• 유체기계공업학회:학술대회논문집
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• 2006.08a
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• pp.459-462
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• 2006

In this study, the characteristic of a vane pump of an automative power steering system is numerically analyzed. The vane pump changes the energy level of operation fluid by converting mechanical input power to hydraulic output. To simulate this mechanism, moving mesh technique is adopted. As a result, the flow rate and pressure are obtained by numerical analysis. The flow rate agrees well with the experimental data. Moreover, the variation and oscillation of the pressure around the rotating vane are confirmed. The difference of pressure appears in the vane tip as a result of the flow characteristics. Furthermore, the back flow into the rotor was observed.

• Transactions of the Korean Society of Automotive Engineers
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• v.17 no.1
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• pp.58-63
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• 2009

Flow rate of the power steering oil pump is affected by oil temperature, engine rpm and pressure of pump. In this paper, considering those conditions, approximate model expressed by flow rate characteristics between hydraulic power steering oil pump and steering gear is proposed. Oil pump displacement is considered to be 9.6cc/rev. which is adapted to mid size car. Flow rate of the oil pump is predicted from the proposed model and compared with experimental data. And catch-up is also predicted in each steering wheel speed and is compared with experimental results.

• The KSFM Journal of Fluid Machinery
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• v.10 no.6
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• pp.24-31
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• 2007

In the present study, the effects of the design factors and operating conditions on flow characteristics of a vane pump for the automotive power steering system has been analyzed numerically. An unsteady moving mesh technique with cell expansion/contraction method is used to simulate the rotation of vanes with respect to stationary inlet and outlet. As a result, the flow characteristics of the flow rate and pressure rise across the vane pump were obtained. The numerical analyses for the various design factors such as number of vanes and thickness between the rotor and camring and for various operating conditions such as rotational speed and pressure difference between inlet and outlet were extensively performed. And the results were discussed in the paper.

• Journal of the KSME
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• v.33 no.10
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• pp.902-911
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• 1993

반능동 현가 시스템의 장점은 능동 및 수동 현가 시스템의 장점을 모두 갖고 있다는 것이다. 즉, 반능동 시스템은 수동 현가장치에 비해 우수한 성능을 제공하면서 대형 액츄에이터나 큰 동력 원을 필요로 하지 않는다. 지금까지는 승차감 및 조향성능을 향상시키기 위한 능동 및 반능동 현가시스템에 관한 연구가 많이 이루어졌으나, 능동 또는 반능동 현가시스템을 이용하여 대형 차량의 주행 안정성을 향상시키고, 대형차량에 의해 주로 발생하는 도로의 파손을 줄이면서 차 량의 수송능력을 향상시키는 연구는 최근에 유럽과 미국의 대형트럭 제조업체와 정부 주도로 활발하게 진행되고 있다. 그러므로 반능동 현가시스템에 의한 대형 트럭의 성능 향상 가능성 및 연구 개발도 승용차용 능동 및 반능동 현가시스템과 함께 앞으로의 주 연구 과제이다. 이글에 서는 우선 가변 댐퍼 및 반능동 현가시스템의 기본 원리를 설명하고, 반능동 현가시스템의 Bilinear Model, 제어방법에 대하여 언급한 후, 컴퓨터 모의 실험결과를 통하여 반능동 현가시 스템에 의한 차량의 동적 성능 향상을 두 가지 측면, 즉, 승용차와 대형트럭의 측면에서 언급될 것이다.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.11a
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• pp.313.1-313
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• 2002

A high pressure hose having tuning cables, called Resonator hose' is frequently used to attenuate pressure ripple generated by the pump fur reducing the vehicle interior noise. A number of studies have been conducted on the resonator hose and its analytical models. However, there are few studies which deal with the influence of resonator hose on vehicle interior noise because the most of studies focused on transmission loss of the resonator hose. (omitted)

• Journal of Biosystems Engineering
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• v.20 no.3
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• pp.226-235
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• 1995

An unmanned speed sprayer was developed using a remote control and an inductive cable guidance systems to protect operators and environment from hazardous pesticides. The sprayer consists of a remote control system, an induction system, obstacle detectors, control actuators and an one-chip microcomputer. The sprayer can be operated by the induction guidance and/or remote control. The following summarize characteristics of the developed speed sprayer. 1) Both the remote control and the induction guidance operation were possible with the developed speed sprayer. 2) Sixteen functions of the forwarding, backing, halting, steering, 3-way valve for nozzles and fan operating etc. were utilized on the remote control system. 3) It was concluded that the DTMF method, having less transmitting error, performed better than the FSK method for an agricultural remote controller. A radio station may be necessary. 4) The digital inductive guidance system, consisting of five low-impedance detection coils and a window comparator circuit, performed better than the analog detecting system, guiding route using inductive voltage differential from tow detection coils.

• The KSFM Journal of Fluid Machinery
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• v.10 no.1 s.40
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• pp.34-40
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• 2007

In this study, the characteristic of a vane pump of automotive power steering system is numerically analyzed. The vane pump changes the energy level of operation fluid by converting mechanical input power to hydraulic output. To simulate this mechanism, moving mesh technique is adopted. As a result, the flow rate and pressure are obtained by numerical analysis. The flow rate agrees well with the experimental data. Moreover, the variation and oscillation of the pressure around the rotating vane are observed. As a result of flow characteristics, The difference of pressure between both side of vane tip causes the back flow into the rotor. As the rotational velocity increases, the flow rate at the outlet and the pressure in the vane tip rises with higher amplitude of oscillation. In order to reducing the oscillation, the design of devices for decreasing the cross-area of the outlet part and returning the flow from the outlet to the inlet is required.

• Transactions of the Korean Society of Automotive Engineers
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• v.10 no.5
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• pp.199-205
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• 2002

The scale of repair parts market reached 0.1 billion won. Above all, it is remarkable that the automotive insurance business world is paying f3r 40 ~5o% of the whole repair cost. The repair parts consist of a genuine parts, non-genuine parts, recycling used parts. It is the recent trend that recycled parts are more popular than the genuine parts f3r repairing crashed cars due to the cost. Performance of recycled continuous velocity(CV) joints and power steering(PS) gear box as replacement parts was tested and analysed in this study. To examine the durability of the recycled parts, the replaced CV joints and PS gear box after repair were tested and analysed periodically. The results were showed that basic performance of the recycled parts was normal. However the ball cage of CV joints was more frequently damaged than genuine parts. We concluded that a test standard and amendment of related laws for recycled parts is required to get a safe and durable parts.

• Transactions of the Korean Society of Automotive Engineers
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• v.13 no.4
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• pp.190-196
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• 2005

The power steering hose assembly is usually manufactured through the swaging process, which is conducted to connect a hose with metal fittings. In this process the hose is inserted into metal components, the sleeve and the nipple, and compressed in the radial direction by the jaws to clamp the hose with metal components. In case that the clamping force is small, the oil in the hose can leak locally under the severe operating conditions. To confirm the clamping force requirements, the measurement of separation force in longitudinal direction of the hose is usually performed. In this study, the swaging process of a hose is simulated with the finite element method, to investigate the effect of friction coefficient on the separation fDrce. The results interpretations are ffcused on the inner rubber component, and also a formula is proposed to estimate the separation farces with respect to friction coefficients.

• Journal of Korean Society of Forest Science
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• v.100 no.2
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• pp.154-164
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• 2011

This study was conducted to develop the semi-crawler type mini-forwarder that can be operated comfortable small-scale logging operation in the steep terrain and also used at a variety of operations such as the civil work in erosion control and forest-road. Considering the minimum turning radius and the width of forest operation road, the total length, width and loading capacity of the semi-crawler type mini-forwarder is 5,750 mm, 1,900 mm and $2.5m^{3}$, respectively. The maximum engine power is 96ps at 3600 rpm. Selected hydraulic pumps are consists of two main pumps and two sub-main pumps. Main hydraulic pumps are utilized to running motor of the front wheel and rear crawler. Sub-main pumps are utilized to the actuation parts such as steering, crane, out-rigger and dump cylinder. The transmission was adapted as the HST (Hydro-Static Transmission) system. The driving parts are designed and manufactured as the front wheel type and the rear crawler type. The steering type was manufactured as the ackerman type. Driving control parts type was designed and manufactured as driver's seat type of normal cars. It is also attached on auxiliary equipments such as winch, log grapple and out-rigger. The traveling speed of the semi-crawler type mini-forwarder in forest road was 5.3 km/hr to 7.7 km/hr.