CN85103641A

CN85103641A - Absolute coordinates error compensation processing method

Info

Publication number: CN85103641A
Application number: CN 85103641
Authority: CN
Inventors: 关学成; 刘树琪
Original assignee: Tianjin University
Current assignee: Tianjin University
Priority date: 1985-05-28
Filing date: 1985-05-28
Publication date: 1986-04-10
Also published as: CN85103641B

Abstract

Absolute coordinates error compensation processing method belongs to metal-cutting machining method.

A kind of processing method that adopts absolute coordinates error compensation principle.Pivot with workpiece is the tool setting benchmark.Point of a knife absolute coordinates position correction device and displacement numeric display unit are formed point of a knife absolute coordinates position measuring system.Adopt processing conditions homogeneity principle that mismachining tolerance is compensated.Adopt this method can improve the workpiece accurate to dimension, save man-hour, reduce waste product.This method is grasped easily, can be applied to the transformation of refining of engine lathe class lathe, will receive tangible economic effect.

Description

Absolute coordinates error compensation processing method

The invention belongs to metal-cutting machining method.

Manual operations adds man-hour in jobbing work, and the workpiece size precision is realized with traditional processing method-trial cut feed processing method on universal machine tools by the operator.Adopt this processing method, the workpiece size precision mainly relies on operator's experience and technical ability control.Be difficult to realize the automatic control of precision, labour intensity is big, and unproductive time is long, and productivity ratio is low, the percent defective height.

The Hangzhou Steel Company equipment Chen Riyong of place installs " accurate tool setting locator " and least count on four meters vertical lathes be 0.01 millimeter the automatic measuring workpieces size of the synchronous device for digit-displaying of induction, is implemented in that the processing inside and outside circle can be worked into size with workpiece without measurer on the vertical lathe.But tool setting positioner mechanisms link is more, and the cumulative measurement error is bigger, and certainty of measurement is lower, and especially processing then seems impracticable for high-precision workpiece.

For overcoming the deficiency of above-mentioned processing method, can adopt the alleged absolute coordinates error compensation processing method of the present invention.

The main distinction of absolute coordinates error compensation processing method and trial cut feed processing method is that the benchmark of position of tool tip adjustment (feed) no longer is a surface of the work to be processed, but the machining benchmark of workpiece-be lathe spindle rotation centerline O-O.Be not the nominal cutting-in of control during operator's feed, but the control point of a knife is to the passive distance of machining benchmark.

Fig. 1 is an absolute coordinates benchmark schematic diagram.R ^oFor point of a knife to machining benchmark O-O passive distance; R is the real radius size after the part processing; △ R is a process system dynamic dimension variable quantity, is commonly called as relieving amount; O-O is a machining benchmark.

Position of tool tip error compensation schematic diagram when Fig. 2 is whole feed.R ^o _N-1Point of a knife is to the passive distance of machining benchmark when being the n-1 time feed; R _N-1Be odd-job part radius size measured after n-1 the feed; △ R _N-1It is the dynamic dimension variable quantity that records after the n-1 feed; R ^o _nPoint of a knife is to the passive distance of machining benchmark, R during for whole feed _MaxBe half lower limit of part tolerance band, R _MaxBe half the high limit of size of part tolerance band; △ R _nThe error compensation amount of position of tool tip during for whole feed; R _nNominal dimension for part.

Fig. 3 is a point of a knife absolute coordinates position correction device structural representation.Sample post 1, spring leaf 2, body 3, spring 4, screw 5.

Fig. 4 is displacement numeric display unit scheme of installation on lathe.Middle carriage 1, saddle 2, displacement signal generator scale 3, displacement signal generator slide rule 4, squaring head 5, numeric display unit 6, cutter 7, point of a knife absolute coordinates position correction device 8.

The present invention adopts absolute coordinates error compensation processing method, guarantees the dimensional accuracy of processing parts.See Fig. 1, with the passive distance R of point of a knife to machining benchmark ^oFor radius processing back, workpiece size may be greater than or less than R ^o, i.e. △ R=R-R ^oIf the operator can predict the size and Orientation of △ R numerical value before feed, in the time of then can before whole feed, regulating the tool position to whole feed △ R _nCompensated, reached the purpose of control workpiece size precision.But △ R value is subjected to the kinds of processes factor affecting, is difficult to accurate Calculation.For this reason, this method adopts the processing conditions identifiability principle to compensate, i.e. the dynamic dimension variable quantity △ R that obtains in the past one-pass _N-1Regulate the compensation rate △ R of point of a knife coordinate position during as whole feed _n, make △ R _n≈ △ R _N-1, see Fig. 2.For guaranteeing △ R _n=△ R _N-1The homogeneity of processing conditions in the time of then must guaranteeing twice feed, promptly on same chassis bed, with same cutter, with identical cutting data, process the same surface of same workpiece, and make minimum blanking time of twice feed as far as possible, should widely different commentaries on classics squaring head between twice feed.

Point of a knife is to machining benchmark passive distance R during whole feed ^o _nRegulated quantity be calculated as follows, referring to each size among Fig. 2.

The n time feed and the n-1 time feed keep homogeneity, and △ R is then arranged _n=△ R _N-1, and R ^o _n=R _n-△ R _n

R _nPress R _n=1/2 (R _Max+ R _Min) calculate.

R then ^o _n=1/2 (R _Max+ R _Min)-△ R _N-1And by this value adjustment position of tool tip.When the workpiece form error is big, to R ^o _nRevise.

Absolute coordinates error compensation processing method determines that point of a knife absolute coordinates position is with the point of a knife absolute coordinates position correction device that is installed in lathe scroll chuck (or be bearing in two top between), and is equipped with that the displacement numeric display unit realizes.The structure of point of a knife absolute coordinates position correction device is seen Fig. 3, it is made up of body 3, sample post 1, spring leaf 2, spring 4, screw 5, be shaped on the radial hole vertical on the body 3 with the body center line, sample post 1 is metal Cylinder, sample post 1 places the radial hole of body 3, and can in the hole, move, system one plane on the total length of garden cylinder outside sample post 1, this plane contacts with

spring leaf

2,2 pairs of sample posts 1 of spring leaf impose certain thrust, in order to eliminate the gap between sample post and body radial hole surface.The thrust of spring leaf 2 can be regulated by screw 5 and spring 4.Will be after sample post and the body assembling through correct grinding, to guarantee the precision of point of a knife absolute coordinates position correction.Point of a knife absolute coordinates position correction device is installed on after the lathe scroll chuck, is used for amesdial and proofreaies and correct sample post two terminal circle cylinder, and the widely different commentaries on classics of its symmetrical centre and lathe spindle center is overlapped.Carry out the adjustment of point of a knife absolute coordinates position then.Round metal cylinder after the also available fine finishining of point of a knife absolute coordinates position correction device replaces.

Point of a knife absolute coordinates position is measured with the displacement numeric display unit and is shown.Displacement numeric display unit installation site is seen shown in Figure 4.Displacement signal generator scale 3 is loaded on lathe saddle 2, and slide rule 4 is contained on the middle carriage 1, and numeric display unit 6 accuracies of reading are 0.001 millimeter.After point of a knife absolute coordinates position correction device 8 was installed and proofreaied and correct, middle carriage 1 drives squaring head 5 and cutter 7 moves, and the point of a knife of cutter 7 is contacted with the sample post of point of a knife absolute coordinates adjuster, and then point of a knife to the passive distance of workpiece machining benchmark is R ^o, numeric display unit is pressed R ^oPut number.

For avoiding frequently proofreading point of a knife absolute coordinates position, reduce unproductive time, this method also adopts the cutter pre-regulating technology.Be equipped with on squaring head 5 and the corresponding locating surface b of cutter afterbody, cutter pre-regulating length is fixed length L _ToThe length adjustment of preset tool can be carried out on the tool setting gauge outside machine.

The position of tool tip of other cutter on the squaring head 5 is also proofreaied and correct once, makes every the identical coordinate values y of the widely different commentaries on classics of the relative knife rest center, absolute coordinates position of cutter point of a knife maintenance.

The check and correction of cutter position of tool tip finishes, and unloads point of a knife absolute coordinates position correction device, workpiece is installed is processed.

Adopt this processing method, inner and outer round surface that can processing work, dimensional accuracy obviously improves than trial cut feed processing method precision, and stable accuracy, can save 50% of unproductive time, alleviate labor strength, boost productivity, the rate of reducing the number of rejects and seconds, the workman who is easy to common grade grasps. This method only needs that installation position shift word display unit and point of a knife absolute coordinates position correction device can realize that the investment short-term can reclaim on engine lathe class lathe. Be applicable to particularly that to the technological transformation of refining of existing lathe obvious economic benefit and practical value are arranged.

Claims

1, a kind of displacement numeric display unit that is installed on the engine lathe is used to measure the method for point of a knife absolute coordinates position and processing column face.It is characterized in that the adjustment benchmark of point of a knife coordinate position is the lathe spindle rotation centerline, whole feed and last time feed use samely cutter, cutting data is identical, the time interval between twice feed is little, other processing conditions is respective fixation also.

2,, it is characterized in that resulting dynamic dimension variable quantity △ R during one-pass before utilizing by the said processing method of claim 1 _N-1Adjust the compensation rate △ R of point of a knife absolute coordinates position during as whole feed _nPoint of a knife is to the passive distance R of machining benchmark during whole feed ^o _nUse formula

R ⁰ _n=1/2 (R _Max+ R _Min)-△ R _N-1Calculate.

Calculate R ^o _nThe time to consider the influence of workpiece form error.

By the said processing method of claim 1, it is characterized in that 3, the adjustment of point of a knife absolute coordinates position is to realize with the point of a knife absolute coordinates position correction device that is installed in (or being bearing in two top) on the lathe scroll chuck.This adjuster is constituted by body, spring, screw with along the sample post that intrinsic radial hole moves.

4, by the said point of a knife absolute coordinates of claim 3 position correction device, it is characterized in that along being shaped on and the contacted plane of spring leaf on the metal sample post periphery total length.