JP2013163244A - Blade edge replaceable rotary cutting tool - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent an insert body from floating without using a clamp piece.SOLUTION: A cutting insert provided with an insert body 1 having a polygonal plate shape is detachably mounted to an insert mounting seat 16 formed at a tip outer circumference of a tool body 11 to be rotated around an axis with one of a pair of polygonal surfaces thereof turned in a tool rotating direction T as a rake face, the other closely fitted to a bottom surface 16a of the insert mounting seat 16 as a seating face, and side surfaces of the insert body 1 in contact with wall surfaces 16b, 16c of the insert mounting seat 16. Inclined surfaces 7a are formed on side surfaces of the insert body in such a manner as to incline inward the insert body 1 from the seating face side toward the rake face side, and protruding end surfaces 17a are formed on the wall surfaces 16b, 16c in such a manner as to incline to protrude inward the insert mounting seat 16 along the rotating direction T. The insert body 1 is mounted by making the inclined surfaces 7a abut on the protruding end surfaces 17a.

Description

  The present invention relates to a cutting edge replaceable rolling tool in which a cutting insert is detachably attached to an insert mounting seat formed on the outer periphery of a tip end of a tool body rotated about an axis.

  As a cutting insert attached to such a blade-tip-exchangeable rolling tool, for example, in Patent Document 1, a front surface and a back surface that form a substantially equilateral triangular plate and form this equilateral triangle are selectively scooped surfaces. There is described a negative type high-feed machining cutting insert in which a corner blade having an arc shape is formed at the corner portion, and a main cutting edge is formed on a side ridge portion of the front and back surfaces connected to the corner blade.

  This cutting insert is directed to the tip of the tool body rotated about its axis, with one of the front and back surfaces as a rake face in the direction of tool rotation, and one main cutting edge of the rake face is directed to the tool body tip side. The main cutting edge is attached so that a relatively small cutting angle, negative axial rake angle and radial rake angle are given, and usually it is fed at high speed in the direction perpendicular to the above-mentioned axis for cutting work. used. Since the cutting angle of the main cutting edge is relatively small, even if the feed is increased in this way, the thickness of the generated chips is reduced and efficient cutting can be performed.

  Further, Patent Document 2 describes a cutting insert in which two axial contact surfaces extending inwardly from a negative flank face merge at the center surface of the insert on the side surface of the cutting insert. Is inserted into the insert receiving pocket so that one of the axial contact surfaces hits the peripheral portion and the other adjacent to the applied axial contact surface is placed in the recess without hitting anywhere. A cutting tool assembly mounted by means of a clamping action according to is described.

Japanese Patent No. 3951766 Japanese Patent No. 4030720

  By the way, when performing high-feed machining as described in Patent Document 1, the main component force of the cutting resistance is directed to the main cutting edge directed to the tip side of the tool body used for cutting toward the rear in the tool rotation direction. Therefore, a force is generated on the cutting insert to lift the portion on the rear end side of the tool body opposite to the main cutting edge in the tool rotation direction. Particularly in high-feed machining, the cutting resistance is large, and the force to lift the insert is also large. Therefore, in the rolling tool described in Patent Document 1, the rake face of the cutting insert attached to the insert mounting seat by the clamp screw The tool main body rear end side portion is further pressed and fixed by a clamp piece.

  However, if the rake face is pressed down with the clamp piece to prevent the cutting insert from lifting up, the chips generated by the main cutting blade during cutting will come into contact with the clamp piece, and the clamp piece will wear due to scraping. There is a risk of inviting or damaging the work surface of the work material without stabilizing the direction in which the chips flow out. In addition, a clamp piece and a clamp screw for fixing the clamp piece are required, leading to an increase in the number of parts.

  On the other hand, Patent Document 2 describes that the insert is supported by the protruding portion provided in the insert against the rotation such that the cutting blade used for cutting the insert is lifted to the rotation direction side. There is no description of supporting the insert against a force that tends to lift the portion of the cutting insert on the rear end side of the cutting insert toward the tool rotation direction.

  The present invention has been made under such a background, and even if it is a cutting insert for high-feed processing, the insert body can be prevented from lifting without using a clamp piece or the like, and reliably and stably. An object of the present invention is to provide a cutting edge exchangeable rolling tool that can be mounted on an insert mounting seat.

  In order to solve the above problems and achieve such an object, the present invention provides an insert body having a polygonal plate shape on an insert mounting seat formed on the outer periphery of a tip end of a tool body that is rotated around an axis. Of the pair of polygonal surfaces facing the thickness direction of the insert body, with one of the polygonal surfaces facing the tool rotating direction as a rake surface and the other facing the tool rotating direction of the insert mounting seat A cutting edge exchangeable rolling tool that is attached to the bottom surface and is detachably attached by contacting the side surface of the insert body arranged around these polygonal surfaces with the wall surface of the insert mounting seat. On the side surface of the insert body, there is formed an inclined surface that inclines toward the inside of the insert body as it goes from the seating surface side to the rake surface side. The wall surface of the insert mounting seat is formed with a protruding end surface that is inclined so as to protrude toward the inner side of the insert mounting seat as it goes toward the tool rotation direction. The inclined surface is brought into contact with the protruding end surface. The insert body is attached to the insert mounting seat.

  In the blade-replaceable type rolling tool configured as described above, the tip end surface of the insert mounting seat wall surface that is inclined in the same direction on the inclined surface formed on the side surface of the insert body on which the flank surface is to be formed. Is brought into contact, the insert body is attached to the insert mounting seat in a state of being locked toward the tool rotation direction side. In addition, when cutting, when the back force or feed force of the cutting force is applied from the cutting edge formed on the rake face to the insert body toward the wall surface of the insert mounting seat on which the tip end surface is formed, The inclined surface that inclines toward the inner side of the insert body from the seating surface side of the insert body toward the rake face side is pressed against the protruding end surface that inclines toward the inner side of the insert mounting seat as it goes toward the tool rotation direction side. The insert body is pressed more firmly toward the bottom surface of the insert mounting seat.

  Therefore, according to the cutting edge replaceable rolling tool having the above-described configuration, the insert body can be prevented from being lifted in the direction of tool rotation without using a clamp piece or the like, and the cutting insert can be reliably and stably attached to the insert mounting seat. It can be attached and smooth cutting can be performed without causing entanglement of chips on the clamp piece, wear of the clamp piece, and increase in the number of parts. Furthermore, since the chip discharge direction does not become unstable due to the clamp piece, it is possible to control the outflow direction so that the chip does not hit the processing surface of the work material and to promote high-quality cutting. .

  Here, since the insert body tends to float on the fulcrum where the seating surface protrudes from the bottom surface of the insert mounting seat opposite to the cutting edge of the rake face on which the main component force acts, the inclined surface is the insert It is desirable that the protrusion end surface is brought into contact with the seating surface as far as possible in the thickness direction of the main body, and the protrusion end surface is positioned on the rake face side from the center of the insert body in the thickness direction. It is desirable that they are brought into contact with each other.

  In addition, the inclination angle of the inclined surface of the insert body with respect to the seating surface is larger or smaller than the inclination angle of the insert mounting seat with respect to the bottom surface of the insert mounting seat. The main body can be locked, but if the inclination angle of the inclined surface is larger than the inclination angle of the protruding end surface, the inclined surface can be brought into contact with the protruding end surface at a position further away from the seating surface. However, in these cases, since the inclined surface and the tip end surface come into contact with each other, the inclination angle of the inclined surface with respect to the seating surface and the inclination angle of the protruding end surface with respect to the bottom surface are equal to each other. Thus, it is desirable that the two come into contact with each other.

  Even when the inclination angle of the inclined surface with respect to the seating surface is equal to the inclination angle with respect to the bottom surface of the protruding end surface of the insert mounting seat, or when the inclination angles are different, these inclination angles are 70 °. It is desirable to be within a range of ˜85 °. If either one of the angles of inclination is greater than 85 ° and close to a right angle, the insert body may not be securely locked, and conversely, if the angle of inclination is less than 70 °, the insert body around the inclined surface There is a risk that the strength of the tool body and the strength of the tool body in the vicinity of the tip end surface are impaired and damage is likely to occur. Furthermore, in order to make the inclined surface by the protruding end face abut, it is desirable that the width of the inclined surface in the thickness direction is 1/6 or more of the thickness of the insert body.

  In addition to cutting inserts used for high-feed machining as described above, not only cutting inserts attached to ordinary cutting edge-replaceable rolling tools, but generally the insert body is correct as described in Patent Documents 1 and 2. It is assumed that it is formed rotationally symmetrical by a predetermined angle around the insert center line extending in the thickness direction, such as a polygonal plate, and is thus rotated by a predetermined angle and reattached to the insert mounting seat. The cutting blade is made usable. Therefore, in such a cutting insert, the inclined surface is formed so as to extend over the entire circumference of the insert main body, and thus the insert main body is rotated by a predetermined angle and reattached to the insert mounting seat. However, the lifting can be surely prevented.

  Further, in cutting inserts including those attached to such a normal cutting edge-replaceable cutting tool, the pair of polygonal surfaces of the insert main body can be reversed upside down as described in Patent Documents 1 and 2. In many cases, a cutting edge having a rake face formed on a pair of front and back polygonal surfaces can be used for attachment to the insert mounting seat. Therefore, in order to form the inclined surface in such a cutting insert, one of the side surfaces of the insert main body is formed with a convex portion protruding toward the outside of the insert main body, and the rake face side of the convex portion is formed. The inclined surface may be formed on the inclined surface. In this case, by forming one convex portion at the center portion of the side surface, the inclined surface can be brought into contact with the protruding end surface at a position on the rake face side from the center of the insert body in the thickness direction as described above. it can.

  On the other hand, when the insert main body is mounted on the insert mounting seat with the pair of polygonal surfaces turned upside down, on the other hand, on the side of the insert main body, facing the inner side of the insert main body. The concave surface may be formed, and the inclined surface may be formed on the inclined surface of the concave portion on the seating surface side. In this case, when only one concave portion is formed on the side surface, the inclined surface comes into contact with the protruding end surface at a position on the seating surface side from the center of the insert body in the thickness direction. If the concave portion is formed, the inclined surface can be brought into contact with the protruding end surface at a position on the rake face side from the center of the insert body as described above.

  As described above, according to the present invention, even if it is a cutting insert for high-feed processing, it is possible to prevent the insert body from being lifted without using a clamp piece or the like. The cutting insert can be securely and stably attached to the insert mounting seat without causing problems such as wear of the clamp piece and an increase in the number of parts, and preventing deterioration of the processed surface due to chips.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a tip end of a tool body (end mill body) showing a blade edge replaceable end mill which is a first embodiment of a blade edge replaceable rolling tool of the present invention. It is a top view of the blade-tip-exchange-type end mill shown in FIG. It is a side view of the blade-tip-exchangeable end mill shown in FIG. It is an enlarged front view of the blade-tip-exchangeable end mill shown in FIG. It is the top view which looked at the end mill main part tip part of the blade tip exchange type end mill shown in Drawing 1 from the insert center line direction. (A) AA sectional view in FIG. 5, (b) BB sectional view, (c) DD large sectional view. It is a perspective view of the cutting insert attached to the blade-tip-exchange-type end mill shown in FIG. It is a perspective view of the end mill main body of the blade-tip-exchangeable end mill shown in FIG. It is a perspective view of the tip part of a tool main part (end mill main part) which shows a cutting edge exchange type end mill which is a 2nd embodiment of a cutting edge exchange type cutting tool of the present invention. It is a perspective view of the cutting insert attached to the blade-tip-exchange-type end mill shown in FIG. It is the top view which looked at the end mill main part front-end | tip part of the blade-tip-exchange-type end mill shown in FIG. 9 from the insert center line direction. It is (a) AA sectional drawing in FIG. 11, (b) BB sectional drawing, (c) DD big sectional drawing.

  1 to 8 show a first embodiment of the present invention, and show a case where the present invention is applied to a blade edge replaceable end mill. The cutting insert in the present embodiment has a polygonal plate shape, specifically a regular polygonal plate shape made of a hard material such as cemented carbide, and the insert body 1 is formed in a substantially equilateral triangular plate shape in the present embodiment. In the middle of the pair of front and back polygonal surfaces of the insert body 1 having a substantially equilateral triangular shape, the thickness direction of the insert body 1 (the direction perpendicular to the drawing with respect to the cutting insert on the right side of FIG. 5 is shown. ˜ (c) in the vertical direction), and an attachment hole 2 for attaching the insert main body 1 to the end mill main body (tool main body) 11 of the blade edge replaceable end mill is opened. In addition, the inner peripheral surface of the mounting hole 2 is a tapered surface that gradually decreases in diameter toward the center of the insert body 1 in the thickness direction.

  Here, in this embodiment, the front and back polygonal surfaces of the insert body 1 pass through the center of the mounting hole 2 (center of the front and back polygonal surfaces) of the insert body 1 as shown in FIGS. It arrange | positions so that it may twist a little around the insert centerline C extended in the said thickness direction. In addition, the insert body 1 of the present embodiment in the form of an equilateral triangle has a rotationally symmetric shape of 120 ° around the insert center line C, and the front and back equilateral triangle surfaces orthogonal to the insert center line C. The front and back are symmetrical with respect to three imaginary straight lines passing through the centers of the three side surfaces of the insert body 1 arranged around the periphery of the insert body 1.

  A rake face 3 is formed on the front and back polygonal surfaces of the insert body 1, and a flank 4 is formed on the side surface of the insert body 1 disposed around these polygonal faces. . Further, at the intersecting ridge line portion between the rake face 3 and the flank face 4, a main cutting edge 5 is formed at each side ridge portion of both polygonal surfaces, and a corner blade is provided at each corner portion of the polygonal surface. 6 is formed, and the corner blade 6 has a convex curve shape such as a 1/3 arc as seen from the direction facing the rake face 3 in the insert center line C direction. In this embodiment, the main cutting edge 5 and the corner edge 6 are positioned on one plane perpendicular to the insert center line C in each of the front and back polygonal surfaces.

  The rake face 3 formed on the front and back polygonal surfaces is such that the outer peripheral portions along the main cutting edge 5 and the corner edge 6 are spaced apart from the main cutting edge 5 and the corner edge 6 toward the inside of the polygonal face. A positive rake face 3a that inclines so as to recede in the thickness direction toward the opposite polygon face side, and the periphery of the opening of the attachment hole 2 at the center of the polygon face is perpendicular to the insert center line C. A flat constraining surface 3b is provided. Note that the inclination angle of the positive rake face 3a is constant over the entire circumference of the rake face 3 in this embodiment. Further, the main cutting edge 5 and the corner blade 6 may be formed with lands or round honing.

  Furthermore, the three side surfaces arranged around the rectangular surfaces on the front and back sides of the insert body 1 are arranged at the center in the thickness direction of the insert body 1 as shown in FIGS. A convex portion 7 that is convex toward the outside of 1 is formed. As shown in FIGS. 6A to 6C in the cross section parallel to the insert center line C, each of the convex portions 7 on these three side surfaces is inserted toward the center of the insert body 1 in the thickness direction. Are formed in a convex V shape by a pair of inclined surfaces 7a extending toward the outer side of the two, and the intersecting ridge line between the pair of inclined surfaces 7a is the insert body 1 in the thickness direction in the present embodiment. It extends along a plane perpendicular to the insert centerline through the center.

  Further, the opening angle of the convex V-shape by the pair of inclined surfaces 7a is an obtuse angle of 140 ° to 170 °, so that the inclined surface 7a passes through the center of the insert body 1 in the thickness direction and is a plane perpendicular to the insert center line C. The inclination angle formed with respect to the constraining surface 3b of the polygonal surface on the opposite side with the thickness direction center in between is in the range of 70 ° to 85 °. Further, the width in the thickness direction of the convex portion 7 by the pair of inclined surfaces 7a is set to 1/3 or more of the thickness of the insert body 1 itself, and therefore the width in the thickness direction of each inclined surface 7a is the insert. The thickness of the main body 1 is 1/6 or more. Furthermore, in the present embodiment, the convex portion 7 formed by these inclined surfaces 7a is formed so as to continuously circulate over the entire circumference of the insert body 1, and only one strip is formed in the thickness direction.

  On the other hand, the side surface of the insert body 1 is made to be convex to the outside of the insert body 1 again on both sides in the thickness direction of the convex portion 7, and the flank 4 of the main cutting edge 5 and the corner blade 6 is It is formed in this convex part, respectively. In the present embodiment, the main cutting edge 5 has one end (clockwise direction around the insert center line C) as shown in FIG. 5 when viewed from the direction facing the rake face 3 as viewed in the insert center line C direction. (Side portion) 5a has a convex curve shape with a radius of curvature larger than the convex curve formed by the corner blade 6, and is opposite to the other end portion of the main cutting blade 5 opposite to this (centered on the insert center line C). The portion 5b in the clockwise direction) has a concave curve shape.

  Here, the concavo-convex curve formed by these main cutting edges 5 is such that the radius of curvature of the concave curve formed by the other end portion 5b is larger than the radius of curvature of the convex curve formed by the one end portion 5a. The length of the convex curve formed by 5a is set to be longer than the length of the concave curve formed by the other end 5b. The convex curve formed by the one end portion 5a of the main cutting edge 5 and the concave curve formed by the other end portion 5b are in contact with each other, and the one end portion 5a of the main cutting edge 5 and the one end portion 6a of the corner blade 6 connected thereto. , And the other end 5b of the main cutting edge 5 and the other end 6b of the other corner blade 6 connected thereto are also in contact with each other. In the present embodiment, the main cutting edge 5 and the corner edge 6 formed at the corners circulate in a smoothly continuous uneven curve.

  In this embodiment, the clearance angle β6 of the corner blade 6 is a negative angle side from the one end portion 6a of the corner blade 6 connected to the one end portion 5a of the main cutting blade 5 toward the other end portion 6b of the corner blade 6. It is made to become large toward. That is, the flank 4 is recessed from the corner blade 6 in the thickness direction toward the one end 6a from the other end 6 toward the one end 6a. Here, the clearance angle of the corner blade 6 in the present embodiment is a positive angle at the one end portion 6a of the corner blade 6, but 20 ° or less and 0 ° at the other end portion 6b. The angle is gradually increased toward the negative angle side.

  On the other hand, the clearance angle of the main cutting edge 5 is made larger at the one end portion 5a of the main cutting edge 5 toward the positive angle side than the other end portion 5b. In other words, the clearance angle of the other end portion 5b of the main cutting edge 5 is larger on the negative angle side than the one end portion 5b. Specifically, the clearance angle of the main cutting edge 5 is at a contact point (one end of the main cutting edge 5 and the corner blade 6) with the corner blade 6 connected to the one end 5a at the one end 5a of the main cutting edge 5. The positive angle is equal to or less than 20 ° at the one end portion 6a of the corner blade 6 and is kept constant at the corner blade 6 side of the one end portion 5a toward the other end portion 5b side of the main cutting blade 5. On the side opposite to the corner blade 6 of the one end portion 5a, it gradually increases toward the negative angle side toward the other end portion 5b. In other words, the clearance angle of the main cutting edge 5 is increased toward the positive angle side as it is separated from the other end portion 5b on the other end portion 5b side of the one end portion 5a.

  Further, the clearance angle of the main cutting edge 5 at the one end portion 5a that is increased toward the negative angle side toward the other end portion 5b in this way is the main contact point between the one end portion 5a and the other end portion 5b of the main cutting edge 5. In the embodiment, the negative is 0 °, and the other end portion 5b is constant with the clearance angle of 0 °. Therefore, in the present embodiment, one end portion 5a of the main cutting edge 5 and one end portion 6a of the corner blade 6 connected thereto, the other end portion 5b of the main cutting blade 5 and the other end portion 6b of another corner blade 6 connected thereto. , And the clearance angles of the main cutting edge 5 and the other end 5b of the main cutting edge 5 are equal to each other. It is designed to form an uneven curved surface that continues smoothly.

  In this way, the flank 4 connected to the main cutting edge 5 and the corner blade 6 is formed into an uneven curved surface, whereby the flank 4 on the front and back polygonal surfaces (regular triangle surface) side on the side surface of the insert body 1 is formed. The convex portion 7 to be formed in the shape of the convex surface 7 is formed in a convex V shape in which a section perpendicular to the insert center line C of the inclined surface 7a extends in a direction in which a portion along the main cutting edge 5 intersects an obtuse angle. Convex V-shape that is formed in a polygonal line and extends in a direction intersecting at an acute angle between each of the pair of main cutting blades 5 adjacent to each other via the corner blades 6 in the circumferential direction along the one end portion 5a and the other end portion 5b. It is formed in the eccentric hexagon shape made into the broken line shape which makes | forms. However, each corner of the eccentric hexagon is smoothly connected by a convex curve such as an arc.

  Further, in the cutting insert of this embodiment, the main cutting edge 5 and the corner edge 6 used at the time of cutting are rotated in the counterclockwise direction when the blade end replaceable end mill is viewed from the front side as shown in FIG. A right-handed cutting insert that forms a right blade, and when viewed from the direction facing the polygonal surface on which the rake face 3 of the main cutting edge 5 and the corner edge 6 is formed as described above, One end portion 6a of the corner blade 6 connected to one end portion 5a of the main cutting edge 5 is located at one end portion 5a of the main cutting edge 5 located on the clockwise direction side of the circumference of the square surface, and the counterclockwise direction The other end portion 6b of the other corner blade 6 is connected to the other end portion 5b of the main cutting blade 5 located on the side. The other polygonal surface as viewed from one polygonal surface side is slightly twisted toward the clockwise direction as shown in FIG.

  The end mill body 11 of the present embodiment, in which the cutting insert configured as described above is detachably attached, has an end mill body 11 having a substantially cylindrical shape centered on the axis O. The end mill body 11 The rear end side (upper side in FIGS. 2 and 3) is a cylindrical shank portion 12, and a neck portion 13 is provided on the front end side (lower side in FIGS. 2 and 3) of the shank portion 12. A blade portion 14 to which the cutting insert is attached is formed. Such a blade-tip replaceable end mill is usually fed in a direction perpendicular to the axis O while the shank portion 12 is gripped by the spindle of the machine tool and rotated around the axis O in the end mill rotation direction (tool rotation direction) T. Then, the workpiece is cut by the cutting insert of the above embodiment attached to the blade portion 14.

  A plurality of (two in this embodiment) tip pockets 15 are formed in the blade portion 14 so as to open to the outer periphery of the tip end portion of the end mill body 11, and the end mill rotation direction T side of these tip pockets 15 is arranged on the blade portion 14. Insert mounting seats 16 to which cutting inserts are attached are respectively formed at the front end portions of the facing wall surfaces. The end mill body 11 has a coolant hole 11a drilled along the axis O from the rear end surface of the shank portion 12 toward the front end side. The coolant hole 11a branches into a plurality at the blade portion 14, Opened toward the insert mounting seat 16 on the wall surface of each chip pocket 15 facing the rear side in the end mill rotation direction T.

  The insert mounting seat 16 has a flat bottom surface 16a that is recessed from the wall surface of the tip pocket 15 toward the rear side in the end mill rotation direction T and faces the end mill rotation direction T, and extends from the bottom surface 16a toward the end mill rotation direction T. 11 is provided with a wall surface 16b facing the inner peripheral side of the tip and a wall surface 16c facing the outer peripheral side of the tip, and is a recess that opens to the distal end surface and the outer peripheral surface of the end mill body 11 in the blade portion 14. The bottom surface 16a has a size and shape that is slightly smaller than the constraining surface 3b at the center portion of the rake face 3 of the insert body 1. A screw hole 16d is formed in the center portion of the bottom surface 16a perpendicular to the bottom surface 16a, and the wall surface 16b. , 16c is formed with a protrusion 17 projecting inward of the insert mounting seat 16 so as to extend in the circumferential direction of the bottom surface 16a.

  Of these, two protrusions 17 are formed on the wall surface 16c facing the outer peripheral side of the tip end of the end mill main body 11 so as to extend from the front end side of the end mill main body toward the rear end side. The protruding end surface 17a inside the insert mounting seat 16 of the strip portion 17 has an inclined surface 7a of the convex portion 7 at the portion along the main cutting edge 5 of the insert body 1 in the cross section orthogonal to the center line of the screw hole 16d. It is formed so as to exhibit a polygonal line shape extending in a direction intersecting the concave V shape with an obtuse angle equal to the convex V shape formed in a cross section perpendicular to the center line C.

  Further, one protrusion 17 is formed on the wall 16b facing the inner peripheral end of the end mill body 11, and the protrusion 17a of the protrusion 17 is a cross section that is also orthogonal to the center line of the screw hole 16d. 1a and 5b, one end 5a and the other end 5b of the pair of main cutting blades 5 adjacent to each other in the circumferential direction of the insert body 1 through the corner blades 6 together with the protrusion end surface 17a of the protrusion 17 on the rear end side of the wall surface 16c. Are formed so that the inclined surfaces 7a of the convex portions 7 in the section along the line form a concave V-shaped polygonal line extending in a direction intersecting at an angle equal to the acute angle of the convex V-shaped in a cross section orthogonal to the insert center line C. Has been. An escape portion 16e is formed between the protruding end surface 17a and the bottom surface 16a of each protruding portion 17 and between adjacent protruding portions 17.

  Further, these projecting end surfaces 17a are inclined surfaces that protrude from the inner side of the insert mounting seat 16 toward the front side in the end mill rotation direction T away from the bottom surface 16a in the center line direction of the screw hole 16d. The angle of inclination with respect to the center of the polygonal surface in which each of the pair of inclined surfaces 7a of the convex portion 7 having a convex V-shaped cross section of the insert body 1 is located on the opposite side with the center in the thickness direction of the insert body 1 in between. The inclination angle formed with respect to the planar constraining surface 3b is equal. Furthermore, the height from the bottom surface 16a of the projecting end surface 17a in the center line direction of the screw hole 16d is within the range of the width in the thickness direction of the inclined surface 7a located on the opposite side of the restraint surface 3b of the insert body 1. It is said that.

  In such an insert mounting seat 16, the cutting insert uses the rake face 3 of one polygonal surface on which the main cutting edge 5 used for cutting among the polygonal surfaces on the front and back sides of the insert body 1 is formed in the end mill rotation direction. The main cutting edge 5 is projected toward the tip end side of the end mill main body 11, and one end 5a of the main cutting edge 5 is positioned on the inner peripheral side of the end mill main body 11 and the other end 5b is set on the outer peripheral side. The other polygonal surface opposite to the one polygonal surface is used as a seating surface, and the restraint surface 3b at the center thereof is brought into close contact with the bottom surface 16a to be seated.

  Further, the insert in which the flank 4 of the other main cutting edge 5 on the opposite side of the corner blade 6 connected to the one end portion 5a of the main cutting edge 5 used for cutting is formed with the insert body 1 seated in this manner. The side surface of the main body 1 is opposed to the wall surface 16b facing the inner peripheral side of the tip end of the end mill main body 11 of the insert mounting seat 16, and the end mill rotation direction T side of the pair of inclined surfaces 7a of the convex portion 7 formed on this side surface. The directed inclined surface 7a on the one polygonal surface side is brought into contact with the inclined protruding end surface 17a of the protruding portion 17 formed on the wall surface 16b.

  On the other hand, the side surface of the insert main body 1 on which the flank 4 of the remaining main cutting edge 5 adjacent to the main cutting edge 5 used for the above-mentioned cutting through the corner edge 6 on the one end 5a side is formed as an insert mounting seat. 16 of the end mill main body 11 is opposed to the wall surface 16c facing the outer peripheral side of the end mill, and one of the pair of inclined surfaces 7a of the convex portion 7 formed on the side surface is also one polygonal surface directed toward the end mill rotation direction T side. The two inclined surfaces 7a on the side are brought into contact with the projecting end surfaces 17a of the two ridges 17 formed on the wall surface 16c.

  And by screwing the clamp screw 18 inserted through the mounting hole 2 of the insert body 1 into the screw hole 16d, the cutting insert is pressed against the bottom surface 16a by the polygonal surface of the constraining surface 3b. The tapered surface of the back surface of the head of the clamp screw 18 is in sliding contact with the tapered surface of the mounting hole 2 so that the inclined surface 7a on one polygonal surface side of the convex portion 7 on the two side surfaces facing the wall surfaces 16b and 16c is formed. Then, it is pressed against the projecting end surface 17a of the projecting ridge portion 17 in contact as described above, and is fixed and attached to the insert mounting seat 16. At this time, on the side surface of the insert body 1, only the inclined surface 7 a on the one polygonal surface side is brought into contact with and pressed against the protruding end surface 17 a, and is used as a seating surface of the pair of inclined surfaces 7 a. The inclined surface 7a on the other polygonal surface side and other portions do not come into contact with the wall surfaces 16b and 16c of the insert mounting seat 16.

  The main cutting edge 5 used for the cutting of the cutting insert attached in this way protrudes toward the distal end side of the end mill main body 11 at one end portion 5a having a convex curve shape as it goes from the inner peripheral side of the end mill main body 11 to the outer peripheral side. Later, toward the rear end side, the other end portion 5b having a concave curve shape is arranged so as to gradually extend toward the rear end side of the end mill body 11, and the substantially central portion of the one end portion 5a protrudes most toward the front end side of the end mill body. It is said. In addition, the main cutting edge 5 has an axis line on the side ridge portion of the polygonal surface on which the main cutting edge 5 is formed so that the whole of the one end portion 5a is located on the tip end side of the end mill body 11 with respect to the other end portion 5b. With respect to the plane orthogonal to O, the end mill body 11 is slightly tilted toward the rear end side toward the outer peripheral side of the end mill body 11.

  Further, as shown in FIG. 3, the cutting insert is attached by being slightly inclined so that the insert center line C is directed toward the rear end side in the axis O direction of the end mill main body 11 as it goes toward the rear side in the end mill rotation direction T. Thus, a negative axial rake angle is set for the main cutting edge 5 used for cutting. However, since the rake face 3 connected to the main cutting edge 5 is the positive rake face 3a as described above, the actual axial rake angle of the main cutting edge 5 does not become too large on the negative angle side. In addition, by giving a negative axial rake angle in this way, the rake face 3 of the other polygonal surface which is the seating surface of the insert body 1 is around the insert center line C with respect to the one polygonal surface. Combined with the twisted arrangement, the end mill body 11 is positioned on the rear end side of the main cutting edge 5 used for cutting.

  Further, the main cutting edge 5 used for this cutting is shown in FIG. 4 as viewed from the front end side of the end mill body 11 in the direction of the axis O, rather than a straight line parallel to the main cutting edge 5 and intersecting the axis O. The main cutting edge 5 is provided with a negative radial rake angle by being arranged so as to be positioned on the side of the rotation direction T, and so-called centering. In addition, by giving a negative radial rake angle to the main cutting edge 5 used for cutting in this way, other corner blades 6 connected to the outer peripheral side of the end mill body 11 at the other end 5b of the main cutting edge 5 are The blade portion 14 is projected to the outermost periphery of the end mill body 11, and as shown in FIG. 4, the insert body is located on the inner peripheral side with respect to the rotation trajectory around the axis O of the tip of the outermost periphery of the other corner blade 6. The rake face 3 of the other polygonal face of 1 is located.

  In the blade exchange type rolling tool (end mill) having such a configuration, the wall surface 16b of the insert mounting seat 16 that is inclined in the same direction on the inclined surface 7a of the convex portion 7 formed on the side surface of the insert body 1, When the projecting end surface 17a of the projecting ridge portion 17 formed on 16c abuts, the insert main body 1 is locked toward the end mill rotation direction T side, and the inclined surface 7a is formed on these projecting end surfaces 17a by the clamp screw 18. It is attached to the insert mounting seat 16 in a pressed state. In addition, when a back component force toward the rear end side of the end mill body 11 or a feed component force toward the inner peripheral side acts on the insert body 1 from the main cutting edge 5 used for cutting in the cutting process, the inclined surface 7a. Is further pressed against the tip end surface 17a.

  The inclined surface 7a and the projecting end surface 17a are arranged so that the inclined surface 7a is on the side of one polygonal surface that is the rake face 3 from the other polygonal surface of the insert body 1 in which the restraining surface 3b is a seating surface. The tip end surface 7a is inclined toward the inner side of the insert mounting seat 16 toward the end mill rotation direction T side, whereas the inclined end surface 7a is inclined in this manner. 7a is pressed against the projecting end surface 17a, so that the cutting insert is firmly pressed against and fixed to the bottom surface 16a of the insert mounting seat 16.

  For this reason, according to the edge-exchange-type end mill having the above-described configuration, even when used for high-feed machining, cutting is performed without pressing the rear end side portion of the end mill body 11 of the rake face 3 of the insert body 1 with a clamp piece or the like. It is possible to prevent the rear end side portion from being lifted by resistance. Therefore, the outflow direction is unstable due to the clamp piece being worn in the direction of chip entanglement or chipping due to the scraping of the chip due to the arrangement of the clamp piece on the rake face 3 or the direction of the outflow of the chip. Thus, it is possible to prevent the quality of the machined surface from being damaged by the chips hitting the machined machined surface. Needless to say, the clamp piece and the clamp screw for attaching the clamp piece are not required, so that the number of parts of the blade end replaceable end mill can be reduced and the cost can be reduced.

  Moreover, in this embodiment, the convex part 7 is formed in the thickness direction center part of the side surface of the insert main body 1, The thickness direction center of this convex part 7, ie, the center of the thickness direction of the insert main body 1, is formed. An inclined surface 7a on the rake face 3 side directed in the end mill rotation direction T is brought into contact with the protruding end face 17a. That is, the end mill extends in the direction of the insert center line C from the tangent line between the other polygonal constraining surface 3b, which is the seating surface of the insert body 1 serving as a lifting fulcrum, and the bottom surface 16a of the insert mounting seat 16 on the distal end side of the endmill body 11. Since the inclined surface 7a is brought into contact with the protruding end surface 17a at a position away from the rake face 3 facing the rotation direction T, the insert body 1 can be prevented from being lifted more reliably.

  In the present embodiment, the inclined surface 7a contacting the protruding end surface 17a of the insert body 1 has an inclination angle formed with respect to the other polygonal constraining surface 3b, which is the seating surface. The inclination angle is equal to the bottom surface 16a of the seat 16, and the inclined surface 7a and the protruding end surface 17a abut against each other, so that the insert body 1 can be pressed and locked more securely. It becomes.

  However, even if these inclination angles are slightly different from each other and the inclined surface 7a and the projecting end surface 17a are in contact with each other at the line contact, the inclined surface 7a is By being pressed against the protruding end surface 17a, the insert body 1 can be held in a state close to the surface contact. In this case, the inclination angle of the inclined surface 7a with respect to the restraining surface 3b is larger than the inclination angle of the projecting end surface 17a with respect to the bottom surface 16a from the restraining surface 3b of the other polygonal surface used as the seating surface. It is desirable because the inclined surface 7a can be brought into contact with the protruding end surface 17a at a distant position.

  Further, even when the inclination angle of the inclined surface 7a with respect to the constraining surface 3b and the inclination angle of the projecting end surface 17a with respect to the bottom surface 16a are equal or different, they are within the range of 70 ° to 85 ° as in the present embodiment. It is desirable to be done. If the inclination angle is larger than 85 ° and close to a right angle, it may be difficult to reliably lock the insert body 1 and prevent the floating. On the other hand, when the acute angle is smaller than 70 °, the strength of the peripheral portion of the inclined surface 7a in the convex portion 7 of the insert body 1 and the peripheral portion of the protruding end surface 17a of the protrusion 17 on the wall surfaces 16b and 16c of the insert mounting seat 16 are obtained. There is a risk that the strength is impaired and damage is likely to occur.

  Further, in order to ensure that the inclined surface 7a of the insert body 1 is brought into contact with the protruding end surface 17a of the insert mounting seat 16, it is desirable that the inclined surface 7a be wider, specifically as in this embodiment. The width in the thickness direction of the inclined surface 7a is preferably 1/6 or more of the thickness of the insert body 1, and the width of the convex portion 7 is preferably 1/3 or more of the thickness of the insert body 1. If the width of the inclined surface 7a is smaller than this, in the unlikely event that there is a dimensional error in the insert body 1 or the insert mounting seat 16, the inclined surface 7a is surely brought into contact with the projecting end surface 17a to lift the insert body 1 up. It may be difficult to prevent.

  On the other hand, in the present embodiment, the insert body 1 is formed into a regular polygonal plate shape (regular triangle plate shape) that is rotationally symmetric by a predetermined angle (120 °) around the insert center line C. A plurality of (three) main cutting edges formed on the side ridges and corners of one polygonal surface (regular triangular surface) by rotating around the line C by a predetermined angle and reattaching to the insert mounting seat 16 5 and the corner blade 6 can be used sequentially. And according to this, since the said convex part 7 and the inclined surface 7a are also formed over the perimeter of the insert main body 1, the main cutting edge 5 formed in any side ridge part is used for cutting. Even in this case, it is possible to reliably prevent the insert body 1 from being lifted.

  Further, in the present embodiment, the insert body 1 has a symmetrical shape so that the insert body 1 can be attached to the insert mounting seat 16 even when the pair of polygonal surfaces of the insert body 1 are reversed. By reversing and reattaching the insert body 1 to the insert mounting seat 16, the main cutting edge 5 and the corner edge 6 formed on both of the pair of polygonal surfaces can be reused. And the convex part 7 is equipped with the inclined surface 7a on the both sides of the thickness direction, and cuts the main cutting edge 5 of the side ridge part with the rake face 3 of any polygonal surface facing the end mill rotation direction T. Even in the case of use in the present embodiment, the projecting end face 17a of the insert mounting seat 16 is brought into contact with the inclined face 7a on the rake face 3 side used for this cutting rather than the center in the thickness direction of the insert body 1 in this embodiment. Again, the floating of the insert body 1 can be reliably prevented.

  However, in the first embodiment, the convex portion 7 is formed on the side surface of the insert body 1 as described above, and the inclined surface is the inclined surface 7a that abuts against the protruding end surface 17a. As in the second embodiment of the present invention shown in FIGS. 9 to 12, a concave portion 8 that is recessed inward is formed on the side surface of the insert body 1, and the slope of the concave portion 8 is formed on the wall surfaces 16 b and 16 c of the insert mounting seat 16. It is good also as the inclined surface 8a contact | abutted with the protrusion end surface 17a formed in this. 9 to 12, the same reference numerals are assigned to the parts common to the first embodiment shown in FIGS. 1 to 8, and the description thereof is omitted.

  Here, in this 2nd Embodiment, the recessed part 8 is further inserted body as it goes to the center of the said thickness direction, as shown to Fig.12 (a)-(c) in the cross section parallel to the insert centerline C. 1 is formed in a concave V shape by a pair of inclined surfaces 8a recessed inwardly, and one concave portion 8 is also provided in the thickness direction so as to circulate around the entire circumference of the insert body 1. Only formed. In addition, the insert body 1 having an equilateral triangular plate shape as in the first embodiment is rotationally symmetric by a predetermined angle (120 °) around the insert center line C and has a reverse-inverted symmetrical shape. The intersecting ridge line of the inclined surface 8a extends along a plane perpendicular to the insert center line C and passing through the center in the thickness direction.

  On the other hand, the protrusions 17 of the wall surfaces 16b and 16c of the insert mounting seat 16 of the end mill body 11 are formed on the bottom surface 16a side of the first embodiment in the present embodiment, and are used as a seating surface of the insert body 1. When the insert body 1 is seated with the other polygonal surface restraining surface 3b in close contact with the bottom surface 16a of the insert mounting seat 16, the inclined surface 8a on the other polygonal surface side of the pair of inclined surfaces 8a. The projecting end face 17a can be brought into contact with. Therefore, the inclination directions of the inclined surface 8a and the protruding end surface 17a that contact with each other are the same as those in the first embodiment, and the inclination angle and the range in which the inclined surface 8a and the protruding end surface 17a are formed are also in the first embodiment. Is equal to.

  Also in the second embodiment configured as described above, on the protruding end surface 17a inclined so as to protrude toward the inner side of the insert mounting seat 16 as it goes to the end mill rotation direction T side as in the first embodiment, Of the pair of inclined surfaces 8a of the recessed portion 8 on the side surface of the insert body 1, the insert body moves from the other polygonal surface side as the seating surface toward the one polygonal surface side directed in the end mill rotation direction T as the rake face 3 The insert body 1 can be locked by being brought into contact with the inclined surface 8a that is inclined toward the inside, and the inclined surface 8a is pressed against the projecting end surface 17a, so that the insert body 1 is firmly attached to the insert mounting seat. 16, the insert body 1 can be prevented from being lifted.

  Moreover, since it is the recessed part 8 formed in the side surface of the insert main body 1, the escape with the side surface in which the main cutting edge 5 used for cutting was formed, and the processed surface of a work material was ensured enough, and was stable. Cutting can be performed. Further, the flank 4 of the main cutting edge 5 and the corner edge 6 formed on the rake face 3 on the other polygonal surface side which is the seating surface is entirely outside the insert body 1 with respect to the recess 8. Since it is formed in the protruding part, even if the clamp screw 18 is loosened and the insert body 1 rattles, it can be prevented from falling off the insert mounting seat 16.

  In the second embodiment, only one recess 8 is formed, and the inclined surface 8a is opposite to the seating surface from the center in the thickness direction of the insert body 1 contrary to the first embodiment. Although it will be contact | abutted to the protrusion end surface 17a in the position of a polygonal surface side, when the thickness of the insert main body 1 is comparatively large etc., two or more arranged in the thickness direction on the side surface of the insert main body 1 The concave portion 8 is formed, and the inclined surface 8a on the other polygonal surface side of the concave portion 8 on the one polygonal surface side on which the rake face 3 used for cutting is formed is brought into contact with the protruding end surface 17a. Then, the insert body 1 can be locked at the position on the rake face 3 side from the center of the insert body 1 in the thickness direction. Similarly, in the first embodiment, a plurality of protrusions 7 may be formed on the side surface in the thickness direction.

DESCRIPTION OF SYMBOLS 1 Insert body 2 Mounting hole 3 Rake face 3a Positive rake face 3b Restraint face 4 Relief face 5 Main cutting edge 6 Corner blade 7 Convex part 7a Inclined surface of convex part 8 Recessed part 8a Inclined surface of concave part 8 End mill main body (tool main body) )
14 Blade portion 16 Insert mounting seat 17 Projection portion 17a Projection end surface of projection portion 17 18 Clamp screw C Insert center line O End mill body 11 axis T End mill rotation direction (tool rotation direction)

Claims (8)

  A pair of polygonal surfaces in which a cutting insert having a polygonal plate-like insert body on the insert mounting seat formed on the outer periphery of the tip end of the tool body that is rotated around the axis is oriented in the thickness direction of the insert body Of the insert body that is oriented around the polygonal surface, with one of them facing the tool rotation direction as a rake face and the other as a seating surface and facing the tool rotation direction of the insert mounting seat. A cutting edge exchangeable rolling tool that is detachably mounted with a side surface being brought into contact with the wall surface of the insert mounting seat, wherein the insert body is disposed on the side surface of the insert body from the seating surface side toward the rake surface side. An inclined surface that inclines toward the inner side of the tool is formed, and the wall surface of the insert mounting seat is formed on the tool rotation direction side. A protruding end surface that is inclined so as to protrude toward the inside of the insert mounting seat is formed, and the insert main body is mounted on the insert mounting seat by contacting the inclined surface to the protruding end surface. Cutting edge changeable rolling tool.   The cutting edge-replaceable type rolling tool according to claim 1, wherein the inclined surface is brought into contact with the protruding end surface at a position on the rake face side from the center of the insert body in the thickness direction. .   The cutting edge replacement type rolling tool according to claim 1, wherein an inclination angle of the inclined surface with respect to the seating surface is equal to an inclination angle of the protruding end surface with respect to the bottom surface.   4. The cutting edge-replaceable rolling tool according to claim 1, wherein the inclination angle is in a range of 70 ° to 85 °. 5.   The blade edge replacement according to any one of claims 1 to 4, wherein a width of the inclined surface in the thickness direction is not less than 1/6 of a thickness of the insert body. Type rolling tool.   The insert body is formed to be rotationally symmetrical by a predetermined angle around the insert center line extending in the thickness direction, and the inclined surface is formed to extend over the entire circumference of the insert body. The cutting edge replacement type turning tool according to any one of claims 1 to 5, wherein the cutting tool is replaceable.   The insert body can be attached to the insert mounting seat by turning the pair of polygonal surfaces upside down, and a convex portion that protrudes toward the outside of the insert body is formed on the side surface. The cutting edge exchangeable rolling tool according to any one of claims 1 to 6, wherein the inclined surface is formed on an inclined surface of the convex portion on the rake face side.   The insert body is configured such that the pair of polygonal surfaces are turned upside down and can be attached to the insert mounting seat, and the side surface has a recess recessed toward the inside of the insert body. The cutting edge replacement type rolling tool according to any one of claims 1 to 6, wherein the inclined surface is formed on an inclined surface of the concave portion on the seating surface side.

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