A gap-type capacitive displacement transducer is adopted for measuring the elastic deformation of a tool-workpiece interface in cold simple upsetting. A 1-mm-diameter hole is bored straight to the depth of about 1.2 mm from the inside surface of a die and a steel pin is placed in the hole for detecting vertical displacements near the die-workpiece interface. The pin is pushed inward by a spring vertically. The vertical displacement of the die-workpiece interface pushes the detection pin outward. We measure the amount of deformation of the die from the variation of the gap between the head of the extruded pin and the head of the capacitive transducer. Gap-type capacitive displacement transducer has the advantage of high resolution, low noise, and excellent stability. We use 8 transducers in the experiment to measure displacement distribution simultaneously. This measurement system is applied to measure the die deformation in cold simple upsetting of pure aluminum billets. In conclusion, we demonstrate that this measurement method is useful for measuring die deformation in forging.

A wheelchair is a vehicle that often causes accidents due to unintentional backward movement. For example, an operator of the wheelchair falls due to loss of propulsive force on an uphill slope. To prevent unintended rolling backward, a oneway clutch based on a complex mechanism has been installed in wheelchairs. However, such measures have problems such as increasing the complexity of the wheelchair operation method and increasing the number of parts. We propose a solution to this problem by creating a new one-way clutch based on a simple mechanism and installing it on a wheelchair. The clutch utilizes a self-locking gear train with three spur gears. The self-locking of the gear train requires the three gears to be placed in specific positions, and the method for defining these positions has not been fully understood. To solve this problem, we developed a theoretical model in which the gears are regarded as friction rollers, and derived a simple conditional equation for determining this arrangement. Using this equation, we designed a one-way clutch and installed it in an actual wheelchair.

Tread patterns are grooves or notches carved into shoe soles and tire surfaces. They significantly affect physical performance, such as ease of running and stopping. In addition, the complexity of their design and the fact that they form the external shape of a product also demands their visual beauty. This study proposes a multi-objective optimal design method that simultaneously considers functionality and aesthetics. First, the dataset of aesthetic evaluation is prepared based on the semantic differential method, and the sensory evaluation model is constructed using a convolutional neural network. This enables the quantitative aesthetic evaluation of each pattern generated in the optimization process. The physical performance indices are evaluated using the finite elements method. Then we solve multi-objective optimization problems using a data-driven topology design method with the physical and sensory indices as objective functions. Typical designs are extracted by deep clustering of the obtained patterns, and various design candidates are suggested to the designer. We apply the proposed method to an example problem about tire tread patterns to investigate its validity and effectiveness. The results demonstrate that the proposed method can generate a wide variety of aesthetic patterns with compromising functionality.