An ignition apparatus for internal combustion engines is provided. The ignition apparatus is equipped with an ECU. The ECU monitors a path length of a discharge of a spark for a period of time in which a second circuit delivers or inputs energy in the form of a threshold value determination. When the path length has become too short, the ECU determines that ignition is expected to be delayed and then selects a special mode to control the delay of the ignition. The ECU increase a target value of an energy input amount. This enables the delay of ignition resulting from a short extension of the path length to be minimized. The ignition apparatus equipped with the second circuit to continue the discharge of sparks is, thus, capable of reducing a variation in ignition without the need for uniformly increasing the energy input amount.

An ignition apparatus for internal combustion engines is provided. The ignition apparatus is equipped with an ECU. The ECU monitors a path length of a discharge of a spark for a period of time in which a second circuit delivers or inputs energy in the form of a threshold value determination. When the path length has become too short, the ECU determines that ignition is expected to be delayed and then selects a special mode to control the delay of the ignition. The ECU increase a target value of an energy input amount. This enables the delay of ignition resulting from a short extension of the path length to be minimized. The ignition apparatus equipped with the second circuit to continue the discharge of sparks is, thus, capable of reducing a variation in ignition without the need for uniformly increasing the energy input amount.

A spark plug assembly includes a spark plug, where the spark plug includes a high voltage connector, an insulator body, a metallic shell, and an electrical conductor at least partly disposed in the insulator body and the metallic shell. The spark plug assembly includes a detection unit having a transmitter device and a receiver device. The transmitter device is coupled to the spark plug and is electrically disposed between the high voltage connector and the electrical conductor. Further, the transmitter device is configured to draw an excitation current from the electrical conductor. The transmitter device includes an optical signal generator that is configured to generate an optical signal in response to the drawn excitation current. The receiver device is disposed in optical communication with the transmitter device and configured to receive the optical signal from the transmitter device.

A spark plug assembly includes a spark plug, where the spark plug includes a high voltage connector, an insulator body, a metallic shell, and an electrical conductor at least partly disposed in the insulator body and the metallic shell. The spark plug assembly includes a detection unit having a transmitter device and a receiver device. The transmitter device is coupled to the spark plug and is electrically disposed between the high voltage connector and the electrical conductor. Further, the transmitter device is configured to draw an excitation current from the electrical conductor. The transmitter device includes an optical signal generator that is configured to generate an optical signal in response to the drawn excitation current. The receiver device is disposed in optical communication with the transmitter device and configured to receive the optical signal from the transmitter device.

In order to test a semiconductor spark plug, a test method comprises a step consisting of depositing water on the head of the spark plug, between the two electrodes of same, so that the water forms a water meniscus covering the semiconductor element of the head, a step consisting of applying, between the first terminal and the second terminal of the spark plug, a voltage equal to the operating voltage of the spark plug, a step consisting of identifying at least a first characteristic of electric arcs induced between the electrodes during the application of the voltage, and a step consisting of determining the operational or defective character of the spark plug according to the first characteristic of the electric arcs. This test method is particularly reliable and does not require constraining provisions in order to ensure the safety of the operators implementing the method.

Disclosed is a production method of a spark plug in which a ground electrode has an electrode base and a tip welded to a surface of the electrode base via a weld metal. The production method includes an image capture step, an image analysis step and an inspection step. The image capture step is to capture image data about the surface of the electrode base to which the tip has been welded. The image analysis step is to perform analysis of the image data, thereby detecting an edge of the electrode base and an edge of the weld metal, determining a center point of a contour of the weld metal and then detecting an edge of the tip in a specific area of the image data. The inspection step is to inspect a welding position of the tip based on the detected edges of the electrode base and the tip.

A spark detector indicates the presence of a spark by analyzing sound waves generated when an electrical spark is produced from an electrical spark generator located on an igniter rod. The spark detector includes an acoustic sensor that is in communication with the igniter rod to determine the time for the spark sound wave to travel through the igniter rod to the acoustic sensor. If a spark is not detected, the spark detector may output a signal indicating at least one of (i) the spark was not detected, (ii) to replace the electrical spark generator immediately, or (iii) replace the electrical spark generator soon such as at the next scheduled maintenance. Furthermore, the spark detector may be calibrated based on current temperature of the igniter rod based upon time of propagation of a pulse sound wave, generated by a pulse-echo generator, to reflect off an end of the igniter rod.

A spark detector indicates the presence of a spark by analyzing sound waves generated when an electrical spark is produced from an electrical spark generator located on an igniter rod. The spark detector includes an acoustic sensor that is in communication with the igniter rod to determine the time for the spark sound wave to travel through the igniter rod to the acoustic sensor. If a spark is not detected, the spark detector may output a signal indicating at least one of (i) the spark was not detected, (ii) to replace the electrical spark generator immediately, or (iii) replace the electrical spark generator soon such as at the next scheduled maintenance. Furthermore, the spark detector may be calibrated based on current temperature of the igniter rod based upon time of propagation of a pulse sound wave, generated by a pulse-echo generator, to reflect off an end of the igniter rod.

A method of detecting the breakdown voltage between the electrodes of a spark plug connected to an ignition coil for a cylinder ignition system, in an internal combustion engine, includes a detection of an opening of the switch on the primary winding and a detection of a voltage on that primary winding, with the generation of a first signal representative of the voltage trend following the opening of the switch. The first signal is then integrated and, following an identification of a breakdown at the ends of the spark plug, a breakdown voltage value is determined as a function of the value of the integrated signal at the time of the breakdown.

A method of detecting the breakdown voltage between the electrodes of a spark plug connected to an ignition coil for a cylinder ignition system, in an internal combustion engine, includes a detection of an opening of the switch on the primary winding and a detection of a voltage on that primary winding, with the generation of a first signal representative of the voltage trend following the opening of the switch. The first signal is then integrated and, following an identification of a breakdown at the ends of the spark plug, a breakdown voltage value is determined as a function of the value of the integrated signal at the time of the breakdown.