The process flow chart for the machining line of the connecting rod machining cell consisted of the following machining operation sequence shown in figure 1. Integration of value stream map and strategic layout planning into. Original research open access process capability improvement. Identifying kqcs the acceptable thrust face thickness variation of the con necting rod forgings was. Jan 11, 2018 a connecting rod is a shaft which connects a piston to a crank or crankshaft in a reciprocating engine. A comparison of manufacturing technologies in the connecting rod industry danielle visser. Fatigue analysis of connecting rod using finite element. The press applies 2,000 tons of pressure onto the slug, forging it into the basic shape of a piston.
Doug woodyard, in pounders marine diesel engines and gas turbines ninth edition, 2009. Connecting rod is highly stressed component, as it is subjected to the cyclic dynamical tensile and compressive loads. Traditional machining processes consist of turning, boring, drilling. Design, simulation and manufacturing of a connecting rod from ultra. The proper condition of a connecting rod is fairly straightforward. This became one of the strengths of the powder forging. After analysis a comparison is made between existing steel connecting rod viz. Pdf process capability improvement of an engine connecting. Since the end of 20, the connecting rod production hall has undergone a number of changes at the mannheim plant. The remaining portion of the connecting rod market segment. It is important that the 2 holes in the connecting rod are parallel in both planes for the engine to run smoothly. Apr 04, 2014 since the end of 20, the connecting rod production hall has undergone a number of changes at the mannheim plant.
Engine connecting rod an overview sciencedirect topics. Pdf statistical process control is an excellent quality assurance tool to improve the quality of. Pdf preparation steps of a connecting rods 3d geometry to be. Original research open access process capability improvement of an engine connecting rod machining process gvss sharma1 and p srinivasa rao2 abstract statistical process control is an excellent quality assurance tool to improve the quality of manufacture and ultimately scores on endcustomer satisfaction. Residuals based process capability indices for twostage processes residuals based process capability indices for twostage processes.
Us5878491a process for the manufacture of a forged. In this process casted or forged cam are in the required shape but their size is maintained by machining and finishing operation. Connecting rod made by steel forging will greatly achieve high performance applications. The application of the fs method for the production of the connecting rod using sintered forged steel was started in the 1990s 1. A connecting rod rough forging, free of lateral flash and including at least one bore initiator on the big end and on the small end, is manufactured by forging. The photo shows a centre drill being used to, centre the rods. Con rod machining technology leader in fracture splitting since the beginning of the nineties, the first fracture splitting tests of con rods were realized and the technology was implemented into the production equipment. Modern manufacturing process of forged connecting rod. Figure 1 presents schematic illustrations of a connecting rod and its location and function in an engine. Processbased tolerance assessment of connecting rod. Carbon steels or alloy steels are the most commonly used materials. Pdf processbased tolerance assessment of connecting rod. Standardization can be repetitive operation,the repeatability is capable of producing consistent forged connecting rods,guarantee the. In order for the wrought forged rods to be crackable the carbon content.
The process described here machines both the critical holes using a boring tool on the face plate, to keep things as parallel as possible. Connecting rods manufacturing improvements and process planning. A connecting rod is a shaft which connects a piston to a crank or crankshaft in a reciprocating engine. The third process, machining, is only applied to unitary or very small production batches, due to the high cost involved in the whole process, whereas from the waste it generates or the high machining time and men hours it requires. Below are flow charts comparing the steps of powder forged and conventional. This method includes the steps of fine blanking the shank and cap portions of the rod, and simultaneously broaching these portions to obtain mating serrations on the crank pin bore and the shankcap interface. Forging creates much more ideal grainflow than a machined billet rod cut from sheet due to grain end exposure but i have to wonder how much it would matter in this type of application.
Evaluation of crankshaft manufacturing methods an overview. Us5787763a process for manufacturing a connecting rod made. Us20110214529a1 machined titanium connecting rod and. Agenda manufacturing of connecting rod forging vs casting defects of forging. The connecting rod is required to transmit the compressive and tensile forces from the piston, and rotate at both ends. Concept and manufacture of a crankshaft production tool. Method for the manufacture of connecting rods for small. I started off,by filing off any high points, then marking centre lines along the sides and the ends of the rods. Example connecting rod manufacturing process without the equator gauge. This is where the wrist pin will go, which is used to attach the piston to the connecting rod during engine assembly. The tolerance chain diagram methodology is applied to the connecting rod in order to verify the manufacturing process tolerances at various operations of the connecting rod manufacturing. This paper elaborates on one such kqc of themanufacturing of a connecting rod of an internal combustion engine.
Forging creates much more ideal grainflow than a machined billet rod cut from sheet due to grain end exposure but i have to wonder how much it would matter in this type of. We have also developed the fracture split crack connecting rods the latest high quality and high accuracy process for forging and casting. The applications of the fs method for the connecting rod using a high fatigue strength material were then examined due to the requirement of improving the engine performance and the fuel economy. Con rod machining machines for manufacturing con rods have been a key part of our product line from the very beginning. The connecting rods are supplied as two brass forgings, and require considerable machining before completion. Processbased tolerance assessment of connecting rod machining process article pdf available january 2016 with 337 reads how we measure reads. In fact, the entire production hall configuration had to be adapted to the connecting rod machining centers. Multiple weight designs targeting specific markets combined with our finely tuned manufacturing process renders a truly outstanding product.
Development of fracture splitting method for case hardened. Together with the crank, it forms a simple mechanism that converts reciprocating motion into rotating motion it is the main function of a conne. This type of connecting rod is created by drop forging the heated metal bar into net shape, then just do less machining to finished product. The biggest advantages of programmable forging hammer is that it can standardize the production process. First the conrod was mounted in the 4jaw chuck as shown here and set to run true. First the con rod was mounted in the 4jaw chuck as shown here and set to run true. The centre connecting rod has a palm end at the lower end to which the bottom endbearing keeps are bolted, whereas the upper end of the rod has an integral continuous lower half keep to which the upper halfbearing keeps are bolted. Bringing the part to final dimensions under tight tolerance. Process tolerancing based on the process capability studies is the optimistic and pragmatic approach of determining the manufacturing process tolerances. We could open the cover from connecting rod, thus manufacturing cost was saved.
The milling machine a milling machine then shaves up to a couple of centimeters off of each side of the piston where the large holes were drilled for the wrist pin insertion. A method for economically manufacturing connecting rods for small reciprocating engines having a mating shank and cap. Together with the crank, the connecting rod converts the reciprocating motion of the piston into the rotation of the crankshaft. Apr 16, 2014 in depth behind the scenes look at hot rods u. Forged connecting rods manufacturers for auto industry. The prototype of the connecting rod is made using direct machining for aluminum alloy. Pdf process capability improvement of an engine connecting rod. Manufacturing process material cutting to length of material. Another advantage besides tolerance was that we could forge connecting rod cover together with the rod. In this process only machining is required to manufacture cam. Process capability improvement of an engine connecting rod. Study on machining of cracking notches for automotive.
This process generates a lot of heat, so the piston must be air cooled for one hour. A process for manufacturing a forged connecting rod of the type including a big end, a shank and a small end. Here the machining process has begun, the spigot and the outside of the big end have been turned. On adopting the definemeasureanalyzeimprovecontrol approach, the process potential capability index c p and the process performance capability index c pk values of identified process characteristics of connecting rod machining. Supplier of connecting rods, exporter of connecting rod. Design and analysis of connecting rod using forged steel. The rod must be straight, centertocenter rod length must meet design specs, the pin bore and bigend bore must be perfectly round, each bore must be sized appropriately for wrist pin and crank. Jan 21, 2016 process tolerancing based on the process capability studies is the optimistic and pragmatic approach of determining the manufacturing process tolerances. The invention of the crank connecting rod system has enabled the invention of numerous machines the most notable of which is the internal combustion engine. Substantial construction projects made room for two new connecting rod machine tools. Selection of material, shape and manufacturing process for a connecting rod abstract this activity centers on the courses of strength of materials and production design offered at a sophomore level mechanical engineering curriculum.
Connecting rod is highly stressed component, as it is subjected to the cyclic dynamical tensile and. Process capability improvement of an engine connecting rod machining process article pdf available december 20 with 312 reads how we measure reads. A connecting rod is one of the most mechanically stressed components in internal combustion engines. Every of these technologies requires additional machining operations. Automotive connecting rod, motorcylce connecting rod. Fatigue analysis of connecting rod using finite element analysis 789 the stress at any point on the connecting rod at this axial load can be interpolated from the axial stress analysis results. The prototype of the connecting rod is made using direct machining for aluminum alloy and hand layup method for carbon fiber connecting rod.
Selection of material, shape, and manufacturing process for a. The typical aluminum rod is forged from 7075 and heat treated to t6 specifications. A connecting rod, also called a con rod, is the part of a piston engine which connects the piston to the crankshaft. Casting process for manufacturing crankshaft 4 machining is a material removal process from a billet with a required diameter. A connecting rod according to claim 3, characterised in that the connectingrod bigend is divided and the connectingrod bearing cover comprises a second sheetmetal strip 14 with peripheral webs 17 bent substantially perpendicularly, which is bent semicylindrically about the bearing axis of the connectingrod bigend. With these factors in mind, this process enables the forging of a crankshaft from a single rod in a single operation combining the knowledge on buckling with a flexible tool. Under drop forging process, it is able to withstand much greater loads and faster engine revolutions than a cast rod. Firstly, process parameters of notch have been analyzed, and project of machining notch using wedm has been introduced, including. Processbased tolerance assessment of connecting rod machining process processbased tolerance assessment of connecting rod machining process. Fabrication process for carburized fs connecting rods.
A process for forming a remateable machined titanium powder base alloy connecting rod using a titanium alloy powder having an average particle size of about 120 microns, a mean aspect ratio of about 5 to 300, and a specific surface area of at least about 25 m 2 g. Alloy steels are used for manufacturing conrods for high performance engines as they provide the required cyclic strength without substantially increasing the dimensions of critical sections. A comparison of manufacturing technologies in the connecting. However, machining processes inevitably waste material in the form of chips, production rates may be low, and unless carried out properly, the processes can have detrimental effects on the surface properties and performance of parts. Geometry for a connecting rod with straight split ic engine handbook, r van basshuysen10 connecting rod is the main component of the combustion engines. For example, roundness values and cylinder forms of our rotation parts of pdf schrauber kommuniziert mit nutzer. Connecting rod machining process improvement scientific. Air gauges manual inspection of diameter, circularity. Statistical process control is an excellent quality assurance tool to improve thequality of manufacture and ultimately scores on endcustomer satisfaction.
In this paper, analysis and study connecting rod machining process, through the improvement plan, ensure the accuracy of the important parts of the. The manley pro series ibeam rod has become the benchmark for fully machinedbillet style high end connecting rods in the performance industry. Connecting rods are available in a variety of sizes and materials ideal for certain situations. The connecting rod provides the mechanical linkage between piston and crankshaft and must exhibit properties of high strength, low inertial mass, and uniformity of mass with the other connecting rods attached to the crankshaft. On adopting the definemeasureanalyzeimprovecontrol approach, the process potential capability index c p and the process performance capability index c pk values of identified process characteristics of connecting.
Connecting rod manufacture is a high volume, price sensitive application with strict performance, design and durability requirements. The current manufacturing processes for connecting rods by fracture split drop. Table 1 describes the machining operations of the connecting rod manufacturing cell. Process based tolerance assessment of connecting rod machining process process based tolerance assessment of connecting rod machining process. The crosssection of the shank of the connecting rod may be rectangular, circular, tubular, isection or hsection as shown in following diagram. Coupling to the crankshaft is achieved through solid journal. The connecting rod rough forging is sized, contentwise, by plating the connecting rod rough forging between two inserts. Spcuses process monitoring charts to record the key quality characteristics kqcsof the component in manufacture. While using metal billet metal rod, the profile of cam is obtained by removing excess material which from metal billet. As tolerance chain analysis is an essential activity in process planning for geometry assurance, a tolerance chains study based on monte carlo simulations for the connecting rod line has been performed to develop. Selection of material, shape, and manufacturing process. The third process, machining, is only applied to unitary or very small production batches, due to the high cost involved in the whole process, whereas from the waste it. The billet process makes it much easier to locate the counterweights.
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