Manufacturing method of metal member

Abstract

To reduce the time in forming a plurality of recesses on an outer surface of a metallic member.SOLUTION: In a method of manufacturing a metallic member, a plurality of laser beams from the same laser device are radiated to a plurality of radiation areas separated away from each other on an outer surface of the metallic member, thereby forming recesses in the respective radiation areas.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a method for manufacturing a metal component. [Background technology]

[0002] A technique is known in which a large number of recesses are formed on the outer surface of a metal member, and the recesses on the outer surface of the metal member are bonded to a resin member by an anchor effect. Also, as described in Patent Document 1, a technique is known in which a large number of recesses are formed on the outer surface of a metal member by irradiating the metal member with a laser beam in order to bond the metal member to a resin member by an anchor effect. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2015-100959 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the technique disclosed in Patent Document 1, a large number of recesses are formed on the outer surface of the metal member by sequentially irradiating the metal member with a single laser beam, which means that it takes a long time to form the recesses. In one aspect of the present disclosure, it is desirable to reduce the time required to form a plurality of recesses in an outer surface of a metal member. [Means for solving the problem]

[0005] One aspect of the present disclosure is a method for manufacturing a metal component, comprising simultaneously irradiating multiple laser beams from the same laser device to multiple irradiation areas that are spaced apart from one another on an outer surface of the metal component, thereby forming recesses in each irradiation area.

[0006] According to the above-described configuration, a plurality of recesses are formed on the outer surface of the metal member by simultaneously irradiating the outer surface with a plurality of laser beams, thereby reducing the time required to form a plurality of recesses on the outer surface of the metal member.

[0007] In one aspect of the present disclosure, when forming recesses in a plurality of irradiation regions by irradiation with a plurality of laser beams, a high period and a low period may alternate multiple times. In the high period, the intensity of each laser beam may be at a high level, and in the low period, the intensity of each laser beam may be at a low level lower than the high level. The low period may be longer than the high period.

[0008] According to the above configuration, when a plurality of laser beams are irradiated, the portions between adjacent recesses in the metal member are melted, which can prevent these recesses from being crushed. In one aspect of the present disclosure, the plurality of illuminated regions may be substantially circular, and the spacing between adjacent illuminated regions may be greater than the diameter of the illuminated regions.

[0009] According to the above configuration, the interval between the first and second irradiation regions can be prevented from narrowing, and therefore, when a plurality of laser beams are irradiated, the portion between the first and second irradiation regions in the metal member can be prevented from melting, and the recesses formed in the first and second irradiation regions can be prevented from collapsing. [Brief description of the drawings]

[0010] [Figure 1] FIG. 2 is an explanatory diagram of a laser device. [Diagram 2] FIG. 2 is an explanatory diagram of pulsed laser light irradiation. [Diagram 3] 4 is an explanatory diagram of a laser light irradiated region on an outer surface of a metal member. FIG. [Figure 4] 1 is a cross-sectional view of a metal member having a plurality of recesses formed therein; [Diagram 5] 13 is a table showing the evaluation results of a plurality of recesses formed by pulse irradiation in settings (1) to (6). DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. Note that the embodiments of the present disclosure are not limited to the following embodiments, and various forms may be adopted as long as they fall within the technical scope of the present disclosure.

[0012] [1. Overview] In the manufacturing method of this embodiment, a metal member 2 having a large number of hole-like recesses 4 formed on its outer surface is manufactured by a laser device 1 (see Figs. 1, 3, and 4). As an example, the portion of the outer surface of the metal member 2 having the large number of recesses 4 formed thereon is joined to a resin member with improved joining strength due to the anchor effect, thereby forming a composite member including the joined metal member 2 and the resin member. Of course, the metal member 2 having the large number of recesses 4 formed thereon may be used for purposes other than joining to a resin member.

[0013] [2. Laser device] The laser device 1 includes a laser oscillator 10, an optical path 11, and a head 12, and is configured to irradiate the outer surface of the metal member 2 with a plurality of laser beams L from the head 12 (see FIG. 1).

[0014] The laser oscillator 10 generates laser light by exciting a laser medium and amplifying the light emitted by the excited laser medium. As an example, the laser oscillator 10 may be configured as a fiber laser that uses an optical fiber as an amplifying medium.

[0015] The optical path 11 guides the laser light generated by the laser oscillator 10 to the head 12 . The head 12 has a collimation unit 13, a DOE (Diffractive Optical Element) 14, a focus lens 15, and a position correction unit 16. It is to be noted that the head 12 does not necessarily have to have the position correction unit 16.

[0016] The collimation unit 13 is a portion that adjusts the direction of the laser light guided from the laser oscillator 10 by, for example, a lens and / or a mirror. The DOE 14 splits the laser light L that has passed through the optical path 11 to generate a plurality of laser lights L. The plurality of laser lights L generated by the DOE 14 are irradiated from the head 12.

[0017] The focus lens 15 is a portion that adjusts the aperture of each laser beam L. The aperture of each laser beam L is adjusted so that the laser beams L converge immediately before the metal member 2 during welding. The position correction unit 16 is a part that adjusts the position at which each laser light L that has passed through the focus lens 15 is irradiated.

[0018] The multiple laser beams L can be generated by various methods, not limited to the above method. Specifically, for example, the multiple laser beams L may be generated by splitting one laser beam into multiple beams using a splitting mirror. Also, for example, the multiple laser beams L may be generated by splitting one laser beam using a PLC splitter that splits one optical fiber into multiple optical fibers.

[0019] Alternatively, for example, a plurality of laser beams may be combined by a coherent beam combining technique, thereby setting a profile of the plurality of laser beams L irradiated onto the outer surface of the metal member 2.

[0020] [3.Metal component manufacturing method] In the manufacturing method of this embodiment, a laser device 1 irradiates each of a large number of dot-like irradiation regions 3 on the outer surface of a metal member 2 with a plurality of laser beams L, thereby forming recesses 4 in each irradiation region 3 (see FIGS. 1, 3 and 4). The manufacturing method includes a setting step in which settings are made for the plurality of laser beams L to be irradiated from the laser device 1, and an irradiation step in which the metal member 2 is irradiated with the plurality of laser beams L.

[0021] [(1) Setting process] In the setting step, a profile of the multiple laser beams L irradiated in the irradiation step is set by an operator operating the laser device 1. Specifically, for example, the wavelength, intensity, and intensity distribution of the multiple laser beams L, the shape, size, and position of the irradiation area 3 of each laser beam L on the outer surface of the metal member 2, whether or not to perform pulse irradiation, and the angle of the multiple laser beams L with respect to the outer surface of the metal member 2 may be set.

[0022] As an example, each of the projection areas 3 is set as a dot-like area. More specifically, each of the projection areas 3 may be set as a substantially circular area having a diameter D1 (see FIG. 3). Of course, this is not limiting, and each of the projection areas 3 may be set as a substantially regular polygonal area. Also, each of the projection areas 3 may have a different shape.

[0023] Also, as an example, each irradiation area 3 may be set to be arranged in a matrix. The distance D2 between the two closest irradiation areas 3, in other words, the shortest distance D2 to be secured between two adjacent irradiation areas 3, may be set to a value larger than D1, which is the diameter of the irradiation area 3 (see FIGS. 3 and 4). Of course, this is not limiting, and D2 may be set to a value equal to or smaller than D1. Also, for some of the multiple irradiation areas 3, D2 may be set to be larger than D1.

[0024] The arrangement of the irradiation areas 3 can also be appropriately determined, and for example, the irradiation areas 3 may be arranged in a line or may be irregularly arranged. Of course, even in such a case, D2 may be set to a value larger than D1 or may be set to a value equal to or smaller than D1.

[0025] Also, as an example, pulse irradiation may be performed. In the case where pulse irradiation is performed, when a plurality of laser beams L are irradiated to form the recesses 4, each laser beam L alternates between a high state and a low state (see FIG. 2). The high state means a state where a laser beam of a predetermined intensity (hereinafter, high level) is irradiated, and the low state means a state where the intensity of the laser beam is lower than the high level (hereinafter, low level). As an example, in this embodiment, in the low state, the intensity of the laser beam becomes 0, and the laser beam is not irradiated. In the case where pulse irradiation is performed, the length of the high period during which the high state continues and the length of the low period during which the low state continues may be set, and the number of pulse irradiations, in other words, the number of times each laser beam is made high to form each recess 4 may be set.

[0026] As an example, the low period may be set to be longer than the high period, but the present invention is not limited to this and the length of the low period may be set to be shorter than or equal to the length of the high period. In addition, when pulse irradiation is not performed, in the irradiation process, the recesses may be formed by not switching between high and low states of each laser light, but by maintaining the high state during the irradiation period of each laser light L.

[0027] Also, as an example, the angle of the multiple laser beams L with respect to the outer surface of the metal member 2 is set to approximately 90°, and the intensity of each laser beam L and the distribution of the intensity of the laser beam L in each irradiation region 3 are set so that an approximately conical recess 4 is formed (see FIG. 4). However, this is not limited to this, and the angle of the multiple laser beams L with respect to the outer surface of the metal member 2 may be an angle other than approximately 90°. Also, the shape of the recess 4 is not limited to approximately conical, and for example, a recess 4 having a rectangular or elliptical shape in a cross section perpendicular to the outer surface of the metal member 2 may be formed.

[0028] [(2) Profile details] The wavelength of each laser light L may be 1070 nm, for example. Of course, the wavelength of each laser light L is not limited to this, and is set appropriately.

[0029] Moreover, the distance D2 between two adjacent irradiation regions 3 is set appropriately. Moreover, the diameter D1 of each of the substantially circular irradiation regions 3 is also set appropriately. Furthermore, the number of pulses generated when forming recesses 4 by pulse irradiation is set appropriately.

[0030] In addition, during pulse irradiation, the intensity (W) of the laser light L irradiated to each irradiation region 3 in the high state is defined as P, the length of the high period is defined as Thi (ms), and the length of the low period is defined as Tlow (ms). Then, the evaluation index I is calculated according to the following formula.

[0031] I=P×Thi / Tlow The recesses 4 formed by pulse irradiation when P, Thi, and Tlow were set according to (1) to (6) in the table of Fig. 5 were confirmed. In the case of setting (4), the recesses 4 were not formed well. On the other hand, in the case of setting (6), the recesses 4 were formed well, and in the cases of settings (1) to (3) and (5), the recesses 4 were formed even better.

[0032] Therefore, P, Thi, and Tlow may be set so that I is 40.06667 or less, in other words, I is about 40 or less. This allows each recess 4 to be formed well. Alternatively, P, Thi, and Tlow may be set so that I is 21.46429 or less, in other words, I is about 21 or less. This allows each recess 4 to be formed even better.

[0033] [(3) Irradiation process] The irradiation step includes one or more irradiation cycles. In each irradiation cycle, a plurality of laser beams L having a profile set in the setting step are simultaneously irradiated from the head 12 of the laser device 1 toward the outer surface of the metal member 2. As a result, recesses 4 are formed in the irradiation areas 3 of the laser beams L on the outer surface of the metal member 2 (see FIG. 4).

[0034] The area of ​​the recesses 4 on the outer surface of the metal member 2 is larger than the area of ​​the irradiation region 3 in which the recesses 4 are formed (see FIGS. 3 and 4). In other words, each irradiation region 3 is located inside the region in which the recesses 4 are formed on the outer surface of the metal member 2.

[0035] When multiple irradiation cycles are performed, when each irradiation cycle is completed and multiple recesses 4 are formed on the outer surface of the metal member 2, both or one of the head 12 and the metal member 2 are moved, and a new area on the outer surface of the metal member 2 is set as the target area. Thereafter, the next irradiation cycle is started, and multiple laser beams L are irradiated onto the new target area to form the recesses 4. Then, when the required number of irradiation cycles are completed, the irradiation process ends.

[0036] On the other hand, when one irradiation cycle is performed, the irradiation step ends when one irradiation cycle is completed. [4. Effects] (1) According to the above embodiment, a plurality of laser beams L are simultaneously irradiated onto the outer surface of the metal member 2 from the head 12 of the laser device 1, thereby forming a plurality of recesses 4 on the outer surface. This allows the time required to form a plurality of recesses 4 on the outer surface of the metal member 2 to be reduced.

[0037] (2) In addition, since the low period in the pulse irradiation is longer than the high period, the amount of heat given to the metal member 2 during the pulse irradiation can be suppressed. Therefore, it is possible to suppress the portions between adjacent recesses 4 in the metal member 2 from melting due to the pulse irradiation, which would cause these recesses 4 to collapse.

[0038] (3) Moreover, since the interval D2 between adjacent irradiation regions 3 is larger than the diameter D1 of the substantially circular irradiation regions 3, it is possible to prevent the interval between adjacent irradiation regions 3 from becoming narrow. Therefore, when a plurality of laser beams L are irradiated, it is possible to prevent the portions between the adjacent irradiation regions 3 in the metal member 2 from melting and the recesses 4 formed in the irradiation regions from being crushed.

[0039] 5. Other embodiments A plurality of functions possessed by one component in the above embodiments may be realized by a plurality of components, or a single function possessed by one component may be realized by a plurality of components. A plurality of functions possessed by a plurality of components may be realized by a single component, or a single function realized by a plurality of components may be realized by a single component. A part of the configuration of the above embodiments may be omitted. At least a part of the configuration of the above embodiments may be added to or substituted for the configuration of another of the above embodiments. [Explanation of symbols]

[0040] Reference Signs List 1: laser device, 10: laser oscillator, 11: optical path, 12: head, 13: collimation section, 14: DOE, 15: focus lens, 16: position correction section, 2: metal member, 3: irradiation area, 4: recess.

Claims

[Claim 1] A method for manufacturing a metal member, comprising: The method includes simultaneously irradiating a plurality of laser beams from a single laser device to a plurality of irradiation regions spaced apart from each other on an outer surface of a metal member, thereby forming recesses in each of the irradiation regions so as to be spaced apart from each other; When forming the recesses in the plurality of irradiation regions by irradiating the plurality of laser beams, a high period and a low period occur alternately a plurality of times, In the high period, the intensity of each of the laser beams is at a high level, and in the low period, the intensity of each of the laser beams is at a low level that is lower than the high level, The length of the low period Tlow (ms) is longer than the length of the high period Thi (ms), The intensity of the laser light irradiated to each of the irradiation regions is P (W), I=P×Thi / Tlow Thi, Tlow, and P are adjusted so that the value of the evaluation index I calculated by is 21.46429 or less. A method for manufacturing a metal member.

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