Rearch On The Dynamic Analysis Of The Jaw And The Vibration Drawing Process Of Copper Tube

With the market requirement of refrigerator,air conditioning,automobile engine,generator is increasing year by year,the Copper tube processing industry is getting more and more attention.The copper pipe production efficiency and the shaping quality requirements are becoming higher and higher at the same time as the copper tube requirement is increased.The matching of jaw structure parameters and drawing process parameters has a great influence on the quality of copper tube forming.Therefore,it is of great research value and application prospects to carry out jaw dynamic analysis and vibration drawing process research.In this paper,the following works have been completed by using a combination of theoretical analysis,numerical simulation and experimental research.For the problem of slippage of the jaws,an improved design of the existing jaw clamping device is performed.By applying the plastic forming technology to the production of the copper tube,it helps to reduce the deformation of the copper pipes and improve the quality of the product.Based on the actual production and the finite element software MSC.MARC,the low-frequency vibration drawing process of the copper tube moving core is studied.The main research results of the paper as follows:(1)Aiming at the problem of slipping of the jaws during the current production process of copper pipe drawing,this paper makes a qualitative analysis of the reasons for slippage,and improves the design of the existing drawing jaw device.Based on the ADAMS to establish the rigid-flexible coupling model of the jaw clamped brass pipe clamp,and the dynamic analysis of clamping process was carried out.The clamping force of the clamp is the evaluation index.The optimum range of jaw angle,diameter of copper pipe clamp,and contact length between copper pipe clamp and jaw is established,which provides a reference for the angle of the jaw and the technology of the brass pipe clamp.(2)Taking the H63 copper alloy pipe as the research object,the vibration tensile test of different vibration parameters(amplitude,frequency)was carried out in consideration of the influence of vibration on the structure of the copper tube material.The true stress-strain curve of H63 copper alloy vibration drawing is obtained.The phenomenological modeling method is used to establish a vibratory tensile constitutive model of H63 copper alloy based on elasto-viscoplasticity.The vibration of H63 copper alloy is introduced into the finite element software MSC.MARC,and the mechanical properties of the tubular pipe with vibration drawing and conventional drawing of the copper tube are compared and analyzed.The results show that the addition of low-frequency vibration reduces the pull-pull force of the copper tube's moving core and reduces the unevenness in the forming process,which helps to improve the tube forming quality.(3)To explore the influence of vibration parameters(amplitude,frequency),drawing speed,mold taper angle and friction coefficient on the low-frequency vibration drawing force of the copper tube moving core.Based on the CCD response surface methodology,the process parameters of the low-frequency vibration drawing of the copper tube's moving core are matched,and the prediction model of the low-frequency vibration pulling force of the copper tube's moving core is established to obtain the best combination of process parameters.(4)"Hollow" type pneumatic exciter with adjustable excitation force and excitation frequency respectively is designed.Setting up a low-frequency vibration experimental platform for drawing copper tube cores for low-frequency vibration pulling of copper tube.It verifies the fact that the low frequency vibration can reduce the pulling force of copper tube.It is found that that grain size of the tube tissue distribution is more uniform,and it is indicate that the introduction of low frequency vibration is good for improving the shape quality of the copper tube.It is shown from above that the results of this study provide an effective approach for the theoretical research and technical development of copper tube drawing and have a good practical value.