An ignition coil for internal combustion engines is provided which includes a primary coil, a secondary coil, a case, a high-voltage terminal, a resistor, and a filled resin. The case has a case body and a high-voltage terminal extending downward from the case body. The high-voltage terminal is press-fit in the high-voltage tower to close the inside thereof. The resistor is fit in the high-voltage terminal. The high-voltage terminal includes a pressed wall and a non-pressed wall. The pressed wall is pressed against the high-voltage tower. The non-pressed wall is not pressed against the high-voltage tower. The resistor is fit in the non-pressed wall. This structure minimizes pressure exerted on the resistor and the high-voltage tower to secure a desired degree of durability of the resistor and the high-voltage tower.

One example provides a spark plug having a center electrode including first material and a second material, the second material having a hardness rating greater than a hardness rating of the first material. The center electrode includes an electrode head, wherein at least a portion of the electrode head is disposed beyond an end surface of an insulative nose toward the firing end and has a cross-sectional area perpendicular to an axial centerline greater than a cross-sectional area of the end surface of the insulative nose. The center electrode has a region of first material disposed axially beyond the end surface of the insulative nose, and includes a shield element of the second material which covers exposed surfaces of the region of first material disposed beyond the end surface of the insulative nose. An electrode wire extends from the electrode head into a central bore of the insulative nose.

One example provides a spark plug having a center electrode including first material and a second material, the second material having a hardness rating greater than a hardness rating of the first material. The center electrode includes an electrode head, wherein at least a portion of the electrode head is disposed beyond an end surface of an insulative nose toward the firing end and has a cross-sectional area perpendicular to an axial centerline greater than a cross-sectional area of the end surface of the insulative nose. The center electrode has a region of first material disposed axially beyond the end surface of the insulative nose, and includes a shield element of the second material which covers exposed surfaces of the region of first material disposed beyond the end surface of the insulative nose. An electrode wire extends from the electrode head into a central bore of the insulative nose.

An ignition apparatus for an internal combustion engine which is capable of having a high-degree of ignition performance and being reduced in size is provided. The ignition apparatus includes the spark plug mounted in an end of the plug hole formed in the internal combustion engine, the first ignition coil, the second ignition coil, and the control portion. The first ignition coil includes the primary coil and the secondary coil and has a secondary side electrically connected to the spark plug. The second ignition coil includes the primary coil and the secondary coil and is connected to the spark plug in parallel to the first ignition coil. The control portion controls energization of the first ignition coil and the second ignition coil. The secondary voltage developed at the second ignition coil is lower in level than that developed at the first ignition coil. The control portion works to create the secondary voltage at the first ignition coil and then create the secondary voltage at the second ignition coil to have the spark plug continue to discharge.

A car ignition device and an ignition accelerator are disclosed. The car ignition device includes a magnetic shielding conductive element, a spark plug and a magnetic element. The magnetic shielding conductive element has a first disposing portion and a second disposing portion. One end of the spark plug is disposed inside the first disposing portion and electrically connected with the magnetic shielding conductive element. The magnetic element is disposed at the second disposing portion, and has a north-seeking pole and a south-seeking pole. The north-seeking pole is located at one side of the magnetic element near the spark plug. The south-seeking pole is located at another side of the magnetic element away from the spark plug. The magnetic shielding conductive element shields a magnetic force of the magnetic element in a direction toward the spark plug. The invention has higher ignition efficiency.

A car ignition device and an ignition accelerator are disclosed. The car ignition device includes a magnetic shielding conductive element, a spark plug and a magnetic element. The magnetic shielding conductive element has a first disposing portion and a second disposing portion. One end of the spark plug is disposed inside the first disposing portion and electrically connected with the magnetic shielding conductive element. The magnetic element is disposed at the second disposing portion, and has a north-seeking pole and a south-seeking pole. The north-seeking pole is located at one side of the magnetic element near the spark plug. The south-seeking pole is located at another side of the magnetic element away from the spark plug. The magnetic shielding conductive element shields a magnetic force of the magnetic element in a direction toward the spark plug. The invention has higher ignition efficiency.

A car ignition device and an ignition accelerator are disclosed. The car ignition device includes a magnetic shielding conductive element, a spark plug and a magnetic element. The magnetic shielding conductive element has a first disposing portion and a second disposing portion. One end of the spark plug is disposed inside the first disposing portion and electrically connected with the magnetic shielding conductive element. The magnetic element is disposed at the second disposing portion, and has a north-seeking pole and a south-seeking pole. The north-seeking pole is located at one side of the magnetic element near the spark plug. The south-seeking pole is located at another side of the magnetic element away from the spark plug. The magnetic shielding conductive element shields a magnetic force of the magnetic element in a direction toward the spark plug. The invention has higher ignition efficiency.

A car ignition device and an ignition accelerator are disclosed. The car ignition device includes a magnetic shielding conductive element, a spark plug and a magnetic element. The magnetic shielding conductive element has a first disposing portion and a second disposing portion. One end of the spark plug is disposed inside the first disposing portion and electrically connected with the magnetic shielding conductive element. The magnetic element is disposed at the second disposing portion, and has a north-seeking pole and a south-seeking pole. The north-seeking pole is located at one side of the magnetic element near the spark plug. The south-seeking pole is located at another side of the magnetic element away from the spark plug. The magnetic shielding conductive element shields a magnetic force of the magnetic element in a direction toward the spark plug. The invention has higher ignition efficiency.

A spark plug having a connection portion disposed between a metal terminal and a center electrode. The connection portion includes: a magnetic substance formed from a Fe-containing oxide; a conductor which is a wire helically disposed on an outer periphery of the magnetic substance and electrically connected to the metal terminal and the center electrode; and an intermediate member which is in contact with the magnetic substance, the conductor, and an inner peripheral surface of the insulator, is disposed between the magnetic substance and the conductor, and the inner peripheral surface of the insulator, and has lower electrical conductivity than the conductor. The conductor is made of one or more of an oxide conductor, carbon, and a carbon compound.

A spark plug having a connection portion disposed between a metal terminal and a center electrode. The connection portion includes: a magnetic substance formed from a Fe-containing oxide; a conductor which is a wire helically disposed on an outer periphery of the magnetic substance and electrically connected to the metal terminal and the center electrode; and an intermediate member which is in contact with the magnetic substance, the conductor, and an inner peripheral surface of the insulator, is disposed between the magnetic substance and the conductor, and the inner peripheral surface of the insulator, and has lower electrical conductivity than the conductor. The conductor is made of one or more of an oxide conductor, carbon, and a carbon compound.