Suspension coil spring

A suspension coil spring configured to be interposed between an upper seat (22) and a lower seat (24) in a strut type suspension device (12) for a vehicle, the suspension coil spring consisting of:

• in a free state a coil axis (AC) bent in a V shape at a bending point (PB), the bending point (PB) coincident with the coil axis (AC) at a portion of the suspension coil spring (10) that corresponds to an end turn portion from a spring terminal for a predetermined number of turns, wherein the number of turns is a positive real number and wherein the bending point is further positioned to intersect an imaginary coil axis (AI) defined as a straight line that corresponds to an un-bent axis;
• each of an upper end turn center (CU) and a lower end turn center (CL) which intersect the coil axis (AC) and at least one of the upper end turn center (CU) and the lower end turn center (CL) is eccentric in a predetermined eccentric amount (VU, VL) in a predetermined eccentric direction that is perpendicular with respect to the imaginary coil axis (AI);
• an upper end turn portion (32) set such that an upper seating surface (38) intersects substantially perpendicularly with respect to the imaginary coil axis (AI);
• a lower end turn portion (34) set such that a lower seating surface (40) intersects substantially perpendicularly with respect to the imaginary coil axis (AI), and at least one of the upper seating surface (38) and the lower seating surface (40) does not intersect perpendicularly with respect to the coil axis (AC),
• wherein the upper end turn portion (32), the lower end turn portion (34) and the turns located in between are configured such that the suspension coil spring (10) is elastically deformed between the spring seats (22) and (24) in a compressed direction and a flexed direction, a compressive reaction force and a transverse reaction force being applied to the spring seats (22) and (24), and wherein a spring reaction force of the suspension coil spring (10) is a composite force of the compressive reaction force and the transverse reaction force, and a magnitude of the transverse reaction force, which is applied from the suspension coil spring (10) to the spring seats (22) and (24), is determined by the upper eccentric amount (VU) and the lower eccentric amount (VL), and a direction of the transverse reaction force is determined in one of a positive direction and a negative direction on a coordinate axis.