Holder for blade edge replaceable cutting tool and blade edge replaceable cutting tool

Abstract

To provide a holder for a blade edge replaceable cutting tool which can achieve downsizing of a holder body even when including a plurality of cutting inserts, and to provide a blade edge replaceable cutting tool.SOLUTION: A holder for a blade edge replaceable cutting tool includes: a holder body; and a fixing member which fixes a pair of cutting inserts to an insert attachment seat. The insert attachment seat has: a first seating surface with which a first cutting insert contacts; a second seating surface with which a second cutting insert contacts; and a through hole. The fixing member includes: a bolt having a shaft part which is inserted into an insertion hole formed at the first cutting insert, the through hole of the holder, and an insertion hole formed at the second cutting insert; and a nut configured to be threadedly engaged with a tip of the bolt.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to a holder for an indexable cutting tool and an indexable cutting tool. [Background technology]

[0002] Conventionally, a configuration in which a plurality of cutting inserts for cutting processing are attached to a holder body of an indexable cutting tool is known. For example, Patent Document 1 discloses a configuration in which two cutting inserts (polygonal columns) having cutting edges can be attached to a mounting surface of a holder body (throw-away tip). In this configuration, each of the two cutting inserts is fixed to a screw hole formed in the holder body by using a mounting screw. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Unexamined Patent Publication No. 127913 / 1983 Summary of the Invention [Problem to be solved by the invention]

[0004] In the above-mentioned configuration, two mounting screws are required to mount two cutting inserts to the holder body, which requires space to accommodate the two mounting screws, preventing the holder body and the indexable cutting tool from being made smaller in diameter.

[0005] In view of the above circumstances, one object of the present invention is to provide a holder for an indexable cutting tool, and an indexable cutting tool, which enable the holder body to be made smaller in diameter even when multiple cutting inserts are provided. [Means for solving the problem]

[0006] One embodiment of the holder for an indexable cutting tool of the present invention comprises a holder body having an insert mounting seat extending in a tool axial direction along a tool center axis and capable of mounting a pair of cutting inserts having cutting edges, and a fixing member for removably fixing the pair of cutting inserts to the insert mounting seat, wherein the insert mounting seat has a first seating surface facing a first radial side of the holder body intersecting the tool axial direction and with which the first cutting insert comes into contact, a second seating surface facing a second radial side and with which the second cutting insert comes into contact, and a through hole penetrating the insert mounting seat in the radial direction connecting the first seating surface and the second seating surface, and the fixing member comprises a bolt having a shaft portion that is inserted from the first radial side toward the second radial side, through an insertion hole formed in the first cutting insert, the through hole, and an insertion hole formed in the second cutting insert, and a nut that is screwed to a tip portion of the bolt from the second radial side.

[0007] According to one aspect of the holder for indexable cutting tools of the present invention, the first cutting insert and the second cutting insert are fixed to the insert mounting seat by a fixing member including a bolt and a nut. The bolt is inserted through the insertion hole of the first cutting insert, the through hole of the insert mounting seat, and the insertion hole of the second cutting insert, and the nut is screwed to the tip of the bolt. In this way, the first cutting insert and the second cutting insert can be attached to the insert mounting seat by one bolt and nut. Therefore, there is no need to secure a space for arranging multiple bolts at the tip of the holder body, and the diameter of the holder body and the indexable cutting tool can be reduced. In addition, when attaching the first cutting insert and the second cutting insert to the insert mounting seat, it is only necessary to fasten one bolt and nut, so that the attachment work can be performed efficiently. In addition, the cost can be reduced by reducing the number of parts.

[0008] In the above-mentioned indexable cutting tool holder, the through hole may have a female thread portion formed on an inner surface of the through hole, and the bolt may have a first male thread portion formed at a tip portion of the shank and into which the nut can be screwed, and a second male thread portion formed at an intermediate portion of the shank and into which the nut can be screwed.

[0009] In this case, the bolt has a first male threaded portion into which the nut can be screwed, and a second male threaded portion into which the female threaded portion of the through hole can be screwed. As a result, when attaching the first cutting insert and the second cutting insert to the insert mounting seat, the first cutting insert can be sandwiched and fixed between the first seating surface and the head of the bolt by screwing the second male threaded portion into the female threaded portion of the through hole. Thereafter, the second cutting insert can be sandwiched and fixed between the second seating surface and the nut by screwing the nut into the first male threaded portion formed on the tip of the shaft portion of the bolt. As a result, the first cutting insert and the second cutting insert can be sequentially and individually fixed by a single bolt and nut.

[0010] In the above-mentioned indexable cutting tool holder, the second male threaded portion may have a larger diameter than the first male threaded portion.

[0011] In this case, when the shank of the bolt is inserted into the through hole from the first side to the second side in the radial direction, the first male thread portion has a smaller diameter than the second male thread portion, so that the tip of the shank of the bolt can be inserted into the through hole while preventing the first male thread portion from interfering with the female thread portion of the through hole. This makes it possible to efficiently attach the pair of cutting inserts using the bolt.

[0012] In the above-mentioned indexable cutting tool holder, the insert mounting seat may be plate-shaped and extend along a plane that passes through the tool center axis and connects the first seating surface and the second seating surface, intersecting the radial direction.

[0013] In this case, the first cutting insert and the second cutting insert are attached to a first side and a second side in the radial direction of a plate-shaped insert mounting seat that passes through the tool center axis and extends along a plane that intersects with the radial direction. With the insert mounting seat sandwiched between the first cutting insert and the second cutting insert, the first cutting insert and the second cutting insert can be firmly fixed by fastening them with bolts and nuts.

[0014] In the above-mentioned indexable cutting tool holder, the bolt may have a head having an outer diameter larger than that of the shaft, and the head may have a tapered bolt seat that contacts a tapered surface formed at an end of the insertion hole of the first cutting insert.

[0015] In this case, by bringing the tapered bolt seating surface formed on the head of the bolt into contact with the tapered surface of the first cutting insert, the first cutting insert can be accurately positioned in a direction along the first seating surface.

[0016] In the above-mentioned indexable cutting tool holder, the nut may have a tapered nut seating surface that contacts a tapered surface formed at an end of the insertion hole of the second cutting insert.

[0017] In this case, by bringing the tapered nut seating surface formed on the nut into contact with the tapered surface of the second cutting insert, the second cutting insert can be positioned with high accuracy in a direction along the second seating surface.

[0018] In the above-mentioned replaceable cutting tool holder, the insert mounting seat may further have a first receiving surface formed on one circumferential side about the tool center axis with respect to the first seating surface, facing the other circumferential side, and contacting the first cutting insert, and a second receiving surface formed on one circumferential side about the tool center axis with respect to the second seating surface, facing the other circumferential side, and contacting the second cutting insert.

[0019] In this case, the insert mounting seat has a first receiving surface and a second receiving surface, and by bringing the first cutting insert into contact with the first receiving surface and the second cutting insert into contact with the second receiving surface, when the holder body is attached to a processing machine and rotated to the other side in the circumferential direction around the tool axis to process a workpiece, the reaction force that the first cutting insert and the second cutting insert receive from the workpiece can be firmly received by the first receiving surface and the second receiving surface.

[0020] One aspect of the indexable cutting tool of the present invention comprises the above-described indexable cutting tool holder, and a pair of cutting inserts attached to the insert mounting seats.

[0021] According to one aspect of the indexable cutting tool of the present invention, there is no need to secure space at the tip of the holder body to place multiple bolts, and the holder body and the indexable cutting tool can be made smaller in diameter. Effect of the Invention

[0022] According to the indexable cutting tool holder and indexable cutting tool of one aspect of the present invention, even when a plurality of cutting inserts are provided, the diameter of the holder body can be reduced. [Brief description of the drawings]

[0023] [Figure 1] FIG. 1 is a perspective view of a holder for an indexable cutting tool and an indexable cutting tool according to one embodiment of the present invention. [Diagram 2] FIG. 2 is a side view of the indexable cutting tool holder and the indexable cutting tool according to one embodiment of the present invention. [Diagram 3] FIG. 3 is a view of the indexable cutting tool according to one embodiment of the present invention, viewed from the tip side in the tool axial direction. [Figure 4] FIG. 4 is a cross-sectional view taken along line AA in FIG. [Diagram 5] FIG. 5 is a perspective view of a bolt constituting the indexable cutting tool holder of one embodiment of the present invention. [Figure 6] FIG. 6 is a perspective view of a nut constituting the indexable cutting tool holder of one embodiment of the present invention. [Figure 7] FIG. 7 is a cross-sectional view of a cutting tool with an indexable tip in a first modified example of an embodiment of the present invention. [Figure 8] FIG. 8 is a cross-sectional view of a cutting tool with an indexable tip in a second modified example of an embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0024] Hereinafter, an indexable cutting tool holder according to one embodiment of the present invention and an indexable cutting tool 1, which is an example of an indexable cutting tool, will be described with reference to the drawings. The indexable cutting tool 1 according to the embodiment of the present invention is an end mill that is detachably attached to a spindle of a processing machine such as a milling machine, machining center, or multi-tasking machine (not shown) and performs cutting on a workpiece made of a metal material such as steel.

[0025] [Schematic configuration of indexable cutting tool] As shown in FIGS. 1 to 4, an indexable cutting tool 1 includes an indexable cutting tool holder 2 and a pair of cutting inserts 100 detachably attached to the indexable cutting tool holder 2.

[0026] [Configuration of the holder body of the indexable cutting tool holder] The indexable cutting tool holder 2 includes a holder body 20 and a fixing member 30A. The holder body 20 as a whole extends in a tool axis direction X along the tool center axis C. The holder body 20 integrally includes a shank portion 20a and a cutting edge portion 20b. In the following description, the direction connecting the shank portion 20a and the cutting edge portion 20b in the holder body 20 is defined as the tool axis direction X. In addition, in the holder body 20, the direction perpendicular to the tool axis direction X and connecting a first seating surface 26A and a second seating surface 26B of the insert mounting seat 25A described below is defined as the radial direction R. In addition, the direction around the tool center axis C is defined as the circumferential direction T (tool rotation direction).

[0027] The shank portion 20a has a cylindrical shape extending in the tool axial direction X. The shank portion 20a is gripped by a spindle of a processing machine (not shown). The cutting edge portion 20b is provided on one side of the shank portion 20a in the tool axial direction X. The cutting edge portion 20b has a generally cylindrical shape with a smaller diameter than the shank portion 20a.

[0028] The cutting edge portion 20b is provided with a first insert mounting portion 21A to which the first cutting insert 100P of the pair of cutting inserts 100 can be attached, and a second insert mounting portion 21B to which the second cutting insert 100Q of the pair of cutting inserts 100 can be attached. Each of the first insert mounting portion 21A and the second insert mounting portion 21B is provided so as to be recessed from the outer circumferential surface of the cutting edge portion 20b toward the inner circumferential side of the cutting edge portion 20b. The first insert mounting portion 21A and the second insert mounting portion 21B are configured point symmetrically with respect to the tool central axis C.

[0029] 3 and 4, a plate-shaped insert mounting seat 25A is provided on the cutting edge portion 20b. A pair of cutting inserts 100 (a first cutting insert 100P and a second cutting insert 100Q) are removably attached to the insert mounting seat 25A. The insert mounting seat 25A has a first seating surface 26A, a second seating surface 26B, and a through hole 27 (see FIG. 4).

[0030] The first seating surface 26A is a plane facing a first side R1 in a radial direction R of the holder body 20 intersecting with the tool axis direction X. A first cutting insert 100P, which will be described later, comes into contact with the first seating surface 26A. The second seating surface 26B is a plane facing a second side R2 in the radial direction R. The second seating surface 26B is parallel to the first seating surface 26A. A second cutting insert 100Q, which will be described later, comes into contact with the second seating surface 26B. The insert mounting seat 25A, which has a first seating surface 26A and a second seating surface 26B facing opposite directions, is plate-shaped when viewed from the tool axial direction X and extends along a plane that passes through the tool central axis C and intersects with the radial direction R connecting the first seating surface 26A and the second seating surface 26B.

[0031] 4, the through hole 27 penetrates the insert mounting seat 25A in a radial direction R connecting the first seating surface 26A and the second seating surface 26B. An internal thread portion 27n is provided on the inner circumferential surface of the through hole 27.

[0032] A first receiving surface 28A is provided on one side T1 in the circumferential direction T about the tool center axis C with respect to the first seating surface 26A. The first receiving surface 28A is provided so as to rise from an end of the first seating surface 26A on the one side T1 in the circumferential direction T. The first receiving surface 28A is provided so as to face the other side T2 in the circumferential direction T (the front side in the tool rotation direction). A relief recess 29A is provided at the boundary between the first seating surface 26A and the first receiving surface 28A to avoid interference with a first cutting insert 100P described below.

[0033] A second receiving surface 28B is provided on one side T1 in the circumferential direction T about the tool center axis C with respect to the second seating surface 26B. The second receiving surface 28B is provided so as to rise from an end of the second seating surface 26B on the one side T1 in the circumferential direction T. The second receiving surface 28B is provided so as to face the other side T2 in the circumferential direction T (the front side in the tool rotation direction). A clearance recess 29B is provided at the boundary between the second seating surface 26B and the second receiving surface 28B to avoid interference with a second cutting insert 100Q described later.

[0034] The first insert attachment portion 21A includes the above-mentioned first seating surface 26A and first receiving surface 28A, as well as an axial receiving surface 22A (see FIG. 2) that supports the first cutting insert 100P in the tool axial direction X. The second insert attachment portion 21B includes the above-mentioned second seating surface 26B and the second receiving surface 28B, as well as an axial receiving surface (not shown) that supports the second cutting insert 100Q in the tool axial direction X.

[0035] 1 to 3, a recessed chip discharge groove 23 extends from the end of each of the first insert mounting part 21A and the second insert mounting part 21B on the shank portion 20a side toward the shank portion 20a in the tool axial direction X. An end of a coolant passage 24 provided in the shank portion 20a opens into the inner surface of the chip discharge groove 23.

[0036] [Configuration of cutting insert] The pair of cutting inserts 100 includes a first cutting insert 100P and a second cutting insert 100Q. The first cutting insert 100P and the second cutting insert 100Q have the same structure, except for the mounting positions relative to the insert mounting seat 25A. Therefore, hereinafter, the first cutting insert 100P and the second cutting insert 100Q will be simply referred to as cutting insert 100, except when it is necessary to distinguish between them.

[0037] As shown in FIGS. 3 and 4, the cutting insert 100 has a first surface 101, a second surface 102, an outer peripheral side surface 103, a cutting edge 104, and an insertion hole 105 (see FIG. 4).

[0038] The first surface 101 and the second surface 102 face opposite sides in the sheet thickness direction of the cutting insert 100. The first surface 101 and the second surface 102 are polygonal in plan view when viewed from the sheet thickness direction. In this embodiment, the first surface 101 and the second surface 102 are parallelogram in plan view when viewed from the sheet thickness direction. The outer peripheral side surface 103 connects the peripheries of the first surface 101 and the second surface 102 to each other.

[0039] The cutting edge 104 is provided at an acute corner 100c of the diamond formed by the cutting insert 100. The cutting edge 104 is provided at an intersection ridge between the outer peripheral side surface 103 and the first surface 101. As shown in FIG. 2, in this embodiment, the cutting insert 100 has a point-symmetric shape around the center of the first surface 101, and the cutting edge 104 is provided at each of two corners 100c located diagonally in the cutting insert 100. As shown in FIGS. 1, 3, and 4, the cutting insert 100 in this embodiment has a rake face 108 formed on the outer peripheral side surface 103 on the inner peripheral side of the cutting insert with respect to the cutting edge 104. In this embodiment, the cutting insert 100 is a so-called vertical type in which the rake face 108 of the cutting edge 104 is formed on the outer peripheral side surface 103.

[0040] 4, the cutting insert 100 of this embodiment is a double-sided insert with a front-back symmetrical shape. Therefore, the cutting edge 104 is provided at each of the intersection ridges between the outer peripheral side surface 103 and the first surface 101 and the second surface 102. The cutting insert 100 may be a single-sided insert in which the cutting edge 104 is provided only at the intersection ridges between the outer peripheral side surface 103 and the first surface 101.

[0041] The through hole 105 is provided in the center of the cutting insert 100. The through hole 105 is provided in the thickness direction of the cutting insert 100, penetrating the first surface 101 and the second surface 102. In the through hole 105, a tapered surface 105a that gradually expands in diameter toward the first surface 101 side is provided at the end on the first surface 101 side. Since the cutting insert 100 of this embodiment is a double-sided insert with a front-back symmetrical shape, the tapered surface 105a is also provided in the through hole 105 at the end on the second surface 102 side.

[0042] The cutting inserts 100 are provided on both sides of the insert mounting seat 25A. The first cutting insert 100P is disposed on the first insert mounting portion 21A on the first side R1 in the radial direction R with respect to the insert mounting seat 25A. The second cutting insert 100Q is disposed on the second insert mounting portion 21B on the second side R2 in the radial direction R with respect to the insert mounting seat 25A.

[0043] The first cutting insert 100P is fixed to the insert mounting seat 25A by the fixing member 30A described below, with the second surface 102 in contact with the first seating surface 26A of the insert mounting seat 25A and two adjacent surfaces of the outer peripheral side surface 103 in contact with the first receiving surface 28A and the axial receiving surface 22A. The second cutting insert 100Q is fixed to the insert mounting seat 25A by the fixing member 30A described below, with the second surface 102 in contact with the second seating surface 26B of the insert mounting seat 25A and two adjacent surfaces of the outer peripheral side surface 103 in contact with the second receiving surface 28B and the axial receiving surface of the second insert mounting portion 21B.

[0044] [Configuration of fixing member] The fixing member 30A detachably fixes the pair of cutting inserts 100 (the first cutting insert 100P and the second cutting insert 100Q) to the insert mounting seat 25A. The fixing member 30A includes a bolt 31A and a nut 32.

[0045] FIG. 5 is a perspective view of a bolt constituting the indexable cutting tool holder of one embodiment of the present invention. 4 and 5, the bolt 31A has a shaft 33A and a head 34 provided on the base end side of the shaft 33A. The shaft 33A extends in the direction of its central axis. The shaft 33A has an expanded diameter portion 37 in the middle between the tip end and the base end, the expanded diameter portion being larger than the tip end and the base end.

[0046] The shaft portion 33A has a first male thread portion 35 and a second male thread portion 36. The first male thread portion 35 is provided on the outer peripheral surface of the tip portion of the shaft portion 33A. A nut 32 described below can be screwed into the first male thread portion 35. The second male thread portion 36 is provided on the outer peripheral surface of an expanded diameter portion 37 in the middle portion of the shaft portion 33A. The second male thread portion 36 is provided so as to be screwable into the female thread portion 27n of the through hole 27 of the insert mounting seat 25A. The second male thread portion 36 has a larger diameter than the first male thread portion 35.

[0047] Head 34 is provided on the base end side of shaft 33A and has a larger diameter than shaft 33A. Head 34 has an outer diameter larger than shaft 33A. The head 34 has a bolt seat 34z on the shaft 33A side. The bolt seat 34z is tapered so as to gradually reduce in diameter toward the shaft 33A side. The bolt seat 34z is provided so as to come into contact with the tapered surface 105a of the cutting insert 100. Head 34 has tool engagement portion 34t that can engage with the tip of a tool for rotating bolt 31A. Tool engagement portion 34t is provided to match the shape of the tip of a tool used to rotate bolt 31A. In this embodiment, tool engagement portion 34t is a recess having a shape that can be engaged with, for example, the tip of a hex lobe wrench.

[0048] FIG. 6 is a perspective view of a nut constituting the indexable cutting tool holder of one embodiment of the present invention. As shown in Fig. 4, the nut 32 is screwed onto the tip of the shaft portion 33A of the bolt 31A. As shown in Fig. 4 and Fig. 6, the nut 32 has a female screw hole 32n into which the tip of the bolt 31A can be screwed. The nut 32 has a nut seat 32z on the side facing the cutting insert 100 (the second cutting insert 100Q). The nut seat 32z is provided in a tapered shape that gradually reduces in diameter toward the cutting insert 100 side. The nut seat 32z is provided so as to contact the tapered surface 105a of the cutting insert 100. The nut 32 also has a tool engagement portion 32t that can engage with the tip of a tool for rotating the nut 32. The tool engagement portion 32t is provided to match the shape of the tip of a tool used to rotate the nut 32. In this embodiment, the tool engagement portion 32t is a groove that can be engaged with, for example, the tip of a flat-head screwdriver.

[0049] 4, in the fixing member 30A, the bolt 31A is inserted through the insertion hole 105 formed in the first cutting insert 100P, the through hole 27, and the insertion hole 105 formed in the second cutting insert 100Q from the first side R1 to the second side R2 in the radial direction R. At this time, the second male threaded portion 36 provided in the middle portion of the shaft portion 33A of the bolt 31A is screwed into the female threaded portion 27n of the through hole 27 of the insert mounting seat 25A. Also, the nut 32 is screwed into the first male threaded portion 35 at the tip portion of the bolt 31A.

[0050] As a result, the first cutting insert 100P and the second cutting insert 100Q are attached to the insert mounting seat 25A on the first side R1 and the second side R2 in the radial direction R. The first cutting insert 100P and the second cutting insert 100Q are fastened by the bolt 31A and the nut 32 with the insert mounting seat 25A sandwiched between the first cutting insert 100P and the second cutting insert 100Q. The first cutting insert 100P is fixed by being sandwiched between the first seating surface 26A and the head 34 of the bolt 31A as the second male screw portion 36 is screwed into the female screw portion 27n of the through hole 27. The second cutting insert 100Q is fixed by being sandwiched between the second seating surface 26B and the nut 32.

[0051] In addition, the tapered bolt seat 34z formed on the head 34 of the bolt 31A contacts (fits) the tapered surface 105a of the first cutting insert 100P, thereby positioning the first cutting insert 100P in a direction along the first seating surface 26A. Similarly, the tapered nut seat 32z formed on the nut 32 contacts (fits) the tapered surface 105a of the second cutting insert 100Q, thereby positioning the second cutting insert 100Q in a direction along the second seating surface 26B.

[0052] Here, the through hole 27 of the insert mounting seat 25A may be provided eccentrically toward the first receiving surface 28A and the second receiving surface 28B with respect to the insertion hole 105, with the outer peripheral side surface 103 of the first cutting insert 100P and the second cutting insert 100Q in contact with the first receiving surface 28A and the second receiving surface 28B. As a result, when the bolt 31A and the nut 32 are tightened, the bolt seat surface 34z and the tapered surface 105a of the first cutting insert 100P and the nut seat surface 32z and the tapered surface 105a of the second cutting insert 100Q come into close contact with each other, so that the first cutting insert 100P and the second cutting insert 100Q can be strongly pressed against the first receiving surface 28A and the second receiving surface 28B. This allows the positioning of the first cutting insert 100P and the second cutting insert 100Q to be performed with higher accuracy.

[0053] [Effects of this embodiment] According to the above-described embodiment of the holder 2 for indexable cutting tools and the indexable cutting tool 1, the first cutting insert 100P and the second cutting insert 100Q are fixed to the insert mounting seat 25A by the fixing member 30A including the bolt 31A and the nut 32. The bolt 31A is inserted through the insertion hole 105 of the first cutting insert 100P, the through hole 27 of the insert mounting seat 25A, and the insertion hole 105 of the second cutting insert 100Q, and the nut 32 is screwed to the tip of the bolt 31A. In this way, the first cutting insert 100P and the second cutting insert 100Q can be attached to the insert mounting seat 25A by one bolt 31A and nut 32. Therefore, there is no need to secure a space for arranging a plurality of bolts at the tip of the holder body 20, and the diameter of the holder body 20 and the indexable cutting tool 1 can be reduced. Furthermore, when the first cutting insert 100P and the second cutting insert 100Q are attached to the insert mounting seat 25A, the attachment work can be performed efficiently because it is only necessary to fasten one bolt 31A and one nut 32. In addition, the number of parts can be reduced, thereby reducing costs.

[0054] In this embodiment, the bolt 31A has a first male screw portion 35 into which the nut 32 can be screwed, and a second male screw portion 36 into which the female screw portion 27n of the through hole 27 can be screwed. As a result, when the first cutting insert 100P and the second cutting insert 100Q are attached to the insert mounting seat 25A, the first cutting insert 100P can be sandwiched and fixed between the first seating surface 26A and the head 34 of the bolt 31A by screwing the second male screw portion 36 into the female screw portion 27n of the through hole 27. Thereafter, the second cutting insert 100Q can be sandwiched and fixed between the second seating surface 26B and the nut 32 by screwing the nut 32 into the first male screw portion 35 formed on the tip portion of the shaft portion 33A of the bolt 31A. As a result, the first cutting insert 100P and the second cutting insert 100Q can be sequentially and individually fixed by one bolt 31A and nut 32.

[0055] In addition, in this embodiment, when the shaft portion 33A of the bolt 31A is inserted into the through hole 27 from the first side R1 to the second side R2 in the radial direction R, the first male thread portion 35 has a smaller diameter than the second male thread portion 36, so that the tip portion of the shaft portion 33A of the bolt 31A can be inserted into the through hole 27 while preventing the first male thread portion 35 from interfering with the female thread portion 27n of the through hole 27. This allows the installation work of the pair of cutting inserts 100 by the bolt 31A to be performed efficiently.

[0056] In this embodiment, the first cutting insert 100P and the second cutting insert 100Q are attached to a first side R1 and a second side R2 in the radial direction R of a plate-shaped insert mounting seat 25A that passes through the tool center axis C and extends along a plane that intersects with the radial direction R. With this, the first cutting insert 100P and the second cutting insert 100Q can be firmly fixed by fastening them with the bolt 31A and the nut 32 in a state where the insert mounting seat 25A is sandwiched between them.

[0057] In addition, in this embodiment, the tapered bolt seat 34z formed on the head 34 of the bolt 31A is brought into contact with the tapered surface 105a of the first cutting insert 100P, so that the first cutting insert 100P can be accurately positioned in the direction along the first seating surface 26A.

[0058] In addition, in this embodiment, the tapered nut seating surface 32z formed on the nut 32 is brought into contact with the tapered surface 105a of the second cutting insert 100Q, so that the second cutting insert 100Q can be accurately positioned in the direction along the second seating surface 26B.

[0059] In this embodiment, the insert mounting seat 25A has a first receiving surface 28A and a second receiving surface 28B. With this, by bringing the first cutting insert 100P into contact with the first receiving surface 28A and bringing the second cutting insert 100Q into contact with the second receiving surface 28B, the holder body 20 is attached to a processing machine and rotated to the other side in the circumferential direction T around the tool central axis C to process a workpiece, and the reaction force that the first cutting insert 100P and the second cutting insert 100Q receive from the workpiece can be firmly received by the first receiving surface 28A and the second receiving surface 28B.

[0060] [Other configurations included in the present invention] The present invention is not limited to the above-described embodiment, and the configuration may be modified within the scope of the present invention, for example as described below.

[0061] 7 shows a first modified example of the indexable cutting tool holder and indexable cutting tool described in the above embodiment. Fig. 7 is a cross-sectional view of the indexable cutting tool of the first modified example taken along line AA in Fig. 2. 7, the shaft portion 33B of the bolt 31B of the fixing member 30B has the same diameter over its entire length. An external thread 39 is provided on the outer circumferential surface of the shaft portion 33B, which can be screwed into the female thread 27m of the through hole 27 of the insert mounting seat 25B and the female threaded hole 32n of the nut 32. In other words, the female thread 27m of the through hole 27 and the female threaded hole 32n of the nut 32 have the same diameter.

[0062] In this case as well, the fixing member 30B inserts the bolt 31B through the insertion hole 105 formed in the first cutting insert 100P, the through hole 27, and the insertion hole 105 formed in the second cutting insert 100Q from the first side R1 to the second side R2 in the radial direction R. At this time, the shaft portion 33B of the bolt 31B has the male thread portion 39 screwed into the female thread portion 27m of the through hole 27 of the insert mounting seat 25B, and the nut 32 is screwed into the male thread portion 39 at the tip portion of the bolt 31B.

[0063] According to the first modification, similarly to the above embodiment, the first cutting insert 100P and the second cutting insert 100Q can be attached to the insert mounting seat 25B by one bolt 31B and a nut 32. Therefore, there is no need to secure a space for arranging a plurality of bolts 31B at the tip of the holder body 20, and the diameter of the holder body 20 and the indexable cutting tool 1 can be reduced.

[0064] In the first modified example, the through hole 27 is provided with the female thread portion 27m, and the male thread portion 39 of the bolt 31B and the female thread portion 27m are screwed together, but this is not limited to the above. The through hole 27 may not be provided with the female thread portion 27m, and the shaft portion 33B of the bolt 31B may simply be inserted into the through hole 27.

[0065] 8 shows a second modified example of the indexable cutting tool holder and indexable cutting tool described in the above embodiment. Fig. 8 is a cross-sectional view of the indexable cutting tool of the second modified example taken along line AA in Fig. 2. As shown in Figure 8, in this second modified example, a pair of cutting inserts 100B having cutting faces 108B on their first surfaces 101 may be attached to the insert mounting seat 25C by a fixing member 30C including a bolt 31C passing through a through hole 27C in the insert mounting seat 25C and a nut 32C screwed onto the tip of the bolt 31C, in the same manner as in the above embodiment.

[0066] In addition to this, for example, the bolts 31A, 31B may be inclined with respect to the insert mounting seats 25A, 25B, and the cutting insert 100 may be pressed against the first receiving surface 28A and the second receiving surface 28B by the bolt seating surface 34z and the nut seating surface 32z, respectively.

[0067] In addition, the configurations (elements) described in the above-mentioned embodiments, modifications, and notes may be combined without departing from the spirit of the present invention, and addition, omission, substitution, and other modifications of the configurations are possible. Furthermore, the present invention is not limited to the above-mentioned embodiments, but is limited only by the claims. [Explanation of symbols]

[0068] 1. Indexable cutting tools 2...Replaceable cutting tool holder 20…Holder body 25A~25C…Insert mounting seat 26A…First seating surface 26B…Second seating surface 27, 27C...Through hole 27n, 27m... Female thread 28A…First receiving surface 28B…Second receiving surface 30A~30C…Fixing parts 31A~31C…Volts 32, 32C…Nut 32z…Nut seat 33A, 33B...Shaft part 34...Head 34z…Bolt seat 35…First male thread 36…Second male thread 100, 100B...Cutting insert 100P…First cutting insert 100Q…Second cutting insert 104…Cutting edge 105...Through hole 105a...Tapered surface C…Tool center axis R: Radial direction R1: First side R2…Second side T…Circumferential direction T1: One side T2: Other side X…Tool axis direction

Claims

1. a holder body having an insert mounting seat on which a pair of cutting inserts having cutting edges can be mounted, the insert mounting seat extending in a tool axial direction along a central axis of the tool; A fixing member that detachably fixes the pair of cutting inserts to the insert mounting seats, The insert mounting seat is a first seating surface that faces a first side in a radial direction of the holder body that intersects with the tool axis direction and that comes into contact with the first cutting insert; a second seating surface facing the second radial side and contacting the second cutting insert; The insert mounting seat has a through hole penetrating in the radial direction connecting the first seating surface and the second seating surface, The fixing member is a bolt having a shaft portion that is inserted through an insertion hole formed in the first cutting insert, the through hole, and an insertion hole formed in the second cutting insert from a first side to a second side in the radial direction; A nut screwed onto the tip portion of the bolt from the second side in the radial direction. Holder for indexable cutting tools.

2. The through hole has a female screw portion formed on an inner circumferential surface of the through hole, The bolt is A first male screw portion formed at a tip end of the shaft portion and into which the nut can be screwed; A second male screw portion is formed in an intermediate portion of the shaft portion and is capable of being screwed into the female screw portion of the through hole.

2. The holder for an indexable cutting tool according to claim 1.

3. The second male thread portion has a larger diameter than the first male thread portion.

3. The holder for an indexable cutting tool according to claim 2.

4. The insert mounting seat is a plate-like member extending along a plane that passes through the tool central axis and connects the first seating surface and the second seating surface and intersects with the radial direction.

3. The holder for an indexable cutting tool according to claim 1 or 2.

5. The bolt has a head having an outer diameter larger than that of the shaft portion, The head portion has a tapered bolt seat surface that contacts a tapered surface formed at an end portion of the insertion hole of the first cutting insert.

3. The holder for an indexable cutting tool according to claim 1 or 2.

6. The nut has a tapered nut seat surface that contacts a tapered surface formed at an end of the insertion hole of the second cutting insert, 3. The holder for an indexable cutting tool according to claim 1 or 2.

7. The insert mounting seat is a first receiving surface that is formed on one side of the first seating surface in a circumferential direction about the tool center axis, faces the other side in the circumferential direction, and comes into contact with the first cutting insert; a second receiving surface formed on one side of the second seating surface in a circumferential direction about the tool center axis, facing the other side in the circumferential direction, and contacting the second cutting insert; 3. The holder for an indexable cutting tool according to claim 1 or 2.

8. A holder for an indexable cutting tool according to claim 1 or 2; A pair of cutting inserts attached to the insert mounting seats. Indexable cutting tool.

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