Method of producing powder and cutting tool

Abstract

To provide a method of producing a powder that allows the production of a metal powder at higher rate.SOLUTION: A method of producing a powder includes cutting into a fixed workpiece while rotating a cutting tool having comb teeth mutually deviated in phase at at least two positions in a circumferential direction, and vibrating the tool in a cut-in direction such that a maximum depth of cut is smaller than a height of the comb teeth, thereby obtaining a metal powder.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a powder manufacturing method and a cutting tool.

Background Art

[0002] In recent years, 3D printers have attracted attention. In a 3D printer, generally, metal powder is formed into layers and irradiated with a laser to melt and solidify the metal, and sequential layer manufacturing is performed. Therefore, in order to form the metal powder into layers, it is required to manufacture metal powder having a low aspect ratio.

[0003] In relation to this, for example, Patent Document 1 below discloses a method for producing metal powder by rotating an elongated workpiece and repeatedly bringing the outer peripheral surface of the elongated workpiece into contact with a reciprocating cutter.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] The inventors of the present invention have intensively studied a method for manufacturing metal powder at a higher speed than the powder production method disclosed in Patent Document 1.

[0006] The present invention has been made as a result of such studies, and an object thereof is to provide a powder manufacturing method capable of manufacturing metal powder at a higher speed.

Means for Solving the Problems

[0007] The powder manufacturing method according to the present invention for achieving the above object is to rotate a cutting tool having comb teeth with a phase shift from each other at least at two positions in the circumferential direction, and while vibrating in the cutting direction so that the maximum cutting amount is less than the height of the comb teeth, cut into a fixed workpiece to obtain metal powder.

Advantages of the Invention

[0008] According to the present invention, since the cutting tool is provided with comb teeth having a phase shift from each other at least at two positions in the circumferential direction, after cutting the workpiece with one comb tooth, the workpiece can be further cut without idling with the other comb tooth. Therefore, powder can be manufactured at a higher speed.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Embodiments for Carrying Out the Invention

[0010] Hereinafter, embodiments of the present invention will be described with reference to the attached drawings. Note that the following description does not limit the technical scope or the meaning of terms described in the claims. Also, the dimensional ratios in the drawings are exaggerated for convenience of explanation and may be different from the actual ratios.

[0011] First, with reference to FIG. 1, the configuration of the cutting tool 1 according to this embodiment will be described.

[0012] As shown in Fig. 1, the cutting tool 1 has a main body portion 10 extending in the axial direction (the vertical direction in Fig. 1), and a pair of cutting portions 20 and 30 provided at one end (the lower end in Fig. 1) of the main body portion 10.

[0013] The cutting portions 20 and 30 are provided at 180-degree intervals along the circumferential direction of the main body portion 10. The cutting portions 20 and 30 may be integrally formed with the main body portion 10 or may be formed as separate bodies.

[0014] As shown in Fig. 2, on the outer peripheral surface of the cutting portion 20, numerous comb teeth 21 are formed at intervals of several tens of micrometers. Also, on the outer peripheral surface of the cutting portion 30, numerous comb teeth 31 are formed at intervals of several tens of micrometers. In Fig. 2, an enlarged view of the cutting portion 20 is shown on the left side, and an enlarged view of the cutting portion 30 is shown on the right side.

[0015] The height of the comb teeth 21 and 31 is not particularly limited, but is 5 to 100 μm. As shown in Fig. 2, the comb teeth 21 and 31 are formed so as to be out of phase with each other. In other words, as shown in Fig. 2, at the locations where the comb teeth 21 are convex in the vertical direction, the comb teeth 31 are concave, and at the locations where the comb teeth 21 are concave in the vertical direction, the comb teeth 31 are convex. Further in other words, the locations where the comb teeth 21 are convex and the locations where the comb teeth 31 are convex are shifted by half a pitch in the vertical direction.

[0016] By forming the comb teeth 21 and 31 so as to be out of phase with each other in this way, after the comb teeth 21 contact the workpiece W, when it rotates half a turn, the comb teeth 31 contact the workpiece W. Therefore, compared with a configuration where the phase is not shifted, metal powder can be produced at a production speed twice as fast.

[0017] As shown in FIGS. 1 and 2, the tips of the comb teeth 21 and 31 are formed in a triangular shape. Note that the tips of the comb teeth 121 and 221 may be formed in a curved shape as shown in FIG. 3, or may be formed in a trapezoidal shape as shown in FIG. 4. Among these, in the case of the trapezoidal shape shown in FIG. 4, since the metal powder generated when cut by a cutting tool becomes substantially cubic in shape, the aspect ratio of the metal powder can be made smaller, and a more desired metal powder can be obtained.

[0018] Next, with reference to FIG. 1, a powder manufacturing method using the cutting tool 1 according to the present embodiment will be described.

[0019] First, a workpiece W to be cut is prepared. The workpiece W is fixedly provided without rotating. The fixing means for fixing the workpiece W is not particularly limited.

[0020] Next, while rotating the cutting tool 1 around the vertical axis in FIG. 1, it is brought into contact with the end face W1 of the workpiece W. At this time, the cutting tool 1 is vibrated in the left - right direction in FIG. 1 by the vibration unit P. The vibration unit P is not particularly limited, but for example, it is a piezo - element.

[0021] The amplitude when vibrating the cutting tool 1 by the vibration unit P corresponds to the maximum cutting amount of the cutting tool 1, and it is vibrated so as to be less than the height of the comb teeth 21 and 31. By appropriately adjusting the vibration frequency, cutting amount, and pitch of the comb teeth of the cutting tool 1, the particle size of the obtained metal powder can be adjusted.

[0022] Then, the cutting tool 1 is gradually moved to the left in FIG. 1 to cut the workpiece W. In this way, since the cutting tool 1 can cut the entire workpiece W by cutting into the end face W1 of the workpiece W, the material yield is improved. Further, in the case of the method of cutting the outer peripheral surface W2 of the workpiece W described later, it is necessary to change the processing conditions as the outer diameter becomes smaller when cutting the outer peripheral surface W2 of the workpiece W, but when cutting the end face W1, it is not necessary to move the cutting tool 1 to the inner peripheral side, so there is no need to change the processing conditions.

[0023] As described above, in the powder manufacturing method according to the present embodiment, while rotating the cutting tool 1 having the comb teeth 21 and 31 that are phase-shifted from each other at least at two positions in the circumferential direction, the fixed workpiece W is cut while vibrating in the cutting direction so that the maximum cutting amount is less than the height of the comb teeth 21 and 31, and metal powder is obtained. According to this powder manufacturing method, since the cutting tool 1 has the comb teeth 21 and 31 that are phase-shifted from each other at least at two positions in the circumferential direction, after cutting the workpiece W with one comb tooth 21, the workpiece W can be further cut with the other comb tooth 31 without idling. Therefore, powder can be manufactured at a higher speed.

[0024] Further, the cutting tool 1 cuts into the end face W1 of the workpiece W. According to this powder manufacturing method, the material yield is improved and there is no need to change the processing conditions.

[0025] Further, while forcibly vibrating the cutting tool 1 by a piezoelectric element, the workpiece W is cut. According to this powder manufacturing method, since the vibration frequency of the cutting tool 1 can be appropriately adjusted, metal powder having a desired particle size can be preferably manufactured.

[0026] Further, as described above, the cutting tool 1 according to the present embodiment has the comb teeth 21 and 31 that are phase-shifted from each other at least at two positions in the circumferential direction. According to the cutting tool 1 configured in this way, after cutting the end face W1 of the workpiece W with one comb tooth 21, the end face W1 of the workpiece W can be further cut with the other comb tooth 31 without idling. Therefore, powder can be manufactured at a higher speed.

[0027] As described above, the powder manufacturing method and the cutting tool 1 according to the present invention have been described through the embodiments. However, the present invention is not limited to only the content described in the embodiments, and can be appropriately changed based on the description of the claims.

[0028] For example, in the above-described embodiment, the cutting tool 1 cut off the end face W1 of the workpiece W. However, as shown in FIG. 5, the cutting tool 1 may cut off the outer peripheral surface W2 of the workpiece W.

[0029] Also, in the above-described embodiment, the workpiece W was cut while forcibly vibrating the cutting tool 1. However, the cutting tool 1 may cut into the workpiece W while vibrating by self-excited vibration. According to this method, since a vibration part such as a piezo element becomes unnecessary, the device configuration can be simplified.

[0030] Also, in the above-described embodiment, two cutting parts 20 and 30 were provided so as to be on the opposite sides in the circumferential direction. However, the number of cutting parts provided is not particularly limited as long as it is two or more along the circumferential direction.

Explanation of Reference Numerals

[0031] 1 Cutting tool 21, 31, 121, 221 Comb teeth P Piezo element (vibration part) W Workpiece W1 End face of the workpiece W2 Outer peripheral surface of the workpiece

Claims

1. A powder manufacturing method for obtaining metal powder by rotating a cutting tool having comb teeth with a phase shift from each other at least at two positions in the circumferential direction, and cutting a fixed workpiece while vibrating in the cutting direction so that the maximum cutting amount is less than the height of the comb teeth.

2. The powder manufacturing method according to claim 1, wherein the cutting tool cuts into the end face of the workpiece.

3. The powder manufacturing method according to claim 1 or 2, wherein the cutting tool is forcibly vibrated by a vibrating portion while cutting the workpiece.

4. A cutting tool having comb teeth with a phase shift from each other at least at two positions in the circumferential direction.

Images