A coil spring for a vehicle suspension according to one embodiment includes a lower end turn portion, an upper end turn portion, and a cylindrical effective portion between the lower end turn portion and the upper end turn portion. In at least one of the upper end turn portion and the lower end turn portion, a taper portion having a taper length and a taper thickness for controlling a force line of the coil spring is formed. The taper portion is formed such that the thickness is reduced in a tapered way from a thickness varying portion provided in the middle of the end turn portion toward a distal end of the wire along its length. The thickness varying portion is arranged at a position close to the force line.

The four wheel vehicle uses an electric motor (142) for driving the vehicle and a battery unit (160) for supplying electric power to the electric motor. The lower chassis (5) of the vehicle includes a pair of front side frames (10) extending linearly in a fore and aft direction with an upward slant and a progressively increasing lateral mutual spacing from a front part thereof to a rear part thereof and a plurality of cross members (14, 16, 18) connecting the front side frames to each other. The battery unit is positioned between the two front side frames such that the battery unit overlaps with the front side frames in side view. Thereby, the battery unit can be effectively protected from side impacts.

A coil spring for a vehicle suspension according to one embodiment includes a lower end turn portion, an upper end turn. portion, and a cylindrical effective portion between the lower end turn portion and the upper end turn portion. In at least one of the upper end turn portion and the lower end turn portion, a taper portion having a taper length and a taper thickness for controlling a force line of the coil spring is formed. The taper portion is formed such that the thickness is reduced in a tapered way from a thickness varying portion provided in the middle of the end turn portion toward a distal end of the wire along its length. The thickness varying portion is arranged at a position close to the force line.

A shock absorber provided with a suspension spring, the shock absorber includes a tube whose lower end portion is joined to a vehicle axle side portion provided with a tire, and a lower spring bearing that is provided on an outer circumference of the tube and supports a lower end of the suspension spring. An increased diameter part is provided on the outer circumference of the tube above the lower spring bearing, the increased diameter part having an outer diameter larger than an outer diameter of the tube.

A dual bearing strut assembly for a vehicle suspension system includes a strut with a shock absorber comprising a damper cylinder and a piston rod, and a coil spring disposed around the shock absorber. The damper cylinder may be affixed to a knuckle of a vehicle wheel assembly and the piston rod may be affixed to a top strut mount. An upper bearing assembly and a lower bearing assembly are included. The coil spring has an upper end seated to the upper bearing assembly and a lower end seated to the lower bearing assembly. The lower end of the coil spring freely rotates about the damper cylinder when the coil spring is compressed thereby reducing torque on the damper cylinder and reducing bump steer of the vehicle steering system.

A shock absorber includes a shock absorber body, a suspension spring, a spring seat, and a spring rubber seat. The seat surface of the spring rubber seat is formed inclined so as to be higher toward a distal end within a predetermined range from the distal end where a spiral portion of the suspension spring becomes apart to a side where the spiral portion of the suspension spring abuts. A concave portion surrounded by a portion abutting on the spring seat is formed on a lower side of the predetermined range in a lower part of the spring rubber seat.

The four wheel vehicle uses an electric motor (142) for driving the vehicle and a battery unit (160) for supplying electric power to the electric motor. The lower chassis (5) of the vehicle includes a pair of front side frames (10) extending linearly in a fore and aft direction with an upward slant and a progressively increasing lateral mutual spacing from a front part thereof to a rear part thereof, a pair of rear side frames (12) connected to rear ends of the respective front side frames, and extending linearly in a fore and aft direction with an upward slant from a front part thereof to a rear part thereof in continuation of the corresponding front side frames in a mutually parallel relationship, and a plurality of cross members (14, 16, 18, 20, 22) connecting the side frames to each other.

A lower spring seat 31 is mounted on a cylinder including a damper device to support a wheel-side end portion of a coil spring 30 disposed between a vehicle body and a wheel. The lower spring seat 31 includes: a mounting portion on which the wheel-side end portion of the coil spring 30 rests; and an enlarged diameter portion disposed on a side of the mounting portion opposite to the cylinder 10 and disposed between the coil spring 30 and the wheel. The mounting portion and the enlarged diameter portion are each made of a resin material.

A shock absorber provided with a suspension spring, the shock absorber includes a tube whose lower end portion is joined to a vehicle axle side portion provided with a tire, and a lower spring bearing that is provided on an outer circumference of the tube and supports a lower end of the suspension spring. An increased diameter part is provided on the outer circumference of the tube above the lower spring bearing, the increased diameter part having an outer diameter larger than an outer diameter of the tube.

A spring guide includes: a mounting portion formed so as to be depressed, the rubber sheet being fitted to the mounting portion; and a plurality of lock pieces formed to stand at an outer periphery of the mounting portion. At least one of the plurality of the first lock pieces and the second lock piece is disposed at a position that restricts deformation of a circumferential end portion of the rubber sheet to an outside in a radial direction, in a state where the rubber sheet is fitted to the mounting portion.