| 摘要 |
PROBLEM TO BE SOLVED: To provide an engine cooling device which can improve a warm-up efficiency and sufficiently increase a circulation flow rate of cooling water, when cooling an engine in the combination of a mechanical water pump and an electrical water pump.SOLUTION: An engine cooling device 100 includes a mechanical water pump 10 which is driven by an engine 91 and is rotated synchronously with a rotation of the engine 91, an electrical water pump 20 which is provided in parallel with the mechanical water pump 10 and can change its revolution speed independently from the rotation of the engine 91, and a first switch valve 30 which is provided in a discharge side of the mechanical water pump 10, is opened when a temperature Tw of cooling water is higher than a first threshold value temperature T1, and blocks the flow from the mechanical water pump 10 when the temperature Tw of cooling water is equal to or less than the first threshold value temperature T1.SELECTED DRAWING: Figure 1 |
