Assembly Fault’s Detection And Analysis Of Spindle-box Based On Dynamic Characteristics

The development of machine tools and its technical level directly reflect the development trend of a country’s machinery industry, and map the level of industrialization of a country. As an important part of the machine, the spindle box plays an important role in ensuring the machine tool is in the state of large load cutting. In order to avoid the fault in the assembly process, the spindle box needs to be installed and debugged repeatedly. The practitioners pay more attention to the optimization of the structure, cutting performance improvement, not attach importance to the research on the assembly process, related field’s research is not deep enough; some of the workers in the assembly process of the machine tool did not strictly enforce the assembly process planning. Therefore, it is significant to study the assembly fault detection of the machine tool spindle box.The TONTEC’s mainstream products VCL850 vertical machining center as the research object, on the basis of sufficient investigation of the existing assembly process, combined with TONTEC’s Machine Tool in the assembly of the experience accumulation, the spindle box assembly fault detection and analysis as follows:First, main common assembly fault of Machine Tool spindle box’s area were in-depth investigation and research, and in view of the spindle box’s area measurement system is designed using LabVIEW, including:spindle shaft center trajectory measuring and spindle box area’s vibration signal testing. The interface is easy to operate, with the function of filtering noise reduction, time frequency domain analysis, axis orbit testing, phase detection, fault type identification etc..Then, in order to determine the time and frequency domain signal characteristics of different faults of the spindle box, simulation tests are carried out on the rotor test rig for the dynamic unbalance, the angle misalignment and the loosening of the assembly faults. Secondly, the spindle box of VCL850 is tested on line, and the sensors are optimized according to the principle of modal kinetic energy method and effective independence method. The original signal of the machine tool is noise reduction and filtering, using two kinds of (SVD method, invariant moment method) identification methods, to achieve the spindle box assembly fault type’s determination.Finally, based on the principle of transfer path analysis, the location of the fault source in the spindle box’s area is determined. Firstly, the workbench ANSYS is used to simulate the fault location of the spindle box area:from the perspective of the frequency response function (FRF) established transfer function matrix of the spindle box area, arranged the sensors, to obtain the response of the test point information and analytical source fault location by ANSYS Workbench. Its feasibility is demonstrated. Then the LMS data acquisition system is used to identify the source location of a mechanical structure by two different excitation methods, which can effectively determine the specific location of the source.