Technological Design Section Views 1 342021 Sectional Views

Technological Design Section Views 1 3/4/2021

Sectional Views l 2 Visualize and imaginary cutting plane through an object 3/4/2021

Section Views Sectional Views are used to: l reveal interior features of an object that are not l easily represented using hidden lines l improve the visualization of designs l clarify multi-view drawings l facilitate the dimensioning of complex features l communicate material type. 3 3/4/2021

Cutting Plane Lines l l l 10 used to indicate where the imaginary cutting takes place. use extra thick lines terminated by arrow heads showing the viewing direction cutting plane lines take precedence over centre lines identifying letters are placed near arrowheads sub-title (Section A-A) indicates that sectional view is taken along cutting plane line A-A 3/4/2021

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Section Lines l l l l l 12 indicate the solid areas of a part that are imagined cut through indicate the type of material from which the part is made general-purpose section lining recommended for most drawings thin continuous lines drawn at 45 degrees. the spacing of the hatch lines should be consistent distance between lines…. . from 1 to 3 mm depending on dwg size dimensions should not be placed in sectioned areas on adjacent parts, the section lines should be drawn in opposite direction for additional adjacent parts, any suitable angle may be used to make each part stand out separately. shafts, bolts, pins, keyways, etc. should not be sectioned 3/4/2021

Types of Section Views Full Section l imaginary cutting plane fully through an object and half of it being removed l placed in the same position that an unsectioned view would normally occupy l i. e. , a front section view would replace the traditional front view 14 3/4/2021

Types of Section Views Half Section l passing an imaginary cutting plane halfway through an object and one quarter of it is removed. l Hidden lines are omitted on both halves of the section view. l External features of the part are drawn on the unsectioned half of the view. l A center line, not an object line, is used to separate the sectioned half from the unsectioned half of the view. l Half section views are most often used on parts that are symmetrical, such as cylinders. 16 3/4/2021

Types of Section Views 18 Broken-out Section l used to show interior features of a part by breaking away some of the object. l used instead of a half or full section view to save time. l A break line separates the sectioned from unsectioned half of the view. l A break line is drawn free-hand to represent the jagged edge of the break. l No cutting plane line is drawn with a broken-out section view. 3/4/2021

Types of Section Views Removed Section l l l 20 used to show the contours of complicated shapes such as wing and fuselage, blades for jet engines. passing an imaginary cutting plane perpendicular to a part then revolving the cross section 90 degrees. a removed section should be on the same sheet as the part it represents, and it should be clearly labeled. 3/4/2021

Types of Section Views Offset Sections l has its cutting plane bent at 90 degree angles to pass through important features. l Offset sections are used for complex parts that have a number of important features that cannot be sectioned using a straight cutting plane. l The cutting plane is bent at 90 degrees to pass through the hole, then bent 90 degrees again to pass through the slot. 22 3/4/2021