• Journal of Korean Foot and Ankle Society
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• v.24 no.2
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• pp.98-101
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• 2020

We report on the case of a patient with chronic instability of the ball-and-socket ankle joint. The patient, a 21-year-old male, was diagnosed 10 years previously with chronic instability of the ball-and-socket ankle joint. He underwent Broström procedure and augmentation using a periosteal turn down from the fibula for this chronic instability despite having received conservative treatment since the diagnosis. After the procedure, the clinical symptoms of ankle instability were improved and the patient is being periodically followed-up. We report on this case of using a Broström procedure as a treatment option for patients with instability of the ball-and-socket ankle joint with normal range of foot and normal ankle joint alignment without damage in the joint and cartilage.

• Journal of Korean Foot and Ankle Society
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• v.9 no.2
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• pp.231-233
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• 2005

Ball-and-socket deformity of the ankle joint is a rare entity that is usually associated with inequality of leg length, fibular hyperplasia, coalition of the ankle, and ray deficiency. Etiology is unknown, congenital itself or secondary to congenital conditions in the ankle. Nonunion of medial malleolar is rare in bilateral ball and socket ankle joint without lower leg deformity. We report upon this case, and include brief reviwe of the literature.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2001.10a
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• pp.321-325
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• 2001

This paper describes the basic structure of high-precision warm forging process for ball joint socket. If this research is successfully finished, We expect that productivity improvement, reduction of material cost and machining process, and cost down than conventional warm forging process.

• Transactions of Materials Processing
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• v.16 no.6
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• pp.479-487
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• 2007

Die life is generally estimated taking failure life and wear amount into consideration. In this study, the forging die life was investigated considering both of these two factors. The fatigue life prediction for the die was performed using the stress-life method, i.e. Goodman's and Gerber's equations. The Archard's wear model was used in the wear life simulation. These die life prediction techniques were applied to the die used in the forging process of the socket ball joint of a transportation system. A rigid-plastic finite element analysis for the die forging process of the socket ball was carried out and also the elastic stress analysis for the die set was performed in order to get basic data for the die fatigue life prediction. The wear volume of the die was measured using a 3-dimensional measurement apparatus. The simulation results were relatively in good agreement with the experimental measurements.

• Transactions of Materials Processing
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• v.16 no.2 s.92
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• pp.132-137
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• 2007

A double roll rotary forming equipment is presented in this paper. The equipment is developed for joining the socket with the ball of a concave piston assembly with its geometrical tolerance requirements satisfied. The equipment is composed of a lathe, a double roll system and a roll pressing unit driven by the hydraulic system. The workpiece rotates by spindle chuck of the lathe while the double roll system approaches perpendicularly to the central line of the workpiece. The equipment is successfully applied to precision joining of the ball and the socket fur the concave piston assembly of a high pressure hydraulic pump.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.38 no.7
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• pp.779-784
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• 2014

This study provided the analytical model describing the friction-induced noise in the ball joint system under the edge loading condition. The frictional and conformal contact kinematics between the spherical bearing and the hemispherical socket was derived and the dynamic equations of the perturbed motion were established. The numerical results revealed that the bending modes of the ball joint system can become unstable due to friction, and the axial load and contact stiffness strongly influenced the dynamic instability. In contrast, the tilting angle of the socket was not found to significantly contribute to the dynamic instability of the ball joint.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2013.05a
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• pp.969-970
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• 2013

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2006.05a
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• pp.353-358
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• 2006

A three-dimensional finite element approach to process analysis and design for joining the socket with the ball by a kind of the rotary forging processes is presented in this paper. The rigid-plastic finite element method is employed and its results are used to reduce the number of process design tryouts. The approach is applied to developing a concave piston assembly for a high pressure hydraulic pump. Experiments show that the developed piston assembly satisfies the quality requirement on geometrical tolerance.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.16 no.1
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• pp.102-111
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• 2017

An automobile ball joint is the element for connecting the control arm and the knuckle arm, allowing rotational motion. The ball joint consists of the stud, plug, socket, and seat. These components are assembled through the caulking process that consists of plugging and spinning. In the existing research, the pull-out strength and gap stiffness were calculated, but we did not consider the uncertainties due to the numerical analysis and production. In this study, the uncertainties of material property and tolerance are considered to predict the distributions of pull-out strength and gap stiffness. Also, pull-out strength and gap stiffness are predicted as the a distribution rather than one deterministic value. Furthermore, a robust design applying the Taguchi method is suggested.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2003.10b
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• pp.138-142
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• 2003

In this study, to show well favorable characteristics of warm forged material, we compared and analyzed microstructure and mechanical properties of general hot-forged material which finished heat treatment with warm-forged material which was produced by control cooling condition. Along with this, we suggested better direction of control cooling condition to be able to remove heat treatment process while satisfying mechanical properties.