Tool holder adapter

Abstract

Provided is a tool holder adapter capable of reducing a work load for adjusting the direction of the axis of a cutting tool.　A tool holder adapter according to the present disclosure comprises: a body part that can be mounted to a tool attachment part of a tool rest and to which a tool holder can be attached while in a state of being mounted to the tool attachment part; and an adjustment mechanism that adjusts the direction of the axis of a cutting tool attached to the tool holder by rotating the body part attached to the tool attachment part.

Description

Tool holder adapter

[0001] The present disclosure relates to a tool holder adapter for attaching a tool holder to a tool rest.

[0002] In machine tools such as NC lathes, tool holders are attached to multiple tool mounting portions provided along the outer periphery of a tool post, and cutting tools attached to each tool holder are used to machine a workpiece. To accurately machine a workpiece, it is preferable that the axis of the cutting tool is parallel to the central axis of the workpiece. In Patent Document 1 listed below, the orientation of the axis of the cutting tool is adjusted using an angle adjustment mechanism provided in the tool holder.

[0003] Japanese Patent Application Laid-Open No. 2021-084203

[0004] In the technology disclosed in Patent Document 1, when changing the tool holder attached to the tool attachment part, it is necessary to adjust the axial orientation of the cutting tool by operating the angle adjustment mechanism each time the tool holder is changed, which may increase the workload of adjusting the axial orientation of the cutting tool.

[0005] The present disclosure has been made in view of the above-mentioned problems, and aims to provide a tool holder adapter that can reduce the workload of adjusting the axial orientation of a cutting tool.

[0006] In order to solve the above problems, this specification discloses a tool holder adapter that includes a main body that can be attached to a tool mounting portion of a tool post and to which a tool holder can be attached while attached to the tool mounting portion, and an adjustment mechanism that adjusts the axial orientation of a cutting tool attached to the tool holder by rotating the main body that is attached to the tool mounting portion.

[0007] According to the tool holder adapter of the present disclosure, the axis orientation of the cutting tool can be adjusted by rotating the main body using the adjustment mechanism. This eliminates the need to adjust the axis orientation of the cutting tool every time a tool holder attached to the tool attachment part is changed, thereby reducing the workload of adjusting the axis orientation of the cutting tool.

[0008] 1 is a perspective view showing a state in which a tool 12 is attached to a tool rest 11 of a machine tool according to the present embodiment. It is a perspective view of the tool rest 11 as seen from the front side, and is an exploded perspective view of the tool rest 11 with a tool holder adapter 13 removed. It is a partially enlarged view of FIG. 1. It is a plan view of the tool holder adapter 13. It is a cross-sectional view of the tool holder adapter 13. It is a cross-sectional view of a tool holder 61 of a type of tool 12 different from that in FIG. 1 attached to a tool attachment portion 21. It is a diagram showing an operation of checking the rotational position of the adapter 13.

[0009] An embodiment of a tool holder adapter according to the present disclosure will be described below with reference to the drawings. Fig. 1 is a perspective view showing a state in which a tool 12 is attached to a tool rest 11 of a machine tool. As shown in Fig. 1, the tool 12 is attached to the tool rest 11 via a tool holder adapter (hereinafter referred to as "adapter") 13.

[0010] The tool rest 11 has, for example, a substantially dodecagonal prism shape. As shown in FIGS. 1 and 2 , tool mounting portions 21 to which adapters 13 can be attached are provided on twelve side surfaces of the tool rest 11. FIG. 1 shows, for example, a state in which only one tool 12 is attached to the adapter 13 and the tool 12 is positioned at an index position for indexing a cutting tool to be used in machining a workpiece. The tool rest 11 is rotatably supported by a shaft 14 shown in FIG. 1 . A machine tool including the tool rest 11 rotates the tool rest 11 about a rotation axis 15 by driving a drive source such as a servo motor to rotate a quill inside the shaft 14, thereby changing the cutting tool at the index position. In the following description, as shown in FIG. 1 , the direction parallel to the rotation axis 15 is referred to as the Z-axis direction, the direction perpendicular to the Z-axis direction and along the radial direction of the tool rest 11 is referred to as the X-axis direction, and the direction perpendicular to both the X-axis direction and the Z-axis direction is referred to as the Y-axis direction. In addition, the shaft 14 side in the Z-axis direction will be referred to as the base end side, and the front (workpiece) side of the tool post 11 will be referred to as the tip end side. In addition, the following description will be based on the directions when the tool 12 and adapter 13 are attached to the tool attachment portion 21.

[0011] 1 to 5, a mounting surface 22 is formed on each of the multiple tool mounting portions 21. The mounting surface 22 is a substantially square plane parallel to the Y-axis direction and the Z-axis direction, and forms the outer peripheral surface of the tool post 11. Therefore, the tool post 11 has 12 substantially square outer peripheral surfaces. The side of the mounting surface 22 along the Y-axis direction and the side along the Z-axis direction are substantially coincident with each other.

[0012] A first insertion hole 23 is formed in the center of each tool mounting portion 21. The first insertion hole 23 is a hole formed parallel to the X-axis direction and has a circular cross section. The tool mounting portion 21 indexed (positioned) at the indexed position among the multiple tool mounting portions 21 has a drive shaft 71 (see FIG. 5 ), which will be described later, positioned more inwardly than the first insertion hole 23 in the X-axis direction (radial direction). Each of the multiple tool mounting portions 21 also has a threaded portion 25 having a female thread. For example, four threaded portions 25 are formed surrounding the first insertion hole 23, and are positioned to avoid a threaded portion 47 for attaching a tool 12 to the adapter 13, which will be described later.

[0013] The adapter 13 includes a main body 31 and an adjustment mechanism 32 (see FIG. 4 ). The main body 31 is a metal member having a thin, approximately rectangular parallelepiped shape in the X-axis direction. The width of the main body 31 in the Y-axis direction and the Z-axis direction is approximately the same as the length of each side of the mounting surface 22 of the tool mounting portion 21. Therefore, the main body 31 has a substantially square shape in the plan view shown in FIG. 4 . The main body 31 has four through holes 35 formed therethrough in the X-axis direction. A second insertion hole 37 with a circular cross section is also formed in the center of the main body 31. Each of the four through holes 35 is formed to correspond to the position of each of the four threaded portions 25 of the tool mounting portion 21 and is sized to allow the first screwing member 17 to be inserted therein. Therefore, the four through holes 35 are formed to surround the second insertion hole 37. In the adapter 13, the first screwing member 17 is inserted into each of the four through holes 35 from the outside in the X-axis direction. The adapter 13 is fixed to the tool attachment portion 21 by threading each of the four inserted first threaded members 17 into each of the four threaded portions 25. The first threaded members 17 are, for example, bolts. Note that the threaded members of the present disclosure are not limited to bolts and may be other threadable members such as screws. The same applies to other threaded members such as adjustment bolts 53, 54 and second threaded members 63, which will be described later.

[0014] The second insertion hole 37 is a hole with a circular cross section that penetrates the main body 31 in the X-axis direction. The inner diameter of the second insertion hole 37 is larger than the inner diameter of the through-hole 35. As shown in FIG. 5 , the inner diameter of the second insertion hole 37 is, for example, the same length as the inner diameter of the first insertion hole 23. The first insertion hole 23 also has an attachment-side recess 27. The attachment-side recess 27 is a recess with a circular cross section that is formed at a position outside the first insertion hole 23 in the X-axis direction and recessed from the outside toward the inside in the X-axis direction. The inner diameter of the attachment-side recess 27 is longer than the inner diameter of the first insertion hole 23. Therefore, the opening (outer) end of the first insertion hole 23 is connected to the attachment-side recess 27 and expands outward at the portion where the attachment-side recess 27 is formed.

[0015] Similarly, the main body 31 is formed with an adapter-side recess 38 having a circular cross section. The adapter-side recess 38 is formed on an inner surface 39 that is the inside of the main body 31 in the X-axis direction (radial direction), at a position that is the inside of the second insertion hole 37. The adapter-side recess 38 is recessed from the inner surface 39 toward the outside in the X-axis direction (inward with respect to the main body 31). The inner diameter of the adapter-side recess 38 is the same length as the inner diameter of the attachment-side recess 27. Therefore, the inner diameter of the adapter-side recess 38 is longer than the inner diameter of the second insertion hole 37. The inner end of the second insertion hole 37 is connected to the adapter-side recess 38 and flares outward at the portion where the adapter-side recess 38 is formed.

[0016] The main body 31 is attached to the tool attachment portion 21 with its inner surface 39 in surface contact with the attachment surface 22. The adapter-side recess 38 is connected to the attachment portion-side recess 27 and forms a cylindrical hole along an axial direction parallel to the X-axis direction. The main body 31 is rotatably attached to the tool attachment portion 21 by inserting an annular ring 33 (see FIG. 2 ) into both the attachment portion-side recess 27 and the adapter-side recess 38. The ring 33 is an annular metal member inserted into the adapter-side recess 38 and the attachment portion-side recess 27 and fixed in position. In other words, the inner diameters of the attachment portion-side recess 27 and the adapter-side recess 38 are slightly longer than the outer diameter of the ring 33, and the ring 33 is fitted into the cylindrical hole formed by the two recesses. For example, half of the inner side of the ring 33 in the X-axis direction is inserted into the attachment portion-side recess 27, and the other half is inserted into the adapter-side recess 38. When the ring 33 is inserted into both the mounting portion side recess 27 and the adapter side recess 38 and the adapter 13 is attached to the tool mounting portion 21, the center of the mounting portion side recess 27 coincides with the center of the adapter side recess 38 when viewed in a plane (viewed in the X-axis direction) of the main body 31.

[0017] The centers of the second insertion hole 37, the adapter-side recess 38, the attachment portion-side recess 27, and the first insertion hole 23 are all located at the same position in a plan view of the main body 31, and are located on the rotation axis 51 shown in FIG. 5. This rotation axis 51 is the rotation axis of the drive shaft 71, which will be described later. Therefore, when the ring 33 is fitted into the attachment portion-side recess 27 and the adapter-side recess 38 and the main body 31 is attached to the tool attachment portion 21, the centers of the holes (such as the adapter-side recess 38) coincide on the rotation axis 51. Furthermore, the positions of the four through holes 35 can be aligned with the positions of the four threaded portions 25, respectively.

[0018] For example, two O-rings 41 are provided on the outer peripheral surface of the ring 33. Each of the two O-rings 41 is provided to match the respective positions of the attachment portion-side recess 27 and the adapter-side recess 38. The ring 33 is attached with one O-ring 41 sandwiched between the attachment portion-side recess 27 and the other O-ring 41 sandwiched between the adapter-side recess 38 and the ring 33.

[0019] 3 and 4 , two Z-axis grooves 44A, 44B and two Y-axis grooves 45A, 45B are formed on the outer surface 43, which is the outer side of the main body 31 in the X-axis direction, i.e., the surface on which the tool 12 is attached. The Z-axis grooves 44A, 44B are generally rectangular parallelepiped grooves with openings on the outer surface 43, and are provided with the second insertion hole 37 between them (at the center) in the Z-axis direction and connected to the second insertion hole 37. The Z-axis grooves 44A, 44B are formed at positions that are the center of the main body 31 in the Y-axis direction and are formed along the Z-axis direction.

[0020] Similarly, the Y-axis grooves 45A and 45B are generally rectangular parallelepiped grooves with openings in the outer surface 43. They are located with the second insertion hole 37 between them (at their centers) in the Y-axis direction and are connected to the second insertion hole 37. The Y-axis grooves 45A and 45B are formed in the center of the main body 31 in the Z-axis direction and are formed along the Y-axis direction. The widths of the Y-axis grooves 45A and 45B and the Z-axis grooves 44A and 44B are the same. Furthermore, the midpoint of the groove formed along the Z-axis direction by the Z-axis grooves 44A and 44B and the midpoint of the groove formed along the Y-axis direction by the Y-axis grooves 45A and 45B coincide with the center (rotation axis 51) of the second insertion hole 37. The Z-axis grooves 44A and 44B and the Y-axis grooves 45A and 45B function as grooves into which, for example, protrusions provided on a tool holder 61 of the tool 12 are inserted to position the tool 12 relative to the adapter 13. Furthermore, the Z-axis grooves 44A and 44B are used in a checking operation after adjusting the orientation of the axis 69 of the cutting tool 62, as will be described later.

[0021] The main body 31 is formed with threaded portions 47 used to attach the tool 12. For example, four threaded portions 47 are formed. In a plan view of the main body 31, the four threaded portions 47 are formed at positions that are vertices of a square with one side having a predetermined pitch PT. As shown in FIG. 1 , the tool 12 includes a tool holder 61 and a cutting tool 62. The tool holder 61 is fixed to the adapter 13 by threading four second threaded members 63 into the four threaded portions 47, respectively. Therefore, the pitch PT and positions of the threaded portions 47 match the pitch and positions of through holes 64 (see FIG. 6 ) into which the second threaded members 63 of the tool holder 61 are inserted.

[0022] The position at which the second threaded member 63 is attached, the thickness of the second threaded member 63, and the shape of the convex rib portion 65 (described later) vary depending on the required function, rigidity, manufacturer, and other factors of the tool 12. Therefore, the adapter 13 is designed to accommodate each different type of tool 12. The position of the through hole 35 of the adapter 13 coincides with the position of the threaded portion 25 of the tool mounting portion 21. Furthermore, the position of the threaded portion 25 is the same for all tool mounting portions 21. Therefore, by attaching an adapter 13 with a matching threaded portion 47, the tool 12 can be attached to any tool mounting portion 21. Tools 12 from different manufacturers can be attached to any tool mounting portion 21. In other words, the position of the threaded portion 47 of the adapter 13 can be changed depending on the position of the through hole 64 of the tool 12 to be attached. Furthermore, the adapter 13 of this embodiment is equipped with an adjustment mechanism 32, allowing the orientation of the shaft 69 of the cutting tool 62 to be adjusted.

[0023] The cutting tool 62 is a rotary tool such as a drill, and rotates based on the rotational driving force transmitted from the tool post 11. FIG. 6 shows a cross-sectional view of a tool holder 61 for a tool 12 of a different type from that shown in FIG. 1 attached to the tool mounting portion 21. As shown in FIG. 6, a drive shaft 71 is provided inside the tool post 11. The drive shaft 71 is provided at an index position of the tool 12 and extends in the X-axis direction. The machine tool includes, for example, a servo motor (not shown), which is driven to rotate the drive shaft 71 around a rotation axis 51 parallel to the X-axis direction. Note that the axis of a cutting tool (not shown) attached to the tool holder 61 shown in FIG. 6 is, for example, oriented along the rotation axis 51. However, the structure of a ridge portion 65 (described later) is similar to that of the tool 12 shown in FIG. 1.

[0024] A clutch member 73 is provided at the tip of the drive shaft 71. The clutch member 73 is formed with, for example, a first groove portion 73A and a second groove portion 73B. The first and second groove portions 73A, 73B are formed on a straight line. The first groove portion 73A is formed in an orientation and position that is perpendicular to the second groove portion 73B, and the first and second groove portions 73A, 73B form a cross-shaped groove.

[0025] The tool holder 61 includes a transmission shaft 66 having a ridge portion 65 at its tip. The transmission shaft 66 rotates in conjunction with the rotation of the drive shaft 71, with the ridge portion 65 fitted into the first groove portion 73A and connected to the drive shaft 71. The transmission shaft 66 is connected to the cutting tool 62, and rotates the cutting tool 62 in conjunction with the rotation of the drive shaft 71. The shape and thickness of the ridge portion 65 vary depending on the manufacturer of the tool 12, etc. The first and second groove portions 73A, 73B are each formed with a width that matches the thickness of a different type of ridge portion 65. The clutch member 73 of this embodiment includes two types of groove portions, the first and second groove portions 73A, 73B, so that the groove portion to be used can be switched depending on the tool 12. When the machine tool rotates the tool post 11 to switch the tool 12 at the index position, the machine tool inserts the ridge 65 into the first groove 73A or the second groove 73B. The machine tool rotates the drive shaft 71 by 90 degrees, for example, to switch between the first groove 73A and the second groove 73B depending on the ridge 65 of the tool 12. This makes it possible to rotate tools 12 with different ridges 65 using a single drive shaft 71. The clutch member 73 may be configured to have one groove or three or more grooves.

[0026] Furthermore, the length of the transmission shaft 66 along the X-axis direction and the position of the ridge portion 65 in the X-axis direction differ depending on the manufacturer, etc. Therefore, the thickness W of the adapter 13 is determined according to the length of the transmission shaft 66 and the position of the ridge portion 65. The thickness W of the main body 31 along the X-axis direction is determined so that the ridge portion 65 is positioned in the first groove portion 73A or the second groove portion 73B.

[0027] Therefore, the drive shaft 71 of the tool rest 11 rotates based on the drive of a drive source such as a servo motor with the ridge 65 coupled to the first and second grooves 73A, 73B, transmitting a rotational drive force to the transmission shaft 66 and rotating the cutting tool 62. The thickness W of the adapter 13 in the X-axis direction corresponds to the distance between the ridge 65 of the tool holder 61 and the first and second grooves 73A, 73B of the tool rest 11. This allows the position of the ridge 65 in the X-axis direction to be adjusted by the thickness W of the main body 31, thereby aligning the position of the ridge 65 with the positions of the first and second grooves 73A, 73B. In other words, the adapter 13 functions as a spacer, allowing the ridge 65 to be appropriately coupled to the first groove 73A or the second groove 73B. Furthermore, even if a tool 12 has a different position of the ridge 65, it can be attached to any tool mounting portion 21 via the adapter 13.

[0028] To improve the machining accuracy of the workpiece, it is preferable that the axis 69 of the cutting tool 62 is parallel to the central axis of the workpiece to be machined. In other words, it is preferable that the straightness of the axis 69 of the cutting tool 62 relative to the workpiece spindle is smaller. In this embodiment, the central axis of the workpiece is parallel to the Z-axis direction. The adjustment mechanism 32 adjusts the orientation of the axis 69 of the cutting tool 62 attached to the tool holder 61 by rotating the main body 31 disposed on the tool mounting portion 21. Therefore, the cutting tool 62 of the present disclosure is not limited to a drill, and cutting tools such as taps, reamers, and milling cutters can also be used. Therefore, the cutting tool of the present disclosure can be any tool that requires adjustment of the straightness of the cutting tool axis during machining. For example, the cutting tool may be a boring tool, such as a tool used to further enlarge a pilot hole drilled by a drill.

[0029] Furthermore, the cutting tool of the present disclosure can be any cutting tool that can be attached to the tool attachment portion 21 via a tool holder. Therefore, the tool holder of the present disclosure may be a tool holder that does not have a rotation mechanism such as a transmission shaft 66. Furthermore, the tool rest 11 may not have a mechanism for rotating the cutting tool such as a drive shaft 71. Therefore, the machine tool to which the tool holder adapter of the present disclosure is attached may be a machining center with a turret-type ATC. In this case, the adapter 13 can be used as an adapter 13 that adjusts the straightness of the axis of the cutting tool, rather than as a spacer that adjusts the distance between the above-mentioned ridge portion 65 and the clutch member 73.

[0030] As shown in FIGS. 3 and 4 , the adjustment mechanism 32 includes a pair of adjustment bolts 53, 54 and a pair of washers 55, 56. The pair of adjustment bolts 53, 54 are, for example, hexagon socket bolts. Each of the pair of washers 55, 56 is, for example, a flat washer, and is inserted into the adjustment bolts 53, 54. The adjustment bolts 53, 54 are an example of an adjustment screw member of the present disclosure. The washers 55, 56 are an example of an engagement portion of the present disclosure. Note that the engagement portion of the present disclosure is not limited to a flat washer, but may also be a spring washer or other type of washer such as a rosette washer. The engagement portion may also be another member into which an adjustment screw member, such as a nut, can be inserted. The engagement portion is not limited to a separate member from the adjustment screw member, but may also be part of the adjustment screw member. For example, the engagement portion may be the head of a bolt. In this case, the heads of the adjustment bolts 53 and 54 may be engaged with an engaged surface 83, which will be described later.

[0031] A pair of screwed adjustment portions 58, 59 are formed on the main body 31. Each of the pair of screwed adjustment portions 58, 59 has an opening on a screwed surface 81 on the base end side of the main body 31, and is formed along a direction parallel to the Z-axis direction. The screwed surface 81 is a flat surface along the X-axis direction and the Y-axis direction. The screwed adjustment portions 58, 59 are formed at positions spaced apart from each other in the Y-axis direction. The pair of screwed adjustment portions 58, 59 are formed with female threads into which the pair of adjustment bolts 53, 54 are screwed, respectively.

[0032] 3 and 5, the tool post 11 is provided with an engaged surface 83. The engaged surface 83 is formed on the base end surface of the tool post 11 and has an annular shape formed along the outer periphery of the tool post 11. The engaged surface 83 is recessed toward the tip end and is located closer to the tip end in the Z-axis direction than a portion of the engaged surface 83 that is inward in the X-axis direction. The engaged surface 83 is a reference surface for adjusting straightness, as will be described later, and is a surface that requires high machining accuracy. Therefore, by forming the engaged surface 83 only on a portion along the outer edge of the tool post 11 and limiting the portion where it is formed, the effort required to machine the engaged surface 83 can be reduced.

[0033] The adjustment bolt 53 is threaded into the adjustment threaded portion 58 with a washer 55 fitted thereto. The adjustment bolt 53 is threaded into the adjustment threaded portion 58 with the washer 55 engaged with the engagement surface 83 and with a gap 85 provided between the threaded surface 81 and the engagement surface 83 in the Z-axis direction. Similarly, the adjustment bolt 54 is threaded into the adjustment threaded portion 59 with the washer 56 engaged with the engagement surface 83 and with a gap 85 provided between the threaded surface 81 and the engagement surface 83. The size of the gap 85 is, for example, 50 μm. For example, the distance from the rotation shaft 51 to the threaded surface 81 in the Z-axis direction is shorter by the gap 85 than the distance from the rotation shaft 51 to the engagement surface 83.

[0034] When adjusting the straightness, for example, the worker temporarily tightens the four first screw members 17 to the threaded portions 25 and attaches the main body 31 to the tool attachment portion 21 without completely fixing it. The threaded surface 81 is aligned in the Y-axis direction, and the gap between the washer 55 and the threaded surface 81 in the Z-axis direction and the gap between the washer 56 and the threaded surface 81 are made equal, so that the two gaps coincide with the gap 85. The following description will be based on the state before this adjustment. The adjustment of the gap 85 may also be performed with the first screw members 17 removed. That is, the adjustment may also be performed with the adapter 13 attached to the tool attachment portion 21 via the ring 33.

[0035] As shown in FIG. 4 , the adjustment threaded portion 58 is provided on the opposite side of the adjustment threaded portion 59 across a midpoint 87 of the threaded surface 81 in the Y-axis direction. The midpoint 87 is located on a line that passes through the rotation axis 51 and is parallel to the Z-axis direction. The Z-axis grooves 44A, 44B are formed along a line connecting the midpoint 87 and the rotation axis 51. The distance L1 from the midpoint 87 to the adjustment threaded portion 58 is the same as the distance L2 from the midpoint 87 to the adjustment threaded portion 59. As shown in FIG. 3 , the threaded surface 81 is formed with a coolant hole 89 for supplying coolant at a position that is central in the Y-axis direction.

[0036] For example, as shown in FIG. 7 , an operator adjusts the orientation of the shaft 69 of the cutting tool 62 after the tool 12 is attached by turning the adjustment bolts 53, 54 of each adapter 13 with a hex wrench 91 to adjust the rotational position of the adapter 13. When the adjustment bolt 53 is rotated in a direction tightening the adjustment threaded portion 58, the washer 55 engages with the engagement surface 83, causing the main body 31 to rotate clockwise around the rotation axis 51 in FIG. 4 as shown by the solid arrow in FIG. 4 . The gap 85 between the washer 55 and the engagement surface 81 becomes narrower than before the adjustment bolt 53 was turned. Similarly, when the adjustment bolt 54 is tightened against the adjustment threaded portion 59, the main body 31 rotates counterclockwise around the rotation axis 51 in FIG. 4 as shown by the dashed arrow in FIG. 4 . The gap 85 between the washer 56 and the threaded surface 81 becomes narrower than before the adjustment bolt 54 is turned. Therefore, the adjustment mechanism 32 narrows the gap 85 as the pair of adjustment bolts 53, 54 are threaded into the adjustment threaded portions 58, 59, respectively, and rotates the main body portion 31 relative to the tool attachment portion 21. This makes it possible to adjust the rotational position of the main body portion 31 by changing the amount of tightening of each of the pair of adjustment bolts 53, 54. In other words, it is possible to adjust the rotational position of the tool 12 attached to the adapter 13 relative to the tool attachment portion 21. The axis 69 of the cutting tool 62 can be made parallel to the Z-axis direction.

[0037] For example, as shown in FIG. 7 , an operator places a fixed-position dial gauge 93 in contact with the side surface of the Z-axis groove 44A and adjusts it to the zero point. Then, the operator operates the machine tool to slide the tool post 11 in the Z-axis direction. The operator can adjust the straightness of the cutting tool 62 by placing the dial gauge 93 against both the Z-axis groove 44A and the Z-axis groove 44B and checking the scale of the dial gauge 93. The smaller the amplitude of the dial gauge 93's swing in both the Z-axis groove 44A and the Z-axis groove 44B, the smaller the straightness of the shaft 69 of the cutting tool 62 relative to the Z axis can be. Preferably, the dial gauge 93 is at the zero point in both the Z-axis grooves 44A and 44B. Therefore, by forming Z-axis grooves 44A, 44B aligned in the Z-axis direction (the axial direction of the cutting tool 62) on the outer surface 43 of the main body 31 to which the tool holder 61 is attached, the straightness can be easily confirmed by placing a dial gauge 93 on the Z-axis grooves 44A, 44B. Note that a device other than the dial gauge 93 may be used to confirm the straightness.

[0038] 5 and 6, the main body 31 is formed with a second insertion hole 37 into which the transmission shaft 66 is inserted in the X-axis direction when attaching the tool 12 to the adapter 13. As shown in Fig. 4, the pair of adjustment bolts 53, 54 are provided in positions sandwiching the second insertion hole 37 in the Y-axis direction when the adapter 13 is attached to the tool attachment portion 21. This allows the pair of adjustment bolts 53, 54 to be provided in positions away from the midpoint 87 (rotation axis 51) in the Y-axis direction, thereby increasing the ratio of the amount of rotation to the amount of tightening.

[0039] In this embodiment, for example, the adjustment bolt 53 is provided in the Y-axis direction between the end (the upper end in FIG. 4 ) of the main body 31 and the midpoint 87, at a position closer to the end (upper side) of the main body 31. Similarly, the adjustment bolt 54 is provided in a position closer to the lower side. Note that the pair of adjustment bolts 53, 54 may be provided in positions facing the second insertion hole 37 in the Z-axis direction (on the base end side of the second insertion hole 37).

[0040] As described above, the threaded surface 81 is formed on the surface (base end surface) of the main body 31 that faces the shaft 14 supporting the tool post 11 in the Z-axis direction. It is also possible to provide the adjustment bolts 53, 54 and the threaded adjustment portions 58, 59 on the surface facing the workpiece to be machined (the cutting tool 62 side, tip end). However, the tip end surface faces the workpiece spindle device and is likely to scatter chips during machining. The adjustment mechanism 32 adjusts the rotational position of the adapter 13 by changing the size of the gap 85. If chips enter the gap 85, the adjustment accuracy may be reduced. Therefore, by positioning the threaded surface 81 on the base end side, chips are prevented from entering the gap 85, preventing a reduction in adjustment accuracy.

[0041] Furthermore, the main body 31 is attached to the tool mounting portion 21 so as to be rotatable about a predetermined rotation axis (rotation axis 51 in this embodiment). The adjustment mechanism 32 rotates the main body 31 about this rotation axis 51. As a result, by attaching the adapter 13 to the tool mounting portion 21 in a rotatable state and operating the adjustment mechanism 32, the adapter 13 can be rotated relative to the tool mounting portion 21 and the rotational position of the adapter 13 can be adjusted.

[0042] As described above, the tool mounting portion 21 and the adapter 13 are assembled together by fitting the ring 33, so that the centers of the second insertion hole 37, the adapter-side recess 38, the attachment-side recess 27, and the first insertion hole 23 all lie on the rotation axis 51. Therefore, the adjustment mechanism 32 rotates the main body 31 around the rotation axis 51, which is a line passing through the center of the attachment-side recess 27 and the center of the adapter-side recess 38. This allows the main body 31 to be rotated while aligning the centers of the adapter 13 and the tool mounting portion 21. Furthermore, rotation of the main body 31 can prevent misalignment between the ridge 65 and the first and second grooves 73A and 73B.

[0043] As shown in FIG. 7 , the operator adjusts the rotational position of the main body 31 using a hex wrench 91 and a dial gauge 93, then fully tightens the first threaded member 17 to secure the adapter 13 to the tool mounting portion 21. This fixes the rotational position of the adapter 13 relative to the tool mounting portion 21, and the adapter 13 is fixed at the adjusted rotational position. The operator aligns the through-hole 64 with the position of the threaded engagement member 47 of the fixed adapter 13 and places the tool 12. The operator inserts the second threaded member 63 into the through-hole 64 and tightens it to secure the tool 12 to the adapter 13 (tool mounting portion 21). This secures the tool 12 at the adjusted rotational position. As shown in FIG. 1 , similar to FIG. 7 , the operator can perform a final check of the straightness of the shaft 69 by placing the dial gauge 93 on the cutting tool 62 and moving the tool post 11 in the Z-axis direction.

[0044] Therefore, the adjustment mechanism 32 of this embodiment is positioned so that it can be operated (adjusted) when the main body 31 is attached to the tool attachment portion 21 with the first threaded member 17 and when the tool holder 61 is removed from the main body 31. The main body 31 also has a threaded portion 47 into which the second threaded member 63 of the tool holder 61 is threaded. The threaded portion 47 is positioned so that the second threaded member 63 can be threaded onto the threaded portion 47 after the adjustment mechanism 32 adjusts the rotational position of the main body 31. This allows the orientation of the shaft 69 of the cutting tool 62 to be adjusted even when the tool holder 61 is removed. In other words, as long as the tools 12 are compatible with the pitch PT of the adapter 13, the orientation of the shaft 69 of the cutting tool 62 of all the tools 12 can be adjusted. For tools 12 of the same type, it is not necessary to adjust the orientation of the shaft 69 of the cutting tool 62 every time the tool 12 is replaced.

[0045] Incidentally, the correspondence between the terms used in this embodiment and those described in the claims will be explained below. The outer surface 43 of this embodiment is an example of a surface of the present disclosure. The Z-axis grooves 44A, 44B are an example of grooves formed in a straight line in the Z-axis direction parallel to the rotation axis of the tool post. The threaded portion 47 is an example of a tool threaded portion. The adjustment bolts 53, 54 are an example of an adjustment threaded member. The washers 55, 56 are an example of an engaging portion. The second threaded member 63 is an example of a tool-side threaded member. The first and second groove portions 73A, 73B are an example of a groove portion.

[0046] As described above, the present embodiment provides the following advantages. The adapter 13, which is one aspect of the present embodiment, includes a main body 31 and an adjustment mechanism 32. The main body 31 can be attached to the tool mounting portion 21 of the tool post 11, and the tool holder 61 can be attached to the main body 31 while it is attached to the tool mounting portion 21. The adjustment mechanism 32 adjusts the orientation of the axis 69 of the cutting tool 62 attached to the tool holder 61 by rotating the main body 31 attached to the tool mounting portion 21.

[0047] With this, the orientation of the axis 69 of the cutting tool 62 can be adjusted by rotating the main body 31 with the adjustment mechanism 32. The accuracy with which the axis 69 of the cutting tool 62 is parallel to the central axis of the workpiece (accuracy of straightness) can be adjusted by the adapter 13, and after adjustment, the tool holder 61 can be attached to the adapter 13. Furthermore, if the tool holder 61 is replaced without removing the adapter 13, the tool 12 can be replaced without adjusting the straightness.

[0048] Furthermore, by adjusting the thickness W of the adapter 13, the position of the cutting edge of the cutting tool 62 in the X-axis direction can also be adjusted. The error in the position of the cutting edge in the X-axis direction for each tool mounting portion 21 can be adjusted by the thickness W of the adapter 13. When a tool 12 (cutting tool 62) attached to a given tool mounting portion 21 is attached to another tool mounting portion 21, the thickness W of the adapter 13 can reduce the error in the position in the X-axis direction. Therefore, it is no longer necessary to modify the NC program to adjust the position of the cutting edge in the X-axis direction every time the mounting position of the tool 12 is changed. The adapter 13 can also be used as a component for adjusting the position of the cutting edge in the X-axis direction.

[0049] The present disclosure is not limited to the above-described embodiment, and various improvements and modifications are possible within the spirit and scope of the present disclosure. For example, the configurations of the tool post 11, tool 12, and adapter 13 described above are merely examples. For example, the adapter 13 may be configured to have a number of through holes 35 other than four. The main body 31 may be configured to have only one adjustment threaded portion, or three or more. Therefore, the adjustment mechanism 32 may be configured to have only one set of adjustment bolts and washers, or three or more sets. The distance L1 may be different from the distance L2. The adjustment bolts 53, 54 and the adjustment threaded portions 58, 59 may be provided on a surface other than the threaded surface 81, for example, on the distal end surface of the main body 31. The cross-sectional shapes of the second insertion hole 37, the adapter-side recess 38, the attachment-side recess 27, and the first insertion hole 23 do not have to be circular. The inner diameter of the second insertion hole 37 may be different from the inner diameter of the first insertion hole 23. The ring 33 may not include an O-ring 41, or may include one or three or more O-rings 41.

[0050] The ring 33 is not limited to a circular member, but may also be an elliptical or rectangular member. The method of rotatably mounting the adapter 13 to the tool mounting portion 21 is not limited to the method using the ring 33 in the above embodiment. For example, a thin cylindrical protrusion may be provided on the inner surface 39 of the adapter 13, and a circular recess into which the protrusion fits may be provided on the mounting surface 22 of the tool mounting portion 21. This allows the adapter 13 to be rotatably mounted to the tool mounting portion 21 around a rotation axis passing through the center of the cylindrical protrusion. When the adapter 13 is mounted to the tool mounting portion 21, the centers of the mounting portion-side recess 27 and the adapter-side recess 38 do not need to coincide. The adapter 13 may be configured without the Z-axis grooves 44A, 44B and the Y-axis grooves 45A, 45B. The groove widths of the Y-axis grooves 45A, 45B may be different from those of the Z-axis grooves 44A, 44B. With the tool 12 attached to the adapter 13, the rotational position may be adjusted by turning the adjustment bolts 53 and 54.

[0051] The scope of the present disclosure is not limited to the dependent relationships set forth in the claims. For example, this specification also discloses a technical idea in which claim 4 changes "the tool holder adapter according to claim 2" to "the tool holder adapter according to claim 2 or claim 3." For example, this specification also discloses a technical idea in which claim 5 changes "the tool holder adapter according to claim 1 or claim 2" to "the tool holder adapter according to any one of claims 1 to 4." For example, this specification also discloses a technical idea in which claim 7 changes "the tool holder adapter according to claim 1 or claim 2" to "the tool holder adapter according to any one of claims 1 to 6." For example, this specification also discloses a technical idea in which claim 8 changes "the tool holder adapter according to claim 1 or claim 2" to "the tool holder adapter according to any one of claims 1 to 7." For example, this specification also discloses a technical idea in which claim 9 changes "the tool holder adapter according to claim 1 or claim 2" to "the tool holder adapter according to any one of claims 1 to 8."

[0052] REFERENCE SIGNS LIST 11 Tool rest, 13 Tool holder adapter, 14 Shaft portion, 21 Tool mounting portion, 27 Mounting portion side recess, 31 Main body portion, 32 Adjustment mechanism, 33 Ring, 37 Second insertion hole (insertion hole), 38 Adapter side recess, 43 Outer surface (surface), 44A, 44B Z-axis groove (groove), 47 Threaded engagement (tool threaded engagement portion), 51 Rotation shaft, 53, 54 Adjustment bolt (adjustment threaded member), 55, 56 Washer (engagement portion), 58, 59 Adjustment threaded engagement portion, 61 Tool holder, 62 Cutting tool, 63 Second threaded engagement member (tool side threaded member), 65 Convex ridge portion, 66 Transmission shaft, 69 Shaft, 71 Drive shaft, 73A First groove portion (groove portion), 73B Second groove portion (groove portion), 81 Threaded engagement surface, 83 Engaged surface, 85 clearance, W thickness.

Claims

1. A tool holder adapter comprising: a main body that can be attached to a tool mounting portion of a tool post, and to which a tool holder can be attached while attached to the tool mounting portion; and an adjustment mechanism that adjusts the axial orientation of a cutting tool attached to the tool holder by rotating the main body that is attached to the tool mounting portion.

2. A tool holder adapter according to claim 1, wherein the adjustment mechanism comprises an adjustment screw member and an engaging portion provided on the adjustment screw member, the main body having an adjustment threaded portion on its threaded surface into which the adjustment screw member is threaded, the adjustment screw member is threaded onto the adjustment threaded portion of the main body with the engaging portion engaging with the engaged surface of the tool post and with a gap between the threaded surface and the engaged surface in a Z-axis direction parallel to the rotation axis of the tool post, and the adjustment mechanism narrows the gap between the threaded surface and the engaged surface as the adjustment screw member is threaded onto the adjustment threaded portion, causing the main body to rotate relative to the tool mounting portion.

3. The tool holder adapter according to claim 2, wherein the cutting tool is a rotary tool, the tool holder has a transmission shaft with a ridge portion, the tool rest has a drive shaft provided with a groove portion into which the ridge portion is inserted, and the drive shaft rotates based on the drive of a drive source with the ridge portion and the groove portion coupled to each other, thereby transmitting a rotational drive force to the transmission shaft and rotating the cutting tool, the adjustment mechanism has a pair of the adjustment screw members, and the main body portion has a pair of the adjustment threaded portions and is formed with an insertion hole into which the transmission shaft is inserted, and the pair of the adjustment threaded portions are provided at positions sandwiching the insertion hole in the Y-axis direction perpendicular to the Z-axis direction when the tool holder adapter is attached to the tool mounting portion.

4. A tool holder adapter as set forth in claim 2, wherein the threaded surface is formed on the surface of the main body portion that faces the shaft portion supporting the tool post in the Z-axis direction.

5. A tool holder adapter as claimed in claim 1 or claim 2, wherein the main body is attached to the tool mounting portion so as to be rotatable about a predetermined rotation axis, and the adjustment mechanism rotates the main body about the rotation axis.

6. A tool holder adapter according to claim 5, wherein: the tool mounting portion has a mounting portion-side recess having a circular cross section; the main body has an adapter-side recess having a circular cross section formed on a surface that is attached to the tool mounting portion; the tool holder adapter is rotatably attached to the tool mounting portion by inserting annular rings into both the mounting portion-side recess and the adapter-side recess; when the main body is attached to the tool mounting portion with the rings inserted into both the mounting portion-side recess and the adapter-side recess, the center of the mounting portion-side recess and the center of the adapter-side recess coincide in a plan view of the main body; and the adjustment mechanism rotates the main body about a rotation axis that is a straight line passing through the center of the mounting portion-side recess and the center of the adapter-side recess.

7. A tool holder adapter as claimed in claim 1 or claim 2, wherein the main body has a groove formed in a straight line in the Z-axis direction parallel to the rotation axis of the tool post on the surface to which the tool holder is attached.

8. The tool holder adapter according to claim 1 or claim 2, wherein the adjustment mechanism is provided at a position where it can be operated when the main body is attached to the tool mounting portion and when the tool holder is detached from the main body, and the main body has a tool threaded portion into which a tool-side threaded member of the tool holder is threaded, and the tool threaded portion is provided at a position where the tool-side threaded member of the tool holder can be threaded after the rotational position of the main body is adjusted by the adjustment mechanism.

9. A tool holder adapter according to claim 1 or 2, wherein the cutting tool is a rotary tool, the tool holder has a transmission shaft with a ridge portion, the tool rest has a drive shaft provided with a groove portion into which the ridge portion is inserted, the drive shaft rotates based on the drive of a drive source with the ridge portion and the groove portion connected to each other, thereby transmitting a rotational driving force to the transmission shaft and rotating the cutting tool, and the thickness of the tool holder adapter is a thickness corresponding to the distance between the ridge portion of the tool holder and the groove portion of the tool rest.

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