The influencing factor of precision of treatment of numerical control lathe and raise measure

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Summary: The treatment precision of numerical control lathe affects the quality of mechanical spare parts directly, because this machines the influencing factor of precision,be paid close attention to extensively. It is in article on the foundation of composition of lathe of overview numerical control and working principle, studied numerical control lathe machines the influencing factor of precision, put forward to raise numerical control lathe to machine the significant step of precision, certain to discussing what numerical control lathe machines precision to raise measure to have further draw lessons from action. Lathe of foreword numerical control already received wide application in the mechanical manufacturing industry nowadays, create for enterprise and society very the economic benefits that showing. The precision of mechanical product is affecting the character of service of the product directly, and the precision that the precision control of numerical control lathe is affecting place to process mechanical product directly. As the development of mechanical manufacturing industry, taller and taller to the precision requirement of mechanical product, corresponding ground also raised taller requirement to the treatment precision of numerical control lathe. lathe of ordinary numerical control, its machine precision cardinal principle to decide by 4 parts: The precision that lathe itself makes; Precision of numerical control process designing; Lathe servo precision; The precision of interpolation link. Lathe affects treatment precision likely also in element of each process in machining a process, block close link for example, detect link and external environment. To the precision of numerical control lathe so control wants to have integrated consideration and control. 1, the lathe of compositive numerical control of numerical control lathe basically comprises by 4 parts: Lead plane system, system of numerical control process designing, drive system, process support system [1] . 1) lead plane system. Lead plane system is the main body part of machining, basically carry out the cutting treatment to workpiece. Its component is main wait for treatment component by component of main shaft, lathe bed, pillar, feed. 2) system of numerical control process designing. Numerical control system is to have fasten the crucial part at general accuracy machine tool, also be the core component of CNC Machining, by hardware equipment and corresponding software composition, basically finish the order input of machining and memory, machine tool of partial numerical control also can be over to input the treatment of parameter and processing in couples, fulfil certain and specific operation function. 3) drive system. Drive system provides motive power for treatment of numerical control lathe, the machining that finish. Basically include structure of electric machinery of main shaft electric machinery, structure of main shaft drive, feed, feed to wait, by drive system through servo orgnaization control achieves main shaft motion and feed exercise. 4) process support system. Processing support system is to point to a few necessary auxiliary orgnaizations in machining manufacturing process, those who make sure cutting is machined is successful finish. Basically include revolving stage of the eject orgnaization, orgnaization that discharge bits, numerical control, monitor with detect orgnaization, main effect is cooling, platoon bits, illume, lubricant etc. 2, the lathe of working principle numerical control of numerical control lathe and common lathe have very big distinction on treatment process, the member that the need when common lathe is machined machines a person machines a graph to change the athletic contrail of lathe tool ceaselessly according to the spare parts, will complete the treatment of mechanical spare parts. And numerical control lathe is through numerical control cutting tool and relevant member programming language has set, input the device of NC, through servo drive corresponding lathe component completes the treatment of the spare parts, its are specific the process is shown 1 times like the graph [2] . 3, the treatment precision that the machining precision of the itself of lathe of influencing factor numerical control of precision of treatment of numerical control lathe and servo drive precision can affect numerical control lathe. The error that the cause that specific fractionize affects numerical control lathe to machine precision basically has heat of error of lathe itself geometry, lathe to be out of shape change of parameter of error, servo drive error, lathe tool is caused. In treatment of numerical control lathe, the servo drive error, error that change of lathe tool parameter causes is relatively common. To this two kinds of influencing factor undertake labor below. 3.

Element of 1 servo drive makes a principle by numerical control turner knowable, servo completes the treatment of the spare parts through drive lathe component, its are specific the process is: The fixed position of numerical control lathe is finished by ball guide screw, ball guide screw is undertaken controlling by drive of servo electric machinery, the transmission error of ball guide screw becomes one of influencing factor of fixed position precision. Numerical control lathe uses control of system of feed of servo of half closed-loop control commonly, its job principle is shown 2 times like the graph [3] . Machining a process normally, when guide screw is undertaken by control of servo electric machinery direction runs turning over, the empty movement phenomenon of meeting occurrence space, cause backlash error. The drive that controls lathe with duration and athletic orgnaization issue meeting generation flexibility to be out of shape in outside force action, and other position suffers treatment place and lathe force differs, cause stretch clearance to happen to also affect treatment precision. This part error is running to transmission for backlash sum of errors the overlay of the error. 3.

The treatment process of lathe of numerical control of element of change of parameter of 2 lathe tool basically is lathe tool in process designing control falls to undertake cutting to the spare parts, reach wants workpiece form. The tool cutting edge angle of lathe tool existence that turning machines and radius of circular arc of point of a knife [4] , expect to the club kind when undertaking machining, its axes dimension can be put in certain deviation, this one deviation and tool cutting edge angle become inverse ratio, follow the accretion of tool cutting edge angle and reduce, become direct ratio with radius of circular arc of point of a knife. So, when undertaking process designing to numerical control lathe need basis machines the characteristic of the spare parts, consider the deviation rule of axial dimension inside, to its relevant displacement length undertakes adjustment. When numerical control lathe runs, the high deviation of the radius of circular arc of point of a knife of lathe tool, tool cutting edge angle, point of a knife and spare parts center treatment precision that affects numerical control lathe possibly, need undertakes consideration and analysis when process designing. Basis before research, the difference with the influence degree certain existence that affects numerical control lathe to machine precision element, to its collect classification can get: Place of lathe itself error occupies scale to be 45%~65% , the process error place in treatment occupies scale to be 25%~40% , detect error place occupies scale to be 10%~15% . 4, the treatment precision that raises numerical control lathe to machine the significant step of precision how to raise numerical control lathe, production gives more accurate part, it is the stress that the scholar pays close attention to and studies all the time, machine the influencing factor of precision according to numerical control lathe, can be controlled through raising compensation method of slideway geometry precision, error, error to avoid a law and raise treatment precision. 1) raise slideway geometry precision. The development trend of numerical control lathe machines precision speed, high for tall cutting, higher cutting rate can cause vibration necessarily, so need slideway has better precision stability and taller stiffness, can use steeliness to slide the method of orbit whole grinding undertakes rising. Specific means is: Numerical control lathe uses the steeliness sliding slideway after hard processing of temper by dipping in water when the design, secure with bolt going up by the plane after slideway grinder grinding, aperture undertakes plenitude with the filler that note model between slideway and slideway base, undertake integral grinding finally, obtain better geometrical precision. 2) error compensation method. Error compensation method is the compensation function that adopts numerical control system, have compensatory method to the reference axis deviation that already existed, the lathe with not tall precision can go out through treatment of error compensation method relatively the product of high accuracy. This method can be finished by hardware or software. Use the numerical control lathe of servo of half closed circuit for example, as a result of the influence of retrorse deviation its locate precision exists error, can use methods of pair of retrorse deviation compensatory to eliminate an error [5] . 3) the error avoids a law. The error avoids a law is the design in numerical control machine tool and the error that production phase eliminates a likelihood to exist through raising the precision of mechanical spare parts. This method can go up from whole the error that better land reduces treatment precision, but cost is higher, and lathe of this numerical control is on original basis continue to improve treatment precision difficulty is greater. 5, the epilogue development as manufacturing industry, numerical control lathe is applied extensively as a kind of efficient automation machine tool, its machine the discretion of precision to affect the quality of the product and character of service directly. The article is in brief on the foundation that elaborates composition of numerical control lathe and working principle, studied numerical control car machines the influencing factor of precision, basically change to element of its servo drive and lathe tool parameter the element undertook labor. Advanced 3 kinds of significant step that raise numerical control lathe to machine precision, it is respectively: Raise compensation method of slideway geometry precision, error, the error avoids a law. To further research and treatment of lathe of analytic numerical control precision has fair referenced value. CNC Milling CNC Machining