diameter of the work material will be described with reference to FIG.

  First, as shown in FIG. 5A, the above-described cutting tool 10 is brought close to the rotating work material 15. Then, as shown in FIG. 5 (b), the corner cutting edge 5 of the cutting tool 10 is brought into contact with the surface of the rotating work material 15, and the cutting tool 10 is moved parallel to the axis of the work material, Cutting material 50 is cut. Then, after machining to the set machining shape, the cutting tool 10 is separated from the work material 15 as shown in FIG.

  By having such a process, since the cutting tool which can suppress that the insert 1 shifts | deviates to a dimension direction at the time of a cutting process is used, a process with a high process precision is possible. In addition, since the replacement of the insert 1 can be handled by work from the side of the insert 1, work efficiency can be improved even in small-diameter machining using an automatic lathe or the like.

  As another embodiment of the cutting method of the work material according to the present invention, a cutting method for machining the end face of the work material will be described with reference to FIG. In addition, description is abbreviate | omitted about the process which overlaps with the outer diameter process mentioned above.

  In the end face machining of the work material, unlike the outer diameter machining of the work material, the corner cutting edge 5 of the cutting tool 10 is brought into contact with the surface of the work material 15 as shown in FIG. The tool 10 is moved along the end surface of the work material to cut the work material 50.

  As described above, the outer diameter machining and the end face machining shown in FIG. 5 are different in the direction (moving) in which the cutting tool 10 is fed to the work material. Therefore, in the cutting tool 10 applied to both the outer diameter processing and the end surface processing in this manner, cutting forces are applied in different directions in the side surface direction. Even in such a machining mode, the cutting tool according to the present invention can suppress the displacement of the cutting insert in the dimensional direction because a strong restraining force acts on the two side surfaces. Therefore, processing with high dimensional accuracy can be realized in both processing modes.

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

1 is an overall perspective view of a cutting insert 1 according to an embodiment of the present invention. (A) Top view of cutting insert 1 of FIG. 1, (b) Side view seen from I direction of (a), (c) Side view seen from II direction of (a), (d) A- of (b) It is A sectional drawing. 1 is an overall perspective view of a cutting tool 10 according to an embodiment of the present invention. 4A is a top view of the cutting tool 10 of FIG. 3, FIG. 4B is a side view of the cutting tool 10 viewed from the I direction, and FIG. 4C is a side view of the cutting tool 10 viewed from the II direction of FIG. It is a schematic explanatory drawing explaining one Example of the cutting method of the cut material concerning this invention. It is a schematic explanatory drawing explaining the other Example of the cutting method of the cut material concerning this invention.

Explanation of symbols

1 Cutting insert (insert)
2 Body 3 Upper surface 4 Side surface (4a, 4b)
5 corner cutting edge 6 through hole 61 first opening 61A pressing part 62 second opening 62A pressing part 10 cutting tool 8 holder 81 cutting part 82 gripping part 7 fixing member 71 screw part 72 head 11 insert pocket 12 constraining lower surface 13 Restraint side (13a, 13b)
14 Relief part

Claims (12)

A cutting insert that includes a main body portion having an upper and lower surface and a plurality of side surfaces, and is used with at least two of the plurality of side surfaces being restrained by a holder by a fixing member,
The main body is positioned at at least one corner when viewed from above, and has a corner cutting edge provided at an intersection between the upper surface and the side, and both ends open to the side so as to penetrate the main body. A through-hole through which the fixing member is inserted,
The through-hole opens over two surfaces of at least one of the two side surfaces constrained by the holder among the plurality of side surfaces and a side surface adjacent to the other side surface of the side surface. A cutting insert having a first opening and a second opening close to the corner cutting edge.   Of the inner wall of the through hole, the pressing portion that is positioned on the second opening side and pressed by the fixing member is a side surface that is close to the corner cutting edge among the two side surfaces that are restrained by the holder in a top view. 2. It is located on the side close to the corner cutting edge with respect to a plane that passes through a virtual straight line connecting the midpoint of the main part and the center of the inscribed circle of the main body portion and is substantially perpendicular to the lower surface. Cutting insert as described. The main body portion has a substantially n-square shape (n ≧ 4: n is a natural number) in a top view,
Of the inner wall of the through hole, the pressing portion that is positioned on the second opening side and is pressed by the fixing member is the corner cutting blade out of both end portions of the two side surfaces that are restrained by the holder in a top view. 3. The cutting insert according to claim 1, wherein the cutting insert is positioned on a side close to the corner cutting edge with respect to a plane substantially perpendicular to the lower surface passing through a virtual straight line connecting ends close to each other.   A pressing portion that is located on the second opening side of the inner wall of the through hole and is pressed by the fixing member is located in a curved surface that passes through a virtual inscribed circle of the main body portion in a top view and is substantially perpendicular to the lower surface. The cutting insert according to claim 2 or 3, characterized in that:   The cutting insert according to any one of claims 1 to 4, wherein an axis of the through hole is provided so as to bisect an angle formed by the two side surfaces.   The cutting insert according to claim 5, wherein the axis of the through hole bisects the corner of the one corner portion where the corner cutting edge is provided.   The cutting insert according to claim 5 or 6, wherein the main body has a symmetrical shape with a straight line perpendicular to the axis of the through-hole as the axis of symmetry when viewed from above. A cutting tool comprising: a fixing member; a cutting insert including a main body portion having upper and lower surfaces and a plurality of side surfaces; and a holder to which the cutting insert is fixed by the fixing member,
The cutting insert is positioned at at least one corner portion when viewed from above, and has a corner cutting edge provided at an intersection between the upper surface and the side surface, and both ends open to the side surface so as to penetrate the main body portion. At least one of the two side surfaces of the plurality of side surfaces constrained by the holder and the side surface and the other side surface side of the two openings located at both ends. A through hole formed over two sides of the side surface adjacent to
The holder includes an insert pocket having a constraining lower surface that contacts the lower surface of the cutting insert and two constraining side surfaces that respectively contact the two side surfaces of the cutting insert, to which the cutting insert is fixed; A screw hole that communicates with the through-hole and has an axis that is eccentric with respect to the axis of the through-hole, and
The fixing member includes a screw portion that is screwed into a screw hole of the holder, and a head portion having a diameter larger than the screw portion,
The fixing member is inserted from the other opening of the two openings of the through hole that opens on the side surface of the cutting insert, and the screw portion of the fixing member is screwed into the screw hole of the holder and fixed. When the head of the member presses the pressing portion located on the other opening side of the inner wall of the through-hole, the lower surface of the cutting insert is moved to the restraining lower surface of the holder, and the two of the cutting inserts are A cutting tool, wherein a side surface is pressed against each of the two constraining side surfaces of the holder, and the cutting insert is fixed to the holder.   The pressing portion is substantially on the lower surface through an imaginary straight line connecting the midpoint of the side surface close to the corner cutting edge of the two side surfaces of the cutting insert in a top view and the center of the inscribed circle of the main body portion. The cutting tool according to claim 8, wherein the cutting tool is located on a side close to the corner cutting edge with respect to a vertical plane. The body portion of the cutting insert has a substantially n-square shape (n ≧ 4: n is a natural number) in a top view,
The pressing portion is formed on the corner cutting edge with respect to a plane substantially perpendicular to the lower surface passing through an imaginary straight line connecting the ends adjacent to the corner cutting edge among the both end portions of the two side surfaces in a top view. The cutting tool according to claim 8, wherein the cutting tool is located on a side close to the cutting tool. The holder includes a cutting portion to which the cutting insert is fixed and a grip portion that is positioned on the rear end side of the cutting portion and is gripped by an external device.
The cutting tool according to any one of claims 8 to 10, wherein the upper surface of the cutting part is positioned at substantially the same height as the upper surface of the gripping part. A step of bringing the cutting tool according to any one of claims 8 to 11 close to a rotating work material;
Contacting the cutting edge of the cutting tool with the surface of the work material, and cutting the work material;
Separating the cutting tool from the work material;
A method for cutting a work material comprising:

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