Study On Preparation Technology Of Spray Nozzle Diaphragm Of Damping Adhesive

The vibration and noise generated during the driving of the vehicle are important factors affecting driving comfort and safety,and are also the main source of noise pollution.Therefore,noise reduction of vehicles is an inevitable process of vehicle development.Under the industrial production conditions,the traditional solid damping rubber sheet is easy to cause environmental pollution because it contains asphalt and other components.In addition,after high temperature or long-term use,it ages and causes performance degradation.At present,a liquid sprayable damping rubber has been developed at home and abroad,and its liquid state can make the damping rubber use performance more stable and environmentally friendly,and significantly improve its sound insulation and noise reduction effect.The liquid sprayable damping glue can be automatically sprayed using robotic equipment.The excellent mechanical properties and precise dimensional design of the spray gun head diaphragm are the key to the application of liquid sprayable damping rubber.According to the use requirements of the damping rubber spray gun diaphragm,W18Cr4V high speed steel and WC-8%Co cemented carbide are selected as the diaphragm substrate.A nitride film of Ti-Al-Zr-Cr system and Ti-Al-Zr-Nb system is selected for surface coating of the diaphragm substrate to improve the mechanical properties of the diaphragm.Design the profile size of the diaphragm to improve the performance of the diaphragm.Firstly,based on the requirements of high hardness and high wear resistance of the diaphragm,W18Cr4V high speed steel and WC-8%Co cemented carbide material were used as the diaphragm substrate,and hardness testing and profile size analysis were performed.The hardness of W18Cr4V high speed steel reaches 750HV_0.025,and the hardness of WC-8%Co cemented carbide reaches 1160HV_0.025.Using the secondary imaging technology,the dimensional accuracy of the diaphragm substrate is up to0.006mm,which meets the accuracy requirements of the diaphragm substrate of less than 0.01mm.Secondly,the Cr target and the Nb target are respectively combined with the Ti-Al-Zr alloy target by a multi-arc ion plating technique to perform coating.CrN/?Ti,Al,Zr,Cr?N and NbN/?Ti,Al,Zr,Nb?N films were deposited on W18Cr4V high speed steel and WC-8%Co cemented carbide diaphragm substrate.And the film composition,phase structure,hardness,film-based bonding force and wear resistance analysis.It is found that CrN/?Ti,Al,Zr,Cr?N and NbN/?Ti,Al,Zr,Nb?N double-layer films all have a TiN lattice structure.The hardness of CrN/?Ti,Al,Zr,Cr?N double-layer film on W18Cr4V and WC-8%Co substrates can reach 3400±100HV_0.01,3900±100HV_0.01,respectively.The film-based bonding force can reach 190N and 200N respectively,and the wear resistance coefficient is between 0.33⁰.43 and 0.3⁰.38,respectively.The hardness of NbN/?Ti,Al,Zr,Nb?N double-layer film on W18Cr4V and WC-8%Co substrates can reach 3300±100HV_0.01,3800±100HV_0.01,respectively.The film-based bonding force can reach 190N and 200N respectively,and the wear resistance coefficient is between 0.35⁰.45 and 0.3⁰.4,respectively.Finally,the contour opening size of the damping rubber spray head diaphragm is the basis for ensuring the width and thickness of the damping glue strip after spraying.The diaphragm opening size was designed,and a diaphragm having an opening width of21²4mm?upper diaphragm?/26.3²9.5mm?lower diaphragm?and an opening angle of 78⁸5°?upper diaphragm?/94¹07°?lower diaphragm?was prepared.Set 3 sets of robot operating parameters and liquid damping rubber parameters to achieve damping glue strip widths of 40mm,55mm and 62mm.And the actual spray test of the liquid damping glue is carried out.The width and thickness of the damping glue strip after spraying were measured.Through data analysis,the optimal opening width of the diaphragm was 22.8mm?upper diaphragm?/28.2mm?lower diaphragm?and the angle was 82.2°?upper diaphragm?/101.8°?lower diaphragm?.In summary,WC-8%Co cemented carbide was selected as the diaphragm substrate,and the surface was plated with CrN/?Ti,Al,Zr,Cr?N film.The diaphragm opening is a diaphragm with a width of 22.8mm?upper diaphragm?/28.2mm?lower diaphragm?and an angle of 82.2°?upper diaphragm?/101.8°?lower diaphragm?,which is the optimal diaphragm for the damping adhesive spray gun.