Thin wall semicircle treatment is out of shape with countermeasure

5 ～ 1mm, if pursue,2 are shown. When be being assembled consequently, the spare parts must pass long file, but the spare parts after repairing file does not accord with a design to ask. Investigate its reason, it is the spare parts is out of shape be caused by. Graph semicircle of 1 thin wall graph 2 sliver port contracts upcountry 2, the internal stress be caused by that the reason that is out of shape case study produces this kind of error basically is a spare parts. And heat treatment and turning cause internal stress. In heat treatment, spare parts classics heats, warm up to be controlled to 780 ℃ , again classics is fast and cooling (water-cooling) with 550 ～ temper of 600 ℃ high temperature, the shift that completes pair of parts is simple. This shows, in moving simple procedure, hot → of hot → cold → is cold, spare parts be heated expands, encounter cold systole. Be like spare parts structure irregular, thickness is differ, the cold hot degree that gets, heat bilges cold the degree that shrink and be heated and cooling rate are differ. Heat of mural small part bilges fast, cold shrink fast also; Heat of mural large part bilges slow, cold shrink slow also. This kind of rate is poor, the intermediate zone that can be in the large part of the spare parts and small part forms the internal stress of interaction inside region. Internal stress is in interior of the spare parts that make a circle is mutual balance. After be being dissectioned when the spare parts, internal stress is about to seek new balance. Such, the spare parts can happen be out of shape, and metabolic size, with its stiffness is concerned. Stiffness is out of shape greatly small. To Bao Bi be out of shape bigger. Because this spare parts has a paragraph of large wall among its, after heat treatment is cooling, intermediate part cooling rate is slow, in its small part of two end wall, temperature already was reduced, and intermediate part still contracts in refrigeration, criterion in two end wall small part generation presses stress, if pursue,3 are shown. Graph canister of 3 thin walls suffers vehicle of power position fine and milling to also can produce internal stress, heat in metal cutting is caused, opposite for lesser, be out of shape to the spare parts the impact is not big. As to clamping force, also can arise be out of shape, but basically be circularity precision suffer an effect, not big to influence of spare parts mouth. So, after the spare parts is opened by mill, its press stress when seeking new balance, make spare parts mouth is in generation to shrink buccal phenomenon. Generation shrinks this kind the internal stress that the mouth is out of shape the main reason of the error is heat treatment generation. 3, the method that solves a problem wants to solve this problem, be about from eliminate internal stress to begin. A kind of method is ageing treatment has work after heat treatment. Another kind of method is to dissection first, reheat is handled, machine two spot welding together next. These two kinds of method, course of before one kind of craft is changeless, just add working procedure of a effectiveness for a given period of time, because ageing treatment internal stress is impossible to be eliminated completely, reason can decrease only be out of shape, but cannot eliminate completely be out of shape. Course of a kind of craft should undertake comparative big change after. But this kind of method is eliminated effectively be out of shape error. Now expatiatory hind a kind of method. Craft course instead: Whole round thick vehicle (stay have more surplus) → mill (apart) spot welding of → heat treatment → (amalgamative) half essence of → car → clamp (apart) → is ground. This kind alters the key depends on dissectioning first, reheat is handled. When such heat treatment, workpiece can be out of shape adequately. Because its appearance is a semicircle,this is, is not full circle, in internal stress already was out of shape because of the spare parts and can decrease at this moment a lot of. And, when sequel is machined, just measure the others purify, itself structure is not made change greatly (unlike rectifies round incision) so, reason the balance of its internal stress also won't be broken, won't cause because of internal stress again be out of shape. After heat treatment, be together two in the spot welding below free condition again (synthesize a round) , if pursue,4 are shown. After spot welding, solder contact place can have welding stress. Because be contractive after solder, reason is in existence to have in solder dot pull stress. And the part of two end thin wall of the spare parts still can exist press stress certainly, both and OK a few quitser, make welding stress won't have what effect to the spare parts thereby. After the turning of spare parts classics with good solder is machined, weld only remnant is a bit more very few welding line, the spare parts is broken with the hand, can part, divide analyse the face to burnish again, attainable complete qualification (mouth place is not had basically be out of shape) spare parts. If want some more careful, can add working procedure of a effectiveness for a given period of time again after spot welding, the effect will be better. Namely: → of clamp of → of half fine vehicle grinds → of effectiveness for a given period of time of → of spot welding of heat treatment → of → of mill of → of thick car full circle. Graph of annulus of 4 two semicircle solder the place on put together is narrated, to this spare parts, basically used two syncretic and the method of the heat treatment after parting first on craft, solved treatment problem and be out of shape problem. Accordingly, solve Bao Bi, semicircle treatment problem, need to try to analyse according to different situation, can find an appropriate craft line. Of course, the craft line that article place introduces is a few more complex, if spare parts demand is not high, might as well use process of effectiveness for a given period of time, can economy a few. CNC Milling CNC Machining