Cooling device for engine

Abstract

A cooling device 1 A includes an engine 50 A provided with W/Js 501, 502 , and 503 A, and a first control valve 31 . The W/J 501 is provided at an intake side in a cylinder block 51 A. The W/J 502 is provided at an exhaust side in the cylinder block 51 A. The W/J 503 A diverges from a given position of the W/J 501 . Also, the W/J 503 A is provided toward the exhaust side through the intake side of the cylinder head 52 A. The first control valve 31 makes the coolant flowing state changeable between a state where the coolant is caused to flow in the W/J 501 and a state where the coolant is caused to flow in the W/Js 501 and 503 A.

1 . An engine cooling device comprising:
 an engine including a cylinder block, a cylinder head, an intake side cooling medium passage, an exhaust side cooling medium passage, and a divergent cooling medium passage; and   a first state change portion;   wherein the intake side cooling medium passage is provided at an intake side in the cylinder block, and is provided in such a direction as to arrange a plurality of bores provided in the cylinder block,   the exhaust side cooling medium passage is provided at an exhaust side in the cylinder block, is independent of the intake side cooling medium passage, and is provided in such a direction as to arrange the plurality of the bores,   the divergent cooling medium passage diverges from a given position of the intake side cooling medium passage, is provided from the intake side cooling medium passage toward the exhaust side of the cylinder head through the intake side of the cylinder head, and is provided at the exhaust side in such a direction as to arrange the plurality of the bores, and   the first state change portion makes a cooling medium flowing state changeable between a state where the cooling medium is caused to flow in the intake side cooling medium passage and a state where the cooling medium is caused to flow in the intake side cooling medium passage and the divergent cooling medium passage, selected from the intake side cooling medium passage and the divergent cooling medium passage.   
     
     
         2 . The engine cooling device of  claim 1 , further comprising a first flow control portion including the first state change portion, causing the cooling medium to flow in the intake side cooling medium passage and the exhaust side cooling medium passage when an engine driving state is in a low speed and a high load, and causing the cooling medium to flow in the intake side cooling medium passage selected from the intake side cooling medium passage and the divergent cooling medium passage. 
     
     
         3 . The engine cooling device of  claim 1 , further comprising a second flow control portion including the first state change portion, prohibiting the cooling medium from flowing in the intake side cooling medium passage and the exhaust side cooling medium passage when the engine driving state is in a low load. 
     
     
         4 . The engine cooling device of  claim 1 , further comprising:
 a heat exchanger transferring heat between air and the cooling medium caused to flow in the exhaust side cooling medium passage;   a heat accumulator storing the cooling medium caused to flow in the exhaust side cooling medium passage, and keeping heat of the cooling medium;   a second state change portion making the cooling medium flowing state changeable between a state where the cooling medium is caused to flow in the heat exchanger and the a state where the cooling medium is caused to flow in the heat accumulator selected from the heat exchanger and the heat accumulator; and   a third flow control portion including the second state change portion, causing the cooling medium to flow in the exhaust side cooling medium passage when the engine driving state is in a cold driving or in an engine starting, and causing the cooling medium to flow in the heat accumulator, selected from the heat exchanger and the heat accumulator.   
     
     
         5 . The engine cooling device of  claim 1 , further comprising a high heat conductive portion provided at a portion between adjacent bores selected from the plurality of the bores, exposed from a deck surface of the cylinder block, and having a heat conductivity higher than a base material of the cylinder block. 
     
     
         6 . The engine cooling device of  claim 5 , wherein
 the high heat conductive portion includes a channel portion and a high heat conductive material,   the channel portion is provided at the portion between the adjacent bores selected from the plurality of the bores of the cylinder block, opens toward the deck surface, and has a given depth, and   a material is supplied to the channel portion and is melted by a laser beam, whereby the high heat conductive material is provided at the channel portion so as to be exposed at the deck surface and has a heat conductivity higher than the base material of the cylinder block.