manufacturing technology introductionutopm.fsid.cvut.cz/...1_introduction_manufacturing.pdf ·...
TRANSCRIPT
Technology II
Manufacturing technologyIntroduction
Technology II –
Ing. Jan Tomíček Ph.D.Room no. B1-114
Manufacturing
• Important part of World economy. Allmost all products are manufactured.
• Demands are increasing
• New issues – energy efficiency, waste, etical issues
Changes in the world of goods manufacturing
1. World wide competetion
2. New materials
3. Advanced technologies
4. New manufacturing systems
5. Enviromental issues
1. World Wide Competetion
• Global business
• Market = Whole world
• Everybody can make business –
– knowledge vs. capital
– customization vs. mass production
– Product placement vs. variability
2. New materials
• Demands from customers– Smooth surface on plastic parts
– Transparency of plastic
– Shiny metal look etc.
• New developed materials with betterproperties– Heat resistant materials
– High strength materials
– Special materials
3. Advanced technologies
• Complex products
• Combined principles
– Mechanical principles
– Electrical
– Electronical
– Combination
• Water, steam, electricity,
4. New manufacturing systems
• Manufacturing system
• Manufacturing strategies
• Management
5. Enviromental issue
• Low energy and material consumption
• Utilization of human labor, heavy work
• Health and security issues
• Ethical problems
Product Life Cycle
Design
Construction
Manufacturing
Sale
Service andrecycling
START-UP RAPID GROWTH MATURATION COMODITY or DECLINE
Product variety Great variety, productinnovation
Increasingstandartization
Emergence of a dominant stadart design
High standardization„comodity“ characteristics
Industry structure Small competetiors Fallout andConsolidation
Few large companies „Survivors“ becomecomodities
Form of competetion Product characteristics Product Quality, Costand availability
Price and Quality andReliability
Price with consistentquality
CostPer unit
Annual sales per model
SATURATION
TIME
Price of the product?
• What is the best price of the product?
Smallest, affordable, highest, psychologicallyfriendly, discounted??
Production costs!
Manufacturing costs
• Methods:
– Casting, foundry, moulding
– Forming of metalforming
– Machining(material removal)
– Surface treatments(finishing)
– Heat treatment
– Joining and assembling
• Machining is approx. 40% of manufacturing costs
TECHNOLOGY II
TECHNOLOGY I
Machining
• Chip removal process – Material is removed in form of chips from a piece of raw material to archive the desired shape.
• Material(chips) are removed by a tool from the blank
• This process is called „Chip forming“
What you allready should know…
• Course Technology II presumes knowledge ofbasic technologies of machining
• Prerequisite is course „Fundamentals ofTechnology“.
17
ADVANTAGES• variety of work materials
• variety of part shapes and geometric features
• dimensional accuracy
• good surface finishes
DISADVANTAGES wasteful of material
time consuming
Material Waste?
Material utilization
20
MACHINING (conventional)a sharp cutting tool is used to cut away
material to achieve the desired part
shape and quality
21
A CUTTING TOOL
• single-point tool (a)
• multiple cutting edge tool (b)
Chip forming principle
• Continuous vs. discontinuous chip
Forcestresswork hardeningsaturation(fullyhardened material)shearconinuous chip
23
CHIP FORMATION (orthogonal cutting schema)
• the tool is forced into the material
• plastic deformation → hardening of the material
• shear deformation – shear plane (angle φ)
24
CHIP FORMATION
Secondary deformation zone
Chip breakers
• Preventing the built-up edge
– Groove type - premanufactured
– Obstruction type
Chip and Tool geometry
• Tool – rake & face angle
Chip thickness
• Chip thickness ratio𝛬ℎ =
𝑡𝑐𝑡𝑜=𝑡𝑐𝑎𝑝
29
CUTTING CONDITIONS• cutting speed vc [m.s-1]; [m.min-1]• feed f [mm.rev-1]; [m.min-1]• depth of cut d = ap [mm]
Chip types
Chip breaking diagramme
Chip breaking diagramme
Chip volume ratio
• Calculation W =
• Value 3-400
• Large volume of chips
𝑊 =𝑉𝑐𝑉𝑜
Chips removal
• Chips must be removed
– From the cut – gravity, liquid, air etc.
– From the machine – liquid, automatic, manually
– From the workshop – conveyors, carriages
– From factory –
• recycling
What to think about?
• Next time
– resistance of material,
– cutting forces,
– heat and temperature