JP2011185110A - Cooling device for internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve cooling performance for cooling an exhaust side of a cylinder bore and a wall part between the cylinder bores, while maintaining, to a certain degree, a warm-up time shortening effect and fuel economy. <P>SOLUTION: This cooling device for an internal combustion engine includes: an exhaust side water jacket part 22A formed of part from a coolant lead-in passage 23 to a coolant flow passage shut-off part 25 through exhaust sides of four cylinder bores 211-214; an intake side water jacket part 22B formed of part from the coolant lead-in passage 23 to the coolant flow passage shut-off part 25 through the intake sides of the four cylinder bores 211-214; and a thermostat valve for opening/closing the intake side coolant discharge passage 24 to stop circulation of the coolant inside the intake side water jacket part 22B while circulating the coolant inside the exhaust side water jacket part 22A. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a cooling device for an internal combustion engine.

  The cooling device for an internal combustion engine disclosed in Patent Document 1 uses the two thermostat valves to cool the inside of the water jacket of the cylinder head while the circulation of the cooling water inside the water jacket of the cylinder block is stopped during warm-up. The water is circulated, and the cooling water in both water jackets can be circulated after the warm-up is completed.

  In this type of internal combustion engine cooling apparatus, the warm-up time can be shortened by quickly warming the cylinder block after the internal combustion engine is cold-started, and the fuel efficiency is improved by reducing the friction loss of the cylinder.

JP 2009-74381A

  However, in the cooling device for an internal combustion engine, when the circulation of the cooling water in the water jacket of the cylinder block is stopped during warm-up, a predetermined cooling water temperature (a thermostat valve is opened and the water temperature of the cylinder block is opened). Even before the cooling water temperature in the jacket starts to circulate), the exhaust side of the cylinder bore and the wall portion between the cylinder bores are locally hot and are likely to be thermally deformed. If this happens, there is a risk that the sealing performance of the cylinder head / gasket will deteriorate and the consumption of lubricating oil will increase. On the other hand, if the water temperature at which the thermostat valve is opened is set low in order to avoid such inconvenience, effects such as shortening the warm-up time and improving fuel efficiency are reduced.

  The present invention was devised in view of such a problem, and is capable of improving the cooling performance of the exhaust side of the cylinder bore and the wall portion between the cylinder bores while maintaining the effect of shortening the warm-up time to some extent. It aims at providing the cooling device of an engine.

  As means for solving the above-described problems, the internal combustion engine cooling apparatus of the present invention is configured as follows.

  That is, the cooling apparatus for an internal combustion engine of the present invention is provided with a cylinder block arrangement of the water jacket, on the premise of including a cylinder block in which a plurality of cylinder bores are formed in a line and a water jacket is formed around the cylinder bores. A cooling water introduction path for introducing cooling water to one end side in the direction, a cooling water flow path blocking portion for blocking a cooling water flow path provided on the other end side in the cylinder bore arrangement direction of the water jacket, and the introduction of the cooling water in the water jacket An exhaust-side cooling water discharge passage for discharging cooling water in an exhaust-side water jacket portion composed of a portion from the passage through the exhaust side of the plurality of cylinder bores to the cooling water flow passage blocking portion, and the cooling water in the water jacket The cooling water flow path from the introduction path via the intake side of the plurality of cylinder bores An intake-side cooling water discharge passage for discharging cooling water in the intake-side water jacket portion consisting of a portion up to the cut portion, and cooling water in the intake-side water jacket portion while circulating the cooling water in the exhaust-side water jacket portion And a valve for opening and closing the intake-side cooling water discharge passage, which is provided so as to stop the circulation of the intake air. In this specification, one side of an internal combustion engine to which an intake system such as an intake manifold is connected is referred to as an “intake side”, and the other side of the internal combustion engine to which an exhaust system such as an exhaust manifold is connected is referred to as “ “Exhaust side”.

  According to the cooling apparatus for an internal combustion engine having such a configuration, the intake side cooling water discharge path is closed by the valve so that the cooling water can be discharged only from the exhaust side cooling water discharge path. The circulation of the cooling water in the intake water jacket portion can be stopped while the cooling water in the exhaust water jacket portion is circulated. Thereby, the exhaust side of the cylinder bore can be more actively cooled than the intake side of the cylinder bore.

  As for the depth of the exhaust side water jacket portion, it is desirable that the position between the cylinder bores in the side view is deeper than the center position of the cylinder bore in the side view. In this specification, the “side view cylinder bore center position” is a position overlapping the center axis of the cylinder bore when the cylinder block is viewed from the exhaust side or the intake side, and the “side view cylinder bore position” is The cylinder block is a position overlapping the wall portion between the cylinder bores as viewed from the side from the exhaust side or the intake side.

  Further, the depth of the exhaust-side water jacket portion may become deeper as approaching the position between the cylinder bores in the side view from the center position in the side view cylinder bores.

  According to the cooling apparatus for an internal combustion engine having such a configuration, the water jacket is relatively deep at the “position between the cylinder bores in a side view”, which has a particularly high heat load among the exhaust-side water jacket portions, thereby cooling the portion concerned. Can be intensively enhanced. Further, the rigidity of the cylinder bore can be increased by making the jacket depth of the “center position of the cylinder bore in side view” having a relatively low thermal load relatively small.

  Further, three or more cylinder bores are formed, and the exhaust-side cooling water discharge passage is provided near each cylinder bore, and communicates with the exhaust-side water jacket portion and the water jacket of the cylinder head. The depth of the center position of the exhaust-side water jacket portion in the side view cylinder bore may be gradually shallower toward the downstream side of the cooling water.

  According to the cooling apparatus for an internal combustion engine having such a configuration, the flow rate of the cooling water flowing in the exhaust-side water jacket portion decreases each time it passes through a communication path provided near the exhaust side of each cylinder bore. Since the depth of the cylinder bore center position in each side view of the exhaust side water jacket portion is gradually shallower as it is located on the downstream side of the cooling water, the cooling water flow rate is maintained to some extent also on the downstream side of the exhaust side water jacket portion. Is done. This makes it possible to maintain the cooling performance of the cylinder bore located on the downstream side of the cooling water, particularly the cooling performance in the vicinity of the deck surface of the cylinder bore having a high thermal load.

  According to the cooling apparatus for an internal combustion engine of the present invention, it is possible to improve the cooling performance on the exhaust side of the cylinder bore while maintaining the effect of shortening the warm-up time to some extent.

It is the top view which looked at the cylinder block of the engine from the deck surface side. It is AA sectional drawing of FIG. It is a circuit diagram which shows the circulation path | route of the cooling water in the cooling device of an engine. It is a graph showing the depth of an exhaust side water jacket part. It is a graph showing the depth of the exhaust side water jacket part which concerns on other embodiment.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the present embodiment, a cooling device for an in-line four-cylinder engine for automobiles will be described as an example. FIG. 1 is a view of the cylinder block 20 of the engine as viewed from the mating surface side with the cylinder head. FIG. 2 is a cross-sectional view taken along the line AA of FIG. FIG. 3 is a circuit diagram showing a circulation path of the cooling water in the cooling device of the engine 10.

  As shown in FIG. 1, four cylinder bores 21,... Are formed in a line in the cylinder block 20, and a water jacket 22 is formed around the cylinder bores 21. A cylinder bore 21 illustrated in FIG. 1 is a Siamese type integrated with adjacent cylinder bores 21 and 21. Further, the water jacket 22 of the cylinder block 20 is an open deck type opened at a mating surface (deck surface 28) with the cylinder head.

  An intake system such as an intake manifold is installed on one side of the cylinder block 20 and a cylinder head (not shown in FIG. 1) installed on the cylinder block 20, and exhaust such as an exhaust manifold is installed on the other side. A system is installed. In the present specification, the one side is referred to as an “intake side” and the other side is referred to as an “exhaust side”. FIG. 1 illustrates the “intake side” and the “exhaust side”, respectively. Further, in this specification, the left side of FIG. 1 will be described as the front side of the engine 10, and the right side will be described as the rear side of the engine 10.

  As shown in FIG. 1, the water jacket 22 of the cylinder block 20 is formed so as to surround the four cylinder bores 21 as viewed from above, and with respect to the cylinder bore center line L connecting the centers of the cylinder bores 211 to 214. Thus, a waveform is formed that is relatively close at the position between the cylinder bores in the side view and relatively separated at the center position of the cylinder bore in the side view. The groove width W of the water jacket 22 is substantially constant, but the depth of the water jacket 22 varies depending on the location. The depth of the water jacket 22 will be described in detail later. The “side view cylinder bore center position” is a position overlapping the center line of the cylinder bore 21 when the cylinder block 20 is viewed from the exhaust side or the intake side, and the “side view cylinder bore position” The cylinder block 20 is a position overlapping the wall portion 27 between the cylinder bores when the cylinder block 20 is viewed from the exhaust side or the intake side. For example, the position between the side bore cylinder bores of the water jacket 22 is a position indicated by an arrow X in FIG. 1, and the side cylinder bore center position of the water jacket 22 is a position indicated by an arrow Z.

  A cooling water introduction passage 23 for introducing cooling water is provided on the intake side of the front end portion (one end side in the arrangement direction of the cylinder bores 21) of the water jacket 22 of the cylinder block 20. In addition, a cooling water flow path blocking portion 25 that blocks the cooling water flow path is provided at the rear end portion of the water jacket 22 (the other end side in the cylinder bore 21 arrangement direction). In the present embodiment, the cooling water flow path blocking unit 25 is configured by a columnar member 251 corresponding to the cross-sectional shape of the water jacket 22 inserted and fixed to the water jacket 22. As the columnar member 251, for example, a base material made of metal, resin, or the like and subjected to rubber coating can be employed. In this case, the rubber coating works to ensure water tightness between the substrate and the wall surface of the water jacket 22. The cooling water flow path blocking portion 25 may be formed integrally with other portions of the cylinder block at the time of casting of the cylinder block, instead of the columnar member 251.

  The water jacket 22 of the cylinder block 20 includes an exhaust side water jacket portion 22 </ b> A composed of a portion from the cooling water introduction path 23 to the cooling water flow passage blocking portion 25 via the exhaust sides of the plurality of cylinder bores 211 to 214, and the cooling water introduction. An intake side water jacket portion 22 </ b> B comprising a portion from the passage 23 to the cooling water flow passage blocking portion 25 via the intake side of the plurality of cylinder bores 211 to 214 is provided.

  An intake side cooling water discharge passage 24 for discharging the cooling water in the intake side water jacket portion 22B is provided at the rear end of the water jacket 22 of the cylinder block 20 (the other end in the arrangement direction of the cylinder bores 21). Yes. In the present embodiment, the intake-side cooling water discharge passage 24 is formed in the cylinder block 20, but the cylinder head gasket 70 is provided with a through hole so as to cool outside the cylinder head through the cylinder head 30. It is also possible to discharge water.

  As shown in FIGS. 1 and 3, the cylinder head gasket 70 is provided with one communication passage 73 formed of a through hole near each cylinder bore 21, and these communication passages 73 serve as the exhaust-side water. The jacket portion 22A communicates with the water jacket of the cylinder head 30. Through this communication passage 73 (exhaust-side cooling water discharge passage), the cooling water in the exhaust-side water jacket portion 22A is led out (discharged) to the water jacket of the cylinder head 30.

  In FIG. 1, reference numeral 26 denotes a bolt hole into which a bolt for fastening the cylinder head onto the cylinder block 20 is screwed.

  Next, the circulation path of the cooling water in the cooling device of the engine 10 will be described with reference to FIG.

  The cooling water discharged from the water pump 60 is introduced from the cooling water introduction passage 23 of the cylinder block 20 to the front portion (around the cylinder bore 211) of the water jacket 22 of the cylinder block 20. When a first thermostat valve 51, which will be described later, is open, the cooling water is diverted in front of the cylinder bore 211, a part of which flows in the water jacket 22 of the cylinder block 20, and the remaining part is the cylinder head gasket. It flows in a water jacket (not shown) of the cylinder head 30 through a communication path 72 formed of a through-hole formed in 70.

  The cooling water flowing in the water jacket 22 of the cylinder block 20 is directed from the front (one side) to the rear (the other side) in the cylinder arrangement direction along both sides of the cylinder bores 211 to 214 as indicated by arrows P1 and P2. Flowing.

  The cooling water flowing through the exhaust-side water jacket portion 22A is led to the water jacket of the cylinder head 30 through the communication passage 73 formed in the cylinder head gasket 70. In addition to the communication passages 72 and 73, the cylinder head gasket 70 may be formed with an air vent hole having a relatively small channel step area.

  The cooling water in the water jacket of the cylinder head 30 generally flows from the front to the rear in the cylinder arrangement direction along the combustion chamber wall of each cylinder as indicated by an arrow P3. It merges with the cooling water that has passed through the intake water jacket portion 22B.

  The junction 54 is provided with a first thermostat valve 51 that opens and closes the intake-side coolant discharge passage 24 of the cylinder block 20 based on the coolant temperature that has passed through the water jacket of the cylinder head 30.

  Specifically, the head side outlet pipe 52 and the block side outlet pipe 53 (the block side outlet pipe 53 is a part of the intake side cooling water discharge passage 24 on the downstream side of the water jacket of the cylinder head 30 and the water jacket 22 of the cylinder block 20. And the downstream end of the block side outlet pipe 53 is connected to the head side outlet pipe 52 in the middle. A connecting portion between the head-side outlet pipe 52 and the block-side outlet pipe 53 serves as the merging portion 54, and the first thermostat valve 51 is provided in the merging portion 54. The thermostat valve 51 is installed so that the valve body opens and closes the cooling water flow path in the block-side outlet pipe 53, and the temperature sensing part senses the temperature of the cooling water flowing in the head-side outlet pipe 52. It is installed as follows.

  The cooling water merged at the merging portion 54 is then branched off at the branch passage 55, and a part of the cooling water is returned to the water pump 60 via the radiator 56 and the second thermostat valve 57. Further, the surplus portion returns to the water pump 60 through the heater 58 and the second thermostat valve 57.

  When the first thermostat valve 51 is closed, the cooling water introduced into the water jacket 22 of the cylinder block 20 flows through the exhaust water jacket portion 22A of the cylinder block 20 and the water jacket of the cylinder head 20. It does not flow to the intake water jacket portion 22B of the cylinder block 20.

  The first thermostat valve 51 is closed when the valve body is lower than the water temperature Tc (for example, Tc = 95 ° C.), opened at the water temperature Tc or higher, and fully opened at the water temperature Tcw (for example, Tcw = 108 ° C.) or higher. Become. Therefore, when the cooling water that has passed through the water jacket of the cylinder head 30 is lower than the predetermined water temperature Tc, the intake-side cooling water discharge passage 24 is closed, and the circulation of the cooling water in the intake-side water jacket portion 22B of the cylinder block 20 is stopped. In this state, cooling water circulates in the exhaust water jacket portion 22A of the cylinder block 20 and the water jacket of the cylinder head 30.

  Further, when the cooling water is lower than a predetermined water temperature Tw (for example, Tw = 82 ° C.), the second thermostat valve 57 closes the valve body to stop the circulation of the cooling water in the radiator 56. On the other hand, when the cooling water is equal to or higher than the predetermined water temperature Tw, the valve body is opened and the cooling water in the radiator 56 is circulated. However, regardless of the open / close state of the second thermostat valve 57, the flow path of the cooling water returning to the water pump 60 from the heater 58 side is always open. In the present specification, when the second thermostat valve 57 is closed during the operation of the engine 10, the cooling water circulation in the radiator 56 is stopped.

  Next, the depth of the water jacket portion 22 of the cylinder block 20 (depth from the deck surface 28) will be described.

  The depth of the exhaust-side water jacket portion 22A increases from the side-view cylinder bore center position Z toward the side-view cylinder bore position X, and the intake-side water jacket portion 22B generally has a depth of the exhaust-side water jacket portion. It is deeper than the portion 22A.

  FIG. 4 is a graph showing the depth of the exhaust-side water jacket portion 22A. The vertical axis of the graph indicates depth, the horizontal axis of the graph indicates a center line L (see FIG. 1), and a line segment extending from the center of each cylinder bore 21 to an arbitrary circumferential position on the exhaust-side water jacket portion 22A. The central angles θ1 to θ4 (see FIG. 1) formed by are shown. That is, an arbitrary circumferential position on the exhaust-side water jacket portion 22A is represented by the central angles θ1 to θ4.

  FIG. 4A shows the depth of the exhaust-side water jacket portion 22A around the first cylinder bore 211. FIG. FIG. 4B shows the depth of the exhaust side water jacket portion 22 </ b> A around the second cylinder bore 212. FIG. 4C shows the depth of the exhaust-side water jacket portion 22A around the third cylinder bore 213. FIG. FIG. 4D shows the depth of the exhaust side water jacket portion 22 </ b> A around the fourth cylinder bore 214. In each graph shown in FIGS. 4A to 4D, the central angles θ1 to θ4 = 90 ° correspond to the “side-view cylinder bore center position Z”, and the central angles θ1 = 150 ° and θ2 = 30. °, 150 °, θ3 = 30 °, 150 °, and θ4 = 30 ° correspond to the “position X between the cylinder bores in side view” described above.

  As shown in FIG. 4A, the depth of the exhaust-side water jacket portion 22A around the first cylinder bore 211 is a depth Hin in the range of the central angle θ1 = −90 ° to −60 °. Here, the central angle θ1 = −90 ° is a position where cooling water is introduced from the cooling water introduction path 23, and the depth Hin is also the depth of the intake-side water jacket portion 22B.

  Further, the depth of the exhaust-side water jacket portion 22A gradually decreases as the central angle θ1 shifts from −60 ° to 0 °, and becomes the depth Hex2 at the central angle θ1 = 0 °, and the central angle θ1 = 0 ° to In the range of 90 °, a constant depth Hex2 is obtained. The depth of the exhaust-side water jacket portion 22A gradually increases as the central angle θ1 shifts from 90 ° to 150 °, and reaches the depth Hex1 at the central angle θ1 = 150 °. As is clear from FIG. 4, when the depths are arranged in the deep order, the depth becomes Hin, the depth Hex1, and the depth Hex2.

  As shown in FIGS. 4B and 4C, the depth of the exhaust-side water jacket portion 22A around the second and third cylinder bores 212 and 233 is such that the central angles θ2 and θ3 are 30 ° to 90 °. It gradually becomes shallower as it moves, and reaches the depth Hex2 at the central angles θ2, θ3 = 90 °. Further, as the central angles θ2 and θ3 shift from 90 ° to 150 °, the depth becomes gradually deeper, and the depth Hex1 is reached at the central angles θ2 and θ3 = 150 °.

  As shown in FIG. 4D, the depth of the exhaust side water jacket portion 22A around the fourth cylinder bore 214 gradually decreases as the central angle θ4 shifts from 30 ° to 90 °, and the central angle θ4 = 90. Depth Hex2 is obtained at the angle of 150 °. Since the coolant flow passage blocking portion 25 is provided at the position of the central angle θ4 = 150 °, the range of the central angle θ4 = 150 ° to 180 ° is outside the range of the exhaust side water jacket portion 22A. In the range of the central angle θ4 = 150 ° to 180 °, the central angle θ4 gradually increases as the central angle θ4 shifts from 150 ° to 180 °, and at the central angle 180 °, the same depth as the depth of the intake water jacket portion 22B. It becomes Hin.

  According to the cooling device for the engine 10 described above, when the coolant temperature is lower than Tc, the first thermostat valve 51 is not opened, and the coolant in the exhaust-side water jacket portion 22A is circulated. The circulation of the cooling water in the intake water jacket portion 22B can be stopped. As a result, the exhaust side of the cylinder bore 21 can be more actively cooled than the intake side of the cylinder bore 21, and the wall temperature between the intake side and the exhaust side of the cylinder bore 21 can be made uniform.

  Further, since the depth of the exhaust side water jacket portion 22A is deeper in the side view cylinder bore position X than in the side view cylinder bore center position Z, the exhaust side water jacket portion 22A is likely to be particularly hot. The wall portion between the cylinder bores 21 can be positively cooled.

  By the way, since the depth of the exhaust side water jacket portion 22A is deeper at the side-view cylinder bore position X than at the side-view cylinder bore center position Z, the average cooling water flow velocity at the side-view cylinder bore position X is descend. For this reason, even if the depth of the water jacket is increased, it seems that the cooling power at the position X between the cylinder bores in the side view is not so different from the cooling power at the center position Z of the cylinder bore in the side view due to the decrease in the flow rate of the cooling water. .

  However, in the exhaust-side water jacket portion 22A, the main flow of the cooling water is formed in the range of the depth 0 to the depth Hex2. Therefore, the deck having a relatively high thermal load at the position X between the cylinder bores in the side view of the exhaust-side water jacket portion 22A. The flow rate of the cooling water flowing near the surface 28 (depth 0 to depth Hex2) is sufficiently maintained. That is, the side-view cylinder bore position X where the depth of the water jacket is relatively deeper is more actively cooled than the side-view cylinder bore center position Z where the depth of the water jacket is relatively shallow. It is like that.

[Other Embodiments]
In the above-described embodiment, the cooling water flowing through the exhaust-side water jacket portion 22A flows out to the water jacket of the cylinder head 30 from the communication passages 73 provided near the cylinder bores 211 to 214, respectively. For this reason, the cooling water flowing through the exhaust-side water jacket portion 22A decreases in flow rate each time it passes through each communication path 73, and is near the deck surface of the cylinder bores 213 and 214 that are cooled downstream of the exhaust-side water jacket portion 22A. There is a possibility that the cooling performance is greatly reduced as compared with the cylinder bores 211 and 212 cooled on the upstream side of the exhaust-side water jacket portion 22A.

  Therefore, in the present embodiment, the depths of the three side-view cylinder bore center positions Z of the exhaust-side water jacket portion 22A are made gradually shallower as they are located on the downstream side of the cooling water. As a result, the flow rate of the cooling water in the vicinity of the deck surface 28 can be maintained to some extent even on the downstream side of the exhaust side water jacket portion 22A. As a result, the cylinder bore 213 cooled on the downstream side of the exhaust side water jacket portion 22A. It is possible to suppress a decrease in cooling performance in the vicinity of the deck surface 214.

  FIG. 5 is a graph showing the depth of the exhaust-side water jacket portion 22A according to the present embodiment. The vertical axis of the graph indicates the depth, and the horizontal axis of the graph indicates the previously described central angles θ1 to θ4 (see FIG. 1).

  FIG. 5A shows the depth of the exhaust-side water jacket portion 22A around the first cylinder bore 211. FIG. FIG. 5B shows the depth of the exhaust water jacket portion 22A around the second cylinder bore 212. FIG. FIG. 5C shows the depth of the exhaust-side water jacket portion 22 </ b> A around the third cylinder bore 213. FIG. 5 (d) shows the depth of the exhaust side water jacket portion 22 </ b> A around the fourth cylinder bore 214. In each graph shown in FIGS. 5A to 5D, the central angles θ1 to θ4 = 90 ° correspond to the “side-view cylinder bore center position Z”, and the central angles θ1 = 150 ° and θ2 = 30. °, 150 °, θ3 = 30 °, 150 °, and θ4 = 30 ° correspond to the “position X between the cylinder bores in side view” described above.

  The depth of the exhaust-side water jacket portion 22A around the first cylinder bore 211 is as shown in FIG. About this Fig.5 (a), since it is a graph similar to Fig.4 (a), description is abbreviate | omitted.

  As shown in FIG. 5B, the depth of the exhaust-side water jacket portion 22A around the second cylinder bore 212 gradually becomes shallower as the central angle θ2 shifts from 30 ° to 90 °, and the central angle θ2 = 90. Depth becomes Hex3. Further, as the central angle θ2 shifts from 90 ° to 150 °, it gradually becomes deeper, and reaches the depth Hex1 at the central angle θ2 = 150 °.

  As shown in FIG. 5C, the depth of the exhaust-side water jacket portion 22A around the third cylinder bore 213 gradually decreases as the central angle θ3 shifts from 30 ° to 90 °, and the central angle θ3 = 90. Depth becomes Hex4. Further, as the central angle θ3 shifts from 90 ° to 150 °, it gradually becomes deeper and reaches the depth Hex1 at the central angle θ3 = 150 °.

  As shown in FIG. 5D, the depth of the exhaust-side water jacket portion 22A around the fourth cylinder bore 214 gradually decreases as the central angle θ4 shifts from 30 ° to 90 °, and the central angle θ4 = 90. Depth Hex5 is obtained at the angle of 150 °. Since the coolant flow passage blocking portion 25 is provided at the position of the central angle θ4 = 150 °, the range of the central angle θ4 = 150 ° to 180 ° is outside the range of the exhaust side water jacket portion 22A. In the range of the central angle θ4 = 150 ° to 180 °, the central angle θ4 gradually increases as the central angle θ4 shifts from 150 ° to 180 °, and at the central angle 180 °, the same depth as the depth of the intake water jacket portion 22B. It becomes Hin.

  As is clear from FIG. 5, when the depths are arranged in the deep order, the depth becomes Hin, depth Hex1, depth Hex2, depth Hex3, depth Hex4, and depth Hex5.

  The present invention can be applied to, for example, an in-line multi-cylinder water-cooled engine of an automobile.

10 Engine (Internal combustion engine)
20 Cylinder block 21 Cylinder bore 22 Cylinder block water jacket 22A Exhaust side water jacket part 22B Intake side water jacket part 23 Cooling water introduction path 24 Intake side cooling water discharge path 25 Cooling water path blocking part 30 Cylinder head 51 First thermostat valve 73 Communication path (exhaust side cooling water discharge path)
X Side view cylinder bore position Z Side view cylinder bore center position

Claims (4)

A cooling device for an internal combustion engine comprising a cylinder block in which a plurality of cylinder bores are formed in a line and a water jacket is formed around the cylinder bores,
A cooling water introduction path for introducing cooling water to one end side in the cylinder bore arrangement direction of the water jacket;
A coolant passage blocking portion provided on the other end side in the cylinder bore arrangement direction of the water jacket;
An exhaust-side cooling water discharge passage for discharging cooling water in an exhaust-side water jacket portion comprising a portion from the cooling water introduction passage through the exhaust side of the plurality of cylinder bores to the cooling water flow passage blocking portion in the water jacket; ,
An intake-side cooling water discharge path for discharging cooling water in the intake-side water jacket section, which is a portion from the cooling water introduction path to the cooling water flow path blocking section via the intake side of the plurality of cylinder bores in the water jacket; ,
A valve for opening and closing the intake-side cooling water discharge path, provided to be able to stop the circulation of the cooling water in the intake-side water jacket portion while circulating the cooling water in the exhaust-side water jacket portion; ,
A cooling device for an internal combustion engine, comprising: The cooling apparatus for an internal combustion engine according to claim 1,
A cooling device for an internal combustion engine, characterized in that the depth of the exhaust-side water jacket portion is deeper in the position between the cylinder bores in the side view than in the center position of the cylinder bore in the side view. The cooling apparatus for an internal combustion engine according to claim 1,
The cooling device for an internal combustion engine according to claim 1, wherein the depth of the exhaust-side water jacket portion becomes deeper as it approaches the position between the cylinder bores in the side view from the center position in the side view cylinder bores. The internal combustion engine cooling device according to claim 2 or 3,
Three or more cylinder bores are formed,
The exhaust-side cooling water discharge path is a communication path that is provided near each cylinder bore and communicates the exhaust-side water jacket portion and the water jacket of the cylinder head,
A cooling apparatus for an internal combustion engine, wherein a depth of a cylinder bore center position of the exhaust-side water jacket portion in a side view is gradually shallower as it is located downstream of the cooling water.

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