【正文】 、大型容器、油缸、重型機(jī)械設(shè)備、礦山機(jī)械、電站、廠房結(jié)構(gòu)、40?以下的低溫壓力容器，橋梁等結(jié)構(gòu)件，還可制作滲碳零件注：取自《機(jī)械零件設(shè)計(jì)手冊》第三版，ISBN 75024132432．?dāng)嗝骊P(guān)于z軸的慣性矩計(jì)算 (529)由公式529分別計(jì)算各部分對z軸的慣性矩：IZ1==289977333mm4 IZ2==349093573mm4 IZ4==728370373mm4 IZ=IZ1+IZ2+IZ3+IZ4=109mm4=103m4 3．計(jì)算斷面上的最大拉應(yīng)力和最大壓應(yīng)力由圖59所示，可以確定最大拉應(yīng)力作用點(diǎn)和最大壓應(yīng)力作用點(diǎn)到中性軸的距離分別為： ymax=彎矩計(jì)算公式如下σmax+=Mzymax+Iz(拉) （530）σmax=MzymaxIz(壓) （531）應(yīng)用公式5531，；Iz的單位化為m4；ymax+和ymax的單位化為m，將已知數(shù)值代入公式，得到：σmax+=Mzymax+Iz=103N?m103m4=106Pa=(拉)。σmax=MzymaxIz=103N?m103m4=106Pa=(壓)。4．安全系數(shù)校核查表53和表54可知頂梁許用安全系數(shù)[n]=，20mm厚的16Mn鋼板σs=325MPa計(jì)算頂梁安全系數(shù)為：＞[n]由以上計(jì)算可知頂梁強(qiáng)度滿足使用要求。結(jié)束語采用液壓支架對開采工作面的頂板進(jìn)行支護(hù)是綜合機(jī)械化采煤的一個(gè)必要條件，而綜合機(jī)械化采煤又是煤礦技術(shù)進(jìn)步的標(biāo)志，是煤礦增加產(chǎn)量、提高勞動(dòng)效率、增加經(jīng)濟(jì)效益的重要手段。因此大力發(fā)展綜合機(jī)械化采煤，研制和使用液壓支架是十分關(guān)鍵的。此次以支撐掩護(hù)式液壓支架為題畢業(yè)設(shè)計(jì)是我們走上工作崗位前的最后又一次練兵，為我們能順利進(jìn)入工作狀態(tài)奠定了基礎(chǔ)。我們作為即將畢業(yè)的機(jī)械制造及其自動(dòng)化大學(xué)生，未來生產(chǎn)行業(yè)的技術(shù)人員，設(shè)計(jì)和生產(chǎn)出高技術(shù)含量、高安全系數(shù)的機(jī)械產(chǎn)品是我們的責(zé)任。通過此次對支撐掩護(hù)式液壓支架的設(shè)計(jì)，使我對液壓支架的結(jié)構(gòu)和工作原理及其它相關(guān)理論有了一個(gè)很深刻的認(rèn)識。在這段時(shí)間里，通過對液壓支架的選型設(shè)計(jì)，總體設(shè)計(jì)，受力分析，強(qiáng)度校核等工作，綜合運(yùn)用了大學(xué)期間所學(xué)到的知識并學(xué)到了很多新的知識，使我深刻認(rèn)識到了知識積累的重要性。開始對液壓支架等相關(guān)技術(shù)很不了解的狀態(tài)，也不能有效地把所學(xué)過的只是綜合應(yīng)用，通過查看相關(guān)的資料書籍和老師指導(dǎo)，讓自己頭腦中模糊的概念逐漸清晰，又通過實(shí)習(xí)進(jìn)一步了解了液壓支架，為順利的設(shè)計(jì)奠定基礎(chǔ)。支撐掩護(hù)式液壓支架設(shè)計(jì)即將結(jié)束。幾個(gè)月來，從開始接到論文題目到參數(shù)計(jì)算、作圖，再到論文的完成，每走一步對我來說都是新的嘗試與挑戰(zhàn)，這也是我在大學(xué)期間完成的最大的項(xiàng)目。雖然我的論文不是很成熟，還有很多不足之處，但這里面的每一個(gè)圖、每一個(gè)數(shù)，都有我辛勤汗水的結(jié)晶。使我感覺到了知識充實(shí)帶來的快樂。這次做論文的經(jīng)歷也會使我終身受益，我感受到做研究是要真真正正用心去做的一件事情，是真正的自己學(xué)習(xí)的過程和研究的過程，沒有學(xué)習(xí)就不可能有研究的能力，沒有自己的研究，就不會有所突破。希望這次的經(jīng)歷能讓我在以后學(xué)習(xí)和工作得到更大的進(jìn)步。參考文獻(xiàn)[1]魯忠良,景國勛,：煤炭工業(yè)出版社，[2]：中國礦業(yè)大學(xué)出版社，.[3]李炳文,：中國礦業(yè)大學(xué)出版社，. [4]：化學(xué)工業(yè)出版社，.[5]：中國礦業(yè)大學(xué)出版社，[6]東北大學(xué)《機(jī)械零件設(shè)計(jì)手冊》：冶金工業(yè)出版社，.附錄一（英文）Development of 30Cr06A, a high strength cast steel and its welding abilityAbstract: High performance hydraulic supports have a high requirement in strength, toughen ss and welding ability of socket this problem, we analyzed the properties of the high strength socket material 30Cr06, used in high performance hydraulic supports both at home and abroad and developed a new kind of high strength cast steel 30Cr06A, by making use of an orthogonal experiment, which provided the design conditions for its optimal po sition. The result shows that the strength and toughness of the newly developed high strength cast steel 30Cr06A is much better than that of 30Cr06. Theoretical calculations,mechanical property tests and hardness distribution tests of welded joints were carried out for a study of the welding ability of the new material, which is proved to be very good. Therefore, this 30Cr06A material has been successfully used in the socket of high performance hydraulic support.Key words: Hydraulic support。 socket material。 30Cr06A。 strength。 toughness。 welding ability1 IntroductionWith the improvement of fully mechanized coal mining, the demand for hydraulic support with great working resistance and high reliability keeps order to meet these requirements and to reduce the weight of hydraulic support, the steel used for making hydraulic support demands increasingly higher strength, especially steel, used for sockets which are the major parts to bear maximum weight,requires high prehensive mechanical properties and welding ability. Targeting this problem, we analyzed the socket material 30Cr06 and developed a new type of high strength cast steel order to enhance the strength and toughness of the cast steel, we changed its position by adding two new elements (Mo and Ni) and obtained the optimal chemical position for 30Cr06A using an orthogonal experiment. The test results show that the strength property of the 30Cr06A socket has increased by 20%, its toughness has also been considerably enhanced and its prehend dsive mechanical property is close to the advanced international standard (DBT socket mater ial)[1]. Socket accessories are connected with a bracket base and top girder by welds so that it demands socket material with a high welding ability. A mechanical performance test, a hard ness distribution test and a metallographic structural analysis of the heat affected zone of the welded joint were performed to evaluate the welding process and properties of welded joints of 30Cr06A. The newly developed material and our research achievements have been satisfa ctorily applied in the design of highend hydraulic support.2 Development of 30Cr06A Design of positionBy changing the alloy position of the former socket material 30Cr06A, the yield strength of the new material reached 750 MPa or more, the impact toughness was greater than 50 at a temperature of –20176。C and its welding ability is also high. Table 1 shows the main elements of 30Cr06A. In the process of development,two elements, Mo and Ni were two elements strengthen the solid solubility of ferrite and improve the quenching capability of enhances the impact toughness, especially at low temperatures, while at the same time, improving the machining and welding ability of steel. Mo resists hydrogen and reduces the content of diffusive hydrogen in the process of welding, which improves the welding ability of the new material[2]. The amounts of alloys have different effects on the capability of steel as well as on the structure of the alloy, the heat treatment and the structure after processing. According to these different effects, the amounts of the five elements Si, Mn, Cr, Mo and Ni are mainly controlled by the design. From production experience, the mass fraction of C remains in the range from to [3].The amounts of different elements of the new material are listed in Table 1.Table 1 Composition of 30Cr06A pared with 30Cr06 (%)CompositionC Si Mn Cr Mo Ni30Cr06––––30Cr06A–––––– Orthogonal experimentFrom an orthogonal experiment, the optimal design of the elements was found. We experimented with five state ranges within each element for each of the five elements, expressed in percent by weight, as shown in Table 2. According to the orthogonal table L21(55) of orthogonal designs, only 21 test groups are required to obtain the precise optimal range. According to Table 2 and considering the main elemen