JP2009072855A - Throw-away tip and cutting tool - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a throw-away tip repetitively mounted on a holder with more accuracy and whose protrusion length is adjustable in the longitudinal direction, and also to provide a cutting tool using the same. <P>SOLUTION: The throw-away tip 10 to be inserted into a hole 110 of the cutting tool holder comprises a blade part 20 approximately round-bar-shaped extending in the axial direction and formed on the front end side in the axial direction, and a shank part 30 formed on the base end side. Herein, an engaging part 50 is provided which is locked to the holder 100 in the direction of rotation around the axis, and is movable in the axial direction. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a throw-away tip having a substantially round bar shape, and more particularly to a throw-away tip and a cutting that increase the circumferential mounting accuracy and repeated mounting accuracy when mounting on a holder, and allow adjustment of the protruding length in the longitudinal direction. Related to tools.

  When machining small precision parts in an inner diameter machining tool used for inner diameter machining of workpieces, for example, boring, inner grooving, inner diameter threading, etc., it is generally rod-shaped and has a cutting edge at one end in the longitudinal direction. In many cases, an inner diameter machining tool is used in which the formed throw-away tip is inserted into a hole provided at the tip of the holder, and the cutting blade is protruded from the holder by a predetermined length and fixed.

  This type of conventional throw-away tip has a substantially rod shape, and has a cutting edge at one end in the longitudinal direction and a tapered cut surface at the other end. The throw-away tip is fixed by abutting the cut surface with a fixing member attached to the holder (see, for example, Patent Document 1).

Another conventional throw-away tip has a concave V-shape or a convex V-shape upper and lower surfaces that can mesh with a convex V-shaped or concave V-shaped tip restraining surface constituting the tip mounting seat at the tip of the shank. (For example, refer to Patent Document 2).
JP 2004-74322 A JP 2004-82234 A

The improvement request for this type of bore machining tool is:
(1) Since the accuracy of the product is severe, the circumferential mounting accuracy and the repeated mounting accuracy are good. (2) Since the number of tools is limited, one tool can cope with various machining depths (3 ) Low cost. Regarding these points, in the conventional throw-away tip described in Patent Document 1, the circumferential positioning of the throw-away tip is accurately performed by the tapered cut surface. However, in order to adjust the protruding length in the longitudinal direction, the position in the longitudinal direction of the cut surface must be changed, or the position in the longitudinal direction of a fixing member such as a pin must be changed, which is complicated. Subtle adjustments were also difficult.

  In the conventional throw-away tip described in Patent Document 2, the protruding length can be adjusted. However, molding of the upper and lower surfaces of the throw-away tip and the tip restraining surface of the tip mounting seat is not easy and the cost may increase.

  The present invention has been made in order to solve the above-described problem. The throw-away tip and the throw-away tip that can adjust the protruding length in the longitudinal direction while improving the accuracy of attaching the throw-away tip to the holder and repeatedly attaching accuracy. It aims at providing the cutting tool using.

In order to solve the above problems, the present invention has the following configuration.
The invention according to claim 1 is a throw-away tip that is inserted into a hole of a holder of a cutting tool, has a substantially round bar shape extending in the axial direction, and a blade portion formed on the tip side in the axial direction; A shank portion formed on the base end side, and an engagement portion that locks the holder in a rotational direction around the axis and enables movement in the axial direction. It is a throwaway chip.

According to the invention according to claim 1, since the throw-away tip is locked around the axis with respect to the holder by the engaging portion provided in the throw-away tip and is movable in the axial direction. When this throw-away tip is attached to the holder, the attachment accuracy in the rotational direction around the axis and the repeated attachment accuracy are excellent, and the protruding length of the blade portion from the holder can be freely adjusted.
Further, since the cutting force acting in the rotation direction is received by the engaging portion at the time of cutting, the attachment accuracy and the repetitive attachment accuracy of the throw-away tip in the rotation direction are maintained, and deterioration of the accuracy of the processed portion is prevented. .
In addition, the shank portion has a basic cylindrical shape as in the past, and is merely provided with an engaging portion. Therefore, the shank portion can be easily formed, and an increase in cost can be suppressed.

The invention according to claim 2 is the throwaway tip according to claim 1, wherein the engaging portion is an engaging concave portion recessed from an outer peripheral surface of the shank portion or a protruding engaging convex portion. It is.
According to the invention of claim 2, since the throw-away tip is locked around the axis with respect to the holder by the engagement recess or the engagement projection, and is made movable in the axial direction. When attaching the away tip to the holder, it has excellent mounting accuracy in the rotational direction around the axis and repeated mounting accuracy, and the protruding length of the blade portion from the holder can be freely adjusted.
Further, during cutting, the cutting resistance acting in the rotational direction is received by the recessed wall surface of the engaging recess or the raised wall surface of the engaging convex portion, so that the throwing tip has a mounting accuracy in the rotating direction and a repeated mounting accuracy. This maintains the accuracy of the machined portion.

The invention according to claim 3 is characterized in that the engaging portion extends in parallel with the axis and the cross-sectional shape perpendicular to the axis of the engaging portion is the same. It is a throw-away chip as described.
According to the invention which concerns on Claim 3, regardless of the moving amount | distance of the axial direction of a throw away tip, it is excellent in the attachment precision of the rotation direction around an axis line, and repeated attachment precision. For this reason, deterioration in accuracy of the processed portion is prevented.

According to a fourth aspect of the present invention, the holder is formed with a hole into which the throwaway tip according to any one of the first to third aspects is inserted, and abuts on the engaging portion of the throwaway tip. By this, it is the cutting tool characterized by including the latching | locking part which makes it possible to adjust the protrusion length of the said blade part while latching the said throw away tip around the said axis line.
According to the fourth aspect of the present invention, the cutting tool engages the throw-away tip in the rotational direction around its axis by the contact of the engaging portion provided on the holder with the engaging portion provided on the throw-away tip. In addition to being able to adjust the protruding length of the blade portion, it is possible to adjust the protruding length of the blade portion from the holder as well as being excellent in mounting accuracy and repeated mounting accuracy of the throw-away tip in the rotating direction. .
Furthermore, the shank part of the throw-away tip and the hole of the holder have a basic cylindrical shape as usual, and only the engaging part and the locking part are attached to each, so that the shank part and the hole are formed. Is easy and the increase in cost can be suppressed.

According to the present invention, the throw-away tip is locked around the axis with respect to the holder by the engaging portion provided on the throw-away tip and is movable in the axial direction. When attaching to the holder, the mounting accuracy in the rotational direction around the axis and the repeated mounting accuracy are excellent, and the protruding length of the blade from the holder can be adjusted freely.
Further, since the cutting force acting in the rotation direction is received by the engaging portion at the time of cutting, the attachment accuracy and the repetitive attachment accuracy of the throw-away tip in the rotation direction are maintained, and deterioration of the accuracy of the processed portion is prevented. .

  A throw-away tip and a cutting tool to which the present invention is applied will be described with reference to the drawings. FIG. 1 is a perspective view of a throw-away tip to which the present invention is applied. FIG. 2 is a perspective view of a tool body of a cutting tool to which the present invention is applied. 3 is a perspective view showing a state in which the throw-away tip shown in FIG. 1 is mounted on the tool body shown in FIG. FIG. 4 is a view for explaining the cross-sectional shape of the engaging portion provided in the shank portion of the throw-away tip.

  As shown in FIG. 1, the throw-away tip 10 has a substantially round bar shape, and includes a blade portion 20 provided on the distal end side in the longitudinal direction and a shank portion 30 provided on the proximal end portion side. In the throw-away tip 10, at least the cutting edge 21 is made of a hard metal material such as cemented carbide, cermet, ceramics, or an ultra-high pressure sintered body such as diamond or cBN. A single groove 40 is cut out on the outer peripheral surface of the tip portion of the blade portion 20, and a cutting blade 21 extending from the outer peripheral end toward the center side in the radial direction is formed on the tip ridge of one wall surface of the groove 40. Is formed. An engaging portion 50 is provided on the outer peripheral surface of the cylindrical shank portion 30. The engaging portion 50 extends in parallel to the axis on the opposite side of the outer peripheral end of the cutting blade 21 across the axis of the throw-away tip 10. Further, the engagement portion 50 is a concave groove-like engagement recess having a rectangular cross-sectional shape, and one end in the longitudinal direction thereof opens to the proximal end surface of the shank portion 30, and the other end of the shank portion 30. Near the tip. In addition, the engaging part 50 is good also as an engaging convex part which protrudes from the outer peripheral surface of the shank part 30. FIG.

  The engaging portion 50 is formed by cutting out the outer peripheral surface of the cylindrical shank portion 30 by, for example, cutting, grinding, or electric discharge machining. Alternatively, the engaging portion 50 is formed at the same time when the hard metal material is powder-extruded.

  As shown in FIG. 2, the holder 100 has a round bar shape, and a hole 110 penetrating the both end faces is formed at the center thereof. The hole 110 only needs to open at least on the tip surface of the holder 100. The inner wall surface of the hole 110 is provided with a locking portion 150 that protrudes from the inner wall surface toward the center of the hole 110. The locking portion 150 extends in parallel with the axis of the hole 110. Further, the locking portion 150 has a ridge shape having a rectangular shape in cross section similar to that of the engaging portion 50, and one end in the longitudinal direction reaches the front end surface of the holder 100, and the other end portion is It reaches the vicinity of the bottom end of the hole 110.

  The locking portion 150 protruding from the inner wall surface of the hole 110 is formed integrally with the inner wall surface or attached as a separate member. As a method of attaching as a separate member, a method of joining by brazing, welding or the like, a method of fastening using screws, bolts or the like, and a method of fitting such as shrink fitting are adopted.

  The shank portion 30 of the throw-away tip is inserted into the hole 110 of the holder while engaging the engaging portion 50 provided on the outer peripheral surface thereof with the engaging portion 150 provided on the inner wall surface of the hole 110 of the holder. Both the engaging portion 50 and the locking portion 150 have the same cross-sectional shape over the entire length in the longitudinal direction of the throw-away tip 10 and can be fitted and relatively moved along the axis of the hole 110. ing. Therefore, the shank portion 30 of the throw-away tip can be inserted into and removed from the hole 110 of the holder, and the protruding length L from the front end surface of the holder 100 to the forefront of the cutting blade 21 can be adjusted.

  As shown in FIG. 3, the throw-away tip 10 adjusted to a desired protruding length L is fixed to the holder 100 by a fixing member 200. As the fixing member 200, a hexagon socket head cap screw that is screwed into a female screw hole 120 provided along the diameter direction of the holder 100 as shown in FIG. 3 is used. When the fixing member 200 presses the outer peripheral surface of the shank portion 30 of the throw-away tip in the diametrical direction, the throw-away tip 10 is detachably fastened to the holder 100.

The throw-away tip 10 having the configuration described above includes an engaging portion 50 provided on the outer peripheral surface of the shank portion 30 along the longitudinal direction, and an engaging portion 150 provided on the inner wall surface of the hole 110 of the holder. Are fitted and can be moved relatively along the axis of the hole 110, so that the throw-away tip is moved around the axis with respect to the holder by an engaging portion provided on the throw-away tip. Because it is locked and movable in the axial direction, when attaching this throw-away tip to the holder, it has excellent mounting accuracy in the rotational direction around the axis and repeated mounting accuracy, and the protruding length of the blade from the holder Can be adjusted freely.
Further, the cutting resistance acting in the rotational direction of the throw-away tip 10 during cutting is received by the side wall surface of the locking portion 150 that is raised in addition to the hole 110 of the holder that holds the shank portion 30 of the throw-away tip 10. For this reason, the throw-away tip 10 is firmly and stably fixed to the holder 100.

  When the center of the fixing member 200 is shifted so as not to intersect the axis of the holder 100, the throw-away tip 10 is rotated in the rotation direction around the axis by the pressing of the fixing member 200, and the engagement of the shank portion is increased. The side wall surface in which the joint portion 50 is depressed is abutted against the protruding side wall surface of the locking portion 150 of the hole of the holder. Therefore, the repeatability of the mounting accuracy is further increased, and the movement of the throw-away tip 10 in the rotational direction is prevented, so that the effect of preventing the accuracy of the processed portion from being deteriorated becomes extremely high.

The throw-away tip shank part 30 and the holder hole 110 are formed in a conventional basic cylindrical shape, and are provided with an engaging part 50 and an engaging part 150, respectively. And the formation of the hole 110 is very easy, and the increase in cost can be suppressed as much as possible.
In the present throw-away tip 10, the engaging portion 50 that is recessed from the outer peripheral surface of the shank portion 30 is formed by being cut out by, for example, cutting, grinding, or electric discharge machining. In order to avoid an increase in the molding cost of the shank part 30, it is desirable that both the shank part 30 and the engaging part 50 are formed simultaneously with the powder extrusion molding of the hard metal material.

  Since the throwaway tip engaging portion 50 is formed so as to reach the base end face of the shank portion 30, a sufficient range of movement of the throwaway tip 10 in the axial direction is secured, and the protruding length of the blade portion 21 is ensured. Large adjustment amount of L can be obtained.

  Since the cross-sectional shape of the engaging portion 50 of the throw-away tip and the locking portion 150 of the holder is the same in the entire length in the longitudinal direction, the shank portion 30 is moved in the longitudinal direction with respect to the holder 100. Thus, the protruding length L of the cutting blade 21 can be adjusted. In addition, the adjustment work of the protrusion length L is very easy, and deterioration of the mounting accuracy in the rotation direction around the axis of the throw-away tip 10 is also prevented. When the locking portion 150 of the holder is formed so that the cross-sectional shape in the vicinity of the tip surface of the holder is gradually reduced in size as it approaches the tip surface, the locking portion 50 of the throw-away tip is locked to the holder. Since it can insert easily when making it fit in the part 150, it is preferable.

  The throw-away tip 10 having the shank portion 30 inserted into the hole 110 of the holder is fitted with the engaging portion 50 so as to be movable in the axial direction with respect to the locking portion 150 of the hole, whereby the cutting blade 21 Since the accuracy of mounting in the circumferential direction is improved, the accuracy of the processed portion is improved, and the protrusion length L from the holder 100 can be adjusted, which makes the adjustment work very easy.

  The cross-sectional shape of the engaging portion 50 and the locking portion 150 provided in the shank portion 30 of the throw-away tip and the hole 110 of the holder is not limited to a rectangular shape, and is illustrated in, for example, FIGS. Thus, the cross-sectional shape such as a curved shape such as an arc shape or a U shape, or an inverted trapezoidal shape or an L shape can be appropriately changed. In the case of an arc-shaped cross-sectional shape, the force acting on each position of the arc is dispersed in each direction, which is advantageous in terms of strength.

  The present invention is not limited to the embodiments described above, and can be changed and added without departing from the scope of the invention. For example, the engaging part 50 may be provided in addition to the shank part 30 of the throw-away tip. Correspondingly, the locking portion 150 may also be provided other than the hole of the holder. In addition, the shape of the engaging portion 50 of the throw-away tip may be changed to a ridge shape that protrudes radially outward from the outer peripheral surface of the shank portion 30, and the locking portion 150 of the holder also corresponds to this. It may be changed to a concave groove shape recessed from the inner wall surface of the hole 110 of the holder. Moreover, the engaging part 50 and the latching | locking part 150 may be provided not only in one place in the circumferential direction or a longitudinal direction but in two or more places. Further, the fixing member 200 for fixing the throw-away tip 10 may be provided not only at one place but also at two or more places.

It is a perspective view of a throw away tip to which the present invention is applied. It is a perspective view of the tool main body of the cutting tool to which this invention is applied. It is a perspective view which shows the state which mounted | wore the tool main body shown in FIG. 2 with the throw away tip shown in FIG. (A)-(d) is a figure explaining the modification of the cross-sectional shape of the groove part provided in the shank part of the throw away tip.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Throw away tip 20 Blade part 21 Cutting blade 30 Shank part 50 Engagement part 100 Holder 110 Holder hole 120 Female thread hole 150 Locking part 200 Fixing member

Claims (4)

A throw-away tip inserted into a hole of a holder of a cutting tool,
It has a substantially round bar shape extending in the axial direction, and includes a blade portion formed on the distal end side in the axial direction, and a shank portion formed on the proximal end side,
A throw-away tip, wherein the throw-away tip is provided with an engaging portion that locks the holder in a rotational direction around the axis and enables movement in the axial direction. The throw-away tip according to claim 1, wherein the engaging portion is an engaging concave portion that is recessed from an outer peripheral surface of the shank portion or an engaging convex portion that protrudes. The throw-away tip according to claim 1 or 2, wherein the engaging portion extends in parallel with the axis and has the same cross-sectional shape perpendicular to the axis of the engaging portion. A hole into which the throw-away tip according to any one of claims 1 to 3 is inserted is formed in the holder, and the throw-away tip is brought into contact with an engaging portion of the throw-away tip. A cutting tool comprising a locking portion that locks around the axis and allows adjustment of a protruding length of the blade portion.

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