第9讲螺纹连接件的画法.

1、1 第九讲 螺纹连接(Threads) 螺纹要素及分类 Key Elements and types 内外螺纹画法 Representations of internal and external threads 螺纹联接 Threaded connection 1.螺纹紧固件 Threaded fasteners 2 螺孔螺孔 Threaded hole 3 9.1 螺纹的形成、结构和要素螺纹的形成、结构和要素 Generation , structure and key elements of thread 螺纹的形成螺纹的形成Generation A 螺旋线螺旋线 Helix 一个与轴线

2、共面的平面图形（三一个与轴线共面的平面图形（三 角形、梯形等），绕圆柱面作螺旋运角形、梯形等），绕圆柱面作螺旋运 动，则得到一圆柱螺旋体动，则得到一圆柱螺旋体 螺纹。螺纹。 A cylinder thread is a long narrow projection of uniform cross the section in the form of helix ont the surface of a cylinder 制在圆柱体制在圆柱体外表面外表面上的螺纹叫上的螺纹叫外外 螺纹螺纹。External thread is a thread on the outside of a cylin

3、drical surface ,as on a shaft. 制在圆柱体制在圆柱体内表面内表面上的螺纹叫上的螺纹叫内内 螺纹螺纹。Internal thread is a thread on the inside of a cylindrical surface, as in a hole. 4 车外螺纹车外螺纹 Lathe external thread 车内螺纹车内螺纹 Lathe internal thread 工件工件 A Shaft 卡盘卡盘 Fixture 车刀车刀Cutter 工件旋转工件旋转 The part rotates 车刀沿轴向移动车刀沿轴向移动 The cutter

4、move along the axis 2. 螺纹加工螺纹加工 Machining screw thread 5 螺纹的要素螺纹的要素Key Elements of threads 螺纹的牙型螺纹的牙型 Form of thread 三角形三角形 Metric 在通过螺纹轴线的剖面上，螺纹的轮廓形状。在通过螺纹轴线的剖面上，螺纹的轮廓形状。The cross section of thread cut by a plane containing the axis. 梯形梯形 ACME 锯齿形锯齿形 Buttress 常用的有：常用的有：Most often used: 牙型牙型 Form 6

5、螺纹的大径和小径螺纹的大径和小径 Major diameter and minor diameter 大径大径：与：与外螺纹牙顶外螺纹牙顶或或内螺纹牙底内螺纹牙底相切的假想圆柱面的直相切的假想圆柱面的直 径。径。D、d Major diameter: The largest diameter of a screw thread 小径小径：与：与外螺纹牙底外螺纹牙底或或内螺纹牙顶内螺纹牙顶相切的假想圆柱面的直相切的假想圆柱面的直 径。径。 D1、d1 Minor diameter: The smallest diameter of a screw thread 牙顶牙顶 Crest 牙顶牙顶 C

6、rest 牙底牙底Root 牙底牙底 Root 小径小径 大径大径 7 外螺纹外螺纹 External thread 内螺纹内螺纹 Internal thread 牙顶牙顶 Crest 牙底牙底 Root 牙底牙底Root 牙顶牙顶 Crest 大径大径Major Dia. D、d 小径小径 Minor dia. D1、 d1 中径中径Pitch dia. D2、d2 螺纹的中径螺纹的中径Pitch diameter： 一个假想圆柱的直径。该圆柱的母线通过牙型一个假想圆柱的直径。该圆柱的母线通过牙型 上上沟槽和凸起宽度相等沟槽和凸起宽度相等的地方。的地方。The diameter of an

7、imaginary cylinder where the thread width is equal to space between the threads. 8 螺纹的线数螺纹的线数Number of threads 沿沿一条螺旋线一条螺旋线形成的螺纹叫做形成的螺纹叫做单线单线 螺纹螺纹；Single thread: with only one start. 沿沿两条或两条以上两条或两条以上在轴向等距分布在轴向等距分布 的螺旋线所形成的螺纹叫做的螺旋线所形成的螺纹叫做多线螺多线螺 纹纹。Multiple thread: with two or more starts 单线螺纹单线螺纹 Si

8、ngle thread 双线螺纹双线螺纹 Multiple thread 瓶口三线螺纹瓶口三线螺纹 Triple-start thread 9 螺距和导程螺距和导程 Pitch and Lead 螺纹上相邻两牙在中径线上对应两点之间的轴向距离螺纹上相邻两牙在中径线上对应两点之间的轴向距离P 称为螺距。称为螺距。Pitch: The distance from a point on one thread to the corresponding point on the adjacent thread, measured parallel to the axis of the thread. 同

9、一条螺纹上同一条螺纹上相邻两牙在中径线上对应两点之间的轴向相邻两牙在中径线上对应两点之间的轴向 距离距离L称为导程。称为导程。Lead: The distance a thread advances axially in one turn. 单线螺纹单线螺纹(Single thread)： P=L多线螺纹多线螺纹(Multiple thread)： P=L/n 螺距螺距P =导程导程L 螺距螺距P 导程导程L 10 螺纹的旋向螺纹的旋向 How the thread spiral 右旋右旋(常用常用) :顺时针旋转外螺纹时旋入的螺纹为右旋。除非特别顺时针旋转外螺纹时旋入的螺纹为右旋。除非特别

10、注明，螺纹均为右旋注明，螺纹均为右旋 Right-hand(Default)：A thread is always considered to be right-hand unless otherwise specified. 左旋左旋:加标记：加标记：“LH” Left-hand：always labeled LH on drawing 注意注意：只有上述：只有上述五要素完全相同五要素完全相同的内、外螺纹的内、外螺纹 才能旋合在一起。才能旋合在一起。The external thread and internal thread can be mated only when their fiv

11、e elements are all the same . 右旋右旋 Right-hand左旋左旋 Left-hand 右边升高右边升高 Slant upward to the right 左边升高左边升高 Slant upward to the left 11 螺尾螺尾Thread runout 倒角倒角 Chamfer 牙顶牙顶Crest 牙底牙底 Root 牙型牙型Thread form 中径中径 Pitch dia. 牙型牙型 Thread form 小径小径Minor dia. 螺距螺距Pitch 螺距螺距 Pitch 外螺纹外螺纹External thread内螺纹内螺纹Inter

12、nal thread 大径大径Major dia. 内外螺纹旋合三要素：内外螺纹旋合三要素：牙型、大径、螺距牙型、大径、螺距 Three key elements for mating : thread form, major dia. and pitch 12 退刀槽退刀槽Thread relief螺尾螺尾Thread runout 螺纹收尾和退刀槽螺纹收尾和退刀槽 Thread runout and relief 退刀纹退刀纹Incomplete thread due to tool exits 开始退刀开始退刀 Cutting tool begins to exit 退出车刀退出车刀 E

13、xit completely 外退刀槽外退刀槽External relief 内退刀槽内退刀槽Internal relief 退刀纹退刀纹 Incomplete thread 13 9.2 螺纹的种类螺纹的种类 Classification of threads commonly used 螺纹螺纹 Thread 连接连接 螺纹螺纹 Connecting 传动传动 螺纹螺纹 Transmitting 普通螺纹普通螺纹Metric thread 管螺纹管螺纹Pipe thread 粗牙螺纹粗牙螺纹Coarse 细牙螺纹细牙螺纹 Fine 梯形螺纹梯形螺纹Trapezoidal thread 锯齿

14、形螺纹锯齿形螺纹Buttress thread 密封管螺纹密封管螺纹Screw-sealed 非密封管螺纹非密封管螺纹Non-screw-sealed 14 联接联接 螺纹螺纹 Conne -cting 传动传动 螺纹螺纹 Transm- ission M G Tr B 粗牙粗牙 Coarse 细牙细牙 Fine 螺螺 纹纹 Metric 管管 螺螺 纹纹 Pipe thread 梯形螺纹梯形螺纹 Trapezoidal 锯齿形锯齿形 螺纹螺纹 Buttress 普普 通通 是最常用的联接螺纹是最常用的联接螺纹 Most often used connecting thread 用于细小的精密

15、或薄壁零件用于细小的精密或薄壁零件 Used for fine or thin part 用于水管、油管、气管等薄用于水管、油管、气管等薄 壁管子上，用于管路的联接。壁管子上，用于管路的联接。 Used for connection of pipes or tubes of water, oil or gas 用于各种机床的丝杠，作用于各种机床的丝杠，作 传动用。传动用。Power transmission, like in lead screw. 只能传递单方向的动力。只能传递单方向的动力。 Transmit power in one direction only, like in a ca

16、r jack 螺螺 纹纹 种种 类类Types 特征特征 代号代号 Labels 外外 形形 图图 Profiles 用用 途途 Use 常用的几种螺纹的特征代号及用途常用的几种螺纹的特征代号及用途 The labels and common uses of some threads 15 9.3 螺纹的规定画法螺纹的规定画法Conventional representation of threads 牙顶用粗实线表示牙顶用粗实线表示 (外螺纹的大径线，内螺纹的小径线外螺纹的大径线，内螺纹的小径线)。 The crest line ( i.e. major dia. for external

17、thread and minor dia. for internal thread) defined by thick solid line. 牙牙底用细实线表示底用细实线表示 (外螺纹的小径线，内螺纹的大径线外螺纹的小径线，内螺纹的大径线)。 The root line ( i.e. minor dia. for external thread and major dia. for internal thread) defined by thin solid line. 在投影为圆的视图上，表示牙底的细实线圆只在投影为圆的视图上，表示牙底的细实线圆只画约画约3/4圈。圈。 On an end

18、 view, the root should be represented by a circle of approximately 3/4 of the circumference drawn by thin solid line . 螺纹终止线用粗实线螺纹终止线用粗实线表示。表示。The thread end lines (The limits of useful thread) should be shown by a thick solid line. 不管是内螺纹还是外螺纹，其剖视图或断面图上的不管是内螺纹还是外螺纹，其剖视图或断面图上的剖面线剖面线 都必须画到粗实线都必须画到粗实线

19、。For threaded parts shown in a sectional view ,The section lines should be extended to the thick solid lines. 16 螺纹终止线画螺纹终止线画 粗实线粗实线Thread end line by thick solid line 外螺纹画法外螺纹画法 Representation of external threads 小径线画细实线且画到倒角内小径线画细实线且画到倒角内Minor dia. by thin solid lines and extended cross the chamfe

20、r line 小径小径0.85d 倒角圆不画倒角圆不画 Chamfer circle not shown on such view 小径圆约画小径圆约画3/4圈圈 Minor dia. by a thin solid line circle of approximately 3/4 外螺纹剖视画法：外螺纹剖视画法： Section of external thread: 小小径径 大径大径 AA 螺纹终止线画一小段螺纹终止线画一小段 Thread end line appears short 剖面线画到粗实线剖面线画到粗实线 Section lines extended to thick so

21、lid lines A A 大径线画粗实线大径线画粗实线 Major dia. by thick solid lines 17 螺纹终止线螺纹终止线 Thread end line by thick solid line 内螺纹画法内螺纹画法 Representation of Internal threads 大径线画细实线大径线画细实线 Major dia. by thin solid lines 小径线画粗实线小径线画粗实线，0.85d Minor dia. by thick solid lines and extended cross the chamfer line 倒角圆不画倒角圆

22、不画 Chamfer circle not shown on such view 大径圆约画大径圆约画3/4圈圈Major dia. by a thin solid line circle of approximately 3/4 剖面线画到剖面线画到粗实线粗实线 Section lines extended to thick solid lines A A AA 18 120 0.5D 不穿通螺纹孔的画法不穿通螺纹孔的画法Blind tapped hole: 钻孔钻孔 Drill 攻丝攻丝 Tap 19 C2 螺纹局部结构的画法螺纹局部结构的画法 倒角倒角Chamfer 退刀槽退刀槽Reli

23、ef 螺尾螺尾 Runout 245 245 b 与轴线成与轴线成30细实线细实线 Thin solid lines 30to the axis 螺尾只在有要求时螺尾只在有要求时 才画，不需标注。才画，不需标注。 Runout not shown unless its required. P505表表 20 AA 4. 螺纹联接的画法螺纹联接的画法Representation of threaded connection A A 旋入深度旋入深度 Length of screwed 大径线和大径线对齐；小径线和小径线对齐。大径线和大径线对齐；小径线和小径线对齐。 Two major diame

24、ters are collinear, so does the two minor diameters. 旋合部分按外螺纹画；其余部分按各自的规定画。旋合部分按外螺纹画；其余部分按各自的规定画。 For threaded connection part, external thread covers internal thread. 按不剖画按不剖画 As non-sectioned 内、外螺纹剖面线方向相反内、外螺纹剖面线方向相反 Reversed section lines for internal and external threads 为什么？为什么？ 21 画图步骤画图步骤Step

25、s： 画外螺纹（小径画画外螺纹（小径画0.85d ） External thread (Major dia. as 0.85d) 确定内螺纹的端面位置确定内螺纹的端面位置 Determine the location of internal thread ends 画内螺纹及其余部分投影画内螺纹及其余部分投影 Finish the remaining part of internal thread. 22 9.4 螺纹的标注螺纹的标注 Thread designation 标注的基本模式标注的基本模式 General symbols 螺纹代号螺纹代号 Designation of thread

26、s 公称直径公称直径 Nominal dia. 螺距螺距 或或 导程导程(P螺距螺距) Pitch or Lead (P 长长Long：L 中等中等Middle：N 短短Short：S 中径和顶径中径和顶径 公差带代号公差带代号 23 标注示例标注示例 Example M 20 2 LH -5g6g - s 普通螺纹普通螺纹 Metric thread 大径大径Major dia. d20 螺距螺距 2 (细牙细牙) Pitch is 2 (fine thread) 短旋合长度短旋合长度 Short engagement length 顶径公差带代号顶径公差带代号 Major dia. tol

27、erance zone 左旋左旋 Left- hand 中径公差带代号中径公差带代号 Pitch dia. tolerance zone 例例1： 例例2： Tr407(14/2)7HL 梯形螺纹梯形螺纹 Trapezoidal thread 大径大径Major dia. D40 螺距螺距 7导程导程14,双线螺纹双线螺纹 Pitch is 7, lead is 14 ,double thread. 中径、顶径公差中径、顶径公差 带代号带代号Major dia. and pitch dia. tolerance zone 长旋合长度长旋合长度Long engagement length 右旋右

28、旋 Right hand 两公差相同则只标一个。小写字两公差相同则只标一个。小写字 母表示外螺纹，大写字母表示内母表示外螺纹，大写字母表示内 螺纹。螺纹。If the two tolerance zone symbols are the same, only one indicated。Capital for internal and small for external threads. P502 24 M202 标注方法标注方法 Thread notes M20-7H G1 外螺纹外螺纹 External 尺寸界线应尺寸界线应 从大径引出！从大径引出！ The extension line

29、s should be from the major dia. 管螺纹管螺纹 注：注： G后面的数字不后面的数字不 是管是管螺纹的大径螺纹的大径 ，而是它的公称，而是它的公称 直径。直径。The value after letter “G” is not the major dia. but its nominal dia. 内螺纹内螺纹 Internal 1 in = 25.4mm P504 P502 25 9.5 螺纹紧固件的标记和画法螺纹紧固件的标记和画法Threaded fasteners 常用的螺纹紧固件有：常用的螺纹紧固件有：螺栓、螺钉、螺柱、螺母和螺栓、螺钉、螺柱、螺母和 垫圈等

30、垫圈等。由于这类零件都是标准件，通常只需在装配图。由于这类零件都是标准件，通常只需在装配图 中用简化画法画出，同时给出其规定标记。中用简化画法画出，同时给出其规定标记。 标记方法按标记方法按 “GB” 有关规定。有关规定。 Threaded fasteners, which include bolts, screw, stud, nut and washer etc., are standardized. On assembly drawings they are specified by means of designations and shown in conventional repr

31、esentation. Designation according to “GB” 26 六角螺母六角螺母 Nuts P 513 规定标记规定标记 Specified designation： 螺母螺母 GBGB/T T 6170 M12M12 2d 0.8d 简化画法简化画法 Simplified drawing： 国标号国标号 GB symbol for nuts 螺纹规格螺纹规格 Thread size 例：例： 比例画法见比例画法见P414 图图15-20 See P414 Fig. 15-20 for proportional drawing as 27 六角头螺栓六角头螺栓 Bol

32、ts P506 规定标记：规定标记：Specified designation 螺栓螺栓GB/T 5782 M1280 （由设计决定）（由设计决定） Determined by design 0.7d L 2d d 0.1d45 简化画法：简化画法： Simplified drawing 螺栓长度螺栓长度L Length of stud L 例：例： 比例画法见比例画法见 P414 图图15-20 See P414 Fig. 15-20 for proportional drawing as 28 垫圈垫圈 Washers P514 规定标记：规定标记：Specified designatio

33、n 垫圈垫圈GB/T 97 12 简化画法简化画法Simplified drawing ： 规格规格,指用于指用于M12的螺栓或螺柱的螺栓或螺柱 Size 12 means that it is used for M12 bolts or studs 0.15d 1.1d 2.2d 例：例： P514为平垫圈，为平垫圈，P515为弹簧为弹簧 垫圈垫圈 P514 shows plain washers while P515 about spring washers 29 螺钉螺钉 Screws P511 规定标记：规定标记： Specified designation 螺钉螺钉GB/T 65 M

34、845 0.2d 0.3d 1.5d d 0.6dL 2d 0.1d45 开槽圆柱头螺钉开槽圆柱头螺钉 Slotted cheesed head screw 简化画法：简化画法： Simplified drawing 例：例： P508 内六角圆内六角圆 柱头螺钉柱头螺钉 Hex. Socket cheese head screw P510开槽沉头开槽沉头 螺钉螺钉 Slotted countersunk head screw 螺钉长度螺钉长度L Length of screw L 30 螺栓联接螺栓联接 Bolt joints 9.6 螺纹紧固件装配图的画法螺纹紧固件装配图的画法 Repre

35、sentation of fasteners in assembly drawing 用于将两个都有通孔的用于将两个都有通孔的 零件联接零件联接Used to hold two parts together each of which has a through and clearance hole. 31 1 L 螺栓联接装配图画法螺栓联接装配图画法 Drawing of bolt joints Ld=1+ 2+0.15d(垫圈厚垫圈厚 height of washer) +0.8d(螺母厚螺母厚height of nut)+0.3d 螺栓、垫圈、螺母沿轴线剖到按不剖画螺栓、垫圈、螺母沿轴线

36、剖到按不剖画 Bolt, washer and nut as non-sectioned along the axis 螺栓的有效长度按下式计算螺栓的有效长度按下式计算 Design length of the bolt is calculated as : 将将Ld与标准规定的公称长度系列与标准规定的公称长度系列L比较，选择最接近于计比较，选择最接近于计 算值的公称长度。（算值的公称长度。（P506) Compare the length Ld with the nominal length L series specified in the standard and choose the

37、one closest to the calculated value. 两块板的剖面线方向相反两块板的剖面线方向相反 Reserved directions of section lines for two parts 0.3d 2 被联接件的孔径被联接件的孔径=1.1d Holes in two parts drawn as diameters of 1.1d 螺栓大径为螺栓大径为d Major dia. Of the bolt is d 参见参见P416 图图15-23 Refer to P416 Fig. 15-23 32 画图步骤画图步骤 Steps: 先画俯视图较方便先画俯视图较方

38、便 Top view first recommended 33 2. 螺钉联接螺钉联接 Screw joints 螺钉连接用于受力不大螺钉连接用于受力不大 且不要求调整的机构。且不要求调整的机构。 Screw joints are used on machines requiring few adjustments and lower strength. 光孔光孔 Clearance hole 螺纹孔螺纹孔 Tapped hole 34 bm L 0.5d 旋合长度旋合长度bm与被零件材料有关与被零件材料有关: Length of screwed bm is determined by mat

39、erial of jointed part: 钢钢Steel： bm=d 铸铁铸铁Cast iron: bm=1.25d 铜铜Copper: bm=1. 5d 铝铝Aluminum: bm=2d 螺钉计算长度：螺钉计算长度： Length calculated by: Ld=bm+ 查表定查表定L -P511 Find L in list of P511 参见参见P418 图图15-28 Refer to P418 Fig. 15-28 螺钉联接画法螺钉联接画法 Drawing of bolt joints 45 35 常见的错误画法常见的错误画法Incorrect drawings： 允许将

40、螺纹画到底允许将螺纹画到底 Simplified representation permitted 螺钉末端应不拧到底螺钉末端应不拧到底The screw should not touch the end of the tapped hole. 螺纹终止线应螺纹终止线应 高于两零件分界高于两零件分界 Thread end line should be higher than the demarcation line 36 锥顶角度？锥顶角度？ What is the angle? 倾斜角度？倾斜角度？ How inclined? 剖面线画到何处？剖面线画到何处？ Where the secti

41、on lines extended to? 画在何处？画在何处？ The structure of the cone? 37 3. 双头螺柱联接双头螺柱联接 A stud joints 光孔光孔 Clearance hole 螺纹孔螺纹孔 Tapped hole 螺柱联接用于零件材料较厚不能制通孔的机构。螺柱联接用于零件材料较厚不能制通孔的机构。 Stud joints are used on machines which are difficult to drill through holes in . 螺母端螺母端 Nut end 旋入端旋入端 Metal end 38 双头螺柱联接画法双

42、头螺柱联接画法 Representation of stud joints bm L Ld= +0.15d+0.8d+0.3d 旋合长度旋合长度bm（即螺柱旋入（即螺柱旋入 端长度），端长度），同螺钉一样由被同螺钉一样由被 联接件的材料决定。联接件的材料决定。 As in screw joint, length of screwed bm is（i.e. the length of metal end of the stud ） determined by material of jointed part 查表查表 P507 螺柱画法参见螺柱画法参见P415图图15-20 ，螺母端螺纹长度可近

43、似为，螺母端螺纹长度可近似为2d。See P415 Fig. 15-20 for drawing of stud ，the length of nut end can be drawn as 2d. 螺柱联接画法参见螺柱联接画法参见P417 图图15-25 和和15-26 Refer to P417 Fig. 15-25 and 15-26 对齐对齐 Aligned 39 小小 结结Conclusion 1. 在螺纹的规定画法中，要抓住三条线。在螺纹的规定画法中，要抓住三条线。The key is three lines in the conventional representation of thread: 牙底用牙底用细实线细实线表示表示 (用手摸不着的柱面用手摸不着的柱面)。 The root by thin solid line (The portion that cant