JP2017159517A - Method and apparatus for joining metal member and resin member to each other - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for joining a metal member and a resin member to each other, in which joint strength can be sufficiently improved.SOLUTION: In the method for joining a metal member and a resin member to each other by a heat-pressing type joining method in which a metal member and a resin member are allowed to overlap one another, pressure and heat are applied to the resin member by press from a metal member side by a press member, to soften and melt the resin member, and the resin member is then solidified to perform joining, the joining is performed while the pulse variation of the amount of the applied heat is caused.SELECTED DRAWING: None

Description

  The present invention relates to a joining method and joining apparatus for 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. 15, the friction stir welding method is a method in which a metal member 211 and a resin member 212 are overlapped and pressed against the metal member 211 while rotating the rotary tool 216 to continuously generate frictional heat. In this method, the resin member 212 is melted by the frictional heat and then solidified to join the metal member 211 and the resin member 212 (Patent Document 1).

  Moreover, in the friction stir welding method, a technique for bonding with high strength by using a resin member having a functional group as the resin member is disclosed (Patent Document 2).

JP 2010-158885 A JP 2014-208461 A

  Inventors of the present invention, in the conventional friction stir welding method, from the viewpoint of improving the bonding strength, not only the portion immediately below the rotary tool on the surface of the resin member at the interface between the metal member and the resin member but also the outer peripheral portion thereof is melted. On the contrary, it was found that sufficient bonding strength could not be obtained.

Specifically, in the conventional friction stir welding method, frictional heat is continuously generated to melt the lower portion 260 immediately below the rotary tool of the resin member 212 as shown in FIG. 16, as shown in FIG. The difference d ′ between the temperature of the immediate lower portion 260 and the temperature of the outer peripheral portion 261 became relatively large. For this reason, the outer peripheral part 261 did not fully melt | dissolve and sufficient joint strength was not obtained. FIG. 16 is a schematic cross-sectional view for explaining a conventional friction stir welding method. FIG. 17 shows an example of changes over time in the temperature of the immediate lower portion 260 (interface temperature at K ₂₆₀ in FIG. 16) and the temperature of the outer peripheral portion 261 (interface temperature at K ₂₆₁ in FIG. 16) in the conventional friction stir welding method. It is a graph which shows.

Therefore, when frictional heat is continuously generated in order to melt not only the immediate lower portion 260 but also the outer peripheral portion 261 thereof, as shown in FIG. 18, the temperature of the direct lower portion 260 and the temperature of the outer peripheral portion 261 are Since the difference d ″ is still relatively large, the lower part 260 is overheated, and sufficient bonding strength cannot be obtained. The overheating immediately below occurred remarkably when the metal member was made of a steel plate having a relatively low thermal conductivity than when the metal member was made of aluminum having a relatively high thermal conductivity. For example, when the resin member 212 is made of a polypropylene resin containing 40% by weight of carbon fiber, as shown in FIG. 14, when the resin is overheated to over 330 ° C., the bonding strength (shear strength) is lowered. Such a decrease in bonding strength due to overheating is considered to be based on the fact that resin molecules are decomposed by overheating. FIG. 18 shows an example of the change over time of the temperature of the immediate lower portion 260 (interface temperature at K ₂₆₀ in FIG. 16) and the temperature of the outer peripheral portion 261 (interface temperature at K ₂₆₁ in FIG. 16) in the conventional friction stir welding method. It is a graph which shows. FIG. 14 shows the relationship between the temperature and the bonding strength when the adhesive strength (shear strength) is measured by varying the temperature immediately below the rotary tool of the resin member used in the examples.

  An object of this invention is to provide the joining method of the metal member and resin member which can fully improve joining strength.

The present invention
The metal member and the resin member are overlapped, pressure is applied to the resin member by pressing from the metal member side by the pressing member, heat is applied to soften and melt the resin member, and then solidified to perform bonding. It is a joining method of a metal member and a resin member by a hot-pressure joining method,
The present invention relates to a joining method between a metal member and a resin member, in which the joining is performed while changing the amount of heat applied.

  According to the bonding method of the present invention, the bonding strength can be sufficiently improved.

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 preheating process in the said joining method while showing the schematic sectional drawing of an example of the metal member and resin member which are used for the joining method of this invention. It is an example of the graph which shows the time-dependent temperature change of the rotation tool direct lower part of the resin member in the joining method of this invention, and its outer peripheral part. It is a graph which shows an example of a time-dependent change of the calorie | heat amount when changing the pulse of the calorie | heat amount provided in this invention. It is a schematic sectional drawing for demonstrating an example of the pushing stirring process and stirring stirring process in the said joining method while showing the schematic sectional drawing of a metal member and an example of a resin member used for the joining method of this invention. In the joining method which concerns on the load control system of this invention, it is a graph which shows an example (method (i-1)) of the control method of the drive of a rotary tool when performing an indentation stirring process, changing the heat amount to provide with a pulse. . In the joining method which concerns on the load control system of this invention, it is a graph which shows an example (method (i-2)) of the control method of the drive of a rotary tool when performing an indentation stirring process, changing the amount of heat to provide with a pulse. . In the joining method which concerns on the load control system of this invention, it is a graph which shows an example (method (i-3)) of the control method of the drive of a rotary tool when performing an indentation stirring process, changing the amount of heat to apply | coat with a pulse. . In the joining method which concerns on the position control system of this invention, it is a graph which shows an example (method (ii-1)) of the control method of the drive of a rotary tool when performing an indentation stirring process, changing the amount of heat to give with a pulse. . In the joining method which concerns on the position control system of this invention, it is a graph which shows an example (method (ii-2)) of the control method of the drive of a rotary tool when performing an indentation stirring process, changing the amount of heat to provide while changing a pulse. . In the joining method which concerns on the position control system of this invention, it is a graph which shows an example (method (ii-3)) of the control method of the drive of a rotary tool when performing an indentation stirring process, changing the amount of heat to provide with a pulse. . It is the schematic for demonstrating the measuring method of the joint strength in an Example. The relationship between the said temperature and joining strength when the adhesive strength (shear strength) is measured by changing the temperature of the direct lower part of a rotary tool variously using the resin member used in the Example of this invention is shown. It is this schematic sketch for demonstrating the joining method of the metal member and resin member in a prior art. It is a schematic sectional drawing of an example of a metal member and a resin member for demonstrating the mechanism in which joining strength falls in a prior art. It is an example of the graph which shows the time-dependent temperature change of the rotation tool right part of the resin member in the prior art, and its outer peripheral part. It is an example of the graph which shows the time-dependent temperature change of the rotation tool right part of the resin member in the prior art, and its outer peripheral part.

  In the joining method of the present invention, after 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 heat is applied to soften and melt the resin member. This is a hot-pressure joining method in which a metal member and a resin member are joined by solidification. 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. As will be described later, the hot-pressure bonding method is not particularly limited as long as it is a method capable of performing bonding while changing the amount of heat to be applied, for example, a 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.

  The friction stir welding method, as will be described in detail later, generates frictional heat by pressing the resin member from the metal member side while overlapping the metal member and the resin member and rotating the rotary tool as the pressing member. The resin member is softened and melted with this frictional heat and then solidified to join the metal member and the resin member.

  The ultrasonic heat bonding method is a method in which a metal member and a resin member are overlapped, and the pressure member and the metal member are pressed by the ultrasonic wave (heat applying means) while the resin member is pressed from the metal member side by the pressing member. In this method, the resin member is softened and melted by the frictional heat of the resin member / metal member generated by the vibration, 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 a metal member with a laser (heat applying means) in a state where the metal member and the resin member are constrained by pressurization by a pressing member. In this method, the resin member is softened and melted by heat and then solidified to join the metal member and the resin member. As the laser, a YAG laser, a fiber laser, a semiconductor laser, or the like is used.

  The resistance heating bonding method uses heat generated by flowing a current (heat applying means) directly to a metal member in a state where the metal member and the resin member are overlapped and constrained by pressurization by the pressing member. The resin member is softened and melted and then solidified to join the metal member and the resin member.

  The induction heating joining method is a method in which a metal member and a resin member are overlapped, and an induction current (heat applying means) is generated in the metal member by electromagnetic induction in a state in which the metal member and the resin member are constrained by pressurization by the pressing member. In this method, the resin member is softened and melted using heat generated by an electric current and then solidified to join the metal member and the resin member.

  Hereinafter, the joining method of the present invention adopting the friction stir welding method will be described in detail with reference to the drawings. However, as long as joining is performed while changing the amount of heat to be applied, the present invention can be used even if other joining methods described above are used. It is clear that the effect of can be obtained. 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 tip portion of an example 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 that supports the pin portion at a distal end portion (lower end portion in FIG. 2) that contacts the metal member. 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), 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.

  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 capable of changing the amount of heat applied by driving the rotary tool 16 as a pressing member in a pulse manner, in particular, the pressing tool driving condition, particularly the pressing driving condition and / or the rotational driving condition, preferably A drive control device (not shown) for controlling the pressing drive condition and the rotational drive condition is included.

  As will be described in detail later, the drive control device may adopt a load control method for controlling the load applied to the rotating tool, the pressurizing time, and the number of rotations, or the approach speed, the amount of approach, and the identification of the rotating tool. You may employ | adopt the position control system which controls the holding time and rotation speed in a position.

  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 In the present invention, joining is performed while controlling the amount of heat applied to the metal member 11 and the resin member 12. Specifically, bonding is performed while changing the amount of heat to be applied in pulses. Joining while changing the amount of heat to be applied means that the joining is performed by repeatedly switching the amount of heat to be applied. Specifically, joining is performed by applying pressure and heat. In this case, it means that a relatively large amount of heat and a relatively small amount of heat are repeatedly applied. By controlling the amount of heat, the temperature difference d between the lower part 60 of the rotation tool of the resin member 12 and the outer peripheral portion 61 at the boundary surface 13 between the metal member 11 and the resin member 12 as shown in FIG. Can be reduced as shown in FIG. As a result, overheating of the direct lower portion 60 is suppressed, and heat conduction in the metal member 11 is sufficiently achieved while controlling the temperature of the direct lower portion 60 to be equal to or lower than the decomposition temperature (Td (° C.)) of the resin member 12. The outer peripheral portion 61 can also be melted. For this reason, the decomposition of the resin molecules in the direct lower portion 60 is suppressed, and the direct lower portion 60 and its outer peripheral portion 61 are sufficiently melted, both of which are bonded to the metal member 11 and the bonding strength is sufficiently improved. be able to. FIG. 3 shows a schematic cross-sectional view of an example of a metal member and a resin member used in the joining method of the present invention. FIG. 4 shows the temperature T ₆₀ (the interface temperature at P ₆₀ in FIG. 3) and the temperature T ₆₁ of the outer periphery ₆₁ (the interface temperature at P ₆₁ in FIG. 3) in the friction stir welding method of the present invention. It is a graph which shows an example of a time-dependent change.

4, the temperature _{T 61} temperature _{T 60} and the outer peripheral portion 61 immediately below portion 60, under the control of heat, has been controlled to the joint contribution range (about 200 to 300 [° C.), such bonding contributes range Is determined based on the melting point Tm (° C.) and the decomposition temperature Td (° C.) of the resin member 12 used. The joining contribution range means a temperature range in which melting that contributes to joining is possible without decomposition of resin molecules. The joining contribution range is usually the melting point Tm or more and the decomposition temperature Td or less of the resin member 12, and preferably Tm + 30 (° C.) to Tm + 130 (° C.). Note that the temperature T ₆₁ of the outer peripheral portion 61 does not exceed the temperature T ₆₀ of the direct lower portion 60 due to the positional relationship between the direct lower portion 60 and its outer peripheral portion 61 and the rotary tool 16 that imparts heat.

In the present invention, the temperature T ₆₀ immediately below portion 60 is also the temperature T ₆₁ of the outer peripheral portion 61, early reaches the junction contribution range, and after reaching the transitions within the joint contribution range to the final cooling step It is preferable. From the viewpoint of further improving the bonding strength, the time the temperature T ₆₀ and the temperature T ₆₁ of the outer peripheral portion 61 immediately below portion 60 has remained at the joint contribution range longer preferred.

  In the present invention, the waveform of the pulse change of the amount of heat (repetitive form of a relatively large amount of heat and a relatively small amount of heat) is not particularly limited as long as the temperature of the portion 60 directly below the rotary tool in the resin member can be controlled to Td or less. For example, it may be periodic as shown in FIG. 5 or aperiodic. Preferably, the amount of heat to be applied is periodically pulse-changed from the viewpoint of ease of heat amount control. FIG. 5 is a graph showing an example of a temporal change in the amount of heat when the amount of heat applied in the present invention is changed in pulses. In FIG. 5, “70” indicates a time when a relatively large amount of heat is applied, and “71” indicates a time when a relatively small amount of heat is applied.

  In FIG. 5, the pulse waveform of the amount of heat is shown as a rectangular wave, but the waveform is not particularly limited as long as a relatively large amount of heat and a relatively small amount of heat are repeatedly applied. For example, a sine wave, It may be a triangular wave or a sawtooth wave.

  The relatively large amount of heat Ha and its unit application time Ta, the relatively small amount of heat Hb and its unit application time Tb, and the ratio and period Tc thereof are the temperatures of the rotary tool directly lower portion 60 and the outer peripheral portion 61 of the resin member 12. There is no particular limitation as long as the temperature of the immediately lower part can be controlled to Td or less by reducing the difference d.

The amount of heat Hb is usually 0.7 × Ha or less, preferably 0.5 × Ha or less, more preferably 0.3 × Ha or less, and even more preferably 0.
The ratio Hb / Ha is usually 0.7 or less, preferably 0.5 or less, more preferably 0.3 or less, and even more preferably 0.
The ratio Tb / Ta is usually 0.5 to 2, preferably 0.8 to 1.2, and more preferably 1.
Ta and Tb are each independently usually 0.1 to 1 second, preferably 0.1 to 0.5 second, and more preferably 0.1 to 0.3 second.
Tc is usually 0.2 to 2 seconds, preferably 0.2 to 1 second, and more preferably 0.2 to 0.6 seconds.

  When the ratio Hb / Ha and / or Hb is decreased or the ratio Tb / Ta and / or Tb is increased in the repetition of the relatively large heat amount Ha and the relatively small heat amount Hb, The temperature difference d with the outer peripheral portion decreases, and the temperature immediately below the rotating tool tends to decrease. On the other hand, if the ratio Hb / Ha and / or Hb is increased or the ratio Tb / Ta and / or Tb is decreased in the repetition, the temperature difference d between the lower portion of the resin member and the outer peripheral portion thereof increases. The temperature immediately below the rotating tool tends to increase.

  In the joining method of the metal member and the resin member by the friction stir welding method according to the present invention, the above-described control of the amount of heat is performed by driving the rotary tool 16, in particular, pressing drive and / or rotating drive, preferably pressing drive and rotating drive. , Can be performed by controlling. Since specific control factors and their control methods differ between the load control method and the position control method, they will be described in detail later.

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, 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 joining method of the metal member and the resin member by the friction stir welding method according to the present invention, the second step may be performed while changing the amount of heat in pulses as described above.

  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 drive condition of the rotary tool is controlled to change the amount of heat in pulses as described above. In the second step, a load control method for controlling the load applied to the rotary tool, the pressurizing time and the rotational speed, or a position control system for controlling the approach speed, the approach amount, the holding time at a specific position and the rotational speed of the rotary tool. Is adopted. Hereinafter, the second step employing the load control method will be described as the first embodiment, and the second step employing the position control method will be described as the second embodiment.

<First Embodiment: Load Control Method>
In this embodiment, as the driving condition of the rotating tool, one or more driving conditions selected from the group consisting of the load applied to the rotating tool, the pressurizing time, and the number of rotations are controlled, and the amount of heat is pulsed as described above. The second step may be performed while changing.

  In the second step of the present embodiment, at least the pushing and stirring step C <b> 2 for pushing the rotary tool 16 into the metal member 11 and entering to a depth that does not reach the joining boundary surface 13 between the metal member 11 and the resin member 12 is performed. preferable.

  In the second step of the present embodiment, a preheating step C1 for rotating the rotary tool 16 in a state where only the front end portion of the rotary tool 16 is in contact with the surface portion of the metal member 11 is performed before the pushing and stirring step. Although preferred, it is not necessary.

  In the second step of the present embodiment, it is preferable to perform the stirring maintaining step C3 for continuing the rotating operation of the rotating tool 16 at the position where the rotating tool 16 is entered in the pressing stirring step after the pressing stirring step. However, this process is not necessarily performed.

  In the second step of the present embodiment, at least the indentation stirring process among the preheating process, the indentation stirring process, and the agitation maintaining process may be performed by changing the amount of heat as described above.

  Hereinafter, these steps in this embodiment will be described in detail.

(Preheating process C1)
In the preheating step C1, 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. In the preheating step C1, the rotary tool 16 is moved to a first rotation speed r1 (for example, for (1-2 seconds) with a first load p1 (for example, 900 to 1200 N) for a first pressurizing time t1 (for example (for 1-2 seconds)). 3 is a schematic cross-sectional view of the XX cross section in FIG.

  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 area P (the pressing area by the rotary tool 16) of the metal member 11 and the area near the pressing area 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.

  The amount of heat applied in this step is mainly determined by the magnitude of the first load p1, the length of the first pressurizing time t1, and the magnitude of the first rotation speed r1 of the rotary tool.

  The first load p1 and the first pressurization time t1 in the preheating step C1 are the control of the heat amount, the ease of pushing the rotary tool in the next step, the ease of softening and melting the resin member, and the productivity. The value may be determined depending on, for example, the number of rotations of the rotary tool 16, the thickness of the metal member 11, the type of material, the melting point of the resin member 12, and the like. For example, when using an aluminum alloy metal member 11 having a thickness of 1 mm or more and 2 mm or less and a resin member 12 having a melting point described later, the first load p1 in the preheating step C1 is preferably less than 1300N. The first pressurization time t1 is preferably 0.5 seconds or longer. The rotational speed r1 of the rotary tool is preferably 4000 rpm or less.

(Indentation stirring step C2)
In the pushing and stirring step C2, the rotating tool 16 and the receiving member 17 are brought close to each other, thereby pushing the rotating tool 16 into the metal member 11 as shown in FIG. When the pushing and stirring step C2 is performed after the preheating step C1, the rotating tool 16 and the receiving member 17 are brought closer 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. Thereby, about the molten resin 120 of the resin member surface melt | dissolved in the area | region immediately under a rotating tool, the fusion | melting and the flow (arrow direction of FIG. 6) to the outer peripheral area | region can be promoted. 6 is a schematic cross-sectional view of the XX cross-section in FIG. 1 as viewed in the direction of the arrow.

  Specifically, in the indentation stirring step C2, the rotary tool 16 is subjected to the second pressurization time t2 (for example, 2 to 4 seconds) with the second load p2 (for example, 1500 N to 3000 N) larger than the first load p1. Only at the second rotation speed r2 (for example, 2500 to 3500 rpm).

  In the indentation stirring step C2, the rotary tool 16 is pushed into the metal member 11 because the load 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. By the indentation stirring step C2 and the stirring maintaining step C3 that is preferably performed thereafter, the melting of the molten resin 120 on the surface of the resin member melted in the region immediately below the rotary tool at the joining interface 13 is promoted, and the region immediately below And flows to the outer peripheral region (in the direction of the arrow in FIG. 6). The molten resin spreads in a substantially circular shape centering on the region directly under 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 (bonded region) obtained by solidifying the molten resin by cooling in the obtained bonded body is also expanded. Can be achieved with sufficiently good working efficiency and sufficient strength.

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

  Therefore, in this 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 joint boundary surface. In other words, the rotary tool 16 is advanced to a depth that does not reach the joint interface. Thereby, solidification of the resin member 12 is accelerated | stimulated by the following stirring maintenance process C3.

  The amount of heat applied in this step is mainly determined by the magnitude of the second load p2, the length of the second pressurizing time t2, and the magnitude of the second rotation speed r2 of the rotary tool.

In the indentation stirring step C2, in order to change the amount of heat in pulses as described above, the second load larger than the first load (p1) while rotating the rotary tool at the second rotation speed (r2) or less. The driving for pressing below the load (p2) is performed for the second pressurization time (t2), and one method selected from the following methods is followed:
(I-1) As shown in FIG. 7, the driving unit i-1a for rotating the rotating tool at r2 and pressing it at p2, and the driving unit for rotating the rotating tool at r2 and pressing it at 0.7 × p2 or less. i-1b is repeated by t2; in the driving unit i-1b, the load is preferably 0.5 × p2 or less, more preferably 0.3 × p2 or less, and further preferably 0N;
(I-2) As shown in FIG. 8, the drive unit i-2a for rotating the rotary tool at r2 and pressing it at p2, and the drive unit for pressing at p2 while rotating the rotary tool at 0.5 × r2 or less i-2b is repeated by t2; in the drive unit i-2b, the rotation speed is preferably 0.3 × r2 or less, more preferably 0.1 × r2 or less, and further preferably 0 rpm;
(I-3) As shown in FIG. 9, the drive unit i-3a that rotates the rotating tool at r2 and presses it at p2, and 0.7 × p2 or less while rotating the rotating tool at 0.7 × r2 or less. The driving unit i-3b to be pressed is repeated by t2; in the driving unit i-3b, the load is preferably 0.6 × p2 or less, more preferably 0.5 × p2 or less, and further preferably 0N. In the drive unit i-3b, the rotation speed is preferably 0.6 × r2 or less, more preferably 0.5 × r2 or less, and further preferably 0 rpm; and (i-4) (i− A combination of two or more drive units selected from the drive units 1) to (i-3) and having different loads and / or rotational speeds is repeated for t2.

  The method (i-1), (i-2) or (i-3), particularly the methods (i-1) and (i-3) are preferred.

  The second load p2 and the second pressurization time t2 in the indentation stirring step C2 are the viewpoints of the control of the heat amount, the avoidance of the opening of the metal member 11 as described above, and the proximity of the rotary tool 16 to the resin member 12. 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, the melting point of the resin member 12, 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 and a resin member 12 having a melting point described later are used, the second load p2 in the indentation stirring step C2 is preferably 3000 N or less. The second pressurization time t2 is preferably 4 seconds or less. The second rotational speed r2 of the rotary tool is preferably 3500 rpm or less.

  The amount of heat applied in this step can also vary depending on the ratio of the drive unit time of each drive unit in the methods (i-1) to (i-3). For example, the ratio tb / ta between the drive unit time ta of the drive unit i-1a and the drive unit time tb of the drive unit i-1b, the drive unit time ta of the drive unit i-2a, and the drive unit i-2b The ratio tb / ta with respect to the drive unit time tb and the ratio tb / ta between the drive unit time ta of the drive unit i-3a and the drive unit time tb of the drive unit i-3b are usually 0.5-2. It is preferably 0.8 to 1.2, more preferably 1. In this step, ta and tb are each independently usually 0.1 to 1 second, preferably 0.1 to 0.5 second, more preferably 0.1 to 0.3 second.

(Stirring maintenance step C3)
In the stirring maintaining step C3, by stopping the mutual proximity of the rotary tool 16 and the receiving member 17, as shown in FIG. This is a step of continuing the rotation operation of the rotary tool 16 at the “position”). In the stirring maintaining step C3, the rotary tool 16 is moved for the third pressurization time t3 (for example, 2 to 4 seconds) with the third load p3 (for example, 500 to 800 N) smaller than the first load p1. It is rotated at a rotation speed of 3 (for example, 1500 to 2500 rpm).

  In the stirring maintaining step C3, the load p3 is smaller than that in the pushing stirring step C2, so that the rotary tool 16 is substantially maintained at the reference position. Although the rotation operation of the rotary tool 16 is continued at the reference position close to the resin member 12, since the load applied to the tool is small, the generated frictional heat is small and the molten resin is sufficiently solidified.

  The amount of heat applied in this step is mainly determined by the magnitude of the third load p3, the length of the third pressurizing time t3, and the magnitude of the third rotational speed r3 of the rotary tool.

  The third load p3 and the third pressurization time t3 in the main stirring and maintaining step C3 are set from the viewpoints of control of the heat amount, sufficient softening / melting of the resin member 12 as described above, 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, the melting point of the resin member 12, 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 and a resin member 12 having a melting point described later are used, the third load p3 in the stirring and maintaining step C3 is preferably less than 800N. The third pressurization time t3 is preferably 2.0 seconds or longer. The third rotation speed r3 of the rotary tool is preferably 2500 rpm or less.

  In the present embodiment, after the final step, solidification may be promoted by cooling. The cooling method is not particularly limited, and the cooling may be performed by standing or may be forcibly cooled from the outside.

<Second Embodiment: Position Control Method>
In this embodiment, as the driving condition of the rotary tool, one or more driving conditions selected from the group consisting of the approach speed, the approach amount, the holding time, and the rotational speed of the rotary tool are controlled, and the amount of heat is as described above. The second step may be performed while changing the pulse.

  Also in the second step of the present embodiment, at least the pushing and stirring step C <b> 2 for pushing the rotary tool 16 into the metal member 11 and entering it to a depth that does not reach the joint boundary surface 13 between the metal member 11 and the resin member 12 is performed. preferable.

  In the second step of the present embodiment, a preheating step C1 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 is performed before the indentation stirring step. However, since the position control method is adopted, it is not normally performed.

  After the indentation stirring step, it is preferable to perform an agitation maintenance step C3 in which the rotation operation of the rotation tool 16 is continued at a position where the rotation tool 16 has entered in the indentation stirring step, but the step must be necessarily performed. Not that.

  In the second step of this embodiment, when performing at least one process selected from the indentation stirring process and the stirring maintenance process, the amount of heat may be changed in pulses as described above. From the viewpoint of sufficiently lowering the temperature of the resin member directly below the rotary tool 60, it is preferable to change the amount of heat in pulses as described above when performing the indentation stirring step.

  Hereinafter, these steps in this embodiment will be described in detail.

(Indentation stirring step C2)
The indentation stirring process C2 of this embodiment is the same as the indentation stirring process C2 of the first embodiment, except that the position control method is adopted by the following method. Specifically, in the indentation stirring step C2 of the present embodiment, as shown in FIG. 6, the first approach speed v1 (the rotation tool 16 is rotated at a fourth rotation speed r4 (for example, 2500 to 3500 rpm). For example, the first approach amount (entrance depth) d1 (for example, 0.5 × T to 0.9 × T when the thickness of the metal member is T (mm)) is reached at 5 to 50 mm / min. To enter.

  In the indentation stirring step C <b> 2, the rotating tool 16 is made to enter the first approaching amount at the first approach speed, so that the joining boundary surface between the metal member 11 and the resin member 12 at the lower part 110 of the rotating tool of the metal member 11. 13 moves to the receiving member 17 side (lower side in the illustrated example), and the immediate lower part 110 projects and deforms toward the resin member 12 side. As a result, as in the indentation stirring step C2 of the first embodiment, the melting of the molten resin 120 on the surface of the resin member melted in the region immediately below the rotary tool at the joining interface 13 is promoted, and the region immediately below And flows to the outer peripheral region (in the direction of the arrow in FIG. 6). The molten resin spreads in a substantially circular shape centering on the region directly under 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 (bonded region) obtained by solidifying the molten resin by cooling in the obtained bonded body is also expanded. Can be achieved with sufficiently good working efficiency and sufficient strength.

  The amount of heat applied in this step is mainly determined by the magnitude of the first approach speed v1 of the rotary tool, the magnitude of the first approach quantity d1, and the magnitude of the fourth rotational speed r4.

In the indentation stirring step C2, in order to change the amount of heat in a pulse manner as described above, the first approach amount (v1) or less at the first approach speed (v1) while rotating at the fourth revolution number (r4) or less. Enter until d1) is reached and follow one method selected from:
(Ii-1) As shown in FIG. 10, the drive unit ii-1a for rotating the rotating tool at r4 and entering at v1 and the driving unit for entering at 0.5 × v1 or less while rotating the rotating tool at r4 ii-1b is repeated until the approach amount reaches d1; in the drive unit ii-1b, the approach speed is preferably 0.3 × v1 or less, more preferably 0.1 × v1 or less, and even more preferably 0 mm / Min;
(Ii-2) As shown in FIG. 11, a drive unit ii-2a for rotating the rotating tool at r4 and entering at v1, and a driving unit for moving the rotating tool at 0.8 × r4 or less and entering at v1 ii-2b is repeated until the approach amount reaches d1; in the drive unit ii-2b, the rotational speed is preferably 0.6 × r4 or less, more preferably 0.5 × r4 or less, and even more preferably 0 Less than or equal to 4 × r4;
(Ii-3) As shown in FIG. 12, the drive unit ii-3a that rotates the rotating tool at r4 and enters at v1, and the rotating tool that rotates at 0.8 × r4 or less and 0.5 × v1 or less. The driving unit ii-3b that is entered in step S3 is repeated until the approaching amount reaches d1; in the driving unit ii-3b, the approach speed is preferably 0.3 × v1 or less, more preferably 0.1 × v1 or less. In the driving unit ii-3b, the rotation speed is preferably 0.6 × r4 or less, more preferably 0.5 × r4 or less, and further preferably 0.4 × r4 or less. And (ii-4) The amount of approach is d1 by combining two or more types of drive units selected from the drive units (ii-1) to (ii-3) having different approach speeds and / or rotational speeds. Until it reaches Repeat.

  From the viewpoint of further improving the bonding strength and shortening the bonding time, the method (ii-1), (ii-2) or (ii-3), particularly the method (ii-1) is preferable.

  The first approach speed v1 and the first approach amount d1 of the rotary tool in the indentation stirring step C2 are set from the viewpoint of controlling the heat amount, and the values thereof are, for example, the number of rotations of the rotary tool 16 and the metal member 11 It varies depending on the thickness, the type of material, the melting point of the resin member 12, and the like. For example, when using an aluminum alloy metal member 11 having a thickness of 1 mm or more and 2 mm or less and a resin member 12 having a melting point described later, the first entry speed v1 in the indentation stirring step C2 is preferably 10 to 30 mm / min. The first approach amount d1 is preferably 0.4 × T to 0.95 × T, where T (mm) is the thickness of the metal member. The amount of entry is the depth of entry in the thickness direction from the surface of the metal member. The fourth rotation speed r4 of the rotary tool is preferably 2500 rpm or more.

  The amount of heat applied in this step can also change depending on the ratio of the drive unit time of each drive unit in the methods (ii-1) to (ii-3). For example, the ratio tb / ta between the drive unit time ta of the drive unit ii-1a and the drive unit time tb of the drive unit ii-1b, the drive unit time ta of the drive unit ii-2a, and the drive unit ii-2b The ratio tb / ta with respect to the drive unit time tb and the ratio tb / ta between the drive unit time ta of the drive unit ii-3a and the drive unit time tb of the drive unit ii-3b are usually 0.5-2. It is preferably 0.8 to 1.2, more preferably 1. In this step, ta and tb are each independently usually 0.1 to 1 second, preferably 0.1 to 0.5 second, more preferably 0.1 to 0.3 second.

  In this process, when the rotary tool 16 enters a predetermined depth, the pushing movement of the rotary tool 16 is stopped.

(Stirring maintenance step C3)
The agitation maintaining step C3 of this embodiment is the same as the agitation maintaining step C3 of the first embodiment except that no pressure is applied to the metal member in order to adopt the position control method. Specifically, as shown in FIG. 6, without applying pressure to the metal member 11 by the rotating tool 16, the rotating tool is moved to the fifth rotational speed at the position where the rotating tool 16 is entered in the pushing and stirring step C <b> 2. While rotating at (r5), hold only for the first holding time (j1). Thereby, generation | occurrence | production of frictional heat is suppressed and the resin member 12 fully solidifies.

  In the agitation maintaining step C3, the rotary tool 16 is held at the predetermined position at the fifth rotation speed (r5) and held for the first holding time (for example, 2 to 4 seconds).

  The amount of heat applied in this step is mainly determined by the magnitude of the fifth rotation number r5 of the rotary tool and the length of the first holding time j1.

  The first holding time j1 of the rotating tool in the stirring maintaining step C3 is set from the viewpoint of the control of the heat amount, sufficient solidification of the resin member 12 as described above, and productivity, and the value is 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, the melting point of the resin member 12, 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 and a resin member 12 having a melting point described later are used, the holding time j1 in the stirring and maintaining step C3 is preferably 4 seconds or less. The fifth rotation speed r5 of the rotary tool is preferably 2500 rpm or less. The holding time of 0 seconds means that the stirring and maintaining step C3 may not be performed in this embodiment. This is because the amount of heat can be controlled and the temperature of the lower portion 60 immediately below the rotary tool in the resin member can be sufficiently reduced even by the indentation stirring step C2 alone. In particular, when the amount of approach, the approach speed, and the rotational speed of the rotary tool are within the above ranges in the indentation stirring step C2, the holding time in the stirring maintaining step C3 is usually 2 seconds or more and 4 seconds or less.

  Also in this embodiment, after the final step is performed, solidification may be promoted by cooling. The cooling method is not particularly limited, and the cooling may be performed by standing or may be forcibly cooled from the outside.

(3) Metal Member The metal member 11 used in the present invention has a substantially flat plate shape as an overall shape in FIG. 1 and the like, but is not limited to this, and at least overlaps with the resin member 12. As long as the portion has a substantially flat plate 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 the bonding treatment; see FIG. 3) of the substantially flat plate-shaped portion that overlaps the resin member 12 in the metal member 11 is usually 0.5 to 4 mm, but is not limited thereto.

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

  Preferred metals constituting the metal member 11 are aluminum and an aluminum alloy.

(4) Resin member The resin member 12 used in the present invention contains a thermoplastic polymer and may further contain 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 FIG. 3) 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.

  The reinforcing fibers contained in the resin member 12 may be fibers that are uniformly contained and dispersed in the polymer in order to improve strength in the field of polymer-containing composite materials. The reinforcing fiber may be a continuous fiber or a discontinuous fiber. In the present invention, the reinforcing fiber is particularly preferably a discontinuous fiber.

  The reinforcing fibers are preferably contained in the resin member in a randomly oriented form, and the average fiber length L is usually 50 mm or less, particularly more than 1 mm and 50 mm or less, preferably more than 1 mm and 30 mm 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.

  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 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 150 to 300 ° C.
As the melting point Tm of the resin member 12, a value measured according to JIS 7121 is used.

(5) Bonded body The bonded body of the metal member 11 and the resin member 12 bonded by the bonding method of the present invention is sufficient in that both the lower portion 60 of the rotary tool and the outer peripheral portion 61 of the resin member 12 are sufficient with the metal member 11. Therefore, it has higher bonding strength.

  The fact that both the rotary tool direct lower portion 60 and the outer peripheral portion 61 of the resin member 12 are sufficiently bonded to the metal member 11 means that the metal member is forcibly separated from the bonded body obtained by the bonding method of the present invention. It can be found by observing the metal member side surface 121 of the resin member 12. Specifically, after the metal member is peeled off, the surface of the metal member side 121 of the resin member 12 is in the state of cohesive failure of the resin in both the surface of the direct lower portion 60 and the outer peripheral portion thereof. It is clear that it was fully joined. Cohesive failure is a state in which the surface layer portion of the resin remains on the metal side of the release surface. On the other hand, when the resin molecules are decomposed by overheating in the lower part 60 of the resin member 12, only the lower part is in the state of interfacial peeling, so it is clear that the surface was not sufficiently bonded to the metal member 11. is there. Interfacial peeling means that the resin surface layer portion does not remain on the metal side and peels at the interface between the metal and the resin.

  The case where the metal member and the resin member are joined in a dot shape without moving the pressing member (particularly the rotary tool) in the surface direction on the surface of the metal member has been described above. The present invention does not prevent application to the case where the metal member and the resin member are joined in a linear shape while moving the rotary tool in the plane direction (line joining). It is preferable to perform point joining from the viewpoint of improving the workability to a member having a three-dimensional shape.

[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.

[Metal members]
As the metal member, a flat plate member (length 100 mm × width 30 mm × thickness 1.2 mm) made of a 6000 series aluminum alloy was used.

[Rotation tool]
The rotary tool 16 (D1 = 10 mm, D2 = 2 mm, h = 0.5 mm; made of tool steel) shown in FIG. 2 was used.

[Example A1] (Load control method)
The joined body of the metal member 11 and the resin member 12 was manufactured by the following method.
First step:
The end of the metal member 11 and the end of the resin member 12 were overlapped as shown in FIG.

Second step:
First, as shown in FIG. 3, 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). r1 = 2500 rpm, p1 = 900 N, time = 1 second.

  Thereafter, as shown in FIG. 6, 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 (indentation stirring step C2). At this time, according to the method (i-1), as shown in FIG. 7, while rotating the rotary tool at 3000 rpm (r2), the drive unit i-1a (ta = 0.2 seconds) is pressed at 3000 N (p2). Then, the drive unit i-1b (tb = 0.2 seconds) in which the rotating tool is rotated at 3000 rpm and pressed at 1500 N was periodically repeated for 4 seconds (t2).

  Next, as shown in FIG. 6, the rotation operation of the rotary tool 16 was continued at a position where the rotary tool 16 was advanced to a depth that did not reach the joining boundary surface 13 (stirring maintaining step C3). r3 = 2000 rpm, p3 = 500 N, time = 2 seconds.

In the indentation stirring step, the temperature T ₆₀ (interface temperature at P ₆₀ in FIG. 3) and the temperature T ₆₁ of the outer peripheral portion ₆₁ (interface temperature at P ₆₁ in FIG. 3) of the resin member 12 immediately below the rotary tool are set. When measured, the change with time shown in FIG. 4 was shown. The temperature T ₆₀ of the immediately lower portion 60 reaches the joining contribution range (200 to 300 ° C.) at the initial stage of the indentation stirring process, and the temperature T ₆₁ of the outer peripheral portion 61 reaches the joining contribution range at the end of the indentation stirring process. After reaching the temperature, it remained within the joining contribution range until the stirring maintaining step. _{Incidentally, P 60} is the measured point on the axis of the rotational tool _{16, P 61} is the measuring point distance 10mm from _{P 60.}

  Next, the rotary tool 16 was separated from the metal member 11 and allowed to cool down to obtain a joined body.

(Joint strength)
It was measured based on Class A shear strength defined in JIS Z3140 “Spot Weld Inspection Method” (particularly applicable to members requiring strength). Specifically, as shown in FIG. 13, the joined body of the metal member 11 and the resin member 12 was disposed 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: 6.0 kN ≦ S;
O; 3.5 kN ≦ S <6.0 kN;
Δ: 2.5 kN ≦ S <3.5 N; (no problem in practical use)
X: S <2.5 kN (problem in practical use).

(Decomposition temperature)
It was 335 degreeC when the decomposition temperature of the resin member was measured with the following method. The decomposition of the resin is determined by the temperature and the time exposed to that temperature. The decomposition temperature of polypropylene (PP) is approximately 288 ° C, but up to 335 ° C is acceptable for a short time.
The bonding between the resin member and the metal member and the measurement of the bonding strength were performed by the same method as in Example A1, except that the second step was performed by the following method. At that time, in the following second step, the temperature T ₆₀ (interface temperature at P ₆₀ in FIG. 3) of the resin member 12 directly below the rotary tool 60 is adjusted by adjusting the load and rotation speed in the indentation stirring process. Various temperatures were controlled, and the relationship between the temperature and the adhesive strength is shown in FIG. The peak temperature in FIG. 14 is taken as the decomposition temperature. T ₆₀ is the maximum temperature over time.

Second step:
As shown in FIG. 3, the rotary tool 16 was rotated in a state where only the tip of the rotary tool 16 was in contact with the surface portion of the metal member 11 (preheating process: load 900 N, pressurization time 1.00 seconds, tool Rotation speed 3000 rpm).
Thereafter, as shown in FIG. 6, the rotary tool 16 was pushed into the metal member 11 and entered to a depth that did not reach the joint boundary surface 13 between the metal member 11 and the resin member 12 (indentation stirring step: load 1500 to 2500 N). Pressurization time 4 seconds, tool rotation speed 500-3000 rpm.
Next, as shown in FIG. 6, the rotation operation of the rotary tool 16 was continued at a position where the rotary tool 16 was advanced to a depth that did not reach the joining boundary surface 13 (stirring maintaining step: load 500 N, pressurization time 2). 75 seconds, tool rotation speed 3000 rpm).
Next, the rotary tool 16 was separated from the metal member 11 and allowed to cool down to obtain a joined body.

[Comparative Example A1]
Except that the second step was performed by the following method, the resin member and the metal member were joined and the joined body was evaluated by the same method as in Example A1.

Second step:
A preheating step was performed in the same manner as in Example A1.
The indentation stirring step was performed without controlling the amount of heat. Specifically, the indentation stirring step was performed in the same manner as in Example A1, except that the load was kept constant at 3000 N, the rotation speed was kept constant at 3000 rpm, and the pressurization time was 4 seconds. It was.
The stirring maintenance step was performed in the same manner as in Example A1.

[Example B1] (Position control method)
Except that the second step was performed by the following method, the resin member and the metal member were joined and the joined body was evaluated by the same method as in Example A1.

Second step:
Without performing the preheating step C1, as shown in FIG. 6, the rotary tool 16 was pushed into the metal member 11 to a depth not reaching the joint boundary surface 13 between the metal member 11 and the resin member 12 (indentation stirring). Step C2). At this time, according to the method (ii-1), as shown in FIG. 10, while rotating the rotary tool at 3000 rpm (r4), the drive unit ii-1a (ta = 0.3) is entered at 20 mm / min (v1). Second) and a drive unit ii-1b (tb = 0.3 seconds) for entering at a speed of 5 mm / min while rotating the rotary tool at 3000 rpm until the approach amount reaches 0.8 mm (d1). Repeated.

  Next, as shown in FIG. 6, 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 maintaining step C3: holding time 1.0 second). Tool rotation speed 2000 rpm).

[Comparative Example B1]
Except that the second step was performed by the following method, the resin member and the metal member were joined and the joined body was evaluated by the same method as in Example B1.

Second step:
The indentation stirring step was performed without controlling the amount of heat. Specifically, the indentation stirring step was performed by the same method as in Example B1, except that the approach speed was kept constant at 20 mm / min and the rotation speed was kept constant at 3000 rpm.
The stirring maintenance step was performed in the same manner as in Example B1.

  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 60: Resin at the interface between metal member and resin member Directly below the rotating tool of the member 61: Outer peripheral portion of the resin member immediately below the rotating tool 100: Jig for measuring the bonding strength 110: Directly below the rotating tool of the metal member P: Pressing area (scheduled pressing area)
121: Metal member side surface of resin member

Claims (18)

The metal member and the resin member are overlapped, pressure is applied to the resin member by pressing from the metal member side by the pressing member, heat is applied to soften and melt the resin member, and then solidified to perform bonding. It is a joining method of a metal member and a resin member by a hot-pressure joining method,
A joining method between a metal member and a resin member, wherein the joining is performed while changing the amount of heat applied.   The joining is performed while changing the amount of heat to be applied in pulses so that an interface temperature between the resin member and a metal member immediately below the pressing member is controlled to be equal to or lower than a decomposition temperature (Td) of the resin member. The joining method of the metal member and resin member of description. 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, softening and melting the resin member by the frictional heat, A friction stir welding method including a second step of solidifying and joining the metal member and the resin member;
The method for joining a metal member and a resin member according to claim 1 or 2, wherein the second step is performed while changing a pulse of the amount of heat applied by controlling a driving condition of the rotary tool.   The method for joining a metal member and a resin member according to claim 3, wherein the driving condition of the rotating tool is a pressing driving condition and / or a rotating driving condition of the rotating tool. Adopting a load control method in the second step,
5. The metal member and the resin member according to claim 3, wherein the driving condition of the rotating tool is one or more driving conditions selected from the group consisting of a load of the rotating tool, a pressing time, and a rotation speed. Joining method. The second step includes
A preheating step of rotating the rotary tool in a state where only the tip of the rotary tool is in contact with the surface of the metal member;
A pushing agitation step of pushing the rotating tool into the metal member and entering the metal member and the resin member to a depth not reaching the joining boundary surface; and a position where the rotating tool is entered in the pushing agitation step. Including an agitation maintaining step for continuing the rotation operation,
The indentation stirring step is performed while controlling the one or more driving conditions selected from the group consisting of the load of the rotating tool, the pressing time, and the number of rotations and changing the amount of heat to be applied in pulses. The joining method of the metal member and resin member of description. In the indentation stirring step, the second pressurizing time is a driving in which the rotary tool is rotated at a second rotation speed (r2) or less and pressed at a second load (p2) or less greater than the first load (p1). The method for joining the metal member and the resin member according to claim 6, wherein only the step (t2) is performed and the method is selected from the following methods:
(I-1) A drive unit i-1a for rotating the rotary tool at r2 and pressing it at p2, and a drive unit i-1b for rotating the rotary tool at r2 and pressing it at 0.7 × p2 or less, t2 Repeat only;
(I-2) A drive unit i-2a for rotating the rotary tool at r2 and pressing it at p2, and a drive unit i-2b for pressing the rotary tool at p2 while rotating it at 0.5 × r2 or less. And (i-3) drive unit i-3a for rotating the rotating tool at r2 and pressing at p2, and pressing at 0.7 × p2 or less while rotating the rotating tool at 0.7 × r2 or less The driving unit i-3b is repeated for t2. The second load (p2) is adjusted in the range of 1500N to 3000N,
The second rotational speed (r2) is adjusted in a range of 2500 rpm to 3500 rpm,
The method for joining a metal member and a resin member according to claim 7, wherein the second pressurization time (t2) is adjusted in a range of 2 seconds to 4 seconds. In the methods (i-1) to (i-3),
The ratio tb / ta between the drive unit time ta of the drive unit i-1a and the drive unit time tb of the drive unit i-1b, the drive unit time ta of the drive unit i-2a and the drive of the drive unit i-2b The ratio tb / ta to the unit time tb and the ratio tb / ta between the drive unit time ta of the drive unit i-3a and the drive unit time tb of the drive unit i-3b are 0.5 to 2. Item 9. A method for joining a metal member and a resin member according to item 7 or 8. Adopting a position control method in the second step,
The metal member and the resin according to claim 3 or 4, wherein the driving condition of the rotating tool is one or more driving conditions selected from the group consisting of an approach speed, an approach amount, a holding time, and a rotation speed of the rotating tool. Joining method with member. The second step includes
A pushing and stirring step of pushing the rotating tool into the metal member to enter a depth not reaching the joint interface between the metal member and the resin member; and a rotating tool at a position where the rotating tool is entered in the pushing and stirring step. Agitation maintaining step of holding while rotating;
Including
Controlling the one or more driving conditions selected from the group consisting of the approach speed, the approach amount, the holding time, and the rotation speed of the rotating tool to perform the indentation stirring step while changing the amount of heat to be applied in pulses. Item 11. A method for joining a metal member and a resin member according to Item 10. In the indentation stirring step, the rotary tool is rotated at the fourth rotation speed (r4) or less and is made to enter the first approach speed (v1) or less until the first approach amount (d1) is reached. The method for joining a metal member and a resin member according to claim 11 according to one selected method:
(Ii-1) Enter a drive unit ii-1a that enters at v1 while rotating the rotary tool at r4, and a drive unit ii-1b that enters at 0.5 × v1 or less while rotating the rotary tool at r4 Repeat until the amount reaches d1;
(Ii-2) A drive unit ii-2a that enters at v1 while rotating the rotary tool at r4 and a drive unit ii-2b that enters at v1 while rotating the rotary tool at 0.8 × r4 or less are entered. Repeat until the amount reaches d1; and (ii-3) drive unit ii-3a that rotates the rotating tool at r4 and enters at v1, and 0.5 × while rotating the rotating tool at 0.8 × r4 or less. The drive unit ii-3b to be entered at v1 or less is repeated until the approach amount reaches d1. The fourth rotation speed (r4) is adjusted in a range of 2500 rpm to 3500 rpm,
The first approach speed (v1) is adjusted within a range of 5 to 50 mm / min;
The metal member and the resin according to claim 12, wherein the first entry amount (d1) is adjusted in a range of 0.5 × T to 0.9 × T, where T is the thickness of the metal member. Joining method with member. In the methods (ii-1) to (ii-3),
The ratio tb / ta between the drive unit time ta of the drive unit ii-1a and the drive unit time tb of the drive unit ii-1b, the drive unit time ta of the drive unit ii-2a and the drive of the drive unit ii-2b The ratio tb / ta to the unit time tb and the ratio tb / ta between the drive unit time ta of the drive unit ii-3a and the drive unit time tb of the drive unit ii-3b are 0.5-2. Item 14. A method for joining a metal member and a resin member according to Item 12 or 13.   The joining method of the metal member and resin member in any one of Claims 1-14 whose thickness T of the said metal member is 0.5-4 mm. The metal member is made of aluminum or an aluminum alloy,
The joining method of the metal member and resin member in any one of Claims 1-15 in which the said resin member has melting | fusing point Tm of 150-300 degreeC. The metal member and the resin member are overlapped, pressure is applied to the resin member by pressing from the metal member side by the pressing member, heat is applied to soften and melt the resin member, and then solidified to perform bonding. A device for joining a metal member and a resin member by a hot-pressure joining method,
A joining apparatus between a metal member and a resin member, including a drive control device that controls driving of the pressing member so as to perform the joining while changing the amount of heat applied.   The joining apparatus of the metal member and resin member of Claim 17 for implementing the joining method of the metal member and resin member in any one of Claims 1-16.

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