Abstract: A noise reduction apparatus includes an intake passage forming member defining an intake passage, a resonator, and a vibration film. Intake air drawn into a combustion chamber of an internal combustion engine flows through the intake passage. The resonator has an inner volume part branching from the intake passage. The vibration film is placed to separate the intake passage from the inner volume part. The vibration film is vibrated by a sound pressure of a sound that is generated in the combustion chamber and that propagates through the intake passage. The vibration film has a projection part, which separates the vibration film into an inner vibration film part and an outer vibration film part.

Abstract: A butterfly valve restricts flow passage areas of a purge passage and a blow-by gas passage by the same degree. A first pressure sensor detects variation in pressure of the purge gas, which is generated by the butterfly valve. A second pressure sensor detects variation in pressure of the blow-by gas, which is generated by the butterfly valve. Since a fuel vapor concentration of the blow-by gas is lower than that of the purge gas, the blow-by gas can be treated as air of 100%. Hence, the fuel vapor concentration is calculated based on the variations in pressure detected by the first pressure sensor and the second pressure sensor.

Abstract: A butterfly valve restricts flow passage areas of a purge passage and a blow-by gas passage by the same degree. A first pressure sensor detects variation in pressure of the purge gas, which is generated by the butterfly valve. A second pressure sensor detects variation in pressure of the blow-by gas, which is generated by the butterfly valve. Since a fuel vapor concentration of the blow-by gas is lower than that of the purge gas, the blow-by gas can be treated as air of 100%. Hence, the fuel vapor concentration is calculated based on the variations in pressure detected by the first pressure sensor and the second pressure sensor.

Abstract: A resonator is connected with an intake air pipe and forms a resonant chamber therein. The resonator includes a diaphragm, which is generally planar and is disposed between an air passage of the intake air pipe and the resonant chamber. The diaphragm forms multiple oscillation sections, which have different eigenfrequencies, respectively.

Abstract: A three-dimensional image recording/reproduction method, and an apparatus therefor. An opaque light control panel having a large number of fine light transmission portions at predetermined locations is placed between an object and a recording panel, and a large number of small images of the object are formed on the recording panel through the minute light transmission portions. The small images recorded on an picture display panel are reproduced to display the three-dimensional image of the object. An opaque panel having an opening is disposed around the object or between the object and the light control panel, and a conversion operation is carried out so as to reverse the small image of the opening formed on the recording panel point-symmetrically by 180 degrees with respect to a point, at which a line connecting the center of the opening of the opaque panel to each fine light transmission portion, being the point of symmetry. The cubic image is formed in front of the light control panel.

Abstract: A method of, and an apparatus for extruding a billet of a light metal alloy, wherein the billet has an outer diameter smaller than a maximum configuration width and larger than a minimum configuration width of the die hole at its entry side. The billet is pressurized and extruded by a stem to form a preshaped portion which is larger than the entry side configuration of the die hole, at a frontal end portion of the billet near an entry portion of the die hole. The preshaped portion of the billet is subsequently shaped by the die hole into an extruded shape corresponding to the cross-sectional shape of the die hole and of parts formed from the extruded billet, e.g., of an automobile suspension arm. A reduced resistance and a minimized extrusion pressure upon extrusion of a light metal alloy result from the preshaping of the billet and enable realization of a compact and less expensive arrangement of the production facility.

Abstract: A body frame for a motor bicycle includes a main frame, a head tube provided at a front end of the main frame and down tubes extending rearward from the main frame. The main frame, head tube and down tubes are cast with a light alloy into an integral form of a hollow and thin-wall structure. A production process of the body frame, wherein an integrally-formed core, which is formed into a shape similar to that of the body frame, is hollow and has good permeability. A molten metal is charged into the mold and a vacuum is applied to the interior of the core.

Abstract: A body frame for a motor bicycle includes a main frame, a head tube provided at a front end of the main frame and down tubes extending rearward from the main frame. The main frame, head tube and down tubes are cast with a light alloy into an integral form of a hollow and thin-wall structure. A production process of the body frame, wherein an integrally-formed core, which is formed into a shape similar to that of the body frame, is hollow and has good permability. A molten metal is charged into the mold and a vacuum is applied to the interior of the core. The molten metal is charged into a cavity defined between the core and the molding surface of the mold by a low-pressure casting method, and the molten metal is solidified so as to cast the body frame.

Abstract: A method for washing an impregnated porous workpiece including a step of rotating the impregnated porous workpiece after excessive impregnant has been shaken off, in such a manner that the workpiece is immersed in and comes out of a washing liquid contained in a washing tank, forcibly causing the washing liquid to go in and out of a recessed portion such as a hole bored in the workpiece to thereby dilute and wash away residual impregnant adhering to the inside of the recessed portion.