US 2017/0288375 A1Published application

Spark plug

AssigneeDenso Corporation

InventorsTomoyuki WATANABE, Hiroshi ARAKI

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Abstract

The spark plug has a shaft shaped center electrode, insulator, terminal fitting, ground electrode and resistor. The insulator has an axially penetrating shaft hole, and the center electrode is held in a tip end side of the shaft hole. The terminal fitting has a shaft and a terminal part. The shaft is held in a base end side of the shaft hole. The terminal part is projected from a base end of the shaft hole to a base end side of the spark plug. The ground electrode faces the center electrode in a tip end side of the shaft hole. The resistor is disposed between the center electrode and the terminal fitting in the shaft hole. An axial length L of the resistor is 15 mm≦L≦22.5 mm. An axial length T of the shaft satisfies a relation of 1.25≦T/L.

Claims5

Dependent claims

A spark plug comprising:

a center electrode which has an elongated shaft shape;
an insulator which has a shaft hole penetrated therein in an axial direction, and the center electrode is held in a tip end side of the shaft hole;
a terminal fitting which has a shaft and a terminal part, and the shaft is held in a base end side in the shaft hole, and the terminal part is projected from a base end of the shaft hole to a base end side of the spark plug in the axial direction;
a ground electrode which faces the center electrode in the tip end side of the shaft hole;
and
a resistor which is disposed between the center electrode and the terminal fitting in the shaft hole,
wherein a length L of the resistor in the axial direction is 15 mm≦L≦22.5 mm,
wherein a length T of the shaft in the axial direction and the length L of the resistor are in a relation of 1.25≦T/L.

5 more elements

Dependencies are inferred from the claim text.

Facts

Application: 15/473,685Filed 30 Mar 2017
Priority: JP 2016-07097231 Mar 2016
Published: 5 Oct 2017
Term ends: Not estimatedThe source records don’t support an estimate.

Classification5 codes

H01T 13/41
Structurally combined with other devices: with interference suppressing or shielding means
H01T 13/20
Sparking plugs: characterised by features of the electrodes or insulation
H01T 13/32
Characterised by features of the electrodes or insulation: characterised by features of the earthed electrode
H01T 13/39
Characterised by features of the electrodes or insulation: selection of materials for electrodes

Family

US 9,831,638 B2Related patent
US 2017/0288375 A1This patent

From the US filing history. Foreign family members aren’t listed.

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