JP2008290214A - Tip for boring and boring tool using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a tip for boring which is excellent in machining accuracy such as a diameter of a boring hole and a surface roughness of an inner wall and has a long life of a cutting blade, especially in boring a small diameter, and a boring tool using the tip. <P>SOLUTION: On the tip for boring, a rake face 21 is formed at least one side of a polygonal face opposite to a tip body 20 which has a polygonal plate shape and a cutting blade 30 provided with a side cutting blade 33 and a front cutting blade 34 is formed at a corner of the polygonal face being the rake face 21. When looking at the cutting blade 30 from an intersecting direction, a top 35 of the cutting blade is located at a lower part of a front edge 21 of the corner, and the side cutting blade 33 and the front cutting blade 34 are formed inside thereof including a ridge part of the polygonal face. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a boring tool suitable for boring with a small diameter and a boring tool using the same.

  2. Description of the Related Art Conventionally, an inner diameter machining throw-away tip used for boring has a clamping portion and at least one protruding portion that integrally protrudes from the clamping portion. There is one provided with a cutting edge (for example, see Patent Document 1). In this conventional throw-away tip for inner diameter processing, the protrusion provided with the cutting edge can be formed to a thickness that fits within the desired small-diameter processing hole diameter without considering the clamp. Inner diameter machining such as boring with a diameter of less than 2 to 5 mm can be performed. Since it is not necessary to consider that the clamp part enters the processing hole, the clamp part can be formed in a size necessary for the clamp.

In addition, in the throw-away type cutting tool for inner diameter machining, a polygonal chip body and a plurality of protrusions that protrude integrally from the peripheral surface of the chip body are provided, and a cutting edge is provided at the tip of the protrusion The throw-away tip is clamped by a plurality of peripheral surfaces of the chip body, the protrusion is positioned on the inner side of the extension line of at least one peripheral surface to be clamped, and the clamping surface of the chip body is surface roughness (Ry ) Has a polished surface of 0.8 μm or less (see, for example, Patent Document 2). In this throw-away type cutting tool, it is possible to increase the clamping force of the throw-away tip and suppress chatter vibration during cutting, so that stable and highly accurate inner diameter machining is possible.
Japanese Patent Laid-Open No. 11-320217 (see FIGS. 1 and 4) JP 2003-340611 A (see FIG. 1)

  The throw-away tip for inner diameter processing and the throw-away type cutting tool described in Patent Document 1 and Patent Document 2 are excellent in accuracy and strength for clamping the throw-away tip to the cutting tool, but protrude into the pilot hole and participate in cutting. The part has a smaller diameter and longer length than the part to be clamped, resulting in a significant decrease in rigidity, resulting in inferior processing accuracy such as the hole diameter after processing and the surface roughness of the inner wall surface of the hole. there were.

  The present invention has been made in view of the above-described problems, and the object thereof is excellent in processing accuracy such as the hole diameter of the processing hole and the surface roughness of the inner wall surface, particularly in the boring of a small diameter, and the life of the cutting blade. Is to provide a long boring insert and a boring tool using the same.

In order to solve the above problems, the present invention has the following configuration.
According to the first aspect of the present invention, a rake face is formed on at least one of the opposing polygon faces of the chip body having a polygonal plate shape. A cutting edge portion having a front cutting edge is formed, and when viewed from a direction perpendicular to the polygonal surface, the top portion of the cutting edge portion is lower than the tip of the corner portion, and the horizontal cutting edge and the front edge A cutting edge is formed on the inside including a side ridge portion of the polygonal surface.
The boring tool insert according to claim 1 is such that the top of the cutting edge portion is positioned lower than the tip of the corner portion of the polygonal surface serving as the rake face of the chip body when viewed from the direction orthogonal to the polygonal surface serving as the rake face. In addition, since the side cutting edge and the front cutting edge are formed on the inside including the side ridges of the polygonal surface, portions other than the side cutting edge and the front cutting edge involved in cutting are covered. Since the cutting edge portion can be formed with a thickness that fits into the pilot hole with a small diameter so as not to interfere with the work material, boring with a small diameter is possible. Moreover, the length at which the cutting edge protrudes from the chip body can be suppressed to prevent the strength from being lowered, the machining accuracy of the hole after machining is excellent, and the life of the cutting edge is lengthened.

The invention according to claim 2 is the boring tool according to claim 1, wherein a front cutting edge angle of the cutting edge portion is set in a range of 15 ° to 45 °.
According to the insert for boring according to claim 2, since it is avoided that the front cutting edge of the cutting edge portion contacts the end face of the machining hole, an increase in cutting resistance is prevented, and machining accuracy in boring is improved. Enhanced.

The invention according to claim 3 is the boring tool according to claim 1 or 2, wherein a side cutting edge angle of the cutting edge portion is set in a range of 15 ° to 45 °. .
According to the insert for boring according to claim 3, since it is avoided that the side cutting edge of the cutting edge part contacts the inner wall surface of the machining hole, an increase in cutting resistance is prevented, and machining accuracy in boring machining Is increased.

According to a fourth aspect of the present invention, when viewed from a direction orthogonal to the polygonal surface, a concave portion is formed by cutting out at least one side ridge portion of the polygonal surface, and a horizontal cutting edge and a front cutting edge are formed on the ridgeline of the concave portion. The chip for boring work according to any one of claims 1 to 3, wherein at least one of the blades is formed.
According to the chip for boring according to the fourth aspect, the cutting edge portion can be formed to a thickness that can be inserted into the pilot hole having a small diameter.

According to a fifth aspect of the present invention, when viewed from a direction orthogonal to the polygonal surface, a chamfered portion is formed by cutting out at least one side ridge portion of the polygonal surface, and the chamfered portion crosses the ridgeline of the chamfered portion. 5. The boring chip according to claim 1, wherein at least one of the blade and the front cutting blade is formed.
According to the chip for boring according to the fifth aspect, the cutting edge portion can be formed to a thickness that can be inserted into the pilot hole having a small diameter. Moreover, since the angle formed by the top portion is increased, the strength of the cutting edge is increased, the accuracy of the processed hole is improved, and the life of the cutting edge is extended.

The invention according to claim 6 is a rake face in a boring tool in which the boring tool insert according to any one of claims 1 to 5 is mounted on a chip seat provided at a predetermined position of the tool body. A cutting edge portion having a horizontal cutting edge and a front cutting edge is formed at the corner portion of the polygonal surface, and when viewed from a direction orthogonal to the polygonal surface, the top of the cutting edge portion is the tip of the corner portion. The boring tool is characterized in that it is at a lower position, and the side cutting edge and the front cutting edge are formed inside including a side ridge portion of the polygonal surface.
According to the boring tool according to the sixth aspect, the top of the cutting blade portion located on the tip side of the boring tool is located lower than the tip of the corner portion of the chip body of the boring tool, and the cutting blade portion Since the side cutting edge and the front cutting edge are formed on the inside including the side ridges of the polygonal surface that is the rake face, the part other than the side cutting edge and the front cutting edge involved in cutting is the work material. Since the cutting edge portion can be formed to a thickness that fits into the pilot hole with a small diameter so as not to interfere with the drilling, a boring process with a small diameter is possible. Furthermore, the length by which the cutting edge portion protrudes from the chip body is suppressed, and the strength is prevented from being lowered. As a result, the accuracy of the processed hole is improved and the life of the cutting edge is extended.

The invention according to claim 7 is characterized in that the boring tool is detachably mounted on the tool body by contacting the lower surface and at least one side surface of the chip body with the chip seat. The boring tool according to Item 6.
According to the boring tool according to the seventh aspect, since the boring chip has a highly rigid chip body restrained and fixed to the chip seat of the tool body, the clamping strength of the boring chip to the tool body is fixed. And the clamping accuracy is increased. Therefore, chatter and chipping of the cutting edge due to the movement of the boring tool are prevented, and a long cutting edge life and high machining accuracy are realized.

  According to the present invention, it is possible to perform boring with a small diameter, prevent a reduction in the strength of the cutting edge, and improve the accuracy of the machining hole and prolong the life of the cutting edge.

  Embodiments to which the present invention is applied will be described with reference to the drawings. FIG. 1 is a front view of a main part of a boring tool according to the present embodiment. FIG. 2 is a side view of the boring tool shown in FIG. 3A is a plan view of the boring tool shown in FIG. 1, and FIG. 3B is an enlarged plan view of the cutting edge portion. FIG. 4 is an enlarged plan view for explaining a cutting situation by the boring tool shown in FIG.

  As shown in FIGS. 1 and 3, this boring tool is formed with a chip pocket formed by cutting out the upper half of the tool body 10 at the tip of the tool body 10 having a round bar shape, and the bottom surface of the chip pocket. A tip seat 12 is cut out at the tip of the tip, and a chip for boring is attached to the tip seat 12.

  As shown in FIG. 3, the chip for boring has a chip body 30 having a rhombus plate shape, and a mounting hole is formed in the center of the rhombus surface so as to penetrate in the thickness direction of the chip body. A fastening screw such as a bolt inserted through the mounting hole is detachably fixed to the tip seat 12 of the tool body. Specifically, the rhombus surface that is the lower surface of the chip body 20 contacts the bottom surface of the chip seat 12, and the two side surfaces of the chip body 20 located on the tool body 10 side respectively contact the corresponding wall surface of the chip seat 12. Is fixed.

  As shown in FIG. 4, a cutting edge portion provided with a side cutting edge 33 and a front cutting edge 34 at a corner portion forming an acute angle of the rhombus face when viewed from a direction orthogonal to the rhomboid face that is the upper surface of the chip body 20. 30 is formed. And the top part 35 of a cutting blade part is lower than the front-end | tip 21 of a corner part, and the horizontal cutting edge 33 and the front cutting edge 34 are formed in the inner side including the side ridge part of the said rhombus. Specifically, as shown in FIGS. 3 and 4, the side cutting edge 33 of the cutting edge is formed on the ridge line of the recess 36 notched on one side extending from the corner forming the acute angle of the rhomboid surface, and the front cutting Since the blade 34 is formed on the ridge line of the chamfered portion 37 that cuts out the other side extending from the corner portion, the horizontal cutting blade 33 and the front cutting blade 34 include the side ridge portion of the rhombus surface. It is formed on the inside. Furthermore, the top part 35 of the cutting edge part where the horizontal cutting edge 33 and the front cutting edge 34 intersect is formed lower than the tip 21 of the corner part. The flank 32 extending downward from the horizontal cutting edge 33 and the front cutting edge 34 is a positive flank inclined so as to retract inward as the distance from the cutting edges 33, 34 increases. As shown in FIGS. 1 and 2, the bottom of the cutting edge 30 where the flank surfaces 32 intersect with each other is formed to be inclined so as to gradually approach the rake face 31 as it approaches the top 35 of the cutting edge. Yes.

  As shown in FIG. 4, the boring tool and the boring tool equipped with the boring tool are inserted into the prepared hole opened in the work material and rotated around the axis of the prepared hole. Boring is performed on the prepared hole by being sent in the axial direction and the direction orthogonal to the direction of the work material to be made. At this time, when viewed from the direction orthogonal to the rhombus surface of the chip body 20, the top portion 35 of the cutting blade portion is located lower than the tip 21 of the corner portion of the rhombus surface, and the side cutting blade 33 and the front cutting blade 34 are the rhombus. Since it is formed inside including the side ridge part of the surface, the cutting edge part 30 can be formed to a thickness that fits into the small-diameter pilot hole and interferes with the work material other than the part involved in cutting Therefore, it is possible to perform boring with a small diameter. In addition, since the length protruding from the tip body 20 is suppressed in the cutting edge portion 30 that is not supported by the bottom surface and the wall surface of the tip seat 12, there is no reduction in strength and the accuracy of the machining hole is excellent and the side cutting edge 33 and the front cutting edge The life of the blade 34 is increased.

  In the cutting edge part 30, it is desirable that the front cutting edge angle κ ′ is set in a range of 15 ° to 45 °. By doing so, the contact range between the front cutting edge 34 and the end face of the machining hole is limited, so that an increase in cutting resistance is prevented, machining accuracy in boring is increased, and chipping of the cutting edge is prevented. .

  Further, it is desirable that the side cutting edge angle ψ is set in a range of −15 ° to −45 °. Then, since the contact range between the horizontal cutting edge 33 and the inner wall surface of the machining hole is limited, an increase in cutting resistance is prevented, the machining accuracy in boring is increased, and the horizontal cutting edge 33 is prevented from being lost. Is done.

  When viewed from a direction orthogonal to the rhombus surface of the chip body 20, a recess 36 is formed by cutting out a side ridge portion of the rhombus surface, and a horizontal cutting edge 33 is formed on the ridge line of the recess 36. The part 30 can be formed to a thickness that can be inserted into a pilot hole having a small diameter. Further, since the contact range between the horizontal cutting edge 33 and the inner wall surface of the machining hole is limited, an increase in cutting resistance is prevented, the machining accuracy in boring is increased, and the front cutting edge 34 is prevented from being lost. .

  Further, when viewed from a direction orthogonal to the rhombus surface of the chip body 20, a chamfered portion 37 is formed by cutting out a side ridge portion of the rhombus surface, and a front cutting edge 34 is formed at a ridge line of the chamfered portion 37. Therefore, the cutting blade portion 30 can be formed to a thickness that can be inserted into the pilot hole having a small diameter. Furthermore, since the angle formed by the top portion 35 is increased, the strength in the vicinity of the top portion 35 is increased, the accuracy of the processed hole is improved, and the life of the cutting blade is extended.

  The chip for boring is fixed by being fixed to the chip seat 12 of the tool body with the highly rigid chip body 20 by bringing the lower surface and two side surfaces of the chip body 20 into contact with the bottom surface and the wall surface of the chip seat 12, respectively. As a result, the clamping strength and clamping accuracy of the boring insert are increased. Therefore, chatter and chipping of the cutting edge due to the movement of the boring tool are prevented, and a long cutting edge life and high machining accuracy are realized.

  The shape of the chip body 20 is not limited to a rhombus, and may be any polygonal shape such as a triangle, square, rectangle, quadrangle, parallelogram, pentagon, or hexagon.

  Further, the means for fixing the boring tip to the tool body 10 is not limited to a tightening screw such as a bolt, but is replaced with a known clamping means such as clamp-on using a presser foot or wedge-on using a wedge member. It is possible.

It is a principal part front view of the boring tool to which this invention is applied. FIG. 3 is a side view of the boring tool shown in FIG. (A) is a top view of the boring tool shown in FIG. 1, (b) is an enlarged plan view of a cutting blade part. It is an enlarged plan view explaining the cutting situation by the boring tool shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Tool main body 12 Tip seat 20 Tip main body 21 The tip 30 of a corner part Cutting edge part 31 Rake face 32 Relief face 33 Horizontal cutting edge 34 Front cutting edge 35 Top part 36 Recessed part 37 Chamfering part

Claims (7)

A rake face is formed on at least one of the opposing polygon faces of the polygonal plate-shaped chip body, and a cutting edge having a horizontal cutting edge and a front cutting edge at a corner portion of the polygon face to be the rake face. When the portion is formed and viewed from the direction orthogonal to the polygonal surface, the top of the cutting edge is lower than the tip of the corner, and the horizontal cutting edge and the front cutting edge are of the polygonal surface. A chip for boring, characterized in that it is formed inside including a side ridge. 2. The boring tool according to claim 1, wherein a front cutting edge angle of the cutting blade portion is set in a range of 15 ° to 45 °. The insert for boring processing according to claim 1 or 2, wherein a side cutting edge angle of the cutting edge portion is set in a range of 15 ° to 45 °. When viewed from a direction orthogonal to the polygonal surface, a concave portion is provided that cuts out at least one side ridge portion of the polygonal surface, and at least one of the horizontal cutting edge and the front cutting edge is formed on the ridge line of the concave portion. The chip for boring processing according to any one of claims 1 to 3, wherein the chip is formed. When viewed from a direction perpendicular to the polygonal surface, a chamfered portion is formed by cutting out at least one side ridge portion of the polygonal surface, and at least one of a horizontal cutting edge and a front cutting edge is formed on the ridgeline of the chamfered portion. Either one is formed, The chip | tip for boring processing of any one of Claims 1-4 characterized by the above-mentioned. In the boring tool which mounts the chip for boring processing according to any one of claims 1 to 5 on a chip seat provided at a predetermined position of the tool body,
The corner portion of the polygonal surface that is the rake face is formed with a cutting edge portion having a horizontal cutting edge and a front cutting edge, and when viewed from a direction orthogonal to the polygonal surface, the top of the cutting edge portion is A boring tool characterized in that it is positioned lower than the tip of a corner portion, and the side cutting edge and the front cutting edge are formed inside including a side ridge portion of the polygonal surface. The boring tool according to claim 6, wherein the boring tool is detachably mounted on the tool body by bringing the lower surface and at least one side surface of the chip body into contact with the chip seat. .

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