Joint member formed by combining first member and second member in use of folding process

Abstract

To manufacture a joint member which can be easily formed into a hemming shape by a folding process using reinforcing fibers and thermoplastic resin, and easily recycled by not using an adhesive agent.SOLUTION: In a joint member formed by combining a first member and a second member, the first member contains reinforcing fibers and thermoplastic resin. In a cross-section perpendicular to a longitudinal direction of the joint member, the first member and the second member configure a closed cross-sectional shape. The first member is provided with one end portion and the other end portion in a width direction perpendicular to the longitudinal direction. The second member is provided with one end portion and the other end portion in the width direction perpendicular to the longitudinal direction. The joint member has a first folding portion in the one end portion of the first member or the one end portion of the second member, and has a second folding portion in the other end portion of the first member or the other end portion of the second member.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a joined member in which a first member and a second member are joined together, the first member and the second member being joined together by bending. [Background technology]

[0002] In recent years, development has been underway to join joining members using molded products obtained by compression molding reinforced fibers and thermoplastic resin. Patent Document 1 aims to quickly and easily assemble a structure consisting of a hat-shaped fiber-reinforced thermoplastic resin molded product and a metal molded product, and to ensure high joining strength.

[0003] On the other hand, Patent Documents 2 and 3 disclose a joining member in which two steel plate members are joined by bending as a method for joining two hat-shaped parts. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-34734 [Patent Document 2] Patent Publication No. 2021-31028 [Patent Document 3] Japanese Patent Application Publication No. 2018-114969 Summary of the Invention [Problem to be solved by the invention]

[0005] However, the bonded body described in Patent Document 1 is nothing more than two molded bodies simply welded together. Simply welding the two molded bodies together results in insufficient peel strength when used as, for example, an impact absorbing member, and therefore poor bonding strength.

[0006] The inventions described in Patent Documents 2 and 3 use metal, which requires a great deal of force for bending, resulting in excessive manufacturing costs. Furthermore, adhesive is required after bending, which increases the weight of the parts. Furthermore, because the products use both adhesive and metal, they are poorly recyclable.

[0007] Therefore, the object of the present invention is to create a joining member that can be easily formed into a hemmed shape by bending using reinforcing fibers and thermoplastic resin, and that can be easily recycled because no adhesive is used. [Means for solving the problem]

[0008] As a result of extensive investigations, the present inventors have found that the above problems can be solved by the following means, and have arrived at the present invention.

[0009] 1. A joining member in which a first member and a second member are combined, The first member includes reinforcing fibers and a thermoplastic resin, In a cross section perpendicular to the longitudinal direction of the joining member, the first member and the second member form a closed cross-sectional shape, The first member has one end and another end in a width direction perpendicular to the longitudinal direction, the second member has one end and the other end in a width direction perpendicular to the longitudinal direction, a first bent portion at one end of the first member or one end of the second member; A second bent portion is provided at the other end of the first member or the other end of the second member. Joining material. 2. 2. The joining member according to claim 1, wherein the second member contains a thermoplastic resin and reinforcing fibers. 3. The contact surface between one end of the first member and one end of the second member forms a contact surface area A1 formed by folding and a contact surface area B1 other than A1, The contact surface between the other end of the first member and the other end of the second member forms a contact surface area A2 formed by folding and a contact surface area B2 other than A2, 3. The joining member according to any one of 1 or 2, in which the first member and the second member are welded together, with the contact area A1 and / or the contact area A2 as a joining portion. 4. 4. The joining member according to item 3, wherein the contact area A1 and / or the contact area A2 is a welded portion. 5. One end of the first member and one end of the second member form a contact area A1 formed by folding and a contact area B1 other than A1, The other end of the first member and the other end of the second member form a contact area A2 formed by folding and a contact area B2 other than A2, 5. The joining member according to any one of 1 to 4, wherein the first member and the second member are welded together, with the contact area B1 and / or the contact area B2 being the welded portion. 6. No adhesive is used to join the first member and the second member. 6. The joining member according to any one of 1 to 5 above. 7. the first member includes reinforcing fibers and a thermoplastic resin; one end of the first member and the other end of the first member are bent to form the first bent portion and the second bent portion, respectively; One end of the second member is sandwiched between the first bent portion, The other end of the second member is sandwiched in the second bent portion. 7. The joining member according to any one of 1 to 6 above. 8. The first member and the second member contain reinforcing fibers and a thermoplastic resin, one end of the first member and the other end of the second member are bent to form the first bent portion and the second bent portion, respectively; One end of the second member is sandwiched between the first bent portion, The other end of the first member is sandwiched in the second bent portion. 7. The joining member according to any one of 1 to 6 above. 9. 9. A method for manufacturing a joint member according to any one of 1 to 8, preparing a first member precursor for forming the first member and a second member precursor for forming the second member; the first member precursor has one end and the other end in a width direction perpendicular to the longitudinal direction, the second member precursor has one end and the other end in a width direction perpendicular to the longitudinal direction, one end of the first member precursor or one end of the second member precursor is heated and bent to form a first bent portion; the other end of the first member precursor or the other end of the second member precursor is heated and bent to form a second bent portion; A manufacturing method for a joining member. 10. 10. The method for manufacturing a joining member according to item 9, When one end of the first member precursor or one end of the second member precursor is heated and folded, the one end of the first member and the one end of the second member form a contact area A1 by folding, when the other end of the first member precursor or the other end of the second member precursor is heated and folded, the other end of the first member and the other end of the second member form a contact area A2 by folding; In the contact surface region A1 and / or the contact surface region A2, the thermoplastic resin contained in the first member precursor or the second member precursor that has been heated and bent is inserted into and welded to the second member precursor or the first member precursor that has been sandwiched by the bending process. 9. A method for producing the joint member described in 8 above. 11. 11. A method for manufacturing a joining member according to claim 10, When heating and bending the sheet, a jig is used. By providing a wedge in the jig, the thermoplastic resin contained in the first member precursor or the second member precursor is forced into the first member precursor or the second member precursor sandwiched by a bending process. A manufacturing method for a joining member. 12. providing holes in the first member precursor and / or the second member precursor to be sandwiched by the bending processing portion; providing a convex portion in a portion to be folded of the first member precursor and / or a portion to be folded of the second member precursor; The protrusion is inserted into the hole and welded. 11. A method for manufacturing a joint member according to claim 10. 13. 10. The method for manufacturing a joining member according to 9, When one end of the first member precursor or one end of the second member precursor is heated and folded, the one end of the first member and the one end of the second member form a contact area A1 by folding, when the other end of the first member precursor or the other end of the second member precursor is heated and folded, the other end of the first member and the other end of the second member form a contact area A2 by folding; The contact area A1 and / or the contact area A2 is welded by applying ultrasonic waves. A manufacturing method for a joining member. 14. 14. The method for manufacturing a joined member according to item 13, wherein an energy director is provided on the first member precursor and / or the second member precursor that form the contact area A1 and / or the contact area A2, and ultrasonic waves are applied so as to melt the energy director. 15. 10. The method for manufacturing a joining member according to 9, When one end of the first member precursor or one end of the second member precursor is heated and folded, the one end of the first member and the one end of the second member form a contact area A1 by folding, One end of the first member and one end of the second member form a contact surface area B1 other than the contact surface area A1, when the other end of the first member precursor or the other end of the second member precursor is heated and folded, the other end of the first member and the other end of the second member form a contact area A2 by folding; The other end of the first member and the other end of the second member form a contact area B2 other than the contact area A2, The contact surface area B1 and the contact surface area B2 are vibration-welded to manufacture a joined member. A manufacturing method for a joining member. 16. 10. The method for manufacturing a joint member according to 9 above, wherein the bending is performed at a force of 10 N or less per mm. [Effects of the Invention]

[0010] According to the joining member of the present invention, since the bent member contains reinforcing fibers and a thermoplastic resin, the bending process can be easily performed. Preferably, the reinforcing fibers and the thermoplastic resin are joined by welding, which eliminates the need for an adhesive, thereby reducing the weight of the joining member. Furthermore, since no adhesive is required, the joining member has excellent recyclability. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a schematic diagram showing an example of a joining member of the present invention. [Figure 2] 1 is a schematic diagram showing an example of a joining member of the present invention. [Figure 3] (a) Schematic diagram of welding two locations from the first member side using ultrasonic waves. (b) Schematic diagram of welding one location each from the first member side and the second member side using ultrasonic waves. [Figure 4] Schematic diagram of welding using infrared heating. [Figure 5] (a) A schematic diagram showing a state in which a bending process is performed using a jig. (b) A schematic diagram showing a state in which a wedge provided on the jig is used to push the thermoplastic resin contained in the first member precursor into the second member precursor sandwiched by the bending process. [Figure 6](A) is a perspective view showing a schematic configuration when the joining member of the present invention is mounted as a shock absorbing member on an automobile to form a shock absorbing structure 600. (B) is a schematic cross-sectional view when the joining member of the present invention is mounted as a shock absorbing member on an automobile to form a shock absorbing structure 600. [Figure 7] 1 is a schematic view showing an example of a joining member of the present invention. [Figure 8] (a) Schematic diagram showing the state of a non-ultrasonic welded bonded member after bending when subjected to a tensile fracture test (Example 2). (b) Schematic diagram showing the state of a non-ultrasonic welded bonded member after bending when subjected to a tensile fracture test (Example 1). [Figure 9] Schematic diagram showing what happens during a side collision. [Figure 10] 1 is a bonded member produced in Example 1. DETAILED DESCRIPTION OF THE INVENTION

[0012] [Connection material] The joining member of the present invention is a joining member formed by combining a first member and a second member, the first member including reinforcing fibers and a thermoplastic resin, and the first member and the second member forming a closed cross-sectional shape in a cross section perpendicular to the longitudinal direction of the joining member. The shape of the closed cross-section is not particularly limited, and may be, for example, an ellipse, a rectangle, or a polygon such as a hexagon (e.g., FIGS. 1 and 2), or the cross-sectional shape may be a combination of a circle and a polygon. A hat-shaped joining member with a flange, as exemplified in FIGS. 1 and 2, may also be combined. The joining member is preferably a shock absorbing member.

[0013] [Outline of joints made by bending] 1. Joining materials In the joining member of the present invention, the first member has one end and the other end in a width direction perpendicular to the longitudinal direction, and the second member has one end and the other end in a width direction perpendicular to the longitudinal direction, a first bent portion at one end of the first member or one end of the second member; The other end of the first member or the other end of the second member has a second bent portion.

[0014] 2. Manufacturing method When manufacturing a joining member, a first member precursor for forming the first member and a second member precursor for forming the second member are prepared; the first member precursor has one end and the other end in a width direction perpendicular to the longitudinal direction, the second member precursor has one end and the other end in a width direction perpendicular to the longitudinal direction, heating and bending one end of the first member precursor or one end of the second member precursor to form a first bent portion; The other end of the first member precursor or the other end of the second member precursor may be heated and bent to form a second bent portion. Although there are no particular limitations on the method of bending, the first and second members preferably contain a thermoplastic resin and reinforcing fibers, and the thermoplastic resin is softened and deformed by heating the areas where bending is desired. There are no particular limitations on the heating means, and an infrared heating device, for example, can be used. When heating, it is sufficient to locally heat only the areas to be bent, and areas not required for bending can be masked to prevent heating. When using a second member that is not to be bent, the second member (e.g., 102 in Figure 1) may be metal and may contain the same thermoplastic resin and reinforcing fibers as the first member. Bending can be performed at a force of 10 N or less per mm, and can also be performed at a force of 7 N or less per mm.

[0015] [Reinforced fiber] The reinforcing fibers contained in the first member or the second member in the present invention will be described below. 1. Fiber length The weight average fiber length of the reinforcing fibers is preferably 1 mm or more and 100 mm or less, more preferably 3 mm or more and 80 mm or less, and even more preferably 5 mm or more and 60 mm or less. In other words, the reinforcing fibers are preferably discontinuous fibers.

[0016] If the weight-average fiber length Lw of the reinforcing fibers is 100 mm or less, the flowability of the composite material is not likely to decrease when the first member and / or the second member are produced by press molding, and it is easy to produce them in the desired shape. Furthermore, if the weight-average fiber length Lw is 1 mm or more, the mechanical strength of the resulting first member and / or the second member is not likely to decrease, which is preferable.

[0017] When discontinuous fibers are used as reinforcing fibers, formability is improved compared to when only continuous fibers are used, making it easier to create complex fiber-reinforced resin moldings. Furthermore, by using discontinuous reinforcing fibers, even if stress is applied from any direction to the first member and / or second member, it is unlikely that a direction in which the mechanical properties will be extremely weakened will occur.

[0018] In a molded body produced by injection molding, the weight average fiber length of the reinforcing fibers is about 0.1 to 0.3 mm. Therefore, when the weight average fiber length of the reinforcing fibers is set to 1 mm or more and 100 mm or less, it is preferable to produce the first member and the second member by press molding.

[0019] In the present invention, discontinuous reinforcing fibers having different fiber lengths may be used in combination. In other words, the discontinuous reinforcing fibers used in the present invention may have a single peak in the weight-average fiber length distribution, or may have multiple peaks.

[0020] 2. Number-average fiber length Ln and weight-average fiber length Lw of reinforcing fibers Generally, if the fiber length of each reinforcing fiber is Li, the number average fiber length Ln and weight average fiber length Lw can be calculated by the following formulas (1) and (2). The units of the number average fiber length Ln and weight average fiber length Lw are mm. Ln=ΣLi / I equation (1) Lw=(ΣLi 2 ) / (ΣLi)...Equation (2) Here, "I" indicates the number of reinforcing fibers measured.

[0021] When the fiber length is constant, the number-average fiber length and the weight-average fiber length are the same value. A sample is taken from the first member or the second member, and the reinforcing fibers can be extracted from it by, for example, subjecting it to a heat treatment at 600°C for about 1 hour and removing the resin in a furnace.

[0022] The average fiber length can be calculated, for example, by measuring the fiber lengths of 100 fibers randomly extracted from the first member or the second member to the nearest 1 mm using a caliper or the like, and then calculating the average fiber length based on formula (1).

[0023] If the dispersion contains short fibers that cannot be measured with a caliper, remove the resin, then place the resulting reinforcing fibers in water containing a surfactant and thoroughly stir using ultrasonic vibrations. Samples for evaluation can be obtained by randomly sampling the stirred dispersion with a measuring spoon, and measuring the lengths of 3,000 fibers using a Nireco Luzex AP image analyzer. The measured fiber lengths can be used to calculate the number-average fiber length Ln and weight-average fiber length Lw using the same formulas (1) and (2) described above.

[0024] 3. Volume ratio of reinforcing fibers There is no particular limitation on the fiber volume fraction Vf of the reinforcing fibers of the first or second member, but it is preferably 20 to 70%, more preferably 25 to 60%, and even more preferably 30 to 55%. The fiber volume fraction (Vf, unit: volume %) is the ratio of the volume of the reinforcing fibers to the total volume including not only the reinforcing fibers and resin but also other additives. There is no limitation on the analysis of the reinforcing fiber volume fraction, but it is recommended to measure it as follows.

[0025] A sample is cut from the first or second member, and the resin is burned off in a furnace at 600°C for 1 hour. The mass of the sample is weighed before and after treatment to calculate the mass of the reinforcing fiber, resin, and other additives. Next, the volume ratio of the reinforcing fiber to the resin is calculated using the specific gravity of each component. Vf = 100 x reinforcing fiber volume / (reinforcing fiber volume + resin volume + other additive volume)

[0026] 4. Types of reinforcing fibers In this specification, the reinforcing fiber is preferably at least one selected from the group consisting of carbon fiber, aramid fiber, glass fiber, polyester fiber, nylon fiber, polypropylene fiber, and polyethylene fiber, and more preferably carbon fiber or glass fiber. 4.1 Reinforcement fiber: carbon fiber 4.1.1. Carbon fiber in general When carbon fibers are used, polyacrylonitrile (PAN)-based carbon fibers, petroleum / coal pitch-based carbon fibers, rayon-based carbon fibers, cellulose-based carbon fibers, lignin-based carbon fibers, phenol-based carbon fibers, etc. are generally known, and any of these carbon fibers can be suitably used in the present invention. Among these, polyacrylonitrile (PAN)-based carbon fibers are preferred in the present invention because of their excellent tensile strength. As a PAN-based carbon fiber, for example, TENAX (registered trademark) STS40-24KS (average fiber diameter 7 μm) carbon fiber manufactured by Teijin Limited can be used. 4.1.2. Carbon fiber sizing agent The carbon fiber used in the present invention may have a sizing agent attached to its surface. When using carbon fiber with a sizing agent attached, the type of sizing agent can be appropriately selected depending on the type of carbon fiber and the type of resin used in the X material or Y material, and is not particularly limited.

[0027] 4.2 Reinforcement fiber: glass fiber The case where the reinforcing fiber used in the present invention is glass fiber will be described. 4.2.1.Glass fiber in general The glass fiber used in the present invention may be any glass fiber generally referred to as glass fiber. The glass composition is not particularly limited, and may include A-glass, C-glass, E-glass, etc., and may contain components such as TiO2, SO3, and P2O5 in some cases. For example, Nitto Boseki's E-glass RS240QR-483 (count: 2400 g / 1000 m) glass fiber can be used as the glass fiber. 4.2.2.Glass fiber sizing agents The glass fiber used in the present invention may have a sizing agent attached to its surface. When using glass fiber with a sizing agent attached, the type of sizing agent can be appropriately selected depending on the type of glass fiber and the type of resin, and is not particularly limited. Glass fiber that has been pre-treated with a conventionally known coupling agent such as an organosilane compound, an organotitanium compound, an organoborane compound, or an epoxy compound can be preferably used.

[0028] Fiber Orientation 1. Random distribution The state of the reinforcing fibers contained in the first member or the second member is not particularly limited, and may be, for example, arranged in one direction or randomly. From the viewpoint of uniformity of the shape rigidity and strength of the first member or the second member, it is preferable that the reinforcing fibers be in a two-dimensional random dispersion state in which the long axis directions of the reinforcing fibers are randomly dispersed in the in-plane direction of the first member or the second member. 2. Fiber orientation measurement method The degree of orientation of two-dimensionally randomly dispersed reinforcing fibers is evaluated by calculating the ratio of the tensile modulus in two mutually perpendicular directions. The reinforcing fibers can be evaluated as being two-dimensionally randomly dispersed if the (Eδ) ratio, calculated by dividing the larger of the tensile modulus values ​​measured in any direction of the first or second member by the smaller of the measured values ​​in the direction perpendicular to that direction, is 5 or less, more preferably 2 or less, and even more preferably 1.5 or less. Since the joining member that joins the first or second member is cylindrical and may include curved surfaces in some cases, a method for evaluating two-dimensional random dispersion in the in-plane direction can be to make an incision in the joining member, separate the first and second members, and then heat it above the softening temperature to return it to a flat plate shape and solidify it. Then, test specimens can be cut out and the tensile modulus measured to confirm the state of random dispersion in the two-dimensional direction.

[0029] [resin] The thermoplastic resin contained in the first member or the second member in the present invention will be described below. The type of thermoplastic resin is not particularly limited, and any resin having a desired softening point or melting point can be appropriately selected and used. As the thermoplastic resin, one having a softening point in the range of 180°C to 350°C is usually used, but is not limited thereto.

[0030] Examples of thermoplastic resins include polyolefin resins, polystyrene resins, polyamide resins, polyester resins, polyacetal resins (polyoxymethylene resins), polycarbonate resins, (meth)acrylic resins, polyarylate resins, polyphenylene ether resins, polyimide resins, polyethernitrile resins, phenoxy resins, polyphenylene sulfide resins, polysulfone resins, polyketone resins, polyether ketone resins, thermoplastic urethane resins, fluorine-based resins, and thermoplastic polybenzimidazole resins.

[0031] The thermoplastic resin contained in the first member or the second member of the present invention may be one type only, or two or more types. Examples of a mode in which two or more types of thermoplastic resins are used in combination include, but are not limited to, a mode in which thermoplastic resins having different softening points or melting points are used in combination, or a mode in which thermoplastic resins having different average molecular weights are used in combination.

[0032] When a thermoplastic resin is used, it is more preferable to use a polyamide resin, and even more preferable to use a polyamide 6 resin.

[0033] The thermoplastic resin may contain additives such as various fibrous or non-fibrous fillers such as organic or inorganic fibers, flame retardants, UV-resistant agents, stabilizers, release agents, pigments, softeners, plasticizers, surfactants, etc. The additives may be used alone or in combination of two or more.

[0034] [Welding] 1. Contact area 1.1 Welding of contact areas A1 and A2 The contact surface between one end of the first member and one end of the second member forms a contact surface area A1 formed by folding and a contact surface area B1 other than A1, The contact surface between the other end of the first member and the other end of the second member forms a contact area A2 formed by folding and a contact area B2 other than A2, Preferably, the contact area A1 and / or the contact area A2 is a joint, and more preferably, the contact area A1 and / or the contact area A2 is a welded portion. The surface contact area A1 and the surface contact area A2 are surface contact areas between the first member and the second member that only occur when the first member and the second member are folded and overlapped after bending. The surface contact area A1 and the surface contact area A2 do not exist when the folding process is not performed. For example, the surface contact area A1 and the surface contact area A2 do not exist when the hat-shaped first member precursor and the second member precursor are simply overlapped before bending. On the other hand, the surface contact area B1 and the surface contact area B2 are surface contact areas that occur regardless of the bending process. Therefore, for example, the surface contact area B1 and the surface contact area B2 exist even when the hat-shaped first member precursor and the second member precursor are overlapped before bending. 1.2 Welding of contact areas B1 and B2 One end of the first member and one end of the second member form a contact area A1 formed by folding and a contact area B1 other than A1, The other end of the first member and the other end of the second member form a contact area A2 formed by folding and a contact area B2 other than A2, It is preferable that the contact surface area B1 and / or the contact surface area B2 be the welded portion.

[0035] 2.Ultrasonic welding From the viewpoint of energy efficiency for melting the thermoplastic resin contained in the first or second member, a method of applying vibration energy is preferred, vibration welding is more preferred, and ultrasonic welding is even more preferred. Ultrasonic welding has fewer limitations on the shape and size of the first and second members, allowing for the use of first and second members of any shape, making it possible to manufacture joining members for a wide range of applications. Ultrasonic welding allows for efficient welding due to its small heat-affected zone.

[0036] Ultrasonic welding is a method of welding a first and a second component by pressing a resonator called a welding horn (303 in Figures 3(a) and 3(b)) against the first component and applying high-frequency mechanical vibrations from the resonator. The mechanical vibrations transmitted to the first component are converted into frictional heat, melting at least a portion of the components to be joined. This method can be performed using an ultrasonic welding machine (Branson, product name: 2000Xdt), for example. Control factors for ultrasonic welding include the ultrasonic frequency, ultrasonic amplitude, ultrasonic application time, and pressure applied to the sample. The higher the ultrasonic amplitude, ultrasonic application time, and pressure applied to the sample, the higher the bond strength. However, these can be appropriately controlled to achieve stable welding, taking into account factors such as the equipment specifications, the thickness of the sheet portions of the components to be joined, the shape and dimensions of the protrusions, and the desired cycle time. Control conditions for ultrasonic welding include frequency, welding time, amplitude, and pressure, and preferred conditions are a frequency of 15 to 50 kHz, a welding time of 0.1 to 5 seconds, an amplitude of 30 to 100 μm, and a pressure of 600 to 2000 N. From the perspective of welding productivity, more preferred ranges are a frequency of 20 to 40 kHz, a welding time of 0.5 to 2 seconds, and a pressure of 600 to 1600 N. Furthermore, when fixing the positions of the workpieces to be joined and fixing the welding position during ultrasonic welding, a jig called an anvil may be used.

[0037] Preferably, any one of the contact areas A1, A2, B1, and B2 is welded by ultrasonic welding. More preferably, the contact area A1 and / or the contact area A2 is welded by ultrasonic welding.

[0038] 3. Welding by infrared heating (IR heating) In the present invention, the first and second members may be welded using infrared heating (IR heating). Infrared welding is a technique in which two resin parts are radiantly heated by an infrared heater and pressed together in a stationary state without contacting the parts. Because most of the infrared radiated energy reaches the heated part, is absorbed, and heats it, the use of an infrared heater is highly efficient. Welding by infrared heating allows for a non-contact process without applying vibration. For example, FIG. 4 is a schematic diagram showing one end and the other end of the first member being bent using a jig 401. By heating one end of the first member and the other end of the first member during the bending process using an infrared heating device 402, the first hemmed portion and the second hemmed portion can be welded to the second member, and the second hemmed portion and the second member can be welded to the second member, respectively, almost simultaneously after the bending process is completed.

[0039] It is preferable that any one of the contact areas A1, A2, B1, and B2 is welded by infrared heating. It is preferable that the contact area A1 and / or the contact area A2 is welded by infrared heating. In addition, since infrared heating involves radiating light from an infrared heating rod, in order to partially heat the first member and / or the second member, it is preferable to mask areas other than the heated areas.

[0040] The type of infrared radiation source emitted by the infrared radiation mechanism is not particularly limited, but examples include lasers, halogen heaters, carbon heaters, ceramic heaters, etc. The infrared radiation emitted from each heater has a different infrared wavelength range. Infrared radiation is often classified into far infrared radiation, mid infrared radiation, near infrared radiation, etc., depending on its wavelength.

[0041] 4. Joining by inserting resin When one end of the first member precursor or one end of the second member precursor is heated and folded, the one end of the first member and the one end of the second member form a contact area A1 by folding, When the other end of the first member precursor or the other end of the second member precursor is heated and folded, the other end of the first member and the other end of the second member form a contact area A2 by folding over, and it is preferable that the thermoplastic resin contained in the heated and folded first member precursor or second member precursor is inserted into and welded to the second member precursor or first member precursor sandwiched between them by the folding process in the contact area A1 and / or the contact area A2.

[0042] 4.1 Wedge Joint When bending by heating to form the first bent portion or the second bent portion, a wedge may be provided in the bending jig to allow the thermoplastic resin contained in the first member precursor or the second member precursor to be inserted into the first member precursor or the second member precursor sandwiched by the bending process, thereby manufacturing a joining member.

[0043] 5 shows an example of a joining method using a wedge. Jig 501 has wedge 502. Simultaneously with the completion of the bending process, resin is poured from the outside of the first bent portion or the second bent portion toward the member that will be sandwiched by the bending process.

[0044] 4.2 Insert the protrusion into the hole and weld A hole may be formed in the first member precursor and / or the second member precursor that are to be sandwiched by the bending processing portion, and a convex portion may be formed in the portion of the first member precursor that is to be bent and / or the portion of the second member precursor that is to be bent, and the convex portion may be inserted into the hole and welded.

[0045] 5. Vibration welding A first member precursor for forming a first member and a second member precursor for forming a second member are prepared, and when one end of the first member precursor or one end of the second member precursor is heated and folded, the one end of the first member and one end of the second member form a surface contact area A1 by folding, and the one end of the first member and one end of the second member form a surface contact area B1 other than the surface contact area A1 by folding. When the other end of the first member precursor or the other end of the second member precursor is heated and folded, the other end of the first member and the other end of the second member form a surface contact area A2 by folding, and the other end of the first member and the other end of the second member form a surface contact area B2 other than the surface contact area A2.

[0046] Preferably, the contact area B1 and / or the contact area B2 are welded by vibration welding, and more preferably, the contact area B1 and the contact area B2 are welded by vibration welding to produce a joined member.

[0047] Furthermore, it is preferable to vibration weld the contact area B1 and / or the contact area B2 before bending, because (i) before bending, it is easy to vibrate the first member and the second member relative to each other, and (ii) by performing bending after vibration welding, it is possible to prevent misalignment of the joining positions when welding the contact areas A1 and A2.

[0048] Specific examples of the region to be vibration welded are shown as the hatched regions 304 in Fig. 3, 403 in Fig. 4, and 503 in Fig. 5. These are also examples of the surface contact region B1 and the surface contact region B2.

[0049] 6.Other Joints In addition to the above-mentioned joining methods, the first member and the second member may be joined by another joining method. There are no particular limitations on the additional joining method, and examples include fastening with bolts and nuts, joining with clips and clamps, joining with rings and pins, press-fit joining, and rivet joining. However, from the viewpoints of recyclability and weight reduction, it is preferable not to use adhesives in the joining of the present invention. Rivets made of the same material are recyclable.

[0050] [Integrated molding] The first member and / or the second member is a fiber reinforced resin molded body containing reinforcing fibers and a thermoplastic resin, and the fiber reinforced resin molded body is preferably an integrally molded body. Integral molding means that these are molded continuously without any seams, and are not formed by joining separate components together. This type of integral molding creates a structure in a single molding operation, preferably achieved by press molding. Because it is created by integral molding, separate parts can be processed as a single part, making it possible to reduce the unit price of the part. In addition, the number of assembly steps is reduced, and the reduction in the number of parts also makes it possible to reduce inventory costs.

[0051] [Method of manufacturing the first member and / or the second member: molding die] The first member and the second member are preferably integrally molded bodies produced by press-molding a composite material containing reinforcing fibers and a thermoplastic resin using a first mold and a second mold. Hereinafter, the first mold is a lower mold (sometimes referred to as a lower molding mold), the second mold is an upper mold (sometimes referred to as an upper molding mold), and the second mold opens and closes by moving up and down toward the first mold. However, for example, the first mold may open and close by moving up and down toward the second mold. Alternatively, the first mold and the second mold may be opened and closed by moving at least one of them horizontally.

[0052] [Method of manufacturing the first member and / or the second member: Press molding] 1. Hot press molding and cold press molding When producing the first member and / or the second member of the present invention, a composite material containing reinforcing fibers and a thermoplastic resin can be produced by press molding (sometimes called compression molding), and molding methods such as hot press molding and cold press molding can be used as the press molding. By press molding the composite material, various shapes can be imparted to the first member and / or the second member. The first member and / or the second member manufactured by press molding is preferably an integrally molded body.

[0053] 2.Cold press molding The first or second member of the present invention is preferably formed by cold-pressing a composite material containing a thermoplastic resin and reinforcing fibers. In cold-press molding, for example, a composite material heated to a first predetermined temperature is placed in a mold set to a second predetermined temperature, and then pressurized and cooled.

[0054] Specifically, if the thermoplastic resin contained in the composite material is crystalline, the first predetermined temperature is equal to or higher than the melting point, and the second predetermined temperature is lower than the melting point. If the thermoplastic resin is amorphous, the first predetermined temperature is equal to or higher than the glass transition temperature, and the second predetermined temperature is lower than the glass transition temperature. That is, the cold pressing method includes at least the following steps A-1) to A-2). Step A-1) A step of heating the thermoplastic resin to a temperature above the melting point but below the decomposition temperature if the thermoplastic resin is crystalline, or above the glass transition temperature but below the decomposition temperature if the thermoplastic resin is amorphous. Step A-2) The composite material heated in step A-1) is placed in a mold whose temperature is adjusted to below the melting point if the thermoplastic resin is crystalline, or below the glass transition temperature if the thermoplastic resin is amorphous, and then pressurized. By performing these steps, the molding of the composite material can be completed (the first member and / or the second member, which are press-molded bodies, can be produced).

[0055] The above steps must be performed in the order described above, but other steps may be included between each step, such as a shaping step, which is performed before step A-2), in which a shaping mold different from the mold used in step A-2) is used to pre-shape the mixture into the shape of the cavity of the mold.

[0056] The shape of the composite material may be a shape developed by computer through inverse molding analysis from the three-dimensional shape of the press-molded product to be manufactured.

[0057] 3.Hot press molding In the hot press molding method, for example, a composite material is placed in a mold, pressure is applied while the temperature of the mold is raised to a first predetermined temperature, and the mold is cooled to a second predetermined temperature. Specifically, if the thermoplastic resin constituting the composite material is crystalline, the first predetermined temperature is equal to or higher than the melting point, and the second predetermined temperature is lower than the melting point. If the thermoplastic resin contained in the composite material is amorphous, the first predetermined temperature is equal to or higher than the glass transition temperature, and the second predetermined temperature is lower than the glass transition temperature. Hot press molding preferably includes at least the following steps B-1) to B-4). B-1) A process of placing the composite material in the mold (second mold, lower mold). B-2) A process of applying pressure while heating the mold to a temperature above the melting point and below the thermal decomposition temperature of the thermoplastic resin if the thermoplastic resin is crystalline, or to a temperature above the glass transition temperature and below the thermal decomposition temperature of the thermoplastic resin if the thermoplastic resin is amorphous (first pressing process). B-3) A process of applying pressure in one or more stages, with the pressure in the final stage being 1.2 to 100 times the pressure in the first pressing process (second pressing process). B-4) A step of adjusting the mold temperature to below the melting point if the thermoplastic resin is crystalline, or below the glass transition temperature if the thermoplastic resin is amorphous. By carrying out these steps, an integrally molded structure can be produced.

[0058] 4. Commonalities between cold press molding and hot press molding Steps A-2) and B-3) are steps in which pressure is applied to the composite material to obtain a fiber-reinforced resin molded product of the desired shape. The molding pressure is not particularly limited, but is preferably as low as possible within a range that allows the desired shape of the first and / or second member to be obtained. Specifically, the pressure is preferably less than 30 MPa relative to the mold cavity projected area, more preferably 20 MPa or less, and even more preferably 10 MPa or less. A molding pressure of less than 30 MPa is preferable because it does not require capital investment or maintenance costs for a press. Naturally, various processes may be inserted between the above steps during compression molding; for example, vacuum compression molding, in which compression molding is performed under vacuum, may be used.

[0059] [First embodiment] 1. Overview 1, the joint member 100 of this embodiment extends in the longitudinal direction. The longitudinal direction is the direction from front to back on the paper (Y direction). The joint member 100 has a closed cross-sectional shape in a cross section perpendicular to the longitudinal direction (Y direction) by joining a first member 101 and a second member 102, each of which has a hat-shaped cross section perpendicular to the longitudinal direction (Y direction).

[0060] 2. First member In the first embodiment, the first member 101 includes reinforcing fibers and a thermoplastic resin. The first member 101 is formed by press-molding a flat plate so that the cross section perpendicular to the longitudinal direction (Y direction) has a hat shape. More specifically, a recess 105 is provided in the center in the width direction (X direction). The first member 101 has a first bent portion 103 and a second bent portion 104, which are formed by bending one end and the other end in the width direction perpendicular to the longitudinal direction.

[0061] The relationship between the radius of curvature of the first bent portion 103 and the second bent portion 104 and the plate thickness of the first member is preferably 1.5 < radius of curvature ÷ plate thickness < 2 when the plate thickness is less than 3 mm. Compared to steel plate, the first member containing reinforcing fibers and thermoplastic resin has excellent bending workability, so even if the radius of curvature during bending is increased, cracks do not easily occur. The plate thickness is preferably 1.0 mm or more and 5.0 mm or less, more preferably 1.5 mm or more and 3.5 mm, and even more preferably 2.0 mm or more and 3.0 mm. From the viewpoint of improving bending rigidity, a larger thickness is preferable. The radius of curvature is preferably 3.0 mm or more and 6.0 mm or less, and more preferably 3.5 mm or more and 5.5 mm or less.

[0062] 3. Second member In the first embodiment, the second member 102 also includes reinforcing fibers and a thermoplastic resin. The second member 102 may be made of the same material as the first member 101, or may be made of a different material. For example, the first member may be made of carbon fibers and a polyamide resin, and the second member may be made of glass fibers and a polypropylene resin. Conversely, the first member and the second member may be made of the same material.

[0063] The second member 102 is formed by press-molding a flat plate so that the cross section perpendicular to the longitudinal direction (Y direction) has a hat shape. More specifically, a recess 107 is provided in the center in the width direction (X direction), and flanges 106 are provided at both ends in the width direction (X direction) that are continuous with the recess 107 and extend outward in the width direction (X direction).

[0064] In the case of a joining member such as that shown in Figure 1, if the same molding die is used in the area excluding the bent portion when manufacturing the first and second members, both members will have the same shape except for the bent portion. If they have the same shape, the molding die can be shared.

[0065] 4. Bonding condition When the first member 101 and the second member 102 are joined together, one end of the first member 101 and the other end of the first member 102 are bent to form a first bent portion 103 and a second bent portion 104, respectively, and one end (flange portion) 106 of the second member is sandwiched between the first bent portion 103 and the other end (flange portion) 106 of the second member is sandwiched between the second bent portion 104.

[0066] In other words, when the first member 101 and the second member 102 are joined together, the flange portion 106 of the second member 102 is sandwiched between the first bent portion 103 and the second flanged portion 104 of the first member 101. In plan view, the flange portion 106 is sandwiched between the first bent portion 103 and the second bent portion 104. In other words, substantially the entire surface of the flange portion 106 is sandwiched between the first bent portion or the second bent portion.

[0067] Therefore, in the first embodiment, the entire surface of the flange portion 106 is joined to the first bent portion or the second bent portion by welding. However, when considering other embodiments, it is not necessarily the case that the entire surface of the flange portion 106 is sandwiched between the first bent portion or the second bent portion.

[0068] 4.1 Ultrasonic welding of the first and second members When one end of the first member precursor is heated and folded, the one end of the first member and the one end of the second member form a contact area A1 by folding; When the other end of the first member precursor is heated and folded, the other end of the first member and the other end of the second member form a contact area A2 by folding, Preferably, the surface-facing area A1 and / or the surface-facing area A2 are welded by applying ultrasonic waves.

[0069] An example of the manufacturing method of the bonded member of the present invention using ultrasonic welding will be described with reference to FIG. 3(a). As shown in FIG. 3(a), a folded portion 103 at one end of a first member 101 is aligned with the surface of a flange portion of a second member, and ultrasonic waves are applied to one end of the first member toward the surface-contact area A1 formed by folding. This melts the thermoplastic resin contained in the first member, thereby securing the first and second members together. Similarly, a folded portion 104 at the other end of the first member 101 is aligned with the surface of a flange portion of a second member, and ultrasonic waves are applied to the other end of the first member toward the surface-contact area A1 formed by folding. This melts the thermoplastic resin contained in the first member, thereby securing the first and second members together. After applying ultrasonic waves to melt the thermoplastic resin, a cooling process can be performed as needed. The first and second members can also be temporarily fastened using known means (e.g., clips) before ultrasonic welding. In FIG. 3(a), ultrasonic waves are applied from the folded region side on the lower side of the paper, but they may be applied from the opposite side of the folded region.

[0070] 4.2 Energy Director It is preferable to provide an energy director on the first member precursor and / or second member precursor that form the contact area A1 and / or the contact area A2, and apply the ultrasonic waves so as to melt the energy director. The energy director is, for example, a protrusion such as that shown in 302 in FIG. 3(a). Because the energy director is provided on the first member precursor or the second member precursor, the vibrations of the ultrasonic waves are concentrated, allowing for favorable welding. The energy director begins to vibrate due to the ultrasonic waves, and melts and welds first at the locations where stress is concentrated.

[0071] 5. Impact absorbing materials and structures The joining member of the present invention is preferably a shock absorbing member, and the shock absorbing member is preferably mounted on an automobile as a shock absorbing structural member.

[0072] The shock absorbing structure is preferably for absorbing impact energy input to a bumper of an automobile. Hereinafter, a shock absorbing structure for absorbing impact energy input to a bumper of an automobile will be described.

[0073] Fig. 6(A) is a perspective view that schematically shows the general configuration of a shock absorbing structure 600 according to one embodiment of the present invention. Fig. 6(B) is a schematic cross-sectional view of the shock absorbing structure 600. The shock absorbing structure includes joining members 602L and 602R and a tip member 601. The joining members 602L and 602R are cylindrical shock absorbing members.

[0074] In the following description, the three orthogonal directions in the shock absorption structure 600 will be referred to in descending order of length as the left-right direction, the front-rear direction, and the up-down direction. For convenience, the following description will define the front, rear, left, right, up, and down directions, with the front indicated as Fr, the rear as Rr, the left as L, the right as R, the up as U, and the down as D. The Fr-Rr direction in FIG. 6 corresponds to the Y direction in FIGS. The UD direction in FIG. 6 corresponds to the Z direction in FIGS. The LR direction in FIG. 6 corresponds to the X direction in FIGS.

[0075] 6. Shape of shock absorbing members 602L and 602R 6.1 Cylindrical The shock absorbing members (joint members) 602L, 602R are cylindrical, as shown by 100 and 200 in FIGS. 1 and 2, and have an internal cavity. The Y-axis direction in FIG. 7 indicates the shock absorbing direction (axial direction of the outer cylinder) of the joint members (shock absorbing members) 602L, 602R. A cross section cut perpendicular to the shock absorbing direction (Fr-Rr direction) preferably has a closed cross-sectional shape. The cross-sectional shape is not particularly limited and may be circular, elliptical, polygonal, or another shape, or may be a combination of circular, elliptical, and polygonal shapes. The cross-sectional area does not need to be constant; it may increase from the end on the shock input side to the opposite end, or it may increase from the end on the shock input side to the opposite end and then decrease again.

[0076] 6.2 Impact input end and opposite end The shock absorbing members 602L and 602R have shock input ends, which are ends of the shock absorbing members 602L and 602R that are first subjected to a shock, and which are ends in the Y direction in FIG. On the other hand, the opposite end is the end of the impact absorbing members 602L, 602R opposite the impact input end, for example, the end opposite the impact input end in the Y direction in FIG.

[0077] 6.3 Hollow structure The joining members (shock absorbing members) 602L and 602R preferably have a hollow structure consisting of an outer cylindrical portion and a hollow portion. The hollow portion refers to the space inside the outer cylindrical portion. The outer cylindrical portion may have protrusions or ribs. Figure 7 shows an example of an outer cylindrical portion 701 and a hollow portion 702.

[0078] 6.4 Openings The end face at one end of the cylindrical shock absorbing members 602L, 602R is preferably an opening face with at least a portion open. The opening face is, for example, the entrance face of a hollow portion exemplified by 702 in Fig. 7. The shock absorbing members 602L, 602R preferably have a hollow structure consisting of an outer cylindrical portion and a hollow portion, and the opening face serves as an entrance / exit for accessing the hollow portion.

[0079] 7. Shock absorbing structure The tip member 601 is preferably a front bumper or a rear bumper of an automobile, and the joining members (shock absorbing members) 602L, 602R are preferably joined to the front bumper or the rear bumper of an automobile.

[0080] The base end members 603L, 603R joined to the joining members (shock absorbing members) 602L, 602R may be vehicle frame members. That is, the joining members (shock absorbing members) 602L, 602R may be joined directly to the vehicle frame members, and in this case, the base end members 603L, 603R, which are vehicle frame members, may be side members of an automobile.

[0081] In another embodiment, the shock absorbing structure is mounted on a vehicle, the tip member 601 is arranged between the exterior body of the vehicle frame and the vehicle frame, and the base members 603L, 603R are arranged between the joining members (shock absorbing members) 602L, 602R and the vehicle frame.

[0082] The front-rear direction of the shock absorbing structure coincides with the length direction of the vehicle, the left-right direction of the shock absorbing structure coincides with the width direction of the vehicle, and the up-down direction of the shock absorbing structure coincides with the height direction of the vehicle.

[0083] The shock absorbing structure preferably includes a joining member (shock absorbing member) 602R and a joining member (shock absorbing member) 602L arranged spaced apart in the left-right direction (FIG. 6). The joining member (shock absorbing member) 602R and the joining member (shock absorbing member) 602L are members that absorb impact energy input to a tip member 601 (described below) by deforming. The joining member (shock absorbing member) 602R and the joining member (shock absorbing member) 602L preferably have the same structure, and are arranged symmetrically with respect to a line of symmetry that extends in the front-rear direction and is set at the center position of the shock absorbing structure in the left-right direction.

[0084] The joining member (shock absorbing member) 602R and the joining member (shock absorbing member) 602L are each a cylindrical structure with its axial direction aligned in the front-to-rear direction ( FIG. 6(A) ). The joining member (shock absorbing member) 602R and the joining member (shock absorbing member) 602L each contain reinforced fibers and a thermoplastic resin. For example, various shapes and materials such as those described in U.S. Patent Application Publication No. 20160356334 or WO 2020 / 129227 can be used. When the joining member (shock absorbing member) 602R and the joining member (shock absorbing member) 602L are each made of a composite material, the tensile elongation of each of the shock absorbing members 602R and 602L is preferably less than 5%.

[0085] The shock absorbing structure preferably further includes a plate-shaped base end member 603R joined to the rear end surface of the joining member (shock absorbing member) 602R, and a plate-shaped base end member 603L joined to the rear end surface of the joining member (shock absorbing member) 602L. The base end members 603R and 603L are arranged such that their thickness directions coincide with the front-rear direction. The base end members 603R and 603L may each be made of a metal such as aluminum, but are not limited to this.

[0086] The shock absorbing structure may further include a cylindrical tip member 601 that extends in the left-right direction while curving forward from near the front end of joining member (shock absorbing member) 602R to near the front end of joining member (shock absorbing member) 602L. Tip member 601 (see, for example, FIG. 6) is preferably a bumper reinforcement and is made of a metal such as aluminum, but is not limited to this. Tip member 601 has a shape that is symmetrical with respect to a line of symmetry that extends in the front-rear direction and is set at the center position of the shock absorbing structure in the left-right direction.

[0087] The tip member 601 (Fig. 6) preferably comprises a plate-shaped upper surface portion (601U in Fig. 6) whose thickness direction coincides with the vertical direction, a plate-shaped lower surface portion (601D) arranged below the upper surface portion (601U in Fig. 6) and whose thickness direction coincides with the vertical direction, a curved plate-shaped front surface portion (601Fr in Fig. 1) connecting the front end edge of the upper surface portion (601U in Fig. 6) and the front end edge of the lower surface portion (601D), and a curved plate-shaped rear surface portion (601Rr) connecting the portion of the rear end edge of the upper surface portion (601U in Fig. 1) excluding both end portions and the portion of the rear end edge of the lower surface portion (601D in Fig. 1) excluding both end portions.

[0088] 8. Uneven thickness structure The joining member is preferably a shock-absorbing member. In the first member and / or the second member, it is preferable that the first member and / or the second member be arranged in order of increasing compressive strength from the leading end side to the rear end side where the first member and / or the second member receive the shock. By making the thickness of the first member and / or the second member uneven so that it increases from the leading end side to the rear end side where the shock is received, it is possible to arrange the first member and / or the second member in order of increasing compressive strength from the leading end side to the rear end side.

[0089] By using such first and / or second members, the joining members (shock absorbing members) 602L, 602R are arranged in order of increasing compressive strength from one end to the other end. In other words, the joining members (shock absorbing members) 602L, 602R have an uneven thickness structure in which the thickness increases from one end to the other end.

[0090] In this case, since the fracture occurs sequentially from the impact input side, the entire shock absorbing part can be used to absorb the impact. If the thickness is constant, it is difficult to determine the starting point where the fracture will occur first when an impact is received. The thickness deviation structure may be such that the thickness deviation gradually increases toward the other end, or the thickness deviation structure may be achieved by gradually (discontinuously) increasing the thickness of the first or second member, which has a uniform thickness.

[0091] When the joining members (shock absorbing members) 602L, 602R of the present invention have thickness variations such that the thickness increases from the impact input side to the opposite side, it is preferable that the rate of increase in the thickness of the joining members be a positive value (however, it may include a portion where the rate of increase in thickness is 0). In other words, it is preferable that the thickness gradually increases from the impact input side of the joining members to the opposite side (however, it may include a portion where the thickness is constant), and it is more preferable that there is no portion where the thickness increases once and then becomes thinner.

[0092] [Second embodiment] 1. Overview 2, the joint member 200 of this embodiment extends in the longitudinal direction. The longitudinal direction is the direction from front to back on the paper surface (Y direction). The joint member 200 has a closed cross-sectional shape in a cross section perpendicular to the longitudinal direction (Y direction) by joining a first member 201 and a second member 202, each of which has a hat-shaped cross section perpendicular to the longitudinal direction (Y direction).

[0093] 2. First member The first member includes reinforcing fibers and a thermoplastic resin. The first member 201 is formed by press-molding a flat plate so that the cross section perpendicular to the longitudinal direction (Y direction) has a hat shape. More specifically, a recess 205 is provided in the center in the width direction (X direction). The first member 201 has a first bent portion 203 formed by bending one end portion in the width direction perpendicular to the longitudinal direction. Meanwhile, the first member 201 has a flange portion 206-1 that is continuous with the recess 205 and extends outward in the width direction (X direction) at the other end portion in the width direction perpendicular to the longitudinal direction.

[0094] The relationship between the radius of curvature of the first bending portion 203 and the plate thickness of the first member is preferably 1.5 < radius of curvature ÷ plate thickness < 2 when the plate thickness is less than 3 mm. Compared to steel plate, the first member containing reinforcing fibers and thermoplastic resin has excellent bending workability, so even if the radius of curvature during bending is increased, cracks do not easily occur. The plate thickness is preferably 1.0 mm or more and 5.0 mm or less, more preferably 1.5 mm or more and 3.5 mm, and even more preferably 2.0 mm or more and 3.0 mm. From the viewpoint of improving bending rigidity, a larger thickness is preferable. The radius of curvature is preferably 3.0 mm or more and 6.0 mm or less, and more preferably 3.5 mm or more and 5.5 mm or less.

[0095] 3. Second member The second member 202 also contains reinforcing fibers and a thermoplastic resin. The second member 202 may be made of the same material as the first member 201, or may be made of a different material. For example, the first member may be made of carbon fiber and polyamide resin, and the second member may be made of glass fiber and polypropylene resin. Conversely, the first member and the second member may be made of the same material.

[0096] The second member 202 is formed by press-molding a flat plate so that the cross section perpendicular to the longitudinal direction (Y direction) has a hat shape. More specifically, a recess 207 is provided in the center in the width direction (X direction). The second member 202 has a second bent portion 204 formed by bending the other end in the width direction perpendicular to the longitudinal direction. Meanwhile, a flange portion 206-2 is provided at one end in the width direction (X direction) that continues from the recess 207 and extends outward in the width direction (X direction). In addition, in the case of a joining member such as that shown in FIG. 2, the first member and the second member have the same shape, so the same molding die can be used to produce the two members.

[0097] 4. Bonding condition When the first member 101 and the second member 102 are joined together, one end of the first member and the other end of the second member are bent to form a first bent portion and a second bent portion, respectively, and one end of the second member is sandwiched between the first bent portion and the other end of the first member is sandwiched between the second bent portion.

[0098] In other words, when the first member 101 and the second member 102 are joined together, one end of the first member 101 and the other end of the first member 102 are bent to form a first bent portion 103 and a second bent portion 104, respectively, and one end (flange portion) 106 of the second member is sandwiched between the first bent portion 103, and the other end (flange portion) 106 of the second member is sandwiched between the second bent portion 104.

[0099] In other words, in a state in which the first member 102 and the second member 102 are joined together, the flange portion 206-2 of the second member 202 is sandwiched between the first bent portion 203 of the first member 201. Similarly, the flange portion 206-1 of the first member 201 is sandwiched between the second bent portion 204 of the second member 202. The flange portions 206-1 and 206-2 are sandwiched between the first bent portion 203 and the second bent portion 204 in a plan view. In other words, substantially the entire surfaces of the flange portions 206-1 and 206-2 are sandwiched between the first bent portion or the second bent portion.

[0100] Therefore, in the second embodiment, the entire surfaces of the flange portions 206-1 and 206-2 are joined to the first bent portion or the second bent portion by welding. However, when considering other embodiments, it is not necessarily required that the entire surfaces of the flange portions 206-1 and 206-2 are sandwiched between the first bent portion or the second bent portion.

[0101] 4.1 Ultrasonic welding of the first and second members When one end of the first member precursor is heated and folded, one end of the first member and one end of the second member form a contact area A1 by folding, and when the other end of the second member precursor is heated and folded, the other end of the first member and the other end of the second member form a contact area A2 by folding, and it is preferable that the contact area A1 and / or the contact area A2 are welded by applying ultrasonic waves.

[0102] An example of the manufacturing method of the bonded member of the present invention using ultrasonic welding is described with reference to FIG. 3(b). As shown in FIG. 3(b), a folded portion 203 at one end of a first member 201 is aligned with the surface of a flange portion of a second member, and ultrasonic waves are applied to one end of the first member toward the surface-contact area A1 formed by folding. This melts the thermoplastic resin contained in the first member, thereby securing the first and second members together. Similarly, a folded portion 204 at the other end of a second member 202 is aligned with the surface of a flange portion of the first member toward the surface-contact area A1 formed by folding. This melts the thermoplastic resin contained in the second member, thereby securing the first and second members together. After applying ultrasonic waves to melt the thermoplastic resin, a cooling process can be performed as needed. The first and second members can also be temporarily fastened together using known means (e.g., clips) before ultrasonic welding. Although ultrasonic waves are applied from the folded region side in FIG. 3(b), they may be applied from the opposite side to the folded region.

[0103] 4.2 Energy Director It is preferable to provide an energy director on the first member precursor and / or second member precursor that form the contact area A1 and / or the contact area A2, and apply the ultrasonic waves so as to melt the energy director. The energy director is, for example, a protrusion such as that shown in 302 in FIG. 3(b). Because the energy director is provided on the first member precursor or the second member precursor, the vibrations of the ultrasonic waves are concentrated, allowing for favorable welding. The energy director begins to vibrate due to the ultrasonic waves, and melts and welds first at the locations where stress is concentrated.

[0104] 5. Impact absorbing materials and structures This is the same as the above-mentioned [First embodiment]. 6. Shock absorbing structure This is the same as the above-mentioned [First embodiment]. 7. Uneven thickness structure This is the same as the above-mentioned [First embodiment]. [Example]

[0105] 1. Evaluation (1) Material Polyamide 6 (A1030 manufactured by Unitika Ltd., sometimes abbreviated as PA6). Carbon fiber bundle (Tenax (registered trademark) STS40 24K manufactured by Teijin Limited, average fiber diameter 7 μm, single fiber count 24,000) (2) Evaluation method Tensile testing In preparation for the tensile test, reinforcing materials (25 mm wide x 25 mm deep) were attached to the outside of the recesses of the first and second components of the resulting bonded components. The reinforcing materials were made of the same material and thickness as the bonded components, and an adhesive made from ITW's MA530 mixed with an appropriate amount of glass beads was applied between each recess and the reinforcing material to bond them together. Pressure was applied to the reinforcing material just enough to prevent the glass beads in the adhesive from being crushed, and the material was then placed in a tank at an ambient temperature of 80°C and left for one hour to allow the adhesive to fully harden, after which it was returned to room temperature. A 9.5 mm diameter hole was drilled in the recess of the first member, and an M8 bolt made of SCM435 was inserted into it to secure the recess of the first member to the upper jig of the tensile tester. A nut made of S45C was used for fastening. A 6 mm thick, 20 mm wide plate made of SS400 was inserted into the recess of the second member, and the plate was then secured to the lower jig of the tensile tester. The tensile test was carried out using a universal testing machine 5982 manufactured by Instron at a tensile speed of 0.1 mm / sec.

[0106] [Example 1] (1) Preparation of composite material The carbon fibers were Tenax (registered trademark) STS40-24K carbon fibers cut to a fiber length of 20 mm, and the resin was Unitika nylon 6 resin A1030. A composite composition of carbon fibers and polyamide 6 with the carbon fibers oriented in a two-dimensional random pattern was prepared based on the method described in U.S. Patent No. 10,006,677. The resulting composite composition was heated at 2.0 MPa for 5 minutes in a press heated to 250°C, and a flat plate-shaped composite material measuring 600 mm x 1,000 mm and with an average thickness of 3 mm was prepared.

[0107] (2) Preparation of first component precursor and second component precursor The flat composite material prepared above was heated to above the softening point of the resin to soften it, placed in a press mold, and press-molded at a pressure of 20 MPa to prepare the hat-shaped first and second component precursors shown in Figure 2. Figure 10 shows a cross-sectional view of a roughly hexagonal joining component precursor, which was prepared by stacking two first and second component precursors together prior to the bending process. The dimensions of each part are shown in Figure 10, which shows the cross-sectional shape of the joining component precursor in a direction perpendicular to the longitudinal direction. The first and second component precursors were prepared so that the cross-sectional shape in the direction perpendicular to the longitudinal direction was uniform across the longitudinal direction of the joining component. In Fig. 10, the dimensions of each part in this example were a = 30 mm, b = 8 mm, c = 10 mm, d = 105 degrees, and the depth (Y direction) was 25 mm. The thickness t1 of the first member precursor and the second member precursor was uniform at 2.5 mm. The length of the portion to be bent in the first member precursor and the second member precursor was e = 20 mm, and the depth of the portion to be bent (Y direction in Fig. 10) was 10 mm, and the portion was provided in the center region in the depth direction of the first member precursor and the second member precursor.

[0108] (3) Bending The prepared first and second member precursors were partially heated to a maximum of 280°C using an infrared heating device (NGK Insulators H7GS, 86.25 kW / top and bottom surfaces) and bent to produce a bonded member. When heating using the infrared heating device, non-heated areas were provided with metal to allow for partial heating (masking), and then the bent parts were bent.

[0109] (4) Ultrasonic welding The contact area A1 and the contact area A2 formed by folding were ultrasonically welded at a frequency of 40 kHz and an amplitude of 70% using a Branson LPt handheld ultrasonic welder and a horn with a flange (diameter 10 mm) and a convex tip (convex height 3 mm, convex outer diameter 4.2 mm). A load was applied to the tip of the horn, bringing the first and second members into contact, and ultrasonically welding each of the folded sections. This resulted in a welding distance of approximately 80 to 100 mm per section. 2 The area was welded.

[0110] (5) Tensile test When a tensile test was performed, the maximum load during the test was 1.12 kN. The schematic diagram of the joint member after the tensile test is shown in Figure 8(b).

[0111] [Example 2] A bonded member was produced in the same manner as in Example 1, except that ultrasonic welding was not performed. The maximum load during the tensile test was 0.86 kN. A schematic diagram of the bonded member after the tensile test is shown in Figure 8(a). [Explanation of symbols]

[0112] 100, 200: Joint material 101, 201: First member 102, 202: Second member 103, 203: First bending part 104, 204: Second bending portion 105, 205, 107, 207: recessed parts 106: One end (flange portion) of the second member, the other end (flange portion) of the second member 206-1: Flange part (first member) 206-2: Flange part (second member) 301: Ultrasonic wave application device 302: Energy Director 303: Welded horn 304, 403, 503: Vibration welding area (corresponding to contact area B1 or contact area B2) 401, 501: Jig 402: Infrared heating device 502: Wedge 601D: Bottom part 601U:Top part 601Fr: Front part 601Rr: Rear part 601: Tip member 602L, 602R: Joint material (shock absorbing material) 603L, 603R: Base end member 600: Shock absorbing structure 701: Outer cylinder 702: Hollow part 703: Bending section

Claims

1. A joining member in which a first member and a second member are combined, The first member includes reinforcing fibers and a thermoplastic resin, In a cross section perpendicular to the longitudinal direction of the joining member, the first member and the second member form a closed cross-sectional shape, The first member has one end and another end in a width direction perpendicular to the longitudinal direction, the second member has one end and the other end in a width direction perpendicular to the longitudinal direction, a first bent portion at one end of the first member or one end of the second member; A second bent portion is provided at the other end of the first member or the other end of the second member. Joining material.

2. The joining member according to claim 1 , wherein the second member includes a thermoplastic resin and a reinforcing fiber.

3. The contact surface between one end of the first member and one end of the second member forms a contact surface area A1 formed by folding and a contact surface area B1 other than A1, The contact surface between the other end of the first member and the other end of the second member forms a contact surface area A2 formed by folding and a contact surface area B2 other than A2, The joint member according to claim 1 or 2, wherein the first member and the second member are welded together, with the contact area A1 and / or the contact area A2 being a joint portion.

4. The joining member according to claim 3 , wherein the contact surface area A1 and / or the contact surface area A2 is a welded portion.

5. One end of the first member and one end of the second member form a contact area A1 formed by folding and a contact area B1 other than A1, The other end of the first member and the other end of the second member form a contact area A2 formed by folding and a contact area B2 other than A2, The joining member according to claim 1 , wherein the first member and the second member are welded together, with the contact surface region B1 and / or the contact surface region B2 being the welded portion.

6. No adhesive is used to join the first member and the second member. The joining member according to any one of claims 1 to 5.

7. the first member includes reinforcing fibers and a thermoplastic resin; one end of the first member and the other end of the first member are bent to form the first bent portion and the second bent portion, respectively; One end of the second member is sandwiched between the first bent portion, The other end of the second member is sandwiched in the second bent portion. The joining member according to any one of claims 1 to 6.

8. The first member and the second member contain reinforcing fibers and a thermoplastic resin, one end of the first member and the other end of the second member are bent to form the first bent portion and the second bent portion, respectively; One end of the second member is sandwiched between the first bent portion, The other end of the first member is sandwiched in the second bent portion. The joining member according to any one of claims 1 to 6.

9. A method for manufacturing a joint member according to any one of claims 1 to 8, preparing a first member precursor for forming the first member and a second member precursor for forming the second member; the first member precursor has one end and the other end in a width direction perpendicular to the longitudinal direction, the second member precursor has one end and the other end in a width direction perpendicular to the longitudinal direction, one end of the first member precursor or one end of the second member precursor is heated and bent to form a first bent portion; the other end of the first member precursor or the other end of the second member precursor is heated and bent to form a second bent portion; A manufacturing method for a joining member.

10. The method for manufacturing a joining member according to claim 9, when one end of the first member precursor or one end of the second member precursor is heated and folded, the one end of the first member and the one end of the second member form a contact area A1 by folding; when the other end of the first member precursor or the other end of the second member precursor is heated and folded, the other end of the first member and the other end of the second member form a contact area A2 by folding; In the contact surface area A1 and / or the contact surface area A2, the thermoplastic resin contained in the first member precursor or the second member precursor that has been heated and bent is inserted into and welded to the second member precursor or the first member precursor that has been sandwiched by the bending process. The method for manufacturing a joint member according to claim 8 .

11. The method for manufacturing a joining member according to claim 10, When heating and bending the sheet, a jig is used. By providing a wedge in the jig, the thermoplastic resin contained in the first member precursor or the second member precursor is forced into the first member precursor or the second member precursor sandwiched by a bending process. A manufacturing method for a joining member.

12. providing holes in the first member precursor and / or the second member precursor to be sandwiched by the folding processing portion; providing a convex portion in a portion to be folded of the first member precursor and / or a portion to be folded of the second member precursor; The protrusion is inserted into the hole and welded. The method for manufacturing a joint member according to claim 10.

13. The method for manufacturing a joining member according to claim 9, when one end of the first member precursor or one end of the second member precursor is heated and folded, the one end of the first member and the one end of the second member form a contact area A1 by folding; when the other end of the first member precursor or the other end of the second member precursor is heated and folded, the other end of the first member and the other end of the second member form a contact area A2 by folding; The contact area A1 and / or the contact area A2 is welded by applying ultrasonic waves. A manufacturing method for a joining member.

14. 14. The method for manufacturing a joined member according to claim 13, wherein an energy director is provided on the first member precursor and / or the second member precursor that forms the contact surface area A1 and / or the contact surface area A2, and the ultrasonic wave is applied so as to melt the energy director.

15. The method for manufacturing a joining member according to claim 9, when one end of the first member precursor or one end of the second member precursor is heated and folded, the one end of the first member and the one end of the second member form a contact area A1 by folding; One end of the first member and one end of the second member form a contact surface area B1 other than the contact surface area A1, when the other end of the first member precursor or the other end of the second member precursor is heated and folded, the other end of the first member and the other end of the second member form a contact area A2 by folding; The other end of the first member and the other end of the second member form a contact area B2 other than the contact area A2, The contact surface area B1 and the contact surface area B2 are vibration-welded to manufacture a joined member. A manufacturing method for a joining member.

16. The method for manufacturing a joint member according to claim 9, wherein the bending is performed at a force of 10 N or less per mm.

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