采用液压助力机械制动系统的履带式推土机、装载机、吊管机等工程机械,在大角度坡道上工作时,若发动机突然熄火,将使其失去液压助力,从而无法实现有效制动。本文对此种制动系统的原理、坡道制动性能进行分析,并提出相应的改进方案。1.制动系统工作原理履带式工程机械广泛采用带式制动器。带式制动器便于布置在转向离合器从动鼓上,可以采用脚踏板单独操纵(停机时),也可以采用转向离合器的操纵杆联动操纵(转向时)。带式制动器结构有单端收紧式、双端收紧式、浮式和单向增力式等4种,主要区别在于制动带端部的固定连接方式不同。国内工程机械主要采用浮式制动器和双端收紧式制动器,如图1所示。160、220、320型履带式推土机大多采用浮式制动器,其所需操纵力仅为双 Hydraulic bulldozers using mechanical brake system crawler tractors, loaders, pipelayer and other construction machinery, working on a large angle ramp, if the engine suddenly turn off, it will lose its hydraulic boost, which can not achieve effective braking. In this paper, the principle of this kind of braking system, the performance of ramp braking is analyzed, and the corresponding improvement plan is put forward. 1. Braking system works Crawler construction machinery widely used belt brakes. The belt brakes are easily mounted on the steering clutch drum, either individually by foot pedals (when stopped) or by the steering clutch lever (steering). Brake structure with a single-ended tightening, double-ended tightening, floating and one-way dynamic force, etc. 4, the main difference is that the fixed end of the brake band with different connections. Domestic construction machinery mainly uses floating brakes and double-ended tightening brakes, as shown in Figure 1. The 160,220,320 crawler dozers mostly use floating brakes, which require only double