The poor braking performance of semi-trailers is often caused by many factors. The editor will analyze the technical personnel of Liangshan Trailer Factory from the following three factors.

Firstly, the core of the emergency brake valve braking system. One control three, the trailer is only equivalent to one outlet, meeting the gas supply needs of six slave pumps, and the two air storage cylinders do not function separately; Two controls three, the trailer is equivalent to two relay valves, with air reservoirs supplying air separately. Regardless of response time and braking compliance, the braking force meets regulatory standards.

Secondly, the material of the gas storage cylinder is poor, rusts and pollutes the pump valve, causing it to be scrapped. At present, most manufacturers on the market use iron gas storage tanks, which are prone to rusting and causing damage to pump valves. A qualified gas storage cylinder should have the functions of corrosion prevention, rust prevention, pressure stabilization, and cooling. However, most of the gas storage tanks we use do not meet the requirements. Causing severe air leakage and wear issues in the emergency relay valve and brake cylinder of the trailer.

Thirdly, differences in layout forms. One control three, the air reservoir only supplies gas in one position, and the pipe diameter is difficult to meet the requirements. When the brake pedal is activated, the response time is slow and the gas supply cannot keep up. Usually, an emergency relay valve (brake king) with excessive air supply is used, followed by a lock up during braking. The front end air supply is delayed, the middle end air pressure is too high, the braking is difficult to use, difficult to control, the braking distance is long, and it locks up. In the absence of ABS, the standard and reliable trailer braking arrangement should be a two control three layout. Trailers using a two control three layout have smoother braking and significantly reduced tire lock up compared to those using a one control three layout. Currently, in addition to well-known manufacturers such as CIMC using the standard two control three layout, some export models even have separate trailer parking brake handles. Almost without exception, other manufacturers adopt a one control three layout.