JP6098527B2 - Method of joining metal member and resin member - Google Patents

Description

  The present invention relates to a method for joining a metal member and a resin member, and a joining member set including a metal member and a resin member used in the method.

  Conventionally, weight reduction has been demanded in the fields of automobiles, railway vehicles, aircraft, and the like. For example, in the field of automobiles, the use of high-tensile materials has made it possible to reduce the thickness of steel sheets, or aluminum alloy materials have been used as substitutes for steel materials, and the use of resin materials has also advanced. In such a field, development of a joining technique between a metal member and a resin member is important not only from the viewpoint of weight reduction, but also from the viewpoint of realizing an increase in strength, rigidity, and productivity of the joining member. So far, a so-called friction stir welding (FSW) method has been proposed as a method for joining a metal member and a resin member. As shown in FIG. 16, the friction stir welding method is a method in which a metal member 211 and a resin member 212 are overlapped, and the rotary tool 216 is rotated and pressed against the metal member 211 to generate frictional heat. In this method, the resin member 212 is softened and the metal member 211 and the resin member 212 are joined.

  In such a friction stir welding method, for example, a technique (Patent Document 1) is disclosed in which the shape and push-in amount of the rotary tool are set within a specific range from the viewpoint of joining strength and simple joining.

JP 2010-158885 A

  However, in the conventional friction stir welding method, as shown in FIGS. 17 (A) and 17 (B), since the joining surface 212a of the resin member 212 with the metal member is a flat surface, as shown in FIG. 17 (C). Part of the resin softened by frictional heat between the rotary tool 216 and the metal member 211 leaks from between the metal member 211 and the resin member 212 at the end face, and a so-called burr 220 is formed after cooling. There is. Such a burr not only deteriorates the appearance of the joined body, but also causes work efficiency to deteriorate when the joined body is assembled with other members.

  Particularly, in order to further increase the bonding strength between the metal member 211 and the resin member 212, when the amount of pressing of the rotary tool 216 into the metal member 211 is increased, and the interface temperature between the metal member and the resin member is increased. In this case, the problem of burr formation may become prominent.

  An object of this invention is to provide the joining method of the metal member and resin member which prevent formation of a burr | flash, and the resin member used in this method.

The present invention
It is a hot-pressure bonding method in which a metal member and a resin member are overlapped, the resin member is softened by applying heat and pressure from the metal member side, and the metal member and the resin member are bonded.
The present invention relates to a method for joining a metal member and a resin member, characterized in that a resin member having a retaining groove for allowing a resin softened at the time of joining to flow on a joining surface with the metal member is used as the resin member.

The present invention also provides
In the above bonding method, the hot-pressure bonding method is a friction stir welding method,
The friction stir welding method relates to a joining method including the following steps:
A first step of superimposing the metal member and the resin member; and while rotating the rotary tool, the metal member is pressed against the metal member to generate frictional heat, and the frictional heat softens the resin member to form the metal member and the resin member. Second step of joining.

  The present invention also relates to a resin member used in the joining method.

  According to the joining method of the present invention, since the resin member has the accumulation groove on the joining surface with the metal member, the resin softened at the time of joining can be caused to flow into the accumulation groove. For this reason, the outflow of the softened resin from between the metal member and the resin member is avoided, and the formation of burrs is sufficiently prevented. Further, by stabilizing the flow state of the molten resin inside the accumulation groove, variation in bonding strength is reduced.

It is a schematic diagram which shows an example of a part of friction stir welding apparatus suitable for the joining method of the metal member and resin member concerning this invention. (A) is a general | schematic sketch which shows the joining surface with the metal member in the resin member of the 1st embodiment used for the joining method of this invention, (B) is the AA cross section of the resin member in (A). It is a schematic sectional drawing when it sees in the arrow direction, (C) is a schematic sectional drawing when the joining method of this invention is implemented using the resin member of (B). (A) is a general | schematic sketch which shows the joining surface with the metal member in the resin member of the 2nd embodiment used for the joining method of this invention, (B) is the AA cross section of the resin member in (A). It is a schematic sectional drawing when it sees in the arrow direction, (C) is a schematic sectional drawing when the joining method of this invention is implemented using the resin member of (B). (A) is a general | schematic sketch which shows the joining surface with the metal member in the resin member of the 3rd embodiment used for the joining method of this invention, (B) is the AA cross section of the resin member in (A). It is a schematic sectional drawing when it sees in the arrow direction, (C) is a schematic sectional drawing when the joining method of this invention is implemented using the resin member of (B). (A) is a general | schematic sketch which shows the joining surface with the metal member in the resin member of the 4th embodiment used for the joining method of this invention, (B) is the AA cross section of the resin member in (A). It is a schematic sectional drawing when it sees in the arrow direction, (C) is a schematic sectional drawing when the joining method of this invention is implemented using the resin member of (B). (A) is a general | schematic sketch which shows the joining surface with the metal member in the resin member of the 5th embodiment used for the joining method of this invention, (B) is the AA cross section of the resin member in (A). It is a schematic sectional drawing when it sees in the arrow direction, (C) is a schematic sectional drawing when the joining method of this invention is implemented using the resin member of (B), (D) is the obtained joining It is a general | schematic cross-sectional sketch when a body is seen in the B direction of (C). The (A) is a general | schematic sketch which shows the joining surface with the metal member in the resin member of the 6th embodiment used for the joining method of this invention, (B) is the AA cross section of the resin member in (A). It is a schematic sectional drawing when it sees in the arrow direction, (C) is a schematic sectional drawing when the joining method of this invention is implemented using the resin member of (B). (A) is a general | schematic sketch which shows the joining surface with the resin member in the metal member of the 1st embodiment used for the joining method of this invention, (B) is the AA cross section of the metal member in (A). It is a schematic sectional drawing when it sees in the arrow direction, (C) is a schematic sectional drawing when the joining method of this invention is implemented using the metallic member of (B). (A) is a general | schematic sketch which shows the joining surface with the resin member in the metal member of the 2nd embodiment used for the joining method of this invention, (B) is the AA cross section of the metal member in (A). It is a schematic sectional drawing when it sees in the arrow direction, (C) is a schematic sectional drawing when the joining method of this invention is implemented using the metallic member of (B). (A) is a general | schematic sketch which shows the joining surface with the resin member in the metal member of the 3rd embodiment used for the joining method of this invention, (B) is the AA cross section of the metal member in (A). It is a schematic cross-sectional sketch when viewed in the direction of the arrow, and (C) is when the joining method of the present invention is carried out using the metal member of FIG. 10 (B) and the resin members of FIGS. 2 (A) to (C). FIG. It is an enlarged view of the front-end | tip part of an example of the rotary tool used for the joining method of this invention. It is sectional drawing for demonstrating the preheating process in the joining method of this invention. It is sectional drawing for demonstrating the pushing stirring process in the joining method of this invention, a stirring maintenance process, and a holding process. It is sectional drawing of the conjugate | zygote obtained by the joining method of this invention. (A) is a schematic sketch which shows the resin member used in Example 1, (B) is a schematic cross-sectional view when the AA cross section of the resin member in (A) is seen in the arrow direction. (A) is a schematic sketch which shows the resin member used in Example 2, (B) is a schematic cross-sectional sketch when the AA cross section of the resin member in (A) is seen in the arrow direction. (A) is a schematic sketch which shows the resin member used in Example 3, (B) is a schematic cross-sectional sketch when the AA cross section of the resin member in (A) is seen in the arrow direction. (A) is a schematic sketch showing the resin member used in Example 4, (B) is a schematic cross-sectional view when the AA cross section of the resin member in (A) is seen in the direction of the arrow, C) is a schematic cross-sectional sketch when a joined body obtained using the resin member of (B) is viewed in the B direction of (B). It is a schematic diagram for demonstrating the joining method of the metal member and resin member in a prior art. (A) is a schematic sketch showing a resin member used in a conventional joining method, (B) is a schematic cross sectional view when the AA cross section of the resin member in (A) is seen in the direction of the arrow, (C) is a schematic sectional drawing when the conventional joining method is implemented using the resin member of (B).

  The bonding method of the present invention softens the resin member by superimposing the metal member and the resin member and applying heat and pressure from the metal member side, preferably locally from the metal member side. This is a hot-pressure joining method for joining a metal member and a resin member. The joining method employed in the joining method of the present invention is not particularly limited as long as it is a method of heating while applying pressure. For example, a friction stir welding method, a laser heating joining method, a resistance heating joining method (electric heating) Bonding method), induction heating bonding method, ultrasonic heating bonding method and the like. Among them, the friction stir welding method has the largest applied pressure, and thus the occurrence of burrs is remarkable. However, the occurrence of such burrs can be effectively prevented by the joining method of the present invention. For this reason, the friction stir welding method is preferably employed.

As described in detail later, the friction stir welding method uses friction heat generated by pressing against a metal member while rotating a rotary tool in a state where the joining member sets are overlapped and restrained. It is a method of joining. Hereinafter, a combination of a metal member and a resin member before joining to be joined is referred to as a “joining member set”.
The laser heating bonding method is a method of bonding using heat generated by irradiating a metal member with a laser in a state where the bonding member sets are overlapped and restrained. As the laser, a YAG laser, a fiber laser, a semiconductor laser, or the like is used.
The resistance heating bonding method is a method of bonding using heat generated by flowing a current directly to a metal member in a state where the bonding member sets are superimposed and restrained.
The induction heating bonding method is a method in which an induction current is generated in a metal member by an electromagnetic induction action in a state where the bonding member sets are superposed and restrained, and the heat generated by the current is used for bonding.
The ultrasonic heating bonding method is a method in which ultrasonic vibration is generated in a metal member while applying pressure from the metal member side in a state where the bonding member set is superposed and restrained, and frictional heat between the metal member and the resin member generated by the vibration is generated. It is the method of joining using.

  Hereinafter, the joining method of the present invention that employs the friction stir welding method will be described with reference to the drawings. However, as long as the resin member described later is used, the effects of the present invention can be obtained even if other joining methods described above are used. Is clear.

  First, FIG. 1 is a diagram schematically showing an example of a part of a friction stir welding apparatus suitable for carrying out the joining method of the present invention. A friction stir welding apparatus 1 shown in FIG. 1 is configured as a device that friction stir welds a metal member 11 and a resin member 12, and includes a cylindrical rotary tool 16. As shown in the figure, the rotary tool 16 is applied to the workpiece 10 with the metal member 11 on the top and the resin member 12 on the bottom, by a drive source (not shown) as indicated by an arrow A1. While rotating around the central axis X (see FIG. 11A), the metal member 11 is pressed downward in the pressing region P (scheduled pressing region) as indicated by an arrow A2. Friction heat is generated by the pressing of the rotary tool 16, and this frictional heat is conducted to the resin member 12 to soften and melt the resin member 12, and as a result, the metal member 11 and the resin member 12 are joined.

  Below the rotary tool 16, a cylindrical receiving member 17 having the same diameter as the rotary tool 16 or a larger diameter than the rotary tool 16 is arranged coaxially with the rotary tool 16. The receiving member 17 is moved upward with respect to the work 10 as shown by an arrow A3 by a driving source (not shown). The upper end surface of the receiving member 17 abuts on the lower surface of the workpiece 10 (more specifically, the lower surface of the resin member 12) by the time the rotating tool 16 starts pressing the workpiece 10 at the latest. The support 17 sandwiches the workpiece 10 between the rotary tool 16 and supports the workpiece 10 from below against the pressing force during a pressing period by the rotary tool 16, that is, during friction stir welding. Note that the receiving tool 17 does not necessarily have to be moved in the direction of the arrow A3, and a method of moving the rotary tool 16 in the direction of the arrow A2 after placing the workpiece 10 on the receiving tool 17 can also be adopted.

  The friction stir welding apparatus 1 is attached to a drive control device (not shown) composed of an articulated robot or the like. The coordinate positions of the rotary tool 16 and the receiving tool 17, the rotational speed (rpm) of the rotary tool 16, the pressure (N), the pressurization time (second), and the like are appropriately controlled by the drive control device. Although not shown in FIG. 1, the friction stir welding apparatus 1 uses a spacer, a clamp, or the like for fixing the work 10 in advance and preventing the metal member 11 from floating when the rotary tool 16 is pressed. A jig is provided.

(1) Joining member set The joining member set consisting of the metal member and the resin member used in the joining method of the present invention is on the joining surface of the resin member with the metal member and / or the joining surface of the metal member with the resin member. A reservoir groove is formed to allow a softening resin to flow during bonding. That is, as the resin member, a resin member having a retention groove for allowing a resin softened at the time of bonding to flow into the bonding surface with the metal member is used and / or the bonding surface with the resin member as the metal member The metal member which has the accumulation groove for making the resin softened at the time of joining flow in is used. Hereinafter, unless otherwise specified, the case where the resin member has a collecting groove on the bonding surface with the metal member will be described. However, the resin softened between the metal member and the resin member at the time of bonding can be collected as long as the resin can flow into the collecting groove. The groove may be formed on only one of the bonding surface of the resin member with the metal member, the bonding surface of the metal member with the resin member, or may be formed on both of them.

(1.1) Resin member The resin member has a retention groove on the surface joined to the metal member. The reservoir groove is a recess for allowing a resin that is softened and melted during bonding to flow in and accommodate. The embodiment of such a resin member used in the present invention will be described in detail with reference to FIGS. 2 to 7 are schematic views of the resin member 12 in which the shape of the accumulation groove 120 and / or the presence or absence of the convex portion 122, the guide groove 125A, and the guide hole 125B described later are different. 2-7, (A) is a schematic sketch which shows the joining surface with the metal member in the resin member of each embodiment, (B) is the AA cross section of the resin member in (A) in the arrow direction. It is a schematic sectional drawing when it sees, (C) is a schematic sectional drawing when the joining method of this invention is implemented using the resin member of (B). FIG. 6D is a schematic cross-sectional sketch when the obtained bonded body is viewed in the B direction of FIG. 2 to 7 and other drawings (FIGS. 1, 8 to 10, FIGS. 11A to 11D, and FIGS. 12 to 15), members, regions, dimensions, and the like indicated by the same reference numerals are different in shape of the members. Except for this, the same members, regions, and dimensions are used.

  In the present invention, the resin member 12 having the retaining groove 120 on the bonding surface 12a is formed at the time of bonding as shown in FIGS. 2 (C), 3 (C), 4 (C), 5 (C), and 6 (C). ) And FIG. 7C, the softened resin 121 can be caused to flow into the accumulation groove 120, so that the formation of burrs can be sufficiently prevented.

  The joining surface 12a of the resin member 12 and the metal member 11 having the accumulation groove 120 means a surface region of the resin member 12 that comes into contact with the metal member 11 when the resin member 12 is overlapped with the metal member 11 for joining. .

  The overall shape of the accumulation groove 120 on the joining surface 12a is not particularly limited as long as the softened resin can flow between the metal member 11 and the resin member 12 during joining. For example, the reservoir groove 120 is formed on the bonding surface 12a as shown in FIGS. 2A, 3A, 4A, 5A, 6A, and 7A. It may be formed in a ring shape, may be formed in a C shape, or may be formed in a linear shape or a dot shape. From the viewpoint of further sufficiently preventing the formation of burrs by efficiently accommodating the softening resin in the pool groove, the pool groove 120 is preferably formed in an annular shape on the bonding surface 12a, more preferably from the same viewpoint. Is that heat and pressure are locally applied within the inner region 126 of the annular reservoir groove 120. The inner region 126 of the annular reservoir groove 120 is an island region defined by the annular reservoir groove 120. The fact that heat and pressure are locally applied in such an inner region 126 means that the region P on the bonding surface 12a corresponding to the region immediately below the pressing region P (see FIG. 1) of the rotary tool 16 on the metal member 11. The resin member 12 is overlapped with the metal member 11 so that '(the hatched area indicated by a broken line; see FIGS. 2 to 7) is located in the inner area 126, and a rotating tool is applied to the metal member 11. It means to press.

  Of the specific overall shape of the pool groove 120 on the bonding surface 12a, the preferred ring shape is not particularly limited, and for example, FIG. 2 (A), FIG. 4 (A), FIG. 5 (A), A substantially circular shape as shown in FIGS. 6A and 7A may be used, or a substantially rectangular shape as shown in FIG. 3A may be used. Preferably it is a substantially circular shape. When the overall shape of the accumulation groove 120 is a substantially circular shape, the substantially circular shape is a region for locally applying heat and pressure (that is, a hatched region) on the bonding surface 12a from the viewpoint of more sufficiently preventing the formation of burrs. It is preferably a substantially circular shape centered on P ′). That is, it is preferable that heat and pressure are locally applied to the substantial center of the substantially circular shape.

  The cross-sectional shape of the reservoir groove 120 is not particularly limited as long as it can accommodate the resin softened at the time of joining. For example, FIG. 2 (B), FIG. 3 (B), FIG. 5 (B), FIG. Also, it may be a substantially square shape as shown in FIG. 7B, a substantially semicircular shape as shown in FIG. 4B, or a substantially triangular shape.

  The resin member 12 preferably has a convex portion 122 (see, for example, FIG. 5) on the bonding surface 12a from the viewpoint of accelerating the flow of the molten resin during bonding and stably achieving high-strength bonding. In particular, when the overall shape of the accumulation groove 120 on the bonding surface 12a is an annular shape, the resin member 12 may have a convex portion 122 in the inner region 126 of the annular accumulation groove 120 from the same viewpoint as described above. preferable. Most preferably, as shown in FIGS. 5 (A) and 5 (B), it has a convex portion 122 in the locally applied region of heat and pressure (that is, the hatched region P ′) in the inner region 126. When the resin member 12 has the convex portion 122 in the inner region 126 of the annular reservoir groove 120, the convex portion may be provided over the entire area in the inner region 126 of the annular reservoir groove 120.

The dimensions, such as the depth, width, and length, of the reservoir groove 120 ensure a volume that can accommodate the softening resin that forms burrs when the resin member 12 does not have the reservoir groove, and the resin member 12 itself. As long as the strength of is secured, there is no particular limitation. The volume V (mm ³ ) of the accumulation groove 120 is usually the indentation volume v1 (mm ³ ) of the rotary tool 16 against the metal member 11 and the volume v2 (mm ³ ) of the convex portion 122 (v2 = when there is no convex portion). 0) and is usually v1 + v2− (v1 + v2) × 2.0 mm ³ , preferably v1 + v2− (v1 + v2) × 1.4 mm ³ . The indentation volume v1 (mm ³ ) of the rotary tool 16 with respect to the metal member 11 is a volume corresponding to the tool trace volume in the obtained joined body, for example, a volume in a region indicated by a broken line in FIG. 11D.

Specifically, the depth t1 of the accumulation groove 120 is normally 0.05T to 0.7T, preferably 0.1T to 0.5T, where the thickness of the resin member 12 is T (mm). is there. At the same time, the width w1 of the accumulation groove 120 is usually 0.5T to 1.5T, preferably 0.6T to 1.2T.
The height h1 of the convex part 122 is not particularly limited.

  The resin member 12 may further include a guide groove and / or a guide hole for guiding the softened resin flowing into the accumulation groove 120 during joining to the outside of the system.

  6A to 6D, the guide groove is indicated by 125A, for example, and is continuously formed in the pool groove 120 on the bonding surface 12a of the resin member 12 with the metal member 11. The guide groove 125A guides the softened resin 121 that flows into the accumulation groove 120 during joining from the end surface to the outside of the system. The cross-sectional shape of the guide groove 125A is not particularly limited, and may be, for example, a substantially semicircular shape, a substantially square shape, a substantially triangular shape, or the like. The depth t2 and the width w2 of the guide groove 125A are not particularly limited as long as the softening resin 121 can be guided out of the system.

  The guide hole is indicated by 125B in FIGS. 7A to 7C, for example, and is formed through the resin member 12 in the thickness direction. The guide hole 125B guides the softened resin 121 that flows into the accumulation groove 120 at the time of joining, from the surface opposite to the joining surface 12a to the outside of the system. The cross-sectional shape of the guide hole 125B is not particularly limited, and may be, for example, a substantially circular shape, a substantially square shape, or a substantially triangular shape. The width (in the case of a substantially circular shape) r1 and the length s1 of the guide hole 125B are not particularly limited as long as the softening resin 121 can be guided out of the system.

  Since the resin member 12 has the guide groove 125A and / or the guide hole 125B as described above, the inflow of the softened resin 121 in the pool groove 120 can be detected and inspected. That is, in the joined body in which the presence of the resin is detected in the guide groove 125A and the guide hole 125B by observation from the outside, at least the softened resin flows into the pool groove 120. Good bonding can be guaranteed. On the other hand, the joined body in which the resin cannot be detected in the guide groove 125A and the guide hole 125B by observation from the outside is good because the resin softening between the metal member 11 and the resin member 12 may be insufficient. Bonding cannot be guaranteed. Further, even when the molten resin is discharged from the guide groove 125A and / or the guide hole 125B and burrs are generated, the amount is small compared to the burrs that can be generated when the pool groove 120 is not provided, and the removal is easy.

  As described above, the resin member 12 has been described as having a substantially flat plate shape as a whole, but is not limited thereto, and is a surface that comes into contact with the metal member 11 when superposed on the metal member 11 for bonding. As long as it has the joining surface 12a as described above, it may have any shape.

  Although the thickness T of the part which has the joining surface 12a in a resin member is 2-5 mm normally, it is not limited to this.

  The resin member 12 can be manufactured by any known method. For example, the resin member 12 can be molded by subjecting a polymer composition containing a thermoplastic polymer and other desired additives to a melt molding method in which the thermoplastic polymer melts. The melt molding method includes all molding methods in which a resin member that has been heated and melted or softened is subsequently cooled and solidified to obtain a part shape. For example, an injection molding method, a press molding method, an extrusion molding method, a drawing method, and the like. Examples thereof include a molding method and an autoclave molding method.

  The retaining groove 120, the convex part 122, the guide groove 125A and the guide hole 125B of the resin member 12 can be formed, for example, by transferring a molding surface of a mold used in the molding method. In particular, the accumulation groove 120, the guide groove 125A, and the guide hole 125B can be formed by cutting the planar surface of the resin member 12 using a cutting tool or the like.

  The resin member 12 is preferably formed by an injection molding method, and the pool groove 120 is preferably formed by transferring a molding surface of a mold used in the injection molding method.

As the thermoplastic polymer constituting the resin member 12, any polymer having thermoplasticity can be used. Of these, thermoplastic polymers used in the field of automobiles are preferably used. Specific examples of such thermoplastic polymers include, for example, the following polymers and mixtures thereof:
Polyolefin resins such as polyethylene and polypropylene;
Polyester resins such as polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polytrimethylene terephthalate (PTT), polylactic acid (PLA));
Polyacrylate resins such as polymethyl methacrylate resin (PMMA);
Polyether resins such as polyether ether ketone (PEEK) and polyphenylene ether (PPE);
Polyacetal (POM);
Polyphenylene sulfide (PPS);
PA6, PA66, PA11, PA12, PA6T, PA9T, MXD6 and other polyamide-based resins (PA);
Polycarbonate resin (PC);
Polyurethane resin;
A fluoropolymer resin; and a liquid crystal polymer (LCP).

  Examples of the additive contained in the resin member 12 include fillers such as talc, and reinforcing fibers such as carbon fibers and glass fibers.

(1.2) Metal member Although the metal member 11 has a substantially flat plate shape as a whole in FIG. 1 and the like, the metal member 11 is not limited to this, and is a portion overlapped with the resin member 12 for bonding. As long as only has at least a substantially flat plate shape, it may have any shape.

  The thickness (K) of the substantially flat plate-shaped portion that overlaps the resin member 12 in the metal member 11 is usually 0.5 to 4 mm, but is not limited thereto.

As the metal constituting the metal member 11, any metal having a melting point higher than that of the thermoplastic polymer constituting the resin member 12 can be used. Among these, the following metals and alloys used in the automotive field are preferably used:
aluminum;
Aluminum alloys such as 5000 series and 6000 series;
steel;
Magnesium and its alloys;
Titanium and its alloys.

  The metal member 11 has the reservoir groove 120, the guide groove 125A, and / or the guide hole 125B instead of the resin member 12 having the reservoir groove 120, or instead of having the guide groove 125A and / or the guide hole 125B. Also good. The reservoir groove 120 only needs to be formed on at least one of the bonding surface of the resin member with the metal member or the bonding surface of the metal member with the resin member. When the guide groove 125A and / or the guide hole 125B is formed, the guide groove 125A and / or the guide hole 125B is formed on at least one of the bonding surface of the resin member with the metal member or the bonding surface of the metal member with the resin member. It only has to be done. The guide groove 125 </ b> A of the metal member 11 is formed continuously with the pool groove 120 of the metal member 11 and / or the resin member 12 on the bonding surface 11 a of the metal member 11 with the resin member 12. The guide hole 125 </ b> B of the metal member 11 is formed so as to penetrate in the thickness direction of the metal member 11. The joining surface 11a between the metal member 11 and the resin member 12 having the accumulation groove 120 means a surface area of the metal member 11 that comes into contact with the resin member 12 when the metal member 11 is overlapped with the resin member 12 for joining. .

  The embodiment of the metal member in the case where the metal member 11 has the accumulation groove 120 on the bonding surface 11a with the resin member is shown in FIGS. 8 to 9 are schematic views of the metal member 11 with or without the guide groove 125A. 8 to 9, (A) is a schematic sketch showing a bonding surface 11a with the resin member in the metal member 11 of each embodiment, and (B) is an arrow AA cross section of the resin member in (A) It is a schematic sectional drawing when it sees in a direction, (C) is a schematic sectional drawing when the joining method of this invention is implemented using the metallic member of (B). 8 (C) and 9 (C), the resin member 12 does not have the accumulation groove 120, the guide groove 125A, or the guide hole 125B. 8 to 9, a region P ″ (a hatched region indicated by a broken line) is on the bonding surface 11 a with the resin member corresponding to a portion immediately below the pressing region P (see FIG. 1) of the rotary tool 16 on the metal member 11. It is an area.

  FIG. 10 shows an embodiment of the metal member in the case where the metal member 11 has no accumulation groove and has a guide hole 125B. In FIG. 10, (A) is a schematic sketch showing the joining surface 11a with the resin member in the metal member 11 of the third embodiment, and (B) is an AA cross section of the resin member in (A) in the direction of the arrow. It is a schematic sectional drawing when it sees, (C) is a schematic sectional drawing when the joining method of this invention is implemented using the metallic member of (B). In FIG. 10C, the resin member 12 is the resin member of the first embodiment having the accumulation groove 120. In FIG. 10, a region P ″ (a hatched region indicated by a broken line) is the same as in FIGS.

  The reservoir groove 120, the guide groove 125A, and the guide hole 125B formed in the metal member 11 are respectively the same overall shape, cross-sectional shape, and the same as the pool groove 120, the guide groove 125A, and the guide hole 125B described above formed in the resin member 12. Have dimensions. In addition, the dimension represented by the ratio with respect to thickness T (mm) of the resin member 12 shall replace the thickness T with the thickness K of the metal member 11, and shall apply. The formation position of the accumulation groove 120 in the metal member 11 is a position corresponding to the formation position of the accumulation groove 120 in the resin member 12 described above when the metal member 11 and the resin member 12 are overlapped. The formation positions of the guide groove 125A and the guide hole 125B are not particularly limited as long as the softened resin flowing into the accumulation groove 120 during joining can be guided outside the system.

  The pool groove 120, the convex part 122, the guide groove 125A, and the guide hole 125B of the metal member 11 can be formed by cutting the metal member 11 with a cutting tool or the like, for example.

(2) Rotating Tool FIG. 11A is an enlarged view of the tip portion of the rotating tool 16. In FIG. 11A, the right half shows the appearance of the rotary tool 16, and the left half shows a cross section. As shown in FIG. 11A, the columnar rotary tool 16 has a pin portion 16a and a shoulder portion 16b at the tip portion (lower end portion in FIG. 11A). The shoulder portion 16 b is a portion at the tip of the rotary tool 16 including the circular tip surface of the rotary tool 16. The pin portion 16a is a cylindrical portion having a smaller diameter than the shoulder portion 16b, which protrudes outwardly (downward in FIG. 11A) from the circular tip surface of the rotary tool 16 on the central axis X of the rotary tool 16. is there. The pin portion 16a is for positioning the rotating tool 16 when the rotating tool 16 that is rotating is first brought into contact with the workpiece 10 and pressed.

  The material of the rotary tool 16 and the dimensions of each part are mainly set according to the metal type of the metal member 11 pressed by the rotary tool 16. For example, when the metal member 11 is made of an aluminum alloy, the rotary tool 16 is made of tool steel (for example, SKD61), the diameter D1 of the shoulder portion 16b is 10 mm, the diameter D2 of the pin portion 16a is 2 mm, and the pin portion 16a protrudes. The length h is set to 0.5 mm. For example, when the metal member 11 is made of steel, the rotary tool 16 is made of silicon nitride, PCBN (cubic boron nitride sintered body), etc., the diameter D1 of the shoulder portion 16b is 10 mm, and the diameter D2 of the pin portion 16a. Is set to 3 mm, and the protruding length h of the pin portion 16a is set to 0.5 mm. Needless to say, these are merely examples, and the present invention is not limited thereto. For example, the diameter D1 of the shoulder portion 16b is usually 5 to 30 mm, preferably 5 to 15 mm, but is not limited thereto.

(3) One embodiment of the joining method according to the present invention (friction stir welding method)
The joining method (friction stir welding method) of the present invention performed using the friction stir welding apparatus 1 will be specifically described.

The joining method according to the present embodiment includes at least the following steps, and is characterized by using the resin member 12 and / or the metal member 11 having the above-described accumulation groove:
A first step of superimposing the metal member 11 and the resin member 12; and while rotating the rotary tool 16, the metal member 11 is pressed against the metal member 11 to generate frictional heat, and the frictional heat softens the resin member 12 to form the metal member. 2nd step which joins 11 and resin member 12.
The metal member 11 and the resin member 12 obtained in the first step are called “work” 10.

  In the first step, when the resin member 12 has an annular reservoir groove 120 on the bonding surface 12a as shown in FIGS. 2A to 7A, an inner region 126 of the annular reservoir groove 120 is formed. It is preferable that the metal member 11 and the resin member 12 are overlapped so that the hatched region P ′ of the broken line is located inside. As described above, the dashed hatched area P ′ is an area corresponding to a position immediately below the pressing area P of the rotating tool 16 (scheduled pressing area; see FIG. 1) in the metal member 11. Further, when the metal member 11 has an annular reservoir groove 120 as shown in FIGS. 8A to 9A on the joining surface 11a, the inner region 126 of the annular reservoir groove 120 and the resin member 12 are provided. It is preferable that the metal member 11 and the resin member 12 are overlapped so that the desired bonding site is in contact.

In the second step, at least a push-in stirring step C2 is performed in which the rotary tool 16 is pushed into the metal member 11 to enter a depth that does not reach the joint interface between the metal member 11 and the resin member 12.
In the present embodiment, in the second step, the preheating step C1 for rotating the rotary tool 16 in a state in which only the tip portion of the rotary tool 16 is in contact with the surface portion of the metal member 11 is performed before the pushing and stirring step. It is preferable.
After the indentation stirring step, it is preferable to perform an agitation maintaining step C3 in which the rotation operation of the rotary tool 16 is continued at a position where the rotary tool 16 is advanced to a depth that does not reach the joining boundary surface.

In the following, each step will be described in detail, taking as an example the case of using the resin member 12 of the first embodiment shown in FIG. 2 and the metal member 11 having neither the accumulation groove 120 nor the induction groove 125A nor the induction hole 125B.
In the preheating step C1, as shown in FIG. 11B, only the distal end portion of the rotary tool 16 is placed on the surface portion of the metal member 11 (upper surface portion in the illustrated example) by bringing the rotary tool 16 and the receiving member 17 close to each other. This is a step of rotating the rotary tool 16 in a contacted state. In the preheating step C1, the rotary tool 16 is rotated at a predetermined rotation speed (for example, 3000 rpm) for a first pressurizing time (for example, 1.00 seconds) with a first pressure (for example, 900 N).

  In the indentation stirring process C2 next to the preheating process C1, the rotating tool 16 and the receiving member 17 are further brought closer to each other, thereby pushing the rotating tool 16 into the metal member 11 and the metal member 11 as shown in FIG. 11C. In this step, the resin member 12 is advanced to a depth not reaching the joint interface with the resin member 12. In the indentation stirring step C2, the rotary tool 16 is moved to a second pressurization time (for example, 0.25) shorter than the first pressurization time with a second pressurization force (for example, 1500 N) that is greater than the first pressurization force. Seconds) at a predetermined rotation speed (for example, 3000 rpm).

  In the stirring maintaining process C3 subsequent to the indentation stirring process C2, the mutual approach between the rotary tool 16 and the support 17 is stopped, and as shown in FIG. This is a step of continuing the rotation operation of the rotary tool 16 at a position (referred to as “reference position”). In the stirring maintaining step C3, the rotary tool 16 is moved to a third pressurizing time (for example, 5.75) longer than the first pressurizing time with a third pressurizing force (for example, 500 N) smaller than the first pressurizing force. Seconds) at a predetermined rotation speed (for example, 3000 rpm).

After the stirring maintaining step C3, a holding step C4 may be performed in which the rotation of the rotary tool 16 is stopped and the rotary tool 16 is held for a predetermined pressurizing time with a predetermined pressure in that state.
Similarly, as shown in FIG. 11C, the holding step C4 is a step in which the rotation of the rotary tool 16 is stopped and the rotary tool 16 is held for a predetermined time with a predetermined pressure in that state. In the holding step C4, the rotary tool 16 is moved at a fourth pressure force (for example, 1000 N) that is larger than the third pressure force but smaller than the second pressure force and shorter than the third pressurization time but the second pressure force. Hold for a fourth pressurization time (for example, 5.00 seconds) longer than the pressure time.

  The pressurizing force, pressurizing time, and tool rotation speed exemplified above are merely examples, and can be appropriately changed. However, for example, in the case of joining the metal member 11 having a thickness of 1 mm or more and 2 mm or less and the resin member 12 having a thickness of 2 mm or more and 4 mm or less, mainly from the viewpoint of productivity (a balance between time reduction and yield), the preheating step The first applied pressure in C1 is preferably 700 N or more and less than 1200 N, and the first pressurizing time is preferably 0.5 second or more and less than 2.0 seconds. The second applied pressure in the indentation stirring step C2 is The value of 1200N or more and less than 1800N, and the second pressurization time is preferably a value of 0.1 second or more and less than 0.5 second, and the third pressure in the stirring and maintaining step C3 is a value of 100N or more and less than 700N, The third pressurization time is preferably 1.0 second or more and less than 10 seconds. Further, the fourth pressing force in the holding step C4 is preferably a value of 700 N or more and less than 1200 N, for example, and the fourth pressurizing time is preferably a value of 1 second or more, for example.

  Specifically, in the preheating step C <b> 1, frictional heat is generated at the surface portion (upper surface portion in the illustrated example) of the metal member 11 by pressing of the rotary tool 16. The frictional heat is transmitted to the inside of the metal member 11, and the range of the pressing region P of the metal member 11 and the range in the vicinity of the pressing region P are preheated. Thereby, it becomes easy to push the rotary tool 16 into the metal member 11 in the next pushing and stirring step C2.

  In the preheating step C <b> 1, the frictional heat is also transmitted to the resin member 12 through the joint interface between the metal member 11 and the resin member 12. The frictional heat is transmitted to the inside of the resin member 12, and the range of the corresponding region P 'immediately below the pressing region P in the resin member 12 and the range in the vicinity of the region P' are preheated. Thereby, the resin member 12 becomes easy to soften and melt in the next indentation stirring step C2.

  The first pressurizing force and the first pressurizing time in the preheating step C1 are set from the viewpoint of ease of pushing in the rotary tool 16 and the ease of softening / melting of the resin member 12, and values thereof. Varies depending on, for example, the number of rotations of the rotary tool 16 and the types of materials of the metal member 11 and the resin member 12.

  In the indentation stirring step C2, the rotating tool 16 is pushed into the metal member 11 when the applied pressure is larger than that in the preheating step C1. That is, the rotary tool 16 enters deep inside the metal member 11. By pressing the rotary tool 16, the joining boundary surface between the metal member 11 and the resin member 12 moves to the receiving member 17 side (lower side in the illustrated example).

  If the rotary tool 16 is further pushed in (that is, if the applied pressure is too high and / or the pressurizing time is too long), the shoulder portion 16b of the rotary tool 16 exceeds the joining boundary surface. That is, the rotary tool 16 penetrates the metal member 11 and contacts the resin member 12. Then, the metal member 11 is in a holed state in which the hole through which the rotary tool 16 has passed is opened, resulting in poor bonding.

  Therefore, in this embodiment, when the shoulder portion 16b of the rotary tool 16 enters a depth that does not reach the joining boundary surface in the push stirring step C2, the push of the rotary tool 16 is stopped. In other words, the rotary tool 16 is advanced to a depth that does not reach the joint interface. As a result, in the next agitation maintaining step C3, frictional heat is generated at a reference position close to the resin member 12, and a large amount of frictional heat is transmitted to the resin member 12 to promote softening and melting of the resin member 12.

  The second pressing force and the second pressurizing time in the indentation stirring step C2 are set from the viewpoint of avoiding the opening of the metal member 11 as described above and the rotating tool 16 as close to the resin member 12 as possible. The value changes depending on, for example, the number of rotations of the rotary tool 16 and the types of materials of the metal member 11 and the resin member 12.

  In the indentation stirring step C2, the resin member 12 is softened and melted in the range of the corresponding region P ′ immediately below the pressing region P and in the vicinity of the region P ′, and the joint interface between the metal member 11 and the resin member 12 Is deformed, the softening resin flows toward the end face. However, since the resin member 12 has the accumulation groove 120 on the joint surface 12 a with the metal member 11 as described above, the softened resin flows into the accumulation groove 120. For this reason, outflow of the softened resin from between the metal member 11 and the resin member 12 is avoided at the end face of the joined body of the metal member 11 and the resin member 12, and the formation of burrs is sufficiently prevented.

  In the stirring maintaining step C3, the rotating tool 16 is maintained at the reference position by the applied pressure being smaller than that of the preheating step C1 (of course, being smaller than that of the pushing stirring step C2). Since the rotary tool 16 continues to rotate at the reference position close to the resin member 12, a large amount of frictional heat is generated, and most of the generated frictional heat moves to the resin member 12. Therefore, the resin member 12 is sufficiently softened and melted in a wide range beyond the range of the corresponding region P ′ immediately below the pressing region P and the range in the vicinity of the upper region P ′.

  The third pressurizing force and the third pressurizing time in the stirring maintaining step C3 are set from the viewpoint of sufficient softening and melting of the resin member 12 as described above, and the values thereof are, for example, the rotary tool 16. Depending on the number of rotations and the types of materials of the metal member 11 and the resin member 12.

  In the holding step C4, the rotation of the rotary tool 16 is stopped, whereby the generation of frictional heat is completed. That is, the substantial operation as the friction stir welding is finished, and cooling of the workpiece 10 is started. During the cooling period of the workpiece 10, the rotating tool 16 whose rotation has been stopped is pressed between the metal member 11 and the resin member 12 because the applied pressure is smaller than the indentation agitation step C <b> 2 but greater than the agitation maintenance step C <b> 3. It clamps by pinching between the receiving tools 17. Thereby, the adhesive force during cooling between the metal member 11 and the resin member 12 is increased, and the bonding strength after completion of cooling is increased.

  The fourth pressurizing force and the fourth pressurizing time in the holding step C4 are set from the viewpoint of improving the adhesion of the pressing region P during the cooling period as described above, and the values thereof are, for example, the metal member 11 and the resin member. It varies depending on the type of 12 materials.

  In this embodiment, at least through the above-described step C2, preferably through the above-described steps C1, C2 and C3 and optionally through step C4, finally, as shown in FIG. The resin member 12 is softened and melted by the frictional heat generated by the pressing, and the joined member 20 of the metal member 11 and the resin member 12 in which the metal member 11 and the resin member 12 are joined with high strength in a wide range is obtained. In the bonded body 20, the softened and melted resin flows into the accumulation groove 120 and is cooled and solidified, so that the softened resin 121 contributes to the bonding between the metal member 11 and the resin member 12. , Generation of burrs is prevented.

  As described above, the case where the metal member and the resin member are joined to each other in a dotted manner without continuously moving the rotating tool in the surface direction on the contact surface of the metal member (point joining) has been described. It is clear that the effect of the present invention can be obtained even when the metal member and the resin member are joined linearly (line joining) while continuously moving the rotary tool.

[Example 1]
(Resin member)
A flat resin member 12 having a retaining groove 120 having a size and shape as shown in FIGS. 12A and 12B at its end was manufactured by injection molding from PA66 (manufactured by Asahi Kasei Chemicals Corporation). The reservoir groove 120 was formed by transferring a molding surface of a mold used in the injection molding method.
(Metal member)
As the metal member, a flat plate member (thickness: 1.2 mm) made of a 6000 series aluminum alloy was used.
(Rotation tool)
As the rotating tool, a tool made of tool steel having dimensions of each part in FIG. 11A of D1 = 10 mm, D2 = 2 mm, and h = 0.5 mm was used.

(Joining method)
The joined body of the metal member 11 and the resin member 12 was manufactured by the following method.
First step:
The end of the metal member 11 and the end of the resin member 12 were overlapped as shown in FIG. Specifically, the metal member 11 and the resin member 12 are overlapped so that the corresponding region P ′ immediately below the pressing region P is positioned at the center of the inner region 126 of the annular pool groove 120 in the resin member 12.

Second step:
As shown in FIG. 11B, the rotary tool 16 was rotated in a state where only the tip of the rotary tool 16 was in contact with the surface portion of the metal member 11 (preheating step C1: pressurizing force 900 N, pressurizing time 1.00 seconds. Tool rotation speed 3000r).
Next, as shown in FIG. 11C, the rotary tool 16 was pushed into the metal member 11 and entered to a depth that did not reach the joint interface between the metal member 11 and the resin member 12 (pushing stirring step C2: applied pressure 1500 N, applied pressure). Pressure time 0.25 seconds, tool rotation speed 3000 rpm).
Next, as shown in FIG. 11C, the rotation operation of the rotary tool 16 was continued at the position where the rotary tool 16 was advanced to a depth that did not reach the joining boundary surface (stirring maintenance step C3: pressurizing pressure 500N, pressurizing time) 5.75 seconds, tool rotation speed 3000 rpm).
Next, as shown in FIG. 11D, the rotary tool 16 was extracted from the joined body 20 and allowed to cool.

(Joint strength)
The joined body in which the metal member and the resin member were joined by a method defined in JIS Z 3136 was pulled in the directions indicated by arrows Y and Y in FIG.

(Burr generation)
When the appearance on the end face of the joined body was visually observed, no burrs were generated.

[Comparative Example 1]
The resin member was manufactured and the bonding strength and the occurrence of burrs were evaluated by the same method as in Example 1 except that the reservoir groove was not formed in the resin member.
The bonding strength was equivalent to that of Example 1, but burrs were remarkably generated.

[Example 2]
The resin member was manufactured by the same method as in Example 1 except that the resin member was the resin member 12 having the accumulation groove 120 and the convex part 122 as shown in FIGS. 13A and 13B. In addition, the bonding strength and the occurrence of burrs were evaluated.
There were no burrs.

[Comparative Example 2]
The resin member was manufactured and the bonding strength and the occurrence of burrs were evaluated by the same method as in Example 2 except that the reservoir groove was not formed in the resin member.
The bonding strength was equivalent to that of Example 2, but burrs were remarkably generated.

[Example 3]
The resin member was manufactured by the same method as in Example 1 except that the resin member was the resin member 12 having the accumulation groove 120 and the convex portion 122 at the ends as shown in FIGS. 14 (A) and 14 (B). In addition, the bonding strength and the occurrence of burrs were evaluated.
There were no burrs.

[Comparative Example 3]
The resin member was manufactured and the bonding strength and the occurrence of burrs were evaluated by the same method as in Example 3 except that the reservoir groove was not formed in the resin member.
The bonding strength was equal to that in Example 3, but burrs were remarkably generated.

[Example 4]
The resin member was manufactured by the same method as in Example 1 except that the resin member was the resin member 12 having the accumulation groove 120 and the guide groove 125A as shown in FIGS. 15A and 15B. In addition, the bonding strength and the occurrence of burrs were evaluated.
There were no burrs.
FIG. 15C is a schematic cross-sectional view when the obtained bonded body is viewed in the B direction of FIG. 15B.

[Comparative Example 4]
The production of the resin member and the evaluation of the bonding strength and the occurrence of burrs were performed by the same method as in Example 4 except that the reservoir groove and the guide groove were not formed in the resin member.
The bonding strength was the same as in Example 4, but burrs were remarkably generated.

  The joining method according to the present invention is useful for joining a metal member and a resin member in the fields of automobiles, railway vehicles, aircraft, home appliances, and the like.

1: Friction stir welding apparatus 10: Workpiece 11: Metal member 11a: Contact region with resin member on metal member surface 12: Resin member 12a: Contact region with metal member on resin member surface 16: Rotating tool 17: Receiving tool 20 : Bonded body P: Pressing area (scheduled pressing area) by rotating tool on metal member surface
P ′: Resin member surface region corresponding directly below the pressing region P P ″: Metal member surface region corresponding immediately below the pressing region P 120: Reservoir groove 121: Softened resin flowing into the reserving groove 125A: Guide groove 125B: Guide hole 126: Inner region of the annular pool groove

Claims (6)

The first step that overlay the metal member and the resin member; and
While rotating the rotary tool, the metal member is pressed to generate frictional heat, and by applying heat and pressure from the metal member side , the resin member is softened by this frictional heat, and the metal member and the resin member are separated. A joining method of a metal member and a resin member by a hot-pressure joining method based on a friction stir welding method including a second step of joining,
In the bonding surface of the resin member with the metal member and / or the bonding surface of the metal member with the resin member, a reservoir groove is formed to allow the resin softened at the time of bonding to flow .
The second step includes a pushing and stirring step of pushing the rotating tool into the metal member to enter a depth not reaching the joining interface between the metal member and the resin member,
The rotary tool has a shoulder portion including a circular tip surface of the rotary tool at the tip portion, and a cylindrical pin having a smaller diameter than the shoulder portion, which protrudes outward from the circular tip surface of the rotary tool. Part
The second step further includes a preheating step of rotating the rotating tool in a state where only the pin portion and the shoulder portion at the tip portion of the rotating tool are in contact with the surface portion of the metal member before the pushing and stirring step. And
In the preheating step, the rotary tool is rotated by a first pressurizing time while being pressed with a first pressing force,
In the indentation stirring step, the rotating tool is rotated by a second pressurization time shorter than the first pressurization time while pressing the rotary tool with a second pressurization force larger than the first pressurization force. A method of joining a member and a resin member.   The joining method according to claim 1, wherein the accumulation groove is formed in an annular shape on the joining surface, and heat and pressure are applied in an inner region of the annular accumulation groove.   The resin member and / or the metal member further has a guide groove formed on the bonding surface and / or a guide hole penetrating in the thickness direction, and the guide groove and the guide hole are accumulated at the time of bonding and flow into the groove. The bonding method according to claim 1, wherein the bonding is induced out of the system.   The joining method according to any one of claims 1 to 3, wherein the resin member is molded by a melt molding method, and a pool groove is formed by transferring a molding surface of a mold used in the melt molding method. The second step further comprises an agitation maintaining step of continuing the rotating operation of the rotating tool at a position where the rotating tool has entered to a depth that does not reach the joining boundary surface,
In the stirring step of maintaining of claims 1 to 4 for rotating only between the rotary tool while pressing in the first pressure is less than the third pressure greater than between the first pressurization third pressurization The joining method according to any one of the above. The said 2nd step is further equipped with the holding process which stops rotation of the said rotation tool after a stirring maintenance process, and hold | maintains the said rotation tool with a predetermined pressurizing force for a predetermined pressurization time in that state. 5. The joining method according to 5 .

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