• Journal of Welding and Joining
• /
• v.34 no.4
• /
• pp.48-54
• /
• 2016

The use of Zn coated steel has increased in the automotive industry due to its excellent corrosion resistance. Conventionally the BIW(body-in-white) structure and the hang-on parts have been made of Zn coated steel and more recently Zn coated steel began to be applied in the chassis parts. During gas metal arc (GMA) welding of the chassis part, lap fillet joint used to be adopted but spatter generation and porosities are most important concerns. In the industrial applications, an intentional joint gap was made to avoid the weld defects but it is not easy to control the size of joint gap. In this research, gas tungsten arc (GTA) is combined with GMA welding where GTA precedes GMA. As pulsed arc was adopted as GMA, GTA was oscillated along the longitudinal direction by pulsing GMA, but the arc oscillation did not disturb the molten droplet transfer of GMA welding. By increasing the distance between GTA and GMA, the length of weld pool increased and porosity could be reduced. Moreover porosity in the welds was fully removed when the distance between two arcs was 15 mm.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.13 no.8
• /
• pp.3326-3333
• /
• 2012

In this paper, an educational simulator of automobile chassis electronic control system was developed. The developed system is composed of three parts, a driving condition control & monitoring system, a chassis electronic system monitoring & analysis system, and a virtual simulator & educational multimedia contents. The driving condition control & monitoring system has a commercial real car simulator, hydraulic equipments for representing driving conditions, and a remote control and monitoring system. In the chassis electronic system monitoring & analysis system, information of various sensors and actuators applied to the system can be monitored by Labview programs. Finally, the suggested virtual simulator and the multimedia with 2D Flash and 3D animations can be used effectively by means of teaching materials.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.20 no.1
• /
• pp.8-13
• /
• 2012

In this paper, Hybrid Electric Vehicle is directly designed and manufactured for base study of HEV's system and Green Car. Foundation design consists of power train design and the frame design. The power train concept includes motor, engine, generator and battery. And the concept of the frame is the single-seat of this self-made HEV. A frame installed in hybrid system contains suspension, steering wheel, seat, accelerating pedal, brake pedal, clutch handle and various chassis parts with bearings. Electromagnetic clutch is equipped to transmit engine power to drive axle. The control algorism make using LabVIEW to control of an engine and a motor depending on drive condition. A parallel type hybrid system is manufactured to control operation of a motor and an engine depending on vehicle speed.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.7 no.6
• /
• pp.106-114
• /
• 1999

Today, one of the most important objective in automobile development is to reduce the weight of automobile . The eventual depletion of petroleum and environmental regulations brought considerable emphasis to this area on increasing fuel efficiency. Conventional intake air-fuel system is very heavy because it is composed of numerous parts. The bulky size caused increase in the amount of metal being used to build automobile chassis and this became a serious weight problem. The size also caused difficulties in optimization of fuel supply system which in turn decreased engine efficiency. Currently , there are efforts to integrate several intake system modules into one. The purpose of this paper is to evaluate the directions of such development.

• International Journal of Automotive Technology
• /
• v.7 no.5
• /
• pp.547-554
• /
• 2006

This paper is concerned with an optimal control suspension system using the preview information of road input based on a quarter car model. The main purpose of the control is to combine good vibration isolation characteristics with improved attitude control. The optimal control law is derived with the use of calculus of variation, consisting of three parts. The first part is a full state feedback term that includes integral control acting on the suspension deflection to ensure zero steady-state deflection in response to static body forces and ramp road inputs. The second part is a feed-forward term which compensates for the body forces when they can be detected, and the third part depends on previewed road input. The performance of the suspension is evaluated in terms of frequency domain characteristics and time responses to ramp road input and cornering forces. The effects of each part of the suspension controller on the system behavior are examined.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.11 no.5
• /
• pp.127-133
• /
• 2003

For the purpose of evaluation the damage repairability of a Frame Type Passenger vehicle which experienced a Low Speed 40% Offset front and rear Crash Test. tests were made according to the RCAR testing procedures. Test results concluded ; (1) The deceleration at C.G(center of gravity) off 6.9∼11.39 was similar to that for the vehicle. The airbag system was found to affect neither the passenger's safety nor the savings of the repairing costs. (2) In order to improve the repairability of the Frame Type Passenger vehicle after collision should be a higher crash performance of the bumper on the RCAR standards.

• Tribology and Lubricants
• /
• v.25 no.4
• /
• pp.261-264
• /
• 2009

Environmental factors affect parts of the automobile. When dust particles are embedded, specially, friction and wear of the rubber-seal in automobile chassis system are increased. Increase in friction and wear leads to weakness of component and reduction of mechanical life. In this study, the wear characteristics of rubber-seal for inflow of dust particles are investigated. Silica($SiO_2$) and alumina($Al_2O_3$) particles are used as a dust particle because these particles are main elements of dust particles. The sliding wear tester are used for investigate the wear characteristics of rubber-seal. If the single dust particle($SiO_2$) is embedded in the rubber-seal component, the influence of dust particle size is more than that of inflow rate on the wear characteristics of rubber-seal. If the mixed dust particles are embedded in the rubber-seal component, the wear rate is increased as the rate of alumina that has a bigger hardness is increased. If the mixed dust particles that have different hardness are embedded in the rubber-seal component, the influence of particle size is more than that of particle hardness.

• Transactions of Materials Processing
• /
• v.19 no.6
• /
• pp.337-343
• /
• 2010

Current need of weight reduction in automotive part increases the application for high strength steel (HSS). The various types of high strength steels have been used to produce chassis part, control arms and trailing arms for weight reduction and increasing of fatigue durability such as dual phase steel (DP) and ferrite bainite steel (FB). But, DP and FB steels have proven to show inferiority in durability as well as press formability. Edge cracking occurred often in flange forming and hole expansion processes is the major failure encountered. This paper discussed the behavior of edge stretchability of high strength steel of DP and FB steels. Experimental works have been conducted to study the effect of punch clearance and burr direction on hole expansion ratio (HER). Also finite element simulation (FEM) has been preformed to clarify the mechanism of flange crack and support the experimental results on HER of DP and FB steels. It was simulated the whole process of blanking process following by hole expansion process and ductile fracture criterion named the modified Cockcroft-Latham model which was used to capture the fracture initiation. From the hole expansion tests and FEM simulation studies it was concluded that ferrite bainite steel showed better stretch-flangeability than dual phase steel. It was attributed to the lower work hardening rate of ferrite bainite steel than dual phase steel at the sheared edge.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2013.10a
• /
• pp.94-98
• /
• 2013

Transfer Path Analysis (TPA) is commonly used, by car makers and parts suppliers, analysis process to root the cause of NVH problems. In general, TPA is an analyzing technique to find the contributing factors of noise/vibration problems, and their transfer path in vehicle. However, not only TPA is used to analyze the source of NVH problems but also is used to predict NVH performance prior to the proto vehicle, or to set the development target for next new vehicle. Automotive parts manufacturing companies have to set NVH performance target when developing new systems just as car makers have NVH target set for new vehicle. Nevertheless, most of components are currently being developed based on subjective evaluation without an objective target. To judge the suitability of using TPA to set NVH target of electric parking brake, this research analyzed the transfer path by setting them in two points of view; Chassis Module and Electric Parking Brake, and comparing the measured value and calculated value. From this result, NVH target of electric parking brake will be approached in level of vehicle, system and component.

• Composites Research
• /
• v.32 no.1
• /
• pp.21-28
• /
• 2019

Recently, according to environmental regulations, the automobile industry has been conducting various research on the use of composite materials to increase fuel efficiency. However, there has not been much research on lightweight chassis components. Therefore, in this research, the purpose of this study is to apply composite materials to the sub-frame of chassis components to achieve equivalent levels of stiffness, strength, NVH performance and 50% lightweight compared to the steel sub-frame. First, the Natural frequency of steel and composite specimens was compared to the damping characteristics of composite materials. Then, in this study, the Lay-up Sequence was derived to maximize the stiffness and strength of the sub-frame by applying composite materials. And this lay-up Sequence is proposed to avoid heat shrinkage due to curing during manufacturing. This process was designed based on a FEM structural analysis, and a Natural frequency and frequency response function graph was confirmed based on a modal analysis. The prototype type composite sub-frame was manufactured based on the design and the F.E.M analysis was verified through a modal experiment. Furthermore, it was fitted to the actual vehicle to verify the natural frequency and the indoor noise vibration response, including idling and road noise. This result was confirmed to be equivalent to the steel sub-frame. Finally, the composite sub-frame weight was confirmed to be about 50% of the steel sub-frame.