Coupling member

Abstract

To provide a coupling member having increased strength against tension, compression, torsion, or the like so that it can be handled for more complex components and can withstand use under a higher load.SOLUTION: A coupling member comprises: an arm part made of a thermoplastic resin, which constitutes two coupling parts located at both end parts of the member and an extension part extending between the two coupling parts; a ring part surrounding the arm part, and made of a thermoplastic resin sheet reinforced with reinforcing fibers extending continuously in a circumferential direction; and a covering part made of the thermoplastic resin, which is arranged at least outside the ring part.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a connecting member. [Background technology]

[0002] Metal materials have traditionally been used for connecting components such as automobile suspension arms and stabilizer links because they require a certain level of mechanical strength. However, there are currently considerations of switching to plastic products in order to improve vehicle fuel efficiency. On the other hand, general resin products have the problem that they are not sufficient in terms of mechanical strength compared to metal materials, and there is a demand for improvements in mechanical strength, etc. Patent Document 1 describes a composite article formed from unidirectional fiber-reinforced tape. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Special Publication No. 2015-504790 Summary of the Invention [Problem to be solved by the invention]

[0004] In recent years, connecting components such as automobile suspension arms and stabilizer links have been required to withstand higher loads due to the increase in vehicle weight, especially in electric vehicles. Furthermore, as components become more complex, higher stresses are occurring not only in the tensile direction but also in the compressive and torsional directions. However, in order to improve the strength of the composite article described in Patent Document 1 against tension, compression, torsion, etc., a common approach would be to increase the thickness of the product. Increasing the thickness to provide the required strength increases the likelihood of voids forming in the product, which can become the starting point for fracture, and this could actually lower the strength, leaving room for improvement in terms of strength, etc.

[0005] Therefore, an object of the present invention is to provide a connecting member having increased strength against tension, compression, torsion, etc. so that it can accommodate the more complex components required in recent years and can withstand use under higher loads. [Means for solving the problem]

[0006] A connecting member according to a first aspect of the present invention comprises: (1) an arm portion made of a thermoplastic resin, which comprises two connecting portions located at both ends of the member and an extension portion extending between the two connecting portions; a ring portion surrounding the arm portion and made of a thermoplastic resin sheet reinforced with reinforcing fibers extending continuously in the circumferential direction; a covering portion made of a thermoplastic resin and disposed at least on the outer side of the ring portion; A connecting member comprising:

[0007] In one embodiment of the present invention, a connecting member includes: (2) The arm portion has a weld line on the extension portion. (1) A connecting member as described above.

[0008] In one embodiment of the present invention, a connecting member includes: (3) The coating portion has a weld line, In the axial direction of the connecting member, the position of the weld line of the arm portion and the position of the weld line of the covering portion are misaligned. (2) A connecting member according to the present invention.

[0009] In one embodiment of the present invention, a connecting member includes: (4) The reinforcing fiber reinforcing the ring portion is carbon fiber. The connecting member is described in any one of (1) to (3).

[0010] In one embodiment of the present invention, a connecting member includes: (5) the thermoplastic resin of the arm portion, the ring portion, and the covering portion is a polyamide resin; The connecting member is described in any one of (1) to (4).

[0011] In one embodiment of the present invention, a connecting member includes: (6) The arm portion and the covering portion contain reinforcing fibers, and the reinforcing fibers are both glass fibers. The connecting member is described in any one of (1) to (5).

[0012] In one embodiment of the present invention, a connecting member includes: (7) The arm portion and the covering portion are formed in two stages. The connecting member is described in any one of (1) to (6).

[0013] In one embodiment of the present invention, a connecting member includes: (8) The arm portion and the covering portion are both formed by injection molding. The connecting member is described in any one of (1) to (7). [Effects of the Invention]

[0014] According to the present invention, a connecting member having increased strength against tension, compression, torsion, or the like can be provided. [Brief explanation of the drawings]

[0015] [Figure 1] FIG. 2 is a perspective view showing an example of the configuration of a connecting member according to the present embodiment. [Figure 2] FIG. 2 is a perspective view showing the state in which a covering portion is removed in FIG. [Figure 3] FIG. 2 is a plan view showing a first modified example of the arm portion of FIG. [Figure 4] 1. FIG. 4 is a plan view showing a second modified example of the arm portion of FIG. [Figure 5] 1. FIG. 4 is a plan view showing a third modified example of the arm portion of FIG. [Figure 6] FIG. 2 is a plan view showing the state in which the covering portion is removed in FIG. [Figure 7] FIG. 2 is a plan view showing the connecting member of FIG. [Figure 8] 2 is a graph showing the results of a tensile fracture test carried out on the connecting member of FIG. 1. [Figure 9] 2 is a graph showing the results of a compression fracture test carried out on the connecting member of FIG. 1. DETAILED DESCRIPTION OF THE INVENTION

[0016] Hereinafter, a mode for carrying out the present invention (hereinafter referred to as "the present embodiment") will be described in detail. Note that the present invention is not limited to the following embodiment, and various modifications can be made within the scope of the gist of the present invention.

[0017] FIG. 1 is a diagram showing a connecting member 100 as a first embodiment of the connecting member according to the present invention.

[0018] The connecting portions 11, 11' may be connected to a mechanical component. More specifically, one of the connecting portions 11, 11' may be connected to a vehicle body. The other of the connecting portions 11, 11' may be connected to a wheel support member. The connecting portions 11, 11' may include a first cylindrical portion 11A, a vibration-isolating portion 11B attached to the outer circumferential surface of the cylindrical portion 11A, and a second cylindrical portion 11C attached to the outer circumferential surface of the vibration-isolating portion 11B. An elastic bushing, a ball joint, or the like may be inserted into the first cylindrical portion 11A. The first cylindrical portion 11A and the second cylindrical portion 11C may be made of metal. The vibration-isolating portion 11B may be made of vibration-isolating rubber. Note that the connecting portions 11, 11' may not be provided with the vibration-isolating portion 11B or the second cylindrical portion 11C. The linkage member 100 may be a suspension arm, a stabilizer link, a torque rod, a motor mount, a swing arm, or a robot arm.

[0019] The connecting member 100 of this embodiment comprises an arm portion 10 made of thermoplastic resin, a ring portion 20 made of a thermoplastic resin sheet that surrounds the arm portion 10 and is reinforced with reinforcing fibers that extend continuously in the circumferential direction, and a covering portion 30 made of thermoplastic resin and arranged at least outside the ring portion 20.

[0020] The arm portion 10 comprises two connecting portions 11, 11' located at both ends of the connecting member 100, and an extending portion 12 extending between the two connecting portions 11, 11'. The arm portion 10 may be rod-shaped with both ends curved in the axial direction.

[0021] One or more notches 13 may be formed in the edge of the arm portion 10. With reference to Fig. 2, the notches 13 may be located on either side of the edge of the ring portion 20 (on both sides in Fig. 2). With reference to Figs. 1 and 2, some 13C of the notches 13 may be located at the center of the arm portion 10 in the width direction (i.e., the center of the curved portion).

[0022] 3, in arm portion 10' of the first modified example of the connecting member of the present embodiment, the inner diameter of first cylindrical portion 11A1 of one connecting portion is larger than the inner diameter of first cylindrical portion 11A2 of the other connecting portion. The other configuration is similar to that of connecting member 100 (FIG. 7).

[0023] Referring to FIG. 4, the arm portion 10'' in the second modified example of the connecting member of this embodiment has a width that expands along the central axis A'. The inner diameter of the first cylindrical portion 11A1 of one connecting portion is larger than the inner diameter of the first cylindrical portion 11A2 of the other connecting portion. In plan view, the contour of the expanded diameter portion 12E of the extension portion 12 may be linear. The other configurations are similar to those of the connecting member 100.

[0024] Referring to FIG. 5, the arm portion 10''' in the third modified example of the connecting member of this embodiment has a width that is wide at both ends in the direction of the central axis A' and narrow at the center in the direction of the central axis A'. In other words, a narrowed portion is present in the extension portion 12 in plan view. The presence of a narrowed portion in the extension portion 12 can reduce the weight of the connecting member 100. The contour of the narrowed portion of the extension portion 12 in plan view may be curved. The other configurations are similar to those of the connecting member 100.

[0025] 1 and 6, the extension portion 12 may be hollowed out. The hollowing may be provided in the height direction of the extension portion 12. The hollowing may be provided on both main surfaces of the extension portion 12. The extension portion 12 may be hollowed out, leaving ribs 14. The ribs 14 may include ribs 14A extending in the axial direction, ribs 14B extending perpendicular to the axial direction, ribs 14C extending along the second cylindrical portion 11C, and ribs 14D having one end adjacent to the connecting portions 11, 11' and the other end located at the edge of the extension portion 12. The ribs 14B may be adjacent to the notches 13. On the other hand, it is preferable that the outer peripheral surface of the extension portion 12 is not hollowed out, from the viewpoint of ensuring the tensile strength of the connecting member 100.

[0026] The thickness of the arm portions 10, 10', 10'', 10''' can be adjusted appropriately depending on the shape, but is preferably 1.0 to 3.0 mm from the following viewpoints. 1) When using a material containing reinforcing fibers, which will be described later, the reinforcing fibers can be oriented in a preferred manner, thereby further increasing the strength. 2) The resin can be filled sufficiently, preventing the occurrence of voids that could be the starting point of fracture. 3) By optimizing the cooling time during injection molding, etc., the product can be given an appropriate shape (reducing warping, etc.).

[0027] The ring portion 20 is a composite material obtained by compounding a thermoplastic resin (described later) with fibers. The fibers are reinforcing fibers. The fibers extend continuously in the circumferential direction. More specifically, in a portion 20A of the ring portion 20 extending in the axial direction, the reinforcing fibers extend in the axial direction. In a portion 20C of the ring portion 20 that follows the curved portion of the outer peripheral surface of the arm portion 10, the reinforcing fibers follow the curved portion.

[0028] 2, the ring portion 20 surrounds the arm portion 10. More specifically, the ring portion 20 may be annular. The ring portion 20 may cover at least a portion of the outer circumferential surface of the arm portion 10. The ring portion 20 may cover the center of the outer circumferential surface of the arm portion 10 in the height direction.

[0029] 1 and 2, the covering portion 30 is disposed at least on the outside of the ring portion 20. By providing the covering portion 30, the ring portion 20 can withstand stress in any of the tensile, compressive, and torsional directions, and can also withstand higher loads. The covering portion 30 may be annular. The covering portion 30 may completely cover the outer peripheral surface of the ring portion 20. The covering portion 30 may completely cover the outer peripheral surface of the arm portion 10. The thickness of the covering portion 30 may be thicker in the vicinity of the connecting portions 11, 11' formed by the arm portion 10.

[0030] By providing the covering portion 30 disposed at least on the outside of the ring portion 20, the strength of the connecting member 100 against tension, compression, torsion, etc. can be increased without increasing the thickness more than necessary. Furthermore, damage to the ring portion 20 due to chipping can be reduced, for example, when a vehicle equipped with the connecting member 100 is running. Furthermore, by firmly welding the arm portion 10, the ring portion 20, and the covering portion 30 together, peeling and falling off of the interfaces between these members due to thermal cycling can be reduced. Furthermore, while thickening a member to improve its strength can lead to the risk of sink marks and voids, the connecting member 100 can reduce the occurrence of such molding defects.

[0031] The arm portion 10, the ring portion 20, and the covering portion 30 contain a thermoplastic resin. Examples of the thermoplastic resin include phenoxy resin, acrylic resin, methacrylic resin, polyvinyl acetal resin, thermoplastic polyimide resin, polyamide resin, polyamideimide resin, polyphenylene oxide resin, polyethersulfone resin, polyester resin, polyethylene resin, polystyrene resin, polysulfone resin, polybutadiene resin, ABS resin, coumarone resin, polyolefin resin, and polyarylene sulfide resin.

[0032] The thermoplastic resins may be used singly or in combination of two or more types having different weight average molecular weights, or in combination of one or more types and their prepolymers.

[0033] Among these, it is preferable to use one or more resins selected from the group consisting of polyimide resins, polyamide resins, polyolefin resins, and polyarylene sulfide resins.

[0034] The arm portion 10 and the covering portion 30 may include reinforced fibers.

[0035] Examples of types of reinforcing fibers that may be used in the arm portion 10 and the covering portion 30 include carbon fiber, glass fiber, aramid fiber, boron fiber, PBO fiber, high-strength polyethylene fiber, alumina fiber, and silicon carbide fiber. From the viewpoints of mechanical properties, thermal properties, and versatility, glass fiber, carbon fiber, and aramid fiber are preferred, and from the viewpoint of productivity, carbon fiber and glass fiber are preferred, with glass fiber being most preferred.

[0036] The reinforcing fibers may be used alone or in combination of two or more.

[0037] The ring portion 20 is made of a thermoplastic resin sheet reinforced with reinforcing fibers. The thermoplastic resin is as described above, and polyamide resin is particularly preferred.

[0038] The reinforcing fibers used in the ring portion 20 are preferably continuous reinforcing fibers. There are no limitations on the form or arrangement of the fibers, and examples thereof include fiber structures such as unidirectionally aligned long fibers, a single tow, woven fabric, knitted fabric, and braided cord, but unidirectionally aligned long fibers are most preferred.

[0039] The most preferable reinforcing fiber used in the ring portion 20 is carbon fiber. -Carbon fiber- Carbon fiber is a fiber made by carbonizing acrylic fiber or pitch (a by-product of petroleum, coal, coal tar, etc.) at high temperatures. In particular, acrylic carbon fibers having high tensile strength are preferably used.

[0040] Commercially available carbon fibers include "Tenax (registered trademark)" UTS50 and "Tenax (registered trademark)" IMS60 (both manufactured by Teijin Limited), "Torayca (registered trademark)" T700S and "Torayca (registered trademark)" T800H (both manufactured by Toray Industries, Inc.), "PYROFIL (registered trademark)" TR50S, "PYROFIL (registered trademark)" MR60H and "DIALEAD (registered trademark)" K1352U (all manufactured by Mitsubishi Chemical Group Corporation), and "GRANOC (registered trademark)" YSH50A (all manufactured by Nippon Graphite Fiber Co., Ltd.).

[0041] The connecting member 100 may be produced by injection molding using a mold. Any known injection molding method may be used, but from the viewpoint of production efficiency, a method in which the arm portion 10 and the covering portion 30 are injection molded is preferred. A method in which the arm portion 10 and the covering portion 30 are injection molded separately is sometimes called two-stage molding. Examples of two-stage molding include the following methods. 1) The arm portion 10 is injection molded, and the ring portion 20 is formed by surrounding the arm portion 10 with a thermoplastic resin sheet reinforced with reinforcing fibers so that the thermoplastic resin sheet extends continuously in the circumferential direction (sometimes called lay-up molding), and then the covering portion 30 is injection molded. 2) It can also be obtained by mounting a thermoplastic resin sheet in a mold to form the ring portion 20, and then injection molding the arm portion 10 and the covering portion 30, respectively. The order in which the arm portion 10 and the covering portion 30 are injection molded does not matter.

[0042] As an example of two-stage molding of the arm portion 10 and the covering portion 30, the ring portion 20 and the connecting portions 11, 11' may be placed in a mold first, and resin may be filled in through gates 15, 15' to form the arm portion 10. Then, the arm portion 10, the ring portion 20, and the connecting portions 11, 11' may be placed in another mold, and resin may be filled in through gates 35, 35' to form the covering portion 30. Alternatively, the covering portion 30 may be injection molded first, and then the arm portion 10 may be injection molded.

[0043] The mold may have a protrusion formed thereon to form the notch 13. Providing such a protrusion can improve adhesion between the covering portion 30 and the arm portion 10, thereby increasing strength. Furthermore, a protrusion or the like for forming the notch 13C disposed at the center of the width of the arm portion 10 may be used to attach the connecting portions 11, 11' to the center of the width of the mold. A protrusion or the like for forming the notch 13 may be used to adjust the height position of the ring portion 20.

[0044] As described above, the arm portion 10 may be injection molded. In a plan view of the connecting member 100 ( FIG. 7 ), the arm portion 10 may have gates 15, 15′ at the two connecting portions 11, 11′, respectively, which are positioned substantially symmetrically with each other with respect to the midpoint of a line segment connecting the centers of the two connecting portions 11, 11′. The gates 15, 15′ may be positioned at the widthwise ends of the arm portion 10. The gates 15, 15′ may be positioned at the boundaries between the connecting portions 11, 11′ and the extension portion 12.

[0045] By filling the resin through two or more gates 15, 15', a weld line may be present at any position in the extension portion 12. The weld line may be present near the axial center of the extension portion 12. The weld line may be perpendicular to the axial direction of the extension portion 12.

[0046] As described above, the covering portion 30 may be injection molded. In a plan view of the connecting member 100 ( FIG. 7 ), the covering portion 30 may have gates 35, 35′ in the two connecting portions 11, 11′, respectively, that are positioned substantially symmetrically with each other with respect to the midpoint of a line segment connecting the centers of the two connecting portions 11, 11′. The positions of the gates 15, 15′ of the arm portion 10 and the positions of the gates 35, 35′ of the covering portion 30 may be on opposite sides of the central axis A of the arm portion 10 and may coincide with each other in the axial direction of the arm portion 10. The gates 35, 35′ may be located on the inner edge of the covering portion 30. The gates 35, 35′ may be located near the boundaries between the connecting portions 11, 11′ and the extension portion 12.

[0047] By filling the resin through two or more gates 35, 35', the covering portion 30 may have a weld line. From the viewpoint of further increasing the tensile strength of the connecting member 100, it is preferable that the position of the weld line of the arm portion 10 and the position of the weld line of the covering portion 30 are misaligned in the axial direction of the connecting member 100.

[0048] As mentioned above, the thermoplastic resin used for the arm portion 10 and the covering portion 30 preferably contains reinforcing fibers. With the connecting member of this embodiment, as mentioned above, it is not necessary to make the product thicker than necessary, and in this case, the reinforcing fibers in the product can be properly oriented. If the reinforcing fibers have a proper orientation, higher strength can be achieved. The orientation of the reinforcing fibers occurs by injection molding a thermoplastic resin containing reinforcing fibers.

[0049] The connecting member 100 of this embodiment may be further subjected to surface functionalization treatments such as flame-retardant coating, weather-resistant coating, electromagnetic wave shielding treatment, and anti-reflection treatment depending on the properties required for the application. [Example]

[0050] The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples.

[0051] Leona 14G50 manufactured by Asahi Kasei Corporation was used as the raw material for the arm portion 10 and the covering portion 30.

[0052] The manufacturing method of the raw material used for the ring portion 20 will be described below. <Method of manufacturing polyamide resin film> Polyamide 66 / 6I resin was fed into an extruder and melt-kneaded at a plasticization temperature of 260°C. Next, it was co-extruded with low-density polyethylene (LDPE), which had also been melt-kneaded at a plasticization temperature of 260°C, through a film die at a film-forming speed of 20 m / min to form a film with a width of 1250 mm. After that, while being wound around a cooling roll at 80°C, 125 mm was cut off on both ends using a slitting machine, and the LDPE film was peeled off from the polyamide film, yielding a polyamide resin film with a width of 1000 mm and a thickness of 25 μm. <Method of manufacturing fiber-reinforced resin substrate> Carbon fiber (Tenax® UTS50-24K manufactured by Teijin Limited) was used, and the weight of the fiber was 90 g / m2, which was then cut into parallel, horizontal sheets from each reel. 2 The polyamide resin films prepared above were fed onto the top and bottom surfaces of the substrate, and the films were heated at a predetermined temperature and pressed in a semi-molten state to integrate the carbon fibers and the polyamide resin, thereby obtaining a fiber-reinforced resin substrate having a carbon fiber content of 50% by volume, a width of 1000 mm and a thickness of 0.1 mm.

[0053] [Method of manufacturing connecting members] The above-mentioned fiber reinforced resin substrate (forming the ring portion 20) was heated to a surface temperature of 260°C, and 10 layers of the substrate were heat-welded to produce the ring portion 20. Thereafter, the substrate was inserted into an injection molding die heated to 80°C. The thermoplastic resin that constitutes the arm portion 10 was molded at a resin temperature of 290°C (injection speed 120 mm / sec) to obtain a molded product that constitutes the arm portion 10 and the ring portion 20.This was then inserted into another cavity, and the thermoplastic resin that constitutes the covering portion 30 was injection molded at a resin temperature of 290°C (injection speed 120 mm / sec) to obtain the connecting member 100.

[0054] A steel jig was placed inside the first cylindrical portion 11a of the connecting portions 11, 11' of the connecting member 100 shown in FIG.

[0055] A tensile fracture test was performed on the connecting member 100 at 80°C and 50% RH using a universal testing machine (100 kN load cell). The tensile load was gradually increased until the connecting member 100 broke. The fracture load was 73.4 kN. The results are shown in Figure 8.

[0056] A compression failure test was performed on the connecting member 100 at 80°C and 50% RH. The compressive load was gradually increased until the sample failed. The failure load was 39.0 kN. The results are shown in Figure 9.

[0057] Testing has shown that the connecting member 100 depicted in FIG. 1 has sufficient strength in tension and compression. [Industrial Applicability]

[0058] The connecting member of the present invention is suitable for application to a suspension arm, a stabilizer link, a torque rod, a motor mount, a swing arm, or a robot arm. [Explanation of symbols]

[0059] 100 Connecting member 10,10',10'' arm 11,11' Connecting part 11A, 11A1, 11A2 First cylindrical part 11B Anti-vibration part 11C Second cylindrical section 12 Extension 12E Expanded section 12R Waist 13, 13C notch 14, 14A, 14B, 14C, 14D Ribs 15,15' gate 20 Ring section 30 Covering part 30H through hole 35,35' gate A, A' central axis

Claims

1. an arm portion made of a thermoplastic resin, which comprises two connecting portions located at both ends of the member and an extension portion extending between the two connecting portions; a ring portion surrounding the arm portion and made of a thermoplastic resin sheet reinforced with reinforcing fibers extending continuously in the circumferential direction; a covering portion made of a thermoplastic resin and disposed at least on the outer side of the ring portion; A connecting member comprising:

2. The arm portion has a weld line on the extension portion. The connecting member according to claim 1 .

3. The coating portion has a weld line, In the axial direction of the connecting member, the position of the weld line of the arm portion and the position of the weld line of the covering portion are misaligned. The connecting member according to claim 2 .

4. The connecting member according to any one of claims 1 to 3, wherein the reinforcing fiber that reinforces the ring portion is a carbon fiber.

5. 4. The connecting member according to claim 1, wherein the thermoplastic resin of the arm portion, the ring portion and the covering portion is a polyamide resin.

6. The connecting member according to any one of claims 1 to 3, wherein the arm portion and the covering portion contain reinforcing fibers, and the reinforcing fibers are both glass fibers.

7. The arm portion and the covering portion are formed in two stages. The connecting member according to any one of claims 1 to 3.

8. The connecting member according to any one of claims 1 to 3, wherein the arm portion and the covering portion are both formed by injection molding.

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