Precautions for connecting the tow head to the trailer

1. The connection between the traction saddle and the traction pin Before connecting, carefully check whether there is enough lubricating grease on the saddle plate of the tractor, and apply the lubricating grease evenly. Check the traction pins of the semi-trailer and whether there are other foreign objects on the traction skateboard, and ensure the cleanliness of the traction skateboard, so as to ensure that accidental wear is reduced after connection.

Specific steps:

1. Adjust the support legs to make the semi-trailer traction skateboard fit the height of the traction saddle. Generally, the semi-trailer traction skateboard is 1-3 cm lower than the center position of the upper plane of the tractor traction saddle. Be careful not to be too high. Otherwise, sometimes it will not only fail to connect, but also damage the traction seat, traction pin and related parts. And with the development of vehicle technology, high-end heavy trucks have ECAS (Air Suspension System) control system, which can adjust the height of the body through the tractor, which simplifies the steps of manually operating the height of semi-trailers in the past and is more efficient.

2. Operate the locking mechanism of the traction seat to make the locking block open and become a free state. .

3. When the tractor reverses, try to keep the center line of the tractor and semi-trailer consistent, and the offset of the center line of the two vehicles is limited to less than 40mm. Align the saddle of the tractor with the traction pin and slowly reverse the vehicle until a "click" sound is heard, and when the locking block returns, the tractor and the semi-trailer are successfully towed. .

4. Check whether the locking block of the traction seat locks the traction pin and whether it is locked firmly.

5. Move the tractor forward a little to check if the connection is good. .

Second, the electrical circuit connection between the tractor and the semi-trailer

1. Connect the two gas pipe joints (commonly known as handshake) on the tractor to the two gas pipe joints on the semi-trailer. At this time, the air supply line of the tractor is connected with the air supply line of the semi-trailer, and the control line of the tractor is connected with the control line of the semi-trailer (pay attention to the color of the joint: the same color is installed, do not install it in reverse). .

2. After the air joints are connected to each other, unscrew the semi-trailer air circuit connection disconnect switch on the tractor to make it in a ventilated state, otherwise it will not be able to supply air to the semi-trailer braking system, and the braking system will not work. .

3. Start the engine, observe the air pressure gauge in the cab, and increase the pressure in the air tank of the tractor and semi-trailer to the specified pressure. .

4. Check whether there is air leakage in the air circuit, and check whether the braking system is working normally. .

5. Insert the cable connection plug of the tractor into the seven-hole socket on the front end of the semi-trailer until it is locked on the block of the seven-hole latch. .

6. Check whether the electrodes are well connected, and confirm whether the lights such as side lights and tail lights work normally. After hanging up the semi-trailer, confirm that the instruments are working normally, and then you can start driving!