Warming-up promoting apparatus of internal combustion engine

A warming-up promoting apparatus of an internal combustion engine comprising:

• an oil pan in which oil is stored;
• a partition member disposed in said oil pan of said internal combustion engine and including a substantially vertical wall and a slightly inclined ceiling, said substantially vertical wall serving to divide an interior space of said oil pan into a main chamber and an antechamber, and said slightly inclined ceiling serving to cover a top of said antechamber;
• an oil pump having a draft tube which is opened in said main chamber at a position adjacent to a bottom of said main chamber, said oil pump being for pumping the oil from said oil pan to said engine;
• a first hole means provided in a lower region of said substantially vertical wall of said partition member in the vicinity of an opening of said draft tube for making said main chamber and said antechamber communicate with each other constantly, an effective area of said first hole means being small enough to prevent the oil from being interchanged between said antechamber and said main chamber through said first hole means when a temperature of oil is low;
• and
• a second hole means provided in an upper region of said substantially vertical wall of said partition member below an oil level and making said main chamber and said antechamber communicate with each other constantly, an effective area of said second hole means being large enough to permit the oil to be interchanged between said antechamber and said main chamber through said second hole means.