Materials and Industrial Manufacturing Processes for an Automotive Clutch Pedal

Im a second year student at Queens University Belfast and this is an assignment given in the Polymer Processing for Design module which is part of my course. So since the module is based on polymers then the assignment must include polymers. The point is to show us how polymers can replace existing materials traditionally being used, sometimes resulting is lighter, stronger and cheaper parts.

Hi paddy...

Well, you have come to a top-notch site to help you with your design project. You should be able to get some good input over the next day or so and I hope that meets your assignment deadline.

I dare say you should include this collaboration with the CR4 community as part of your discourse since reaching out to others who have more knowledge and experience than you for a particular assignment is one of the hallmarks of a good engineer. Yes, the ultimate choices are yours and it is up to you whether the project is a success or failure but you should, at all times, draw on the expertise of others. So, in my book, you have already made a good decision.

Can you provide more information about the intent of the design (is it just the pedal or the entire linkage to the transmission?), the concepts that you are considering, what components need to be plastic, etc. What are the boundary constraints?

If the clutch need to be made entirely of a polymer, you will want something that is strong and durable, meaning that it can handle a relatively high tensile load, that will not fracture when applied with an excessive load, that can withstand a wide range of temperatures, etc. My first thought is a fiber reinforced molding grade of a nylon, ABS or similar thermoplastic materials. There are some very expensive thermoplastics (PEI, etc., but not sure you need to consider those for your application). And, you could consider a thermosetting material (like an epoxy) that can be molded with continuous fibers for great strength and durability. Cost is a factor, again. But, if it is for an automotive applications where the product has to work for 10 years and failure of a clutch pedal could lead to a major liability, it might be worth your while to go with the latter option I have outlined.

Also, if you are designing the entire assembly and need a cable, there are very high strength polymer cables such as aramids, PBI and others that you should consider. Be careful about your choices here as abrasion is critical and some materials will likely creep (or stretch) excessively over time.

Let's keep moving on this one, everybody!!!

I have never seen a clutch petal made from a polymer. All that I have seen were of steel. The clutch petal is a lever doing work. You have to know how much work it will need to do. So that you can choose a polymer that can with stand the forces applied to it as a lever.

ceramics are used also

Neither have I but I take it the point is to get us to understand that it could be possible to use other materials other than metals and alloys. Yes choosing a polymer to withstand the forces applied is what I need to find but the assignmnet is only to be three pages so I have to be careful about just how much detail I go into on any one point. I would say thais has the potential to be a very long assignment but that is one restraint put on to the class.

Concentrate on learning about the propeties of polymers/plastics first.

Then sell the idea that they are easier to work with and less costly.

Follow with the technology available to handle this material.

Conclude with benefits of using this material and how it contributes to economy, waste handling, recycling, employment, markets...

Hope this helps!

Start by more clearly describing the assignment.

Are you merely to design the clutch pedal?

Or is it to be the whole flippin clutch pedal likage etc mechanism?

Pedal itself will be a piece of cake.

Also, does it have to be pure mechanical, which means lots of forces, or can it be a means of enacting an electircal/electronic drive by wire kind of clutch activation?

Investing time in describing the problem up front always pays off, especially when trying to work with a far flung committee.

milo

First off I would like to thank everyone who has given feedback so far. I am sorry I did not explain everything in more detail. So below I will type out part of the assignment as given to me.

"Give reason arguments for the selection of materials and industrial manufacturing processes for the following parts: a) an autmotive clutch pedal b) a wind turbine blade.

In each case, full justification for the chosen material is required, including due consideration of the nature of the applied stress experienced during service; the effects (if any) of time of loading on the mechanical performace; the implications of temperature changes experienced; exposure to specific environmental conditions which might adversely affect the properties of the material. You should highlight any product design implications which might influence the performance of the part in service.

Material choice should also be discussed in terms of the preferred manufacturing method, in turn dependent on the number of parts to be manufactured and cost considerations. In this regard state any assumptions made when carrting out this analysis."

I hope this clears things up as to what it is im looking but yes, as far as I understand it is only the clutch pedal and nothing else.