• The Safety technology
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• no.194
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• pp.26-28
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• 2014

우리네 생활에 필수요소인 자동차는 수만 가지 부품으로 구성된다. 부품 하나하나는 차량의 안전운행을 위해 반드시 필요하지만 그 가운데에도 파워트레인(동력을 전달하는 일련의 기구, 클러치 변속기 등)은 엔진과 더불어 차량을 구성하는 핵심 요소로 인식되고 있다. 이 파워트레인과 관련된 부품을 전문적으로 생산하는 곳이 바로 오늘의 주인공인 (주)대일이노텍이다. 지난 2005년 11월 설립된 이곳은 끊임없는 연구개발과 다년간 축적된 기술력을 바탕으로 자동차 부품업계의 선두주자로 자리매김했다. 불과 수년 만에 급성장할 수 있었던 원동력은 사람중심의 철저한 안전관리가 바탕이라고 말하는 이곳 회사를 찾아가 봤다.

• Transactions of the Korean Society of Automotive Engineers
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• v.10 no.4
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• pp.114-121
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• 2002

This paper describes the control system of the toroidal traction driver continuously variable-speed transmission(CVT) fur a tractor. The instrumentation system, the hydraulic power control system and the principle control scheme were introduced. Experimental tests in the bench and the tractor were conducted to validate the performance of the CVT utilizing the proposed controller. The speed of the vehicle was continuously changed to follow the speed set by driver under various operating conditions. Given the reduction ratio of the variator from 2.0 to 1.0, the settling time was about just 0.52 seconds which was satisfactory value for working with the tractor. It was also proved that the tractor could work with continuously variable speed under heavy load disturbances.

• Transactions of the Korean Society of Automotive Engineers
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• v.5 no.2
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• pp.13-22
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• 1997

Power flow characteristics of a hydro-mechanical transmission system(HMT) are investigated for tracked vehicle in steering. A HMT consisting of two hydrostatic pump motors(HST), several planetary gear trains and steer differential gear is considered. In order to obtain the direction and magnitude of the power flow of the HMT, network theory for the general power transmission is used. Network model for the HMT in steering is developed, which consists of shafts, nodes and transmission elements such as clutch, gear, etc. Power flow analysis procedure consists of two stages : (1) traction force analysis in steering, (2) power flow analysis in HMT. Torque and speed of every transmission element of the HMT is determined from the network analysis. Also, efficiency, mechanical and hydraulic power loss including HST, are obtained. In addition, the regenerative power flow resulting from steering can be studied in graphic display. The power flow analysis program(PCSTEER) developed in this work can be used as a useful design tool for the tracked vehicle with HMT.

• Transactions of the Korean Society of Automotive Engineers
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• v.12 no.4
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• pp.154-162
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• 2004

In this study, a mathematical model for analyzing the shifting transients of the passenger car with an automatic transmission is proposed. The proposed model comprises a power transmission system and a vehicle system, which are coupled. In order to extract the modeling parameters, on-road car test is carried out. The model is composed of a detailed powertrain, an engine/AT housing, a simplified suspension system, tires and a vehicle body model. On the test, the vehicle accelerations and pitch ratio are measured by using accelerometers and a gyro sensor. The speeds, the brake signal, and the throttle position are taken from sensors which already exist in the vehicle. Considering natural ftequencies, which is calculated from the measured accelerations, and the characteristic equation, vehicle model parameters are identified. Dynamic behaviors during upshift or downshift are simulated using the proposed vehicle model. By comparing and analyzing the simulation result and on-road car test data, the vibration of the Engine/AT housing influences the shifting transients. The effect of model parameters are also studied. Among model parameters, the location of engine mountings influences the vibration of the vehicle body.

• Transactions of the Korean Society of Automotive Engineers
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• v.13 no.1
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• pp.90-98
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• 2005

HMT is a type of continuously variable transmission which has split power flow path characteristics with gear train and hydro static unit. The benefit of improved fuel economy and high power capacity enables it to be a promising application fur large vehicles. This paper presents the analysis results including velocity, static torque, transmission efficiency and dynamic model of the HMT that is developed for city buses. The speeds or gear shafts, the static clutch torque and split power ratio for each mode are detailed here. From the analysis of HMT transmission efficiency considering the power loss in meshed gear and hydraulic unit, we can conclude that minimization of hydraulic power is necessary for improved fuel economy design. Also, the dynamic simulation result for mode shift characteristics shows that little shift shock is observed because of the synchronized rotation speed in clutch.

• 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.

• Transactions of the Korean Society of Automotive Engineers
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• v.3 no.3
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• pp.79-89
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• 1995

Rattle noise occurs at manual transmission as idling and driving of a automotive. It can be solved by torsional characteristics of a clutch disc. A clutch disc consist of a region of pre-damper and main-damper. Rattle noise is affected by pre-damper and main-damper equipped for a torsional spring and friction washer. Pre-damper range covers noise radiating from manual transmission when engine is idling and main-damper range covers noise when engine is driving. The aim of this reserch is to clear transmission rattle noise by way of torsional characteristics of a clutch disc. The experiment is carried out as idling and driving of a automobile equipped for 1.5L MPI engine, dry single-disc type clutch and manual transmission. In this study, the results show for a vibration of manual transmission as idling and driving can be cleared by a clutch disc of Pre-damper type.

• Journal of the korean Society of Automotive Engineers
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• v.17 no.5
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• pp.28-35
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• 1995

본 해설에서는 클러치 제어용 유압계 특성에 대하여 간략히 서술하고 각 장치즐의 장단점을 비교 검토함과 동시에, 본 저자들이 개발한 클러치 조작용 유압계에 쓰이는 압력조절장치에 대하여 설명한다. 1. 변속장치내 클러치 조작용 유압계 특성. 1.1 클러치 조작용 유압계 제어의 필요성. 1.2 변속시 충격 토크의 저감법. 1.3 클러치 조작용 유압계의 제어방식.

• Journal of the KSME
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• v.33 no.10
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• pp.892-901
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• 1993

환경오염과 차량 성능향상에 따라서 날로 강화되는 연비규제는 차량용 변속기로서 CVT 양상 보급에 대한 필요를 앞당기고 있다. CVT는 소형차를 중심으로 일부 자동차 에이커에 의해 이미 실용화되어 있으며 일본 및 구미 자동차 각 사는 CVT에 대한 자체기술을 보유하고 경쟁성 있 는 완성품 개발을 위하여 총력을 기울이고 있는 실정이다. CVT에 대한 연구개발의 추세는 동 력전달 구동요소의 특성에 따라 벨트식과 토로이달 (Torodial)식으로 구분할 수 있으며 대부분의 경우 현재 일부 실용화 개발된 벨트식 CVT가 기술완성도가 높은 반면 토로이달롤러의 각도를 연속적으로 변환시킴으로써 무단변속을 이루는 토로이달 방식은 2000년대 이후에 양산을 목표로 일본 및 영국 등에서 개발 진행주이나 새로운 재질과 제어기술개발 등의 숙제를 안고 있다. 벨 트식의 경우 금속벨트는 지난 십 수년이상 시행착오를 겪으며 CVT용으로 개발된 전문업체의 제품이 이미 특허화되어 있기 때문에 자동차 각사는 벨트와 같은 구동요소보다는 CVT 메카니즘 설계 및 제어시스템 개발에 기술력을 투입하고 있다. 따라서 국내 CVT 개발도 이와 같은 추세를 따를 것으로 기대되고 있으나 AT와 같은 완성품으로서의 상품가치를 갖기 위하여는 CVT에 대한 보다 많은 연구개발이 필요하다고 생각된다.

• Journal of the korean Society of Automotive Engineers
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• v.17 no.5
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• pp.17-27
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• 1995