• 한국소음진동공학회:학술대회논문집
• /
• 한국소음진동공학회 2006년도 추계학술대회논문집
• /
• pp.556-561
• /
• 2006

In this study, the failure of the automotive clutch disk was investigated. During the process of power transmission, clutch disk plates did repeated work of releasing and engaging the pressure plate. The effects of unbalance rotation in the abnormal vibration and torque amplitude under engaged state were measured from this experiment. In order to reduce the unbalance, a modified clutch disk shape was developed. With a three-dimensional model of the stopper pin, to predict fatigue fracture, finite element analysis was carried out and evaluated the improvement of the new clutch disk.

• Tribology and Lubricants
• /
• 제22권4호
• /
• pp.196-202
• /
• 2006

This paper presents a case study on the tribological failure analysis of a clutch system for a manual transmission car. The clutch systems are composed of clutch disk, clutch pressure plate, flywheel rubbing surface, coil and diaphragm springs, release bearing and lever, clutch spline and shaft. The purpose of a clutch system is to transmit and disconnect the driving power of engines by frictional farce from a rubbing surface of a flywheel to a clutch disk and clutch pressure plate with a minimum power loss. In this study, many tribological failure cases based on the wear phenomena and thermal distortions have been presented, which are collected from the car repair shop and maintenance center. The triboiogicai failures are mostly come from the driving conditions, overloading of a car, and especially driving style and personal habit of a car driver.

• 한국항행학회논문지
• /
• 제12권3호
• /
• pp.208-214
• /
• 2008

자동차 산업의 발전에 따라 보다 편리한 기능의 자동차 부품 기술 개발이 꾸준히 진행되어 왔으나, 운송 수단 발명 초기에 개발되었던 수동 클러치 방식은 수많은 연구와 개발자들의 노력에도 불구하고 아직 오토미션 수준의 초기 단계에 머물러 있다고 볼 수 있다. 종래의 오토 미션은 클러치 디스크의 슬립을 기초로 한 소형차량 및 개인용 RV 차량 위주로 사용되고 있으나, 본 연구 기술은 대형 차량부터 소형 승용차 및 농기계, 선박 등 클러치를 조작하는 모든 수송 기계에 적용이 가능한 혁신적인 기술이다. 차량의 운전 조건에 따라 달라지는 엔진의 출력 값에 따라, 클러치 디스크의 접속 시점을 정확히 결정하고 수동 변속기의 경우 빈번히 나타나는 반 클러치 상태를 적용하기 위하여, 클러치 디스크의 접속 시점을 결정하는 기준이 되는 데이터로 엔진(Engine)의 회전수(rpm)를 적용한다. 상승하는 엔진 회전수에 해당하는 값 만큼만 클러치 디스크를 이동, 접속시켜 차량의 동력을 원활하게 전달할 수 있는 자동차용 전자식 클러치 모듈을 연구하였다.

• 드라이브 ㆍ 컨트롤
• /
• 제15권3호
• /
• pp.14-20
• /
• 2018

Wet clutches in an automatic transmission enable the transmission of the engine power by the frictional torque experienced and noted between disk and plates. Since the clutch frictional torque considerably affects the shift quality of an automatic transmission as well as the durability of the machinery, its friction characteristics must be carefully examined to meet the design requirements. The SAE No. 2 friction test machine is a well-known standard to evaluate mainly the friction characteristics of plate clutches along with the required automatic transmission fluids. This paper reviews the experimental analysis of the wet clutch friction characteristics by using the exclusively developed clutch test machine which is capable of controlling the clutch test procedure, in accordance with the applicable test standard and processing of the experimental data automatically. As the clutch test machine is designed for the accommodation of dual clutches which is applied to the real transmission, it can evaluate not only the clutch friction characteristics, but also an actuation performance of a measured clutch piston. In respect to friction characteristics involving dynamic friction coefficients, the energy absorbed in a clutch disk and the recorded temperatures of clutch plates during braking actions and procedures are also investigated. Additionally, the change of friction coefficients by the use of the repeated clutch application is also observed with the endurance test functions of an accurately calibrated and dedicated clutch test machine.

• Tribology and Lubricants
• /
• 제25권4호
• /
• pp.243-249
• /
• 2009

A magnetic clutch consists of pulley and disk. It delivers and isolates the power needed for the operation of the compressor used in automotive air conditioning system. To improve the performance, efficiency and durability of automotive air conditioning system, appropriate design of pulley, disk and system working parameters(the magnitude of magnetic force, and so on) is necessary. For that goal, it is required to understand the friction characteristics of magnetic clutch for the initial operating time. In this study, friction tests were carried out in order to investigate the effect of sliding velocity on the friction characteristics of magnetic clutch using pin-on-disk type friction and wear tester. For experiments, pulley and disk used in real automotive air conditioning system were considered. Friction experiments were conducted under various sliding velocities, and coefficients of kinetic friction were obtained. Under the experimental conditions considered in this study, the coefficients of kinetic friction increased with the increase of test number(sliding distance) and decreased with the increase of sliding velocity.

• 한국자동차공학회논문집
• /
• 제3권2호
• /
• pp.30-41
• /
• 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.

• 한국자동차공학회논문집
• /
• 제14권1호
• /
• pp.54-59
• /
• 2006

An analytical solution for deflection-load characteristics of a conical disk spring used especially in the automotive manual transmission clutch applications is proposed in order to take into account the effects of friction and large deformation. The conical disk spring, or the diaphragm spring, has a hinge support, an application point of release load at the tip of the fingers and an application point of clamp load near but inside the outer perimeter of the conical disk spring. The friction coefficient is assumed to be a constant regardless of the speed of deflection and the magnitude of loads. Comparison with experimental shows a good agreement with the analytical prediction. Also, the sensitivity of the clamp load due to variations in the geometrical parameters of the conical disk spring is calculated and discussed.

• 한국자동차공학회논문집
• /
• 제3권4호
• /
• pp.19-29
• /
• 1995

This paper discusses the stick-slip phenomenon of the driveline system of a vehicle in consideration of friction. Friction is operated on the between of flywheel and clutch disk. The expressions for obtaining the results have been derived from the equation of motion of a three degree of freedom frictional torsion vibration system which is made up driving part(engine, flywheel), driven part(clutch, transmission) and dynamic load part(vehicle body) by applying forth-order Rungekutta method. It was found that the great affect parameters of the stick-slip or stick motion were surface pressure force between flywheel and clutch disk, time decay parameter of surface pressure force and 1st torsional spring constant of clutch disk when driveline system had been affected by friction force. The results of this study can be used as basic design data of the clutch system for the ride quality improvement of a car.

• 한국공작기계학회:학술대회논문집
• /
• 한국공작기계학회 2001년도 춘계학술대회 논문집(한국공작기계학회)
• /
• pp.66-71
• /
• 2001

In this work, an ER clutch has been constructed and its characteristics have been evaluated by adapting an electro-rheological fluid(ERF) as an operating medium. ER fluids are suspensions which show an abrupt increase in rheological properties under electric fields. An ER clutch system using ER fluid is a new conception device because an apparent viscosity of ER fluid can be changed by apply an electric field. As a first, Bingham properties of ER fluids are experimentally distilled as a function of electric field. We use the disk type ER clutch in which the ER fluid fills the annular space between a pair of coaxial disk electrodes and experiment results show that the measured revolution per minute was increased with the increase of the electric field. The ER fluid used in the present study consists of weight fraction 35% in zeolite suspended silicone oil.

• 한국산학기술학회논문지
• /
• 제20권10호
• /
• pp.117-124
• /
• 2019

국군이 운용중인 대부분의 군 전용차량은 개발이 완료된지 15년이 넘었으며, 개발 당시의 기술력과 정비성을 고려하여 수동변속기를 채택하고 있다. 수동변속기는 엔진과 변속기 사이에 동력을 조절/차단하는 클러치를 포함한다. 본 연구의 대상이 되는 2.5톤 군용차량은 수동변속기와 클러치 시스템을 적용하고, 클러치 커버와 릴리스 베어링 간극을 수동으로 조절해야 했다. 이러한 특성으로 인하여 클러치 디스크 조기마모, 클러치 커버 파손 등의 품질문제가 발생하였다. 본 연구는 발생된 품질문제를 해결하기 위하여, 클러치 커버와 릴리스 베어링의 간극을 자동으로 설정하도록 하고 클러치 디스크 자체의 성능도 향상시키는 과정을 거쳤다. 개선된 시스템을 평가하기 위해서, 단시간에 기어변속을 하는 가속내구시험을 수행하였으며 추가적으로 군인이 직접 운전을 하여 차량에 적용하였을 때 이상이 없음을 증명하였다. 본 연구활동을 통해, 클러치 간극을 조정할 필요가 없도록 하여 차량 정비 인력의 정비시간을 단축하였다. 또한, 클러치 간극을 조정해 주지 못함으로써 발생되는 품질문제를 해소하여, 근본적인 개선책을 제시하였다고 볼 수 있다.