JP2008238316A - Cutting tool - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem wherein a separation part for dispersing a stress applied from a cutting insert to a tool holder has a limitation for expanding the size of the cross section and the separation part having a desired size cannot be formed. <P>SOLUTION: The cutting tool is equipped with a tool holder having an upper jaw part and a lower jaw part which hold and fix the cutting insert and respectively make the surface contacting with the cutting insert be an insert contact surface, an abutting part which makes a surface abutting on the rear end surface of the cutting insert be an insert abutting surface, and a separation part which is positioned so as to separate from the cutting insert between the insert contact surface and the insert abutting surface of the lower jaw part and makes the surface be the insert separation surface. The separation part has a protruded shape cross section parallel to the lateral direction. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a cutting tool used for cutting metal parts and the like.

  Conventionally, the thing of the structure shown in FIG. 8 is known as a cutting tool used for cutting of metal parts. Here, Fig.8 (a) is a conventional cutting tool, Comprising: It is a fragmentary perspective view which shows the state from which the cutting insert was removed from the tool holder. FIG. 8B is a partial side view showing a state in which the cutting insert is attached to the tool holder, which is a conventional cutting tool.

  As shown in FIG. 8, the conventional cutting tool 102 includes an upper jaw portion 108, a lower jaw portion 110, a tool holder 120 having a separation portion 118 that opens to one end side, and an upper jaw portion 108 and a lower jaw portion 110. And a cutting insert 104 disposed detachably therebetween. A cutting edge 122 is formed at the tip of the cutting insert 104, and cutting can be performed by bringing the cutting edge 122 into contact with a rotating workpiece.

  At this time, since the cutting edge 122 is brought into contact with the work material, the cutting insert 104 is pushed backward. For this reason, the position of the cutting insert 104 is displaced, and it becomes difficult to perform highly accurate cutting. Therefore, a contact portion 116 having an insert contact surface 114 is formed on the tool holder 120, and the insert contact surface 114 is contacted with the rear end surface 112 of the cutting insert 104 to position the cutting insert 104. Thereby, the position shift of the cutting insert 104 is suppressed also at the time of cutting.

Further, during cutting, the cutting insert 104 is subjected to a stress from the upper side to the lower side, which is generated when the cutting material 122 is brought into contact with the rotating work material and the work material is cut. Therefore, a large stress is applied to the separation portion. Therefore, in the conventional cutting tool, the separation portion 118 is formed to be large so that the stress applied to the tool holder 120 via the cutting insert 104 is dispersed.
Special Table 2002-536191 gazette

  In order to disperse the stress applied to the tool holder through the cutting insert, it is desirable to make the insert separation surface as large as possible. This is because if the insert separation surface is small, stress may not be sufficiently dispersed on the insert separation surface, and cracks may occur in a part of the insert separation surface.

  However, as shown in FIG. 8, in the conventional cutting tool, in order to position the cutting insert, it is necessary to form a contact portion. Therefore, there is a limit to the size of the insert separation surface, and an insert separation surface having a desired size cannot be formed. This has been a problem in producing a cutting tool having higher durability.

  In view of the above-mentioned problems, the object of the present invention is to disperse the stress applied to the tool holder over a wide range and suppress the occurrence of cracks in the tool holder by forming a large insert separation surface while positioning the cutting insert. There is to do.

  The cutting tool of the present invention has a cutting insert sandwiched at a tip portion, and has an upper jaw portion and a lower jaw portion each having an insert contact surface that comes into contact with the cutting insert, and an insert contact surface that comes into contact with the rear end surface of the cutting insert. A tool holder comprising: a contact portion; and a separation portion having an insert separation surface positioned so as to be separated from the cutting insert between the insert contact surface and the insert contact surface of the lower jaw portion, The separation portion is characterized in that a cross-sectional shape parallel to the width direction is a convex shape.

  Further, the length of the insert contact surface in the direction perpendicular to the width direction at the center in the width direction may be longer than the length in the direction perpendicular to the width direction at the width direction end of the insert contact surface. preferable. Moreover, it is preferable that the said insert separation surface is a curved surface. Further, it is more preferable that the insert separation surface has a circular arc shape in a cross section parallel to the width direction and perpendicular to the insert separation surface.

  Moreover, it is preferable that the said insert separation | separation surface is a circular arc shape of the cross section perpendicular | vertical to the width direction. Moreover, it is preferable that the curvature of the cross-sectional shape perpendicular | vertical to the width direction in the width direction center part of the said insert separation surface is larger than the curvature of the cross-sectional shape perpendicular | vertical to the width direction in the width direction edge part.

  Moreover, it is preferable that the angle which the said insert separation surface and the insert contact surface of the said lower jaw part cross is an obtuse angle. Moreover, it is preferable that the angle which the said insert separation surface and the said insert contact surface cross is an obtuse angle.

  Further, the tool holder has a second separation portion which is positioned so as to be separated from the cutting insert between the insert contact surface and the insert contact surface of the upper jaw portion and has a surface as a second insert separation surface. It is preferable that the shape of the cross section parallel to the width direction is convex.

  The cutting method of the present invention is a cutting method of cutting a work material using any one of the above-described cutting tools, a proximity step of bringing the cutting tool relatively close to the work material, and the work material A cutting step of cutting the surface of the work material by bringing the cutting blade into contact with the surface of the work material, and a separation step of relatively moving the work material and the cutting tool away from each other. It is characterized by that.

  The cutting tool of the present invention has an upper jaw part and a lower jaw part each having an insert contact surface that is in contact with the cutting insert, and an insert contact surface that comes into contact with the rear end face of the cutting insert. A tool holder provided with a part and a separation part having an insert separation surface positioned so as to be separated from the cutting insert between the insert contact surface and the insert contact surface of the lower jaw part. And the shape of the cross section parallel to the width direction is a convex shape in the separation part.

  Therefore, the insert contact surface can be enlarged at the center in the width direction, while the separation portion can be enlarged at the side end. Thereby, since a big separation part can be formed, without reducing durability of an insert contact surface and a lower jaw part, the stress concerning a tool holder can be distributed in a wide range. As a result, the occurrence of cracks at the separation portion can be suppressed, and the durability of the tool holder can be improved.

  Hereinafter, the cutting tool of this invention is demonstrated in detail using drawing. FIG. 1 is a partial perspective view showing an embodiment of a cutting tool according to the present invention. 2 (a) is a side view of the embodiment shown in FIG. 1, and FIG. 2 (b) is a side view of the embodiment shown in FIG. 2 (a), in which the cutting insert is removed from the cutting tool. The removed state is shown. FIG. 3 is an enlarged perspective view showing the separation portion of the embodiment shown in FIG.

  As shown in FIGS. 1 to 3, the cutting tool 2 of the present embodiment has an upper jaw portion 8 and a lower jaw portion 10 each having an insert contact surface 6 that sandwiches the cutting insert 4 at the tip portion and contacts the cutting insert 4. Positioned so as to be separated from the cutting insert 4 between the contact portion 16 having the insert contact surface 14 that contacts the rear end surface 12 of the cutting insert 4, and the insert contact surface 6 b and the insert contact surface 14 of the lower jaw portion 10. The tool holder 20 is provided with a separating portion 18 having an insert separating surface 17 to be operated. The separating portion 18 has a convex cross-sectional shape parallel to the width direction.

  The cutting insert 4 is sandwiched and fixed at the tip portion, and the upper jaw portion 8 and the lower jaw portion 10 each having a surface that contacts the cutting insert 4 as the insert contact surface 6 and the surface abutting on the rear end surface 12 of the cutting insert 4 are inserted. The abutting portion 16 serving as the contact surface 14, and the separation portion having the surface as the insert separation surface 17 positioned so as to be separated from the cutting insert 4 between the insert contact surface 6 b and the insert contact surface 14 of the lower jaw portion 10. 18, and a tool holder 20 having. And the cross section parallel to the width direction of the separation part 18 is convex shape.

  In the conventional cutting tool 102 shown in FIG. 8, the size of the separation portion 118 in the cross section perpendicular to the width direction is constant. However, if the separation portion 118 is increased in order to increase the stress dispersion effect, there is a problem that the insert contact surface 114 and the contact portion 116 are reduced or the thickness of the lower jaw portion is reduced. .

  On the other hand, in the cutting tool 2 of this embodiment, the cross section parallel to the width direction of the separation part 18 is convex shape. Thereby, since the contact part 16 has a large thickness at the center in the width direction, it can be provided with high durability, and since the separation part 18 is wide at the side end part, the stress is diffused over a wide range. can do. Further, by making the separation portion 18 wide at the side end portion, the stress can be released to the side surface of the tool holder 20 without concentration of stress at the center in the width direction of the separation portion 18.

  As a result, the contact portion 16 can have high durability without reducing the thickness of the lower jaw portion 10, and a high stress dispersion effect can be obtained at the separation portion 18. Generation of cracks can be suppressed.

  Further, the length in the direction perpendicular to the width direction at the center of the width direction of the insert contact surface 14 is preferably longer than the length in the direction perpendicular to the width direction at the end in the width direction of the insert contact surface 14. . It is because durability of the contact part 16 can be improved by forming the insert contact surface 14 in this way.

  Moreover, it is preferable that the insert separation surface 17 is a curved surface. This is because when the insert separation surface 17 has a curved shape, it is possible to suppress the local concentration of stress, and thus the durability of the cutting tool 2 can be improved.

  In addition, it is preferable that the insert separation surface 17 and the tool holder 20 side surface are smoothly connected by, for example, performing an R chamfering process on the intersection between the insert separation surface 17 and the tool holder 20 side surface. By applying an R chamfering process to the intersection, the stress applied to the insert separation surface 17 can be effectively dispersed.

  Further, it is more preferable that the insert separating surface 17 has an arc shape in a cross section parallel to the width direction of the insert separating surface 17 and perpendicular to the insert separating surface 17. In other words, it is preferable that the curvature of the insert separation surface 17 in a cross section perpendicular to the insert separation surface 17 is constant.

  Thus, the shape of the insert separation surface 17 in a cross section parallel to the width direction of the insert separation surface 17 and perpendicular to the insert separation surface 17 is an arc shape or has a constant curvature. It is because it can suppress more reliably that stress concentrates on a certain place locally. As a result, since it becomes possible to disperse stress effectively in the entire width direction of the insert separation surface 17, the durability of the cutting tool 2 can be further improved.

  Furthermore, it is preferable that the curvature of the cross-sectional shape perpendicular to the width direction at the center portion 17a in the width direction of the insert separating surface 17 is larger than the curvature of the cross-sectional shape perpendicular to the width direction at the width direction end portion 17b. Since the curvature of the cross section perpendicular to the width direction of the insert separation surface 17 is as described above, it is possible to more reliably suppress stress from being locally concentrated at a certain place on the insert separation surface 17. Because you can.

  Moreover, it is preferable that the shape of the cross section perpendicular | vertical to the width direction of the insert separation surface 17 is circular arc shape. As described above, when the shape of the cross section perpendicular to the insert separation surface 17 is an arc shape or the curvature is constant, it is possible to more reliably suppress stress concentration at a certain place on the insert separation surface 17. Because it can be done. As a result, the stress can be effectively dispersed throughout the longitudinal direction and the thickness direction of the upper jaw portion 8 and the lower jaw portion 10, so that the durability of the cutting tool 2 can be further improved.

  Moreover, it is preferable that the angle which the insert separation surface 17 and the insert contact surface 6b of the lower jaw part 10 cross | intersect is an obtuse angle. In addition, what is necessary is just to obtain | require the angle which the tangent of the insert separation surface 17 and the insert contact surface 6 cross | intersect in the cross section perpendicular | vertical to the width direction when the insert separation surface 17 is a curved surface.

  When the crossing angle between the insert separation surface 17 and the insert contact surface 6b of the lower jaw portion 10 is an acute angle in a cross section perpendicular to the width direction, stress is applied with a thin thickness between the insert separation surface 17 and the insert contact surface 6b. Part to receive occurs partially. However, when the crossing angle between the insert contact surface 6b and the insert separation surface 17 in the cross section perpendicular to the width direction is an obtuse angle, there is no portion subjected to stress with the above-mentioned thin thickness. This is because the performance can be greatly improved.

  Moreover, it is preferable that the angle which the insert separation surface 17 and the insert contact surface 14 cross is an obtuse angle. In a cross section perpendicular to the width direction, when the angle at which the insert separation surface 17 and the insert contact surface 14 intersect is an acute angle, the portion receives stress with a thin thickness between the insert separation surface 17 and the insert contact surface 14 Partially occurs. However, when the crossing angle between the insert contact surface 14 and the insert separation surface 17 in the cross section perpendicular to the width direction is an obtuse angle, there is no portion subjected to stress with the above thin thickness. This is because the durability can be greatly improved.

  When the insert separation surface 17 is a curved surface, an angle at which the tangent line of the insert separation surface 17 and the insert contact surface 14 intersect in a cross section perpendicular to the width direction may be obtained.

  In addition, the tool holder 20 is positioned so as to be separated from the cutting insert 4 between the insert contact surface 6 a of the upper jaw portion 8 and the insert abutment surface 14, and the surface is a second insert separation surface 23. The separation portion 24 is formed, and the curvature of the cross section perpendicular to the width direction at the center portion in the width direction of the second insert separation surface 24 is larger than the curvature of the cross section perpendicular to the width direction at the end portion in the width direction. preferable.

  By forming the second separation portion 24 at the intersection between the insert contact surface 6a of the upper jaw 8 and the insert contact surface 14, the stress applied to the insert contact surface 14 can be more widely dispersed. .

  Furthermore, it is preferable that the second separating portion 24 has a convex shape in cross section parallel to the width direction. This is because the durability of the insert abutment surface 14 can be further increased because the second separation portion 24 has a convex cross-sectional shape parallel to the width direction.

  This is because the stress applied to the upper jaw 8 can be dispersed over a wide range by the second separation portion 24 in the same manner as the stress applied to the lower jaw 10 of the tool holder 20 is dispersed over a wide range by the separation portion 18. Because it becomes. Moreover, the thickness of the insert contact surface 14 can be increased by forming the second separation portion 24 described above.

  Next, the cutting method of this invention is demonstrated with reference to drawings.

  4 to 6 show process diagrams of the cutting method of the present invention. First, the cutting insert 4 is attached to the tool holder 20. Then, as shown in FIG. 4, the work material 46 is rotated to bring the cutting edge 22 of the cutting tool 2 closer to the work material 46. Note that the cutting edge 22 and the work material 46 may be relatively close to each other. For example, the work material 46 may be close to the cutting tool 2.

  Next, as shown in FIG. 5, the cutting blade 22 is brought into contact with the work material 46 to cut the work material 46. Thereafter, the cutting tool 2 is separated from the work material 46 as shown in FIG. In addition, when continuing a cutting process, the state which rotated the workpiece 46 is maintained, and the process of making the cutting blade 22 of the cutting tool 2 contact the different location of the workpiece 46 is repeated.

  As the above-described cutting method, the outer diameter machining has been described as an example.

  The tool holder 20 of the present embodiment has the cutting insert 4 sandwiched and fixed at the tip, and the upper jaw portion 8 and the lower jaw portion 10 each having a surface in contact with the cutting insert 4 as the insert contact surface 6, and the rear of the cutting insert 4. A contact portion 16 having an insert contact surface 14 as a surface that contacts the end surface 12, and a separation portion 18 spaced from the cutting insert 4 between the insert contact surface 6 b and the insert contact surface 14 of the lower jaw portion 10. Have.

  A holder portion 26 is formed on the rear end side with respect to the upper jaw portion 8, the lower jaw portion 10, the contact portion 16, and the separation portion 18. Further, the tool holder 20 of the present embodiment is formed with a screw hole 30 for inserting the clamp screw 28 from the upper jaw portion 8 to the lower jaw portion 10.

  Moreover, when especially high durability is calculated | required in the tool holder 20 whole, it is preferable that the upper jaw part 8, the lower jaw part 10, and the holder part 26 are integrally formed. This is because, since these are integrally formed, no joining surfaces are formed between the upper jaw portion 8 and the holder portion 26 and between the lower jaw portion 10 and the holder portion 26, so that the rigidity of the cutting tool 2 can be further increased.

  In order to reduce the cost of the cutting tool 2 while obtaining the effects of the present invention, it is also effective that the material of the lower jaw portion 10 is higher than the material of the upper jaw portion 8 and the holder portion 26. When the cutting tool 2 is used, the tip of the cutting insert 4 is pressed from above, so that a stronger stress is more easily applied to the lower jaw part 10 than to the upper jaw part 8 or the holder part 26. In addition, since a material with high rigidity is expensive or a high level of technology is required for processing, a high rigidity material is used for the lower jaw portion 10 that is relatively stressed, and an upper jaw portion having a comparatively low adaptive force. This is because the cutting tool 2 having high durability and low cost can be manufactured by using a material which is lower in rigidity than the lower jaw part 10 and easy to process, for the holder 8 and the holder part 26.

  Further, the tool holder 20 is preferably provided with a slit 32 formed toward the rear end on the rear end side with respect to the upper jaw portion 8 and the lower jaw portion 10. This is because, when such a slit 32 is formed, the upper jaw portion 8 or the lower jaw portion 10 is more easily elastically deformed, so that the cutting insert 4 can be easily attached to and detached from the tool holder 20.

  In particular, as shown in FIGS. 1 and 2, it is preferable that a slit 32 is formed above the contact portion 16 such as the second separation portion. This is because when the slit 32 is formed above the contact portion 16, the thickness of the tool holder 20 below the slit 32 can be increased.

  As shown in FIG. 7, in this embodiment, the cutting insert 4 has a substantially rectangular parallelepiped shape, and includes a rake face 34 on the upper surface of both ends, and a front flank face 36 and a side flank face 38 on the side faces. ing. Further, a front cutting edge 40 is provided at a crossing ridge line portion between the rake face 34 and the front flank face 36, and a horizontal cutting edge 42 is provided at a cross ridge line part between the rake face 34 and the side flank face 38. Here, FIG. 7 is an enlarged perspective view of the cutting insert 4 of the embodiment shown in FIG.

  Further, the cutting insert 4 includes an upper clamp surface 44a on the upper surface and a lower clamp surface 44b on the lower surface, and the upper jaw portion 8 and the lower jaw portion 10 of the tool holder 20 are fitted to the clamp surfaces 44a and 44b, respectively. A clamping surface is preferably provided. This is because by providing such a clamp surface 44, the position of the cutting insert 4 is stabilized, so that the positioning accuracy can be further increased.

  In particular, as shown in FIG. 7, each of the clamp surfaces 44 has a concave shape in the upper clamp surface 44 a and the lower clamp surface 44 b of the cutting insert 4, and the clamp surfaces formed on the upper jaw portion 8 and the lower jaw portion 10, respectively. Is preferably convex. This is because, by forming each clamp surface 44 in this way, the possibility of cracks occurring in the upper jaw 8 or the lower jaw 10 can be further suppressed.

  The cutting insert 4 can be fixed to the tool holder 20 as follows, for example. First, the cutting insert 4 is inserted between the upper jaw portion 8 and the lower jaw portion 10, and the rear end surface 12 of the cutting insert 4 is pressed against the insert contact surface 14. Here, when the above-described clamp surfaces 44 are formed on the cutting insert 4, the upper jaw portion 8, and the lower jaw portion 10, the cutting insert 4 is arranged along the respective clamp surfaces 44 of the upper jaw portion 8 and the lower jaw portion 10. Just insert it.

  Here, the clamp surfaces 44 of the upper jaw portion 8 and the lower jaw portion 10 are formed so that the cross section perpendicular to the longitudinal direction of the tool holder 20 has a V-shaped convex shape, and the upper clamp surface 44 a of the cutting insert 4. And the lower clamp surface 44b are formed so as to have a concavo-convex shape that fits in accordance with each concavo-convex shape. Therefore, the cutting insert 4 is inserted between the upper jaw portion 8 and the lower jaw portion 10 without being displaced from side to side.

  Next, the clamp screw 28 is tightened in such a state. By tightening the clamp screw 28, the upper jaw 8 is elastically deformed and pushed down. As a result, the cutting insert 4 is pressed against the lower jaw 10 and fixed between the upper jaw 8 and the lower jaw 10. Further, when the slit 32 is formed, the upper jaw 8 is more easily elastically deformed by the slit 32, so that the tip of the upper jaw 8 can be pushed down more easily.

  Further, the cutting insert 4 preferably includes a plurality of cutting blades 22. When the cutting insert 4 provided with a plurality of cutting blades 22 is used, another non-wearing cutting blade 22 can be used for the wear of the cutting blade 22 due to long-term use. This is because it is not necessary to prepare an appropriate cutting insert 4 and is economical. For example, in the cutting tool 2 of the present embodiment, when one of the cutting blades 22 is worn, the cutting insert 4 is removed from the cutting tool 2 and the directions of the front end side and the rear end side of the cutting insert 4 are switched. What is necessary is just to attach to the cutting tool 2 again. Thereby, the cutting blade 22 which is not worn can be positioned outside the tool holder 20 and used for cutting.

  Moreover, when the cutting insert 4 is provided with the some cutting blade 22, it is preferable that the 2nd separation part 24 and the cutting blade 22 of the rear end side are spaced apart. Since the second separation portion 24 and the rear end side cutting blade 22 are separated from each other, the second separation portion 24 and the rear end side cutting blade 22 are in contact with each other, and one or the other is damaged. It is because it can suppress doing.

It is a fragmentary perspective view which shows embodiment of the cutting tool concerning this invention. (A) is a side view of the embodiment shown in FIG. Moreover, (b) is a side view of the tool holder of the embodiment shown in FIG. 2 (a), and shows a state where the cutting insert is removed from the cutting tool. It is an expansion perspective view which shows the separation part of embodiment shown in FIG. It is process drawing of the cutting method of this invention. It is process drawing of the cutting method of this invention. It is process drawing of the cutting method of this invention. It is an expansion perspective view of the cutting insert of embodiment shown in FIG. (A) is a perspective view which shows the attachment to the tool holder of the cutting insert of the conventional cutting tool. (B) is a side view of the conventional cutting tool shown to Fig.8 (a).

Explanation of symbols

2, 102 ... Cutting tool 4, 104 ... Cutting insert 6 ... Insert contact surface 8, 108 ... Upper jaw part 10, 110 ... Lower jaw part 12 ... Rear end face 14, 114 ... Insert contact surfaces 16, 116 ... contact portion 17 ... insert separation surface 18, 118 ... separation portion 20, 120 ... tool holder 23 ... second insert separation surface 24 ...・ Second separation part

Claims (10)

An upper jaw part and a lower jaw part having an insert contact surface sandwiching a cutting insert at a tip part and contacting the cutting insert;
A contact portion having an insert contact surface that contacts the rear end surface of the cutting insert;
A cutting tool comprising a tool holder, the tool holder comprising: an insert separation surface positioned so as to be separated from the cutting insert between the insert contact surface and the insert contact surface of the lower jaw portion;
The spacing tool has a convex shape in cross section parallel to the width direction.   The length of the insert contact surface in the direction perpendicular to the width direction at the center in the width direction is longer than the length in the direction perpendicular to the width direction at the width direction end of the insert contact surface. The cutting tool according to claim 1.   The cutting tool according to claim 1 or 2, wherein the insert separation surface is a curved surface.   The cutting tool according to claim 3, wherein the insert separation surface has a circular arc shape in a cross section parallel to the width direction and perpendicular to the insert separation surface.   The cutting tool according to claim 3 or 4, wherein the insert separation surface has an arc shape in a cross section perpendicular to the width direction.   6. The curvature of the cross-sectional shape perpendicular to the width direction at the center in the width direction of the insert separation surface is larger than the curvature of the cross-sectional shape perpendicular to the width direction at the end in the width direction. The cutting tool described in 1.   The cutting tool according to any one of claims 1 to 6, wherein an angle between the insert separation surface and the insert contact surface of the lower jaw portion is an obtuse angle.   The cutting tool according to any one of claims 1 to 7, wherein an angle at which the insert separation surface and the insert contact surface intersect is an obtuse angle. The tool holder is formed with a second separation portion between the insert contact surface and the insert contact surface of the upper jaw portion so as to be separated from the cutting insert and having a surface as a second insert separation surface. And
The cutting tool according to any one of claims 1 to 8, wherein the second separation portion has a convex cross-sectional shape parallel to the width direction. A cutting method for cutting a work material using the cutting tool according to claim 1,
A proximity step of relatively bringing a cutting tool closer to the work material;
A cutting step of rotating the work material, bringing the cutting edge into contact with the surface of the work material, and cutting the surface of the work material;
A cutting method comprising: a separation step of relatively separating the work material and the cutting tool.

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