When to think what raise numerical control machine tool to machine precision

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  • source:WEDEMEYER CNC Machining
Dispatch of net of machine tool of Chinese numerical control: In numerical control machine tool, the expression of precision basically is by the error bulk comes denotive, specific precision cent is two kinds, include static precision and dynamic precision. Among them what static precision points to is do not work in the machine tool do not detect below the condition of cutting come out, main index is the geometrical precision of machine tool itself and fixed position precision, this kind of precision to machine tool precision detect for the primitive precision that can behave a machine tool only; Dynamic precision just as its name implies is a machine tool the precision that detect in cutting process and achieves, the primitive precision that the measurement that this precision is worth included a machine tool and the precision after the environment in machining a process and technology issue are affected express, included to process the brought error such as the cutting tool that chooses in the process, workpiece, vibration. In the manufacturing process of the machine tool the dynamic precision to the machine tool cannot be controlled effectively, what can assure is the static precision of the machine tool, primitive production precision, the treatment precision of numerical control machine tool has the influencing factor of a lot of respects, this will be later development is main discuss content. The error of the itself of machine tool of   of influencing factor   of precision of treatment of numerical control machine tool is mixed in much data make clear in statistic, 65 of the machine tool.

7% above, cannot accord with its completely when installation relevant index level, between the job the numerical control machine tool of 90% is in to break accurate working environment and condition to fall, this kind of circumstance decided the value of monitoring of status of machine tool job, the test of machine tool precision is a necessary foundation for the safeguard to machine tool precision, can better to the treatment precision of the spare parts safeguard. Temperature affects the precision error besides machine tool itself besides, the machine tool is run in what workshop environment falls also can be affected, the temperature that includes a workshop drifts, of electromotor calorific and influence of the attrition that receive discharge, medium, these problems are met the effect that causes certain level to the configuration of the machine tool and precision, the temperature change of the machine tool can appear the forfeiture that adjusts precision, affect somewhat to the precision of the machine tool and the dimension that process work and precision. In the meantime, temperature is elevatory also make bearing clearance produces change, affect treatment precision then. On the other hand, temperature is elevatory make temperature distributings inhomogenous, cause each spare parts or part the mutual position relation between each part produces change, cause the displacement of the spare parts or twist thereby. What so called retrorse deviation points to retrorse deviation is the retrorse dead band that because reference axis is in transmission process,causes in the job of numerical control machine tool or the error appearance that backlash creates, also can become backlash to perhaps lose momentum. To using the numerical control machine tool of servo of half closed circuit, the exists to be able to affect a machine tool fixed position precision of retrorse deviation and repeat fixed position precision, affect the treatment precision of the product thereby. The in machining a process need of machine tool of clearance error numerical control uses transmission chain, the movement of transmission catenary can produce a few gap, these clearance cause an error easily, do not have generation to move in the machine tool in process of electric machinery movement especially, this can create the error question with the bigger perhaps shock of numerical control machine tool. Of precision of treatment of numerical control machine tool raise machine tool of measure     because the precision of machine tool itself also has a difference,choose, this needs us to want to note the alternative of machine tool model and precision on the choice of the machine tool, at present of precision of position of numerical control machine tool examine to use international standard ISO230-2 or national level GB10931-89 to wait normally. Notice somewhat to the standard even in the choice of the machine tool, this is the differs to also can cause precision difference as a result of the standard. The controls sliding bearing machine tool of the spare parts can choose the bearing with better wearability, ensure the working precision of the machine tool thereby. Reduce heat source to the control of workshop environment: The rotate speed that is put in main shaft bearing mainly, clearance is adjusted reach reasonable tighten beforehand. To thrust bearing and tapered roller bearing, because difference of its work requirement is calorific bigger, can convert when necessary ball bearing of thrust horn contact is replaced, give out heat with reducing the attrition of certain component as far as possible. Adiabatic: Make heat source is far from main shaft, if keep apart electromotor, transmission, use detached drive to wait. Medicinal powder hot: Strengthen lubricant refrigeration, use oil wind is cold, cold etc means, accelerate quantity of heat to send out. Reduce hot metabolic effect: Why to no matter use,plant means, can reduce heat to be out of shape only and eliminate heat completely very hard to be out of shape, because this still should take step, in order to reduce hot metabolic effect. The control of retrorse deviation can cause the precision of equipment to become low as a result of retrorse deviation, and as the application of the machine tool time is jumped over long, wear away bigger, the error also is met bigger and bigger, this needs to undertake to retrorse deviation in the applied process of the machine tool periodic detects work with compensation, thereby as far as possible reduce an error, raise precision of machine tool job. What compensation of error compensation error points to is the position that machining a lieutenant general to decide an axis to numerical control machine tool makes corresponding record, in addition, the record data related union and actual measurement undertake comparative as a result, know error value, and be in the datum mark that make choice of measures goes up in the axis in the operation, the record leaves the error value in moving, the input arrives inside relevant control system, the so OK and very good axis movement that controls differentia and error time. If the amount of place measurement point is more, effect of error of compensatory of need of demonstrative pitch place is more apparent, the premise of technology of compensation of this kind of error is to build what in coordinate of numerical control machine tool the department falls, the important parameter that coordinate of machine tool of affirmatory numerical control fastens is reference point, accordingly, the error value of the reference point that must assure a choice is 0. The compensation of backlash error because the influence of error of the backlash in numerical control machine tool, must take seriously adequately to backlash error in the design of numerical control machine tool so, and adopt effective settlement measure. But undeniable is, clearance is existence, what so we should do is to pass pitch error to compensate a technology to run to the machine tool each bits of backlash in the process has a record, and adopt the control system of numerical control machine tool undertake to retrorse motion the compensation of the error is operated directly, the set of the setting that uses parameter thereby and numerical control system will reduce an error. The precision of perfect machine tool of the technology also is in as the development of science and technology be perfected ceaselessly and progress, machine tool precision sides with progress of accept rice class again from original micron class, still need more research and development among them, behave especially go up in bearing technology, the delay that prevents bearing technology is one of difficult problem of development, arrearage phenomenon is attached most importance to especially to the precision influence of fixed position should, the discovery in studying is static press bearing technology to be able to be solved somewhat to mechanical arrearage phenomenon, received many application in the treatment of numerical control machine tool of high accuracy so. The place on put together of epilogue     is narrated, between the treatment job of numerical control machine tool, have a lot of to the precision influencing factor of numerical control machine tool, to these influences we want integration analysis, from many sided as far as possible reduce an error, implementation machines the effective promotion of precision. Origin: Shi Tailong group CNC Milling