Research On Preload Determination Method For Efficient Assembly Of Rolling Linear Guide Pair

Through the on-site use of CNC machine tool enterprises and a large number of early tests by the major national science and technology project undertakers,it is shown that the key factor affecting the overall machine tool and the low machining accuracy is the low assembly accuracy of the machine tool guide.At present,for the precision assembly and complicated production of multiple varieties,there are problems: low assembly accuracy and poor assembly efficiency;the mechanism of geometric error on assembly accuracy is not clear;manual selection and selection of parts are inefficient,and assembly methods are intelligent low.More importantly,the current testing methods for assembly accuracy are not clear,and the assembly accuracy cannot be quantitatively tested directly through experiments.To this end,this article takes the national science and technology major project(2019ZX04010001)as the research background,and compares the precise control methods of the preload of the linear rolling guide through the measurement and analysis of the load distribution and the dynamic friction coefficient when the linear rolling guide is loaded.In-depth theoretical and experimental research,combined with self-developed efficient assembly software,finally realized the efficient assembly of linear rolling guide pairs.(1)The load distribution model of the linear rolling guide pair under the fivedimensional load condition is established.Under the premise of considering geometric errors,a load distribution model for linear rolling guides under the combined action of vertical and horizontal loads and three-direction bending moments is established.Through Ansys simulation,the correctness of the load distribution model was verified,and the load distribution of the linear rolling guide pair under different loads,bending moments and geometric errors was further analyzed,which provided a theoretical basis for accurately calculating the preload of the linear rolling guide pair.(2)Innovatively designed the pre-load adjustable loading device of the linear rolling guide pair,and constructed the pre-load and pre-tightening drag force synchronous online measurement system.The dynamic friction coefficient under different loads and speeds is measured,combined with the load distribution model,the accurate calculation method of the preload of the linear rolling guide pair is established,which provides support for the subsequent development of the automatic matching software of the linear rolling guide pair parts.(3)The matching relationship test of preloading,preloading and dragging force and rigidity of the linear rolling guide is designed,and the test requirements,sample requirements,test principles,test methods and procedures,and test equipment of the two types of tests are introduced.The data processing method and process of the rigidity and the preloading force of the tested sample with respect to the preload is presented,and finally the assembly relationship between the preload and rigidity of the SHS-35 V series guide rail pair is obtained.(4)Based on the Visual Studio development tool,the matching relationship between the rigidity,pre-tightening drag force and preload of the SHS-35 V series guide rail pair is algorithmized,and the material information of the guide pair parts is further combined to design a general matching degree Function,developed the high-efficiency assembly software of the linear rolling guide pair,and finally realized the automatic matching of the parts of the linear rolling guide pair.