Attachment and cutting tool

Abstract

An attachment (100) according to the present disclosure is used as a constituent of a cutting tool (1000), and has a second surface (1L) and a first surface (1U) including a flat surface, and a third surface (1F) connecting the first surface (1U) and the second surface (1L), the second surface (1L) being provided with an attachment part (2) that engages or fits with another part included in the cutting tool (1000), wherein a flow path (R100) through which a fluid flows is formed, and the flow path (R100) has an outflow port (C3) that opens to the third surface (1F) and an inflow port (C1) that communicates with the outflow port (C3). The contour of the outflow port (C3) is at least partially convex toward the second surface (1L), and has at least two linear portions.

Description

Attachment and Cutting Tool

[0001] The present disclosure relates to an attachment and a cutting tool including the same.

[0002] As an attachment attached to a cutting tool, for example, in Patent Documents 1 and 2, a nozzle or a discharge member attached to a holder for supplying a coolant (fluid) to a cutting insert (cutting edge portion) fixed to the holder is described.

[0003] Japanese Patent No. 7312243 Japanese Patent No. 7559650

[0004] In the conventional nozzles and the like, shapes such as circular and elliptical shapes have been proposed as the opening shape of the outlet from which the coolant is discharged and the cross-sectional shape of the flow path near the outlet. On the other hand, in order to manufacture such attachments such as nozzles at a low cost, for example, powder bed type additive manufacturing using a metal 3D printer is widely used. However, when trying to manufacture nozzles and the like having the conventional circular or elliptical opening shapes and cross-sectional shapes by such additive manufacturing, due to the characteristics of additive manufacturing, the part material may not be able to withstand its own weight and may deform so as to sag in the direction opposite to the stacking direction (vertically downward). In such a case, it may be impossible to secure the designed opening shape and outlet area, and there is a risk that a sufficient discharge amount of coolant cannot be supplied to the cutting edge portion, or the yield in manufacturing nozzles and the like may decrease.

[0005] Therefore, the present disclosure has been made in view of the above circumstances, and an object thereof is to provide an attachment for a cutting tool that can be miniaturized by additive manufacturing and can secure a designed opening shape and outlet area in a fluid supply flow path, and a cutting tool including the attachment.

[0006] [1] An example of an attachment according to the present disclosure is an attachment for a cutting tool, having a first surface including a plane, a second surface opposite to the first surface, and a third surface connecting the first and second surfaces, with a mounting portion provided on the second surface that can engage or fit with other parts constituting the cutting tool, and a flow path formed therein having an outlet through which fluid flows and which opens to the third surface, and an inlet communicating with the outlet. The contour of the outlet is convex toward the second surface in at least a part thereof and has at least two straight portions.

[0007] Furthermore, in this disclosure, "attachment" refers primarily to auxiliary or functional members that are attached to basic components, basic members, devices, etc. (other parts that constitute a cutting tool) such as holders for "cutting tools" to provide additional functions or uses, and is a concept that includes "parts" in general. Also, "linear portion" is not limited to a strictly "straight line," and may be a line such as a "gentler arc" than the curvature of a perfect circle when the overall outline of the outlet is a perfect circle, or a line that includes a "chord" connecting two points in the middle of the arc, or a line that is a mixture of curves and straight lines.

[0008] In such a configuration, for example, an appropriate fluid (such as a coolant or air) is supplied to the cutting edge of the cutting tool through a channel formed in the attachment. As for the manufacturing method of such an attachment, as mentioned above, additive manufacturing using a powder bed method with a metal 3D printer is preferably used in order to miniaturize the attachment. In this case, from the viewpoint of maintaining the shape during manufacturing and ease of manufacturing, for example, it is desirable to perform additive manufacturing from the base portion of the attachment toward the mounting portion that protrudes from it, that is, to use the plane on the first surface of the attachment as the formation reference surface (formation starting surface), and to sequentially form the base portion and the mounting portion in a direction perpendicular to it.

[0009] In this case, the attachment of the present disclosure is formed such that at least a portion of the outlet contour is convex from the first surface to the second surface and has at least two linear portions. According to the inventors' findings, having such two linear portions improves resistance to sagging and deformation due to the weight of the component material compared to cases where the outlet contour is a conventional circular or elliptical shape. Therefore, even when the attachment is manufactured by additive manufacturing for miniaturization, it is possible to secure the desired contour shape and outlet area as designed, especially at the outlet of the fluid flow path.

[0010] [2] On the other hand, in the above configuration, the region of the outlet contour on the first surface side is located vertically below the second surface side in additive manufacturing where the plane on the first surface is the formation reference plane. Therefore, in terms of manufacturing characteristics, no particular constraints are imposed on its shape, and the region on the first surface side may be configured such that at least a part different from the part that is convex toward the second surface is, for example, arc-shaped, or has at least two straight parts (U-shaped or polygonal parts). This makes it possible to adjust the flow path to a shape that suits the purpose when additive manufacturing is used for the manufacture of attachments, thereby increasing the degree of design freedom.

[0011] More specifically, the outline of the outlet can preferably have an interior angle of approximately 60°, more preferably approximately 45°, and even more preferably approximately 45°, between the linear portion in the convex portion toward the second surface and the vertical direction (direction of gravity). In this disclosure, "approximately" means within ±10% of the center value (the same applies hereinafter). Also, as mentioned above, the "linear portion" is not limited to a strictly "straight line" but also includes things like "arc-shaped" shapes, so in that case, the above "interior angle" may be, for example, the interior angle that the virtual straight line obtained by connecting the start and end points of the linear portion makes with the vertical direction. In this way, deformation of the shape during additive manufacturing can be more effectively suppressed, and even when the attachment is further miniaturized, there is an advantage in that it is easier to secure a sufficient outlet area of ​​the outlet.

[0012] [6 and 7] In the above configuration, the flow path may have an inlet passage including an inlet, an outlet passage including an outlet, and an intermediate passage connecting the inlet passage and the outlet passage, and which is curved, for example, in an arc shape. With such an intermediate passage, even if the inlet passage and the outlet passage extend in different directions, they are connected at a gentle angle, and compared to the case where they are connected so as to intersect at a steep angle, the fluid can be discharged smoothly without obstructing the flow of fluid in the flow path.

[0013] [8] In the above configuration, if the maximum cross-sectional area of ​​the outflow passage is smaller than the minimum cross-sectional area of ​​the inflow passage in a cross-sectional view in the direction of extension of the flow path, the fluid that flows into the flow path will be pressurized as it moves toward the outlet, thereby increasing the discharge force and discharge velocity of the fluid discharged from the outflow passage.

[0014] [9] In the above configuration, the direction of extension of the inlet passage may be at any angle with respect to the plane of the first surface. For example, that portion may be configured to be substantially perpendicular to the plane of the first surface (for example, so that the inlet opens to the mounting portion). This makes it easier to adjust the shape of the flow path to any shape other than a straight pipe shape to suit the purpose.

[0015]

[10] Furthermore, in a cross section that is substantially perpendicular to the plane of the first surface and the third surface and substantially bisecting the intermediate passage, if the radius of curvature on the inside of the intermediate passage is smaller than the radius of curvature on the outside of the intermediate passage, the pressure loss when the fluid flows through the passage can be reduced, and the flow velocity and flow rate of the passage can be suitably maintained.

[0016]

[11] Another example of a cutting tool according to the present disclosure is a cutting tool equipped with an attachment according to the present disclosure. That is, the cutting tool according to the present disclosure has an attachment having a first surface including a plane, a second surface opposite to the first surface, and a third surface connecting the first surface and the second surface, with a mounting portion provided on the second surface that can engage or fit with other parts constituting the cutting tool, and a flow path is formed having an outlet through which a fluid flows and which opens to the third surface, and an inlet communicating with the outlet, and at least a part of the contour of the outlet is convex toward the second surface and has at least two straight portions.

[0017] According to this disclosure, it is possible to realize a cutting tool attachment that can be miniaturized, secure the desired opening shape and outlet area, and supply a sufficient amount of fluid to the cutting edge, as well as a cutting tool equipped with this attachment. As a result, it is possible to improve the precision, cost-effectiveness, and productivity when manufacturing the attachment and the cutting tool.

[0018] 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. This is a perspective view of the attachment 100 from the front Y1, slightly above and to the right X1 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 6 inverted vertically. This is a schematic front view showing the cutting tool 1000 according to this embodiment. (A) and (B) are schematic front views showing the cross section of the outflow passage R130 and various other shapes of the contour at the outlet C3. (A) to (D) are schematic front views showing the cross section of the outflow passage R130 and various other shapes of the contour at the outlet C3.

[0019] 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.

[0020] 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, for example, a holder 200 (corresponding to an example of "other parts" in this disclosure) of a cutting tool.

[0021] 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".

[0022] 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.

[0023] 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.

[0024] The attachment 100 of this embodiment comprises a housing 1 (base portion) which is generally substantially rectangular in shape, and a leg portion 2 having two legs 21A and 21B provided on the housing 1. The housing 1 has an upper surface 1U (corresponding to an example of the "first surface" in this disclosure) and a lower surface 1L (corresponding to an example of the "second surface" in this disclosure) that face each other, and a front surface 1F (corresponding to an example of the "third surface" in this disclosure), 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 protrudes (vertical 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.

[0025] 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, substantially parallel to the direction in which the legs 2 protrude (vertical direction Z). 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 and the rear surface 1B are 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.).

[0026] 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 we consider the faces of the legs 21A and 21B that face each other as the inner surface 21N, and the face opposite the inner surface 21N as the outer surface 21G, then projections 25A and 25B are provided at the protruding ends, including the protruding ends 23A and 23B, on the outer surfaces 21G and 21G. These projections 25A and 25B are tapered toward the protruding ends 23A and 23B.

[0027] Furthermore, the inner surfaces 21N, 21N of the 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. In addition, 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). Moreover, a projection 3, shorter in length than the length of the legs 21A, 21B, is provided on the lower surface 1L of the housing 1, closer to the front Y1, projecting in the same direction as the legs 21A, 21B (downward Z2).

[0028] 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 mounted (replaceable) at 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 the cross-section of a part of the holder 200 in Figure 2, a hole portion 5 is drilled in the upper surface 200U into which the leg portion 2 of the attachment 100 is inserted. Thus, an example of the "mounting portion" in this disclosure is formed from the leg portion 2 and the hole portion 5. Furthermore, an annular groove 5K is provided in the middle of the inner wall surface 5N of the hole portion 5, into which the tips of the protrusions 25A and 25B provided on the legs 21A and 21B of the attachment 100 can engage. Furthermore, a recess 6 is formed in front of the hole 5 on the upper surface 200U of the holder 200, Y1, into which the projection 3 of the attachment 100 is inserted and embedded.

[0029] 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 a 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 is defined through which a coolant (corresponding to an example of "fluid" in this disclosure) flows, as shown particularly in Figure 2. In this flow path R100, the opening between the protruding ends 23A and 23B of the leg portion 2 serves as the coolant inlet C1, the opening of the through-hole 4 on the front surface 1F of the housing 1 serves as the coolant outlet C3, and a curved bent portion 4C is provided in the middle of the through-hole 4.

[0030] In other words, the flow path R100 on the attachment 100 side consists of an inlet passage R110, an intermediate passage R120, and an outlet passage R130 through which the coolant flows. Of these, the inlet passage R110 is the part that communicates with the inlet C1 and extends along the direction in which the leg portion 2 protrudes. The outlet passage R130 is the part that communicates with the outlet C3 and extends along the upper surface 1U and lower surface 1L of the housing 1. Furthermore, the intermediate passage R120 is the part that consists of a bent portion 4C of a through hole 4 that is bent in an arc shape to connect the inlet passage R110 and the outlet passage R130. In addition, as shown in Figure 2, the intermediate passage R120 is substantially perpendicular to the upper surface 1U and the lower surface 1L, and in the cross section that substantially bisects the intermediate passage R120 (i.e., the cross section shown in Figure 2), the radius of curvature R41 of the inner portion 41 of the bent portion 4C is smaller than the radius of curvature R42 of the outer portion 42 of the bent portion 4C (R41 < R42). Furthermore, the inflow passage R110 is configured such that its extending direction is substantially perpendicular to the upper surface 1U and the lower surface 1L of the housing 1, or that it forms an arbitrary angle with the upper surface 1U and the lower surface 1L of the housing 1.

[0031] Furthermore, the hole 5 in the holder 200 is, for example, a through hole and functions as another flow path R200 through which the coolant flows. This hole 5 is in communication with an arbitrary coolant supply path (not shown), and when the attachment 100 is attached to the holder 200, a connecting path is defined in which the flow paths R100 and R200 partially overlap. As a result, the coolant from the coolant supply path (not shown) is sent from the holder 200 to the attachment 100 through this connecting path. The coolant is then discharged from the outflow path R130, which opens on the front surface 1F, toward the cutting edge portion 300, which is mounted on the front Y1 side of the holder 200.

[0032] Furthermore, while the flow paths R100, R200 and the defined integrated flow path are cylindrical as a whole, the cross-section of the outflow passage R130 (a cross-section perpendicular to the central axis J100 of the flow path R100; the same applies hereafter) and the contour shape at the outlet C3 are, 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 towards the bottom and a pointed tip, evoking the shape of a water droplet or tear falling. Note that "central axis J100 of the flow path R100" refers to, for example, the center of a virtual circular contour including the arc when at least a part of each section of the flow path R100 (inflow passage R110, intermediate passage R120, and outflow passage R130) has a circular arc cross-section (see Figures 9 and 10 described later).

[0033] Thus, the cross-section of the outflow passage R130 and the contour of the outlet C3 are such that at least a portion of them (the portion Z2 below the central axis J100 of the flow path R100) is convex toward the lower surface 1L of the housing 1, and has at least two straight sections. On the other hand, the cross-section of the inflow passage R110 and the contour of the inlet C1 are not particularly limited and can be circular or elliptical, for example, as shown in Figure 5. In addition, the cross-section at the boundary between the inflow passage R110 and the intermediate passage R120 is perfectly circular, and as it approaches the boundary between the outflow passage R130 and the intermediate passage R120, it gradually becomes teardrop-shaped.

[0034] Here, Figures 9(A) and (B) are schematic front views showing various shapes of the cross section of the outflow channel R130 and the contour of the outlet C3. Of these, Figure 9(A) corresponds to the teardrop shape described above as shown in Figures 3, 4, and 6, and shows the case where the interior angle θ made by the two linear sections with respect to the vertical direction (up and down direction Z) is approximately 45°. Figure 9(B) shows the case where the interior angle θ is approximately 60°. In the contour shapes shown in Figures 9(A) and (B), the two linear sections are formed downward Z2 from a position where the angle α with respect to the left-right direction X is approximately 45°. As a result, even if the material deforms due to the influence of gravity during additive manufacturing, an area of ​​the outlet C3 that is close to a perfect circle can be obtained.

[0035] Furthermore, Figures 10(A) to (D) are schematic front views showing various other shapes of the cross-section of the outflow channel R130 and the contour at the outlet C3. The contour shape shown in Figure 10(A) is an example of a shape similar to a teardrop, and the contour shape shown in Figure 10(B) is an example in the shape shown in Figure 10(A), in which the region on the lower surface 1L (downward Z2) side of the central axis J100 is composed of three linear portions. In addition, the contour shapes shown in Figures 10(C) and 10(D) are modified examples in which the shape shown in Figure 10(A) differs in the shape of the region on the upper surface 1U (upward Z1) side of the central axis J100. More specifically, Figure 10(C) shows an example in which the region on the upper surface 1U (upward Z1) side of the central axis J100 is composed of three linear sections, and the upper side is slightly convex toward the upper surface 1U (upward Z1), which can be called a home plate shape (the upper side is U-shaped). In addition, Figure 10(D) shows an example of a polygonal shape in the home plate shape as in Figure 10(C), in which the region on the upper surface 1U (upward Z1) side of the central axis J100 is further composed of multiple (six) linear sections. In any of the contour shapes shown in Figures 10(A) to (D), as an example, the interior angle θ is approximately 45° or less.

[0036] Furthermore, in this embodiment, in a cross-sectional view of the flow path R200 in the extending direction, the maximum cross-sectional area S130 of the outflow passage R130 (equivalent to the area of ​​the outlet C3 here; see Figure 5) is formed to be smaller than the minimum cross-sectional area S110 of the inflow passage R110 (equivalent to the area of ​​the inlet C1 here; see Figure 6) (S130 < S110).

[0037] In the attachment 100 and cutting tool 1000 configured as described above, as mentioned earlier, additive manufacturing using a powder bed method with a metal 3D printer is preferable in order to miniaturize the attachment 100. When using such additive manufacturing, a procedure in which layers are formed from the housing 1 toward the leg portion 2 is desirable 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, layers can be stacked in a direction that is the inverted of the state in Figure 6 (from the upper Z1 to the lower Z2 in Figures 1 and 6).

[0038] In this case, the attachment 100 is configured such that at least a portion of the cross-section of the outflow passage R130 and the contour of the outlet C3 are convex toward the lower surface 1L of the housing 1 and have at least two straight portions. Therefore, due to such shape factors, resistance to sagging and deformation due to the weight of the component material can be increased compared to cases where the cross-section of the outflow passage R130 and the contour of the outlet C3 are circular or elliptical as in the conventional method. As a result, even when the attachment 100 is manufactured by additive manufacturing for miniaturization, it is possible to secure the desired contour shape and outlet area as designed, particularly in the cross-section of the outflow passage R130 and the outlet C3 of the flow path R100. Consequently, when the cutting tool 1000 is constructed, a sufficient amount of coolant can be supplied to the cutting edge portion 300, and a decrease in yield when manufacturing the attachment 100 can be prevented, thereby improving economy and productivity.

[0039] Furthermore, the cross-section at the boundary between the inlet passage R110 and the intermediate passage R120 is perfectly circular, and it is formed to gradually become teardrop-shaped towards the boundary between the outlet passage R130 and the intermediate passage R120. Therefore, even in the intermediate passage R120, the effect of self-weight during additive manufacturing is reduced, and deformation can be prevented.

[0040] Furthermore, if the internal angle θ formed by the two linear portions in the region on the lower surface 1L side of the housing 1 with respect to the vertical direction (direction of gravity) in the cross-section of the outflow passage R130 and the contour of the outlet C3 is preferably less than approximately 60°, it becomes easier to secure the area required for the outlet C3. Moreover, if this internal angle θ is more preferably less than approximately 45°, it is useful from the viewpoint of further miniaturization of the attachment 100. That is, in this case, the shape changes of the outflow passage R130 and the outlet C3 in additive manufacturing can be suppressed more effectively against gravity, so even if further miniaturization of the attachment 100 is desired, sufficient cross-sectional area of ​​the outflow passage R130 and outlet area of ​​the outlet C3 can be secured. And if this internal angle θ is even more preferably approximately 45°, the housing 1 of the attachment 100 does not become too large in the vertical direction Z, while considering the deformation of the outlet C3, which is extremely effective from the viewpoint of miniaturization of the attachment 100.

[0041] On the other hand, of the contour of the outlet C3, the region on the upper surface 1U side of the central axis J100 of the flow path R100 is located vertically below the lower surface 1L in additive manufacturing using the upper surface 1U of the attachment 100 as the formation reference plane, as described above. Therefore, in terms of manufacturing characteristics, no particular constraints are imposed on its shape. For example, the region on the upper surface 1U side can take on various shapes, such as those shown in Figure 6, Figures 9(A) and (B), and Figures 10(A) to 10(D). This makes it possible to adjust the flow path R100 to a shape that suits the purpose when using additive manufacturing to manufacture the attachment 100, thereby increasing the degree of design freedom.

[0042] Further, the flow path R100 is defined by an inflow path R110, an intermediate path R120, and an outflow path R130. Among them, the intermediate path R120 is bent in an arc shape so as to connect the inflow path R110 and the outflow path R130 (see FIG. 2). Therefore, even if the inflow path R110 and the outflow path R130 extend in different directions (for example, are orthogonal), the two are connected at a gentle angle by the intermediate path R120. Accordingly, the circulation of the coolant in the flow path R100 is not hindered, and the coolant can be smoothly sent out through the flow path R100, rather than being connected so that the inflow path R110 and the outflow path R130 intersect at a sharp angle. At this time, the intermediate path R120 is substantially orthogonal to the upper surface 1U and the lower surface 1L, and in a cross section that substantially bisects the intermediate path R120 (that is, the cross section shown in FIG. 2), the radius of curvature R41 of the inner part 41 is smaller than the radius of curvature R42 of the outer part 42. Thereby, the pressure loss when the coolant flows through the flow path R100 is reduced, so that the flow velocity and flow rate of the coolant in the flow path R100 can be suitably maintained.

[0043] Further, in a cross-sectional view in the extending direction of the flow path R200, the maximum cross-sectional area S130 of the outflow path R130 is made smaller than the minimum cross-sectional area S110 of the inflow path R110. Therefore, the pressure of the coolant flowing into the flow path R100 is increased as it goes toward the outlet C3. As a result, the discharge force and discharge speed of the coolant discharged from the outlet C3 through the flow path R100 can also be increased, so that the supply of the coolant to the cutting edge portion 300 can be carried out more reliably and quickly.

[0044] Further, the inflow path R110 extends along the protruding direction (vertical direction Z) of the leg portion 2, and its extending direction is substantially perpendicular to the upper surface 1U and the lower surface 1L of the housing 1, or is configured to form an arbitrary angle. Therefore, when forming the inflow path R110 in the region of the leg portion 2 protruding from the lower surface 1L, there is an advantage that it becomes easier to further adjust the path and thus the overall shape of the flow path R100 according to the purpose.

[0045] The embodiments described above are intended to facilitate understanding of this disclosure and are not intended to limit its interpretation. In other words, this disclosure is not necessarily limited to the specific configurations described above, and any modifications made to those specific configurations by those skilled in the art are also included within the scope of this disclosure, as long as they retain the features of this disclosure. Furthermore, the elements, arrangements, materials, conditions, shapes, dimensions, scales, etc., of the aforementioned specific configurations are not limited to those exemplified unless otherwise specified, and can be modified as appropriate. Moreover, the elements of the aforementioned specific configurations can be used in combination in any way that does not create a technical inconsistency.

[0046] That is, for example, the shape of the through-hole 4 and thus the flow path R100 is not limited to the shape shown in the figure, and may be a shape that penetrates from the rear surface 1B to the front surface 1F in a straight or curved tubular shape, and the bent portion 4C does not have to be bent at a right angle but may be curved in an appropriate shape. Also, the top surface 1U, the bottom surface 1L, and the front surface 1F may have surfaces other than flat surfaces, or the bottom surface 1L and the front surface 1F may not have flat surfaces. On the other hand, the side surface 1S and the rear surface 1B may be asymmetrical and may have flat surfaces. Furthermore, the overall shape of the housing 1 is not limited to a roughly rectangular parallelepiped, but can be any shape. For example, as shown in Figure 6, the housing 1 of the above embodiment has a roughly trapezoidal shape when viewed from the front-to-back direction Y. This makes it possible to reduce the volume of the top surface 1U (weight reduction) while securing space for a sealing material (O-ring, etc.) on the bottom surface 1L side, thereby contributing to miniaturization and reduction of material costs.

[0047] Further, the leg portion 2 is not limited to the two columnar legs 21A and 21B, and may be composed of three or more polygonal legs. The leg portion 2 does not have to be separated by the groove 24 like the legs 21A and 21B, and may be, for example, cylindrical. Further, the "attachment portion" is not limited to the combination of the leg portion 2 and the hole portion 5. For example, a protruding portion like the leg portion 2 may be formed on the holder 200, and a concave portion like the hole portion 5 may be formed on the housing 1, and a structure in which the two are engaged or fitted may be adopted. The hole portion 5 of the holder 200 does not have to be a circular hole, and may be an arbitrary polygonal hole. In this case, the legs 21A and 21B do not have to be formed in an outwardly bulging arc shape. 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. Also, the inner angle θ shown in FIGS. 9 and 10 may be symmetric or asymmetric about the left and right. From the viewpoints of manufacturing and resistance to its own weight, symmetry about the left and right may be more preferable depending on the angle.

[0048] Furthermore, the portion where the annular groove 5K of the hole portion 5 is provided is not limited to a rectangle as shown in FIG. 2, and any shape can be adopted as long as it has a structure and shape in which the protrusions 25A and 25B provided on the leg portion 2 of the attachment 100 can be engaged or fitted. 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 25B. Alternatively, instead of the annular groove 5K, a portion having an appropriate stepped shape or a portion having an inverted L-shaped cross section may be provided. In addition, the protrusion 3 of the housing 1 and the recess 6 of the housing do not have to be provided, or a plurality of them may be provided. Also, the hole portion 5 can be formed as a blind hole instead of a through hole, and configured to intersect a flow path provided inside thereof from the rear end Y2 to the front end Y1 of the shank of the holder 200. Further, the body of the cutting tool 1000 may be a component other than the holder 200. Incidentally, although not shown, a sealing material such as an O-ring may be provided on the lower surface 1L of the housing ......

[0049] 1... Housing, 1B... Rear surface, 1F... Front surface (third surface), 1L... Bottom surface (second surface), 1S... Side surface, 1U... Top surface (first surface), 2... Leg (attachment portion), 3... Projection, 4... Through hole, 4C... Bent portion, 5... Hole portion (attachment portion), 5K... Annular groove, 5N... Inner wall, 6... Recessed portion, 21A, 21B... Legs, 21G... Outer surface, 21N... Inner surface, 22... Base end portion, 23A, 23B... Tip ends, 24... Groove, 25A, 25B... Projections, 41... Inner side portion, 42... Outer side portion, 100... Attachment, 200... Holder (other component), 200U... Top surface, 300... Cutting edge portion, 1000... Cutting tool, C1... Inlet, C3... Outlet, J100... Central axis, R100... Flow path (the "flow path" in the present disclosure), R200... Flow path, R110... Inflow path, R120... Intermediate path, R130... Outflow path, S110, S130... Maximum cross-sectional area, X... Left-right direction, X1... Right side, X2... Left side, Y... Front-back direction, Y1... Front side, Y2... Rear side, Z... Up-down direction, Z1... Upper side, Z2... Lower side

Claims

1. An attachment for a cutting tool, having a first surface including a flat surface, a second surface opposite to the first surface, and a third surface connecting the first surface and the second surface, wherein a mounting portion capable of engaging or fitting with other parts constituting the cutting tool is provided on the second surface, and a flow path is formed through which fluid flows and which has an outlet opening to the third surface and an inlet communicating with the outlet, wherein the contour of the outlet is convex in at least a part toward the second surface and has at least two straight portions.

2. The attachment according to claim 1, wherein at least a portion of the outline of the outlet, distinct from the convex portion, is arc-shaped or has at least two straight portions.

3. The attachment according to claim 1, wherein the contour of the outlet is such that the interior angle between the straight portion of the convex portion and the vertical direction is less than approximately 60°.

4. The attachment according to claim 1, wherein the contour of the outlet is such that the interior angle between the straight portion of the convex portion and the vertical direction is less than approximately 45°.

5. The attachment according to claim 1, wherein the contour of the outlet is such that the interior angle between the straight portion of the convex portion and the vertical direction is approximately 45°.

6. The attachment according to claim 1, wherein the flow path comprises an inlet passage including the inlet, an outlet passage including the outlet, and an intermediate passage connecting the inlet passage and the outlet passage and curving.

7. The attachment according to claim 6, wherein the intermediate path is arc-shaped.

8. The attachment according to claim 1, wherein, in a cross-sectional view in the extending direction of the flow path, the maximum cross-sectional area of ​​the outflow passage is smaller than the minimum cross-sectional area of ​​the inflow passage.

9. The attachment according to claim 6, wherein the direction of extension of the inlet passage forms an arbitrary angle with the plane on the first surface, or is substantially perpendicular to the plane on the first surface.

10. The attachment according to claim 6, wherein in a cross section substantially perpendicular to the plane of the first surface and the third surface, and substantially bisecting the intermediate path, the radius of curvature on the inside of the intermediate path is smaller than the radius of curvature on the outside of the intermediate path.

11. A cutting tool comprising an attachment, wherein the attachment has: a first surface including a plane, a second surface opposite to the first surface, and a third surface connecting the first surface and the second surface, the second surface having a mounting portion that can engage or fit with other parts constituting the cutting tool, and a flow path formed therein having an outlet through which a fluid flows and opening to the third surface, and an inlet communicating with the outlet, the contour of the outlet being convex in at least a portion toward the second surface and having at least two straight portions.

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