SPARK PLUG

摘要

A spark plug having an insulator, a metallic shell disposed around the insulator, a first ground electrode having a first surface facing a side surface of a center electrode in a radial direction so as to form a first gap, and a second ground electrode having a second surface facing the side surface of the center electrode in the radial direction so as to form a second gap. A relation 60°≦θ≦150° is satisfied, where θ is a smaller one of angles formed between a first line connecting an axial line of the center electrode and the center of the first surface and a second line connecting the axis and a center of the second surface when viewed from a forward end side toward a rear end side in the direction of the axis.

主权项

1. A spark plug comprising:
a center electrode extending in a direction of an axial line; an insulator having an axial hole which extends in the direction of the axial line and in which the center electrode is disposed; and a metallic shell disposed around the insulator, wherein the metallic shell has a first ground electrode which is electrically connected to the metallic shell and has a first surface facing a side surface of the center electrode in a radial direction so as to form a first gap, and a second ground electrode which is electrically connected to the metallic shell and has a second surface facing the side surface of the center electrode in the radial direction so as to form a second gap; a relation 60°≦θ≦150° is satisfied, where θ is a smaller one of angles formed between a first line connecting the axis and a center of the first surface and a second line connecting the axial line and a center of the second surface when viewed from a forward end side toward a rear end side in the direction of the axis; and the metallic shell has a specific plane which bisects the metallic shell such that all the ground electrodes are located on one side of the plane.