Abstract: Disclosed is an automobile chassis, which includes a chassis main beam, a chassis cross beam and a support cross beam. The quantity of the chassis main beams is two. The two chassis main beams are arranged in parallel. A section shape of the chassis main beam is “”, and the openings of the two chassis main beams are arranged opposite. The quantity of the support cross beams is more than one. All the support cross beams are arranged between the two chassis main beams. A length direction of the support cross beam is perpendicular to a length direction of the chassis main beam. The chassis cross beam is arranged at an end of the chassis main beam, and both ends of the chassis cross beam are respectively connected and fixed with the two chassis main beams.

Abstract: A ball joint tractor with simple structure and convenient operation is disclosed. When docking is required, it will realize automatic locking, and there is no need for separate personnel to operate. Docking can be completed without getting off the vehicle. The pull ring spring plunger used in the disclosure can be directly inserted into the tractor from the outside of the tractor. When the pull ring spring plunger is damaged, it can be replaced directly without replacing the whole ball joint tractor, which improves the service efficiency of the equipment and avoids the failure of the whole ball joint tractor due to poor spring pin. In the disclosure, by placing the fixing ball in the ball joint groove for locking, the risk of automatic unlocking is avoided, and the safety performance is high and the traction effect is good.