introduction and design concept

Kuliah Perancangan Mekanikal-Semester Genap 2010

REVIEWDesign Concept


Perancangan Mekanikal adalah :

Perancangan Mekanikal adalah salah satu pengetahuan rekayasa yang menggabungkan dasar pengetahuan (dasar perancangan, statika struktur, kekuatan material, visualisasi/pemodelan mekanikal) untuk mengembangan konsep rancang bangun dengan spesifikasi standar praktis komponen mekanikal agar menghasilkan suatu rancangan produk yang fungsional, aman, handal, bermanfaat, dapat dimanufakturr dan dipasarkan secara kompetitif

Tujuan Kuliah ini

Kuliah ini disusun sedemikian rupa dengan tujuan agar mahasiswa mendapatkan pemahaman dan kemampuan dasar untuk merancang komponen sistem mekanikal berstandar praktis yang sangat diperlukan sebagai pengetahuan dan keahlian dasar rekayasa seorang lulusan strata satu program studi Teknik Mesin yang inovatif dan berkualitas.


Referensi Pengajaran:

1. Fundamental of Machine Elements, Hamrock, Jacobson, Schmid, Mc- Graw Hill 19992. Machine Design, Kurmi 3. Dasar Perancangan Mesin, Sularso4. Machinery’s Handbook 28th Edition, Erik Oberg, Franklin

D. Jones, Holbrool L. Horton, and Henry H. Ryffel, Industrial Press Inc., 2008, New York, NY - www.industrialpress.com 5. Mechanical Design Second edition, Peter R. N. Childs, Second edition 2004, Elsevier Butterworth-Heinemann.6. Shigley’s Mechanical Engineering Design, Eighth Edition Budynas−Nisbett, 2006, ISBN: 0−390−76487−6.7. Standard Handbook of Machine Design, Joseph E. Shigley, Charles R. Mischke, Second Edition McGraw-Hill, New York, ISBN 0-07-056958-4.


Evaluasi :

Evaluasi untuk menentukan nilai akhir seorang mahasiswa dilakukan melalui :

1. Quiz & Tugas (20%)2. Ujian Tengah Semester (30%)3. Tugas Besar yang meliputi Perancangan

Komponen Sederhana dilakukan secara kelompok &

Ujian lisan per kelompok (50%)

Product Design and Development

(a) Over-The-Wall Engineering Approach (From Kalpakjian [1997]).

(b) Concurrent Engineering Approach (adapted from Pugh [1996]).

Source : Hamrock, Jacobson and Schmid ©1998 McGraw-Hill

1. Shorten the lead-time for the introduction of new products,

2. Lower manufacturing cost, 3. Improve the quality and reliability

of products (good quality), 4. Satisfy the required functions most

effectively

The CHALLENGES in Manufacturing Industry

hig

h rep

etition

desig

n activities =

time co

nsu

mm

ing

=

hig

h co

st of p

rod

uct

General Principles[Product Design and Development, Karl T Ulrich]

Design decisions have substantial impact on product quality and costs

Development teams face multiple and often conflicting goals

It is important to have metrics to compare alternative designs

Dramatic improvements require efforts early in the process

Decision making is supported by well defined methods

Drawing Source : Boothroyd, G., Dewhurst P., Knight W., 2002,

Product Design for Manufacture and Assembly, second edition, Marcel Dekker Inc., New York

1. Identification of What Customer Need

2. Concept Design

3. Calculation :a. Chapter 2: Load, Stress and Strainb. Chapter 3: Solid Materialsc. Chapter 4: Normal, Bending, and Transverse Shear

Stresses and Strainsd. Chapter 5: Deformatione. Chapter 6: Failure Prediction for Static Loadingf. Chapter 7: Failure Prediction for Cyclic and Impact

Loadingg. Chapter 9: Columnsh. Chapter 10: Stresses and Deformations in Cylinders

CONCURRENT ENGINEERING CONCEPT :The Major Concept of Concurrent Engineering (CE) is to put the majority of effort in the product design stage to analyse the factors which might affect subsequent production process, and hence save overall product development time [Product Design and Development, Karl T Ulrich]

DESIGN AND MANUFACTURING AND ASSEMBLY METHODManufacture and assembly (tool of CE) should be considered early in the design cycle is because it is now widely accepted that over 70% of final product costs are determined during design [Product Design for Manufacture and Assembly, Geoffrey Boothroyd, Peter Dewhrust, Winston Knight]

Source : Hamrock, Jacobson and Schmid ©1998 McGraw-Hill

Market Demand

1. Shorten the lead-time for the introduction of new products,

2. Lower manufacturing cost,

3. Improve the quality and reliability of products,

4. Satisfy the required functions most effectively

Manufacturing Processes

Assembly Processes

Different Handling MethodDifferent Insertion MethodDifferent Fastening Method

Final Cost of Product

Early Cost Estimation

Part AttributesDifferent Part Attirbutes

Different Machine

Designer ManufacturerCommunication with cost

Drawing Source: Product Design for Manufacture and Assembly, Geoffrey Boothroyd

Drawing Source: Manufacturing cost estimation for machine parts based on manufacturing fetaures, Jung, J.Y

if the product manufacturing cost can be estimated precisely during the design stage, designers can modify a design to achieve proper performance as well as a reasonable cost at an early stage of the product development process[…..]

Information-Activity-Time-Cost

Information-Activity-Time-Cost

DEVIATION OF COST ESTIMATION DURING

DESIGN STAGE

Drawing Source : Boothroyd, G., Dewhurst P., Knight W., 2002,

Product Design for Manufacture and Assembly, second edition, Marcel Dekker Inc., New York

Drawing Source : Boothroyd, G., Dewhurst P., Knight W., 2002, Product Design for Manufacture and Assembly, second edition, Marcel Dekker Inc., New York

Part Attributes Cp

Cnp

Cm

Ca

A ECB D GF

A

B

Machining Process

Injection Moulding

C Sheet Metalworking

D

F Sand Casting

Powder Metal Processing

Die Casting G Investment Casting

H Hot ForgingE

Manufacturing Processes

H

•Material Cost•Machine Loading and Unloading•Other Nonproductive Costs•Handling Between Machines•Material Type•Machining Costs•Tool Replacement Costs•Machining Data•Rough Grinding•Finish Grinding•Allowance for Grinding Wheel Wear•Allowance for Spark-Out

•Pattern and Core Mold Cost•Core Mould Cost•Pattern Piece Cost•Total Shell Mold Cost•Cost To Melt Metal•Raw Base Metal Cost•Ready-to-Pour Liquid Metal Cost•Pouring Cost•Final Material Cost

•Mould Cost Estimation•Mold Cost Point System

•Die Cost Estimation

•Basic Powder Metallurgy Manufacturing Cost

•Forging Cost•Forging Die Cost•Cost of Flash Removal•Other Forging Cost

Assembly Processes

•Metal Cost•Sand Cost•Tooling Costs•Processing Costs

•Handling Cost•Insertion Cost•Fastening Cost

P Q


R S



•Cost of Individual Dies•Cost of Individual Dies for Piercing Operations•Cost of Individual Dies for Bending Operations•Cost of Miscellaneous Features•Cost for Progressive Dies•Cost of Turret Press Operatios

PManual Assembly

High Speed Automatic Assembly

Robot AssemblyS

Combination Manual and Automatic Assembly

R

Q

FOLDING BIKE DESIGN and MANUFACTURING

Joining Component : Welding, Rivetting, Bolt and Nut, Soldering, Adhesive Bonding

Transferring Power : Axle,Shaft, Coupling, Gearing, Chain, Belt, Brake

Bearing

Text Reference: Figure 1.4, page 21

BYCYCLE COMPONENTS

Manufacturing Costs

Manufacturing Cost

Components Assembly Overhead

Standard Custom LaborEquipmentand Tooling

Support IndirectAllocation

RawMaterial

Processing Tooling

Summary of manufacturing and

non-manufacturing costs

Manufacturing Costs

Direct Materials:

Materials that can be physically and conveniently traced to a product, such as wood in a table. Prime Cost

(Direct Materials + Direct Labor)

Conversion Cost

(Direct Labor +

Overhead Cost)

Direct Labor:Labor costs that can be physically and

conveniently traced to a product such as assembly line workers in a plant. Direct labor is also called

touch labor cost.

Manufacturing Overhead:All costs of manufacturing a product other than

direct materials and direct labor, such as indirect materials, indirect labor, factory utilities, and

depreciation of factory equipment.

Non-manufacturing Costs

DFM method

1. Estimatemanufacturing

costs

1. Estimatemanufacturing

costs

3. Reduce costs of

assembly

3. Reduce costs of

assembly

2. Reduce costs of

components

2. Reduce costs of

components

4. Reduce costs of

supporting production

4. Reduce costs of

supporting production

5. Consider the impact

of DFM decisionson other factors

5. Consider the impact

of DFM decisionson other factors

Recompute manufacturing

costs

Recompute manufacturing

costs

Is it a complex design ?

Is it simple design ?

Drawing Source : Boothroyd, G., Dewhurst P., Knight W., 2002, Product Design for Manufacture and Assembly, second edition, Marcel Dekker Inc., New York


MICRO GEAR

NANO GEAR

500 x10-6

10-9

introduction and design concept

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