Attachment, body, and cutting tool

Abstract

An attachment (100) attached to a cutting tool is provided with: a base portion (1); and a leg portion (2) protruding from the base portion (1) and having a plurality of legs (21A, 21B) separated from each other. When surfaces of the plurality of legs (21A, 21B) facing each other are defined as inner surfaces (21N, 21N) and surfaces thereof opposite to the inner surfaces (21N, 21N) are defined as outer surfaces (21G, 21G), protrusions (25A, 25B) are provided on the outer surface (21G) of at least one of the plurality of legs (21A, 21B).

Description

Attachment, body, and cutting tool

[0001] The present disclosure relates to an attachment, a body to which the attachment is attached, and a cutting tool including them.

[0002] As an attachment attached to a body such as a holder that constitutes a part of a cutting tool, for example, Patent Documents 1 and 2 describe a clamp member for fixing a cutting insert to the holder. Further, for example, in Cited Documents 3 and 4, a nozzle and a discharge member attached to the holder for supplying a coolant to the cutting insert fixed to the holder are described.

[0003] Japanese Patent No. 6717950 Japanese Unexamined Patent Application Publication No. 2023-514726 Japanese Patent No. 7312243 Japanese Patent No. 7559650

[0004] Among the above conventional attachments, the clamp members described in Cited Documents 1 and 2 are provided with through-holes into which screws are inserted, and the holder is also provided with holes into which screws are inserted or screwed, and the clamp members are screwed to the holder by them. However, in such an attachment structure, since it is necessary to form a through-hole in the clamp member, the number of parts and the man-hours during manufacturing increase, and it is difficult to miniaturize the clamp member, the holder, and thus the cutting tool. On the other hand, although the nozzles and discharge members described in Cited Documents 3 and 4 are not provided with screw holes themselves, screws are still required to fix them to the holder. Therefore, since it is necessary to form a female screw portion into which the screw is screwed in the holder, the number of parts and the man-hours during manufacturing still increase, and there is a limit to miniaturizing the clamp member, the holder, and thus the cutting tool. In particular, in a cutting tool for performing micro machining, where the size of the attachment is required to be about several millimeters, it has been difficult to meet such a requirement with the above conventional screw fixing attachment structure.

[0005] Therefore, this disclosure is made in view of the above circumstances and aims to provide attachments, bodies, and cutting tools that can reduce the number of parts and manufacturing man-hours, and enable miniaturization.

[0006] [1] An example of an attachment according to the present disclosure is attached to a cutting tool and comprises a base portion and a leg portion having a plurality of legs that protrude from the base portion and are spaced apart from each other. When the faces of the plurality of legs facing each other are considered inner surfaces and the faces opposite the inner surfaces are considered outer surfaces, a protrusion is provided on at least one of the outer surfaces of the plurality of legs. In this disclosure, "attachment" refers to an auxiliary member or functional member that is attached to a basic part, basic component, device, etc., such as a "body," which is a component that mainly constitutes a cutting tool such as a turning tool, milling tool, or drilling tool, in order to express additional functions or uses, and is a concept that includes "parts" in general.

[0007] In such a configuration, for example, if a hole into which the attachment's legs are inserted is provided in the body of the cutting tool, and a "recess" or "step" (described later) into which the protrusions of the legs engage or fit is provided, for example, on the inner wall surface of the hole in the body, the attachment can be easily attached to the body without using the conventional screw fixing method. That is, in such a configuration, when the attachment's legs are inserted into the hole in the body, the protrusions of the legs engage or fit into the "recess" or "step" in the hole, thereby securing the attachment so that it does not easily come off the holder. More specifically, if the attachment's legs are elastically deformable, they can be elastically deformed to narrow the distance between the legs and inserted into the hole in the holder. When the legs are pushed further in and the protrusions of the legs reach the "recess" or "step" in the hole, the deformation of the legs returns to its original shape, and the protrusions of the legs engage or fit into the "recess" or "step" in the hole. Therefore, the attachment can be easily attached to the body and is difficult to detach.

[0008] [2] In the above configuration, the protrusion may be provided on the tip side of at least one of the lengths of the multiple legs, rather than at the midpoint (position). This makes it easier to ensure the elasticity of the multiple legs even if their lengths are shortened, which is useful in miniaturizing the attachment. Here, "length" refers to the length in the extending direction of the leg, that is, the distance from the base portion to the tip of the leg.

[0009] [3] In this case, if the protrusion is provided on the tip of at least one of the multiple legs, it becomes easier to impart elasticity to the multiple legs, making it easier to further miniaturize the attachment.

[0010] [4] In the above configuration, a locking structure may be provided for locking the attachment to the cutting tool (body). In this way, in addition to the legs of the attachment engaging with the holes in the body to fix them together, a separate locking structure can be used to position the attachment on the body or to suppress relative rotational movement between the attachment and the body.

[0011] [5] In this case, specifically, the body is also provided with a locking structure, and the locking structure of the attachment and the body may have a relationship where one is a "recess" and the other is a "convex," or it may be a separate part such as a key or pin. More specifically, an example is that the locking structure on the attachment side is a convex that protrudes from the base portion in the same direction as the legs and has a length shorter than the length of at least one of the multiple legs, or a recess which is the inverse structure of the convex. In this case, the locking structure on the body side may be a structure into which the locking structure (convex or concave) on the attachment side is inserted. Furthermore, in this case, if the length of the convex or the depth of the concave in the locking structure is less than half the length of at least one of the multiple legs, it becomes easier to lock the attachment and the body, so the work of attaching the attachment to the body becomes easier and the effort involved can be reduced.

[0012] [6] In the above configuration, at least one of the inner and outer surfaces of the multiple legs, at least the outer surface, may have an outwardly bulging arc shape in a cross section or plane perpendicular to the direction in which the legs protrude. In this way, if the hole provided in the body is a circular hole, the outer surfaces of the multiple legs are arranged along the inner wall surface of the hole, narrowing the gap (clearance) between the multiple legs and the hole, or allowing them to come into contact. This makes it possible to suppress rattling and swinging of the attachment mounted on the body.

[0013] [7] In the above configuration, the base portion may have a first plane in at least a part of the region opposite to the side on which the legs are provided. There are no particular limitations on the method for manufacturing the attachment having the above configuration, but in order to miniaturize the attachment, for example, a powder bed method using a metal 3D printer is preferably used. In this case, from the viewpoint of maintaining the shape during manufacturing and ease of manufacturing, it is desirable to perform a procedure in which layers are formed from the base portion toward the legs. Therefore, if the first plane in the base portion of the attachment is used as the reference plane for forming the legs (starting plane for forming), and the legs are formed in a direction perpendicular to it, it is possible to suppress the deformation of the convex portion formed in the final stage due to the weight of its metal material.

[0014] [8] As a more specific configuration, an example can be given in which the first plane is perpendicular to the direction in which the leg protrusions are provided.

[0015] [9] In the above configuration, more specifically, the base portion may have a second plane from which the legs protrude, and the second plane may be perpendicular to the direction in which the legs protrude, or may be at an arbitrary angle with a plane perpendicular to the direction in which the legs protrude. The second plane, which is the starting point for the leg protrusion, may be perpendicular to the direction in which the legs protrude, similar to the first plane, for shaping purposes, but it may also be a plane with an arbitrary angle without such constraints. This allows the base portion to be made into any shape corresponding to its internal structure, for example, when the base portion has a specific internal structure (such as a flow path for the cooling material for the cutting edge).

[0016]

[10] In the above configuration, if the distance between the inner surfaces of the multiple legs is configured to gradually increase from the base portion toward the tip of the legs, the base portion of the multiple legs can be made thicker than the tip portion. Therefore, the strength (flexure resistance) of the multiple legs can be increased. Herein, "distance between the inner surfaces of the multiple legs" refers to the distance between the inner wall surfaces in a side view of the multiple legs facing each other, or in a cross-sectional view perpendicular to the direction of protrusion.

[0017]

[11] However, the configuration is not limited to such a configuration, and the distance between the inner surfaces of the multiple legs may be configured to gradually decrease from the base to the tip, thereby allowing the flexibility of the multiple legs to be adjusted or adapted to specific applications.

[0018]

[12] An example of a body according to the present disclosure is one to which an attachment according to the present disclosure is attached, and has a hole into which the legs of the attachment described above are inserted, and the inner wall surface of the hole is provided with a recess or step into which a protrusion provided on the legs of the attachment engages or fits. Here, "recess" can be, for example, a groove formed so as to engage or fit into the protrusion, and "step" can be a part having a stepped shape in which the cross-sectional area or width diameter perpendicular to the depth direction of the hole increases as it goes towards the depth, or a part with an inverted L-shaped cross-section.

[0019]

[13] Furthermore, there may be only one portion formed in each hole that engages with or fits into a protrusion.

[0020]

[14] In addition, it is preferable to provide the body with a locking structure for securing the attachments as described above.

[0021]

[15] Another example of a cutting tool according to the present disclosure is a body according to the present disclosure to which a cutting edge portion (a component capable of cutting the workpiece, such as a cutting insert) and an attachment according to the present disclosure are attached. In other words, a cutting tool according to the present disclosure comprises a body according to the present disclosure, an attachment according to the present disclosure attached to the body, and a cutting edge portion also attached to the body.

[0022] According to this disclosure, since screws are not required when attaching the attachment to the body, the number of parts and manufacturing time can be reduced, and the attachment, body, and ultimately the cutting tool can be miniaturized. As a result, it is possible to improve the economic efficiency and productivity when manufacturing the attachment and body.

[0023] This is a side view showing the attachment 100 according to this embodiment. This is a vertical cross-sectional view showing the attachment 100 shown in Figure 1 attached to the holder 200 according to this embodiment. This is a perspective view of the attachment 100 seen from the front Y1 towards the right X1 and slightly above Z1. This is a transparent perspective view corresponding to Figure 3. This is a bottom view showing the attachment 100. This is a front view showing the attachment 100. This is a side view showing the attachment 100 according to this embodiment, and corresponds to the state in Figure 1 inverted vertically. This is a schematic front view showing the cutting tool 1000 according to this embodiment.

[0024] This embodiment will be described below with reference to the attached drawings. To facilitate understanding of the description, the same reference numerals are used for identical components in each drawing whenever possible, and redundant descriptions are omitted. The following embodiments are illustrative examples for illustrating the present disclosure and are not intended to limit the present disclosure to these embodiments only. Furthermore, the present disclosure can be modified in various ways without departing from its essence. Moreover, those skilled in the art can adopt embodiments in which each of the elements described below is replaced with equivalent components, and such embodiments are also included within the scope of the present disclosure.

[0025] Figure 1 is a side view showing the attachment 100 according to this embodiment, and Figure 2 is a vertical cross-sectional view (a cross-sectional view along line II-II in Figures 3 to 6 described later) showing the attachment 100 attached to the holder 200 (corresponding to an example of a "body" in this disclosure) according to this embodiment.

[0026] In this disclosure, for convenience in indicating relative directions, the upward direction may be referred to as "upward Z1" and the opposite direction as "downward Z2" in the coordinate axes shown in Figures 1 and 2, and both of these directions may be collectively referred to as "upward-downward Z". Furthermore, in the same figures, the leftward direction may be referred to as "forward Y1" and the opposite direction as "backward Y2", and both of these directions may be collectively referred to as "front-back direction Y". In addition, in the same figures, the direction towards the viewer on the page may be referred to as "rightward X1" and the opposite direction as "leftward X2", and both of these directions may be collectively referred to as "left-right direction X".

[0027] In addition, the top view refers to a viewpoint from which the attachment 100 and holder 200 are viewed from above Z1 to below Z2, and the bottom view is the opposite viewpoint. Furthermore, the front view refers to a viewpoint from which the attachment 100 and holder 200 are viewed from forward Y1 to rear Y2, and the rear view is the opposite viewpoint. Moreover, the right side view refers to a viewpoint from which the attachment 100 and holder 200 are viewed from right X1 to left X2, and the left side view is the opposite viewpoint.

[0028] Based on the above definition of direction, Figure 1 corresponds to a right side view of the attachment 100, and Figure 2 corresponds to a right cross-sectional view showing the attachment 100 attached to the holder 200. Furthermore, Figure 3 is a perspective view of the attachment 100 seen from the front Y1 towards the right X1 and slightly above Z1, and Figure 4 is a transparency perspective view corresponding to Figure 3. In addition, Figure 5 is a bottom view of the attachment 100, and Figure 6 is a front view of the attachment 100.

[0029] The attachment 100 of this embodiment comprises a housing 1 (corresponding to an example of the "base portion" in this disclosure) which is generally substantially rectangular in shape, and a leg portion 2 having a plurality (two in this embodiment) of legs 21A, 21B provided on the housing 1. The housing 1 has an upper surface 1U (corresponding to an example of the "first plane" in this disclosure) and a lower surface 1L (corresponding to an example of the "second plane" in this disclosure) that face each other, and a front surface 1F, a rear surface 1B, and a side surface 1S connected thereto. Of these, the upper surface 1U and the lower surface 1L are planes perpendicular to the direction in which the leg portion 2, which will be described later, is projected (up and down direction Z). That is, both the upper surface 1U and the lower surface 1L are parallel to the front-rear direction Y and the left-right direction X.

[0030] Furthermore, the front surface 1F of the housing 1 is a plane that is substantially perpendicular to the upper surface 1U and the lower surface 1L, that is, it is substantially parallel to the direction of projection of the leg portion 2 (vertical direction Z), which will be described later. In addition, the side surface 1S and the rear surface 1B of the housing 1 have a slope that gradually widens from the top Z1 to the bottom Z2 (flaring at the base), and the housing 1 as a whole has a substantially trapezoidal shape when viewed from the front-rear direction Y (Figures 1, 6, etc.). Furthermore, the side surface 1S is formed symmetrically in the left-right direction X (left-right symmetry), and the periphery where the side surface 1S and the rear surface 1B connect to the lower surface 1L has a circular shape from the center in the front-rear direction Y towards the rear Y2 side (Figures 5, 6, etc.). In addition, the rear surface 1B has a shape in which the central part is slightly recessed forward Y1 (Figures 3, 4, etc.).

[0031] Furthermore, legs 21A and 21B are provided projecting downward Z2 from the lower surface 1L of the housing 1. The base end portion of these legs 21A and 21B that connects to the lower surface 1L of the housing 1 is a circumferential base end portion 22. In addition, the legs 21A and 21B are spaced apart from each other by a groove 24 from the base end portion 22 to the protruding ends 23A and 23B. Here, if the faces of the legs 21A and 21B that face each other are called the inner surface 21N, and the face opposite the inner surface 21N is called the outer surface 21G, then projections 25A and 25B (corresponding to an example of a "protrusion" in this disclosure) are provided on the outer surfaces 21G and 21G. More specifically, the projections 25A and 25B are formed to protrude outward in the front-rear direction Y at a point on the protruding end 23A and 23B side (in this embodiment, the protruding end portion including the protruding ends 23A and 23B) rather than at the midpoint (position) in the length of the legs 21A and 21B. Furthermore, the protrusions 25A and 25B are tapered towards the tips 23A and 23B.

[0032] Furthermore, the inner surfaces 21N, 21N of these legs 21A, 21B have an inclination such that the distance between them gradually increases from the lower surface 1L of the housing 1 toward their protruding ends 23A, 23B. For example, as shown in Figure 1, the inner surfaces 21N, 21N have an inclination such that the distance D2 (in this case a side view) closer to the protruding ends 23A, 23B is greater than the distance D1 (in this case a side view) closer to the housing 1 (D2 > D1). Moreover, as shown in Figures 3 to 5, both the inner surface 21N and outer surface 21G of the legs 21A, 21B have an arc shape that bulges outward (outward) in a plane or cross-section perpendicular to their protruding direction (vertical direction Z).

[0033] Furthermore, a projection 3 (corresponding to an example of the "locking structure" on the attachment side in this disclosure) having a length E3 shorter than the length E2 of the legs 21A and 21B is provided on the lower surface 1L of the housing 1 near the front Y1, projecting in the same direction as the legs 21A and 21B (downward towards Z2). More specifically, the length E3 of the projection 3 is less than half the length E2 of the legs 21A and 21B.

[0034] Here, Figure 8 is a schematic front view showing the cutting tool 1000 according to this embodiment. The cutting tool 1000 has a cutting edge portion 300, such as a cutting insert, detachably attached (replaceable) to the front Y1 end of a holder 200 to which an attachment 100 is attached. The holder 200 is, for example, a tool holder in which the shank and head are integrally formed, or, in the case of a tool holder having a configuration in which the head is replaceably attached to the shank, it corresponds to the head portion. As shown in Figure 2, which shows a cross-section of a part thereof, the holder 200 has a hole 5 drilled in its upper surface 200U into which the leg portion 2 of the attachment 100 is inserted. Furthermore, the hole 5 has a circular shape in a horizontal cross-section parallel to the upper surface 200U (circular hole), and an annular groove 5K (corresponding to an example of a "recess" in this disclosure) is provided in the middle of the inner wall 5N surface of the hole 5, into which the tips of the protrusions 25A and 25B provided on the legs 21A and 21B of the attachment 100 can engage. In addition, a recess 6 (corresponding to an example of a "locking structure" on the body side in this disclosure) is formed in front of the hole 5 Y1 on the upper surface 200U of the holder 200, into which the protrusion 3 of the attachment 100 is inserted so as to be embedded.

[0035] As shown in Figures 2 to 6, a through-hole 4 is formed inside the housing 1 of the attachment 100, penetrating the front surface 1F and the bottom surface 1L, and communicating with the groove 24 via the internal space of the base end 22. From these through-hole 4, the base end 22, and the groove 24, a flow path R100 through which the coolant flows is defined, as shown particularly in Figure 2. A curved bend 4C is provided in the middle of this through-hole 4. In addition, the hole 5 of the holder 200 is, for example, a through-hole, and functions as another flow path R200 through which the coolant flows. This hole 5 communicates with an arbitrary coolant supply path (not shown), and when the attachment 100 is attached to the holder 200, a connecting path is defined such that the flow paths R100 and R200 partially overlap. As a result, coolant from a coolant supply passage (not shown) is sent from the holder 200 to the attachment 100 side through the connecting passage and discharged from the opening on the front surface 1F toward the cutting edge of the cutting edge portion 300 which is mounted on the front Y1 side of the holder 200.

[0036] Furthermore, although the flow paths R100, R200 and the defined connecting passages are cylindrical as a whole, the cross-sectional contour shape of the portion of the flow path R100 between the front surface 1F and the bent portion 4C is, as shown in Figures 3, 4, and 6, for example, a so-called teardrop shape. Here, "teardrop shape" refers to a smooth, streamlined curved shape that resembles a teardrop, with a rounded top that gradually narrows in width towards the bottom and a pointed tip, evoking the shape of a water droplet or tear falling. In addition, although not shown in the figures, a sealing material such as an O-ring may be provided on the lower surface 1L of the housing 1 or on the base end 22 of the leg portion 2.

[0037] With the attachment 100, holder 200, and cutting tool 1000 configured as described above, first, projections 25A and 25B are provided on the outer surfaces 21G and 21G of the legs 21A and 21B of the leg portion 2. If the legs 21A and 21B are elastic, they will narrow their separation distance D2 and be inserted into the hole 5 of the holder 200. When the projections 25A and 25B reach the annular groove 5K of the hole 5, the deformation of the legs 21A and 21B will expand back to its original state, and the projections 25A and 25B will engage with the annular groove 5K of the hole 5. Therefore, the attachment 100 can be easily attached to the holder 200 in a way that prevents the attachment 100 from easily detaching from the holder 200. Thus, since there is no need to use screws when attaching the attachment 100 to the holder 200, the number of parts and manufacturing man-hours can be reduced, and the attachment 100, the holder 200, and the cutting tools that contain them can be miniaturized. As a result, it is possible to improve the economic efficiency and productivity when manufacturing the attachment 100 and the holder 200.

[0038] In other words, the attachment structure to the holder 200 utilizes the elasticity of the legs 21A and 21B of the attachment 100's leg portion 2, allowing for secure fastening without the use of screws or tools. This makes it easier to mount the attachment 100 to the holder 200, which was previously difficult, especially for small cutting tools used in micro-machining, thereby increasing its applicability and versatility to small cutting tools. Furthermore, the simple mounting of the attachment 100 to the holder 200 significantly improves work efficiency compared to conventional screw-fixed types. In addition, the optimized shape of the leg portion 2 and the ease of mounting to the hole portion 5 of the holder 200 enhance the stability of the attachment 100 when mounted to the holder 200. Moreover, since the shapes of the housing 1 and leg portion 2 can be designed arbitrarily, it can accommodate various applications and holder 200 shapes, and this high degree of design freedom contributes to the development of highly versatile cutting tools.

[0039] Furthermore, the protrusions 25A and 25B are located closer to the tips 23A and 23B than the midpoint (position) in the length E2 of the legs 21A and 21B, more specifically, in the portion including the tips 23A and 23B. Therefore, even if the length E2 of the legs 21A and 21B is shortened, it becomes easier to impart elasticity to them (it becomes easier to ensure elasticity), which is effective in miniaturizing the legs 2 and, consequently, the attachment 100.

[0040] Furthermore, a projection 3 having a length E3 shorter than the length E2 of the legs 21A and 21B is provided on the lower surface of the housing 1, near the front Y1, and protrudes in the same direction (downward Z2) as the legs 21A and 21B. More specifically, the length E3 of the projection 3 is less than half the length E2 of the legs 21A and 21B. Also, a recess 6 into which the projection 3 is inserted is drilled in the holder 200. Therefore, when attaching the attachment 100 to the holder 200, the projection 3 of the attachment 100 can be easily fitted into the recess 6 of the holder 200. This reduces the effort required and ensures that the attachment 100 is reliably positioned on the holder 200, and also prevents the attachment 100 from rotating along the upper surface 200U of the holder 200.

[0041] Furthermore, both legs 21A and 21B have inner surfaces 21N and outer surfaces 21G that bulge outward in a plane or cross-section perpendicular to their protruding direction (vertical direction Z). Therefore, when legs 21A and 21B are inserted into the circular hole 5 drilled in the holder 200, the outer surfaces 21G and 21G of legs 21A and 21B are positioned along the inner wall 5N surface of the hole 5, thereby narrowing the gap (clearance) between legs 21A and 21B and the hole 5, or allowing them to come into contact. This further enhances the stability when the attachment 100 is mounted on the holder 200.

[0042] Furthermore, since the upper surface 1U of the housing 1 is a flat surface perpendicular to the direction of the protrusion of the leg portion 2 (vertical direction Z), it is useful when miniaturizing the attachment 100 using a powder bed method of manufacturing with a metal 3D printer. When using such additive manufacturing, it is desirable to perform the additive manufacturing from the housing 1 toward the leg portion 2 from the viewpoint of maintaining the shape during manufacturing and ease of manufacturing. In other words, in such a procedure, as shown in Figure 7, the additive manufacturing can be performed in a direction that is the inversion of the state in Figure 1 (from the upper Z1 to the lower Z2 in Figure 1). Therefore, if the upper surface 1U of the housing 1 is used as the reference surface (starting surface for manufacturing) for the formation of the leg portion 2, then by forming the leg portion 2 in a direction perpendicular to it, it is possible to suppress the deformation of the protrusions 25A and 25B that are manufactured in the final stage due to the weight of their metal material, and in particular, the dimensional accuracy of the legs 21A and 21B can be improved.

[0043] Furthermore, the lower surface 1L of the housing 1 is a plane perpendicular to the direction in which the legs 2 protrude (vertical direction Z), but is not limited to this, and may have any angle with a plane parallel to the direction in which the legs 2 protrude (vertical direction Z). An example of the angle (slope) of the lower surface 1L in this case is shown in Figure 1 as a dashed line (straight line). In this way, the part of the housing 1, especially the lower surface 1L, can be made into any shape suitable for securing the flow path R100 for the coolant provided inside the housing 1.

[0044] Further, the inner surfaces 21N, 21N of the legs 21A, 21B are formed such that the distance D2 closer to the protruding ends 23A, 23B is larger than the distance D1 closer to the housing 1 (D2 > D1). Thus, it becomes easier to make the thickness T1 (in side view) of the portion on the base end 22 side in the legs 21A, 21B larger than the thickness T2 (in side view) of the portion on the protruding ends 23A, 23B side, so that the strength (flexural resistance) of the elastic legs 21A, 21B can be increased. However, the configuration is not limited to such as D2 > D1, and conversely, it can also be configured such that D2 < D1, that is, the distance between the inner surfaces 21N, 21N of the legs 21A, 21B gradually decreases from the housing 1 toward the protruding ends 23A, 23B. Thereby, the flexibility of the legs 21A, 21B can be adjusted or made to correspond to a specific application.

[0045] As described above, the present embodiment has been explained, but it is for facilitating the understanding of the present disclosure and not for limiting the interpretation of the present disclosure. That is, the present disclosure is not necessarily limited to the specific configurations described above, and those obtained by appropriately making design changes by those skilled in the art to those specific configurations are also included in the scope of the present disclosure as long as they have the features of the present disclosure. Further, each element, arrangement, material, condition, shape, dimensional size, scale, etc. included in the above-described specific configurations are not limited to those exemplified unless otherwise specifically stated, and can be changed as appropriate. Furthermore, each element included in the above-described specific configurations can be used by appropriately changing the combination as long as no technical contradiction occurs.

[0046] That is, for example, the upper surface 1U, the lower surface 1L, and the front surface 1F may have surfaces other than a plane, or may not have a planar portion. On the other hand, the side surfaces 1S and the rear surface 1B may be asymmetrical left and right and may have a plane. Further, the overall shape of the housing 1 is not limited to a substantially rectangular parallelepiped, and can be any shape. For example, as shown in FIG. 6, the housing 1 of the above embodiment has a substantially trapezoidal shape when viewed from the front-rear direction Y. Thereby, while securing a space for providing a sealing material (O-ring or the like) on the lower surface 1L side, the volume of the upper surface 1U can be reduced (hollowed out), contributing to miniaturization and reduction of material costs. Further, the attachment 100 and the holder 200 may not have the flow paths R100 and R200. That is, the attachment 100 and the holder 200 are not limited to the use for supplying a coolant.

[0047] Further, the legs 2 are not limited to the two columnar legs 21A and 21B, and may be composed of three or more polygonal legs. Further, the hole 5 of the holder 200 may not be a circular hole, but may be an arbitrary polygonal hole. In this case, the legs 21A and 21B do not have to be formed in an arc shape that bulges outward. Furthermore, only one of the protrusions 25A and 25B may be provided, or a plurality of protrusions may be provided on each of the legs 21A and 21B.

[0048] Furthermore, the portion where the annular groove 5K of the hole 5 is provided is not limited to a rectangle as shown in FIG. 2, and any shape may be adopted as long as it has a structure or shape that allows the protrusions 25A and 25B provided on the legs 2 of the attachment 100 to engage or fit. For example, instead of the annular groove 5K, a non-annular groove (recess) may be provided. In this case, grooves or recesses may be provided only at the portions corresponding to the protrusions 25A and 2SB. Alternatively, instead of the annular groove 5K, an appropriate step, for example, a step shape in which the cross-sectional area or the width diameter perpendicular to the vertical direction Z of the hole 5 expands as it goes in the depth direction (downward Z2), or a cross-sectional reverse L-shaped portion may be provided. Further, it may be a portion having a convex shape that gently protrudes once toward the inside of the hole 5 and then expands in diameter as it goes in the depth direction. Also, for one hole 5, only one portion (recess or step) where either the protrusion 25A or the protrusion 25B engages or fits may be formed.

[0049] In addition, the projection 3 and recess 6 of the housing 1 are optional, or multiple projections may be provided. Also, although Figure 1 shows the distances D1 and D2 between the inner surfaces 21N and 21N of the legs 21A and 21B in a side view, these distances D1 and D2 may also be defined as the distance between the inner wall surfaces in a cross-sectional view perpendicular to the direction of projection. Similarly, although Figure 1 shows the thicknesses T1 and T2 of the legs 21A and 21B in a side view, these thicknesses T1 and T2 may also be defined as the thickness in a cross-sectional view perpendicular to the direction of projection. Furthermore, the hole 5 may be formed as a blind hole instead of a through hole, and configured to intersect with a flow path provided inside the holder 200 from the rear Y2 end to the front Y1 end of the shank. In addition, the body of the cutting tool 1000 may be a component other than the holder 200.

[0050] 1...Housing (base part), 1B...Rear surface, 1F...Front surface, 1L...Bottom surface (second plane), 1S...Side surface, 1U...Top surface (first plane), 2...Leg part, 3...Protrusion (locking structure on the attachment side), 4...Through hole, 4C...Bent part, 5...Hole part, 5K...Annular groove (recess or step), 5N...Inner wall, 6...Recess (locking structure on the body side), 21A, 21B...Leg, 21G...Outer surface, 21N...Inner surface, 22...Base end part, 23A, 23 B...tip, 24...groove, 25A, 25B...projection (protrusion), 100...attachment, 200...holder (body), 200U...top surface, 300...cutting edge, 1000...cutting tool, D1, D2...distance, E2, E3...length, R100, R200...flow path, T1, T2...thickness, X...left-right direction, X1...right, X2...left, Y...front-back direction, Y1...forward, Y2...rear, Z...up-down direction, Z1...upward, Z2...downward

Claims

1. An attachment for a cutting tool, comprising: a base portion; and a leg portion having a plurality of legs protruding from the base portion and spaced apart from each other, wherein when the faces of the plurality of legs facing each other are considered inner surfaces and the faces opposite the inner surfaces are considered outer surfaces, a protrusion is provided on at least one of the outer surfaces of the plurality of legs.

2. The attachment according to claim 1, wherein the protrusion is provided on the tip side of at least one of the lengths of the plurality of legs, beyond the midpoint.

3. The attachment according to claim 2, wherein the protrusion is provided on the tip of at least one of the plurality of legs.

4. The attachment according to claim 1, further comprising a locking structure for locking the attachment to the cutting tool.

5. The attachment according to claim 4, wherein the locking structure protrudes from the base portion in the same direction as the legs and has a length shorter than the length of at least one of the plurality of legs.

6. The attachment according to claim 1, wherein at least one of the inner surfaces and outer surfaces of at least one of the plurality of legs has an outwardly bulging arc shape in a plane or cross section perpendicular to the direction in which the leg protrudes.

7. The attachment according to claim 1, wherein the base portion has a first plane in at least a portion of the region opposite to the side on which the leg portion is provided.

8. The attachment according to claim 7, wherein the first plane is perpendicular to the direction in which the leg portion protrudes.

9. The attachment according to claim 1, wherein the base portion has a second plane from which the leg portion is projected, and the second plane is perpendicular to the direction in which the leg portion is projected, or forms an arbitrary angle with a plane perpendicular to the direction in which the leg portion is projected.

10. The attachment according to claim 1, wherein the distance between the inner surfaces of the plurality of legs gradually increases from the base portion toward the tips of the plurality of legs.

11. The attachment according to claim 1, wherein the distance between the inner surfaces of the plurality of legs gradually decreases from the base portion toward the tips of the plurality of legs.

12. A body to which an attachment is attached, wherein the attachment comprises: a base portion and a leg portion having a plurality of legs protruding from the base portion and spaced apart from each other, wherein when the faces of the plurality of legs facing each other are considered inner surfaces and the faces opposite the inner surfaces are considered outer surfaces, a protrusion is provided on at least one of the outer surfaces of the plurality of legs, and the body has a hole into which the leg portion of the attachment is inserted, and the inner wall surface of the hole is provided with a recess or step into which the protrusion provided on the leg portion of the attachment engages or fits.

13. The body according to claim 12, wherein only one recess or step is formed in each of the holes.

14. The body according to claim 12, further comprising a locking structure for locking the attachment.

15. A cutting tool having a cutting edge and an attachment attached to a body, wherein the attachment comprises: a base portion and a leg portion having a plurality of legs protruding from the base portion and spaced apart from each other, wherein when the faces of the plurality of legs facing each other are considered inner surfaces and the faces opposite the inner surfaces are considered outer surfaces, a protrusion is provided on at least one of the outer surfaces of the plurality of legs, and the body comprises: a hole portion into which the leg portion of the attachment is inserted, and a recess or step is provided on the inner wall surface of the hole portion into which the protrusion provided on the leg portion of the attachment engages or fits.

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