Actuator and method of manufacturing the same

A method of manufacturing an actuator including:

• a motor having a rotation shaft;
• an output shaft which outputs rotation of the rotation shaft;
• a speed reduction mechanism provided between the rotation shaft and the output shaft;
• and
• a case in which the motor and the speed reduction mechanism are accommodated,
• the case having:
• an accommodating portion in which the motor is accommodated;
• a support portion provided and arranged side by side with the accommodating portion in a direction crossing an axial direction of the accommodating portion, the support portion supporting the output shaft,
• a convex portion provided to the support portion and located on the opposite side of the support portion from the accommodating portion, the convex portion protruding in a direction crossing the output shaft;
• a weld line provided to the accommodating portion and located on the opposite side of the support portion from the support portion, the weld line being formed by the merger of molten material;
• and
• a reinforcing rib provided to a portion in which the weld line is formed, the reinforcing rib protruding from the accommodating portion to outside,
• the method comprising:
• a mold preparing step of causing upper and lower molds forming the case to face each other so as to form a cavity for forming the case;
• a filling step of actuating a dispenser to supply molten material to a supply passage provided to at least one of the upper and lower mold, and filling the cavity with molten material to form the convex portion on the same side as the supply passage of the cavity, and to form the weld line on the opposite side of the cavity from the supply passage;
• a cooling step of stopping the dispenser and cooling the upper and lower molds to cure the molten material in the cavity;
• and
• a removing step of separating the upper and lower molds from each other to remove the case from the upper and lower molds after curing from the upper and lower molds.