• Transactions of the Korean Society of Automotive Engineers
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• v.20 no.2
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• pp.123-134
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• 2012

A typical cooling system of an engine relies on a water pump that circulates the coolant through the system. The pump is typically driven by the crankshaft through a mechanical link with engine starting. In order to reduce the friction and warm-up time of an engine, the clutch-type water pump (CWP) was applied in 2.0 liter diesel vehicle. The clutch-type water pump can force cooling water to supply into an engine by the operation of an electromagnetic clutch equipped as the inner part of pump system. The onset of CWP is decided by temperature of cooling water and engine oil. And, the control logic for an optimal operation of the clutch-type water pump was developed and applied in engine and vehicle tests. In this study, the warm-up time was measured with the conventional water pump and clutch-type water pump in engine tests. And the emission and the fuel consumption were evaluated under NEDC mode in vehicle tests. Also, tests were carried out for the various temperature conditions starting the operation of CWP. From the results of the study, the application of CWP can improve the fuel consumption and $CO_2$ reduction by about 3%.

• Transactions of the Korean Society of Automotive Engineers
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• v.24 no.4
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• pp.480-486
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• 2016

Manufacturers have been applying several technologies that can improve the fuel economy of their cars. The regulated voltage control(RVC) system, is one of those technologies being used in passenger cars. In RVC, the voltage of an alternator is controlled depending on the electrical load demand or battery SOC, although each manufacturer differs from another in terms of detail. RVC can reduce the load of an alternator by consuming the stored energy of a battery and simultaneously generate energy. In this paper, a diesel passenger car equipped with an RVC system was tested under FTP-75 and HWFET modes to evaluate fuel economy as their initial battery SOC(100, 90, 80 and 60 %). The test results showed that the initial SOC affects fuel economy only under the FTP-75 mode. FTP-75 fuel economy of the 60% SOC was 13.2 % lower than the 100 % SOC. Also, the simultaneous consumption of the two energy sources did not appear in 60 % SOC.

• Transactions of the Korean Society of Automotive Engineers
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• v.17 no.1
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• pp.19-23
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• 2009

This paper focuses on vehicle fuel economy improvement using D-Range neutral control of automatic transmission. The system objected to reducing of fuel consumption during idle. Usually, turbine of conventional auto transmission is mechanically linked to wheel during idling condition. Therefore speed ratio of torque converter is zero for that period. This causes needless power loss by the torque converter slip. To improve this inefficiency automobile makers develops electronically-controlled D-range neutral control system. The D-range neutral control system minimizes slip on the torque converter by shifting gear to a neutral position during vehicle stoped with D-range gear position. However there's insufficient study about the effect of D-range neutral control system on vehicle fuel economy. In this paper, researches are performed on effect of D-range neutral control system on vehicle fuel economy by experiment with two different vehicle. And it is also estimated the effect on vehicle fuel economy using computer simulation. As a result, 1.8% of LA-4 mode fuel economy improvement can be achieved in a vehicle by D-range neutral control system.

• Journal of the Institute of Electronics and Information Engineers
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• v.54 no.6
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• pp.117-122
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• 2017

Cabin noise due to the electric powertrain of electrical vehicle may consists of motor noise caused by electrical mismatch and gear noise coming from reduction gearbox. These sound may be considered rather small noise compared to those of internal combustion engine, but without masking effect, the noise can be more annoying for customer. Thus, this paper demonstrates the characteristics of electrical vehicle powertrain noise, and the effect of passive damping material for the noise reduction. The typical motor noise can be affected by the motor torque. Also, it is demonstrated that the reduction gearbox may be a weak point for the noise path compared to the motor housing. With vehicle test, it is shown that the damping patch is more effective for noise reduction with deceleration condition than with acceleration condition.

• Journal of the Korean Society of Marine Environment & Safety
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• v.25 no.7
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• pp.968-973
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• 2019

This study presents the characteristics of a pressure drop and uniformity index for a particulate matter reduction device with a perforated plate and mixer for marine diesel engines. The perforated plate and mixer equipped on the particulate matter reduction device induce an increase of exhaust gas reduction performance by increasing the uniformity index. Whereas, the perforated plate induces pressure drop increases in the particulate matter reduction device. Therefore to calculate the effect of the uniformity index and pressure drop of the perforated plates and mixer, this study combines several cases using five types of perforated plates and one type of mixer. Consequently, these results were analyzed to determine the optimized type and position of the perforated plate and mixer.

• Journal of Institute of Convergence Technology
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• v.2 no.1
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• pp.24-30
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• 2012

In this study, the trucks(2.9-liter) have been developed to use DME as fuel, and performance test of the vehicle's DME engine, power, emissions, fuel economy and vehicle aspects was conducted. For experiments, the fuel system(common-rail injectors and high-pressure pump included) and the engine control logic was developed, and ECU mapping was performed. As a result, the rail pressure from 40MPa to approximately 65% increase compared to the base injector has been confirmed that. Also, the pump discharge flow is 15.5 kg/h when the fuel rail pressure is 400rpm(40 MPa), and the pump discharge flow is 92.1 kg/h when the fuel rail pressure is 2,000rpm(40MPa). The maximum value of full-load torque capability is 25.5kgfm(based on 2,000rpm), and more than 90% compared to the level of the diesel engine were obtained. The DME vehicle was developed in this study, 120 km/h can drive to the stable, and calculated in accordance with the carbon-balance method of fuel consumptions is 5.7 km/L.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2009.10a
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• pp.98-101
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• 2009

Recently, there is use of the vehicle network for vehicle diagnostic method and Increased use of the vehicle protocol such as (CAN(Controller Area Network), MOST, LIN, FlexRay), Distributed control and data about the vehicle are being sought methods for real-time observation and monitoring and trend tends to have gone into this. In this case of automotive diagnostic module in today, there is Primarily to use DLC(Data Link Connector)Connector called self-check terminal. Generally, vehicle Diagnoses to use DLC Connector such as OBD2(On Board Diagnostics) Through Diagnostic Module(scanner). But there limit diagnostic as engine and powertrain part, and not consider user's perspective In this paper, By designing Vehicle diagnostic monitoring system using Ethernet Port, transmit and Receives CAN protocol vehicle data, and implement Easily monitoring system that provide and Diagnoses to provide vehicle's state and information to use PC.

• Journal of the Korean Institute of Gas
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• v.25 no.2
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• pp.28-33
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• 2021

With the recent growing interest in eco-friendly cars, as interest in eco-friendly cars increases, interest and purchase of hydrogen fuel cell vehicles that do not emit pollutants are increasing. Recently, the government is supporting the expansion of hydrogen charging station and localization of core parts according to the government's hydrogen energy dissemination policy. In this study, the flow characteristics of the hydrogen flow control valve were investigated. As the differential pressure increases, the mass flow rate and flow coefficient tend to be different from the volume flow rate. And it was confirmed that it affects the hydrogen temperature due to the nozzle effect in the bottleneck section, and the change in density affects the mass flow rate.

• Korean Journal of Agricultural Science
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• v.46 no.3
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• pp.613-627
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• 2019

The purpose of this study was to design a powertrain for a 78 kW AWD (all wheel drive) electric tractor by analyzing the combination of various reduction gear ratios on a commercial motor using data from actual agricultural work and driving conditions. A load measurement system was constructed to collect data using wheel torque meters, proximity sensors, and a data acquisition system. Field experiments for measuring load data were performed for two environmental driving conditions (on asphalt and soil) and four agricultural operations (plow tillage, rotary tillage, loader operation, and baler operation). The attached implements and gear stages were selected through farmer surveys. The range of the reduction ratio was determined by selecting the minimum reduction ratio needed to satisfy the torque condition required for agricultural operations and the maximum reduction gear ratio to satisfy the maximum travel speed. The minimum reduction gear ratio selected was 57 in consideration of the working load condition and the maximum reduction gear ratio selected was 62 considering the maximum running speed. In the range of the reduction gear ratio 57 - 62, the selected motor satisfied all working torque conditions. As a result, the combination of the selected motor and reduction gear ratio was applicable for satisfying the loads required during agricultural operation and driving operation.

• Journal of Mechanical Science and Technology
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• v.16 no.7
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• pp.882-888
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• 2002

In this paper, an algorithm to increase the shift speed is suggested by increasing the line pressure for a metal belt CVT. In order to control the shift speed, an algorithm to calculate the target shift speed is presented from the modified CVT shift dynamics. In applying the shift speed control algorithm, a criterion is proposed to prevent the excessive hydraulic loss due to the increased line pressure. Simulations are performed based on the dynamic models of the hydraulic control valves, powertrain and the vehicle. It is found from the simulation results that performance of the engine operation can be improved by the faster shift speed, which results in the improved fuel economy by 2% compared with that of the conventional electronic control CVT in spite of the increased hydraulic loss due to the increased line pressure.