KR102120631B1 - Cutting tool and cutting insert for thread whirling - Google Patents

Abstract

(Task) In the cutting tool for thread whirling, after re-grinding the cutting edge of the cutting insert on the inclined surface side, when the cutter insert is fixed to the cutter body, the blade end position is not required to be adjusted again. To be able to.
(Solution) The cutting insert 201 forms an equilateral trapezoidal shape, has an inner angle of the lower side and each angle as a tool angle α, and has an inclined surface 213 at the edge of the lower side. It is assumed that the cutting edge 210 is provided, and the clamp portion of the cutter body 101 is a first restraining wall surface 323 that restrains the inclined surface side 213b of the cutting insert 201 as a first constrained surface. And a second restraining wall surface 325 that restrains the front flank surface side 215b of the cutting insert 201 as a second constrained surface, and the position of the protruding direction of the blade end 211 during fixing thereof. The decision was made by pressing the first constrained surface to the first constrained wall surface 323 and the second constrained wall to the second constrained wall surface 325.

Description

Cutting tools and cutting inserts for thread whirling operations{CUTTING TOOL AND CUTTING INSERT FOR THREAD WHIRLING}

The present invention relates to a cutting tool used for threading by thread whirling and a cutting insert suitable for the cutting tool.

There are various processing methods for forming a male screw (hereinafter, also referred to as "screw") on the outer circumferential surface of a shaft member (round bar), which is a workpiece, and one of them is a thread whirling processing method. In this machining method, while rotating a shaft member (material) as a workpiece at a low speed (for example, 5 to 50 rpm), one lead portion of a screw (one row screw) to be formed in one rotation is transferred in the axial direction, while one Alternatively, the cutting edge (blade end) of a plurality of cutting inserts (or bites) is larger than the outer diameter of the shaft member and is rotated at high speed (for example, 2000 to 7000 rpm) in the same rotational direction along the circular orbit that the outer diameter inscribes, thereby making the circular orbit In a state in which the inclination of the lead angle is given so that cutting in a direction corresponding to the lead angle of the screw is obtained at one place of, intermittent cutting is performed at a cutting depth of the thread. According to this processing method, since it is possible to cut a screw in a predetermined range from the front end to the rear in one feed of the shaft member, it is suitable for high-threaded screws, long screws, or large-threaded threads. It is being used.

However, the above-described cutting tool used for thread whirling is mounted through a cutter body (cutting tool body) forming an annular shape on the spindle head of the processing machine. On the other hand, one or a plurality of cutting inserts for threading are positioned to protrude in the cutting depth direction (inside of the annular shape) of the shaft member whose blade end is a workpiece at a predetermined position (clamp portion) in the cutter body forming the annular shape. Determined and fixed. The basic structure for fixing such a cutting insert is, for example, fixing a cutting insert to a clamp portion (pocket) of a holder mounted on the cutter body, and fixing the holder on which it is fixed to a predetermined position (holder mounting portion) of the cutter body. It has a configuration. In the fixing of such a holder, adjustment and positioning of the blade end position (diameter direction, circumferential direction) is made by adjusting the fixing position in correspondence with the outer diameter (screw diameter) of the shaft member to be processed by screwing with a bolt or the like. . In addition to this, it is also known to fix a cutter insert body to a cutter body by using a holder equipped with a blade end position adjusting device, and perform the adjustment by means of an adjusting device provided by the holder.

Cutting inserts used for such threading include, for example, a polygonal plate shape such as a parallelogram, a trapezoid, a triangle, and the like, and a cutting edge having an inclined surface and a front flank surface with an acute corner (blade end) interposed therebetween. There is one. Such a cutting insert, for example, makes the main surface of the base for fixing in the plate-shaped portion of the cutting insert abut against the bottom surface of the clamp portion (pocket) in the holder, but is opposite to the inclined surface. It is fixed by positioning (patent document 1, patent document 2) by making (bottom surface of the base) abut against the seat surface of the pocket and the opposite side of the front flank surface (back of the base) to the other seat surface of the pocket. In addition, in the cutting insert having a through hole, it is common that the screw insert is inserted into the through hole formed in the main surface of the fixing base and then screwed into the screw hole formed in the bottom surface of the pocket.

By the way, even in thread whirling, when the sharpness of the cutting edge decreases due to wear of the cutting edge or the occurrence of chipping, the throw-away method that uses this once and discards the cutting edge by re-grinding (re-grinding) the cutting edge. There is a re-grinding method to reuse and re-use the sharpness of. In the re-grinding method, the tool life can be prolonged according to the number of polishing times as much as the polishing value applied to a new (unused) cutting insert. In the cutting insert used in this way (hereinafter also referred to as ``polishing''), this polishing is usually planar polishing of an inclined surface. The reason is that the cutting edge in a cutting insert for thread cutting has a shape when viewed from an inclined surface (blade shape), that is, the flank surface forming the cutting edge is a thread to be machined, a thread groove (for example, a triangular screw) This is because it is a convex (uneven) shape corresponding to a triangular surface, and cannot be handled by simple planar polishing, whereas it can be solved by planar polishing in polishing of inclined surfaces.

Patent Document 1: Japanese Patent Publication No. 10-58233 Patent Document 2: Japanese Patent Application Publication No. 2008-296311

However, when re-polishing the inclined surface of the cutting insert of the above-described structure, since the thickness of the blade end is removed as much as polished, the inclined surface of the cutting insert after polishing becomes lower than that of the surface before polishing (original). . On the other hand, the angle of the cutting edge (hereinafter referred to as "tool angle") between the inclined surface and the front flank surface constituting the cutting edge in the cutting insert for thread cutting is usually an acute angle. Therefore, when such a cutting edge is polished, the edge is displaced (retracted) in a direction away from the edge of the edge than the original position before polishing. Therefore, when the re-polished cutting insert is fixed again to the clamp portion of the holder (the original position of the pocket), as described above, the opposite side of the inclined surface (bottom surface of the base) is placed on the seat surface of the pocket and the opposite side of the front flank surface. If the surface (back side of the base) is positioned to abut against the other seat surface of the pocket, the position of the blade tip is the lower side (downward) and the back side (backward) by the amount of polishing from the original position (tip end position) before polishing. Because it is displaced by, it is at a different edge position from before polishing. Therefore, it may not be used as it is, depending on the required processing precision or the amount of repolishing.

The reason for this is that in the case of the machining mode in which the cutting by the transverse feed, which gives a suitable cutting depth to the cutting edge, is repeated several times while gradually increasing the cutting depth little by little, as in the case of cutting by normal turning, even if the edge positions are slightly different. It is possible to respond by changing the amount of cutting depth, but this is not possible in thread whirling. That is, in the threading form, in which a cutting depth equal to the height of the thread is obtained from the beginning, such as thread whirling, so that machining is terminated by one transverse feed, displacement of the position of the blade end affects the machining dimension (precision). give.

Therefore, when the cutting insert of the above-described positioning structure is fixed again to the holder after re-grinding, it is usually necessary to adjust the fixing position of the holder with respect to the cutter body after the fixing. In addition, since such an adjustment operation is required each time re-grinding, when the re-grinding is used, the adjustment operation time increases, resulting in a change in cutting edge or a reduction in processing efficiency. In addition, even if a holder equipped with a blade position adjusting device capable of fine adjustment of the blade edge by an adjusting device provided in the holder is used, the adjustment operation itself cannot be omitted.

In the present invention, in the cutting tool used for thread whirling, the cutting edge of the cutting insert is re-polished to fix the cutter body to the cutter body, thereby omitting adjustment of the blade end position to quickly and easily exchange the cutting edge. It is intended to provide a cutting tool for thread whirling that can be performed (hereinafter also referred to as a'cutting tool' or simply a'tool') and a cutting insert suitable for this tool.

The invention described in claim 1, the cutter body forming an annular shape, and And a cutting insert fixed to a clamp portion in a clamp portion or a holder mounted so that the mounting position is adjustable on the cutter body, and the cutting edge of the cutting edge is a work piece in an annular inner side of the cutter body. A cutting tool for thread whirling that is positioned by protruding a predetermined amount in the cutting depth direction of

The cutting insert has a cutting edge and a base for fixing to the clamp portion, and a tool angle, which is an intersection angle between the inclined surface and the front flank surface constituting the cutting edge, forms an acute angle, and the inclined surface And the surface of the inclined surface at the base is brought into contact with a virtual one plane, and also has a predetermined polishing value for repolishing.

When the front flank surface-side surface 215b in the base indicates the tool angle, the intersection of the straight line and the inclined surface along the front flank surface-side surface is formed to be the same as the angle of the tool angle,

The clamp portion has a first restraining wall surface that restrains the inclined surface side as a first constrained surface, and a second restraining wall surface that constrains the front flank surface side as a second constrained surface,

Positioning the protruding direction of the blade tip in fixing the cutting insert with respect to the clamp portion, the first constrained surface on the first constraining wall surface, and the second constrained surface on the second constraining wall surface, respectively. It is characterized by being in charge by pressing.

The invention described in claim 2 is a cutting tool for thread whirling, according to claim 1, wherein the inclined surface of the cutting insert and the inclined surface side surface of the base form one plane.

The invention according to claim 3 is a cutting tool for thread whirling, according to claim 1, wherein the front flank surface of the cutting insert and the front flank surface side surface of the base form one plane.

The invention described in claim 4 is a cutting tool for thread whirling according to claim 2, wherein the front flank surface of the cutting insert and the front flank surface side of the base form a plane.

The invention according to claim 5, wherein the cutting insert forms a plate shape in an isosceles trapezoid, and the lower side and the inner angle of each angle in the isosceles trapezoid are tool angles. It is a cutting tool for thread whirling, characterized by having two identical cutting edges in a structure having inclined surfaces at both ends of the lower side.

The invention according to claim 6 is a cutting insert having a cutting edge and a base for fixing to a clamp portion,

A tool angle, which is an acute angle of an inclined surface and a front flank surface constituting the cutting edge, forms an acute angle, and is formed so that the inclined surface and the inclined surface side surface of the base contact the virtual one plane, and for re-polishing. In addition to having a predetermined polishing value,

When the front flank surface side surface in the base indicates the tool angle, the intersection of the straight line and the inclined surface along the front flank surface side surface is formed to be the same as the angle of the tool angle,

It is characterized in that the inclined surface side surface and the front flank surface side surface are formed to form a constrained surface for fixing to the clamp portion.

The invention described in claim 7 is a cutting insert according to claim 6, wherein the inclined surface of the cutting insert and the inclined surface side surface of the base form one plane.

The invention according to claim 8 is a cutting insert according to claim 6, wherein the front flank surface of the cutting insert and the front flank surface side surface of the base form one plane.

The invention described in claim 9 is a cutting insert according to claim 7, wherein the front flank surface of the cutting insert and the front flank surface side of the base form one plane.

The invention according to claim 10, according to any one of claims 6 to 9, wherein the cutting insert forms a plate shape in an isosceles trapezoid, and the lower side and the inner angle of each angle in the isosceles trapezoid are tool angles. It is a cutting insert characterized by having two identical cutting edges in a structure having an inclined surface at both ends of the lower side.

In the cutting insert (cutting insert for threading) in the present invention, the front flank surface has a thread to be machined, such as a trapezoidal screw, because the bottom of the bone of the screw (screw groove) is parallel to the axis of the screw. On a cutting edge with a front cutting edge parallel to the axis of the processing of the bottom of the bone, the flank of the front cutting edge is the front flank, but for example, the machining of a screw without a parallel bottom, such as a triangular screw or a round screw. When the tip of the blade end in an inclined surface, such as a cutting edge used in an angle or arc, is called the front cutting edge, and the flank surface corresponding to the cutting edge is used as the front flank surface.

In the cutting tool of the present invention as set forth in claim 1, when the sharpness of the cutting edge is lowered, the cutting insert is removed and the inclined surface and the surface of the inclined surface in the base portion are removed such that wear or chipping damage is removed. The entire surface is polished at the same polishing value. In the cutting insert after this planar polishing (re-polishing), the inclined surface including the inclined surface and the first constrained surface becomes as low as the polishing value, but according to the configuration of the present invention, this is used as before the polishing. By positioning in the protruding direction, the position of the blade tip becomes the original position irrespective of the amount or amount of polishing. That is, the cutting insert after polishing is polished until the first confined surface abuts the first confined wall surface while sliding the second confinement surface along the second confinement wall surface of the clamp portion in the state before polishing and also as a guide. Just move as much as possible. Therefore, the position of the blade edge after polishing becomes the original position. Therefore, according to the present invention, since it is not necessary to adjust the positioning for fixing each re-grinding as in the prior art, it is possible to return the blade tip to the correct blade tip position simply and quickly. Therefore, it is possible to improve the efficiency of the cutting edge exchange operation and, moreover, the machining.

Further, in the present invention, the cutting insert having the structure described in claim 1 may be sufficient, and the inclined surface and the inclined surface side surface of the base may be formed so as to be in contact with an imaginary plane even if there is a concave portion. As described, it is preferable for simplification of the structure that both of them form a plane. In addition, for the front flank surface side surface in the base, when indicating the tool angle, it is sufficient that the size of the intersection of the straight line and the inclined surface along the front flank surface side surface is the same as the angle of the tool angle. That is, if the front flank surface side of the base forms an angle equal to the front flank angle of the front flank surface, when the tool angle is displayed, it is formed in a parallel or identical straight line drawn along the front flank surface It's good, and both don't have to be on one plane. However, as described in claims 3 and 4, it is preferable for simplification of the structure to have one plane.

The cutting insert may have one cutting edge for positioning of the cutting edge, but two cutting edges are formed such that the inclined surface faces the inclined surface on the inclined surface, and the blade ends face each other in the plane. It is good to have a structure provided. In this way, the two cutting edges can be simultaneously polished by planar polishing the entire surface of the inclined surface and the inclined surface, so that the life of the cutting edge can be doubled at the same polishing operation cost. I can plan it.

In this case, as described in claim 5, it is preferable that the cutting insert is formed in a plate shape in an equilateral trapezoid. In this case, since the bottom surface (the upper side of the trapezoid) facing the inclined surface (the lower side of the trapezoid) becomes parallel to the inclined surface, the plane serving as the upper side of the trapezoid is used as a reference surface for polishing the inclined surface, thereby simplifying the plane polishing. It is because it can plan. That is, the cutting insert used in the present invention can be embodied as, for example, forming a plate shape in a parallelogram shape, and using two cutting edges as two tool acute angles, but as described in claim 5 This is because two cutting edges can be regenerated by polishing once by making an equilateral trapezoid.

The cutting insert according to claims 6 to 9 is provided in a clamp part of an annular cutter body constituting the cutting tool for thread whirling according to claims 1 to 5 or a holder mounted to the cutter body so that the mounting position is adjustable. It is suitable as a cutting insert that is fixed to the clamp portion of. However, the cutting inserts according to claims 6 to 10 are used not only for cutting tools for thread whirling, but also for cutting tools (bytes) used for ordinary threading with turning and turning, and other processing by turning. It can also be applied as constituting the cutting tool used. That is, as well as the cutter body, the inclined surface side and the front flank surface side are confined to two clamp portions for fixing the insert formed at the tip thereof, such as a holder for a cutting tool having a bite and constituting it. When two restraining surfaces are provided for restraining as a surface, since the clamping portion is not fixed, the adjustment of the positioning of the cutting edge for fixing is not required for each re-grinding, so the cutting edge is quickly and easily. Can be returned to the correct edge position. Therefore, even in normal threading or other machining by a lathe, the cutting edge can be exchanged, and furthermore, the efficiency of the machining can be improved.

As such, the cutting inserts described in claims 6 to 10 are not limited to thread whirling. That is, the clamping portion for fixing the insert in the holder for the bite, the first constraining wall surface for restraining the inclined surface side of the cutting insert as the first constrained surface, and the second constrained surface for the front flank surface And a second restraining wall surface that is restrained as a surface, and the first confined wall surface is fixed to the first restraining wall surface for positioning of the blade end in the fixing direction with respect to the clamp portion, It can also be applied to a cutting tool using a holder having a configuration that is responsible for pressing the second constrained surface on the second constraining wall surface. Furthermore, the efficiency of processing can be aimed at.

1 is a perspective view for explaining one embodiment of a cutting tool for thread whirling according to the present invention.
FIG. 2 is a front view of the cutting tool for thread whirling of FIG. 1 (front view).
3 is an enlarged view of a portion P1 of FIG. 2.
Fig. 4A is a right side view of Fig. 2, and B is a sectional view taken along line S1-S1 in Fig. 2.
5 is a perspective view (enlarged perspective view) illustrating a cutting insert for thread cutting used in the cutting tools of FIGS. 1 and 2;
FIG. 6 is a view of the cutting insert of FIG. 5 from each side, A is a front view when showing the tool angle α (view from arrow A1), B is a view from the inclined side (view from arrow A2) ), C is the view from the front flank side (drawing from arrow A3), D is the view from the bottom, and E is the central longitudinal section of A.
7 is a front view for explaining the cutter body constituting the cutting tool of FIGS. 1 and 2;
8 is a view (enlarged view) illustrating a holder mounted to the cutter body constituting the cutting tools of FIGS. 1 and 2, wherein A is a front view and B is a right side view thereof.
Fig. 9 shows the cutting insert fixed to the holder in the cutting tools of Figs. 1 and 2, wherein A is a front view of the fixed state at the time of a new product, and B is a front view of the fixed state after re-grinding on the inclined surface side. .
10 shows another example of the cutting insert fixed to the holder, where A is a new front view in a fixed state and B is a front view in a fixed state after repolishing on the inclined surface side.

An embodiment in which the cutting tool for thread whirling of the present invention is embodied will be described in detail with reference to FIGS. 1 to 8. However, the cutting tool 100 of the present embodiment is a cutter body 101 in a state in which the cutter body 101, the cutting insert 201, and the cutting insert 201 (hereinafter referred to as an'insert') that form an annular shape are fixed. 101), and the like. Details of these will be described later, but the overall outline (see FIGS. 1 to 4) is a point symmetry of the two cutting inserts 201 when the cutting tool 100 is viewed from the front (FIG. 2) in this embodiment. It is of a structure provided in an arrangement, and in a predetermined position of the front surface 103 of the cutter body 101, a concave portion 105 for mounting the holder 301 is formed in a point-symmetrical arrangement, in which two holders ( 301) is mounted by bolting. Then, in each holder 301, a cutting insert 201 for thread cutting is protruded by a predetermined amount in the direction of the cutting depth of the workpiece (not shown) in the annular inner side of the cutter body 101. The cutting tool 100 is positioned to maintain a rotational center (O) and a constant dimension (K) (see FIG. 3). Hereinafter, these will be described in detail sequentially, and each part of the cutter body 101 has a point-symmetrical shape when viewed from the front (see FIG. 2), and two cutting inserts 201 and holders (main components) 301) are the same, and point-symmetrical arrangements are provided, so each one will be described.

First, the cutting insert 201 fixed in this embodiment is demonstrated (refer to FIGS. 3-6, etc.). The cutting insert 201 of the present embodiment is formed on the basis of a trapezoidal plate whose overall shape is a regular trapezoid and has a constant thickness, and the cutting edge 210 is the lower side (parallel 2 sides) of this trapezoid. The long side in Fig. 6A, the upper side in Fig. 6A and the inner angle (acute angle) of each angle are formed at each corner as a tool angle α. In other words, the cutting edge 210 is an inclined surface 213 of the area near each acute angle (corner) of the surface forming the lower side of the trapezoid with an acute angle therebetween, and the angle of the trapezoid between the acute angles (脚) two of the surfaces forming the acute angle (corner) near the front flank surface 215 are formed. In addition, in the present embodiment, since the cutting edge 210 is used for trapezoidal threading, the shape of the blade end 211 of the inclined surface 213 forms a trapezoidal convex shape corresponding to the screw bottom (bone shape) ( 5, 6, etc.). However, in the present embodiment, the cutting edge 210 has a thickness of an acute angle portion in a trapezoidal plate material, and an appropriate amount of an acute angle in an acutely inclined shape (isosceles triangle shape) on both sides (front and rear) 221 of the trapezoidal plate material. ), the cutting edge 210 is formed to protrude from the inclined cut surface (the surface facing the blade end 211) 223 by cutting (cutting) with ). As a result, the cutting insert 201 of this embodiment is comprised of the cutting edge 210 formed corresponding to this cut, and the relatively thick base 230 other than this. In addition, when the cut amount is viewed from the inclined surface 213 side (see Fig. 6-B), it is different on both sides 221 of the trapezoidal plate (base 230), and the cutting edge 210 is one-sided. It is supposed to be ubiquitous. However, the two cutting edges 210 are formed in a point-symmetrical arrangement so that the positions in the thickness (dimensions between both sides) of the base 230 are the same when the cutting edges 210 are fixed. In addition, the localization of the cutting edge 210 is to increase the machining accuracy by positioning the cutting edge 210 at a position as close as possible to the rotational support side of the workpiece during thread cutting.

The shape when viewed from the inclined surface 213 side of the cutting edge 210 in the cutting insert 201 of the present embodiment is a front cutting edge 210a and a thread parallel to the screw shaft that processes the screw bottom. Consists of both side cutting edges (210b) for processing the inclined surface, such a cutting insert 201 has an appropriate polishing value (T) for the inclined surface 213 and the inclined surface side 213b in the base 230 Is given. Further, even after the plane polishing, the trapezoidal convex cutting edge 210 of the inclined surface 213 in charge of cutting is formed so as not to affect the threading. That is, the front flank surface 215 is the direction away from the blade end 211 by the width of the front cutting edge 210a when new (unused) (bottom 240 of the cutting insert 201 (isometric of FIG. 6-A) The upper side in the trapezoid)}, and the inclination on the inclined surface 213 of the two side cutting edges 210b sandwiching the front cutting edge 210a between the side flanks is maintained to be constant even when the polishing proceeds. The side flank angle is not provided to the surface 216. However, depending on the required processing precision, a side flank angle of a small angle may be provided. In addition, the dimension at the time of new cutting of the cutting edge 210 in the cutting depth direction is set long in correspondence with the applied polishing value so that the required dimension is secured even after re-grinding on the inclined surface 213 side.

On the other hand, the inclined surface 213 of the cutting insert 201 and the inclined surface side surface 213b in the base 230 form one plane in this embodiment. In addition, when the front flank surface side surface 215b in the base 230 represents the tool angle α, the front flank surface 215 forming a tool angle α with a straight line drawn along the inclined surface 213 It is formed so as to contact the straight line drawn along the ). By this, in this embodiment, the front flank surface 215 and the front flank surface side surface 215b in the base 230 are formed so as to form one plane.

The cutting insert 201 of the present embodiment is a method of being fixed to a clamp portion in the holder 301 by screw fixing, and a hole through which a screw member (clamp screw 250) penetrates in the center of the base 230 (235) is formed. However, the holes 235 are formed on the spot facing surfaces 233 respectively formed on the both surfaces 221 in order to invert the other trapezoidal surfaces in the exchange of the two cutting edges 210. The hole 235 is an elongated hole extending vertically from the center of the lower side of the isosceles trapezoid, and has a wider hole near the upper side than the width of the lower side. This is the acute angle along the front flank surface 215 of the inclined surface 213 corresponding to the polishing value T in the acute angle direction (arrow H direction. See Fig. 9) when mounted on the holder 301 after re-polishing. This is because it is necessary to move in parallel so that the polishing value T can be largely secured without disturbing the screw fixing. In addition, the cutting insert 201 is not only screwed by the clamp screw 250, but is also pressed by the pressing mechanism 401 as described later in the vicinity of the bottom surface 240 of the cutting insert 201. have. Then, in order to counter the cutting main force and the distributing force in this pressing, a portion near the corner of the cutting edge 210 at the time of cutting and diagonally positioned. The inclined surface 243 is provided in a flat cut shape. Although this is intended to prevent displacement of the blade tip 211 position by this pressing force, this is not necessary when screwing by the clamp screw 250 is sufficient, such as machining with a small cutting resistance.

On the other hand, the cutter body 101 is provided with a bolt hole 104 in place so that its mounting surface (back) 110 is mounted to the spindle (rotating shaft) head SH of the machining machine by bolting, and the rotating shaft {Rotational center (O)} has an appropriate thickness in the direction, and has an outer circumferential surface having a through portion 120 through which a workpiece (shaft member) transferred to the center has a cylindrical shape (FIGS. 1 to 4, See Figure 7, etc.). In this cutter body 101, the front side (front 103 of the cutter body 101) which is the opposite side of the mounting surface 110 mounted on the front side of the spindle head SH. In the front view of FIG. 2, the concave portions 105 for fixing the holder 301, which are substantially rectangular in shape and have a certain depth when viewed from the front, are cut so as to open to the outer circumferential surface and the through portion 120, respectively, in a point-symmetrical arrangement. . The concave portion 105 has wall surfaces 107 and 108 which are placed upside down from the flat bottom surface 106 and arranged in parallel, and the holder described later to be sandwiched between both wall surfaces 107 and 108 ( 301) is placed on the bottom surface 106 in a seating shape, and is mounted by fastening the bolt with a holder fixing bolt 350 to two screw holes 109 formed on the bottom surface 106 (see FIG. 7 ). ).

That is, the holder 301 mounted on the recess 105 of the cutter body 101 is provided with slide surfaces 304 and 305 facing the wall surfaces 107 and 108 of the recess 105, and the cutter In order to adjust the position in the main body 101, the slide is moved in the direction of the outer peripheral surface and the penetrating portion 120 in the cutter body 101 along the wall surfaces 107 and 108 through the slide surfaces 304 and 305. It is possible. Further, a long hole 307 is formed in a portion located near the slide surfaces 304 and 305 of the holder 301, and the holder 301 is a screw member (holder fixing bolt 350) at a predetermined position. } Is fixed to the cutter body 101 by fitting the screw hole 109 as described above through the elongated hole 307 and adjusting the position thereof.

On the other hand, the holder 301 is substantially L-shaped when viewed from the front and has a block shape of a constant thickness, but is mounted while forming a height that does not protrude from the front (surface) 103 of the cutter body 101. And, the clamp portion 310 is concavely formed in the middle portion of the holder 301, and the cutting insert 201 having the above-described configuration is one of the trapezoidal plates on the bottom surface 313 of the clamp portion 310. It is fixed by seating and positioning the face 221 of the. That is, the clamp portion 310 is a wall surface of a form that is erected upward from the flat bottom surface 313, the inclined surface side surface 213b of the cutting insert 201 as the first constrained surface, and the front flank surface side In order to constrain each of the surfaces 215b as the second constrained surface, two constrained wall surfaces {ie, the first constrained wall surface 323 each forming a linear shape when viewed from the front and having the same angle as the tool angle α ) And the second constraining wall surface 325} are formed, and the cutting insert 201 has an inclined surface side (first constrained surface) on the first constraining wall surface 323 and the second constraining wall surface 325, respectively. 213b) and the front flank surface side (second confinement surface) 215b are fixed to be positioned. In this way, the cutting insert 201 protrudes an appropriate amount of the blade end 211 toward the center of the penetrating portion 120 of the cutter body 101 in the restrained state, and is given a proper degree of inclination angle and front flank angle. By achieving, the blade tip 211 is set so that the predetermined dimension K is maintained from the rotation center O.

In addition, the cutting insert 201 inserts the clamp screw 250 into the hole (long hole) 235 formed in the base 230, and then the bottom surface 313 of the clamp portion 310 of the holder 301 It is fixed by screwing in the screw hole 315 formed in the. In addition, in the present embodiment, in order to fix the cutting insert 201, a portion near the bottom surface 240 of the cutting insert 201 is pressed with the pressing mechanism 401 as described above. As shown in FIG. 8 and the like, the pressing mechanism 401 is inserted in a slide shape at a portion on the bottom 240 side of the cutting insert 201 in the holder 301, and the cutting insert 201 is inclined (213). ) It is set to fix the pressure by pressing the bolt with the bolt 450 for fixing the pressure mechanism in the pushed up state. Then, in order to counter the cutting main force and the distributing force, the pressing surface presses the inclined surface 243 of a flat cut shape formed at a corner near the corner of the cutting edge 210 at the time of cutting. In addition, a screw hole 415 for screwing the bolt 450 for fixing the pressing mechanism is formed on the bottom surface 313 of the clamp portion 310 of the holder 301, and the hole formed in the pressing mechanism 401 ( After inserting the pressing mechanism fixing bolt 450 into 410, this is fixed by screwing it into the screw hole 415. However, the hole 410 formed in the pressing mechanism 401 is a long hole corresponding to the polishing of the inclined surface 213 and the inclined surface side surface 213b, that is, in response to a change in the pressing position.

Then, the cutting insert 201 is disposed on the clamp portion 310 of the holder 301 temporarily fixed to the cutter body 101 mounted on the spindle head SH of the processing machine, but the surface 213b of the inclined surface side is disposed. The first restraint surface is restrained on the first restraining wall surface 323, the front flank surface side surface 215b is restrained on the second restraining wall surface 325 as the second restraint surface, and the cutting insert is as described above. Screw (201). Then, as described above, the cutting insert 201 is fixed to the holder 301 by bolting the pressing mechanism 401 to the holder 301. In addition, the position of the desired blade tip 211 corresponding to the screw diameter and the thread height of the shaft member, where the blade tip 211 in the cutting insert 201 is a work piece (dimension (K) from the rotation center O )}, the position of the holder 301 relative to the cutter body 101 is adjusted within the range of the long hole 307 of the holder 301, and then the holder fixing bolt 350 is fastened. With the cutting tool 100 shown in Figs. 1 and 2 thus obtained, thread whirling can be performed thereafter.

Then, when the cutting edge 210 in the cutting insert 201 at the time of a new product is reduced in this machining step due to wear or the like, the cutting edge 201 is stopped once, and the cutting insert 201 is held in the holder 301 ), the cutting edge 210 is exchanged as described above to cut with the cutting edge 210 of an unused corner, and processing continues. Thereafter, when the sharpness of the blade ends of both cutting edges 210 decreases, the cutting insert 201 is removed from the holder 301, and the inclined surface side surface 213b in the inclined surface 213 and the base 230 ) Is polished by a proper amount of the same abrasive value so that damage parts such as wear or chipping of the blade end 211 of both cutting edges 210 are removed. Thereby, simultaneous reproduction of both cutting edges 210 is performed. Then, by fixing this so as to be positioned in the clamp portion 310 of the holder 301 as described above, so that either cutting edge 210 in this cutting insert 201 is used for thread cutting. , You can resume threading to continue.

At this time, the cutting insert 201 after this planar polishing (re-polishing) is shown in Fig. 9B as compared to a new product as shown in Fig. 9A, the inclined surface 213b including the inclined surface 213 and the first constrained surface. As shown, it is as low as the polishing value T, but the cutting insert 201 after the polishing is to be positioned in the protruding direction of the blade end 211 as before polishing, and the clamp screw ( By fixing the screws by fixing the screws 250 and fastening the holder fixing bolts 350 of the pressing mechanism 401, the position of the blade end 211 becomes the original position and fixed regardless of the polishing. Thereby, machining can be resumed as it is without the need for the adjustment operation of the positioning of the blade end 211 as in the prior art.

That is, in this fixation, the cutting insert 201 after polishing follows the second restraining wall surface 325 of the clamp portion in the state before polishing, and also uses this as a guide to slide the second constrained surface in the direction of the arrow H. 1 Since the surface to be constrained only moves parallel to the polishing value until it comes into contact with the first restraining wall surface 323, displacement does not occur at the position of the blade end 211. As a result, the thread whirling process is possible because the blade end 211 can be simply and quickly returned to the correct blade end position without requiring adjustment of the position in the positioning for fixing each re-grinding as in the prior art. Can proceed efficiently. In addition, in this embodiment, the inclined surface 213 and the inclined surface side 213b of the base 230 are made into one plane, but it is clear that a part of the inclined surface side surface 213b may be partially recessed, for example. Do.

In the present embodiment, since the cutting insert 201 is embodied as an equilateral trapezoidal plate shape as described above, two cutting edges 210 can be provided, and these two cutting operations are performed by one re-grinding process. It is possible to reduce the cost of the cutting insert 201 along with polishing, such as the blade 210 being regenerated. In addition, in polishing, since the inclined surface (bottom side of trapezoid) 213 and the bottom surface (top side of trapezoid) 240 opposite to the inclined surface 213, the plane is easily polished by using this bottom surface as a reference surface. You can also get the effect that it may.

Moreover, the cutting insert 201 of this embodiment makes the hole for screw fixation by the clamp screw 250 a long hole extended in the straight line drawn perpendicularly from the center of the lower side in an isosceles trapezoid, and the bottom It is a long hole with a wider width on the side near the upper side than the width on the side near the side. For this reason, by setting the outer diameter of the head of the clamp screw 250 to be large, it is possible to efficiently press the cutting insert even when the polishing value T becomes large.

In addition, in the present embodiment, the front flank surface 215 of the cutting insert 201 and the front flank surface side surface 215b of the base 230 are formed to form one plane, but in the present invention, the inclined surface and In the cutting insert after polishing the inclined surface at the base, along the second restraining wall surface of the clamp portion in the state before polishing, and also using this as a guide, slide the second constrained surface (front flank surface). 1 When the surface to be constrained (surface on the inclined surface) moves parallel to the polishing value until it abuts on the first restraining wall surface of the clamping portion, displacement does not have to occur at the blade end position. Therefore, the front flank surface 215 and the front flank surface side surface 215b of the base 230 may not be formed as one plane, for example, as shown in the cutting insert 501 shown in FIG. 10. . That is, as shown in FIG. 10A, the front flank surface side surface 215b in the base 230 does not form a plane with the front flank surface 215, but the front flank surface side surface in this base 230 When 215b) is parallel to a straight line drawn along the front flank surface 215 when the tool angle α is formed so as to form the same angle as the front flank angle, it is displaced at the blade end 211 position as shown in FIG. 10B even after repolishing. Because it does not cause anything.

In the present embodiment, the case where a cutting insert for trapezoidal threading is used has been described, but the cutting edge shape of the cutting insert may be set to be appropriate according to the shape of the thread to be machined. In the case of a thing, it is good to make it the blade shape required for this. In addition, the object of the "thread whirling process" in the present invention is not limited to a typical screw member such as a threaded part that is screwed while allowing the other member to cut a screw such as a bolt or a tapping screw. , The machining of a shaft member having a certain acid (screw thread) that is raised by a certain spiral on the outer circumferential surface is also included, such as processing of a screw structural member such as one worm (worm shaft) constituting a worm gear.

In addition, the holder presses the first constrained surface to the first constraining wall surface and the second constrained surface to the second constraining wall surface, respectively, to position the cutting edge in the protruding direction when the cutting insert is fixed to the clamp portion. As long as it can be in charge, it can be embodied as having an appropriate shape and structure. Further, in the present embodiment, since the position of the blade end of the new cutting insert is determined by adjusting the position of the holder mounted on the cutter body, it is possible to respond widely to changes in the outer diameter and thread height of the shaft member to be processed. However, in the present invention, when a dedicated product is used in at least one of the cutter body or the cutting insert so that the cutting edge can be positioned by fixing the new cutting insert to the clamp portion in the cutter body, this embodiment is performed. No holder as in the form is required. That is, although the clamp portion in the cutter body cannot be called a holder, if the blade end of the cutting insert can be positioned at a desired position and configured to be fixed, it can be specified without the need for a separate holder. Can be. As described above, the present invention is not limited to the specific embodiments described above, and can be embodied by appropriately changing the scope without departing from the gist thereof.

In addition, in each of the above-described embodiments, the cutting insert is embodied in constituting the cutting tool for thread whirling, but as described above, the cutting insert of the present invention is not limited to constituting the cutting tool for thread whirling. It can also be applied as a component of a cutting tool (byte) used for normal threading by a lathe or a cutting tool used for processing other than this.

100: cutting tool for thread whirling
101: cutter body
201, 501: cutting insert
210: cutting edge
211: end of the day
213: slope
213b: Slope side surface at base
215: front flank surface
215b: front flank face side surface at base
230: base for fixing to the clamp portion of the cutting insert
301: holder
310: clamp part
323: first restraint wall surface of the clamp portion
325: second restraint wall surface of the clamp portion
T: Polishing value
α: Tool angle

Claims (10)

Cutter body forming an annular shape, and And a cutting insert fixed to a clamp portion in a clamp portion or a holder mounted so that the mounting position is adjustable on the cutter body, and the cutting edge of the cutting edge is a work piece in an annular inner side of the cutter body. A cutting tool for thread whirling that is positioned by protruding a predetermined amount in the cutting depth direction of
The cutting insert has a cutting edge and a base for fixing to the clamp portion, and a tool angle, which is an intersection angle between the inclined surface and the front flank surface constituting the cutting edge, forms an acute angle, and the inclined surface And the surface of the inclined surface at the base is brought into contact with a virtual one plane, and also has a predetermined polishing value for repolishing.
When the front flank surface side surface in the base indicates the tool angle, the intersection of the straight line and the inclined surface along the front flank surface side surface is formed to be the same as the angle of the tool angle,
The clamp portion has a first restraining wall surface that restrains the inclined surface side as a first constrained surface, and a second restraining wall surface that constrains the front flank surface side as a second constrained surface,
Positioning the protruding direction of the blade tip in fixing the cutting insert with respect to the clamp portion, the first constrained surface on the first constraining wall surface, and the second constrained surface on the second constraining wall surface, respectively. A cutting tool for thread whirling, characterized by being in charge by pressing.
The method according to claim 1,
A cutting tool for thread whirling, characterized in that the inclined surface of the cutting insert and the inclined surface side of the base form one plane.
The method according to claim 1,
A cutting tool for thread whirling, characterized in that the front flank surface of the cutting insert and the front flank surface at the base form one plane.
The method according to claim 2,
A cutting tool for thread whirling, characterized in that the front flank surface of the cutting insert and the front flank surface at the base form one plane.
The method according to any one of claims 1 to 4,
The cutting insert is formed in a plate shape of an isosceles trapezoid, and the inside angle of the bottom side and each angle in the isosceles trapezoid is a tool angle, and the structure has a sloped surface at both ends of the bottom side. Cutting tool for thread whirling, characterized in that it has two identical cutting edges.
A cutting insert having a base for fixing to a cutting edge and a clamp portion,
A tool angle that is an acute angle between the inclined surface and the front flank surface constituting the cutting edge forms an acute angle, and the inclined surface and the surface of the inclined surface in the base contact the virtual one plane, and is further polished for repolishing. In addition to having a value,
When the front flank surface side surface in the base indicates the tool angle, the intersection of the straight line and the inclined surface along the front flank surface side surface is formed to be the same as the angle of the tool angle,
The cutting insert, characterized in that the inclined surface side surface and the front flank surface side surface are formed as forming a constrained surface in fixing to the clamp portion.
The method according to claim 6,
The cutting insert, characterized in that the inclined surface of the cutting insert and the inclined surface side surface in the base form one plane.
The method according to claim 6,
The cutting insert, characterized in that the front flank surface of the cutting insert and the front flank surface side of the base form a plane.
The method according to claim 7,
The cutting insert, characterized in that the front flank surface of the cutting insert and the front flank surface side of the base form a plane.
The method according to any one of claims 6 to 9,
The cutting insert is formed in a plate shape of an isosceles trapezoid, and the inside angle of the bottom side and each angle in the isosceles trapezoid is a tool angle, and the structure has a sloped surface at both ends of the bottom side. A cutting insert, characterized in that it has two identical cutting edges.

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