Connection of trailer towing saddle and towing pin

Connection of trailer towing saddle and towing pin

How to connect the tractor head to the trailer is a skill that every tractor driver has mastered. Especially for the driver who is engaged in the dump and hook transportation, he should pay more attention to all the details in the connection process when frequently picking up and hooking up, so as to ensure the safe completion of transportation. Now we will bring you the precautions for connecting the tractor to the trailer, so that you can safely go on the road in minutes. In fact, the connection between the tractor and the semi-trailer mainly focuses on the connection between the tractor saddle and the trailer traction pin and the connection of the electrical circuit.

1、 Connection between traction saddle and traction pin

Before connection, carefully check whether there is enough lubricating grease on the surface of the tractor saddle plate, and apply the lubricating grease evenly. Check whether there are other foreign matters on the semi-trailer's traction pin and traction sliding plate to ensure that the traction sliding plate is clean, so as to reduce accidental wear after connection. Specific operation steps:

1. Adjust the support legs to make the semi-trailer traction slide plate adapt to the height of the traction saddle. Generally, the semi-trailer traction slide plate is 1-3 cm lower than the center of the upper plane of the traction saddle of the tractor. Be careful not to be too high. Otherwise, sometimes not only can't be connected, but also can damage the traction seat, traction pin and related parts. Moreover, with the development of the whole vehicle technology, the heavy truck has an ECAS (air suspension system) control system, which can adjust the body height through the tractor, simplifying the steps of manually operating the height of the semi-trailer in the past.

2. Operate the traction seat locking mechanism to make the locking block open and free.

3. When the tractor reverses, the centerline of the tractor and trailer shall be consistent as far as possible, and the centerline offset of the two vehicles shall be limited to less than 40mm. After the saddle opening of the tractor is aligned with the towing pin, back up slowly until the "click" sound is heard, and the locking block returns, then the tractor and semi-trailer are successfully towed.

4. Check whether the traction pin is locked firmly by the traction seat locking block.

5. Move forward the tractor slightly and check whether the connection is good.

2、 Electrical circuit connection between tractor and semi-trailer

1. Connect the two air hose connectors (commonly known as handshaking) on the tractor to the two air hose connectors on the semi-trailer. At this time, the air supply pipeline of the tractor is connected to the air supply pipeline of the semi-trailer, and the control pipeline of the tractor is connected to the control pipeline of the semi-trailer (pay attention to the color of the connector: install it in the same color, do not install it reversely).

2. After the air connectors are connected with each other, unscrew the air circuit connection disconnect switch of the semi-trailer on the tractor to make it in the ventilation state, otherwise the air supply to the semi-trailer braking system cannot be provided and the braking system cannot work.

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

4. Check whether there is air leakage in the air circuit and whether the braking system works normally.

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

6. Check whether the electrodes are well connected, and confirm whether the side lights, tail lights and other lights work normally.