JPH0753854Y2 - Indexable cutting tool - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention relates to a throwaway type cutting tool suitable for use in finishing cutting such as groove processing and step processing.

[Prior Art] In recent years, when grooving or stepped processing is performed on a work material, a plurality of cutting edge chips are arranged on the outer periphery of the tool body so that the main cutting edge is continuous in the axial direction in the rotation trajectory. In many cases, the installed cutting tools are used. In such a cutting tool, the main cutting edge of each cutting edge is required to be continuous with high accuracy in the rotation trajectory in order to obtain a flat machined surface. In this state, the main cutting edge is subjected to grinding processing (hereinafter, such processing is referred to as set polishing), and the positions of the main cutting edges are aligned for use.

FIG. 8 is a cross-sectional view showing an example of such a conventional cutting tool, and a plurality of blade portions 3 (only one is shown in the figure) having a cutting blade tip 2 brazed and fixed to the outer periphery of the tool body 1. (Shown) is detachably attached by the wedge member 4 and the clamp screw 5. Here, the serration 3a is provided on the lower surface of the blade portion 3.
Are formed. And with such a cutting tool,
When the main cutting edge 2a of the cutting edge tip 2 is worn, all the blade portions 3 are fixed by shifting them by one pitch of the serration 3a toward the outer peripheral side, and the cutting tool is rotated around its axis while the main cutting edge 2a is being rotated. It is possible to perform a grinding process on and to perform set polishing again.

[Problems to be Solved by the Invention] However, in the above cutting tool, the worn main cutting edge 2a is ground again to perform set polishing, so depending on the degree of wear of the main cutting edge, , For example 0.
Large dimensions such as 5 to 1 mm must be ground,
There is a problem that it takes a lot of time to polish the set.

On the other hand, as a cutting tool of this type, for example, Japanese Patent Publication No. 57-55
Many throw-away type cutting tools such as those described in Japanese Patent No. 528 and Japanese Utility Model Laid-Open No. 62-174817 have been proposed. These throw-away cutting tools consist of a plurality of polygonal flat plate-like inserts that are detachably attached by means of wedge members or clamp screws to the insert seat provided on the outer periphery of the tool body. The away tip has a main cutting edge formed on the intersection ridge line between the upper surface and each side surface, and the above upper surface is used as the rake face in the direction of rotation of the tool body, and one of the side faces is directed as the flank face toward the outer peripheral side. The main cutting edge connected to the side surface which is the flank is used for cutting, while the other side surface is brought into contact with the mounting side surface of the tip mounting seat, whereby the tool body is positioned. Then, when the main cutting edge is worn by cutting, the throw-away tip is rotated to direct the other side surface to the outer peripheral side, and the side surfaces other than this side surface are brought into contact with the mounting side surface to remove the throw-away tip. The chip is reattached to the tip seat, replaced with the other main cutting edge formed on the ridge line intersecting with the other side surface and the upper surface, and the cutting is performed again.

However, in such a throw-away type cutting tool, flank wear and chip welding are usually generated on the flanks of the main cutting edge that are used for cutting and are flanks, The side surface is not necessarily smooth and may be uneven. However, when the main cutting edge is replaced, the side surface thus worn comes into contact with the mounting side surface of the tip seat, which causes rattling between the side surface of the throw-away tip and the mounting side surface of the chip seat. There is an unavoidable occurrence of an error in the position accuracy of the cutting edge, which causes a problem that the machining accuracy is deteriorated. In addition, in order to correct such an error in the position accuracy of the main cutting edge, when it is attempted to perform the set polishing as described above after replacing the main cutting edge, the main cutting edges of a plurality of throw-away tips are Another throw-away tip must be ground according to the main cutting edge located on the innermost side, and the grinding allowance also becomes large, which requires a great amount of time for set polishing.

The present invention has been made to solve such a problem, and set polishing can be performed with a small grinding allowance. Therefore, set polishing can be performed in a short time and easily, and the main cutting can be performed. An object of the present invention is to provide a throwaway type cutting tool capable of accurately aligning the positions of main cutting edges when exchanging blades.

[Means for Solving the Problems] A throw-away type cutting tool of the present invention has a tip seat provided on the outer periphery of a tool body rotated around an axis, with an upper surface directed in the rotational direction and a side surface directed toward the outer peripheral side. A polygonal flat plate-shaped positive tip is a throw-away type cutting tool in which a plurality of detachable attachments are attached so that the rotation loci of the main cutting edges formed on the intersecting ridges of the upper surface and the side surface are continuous in the axial direction. On the side of the main cutting edge of the side surface of the positive tip, while forming a flank face with a clearance angle intersecting the upper surface at an acute angle, the ridge line portion of the side surface opposite to the main cutting edge. In the portion leading to, a sloped surface that intersects the flank at an obtuse angle and inclines toward the inside of the chip as it goes to the lower surface side of the positive chip, and a mounting side surface that abuts the sloped surface on the chip seat. Set up on The positive tip was brought into contact with the mounting side surface with the inclined surface as a reference, and was positioned and fixed to the tool body so that a gap was defined between the entire clearance surface and the mounting side surface. It is characterized by that.

[Operation] When the main cutting edge of the positive tip becomes worn, the main cutting edge of each positive tip is replaced and mounted. In this case, since the positive tip is positioned by the inclined surface, the positions of the respective main cutting edges are almost aligned, and therefore the positions of the main cutting edges can be aligned with a slight grinding allowance, and set polishing can be performed in a short time. And it can be done easily. Moreover, the inclined surface of the positive chip is formed so as to intersect with the flank of the side surface of the positive chip at an obtuse angle and incline toward the inner side of the chip as it goes to the lower surface side of the positive chip. While not affected by wear or welding of the flank, a gap is defined between the entire flank and the mounting wall surface of the chip seat when the chip is mounted. Even if a protrusion or the like is formed on the flank due to welding or the like, it is possible to prevent the protrusion from interfering with the mounting of the chip. Then, since the positive tip is positioned and fixed by contacting the mounting side surface of the tip seat with the inclined surface as a reference, according to the throw-away type cutting tool, the position of the main cutting edge when the main cutting edge is replaced Can be aligned accurately.

[Embodiment] An embodiment of the present invention will be described below with reference to FIGS. 1 to 7. FIG. 3 is a side view showing the throwaway cutting tool of the embodiment, in which a plurality of positive tips (positive throwaway tips) 11 are provided on the outer periphery of the tool body 10.
Are arranged so as to draw a spiral along the axis.

On the outer peripheral portion of the tool body 10, a chip pocket 12 having a substantially arcuate transverse cross section is formed. A chip mounting seat 13 is formed behind the chip pocket 12 in the rotation direction. Then, in the chip mounting seat 13, a supporter 14,
The positive chip 11 placed on the upper surface of this supporter 14,
It is detachably attached by wedge members 15 and 16 and clamp screws 17 and 18 (see FIG. 5). Here, as shown in FIG. 6, the supporter 14 has a rectangular plate-like appearance, and a triangular chip seat 19 is formed on the upper surface thereof. The chip seat 19 is composed of a mounting bottom surface 19a and mounting side surfaces 19b and 19c.

The positive chip 11 has a substantially triangular outer shape, and its upper surface
A main cutting edge 20a is formed on the ridge of 20. Further, a sub cutting edge 20b orthogonal to one main cutting edge 20a is formed at a corner of the upper surface 20, and a side surface 21 of the positive tip 11 is formed.
A flank 21a having a clearance angle of about 10 ° is formed in a portion of the predetermined width on the side of the main cutting edge 20a. Also the side 21
The flank 21a is the part that reaches the ridge on the side opposite to the main cutting edge 20a.
On the other hand, an inclined surface 21b is formed which intersects the obtuse angle and inclines toward the inner side (left side in FIG. 2) of the positive tip 11 toward the lower side (lower side in FIG. 2). The inclination angle θ of the inclined surface 21b with respect to the flank 21a is 5
It is said to be ~ 10 °. The inclined surface 21b is configured to come into surface contact with the mounting side surfaces 19b, 19c while being placed on the supporter 14, while the entire flank surface 21 and the mounting side surface 19b,
As shown in FIG.
As it goes toward the upper surface 20 side, a gap that gradually widens according to the inclination angle θ is defined.

Next, a procedure for set polishing in the throwaway type cutting tool thus configured will be described.

First, with all the positive tips 11 ... Attached to the tool body 10, attach the tool body 10 to the cylindrical grinder,
Grinding is performed on each main cutting edge 20a while rotating. In this case, the grinding allowance T may be such that variations in the position of the main cutting edge 20a due to manufacturing errors of the positive tip 11, the supporter 14 and the like are eliminated, and for example, it may be about 0.05 to 0.1 mm in which those manufacturing errors are accumulated. . Next, when the main cutting edge 20a is worn, the main cutting edge 20a of each positive tip 11 is replaced and mounted. In this case, since the positive tip 11 is positioned on the supporter 14 by the inclined surface 21b thereof, set polishing may be performed only by the manufacturing error of the supporter 14 and the like as described above.

In such a throwaway cutting tool, set polishing can be performed with a very small grinding allowance, and therefore set polishing can be performed easily in a short time.

Further, since the inclined surface 21b of the positive tip 11 is formed so as to intersect the flank surface 21a at an obtuse angle and inclines toward the inside of the chip as it goes to the lower surface side, wear of the flank surface 21a and cutting to the flank surface 21a are caused. It is not affected by powder welding. On the other hand, the entire flank 21a of the positive tip 11 and the tip seat 1
Since a gap is defined between the mounting side surfaces 19b and 19c of 9,
Even if there is a protrusion on the flank 21a due to welding or the like, it is possible to avoid a situation in which this interferes with the attachment of the positive tip 11 to the tip seat 19. Moreover, such welding is likely to occur on the cutting edge side of the flank 21a, that is, on the upper surface 20 side of the positive tip 11, whereas in the present embodiment, the gap is gradually widened toward the upper surface 20 side, Interference due to this welding or the like can be prevented more reliably. By contacting the mounting side surfaces 19b and 19c of the chip seat 19 with the inclined surface 21b as a reference, the positive chip 11 is positioned without rattling between the inclined surface 21b and the mounting side surfaces 19b and 19c. Since they can be fixed, the positions of the replaced main cutting edges 20a can be accurately aligned even when the main cutting edges 20a are replaced and the positive tip 11 is welded. Therefore, according to the throw-away type cutting tool having the above configuration, even if the main cutting edge 20a is replaced, its positional accuracy can be maintained and high-precision machining can be performed.

Moreover, even when performing set polishing after replacing the main cutting edge 20a when even higher processing accuracy is required, the position of the replaced main cutting edge 20a is accurately aligned as described above. Since the grinding allowance can be suppressed to a small value, it becomes possible to perform set polishing easily in a shorter time.

Although the positive chip 11 has a triangular shape in the above embodiment, it may have various shapes such as a rhombus.

[Effects of the Invention] As described above, in the throwaway cutting tool of the present invention, the tip seat is provided on the outer periphery of the tool body that is rotated around the axis, the upper surface is directed in the rotation direction, and the side surface is the outer peripheral side. A polygonal flat plate-shaped positive tip for
In a throw-away type cutting tool, which is detachably mounted so that the rotation loci of the main cutting edges formed on the intersecting ridge line between the upper surface and the side surface are continuous in the axial direction, the main cutting among the side surfaces of the positive tip. On the blade side part, while forming a flank with a clearance angle by intersecting the upper surface at an acute angle,
In the portion reaching the ridge line portion on the side opposite to the main cutting edge of this side surface, an inclined surface that is inclined toward the inside of the tip as it goes to the lower surface side of the positive tip intersecting the clearance surface at an obtuse angle, is formed. Further, the tip seat is provided with a mounting side surface that abuts on the inclined surface, and the positive tip is abutted on the mounting side surface with the inclined surface as a reference, while between the entire clearance surface and the mounting side surface. So that the gap is defined,
Since it is positioned and fixed to the tool body, the positive tip is positioned by the inclined surface that is not affected by flank wear and welding, and even if a protrusion or the like occurs on the flank due to welding, etc. The gap defined between the tip seat and the mounting side prevents the protrusion from interfering with each other, so it is possible to suppress the mounting error when replacing the main cutting edge and maintain the position accuracy of the main cutting edge. This makes it possible to obtain the effect that the processing accuracy can be improved, and the set polishing can be easily performed in an extremely short time.

[Brief description of drawings]

1 to 7 are views showing an embodiment of the present invention, in which FIG. 1 is a cross-sectional view showing a throwaway type cutting tool, and FIG. 2 is a part of an arrow II in FIG. Enlarged view, third
FIG. 4 is a side view showing the entire throwaway cutting tool, FIG. 4 is a view in the direction IV of FIG. 3, FIG. 5 is a view in the direction V of FIG. 1, and FIG. VI-VI line arrow view, FIG. 7 is a VII direction arrow view of FIG. 6, and FIG. 8 is a cross-sectional view showing an example of a conventional cutting tool. 10 …… Tool body, 11 …… Positive tip, 20 …… Top surface, 20a
…… Main cutting edge, 21 …… Side surface, 21a …… Relief surface, 21b …… Sloping surface.

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Osamu Tsujimura 1-27-20 Nishishinagawa, Shinagawa-ku, Tokyo Mitsubishi Metals Co., Ltd. Tokyo Works (72) Inventor Soichi Kitada 1-2-7 Nishishinagawa, Shinagawa-ku, Tokyo No. 20 Inside Tokyo Works of Mitsubishi Metals Co., Ltd. (56) References: 62-174817 (JP, U): 57-105102 (JP, U): 49-12710 (JP, Y1)

Claims (1)

[Scope of utility model registration request] 1. A polygonal flat plate-shaped positive tip having an upper surface directed in the rotational direction and a side surface directed toward the outer peripheral side is provided on a chip seat provided on the outer periphery of a tool body rotated around an axis, In a throw-away type cutting tool that is removably attached so that the rotation locus of the main cutting edge formed on the crossing ridge part of is continuous in the axial direction, in the side of the main cutting edge of the side surface of the positive tip. Is
On the upper surface, a flank is formed which intersects the flank at an acute angle to form a flank.On the other hand, at a portion of the side surface that extends to the ridge line portion on the side opposite to the main cutting edge, the flank crosses the flank at an obtuse angle. An inclined surface that inclines toward the inner side of the positive tip toward the lower surface side of the positive tip, and the tip seat is provided with a mounting side surface that abuts the inclined surface. While being brought into contact with the mounting side surface on the basis of the inclined surface, it is positioned and fixed to the tool body so that a gap is defined between the entire flank surface and the mounting side surface. A throwaway type cutting tool.