Research On 3D Surface Roughness Of High Speed Cylindrical Grinding And Design Of Grinding Force Measuring Device

The starting point of China's machinery manufacturing level is low,and there is a large gap compared with the manufacturing industry of developed countries.The quality of the parts produced cannot reach the international advanced level.In order to enhance the strength of Chinese manufacturing,some scholars have proposed a "threestep" strategy.The first step is to gradually get rid of the predicament of forming manufacturing and reduce the phenomenon of rough manufacturing.The second step is to gradually achieve surface integrity manufacturing,both to ensure the basic size of parts,in order to meet the relevant testing requirements of surface integrity.The third step is to achieve fatigue-resistant manufacturing and march towards the long life or ultimate life of parts.18Cr Ni Mo7-6 gear steel has the characteristics of high strength and high toughness.It has excellent mechanical properties and is an important material for manufacturing key parts such as gears and shafts.The final process of gear processing is grinding usually.Traditional grinding is prone to burn and micro-crack problems.High-speed grinding can produce parts of high precision and high surface quality.Surface roughness is usually used as a standard to evaluate the quality of the surface of parts.At present,the two-dimensional surface roughness parameters have gradually failed to meet the needs of processing and manufacturing,and the three-dimensional surface roughness parameters can more reflect the true information of the surface of parts,and can also measure the surface quality of a part comprehensively.In this thesis,for the 18 Cr Ni Mo7-6 carburized and quenched gear steel,through the high-speed cylindrical grinding test,the effect of the grinding process parameters on the three-dimensional surface roughness parameters was explored,and the best combination of grinding process parameters was obtained;in addition,the cylindrical grinding force measuring device was designed,and the grinding force was measured initially.This article mainly carried out the following aspects of research:(1)The relevant theory of cylindrical grinding was introduced,the connotation of surface morphology and its measuring methods were introduced,the evaluation system of three-dimensional surface roughness was analyzed,and the three-dimensional surface roughness parameters that are closely related to the performance of parts were selected for research.(2)High-speed cylindrical grinding single-factor test and orthogonal test were designed and implemented.The single-factor test and orthogonal test took the speed of the grinding wheel,the rotation speed of the workpiece,the radial feed speed of the grinding wheel,and the granularity of the grinding wheel as independent variables of the tests.Single factor test took 13 three-dimensional surface roughness parameters(arithmetic mean height Sa of surface,root mean square height Sq of surface,surface ten-point height Sz,surface skewness Ssk,surface kurtosis Sku,fastest attenuation autocorrelation length Sal,surface texture direction Std,surface texture aspect ratio Str,surface peak density Sds,surface support index Sbi,core area oil index Sci,deep valley area volume Sv,valley area oil index Svi)as dependent variables,explored the relationship between each grinding process parameter and each three-dimensional surface roughness parameter;the orthogonal test used the surface arithmetic mean height Sa,surface skewness Ssk,and surface kurtosis Sku as dependent variables,and obtained a better combination of grinding process parameters.(3)Comprehensive analysis of all the test data in this paper,the best combination of grinding process parameters is: the speed of the grinding wheel is 90 m/s,the rotation speed of the workpiece is 90 rpm,the radial feed speed of the grinding wheel is 0.1 mm/min,the granularity of the grinding wheel is W20.The surface roughness of the sample reached 0.037 ?m.(4)A kind of cylindrical grinding force measuring device was designed based on the KISTLER dynamometer.The cylindrical grinding force was measured with the help of a CNC end-face cylindrical grinder(MKE1620A).The changing law of grinding force with the change of the process parameter(the radial feed speed of the grinding wheel)was explored.