JP7050462B2 - How to join members to be joined - Google Patents

Description

The present invention relates to a method for joining members to be joined, which is used for joining members to be joined made of fiber reinforced resin (FRTP) using a thermoplastic resin as a base material.

As a conventional method for joining members to be joined, for example, there is one described in Patent Document 1. The joining method described in Patent Document 1 is a method of joining two resin members by ultrasonic spot welding, and a pin-shaped horn having a pointed tip is used. The resin member is a fiber-reinforced composite material in which fibers are oriented in one direction in a matrix resin made of a thermoplastic resin. Then, in the joining method, the horn is pressed from one resin member side and ultrasonic vibration is applied to the horn, and the horn is made to enter to a position exceeding 50% of the thickness of the other resin member, and the resin members are joined to each other. Is melt-joined.

Japanese Unexamined Patent Publication No. 2016-144870

However, in the conventional joining method as described above, since the members to be joined are melt-bonded only by the frictional heat of the side wall of the pin-shaped horn, a wide joining area capable of improving the joining strength can be obtained. There was a problem that it was difficult, and it was a problem to solve such a problem.

The present invention has been made by paying attention to the above-mentioned conventional problems, and secures a wide joining area when joining members to be joined made of a fiber-reinforced resin (FRTP) using a thermoplastic resin as a base material. It is an object of the present invention to provide a joining method of a member to be joined, which can realize an improvement in joining strength.

The method for joining members to be joined according to the present invention is a method for joining members to be joined made of a fiber-reinforced resin using a thermoplastic resin as a base material, and has a pin portion to be pushed into the member to be joined and a pin portion. Use a horn to which ultrasonic vibration is applied in the direction along the axis of . The method of joining the members to be joined includes the first step of generating a viscous body at both interfaces in a state where the members to be joined are overlapped with each other, and the molecular motion of the viscous body is promoted to generate heat of the viscous body. It is equipped with a second step to make it
The first step is characterized in that the pin portion of the horn is pushed from one side of the member to be joined to generate a viscous body at the interface between the members to be joined by ultrasonic vibration of the pin portion .

The method for joining a member to be joined according to the present invention is a method of joining members made of a fiber-reinforced resin using a thermoplastic resin as a base material, in which a horn pushed in from one side of the member to be joined in the first step. A viscous body is generated at the interface between the members to be joined by the ultrasonic vibration of the pin portion, and the degree of freedom of the molecule is increased. Then, in the second step, the joining method promotes the molecular motion of the viscous body to surely generate heat of the viscous body. That is, in the joining method, the viscous body is heated by utilizing the frictional heat between the molecules, and the melting range at the interface is expanded in the radial direction. As a result, according to the above-mentioned joining method, a wide joining area can be stably secured at the interface between the members to be joined, and the joining strength can be improved.

It is a figure explaining the 1st Embodiment of the joining method of the member to be joined, and is the cross-sectional view (A)-(C) which shows the process from before joining to joining, respectively. It is sectional drawing explaining the 2nd Embodiment of the method of joining a member to be joined. It is sectional drawing explaining the 3rd Embodiment of the method of joining a member to be joined. It is sectional drawing explaining the 4th Embodiment of the method of joining a member to be joined. It is sectional drawing explaining 5th Embodiment of the method of joining a member to be joined. It is sectional drawing explaining the 6th Embodiment of the method of joining a member to be joined. It is a figure explaining the test piece used for the strength test, and is the top view and the side view of the test piece for testing the tensile strength in a shearing direction of a joint interface. It is a graph explaining the result of the strength test.

<First Embodiment>
FIG. 1 is a diagram illustrating a first embodiment of a method for joining members to be joined according to the present invention.
The method of joining the members to be joined is to join the members 1 and 2 to be joined made of fiber reinforced resin (FRTP) using a thermoplastic resin as a base material.

The thermoplastic resin that is the base material of the members to be joined 1 and 2 is not particularly limited, and for example, a polyolefin-based resin, a polyamide-based resin, a polyester-based resin, and the like can be used.

The reinforcing fibers of the members 1 and 2 to be joined are not particularly limited, but for example, carbon fibers or carbon-containing fibers having high strength and light weight are suitable for structural materials of automobiles. In this case, the material of the members 1 and 2 to be joined is a carbon fiber reinforced resin (CFRTP) using a thermoplastic resin as a base material. In addition, the joining method of the present invention can of course be applied to joining a fiber reinforced resin (FRTP) or a glass fiber reinforced resin (GFRTP) using a thermoplastic resin as a base material.

The members 1 and 2 to be joined can be in various forms as a whole, but at least the parts to be joined may be in a form in which an interface in close contact with each other is formed as shown in FIG. Alternatively, it can be made into a plurality of planes or curved surfaces.

As a general rule, the joining device used in the above joining method includes a viscous body generation mechanism that generates a viscous body at both interfaces in a state where the members to be joined 1 and 2 are overlapped with each other, and promotes the molecular motion of the viscous body. It is provided with a molecular activation mechanism that causes the viscous body to generate heat.

As shown in FIG. 1A, the joining device of this embodiment has a base 11 that can abut on the surface of one of the members 1 to be joined, and a base 11 that protrudes from the base 11 and can be pushed into the members 1 and 2 to be joined. A horn H having a pin portion 12 and to which ultrasonic vibration VW is applied in a direction along the axis of the pin portion 12 is provided. In the horn H, the base 11 constitutes a molecular activation mechanism, and the pin portion 12 constitutes a viscous body formation mechanism.

The base portion 11 has a flat columnar shape, while the pin portion 12 has a circular cross section with a pointed tip. The horn H has a base portion 11 and a pin portion 12 arranged on a coaxial line to integrate both portions, and may have a mounting portion (not shown) to the head of the joining device.

Here, in the above-mentioned joining method, as a more preferable embodiment, the relationship between the thickness T1 of one member to be joined 1 and the thickness T2 of the other member 2 to be joined is T1 ≧ T2, and the horn H When the contact surface 11A of the base portion 11 with the member to be joined is circular, the area of the contact surface 11A of the base portion 11 can be π × ((2√T2) / 2) ² or more.

Further, although not shown, the joining device is provided with a mechanism for raising and lowering the head equipped with the horn H, a booster for applying ultrasonic vibration VW to the horn H, and the like, and is provided on the back side of the members 1 and 2 to be joined. It may be configured to have a mechanism for holding (the opposite side of the horn H).

The joining method using the above-mentioned joining device includes the first step of generating a viscous body at both interfaces in a state where the members 1 and 2 to be joined are overlapped with each other, and the viscous body is promoted by promoting the molecular motion of the viscous body. It is equipped with a second step of generating heat.

That is, in the first step, the pin portion 12 of the horn is pushed from one side of the member to be joined 1 and the viscous body P is generated at the interface between the members to be joined 1 and 2 by the ultrasonic vibration VW of the pin portion 12.

More specifically, as shown in FIG. 1 (A), the horn H is advanced (lowered) with the members 1 and 2 to be joined overlapped with each other, and as shown in FIG. 1 (B). An ultrasonic vibration VW in the direction along the axis is applied to the horn H, and the pin portion 12 is pushed into one of the members to be joined 1. At this time, in the above-mentioned joining method, the viscous body P is effectively generated at the interface portion between the members to be joined 1 and 2 by the frictional heat with the side wall of the pin portion 12, and the degree of freedom of the molecule is increased. do.

Here, the viscous body P in the above-mentioned joining method is mainly a thermoplastic resin which is a base material of the members to be joined 1 and 2, and the thermoplastic resin is melted. However, the viscous body P can also be generated from another material interposed between the members to be joined 1 and 2.

Next, in the second step, the base 11 of the horn H is brought into contact with the surface of one of the members to be joined 1, and the vertical ultrasonic vibration VW of the base 11 promotes the molecular motion of the viscous body P to promote the viscous body. Make sure that P is heated.

More specifically, as shown in FIG. 1C, the horn H is advanced until the contact surface 11A of the base 11 abuts on one of the members to be joined 1. Thereby, in the above-mentioned joining method, the molecular motion of the viscous body P is promoted by the vertical ultrasonic vibration VW of the horn H to generate heat of the viscous body P. That is, in the above joining method, the viscous body P is heated by utilizing the frictional heat between the molecules in the viscous body P, and as shown by the reference numeral PA in FIG. 1 (C), the melting range at the interface is set in the radial direction. Enlarge.

After that, in the above-mentioned joining method, the ultrasonic vibration VW of the horn H is stopped to temporarily hold the state, and if the molten portion is cured, the joining is completed, and at an appropriate time before or after the curing of the fused portion. The horn H is separated from the members 1 and 2 to be joined.

In this way, the joining method described in the above embodiment can stably secure a wide joining area at the interface between the members to be joined 1 and 2 by adopting the first step and the second step. Achieves improved joint strength. Further, in the joining structure in which one member to be joined 1 and the other member 2 to be joined are joined by the above-mentioned joining method, the joining strength between the members to be joined 1 and 2 is improved as a sufficient joining area is secured. Can be realized.

Further, in the above-mentioned joining method, since the viscous body P is a thermoplastic resin which is a base material of the members to be joined 1 and 2, the first step and the first step are made by stacking the members 1 and 2 to be joined with each other. By performing only two steps, the members 1 and 2 to be joined can be easily joined in a short time as if spot welding was performed on the metal member.

At this time, in the above-mentioned joining method, since the vertical ultrasonic vibration VW is applied to the horn H, it is possible to sequentially join the members 1 and 2 to be joined at predetermined intervals to ensure that both are joined. That is, when sequentially joining the members 1 and 2 to be joined at predetermined intervals, the degree of freedom in the in-plane direction (direction parallel to the plane) decreases in the vicinity of the already joined portions. On the other hand, in the joining method using the vertical ultrasonic vibration VW, even in the vicinity of the already joined portion, it is not affected by the decrease in the degree of freedom in the in-plane direction. The viscous body P is generated and the viscous body P is surely generated, and a high-quality joint portion can be stably formed.

Further, in the above joining method, the first step of generating the viscous body P and the heat generation of the viscous body are generated by using the horn H having the base portion 11 and the pin portion 12 and to which the ultrasonic vibration VW is applied. It is possible to continuously carry out the second step of causing the vibration. As a result, in the above-mentioned joining method, it is possible to secure a sufficient joining area, improve the joining strength, and shorten the joining time.

Further, in the above-mentioned joining method, the relationship between the thickness T1 of one of the members to be joined and the thickness T2 of the other member to be joined is T1 ≧ T2, and the contact surface 11A of the base 11 in the horn H is circular. In this case, since the area of the contact surface 11A is π × ((2√T2) / 2) ² or more, a sufficient melting area can be secured and high bonding strength can be obtained. This is because when joining steel plates or aluminum alloys, the nugget diameter 5√t1 is class A quality (JISZ3140), so in the joining method, the area is defined with the nugget diameter 2√t as the minimum. .. In the bonding between CFRTPs, it is possible to realize high bonding strength by controlling the nugget diameter within this range.

Further, the joining device applicable to the above joining method includes a viscous body forming mechanism and a molecular activation mechanism. In particular, the joining device of the above embodiment has a base portion 11 that can abut on the surface of one of the members to be joined 1 as a molecular activation mechanism, and a viscous body generation mechanism that protrudes from the base portion 11 and is pushed into the members to be joined 1 and 2. The horn H has a possible pin portion 12 and is provided with an ultrasonic vibration VW in a direction along the axis of the pin portion 12.

The joining device uses a horn H that integrates a viscous body generation mechanism (pin portion 12) and a molecular activation mechanism (base portion 11) to make the device structure extremely simple and compact. , The members 1 and 2 to be joined can be joined to each other in a short time and with high strength.

(Example 1)
As a bonding device, a longitudinal vibration type ultrasonic bonding device equipped with the horn H shown in FIG. 1 was used. The materials of the members 1 and 2 to be joined were carbon fibers used as reinforcing fibers, and the carbon fiber content was 40% by weight and the fiber length was 0.3 mm to 05 mm. The pin portion 12 of the horn H has a root diameter of 4.5 mm, a tip diameter of 4.0 mm, and a protrusion height of 5.0 mm. The joining conditions were a pressing force of 300 kPa, an amplitude of 80%, a pushing depth of 5 mm, a joining time of 1.5 seconds, and a holding time of 5.0 seconds after joining in the atmosphere. As a result of joining the members 1 and 2 to be joined under the above conditions, it was confirmed that the tensile strength of the joined portion per place was 5.2 kN, and sufficient joining strength could be obtained.

Hereinafter, the second to sixth embodiments of the method for joining the members to be joined according to the present invention will be described with reference to FIGS. 2 to 6. In each of the following embodiments, the same components as those in the first embodiment are designated by the same reference numerals, and detailed description thereof will be omitted.

<Second Embodiment>
FIG. 2 is a diagram illustrating a method of joining members to be joined and a second embodiment of a joining device according to the present invention. The joining device of the illustrated example includes an infrared heater 13 as a viscous body generation mechanism that generates a viscous body P at both interfaces in a state where the members 1 and 2 to be joined are overlapped with each other. Further, the joining device includes a horn H provided with a base 14 capable of abutting on the surface of one of the members to be joined 1 as a molecular activation mechanism that promotes the molecular motion of the viscous body P to generate heat of the viscous body P. I have. A vertical ultrasonic vibration VW along the thickness direction of the members 1 and 2 to be joined is applied to the horn H.

The joining method using the above-mentioned joining device includes the first step of generating a viscous body at both interfaces in a state where the members 1 and 2 to be joined are overlapped with each other, and the viscous body is promoted by promoting the molecular motion of the viscous body. It is equipped with a second step of generating heat.

That is, in the first step, infrared heating is performed between the members 1 and 2 to be joined by infrared IR emitted from the infrared heater 13, and the interface between the members 1 and 2 to be joined is effectively heated to form the viscous body P. It is generated to increase the degree of freedom of the molecule of the viscous body P. Next, in the second step, the base 14 of the horn H is brought into contact with the surface of one of the members to be joined 1, and the ultrasonic vibration VW of the base 14 promotes the molecular motion of the viscous body P to cause friction between the molecules. The viscous body P is surely generated by using heat, and the melting range PA at the interface is expanded in the radial direction.

In this way, the above-mentioned joining method can stably secure a wide joining area at the interface between the members to be joined 1 and 2, and can realize the improvement of the joining strength. In the illustrated example, the infrared heater 13 heats a wide range with infrared rays, but since the viscous body P is heated to expand the melting range Pa in the second step later, the narrow range is intensively heated with infrared rays. Therefore, the viscous body P may be generated in a range smaller than that in the illustrated example.

(Example 2)
As a bonding device, an infrared heater 13 shown in FIG. 2 and a longitudinal vibration type ultrasonic bonding device provided with a horn H were used. The materials of the members 1 and 2 to be joined were carbon fibers used as reinforcing fibers, and the carbon fiber content was 40% by weight and the fiber length was 0.3 mm to 05 mm. The joining conditions were a pressing force of 300 kPa, an amplitude of horn H of 80%, a joining time of 2.0 seconds, and a holding time of 5 seconds after joining in the atmosphere. As a result of joining the members 1 and 2 to be joined under the above conditions, it was confirmed that the tensile strength of the joined portion per place was 4 kN, and sufficient joining strength could be obtained.

<Third Embodiment>
FIG. 3 is a diagram illustrating a method of joining members to be joined and a third embodiment of a joining device according to the present invention. The joining device of the illustrated example includes a laser oscillator 15 as a viscous body generation mechanism that generates a viscous body P at both interfaces in a state where the members 1 and 2 to be joined are overlapped with each other. Further, the joining device includes a horn H provided with a base 14 capable of abutting on the surface of one of the members to be joined 1 as a molecular activation mechanism that promotes the molecular motion of the viscous body P to generate heat of the viscous body P. I have. A vertical ultrasonic vibration VW along the thickness direction of the members 1 and 2 to be joined is applied to the horn H.

In the joining method using the above-mentioned joining device, in the first step, laser heating is performed between the joined members 1 and 2 by the laser beam L oscillated from the laser oscillator 15, and the interface between the joined members 1 and 2 is joined. Is effectively heated to generate the viscous body P, and the degree of freedom of the molecule of the viscous body P is increased. Next, in the second step, the base 14 of the horn H is brought into contact with the surface of one of the members to be joined 1, and the vertical ultrasonic vibration VW of the base 14 promotes the molecular motion of the viscous body P to promote the molecular motion between the molecules. The viscous body P is surely generated by using the frictional heat of the above, and the melting range PA at the interface is expanded in the radial direction.

In this way, the above-mentioned joining method can stably secure a wide joining area at the interface between the members to be joined 1 and 2, and can realize the improvement of the joining strength. In the illustrated example, the laser oscillator 15 laser-heats a wide range, but the narrow range may be intensively laser-heated as in the second embodiment.

(Example 3)
As a bonding device, a laser oscillator 15 shown in FIG. 3 and a longitudinal vibration type ultrasonic bonding device provided with a horn H were used. The materials of the members 1 and 2 to be joined were carbon fibers used as reinforcing fibers, and the carbon fiber content was 40% by weight and the fiber length was 0.3 mm to 05 mm. The joining conditions were a pressing force of 300 kPa, an amplitude of horn H of 80%, a joining time of 2.5 seconds, and a holding time of 5 seconds after joining in the atmosphere. As a result of joining the members 1 and 2 to be joined under the above conditions, it was confirmed that the tensile strength of the joined portion per place was 4.2 kN, and sufficient joining strength could be obtained.

<Fourth Embodiment>
FIG. 4 is a diagram illustrating a method of joining members to be joined and a fourth embodiment of a joining device according to the present invention. The joining device of the illustrated example includes an induction heating device 16 as a viscous body generation mechanism that generates a viscous body P at both interfaces in a state where the members 1 and 2 to be joined are overlapped with each other. The induction heating device 16 performs high-frequency heating among the induction heating. Further, the joining device includes a horn H provided with a base 14 capable of abutting on the surface of one of the members to be joined 1 as a molecular activation mechanism that promotes the molecular motion of the viscous body P to generate heat of the viscous body P. I have. A vertical ultrasonic vibration VW along the thickness direction of the members 1 and 2 to be joined is applied to the horn H.

In the joining method using the above-mentioned joining device, in the first step, the space between the members 1 and 2 to be joined is heated at high frequency by the magnetic field B generated by the induction heating device 16, and the interface between the members 1 and 2 to be joined is heated. Is effectively heated to generate the viscous body P, and the degree of freedom of the molecule of the viscous body P is increased. Next, in the second step, the base 14 of the horn H is brought into contact with the surface of one of the members to be joined 1, and the vertical ultrasonic vibration VW of the base 14 promotes the molecular motion of the viscous body P to promote the molecular motion between the molecules. The viscous body P is surely generated by using the frictional heat of the above, and the melting range PA at the interface is expanded in the radial direction. In this way, the above-mentioned joining method can stably secure a wide joining area at the interface between the members to be joined 1 and 2, and can realize the improvement of the joining strength.

(Example 4)
As the bonding device, an induction heating device 16 shown in FIG. 4 and a longitudinal vibration type ultrasonic bonding device provided with a horn H were used. The materials of the members 1 and 2 to be joined were carbon fibers used as reinforcing fibers, and the carbon fiber content was 40% by weight and the fiber length was 0.3 mm to 05 mm. The joining conditions were a pressing force of 300 kPa, an amplitude of horn H of 80%, a joining time of 2.8 seconds, and a holding time of 5 seconds after joining in the atmosphere. As a result of joining the members 1 and 2 to be joined under the above conditions, it was confirmed that the tensile strength of the joined portion per place was 4.2 kN, and sufficient joining strength could be obtained.

<Fifth Embodiment>
FIG. 5 is a diagram illustrating a method of joining members to be joined and a second embodiment of a joining device according to the present invention. As shown in FIG. 5A, the joining device has a horn H having a pin portion 12 as a viscous body generating mechanism for generating a viscous body P at both interfaces in a state where the members 1 and 2 to be joined are overlapped with each other. It is equipped with. Further, as shown in FIG. 5B, the joining device is a surface of the interface between the members to be joined 1 and 2 as a molecular activation mechanism that promotes the molecular motion of the viscous body P to generate heat of the viscous body P. It includes a horn 17 to which a lateral ultrasonic vibration HW along the inward direction is applied, and an anvil 18 that faces the horn 17 and holds the members 1 and 2 to be joined.

In the joining method using the above-mentioned joining device, in the first step, the frictional heat generated by the pin portion 12 of the horn H to which the vertical ultrasonic vibration VW is applied is effective between the members 1 and 2 to be joined. By heating, a viscous body P is generated at the interface between the members to be joined 1 and 2, and the degree of freedom of the molecule of the viscous body P is increased. Next, in the second step, the horn 17 is brought into contact with the surface of one of the members to be joined 1, and the molecular motion of the viscous body P is promoted by the ultrasonic vibration HW beside the horn 18, and the frictional heat between the molecules is generated. The viscous body P is surely generated to generate heat by utilizing the above, and the melting range PA at the interface is expanded in the radial direction. In this way, the above-mentioned joining method can stably secure a wide joining area at the interface between the members to be joined 1 and 2, and can realize the improvement of the joining strength.

(Example 5)
As a bonding device, an ultrasonic wave provided with a horn H (FIG. 5 (A)) to which a vertical ultrasonic vibration VW is applied and a horn 17 (FIG. 5 (B)) to which a horizontal ultrasonic vibration HW is applied. A joining device was used. The materials of the members 1 and 2 to be joined were carbon fibers used as reinforcing fibers, and the carbon fiber content was 40% by weight and the fiber length was 0.3 mm to 05 mm. The joining conditions were a pressing force of 300 kPa, an amplitude of the horn H of 80%, a pushing depth of the pin portion 12 of 4.0 mm, a joining time of 2.5 seconds, and a holding time of 5 seconds after joining in the atmosphere. As a result of joining the members 1 and 2 to be joined under the above conditions, it was confirmed that the tensile strength of the joined portion per place was 4.3 kN, and sufficient joining strength could be obtained.

<Sixth Embodiment>
FIG. 6 is a diagram illustrating a method of joining members to be joined and a sixth embodiment of a joining device according to the present invention. The joining device includes a horn H having a pin portion 12 as a viscous body generation mechanism for generating a viscous body P at both interfaces in a state where the members 1 and 2 to be joined are overlapped with each other. Further, the joining device includes a dielectric heating device 19 as a molecular activation mechanism that promotes the molecular motion of the viscous body P to generate heat of the viscous body P. The dielectric heating device 19 performs microwave heating among the dielectric heating.

In the joining method using the above-mentioned joining device, in the first step, the frictional heat generated by the pin portion 12 of the horn H to which the vertical ultrasonic vibration VW is applied is effective between the members 1 and 2 to be joined. By heating, a viscous body P is generated at the interface between the members to be joined 1 and 2, and the degree of freedom of the molecule of the viscous body P is increased. Next, in the second step, the molecular motion of the viscous body P is promoted by the microwave MW generated by the dielectric heating device 19, and as shown in FIG. 6B, the frictional heat generated by the rotational vibration between the molecules is used. The viscous body P is surely generated to generate heat, and the melting range PA at the interface is expanded in the radial direction. In this way, the above-mentioned joining method can stably secure a wide joining area at the interface between the members to be joined 1 and 2, and can realize the improvement of the joining strength.

(Example 6)
As the bonding device, an ultrasonic bonding device provided with a horn H to which the vertical ultrasonic vibration VW shown in FIG. 6A is applied, and an ultrasonic bonding device provided with a dielectric heating device 19 were used. The materials of the members 1 and 2 to be joined were carbon fibers used as reinforcing fibers, and the carbon fiber content was 40% by weight and the fiber length was 0.3 mm to 05 mm. The joining conditions were a pressing force of 300 kPa, an amplitude of the horn H of 80%, a pushing depth of the pin portion 12 of 4.0 mm, a joining time of 2.8 seconds, and a holding time of 5 seconds after joining in the atmosphere. As a result of joining the members 1 and 2 to be joined under the above conditions, it was confirmed that the tensile strength of the joined portion per place was 4.5 kN, and sufficient joining strength could be obtained.

As described in the second to sixth embodiments described above, in the joining method of the present invention, in the first step, among infrared heating by infrared IR, laser heating by laser light L, and induction heating by magnetic field B, By heating at least one, the interface between the members 1 and 2 to be joined can be effectively heated to generate the viscous body P. Further, in the second step, the molecular motion of the viscous body P is promoted by at least one of the lateral ultrasonic vibration HW and the microwave MW applied in the in-plane direction at the interface between the members 1 and 2 to be joined. The viscous body P can be reliably generated.

As described above, in the bonding method of the present invention, a wide bonding area can be stably secured by combining the viscous body generation mechanism used in the first step and the molecular activation mechanism used in the second step. , It is possible to improve the joint strength. The combination of the viscous body formation mechanism and the molecular activation mechanism can be appropriately selected in addition to the above-mentioned embodiments.

FIG. 7 is a diagram illustrating a test piece used in the strength test. In the illustrated test piece TP1, a pair of strip-shaped members 1 and 2 to be joined are arranged in a straight line, and one ends of both are joined to each other. This test piece TP1 applies a tensile load in opposite directions to the other ends of the members 1 and 2 to be joined, and evaluates the tensile strength in the shearing direction of the joining interface of the joining portion A. The members 1 and 2 to be joined have a thickness ST of 3 mm, a length SL of 100 mm, a width SW of 25 mm, and a length SS of the joint portion (overlapping portion) of 25 mm.

FIG. 8 is a graph illustrating the results of the strength test. In Comparative Example 1, a horn H having only the pin portion 12 is used, and the members 1 and 2 to be joined are joined to each other only by the vertical ultrasonic vibration VW of the pin portion 12. In Comparative Example 2, a horn H having only the base 11 is used, and the members 1 and 2 to be joined are joined to each other only by the vertical ultrasonic vibration VW of the base 11. In the embodiment of the present invention, a horn H having a base portion 11 and a pin portion 12 is used, and a viscous body is generated (first step) by the vertical ultrasonic vibration VW of the pin portion 12, and the vertical ultrasonic vibration of the base portion 11 is generated. The viscous body is heated by VW (second step) to join the members 1 and 2 to be joined.

As is clear from FIG. 8, in the joining method (Example) of the present invention, a wider joining area is stably secured at the interface of the members to be joined 1 and 2 as compared with Comparative Examples 1 and 2. The result was that a tensile strength significantly higher than that of Examples 1 and 2 was obtained. Further, it was found that the joining method of the present invention can obtain the same tensile strength as the joint portion between the steel plates.

The details of the structure of the joining method and joining device of the members to be joined according to the present invention are not limited to each of the above embodiments, and can be appropriately changed without departing from the gist of the present invention.

Further, in the first, fifth and sixth embodiments (FIGS. 1, 5 and 6), the pin portion 12 of the horn H penetrates one of the bonded members 1 and becomes the other bonded member 2. Although the state of being pushed in is shown, it is possible to generate the viscous body P at the bonding interface even when the pin portion 12 does not reach the other member to be joined 2. After that, in the bonding method, by generating heat of the viscous body P, the melting range PA is expanded and a wide bonding area PA is stably secured, whereby sufficient bonding strength can be obtained.

Further, in the second to fourth and sixth embodiments shown in FIGS. 2 to 4 and 6, for convenience, the infrared heater 13, the laser oscillator 15, the induction heating device 16 and the dielectric heating device 19 are attached to the other member to be joined. Shown on the 2nd side (lower side). The arrangement of these devices is such that the radiation direction of the infrared IR, the laser beam L and the microwave MW, and the formation of the magnetic field B with respect to the joint portion are optimized according to the shape and position of the members 1 and 2 to be joined. Set.

1 One member to be joined 2 The other member to be joined H Horn to which vertical ultrasonic vibration is applied P Viscous body PA Melting range 11 Base (molecular activation mechanism)
12-pin part (viscous body generation mechanism)
13 Infrared heater (viscous body generation mechanism)
14 Base 15 Laser oscillator (viscous body generation mechanism)
16 Induction heating device (viscous body generation mechanism)
17 Horn to which lateral ultrasonic vibration is applied (viscous body generation mechanism)
19 Dielectric heating device (viscous body generation mechanism)

Claims (7)

When joining members to be joined made of fiber reinforced resin using a thermoplastic resin as a base material,
Using a horn having a pin portion to be pushed into the member to be joined and to which ultrasonic vibration is applied in a direction along the axis of the pin portion.
In the first step of generating a viscous body at both interfaces in a state where the members to be joined are overlapped with each other,
A second step of promoting the molecular motion of the viscous body to generate heat of the viscous body is provided.
The first step is characterized in that the pin portion of the horn is pushed from one side of the member to be joined, and the viscous body is generated at the interface between the members to be joined by ultrasonic vibration of the pin portion. A method of joining members to be joined. When joining members to be joined made of fiber reinforced resin using a thermoplastic resin as a base material,
In the first step of generating a viscous body at both interfaces in a state where the members to be joined are overlapped with each other,
A second step of promoting the molecular motion of the viscous body to generate heat of the viscous body is provided.
The first step is a method for joining members to be joined, wherein the viscous body is generated at an interface between the members to be joined by at least one heating of infrared heating and induction heating. The method for joining a member to be joined according to claim 1 or 2, wherein the viscous body is a thermoplastic resin that is a base material of the member to be joined. Using a horn having a base with the pin portion protruding,
In the second step, the base of the horn is brought into contact with the surface of one of the members to be joined, and the ultrasonic vibration of the base promotes the molecular motion of the viscous body to generate heat. The method for joining members to be joined according to claim 1. The relationship between the thickness T1 of one of the members to be joined and the thickness T2 of the other member to be joined is T1 ≧ T2, and the contact surface of the base of the horn with the member to be joined is circular. If so,
The method for joining a member to be joined according to claim 4, wherein the area of the contact surface of the base is π × ((2√T2) / 2) ² or more. In the second step, at least one of ultrasonic vibration applied in the in-plane direction of the interface between the members to be joined and dielectric heating promotes the molecular motion of the viscous body to generate heat. The method for joining members to be joined according to claim 1 or 2, wherein the method is characterized. A device used in the method for joining members to be joined according to any one of claims 1 to 6 .
A viscous body generation mechanism that generates the viscous body at both interfaces in a state where the members to be joined are overlapped with each other.
It is equipped with a molecular activation mechanism that promotes the molecular motion of the viscous body and causes the viscous body to generate heat .
As the molecular activation mechanism, it has a base portion that can abut on the surface of one of the members to be joined, and a pin portion that protrudes from the base portion and can be pushed into the member to be joined as the viscous body generation mechanism. A joining device for members to be joined, characterized by having a horn to which ultrasonic vibration is applied in the direction along the axis of the portion .

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