Cutting edge replaceable cutting tool, insert attachment mechanism, and insert holder

Abstract

To provide a cutting edge replaceable cutting tool, an insert attachment mechanism, and an insert holder capable of suppressing the occurrence of chipping and vibration of a cutting insert.SOLUTION: A cutting edge replaceable cutting tool includes: a tabular cutting insert having a front surface, a back surface, an outer peripheral surface, and a cutting edge; a tool body including an insert attachment seat comprising an attachment surface in contact with the back surface, and a receiving surface in contact with a part of the outer peripheral surface; an insert locking member having a first portion extending so as to traverse the cutting insert along a front surface of the cutting insert and a second portion extending from both ends of the first portion toward a back surface side; a tension introducing mechanism for causing the first portion to press the cutting insert against the attachment surface and the receiving surface by introducing tension into the insert locking member; and a fixing mechanism for fixing the insert locking member into which the tension is introduced.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to an indexable cutting tool, an insert attachment mechanism, and an insert holder. [Background technology]

[0002] Conventionally, as a tool body (bite holder) of an indexable cutting tool to which a cutting insert (chip) for cutting processing is detachably attached, for example, the one described in the following Patent Document 1 is known. The tool body of Patent Document 1 is provided with a bolt that presses and clamps the center of the cutting insert against the bottom surface of the V-shaped recess in order to detachably attach the cutting insert having a cutting edge. For this reason, a through hole is formed in the center of the cutting insert to allow the bolt to pass through. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2006-35390 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the case of the above-mentioned turning insert, particularly when the cutting insert is to be made smaller, the through hole through which the bolt is inserted reduces the rigidity of the cutting insert, which may result in breakage or vibration of the cutting insert during cutting.

[0005] In view of the above circumstances, one of the objects of the present invention is to provide an indexable cutting tool, an insert mounting mechanism, and an insert holder that can suppress a decrease in the rigidity of the cutting insert and suppress damage to or vibration of the cutting insert during cutting, even when the cutting insert is made smaller. [Means for solving the problem]

[0006] One embodiment of the indexable cutting tool of the present invention has a plate-shaped cutting insert having a front surface and a back surface facing in the insert axial direction along which the insert central axis extends, an outer peripheral surface facing outward in the insert radial direction perpendicular to the insert central axis, and a cutting edge arranged on a ridge portion where the front surface and the outer peripheral surface are connected, a tool body having an insert mounting seat with an attachment surface that intersects the insert central axis and contacts the back surface, and a receiving surface that faces inward in the insert radial direction and contacts a part of the outer peripheral surface, an insert locking member having a first portion extending across the cutting insert along the front surface of the cutting insert and a second portion extending from both ends of the first portion to the back surface side in the insert axial direction, a tension introduction mechanism that introduces tension into the insert locking member, thereby pressing the cutting insert against the attachment surface and the receiving surface at the first portion, and a fixing mechanism that fixes the insert locking member into which the tension has been introduced.

[0007] According to one aspect of the indexable cutting tool of the present invention, the cutting insert is fixed using an insert locking member having a first portion extending across the cutting insert along the surface of the cutting insert and a second portion extending from both ends of the first portion to the back side in the insert axial direction. The insert locking member is fixed by the fixing mechanism in a state in which tension is introduced by the tension introduction mechanism. Therefore, the cutting insert can be attached to the tool body without using a bolt. This eliminates the need to form a through hole in the cutting insert for inserting the bolt. As a result, even if the cutting insert is made smaller, the reduction in rigidity of the cutting insert can be suppressed, and the occurrence of breakage and vibration of the cutting insert during cutting can be suppressed.

[0008] In the above-described indexable cutting tool, at least the second portion of the insert locking member may be made of a wire.

[0009] In this case, since at least the second part of the insert locking member is made of wire, the cutting insert can be pressed against the mounting surface and the receiving surface by the tension introduced to the wire of the second part by the tension introduction mechanism at the first part.

[0010] In the above-described indexable cutting tool, the first portion of the insert locking member may be made of a wire continuous with the second portion.

[0011] In this case, the entire insert locking member can be formed from wire, which simplifies the structure and leads to lower costs.

[0012] In the above-described indexable cutting tool, the cutting insert may have a groove extending across the cutting insert along the surface and receiving the first portion.

[0013] In this case, by accommodating the first part made of the wire in the groove, the tension introduced into the insert locking member (wire) by the tension introduction mechanism acts on the cutting insert through the groove, allowing the cutting insert to be pressed against the mounting surface and the receiving surface.

[0014] In the above-described indexable cutting tool, the groove may be arc-shaped when viewed from the insert axial direction, with a middle portion of the groove extending in a direction away from the receiving surface relative to both end portions of the groove.

[0015] In this case, by housing the first portion of the wire in the arc-shaped groove, the stress due to the tension introduced by the tension introduction mechanism can be prevented from concentrating in a specific portion of the groove, thereby reducing wear on the wire and the groove.

[0016] In the above-mentioned indexable cutting tool, a raised portion protruding in an axial direction of the insert may be provided on the surface, and the first portion may be hooked onto the raised portion.

[0017] In this case, the cutting insert can be fixed by hanging the first portion on the raised portion, and the process required for replacing the cutting insert can be simplified compared to when the wire is housed in the groove.

[0018] In the above-described indexable cutting tool, the tension introduction mechanism may include a drum capable of winding up the wire, and a drum rotation portion that rotates the drum.

[0019] In this case, tension can be easily applied to the wire by rotating the drum around which the wire can be wound in the drum rotation section. Also, the tension applied to the wire can be easily adjusted by adjusting the amount of rotation of the drum.

[0020] In the above-mentioned indexable cutting tool, the drum may have a plurality of gear teeth arranged in a circumferential direction around the rotation axis of the drum, and the fixing mechanism may include a restraining member that is capable of restraining rotation of the drum in one direction around the rotation axis by meshing with the gear teeth, and a biasing member that biases the restraining member in a direction to mesh with the gear teeth.

[0021] In this case, the drum is rotated to introduce tension into the wire, and the gear teeth on the drum are engaged with the restraining member, thereby restricting the rotation of the drum in one direction around the rotation axis. Furthermore, the restraining member is biased in a direction in which the restraining member engages with the gear teeth by the biasing member, thereby maintaining the state in which the rotation of the drum in one direction around the rotation axis is restricted. In this way, the tension introduced into the wire can be maintained, and the cutting insert can be maintained in a state in which it is attached to the tool body.

[0022] One aspect of the insert mounting mechanism of the present invention is an insert mounting mechanism for mounting a plate-shaped cutting insert having a front surface and a back surface facing in the insert axial direction along which the insert central axis extends, an outer peripheral surface facing outward in the insert radial direction perpendicular to the insert central axis, and a cutting edge arranged on a ridge portion where the front surface and the outer peripheral surface are connected, to a tool body having an insert mounting seat equipped with an attachment surface that intersects the insert central axis and contacts the back surface, and a receiving surface that faces inward in the insert radial direction and contacts a part of the outer peripheral surface, the insert mounting mechanism comprising: an insert locking member having a first portion extending across the cutting insert along the front surface of the cutting insert and a second portion extending from both ends of the first portion to the back surface side in the insert axial direction; a tension introduction mechanism that introduces tension into the insert locking member, thereby pressing the cutting insert against the attachment surface and the receiving surface at the first portion; and a fixing mechanism that fixes the insert locking member into which the tension has been introduced.

[0023] According to one aspect of the insert attachment mechanism of the present invention, the cutting insert can be attached to the tool body without forming a through hole for inserting a bolt in the cutting insert. As a result, even if the cutting insert is made smaller, the reduction in rigidity of the cutting insert can be suppressed, and the occurrence of breakage and vibration of the cutting insert during cutting can be suppressed.

[0024] One embodiment of the insert holder of the present invention is an insert holder for a cutting tool with an indexable cutting tip to which a plate-shaped cutting insert is removably attached, the cutting insert having a front surface and a back surface facing in the insert axial direction along which the insert central axis extends, an outer peripheral surface facing outward in the insert radial direction perpendicular to the insert central axis, and a cutting edge arranged on a ridge portion where the front surface and the outer peripheral surface are connected, the insert holder having an insert mounting seat including a mounting surface that intersects the insert central axis and contacts the back surface, and a receiving surface that faces inward in the insert radial direction and contacts a part of the outer peripheral surface, an insert locking member having a first portion extending across the cutting insert along the front surface of the cutting insert and a second portion extending from both ends of the first portion to the back surface side in the insert axial direction, a tension introduction mechanism that introduces tension into the insert locking member, thereby pressing the cutting insert against the mounting surface and the receiving surface at the first portion, and a fixing mechanism that fixes the insert locking member into which the tension has been introduced.

[0025] According to one aspect of the insert holder of the present invention, the cutting insert can be attached to the tool body without forming a through hole for inserting a bolt in the cutting insert. As a result, even if the cutting insert is made smaller, the reduction in rigidity of the cutting insert can be suppressed, and the occurrence of breakage and vibration of the cutting insert during cutting can be suppressed. Effect of the Invention

[0026] According to one embodiment of the indexable cutting tool, insert mounting mechanism, and insert holder of the present invention, it is possible to suppress a decrease in the rigidity of the cutting insert, and to suppress breakage and vibration of the cutting insert during cutting. [Brief description of the drawings]

[0027] [Figure 1] 1 is a perspective view of an indexable cutting tool according to an embodiment of the present invention; [Diagram 2] FIG. 2 is a perspective view of an insert attachment mechanism of the indexable cutting tool according to one embodiment of the present invention. [Diagram 3] FIG. 2 is a plan view of an insert attachment mechanism according to one embodiment of the present invention. [Figure 4] FIG. 2 is a left side view of the insert attachment mechanism of the embodiment of the present invention. [Diagram 5] FIG. 13 is a right side view of the insert attachment mechanism of the embodiment of the present invention. [Figure 6] 1 is a perspective view showing an insert attached to an insert holder by an insert attachment mechanism of one embodiment of the present invention; [Figure 7] FIG. 11 is a perspective view of an insert mounting mechanism of an indexable cutting tool in a first modified example of an embodiment of the present invention. [Figure 8] FIG. 11 is a perspective view of an insert mounting mechanism of an indexable cutting tool in a second modified example of the embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0028] An indexable cutting tool 1 according to an embodiment of the present invention will be described with reference to the drawings. The indexable cutting tool 1 according to the present embodiment is an indexable cutting tool, and is detachably mounted on a tool rest of a machine tool such as a lathe (not shown).

[0029] 1 to 5, an indexable cutting tool 1 includes a plate-shaped cutting insert 2 and an insert holder 3. The insert holder 3 includes a tool body 30 having an insert mounting seat 33, and an insert mounting mechanism 50.

[0030] The tool body 30 extends along a tool central axis (not shown). The insert mounting seat 33 is disposed at the first end 30a of both end portions (first end 30a and second end 30b) of the tool body 30. The tool body 30 has a top surface 31a and a bottom surface facing in opposite directions, a pair of side surfaces 31b, 31c facing in opposite directions, and a tip surface 31d located at the end surface of the first end 30a.

[0031] [Direction definition] In this embodiment, the direction in which the tool central axis of the tool body 30 extends is referred to as the tool axis direction. In the tool axis direction, the direction from the second end 30b to the first end 30a of the tool body 30 is referred to as the front end side, and the direction from the first end 30a to the second end 30b is referred to as the rear end side. Among the directions perpendicular to the tool center axis, the direction in which the pair of lateral faces 31b, 31c of the tool body 30 face is called the tool width direction (left-right direction). The tool width direction corresponds to the direction in which the indexable cutting tool 1 is fed against the workpiece during cutting, i.e., the tool feed direction. Within the tool width direction, the direction from one lateral face 31b to the other lateral face 31c is called the left side, and the direction from the other lateral face 31c to one lateral face 31b is called the right side. The direction perpendicular to the tool center axis and perpendicular to the tool width direction is called the up-down direction (height direction). The up-down direction is the direction in which the top surface 31a and the bottom surface of the tool body 30 face. In the up-down direction, the direction in which the surface 21 of the cutting insert 2, which will be described later, faces is called the upper side, and the opposite direction to the direction in which the surface 21 faces is called the lower side. In this embodiment, the terms left side, right side, upper side, and lower side are simply names used to explain the relative positional relationships of each part, and the actual positional relationships, etc. may be other than those indicated by these names.

[0032] 1 to 6, the cutting insert 2 is in the shape of a plate centered on the insert central axis A, and has a pair of plate surfaces 21, 22 facing in opposite directions. One plate surface 21 of the pair of plate surfaces 21, 22 is a front surface 21, and the other plate surface 22 is a back surface 22. In this embodiment, the direction in which the insert central axis A of the cutting insert 2 extends is referred to as the insert axial direction. In the insert axial direction, the direction from the front surface 21 to the back surface 22 is referred to as the front surface 21 to back surface 22 side in the insert axial direction, or simply as the back surface 22 side in the insert axial direction. In the insert axial direction, the direction from the back surface 22 to the front surface 21 is referred to as the back surface 22 to front surface 21 side in the insert axial direction, or simply as the front surface 21 side in the insert axial direction. The direction perpendicular to the insert central axis A is called the insert radial direction. Within the insert radial direction, the direction approaching the insert central axis A is called the insert radial inner direction, and the direction away from the insert central axis A is called the insert radial outer direction. Moreover, a direction perpendicular to the insert axial direction in which the insert central axis A extends and a direction connecting two cutting edges 25 (described later) among the insert radial directions is referred to as an insert width direction.

[0033] [Tool body] 1 to 5, the tool body 30 is made of a metal such as steel. The tool body 30 has a body fixing part 31 that is fixed to a machine tool, and an insert mounting part 32 to which the cutting insert 2 is detachably mounted. The body fixing part 31 is generally prism-shaped and extends in the tool axial direction. Of the outer surfaces of the body fixing part 31, the top surface 31a faces upward. Of the outer surfaces of the tool body 30, one lateral surface 31b faces right. Of the outer surfaces of the tool body 30, the other lateral surface 31c faces left. Of the outer surfaces of the tool body 30, the tip surface 31d is flat and inclined with respect to the tool axial direction. When viewed from above, the tip surface 31d extends from the left side to the right side, inclining towards the tip side.

[0034] The insert mounting portion 32 is provided integrally with the tip side of the main body fixing portion 31. The insert mounting portion 32 has a first side surface 32a and a second side surface 32b. The first side surface 32a is provided protruding to the right side from one lateral surface 31b. The second side surface 32b is continuous with the tip surface 31d. In other words, the second side surface 32b forms a part of the tip surface 31d. The insert mounting portion 32 is in a triangular pyramid shape when viewed from above, with the first side surface 32a and the second side surface 32b gradually approaching each other toward the tip side.

[0035] The insert mounting portion 32 has an insert mounting seat 33 to which the cutting insert 2 is detachably mounted. The insert mounting seat 33 is disposed at the first end portion 30a of the tool body 30. The insert mounting seat 33 is formed below the top surface 31a at the first end portion 30a, i.e., the tip portion, of the tool body 30. As shown in Figs. 2 to 5, the insert mounting seat 33 has an upwardly facing mounting surface 33a and a pair of wall portions 33b, 33c.

[0036] The mounting surface 33a is formed below the top surface 31a. The mounting surface 33a is flat and extends in a direction intersecting the vertical direction. The mounting surface 33a in this embodiment is provided with a gradual upward inclination toward the tip side. The mounting surface 33a may extend in a direction perpendicular to the vertical direction. The rear surface 22 of the cutting insert 2 contacts the mounting surface 33a.

[0037] As shown in FIG. 2 and FIG. 3, the pair of walls 33b, 33c are provided so as to protrude upward from the mounting surface 33a. Of the pair of walls 33b, 33c, one wall 33b is provided on the right side. The one wall 33b has a receiving surface 33f facing the tip side and left side in the tool axis direction. Of the pair of walls 33b, 33c, the other wall 33c is provided on the left side. The other wall 33c has a receiving surface 33g facing the right side in the tool axis direction. When the cutting insert 2 is attached to the insert mounting seat 33, the pair of walls 33b, 33c contact a part of the outer peripheral surface 23 described later. The receiving surfaces 33f, 33g of the pair of walls 33b, 33c contact the outer peripheral surface 23 on both sides of the corner portion 2c (cutting edge 25B) on the rear end side described later.

[0038] [Cutting insert] As shown in Figs. 2 to 6, the cutting insert 2 is made of, for example, a cemented carbide alloy. In this embodiment, the cutting insert 2 is a polygonal plate, more specifically a quadrangular plate, more specifically a diamond plate. The cutting insert 2 of this embodiment is small, with a dimension in the insert width direction of, for example, 18 mm or less. The size of the cutting insert 2 is not limited to the example shown here, and may be any other size. The cutting insert 2 has a 180° rotationally symmetric shape around the insert central axis A. The cutting insert 2 is, for example, a single-sided type. The cutting insert 2 may have a reverse-symmetric shape. When the cutting insert 2 has a reverse-symmetric shape, the cutting insert 2 has a cutting edge 25 and a groove 27, which will be described later, on a front surface 21 and a back surface 22.

[0039] The cutting insert 2 has a front surface 21 , a back surface 22 , an outer circumferential surface 23 , and a cutting edge 25 . The front surface 21 and the back surface 22 face opposite sides in the sheet thickness direction of the cutting insert 2. The front surface 21 and the back surface 22 are polygonal in plan view when viewed in the sheet thickness direction. The outer peripheral surface 23 faces outward in the insert radial direction. The outer peripheral surface 23 connects the peripheries of the front surface 21 and the back surface 22. The cutting edge 25 is provided at an acute corner 2c of a rhombus formed by the polygonal front surface 21 and the back surface 22. The cutting edge 25 is provided at an intersecting ridge portion between the front surface 21 and the outer peripheral surface 23.

[0040] The groove 27 extends across the cutting insert 2 along the surface 21 of the cutting insert 2. The groove 27 extends in the insert width direction. The groove 27 is recessed downward from the surface 21. As shown in Figs. 2 and 3, in this embodiment, the groove 27 has an arc shape in which the middle portion 27c of the groove 27 extends in a direction away from the rear end receiving surfaces 33f and 33g with respect to both ends 27a and 27b in the insert width direction, that is, toward the cutting edge 25A of the tip end of the two cutting edges 25, as viewed from the insert axial direction. Such a groove 27 is also provided at a position that is 180° rotationally symmetrical about the insert central axis A.

[0041] [Insert mounting mechanism 50] As shown in FIGS. 1 to 5, the insert attachment mechanism 50 includes an insert locking member 51, a tension introduction mechanism 52, and a fixing mechanism 53. 2 to 6, the insert locking member 51 has a first portion 51a and second portions 51b, 51c extending from both ends of the first portion 51a. In the insert locking member 51 of this embodiment, the first portion 51a and the second portions 51b, 51c are entirely made of a wire 51W.

[0042] The wire diameter, etc. of the wire 51W is selected so that the wire 51W can be fixed to the mounting surface 33a with a force equal to or greater than that applied when the cutting insert 2 is fixed with a conventional bolt. For example, if the cutting insert 2 has been conventionally fixed by tightening an M3×pitch 0.5 bolt with a tightening torque of 1.0 N·m and a torque coefficient of 0.2, it is preferable to use the wire 51W made of stainless steel twisted wire with a wire diameter of about 1.5 mm or more in order to fix the cutting insert 2 with a force equal to or greater than the axial force of the bolt.

[0043] A first portion 51a of the wire 51W (insert locking member 51) extends across the cutting insert 2 along the surface 21 of the cutting insert 2. The first portion 51a is received in the groove 27. The second portions 51b, 51c extend from both ends of the first portion 51a toward the back surface 22 in the insert axial direction. As shown in Figs. 3 and 5, of the second portions 51b, 51c, the second portion 51b extends continuously from one end of the first portion 51a. The second portion 51b extends downward and toward the rear end from one end 27a of the groove 27 along the first side surface 32a of the tool body 30. An end of the second portion 51b (one end of the wire 51W) is fixed to the first side surface 32a by a fixing pin 54.

[0044] 2 to 4, of the second portions 51b and 51c, the other second portion 51c extends continuously from the other end of the first portion 51a. The second portion 51c extends downward and toward the rear end from one end 27b of the groove 27 along the second side surface 32b of the tool body 30, and extends via a guide pin 55 toward the tension introducing mechanism 52 on the rear end side.

[0045] The tension introducing mechanism 52 introduces tension to the insert locking member 51. The tension introducing mechanism 52 has a drum 52d capable of winding up the wire 51W, and a drum rotating part 52t that rotates the drum 52d. The drum 52d is provided rotatably around a rotation axis 52s perpendicular to the second side surface 32b of the tool body 30. As shown in Fig. 2 and Fig. 4, the drum 52d is formed in a disk shape when viewed from a direction perpendicular to the second side surface 32b, and has a winding portion (not shown) that winds up the other end (second portion 51c) of the wire 51W. The drum 52d has a plurality of gear teeth 52g provided on its outer circumferential surface in the circumferential direction around the rotation axis 52s of the drum 52d.

[0046] The drum rotating part 52t is a tool engagement hole provided in the center of the drum 52d. The drum rotating part 52t (tool engagement hole) is engaged with a tool such as a hexagonal wrench, so that the operator rotates the drum 52d around the rotation axis 52s and adjusts the amount of the wire 51W wound around the winding part (not shown). Such a tension introduction mechanism 52 can adjust the tension introduced to the wire 51W by rotating the drum 52d with the drum rotating part 52t. When tension is introduced into the wire 51W, the first part 51a presses the cutting insert 2 against the mounting surface 33a and the receiving surfaces 33f and 33g.

[0047] The fixing mechanism 53 fixes the wire 51W (insert locking member 51) to which tension has been introduced. The fixing mechanism 53 has a restraining member 56 and a biasing member 57. The restraining member 56 is provided on the second side surface 32b of the tool body 30 via a bracket 58. The bracket 58 integrally includes a base portion 58a provided along the second side surface 32b and a protruding portion 58b protruding from a lower end of the base portion 58a in a direction perpendicular to the second side surface 32b.

[0048] The middle part of the restraining member 56 is provided on the base part 58a so as to be rotatable around a support shaft 56s perpendicular to the second side surface 32b. One end 56a of the restraining member 56 extends toward the tip side in parallel with the second side surface 32b. The restraining member 56 has a locking claw 56t that protrudes downward from the one end 56a and engages with the gear teeth 52g of the drum 52d. The other end 56b of the restraining member 56 extends toward the rear end side in parallel with the second side surface 32b. The locking claw 56t engages with the gear teeth 52g, so that the restraining member 56 can restrain the rotation of the drum 52d around the rotation shaft 52s in one direction D1. As shown in FIG. 4, the locking claw 56t engages with the gear teeth 52g, so that the restraining member 56 restrains the rotation of the drum 52d around the rotation shaft 52s in one direction D1, which is the direction in which the wire 51W is loosened. The restraining member 56 allows the drum 52d to rotate about the rotation shaft 52s in the other direction D2, which is the direction in which the wire 51W is wound, even when the locking claws 56t are engaged with the gear teeth 52g.

[0049] The biasing member 57 is provided in a compressed state between the protruding portion 58b of the bracket 58 and the other end 56b of the restraining member 56. The biasing member 57 biases the locking claw 56t of the restraining member 56 in a direction in which the locking claw 56t meshes with the gear teeth 52g.

[0050] [Effects of this embodiment] According to the replaceable cutting tool 1, the insert mounting mechanism 50, and the insert holder 3 of the present embodiment described above, the cutting insert 2 is fixed using the insert locking member 51. The insert locking member 51 has a first portion 51a extending across the cutting insert 2 along the surface 21 of the cutting insert 2, and second portions 51b and 51c extending from both ends of the first portion 51a toward the back surface 22 in the insert axial direction. The insert locking member 51 is fixed by the fixing mechanism 53 in a state in which tension is introduced by the tension introduction mechanism 52. Therefore, the cutting insert 2 can be attached to the tool body 30 without using a bolt. This eliminates the need to form a through hole in the cutting insert 2 for inserting the bolt. As a result, even if the cutting insert 2 is made smaller, the reduction in rigidity of the cutting insert 2 can be suppressed, and the occurrence of chipping and vibration of the cutting insert 2 during cutting can be suppressed.

[0051] In addition, in this embodiment, since the second parts 51b, 51c of the insert locking member 51 are made of the wire 51W, the tension introduced into the wire 51W of the second parts 51b, 51c by the tension introduction mechanism 52 can press the cutting insert 2 against the mounting surface 33a and the receiving surfaces 33f, 33g by the first part 51a.

[0052] In this embodiment, the first portion 51a of the insert locking member 51 is made of a wire 51W that is continuous with the second portions 51b and 51c. This allows the entire insert locking member 51 to be formed from the wire 51W, which simplifies the configuration and reduces costs.

[0053] In addition, in this embodiment, by accommodating the first portion 51a consisting of the wire 51W in the groove 27, the tension introduced into the insert locking member 51 (wire 51W) by the tension introduction mechanism 52 acts on the cutting insert 2 through the groove 27, thereby pressing the cutting insert 2 against the mounting surface 33a and the receiving surfaces 33f, 33g.

[0054] In this embodiment, the groove 27 has an arc shape in which the middle portion 27c projects away from the receiving surfaces 33f, 33g with respect to both ends 27a, 27b. This allows the first portion 51a made of the wire 51W to be accommodated in the arc-shaped groove 27. This prevents the stress caused by the tension introduced by the tension introduction mechanism 52 from concentrating on a specific portion of the groove 27, thereby preventing wear on the wire 51W and the groove 27.

[0055] In the present embodiment, the drum 52d capable of winding up the wire 51W is rotated by the drum rotating part 52t, so that tension can be easily introduced to the wire 51W. Furthermore, the tension introduced to the wire 51W can be easily adjusted by adjusting the amount of rotation of the drum 52d. Therefore, the workability can be improved when the cutting insert 2 is attached to the tool body 30.

[0056] In this embodiment, the drum 52d is rotated to introduce tension into the wire 51W, and the restraining member 56 is engaged with the gear teeth 52g provided on the drum 52d, thereby restricting the rotation of the drum 52d in one direction D1 around the rotation axis 52s. Furthermore, the restraining member 56 is biased by the biasing member 57 in a direction in which the restraining member 56 engages with the gear teeth 52g, thereby maintaining the state in which the rotation of the drum 52d in one direction around the rotation axis 52s is restricted. In this way, the tension introduced into the wire 51W can be maintained, and the cutting insert 2 can be maintained in a state in which it is attached to the tool body 30.

[0057] [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.

[0058] Fig. 7 is a perspective view of an insert attachment mechanism of an indexable cutting tool in a first modified example of the above-described embodiment. In this modified example, as shown in Fig. 7, a raised portion 29 that rises upward is provided on the surface 21 of the cutting insert 2B, and a groove 27B is provided in the raised portion 29. According to the first modified example, by providing the groove 27B in the raised portion 29, it is not necessary to provide the groove 27 that is recessed downward from the surface 21 of the cutting insert 2B, and the strength of the cutting insert 2B can be further improved.

[0059] FIG. 8 is a perspective view of an insert attachment mechanism of an indexable cutting tool in a second modified example of the embodiment described above. In this modified example, as shown in FIG. 8, a protruding portion 29C protruding in the insert axial direction is provided on the surface 21 of the cutting insert 2C. The protruding portion 29C is provided only in the center of the surface 21 in the insert radial direction in the direction connecting two cutting edges 25 described below. The protruding portion 29C is also provided on the surface 21 in the entire insert width direction. In this embodiment, the first portion 51a of the wire 51W is hung on the protruding portion 29C. According to the second modified example, it is no longer necessary to provide a groove 27 on the surface 21 of the cutting insert 2C in order to hang the first portion 51a on the protruding portion 29C, and the strength of the cutting insert 2C can be further improved. In addition, since it is not necessary to accommodate the wire 51W in the groove in the fixing operation of the cutting insert 2C, the process required for replacing the cutting insert 2C can be simplified.

[0060] In the above embodiment, the wire 51W is exemplified as the insert locking member 51, but the present invention is not limited to this. For example, the first portion 51a of the insert locking member 51 may be formed in a plate shape.

[0061] In the above-described embodiment, a so-called ratchet mechanism having a restraining member 56 that meshes with the gear teeth 52g of the drum 52d was exemplified as the fixing mechanism 53, but any other configuration may be used as long as it is capable of restraining the rotation of the drum 52d.

[0062] 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]

[0063] 1. Indexable cutting tools 2, 2B, 2C...Cutting insert 3...Insert holder 21…Surface 22…Back side 23...Outer surface 25, 25A, 25B…cutting blade 27, 27B…Groove 27a, 27b...ends 27c…middle part 29, 29C…ridged part 30...Tool body 33…Insert mounting seat 33a…Mounting surface 33f, 33g…receiving surface 50...Insert mounting mechanism 51...insert locking member 51W…Wire 51a…first part 51b, 51c…Second part 52...Tension introduction mechanism 52d…Drum 52g…Gear teeth 52s…Rotation axis 52t…Drum rotating part 53…Fixing mechanism 56...Restraining member 57... Urging member A…Insert center axis

Claims

1. a plate-shaped cutting insert having a front surface and a back surface facing an insert axial direction along which a central axis of the insert extends, an outer peripheral surface facing outward in a radial direction of the insert perpendicular to the central axis of the insert, and a cutting edge disposed on a ridge line portion connecting the front surface and the outer peripheral surface; a tool body having an insert mounting seat including a mounting surface intersecting the central axis of the insert and contacting the back surface, and a receiving surface facing inward in the radial direction of the insert and contacting a part of the outer circumferential surface; an insert locking member having a first portion extending across the cutting insert along the front surface of the cutting insert, and a second portion extending from both ends of the first portion toward the back surface side in the insert axial direction; a tension introduction mechanism that introduces tension into the insert locking member to press the cutting insert against the mounting surface and the receiving surface at the first portion; and a fixing mechanism for fixing the insert locking member to which the tension has been introduced. Indexable cutting tool.

2. At least the second portion of the insert locking member is made of wire. The indexable cutting tool according to claim 1 .

3. The first portion of the insert locking member is made of a wire continuous with the second portion. The indexable cutting tool according to claim 2.

4. the cutting insert having a groove extending across the cutting insert along the surface and in which the first portion is received; The indexable cutting tool according to claim 3.

5. The groove has an arc shape in which an intermediate portion of the groove protrudes in a direction away from the receiving surface with respect to both end portions of the groove when viewed from the insert axial direction. The indexable cutting tool according to claim 4.

6. The surface is provided with a protruding portion protruding in the axial direction of the insert, The first portion is hooked onto the raised portion. The indexable cutting tool according to claim 1 .

7. The tension introducing mechanism includes: A drum on which the wire can be wound; A drum rotating unit that rotates the drum. The indexable cutting tool according to claim 2.

8. The drum has a plurality of gear teeth provided in a circumferential direction around a rotation axis of the drum, The fixing mechanism includes: a restraining member that is meshed with the gear teeth to restrain the rotation of the drum about the rotation shaft in one direction; and a biasing member that biases the restraining member in a direction in which the restraining member meshes with the gear teeth. The indexable cutting tool according to claim 7.

9. An insert mounting mechanism for mounting a plate-shaped cutting insert having a front surface and a back surface facing an insert axial direction along which an insert central axis extends, an outer peripheral surface facing outward in an insert radial direction perpendicular to the insert central axis, and a cutting edge disposed on a ridge line portion connecting the front surface and the outer peripheral surface, to a tool body having an insert mounting seat including a mounting surface intersecting the insert central axis and contacting the back surface, and a receiving surface facing inward in the insert radial direction and contacting a part of the outer peripheral surface, an insert locking member having a first portion extending across the cutting insert along the front surface of the cutting insert, and a second portion extending from both ends of the first portion toward the back surface side in the insert axial direction; a tension introduction mechanism that introduces tension into the insert locking member to press the cutting insert against the mounting surface and the receiving surface at the first portion; and a fixing mechanism for fixing the insert locking member to which the tension has been introduced. Insert mounting mechanism.

10. An insert holder for an indexable cutting tool to which a plate-shaped cutting insert is removably attached, the plate-shaped cutting insert having a front surface and a back surface facing an insert axial direction along which the insert central axis extends, an outer peripheral surface facing outward in a radial direction of the insert perpendicular to the insert central axis, and a cutting edge disposed on a ridge line portion connecting the front surface and the outer peripheral surface, a tool body having an insert mounting seat including a mounting surface intersecting the central axis of the insert and contacting the back surface, and a receiving surface facing inward in the radial direction of the insert and contacting a part of the outer circumferential surface; an insert locking member having a first portion extending across the cutting insert along the front surface of the cutting insert, and a second portion extending from both ends of the first portion toward the back surface side in the insert axial direction; a tension introduction mechanism that introduces tension into the insert locking member to press the cutting insert against the mounting surface and the receiving surface at the first portion; and a fixing mechanism for fixing the insert locking member to which the tension has been introduced. An insert holder for indexable cutting tools.

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