Mitsubishi Denki Kabushiki Kaisha

Mitsubishi Denki K.k.

Akihiro Nakagawa

Akira Demizu

Toshiki Kuroda

Masanori Inada

Jun Suzumura

Ryoji Nishiyama

A drive method for a brushless motor and a drive control apparatus therefor, in which control parameters are calculated by revolution number control means or motor current control means in accordance with the deviation between a target value and an actual value, a manipulated variable is computed by conduction phase control means on the basis of the calculated control parameters, an advance angle magnitude is computed from the relationship between a manipulated variable and an advance angle magnitude as designed and created beforehand, on the basis of the computed manipulated variable, and the value of a conduction phase angle of a drive circuit as designed on the basis of a rotation position signal or a motor current signal is corrected using the information of the computed advance angle magnitude.

Drive method for brushless motor and drive control apparatus therefor

A drive method for a brushless motor and a drive control apparatus therefor, in which control parameters are calculated by motor current control means (in FIG.) in accordance with the deviation between a target motor current value and an actual motor current value, a manipulated variable is computed by phase control means () on the basis of the calculated control parameters, an advance angle magnitude is computed from the relationship between a manipulated variable and an advance angle magnitude as designed and created beforehand, on the basis of the computed manipulated variable, and the value of the conduction phase angle of a drive circuit () as set on the basis of a motor current signal is corrected with the information of the computed advance angle magnitude.

A misfire detecting apparatus for an internal combustion engine in which erroneous decision as to occurrence of misfire is prevented regardless of engine rotation speed variation pattern. The apparatus includes a crank angle sensor (4) mounted on a crank shaft (2) of the internal combustion engine (1) for generating a crank angle signal (.theta.) for every predetermined crank angle of the engine (1), a rotation-speed variation detector (21, 22) for detecting variation in rotation of the internal combustion engine (1) on the basis of the crank angle signal (.theta.), a misfire decision means (23A) for determining occurrence of misfire on the basis of the variation in the rotation speed of the engine (1), a rotation-speed variation pattern decision means (41) for deciding whether or not a rotation-speed variation pattern representing the variation of the rotation speed of the engine matches with a predetermined pattern which indicates resonance with a driving system operatively coupled to the internal combustion engine, and a misfire decision inhibit means (42) for invalidating the misfire decision means (23A) when matching is found between the rotation-speed variation pattern and the predetermined pattern.

Misfire detecting method and apparatus for an internal combustion engine

A self-diagnosis apparatus diagnoses an exhaust gas recirculating system of an internal combustion engine based on an amount of change in an intake pressure in a intake pipe which is caused by opening of an exhaust gas recirculation control valve which is disposed in a exhaust gas recirculating passage communicating between the intake pipe and an exhaust pipe. The apparatus determines whether or not a difference in engine speeds and/or amounts of engine control as measured before and after the exhaust gas recirculation control valve is opened exceeds a predetermined value, and executes the diagnosis when the difference in the engine speeds is not greater than a predetermined value and/or when the difference in the engine control amounts is not greater than a predetermined value.

Self-diagnosis apparatus for exhaust gas recirculating system

A misfiring sensing apparatus for an internal combustion engine measures the length of time required for two periods during the operation of an engine, each of the periods corresponding to a predetermined number of degrees of rotation of the crankshaft of the engine and corresponding to prescribed positions of the pistons of the engine. The two periods are selected so that the ratio of the lengths of the two periods will change when one of the cylinders of the engine is misfiring. Misfiring is detected based on the value of the ratio. In one form of the invention, misfiring is sensed by comparing the ratio with a reference value. In another form of the invention, the ratio is used to calculate a value indicative of the current angular acceleration of the crankshaft of the engine, and the calculated value is compared with a reference value to determine whether knocking is taking place.

Misfiring sensing apparatus

A method and apparatus capable of detecting the occurrence of misfiring in an internal combustion engine with high reliability over a wide engine operation range with a simplified structure. Starting from a fact that an engine acceleration changes in dependence upon combustion states in the engine cylinders, a ratio between two periods before and after a predetermined crank angle reference position is successively determined. An angular acceleration of the crankshaft is then determined on the basis of a difference between a current ratio and a preceding ratio for each cylinder. Subsequently, a change in the crankshaft acceleration is determined for comparison with a predetermined value at every ignition timing for each cylinder. If the change exceeds the predetermined value, it is determined the occurrence of misfiring. The method can be carried out by making use of only an output signal of a crank angle sensor which is usually utilized for ignition timing control of the engine.

Misfiring detecting method and apparatus

In a misfire detecting device for an internal combustion engine, a crank angle detector detects the crank angle of the engine, a speed detector detects the speed of the engine from the crank angle thus detected, a load detector detects the load of the engine from the speed thus detected; and a misfire detector detects the misfire rate of the engine from the load thus detected, and outputs a misfire detection signal when the misfire rate thus detected exceeds a misfire rate determining value set according to a certain amount of load.

Misfire detecting device for internal combustion engine

An apparatus for defecting occurrence of misfiring in an internal combustion engine with improved reliability. A change in an angular velocity of a crankshaft of the engine and a change in the output of an air/fuel ratio sensor are monitored. Only when both changes indicate occurrence of misfiring independently from each other, it is decided that misfiring in the cylinder has taken place. Reliability in misfiring detection is improved by using the results obtained through at least two mutually different types of misfiring detections.

Misfiring detecting apparatus for an internal combustion device

A misfire detecting device of an internal combustion engine comprises a pressure detector(s) for detecting an inner cylinder pressure of the engine, a crank angle detector for detecting a crank angle, and a misfire detector for detecting a misfire based on signals from the pressure detector and the crank angle detector. The misfire detector judges that the engine is under a misfire, when a comparison is made between a first integrated value of an indicated inner cylinder pressure before a predetermined crank angle of a combustion cycle of the engine and a second integrated value of the indicated inner cylinder pressure after the predetermined crank angle, and when there is a difference between the first value and the second value by less than a predetermined value.

Misfire detecting device of an internal combustion engine

A trouble diagnosis appartus comprises a cylinder internal pressure change detecting circuit to detect a change in the inner pressure of the cylinders of an internal combustion engine, a differentiation circuit to effect differentiation of an output signal outputted from the cylinder internal pressure change detecting circuit and a judging circuit to judge the internal combustion engine being faulty when a change quantity of output signal of the differentiation circuit is a predetermined value or lower.

Trouble diagnosis apparatus for an internal combustion engine

A misfire detecting device for an internal combustion engine comprises an inner cylinder pressure detector, a crank angle detector, and a misfire detector for determining that a misfire has occurred when the inner cylinder pressure at a predetermined crank angle after top dead center in an engine combustion cycle is below a predetermined value.

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Himeji, Japan

Akihiro Nakagawa