Vehicular headlamp

A vehicular headlamp comprising:

• an external case of a lamp constituted by a lamp housing with an opening and a cover that covers the opening of the lamp housing;
• and
• a lamp unit disposed within the external case,
• the lamp unit includes:
• a light source unit including a light source, a light source placing part in which the light source is placed, a reflector that reflects light emitted from the light source, and a heat sink that dissipates heat generated when the light source is driven;
• a fixation frame fixed within the external case;
• a movable frame supported on the fixation frame to be movable in one of a horizontal direction and a vertical direction with respect to the fixation frame within the external case;
• a lens unit including a projection lens that projects the light emitted from the light source and a lens holder provided with a slide part holding the projection lens and supported on the movable frame to be movable in the other one of the horizontal direction and the vertical direction within the external case;
• a first aiming operating shaft configured to perform an optical axis adjustment by moving the movable frame in one of the horizontal direction and the vertical direction with respect to the fixation frame;
• a second aiming operating shaft configured to perform the optical axis adjustment by moving the lens unit in the other one of the horizontal direction and the vertical direction with respect to the movable frame;
• a connection member including a connection part connected to the lens unit and configured to be movable integrally with the lens unit in one of the horizontal direction and the vertical direction by operating the first aiming operating shaft or the second aiming operating shaft;
• and
• a leveling actuator including a body part and a driving part, that is movable in the vertical direction with respect to the body part and is connected to the movable frame or the lens unit, and configured to be movable in the vertical direction with respect to the fixation frame and perform the optical axis adjustment,
• wherein the lens unit moves in the horizontal direction and the vertical direction with respect to the fixation frame within the external case in a state where a distance from a focus of the light emitted from the light source and reflected by the reflector to the projection lens is constant,
• the light source unit is fixed to the lamp housing in a state where the heat sink is positioned outside the external case and configured such that the heat sink does not move together with the lens unit when the optical axis adjustment is performed, and
• each of the movable frame, the lens unit and the leveling actuator is configured to move in the vertical direction integrally with each other and the slide part of the lens holder of the lens unit is configured to slide vertically with respect to the connection member.