JP2007168044A - Holder for end surface grooving work and cutting tool using it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cutting holder for end surface grooving work high in holder rigidity and long in tool life. <P>SOLUTION: This cutting holder is constituted of a rod type shank part 2 and a head part 3 arranged on the one end side of the shank part 2 and integrally formed with it, the head part 3 is furnished with an upper jaw part 7 and a lower jaw part 8 to hold and fix a cutting insert 4 in the vertical direction, an upper clamping surface 9 to pressurize the cutting insert 4 from above the cutting insert 4 is arranged on the upper jaw part 7, a lower clamping surface 10 to be a placing surface of the cutting insert 4 is arranged on the lower jaw part 8, at least the lower jaw part 8 out of the upper jaw part 7 and the lower jaw part 8 is furnished with a protruded type curved side surface 13 and a recessed type curved side surface 14 right and left side surfaces of which are curved as seen from head ends, and the lower jaw part 8 is constituted so that a flat side surface 15 is arranged between the protruded type curved side surface 13 and the lower clamping surface 10. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a holder used for end face grooving in cutting of a metal material or the like, and a cutting tool using the holder.

  Generally, in a cutting process of a metal material or the like, as a holder used for grooving and a cutting tool using the same, a structure in which a cutting blade of a cutting insert protrudes from the tip of the holder is known. Specifically, as a configuration of a general grooving cutting tool, a slit formed from the front end surface of the holder toward the rear end side, and an upper jaw portion for pressing the cutting insert above the slit And a lower jaw portion that is located below the slit and formed at the tip of the holder, and a fixing bolt for fastening the upper jaw portion. And the structure which mounts the cutting insert which has a cutting blade in the insert attachment part formed in the lower jaw part, presses a part of upper jaw part to the upper surface of the cutting insert, and also clamps and fixes the cutting insert with a fixing bolt It is.

Moreover, about the cutting tool for processing a circular groove | channel on the end surface of a work material as disclosed by patent document 1, the upper jaw part and lower jaw part which are clampingly fixing this cutting insert from the upper and lower sides with a cutting insert Both of them must be inserted into a circular groove, and therefore, the side surfaces of the upper jaw and the lower jaw are curved when viewed from the front end of the holder.
JP-A-3-142102

  However, in the conventional end surface grooving holder as disclosed in Patent Document 1, the side surface of the lower jaw portion that receives the cutting load during grooving is curved in an arch shape as viewed from the front end of the holder as described above. Therefore, the thickness of the lower jaw portion in the height direction could not be sufficiently secured, and the holder rigidity was insufficient. In particular, in holders for processing small-diameter circular grooves, the thickness of the lower jaw is further reduced and the rigidity of the holder is reduced, so stress concentrates on the base end of the insert mounting part and cracks occur. There was a problem that the holder had to be frequently replaced because the lower jaw part was damaged or it was damaged early.

  The present invention has been made to solve the above-described problems of the prior art, and provides a cutting holder for grooving that has a high holder rigidity and a long tool life in a cutting holder used for end face grooving. The purpose is to do.

  In order to solve the above-described problem, an end surface grooving cutting holder according to the present invention includes a substantially rod-shaped shank portion and a head portion which is disposed on one end side of the shank portion and is integrally formed. The head portion includes an upper jaw portion and a lower jaw portion for sandwiching and fixing the cutting insert in the vertical direction, and an upper clamp surface for pressing the cutting insert from above the cutting insert on the upper jaw portion. And a lower clamp surface serving as a mounting surface for the cutting insert is disposed on the lower jaw part, and at least the lower jaw part of the upper jaw part and the lower jaw part is in front view. The left and right side surfaces are curved with convex curved side surfaces and concave curved side surfaces, and the lower jaw portion has a flat side surface between the convex curved side surface and the lower clamp surface.

  According to this configuration, by providing a flat side surface between the convex curved side surface and the lower clamp surface, the rigidity of the lower jaw portion is increased, and the stress applied during cutting load during grooving and clamping of the cutting insert is increased. As a result, problems such as breakage of the lower jaw and occurrence of cracks can be suppressed.

  In addition, the fact that the lower clamp surface and the flat side surface are in a vertical positional relationship can maximize the rigidity of the lower jaw within a range in which the tool does not interfere with the circular groove wall surface processed with the work material. Is desirable.

  Furthermore, the flat side surface is arranged on the tangent line of the convex curved side surface in the front end view of the lower jaw portion, and the rigidity of the lower jaw portion is suppressed from being reduced, and the cutting load and the clamping stress of the cutting insert are concentrated. Thus, it is desirable in that it can be prevented from becoming a starting point of cracks and the like.

  Further, the relationship between the width T in the height direction of the flat side surface and the radius of curvature R of the convex curved side surface satisfies 0.02 ≦ (T / R) ≦ 0.1. This is desirable because it can be optimized.

  Furthermore, the lower clamp surface is inclined with respect to the axial direction of the shank portion so that the thickness in the height direction of the lower jaw portion gradually increases from the front end side of the head portion toward the shank portion side. This is desirable in that the rigidity of the lower jaw portion is increased, and in particular, the occurrence of cracks in the proximal end portion of the insert mounting portion and the breakage of the lower jaw portion can be suppressed.

  Further, according to the cutting tool in which the cutting insert is mounted on the lower clamp surface of the end surface grooving holder so that the cutting edge protrudes forward, the holder structure in which the lower clamp surface is inclined is used. The holder rigidity in the vicinity of the insert mounting part is increased, it can sufficiently withstand the cutting load during grooving, and the occurrence of cracks in the base end part of the insert mounting part and damage to the lower jaw is suppressed, resulting in a tool life A long cutting tool can be obtained.

  The end face grooving holder of the present invention has a flat side surface between the convex curved side surface and the lower clamp surface, so that the rigidity of the lower jaw portion is increased, and the cutting load and cutting insert during grooving are increased. It is possible to sufficiently withstand the stress applied at the time of clamping, and as a result, problems such as breakage of the lower jaw and occurrence of cracks can be suppressed.

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

  1 and 2 show an embodiment of an end face grooving holder (hereinafter abbreviated as a holder) of the present invention, and FIG. 1 is a front view of the holder according to an embodiment of the present invention. 2 is a side view of the holder of FIG. FIG. 3 is a side view of a cutting tool in which a cutting insert is mounted on the end face grooving cutting holder of FIG.

  1 and 2, a holder 1 according to an embodiment of the present invention includes a substantially rod-shaped shank portion 2 to be attached and fixed to a tool post (not shown) of a machine tool, and the shank portion 2. The head portion 3 is formed integrally with one end of the head portion 3. The head portion 3 is opened at the front end side of the head portion 3 in order to attach a cutting insert 4 (hereinafter, abbreviated as an insert) having a cutting edge for processing a work material (not shown). 1, and is divided by a slit 6 formed from the front end side of the head portion 3 toward the shank side, and as shown in FIG. An upper jaw portion 7 and a lower jaw portion 8 which are curved in a substantially circular shape when viewed from the front end so as to be inserted into the groove are provided. Further, in the insert mounting portion 5, an upper clamp surface 9 for pressing the upper surface of the insert 4 is formed on the upper jaw portion 7, and a lower clamp surface 10 serving as a mounting surface for the insert 4 is The lower jaw 8 is formed in the lower jaw 8, the upper clamp surface 9 and the lower clamp surface 10 sandwich the insert 4 in the vertical direction, and a fixing bolt 11 is inserted into a through hole formed in the upper jaw 7. By screwing the fixing bolt 11 into the screw hole formed in 8, the upper jaw 7 is gradually elastically deformed toward the lower jaw 8 and finally the insert 4 is clamped and fixed (see FIG. 3). . Here, as shown in FIG. 1, the lower jaw portion 8 includes a convex curved side surface 13 and a concave curved side surface 14 whose left and right side surfaces are curved as viewed from the front end of the holder. A flat side surface 15 is provided between the curved side surface 13 and the lower clamp surface 10. With such a configuration, the lower jaw surface 8 is more rigid than the configuration in which the lower clamp surface 10 is adjacent to the convex curved side surface 13, and the stress applied during the grooving process and the cutting load during clamping is reduced. As a result, it is possible to suppress problems such as breakage of the lower jaw part and occurrence of cracks at the base end part of the insert mounting part. In particular, since the lower clamp surface 10 and the flat side surface 15 are in a vertical relationship, the rigidity of the lower jaw can be further increased as long as the tool does not interfere with the circular groove wall surface processed with the work material.

  In addition, the flat side surface 15 is arranged on the tangent line of the convex curved side surface 13 in the front end view of the lower jaw, that is, the boundary portion between the flat side surface 15 and the convex curved side surface 13 is smoothly connected. Therefore, the lowering of the rigidity of the lower jaw can be suppressed. This is because if there is an edge that forms a corner at the boundary, stress concentration due to the cutting load or the clamping of the cutting insert is likely to occur at the portion, and as a result, a crack or the like is likely to start.

  Further, in order to maintain the rigidity of the lower jaw in a more optimal state, the width T in the height direction of the flat side surface 15 and the radius of curvature R of the convex curved side surface 13 are set to 0.02 ≦ (T / R) ≦ 0.1 may be adjusted so as to satisfy the relationship. If T / R is less than 0.02 or more than 0.1, the rigidity of the lower jaw tends to be insufficient, and interference with the inner wall surface of the circular groove processed into the work material There is also a problem that it becomes easier.

  FIG. 4 shows a side view of a holder according to another embodiment of the present invention. Here, the lower clamp surface 10 is inclined with respect to the axial direction of the shank portion so that the thickness h in the height direction of the lower jaw portion 8 gradually increases from the holder tip side toward the shank side. With such a configuration, the thickness of the lower jaw portion 8 in the height direction increases from the front end side toward the shank side, so that the holder rigidity, particularly the rigidity of the lower jaw portion 8 is increased, and the lower jaw portion during grooving 8 can sufficiently withstand the cutting load received, and problems such as the occurrence of cracks in the base end portion 5a of the insert mounting portion 5 and breakage of the lower jaw portion 8 are suppressed.

Further, in the present embodiment, as shown in FIG. 4, the slit 6 is also inclined at the inclination angle α ₃ as the lower clamp surface 10 is inclined. By tilting the slit 6 in this way, the upper jaw 7 is gradually elastically deformed by the fixing bolt 11 to clamp and fix the insert 4, so that the slit 6 serves as a reference surface of the holder 1 and the upper surface of the shank portion 2. The upper jaw 7 can be elastically deformed more easily than the case where it is formed parallel to 2a, that is, the upper jaw 7 can be easily elastically deformed with a relatively small force.

Further, in the present embodiment, the tilt angle α ₂ of the upper clamp surface 9 is smaller than the tilt angle α ₁ of the lower clamp surface 10 in the clamp open state. Thereby, when the upper jaw part 7 is elastically deformed and tries to press the insert 4, the upper clamp surface 9 and the upper surface of the insert 4 are effectively brought into surface contact with each other, so that the insert 4 is restrained more stably. be able to.

  Further, the fixing bolt 11 is arranged so that the head of the fixing bolt 11 is inclined at the inclination angle β toward the tip of the holder with respect to the direction perpendicular to the upper surface 2a of the shank portion 2. Accordingly, the elastic deformation of the upper jaw portion 7 can be more effectively caused as compared with the case where the fixing bolt 11 is tightened in the direction perpendicular to the upper surface 2 a of the shank portion 2.

Furthermore, by setting the inclination angle β of the fixing bolt 11 to be larger than the inclination angle α ₁ of the lower clamp surface 10, elastic deformation of the upper jaw portion 7 is caused more effectively, and the insert 4 is restrained more stably. be able to.

  Further, as shown in FIG. 3, according to the cutting tool in which the insert 4 is mounted on the insert mounting portion 5 of the holder 1 according to the embodiment of the present invention so that the cutting edge protrudes forward, as described above. Since the flat side surface 15 is disposed between the convex curved side surface 13 and the lower clamp surface 10 of the lower jaw portion 8, compared to the configuration in which the lower clamp surface 10 is adjacent to the convex curved side surface 13, The rigidity of the lower jaw 8 is increased and it can sufficiently withstand the cutting load during grooving and the stress applied when clamping the cutting insert, resulting in damage to the lower jaw and cracks at the proximal end of the insert mounting part. Problems such as occurrence can be suppressed, and a cutting tool with a long tool life can be obtained.

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

It is a front end view of the end face grooving cutting holder according to the embodiment of the present invention. It is a side view of the cutting holder for end face grooving of FIG. It is a side view of the cutting tool which mounted | wore the cutting insert with the end surface grooving cutting holder of FIG. It is a side view of the cutting holder for end face grooving processing by other embodiment of this invention.

Explanation of symbols

1 End face grooving holder (holder)
2 Shank part 2a Top surface of shank part 3 Head part 4 Cutting insert (insert)
5 Insert mounting portion 5a Base end portion 6 of insert mounting portion Slit 7 Upper jaw portion 8 Lower jaw portion 9 Upper clamping surface 10 Lower clamping surface 11 Fixing bolt 12 Cutting tool 13 Convex curved side surface 14 Concave curved side surface 15 Flat side surface T Flat side surface Width R in the height direction Curvature radius α of the convex curved side surface ₁ Inclination angle α of the lower clamp surface ₂ Inclination angle α of the upper clamp surface ₃ Inclination angle of the slit β Inclination angle of the fixing bolt h Thickness in the height direction of the lower jaw

Claims (6)

An end face grooving holder for performing circular grooving on the end face of the work material,
A substantially rod-shaped shank portion, and a head portion that is disposed on and integrally formed with one end of the shank portion,
The head portion includes an upper jaw portion and a lower jaw portion for sandwiching and fixing the cutting insert in the vertical direction,
The upper jaw part is provided with an upper clamp surface for pressing the cutting insert from above the cutting insert, and the lower jaw part is provided with a lower clamp surface serving as a mounting surface for the cutting insert. Has been established,
Of the upper jaw and the lower jaw, at least the lower jaw includes a convex curved side surface and a concave curved side surface with curved left and right side surfaces when viewed from the distal end.
The lower grooving holder is characterized in that the lower jaw portion has a flat side surface between the convex curved side surface and the lower clamp surface. The end face grooving holder according to claim 1, wherein the lower clamp surface and the flat side surface are in a vertical positional relationship. 3. The end face grooving holder according to claim 1, wherein the flat side surface is disposed on a tangent line of the convex curved side surface in a front end view of the lower jaw part. 4. 4. The relationship between the height T of the flat side surface and the radius of curvature R of the convex curved side surface satisfies 0.02 ≦ (T / R) ≦ 0.1. The end face grooving holder according to any one of the above. The lower clamp surface is inclined with respect to the axial direction of the shank part so that the thickness in the height direction of the lower jaw part gradually increases from the front end side of the head part toward the shank part side. The holder for end face grooving according to any one of claims 1 to 4. A cutting tool in which a cutting insert is mounted on the lower clamp surface of the end face grooving holder according to any one of claims 1 to 5 so that the cutting edge protrudes forward.

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