Abstract: In a control apparatus, a discharge control unit controls an igniter unit so that a flow of current from a primary coil towards a ground side is blocked, thereby generating a high voltage in a secondary coil, and controls a spark plug so that the spark plug generates electric discharge. An energy input control unit controls an energy input unit so as to input electrical energy to an ignition coil after the start of control of the spark plug by the discharge control unit. A control unit and an abnormality detecting unit detects an abnormality in the igniter unit or the ignition coil based on a first threshold and a first current value that is a value corresponding to a current detected by a current detection circuit at this time, when a first predetermined period elapses after the start of control of the spark plug by the discharge control unit.

Abstract: A maximum value of a discharge current from a capacitor 13, detected by a primary-side current detection means 24 disposed at a grounded end of the capacitor 13, is controlled such as not to exceed a predetermined first control value Y1. The first control value Y1 is derived based on magnetic saturation of a primary winding 3, with the control being performed by controlling the on-off state of an energy injection switching means 20. As a result, magnetic saturation of the primary winding 3 can be prevented, and the reliability of an ignition apparatus which incorporates an energy injection circuit 6 can be increased.

Abstract: A spark plug for an internal combustion engine is provided which includes a housing, a porcelain insulator, a center electrode, and an annular ground electrode. The housing has a small-diameter portion which has a smaller inner diameter and defines a front end thereof. The ground electrode is secured to a front end surface of the small-diameter portion and forms a spark gap between itself and an outer periphery of the center electrode. The ground electrode is smaller in outer diameter than the front end surface of the small-diameter portion. A annular weld which joints the ground electrode and the small-diameter portion is formed in an annular boundary through which the front end surface of the small-diameter portion and the base end surface of the ground electrode face each other. The annular weld continuously and fully extends in a circumferential direction of the ground electrode.

Abstract: A spark plug for an internal combustion engine is provided which includes a housing, a porcelain insulator, a center electrode, and an annular ground electrode. The housing has a small-diameter portion which has a smaller inner diameter and defines a front end thereof. The ground electrode is secured to a front end surface of the small-diameter portion and forms a spark gap between itself and an outer periphery of the center electrode. A pocket is formed between the inner periphery of the housing and a portion of the porcelain insulator which is located closer to a front end of the porcelain insulator than the mounting shoulder is. An air vent extends from outside the ground electrode in a radial direction of the spark plug to the pocket to establish communication between the pocket and the combustion chamber of the internal combustion engine.

Abstract: An ignition apparatus for an internal-combustion engine includes a main ignition CDI circuit that has a main ignition boosting circuit boosting battery voltage and a main ignition capacitor storing electric charge boosted by the main ignition boosting circuit, and that releases the electric charge stored in the main ignition capacitor to a primary coil of an ignition coil to make an ignition plug generate spark discharge, and an energy input circuit that has an energy input boosting circuit boosting battery voltage and an energy input capacitor storing electric charge boosted by the energy input boosting circuit, and that releases the electric charge stored in the energy input capacitor to the primary coil, during a spark discharge started by operation of the main ignition CDI circuit, to make a secondary current flow in the same direction and to a secondary coil of the ignition coil, thereby making spark discharge continue which is started by the operation of the main ignition CDI circuit.

Abstract: According to an ignition device, a first switching unit applies a voltage between electrodes of by spark plug by turning on/off energization from an on-vehicle battery to a primary coil. Further, a second switching unit applies a voltage having the same direction as a spark discharge generated by turning on/off the first switching unit between the electrodes of the spark plug by supplying electrical energy accumulated in a booster circuit into a primary coil. Accordingly, it is possible to greatly reduce a complexity of the on/off switching of the first and second switching units compared to a conventional technology.

Abstract: A spark plug includes a tubular housing, a tubular insulator retained in the housing, a center electrode secured in the insulator with a distal end portion of the center electrode protruding outside the insulator, and an annular ground electrode fixed to a distal end of the housing. The housing has, at the distal end thereof, a small-inner diameter portion that has a smaller inner diameter than other portions of the housing. The annular ground electrode is arranged on a distal end surface of the small-inner diameter portion of the housing so that an inner circumferential surface of the ground electrode faces an outer circumferential surface of the distal end portion of the center electrode through a spark gap formed therebetween. The outer diameter of the ground electrode is less than the outer diameter of the distal end surface of the small-inner diameter portion of the housing.

Abstract: A spark plug includes a tubular housing, a tubular insulator retained in the housing, a center electrode secured in the insulator with a distal end portion of the center electrode protruding outside the insulator, and an annular ground electrode fixed to a distal end of the housing. The housing has, at the distal end thereof, a small-inner diameter portion that has a smaller inner diameter than other portions of the housing. The annular ground electrode is arranged on a distal end surface of the small-inner diameter portion of the housing so that an inner circumferential surface of the ground electrode faces an outer circumferential surface of the distal end portion of the center electrode through a spark gap formed therebetween. The outer diameter of the ground electrode is less than the outer diameter of the distal end surface of the small-inner diameter portion of the housing.

Abstract: It is possible to adjust electromagnetic energy introduced from a low-voltage side of a primary winding 20 of an ignition coil 2 after start discharging to a spark plug 1 from the ignition coil 2 in the correct proportion by threshold-determining either one or both of a primary voltage V1 applied to a primary side of the ignition coil 2 and a secondary current I2 flowing in a secondary side of the ignition coil 2, and by opening and closing a discharging switch 32 disposed between an auxiliary power supply 3 including an energy storage coil 330 and a low-voltage side terminal 201 of the ignition coil 2.

Abstract: An alternating current generation system is provided. In the system, in a rotor, a plurality of detection subject portions are arrayed along a circumferential direction in correspondence to reversal states of the magnetic poles in a plurality of magnetized portions. A detecting unit is disposed opposing the rotor so as to generate an output signal corresponding to passage state of the detection subject portions. A phase control unit outputs, to a power converter, a control signal to perform phase control of switching elements depending on the rotation phase of the rotor, based on the output signal from the detecting unit.

Abstract: An ignition device includes an ignition coil with a primary coil and a secondary coil, a spark plug with center and ground electrodes for discharge therebetween, and a voltage limiting circuit. The voltage limiting circuit limits voltage applied between the electrodes of the spark plug such that the voltage has an absolute value limited within a predetermined voltage limiting value. The voltage limiting value is differentiated from each other in first and second stages. The first stage is defined as a period in which an initial discharge peak ends, the initial discharge peak being initially generated by electric energy. The second stage is defined as a period after the end of the initial discharge peak. The voltage limiting value in the first stage is lower than the voltage limiting value in the second stage.

Abstract: An ignition device includes an ignition coil with a primary coil and a secondary coil, a spark plug with center and ground electrodes for discharge therebeteween, and a voltage limiting circuit. The voltage limiting circuit limits voltage applied between the electrodes of the spark plug such that the voltage has an absolute value limited within a predetermined voltage limiting value. The voltage limiting value is differentiated from each other in first and second stages. The first stage is defined as a period in which an initial discharge peak ends, the initial discharge peak being initially generated by electric energy. The second stage is defined as a period after the end of the initial discharge peak. The voltage limiting value in the first stage is lower than the voltage limiting value in the second stage.

Abstract: In the ignition apparatus for internal combustion engines, the internal combustion engine drives a generator and the generator charges a battery. The battery is connected to a boosting transformer which is connected with a semiconductor switch. The semiconductor switch causes a current to intermittently flow in the primary coil of the boosting transformer from the battery. An intermittence control circuit is connected between the semiconductor switch and the generator and controls the semiconductor switch to turn on and off a plurality of times per revolution of the generator in synchronism with the output of the generator. Thus, the semiconductor switch allows the transformer to generate a high voltage for ignition across the secondary coil. The intermittence control circuit includes an over-rotation preventing capacitor.

Abstract: A magneto generator for a motorcycle engine having a flywheel, in which a plurality of magnets are circumferentially arranged at equal intervals, a certain number of adjacent magnets have the same polarity at their inner surfaces, and N- and S-pole alternately appear at the inner surfaces of the remaining magnets. A stator arranged within the flywheel includes one large pole core and a plurality of small pole cores, each of which extends radially outwardly to face to the inner surfaces of the magnets at their T-shaped pole pieces formed at their forward ends. A capacitor charging coil is wound on the large pole core so that a single pair of positive and negative halfwave voltages are generated at the coil to perform a single spark ignition for each revolution of the magneto generator.