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: 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: A hollow spring includes a steel tube in which the average of surface roughness is smaller than 10 ?m across the entire inner surface of the steel tube and/or compressive residual stress is given to the entire inner surface of the steel tube. The hollow spring may be manufactured by a step of polishing the inner surface of the steel tube by flowing a viscoelastic abrasive medium (200) within the tubular member (10), between a first opening (11) and a second opening (12) of the tubular member (10). The abrasive medium (200) may include a viscoelastic base material and a granular abrasive. The inner surface of the steel tube is polished evenly to reduce the surface roughness and/or is given compressive residual stress to increase the fatigue life of the hollow spring.

Abstract: A hollow spring includes a steel tube in which the average of surface roughness is smaller than 10 ?m across the entire inner surface of the steel tube and/or compressive residual stress is given to the entire inner surface of the steel tube. The hollow spring may be manufactured by a step of polishing the inner surface of the steel tube by flowing a viscoelastic abrasive medium (200) within the tubular member (10), between a first opening (11) and a second opening (12) of the tubular member (10). The abrasive medium (200) may include a viscoelastic base material and a granular abrasive. The inner surface of the steel tube is polished evenly to reduce the surface roughness and/or is given compressive residual stress to increase the fatigue life of the hollow spring.

Abstract: To provide a suspension coil spring capable of reducing a bowing amount and friction generated in a shock absorber, under a compressed state. A suspension coil spring (10) that is mounted between an upper seat (22) and a lower seat (24) in a strut suspension (12) for an automobile, includes an upper end turn (32) that sits on the upper seat (22); a spring active portion (11) that includes one or more coils each of which is formed such that a portion whose curvature is the largest is positioned at an automobile outer side under a mounted state; and a lower end turn (34) that sits on the lower seat (24) while substantially contacting the lower seat (24) at a single lower contacting point (P3) that is positioned at the automobile outer side with respect to a center point of the lower end turn (34).

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: To provide a suspension coil spring capable of reducing a bowing amount and friction generated in a shock absorber, under a compressed state. A suspension coil spring (10) that is mounted between an upper seat (22) and a lower seat (24) in a strut suspension (12) for an automobile, includes an upper end turn (32) that sits on the upper seat (22); a spring active portion (11) that includes one or more coils each of which is formed such that a portion whose curvature is the largest is positioned at an automobile outer side under a mounted state; and a lower end turn (34) that sits on the lower seat (24) while substantially contacting the lower seat (24) at a single lower contacting point (P3) that is positioned at the automobile outer side with respect to a center point of the lower end turn (34).

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 cover mechanism is provided for an opening and closing device, which includes a fixed plate arranged at a first housing; a moving plate arranged at a second housing; a hinge arm that is arranged between the two plates and rotates to move the moving plate between a closed position where the first and second housings overlap and an open position where surfaces of the first and second housings are substantially coplanar; and a recess formed at the second housing that prevents the hinge arm from interfering with the second housing in the open position. The cover mechanism includes a cover arranged at the moving plate that covers the recess when the moving plate is positioned at the closed position and moves from the covering position by engaging with and being urged by the rotating hinge arm; and an urging part that urges the cover toward the covering position.

Abstract: An opening/closing device includes an opening/closing mechanism which moves a movable plate between an opened position and a closed position including a hinge arm including a first axial portion rotatably connected to the fixed plate, a third axial portion rotatably connected to the movable plate, and a slide groove provided between the first axial portion and the third axial portion, and capable of moving the movable plate between the closed position and the opened position with respect to the fixed plate by being rotated around the first axial portion as a center, a link arm including a second axial portion rotatably connected to the fixed plate and a fifth axial portion slidably connected to the slide groove, and a slide arm including a fourth axial portion rotatably connected to the movable plate at an end portion and connected to the fifth axial portion at the other end portion.

Abstract: A cover mechanism is provided for an opening and closing device, which includes a fixed plate arranged at a first housing; a moving plate arranged at a second housing; a hinge arm that is arranged between the two plates and rotates to move the moving plate between a closed position where the first and second housings overlap and an open position where surfaces of the first and second housings are substantially coplanar; and a recess formed at the second housing that prevents the hinge arm from interfering with the second housing in the open position. The cover mechanism includes a cover arranged at the moving plate that covers the recess when the moving plate is positioned at the closed position and moves from the covering position by engaging with and being urged by the rotating hinge arm; and an urging part that urges the cover toward the covering position.

Abstract: An opening/closing device includes a fixed plate, a moving plate movable relative to the fixed plate, a slide plate formed having a groove, a hinge including a first shaft connected to the fixed plate, a third shaft connected to the moving plate, and a second shaft between the first and third shafts, and moves the moving plate between closed and open positions relative to the fixed plate, a slide arm including a fourth shaft connected to the moving plate and a fifth shaft connected slidably along the groove, and moves the moving plate between the closed and open positions, a link arm having one end connected to the second shaft and the other to the fifth shaft. The fifth shaft slides inside the groove as the link arm moves along with the moving of the hinge when the moving plate is moved between the closed and open positions.

Abstract: A cover mechanism is provided for an opening and closing device, which includes a fixed plate arranged at a first housing; a moving plate arranged at a second housing; a hinge arm that is arranged between the two plates and rotates to move the moving plate between a closed position where the first and second housings overlap and an open position where surfaces of the first and second housings are substantially coplanar; and a recess formed at the second housing that prevents the hinge arm from interfering with the second housing in the open position. The cover mechanism includes a cover arranged at the moving plate that covers the recess when the moving plate is positioned at the closed position and moves from the covering position by engaging with and being urged by the rotating hinge arm; and an urging part that urges the cover toward the covering position.

Abstract: An opening/closing device includes an opening/closing mechanism which moves a movable plate between an opened position and a closed position including a hinge arm including a first axial portion rotatably connected to the fixed plate, a third axial portion rotatably connected to the movable plate, and a slide groove provided between the first axial portion and the third axial portion, and capable of moving the movable plate between the closed position and the opened position with respect to the fixed plate by being rotated around the first axial portion as a center, a link arm including a second axial portion rotatably connected to the fixed plate and a fifth axial portion slidably connected to the slide groove, and a slide arm including a fourth axial portion rotatably connected to the movable plate at an end portion and connected to the fifth axial portion at the other end portion.

Abstract: The present invention relates to an opening/closing device including a fixed plate, a moving plate that can be moved relative to the fixed plate, a slide plate that is formed having a slide groove, a hinge arm including a first shaft part rotatably connected to the fixed plate, a third shaft part rotatably connected to the moving plate, and a second shaft part provided between the first shaft part and the third shaft part, and configured to move the moving plate between a closed position and an open position relative to the fixed plate by centrally rotating about the first shaft part, a slide arm including a fourth shaft part rotatably connected to the moving plate and a fifth shaft part connected slidably along the slide groove of the slide plate, and configured to move the moving plate between the closed position and the open position relative to the fixed plate by rotating about the fourth shaft part, a link arm having one end part connected to the second shaft part and another end part connected to the fi