Research And Design Of Automatic Assembly System Of Saw Chain

Saw chain is an important part of forest cutting saws, and its performance affects the efficiency of sawing, fuel consumption and labor intensity directly. At home and abroad, saw chain is mostly assembled by hand, except that some companies adopt semi-automatic assembly partially. This artificial production method has the problem such as unstable assembly quality, low assembly efficiency, high cost and so on. As a result, many saw chain manufacturers are eager to possess an automatic assembly system of saw chain.Saw chain is an automatic assembly system of small parts, fast rhythm, higher accuracy, in whose development processs there are many technical problems, such as transmission, orientation, feeding, riveting and so on. The research and development of automatic assembly system of saw chain in this paper are exactly motivated by the above mentioned problems. The main contents are as follows:1) According to the design requirements, the minimum circular unit as the system’s assembly unit and the assembly process of four stations are figured out, based on the deep analysis of the structure of saw chain. In the light of the basic principles of design methodology, it is confirmed to use straightline dividing transmission, vibratory feeders, gravity feed tracks and hydraulic riveting machines as a solution.2) The design of transfer system and fixture part of the saw chain automatic assembly system is completed. On the analysis of the assembly process, the assembly parts should have X, Y, Z three motion degrees of freedom. Following this, the overall design scheme of the transfer system and fixture part is drawn up. Finally, X, Y, Z axis motion of the parts is analysed and designed.3) The design of feeding system of saw chain automatic assembly system is completed. According to the engineering practices, rising angle (?)and other main parameters of the vibratory feeders are figured out through the analysis of the vibration transmission mechanics; the feed track sections are analysed and designed to find out a way to avoid the phenomenon of card materials; with TRIZ theory, the four targeted stations’escapements are designed, referencing the claw type escapement and slide type escapement.4) The design for the layout of riveting work heads of saw chain automatic assembly system is completed. Based on the substance-field analysis theory, three different layout schemes are proposed. Considering each scheme’s feasibility and economy, the scheme of direct rivet is replaced by the scheme of indirect. Meanwhile, the throttling synchronous hydraulic loop is designed, and the hydraulic cylinders’ main structure sizes are determined.The successful development of the automatic assembly system of saw chain not only improves the assembly efficiency and quality remarkably, but also reduces worker’s labour intensity significantly, so it’s meaningful to the technology progress of enterprises.