Crankshaft Manufacturing Project report
- 1. Alexandria University Second Year 2017/2018 Facility of Engineering First Semester production Engineering Forming Technology Crankshaft Manufacturing Process This report created by : Names Sections No . Omar Amen Ahmed Mohamed 4 115 Habashy Shabaan Habashy 3 62 Ahmed samy Ali 1 18 Ahmed Ebrahem Bkhit 1 11 Mohamed Ashraf Kamel 5 142 Gheath Mostafa Kojan 5 123 Ahmed Mohamed Abdel-Ghany Al-Ashry 2 33 Dec. 2017
- 2. Table Of Contents Page No. ContentNo. 1Introduction1. 2Main parts of crankshaft2. 2Web2.1 2Counter Weight2.2 2Crank journals2.3 3CRANK JOURNAL PIN2.4 3Flywheel2.5 4Types of crankshafts3. 4Single Throw Crankshaft3.1 4Double Throw Crankshaft3.2 4Four Throw Crankshaft3.3 4Six Throw Crankshaft3.4 5Material Selection for crankshaft manufacturing4. 5Aluminum4.1 5Copper4.2 6Steel4.3 7requirement for crankshaftMechanical properties4.4 7Percentages of Alloying Elements in crankshaft4.5 8Sa Design of Malticylinder Crankshaft5. 10Finite element analysis for crankshaft6. 10STRUCTURAL ANALYSIS OF CRANKSHAFT EXISTING MODEL6.1 12THERMAL ANALYSIS OF CRANKSHAFT EXISTING MODEL6.2 136.3 RESULTS AND GRAPHS6.3 13stress graph6.3.1 13thermal error6.3.2 14Crankshaft Manufacturing steps7. 17field research for crankshaft manufacturing (Nallicheri, 1991).8. 17Conditions of manufacturing8.1 18Cost Analysis9. 18cost analysis for crankshaft weighing 32.6 lbs made of steel9.1 19Conclusion10. 20References11
- 3. Table Of Figures Figure No. Description Page No. Fig.1 Crankshaft and piston 1 Fig.2 Mani parts of crankshaft 2 Fig.3 Crank journal pin 3 Fig.4 Crank flywheel 3 Fig.5 Single throw crankshaft 4 Fig.6 Double throw crankshaft 4 Fig.7 Four throw crankshaft 4 Fig.8 Six throw crankshaft 4 Fig.9 imported model 10 Fig.10 load applied 10 Fig.11 total deformation 11 Fig.12 shows stress 11 Fig.13 shows strain 11 Fig.14 Thermal analysis for crankshaft 12 Fig.15 Stress graph for crankshaft 13 Fig.16 Thermal error for crankshaft 13 Fig.17 Crankshaft Manufacturing steps 14
- 4. List Of Tables Table Description Page No. Table 1 mechanical properties requirement of forged crankshaft 7 Table 2 Nominal Percentages of Alloying Elements in crankshaft 7 Table 3 Manufacturing assumptions for a forged steel crankshaft weighing 32.6 lbs (Nallicheri, 1991). 17 Table 4 Cost breakdown for a forged steel crankshaft weighing 32.6 lbs by factor in the study by (Nallicheri, 1991) 18 Table 5 Cost breakdown for forged steel crankshaft weighing 32.6 lbs by process in the study by (Nallicheri, 1991) 18
- 5. 1.Introduction The crankshaft is located in the engine of a vehicle and converts the force created by the engine's pistons moving up and down into a force that moves the wheels in a circular motion so the car can go forward. Located inside the car's engine, it is connected to all the pistons in the engine and to the flywheel. To understand this shaft, it is important to understand how the pistons and the flywheel work. Fig.1 Crankshaft and piston
- 6. 2.Main parts of crankshaft Fig.2 Mani parts of crankshaft 2.1 Web The portion of a crank between the crankpin and the shaft or between adjacent crankpins called also crank arm, crank throw. 2.2 Counter Weight Crankshaft counter weights are needed to statically and dynamically balance the crankshaft. Without them, the vibrations caused will destroy it. If this is not done, the engine will experience vibrations that will eventually tear up the main bearings and cause damage. 2.3 Crank journals In a reciprocating engine, the crankpins, also known as crank journals are the journals of the big end bearings, at the ends of the connecting rods opposite to the piston.
- 7. 2.4 CRANK JOURNAL PIN The oil passes through the ammonium crank with holes and passes the oil inside the tube into the column to the spike and the connecting column. The oil reaches the crankshaft through a pump located inside the oil filter Fig.3 Crank journal pin 2.5 Flywheel Flywheel is bolted and fixed connected to crankshaft. And we cannot differentiate on macroscopic time scale the power stroke or suction stroke or in which stroke the flywheel is storing the excessive energy. Flywheel just stores the excessive energy in form of kinetic energy and immediately after power stroke crankshaft uses it in other power deficient strokes. Flywheel rotates with same speed as crankshaft Fig.4 Crank flywheel
- 8. 3. Types of crankshafts 3.1 Single Throw Crankshaft Fig.5 Single throw crankshaft 3.2 Double Throw Crankshaft Fig.6 Double throw crankshaft 3.3 Four Throw Crankshaft Fig.7 Four throw crankshaft 3.4 Six Throw Crankshaft Fig.8 Six throw crankshaft
- 9. 4. Material Selection for crankshaft manufacturing Based on the stress imposed on the component during the operation, and operating temperature, the material to be selected for this component should has the following characteristics: • The material should be strong in bending • It must have excellent fatigue resistance. • It must have less coefficient of thermal expansion so that the component can retain its original dimension at varying temperatures. • The material should be easily machinable so that it can take complex shape (as required for the geometry of crankshaft) easily. After carrying out an extensive research of materials, following materials were listed for crankshaft: (Aluminum, Copper, and Steel) 4.1 Aluminum • Aluminum is an excellent machinable metal. It can take complex shapes easily. Moreover, it can absorb vibration very efficiently. However, the metal has lower modulus of elasticity and higher coefficient of thermal expansion. Therefore, it will be subjected to larger strains at higher stresses and high temperatures. Moreover, it does not has good resistance to fatigue and corrosion. 4.2 Copper It is easily machinable and has high strength. Moreover, it has good surface finish which reduce friction. However, the biggest disadvantage of copper is that it is no corrosion resistant. Corrosion rate is higher at higher temperature.
- 10. 4.3 Steel • Steel is another option to be used as a material for crankshaft. Steel is a better choice because, it possess excellent mechanical characteristics which make it better for crankshaft. It has the highest modulus of elasticity. It is tough, strong, easily available, cheap and it has very less coefficient of thermal expansion which makes it best suited for high temperature operation. • An option for crankshaft material is carbon steel. However, these steels require additional heat treatments to acquire required level of strength. • Iron crankshaft is also an option. However, iron cannot take higher loads therefore, iron crankshafts are suitable for low output engines where stresses are lower. They have the advantage of being low cost. • In fact, the most widely used material for crankshaft worldwide is Micro alloyed steel. It has following advantages: • Micro alloyed steel can be air cooled after reaching high strength without further heat treatment. • Low alloy content also makes the material cheaper than high alloy steels.
- 11. 4.4 Mechanical properties requirement for crankshaft Table 1 mechanical properties requirement of forged crankshaft Item Tensile(N/mm²） Yield(N/mm²） Enlogation(%) Reduction area(%) oK(N.m/cm²） Value 550 275 32 14 24.5 4.5 Percentages of Alloying Elements in crankshaft Table 2. Nominal Percentages of Alloying Elements in crankshaft Material C Mn Cr Ni Mo Si V 4340 0.40 0.75 0.82 1.85 0.25 EN-30B 0.30 0.55 1.20 4.15 0.30 0.22 4330-M 0.30 0.85 0.90 1.80 0.45 0.30 0.07 32-CrMoV- 13 0.34 0.55 3.00 <0.30 0.90 0.25 0.28 300-M 0.43 0.75 0.82 1.85 0.40 1.70 0.07 Key: C = Carbon Mn = Manganese Cr = Chromium Ni = Nickel Mo = Molybdenum Si = Silicon V = Vanadium
- 12. 5. DESIGN OF MULTI CYLINDER ENGINE CRANK SHAFT Number of cylinders=4 Bore diameter (D) = 85 mm Stroke length (l) = 96mm Maximum combustion pressure=2.5 N/mm2 We know that force on the piston i,e: gas load n order to find the thrust in connecting rod we should find out angle of inclination of connecting rod with ine of stroke. Assume that the distance (b) between the bearings 1 and 2 is equal to twice the piston diameter (D). b = 2D = 2 × 85 =170mm Due to this piston gas load (FP) acting horizontally, there will be two horizontal reactions H1and H2 at bearings 1 and 2 respectively, such that b1 = b2= 85mm
- 13. Assume that the length of the main bearings to be equal, i.e., 1 = c2 = c / 2. We know that due to the weight of the flywheel acting downwards, there will be two vertical reactions V2 nd V3 at Bearings 2 and 3 respectively, such that
- 14. 6. Finite element analysis for crankshaft 6.1 STRUCTURAL ANALYSIS OF CRANKSHAFT EXISTING MODEL MATERIAL: CARBON STEEL Fig.9 imported model Fig.10 load applied
- 15. Fig.11 total deformation Fig.12 shows stress Fig.13 shows strain
- 16. 6.2 THERMAL ANALYSIS OF CRANKSHAFT EXISTING MODEL Fig.14 Thermal analysis for crankshaft
- 17. 6.4 RESULTS AND GRAPHS 6.3.1 stress graph Fig.15 Stress graph for crankshaft 6.3.2 thermal error Fig.16 Thermal error for crankshaft
- 18. 7. Crankshaft Manufacturing steps Fig.17 Crankshaft Manufacturing steps
- 19. The main manufacturing process of the forged crankshaft is hot forging and machining and this is shown in a flowchart. Each step of this flowchart is described below. 1. The row material samples of the AISI 1045 are inspected for chemical composition. 2. The material is shaped and cut to the rough dimensions of the crankshaft. 3. The shaped material is heated in the furnace to the temperature of 900ºC to 1100ºC. Note: AISI 1045 carbon steel has melting temperature 2660 ºC 4. The forging process starts with the pre-forming dies, where the material is pressed between two forging dies to get a rough shape of the crankshaft. 5. The forging process continues with the forging of the pre-formed crankshaft to its first definite forged shape. 6. Trimming process cuts the flash which is produced and appears as flat unformed metal around the edge of the component. 7. Twisting for 2nd and 4th Main journals 8. The exact shape of the forged crankshaft is obtained in the coining process where the final blows of the hammer force the stock to completely fill every part of the finishing impression. 9. Inspection for all dimensions 10. The machining process starts with the facing and Centering process. The facing process is a machining operation that is a form of turning in which the work piece rotation to produce flat surface. Centering refers to the component according to the final dimensions 11. CAM turning is the process used to produce cylindrical components, typically on a lathe. A cylindrical piece of stock is rotated and a cutting tool is traversed along axes of motion to produce precise diameters and depths. 12. In the drilling operation, all inner diameters are drilled in the crankshaft geometry. The drilling mainly consists of oil holes. 13. The final grinding of diameters sets the cylinder diameters to their final acceptable tolerance. This is followed by grinding of other sections such as grooves using CAM. 14. The final step in grinding is face grinding, where the dimensions of the crankshaft will be finalized.
- 20. 15. The last step in the machining process is balancing the crankshaft. In this process the crankshaft is mounted on two bearings in a device, and the dynamic balance of the component is checked. Mass and location of material removal is specified. Drilling holes in the counter weights will balance the crankshaft dynamically. The balance of the crankshaft is checked once more on the device 16. Final washing of the component and preparation for final inspection. 17. The final inspection consists of checking diameter of cylinders, radius of crankshaft and distance of faces 18. Heat treatment is the next step to obtain the desired mechanical properties for the material.
- 21. 8. field research for crankshaft manufacturing (Nallicheri, 1991). 8.1 Conditions of manufacturing Table 3. Manufacturing assumptions for a forged steel crankshaft weighing 32.6 lbs (Nallicheri, 1991).
- 22. 9. Cost Analysis 9.1 cost analysis for crankshaft weighing 32.6 lbs made of steel Table 4. Cost breakdown for a forged steel crankshaft weighing 32.6 lbs by factor in the study by (Nallicheri, 1991). Table 5. Cost breakdown for forged steel crankshaft weighing 32.6 lbs by process in the study by (Nallicheri, 1991).
- 23. 10. Conclusion • Crankshaft is one of the key components of automobile engine, the performance good or bad will directly affect the service life of the car. Crankshaft is working under heavy load and continuous • The crankshaft is an important part in automobile engine, it will cooperate with connecting rod and change gas pressure rolled in the piston into the rotation of the power, to the transmission mechanism of underpin, drive distribution agencies and other auxiliary devices
- 24. 11. References • ASM Handbook, Volume 14A - Metalworking Bulk Forming • ASM HandBook Volume 14 - Forming and Forging, 9th Edition ,1998 • Stress Analysis and Optimization of Crankshafts Subject to Dynamic Loading, Project report, Farzin H. Montazersadgh and Ali Fatemi , The University of Toledo , August 2007