1、1機(jī)械圖樣的五種基本表示法 Five basic methods for mechanical part drawing： 視圖 Views 2.剖視圖 Sectional Views （剖切平面的種類 Types of cutting plane ）3. 斷面圖Cross-Sections 4. 局部放大圖Local Enlarged Views 簡(jiǎn)化畫法 Conventional drawing 介紹第三角畫法 Third-angle projection第 三 講表達(dá)機(jī)件的常用方法-IIFundamental methods for representation of mechanica

2、l parts技術(shù)制圖國(guó)家標(biāo)準(zhǔn)GB/T 4458.12002 規(guī)定全剖、半剖、局部剖2用局部視圖替換左視圖。Replace the left side view by a local sectional view.343.1 剖切平面的種類及適用條件1.單一剖切平面Single cutting plane全剖 Full section半剖 Half section局部剖 Broken-out section斜剖視 Inclined section5 兩相交的剖切平面（旋轉(zhuǎn)剖）Intersecting cutting plane (Aligned section)AAAAAAA 當(dāng)機(jī)件的內(nèi)部結(jié)構(gòu)

3、形狀用一個(gè)剖切平面剖切不能表達(dá)完全，且機(jī)件又具有回轉(zhuǎn)軸時(shí)。As the interior structure of one part which revolves about an axis cant be represented completely by one cutting plane section .方法： 用幾個(gè)相交的剖切平面將機(jī)件剖開(kāi)，先將與傾斜剖切平面接觸的結(jié)構(gòu)要素及相關(guān)部分轉(zhuǎn)正，再進(jìn)行投影。Cutting the part with two intersecting planes and rotating the aligned section view of the pa

4、rt about an axis ,then projecting it.此處無(wú)交線 No intersecting line旋轉(zhuǎn)剖視圖 aligned sectional view為避免實(shí)體化的感覺(jué)，肋板的縱向剖切不畫剖面線。To avoid the impression of solidity, a section not showing the ribs section-lined is preferred縱向剖切到的肋板的真實(shí)投影可能會(huì)給讀圖人以誤解。 A true-projection sectional view of a part, would be misleading whe

5、n the cutting plane passed longitudinally through the center of the rib.7 幾個(gè)平行的剖切平面 Parallel cutting planes （階梯剖offset section ） 當(dāng)機(jī)件上的孔槽及空腔等內(nèi)部結(jié)構(gòu)不在同一平面內(nèi)時(shí)。 Offset sections are used for complex parts that have a number of important features that cannot be sectioned using a straight cutting plane.AA AAA

6、A8 幾個(gè)平行的剖切平面 （階梯剖offset section ） 注意問(wèn)題： 兩剖切平面的轉(zhuǎn)折處不應(yīng)與圖上的輪廓線重合，在剖視圖上不應(yīng)在轉(zhuǎn)折處畫線。The change of plane that occurs when the cutting plane is bent 90 degrees is not represented with lines in the section view. 在剖視圖內(nèi)不能出現(xiàn)不完整的要素。只有當(dāng)兩個(gè)要素有公共對(duì)稱中心線或軸線時(shí)，可以此為界各畫一半。 There shouldnt be incomplete feature on the section e

7、xcept when two features have a common center-line of symmetry or axis ( Half of each feature can be drawn with the center-line as a dividing line.)AAAAAAAA AAAA階梯剖切平面Offset sectionAAAAAA階梯剖視圖 Offset sectional view11一. 重合斷面 Revolved cross-section 斷面圖置于圖形之內(nèi)。The cross section is revolved in place and c

8、oincides with the relevant vies.用細(xì)實(shí)線繪制輪廓，加剖面符號(hào)。Contour by thin solid line and filled with section lines斷面形狀對(duì)稱,省略標(biāo)注。Label is omitted to symmetrical cross-section3.2斷面圖 Cross-section (called cuts for short)表達(dá)機(jī)件斷面形狀的方法。Used to indicate the cross sectional shape of an object.斷面形狀不對(duì)稱：標(biāo)注剖切平面位置及投影方向，不注名稱。W

9、hen the cross-section is nonsymmetrical, an arrowed cutting plane symbol without name is used to label.12二. 移出斷面Removed cross-section 斷面圖置于圖形之外。The cross-section be removed to outside of the drawing.用粗實(shí)線繪制輪廓，加剖面符號(hào)。Contour by thick solid line and filled with section lines.軸上有回轉(zhuǎn)面的孔、坑：斷面封口。Close contou

10、r for revolutionary hole, groove點(diǎn)劃線應(yīng)垂直于輪廓線軸上非回轉(zhuǎn)面的孔、坑、槽：斷面開(kāi)口。Open contour for non-revolutionary hole, groove or slot.1313AAA-AB-BBB當(dāng)斷面移出置于剖切平面的延長(zhǎng)線上，如圖形不對(duì)稱，需用箭頭標(biāo)明投影方向The removed cross-section may be aligned with the cutting symbol and the letters may be omitted. 當(dāng)斷面移出不位于剖切平面的延長(zhǎng)線上，需進(jìn)行標(biāo)注； If the removed

11、 cross-section may be placed in any free space on the drawing. Like A-A. In this case, the location of the cutting plane is indicated on the relevant views by the lettered cutting symbol, the direction of the projection is indicated by the arrow. 如果圖形對(duì)稱，可省略投影方向箭頭。 When the cut is symmetric, the arro

12、ws may be omitted.如果圖形對(duì)稱，則無(wú)需標(biāo)注； When the cut is symmetric, it may be placed on a cutting line extended and no identification is required.14A-A152:12:1 用細(xì)實(shí)線圈出被放大部位。有多處放大，需用羅馬數(shù)字標(biāo)明， 并在局部放大圖上方標(biāo)明相應(yīng)的羅馬數(shù)字及所用比例（相對(duì)實(shí)物） 局部放大圖可畫成視圖、剖視圖或斷面圖，視需要而定。3.3 局部放大圖Local enlarged views當(dāng)機(jī)件上部分結(jié)構(gòu)的圖形過(guò)小時(shí)，可以采用局部放大的比例畫出。163.3 規(guī)定

13、和簡(jiǎn)化畫法Conventional Representations一、肋板的畫法Ribs 對(duì)于機(jī)件的肋板，如按縱向剖切，肋板不畫剖面符號(hào)，而用粗實(shí)線將它與其鄰接部分分開(kāi)。橫向剖切肋板則畫出剖面線。Rib should be separated by thick solid lines but not section-lined if the cutting plane cuts along the center plane of the rib ,while section-lined if the cutting plane passes crosswise through the plat

14、e.A AAABBBBBB正確Correct錯(cuò)誤Incorrect17二、均勻分布的肋板及孔的畫法 Ribs and holes distributed uniformly肋不對(duì)稱畫成對(duì)稱 Ribs appear as symmetrical孔未剖到畫成剖到Hole appear as sectionedBBBB 若干直徑相同且成規(guī)律分布的孔，可以僅畫出一個(gè)或幾個(gè)，其余只需用細(xì)點(diǎn)畫線表示其中心位置。Holes with same size positioned regularly can be represented by one complete sample and the rest by

15、 center lines on their positionsAAAA18實(shí)長(zhǎng)True length實(shí)長(zhǎng)True length三、斷開(kāi)的畫法 Breaks 軸、桿類較長(zhǎng)的機(jī)件，當(dāng)沿長(zhǎng)度方向形狀相同或按一定規(guī)律變化時(shí)，允許斷開(kāi)畫出。The conventional representation of breaks is used to shorten a relatively ling piece so that it can be shown to a larger scale .標(biāo)注尺寸時(shí)，仍注實(shí)長(zhǎng)。Dimension shows the true length.拉桿軸套斷開(kāi)畫法階梯軸斷開(kāi)

16、畫法19四、對(duì)稱圖形的畫法Views of symmetrical parts 在不致引起誤解時(shí)，可只畫一半或四分之一。并在對(duì)稱中心線的兩端畫出兩條與其垂直的平行細(xì)實(shí)線。Symmetrical parts may be drawn as one half or a quarter of the whole , provided that no misunderstanding.對(duì)稱省略圖標(biāo)記（symbol for symmetrical omitting）二分之一表示整體四分之一表示整體20五、機(jī)件上小平面的畫法Small plane on the part 當(dāng)回轉(zhuǎn)體機(jī)件上的平面在圖形中不能充

17、分表達(dá)時(shí)，可用相交的兩條細(xì)實(shí)線表示。Small plane indicated by two diagonally drawn thin solid lines21小 結(jié) 本章所介紹的各種視圖、剖視圖的畫法及標(biāo)注方法，均系國(guó)標(biāo)規(guī)定，必須很好掌握，才能畫出合格的工程圖紙。 簡(jiǎn)化及規(guī)定畫法只介紹了常用的幾種，這部分內(nèi)容較多，需要時(shí)可查閱有關(guān)標(biāo)準(zhǔn)。22作業(yè)： P63 5 按規(guī)定補(bǔ)全主、左視圖（注意剖面線的間隔和方向，各視圖保持一致）6 三視圖（可取適當(dāng)剖視，不注尺寸）23側(cè)視圖（右）Right Side主視圖Front俯視圖 Top第一角投影First-Angle Projection水平投影面 Horizontal Plane正投影面 Front Plane側(cè)投影面Right Side Plane附錄：第三角投影簡(jiǎn)介Third-Angle Projection24俯視圖主視圖側(cè)視圖（右）展開(kāi)折線水平投影面正投影面?zhèn)韧队懊娴谌峭队?Third-Angle projection25第三分角的三視圖 Three Primary Views 主俯右26正面觀察-主視圖頂面觀察-俯視圖右面觀察-右視圖第三分角的六視圖 Six Primary Views by third-angle 28六個(gè)投影面的展開(kāi) Open the