In this paper, the elliptical deformation mechanism of the bearing ring after quenching has been studied by using the theory of “metal-thermal-mechanical” and the multi-field coupling simulation method. It has been mainly considered that it occurred as an experimental phenomenon in the past that, when the bearing ring had been oil quenched, a vapor film had usually formed on its surface, and the breakage and boiling of the vapor film had been observed to be uneven in a circumferential direction. For this reason, based on the phase transition kinetics, several types of heat transfer boundary conditions on the outer surface of bearing rings during oil quenching have been assumed, and the multi-field coupled simulation of the quenching process of bearing rings has been carried out in this paper. According to the simulation results, it could be concluded that when two different heat transfer boundary conditions have been set on the outer surface of the bearing outer ring in the form of orthogonal symmetry, the quenched bearing outer ring would produce elliptical deformation. The above simulation results have been basically verified by comparing the experimental results.

This paper presents a practical human-computer interaction system for wheelchair motion through eye tracking and eye blink detection. In this system, the pupil in the eye image has been extracted after binarization, and the center of the pupil was localized to capture the trajectory of eye movement and determine the direction of eye gaze. Meanwhile, convolutional neural networks for feature extraction and classification of open-eye and closed-eye images have been built, and machine learning was performed by extracting features from multiple individual images of open-eye and closed-eye states for input to the system. As an application of this human-computer interaction control system, experimental validation was carried out on a modified wheelchair and the proposed method proved to be effective and reliable based on the experimental results.

Bearings are usually used at high-speed and high-load conditions, so the bearing sleeve must be able to withstand large contact stress, which requires heat treatment. However, during the quenching process of the bearing sleeve, a vapor film is formed on the surface. Since the vapor film is not uniform along the axial direction during the process of boiling and breaking, it will cause uneven distortion of the bearing sleeve. This uneven distortion will cause the outer ring of the bearing to have elliptical distortion after heat treatment. However, the mechanism of this problem and how to reduce the elliptical distortion has not been completely solved. In this paper, two points on the inner wall and outer wall of the bearing sleeve in the orthogonal direction are measured by means of experiments, and the mechanism of the ellipticity distortion during the quenching process is revealed. Additionally, through its horizontal placement, oblique placement, and vertical placement, the cooling curve and cooling rate curve changes in the process of entering the quenching agent are studied; based on the cooling curve, the heat transfer coefficient of the bearing sleeve during quenching is obtained by the heat transfer equation. Input the heat transfer coefficient into the CAE heat treatment simulation software COSMAP, according to the Metallo-Thermo-Mechanics theory and the method of multi-field coupling, simulating the quenching process of GCr15 and 16MnCr5 materials. By comparison, the ellipticity value of the bearing placed at a 45° angle is smaller than that of the horizontally and vertically placed bearings, with the 16MnCr5 material having the smallest ellipticity value of 0.00016. The simulation results verified the distortion mechanism of the bearing sleeve during the quenching process and how to reduce the solution of elliptical distortion.

Human body damage at the time of the dummy collision and fall using a wheelchair ○石川 耕介(長寿研) 松浦 弘幸(長寿研) 神谷直樹(長寿研) 中野 正博 (純真学園大) 玉川 雅章(九工大) 行正 徹(産医大) 山中 真(純真学園大) 久保田正美(日本自動車研) 松崎照美(長寿研) 近藤理恵(長寿研)