Research On Support Methods For Manufacturing Process Reliability Of Machine Center Spindle Box

The reliability of product depends on the design, manufacture, assembly, management, and other factors. The current research on reliability of CNC machine tool represented by machining center mainly focuses on the reliability design, reliability modeling, reliability test and failure analysis, etc., but the research on craft reliability for CNC machine parts is not involved. The spindle box is one of machine center’s key parts. Research on support methods for manufacturing process reliability of machine center spindle box is not only beneficial to reducing the manufacturing fault of machining center spindle box, but also can support the reliability of machining center, and provide the reference for the research on support methods for manufacturing process reliability of other CNC machine tool parts.The research object of the Paper is the support methods for manufacturing process reliability of machine center spindle box. The paper defines the manufacturing process reliability of machining center spindle box and its evaluation indexes. Process FMECA is carried out to get improvement measures against the possible manufacturing fault. Control chart analysis is carried out to find the abnormal factors in the process of manufacturing and exclude them so that manufacturing fault is prevented. The key process quality control points are set up to prevent the manufacturing fault. The paper is mainly as follows:1. The paper Introduces machine center spindle box’s structure and function and illustrate that different types of machine center spindle box have the similarity in the manufacturing process. The paper defines the manufacturing process reliability of machining center spindle box and its evaluation indexes, in addition, describes the meaning of each evaluation index and calculation methods in detail.2. Process FMECA is carried out to support the manufacturing process reliability of machine center spindle box. Trapezoidal fuzzy number is used to judge process failure mode to failure reason while risk priority number as judgment criteria, so that the paper get the degree of failure risk. Comprehensive judgment method is carried out to calculate the risk level of manufacturing process system so that the paper can determine whether carrying out the improvement.3. Control chart analysis is carried out to support the manufacturing process reliability of machine center spindle box. The paper compiles x-s control chart analysis software for machine center spindle box. The software can calculate sample data quickly and accurately, besides that the software can draw S chart and x chart so that the abnormal factor can be fined. The control chart with control moment can be get by excluding the abnormal factors and sample data to monitor manufacturing process fluctuations of machine center spindle box.4. The key process quality control points are set up to support the manufacturing process reliability of machine center spindle box. The paper defines the common key process and special key process and gives the methods for searching. The 5M1 E factors are closely related to the manufacturing process, so that the paper sets up the control files according them and gives the methods of establishing and managing the key process quality control points.The paper researches the methods for manufacturing process reliability of machine center spindle box from multiple perspectives so that the methods can meet the needs of machine tool manufacturing company in practical applications.