JP5275749B2 - Boring tool - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a boring tool with excellent workability for fine-adjustment of a cutting blade position, and high rigidity of a rotary holder. <P>SOLUTION: This boring tool 1 includes a pressuring nut 6 for pressuring a rear face of a tip end 51 of a cartridge 5 at a contact part 61; and an adjusting pin 7, which comprises an engagement part 71 engaged with an adjusting tool, a tapered part 7c having a tapered face 72 contacting an end face 62 of the pressurizing pin 6, first and second screw parts 7b, 7f screwed with first and second screw hole parts 34b, 34d formed on a rotary holder 3, and in which axes of the tapered part 7c, and the first and the second screw parts 7b, 7b are positioned on the same axial line Q. The adjusting pin 7 is moved forward and backward to the rotary holder 3, so as to move the pressurizing pin 6 contacting the tapered face 72 of the adjusting pin 7 in a radial direction of the rotary holder 3. A flexion amount of the tip end 51 of the cartridge 5 pressurized by the pressurizing nut 6 is changed, so as to adjust the position of the cutting blade 2 in the radial direction of the rotary holder 3. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a boring tool for cutting an inner peripheral surface of a workpiece to a predetermined inner diameter.

The boring tool used for precision line boring has a predetermined inner peripheral surface of the workpiece by finely adjusting the position of the cutting edge protruding in the radial direction of a long cylindrical rotary holder that rotates around its axis. The inner diameter is cut with high precision. Since fine adjustment of the cutting edge position is frequently performed, it is preferable that the cutting edge position is excellent in workability. Conventionally, as such a boring tool, for example, a tool equipped with a fine adjustment type micro cartridge disclosed in Patent Document 1 is known. This fine-adjustable micro-cartridge has a cylindrical bush that is detachably mounted on the rotary holder, a cartridge that has a cutting edge at the tip and is fitted into the bush via an adjustment nut, and is clamped on the proximal end side of the cartridge A washer fixed by a screw, and a disc spring interposed between the washer and the bush and biasing the cartridge toward its proximal end through the washer, and a cutting piece protruding in the radial direction of the rotary holder. The amount of protrusion of the blade can be finely adjusted. Fine adjustment of the protruding amount of the cutting blade is performed by rotating the adjustment nut with a work tool such as a spanner to cause the cartridge to appear and retract.
Japanese Patent No. 2950074

  However, when the fine adjustment type micro cartridge disclosed in Patent Document 1 is mounted, a large-sized bush containing a disc spring, a washer, an adjustment nut, etc. is accommodated in the rotary holder, so that the cartridge mounting portion with a large hole is rotated. It is necessary to form on the holder. Further, the protruding amount of the cutting blade is adjusted by rotating the adjustment nut of the fine adjustment type micro cartridge mounted on the cartridge mounting portion with a work tool such as a spanner. Therefore, a space for rotating a spanner or the like engaged with the adjustment nut is required, and it is necessary to form a flat portion by greatly notching the outer surface of the rotary holder.

  When the cartridge holder or the flat portion having a large hole is formed, the rigidity of the rotary holder is significantly reduced. For this reason, there is a problem that the rotary holder bends due to the cutting resistance at the time of cutting, the position of the cutting edge is not stable, and the processing accuracy is deteriorated. On the other hand, if the cutting speed is reduced in order to prevent the deterioration of the machining accuracy, there is a problem that it takes a machining time.

  In view of the above circumstances, an object of the present invention is to provide a boring tool that is excellent in workability for fine adjustment of the cutting edge position and has high rigidity of the rotary holder.

The present invention is a boring tool in which a cutting blade protruding in a radial direction of a rotary holder cuts an inner peripheral surface of a workpiece, the cutting blade is provided on a surface side of a front end portion, and a rear end portion is A cartridge that is fixed to the rotary holder and is elastically deformable, a pressing pin that presses the tip with the back side of the tip of the cartridge coming into contact with one end, an engagement that engages with the adjustment tool, and the pressing A tapered portion having a tapered surface that contacts the other end of the pin, and a first threaded portion that is screwed into a first threaded hole formed in the rotating holder on the engaging portion side of the tapered portion; A second threaded portion that engages with a second threaded hole formed in the rotating holder on the opposite side of the tapered portion from the engaging portion, and a hole formed in the rotating holder. and a first insert portion and the second insert portion that, the tapered portion, said first screw The second threaded portion, the first insert portion, and the axis of the second insert portion is provided with an adjustment pin positioned on the same line, one end of the adjustment pin than the tapered portion The first fitting portion is positioned on the other end side of the adjustment pin with respect to the taper portion, and the adjustment pin moves forward and backward with respect to the rotating holder. By moving the pressing pin in contact with the tapered surface in the radial direction of the rotary holder, and changing the amount of deflection of the tip of the cartridge pressed by the pressing pin, the radial direction of the rotary holder The position of the cutting blade is adjusted.

  According to the present invention, as disclosed in Patent Document 1, it is not necessary to house a cartridge having a large-sized bush containing a washer, an adjustment nut, and the like in a rotating holder. For this reason, the size of the cartridge mounting portion formed on the rotary holder is reduced. In addition, as in the case of using the fine adjustment type micro cartridge disclosed in Patent Document 1, an adjustment tool such as a hexagon wrench is engaged with the engagement portion of the adjustment pin without using a spanner or the like inserted into the adjustment nut. The position of the cutting blade can be adjusted by rotating it. Therefore, it is not necessary to form notches necessary for using a spanner or the like on the outer surface of the rotary holder. As a result, the rigidity of the rotating holder becomes high, and the rotating holder is prevented from being bent by the cutting resistance at the time of cutting, so that the position of the cutting blade is stabilized and excellent processing accuracy can be obtained. . In addition, the cutting speed can be increased while maintaining excellent machining accuracy, and the machining time can be reduced.

  Furthermore, the position of the cutting blade can be adjusted only by rotating an adjustment tool such as a hexagon wrench engaged with the engagement portion of the adjustment pin. Further, when the adjustment tool is rotated by one rotation, the amount of movement of the adjustment pin is one pitch of the first and second screw holes, and if the taper angle of the tapered surface is gentle, the pressing pin The change in the position of the cutting edge accompanying the movement of is very small. Therefore, the position of the cutting edge can be easily finely adjusted. Further, the first and second threaded portions are respectively engaged with the first and second threaded hole portions, and on both sides of the tapered surface that receives pressure such as cutting resistance from the cutting blade via the pressing pin, Since the first and second screw portions are respectively positioned, the adjustment pin does not easily loosen.

  In the present invention, it is preferable that at least one set of the first screw portion and the first screw hole portion or the second screw portion and the second screw hole portion is a taper screw. In this case, since the friction is larger than when all are normal parallel screws, the adjustment pin does not loosen more easily.

Further, in the present invention, the adjusting pin, Ru provided with a fitted portion to be fitted into the formed rotary holder hole. Accordingly , the position of the cutting blade is further stabilized without the adjustment pin being easily bent.

  A boring tool 1 according to an embodiment of the present invention will be described with reference to the drawings.

  Referring to FIG. 1, a boring tool 1 is a line bar used for precision line boring. The boring tool 1 is formed on the work piece by the cutting blade 2 protruding in the radial direction of the rotary holder 3 by rotating the rotary holder 3 relative to the work piece (not shown) around the axis O. The inner peripheral surface of the long cylindrical hole is cut to a predetermined inner diameter with high accuracy.

The boring tool 1 includes a rotary holder 3 that is a long cylindrical tool body, and a plurality of cartridges 5 to which a cutting blade 4 having a cutting blade 2 is fixed and attached to the rotary holder 3. The cartridge 5 is mounted such that the fixed cutting blades 4 are alternately positioned along the axis O on the distal end side and the proximal end side of the rotary holder 3. The rotary holder 3 has a substantially long cylindrical shape made of cemented carbide, steel, or the like, and has a shank portion 31 at the base end thereof.

  Referring to FIGS. 2 and 3, the boring tool 1 further presses the cartridge 5 in correspondence with each cartridge 5 to determine the position of the cutting edge 2, that is, the radial protrusion amount of the rotary holder 3. A pressing pin 6 to be changed and an adjusting pin 7 for adjusting the position of the pressing pin 6 are provided. The cutting blade 2 moves along an axis A that extends in the radial direction of the rotary holder 3 (the vertical direction in FIGS. 2 and 3) through the axis O.

  The rotary holder 3 accommodates a cartridge mounting portion 32 for mounting the cartridge 5, a pressing pin receiving hole 33 for storing the pressing pin 6 and sliding the pressing pin 6 therein, and an adjusting pin 7. An adjustment pin housing portion 34 is formed in which the adjustment pin 7 is screwed and moved forward and backward.

The cartridge mounting portion 32 is formed by cutting the outer peripheral surface of the rotary holder 3 into a key shape extending along the direction of the axis O. The pressing pin accommodation hole 33 extends along the axis A from the bottom surface of the cartridge mounting portion 32 on the axis O side, and is formed in a circular cross section. On the bottom surface of the cartridge mounting portion 32 on the axis O side, a screw hole 35 that is spaced apart from the pressing pin housing hole 33 along the axis O direction and extends in parallel is formed. The adjustment pin accommodating portion 34 communicates perpendicularly with the pressing pin accommodating hole 33 and is formed so as to extend along the radial axis Q of the rotary holder 3 through the axis O. That is, the axis Q is orthogonal to the axis A. One end (the right end in FIG. 2) of the adjustment pin accommodating portion 34 is opened at the outer peripheral surface of the rotary holder 3. The adjustment pin accommodating part 34 is formed with a large-diameter hole 34a formed in a circular cross section in order from the opened one end side to the other end side, and a tapered female thread that is reduced in diameter from one end side to the other end side on the inner peripheral surface. Tapered screw hole portion (first screw hole portion) 34b, medium diameter hole portion 34c formed in a circular cross-section having a smaller diameter than the large diameter hole portion 34a, and screw hole portion (second screw hole formed with an internal thread on the inner peripheral surface) 34d, and the other end has an opening on the outer peripheral side of the rotary holder 3 and a small-diameter hole 34e formed in a circular cross-section having a smaller diameter than the insertion medium-diameter hole 34c. In addition, the adjustment pin accommodating part 34 may not have the small diameter hole part 34e.

  The cartridge 5 is formed in a substantially prismatic shape, and a fixed seat 52 for fixing the cutting blade 4 is formed on the surface side (left side in FIG. 2, upper side in FIG. 3) of the distal end portion 51 in the longitudinal direction. . Note that, regardless of the mounting direction of the cartridge 5 to the rotary holder 3, the side to which the cutting blade 4 is attached is referred to as a tip 51. The cutting blade 4 is pressed and fixed using a presser foot 53 in a state where the cutting blade 2 is placed on the fixed seat 52 so as to protrude from the surface of the cartridge 5. The cutting blade 4 is a CBN throw-away tip made of a polycrystalline boron nitride polycrystal, and has a substantially hexagonal flat plate shape. On the other hand, a through hole 55 penetrating in the thickness direction is formed at the rear end portion 54 in the longitudinal direction of the cartridge 5. The cartridge 5 accommodated in the cartridge mounting portion 32 is mounted on the rotary holder 3 when the screw 56 inserted into the through hole 55 is screwed into the screw hole 35. The cartridge 5 is formed with a slit 57 on the back surface side (lower side in FIG. 3) between the front end portion 51 and the rear end portion 54, and can be elastically deformed in the front and back direction.

  The pressing pin 6 is formed in a substantially cylindrical shape that can be inserted into the pressing pin accommodation hole 33. The end surface 61 of the pressing pin 6 that contacts the back surface of the cartridge 5 is formed in a shape suitable for moving the cutting blade 2 along the axis A by sliding in the pressing pin receiving hole 33 of the pressing pin 6. Here, it is formed in a shape slightly raised toward the center. Further, the end surface 62 of the pressing pin 6 that contacts the adjusting pin 7 is suitable for the pressing pin 6 to slide in the pressing pin receiving hole 33 according to the screwing distance in the adjusting pin receiving portion 34 of the adjusting pin 7. Here, it is formed in a shape that slightly protrudes toward the center.

  The adjustment pin 7 is accommodated in the adjustment pin accommodating portion 34, and has an engagement portion 71 formed at a base end portion thereof in a shape suitable for engagement with an adjustment tool such as a hexagon wrench. The adjustment pin 7 includes, in order from the proximal end side to the distal end side, a large-diameter portion (fitting portion) 7a formed in a circular cross section that can be fitted into the large-diameter hole portion 34a. A tapered thread portion (first threaded portion) 7b formed with a tapered male screw that is reduced in diameter and screwed into the tapered threaded hole portion 34b, and a tapered surface 72 that is diameter-reduced from the proximal end side to the distal end side are formed on the outer peripheral surface. Tapered portion 7c, medium diameter portion (fitting portion) 7d formed in a circular cross section that can be fitted in medium diameter hole portion 34c, small diameter portion 7e formed in a circular cross section smaller in diameter than medium diameter portion 7d, and on the outer peripheral surface It has a threaded portion (second threaded portion) 7f formed with a male thread that is screwed into the threaded hole portion 34d.

  Next, the position adjustment of the cutting edge 2 in the boring tool 1 configured as described above will be described.

  An adjustment tool such as a hexagon wrench engaged with the engagement portion 71 of the adjustment pin 7 is rotated and screwed so that the adjustment pin 7 in the adjustment pin housing portion 34 is pushed into the rotary holder 3. Then, the diameter of the tapered surface 72 that contacts the end surface 62 of the pressing pin 6 is increased, and the pressing pin 6 slides in the pressing pin housing hole 33 toward the cartridge 5. Thereby, the end surface 61 of the pressing pin 6 presses the back surface of the front end portion 51 of the cartridge 5, and the cartridge 5 is elastically deformed to bend the front end portion 51, so that the cutting blade 2 protrudes radially outward of the rotary holder 3. Move along the axis A.

  On the other hand, the adjustment tool engaged with the engagement portion 71 of the adjustment pin 7 is rotated in the reverse direction and is screwed so that the adjustment pin 7 in the adjustment pin housing portion 34 is pulled out of the rotary holder 3. Then, the tapered surface 72 that contacts the end surface 61 of the pressing pin 6 is reduced in diameter, and the pressing pin 6 slides in the pressing pin housing hole 33 in the direction away from the cartridge 5. As a result, the amount of extrusion by which the end surface 61 of the pressing pin 6 presses the back surface of the tip portion 51 of the cartridge 5 is reduced, the elastic deformation of the cartridge 5 is restored, the amount of bending of the tip portion 51 is reduced, and the cutting blade 2 Moves along the axis A so as to be recessed radially inward of the rotary holder 3.

  As described above, in the boring tool 1, as disclosed in the above-mentioned Patent Document 1, it is not necessary to accommodate a cartridge having a large-sized bush containing a washer, an adjustment nut and the like in the rotary holder 3. Therefore, the size of the cartridge mounting portion 32 formed on the rotary holder 3 is reduced. Further, as in the case of using the fine adjustment type micro cartridge disclosed in Patent Document 1, an adjustment tool such as a hexagon wrench is attached to the engaging portion 71 of the adjustment pin 7 without using a spanner or the like inserted into the adjustment nut. The position of the cutting blade 2 can be adjusted by engaging and rotating. Therefore, it is not necessary to form notches necessary for using a spanner or the like on the outer surface of the rotary holder. Accordingly, the rigidity of the rotary holder 3 becomes high, and the rotary holder 3 is prevented from being bent by the cutting resistance at the time of cutting, so that the position of the cutting edge 2 is stabilized and excellent machining accuracy can be obtained. It becomes possible. In addition, the cutting speed can be increased while maintaining excellent machining accuracy, and the machining time can be reduced.

  Further, in the boring tool 1, the position of the cutting edge 2 can be adjusted only by rotating an adjusting tool such as a hexagon wrench engaged with the engaging portion 71 of the adjusting pin 7. Further, when the adjustment tool is rotated by one rotation, the movement amount of the adjustment pin 7 is one pitch of the taper screw hole portion 34b and the screw hole portion 34d, and the taper angle of the taper surface 72 is gentle. The position change of the cutting blade 2 accompanying the movement of the pressing pin 6 is minute. Therefore, the position of the cutting blade 2 can be easily finely adjusted. The adjustment pin 7 is configured such that the taper screw portion 7b is screwed with the taper screw hole portion 34b and the screw portion 7f is screwed with the screw hole portion 34d with respect to the adjustment pin housing portion 34. Since the taper screw part 7b and the screw part 7f are respectively located on both sides of the taper surface 72 that receives pressure such as cutting resistance from the cutting blade 4 through the screw, they are not easily loosened. The adjustment pin 7 has a large-diameter portion 7a fitted into the large-diameter hole portion 34a and an intermediate-diameter portion 7d fitted into the medium-diameter hole portion 34c with respect to the adjustment pin housing portion 34, and Since the large-diameter portion 7a and the medium-diameter portion 7d are located on both sides of the tapered surface 72, the position of the cutting blade 2 is stabilized without the adjustment pin 7 being easily bent.

The form of the boring tool 1 is an example of the present invention and is not limited. For example, the case where the engaging portion 71 of the adjustment pin 7 is provided on the large diameter portion 7a side has been described. However, the engaging portion 71 of the adjustment pin 7 may be provided on the screw portion 7f side. In this case, an extending portion 7g (see FIG. 4) extending from the screw portion 7f so as to be close to the outer peripheral surface of the rotary holder 3 may be provided. Further, the tapered thread portion 34b of the engaging portion 71 side from the tapered surface 72, respectively tapered female thread on the tapered threaded section 7b, although a tapered male thread, the tapered threaded hole 34b, respectively normal parallel internal thread in the tapered threaded hole 7b A parallel male screw may be formed. Further, the opposite side of the threaded hole portion 34d and the engaging portion 71 from the tapered surface 72, respectively normal parallel female screw thread portion 7f, were formed parallel male thread, respectively tapered female screw threaded hole 34d, the threaded portion 7f, tapered An external thread may be formed.

Further, the adjustment pin 7 does not easily loosen, but the boring tool 1 may be provided with a loosening prevention mechanism. For example, referring to FIG. 4, the loosening prevention mechanism can be configured using a hollow set screw (holoset) 8. In this case, a screw hole 36 communicating with the small-diameter hole 34 e of the adjustment pin accommodating portion 34 orthogonally and extending to the outer peripheral surface in the opposite direction to the cartridge mounting portion 32 is formed in the rotary holder 3. On the other hand, the adjusting pin 7 is provided with an extending portion 7g that extends from the screw portion 7f so as to be close to the outer peripheral surface of the rotary holder 3 and is formed in a circular cross section having a smaller diameter than the small diameter hole portion 34e. Then, a hexagon wrench engaged with the head of the enamel set screw 8 screwed into the screw hole 36 is rotated, and the tip of the enamel set screw 8 is pressed against the extending portion 7g to adjust the adjustment pin 7 To prevent loosening. The adjustment pin 7 receives pressure from the cartridge mounting portion 32 side via the pressing pin 6, but receives a pressure in a direction opposite to this pressure from the enamel set screw 8, so that effective loosening prevention can be performed.

The schematic perspective view which shows the boring tool which concerns on embodiment of this invention. The II-II line | wire sectional view taken on the line of FIG. FIG. 3 is a sectional view taken along line III-III in FIG. 2. Sectional drawing of the boring tool provided with the loosening prevention mechanism.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Boring tool, 2 ... Cutting blade, 3 ... Rotating holder, 4 ... Cutting blade, 5 ... Cartridge, 6 ... Pressing pin, 7 ... Adjustment pin, 7a ... Large diameter part (mounting part), 7b ... Taper screw Portion (first screw portion), 7c ... taper portion, 7d ... medium diameter portion (fitting portion), 7f ... screw portion (second screw portion), 32 ... cartridge mounting portion, 33 ... pressing pin receiving hole, 34 ... Adjusting pin accommodating portion, 34a ... Large diameter hole portion, 34b ... Tapered screw portion (first screw hole portion), 34c ... Medium diameter hole portion, 34d ... Screw portion (second screw hole portion), 51 ... Front end portion, 54 ... rear end portion, 61 ... end face (one end), 62 ... end face (other end), 71 ... engaging portion, 72 ... tapered surface.

Claims (2)

The cutting blade protruding in the radial direction of the rotary holder is a boring tool for cutting the inner peripheral surface of the workpiece,
The cutting edge is provided on the surface side of the front end portion, the rear end portion is fixed to the rotary holder, and is an elastically deformable cartridge;
A pressing pin that presses the tip by contacting the back side and one end of the tip of the cartridge;
An engaging portion that engages with the adjustment tool, a tapered portion that has a tapered surface that contacts the other end of the pressing pin, and a first portion formed on the rotary holder on the engaging portion side of the tapered portion. A first threaded portion that is screwed with the threaded hole portion, and a second threaded portion that is threadedly engaged with a second threaded hole portion formed in the rotary holder on the side opposite to the engaging portion from the tapered portion. When, a first insert portion and the second insert portion to be fitted into the formed rotary holder bore, the tapered portion, the first threaded portion, the second threaded portion, The first fitting portion and the second fitting portion are provided with adjustment pins on the same line.
The first fitting part is located on one end side of the adjustment pin with respect to the taper part, and the second fitting part is located on the other end side of the adjustment pin with respect to the taper part,
By bending the adjustment pin forward and backward with respect to the rotating holder, the pressing pin that contacts the tapered surface is moved in the radial direction of the rotating holder, and the leading end of the cartridge that is pressed by the pressing pin is bent. A boring tool characterized by adjusting the position of the cutting blade in the radial direction of the rotary holder by changing the amount.   The boring machine according to claim 1, wherein at least one set of the first screw portion and the first screw hole portion or the second screw portion and the second screw hole portion is a taper screw. tool.

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