Abstract: A method includes, providing a tubular member (10) used for a hollow spring, and applying the compressive residual stress to at least a portion of an inner surface of the steel tube by applying the compressive force to at least a portion of an outer surface of the tubular member (10) from a circumferential direction, and a fatigue life of the tubular member (10) is prolonged by applying the compressive residual stress to the inner surface of the tubular member (10). Applying the force to the outer surface of the tubular member (10) includes pressing the tubular member (10) with a die (1). The die (1) has a pressing surface (1a) shaped such that the compressive force can be applied to at least the portion of the outer surface of the tubular member (10) from the circumferential direction.

Abstract: Hinge (10) includes first case (11) having an insertion hole through which a first hinge shaft (17) is inserted and a guide groove guiding first link shaft (23), second case (12) having a first insertion hole and a second insertion hole through which second hinge shaft (19) and third hinge shaft (21) are respectively inserted and a guide groove guiding second link shaft (25), and a link mechanism that maintains intervals between first hinge shaft (17), second link shaft (25) and center shaft (27), intervals between second hinge shaft (19), first link shaft (23), and center shaft (27), and intervals between third hinge shaft (21), first link shaft (23), and center shaft (27), and a first member and a second member are supported with first case (11) and second case (12) respectively such that the first member and the second member are rotatable about a virtual rotation axis.

Abstract: A suspension coil spring that is to be installed between an upper side pedestal and a lower side pedestal of a strut type suspension for a vehicle includes a coil spring main body such that, in an installation state, an upper coil end is disposed on the upper side pedestal and a lower coil end is disposed on the lower side pedestal, the upper side pedestal and the upper coil end contact at two upper contact points, and the lower side pedestal and the lower coil end contact at one lower contact point. The two upper contact points are separated in a front-to-rear direction of the vehicle. The one lower contact point is disposed at a position that is in a direction toward outside the vehicle from a plane that passes through the two upper contact points and that is parallel to a coil central axis.

Abstract: A spring unit including a resin spring that is made of a resin, has a structure having a single beam, and has a resin spring curved part between a pair of resin spring end parts; and a metallic spring that is made of a metallic wire and has a metallic spring curved part between a pair of metallic spring end parts, wherein each of the metallic spring end parts is attached to each of the resin spring end parts, wherein, in a state where each of the metallic spring end parts is attached to each of the resin spring end parts, the resin spring and the metallic spring are positioned on a same plane and are mutually separated at parts other than the resin spring end parts and the metallic spring end parts.

Abstract: A suspension coil spring that is to be installed between an upper side pedestal and a lower side pedestal of a strut type suspension for a vehicle includes a coil spring main body such that, in an installation state, an upper coil end is disposed on the upper side pedestal and a lower coil end is disposed on the lower side pedestal, the upper side pedestal and the upper coil end contact at two upper contact points, and the lower side pedestal and the lower coil end contact at one lower contact point. The two upper contact points are separated in a front-to-rear direction of the vehicle. The one lower contact point is disposed at a position that is in a direction toward outside the vehicle from a plane that passes through the two upper contact points and that is parallel to a coil central axis.

Abstract: A spring unit includes a composite spring and a metal wire. The composite spring is formed of resin, has a single beam structure, and includes a curved part between its end parts. The metal spring is formed of a metal wire, and includes a curved part between its end parts. The end parts of the composite spring are fixed to the corresponding end parts of the metal spring, so that the composite spring and the metal spring are fixed to be positioned in the same plane. The composite spring and the metal spring engage with each other in an engagement part formed in at least one position between the curved parts and the end parts. The composite spring and the metal spring are separated in a part other than the end parts and the engagement part.

Abstract: An attaching method of attaching a film-like member shaped like a plane face to a member having a surface shaped like a curved face including a first step of determining, by an analysis, a region where stress higher than that in a case where the film-like member is shaped like the plane face is generated when the film-like member is attached to the member shaped like the curved face, a second step of forming a slit at the region where the stress higher than that in the case where the film-like member is shaped like the plane face is generated, and a third step of attaching the film-like member having the formed slit to the member having the surface shaped like the curved face.

Abstract: A curved spring includes one and another end parts configured to approach and separate relative to each other in an approaching/separating direction and plural beam parts that bend between the one end part and the other end part and extend in an extending direction. The plural beam parts are arranged in a width direction orthogonal to the approaching/separating direction. At least one combination of adjacent beam parts among combinations of the plural beam parts includes an outer side beam part having a width greater than a width of an inner side beam part in the width direction. The outer side beam part has a length less than a length of the inner side beam part in the approaching/separating direction. The one and the other end parts and at least one beam part of the plural beam parts are integrally molded on a shared plane by a synthetic resin.

Abstract: A spring unit includes a composite spring and a metal wire. The composite spring is formed of resin, has a single beam structure, and includes a curved part between its end parts. The metal spring is formed of a metal wire, and includes a curved part between its end parts. The end parts of the composite spring are fixed to the corresponding end parts of the metal spring, so that the composite spring and the metal spring are fixed to be positioned in the same plane. The composite spring and the metal spring engage with each other in an engagement part formed in at least one position between the curved parts and the end parts. The composite spring and the metal spring are separated in a part other than the end parts and the engagement part.

Abstract: A spring unit including a resin spring that is made of a resin, has a structure having a single beam, and has a resin spring curved part between a pair of resin spring end parts; and a metallic spring that is made of a metallic wire and has a metallic spring curved part between a pair of metallic spring end parts, wherein each of the metallic spring end parts is attached to each of the resin spring end parts, wherein, in a state where each of the metallic spring end parts is attached to each of the resin spring end parts, the resin spring and the metallic spring are positioned on a same plane and are mutually separated at parts other than the resin spring end parts and the metallic spring end parts.

Abstract: An attaching method of attaching a film-like member shaped like a plane face to a member having a surface shaped like a curved face including a first step of determining, by an analysis, a region where stress higher than that in a case where the film-like member is shaped like the plane face is generated when the film-like member is attached to the member shaped like the curved face, a second step of forming a slit at the region where the stress higher than that in the case where the film-like member is shaped like the plane face is generated, and a third step of attaching the film-like member having the formed slit to the member having the surface shaped like the curved face.

Abstract: A curved spring includes one and another end parts configured to approach and separate relative to each other in an approaching/separating direction and plural beam parts that bend between the one end part and the other end part and extend in an extending direction. The plural beam parts are arranged in a width direction orthogonal to the approaching/separating direction. At least one combination of adjacent beam parts among combinations of the plural beam parts includes an outer side beam part having a width greater than a width of an inner side beam part in the width direction. The outer side beam part has a length less than a length of the inner side beam part in the approaching/separating direction. The one and the other end parts and at least one beam part of the plural beam parts are integrally molded on a shared plane by a synthetic resin.