Patent ID: 11909179
Assignee: DENSO CORPORATION
Field: Engines, pumps, turbines (Mechanical engineering)
Classification: CPC H  F  Y | IPC H

Claim 0:
1. A spark plug for an internal combustion engine, the spark plug having an axial direction and comprising:
a tubular insulator having a tip-side end;
a center electrode having one side and a tip-side end, the center electrode being disposed inside the insulator with the tip-side end of the center electrode protruding outwardly from the tip-side end of the insulator;
a tubular housing that has a tip-side end and retains the insulator thereinside;
a ground electrode having a stationary end and a projection-end edge opposite to the stationary end, and one side; and
a plug cover mounted to the tip-side end of the housing to define a sub-chamber between the plug cover and the tip-side end of the housing,
wherein:
the stationary end of the ground electrode is mounted to the tip-side end of the housing;
the projection-end edge of the ground electrode projects to be located in the sub-chamber such that the one side of the ground electrode serves as a facing side facing the one side of the center electrode, resulting in a discharge gap being formed between the facing side of the ground electrode and the one side of the center electrode;
the plug cover has formed therethrough at least one injection hole that enables the sub-chamber to communicate with an outside thereof, the at least one injection hole having a center axis;
the center axis of the at least one injection hole is inclined with respect to a radial direction of the spark plug as viewed in the axial direction of the spark plug;
the at least one injection hole serves as a ground-directed injection hole arranged to face the facing side of the ground electrode, and an extension line of the center axis of the at least one ground-directed injection hole intersects with the facing side of the ground electrode at an intersection point;
the facing side of the ground electrode has a closer region closer to the projection-end edge of the ground electrode than the intersection point is; and
the closer region of the facing side intersects with the extension line of the center axis of the ground-directed injection hole at a predetermined angle as viewed in the axial direction of the spark plug, the predetermined angle being an obtuse angle.