曲柄连杆机构课程设计

工程软件训练1目录目录······································································································1第1章绪论··························································································3第2章活塞组的设计············································································42.1活塞的设计··················································································42.1.1活塞的材料·········································································42.1.2活塞头部的设计···································································42.1.3活塞裙部的设计····································································52.2活塞销的设计···············································································52.2.1活塞销的结构······································································5第3章连杆组的设计············································································63.1连杆的设计··················································································63.1.1连杆材料的选用···································································63.1.2连杆长度的确定···································································63.1.3连杆小头的结构设计·····························································63.1.4连杆杆身的结构设计·····························································63.1.5连杆大头的结构设计·····························································63.2连杆螺栓的设计············································································7第4章曲轴的设计···············································································84.1曲轴的结构型式和材料的选择··························································84.1.1曲轴的结构型式···································································84.1.2曲轴的材料·········································································84.2曲轴的主要尺寸的确定和结构细节设计··············································84.2.1曲柄销的直径和长度·····························································84.2.2主轴颈的直径和长度·····························································94.2.3曲柄··················································································94.2.4平衡重···············································································94.2.5油孔的位置和尺寸·······························································104.2.6曲轴两端的结构··································································10工程软件训练2第5章曲柄连杆机构的创建································································115.1活塞的创建·················································································115.2连杆的创建·················································································115.3曲轴的创建·················································································11第六章曲柄连杆机构静力学分析·························································136.1活塞的静力分析···········································································136.2连杆的静力分析···········································································13工程软件训练3第1章绪论曲柄连杆机构是发动机的传递运动和动力的机构，通过它把活塞的往复直线运动转变为曲轴的旋转运动而输出动力。因此，曲柄连杆机构是发动机中主要的受力部件，其工作可靠性就决定了发动机工作的可靠性。随着发动机强化指标的不断提高，机构的工作条件更加复杂。在多种周期性变化载荷的作用下，如何在设计过程中保证机构具有足够的疲劳强度和刚度及良好的动静态力学特性成为曲柄连杆机构设计的关键性问题[1]。通过设计，确定发动机曲柄连杆机构的总体结构和零部件结构，包括必要的结构尺寸确定、运动学和动力学分析、材料的选取等，以满足实际生产的需要。在传统的设计模式中，为了满足设计的需要须进行大量的数值计算，同时为了满足产品的使用性能，须进行强度、刚度、稳定性及可靠性等方面的设计和校核计算，同时要满足校核计算，还需要对曲柄连杆机构进行动力学分析。为了真实全面地了解机构在实际运行工况下的力学特性，本文采用了多体动力学仿真技术，针对机构进行了实时的，高精度的动力学响应分析与计算，因此本研究所采用的高效、实时分析技术对提高分析精度，提高设计水平具有重要意义，而且可以更直观清晰地了解曲柄连杆机构在运行过程中的受力状态，便于进行精确计算，对进一步研究发动机的平衡与振动、发动机增压的改造等均有较为实用的应用价值。本文以捷达EA113汽油机的相关参数作为参考，对四缸汽油机的曲柄连杆机构的主要零部件进行了结构设计计算，并对曲柄连杆机构进行了有关运动学和动力学的理论分析与计算机仿真分析。工程软件训练4第2章活塞组的设计2.1活塞的设计2.1.1活塞的材料在发动机中，灰铸铁由于耐磨性、耐蚀性好、膨胀系数小、热强度高、成本低、工艺性好等原因，曾广泛地被作为活塞材料。但近几十年来，由于发动机转速日益提高，工作过程不断强化，灰铸铁活塞因此比重大和导热性差两个根本缺点而逐渐被铝基轻合金活塞所淘汰。铝合金的优缺点与灰铸铁正相反，铝合金比重小，约占有灰铸铁的1/3，结构重量仅占铸铁活塞的%70~50。因此其惯性小，这对高速发动机具有重大意义。铝合金另一突出优点是导热性好，其热传导系数约为铸铁的4~3倍，使活塞温度显著下降。对汽油机来说，采用铝活塞还为提高压缩比、改善发动机性能创造了重要的条件。共晶铝硅合金是目前国内外应用最广泛的活塞材料，既可铸造，也可锻造。含硅9%左右的亚共晶铝硅合金，热膨胀系数稍大一些，但由于铸造性能好，适应大量生产工艺的要求，应用也很广。综合分析，该发动机活塞采用铝硅合金材料铸造而成。2.1.2活塞头部的设计1、压缩高度的确定压缩高度1H是由火力岸高度1h、环带高度2h和上裙尺寸3h构成的，即1H=1h+2h+3h（1）第一环位置一般汽油机Dh)12.0~06.0(1，D为活塞直径，该发动机的活塞标准直径mmD80确定火力岸高度为：mmDh8801.01.01（2）环带高度一般气环高mmb5.2~5.1，油环高mmb5~2。该发动机采用三道活塞环，取mmb5.11，mmb5.22，mmb33。环岸的高度c，Dc)05.0~04.0(1，12)2~1(bc，汽油机接近下限。则mmDc405.01，工程软件训练5mmbc35.12212。因此，环带高度mmbcbcbh14335.245.1322112。（3）上裙尺寸对于汽油机DH)0.6~0.35(1，所以mmDH40805.05.01。mmhhHh18148402113。2、活塞顶和环带断面由于EA1135V1.6L发动机为高压缩比3.9，因而采用近似于平顶的活塞。实际统计数据表明，活塞顶部最小厚度，汽油机为D)0.1~0.06(，即mm6)80075.0(。2.1.3活塞裙部裙部单位面积压力（裙部比压）按下式计算：2maxDHNq取mmDH368045.045.02。则799.0368083.2410qMPa一般发动机活塞裙部比压值约为MPa5.1~5.0，所以设计合适。2.2活塞销的设计2.2.1活塞销的结构活塞销与活塞销座和连杆小头衬套孔的连接配合，采用“全浮式”。活塞销的直径Dd)3.0~25.0(1，取mmDd2025.01，取mmdd147.012活塞销长度Dl)9.0~8.0(，取mmDl648.0工程软件训练6第3章连杆组的设计3.1连杆的设计3.1.1连杆材料的选用为了保证连杆在结构轻巧的条件下有足够的刚度和强度，采用精选含碳量的优质中碳结构钢45模锻，表面喷丸强化处理，提高强度。3.1.2连杆长度的确定设计连杆时首先要确定连杆大小头孔间的距离，即连杆长度l它通常是用连杆比lr/来说明的，通常~25.00.3125，取27.0，mmr23.40，则mml15023.4027.0。3.1.3连杆小头的结构设计连杆小头主要结构尺寸如图4.1所示，小头衬