• Applied Chemistry for Engineering
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• v.24 no.3
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• pp.274-278
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• 2013

Automatic transmission fluid (ATF) is used as an automatic transmission in the vehicle or as a characterized fluid for automatic transmission. Recently, vehicle manufacturers usually guarantee for changing fluids over 80000~100000 km mileage or no exchange. However, most drivers usually change ATF below every 50000 km driving distance when driving in Republic of Korea according to a survey from the Korea Institute of Petroleum Management which can cause both a serious environmental contamination by the used ATF and an increase in the cost of driving. In this study, various physical properties such as flash point, pour point, kinematic viscosity, dynamic viscosity at low temperature, total acid number and four-ball test were investigated for both fresh ATF and used ATF after the actual vehicle driving distance of 50000 km and 100000 km. It was shown that most physical properties were suitable for the specification of ATF, but the foam characteristics of the used oil after running 100000 km was unsuitable for the specification of fresh ATF. Therefore, the exchange cycle of ATF every 80000~100000 km driving distance is recommended considering great positive contributions to preventing environmental pollution and reducing driving cost.

• Journal of Drive and Control
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• v.20 no.4
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• pp.17-26
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• 2023

A forklift is an industrial vehicle that lifts or transports heavy objects using a hydraulically operated fork, and is equipped with an automatic transmission for the convenience of repetitive transportation, loading, and unloading work. The Transmission Control Unit (TCU) is a key component in charge of the shift control function of an automatic transmission. It consists of an electric circuit with an input/output signal interface function and firmware running on a microcontroller. To develop TCU firmware, the development process of shifting algorithm design, firmware programming, verification test, and performance improvement must be repeated. A simulator is a device that simulates a mechanical system having dynamic characteristics in real time and simulates various sensor signals installed in the system. The embedded transmission simulator is a simulator that is embedded in the TCU firmware. information related to the mechanical system that is necessary for TCU normal operation. In this study, an embedded transmission simulator applied to the originally developed forklift TCU firmware was designed and used to verify various forklift shift control algorithms.

• Proceedings of the KIPE Conference
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• 2015.11a
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• pp.157-158
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• 2015

본 논문에서는 Matlab/Simulink와 Renesas사의 프로세서를 이용하여 차량용 변속 제어를 위한 모델기반 시스템을 구현하였다. 차량용 변속 제어를 위한 전체 시스템 모델은 Simulink와 Renesas사의 Real Time Interface(RTI)를 이용하여 구현한 후에 실험을 수행하였다. Matlab과 Renesas 제어보드의 컴파일러가 설계된 변속기 제어 모델의 C-소스 파일과 Object 파일을 자동으로 생성시켜주기 때문에 사용자에 의한 추가적인 프로그램의 Coding 없이 실제 시스템의 시뮬레이션과 실험을 동시에 수행할 수 있다.

• Korea lubricating oil industries association bulletin
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• no.107
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• pp.8-12
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• 2003

• 발명특허
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• v.5 no.5 s.51
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• pp.39-39
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• 1980

• 발명특허
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• v.30 no.5 s.347
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• pp.59-62
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• 2005

• Journal of the korean Society of Automotive Engineers
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• v.3 no.1
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• pp.27-31
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• 1981

대량생산체제로 제작되는 자동차용 변속기는 일단 양산에 돌입하고부터는 막대한 retooling비 용의 지불없이는 좀처럼 그 모양이나 중요설계치수가 변경될 수 없기 때문에, 초기설계단계에 서의 다양하고 신중한 고려가 그 후의 어느 단계보다 중요하다. 자동차용 변속기의 치차설계자는 치차상의 주어진 공간내에서 가장 튼튼하고 소리없는 치차를 설계하기 위하여 모듈(module), 압력각, 치깊이 등이 표준에서 벗어나는 특수 cutter를 사용하도록 요구할 수밖에 없다(이러한 비표준 cutter의 제작을 위해서는 다소 더 많은 시간과 경비가 소요될지 모르지만, 이 문제는 양산체제의 특수성 속에 충분히 소화흡수된다). 표준치차의 경우에는 대부분의 설계 데이터가 테 이블이나 그래프로 주어져 있지만 모듈, 압력각, 치깊이 등이 표준에서 벗어나는 치차에 있어서는 이것들을 별도로 계산하지 않으면 안된다. 더욱이 세계자동차 메이커가 소형화와 경량화로 치 닫고 있는 현 추세에 있어서는 더욱 정밀한 계산에 의한 데이터가 요구될 것이다. 본 보고서는 임의의 cutter를 사용하여 절삭한 치차의 fillet 부분에 있어서 fillet 곡선의 함수를 구하고 이 것으로부터 lewis방식의 굽힘강도계산식(대부분의 굽힘강도 계산식이 lewis 이론에 입각한 것이긴 하지만)에 사용되는 강도계 수를 approach 법으로 구하는 방법과 계산공식에 대하여 서술한 것이다. 여기서 취급하는 굴절법은 hobbing cutter 등에 의한 rack형 굴절법이다.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.20 no.5
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• pp.639-645
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• 2011

Wheel-loader is a construction vehicle for uploading soil or sand into truck and transportation of materials, which requires large driving power and high rotational speed. To improve the working efficiency, the operator has to shift gears and control levers for bucket & boom simultaneously. Therefore, the automatic transmission has been introduced to enhance operator's convenience and enable effective operation. To develop the automatic transmission for the wheel-loader, technologies such as gears and a clutch-pack design and shift algorithm are required for improvement of shift quality. In this paper, the shift algorithm for the wheel-loader was developed and its shift pattern was analyzed. As the shift control is affected by the pressure profile for the clutch control, the shift quality depending on the pressure profile has been evaluated using experiment and simulation model analysis.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.18 no.6
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• pp.565-575
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• 2009

A forklift (also called a lift truck) is a powered industrial truck that is used to lift and transport materials. It has become an indispensable piece of equipment in manufacturing and warehousing operations. The modem forklift is equipped with automatic transmission to meet the requirement of loading and easy operation of the vehicle. This paper proposes the design of TECU(Transmission Electronic Control Unit) which is applied to PSD322-Axle transmission. Garofalo's control technique is generally used to the automatic transmission. We consider the work quality and market requirement that does not want to control engine throttle. This paper proposes new controller system which guarantees efficient speed changes with simple system. This new system does not control the engine throttle spontaneously. But it has the load of engine and vehicle as a maximum disturbance. The scope of the disturbance is limited to the stoll area of the torque converter. This paper proposes a ideal control commander that converges relative velocity of the input and ouput of a clutch into a zero. We design linear controller to execute the idea control commander. We applied the control algorithm to the forklift of PSD322-Axle type and the performance of this controller was verified.

• Transactions of the Korean Society of Automotive Engineers
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• v.22 no.7
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• pp.1-7
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• 2014

A variable displacement vane pump is possible to improve the fuel economy by varying the pump capacity with a vane mechanism according to the engine operating speed range and reducing its driving torque. In general the experimental evaluation of the vane pump for the transmission has been performed mainly not with the vehicle or dynamometer test rig but with component test rig due to the implementation and safety problems. In this paper, in order to evaluate the performance of the developed vane pump as well as the compatibility with other rotary and hydraulic components of the target transmission, the transmission dynamometer based test rig is implemented where the developed pump is built into it and then the variable pump capacity and effect of power reduction are investigated experimentally.