【正文】 s product is equipped with a device, but does not accord with a standard to ask more. As a result of the existence of these problems, a lot of hidden trouble, the safety of users to farmers accident also occur frequently. In 1997, for example, produced by a factory in hebei corn sheller with no preparation
。 3 there is a considerable number of small firms, in particular, some new horse township, individual enterprises, due to the production conditions, the personnel quality and internal management is poorer, raw materials and ponents quality closes nevertheless, product quality is not guaranteed. The enterprise production is not big, but enterprise quantity many, has great effect on the corn thresher market. Four is part of the old enterprises and backbone enterprises due to market, capital and product adjustment, or the threshing machine as the accessory products, or production at BanTingChan state, causing the waste of resources and talent. Look from the general characteristics of the product, because the corn thresher is a seasonal product, influenced by geography, and climate conditions, the average pany is according to the agronomic requirements of local and traditional sales for a single varieties of production. On the market at present basically has the following two models: 1, the short form Short form model at present market share is larger, and appeared a batch of production conditions and process level is quite good enterprise. Such as qiu county in hebei province 黑龍江八一農(nóng)墾大學(xué)畢業(yè)設(shè)計 31 machinery plant annual output has reached 30000 units, formed a professional production technology, to a famous brand. And on the basis of short form models, some enterprises have opened a tractor as power, in the fields for workplaces, mobile and flexible, convenient field of new models, adapted to the midlevels, hilly region thresher development needs. 2, duplex, half duplex and feeding machine This kind of machine while the market share is not big, but its quality is relatively good. Its production enterprise mostly pay attention to adjust product structure, strengthen quality management, some products into the international market. The corn thresher product quality in China is not optimistic since 1992, the state bureau of technical supervision of corn thresher held several spot check the quality of the products, from the general trend of development, product sampling percent of pass to increase year by year, from 1992 to 1992 sampling qualified rate is respectively 50%, %, %, %, % and %. But on the whole, the quality of corn thresher is not optimistic, sampling percent of pass at low levels, national field on mechanical and mechanism of small tools, inspection, director of the center for WeiKeQin pointed out that the main problems of corn thresher product has two aspects: one more corn thresher, product unsafe hidden danger is high speed rotating machinery, the transmission part is located in the body of the lateral, working condition is very bad, so the product in the corn thresher safety protection device, feeding device, safety warning device, safety instructions Safety requirements of the 黑龍江八一農(nóng)墾大學(xué)畢業(yè)設(shè)計 32 book, as well as the strength of the bolt used in threshing cylinder parts such as safety and quality, in strong and have clear requirements in the relevant standards. From corn thresher safe in the second quarter of this year the situation of the national quality supervision and spot checks and market research, the serious security hidden danger. Many enterprises factory main table is: the one is not equipped with protective device, some enterprises to cope with examination, only a few wears protective device prototype, but much to market without protective devices. The second is the risk of a significant number of enterprise products parts without warning marks or warning marks is not standard。 黑龍江八一農(nóng)墾大學(xué)畢業(yè)設(shè)計 29 附錄 The corn thresher is one of the most important agricultural machinery in China39。這不僅鞏固了我大學(xué)所學(xué)到的專業(yè)知識 ，而且學(xué)到了許多新的知識。6072. [18] 張文海 .對風(fēng)機風(fēng)量計算公式的認(rèn)識 [J].微電機 ,2021(10). [19] 陶棟材 .現(xiàn)代設(shè)計方法 [M].中國石化 出版社， 20210,1(1):284290. [20] 王延福 .低破損玉米脫粒機的設(shè)計和 分析 [C].甘肅農(nóng)業(yè)大學(xué) ,2021,6:35. 黑龍江八一農(nóng)墾大學(xué)畢業(yè)設(shè)計 28 致 謝 在 王宏立的悉心指導(dǎo)和熱情關(guān)懷下，我經(jīng)過一個月 的學(xué)習(xí)與探索，終于完成了本次的 小型玉米脫粒機的設(shè)計任務(wù)。360380. [11] 孫訓(xùn)方 .材料力學(xué) [M]. 高等教育出版社 ,2021,1(4):7398. [12] 鄧星鐘 .機電傳動控制 [M].華中科技大學(xué)出版社， 2021,3(5):5568. [13] Gao J S， Chase K W， Magleby S P. Generalized 3D tolerance analysis ofmechanical assemblies with small kinematic adjustments. llE Transactions． :367377. [14] 張租立 .機械設(shè)計基礎(chǔ) [M].高等教育出版社 ， 2021,6(2):4652。568. [10] 濮良貴 .紀(jì)名剛機械設(shè)計 [M].高等教育出版社 ,2021,5(8):1015。此外，這次設(shè)計培養(yǎng)了我正確的設(shè)計思想，嚴(yán)謹(jǐn)?shù)目茖W(xué)態(tài)度和獨立工作的能力，查閱和利用專業(yè)資料的能力，綜合分析 解決問題的能力等等 。 進行機械 設(shè)計是一項艱苦的，但 是 頗有收獲的學(xué) 習(xí)過程。能大大減輕農(nóng)民勞動強度，有利于農(nóng)民搶趕農(nóng)時季節(jié)，促進農(nóng)民發(fā)家致富，推動農(nóng)業(yè)的大發(fā)展。與同類產(chǎn)品比，結(jié)構(gòu)非常緊湊，性能良好，操作簡單，安全可靠，不占用場地，搬運存放非常方便。脫下的子粒大部分通過凹板孔，由子?；寤鰴C外。適合北方平原 , 也適應(yīng)南方丘陵地帶 ,具有廣闊市場前景。可用于農(nóng)村家庭式、小型企業(yè)定量生產(chǎn)，也可適用于中型企業(yè)的批量生產(chǎn)，擺脫了傳統(tǒng)手搓和整體打碎方式對玉米進行脫粒，減小了勞動強度，提高勞動生產(chǎn)效率，并降低了破損率，既適合普通玉米脫粒、也適合玉米種子脫粒。操作十分簡單，無需專門的培訓(xùn)，就能很好的操作。 黑龍江八一農(nóng)墾大學(xué)畢業(yè)設(shè)計 26 5 總結(jié)與展望 與同類脫粒機器相比，本機械采用新的脫粒原理 ??20 避免了以前使用直接打擊式脫粒方法對玉米種子的損傷，具有生產(chǎn)效率高、脫粒干凈、并保證了玉米芯的完整。修復(fù)后的脫粒機必須經(jīng)過平衡試驗，正常后方可使用。機架斷裂、機罩變形殘缺 等一定要焊補牢固。 軸承缺油，轉(zhuǎn)動不靈活或有明顯的軸向竄動、徑向晃動，必須認(rèn)真保養(yǎng)和修復(fù)正常后才能使用。作業(yè)中應(yīng)裝上防火帽，并隨時清除積炭。 玉米脫粒機的維修保養(yǎng) 一 般 工作 5— 6h 后應(yīng)停機休息一下，并對脫粒機動力進行檢查。 6．工作時，操作手應(yīng)站在喂人口正前方，喂入量要均勻，當(dāng)喂人量過大或秸稈過濕時，不要強行推送。 4．脫粒機防護罩安裝要牢固，破損的應(yīng)及時修理，其鐵皮厚度不應(yīng)小于黑龍江八一農(nóng)墾大學(xué)畢業(yè)設(shè)計 25 1． 2 毫米，傳動皮帶要設(shè)立防護罩或擋板，以防皮帶飛出傷人。 2．對各轉(zhuǎn)動部件要加油保養(yǎng)，各部緊固螺釘要牢靠，滾筒旋轉(zhuǎn)方向應(yīng)和上蓋所標(biāo)箭頭方向一致。 計算風(fēng)機風(fēng)力 的 最大值，取其與 F 方向一致，假設(shè)玉米 顆 粒的最大截面積為 1 2cm ，玉米粒的重量 大約 為 1g，則作用在單顆玉米上 的 力 F的臨界值為 F=1 211010 3 ??? ? =5 310?? N 則臨界值的風(fēng)壓 Wp=F/S=而由前面的簡化公式 16002 ??VWP 解得臨界速度 V≈ 黑龍江八一農(nóng)墾大學(xué)畢業(yè)設(shè)計 24 玉米粒受力分析 Table8 Force analysis of kernels