Joint component

Abstract

The present invention provides a joint component capable of smoothly supplying a fluid to a cutting position without limiting a cutting width. A joint component 100 has a body part 30 in which a first fastening part 31 that can be fastened to a shank 10 that is a first fastened member is provided on one end side, and a second fastening part 32 that can be fastened to a head 20 that is a second fastened member is provided on the other end side. The joint component 100 has: a plurality of discharge flow paths 51 that open at a plurality of positions in a circumferential direction on the outer peripheral surface of the body part 30 on the other end side; and a supply flow path 52 that passes through the center axis Ax from the one end side of the body part 30 and is connected to the plurality of discharge flow paths 51.

Description

Joint parts

[0001] The present invention relates to a joint component.

[0002] Patent Document 1 discloses a cutting head that is removably fixed to a holder. Patent Document 2 discloses that such a cutting head is provided with an internal flow path for supplying a fluid, which is fed from a coupling portion for coupling to an arbor, to the cutting edge of the cutting blade. Patent Document 3 discloses a technology in which a member having multiple outlets around the periphery is attached to the tip of a cutting head made of a reamer with cutting blades, and fluid is sprayed from the outlets onto the cutting area.

[0003] JP-T-2021-504159 A JP-A-2009-61548 A U.S. Patent Application Publication No. 2020 / 0230716

[0004] However, in the cutting head described in Patent Document 2, the fluid is discharged in a direction toward the periphery, away from the cutting location, so there is a risk that the fluid may not be sufficiently supplied to the cutting location. Also, in the cutting head described in Patent Document 3, a separate component is attached to the tip of the cutting head, so the cutting width by the cutting head is limited.

[0005] The present invention has been made in view of the above circumstances, and has an object to provide a coupling part that can smoothly supply fluid to a cutting location without restricting the cutting width.

[0006] A coupling part according to one aspect of the present invention is a coupling part having a main body part with a first fastening portion at one end that can be fastened to a first fastened member and a second fastening portion at the other end that can be fastened to a second fastened member, and has a plurality of discharge flow paths that open at a plurality of circumferential positions on the outer peripheral surface of the other end of the main body part, and a supply flow path that runs from one end of the main body part through the central axis and is connected to the plurality of discharge flow paths.

[0007] In the coupling component with the above structure, the fluid supplied to the supply passage from one end side can be discharged from the multiple discharge passages opening on the outer peripheral surface of the other end side of the main body and effectively sprayed toward the second fastened member. This allows the fluid to be smoothly supplied to the vicinity of the cutting point of the second fastened member, which is made up of the head, for cooling and lubrication. Furthermore, compared to a structure in which a separate member with a passage is attached to the tip of the head, the cutting width is not limited.

[0008] The discharge flow path may open at an angle toward the central axis toward the other end of the main body.

[0009] The discharge flow path may be twisted in the same direction as the screwing direction of the first fastening portion into the first fastened member.

[0010] The supply flow path may have an axial flow path that runs from one end side of the main body portion through the central axis, and at least a portion of the axial flow path may be formed in a non-circular shape when viewed from the front.

[0011] The axial flow path may be formed in a polygonal shape when viewed from the front, and the supply flow path may further have a plurality of branch flow paths branching from each vertex of the polygon of the axial flow path and connecting to the discharge flow path.

[0012] Between the branch flow path and the discharge flow path, there is an annular flow path formed circumferentially around the main body portion, through which the branch flow path and the discharge flow path are connected, and the number of discharge flow paths may be greater than the number of branch flow paths.

[0013] The discharge flow path may have a cross-sectional area on the opening side at the reduced diameter portion that is smaller than the cross-sectional area on the side communicating with the annular flow path.

[0014] According to the present invention, a coupling part is provided that can smoothly supply fluid to a cutting location without restricting the cutting width.

[0015] FIG. 1 is a perspective view of a rotary cutting tool equipped with a joint part according to this embodiment. FIG. 2 is an exploded perspective view of the rotary cutting tool. FIG. 3 is a front view of the joint part as viewed from the leading end side. FIG. 4 is a front view of the joint part as viewed from the rear end side. FIG. 5 is a perspective view illustrating a flow path formed in the joint part. FIG. 6 is a side view illustrating a flow path formed in the joint part. FIG. 7 is a cross-sectional view taken along line VII-VII in FIG. 3. FIG. 8 is a cross-sectional view taken along line VIII-VIII in FIG. 3. FIG. 9 is a cross-sectional view taken along line IX-IX in FIG. 6. FIG. 10 is an enlarged view of part A in FIG. 8. FIG. 11 is an enlarged view of part B in FIG. 6.

[0016]

[0023] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. As shown in Figures 1 and 2, a joint part 100 according to this embodiment is a joint part to be fastened to fastened members. In this example, a case will be described in which a rotary cutting tool such as an end mill is fastened to a shank (first fastened member) 10 and a head (second fastened member) 20, and the shank 10 and head 20 are connected.

[0017] The shank 10 is mounted on, for example, a machine tool. The shank 10 has a mounting hole 12 with an internal thread 11 formed at its tip. The head 20 has a cutting blade 21 on its tip side. The head 20 has a mounting portion 23 with an external thread 22 formed at its rear end.

[0018] The coupling part 100 is interposed between the shank 10 and the head 20, for example, when the thread diameter of the internal thread 11 of the shank 10 and the thread diameter of the external thread 22 of the head 20 are different, to connect the shank 10 and the head 20. The coupling part 100 may also be interposed between the shank 10 and the head 20 when the length of the rotary cutting tool is to be extended, even if the thread diameter of the internal thread 11 of the shank 10 and the thread diameter of the external thread 22 of the head 20 are the same.

[0019] The joint part 100 has a main body 30 formed in a generally cylindrical shape, and the main body 30 has a larger diameter than the head 20. The joint part 100 has a first fastening part 31 at one end, i.e., the rear end, of the main body 30. The joint part 100 also has a second fastening part 32 at the other end, i.e., the front end, of the main body 30.

[0020] The first fastening portion 31 is formed in a cylindrical shape with a smaller diameter than the main body portion 30, and has an external thread 33 formed on its outer periphery. The first fastening portion 31 can be fastened to and unclamped from the mounting hole 12 having the internal thread 11 of the shank 10.

[0021] When the main body 30 of the joint part 100 is rotated in one direction, the first fastening portion 31 is threaded into and fastened to the mounting hole 12 of the shank 10, and when the main body 30 is rotated in the other direction opposite to the one direction, the first fastening portion 31 is loosened and released from the mounting hole 12 of the shank 10. The rotation direction in one direction when fastening the first fastening portion 31 of the main body 30 to the mounting hole 21 of the shank 10 is opposite to the rotation direction when the rotary cutting tool, which connects the shank 10 and head 20 by the joint part 100, is rotated to cut the workpiece. This prevents the joint part 100 from loosening from the shank 10 when cutting the workpiece.

[0022] The second fastening portion 32 has a fastening hole 35. An internal thread 36 is formed on the inner periphery of the fastening hole 35 of the second fastening portion 32. The second fastening portion 32 can be fastened to and unclamped from the attachment portion 23 having the external thread 22 of the head 20.

[0023] When the head 20 is rotated in one direction, the attachment portion 23 is screwed into and fastened to the fastening hole 35 of the second fastening portion 32 of the joint component 100, and when the head 20 is rotated in the other direction opposite to the one direction, the attachment portion 23 is loosened from the fastening hole 35 of the second fastening portion 32 of the joint component 100, and the fastening is released.

[0024] The rotation direction in one direction when fastening the attachment portion 23 of the head 20 to the fastening hole 35 of the joint part 100 is also opposite to the rotation direction when cutting a workpiece by rotating the rotary cutting tool in which the shank 10 and head 20 are connected by the joint part 100. This prevents the head 20 from loosening from the joint part 100 when cutting the workpiece.

[0025] 3 and 4, engagement holes 40A, 40B are formed on both ends inside the main body 30 of the joint part 100. In this example, the joint part 100 has a through hole in which the engagement holes 40A, 40B communicate with each other, with a boundary 45 as the boundary (see FIG. 7), with the engagement hole 40A on the front end side of the main body 30 and the engagement hole 40B on the rear end side of the main body 30. Note that the engagement holes 40A, 40B do not have to communicate with each other.

[0026] These engagement holes 40A, 40B are tool holes through which a wrench can be inserted and removed, and their respective center lines are parallel to the central axis Ax of the main body 30. These engagement holes 40A, 40B are each non-circular in front view. In this example, the engagement holes 40A, 40B are each regular hexagonal in front view, allowing a hexagonal wrench to be inserted and removed. By inserting a hexagonal wrench into the engagement holes 40A, 40B, the hexagonal wrench can engage around the central axis Ax of the main body 30. The engagement holes 40A, 40B have six inner wall surfaces 41, and relief recesses 42 are provided between adjacent inner wall surfaces 41, which are the vertices of the hexagons, to reduce interference with the edges of the hexagonal wrench and allow smooth insertion and removal.

[0027] When fastening or unclamping the first fastening portion 31 of the joint part 100 to the mounting hole 12 of the shank 10, a hex wrench is inserted from the tip side of the main body 30 into the engagement hole 40A, and the hex wrench is rotated in either direction while fixing the shank 10, thereby fastening or unclamping the joint part 100 to the shank 10.

[0028] Furthermore, the attachment portion 23 of the head 20 is fastened and unfastened to the second fastening portion 32 of the joint component 100 fixed to the shank 10. In this way, the head 20 is usually fastened and unfastened to the joint component 100 fastened and fixed to the shank 10. However, when the head 20 is rotated to remove the head 20 from the joint component 100, the joint component 100 may loosen and come off from the shank 10 together with the head 20. In such a case, the head 20 can be removed from the joint component 100 by inserting a hex wrench into the engagement hole 40B of the joint component 100 and rotating the head 20 while holding the hex wrench in place to prevent the joint component 100 from rotating.

[0029] In this way, the coupling part 100 has engagement holes 40A, 40B formed on both ends of the main body 30, so that a hex wrench can be inserted into either end and rotated around the central axis Ax.

[0030] 5 to 8 , the joint part 100 has a reduced diameter portion 37 on the tip side of the main body portion 30. This reduced diameter portion 37 is formed in a tapered shape that gradually narrows toward the second fastening portion 32. Providing this reduced diameter portion 37 on the main body portion 30 can, for example, suppress interference between the workpiece and the main body portion 30, and also suppress chips from hitting the main body portion 30 and bouncing back toward the workpiece during cutting. Note that the main body portion 30 is not necessarily limited to having the reduced diameter portion 37. For example, the main body portion 30 may have a straight shape that has a constant outer diameter toward the tip side.

[0031] The main body 30 of the joint part 100 has a discharge flow path 51 and a supply flow path 52. A plurality of discharge flow paths 51 are formed on the tip side of the main body 30. In this example, the main body 30 has eight discharge flow paths 51. These discharge flow paths 51 are formed at equal intervals in the circumferential direction of the main body 30. Each of these discharge flow paths 51 opens at a plurality of locations in the circumferential direction on the outer circumferential surface of the reduced diameter portion 37, and the openings of the discharge flow paths 51 in the reduced diameter portion 37 are discharge ports 51a. The supply flow path 52 is a flow path that runs from the rear end side of the main body 30, passes through the central axis Ax, and is connected to the plurality of discharge flow paths 51.

[0032] In the joint component 100, a fluid (coolant) is supplied from the shank 10 to which the first fastening portion 31 of the main body 30 is fastened to the supply flow passage 52. The fluid is then sent from the supply flow passage 52 to the discharge flow passage 51, and is discharged from the discharge ports 51 a that are openings of the discharge flow passages 51, and is sprayed near the cutting location of the workpiece by the head 20.

[0033] In this way, in the joint part 100, the fluid supplied from the shank 10 on the rear end side to the supply flow path 52 is discharged from the multiple discharge flow paths 51 that open at the discharge ports 51a on the outer peripheral surface of the reduced diameter portion 37 that gradually narrows toward the second fastening portion 32, and sprayed toward the head 20. In this way, the fluid is supplied to, for example, the cutting location of the workpiece by the head 20. Note that the fluid supplied to the cutting location is not limited to coolant, and various lubricants and coolants can be used, and mist or air can also be supplied.

[0034] The supply flow path 52, which sends fluid to the discharge flow path 51, is composed of an axial flow path 61, a branch flow path 62, and an annular flow path 63. The axial flow path 61 is a flow path that runs from the rear end side of the main body 30 along the central axis Ax and is composed of engaging holes 40A and 40B that are hexagonal in front view. The axial flow path 61 is closed at the tip side of the main body 30 by the mounting portion 23 of the head 20 that is screwed into the fastening hole 35. In this way, the axial flow path 61 is a flow path that is hexagonal in front view and serves also as the engaging holes 40A and 40B, and is a flow path that is open at the rear end side of the main body 30 when the head 20 is fastened to the main body 30. The fluid is sent to the axial flow path 61 from the shank 10 to which the first fastening portion 31 of the main body 30 is fastened. In this way, in the joint part 100, the engagement holes 40A, 40B, which are hexagonal in front view and can be engaged with a hexagonal wrench, can also be used as the axial flow path 61 of the supply flow path 52 without forming a dedicated flow path.

[0035] As shown in Figures 7 to 9, the branch flow passages 62 are connected to the tip side of the axial flow passage 61. The branch flow passages 62 branch off from each vertex of the hexagonal axial flow passage 61, and the cross-sectional shape of each branch flow passage 62 gradually shortens in axial length and gradually increases in radial width toward the radial outward direction (see Figure 9). In this way, the main body 30 of the coupling part 100 has the same number of branch flow passages 62 as the number of vertices of the axial flow passage 61. In this example, since the hexagonal axial flow passage 61 has six vertices, six branch flow passages 62 are formed in the main body 30. In this way, in the coupling part 100, the branch flow passages 62 branch off from each vertex of the hexagonal axial flow passage 61. In other words, when the axial flow passage 61 is also used as the engagement holes 40A, 40B for engaging a hex wrench, the branch flow passage 62 branches off from a vertex that is not affected by fastening and unlocking with a hex wrench, so the inner wall surface 41 of the engagement hole 40A is not cut out by forming the branch flow passage 62. Therefore, by ensuring the contact area between the hex wrench and the inner wall surface 41, excessive stress on the engagement hole 40A is prevented. As a result, while providing the branch flow passage 62 branching off from the engagement hole 40A, damage to the engagement hole 40A can be prevented when the fitting part 100 is fastened to or unlocked from the shank 10 with a hex wrench.

[0036] The annular flow path 63 is provided between the branch flow paths 62 and the discharge flow paths 51 in the main body 30. This annular flow path 63 is formed in a ring shape around the circumferential direction of the main body 30, and six branch flow paths 62 and eight discharge flow paths 51 are connected to it. In this way, the branch flow paths 62 and the discharge flow paths 51 are connected to each other via the annular flow path 63, so that it is possible to reasonably provide a greater number of discharge flow paths 51 than the branch flow paths 62 without being affected by the number of branch flow paths 62, and to more effectively spray the fluid toward the cutting location by the head 20.

[0037] Furthermore, by providing an annular flow path 63 between the branch flow path 62 and the discharge flow path 51, the annular flow path 63 functions as a buffer. Therefore, the fluid can be efficiently sent from the annular flow path 63 to the discharge flow path 51 while suppressing pressure loss of the fluid sent from the branch flow path 62 to the annular flow path 63.

[0038] 10 , the discharge flow path 51 connected to the annular flow path 63 is initially inclined radially outward from the side communicating with the annular flow path 63 toward the tip of the main body 30 (see arrow D1 in FIG. 10 ), and is further inclined toward the central axis Ax of the main body 30 (see arrow D2 in FIG. 10 ), and opens at a discharge port 51 a on the outer circumferential surface of the reduced diameter portion 37. This allows the fluid discharged from the discharge port 51 a of the discharge flow path 51 to be more effectively sprayed toward the cutting location by the head 20.

[0039] Furthermore, each discharge flow path 51 is twisted in the same direction as the screwing direction R1 of the first fastening portion 31 into the shank 10 (see FIG. 5). Here, in a situation where the workpiece is rotated in the same direction as the screwing direction R1 of the first fastening portion 31 into the shank 10 during machining, if the discharge flow path 51 is twisted in the same direction as the screwing direction R1 of the first fastening portion 31 into the shank 10, the fluid is discharged from the discharge port 51 a of the discharge flow path 51 while being twisted in the rotation direction (see arrow V in FIG. 5). Therefore, the fluid discharged from the discharge port 51 a of the discharge flow path 51 can be more effectively sprayed toward the cutting location by the head 20.

[0040] 11, the discharge flow path 51 has a cross-sectional area S2 at the discharge port 51a that opens on the outer peripheral surface of the reduced diameter portion 37 that is smaller than the cross-sectional area S1 on the side communicating with the annular flow path 63. This allows the flow rate of the fluid sent from the annular flow path 63 to the discharge flow path 51 to be increased in the discharge flow path 51 and discharged from the discharge port 51a of the reduced diameter portion 37. This allows the fluid to be more effectively sprayed toward the cutting location by the head 20.

[0041] As described above, according to the joint component 100 of this embodiment, the fluid supplied to the supply flow path 52 is discharged from the plurality of discharge flow paths 51 that open at the discharge ports 51a on the outer peripheral surface of the tip side of the main body 30. Therefore, the fluid discharged from the discharge ports 51a of these discharge flow paths 51 can be effectively sprayed toward the vicinity of the cutting location by the head 20. This allows the fluid to be smoothly supplied to the cutting location of the workpiece by the head 20 for cooling and lubrication. Furthermore, the cutting width is not limited compared to a structure in which a separate member with a flow path is attached to the tip of the head.

[0042] In the above embodiment, the engagement holes 40A, 40B are hexagonal holes that can engage with the hexagonal wrench 60, but the engagement holes 40A, 40B may be polygonal holes other than hexagonal. Also, the engagement holes 40A, 40B are not limited to polygonal shapes and can be changed to holes with shapes that allow the insertion of various tools, such as Torx (registered trademark) holes.

[0043] REFERENCE SIGNS LIST 10 Shank (first fastened member) 20 Head (second fastened member) 30 Main body 31 First fastening portion 32 Second fastening portion 51 Discharge flow path 52 Supply flow path 61 Axial flow path 62 Branch flow path 63 Annular flow path 100 Joint part Ax Central axis S1, S2 Cross-sectional area

Claims

1. A coupling component having a main body having a first fastening portion at one end that can be fastened to a first fastened member and a second fastening portion at the other end that can be fastened to a second fastened member, the coupling component having a plurality of discharge flow paths that open at a plurality of circumferential positions on the outer peripheral surface of the other end of the main body, and supply flow paths that run from one end of the main body through a central axis and connect to the plurality of discharge flow paths.

2. The coupling part according to claim 1, wherein the discharge flow path opens at an angle toward the central axis toward the other end of the main body.

3. A joint component according to claim 1, wherein the discharge flow path is twisted in the same direction as the screwing direction of the first fastening portion into the first fastened member.

4. A joint component according to any one of claims 1 to 3, wherein the supply flow path has an axial flow path that passes through the central axis from one end side of the main body, and at least a portion of the axial flow path is formed in a non-circular shape when viewed from the front.

5. A joint component according to claim 4, wherein the axial flow path is formed in a polygonal shape when viewed from the front, and the supply flow path further has a plurality of branch flow paths branching off from each vertex of the polygon of the axial flow path and connecting to the discharge flow path.

6. A coupling part according to claim 5, wherein an annular flow path is formed between the branch flow path and the discharge flow path in the circumferential direction of the main body, and the branch flow path and the discharge flow path are connected to each other, and the number of discharge flow paths is greater than the number of branch flow paths.

7. A joint component according to claim 6, wherein the cross-sectional area of the discharge flow path on the opening side at the reduced diameter portion is smaller than the cross-sectional area of the side communicating with the annular flow path.

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