Reduce the measure of machining error

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  • source:TANAY CNC Machining
The measure that reduces machining error roughly but reduce   of the following respects one, reduce primitive error law to be namely after the element of main and primitive error that finds out an influence to machine precision directly, try to undertake eliminate or decreasing directly to its. For example, when turning slightness axis, use the machining error that can be eliminated with tool carrier, center wearing or reduces workpiece to be out of shape place is caused. Use big feed retrorse cutting law, basically eliminated what axial cutting force causes to bend be out of shape. If complementary with bedspring tip, can eliminate the machining error that heat is out of shape place is caused further. If be in,machine the Kong Shi inside thin wall sleeve again, use excessive cirque to distributing in order to make clamping force even, avoid the machining error that clamp is out of shape place is caused. 2, error compensation method makes a kind of error artificially when   error compensation method, go offsetting machining complex originallies some primitive errors, perhaps use a kind of primitive error to offset another kind of primitive error, achieve the goal that raises treatment precision thereby. For example, with add slideway of lathe bed of grinder of load law finish machining beforehand, the part gets after compensation of so as to is assembled self-prossessed and cause be out of shape. Grinder lathe bed is a long and narrow structure, stiffness is poorer, when treatment, slideway although 3 precision can be achieved, but after waiting in mount feed orgnaization, clutch operation, can make slideway generation is out of shape and destroyed original precision, use add load law to be able to compensate this one error beforehand. If use corrective orgnaization,raise the precision of catenary of drive of guide screw lathe again. In accurate thread machining, error of catenary of machine tool drive will be mirrorred to the pitch of workpiece directly, make accurate guide screw machines precision to be affected certainly. To satisfy the requirement that accurate guide screw machines, use thread machining the error that corrective device causes with eliminating transmission catenary, if pursue 4, 40 are shown. 3, the gather error that the essence of law of move of error of   of error move law is move machining complex, suffer force to be out of shape be out of shape with heat etc. For example, when taper hole of grinding main shaft, the coaxial of taper hole and axial diameter is spent do not rely on precision of circumgyrate of machine tool main shaft to assure, rely on clamping apparatus to assure however, after using float to join when machine tool main shaft and workpiece, the primitive error of machine tool main shaft affects treatment precision no longer, and move assures to machine precision to clamping apparatus. In the aperture department treatment of casing, when be being fastened with aperture of boring model boring on boring machine, the dimension precision between the positional precision that aperture fastens and pitch relies on the precision of boring model and boring lever to assure, float join is between boring lever and main shaft, the precision of reason machine tool and treatment have nothing to do, can use the modular machine tool with common precision and taller productivity to come so essence of life bores hole is. This shows, often be when the treatment requirement of spare parts of short of of machine tool precision, adopt the method that the error changes, the machine tool that can use general precision machines the spare parts of high accuracy. 4, error in group law   is in treatment, as a result of the existence of error of process semifinished product, caused the machining error of this working procedure. The change of semifinished product error, basically have two kinds of cases to the influence of this working procedure: Answer reflect error of fixed position of sum of errors. If afore-mentioned errors are too big, unwarrantable treatment precision, and should raising semifinished product precision or on one working procedure to machine precision is wasteful. Can use an error at this moment in group law, it is semifinished product or dimension of foreword of go to work by error size cent namely N group, the error of every groups of semifinished product is contractible for original 1/n, the relative position that does not adjust cutting tool and workpiece by each constituent next or adjust fixed position component, can narrow greatly whole batch the dimension of workpiece is dispersive limits. For example, when some factory machines the commutative gear on gear grinder, encircle radial and jumpy precision requirement to achieve tine, will exchange gear inside hole size divides 3 groups, use to it the arbor of 3 groups of fixed position with relevant measure undertakes machining. Its in group measure is as follows (unit Mm) . Group fasten aperture of arbor diameter workpiece to cooperate precision ± of the first group of ~ 0.

± of the 2nd group of 002 ~ 0.

± of the 3rd group of 002 ~ 0.

002 ± 0.

Error of 003   in group the essence of the law, it is to use the inadequacy that raises the method that measures precision to make up for treatment precision, achieve higher precision demand thereby. Of course, measure, need to spend time in group, reason just is cooperating precision commonly very tall, and treatment precision is unfavorable when rising, use. 5, in   of method of treatment of on the spot is being machined and be being assembled, drag in of some precision problem arrives the correlation between a lot of component, quite complex. If raise spare parts precision purely to satisfy design requirement, sometimes not only difficult, achieve impossibly even. Right now, if use on the spot to machine a law, can solve this kind of difficult problem. For example, turning tower lathe is made in, turn on the tower 6 aperture that install cutting tool, its axes line must assure to rotate with machine tool main shaft central line coincide, and 6 plane must with rotate central line is perpendicular. If separate treatment turns,these aperture on the tower are mixed planar, afore-mentioned requirements should be being achieved when assembling is difficult, because included very complex dimension chain among them,concern. Used on the spot to machine a law in actual production consequently, before be being assembled namely, these important surfaces do not have precision work, etc turn after the tower assembles a machine tool to go up, go up to have precision work to these sky and plane in oneself machine tool again. Specific means is to be on machine tool main shaft lever of mount boring cutter and the small tool carrier that can become radial feed, have precision work to these surfaces, can achieve the precision of a need. Be like double housing planer, shaping machine again, the parallelism that holds the position with crossbeam or ram to make their workbench parts concerns, it is after assembling, go up in oneself machine tool, undertake finish machining of on the spot will achieve those who assemble a requirement. The workbench of planar grinder, also be essence of oneself emery wheel is used to grind after assemble those who come out. 6, the error is average law   error is average the law is to use be compared between the face that has close tie each other and amend each other, perhaps use each other to be fiducial undertake machining, in order to achieve very tall treatment precision. If cooperate the axis with precision very high demand and aperture, commonly used will achieve to grinding method. Alleged to grinding, it is a spouse axis and aperture each other are provided to grind relatively abrade. Ongoing there is certain abrade amount before grinding, the dimension precision demand of its itself is not high, in abrade process, cooperate the surface to grind relatively brush and tatty process, it is both error be compared each other and mutual amendatory process. Be like 3 a group standard flat, it is to use be opposite each other grind, match the methodological treatment that blow to come out. Can part because of 3 surfaces two two join closely, the ability below the condition that is accurate plane only is possible. Additionally still guide screw of body of compasses of straightedge, angle, much arris, standard waits for high accuracy measure and tool, it is to use an error average legal system is built come out. Pass above a few example are knowable, use an error average standard is OK the effect that utmost ground excludes machine tool error. CNC Milling CNC Machining