迹字石油化工大學⊙ Chapter Five Machining Quality and Analysis
Chapter Five Machining Quality and Analysis
迹字石油化工大學⊙ Instructional objectives At the end of this lesson the student would be able to (1). Understand the basic concept of machining accuracy, machining error and machining economic accuracy etc (2). Master the error of machine tool and adjustment error, understand the influence of stress and deformation on machining accuracy of process system, machining error caused by thermal deformation of process system (3 ) understand the deformation caused by internal stress, and understand the ways to ensure and improve machining accuracy and the method of obtaining machining accuracy for parts
Instructional objectives At the end of this lesson, the student would be able to : (1).Understand the basic concept of machining accuracy, machining error and machining economic accuracy etc. (2).Master the error of machine tool and adjustment error, understand the influence of stress and deformation on machining accuracy of process system, machining error caused by thermal deformation of process system,. (3).understand the deformation caused by internal stress, and understand the ways to ensure and improve machining accuracy.and the method of obtaining machining accuracy for parts
遼字石油化工大學⊙ AWorking with Industry to Create Precision Machines Moore Tool PAMT for Defense Logistics Agency Moore tool 5-axis Contour mil Moore Nanotech 150 Aspheric Grinder Convole/Moore animation Camera Stand Weldon 1632 Gold Cylindrical Grinder Coors Tek all-ceramic grinder ncms cluster spindle oMAX JetMachining TM Centers .Elk Rapids 5 axis cutter grinder NcMs HydroBushing M and Hydrospindle M norad/ Dover minimi‖ Teradyne K-Dock System, Manipulator& Apollo sorter
A.Working with Industry to Create Precision Machines •Moore Tool PAMT for Defense Logistics Agency •Moore Tool 5-axis Contour Mill •Moore Nanotech 150 Aspheric Grinder •Convole/Moore Animation Camera Stand •Weldon 1632 Gold Cylindrical Grinder •CoorsTek all-ceramic grinder •NCMS Cluster Spindle •OMAX JetMachining™ Centers •Elk Rapids 5 axis cutter grinder •NCMS HydroBushing™ and HydroSpindle™ •Anorad/Dover MiniMill™ •Teradyne K-Dock System, Manipulator & Apollo Sorter
迹字石油化工大學⊙
迹字石油化工大學⊙ B Machines are Tool-Work Systems The goal is to figure out what motions should occur to make the tool do what it is supposed to do on the work One must also think of the motions one does not want to occur(error motions)and what their effect is on system performance To fill in the mechanism between the tool and the work. one must understand fundamental principles, machine elements and manufacturing An Error Budget can be used to keep track of errors in a machine elements and manufacturing methods and their cumulative effect on the machine Quality, robustness, reliability, cost.depend on minimizing complexity and trying to maximize accuracy for minimum cost
B.Machines are Tool-Work Systems • The goal is to figure out what motions should occur to make the tool do what it is supposed to do on the work – One must also think of the motions one does not want to occur (error motions) and what their effect is on system performance • To fill in the mechanism between the tool and the work, one must understand fundamental principles, machine elements, and manufacturing – An Error Budget can be used to keep track of errors in a machine elements and manufacturing methods and their cumulative effect on the machine – Quality, robustness, reliability, cost….depend on minimizing complexity and trying to maximize accuracy for minimum cost
迹字石油化工大學⊙ error work 16521(Mh)C单( CMAX
迹字石油化工大學⊙ C The Machine is a Structural loop The structural loop contains all the joints and structural m e that position the tool wrt the workpiece A stick figure of machine motions can outline the structural loop The structural loop gives an indication of machine stiffness and accuracy Long-open loops have less stiffness and lann ann rn Structural loo X carriage Toopindle Workpiec Workpiece Fixture Fixture Y table XY table
C.The Machine is a Structural Loop • The structural loop contains all the joints and structural e l e m e n t s that position the tool wrt the workpiece – A stick figure of machine motions can outline the structural loop • The structural loop gives an indication of machine stiffness and accuracy – Long-open loops have less stiffness and less accuracy
迹字石油化工大學⊙ D Where the errors act the center of stiffness a body behaves as if all its mass in concentrated at its center of mass a body supported by bearings, behaves as if all the bearings are concentrated at the center of stiffness The point at which when a force is applied to a locked-in-place axis, no angular motion of the structure occurs It is also the point about which angular motion occurs when forces are applied elsewhere on the body Found using a center-of-mass type of calculation(K is substituted for M) ◆K: ◆
D.Where the Errors Act: The Center of Stiffness • A body behaves as if all its mass in concentrated at its center of mass • A body supported by bearings, behaves as if all the bearings are concentrated at the center of stiffness – The point at which when a force is applied to a locked-in-place axis, no angular motion of the structure occurs – It is also the point about which angular motion occurs when forces are applied elsewhere on the body – Found using a center-of-mass type of calculation (K is substituted for M)
迹字石油化工大學⊙ E Creating Successful Machines Leading Vs. Bleeding Edge Technology for the sake of itself has little use when it comes to proauction macninery Leave no microns on the table elbat eht no srallod no eval Design for the present and the future Modularity is the key to upgrading designs to the next technology curve Sensors and software are key upgrading catalysts Understanding errors in components and machines is the key to staying on the leading edge!
E.Creating Successful Machines: Leading vs. Bleeding Edge • Technology for the sake of itself has little use when it comes to production machinery – Leave no microns on the table:elbat eht no srallod no evaeL • Design for the present and the future – Modularity is the key to upgrading designs to the next technology curve – Sensors and software are key upgrading catalysts • Understanding errors in components and machines is the key to staying on the leading edge!
迹字石油化工大學⊙ Pure mechanical Servo axes Mapped servo Bleeding edge Coagulated edge Leading edge Performance