Method for manufacturing a fiber-reinforced resin-made pipe

Abstract

Provided is a method for manufacturing a fiber-reinforced resin pipe body that can ensure a gap in a mold and suppress the weight of the pipe body. The method for manufacturing a fiber-reinforced resin pipe body includes a disposing step (S4, S5, S6), an expanding step (S8), and a molding step (S9), wherein in the disposing step (S4, S5, S6), disposing is performed on the outer peripheral surface of a mandrel by a filament winding method; after the disposing step (S4, S5, S6), in the expanding step (S8), the mandrel on which the fiber body is disposed is disposed in a mold, and the inside of the mandrel on which the fiber body is disposed is pressurized, whereby the mandrel 10 is expanded; and after the expanding step (S8), in the molding step (S9), resin is supplied into the mold, the resin is impregnated in the fiber body, and the impregnated resin 54 is cured, whereby the pipe body is molded.

Description

Technical Field

[0001] The present invention relates to a method for manufacturing a fiber-reinforced resin pipe body for use as, for example, a drive shaft in a vehicle. Background Technology

[0002] The propeller shaft mounted on a vehicle has a tube extending in the longitudinal direction of the vehicle, through which power generated by the prime mover and reduced by the transmission is transmitted to the final reduction gear. As a tube for such a propeller shaft, there is a tube made of fiber-reinforced plastic using a mandrel (see Patent Document 1).

[0003] In contrast, Patent Document 2 describes a method for winding material onto a mandrel, in which resin-impregnated fibers are wound onto the mandrel using a filament winding method, and the resin-impregnated fibers are cured by autoclaving. Furthermore, Patent Document 3 describes a method where, after winding unimpregnated fibers onto a mandrel, resin is impregnated onto the fibers within a mold.

[0004] [Existing technical documents]

[0005] [Patent Literature]

[0006] Patent Document 1: Japanese Invention Patent Publication No. 3-265738

[0007] Patent Document 2: Japanese Patent Publication No. 2003-127257

[0008] Patent Document 3: Japanese Patent Publication No. 8-323870 Summary of the Invention

[0009] [The technical problem that the invention aims to solve]

[0010] In the technology described in Patent Document 3, the fibrous material may become embedded in the mold. In contrast, if it is desired to ensure clearance within the mold to prevent the fibrous material from becoming embedded, the amount of resin supplied to the fibrous material will increase by the amount of such clearance, thereby potentially increasing the weight of the finished tube.

[0011] The present invention was made to solve the problem of providing a method for manufacturing a fiber-reinforced resin tube that can ensure the gap within the mold and suppress the weight of the tube.

[0012] [Technical solutions used to solve technical problems]

[0013] To solve the aforementioned technical problem, the method for manufacturing a fiber-reinforced resin tube of the present invention is characterized by comprising a configuration step, an expansion step, and a molding step, wherein, in the configuration step, a fiber body is configured on the outer peripheral surface of a resin mandrel by a filament winding method; after the configuration step, in the expansion step, the mandrel with the fiber body configured is placed in a mold, and pressure is applied to the interior of the mandrel with the fiber body configured, thereby causing the mandrel to expand; after the expansion step, in the molding step, resin is supplied into the mold and the resin is impregnated with the fiber body and the impregnated resin is cured, thereby molding the tube.

[0014] [Invention Effects]

[0015] According to the present invention, a gap can be ensured when the mandrel containing the fiber body is placed in the mold, thereby preventing the fiber body from becoming embedded in the mold. Furthermore, the expansion shape of the mandrel can be appropriately set according to the shape inside the mold, and the amount of resin in the finished fiber-reinforced resin tube can be prevented from increasing, thereby suppressing the weight of the tube. Attached Figure Description

[0016] Figure 1 This is a schematic cross-sectional view of a fiber-reinforced resin tube according to the first embodiment of the present invention.

[0017] Figure 2 This is a flowchart illustrating the manufacturing method of a fiber-reinforced resin tube according to the first embodiment of the present invention.

[0018] Figure 3 This is a schematic cross-sectional view illustrating the mandrel forming step, the first connecting step, and the second connecting step of the method for manufacturing a fiber-reinforced resin tube according to the first embodiment of the present invention.

[0019] Figure 4 This is a schematic diagram illustrating the configuration steps of the manufacturing method of the fiber-reinforced resin tube body according to the first embodiment of the present invention.

[0020] Figure 5 This is a schematic diagram illustrating the configuration steps of the manufacturing method of the fiber-reinforced resin tube body according to the first embodiment of the present invention.

[0021] Figure 6 This is a schematic diagram illustrating the configuration steps of the manufacturing method of the fiber-reinforced resin tube body according to the first embodiment of the present invention.

[0022] Figure 7This is a schematic cross-sectional view illustrating the mold setting step in the method for manufacturing a fiber-reinforced resin tube according to the first embodiment of the present invention.

[0023] Figure 8 This is a schematic cross-sectional view illustrating the expansion step and resin impregnation step of the method for manufacturing a fiber-reinforced resin tube according to the first embodiment of the present invention.

[0024] Figure 9 This is a schematic cross-sectional view of a fiber-reinforced resin tube according to the second embodiment of the present invention.

[0025] Figure 10 This is a flowchart illustrating the manufacturing method of the fiber-reinforced resin tube according to the second embodiment of the present invention.

[0026] Figure 11 This is a schematic diagram illustrating the mandrel and fiber body involved in the first variation of the present invention.

[0027] Figure 12 This is a schematic cross-sectional view of the mold used in the mandrel forming step of the method for manufacturing a fiber-reinforced resin tube according to the first variation of the present invention.

[0028] Figure 13 This is a schematic cross-sectional view of a fiber-reinforced resin tube according to a second variation of the present invention.

[0029] Figure 14 This is a schematic cross-sectional view of a mold used to illustrate the manufacturing method of a fiber-reinforced resin tube according to a second variation of the present invention. Detailed Implementation

[0030] Taking the case of using carbon fiber reinforced plastic to manufacture a vehicle propeller shaft with a fiber-reinforced resin tubular body as an example, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description, the same reference numerals are used for the same elements and repeated descriptions are omitted. In addition, the accompanying drawings are exaggerated for ease of understanding and do not accurately represent the shape, size, etc. of each component.

[0031] <First Implementation>

[0032] <Pipe body>

[0033] like Figure 1As shown, the fiber-reinforced resin tube body (hereinafter referred to as "tube body") 1A according to the first embodiment of the present invention has a mandrel 10, a first connecting member 20, a second connecting member 30, a third connecting member 40, a resin-containing fiber layer 50, and a resin layer 60A. In other words, the tube body 1A is composed of the resin-containing fiber layer 50 and the resin layer 60A, and the first connecting member 20, the second connecting member 30, and the third connecting member 40 are connected to the tube body 1A. In addition, the mandrel 10 is the core material of the tube body 1A.

[0034] <Heart axis>

[0035] The mandrel 10 is a cylindrical resin component. In this embodiment, the mandrel 10 functions as the core material of the tube body 1A. The material of the mandrel 10 can be any material capable of withstanding the heat generated during the curing of the resin containing the resin fiber layer 50. Examples of materials for the mandrel 10 include PP (polypropylene resin), PET (polyethylene terephthalate resin), and SMP (shape memory polymer). The mandrel 10 integrally comprises a large-diameter portion 11 at the axial center, a tapered portion 12 and a middle-diameter portion 13 formed at one axial end, a stepped portion 14 and a small-diameter portion 15 formed at the other axial end. Before manufacturing the tube body 1A, the large-diameter portion 11 of the mandrel 10 is cylindrical with the same diameter throughout the entire axial direction (see reference). Figure 3 After manufacturing the tube body 1A, the large-diameter portion 11 of the mandrel 10 takes the shape of a barrel that expands radially from the axial middle portion. That is, the outer diameter of the mandrel 10 decreases from the axial middle portion toward both axial ends.

[0036] <First connecting component>

[0037] The first connecting member 20 is a columnar member that is inserted into one axial end of the spindle 10. In this embodiment, the first connecting member 20 is a short metal shaft. The first connecting member 20 integrally comprises a large-diameter portion 21, a small-diameter portion 22, and a medium-diameter portion 23 sequentially from the spindle 10 side. The large-diameter portion 21 is a portion that is partially inserted into the medium-diameter portion 13 of the spindle 10. The small-diameter portion 22 and the medium-diameter portion 23 are portions that protrude from the spindle 10. An external gear formed on the outer peripheral surface of the large-diameter portion 21 meshes with an internal gear formed on the inner peripheral surface of the medium-diameter portion 13 of the spindle 10. Accordingly, the circumferential movement (rotation) of the first connecting member 20 relative to the spindle 10 is restricted.

[0038] <Second connecting component>

[0039] The second connecting member 30 is a cylindrical component externally fitted into the stepped portion 14 of the mandrel 10. An internal gear formed on the inner circumferential surface of the second connecting member 30 meshes with an external gear formed on the outer circumferential surface of the stepped portion 14 of the mandrel 10. Accordingly, the circumferential movement (rotation) of the second connecting member 30 relative to the mandrel 10 is restricted. In this embodiment, the second connecting member 30 is a metal collar, fixed to the mandrel 10 by a spline engagement. The outer diameter of the second connecting member 30 is approximately equal to the outer diameter of the major diameter portion 11 of the mandrel 10 before expansion.

[0040] <Third connecting component>

[0041] The third connecting member 40 is an externally fitted component to the small-diameter portion of the spindle 10 and connected to the second connecting member 30. One axial end of the third connecting member 40 abuts against the boundary of the stepped portion 14 and the small-diameter portion 15 of the spindle 10 and the other axial end of the second connecting member 30. In this embodiment, the third connecting member 40 is a short metal fork, which is joined to the second connecting member 30 by laser welding.

[0042] <Resin-containing fiber layer>

[0043] A resin-containing fiber layer 50 is disposed on the outer peripheral surfaces of the large-diameter portion 11, the tapered portion 12, the intermediate-diameter portion 13 of the mandrel 10, the large-diameter portion 21 of the first connecting member 20, and the second connecting member 30. The resin-containing fiber layer 50 sequentially comprises a first carbon fiber layer 51 (see reference 1) from the radially inward side (mandrel 10 side). Figure 4 ), second carbon fiber layer 52 (refer to) Figure 5 ) and the third carbon fiber layer 53 (refer to) Figure 6 ) as a carbon fiber layer. Furthermore, in Figures 4-6 The figure only shows a portion of each carbon fiber layer 51, 52, and 53. Furthermore, the outer peripheral surfaces of one axial end of the large-diameter portion 21 of the first connecting member 20 (the axial end of the first connecting member 20 located on the opposite side of the mandrel 10) and the other axial end of the second connecting member 30 (the axial end of the second connecting member 30 located on the opposite side of the mandrel 10) are not covered by the resin-containing fiber layer 50 and are exposed from it.

[0044] The First Carbon Fiber Layer

[0045] like Figure 4 As shown, the first carbon fiber layer 51 is composed of multiple carbon fibers disposed on the outer peripheral surface of the mandrel 10, etc., in a manner that covers the mandrel 10. The carbon fibers in the first carbon fiber layer 51 extend parallel to the axial direction of the mandrel 10. That is, with respect to the first carbon fiber layer 51, the orientation angle of the carbon fibers relative to the axis X of the mandrel 10 is 0°.

[0046] The second carbon fiber layer

[0047] like Figure 5 As shown, the second carbon fiber layer 52 is disposed radially outside the first carbon fiber layer 51 and is composed of multiple carbon fibers arranged to cover the first carbon fiber layer 51. The carbon fibers in the second carbon fiber layer 52 are wound at least one turn at an angle of 45° relative to the axial direction of the mandrel 10 and extend in a spiral manner relative to the axial direction of the mandrel 10. That is, regarding the second carbon fiber layer 52, the orientation angle of the carbon fibers relative to the axis X of the mandrel 10 is 45° before the mandrel 10 expands.

[0048] The Third Carbon Fiber Layer

[0049] like Figure 6 As shown, the third carbon fiber layer 53 is disposed radially outside the second carbon fiber layer 52, and is composed of multiple carbon fibers arranged to cover the second carbon fiber layer 52. The carbon fibers in the third carbon fiber layer 53 are wound at least one turn at an inclination of -45° relative to the axial direction of the mandrel 10, and extend in a spiral manner relative to the axial direction of the mandrel 10. That is, regarding the third carbon fiber layer 53, the orientation angle of the carbon fibers relative to the axis X of the mandrel 10 is -45° before the mandrel 10 expands.

[0050] <Resin Layer>

[0051] like Figure 1 As shown, the resin layer 60A is an annular layer disposed on the outer peripheral surface of the large-diameter portion 21 of the first connecting member 20. The thickness of the resin layer 60 is approximately equal to the thickness of the resin-containing fiber layer 50. The resin layer 60A covers and protects the portion of the large-diameter portion 21 of the first connecting member 20 that is exposed from the resin-containing fiber layer 50.

[0052] <Tube Manufacturing Method>

[0053] Next, use Figure 2 The flowchart is used to illustrate the manufacturing method of the tube body 1A according to the first embodiment.

[0054] First, such as Figure 3 As shown, a resin mandrel 10 is formed using a molding device (mold) not shown (step S1, mandrel forming step). Next, a first connecting member (short shaft) 20 is provided at one end of the mandrel 10 along its axial direction (step S2, first connecting step). Then, a second connecting member (collar) 30 is provided at the other end of the mandrel 10 along its axial direction (step S3, second connecting step). The order of steps S2 and S3 can be appropriately changed; step S3 can be performed first, or they can be performed simultaneously.

[0055] Next, as Figure 4As shown, a first carbon fiber layer 51 is formed on the outer peripheral surfaces of the mandrel 10, the large-diameter portion 21 of the first connecting member 20, and the second connecting member 30 using a device not shown (step S4, first carbon fiber layer formation step, arrangement step). Next, as... Figure 5 As shown, a second carbon fiber layer 52 is formed on the outer peripheral surface of the first carbon fiber layer 51 on the mandrel 10, the first connecting member 20, and the second connecting member 30 using a device not shown (step S5, second carbon fiber layer formation step, arrangement step). Next, as... Figure 6 As shown, a third carbon fiber layer 53 is formed on the outer peripheral surface of the second carbon fiber layer 52 on the mandrel 10, the first connecting member 20, and the second connecting member 30 using a device not shown (step S6, third carbon fiber layer formation step, arrangement step). In steps S4 to S6, carbon fiber layers 51 to 53 are formed such that no individual fibers are arranged on the ends of the first connecting member 20 and the second connecting member 30 located on opposite sides of the mandrel 10 along their respective axial directions.

[0056] In steps S4 to S6, each carbon fiber layer 51 to 53 is raw silk, not resin-impregnated fiber. Furthermore, each carbon fiber layer 51 to 53 is disposed on the outer peripheral surface of the large-diameter portion 21 of the mandrel 10 and the first connecting member 20 using a multi-filament winding method. Each carbon fiber layer 51 to 53, fed by the multi-filament winding method, exhibits a non-crimp structure, meaning it is not woven together but exists as an independent layer.

[0057] Alternatively, before the configuration steps S4 to S6, a process of pressurizing the interior of the resin mandrel 10 using a fluid or the like can be performed, and the configuration steps S4 to S6 are executed while the interior of the mandrel 10 is under pressure. In this case, even assuming that the strength of the resin mandrel 10 is low, it is possible to prevent the mandrel 10 from breaking due to the torque when each carbon fiber layer 51 to 53 is disposed on the outer peripheral surface of the mandrel 10.

[0058] Next, as Figure 7 As shown, the assembly of the mandrel 10, the first connecting member 20, the second connecting member 30, and each carbon fiber layer 51-53 is placed inside the molding device (mold) 2 (step S7). Here, the inner surface of the molding device (mold) 2 has a shape where the inner diameter is largest at the axial midpoint corresponding to the large diameter portion 11 of the mandrel 10. That is, in the closed state, the molding device 2 has a portion where the diameter of its inner circumferential surface is larger than the outer diameter of the layers on which the carbon fiber layers 51-53 are stacked, and the inner circumferential surface of the molding device 2 has a portion that separates from the outer circumferential surface of the layers on which the carbon fiber layers 51-53 are stacked within the molding device 2. Accordingly, it is possible to prevent the carbon fiber layers 51-53 from embedding into the contact surface of the mold, which is divided into multiple parts.

[0059] Next, as Figure 8 As shown, the mandrel 10 is pressurized by allowing heated fluid to flow through it within the mandrel 10 of the assembly, which is housed in the molding apparatus (mold) 2, causing the large-diameter portion 11 of the mandrel 10 to expand (step S8, expansion step). The large-diameter portion 11 of the mandrel 10 is heated and expanded by the fluid flowing within it. Furthermore, the third carbon fiber layer 53 is in close contact with the inner circumferential surface of the molding apparatus (mold) 2. Accordingly, the assembly deforms in a barrel shape that conforms to the internal shape of the molding apparatus (mold) 2. Moreover, in step S7, the heating of the mandrel 10 by the fluid can be omitted. The supply of fluid to and from the mandrel 10 is achieved through a fluid gate 2a formed on the small-diameter portion 15 side of the mandrel 10 and a hole formed in the small-diameter portion 15.

[0060] Furthermore, if the process of pressurizing the interior of the resin mandrel 10 is performed before the configuration steps S4 to S6, the interior of the mandrel 10 can be depressurized after the configuration steps S4 to S6 are completed, and steps S7 and S8 (repressurization) can be performed after depressurization. Alternatively, steps S7 and S8 (repressurization) can be performed after the configuration steps S4 to S6 without depressurizing the interior of the mandrel 10.

[0061] Next, as Figure 8As shown, resin 54 is supplied into the molding apparatus 2 to impregnate the first carbon fiber layer 51, the second carbon fiber layer 52, and the third carbon fiber layer 53 disposed on the outer peripheral surface of the mandrel 10. The resin 54 is then cured by heating the molding apparatus 2, forming a resin-containing fiber layer 50 and a resin layer 60A (step S9, molding step). The resin 54 is, for example, a thermosetting resin. In this embodiment, the mold of the molding apparatus 2 is divided into multiple parts. During the molding step, heat is applied to the assembly, and after the mold closing operation of the molding apparatus 2, a mold closing operation is further performed to apply pressure to the closed mold, thereby increasing the pressure inside the mold and promoting the curing of the resin 54. Furthermore, in this embodiment, the structure with multiple mold parts is described, thus performing the mold closing operation and the mold forming operation. However, the mold forming operation is not necessarily required. Additionally, if the mold is not divided into multiple parts, the mold closing operation and the mold forming operation are not necessarily required. Within the molding apparatus 2, a space (resin storage section 2c) is formed on the outlet side of the gate 2b through which molten resin 54 is introduced. The resin 54 introduced into the molding apparatus 2 is stored in this resin storage section 2c, located on the side of one axial end of the fiber layers 51-53. The resin 54 stored in the resin storage section 2c is moved along the axial direction of the mandrel 10 by vacuum suction from the suction port 2d, and impregnates each of the carbon fiber layers 51-53, wherein the suction port 2d is formed on the opposite side of the gate 2b (on the outer peripheral surface side of the other axial end of the fiber layers 51-53) in the arrangement direction of the fiber layers 51-53. With the resin 54 impregnated in each of the carbon fiber layers 51-53, heat is applied to the molding apparatus 2 and pressure is applied inside the molding apparatus 2, thereby forming a resin-containing fiber layer 50, and a resin layer 60A is formed at the location corresponding to the resin storage section 2c.

[0062] Next, the molded assembly, i.e., the molded body, is removed from the molding device 2 (step S10). Then, as... Figure 1 As shown, the third connecting component (short fork) 40 is installed by laser welding at the end of the molded body located on the opposite side of the mandrel 10 in the axial direction of the second connecting component 30 and not covered by the resin-containing fiber layer 50 (step S11, third connecting step).

[0063] The manufacturing method of the tube body 1A according to the first embodiment of the present invention includes a configuration step S4 to S6, an expansion step S8, and a molding step S9. In the configuration steps S4 to S6, resin-made fibers (each carbon fiber layer 51 to 53) are configured on the outer peripheral surface of the mandrel 10 by a filament winding method. After the configuration steps S4 to S6, in the expansion step S8, the mandrel 10 with the fibers configured is placed in a mold (molding device 2), and pressure is applied to the interior of the mandrel 10 with the fibers configured, thereby expanding the mandrel 10. After the expansion step S8, in the molding step S9, resin 54 is supplied into the mold, the resin impregnates the fibers, and the impregnated resin 54 is cured, thereby molding the tube body 1A.

[0064] According to the structure described above, a gap can be ensured when the mandrel 10 containing the fiber body is placed in the mold, thereby preventing the fiber body from embedding into the mold. In addition, the expansion shape of the mandrel 10 can be appropriately adjusted according to the shape inside the mold, and the amount of resin 54 in the finished tube 1A can be prevented from increasing, thereby suppressing the weight of the tube 1A.

[0065] Furthermore, according to the manufacturing method of the tube body 1A, after the forming step S9, the mandrel 10 is retained as the core material of the tube body 1A.

[0066] According to the structure, there is no need to remove the mandrel 10, and the strength and rigidity of the tube body 1A can be properly ensured by using the mandrel 10.

[0067] In addition, the manufacturing method of tube body 1A further includes a first connection step S1 before the configuration step. In the first connection step S1, the first connection component 20 is connected to one end of the mandrel 10. In the configuration steps S4 to S6, the fiber body is also disposed on the outer peripheral surface of the first connection component 20.

[0068] According to the structure described, by performing molding, the first connecting member 20 can be integrally molded with the tube body 1A, eliminating the need for a step of pressing the first connecting member 20 in after the tube body 1A is molded, thus reducing manufacturing time. Furthermore, the connection of the first connecting member 20 can be enhanced using a fiber layer (containing resin fiber layer 50) impregnated with resin 54.

[0069] In addition, in the manufacturing method of tube body 1A, the mold (forming device 2) has a space (resin storage section 2c) for storing the resin 54 injected into the mold at the connection between the mandrel 10 and the first connecting member 20. In the forming step S9, the resin 54 stored in the space is sucked out to impregnate the fiber body.

[0070] According to the structure, resin 54 can be properly impregnated between the fibers, and resin layer 60A can be properly formed by utilizing the space where resin 54 is stored.

[0071] In addition, in the manufacturing method of tube 1A, in the configuration steps S4 to S6, the fiber body is configured by a multi-feed filament winding method.

[0072] When the fiber body exhibits a crimped structure, the thickness increases at the locations where the fibers are interwoven. In contrast, according to the aforementioned structure, since the multiple fiber layers 51-53 can be a so-called non-crimped structure, the arranged fibers can appropriately follow the mandrel 10 without hindering its expansion. Furthermore, by adopting a non-crimped structure, the thickness of the resin-containing fiber layer 50 can be suppressed, shape inhomogeneity can be reduced, and localized stress can be decreased. Additionally, by adopting a non-crimped structure, the gaps between the fibers can be homogenized, thereby allowing the resin 54 to be appropriately impregnated between the fibers.

[0073] In addition, the manufacturing method of tube body 1A further includes a second connection step S3 before the configuration steps S4 to S6. In the second connection step S3, the second connection component 30 is connected to the other end of the mandrel 10. In the configuration steps S4 to S6, the fiber body is also disposed on the outer peripheral surface of the second connection component 30.

[0074] According to the structure described, by performing molding, the second connecting member 30 can be integrally molded with the tube body 1A, eliminating the need for a step of pressing the second connecting member 30 in after the tube body 1A is molded, thus reducing manufacturing time. Furthermore, the connection of the second connecting member 30 can be enhanced using a fiber layer (containing resin fiber layer 50) impregnated with resin 54.

[0075] Furthermore, in the manufacturing method of the tube body 1A, in the expansion step S8, the interior of the mandrel 10 is pressurized by allowing fluid to circulate inside the mandrel 10, and the mandrel 10 and the fiber body are heated by the heat of the fluid. According to this structure, the heating of the resin 54 can be appropriately promoted in the molding step.

[0076] <Second Implementation>

[0077] Next, the tube body and tube body manufacturing method according to the second embodiment will be described, focusing on the differences from the tube body 1A and tube body 1A manufacturing method according to the first embodiment.

[0078] like Figure 9As shown, the tube body 1B according to the second embodiment of the present invention has a resin ring 70 and a resin layer 60B instead of a resin layer 60A. In other words, the tube body 1B is composed of a resin fiber layer 50, a resin layer 60B, and a resin ring 70, and a first connecting member 20, a second connecting member 30, and a third connecting member 40 are connected to the tube body 1B. In addition, the mandrel 10 is the core material of the tube body 1B.

[0079] <Resin rings and resin layers>

[0080] The resin ring 70 is an annular component that is externally embedded on the outer peripheral surface of the large-diameter portion 21 of the first connecting member 20. The resin ring 70 is a fiber-reinforced resin ring containing reinforcing fibers (e.g., discontinuous carbon fibers) within the same material as the resin 54. The axial end of the resin ring 70 abuts against one axial end of the resin fiber layer 50. The inner diameter of the resin ring 70 is approximately equal to the outer diameter of the large-diameter portion 21 of the first connecting member 20, and the outer diameter of the resin ring 70 is smaller than the outer diameter of the resin fiber layer 50.

[0081] A resin layer 60B is disposed on the outer peripheral surface of the resin ring 70. The resin layer 60B is an annular layer. The outer diameter of the resin layer 60B is approximately equal to the outer diameter of the end of the resin-containing fiber layer 50 that abuts against the resin ring 70 and the resin layer 60B.

[0082] The resin ring 70 and the resin layer 60B cover and protect the portion of the large-diameter portion 21 of the first connecting member 20 that is exposed from the resin-containing fiber layer 50.

[0083] <Tube Manufacturing Method>

[0084] Next, use Figure 10 The flowchart is used to illustrate the manufacturing method of the tube body 1B involved in the second embodiment.

[0085] Between steps S6 and S7, the resin ring 70 is externally embedded in the portion of the large-diameter portion 21 of the first connecting member 20 that is exposed from each carbon fiber layer 51 to 53 (step S6B, external embedding step). In step S9, the resin layer 60B is formed in such a way that it covers the outer peripheral surface of the resin ring 70.

[0086] The tube body 1B according to the second embodiment of the present invention has a resin mandrel 10, a first connecting member 20, a fiber body, a resin ring 70, and a resin 60B, wherein the first connecting member 20 is connected to one end of the mandrel 10; the fiber body is disposed on the outer peripheral surface of the mandrel 10 and the first connecting member 20; the resin ring 70 is disposed on the outer peripheral surface of the first connecting member 20 exposed from the fiber body and contains the fiber body; the resin 60B is impregnated on the fiber body disposed on the outer peripheral surface of the mandrel 10 and the first connecting member 20, and forms a layer on the outer peripheral surface of the resin ring 70.

[0087] According to the structure, the difference in molding shrinkage between the resin fiber layer 50 and the resin layer 60B can be mitigated by the resin ring 70, thereby preventing cracks from forming between the resin fiber layer 50 and the resin layer 60B.

[0088] <Third Implementation Method>

[0089] Next, the tube manufacturing method according to the third embodiment of the present invention will be described, focusing on the differences from the first and second embodiments.

[0090] In the third embodiment, at least during the execution of steps S3 to S10, the mandrel 10 maintains its axial direction in a vertical position (so-called vertical state). According to this structure, even when the orientation angle of the fiber body (especially the third carbon fiber layer 53 disposed on the outermost side) is small, the displacement of the fiber body can be appropriately suppressed.

[0091] <First Variation>

[0092] like Figure 11 As shown, for the tube body 1X according to the first modified example of the present invention, in step S1, a plurality of protrusions 11a are formed on the outer peripheral surface of the large-diameter portion 11 of the mandrel 10X. The mandrel 10X having the protrusions 11a is shaped using the molding apparatus (mold) 3 used when manufacturing the resin mandrel 10X. That is, a plurality of recesses 3a corresponding to the protrusions 11a are formed on the inner peripheral surface of the molding apparatus 3 used in step S1 (see reference). Figure 12 The height of the protrusion 11a is preferably below the total height of the three carbon fiber layers 51-53 and above the total height up to the radial center of the outermost carbon fiber layer 53. The protrusion 11a of the mandrel 10X can prevent the positional displacement of each carbon fiber layer 51-53. That is, the mandrel 10X with the protrusion 11a can arrange each carbon fiber layer 51-53 at an accurate orientation angle in steps S4-S6, and can maintain the orientation angle of each carbon fiber layer 51-53 at an appropriate angle even after the mandrel 10X expands.

[0093] The manufacturing method of the tube body according to the first variation of the present invention further includes a mandrel forming step before the configuration steps S4 to S6. In the mandrel forming step, the mandrel 10X having a protrusion 11a corresponding to the recess 3a on the outer peripheral surface is formed by using a mold (forming device 3) with a recess 3a provided on the inner surface.

[0094] According to the structure, after the mandrel expands by 10X, the orientation angle of the fiber body can be maintained at an appropriate angle.

[0095] <Second Variation>

[0096] like Figure 13 As shown, in the tube 1Y according to the second variation of the present invention, the large-diameter portion 11 of the mandrel 10 and the resin-containing fiber layer 50 disposed on the outer peripheral surface of the large-diameter portion 11 are cylindrical rather than barrel-shaped. Figure 14 As shown, the inner surface of the molding device (mold) 2Y used to manufacture the tube 1Y is a cylindrical shape larger than the outer diameter of the carbon fiber layers 51-53.

[0097] The embodiments of the present invention have been described above, but the present invention is not limited to the described embodiments, and appropriate modifications can be made without departing from the spirit of the present invention. For example, it may also be a structure in which the mandrel 10 is extracted from the molded resin-containing fiber layer 50 during steps S9 and S10. Alternatively, it may be a structure in which the mandrel 10 is melted and removed by the heat of the fluid in step S8 and / or the heat of the resin 54 and the molding device (mold) 2 in step S9. It may also be possible to melt and remove the mandrel 10 by other forms of energy such as heat, electricity, or vibration.

[0098] Alternatively, in step S8, the unheated fluid can flow through the mandrel 10, and in step S9, the heated fluid can flow through the mandrel 10.

[0099] In addition, each carbon fiber layer 51 to 53 can also exhibit a so-called curled structure that is woven together with each other.

[0100] In addition, the fiber body is not limited to carbon fiber, but can be any fibrous component that can reinforce the resin layer (e.g., glass fiber, cellulose fiber, etc.).

[0101] [Explanation of reference numerals in the attached figures]

[0102] 1A, 1B, 1Y: Tube body (fiber-reinforced resin tube body); 2, 3: Molding device (mold); 2c: Resin storage section (space); 3a: Recess; 10, 10X: Mandrel; 20: First connecting component; 30: Second connecting component; 50: Resin fiber layer; 51: First carbon fiber layer; 52: Second carbon fiber layer; 53: Third carbon fiber layer; 54: Resin; 60A, 60B: Resin layer; 70: Resin ring.

Claims

1. A method for manufacturing a fiber-reinforced resin tube, characterized in that, This includes a configuration step, a repressurization step, and a molding step, among which, In the configuration step, under pressure inside the cylindrical resin component, fibers are configured on the outer circumferential surface of the resin component by a filament winding method. After the configuration step, in the repressurization step, the resin component with the fiber body is placed in the mold, and the interior of the resin component with the fiber body is pressurized, thereby repressurizing the resin component. After the repressurization step, in the molding step, resin is supplied into the mold and the resin is impregnated onto the fiber body disposed on the outer peripheral surface of the resin component, and the impregnated resin is cured, thereby forming a tube.

2. The method for manufacturing fiber-reinforced resin tubes according to claim 1, characterized in that, After the molding step, the resin component is retained as the core material of the tube.

3. The method for manufacturing fiber-reinforced resin tubes according to claim 1, characterized in that, The configuration step includes a first connection step, in which a first connection component is connected to one end of the resin component. In the configuration step, the fiber body is also disposed on the outer peripheral surface of the first connecting member.

4. The method for manufacturing a fiber-reinforced resin tube according to claim 3, characterized in that, The mold has a space at the connection between the resin component and the first connecting component to store the resin injected into the mold. In the molding step, the resin stored in the space is drawn out to impregnate the fiber body.

5. The method for manufacturing a fiber-reinforced resin tube body according to any one of claims 1 to 4, characterized in that, In the configuration step, the fiber body is configured by a multi-filament winding method.

6. The method for manufacturing a fiber-reinforced resin tube body according to any one of claims 1 to 4, characterized in that, The resin component is a mandrel, and a mandrel forming step is included before the configuration step. In this mandrel forming step, the mandrel with a protrusion corresponding to the concave portion on the outer peripheral surface is formed by using a mold with a concave portion on the inner surface.

7. The method for manufacturing a fiber-reinforced resin tube body according to any one of claims 1 to 4, characterized in that, The resin component is a mandrel. Prior to the configuration step, a second connection step is included, in which a second connection component is connected to the other end of the mandrel. In the configuration step, the fiber body is also disposed on the outer peripheral surface of the second connecting member.

8. The method for manufacturing a fiber-reinforced resin tube body according to any one of claims 1 to 4, characterized in that, The resin component is a mandrel, and in the repressurization step, the interior of the mandrel is pressurized by allowing fluid to circulate within it. The heat from the fluid is used to heat the mandrel and the fiber body.

9. The method for manufacturing a fiber-reinforced resin tube body according to any one of claims 1 to 4, characterized in that, The fiber body configured in the configuration step is a non-curled structure.

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