• Korean Journal of Materials Research
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• v.16 no.11
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• pp.668-675
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• 2006

In the partial squeeze casting process, the filling behavior of liquid metal and solidification pattern in thick area have significant influence on the quality of casting products and die life. For the optimal casting design of automobile transmission gear housing, various analyses were performed in this study by using computer simulation code, MAGMAsoft and the simulation results were compared and analyzed with experimental results. By air pressure criteria, internal porosities caused by air entrap during the mold filling were predicted and reduced remarkably by modification of gating system. Also, optimal squeeze-time lag to apply partial squeeze pin in thick area was calculated and the castings was free from shrinkage defects with the result of solidification analysis. Consequently, casting design for automobile transmission gear housing was optimized and approved by Computer Tomography.

• International Journal of Automotive Technology
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• v.7 no.7
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• pp.847-852
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• 2006

A fitting process carried out in the automobile transmission assembly line is classified into three classes; heat fitting, press fitting, and their combined fitting. Heat fitting is a method that applies heat in the outer diameter of a gear to a suitable range under the tempering temperature and assembles the gear and the shaft made larger than the inner radius of the gear. Its stress depends on the yield strength of a gear. Press fitting is a method that generally squeezes gear toward that of a shaft at room temperature by a press. Another method heats warmly gear and safely squeezes it toward that of a shaft. A warm shrink fitting process for an automobile transmission part is now gradually increased, but the parts (shaft/gear) assembled by the process produced dimensional change in both outer diameter and profile of the gear so that it may cause noise and vibration between gears. In order to solve these problems, we need an analysis of a warm shrink fitting process in which design parameters such as contact pressure according to fitting interference between outer diameter of a shaft and inner diameter of a gear, fitting temperature, and profile tolerance of gear are involved. In this study, an closed form equation to predict the contact pressure and fitting load was proposed in order to develop an optimization technique of a warm shrink fitting process and verified its reliability through the experimental results measured in the field and FEM, thermal-structural coupled field analysis. Actual loads measured in the field have a good agreement with the results obtained from theoretical and finite element analysis and also the expanded amounts of the outer diameters of the gears have a good agreement with the results.

• Proceedings of the IEEK Conference
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• 1998.06a
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• pp.487-490
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• 1998

During driving an automobile, drivers push the clutch and transmit gear by their feeling. At the automobile which have the manually operated gear box by using apart designed equipment, for get the semi-auto function, a lot of research to realize the system which have passive transmission and automotive transmission has developed. In this paper, basically using one chip .mu.-comcontrolled the clutch of automobile by means of LPF, F/V converter and TR driver circuit which is designed. In the past, it was controlled the motor by operating relay which is int eh output system to control the clutch. This system some noises is made by on and off the relay, lessen the motor speed and causes many error due to consume the large power on driving the motor. In this paper, to solve these problems the output TR is operated by using one chip .mu.-com decrease the electic power consumption and designed the actuator to control the clutch by measns of vacuum.

• Journal of KSNVE
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• v.8 no.5
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• pp.841-848
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• 1998

In the gear manufacturing, tooth modification is usually applied for the prevention of tooth impact during the loading. In contrary, tooth profile error causes amplifying the whine noise which is cumbersome to reduce in the automobile gear box. So optimum quantity of the modifications must be obtained for the good performance in the vibrational sense. In this paper, a formulation to define the tooth curve by considering the profile manufacturing error and loading deformation of the gear tooth is suggested and the transmission error and loading deformation of the gear tooth is suggested and the transmission error with modified tooth in the gear system is evaluated. A pair of gear set is mathematically modelled. The equivalent excitation in the gear vibratonal model is formulated. For the experimental evaluaton on the derived transmission error function, a simple geared system is set up in which the gears are designed to give pre-designed tooth profile modification and manufactured by CNC Wire Cutting Machine. Under slow speed operaton, the transmission error of the gear pair is measured by using two rotational laser vibrometers, compared with the calculated one of which the result shows good agreement.

• Proceedings of the KIEE Conference
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• 2005.10b
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• pp.219-221
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• 2005

Various adjustment devices which present automobile uses electric motion motor of reducer built-in type for user's convenience are increasing. The example are seat control motor, sunroof motor, power windows motor etc. To get low noise, high effectiveness special quality in automobile DC motor of reducer built-in type, reducer department's transmission efficiency and noise, vibration quality are very important. The reducer used to DC motor of automobile reducer built-in type use worm gear for enough torque and proper number of rotation. We need optimization design technology of deceleration module including worm gear and housing for reducer development that have special quality of good quality.

• Journal of the Korean Society for Precision Engineering
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• v.25 no.6
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• pp.47-54
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• 2008

Fitting process carried out in the automobile transmission assembly line is classified into three classes; heat fitting, press fitting, and their combined fitting. Heat fitting is a method that heats gear to a suitable range under the tempering temperature and squeezes it toward the outer diameter of shaft. Its stress depends on the yield strength of gear. Press fitting is a method that generally squeezes gear toward that of shaft at room temperature by a press. Another method heats warmly gear and safely squeezes it toward that of shaft. Warm shrink fitting process for the automobile transmission part is now gradually increased, but the parts (shaft/gear) assembled by this process produced dimensional changes in both the outer diameter and profile of the gear. So that it may cause noise and vibration between gears. In order to solve these problems, we need an analysis of warm shrink fitting process, in which design parameters are involved; contact pressure according to fitting interference between outer diameter of shaft and inner diameter of gear, fitting temperature, and profile tolerance of gear. In this study, an closed form equation to predict contact pressure and fitting load was proposed in order to develop an optimization technique of the warm shrink fitting process and verified its reliability through the experimental results measured in the field and FEM, that is, thermal-structural coupled field analysis. Actual loads measured in the field was in good agreements with the results obtained by the theoretical and finite element analysis.

• Korean Journal of Computational Design and Engineering
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• v.16 no.4
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• pp.260-267
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• 2011

Nowadays, automobile manufacturers are faced with increasing global competition which is required low cost as well as high quality. To reduce shipping and handling cost and delivery time, lots of automobile manufactures tried to build their new factory in the neighborhood of market. Simultaneously, many factories are under construction in developing countries to make efficient use of low-wage workers. However, because systems are installed in developing countries as the same type of domestic facilities, systems have lots of problems such as high installation cost and inefficient use of manpower. To find core problems and generate optimal solution of these problems, thinking process of TOC(Theory Of Constrains) is used. In case of transmission gear machining system, semi-auto system is proposed as the best solution to increase manpower efficiency and system utilization. Semi-auto system consists of automatic machining process and manual transporting process. The system layout is generated based on semi-auto process concept. And, 3D simulation method using QUEST is used to verify production volume of generated system.

• Transactions of the Korean Society of Automotive Engineers
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• v.11 no.6
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• pp.190-196
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• 2003

The load sharing and teeth deflection of helical gear system are analyzed to investigate the deformation overlap. The deformation overlap, which is calculated by the results of displacement analysis, is suggested as the basis for the tooth profile modification. Helical gear systems are formulated as contact problems, and solved by elastic contact theory and FEM. The developed computer program, which offers gear teeth deflection and deformation overlap, will be of much help to the improved design of manual transmissions for automobiles.

• 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.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.13 no.5
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• pp.28-34
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• 2014

A planetary gear train is more compact and endures greater amounts of transmission power compared to other gear systems. Although planetary gear systems operate in small volumes, they are capable of very high efficiency due to the compact combination of their gears in the planetary gear system. They also have outstanding efficiency of only 3% for power transmission, tantamount to the power loss that occurs in each of the shift stages. Given these advantages, planetary gear systems are used in the driving systems of, which are widely used in automobile transmissions, machine tools, semiconductor equipment, and in other areas in industrial fields. Current structural equipment requires higher efficiency and greater torque levels. According to these needs, we have designed a complex planetary gear system which creates higher levels of torque. In this paper, an evaluation of strength designs for the proposed planetary gear system was conducted to ensure the stability of the gear. In addition, a durability analysis based on Miner's rule was performed using RS B 0095 device.