JP6056828B2 - Method of joining metal member and resin member and resin member used in the method - Google Patents

Description

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

  Conventionally, weight reduction is required in the fields of automobiles, railway vehicles, airplanes, and the like. For example, in the field of automobiles, the use of high-tensile materials has made it possible to make steel sheets thinner, aluminum alloy materials have been used as substitutes for steel materials, and resin materials have also been increasingly used. In these fields, development of joining technology for metal members and resin members is important not only for reducing the weight of the car body, but also for increasing the strength and rigidity of the joining members and improving productivity. is there. 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. 19, 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 melted and then solidified to join the metal member 211 and the resin member 212 together.

  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.

  On the other hand, a technique for improving the strength of a resin member by adding a reinforcing fiber to the resin member is known. For example, in the field of compression molding methods, it is a fiber reinforced thermoplastic resin composite material composed of reinforced fibers and a thermoplastic resin from the viewpoint of preventing resin deterioration, improving productivity, and increasing strength and elastic modulus. Disclosed is a compression molding material in which a reinforcing fiber having a specific fiber length is contained in a specific volume content and a specific number of reinforcing fibers included in a minimum unit in which the reinforcing fiber has the same fiber axis direction in an arbitrary cross section. (Patent Document 2).

JP 2010-158885 A JP 2004-142165 A

  However, in the conventional friction stir welding method, when a conventional fiber reinforced resin member is used, the bonding strength may be reduced.

  The inventors of the present invention have intensively studied the phenomenon of such a decrease in bonding strength, and as a result, have found that the phenomenon is caused by springback of reinforcing fibers contained in the resin member. Specifically, as shown in FIG. 20A, the pressing member 216 is pushed into the metal member 211, and the region 221 immediately below the pressing member of the resin member 212 and its outer peripheral region are melted by frictional heat, and then solidified. As a result, a springback in which the reinforcing fibers were exposed in the melted and solidified region of the resin member 212 occurred. The spring back is a phenomenon in which the curved reinforcing fiber is released from the restraining force when the resin member 212 is melted and deforms so as to return straight. When such a springback occurs, as shown in FIG. 20B, bubbles are mixed in the melt-solidified region of the resin member 212 to form a bubble layer 222 that appears to be foamed. It is considered that the bonding strength is reduced by the occurrence of intra-layer fracture in the low-bubble cell layer 222.

  An object of this invention is to provide the joining method of the metal member and resin member which can achieve joining with sufficient intensity | strength of a resin member and a metal member.

The present invention
Heat that achieves bonding after overlapping a metal member and a resin member containing reinforcing fibers, applying heat and pressure by pressing from the metal member side by the pressing member, softening and melting the resin member, and solidifying A method of joining a metal member and a resin member by a pressure joining method,
As the resin member, a resin member having a degree of orientation y1 / x of the reinforcing fiber contained in at least the joint portion with the metal member as described below is used:
1 ≦ y1 / x ≦ 1.3
(Wherein x is the average diameter (μm) of the vertical cross section with respect to the axial direction of the reinforcing fiber; y1 is the average value (μm) of the maximum diameter of the reinforcing fiber in the vertical cross section with respect to the resin member thickness direction of the joint portion) The average value of the maximum diameter in the vertical cross section when the bonded portion is polished from the surface to a depth of 500 μm in the thickness direction).

The present invention also provides
A first step of superimposing a metal member and a resin member containing reinforcing fibers; and while rotating the rotary tool as the pressing member, the metal member is pressed against the metal member to generate frictional heat, and the frictional heat softens the resin member. A second step of joining the metal member and the resin member by melting and then solidifying;
A method of joining a metal member and a resin member by a friction stir welding method including:
As the resin member, a resin member having a degree of orientation y1 / x of the reinforcing fiber contained in at least the joint portion with the metal member as described below is used:
1 ≦ y1 / x ≦ 1.3
(Wherein x is the average diameter (μm) of the vertical cross section with respect to the axial direction of the reinforcing fiber; y1 is the average value (μm) of the maximum diameter of the reinforcing fiber in the vertical cross section with respect to the resin member thickness direction of the joint portion) The average value of the maximum diameter in the vertical cross section when the bonded portion is polished from the surface to a depth of 500 μm in the thickness direction).

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

  According to the joining method of the present invention, even when the reinforcing fiber is contained in the resin member, the joining of the resin member and the metal member can be achieved with sufficient strength.

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 schematic perspective view of an example (convex type) of a resin member used in the bonding method of the present invention, and (B) is a schematic top view of the resin member of (A) and the height in the columnar rib for bonding. It is an expansion schematic diagram of the vertical cross section with respect to a direction, (C) is a schematic cross section when the WW cross section of the resin member of (B) is seen in the arrow direction, and a cross section parallel to the height direction of the columnar rib for joining FIG. (A) is a schematic perspective view of another example (flat type) of the resin member used for the joining method of the present invention, and an enlarged schematic view of a vertical cross section with respect to the thickness direction at the joint, (B) is (A) FIG. 5C is a schematic top view of the resin member of FIG. 5C, and FIG. 5C is a schematic cross-sectional view of the resin member of FIG. FIG. (A) is a schematic top view of one embodiment of a convex resin member used in the bonding method of the present invention, and (B) is a view of the WW cross section of the resin member of (A) in the arrow direction. (C) is a schematic sectional drawing for demonstrating the manufacturing method when manufacturing the resin member of (B) by injection molding. (A) is a schematic perspective view of another embodiment of the convex resin member used in the bonding method of the present invention, (B) is a schematic top view of the resin member of (A), (C) FIG. 5 is a schematic cross-sectional view of the resin member of FIG. It is a schematic sectional drawing for demonstrating the manufacturing method when manufacturing the resin member of FIG. 5 by injection molding. (A) is a schematic perspective view of one embodiment of the flat resin member used in the bonding method of the present invention, (B) is a schematic top view of the resin member of (A), and (C) is ( It is a schematic sectional drawing when the WW cross section of the resin member of B) is seen in the arrow direction. It is a schematic sectional drawing for demonstrating the manufacturing method when manufacturing the resin member of FIG. 7 by injection molding. (A) is a schematic perspective view of another embodiment of the flat resin member used in the bonding method of the present invention, (B) is a schematic top plan view of the resin member of (A), (C) FIG. 5 is a schematic cross-sectional view of the resin member of FIG. It is a schematic sectional drawing for demonstrating the manufacturing method when manufacturing the resin member of FIG. 9 by injection molding. It is an enlarged view of the front-end | tip part of an example of the rotation tool as a press member used for the joining method of this invention. It is a schematic sectional drawing for demonstrating an example of the preheating process of this invention using the convex resin member of FIG. It is a schematic sectional drawing for demonstrating an example of the pushing stirring process of this invention using the convex resin member of FIG. 2, a stirring maintenance process, and a holding process. It is a schematic sectional drawing of an example of the joined body of the metal member and resin member joined by the method of this invention using the convex resin member of FIG. It is a schematic sectional drawing for demonstrating an example of the preheating process of this invention using the flat resin member of FIG. It is a schematic sectional drawing for demonstrating an example of the pushing stirring process of this invention using the flat resin member of FIG. 3, a stirring maintenance process, and a holding process. It is a schematic sectional drawing of an example of the joined body of the metal member and resin member joined by the method of this invention using the flat resin member of FIG. It is the schematic for demonstrating the measuring method of the joint strength in an Example. It is this schematic sketch for demonstrating the joining method of the metal member and resin member in a prior art. (A) is a schematic sectional drawing for demonstrating the joining method of the metal member and resin member in a prior art, (B) is the metal member and resin member in the joined_body | zygote obtained by the method of (A). It is an enlarged view of the joining boundary surface.

  In the joining method of the present invention, the metal member and the resin member are overlapped, and heat and pressure are applied by pressing from the metal member side or the resin member side by the pressing member, preferably by local pressing from the metal member side by the pressing member. Is applied, and the resin member is softened and melted and then solidified to join the metal member and the 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 applying heat and pressure. For example, friction stir welding method, ultrasonic heating joining method, laser heating joining method, resistance A heat bonding method, an induction heat bonding method, or the like may be used. A method of applying heat and pressure locally from the metal member side is preferable, and a friction stir welding method is more preferably used.

  As will be described in detail later, the friction stir welding method is a method in which a metal member and a resin member are overlapped and a rotating tool as a pressing member is rotated to press the metal member to generate frictional heat. In this method, the resin member is softened and melted by heat and then solidified to join the metal member and the resin member.

  The ultrasonic heating bonding method is a resin member / metal member produced by superposing a metal member and a resin member and causing the pressing member and the resin member to ultrasonically vibrate while pressing the resin member with the pressing member. In this method, the resin member is softened and melted by the frictional heat, and then solidified to join the metal member and the resin member.

  The laser heating joining method is a method in which a metal member and a resin member are overlapped, heat is generated by irradiating the metal member with a laser in a state where the metal member is pressed by the pressing member, and the resin member is softened by this heat. Further, after melting, the metal member and the resin member are joined by solidifying. 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 through a metal member in a state where the metal member and the resin member are superposed 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 metal member and the resin member are superposed and restrained, and bonding is performed using heat generated by the current.

  Hereinafter, the joining method of the present invention that employs the friction stir welding method will be described in detail 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. It is clear.

[Method of joining metal member and resin member by friction stir welding method]
The joining method (friction stir welding method) of the present invention will be specifically described with reference to FIGS. In these drawings, common reference numerals indicate the same members, parts, dimensions, or regions unless otherwise specified.

  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. 11), 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 the friction heat is conducted to the resin member 12 to soften and melt the resin member 12, and then the molten resin is solidified. As a result, the metal member 11 and the resin member 12 are joined. FIG. 1 is a schematic diagram showing an example of a part of a friction stir welding apparatus suitable for a method for joining a metal member and a resin member according to the present invention.

  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) Resin Member In the present invention, the resin member 12 is a composite resin member containing a thermoplastic polymer and reinforcing fibers, and the reinforcing fibers 128 are at least in the thickness direction (that is, depending on the rotary tool 16) at the joint with the metal member 11. It is oriented in the pressing direction A2 (see FIG. 1).

  The joint portion is a joint portion between the resin member 12 and the metal member 11, and at least the surface layer portion of the region (predetermined joint planned region) to be joined on the resin member surface, preferably the predetermined joint planned region. It is a surface layer part. Specifically, the joint portion is at least a surface layer portion of a region including a melt-solidified region where melting and solidification occurs after joining on the surface of the resin member 12, and preferably a surface layer portion of the melt-solidified region. The region to be joined is usually a partial region on one side of the resin member. For example, when the resin member has a flat plate shape, the entire region of one surface or both surfaces of the resin member may be used. Good.

  For example, when the resin member 12 is a convex resin member 12 </ b> A having a main body portion 124 and a joining columnar rib 125 as shown in FIGS. 2A to 2C, the joining portion is the tip of the joining columnar rib 125. This is a portion 122 (shaded portion in FIG. 2C) from the surface to the depth L1 in the planar region. The depth L1 is normally H / 5 to H, where H (mm) is the height of the columnar rib 125 for bonding. H is usually 2.5 to 20 mm, preferably 3 to 10 mm. The thickness t1 of the main body 124 is usually 1 to 10 mm, preferably 2 to 5 mm.

  The joining columnar rib 125 achieves joining by melting and solidifying the rib itself. The shape of the joining columnar rib 125 is not particularly limited as long as it is a columnar shape, and is, for example, a polygonal columnar shape such as a columnar shape or a quadrangular columnar shape as shown in FIGS. Good. When the joining columnar ribs 125 are cylindrical, it is preferable that the circular tip plane region of the ribs 125 be concentric with the pressing region P of the metal member by the rotating tool. The width of the joining columnar rib (diameter when the joining columnar rib 125 is cylindrical) R1 is usually 0.5 × D1 to 5 × D1 when the diameter of the rotary tool 16 is D1 (mm). , Preferably 0.5 × D1 to 2 × D1. D1 is usually within the range described below.

  Further, for example, when the resin member 12 is a flat resin member 12B that does not have the columnar ribs for bonding as shown in FIGS. 3A to 3C, the bonding portion is a predetermined bonding schedule on the surface of the resin member. This is a portion 122 (shaded portion in FIG. 3C) from the surface to the depth L2 in the region E. The depth L2 is usually t2 / 5 to t2 / 2 when the thickness of the resin member is t2 (mm). t2 is usually 5 to 20 mm, preferably 8 to 15 mm.

  The shape of the region to be joined E is not particularly limited, and may be, for example, a circular shape such as a circle or a quadrangle as shown in FIGS. From the viewpoint of preventing sufficiently, it is preferably circular. When the joining area | region E is circular, it is preferable that the joining area | region E is concentric with the press area | region P of the metal member by a rotary tool. The width R2 of the planned joining region E (diameter when the joining planned region E is circular) is usually greater than D1 and not more than 5 × D1, preferably 1.2, when the diameter of the rotary tool is D1 (mm). XD1-3xD1. D1 is usually within the range described below.

Regardless of whether the resin member 12 is a convex resin member 12A or a flat resin member 12B as described above, the reinforcing fibers 128 contained in the predetermined joining portion 122 are oriented in the thickness direction. That the reinforcing fiber is oriented in the thickness direction means that the reinforcing fiber has the degree of orientation (y / x) represented by the formula (I), preferably the formula (II), more preferably the formula (III). is there:
1 ≦ y / x ≦ 1.3 (I)
1 ≦ y / x ≦ 1.2 (II)
1 ≦ y / x ≦ 1.1 (III)

In the formulas (I) to (III), x is an average diameter (μm) of a vertical section with respect to the axial direction of the reinforcing fiber, and a value obtained by the following method is used.
The joint is polished in the vertical direction, and a micrograph (SEM photograph) of the obtained cross section is taken. In this photograph, the diameter of an arbitrary 100 fibers whose fiber cross section is a perfect circle is measured, and the average value is obtained. Since x is a general so-called average diameter, specification data of a reinforcing fiber used at the time of manufacturing a resin member, particularly a joint portion may be used.
x is usually 2 to 20 μm, preferably 6 to 15 μm.

y is the average value (μm) of the maximum diameter of the reinforcing fibers in the vertical cross section with respect to the resin member thickness direction of the joint portion, and a value obtained by the following method is used.
The joint portion is polished from the surface to a predetermined depth in the thickness direction, and a micrograph (SEM photograph) of a vertical section with respect to the resin member thickness direction is taken. In this photograph, as shown in the enlarged views of FIG. 2 (B) and FIG. 3 (B), the maximum diameter (length in the arrow direction) of any 100 reinforcing fibers is measured, and the average value is obtained.

  The degree of orientation y / x corresponds to 1 / cos θ when the inclination angle of the reinforcing fiber 128 with respect to the thickness direction is expressed as θ, as shown in the partially enlarged views of FIGS. 2 (C) and 3 (C). The value is an index of orientation meaning that the closer to 1, the better the reinforcing fiber is oriented in the thickness direction.

In the present invention, the resin member only needs to satisfy the above formulas (I) to (III) in the orientation degree y1 / x of the reinforcing fiber at a depth of 500 μm from the surface of the joint. Specifically, the degree of orientation y1 / x (x is the same as that in the above formula) with respect to the average value y1 (μm) of the maximum diameter of the reinforcing fibers in the vertical cross section when the bonded portion is polished from the surface to a depth of 500 μm in the thickness direction. May satisfy the range of the above formulas (I) to (III). Specifically, in the present invention, the degree of orientation y1 / x satisfies the following formula:
1 ≦ y1 / x ≦ 1.3;
Preferably 1 ≦ y1 / x ≦ 1.2;
More preferably, 1 ≦ y1 / x ≦ 1.1.

In the present invention, from the viewpoint of further sufficiently preventing the spring back, the resin member has not only the orientation degree y1 / x of the reinforcing fiber at a depth of 500 μm from the surface of the joint portion within the above range, Orientation degree y2 / x of reinforcing fibers at a predetermined depth deep (x is the same as in the above formula; y2 is an average value of the maximum diameter of reinforcing fibers in a vertical cross section when polished to a deeper predetermined depth (μm ) Is preferably within the above range. In the case of the convex resin member 12A, the “further predetermined depth” is a depth of L1 = H / 3, where the height of the joining columnar rib 125 is H (mm), and is flat. In the case of the resin member 12B, when the thickness of the resin member 12B is t2 (mm), L2 = depth of t2 / 5. Accordingly, the orientations of the average values y1 (μm) and y2 (μm) of the maximum diameter of the reinforcing fibers in the vertical cross section when the bonded portion is polished from the surface to a depth of 500 μm in the thickness direction and the predetermined depth, respectively. The degrees y1 / x and y2 / x preferably satisfy the ranges of the above formulas (I) to (III). Specifically, the orientation degree y1 / x and the orientation degree y2 / x preferably satisfy the following formulas:
1 ≦ y1 / x ≦ 1.3 and 1 ≦ y2 / x ≦ 1.3;
More preferably 1 ≦ y1 / x ≦ 1.2 and 1 ≦ y2 / x ≦ 1.2;
More preferably, 1 ≦ y1 / x ≦ 1.1 and 1 ≦ y2 / x ≦ 1.1.

  As described above, by orienting the reinforcing fibers in the joining portion 122 in parallel to the thickness direction, the spring back at the time of joining the resin member 12 can be sufficiently prevented. The details of the mechanism for preventing springback are not clear, but are thought to be based on the following phenomenon. In the conventional resin member, the reinforcing fiber is restrained while being bent due to pressure during molding and solidification of the surrounding thermoplastic polymer. When the thermoplastic fiber is released from restraint due to melting of the thermoplastic polymer during bonding, the fiber is bent. Since it becomes bulky in the thickness direction by being relaxed, it is considered that springback occurs. In the present invention, the reinforcing fibers are oriented sufficiently parallel to the thickness direction at the joint, so that they hardly become bulky at the time of melting. In addition, the fiber is hardly bent even during melting. As a result, it is considered that springback is sufficiently prevented. If the reinforcing fibers are not sufficiently oriented in the thickness direction at the joint, that is, if y1 / x is too large, springback occurs, resulting in a decrease in joint strength.

As the thermoplastic polymer constituting the resin member 12 (12A and 12B), 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 and acid-modified products thereof;
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);
Acrylonitrile-butadiene-styrene copolymer resin (ABS);
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).

  As the thermoplastic polymer constituting the resin member 12, a polyolefin-based resin, particularly polypropylene and polyamide-based resin, which are inexpensive and excellent in mechanical properties are preferably used.

  The molecular weight of the thermoplastic polymer is not particularly limited. For example, the molecular weight may be such that the MFR (melt flow rate value) at 230 ° C. is 2 to 200 g / 10 minutes, particularly 2 to 55 g / 10 minutes. .

  In this specification, the value measured by JIS K 7210 is used for the MFR of the polymer.

  In the field of polymer-containing composite materials, the reinforcing fiber 128 is a fiber that is contained in a polymer for the purpose of improving the strength. Generally, the reinforcing fiber 128 is roughly classified into a continuous fiber and a discontinuous fiber. Means in particular discontinuous fibers. The type of reinforcing fiber is not particularly limited, and examples thereof include carbon fiber and glass fiber.

  In the entire resin member, the reinforcing fiber has an average fiber length of usually 50 mm or less, particularly 0.1 to 50 mm, preferably 1 to 50 mm. The average fiber length of the reinforcing fiber at the joint is usually 50 mm or less, particularly 0.1 to 50 mm, preferably 1 to 50 mm. The average fiber diameter of the reinforcing fibers is not particularly limited in the resin member as a whole or in the joint, and is usually in the same range as x.

  The content of the reinforcing fibers 128 with respect to the total amount of the resin member 12 (12A and 12B) is usually 10 to 50% by weight, preferably 20 to 40% by weight. In particular, the content of the reinforcing fiber 128 in the joint 122 is usually 10 to 50% by weight, preferably 20 to 40% by weight, based on the total amount of the joint.

As the content of the reinforcing fiber 128 with respect to the total amount of the resin member, a value based on the amount of each material used at the time of manufacturing the resin member can be used, or a value measured by the following method can be used.
First, the entire resin member is heated by an electric furnace or the like at a temperature not lower than the decomposition temperature of the thermoplastic polymer and not higher than the decomposition temperature of the reinforcing fiber, thereby removing the thermoplastic polymer and taking out only the reinforcing fiber. By measuring the weight before and after heating, the content of reinforcing fibers can be calculated as a ratio to the weight before heating. Alternatively, the content can be measured by measuring the specific gravity.

  The content of the reinforcing fiber 128 in the joint can be measured by the same method as the method for measuring the content of the reinforcing fiber with respect to the total amount of the resin member, except that only the joint is cut out and measured.

  The average fiber length and average fiber diameter of the reinforcing fibers in the entire resin member are measured by a method of directly measuring the average fiber length and average fiber diameter of the obtained reinforcing fibers in the method for measuring the content of reinforcing fibers with respect to the total amount of the resin member. can do.

  The average fiber length and average fiber diameter of the reinforcing fibers contained in the joint are determined by directly measuring the average fiber length and average fiber diameter of the reinforcing fibers obtained in the method for measuring the content of reinforcing fibers in the joint. Can be measured.

  Hereinafter, the 1st-4th embodiment of the resin member 12 and its manufacturing method are demonstrated using drawing.

  The resin member shown in FIGS. 4A and 4B is one of specific examples of the convex resin member 12A shown in FIGS. 2A to 2C, and is the resin member 12A-1 of the first embodiment. It is.

  The resin member 12A-1 can be easily manufactured by an injection molding method using the molds 151A and 151B having a molding surface corresponding to the shape of the resin member. Specifically, as shown in FIG. 4C, a predetermined thermoplastic polymer and reinforcing fiber are previously melted and mixed in the injection machine 150, and the molten mixture is put into the closed predetermined molds 151A and 151B. Inject injection. At this time, by selecting the position of the injection inlet 151 so that the joining columnar rib 125 becomes the flow end as the flow path of the molten mixture, the flow in the arrow direction in FIG. At 122, the reinforcing fibers can be oriented in the thickness direction. In FIG. 4B, the height H and the width R1 of the joining columnar rib 125 and the thickness t1 of the main body 124 are within the same ranges as in FIG. From the viewpoint of the orientation of the reinforcing fibers in the joint portion 122, R1 / t1 is preferably 1-20, more preferably 1-10. From the same viewpoint, H / R1 is preferably 0.2 to 5, and more preferably 0.5 to 4.

  The resin member shown in FIGS. 5A to 5C is one of specific examples of the convex resin member 12A shown in FIGS. 2A to 2C, and the resin member 12A-2 of the second embodiment. It is. In the resin member 12 </ b> A- 2, the joining columnar rib 125 has a groove 126. By forming the groove portion 126 in the rib 125, the melt of the rib 125 is accommodated in the groove portion 126 at the time of joining, so that the metal member 11 and the main body portion 124 of the resin member 12A-2 can be brought into contact with each other. In FIG. 5B, the groove 126 is formed in an annular shape or a dot shape. As a result, the rib 125 is divided into an outer cylindrical rib 125A and an inner cylindrical rib 125B, but the present invention is not limited to this. For example, it may be divided by one or more linear grooves.

  The resin member 12A-2 can be easily manufactured by an injection molding method using the molds 151A and 151B having a molding surface corresponding to the shape of the resin member. Specifically, as shown in FIG. 6, a predetermined thermoplastic polymer and reinforcing fiber are previously melted and mixed in the injection machine 150, and the molten mixture is injected and injected into the closed molds 151A and 151B. To do. At this time, by selecting the position of the injection inlet 151 so that the divided ribs 125A and 125B become the flow ends as the flow path of the molten mixture, the flow in the arrow direction in FIG. The fibers can be oriented in the thickness t direction. In FIG. 5C, the height H and width (full width) R1 of the rib 125 (divided ribs 125A and 125B) and the thickness t1 of the main body 124 are within the same ranges as in FIG. The width R3 of the dividing ribs 125A and 125B is usually 1 to 10 mm, preferably 2 to 8 mm. The width R4 of the groove 126 is usually 1 to 8 mm, preferably 1 to 5 mm. The depth L3 of the groove part 126 is 0-3 mm normally, Preferably it is 0.3-2 mm. From the viewpoint of the orientation of the reinforcing fibers in the joint portion 122, R3 / t1 is preferably 0.1 to 5, and more preferably 0.2 to 2. From the same viewpoint, H / R3 is preferably 0.5 to 20, and more preferably 1 to 10.

  The resin member shown in FIGS. 7A to 7C is one of specific examples of the flat resin member 12B shown in FIGS. 3A to 3C, and is the resin member 12B-1 of the third embodiment. It is.

  The resin member 12B-1 is obtained by an injection molding method using a mold having a molding surface corresponding to the shape of the resin member 12A-1 and the resin member 12B-1 in which the reinforcing fibers are oriented in the thickness direction at the joint portion 122. It can be easily manufactured. Specifically, as shown in FIG. 8, a pre-molded resin member 12A-1 is inserted into predetermined molds 151A and 151B as a preformed body 127A. A predetermined thermoplastic polymer and a reinforcing fiber that is optionally contained are previously melted and mixed in the injection machine 150, and the molten mixture is injected and injected into the closed molds 151A and 151B. Part 129A of the substrate is formed. In FIG. 7C, the depth L2 of the joining portion, the thickness t2 of the resin member, and the width R2 of the planned joining region E are within the same ranges as in FIG.

  In the resin member 12B-1, the portion 129A other than the preform includes a thermoplastic polymer, and preferably includes reinforcing fibers from the viewpoint of improving the strength of the resin member. The average fiber length of the reinforcing fibers in the portion 129A other than the preform is usually 0.1 to 50 mm, preferably 1 to 50 mm. The average fiber diameter of the reinforcing fibers in the portion 129A other than the preform is not particularly limited, and is, for example, 2 to 20 μm, preferably 6 to 15 μm. The kind of the reinforcing fiber in the portion 129A other than the preformed body can be the same as that of the reinforcing fiber 128 in the resin member 12A-1 as the preformed body 127A. In the portion 129A other than the preform, the content of the reinforcing fiber is not particularly limited, but is preferably 10 to 50% by weight based on the total amount of the portion 129A other than the preform from the viewpoint of improving the strength. More preferably, it is 20 to 40% by weight.

In the present specification, the average fiber length, average fiber diameter, and amount of the reinforcing fibers contained in the portion 129A other than the preform are values based on physical properties and usage amounts of the respective materials at the time of manufacturing the resin member 12B-1. Can be used.
The content of the reinforcing fiber in the portion other than the preform is measured by the same method as the method for measuring the content of the reinforcing fiber with respect to the total amount of the resin member, except that only the portion other than the preform is cut out and measured. Can do.
The average fiber length and average fiber diameter of the reinforcing fibers contained in the portion other than the preform are the average fiber length and average of the reinforcing fibers obtained in the method for measuring the content of reinforcing fibers in the portion other than the preform. It can be measured by a method of directly measuring the fiber diameter.

  The thermoplastic polymer constituting the preform 127A and the thermoplastic polymer constituting the portion 129A other than the preform are independently selected from the thermoplastic polymers. Two or more types of the thermoplastic polymer constituting the preformed body 127A and the thermoplastic polymer constituting the portion 129A other than the preformed body may be contained in combination.

  The reinforcing fibers contained in the preformed body 127A and the reinforcing fibers contained in the portion 129A other than the preformed body are independently selected from the reinforcing fibers. The reinforcing fiber contained in the preformed body 127A and the reinforcing fiber contained in the portion 129A other than the preformed body may be contained in combination of two or more kinds.

  The resin member shown in FIGS. 9A to 9C is one of specific examples of the flat resin member 12B shown in FIGS. 3A to 3C, and is the resin member 12B-2 of the fourth embodiment. It is.

  The resin member 12B-2 can be easily manufactured by an injection molding method using a molded body in which reinforcing fibers are oriented in one direction in advance and a mold having a molding surface corresponding to the shape of the resin member 12B-2. it can. Specifically, as shown in FIG. 10, a molded body in which reinforcing fibers are oriented in one direction in advance is inserted into predetermined molds 151A and 151B as a preformed body 127B. The preformed body 127B can be manufactured by cutting an extruded body of reinforcing fibers. A predetermined thermoplastic polymer and a reinforcing fiber that is optionally contained are previously melted and mixed in the injection machine 150, and the molten mixture is injected and injected into the closed molds 151A and 151B. The portion 129B is formed. To do. In FIG. 9C, the depth L2 of the joint, the thickness t2 of the resin member, and the width R2 of the planned joining region E are within the same ranges as in FIG.

  In the resin member 12B-2, the part 129B other than the preform is the same as the part 129A other than the preform in the resin member 12B-1.

(2) Metal member Although the metal member 11 has a substantially flat plate shape as a whole in FIG. 1 and the like, it is not limited to this, and at least a portion overlapping with the resin member 12, particularly a rotary tool. As long as the vicinity of the portion immediately below 16 has a substantially flat plate shape, it may have any shape.

  The thickness T (see FIG. 12) of the substantially flat plate-shaped portion that overlaps the resin member 12 in the metal member 11 is not particularly limited, and is usually 2 to 10 mm.

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 and aluminum alloys such as 5000 series and 6000 series;
steel;
Magnesium and its alloys;
Titanium and its alloys.

(3) Rotating Tool FIG. 11 is an enlarged view of the tip portion of the rotating tool 16. In FIG. 11, the right half shows the appearance of the rotary tool 16, and the left half shows a cross section. As shown in FIG. 11, the columnar rotary tool 16 has a pin portion 16 a and a shoulder portion 16 b at the distal end portion (lower end portion in FIG. 11). 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 outward (downward in FIG. 11) 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.

(4) One embodiment of the joining method according to the present invention (friction stir welding method)
The method of joining the metal member and the resin member by the friction stir welding method according to the present invention is at least the following steps:
A first step of superimposing the metal member 11 and the resin member 12; and while rotating the rotary tool 16 as the pressing member, the metal member 11 is pressed against the metal member 11 to generate frictional heat. The frictional heat softens the resin member 12 and After melting, the second step of solidifying and joining the metal member 11 and the resin member 12:
Is included.

First step:
In the first step, as shown in FIG. 1, the metal member 11 and the resin member 12 are overlapped at a desired joint portion. Specifically, the metal member 11 and the resin member 12 are overlapped so that the surface of the joint portion 122 of the resin member 12 with the metal member 11 is in contact with the metal member 11.

Second step:
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 joining boundary surface 13 between the metal member 11 and the resin member 12.

In the second step, it is preferable to perform the preheating step C1 in which the rotating tool 16 is rotated in a state where only the front end portion of the rotating tool 16 is in contact with the surface portion of the metal member 11 before the pushing and stirring step. It doesn't have to be done.
After the indentation stirring step, it is preferable to perform the stirring maintenance step C3 in which the rotation operation of the rotary tool 16 is continued at the position where the rotary tool 16 has entered to a depth that does not reach the joining boundary surface. It doesn't have to be.

  Hereinafter, each step will be described in detail. Each process when the convex resin member 12A is used will be described in parallel with reference to FIGS. 12 to 14, and each process when the flat resin member 12B is used will be described with reference to FIGS. To do.

(Preheating process C1)
In the preheating step C1, as shown in FIGS. 12 and 15, only the tip of the rotary tool 16 is placed on the surface portion of the metal member 11 (upper surface 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 state where it is in contact with the part). 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). 12 is a schematic cross-sectional view of the ZZ cross-section in FIG. 1 as viewed in the direction of the arrow, and is a schematic cross-sectional view for explaining a preheating step in the bonding method of the present invention using the convex resin member 12A. It is. FIG. 15 is a schematic cross-sectional view for explaining a preheating step in the joining method of the present invention using the flat resin member 12B.

  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 C1, the frictional heat is also transmitted to the resin member 12 via a joint boundary surface 13 between the metal member 11 and the resin member 12 (hereinafter referred to as including the resin members 12A and 12B). . The frictional heat is transmitted to the inside of the resin member 12, and the range of the region immediately below the pressing region P in the resin member 12 (hereinafter sometimes simply referred to as “region P ′”) and the range in the vicinity of the region P ′ are preheated. The 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 viewpoints of ease of pushing in the rotary tool 16 as described above and from the viewpoints of softening and melting of the resin member 12, and their values. Varies depending on, for example, the rotational speed of the rotary tool 16, the thickness of the metal member 11, the type of material, and the like. For example, when the aluminum alloy metal member 11 having a thickness of 1 mm or more and 2 mm or less is used, the first pressure in the preheating step C1 is 700 N or more and less than 1200 N, and the first pressurizing time is 0.5 seconds or more and 2 A value of less than 0 seconds and a rotation speed of the rotary tool are preferably 500 rpm or more and 10,000 rpm or less.

(Indentation stirring step C2)
The pushing agitation step C2 is a step of pushing the rotating tool 16 into the metal member 11 as shown in FIGS. 13 and 16 by bringing the rotating tool 16 and the receiving member 17 close to each other. When the indentation stirring step C2 is performed after the preheating step C1, the rotary tool 16 and the receiving member 17 are further brought closer to each other, so that the rotary tool 16 is attached to the metal member 11 as shown in FIGS. Push in. Thereby, the rotary tool 16 is advanced to a depth that does not reach the joint boundary surface 13 between the metal member 11 and the resin member 12. At this time, it is preferable to project and deform the lower part 110 of the metal member 11 directly to the resin member 12 side. As a result, the molten resin 121 on the surface of the resin member melted in the region P ′ immediately below the rotary tool at the joint boundary surface 13 can flow to the outer peripheral region of the region P ′ directly below (arrows in FIGS. 13 and 16). direction). FIG. 13 is a schematic cross-sectional view when the ZZ cross section in FIG. 1 is viewed in the direction of the arrow, and shows the indentation stirring process, stirring maintaining process and holding process in the joining method of the present invention using a convex resin member. It is a schematic sectional drawing for demonstrating. FIG. 16 is a schematic cross-sectional view for explaining an indentation stirring process, a stirring maintenance process, and a holding process in the joining method of the present invention using a flat resin member.

  Specifically, in the indentation stirring step C2, the rotary tool 16 is moved at a second pressurizing time (for example, 1500 N) that is larger than the first pressurizing time and shorter than the first pressurizing time (for example, Rotate at a predetermined rotation speed (for example, 3000 rpm) for 0.25 seconds.

  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. Preferably, when the rotary tool 16 is pressed, the joining boundary surface 13 between the metal member 11 and the resin member 12 moves to the support 17 side (lower side in the illustrated example) in the lower portion 110 of the metal member 11. The right lower part 110 projects and deforms toward the resin member 12 side. As a result, the molten resin 121 on the surface of the resin member melted in the region P ′ immediately below the rotary tool at the joining interface 13 flows over the region P ′ immediately below and flows to the outer peripheral region. The molten resin spreads in a substantially circular shape centering on the region P ′ immediately below the rotary tool. As a result, the contact area between the molten resin and the metal member 11 is expanded, and the melted and solidified region (bonding region) formed by solidifying the molten resin by cooling in the obtained bonded body is also expanded. Bonding with the member can be achieved with sufficient strength.

  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 the present invention, in the indentation stirring step C2, the indentation of the rotation tool 16 is stopped when the shoulder portion 16b of the rotation tool 16 enters a depth that does not reach the joining boundary surface. 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, a large amount of frictional heat is transmitted to the resin member 12, and softening, melting, and flow of the resin member 12 are promoted.

  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 varies depending on, for example, the number of rotations of the rotary tool 16, the thickness of the metal member 11, the type of material, and the like. For example, when the aluminum alloy metal member 11 having a thickness of 1 mm or more and 2 mm or less is used, the second pressing force in the indentation stirring step C2 is a value of 1200 N or more and less than 1800 N, and the second pressurizing time is 0.1 second or more. The value of less than 0.5 seconds and the rotation speed of the rotary tool are preferably 500 rpm or more and 10,000 rpm or less.

(Stirring maintenance step C3)
The agitation maintaining step C3 stops the mutual proximity of the rotary tool 16 and the receiving member 17 and, as shown in FIGS. 13 and 16, similarly, the position (this is approached to a depth that does not reach the joint interface 13). Is referred to as “reference position”), and the rotation operation of the rotary tool 16 is continued. In the agitation maintaining step C3, the rotary tool 16 is moved to a third pressurization time (for example, 6.75) longer than the first pressurization time with a third pressurization force (for example, 500 N) smaller than the first pressurization force. Seconds) at a predetermined rotation speed (for example, 3000 rpm).

  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 region P ′ immediately below the pressing 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, the thickness of the metal member 11, the type of material, and the like. For example, when the aluminum alloy metal member 11 having a thickness of 1 mm or more and 2 mm or less is used, the third pressing force in the stirring and maintaining step C3 is preferably a value of 100 N or more and less than 700 N, particularly a value of 100 N or more and 600 N or less. The third pressurizing time is preferably 1.0 to less than 10 seconds, and the rotation speed of the rotary tool is preferably 500 to 10000 rpm.

(Holding process C4)
After the indentation stirring step C2 or the stirring maintaining step C3, a holding step C4 is performed in which the rotation of the rotary tool 16 is stopped and the rotary tool 16 is held at a predetermined pressure for a predetermined pressurizing time. Also good.
Similarly, as shown in FIGS. 13 and 16, the holding step C4 is a step of stopping the rotation of the rotary tool 16 and holding the rotary tool 16 with a predetermined pressure for a predetermined time. 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.

  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 presses the metal member 11 and the resin member 12 in the pressing region P because the applied pressure is smaller than the indentation agitation step C2 but greater than the agitation maintenance step C3. And clamp with the receiving member 17. Thereby, the adhesive force during cooling between the metal member 11 and the resin member 12 is increased, and the bonding strength after the completion of cooling and solidification 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 force at least in the pressing region P ′ during the cooling period as described above, and the values thereof are, for example, the metal member 11 It depends on the type of material. For example, when the aluminum alloy metal member 11 is used, the fourth pressure in the holding step C4 is preferably a value of 700 N or more and less than 1200 N, and the fourth pressurization time is preferably a value of 1 second or more, for example.

  In the present invention, at least through the above-described step C2, preferably through the above-described steps C1 and C2, more preferably through the above-described steps C1 to C3, and then further through step C4 as necessary, finally. As shown in FIGS. 14 and 17, joined bodies 20 </ b> A and 20 </ b> B are obtained in which the metal member 11 and the resin member 12 are joined with high strength without the occurrence of springback.

  After performing a predetermined process in the second step, cooling is usually performed to solidify the molten resin. The cooling method is not particularly limited, and examples thereof include a standing cooling method and air cooling.

  As described above, the case where the metal member and the resin member are joined in a point shape without moving the rotary 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 while being moved (line joining).

<Example 1>
(Resin member)
A convex resin member 12A-1 as shown in FIGS. 4A and 4B was manufactured.
Specifically, as shown in FIG. 4C, first, nylon 66 pellets (Plastotron PA66-CF30) containing 30% by weight of glass fibers having a weight average fiber length of 3 mm and an average fiber diameter of 13 μm as reinforcing fibers are used in the injection machine 150. Manufactured by Daicel Polymer Co., Ltd.) at 280 ° C., and the melt is injected and injected into the molds (40 ° C.) 151A and 151B at an injection speed of 100 mm / second, then cooled and solidified, and the convex resin member 12A-1 Got. The dimensions of the convex resin member 12A-1 were as follows.
R1 (see FIG. 4B); 12 mm;
H (see FIG. 4B); 10 mm;
T1 of the main body portion 124 (see FIG. 4B); 3 mm.
Length of the main body 124; 100 mm;
Next to the main body 124; (width) 100 mm.

  In the convex resin member 12A-1, the orientation degrees y1 / x and y2 / x at a depth of 500 μm and H / 3 from the surface in the tip plane region of the bonding columnar rib 125 were measured by the method described above.

(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. 11 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 metal member 11 and the resin member 12A-1 were overlapped so that the tip flat area of the rib 125 of the resin member 12A-1 was in contact with the metal member 12 (FIG. 1).

Second step:
First, as shown in FIG. 12, the rotary tool 16 was rotated in a state where only the tip portion of the rotary tool 16 was in contact with the surface portion of the metal member 11 (preheating step C1: pressure 900N, pressurization time 1.. 00 seconds, tool rotation speed 3000 rpm). At this time, the center of the tip plane area (circular shape) of the rib 125 in the resin member 12-1 was on the rotation axis of the rotary tool 16.

Thereafter, as shown in FIG. 13, the rotary tool 16 was pushed into the metal member 11 to a depth not reaching the joining boundary surface 13 between the metal member 11 and the resin member 12 </ b> A- 1 (indentation stirring step C <b> 2: pressure force 1500N, pressurization time 0.25 seconds, tool rotation speed 3000 rpm).
Next, as shown in FIG. 13, 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 13 (stirring maintenance step C3: pressurizing force 500 N, pressurization) (Time 6.75 seconds, tool rotation speed 3000 rpm).
Next, as shown in FIG. 14, the rotary tool 16 was extracted from the joined body 20A and allowed to cool.

(Joint strength)
As shown in FIG. 18, the joined body of the metal member 11 and the resin member 12 was placed in the jig 100. The jig 100 is configured such that a downward force acts on the upper end portion of the resin member 12 by pulling the jig 100 downward. By fixing the jig 100 and pulling the metal member 11 upward, a downward force acts on the upper end portion of the resin member 12, and the shear strength of the joint portion is not affected by the strength of the base material of the resin member 12. S was measured.
A: 4.00 ≦ S;
○: 3.00 ≦ S <4.00 (no problem in practical use);
X: S <3.00.

<Example 2>
The resin member and the metal member were joined and evaluated by the same method as in Example 1 except that the resin member 12A-2 produced by the method described below was used.

A convex resin member 12A-2 as shown in FIGS. 5A to 5C was manufactured.
Specifically, first, as shown in FIG. 6, in an injection machine 150, nylon 66 pellets (Plastotron PA66-CF30; Daicel Polymer) containing 30% by weight of glass fibers having a weight average fiber length of 3 mm and an average fiber diameter of 13 μm as reinforcing fibers. The product was melted at 280 ° C., and the melt was injected and injected into the molds (40 ° C.) 151A and 151B at an injection speed of 100 mm / second, and then cooled and solidified to obtain a convex resin member 12A-2. . The dimensions of the convex resin member 12A-2 were as follows.
R1 (see FIG. 5C); 12 mm;
H (see FIG. 5C); 10 mm;
T1 of the main body portion 124; (see FIG. 5C) 3 mm.
Length of the main body 124; 100 mm;
Next to the main body 124; (width) 100 mm;
Width R3 of the dividing ribs 125A and 125B; 2 mm;
Width R4 of groove 126; 1.3 mm;
The depth L3 of the groove part 126; 0.3 mm.

  In the convex resin member 12A-2, the degree of orientation y1 / x and y2 / x at a depth of 500 μm and H / 3 from the surface in the tip plane region of the joining columnar rib 125 was measured by the method described above.

<Example 3>
The resin member and the metal member were joined and evaluated by the same method as in Example 1 except that the resin member 12B-1 produced by the method described below was used.

A flat resin member 12B-1 as shown in FIGS. 7A to 7C was manufactured.
Specifically, first, a convex resin member 12A-1 having the following dimensions is manufactured by the same method as in Example 1, and the convex resin member 12A-1 is preliminarily molded body 127A as shown in FIG. As a result, a flat resin member 12B-1 was obtained by an injection molding method.
Preliminary body 127A:
R1 (see FIG. 4B); 12 mm;
H (see FIG. 4B); 10 mm;
T1 of the main body portion 124; (see FIG. 4B) 3 mm.
Length of the main body 124; 100 mm;
Next to the main body 124; (width) 100 mm.

When manufacturing the flat resin member 12B-1 by the injection molding method using the preformed body 127A, the preformed body 127A was inserted into the molds 151A and 151B as shown in FIG. Next, in the injection machine 150, nylon 66 pellets (Plastotron PA66-CF30; manufactured by Daicel Polymer Co., Ltd.) containing 30% by weight of glass fibers having a weight average fiber length of 3 mm and an average fiber diameter of 13 μm as reinforcing fibers were melted at 280 ° C. The melt was injected and injected into the molds (40 ° C.) 151A and 151B at an injection speed of 100 mm / second, and then cooled and solidified to obtain a flat resin member 12B-1. The dimensions of the flat resin member 12B-1 were as follows.
t2 (= H + t1) (see FIG. 7C and FIG. 4B); 13 mm;
R2 (= R1) (see FIG. 7C and FIG. 4B); 12 mm.

  In the flat resin member 12B-1, the degree of orientation y1 / x and y2 / x at a depth of 500 μm and t2 / 5 from the surface of the joint 122 was measured by the method described above.

<Comparative Example 1>
Except that H was changed to 2 mm, the production of the resin member, the joining of the resin member and the metal member, and the evaluation were performed in the same manner as in Example 1.

<Comparative example 2>
Except that H was changed to 0.8 mm, the resin member was manufactured, the resin member and the metal member were joined, and the evaluation was performed in the same manner as in Example 2.

<Comparative Example 3>
Except that H was changed to 2 mm, the production of the resin member, the joining of the resin member and the metal member, and the evaluation were performed in the same manner as in Example 3.

<Measurement method>
The content of reinforcing fibers, the average fiber length, and the average fiber diameter in the entire resin member and the joint were measured according to the method described above.

  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 12: Resin member 13: Joining interface between metal member and resin member 16: Rotating tool 17: Receiving tool 100: Jig for measuring joint strength 110: Directly below the rotating tool 121 of the metal member: Molten resin melted in the region immediately below the rotating tool

Claims (17)

Heat that achieves bonding after overlapping a metal member and a resin member containing reinforcing fibers, applying heat and pressure by pressing from the metal member side by the pressing member, softening and melting the resin member, and solidifying A method of joining a metal member and a resin member by a pressure joining method,
As the resin member, a resin member having a degree of orientation y1 / x of the reinforcing fiber contained in at least the joint portion with the metal member as described below is used:
1 ≦ y1 / x ≦ 1.3
(Wherein x is the average diameter (μm) of the vertical cross section with respect to the axial direction of the reinforcing fiber; y1 is the average value (μm) of the maximum diameter of the reinforcing fiber in the vertical cross section with respect to the resin member thickness direction of the joint portion) The average value of the maximum diameter in the vertical cross section when the bonded portion is polished from the surface to a depth of 500 μm in the thickness direction). The resin member is a convex resin member having a joining columnar rib, and the width R1 of the joining columnar rib is 0.5 × D1 to 5 × D1 when the width of the pressing member is D1 (mm). Yes,
The joint is a portion from the surface in the tip flat region of the joining rib to the depth L1,
The method for joining a metal member and a resin member according to claim 1, wherein the depth L1 is H / 5 to H when the height of the joining rib is H (mm). The method for joining a metal member and a resin member according to claim 2, wherein the resin member further has an orientation degree y2 / x as shown below:
1 ≦ y2 / x ≦ 1.3
(Wherein x is the average diameter (μm) of the vertical cross section with respect to the axial direction of the reinforcing fiber; y2 is the average value (μm) of the maximum diameter of the reinforcing fiber in the vertical cross section with respect to the resin member thickness direction of the joint portion) When the height of the columnar ribs for bonding is H (mm), the average value of the maximum diameter in the vertical section when the bonding portion is polished from the surface to the depth of H / 3 in the thickness direction). The resin member is a flat resin member;
The joining portion is a portion from the surface in a predetermined joining scheduled region on the surface of the flat resin member to the depth L2,
The method for joining a metal member and a resin member according to claim 1, wherein the depth L2 is t2 / 5 to t2 / 2 when the thickness of the resin member is t2 (mm). The method for joining the metal member and the resin member according to claim 4, wherein the resin member further has an orientation degree y2 / x shown below:
1 ≦ y2 / x ≦ 1.3
(Wherein x is the average diameter (μm) of the vertical cross section with respect to the axial direction of the reinforcing fiber; y2 is the average value (μm) of the maximum diameter of the reinforcing fiber in the vertical cross section with respect to the resin member thickness direction of the joint portion) In addition, when the thickness of the resin member is t2 (mm), the average value of the maximum diameters in the vertical cross section when the joint portion is polished from the surface to the depth of t2 / 5). A first step of superimposing a metal member and a resin member containing reinforcing fibers; and while rotating the rotary tool as the pressing member, the metal member is pressed against the metal member to generate frictional heat, and the frictional heat softens the resin member. A second step of joining the metal member and the resin member by melting and then solidifying;
A method of joining a metal member and a resin member by a friction stir welding method including:
As the resin member, a resin member having a degree of orientation y1 / x of the reinforcing fiber contained in at least the joint portion with the metal member as described below is used:
1 ≦ y1 / x ≦ 1.3
(Wherein x is the average diameter (μm) of the vertical cross section with respect to the axial direction of the reinforcing fiber; y1 is the average value (μm) of the maximum diameter of the reinforcing fiber in the vertical cross section with respect to the resin member thickness direction of the joint portion) The average value of the maximum diameter in the vertical cross section when the bonded portion is polished from the surface to a depth of 500 μm in the thickness direction). The resin member is a convex resin member having a columnar rib for bonding, and the width R1 of the columnar rib for bonding is 0.5 × D1 to 5 × D1 when the diameter of the rotary tool is D1 (mm). Yes,
The joining portion is a portion from the surface in the tip flat region of the joining columnar rib to the depth L1,
The method for joining a metal member and a resin member according to claim 6, wherein the depth L1 is H / 5 to H, where H (mm) is the height of the joining columnar rib. The method for joining a metal member and a resin member according to claim 7, wherein the resin member further has an orientation degree y2 / x shown below:
1 ≦ y2 / x ≦ 1.3
(Wherein x is the average diameter (μm) of the vertical cross section with respect to the axial direction of the reinforcing fiber; y2 is the average value (μm) of the maximum diameter of the reinforcing fiber in the vertical cross section with respect to the resin member thickness direction of the joint portion) When the height of the columnar ribs for bonding is H (mm), the average value of the maximum diameter in the vertical section when the bonding portion is polished from the surface to the depth of H / 3 in the thickness direction). The resin member is a flat resin member;
The joining portion is a portion from the surface to the depth L2 in the joining planned region E on the resin member surface, which is concentric with the pressing region P of the metal member by the rotary tool,
The diameter R2 of the region E is more than D1 and not more than 5 × D1 when the diameter of the rotary tool is D1 (mm).
The method for joining a metal member and a resin member according to claim 6, wherein the depth L2 is t2 / 5 to t2 / 2 when the thickness of the resin member is t2 (mm). The method for joining the metal member and the resin member according to claim 9, wherein the resin member further has an orientation degree y2 / x shown below:
1 ≦ y2 / x ≦ 1.3
(Wherein x is the average diameter (μm) of the vertical cross section with respect to the axial direction of the reinforcing fiber; y2 is the average value (μm) of the maximum diameter of the reinforcing fiber in the vertical cross section with respect to the resin member thickness direction of the joint portion) In addition, when the thickness of the resin member is t2 (mm), the average value of the maximum diameters in the vertical cross section when the joint portion is polished from the surface to the depth of t2 / 5).   The metal according to any one of claims 6 to 10, wherein the second step includes a pressing and stirring step of pressing the rotary tool into the metal member to enter a depth that does not reach the joining interface between the metal member and the resin member. A method of joining a member and a resin member.   The said 2nd step is further equipped with the pre-heating process which rotates the said rotation tool in the state which made the front-end | tip part of a rotation tool contact the surface part of a metal member before an indentation stirring process. A method of joining a metal member and a resin member. In the preheating step, the rotary tool is rotated by a first pressurizing time while being pressed with a first pressing force,
13. The rotation according to claim 12, wherein, in the indentation stirring step, the rotary 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 metal member and a resin member. 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,
The said stirring maintenance process WHEREIN: The said rotating tool is rotated only for the 3rd pressurization time longer than the said 1st pressurization time, pressing with the 3rd pressurization force smaller than the said 1st pressurization force. A method of joining a metal member and a resin member.   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 the state. 14. A method for joining the metal member and the resin member according to 14.   The reinforcing fiber contained in the joint part in the resin member has an average fiber length of 1 to 50 mm and an average fiber diameter of 2 to 20 μm, and the amount of the reinforcing fiber contained in the joint part is based on the total amount of the joint part. It is 10 to 50 weight%, The joining method of the metal member and resin member in any one of Claims 1-15.   The resin member used in the joining method of the metal member and resin member in any one of Claims 1-16.

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