曲軸加工工藝優(yōu)化的分析與實(shí)施

1、. 曲軸加工工藝優(yōu)化的分析與實(shí)施 核心提示： 針對(duì)不同曲軸的淬火漲量不一致，工藝參數(shù)控制不統(tǒng)一及檢測(cè)手段受人為因素影響大的問(wèn)題，天潤(rùn)曲軸有限公司試驗(yàn)論證了一種新的加工工藝檔心距加工工藝。該工藝彌補(bǔ)了傳統(tǒng)的以止推檔側(cè)面為定位基準(zhǔn)的加工工藝缺陷，經(jīng)過(guò)換產(chǎn)和大批量生產(chǎn)的驗(yàn)證，不僅大大提高了產(chǎn)品質(zhì)量和效率，而且有效降低了不合格品率。在金融危機(jī)的影響下，汽車市場(chǎng)競(jìng)爭(zhēng)日趨激烈，汽車及零部件企業(yè)面臨嚴(yán)峻的挑戰(zhàn)，各大主機(jī)廠對(duì)曲軸的質(zhì)量和精度要求越來(lái)越嚴(yán)格。為了滿足客戶需求，我公司提出“以工藝為龍頭”的指導(dǎo)方針，要求改進(jìn)、優(yōu)化曲軸加工工藝，進(jìn)一步提升產(chǎn)品質(zhì)量和效率，提高客戶滿意度。通過(guò)對(duì)鍛鋼曲軸加工工藝進(jìn)行整體

2、優(yōu)化試驗(yàn)，不僅取得了良好的效果，提高了鍛鋼曲軸的產(chǎn)品質(zhì)量，同時(shí)還提高了生產(chǎn)線的產(chǎn)能，解決了產(chǎn)量與質(zhì)量此消彼長(zhǎng)的難題。曲軸加工現(xiàn)狀曲軸是發(fā)動(dòng)機(jī)的關(guān)鍵零件之一，其結(jié)構(gòu)復(fù)雜，生產(chǎn)批量大，品種更換頻繁，精度要求高。主軸連桿頸的尺寸精度為IT6IT7，圓度0.005mm，表面粗糙度Ra0.20.4。因此，一條先進(jìn)的曲軸生產(chǎn)線不僅要實(shí)現(xiàn)柔性換產(chǎn)以面對(duì)市場(chǎng)需求，還要滿足工藝要求，保證加工精度，最終生產(chǎn)出合格的產(chǎn)品。鍛鋼曲軸生產(chǎn)線擁有世界頂級(jí)的數(shù)控機(jī)床、先進(jìn)的加工工藝及日臻完善的管理制度，不僅大幅提升了曲軸的加工效率，實(shí)現(xiàn)了柔性快速換產(chǎn)能力，而且更好地保證了曲軸的加工質(zhì)量。當(dāng)前，曲軸的質(zhì)量主要通過(guò)機(jī)加工和熱處

3、理的過(guò)程控制來(lái)保證，其途徑大致有以下三種：1. 人為檢測(cè)：指通過(guò)專業(yè)質(zhì)檢人員（或操作人員自檢、互檢）對(duì)每道工序按照工藝要求進(jìn)行在線測(cè)量，及時(shí)調(diào)整工藝參數(shù)，避免不合格產(chǎn)品周轉(zhuǎn)到下道工序或出現(xiàn)批量廢品。2. 設(shè)備控制：指依靠較高設(shè)備精度保證當(dāng)前工序的加工精度，是保證尺寸精度、形狀精度和位置精度的有效方式，也是先進(jìn)曲軸加工生產(chǎn)線的標(biāo)志之一。3. 工藝保障：工藝是機(jī)加工過(guò)程中將曲軸毛坯轉(zhuǎn)化成成品的“法律”準(zhǔn)繩，是產(chǎn)品質(zhì)量的根本保證，也是提高加工效率的前提。對(duì)于上述三種提升產(chǎn)品質(zhì)量的途徑，我公司對(duì)各個(gè)生產(chǎn)線有針對(duì)性地進(jìn)行了試驗(yàn)論證。通過(guò)不斷地改進(jìn)我們發(fā)現(xiàn)：人為檢測(cè)相對(duì)難度較低，但是后期改善效果不明顯。通

4、過(guò)先進(jìn)設(shè)備控制加工精度已在鍛鋼生產(chǎn)線和部分鐵軸生產(chǎn)線上實(shí)施，改善效果可觀，但如果全公司普及需要投入大量資金。對(duì)于工藝保障，由于國(guó)內(nèi)外鍛鋼曲軸的加工工藝大同小異，且刀具、砂輪、切削液、淬火漲量、加工參數(shù)及加工余量等影響質(zhì)量因素涉及改善周期長(zhǎng)、優(yōu)化空間小及普及性差等特點(diǎn)，若通過(guò)工藝的改進(jìn)、優(yōu)化大幅度提高產(chǎn)品質(zhì)量難度無(wú)疑是最大的。 統(tǒng)籌分析加工工藝現(xiàn)場(chǎng)的加工工藝文件經(jīng)過(guò)一系列的改進(jìn)和優(yōu)化后，刀具材質(zhì)、加工參數(shù)、加工余量及工裝夾具的設(shè)計(jì)精度等影響加工質(zhì)量和加工效率的工藝參數(shù)已基本固化。當(dāng)設(shè)備具備相當(dāng)高的加工精度，每臺(tái)設(shè)備嚴(yán)格按照工藝進(jìn)行生產(chǎn)，卻無(wú)法保證加工過(guò)程中不會(huì)出現(xiàn)不合格產(chǎn)品時(shí)，我們往往認(rèn)為問(wèn)題在

5、于人為檢測(cè)不到位。實(shí)踐證明，加大人為檢測(cè)力度不僅增加了曲軸的制造成本，而且不能從根本上消除問(wèn)題。如何實(shí)現(xiàn)產(chǎn)品質(zhì)量提升需要對(duì)現(xiàn)行工藝進(jìn)行深入研究。通過(guò)對(duì)現(xiàn)場(chǎng)加工工藝的數(shù)據(jù)收集和整體分析我們發(fā)現(xiàn)：影響加工質(zhì)量、加工效率的主要因素集中在精磨主軸、連桿之前的工序，其具體問(wèn)題體現(xiàn)在以下四個(gè)方面：1. 由于頻繁換產(chǎn)，同一產(chǎn)品存在不同廠家、不同爐號(hào)的毛坯淬火漲量不一致的問(wèn)題，盡管漲量差距不大，也需要對(duì)整條生產(chǎn)線的機(jī)加工工藝參數(shù)進(jìn)行調(diào)整，影響了換產(chǎn)速度和換產(chǎn)質(zhì)量。2. 同一尺寸的不同工序?qū)に噮?shù)的控制不統(tǒng)一，增大了精磨主軸、連桿的加工余量，降低了精磨的加工效率。3. 依賴卡規(guī)、塞規(guī)等防錯(cuò)手段，具有人為因素影

6、響及檢測(cè)誤差大的缺點(diǎn)。4. 以止推檔側(cè)面為定位基準(zhǔn)，受刀具、砂輪磨耗及淬火漲量影響變化大，導(dǎo)致出現(xiàn)軸頸側(cè)面精磨磨不起來(lái)的現(xiàn)象。以止推檔側(cè)臺(tái)為基準(zhǔn)的加工工藝如圖1所示。上述問(wèn)題嚴(yán)重影響了鍛鋼曲軸生產(chǎn)線產(chǎn)品質(zhì)量的進(jìn)一步提升，必須徹底解決。解決方案針對(duì)不同曲軸的淬火漲量不一致，工藝參數(shù)控制不統(tǒng)一及檢測(cè)手段受人為因素影響大的問(wèn)題，我們?cè)囼?yàn)論證了一種新的加工工藝檔心距加工工藝。檔心距加工工藝是指主軸和連桿在機(jī)加工過(guò)程中始終以止推檔的中心線為基準(zhǔn)向其他各軸頸加工，加工后軸向尺寸為止推檔基準(zhǔn)線到各個(gè)軸頸中心線的距離。The analysis and implementation of crankshaft

7、machining process optimizationCore tip:, in view of the different crank quenching up quantity, process parameters do not have a unified control and detection means the problem of large affected by man-made factors, tianrun crankshaft co., LTD. Test demonstrates a kind of new processing technology -

8、gear pitch process. With thrust for the process to make up for the traditional gear profile for locating datum processing defects, after validation in production and mass production, not only greatly improve the product quality and efficiency, and effectively reduce the nonconforming rate.Under the

9、influence of the financial crisis, the increasingly fierce market competition, automobile and parts companies facing severe challenges, the makers and precision demand more and more strict in the quality of the crankshaft. In order to meet customer demand, our company put forward the technology as t

10、he leading guidelines to request improvement, optimization of crankshaft processing technology, to further improve product quality and efficiency, improve customer satisfaction. Through to the forged steel crankshaft processing whole optimization experiment was carried out, not only achieved good ef

11、fect, improve the product quality of forged steel crankshaft, it also enhances the capacity of production line, solve the production and quality related problems.The crankshaft machining status quoThe crankshaft is one of the key parts of the engine, and its structure is complex, the production batc

12、h is big, variety changed frequently, the high accuracy requirement. Size precision of the main shaft connecting rod journal for IT6 IT7, roundness 0.005 mm or less, the surface roughness Ra0.2 0.4. An advanced crankshaft production line, therefore, not only to achieve flexibility in production in o

13、rder to face the market demand, to meet the technological requirements, ensure the machining accuracy, the final production of qualified products. Forged steel crankshaft production line has the worlds leading CNC machine tools, advanced processing technology and perfect management system day by day

14、, not only greatly improved the crankshaft machining efficiency, realizes the flexible quickly in production capacity, and ensure the crankshaft better processing quality. At present, mainly through the quality of the crankshaft machining and heat treatment process control to ensure that its approac

15、h to roughly the following three:1. Detection of man-made: refers to by professional quality inspection personnel (or operator self-inspection, mutual inspection) online measuring for each working procedure shall be carried out in accordance with the technical requirements, timely adjust the process

16、 parameters, to avoid the unqualified products flow to the next working procedure, or a batch of waste.(2) device control refers to rely on higher accuracy guarantee machining accuracy of current process and equipment is to ensure that the size accuracy, the shape precision and position accuracy of

17、an effective way, also is one of the symbols of advanced processing production line of the crankshaft.3. The process security: is a machining process of crankshaft blank into a finished product legal criterion, is the fundamental guarantee of product quality, improve the processing efficiency of pre

18、mise.For the above three kinds of ways to improve the quality of the products, our company is targeted for each production line was tested. Through continuously improve we found: artificial detection relative difficulty is low, but later to improve the effect is not obvious. Through advanced equipment control machining accuracy have been forged steel production line a