Cutting holders and cutting tools

Abstract

A cutting holder comprising: a holder body having, at one longitudinal-direction end thereof, an insert seat surface to which a cutting insert can be attached, a through-hole being formed in the holder body such that one part of the through-hole opens toward the insert seat surface and the other part of the through-hole opens toward the other end; and a pressing fitting having a clamp part for pressing a cutting insert against the insert seat surface, and a first engagement part, the cutting holder also comprising a screw having a second engagement part for engaging with the first engagement part, the pressing fitting being such that the clamp part is disposed at one-end side by the screw disposed within the through-hole, the pressing fitting moving along the rotational axis of the screw due to the screw rotating, and the pressing fitting disposed at the one-end side moving toward the other-end side when the screw disposed at the other-end side retracts, whereby the clamp part presses the cutting insert against the insert seat surface.

Description

[[Technical Field]]

[0001] The present invention relates to a cutting holder and a cutting tool. [[Background Art]]

[0002] A cutting tool in which a throw-away insert is clamped to a cutting holder is known (see, for example, Patent Document 1). In the cutting tool described in Patent Document 1, a female thread is formed in a hole formed from the front side of the cutting holder to which the throw-away insert is attached toward the other end side of the cutting holder. A male screw passes through a hole formed in a presser foot for clamping the throw-away insert from the front side and is screwed into the female threaded portion. In accordance with the screwing engagement between the male screw and the female screw, the presser foot is tightened to slide and press the throw-away insert, whereby the throw-away insert is fixed to the cutting holder. [[Prior Art Document]] [[Patent Document]]

[0003] [[Patent Document 1]] Japanese Utility Model Laid-open Publication No. 58-75616 [[Summary of the Invention]] [[Problem to be Solved by the Invention]]

[0004] In the cutting tool described in Patent Document 1, a thread for rotating the male screw (for example, a hexagonal hole corresponding to a hexagonal wrench) is arranged on the front side. Therefore, when a workpiece is machined using the cutting tool, chips from the workpiece may be welded to the thread of the male screw, making it difficult to remove the throw-away insert serving as a cutting insert from the cutting holder. In addition, it is necessary to form a hole in the presser foot for the male screw to pass through, and securing this hole results in an increase in the size of the presser foot. If the presser foot is increased in size, the front side of the cutting tool may also be increased in size.

[0005] This invention was made to solve the above-mentioned problems, and aims to facilitate the removal of cutting inserts from cutting tools after use, and to miniaturize cutting tools. [Means for solving the problem]

[0006] The present invention has been made to solve at least some of the above-mentioned problems and can be realized in the following forms.

[0007] (1) According to one embodiment of the present invention, a cutting holder comprises a columnar holder body having an insert seating surface at one end in the longitudinal direction to which a cutting insert can be attached, and a through hole formed therein, one end of which opens toward the insert seating surface and the other end which opens toward the other end opposite to the one end; and a retaining plate having a clamp portion for pressing the cutting insert toward the insert seating surface and a first engaging portion connected to the clamp portion, further comprising a screw having a second engaging portion that engages with the first engaging portion, wherein the retaining plate is positioned on the one end side of the screw in which the clamp portion is located within the through hole, and as the screw rotates, the retaining plate moves along the axis of rotation of the screw, and the screw positioned on the other end side pulls in the retaining plate positioned on the one end side, and as the retaining plate moves toward the other end side, the clamp portion presses the cutting insert toward the insert seating surface.

[0008] In this configuration, a retaining clip positioned at one end of the through-hole engages with a screw positioned at the other end. As the screw moves to the other end within the through-hole, the retaining clip is pulled in. When removing a cutting insert attached to the cutting holder, releasing the engagement between the retaining clip and the screw releases the pressure of the retaining clip on the cutting insert, allowing the screw to be removed separately from the other end of the through-hole. In other words, since the screw does not need to be positioned at one end, chips from the workpiece are prevented from welding to the screw, and the screw remains in a state where it can be pulled out from the through-hole. Therefore, by using a cutting holder with this configuration, the cutting insert can be easily removed from the cutting holder after tool use. Furthermore, in this configuration, the retaining clip positioned at one end of the through-hole engages with the screw positioned at the other end of the through-hole, and is then pulled in from the other end of the through-hole, fixing the cutting insert to the cutting holder. Therefore, unlike conventional methods, there is no need for space to fix the cutting insert to the cutting holder from one end with screws or the like, allowing the clamping plate to be made smaller. As a result, by using a cutting holder with this configuration, the cutting tool to which the cutting insert is attached can be made smaller, and machining can be performed with the cutting tool even in a small machining space.

[0009] (2) According to another embodiment of the present invention, a cutting holder is provided, comprising: a columnar holder body having an insert seating surface at one end in the longitudinal direction to which a cutting insert can be attached, and a through hole formed therein, one end of which opens toward the insert seating surface and the other end which opens toward the other end opposite to the one end; and a retaining plate having a clamp portion for pressing the cutting insert toward the insert seating surface and a first threaded portion connected to the clamp portion. The cutting holder further comprises a screw having a second threaded portion that engages with the first threaded portion, the through hole having a small inner diameter portion having an inner diameter smaller than the outer diameter of the screw, the clamping plate having a clamping portion positioned on one end side of the other end of the small inner diameter portion, the screw being positioned on the other end side of the small inner diameter portion, the male thread of the first and second threaded portions engaging with the female thread of the first and second threaded portions at a position further back than the other end of the small inner diameter portion when viewed from its base, the screw rotates, the clamping plate moves along the rotation axis of the screw, and the movement of the clamping plate toward the other end causes the clamping portion to press the cutting insert against the insert seating surface.

[0010] In this configuration, the cutting insert is attached to the cutting holder by screwing a retaining plate located at one end of the through hole with a screw located at the other end. Therefore, when removing the cutting insert attached to the cutting holder, the pressure of the retaining plate on the cutting insert is released by rotating the screw from the opposite end of the cutting holder, which is opposite the end facing the workpiece. In other words, since the screw is not located at one end, it is possible to suppress the welding of workpiece chips to the screw, and the screw is kept in a rotatable state. Thus, by using a cutting holder with this configuration, the cutting insert can be easily removed from the cutting holder after tool use. Furthermore, in this configuration, the retaining plate located at one end of the through hole is pulled in from the other end of the through hole by the screw located at the other end of the through hole, and the cutting insert is fixed to the cutting holder. Therefore, as in conventional methods, there is no need to form a screw hole in the retaining plate for a screw to pass through in order to fix the cutting insert to the cutting holder from one end with a screw or the like. Since there is no need to form screw holes in the clamping plate, the clamping plate can be made smaller. As a result, by using the cutting holder with this configuration, the cutting tool to which the cutting insert is attached can be made smaller, and machining can be performed with the cutting tool even in a small space for machining.

[0011] (3) In the cutting holder of the above form, the first engaging portion is a first threaded portion, and the second engaging portion is a second threaded portion that screws onto the first threaded portion. With the first threaded portion and the second threaded portion screwed together, the screw may rotate in a direction that tightens the first threaded portion and the second threaded portion, thereby pulling the retaining plate toward the other end so that the clamping portion of the retaining plate approaches the screw. In this configuration, the retaining plate and the screw are engaged by the screwing of the first threaded portion and the second threaded portion. When the screw rotates in the through hole in the direction that tightens the first and second threaded portions while the first and second threaded portions are screwed together, the clamping portion of the retaining plate moves closer to the screw. Therefore, once the position of the screw in the through hole is fixed, the rotation of the screw can pull the retaining plate towards the other end.

[0012] (4) In the cutting holder of the above form, the through hole has a third threaded portion, and a fourth threaded portion is formed on the outer surface of the screw that engages with the third threaded portion, and the screw may move toward the other end while the third threaded portion and the fourth threaded portion are engaged, thereby pulling the retaining plate toward the other end. In this configuration, the third threaded portion of the through hole and the fourth threaded portion formed on the outer surface of the screw are screwed together. Therefore, when the screw rotates in the direction that moves it toward the other end while the retaining plate and the screw are engaged, the retaining plate moves toward the other end together with the screw. As a result, the rotation of the screw can pull the retaining plate toward the other end.

[0013] (5) In the cutting holder of the above form, the through hole has a third threaded portion having a spiral shape opposite to that of the first and second threaded portions, and a fourth threaded portion is formed on the outer surface of the screw that screws into the third threaded portion, and the screw may move while pulling the retaining plate towards the other end by rotating so that it moves toward the other end while the third and fourth threaded portions are screwed into each other. In this configuration, the position of the screw relative to the holder body in which the through hole is formed is determined by the threading of the third threaded portion of the through hole with the fourth threaded portion formed on the outer circumference of the screw. The position of the retainer relative to the screw is determined by the threading of the first threaded portion of the retainer with the second threaded portion formed on one end of the screw placed in the through hole. The third threaded portion has a spiral shape opposite to that of the first and second threaded portions. Therefore, even if the screw rotates in the through hole in a direction that pulls the retainer towards the other end, the retainer, which has a clamping portion that presses the cutting insert against the insert seating surface, does not rotate in a direction that loosens the pressing force of the clamping portion. Furthermore, in this configuration, in order to fix the cutting insert to the cutting holder from one end with a screw, it is not necessary to form a screw hole in the retainer for the screw to pass through. Moreover, in this configuration, when forming the through hole in the holder body, it is not necessary to form the hole from both the one end and the other end; the third threaded portion can be formed after the through hole is formed from one end. As a result, a through-hole with a third threaded portion can be formed in the holder body with simple processing, thus simplifying the manufacturing of the cutting holder.

[0014] (6) In the cutting holder of the above form, with the first threaded portion and the second threaded portion screwed together, the screw may rotate in a direction that tightens the first threaded portion and the second threaded portion, thereby pulling the retaining plate toward the other end so that the clamping portion of the retaining plate approaches the screw. With this configuration, once the screw's position within the through-hole is fixed, the screw's rotation allows the retaining clip to be pulled towards the other end.

[0015] (7) In the cutting holder of the above form, the through hole has a third threaded portion, and a fourth threaded portion is formed on the outer surface of the screw that engages with the third threaded portion, and the screw may move toward the other end while the third threaded portion and the fourth threaded portion are engaged, thereby pulling the retaining plate toward the other end. In this configuration, when the retaining plate and the screw are screwed together, and the screw rotates in the direction that moves it toward the other end, the retaining plate moves toward the other end along with the screw. As a result, the rotation of the screw can pull the retaining plate toward the other end.

[0016] (8) In the cutting holder of the above form, the through hole has a third threaded portion having a spiral shape opposite to that of the first and second threaded portions, and a fourth threaded portion is formed on the outer surface of the screw that screws into the third threaded portion, and the screw may move while pulling the retaining plate towards the other end by rotating it so that it moves toward the other end while the third and fourth threaded portions are screwed into each other. In this configuration, the third threaded portion has a spiral shape opposite to that of the first and second threaded portions. Therefore, even if the screw rotates within the through-hole in a direction that pulls the retaining plate towards the other end, the retaining plate, which has a clamping portion that presses the cutting insert against the insert seating surface, does not rotate in a direction that loosens the pressing force of the clamping portion. Furthermore, in this configuration, when forming the through-hole in the holder body, it is not necessary to form the hole from both the one end and the other end; the third threaded portion can be formed after the through-hole is formed from one end. As a result, a through-hole with a third threaded portion can be formed in the holder body with simple processing, thus simplifying the manufacturing of the cutting holder.

[0017] (9) In the cutting holder of the above form, the through hole has a third threaded portion having a spiral shape opposite to that of the first and second threaded portions, and a fourth threaded portion is formed on the outer surface of the screw that screws into the third threaded portion, and the screw may move while pulling the retaining plate towards the other end by rotating it so that it moves toward the other end while the third and fourth threaded portions are screwed into each other. According to this configuration, the third threaded portion has a helical shape oriented in the opposite direction to that of the first threaded portion and the second threaded portion. Therefore, even if the screw rotates in the direction of drawing the presser foot toward the other end side within the through hole, the presser foot having a clamp portion that presses the cutting insert against the insert seat surface does not rotate in the direction that loosens the pressing force of the clamp portion. Furthermore, when forming the through hole in the holder body, it is not necessary to form holes from one end side and the other end side respectively; it is only required that the third threaded portion is formed after the through hole is formed from one side. As a result, the through hole having the third threaded portion can be formed in the holder body by simple processing, thereby simplifying the manufacture of the cutting holder.

[0018] (10) According to another aspect of the present invention, there is provided a cutting tool. The cutting tool comprises the cutting holder of the above aspect, and a cutting insert clamped by the cutting holder. According to this configuration, since the screw is not disposed on the one end side, welding of chips of the workpiece to the screw can be suppressed. This allows the cutting insert to be easily removed from the cutting holder after use of the tool. Furthermore, since the presser foot disposed on the one end side of the through hole is drawn in from the other end side of the through hole, there is no need to form a threaded hole in the presser foot, and the presser foot can be reduced in size. Accordingly, according to this configuration, the cutting tool can be reduced in size.

[0019] (11) In the cutting tool of the above aspect, the cutting tool may be a rotary tool. According to this configuration, the cutting holder can have a small diameter.

[0020] (12) In the cutting tool of the above aspect, the cutting tool may be a milling tool. According to this configuration, the cutting holder can have a small diameter.

[0021] The present invention can be implemented in various aspects, for example, can be implemented in the form of a cutting tool, a cutting holder, a system including these components, and the like. [BRIEF DESCRIPTION OF THE DRAWINGS]

[0022] [Figure 1] It is a schematic diagram of a cutting tool according to an embodiment of the present invention. [Figure 2] It is a schematic diagram of a cutting tool according to an embodiment of the present invention. [Figure 3] It is an explanatory diagram of a through hole. [Figure 4] It is a schematic diagram of the X-X cross section in FIG. 1. [Figure 5] It is an explanatory diagram of a cutting tool according to a second embodiment. [Figure 6] It is an explanatory diagram of a cutting tool according to the second embodiment. [Figure 7] It is an explanatory diagram of a cutting tool according to the second embodiment. [Figure 8] It is a schematic diagram of a cutting tool according to a third embodiment. [Figure 9] It is a schematic diagram of a cutting tool according to the third embodiment. [Figure 10] It is an explanatory diagram of a through hole. [Figure 11] It is a schematic diagram of the Xb-Xb cross section in FIG. 8. [Figure 12] It is an explanatory diagram of a cutting tool according to a modified example. [Figure 13] It is an explanatory diagram of a cutting tool according to a modified example. [Figure 14] It is an explanatory diagram of a cutting tool according to a modified example. MODE FOR CARRYING OUT THE INVENTION

[0023] <First Embodiment> FIG. 1 and FIG. 2 are schematic diagrams of a cutting tool 100 according to an embodiment of the present invention. The cutting tool 100 of the present embodiment is a milling tool that rotates about a central axis OL1 and performs cutting on a workpiece by means of three cutting inserts 60. In the cutting tool 100 of the present embodiment, a clamping mechanism is employed in which a presser foot 20 for fixing each cutting insert 60 to a cutting holder 50 is pulled toward the cutting holder 50 side from the opposite side (the other end side) of one end facing the workpiece, not from said one end side.

[0024] Figure 1 shows a schematic side view of the cutting tool 100. Figure 2 shows a schematic front view of the cutting tool 100 viewed from one end along the direction of the central axis OL1. As shown in Figures 1 and 2, the cutting tool 100 comprises a cutting holder 50 and three cutting inserts 60 attached to the cutting holder 50. The cutting holder 50 comprises a columnar holder body 10 extending along the central axis OL1, three retaining plates 20 that press each cutting insert 60 against the holder body 10, and three screws 30. The direction along the central axis OL1 corresponds to the longitudinal direction of the holder body 10 and the cutting tool 100. The Cartesian coordinate systems CS shown in Figures 1 and 2 are corresponding.

[0025] As shown in Figures 1 and 2, each cutting insert 60 in this embodiment has the same shape and is disc-shaped. Each cutting insert 60 is attached to the holder body 10 by being pressed against a flat insert seating surface 11 formed on the holder body 10 by a clamp portion 21 of the retaining plate 20. In other words, each cutting insert 60 is attached to the holder body 10 by being sandwiched between the clamp portion 21 and the insert seating surface 11 formed on one end along the central axis OL1. The material of the cutting insert 60 in this embodiment is a hard material such as cemented carbide, cermet, or ceramic, or a material in which a PVD (Physical Vapor Deposition) or CVD (Chemical Vapor Deposition) coating film is applied to the surface of these hard materials.

[0026] As shown in Figure 1, the holder body 10 has three through holes 12. Figure 3 is an explanatory diagram of the through holes 12. Figure 3 shows a schematic perspective view of the holder body 10. As shown in Figure 3, each through hole 12 penetrates from one end of the holder body 10 to the other end, reaching the side surface of the holder body 10. In other words, one end of the through hole 12 opens toward the insert seating surface 11, and the other end opens toward the other end.

[0027] Figure 4 is a schematic diagram of the XX cross section in Figure 1. Figure 4 shows a schematic cross section parallel to the central axis OL2 of the through hole 12. As shown in Figure 4, the through hole 12 has a large diameter portion 12A formed on one end, a large diameter portion 12C formed on the other end, and a small diameter portion (small inner diameter portion) 12B formed between the large diameter portion 12A and the large diameter portion 12C. The inner diameter of the small diameter portion 12B is relatively smaller than the inner diameter of either the large diameter portion 12A or the large diameter portion 12C.

[0028] The retaining clip 20 has a clamp portion 21 and a male threaded portion 22 (first threaded portion) connected to the clamp portion 21 and having a male thread formed thereon. As shown in Figure 4, the clamp portion 21 is located at the large diameter portion 12A on one end side of the small diameter portion 12B. The clamp portion 21 also has a clamping surface 21F that presses the cutting insert 60 against the insert seating surface 11. The clamping surface 21F is inclined toward the central axis OL2 of the through hole 12 as it moves from one end to the other end, and when the retaining clip 20 is fixed to the holder body 10, it faces the insert seating surface 11 and presses the cutting insert 60. The male threaded portion 22 is inserted through the small diameter portion 12B and extends to the large diameter portion 12C on the other end.

[0029] The screw 30 has a female threaded portion (second threaded portion) 31 in which an internal thread is formed, and a tool engagement portion 32 formed on the opposite side of the female threaded portion 31. As shown in Figure 4, the female threaded portion 31 is positioned on the other end of the larger diameter portion 12C, which is on the other end side of the smaller diameter portion 12B, with the female threaded portion 31 facing one end. The outer diameter of the screw 30 is larger than the inner diameter of the smaller diameter portion 12B. The tool engagement portion 32 is a regular hexagonal groove formed to fit, for example, a hex wrench.

[0030] As shown in Figure 4, in the cutting tool 100, the clamping plate 20 has a clamp portion 21 positioned at the large diameter portion 12A on one end of the through hole 12, and a male threaded portion 22 inserted through the small diameter portion 12B of the through hole 12 and extending to the large diameter portion 12C on the other end. Therefore, the female threaded portion 31 of the screw 30 is screwed into the inserted male threaded portion 22 at a position on the other end side of the small diameter portion 12B (the large diameter portion 12C on the other end).

[0031] With the male threaded portion 22 of the retaining plate 20 screwed into the female threaded portion 31 of the screw 30, when the tool fitted into the tool engagement portion 32 of the screw 30 rotates, the screw 30 rotates around the central axis OL2 in accordance with the rotation of the tool, while being inserted into the large diameter portion 12C on the other end. When the screw 30 rotates toward the side that tightens the male threaded portion 22 of the retaining plate 20, the screw 30 moves toward one end along the central axis OL2, and the retaining plate 20 moves toward the other end along the central axis OL2.

[0032] Because the outer diameter of the screw 30 is larger than the inner diameter of the small diameter portion 12B, when the screw 30 moves a predetermined amount toward one end, the screw 30 comes into contact with the other end of the small diameter portion 12B. Therefore, the movement of the screw 30 toward one end is restricted by the small diameter portion 12B. At the same time, when the retaining plate 20 moves a predetermined amount toward the other end, the clamping surface 21F of the clamping portion 21 comes into contact with the cutting insert 60. Therefore, the movement of the retaining plate 20 toward the other end is restricted by the cutting insert 60.

[0033] As shown in Figure 4, the insert seating surface 11 that holds the disc-shaped cutting insert 60 and the clamping surface 21F of the clamping portion 21 are inclined. Therefore, when the retaining clip 20 is moved further to the other end, the clamping surface 21F presses the cutting insert 60 against the insert seating surface 11 with even greater force.

[0034] When the screw 30 rotates in the direction that releases the male threaded portion 22 of the retaining plate 20, the retaining plate 20 moves toward one end along the central axis OL2. As the retaining plate 20 moves toward one end, the force with which the clamping surface 21F presses the cutting insert 60 against the insert seating surface 11 weakens, and the cutting insert 60 can be removed from the cutting holder 50. Furthermore, when the screw 30 rotates in the direction that releases the male threaded portion 22, the screw-in engagement between the male threaded portion 22 of the clamping portion 21 and the female threaded portion 31 of the screw 30 is released, and the retaining plate 20 and the screw 30 can be removed from the holder body 10.

[0035] As described above, the cutting holder 50 of this embodiment comprises a holder body 10 having an insert seating surface 11 and a through hole 12, a retaining plate 20 having a clamping portion 21 and a male threaded portion 22, and a screw 30 having a female threaded portion 31 that screws into the male threaded portion 22. The insert seating surface 11 is a surface on one end of the holder body 10, which is the longitudinal direction of the central axis OL1, to which the cutting insert 50 can be attached. The through hole 12 opens on one end toward the insert seating surface 11 and on the other end toward the opposite end. The through hole 12 has a small diameter portion 12B that is smaller than the outer diameter of the screw 30 and is relatively smaller than the inner diameter of either the large diameter portion 12A on one end or the large diameter portion 12C on the other end. The clamp portion 21 of the retaining plate 20 is positioned on one end of the through hole 12, and the male threaded portion 22 of the retaining plate 20 is inserted through the small diameter portion 12B of the through hole 12. The screw 30 is positioned on the other end of the through hole 12, and the female threaded portion 31 of the screw 30 is screwed into the male threaded portion 22. In this state, as the screw 30 rotates, the retaining plate 20 moves along the central axis OL2, which is the rotation axis of the screw 30. As the retaining plate 20 moves to the other end along the central axis OL2, the clamp portion 21 presses the cutting insert 60 against the insert seating surface 11. In the cutting holder 50 of this embodiment, in order to remove the cutting insert 60 attached to the cutting holder 50, the pressure of the retaining plate 20 on the cutting insert 60 is released by rotating the screw 30 from the opposite side of the one end of the cutting tool 100 facing the workpiece. In other words, since the screw 30 is not positioned on one end, it is possible to suppress the welding of chips from the workpiece to the screw 30, and the screw 30 is kept in a rotatable state. As a result, by using the cutting holder 50 of this embodiment, the cutting insert 60 can be easily removed from the cutting tool 100 after use. In addition, in the cutting holder 50 of this embodiment, the screw 30 positioned on the other end of the through hole 12 pulls the retaining plate 20 positioned on one end of the through hole 12 in from the other end of the through hole 12, thereby fixing the cutting insert 60 to the cutting holder 50.Therefore, unlike conventional designs, there is no need to form a screw hole in the retaining plate 20 for fixing the cutting insert 60 to the cutting holder 50 from one end using a screw or the like. Since there is no need to form a screw hole in the retaining plate 20, the retaining plate 20 can be made smaller. As a result, by using the cutting holder 50 of this embodiment, one end of the cutting tool 100 can be made smaller, and machining can be performed with the cutting tool 100 even in a small machining space.

[0036] Furthermore, the cutting tool 100 in this embodiment is a milling tool in which the cutting tool 100 itself rotates. Therefore, the cutting holder 50 can have a small diameter. Note that the cutting tool 100 may be a rotating tool other than a milling tool.

[0037] <Second Embodiment> Figures 5 to 7 are explanatory diagrams of the cutting tool 100a of the second embodiment. The cutting tool 100a shown in Figures 5 to 7 is a turning tool fixed to a comb-shaped tool post or the like. Figure 5 shows a schematic perspective view of the cutting tool 100a, and Figure 6 shows a schematic side view of the cutting tool 100a. Figure 7 shows a schematic diagram of the YY cross-section in Figure 6. In the second embodiment, the shape and configuration which differ from the first embodiment will be described, and the description of the shape and configuration which are the same as the first embodiment will be omitted.

[0038] As shown in Figures 5 and 6, the cutting tool 100a of the second embodiment comprises a cutting holder 50a and a cutting insert 60a attached to the cutting holder 50a. The cutting insert 60a has a substantially rhombic shape with a predetermined thickness. The cutting holder 50a comprises a columnar holder body 10a extending along the central axis OL1a, a retaining plate 20a that presses the cutting insert 60a against the holder body 10a, and a screw 30a as shown in Figure 7.

[0039] As shown in Figure 7, the holder body 10a has a through hole 12a with a central axis OL2a that is not parallel to the central axis OL1a of the holder body 10a. The through hole 12a has a large diameter portion 12Aa formed on one end, a large diameter portion 12Ca formed on the other end, and a small diameter portion 12Ba formed between the large diameter portion 12Aa and the large diameter portion 12Ca. In the second embodiment, the entire screw 30a is housed in the large diameter portion 12Ca at the other end.

[0040] The male thread portion 22a located at the other end of the retaining plate 20a, which is inserted from one end of the through hole 12a, engages with the female thread portion 31a of the screw 30a housed at the other end of the through hole 12a. As a result, the retaining plate 20a moves along the central axis OL2a in accordance with the rotation of the screw 30a around the central axis OL2a. As the retaining plate 20a moves, the force with which the clamping surface 21Fa of the clamp portion 21a of the retaining plate 20a presses the cutting insert 60a against the insert seating surface 11a of the holder body 10a changes.

[0041] The cutting tool 100a of the second embodiment is a turning tool. For example, in the comb-type tool post of a small automatic lathe, the space between tools can be very narrow. In this case, if the cutting insert 60a is made of a material that cannot form screw holes, such as ceramic, the narrow space may prevent the mounting of the clamping plate or wedge necessary to clamp the cutting insert 60a. In contrast, by using the cutting tool 100a of the second embodiment, it is possible to use a cutting insert 60a that cannot have screw holes machined, even in a comb-type tool post with limited space.

[0042] <Third Embodiment> Figures 8 and 9 are schematic diagrams of the cutting tool 100b of the third embodiment. The cutting tool 100b of the third embodiment is a milling tool that rotates around a central axis OL1b and performs cutting on the workpiece using three cutting inserts 60b, similar to the cutting tool 100 of the first embodiment. The cutting tool 100b of the third embodiment differs from the cutting tool 100 of the first embodiment in that, as shown in Figure 11 later, a female threaded portion 12D (third threaded portion) is formed in the through hole 12b of the cutting holder 50b, and an outer peripheral threaded portion (fourth threaded portion) 33 that screws into the female threaded portion 12D is formed on the outer peripheral surface of the screw 30b. In the third embodiment, the shape different from that of the cutting tool 100 of the first embodiment will be described, and the description of the shape that is the same as that of the first embodiment will be omitted.

[0043] Figure 8 shows a schematic side view of the cutting tool 100b. Figure 9 shows a schematic front view of the cutting tool 100b viewed from one end along the direction of the central axis OL1b. The cutting tool 100b comprises a cutting holder 50b and three cutting inserts 60b. As shown in Figure 8, a through hole 12b is formed in the holder body 10b. Three through holes 12b are formed in three locations corresponding to the three retaining plates 20b shown in Figure 9. Note that the Cartesian coordinate system CS shown in Figures 8 and 9 corresponds to each other.

[0044] Figure 10 is an explanatory diagram of the through-holes 12b. Figure 10 shows a schematic perspective view of the holder body 10b. As shown in Figure 3, each through-hole 12b penetrates from one end of the holder body 10b to the other end, through to the side surface of the holder body 10b, similar to the through-holes 12 in the first embodiment.

[0045] Figure 11 is a schematic diagram of the Xb-Xb cross section in Figure 8. Figure 11 shows a schematic cross section parallel to the central axis OL2b of the through hole 12b. As shown in Figure 11, a female threaded portion 12D is formed on the other end of the inner circumferential surface forming the through hole 12b. Unlike the through hole 12 of the first embodiment (Figure 4), the through hole 12b of the third embodiment does not have a large-diameter portion 12A on one end, a large-diameter portion 12C on the other end, and a small-diameter portion 12B with different inner diameters. Note that in Figure 11, there is screwing between the retaining plate 20b and the screw 30b, and screwing between the screw 30b and the female threaded portion 12D of the through hole 12b, and the irregularities of the threaded portion are shown to clarify the two screwing locations.

[0046] As shown in Figure 11, the retaining clip 20b has a clamping portion 21b having a clamping surface 21Fb, and a male threaded portion (first threaded portion) 22b located on the other end of the clamping portion 21b. The clamping surface 21Fb presses the cutting insert 60b against the insert seating surface 11b.

[0047] The screw 30b comprises a female thread portion (second thread portion) 31b that screws onto the male thread portion 22b of the retaining plate 20b, a tool engagement portion 32b formed on the opposite side of the female thread portion 31b, and an outer peripheral thread portion 33 formed on the outer peripheral surface of the screw 30b. As shown in Figure 11, the screw 30b is positioned in the through hole 12b such that the female thread portion 31b that screws onto the male thread portion 22b of the retaining plate 20b faces one end. In the third embodiment, the outer peripheral thread portion 33 is formed on the outer peripheral surface of the screw 30b on the side where the tool engagement portion 32b is formed. In other words, the outer peripheral thread portion 33 is formed on the outer peripheral surface of the screw 30b so that it is located on the other end side when the screw 30b is positioned in the through hole 12b.

[0048] In the third embodiment, the direction of the threads when screwing the outer peripheral thread portion 33 to the female thread portion 12D of the through hole 12b is the opposite direction to the direction of the threads when screwing the male thread portion 22b of the retaining plate 20b to the female thread portion 31b of the screw 30b. In other words, the female thread portion 12D of the through hole 12b has a spiral-shaped thread portion that is opposite in direction to the male thread portion 22b of the clamp surface 21Fb and the female thread portion 31b of the screw 30b.

[0049] The outer threaded portion 33 of the screw 30b is screwed into the female threaded portion 12D of the through hole 12b, thereby determining the relative position of the screw 30b with respect to the through hole 12b, i.e., the holder body 10b. In other words, the outer threaded portion 33 of the screw 30b and the female threaded portion 12D of the through hole 12b function as positioning elements that determine the position of the screw 30b with respect to the holder body 10b. When the tool fitted into the tool engagement portion 32b of the screw 30b rotates while the outer threaded portion 33 and the female threaded portion 12D are screwed together, the screw 30b rotates around the central axis OL2b in accordance with the rotation of the tool, and moves along the central axis OL2b by an amount corresponding to the amount of rotation. Therefore, with the male threaded portion 22b of the retaining plate 20b and the female threaded portion 31b of the screw 30b screwed together, the screw 30b rotates around the central axis OL2b so that it moves toward the other end, causing the screw 30b to move while pulling the retaining plate 20b toward the other end, and determining the position of the screw 30b relative to the holder body 10b.

[0050] As described above, in the cutting holder 50b of the third embodiment, a female threaded portion 12D is formed on the other end of the inner circumferential surface that forms the through hole 12b. The screw 30b has an outer circumferential threaded portion 33 formed on its outer circumferential surface. Therefore, when the screw 30b rotates in a direction that moves it toward the other end while the retaining plate 20b and the screw 30b are screwed together, the retaining plate 20b moves toward the other end together with the screw 30b. As a result, the rotation of the screw 30b can pull the retaining plate 20b toward the other end.

[0051] Furthermore, in the third embodiment, the female thread portion 12D of the through hole 12b has a spiral thread portion that is oriented in the opposite direction to the male thread portion 22b of the clamp surface 21Fb and the female thread portion 31b of the screw 30b. Therefore, even if the screw 30b rotates within the through hole 12b in a direction that pulls the retaining plate 20b towards the other end, the retaining plate 20b, which has a clamp portion 21b that presses the cutting insert 60b against the insert seating surface 11b, does not rotate in a direction that loosens the pressing force of the clamp portion 21b. In addition, in order to fix the cutting insert 60b to the cutting holder 50b from one end by a screw or the like, it is not necessary to form a screw hole in the retaining plate 20b for the screw to pass through. Moreover, in this configuration, when forming the through hole in the holder body 10b, it is not necessary to form the hole from both the one end and the other end; the female thread portion 12D can be formed after the through hole 12b is formed from one side. As a result, a through hole 12b having a female threaded portion 12D can be formed in the holder body 10b with simple processing, thus simplifying the manufacturing of the cutting holder 50b.

[0052] <Modified form of this embodiment> The present invention is not limited to the embodiments described above, and can be implemented in various forms without departing from its spirit, for example, the following modifications are also possible.

[0053] The cutting tools 100, 100a, 100b and cutting holders 50, 50a, 50b in the first and second embodiments described above are examples, and the configuration and shape of the cutting tools 100, 100a, 100b and cutting holders 50, 50a, 50b are modifiable. The number of cutting inserts 60, 60a, 60b attached to the cutting holders 50, 50a, 50b may be two or four or more. For example, when multiple cutting inserts are attached to the cutting holder, at least one cutting insert may be attached to the cutting holder with a configuration such as through holes 12, 12a, 12b, retaining plates 20, 20a, 20b, and screws 30, 30a, 30b as in the first and second embodiments described above.

[0054] The central axes OL2, OL2a, OL2b of the through holes 12, 12a, 12b may be parallel to the central axes OL1, OL1a, OL2b which are in the longitudinal direction of the holder bodies 10, 10a, 10b. The small-diameter portions 12B, 12Ba formed in the through holes 12, 12a may be formed at one end or the other end along the central axes OL2, OL2a. That is, the through holes 12, 12a, 12b should be in a form that restricts the movement of the screws 30, 30a, 30b toward one end. When large-diameter portions 12A, 12Aa are formed at one end of the through holes 12, 12a, the inner diameter of the large-diameter portions 12A, 12Aa should be determined according to the size of the retaining plates 20, 20a (e.g., clamp portions 21, 21a) that are inserted. In this case, it can be said that the inner diameters of the large-diameter sections 12A and 12Aa at one end and the small-diameter sections 12B and 12Ba are the same, or that the large-diameter sections 12A and 12Aa at one end are omitted. Therefore, "one end from the small-diameter sections 12B and 12Ba" is equivalent to "one end from the other end of the small-diameter sections 12B and 12Ba".

[0055] The screws 30, 30a, and 30b do not necessarily have tool engagement portions 32, 32b formed on the opposite side from where the female thread portions 31, 31a, and 31b are formed. For example, instead of tool engagement portions 32, 32b, a rod-shaped knob extending along the central axes OL2, OL2a, and OL2b of the screws 30, 30a, and 30b may be formed, and the screws 30, 30a, and 30b may rotate by rotating the knob. The screws 30, 30a, and 30b are deformable within a range that allows the retaining plates 20, 20a, and 20b to move along the central axes OL2, OL2a, and OL2b.

[0056] In the first embodiment described above, an example of the material of the cutting insert 60 was given, but well-known techniques can be applied to the shape and material of the cutting insert 60. Depending on the shape of the cutting inserts 60, 60a, 60b, the shapes of the insert seating surfaces 11, 11a, 11b and the clamping surfaces 21F, 21Fa, 21Fb of the clamping parts 21, 21a, 21b for attaching the cutting inserts 60, 60a, 60b to the cutting holders 50, 50a, 50b should be determined.

[0057] In the first to third embodiments described above, the retaining plates 20, 20a, and 20b are provided with male threaded portions 22, 22a, and 20b, and the screws 30, 30a, and 30b are provided with female threaded portions 31, 31a, and 31b. However, as with the cutting tools 100c and 100d described later, female threaded portions 22c and 22d may be formed on the retaining plates 20c and 20d, and male threaded portions 31c and 31d may be formed on the screws. That is, the retaining plate 20c is formed with a first threaded portion, which is one of the male and female threads, and the screw 30c is formed with a second threaded portion, which is the other of the male and female threads. The male threaded portion of the first and second threaded portions should be screwed into the female threaded portion of the first and second threaded portions at a point further inside than the other end of the small diameter portion 12Bc when viewed from its base.

[0058] In the holder body 10 of the first embodiment described above, a female threaded portion 12D (Figure 11) may be formed on the large-diameter portion 12C (Figure 4) at the other end of the through hole 12, and an outer-circumferential threaded portion 33 may be formed on the outer circumferential surface of the screw 30. In this modified example, the position of the screw 30 relative to the holder body 10 is restricted by the other end of the small-diameter portion 12B (Figure 4) and the screwing of the female threaded portion 12D of the through hole 12 with the outer-circumferential threaded portion 33. Specifically, until the screw 30 comes into contact with the other end surface of the small-diameter portion 12B, the position of the screw 30 is restricted by the screwing of the female threaded portion 12D with the outer-circumferential threaded portion 33. Once the screw 30 comes into contact with the other end surface of the small-diameter portion 12B, the position of the screw 30 is restricted by the small-diameter portion 12B. As described above, there may be multiple structures that restrict the position of the screw 30 relative to the holder body 10, such as the small diameter portion 12B and the screwing of the female thread portion 12D and the outer circumference thread portion 33.

[0059] Figure 12 is an explanatory diagram of a modified cutting tool 100c. Figure 12 shows a schematic cross-section of the cutting tool 100c at a position corresponding to the XX cross-section in Figure 1. The modified cutting tool 100c differs from the cutting tool 100 of the first embodiment (Figure 4) in that the male thread portion (second thread portion) 31c of the screw 30c is screwed into the female thread portion (first thread portion) 22c of the retaining plate 20c. The differences between the modified example shown in Figure 12 and the cutting tool 100 of the first embodiment will be explained below.

[0060] As shown in Figure 12, the modified holder body 10c has a through hole 12c that penetrates along the central axis OL2. As shown in Figure 12, the through hole 12c has the same large diameter portion 12A at one end as in the first embodiment, a large diameter portion 12Cc at the other end, and a small diameter portion (small inner diameter portion) 12Bc formed between the large diameter portion 12A and the large diameter portion 12Cc at the other end. The length of the large diameter portion 12Cc at the other end along the central axis OL2 is shorter than that of the large diameter portion 12C at the other end in the first embodiment. Conversely, the length of the small diameter portion 12Bc at the central axis OL2 is longer than that of the small diameter portion 12B in the first embodiment. In other words, in the modified cutting tool 100c, the boundary between the large diameter portion 12Cc at the other end and the small diameter portion 12Bc is shifted to the other end compared to the cutting tool 100 in the first embodiment.

[0061] As shown in Figure 12, the modified clamp 20c has a clamp portion 21 having the same shape as in the first embodiment, and a female threaded portion 22c connected to the clamp portion 21 with a female thread formed thereon. The female threaded portion 22c is inserted through the small diameter portion 12Bc. In the state shown in Figure 12, the other end of the female threaded portion 22c is located within the small diameter portion 12Bc and does not reach the large diameter portion 12Cc on the other end.

[0062] The modified screw 30c has a male threaded portion 31c that screws into the female threaded portion 22c of the retaining plate 20c, and a tool engagement portion 32 formed on the opposite side of the male threaded portion 31c. As shown in Figure 12, the outer diameter of the screw 30c on the other end where the tool engagement portion 32 is formed is smaller than the inner diameter of the larger diameter portion 12Cc on the other end, and larger than the inner diameter of the smaller diameter portion 12Bc. Therefore, the position of the end face 34 of the larger outer diameter portion on the other end is restricted by the other end face of the smaller diameter portion 12Bc. That is, the smaller diameter portion 12Bc of the through hole 12c and the end face 34 of the screw 30c function as positioning elements that determine the position of the screw 30c relative to the holder body 10c. The screw 30c can move toward one end along the central axis OL2 until the end face 34 contacts the smaller diameter portion 12Bc. In the first embodiment, the small-diameter portion 12B of the through-hole 12 and the face of one end of the screw 30 positioned in the through-hole 12 function as positioning elements that determine the position of the screw 30 relative to the holder body 10. The male threaded portion 31c protrudes from the end face 34 on the side opposite to the tool engagement portion 32. The outer diameter of the protruding male threaded portion 31c is smaller than the small-diameter portion 12Bc.

[0063] As explained above, the relationship between the female thread and the male thread may be reversed, as in the modified cutting tool 100c shown in Figure 12, where the female thread portion 22c of the screwed retainer plate 20c and the male thread portion 31c of the screw 30c are screwed together. In the cutting tool 100c, the female thread portion 22c of the retainer plate 20c and the male thread portion 31c of the screw 30c are engaged by screwing. When the screw 30c rotates in the through hole 12c in a direction that tightens the female thread portion 22c and the male thread portion 31c while the female thread portion 22c and the male thread portion 31c are screwed together, the clamp portion 21 of the retainer plate 20c moves closer to the screw 30c. Therefore, when the position of the screw 30c in the through hole 12c is fixed by the small diameter portion 12Bb, the rotation of the screw 30c can pull the retainer plate 20c toward the other end.

[0064] Figure 13 is an explanatory diagram of a modified cutting tool 100d. Figure 13 shows a schematic cross-section of the cutting tool 100d at a position corresponding to the Xb-Xb cross-section in Figure 8. The modified cutting tool 100d differs from the cutting tool 100b of the third embodiment (Figure 11) in that the male thread portion (second thread portion) 31d of the screw 30d is screwed into the female thread portion (first thread portion) 22d of the retaining plate 20d. The differences between the modified example shown in Figure 13 and the cutting tool 100b of the third embodiment will be explained below.

[0065] As shown in Figure 13, the modified retainer 20d has a clamp portion 21d having a clamping surface 21Fd that presses the cutting insert 60b against the insert seating surface 11b, and a female thread portion 22d connected to the clamp portion 21d with a female thread formed thereon. In order to form the female thread portion 22d on the other end of the retainer 20d, the shape of the clamp portion 21d connected to the female thread portion 22d is different from that of the clamp portion 21b in the third embodiment.

[0066] The modified screw 30d has a male threaded portion 31d that screws into the female threaded portion 22d of the retaining plate 20d, and a tool engaging portion 32b formed on the opposite side of the male threaded portion 31d. In the modified cutting tool 100d, the orientation of the threads when the outer threaded portion 33 is screwed into the female threaded portion 12D of the through hole 12b is the opposite orientation of the threads when the female threaded portion 22d of the retaining plate 20d is screwed into the male threaded portion 31d of the screw 30d.

[0067] As explained above, the relationship between the female thread and the male thread may be reversed, as in the modified cutting tool 100d shown in Figure 13, where the female thread portion 22d of the screwed retaining plate 20d and the male thread portion 31d of the screw 30d are reversed. In the cutting tool 100b of the third embodiment and the modified cutting tool 100d, the direction of the threads in the screwing of the retaining plates 20b, 20d and the screws 30b, 30d and the screwing of the through holes 12b of the holder body 10b, 10d and the screws 30b, 30d were opposite, but they do not need to be opposite and may be in the same direction.

[0068] Figure 14 is an explanatory diagram of a modified cutting tool 100e. Figure 14 shows a schematic cross-section of the cutting tool 100e at a position corresponding to the Xb-Xb cross-section in Figure 8. The modified cutting tool 100e differs from the cutting tool 100b of the third embodiment (Figure 11) in that the retaining plate 20e and the screw 30e are fixed by engagement by shape rather than by screwing with the threaded portion. The differences between the modified example shown in Figure 14 and the cutting tool 100b of the third embodiment will be explained below.

[0069] As shown in Figure 14, the modified clamp 20e has a clamp portion 21d that is the same shape as the modified cutting tool 100d (Figure 13), and recesses (first engaging portions) 23, 24 formed on the opposite side of the clamp portion 21d. In other words, the recesses 23, 24 are connected to the clamp portion 21d. The recesses 23, 24 consist of a one-end recess 23 which has a predetermined length along the central axis OL2b and is a circular space in cross-section, and a small-diameter portion 24 which penetrates and connects the one-end recess 23 and the surface of the other end of the clamp 20e. The small-diameter portion 24 is a through hole with a circular cross-section centered on the central axis OL2b. The cross-section of the small-diameter portion 24 is smaller than the cross-section of the one-end recess 23.

[0070] The modified screw 30e has an outer threaded portion 33, a tool engagement portion 32b, and protrusions (second engagement portions) 35, 36 formed on one end opposite the tool engagement portion 32b. The protrusions 35, 36 have a disc-shaped flange portion 36 formed on the tip side and a connecting portion 35. As shown in Figure 14, the connecting portion 35 connects the other end of the screw 30e, where the outer threaded portion 33 and the tool engagement portion 32b are formed, to the flange portion 36. The connecting portion 35 has a cylindrical shape with a circular cross-section extending along the central axis OL2b. The shape of the flange portion 36 is the same as the one-end recess 23 of the retaining plate 20e. Also, the diameter of the cross-section of the connecting portion 35 is the same as the diameter of the small-diameter portion 24 of the retaining plate 20e. Furthermore, the length of the connecting portion 35 along the central axis OL2b is longer than the length of the small-diameter portion 24 of the retaining plate 20e. Therefore, as shown in Figure 14, the recesses 23 and 24 formed on the other end of the retaining plate 20e engage with the protrusions 35 and 36 formed on one end of the screw 30e. When the recesses 23 and 24 and the protrusions 35 and 36 engage, the retaining plate 20e and the screw 30e can move together along the central axis OL2b.

[0071] In the modified cutting tool 100e, the engagement between the retaining plate 20e and the screw 30e can be released. Therefore, when fixing the cutting insert 60b to the holder body 10b, first, the screw 30e is inserted from the other end of the through hole 12b and moves to the one end by rotating around the central axis OL2b. Then, the retaining plate 20e is inserted from the one end of the through hole 12b, and the recesses 23, 24 of the retaining plate 20e engage with the protrusions 35, 36 of the screw 30e that were inserted from the other end of the through hole 12b. As the retaining plate 20e and the screw 30e move to the other end along the central axis OL2b after engagement, the clamp portion 21d of the retaining plate 20e presses the cutting insert 60b against the insert seating surface 11b. This fixes the cutting insert 60b to the holder body 10b.

[0072] In the modified cutting tool 100e, the retaining clip 20d has a clamp portion 21d and recesses 23 and 24 connected to the clamp portion 21d. The screw 30d also has protrusions 35 and 36 that engage with the recesses 23 and 24. Therefore, in the modified cutting tool 100e, the retaining clip 20e located at one end of the through hole 12b engages with the screw 30e located at the other end. As a result, the screw 30e moves to the other end within the through hole 12b, thereby pulling the retaining clip 20e to the other end. When removing the cutting insert 60b attached to the cutting holder 50e, releasing the engagement between the retaining clip 20e and the screw 30e releases the pressure of the retaining clip 20e on the cutting insert 60b. The screw 30e can also be removed from the other end of the through hole 12b separately from the retaining clip 20e. In other words, since the screw 30e does not need to be positioned on one end, it is possible to suppress the welding of chips from the workpiece to the screw 30e, and it remains in a state where it can be pulled out from the through hole 12b. Therefore, by using the modified cutting holder 50e, the cutting insert 60b can be easily removed from the cutting holder 50e after the tool has been used. In addition, in this modified version, the retaining plate 20e positioned on one end of the through hole 12b engages with the screw 30e positioned on the other end of the through hole 12b, and then is pulled in from the other end of the through hole 12b, fixing the cutting insert 60b to the cutting holder 50e. Therefore, as in the conventional version, there is no need for space to fix the cutting insert 60b to the cutting holder 50e from one end with a screw or the like, so the retaining plate 20e can be made smaller. As a result, by using the modified cutting holder 50e, the cutting tool 100e to which the cutting insert 60b is attached can be made smaller, and machining can be performed with the cutting tool 100e even if the space for machining is small.

[0073] In the modified cutting tool 100e, the engagement between the recesses 23 and 24 of the retainer plate 20e and the protrusions 35 and 36 of the screw 30e was described as an example of a shape that engages the retainer plate 20e and the screw 30e. However, the engagement shape can be modified within the scope of known technology. For example, protrusions may be formed in place of the recesses 23 and 24 that engage with the retainer plate 20e, and recesses may be formed in place of the protrusions 35 and 36 on the screw 30e to engage with the protrusions formed on the retainer plate 20e. The protrusions and recesses that engage the retainer plate 20e and the screw 30e can be easily formed by cutting or other processes. Furthermore, in the cutting tool 100b of the third embodiment and the modified cutting tools 100d and 100e, an example of an outer peripheral threaded portion 33 formed on the outer peripheral surface of the screw 30b, 30d, and 30e was described. However, the position of the outer peripheral threaded portion 33 formed on the screw 30b, 30d, and 30e can be modified. The outer threaded portion 33 may be formed so as to be located on one end side when the screws 30b, 30d, and 30e are inserted into the through hole 12b. The position of the outer threaded portion 33 can be appropriately determined by the position of the female threaded portion 12D formed in the through hole 12b.

[0074] It is preferable that either the engagement between the retaining plate 20 and the screw 30, or the positioning of the screw 30 relative to the holder body 10, is configured by screw threading. For example, in the first embodiment (Figure 4), the retaining plate 20 and the screw 30 are screwed together, in the third embodiment (Figure 11), the engagement and positioning mechanism between the retaining plate 20b and the screw 30b are screwed together, and in the modified cutting tool 100e (Figure 14), the positioning mechanism is screwed together. The presence of such screw threading allows the clamping force 21 of the screw 30 presses the insert 60 against the insert seating surface 11 to be adjusted according to the amount of rotation of the screw 30.

[0075] The embodiments of this specification have been described above based on the embodiments and modifications described above. The embodiments described above are for the purpose of facilitating understanding of this specification and do not limit it. This specification may be modified and improved without departing from its spirit and the scope of the claims, and equivalents thereof are included in this specification. Furthermore, any technical features that are not described as essential in this specification may be deleted as appropriate.

[0076] The present invention can also be realized in the following forms. [Application Example 1] A columnar holder body having an insert seating surface at one end in the longitudinal direction to which a cutting insert can be attached, and a through hole formed therein that opens toward the insert seating surface on one end and toward the other end opposite to the one end, A retaining plate having a clamp portion for pressing the cutting insert against the insert seating surface and a first engaging portion connected to the clamp portion, A cutting holder equipped with, Furthermore, the screw comprises a second engaging portion that engages with the first engaging portion, The retaining plate is positioned on one end side of the screw, with the clamp portion located within the through hole. As the screw rotates, the retaining plate moves along the axis of rotation of the screw, and the screw positioned at the other end pulls in the retaining plate positioned at one end. A cutting holder characterized in that the clamp portion presses the cutting insert against the insert seating surface as the retaining plate moves to the other end. [Application Example 2] A columnar holder body having an insert seating surface at one end in the longitudinal direction to which a cutting insert can be attached, and a through hole formed therein that opens toward the insert seating surface on one end and toward the other end opposite to the one end, A retaining plate having a clamp portion for pressing the cutting insert against the insert seating surface and a first threaded portion connected to the clamp portion, A cutting holder equipped with, Furthermore, the screw comprises a second threaded portion that engages with the first threaded portion, The through hole has a small inner diameter portion having an inner diameter smaller than the outer diameter of the screw. The retaining plate is positioned such that the clamp portion is located on one end side of the other end of the small inner diameter portion. The screw is positioned on the other end side of the small inner diameter portion, The male thread of the first and second threaded portions is screwed into the female thread of the first and second threaded portions at a point further inside than the other end of the small inner diameter portion when viewed from its own base. As the screw rotates, the retaining plate moves along the axis of rotation of the screw. A cutting holder characterized in that the clamp portion presses the cutting insert against the insert seating surface as the retaining plate moves to the other end. [Application Example 3] A cutting holder as described in Application Example 1 or Application Example 2, The first engaging portion is a first threaded portion, The second engaging portion is a second threaded portion that screws into the first threaded portion, A cutting holder characterized in that, with the first threaded portion and the second threaded portion screwed together, the screw rotates in a direction that tightens the first threaded portion and the second threaded portion, thereby pulling the retaining plate toward the other end so that the clamping portion of the retaining plate approaches the screw. [Application Example 4] A cutting holder described in any one of Application Examples 1 to 3, The aforementioned through hole has a third threaded portion, A fourth threaded portion is formed on the outer circumferential surface of the screw, which engages with the third threaded portion. The cutting holder is characterized in that the screw rotates so as to move toward the other end while the third threaded portion and the fourth threaded portion are screwed together, thereby pulling the retaining plate toward the other end. [Application Example 5] A cutting holder described in any one of the application examples 1 to 4, The through hole has a third threaded portion having a spiral shape opposite to that of the first and second threaded portions. A fourth threaded portion is formed on the outer circumferential surface of the screw, which engages with the third threaded portion. The cutting holder is characterized in that the screw rotates so as to move toward the other end while the third threaded portion and the fourth threaded portion are screwed together, thereby pulling the retaining plate toward the other end. [Application Example 6] A cutting holder described in any one of Application Examples 1 to 5, A cutting holder characterized in that, with the first threaded portion and the second threaded portion screwed together, the screw rotates in a direction that tightens the first threaded portion and the second threaded portion, thereby pulling the retaining plate toward the other end so that the clamping portion of the retaining plate approaches the screw. [Application Example 7] A cutting holder described in any one of the application examples 1 to 6, The aforementioned through hole has a third threaded portion, A fourth threaded portion is formed on the outer circumferential surface of the screw, which engages with the third threaded portion. The cutting holder is characterized in that the screw rotates so as to move toward the other end while the third threaded portion and the fourth threaded portion are screwed together, thereby pulling the retaining plate toward the other end. [Application Example 8] A cutting holder described in any one of the application examples 1 to 7, The through hole has a third threaded portion having a spiral shape opposite to that of the first and second threaded portions. A fourth threaded portion is formed on the outer circumferential surface of the screw, which engages with the third threaded portion. The cutting holder is characterized in that the screw rotates so as to move toward the other end while the third threaded portion and the fourth threaded portion are screwed together, thereby pulling the retaining plate toward the other end. [Application Example 9] A cutting holder described in any one of the application examples 1 to 8, The through hole has a third threaded portion having a spiral shape opposite to that of the first and second threaded portions. A fourth threaded portion is formed on the outer circumferential surface of the screw, which engages with the third threaded portion. The cutting holder is characterized in that the screw rotates so as to move toward the other end while the third threaded portion and the fourth threaded portion are screwed together, thereby pulling the retaining plate toward the other end. [Application Example 10] A cutting tool, A cutting holder described in any one of the application examples 1 to 9, A cutting insert clamped by the cutting holder, A cutting tool characterized by having the following features. [Application Example 11] A cutting tool described in any one of the application examples 1 to 10, The cutting tool is characterized in that it is a rotary tool. [Application Example 12] A cutting tool described in any one of the application examples from 1 to 11, The cutting tool is characterized in that it is a milling tool. [Explanation of Symbols]

[0077] 10, 10a, 10b, 10c... Holder body 11, 11a, 11b... Insert seat 12,12a,12b,12c...Through hole 12A, 12Aa... Large diameter section on one end 12B, 12Ba, 12Bc…Small diameter part (small inner diameter part) 12C, 12Ca, 12Cc... Large diameter section on the other end 20, 20a, 20b, 20c, 20d, 20e... retaining clips 21, 21a, 21b, 21d... Clamp section 21F, 21Fa, 21Fb, 21Fd... Clamping surface 22, 22a, 22b... Male threaded portion (first threaded portion) 22c, 22d... Female thread section (first thread section) 23... One-end recess (first engagement portion) 24…Small diameter part (first engagement part) 30, 30a, 30b, 30c, 30d, 30e… Screw 31, 31a, 31b... Female thread section (second thread section) 31c, 31d... Male threaded section (second threaded section) 32,32b...Tool engagement part 33... Outer circumference threaded section (4th threaded section) 34…End face 35…Connecting part (second engaging part) 36…Flange section (second engagement section) 50, 50a, 50e… Cutting holders 60, 60a, 60b… Cutting inserts 100,100a,100b,100c,100d,100e...Cutting tools CS… Cartesian coordinate system OL1, OL1a... Central axis of the holder body OL2, OL2a, OL2b... Central axis of the through hole

Claims

1. A columnar holder body having an insert seating surface at one end in the longitudinal direction to which a cutting insert can be attached, and a through hole formed therein that opens toward the insert seating surface on one end and toward the other end opposite to the one end, A retaining plate having a clamp portion positioned at one end of the through hole and pressing the cutting insert against the insert seating surface, and a first engaging portion connected to the clamp portion and positioned at the other end of the through hole, A cutting holder equipped with, Furthermore, the screw is provided with a second engaging portion that engages with the first engaging portion, The retaining plate is positioned on one end side of the screw, with the clamp portion located within the through hole. As the screw rotates, the retaining plate moves along the axis of rotation of the screw, and the screw positioned at the other end pulls in the retaining plate positioned at one end. A cutting holder characterized in that the clamp portion presses the cutting insert against the insert seating surface as the retaining plate moves to the other end.

2. A columnar holder body having an insert seating surface at one end in the longitudinal direction to which a cutting insert can be attached, and a through hole formed therein that opens toward the insert seating surface on one end and toward the other end opposite to the one end, A retaining plate having a clamp portion for pressing the cutting insert against the insert seating surface and a first threaded portion connected to the clamp portion, A cutting holder equipped with, Furthermore, it is equipped with a screw having a second threaded portion that engages with the first threaded portion, The through hole has a small inner diameter portion having an inner diameter smaller than the outer diameter of the screw. The retaining plate is positioned such that the clamp portion is located on one end side of the other end of the small inner diameter portion. The screw is positioned on the other end side of the small inner diameter portion, The screw and the other end of the small inner diameter portion come into contact, thereby restricting the movement of the screw toward the one end. The male thread of the first and second threaded portions is screwed into the female thread of the first and second threaded portions at a point further inside than the other end of the small inner diameter portion when viewed from its own base. As the screw rotates, the retaining plate moves along the axis of rotation of the screw. A cutting holder characterized in that the clamp portion presses the cutting insert against the insert seating surface as the retaining plate moves to the other end.

3. A cutting holder according to claim 1, The first engaging portion is a first threaded portion, The second engaging portion is a second threaded portion that screws into the first threaded portion, A cutting holder characterized in that, with the first threaded portion and the second threaded portion screwed together, the screw rotates in a direction that tightens the first threaded portion and the second threaded portion, thereby pulling the retaining plate toward the other end so that the clamping portion of the retaining plate approaches the screw.

4. A cutting holder according to claim 1, The through hole has a third threaded portion, A fourth threaded portion is formed on the outer circumferential surface of the screw, which engages with the third threaded portion. The cutting holder is characterized in that the screw rotates so as to move toward the other end while the third threaded portion and the fourth threaded portion are screwed together, thereby pulling the retaining plate toward the other end.

5. A cutting holder according to claim 3, The through hole has a third threaded portion having a spiral shape opposite to that of the first and second threaded portions. A fourth threaded portion is formed on the outer circumferential surface of the screw, which engages with the third threaded portion. The cutting holder is characterized in that the screw rotates so as to move toward the other end while the third threaded portion and the fourth threaded portion are screwed together, thereby pulling the retaining plate toward the other end.

6. A cutting holder according to claim 2, A cutting holder characterized in that, with the first threaded portion and the second threaded portion screwed together, the screw rotates in a direction that tightens the first threaded portion and the second threaded portion, thereby pulling the retaining plate toward the other end so that the clamping portion of the retaining plate approaches the screw.

7. A cutting tool, A cutting holder according to any one of claims 1 to 6, A cutting insert clamped by the cutting holder, A cutting tool characterized by having the following features.

8. A cutting tool according to claim 7, The cutting tool is characterized in that it is a rotary tool.

9. A cutting tool according to claim 8, The cutting tool is characterized in that it is a milling tool.

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