本文从保障我国食用植物油供给的高度，论述了发展油菜生产的重要意义；分析了我国油菜主产区——长江流域越冬油菜区生产的现状、特点，论述了分段收获与联合收获各自的优缺点，指出分段收获对我国油菜机械化收获的优越性和适应性。文章通过试验台测试了不同切割速度下的油菜茎秆的切割力、测试了三个品种的油菜角果的抗裂性。通过三个品种的小区对比试验，分析比较了一次收获与二次收获损失率与产量。在学习国内外有关经验和经过本人的试验观察，总结出油菜不同收获方式的收获时机判断的水分检测法和感观判别法。文章对齿带式捡拾收获机捡拾器做了运动学及动力学研究分析，得到捡拾弹齿的运动轨迹方程、速度方程，得到捡拾器倾角γ、速比λ的求解公式，进行了齿带式捡拾器的结构分析和被捡拾物料运动分析，得到捡拾阻力的求解公式。进行了捡拾器参数的试验研究，得到输送带速等参数与损失率的影响关系和优化组合参数。进行了分段收获油菜脱粒、清选参数的试验研究，得到滚筒型式、转速等参数与损失率的影响关系和优化组合参数。根据试验和优化的参数，对捡拾器、脱粒清选部件进行优化设计，研发了4SJ-1.8自走式捡拾收获机，并通过试验和法定检测，性能和实际作业效果良好。 通过分析、试验、研究，得到以下结论： 1.两次分段收获和联合收获两种收获方式的对比试验及分析得出分段收获的损失率低，实获产量高，产量增加的幅度因实验条件不同而变化。同时二次收获具有对作物状态适应性强，适收期长，便于籽粒储藏、秸秆还田、更早腾地（提早3-5天）等诸多优势，其缺点是机器两次下地，直接作业成本高于联合收获。 2. 通过试验研究和借鉴别人的经验，总结提出我国长江流域轮作油菜联合收获和分段收获的收获时机的感观判断和检测判断方法。 3. 对油菜分段收获捡拾收获机的捡拾器进行了捡拾作业运动学分析，得到捡拾弹齿的运动轨迹方程、速度方程，得到捡拾器倾角、速比λ的求解公式，并根据实际应用条件，给出确定倾角、速比λ具体数值时的参考公式： 和 。 4. 通过捡拾点弹齿的受力分析，得到捡拾阻力的大小和方向是随着捡拾点位置变化而变化的。 5. 分析了影响油菜机械化捡拾损失率的主要因素。利用有约束非线性优化理论对回归方程的设计参数进行优化。 6. 对我国长江流域油菜进行分段收获脱粒清选试验研究，得到夹带损失最小的优选组合为喂入量1.6kg/s、滚筒转速750r/min、脱粒间隙15mm、钉齿6排，影响脱粒分离夹带损失率的主次因素为滚筒形式、喂入量、脱粒间隙和滚筒转速。 7. 综合考虑清选损失率和含杂率最小的优选组合为A2B1C2D1，即冲孔筛Ø8mm筛孔、振动筛曲柄转速260r/min、离心风机转速860r/min、离心风机倾角15°；由模糊综合评价值的极差分析可得因素的主次排序为离心风机倾角、振动筛曲柄转速、振动筛形式、离心风机转速。 8. 喂入量、滚筒转速对功耗变化影响不显著，其主要原因是油菜茎秆经过几天的晾晒，含水率很低，易碎。 9. 依据捡拾器运动学分析结论、捡拾器参数试验、脱粒、清选的结果对捡拾器、脱粒滚筒、振动筛型式与组合进行优化设计，改进后的样机进行试验并经过法定机构检测，与改进前相比，捡拾台的损失率由原来的2.96%降低到2%，机体损失由改进前的2.36%（室内试验脱离和清选试验平均值）下降到1.2%。 文章的创新点和突出贡献在于： 1. 分段收获与联合收获模拟实验表明，分段收获的损失率、产量、适应性比联合收获好，这是分段收获在我国具有推广前景的证明。通过总结前人经验和本人的试验观察，得出不同收获方式油菜收获最佳时机的感观判断法和水分检测判断法。 2. 根据捡拾器的运动学分析并依据提高作业效率的原则，得出： 此两公式可以作为捡拾器参数选择的参考公式，对于齿带式捡拾器的设计具有指导作用。 3. 分析了影响油菜机械化捡拾损失率的主要因素：机组前进速度、输送带速和输送倾角三个因素，并得出了三个因素对损失率影响的回归方程的数学模型为：Y=2.96-0.35X1-0.011X2-0.01X3+0.38X1X2+0.63X1X3-0.6X2X3+0.84X12+0.97X22+0.62X32。 4. 对我国长江流域油菜进行分段收获脱粒清选试验和研究，得到夹带损失最小的优选组合为：喂入量1.6kg/s、滚筒转速750r/min、脱粒间隙15mm、钉齿6排。通过清选试验模糊综合评价值的极差分析，得到综合考虑清选损失率和含杂率最小的优选组合为：冲孔筛孔径Φ8mm、振动筛曲柄转速260r/min，离心风机转速860r/min，离心风机倾角15°。 5. 依据捡拾器运动学分析结论、捡拾器参数试验、脱粒、清选的结果对捡拾器、脱粒滚筒、振动筛型式与组合进行优化设计，改进后的样机进行试验并经过法定机构检测，表明性能指标有较大提高。此类履带自走式油菜捡拾收获机在我国首次研制成功，它的推广应用将会对我国油菜生产机械化发展有重要作用。

Oilseed rape is a important oilcrop that it has important significance for safeguard edible vegetable oil supplies to China. Oilseed rape production status and characteristics in main procuction region of China was investigated in the paper. The relative strengths and weaknesses with the direct harvest and two times harvest was discussed, pointed out that the two times mechanical harvest has the better superiorities and adaptabilities to oilseed rape in China in this study. Following contents were tested and studied in the paper: 1. Tested and studied oilseed rape stalk physics features, included: cutting forces test of stalks and against crack tests of siliques 2. Compared the yield and loss rate within direct harvest and two times harvest through experiments. 3. concluded and put forward to determine the method of oilseed rape harvest time with different harvest form. 4. Carried out kinematic and dynamics analysis of picker as well as parameter optimization for reducting loss rate of harvest. 5. Tooth-belt picker structural analysis and kinematic and dynamics analysis for picked up material and its analytical expression. 6. Experiment and researched on pickup parameters to get relatives of tooth-belt speed as well as else parameters between loss rate,and received optimal parameter combination. 7. Experiment and researched on oilseed rape shreshing and cleaning with two times harvest, to get affection relatives of cylinder style, cylinder speed as well as else parameters between loss rate,and received optimal parameter combination. 8. According to test and Optimal the parameters, the shreshing and cleaning devices were improved and the model 4SJ-1.8 pickup-combine were successfully developed.The performance experiments tests were finished by statutory inspection unit, which indicated that the machine has nicer performance characteristics and better operation effects. Received the following conclusions through analysis, experiments and research: 1. It was obtained from the contrast test and comparative analysis of the direct harvest and two stages harvest,that two stages harvest has follow advantages than direct harvest: the loss rate of belower, real yield higher, well-adapted to oilseed rape status during harvest, longer approprate harvest time, grain easy to store, stalk easy to grinde in field as fertilizer, earlier range of 3 to 5 days to empty out land for next crop, and so on.Its disadvantages are that the machine(swather and pickup)must operate twice in the same field, so the operation direct cost is higher than the direct harvest. 2. Through experiment, reseach and learnning the experences from others, the estimating methods of harvest opportunity of winter oilseed rape based on the appearance or the moisture were summarized in the paper. 3. Conducted kinematic analysis for the picker of the pickup-combine, following the results were received that is locus equation of the spring tooth movement, rate equation, solving formula for inclination angle  of picker and speed ratioλ,and according to realy conditions the formula which determined real numerical value of  andλwas derived: tg＝ctg -ｅ/sin,λ≥1/ cos.This formula has important reference value to design and use the picker. 4. It was Proved that pickup resistance direction is changing as pickup-point position shifting through force analysis of the pickup-point on the spring tooth. 5. The factors influencing loss rate in mechanical pickup were analyzed. The designedparameters of regression equation were optimized making use of constrained nonlinearity Principles of Optimization. 6. Optimal parameter group of which threshing separate of loss rate were is the lowest were 1.6kg/s feed quantity,750r/min roller rotating speed,15mm threshing interval and 6-pole spike-tooth cylinder,through the shreshing and cleaning tests with two time harvest to winter oilseed rape of yangtze valley. Primary and secondary factors of threshing separate smuggle loss rate were cylinder type, feed quantity, threshing interval and roller rotating speed. 7. The optimal parameter group of which cleaning loss rate was the lowest and impurity rate were the least were Ø8mm punched-hole sieve , 260r/min vibration sieve crank rotating speed, 860r/min centrifugal blower rotating speed and 15°centrifugal blower tilt angle. Primary and secondary factors by fuzzy analysis of synthesize evaluation were centrifugal blower tilt angle, vibration sieve crank rotating speed, vibration sieve type and centrifugal blower rotating by fuzzy analysis of synthesize evaluation. 8. Feed quantity and roller rotating speed indistinctively impacted power consumption . The reason lies in that the oilseed rape stalk have been air-cured for several days have got drying and cut up easily. 9. The picker,the shreshing cylinder and vibration sieve as well as their assembled were optimized according to kinematic analysis conclusions for the picker of the pickup-combine,parameter experement,shreshing and cleaning experemental results. Performance characteristics of modified prototype has been tested by Legal detect unit that is JiangSu Agricultural mechanical Test and VerificationTtation,it received results that is loss rate of picker reduced to 2% from previous 2.91%,the body loss rate(shreshing and cleaning loss) reduced to 1.2% from previous 2.36% that is laboratory experiment average value. 10. Successly developed model 4SJ-1.8 PSCC fill up the blank of pick up machine of oilseed rape two times harvest in our country, it comes up to international advanced level, it has a good prospect of application and extension. The innovations or contributions in the paper as bellow: 1. The experements of the direct harvest and two times harvest indicated that the two times harvest has follow advantages than direct harvest: the loss rate of belower, real yield higher, well-adapted than the direct harvest, and it demonstrated that the pattern of two times harvest for oilseed rape in our country has a good prospect of application and extension 2. According to the kinemathtic analasis and in order to promote the operation efficiency, following the fomula was derived: the two fomula should be used as reference fomula to choice the picker parameters,and be also used as advice to design toothbelt picker. 3. The paper analyzed the influence factors of loss rate in mechanical pickup that is forward velocity, the belt speed and the belt inclination, received the regression equation of the three factors impacted loss rate of pickup,that is : Y=2.96-0.35X1-0.011X2-0.01X3+0.38X1X2+0.63X1X3-0.6X2X3+0.84X12+0.97X22+0.62X32 4. Optimal parameter group of minimal loss rate of threshing separate were 1.6kg/s feed quantity,750r/min roller rotating speed,15mm threshing interval and 6-pole spike-tooth cylinder, which is used to winter rape harvest in yangtze valley. Primary and secondary factors of threshing separate synthetical loss rate were cylinder type, feed quantity, threshing interval and roller rotating speed. The results that is obtained by extreme variance analysis of fuzzy comprehensive evaluation were a optimal group of the cleaning parameters is Ø8mm punched-hole sieve , 260r/min vibration sieve crank rotating speed, 860r/min centrifugal blower rotating speed and 15°centrifugal blower tilt angle. 5. The picker , cylinder, vibration sieve type and combination were optimized ,and their structure design was improved according to the results of kinematic analysis and parameter of picker as well as shreshing and cleaning parameter experiments. The performance of the modified prototype were tested by Jiangsu Agricultural mechanical Test and Verification Station. It indicated that the performance should be greatly improved.