Circle of radial of neck of crankshaft main shaft beats the experiment of the error studies

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Summary: Experiment through craft, the radial group of the generation in studying crankshaft is machining a process is jumpy error, the sort that uses craft catenary theory to analysed a law to analyse an error and genetic pattern: Put forward to reduce finally by radial of cheek of axial main shaft the circle is beaten the measure of the error. In machining, as a result of the complexity of machining complex, often determine the systematic impact to machining precision very hard from the physical property of machining complex itself. Although a few relation can be established below certain and special situation, but these relation derive below Utopian condition, because this is most,the circumstance tries through the experiment hard test and verify. The element that machines quality considering the influence in machining a process actually is numerous, and cannot know or having a lot of factors cannot accuse, at this moment we might as well come to machining complex as a whole look upon, study the systematic effect to machining quality from whole. Can regard the error of around of spare parts treatment as systematic input and output right now, throw the research of internal to the system composition completely, and regard machining complex as " black box " will handle. This is derivative the basic theory of craft catenary. So-called technology catenary, it is to make workpiece obtains surface roughness of precision of certain measure, appearance, position, surface and a chain of process that completes below workpiece, to each working procedure, what what we care is the relation between output error value and input error value. In craft catenary, the output error of before one working procedure is hind the input error of one working procedure, and whole craft catenary will input an error to turn into through every working procedure output error, reduce error cost step by step, make its reach the error range of a requirement finally. Crankshaft is engine in one of important parts, its enlist in army ambient conditions is poorer. According to effective demand, divide the public errand such as pair of dimension to put forward relatively outside high accuracy requirement, the radial round jumpy error that returns pair of main shaft necks raised very tall requirement, if the graph is shown 1 times, jumpy allow difference is 0.

03mm, however from inside producing practice we discover, because crankshaft is longer, oneself weight is greater, plus crankshaft " labyrinthian sex " , because this is rigid poorer. Flexibility of easy in machining a process generation bends, radial circle is jumpy when bringing about treatment out of tolerance. Additional, crankshaft is changed in nitrogen during, because furnace temperature is higher (570 ℃ ± 5 ℃ ) , and heat preservation time is longer (6 hours of or so) , easy also generation bends be out of shape, bring about crankshaft radial round jumpy out of tolerance. Graph 1 crankshaft diagram (495Q) the lead plane property that round jumpy out of tolerance meets crankshaft radial affect engine badly, of aggravate journal wear away, cause loss of plain bearing liner, make finally spare parts invalidation. Producing at present actual in, the crankshaft one by one after be being changed to nitrogen measures radial of main shaft neck jumpy value, the error is in 0.

The adoption of 05mm above is cold the method of alignment will amend. Bigger to jumpy quantity crankshaft allows alignment twice. After crankshaft nitrogen changes, cold alignment puts in apparent inadequacy: It is the stress concentration with cold alignment larger presence (although via ageing treatment also cannot) of complete purify stress, force and hot action suffer to will restore radial to be out of shape when the job inside engine; 2 it is the fatigue intensity that cold alignment reduced crankshaft. Carry out a proof, crankshaft cold alignment is one of main reasons that cause engine to break an axis. Domestic and international the home already set a lot of engine manufacturers not to allow or be opposite less as far as possible crankshaft undertakes cold alignment. Below this kind of circumstance, the radial round jumpy error that how is research controlled and reduces crankshaft to arise in the place in machining a process, to raising the real significance with lengthen service life to have crankshaft quality, important. 1 crankshaft radial is round the experiment of jumpy error and analytic basis craft catenary is academic, to each working procedure in craft catenary, there is linear and relevant relation mostly between output and input error. To working procedure of N line, the relation between Eoj of its output error and input error Eij can express as Eoj=hjeij+ej(1) the radial circle after to crankshaft working procedure of N line machines beats the error can adapt in type of J(2) of → of Ij+d of → of D of × of D → Oj=hj: The radial circle after D → Oj is machined for working procedure of N line is jumpy error; The partial error of this working procedure of Ij of → of Hj × D, among them Hj is genetic coefficient; The radial circle that this working procedure oneself generates for D → J is jumpy error. The type that beats to as radial as crankshaft circle a few working procedure with influential error do error of craft experiment, analysis to arise below reachs genetic kind. Experiment condition with 495Q crankshaft (graph 1) regards an experiment as the object, the choice does craft to experiment in manufacturing site, so that data more joint production is actual. Crankshaft radial circle beats error numerical value all is the measured value of neck of the 3rd main shaft. Test result and cent are expressed 1 it is right radial of around of neck of main shaft of vehicle of 20 crankshaft fine is round the measured value of jumpy error size and direction. The error before fine vehicle is the diameter in the car (neck of the 3rd main shaft) output an error. By the watch 1 can see: Circle of radial of the crankshaft after neck of fine vehicle main shaft beats the error increases on the whole, round jumpy error has the crankshaft radial after this shows this working procedure already on the heredity of line working procedure, have the error that working procedure itself produces again. Watch 2 it is right crankshaft differ in roll end diameter undertakes radial of fine vehicle around the measured value of round jumpy error. The error before fine vehicle is the output error of neck of fine vehicle main shaft. By the watch 2 can see: The size of error of around of this working procedure and direction basically did not produce what change, after this working procedure is machined, this specification did not produce new error, and on almost all heredity went to the error of line working procedure this working procedure. Express radial of around of neck of main shaft of vehicle of 1 crankshaft fine round jumpy error (1599050945*0 of the error after vehicle of fine of the error before vehicle of fine of date of casting of crankshaft of Mm) serial number.

1525 ° 0.

2560 ° 25990508410.

2040 ° 0.

2770 ° 35990508630.

1755 ° 0.

2375 ° 45990508610.

25120 ° 0.

3480 ° 55990507420.

30120 ° 0.

38110 ° 65990511460.

2870 ° 0.

2370 ° 75990507610.

3520 ° 0.

4540 ° 85990508430.

3960 ° 0.

42105 ° 95990511590.

37300 ° 0.

45210 ° 105990510470.

38105 ° 0.

4285 ° 115990508440.

4175 ° 0.

4535 ° 125990506420.

27175 ° 0.

3565 ° 135990511420.

29340 ° 0.

37190 ° 145990512470.

32120 ° 0.

3960 ° 155990511710.

38195 ° 0.

4585 ° 165990511730.

3170 ° 0.

2570 ° 175990508640.

27230 ° 0.

3970 ° 185990508620.

10255 ° 0.

2530 ° 195990510460.

21290 ° 0.

31170 ° 205990509270.

1850 ° 0.

2510 ° note: * : Casting date 599050945 departments casting 5 on May 8, 1999 place casting the 5th crankshaft in the 4th packet of molten iron; Angle of the suffix in the watch is to show jumpy the greatest numerical value is in the position. Express radial of around of differ in roll end diameter of vehicle of 2 crankshaft fine to encircle jumpy error (the error after vehicle of fine of the error before vehicle of fine of date of casting of crankshaft of Mm) serial number 15990508450.

2560 ° 0.

2560 ° 25990508410.

2770 ° 0.

2670 ° 35990508630.

2375 ° 0.

2375 ° 45990508610.

3480 ° 0.

3580 ° 55990507420.

38110 ° 0.

38110 ° 659905011460.

2370 ° 0.

2370 ° 75990507610.

4540 ° 0.

4540 ° 85990508430.

42105 ° 0.

41105 ° 95990511590.

45210 ° 0.

45210 ° 105990510470.

4265 ° 0.

4285 ° 115990508440.

4535 ° 0.

4535 ° 125990506420.

3565 ° 0.

3565 ° 135990511420.

37190 ° 0.

37190 ° 145990512470.

3960 ° 0.

4060 ° 155990511710.

4585 ° 0.

4585 ° 165990511730.

2570 ° 0.

2570 ° 175990508640.

3970 ° 0.

3970 ° 185990508620.

2530 ° 0.

2530 ° 195990510460.

31170 ° 0.

30170 ° 205990509270.

2510 ° 0.

What 2510 ° graph shows 2 times is radial of crankshaft of around of neck of kibble main shaft the metabolic circumstance of round jumpy error. By the graph 2 knowable: Around of neck of kibble main shaft. Crankshaft radial circle beats error value produced very big change (experiment proof, error direction also produced) of very big change. Find out through anatomize: Basic an ancient type of spoon eliminated neck of kibble main shaft to go up the radial circle of working procedure is jumpy error, its have the error is generation of oneself machining complex. Graph the radial circle of around of neck of 2 kibble main shaft beats the error pursues the radial circle that 3 essence grind around of main shaft neck beats the error pursues 3 it is essence of life grind around of main shaft neck, crankshaft radial is round jumpy error circumstance. By the graph knowable, its type is the same as the C on the experiment. Graph the error with the radial jumpy circle that 4 nitrogen change from beginning to end pursues 4 it is crankshaft nitrogen changes from beginning to end, its are radial the metabolic circumstance of round jumpy error. By the graph 4 knowable: The crankshaft radial circle after nitrogen is changed beats the error basically increases, and individual change range is bigger. Find out via serious analysis: The crankshaft radial after nitrogen is changed is round jumpy error, have already on the heredity of line working procedure, have the new error that working procedure itself produces again, and new error takes dominant effect. Experiment summary passes pair of crankshaft the test result of a few crucial working procedure makes clear, among them a lot of working procedure and crankshaft radial circle beat the error is concerned, and the influence level that different process place creates is different, can divide commonly for the following 3 kinds: The first kind: Type (the D → J=0 in 2) , namely Ij of → of D of × of D → Oj=hj. Namely the radial round jumpy error after crankshaft is machined via this working procedure to go up the heredity of working procedure error, its size depends on on the error value of line working procedure and genetic coefficient Hj, and working procedure itself does not produce an error. Experiment B attributes this kind of situation, among them Hj=1. The 2nd kind: Type (the Ij=0 of → of Hj × D in 2) , namely J of → of D → Oj=d. After crankshaft is machined via this working procedure, basically eliminated namely on the radial circle that line working procedure generates is jumpy error, have very strong error corrective ability. At the same time itself produced new error watt, be in usually Ij of → of D → J<d. Experiment C, D attributes this kind of situation. The 3rd kind: J of → of Ij+d of → of D of × of D → Oj=hj. Namely the radial round jumpy error after crankshaft is machined via this working procedure has already on the heredity of error of line working procedure, have the error that body of working procedure wood produces again. Experiment A, E attributes this kind of situation. Carry out a proof, below great majority circumstance, the oneself the error always is more than on one working procedure genetic error of whole process. Because this should focus attention to the free error of process. Because genetic coefficient is enraged,always be less than normally again 1. In have an error oneself in, it is the working procedure from the back more, to end product the influence heals big. Accordingly, reduce crankshaft radial circle to beat the key of the error depends on reducing finally a few working procedure (if essence of life grinds main shaft neck, nitrogen,change wait for working procedure) have an error oneself. 2 reduce crankshaft radial circle to beat the measure of the error experiments according to above process and analytic result are knowable: Should reduce crankshaft radial as far as possible round jumpy error, raising essence of life to grind the treatment precision of working procedure of main shaft neck, strict nitrogen to change operating rules is the key that solves a problem. Emery wheel is ground blunt or the bits that be ground jams reach grinder tip to adjust force undeserved also be to cause crankshaft radial the element of round jumpy out of tolerance. The method that raises essence of life to grind main shaft neck to machine precision has (here points to the problem) that solves crankshaft radial circle to beat only: Wear the diameter in grinding of the crankshaft that prop up with mechanical center opening type. The edge answers to so that can be eliminated,adjust edge grinding when grinding in front on the jumpy error of foreword. Additional, the precision that raises main shaft of head, rear push frame also is reduce crankshaft radial the important step of round jumpy error. Emery wheel is ground blunt or if be amended not in time,the bits that be ground jams, grinding force can be brought about to increase to drop with exterior quality when grinding crankshaft (wait for) like burn, round jumpy error increases journal radial subsequently. Production carries out a proof, when essence of life grinds 4 abduct crankshaft, every grinding must amend emery wheel when two crankshaft. Only such ability maintain good grinding performance, the crankshaft radial after reducing grinding is round jumpy error. The experiment proves, the size that grinder tip carries close force on the head is right also radial of the crankshaft after grinding is round jumpy error is influential. Aborning can take the volume that tries the method that grind to adjust top top to tighten force. Because nitrogen changes the crankshaft radial circle that bends to be out of shape and cause to beat the measure of out of tolerance has,reduce: Reasonable outfit furnace. Crankshaft is long axis kind spare parts, the means that perpendicular condole hangs can be used when nitrogen is changed, make its are in nature to loosen condition. If use tray to install crankshaft, must make crankshaft is in verticality, removed 40mm above, the crankshaft when preventing nitrogen to change is askew and generation bends be out of shape. The operation is turned in nitrogen in, slow warm up and warming up equably is it is important to reduce and prevent to curve metabolic one annulus. If warm up rate is too rapid, certainly will causes temperature of the side outside the crankshaft that stands by retort temperature of tall, inside is low, because two side put crankshaft,be in so difference in temperature, make use of condition will surely arise bend be out of shape. In neck of fine vehicle main shaft and fine vehicle connecting rod considering crankshaft the cutting when the neck is measured big, cause bigger stress concentration easily. Can consider to undertake 2 times going to crankshaft after this working procedure stress temper, bend when nitrogen is changed so be out of shape a few smaller. We had done test of this kind of craft to 6 abduct crankshaft, the nitrogen of result crankshaft changes deflection to be reduced apparently. In addition, cast internal stress and normalizing stress to also not allow to ignore to what crankshaft semifinished product exists, it also is to cause crankshaft to curve one of metabolic elements in machining a process. Should adopt to semifinished product go a series of working procedure measure such as stress temper, oscillatory effectiveness for a given period of time. 3 last words are narrated on put together, the radial circle that with craft catenary theory analytic law analyses crankshaft to arise in machining a process beats the error has certain law but abide. Use this one law but the origin of error of each working procedure reachs hunting the genetic concern of working procedure around, take significant craft step in producing practice then, be controlled in order to achieve and reduce crankshaft radial the purpose of round jumpy error. CNC Milling CNC Machining