• Journal of the Korean Society of Manufacturing Process Engineers
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• v.13 no.4
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• pp.69-74
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• 2014

A waste gate valve (WGV) assembly for a gasoline turbocharger is typically manufactured by means of precision casting. In this study, however, it was newly manufactured in a more innovative way, metal injection molding (MIM) using Inconel 713C alloy, and its performance was tested in a 1.6L direct injection gasoline engine by a thermal shock durability test that lasted 300 hours, after which the results were compared to those of a precision-cast WGV assembly with regard to the engine intake boost pressure, turbine wheel speed, and transient intake pressure. It was found that the two WGV assemblies showed similar performance levels throughout the durability test.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2013.10a
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• pp.686-686
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• 2013

Automotive turbochargers have become common in gasoline engines as well as diesel engines. They are excellent devices to effectively increase fuel efficiency and power of the engines, but they unfortunately cause several noise problems. The noises are classified into mechanical noises induced from movement of a rotating shaft and aerodynamic noises by air flow in turbochargers. In addition to, there is a mechanical noise caused from movement of an actuator, electronically controlling a wastegate valve. It is called as valve rattle noise. The actuator is connected to a valve through a linkage. The noise occurs only if the valve is open, where the linkage is freely contact to neighbor structures without being constrained by any external forces. This condition allows impacts by the pulsation of exhaust gas, and the vibration from the impacts spreads out through turbine housing, causing the rattle noise. The noise is not in mechanical operating wastegate turbochargers because the linkage of an actuator is strongly connected by actuating force. For the electronic wastegate turbocharger, this paper proposed a test device to show the noise generating mechanism with a small vibration motor having an unbalanced shaft. It also shows how to reduce the noise - reduction of linkage clearances, inserting wave washers into a connection, and applying loose fitting in bushing embracing a valve lever to turbine housing.

• Transactions of the Korean Society of Automotive Engineers
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• v.24 no.2
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• pp.232-241
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• 2016

The turbocharger, to decrease the harmful exhaust gas(CO, HC and etc.) and $CO_2$ emission as well as the increase of the engine output, would be an useful method for engine downsizing. Therefore the thermal endurance of turbine blade, the lubrication of turbine shaft and the engine knock according to the supercharge of the inlet air, had been studied. And there had been much progress in these research tasks to be achieved a breakthrough. But a study on the built-in WGV of a gasoline engine for a passenger car which may effect on the engine performance, is few. In this paper, the effect of the embedded WGV on the engine performance was performed through the endurance test, which was conducted more than 300 hrs using the 4 stroke, 1998 cc, water-cooled engine. To sum up the major results, there were an abrasion in the area of the WGV head edge and the thermal deformation on the WGV head face, These phenomena led to reducing the boost pressure which caused the reduction in the volumetric efficiency of the engine. It resulted in decreasing the engine power gradually during the life cycle of the embedded WGV.