JP6314935B2 - 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.

  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. 10, 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.

JP 2010-158885 A

  However, in the conventional friction stir welding method, when a resin member containing reinforcing fibers 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. 11A, the pressing member 216 is pushed into the metal member 211, and the region 221 directly 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, springback occurred in the melted and solidified region of the resin member 212. 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. 11B, bubbles are mixed in the melt-solidified region of the resin member 212, and a bubble layer (springback layer) 222 that appears to be foamed apparently. It is considered that the bonding strength is reduced by the formation of the fracture within the air envelope layer 222 having a low strength.

  The present invention provides a method for joining a metal member and a resin member, which can achieve joining of the resin member and the metal member with sufficient strength even when the reinforcing fiber is contained in the resin member. With the goal.

The present invention
The metal member and the resin member containing the reinforcing fiber are overlapped, pressure is applied to the resin member by pressing from the metal member side by the pressing member, and the resin member is softened and melted by heat, and then solidified and bonded. A method of joining a metal member and a resin member by a hot-pressure joining method,
The present invention relates to a method for joining a metal member and a resin member, wherein the reinforcing fiber is shortened during the joining.

The present invention also provides
A first step of superimposing the metal member and the resin member; and, while rotating the rotary tool as the pressing member, pressing the metal member to generate frictional heat, and softening and melting the resin member by this frictional heat, A method of joining a metal member and a resin member by a friction stir welding method including a second step of solidifying and joining the metal member and the resin member,
The present invention relates to a method for joining a metal member and a resin member, wherein the reinforcing fiber is shortened during the joining.

  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. 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 initial stage of the indentation stirring process in the 1st embodiment of this invention. It is a schematic sectional drawing for demonstrating an example of the last step of the indentation stirring process in the 1st embodiment of this invention. It is a schematic sectional drawing for demonstrating an example of the initial stage of the indentation stirring process in the 2nd embodiment of this invention. It is a schematic sectional drawing for demonstrating an example of the last step of the indentation stirring process in the 2nd embodiment of this invention. (A) is a schematic sketch of the uniaxial fiber cutting projection that can be formed on the metal member usable in the second embodiment of the present invention, and (B) is a metal member usable in the second embodiment of the present invention. It is a schematic outline drawing of the projection part for biaxial fiber cutting which can be formed in. It is a schematic diagram which shows the surface state of the resin member when a metal member is forcedly peeled from the joining body obtained by the joining method of this invention, and the metal member side surface of the resin member is observed. 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, a metal member and a resin member are overlapped, pressure is applied to the resin member by pressing from the metal member side by the pressing member, and the resin member is softened and melted by heat and then solidified. This is a hot-pressure joining method for joining a metal member and a resin member. Heat and pressure are preferably applied locally. The hot-pressure bonding method of the present invention is a method of applying heat by a pressing member or another means while applying pressure by the pressing member. The hot-pressure bonding method is not particularly limited as long as it is a method capable of shortening the reinforcing fibers contained in the resin member during the bonding by the method described later. For example, the friction stir welding method, An ultrasonic heating bonding method, a laser heating bonding method, a resistance heating bonding method, an induction heating bonding method, or the like may be used. Preferably, it is a method in which heat and pressure are locally applied from the metal member side by a pressing member, and a friction stir welding method is more preferably employed.

  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 heat bonding method is a resin member / metal member produced by superposing a metal member and a resin member, causing ultrasonic vibrations to the pressing member and the metal member while pressing the metal member with the pressing member, and the vibration. 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 bonding method is a method in which a metal member and a resin member are overlapped, and heat is generated by irradiating the metal member with a laser in a state in which the metal member and the resin member are constrained by pressurization by the pressing member. In this method, the metal member and the resin member are joined after being softened and melted and then solidified. 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 in which a metal member and a resin member are overlapped and bonded using heat generated by flowing a current directly through the metal member in a state in which the metal member and the resin member are constrained by pressure applied by the pressing member. .

  The induction heating joining method is a method in which a metal member and a resin member are overlapped, and an induction current is generated in the metal member by electromagnetic induction while the metal member and the resin member are constrained by pressure applied by the pressing member, and heat generated by the current is used. And joining them.

  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 fiber shortening described later is performed, the effects of the present invention can be obtained even if other joining methods described above are used. It is clear that It should be noted that the various elements shown in the drawings are merely schematically shown for understanding of the present invention, and the dimensional ratio, appearance, and the like may differ from the actual ones. The “vertical direction” used directly or indirectly in this specification corresponds to a direction corresponding to the vertical direction in the drawing. Unless otherwise specified, in these drawings, common reference numerals indicate the same members, parts, dimensions, or regions.

[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.

(1) Joining Device First, FIG. 1 is a diagram schematically showing an example of a part of a friction stir welding device 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 for friction stir welding a metal member 11 and a resin member 12, and includes a columnar rotary tool 16 as a pressing member.

  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. 2), it moves downward as indicated by an arrow A2. At this time, the rotary tool 16 applies pressure in the pressing region P (scheduled pressing region) on the surface of the metal member 11. 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. 2 is an enlarged view of the distal end portion of the rotary tool 16. In FIG. 2, the right half shows the appearance of the rotary tool 16, and the left half shows a cross section. As shown in FIG. 2, 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. 2). 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. 2) 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) or the like, 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.

  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.

(2) Joining method The joining method of 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, the metal member 11 is pressed to generate frictional heat, and the resin member 12 is softened and melted by the frictional heat. Then, the second step of solidifying and joining the metal member 11 and the resin member 12:
Is included.

  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.

  In the second step, the rotary tool 16 is pushed into the metal member 11 and at least the pushing agitation process for entering the inside of the metal member 11 and the rotation operation of the rotary tool is continued at the position where the rotary tool is entered in the pushing agitation process. A stirring maintaining step.

  In the present invention, the reinforcing fibers contained in the resin member 12 are shortened during bonding. “Being joined” means any time from when the metal member 11 and the resin member 12 are overlapped to when the metal member 11 and the resin member 12 are joined by solidification. The shortening of the fibers is preferably performed in the second step, particularly in one or both of the indentation stirring process and the stirring maintenance process.

  The shortening of the fiber may be performed at least on the surface layer portion 121 (see FIGS. 3 to 6) in the region immediately below the rotary tool on the metal member side surface of the resin member 12. The region directly under the rotary tool is a region on the surface of the resin member 12 corresponding to the region immediately below the pressing region P (see FIG. 1) of the rotary tool 16 on the surface of the metal member 11 when the metal member 11 and the resin member 12 are overlapped. It is an area.

  As shown in FIG. 8, which will be described later, at least the surface layer portion 121 of the region 60 directly below the rotary tool 60 on the metal member side surface 120 of the resin member 12 melts and flows into the outer peripheral region. And then solidified. In the present invention, at least in such a surface layer portion 121, the reinforcing fiber is shortened during bonding, and the reinforcing fiber whose degree of curvature is relaxed flows to the outer peripheral region together with the molten resin. The formation of the springback layer is sufficiently prevented at the interface 13 with 12. If the reinforcing fiber is not shortened in the surface layer portion, the degree of the relatively large curvature of the reinforcing fiber is not relaxed, so that the formation of the springback layer cannot be sufficiently prevented and the bonding strength is lowered. FIG. 8 is a schematic diagram showing the surface state of the resin member when the metal member is forcibly separated from the joined body obtained by the joining method of the present invention and the metal member side surface of the resin member is observed.

  The thickness of the surface layer portion 121 where the shortening is performed cannot be strictly defined from the viewpoint of the flow to the outer peripheral region due to the melting of the surface layer portion, but, as will be described later, It is sufficient that the resin member has a thickness such that shortening is achieved in the outer peripheral region immediately below the rotary tool.

  The shortening of the reinforcing fiber may be achieved by any method as long as it is performed during joining, and is usually performed by a shearing force caused by a rotating tool (pressing member). The shearing force caused by the rotating tool is a shearing force generated by the operation of the rotating tool, and includes, for example, the shearing force caused by the rotating force and / or the pressing force of the rotating tool.

The following method (I) is mentioned as a method for shortening the fiber by the shearing force resulting from the rotational force of the rotating tool:
Method (I): A method in which the rotary tool 16 is pushed into the metal member 11 to enter the interface 13 between the metal member 11 and the resin member 12, and the surface of the resin member 12 is heated and stirred.

The following method (II) is mentioned as a method for shortening the fiber by the shearing force caused by the pressing force of the rotary tool:
Method (II): A method in which the fiber cutting projection 50 of the metal member 11 is stuck to the resin member 12 by the initial pressing with the rotary tool 16.

  From the viewpoint of shortening the fiber, the method (II) is more reliable than the method (I). A method (III) in which the method (I) and the method (II) are combined and the fiber is shortened by a shearing force resulting from the rotational force and pressing force of the rotary tool may be employed.

  The above methods (I) to (II) will be described in detail below in the first and second embodiments. As will be described later, in the first embodiment, the shortening is performed in the stirring maintaining step. In the second embodiment, the shortening is performed in the indentation stirring step.

<First Embodiment>
In the present embodiment, in the indentation stirring step A1, as shown in FIGS. 3 and 4, the rotary tool 16 is pushed into the metal member 11 while being rotated, and enters the interface 13 between the metal member 11 and the resin member 12. . Thereby, the rotation tool right lower part 110 of the metal member 11 is isolate | separated. FIG. 3 is a schematic cross-sectional view for explaining an example of the initial stage of the indentation stirring process in the first embodiment. FIG. 4 is a schematic cross-sectional view for explaining an example of the final stage of the indentation stirring process in the first embodiment.

  In this embodiment, after the indentation stirring step A1, an agitation maintaining step A2 in which the rotation operation of the rotation tool 16 is continued at the position where the rotation tool 16 is entered in the indentation stirring step A1. As a result, as described later in detail, the surface of the resin member 12 is agitated because the portion 110 directly below the rotary tool of the metal member 11 separated in the indentation agitation step A1 also rotates. As a result, the fiber shortening is achieved by applying a shearing force directly to the reinforcing fibers contained in the resin member 12.

  Each step in this embodiment may be performed by a pressure control system that controls the pressing force (pressing force) and pressing time of the rotary tool, or the amount of insertion of the rotating tool in the pressing direction (after contacting the metal member) The amount of the metal member inserted into the metal member) and the position control method for controlling the movement time thereof, or a combination thereof may be used.

  Hereafter, the process of this embodiment is demonstrated in detail.

(Indentation stirring step A1)
In the indentation stirring step A1, as shown in FIG. 3, the rotary tool 16 and the receiving member 17 are brought close to each other to push the rotary tool 16 into the metal member 11 while rotating, and as a result, as shown in FIG. Then, the metal member 11 and the resin member 12 are made to enter the interface 13. In this specification, when the rotary tool 16 enters the interface 13 between the metal member 11 and the resin member 12, the outer peripheral portion of the shoulder portion 16b at the tip of the rotary tool 16 extends to the interface 13 as shown in FIG. It means to enter.

  Specifically, when the rotary tool 16 is pushed in, the joint boundary surface 13 between the metal member 11 and the resin member 12 moves to the receiving member 17 side (lower side in the example) in the lower part 110 of the metal member 11. The right lower part 110 projects and deforms toward the resin member 12 side. Thereafter, when the rotary tool 16 is further pushed into the metal member 11, as shown in FIG. 4, the outer peripheral portion of the shoulder portion 16 b at the tip of the rotary tool 16 reaches the interface 13, and the lower portion 110 of the metal member 11 directly below the rotary tool 110. Separated from the metal member 11.

  The insertion amount of the rotary tool 16 may be in the vicinity of T when the thickness of the metal member 11 is T (mm), and preferably T to T + 0. 5 (mm). In this specification, the amount of insertion of the rotary tool 16 is the amount of insertion in the thickness direction from the metal member surface of the outer peripheral portion of the shoulder portion 16b of the rotary tool 16. The insertion amount of the rotary tool 16 can be controlled more precisely by using a position (insertion amount) control device for the rotary tool.

  In the indentation stirring step A1, as described above, after the rotary tool 16 has entered the interface 13 between the metal member 11 and the resin member 12, and the lower part 110 directly below the rotary tool of the metal member 11 is projected and deformed toward the resin member 12 side. The metal member 11 is separated. For this reason, in this embodiment, the area directly under the rotary tool at the interface 13 between the metal member 11 and the resin member 12 hardly contributes to the bonding between the metal member 11 and the resin member 12. However, in the agitation maintaining step A2, which will be described later, while the shortening of the reinforcing fiber is performed, the generated frictional heat melts at least the surface layer portion 121 in the region immediately below the rotary tool in the resin member 12, exceeding the region immediately below. It flows to the outer peripheral area (arrow direction in FIG. 4). At this time, the molten resin spreads in a substantially circular shape centering on the region directly under the rotary tool. For this reason, in this embodiment, the joining of the resin member and the metal member can be achieved with sufficient strength only in the outer peripheral region of the region immediately below the rotary tool at the interface 13 between the metal member 11 and the resin member 12.

  In the case where this step is performed by the position control method, the tool insertion amount and the insertion speed or the insertion time in the indentation stirring step A1 may be controlled so that the insertion amount is achieved.

  In the case where this step is performed by the pressure control method, in the indentation stirring step A1, the rotary tool 16 is rotated at a predetermined rotation speed for the first pressurizing time with the first pressurizing force. The first pressurizing force and the first pressurizing time in the indentation stirring step A1 may be controlled so that the insertion amount is achieved also in this method, and the rotary tool 16 is replaced with the metal member 11 and the resin member 12. The value is set from the viewpoint of approaching to the interface 13, and the value varies depending on, for example, the number of rotations of the rotary tool 16, the thickness of the metal member 11, and the type of material. 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 applied pressure in the indentation stirring step A1 is preferably a value of 1200 N or more and less than 1800 N. The first pressurization time is preferably 0.1 seconds or more and less than 3 seconds. The number of rotations of the rotary tool is preferably 2000 rpm or more and 4000 rpm or less.

(Stirring maintenance step A2)
In the stirring maintaining step A2, by stopping the mutual proximity of the rotating tool 16 and the receiving member 17, similarly as shown in FIG. 4, the rotating tool 16 is moved into the position where the rotating tool 16 is advanced in the push-in stirring step A1. This is a step of continuing the rotation operation.

  In such an agitation maintaining step A2, the rotary tool 16 is substantially maintained at the position entered in the indentation agitation step A1, and the lower part 110 of the metal member 11 separated in the indentation agitation step A1 is rotated. . Thereby, the reinforcing fiber is cut in order that the immediately lower part 110 rubs the surface of the surface layer part 121 in the region immediately below the rotary tool in the resin member 12 and applies a shearing force to the reinforcing fiber included in the resin member 12. As a result, shortening of the reinforcing fiber is achieved. In this step, a large amount of frictional heat is generated, and most of the generated frictional heat moves to the resin member 12. Therefore, at least the surface layer portion 121 in the region immediately below the rotary tool in the resin member 12 melts and flows over the region directly below to the outer peripheral region (in the direction of the arrow in FIG. 4). The molten resin spreads in a substantially circular shape centering on the region directly under the rotary tool.

  When this process is performed by the position control method, the tool insertion amount and the insertion speed or the insertion time in the stirring maintenance process A2 are not particularly limited as long as the rotation operation is continued at the above position.

  In the case where this process is performed by the pressure control method, in the stirring maintenance process A2, the rotary tool 16 is rotated at the predetermined rotation speed for the second pressurizing time with the second pressurizing force. The second pressing force and the second pressurizing time are set from the viewpoints of sufficiently shortening the reinforcing fiber as described above, sufficiently softening / melting the resin member 12 in a wide range, and productivity. 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 stirring maintenance step A2 is preferably a value of 100 N or more and less than 700 N. The second pressurization time is preferably 1.0 to 20 seconds, particularly preferably 3.0 to 10 seconds. The number of rotations of the rotary tool is preferably 2000 rpm or more and 4000 rpm or less.

  In the present embodiment, the preheating step A0 for rotating the rotary tool 16 in a state where only the tip portion of the rotary tool 16 is in contact with the surface portion of the metal member 11 may be performed before the pushing and stirring step A1.

(Preheating step A0)
In the preheating step A0, by bringing the rotary tool 16 and the receiving member 17 close to each other, as shown in FIG. 3, only the tip of the rotary tool 16 is placed on the surface portion (upper surface portion in the illustrated example) of the metal member 11. This is a step of rotating the rotary tool 16 in a contacted state.

  Specifically, in the preheating step A0, frictional heat is generated on the surface portion (upper surface portion in the illustrated example) of the metal member 11 by the 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 area 111 (the pressing area by the rotary tool 16) of the metal member 11 and the area near the pressing area 111 are preheated. Thereby, it becomes easy to push the rotary tool 16 into the metal member 11 in the next pushing and stirring step A1.

  When this step is performed by the position control method, the tool insertion amount and insertion speed or insertion time in the preheating step A0 are rotated with only the tip portion of the rotary tool 16 in contact with the surface portion of the metal member 11. There is no particular limitation as long as the tool 16 can be rotated.

  In the case where this process is performed by the pressure control method, the pressurizing force and pressurizing time of the preheating process A0 are set from the viewpoint of ease of pushing in the rotary tool 16 as described above, from the viewpoint of productivity, and the values thereof are: For example, it changes depending on the number of rotations of the rotary tool 16, the thickness of the metal member 11, and the type of material. 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 pressure applied in the preheating step A0 is preferably a value of 500 N or more and less than 1000 N. The pressurization time is preferably a value of 0.1 seconds or more and less than 3.0 seconds. The number of rotations of the rotary tool is preferably 2000 rpm or more and 4000 rpm or less.

(Resin member)
The resin member 12 used in this embodiment includes a thermoplastic polymer and reinforcing fibers.

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 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 resin, particularly polypropylene, which is inexpensive and excellent in mechanical properties is 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.

  The resin member 12 has a substantially flat plate shape as an overall shape in FIG. 1 and the like, but is not limited to this. When the resin member 12 is overlapped with the metal member 11 for bonding, the resin member 12 is directly below the metal member 11. As long as the portion has a substantially flat plate shape, it may have any shape. The part immediately below the metal member 11 in the resin member 12 is generally composed of a flat surface on both sides.

  The thickness t (thickness before joining treatment; see FIGS. 3 and 5) of the portion immediately below the metal member 11 in the resin member 12 is usually 2 to 10 mm, particularly 2 to 5 mm, but is not limited thereto.

  In the field of polymer-containing composite materials, the reinforcing fibers contained in the resin member 12 are fibers that are uniformly contained and dispersed in the polymer in order to improve strength, and are generally large in continuous fibers and discontinuous fibers. Although different, the reinforcing fiber in the present invention shall mean a discontinuous fiber. This is because discontinuous fibers are considered to be prone to spring back, and in the present invention, even when such discontinuous fibers are contained, spring back can be sufficiently prevented.

The reinforcing fibers in the resin member, is contained in a random orientation form, the average fiber length _{L B} is typically, less than 50mm, especially 1mm super 50mm or less, preferably 1mm super 30mm or less. The average fiber diameter of the reinforcing fibers is not particularly limited, and is, for example, 2 to 20 μm, preferably 6 to 15 μm. The type of reinforcing fiber is not particularly limited, and examples thereof include carbon fiber and glass fiber.

  The content of the reinforcing fiber is usually 1% by weight or more, particularly 10 to 50% by weight, preferably 20 to 50% by weight, more preferably 30 to 50% by weight, based on the total amount of the resin member.

  As the content of the reinforcing fiber, a value based on the amount of each material used at the time of manufacturing the resin member can be used, and a value measured by the following method can also be used. First, a resin member or a part (sample) thereof is heated by an electric furnace or the like at a temperature not lower than the decomposition temperature of the thermoplastic polymer (resin component) and not higher than the decomposition temperature of the reinforcing fiber, thereby removing the thermoplastic polymer and reinforcing fiber. Take out only. At this time, only the reinforcing fiber can be taken out by dissolving the resin member or a part (sample) thereof in a solvent in which the thermoplastic polymer can be dissolved and filtering the reinforcing fiber. By measuring the weight before and after heating or before and after dissolution, the content of reinforcing fibers can be calculated as a ratio to the weight of the sample. Alternatively, the content can be measured by measuring the specific gravity.

  The resin member 12 may further contain additives other than reinforcing fibers, such as stabilizers, flame retardants, colorants, foaming agents, and the like.

  The resin member 12 can be manufactured by subjecting a mixture containing a thermoplastic polymer and reinforcing fibers and a desired additive to a molding method such as an injection molding method or a press molding method.

The melting point Tm of the resin member 12 varies depending on the type of the resin member 12, and is usually 130 to 350 ° C.
As the melting point Tm of the resin member 12, a value measured according to JIS 7121 is used.

(Metal member)
The metal member 11 used in the present embodiment has a substantially flat plate shape as a whole in FIG. 1 and the like, but is not limited to this, and at least a portion overlapping with the resin member 12 is a substantially flat plate. As long as it has a shape, it may have any shape. The part of the metal member 11 that overlaps with the resin member 12 is generally composed of a flat surface on both sides.

  The thickness T (thickness before joining treatment; see FIGS. 3 and 5) of the substantially flat plate-shaped portion that is superimposed on 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.

<Second Embodiment>
In the present embodiment, as shown in FIG. 5, the metal member 11 having the fiber cutting projection 50 on the resin member side surface is used, and the fiber of the metal member 11 is initially pressed by the rotary tool 16 in the indentation stirring step B1. The cutting projection 50 is stuck to the resin member 12. Thereby, shortening is achieved. FIG. 5 is a schematic cross-sectional view for explaining an example of the initial stage of the indentation stirring process in the second embodiment.

  In the present embodiment, it is preferable to perform the stirring maintaining step B2 in which the rotating operation of the rotating tool 16 is continued at the position where the rotating tool 16 is entered in the pressing stirring step B1 after the pressing stirring step B1. The process does not necessarily have to be performed.

  Each step in this embodiment may be performed by a pressure control system that controls the pressing force (pressing force) and pressing time of the rotating tool, or the amount of insertion of the rotating tool in the pressing direction (after contact with the metal member) It may be made by a position control system for controlling the amount of insertion into the metal member) and its moving time, or a combination thereof.

  Hereafter, the process of this embodiment is demonstrated in detail.

(Indentation stirring step B1)
In the indentation stirring step B1, as shown in FIG. 5, the fiber cutting projection 50 of the metal member 11 is first stabbed into the resin member 12 by bringing the rotary tool 16 and the receiving member 17 close to each other. In this way, due to the pressing force of the rotary tool, the reinforcing fiber is cut in order to apply a shearing force to the reinforcing fiber, and as a result, shortening of the reinforcing fiber is achieved. Thereafter, the rotating tool 16 and the receiving member 17 are further brought close to each other, thereby pushing the rotating tool 16 into the metal member 11 as shown in FIG. 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 that the lower part 110 of the metal member 11 is protruded and deformed toward the resin member 12 as shown in FIG. For this reason, at least the surface layer portion 121 of the resin member 12 in the region immediately below the rotating tool is melted by the generated frictional heat, and flows to the outer peripheral region beyond the region immediately below the region (in the arrow direction in FIG. 6). FIG. 6 is a schematic cross-sectional view for explaining an example of the final stage of the indentation stirring process in the second embodiment.

  When this process is performed by the position control method, the insertion amount of the rotary tool 16 is usually 0.2 × T to 0.9 × T, where the thickness of the metal member 11 is T (mm), Preferably, it is 0.5 × T to 0.8 × T (mm).

  In the case where this process is performed by the pressure control method, in the indentation stirring process B1, the rotary tool 16 is rotated at a predetermined rotation speed with a first pressurizing force for a first pressurizing time. The first pressurizing force and the first pressurizing time in the indentation stirring step B1 are set from the viewpoint of causing the rotary tool 16 to reach a depth that does not reach the interface 13 between the metal member 11 and the resin member 12, and the values thereof are: For example, it changes depending on the number of rotations of the rotary tool 16, the thickness of the metal member 11, and the type of material. 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 applied pressure in the indentation stirring step B1 is preferably a value of 1200 N or more and less than 1800 N. The first pressurization time is preferably 0.1 seconds or more and less than 3 seconds. The number of rotations of the rotary tool is preferably 2000 rpm or more and 4000 rpm or less.

(Stirring maintenance step B2)
In the stirring maintaining process B2, by stopping the mutual proximity of the rotating tool 16 and the receiving member 17, as shown in FIG. 6, the rotating tool 16 is moved to the position where the rotating tool 16 is moved in the indenting stirring process B1. This is a step of continuing the rotation operation.

  In such a stirring maintaining step B2, the rotary tool 16 is substantially maintained at the position entered in the indenting stirring step B1. In this step, a large amount of frictional heat is generated, and most of the generated frictional heat moves to the resin member 12. Therefore, at least the surface layer portion 121 in the region immediately below the rotary tool in the resin member 12 melts and flows to the outer peripheral region beyond the region immediately below the region (in the arrow direction in FIG. 6). The molten resin spreads in a substantially circular shape centering on the region directly under the rotary tool. As a result, in this embodiment, the bonding between the resin member and the metal member can be achieved with sufficient strength in the region immediately below the rotary tool and the outer peripheral region at the interface 13 between the metal member 11 and the resin member 12.

  When this process is performed by the position control method, the tool insertion amount and the insertion speed or the insertion time in the stirring maintenance process B2 are not particularly limited as long as the rotation operation is continued at the above position.

  In the case where this process is performed by the pressure control method, in the stirring maintenance process B2, the rotary tool 16 is rotated at the predetermined rotation speed for the second pressurizing time with the second pressurizing force. The second pressurizing force and the second pressurizing time in the stirring maintaining step B2 are set from the viewpoint of sufficient softening / melting and productivity in a wide range of the resin member 12 as described above, and the values thereof are, for example, It changes depending on 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 applied pressure in the stirring and maintaining step B2 is preferably a value of 100 N or more and less than 700 N. The second pressurization time is preferably 1.0 to 20 seconds, particularly preferably 3.0 to 10 seconds. The number of rotations of the rotary tool is preferably 2000 rpm or more and 4000 rpm or less.

(Holding process B3)
After the agitation maintaining step B2, the rotation of the rotary tool 16 may be stopped, and in that state, a holding step B3 for holding the rotary tool 16 for a predetermined pressurizing time with a predetermined pressure may be performed. It is not necessary.
Similarly, as shown in FIG. 6, the holding step B <b> 3 is a step in which the rotation of the rotary tool 16 is stopped and the rotary tool 16 is held for a third time with the third pressure in that state. In the holding step B3, when the rotation of the rotary tool 16 is stopped, the generation of frictional heat is completed, and cooling of the workpiece 10 is started. 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 third pressing force and the third pressurizing time in the holding step B3 are set from the viewpoint of improving the adhesion between the metal member 11 and the resin member 12 during the cooling period as described above. It varies depending on the type of material of the member 11 and the like. For example, when the aluminum alloy metal member 11 is used, the third pressing force in the holding step A3 is preferably a value of 700 N or more and less than 1200 N, for example. The third pressurizing time is preferably, for example, a value of 1 second or longer.

  In the present embodiment, a preheating step B0 in which the rotating tool 16 is rotated in a state where only the tip portion of the rotating tool 16 is in contact with the surface portion of the metal member 11 may be performed before the pushing and stirring step B1. If the preheating step B0 is performed, the shortening of the fiber by the fiber cutting projection 50 formed on the metal member 11 is completed during either the preheating step B0 or the indentation stirring step B1.

(Preheating process B0)
In the preheating step B0, by bringing the rotary tool 16 and the receiving member 17 close to each other, as shown in FIG. 5, only the tip of the rotary tool 16 is placed on the surface portion (upper surface portion in the illustrated example) of the metal member 11. This is a step of rotating the rotary tool 16 in a contacted state. Specifically, in the preheating step B0, frictional heat is generated on the surface portion (upper surface portion in the illustrated example) of the metal member 11 by the 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 area 111 (the pressing area by the rotary tool 16) of the metal member 11 and the area near the pressing area 111 are preheated. Thereby, it becomes easy to push the rotary tool 16 into the metal member 11 in the next pushing and stirring step B1.

  The preheating step B0 in this embodiment is the same as the preheating step A0 in the first embodiment. Since the explanation of the pressure and pressurization time in the preheating step B0 is the same as the explanation of the pressure and pressurization time in the preheating step A0, detailed explanation thereof will be omitted.

(Resin member)
The resin member 12 used in this embodiment is the same as the resin member 12 used in the first embodiment.

(Metal member)
The metal member 11 used in the present embodiment is the same as the metal member 11 used in the first embodiment, except that the fiber member protruding surface 50 is provided on the resin member side surface in the portion overlapping the resin member 12. is there. For example, a metal member 11 having a fiber cutting projection 50 as shown in FIG. 5 is used.

  The fiber cutting projection 50 is a reinforcing fiber cutting means capable of cutting the reinforcing fiber by impinging on the surface layer portion 121 in the region immediately below the rotary tool in the resin member 12. For example, a so-called cutter, particularly a lattice cutter is used. Is done.

  The overall shape of the fiber cutting projection 50 may be any shape as long as the average fiber length after shortening is within a predetermined range. For example, the uniaxial projection 501 as shown in FIG. Alternatively, it may be a biaxial protrusion 502 in which two axes are orthogonal to each other as shown in FIG. In the case of using the uniaxial protrusion 501, it is preferable to use a resin material having a high degree of fiber orientation, and to apply the protrusion so that the axial direction of the protrusion is perpendicular to the orientation direction. .

The pitch of the protrusions 50 (for example, x in FIG. 7A, x1 and x2 in FIG. 7B) is usually 0.1 to 1 mm, preferably 0.3 to 0.8 mm. The narrower the pitch, the shorter the average fiber length after shortening.
The height of the protrusion 50 (for example, y in FIG. 7A and y1 and y2 in FIG. 7B) is usually 0.3 to 2 mm, preferably 0.5 to 1 mm.
The apex angle of the protrusion 50 is not particularly limited as long as the reinforcing fiber can be cut, and is usually 30 ° or less.

  The protrusion 50 may be formed at least in the region immediately below the rotary tool on the resin member side surface of the metal member 11.

  The protrusion 50 may be formed integrally with the metal member 11 or fixed as a separate member to the metal member 11 in a predetermined region on the surface of the metal member 11 on the resin member side. May be formed.

  When forming the protrusion 50 integrally with the metal member 11, the protrusion 50 may be formed by any method, for example, by pressing the metal member 11 with a mold corresponding to a desired shape. Is possible.

  As a constituent material of the protrusion 50, for example, a constituent metal similar to the metal member 11 can be used.

  As described above, in each embodiment, the case where the metal member and the resin member are joined in a spot shape (point joining) without moving the rotary tool in the surface direction on the surface of the metal member 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 moving the rotary tool in the direction.

(3) Bonded Body The bonded body of the metal member 11 and the resin member 12 bonded by the bonding method of the present invention has been bonded at least in the outer peripheral region of the bonding boundary surface 13 immediately below the rotary tool.

Specifically, in the joined body in the first embodiment, joining is achieved only in the outer peripheral region of the region immediately below the rotary tool on the joining boundary surface.
In the joined body in the second embodiment, the joining is achieved in the region immediately below the rotary tool and the outer peripheral region on the joining boundary surface.

  These can be detected by confirming a melt-solidified region formed by solidification of the molten resin on the metal member-side surface 120 of the resin member 12 and confirming separation of the lower part 110 immediately below the rotary tool in the metal member. .

Specifically, when the metal member 11 is forcibly separated from the joined body, for example, the metal member side surface 120 of the resin member 12 as shown in FIG. 8 can be observed.
For example, in the case of the joined body of the second embodiment, on the metal member side surface 120 of the resin member 12, a melt-solidified region is formed in the region 60 (shaded region) directly below the rotating tool and the outer peripheral region 61 (lattice region). Moreover, the lower part 110 of the metal member 11 is not separated. For this reason, it is clear that both the region 60 (shaded region) directly below the rotating tool and the outer peripheral region 61 contribute to the joining.

  Further, for example, in the case of the joined body of the first embodiment as well, in the same manner as the joined body of the second embodiment, on the metal member side surface 120 of the resin member 12, the melt-solidified region is the region 60 (shaded region) directly below the rotary tool It is formed in the outer peripheral area 61 (lattice area). However, the lower part 110 of the metal member 11 is separated. For this reason, it is clear that only the outer peripheral region 61 of the region 60 (shaded region) immediately below the rotating tool contributes to the joining.

  As shown in FIG. 8, the melted and solidified regions 60 (hatched region) and 61 (lattice region) are regions formed by melting and solidifying the resin member 12 at the time of joining, and are on the metal member side of the resin member 12. This is a region where there is a step (a step of several microns) that can be visually discriminated on the outer periphery of the melt-solidified region with respect to the region 122 where the surface 120 is not melted. In such a melt-solidified region, the surface of the corresponding region in the metal member is transferred, or the melt-solidified resin adheres to the metal member side surface entirely or partially by breaking inside the melt-solidified resin layer. It will be in the state.

The joined body of the present invention satisfies the following relationship when the diameter of the melt-solidified region (60, 61) is R (mm) and the diameter of the rotary tool is D1 (mm):
1 <R / D1 ≦ 5;
Preferably 2 ≦ R / D1 ≦ 5;
More preferably, 3 ≦ R / D1 ≦ 5.
If R / D1 is too small, the bonding strength is not sufficient.

  The diameter R in the melt-solidified region (60, 61) can be easily measured based on the step on the outer periphery of the melt-solidified region on the metal member side surface 120 of the resin member 12. The diameter R is the maximum dimension of the melt-solidified region (60, 61).

  In the joined body that has been joined by the method of the present invention, shortening of the fiber length is achieved in the outer peripheral region 61 of the region 60 directly below the rotary tool. Specifically, as shown in FIG. 8, shortening of fibers is achieved in the donut-shaped region 121 </ b> C on the metal member side surface 120 of the resin member 12. The donut-shaped region 121C is a region obtained by removing the region 60 directly below the rotary tool from the circular region 62 (broken line) having a diameter of at least 1.5 × D1 concentric with the region 60 directly below the rotary tool (diameter D1 (mm)). It is. It is sufficient that the shortening of the fiber is achieved in the surface layer portion having a thickness (depth) of at least 0.1 mm, preferably at least 0.5 mm, more preferably at least 1 mm from the surface in the donut-shaped region 121C.

The average fiber length L _A of the short fiberized reinforcing _fibers, i.e. at least toroidal region 121C average fiber length of the reinforcing fibers contained in the surface layer portion of the thickness in L _A, typically, 1 mm or less (0 mm is not included) is there.

(Other embodiments)
In the present invention, even if the shortening of the reinforcing fiber contained in the resin member is performed in advance before the contact with the metal member on the surface of the resin member in contact with the metal member as part of the joining process, the spring The generation of the back layer can be sufficiently prevented. In the case where the shortening is performed in advance before the contact with the metal member, as a method for shortening the fiber, at least the surface layer portion 121 in the region immediately below the rotary tool in the resin member 12 is irradiated with a laser or in a lattice shape. There is a method of piercing the cutter. In the surface layer portion 121 of the rotary tool the region immediately below the resin member 12 that fiber shortening is achieved, the reinforcing fibers have the average fiber length L _A.

[Resin member]
A resin member 12 having dimensions of 100 mm in length, 30 mm in width, and 3 mm in thickness was produced by an injection molding method using polypropylene pellets containing 40% by weight of carbon fibers (PP-CF40-11; manufactured by Daicel Polymer Co., Ltd.). In the resin member, the average fiber length of the carbon fibers was 3 mm, and the average fiber diameter was 7 μm. The melting point Tm of the resin member was 170 ° C. In the resin member, the carbon fibers were randomly oriented.

[Metal members]
As the metal member X, a 6000 series aluminum alloy flat plate member (thickness 1.2 mm) having a uniaxial protrusion 501 as shown in FIG. The formation area of the protrusion 501 was an area directly below the rotary tool on the resin member side surface of the metal member. The pitch x of the protrusions 501 was 1 mm, the height y was 0.5 mm, and the apex angle was 20 °. The protruding portion 501 was formed by pressing the metal member 11 with a mold corresponding to a predetermined shape.

  As the metal member Y, a flat member (thickness 1.2 mm) made of a 6000 series aluminum alloy having a biaxial protrusion 502 as shown in FIG. . The formation region of the protrusion 502 was a region directly below the rotary tool on the resin member side surface of the metal member. The pitches x1 and x2 of the protrusions 502 were 1 mm, the heights y1 and y2 were 0.5 mm, and the apex angle was 20 °. The protrusion 502 was formed by the same method as the protrusion 501.

  As the metal member Z, a flat plate member (thickness: 1.2 mm, no protrusion) made of a 6000 series aluminum alloy was used as it was.

[Rotation tool]
As the rotating tool, a tool made of tool steel having dimensions of each part in FIG. 2 of D1 = 10 mm, D2 = 2 mm, and h = 0.5 mm was used.

[Example 1] (First embodiment)
A metal member Z was used as the metal member 11.
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.

Second step:
First, while rotating the rotary tool, it was pushed into the metal member by the position control method to enter the metal member. Specifically, as shown in FIG. 4, the rotary tool 16 was pushed into the metal member 11 to enter the interface 13 between the metal member 11 and the resin member 12 (indentation stirring step). The rotation number, insertion amount and insertion speed of the rotating tool were as shown in the table.

  Next, as shown in FIG. 4, the rotational operation of the rotary tool 16 was continued at the position where the rotary tool 16 was advanced to the depth reaching the interface 13 by the position control method (stirring maintaining step). The number of rotations and duration (stirring time) were as shown in the table.

  Next, the rotary tool 16 was separated from the metal member 11 and allowed to cool.

(Joint strength)
As shown in FIG. 9, 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.
◎◎; 5.0 ≦ S;
A; 4.0 ≦ S <5.0;
○: 3.0 ≦ S <4.0 (no problem in practical use);
X: S <3.0 (practical problem).

(Melting zone)
The diameter R of the melt-solidified region was measured by the method described above, and R / D1 was calculated.

(Springback layer)
The thickness of the springback layer was measured by the following method.
In a state where the metal member and the resin member are joined, the cross section is observed in the plate thickness direction of the part to be measured. Since the springback layer is in a state where air is taken in and foamed, the difference from other parts can be easily confirmed by visual observation. At this time, the resin layer solidified after melting without springback is the same as the non-molten resin layer except that it has a step.
Specifically, the maximum thickness of the springback layer was determined in the region immediately below the rotary tool in the cross-sectional image of the joined body.

(Reinforced fiber)
The metal member 11 was forcibly removed from the resin member 12. As shown in FIG. 8, in a donut-shaped region 121 </ b> C excluding the region 60 directly below the rotating tool 60 from a circular region 62 (broken line) having a diameter of 15 mm concentric with the region 60 directly below the rotating tool 60 on the metal member side surface 120 of the resin member 12. Then, samples up to a depth of 0.1 mm were scraped off at arbitrary 10 locations and weighed (w1; mg). Next, the sample was heated by an electric furnace or the like at a temperature not lower than the decomposition temperature of the thermoplastic polymer (resin component) and not higher than the decomposition temperature of the reinforcing fiber, thereby removing the thermoplastic polymer and filtering out only the reinforcing fiber. Finally, the filtered reinforcing fibers were weighed (w2; mg) and the content was calculated according to the following formula:
Reinforcing fiber content (% by weight) = (w2 / w1) × 100
The average fiber length of the reinforcing fibers was determined by directly measuring the length of any 100 reinforcing fibers from a photograph of the reinforcing fibers obtained at the time of content measurement.

[Example 2 and Comparative Examples 1-2]
Except that the joining conditions were changed as shown in the table, the joining of the resin member and the metal member was matched and evaluated by the same method as in Example 1.
Example 2 corresponds to the first embodiment.

[Example 3 (Reference Example) ] (Second Embodiment)
A metal member X was used as the metal member 11.
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.

Second step:
First, while rotating the rotary tool, it was pushed into the metal member by the position control method to enter the metal member. Specifically, as shown in FIG. 5, the fiber cutting projection 50 of the metal member 11 was stuck to the resin member 12 by the initial pressing with the rotary tool 16. Thereafter, as shown in FIG. 6, the rotary tool 16 was pushed into the metal member 11 to enter the interface 13 between the metal member 11 and the resin member 12 (indentation stirring step). The number of rotations, the amount of insertion, and the approach speed of the rotating tool were as shown in the table.

  Next, as shown in FIG. 6, the rotational operation of the rotary tool 16 was continued at the position where the rotary tool 16 was advanced to the depth reaching the interface 13 by the position control method (stirring maintaining step). The number of rotations and duration (stirring time) were as shown in the table.

  Next, the rotary tool 16 was separated from the metal member 11 and allowed to cool.

  Evaluation of the joined body of the resin member and the metal member was performed in the same manner as in Example 1.

[Example 4 (Reference Example) ] (Second Embodiment)
Except that the joining conditions were changed as described in the table, matching and evaluation of the joined body of the resin member and the metal member were performed in the same manner as in Example 2.

  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: Immediately below the rotating tool of the metal member P: Pressing area (Pressing scheduled area)
111: Pressing area (after pressing)
121: Surface layer portion of region directly under rotating tool in resin member

Claims (10)

The metal member and the resin member containing the reinforcing fiber are overlapped, pressure is applied to the resin member by pressing from the metal member side by the pressing member, and the resin member is softened and melted by heat, and then solidified and bonded. A method of joining a metal member and a resin member by a hot-pressure joining method,
During the joining, the reinforcing member is shortened by pressing into the metal member while rotating the pressing member, entering the interface between the metal member and the resin member, and heating and stirring the surface of the resin member. A joining method of a metal member and a resin member characterized by the above.   The method for joining a metal member and a resin member according to claim 1, wherein the shortening is performed by a shearing force caused by the pressing member.   The joining method of the metal member and resin member of Claim 1 or 2 which performs the said short fiber by the shear force resulting from the rotational force and / or pressing force of the said pressing member. Wherein the metal member has a fiber cutting projections on the resin member surface, also it's a fiber cutting projections of the metal member in the initial pressing of the pressing member to stab the resin member, the short fibers The joining method of the metal member and resin member in any one of Claims 1-3 which performs formation. The joining method of the metal member and resin member in any one of Claims 1-4 which performs the said short fiber in the surface layer part of the area | region directly under a press member in the metal member side surface of the said resin member. The hot-pressure bonding method is
A first step of superimposing the metal member and the resin member; and, while rotating the rotary tool as the pressing member, pressing the metal member to generate frictional heat, and softening and melting the resin member by this frictional heat, The method for joining a metal member and a resin member according to any one of claims 1 to 5 , which is a friction stir welding method including a second step of solidifying and joining the metal member and the resin member. The second step includes
A pushing and stirring step of pushing the rotating tool into the metal member and entering at least the inside of the metal member; and an agitation maintaining step of continuing the rotating operation of the rotating tool at the position where the rotating tool is entered in the pushing and stirring step. ,
The joining method of the metal member and resin member of Claim 6 which performs the said short fiber in one or both of the said pushing stirring process or the said stirring maintenance process. The average fiber length L _A of the short fiberized reinforcing fibers is 1mm or less, method of joining the metal member and the resin member according to any one of claims 1-7. The average fiber length L _B of the reinforcing fiber before fiber shortening is 1mm super 50mm or less, method of joining the metal member and the resin member according to any one of claims 1-8. The resin member contains the reinforcing fiber in a proportion of 10 to 50% by weight relative to the resin member the total amount, method of joining the metal member and the resin member according to any one of claims 1-9.

Images