• Transactions of the Korean Society of Mechanical Engineers A
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• v.31 no.9
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• pp.934-942
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• 2007

In this study, the characteristics of the load-sensitive hydraulic control system for closed center type of a wheel loader were analyzed using developed analysis program based on Amesim tool. From the parametric analysis, the effects of each factor were revealed. Through the simulation with varying parameters, the system parameter effects on the controllable region and the pump pressure and load pressure variations were studied. The results were compared with the experimental ones. The results and discussions of the present paper could aid in the design of a load-sensitive hydraulic control system for closed center type.

• Proceedings of the KSME Conference
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• 2000.04a
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• pp.873-878
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• 2000

Semiconductor packaging technology is changed rapidly according to the trends of the micro miniaturization of multimedia and information equipment. For I/O limitation and fine pitch limitation, DIP and SOP/QFP are replaced by BGA/CSP. This is one of the surface mount technology(SMT). Solder ball is bumped n the die pad and connected onto mounting board. In ball bump formation, vacuum suction type ball alignment process is widely used, However this type has some problems such as ionization, static electricity and difficulty of fifo(first-input first-out) of solder balls. Seesaw type is reducing these problems and has a structural simplicity and economic efficiency. Ball cartridge velocity and ball aligned plate angle are Important variables to improve the ball alignment Process. In this paper, seesaw-type CSP solder ball loader is developed and the optimal velocity and plate angle are proposed.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.18 no.12
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• pp.67-72
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• 2019

In manufacturing sites that process and produce parts in large quantities for the automotive and electronics industries, users require the reducing of costs and shortened delivery times. To meet these demands, an increase in the number of processes and an decrease in assembly times need to be addressed. Gantry loaders currently on the market in Korea are mostly used for processing lightweight and simple shapes and are not suitable for conveying and processing complex shapes such as automobile engines and aircraft parts. This makes it difficult to mount the material in place. This study aims to smoothen the transportation of complex shapes through the development of jigs and various approaches in the installation of the feed shaft by researching the gantry loader system for transporting multiple materials with complex shapes.

• Transactions of The Korea Fluid Power Systems Society
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• v.4 no.2
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• pp.7-20
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• 2007

TCU is a shift controller far automatic transmission of which major functions are to determine the shift point and manage the shifting process based on the various input signals. As the recent digital control technologies advance, it plays a key-role to improve a transmission performance and its algorithm becomes more complicated. This paper describes the development of transmission simulator fur wheel loader that enables a TCU for normal stand-alone operation by the real-time emulation of TCU interface signals. It can be utilized for the analysis of shift control algorithm implemented in a commercial TCU as well as for the development of brand new TCU.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.05a
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• pp.1218-1222
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• 2006

The bolts fixing the valve cover to the engine were often reported to be failed in a wheel loader model. Recently this failures were continually repeated in the specified equipment. In order to identify the fatigue fractures of the bolts, various vibration tests were carried out. From these tests, it was found out that the failure was due to the resonance between the excitation force of engine and the transverse mode of engine valve cover. So, the several modifications for the bolts were considered to avoid the resonance. Finally, the bolt failure problem was clearly resolved.

• Cement
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• s.47
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• pp.31-37
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• 1972

• 제어로봇시스템학회:학술대회논문집
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• 2002.10a
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• pp.53.4-53
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• 2002

In this paper, we implemented the FIPA-OS framework bundle and service agent bundle over the OSGi service platform in home-sewer platform. The FIPA-OS is the first open source implementation of the FIPA standards and is a component-based toolkit implemented in Java. The FIPA-OS bundle is composed of two bundles. One is the communication bundle such as RMI, IIOP, HTTP and ACC. Another is the agent loader bundle. Experiments are conducted on the service agent communication and loading by the agent loader bundle, and the proposed bundles are successfully installed, stopped, and uninstalled over the OSGi service platform.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2007.06a
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• pp.129-130
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• 2007

• Transactions of the Korean Society of Mechanical Engineers A
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• v.37 no.11
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• pp.1323-1330
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• 2013

A wheel loader is a type of construction machinery that is capable of performing a variety of tasks, and demands on its functional diversity and structural reliability are growing. A wheel bearing is one of the core components that determine the life of the loader; taper roller bearings are commonly used for this purpose. The lifetime of a bearing is typically calculated based only on its load and revolution speed. The initial preload of a taper roller bearing is a critical factor that directly affects its endurance life. In this study, the relations between the endurance life and preload characteristics including the amount of preload according to the weight, rotational speed, and thermal modification applied to tapered roller bearings are presented. When the temperature is $100^{\circ}C$, an excessive preload condition is expected compared with that at room temperature, and the durable life decreases by 20.3 %.

• The Journal of the Convergence on Culture Technology
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• v.5 no.3
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• pp.263-269
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• 2019

In this study, the characteristics and operation of a multi-purpose loader equipped with various sensors such as a sensor capable of measuring the boom length, an angle sensor capable of measuring the tilt of the left and right sides of the boom and the loader, and a load cell capable of measuring the weight during lifting We have implemented a system that displays related data values. The configuration of the system reads the values from the sensors, sends them to the vehicle controller, and transmits the calculated results of the overturn rate and other important information to the display device using the CANOpen protocol. Also, in the calculation of the overturn ratio, the structure of the multi-purpose loader is similar to that of the crane belonging to the heavy equipment, and the crane overturn rate calculation method is used. Through this study, we can observe the condition of the heavy equipment and recognize the emergency situations such as abalone through the display device.