Brief introduction of semi-trailer brake system design and trouble shooting (two)

The important role of emergency relay valve

Emergency relay valve is the core component of the whole trailer brake system, it is compatible with relay valve, distribution valve, one-way valve, quick release valve functions, equipped with emergency relay valve trailer, greatly shorten the trailer brake lag time. In fact, the emergency brake valve functions more than these, it has three major functions:

1. the normal brake working brake state

This is the most direct function we feel, when the brake pedal, Control Line "1"air, emergency relay valve"5"control"6"cylinder to"4"brake sub-pump air supply brake force; when the brake pedal is released, the emergency relay valve quickly releases the pump Compressed air and quickly releases the brake state

2. Feedback braking state during inflation

When the trailer is parked for a long time and the brake system has no air pressure, the trailer parking brake system (cut-off air brake) acts. When the tractor inflates the air storage cylinder of trailer "6" through“2”air supply lines, the emergency relay valve is in the safe braking state. The“5”emergency relay valve sends the Compressed air into each “4”brake sub-pump. When the air pressure of the trailer “6” cylinder rises to 4.5 bar, the safety condition is lifted. This function is referred to as the feedback brake function, the brake sub-pump produces the brake force in the state of inflation, which is a safety protection function.

3.Automatic braking state in case of emergency gas cut-off

When the gas supply line is damaged accidentally, the Compressed air in the air storage cylinder of the trailer 6 enters the 4-brake sub-pump through the 5-emergency relay valve and automatically performs the braking measures to ensure the safety of the vehicle in an emergency. When the tractor stops and needs to disconnect the air supply line of trailer 2, the trailer brake sub-pump can also be seen to work on the same principle