Bike pump

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Revision as of 00:33, 24 September 2012 (view source) Patrickh@andrew.cmu.edu (Talk | contribs) (→Bill of Materials) ← Older edit		Revision as of 00:48, 24 September 2012 (view source) Patrickh@andrew.cmu.edu (Talk | contribs) (→Product Mechanical Function) Newer edit →
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	==Product Mechanical Function==		==Product Mechanical Function==
-	We will include some pretty diagrams and information about the mechanical function of our part.
		+	===User Input===
		+	The user connects the bike pump to the bike tire using the nozzle and locking mechanism. This creates a seal between the pump (from the air flow valve) and the bike tire, allowing for air to be pushed into the tire without losing some to the external environment. Once this seal is created, the pressure gauge shows the current air pressure in the tire and hose (up to the air flow valve). If this pressure is not the desired air pressure, the user lifts up the handle of the pump, filling the chamber with air, and then depresses the handle compressing the air. Once fully depressed, the user will again evaluate the current tire pressure and determine if it is still undesirable. Once the air pressure in the tire is sufficient, the user unlocks the nozzle and removes it from the tire, which contains its own sealing mechanism as to not lose air.
		+
		+	===Airflow===
		+	When the user connects the bike pump to the bike tire, air flows through the hose to the pressure gauge and stops at the air flow valve at the base of the main chamber (which works using a compression spring). When the user pulls up the handle, air is drawn in from the top of the chamber where there is no sealing device and flows past the piston head, which has a rubber o-ring that acts somewhat like a valve due to part geometry allowing air to flow past it on an upstroke but creating a seal on the downstroke, and stops at the air flow valve. Once the chamber is filled with air, the user depresses the handle, compressing the air in the chamber. Once the air pressure in the chamber is greater than the force from the spring holding the air flow valve in place the spring depresses, allowing air to flow from the chamber into the bike tire. When the handle is fully depressed and there is no more air in the chamber, the spring re-extends, sealing the air in the tire and hose allowing the user to draw more air into the chamber by pulling up the handle again and repeating the process. When the user unlocks the nozzle and removes it from the tire, the air left in the hose is lost to the environment and the tire creates it's own seal to keep air in.
	==Assembly==		==Assembly==

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Revision as of 00:48, 24 September 2012

Contents 1 Executive Summary 2 Product Stakeholders 3 Product Use Study 4 Product Mechanical Function 4.1 User Input 4.2 Airflow 5 Assembly 5.1 Sub-Assembly 5.2 Bill of Materials 6 Design for Manufacture and Assembly (DFMA) 6.1 Manufacturing 6.2 Assembly 7 Failure Modes & Effects Analysis (FMEA) 8 Design for Environment (DFE) 8.1 Production 8.2 Use 9 Group Dynamic 10 References

Executive Summary

This will be a brief executive summary that describes the key findings and recommendations.

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Product Stakeholders

We have identified possible needs and wants for all possible stakeholders. The identified needs are those needs that are essential in order to encourage the stakeholder to use it. The identified wants are additional features that may benefit the stakeholder, however, they are not vital to the use of the product. For the purpose of this study, the consumer is the person pumping up the bike tire, not necessarily the bike owner.

Stakeholder Needs and Wants
Stakeholder	Needs	Wants
Consumer	Product should not require much force or time during pumping process Mechanical advantage and efficiency during the pumping process Intuitive	Balances strong performance and minimal cost Lightweight and space efficient Ergonomic Durability
Retailer	Cheap & durable materials Efficient storage	Aesthetically appealing Standardization
Manufacturer	Cheap & easily processed materials Mass production Easy assembly	Volume-efficient materials
Shipping & Transportation	Lightweight Durability	Space-efficient packaging

Product Use Study

This is where we will document in detail how the product is used, step by step, and summarize findings from our user studies with photo documentation.

Product Mechanical Function

User Input

The user connects the bike pump to the bike tire using the nozzle and locking mechanism. This creates a seal between the pump (from the air flow valve) and the bike tire, allowing for air to be pushed into the tire without losing some to the external environment. Once this seal is created, the pressure gauge shows the current air pressure in the tire and hose (up to the air flow valve). If this pressure is not the desired air pressure, the user lifts up the handle of the pump, filling the chamber with air, and then depresses the handle compressing the air. Once fully depressed, the user will again evaluate the current tire pressure and determine if it is still undesirable. Once the air pressure in the tire is sufficient, the user unlocks the nozzle and removes it from the tire, which contains its own sealing mechanism as to not lose air.

Airflow

When the user connects the bike pump to the bike tire, air flows through the hose to the pressure gauge and stops at the air flow valve at the base of the main chamber (which works using a compression spring). When the user pulls up the handle, air is drawn in from the top of the chamber where there is no sealing device and flows past the piston head, which has a rubber o-ring that acts somewhat like a valve due to part geometry allowing air to flow past it on an upstroke but creating a seal on the downstroke, and stops at the air flow valve. Once the chamber is filled with air, the user depresses the handle, compressing the air in the chamber. Once the air pressure in the chamber is greater than the force from the spring holding the air flow valve in place the spring depresses, allowing air to flow from the chamber into the bike tire. When the handle is fully depressed and there is no more air in the chamber, the spring re-extends, sealing the air in the tire and hose allowing the user to draw more air into the chamber by pulling up the handle again and repeating the process. When the user unlocks the nozzle and removes it from the tire, the air left in the hose is lost to the environment and the tire creates it's own seal to keep air in.

Assembly

This is where we will have information/photo about the major assembly.

An exploded view of the floor bike pump will be inseted here... with all components labeled.

Sub-Assembly

We may need to include detailed sub-assembly photos and information here.

This is where we will insert exploded views of each internal sub-assembly with labeled components and a brief summary of each sub-assembly function.

Bill of Materials

The following is a bill of materials from the bike pump dissection. The parts can be sorted based on part number, quantity, weight or material by clicking on the appropriate tab at the top of the table.

Part Number	Name	QTY	Weight (g)	Function	Material	Manufacturing Process	Image
1	Screw	5	4	Holds base support (#8) in place to metal base (#31)	Steel	***	Screw
2	Nut	5	1	Attaches screws (#1) to metal base (#31)	Steel	***	Nut
3	Rubber readout cover	1	30	Holds plastic readout cover (#4) in place above pressure gauge mechanics (#23)	Rubber	Injection Molding	Rubber readout cover
4	Plastic readout cover	1	12	Provides clear screen and protection to number dial readout (#10)	Plastic	Injection Molding	Plastic readout cover
5	Metal connection valve tip	1	5	Holds rubber connection valve tip (#6) in place	Aluminum	Press Molding + Threading	Metal connection valve tip
6	Rubber connection valve tip	1	2	Creates seal onto bike tube valve	Rubber	Injection Molding	Rubber connection valve tip
7	Air hose holder (double)	1	12	Holds air hose (#32) to main tube (#30) during storage	Plastic	Injection Molding	Air hose holder (double)
8	Plastic base support	1	10	Reduces cantilever stresses on outer arm tube	Plastic	Injection Molding	Plastic base support
9	#7 O-Ring	2	< 1	Provides necessary friction to hold the double air hose holder (#7) onto outer arm tube (#30) and allow for vertical movement along axis of tube	Rubber	***	#7 O-Ring
10	Readout number dial	1	3	Provides a quantified tire pressure readout	Aluminum	Sheet Stamped	Readout number dial
11	Readout needle	1	< 1	Displays the quantified tire pressure on (#10	Aluminum	Press Stamped	Readout needle
12	#13 O-Ring	2	< 1	Provides seal on bike tube inside the pump stabalizer (#13)	Rubber	Injection Molding	#13 Rubber seal
13	Pump stabalizer	1	13	Allows metal rod (#19) to move within the main tube (#30)	Plastic	Injection Molding	Pump stabalizer
14	Piston head	1	8	Acts as a pump to draw in air within the main tube (#30) and then compress the air	Plastic	Injection Molding	Piston head
15	Tube connector	2	4	Connects hose (#32) to nozzle (#***) and to the metal base (#31)	Plastic	Injection Molding	Tube connector
16	Air hose holder (single)	1	2	Holds air hose (#32) to main tube (#30) during storage	Plastic	Injection Molding	Air hose holder (single)
17	Handle bar	1	127	Allows user to apply downward force to draw and compress air in the main tube (#30)	Plastic	Injection Molding	Handle bar
18	End cap	2	6	Provides a covering to the ends of the handle bar	Plastic	Injection Molding	End cap
19	Metal rod	1	174	Connects piston head (#14) to the handle bar (#17)	Steel	Extrusion + Crimp	Metal rod
20	Stopper	1	< 1	Blocks airflow during upstroke	Rubber	Injection Molding	Stopper
21	Spring	1	< 1	Pushes up stopper	Steel	Coiled Wire	Spring
22	O-Ring	1	< 1	Creates seal	Rubber	Injection Molding	O-Ring
23	Pressure gauge mechanics	1	50	Converts air pressure to angular displacement	Copper	***	Pressure gauge mechanics
24	Small screw	2	< 1	Fixes pressure gauge housing	Steel	***	Small screw
25	Air flow director	1	49	Guides air flow from piston to hose	Plastic	Injection Molding + Threading	Air flow director
26	#27 O-Ring	1	< 1	Provides a seal to the hose-to-nozzle connector (#27)	Rubber	Injection Molding	#27 O-Ring
27	Hose-to-nozzle connector	1	< 1	Allows air to flow from hose to nozzle	Plastic	Injection molding	Hose-to-nozzle connector
28	Seal between #25 & #29	1	< 1	Provides a seal between the air flow director (#25) and the base-to-hose (#29)	Rubber	Injection Molding	Seal between #25 & #29
29	Base-to-hose connector	1	7	Provides a connection between hose (#32) and air flow director (#25)	Plastic	Injection Molding	Base-to-hose connector
30	Main tube	1	238	House piston	Steel	Injection Molding + Threading	Main tube
31	Metal base	1	540	Provides counter force from upstroke	Steel	Molded + Drill Pressed	Metal base
32	Hose	1	83	Encloses from base to nozzle	Rubber	Extrusion	Hose
33	Weighted handle insert	1	***	***	Aluminum	Lathed + ???	Weighted handle insert
34	Valve connection housing	1	***	Gripping surface	Plastic	Injection Molding	Valve connection housing
35	Valve channel	1	***	Channels air through handle	Plastic	Injection Molding	Valve channel
36	Tire interface valve	1	***	Puts air in tire	Steel	***	Tire interface valve
37	Readout housing	1	***	Protection of pressure gauge	Steel	Press Molded	Readout housing
38	Piston chamber end cap	1	***	Fixes main tube to base	Steel	Molded? + ***	Piston chamber end cap

Design for Manufacture and Assembly (DFMA)

DFMA is a combination of two practices, Design for Manufacture (DFM) and Design for Assembly (DFA). DFM is the method of designing part so that they're manufacturing processes are simplest, and DFA is the method of designing parts that will lead to a simple assembly process at the plant or by the user.

Manufacturing

The competitor product we analyzed displayed numerous positive manufacturing features that would minimize cost and complexity. The overall design is surprisingly simple, a result of combining features into single parts where possible, using only a few different materials, and minimizing the overall part count. From a manufacturing standpoint, all components are very successfully produced, but the part that could use the most improvement is the piston chamber end cap (#38) for it involved several manufacturing processes and an additional painting process not seen on any other parts.

Below are some of the DFM Guidelines and the observations we made of how our competitor designed their product with those guidelines in mind and some areas we believe they could improve.

Design for Manufacturing Features and Improvements
Design Objective	Strengths	Areas of Improvement
Minimize Part Count	Few fasteners, mostly everything screws and locks together Many multifunctional components leading to less parts overall
Standardize Design Features	All screws in the system are identical	Since there are few fasteners, most parts are custom-made for this product
Keep Designs Simple	Piston shows a clever design to allow air into the pump on upstroke while eliminating lost air on downstroke, while still remaining very simple	Pressure gauge is very complex, needs fine adjustment and much protection
Multifunctional Parts	Many parts serve a specific purpose while also screwing into the next assembling acting as both a functional piece and connector
Ease of fabrication	Mostly composed of some type of plastic and steel	The plastic parts are for the most part unique and would each need their own mold
Avoid Tight Tolerances	Uses flexible rubber o-rings to allow for larger tolerances while remaining airtight
Minimize Secondary & Finishing Operations		Since parts are multifunctional, most would require at least would need a secondary threading operation

Assembly

Assembly of the competitor's product is not the consumer's responsibility and occurs prior to the retail stages in the supply chain. The product requires tools and fasteners only where the piston chamber attaches to the base, and nearly all of the remaining interfaces are threaded. While minimizing toolage, this raises many challenges with orientation and radial symmetry where the assembly process could be made clearer. The variety of O-rings, springs, and cylinder diameters is another weakness that has room for improvement.

Due to the assembly process being deliberately separated from the consumer, ease of assembly is not a high priority and leaves room for redesign towards simplicity.

Design for Assembly Features and Improvements
Design Objective	Strengths	Areas of Improvement
Minimize Part Count		There’s the metal piece in the handle we can’t account for Air flow pathway has several components
Minimize Assembly Surfaces		Baseplate has multiple interfaces, axes Piston has multiple planes and axes
Use Sub-assemblies	Pressure Gauge is a discrete system Air compression mechanics are limited to main tube Nozzle is a discrete system	Functional testing requires end-to-end assembly
Mistake-Proof	Asymmetric Handlebar	Many radially symmetric parts
Minimize Fasteners	Most of the assembly is screwed together	Tools and fasteners required for fixing main tube to base
Minimize Handling	Hose attachments have conical guides	Interfaces have many different axes and planes
Minimize Assembly Direction		Two distinct possible assembly directions (Nozzle or Handle)
Provide Unobstructed Access		Base plate obscures airflow components Nozzle has multiple hidden components Pressure gauge mechanics are hard to access
Maximize Assembly Compliance

Failure Modes & Effects Analysis (FMEA)

• NEED TO INCLUDE INTO AS TO WHAT FMEA IS
• INCLUDE THE SCALE USED TO DETERMINE S/O/D VALUES
• THEN, ADD TO REFERENCE SECTION THE SOURCE FOR THE SCALE

Failure Modes and Effects Analysis - Floor Bike Pump
Item & Function	Failure Mode	Effects of Failure	S	Causes of Failure	O	Design Controls	D	RPN	Recommended Actions
Valve Nozzle Connector	Air leaking out of wheel	Bike tube loses air	3	Misalignment to valve	2	Check if it locks	2	12	Something to help user better secure nozzle properly
	Does not lock	No air transfer into wheel	3	User not using it correctly	2	Check if it locks	3	18	Something that does not use a lock, Make it easier to lock
	Valve may not fit	No air transfer into wheel	1	Wrong valve type	4	Check if it locks	4	16	Make a universal valve, Provide adapters
Pressure Gauge	Air leaking out of wheel	Won't display pressure	2	Broken gauge	1	Test in manufacturing plant	2	4	Better pressure gauge tube seal, Different pressure reading technique
	Incorrectly calibrated	Displays incorrect pressure reading	2	Dropping gauge, Manufacturing error	1	Test in manufacturing plant	7	14	--
Handle rod	Bends	Can not apply downward force, Breaks rod	5	Bars are physically bent forward and not down, Damaged, Improper use	2	--	7	70	Stronger rod
Tube	Air leaking out of wheel	Loss of air from tire	3	Misuse, Damage	3	--	4	36	Tube wrapped in durable material

After analyzing the different failure modes, we have concluded that this product has a very low failure risks and therefore low risk of harm to the user. This is due to the simplicity of the design and that our product is strictly mechanical; electrical connections would most likely add more failure modes to the product. On the other hand, this product deals with high air pressure situations so it is also a delicate instrument which comes with delicate parts. The connection valve has the most parts and therefore the most chances of failing when being used. At the same time, a lot of failures may occur due to the high air pressure which is invisible to the user.

Design for Environment (DFE)

Design for Environment (DFE) can help bring focus to specific areas when improving a design. By analyzing the entire life cycle, the areas of the largest impact can be determined and minimized.

Design for Environment
--	Production	Use
Item Consumed	Bike Pump	Bike
Sector # and Name	#339920: Sporting and athletic goods manufacturing	#336991: Motorcycle, bicycle, and parts manufacturing
Reference Unit	1 Bike Pump	1 Bike
Units consumed per product life	1	1
Cost Per Unit*	$39.04	$234.27
Lifetime Cost*	$39.04	$234.27
Sector mtCO2e per $1M	613	543
Implied mtCO2e per product life	0.0239	0.1272
CO2e Tax @ $30/mtCO2e	$0.72	$3.82

*2002 USD

Production

Using the sporting and athletic goods manufacturing sector of EIO-LCA, we were able to estimate the environmental impact of producing the bike pump. The bike pump costs $50 today, which is about $39.04 in 2002. Power generation and supply has the largest contribution to the 613 mtCO2e per 1 million dollars spent in the sporting and athletic goods manufacturing category. Therefore we can estimate that for every bike pump produced 0.0239 mtCO2e is released into the environment, resulting in a minor $0.72 tax per pump.

Sector #339920: Sporting and athletic goods manufacturing

Economic Activity: $1 Million Dollars

Displaying: Greenhouse Gases

Number of Sectors: Top 10

NEED TO CITE: http://www.eiolca.net/cgi-bin/dft/display.pl?hybrid=no&first_level_sector=Other+Miscellaneous+Manufacturing&second_level_sector=339920&newmatrix=US430CIDOC2002&key=23253747582&value=2527872121&incdemand=1&selectvect=gwp&select_button1=Run+Model

Use

If the consumer purchases a bike pump, we can assume that they own at least one bike. Therefore we used the EIO-LCA Motorcycle, bicycle, and parts manufacturing sector to study the environmental impact of use of the pump. We estimated that today the average bike costs $300 which equates to about $234.27 in 2002. Our analysis approximated a small $3.82 tax per bike.

Sector #336991: Motorcycle, bicycle, and parts manufacturing

Economic Activity: $1 Million Dollars

Displaying: Greenhouse Gases

Number of Sectors: Top 10

NEED TO CITE: http://www.eiolca.net/cgi-bin/dft/display.pl?hybrid=no&first_level_sector=Vehicles+and+Other+Transportation+Equipment&second_level_sector=336991&newmatrix=US428PURCH2002&key=5727070922&value=1515705675&incdemand=1&selectvect=gwp&select_button1=Run+Model

Group Dynamic

Team Leader: Dinesh Ayyappan

DFMA Lead: Patrick Hogan

FMEA Lead: Jonathan Wong

DFE Lead: Amber Ohiokpehai

Wiki Page Programmer/Report Compilation: Lauren Milisits

References

This is where we should list any references that we used throughout the process of our report.