Four-stroke engine with pre-ignition

Abstract

The pre-chamber (20) of a four-stroke pre-ignition engine (1) is formed such that the greater length, between the length (L1) of an internal space of the pre-chamber in an axial direction (DP) of a pre-chamber spark plug (23) and the maximum length (L2) of the internal space of the pre-chamber in a direction orthogonal to the axial direction of the spark plug, is less than twice the smaller length. The angle θ formed by the segment (LSa), connecting the central axis (C23) of the pre-chamber spark plug and the center (C3a) of a first intake port (3a), considered along the central axis (C21ia) of the first intake port (21a), is -17° < θ < 17°. The central axis of the first intake port passes between the valve head (14) of an intake valve and the first intake opening when the intake valve (13), which can open and close the first intake opening, is open. Figure for the abbreviation: Figure 1

Inventors

EGASHIRA SHUICHI

Assignees

YAMAHA MOTOR CO LTD

Dates

Publication Date: 20260501
Application Date: 20230214
Priority Date: 20220215