Masao Fukushima

Abnormal combustion detection and vibration reduction system

An apparatus and a method for detecting abnormal combustion in an internal combustion engine and an apparatus and a method for controlling vibration caused by abnormal combustion. The apparatus for detecting abnormal combustion includes a unit for detecting the rotation of an internal combustion engine, a unit for calculating rotation angular acceleration on the basis of the detected rotation, a unit for comparing the rotation angular acceleration at the position of a predetermined crank angle in one cycle of the operation of the internal combustion engine with a predetermined reference value, and a unit for judging from the comparison result whether abnormal combustion occurs in the internal combustion engine. The apparatus for reducing vibration caused by abnormal combustion offsets vibration caused by abnormal combustion and vibration of an electric generator to each other by passing a pulse-like field current in the electric generator in response to detection of abnormal combustion to generate vibration torque in the electric generator.

Computation of deflection defocusing in CRT electron beams with three dimensional nonlinear analysis of magnetic fields

An analysis is made of the CRT deflection fields using a finite element method (FEM), by both ignoring and considering the nonlinearity in the yoke materials. The results of the linear and nonlinear analyses are compared with the measured values of the fields when the fields are strong enough to deflect the beams to the screen periphery. These computations show that the linear analysis results deviate considerably from the measurements, especially near the yoke. However, the nonlinear analysis results agree well with the measurements. In addition, the paraxial ray theory is applied to calculate the deflection defocusing of CRT beams. The present paraxial ray theory can be used only when either magnetic or electric field exists: the space charge effect of the electron beam is neglected in the analyses. However, the thermal spread of the beam, electron lens aberrations, and the aberrations in deflection fields are all considered.<<ETX>>

REDUCTION OF AUTOMOBILE BOOMING NOISE USING ENGINE MOUNTINGS THAT HAVE AN AUXILIARY VIBRATING SYSTEM

This paper presents a new concept concerning engine mountings that can reduce engine booming noise by utilizing an additional vector. Booming noise in passenger cars, particularly those with a four-cylinder engine, is caused by exciting forces such as the second harmonic of engine intertial force. The authors have found that exciting forces transmitted from the engine to the body structure through the engine mountings are reduced by adding another vector which cancels out these exciting forces. This new vector can be obtained by using a mass-controlled region of a vibrating system possessing either a single degree of two degrees of freedom. When this optimally designed mechanism is adopted on a small passenger car, booming noise can be significantly reduced.