Detection Speed Positioning
According to the technical development status of railway ultrasonic rail flaw detection vehicle in the world, we can expect the detection speed positioning according to the principles of economy and practicality. For the existing mixed passenger and freight railway, with the speed increase of railway freight cars. The ideal detection speed of flaw detection vehicle shall be at 80~100km/h. The detection of ultrasonic flaw detection vehicle will not have a great impact on the transportation order. It is convenient to be compiled with the train diagram to realize periodic flaw detection. For high-speed railway, the detection speed of 100km/h of flaw detection vehicle is still far from that of bullet train. It is impossible to arrange the detection in the passenger train flow, and to arrang at the skylight time at night. In this case, the detection speed of 80~100km/h can adapt to the maintenance management mode of high-speed railway.
Selection of Sensor
The wheel sensor has good adaptability to the line, especially in the case of slotted line or poor shape of rail head; The requirements for rail head shape of sliding shoe sensor are relatively strict. It is very difficult to use the sliding shoe sensor in winter in cold areas. In the past, it was generally believed that the main advantage of the sliding shoe sensor was higher speed, up to more than 100km/h. the wheel technology might be unable to exceed 40km/h. However, with the development of technology, Sperry company has greatly improved the detection speed by improving the structure of wheel sensor. And the speed advantage of sliding shoe sensor is gradually losing. All ultrasonic flaw detection vehicles put into use by Ultra Instrument Inc company adopt wheel sensors. All these wheel probe use for many years and have good adaptability. Therefore, the future development of railway flaw detection vehicle should still focus on wheel sensor. And the sliding shoe sensor can be a supplement to detection means.
Installation Mode
There are two main installation modes of ultrasonic sensors worldwide: Detection trolley mode and bogie truck installation mode. (1) The detection speed of bogie installation mode is slightly higher. According to the European data, the detection speed of bogie installation mode can reach 80~100km/h; The detection trolley mode in China, and the detection speed is 40~60km/h; (2) The requirements for the centering mechanism of the detection trolley mode sensor are slightly lower. The bogie truck installation mode adopts fixed gauge design, which requires high servo performance of sensor centering mechanism. (3) Each has its own advantages and disadvantages in terms of security. In the detection state, the anti derailment performance of bogie truck installation mode is better. In the running state, the detection trolley is in the detection trolley mode.
