lecture 09 sections [part-2]

7/31/2019 Lecture 09 Sections [Part-2]

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Faculty of Mechanical Engineering

Ghulam Ishaq Khan Institute of Engineering Sciences & Technology

ME-102 Engineering Graphics

Lecture #: 08

Sections [Part - 2]

Lecture By: Muftooh Ur Rehman Siddiqi

Research Associate

Office # G-17 - FME

Email: [email protected]


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Muftooh Ur Rehman Siddiqi, RA-FME, GIK Institute Page 2 of 20

Sectional View Types

Following are the different types of sections

Full Section (Lecture-8)

Half Section

Broken-out Section

Revolved Section

Removed Section (Detailed and Aligned)

Offset Section

Assembly Section (self study)

Auxiliary Section (self study)

Practice


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Full Section

A full section view is made by passing the imaginary cutting planecompletely through an object.


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Half Section

Half sections are created by passing an imaginary cutting plane onlyhalfway through an object.

Cutting plane line bend around 90

Half sections views are used most often on parts thatare symmetrical, such as cylinders.


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Broken-Out Section A broken-out section is used when only a portion of the object needs to be

sectioned.

They are some time used instead of half section to save time. A break line is drawn freehand.

No CP line is drawn.



Revolved Section

A revolved section is made by revolving the cross-section view 90degrees about an axis of revolution and superimposing the section

view on the orthographic view.

When the revolved view is superimposed on the part, the originallines of the part behind the section are deleted.

The cross-section is drawn true shape and size. The axis of revolution is shown on the revolved view as a

centerline.

Revolved sections are useful for describing a cross-section w/o

having to draw another view.



Revolved Section (Illustration)



Removed Section Area Section

Removed sections are used to show the contours of complicatedshapes, such as wings and fuselage of an airplane, blades for jet

engines or power plant turbines etc. They are often used when there is not much room for revolved sections.

The removed section view is then labeled, such as SECTION A-A



Removed Section (Contd)

Multiple removed section views of a connecting rod identified withlabels



Detail View

Removed section can also be drawn to a larger scale for betterrepresentation of the details of the cross-section and for

dimensioning.

The scale used for the removed section view is labeled beneaththe view.


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Aligning Removed Section View

Sometimes removed sections are placed on center lines adjacent tothe axis of revolution.


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Offset Section

Offset sectional views are used in cases where the sections to beshown do not lie in a straight line.

The CP is bent (more than once), to show a number of sectionalviews as one view.

The offset section are used for complicated parts that cannot be

sectioned by a single straight CP line.


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Offset Section


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Aligned Section

Aligned sections are special types of orthographic drawings usedto revolve or align special features of parts, to clarify them or make

them easier to represent in section.

The principles of orthographic projection are violated in order tomore clearly represent the features of the object.


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Aligned Section (Contd)


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Self study

Conventional breaks

Assembly section

Auxiliary section

Quiz next week.

Lecture 8, 9 and lab included.


"Muslims who possess better morals are the most perfect in faith ." ( Mishkat)


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Thank you

S


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Assembly Section

Assembly sections are typically orthographic, pictorial, full or halfsection views of parts as assembled.

Leonardo da Vinci was one of the first to create assembly section,

using them to illustrate pictorially the complex machine designs ashe developed.

Standard parts not sectioned

A bl S i (E l )


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Assembly Section (Examples)

Injection mold assembly Hatching pattern differentfor different parts

A ili S ti


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Auxiliary Section

Auxiliary section can be a full or partial section.

They follow the same convention as other types of sections.

C ti l B k


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Conventional Breaks

Conventional breaks are used toshorten elongated part.

This allows to draw a part at largerscale.

lecture 09 sections [part-2]

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