| The cutting fluid can effectively improve tool life,surface finishing and machining efficiency during the process of metal cutting.However,the excessive use of Lubricant will not only cause serious environmental pollution and increase production costs,but also easily damage operators'health through direct contact or breathing intake.Minimal Quantities of Lubricant Technology,or MQL,is one kind of green processing technology which has the characteristics of low consumption and high efficiency,can easily permeate the lubrication medium into the processing area under the action of compressed air.But at present,the technical limitations of cooling medium which is difficult to spray precisely into the cutting area greatly hinder the engineering popularization of MQL technology.In this paper,the research on precise fixed-point spraying technology of MQL cooling medium is carried out.And the research background,development status and achievements of MQL technology and related equipment are described.In order to actively spray coolant and eliminate external MQL technical defects,a precise spraying system of MQL cooling medium was designed,including a mechanical structure that can be installed in the narrow space of the spindle position of CNC machine tools,and a control system that can coordinately adjust the whole device.In the research and development of the mechanical structure of MQL system,according to installation environment,testing attributes of the tool and verification requirements of the cooling effect,a kind of tool nose coordinate detection technology which combining the specific band invisible laser indication and narrow band filter method is proposed.Develop a high toughness resin 3D printing combined with flexible rod body lightweight follow-up joint processing scheme to ensures the injection accuracy of the system.An early warning strategy for real-time temperature shear monitoring of infrared thermal imaging core is laid out to ensure the sensitivity and safety of the MQL system.Based on the compilation of MATLAB image analysis algorithm and GUI interface design,the control system of MQL cooling system is developed.Image processing algorithm for tool geometry parameter detection and detection algorithm for rectangle outside connected domain is proposed on the platform of MATLAB,and the absolute value error oftool end coordinate is less than 0.08mm.Based on the secondary development of VERICUT,the real-time cutting parameters of NC program can be obtained during processing and the data will be transmitted to the control system through the PCB control board.Combining with the pre-measured tool size information,the position coordinates of the current cutting area are calculated to control the movement of the follow-up joint and spray towards the cutting area.Based on the MQL milling experiment of titanium alloy,the effects of MQL system parameters such as injection angle,injection distance and medium flow rate on the cutting effect were studied,and the mechanism of the effects of various MQL parameters on different cutting performance of workpiece was revealed.The MQL parameters optimization results were calculated by Minitab software,which provided data support for the subsequent structure optimization of MQL system. |
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