Search Results

1 There are two design challenges of the flow path switching valve in a three-stage variable discharge oil pump. The first is to obtain the required discharge pressure characteristics and the other is to prevent hydraulic vibration. Therefore, we established technologies to determine the shape of the valve and the valve housing that resolve these two challenges. The technology to obtain the required discharge pressure characteristics solves equations that are statically true, such as the equations for the equilibrium of forces and hydraulic orifice. The hydraulic vibration control technology derives a differential equation that takes transient behavior, including oil elasticity and inertia, into account first. Then, the derived equations are converted to a transfer function that indicates the valve behavior according to the input of oil pressure changes. And then the stability criterion is applied to judge whether hydraulic vibration occurs or not.

This paper reports the results of a study into a preview control that uses the displacement of the road surface in front of the vehicle to improve for front and rear actuator responsiveness delays, as well as delays due to calculation, communication, and the like. This study also examined the effect of a preview control using the eActive3 electric active suspension system, which is capable of controlling the roll, pitch, and warp modes of vehicle motion.

Recently, plastic air intake manifold (PAIM) has been adopted into gasoline and diesel engines as standard equipment. The advantages of the PAIM are light mass weight, low cost, high thermal-insulation efficiency and reduction of air pressure loss compared with a metal air intake manifold. However, in order to bring the advantages of the PAIM into play, many issues including static burst, noise and vibration, and so on should be settled in its design process. In this paper, the performance prediction and application example of PAIM are introduced.

It is well known that the self-aligning torque decreases before lateral force is saturated. Focusing on this self-aligning torque change, an estimation method has been developed to detect the friction condition between steered wheels and road surface before the lateral force reaches the friction limit. The lateral grip margin (LGM) is defined based on the self-aligning torque change, which is obtained using the EPS torque and motor current information. The LGM is theoretically analyzed based on the tire model and experimentally verified through the full-scale vehicle test. Moreover, the estimated LGM is applied for the chassis control systems to improve the vehicle dynamics performance.

This paper describes the investigation into the contact pressure and incidental deformation on the contact surface of the piston skirt which comes in contact with the cylinder bore in operation. Focused on the single piston static tests in the first place, relationship between the contact pressure on said skirt and the strains developed inside the skirt, and the relationship between the deformation of skirt face and the strains inside the skirt were studied. Then, the dynamic contact pressure onto the skirt in operation and the amount of deformation were calculated based on the relationships mentioned above using the factor of dynamic strains measured on an engine in operation. The deformation of skirt calculated using said dynamic strains was verified by the direct measurement of the skirt deformation. It was demonstrated that the thrust side of a piston skirt was largely deformed due to enlarged contact pressure caused by the piston slap subsequent to firing top dead center.

As a process that enables the high-speed and continuous forming of lengthy materials with a constant cross-sectional configuration, roll forming offers much higher productivity than the stamping process. However, in case a change must be made to the shape of the cross section, the material must normally be stamped or joined with a part containing a separate shape. This affects productivity, increases the number of pieces, and degrades the material's appearance. This report describes the roll-forming technology that we developed, in which the cross section of the material can be changed gradually. This method adopts a system which uses a movable and rotatable roll-stand that enables high-speed, continuous roll-forming processes.

In this paper, we discuss vehicle directional stability and introduce advanced stability control (ASTC) to stabilize the vehicle during severe cornering. Vehicle behavior in a transient steering condition during severe cornering was analyzed by computer simulation. It was found that applying an external yaw moment makes the vehicle more stable. The effect of controlling the brake force response is also evaluated by simulation to determine the brake actuator response criteria. The actual vehicle test was performed with a pylon slalom using a hydraulic brake actuator. It is verified that the ASTC stabilizes the vehicle for transient steering maneuvers.

We developed amorphous alloy thin films having TCR(temperature coefficient of resistivity) less than ±5 ppm/°C for strain gauge applications. Thin film strain gauges are directly formed on metal substrates insulated with SiO2. These gauges have excellent aging stability at high temperature. The resistivity shows a drift in ▵R/R less than ±0.03% at 120°C in 1000 hours. We developed a pressure sensor and an acceleration sensor with high accuracy and reliability, employing these gauges.