Holding member

Abstract

To provide a holding member that can enhance versatility and suppress cost increase and labor for replacement of a step.SOLUTION: A holding member extends along a tool shaft and a head member is attached to it at a tip in an axial direction along the tool shaft. The holding member includes a holding member body extending along the tool shaft. A mounting hole is provided in a tip face facing one side in the axial direction of the holding member body, the mounting hole being open on the tip face and extending toward a base end on the other side in the axial direction. The mounting hole has a tapered wall section having a reducing inner diameter as it goes from a tip side of the holding member body toward the base end side, a cylindrical wall section which has a constant inner diameter and extends in the axial direction, and a female screw section which is positioned on the base end side of the tapered wall section and the cylindrical wall section and is screwed to a male screw section of the head member.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a retaining member. [Background technology]

[0002] Among cutting tools used in machining workpieces are interchangeable-head tools in which a head member with a cutting blade is detachably attached to the tip of a tool holder. For example, Patent Document 1 discloses a configuration in which a mounting hole with a female thread is formed in the tool body, and a cutting blade member has a male thread formed on a cylindrical mounting shaft extending in the axial direction. Patent Document 2 discloses a configuration including a receiving member with a conical receiving hole and a connecting member with a mounting shaft having a centering stub. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 4636557 [Patent Document 2] Special Publication No. 4-48571 Summary of the Invention [Problem to be solved by the invention]

[0004] As disclosed in the above-mentioned Patent Documents 1 and 2, there are two types of head members: one with a cylindrical mounting shaft and one with a mounting shaft having a tapered shaft portion. When a single machine tool uses both a head member with a cylindrical mounting shaft and a head member with a mounting shaft having a tapered shaft portion, it is necessary to prepare both a tool holder with a mounting hole corresponding to the cylindrical mounting shaft and a tool holder with a tapered receiving hole corresponding to the tapered shaft portion. This increases the number of tool holders required, leading to increased costs. Furthermore, when replacing the head member, the tool holder also needs to be replaced, which can be time-consuming during setup.

[0005] In view of the above circumstances, one object of the present invention is to provide a holding member that is more versatile and can reduce increases in cost and the effort required for changeover. [Means for solving the problem]

[0006] (1) According to one aspect of the present invention, there is provided a holding member that extends along a tool shaft and has a head member detachably attached to its axial tip end along the tool shaft. The holding member has a holding member body that extends along the tool shaft, and a mounting hole in a tip end surface facing one axial side of the holding member body that opens at the tip end surface and extends toward a base end on the other axial side, into which a mounting shaft of the head member is inserted. The mounting hole has a tapered wall portion whose inner diameter decreases from the tip end to the base end of the holding member body, a cylindrical wall portion that has a constant inner diameter and extends in the axial direction, and a female thread portion that is located closer to the base end than the tapered wall portion and the cylindrical wall portion and that threads into a male thread portion of the mounting shaft of the head member.

[0007] According to one aspect of the retaining member of the present invention, the head member is attached to the retaining member body by inserting the mounting shaft into the mounting hole, threading the male threaded portion into the female threaded portion, and abutting a portion of the head member against the end face of the retaining member body. The mounting hole in the retaining member body has a tapered wall portion and a cylindrical wall portion. If the mounting shaft of the head member has a columnar shaft portion with a constant outer diameter, the columnar shaft portion is inserted radially inside the cylindrical wall portion, thereby positioning the mounting shaft radially within the mounting hole of the retaining member body. If the mounting shaft of the head member has a tapered shaft portion, the tapered shaft portion fits into the tapered wall portion, thereby preventing axial movement of the head member within the mounting hole of the retaining member body and positioning the mounting shaft radially. In this way, both head members having columnar shaft portions and head members having tapered shaft portions can be attached to a single retaining member. This eliminates the need to prepare a separate retaining member for each type of head member, thereby reducing costs. Furthermore, whether a head member having a columnar shaft portion or a head member having a tapered shaft portion is used, there is no need to replace the holding member, which reduces the effort required for changeover.

[0008] (2) In the holding member of (1), the tapered wall portion may be located closer to the tip of the holding member body than the cylindrical wall portion.

[0009] Because the tapered wall portion of the mounting hole is located closer to the tip than the cylindrical wall portion, when the mounting shaft of the head member is inserted into the mounting hole, the tapered wall portion can easily guide the mounting shaft radially inward of the cylindrical wall portion.

[0010] (3) In the holding member of (1) or (2), the tapered wall portion may have an axial length greater than the axial length of the cylindrical wall portion.

[0011] By making the axial length of the tapered wall portion greater than the axial length of the cylindrical wall portion, the tapered wall portion can more effectively perform its functions of positioning and guiding the mounting shaft.

[0012] (4) In any of the holding members (1) to (3), the mounting hole may further include an expanded wall portion located between the tapered wall portion, the cylindrical wall portion, and the female thread portion, and expanded radially outward from the tool axis.

[0013] The formation of the enlarged diameter wall portion between the tapered wall portion, the cylindrical wall portion, and the female thread portion prevents part of the mounting shaft of the head member from getting caught on the boundary between the tapered wall portion, the cylindrical wall portion, and the female thread portion, allowing the head member to be attached and detached smoothly.

[0014] (5) In the holding member according to any one of (1) to (4), the tapered wall portion may have an inclination angle θ of 1° or more and 10° or less with respect to the tool axis.

[0015] By setting the inclination angle θ of the tapered wall portion relative to the tool shaft to between 1° and 10°, the tapered wall portion can ensure the functions of positioning and guiding the mounting shaft while preventing the diameter of the mounting hole on the end face of the holding member from becoming too large. This prevents the contact area between the end face and the head member from becoming too small, allowing the head member to be stably held. [Effects of the Invention]

[0016] According to one aspect of the present invention, a holding member is provided that can suppress increases in costs and the effort required for changeover. [Brief explanation of the drawings]

[0017] [Figure 1] FIG. 1 is a cross-sectional view of a holding member according to an embodiment, taken along a tool axis. [Figure 2] FIG. 2 is an enlarged cross-sectional view showing a mounting hole of a holding member according to the embodiment. [Figure 3] FIG. 3 is a side view showing a head member having a columnar shaft portion attached to the holding member of the embodiment. [Figure 4] FIG. 4 is a cross-sectional view showing a state in which the head member of FIG. 3 is attached to the holding member of the embodiment. [Figure 5] FIG. 5 is a side view showing a head member having a tapered shaft portion that is attached to the holding member of the embodiment. [Figure 6] FIG. 6 is a cross-sectional view showing a state in which the head member of FIG. 5 is attached to the holding member of the embodiment. [Figure 7] FIG. 7 is an enlarged cross-sectional view showing a mounting hole of a holding member in a modified example. DETAILED DESCRIPTION OF THE INVENTION

[0018] A holding member 1, which is an example of a holding member according to one embodiment of the present invention, will be described below with reference to the drawings. Fig. 1 is a cross-sectional view of a holding member of an embodiment in a direction along the tool axis. Fig. 2 is an enlarged cross-sectional view showing a mounting hole of the holding member of an embodiment. Fig. 3 is a side view showing a head member having a columnar shaft portion that is attached to the holding member of an embodiment. Fig. 4 is a cross-sectional view showing the head member of Fig. 3 attached to the holding member of an embodiment. Fig. 5 is a side view showing a head member having a tapered shaft portion that is attached to the holding member of an embodiment. Fig. 6 is a cross-sectional view showing the head member of Fig. 5 attached to the holding member of an embodiment.

[0019] The holding member 1 of this embodiment is a cylindrical member centered on the tool axis J as shown in Fig. 1. A head member 100 can be detachably attached to the end of the holding member 1 on the tip F side as shown in Figs. 4, the first head member 100A includes a head main body 101 having a cutting blade (not shown), and a mounting shaft 102 having a male thread portion. A mounting hole 13 of the holding member 1 is provided with a female thread portion, and the mounting shaft 102 of the first head member 100A is inserted into the mounting hole 13, and the male thread portion of the mounting shaft 102 is tightened into the female thread portion of the mounting hole 13, thereby fixing the first head member 100A to the holding member 1.

[0020] In this specification, the direction in which the tool axis J extends may be simply referred to as the axial direction, the direction perpendicular to the tool axis J centered on the tool axis J may be simply referred to as the radial direction, and the circumferential direction centered on the tool axis J may be simply referred to as the circumferential direction.

[0021] As shown in Fig. 1, the holding member 1 includes a cylindrical holding member body 10 extending along the tool axis J. The holding member body 10 may be in the shape of a polygonal pillar. The holding member body 10 has an end face 11, a shank portion 12, and a mounting hole 13 opening in the end face 11.

[0022] The end face 11 of the holding member body 10 is located at the tip end on one axial side of the holding member body 10. In this embodiment, the one axial side of the holding member body 10 where the end face 11 having the mounting hole 13 is provided is the tip end F side of the holding member body 10, and the other axial side is the base end R side. The end face 11 faces the tip F and is a surface that extends in a direction perpendicular to the tool axis J. The shank portion 12 is the portion on the base end R side (the other axial side) of the holding member body 10. The holding member 1 is chucked and held by a machine tool at the shank portion 12.

[0023] The mounting holes 13 are configured so that mounting shafts 102, 112 (see FIGS. 3 to 6) of the head member 100, which will be described later, can be inserted into them. The mounting holes 13 are recessed from the end face 11 toward the base end R (the other axial side). The mounting holes 13 include multi-stage cylindrical holes and threaded holes centered on the tool axis J. 1 and 2, the mounting hole 13 includes a female thread portion 14, an expanded diameter wall portion 15, a cylindrical wall portion 16, and a tapered wall portion 17. The female thread portion 14, the expanded diameter wall portion 15, the cylindrical wall portion 16, and the tapered wall portion 17 are arranged in this order within the mounting hole 13 in the axial direction from the tip end F toward the base end R.

[0024] The female thread portion 14 is located axially closest to the base end R within the mounting hole 13. The female thread portion 14 has a helical female thread groove that screws into the male thread portion 103 of the head member 100, which will be described later. The expanded diameter wall portion 15 is disposed adjacent to the female thread portion 14 on the tip F side. The inner diameter d2 of the expanded diameter wall portion 15 is larger than the inner diameter d1 of the female thread portion 14 and the inner diameter d3 of the cylindrical wall portion 16. The expanded diameter wall portion 15 is expanded radially outward relative to the female thread portion 14 and the cylindrical wall portion 16, centered on the tool axis J. The expanded diameter wall portion 15 is cylindrical and extends in the axial direction with a constant inner diameter d2.

[0025] The cylindrical wall portion 16 is disposed adjacent to the expanded diameter wall portion 15 on the side of the tip F. The cylindrical wall portion 16 is cylindrical and extends in the axial direction with a constant inner diameter d3. The inner diameter d3 of the cylindrical wall portion 16 is slightly larger than the outer diameter D11 of a columnar shaft portion 105 (see Figures 3 and 4) of the head member 100, which will be described later.

[0026] The tapered wall portion 17 is disposed adjacent to the cylindrical wall portion 16 on the side of the tip F. The tapered wall portion 17 has a tapered shape (circumferential wall shape of a truncated cone) in which the inner diameter decreases from the tip F toward the base end R. The end portion of the tapered wall portion 17 on the base end R side is connected to the end portion of the cylindrical wall portion 16 on the tip F side.

[0027] 2, the inclination angle θ of the tapered wall portion 17 relative to the direction extending parallel to the tool axis J is preferably in the range of 1°≦θ≦10°. If the inclination angle θ is less than 1°, it becomes difficult to ensure that the tapered wall portion 17 can position and guide the mounting shaft. On the other hand, if the inclination angle θ exceeds 10°, the diameter of the mounting hole 13 on the end face 11 of the holding member 1 becomes large, and the contact area of the end face 11 with the head member becomes small, making it difficult to stably hold the head member 100.

[0028] A more preferable range of the inclination angle θ is 2°≦θ≦5°, and an especially preferable range of the inclination angle θ is 2.5°≦θ≦3.5°. When θ is 2.5° or more, it becomes easier to ensure processing precision at a mass production level when forming mounting hole 13. Furthermore, when θ is 3.5° or less, it is possible to ensure sufficient thickness of holding member 1 around mounting hole 13, and a decrease in the rigidity of holding member 1 can be suppressed.

[0029] 2 is preferably greater than the axial length L2 of the cylindrical wall portion 16. This allows the tapered wall portion 17 to more effectively perform its functions of positioning and guiding the mounting shaft of the head member 100.

[0030] Additionally, a chamfered portion 18 is formed adjacent to the tip F of the tapered wall portion 17. That is, the chamfered portion 18 is provided on the periphery of the mounting hole 13 that opens into the end face 11. In the holding member 1, the chamfered portion 18 does not come into contact with the outer peripheral surface of the mounting shaft 102 of the head member 100, and does not function as the tapered wall portion 17. The chamfered portion 18 does not correspond to the tapered wall portion 17 of this embodiment.

[0031] As shown in FIG. 1, a through hole 19 is formed in the holding member body 10. The through hole 19 opens to a bottom surface 13d located at the end of the mounting hole 13 on the base end R side and to an end surface 10e on the base end R side of the holding member body 10, and penetrates the holding member body 10 in the axial direction between the bottom surface 13d and the end surface 10e. The through hole 19 can be used as a coolant supply port. The holding member body 10 may also be configured without the through hole 19.

[0032] As shown in Figures 3 to 6, the head member 100 is configured to be detachable from the holding member 1. The head member 100 is used for cutting processes such as end milling, drilling, and reaming. In this embodiment, a first head member 100A shown in Figures 3 and 4 and a second head member 100B shown in Figures 5 and 6 are exemplified as head members 100 detachable from the holding member 1. In the description of the head member 100, the side on which the cutting blade of the head member 100 is arranged in the direction along the tool axis C of the head member 100 will be referred to as the tip end F side, and the side opposite to the side on which the cutting blade is arranged will be referred to as the base end R side.

[0033] The first head member 100A shown in Figures 3 and 4 integrally includes a head body 101 having a cutting blade (not shown) and a mounting shaft 102. The head body 101 and the mounting shaft 102 are each roughly cylindrical and centered on the tool axis C. Note that the head body 101 is illustrated as having a general appearance that is cylindrical and centered on the tool axis C, but the specific shape will vary depending on the function required of the head body 101.

[0034] The head body 101 has a cutting edge (not shown) on the tip F side (one axial side) shown in FIG. 3. The head body 101 has a seating surface 101s facing the base R side (the other axial side). The mounting shaft 102 protrudes from the center of the seating surface 101s of the head body 101 toward the base R side. The mounting shaft 102 has a smaller diameter than the head body 101, and the seating surface 101s of the head body 101 extends in an annular shape around the mounting shaft 102.

[0035] The mounting shaft 102 has a male thread portion 103 , a small diameter portion 104 , and a columnar shaft portion 105 . The male thread portion 103 is located at the tip end on the base end R side of the mounting shaft 102. The male thread portion 103 has a helical male thread groove that screws into the female thread portion 14 of the mounting hole 13 of the holding member 1.

[0036] The small diameter portion 104 is disposed adjacent to the tip F side (head body 101 side) of the male thread portion 103. The small diameter portion 104 has a cylindrical shape with a narrowed center in the direction along the tool axis C. The small diameter portion 104 has the same diameter as the male thread portion 103 and the columnar shank 105 at the connection portions with the male thread portion 103 and the columnar shank 105, respectively. The diameter of the small diameter portion 104 becomes smaller from both ends in the direction along the tool axis C toward the center.

[0037] The columnar shank 105 is disposed adjacent to the small diameter portion 104 on the tip F side (head body 101 side). The columnar shank 105 has a constant outer diameter D11 and is cylindrical with its center on the tool axis C. The columnar shank 105 is tapered near the connection between the columnar shank 105 and the head body 101 toward the tip F. The columnar shank 105 may not have the tapered portion.

[0038] 4, to mount the first head member 100A on the holding member 1, the mounting shaft 102 of the first head member 100A is inserted into the mounting hole 13 of the holding member 1, the male thread portion 103 is engaged with the female thread portion 14, and the mounting shaft 102 is tightened until the seating surface 101s of the head body 101 abuts against the end surface 11 of the holding member 1. With the first head member 100A mounted on the holding member 1, the columnar shaft portion 105 is inserted radially inside the cylindrical wall portion 16, and the inner peripheral surface of the cylindrical wall portion 16 and the outer peripheral surface of the columnar shaft portion 105 are in surface contact. This restricts radial movement of the columnar shaft portion 105 (mounting shaft 102).

[0039] Next, as shown in FIGS. 5 and 6, the second head member 100B integrally includes a head main body 111 having a cutting blade (not shown) and a mounting shaft 112. The head main body 111 is provided with a cutting blade (not shown) on the tip F side (one axial side). The head main body 111 has a seating surface 111s facing the base R side (the other axial side). The mounting shaft 112 protrudes from the center of the seating surface 111s of the head main body 111 toward the base R side. The mounting shaft 112 has a smaller diameter than the head main body 111, and the seating surface 111s of the head main body 111 extends in an annular shape around the mounting shaft 112.

[0040] The mounting shaft 112 has a male thread portion 113 , a small diameter portion 114 , and a tapered shaft portion 115 . The male thread portion 113 is located at the tip end on the base end R side of the mounting shaft 112. The male thread portion 113 has a helical male thread groove that screws into the female thread portion 14 of the mounting hole 13 of the holding member 1.

[0041] The small diameter portion 114 is disposed adjacent to the tip F side (head body 111 side) of the male thread portion 113. The small diameter portion 114 has a cylindrical shape with a narrowed center in the direction along the tool axis C. The small diameter portion 114 has the same diameter as the male thread portion 113 and the tapered shaft portion 115 at the connection portions with the male thread portion 113 and the tapered shaft portion 115, respectively. The diameter of the small diameter portion 114 becomes smaller from both ends in the direction along the tool axis C toward the center.

[0042] The tapered shank 115 is disposed adjacent to the small diameter portion 114 on the tip F side (head body 111 side). As shown in FIG. 5, the tapered shank 115 is tapered (frusto-conical) in that the outer diameter D12 gradually decreases from the tip F toward the base R. It is preferable that the inclination angle α of the outer peripheral surface of the tapered shank 115 relative to the central axis (tool axis C) of the mounting shaft 112 is slightly larger than the inclination angle θ of the tapered wall portion 17. It is preferable that the angle difference (α-θ) between the inclination angle α and the inclination angle θ is in the range of 0.1°≦(α-θ)≦0.9°, for example.

[0043] 6, to attach the second head member 100B to the holding member 1, the mounting shaft 112 of the second head member 100B is inserted into the mounting hole 13 of the holding member 1, the male thread portion 113 is engaged with the female thread portion 14, and the head body 111 is tightened until the seating surface 111s of the head body 111 abuts against the end face 11 of the holding member 1. The tapered shaft portion 115 is inserted radially inside the tapered wall portion 17 with the seating surface 111s abutting against the end face 11, and the inner peripheral surface of the tapered wall portion 17 and the outer peripheral surface of the tapered shaft portion 115 are in surface contact. This prevents the tapered shaft portion 115 (mounting shaft 112) from moving toward the base end R and positions it radially.

[0044] According to the holding member 1 of the present embodiment described above, both the first head member 100A and the second head member 100B can be attached to the holding member main body 10. When the first head member 100A is attached, the mounting hole 13 of the holding member main body 10 holds the columnar shaft portion 105 of the mounting shaft 102 of the first head member 100A from the radially outer side by the cylindrical wall portion 16. When the second head member 100B is attached, the mounting hole 13 holds the tapered shaft portion 115 of the mounting shaft 112 of the second head member 100B from the radially outer side by the tapered wall portion 17. In this way, both the first head member 100A having the columnar shaft portion 105 and the second head member 100B having the tapered shaft portion 115 can be attached to one holding member 1. This eliminates the need to prepare a holding member 1 for each type of head member 100, thereby preventing costs from increasing. Furthermore, even when exchanging the first head member 100A having the columnar shaft portion 105 with the second head member 100B having the tapered shaft portion 115, it is only necessary to exchange the head member 100 without exchanging the holding member 1. This reduces the effort required for changeover.

[0045] In this embodiment, the tapered wall portion 17 of the holding member 1 is disposed on the tip F side of the cylindrical wall portion 16. As a result, when the mounting shafts 102, 112 of the head member 100 are inserted into the mounting hole 13, the tapered wall portion 17 can easily guide the mounting shafts 102, 112 radially inward of the cylindrical wall portion 16.

[0046] In this embodiment, the axial length L1 of the tapered wall portion 17 is greater than the axial length L2 of the cylindrical wall portion 16. This allows the tapered wall portion 17 to more effectively perform its functions of positioning the mounting shaft 112 and guiding the mounting shafts 102, 112.

[0047] In this embodiment, an expanded diameter wall portion 15 is formed between the tapered wall portion 17 and the cylindrical wall portion 16 and the female thread portion 14. This prevents parts of the mounting shafts 102 and 112 of the head member 100 from getting caught on the boundary between the tapered wall portion 17 and the cylindrical wall portion 16 and the female thread portion 14, thereby increasing the durability of the holding member 1.

[0048] Furthermore, in this embodiment, if the inclination angle θ of the tapered wall portion 17 with respect to the tool axis J is set in the range of 1° to 10°, it is possible to prevent the opening diameter dimension of the mounting hole 13 on the end surface 11 of the holding member 1 from becoming large while ensuring the functions of the tapered wall portion 17, such as positioning the mounting shaft 112 and guiding the mounting shafts 102, 112. This makes it easier to ensure the contact area between the holding member 1 and the head member 100 on the end surface 11 of the holding member 1, making it easier to stably hold the head member 100.

[0049] The present invention is not limited to the above-described embodiment, and the configuration can be changed within the scope of the present invention, as will be described below.

[0050] FIG. 7 shows a modification of the holding member described in the above embodiment. In the above embodiment, the tapered wall portion 17 is disposed on the tip end F side (one axial side) of the cylindrical wall portion 16. In contrast, in the holding member 1B of the modified example, the tapered wall portion 17B is disposed on the base end R (the other axial side) of the cylindrical wall portion 16B in the mounting hole 13B of the holding member 1B. The holding member 1B has a step surface 21 between the tapered wall portion 17B and the cylindrical wall portion 16B. The provision of the step surface 21 makes it possible to avoid interference between the tapered shaft portion 115 and the cylindrical wall portion 16B when the tapered shaft portion 115 of the second head member 100B is brought into contact with the tapered wall portion 17B.

[0051] In the above-described embodiment and modified example, the holding members 1 and 1B are shank members that hold the head member 100, but this is not limiting. The holding members 1 and 1B may also be vibration-isolating arbors equipped with a vibration-isolating mechanism.

[0052] Furthermore, the configurations (elements) described in the above-described embodiments, modifications, and notes may be combined without departing from the spirit of the present invention, and additions, omissions, substitutions, and other modifications of the configurations are possible. Furthermore, the present invention is not limited to the above-described embodiments, but is limited only by the claims. [Explanation of symbols]

[0053] 1...Holding member 10...Holding member body 11...End face 13...Mounting hole 14...Female thread 15...Expanded wall section 16...Cylindrical wall 17...Tapered wall 100...Head member 100A...First head member 100B...Second head member 102, 112...Mounting shaft 103, 113... Male thread 105...Column shaft part 115...Tapered shaft J…Tool axis θ,α…Inclination angle

Claims

1. A holding member that extends along a tool shaft and has a head member detachably attached to a tip end portion in an axial direction along the tool shaft, a holding member body extending along the tool axis; a mounting hole, which opens on a tip end surface of the holding member body facing one axial side and extends toward a base end on the other axial side, into which a mounting shaft of the head member is inserted; The mounting holes are a tapered wall portion whose inner diameter decreases from the distal end side to the proximal end side of the holding member body; a cylindrical wall portion having a constant inner diameter and extending in an axial direction; a female thread portion located closer to the base end than the tapered wall portion and the cylindrical wall portion, the female thread portion being threadedly engaged with the male thread portion of the mounting shaft of the head member; having Holding member.

2. the tapered wall portion is located closer to the tip end of the holding member body than the cylindrical wall portion; The retaining member according to claim 1 .

3. The axial length of the tapered wall portion is greater than the axial length of the cylindrical wall portion. The holding member according to claim 1 or 2.

4. The mounting holes are the tool further includes an expanded diameter wall portion located between the tapered wall portion, the cylindrical wall portion, and the female thread portion, and the expanded diameter wall portion is expanded radially outward from the tool axis. The holding member according to claim 1 or 2.

5. the tapered wall portion has an inclination angle θ with respect to the tool axis of 1° or more and 10° or less; The holding member according to claim 1 or 2.

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