When the tractor is connected to the semi-trailer, judging whether the center line is aligned is a key step to ensure the safety and stability of the connection. The following are specific operation methods and judgment basis:
Judgment method
1. Visual alignment:
- Back up the tractor to the front of the semi-trailer so that the center point of the saddle of the tractor is basically aligned with the towing pin of the semi-trailer.
- The center line offset of the two vehicles should be controlled below 40 mm, and the angle between the two center lines should be ≤5° when fully loaded and ≤7° when unloaded.
2. Use auxiliary tools:
- Some tractors are equipped with visual or spatial sensors to assist the driver in aligning the center line of the tractor with the semi-trailer.
- For manual operation, the driver can observe the relative position of the saddle mouth of the tractor and the towing pin of the semi-trailer to ensure that the two are in a straight line.
3. Slow reverse adjustment:
- When the tractor is backing up, it should be operated slowly, while observing the relative position of the tractor and the semi-trailer to ensure that the center line is aligned.
- If deviation is found, adjust the direction of the tractor in time until the center line is aligned.
4. Final confirmation:
- When the saddle mouth of the tractor is aligned with the semi-trailer towing pin, slowly reverse until you hear a "click" sound, indicating that the locking block has returned to its position, and the tractor and semi-trailer are successfully connected.
- Move the tractor forward slightly to check whether the connection is firm.
Notes
- Cleaning and lubrication: Before connection, make sure that there is no sand, dust or other foreign matter on the saddle of the tractor and the semi-trailer towing pin and towing slide plate, and apply enough lubricating grease.
- Height adjustment: Adjust the supporting legs of the semi-trailer so that the towing slide plate is adapted to the height of the towing saddle.
- Check the locking mechanism: After connection, check whether the locking block of the towing seat has firmly locked the towing pin.
Through the above methods and precautions, it is possible to effectively determine whether the center lines of the tractor and semi-trailer are aligned, thereby ensuring the safety and stability of the connection.