Abstract: Two flat fiber bundles of non-twisted filaments are arranged in an overlapped relationship or in a parallel and adjoining relationship, and held by a gripper at two points spaced apart from each other in the filament-extending direction. Compressed air is injected from a nozzle to the overlapped portion of the fiber bundles between the holding points at a plurality of positions arranged in the direction transverse to the filament-extending direction to cause the adjacent filaments to be entangled. The nozzle is moved across the fiber bundles while injecting air. Filaments are thus opened and rotated by the injected air, and thus entangled. A fiber bundle joining apparatus includes support sections and a receiving section provided in a base, a gripper cooperating with the support sections to grip overlapped ends of fiber bundles therebetween, a nozzle, and a regulating member to temporarily hold the fiber bundles and to allow the lower fiber bundle to be slackened.

Abstract: A FRP pipe comprising a helix winding layer formed by cylindrically winding reinforced fibers, wherein the helix winding layer has two ends and an axis and the reinforced fibers forming the helix winding layers are wound at an angle relative to the axis and hoop winding layers formed at each end of the helix winding layer by winding reinforced fibers at each end wherein the hoop layer are formed from the same continuous reinforced fibers, and the continuous reinforced fibers forming the hoop winding layers extend between the ends at an angle that is the same as the angle of the reinforced fibers forming the helix winding layer.

Abstract: Two flat fiber bundles of non-twisted filaments are arranged in an overlapped relationship or in a parallel and adjoining relationship, and held by a gripper at two points spaced apart from each other in the filament-extending direction. Compressed air is injected from a nozzle to the overlapped portion of the fiber bundles between the holding points at a plurality of positions arranged in the direction transverse to the filament-extending direction to cause the adjacent filaments to be entangled. The nozzle is moved across the fiber bundles while injecting air. Filaments are thus opened and rotated by the injected air, and thus entangled. A fiber bundle joining apparatus includes support sections and a receiving section provided in a base, a gripper cooperating with the support sections to grip overlapped ends of fiber bundles therebetween, a nozzle, and a regulating member to temporarily hold the fiber bundles and to allow the lower fiber bundle to be slackened.

Abstract: A propeller shaft 1 comprising a shaft main body 10 and a yoke 20 which is mounted to the shaft main body 10 with a serrated inserting portion 21 thereof being press fitted into an inner circumferential surface of the shaft main body 10 is constructed such that serration fit-in grooves 11 having extending portions 11b into which serration teeth 22 travel when the yoke 20 is allowed to sink into the shaft main body 10 are formed in advance in the inner circumferential surface of the shaft main body 10. A method for producing the propeller shaft 1 comprises a yoke press fitting step and a yoke withdrawing step that is to be performed after the former step.

Abstract: A filament winding apparatus winds yarn impregnated with resin around the surface of a mandrel with a guide member that moves back and forth axially. Yarn winding is initiated while an end of the yarn is held by a holding device provided in a relatively rotatable manner on a rotary shaft. After winding is started, the yarn extending from the mandrel to the holding device is cut. When winding is finished, the yarn is held with the holding device and the yarn is cut between the mandrel and the holding device with a yarn cutting device.

Abstract: Two flat fiber bundles of non-twisted filaments are arranged in an overlapped relationship or in a parallel and adjoining relationship, and held by a gripper at two points spaced apart from each other in the filament-extending direction. Compressed air is injected from a nozzle to the overlapped portion of the fiber bundles between the holding points at a plurality of positions arranged in the direction transverse to the filament-extending direction to cause the adjacent filaments to be entangled. The nozzle is moved across the fiber bundles while injecting air. Filaments are thus opened and rotated by the injected air, and thus entangled. A fiber bundle joining apparatus includes support sections and a receiving section provided in a base, a gripper cooperating with the support sections to grip overlapped ends of fiber bundles therebetween, a nozzle, and a regulating member to temporarily hold the fiber bundles and to allow the lower fiber bundle to be slackened.

Abstract: A filament winding apparatus that efficiently fabricates an FRP pipe, which includes a helix layer and separated hoop layers. The apparatus winds fiber strands around a rotating mandrel and includes a winding unit moved reciprocally along an axial direction of the mandrel. The unit includes a helix winding head, which simultaneously winds fiber strands around the mandrel, a hoop winding head, which winds a fiber strand around the mandrel, a helix fiber spreading portion, which spreads the fiber strands wound around the wound subject by the helix winding head, and a hoop fiber spreading portion, which spreads the fiber strand wound around the mandrel by the hoop winding head.

Abstract: A step portion is provided between a serration portion of a metal-made yoke and a leading end portion thereof. During pressure insertion and joining, an FRP-made cylinder is pressure-inserted to the serration portion in a state that the circularity is enhanced by the step portion. Consequently, the pressure insertion and joining is carried out while making the depth of cut grooves uniform, thereby enhancing concentricity (joining accuracy).

Abstract: A propeller shaft 1 comprising a shaft main body 10 and a yoke 20 which is mounted to the shaft main body 10 with a serrated inserting portion 21 thereof being press fitted into an inner circumferential surface of the shaft main body 10 is constructed such that serration fit-in grooves 11 having extending portions 11b into which serration teeth 22 travel when the yoke 20 is allowed to sink into the shaft main body 10 are formed in advance in the inner circumferential surface of the shaft main body 10. A method for producing the propeller shaft 1 comprises a yoke press fitting step and a yoke withdrawing step that is to be performed after the former step.

Abstract: A fiber-reinforced plastic pipe has a joint section formed in one end. The joint section is coupled to another member. The pipe includes a helical layer formed with a fiber. The fiber is wound at a winding angle that is equal to or less than forty-five degrees. The fiber volume fraction of the joint section is lower than the fiber volume fraction of the remainder of the pipe.

Abstract: A filament winding apparatus winds yarn impregnated with resin around the surface of a mandrel with a guide member that moves back and forth axially. Yarn winding is initiated while an end of the yarn is held by a holding device provided in a relatively rotatable manner on a rotary shaft. After winding is started, the yarn extending from the mandrel to the holding device is cut. When winding is finished, the yarn is held with the holding device and the yarn is cut between the mandrel and the holding device with a yarn cutting device.

Abstract: A drive shaft having a body section and a yoke section formed with at least one end of the body section. A hole is formed in the yoke section. The body section and yoke section are integrally made of a fiber reinforced composite material including a filament and a plastic adhered to the filament. The shaft comprises a plurality of shaft fiber layers forming the body section. Each shaft fiber layer includes a plurality of shaft fiber elements being arranged at predetermined intervals. A plurality of yoke fiber layers form the yoke section. Each yoke fiber layer includes a plurality of yoke fiber elements. Each yoke fiber element has ends connected to each shaft fiber element. Each yoke fiber element has either a closed loop arrangement (CLA) or an open loop arrangement (OLA). The CLA is defined by the yoke fiber elements forming closed loops around the hole. The OLA is defined by the yoke fiber elements forming open loops around the hole.

Abstract: An energy absorber is formed of a fiber reinforced composite into a cylinder having a plurality of portions so that the thickness of the body gradually increases in at least two stages in the axial direction. Reinforcing fiber is wound around at least in a circumferential direction of the body and is impregnated with a resin. The body of the energy absorber has a thin portion continuous to a first end. The end surface of the first end has an area equal to or smaller than 2/3 of the cross-sectional area of the thin portion the vicinity of the junction between the thin portion and the portion adjacent which is thicker than that thin portion. That cross-sectional area of the thin portion continuously increases to the middle of the thin portion from the first end side. The energy absorber is used in a state where impact is applied from the axial direction of the body.