Detailed of machining machining complex is solved

Be familiar with machining complex concept, .

The error that understands a system is a little difficult. Actually, machining complex also is to make come out, it also is put in production error necessarily; In use, the machine tool in machining complex, cutting tool, clamping apparatus exists necessarily wear away the error that cause; The installation of cutting tool, workpiece in treatment and adjust also can exist the error is waited a moment. The structural condition of the body in these errors and system is concerned. The error that can produce a system to suffer force, be heated to cause is returned in cutting process. The factor that affects treatment precision is Baconian rise have: .

The geometrical error of machining complex; .

The error that strength effect produces; .

Heat is out of shape the error of generation; .

Internal stress causes be out of shape error; .

Measure an error. Primitive error and machining error.

As a result of the existence of the primitive error of machining complex, make the error that the workpiece after treatment produces is machining error. The primitive error that perhaps can think machining error is machining complex existence is behaved in what get on workpiece. Systematization error and random sex error.

Master error type and property. .

Ought to be familiar with, no matter be systematic error, still be random error, .

L) describes machining error; .

2) is only factor error, the error that causes isolatedly by a kind of reason namely; .

In activity of 3) actual production, affecting the account that processes precision often is daedal. Accordingly, when only factor analyses law inconvenience to analyse a problem, often use statistical method to solve real problem. The suffers force to be out of shape the influence to machining precision is comprised by place of machine tool, clamping apparatus, workpiece, cutting tool machining complex of machining machining complex is a stretch system, the as a result of cutting force, transmission force, force, clamping force and gravity action in machining a process, meeting generation flexibility is out of shape, destroyed the exact position between cutting tool and workpiece thereby, generation machining error. For example when turning slightness axis (graph 1) , below the action of cutting force, because flexibility is out of shape and workpiece appears “ lets knife ” phenomenon. As the feed of cutting tool, in workpiece go up endlong cutting deepness will by changeful little, next again by become less much, the result makes the spare parts produces waist drum form. Machining complex suffers ① force is out of shape the influence to machining precision basically has: In force sufferring to choose the course of machining error cutting that positional change causes in ● cutting process, the stiffness of machining complex orders positional change along with cutting force exert oneself and change, cause systematic metabolic difference, make the spare parts produces machining error. When smooth axis of stubby of the turning between two tips, because workpiece stiffness is bigger, be out of shape with what fall in cutting master piece of opposite machine tool, clamping apparatus and cutting tool be out of shape should small much, reason can be ignorred. Right now, the total deformation of machining complex depends on completely machine tool the head of a bed, rear push frame (include a center) with tool carrier (include cutting tool) be out of shape, the error that workpiece produces spends an error for hyperbola cylinder. When axis of slightness of the turning between two tips, because workpiece is long and thin, stiffness is small, below cutting strength effect, its are out of shape exceed machine tool clamping apparatus and cutting tool greatly suffer force to be out of shape. Accordingly, of machine tool, clamping apparatus and cutting tool suffer force to be out of shape can skip not plan, right now, craft fastens be out of shape depend on completely of workpiece be out of shape, workpiece produces cylinder of waist drum form to spend an error. Mental allowance of ● semifinished product not all, error answer mirrors the machining error —— that material hardness change brings about variation of cutting power volume to cause although the semifinished product appearance of workpiece has rough spare parts figure, but it is on dimension, appearance and uniformity of hardness of exterior layer material have bigger error. These errors of semifinished product make when treatment cutting deepness produces change ceaselessly, cause the change of cutting force thereby, cause machining complex to arise to be out of shape accordingly then, make the spare parts returns the figure with reservation and semifinished product similar surface or on size error after treatment. Of course the error that workpiece surface remains wants than error of semifinished product surface small much, this kind of phenomenon calls “ error answer mirrors regular ” , the machining error that causes calls “ answer mirror error ” . ② reduces machining complex to suffer force metabolic measure to basically have: It is the stiffness when raising workpiece to machine; 2 it is the clamp stiffness when raising workpiece to install; 3 it is the stiffness that raises machine tool part. Heat of machining machining complex is out of shape the influence to machining precision is reached in reducing machining complex to heat up metabolic measure machining, machining complex produces certain heat to be out of shape below the action of all sorts of heat source. What reach each link structure, material as a result of the inhomogenous sex that machining complex heat source distributings is different, make machining complex departmental of cent be out of shape generation difference, the exact position that destroyed cutting tool and workpiece thereby and motion concern, generation machining error, machine to nicety especially, heat is out of shape the machining error that cause occupies the half above of total error. Accordingly, in latter-day and accurate treatment, control heat is out of shape the influence to machining precision already made main task and research task. In machining a process, the heat source of machining complex basically has inner heat source and exterior heat source two kinds big. Inner heat source comes from cutting process, basically include heat source of heat of heat in metal cutting, attrition, derive. Exterior heat source basically comes from at external environment, basically include environmental temperature and heat radiation. The heat that these heat source produce causes the heat of workpiece, cutting tool and machine tool to be out of shape. Reduce machining complex to heat up metabolic measure to basically have: It is to reduce the heat source of machining complex to reach its calorific quantity; 2 it is to strengthen refrigeration, rise medicinal powder heat energy force; 3 it is control temperature change, balanced temperature; 4 it is to adopt compensation measure; 5 it is to improve machine tool composition. In addition, still should notice to improve machine tool composition, reduce its heat to be out of shape. Consider structural symmetry above all. On one hand transmission component (bearing, gear) answer in the installation inside casing as far as possible symmetrical, the quantity of heat that makes its pass box wall is balanced, be out of shape close; On the other hand, some spare partses (like casing) should use hot symmetrical structure as far as possible, so that be heated is even. Still should notice reasonable select material, ask to precision tall spare parts chooses the material with small coefficient of expansion as far as possible. CNC Milling