Honda Giken Kogyo Kabushiki Kaisha

Honda Motor Co., Ltd.

Yoshiaki Akimoto

Yukio Miyashita

Jiro Takagi

Atsushi Kurauchi

Hirotaka Komatsu

Natsuko Kitamura

Masayuki Yoshiiri

Kazuhiko Hirota

Masaki Kanehiro

Yasunari Seki

Yuzuru Koike

Hideo Ueshima

Isao Yahata

Hideaki Miyashita

Yukihiro Noguchi

Makoto Murakami

A frequency spectrum analyzing apparatus for performing a frequency spectrum analysis with respect to a detected value of an operating parameter of an internal combustion engine in synchronism with rotation of the engine, is provided. The operating parameter is sampled at predetermined time intervals, and a sampled value is converted to a digital value. Intensities of first and second elements are calculated with respect to a predetermined number of the sampled values. The first elements and second elements respectively correspond to a plurality of frequency components contained in the detected value, and a phase of the second element differs from a phase of the first element by 90 degrees. Frequency component intensities corresponding to the plurality of frequency components are calculated in synchronism with rotation of the engine, using the first element intensities and the second element intensities. The frequency component intensities are calculated by replacing a part of an integrated value of the first element intensities, and a part of an integrated value of the second element intensities respectively with corresponding preceding calculated values, when an rotational speed of the engine is higher than or equal to a set threshold value.

Frequency spectrum analyzing apparatus

A knocking detecting apparatus for an internal combustion engine, which can more accurately perform the knocking determination based on frequency components of the output signal of the knock sensor, is provided. A frequency spectrum analysis of the knock sensor output signal is performed at predetermined angular intervals of the crankshaft rotation angle. Intensities of a plurality of frequency components obtained by the frequency spectrum analysis are stored as time series data. The time series data of the frequency component intensity are binarized, and it is determined whether or not a knocking has occurred based on the binarized time series data.

Knocking detecting apparatus for internal combustion engine

Pairs of sensors are disposed vertically, each pair of sensors being disposed such that they hold a piston laterally, and those pistons are provided in such a manner as to extend across a water jacket provided so as to surround a cylinder liner defining a cylinder chamber receiving therein the piston. Since sensor accommodating cases extend across the water jacket, the accommodating case can preferably be cooled by cooling water, and the sensors can in turn be cooled via the accommodating cases, whereby the effect of heat from combustion chambers on the sensors can be reduced, thereby making it possible to improve the detection accuracy of the sensors.

Piston behavior analyzing sensor mounting structure and piston behavior analyzing method

Oil passages,for lubricating and cooling a piston pin,are provided in such a manner as to each open to an oil ring groove,of a piston,and to a piston inner side surface,of a piston pin supporting part,at portions in the vicinity of an upper end of a piston-pin hole,through the piston pin supporting part,. The oil passages,are provided diagonally relative to an axis of the piston-pin hole

Oil passage arrangement in a piston

A system for controlling ignition timing of a vehicle internal combustion engine, in which a plurality of sets of ignition timing control characteristics are established in response to the octane numbers of different kinds of fuel which may intentionally or unintentionally be used in the vehicle. The system infers the octane number of the fuel being used from the occurrence state of knock and selects the set of control characteristics corresponding to the selected fuel octane number, whereafter it determines the ignition timing based on the selected set of control characteristics. The system overcomes the disadvantages of the conventional system, namely that when the set of characteristics for low octane number fuel is misselected when the vehicle is running on high octane number fuel, resulting in unnecessary reduction of output torque, either the conditions under which it is possible to forcibly shift to the set of conditions for high octane number fuel are limited to special ones, specifically to low engine speed operating condition, or if not so limited, the knock which occurs when the forcible shift is carried out causes a shift in the opposite direction, whereby the control experiences undesirable hunting.

Ignition timing control system for internal combustion engine

A knocking control system for an internal combustion engine with inlet valves and exhaust valves having valve timing thereof controlled depending on operating conditions of the engine. It is determined whether or not knocking has occurred in the engine on the basis of a detection parameter indicative of knocking and at least one discrimination parameter. The operation of the engine is controlled by the use of at least one control parameter in response to the determination result, so as to eleminate knocking. The values of the discrimination and control parameters are selected in accordance with the actual valve timing. When abnormality in the valve timing control is detected, the valve timing is held at predetermined valve timing irrespective of engine operating conditions, and values of the at least one discriminating parameter and the at least one control parameter are selected, which correspond to the held predetermined valve timing. Alternatively, when abnormality in the valve timing control is detected, the above control of the engine operation is inhibited.

Knocking control system for internal combustion engines

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Wako, Japan

Yoshiaki Akimoto