台式核桃夹、基于solidworks核桃去壳器设计与三维建模设计【含CAD图纸、说明书】
压缩包内含有 CAD 图纸和说明书,咨询 Q 197216396 或 11970985 摘 要 随着中国经济的发展,人民的生活水平不断提高。以前是希望吃饱,然后是希 望吃好,现在的希望是吃精,不是希望补脂肪而是希望补脑。药物补脑不仅有副作 用而且效果不明显。在这样的情况下,核桃以及其他及坚果类食物就特别受到现代 人的喜爱。但核桃和其他坚果的外壳太过坚硬,即使夹碎了也容易把里面的仁弄坏。 在这样的情况下剥核桃的工具就应用而生,纵观市面上的所有工具,台式核桃夹深 受广大客户的喜欢。 我设计的题目是基于 solidworks 的核桃去壳器设计与实体建模。在本次设计中 我将对核桃破壳计算分析,改进台式核桃夹的构成并对其进行实体建模。 关键词:台式核桃夹;实体建模;核桃破壳计算分析; ABSTRACT With the development of Chinas economy, the improvement of peoples living standard. Before is hope full, then wish to eat, the hope is to eat. Not hope make fat but hope that the brain. Drug brain not only side effects and the effect is not obvious. In this case, walnuts and other nuts and is especially popular with the modern people. But the walnuts and other nuts shell too hard, timely break is also easy to break inside the kernel. In a case like peel walnut tools and applications of health, in the market all the desktop tools, walnut clamp by the majority of customers love. I design topic is based on the SolidWorks walnut sheller design and motion simulation. In this design I will for breaking walnut shell analysis, improved desktop walnut folder structure and its simulation. Keywords: Table Walnut clamp; motion simulation; breaking walnut shell analysis; 压缩包内含有 CAD 图纸和说明书,咨询 Q 197216396 或 11970985 目 录 1 绪 论 .1 1.1 SOLIDWORKS 的发展和荣誉 1 1.2 本论文的背景和意义 3 1.3 核桃夹的简介 3 2 设计内容与方案 .5 2.1 核桃夹的受力分析 5 2.1.1 确定夹核桃所需力 5 2.1.2 建立机构模型,确定主要杆件尺寸 8 2.2 校核杆 1 和杆 2 的强度 .9 2.2.1 杆 1 强度校核 9 2.2.2 杆 2 强度校核 10 2.3 设计创新 11 3 简述零件设计过程 .13 4 台式核桃夹各部件的选材 .23 结 论 .25 参考文献 26 致 谢 .27 压缩包内含有 CAD 图纸和说明书,咨询 Q 197216396 或 11970985 压缩包内含有 CAD 图纸和说明书,咨询 Q 197216396 或 11970985 毕业设计(论文)任务书学生姓名学号班 级指导教师职称单 位 毕业设计(论文)题目基于solidworks核桃去壳器设计与三维建模毕业设计(论文)主要内容和要求:设计一个核桃去壳器。设计时应满足如下基本要求:1) 设计结构合理,简便可靠。2) 对核桃去壳器的零件用solidworks进行三维实体建模。毕业设计(论文)主要参考资料:Solidworks实体设计教程Solidworks实体建模与分析机械设计机械原理毕业设计(论文)应完成的主要工作:1)对核桃去壳器结构进行调查分析,确定设计方案。2)对核桃去壳器的零件用solidworks进行三维实体建模。 毕业设计开题报告学生姓名学号专业班级指导教师职称单 位 课题性质设计 论文课题来源科研 教学 生产 其它毕业设计题目基于solidworks的核桃去壳器设计与三维建模一选题的目的与意义核桃,原产于近东地区,又称胡桃、羌桃,与扁桃、腰果、榛子并称为世界著名的“四大干果”。既可以生食、炒食,也可以榨油、配制糕点、糖果等,不仅味美,而且价值营养很高,被誉为“万岁子”、“长寿果”,据测定,每100克核桃中,含脂肪5064克,核桃中的脂肪71%为亚油酸,12%为亚麻酸,蛋白质为1520克,蛋白质亦为优质蛋白,核桃中脂肪和蛋白是大脑最好的营养物质。糖类为10克,以及含有钙,磷,铁,胡萝卜素,核黄素,维生素,胡桃叶酸,磷脂等营养物。正因为其营养价值极高,所以是现代生活必不可少的食物。但其外壳坚硬无比,想吃到里面的果肉,真是难上加难。这个也是困扰很到想吃核桃但有不想费事的人。超市有买包装好的核桃仁,但经过加工后营养价值必定有所损失。所以用来拨核桃的工具就这样诞生。台式核桃夹,是我的设计与研究课题,其轻便快捷,价格实惠,操作简单,深受广大喜食核桃的消费者所喜欢。虽然结构简单,但社会需求很大。所以对台式核桃夹的研究,设计,与改进有这重大意。二研究现状及发展方向目前市场上拨核桃的工具分为两类,一类为手钳式,如下图所示,这中核桃夹的工图一 手钳式核桃夹作原理是利用杠杆原理,在一个固定的位置上,手钳的两个钳柄相对或者相向运动,用这个力压碎核桃,这种核桃夹的优点是结构简单,价格便宜,便于携带。缺点也有,就是适合有力气的人来用,老人小孩不适合用,因为需要很大力气。有的时候力气太大核桃会碎,容易滑落,并且距离不好调整,每次核桃的大小不一,不经常用的人距离把握不准,所以使用起来特别不方便,适合经常用的人使用,不然想看到完整的核桃仁是难。另一种拨核桃的工具是台式核桃夹,也是我的设计与研究课题,如下图:图二 台式核桃夹三维实体图从图上可以看出,台式核桃夹相对于手钳式的比较复杂,台式核桃夹的工作原理是在利用杠杆原理的基础上在利用连杆机构,手柄越长就越容易压碎核桃。并且右边的螺杆可以调节距离,当核桃大时候,或者者小的时候都可以调节到一定的距离然后手柄压到底也不会压碎核桃。另外台式核桃机的好处是其他一些坚果都可以用台式核桃机拨壳。另外老人和小孩都可以轻松的用。三研究内容及方案本课题,我的主要任务是用Solidworks2010对台式核桃机经行仿真和设计改进,具体设计方案是省力,所以用杠杆和连杆机构。另外,因为核桃机属于食品机械,所以对材料的选择也是至关重要的。如下图,台式核桃机有如下几个零件组成。1. 底板2. 手柄组件3. 活动杆4. 调整螺杆5. 连接架和连接杆这个几个零件的选材一般会选择健康无毒的材料。底座木质板,余为铸铁喷漆或电镀件,木质手柄。可夹坚果类最大为45mm。其中在活动杆和调整螺杆的两个端面上加工的时候留有凸台,如下图: 这个凸台的作用是在压核桃的时候,防止核桃旋转,另外有这个凸台,核桃壳容易破碎,桃仁不容易碎掉。台式核桃机的核心部分,也是区别台式核桃机和手钳式核桃夹的主要区别地方,如下图,这个是利用了杠杆和连杆机构,下压手柄的时候,连接架会利用连杆的原理左右移动,成一定角度。但活动杆水平左右移动,这样的好处是使核桃受力均匀。有时候核桃大小不一样,有时候夹的不一定是核桃,有可能是其他一些比核桃小的坚果,这个时候就要需要有调整机构,不然不是压不到核桃就是容易把核桃压碎。这个机构如下图所示:将螺杆向前调整时可以拨掉一些比核桃小的坚果,将螺杆向后调节,可以拨一些比核桃大一点的坚果。差不多大小的坚果,调节到一定距离后,手柄压到底也不会压碎果仁。五、进度安排序号毕业设计各阶段内容时间安排备注1市场调研,查阅资料,完成开题报告;2010.12.102010.12.202结合课题进行外文资料阅读,完成英文翻译; 2010.12.212010.12.313学习相关的知识、熟悉有关的资料,完成文献综述;2011.1.12011.1.204构思台式核桃夹具体结构2011.1.212011.2.15对核桃夹进行三维模拟和优化2011.2.22011.3.206对台式核桃夹进行实体建模2011.3.212011.4.207整理资料,编写设计说明书;准备答辩。 2011.4.212011.5.5六、预期结果通过对市场上现有核桃夹的调研与改进,通过Solidworks2010对台式核桃夹的设计与仿真,是我对这个软件有了更深的了解与应用。并且对台式核桃夹的结构有个更深的了解和构思。七、参考文献1 徐憬.机械设计手册.机械工业出版社,2000.62 张普礼.机械加工工艺装备.东南大学出版社,2002.33 刘思.食品机械的开发与研究 2000.74 正亚军 食品材料的应用于研究2001.35 周长城,Solidworks2010高级应用于研究 ,1997.7 指导教师意见:指导教师签名:年 月 日教研室意见:审查结果: 同 意 不 同 意教研室主任签名:年 月 日 本科毕业设计外文资料翻译系 别:专 业:姓 名:学 号: 外文资料翻译译文Microwave in walnut shell materials tensile mechanical properties of impact studyAbstractTaking the picking fresh walnuts as the research object, the microwave walnut break hull test, break hull rate of 87.65%; And of microwave effects on the walnut shell materials tensile mechanical properties of influence, and the results showed that the microwave processing, walnut shell material elastic modulus, tensile strength and mechanical indexes and processing there were no significant changes before. In addition, also in walnut shell tensile mechanical properties of the tested and won the walnut the tensile strength of the place relict limit to 1. 47 M Pa, for sure walnut emerged inflationary pressure in microwave needed to provide the reference.Keywords: microwave; Break hull; The whole shell tensile; Mechanical properties0 PrefaceWalnut machinery of the existence of high rate of broken emerged, the kernel rate is low has been restricted walnut realize mechanization production and processing of the important reason of our country, the development of walnut industrial caused certain influence. Therefore, explore new methods for realizing mechanization walnut emerged industrialization and export income, increase the economic benefit has urgent practical significance. At present, the technology for walnut mechanization emerged research focus on the gap emerged, blow for extrusion emerged, methods and the application of finite element method for related mechanical design emerged, but still has broken rate is high, the whole kernel rate low. In addition, the emerging technology used in the research is also emerged nuts is in the ascendant, such as YangRui etc in walnut laser irradiation behavior by the numerical analysis and simulation, explores the laser technology shelling mechanism; LiXiaoXia explores the buckwheat shell microwave method; ZhangLi, Yang fu Ephraim with microwave technology, realize the board of chestnut shell.The author on the basis of previous studies, of microwave technology function mechanism of walnut emerged proposes that emerged walnut microwave method is feasible. This paper is to study this paper further discusses the front, to search for microwave processing technology parameters (power, time, humidity and temperature) in walnut shell material mechanics and the influence law of nature, studied the microwave technology role walnut shell material stretching before and after the mechanical properties of differences, and determine the seam walnut the tensile strength of the limit in, to determine the walnut microwave emerged inflationary pressure and further guidance for microwave technology parameters are selected to provide the reference.1 Walnut microwave break hull testWalnut is primarily through microwave microwave break hull role in walnutmeat, its internal water molecules in alternating under the influence of electromagnetic field polarization orientation for high frequency shift, the internal walnut in short time produce very high quantity of heat form high pressure water vapor, when water vapor pressure of the pressure of walnut is inflation pressure is greater than the ultimate tensile stress walnut, walnut burst. Therefore, the density of the nut shell is its internal structure formed an important guarantee of high pressure; The walnuts contain moisture is internally generated the material basis of high pressure water vapor; Microwave technology parameters (power, time and temperature, etc) is able to rupture external power of walnut. Therefore, it is necessary to walnut microwave technology needed to break hull parameters were tested.1.1 materials and equipmentTest is just picked off cortical JinLong 1 cotton walnut as the research object, the walnuts moisture content of 21%, to prevent water loss, will test sample in a plastic bag sealed stored in the refrigerator for refrigeration.W LD 07S-08 type glanze microwave ovens, microwave role, power and temperature are time adjustable; Vernier gauges.1.2 test methodThe three factors 3 level completely combination test, each portfolio selection three shape, size close of walnut similar as repeated samples. Before the test test walnut trunnion, diameter, caliper size. The end, observation and rupture of walnut recorded.1.3results and analysisWalnut microwave break hull situation as is shown in table 1. Table 1 walnut microwave break hull test results Group numberTemperaturePowerWTimeminBroken shell /%1503002100250300366.7350300433.345050021005505003100650500466.77507002100850700366.795070041001060300266.71160300366.71260300410013605002100146050031001560500410016607002100176070031001860700466.71970300266.72070300310021703004100227050021002370500366.724705004100257070021002670700310027707004100From the table that 1, 81 a walnut, only 10 star have not broken open, break hull rate reached 87. 65%, if consider alone each temperature, each power, each time break hull rate, the result in table 2.Table 2 single factor in walnut the influence of emerged rateFactorTemperature/Power/wTime/min50670300500700234Broken shell /%81.588.892.674.192.696.385.285.292.6From the table 2, it is known that in the three factors, the temperature of high and low vapor pressure of the internal to the size of the size of the power to the internal temperature rise the speed of the water vapor; Because W LD 07S-08 type microwave equipment work characteristics, that is, to stop working after set temperature, so the length of time can not influence within the maximum pressure steam shell, will not affect the speed of temperature rise. So time to the influence of the factors emerged relatively small rate, and the results were consistent with the findings.2 Microwave in walnut shell materials tensile mechanical properties of influenceThrough to the walnut microwave before and after processing the contrast test that destructive compression, microwave treatment of walnut compression significantly less destructive power, this shows that on lots of walnut break hull, for in the microwave treatment not burst of walnut and compression is the easy emerged. In addition, we also found that the microwave process, walnut high pressure water vapor by the inside of the role, the tensile deformation happen. Therefore, the microwave technology in walnut shell materials tensile mechanical properties of influence, but for further reveal the mechanism of the walnut microwave emerged provides the basis. The author of such microwave before and after the shell material role elastic modulus and tensile strength comparison test.2. 1 sample preparationThe test samples and in front of the experimental study of walnut emerged the same, with the saw in walnut along the axis direction for about 10 mm long, wide about 2 mm of walnut as specimens. Because walnut is curved shell form, had taken the length of the specimen should be as low as possible, in the direction of the small curvature of the better effect under saws. Will pass the microwave processing and without processing (control group) were made of walnut specimens, with caliper measured the length, width and thickness.2. 2 equipment and methodsSAN S CMT 6140 microcomputer control electronic universal testing; Accuracy of 5% N 200 N sensor.Set for 10 mm loading rate/m in, the routine material mechanics tensile test methods. Because of the specimen is too small, to avoid gripping broke when specimens or clip slanting, gripping use tweezers when operating. Record force deformation and fracture walnut of force value.2. 3 results and analysisWalnut shell materials tensile mechanical indexes such as test value shown in table 3.From the table 3, it is known that the microwave processing get after the modulus of elasticity as walnut 21. 82 M P a, tensile strength of 10. 043 M Pa; Before the microwave processing elastic modulus is 22. 52 M Pa, tensile strength for 9. 57 MP a. microwave effects on the walnut shell that material has a little influence on tensile mechanical properties.LiangLi etc: microwave in walnut shell materials tensile mechanical properties of impact studyTable 3 walnut shell materials tensile mechanical property indexNumberLength /mmWidth /mmThickness /mmArea /mm2Most strongly /NModulus of elasticity /MpaTensile strength /Mpa113. 601.901.382.6220.3424.207.76Control14. 262.561.704.3540.424.009.29210.682.001.482.9629.5427.709.98Control11.522.561.784.5625.5526.705.61310.242.621.082.8310.3820.403.67Control14.961.801.703.0610.767.033.52416.303.581.987.0977.263.5910.90Control15.182.881.985.781.0312.4014.21513.223.681.164.2772.7420.0017.60Control14.823.202.006.438.6317.2012.84616.663.921.485.891.2612.4012.87Control17.643.981.485.89106.3132.8018.05714.262.981.283.8156.1746.0014.72Control13.843.322.147.184.7018.3011.92814.962.001.783.5662.5611.9017.57Control11.823.921.827.1345.9932.206.45915.122.701.283.469.2529.702.68Control10.783.001.725.1656.5917.1010.971014.562.441.884.5912.3022.302.68Control12.383.021.484.4712.8357.502.883 Walnut shell whole stretch mechanics performance is determinedEmerged from walnut microwave experimental results that, by all the breakdown of the sample after microwave processing are from walnut suture line the breakdown of the place, and it shows in walnut suture line tensile mechanical properties and surface of different materials walnut. Therefore, the need to place relict tensile mechanical nature of the study, this needs in walnut shell the tensile test. Because of walnut size is differ, irregular shape, test the clip if too loose, the tensile easily when slippage; If the clip too tight, it is easy to appear clip crack a phenomenon, so difficult test. For this reason, we designed a set of adjustable size shape walnut shell chuck for walnut shell of the tensile test.3. 1 equipment and methodsTest in SAN S CMT 6140 microcomputer control electronic universal testing machine, a self-made walnut special jig. Before the test, will walnut and surface with a fixture acetone clean, and the determination of walnut trunnion, side diameter and diameter. The two clamping fixture first in the testing machine, adjust the fixture chuck size to appropriate value will chuck after fixed, again with strength and AB glue stick to the fixture will walnut (will show the seams of the walnut, do not stick on the glue) to try to ensure that the center of the two fixtures in one line, and walnut and the vertical seam lines. To glue dry after appearing again the walnut shell stretch mechanics performance test, the end of the shape of the cross section will walnut surveying and mapping out and record the most strong values.3. 2 results and analysisIn walnut shell when the tensile, walnut seam place along the cracked. At this time, the stress in walnut suture line reaches limit, this stress value is measured by the testing machine of the most strongly and shifted walnut in circular seam for the calculation of the sectional area. Test results listed in table 4.Table 4 walnut shell tensile test the test resultsSerial numberShaft Diameter /mmDiameter /mmSide diameter /mmShell thickness of suture /mmDensity of the suture line /( Nmm- 1)Most strongly /NUltimate tensile strength of suture /MPa130.7030.4630.985.167.17685.701.44230.0031.3038.201.982.85279.641.40335.8238.0039.506.248.27985.991.64438.5832.3630.764.506.27636.771.45533.0034.8033.204.594.28467.731.11633.8234.0234.142.263.80406.261.81The mean33.6733.4934.464.105.44577.021.47From the table 4, it is known that the seam of walnut in limit tensile stress for 1. 47 MPa, and walnut on the surface tensile stress value 9. 57 MPa compared are much smaller, this is what walnut in microwave role in the cause of the broken seam after, this limit tensile stress can be used as microwave technology parameter selection basis.4 ConclusionBased on the test of fresh walnuts emerged, and walnut shell material and the mechanical properties of walnut shell are tested, get the following main conclusions:(1) the fresh walnuts microwave process after the break hull rate can amount to 87. 65%, in the microwave technology parameters, temperature and power is the time factor to influence emerged rate.(2) test after the microwave processing of walnut elastic modulus is 21. 82 MPa, tensile strength of 10. 043 M Pa, both with the processing there were no significant changes before that microwave role in walnut shell material has a little influence on tensile mechanical properties.(3) test in the seam of walnut limit tensile stress value is 1. 41 MPa, and walnut shell material limit tensile stress value is much more than a small, for choosing suitable for microwave technology parameters of walnut emerged provides reference basis.References:1 ShiJianXin, Michael essien moving army. Walnut kernel machinery at home and abroad and emerged from the present situation and the problem study J. J xinjiang agricultural mechanization, 2001 (6) : 29 32.2 Michael essien moving army. Walnut kernel methods and test emerged take D. Urumqi: xinjiang agricultural university, 2002.3DongYuan DE, ShiJianXin, QiaoYuanYuan. Walnut different way of emerged emerged take effect benevolence J. Journal of agricultural products processing, 2007 (9) : 4 5, 9.4 ShiJianXin, ZhaoHaiJun, Michael essien moving army. Based on the finite element analysis technology of walnut shell J. Journal of agricultural engineering, 2005, 21 (1) : 185 188.5 WuZiYue. Cotton walnut shell take benevolence of mechanical J. Journal of agricultural engineering, 1995, 11 (4) : 164 169.6 YangRui, yan. Laser and walnut interaction is the mechanics and finite element analysis J. Agriculture machine research, 2008 (4) :.7 LiXiaoXia. Buckwheat shell mechanical properties and microwave process test emerged D. TaiGu: shanxi agricultural university, 2008.8 ZhangLi. Chestnut microwave device mechanism and processing technology research D. Hefei: hefei university of technology, 2004.9 Yang fu Ephraim, takami m, ZhuNiu. Use the microwave can related to the new technology of garments shell to new method J. Food science and technology, 2006 (9) : 80 83.外文原文微波对核桃壳体材料拉伸力学性质的影响研究摘 要以刚采摘的新鲜核桃为研究对象,进行了微波核桃破壳试验,破壳率达到87.5%,同时,研究了微波作用对核桃壳体材料拉伸力学性质的影响,结果表明:微波处理后,核桃壳体材料弹性模量、抗拉强度等力学性质指标与处理前比较无明显变化。另外,还对核桃整壳拉伸力学性质指标与处理前比较无明显变化。另外,还对核桃整壳拉伸力学性质进行了测定获得了核桃壳缝合线处的拉伸强度极限值为1.47MPa,为确定核桃微波破壳所需的膨胀压力提供了参考依据。关键词:微波;破壳;整壳拉伸;力学性质0 前 言核桃机械破壳存在的破碎率高、整仁率低等问题一直是制约核桃实现机械化生产加工的重要原因, 对我国核桃产业的发展造成了一定影响。因此,探索新的机械化核桃破壳方法对于实现产业化、出口创汇、增加经济效益等具有迫切的现实意义。目前,国内外对于核桃机械化破壳技术的研究主要集中在定间隙挤压破壳、打击破壳等方法及应用有限元等方法进行相关破壳机械的设计方面,但仍存在破碎率高、整仁率低等问题。另外,将新兴技术应用于坚果破壳的研究也是方兴未艾,如杨锐等对核桃受激光辐照行为进行了数值分析与模拟,探索了激光技术脱壳机理;李晓霞探索了荞麦微波脱壳方法; 张莉、杨芙莲等利用微波技术实现了对板栗的脱壳。作者在前人研究的基础上,对微波技术进行核桃破壳的作用机理进行了初探,证明核桃微波破壳方法是可行的。本文是对前面研究的进一步深入探讨,为探求微波加工工艺参数(功率、时间、湿度和温度)对核桃及壳体材料力学性质的影响规律,试验研究了微波技术作用前后核桃壳体材料拉伸力学性质的差异,并测定了核桃壳缝合线处的拉伸强度极限值,为确定核桃微波破壳所需的膨胀压力并为进一步指导微波技术参数的选择提供参考依据。1 核桃微波破壳试验核桃微波破壳主要是通过微波作用于核桃仁时,其内部水分子在交变电磁场作用下极化取向作高频转变,致使核桃壳内部在短时间内产生很高的热量形成高压水汽,当高压水汽对核桃壳的压力即膨胀压力大于核桃壳的拉伸极限应力时,核桃壳发生破裂。因此,果壳的致密结构是其内部形成高压的重要保证;核桃仁所含的水分是内部产生高压水汽的物质基础;微波的技术参数(功率、时间和温度等)则是核桃壳能够破裂的外在动力。因此,有必要对核桃微波破壳所需的技术参数进行试验研究。1.1 材料与仪器试验选用采摘后刚褪去外皮的晋龙1号棉核桃为研究对象,核桃仁含水率达 21% , 为防止水分散失,将试验样本用塑料袋密封置于冰箱内藏,WLD07S-08 型格兰仕微波炉,微波作用温度、功率和时间均可调;游标卡尺。1.2 试验方法采用3因素3水平完全组合试验,每个组合选取3个形状相似、大小相近的核桃作为重复样本,试验前测试核桃的轴径、横径、测径大小。试验结束时,观测核桃壳破裂情况并进行记录。1.3 结果与分析核桃微波破壳情况如表 1所示。表 1 核桃微波破壳试验结果组号温度/功率w时间min破壳率 /%1503002100250300366.7350300433.345050021005505003100650500466.77507002100850700366.795070041001060300266.71160300366.71260300410013605002100146050031001560500410016607002100176070031001860700466.71970300266.72070300310021703004100227050021002370500366.724705004100257070021002670700310027707004100由表 1可知,81颗核桃中只有10颗未破开,破壳率达到 87. 65% ,若单独考虑每个温度、每个功率、每个时间的破壳率,其结果见表 2。表 2 单因素对核桃破壳率的影响因素温度/功率/w时间/min50670300500700234破壳率/%81.588.892.674.192.696.385.285.292.6由表 2可知, 在这 3个因素中,温度的高低决定壳体内的水蒸汽压力的大小;功率的大小决定壳体内水蒸汽温度上升的快慢;由于WLD07S-08型微波设备的工作特点,即达到设定温度后就停止工作,故时间的长短不能影响壳体内水蒸汽的最大压力,也不影响温度上升的快慢,所以时间因素对破壳率的08型微波设备的工作特点,即达到设定温度后就停止影响相对较小,与前期研究结果一致。2 微波对核桃壳体材料拉伸力学性质的影响通过对核桃微波处理前后压缩破坏力的对比试验得知,微波处理后核桃的压缩破坏力明显减少,这说明在进行大量核桃破壳时,对于在微波处理后未发生破裂的核桃再进行压缩破壳是比较容易的。另外,我们还发现微波作用过程中,核桃壳受到内部高压水汽的作用,发生了拉伸变形。因此,研究微波技术对核桃壳体材料拉伸力学性质的影响, 可为进一步揭示核桃微波破壳的作用机理提供依据。作者对微波作用前后壳体材料的弹性模量及抗拉强度进行了对比试验研究。试验所用样本与前面核桃破壳试验研究中相同,用锯条在核桃上沿轴线方向获取长约10mm,宽约 2 mm的核桃壳作为试件。因为核桃是曲壳形的,所取试件的长度应尽量小,在曲率越小的方位锯下的效果越好。将经过微波处理和未经处理(对照组)的核桃均制成试件,用游标卡尺测取其长度、宽度和厚度。2.2 设备及方法SANS-CMT 6140微机控制电子万能试验,精度达5%N的200N传感器。设定加载速率为10mm/min,采用常规材料力学拉伸试验方法进行。由于试件太小,为避免夹持时弄断试件或夹歪,夹持时使用镊子操作。记录力变形曲线以及核桃壳发生破裂时的力值。2.3 结果与分析由表3可知,得到微波处理后核桃壳的弹性模量为21.82M P a,抗拉强度为10. 043 MPa;微波处理前弹性模量为22. 52MPa,抗拉强度为9.57MPa。说明微波作用对核桃壳体材料的拉伸力学性质影响不大。表 3 核桃壳体材料拉伸力学性质指标值编号长度 /mm宽度/mm厚度 /mm面积 /mm2最大力 /N弹性模量 /Mpa抗拉强度/Mpa113. 601.901.382.6220.3424.207.76对照14. 262.561.704.3540.424.009.29210.682.001.482.9629.5427.709.98对照11.522.561.784.5625.5526.705.61310.242.621.082.8310.3820.403.67对照14.961.801.703.0610.767.033.52416.303.581.987.0977.263.5910.90对照15.182.881.985.781.0312.4014.21513.223.681.164.2772.7420.0017.60对照14.823.202.006.438.6317.2012.84616.663.921.485.891.2612.4012.87对照17.643.981.485.89106.3132.8018.05714.262.981.283.8156.1746.0014.72对照13.843.322.147.184.7018.3011.92814.962.001.783.5662.5611.9017.57对照11.823.921.827.1345.9932.206.45915.122.701.283.469.2529.702.68对照10.783.001.725.1656.5917.1010.971014.562.441.884.5912.3022.302.68对照12.383.021.484.4712.8357.502.883核桃整壳拉伸力学性能的测定从核桃微波破壳试验结果看出,所有经微波处理后破裂的试样均是从核桃缝合线处破裂的,这说明核桃缝合线处的拉伸力学性质与核桃壳表面材料的有所不同。因此,需要对缝合线处的拉伸力学性质进行研究,这就需要对核桃整壳进行拉伸试验。由于核桃大小不一,形状不规则,试验时若将其夹得太松,则拉伸时容易滑脱;若夹得太紧,则易出现夹裂现象,所以试验难度较大。为此,我们专门设计了一套可调节尺寸的壳形核桃夹头来进行核桃整壳的拉伸试验研究。3.1 设备与方法试验在 SANSCMT6140微机控制电子万能试验机上进行,采用自制的核桃专用夹具。 试验前,将核桃和夹具表面用丙酮清洗干净,并测定核桃的轴径、侧径和横径,将两个夹具先装夹在试验机上,调节夹具夹头尺寸至合适值后将夹头固定,再用强力AB胶将核桃粘到夹具上(将核桃的接缝露出,不可粘上胶),尽量保证两个夹具的中心在一条线上,且使核桃的缝合线与该中心线垂直。待胶完全干透后再进行核桃整壳拉伸力学性能测试,试验结束时将核桃断面的形状测绘出来并记录最大力值。3.2 结果与分析在进行核桃整壳拉伸时,核桃沿缝合线处裂开。此时,核桃缝合线处的应力达到极限值,该应力值是通过试验机上测出的最大力与裂开后核桃缝合线处的环形截面积计算得到的,测试结果列于表4。表4 核桃整壳拉伸试验测试结果序号轴径 /mm横径/mm侧径 /mm缝合线处壳厚/mm缝合线密度/( Nmm-1)最大力 /N缝合线处极限拉伸应力/MPa130.7030.4630.985.167.17685.701.44230.0031.3038.201.982.85279.641.40335.8238.0039.506.248.27985.991.64438.5832.3630.764.506.27636.771.45533.0034.8033.204.594.28467.731.11633.8234.0234.142.263.80406.2
收藏