Abstract: An optical axis of a headlight of a vehicle is adjusted by picturing an illuminating pattern of the headlight to appear on a screen which is disposed in front of the vehicle. A position of a center of gravity of a region above a predetermined illuminance in the illuminating pattern is obtained. A position of a stepped region in which a stepped portion of a light/dark border line of the illuminating pattern is present is obtained. A position of a point of inflection, in the stepped region, of an iso-illuminance curve having a predetermined rate of illuminance relative to an illuminance in the center of gravity is measured. The optical axis is adjusted based on this point of inflection.

Abstract: That illuminating pattern of the headlight which appears on a screen disposed in front of the vehicle is pictured. The optical axis of the headlight is adjusted based on an image of the illuminating pattern. A distribution of illuminance of the illuminating pattern along a scanning line which bridges a light portion and a dark portion of the image of the illuminating pattern is measured. A position of a reference point which serves as a reference in adjusting the optical axis is obtained from that point on the scanning line which corresponds to a crossing point of a first straight line and a second straight line. The first straight line is obtained from a portion corresponding at least to one of the light portion and the dark portion of a curve which represents the measured distribution of illuminance. The second straight line is obtained from a portion corresponding to a transient region which is positioned between the light portion and the dark portion.

Abstract: An illuminating pattern to appear on a first screen which is disposed in front of a headlight is pictured by a camera. A light-shielding panel is disposed on substantially the same plane as the first screen. A pin hole is formed in the light-shielding panel. The light to penetrate through the pin hole is illuminated via a mirror on a second screen which is on a surface behind the light-shielding panel. On the second screen there is formed an imaginary light source image which is to be formed on a reflecting light of the headlight. This image is pictured by the camera together with an illuminating pattern on the first screen. From the position of the imaginary light source image the actual position of the headlight is located, and the position of an acceptable range, within which a reference measuring point inside the illuminating pattern falls, is corrected depending on the position of the headlight so that the reference measuring point may fall within the acceptable range.

Abstract: An optical axis of a headlight is measured by disposing a lattice member in front of the headlight. The lattice member has a plurality of longitudinally elongated lattice holes which are arranged in a form of a matrix. An illuminated area and an illuminance of light beams to be transmitted through the lattice member are measured at each of illuminating regions which are divided into a form of a matrix by the lattice holes. The position of a light source of the headlight is located from an illuminating region of maximum illuminated area and a position of an optical axis of the headlight is located from an illuminating region of maximum illuminance. The optical axis is adjusted depending on the located position of the light source and the position of the optical axis such that the inclination angle of the optical axis coincides with a set inclination angle. An illuminance distribution pattern is used to judge the type of headlight during adjustment of the optical axis of the headlight.

Abstract: A method of assembling a steering assembly having a socket connected to a steering shaft via a steering joint which socket is to be serration-fitted to an input shaft of a gearbox which is mounted on a suspension assembly. The phase of the socket is measured at the time when a steering wheel is aligned in a neutral posture while the steering assembly is maintained in the same articulated condition as when the steering assembly is assembled to a car body and while the steering wheel is serration-fitted to the steering shaft of the steering assembly. The phase of the input shaft is adjusted such that the input shaft can be serration-fitted into the socket in the phase measured in the preceding step. The adjustment is performed by rotating the input shaft within an angular range corresponding to one half pitch of the serrations of the input shaft in either direction from a neutral posture in which the steering angles to the right and to the left are equal.

Abstract: A system for assembling bottom parts for vehicles, in which the bottom parts are transported to a position below a vehicle body positioned and fixed and are assembled to the vehicle body. The system includes a transporter for circulating a pallet member holding thereon bottom parts and a plurality of threaded parts for fastening the bottom parts to the vehicle body, so that the pallet member is stopped below the vehicle body. A first feeder is disposed in the vicinity of the transporter to feed the threaded parts to the pallet member. A second feeder is also disposed in the vicinity of the transporter to feed the bottom parts to the pallet member. A lifter is disposed below the vehicle body to raise the lower the pallet member relative to the vehicle body. A turning machine is also disposed below the vehicle body for turning the threaded part to fasten the bottom part to the vehicle body when the pallet member is in its raised position.

Abstract: Alignment adjustment apparatus for holding the subsidiary frame of a vehicle suspension sub-assembly and the suspension components in the same position they would assume when attached to and supporting a vehicle body includes sensors for detecting the relative position of wheel mounting members and knuckle arms thereby permitting alignment adjustment relative to previously measured locations of attaching means on a vehicle body to which the suspension sub-assembly is to be attached.