Double-headed tool, double-headed tool jig, and double-headed tool manufacturing

Abstract

To provide a jig for a double-headed tool capable of uniformly applying coating to both blade parts of the double-headed tool by one coating treatment.SOLUTION: A double-headed tool jig 10 includes a cylindrical jig body 11 into which a double-headed tool 20 having a first blade portion 22 and a second blade portion 23 at both ends of a columnar intermediate portion 21 can be inserted, and a locking portion 14 provided on the jig body 11 so as to be locked to a locking surface of the double-headed tool 20 such that each of the first blade portion 22 and the second blade portion 23 of the double-headed tool 20 inserted from one opening end of the jig body 11 projects uniformly from the one opening end or the other opening end.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a double-headed tool, a jig for a double-headed tool, and a method for manufacturing a double-headed tool. [Background technology]

[0002] Coating treatments are performed on the cutting edges of tools such as end mills and center hole drills to improve wear resistance, heat resistance, lubricity, etc. (See Patent Document 1). The coating treatment in Patent Document 1 involves placing the tools held by a jig in a chamber and applying a physical vapor deposition method such as ion plating. The jig has a circular rotating plate and multiple cylindrical holders capable of receiving the shanks of the tools. The multiple holders are arranged at equal intervals on the upper surface of the rotating plate around the rotation axis of the rotating plate. The jig can hold multiple tools with the cutting edges of the tools facing vertically upward and exposed. Rotating the jig during the coating treatment allows the coating treatment to be performed uniformly on the cutting edges of each of the multiple tools. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2003-301269 Summary of the Invention [Problem to be solved by the invention]

[0004] Incidentally, double-edged tools, such as end mills and center hole drills, which have cutting edges at both ends of the tool, are known. When coating both cutting edges of a double-edged tool using the jig described in Patent Document 1, the coating is performed on one cutting edge of the double-edged tool. Next, the jig and double-edged tool are removed from the chamber, and the tool is placed relative to the jig so that the other cutting edge of the double-edged tool is exposed. Next, the jig and double-edged tool are placed back into the chamber, and the coating is performed.

[0005] It is difficult to make all conditions completely identical for the two separate coating processes, one for one cutting edge and the other for the other, and the condition and thickness of the coating on each cutting edge may differ to some extent. Furthermore, after coating one cutting edge, problems with the coating equipment may prevent the other cutting edge from being coated immediately. In this case, the coating on one cutting edge must be removed, which takes extra time.

[0006] The present invention aims to provide a jig for a double-headed tool that can apply a uniform coating to both cutting edges of the double-headed tool in a single coating process. It also aims to provide a method for manufacturing a double-headed tool using the jig for a double-headed tool, and a double-headed tool manufactured using the method. [Means for solving the problem]

[0007] According to one aspect of the present invention, there is provided a jig for a double-headed tool, characterized in that it comprises a cylindrical jig body into which a double-headed tool having cutting edges at both ends of a columnar middle section can be inserted, and a locking portion provided on the jig body to lock with a locking surface of the double-headed tool so that each of the cutting edges of the double-headed tool inserted from one open end of the jig body protrudes evenly from the one open end or the other open end.

[0008] It is preferable that the locking surface is the surface of a groove provided in the blade portion, and that the locking portion is a protrusion protruding radially inward. It is preferable that the locking portion has at least two protrusions, and that the at least two protrusions are arranged at symmetrical positions around the central axis. It is preferable that the jig further includes a circular rotating plate having a plurality of insertion holes provided at equal intervals on a circumference centered on the rotation axis, and that the plurality of jig bodies are configured to be inserted into the plurality of insertion holes so that the central axis of each of the plurality of jig bodies is parallel to the rotation axis of the rotating plate.

[0009] According to another aspect of the present invention, there is provided a method for manufacturing a double-headed tool, comprising the steps of: inserting a double-headed tool having cutting edges at both ends of a columnar intermediate section from one open end of a cylindrical jig body; engaging surfaces of grooves provided in the cutting edges with locking portions provided on the jig body so that each of the cutting edges of the double-headed tool inserted into the jig body protrudes evenly from one open end or the other open end; coating the cutting edges of the double-headed tool inserted into the jig body; and obtaining the double-headed tool in which the cutting edges have been coated except for the areas where they have been engaged with the locking portions.

[0010] According to yet another aspect of the present invention, there is provided a double-ended tool having a first cutting edge portion and a second cutting edge portion at each end of a cylindrical intermediate section, wherein the first cutting edge portion and the second cutting edge portion excluding the intermediate section are coated, and at least a portion of the first cutting edge portion is provided with an identification area where no coating is applied. [Effects of the Invention]

[0011] According to the aspects of the present invention, there is provided a jig for a double-headed tool that can apply a uniform coating to both cutting edges of the double-headed tool in a single coating process, and there is also provided a method for manufacturing a double-headed tool using the jig for a double-headed tool, and a double-headed tool manufactured using the method. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 1 is a perspective view of a double-headed tool jig according to an embodiment of the present invention in use. [Figure 2] 2 is a partial vertical cross-sectional view of the double-headed tool jig of FIG. [Figure 3] FIG. 3 is a perspective view of a double-headed tool jig. [Figure 4] FIG. 4 is a partial vertical cross-sectional view of a jig for a double-headed tool and the double-headed tool. [Figure 5]FIG. 5 is another partial vertical cross-sectional view of the double-headed tool jig and the double-headed tool. [Figure 6] FIG. 6 is a side view of the double-ended tool after the coating process. DETAILED DESCRIPTION OF THE INVENTION

[0013] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. Corresponding components throughout the drawings are designated by common reference numerals.

[0014] Fig. 1 is a perspective view of a double-headed tool jig 10 according to an embodiment of the present invention in use, and Fig. 2 is a partial vertical cross-sectional view of the double-headed tool jig 10 of Fig. 1. Fig. 3 is a perspective view of the double-headed tool jig 10. Fig. 4 is a partial vertical cross-sectional view of the double-headed tool jig 10 and a double-headed tool 20, and Fig. 5 is another partial vertical cross-sectional view of the double-headed tool jig 10 and a double-headed tool 20.

[0015] FIG. 1 shows twelve double-headed tool jigs 10, twelve double-headed tools 20, and one circular rotating plate 30. Each of the twelve double-headed tools 20 is held by a corresponding double-headed tool jig 10. The twelve double-headed tool jigs 10 holding the double-headed tools 20 are attached to the rotating plate 30. In FIGS. 1 to 5, the bottom is vertically downward and the top is vertically upward. In the state of use, i.e., during preparation for or during the coating process, each of the double-headed tools 20 is positioned so that the central axis of the double-headed tool 20 is parallel to the vertical direction. In the following description of each component, for convenience, the "upper" and "lower" sides are defined according to the position in the state of use.

[0016] 3 in particular, the double-ended tool jig 10 has a cylindrical jig body 11 and a larger-diameter engagement portion 12 provided on the upper part of the jig body 11. The outer peripheral surface of the engagement portion 12 is provided with six recesses 12a extending in the axial direction and equally spaced along the circumferential direction. The lower end surface of the engagement portion 12 is provided with an annular fitting groove 13 so as to surround the jig body 11. The lower end surface of the jig body 11 is provided with two locking portions 14, which are protrusions. The two locking portions 14 are arranged symmetrically around the central axis of the double-ended tool jig 10. The two locking portions 14 are provided at the lower open end of the jig body 11 so as to protrude radially inward.

[0017] The double-ended tool 20 is a so-called double-edged center hole drill having cutting edges at both ends. In addition to a center hole drill, the double-ended tool 20 may be an end mill or other double-ended tool. The double-ended tool 20 has a columnar middle portion 21, a first cutting edge portion 22 provided at the lower end of the middle portion 21, and a second cutting edge portion 23 provided at the upper end of the middle portion 21. The first cutting edge portion 22 has two spiral grooves 24. The second cutting edge portion 23 has two spiral grooves 25. In other words, the double-ended tool 20 is a two-blade tool, but may also be a four- or six-blade tool.

[0018] The circular rotating plate 30 is configured to be rotatable about a central axis C1 whose axis is the center of the rotating plate 30. In other words, the central axis C1 is the axis of rotation. The rotating plate 30 has 12 insertion holes 31 formed at equal intervals on a circumference centered on the central axis C1. The insertion holes 31 extend upward by a cylindrical support wall 32 that extends upward. The double-headed tool jig 10 may include the rotating plate 30.

[0019] Next, a method for attaching the double-ended tool 20 to the double-ended tool jig 10 and a manufacturing method for performing a coating process after attaching the double-ended tool 20 to obtain a coated double-ended tool 20 will be described.

[0020] First, a double-headed tool 20 to be coated is prepared. Next, a double-headed tool jig 10 is prepared that has a shape and dimensions that fit the prepared double-headed tool 20. That is, a double-headed tool jig 10 having an appropriate inner diameter and overall length of the jig body 11 is prepared according to the diameter and overall length of the prepared double-headed tool 20, specifically according to the lengths of the first cutting portion 22 and second cutting portion 23 to be coated or the length of the intermediate portion 21 not to be coated.

[0021] Next, the double-headed tool 20 is inserted from the upper open end of the jig body 11 of the double-headed tool jig 10, specifically from the open end on the side of the engagement portion 12. The double-headed tool 20 inserted from the upper open end of the double-headed tool jig 10 is prevented from slipping out of the lower open end by the locking portion 14 of the double-headed tool jig 10 locking with the locking surface of the double-headed tool 20, specifically with the surface of the groove 24 of the first cutting portion 22, and more specifically with the raised portion of the groove 24 near the middle portion 21. In other words, the double-headed tool 20 is locked to the double-headed tool jig 10 by gravity.

[0022] Twelve double-headed tools 20 held by a double-headed tool jig 10 are prepared, and each is attached to an insertion hole 31 of a rotating plate 30. Specifically, the double-headed tool jig 10 holding the double-headed tool 20 is inserted from the upper open end of the support wall 32 of the rotating plate 30. The inserted double-headed tool jig 10 and double-headed tool 20 are attached to the rotating plate 30 by locating the upper part of the support wall 32 of the rotating plate 30 in the fitting groove 13 of the double-headed tool jig 10. In this state, the double-headed tool jig 10 and double-headed tool 20 are attached to the rotating plate 30 so as to be rotatable around a common central axis C2. Therefore, the outer diameter of the jig body 11 of the double-headed tool jig 10 is slightly larger than the inner diameter of the support wall 32 of the rotating plate 30. The central axis C2 is the axis of rotation. At this time, the lower end surface of the double-headed tool jig 10, i.e., the lower end surface of the jig body 11, is flush with the lower surface of the rotating plate 30. The lower end surface of the double-headed tool jig 10 may be configured to protrude further than the lower surface of the rotating plate 30. The locking portion 14 protrudes slightly downward from the lower end surface of the double-headed tool jig 10 and the lower surface of the rotating plate 30. The central axis C1 of the rotating plate 30 and the central axis C2 of the double-headed tool jig 10 and the double-headed tool 20 are parallel to each other.

[0023] It is preferable to attach the double-headed tool jig 10 and the double-headed tool 20 to all of the insertion holes 31 of the rotating plate 30, as this ensures that the rotating plate 30 can be balanced when it rotates, as described below. This allows for a uniform coating process. It is also possible to have insertion holes 31 to which the double-headed tool jig 10 and the double-headed tool 20 are not attached, as long as the rotating plate 30 can be balanced when it rotates. The number of insertion holes 31 provided on the rotating plate 30 may be less than 12 or more than 12. The diameter of the rotating plate 30 may be determined depending on the number of insertion holes 31.

[0024] In this state, the first cutting edge 22 of the double-headed tool jig 10, which protrudes downward, and the second cutting edge 23 of the double-headed tool 20, which protrudes upward, protrude evenly from the corresponding opening end of the double-headed tool jig 10. Before the coating process, the first cutting edge 22 and the second cutting edge 23 are identical except for their physical positions, i.e., the first cutting edge 22 is located at the bottom and the second cutting edge 23 is located at the top.

[0025] Next, the double-headed tool jig 10, the double-headed tool 20, and the rotating plate 30 are placed in a chamber (not shown). The chamber has an inner wall perpendicular to the horizontal, and at least one coating material used in a predetermined physical vapor deposition method is placed on the inner wall. The double-headed tool jig 10 and the double-headed tool 20 are placed in the chamber together with the rotating plate 30 that holds them. At this time, the double-headed tool jig 10, the double-headed tool 20, and the rotating plate 30 are placed so that the central axis C1 of the rotating plate 30, and therefore the central axis C2 of the double-headed tool jig 10 and the double-headed tool 20, are parallel to the vertical direction. As a result, the first cutting edge 22 and the second cutting edge 23 of the double-headed tool 20 are spaced approximately equally apart from the coating material. It is also preferable that the double-headed tool jig 10, the double-headed tool 20, and the rotating plate 30 are placed so that they are equally surrounded by multiple coating materials.

[0026] The double-headed tool jig 10 and the double-headed tool 20 are connected to a power unit so as to rotate about a central axis C2 within the chamber. At this time, the recess 12a of the engagement portion 12 engages with a part of the power unit, so that the double-headed tool jig 10 and the double-headed tool 20 rotate about the central axis C2. The rotating plate 30 is connected to the power unit so as to rotate about a central axis C1 within the chamber. Furthermore, multiple rotating plates 30 may be arranged concentrically and connected to the power unit so as to rotate about the rotation axis.

[0027] Next, while rotating the double-headed tool jig 10 and the double-headed tool 20 about the central axis C2 and while rotating the rotating plate 30 about the central axis C1, and while rotating the multiple rotating plates 30, and thus the double-headed tool jig 10 and the double-headed tool 20 about their rotation axes, a coating process is performed by a predetermined physical vapor deposition method. This allows the coating to be applied uniformly to all of the double-headed tool jig 10.

[0028] The middle portion 21 of the double-headed tool 20 is covered by the jig body 11 of the double-headed tool jig 10, while the first cutting edge 22 and the second cutting edge 23 of the double-headed tool 20 are exposed. Therefore, the coating process is not performed on the middle portion 21 of the double-headed tool 20, and only the first cutting edge 22 and the second cutting edge 23 are coated. Finally, after the coating process, the double-headed tool jig 10, the double-headed tool 20, and the rotating plate 30 are all removed from the chamber, and the coated double-headed tool 20 is obtained.

[0029] Physical vapor deposition methods used for coating treatment include, for example, ion plating, sputtering, and vacuum deposition. Coating materials used for physical vapor deposition are, for example, TiN, TiCN, and TiAlN, and are selected appropriately depending on the required specifications, such as wear resistance, heat resistance, and lubricity. Other methods and / or other coating materials may also be used for the coating treatment as long as the required specifications are met.

[0030] Table 1 summarizes the thickness of the coating formed on the first and second cutting edges of a double-ended tool in a single coating process in an embodiment of the present invention and in two separate coating processes in a comparative example. Specifically, Table 1 shows the results of coating a double-ended center hole drill with diameters of Φ5, Φ6, Φ7.7, Φ8, Φ10, and Φ12 using an arc ion plating method with TiN as the coating material at 500°C or less for 60 minutes. In the comparative example, a double-ended tool jig was used that exposed only one cutting edge of the double-ended tool. Therefore, in the comparative example, after the first coating process on the first cutting edge, the double-ended tool jig, double-ended tool, and rotating plate were all removed. Next, the double-ended tool was attached to the double-ended tool jig in the opposite direction and placed back in the chamber, and a second coating process was performed on the second cutting edge.

[0031] [Table 1]

[0032] In Table 1, the average value is the average absolute value of the difference in film thickness between the first cutting portion and the second cutting portion, and the maximum value is the maximum absolute value of the difference in film thickness between the first cutting portion and the second cutting portion. As shown in Table 1, regardless of the diameter of the double-headed tool, the examples of the present invention have a lower average film thickness difference and a lower maximum film thickness difference than the comparative examples. Therefore, it was found that the examples of the present invention performed a more stable and uniform coating process.

[0033] 6 is a side view of the double-ended tool 20 after the coating process. A coating 26 is applied to the surface of the first cutting portion 22. A boundary 26a is formed between the coating 26 and the intermediate portion 21, as the intermediate portion 21 is covered by the jig body 11 of the double-ended tool jig 10. Similarly, a coating 27 is applied to the surface of the second cutting portion 23. A boundary 27a is formed between the coating 27 and the intermediate portion 21, as the intermediate portion 21 is covered by the jig body 11 of the double-ended tool jig 10.

[0034] The coating 26 applied to the first cutting portion 22 has a locking mark 28 formed near the boundary 26a. The locking mark 28 is a small area that was not coated because the locking surface of the double-ended tool 20, specifically the cut-out portion of the groove 24, was slightly covered by the locking portion 14 of the double-ended tool jig 10 during the coating process. In other words, the first cutting portion 22 is coated except for the locking mark 28 with the locking portion 14. Because the locking mark 28 is a small area, the absence of coating in this area does not affect the machining performance, etc., of the double-ended tool 20. Furthermore, the uncoated locking mark 28 can be used as an identification mark or area indicating that the double-ended tool 20 was manufactured using the double-ended tool jig 10 according to an embodiment of the present invention.

[0035] According to the coating process using the double-ended tool jig 10, a uniform coating can be applied to both cutting edges of the double-ended tool 20 in a single coating process. Furthermore, a double-ended tool manufacturing method using the double-ended tool jig 10 and a double-ended tool 20 manufactured using the same can be provided. Because the first cutting edge 22 and the second cutting edge 23 can be simultaneously coated in a single coating process, the processing time can be reduced by approximately half or more compared to two separate processes. Furthermore, since the physical vapor deposition method requires only one heating step for the chamber, manufacturing costs such as electricity costs associated with the coating process can be reduced. Furthermore, damage to the double-ended tool 20 due to heating during the coating process is also limited to a single step, resulting in a double-ended tool 20 with more stable quality.

[0036] The double-ended tool jig 10 can be configured in any manner as long as it includes a cylindrical jig body 11 into which the double-ended tool 20 can be inserted, and locking portions 14 provided on the jig body 11 to engage with the locking surfaces of the double-ended tool 20 so that the first cutting edge 22 and the second cutting edge 23 of the double-ended tool 20 inserted from one open end of the jig body 11 each protrude evenly from the corresponding open end or the other open end. For example, the locking portion 14 is provided on the lower end surface of the jig body 11, but it may also be provided on the inner surface near the lower end of the jig body 11. There may be one locking portion 14, but it is preferable to have at least two. It is preferable that the at least two locking portions 14 are arranged symmetrically around the central axis. Furthermore, the locking surface of the double-headed tool 20 that locks with the locking portion 14 may be provided at any location other than the cut-out portion of the groove 24, as long as it can lock with the locking portion 14 of the double-headed tool jig 10. As for the shapes of the mounting portions of the double-headed tool jig 10 and the rotating plate 30, the double-headed tool jig 10 and the rotating plate 30 can be configured arbitrarily, as long as the double-headed tool jig 10 that holds the double-headed tool 20 can be mounted in an upright position. [Explanation of symbols]

[0037] 10 Double-headed tool jig 11 Jig body 12 Engagement portion 13 Fitting groove 14 Locking portion 20 Double-ended tool 21 Middle section 22 1st blade part 23 2nd blade part 24 groove 25 groove 26 Coating 26a Boundary 27 Coating 27a boundary 28 Locking marks 30 Rotating Plate 31 Insertion hole 32 Supporting wall C1 center axis C2 center axis

Claims

1. a cylindrical jig body into which a double-headed tool having cutting edges at both ends of a columnar intermediate portion can be inserted; a locking portion provided on the jig body to lock with a locking surface of the double-headed tool so that each of the blades of the double-headed tool inserted from one open end of the jig body protrudes evenly from the one open end or the other open end.

2. 2. The jig for a double-headed tool according to claim 1, wherein the locking surface is a surface of a groove provided in the cutting portion, and the locking portion is a protrusion that protrudes radially inward.

3. 3. The jig for a double-headed tool according to claim 2, wherein the locking portion has at least two of the protrusions, and the at least two protrusions are arranged at symmetrical positions around the central axis.

4. 2. The jig for a double-headed tool according to claim 1, further comprising a circular rotating plate having a plurality of insertion holes provided at equal intervals on a circumference centered on the rotation axis, wherein the plurality of jig bodies are inserted into the plurality of insertion holes and arranged so that the central axis of each of the plurality of jig bodies is parallel to the rotation axis of the rotating plate.

5. a step of inserting a double-headed tool having cutting edges at both ends of a columnar intermediate portion from one open end of a cylindrical jig body; a step of engaging a surface of a groove provided in the blade portion with an engaging portion provided on the jig body so that each of the blade portions of the double-headed tool inserted into the jig body uniformly protrudes from one opening end or the other opening end; a step of performing a coating process on the cutting edge of the double-headed tool inserted into the jig body; and obtaining the double-ended tool in which the cutting edge portion other than the engagement mark with the engagement portion is coated.

6. A double-headed tool having a first cutting edge portion and a second cutting edge portion at each end of a columnar intermediate portion, a coating is applied to the first cutting edge portion and the second cutting edge portion excluding the intermediate portion; A double-headed tool, characterized in that at least a part of the first cutting edge is provided with an identification area where no coating is applied.

Images