• Journal of the Korean Society for Precision Engineering
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• v.18 no.9
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• pp.204-209
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• 2001

The finite element model for automotive muffler analysis is improved by modifying the boundary condition of outlet and the mesh of finite element model. The model minimizes the difference between transmission loss from analysis and that from experiment. Four different boundary conditions and the four types of finite element model are tested to find out the best one of those. From the case study it is verified that the bevel of transmission loss can be changed by the variation of radiation impedance value. Also the resonance or anti-resonance frequencies of transmission loss can be shifted by the variation of finite element mesh. An improved finite element model of muffler is proposed in consideration with the accuracy and the computing time of analysis.

• Transactions of the Korean Society of Automotive Engineers
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• v.5 no.1
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• pp.69-78
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• 1997

Main sources of the vibration in gear driving system are transmission error and backlash. Transmission error is the difference of the rotation between driving and driven gear due to tooth deformation and profile error. Vibro-impacts induced by backlash between meshing gears lead to excessive vibration and noise in many geared rotation systems. Nonlinear dynamic characteristics of the gear driving system due to transmi- ssion error and backlash are investigated. Transmission error is calculated for spur gear. Nonlinear equation of motion for the gear driving system is developed with the calculated transmission error and backlash. Numerical analysis of the equation and the experimental results show the existence of meshing frequency, superharmonic compon- ents. Instability of the gear driving motion is found on the basis of Mathieu equation. Rattle vibration due to backlash is also discussed on the basis if nonlinear jump phenomenon.

• Transactions of the Korean Society of Automotive Engineers
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• v.15 no.4
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• pp.41-46
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• 2007

This article deals with the design and prototyping of Shift-By-Wire system for an automatic transmission equipped vehicle. In order to manipulate the shifting action electronically, Shift-By-Wire system consists of an electronic shift lever, an electric shift actuator and position sensors. The shift lever is designed to transform the driver's shifting command into an electric signal; it includes the position sensor using non-contact type hall sensor and an additional shifting switch acting as Tip-tronic. For the design of an electric shifting actuator, we investigated the stroke angles and shifting efforts of the manual control lever in each shifting section. And the position sensor of the shifting actuator is designed by using a potentiometer with an optical encoder. Finally the prototype of Shift-By-Wire system was built in a conventional 2.4L class SUV vehicle, and we performed road tests in order to verify its performance.

• Industrial Engineering and Management Systems
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• v.15 no.4
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• pp.290-297
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• 2016

The successful transfer of technology, needs to recognize the industrial purposes, resources, technology, innovation and the mode of transmission, methods of transmission, influential factors, it's how to recruit and how to develop, and each of these cognitive relies on special expertise. One of the important technologies is automotive technology, and s technology is important for the transition and its development in recent years. Hence, in this paper, after studying Iran and the world's automotive and emerging technologies situation, the status of commercial vehicles and s technology model are studied based on external models, technical specifications, and cost. In this way, we examine the incidence and the applicability of the technology used in the production of heavy-duty vehicles, in recent years, with the passage of time, and we examine the technology lifecycle, from the perspective of physical characteristics and technical features. The results show that the technology of the studied heavy-duty vehicles (Titan) is close to the time of his fall, because spending puberty, so, according to the investigation of new technologies, we should strive to create changes in vehicle technology.

• Journal of the Korean Institute of Gas
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• v.19 no.3
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• pp.49-53
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• 2015

The purpose of this paper is to study and analyze the failure examples for fire by friction on clutch, manual transmission and tire system in a car. In the first example, the driver took the pedal with foot to act the clutch. But the clutch disk did not return from flywheel by leakage of clutch hydraulic line. The heat was produced between clutch disk and flywheel by surface contacting. As a result, it was produced the fire by oil sludge sticked with transmission. In the second example, the transmission system was operated to transfer power of engine by contacting with gear and gear. But, as if the oil of transmission was caused the oil insufficiency because of leaking by crack of transmission case, it found the fact that was produced the fire by deposit material on transmission case. In the third example, when the car's driver continuously pushed an accelerator pedal for escaping from dry pit, the tire took the heat by the friction force between tire and surface of road. As a result, it became the direct cause for the fire. Therefore the driver must manage not to produce the fire with friction parts by heating during running.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.15 no.2
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• pp.66-71
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• 2016

For the manual transmission gearbox used in the automotive industry, gear meshing transmission error is the main source of noise known as gear whine, and radiated gear whine noise plays an important role in the whole gearbox. Therefore, in order to keep competitive in the automotive market, the NVH performance of transmission gearboxes is increasingly important for automotive manufacturers when a new product is developed. In this paper, in order to achieve an optimized tooth contact pattern, gear tooth modification is applied to make up for the deformation of the teeth owing to load. A five-speed MT gearbox is firstly modeled in RomaxDesign software and the prediction of transmission error under the loaded torques is studied and compared. From the simulation, the transmission error and maximum contact stress are also simulated and compared after tooth modification of the loaded torques. Finally, the simulation results are used to optimize the whole gearbox design and the final gearbox prototype is testified to obtain NVH performance in a semi-anechoic room.

• Transactions of the Korean Society of Automotive Engineers
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• v.16 no.3
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• pp.151-158
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• 2008

The clutch system is a subcomponent of the transmission that is designed to engage and disengage power flow between the engine and the transmission. Recently, the engine power of automobile has been continuously increased because of customer's demand for the bigger one. As the engine power is increased, the vibration transmitted to the hydraulic clutch operating system has been increased. Therefore the demand for the reduction of clutch pedal vibration during the operation has been increased. This paper describes the pressure pulsation reduction characteristics of the damper cylinder which is applied to the hydraulic clutch operating system. And the purpose of this study is to propose an analysis model and investigate the effect of the design variable variations for the hydraulic clutch system. Especially, we studied the effect of damper cylinder parameter variations on the hydraulic clutch system performance.

• Transactions of the Korean Society of Automotive Engineers
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• v.3 no.2
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• pp.30-41
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• 1995

Gear rattle is a source of vibration and noise in automotive gearbox casing and generally occurs at or near system resonant frequencies. The neutral gear rattle of the gearbox. is affected by the stiffness and hysteresis torque in the clutch disk and drag torque determining balancing point of the clutch disk operating range. The experiment is carried out in the pre-damper type clutch and a manual transmission of a automobile equipped for inline four-sylinder four-cycle 1.5L MPI engine and the computer simulation is executed by 5th order Runge-Kutta method. The results of the simulation analysis and experimental studies show the dynamic behavior of clutch and a phenomenon of the neutral gear rattle with respect to drag torque and torsional characteristics of the clutch.

• Transactions of the Korean Society of Automotive Engineers
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• v.21 no.5
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• pp.1-7
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• 2013

The present paper relates to a development of the Gear Detection Sensor for automotive manual transmission. To detect air gap from control finger to detecting zone of sensor based on non-contacted method, permanent magnet and linear type Hall IC are mounted in this sensor. Control finger is machined to 3 step heights to detect 3 gear stages such as In-Gear, Normal and Rear. After conducting actual experimentation based on exclusive Jig and FEM, it is described to consider possibility for automotive application of Gear Detection Sensor.

• International Journal of Automotive Technology
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• v.7 no.2
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• pp.155-160
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• 2006

This paper presents a vehicle model for analyzing the transient shifting characterisitics of a passenger car with automatic transmission. Then the presented vehicle model was linked with the dynamic model of an automatic transmission. In order to identify the parameters of the vehicle model, we installed a test equipment with an accelerometer in a conventional vehicle and performed road tests. With the proposed vehicle model, we simulated the dynamic characteristics during shifting, and benchmarked with experimental results. Moreover, a modal analysis was carried out to investigate the effect of the vehicle model in the frequency domain and to obtain the transfer function of the vehicle model. In addition, we showed the numerical results in the time domain for analyzing the effect of each stiffness element, such as engine mountings and suspensions.