Patent ID: 8164243
Filing Date: 2012-04-24
Classification: H01T

Abstract:
1. A spark plug for an internal combustion engine, comprising: a rod-like center electrode; a tubular insulator having an axial hole extending along the direction of an axis of the center electrode and holding the center electrode placed in the axial hole; a tubular metallic shell provided radially outward of the insulator; a ground electrode extending from a front end portion of the metallic shell and bent such that a distal end of the ground electrode is directed toward the axis; a center-electrode-side chip joined to a distal end of the center electrode and extending from the center electrode along the direction of the axis; and a ground-electrode-side chip joined to a distal end surface of the ground electrode, the ground-electrode-side chip being thinner than the distal end surface of the ground electrode and having a distal end surface which faces a side surface portion of the center-electrode-side chip, wherein an angle θ an angle θ a minimum distance between the insulator and the ground electrode is greater than a minimum distance between the distal end surface of the ground-electrode-side chip and the side surface portion of the center-electrode-side chip so as to generate a spark discharge between the ground-electrode-side chip and the center-electrode-side chip.