JP2016132156A - Joined structure and method for producing joined structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a joined structure which suppresses thermal diffusion of a metal member and enhances thermal melting properties of a resin member, and has excellent joining properties between the metal member and the resin member, even if irradiated laser energy is small when the metal member and the resin member are joined to each other by laser, and to provide a method for producing the joined structure.SOLUTION: A joined structure 1 has a joined region BF in which a metal member 2 and a resin member 3 are joined to each other. A recess 21 having an opening is formed in the joined region BF on the surface of the metal member 2. The recess 21 of the metal member 2 is filled with the resin member 3. In the metal member 2, a thin thickness portion 23 in which the thickness of the metal member 2 is thinned is provided in a region including the joined region BF and an adjacent region NF adjacent to the joined region BF.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a joint structure having a joint region in which a metal member and a resin member are joined, and a method for manufacturing the joint structure.

  Conventionally, patent document 1 is known as a manufacturing method of the joining structure which has the joining area | region where resin was joined.

  In Patent Document 1, a first member made of a transmissive thermoplastic resin that transmits laser light and a second member made of an absorptive thermoplastic resin that absorbs laser light are brought into contact with each other, and laser A method of laser welding a thermoplastic resin member that melts and joins contact surfaces with light, wherein the first member and the second member are brought into contact in a reduced-pressure atmosphere, and the two members are joined from the first member side. A laser welding method of a thermoplastic resin member for irradiating the contact surface with the laser beam is disclosed.

  According to Patent Document 1, a first member made of a transmissive thermoplastic resin that transmits laser light is brought into contact with a second member made of an absorptive thermoplastic resin that absorbs laser light, When the laser beam is irradiated from the side of the first member that transmits the laser beam, the laser beam generates heat by accumulating energy on the surface of the second member that does not transmit the laser beam. When the laser beam is further irradiated, the amount of heat generation increases, the contact surface with the first member is simultaneously heated through the contact surface, the contact surfaces of the two members are melted, and the two members are welded.

JP 2007-1111926 A

  The technique of Patent Document 1 is an invention related to the joining of resins, but when this invention is used for joining a resin member and a metal member, problems described below have occurred.

  When a resin member and a metal member are bonded by irradiating a laser in a reduced pressure atmosphere, thermal diffusion to the resin side is less likely to occur due to reduced pressure, and thermal diffusion to the metal member side is caused by a difference in thermal conductivity. Since it was overwhelmingly large, it was difficult for the resin member to melt by heat. Therefore, it is necessary to increase the laser irradiation energy in order to cause the resin member to melt and bond the resin member and the metal member. Thus, increasing the laser irradiation energy is not preferable from the viewpoint of energy saving.

  The present invention has been made in view of such a point, and the object of the present invention is to suppress thermal diffusion of the metal member even when the laser energy irradiated at the time of laser joining between the metal member and the resin member is small. It is an object of the present invention to provide a bonded structure and a method for manufacturing the bonded structure, in which the heat melting property of the resin member is improved and the bondability between the metal member and the resin member is good.

  In order to achieve the above object, the present invention is configured as follows.

  The joint structure according to the present invention is a joint structure having a joint region in which a metal member and a resin member are joined, and the joint region of the metal member has a concave shape having an opening on the surface of the metal member. And a concave portion of the metal member is filled with the resin member, and the metal member includes the joining region and an adjacent region adjacent to the joining region. A thin portion in which the thickness of the metal member is reduced is provided therein.

  Moreover, it is the said junction structure, Comprising: The said thin part may be formed in the said junction area | region.

  Moreover, it is the said junction structure, Comprising: The said thin part may be formed in the area | region including the said adjacent area | region at least.

  Moreover, it is the said junction structure, Comprising: The heat insulating material may be provided in the said thin part.

  Moreover, it is the said joining structure, Comprising: The thin part may be equipped with the reinforcement part which reinforces the said metal member.

  Moreover, it is the said joining structure, Comprising: The protrusion part which protrudes inside may be formed in the internal peripheral surface of the said recessed part.

  Moreover, the manufacturing method of the joining structure which concerns on this invention is a manufacturing method of the joining structure which has a joining area | region where the metal member and the resin member were joined, Comprising: In the said metal member, the said joining area | region and this joining A thin portion forming step of forming a thin portion where the thickness of the metal member is reduced in a region including the adjacent region adjacent to the region, and a concave shape having an opening in the bonding region on the surface of the metal member A concave portion forming step of forming a portion, an arrangement step of arranging the surface of the metal member and the resin member adjacent to each other, and irradiating a laser to a joining region of the metal member from the resin member side, thereby the metal member And a bonding step of filling and bonding the resin member to the concave portion.

  Further, in the method for manufacturing the bonded structure, in the bonding step, when the laser is irradiated on the bonding region of the metal member, the laser is scanned in the bonding region, and a plurality of the scans are performed with the same locus. It may be performed once.

  Moreover, it is a manufacturing method of the said junction structure, Comprising: In the said recessed part formation process, you may form the said recessed part by irradiating the laser with which 1 pulse consists of several subpulses.

  According to the present invention, even when the laser energy irradiated at the time of laser joining between the metal member and the resin member is small, the thermal diffusion of the metal member is suppressed and the heat melting property of the resin member is improved. It is possible to provide a bonded structure having good bondability and a method for manufacturing the bonded structure.

FIG. 1 is an explanatory view for explaining an arrangement step in the method for manufacturing a bonded structure according to the present invention. FIG. 2 is an explanatory view for explaining a joining step in the method for manufacturing a joined structure according to the present invention. FIG. 3 is a cross-sectional view of the first embodiment of the bonded structure according to the present invention. FIG. 4A is a diagram showing a modification of the first embodiment of the joint structure according to the present invention. FIG. 4B is a view showing another modification of the first embodiment of the joint structure according to the present invention. FIG. 4C is a diagram showing still another modification of the first embodiment of the joint structure according to the present invention. FIG. 5 is a cross-sectional view of still another modification of the first embodiment of the bonded structure according to the present invention. FIG. 6 is a perspective view of still another modified example of the first embodiment of the bonded structure according to the present invention. FIG. 7 is a perspective view of still another modified example of the first embodiment of the bonded structure according to the present invention. FIG. 8 is a cross-sectional view of a second embodiment of the bonded structure according to the present invention. FIG. 9A is a diagram showing a modification of the second embodiment of the joint structure according to the present invention. FIG. 9B is a diagram showing another modified example of the second embodiment of the joint structure according to the present invention. FIG. 9C is a diagram showing still another modification of the second embodiment of the joint structure according to the present invention. FIG. 10 is a cross-sectional view of a third embodiment of the joint structure according to the present invention. FIG. 11 is a cross-sectional view of a modified example of the third embodiment of the bonded structure according to the present invention. FIG. 12 is a perspective view of another modification of the third embodiment of the joint structure according to the present invention. FIG. 13 is an explanatory diagram schematically illustrating an example of the bonded structure according to the first embodiment. FIG. 14 is an explanatory diagram schematically illustrating an example of the bonded structure according to the third embodiment.

(First embodiment)
Hereinafter, the joint structure 1 according to the first embodiment of the present invention and the method for manufacturing the joint structure 1 will be described with reference to FIGS.

  FIG. 1 is an explanatory diagram for explaining an arrangement step in a method for manufacturing a joined structure, FIG. 2 is an explanatory diagram for explaining a solidifying step in the method for producing a joined structure, and FIG. 3 is a first diagram of the joined structure. 4A to 4C are cross-sectional views showing a modification of the first embodiment of the joint structure, and FIG. 5 is a cross-sectional view of another modification of the first embodiment of the joint structure. FIG. 6 is a perspective view of still another modified example of the first embodiment of the joined structure, and FIG. 7 is a perspective view of still another modified example of the first embodiment of the joined structure.

−Composition structure−
First, the bonded structure 1 according to the first embodiment of the present invention will be described.

  The bonding structure 1 of the present embodiment is a bonding structure 1 in which a metal member 2 and a resin member 3 are bonded by a laser, and has a bonding region BF in which the metal member 2 and the resin member 3 are bonded. ing.

  Examples of the metal member 2 include iron metal, stainless steel metal, copper metal, aluminum metal, magnesium metal, and alloys thereof. Moreover, a metal molding may be sufficient and zinc die-casting, aluminum die-casting, powder metallurgy, etc. may be sufficient.

  A concave portion 21 having an opening on the surface of the metal member 2 is formed in the bonding region BF of the metal member 2. The concave portion 21 is a substantially circular non-through hole when seen in a plan view, and a plurality of the concave portions 21 are formed on the surface of the metal member 2. In addition, the shape of a recessed part is not limited to a non-through-hole, For example, a groove shape may be sufficient if a cross section is a concave shape.

  The opening diameter of the concave portion 21 is preferably 30 μm or more and 100 μm or less. This is because, when the aperture diameter is less than 30 μm, the bonding laser irradiated in the bonding process described later is not sufficiently confined in the concave portion 21, and the conversion efficiency for converting the energy of the bonding laser into heat decreases. It is because there is a case to do. On the other hand, when the opening diameter exceeds 100 μm, the number of the concave portions 21 per unit area decreases, and the conversion efficiency for converting the energy of the laser for bonding into heat may decrease. Moreover, it is preferable that the depth of the recessed part 21 is 10 micrometers or more. This is because if the depth is less than 10 μm, the conversion efficiency for converting the energy of the laser for bonding into heat may decrease.

  The interval between the concave portions 21 (the distance between the center of the predetermined concave portion 21 and the center of the concave portion 21 adjacent to the predetermined concave portion 21) is preferably 200 μm or less. This is because if the interval between the concave portions 21 exceeds 200 μm, the number of the concave portions 21 per unit area decreases, and the conversion efficiency for converting the energy of the laser for bonding into heat may decrease. . An example of the lower limit of the interval between the concave portions 21 is a distance at which the concave portions 21 are not overlapped and crushed. Moreover, it is preferable that the space | interval of the recessed part 21 is equal intervals. This is because when the concave portions 21 are equidistant, the heat distribution when the bonding laser is irradiated is isotropic.

  The metal member 2 and the resin member 3 are joined to each other by filling the concave portion 21 with a resin member 3 described later. Here, the concave portion 21 of the present embodiment is formed with a protruding portion 22 that protrudes inward. Thus, when the protrusion part 22 which protrudes inside is formed in the internal peripheral surface of the concave part 21, if the resin member 3 is filled into the concave part 21, the metal member 2 will be obtained by the anchor effect by the protrusion part 22. And the resin member 3 can be increased in bonding strength. Note that the protrusion 22 may not be formed in the concave portion 21.

  In the metal member 2, a thin portion 23 in which the thickness of the metal member 2 is reduced is provided in a region including the bonding region BF and the adjacent region NF adjacent to the bonding region BF (see FIG. 3). In the illustrated example, a hole is formed on the back surface of the metal member 2 to form a thin portion 23. In addition, the shape of the back surface processing of the metal member 2 is not limited to the hole shape, and may be a groove shape, for example. That is, any shape may be used as long as the metal member 2 is thin.

  In the illustrated example, the thin portion 23 is formed in the bonding region BF, but the concave portion 21 may be formed over the adjacent region NF adjacent to the bonding region BF. Here, the adjacent region NF may reduce thermal diffusion in the laser irradiation direction (thickness direction of the metal member 2) even when the laser is applied to the bonding region BF of the metal member 2 in the bonding process described later. The area should be as large as possible.

  The shape of the thin portion 23 is not limited to the shape of FIG. 3, and as shown in FIG. 4A, the shape gradually thinned from the center of the bonding region BF toward the region end of the bonding region BF, As shown in FIG. 4B, the joining region BF on the back surface of the metal member 2 is processed into a trapezoidal shape in a cross-sectional view and thinned, or the joining region BF on the back surface of the metal member 2 is cross-sectionally shown in FIG. The shape may be thinned by processing by penetrating in a circular arc shape.

  Further, the thin portion 23 may be provided with a heat insulating material 25 (see FIG. 5). An example of the heat insulating material 25 is a heat insulating material made of foamed resin. As described above, when the thin-walled portion 23 is provided with the heat insulating material 25, in the bonding step in the manufacturing method of the bonded structure 1 to be described later, the bonding region BF is irradiated with a laser, and the metal member 2 and the resin member 3 When bonding is performed, the effect of confining heat in the bonding region BF can be enhanced.

  Further, the thin portion 23 may include a reinforcing portion 24 that reinforces the metal member 2 (see FIGS. 6 and 7). As shown in FIG. 6, the reinforcing portion 24 may be disposed so as to be diagonally connected to each other in the groove formed on the back surface of the metal member 2, or as shown in FIG. A plurality of them may be arranged in parallel so as to connect each other. Thus, when the thin part 23 is provided with the reinforcing part 24 that reinforces the metal member 2, the strength of the metal member 2 can be increased.

  The resin member 3 is a thermoplastic resin or a thermosetting resin. Examples of the thermoplastic resin include PVC (polyvinyl chloride), PS (polystyrene), AS (acrylonitrile / styrene), ABS (acrylonitrile / butadiene). -Styrene), PMMA (polymethyl methacrylate), PE (polyethylene), PP (polypropylene), PC (polycarbonate), m-PPE (modified polyphenylene ether), PA6 (polyamide 6), PA66 (polyamide 66), POM (polyacetal) ), PET (polyethylene terephthalate), PBT (polybutylene terephthalate), PSF (polysulfone), PAR (polyarylate), PEI (polyetherimide), PPS (polyphenylene sulfide), PES (polyethersulfur) ), PEEK (polyetheretherketone), PAI (polyamideimide), LCP (liquid crystal polymer), PVDC (polyvinylidene chloride), PTFE (polytetrafluoroethylene), PCTFE (polychlorotrifluoroethylene), and PVDF (Polyvinylidene fluoride). TPE (thermoplastic elastomer) may also be used, and examples of TPE include TPO (olefin-based), TPS (styrene-based), TPEE (ester-based), TPU (urethane-based), TPA (nylon-based), And TPVC (vinyl chloride type) is mentioned.

  Examples of thermosetting resins include EP (epoxy), PUR (polyurethane), UF (urea formaldehyde), MF (melamine formaldehyde), PF (phenol formaldehyde), UP (unsaturated polyester), and SI (silicone) Is mentioned. Further, it may be FRP (fiber reinforced plastic).

  Note that a filler may be added to the thermoplastic resin and the thermosetting resin. Examples of the filler include inorganic fillers (glass fibers, inorganic salts, etc.), metal fillers, organic fillers, and carbon fibers.

-Manufacturing method of bonded structure-
Next, a method for manufacturing the bonded structure 1 according to the present embodiment will be described.

  The manufacturing method of the junction structure 1 according to the present embodiment includes a thin portion forming step, a concave portion forming step, an arranging step, and a joining step. Hereinafter, although each process is demonstrated, the order of the process of the manufacturing method of the junction structure concerning this embodiment is not limited to the order to explain.

Thin part forming process The thin part forming process is a thin part in which the thickness of the metal member 2 is reduced in the metal member 2 in a region including the bonding region BF and the adjacent region NF adjacent to the bonding region BF. 23 is a step of forming 23.

  For forming the thin portion 23, a method of laser processing the metal member 2 or a method of forming a metal member 2 having the thin portion 23 by using a mold for forming the thin portion 23 in advance. However, it is not limited to these methods.

  In addition, the shape of the thin part 23 is not limited to the shape of FIG. 3, The shape shown to FIG. 4A-FIG. 4C may be sufficient. Moreover, you may form the heat insulating material 25 in the thin part 23 (refer FIG. 5). Moreover, you may form the reinforcement part 24 which reinforces the metal member 2 in the thin part 23 (FIG.6 and FIG.7).

-Concave part formation process The concave part formation process is a process of forming the concave part 21 having an opening in the bonding region BF on the surface of the metal member 2.

  The concave portion 21 is formed by a known method such as laser processing, blast processing, sandpaper processing, anodizing processing, electric discharge processing, etching processing, or press processing. In the present embodiment, a method for forming the concave portion 21 by laser processing will be described in detail.

The type of processing laser that forms the concave portion 21 is preferably a laser capable of pulse oscillation, and can be selected from a fiber laser, a YAG laser, a YVO ₄ laser, a semiconductor laser, a carbon dioxide gas laser, and an excimer laser, and considers the wavelength of the laser. Then, a fiber laser, a YAG laser, a second harmonic of a YAG laser, a YVO ₄ laser, and a semiconductor laser are preferable. The concave portion 21 is a substantially circular non-through hole as viewed in plan, and a plurality of the concave portions 21 are formed on the surface of the metal member 2.

  As an example of an apparatus for forming the concave portion 21, there can be mentioned a fiber laser marker MXZ2000 or MX-Z2050 manufactured by OMRON. With this fiber laser marker, it is possible to irradiate a laser where one pulse is composed of a plurality of subpulses. For this reason, the energy of the laser is easily concentrated in the depth direction, which is suitable for forming the concave portion 21.

  Specifically, when the metal member 2 is irradiated with a laser, the metal member 2 is locally melted, so that the formation of the concave portion 21 proceeds. At this time, since the laser is composed of a plurality of sub-pulses, the molten metal member 2 is not easily scattered and is easily deposited in the vicinity of the concave portion 21. When the formation of the concave portion 21 proceeds, the molten metal member 2 is deposited inside the concave portion 21, thereby forming a protruding portion 22 that protrudes inward on the inner peripheral surface of the concave portion 21. .

  As a processing condition by the fiber laser marker, it is preferable that one period of the sub-pulse is 15 ns or less. This is because when one period of the sub-pulse exceeds 15 ns, energy is easily diffused by heat conduction, and it becomes difficult to form the concave portion 21 having the protruding portion 22. Note that one cycle of the subpulse is a total time of the irradiation time for one subpulse and the interval from the end of the irradiation of the subpulse to the start of the irradiation of the next subpulse.

  Further, as a processing condition by the fiber laser marker, the number of subpulses of one pulse is preferably 2 or more and 50 or less. This is because if the number of subpulses exceeds 50, the output per unit of subpulses becomes small, and it becomes difficult to form the concave portion 21 having the protruding portions 22.

  In addition, although it is preferable to perform a recessed part formation process after a thin part formation process from a viewpoint of cost, you may perform the thin part formation process mentioned above after a recessed part formation process.

-Arrangement | positioning process An arrangement | positioning process is a process of arrange | positioning the surface of the metal member 2 and the resin member 3 adjacently (refer FIG. 1). When the metal member 2 and the resin member 3 are pressurized when adjacently disposed, the metal member 2 and the resin member 3 can be easily joined by a solidification process described later.

  When the metal member 2 and the resin member 3 are disposed adjacent to each other, a laser absorption layer (not shown) may be provided on the surface of the metal member 2 or the surface of the resin member 3. As the laser absorbing layer, a pigment-based or dye-based laser absorbing material having an absorptivity with respect to the wavelength of the laser for bonding can be appropriately selected and used. If comprised in this way, the improvement of the conversion efficiency which converts the energy of the laser for joining into heat can be aimed at. In addition, the thickness of the laser absorption layer is preferably 10 μm or less in order to ensure the filling property of the concave portion 21 of the metal member 2. Further, a laser absorbing material may be blended in the resin member 3 as long as the resin member 3 satisfies the required laser transmittance.

Bonding process The bonding process is a process in which the resin member 3 is filled and bonded to the concave portion 21 of the metal member 2 by irradiating the bonding region BF of the metal member 2 with a laser from the resin member 3 side.

  Specifically, in the arranging step, the metal member 2 and the resin member 3 are pressed and brought into contact with each other, and then a bonding laser is irradiated toward the surface of the metal member 2.

Here, when the resin member 3 has laser transparency, the laser irradiation may be performed from the resin member 3 side or from the metal member 2 side. On the other hand, when the resin member 3 does not have laser transparency, the laser is irradiated from the metal member 2 side. As the type of laser for bonding, fiber laser, YAG laser, YVO ₄ laser, a semiconductor laser, carbon dioxide laser, an excimer laser can be selected.

  By irradiating the bonding region BF of the metal member 2 with the laser, the energy of the laser is converted into heat inside the metal member 2, and the surface temperature of the metal member 2 is increased. Thereby, the resin member 3 in the vicinity of the surface of the metal member 2 is melted, and the concave portion 21 is filled with the resin member 3. In the present embodiment, since the thin portion 23 is formed in the bonding region BF, even if the laser is irradiated to the bonding region BF of the metal member 2, heat in the laser irradiation direction (thickness direction of the metal member 2) is generated. Diffusion can be suppressed.

  Thereafter, the resin member 3 is solidified, whereby the bonded structure 1 in which the resin member 3 is bonded to the metal member 2 can be manufactured (see FIG. 3).

  Here, when irradiating the bonding region BF of the metal member 2 with a laser, the laser may be scanned in the bonding region BF, and the scanning may be performed a plurality of times along the same locus. In this case, since the laser scanning is performed a plurality of times along the same locus, the temperature of the metal member 2 rises, and the resin member 3 and the metal member 2 can be bonded more effectively.

  As described above, according to the method for manufacturing the bonded structure 1 of the present embodiment, since the thin member forming step for forming the thin member 23 in which the thickness of the metal member 2 is reduced is provided, the metal is formed in the subsequent bonding step. When the member 2 and the resin member 3 are joined, the metal member 2 and the resin member 3 can be joined with less laser energy while suppressing thermal diffusion.

-Experimental example of joint structure-
Next, an experimental example performed to confirm the effect of the first embodiment described above will be described with reference to FIG. FIG. 13 is an explanatory view schematically illustrating an example of a bonded structure.

  In this experimental example, bonded structures according to Examples 1-1 to 1-5 of the bonded structure corresponding to the first embodiment and Comparative Examples 1-1 and 1-2 were manufactured.

  The metal member used in each example and each comparative example is made of SUS304, and has a length of 100 mm, a width of 29 mm, and a thickness of 3 mm. The resin member is a PMMA resin, and has a length of 100 mm, a width of 25 mm, and a thickness of 3 mm. Moreover, the joining area | region BF of the metal member 2 and the resin member 3 was set as width 20mm and length 20mm (refer FIG. 13).

  Further, the laser used for joining the metal member 2 and the resin member 3 in the joining process is a semiconductor laser, the wavelength is 808 nm, the oscillation mode is continuous oscillation, the focal diameter is 4 mm, the scanning speed is 2 mm / sec, the metal member The contact pressure between 2 and the resin member 3 was set to 0.6 MPa.

  The evaluation of the bonding strength was performed using an electromechanical universal testing machine 5900 manufactured by Instron. Specifically, the test was performed at a tensile speed of 5 mm / min in the shear direction to evaluate the bonding strength. The evaluation results are shown in Table 1.

[Comparative Example 1-1]
In the joining structure of Comparative Example 1-1, the metal member and the resin member are joined in the joining region by setting the output of the semiconductor laser described above to 15 W in the joining step without providing the thin portion on the metal member. It was.

The bonding strength of this bonded structure was 5.6 MPa.
[Comparative Example 1-2]
In the joining structure of Comparative Example 1-2, the metal member and the resin member are joined in the joining region by setting the output of the semiconductor laser described above to 20 W in the joining process without providing the thin portion on the metal member. It was.

  The bonding strength of this bonded structure was 7.2 MPa.

[Example 1-1]
In the bonding structure 100 of Example 1-1, the bonding region BF ′ on the back surface of the metal member 200 has a hole having a length of 20 mm, a width of 20 mm, and a thickness of 2.5 mm (that is, an area substantially equal to the bonding region BF ′). In the joining process, the output of the semiconductor laser described above was set to 15 W, and the metal member 200 and the resin member 300 were joined in the joining region BF ′.

  The bonding strength of this bonded structure 100 was 11.8 MPa.

[Example 1-2]
In the bonding structure 100 of Example 1-2, the bonding region BF ′ on the back surface of the metal member 200 has a hole having a length of 20 mm, a width of 20 mm, and a thickness of 2.5 mm (that is, an area substantially equal to the bonding region BF ′). In the joining process, the output of the semiconductor laser described above was set to 20 W, and the metal member 200 and the resin member 300 were joined in the joining region BF ′.

  The bonding strength of this bonded structure 100 was 12.3 MPa.

[Example 1-3]
In the bonding structure 100 of Example 1-3, the bonding region BF ′ on the back surface of the metal member 200 has a hole having a length of 20 mm, a width of 20 mm, and a thickness of 2.5 mm (that is, an area substantially equal to the bonding region BF ′). Hole) to form a thin portion, a heat insulating material is provided in the hole, and in the bonding step, the output of the semiconductor laser described above is set to 15 W, and the metal member 200 and the resin member 300 are bonded to the bonding region BF ′. And joined.

  The bonding strength of this bonded structure 100 was 12.4 MPa.

[Example 1-4]
In the bonding structure 100 of Example 1-4, the bonding region BF ′ on the back surface of the metal member 200 has a hole having a length of 20 mm, a width of 20 mm, and a thickness of 2.5 mm (that is, an area substantially equal to the bonding region BF ′). Hole) is formed into a thin portion, and a reinforcing portion 24 is formed so as to connect diagonal lines to each other in the hole. In the joining process, the output of the semiconductor laser described above is set to 15 W, The metal member 200 and the resin member 300 were joined at the joining region BF ′.

  The bonding strength of the bonded structure 1 was 11.5 MPa.

[Example 1-5]
In the bonding structure 100 of Example 1-5, a hole having a length of 20 mm, a width of 20 mm, and a thickness of 2.5 mm is formed in the bonding region BF ′ on the back surface of the metal member 200 (that is, approximately the same area as the bonding region BF ′). Hole) is formed into a thin portion, and a reinforcing portion 24 formed so as to connect diagonal lines to each other is provided in the hole. In the joining process, the output of the semiconductor laser described above is set to 20 W, The metal member 200 and the resin member 300 were joined at the joining region BF ′.

  The bonding strength of the bonded structure 1 was 11.3 MPa.

  From the above evaluation results of the bonding strength, the bonding strengths of the bonded structures of Comparative Examples 1-1 and 1-2 in which the thin portion is not provided are those of Examples 1-1 to 1-5 in which the thin portion is provided. A result lower than the bonding strength of the bonded structure 100 was obtained.

  As a result, according to the bonded structure of the present embodiment, when the metal member 200 and the resin member 300 are bonded to each other by irradiating the bonding region BF ′ with a laser, a thin portion is formed in the bonding region BF ′. Therefore, thermal diffusion in the laser irradiation direction can be suppressed. Accordingly, the bonding strength between the metal member 200 and the resin member 300 can be improved while suppressing the laser output.

(Second Embodiment)
Hereinafter, the bonded structure 1 and the method for manufacturing the bonded structure 1 according to the second embodiment of the present invention will be described with reference to FIGS. FIG. 8 is a cross-sectional view of the second embodiment of the bonded structure, and FIGS. 9A to 9C are diagrams showing modifications of the second embodiment of the bonded structure.

  In addition, since this embodiment is different only in that the resin member 3 is accommodated in the thin portion 23 of the bonded structure 1 and bonded thereto, only the difference will be described below and the same components will be described. Are given the same reference numerals and their description is omitted.

−Composition structure−
First, the joint structure 1 according to the second embodiment of the present invention will be described.

  In the bonded structure 1 of the present embodiment, a thin portion 23 is provided by processing the surface side of the metal member 2 (see FIG. 8). In the illustrated example, the thin portion 23 is formed in the bonding region BF.

  A concave portion 21 is formed in the thin portion 23, and the metal member 2 and the resin member 3 are joined by filling the concave portion 21 with a resin member. In addition, although the protrusion part 22 which protrudes inside is formed in the concave-shaped part 21, the protrusion part 22 does not need to be formed.

  Note that the shape of the thin portion 23 is not limited to the shape of FIG. 8, and as shown in FIG. 9A, the surface of the bonding region BF is raised so that the central portion is not flush with the surface of the bonding region BF. 9B, a shape that is thinned as a convex shape in cross-sectional view, a shape that is thinned by processing the joint region BF on the surface of the metal member 2 through a trapezoidal shape in cross-sectional view, as shown in FIG. As described above, the bonding region BF on the surface of the metal member 2 may be formed in a thin shape by penetrating into a circular arc shape in a cross-sectional view.

  As shown in FIGS. 8 and 9A to 9C, the resin member 3 has a size that is substantially the same as the size of the bonding region BF (that is, a size that can be accommodated in the groove corresponding to the thin portion 23). However, it is not limited to this example. That is, the resin member 3 may have the same size as the metal member 2, and the surface of the resin member 3 may be bulged to the extent that it is accommodated in the groove corresponding to the thin portion 23.

-Manufacturing method of bonded structure-
Next, a method for manufacturing the bonded structure 1 according to the present embodiment will be described.

-Thin part formation process The surface of the metal member 2 is processed into the thin part 23 by the thin part formation process. In addition, the shape of the thin part 23 is not limited to the shape of FIG. 8, The shape shown to FIG.

-Recessed part formation process The recessed part 21 is formed in the thin part 23 of the metal member 2 by a recessed part formation process. At this time, when the laser is composed of a plurality of sub-pulses, the protruding portion 22 protruding inward can be formed on the inner peripheral surface of the concave portion 21.

-Arrangement process and joining process The surface of the metal member 2 and the resin member 3 are adjacently arranged by an arrangement process. Then, after the metal member 2 and the resin member 3 are pressed and brought into contact with each other, a laser for joining is irradiated toward the surface of the metal member 2. Thereby, the resin member 3 in the vicinity of the surface of the metal member 2 is melted, and the concave portion 21 is filled with the resin member 3.

  Thereafter, the resin member 3 is solidified, whereby the bonded structure 1 in which the resin member 3 is bonded to the metal member 2 can be manufactured.

  As described above, since the thin portion 23 in which the thickness of the metal member 2 is reduced is formed also by the method for manufacturing the bonded structure 1 of the present embodiment, when the metal member 2 and the resin member 3 are bonded together. In addition, the metal member 2 and the resin member 3 can be joined with a small amount of laser energy.

(Third embodiment)
Hereinafter, the joint structure of the third embodiment of the present invention and the method for manufacturing the joint structure will be described with reference to FIGS.

  FIG. 10 is a cross-sectional view of the third embodiment of the joint structure, FIG. 11 is a cross-sectional view of a modification of the third embodiment of the joint structure, and FIG. 12 is another view of the third embodiment of the joint structure. It is a perspective view of a modification.

  In the present embodiment, since only the structure of the thin portion 23 of the bonded structure 1 is different, only the difference will be described below, and the same components will be denoted by the same reference numerals and the description thereof will be given. Omitted.

−Composition structure−
First, the joint structure 1 according to the third embodiment of the present invention will be described.

  In the bonding structure 1 of the present embodiment, a thin portion 23 is formed by forming a slit on the back surface of the metal member 2 (see FIG. 10).

  In the illustrated example, two thin portions 23 are formed in a region including at least the adjacent region NF. Note that the number of thin portions 23 may be one, or may be three or more. Further, the thin portion 23 may be formed in the bonding region BF over a region including the adjacent region NF.

  The concave portion 21 is formed in the bonding region BF on the surface of the metal member 2. By filling the concave portion 21 with the resin member 3, the metal member 2 and the resin member 3 are joined. In addition, although the protrusion part 22 which protrudes inside is formed in the concave-shaped part 21, the protrusion part 22 does not need to be formed.

  The thin portion 23 may be provided with a heat insulating material 25 (see FIG. 11) or a reinforcing portion 24 that reinforces the metal member 2 (see FIG. 12). Moreover, the reinforcement part 24 may be arrange | positioned in parallel so that the gap | interval of a slit may be tied, and may be arrange | positioned diagonally in the slit.

-Manufacturing method of bonded structure-
Next, a method for manufacturing the bonded structure 1 according to the present embodiment will be described.

-Thin part formation process A slit is formed in the back surface of the metal member 2 by the thin part formation process, and it is set as the thin part 23. FIG. Note that a heat insulating material 25 may be formed on the thin portion 23 (see FIG. 11), or a reinforcing portion 24 that reinforces the metal member 2 may be formed.

-Concave part formation process The concave part 21 is formed in the joining area | region BF in the surface of the metal member 2 by a concave part formation process. At this time, when the laser is composed of a plurality of sub-pulses, the protruding portion 22 protruding inward can be formed on the inner peripheral surface of the concave portion 21.

-Arrangement process and joining process The surface of the metal member 2 and the resin member 3 are adjacently arranged by an arrangement process. Then, after the metal member 2 and the resin member 3 are pressed and brought into contact with each other, a joining laser is irradiated toward the surface of the metal member 2 in a joining process.

  By irradiating the bonding region BF of the metal member 2 with the laser, the resin member 3 in the vicinity of the surface of the metal member 2 is melted, and the resin member 3 is filled in the concave portion 21.

  In the present embodiment, since the thin portion 23 is formed in a region including at least the adjacent region NF, thermal diffusion from the junction region BF to the outside via the thin portion 23 even if the junction region BF is irradiated with laser. Can be suppressed. That is, by forming the thin portion 23, the laser energy can be retained in the bonding region BF.

  Thereafter, the resin member 3 is solidified, whereby the bonded structure 1 in which the resin member 3 is bonded to the metal member 2 can be manufactured.

  As described above, since the thin portion 23 in which the thickness of the metal member 2 is reduced is formed also by the method for manufacturing the bonded structure 1 of the present embodiment, when the metal member 2 and the resin member 3 are bonded together. In addition, the metal member 2 and the resin member 3 can be joined with a small amount of laser energy.

-Experimental example of joint structure-
Next, an experimental example performed for confirming the effect of the above-described third embodiment will be described with reference to FIG. FIG. 14 is an explanatory diagram schematically illustrating an example of the bonded structure according to the third embodiment.

  In this experimental example, bonded structures according to Examples 2-1 to 2-5 of the bonded structure corresponding to the third embodiment and Comparative Examples 2-1 and 2-2 were manufactured.

  The metal member 2 used in each example and each comparative example is made of SUS304, and has a length of 100 mm, a width of 29 mm, and a thickness of 3 mm. The resin member 3 is a PMMA resin and has a length of 100 mm, a width of 25 mm, and a thickness of 3 mm. Moreover, the joining area | region BF of the metal member 2 and the resin member 3 was set as width 20mm and length 20mm.

  Further, the laser used for joining the metal member 2 and the resin member 3 in the joining process is a semiconductor laser, the wavelength is 808 nm, the oscillation mode is continuous oscillation, the focal diameter is 4 mm, the scanning speed is 2 mm / sec, The contact pressure with the resin member was set to 0.6 MPa.

  The evaluation of the bonding strength was performed using an electromechanical universal testing machine 5900 manufactured by Instron. Specifically, the test was performed at a tensile speed of 5 mm / min in the shear direction to evaluate the bonding strength. The evaluation results are shown in Table 2.

[Comparative Example 2-1]
In the joining structure of Comparative Example 2-1, the metal member and the resin member are joined in the joining region by setting the output of the above-described semiconductor laser to 15 W in the joining step without providing a thin portion in the metal member. It was.

  The bonding strength of this bonded structure was 5.6 MPa.

[Comparative Example 2-2]
In the joining structure of Comparative Example 2-2, the metal member and the resin member are joined at the joining region in the joining step without setting the thin portion on the metal member, and setting the output of the semiconductor laser described above to 20 W. It was.

  The bonding strength of this bonded structure was 7.2 MPa.

[Example 2-1]
The bonding structure 100 of Example 2-1 is thin by forming a slit having a width of 0.2 mm and a depth of 2.5 mm in a region (adjacent region NF ′) surrounding the bonding region BF ′ on the back surface of the metal member 200. In the joining process, the output of the semiconductor laser described above was set to 15 W, and the metal member 200 and the resin member 300 were joined in the joining region BF ′.

  The bonding strength of the bonded structure 1 was 10.5 MPa.

[Example 2-2]
The bonding structure 100 of Example 2-2 is thin by forming a slit having a width of 0.2 mm and a depth of 2.5 mm in a region (adjacent region NF ′) surrounding the bonding region BF ′ on the back surface of the metal member 200. In the joining step, the output of the semiconductor laser described above was set to 20 W, and the metal member 200 and the resin member 300 were joined in the joining region BF ′.

  The bonding strength of the bonded structure 1 was 11.2 MPa.

[Example 2-3]
The bonding structure 100 of Example 2-3 is thin by forming a slit having a width of 0.2 mm and a depth of 2.5 mm in a region (adjacent region NF ′) surrounding the bonding region BF ′ on the back surface of the metal member 200. In addition, in the joining process, the output of the semiconductor laser described above was set to 15 W, and the metal member 200 and the resin member 300 were joined in the joining region BF ′.

  The bonding strength of the bonded structure 1 was 11.4 MPa.

[Example 2-4]
The bonding structure 100 of Example 2-4 is thin by forming a slit having a width of 0.2 mm and a depth of 2.5 mm in a region (adjacent region NF ′) surrounding the bonding region BF ′ on the back surface of the metal member 200. In addition, in the joining process, the output of the semiconductor laser described above is set to 15 W, and the metal member 200 and the resin member 300 are joined at the joining region BF ′. It was made to join.

  The bonding strength of the bonded structure 1 was 10.4 MPa.

[Example 2-5]
The bonding structure 100 of Example 2-5 is thin by forming a slit having a width of 0.2 mm and a depth of 2.5 mm in a region (adjacent region NF ′) surrounding the bonding region BF ′ on the back surface of the metal member 200. In addition, in the joining process, the output of the semiconductor laser described above is set to 20 W, and the metal member 200 and the resin member 300 are joined in the joining region BF ′. It was made to join.

  The bonding strength of the bonded structure 1 was 10.7 MPa.

  From the above evaluation results, the bonding strengths of the bonded structures of Comparative Examples 2-1 and 2-2 that are not provided with the thin portion are the bonded structures of Examples 2-1 to 2-5 that are provided with the thin portion 23. A result lower than the bonding strength of the body 1 was obtained.

  Thereby, according to the joining structure 1 of this embodiment, since the thin part 23 is formed in the area | region including the adjacent area | region NF at least, the joining area | region BF is irradiated with a laser, and the metal member 2 and the resin member When 3 is bonded, it is possible to suppress thermal diffusion from the bonding region BF to the outside through the thin portion 23. Thereby, the energy of the laser can be confined in the bonding region BF with a small amount of laser energy, and the metal member 2 and the resin member 3 can be bonded.

  The above-described embodiments and examples of the present invention are all examples of the present invention, and are not of a nature that limits the technical scope of the present invention.

DESCRIPTION OF SYMBOLS 1,100 Joining structure 2,200 Metal member 21 Recessed part 22 Protruding part 23 Thin part 24 Reinforcement part 25 Heat insulating material 3,300 Resin member BF, BF 'Joining area | region NF, NF' Adjacent area | region

Claims (9)

A joining structure having a joining region in which a metal member and a resin member are joined,
In the joining region of the metal member, a concave portion having an opening on the surface of the metal member is formed, and the concave portion of the metal member is filled with the resin member,
The metal member is provided with a thin portion where the thickness of the metal member is reduced in a region including the bonding region and an adjacent region adjacent to the bonding region. Structure. A joining structure according to claim 1, wherein
The thin structure is formed in the bonding region. A joining structure according to claim 1, wherein
The thin structure is formed in a region including at least the adjacent region. It is a junction structure given in any 1 paragraph of Claims 1-3,
The thin structure is provided with a heat insulating material. It is the joining structure object given in any 1 paragraph of Claims 1-4,
The thin structure is provided with a reinforcing portion for reinforcing the metal member. It is the joining structure object given in any 1 paragraph of Claims 1-5,
A joint structure having a projecting portion projecting inward is formed on an inner peripheral surface of the concave portion. A method for manufacturing a bonded structure having a bonding region in which a metal member and a resin member are bonded,
In the metal member, a thin part forming step of forming a thin part in which the thickness of the metal member is reduced in a region including the joining region and an adjacent region adjacent to the joining region;
A recessed portion forming step of forming a recessed portion having an opening in the joining region of the surface of the metal member;
An arranging step of arranging the surface of the metal member and the resin member adjacent to each other;
A joining step of filling and joining the resin member to the concave portion of the metal member by irradiating the joining region of the metal member with a laser from the resin member side;
The manufacturing method of the joining structure characterized by comprising. It is a manufacturing method of the joined structure according to claim 7,
In the joining step, when irradiating the joining region of the metal member with a laser, the laser is scanned in the joining region, and the scanning is performed a plurality of times on the same locus. . A method for manufacturing a joined structure according to claim 7 or 8,
In the concave portion forming step, the concave portion is formed by irradiating a laser in which one pulse includes a plurality of subpulses.

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