Innovative Structure Design Of The Pneumatic Airless Spray Machine

As world economy increases and technology improves,coating industry develops rapidly in the aspect of mechanization,automation and serialization.The original hand-painting has been far from satisfying the development of modern industry.Since Airless spray machine has the characteristics of high production efficiency,low mist,coating quality and so on,it was widely used in such industries as ship building,container,steel structure,the external walls of buildings, large pipes.In this paper,we focus on the Pneumatic Airless Spray Machine,supported by national science foundation Method for Product Creative Design Based on patented Knowledge Mining (Granted No.50675197) and China National Hi-tech R&D Program(863 Program) full life-cycle modeling and its solution Research based on Latent feature model(Granted No.2008AA04Z114). The Pneumatic Airless Spray Machine comprises two key components,The first one is pneumatic pump which provide power for the piston pump,and the key component of pneumatic pump is the pneumatic reversing device.The second one is piston pump which works for drawing and releasing the paint,and the key of piston pump application is to diminish its pulsating Main research contents are as follows:1.Analyzing the functional structure of the Pneumatic Airless Spray Machine,for the problems of reversing of the pneumatic pump and ripple of the dope,propose the improved structural solution of the structure in the innovation method based on patents which including the improvements of the reversing device and structure of weakening the ripple of dope.2.Improvement of reversing device1) Analyzing two kinds of gas-reversing device widely used in current.Since the reversing valve and pilot valve of the valve-type reversing device needs high precision machining,high cost and is easy to wear and slider-type reversing device exists the shortcomings of reversing noisy.In this paper,design the improved slider-type reversing device based on the structural of the existing slider-type reversing device.Change the move direction of the slider for the reversing acting from original vertical to be horizontal by the wedge-shaped surface on improved slide,the reversing rod and the reset spring on the slide.The advantage of the improved reversing device is simple, reliable and low noise. 2) Design the structural of the reversing spring,the supporting spring,the reset spring, reversing rod,reversing slide,rod ventilation valves and other corresponding parts,especially the reversing spring,the supporting spring and the reset spring.3) Make the dynamic simulation analysis for the improved structure of reversing device based on the ADAMS.Firstly,establish the three-dimensional model for the improved structure in the pro\e environment.Secondly,add constraint vice to the interface program of Pro/E with ADAMS.Thirdly,after importing the model in ADAMS,define constraints between parts existing collision by contact force,carry out simulation experiments after establishing spring model and loading the force.Lastly,optimize the structural parameters according to the results of the analysis.2.Improvement about weakening the ripple of the piston pump1) Add an accumulator after the piston pump.As an energy storage and conversion device, the accumulator transforms the kinetic energy of the paint to the potential energy when the kinetic energy higher than the design value,while the kinetic energy lower than the design value the accumulator transforms the potential energy to the kinetic energy for that the accumulator would weaken the flow pulse and pressure pulse.Design the effective volume,filliing pressure and other parameters of the accumulator in detail according to law of motion of the piston pump.2) Create original and improved simulation models in the FLUENT supporting modeling software GAMBIT,then import the grid into FLUENT to do simulation experiments.Observe the changes of the export flow by setting the mid-point of the exit section on the monitor.3.Experiment VerificationBuild the test platform which has the function of detecting the flow and the pressure of the paint instantaneously and drawing the graph according to the test data automatically.Test the original tructure and the improved tructure respectively on the test platform,Export both of the flow and pressure variation curve and verify the feasibility of the improvemed structure by compare the result between the original structure and the improved structure in the aspect of the export flow and the pressure curve.