JP2021102236A - Cutter clamp mechanism and manufacturing method of cutter body including cutter clamp mechanism - Google Patents

Abstract

To attach a cutter body to an arbor with high attachment rigidity.SOLUTION: In a cutter clamp mechanism, a cylindrical cutter body 1 rotated around an axis line O is fastened and attached to an arbor by a clamp bolt 5. A cutting blade is provided on an outer circumference of a tip end portion of the cutter body 1. On an inner circumferential portion of the cutter body 1, a through hole 6 which is opened in a rear end portion of the cutter body 1 and through which a screw portion 5a of the clamp bolt 5 is inserted, an accommodation hole 7 that communicates with a tip end side of the through hole 6, accommodates a head portion 5b of the clamp bolt 5, and has an inner diameter larger than that of the through hole 6, and an insertion hole 8 communicating with a further tip end side of the accommodation hole 7, opened in the tip end portion of the cutter body 1, and through which a work tool configured to engage with an engagement portion 5c formed on a tip end surface of the clamp bolt 5 is inserted are formed along the axis line O. An inner diameter of the opening portion of the insertion hole 8 in the tip end portion of the cutter body 1 is smaller than an outer diameter of the head portion 5b of the clamp bolt 5.SELECTED DRAWING: Figure 2

Description

The present invention includes a cutter clamp mechanism for attaching a cylindrical cutter body having a cutting edge on the outer periphery of the tip portion and rotating around the axis by fastening it to an arbor with a clamp bolt, and such a cutter clamp mechanism. It relates to a method of manufacturing a cutter body.

As such a cutter clamp mechanism, the head of the clamp bolt is formed by screwing the screw portion of the clamp bolt inserted from the tip side into the inner peripheral portion of the cylindrical cutter body into the screw hole formed on the tip surface of the arbor. Conventionally, it has been generally known that a portion presses the tip surface of a cutter body to fasten it to an arbor.

By the way, in such a general cutter clamp mechanism, a counterbore is formed on the tip side of the inner peripheral portion of the cutter body so that the head of the clamp bolt does not protrude toward the tip side of the cutting edge. .. However, when the outer diameter of the cutting edge of the cutter body becomes smaller, for example, in the case of a cutter with a replaceable cutting edge, the wall surface of the insert mounting seat where the cutting insert is attached and the inner peripheral surface of the counterbore hole The wall thickness between them cannot be secured, and the cutting insert may interfere with the clamp bolt.

Therefore, for example, Patent Document 1 includes a cutter body that is fitted with the axis (axis) aligned with the tip of the tool mounting shaft (arbor), and a screw rod that fixes the cutter body to the tool mounting shaft. A male screw that is screwed into a screw hole provided on the tip surface of the tool mounting shaft is formed on one end side of this screw rod, and a male screw that is opposite to the one end side is formed on the other end side. The cutter main body describes a cutter clamp mechanism in which a screw hole is formed to be screwed into a male screw on the other end side of a screw rod.

Further, also in Patent Document 2, a cutting insert is detachably attached to a chip pocket provided on the outer peripheral portion on the tip side in the axial direction of the tool body (cutter body) rotated around the axis (axis). In the clamp mechanism of a cutting tool (cutter) with a replaceable cutting edge, where the rear end side of the tool body in the axial direction is attached to the arbor with a mounting bolt (clamp bolt), a mounting bolt with a tightening hole on the bolt head is used. , A guide accommodating hole for guiding and accommodating the bolt head of the mounting bolt from the axial rear end side of the tool body is provided at the center of the tool body on the axial rear end side, and is accommodated in the guide accommodating hole. Described is provided with a holding means for holding the mounted mounting bolt in the guide accommodating hole in a rotatable state.

Further, in the cutter clamp mechanism described in Patent Document 2, a tightening hole having a diameter smaller than that of the bolt head of the mounting bolt is provided so as to penetrate the guide accommodating hole from the axial tip side of the tool body. When holding the mounting bolt in the guide accommodating hole by the holding means, an insertion hole is provided in the center of the clamp member whose flat surface is non-circular to be placed on the bolt head of the mounting bolt accommodated in the guide accommodating hole. It is provided.

Then, in the cutter clamp mechanism described in Patent Document 2, the bolt shaft of the mounting bolt is inserted into the insertion hole to accommodate the non-circular clamp member in the guide accommodating hole, and the clamp member is rotated. The clamp member is locked in the locking portion provided in the guide accommodating hole, and the rotation suppressing member for suppressing the rotation of the clamp member locked in the locking portion is accommodated in the guiding accommodating hole. , This rotation restraining member is fixed in the guide accommodating hole by a screw member.

Japanese Unexamined Patent Publication No. 5-237716 Japanese Patent No. 5307619

However, in the cutter clamp mechanism described in Patent Document 1, as shown in FIG. 1 of Patent Document 1, the male screw on one end side and the male screw on the other end side of the screw rod are thin with substantially the same diameter and have screw holes. Since the screwing position is close to the axis, there is a problem that the screw rod is liable to loosen.

On the other hand, in the cutter clamp mechanism described in Patent Document 2, many parts are required to clamp the cutter body, and the management of parts becomes complicated and easily lost. In addition, since the clamp member and the rotation restraining member are accommodated in the guide accommodating hole of the cutter body, the wall thickness of the cutter body may be greatly reduced by the guide accommodating hole, and the rigidity of the cutter body may decrease. There is also.

Further, since the screw member for fixing the rotation restraining member is screwed in the radial direction with respect to the axis of the cutter body, the screw member may scatter when the cutter body is rotated at high speed. Furthermore, in the cutter clamp mechanism described in Patent Document 2, a refrigerant supply hole (coolant hole) is formed in the cutter body, but when the refrigerant supply hole interferes with the mounting screw hole into which the screw member is screwed, , Coolant leakage may occur.

The present invention has been made under such a background, and it is possible to reduce the number of parts for clamping the cutter body, secure the rigidity of the cutter body, and cause scattering of screw members and leakage of coolant. It is an object of the present invention to provide a cutter clamp mechanism capable of mounting a cutter body on an arbor with high mounting rigidity, and a method for manufacturing a cutter body provided with the cutter clamp mechanism.

In order to solve the above problems and achieve such an object, the cutter clamp mechanism of the present invention is a cutter clamp mechanism that clamps and attaches a cylindrical cutter body that is rotated around an axis to an arbor with a clamp bolt. A cutting edge is provided on the outer periphery of the tip portion of the cutter body, and a screw portion of the clamp bolt is inserted into the inner peripheral portion of the cutter body by opening at the rear end portion of the cutter body. The through hole is communicated with the tip side of the through hole to accommodate the head of the clamp bolt, and the accommodating hole having an inner diameter larger than that of the through hole is communicated with the tip side of the accommodating hole. An insertion hole that opens at the tip of the cutter body and is formed on the tip surface of the clamp bolt and into which a work tool that engages is inserted is formed along the axis of the cutter. The inner diameter of the opening of the insertion hole at the tip of the main body is smaller than the outer diameter of the head of the clamp bolt.

Further, the method for manufacturing the cutter body of the present invention is a method for manufacturing the cutter body provided with such a cutter clamp mechanism, and the rear end portion of the cutter body is formed in the axial direction by laminating using a 3D printer. In the radial direction of the insertion hole with respect to the axis at the height of the head of the clamp bolt or more from the plane perpendicular to the axis at the position of the bottom surface of the tip of the cutter body facing the tip side in the accommodation hole. After forming a portion within the range up to the position where the head can be inserted, and then smoothing the plane to form a bottom surface facing the tip side in the accommodating hole, the clamp bolt is described above. It is characterized in that the screw portion is inserted into the through hole, the rear end surface of the head is brought into contact with the bottom surface, and the entire cutter body is formed by laminating using a 3D printer.

In the cutter clamp mechanism having the above configuration, the only part required to clamp the cutter body to the arbor is the clamp bolt, and this clamp bolt has a through hole whose head has a diameter smaller than the accommodating hole and the cutter body. Since it is sandwiched between the opening of the insertion hole having an inner diameter smaller than the outer diameter of the head opening at the tip of the cutter, it does not come off from the cutter body. For this reason, parts management is facilitated, and the clamp bolt is not lost or the screw member is not scattered.

In addition, the holes formed in the cutter body for the clamp need only be through holes, accommodating holes, and insertion holes, so that the rigidity of the cutter body can be ensured and the cutter body is the head of the clamp bolt away from the axis. Since it is pressed by the arbor and attached to the arbor, the mounting rigidity can be improved and the processing accuracy can be improved. Further, since it is not necessary to form a mounting screw hole for screwing the screw member, even if a coolant hole for supplying coolant to the cutting edge is formed, coolant leakage does not occur due to interference with the mounting screw hole. ..

As in the cutter clamp mechanism described in Patent Document 2, if a tightening hole having a diameter smaller than the head of the clamp bolt is opened at the tip of the cutter body with a constant inner diameter, it is used for tightening. Chips and debris that have entered the hole may become clogged and accumulated in the tightening hole.

Therefore, the inner peripheral surface of the insertion hole is formed so that at least the accommodating hole side gradually shrinks in diameter toward the tip end side of the cutter body, so that the inner peripheral surface of the insertion hole is along the inner peripheral surface of the reduced diameter insertion hole. Chips and dust can be discharged to the tip side of the cutter body so as to be guided, and the accumulation of such chips and dust can be prevented.

Further, in the method for manufacturing the cutter body of the present invention, the rear end portion of the cutter body and the bottom surface of the tip end portion of the cutter body facing the tip end side in the accommodating hole are formed by laminating using a 3D printer. A portion within the range from the plane perpendicular to the axis of the position to the position where the head can be inserted in the radial direction with respect to the axis in the insertion hole at the height of the head of the clamp bolt or more is formed. Next, after smoothing the flat surface to form a bottom surface facing the tip end side of the accommodating hole, the screw portion of the clamp bolt is inserted into the through hole to bring the rear end surface of the head into contact with the flat surface. Therefore, it is possible to improve the degree of adhesion between the rear end surface of the head and the plane which is the bottom surface facing the tip end side in the axial direction of the accommodating hole.

For this reason, in a cutter body manufactured entirely by laminating, when the clamp bolt is used to clamp the tip of the arbor, the rear end surface of the head of the clamp bolt faces the tip side in the axial direction of the accommodating hole. Since the bottom surface can be pressed uniformly, the cutter body can be attached to the arbor with even higher mounting rigidity. Therefore, the processing accuracy can be further improved.

The surface roughness of the flat surface of the bottom surface that has been smoothed in this way is preferably in the range of 1.6 μm to 12.5 μm at the maximum height roughness Rz in JIS B 0601: 2013. .. If the maximum height roughness Rz exceeds 12.5 μm, the degree of adhesion between the rear end surface of the head of the clamp bolt and the bottom surface of the accommodating hole cannot be sufficiently increased, and the above-mentioned effect cannot be obtained. There is a risk. On the other hand, it is difficult to smooth the flat surface as the bottom surface so that the maximum height roughness Rz is less than 1.6 μm, which requires a lot of time and labor.

As described above, according to the present invention, the number of parts for clamping the cutter body can be suppressed to facilitate parts management and prevent loss, and also to cause scattering of screw members and leakage of coolant. Absent. Furthermore, the rigidity of the cutter body can be ensured by reducing the number of holes formed in the cutter body for the clamp, and the cutter body can be mounted on the arbor with high mounting rigidity to improve machining accuracy. It becomes possible.

It is a perspective view of the cutter body which shows one Embodiment of this invention. FIG. 5 is a cross-sectional view taken along the axis of the embodiment shown in FIG. It is a side view of the cutter body of the embodiment shown in FIG. It is a bottom view seen from the tip side in the axial direction of the cutter body of the embodiment shown in FIG. FIG. 5 is a plan view of the cutter body of the embodiment shown in FIG. 1 as viewed from the rear end side in the axial direction. It is sectional drawing (ZZ sectional view in FIG. 3) along the axis of the cutter body of the embodiment shown in FIG. It is sectional drawing along the axis which shows the 1st process in one Embodiment of the manufacturing method of the cutter body of this invention. It is sectional drawing along the axis which shows the 2nd step in one Embodiment of the manufacturing method of the cutter body of this invention. It is sectional drawing along the axis which shows the 3rd process in one Embodiment of the manufacturing method of the cutter body of this invention. It is sectional drawing along the axis which shows the 4th process in one Embodiment of the manufacturing method of the cutter body of this invention. It is sectional drawing along the axis which shows the 5th step in one Embodiment of the manufacturing method of the cutter body of this invention.

1 and 2 show an embodiment of the cutter clamp mechanism of the present invention, and FIGS. 3 to 6 show a cutter body 1 (clamp bolt) of the cutter clamp mechanism shown in FIGS. 1 and 2. (Excluded) is shown. Further, FIGS. 7 to 11 show an embodiment of the method for manufacturing a cutter body of the present invention.

In the present embodiment, the cutter body 1 attached to the tip of an arbor (not shown) is integrally molded into a cylindrical shape centered on the axis O by a metal material such as a steel material. Here, in the cutter of the present embodiment, the cutting edge 3a is formed on the insert mounting seat 2 formed on the outer periphery of the tip portion (lower portion in FIGS. 2, 3 and 5) of the cutter body 1. This is a cutter with a replaceable cutting edge to which the insert 3 can be attached and detached.

In such a cutter, the rear end portion (upper portion in FIGS. 2, 3 and 5) is attached to the arbor, and is attached to the spindle of the machine tool via the arbor, and the cutter rotation direction T around the axis O. It is sent out in a direction intersecting the axis O while being rotated to, and the work material is cut by the cutting edge 3a of the cutting insert 3.

At the rear end of the cutter body 1, a key groove 1a formed at the tip of the arbor into which a key (not shown) is fitted is formed so as to extend in the radial direction with respect to the axis O. Further, a plurality of recessed groove-shaped tip pockets 1b extending in the axial direction O direction are formed on the outer periphery of the tip portion of the cutter body 1 at intervals in the circumferential direction (four at equal intervals in this embodiment). The insert mounting seat 2 is formed in a concave shape at the tip of the wall surface of these tip pockets 1b facing the cutter rotation direction T.

The cutting insert 3 attached to these insert mounting seats 2 is formed in a substantially hexagonal shape in the present embodiment by a metal material having a hardness higher than that of the cutter body 1 such as cemented carbide, and has a hexagonal shape on the front and back sides. The cutting edge 3a is formed on each side ridge of the surface. Further, a mounting hole 3b that penetrates the cutting insert 3 is opened in the central portion of the front and back uneven hexagonal surfaces of the cutting insert 3.

Such a cutting insert 3 faces the bottom surface 2a of the insert mounting seat 2 in the cutter rotation direction T with one polarized hexagonal surface as a rake face and the other polarized hexagonal surface as a seating surface. The side surface of the cutter body 1 facing the tip end side and the side surface facing the inner peripheral side are brought into close contact with the wall surface 2b facing the tip end side and the wall surface 2c facing the outer peripheral side of the insert mounting seat 2 and seated on the insert mounting seat 2. Be made to.

Further, a screw hole 2d is formed on the bottom surface 2a of the insert mounting seat 2, and the mounting screw 4 inserted into the mounting hole 3b is screwed into the screw hole 2d so that the cutting insert 3 becomes the insert mounting seat 2. It is fixed and can be attached and detached. In the cutting insert 3 attached to the insert mounting seat 2 in this way, the cutting edge 3a directed toward the outer peripheral side of the tip of the cutter body 1 is exclusively used for cutting.

Further, in the inner peripheral portion of the cylindrical cutter main body 1, a through hole 6 is opened at the rear end portion of the cutter main body 1 and a screw portion 5a of the clamp bolt 5 is inserted as shown in FIG. A storage hole 7 having an inner diameter larger than that of the through hole 6 in which the head portion 5b of the clamp bolt 5 is accommodated by communicating with the tip side of the hole 6 and a storage hole 7 communicating with the tip side of the accommodation hole 7 to accommodate the cutter body 1. An insertion hole 8 is formed along the axis O, which is opened at the tip portion and into which a work tool for engaging with the engaging portion 5c formed on the tip surface of the head portion 5b of the clamp bolt 5 is inserted. ..

Further, in the rear end portion of the cutter body 1, a columnar convex portion formed in the central portion of the tip surface of the arbor is fitted by opening to the rear end surface of the cutter body 1 and communicating with the key groove 1a. A fitting hole 1c having a diameter larger than that of the accommodating hole 7 is formed. A screw hole into which the screw portion 5a of the clamp bolt 5 can be screwed is formed in the central portion of the tip surface of the convex portion.

The central portion of the fitting hole 1c in the axis O direction is formed on a cylindrical surface having a constant inner diameter slightly smaller than both ends, and the key of the arbor is fitted into the key groove 1a. The tip of the convex portion is fitted into this cylindrical surface. With the convex portion fitted in this way, a gap is provided between the tip surface of the convex portion and the bottom surface of the fitting hole 1c that faces the rear end side in the axis O direction and is perpendicular to the axis O.

Further, at the intersecting ridge line portion between the bottom surface and the inner peripheral surface of the fitting hole 1c, the same number of coolant holes 1d as the chip pockets 1b are formed at equal intervals in the circumferential direction, and these coolant holes 1d are cutting inserts. The tip pocket 1b is opened on the wall surface facing the outer peripheral side of the tip so as to extend toward the cutting edge 3a used for cutting 3. The inner peripheral surfaces of the through hole 6, the accommodating hole 7, the insertion hole 8 and the fitting hole 1c are all formed in a circular shape having a cross section perpendicular to the axis O centered on the axis O.

The through hole 6 is open to the bottom surface of the fitting hole 1c at the rear end of the cutter body 1. Here, the through hole 6 has a constant inner diameter that is slightly larger than the outer diameter of the threaded portion 5a of the clamp bolt 5 and smaller than the outer diameter of the head portion 5b.

Further, the inner diameter of the accommodating hole 7 is also set to a constant size slightly larger than the head 5b of the clamp bolt 5, and the depth of the accommodating hole 7 in the axis O direction is set to a size capable of accommodating the head 5b. Therefore, in the present embodiment, the thickness of the head 5b in the axis O direction is substantially equal to that of the head 5b. Further, the engaging portion 5c formed on the tip surface of the head portion 5b of the clamp bolt 5 is a hole having a regular hexagonal cross section that engages with a shaft-shaped hexagon wrench in the present embodiment.

The inner diameter of the opening of the insertion hole 8 at the tip of the cutter body 1 is formed to be smaller than the outer diameter of the head portion 5b of the clamp bolt 5. Here, in the present embodiment, the inner peripheral surface of the insertion hole 8 accommodates the opening of the tip portion by gradually reducing the diameter of at least the portion on the accommodating hole 7 side toward the tip end side of the cutter body 1. It is formed so as to be smaller than the outer diameter of the head portion 5b of the clamp bolt 5 housed in the hole 7.

Specifically, as shown in FIGS. 2 and 3, the insertion hole 8 is gradually reduced in diameter with a constant taper angle with respect to the axis O as the accommodating hole 7 side of the inner peripheral surface thereof is directed toward the tip side, and the head portion 5b After becoming smaller than the outer diameter of the cutter body 1, it is formed so as to extend and open with a constant inner diameter on the tip end side of the cutter body 1.

The portion of the tip of the insertion hole 8 extending at a constant inner diameter has an inner diameter through which the work tool can be inserted, that is, the diameter of the circle circumscribing the hole having a regular hexagonal cross section formed by the engaging portion 5c. It has been slightly enlarged. Further, as shown in FIG. 2, the length of the screw portion 5a of the clamp bolt 5 in the axis O direction is such that the rear end surface 5d of the head portion 5b facing the rear end side in the axis O direction is the tip side of the accommodating hole 7 in the axis O direction. It has a length that slightly protrudes from the rear end surface of the cutter body 1 in a state of being in close contact with the facing bottom surface 7a.

The cutter body 1 having the clamp bolt 5 built therein is the raw metal of the cutter body 1 using a 3D printer, for example, as in one embodiment of the method for manufacturing the cutter body of the present invention shown in FIGS. 7 to 11. The prototype of the cutter body 1 is partially formed by laminating while melting the powder material of the above, the clamp bolt 5 is installed, and the entire prototype of the cutter body 1 is further formed by laminating, and then the screw hole 2d It can be manufactured by forming the insert mounting seat 2 and the like including the above by machining.

In the manufacturing method of the present embodiment, the cutter main body 1 is manufactured by laminating while melting the powder material of the raw material metal from the rear end portion upward toward the tip portion. In the first step of the present embodiment shown in FIG. 7, first, the rear end portion of the cutter body 1 and the tip end side of the cutter body 1 in the accommodating hole 7 among the tip portions of the cutter body 1 in the axis O direction (FIGS. 7 to 7). The head 5b can be inserted in the radial direction with respect to the axis O in the insertion hole 8 at a height equal to or higher than the head 5b of the clamp bolt 5 from the plane P perpendicular to the axis O up to the position of the bottom surface 7a facing the upper side in FIG. (In FIG. 7, a portion from the plane P to the height of the head portion 5b of the clamp bolt 5 in the axial direction O direction is substantially formed).

Next, as shown in FIG. 8, in the second step, the flat surface P is subjected to a smoothing treatment to reduce the surface roughness of the flat surface P and form the bottom surface 7a. As shown in FIG. 8, this smoothing process may be an end face cutting process using a face milling cutter or a cutting edge E of a cutting tool, or may be a grinding process using a grinding wheel. Further, it is desirable that the surface roughness of the bottom surface 7a formed by this smoothing treatment is within the range of 1.6 μm to 12.5 μm in the maximum height roughness Rz in JIS B 0601: 2013.

When the flat surface P is smoothed and the bottom surface 7a is formed in this way, the threaded portion 5a of the clamp bolt 5 is inserted into the through hole 6 and the axis O direction of the head portion 5b is formed as in the third step shown in FIG. The clamp bolt 5 is installed by bringing the rear end surface 5d facing the rear end side into close contact with the bottom surface 7a. Next, as in the fourth step shown in FIG. 10, the powder material of the raw material metal is melted and laminated so that the insertion hole 8 is formed on the tip end side of the head portion 5b of the clamp bolt 5. As in the fifth step shown in FIG. 11, the entire prototype up to the tip of the cutter body 1 is formed.

In the cutter body 1 in which the entire prototype is formed in this way, the insert mounting seat 2 including the screw hole 2d is molded to a predetermined accuracy by machining with a machining center or the like in the final process, and further, surface treatment or the like is performed as necessary. It is manufactured in the cutter body 1 in which the clamp bolt 5 is built, after being subjected to post-treatment or painting by plating or the like.

In order to attach the cutter body 1 manufactured in this way to the arbor, the phase of the key groove 1a at the rear end of the cutter body 1 in the circumferential direction is matched with the key of the arbor, and the fitting hole 1c is centered on the tip surface of the arbor. The cutter body 1 is arranged at the tip of the arbor in accordance with the position of the cylindrical convex portion of the portion.

Then, the working tool inserted through the insertion hole 8 is engaged with the engaging portion 5c of the head portion 5b of the clamp bolt 5 to rotate the clamp bolt 5, so that the screw portion 5a is the tip surface of the convex portion of the arbor. While being screwed into the screw hole formed in the central portion, the rear end surface 5d of the head portion 5b presses the bottom surface 7a of the accommodating hole 7, the cutter body 1 moves to the rear end side, and the key is fitted into the key groove 1a. At the same time, the convex portion is fitted into the fitting hole 1c, and the cutter body 1 is attached to the tip end portion of the arbor.

When cutting is performed by the cutter body 1 attached in this way, coolant is discharged from the machine tool through the arbor in the gap between the tip surface of the convex portion of the arbor and the bottom surface of the fitting hole 1c. It is supplied and ejected through the coolant hole 1d to the cutting edge 3a used for cutting.

In the cutter clamp mechanism configured as described above, the cutter body 1 is prevented from rotating by fitting the key groove 1a and the arbor key without forming the fitting hole 1c, and the rear end surface of the cutter body 1 and the arbor are prevented from rotating. Since the cutter body 1 may be attached by surface contact with the tip surface of the cutter body, the holes formed in the cutter body 1 for clamping need only be the through hole 6, the accommodating hole 7, and the insertion hole 8. The rigidity of 1 can be secured. Further, since the cutter body 1 is pressed by the rear end surface 5d of the head portion 5b of the clamp bolt 5 away from the axis O and attached to the arbor, the attachment rigidity can be improved.

Moreover, even with a cutter having a replaceable cutting edge like the cutter of the present embodiment, the opening at the tip of the cutter body 1 of the insertion hole 8 has a smaller diameter than the head 5b of the clamp bolt 5, so that the cutting blade 3a Even if the outer diameter (the diameter of the circle formed by the outer peripheral end of the cutting edge 3a used for cutting around the axis O) becomes smaller, between the wall surface 2c facing the outer peripheral side of the insert mounting seat 2 and the insertion hole 8. The wall thickness can be secured, and the mounting strength of the cutting insert 3 can be improved. Therefore, it is possible to perform cutting with high machining accuracy.

Further, the only component required to clamp the cutter body 1 to the arbor is the clamp bolt 5, and the head portion 5b of the clamp bolt 5 has a through hole 6 having a diameter smaller than that of the accommodating hole 7 and the tip of the cutter body 1. Since the clamp bolt 5 is sandwiched between the opening of the insertion hole 8 having an inner diameter smaller than the outer diameter of the head 5b of the clamp bolt 5 that opens in the portion, the clamp bolt 5 does not come off from the cutter body 1. Therefore, the parts can be easily managed, and the clamp bolt 5 is not lost or the screw member is not scattered unlike the cutter clamp mechanism described in Patent Document 2.

Further, as described above, since the holes formed in the cutter body 1 for the clamp are only the through hole 6, the accommodating hole 7, and the insertion hole 8, the screw is also used as in the cutter clamp mechanism described in Patent Document 2. It is not necessary to form a mounting screw hole for screwing the member. Therefore, even if the coolant hole 1d for supplying the coolant to the cutting edge 3a is formed as in the present embodiment, the coolant does not leak due to the interference with the mounting screw hole.

Further, in the cutter clamp mechanism of the present embodiment, at least the accommodating hole 7 side of the inner peripheral surface of the insertion hole 8 is formed so as to gradually reduce the diameter toward the tip end side of the cutter body 1. Therefore, chips and dust that have entered the insertion hole 8 can be discharged to the tip end side of the cutter body 1 so as to be guided along the inner peripheral surface of the reduced diameter insertion hole 8. Such chips. And dust can be prevented from accumulating in the insertion hole 8.

On the other hand, in the method of manufacturing the cutter main body 1 provided with the cutter clamp mechanism of the present embodiment, the rear end portion of the cutter main body 1 and the front end portion of the cutter main body 1 are subjected to laminating processing using a 3D printer in the axis O direction. Among them, the head 5b is inserted in the radial direction with respect to the axis O in the insertion hole 8 at the height of the head 5b or more of the clamp bolt 5 from the plane P perpendicular to the axis O at the position of the bottom surface 7a facing the tip side in the accommodation hole 7. A portion within a range up to a possible position is formed, and then the flat surface P is smoothed to form a bottom surface 7a facing the tip end side of the accommodating hole 7, and then the threaded portion 5a of the clamp bolt 5 is formed. It is inserted through the through hole 6 to bring the rear end surface 5d of the head portion 5 into contact with the smoothed bottom surface 7a.

Therefore, since the degree of adhesion between the rear end surface 5d of the head portion 5b and the bottom surface 7a of the accommodating hole 7 can be improved, the cutter body 1 manufactured as a whole can be attached to the tip end portion of the arbor by the clamp bolt 5. When clamping, the rear end surface 5d of the head portion 5b of the clamp bolt 5 makes it possible to uniformly press the bottom surface 7a of the accommodating hole 7. Therefore, the cutter body 1 can be mounted on the arbor with even higher mounting rigidity, and the machining accuracy can be further improved.

The surface roughness of the flat surface P to be the bottom surface 7a subjected to the smoothing treatment is within the range of 1.6 μm to 12.5 μm in the maximum height roughness Rz in JIS B 0601: 2013 as described above. It is desirable to be.

If the maximum height roughness Rz exceeds 12.5 μm, the degree of adhesion between the rear end surface 5d of the head portion 5b of the clamp bolt 5 and the bottom surface 7a of the accommodating hole 7 cannot be sufficiently increased, and the above-mentioned effect can be obtained. On the other hand, it is difficult to smooth the plane P having the bottom surface 7a so that the maximum height roughness Rz is less than 1.6 μm.

Similarly, if the rear end surface 5d of the head portion 5b of the clamp bolt 5 is also subjected to the same smoothing treatment, the degree of adhesion to the bottom surface 7a of the accommodating hole 7 can be further improved. Can be mounted on the arbor with even higher mounting rigidity, and the machining accuracy can be further improved.

Furthermore, in the present embodiment, the case where the present invention is applied to the cutter clamp mechanism of a cutter with a replaceable cutting edge has been described. For example, a brazing type in which a cutting insert having a cutting edge is joined to a cutter body by brazing. Of course, it is also possible to apply the present invention to a cutter of the above, and in some cases, a solid type cutter in which a cutting edge is sharpened directly on the cutter body.

1 Cutter body 1c Mating hole 1d Coolant hole 2 Insert mounting seat 3 Cutting insert 3a Cutting edge 4 Mounting screw 5 Clamp bolt 5a Clamp bolt 5 screw part 5b Clamp bolt 5 head 5c Engagement part 5d Clamp bolt 5 head Rear end surface of part 5b 6 Through hole 7 Accommodating hole 7a Bottom surface of accommodating hole 7 8 Insertion hole O Axis of cutter body 1 T Cutter rotation direction P Plane of position of bottom surface 7a of accommodating hole 7

Claims (4)

It is a cutter clamp mechanism that clamps and attaches a cylindrical cutter body that can be rotated around the axis to an arbor with a clamp bolt.
A cutting edge is provided on the outer periphery of the tip of the cutter body, and
The inner peripheral portion of the cutter body has a through hole that opens at the rear end of the cutter body and through which the screw portion of the clamp bolt is inserted.
An accommodating hole having an inner diameter larger than that of the through hole, which communicates with the tip end side of the through hole and accommodates the head of the clamp bolt.
The insertion hole that communicates with the tip side of the accommodating hole, opens to the tip of the cutter body, and inserts a work tool that engages with the engaging portion formed on the tip surface of the clamp bolt. It is formed along the axis and
A cutter clamp mechanism characterized in that the inner diameter of the opening of the insertion hole at the tip of the cutter body is smaller than the outer diameter of the head of the clamp bolt. The cutter clamp mechanism according to claim 1, wherein at least the accommodating hole side of the inner peripheral surface of the insertion hole is gradually reduced in diameter toward the tip end side of the cutter body. The method for manufacturing a cutter body provided with the cutter clamp mechanism according to claim 1 or 2.
By laminating using a 3D printer, the rear end portion of the cutter body and the tip portion of the cutter body, which faces the tip side of the accommodating hole, are located on the bottom surface in the axial direction from a plane perpendicular to the axis. A portion above the height of the head of the clamp bolt and within a range up to a position where the head can be inserted in the radial direction with respect to the axis in the insertion hole is formed.
Next, the flat surface is smoothed to form a bottom surface facing the tip end side of the accommodating hole, and then the screw portion of the clamp bolt is inserted into the through hole to insert the rear end surface of the head into the bottom surface. In contact with
Further, a method for manufacturing a cutter body provided with a cutter clamp mechanism, which comprises forming the entire cutter body by laminating using a 3D printer. The third aspect of the present invention, wherein the surface roughness of the smoothed bottom surface is within the range of 1.6 μm to 12.5 μm in the maximum height roughness Rz in JIS B 0601: 2013. How to manufacture a cutter body equipped with a cutter clamp mechanism.

Images