Engine warm-up apparatus for vehicle

An engine warm-up apparatus for a vehicle comprising;

• a cooling-water circuit for circulating cooling water through an engine of the vehicle;
• a warm-up device arranged in the cooling-water circuit in such a way that the warm-up device works as a fluid resistance for a flow of the cooling water flowing into the engine, wherein the warm-up device operatively heats the cooling water during a start-up operation of the engine,
• wherein the warm-up device comprises;
• (i) a heat accumulating device having heat accumulating material for carrying out heat exchange between the cooling water and the heat accumulating material in order that waste heat of the engine is accumulated in the heat accumulating material and/or heat accumulated in the heat accumulating material is radiated to the cooling water;
• (ii) a passage switching device for switching a water passage for the cooling water flowing into the engine from a heat accumulating passage in which the cooling water flows through the heat accumulating device to an accumulating-device bypassing passage in which the cooling water bypasses the heat accumulating device;
• and
• (iii) a control unit for controlling e passage switching device in such a way that;
• (iii-a) the cooling water is circulated only through the heat accumulating device when temperature of the cooling water flowing into the warm-up device is lower than a first threshold value during the start-up operation of the engine so as to carry out a warm-up mode, wherein the first threshold, value corresponds to a temperature indicating a first-stage completion of a warm-up operation of the engine,
• (iii-b) the cooling water is circulated only through the accumulating-device bypassing passage when the engine is in its operation and when the temperature of the cooling water flowing into the warm-up device is higher than the first threshold value so as to carry out a cooling mode, and
• (iii-c) the cooling water is circulated only through the heat accumulating device when the temperature of the cooling water flowing into the warm-up device is higher than a second threshold value during the operation of the engine is temporarily stopped so as to carry out a heat accumulating mode, wherein the second threshold value corresponds to a temperature indicating a second-stage completion of the warm-up operation of the engine and the second threshold value is higher than the first threshold value.

An engine warm-up apparatus for a vehicle comprising;

• a cooling-water circuit for circulating cooling water through an engine of the vehicle;
• a warm-up device arranged in the cooling-water circuit in such a way that the warm-up device works as a fluid resistance for a flow of the cooling water flowing into the engine, wherein the warm-up device operatively heats the cooling water during a start-up operation of the engine,
• wherein the warm-up device comprises a heat accumulating device having heat accumulating material for carrying out heat exchange between the cooling water and the heat accumulating material in order that waste heat of the engine is accumulated in the heat accumulating material and/or heat accumulated in the heat accumulating material is radiated to the cooling water,
• wherein the heat accumulating material is composed of such material, which carries out a phase change from a solid state to a liquid phase, and
• wherein the warm-up device controls a flow amount of the cooling water flowing into the engine depending on a volume change of the heat accumulating material caused by the phase change of the heat accumulating material.