KQYJ-1T 空气压机设计【说明书+CAD+SOLIDWORKS】

KQYJ-1T 空气压机设计【说明书+CAD+SOLIDWORKS】,说明书+CAD+SOLIDWORKS,KQYJ-1T,空气压机设计【说明书+CAD+SOLIDWORKS】,kqyj,气压,设计,说明书,仿单,cad,solidworks 空气压机设计前言 时间转瞬即逝，转眼之间四年的大学生涯就要结束了，回首四年的学习生活，我感到自己的收获无比丰富。四年来，我不仅认真学习了各门基础课，而且更加系统地掌握了多门专业技术课，在每次的课程设计中，我都认真对待，努力钻研。这样，通过四年的锻炼不断地提高了我的设计、绘图、识图能力。可以说，大学里的理论基础，不但使我学会了分析问题、解决问题的能力，而且更强化了我的知识结构。尤其幸运的是，我不只一次地深入工厂实习，把学到的知识应用于实习现场的具体工作中，提高了自己的动手能力，为我今后步入工作岗位打下了更好的实践基础。 本次设计的目的培养学生初步掌握独立从事专业技术工作的能力，提高学生从事工艺和工艺装备设计的水平，使学生初步掌握从事本专业科学研究工作的能力。通过毕业设计不但培养了我们运用各种工具书的方法和技巧，同时也培养了我们独立思考问题、解决问题的能力。通过翻阅查找各种工具书，扩大了视眼，丰富了自己的知识范围。 本次设计我们是有充分准备的。我们不仅准备了四年的时间来掌握各门专业课学习，而且我们多次深入工厂实习，更主要的是设计期间不断地从网上、图书馆收集大量的资料，寻找各种解决问题的方法。所以说本设计我们是有充分准备的，它是与生产实际相结合。它也将成为我们走上工作岗位的一次重要演习，为我们今后的工作打下坚实的基础。 第一章 电控气动压力机方案设计 1.1 设计任务抽象化 设计要求：所设计的设备要求完成自动送料出入至施压点、给予和清刷冲头等功能。并要求每次给定的压力在一定的范围内，保证效率在每分钟620次，工作压力不小于0.6Mpa，能量220V交流电。1.1.1建立黑箱 1.1.2功能分解 1.2确定工艺原理 确定依据：成本、质量、效率三者综合比较。 功 能1. 实现对料粉一定压力压实。2.工作频率没分钟620次。必要要求必要要求加工4.小批生产，中小型厂加工基本要求成本5. 成本不高6.结构简单附加要求附加要求使用 7.操作方便附加要求1.3确定技术过程1.4引进技术系统，确定边界1.5确定功能结构 1.5.1 技术系统总功能，及进行功能分解空气压机（KQYJ-1T）电控气动压力机的动力源为压缩空气，它是通过使用倍力气缸和配重块来完成对壳体内的压料进行压实，由于作用在壳体药剂内的力是一对相互作用力，因此在配重块不变的情况下每次压装时壳体内药剂受到的作用力是一致的。工作过程：将装有需要压装的产品模子放入送模滑板上的模具底座内，按下启动按钮后延时t秒（可调），送模气缸动作将模子送到工作位置，同时模子进出门洞关起，倍力气缸控制阀工作，活塞杆推动托模上移块将到位的模座和模子向上推起，压药冲通过脱模导冲板和导冲模进入产品壳体内压实药剂，在压力增加的过程中，压药冲将作用力传给压头和配重块支架并将起顶起上移，当支架托块上移到脱离接近开关的感应时，倍力气缸进气口停止进气，保压一定时间后倍力气缸反向进气，托模上移块下移回位，送模滑板动作将模座和模子一起送出回到起始位，在将模子从模座中取出前，送模滑板一直保持起始状态，只有当从模座内取出模子并再次放入产品后，下一个工作循环才能进行。当倍力气缸活塞杆回到位后，清刷计数到后，清刷缸开始对冲子清刷，清刷的次数由文本上设置而定，只有当清刷完后，才可以进入下一个产品的。在清刷过程中如有异常可按下急停开关停止清刷。第二章 倍力气缸设计2.1 工作动力类型的选择经查阅资料和市场考察，决定使用气动气缸为工作动力。气动技术有以下优点: (1)介质提取和处理方便。气压传动工作压力较低，工作介质提取容易，而后排入大气，处理方便，一般不需设置回收管道和容器:介质清洁，管道不易堵存在介质变质及补充的问题. (2)阻力损失和泄漏较小，在压缩空气的输送过程中，阻力损失较小(一般不卜浇塞仅为油路的千分之一)，空气便于集中供应和远距离输送。外泄漏不会像液压传动那样，造成压力明显降低和严重污染。 (3)动作迅速，反应灵敏。气动系统一般只需要0.02s-0.3s即可建立起所需的压力和速度。气动系统也能实现过载保护，便于自动控制。 (4)能源可储存。压缩空气可存贮在储气罐中，因此，发生突然断电等情况时，机器及其工艺流程不致突然中断。 (5)工作环境适应性好。在易燃、易爆、多尘埃、强磁、强辐射、振动等恶劣环境中，气压传动与控制系统比机械、电器及液压系统优越，而且不会因温度变化影响传动及控制性能。 (6)成本低廉。由于气动系统工作压力较低，因此降低了气动元、辅件的材质和加工精度要求，制造容易，成本较低。2.2 气缸及其附件的设计倍力气缸由：前端盖，活塞，活塞杆、连接法兰、后端盖缸筒和密封件组成。因为工作要求的压力不大于1吨（即为100MPa），且按常见的现场工作压力为0.5MPa。2.2.1 气缸的设计和计算（1） 根据工作机构运动要求和结构要求，参考机械设计手册 5表38.2-1选择组合气缸中的增压气缸；参考表38.2-2选择气缸为前法兰MF1式的连接方式。活塞面积工作气压力=活塞推力 要求工作压力不大于100MPa，计算则取极限值100MPa。经计算得到活塞面积S。同时要考虑到缸筒的内径选择，查阅机械设计手册 5表38.2-4，分别选择内径为125mm和100mm的作为缸筒外径。气缸加工要求：气缸两端必须倒角，以利于缸盖装配。 为了防腐和提高寿命，缸内镀鉻，在抛光，鉻层厚度为0.010.03mm。 外表面涂漆。（2）气缸壁厚计算 结合计算结构并参考机械设计手册 5表38.2-7，最后确定壁厚为4mm。（3）活塞杆的计算并查阅机械设计手册 5最终确定活塞杆的各部分直径大小。为了便于加工和装配，最终确定活塞外径为123mm和98mm。单边留有1mm余量，便于密封件的装配。并且用螺母将活塞杆和或是固定。设定气缸的工作行程为140mm，加上活塞的厚度和余量，每个缸筒长度定位225mm。（5）连接 1.端盖和缸筒连接采用双头螺栓连接，并用O型密封圈密封。 2.活塞杆和活塞用紧固螺母固定。（6）密封，活塞杆用O型密封圈，活塞上用对装的Y型密封圈，并在中间在导向带。（7） 外联螺杆，端盖，和法兰均经行氧化发黑处理，防止生锈。第三章 自动送料机构设计由于工作压力在对操作者可能会存一些隐含的危险，因此设计送料机构为气缸输送，并在设压区加防护用钢罩和防弹玻璃。且选用导轨和滑板在输送系统中，节省空间且加润滑油后摩擦阻力更小。 3.1送料滑板设计为了更好的起到定位，并使滑板在滑轨上的运动更平稳，选择了在滑板两侧开内凹滑槽，并在加工凹槽时保证其平行度，各接触边多角。为了防止材料生锈，滑板表面进行电镀使其生成一层致密的氧化膜。滑轨则根据滑板的要求进行配加工，并且也要进行电镀处理，成对加工，保证其平行度。3.2 定位、脱模调节设计为了方便放料和在工作施压结束后，根据所需产品在滑板上设置了限位槽（图3.1）。参考产品外壳尺寸留有一定余量确定限位槽尺寸。 图 3.1送料滑板将料壳送入后，须正对施压的冲头，才能保证工作压力的恒定和工作的安全、平稳进行。设计了定位零件，其定位根据冲头的位置来定。并且其上对不同高度料壳的拔模开有长腰槽（图3.2），可以进行调节高度，并配有两个不同尺寸的脱模调节块。图 3.2所有送料机构都采用材料Q235A，并电镀进行保护处理。3.3 送料装置气缸的选择 根据设备工作要求行程，留余量取整，选择行程为了200mm缸。查阅亚德客集团气缸购买手册。选择了38mm内径（最小内径）SC型气缸，SC为标准缸，有利于节约成本。参考为设备平放气缸，固定方式选LB式。则送料装置气缸的型号确定为：SC-32200-LB。 为气缸设计一支撑座如图 3.3.第四章 清擦机构的设计4.1清擦机构设计方案分析 由于工作所对的压料为粉状，经过数次施压工作后，会有压料沾在冲头上，累积冲头上将为影响到设备的正常工作。因此设计套冲头清擦机构，并和PLC系统和气缸驱动相结合，是机构安全简单，并设定好数据后可以自动运行。由于清刷缸的动作是由文本上的清刷计数、清刷次数来控制的。当倍力气缸活塞杆回到位后，清刷计数到后，清刷缸开始对冲子清刷，清刷的次数由文本上设置而定，只有当清刷完后，才可以进入下一个产品的。在清刷过程中如有异常可按下急停开关停止清刷。4.2 清擦机构机构的确定4.2.1. 和送料机构一样，动力选择的是气缸运动来完成，所以同样也采用滑轨装置，并且选择内嵌式的燕尾槽。并采用螺钉固定在机座台面板上。滑轨要进行氧化发黑保护处理4.2.2. 用于冲头是垂直水平方向安装，而清擦气缸是水平放置，因此要清擦冲头，需要设计一个机构转换力的方向。查阅资料决定选用在滑块上带齿条装置和普通圆柱齿轮来完成。由于传动要求不高，因此采用最简单的圆柱直齿齿轮，查阅设计手册并计算后得到齿轮数据如下： 齿数： Z=18 压力角：=20模数： m=1.5 齿顶高：ha=1.5 齿根高：hf=1.875 全齿高：h=3.375齿条底部根据所选用燕尾槽尺寸进行配加工。齿条上参数如下：齿数： Z=40 压力角：=20模数： m=1.5 齿顶高：ha=1.5 齿根高：hf=1.875 全齿高：h=3.375 齿距：P=4.7124.2.3. 其它零件： 螺杆采用45号钢材，并附螺纹。表面氧化发黑处理。 螺母和擦冲板配合并和螺杆啮合，使得在气缸运动带动齿条移动，使齿轮转动，因为齿轮通过华建和螺杆连接，转动传至螺杆，在定好螺杆螺纹后，则运动会使冲擦板匀速在纵向运动从而达到清擦冲头的目的。 在冲擦板的另一头，卡位在定位挡杆上。其定位和导向作用。 其转配关系如下。4.气缸也采用同样的支承座，气缸通过计算采用型号：SC-32160-LB.第五章 机座部分机座部分包括：配重块支架、压头滑套、模框架、观察窗、台面板、底板、气缸安装板、机座、导柱。5.1 配重块 配重块是用来按照不同要求添加支撑块其上，以到达不同压力的装置。其由22mm厚的钢板和直径为76mm的钢柱焊接成。并和滑套连接配合不同要求的施压冲头以完成。5.2 安全措施 由于设备工作的压力盒压料的特殊性，特加防弹玻璃，提高操作者的安全度。5.3 台面板 台面板 起到安装模框架、底板、气缸安装板、机座的重要作用。5.4 机架 由设计要求的外型尺寸：外形尺寸：（长宽高）不大于（1000mm700mm1750mm）确定机架的尺寸。机架采用厚度为5mm的63槽钢。5.5 其余材料 其余所有材料均采用Q235A。其中配重块支架、压头滑套、模框架、观察窗、台面板、底板、气缸安装板经行氧化发黑处理，导柱电镀抛光。5.6 配重块 配重块，分为20kg、10kg、5kg、2kg、1kg五种。第六章 电路、气路控制本设备电路、气路控制主要由PLC控制系统来完成。PLC叫可编程控制器，是一种带有指令存储器，数字或模拟输入/输出接口，以位运算为主，能够完成逻辑，顺序，定时，记数和算术运算等功能，用于控制机器或生产过程的自动控制装置。 PLC控制系统有以下优点：1 数字运算操作的电子系统也是一种计算机 2 专为在工业环境下应用而设计 3 面向用户指令编程方便 4 逻辑运算、顺序控制、定时计算和算术操作 5 数字量或模拟量输入输出控制 6 易与控制系统联成一体7 易于扩充 且PLC因为是模块式的，所以扩展容易，逻辑控制优势明显，布线简单，监控方便，编程容易上手，开发周期短，快捷方便，这是其优点。电路、气路控制图如下：结合电气控制系统详细工作原理如下：HQYJ-1T电控气动压力机的动力源为压缩空气，它是通过使用倍力气缸和配重块来完成对壳体内的药剂进行压实，由于作用在壳体药剂内的力是一对相互作用力，因此在配重块不变的情况下每次压装时壳体内药剂受到的作用力是一致的。工作过程：将装有需要压装的产品模子放入送模滑板上的模具底座内，按下启动按钮后延时t秒（可调），送模气缸动作将模子送到工作位置，同时模子进出门洞关起，倍力气缸控制阀工作，活塞杆推动托模上移块将到位的模座和模子向上推起，压药冲通过脱模导冲板和导冲模进入产品壳体内压实药剂，在压力增加的过程中，压药冲将作用力传给压头和配重块支架并将起顶起上移，当支架托块上移到脱离接近开关的感应时，倍力气缸进气口停止进气，保压一定时间后倍力气缸反向进气，托模上移块下移回位，送模滑板动作将模座和模子一起送出回到起始位，在将模子从模座中取出前，送模滑板一直保持起始状态，只有当从模座内取出模子并再次放入产品后，下一个工作循环才能进行。6.1 模子送进 模子放入模座，光点传感器感应触发后延时t秒（可调），PLC接到信号后接通DY3电磁阀电源，DY3通电时换向，送模气缸进出气换向，将送模滑板及防护门拉送到位。6.2 工作过程在送模气缸将送模滑板及防护门拉送到位的同时，气缸上的磁石感应开关接通，PLC接到信号后电磁阀DY1线圈通电，电磁阀换向倍力气缸活塞杆上移到位对壳体内的药剂进行压实。6.3 保压延时在倍力气缸活塞杆上移压实壳体内药剂的同时，压头对配重块支架施加向上的作用力将其顶起，当支架托盘远离接近传感器时，PLC接到信号后给电磁阀DY2线圈通电关闭进气口，倍力气缸活塞杆输出力与配重块支架重物下压力平衡，延时t1秒（可调）后，PLC发出指令电磁阀DY1线圈断电电磁阀换向。6.4 倍力气缸回位过程PLC延期到时后，输出开关信号让DY1、DY2同时断电，电磁阀换向，倍力气缸活塞杆回位。6.5 模子送出 倍力气缸活塞杆回位时，送模块导杆同时到位触发接近开关，PLC接到信号后发出指令切断DY3电磁阀电源，电磁阀换向，送模滑板带着压制的产品送出。只有在取出产品并放入下一个产品后，下一个工作循环才能进行。6.6 清刷过程清刷缸的动作是由文本上的清刷计数、清刷次数来控制的。当倍力气缸活塞杆回到位后，清刷计数到后，清刷缸开始对冲子清刷，清刷的次数由文本上设置而定，只有当清刷完后，才可以进入下一个产品的。在清刷过程中如有异常可按下急停开关停止清刷。参 考 文 献1机械设计使用手册-机械工业出版社 主编：王少怀，徐安东，高红霞2新编机械设计手册-辽宁科学出版社 主编：蔡春源3精通 Solid Works-夸克工作室 主编：赖育良4机械设计-武汉理工大学出版社 主编：杨明忠，朱家诚5AUTO CAD 2006中文版-大连理工大学出版社 主编：余桂英6机械制造技术基础-武汉理工大学出版社 主编：曾志新7PRO/ENGINEER Wildfire 3.0-清华大学出版社 主编：卲立新，孙江宏致 谢这次毕业设计可以圆满地首先要感谢文建萍老师的大力指导，在问老师细心的指导下不仅完成了本次课程设计任务，并且在专业知识上得到了极大的补充，一定会对我以后的工作起到很大的帮助。然后要感谢学校四年的栽培，让我们在进入社会前学会了专业技能。最后要感谢工作所在公司的师傅和同事的细心帮助，使我在专业理论和实践理论上都获得了很多的宝贵经验。- 20 -各位评委老师好！设计课题：设计课题：KQYJ-1T KQYJ-1T 空气压机设计空气压机设计班班 级：级：机制机制051051姓姓 名：丁名：丁 剑剑学学 号：号：2005041120050411指导老师：文指导老师：文 建建 萍萍 动力源的选择：经过查阅资料和工作参数的要求，最后选定用压缩空气来作为设备的动力源，因此选择气压系统作为动力装置。其具有以下优点：(1)(1)介质提取和处理方便。介质提取和处理方便。(2)(2)阻力损失和泄漏较小，在压缩空气的输送过程中，阻力损阻力损失和泄漏较小，在压缩空气的输送过程中，阻力损失较小。失较小。(3)(3)动作迅速，反应灵敏。气动系统一般只需要动作迅速，反应灵敏。气动系统一般只需要0.02s-0.3s0.02s-0.3s即可即可建立起所需的压力和速度。气动系统也能实现过载保护，便于建立起所需的压力和速度。气动系统也能实现过载保护，便于自动控制。自动控制。(4)(4)工作环境适应性好。在易燃、易爆、多尘埃、强磁、强辐工作环境适应性好。在易燃、易爆、多尘埃、强磁、强辐射、振动等恶劣环境中，气压传动与控制系统比机械、电器及射、振动等恶劣环境中，气压传动与控制系统比机械、电器及液压系统优越，而且不会因温度变化影响传动及控制性能。液压系统优越，而且不会因温度变化影响传动及控制性能。(5)(5)成本低廉。由于气动系统工作压力较低，因此降低了气动成本低廉。由于气动系统工作压力较低，因此降低了气动元、辅件的材质和加工精度要求，制造容易，成本较低元、辅件的材质和加工精度要求，制造容易，成本较低 KQYJ-1T 空气压机设备在设备在220V220V交流电压和不小于交流电压和不小于0.6MPa0.6MPa的工作压力（的工作压力（常见的现常见的现场工作压力为场工作压力为0.5MPa0.5MPa）条件下：完成自动送料出入至施压点、）条件下：完成自动送料出入至施压点、给予压力和清刷冲头等功能。并要求每次给定的压力在一定的给予压力和清刷冲头等功能。并要求每次给定的压力在一定的范围内，保证效率在每分钟范围内，保证效率在每分钟620620次，所施加的压力不大于次，所施加的压力不大于1 1吨吨（即为（即为100MPa100MPa）。）。KQYJ-1T 空气压机主要参数：主要参数：外形尺寸：（长外形尺寸：（长 宽宽 高）不大高）不大于于（1000mm700mm1800mm1000mm700mm1800mm）。）。最大额定增压压力：最大额定增压压力：1T1T（100MPa100MPa）。）。最大额定输出工作压力最大额定输出工作压力:1000Kg:1000Kg。托模上移块上移的总行程：托模上移块上移的总行程：140mm140mm。工作效率每分钟工作效率每分钟6 6到到2020次。次。工作气源压力：工作气源压力：0.6Mpa0.6Mpa工作电源电压：工作电源电压：220V220V，0.1kw0.1kw。KQYJ-1T KQYJ-1T 主要组成部件主要组成部件送料机构送料机构清擦机构清擦机构 倍力气缸倍力气缸机架机架KQYJ-1T 空气压机的工作原理 HQYJ-1T HQYJ-1T空气压机的动力源为压缩空气，它是通过使用空气压机的动力源为压缩空气，它是通过使用倍力气缸和配重块来完成对壳体内的药剂进行压实，由于作倍力气缸和配重块来完成对壳体内的药剂进行压实，由于作用在壳体药剂内的力是一对相互作用力，因此在配重块不变用在壳体药剂内的力是一对相互作用力，因此在配重块不变的情况下每次压装时壳体内药剂受到的作用力是一致的。的情况下每次压装时壳体内药剂受到的作用力是一致的。模子送进模子送进模子送进模子送进 模子放入模座，光点传感器感应触发后延时模子放入模座，光点传感器感应触发后延时t t秒（可调），秒（可调），PLCPLC接接到信号后接通送模气缸电磁阀电源，送模气缸进出气换向，将送模滑板及到信号后接通送模气缸电磁阀电源，送模气缸进出气换向，将送模滑板及防护门拉送到位。防护门拉送到位。工作过程工作过程工作过程工作过程在送模气缸将送模滑板及防护门拉送到位的同时，送模气缸上的磁石感应在送模气缸将送模滑板及防护门拉送到位的同时，送模气缸上的磁石感应开关接通，开关接通，PLCPLC接到信号后，电磁阀换向。活塞杆推动托模上移块将到位的接到信号后，电磁阀换向。活塞杆推动托模上移块将到位的模座和模子向上推起，压药冲通过脱模导冲板和导冲模进入产品壳体内压模座和模子向上推起，压药冲通过脱模导冲板和导冲模进入产品壳体内压实药剂到位。实药剂到位。保压延时保压延时保压延时保压延时在倍力气缸活塞杆上移压实壳体内药剂的同时，压头对配重块支架施加向在倍力气缸活塞杆上移压实壳体内药剂的同时，压头对配重块支架施加向上的作用力将其顶起，当支架托盘远离接近传感器时，上的作用力将其顶起，当支架托盘远离接近传感器时，PLCPLC接到信号后关闭接到信号后关闭进气口，倍力气缸活塞杆输出力与配重块支架重物下压力平衡，延时进气口，倍力气缸活塞杆输出力与配重块支架重物下压力平衡，延时t1t1秒秒（可调）后，（可调）后，PLCPLC发出指令延时电磁阀开始工作，使压机对压料延时保压。发出指令延时电磁阀开始工作，使压机对压料延时保压。倍力气缸回位过程倍力气缸回位过程倍力气缸回位过程倍力气缸回位过程PLCPLC延期到时后，延期到时后，倍力气缸反向进气，倍力气缸反向进气，倍力气缸活塞杆及倍力气缸活塞杆及托模托模上移块下移回位，送模滑板动作将模座和模子一起送出回到起上移块下移回位，送模滑板动作将模座和模子一起送出回到起始位置。工作循环完成。始位置。工作循环完成。清擦清擦清擦清擦当倍力气缸活塞杆回到位后，清刷计数到后，清刷缸开始对冲当倍力气缸活塞杆回到位后，清刷计数到后，清刷缸开始对冲子清刷，清刷的次数由文本上设置而定，只有当清刷完后，才子清刷，清刷的次数由文本上设置而定，只有当清刷完后，才可以进入下一个产品的。在清刷过程中如有异常可按下急停开可以进入下一个产品的。在清刷过程中如有异常可按下急停开关停止关停止清刷。清刷。压力调整：压力调整：根据工作需要选择配重的重量，并将其摆放在配重块支架上，根据工作需要选择配重的重量，并将其摆放在配重块支架上，配重块的重量有：配重块的重量有：20kg20kg（8 8个），个），10kg10kg（2 2个），个），5kg5kg（2 2个），个），2kg2kg（4 4个），个），1kg1kg（2 2个）。个）。感谢各位评委老师！由于能力有限，设计还不是那么的完善，希望各位评由于能力有限，设计还不是那么的完善，希望各位评委老师给出宝贵的意见！委老师给出宝贵的意见！目 录 前言 .- 1 - 第一章 电控气动压力机方案设计 .- 2 - 1.1 设计任务抽象化 .- 2 - 1.1.1 建立黑箱 .- 2 - 1.1.2 功能分解 .- 2 - 1.2 确定工艺原理 .- 3 - 1.3 确定技术过程 .- 4 - 1.4 引进技术系统，确定边界 .- 4 - 1.5 确定功能结构 .- 5 - 1.5.1 技术系统总功能，及进行功能分解 .- 5 - 第二章 倍力气缸设计 .- 6 - 2.1 工作动力类型的选择 .- 6 - 2.2 气缸及其附件的设计 .- 7 - 2.2.1 气缸的设计和计算 .- 7 - 第三章 自动送料机构设计 .- 10 - 3.1 送料滑板设计 .- 10 - 3.2 定位、脱模调节设计 .- 11 - 3.3 送料装置气缸的选择 .- 11 - 第四章 清擦机构的设计 .- 12 - 4.1 清擦机构设计方案分析 .- 13 - 4.2 清擦机构机构的确定 .- 13 - 第五章 机座部分 .- 15 - 5.1 配重块 .- 15 - 5.2 安全措施 .- 16 - 5.3 台面板 .- 16 - 5.4 机架 .- 16 - 5.5 其余材料 .- 16 - 5.6 配重块 .- 16 - 第六章 电路、气路控制 .- 16 - 6.1 模子送进 .- 19 - 6.2 工作过程 .- 19 - 6.3 保压延时 .- 19 - 6.4 倍力气缸回位过程 .- 19 - 6.5 模子送出 .- 19 - 6.6 清刷过程 .- 19 - 参 考 文 献 .- 20 - 致 谢 .- 21 - 编 号 20050411 江西农业大学 工学院毕业设计材料题 目KQYJ-1T 空气压机设计专 业机械设计制造及其自动化学生姓名丁 剑材 料 目 录序号附 件 名 称数量备注1毕业设计论文12设计图纸1份二九年五月Proceedings of the 7th ICFDM2006 International Conference on Frontiers of Design and Manufacturing June 19-22, 2006, Guangzhou, China Pages 25-30 25 STUDY OF THE INFLUENCE THE INFLUENCE OF LOW ENVIRONMENT PRESSURE ON THE BEARING In ICE Feng Kai, Zhang Youyun and Xin Hao Theory of Lubrication and Bearing Institute, Xian Jiaotong University, Xian 710049, China Abstract: The influence of low environment pressure on the main bearing and big end bearing of I.C. engine was investigated based on a one-cylinder diesel engine. Firstly, a model of one-cylinder engine was set up, by the use of the commercial software EXCITE Designer from AVL company. Then, a series of experiments were done to gain the gas pressure in cylinder under different environment pressure. When the model of the engine considered the gas pressure as load, the applied load, eccentricity ratio and friction loss of the main bearing and the big end one were calculated, with the results validated by the experiments. The calculation results show that, with the decrease in environment pressure, the applied load of main bearing and big end one change, and the eccentricity ratio vary regularly, while their friction loss decrease a little. KeyWords: I.C. Engine; Low Environment Pressure; Bearing Load; Eccentricity Ratio; Friction Loss 1. Introduction Most of western China is high altitude plateau. As the increase of altitude, the air pressure and air density decrease, the air draw into the engine reduces and the combustible mixed gas becomes too dense ， so the combustion process becomes worse and dynamic behavior of the engine deteriorate significantly 1 . Under this working condition, the performance of both the main bearing and concord bearing will be affected by the drop of air pressure. So the research on the working condition of engine main bearing and concord bearing under western low pressure environment has important guiding significance for the design, manufacture and maintenance of engines working under western environment. At present, research documents on engine combustion process and dynamics influence at different altitude are usual at home and abroad 23 , but no systematic research work on the influence of low air pressure to the engine bearing appears. In this paper, single cylinder engine model considered the influence of air pressure is constructed. Using the combustion gas pressure measured through experiment under different environment pressure and different rotate speed as the input loading condition of the model, the change of the working condition of main bearing and concord bearing along with the environment air pressure under different rotate speed is calculated with business software EXCITE Designer of AVL Company, and the result is compared and validated with the experimental locus of journal center. 2. The Processing Method of low Air Pressure The influence of plateau low air pressure to the performance of engine bearing mainly comes from the deterioration of the engine dynamic behavior. In this paper, a western environment simulation engine test rig is used to simulate plateau low air pressure and measure the influence of low air pressure to the engine. The key technology of simulating low air pressure environment is how to simulate and adjust the intake pressure of the engine 4 . The exhaust pressure and the pressure in the crank shaft case are not simulated in this test system, and these works will be done later on. In the experiment, the influence of different intake pressure on the pressure in the cylinder is measured and the pressure value is loaded to the model constructed below, and then the influence of low pressure on the performance of engine bearing is worked out. The structure of the test rig is showed in fig. 1. Through the control of engine intake pressure, the simulation case can simulate the working condition of the engine under different environment air pressure. Then the pressure in the cylinder of the engine is measured by the high pressure and high temperature pressure sensor implemented in the cylinder. Due to the restriction of experimental condition, the eccentricity of the main bearing can not be measured directly, so the locus of journal center of the flywheel is measured with vortex sensor, and its eccentricity is worked out to replace that of the main bearing to validate the computational model. There are various factors which affect the combustion gas pressure in the cylinder, among which environment air pressure, rotate speed and load are especially important. Consider to run the engine with no load (the engine mainly do work to overcome friction) and measure Fig. 1 View of the Simulation Test Rig * Sponsored by National Natural Science foundation of China 26 the pressure in the cylinder under different rotate speed and different environment pressure. Fig.2 shows the pressure in the cylinder under different environment air pressure at 1000r/m. 3 The Influence of low Air Pressure on the Load of Engine Bearings 3.1 Force analysis of the piston-shafting system In order to simplify the model, it is assumed that the piston pin and rotate axis of the crank shaft are all on the central line of the piston. Then the force analysis of the engine piston-shafting is showed in fig.3. The gas pressure in the cylinder F Z is disassembled to the bearing. Fig.3 Piston-Shafting Force Analysis and Inertial Force Analysis 22 11 cos 1sin SS Z Z FF F F = = (1) 22 sin tan 1sin NN Z Z FF F F = = (2) () 2 22 sincos cos cos 1sin RZ Z FF F + = = (3) () 22 sin sin cos sin cos 1sin RZ Z FF F + = = + (4) F Z is the combustion gas pressure in the cylinder, the input load of the model; F T and F R are the forces applied on the concord big end bearing; FZ and FS are the force applied on the main bearing. 3.2 Inertial force analysis of the piston-shafting In this paper, two kinds of inertial force are considered as shown in fig.3 1) Rotate inertial force along the crank shaft radial direction 2) 1 st and 2nd order reciprocal inertial force along the piston central axis direction Disassemble to coordinate system: ( ) 0 2 01 0 cos cos cos 2 Zr Fr m mA mA = + + +K (5) 2 sin ry Fr m = (6) Through force analysis of piston-shafting of the engine, combustion gas pressure in the cylinder is disassembled to the main bearing and concord big end bearing, at the same time the inertial force caused by the movement of the piston-shafting system. The load force on the main bearing and concord big end bearing can be derived from the combination of these two kinds of force. 3.3 Calculation result and analysis of bearing load Fig.2 Gas Pressure in the Cylinder under Different Environment Pressure at 1000r/m (a) 1000r/m Main Bearing Load (b) 1800r/m Main Bearing Load (d) 1000r/m Concord Big End Bearing Load (c) 2200r/m Main Bearing Load 27 Fig.5 Main Bearing and Concord Big End Bearing under Different Rotate Speed and Different Environment Pressure Fig.5 shows that as the environment air pressure decreases, the load of main bearing and the concord big end bearing significantly reduces during the deflagration stroke, and slightly changes during other strokes. Read in and analysis the load of the main bearing and concord big end bearing during the deflagration stroke, the results are showed in form 1: Form 1 Analysis of the Load of Main Bearing and Concord Big End Bearing during Deflagration Stroke under Different Environment Pressure and Different Rotate Speed Main Bearing Environment Pressure (kPa) 97 80 60 Bearing Load (kN) 16000 13500 110001000 r/m Decrease Percent (relative to 97kPa) 15.6 31.3 Bearing Load (kN) 14000 10000 4500 1800 r/m Decrease Percent 28.6 67.8 Bearing Load (kN) 9000 5000 3000 2200 r/m Decrease Percent 44.4 66.7 Concord Big End Bearing Environment Pressure (kPa) 97 80 60 Bearing Load (kN) 32500 27500 225001000 r/m Decrease Percent 15.4 30.8 Bearing Load (kN) 28000 20000 100001800 r/m Decrease Percent 28.6 64.3 Bearing Load (kN) 20000 11500 8000 2200 r/m Decrease Percent 42.5 60.0 It shows in form 1 that the load of the main bearing and concord big end bearing will decreases along with the reduce of environment air pressure at any speed. The lower the air pressure, the more significant the load decreases. As the rise of engine rotate speed, the decrease of the deflagration load of the main bearing and the concord big end bearing augment becomes more significant. In another word, the higher the engine rotate speed, the more sensitive the deflagration load of the main bearing and concord big end bearing is to the environment air pressure. The reason of this situation is that as the engine rotate speed rises, the decrease of the pressure in the cylinder increases, then the load of the bearing reduces significantly. Further more, as the rotate speed rises, the inertial force augment, but the load of the bearing reduces under the combinational influence. However, when the rotate speed rises to 1800r/m and the air pressure drops to 60kPa, the decrease of the deflagration load of the main bearing and concord big end bearing do not change along with the rise of the engine rotate speed. It means that when the rotate speed rise to a certain extent, and the environment air pressure is low enough, the influence of the environment air pressure to the load of the bearing in deflagration process is almost the same at different rotate speed. This is because when the environment air pressure decrease to a certain extent, and the rotate speed is upper, the influence of the air pressure to the combustion in the cylinder decreases, at the same time the pressure in the cylinder is pretty high, and the effect of the inertial force is minor, so the bearing load keeps unchanged to a large extent. Fig.5(c) (f) shows the change of the load of the main bearing and concord big end bearing in relation to the crank angle at the rotate speed of 2200r/m. It shows in the figure that the decrease or increase of the load of the two bearing is not congruously along with the diminishment of the environment air pressure in the whole working process of the engine, but differ in different strokes. This phenomenon can be explained as follows: In the whole working process of the engine, the air pressure in the cylinder (F Z in formula (1)-(4) especially the combustion gas pressure in the deflagration process decreases along with the decrease of the environment air pressure, so the load of the main bearing and concord big end bearing decreases as a whole. The increase of bearing load when the crank angle is between 300 360 and -360 -300 is because the piston is in the latter half of exhaust stroke and the first half of air intake stroke at that time, and the cylinder is exchanging air with the environment; here the inertial force along the negative direction of z axis F Z is smaller than that along the positive direction of z axis, it means that the resultant force is along the positive direction of z axis, as F Z diminish, the resultant force will augment on the contrary, so the bearing load will increase. 4 The influence of low Air Pressure to the Eccentricity of the Engine Bearing 4.1 The establish of Reynolds equation and the solving of the eccentricity The Reynolds equation of the engine bearing can be expressed as 5 : () () () () () 2 33 * 1 cos 1 cos 22 6sin sin cos D BR z dd dt dz + = + (7) In which D is the diameter of the bearing bush, BR is the width of the bearing bush, is the eccentricity, (e) 1800r/m Concord Big End Bearing Load (f) 2200r/m Concord Big End Bearing Load 28 is the dynamic viscosity of the engine oil, is the minimum gap angular velocity, is the rotate speed of the journal. is the oil film pressure, t is the time coordinate, and z are dimensional coordinate. Analyze the increase and decrease process of the bearing eccentricity respectively, the relation of the differential coefficient of eccentricity and the journal rotate speed can be expressed as below: () 2 Psin cos tan / , V B B So BR D BR D null null nullnullnull (8) () 2 * sin sin / , D PB So BR D BR D = null null nullnullnull (9) In which B= S S 0 B 90 In the calculation Butenschoen method is used, and Sommerfeld number S OD and S OV can be find in reference 5, then Runge-Kutta method is used to solve the eccentricity through loop iteration. 4.2 Computing result and analysis of the bearing eccentricity Fig.6 Eccentricity of the Main Bearing and Concord Big End Bearing under Different Environment Air Pressure. Fig.6 (a) (d) show that when the engine rotate speed is under 1000r/m, both of the eccentricity shape of the two bearing shrink; fig.6 (b) (e) show that when the speed is 1800r/m, both of the eccentricity shape expand, and the deviation direction of the main bearing changed; and fig.6 (c) (f) show that when the rotate speed is 2200r/m, both of the eccentricity of the two bearing expand. We can conclude from the above figures that when the engine rotate speed is lower, the eccentricity shape of the main bearing and concord big end bearing shrink as the decrease of the environment air pressure, the lubrication condition of the bearing is improved and the bearing works more stable; when the rotate speed is higher, the eccentricity shape of the two bearing expand on the (a) 1000r/m Main Bearing Eccentricity (b) 1800r/m Main Bearing Eccentricity (c) 2200r/m Main Bearing Eccentricity (d) 1000r/m Concord Big End Bearing Eccentricity (e) 1800r/m Concord Big End Bearing Eccentricity (f) 2200r/m Concord Big End Bearing Eccentricity 29 contrary, the lubrication condition deteriorate and the bearing works unstable. At specific rotate speed, the deviation of the eccentricity may also change as the environment air pressure decreases. The load of the bearing is determined by the resultant force of the combustion gas pressure and the reciprocating inertial force of the shafting. When the rotate speed is lower, the reciprocator inertial force is lesser, and the main load of the engine bearing is caused by the combustion gas pressure in the cylinder (this is also the reason why the bearing eccentricity deflect to one side of the axis center). For this reason, the decrease of the environment air pressure causes the decrease of the pressure in the cylinder, thus the bearing eccentricity shrink. But when the engine rotate speed is higher, the reciprocating inertial force of the shafting increases and may at specific crank angle exceeds the combustion gas pressure in the cylinder if rotate speed is high enough. This makes the shape of the bearing eccentricity deflect to another side of the shaft center. At this time, when the decrease of environment air pressure causes the decrease of the pressure in the cylinder, the deflection of the bearing eccentricity also changes. As the engine rotate speed keeps on increasing, the reciprocating inertial force of the shafting exceeds the pressure in the cylinder in a bigger range of the crank angle. As a result, the bearing load is the result of the reciprocating inertial force minus the combustion gas pressure in the cylinder. When the decrease of the environment air pressure causes the decrease of the pressure in the cylinder, the load of the bearing increases and the eccentricity augments. 5. The influence of low Air Pressure to the Friction Power loss of Engine Bearing 5.1 The calculation of the friction power loss 5 If there is no direct contact between the bearing journal and bush, most of the friction power loss is caused by the shearing force of the engine oil viscosity. In this paper, only this part of friction power loss is considered. The friction coefficient () is: () () 4 sin 21 D So =+ (10) () () 2 * D D F So BR D = (11) Then the friction power loss is: () () () 2 4 * 0 42 Z FD BR D PSod = (12) 5.2 Calculation result and analysis of friction power loss of the bearing Fig.7 Friction Power Loss of the Main Bearing and Concord Big End Bearing under Different Environment Air Pressure It is figured out in Fig.7 that the power loss of the main bearing and concord big end bearing caused by the engine oil viscosity minish slightly along with the decrease of the environment air pressure. This is because the bearing load decrease as a whole when environment air pressure decreases, and the oil viscosity also reduces along with the increase of pressure 6 , thus the shearing force caused by the oil viscosity also decrease slightly, so the friction power loss reduces. Furthermore, it is shown in the fig that the influence of environment pressure to the friction power loss is relatively more significant during the deflagration stroke. This is also because the decrease of the bearing load is more severe at that time. 6. Experimental Verification Measure the locus of journal center of the flywheel with vertex displacement sensor on the “Western environment engine test rig” and calculate its eccentric, and then use it instead of the eccentricity of the main bearing to verify the computational model. (a) 2200r/m Main Bearing Friction Power Loss (a) 2200r/m,97kPa Calculated Eccentricity of the Main Bearing (b) 2200r/m,97kPa Eccentricity at the Fly Wheel Measured Through Experiment (b) 2200r/m Concord Big End Bearing Friction Power Loss 30 Fig 8 Eccentricity of Main Bearing Because of the restriction of experimental condition, the eccentricity of the main bearing can not be measured directly, so the eccentricity measured in the experiment is that of the flywheel. Because the crank shaft is flexible and will bend and distort under the stress of the concord and the engine cabinet, the eccentricity of the main bearing and the flywheel, which are at different section of the crank shaft, is apparently different. But there should be some common characteristics between them; the movement condition should be the same, and the locus of journal center should be similar. This is mainly because the main bearing and the flywheel are both on the crank shaft and the distance between them is not long, so the bend and distortion of the crank shaft is limited, thus the eccentricity shape is similar to some extent. Furthermore, because they are both on the crank shaft, and both have the same load, the change trend of the eccentricity should be the same. In this paper, the eccentricity at the flywheel measured through experiment and the calculated eccentricity of the main bearing are compared to verify the computational model. Fig.9 The movement condition of the eccentricity As shown in fig.8, it can be seen from the shape of the two graphics and the order of the marked point that both of them are moving according to the direction in fig.9 from A to B, C H in turn. Compared to fig.8 (a), point A, G and H in fig.8 (b) deflect a little to the right, and point F deflects slightly up. This is mainly caused by the distortion of the crank shaft. Through the analysis and comparison of the two figure above, we can see that the movement rule of the two eccentricity are consistent, and the shape of them are similar to some extent. So we can come to the conclusion that the computational result is verified correct and credible through experiment. 7. Conclusion In this paper, single cylinder engine model considered the influence of low air pressure to the main bearing and concord big end bearing is constructed and verified through experiment. Generally, the higher the rotate speed of the engine, the more sensitive the deflagration load of the main bearing and the concord big end bearing to environment air pressure. But when the environment air pressure decreases to a certain extent, its influence to the deflagration load of the main bearing and the concord big end bearing of high rotate speed engine no longer exist; and the influence of the environment air pressure to deflagration load of the engine main bearing and concord big end bearing is the to the same extent. Along with the decrease of environment air pressure, the eccentricity of the main bearing and the concord big end bearing change regularly. When th