Analysis and design of the braking system of the hydraulic driving vehicle with bidirectional operation in coal mine
                                                                           CHEN Yongfeng1, GUO Peiyan2
（1.Department of Mechanical and Electrical Engineering, Shaanxi Railway Institute,Weinan 714000, China;2.Branch of Explosionproof Vehicle, CCTEG Taiyuan Research Institute, Taiyuan 030006, China）

Abstract: Aiming at the problem of underground transportation in small and mediumsized coal mines, the natural conditions of the roadway, the current transportation situation and the scope of application of the current mining vehicles were analyzed. The driving form, driving style and dimensions of the vehicles were studied and then a kind of mining vehicle that combines twoway driving and hydrostaticmechanical driving was proposed. The influence of the hydrostaticmechanical driving vehicle on the mutual hydraulic brake and the hydrostatic feedback brake, and the two sets of braking system, double loop hydraulic brake valve control systems in the front and rear cabs during the braking process were analyzed. The special double loop hydraulic brake valve and the front and rear cab control switching device were designed.The linkage of full hydraulic brake and hydrostatic feedback brake and two sets of front and rear cabs were realized. The results indicate that the vehicle can be used in the allway tunnel with a width of more than 1.8 m, which reduces the labor intensity of the workers, it shows almost the same braking performance in front and back driving operation, and there is no engine flameout in emergency braking state. The braking system performance is reliable.

Key words: mining vehicle; hydraulic driving; twoway driving; braking system;double loop hydraulic brake valve