• 한국소음진동공학회논문집
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• 제24권1호
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• pp.54-61
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• 2014

This paper proposes a driver supportive device with haptic cue function which can transmit optimal gear shifting timing to a driver without requiring the driver's visual attention. Its performance is evaluated under vehicle model considering automotive engine, transmission and vehicle body. In order to achieve this goal, a torque feedback device is devised and manufactured by adopting the MR (magnetorheological) fluid and clutch mechanism. The manufactured MR clutch is then integrated with the accelerator pedal to construct the proposed haptic cue device. A virtual vehicle emulating a four-cylinder four-stroke engine, manual transmission system of a passenger vehicle and vehicle body is constructed and communicated with the manufactured haptic cue device. Control performances including torque tracking and fuel efficiency are experimentally evaluated via a simple feed-forward control algorithm.

• 한국생산제조학회지
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• 제20권6호
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• pp.692-696
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• 2011

A clutch is a very important component when engine starts and gear shifting is needed. The clutch the most commonly used is the dry clutch. This type of clutch has pads, and they are worn after disengagement of clutch little by little. The characteristics of the clutch changes as these pads wear, so wear needs to be measured, and the clutch should be controlled for proper operation. In this study, the clutch contact point estimation algorithm has been developed. From this algorithm, clutch force map changes depending on wear, and the clutch operates properly. We also see the shifting transient of a vehicle for drivability with throttle valve position control and synchronizer movement.

• Journal of Advanced Marine Engineering and Technology
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• 제36권5호
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• pp.700-706
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• 2012

이동식발전설비에서 시동장치의 핵심기술은 피니언기어 쉬프팅 장치와 초기 기동전압을 제한하는 것이며 기존의 제품에서는 기계적 주접점을 이용한 시동 제어장치를 사용하고 있다. 하지만 완전한 피니언기어 쉬프팅 후 시동전동기의 기동의 불확실성이나 대전류에 의한 주접점의 아크손상 등의 큰 문제점을 가지고 있다. 본 연구에서는 이러한 문제점을 해결하기 위해 기동의 불확실성 제거를 위한 피니언기어 쉬프팅 제어회로, 대전류에 의한 접점의 아크손상 방지를 위해 반도체 소자를 이용한 시동 제어시스템, 직권전동기의 소프트 스타팅을 위한 기동 안전장치 등을 새롭게 설계, 제작하여 안전성과 신뢰성을 얻고자 하였다. 또한, 피니언기어 제어회로와 전동기 전원회로를 분리하여 전기적 안전성을 확보하였다.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2001년도 춘계학술대회 논문집(한국공작기계학회)
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• pp.435-440
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• 2001

In this study, torsional and lateral vibrations of a gear box transmission system were analyzed theoretically using some mathematical models and examined to determine the causes of its excessive vibrations. As the results, it was found there exist possibility of resonance between gear mesh frequencies and lateral vibration mode of the transmission shaft during the third shifting mode operation. In order to avoid this resonance, we proposed changing the arrangement of gears on the transmission shaft. The measured vibration levels of the improved gear box were dramatically reduced. These results may be helpful to design a machine tool gear box with low noise and vibration.

• 오토저널
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• 제14권2호
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• pp.44-53
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• 1992

Automotive transmission is the principle component of vehicle driving system, which transmits the adjusted engine power. The automation of transmission arises from the annoyance of transmission operation such as the frequent stop/start of vehicle and the shifting transients. The study on the optimal shifting condition for the automation of transmission needs the investigation of shifting transients. However, the dynamic modeling theory during transient period is not well-established. In this study, the techniques of dynamic modeling for the power transmission system with Merrite-Wilson gear train are presented. To predict the shifting transients, a driving simulation program is developed, and the results of the analysis are cross-checked in the field test.

• Journal of Advanced Marine Engineering and Technology
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• 제24권6호
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• pp.155-163
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• 2000

A technology of full time four wheel drive(4WD) vehicle has been improved greatly, and the market share of full time 4WD has been extended steadily in recent days. The transfer case is an essential element in the 4WD automobile. In this paper, the details of electronically controlled transfer case is described. In order to achieve easy shifting, the shifting, the developed system automate the conversion of "$4\times2\longleftrightarrow4\times4(H)\longleftrightarrow4\times4(L)$". Furthmore, this system employs an chain drive type instead of gear drive type for drive type and synchromesh type instead of constant-mesh type for gear mesh type. Therefore, the developed transfer case is accomplished light-weight, low noise, and compact.d compact.

• 동력기계공학회지
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• 제17권5호
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• pp.128-137
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• 2013

Modern transmission technologies such as automated manual transmission(AMT) and dual clutch transmission(DCT) are interested to all manufactures due to their fuel efficiency and driver's convenience, especially in a hybrid system. AMT has advantages in that they have a high efficiency of manual transmissions(MT) and offer operation convenience similar to automatic transmissions(AT), but it has some disadvantages in that they have torque gap during gear shift and shift time. To reduce disadvantages, it is necessary to evaluate errors and characteristics as a developing simulation model before experimental verification. The purpose of this study is to develop virtual components and simulate the transient response of AMT. A dynamic AMT model and a control logic for an integrated vehicle model have been developed using Matlab/Simulink as a simulation platform. In this paper, the clutch model to describe the stick-slip transition mode and the transmission model to describe the neutral gear shifting is introduced and compared with each other.

• 한국기계가공학회지
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• 제18권11호
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• pp.24-34
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• 2019

An automotive automatic transmission is a popular power-transmitting device in passenger vehicles, as it provides various speed ratios for diverse driving conditions with easy manipulation and smooth gear shifting. The transmission is mainly composed of input and output shafts, planetary gear sets, brakes/clutches, and housing, and it yields multiple forward gears and one reverse gear by actuating the shifting devices of the brakes and clutches. In developing a new transmission, kinematic configurations of a transmission, which presents a brief structure and actuation schemes for speed ratios, need to be checked to determine if the structure can be assembled in a layout. It is impossible for a transmission concept having any interference in connecting main components to be developed further in the design process, since connection interference leads to failure of a layout design in the 2-D plane. In this research, an analysis of the assemblability of a front-wheel drive automatic transmission is carried out on an example concept design by applying the vertex addition algorithm based on graph theory.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2012년도 추계학술대회 논문집
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• pp.488-489
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• 2012

• 대한기계학회논문집A
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• 제20권10호
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• pp.3142-3151
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• 1996

As plastics shrink when changing from a molten to a solid state, mold cavities must by made larger than the product specification, In making molded gears, the teeth in the cavity must be carefully compensated for shrinkage so that the teeth of gears will have the correct profile. Two compensation methods are widely used in the cavity design. One is the compensation of a module and the other is the modification of a pressure angle and profile shifting coefficient. These methods, however, do not provide a gear cavity with all disign parameters for gears and several parameters are determined by experience. In this paper, the new design technique, namely the compensation method of design parameters, was proposed , which is based on the three kinds of shrinkage rates obtained from the measuring data of the prototype of molded gears. Using the shrinkage rates in the tip circle, tooth heigth and tooth thickness, we calculate the whole design parameters of a gear cavity. Thus, the gear cavity is considered as a complete gear with the compensated module, pressure angle, profile shifting coefficient, clearance coefficient and back lash amount so that the formula of gears can be applied to the cavity design effectively. Experimental results show that more precision molded gears can be made by using the proposed design method.