Test conditions for internal cylindrical grinding machines with horizontal spindle. Testing of accuracy

This paper describes simulation studies regarding the application of the centrifugal minimum quantity lubrication (MQL) method simultaneously with the delivery of a compressed cooled air (CCA) stream in the internal cylindrical grinding process. The idea of a new hybrid cooling and lubrication method connecting centrifugal (through a grinding wheel) lubrication by MQL with a CCA stream is described. The methodology of computational fluid dynamics (CFD) simulation studies, as well as the results of numerical simulations, are presented in detail. The aim of the simulations was to determine the most favourable geometrical and kinematic parameters of the system in the context of air-oil aerosol and CCA flow, as well as heat exchange. In the simulation, the variables were the grinding arbor geometrical parameters, the angle of CCA supply line outlets, and the grinding wheel and workpiece peripheral speed. As a result of the simulation studies, the most favourable geometrical parameters were designated, determining the orientation of the ends of the two CCA supply line outlets before and after the grinding zone, the number of openings in the drilled-out grinding arbor, and the influence of the grinding speed on the parameters of the coolant flow and temperature of objects in the grinding zone. In addition, the results of simulation tests made it possible to visualise the velocity vectors of the two-phase coolant flow in a complex system of air-oil aerosol delivery centrifugally through an open structure of a very fast rotating porous layer (grinding wheel), with an additional supply of CCA using an external cold air gun (CAG).

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CNC Cylindrical Grinding Machine Reliability Analysis and Optimization

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.716-717.707 ◽

2014 ◽

Vol 716-717 ◽

pp. 707-710

Author(s):

Jin Wei Fan ◽

Xiao Long Yi ◽

Chao Liu ◽

Yong Jun Liu

Keyword(s):

Fault Location ◽

Comprehensive Evaluation ◽

Weak Links ◽

Cylindrical Grinding ◽

Machine Reliability ◽

Cnc Grinding ◽

Complete Failure ◽

Grinding Machines ◽

Grinding Machine ◽

Overall Reliability

CNC cylindrical grinding machine reliability is an important performance indicators, the level of reliability will directly affect the use of CNC cylindrical grinding machine. Reliability of the traditional classification method is not clear, standards are not uniform, the paper application taxonomy for 12 CNC grinding machines from September 2012 to July 2014 for two years more than 600 pieces complete failure and repair data for statistical analysis to identify a greater impact on the overall reliability of the fault location and cause of the malfunction. According to the probability of occurrence of each failure mode, the severity of harm's comprehensive evaluation of the degree of fault of each site, identify the weak links of the whole system. As a result, the reliability of CNC cylindrical grinding machine will be greatly improved.

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