Automotive Wiring Harness Line Pre-installed On The System Design And Research

Automotive wire harness, just like the nerve center system of a person, which plays a key role in a car, its manufacture must conform to specific processes. With the development of safety, comfort, economy and emission performance, automotive wiring harness become more and more complex, while the space left get smaller and smaller. It's very important how to improve the design and manufacture of comprehensive wiring harness. Therefore, the systematic research and improvement on manufacturing processes can play an important role in economies of scale and increasing profit margin and so on. Assembling wiring harness is labor-intensive work, many processes are manual. Especially for much more complex car wiring harness, in order to avoid assembly errors and increase manufacturing efficiency, wiring harnesses are always divided into a few of small units when design the process, and then assemble them together in specific order.Shanghai Leoni Electrical System currently adopts pre-block method; the lift and drop of wires are done by hand.To meet market requirement, increase output with high quality and decrease cost,a new type of automatically pre-block method is desired to adapt to mass production, which is making progress in Europe wire harness industry, so far much less in China, but it will be adopted more and more popularly with the advancement of our Chinese industrialization.This thesis regard the pre-block system of LESS as the research object, focus on improving products quality, manufacturing efficiency, design an automated wire-lifting pre-block system, and earnestly resolve difficulties the company encountered in improving the competitiveness.This thesis covers research as below:Firstly, this paper analyze the requests of pre-block together with every factor of wire harness manufacturing for increasing the process efficiency, and then design the structure of this wiring lifting system.Secondly, according to the feature and requirement of pre-block station, choosecorresponding motor, synchronous wheel, ball bearing and guide screw etc, and design scissors-type lifting and dropping structure.Thirdly, analyze the mechanical properties of the lifting and dropping mechanism, research the force distribution inside nodes of scissors-type folding structure and the characteristics of overall deformation distribution under load. The equivalent bending rigidity of scissors-type folding structure is a function of spread angle of the structure, and is nothing to do with the length of the structure and the amount of scissors-type units. The folding structure has the same equivalent bending rigidity provided with same spread angle even though with different length and different amount of units. The equivalent axial rigidity of the structure is a function of the length and spread angle, which is reversely proportional to the square of thestructure length, when at same spread angle.Finally, use Pro/E software to create three-dimensional entity model for components, a kind of from bottom to top assembling method easily to master is adopted, in other words, to create three-dimensional entity model first and then to assemble them together.