Method for modeling and designing a helical spring

A computer-implemented method for modeling and designing a helical spring, particularly a helical spring used in a suspension of a motor vehicle, 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:

• establishing a start point in a computer for the modeling and designing the helical spring by setting a twist angle of the start point of the top end turn (1) as a twist angle of zero to provide a twist angular position (θ1) of the start point of the top transition turn (2), a twist angular position (θ2) of the end point of the top transition turn (2), a twist angular position (θ3) of the start point of the bottom transition turn (4), and a twist angular position (θ4) of the end point of the bottom transition turn (2);
• utilizing a first interpolation in the computer to determine a radius (R3) of the active turn (3) on the basis of a radius (R30) of the active turn (3) in a free state of the helical spring, a longitudinal overall length (L0) of the helical spring in the free state, a longitudinal overall length (Ls) of the helical spring in a tightly compressed state, a z-coordinate position (Z200) of the top transition turn (2) at the twist angle of the end point, a z-coordinate position (Z300) of the bottom transition turn (4) at the twist angle of the start point, and a diameter of the helical spring's helical wire, wherein the active turn (3) is as a function of a longitudinal overall length (L) of the helical spring;
• utilizing the first interpolation in the computer to determine the z-coordinate position (Z3 (θ, L)) of the active turn (3), 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) on the basis of the above parameters, a radius (R1) of the top end turn (1) and a radius (R5) of the bottom end turn (5), and under the premise that the stiffness of the helical spring is the linear superposition of the stiffnesses of the top end, top transition, active, bottom transition, and bottom end turns, 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 a twist angle (0) of the helical spring;
• and
• making the designed helical spring for use in the suspension of the motor vehicle.