On the foundation that detects to airframe internal stress, reaching airframe has greater internal stress after rough machining is airframe the metabolic in after foreword is machined and be being used is main reason, because this needs,have ageing treatment 2 times. But undertake heating up effectiveness for a given period of time again after rough machining, be sure to cause airframe to be out of shape out of tolerance, destroy treatment the face is bright and clean degree. Analyse a proof through checking data, oscillatory ageing treatment increasing to regard effectiveness for a given period of time as 2 times craft after airframe rough machining is feasible. The test case that shows will oscillatory ageing treatment reports as follows: 1. This second experiment chose oscillatory aging equipment to develop limited company and college of Dalian grain industry to be developed jointly by science and technology of effectiveness for a given period of time of vibration of Dalian annulus eaves " intelligence vibration eliminates stress system " will handle airframe, it is home's at present advanced new product, automation rate is high, whole processing reachs craft to be finished automatically after technology is certain. 2. After airframe vibration aging test uses a rough machining first, discard airframe (16D0033 date airframe) undertake in advance experiment gathers data, the airframe after two rough machining is reoccupy test specimen; The first moves parameter of technology of effectiveness for a given period of time to choose with Yu Zhen (strong point, stimulate brace up prejudicial grade level, Shi Zhen nods dot, vibrator, stimulate Zhen Pin rate, sweep highest frequency) , via undertaking stress detects after vibration, observe oscillatory effectiveness for a given period of time removes the effect of stress. The 2nd is used at optimizing parameter of oscillatory effectiveness for a given period of time, observe the stability of parameter of the first oscillatory effectiveness for a given period of time, decide procedure of oscillatory effectiveness for a given period of time finally. 3. Airframe of the first diesel engine (airframe headstock date: 2001, 063) oscillatory ageing treatment (1) the hand uses operating sequence: ① establishs airframe put on flat, do propped up at 3 o'clock: Prop up among a side face a bit, another flank was propped up at 2 o'clock, all be stay with thick rubber mat. ② general vibrator (A) outfit card is in right roof 7, between 8 crocks of Kong Zhi, adjust prejudicial for second gear. ③ sucks Shi Zhenqi the upright ministry that standing by aperture of a crock part of right roof part. ④ join electric machinery - control box, shi Zhenqi - the line is connected between control box. ⑤ join power supply cord. ⑥ hand adjusts electric machinery rotate speed handles 30min to 4200r/min vibration. ⑦ vibration processing records the value of a quantity that acceleration index changes along with time at the same time. (2) automata ① spot is decorated with " the hand uses operating sequence " ② of ⑤ of ④ of ① ② ③ sweep highest value is in surely 4500r/min. ③ is finished automatically by process of automatic processing Niu Houquan. Processing curve sees a picture 1, graph 2. Graph 1nextpage pursues 2 (3) craft effect detects ① by the graph 1, graph 2 in seeing vibration handles a process, zun Yifeng is worth frequency character curve rise, time, amplitude curve by rise to change gradually smooth, accord with requirement of national level JB/T5926-98 completely. ② test makes clear, brace up hind leftover stress is reduced generally and leveling, but stress total level falls rate have 21 only.
6 ％ under national level (JB/T5926-98) medium concerned regulation. ③ conclusion: Craft is accorded with basically, but need to increase stimulate brace up force. 4. The 2nd airframe (airframe headstock date: 96-098) oscillatory ageing treatment (1) the oscillatory ageing treatment of the 2nd airframe differs with the first at at 2 o'clock: B of instead of ① general A vibrator, stimulate in order to increase brace up force. ② will be stimulated brace up dot choosing has a test in two place, it is for the first time namely between 1~2 crock aperture, it is the 2nd between 7~8 crock aperture, it is vibration 2 times namely. Other parameter is changeless. (2) craft effect detects ① frequency character curve and time, amplitude curve change is normal. ② is seen by next watches, brace up hind leftover stress drops generally, and total stress level falls 40 ％ above, accord with national level completely already (JB/T5926-98) requirement. ③ conclusion: Place of the 2nd airframe uses parameter of craft of oscillatory effectiveness for a given period of time the choice is logical, can use at production. Stress of remains of effectiveness for a given period of time of vibration of rough machining airframe detects MPa of data table unit (airframe headstock cast number: 96-098) 1 σ of the σ that order number 1 σ of 2- σ 2- - eliminate after Zhen Qianzhen rate % rate %2260 is eliminated after Zhen Qianzhen.
26 average stress 266.
48 CNC Milling