Pioneer Electronic Corporation

Honda Motor Co., Ltd.

Nippon Telegraph and Telephone Corporation

Hideaki Morikawa

Yasuo Gan

Yoichi Ishibashi

Takashi Oyaba

Naobumi Kanemaki

Shunsuke Kitawaki

Koushiro Kogure

Takashi Ooyaba

To avoid the generation of a pumping loss, a communication passage is formed as a bypass passage between an exhaust port and a combustion chamber in an internal combustion engine. The communication passage is provided with a one-way valve as an exhaust gas return amount adjustment means. The one-way valve includes a spring member having a spring constant set to the value such that a valve body does not displace toward the combustion chamber under the pressure of the exhaust gas in the exhaust port. An opening degree of the one-way valve is autonomously adjusted depending on the amount of air introduced from an intake manifold when the pressure within the combustion chamber becomes negative in the intake stroke. Then inside of the combustion chamber is kept at substantially the atmospheric pressure with the exhaust gas returned to the combustion chamber via the communication passage and the aforementioned air.

Load control mechanism for internal combustion engine

An engineprovided with a fuel injection mechanism (a fuel injection systemand an FI control unit) that supplies fuel of arbitrary quantity into a combustion chamberand a variable valve mechanism (an intake valve, an exhaust valve, hydraulic electromagnetic valve drive unitsand a valve event control unit) that varies the ratio of burned gas and air-fuel mixture in the combustion chamberfor combusting fuel by compression self ignition, is controlled so that a deviation &#x394;T between combustion initiation temperature and peak temperature after combustion in the combustion chamberis converged in a predetermined range.

Control method of compression self ignition internal combustion engine

A horn shaped baffle is provided in the front of a loudspeaker. Escape holes are formed in the horn shaped baffle so as to emit sound waves deviated from the axis of the loudspeaker. A sound absorptive panel is provided on the outside of the baffle so as to cover the holes.

Loudspeaker

A speaker system comprises an acoustic panel. The acoustic panel is constructed of a plurality of thin plate-like sound absorbing panels provided close to the loudspeaker and arranged such that major surfaces thereof are disposed with a predetermined space therebetween so that the front space of the loudspeaker is opened for guiding a sound wave forwardly to radiate along the surface of the panels, while components of the sound wave having a radiation direction oblique to the major central axis of the sound absorbing panels are attenuated due to propagation through the sound absorbing panels. The sound absorbing panels are made of a porous sound absorbing material in which metal powders of Al, Ni, Cu, and others are sintered. In the case where one side of the acoustic panel is opened, it is preferable to provide a sound absorbing material at least at that opening and to further enclose the periphery of the sound absorbing material with a sound insulating material.

Speaker system having directivity

A speaker system comprises a pair of speakers for a higher frequency range and a pair of speakers for a lower frequency range. The speakers for the lower range are disposed with a space d.sub.1 equal to the wavelength .lambda..sub.c of a division frequency f.sub.c of a reproduction frequency range, and speakers for the higher range are disposed with a space d.sub.2 =d.sub.1 /4 to d.sub.1 /2 in the middle of the lower frequency speakers. Another speaker system comprises a speaker for reproducing signals in a lower frequency range of a reproduction frequency range to be reproduced, and a speaker for reproducing a higher frequency range of the frequency range, wherein a sound path dividing construction is provided for dividing the sound path of each of the speakers into two paths to provide openings for the lower frequency range and the higher frequency range. The openings for the lower frequency range are disposed with a space d.sub.1 therebetween while the openings for the higher frequency range are disposed with a space d.sub.2 therebetween, where d.sub.1 =.lambda..sub.c .+-.50% and d.sub. 2 =d.sub.1 /4 to d.sub.1 /2.

Growing community of inventors

Saitama, Japan

Hideaki Morikawa