Researches On Fully Automatic Numerical Machine For The Tyre Valve Finish Machining

With the booming of car industry, demands for tyre valves are growing rapidly, as the tyre valve is an important fitting for the tyre. However, the current tyre valve manufacturing technology is quite backward, and of low automaticity. Tyre valve manufacturing is a typical labor intensive industry, whose quality stability is not easy to guarante, moreover, with the rising of the labor cost, the profit margin of the tyre valve industry is shrinking rapidly. Elevating the tyre valve manufacturing industry's degree of automation, improving pruduct quality and saving labor source are becoming urgent problems for this industry.Contrapose to this situation, a fully automatic machine for manufacturing the tyre valve is designed, which can conduct many finishing operations and is capable of manufacturing tyre valves of different sizes. First, the process flow of the tyre valve manufacturing is analyzed, the overall plan for the fully automatic machine is proposed, including functional modules of automatic loading and unloading, automatic fixing, automatic tools changing and automatic feeding. Secondly, we designed the movement control plan to meet the requirements of the functional modules. The feeding module uses stepper motor to drive ball screw, tools changing module uses stepper motor and worm and gear on for driving, and air cylinder for positioning, fixing module uses air cylinder for fixing and the loading and unloading are done by an manipulator.Thirdly, the overall structure of the fully automatic machine is designed, the feasibility of the movements of the mechanism are analyzed, the related efficiencies, the related frictions, moments and power in the feeding system and tools changing system are calculated, and the electral motor, the guide rail and the tools are selected appropriately. Finally, we designe the control system's hardware and software for the fully automatic machine, we propose to use both ARM microprocessor and DSP as the control center of the system, using DSP for the motion control module, to control the motion and manage 10, using ARM for control board managing module, to conduct man-machine interface managements, programming and communication, and we use a CPLD to generate impulses to control the stepper motor at the same time. Analysis for the processing technic of the tyre valve, analysis for the motions of the mechanisms, mechanism design, servo drive system design and numerical control system's software and hardware design are carried out in our research, and automatic loading, automatic fixing, automatic tools changing, automatic feeding are accomplished. The fully automatic machine can realize the collective processing of many finishing operations in the tyre valve manufacturing, which effectively improves the quality stability and degree of automation in the tyre valve manufacturing process.