关键词: 四轮定位；后轮前束；公差调整；6 Sigma

Abstract: Four-wheel alignment is a significant parameter to ensure that the vehicle has good driving performance. Testing and adjusting it effectively has important implications for improving the safety and economy of vehicles. This paper mainly analyzes the parameters of rear axle toe-in in the four-wheel alignment. In this paper, the parameters of rear axle toe-in were adjusted at the supplier first, then were tested at the vehicle factory. Due to the high adjustment rate of the rear wheel toe-in in the factory, the workload of the workers is greatly increased. This paper used 6 Sigma method to solve the actual issues of rear wheel toe-in. Through checking and analyzing the process from supplier to vehicle factory, and a series of definition, measurement, analysis, improvement and control, the several parameters causing problems were found out step by step. After improving and controlling the parameters, the adjustment rate of rear wheel toe-in was reduced, and the problem of low efficiency caused by similar reasons was reduced in the future.

Key words: Four wheel alignment; Rear axle toe-in; Tolerance adjustment; 6 Sigma