JP2004050308A - Cutting tool, holder, and throwaway tip - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cutting tool for attaching a throwaway tip having a clamping hole by screwing a clamping screw into a holder, which cutting tool is able to cut a small diameter. <P>SOLUTION: A recess of a holder 11 for attaching the tip is provided such that the axis G1 of the holder 11 passes through the recess. The tip 30 has a clamping portion 31 to be clamped to the recess and a projecting part 41 which is integrated with the side part of the clamping portion 31 and projects from the tip end surface 18 of the holder 11. The projecting part 41 has a plurality of cutting edges 43. When the clamping portion 31 has been positioned in the recess for attaching the tip and the tip 30 has been attached by screwing a clamping screw 51, the axis G1 of the holder 11 coincides with the axis G2 of the projecting part 41. In this cutting tool, the outside diameter of the cutting edges 43 is reduced irrespective of the size of the clamping screw 51. Therefore, the outside diameter of the cutting edges 43 is reduced within the allowable range of strength. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a cutting tool for counterbore or drilling, a holder for mounting a throw-away tip that forms the cutting tool, and a throw-away tip thereof (hereinafter also referred to as a throw-away tip or simply a tip). In detail, a cutting tool that applies rotation to a workpiece and feeds the center of rotation in the axial direction to perform counterboring and drilling, or counterclockwise rotation and feeding to a fixed workpiece The present invention relates to a cutting tool for performing machining and drilling.
[0002]
[Prior art]
As an example of a conventional counterbore or drilling cutting tool (hereinafter also simply referred to as a tool), two indexable inserts with clamp holes are attached to the tip of a shaft-shaped holder (tool body). There is something. In this machine, a holder on which a chip is attached (fixed) is fixed to, for example, a tool post of an automatic lathe, and the axis of rotation of a rotating workpiece (work material) is used as an axis to press an axis of a tool to perform necessary processing ( For example, a counterbore at the opening end of the bolt hole).
[0003]
A throw-away insert with a clamp hole that is clamped to a holder that forms such a cutting tool (hereinafter, also simply referred to as a tool) usually has a plate-like shape, such as a quadrangle or a parallelogram, and has a main surface of the plate. A clamp hole penetrating in the thickness direction is provided at substantially the center of the (clamping portion). On the other hand, a screw hole is provided on the chip seating surface of the chip mounting concave portion of the holder, and the throw-away chip itself forming a clamping portion is arranged in the chip mounting concave portion, and the clamp screw is passed through the clamp hole. The tip was clamped by screwing it into the screw hole.
[0004]
[Problems to be solved by the invention]
However, in counterboring and drilling with a cutting tool having a configuration including such a chip with a clamp hole and a holder (hereinafter, also referred to as counterbore), there is naturally a limitation in processing a small hole due to its configuration. At most, a diameter of 10 mm was the minimum processing diameter. This is for the following reason. In such a cutting tool, the tip is attached by screwing in with a clamp screw. On the other hand, the width (length in the substantially radial direction) of the bottom cutting edge of one chip must be larger than the outer diameter of the clamp screw or the diameter (outer diameter) of its head. Therefore, even when a clamp screw having a minimum diameter of 5 mm and a minimum diameter is used in view of strength, the width of the bottom cutting edge is required to be 5 mm or more, for example.
[0005]
As described above, in a counterbore cutting tool having a configuration including a conventional holder and a tip having a clamp hole, the throw-away tip itself used forms a clamping portion. For this reason, the width of the bottom cutting edge is 5 mm at minimum, and therefore the processing diameter is about 10 mm at minimum, due to the restriction on the mounting of the chip.
[0006]
The present invention has been made in view of such a point, and an object of the present invention is to provide a cutting tool in which a tip having a clamp hole is attached to a holder by screwing a clamp screw, and a seat having a diameter of less than 10 mm is provided. An object of the present invention is to provide a machine capable of boring a hole or the like.
[0007]
[Means for Solving the Problems]
In order to solve the above-mentioned problem, the invention according to claim 1 has a tip mounting recess having a configuration in which a throw-away tip having a clamp hole is mounted by inserting a clamp screw into the clamp hole by a screwing method. A cutting tool, wherein the throw-away tip is attached by a screwing method to the tip attaching concave portion of a holder having an opening on the front end surface side and the outer peripheral surface side,
The chip mounting concave portion of the holder has a chip seat surface having a screw hole for inserting a clamp screw through which the axis of the holder passes through a space in the concave portion and on which the throw-away chip is seated, and a periphery of the chip seat surface. A rear wall for positioning the rear end in the axial direction of the holder when the throw-away tip is seated on the chip seating surface, and a positioning for the lateral side in the outer peripheral surface direction of the holder. With a horizontal wall
The throw-away tip includes a clamping portion having a bottom surface that sits on the tip seating surface of the tip mounting recess, a rear side surface positioned on the rear wall surface, and a lateral side surface positioned on the lateral wall surface. And
The clamp portion has a clamp hole at a position corresponding to the screw hole of the chip seat surface when positioned in the chip mounting concave portion,
The clamp portion is positioned by seating its bottom surface on the chip seating surface of the chip mounting concave portion, contacting the rear side surface with the rear wall surface, and contacting the lateral side surface with the lateral wall surface. At the time, the side of the clamping portion facing the distal end side is provided with a protruding portion that extends integrally from the side portion so as to protrude from the distal end surface of the holder, and has an axis coinciding with the axis of the holder,
The tip of the protrusion has a plurality of cutting edges formed so as to be able to cut by relatively rotating the workpiece around the axis of the protrusion,
The clamp portion of the throw-away tip is disposed in the tip mounting recess of the holder, the bottom surface is seated on the tip seating surface, and the rear side surface is in contact with the rear wall surface, and By positioning the side surface in contact with the lateral wall surface and inserting the clamp screw into the clamp hole and screwing into the screw hole, the throw-away tip is attached to the tip attachment recess of the holder by a screwing method. It is a cutting tool characterized by the following.
[0008]
According to the present invention, the cutting edge of the chip forming the cutting tool is provided not at the clamping portion having a screw hole for inserting the clamp screw into the chip mounting concave portion of the holder by screwing, but at the projecting portion extending therefrom. Therefore, the outer diameter of the cutting edge can be reduced regardless of the clamp screw. Therefore, since the cutting edge can be made small in a range that does not affect the strength, the cutting tool is configured to include a tip with a clamp hole and a holder, but it must be a cutting tool that can machine a hole with a sufficiently small diameter. Can be.
[0009]
The invention according to claim 2 is characterized in that, when the holder is viewed from the front end thereof in the axial direction, the lateral wall surface in the chip mounting recess faces in a direction rising from the chip seating surface, and is located in the chip mounting recess. The cutting according to claim 1, wherein the width of the space is formed to be narrow, and the lateral wall surface restricts the movement of the throw-away tip in a direction of rising from the tip seating surface. It is a tool.
[0010]
In the cutting tool according to claim 1, basically, a rotating workpiece is machined by giving only an axial feed to the tool, or a stationary workpiece is machined, and the cutting tool is rotated and rotated in the axial direction. Or machining with a feed of the same, and therefore a relative rotary cutting. For this reason, in the cutting tool of the present invention, any one side of the clamping portion that sandwiches the axis of the holder receives a lifting force due to the cutting resistance. In view of this, a part or the entirety of a side surface on one side of a clamp portion which receives a force that is lifted by cutting resistance is configured by the throw-away tip on the side wall surface. By restricting the movement in the direction of rising from the chip seat surface, it is possible to withstand the lifting force due to the cutting resistance, so that a stable mounting of the chip can be obtained.
[0011]
The invention according to claim 3 is the cutting tool according to claim 1 or 2, wherein the plurality of cutting edges are counterboring cutting edges.
[0012]
According to a fourth aspect of the present invention, there is provided a tip mounting recess having a configuration in which a throw-away tip having a clamp hole is mounted by inserting a clamp screw into the clamp hole by a screwing method. A holder having an opening in the cutting attachment by attaching the throw-away tip to the tip mounting recess by a screwing method,
The concave portion for chip mounting has a chip seat surface having a screw hole for inserting a clamp screw through which an axis of the holder passes through a space in the concave portion, and a seat for the throw-away chip, and a wall surface around the chip seat surface. When the throw-away tip is seated on the tip seating surface, the wall surface positions the rear end side in the axial direction of the holder and the lateral side position in the outer peripheral surface direction of the holder. It has a side wall and
A throwaway tip comprising a clamping portion having a bottom surface that sits on the tip seating surface of the tip mounting recess, a rear side surface positioned on the rear wall surface, and a lateral side surface positioned on the lateral wall surface. So,
The clamp portion has a clamp hole at a position corresponding to the screw hole of the chip seat surface when positioned in the chip mounting concave portion,
The clamp portion is positioned by seating its bottom surface on the chip seating surface of the chip mounting concave portion, contacting the rear side surface with the rear wall surface, and contacting the lateral side surface with the lateral wall surface. In this case, a side portion of the clamping portion facing the front end side is provided with a protruding portion that protrudes from the front end surface of the holder integrally from the side portion and extends, and an axis of which coincides with an axis of the holder. At the tip of the protrusion, the clamping portion of the throw-away tip comprising a plurality of cutting edges formed so as to be able to cut by relatively rotating the workpiece around the axis of the protrusion, It is arranged in the chip mounting recess, and the bottom surface is seated on the chip seat surface, and the rear side surface is brought into contact with the rear wall surface, and the lateral side surface is brought into contact with the lateral wall surface and positioned. Moni, by screwing in said screw hole by inserting the clamping screw to clamp hole, a holder, characterized in that it is configured for mounting by screwing method the cutting insert in the chip mounting recess.
[0013]
According to such a holder, the outer diameter of the cutting edge can be reduced irrespective of the clamp screw by mounting the throwaway tip according to claim 7 in the tip mounting recess by a screwing method. Can be used as a cutting tool.
[0014]
The invention according to claim 5 is characterized in that, when the holder is viewed from the front end thereof in the axial direction, the lateral wall surface in the chip mounting recess faces in a direction rising from the chip seating surface, and is located in the chip mounting recess. The holder according to claim 4, wherein the holder is formed so as to reduce the width of the space.
[0015]
According to the holder according to claim 5, the cutting tool according to claim 2 is obtained because the lateral wall surface can restrict the movement of the indexable insert in a direction rising from the chip seat surface. be able to.
[0016]
The invention according to claim 6 is the holder according to claim 4 or 5, wherein the plurality of cutting edges are counterbore cutting edges.
[0017]
According to a seventh aspect of the present invention, there is provided a throwaway with a clamp hole which is attached to a tip mounting concave portion which is opened at a distal end surface side and an outer peripheral surface side at a distal end of a holder by inserting a clamp screw into the clamp hole and screwing in. A chip,
The chip mounting concave portion of the holder has a chip seat surface having a screw hole for inserting a clamp screw through which the axis of the holder passes through a space in the concave portion and on which the throw-away chip is seated, and a periphery of the chip seat surface. A rear wall for positioning the rear end in the axial direction of the holder when the throw-away tip is seated on the chip seating surface, and a positioning for the lateral side in the outer peripheral surface direction of the holder. And a lateral wall that performs
The throw-away tip includes a clamping portion having a bottom surface that sits on the tip seating surface of the tip mounting recess, a rear side surface positioned on the rear wall surface, and a lateral side surface positioned on the lateral wall surface. And
The clamp portion has a clamp hole at a position corresponding to the screw hole of the chip seat surface when positioned in the chip mounting concave portion,
The clamp portion is positioned by seating its bottom surface on the chip seating surface of the chip mounting concave portion, contacting the rear side surface with the rear wall surface, and contacting the lateral side surface with the lateral wall surface. At the time, the side of the clamping portion facing the distal end side is provided with a protruding portion that extends integrally from the side portion so as to protrude from the distal end surface of the holder, and has an axis coinciding with the axis of the holder,
A throw-away tip comprising a plurality of cutting edges formed at a tip end of the protruding portion so as to be capable of cutting by relatively rotating a workpiece around an axis of the protruding portion. .
[0018]
According to such a throw-away insert, the cutting tool according to the first aspect can be formed by mounting the insert into the tip mounting recess of the holder according to the fourth aspect.
[0019]
The invention according to claim 8 is provided with an inclined surface that narrows the width of the clamping portion in a direction rising from the bottom surface, when the protrusion is viewed in the axial direction from the tip thereof. The indexable insert according to claim 7, wherein
[0020]
According to such a throw-away insert, the cutting tool according to the second aspect can be formed by attaching the insert to the tip-mounting concave portion of the holder according to the fifth aspect.
[0021]
The invention according to claim 9 is the indexable insert according to claim 7 or 8, wherein the plurality of cutting edges are counterbore cutting edges.
[0022]
BEST MODE FOR CARRYING OUT THE INVENTION
Next, an embodiment of such a cutting tool, holder and indexable insert will be described in detail with reference to FIGS. In the drawing, reference numeral 1 denotes a cutting tool, which is formed by mounting a throw-away tip 30 having a clamp hole in the tip mounting recess 14 at the tip of the holder 11 by a screwing method.
[0023]
Here, the holder 11 is composed of a parallel shaft-shaped shank 13 serving as a fixed portion to a tool post of an automatic lathe (not shown), and a large-diameter portion 15 forming a tip mounting concave portion 14 at the tip thereof. The parallel shaft-shaped shank 13 is a round bar-shaped shank, and is provided with chamfers 16 extending in the axial direction at four locations at equal intervals (90 degrees) when viewed from the axial direction on the outer peripheral surface having a circular cross section. Have been.
[0024]
On the other hand, the large-diameter portion 15 is formed by cutting out a large-diameter cylindrical portion that is coaxial with the parallel-shaft shank 13 in a split circle shape close to a half circle when one side near the tip is viewed from the tip side. It becomes. The concave portion 14 for chip attachment is formed in the flat portion 20 of the large-diameter portion 15 so as to open at the distal end surface 18 side and the outer peripheral surface 15a side at the distal end of the holder 11. However, when viewed from the opening side (see FIGS. 1 and 4), the chip mounting concave portion 14 has a substantially square shape (substantially square shape). The concave portion 14 for chip attachment is formed such that the axis G1 of the holder 11 passes through substantially the center of the space in the concave portion.
[0025]
The concave portion 14 for chip mounting has a chip seating surface 22 formed by a plane parallel to the flat portion 20 of the large diameter portion 15 with the axis G1 of the holder 11 interposed therebetween. The tip seating surface 22 is where the throw-away tip 30 is seated, and a screw hole 23 for screwing the clamp screw 51 is provided substantially at the center thereof. A wall surface is provided around the chip seating surface 22. This wall surface is provided with a rear wall surface 25 for positioning (restraining) the rear end side of the holder 11 in the direction of the axis G1 when the indexable tip is seated on the chip seating surface 22 on the rear end side of the axis G1. Moreover, it has the horizontal wall surfaces 26 and 27 parallel to the axis G1 when seen from the opening side. However, the upper lateral wall surface 26 in FIG. 4 is for positioning the lateral side in the outer peripheral surface direction of the holder 11, but the lower lateral wall surface 27 in FIG. Is set so that the interval is maintained (see FIGS. 1 and 3).
[0026]
Further, a portion of the rear wall surface 25 near the opening side slightly protrudes toward the space so as to reduce the width of the space in the chip mounting concave portion 14, and the protruding portion rises from the chip seating surface 22, An inclined surface (undercut) 25a that is inclined so as to reduce the width of the space (see FIG. 5). Further, the portion of the lateral wall surface 26 for positioning, which is closer to the opening side, slightly protrudes toward the space side so as to reduce the width of the space in the chip mounting concave portion 14, and the protruding portion rises from the chip seat surface 22. An inclined surface 26a is inclined in the direction so as to reduce the width of the space (see FIG. 6). This is for the following operation. At the time of cutting, one side of the chip 30 (the upper side in FIG. 1 in the present embodiment) receives a force in a direction of rising from the chip seating surface 22 by the cutting resistance. For this reason, the side portions (the upper side and the right side in FIG. 1) of the clamping portion 31 of the below-mentioned insert away tip 30 are made to enter here to prevent their floating (breakage of the clamp screw). It is. An escape portion 28 is recessed in the portion of the lateral wall surface 26 that is positioned near the rear wall surface 25, and a relief portion 29 is also recessed in the portion of the rear wall surface 25 that is not located near the horizontal wall surface 26. Has been established.
[0027]
On the other hand, the throw-away tip 30 is made of, for example, a cemented carbide, and includes a plate-like clamping portion 31 having a substantially square and constant thickness in plan view (see FIGS. 1 and 7), and a plate peripheral surface thereof. A projection 41 is provided which extends from the center of the one side portion 32 and extends in parallel with the bottom surface 33. The clamping portion 31 includes a bottom surface 33 that sits on the chip seating surface 22 of the chip mounting concave portion 14, a rear side surface 34 positioned on the rear wall surface 25, and a lateral side surface 35 positioned on the horizontal wall surface 26. . Note that the lower side surface 36 in FIG. 1 does not contribute to positioning. The bottom surface 33 and the front surface 37 of the clamp portion 31 are formed flat, and a clamp hole 38 is provided substantially in the center of the front surface 37 so as to penetrate in the thickness direction. However, the opening on the front surface 37 side of the clamp hole 38 is seated in a salami-fir shape so that the clamp screw 51 can be inserted in a recessed manner. When the projection 41 projects from the distal end face 18 of the holder 11 and the clamp portion 31 is positioned and mounted in the chip mounting recess 14, the axis G2 of the projection 41 and the axis of the holder 11 are aligned. G1 is formed so as to match. The positioning is performed by inserting the clamp screw 51 into the clamp hole 38 and screwing the screw into the screw hole 23 in the state where the clamp portion 31 is disposed in the chip mounting concave portion 14 as described above. . That is, by screwing in this way, the chip 30 is slightly drawn into the rear wall surface 25 and the side wall surface 26 side on the chip seating surface 22, and is tightened under the chip 30 so that the axes G1 and G2 coincide with each other. Have been.
[0028]
Further, in the present embodiment, the portions near the surface 37 on the rear side surface 34 and the lateral side surface 35 of the clamping portion 31 form inclined surfaces 34 a and 35 a that narrow the width of the clamping portion 31 toward the direction rising from the bottom surface 33. I have. In this embodiment, the thickness (side surface height) of the clamp portion 31 is set slightly larger than the depth (wall surface height) of the chip mounting recess 14. When the chip 30 is placed and mounted in the chip mounting recess 14 via the clamping portion 31, the inclined surface 34 a of the rear side surface 34 abuts against the inclined surface 25 a of the rear wall surface 25, The inclined surface 35 a of 35 is set so as to contact the inclined surface 26 a of the horizontal wall surface 26. When the chip 30 is attached, the inclined surface 34a of the rear side surface 34 is prevented from being lifted up by the inclined surface 25a of the rear wall surface 25, and the inclined surface 35a of the lateral side surface 35 is fixed by the inclined surface 26a of the lateral wall surface 26. It is configured such that lifting is prevented. In the present embodiment, the protrusion 41 has the same thickness as the clamping portion 31 and is formed to have a smaller width as viewed from the front surface 37 side. At the tip of the protruding portion 41, two cutting edges (counterbore with a diameter of 8.0 mm) formed so as to be able to cut the workpiece by relatively rotating the workpiece around its axis G2. Cutting blades) 43, 43 are provided symmetrically with respect to the point when viewed from the front end face side. Note that the protrusion amount of the protrusion 41 is 8.0 mm. The clamping portion 31 has two sides of 12 mm and 12 mm when viewed from the front surface 37 and a thickness of 6.0 mm. Further, the clamp hole 38 is formed so that, for example, an M4 clamp screw can be inserted in a recessed manner.
[0029]
Thus, the cutting tool 1 of the present embodiment is configured such that the throw-away tip 30 has its protruding portion 41 protruding from the distal end surface 18 of the holder 11 and the clamping portion 31 is attached to the tip of the holder 11. Is arranged in the concave portion 14. Then, a clamp screw 51 is inserted through the clamp hole 38 and screwed into the screw hole 23. By attaching (fixing) the chip 30 to the holder 11 in this manner, the cutting tool 1 in which the axis G2 of the two cutting edges 43 formed on the protrusion 41 coincides with the axis G1 of the holder 11 is formed.
[0030]
In such a cutting tool 1 of the present embodiment, the cutting tool includes the holder 11 and the tip 30 with the clamp hole 38, and the cutting edge 43 has the clamping portion 31 which forms an attachment portion to the holder 11. Is formed on the protrusion 41 formed separately. The chip 30 is attached to the holder 11 by inserting a clamp screw 51 from the clamp hole 38 of the clamp portion 31 and screwing the clamp screw 51 into the screw hole 23. Moreover, the axis G1 of the holder 11 coincides with the axis G2 of the protruding portion 41 and the cutting edge 43. Therefore, although the cutting tool includes the holder 11 and the tip 30 with the clamp hole 38, the outer diameter of the cutting edge 43 can be reduced regardless of the outer diameter of the head of the clamp screw 51. For this reason, the outer diameter of the protruding portion 41 and the cutting edge 43 formed on the protruding portion 41 can be reduced as long as there is no problem in cutting such as strength and chip discharge. Thus, it can be used as a cutting tool for spot facing less than 10 mm, which has conventionally been considered difficult to machine.
[0031]
In addition, in the present embodiment, when the workpiece is relatively rotated and the cutting is performed, the side of the side surface 35 (the upper side in FIG. 7 in the present embodiment) on the side where the cutting resistance tends to float on the tip 30 due to the cutting resistance is set to the tip. The inclined surfaces 25a and 26a of the rear wall surface 25 and the lateral wall surface 26 that form the mounting recess 14 are regulated so as to be pressed against the chip seat surface 22 side. For this reason, there is also an effect that stable chip fixation can be obtained. That is, in the present embodiment, the chip 30 is fixed by one clamp screw 51. However, since the structure is such that an excessive tensile stress does not act on the clamp screw 51, machining of a workpiece having a large cutting resistance is performed. Can also be used. In this embodiment, when the holder 11 is viewed from the front end surface 18 side, the holder 11 is relatively rotated counterclockwise to cut the fixed workpiece.
[0032]
Further, in the cutting tool 1 of the present embodiment, the holder 11 is fixed to, for example, a tool rest of an automatic lathe (not shown), and the work is cut by applying rotation. However, as long as the rotation of the holder 11 around the axis G1 does not cause a problem due to the centrifugal force acting on the chip 30, the stationary tool is used for cutting in a form in which the cutting tool 1 is rotated and machined. You can also.
[0033]
The specific shape of the cutting tool of the present invention, the holder and the chip forming the same, and the number and shape (structure) of the cutting edges of the protruding portions in the chip are not limited to those of the above-described embodiment, and are appropriately designed. Can be changed and embodied. For example, the holder is embodied as a straight shank having a circular cross section with a chamfer. However, the holder can be embodied as a tapered shank having a circular cross section or a straight shank having a square cross section. The holder may be formed in accordance with the attachment to the processing machine. Further, the chip mounting recess may be any as long as it can position and mount the chip. Therefore, it may be set according to the shape of the clamping portion of the chip.
[0034]
Further, with respect to the chip, the protrusion amount of the protrusion may be set according to the depth of a processing hole or the like. Also, the diameter of the cutting edge at the tip can be appropriately determined according to the size of the processing diameter. Further, the type of the cutting edge is not limited to the counterbore cutting edge, and may be determined according to the processing. Further, the shape of the clamping portion of the chip may be any shape as long as it can be positioned and mounted in the chip mounting recess. That is, as long as it can be positioned and mounted in the chip mounting recess, its shape is not limited. In the above description, the structure is such that the chip is attached with one clamp screw, but the structure can be embodied as a structure in which the chip is attached with a plurality of clamp screws. Furthermore, if it is used only for light cutting without the problem of chip lifting (problem of clamp screw breakage) due to the hardness or machinability of the workpiece, a structure that regulates chip lifting as in the above embodiment. You don't have to.
[0035]
【The invention's effect】
As is clear from the above description, according to the present invention, the cutting edge of the insert that forms the cutting tool is not a clamped portion having a screw hole that is screwed into the chip mounting concave portion of the holder, but from this clamped portion. It is provided on the extending protrusion. For this reason, the outer diameter of the cutting edge can be reduced by making the protruding portion thin regardless of the clamp screw, so that the cutting edge can have a small diameter as long as the strength is not affected. That is, in the present invention, a cutting tool having a configuration including a tip and a holder with a clamp hole, but a cutting tool that can be used for drilling a counterbored hole having a sufficiently small diameter such as less than φ10 mm. Can be.
[0036]
And according to the holder and the tip of the present invention, the cutting tool of the present invention having the above-mentioned effects can be obtained.
[Brief description of the drawings]
FIG. 1 is a view of an embodiment of a cutting tool according to the present invention as viewed from a tip mounting recess side, and an enlarged view of a main part thereof.
FIG. 2 is an enlarged view of a main portion of a center transverse fracture section of the cutting tool of FIG. 1;
FIG. 3 is an enlarged view of the cutting tool of FIG. 1 as viewed from a tip end side of a holder.
FIG. 4 is an enlarged view of a main part of the holder forming the cutting tool of FIG. 1 as viewed from the side of the concave portion for chip attachment;
FIG. 5 is an exploded view of the cutting tool including an enlarged view of a main part of a center transverse cross section of the holder.
FIG. 6 is an enlarged view of a main portion of a central transverse fracture section as viewed from a front end surface side of a holder forming the cutting tool of FIG. 1;
FIG. 7 is a front view of the indexable insert that forms the cutting tool of FIG. 1;
FIG. 8 is a left side view of the indexable insert that forms the cutting tool of FIG. 1;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Cutting tool 11 Holder 14 Chip mounting recess 18 Holder tip surface 22 Chip seating surface 23 Screw hole 25 for insertion of clamp screw 25 Rear wall surface 25a of chip mounting concave surface Slant surface 26 of rear wall surface in chip mounting concave portion 26 Chip mounting Horizontal wall surface 26a of the concave portion Slope 30 of the horizontal wall surface in the chip mounting concave portion Throwaway tip 31 Clamping portion 32 Side portion 33 of the clamping portion facing the tip side Bottom surface of throwaway tip 34 Rear surface 35 of throwaway tip Throw Lateral side surface 35a of the away tip Inclined surface 38 on the lateral side of the throw away tip Clamp hole 41 Projecting portion 43 Cutting edge 51 at the tip of the projecting portion Clamp screw G1 Axis line G2 of the holder Axis line of the projecting portion

Claims (9)

The tip of a holder having a tip mounting recess having a configuration in which a throw-away tip with a clamp hole is attached by a screwing method by inserting a clamp screw into the clamp hole and opening at a tip end side and an outer peripheral side at a tip end. A cutting tool in which the throw-away tip is mounted in a mounting recess by a screwing method,
The chip mounting concave portion of the holder has a chip seat surface having a screw hole for inserting a clamp screw through which the axis of the holder passes through a space in the concave portion and on which the throw-away chip is seated, and a periphery of the chip seat surface. A rear wall for positioning the rear end in the axial direction of the holder when the throw-away tip is seated on the chip seating surface, and a positioning for the lateral side in the outer peripheral surface direction of the holder. With a horizontal wall
The throw-away tip includes a clamping portion having a bottom surface that sits on the tip seating surface of the tip mounting recess, a rear side surface positioned on the rear wall surface, and a lateral side surface positioned on the lateral wall surface. And
The clamp portion has a clamp hole at a position corresponding to the screw hole of the chip seat surface when positioned in the chip mounting concave portion,
The clamp portion is positioned by seating its bottom surface on the chip seating surface of the chip mounting concave portion, contacting the rear side surface with the rear wall surface, and contacting the lateral side surface with the lateral wall surface. At the time, the side of the clamping portion facing the distal end side is provided with a protruding portion that extends integrally from the side portion so as to protrude from the distal end surface of the holder, and has an axis coinciding with the axis of the holder,
The tip of the protrusion has a plurality of cutting edges formed so as to be able to cut by relatively rotating the workpiece around the axis of the protrusion,
The clamp portion of the throw-away tip is disposed in the tip mounting recess of the holder, the bottom surface is seated on the tip seating surface, and the rear side surface is in contact with the rear wall surface, and By positioning the side surface in contact with the lateral wall surface and inserting the clamp screw into the clamp hole and screwing into the screw hole, the throw-away tip is attached to the tip attachment recess of the holder by a screwing method. A cutting tool characterized by the following. When the holder is viewed from its tip in the axial direction, the lateral wall surface in the chip mounting recess is formed so as to narrow the width of the space in the chip mounting recess toward a direction rising from the chip seating surface. 2. The cutting tool according to claim 1, wherein the lateral wall restricts movement of the indexable insert in a direction in which the insert away from the insert seat surface rises. 3. The cutting tool according to claim 1, wherein the plurality of cutting edges are counterbore cutting edges. A holder having a tip mounting concave portion configured to mount a throw-away tip with a clamp hole by inserting a clamp screw into the clamp hole and screwing in, and having an opening at a tip end side and an outer peripheral side at a tip end, In the cutting tool by mounting the throw-away tip in the tip mounting recess by a screwing method,
The concave portion for chip mounting has a chip seat surface having a screw hole for inserting a clamp screw through which an axis of the holder passes through a space in the concave portion, and a seat for the throw-away chip, and a wall surface around the chip seat surface. When the throw-away tip is seated on the tip seating surface, the wall surface positions the rear end side in the axial direction of the holder and the lateral side position in the outer peripheral surface direction of the holder. It has a side wall and
A throwaway tip comprising a clamping portion having a bottom surface that sits on the tip seating surface of the tip mounting recess, a rear side surface positioned on the rear wall surface, and a lateral side surface positioned on the lateral wall surface. So,
The clamp portion has a clamp hole at a position corresponding to the screw hole of the chip seat surface when positioned in the chip mounting concave portion,
The clamp portion is positioned by seating its bottom surface on the chip seating surface of the chip mounting concave portion, contacting the rear side surface with the rear wall surface, and contacting the lateral side surface with the lateral wall surface. In this case, a side portion of the clamping portion facing the front end side is provided with a protruding portion that protrudes from the front end surface of the holder integrally from the side portion and extends, and an axis of which coincides with an axis of the holder. At the tip of the protrusion, the clamping portion of the throw-away tip comprising a plurality of cutting edges formed so as to be able to cut by relatively rotating the workpiece around the axis of the protrusion, It is arranged in the chip mounting recess, and the bottom surface is seated on the chip seat surface, and the rear side surface is brought into contact with the rear wall surface, and the lateral side surface is brought into contact with the lateral wall surface and positioned. Moni, wherein by screwing said screw hole by inserting the clamping screw to clamp hole, the holder, characterized in that it is configured for mounting by screwing method the cutting insert in the chip mounting recess. When the holder is viewed from its tip in the axial direction, the lateral wall surface in the chip mounting recess is formed so as to narrow the width of the space in the chip mounting recess toward a direction rising from the chip seating surface. The holder according to claim 4, wherein the holder is provided. The holder according to claim 4, wherein the plurality of cutting edges are counterbore cutting edges. A throw-away tip with a clamp hole, which is attached to a tip attachment concave portion which is opened at a tip end side and an outer peripheral side at a tip end of a holder by inserting a clamp screw into the clamp hole and screwing in,
The chip mounting concave portion of the holder has a chip seat surface having a screw hole for inserting a clamp screw through which the axis of the holder passes through a space in the concave portion and on which the throw-away chip is seated, and a periphery of the chip seat surface. A rear wall for positioning the rear end in the axial direction of the holder when the throw-away tip is seated on the chip seating surface, and a positioning for the lateral side in the outer peripheral surface direction of the holder. And a lateral wall that performs
The throw-away tip includes a clamping portion having a bottom surface that sits on the tip seating surface of the tip mounting recess, a rear side surface positioned on the rear wall surface, and a lateral side surface positioned on the lateral wall surface. And
The clamp portion has a clamp hole at a position corresponding to the screw hole of the chip seat surface when positioned in the chip mounting concave portion,
The clamp portion is positioned by seating its bottom surface on the chip seating surface of the chip mounting concave portion, contacting the rear side surface with the rear wall surface, and contacting the lateral side surface with the lateral wall surface. At the time, the side of the clamping portion facing the distal end side is provided with a protruding portion that extends integrally from the side portion so as to protrude from the distal end surface of the holder, and has an axis coinciding with the axis of the holder,
A throwaway tip, comprising a plurality of cutting edges formed at a tip end of the protruding portion so as to be capable of cutting by relatively rotating a workpiece around an axis of the protruding portion. 8. The projection according to claim 7, wherein the side surface includes an inclined surface that narrows a width of the clamp portion in a direction rising from the bottom surface when the protrusion is viewed in an axial direction from a tip end thereof. The throw-away tip described in. The indexable insert according to claim 7 or 8, wherein the plurality of cutting edges are counterbore cutting edges.

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