PURPOSE: To make it possible to measure the local abrasion of a wheel in the circumferential direction automatically under the wheel running state by transmitting an ultrasonic wave into a rail, receiving the reflected wave from the contact point between the rail and the wheel, and measuring the distance to the wheel contact point at each position.
CONSTITUTION: The reciprocal propagating time T of an ultrasonic wave in a rail between a probe 1 and each of wheel contact points 2a - 2d becomes the relationship T = 2X/V (X is the distance between the probe 1 and each of the contact points 2a - 2d, and V is a sound speed). The distances to the contact points 2a - 2d can be measured based on the propagating time T. The sound part of the wheel 6 without local abrasion is in continuously contact with the rail 2, and the running distance of the wheel 6 and the positions of the contact points 2a - 2d agree. When the flat-shaped local abrasion as shown by the contact points 2b - 2d is present in the circumferential direction, the wheel 6 comes into contact with the rail 2 only intermittently. The change in distance of the contact part is very sudden in comparison with the sound part. Therefore, in a local-wheel-abrasion operating and outputting part 5, the distance change of the contact parts 2a - 2d due to the wheel running is compared with the sound part. The wheel running section which is different by the value exceeding a predetermined range or more is computed and outputted as the circumferential distance of the local abrasion.
ICHIKAWA HIROSHI
MORITA NORITAKA
