Tool body and cutting tool containing it

Abstract

This allows for the appropriate supply of coolant in both so-called front-turning and back-turning processes. [Solution] The cutting tool body 10 comprises a mounting seat 21 for a cutting insert provided on the tip end 10t side along the central axis 10X, a cylindrical portion 30 provided on the base end 10b side opposite to the tip end 10t along the central axis 10X, a fluid inlet 46 provided on the base end face 35 of the cylindrical portion 30 facing the base end 10b side, a fluid flow path 90 extending from the fluid inlet 46 toward the tip end 10t and branching at a branching point 94 along the way, a first fluid outlet 95A provided on the tip side 10t, and a second fluid outlet 95B provided on the side.

Description

Technical Field

[0001] The present invention relates to a tool body and a cutting tool including the same.

Background Art

[0002] For the purpose of supplying coolant toward the cutting edge in a cutting tool, there are purposes such as improving chip discharge performance and improving tool life. In particular, with regard to improving tool life as in the latter case, the cost and time related to tool replacement are reduced, and the environmental load due to reducing the discarded tools is reduced, and it can be said that the merits are great.

[0003] In order to improve tool life, it is effective to supply coolant toward the flank face near the corner close to the cutting edge. Conventionally, from such a viewpoint, as a coolant flow path, a technique of providing a coolant discharge port protruding from the insert tip has been proposed (see, for example, Patent Documents 1 and 2).

[0004] However, in the case of a cutting tool for internal diameter machining, since contact with the workpiece occurs, it becomes difficult to form the coolant discharge port in a shape protruding from the insert tip as described above. Also, in back turning (a machining method in which the cutting tool is fed in a direction opposite to that of normal lathe machining, also called under turning or the like), since the unprocessed portion remains in front, there may occur a problem that the coolant is blocked by the workpiece with the above-described supply method.

[0005] In consideration of such problems and restrictions, there are techniques that limit the improvement of chip discharge performance only when supplying coolant in internal diameter machining (see, for example, Patent Documents 3 and 4), and techniques aiming at improving tool life by eliminating restrictions (see, for example, Patent Document 5).

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

[0007] However, the above-mentioned technologies, such as the one described in Patent Document 5, are limited to one-way turning (reverse turning) and are therefore unsuitable for reverse turning.

[0008] Therefore, the present invention aims to provide a tool body and a cutting tool including it that can supply coolant appropriately in both so-called front turning and back turning operations. [Means for solving the problem]

[0009] One aspect of the present invention is a tool body for a cutting tool, A mounting seat for a cutting insert is provided on the tip side along the central axis, A cylindrical portion is provided on the base end side, which is opposite to the tip, along the central axis, A fluid inlet is provided on the base end surface facing the base end of the cylindrical portion, A fluid channel extending from the fluid inlet toward the tip and branching at an intermediate branching point, A first fluid outlet is provided at the tip, A second fluid outlet is provided on the side, This is a tool body equipped with [a specific feature / feature].

[0010] In a tool body of this type, it is possible to supply a fluid such as coolant appropriately from a first fluid outlet during front turning and a fluid such as coolant appropriately from a second fluid outlet during back turning. With such a tool body, it is possible to improve not only chip evacuation but also tool life.

[0011] In the tool body described above, the fluid flow path includes a first fluid branch path that connects from the branching point to a first fluid outlet, and a second fluid branch path that connects from the branching point to a second fluid outlet. The first fluid branch path may change direction toward the first fluid outlet along its course, and the second fluid branch path may change direction toward the second fluid outlet along its course.

[0012] In the tool body described above, the first fluid outlet may be provided on a first projection located on the tip side, and the second fluid outlet may be provided on a second projection located on the side.

[0013] In the tool body described above, the first fluid branching channel may change the direction of its flow path inside the first projection, and the second fluid branching channel may change the direction of its flow path inside the second projection.

[0014] In the tool body described above, the first fluid outlet may be provided to discharge fluid toward the tip corner of the mounting seat or upward thereto.

[0015] In the tool body described above, the second fluid outlet may be provided to discharge fluid toward the middle part of the side of the mounting seat or toward the area above it.

[0016] In the tool body described above, at least one of the first fluid outlet and the second fluid outlet may have an elongated hole shape.

[0017] In the tool body described above, the second fluid outlet may be an elongated hole extending along the side surface of the tool body.

[0018] In the tool body as described above, the base end face of the cylindrical portion may be composed of a serrated portion, and a fluid inlet may be provided in the serrated portion.

[0019] The tool body as described above may be a replaceable head that is detachable from the shank.

[0020] The tool body as described above may be formed by additive manufacturing.

[0021] Another aspect of the present invention is a cutting tool including the tool body as described above.

Brief Description of the Drawings

[0022] [Figure 1] It is a perspective view showing an example of the structure around the head of a head-exchangeable cutting tool in an embodiment of the present invention. [Figure 2] It is a perspective view of the head periphery of the head-exchangeable cutting tool seen from another angle. [Figure 3] It is an exploded perspective view showing an example of the structure around the head of the head-exchangeable cutting tool. [Figure 4] It is an exploded perspective view of the head periphery of the head-exchangeable cutting tool seen from another angle. [Figure 5] It is an exploded perspective view of the head periphery of the head-exchangeable cutting tool seen from yet another angle. [Figure 6] It is a perspective view showing an enlarged view of the head periphery of the head-exchangeable cutting tool. [Figure 7] It is a perspective view showing an example of the structure of the head of the head-exchangeable cutting tool. [Figure 8] It is a perspective view of the head seen from the base end portion side. [Figure 9] It is a perspective view of the head seen from the side where the flat surface of the cylindrical bottom is present. [Figure 10] It is a front view of the head seen from the tip side along the central axis. [Figure 11]This is a top view showing an example of the head structure of a head-exchangeable cutting tool in one embodiment of the present invention. [Figure 12] This is an enlarged view showing an example of the structure of the first projection and the first coolant outlet provided on the head. [Figure 13] This is a perspective view showing an example of a head structure, including its internal structure, as seen through the lens. [Figure 14] This is a top view showing the area near the tip of the head to which the cutting insert is attached. [Figure 15] This diagram shows a magnified example of the gap between the cutting insert and the workpiece, towards which the coolant flowing out from the second coolant outlet is directed. [Figure 16] This figure shows an example of the structure of the second coolant outlet, which has an elongated hole shape, and its surrounding area. [Figure 17] This diagram shows the cutting tool head and other components when the inner diameter of a workpiece is being machined. [Figure 18] This diagram illustrates the relative position of the first coolant outlet of the head and the workpiece during front turning. [Figure 19] This figure shows the state in which coolant is flowing out of the first coolant outlet of the head shown in Figure 18. [Figure 20] This diagram shows the cutting tool head and other components when the inner diameter of a workpiece is being turned. [Figure 21] Figure 20 shows a cross-section of the XXI-XXI line, specifically the area directly below the corner of the cutting insert (the area enclosed by the ellipse in the figure). [Figure 22] This is a view of the area directly below the corner shown in Figure 21 (the area enclosed by the ellipse) from the base end side of the head. [Figure 23] This figure shows a magnified portion of Figure 20, along with the trajectory of the coolant flowing out of the second coolant outlet. [Figure 24] Figure 23 shows the part of the head as viewed from the base end side. [Modes for carrying out the invention]

[0023] Hereinafter, preferred embodiments of the tool body and cutting tool including the same according to the present invention will be described in detail with reference to the drawings (see Figure 1, etc.).

[0024] The cutting tool of this embodiment is a head-exchangeable cutting tool 1. The head-exchangeable cutting tool 1 is configured to cut into the workpiece (material to be cut) 100 by advancing the cutting edge 71 of the cutting insert 70 during machining on an automatic lathe (not shown) or the like (see Figures 17 and 20). The head-exchangeable cutting tool 10 of this embodiment, used for such turning operations, is a head-exchangeable cutting tool in which the head 10 can be attached to and detached from the shank 80. It comprises the shank 80 and the head 10, as well as a head fixing screw (fixing member) 50 for fixing the head 10 to the shank 80 (see Figures 1 to 6, etc.). In this specification, the term "tool body" is used to refer to the part of the cutting tool excluding the cutting insert, or the parts that make up that part (for example, the head 10 described above).

[0025] In the following, we will first describe the general structure of the shank 80, the external structure of the head 10, and the general structure of the cutting insert 70, and then describe the fluid flow path and its surrounding structure located inside the head 10.

[0026] [shank] The shank 80 has a substantially cylindrical shape with a pair of gripping surfaces 82A, which are parallel to each other and located above and below the circumferential surface 81 (see Figure 1, etc.). A flat surface 82B may be provided on the side of the circumferential surface 81. The shank 80 of this embodiment has a shape that extends longitudinally along a central axis 80X (see Figure 5) passing through the center of the gripping portion 83 on which the gripping surfaces 82A are provided, and a head mounting surface 84 is provided at the tip portion (the side to which the head 10 is attached and detached) 80t (see Figure 3, etc.).

[0027] The head mounting surface 84 is provided with a coolant outlet 86 and screw holes 87 for fixing the head (see Figures 3 and 5). The coolant outlet 86 is the end opening of a coolant flow path 85 located inside the shank 80, and is located, for example, approximately in the center of the head mounting surface 84, from which coolant is supplied to the head 10. The screw holes 87 for fixing the head are screw holes with internal threads into which the head fixing screws 50 are screwed, and for example, four of them are arranged at equal intervals in the circumferential direction (see Figures 3 and 5).

[0028] [head] The head 10 is a replaceable head that can be attached to and detached from the head mounting surface 84 of the shank 80. The head 10 of this embodiment is designed on the premise that it will be manufactured by additive manufacturing, which offers a high degree of design freedom. For example, the cylindrical portion 30, which is the part of the shank 80 that faces the head mounting surface 84, is located on the base end 10b side, and the portion other than the cylindrical portion 30 (hereinafter referred to as the "front part of the head," and shown as reference numeral 20 in the figures) is located on the tip end 10t side (see Figures 3, 7, etc.).

[0029] The cylindrical portion 30 is a portion formed in a substantially cylindrical or disc shape, having a circumferential surface 31 that is approximately the same diameter as the circumferential surface 81 of the shank 80. The circumferential surface 31 of the cylindrical portion 30 is provided with a cylindrical upper flat surface 32, a cylindrical bottom flat surface 33, and a cylindrical side flat surface 34. The cylindrical upper flat surface 32 is provided on the upper part of the circumferential surface 31 of the cylindrical portion 30 (see Figure 7, etc.). Here, "upper part" refers to the part facing upward in Figure 10, or in other words, the part vertically above the gripping surface 82A that is on the upper side when the head 10 is attached to the shank 80 (see Figure 3, etc.). The cylindrical bottom flat surface 33 is provided on the bottom side opposite to the cylindrical upper flat surface 32 (see Figure 9). The cylindrical side flat surface 34 is provided on only one of the two sides of the circumferential surface 31 of the cylindrical portion 30 (see Figures 9 and 10). The upper flat surface 32 and the side flat surface 34 of the cylinder are flat surfaces formed by cutting out a portion of the circumferential surface 31. The bottom flat surface 33 of the cylinder is a flat surface that extends from a portion of the circumferential surface 31 to the bottom surface of the front of the head 20 (see Figure 9).

[0030] The surface roughness of the circumferential surface 31 of the cylindrical portion 30, excluding the upper flat surface 32, the lower flat surface 33, and the side flat surfaces 34 of the cylindrical portion is the surface roughness of the molded surface, i.e., the surface roughness as it is after additive manufacturing. In contrast, the upper flat surface 32 of the cylindrical portion has a surface roughness that is smaller than that of the circumferential surface 31, for example, by cutting a part of the surface after additive manufacturing, or by cutting and shaping a part of the circumferential surface 81 after additive manufacturing. The fact that the surface roughness of the upper flat surface 32 is smaller than that of the other parts is advantageous in that it can improve the accuracy of phase alignment when a height gauge is applied to the upper flat surface 32 of the cylindrical portion for phase alignment. In this embodiment, by making the surface roughness smaller and the surface finer in parts that are suitable for improving processing accuracy or measurement accuracy, it is possible to appropriately improve accuracy while retaining the advantages of additive manufacturing (inexpensive, lightweight, easy to manufacture, etc.). From this perspective, the surface roughness of the cylindrical bottom flat surface 33 and the cylindrical side flat surface 34 can remain the same as the surface roughness of the circumferential surface 31 (the same as the molded surface).

[0031] It should be noted that the term "surface roughness" (sometimes called "surface texture") used in this specification is similar to the term "surface characteristics." In some literature, the term "surface characteristics" is explained as referring to the state of fine irregularities, undulations, and streaks found on the surface of a product, and is quantified and evaluated using the index "surface roughness." In light of this explanation, it would be conceivable to use the term "surface characteristics" in this specification, but in this specification, we will use "surface roughness" in a narrower sense. However, in light of the content of this explanation and the gist of the present invention, there is no problem in using the term "surface characteristics" instead of "surface roughness." Incidentally, surface roughness is expressed using an index such as the arithmetic mean roughness (Ra) of the cross-sectional curve.

[0032] The base end surface 35 of the cylindrical portion 30, facing the base end 10b side, is the surface that is mounted on the head mounting surface 84 of the shank 80. A coolant inlet 46 is provided approximately in the center of the base end surface 35 so as to communicate with the coolant outlet 86 of the head mounting surface 84 (see Figures 3 and 4). A cylindrical connecting member 47 may be placed between the coolant outlet 86 and the coolant inlet 46. In this embodiment, both the base end surface 35 and the head mounting surface 84 of the shank 80 are serrated (indicated by the symbol S in the figures) to create a sawtooth shape that interlocks with each other (see Figures 3 and 4, etc.). In this embodiment, both of these sawtooth base end surfaces 35 and the head mounting surface 84 of the shank 80 are machined surfaces, and the surface roughness is made smaller than, for example, the surface roughness of the circumferential surface 31, thereby improving the positional accuracy when the head 10 is mounted on the shank 80 (see Figures 1 and 2). The serrations S are merely one example of the form of both the base end face 35 and the head mounting surface 84 of the shank 80. Although not specifically shown in the illustrations, both of these surfaces, the base end face 35 and the head mounting surface 84 of the shank 80, can have forms other than serrations, such as a form with a keyway.

[0033] A mounting seat 21 for a cutting insert 70 is provided on the front part 20 of the head 10 (the part other than the cylindrical part 30) (see Figures 5, 6, etc.). This mounting seat 21 has a bottom surface 22 and a wall surface 23. The bottom surface 22 is the surface on which the cutting insert 70 is directly or indirectly placed and serves as the position reference for the height of the cutting edge 71 (referring to the position in the upward direction). The wall surface 23 is a surface that extends directly or indirectly in the height direction to the bottom surface 22. In this embodiment, the mounting seat 21 of the head 10 can not only directly place the cutting insert 70 on it, but can also be placed with a base plate 61 in between (see Figures 3 to 5). For this reason, in this head 10, a wall surface 22w that abuts against at least a part of the side surface of the base plate 61 and a second bottom surface 22b that abuts against a part of the bottom surface of the cutting insert 70 are provided between the bottom surface 22 and the wall surface 23 (see Figure 7, etc.). The wall surface 22w consists of, for example, a wavy surface that is connected to the bottom surface 22 substantially perpendicularly. The second bottom surface 22b consists of a surface that is connected to this wall surface 22w and is substantially horizontal to the bottom surface 22. The aforementioned wall surface 23 is provided so as to be connected to this second bottom surface 22b substantially perpendicularly (see Figure 7, etc.). The bottom surface 22 is also provided with screw holes 24 for fixing the security deposit 61 into which security deposit fixing screws 62 are screwed (see Figures 7 and 8). The mounting seat 21 of this embodiment, which has this shape, is machined after additive manufacturing so that its surface roughness (in this embodiment, at least both the surface roughness of the bottom surface 22 and the surface roughness of the wall surface 23 that constitute the mounting seat 21) is smaller than the surface roughness of the circumferential surface 31 of the cylindrical portion 30.

[0034] Furthermore, the cylindrical portion 30 is provided with through holes 40 and counterbores 41. The through holes 40 are holes that penetrate from the surface on the tip 10t side of the cylindrical portion 30 to the base end surface 35, and there are multiple such holes, for example, three (see Figure 4, etc.). Corresponding to these through holes 40, the head mounting surface 84 of the shank 80 has multiple screw holes 87 for fixing the head arranged parallel to the central axis 80X (see Figure 3, etc.). All of these through holes 40 may be circular, but they may also have different shapes. In the head 10 of this embodiment, of the three through holes 40, the through hole closest to the second plane 12 (indicated by reference numeral 40L) is an elongated hole (see Figures 3, 10, etc.). In a front view of the head 10 from the tip 10t side along the central axis 10X, if the first plane 11 overlaps with a part of the through hole 40L, the head fixing screw 50 may interfere with the clamp member 60 when fastening, making it difficult or impossible to install the head fixing screw 50. In this regard, with the head 10 of this embodiment, the screw portion of the head fixing screw 50 can be inserted into the through hole 40L while tilting it to avoid interference with the clamp member 60 (see Figure 6), and after inserting it to a certain extent, the head fixing screw 50 can be made parallel to the central axis 10X (and central axis 80X) and rotated to fasten it (see Figures 3 to 6).

[0035] The counterbores 41 are provided around each of the multiple through holes 40 described above (see Figures 6 and 7, etc.). At least one of these multiple counterbores 41 may have a shape in which a part of it opens into the circumferential surface 31 of the cylindrical portion 30. By removing the portion that becomes thinner due to the provision of the counterbore 41 in advance, it is possible to reduce the risk of cracking or other damage occurring during or after molding. In the head 10 of this embodiment, all of the counterbores 41 provided around each of the three through holes 40 have a shape in which they open into the circumferential surface 31 of the cylindrical portion 30 (see Figures 7 and 10, etc.).

[0036] Furthermore, the head 10 is provided with ribs 42 and weight-reducing recesses 43. Of these, the ribs 42 are shaped to connect to one of the counterbores 41, and are provided in a way that makes it easier to ensure strength in a predetermined area while reducing weight. In this embodiment, a rib 42 is provided that extends from the cylindrical part 30 to the front part of the head 20, connected to the rib 42 located in the upper left of Figure 10, and connects to one of the first plane 11 to the third plane 13 (in this embodiment, the second plane 12) (see Figures 2, 10, etc.). The part where the ribs 42 are provided corresponds to a region where bending stress acts greatly during cutting, or a region close to it.

[0037] The weight-reducing recesses 43 are provided in such a way that a portion of the head 10 is removed in order to reduce the weight of the head 10 while ensuring a predetermined strength. Incidentally, when removing the same area / volume, since the main component of the cutting force acts mainly in the vertical direction, if the bending stress in the vertical direction is emphasized, it can be said that the closer the shape is to an I shape when viewed from the front, the more advantageous it is in that it is easier to obtain the second moment of area (see Figure 10). In this embodiment, the weight-reducing recesses 43 are provided such that the depth of the recesses increases as they approach the tip portion 10t of the head 10 (see Figures 2, 9, etc.). In other words, such weight-reducing recesses 43 can be said to have a shape that moves closer to the center of the front part 20 of the head (i.e., the central axis 10X of the head 10) as it approaches the tip portion 10t of the head 10 (see Figure 10, etc.).

[0038] The clamp member 60 is a member for clamping and fixing the cutting insert 70 (together with the base plate 61 in this embodiment) which is attached to a predetermined position on the mounting seat 21. The clamp member 60 in this embodiment has the shape of a leg portion 60L, a pressure-bearing surface 60P, a clamp inclined surface 60S, and a protruding portion 60T. The protruding portion 60T is fitted into the through hole 72 in the center of the cutting insert 70 attached to a predetermined position on the mounting seat 21, the end of the leg portion 60L is inserted into the clamp recess 11C of the first plane 11, and with the clamp inclined surface 60S in contact with the third plane 13, the clamp fixing screw 63 is passed through the clamp fixing screw hole 11H, and the clamp fixing screw 63 is rotated to press the pressure-bearing surface 60P, thereby clamping the cutting insert 70, etc. (see Figures 3 to 5).

[0039] The head 10, with the cutting insert 70 and the like clamped and fixed by the clamping member 60, can be attached to and detached from the head mounting surface 84 of the shank 80 by tightening or loosening the head fixing screw 50 while maintaining this state (see Figures 3, 6, etc.). When the head 10 is attached to the head mounting surface 84, the serrations S of the base end surface 35 and the serrations S of the head mounting surface 84 interlock with each other, so that the relative position of the head 10 with respect to the shank 80 in one direction (the vertical direction where the peaks and valleys of the sawtooth are aligned) is uniquely defined. In addition, by tightening the head fixing screw 50, the lateral relative position of the head 10 with respect to the shank 80 is also uniquely defined.

[0040] [Cutting inserts] The cutting insert 70 cuts into the workpiece (material to be cut) 100 using its cutting edge 71. The cutting insert 70 shown in the drawing (Figure 3, etc.) has three corners on each side, for a total of six corners, but this is just one example, and other structures may be used, such as a cutting insert 70 with two corners on each side, for a total of four corners. Also, the cutting insert 70 shown in the drawing (Figure 3, etc.) is a negative insert with no relief angle, but a positive insert with a relief angle may be used instead.

[0041] In this embodiment of the interchangeable head cutting tool 1, the surface roughness of the mounting seat 21, which is the mounting area of ​​the cutting insert 70, is reduced by machining, for example, to improve the accuracy during mounting, while the remaining parts retain the surface texture created during additive manufacturing. This configuration makes it possible to overcome the deterioration of accuracy when mounting components together while retaining the advantages of additive manufacturing. In particular, this embodiment is characterized by the fact that the surface roughness of both the first plane 11 and the wall surface 23 that constitute the ridge line 15 is reduced by machining, for example, to smooth the surface, thereby increasing the positional accuracy of the ridge line 15 and further improving the positioning accuracy of the constrained position of the cutting insert 70. In such an interchangeable head cutting tool 1, the repeatability during corner changes of the cutting insert 70 and the repeatability during replacement of the head 10 are improved, and consequently, the machining accuracy of the workpiece 100 is improved. From a similar viewpoint, in this embodiment, the surface roughness of the upper flat surface 32 of the cylinder used for phase setting using a height gauge is also reduced by machining, for example. Furthermore, another advantage is that the additively manufactured head 10 is inexpensive and lightweight.

[0042] The interchangeable head cutting tool 1 is used for internal diameter turning and the like with the head 10, which has a cutting insert 70 mounted on a mounting seat 21, attached to the shank 80. The machining direction of the interchangeable head cutting tool 1 is not particularly limited. The interchangeable head cutting tool as in this embodiment can be applied to both front turning, where the interchangeable head cutting tool 1 is moved in the direction of the tip 10t of the head 10, and back turning, where the interchangeable head cutting tool 1 is moved in the direction of the base 10b (see Figures 17 and 20).

[0043] [The fluid channel located inside the head and its surrounding structure] The head-exchangeable cutting tool 1 of this embodiment is equipped with a flow path for supplying coolant (indicated by the symbol C in Figure 14, etc.) toward the cutting edge 71 of the cutting insert 70 during cutting. To configure such a flow path, the head 10 is provided with a coolant flow path (fluid flow path) 90, a first coolant branch (first fluid branch) 90A, a second coolant branch (second fluid branch) 90B, a third coolant branch 90C, a coolant inlet (fluid inlet) 93, a branching point 94, a first coolant outlet (first fluid outlet) 95A, a second coolant outlet (second fluid outlet) 95B, and furthermore, a first projection 91 and a second projection 92 are provided (see Figure 11, etc.).

[0044] The coolant passage 90 is a fluid passage (coolant in this embodiment) located inside the head 10. This coolant passage 90 extends from a coolant inlet 46 located approximately in the center of the base end face 35 toward the tip 10t, and branches at a branching point 94 into a first coolant branch passage 90A, a second coolant branch passage 90B, and a third coolant branch passage 90C. The first coolant branch passage 90A communicates from the branching point 94 to a first coolant outlet 95A located on the tip side of the head 10 (for example, on the tip-facing surface on the tip side of the head 10). The first coolant branch passage 90A also changes direction midway toward the first coolant outlet 95A. The second coolant branch passage 90B communicates from the branching point 94 to a second coolant outlet 95B located on the side of the head 10. The second coolant branch channel 90B also has a shape that changes the direction of its flow path midway towards the second coolant outlet 95B (see Figure 11, etc.). The third coolant branch channel 90C is connected from the branching point 94 to the inside of the clamp member 60.

[0045] The first projection 91 is provided on the front surface (indicated by reference numeral 26 in Figure 11, etc.), which is the surface of the front part of the head 20 that faces towards the tip. In this embodiment, the first projection 91 is a roughly semi-pillar-shaped protrusion that extends parallel to the bottom surface 22 of the mounting seat 21 below the bottom surface 22 (see Figures 12, 13, etc.). The first projection 91 is also provided with the first coolant outlet 95A described above. Such a structure is suitable because it is easy to control the flow and direction of the coolant C flowing out from the first coolant outlet 95A according to the shape of the first projection 91 so that it can be supplied to a desired position. For example, in this embodiment, the first coolant outlet 95A and the first projection 91 are provided so as to cause the coolant C to flow out toward the front corner portion of the mounting seat 21 (the pointed portion closest to the tip of the bottom surface 22 of the mounting seat 21, indicated by reference numeral 21c in Figure 11, etc.) or the area above it. The tip corner portion 21c or the area above it is the area where the corner portion 73 on the upper surface 70u side of the cutting insert 70 is located when the cutting insert 70 is mounted on the mounting seat 21 (see Figure 14). Generally, during front turning (see Figure 17), there is sufficient space between the cutting insert 70 and the workpiece 100 directly below the corner portion 73 of the cutting insert 70 (see the elliptical portion in Figure 18). Therefore, in the head-exchangeable cutting tool 1 of this embodiment, it is possible to directly supply coolant C to the vicinity of the corner portion 73 on the upper surface 70u side of the cutting insert 70, and especially to the vicinity of the cutting edge 71 used for cutting during front turning (see Figure 19). To make this effect even more effective, the direction of the flow path of the first coolant branch passage 90A may be appropriately changed inside the first projection 91. In the head-exchangeable cutting tool 1 of this embodiment, the first projection 91, which is generally parallel to the bottom surface 22, is bent midway so that it slopes upward near the first coolant outlet 95A (see Figure 12). This shape or structure makes it possible to supply coolant C more directly and effectively to the vicinity of the cutting edge 71 used for cutting during front turning.

[0046] The second projection 92 is provided on the side surface (indicated by reference numeral 27 in Figure 11, etc.) of the front part of the head 20, which faces the side of the mounting seat 21. In this embodiment, the second projection 92 is shaped to protrude from the side surface 27 below the second plane 12 (see Figures 12, 13, etc.). The second projection 92 is also provided with the second coolant outlet 95B described above. Such a structure is suitable because it is easy to control the flow and direction of the coolant C flowing out of the second coolant outlet 95B according to the shape of the second projection 92 so that it can be supplied to a desired position. For example, in this embodiment, the second projection 92 and the second coolant outlet 95B are provided such that the second coolant outlet 95B flows out the coolant C toward the middle part of the side of the mounting seat 21 or a region above it (see Figure 14, etc.). The intermediate portion or the region above it corresponds to the gap G between the cutting insert 70 and the workpiece 100 when the cutting insert 70 is mounted on the mounting seat 21 (see Figure 15, etc.). During back turning (see Figure 20), the second projection 92 or the second coolant outlet 95B provided thereon may interfere with the workpiece 100. In that case, there is not enough space directly below the corner portion 73 of the cutting insert 70 (see the elliptical portion in Figures 21 and 22), making it difficult to directly supply coolant C to the vicinity of the corner portion 73 on the upper surface 70u side of the cutting insert 70, and especially to the vicinity of the cutting edge 71 used for cutting during back turning. Taking this into consideration, in the head-exchangeable cutting tool 1 of this embodiment, the coolant C is directed not to directly target the corner portion 73 of the cutting insert 70, but to flow out through the gap G between the cutting insert 70 and the workpiece 100 (see Figures 23 and 24). To make this effect even more effective, the direction of the flow path of the second coolant branch passage 90B may be appropriately changed inside the second projection 92. Also, the second coolant outlet 95B (or the first coolant outlet 95A) may be elongated. In the head-exchangeable cutting tool 1 of this embodiment, the second coolant outlet 95B is elongated, extending along the side surface 27 of the front part 20 of the head 10 (see Figure 16, etc.).As described above, when directing coolant C to flow out through the gap G between the cutting insert 70 and the workpiece 100, making the shape of the second coolant outlet 95B an elongated hole rather than a perfect circle makes it easier to target the gap G and allows for more efficient supply of coolant C.

[0047] Let me elaborate a little on the first projection 91 and the second projection 92 described above. One of the aims of providing these projections on the head 10 is that, although it would be desirable to spray and supply coolant C into the narrow gap G between the relief surface (the tip surface 26 and side surface 27) 74 and the workpiece 100 so as to be as parallel as possible to the relief surface, it is necessary to allow clearance so as not to interfere with the workpiece 100, hence the use of these projections. In short, in this embodiment, while assuming that a predetermined relief surface 74 is necessary for the function of the head 10 and the cutting insert 70, the first projection 91 and the second projection 92 are provided in a manner that does not hinder (does not interfere with) that function, and the first coolant outlet 95A and the second coolant outlet 95B are provided on each.

[0048] With the interchangeable head cutting tool 1 of this embodiment as described above, coolant C is supplied appropriately from the first coolant outlet 95A during front turning and from the second coolant outlet 95B during back turning, thereby improving chip evacuation during cutting and extending tool life. Furthermore, in this interchangeable head cutting tool 1, the first coolant outlet 95A can be positioned particularly close to the cutting insert 70, which can lead to significantly improved cooling, lubrication, and tool life. Another advantage of the head 10 of this embodiment, which can be manufactured additively, is that it is inexpensive and lightweight.

[0049] The embodiments described above are merely examples of preferred implementations of the present invention, and are not limited thereto. Various modifications are possible without departing from the spirit of the invention. For example, the above embodiments described the structure of a replaceable head 10 that can be attached to and removed from the shank 80 as an example, but such a head 10 or a replaceable head cutting tool 1 including it is merely one preferred embodiment of the tool body according to the present invention. For example, the feature of reducing the surface roughness of the mounting seat 21 of the cutting insert 70 by machining, while leaving the other parts as they are, thereby overcoming the deterioration of accuracy when attaching components while retaining the advantages of additive manufacturing, can also be applied to other tool bodies, for example, non-replaceable head cutting tools, such as a shank-integrated type tool body in which the head (the part corresponding to the head 10) is integrated with the shank, or the tool body of a cutting tool (such as an external turning tool or a grooving tool) in which the head (the part corresponding to the head 10) is brazed to the main body part such as the shank of the cutting tool.

[0050] Furthermore, although the shapes and structures of the first coolant outlet 95A and the second coolant outlet 95B were illustrated and described in the above-described embodiment, this is merely a preferred example. Other embodiments are possible, such as an embodiment with three or more coolant outlets, an embodiment in which both the first coolant outlet 95A and the second coolant outlet 95B are circular in shape, or an embodiment in which the first coolant outlet 95A and the second coolant outlet 95B are directly provided on the wall surface (tip surface 26, side surface 27) of the head 10 without providing any protrusions (first protrusion 91, second protrusion 92). Also, although the above-described embodiment illustrates an embodiment in which the third coolant branch passage 90C communicates from the branching point 94 to the inside of the clamp member 60, this is also merely a preferred example, and an embodiment without such a third coolant branch passage 90C is also possible.

[0051] Furthermore, in the embodiments described above, the fluid that flows inside the head 10 and is supplied to the cutting insert 70 is described as coolant C, but this is only one preferred example. In embodiments where a fluid such as air or mist (where mist is a mixture of air and sprayed coolant) is supplied instead of coolant C, the head 10 described above or the interchangeable head cutting tool 1 including it can also be applied. [Industrial applicability]

[0052] This invention is preferably applied to tool bodies and cutting tools containing them. [Explanation of symbols]

[0053] 1… Interchangeable head cutting tool (cutting tool) 10... Head (tool body) 10b...Proximal end 10t...Tip 10X…center axis 11…1st plane 11C…Recess for clamping 11H…Hole for clamp fixing screw 12…Second plane 13…Third plane 15…Ridge (formed between the wall surface and the first plane) 20... Front of the head 21…Mounting base 21c...Front corner 22…Bottom surface (of the mounting base) 22b…Second bottom surface 22w...wall 23…(The wall surface of the mounting base) 24... Screw holes for securing the security deposit 26…Tip surface 27... Side view 30...Cylindrical section 31...peripheral surface 32… Flat surface at the top of the cylinder 33…Flat surface at the base of the cylinder 34…Flat surface on the side of a cylinder 35...Proximal surface 40…Through hole 40L…long hole 41... Zagri 42... Rib 43...Recessed area 46…Coolant inlet (fluid inlet) 47...Cylindrical connecting member 50...Head fixing screw (fixing component) 60... Clamp member 60L…legs 60P...Pressed surface 60S… Clamp Inclined Surface 60T…projection 61…Security deposit 62... Deposit fixing screw 63... Clamp fixing screw 70…Cutting insert 70u…Top surface 71... Cutting edge 72... Through hole 73...Corner section 74...Fleeing face 80... Shank 80t...tip 80X…center axis 81...peripheral surface 82A…Gripped surface 82B…Flat surface 83...Gripped part 84...Head mounting surface 85…Coolant flow path 86... Coolant outlet 87... Screw holes for fixing the head 90... Coolant flow path (fluid flow path) 90A...First coolant branch (first fluid branch) 90B...Second coolant branch (second fluid branch) 90C... Third Coolant Junction 91...first protrusion 92…Second protrusion 94...Turning point 95A...First coolant outlet (first fluid outlet) 95B...Second coolant outlet (second fluid outlet) C... Coolant (fluid) G... Gap S... Serration (sawtooth-shaped part) 100...Workpiece (material to be machined)

Claims

1. The tool body of a cutting tool, A mounting seat for a cutting insert is provided on the tip side along the central axis, A cylindrical portion is provided on the base end side opposite to the tip end along the central axis, A fluid inlet is provided on the base end surface of the cylindrical portion facing the base end side, A fluid channel extending from the fluid inlet toward the tip and branching at an intermediate branching point, A first fluid outlet is provided at the tip, A second fluid outlet is provided on the side, Equipped with, A tool body in which the first fluid outlet is provided on a first projection that is additively fabricated on the tip side of the tool body, or the second fluid outlet is provided on a second projection that is additively fabricated on the side of the tool body.

2. The tool body according to claim 1, wherein the fluid flow path includes a first fluid branch path communicating from the branching point to the first fluid outlet, and a second fluid branch path communicating from the branching point to the second fluid outlet, wherein the first fluid branch path has a shape that changes the direction of the flow path toward the first fluid outlet along its course, and the second fluid branch path has a shape that changes the direction of the flow path toward the second fluid outlet along its course.

3. The tool body according to claim 2, wherein the first fluid outlet is provided on a first projection provided on the tip side, and the second fluid outlet is provided on a second projection provided on the side.

4. The tool body according to claim 3, wherein the first fluid branch changes direction of flow within the first projection, and the second fluid branch changes direction of flow within the second projection.

5. The tool body according to claim 4, wherein the first fluid outlet is provided to discharge fluid toward the tip corner portion of the mounting seat or upward thereof.

6. The tool body according to claim 4, wherein the second fluid outlet is provided to discharge fluid toward the intermediate portion of the side of the mounting seat or toward the upper part thereof.

7. The tool body according to any one of claims 2 to 6, wherein at least one of the first fluid outlet and the second fluid outlet is elongated.

8. The tool body according to claim 7, wherein the second fluid outlet is an elongated hole shape extending along the side surface of the tool body.

9. The tool body according to any one of claims 2 to 6, wherein the base end surface of the cylindrical portion is composed of a serrated portion, and the fluid inlet is provided in the serrated portion.

10. A tool body according to any one of claims 2 to 6, wherein the head is interchangeable and detachable from the shank.

11. A tool body according to any one of claims 2 to 6, which is manufactured by additive manufacturing.

12. A cutting tool comprising a tool body according to any one of claims 2 to 6.

Images