Toyota

About: Toyota is a company organization based out in Safenwil, Switzerland. It is known for research contribution in the topics: Internal combustion engine & Battery (electricity). The organization has 40032 authors who have published 55003 publications receiving 735317 citations. The organization is also known as: Toyota Motor Corporation & Toyota Jidosha KK.

Multiphysics Topology Optimization of Heat Transfer and Fluid Flow Systems

Abstract: This paper is focused on topology optimization of heat transfer and fluid flow systems for multiphysics objectives. Specifically, COMSOL Multiphysics software is coupled with a method of moving asymptotes optimizer in a custom COMSOL / MATLAB script. Various physical process including conduction, convectiondiffusion, and Navier-Stokes flow are considered. To illustrate the method, a standard pure heat conduction problem is first presented in two dimensions followed by an extension of the problem to three dimensions. More complex physics are then examined in the optimization process for a three-terminal heat transfer and fluid flow device. General applications and limitations of the methodology are discussed.

6% Efficiency Cu2ZnSnS4-based thin film solar cells using oxide precursors by open atmosphere type CVD

Abstract: An open atmosphere type chemical vapor deposition (OA-CVD) method is one of the most effective methods for producing functional thin films. Especially, the OA-CVD method is a unique technique which is able to deposit metal oxide thin films by decomposition of vaporized raw materials released through a nozzle onto substrates in the air. Cu2ZnSnS4 (CZTS)-based thin films as absorber layers of thin film solar cells were fabricated by sulfurizing oxide precursor thin films synthesized by the OA-CVD method. Cu(C5H7O2)2, Zn(C5H7O2)2 and Sn(C5H7O2)2 were used as raw materials. The oxide precursor thin films were sulfurized at 520–560 °C in 5 vol% H2S balanced with N2. The formed CZTS-based thin films included oxygen with the composition ratio of O/(S + O) = 0.17–0.27 according to energy dispersive X-ray spectroscopy. The thin film solar cells using the CZTS-based thin films including oxygen [CZT(S,O) films] as the absorber layers were fabricated. The CZT(S,O) thin film solar cell had a stack structure of Al/Al-doped-ZnO/CdS/CZT(S,O)/Mo/soda-lime glass substrate. The efficiency of the CZT(S,O) thin film solar cells was 6.03%, which was the high efficiency in the reported value for CZTS-based thin film solar cells using oxide thin film precursors. It was found that the OA-CVD method is suited to fabricate the absorber layers of thin film solar cells.

Device for detecting deterioration of NOx absorbent

Abstract: A device for detecting deterioration of a NOx absorbent arranged in the exhaust passage of an engine. An O2 sensor generating a current proportional to the air-fuel ratio is arranged in the exhaust passage downstream of the NOx absorbent. When the amount of NOx absorbed in the NOx absorbent is almost zero or after the amount of NOx absorbed in the NOx absorbent is made almost zero, the air-fuel ratio of the air-fuel mixture is changed from lean to rich, and the amount of oxygen stored in the NOx absorbent is detected from the output signal of the O2 sensor at this time. Further, the NOx absorbing capability is found by using this detected oxygen amount.

Synthesis, structure, and conduction mechanism of the lithium superionic conductor Li10+δGe1+δP2−δS12

Abstract: A solid solution of the lithium superionic conductor Li10+δGe1+δP2−δS12 (0 ≤ δ ≤ 0.35) was synthesized and its structure and ionic conductivity were examined. The highest ionic conductivity value of 1.42 × 10−2 S cm−1 was obtained at 300 K with a sintered pellet of the sample having the highest solid solution lithium content of δ = 0.35. The Arrhenius conductivity curves obtained for this material exhibited a gradual change in slope over the temperature range of 193–373 K and the activation energy for ionic conduction decreased from 26 kJ mol−1 below 373 K to 7 kJ mol−1 above 573 K, which is typical of highly ionic conducting solids. The crystal structures of the solid solutions were determined using neutron diffraction, and conduction pathways were visualized through analysis by applying the maximum entropy method. The lithium distribution was found to disperse significantly throughout a one-dimensional conduction pathway as the temperature was increased from 4.8 K to 750 K. In addition, two-dimensional distribution of lithium along the ab plane became apparent at high temperatures, suggesting that the conduction mechanism changes from one-dimensional to three-dimensional with increasing temperature.

Regenerative brake controller for controlling value of regenerative braking torque simulating engine braking torque

Abstract: A regenerative brake controller for controlling a value of regenerative braking torque to simulate engine braking torque. When the shift lever is in the D range, from a first control map which correlates the vehicle speed and the like with target braking torque or target deceleration, the controller reads the target braking torque or target deceleration corresponding to the vehicle speed immediately before the release of the accelerator pedal, and controls the vehicle components on the basis of the read target braking torque or target deceleration such that the regenerative braking torque corresponding to the engine braking torque is produced. When the shift lever is in the engine braking range, the controller detects the shift lever position in this range, determines the target braking torque or target deceleration by referring to the map, and on the basis of the vehicle speed and the like immediately before the release of the accelerator pedal and the shift lever position in the engine braking range, and controls the vehicle components according to the determined target braking torque or target deceleration such that the regenerative braking torque corresponding to the engine braking torque is produced. In connection with the regenerative braking torque corresponding to the engine braking torque, the vehicle drivability can be improved.