ENG 661 Computer Aided Engineering (Product Realisation)
TB1 – Coursework 1 (CAD) – Valve Assembly (this CW counts 50% of the module)
Learning Outcomes:
 Apply 3D CAD modelling in engineering design and appraise the ways in which CAD/CAM/CAE
integrated computer software packages can be employed to aid the design to manufacture process.
 Use an integrated 3D CAD/CAM/CAE software package in an interactive and integrative way for the
effective solution of real engineering problems.
Student Input:
Select the diameter of your valve design from Table 1. The valve diameter corresponds to the last digit of the
student ID number. A typical student should be able to complete this piece of work in 100 hours.
Submission:
All Creo files/models, technical drawings (PDFs), and the Report file zipped into a single file to be submitted
to Moodle before the date/time specified on the front page.
Late Submission:
Submission and assessment will be in accordance to Academic Regulations, University of Portsmouth,
Academic Registry.
Design brief – Air management valve assembly redesign using 3D CAD software and metric standards.
Conduct a design study on an air management valve assembly for IC petrol engine. The valve shown in the
sketches below is currently manufactured in imperial modules.
Select the diameter D mm of your variant (Table 1 below) and redesign the valve. Develop a better mechanical
design following “design for manufacture and assembly” principles using 3d CAD software (Creo) and metric
standards. Produce assembly and part technical drawings from the 3d CAD models (BS8888 and 3
rd angle
orthographic projection).
The valve assembly should contain all parts in good proportions as shown in the figure below.
The engine assembly should not have interference or unnecessary gaps between parts.
All parts should maintain their integrity as 3d models when a significant (top level) dimension for example
diameter, length, height, etc. is modified by 10%-20%.
Constraints: valve diameter and maximum pressures according to your variant (see Table 1), temperature up
to 150ºC temperature, resist corrosive gases.
Required tasks: (Write your report/logbook using these headings)
1. Create the assembly concept according to your variant (Table 1). Consider the current valve design
shown in the drawings below, the modifications that you will implement, and the best mechanical
design practices. Develop 3d CAD models of the main components using preferred sizes/dimensions
(mm).
(up to 25 marks)
2. Create the initial assembly with the main components. Create and assemble the standard parts (BS
standards) – bolts, screws, washers, etc. required for a sound mechanical design.
(up to 10 marks)
3. Integrate additional standard machine elements such as key, seals, O-rings, bearings (or bushes),
circlips, splints, etc. where appropriate in your design. The valve plate should close at a small angleto
the horizontal plane. Check for interference or clearances and modify the parts if necessary.
Milestone 1 – Assembly complete.
(up to 20 marks)
4. Add draft angles and rounds on cast parts (design for casting), rounds and chamfers on other parts
where appropriate.
(up to 5 marks)
5. Select/apply appropriate material for all parts according to their function. Calculate the amount of
material needed (volume and mass) for each part for 1 and for 10,000 valves/year production (in kg).
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(up to 5 marks)
6. Valve strength analysis. Analyse the valve body strength. Produce FEA strength analysis using Creo
Structure. Optimise the weight and calculate the final safety factor. Modify the design if necessary.
(up to 15 marks)
7. Produce at least 2 x A3 valve assembly drawings (BS8888). Use the A3 format setup file for the drawing
frame and title block. One drawing should contain the orthographic views and cross-sections of the
valve assembly with important dimensions, appropriate fits, notes. The second drawing should be an
exploded view with balloons and BOM table.
(up to 5 marks)
8. Produce complete A3 size technical drawings of Valve Body (housing) to BS 8888. Place orthographic
views, sections, and detailed views. Create all necessary annotations such as: dimensions,
dimensional and geometric tolerances, surface finish requirements, technical notes, title block with
information. Milestone 2 – Print all drawings to PDFs files.
(up to 5 marks)
9. Finalise your report (max 2000 words, 10-15 pages) following the above task list. In conclusion
critically analyse the use of integrated 3D CAD software in product design and realisation.
(up to 10 marks)
Milestone 3 – Zipp all Creo files/models from the working directory and the Report and upload to
Moodle as specified on the front page.
Table 1 Variants of the Course work
Last digit of
Student ID Number 0 1 2 3 4 5 6 7 8 9
Valve diameter,
mm
70 65 60 55 50 45 40 35 30 75
Maximum
Operational Pressure,
MPa
2.5 2.4 2.3 2.2 1.6 1.5 1.4 1.0 0.8 3.0
All lecture Notes, Tutorials, CW description
Moodle (ENG661)
E-Learning Tutorials (PTC E-Learning – Login and password required):
https://precisionlms.ptc.com/app/pages/Login?0
Recommended Courses from PTC E-learning database:
• Introduction to Creo Parametric 4.0 – Fundamentals
• Introduction to Creo Parametric 4.0 – Productivity Tools (how to do assembly, drawings, etc.)
• Advanced Modelling Using Creo 4.0
Recommended reading
Tickoo, S. (2017). Creo Parametric 4.0 for Designers. Schererville: CADCIM.
Simmons, C., Phelps, N., Maguire, D. (2012), Manual of Engineering Drawing. (4th ed.), Oxford: ButterworthHeinemann.
BSI-Online Web page (2018). Retrieved from http://www.bsigroup.com/en/
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Below are copies of the original specifications and drawings.
Note: These drawings are for guidance only. Do not use directly these dimensions.