CALCULATION OF TIME BEFORE BLOCKING WHEELS OF AN ARTICULATED VEHICLE TAKING INTO ACCOUNT LONGITUDINAL REACTION IN THE HITCH

Abstract

Wheel lock prevention is important to maintain directional stability during emergency braking. Operational experience shows that the lag of the trailer braking mechanisms in relation to the tractor is regular in nature, resulting in the folding of the road train, especially on a heterogeneous surface. One of the most important properties of modern systems to ensure the required braking efficiency while maintaining the motion stability of articulated vehicle is to estimate the time before locking the wheels. The author notes that the direction of longitudinal reaction in the coupling can be determined by the ratio of slowdown of the tractor and the trailer link, but not its value, since the inertia force is not taken into account. The longitudinal reaction in the coupling device can have a significant effect on the redistribution of gravity. The author has developed a technique for calculating the time before blocking the wheels of a articulated vehicle with a pneumatic brake system, taking into account the longitudinal reaction in the coupling device, as well as the longitudinal displacement of the saddle support device. The problem is solved only by applying the iterative method and the diagram of pressure functions known in pneumatic automation. Studies have shown that accounting for the longitudinal reaction in the fifth wheel has a greater effect on the effect of redistribution of gravity than in the hitch. To eliminate the asynchronous locking of the wheels, the author proposes to use an electro-pneumatic or electro-pneumatic-hydraulic drive. The developed technique can be used to create active safety systems.