Abstract: A fuel system component used to supply a fuel to a fuel tank or used to discharge the fuel from the fuel tank comprises a first resin layer; and a second resin layer formed in a similar color to that of the first resin layer and configured to include a welding portion that is welded to the first resin layer and an exposed portion that is not adjacent to or in contact with the first resin layer. A belt-like portion is formed on a first resin layer-side and conically shaped surface of the exposed portion of the second resin layer at a distance from a boundary between the welding portion and the exposed portion and is configured to include at least one of a concavity and a convexity extended intermittently or continuously.

Abstract: A fuel system component used to supply a fuel to a fuel tank or used to discharge the fuel from the fuel tank comprises a first resin layer; and a second resin layer formed in a similar color to that of the first resin layer and configured to include a welding portion that is welded to the first resin layer and an exposed portion that is not adjacent to or in contact with the first resin layer. A belt-like portion is formed on a first resin layer-side surface of the exposed portion to be parallel to a boundary between the welding portion and the exposed portion and is configured to include at least one of a concave and a convex extended intermittently or continuously.

Abstract: A boot for constant-velocity universal joint includes a major-diameter fastener, a minor-diameter fastener, and a bellows. The bellows includes a first root, a first crest, a second root, a second crest, a third root, a third crest, a fourth root, a fourth crest, a fifth root and a fifth crest. The first crest, the second crest, the third crest, the fourth crest and the fifth crest have a top, respectively, and the tops of the second crest, third crest and fourth crest are disposed on an outer peripheral side with respect to a line L1, which the tops of the first crest and fifth crest make there between, in a cross section involving the central axis of the bellows.

Abstract: A smaller cylindrical portion having a clamp groove formed on an outer peripheral surface thereof has a cylindrical surface portion which extends straight in an axial direction, an inclined surface portion which extends, while being inclined, radially outwardly from an end portion of the cylindrical surface portion and a vertical wall surface portion which extends straight radially outwardly from an end portion of the inclined surface portion, the cylindrical surface portion, the inclined surface portion and the vertical wall surface portion being formed continuously sequentially in that order from a side wall surface of the clamp groove. A stress concentration on a specific location on the smaller cylindrical portion can be suppressed by virtue of the stress alleviating action of these cylindrical surface portion, the inclined surface portion and the vertical wall surface portion.

Abstract: Positioning projections for engaging recesses in an outer peripheral surface of a mating member project from an inner peripheral surface of a grommet, and the position of a minimum inside diameter portion of each positioning projection after being fitted to the mating member is offset from interference of a jointing member. In a case where the positioning projections are formed in front of a sealing projection, a larger cylindrical portion is absent around their outer peripheries. Therefore, the enlargement of the diameter of the grommet during fitting to the mating member is not restricted, resistance during fitting is alleviated, and the positioning projections are engaged in the recesses with large elastic reaction force. Hence, a click feel is excellent.

Abstract: A boot for a constant velocity universal joint includes a minor-diameter cylinder, a major-diameter cylinder, and a bellows. The major-diameter cylinder includes a sealing protrusion rim, a plurality of flanges, and positioning protrusions. The sealing protrusion rim is formed on an inner peripheral surface of the major-diameter cylinder. The flanges are disposed at intervals in a peripheral direction of the major-diameter cylinder, and extend axially outward from an opposite end surface of the major-diameter cylinder. The positioning protrusions protrude from the flanges radially toward an inner peripheral side of the major-diameter cylinder, and are to be engaged with concavities formed in an outer peripheral surface of the mating member. The boot maintains the sealing ability high, and at the same time can reduce the resistance during its fitting around a mating member, and can furthermore produce a fitting completion feeling when the fitting is completed.

Abstract: A boot for constant-velocity universal joint includes a major-diameter fastener, a minor-diameter fastener, and a bellows. The bellows includes a first root, a first crest, a second root, a second crest, a third root, a third crest, a fourth root, a fourth crest, a fifth root and a fifth crest. The first crest, the second crest, the third crest, the fourth crest and the fifth crest have a top, respectively, and the tops of the second crest, third crest and fourth crest are disposed on an outer peripheral side with respect to a line “L1,” which the tops of the first crest and fifth crest make therebetween, in a cross section involving the central axis of the bellows.

Abstract: A smaller cylindrical portion having a clamp groove formed on an outer peripheral surface thereof has a cylindrical surface portion which extends straight in an axial direction, an inclined surface portion which extends, while being inclined, radially outwardly from an end portion of the cylindrical surface portion and a vertical wall surface portion which extends straight radially outwardly from an end portion of the inclined surface portion, the cylindrical surface portion, the inclined surface portion and the vertical wall surface portion being formed continuously sequentially in that order from a side wall surface of the clamp groove. A stress concentration on a specific location on the smaller cylindrical portion can be suppressed by virtue of the stress alleviating action of these cylindrical surface portion, the inclined surface portion and the vertical wall surface portion.

Abstract: A boot for a constant velocity universal joint includes a minor-diameter cylinder, a major-diameter cylinder, and a bellows. The major-diameter cylinder includes a sealing protrusion rim, a plurality of flanges, and positioning protrusions. The sealing protrusion rim is formed on an inner peripheral surface of the major-diameter cylinder. The flanges are disposed at intervals in a peripheral direction of the major-diameter cylinder, and extend axially outward from an opposite end surface of the major-diameter cylinder. The positioning protrusions protrude from the flanges radially toward an inner peripheral side of the major-diameter cylinder, and are to be engaged with concavities formed in an outer peripheral surface of the mating member. The boot maintains the sealing ability high, and at the same time can reduce the resistance during its fitting around a mating member, and can furthermore produce a fitting completion feeling when the fitting is completed.

Abstract: In a boot including a larger cylindrical portion having a thick-walled portion and a thin-walled portion continuing smoothly in the circumferential direction on the inner peripheral surface, a ring groove coming full circle on the outer peripheral surface of the larger cylindrical portion is formed. Since shrinkage at the thick-walled portion can be prevented by the ring groove, and the ring groove is formed smoothly over the entire thick-walled portion and the thin-walled portion, there exists no varying point at which a stress generated when fastening with a fastening member suddenly changes.

Abstract: There is provided a flexible resin boot of which the noise-preventing effect lasts long and which ensures improved sealability and durability. The boot is formed from a base resin of a thermoplastic elastomer resin, and has a large port and a small port that are connected with each other via a bellows therebetween. For this, mineral oil or vegetable oil is added to the thermoplastic elastomer resin. Preferably, the thermoplastic elastomer resin is a thermoplastic polyester elastomer, and the mineral oil is process oil having an aromatic content of at most 13%. The boot is used for covering the constant velocity joint in an automobile.

Abstract: Provided is a flexible resin boot of which the noise-preventing effect lasts long and which ensures improved sealability and durability. The boot is formed from a base resin of a thermoplastic elastomer resin, and has a large port and a small port that are connected with each other via a bellows therebetween. For this, mineral oil or vegetable oil is added to the thermoplastic elastomer resin. Preferably, the thermoplastic elastomer resin is a thermoplastic polyester elastomer, and the mineral oil is process oil having an aromatic content of at most 13%. The boot is used for covering the constant velocity joint in an automobile.

Abstract: Positioning projections for engaging recesses in an outer peripheral surface of a mating member project from an inner peripheral surface of a grommet, and the position of a minimum inside diameter portion of each positioning projection after being fitted to the mating member is offset from interference of a jointing member. In a case where the positioning projections are formed in front of a sealing projection, a larger cylindrical portion is absent around their outer peripheries. Therefore, the enlargement of the diameter of the grommet during fitting to the mating member is not restricted, resistance during fitting is alleviated, and the positioning projections are engaged in the recesses with large elastic reaction force. Hence, a click feel is excellent.

Abstract: In a boot including a larger cylindrical portion having a thick-walled portion and a thin-walled portion continuing smoothly in the circumferential direction on the inner peripheral surface, a ring groove coming full circle on the outer peripheral surface of the larger cylindrical portion is formed.

Abstract: Provided is a flexible resin boot of which the noise-preventing effect lasts long and which ensures improved sealability and durability. The boot is formed from a base resin of a thermoplastic elastomer resin, and has a large port and a small port that are connected with each other via a bellows therebetween. For this, mineral oil or vegetable oil is added to the thermoplastic elastomer resin. Preferably, the thermoplastic elastomer resin is a thermoplastic polyester elastomer, and the mineral oil is process oil having an aromatic content of at most 13%. The boot is used for covering the constant velocity joint in an automobile.

Abstract: The present invention provides an apparatus for manufacturing bellows which contributes to expand the life of the resin bellows to be used for vehicles and to improve the quality of the same.

Abstract: Provided is a flexible resin boot of which the noise-preventing effect lasts long and which ensures improved sealability and durability. The boot is formed from a base resin of a thermoplastic elastomer resin, and has a large port and a small port that are connected with each other via a bellows therebetween. For this, mineral oil or vegetable oil is added to the thermoplastic elastomer resin. Preferably, the thermoplastic elastomer resin is a thermoplastic polyester elastomer, and the mineral oil is process oil having an aromatic content of at most 13%. The boot is used for covering the constant velocity joint in an automobile.