Fitting of tool holder

Abstract

The fitting of the tool holder includes: a fitting main body connecting a tool mounting portion included in a machine tool and the tool holder; and a sensor unit that is attached to the attachment body and has at least one sensor element that detects a physical quantity of the attachment body.

Description

Technical Field

[0001] This disclosure relates to accessories for tool holders. Background Technology

[0002] A known technology involves using a machine tool to measure the physical quantities of the cutting tool during machining of a workpiece, thereby controlling the tool's state (e.g., see U.S. Patent Application Publication No. 2015 / 0261207 (Patent Document 1), Japanese Patent Application Publication No. 2018-54611 (Patent Document 2), Japanese Patent Application Publication No. 2009-285804 (Patent Document 3), International Publication No. 2017 / 002762 (Patent Document 4), and Japanese Patent No. 59). Patent No. 88066 (Patent Document 5), Utility Model Registration No. 3170029 (Patent Document 6), Japanese Patent Application Publication No. 2015-77658 (Patent Document 7), International Publication No. 2015 / 056495 (Patent Document 8), European Patent Application Publication No. 3292929 (Patent Document 9), European Patent Application Publication No. 3292930 (Patent Document 10), and U.S. Patent Application Publication No. 2009 / 0235763 (Patent Document 11).

[0003] Existing technical documents Patent documents Patent document 1: U.S. Patent Application Publication No. 2015 / 0261207; Patent Document 2: Japanese Patent Application Publication No. 2018-54611; Patent Document 3: Japanese Patent Application Publication No. 2009-285804; Patent Document 4: International Publication No. 2017 / 002762; Patent document 5: Japanese Patent Application Publication No. 2016-221665; Patent Document 6: Japanese Utility Model Registration No. 3170029; Patent document 7: Japanese Patent Application Publication No. 2015-77658; Patent document 8: International Publication No. 2015 / 056495; Patent document 9: European Patent Application Publication No. 3292929; Patent document 10: European Patent Application Publication No. 3292930; Patent document 11: U.S. Patent Application Publication No. 2009 / 0235763. Summary of the Invention

[0004] The tool holder accessory according to this disclosure includes: an accessory body that connects a tool mounting portion of a machine tool to the tool holder; and a sensor part that is mounted on the accessory body and has at least one sensor element for detecting physical quantities of the accessory body. Attached Figure Description

[0005] Figure 1 This is a schematic front view showing the state in which accessories and tool holders are installed on the tool mounting section of the machine tool in the embodiment.

[0006] Figure 2 This is a schematic perspective view of the accessories involved in the implementation method.

[0007] Figure 3 It includes Figure 2 A rough cross-sectional view of the BB line.

[0008] Figure 4 This is a schematic top view of the components involved in the implementation method, viewed from a second direction.

[0009] Figure 5 This is a schematic bottom view of the components involved in the implementation method, viewed from the first direction.

[0010] Figure 6 It includes Figure 1 A schematic cross-sectional view of the CC line.

[0011] Figure 7 This is a schematic three-dimensional drawing of the accessories involved in the modified example.

[0012] Figure 8 It includes Figure 7 A schematic cross-sectional view of the DD line.

[0013] Figure 9 yes Figure 8 Enlarged view of section A.

[0014] Figure 10 This is a rough bottom view of the components involved in the modified example, viewed from the first direction.

[0015] Figure 11 It is an accessory with a housing installed, including Figure 7 A schematic cross-sectional view of the DD line. Detailed Implementation

[0016] [The problem this disclosure aims to solve] When using tool holders equipped with sensors to monitor the status of cutting tools, the following problems arise. Because the type of tool holder to be used must be selected based on the machining method of the part being formed, sensors need to be installed on various tool holders. For example, in high-load cutting operations, a milling chuck with high holding force is required as the tool holder. Conversely, in high-precision cutting operations, a water chuck or a thermo-pressurized retainer is required.

[0017] Therefore, when using a tool holder equipped with sensor units, there is a problem of an increased number of sensor units. Therefore, one object of the present invention is to provide a tool holder accessory that reduces the number of sensor units when it is desired to monitor the state of the cutting tool via sensor units during the machining of a formed part. Hereinafter, the tool holder accessory will be referred to as "accessory".

[0018] [Effects of the Invention] According to the accessories disclosed herein, when it is desired to monitor the state of the cutting tool through the sensor unit during the machining of a shaped part, the number of sensor units can be reduced.

[0019] [Description of Embodiments of the Invention] First, embodiments related to this disclosure will be described. The accessory according to this invention includes: an accessory body that connects a tool mounting portion of a machine tool to a tool holder; and a sensor unit mounted on the accessory body, having at least one sensor element for detecting physical quantities of the accessory body.

[0020] In the accessory disclosed herein, a sensor unit is mounted on the accessory body. Using this accessory, a tool holder selected from a variety of tool holders is mounted on the tool mounting section as needed. Therefore, even when using multiple tool holders, the state of the cutting tool can be monitored via the sensor unit mounted on the accessory. As a result, the number of sensor units can be reduced when monitoring the state of the cutting tool via the sensor unit is desired during the machining of formed parts. Consequently, the initial cost of introducing the sensor units can be reduced, and operating costs can be reduced by minimizing the maintenance of the sensor units. The state of the cutting tool refers to the current state of the cutting tool based on an evaluation of physical quantities generated within the cutting tool (e.g., wear, fatigue, breakage, peeling, plastic deformation, cracks). By monitoring the state of the cutting tool, for example, it is possible to determine the timing of tool replacement and predict abnormalities in the cutting tool.

[0021] In the accessory, the sensor unit may also include a wireless communication unit that transmits signals generated based on the detection of the sensor element to the outside. According to this structure, signals containing information about the physical quantities of the accessory body are immediately transmitted to the outside via the wireless communication unit, thus enabling real-time processing.

[0022] In the accessory, the sensor unit may also include a power supply unit that supplies power to the sensor element. According to this structure, power can be supplied to the sensor element from the power supply unit mounted on the accessory body.

[0023] The accessory may also include a housing that accommodates the at least one sensor element. This structure easily protects the sensor element from foreign objects such as chips.

[0024] Alternatively, the accessory may also include a sealing portion between the outer peripheral surface of the accessory body and the housing, which surrounds the at least one sensor element. This structure reduces the amount of foreign matter such as liquids and fine chips that can enter the housing.

[0025] In the aforementioned accessory, the accessory body may have a base, a handle, and a gripping portion. The handle protrudes from the base along a first direction from the tool holder toward the tool mounting portion and is mounted to the tool mounting portion. The gripping portion protrudes from the base along a second direction from the tool mounting portion toward the tool holder and includes an insertion hole for inserting the handle of the tool holder. The outer peripheral surface of the handle may also include a tapered surface that approaches the central axis as it moves toward the first direction. According to this structure, when the accessory is mounted to the tool mounting portion, the tapered surface of the handle easily comes into close contact with the inner peripheral surface of the tool mounting portion, and the constraint force of the accessory on the tool mounting portion is easily increased. In addition, the offset of the central axis of the accessory relative to the central axis of the tool mounting portion can be reduced.

[0026] In the aforementioned accessory, the accessory body may have a base, a handle, and a gripping portion. The handle protrudes from the base along a first direction from the tool holder toward the tool mounting portion and is mounted to the tool mounting portion. The gripping portion protrudes from the base along a second direction from the tool mounting portion toward the tool holder and includes an insertion hole for inserting the handle of the tool holder. Alternatively, the inner circumferential surface surrounding the insertion hole may include a tapered surface that approaches the central axis as it moves toward the first direction. According to this structure, when the tool holder is mounted to the accessory, the outer circumferential surface of the tool holder's handle easily comes into close contact with the inner circumferential surface of the accessory, and the constraint force of the tool holder relative to the accessory is easily increased. Furthermore, the offset of the central axis of the tool holder relative to the central axis of the accessory can be reduced.

[0027] In the accessory, a virtual plane orthogonal to the second direction and intersecting the at least one sensor element may also intersect the insertion hole. According to this structure, the sensor element can be positioned near the tool holder in the accessory, thus facilitating the monitoring of the cutting tool's status.

[0028] Alternatively, in the accessory, the at least one sensor element includes a detection area, i.e., a region for detecting the physical quantity, and the virtual plane intersecting the detection area intersects the insertion hole. According to this structure, the detection area in the sensor element is positioned close to the insertion hole, thus facilitating the detection of physical quantities in the accessory body.

[0029] Alternatively, in the accessory, a recess is formed on the outer peripheral surface of the accessory body for at least a portion of the at least one sensor element to be disposed. With this structure, the position where the sensor element should be disposed on the outer peripheral surface of the accessory body can be easily determined.

[0030] In the accessory, the sensor section may further include a substrate and wiring that electrically connects the substrate to the at least one sensor element. Alternatively, the at least one sensor element may be positioned relative to the substrate in a region in a second direction from the tool mounting portion toward the tool holder. According to this structure, by positioning the sensor element close to the tool holder in the accessory body, the state of the cutting tool can be easily monitored.

[0031] In the accessory, the gripping portion may also have a placement portion for the at least one sensor element to be placed and recessed from the outer peripheral surface of the gripping portion. Alternatively, the thickness between the outer peripheral surface of the gripping portion and the inner peripheral surface surrounding the insertion hole may be configured to vary upward along a third direction along the intersection of the virtual plane and the inner surface. The placement portion may also be formed at a position offset upward relative to a portion of the outer peripheral surface of the gripping portion corresponding to the minimum value of the thickness. According to this structure, by forming the placement portion while determining the position where the sensor element should be placed, the reduction in rigidity of the accessory body can be mitigated.

[0032] In the aforementioned accessory, the at least one sensor element may also comprise a force sensor element. Based on this structure, strain generated in the accessory body can be measured.

[0033] In the accessory, the at least one sensor element may also include an acceleration sensor element or an AE (Acoustic Emission) sensor element. According to this configuration, the acceleration sensor element or AE sensor element is positioned near the insertion hole, thus facilitating the detection of vibrations generated within the accessory.

[0034] Alternatively, in the accessory, the at least one sensor element may comprise a temperature sensor element. According to this configuration, the temperature sensor element is positioned near the insertion hole, thus facilitating its placement away from the cooling path through which the cooling water passes. As a result, the temperature sensor element is less susceptible to the influence of the cooling water and can appropriately detect heat conducted from the tool holder.

[0035] Alternatively, in the fitting, the fitting body has a slit formed along the intersection of the outer surface and the virtual plane on its outer peripheral surface. The at least one sensor element may also include a force sensor element mounted across the slit. According to this structure, strain generated in the portion where the force sensor element is mounted is locally amplified, thus easily improving the sensitivity of the force sensor element to strain.

[0036] Alternatively, in the accessory, the outer peripheral surface of the handle has the same shape as the inner peripheral surface surrounding the insertion hole. According to this structure, an extension can be used as the accessory.

[0037] In the aforementioned accessory, the inner circumferential surface of the handle can also have a different shape from the inner circumferential surface surrounding the insertion hole. Based on this structure, an adapter can be used as the accessory.

[0038] [Details of the embodiments of the present invention] Next, embodiments of accessory 10 involved in this disclosure will be described with reference to the accompanying drawings. In the drawings, the same or corresponding parts are labeled with the same reference numerals, and their descriptions will not be repeated.

[0039] Figure 1 This is a schematic front view showing an example of the state in which the accessory 10 and tool holder 4 involved in this embodiment are installed on a machine tool. (Refer to...) Figure 1 In this embodiment, the accessory 10 is installed between the tool mounting section 6 and the tool holder 4 of the machine tool. The machine tool forms a shaped part by cutting the workpiece. Examples of machine tools include machining centers, milling machines (general-purpose milling machines, NC (Numerical Control) milling machines, etc.) that are mainly used for milling, and lathes (general-purpose lathes, NC lathes) that are mainly used for turning. In this embodiment, a machine tool that is mainly used for milling is described as an example.

[0040] Reference Figure 1In this disclosure, the direction from the tool holder 4 toward the tool mounting portion 6 is defined as "first direction D1". The direction from the tool mounting portion 6 toward the tool holder 4 is defined as "second direction D2". In this embodiment, the tool mounting portion 6 is a spindle. Therefore, in this embodiment, both the first direction D1 and the second direction D2 are along the rotation axis R1 of the tool holder 4 and the tool mounting portion 6 (spindle).

[0041] In two opposing directions along the arc centered on the axis of rotation R1, viewed from the second direction D2, the clockwise (right-handed) direction is defined as "third direction R3," and the counterclockwise (left-handed) direction is defined as "fourth direction R4." The designations "first direction D1," "second direction D2," "third direction R3," and "fourth direction R4" are merely markers used to distinguish directions and do not imply any order of precedence.

[0042] In this disclosure, "parallel" includes not only the case where two extended lines, edges, surfaces, etc., do not intersect, but also the case where the angle between them is within 3 degrees. "Orthogonal" includes not only the case where two extended lines, edges, surfaces, etc., intersect at 90 degrees, but also the case where they intersect within a range of 90 degrees ± 3 degrees.

[0043] Reference Figure 1 The machine tool has a tool mounting section 6 capable of mounting accessory 10. In addition to mounting accessory 10, tool holder 4 can also be directly mounted in the tool mounting section 6. The tool mounting section 6 includes an opening (hereinafter referred to as the insertion opening 61). Either the shank 12 of accessory 10 or the shank 41 of tool holder 4 can be inserted into the insertion opening 61.

[0044] A cutting tool 5 is mounted on the tool holder 4. In this embodiment, a milling tool is used as the cutting tool 5. Examples of milling tools include end mills, drills, milling cutters, boring tools, reamers, and taps.

[0045] (Structure overview of accessory 10) Figure 2 This is a schematic perspective view showing the structure of accessory 10 involved in this embodiment. Figure 3 It includes Figure 2 A schematic cross-sectional view showing the BB line in the diagram and cut off at the section intersecting with sensor element 31. Figure 2 and Figure 3 In the text, the casing 7 is omitted. (See reference...) Figure 2 and Figure 3The accessory 10 in this embodiment includes: an accessory body 1; a fixing screw 2, installed inside the accessory body 1; a sensor part 3, installed on the outer peripheral surface of the accessory body 1; and a housing 7. (Refer to...) Figure 1 Accessory 10 is disposed between tool mounting part 6 and tool holder 4, thereby enabling tool mounting part 6 and tool holder 4 to be connected.

[0046] Example of accessory 10 includes an extension and an adapter. The extension is disposed between the tool mounting portion 6 and the tool holder 4, thereby increasing the distance between the tool mounting portion 6 and the tool holder 4 compared to the case where the tool holder 4 is directly mounted to the tool mounting portion 6. In the extension, the outer peripheral surface of the portion (handle 12) that inserts into the tool mounting portion 6 has the same shape as the inner peripheral surface 141 of the grip portion surrounded by the insertion hole 15 into which the handle 41 of the tool holder 4 is inserted. By disposing the adapter between the tool mounting portion 6 and the tool holder 4, which has a handle 41 that cannot be directly mounted to the tool mounting portion 6, the tool holder 4 can be mounted to the tool mounting portion 6. In the adapter, the outer peripheral surface of the portion (handle) that inserts into the tool mounting portion 6 has a different shape than the inner peripheral surface 141 of the grip portion surrounded by the insertion hole 15 into which the handle 41 of the tool holder 4 is inserted. The term "different shape" here also includes similar shapes. That is, the adapter also includes a reduction adapter. In this embodiment, the extension is used as an example of accessory 10.

[0047] In this disclosure, "same" includes the meaning that the objects being compared are identical to each other, and is not "same" in the strict sense. In this disclosure, "different" means anything other than the objects being compared being identical to each other.

[0048] (Structure of accessory body 1) The main body 1 connects the tool mounting section 6 to the tool holder 4. (See reference...) Figure 3 The accessory body 1 includes a base 11, a handle 12 protruding from the base 11 in a first direction D1, and a gripping part 13 protruding from the base 11 in a second direction D2. The handle 12, the base 11, and the gripping part 13 are arranged sequentially along the second direction D2. For example, metal can be used as the material for the accessory body 1. Examples of metals include aluminum alloys and iron alloys (such as stainless steel).

[0049] The base 11 is the portion that supports the handle 12 and the grip 13. The base 11 extends along the second direction D2 from the first end 114 to the second end 115. The base 11 is formed in a cylindrical shape. The central axis of the base 11 coincides with the rotation axis R1 of the main shaft. The outer diameter of the first end 114 is the same as the outer diameter of the second end 115. The diameter of the outer circumferential surface of the base 11 (hereinafter, the outer circumferential surface 111 of the base) is constant from the first end 114 to the second end 115.

[0050] The outer peripheral surface 111 of the base may not be cylindrical. Viewed from the second direction D2, the outer peripheral surface 111 of the base may also be a polygon such as a quadrilateral, pentagon, or hexagon. The diameter of the outer peripheral surface 111 of the base may not be constant from the first end 114 to the second end 115, and may have a shape such as a neck or a protrusion between the first end 114 and the second end 115.

[0051] Reference Figure 2 At least one groove 112 is formed on the outer peripheral surface 111 of the base. The base 11 according to this embodiment has multiple grooves 112. These grooves 112 are shaped to hook a replacement arm in an automatic tool changer (ATC). After the replacement arm is inserted into a groove 112, it moves in a first direction D1 or a second direction D2, thereby allowing the accessory 10 to be attached to or detached from the tool mounting portion 6. Each groove 112 is formed along the outer peripheral surface 111 of the base on a virtual plane orthogonal to the first direction D1 (second direction D2). That is, the groove 112 is formed along the intersection of the virtual plane orthogonal to the first direction and the outer peripheral surface 111 of the base. The multiple grooves 112 according to this embodiment are intermittently formed at certain intervals along a third direction R3 on the outer peripheral surface 111 of the base.

[0052] The base 11 can also be configured to have only one slot 112. The slot 112 can be formed along the entire length of the third direction R3 on the outer peripheral surface 111 of the base, or it can be continuous along the third direction R3 but only partially interrupted. That is, the slot 112 can be annular or C-shaped. As an automatic tool changer, it can be a turret-type automatic tool changer, a tool magazine-type automatic tool changer, or a robotic arm located inside or outside the device.

[0053] The handle 12 is the part that is mounted on the tool mounting part 6. (See reference...) Figure 3 The handle 12 is formed into a cylindrical shape. Here, Figure 4 This is a rough top view of accessory 10 viewed along the second direction D2. (Refer to...) Figure 4 The handle 12 of this embodiment, when viewed from the second direction D2, has a circular inner circumferential surface 122 and a non-circular outer circumferential surface 123. The handle 12 has three protrusions 121 that project radially at 120 degrees, starting from a virtual circle K2 concentric with the inner circumferential surface 122. The diameter of the virtual circle K2 is larger than that of the inner circumferential surface 122. The front end face of each protrusion 121 is curved. Because the handle 12 has three protrusions 121, the outer circumferential surface 123 is formed in the shape of a so-called Luro triangle when viewed from the second direction D2. When viewed from the second direction D2, the outer circumferential surface 123 of this embodiment is formed in a shape with threefold rotational symmetry.

[0054] The outer peripheral surface 123 of the handle 12 may include a surface parallel to the first direction D1, or it may include a conical surface that approaches the rotation axis R1 as it moves along the first direction D1. In this embodiment, the outer peripheral surface 123 of the handle 12 is composed of a conical surface that approaches the rotation axis R1 as it moves along the first direction D1. Examples of the slope of the conical surface include a 7 / 24 cone and a 1 / 10 cone.

[0055] The maximum distance L1 between the end of the outer peripheral surface 123 of the handle 12 in the second direction D2 and the rotation axis R1 (the central axis of the accessory body 1) is shorter than the minimum distance L2 between the outer edge of the first end 114 of the base 11 and the rotation axis R1. Therefore, the first end 114 of the base 11 has a surface orthogonal to the rotation axis R1 (hereinafter referred to as the flange surface 113). When the accessory 10 is installed in the tool mounting part 6, the flange surface 113 faces the tool mounting part 6. At this time, the outer peripheral surface 123 of the handle 12 contacts the inner peripheral surface of the insertion opening 61, and the flange surface 113 contacts the end face of the tool mounting part 6 in the second direction D2. Thus, the accessory 10 is installed in the tool mounting part 6 by constraint on both surfaces. The installation of the accessory 10 relative to the tool mounting part 6 may also be constrained only by the contact between the outer peripheral surface 123 of the handle 12 and the inner peripheral surface of the insertion opening 61, that is, there may be a gap between the flange surface 113 and the tool mounting part 6.

[0056] Reference Figure 3 The grip portion 13 is the part that holds the handle 41 of the tool holder 4. The grip portion 13 has an outer peripheral wall 14 and an insertion hole 15 for inserting the tool holder 41. The outer peripheral wall 14 protrudes from the second end 115 of the base 11 in a second direction D2. The outer peripheral wall 14 has an inner peripheral surface (hereinafter referred to as the grip inner peripheral surface 141), an outer peripheral surface (hereinafter referred to as the grip outer peripheral surface 142), and a contact surface 143. In this disclosure, "outer peripheral surface of accessory body 1" and "outer peripheral surface included in accessory body 1" refer to the surface formed by the outer peripheral surface 111 of the base and the outer peripheral surface 142 of the grip, excluding the outer peripheral surface 123 of the handle portion 12.

[0057] Figure 5 This is a rough bottom view of accessory 10 viewed from the first direction, D1. (Refer to...) Figure 5 When the insertion hole 15 is viewed in the first direction D1, the inner peripheral surface 141 of the gripping portion has a non-circular shape. The inner peripheral surface 141 of the gripping portion of the insertion hole 15 according to this embodiment has a so-called Luró triangle shape when viewed along the first direction D1. That is, when viewed from the first direction D1, the shape of the inner peripheral surface 141 of the gripping portion surrounding the insertion hole 15 is a three-fold rotationally symmetric shape.

[0058] The inner peripheral surface 141 of the grip portion may include a surface parallel to the first direction D1, or it may include a conical surface that approaches the rotation axis R1 as it moves towards the second direction D2. In this embodiment, the inner peripheral surface 141 of the grip portion is formed by a conical surface that approaches the rotation axis R1 as it moves towards the second direction D2. The slope of the conical surface is similar to that of the outer peripheral surface 123 of the handle portion 12, for example, a 7 / 24 cone or a 1 / 10 cone. In this embodiment, the inner peripheral surface 141 of the grip portion surrounding the insertion hole 15 is formed with the same shape as the outer peripheral surface of the handle portion 12.

[0059] Reference Figure 3 The outer peripheral surface 142 of the grip portion is formed in a cylindrical shape. The diameter of the outer peripheral surface 142 of the grip portion is the same as the outer diameter of the base 11. The contact surface 143 is the end face of the grip portion 13 in the second direction D2. The contact surface 143 is orthogonal to the second direction D2. When the handle 41 of the tool holder 4 is inserted into the insertion hole 15, the contact surface 143 contacts the flange surface of the tool holder 4. Thus, the grip portion 13 can retain the tool holder 4 by the constraint of both the inner peripheral surface 141 of the grip portion forming the insertion hole 15 and the contact surface 143.

[0060] Reference Figure 5 The thickness of the outer peripheral wall 14 changes continuously along the third direction R3. The thickness of the outer peripheral wall 14 refers to the distance from the inner peripheral surface 141 to the outer peripheral surface 142 of the grip portion in the radial direction (hereinafter, sometimes referred to as "radial") of the outer peripheral surface 142 of the grip portion. Viewed from the first direction D1, the thickness L3 of the portion P1 in the outer peripheral wall 14 corresponding to the vertex P2 of the insertion hole 15 is thinner than other portions. That is, the portion P1 in the outer peripheral wall 14 with the minimum thickness is the portion corresponding to the vertex P2 of the insertion hole 15 when viewed from the first direction D1.

[0061] Reference Figure 3 The outer peripheral wall 14 has a placement portion 144 for arranging the sensor element 31. In this embodiment, the placement portion 144 is recessed in the outer peripheral surface 142 of the grip portion compared to other portions. Because the placement portion 144 is recessed, the position where the sensor element 31 should be placed is easily determined. However, the placement portion 144 may not be recessed in the outer peripheral surface 142 of the grip portion; for example, it may be formed by printed markings.

[0062] Reference Figure 5The placement portion 144 is offset in a third direction R3 relative to the portion P1 in the outer peripheral surface 142 of the gripping portion, which has the minimum thickness of the outer peripheral wall 14. In this case, it is preferable that the entire area of ​​each placement portion 144 is away from portion P1. This allows the sensor element 31 to be placed at a position offset from portion P1 in the gripping portion 13, rather than at the thinnest portion P1. However, the placement portion 144 may also be formed in a position in the outer peripheral surface 142 of the gripping portion that overlaps with portion P1. A portion of the plurality of placement portions 144 may also be formed in a position in the outer peripheral surface 142 of the gripping portion that overlaps with portion P1.

[0063] Insertion hole 15 is the space for inserting handle 41. (See reference...) Figure 3 The insertion hole 15 is formed by the end face of the second end portion 115 of the base 11 (hereinafter, sometimes referred to as the bottom face 151) and the inner peripheral surface 141 of the grip portion. The end face of the insertion hole 15 in the second direction D2 is an open face. When the handle 41 of the tool holder 4 is inserted into the insertion hole 15 through the open face, the bottom face 151 of the hole faces the end face of the handle 41 in the first direction D1. A through hole 152 for the passing of the fixing screw 2 is formed in the bottom face 151. The through hole 152 extends from the bottom face 151 to the end face of the handle 12 in the first direction D1.

[0064] Reference Figure 3 The base 11 has a position limiting portion 116 that rotatably holds the fixing screw 2. The position limiting portion 116 is formed on the inner peripheral surface of the through hole 152. The position limiting portion 116 in a cross section orthogonal to the first direction D1 is circular. The diameter of the position limiting portion 116 is larger than the diameter of the through hole 152. The position limiting portion 116 is formed in the base 11 between the second end 115 and the first end 114.

[0065] (Structure of fixing screw 2) The fixing screw 2 secures the tool holder 4 to the accessory body 1. (Refer to...) Figure 3 The fixing screw 2 has a shaft portion 21 and a head 22. Viewed from the second direction D2, the head 22 is circular in shape. The outer diameter of the head 22 is larger than the outer diameter of the shaft portion 21. A rotating hole 221 is formed in the head 22. The rotating hole 221 is formed on the end face of the head 22 in the first direction D1. The rotating hole 221 may have a polygonal shape, such as a triangle, quadrilateral, pentagon, or hexagon. The head 22 of the fixing screw 2 is received in the position limiting portion 116, and the shaft portion 21 protrudes into the insertion hole 15 through the through hole 152. Thus, the fixing screw 2 is rotatably mounted on the accessory body 1.

[0066] A thread 211 is formed on the shaft portion 21. The handle 41 is inserted into the insertion hole 15, and the retaining screw 2 is rotated, thereby fixing the handle 41 relative to the accessory body 1. Thus, the tool holder 4 can be mounted on the accessory 10.

[0067] The accessory 10 has a cooling passage 16 formed along its central axis. In this embodiment, the cooling passage 16 extends from the front end face of the shank 12 (which is the front end face in the first direction D1), through the base 11 and the fixing screw 2, to the front end face of the fixing screw 2 in the second direction D2. When the tool holder 4 is connected to the accessory 10, the cooling passage 16 communicates with the flow path formed in the tool holder 4. This allows cooling water supplied from the machine tool to be supplied to the tip of the cutting tool 5.

[0068] (Structure of sensor section 3) The sensor unit 3 has at least one sensor element 31 that detects the physical quantity of the accessory body 1. (Refer to...) Figure 2 The sensor unit 3 is mounted on the accessory body 1. In this embodiment, the sensor unit 3 is mounted on the outer peripheral surface of the accessory body 1, but it can also be disposed in the accessory body 1 between the outer peripheral surface 142 and the inner peripheral surface 141 of the grip, or it can be mounted on the inner peripheral surface 141 of the grip. In addition to at least one sensor element 31, the sensor unit 3 also includes multiple substrates 32, a power supply unit 33, an AD converter 34, and a wireless communication unit 35.

[0069] Examples of sensor elements 31 include force sensor elements, temperature sensor elements, acceleration sensor elements, and AE (Acoustic Emission) sensor elements. When using multiple sensor elements 31, two or more sensor elements 31 are selected from force sensor elements, temperature sensor elements, acceleration sensor elements, and AE sensor elements. The acceleration sensor element detects the acceleration of the accessory body 1 as a physical quantity, and the elastic waves generated in the accessory body 1. The AE sensor element detects the elastic waves generated in the accessory body 1 as a physical quantity of the accessory body 1. Elastic waves can be generated by, for example, cracking, wear, vibration, or deformation in the accessory body 1. The force sensor element detects the force applied to the accessory body 1 as a physical quantity of the accessory body 1. Based on the force sensor element, the strain generated in the accessory body 1 can be measured. The force sensor element can be a strain sensor element or a piezoelectric stress sensor element. The temperature sensor element detects heat as a physical quantity of the accessory body 1.

[0070] Reference Figure 3The sensor element 31 is mounted on the outer peripheral surface 142 of the gripping portion 13. A virtual plane K1, orthogonal to the first direction D1 and intersecting the sensor element 31, also intersects the insertion hole 15. In other words, the sensor element 31 is arranged radially relative to the insertion hole 15. It is assumed that there are multiple virtual planes K1 intersecting the sensor element 31, but in this embodiment, all virtual planes K1 intersecting the sensor element 31 intersect the insertion hole 15. However, in this disclosure, at least one of the virtual planes K1 intersecting the sensor element 31 may intersect the insertion hole 15.

[0071] The sensor element 31 includes a detection area 312 and a connection portion 313 electrically connected to the detection area 312. In this embodiment, the detection area 312 in each sensor element 31 is disposed in the placement portion 144. The virtual plane K1 intersects the insertion hole 15 and the detection area 312. The detection area 312 refers to the area in which the physical quantity of the accessory body 1 is input into the sensor element 31. For example, when the sensor element 31 is a strain sensor element, the detection area 312 is a grid portion in a metal foil resistive element, and the connection portion 313 is a strain gauge lead. For example, when the sensor element 31 is a piezoelectric accelerometer element, the detection area 312 is a piezoelectric element, and the connection portion 313 is a lead. For example, when the sensor element 31 is a piezoelectric resistor accelerometer element, the detection area 312 is a piezoelectric resistive element, and the connection portion 313 is a lead.

[0072] With this configuration, when using an acceleration sensor element as sensor element 31, the sensor element 31 is positioned in the main body 1 at a location corresponding to the hollow portion where the cross-sectional moment of inertia is smaller than the thickness (base 11). Therefore, in the main body 1, the sensor element 31 can be positioned at a location where the amount of deflection is more likely to increase. Thus, according to this structure, the acceleration sensor element can easily detect at least one of the vibration and deflection generated in the accessory 10.

[0073] When the inner peripheral surface 141 of the holding portion surrounding the insertion hole 15 of the fitting 10 includes a conical surface that approaches the rotation axis R1 as it advances along the first direction D1, the shank 41 of the tool holder 4 can sometimes be inserted even if foreign objects such as chips adhere to the periphery of the opening of the insertion hole 15. In this case, the accuracy of the formed part is compromised because the position of the tip of the cutting tool 5 deviates from its designed position, and vibrations caused by rotation are easily generated in the cutting tool 5 and the tool holder 4. However, by mounting at least one of the accelerometer element or the AE sensor element to the fitting 10, elastic waves generated when foreign objects are stuck between the shank 41 and the insertion hole 15 can be detected. If at least one of the accelerometer element or the AE sensor element is arranged radially relative to the insertion hole 15, the distance to the origin of the elastic wave is shortened, thereby reducing the attenuation of the elastic wave and further increasing the signal-to-noise ratio (SN ratio). As a result, the occurrence of abnormalities in the fitting 10 can be detected earlier.

[0074] When using a force sensor element as sensor element 31, the force sensor element is positioned at a location where the thickness is thinner than the base 11. That is, the force sensor element can be positioned in a location within the main body 1 where strain is easily generated. Therefore, with this structure, it is easy to use a force sensor element to improve the accuracy of measuring the strain generated in the accessory 10.

[0075] When a temperature sensor element is used as sensor element 31, the temperature sensor element is arranged radially relative to the insertion hole 15, thus enabling proper detection of heat conducted from the tool holder 4. That is, if cooling water passes through the cooling path 16, the base 11 and the fixing screw 2 are cooled by the cooling water, but the outer peripheral wall 14 of the grip portion 13, which is not in direct contact with the cooling path 16, is less affected by the cooling water. As a result, by arranging the temperature sensor element on the outer peripheral surface 142 of the grip portion, the influence of the cooling water can be reduced, and heat conducted from the tool holder 4 can be properly detected.

[0076] Reference Figure 2 Multiple substrates 32 are electrically connected to sensor elements 31. The multiple substrates 32 are mounted along the outer peripheral surface of the accessory body 1. The mounting of the substrates 32 to the accessory body 1 is performed, for example, by adhesive bonding or threaded fixing. The sensor element 31 is disposed in a region further along the second direction D2 than the substrates 32. The multiple substrates 32 are electrically connected to each other via wiring 36. In this embodiment, the detection regions 312 of the multiple sensor elements 31 are arranged at intervals along the second direction D2 relative to the end edges of the multiple substrates 32 located furthest along the second direction D2. With this configuration, the sensor elements 31 can be disposed on the outer peripheral surface 142 of the holding portion instead of on the substrates 32. In this embodiment, all substrates 32 are disposed along the base outer peripheral surface 111 of the accessory body 1.

[0077] The substrate 32 is disposed along the outer peripheral surface 111 of the base, but it may also be disposed along the outer peripheral surface 142 of the gripping portion. Alternatively, the substrate 32 may be disposed across the outer peripheral surface 111 of the base and the outer peripheral surface of the gripping portion 13. The accessory 10 may have multiple substrates 32, but it may also have only one substrate 32.

[0078] The power supply unit 33 is electrically connected to the substrate 32 via wiring 36, supplying power to the sensor element 31. In this embodiment, the power supply unit 33 is a rechargeable battery. The power supply unit 33 is not limited to a rechargeable battery; for example, it can be a primary battery or a capacitor. The power supply unit 33 is detachably held in a holder 331 mounted on the outer peripheral surface of the accessory body 1.

[0079] The AD converter 34 converts the electrical signal (hereinafter, sometimes referred to as the detection signal) generated by the sensor element 31 into a digital signal. The detection signal is input to the wireless communication unit 35 via the AD converter 34. The wireless communication unit 35 is a wireless communication module mounted on the substrate 32. The wireless communication unit 35 is electrically connected to the sensor element 31 and is capable of receiving the digital signal converted from the detection signal. The wireless communication unit 35 transmits the digital signal input from the AD converter 34 to the outside. That is, the wireless communication unit 35 is capable of transmitting the signal generated by the sensor element 31 to the outside.

[0080] (Structure of shell 7) Figure 6 This is a cross-sectional view of accessory 10 with housing 7 installed on accessory body 1, and includes... Figure 1 A cross-sectional view along the CC line. Figure 6 In the image, a portion of the main body of accessory 1 is omitted. (See reference...) Figure 6 The housing 7 is mounted on the outer peripheral surface of the accessory body 1. At least one sensor element 31 is housed within the housing 7. In this embodiment, the housing 7 houses a sensor unit 3 (multiple sensor elements 31, multiple substrates 32, a power supply unit 33, an AD converter 34, and a wireless communication unit 35). Materials constituting the housing 7 include, for example, synthetic resin and metal. Examples of metals include aluminum alloys and iron alloys (such as stainless steel). The housing 7 is detachably mounted on the outer peripheral surface of the accessory body 1. Mounting of the housing 7 relative to the outer peripheral surface of the accessory body 1 can be achieved, for example, by threaded fastening, snap-fitting, insertion, or bonding.

[0081] When the material of the housing 7 is a material with high electromagnetic shielding (e.g., aluminum alloy, iron alloy), a portion of the housing 7 can be made of a material with lower electromagnetic shielding than other portions (a material with high electromagnetic transmittance). Examples of materials with low electromagnetic shielding include synthetic resin, pulp, rubber, wood, and cloth. Thus, even if the wireless communication unit 35 is covered by the housing 7, the reduction in communication performance (reduction in electromagnetic wave intensity) can be mitigated.

[0082] Reference Figure 6 The housing 7 has a first housing portion 71 for accommodating multiple sensor elements 31, multiple substrates 32, an AD converter 34, and a wireless communication unit 35, and a second housing portion 72 for accommodating a power supply unit 33. The first housing portion 71 communicates with the second housing portion 72. The interior of the housing 7 forms a sealed space separated from the space outside the housing 7.

[0083] When viewed along the second direction D2, the first receiving portion 71 is formed in the shape of an arc cross-section. The first receiving portion 71 is arranged at intervals relative to the outer peripheral surface of the accessory body 1. A plurality of sensor elements 31, a plurality of substrates 32, an AD converter 34, and a wireless communication unit 35 are arranged in the space between the outer peripheral surface of the accessory body 1 and the first receiving portion 71. The second receiving portion 72 protrudes radially outward from the first receiving portion 71. An opening is formed on the protruding front end surface of the second receiving portion 72, and the opening is closed by a cover 721 in an openable and closable manner. A power supply unit 33 is arranged in the space between the outer peripheral surface of the accessory body 1 and the second receiving portion 72. When the cover 721 is removed from the opening, the power supply unit 33 can be removed through the opening. According to the housing 7 of this embodiment, by removing the cover 721 from the opening, the power supply unit 33 can be replaced without disassembling the entire housing 7.

[0084] Accessory 10 also includes a sealing portion 37 disposed between the outer peripheral surface of accessory body 1 and the outer edge of housing 7. (See reference...) Figure 2 The sealing portion 37 at least surrounds the sensor element 31. In this embodiment, the sealing portion 37 surrounds multiple sensor elements 31, multiple substrates 32, a power supply unit 33, an AD converter 34, and a wireless communication unit 35. This configuration reduces the amount of liquid (e.g., oil, water) that seeps into the housing 7. Examples of materials that can be used for the sealing portion 37 include rubber and soft resin. Examples of rubbers include ethylene propylene rubber, polyurethane rubber, silicone rubber, and fluororubber.

[0085] The interior of the first receiving section 71 can also be filled with filler material while the sensor element 31 and other components are installed. Thus, the sensor element 31 and other components are fixed not only to the outer peripheral surface of the accessory body 1 but also to the housing 7. By fixing the sensor element 31 and other components to the outer peripheral surface of the accessory body 1 and the housing 7, the effect of centrifugal force can be reduced even if the accessory 10 rotates. The interior of the second receiving section 72 may not be filled with filler material. Therefore, it is less likely to hinder the replacement of the power supply section 33.

[0086] (action) Reference Figure 1 When the spindle rotates around the rotation axis R1, the accessory 10 rotates in either the third direction R3 or the fourth direction R4. Consequently, the tool holder 4 rotates along with the accessory 10. By bringing the cutting tool 5, mounted on the tool holder 4, into contact with the workpiece, the workpiece is machined. At this time, physical quantities such as strain and temperature generated in the accessory 10 are detected by the sensor element 31. This information, which is an analog signal, is converted into a digital signal in the AD converter 34 and then transmitted externally via the wireless communication unit 35. This signal is received and analyzed externally. The state of the cutting tool 5 is determined by analyzing the physical quantities generated in the accessory 10.

[0087] (First variation) When a force sensor element is used as sensor element 31, accessory 10 can also be formed as follows. The sensor element 31 involved in this modification is a force sensor element 311, and more specifically, a strain sensor element.

[0088] Figure 7 This is a schematic perspective view showing the structure of accessory 10 involved in the modified example. Figure 8 This is a schematic cross-sectional view of the base 11 and the holding part 13 in the accessory 10 involved in the modified example. Figure 9 yes Figure 8 A simplified enlarged view of part A in the diagram. Figure 10 This is a general bottom view of the accessory 10 involved in the modified example, viewed from the first direction D1. Figure 11 This is a schematic cross-sectional view showing the state in which the housing 7 is installed in the accessory 10 involved in the modified example, schematically indicating that it includes... Figure 7 The cross-section of the DD line. In Figure 11 The diagram primarily shows a schematic cross-sectional view of the base 11, the gripping part 13, and the housing 7. Figures 7 to 10 In the diagram, the shell 7 is omitted.

[0089] Reference Figures 7 to 9The outer peripheral surface 142 of the gripping part has a slit 145 formed along an arc centered on the rotation axis R1. The slit 145 is formed along a third direction R3 and a fourth direction R4. (See reference...) Figure 8 The minimum distance L4 between the bottom surface of slit 145 and the rotation axis R1 is shorter than the minimum distance L5 between the bottom surface of configuration part 144 and the rotation axis R1. (Refer to...) Figure 9 The depth DP2 of the slit 145 from the outer peripheral surface 142 of the gripping part is deeper than the depth DP1 of the arrangement part 144 from the outer peripheral surface 142 of the gripping part. (Refer to...) Figure 7 The slit 145 is formed around the entire circumference of the third direction R3 on the outer peripheral surface 142 of the holding part, forming a ring shape. The slit 145 may also be interrupted in part of the third direction R3, that is, it may also be formed in a C shape. The slit 145 may be formed continuously or intermittently along the third direction R3.

[0090] Reference Figure 9 The detection area 312 in the force sensor element 311 is mounted within the configuration section 144 in a manner that spans the slit 145. (Refer to...) Figure 10 When viewed along the first direction D1, the angle θ1 formed by the line segment connecting the detection area 312 in each force sensor element 311 and the rotation axis R1 is 90 degrees. That is, the multiple force sensor elements 311 are arranged at 90-degree intervals when viewed along the first direction D1. With this configuration, the force sensor elements 311 can easily and appropriately detect the strain generated in the fitting 10.

[0091] In this variant, the power supply unit 33 consists of two rechargeable batteries 332. (See reference...) Figure 10 In the first variation, the power supply units 33 are arranged at intervals on the outer periphery of the accessory body 1. When the accessory 10 is viewed along the first direction D1, the angle θ2 formed by the line segments connecting the centers of the power supply units 33 and the rotation axis R1 is 90 degrees. That is, multiple power supply units 33 are arranged at intervals along the third direction R3. With this configuration, the center of gravity of the accessory 10 is easily located on the rotation axis R1. Therefore, by adopting the accessory 10 according to the first variation, stable rotation can be obtained, and the deterioration of balance during rotation can be reduced.

[0092] Reference Figure 11 The housing 7 has an annular fixing member 73 and a cylindrical cover member 74 that are fixed relative to the accessory body 1. The housing 7 is a rotating body centered on the rotation axis R1 of the accessory body 1. Therefore, the accessory 10 involved in this modification can rotate stably even if the housing 7 is installed on the accessory body 1, and the deterioration of balance during rotation can be reduced.

[0093] The fixing member 73 has an inner peripheral surface facing the outer peripheral surface of the accessory body 1. In this modified example, the fixing member 73 is fixed relative to the outer peripheral surface of the accessory body 1 by placing an O-ring 371, which serves as a sealing part 37, between the inner peripheral surface of the fixing member 73 and the outer peripheral surface of the accessory body 1. The fixing member 73 can also be fixed to the outer peripheral surface of the accessory body 1 by pressing. The fixing member 73 has a plurality of through holes 731 penetrating both end faces in the first direction D1. Threaded parts 75 are inserted into the plurality of through holes 731 respectively.

[0094] The cover member 74 covers the sensor section 3 (multiple sensor elements 31, multiple substrates 32, power supply section 33, AD converter 34, and wireless communication section 35). The cover member 74 has a cylindrical outer peripheral portion 741, a first mounting portion 742 that protrudes taperedly from the end of the outer peripheral portion in a second direction D2, and a second mounting portion 743 that protrudes toward the central axis from the end of the outer peripheral portion in a first direction D1. In the first mounting portion 742, an internal thread 744 is formed in the portion opposite to the accessory body 1. The internal thread 744 is configured to be screwed into an external thread 146 formed on the outer peripheral surface (outer peripheral surface 142 of the gripping portion) of the accessory body 1. When the internal thread 744 of the first mounting portion 742 is screwed into the external thread 146 of the accessory body 1, the second mounting portion 743 is adjacent to the fixing member 73. The second mounting portion 743 has multiple threaded holes 745 formed at positions corresponding to the multiple through holes 731 of the fixing member 73. With the internal thread 744 of the first mounting part 742 screwed into the external thread 146 of the accessory body 1, the threaded part 75, passing through the through hole 731 of the fixing member 73, is screwed into the threaded hole 745 of the second mounting part 743. Thus, the housing 7 is mounted on the outer peripheral surface of the accessory body 1.

[0095] (Other variations) In this implementation, when viewed from the second direction D2, the right-handed direction is set as the third direction R3, and the left-handed direction is set as the fourth direction R4. However, the fourth direction R4 can also be set as the right-handed direction when viewed from the second direction D2, and the third direction R3 can be set as the left-handed direction when viewed from the second direction D2.

[0096] In this embodiment, the use of any one of the force sensor element, acceleration sensor element, and temperature sensor element 31 is described. However, multiple sensor elements 31 selected from the force sensor element, acceleration sensor element, and temperature sensor element may also be used as sensor elements 31. For example, a force sensor element may be used as the first sensor element, and a temperature sensor element as the second sensor element. Alternatively, an acceleration sensor element may be used as the first sensor element, and a temperature sensor element as the second sensor element. Furthermore, a force sensor element may be used as the first sensor element, and an acceleration sensor element as the second sensor element. As the sensor element 31 included in the sensor unit 3, sensor elements 31 that detect other physical quantities besides the force sensor element, acceleration sensor element, and temperature sensor element (e.g., a gyroscope sensor element) may also be used.

[0097] In the above embodiments, machine tools for milling operations have been mainly described, but the machine tool can be a multi-functional machining center, or a general-purpose lathe, NC lathe, or other lathes. That is, the tool mounting section 6 is not limited to a spindle. For example, in the case of a lathe, the tool mounting section 6 can also be a tool post. That is, the accessory 10 disclosed herein is not limited to the accessory 10 for a tool holder 4 used for milling tools, but can also be the accessory 10 for a tool holder 4 (including a tool holder and a boring bar) used for turning tools. As the cutting tool 5, a turning tool (including inserts) can also be used.

[0098] The sensor unit 3 may also include at least one of a switch and a variable resistor mounted on the substrate 32.

[0099] It should be understood that the embodiments disclosed herein are illustrative in all respects and are not limiting in any way. The scope of the invention is not limited to the foregoing description, but is defined by the claims, and is intended to include all modifications of the same meaning and scope as the claims.

[0100] Explanation of reference numerals in the attached figures 10: Accessory; 1: Accessory body; 11: Base; 111: Outer peripheral surface of base; 112: Groove; 113: Flange surface; 114: First end; 115: Second end; 116: Position limiting part; 12: Handle; 121: Protrusion; 122: Inner peripheral surface; 123: Outer peripheral surface; 13: Holding part; 14: Outer peripheral wall; 141: Inner peripheral surface of holding part; 142: Outer peripheral surface of holding part; 143: Contact surface; 144: Mounting part; 145: Slit; 146: External thread; 15: Insert 151: Bottom surface of hole; 152: Through hole; 16: Cooling passage; 2: Fixing thread; 21: Shaft; 211: Thread; 22: Head; 221: Rotation hole; 3: Sensor part; 31: Sensor element; 311: Force sensor element; 312: Detection area; 313: Connection part; 32: Base plate; 33: Power supply part; 331: Cage; 332: Rechargeable battery; 34: AD converter; 35: Wireless communication part; 36: Wiring; 37: Sealing part; 371 1: O-ring; 4: Tool holder; 41: Shank; 5: Cutting tool; 6: Tool mounting part; 61: Insertion opening; 7: Housing; 73: Fixing member; 731: Through hole; 74: Cover member; 741: Outer periphery; 742: First mounting part; 743: Second mounting part; 744: Internal thread; 745: Threaded hole; 75: Threaded part; K1: Virtual plane; K2: Virtual circle; P1: Location; P2: Vertex; R1: Rotation axis; D1: First direction; D2: Second direction; R3: Third direction; R4: Fourth direction.

Claims

1. An attachment of a tool holder, wherein the attachment of the tool holder is provided with: an attachment main body that connects a tool mounting portion included in a machine tool and the tool holder; and a sensor portion that is mounted to the attachment main body and has at least one sensor element that detects a physical quantity of the attachment main body.

2. The tool holder assembly of claim 1, wherein, The sensor portion further has a wireless communication portion that transmits, to the outside, a signal generated in accordance with detection by the sensor element.

3. An accessory for a tool holder according to claim 1 or 2, wherein, The sensor portion further has a power supply portion that supplies power to the sensor element.

4. The tool holder assembly of any one of claims 1 to 3, wherein, The attachment is further provided with a housing that accommodates the at least one sensor element.

5. The tool holder assembly of claim 4, wherein, The attachment is further provided with a sealing portion that surrounds the at least one sensor element between an outer peripheral surface of the attachment main body and the housing.

6. The attachment of the tool holder according to any one of claims 1 to 5, wherein the attachment main body has: a base portion; a shank portion that protrudes from the base portion in a first direction toward the tool mounting portion from the tool holder and is mounted to the tool mounting portion; and a grip portion that protrudes from the base portion in a second direction toward the tool holder from the tool mounting portion and includes an insertion hole into which a shank of the tool holder is inserted, an outer peripheral surface of the shank portion includes a tapered surface that approaches a central axis as it advances in the first direction.

7. The attachment of the tool holder according to any one of claims 1 to 6, wherein the attachment main body has: a base portion; a shank portion that protrudes from the base portion in a first direction toward the tool mounting portion from the tool holder and is mounted to the tool mounting portion; and a grip portion that protrudes from the base portion in a second direction toward the tool holder from the tool mounting portion and includes an insertion hole into which a shank of the tool holder is inserted, an inner peripheral surface that surrounds the insertion hole includes a tapered surface that approaches a central axis as it advances in the first direction.

8. An accessory for a tool holder according to claim 6 or 7, wherein, A virtual plane that is orthogonal to the second direction and that intersects the at least one sensor element intersects the insertion hole.

9. The attachment of the tool holder according to claim 8, wherein the at least one sensor element includes a region, i.e., a detection region, into which the physical quantity is input, the virtual plane that intersects the detection region intersects the insertion hole.

10. An accessory for a tool holder according to any one of claims 1 to 9, wherein, A recess is formed in an outer peripheral surface of the attachment main body into which at least a portion of the at least one sensor element is disposed.

11. The attachment of the tool holder according to any one of claims 1 to 10, wherein the sensor portion further has: a substrate; and a wiring that electrically connects the substrate and the at least one sensor element, the at least one sensor element is disposed in a region that is in a second direction toward the tool holder from the tool mounting portion with respect to the substrate.

12. The attachment of the tool holder according to claim 8 or 9, wherein the grip portion has a disposition portion into which the at least one sensor element is disposed and that is recessed from an outer peripheral surface in the grip portion, a thickness between an outer peripheral surface included in the grip portion and an inner peripheral surface surrounding the insertion hole is configured to vary in a third direction along an intersection line of the virtual plane and the inner peripheral surface, the configuration portion is formed at a position offset in the third direction with respect to a portion of the outer peripheral surface included in the grip portion that corresponds to a minimum value of the thickness.

13. An accessory for a tool holder according to any one of claims 1 to 12, wherein, The at least one sensor element includes a force sensor element.

14. The accessory for a tool holder according to any one of claims 1 to 13, wherein, The at least one sensor element includes an acceleration sensor element or an AE sensor element.

15. An accessory for a tool holder according to any one of claims 1 to 14, wherein, The at least one sensor element includes a temperature sensor element.

16. The tool holder accessory of claim 8 or 9, wherein, the accessory body has a slit in an outer peripheral surface included in the accessory body formed along an intersection line of the virtual plane and the outer peripheral surface, the at least one sensor element includes a force sensor element mounted in a manner spanning the slit.

17. An accessory for a tool holder according to any one of claims 6 to 9, wherein, The outer peripheral surface of the shank portion and the inner peripheral surface surrounding the insertion hole are the same shape.

18. An accessory for a tool holder according to any one of claims 6 to 9, wherein, The outer peripheral surface of the shank portion and the inner peripheral surface surrounding the insertion hole are different shapes.

Images