1. Assembly drawings
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B406

2. Content Working drawings Assembly drawings Examples 2019.07.03.
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3. Drawing quality assurance
Requirements of engineering drawings:
Be complete, clear and accurate
Conform to standards
Ensure proper operation
Responsibility:
Drafter
Checker
Specialist assigned to review the drawing
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4. Working drawings Working drawing Assembly drawing Detail drawing
The term drawing refers to the description of details, assemblies, installations or other types of graphical representations
A working drawing is a drawing that supplies information and instructions for the manufacture or construction of machines and structures
Working drawing
Detail drawing
Assembly drawing
Provides the necessary information for the manufacture of parts
Supply necessary information for assembly of parts
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5. Detail drawing requirement
Shape description: pictorial, ortographic views, sectional views, auxiliary views, detailed views
Size description: dimensions, tolerances
Specifications: general notes, material, heat treatment, surface finish, general tolerances, number required
Additional drawing informations: drawing number, scale, method of projection, date, name of part, drafter’s name
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6. Example of detail drawing
Views
Dimensions
Tolerances
Surface finish

7. Assembly drawings
All machines and mechanisms are composed of numerous parts
A drawing showing the product in its completed state is called an assembly drawing
Assembly drawings vary greatly in the amount and type of information given, depending on the nature of the machine or mechanism depicted
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8. Assembly drawings Primary functions:
Show the product in its completed shape
Indicate the relationship of its various components
Designate these components by a part or detail number
Other information: overall dimensions, capacity dimensions, relationship dimensions between parts, operating instructions, data on design characteristics
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9. Types of assembly drawings
Design assembly drawing
Installation Assembly drawing
Assembly drawings for catalogs
Item list (Bill of materials – BOM)
Exploded assembly drawings
Detail assembly drawings
Subassembly drawings
ábra
Source: C. Jensen, J. D. Helsel, D. R. Short: Engineering Drawing&Design
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10. Design assembly drawings
When a machine is designed an assembly drawing or a design layout is first drawn to clearly visualize the performance, shape and clearances of various parts
From this assembly drawing the detail drawings are made and each part is given a part number
The part number is attached to the corresponding part with a leader
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11. Item list (BOM)
Itemized list of all the components shown on an assembly drawing or detail drawing
Often an item list is placed on a separate sheet for ease of handling and duplicating
The item list is used by the purchasing department to order the necessary material for the design – it shows the raw material size of the part
Standard components (bolts, nuts, bearings), which are purchased rather than fabricated should have a part number. Information in the descriptive column should be suifficient for purchasing
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12. Subassembly drawings
Many completely assembled items are assembled with many preassembled components as well as individual parts
These preassembled units are referred to as subassemblies (e.g. transmission for a vehicle)
Subassemblies are designed to simplify final assembly and to permit the item to be either assembled in a more suitable area or purchased from an outside source
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13. Assembly drawing example (bearing shaft with gear- CAD)
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14. Assembly drawing example (bearing shaft with gear)
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15. Assembly drawing example (clutch)

16. Assembly drawing example (clutch)

17. Assembly drawing example (clutch)

18. Detail drawing of a clutch plate
Views
Dimensions
Tolerances
Surface finish

19. Summary
Assembly drawings
Next week: geometric tolerance

20. Thank You for Your attention!