Measure to 3 coordinate machine is automatic the research that measures a technology
- source:EASCOR CNC Machining
The trend measuring a head when be being measured automatically is shown 1 times like the graph, if measure a head to stay in place of initiative position A, nod C to explore working surface, drive quickly first commonly measure a head to arrive a bit B with very close upper part of bit of C surface normal, just ask along normal again slow fast exploration dot C, bit of D arrives quickly later, slow fast exploration dot E... relapse so, pointwise is measured. Measure after finishing, measure a H part that keeps in hollowness. The purpose of so rapid movement is to improve metrical efficiency, and slow fast exploring is to assure to measure precision. Weigh dot B, D, F to avoid barrier is nodded, nod what dot C, E and G say to explore, it is what BC, DE and FG say " exploration direction vector " . Actually, after measuring a head to wait for a dot to go ahead to express surface contact with workpiece with law of low speed edge in C, E, G, retreat a paragraph of small distance early or late, measure a head in order to protect to avoid damage to kill. This one distance normally very small, only zero millimeter arrives 2mm (graph 1 did not express) , move toward again avoid barrier nods D, F, H. If measure foregone geometrical essential factor, these " avoid barrier is nodded " , " exploration dot " and " directional vector " can generate automatically through the program. If measure unknown essential factor, through the person with respect to need labour is measured and with self-study review process records them. 2.
Measure automatically measure automatically should compare measure artificially compared to the same period managing very big man-hour, measure accuracy taller, the result after measuring is stabler. Should measure a batch of atomizer when the dimension of impaction piece spare parts, undertake will measure artificially to certain spare parts above all, the computer artificial operation whole process and pertinent information are written down, save at the same time come down, repeat when measuring, place workpiece according to the means outfit that measures artificially, building coordinate is. Next, benefit is joined with a few pertinent information that measure artificially avoid barrier dot writes the program that measures automatically necessarily. Finally, change the hand means instead automatic means undertakes be metricaled automatically. 2.
CMM of of workpiece of 1 outfit clip is right the installation that the product that be measured is measuring a space is fiducial without special requirement, but want what convenient workpiece coordinate fastens to build. Because measure a process actually of CMM,be to be after the data that gets measurement point, with mathematical calculative method is reductive the position between an element of the geometry that be measured and them affects, install clip to finish what what require data collect because of when this is measured, should be being used as far as possible, in order to ensure the measurement of workpiece precision, because install what place and cause to measure conversion error for many times,decrease. Select the end panel of workpiece commonly or enclothe big surface to regard as measure fiducial, if foregone be measured treatment datum plane, should serve as with its measure fiducial. 2.
2 build coordinate to be fastened before measuring a part, must building accurate workpiece coordinate is, facilitating spare parts measures the data processing that reachs sequel. Measure relatively simple geometry measure (include opposite place) use machine coordinate is OK. And measuring a few relatively intricate work to need umbriferous on a certain datum plane or when wanting for many times to have fiducial shift, workpiece coordinate fastens build appear in measuring a process particularly important. Workpiece coordinate fastens build means to depend on spare parts type and the case of basic geometry element that the spare parts has. Among them the most commonly used through face, line, dot the feature builds workpiece coordinate department to include 3 measure, and have its firm order. Specific be: (1) affirmatory space is planar, choose datum plane namely. Be being measured through measuring a plane on the spare parts to search spare parts, make sure Z axis is vertical at this datum plane: (2) affirmatory and planar axes, choose X or Y axis namely. Affirmatory among them after one axes direction, according to the right hand formula can determine the direction of another axes: (3) setting coordinate origin. The datum plane that set measures is Z=0, x axis is Y=0, y axis is coordinate origin for the dot of X=0. What the input in the module of coordinate department function in PC-DIMS software measures or element of tectonic face, line, dot builds workpiece coordinate department automatically. Be based on CAD digital-to-analogue detect the woof that should fasten a choice to need to measure according to the coordinate on CAD digital-to-analogue. If the graph is shown 2 times, measure workpiece first go up the surface -- one plane 1, its the definition is datum plane, the square that builds Z axis to. Measure linear 1 its the definition is X axis, the square that can decide Y axis according to right hand formula to. Restrain origin Z value with datum plane, restrain the Y value of origin with X axis, measure again linear the X value of 2 ties origin, get the origin of coordinate department, building working coordinate is. This kind of commonly used workpiece coordinate fastens establish a method, also call 3-2-1 way. If need a few to measure coordinate department at the same time, can name its and store, build the 2nd with same method again, the 3rd measures coordinate is, when measuring, call neatly can. 2.
The measurement of 3 features element 3 coordinate measure machines and tools to two kinds measure way: The hand is moved measure, measure automatically. The hand is moved measuring is to use a hand to accuse box hand to move control to measure the motion of the head to undertake metrical, commonly used will measure a few woof, pass what to its exterior feature nods to measure what can get a result to survey a project directly namely, be like: Dot, line, face, round, columnar, conic, ball, clitellum. If the hand is moved,measure a circle, need to measure a circle to go up only 3 are nodded, software can be calculated automatically position of this round the centre of a circle and diameter. Be being measured automatically is mode is measured to fall in CNC, carry out what had written beforehand to measure programme controll machine is automatic detect. Anyhow, when measuring batch part, measure automatically omited the trouble of the operation, big political integrity restricted time, increased metrical efficiency and stability. When if measure,be not batch spare parts, measure automatically will no longer applicable. Current, also just system of a few CAD has coordinate to measure process designing function, but it is the interactive dialog that relies on height, do not have " detect program " and " measure method to be generated automatically " function. If 3 coordinate are measured machine have these functions, the applicability that measures automatically will be more extensive, the advantage also can get reflecting more. CNC Milling CNC Machining