PURPOSE: To promote warming up of an internal combustion engine so as to improve a fuel consumption and suppress abrasion by providing lower small holes which are positioned near the opening part of the oil absorbing pipe of an oil pump and upper large holes which are positioned in the vicinity of an oil surface, on the side surface of the bulkhead plate.
CONSTITUTION: A bulkhead plate 3 is provided in an oil pan 1 to partition it into a main chamber 1a and an auxiliary chamber 1b. Lower small holes 4a which are positioned near the opening part of an oil absorbing pipe 7 of an oil pump 6 and upper large holes 4b which are positioned near an oil surface 2, are provided on the side surface 3a of the bulkhead plate 3. Oil in the auxiliary chamber 1b can not pass the small holes 4a of the bulkhead plate 3, since an oil temperature is low and viscosity resistance of oil is large in warming up condition after starting. Therefore, since only oil in the main chamber 1a is absorbed by an oil pump 6 to circulate oil into an engine, a small amount of oil is heated in the engine. As a result, a temperature rises rapidly so as to warm up the engine rapidly.
ITO TOSHIHIKO
SASAO SHIGEO
OHORI MASAE
TOYOTA MOTOR CORP