Sectioning
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The document discusses different types of section views used in engineering drawings to reveal internal features of objects. It describes various section techniques including full sections, half sections, offset sections, broken-out sections, revolved sections, and removed sections. It provides examples and conventions for each type of section view, such as using a center line to separate sectioned and unsectioned parts in a half section. The document also covers topics like cutting plane lines, section lining, and bearing types.
Sectioning
- 1. MEHRAN UNIVERSITY OF ENGINEERING & TECHNOLOGY, JAMSHORO B.E MECHANICAL ENGINEERING BATCH-F16, 1ST YEAR,1ST SEMESTER ENGINEERING DRAWING & GRAPHICS
- 2. MEHRAN UNIVERSITY OF ENGINEERING & TECHNOLOGY, JAMSHORO B.E MECHANICAL ENGINEERING BATCH-F16, 1ST YEAR,1ST SEMESTER Given Finish No Internal features make a view difficult to read or dimension? Orthographic projection principle Yes Section technique Orthographic projection principle
- 3. MEHRAN UNIVERSITY OF ENGINEERING & TECHNOLOGY, JAMSHORO B.E MECHANICAL ENGINEERING BATCH-F16, 1ST YEAR,1ST SEMESTER Purpose s Clarify an internal feature. Facilitate dimensioning. Example Regular view Section view
- 4. MEHRAN UNIVERSITY OF ENGINEERING & TECHNOLOGY, JAMSHORO B.E MECHANICAL ENGINEERING BATCH-F16, 1ST YEAR,1ST SEMESTER Cutting plane Cutting plane is an imaginary plane that cuts through the object. Location and direction of a cutting plane depend on a hidden feature that is needed to be revealed. A section view is obtained by viewing the object after removed the cover up part in the direction normal to the cutting plane. Cutting plane Example Section view
- 5. MEHRAN UNIVERSITY OF ENGINEERING & TECHNOLOGY, JAMSHORO B.E MECHANICAL ENGINEERING BATCH-F16, 1ST YEAR,1ST SEMESTER Cutting plane line In an orthographic view, a cutting plane is presented as a “cutting plane line, CPL” and is drawn in either of an adjacent view of the section view. Given Direction 1 Direction 2 Direction 3 Section view CPL CPL Section view Section view
- 6. MEHRAN UNIVERSITY OF ENGINEERING & TECHNOLOGY, JAMSHORO B.E MECHANICAL ENGINEERING BATCH-F16, 1ST YEAR,1ST SEMESTER Viewing direction Cutting plane line : Line styles The cutting plane line is presented by a chain line here. Begin and end the line with a short visible line. When the line changes its direction, draw a short visible line at that corner. Draw an arrow at about the mid-length of a short visible line, the arrow head is pointed toward to this line in a viewing direction. Examples 1 2 3
- 7. MEHRAN UNIVERSITY OF ENGINEERING & TECHNOLOGY, JAMSHORO B.E MECHANICAL ENGINEERING BATCH-F16, 1ST YEAR,1ST SEMESTER Do you find something wrong in the following cutting plane lines? 3 1 Yes No Wrong! (The arrow on the right side should be pointed downward) Yes No Wrong! (The arrow head have to touch the short visible line) Yes No Wrong! (Because the cutting plane line used is not a chain line ) 2
- 8. MEHRAN UNIVERSITY OF ENGINEERING & TECHNOLOGY, JAMSHORO B.E MECHANICAL ENGINEERING BATCH-F16, 1ST YEAR,1ST SEMESTER Change the following incorrect cutting plane line style to that previously suggested. 11 22
- 9. MEHRAN UNIVERSITY OF ENGINEERING & TECHNOLOGY, JAMSHORO B.E MECHANICAL ENGINEERING BATCH-F16, 1ST YEAR,1ST SEMESTER Section lining : Purpose Section lines or cross-hatch lines are added to a section view to indicate surface that are cut by a cutting plane. Examples Section view without section lines Section view with section lines Visible surfaces and edges behind the cutting plane are drawn in a section view.
- 10. MEHRAN UNIVERSITY OF ENGINEERING & TECHNOLOGY, JAMSHORO B.E MECHANICAL ENGINEERING BATCH-F16, 1ST YEAR,1ST SEMESTER The section lines are different for each type of material. Cast iron, Malleable iron Steel Concrete Sand Wood Practically, the cast iron symbol is used most often for any materials. Section lining : Symbol Examples
- 11. MEHRAN UNIVERSITY OF ENGINEERING & TECHNOLOGY, JAMSHORO B.E MECHANICAL ENGINEERING BATCH-F16, 1ST YEAR,1ST SEMESTER The spacing between lines may vary from 1.5 mm for small sectioned areas to 3 mm for large sectioned areas. Poor practices Section lining : Too dense Too coarse Uneven spacing Uneven orientation Examples
- 12. MEHRAN UNIVERSITY OF ENGINEERING & TECHNOLOGY, JAMSHORO B.E MECHANICAL ENGINEERING BATCH-F16, 1ST YEAR,1ST SEMESTER It should not run parallel or perpendicular to contour of the view. Section lining : Poor practices Examples
- 13. MEHRAN UNIVERSITY OF ENGINEERING & TECHNOLOGY, JAMSHORO B.E MECHANICAL ENGINEERING BATCH-F16, 1ST YEAR,1ST SEMESTER Class activity Which one is a good practice in section lining? 11 22
- 14. MEHRAN UNIVERSITY OF ENGINEERING & TECHNOLOGY, JAMSHORO B.E MECHANICAL ENGINEERING BATCH-F16, 1ST YEAR,1ST SEMESTER Kind of sections 1. Full section 2. Offset section 3. Half section 4. Broken-out section 5. Revolved section (aligned section) 6. Removed section (detailed section)
- 15. MEHRAN UNIVERSITY OF ENGINEERING & TECHNOLOGY, JAMSHORO B.E MECHANICAL ENGINEERING BATCH-F16, 1ST YEAR,1ST SEMESTER Conventional practice: Hidden lines are usually omitted within the section lined area. Example Hidden lines are omitted. Hidden lines present.
- 16. MEHRAN UNIVERSITY OF ENGINEERING & TECHNOLOGY, JAMSHORO B.E MECHANICAL ENGINEERING BATCH-F16, 1ST YEAR,1ST SEMESTER Full section : Concept & example A section view is made by passing the straight cutting plane completely through the part. Example
- 17. MEHRAN UNIVERSITY OF ENGINEERING & TECHNOLOGY, JAMSHORO B.E MECHANICAL ENGINEERING BATCH-F16, 1ST YEAR,1ST SEMESTER A closer look
- 18. MEHRAN UNIVERSITY OF ENGINEERING & TECHNOLOGY, JAMSHORO B.E MECHANICAL ENGINEERING BATCH-F16, 1ST YEAR,1ST SEMESTER Offset section : Concept & example A section view is made by passing the bended cutting plane completely through the part.Example Edge views of the cutting plane are omitted
- 19. MEHRAN UNIVERSITY OF ENGINEERING & TECHNOLOGY, JAMSHORO B.E MECHANICAL ENGINEERING BATCH-F16, 1ST YEAR,1ST SEMESTER Half section : Concept & example A section view is made by passing the cutting plane halfway through an object and remove a quarter of it. Example
- 20. MEHRAN UNIVERSITY OF ENGINEERING & TECHNOLOGY, JAMSHORO B.E MECHANICAL ENGINEERING BATCH-F16, 1ST YEAR,1ST SEMESTER Half section : A center line is used for separating the sectioned half from the unsectioned half of the view. Hidden line is omitted in unsectioned half of the view.
- 21. MEHRAN UNIVERSITY OF ENGINEERING & TECHNOLOGY, JAMSHORO B.E MECHANICAL ENGINEERING BATCH-F16, 1ST YEAR,1ST SEMESTER A section view is made by passing the cutting plane normal to the viewing direction and removing the portion of an object in front of it. Broken-out section : Example The sectioned and unsectioned portions are separated by a break line. Cutting plane line is not necessary. Break line is freehand drawn as a thin continuous line. Conventional practices
- 22. MEHRAN UNIVERSITY OF ENGINEERING & TECHNOLOGY, JAMSHORO B.E MECHANICAL ENGINEERING BATCH-F16, 1ST YEAR,1ST SEMESTER Revolved section: A section view is made by revolving the cross-section view 90o about a cutting plane line and drawn on the orthographic view. Example a a b b
- 23. MEHRAN UNIVERSITY OF ENGINEERING & TECHNOLOGY, JAMSHORO B.E MECHANICAL ENGINEERING BATCH-F16, 1ST YEAR,1ST SEMESTER 1. Superimposed to orthographic view. SuperimposedBreak 2. Break from orthographic view. Revolved section : Placement of a cross-section view
- 24. MEHRAN UNIVERSITY OF ENGINEERING & TECHNOLOGY, JAMSHORO B.E MECHANICAL ENGINEERING BATCH-F16, 1ST YEAR,1ST SEMESTER Revolved section :
- 25. MEHRAN UNIVERSITY OF ENGINEERING & TECHNOLOGY, JAMSHORO B.E MECHANICAL ENGINEERING BATCH-F16, 1ST YEAR,1ST SEMESTER6. Removed section Removed section is created with the same concept as a revolved section. But, the cross-section view is shown outside the view. Removed section : Concept
- 26. MEHRAN UNIVERSITY OF ENGINEERING & TECHNOLOGY, JAMSHORO B.E MECHANICAL ENGINEERING BATCH-F16, 1ST YEAR,1ST SEMESTER Example : Revolved vs. removed sections. Revolved section Removed section Removed section : Comparison with a revolved section
- 27. MEHRAN UNIVERSITY OF ENGINEERING & TECHNOLOGY, JAMSHORO B.E MECHANICAL ENGINEERING BATCH-F16, 1ST YEAR,1ST SEMESTER Summary An engineer has several choices of section techniques to reveal an internal feature of an object. Object having a symmetry, an appropriate choice is such as full section or half section. Object having several features that do not locate in-line among each other, an offset section may be a good choice. Broken-out section is usually used when an engineer need to reveal a local detail of each feature. Revolved and removed section views are efficient when an engineer need to reveal only a cross section shape of an object.
- 28. MEHRAN UNIVERSITY OF ENGINEERING & TECHNOLOGY, JAMSHORO B.E MECHANICAL ENGINEERING BATCH-F16, 1ST YEAR,1ST SEMESTER
- 29. MEHRAN UNIVERSITY OF ENGINEERING & TECHNOLOGY, JAMSHORO B.E MECHANICAL ENGINEERING BATCH-F16, 1ST YEAR,1ST SEMESTER BEARING: Rotating shafts, which transmit motion and power, need to be supported on bearings. A bearing is a machine element which support another moving machine element (shaft). It permits a relative motion between the contact surfaces of the members, while carrying the load. Oil is used minimize the frictional resistance and wear. The portion of the shaft supported by the bearing is called journal. Types (a) Rolling contact bearings, and (b) Sliding contact bearings.
- 30. MEHRAN UNIVERSITY OF ENGINEERING & TECHNOLOGY, JAMSHORO B.E MECHANICAL ENGINEERING BATCH-F16, 1ST YEAR,1ST SEMESTER ROLLING CONTACT BEARINGS: BALL, PIN, CYLINDER ARE USED.
- 31. MEHRAN UNIVERSITY OF ENGINEERING & TECHNOLOGY, JAMSHORO B.E MECHANICAL ENGINEERING BATCH-F16, 1ST YEAR,1ST SEMESTER SLIDING CONTACT BEARINGS: 1- BUSHED BEARING: Journal or plain bearings consist of a shaft or journal which rotates freely in a supporting metal sleeve or shell. There are no rolling elements in these bearings. A bushed bearing, is a solid bearing in which a bush of brass or gun metal is provided. The outside of the bush is a driving fit in the hole of the casting whereas the inside is a running fit for the shaft.
- 32. MEHRAN UNIVERSITY OF ENGINEERING & TECHNOLOGY, JAMSHORO B.E MECHANICAL ENGINEERING BATCH-F16, 1ST YEAR,1ST SEMESTER SLIDING CONTACT BEARINGS: 1- BUSHED BEARING: When the bush gets worn out, it can be easily replaced. In small bearings, the frictional force itself holds the bush in position, but for shafts transmitting high power, grub screws are used for the prevention of rotation and sliding of the bush.
- 33. MEHRAN UNIVERSITY OF ENGINEERING & TECHNOLOGY, JAMSHORO B.E MECHANICAL ENGINEERING BATCH-F16, 1ST YEAR,1ST SEMESTER SLIDING CONTACT BEARINGS: When the bush gets worn out, it can be easily replaced. Bush material is brass, gun metal, steel etc.
- 34. MEHRAN UNIVERSITY OF ENGINEERING & TECHNOLOGY, JAMSHORO B.E MECHANICAL ENGINEERING BATCH-F16, 1ST YEAR,1ST SEMESTER Question#1. The isometric view of a Bushed Bearing is shown below. Draw the following views to scale 1:1. a. Sectional front view. b. Side view as viewed from left. c. Top view. TO SUBMIT
- 35. MEHRAN UNIVERSITY OF ENGINEERING & TECHNOLOGY, JAMSHORO B.E MECHANICAL ENGINEERING BATCH-F16, 1ST YEAR,1ST SEMESTER The isometric view of a Bushed Bearing is shown below. Draw the following views to scale 1:1. (a). Sectional front view. (b)Side view as viewed from left. (c). Top view. SOLUTION # 1. TO SUBMIT
- 36. MEHRAN UNIVERSITY OF ENGINEERING & TECHNOLOGY, JAMSHORO B.E MECHANICAL ENGINEERING BATCH-F16, 1ST YEAR,1ST SEMESTER QUESTION # 2.The isometric view of a Bushed Bearing is shown below. Draw the following views to scale 1:1. a. Sectional front view. b. Top view.
- 37. MEHRAN UNIVERSITY OF ENGINEERING & TECHNOLOGY, JAMSHORO B.E MECHANICAL ENGINEERING BATCH-F16, 1ST YEAR,1ST SEMESTER Bushed Bearing: SOLUTION # 2.
- 38. MEHRAN UNIVERSITY OF ENGINEERING & TECHNOLOGY, JAMSHORO B.E MECHANICAL ENGINEERING BATCH-F16, 1ST YEAR,1ST SEMESTER SLIDING CONTACT BEARINGS: 2- OPENED BEARING: This bearing consists of a 'U' shaped cast iron body with the similar shaped collared brass, bronze or gun metal bush. This bearing is useful for shafts rotating at slow speeds.
- 39. MEHRAN UNIVERSITY OF ENGINEERING & TECHNOLOGY, JAMSHORO B.E MECHANICAL ENGINEERING BATCH-F16, 1ST YEAR,1ST SEMESTER SLIDING CONTACT BEARINGS: 2- OPENED BEARING: The figure shows the details of an 'Open bearing'. Draw the following views to scale 1:1. a. Front view, b. Top view. c. Side view as viewed from left. TO SUBMIT
- 40. MEHRAN UNIVERSITY OF ENGINEERING & TECHNOLOGY, JAMSHORO B.E MECHANICAL ENGINEERING BATCH-F16, 1ST YEAR,1ST SEMESTER SYLLABUS • Introduction & Basics: Introduction to graphic language, Essential drawing instruments and their correct use. Line types and lettering. Basic drafting techniques and standards. Curves used in engineering. • Orthographic Projections: • Orthographic multi view projection of some simple and composite solids. • Sections: Sectioning and projection of auxiliary views. • Surface Development: Surface development of simple solids such as cylinder, cone, prism and pyramid, surface development of intersecting solids. • Isometric Projections: Isometric projection / drawings of piping. • Freehand/Sketching : Sketching and basic rules of sketching. • Detail, assembly and Working Drawings: Preparing detail, assembly and working drawings of various machine and engine parts such as, keys, cotters, foundation bolts, screws, pulleys, couplings, bearings riveted joints and nut and bolts. Fundamentals of geometric dimensioning and tolerancing. • Computer Aided Drawing: Computer aided drafting (CAD). Auto CAD Software