三缸星型蒸汽发动机模型图纸
AS-T-T014 SQR372发动机机械
2、气门传动组
（1）、曲轴正时齿轮 将曲轴转到1缸 上止点位置，使曲 轴正时齿轮上的正 时记号与机油泵壳 体上的正时记号对 齐，如左图所示。
正时记号
图21
。
（2）、凸轮轴正时牙轮 材料：粉末冶金
牙数：44 键槽：对正牙根 安装：排气凸轮轴 注意：在装正时齿带 时，不装火花塞，首先 确认凸轮轴正时齿轮上 止点标记与缸盖前端的 标记对正如右图所示 所示。 右 所示
（3）、活塞销与销孔
活塞销座孔：偏离中心 1、2±0、1 活塞销座孔在活塞 分组时，也同样分组， 其分组记号打印于活塞 顶部： A代表18.001-18.0035。 B代表18.0035-18.006。 活塞销分二组：
半浮式活塞销
活塞销重量：67g； 材料：15Cr(20Cr)； 半浮式：连杆小头加温150C°安 装。
（2）、气缸盖
作用：密封汽缸顶部， 形成燃烧室 燃烧室形状： 帐篷型（屋脊型） 材料：铝合金 压铸成型。 要求：下表面不平度：0、03。 与缸盖装配有二个定位孔。 气门导管装配过盈量： 0、040~0、066 寝入液氮冷冻压入； 气门座圈过盈量： 0、121~0、087冷冻压入。 缸盖螺栓扭紧力矩分三次循环： 30 ±2；50 ±3；70±3、 5N•m。 螺孔除油从中向两边 交叉扭紧。
三、SQR372 冷却系统
组成及循环水路
溢流罐 发动机
水 泵
暖 风 散热器
节温器
冷却系统作用
。
1、作用： 发动机作功行程中，燃料燃烧产生高温，将高温受热零件的热量散 到大气中去，却保发动机维持在一个正常工作温度范围（85~115ºC）。 原理： 借助媒介的循环流动，高效将零件热量带走，再向空气进行热交换。 2、方式： 离心泵，强制循环水冷式。 3、水路： 小循环： 水泵—水道—水套—节温器—水泵； 大循环： 水泵-水道-水套-节温器-散热器-水泵。 4、风扇：双温开关，ECU控制，两速单电动风扇。低速为94ºC时开； •降致91 ºC关；高速在105ºC时打开，降致101ºC时再变为低速。在打开空 调时冷却 风扇自动打开，风冷冷凝器。
发动机理论知识大全
4、油底壳
油底壳的功用是储存机油和封闭机体或曲轴箱。
油底壳用薄钢板冲压或用铝铸制而成。油底壳内设有挡板， 用以减轻汽车颠簸时油面的震荡。此外，为了保证汽车倾 斜时机油泵能正常吸油，通常将油底壳局部做得较深。油 底壳底部设放油螺塞。有的放油螺塞带磁性，可以吸引机 油中的铁屑。
活塞组
活塞连杆组由活塞、活塞环、活塞销、连杆、连杆瓦等组成。
油环的主要功用是刮除飞溅到气缸壁上的多余的机油，并 在气缸壁上涂布一层均匀的油膜。
此外，气环和油环还分别起到刮油和密封的辅助作用。
3、活塞销
活塞销用来连接活塞和连杆，并将活塞承受的力传给连杆 或相反。活塞销与连杆小头的连接方式有两种，即全浮式 和半浮式。
全浮式活塞销工作时，能在连杆小头和活塞销孔中转动， 而半浮式只能在活塞销孔中转动，不能在小头孔内转动 。
3)裙部 活塞头部以下的部分为活塞裙部。裙部的形状应保 证活塞在气缸内得到良好的导向，气缸与活塞之间在任何 工况下都应保持均匀的、适宜的间隙。
另外，沿活塞轴线方向活塞的温度是上高下低，活塞的 热膨胀量自然是上大下小。因此为使活塞工作时裙部接 近圆柱形，须把活塞制成上小下大的圆锥形或桶形。
2、活塞环
燃烧室具备的条件
1、结构紧凑、提高热效率 2、增大进气门或进气道、提高发动机转矩和功率 3、压缩行程终点产生挤气涡流、保证充分燃烧 4、保证火焰传播距离最短（汽油机） 5、形状与燃油喷射、空气涡流运动进行良好配合（柴油机）
3、气缸衬垫
气缸衬垫是机体顶面与气缸盖底面之间的密封件。 其作用是保持气缸密封不漏气，保持由机体流向 气缸盖的冷却液和机油不泄漏。 按所用材料的不同，气缸衬垫可分为金属—石棉 衬垫、金属—复合材料衬垫和全金属衬垫等多种。
2AZ发动机简介
VVT是英文缩写，全称是“Variable Valve Timing”，中文意思是“可变气门正时”。本发动机的控制器安装在进气凸轮轴上的，称为螺旋槽式VVT－i。螺旋槽式VVT－i控制器（如下图）包括正时皮带驱动的齿轮、与进气凸轮轴刚性连接的内齿轮，以及一个位于内齿轮与外齿轮之间的可移动活塞，活塞表面有
轮系布置-----------------------------------------13
排放系统-----------------------------------------13
电控系统-----------------------------------------14
油路分析-----------------------------------------14
一、基本结构性能参数-----------------------------------------2
二、采用的新结构，新材料，新技术。
全铝结构的优点-----------------------------------------2
VVT的原理与优点-----------------------------------------3
图五、纵向进气道
火花塞与润滑油接触是发动机常见故障，Tritec 1.6L专门安装了火花塞套管，其压装在气缸盖上，使火花塞及高压线免受油污，且维修保养方便。2AZ/FE采用的方法是缸盖上直接铸有火花塞套管，其最高点仍可能处于润滑油液面以下，故在气门室罩盖垫上设计有密封该套管的密封圈。
缸盖的后端是水路出口，缸盖前端正中和缸盖上端正中布置有大空间水套的出沙工艺孔，其直径为25.40mm。缸盖螺栓为10根，每缸四根，均匀分布在缸盖周围，如图二（B）。
第一节汽车发动机的类型及工作原理
发动机冷却水循坏方式动感视图
(3) 按照气缸数目分类
发动机按照气缸数目不同可以分为单缸发动机和多缸发 动机。仅有一个气缸的发动机称为单缸发动机；有两个 以上气缸的发动机称为多缸发动机。如双缸、三缸、四 缸、五缸、六缸、八缸、十二缸等都是多缸发动机。现 代车用发动机多采用四缸、六缸、八缸发动机。
大众系列
W型发动机的特性？
优点：结构更紧凑，可以容纳更多的汽缸数，有更大的排 量。
缺点：结构太复杂，运转平衡性也不好。
由于专利的原因，这种发动机只在大众和奥迪，布加迪等 少量车上可以见到，在欧版大众高尔夫、欧版大众帕萨特 以及奥迪A8上，分别装备着W6,W8和W12发动机。
转子发动机
转子发动机全称为三角活塞转子发动机。
2.发动机基本术语
发动机汽缸工作术语动感视图
1.上止点
活塞离曲轴回转中 心最远处，一般指 活塞上行到最高位 置，一般用英文缩 写 词 TDC 表 示 。
2.下止点
活塞离曲轴回转 中心最近处，一般指 活塞下行到最低位置， 一般用英文缩写词 BDC 表 示 。
3.活塞行程（S）
上、下止点间的距离。
1
L型发动机
2
V型发动机
3
H型发动机
4
W发动机
5
转子发动机
6
水平对置发动机
7
转子发动机
什么是L型发动机呢？
又称“直列”(LineEngine)发动机，是指汽缸是按直线排 列的，它所有的汽缸均按同一角度并排成一个平面。“直 列”一般用L代表，后面加上汽缸数就是发动机代号。
思考L3、L4、L5、L6代表的含义？ L3：表示直列3缸发动机。 L4：表示直列4缸发动机。 L5：表示直列5缸发动机。 L6：表示直列6缸发动机。
发电厂蒸汽动力循环示意图
h4
h3
wp
c,oi
h3
h4 h3
c,oi
１
2 2 s
11-2 再热循环
一、蒸汽再热循环
1
qin
Boiler
7 Reheater
H.P
High-P turbine
L.P
Low-P turbine
蒸汽再热循环系统 示意图
wturb,out
wpump,in
5
Pump 3
8
9
Condenser
力Mpa ～ ～
3.0
～
8～
14
亚临 界
亚临 界
超临 界
33.5
40
1.0 3.0 8.0
再热次 数
一次 二次 二次 二次
注：临界压力：22.12 MPa, 临界温度：374.15 ℃ • 第一台试验性超临界125MW机组（31 MPa,621/566/538℃）,1957年在美国投运。
第二台超临界325MW机组（34.4 MPa,649/566/566℃）,1959年在美国投运。
水泵的相对内效率
p
wp wp
１
2 2 s
五、实际循环的计算 T
已知 p1, t1, p2 ,oi ,c,oi
求 q1, w0 ,t
4
关键： 得到 h2 , h4
4
因
oi
wt wt
h1 h2 h1 h2
3
p
wp wp
h4 h3 h4 h3
所以 h2 h1 oiwt h1 oi h1 h2
p01 1kg
柴油机活塞建模与结构设计说明书(格式已修改好)
辽宁工程技术大学课程设计题目：柴油机活塞建模与结构设计班级：汽车05-1班学号： 0507130108姓名：黄永波指导教师：刘克铭完成日期： 2009-01-05一、设计题目（学生空出，由指导教师填写）柴油机活塞建模与结构设计二、设计参数CY4100ZLQ柴油机，活塞直径D=100mm，工作行程S=118mm，直接喷射方式,发动机转速n=3200r/min，额定功率P e=70KW，最大扭矩T tqmax=235N.m,几何压缩比ε=17.5，最大燃烧压力P Z=6.1Mpa，增压空气压力P K=0.1518Mpa。
三、设计要求（1）总装图1张（2）零件图2张（3）课程设计说明书（5000～8000字）1份四、进度安排（参考）（1）熟悉相关资料和参考图2天（2）确定基本参数和主要结构尺寸2天（3）设计计算3天（4）绘制总装配草图4天（5）绘制总装配图2天（6）绘制零件图2天（7）编写说明书3天（8）准备及答辩3天五、指导教师评语成绩：指导教师日期摘要本课程设计的主要内容是柴油机活塞建模与结构设计，在课程设计中完成的工作有：给定参数下活塞的结构设计和三维建模。
在绘图上，采用CAXA软件，提高了工作效率。
在三维建模上，采用Pro/ENGINEER软件，完成了活塞实体、活塞环和活塞销的建模工作，及时的发现了结构设计中的错误。
在课程设计过程中，通过查阅相关资料，初步掌握了活塞设计的步骤和方法。
在查找资料过程中，深刻体会到书籍检索的重要性，在实践中也摸索出一套自己的资料检索方法。
同时，也熟悉了各大专业技术论坛。
活塞设计涉及到的知识面比较广，需要在良好掌握工程材料、材料力学、发动机原理、工程热力学、机械加工和汽车构造等课程的基础上，才能较好的完成设计任务。
同时，对于各种软件的熟练操作也十分必要。
通过本次课程设计，使我对所学的知识做了一个较为全面的回顾，有助于从中找出自己的不足之处。
认识到在工程材料及工程热力学方面知识结构较为浅薄，实际计算能力较差，急需加强。
桑塔纳2000轿车结构与维修—第3章GSi电喷检修31
第三章桑塔纳2000GSi型轿车AJR型发动机电控系统的结构与维修第一节桑塔纳2000GSi型轿车AJR型发动机电控系统的组成桑塔纳2000GSi型轿车的AJR型发动机采用了德国波许（BOSCH）公司最先进的Motronic3.8.2电子控制多点汽油顺序喷射系统。
它是在AFE型发动机Motronic1.5.4系统基础上发展起来的。
该系统采用热膜式空气流量计检测发动机进气流量，可直接反映发动机负荷，比Motronic1.5.4系统所采用的绝对压力传感器检测进气歧管压力并推算流量的方法更精确。
AJR型发动机的曲轴上装有1个60齿的信号触发轮，用于产生曲轴转角信号，它比AFE型发动机的分电器中由4齿触发轮产生的转角信号更为准确。
M3.8.2系统能依据进气流量信号和曲轴转角信号准确地控制发动机混合气空燃比和点火时间，从而极大地降低了汽车排气污染。
发动机具有自我诊断系统，但是必须用专用仪器方可读出控制单元（ECU）中储存的故障代码。
发动机也同样具有备用功能，例如当水温传感器线路有断路故障时，ECU就认为水温始终是19.5℃。
备用功能用于在控制系统、传感器、执行元件发生某些故障时，维持发动机运转，以便汽车开到修理厂。
采用新的排气系统。
将消声器的管径由Ф50mm改为Ф45mm，并对原消声器的内部结构进行了调整，从而降低了车内噪声，提高乘坐的舒适性，同时又使发动机保持良好的动力性能。
采用了汽油蒸汽控制回收系统（AKF系统）。
汽油蒸汽控制回收系统采用活性炭罐吸附油箱中挥发的汽油蒸汽，在发动机起动后，再把炭罐中吸附的汽油吹出燃烧，减少废气排放，更为节能。
AJR型发动机上装有2个爆震传感器，比AFE型发动机增加了1个，使ECU能更有效地识别各个气缸的爆震燃烧，迅速调整点火时间，保护发动机免受劣质汽油引起的强烈爆震的损害。
采用两个点火线圈，即使用了双火花点火系。
M3.8.2电子控制汽油喷射系统由空气供给系统、汽油供给系统、控制系统组成，AJR 型发动机电子控制系统的结构示意图如图3-1所示，其组件在车上的布置如图3-2所示，AJR 型发动机电子控制系统的组成如图3-3所示。
CA柴油机的连杆三维造
CA4110柴油机的连杆三维造型当进入PRO/E Wildfire（野火版）的零件模式的用户界面，见图1。
在其上方是主菜单，见图2，与PRO/E2002相似，但把菜单管理器的主要功能都合并到主菜单中（编辑、插入）和简化成右下方、下方（在执行功能时出现）的图标，从而基本取消了菜单管理器，更加便于操作。
图1 零件模式的用户界面图2 主菜单对于常用的特征建模命令在右下方的图标中显示出，其中是拉伸实体或剪切实体图标；是旋转生成实体或旋转剪切实体图标；是创建可变截面扫掠特征；是创建边界混合特征。
由于连杆杆身形状复杂，所以先从杆身做起。
杆身是一个复杂的变截面实体，首先要根据杆身外形建成一些曲线，再由这些曲线建立曲面，相当于蒙在杆身表面上的一层皮（绸缎面），在将这些曲面进行剪裁、缝合、充实成杆身实体结构。
具体做法如下：在造型之前要进行零件的工艺、装配关系设计目的的分析，要是零件的参考坐标系与工艺基准、设计基准和装配基准相一致。
在连杆设计中，连杆大头孔是设计基准、工艺基准和装配基准，因此以大头孔作为零件的参考坐标系。
在装配图中，曲轴图形在FRONT平面上，图 3 草绘的基准曲线而连杆是套装在曲柄销上，因此连杆的绘图平面垂直于FRONT平面，为RIGHT平面。
参照平面为FRONT平面。
1.创建杆身曲线连杆杆身截面是一变化的工字钢，相对于FRONT平面和RIGHT平面是对称的，因此只考虑四分之一的杆身，可用四条曲线绘制出杆身变曲面的轮廓。
第一条曲线是在RIGHT平面，杆身的最大轮廓曲线；第二条曲线与第一条不在一个平面上，且曲线上的各点也不在同一平面上，因此以曲线最高点所在平面为绘图平面，即大约离RIGHT平面18mm的于RIGHT平面平行的平面，根据图样技术要求，连杆的拔模斜度为5~7度，因此第二条曲线与第一条曲线错位18≈=6⨯；第三条曲线与第二条在同一平面上，并近似认为与第tg9.1mm892.1二条曲线形状一样，只是向连杆中心线平移mm5.5=⨯-；第四条曲线186tg6.3与第一条在同一平面（RIGHT平面），形状与第二条相似。
AVL报告_周长辉_T843-6-4 (2)
摘要本文主要介绍了AVL BOOST 软件模拟仿真 EQ6102 发动机的过程，将EQ6102发动机配气相位作为优化参数，依次把进排、气们提前角和迟闭角作为优化自变量，以发动机动力性和经济性为目标，对发动机配气相位进行优化。
关键词：AVL BOOST ，EQ6102 发动机，配气相位，优化，动力性，经济性目录摘要 (1)1 EQ6102发动机模型建立 (3)1.1 BOOST模型介绍 (3)1.2 建立EQ6102柴油机的BOOST模型 (7)1.2.1 模型元素 (7)1.2.2 BOOST模型的建模 (7)1.2.3 参数输入 (8)1.3 计算BOOST模型并分析运算接过 (17).1.1 A VL制作模型介绍表1 EQ6102 发动机的基本参数型号EQ6102型式立式、直列、直喷、水冷、四冲程、中冷缸径×行程(mm) Φ102×115排量 5.638压缩比16.5:1排放标准EUROII额定功率(kW) 105最大扭矩(N*m) 405最大扭矩转速(r/min) 2400-2600燃料柴油点火顺序1–5–3–6–2-4进气冷却方式中冷长×宽×高(mm) 1270×698×880适配车型8-12m、客车、6t以下载货车表2 边界条件输入表表3 计算模型中管子数据表缸径：102mm冲程：118mm压缩比：16.5连杆长度：220mm活塞销偏移：0曲轴箱的平均压力：1bar 扫气模型：Perfect Mixing 点火提前角：715deg燃烧持续角：75deg形状因子m：0.85 Parameter a：6.9活塞：表面积：14000平方毫米壁面温度：276.85摄氏度活塞标定系数：1缸盖：表面积11000平方毫米壁面温度：246.85摄氏度缸盖标定系数：1缸筒：表面积：500平方毫米壁面温度（活塞上、下止点时）：176.85摄氏度、86.85摄氏度缸筒标定系数：1气缸内涡流比：1.9全局变量：General Control：Species Transport：Classic计算任务：循环模拟计算，缸内，柴油机发动机转速：2500rpm参考条件：压力：1bar，温度：298KTime Step Control：循环：4-Stroke最大计算周期：Engine Cycles 20计算步长：1deg，Traces Saving Interval：3deg点火顺序：1-5-3-6-2-4表4 测量点的定义数据表1.2建立EQ6102 柴油机的BOOST模型1.2.1模型元素该模型由36 个元素构成，具体如下：6 Cylinders（6 个气缸）元件符号名:C1 Junction （1 个连接点） J1 Air Cooler （1 个空气冷却器） CO3 Plenums （3 个容腔元件） PL2 System Boundaries（2 个系统边界） SB6 Measuring Points （6 个测量点） MP17 Pipes（17 个管道元件） Numbers图1 EQ6102 柴油机的基本模型1.2.2 Boost 模型的建模1.将元件布置到建模区域通过点击鼠标从所显示的元件树上选择需要的元件，将如前所述的元件，气缸、空气冷却器、容积腔、系统边界和测量点按顺序分别布置到相应的建模区域。
发动机的分类PPT幻灯片课件
按混合气形成方式分为：化油器式发动机、直接喷射式发动机； 按是否对进气增压分为：非增压式发动机、增压式发动机； 按发动机安装位置分为：前置发动机、中置发动机、后置发动机；
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课堂小作业：
1.现在汽车上的发动机是靠（ ）工作的。
A.热力 B.水力 C.风力 D.以上都是
（1）点燃式发动机（如汽油机、气体 燃料发动机）Spark Ignition, SI
AUDI V12 TDI EURO5 （2）压燃式发动机（如柴油机） Compression Ignition, CI
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按冷却方式分类
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水冷式
1、水冷式发动机：以水为冷却 介质的发动机。
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风冷式
2、风冷式发动机 以流动的空 气为冷却介质的发动机。
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按气缸数分类
单缸发动机 多缸发动机
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单缸发动机
仅有一个气缸的发 动机
仅有一个气缸的发动机，多采用在摩托车、拖拉机等上面。
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多缸发动机
有两个气缸及以上 的发动机
有两个气缸及以上的发动机，目前采用在汽车上的有：双缸 →三缸 →四缸→五缸→六缸→八缸→十缸→十二缸→十六缸。
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5、混合燃料发动机：同时使用电、气、
液其中两种燃料的发动机 。
18
混动（混合动力）发动机
以宝马的混动为例：
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20
按工作循环的冲程数分类
21
四冲程发动机
四行程发动机B.swf
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二冲程发动机
二行程发动机B.swf
23
按发火方式分类
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例如：
Mercedes Benz AMG M157
活塞阀引擎模型制作说明(1)
Instructions for making aPiston Valve Enginefrom mainly junk materials.by John (“Bogstandard”)on thePaddleducks Forum at/forum/viewtopic.php?t=2872&postdays=0&postorder=asc&start=0Document NotesThe length of this document has necessitated its being split into smaller portions to comply with file upload limitations on host servers.Consequently, it has been arbitrarily divided into six chapters, plus an appendix containing the design sketches in full size (also sub-divided into two parts). While this may not be as convenient to users as single file, it nevertheless permits the file to be made available in the first instance, and it will facilitate downloads for those with limited Internet access. (Note that internal document hyperlinks do not work in the PDF version of the document.)The text and accompanying photos and sketches have been extracted from posts by “Bogstandard” (John) to the Paddleduck’s Forum over the period May to July, 2007, describing the step-by-step design and build of a model steam engine.Also included are those comments, suggestions and questions that were posted to the Forum during the build period and which are considered to add to the knowledge transfer by other members of the Forum.For reference purposes, the Chapters contain the following pages:Chapter 1 – Cover page to page 14Chapter 2 – Pages 15-29Chapter 3 – Pages 30-45Chapter 4 – Pages 46-60Chapter 5 – Pages 61-73Chapter 6 – Pages 74-84Appendix 1/Part A – Pages 85-100Appendix 1/Part B – Pages 101-113CHAPTER 1 (1)Introduction/Tools Required (1)Safety (2)Project Overview (2)Main Block - Now (3)Machining Notes (4)To Get Square out of Round (4)Metalworking Guides (5)Comment – Milling Vice Datum Face (6)Comment - Tolerance Adjustment (7)Drilling Block Holes (7)Reaming the Block Holes (8)Top Caps, Packing Glands and Pistons (10)Crossheads (12)CHAPTER 2 (15)Main Block Mounting Holes (15)First Holes: Top caps and gland seals (15)Second Holes: Block Mounting Plate (16)“Tweaking” Tips (16)Engine Turning (17)Crosshead Support Bars (18)Building Up (18)Bearing Blocks (19)Tip- Lapping Bearing Blocks (21)Baseplate (22)Comment - Boiler (23)Crankwebs Part 1 – Blanks (and Flywheel) (24)Comment - Crankweb Fabrication & Jig (25)Milling Caution (26)Crankwebs Part 2 - Shaping (26)Crankwebs Part 3 - Crankshaft Assembly (27)Comment – Crank Positioning (29)Comment – Crankshaft Construction (29)CHAPTER 3 (30)Eccentrics (30)Conrods (33)Question – What Speed/Reverse Control? (33)Comment – Fourth Main Bearing (34)Steam Chest Intro (Piston Valve Control Block) (34)Steam Chest – Part 1 (35)Comment – Drilling Deep Holes - Introduction (39)Comment - Small Boring Tool (41)Comment – Deep Hole Drilling - General notes (41)Response – Deep Hole Drilling (41)Steam Chest Blanking Plate (42)Response – Deep Drilling, Tooling Availability (43)Comment – Tapping Holes (44)Response – Helicoils, Spool Valves (44)Comment – Cutting Fluids (45)CHAPTER 4 (46)Initial Assembly (46)Tip – Reamers (46)Prepared for 1st Run (47)Comment – Regulator/Throttle, Video (48)Response – Video, Throttle (48)Spool Valves (48)Explanation – Valve Operation (50)Comment – Variation in Engine Speed (51)Response – Speed Variations (52)Comment – Running on Compressed Air (52)Response – Compressed Air (52)Eccentric Straps (53)Eccentric Connecting Joint (54)Piston Valve Packing Gland (55)Comment – Live Steam (56)Steam Flanges - General (56)Steam Flanges – Holes and Tubes (58)CHAPTER 5 (61)Silver Soldering (61)Silver Solder - Problems (63)Flanges – Drilling Out (64)Steam Control Block – Part 1 (65)Comment – Pickling Solution Options (66)Response – Pickling Solution (66)Steam Control Block – Soldering (67)Comment – Chamfer? (68)Response – Chamfer (68)Comment – High Silver Content Solder (69)Steam Control Block – Part 2 (70)Lubricator (73)Valve Timing (74)Question – Match Marking and Torque Settings (77)Response – Match Marking and Torque Settings (77)Tip – Packing Steam Glands (77)Comment – Finding True Dead Centres (79)Tip – Locating Top Dead Centre (81)Comment – Lack of Comments (82)Custom Engine (82)Question – Milling the Custom Block (84)Answer (84)Question – Tightening Bolts (84)Answer (84)APPENDIX 1 – Design Sketches (85)CHAPTER 1Introduction/Tools RequiredHaving carried out a full site poll, half way down a topic somewhere and having immense response, really, I have decided to show how I build my engines from scratch (and junk), hopefully to inspire at least one person to have a go.This opening post will be to try and convince you that making is not too difficult or overly expensive if you just have a few basic engineering tools.Its always nice to have a fully equipped workshop, but even by buying a cheap lathe, Arc Eurotrade do one for just over £100 with maybe another £50 for some basic bits to go with it, can work wonders for your modelling, not just engineering, you can make most of your metal, wood and plastic fittings yourself.A small vertical slide to fit the lathe will allow you to do not only basic milling but more complicated things as you get used to it. In fact what I do is use the machines to make more bits for the machines. An el cheapo drill press is a worthwhile investment, and can be obtained everywhere for just over £30.For basic hand tools I use an engineers square, a little gizmo for finding the centre of roundish thingies, its actually called a centre square; again you can buy sets of these from somewhere like Chronos for just over £25 (this is great, spending someone else’s money).A selection of files, scriber, a good six inch rule, centre punch, hammer, the list goes on, but most people have the necessary things already, you can buy purpose made deburring tools, but I use a Stanley knife, by scraping the sharp edges at 45 deg, instant deburr, just change the blade every couple of months.A flat surface and a sheet of very fine wet & dry takes care of lapping any faces, I used a piece of plate glass until recently, in fact it was the platen glass out of an old photocopier, (it only needs to be about 12" square), I had used it for about the last ten years, not just for lapping but anytime I needed a flat surface, just scrape the glue off before using it to lap. Unfortunately, glass, big lumps of metal and fumbling fingers don't mix.A cheap digital vernier calliper is a very good investment. Last one I bought was about £9 from Aldi.Please bear in mind, with the machinery I have I can easily remove 5 or 6mm at a time, with a very small lathe or miller you will be lucky to remove one tenth of this, so you have to do a lot of small cuts. Usually the larger the machine the better, what will do a lot will also do a little, but not the other way round.I am not saying that you could build an engine like this on the small lathe that I mentioned, but I would love you to prove me wrong. That was just to show that it needn't cost a fortune to start in engineering. Now a few of my famous drawings showing the basic setup for calculating what is needed. This engine will not be a good looker by any stretch of the imagination; it looks very spindly, that is because again I have gone for the same bore and stroke 10X20 long stroke.The next bit I submit will be even more long winded than this, because I want to mention a little about safety in a workshop environment. It needs to be done, and I promise, only the once. I have picked up more body parts from people alive and not so alive than I care to remember, so I can talk thru experience. Digest this lot if you can, will do the next post either late tonight or early tomorrow. It will get better.SafetyBefore I go any further, the most boring bits, but the most important. Ignore the warnings at your ownperil!!! If you can't follow the basic rules, you shouldn't be anywhere near this post!!!!From now on alcohol is banned from the workshop. Well that’s got rid of 99% of the readers; we'll just carry on without them. In fact I'm most probably writing this post to myself.Safety is a must, the eyes need careful protection, without them your modelling days are over; get a pair of safety glasses, AND USE THEM!!!!.Machinery has no feelings; it will take your fingers off just as easily as it removes metal. Keep your bodily bits away until the machine has stopped. Long hair and shirt cuffs have an affinity for moving parts. Remember, don't become another piece of your latest project.Metal that has been machined produces heat, and a lot of it. When I'm cutting some tough stuff it actually glows. Let it cool down before you touch it, and for goodness sake don't drop hot metal into water to cool it down, you might find that the metal has become hard as glass and you won't be able to do any more machining operations on it.When metal has been machined, very sharp edges are produced; it will cost you a fortune in plasters. Don't put away a piece of metal until it has been properly deburred. In fact I deburr after every operation, if you don't, aside from the safety aspect will, if put against a datum face, will throw all your machining calculations out of the window.It seems mundane, but getting splinters of metal in you skin can have drastic repercussions. Get a piece of brass embedded in your skin and leave it for a few days, the puss filled, weeping, gory open festering wound will wish you had got it out with a pair of tweezers as soon as it got in there. Remember there will be minute bits of metal everywhere, keep your hands away from it, sweep it up or better still get an old vacuum in there and suck it up as often as needed.If you can add any more please do, I can't think for everyone, it is up to you to keep yourself safe and healthy, no-one else - YOU!!!. In fact in industry you can be prosecuted for having an accident, lose your fingers, get prosecuted, what a bummer. But you only do it the once.Lecture over, it does get better, but it had to be said.Project OverviewThe Main reason you are reading this.Project - To build a twin cylinder slide valve steamengine with the same bore and stroke as my previousoscillator, namely 10mm bore x 20mm stroke. Thiswill allow parts designs from my previous engine tobe used with this one. This will save a lot of timehaving to design new parts. All measurements aremetric. Hopefully there will be no 'bit' measurements; Iwill try to keep everything to the nearest 1/2mm. I amalso building in a few adjustable bits for those of uswho are not quite as accurate (Pic 01).Please be aware that I design and make as I goalong, aided by a few sketches. If anyone wants tobuild one you will have to strip it down and measure it01up, and give me a copy of the drawings.Or else ask and I will post what workings sketches I have. Pic 02 and Pic 03 are more examples of the type of sketch I’m talking about and depict the other key dimensions of the engine.I will be building two engines in parallel so if you see two of everything don't worry, I am hopefully going to make one horizontal, and not by drinking alcohol.Most of the raw materials for this build will come from theyard of many skips, or have been donated freebies frompeople that say "give it to that nutter John, save us having totake it to the tip". Little do they know about the cost of rawmaterials!95% of my raw materials for building are not the correct sizeor shape - you have to go with an open mind and envisagewhat is in there trying to get out. I expect this engine -excluding fasteners - to cost me less than £10 in rawmaterials. Your local scrap man will become your best friend,slip him a couple of quid and he will be happy to hack oldmaterial into smaller bits, it will save hours in the workshoptrying to cut it down yourself.Throw no materials away. If while machining say a bit ofbrass and you cut off a 10mm long piece to get to size, don'tthrow that piece away, if you cut a bolt down, anything youcut off over say 6mm long, save it, great for making studsand joiners, saves time as well. Nothing is truly done for untilit can no longer be used for anything else. It is people thatdon't follow these rules that get me all the raw materials fromthe scrapman.The one thing that I do invest in is good quality fasteners,and I get them from here - /. If it is not on the sitejust give them a call, only about 10% is shown on the sitebut they stock everything in stainless screwed fasteners, butonly in metric I think, up to 4mm, and very reasonably pricedas well. By the way: I have no affiliation to these suppliers,other than being a very satisfied customerWhat I do is during the build I use any old crappy screws that I have lying around, and when the engine is up andrunning I put shiny new ones in.Main Block - Now to start (and hopefully finish!)Metal for the main block or 'How to hopefully recycle a useless bit of metal into a bit of metal with a use'Pic 04 - The junkman’s moll, gentlyeased apart to show the temptingsecrets within.Pic 05 - With even more teasing furthertreasures are revealed.05 02Pic 06 - After an hour’s hard fumbling the sheer beauty isrevealed, silky smooth, soft to the touch and a delight tofondle.Pic 07 - Hacking off the outer skin to get a nice squareblock.Not bad for a lump of scrap cast iron from the scrap yard that cost 30p (35mm cast iron bar, over £10 if bought from a metal supplier, over 90p per inch). Will be able to get about 6 engine blocks (5p each) out of one sash weight and is most probably up to a hundred years old and you won't get much better seasoned material than that.This has been a long haul post but it sets things into the correct frame of mind. Just to reiterate:- safety first and foremost,- clean and deburred,- get to know your friendly scrapman,- don't be put off if you bodge it up, and- if it can be put right it was never wrong in the first place.Lay back a little. Metal doesn't just up and run away out of your chuck or vice (unless of course you didn't tighten up enough then it will chase you round the workshop), so take your time, the world won't end if you don't get the bit machined tonight, go and have a pint, be nice to the missus for a change. It is when you rush, get tired, fed up or whatever that accidents and mistakes happen, it will still be there in the morning. You are not in a production environment, unlike Sandy, who has to get things out on time otherwise his employees don't eat. Get to enjoy yourself, because if you don't enjoy it you shouldn't be doing it.I don't use tolerances (this is a designed figure that you can work to, and if kept within the figures willensure that the mating parts will fit together and carry out their designed function). Because these engines would be classed as prototypes, I make everything to fit individually. If you go slightly over or under on the bores, make the pistons to fit, the grim reaper won't call just because one bore is 0.02mm bigger than the other. So I try to keep to exact size, but I don't worry if not.Machining NotesTo get an idea of using a vertical slide on a lathe, when you see a picture of my milling setup, swing the picture thru 90 deg and imagine the cutter being in your lathe chuck and the vice as being the vice on your vertical slide, you can do everything I can do with my miller, maybe not as quickly, but as mentioned above, why rush.Use a dial test indicator for setting the fixed jaw of your machine vice totally parallel and square to the cutting action of the cutter. This can be done without a DTI just by machining a piece of metal and measuring the results.The fixed jaw of the vice now becomes your datum face, don't move it unless you really have to. After you have been doing any heavy cutting, check it again, just in case it has moved.To Get Square out of Round .Put material in vice, and face off the side. Then clean off the swarf, deburr both cut edges and remount into vice putting the now flat face against the datum jaw. Take a cut across the face, this will give you two sides square to each other, again clean and deburr.The face you have just cut goes down into the vice with the same datum face that you used before against the fixed jaw. I set my piece onto parallels and tap the material onto that until it just grips the parallels, thatway I know that everything will be square and parallel. But if the jaw is square to the base of the vice you07should be ok.Now machine the third side down to the required thickness, again, as usual, clean and deburr.Put the first machined side down into the vice with one of the now machined and parallel sides against the fixed jaw, tap down the material and then cut the fourth side down to required thickness.If all is well you should now have a piece of bar that has opposing faces parallel and square to adjoining faces.If you can get this right everything else is almost easy.Metalworking GuidesHere is a website to give you a few basic instructions in metalworking, and explains things a lot easier than I can - http://www.nmri.go.jp/eng/khirata/metalwork/index_e.html . There is some pigeon English but most of it is understandable.If there is anything at all that you don't understand, just go to Google and type in what you want, i.e. 'using a vertical slide' or 'how to use a boring bar in the lathe'; the answers to most questions will give you all the info you require and just add the sites to your favourites for later reference.Pic 08 shows a lot more than you think.I have already faced one end of the cylinder block, now isthe time to get it to the right dimension.At the bottom left and right of the picture are two of mymost useful bits on the lathe. The right hand one is thesaddle clamp that locks the saddle solid, the left hand oneis a saddle stop that I made for this lathe, it doesn't haveto be this complicated but it can stop you ruining yourlathe.It stops the toolpost going too far and hitting the chuck,08usually with irreparable damage. This is usually a fairly simple thing to make and you will wonder how you ever lived without it. The way I use it for facing is bring the saddle to it and lock the saddle. Then I can use the top compound slide to give very fine cuts without having to worry about the saddle being pushed back by the pressure of the cut.I am using my four jaw chuck to hold the material, the material doesn't have to be centralized when end facing, in fact with a little bit of ingenuity the whole block could have been machined in the four jaw.I am a stickler for a good surface finish, and will spend hours lapping and polishing, so you will notice that I have used a bit of cut up drinks can (I prefer Pepsi Max, but almost any will do) between the jaws and the material, this is to protect the surface finish, chuck jaws are very hard and will mark most materials. On the metal sticking out of the jaw, near to the cutting tool, you can just notice a felt tip mark near to the end. This allows me to rough cut up to that mark, leaving me about 1/2mm to go to length. Then I take a very fine facing cut (maybe 0.02mm: 0.001"). Then remove the piece from the chuck and measure the length. This will tell you how much you have left to come off to get to size. Remount in chuck with Pepsi Max, bring the tool to just touching the face then take your cuts, the last one being like before, very fine. You will find that you should have now a piece of material to the correct length.The last bit in this picture is rather indistinct, that is the cutting tool itself. I started using one of these so called 'profile' tools about 5 years ago, and it is one of my most prized possessions in getting my own backagainst lumps of metal. They are obtainable from a lot of places but here is about the cheapest -/Go to the bottom of the page and all will be explained. I bought five tips for it when originally purchased - I am just on the last one now. The beauty of these is that when the tip wears you just turn it a few degrees and you have a brand new cutting edge, and the surface finish is superb. About £3 a year running costs, not bad, and it is used daily for facing, reducing to size and of course a little bit of profiling.Pic 09 is the blocks finished to size, blued up (this is notreally necessary, but you don't have to scribe such a deepline to see it) and marked out for the job tomorrow, namelyputting the big holes in.Oh! and a little message for Eddy, here is the first wart (orpimple), the block was a bit tight to get out of the roughcast material and is in fact 0.15mm (0.006") too short onthe height, but as I said, don't worry; all I will do is take thesame measurement off the top of the piston and all will beright with the world.09Comment – Milling Vice Datum FaceComment - Tolerance AdjustmentMany thanks for the comments, all duly noted.Hopefully the article will not now be as long winded. I just wanted to get across the basic understanding of machining metal and what is involved, and put over how I cope with the odd situations.The eccentric bit did confuse me because you switched ends half way thru. The way I see it now, is that when viewed from the output end (the end connected to the shaft), engine going in a clockwise direction, with the nearest piston in the fully upstroke position, the eccentric will be 90deg to the right, the rear piston is on its downstroke and its big end at 90 degrees to the right (the same position as the front eccentric) and its eccentric 90 degrees forward of that at full bottom stroke, or should the rear piston be on its upstroke and it's eccentric be at the same position as the front pistons big end? Or doesn't it matter? When I asked about direction of rotation of props: as far as I'm concerned, on the full size it is pointy bit at front, blunt bit at back, don't know what’s underneath, can't see it unless I get wet. On models, as far as I was aware, you always went for the safety factor and a single screw always went anticlockwise when viewed from the rear, so the shaft was screwing the prop on tighter (the same as the port side setup when viewing a twin output).Drilling Block Holes - Now to get back on track.I will sometimes mention a couple of words that need a bit of explaining and they are related. These are CONcentric and ECcentric.Concentric means in our situation that the outside diameter has the same centre as the inside diameter, a good example is a well made washer.Eccentric means the outer and inner diameters have different centres, like the holes on a button, stick it on a shaft and spin it and it wobbles up and down.Found this site today - /vms/library.html .Almost everything you need to know about using the things and operations I use on the lathe and milling machine can be found here. Be very careful though, if you are just starting out in machining the hours will fly by while surfing on this site. Videos and all sorts on here.When drilling holes bigger than 2mm you should always if possible use a centre drill, if drilling large holes say of above 6mm, egg 10mm. Start with the centre drill, then use something like 4mm followed by one around 7mm, then 9mm and finish off with the 10mm. You will find that the holes will be a lot more accurate than stuffing a 10mm straight in.For sheet metal drilling I find that cone drills do a wonderful job, they don't snatch when breaking through. Pic 10 shows centre drills and cone drills (another great buy from Aldi).Pic 11 shows the steps I will use to drill the bores through the main block. I will finish off with a 10mm reamer, but if doing it on a lathe you can bore the holes or just drill them either mounted into a four jaw chuck or vertical slide, but you must make sure that you don't drill into the holding chuck or vice. Two other things to note on this picture. The first is showing block sitting on parallels to allow drills to penetrate right thru without doing any damage. The other is that just behind the block is what is called a back stop, this allows me quickly to flip the block around and without having to re-measure, drill the second hole. Backstops are also used on a lathe; I will point it out when I come to use one.Pic 12 shows cylinders bored and reamed. The surface finish in the bore looks really grotty, but in real life they are like a mirror.Work has now finished on the blocks for the time being, the next bit is to make and fit the pistons and rods.Reaming the Block Holes - Back to the article.I said last time that we had finished with the blocks for the moment.I forgot that not all of you will have the means to get a good enough finish on the bore: they will most probably vary from a slightly dull surface, thru what looks like screw cutting to digging out the hole with a hammer and chisel.If you can borrow a reamer, and your hole is still slightly undersize, use one, otherwise this is how I would get an acceptable finish. You can go out and buy adjustable laps, but that costs a lot, just to get a coupleof holes cleaned out, this isn't the totally correct way but it will be better than what you've got at the10moment.Start with the largest hole, stick the last drill you used through them and wiggle about side to side, the one with the biggest wiggle is the biggest hole.Mark the largest hole with a felt tip. Now chuck up a piece of material to make the lap out of, have it sticking out of the chuck by 1.5 times the length of the hole plus 25mm (1"), I use hard nylon but aluminium or brass will also suffice, I get better results with the softer materials.Carefully (no heavy cuts here, material sticking a longway out of chuck) and turn down the rod until it justpushes through the hole for a length of 1.5 times thelength of hole (like Pic 13).Now we need to spend a bit of money unless you arefrom the old school and have some in your garage. Weneed to buy some fine and coarse grinding paste,Halfords is about the cheapest at about £3 and you geta grinding stick with that as well. This quantity will lastyou for the rest of your life.Dab a bit if the coarse stuff along the length of the lap,you don't need a lot. Get a piece of hardwood and with a13rolling action in combination with turning the chuck byhand (you have stopped the lathe I hope) embed the surface of the lap with grinding paste, what you are doing is making a very accurate round file.Select the lowest speed on your lathe and switch on. Keeping well away from the chuck feed the hole to be lapped onto the lap, get ready to let go on this initial feed in just in case it bind up and sticks. If all is well the lap will be turning (without you going round with it) in the hole. Now just gently move the block up and down the lap in a sort of rotary twisting motion. You need to keep the lap fully into the hole at all times.Change the block position 90 deg around the lap every so often, eventually you will get the feel and a rhythm going.Do this for a couple of minutes, stop machine and check the bore, it should have started to smooth out. Repeat as necessary, wipe off, recharge, turn the block around and come from the other end of the hole, until the rough stuff has gone, then wipe off coarse grinding paste with white spirits and recharge with fine. Repeat the operation.You should after a while end up with a nice round, parallel bore showing slight scratch marks on the surface, these scratches will help the bedding in process as they retain oil while the pistons and bores are wearing against each other.Clean off the grinding paste and turn down the lap to fit the smaller hole, and repeat the process again. When finished give the bores a very good clean out to get rid of any remaining grinding paste.If you remember from before, the pistons are going to be made to fit the bores, so they don't need to be the same size.Put the lap you have just made in a safe place, you might make something else where you can readjust the size and use it again. I will do the pistons in the next article; it will give time for the batteries to recharge on my camera.。