Joint component

Abstract

Provided is a joint component capable of easily fastening to and unfastening from a fastened member while maintaining high rigidity.　A joint component 100 includes a first fastening part 31 and a second fastening part 32 that can be screwed into a shank 10 and a head 20, the joint component 100 being capable of fastening and unfastening the first fastening part 31 and the second fastening part 32 with respect to the shank 10 and the head 20 by rotating around a central axis Ax due to a hexagonal wrench 60, wherein an engagement hole 40A having a non-circular shape in front view, with which the hexagonal wrench 60 can be engaged around the central axis Ax, is formed in parallel with the central axis Ax on a distal-end side, which is at least one end in the center-axis Ax direction.

Description

Joint parts

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

[0002] In a cutting head that is removably fixed to a holder, it is disclosed that the outer surface of the sleeve to which the cutting blade is fixed is provided with parallel flat surfaces that function as engagement surfaces for an open-end wrench when fastening and unfastening the holder (see, for example, Patent Documents 1 and 2).

[0003] Patent Publication No. 2021-504159 U.S. Patent Application Publication No. 2008 / 0304923

[0004] However, as described above, providing parallel flat surfaces on the outer surface of the sleeve that function as engagement surfaces for the open-end wrench may result in a decrease in the rigidity of the sleeve, which may affect cutting by the cutting head.

[0005] The present invention has been made in consideration of the above circumstances, and aims to provide a joint component that can be easily fastened to and unfastened from fastened members while maintaining high rigidity.

[0006] A joint component according to one aspect of the present invention has a fastening portion that can be screwed into fastened members, and the fastening portion can be fastened and unclamped to the fastened members by rotating it around a central axis with a power tool such as a wrench. At least one end of the joint component in the direction of the central axis has an engagement hole that is non-circular in front view and parallel to the central axis, with which the power tool can engage around the central axis.

[0007] In a joint component having the above structure, fastening and unfastening can be easily performed on the workpieces by rotating a power tool such as a wrench inserted into the engagement hole. Moreover, since the engagement hole, which is non-circular in front view and for engaging the power tool, is formed parallel to the central axis, a decrease in rigidity is suppressed compared to when an engagement surface for engaging the power tool is formed on the outer circumferential surface. In other words, fastening and unfastening can be easily performed on the workpieces while maintaining high rigidity.

[0008] The engagement hole may be formed in a polygonal shape when viewed from the front, and the inner wall surface of the engagement hole may be formed in a convex arc shape that bulges out in an arc shape toward the central axis when viewed from the front.

[0009] The engagement hole may be hexagonal in front view.

[0010] The inner wall surface of the engagement hole may be inclined in a direction gradually approaching the central axis in the depth direction.

[0011] The depth of the engagement hole may be greater than the diameter of the inscribed circle of the engagement hole.

[0012] Engagement holes may be formed on both ends in the central axis direction.

[0013] The engagement hole on one end may have a greater depth than the engagement hole on the other end.

[0014] It may have a first fastening portion at one end with a male thread that can be fastened to the female thread of a first fastened member, and a second fastening portion at the other end with a female thread that can be fastened to the male thread of a second fastened member, and the circumscribed circle of the engagement hole may be smaller in diameter than the male thread of the first fastening portion and the female thread of the second fastening portion.

[0015] According to the present invention, a joint component is provided that can be easily fastened to and unfastened from fastened members while maintaining high rigidity.

[0016] 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 tip end side. FIG. 4 is a front view of the joint part as viewed from the rear end side. FIG. 5 is a cross-sectional view along the central axis of the joint part. FIG. 6 is a perspective view illustrating how to fasten and release the joint part to the shank. FIG. 7 is a perspective view illustrating how to fasten and release the joint part to the head. FIG. 8 is a front view of an engagement hole formed in the joint part. FIG. 9 is an explanatory view showing the state when a hexagonal wrench inserted into the engagement hole is rotated. FIG. 10 is an explanatory view showing the shape of the engagement hole in the depth direction.

[0017]

[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.

[0018] 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.

[0019] 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.

[0020] The joint component 100 has a main body 30 formed in a generally cylindrical shape as a whole. The joint component 100 has a first fastening portion 31 at one end, i.e., the rear end, of the main body 30. The joint component 100 also has a second fastening portion 32 at the other end, i.e., the front end, of the main body 30.

[0021] 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.

[0022] 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.

[0023] 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.

[0024] 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.

[0025] 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.

[0026] 3 to 5, 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, with the engagement hole 40A on the leading 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.

[0027] These engagement holes 40A, 40B are tool holes into which a wrench (power tool) 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 each have a non-circular shape when viewed from the front. In this example, the engagement holes 40A, 40B each have a hexagonal shape when viewed from the front, allowing a hexagonal wrench to be inserted and removed. By inserting a hexagonal wrench into the engagement holes 40A, 40B, the hexagonal wrench can be engaged around the central axis Ax of the main body 30.

[0028] 6, when fastening or releasing the first fastening portion 31 of the coupling part 100 to the mounting hole 12 of the shank 10, the actuating rod 61 of the hexagonal wrench 60 is inserted into the engagement hole 40A from the tip side of the main body 30. Then, by gripping the operating rod 62 of the hexagonal wrench 60 and rotating the hexagonal wrench 60 in either direction while fixing the shank 10, the coupling part 100 to the shank 10 is fastened or released.

[0029] Furthermore, the attachment portion 23 of the head 20 is fastened and unfastened to the second fastening portion 32 of the coupling component 100, which is fixed to the shank 10. In this way, the head 20 is usually fastened and unfastened to the coupling component 100, which is fastened and fixed to the shank 10. However, when the head 20 is rotated to remove the head 20 from the coupling component 100, the coupling component 100 may loosen and come off from the shank 10 along with the head 20. In such a case, as shown in Figure 7, the head 20 can be removed from the coupling component 100 by inserting the actuating rod portion 61 of a hexagonal wrench 60 into the engagement hole 40B of the coupling component 100 and rotating the head 20 while holding the hexagonal wrench 60 in place to prevent the coupling component 100 from rotating.

[0030] In this way, the joint part 100 has engagement holes 40A, 40B formed on both ends of the main body 30, so that the hex wrench 60 can be inserted into either end and rotated around the central axis Ax.

[0031] As shown in Figure 8, the engagement holes 40A, 40B formed in the main body 30 of the joint part 100 have six inner wall surfaces 41. In addition, relief recesses 42 are provided between adjacent inner wall surfaces 41, which are the vertices of the hexagon, to reduce interference with the edge portion 60a of the hexagonal wrench 60 and allow smooth insertion and removal. In the engagement holes 40A, 40B, the inner wall surfaces 41 that come into contact with the hexagonal wrench 60 are formed in a convex arc shape that bulges out toward the central axis Ax in a front view. The convex arc-shaped inner wall surfaces 41 have an arc that is larger than the diameter of the inscribed circle C of the engagement holes 40A, 40B.

[0032] Here, if the inner wall surface 41 of the engagement holes 40A, 40B is straight when viewed from the front, when tightening with the hex wrench 60, the edge portion 60a of the hex wrench 60 may come into contact with the inner wall surface 41 of the engagement holes 40A, 40B, causing the edge portion 60a of the hex wrench 60 or the inner wall surface 41 of the engagement holes 40A, 40B to become concave.

[0033] 9, when viewed from the front, if the inner wall surface 41 of the engagement holes 40A, 40B, which is the contact portion with the hexagonal wrench 60, is formed in a convex arc shape, it is possible to reduce the contact angle θ between the hexagonal wrench 60 and the inner wall surface 41. As a result, the contact area between the inner wall surface 41 and the hexagonal wrench 60 is increased at the contact portion with the hexagonal wrench 60, thereby alleviating stress and suppressing deformation such as dents in the edge portion 60a or the inner wall surface 41.

[0034] In particular, since the convex arc shape of the inner wall surface 41 is an arc larger than the diameter of the inscribed circle C of the engagement holes 40A, 40B, the contact angle θ between the inner wall surface 41 of the engagement holes 40A, 40B and the hexagonal wrench 60 when the hexagonal wrench 60 inserted into the engagement holes 40A, 40B is turned can be made smaller. This allows the contact points between the inner wall surface 41 of the engagement holes 40A, 40B and the hexagonal wrench 60 to be closer to surface contact.

[0035] As shown in FIG. 10 , the inner wall surfaces 41 of the engagement holes 40A and 40B are inclined in a direction gradually approaching the central axis Ax in the depth direction. Because the inner wall surfaces 41 of the engagement holes 40A and 40B are inclined in a direction gradually approaching the central axis Ax in the depth direction, the hex wrench 60 can be easily inserted into the engagement holes 40A and 40B. Furthermore, the more the hex wrench 60 is inserted into the engagement holes 40A and 40B, the more parallel the hex wrench 60 becomes to the central axis Ax, thereby increasing the contact area with the inner wall surfaces 41 of the engagement holes 40A and 40B. Furthermore, the depths Da and Db of the engagement holes 40A and 40B are greater than the diameter of the inscribed circle C of the engagement holes 40A and 40B. This ensures a sufficient contact area between the hex wrench 60 and the inner wall surfaces 41 of the engagement holes 40A and 40B. In this example, the depth Da of the engagement hole 40A is the dimension from the end of the engagement hole 40A on the second fastening portion 32 side to the end of the engagement hole 40B side (boundary 45). The depth Db of the engagement hole 40B is the dimension from the end of the engagement hole 40B on the rear end side of the joint part 100 to the end of the engagement hole 40A on the engagement hole 40A side (boundary 45).

[0036] Furthermore, in the main body 30 of the joint part 100, the depth Da of the engagement hole 40A on the tip side is made larger than the depth Db of the engagement hole 40B on the rear side. This engagement hole 40A on the tip side is a hole that is mainly used as a tool hole into which a hexagonal wrench 60 is inserted and rotated when fastening and unlocking the joint part 100 to the shank 10. In other words, the depth Da of the engagement hole 40A that is mainly used is made larger than the engagement hole 40B that is used to remove the head 20 from the joint part 100 in the unlikely event that the joint part 100 and the head 20 become loose and come off from the shank 10, thereby ensuring a large contact area of ​​the hexagonal wrench 60 with the inner wall surface 41 of the engagement hole 40A.

[0037] As described above, with the joint part 100 according to this embodiment, the shank 10 can be easily fastened and unfastened by rotating the hex wrench 60 inserted into the engagement hole 40A. Similarly, the head 20 can be easily fastened and unfastened by rotating the hex wrench 60 inserted into the engagement hole 40B. Moreover, because the engagement hole 40A for engaging the hex wrench 60 is formed parallel to the central axis Ax, a decrease in rigidity is suppressed compared to when an engagement surface for engaging an open-end wrench is formed on the outer circumferential surface. In other words, high rigidity can be maintained while easily fastening and unfastening the shank 10 or head 20, which are the members to be fastened.

[0038] 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.

[0039] In the above embodiment, the engagement holes 40A, 40B are provided at both ends of the main body 30 of the joint part 100, but either of the engagement holes 40A or 40B may be provided. When either of the engagement holes 40A or 40B is provided, it is preferable to provide the engagement hole 40A, which is mainly used as a tool hole for fastening to and releasing from the shank 10.

[0040] REFERENCE SIGNS LIST 10 Shank (first fastened member) 11 Internal thread 20 Head (second fastened member) 22 External thread 31 First fastening portion 32 Second fastening portion 33 External thread 36 Internal thread 40A, 40B Engagement hole 41 Inner wall surface 60 Hexagonal wrench (work tool) 100 Joint part Ax Central axis C Inscribed circle Da, Db Depth

Claims

1. A coupling part having a fastening part that can be screwed into fastened members, and that can be fastened and unclamped to the fastened members by rotating the fastening part around a central axis with a power tool, wherein an engagement hole that is non-circular in front view and that can be engaged with the power tool around the central axis is formed parallel to the central axis at least on one end side in the central axis direction.

2. A joint component as set forth in claim 1, wherein the engagement hole is formed in a polygonal shape when viewed from the front, and the inner wall surface of the engagement hole is formed in a convex arc shape that bulges out in an arc toward the central axis when viewed from the front.

3. A joint component according to claim 2, wherein the engagement hole is hexagonal in front view.

4. A joint component as set forth in claim 1, wherein the inner wall surface of the engagement hole is inclined in a direction gradually approaching the central axis in the depth direction.

5. The fastening component according to claim 1, wherein the depth of the engagement hole is greater than the diameter of the inscribed circle of the engagement hole.

6. A joint part according to claim 1, wherein the engagement holes are formed on both ends in the direction of the central axis.

7. A joint part according to claim 6, wherein the engagement hole on one end side has a greater depth than the engagement hole on the other end side.

8. A joint component as claimed in any one of claims 1 to 7, having a first fastening part at one end provided with a male thread capable of being fastened to a female thread of a first fastened member, and a second fastening part at the other end provided with a female thread capable of being fastened to a male thread of a second fastened member, wherein the circumscribed circle of the engagement hole has a smaller diameter than the diameter of the male thread of the first fastening part and the female thread of the second fastening part.

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