A coil spring includes an elongated body (10) formed by a plurality of continuous coils (21, 31), and the body (10) includes an upper section (20) and a lower section (30), wherein pitches (22) and coil angles (23) of the coils (21) in the upper section (20) are generally consistent to form an upright profile (24) for the upper section (20), and wherein pitches (32) and coil angles (33) of two or more coils (31) at a free end of the lower section (30) is differed from the pitches (22) and the coil angles (23) of the coils (21) in the upper section (20) to form a gradually curved profile (34) for the lower section (30).

In a case where the coating film is confirmed to remain in a third step, at least one or more of conditions of the shot peening treatment including a propelling speed of the shot medium, a propelling time of the shot medium, a material of the shot medium, and an average particle diameter of the shot medium are changed and the second step and the third step are repeated until the coating film does not remain In a case where the coating film is not confirmed to remain in the third step, the condition of the shot peening treatment in the second step in which the coil spring is obtained with no remaining coating film is determined as the propelling condition for the shot medium.

A method of manufacturing a hollow coil spring which is made of a hollow wire in which a terminal sealed portion is formed on an end portion of the wire. The terminal sealed portion has a rotationally symmetric shape in which an axis passing through the center of the wire is the symmetric axis. The hollow coil spring includes an end wall portion, and an end face arc-shaped curved surface. The end wall portion includes an end face perpendicular to the axis. A distal-end-center closure portion is formed on the axis at the center of the end wall portion. A spring seat includes a base member and a sheet member. An end turn portion of the hollow coil spring is in contact with the sheet member. The end face of the end turn portion is opposed to a stopper wall of the spring seat.

The invention proposes a method of supplying with hydraulic fluid a hydraulic motor (2) of a drive wheel supporting a vehicle by means of a cylinder-type suspension system (1). The hydraulic fluid passes through a feed duct (25) extending longitudinally through a cylinder (3) of the cylinder-type suspension system (1). The invention also relates to the use thereof in order to eliminate the need for hoses.

A suspension coil spring, when assembled to a suspension device, in which a spring reaction axis (AR) is positioned coincident with or sufficiently close to a load input axis (AA), and the design and manufacture of coil springs are facilitated. Namely, a suspension coil spring (10) in a free state is formed so that a coil axis (AC) is bent in V-shape at bend point (PB) and the distance from the end turn center (CU) of the upper seating surface (38) to an imaginary coil axis (AI) is an upper inclination amount (V.sub.U), and the distance from the end turn center (CL) to the imaginary coil axis (AI) is a lower inclination amount (V.sub.L). When the suspension coil spring (10) is interposed between spring seats (22, 24) in the suspension device and compressed along a strut axis, the spring reaction AR axis of the suspension coil spring (10) is inclined and offset with respect to the imaginary coil axis (AL) according to the inclination amounts (V.sub.U, V.sub.L).

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.

A method of manufacturing a hollow coil spring which is made of a hollow wire in which a terminal sealed portion is formed on an end portion of the wire. The terminal sealed portion has a rotationally symmetric shape in which an axis passing through the center of the wire is the symmetric axis. The hollow coil spring includes an end wall portion, and an end face arc-shaped curved surface. The end wall portion includes an end face perpendicular to the axis. A distal-end-center closure portion is formed on the axis at the center of the end wall portion. A spring seat includes a base member and a sheet member. An end turn portion of the hollow coil spring is in contact with the sheet member. The end face of the end turn portion is opposed to a stopper wall of the spring seat.

A method of modeling and designing a helical spring, the helical spring including a top end turn (1), a top transition turn (2), an active turn (3), a bottom transition turn (4), and a bottom end turn (5) from top to bottom, the method including: utilizing first interpolation to determine the radius (R3) of the active turn (3), wherein the active turn (3) is as a function of the longitudinal overall length (L) of the helical spring; and utilizing second interpolation to determine the radius (R2) and the z-coordinate position (Z2) of the top transition turn (2) and the radius (R2) and the z-coordinate position (Z2) of the bottom transition turn (4), wherein each of the z-coordinate position (Z3(θ, L)) of the active turn (3), the radius (R2) and the z-coordinate position (Z2) of the top transition turn (2) and the radius (R2), and the z-coordinate position (Z2) of the bottom transition turn (4) is as a function of the longitudinal overall length (L) and the twist angle (θ) of the helical spring.

Independent wheel suspensions for a motor vehicle are described herein. An example independent wheel suspension includes a link to be pivotably coupled to a vehicle body of the motor vehicle via a first flexible pivot bearing and a second flexible pivot bearing. The first and second flexible pivot bearings form a pivoting axis. The link has a wheel attachment point to which a vehicle wheel is to be coupled. The example independent wheel suspension also includes a spring to be disposed between the link and the vehicle body. The spring is configured to produce a force component on the link that is directed outward along a transverse axis of the motor vehicle and that increases during compression.

A hollow coil spring is made of a hollow wire in which a terminal sealed portion is formed on an end portion of the wire. The terminal sealed portion has a rotationally symmetric shape in which an axis passing through the center of the wire is the symmetric axis. The hollow coil spring includes an end wall portion, and an end face arc-shaped curved surface. The end wall portion includes an end face perpendicular to the axis. A distal-end-center closure portion is formed on the axis at the center of the end wall portion. A spring seat includes a base member and a sheet member. An end turn portion of the hollow coil spring is in contact with the sheet member. The end face of the end turn portion is opposed to a stopper wall of the spring seat.