JP2008157102A - Cooling device for internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve exhaust emission purification performance by efficiently using heat recovered from exhaust gas, in a cooling device for an internal combustion engine. <P>SOLUTION: An intake side water jacket 52 penetrating a peripheral part of an intake port 17, and an exhaust side water jacket 53 penetrating peripheral parts of an exhaust port and an exhaust collecting passage 32 are formed in a cylinder head 12. A water pump 67 can supply cooling water to a water jacket 51 and the intake side water jacket 52 through a first cooling water supply passage 68, and on the other hand, can supply the cooling water to the exhaust side water jacket 53 through a second cooling water passage 69. The cooling water of the exhaust water jacket 53 can be supplied to a cooling water passage of a turbocharger 35 through a third cooling water supply passage 70. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention circulates cooling water in a cooling water passage formed in a cylinder block or a cylinder head and circulates cooling water in a cooling water passage formed in an auxiliary machine such as a heater core or a turbocharger. The present invention relates to a cooling apparatus for an internal combustion engine that efficiently cools the entire internal combustion engine.

  In a general water-cooled engine, a water jacket is provided in a cylinder head or a cylinder block, and the water jacket and the radiator are connected via a cooling water circulation passage. Then, the cooling water is circulated between the water jacket and the radiator by the water pump, so that the entire engine is uniformly cooled, while the cooling water whose temperature is increased by cooling the engine is cooled by the radiator. In addition, the engine has a turbocharger and a throttle body as auxiliary machines that need to be cooled, and these are cooled by circulating cooling water from the water jacket to the turbocharger and the throttle body. .

  FIG. 5 is a schematic configuration diagram illustrating a conventional cooling device for an internal combustion engine. In a conventional cooling apparatus for an internal combustion engine, as shown in FIG. 5, an engine body is formed by fastening a cylinder head 002 to an upper portion of a cylinder block 001, and a water jacket (not shown) is formed inside. A cooling water supply passage 006 and a cooling water discharge passage 007 are provided between the water inlet 003 and the water outlet 004 of the cylinder block 001 and the radiator 005. A thermostat valve 008 and a water pump 009 are provided in the water inlet 003. Is installed. The cylinder block 001 is connected to a throttle body 011, a heater core 012, an ATF warmer 013, and a turbocharger 014 via a cooling water passage 010, and these are connected to a water outlet 004 via a cooling water passage 015. ing.

  Therefore, when the water pump 009 is driven, the cooling water flows from the cylinder block 001 to the cylinder head 002 to cool them, and then flows to the throttle body 011 and the turbocharger 014 to cool them, while the ATF warmer 013 It flows and sets ATF, flows to the heater core 012 and is used for heating, and is returned to the water outlet 004.

  By the way, an exhaust collecting passage is formed by joining a plurality of exhaust ports provided in communication with the plurality of combustion chambers in the cylinder head, and a turbocharger is connected to the exhaust collecting passage so that a turbocharger is connected to the cylinder head. There is an internal combustion engine in which a feeder can be directly attached. In this case, because the engine body is likely to be at a high temperature due to the exhaust gas flowing through each exhaust port and the exhaust collecting passage, the cylinder head is formed with a plurality of water jackets around the exhaust port and the exhaust collecting passage, Increases cooling efficiency.

  As an internal combustion engine in which the exhaust manifold is integrally formed in such a cylinder head and an exhaust manifold provided separately from the engine is eliminated, there is, for example, one described in Patent Document 1 below.

Japanese Patent No. 2709815

  In the conventional internal combustion engine cooling apparatus described above, cooling water is supplied from the cylinder block 001 to the cylinder head 002 to cool them, and then is supplied to the throttle body 011 and the turbocharger 014 to cool them. In a general internal combustion engine, a purification catalyst is provided in an exhaust system, and this purification catalyst efficiently purifies harmful substances in the exhaust gas when the exhaust gas is heated to a predetermined activation temperature region. be able to. For this reason, when the internal combustion engine is cold started, the purification catalyst is at a low temperature. Therefore, it is necessary to heat the purification catalyst with exhaust gas and to warm it up to the activation temperature range early. However, in an internal combustion engine having a turbocharger, as described above, the heat capacity of the turbocharger is large, and the cooling water flows to the turbocharger 014 (turbine). In other words, it is lost by the cooling water, and it takes a long time to warm up the purification catalyst, resulting in a reduction in exhaust purification efficiency.

  Further, in an internal combustion engine in which an exhaust collecting passage is integrally formed with the cylinder head, when the exhaust gas flows through the exhaust collecting passage, the cooling water flows through the water jacket formed around the exhaust collecting passage. Therefore, it takes a long time to warm up the purification catalyst, and the exhaust purification efficiency decreases.

  The present invention is intended to solve such a problem, and provides a cooling device for an internal combustion engine that improves exhaust purification performance by efficiently using heat recovered from exhaust gas. Objective.

  In order to solve the above-described problems and achieve the object, the cooling device for an internal combustion engine according to the present invention includes a cylinder head fastened to an upper portion of a cylinder block, and pistons movably supported by a plurality of cylinder bores. A plurality of combustion chambers are partitioned, a plurality of intake ports communicating with the respective combustion chambers are formed in the cylinder head, a plurality of exhaust ports communicating with the combustion chambers, and an exhaust assembly in which the plurality of intake ports merge In an internal combustion engine in which a passage is formed and a turbocharger is mounted, an intake-side cooling water passage that penetrates a peripheral portion of the intake port, a peripheral portion of the exhaust port, and the exhaust collecting passage are provided in the cylinder head. An exhaust side cooling water passage penetrating therethrough is formed, a first cooling water supply passage for supplying cooling water to the intake side cooling water passage is provided, and the exhaust side cooling water passage is provided. A second cooling water supply passage for supplying cooling water to the water passage is provided, and a third cooling water supply passage for supplying the cooling water in the exhaust-side cooling water passage to the cooling water passage of the turbocharger is provided. It is characterized by this.

  In the cooling device for an internal combustion engine according to the present invention, a cooling water return passage for returning the cooling water in the cooling water passage of the turbocharger to the exhaust-side cooling water passage is provided.

  In the cooling device for an internal combustion engine according to the present invention, a cooling water circulation line for circulating a cooling medium between the intake-side cooling water passage and the radiator is provided, and the cooling water in the cooling water passage of the turbocharger is cooled. A cooling water discharge passage for discharging to the water circulation line is provided, and a control valve for switching the communication cutoff state of the cooling water return passage and the cooling water discharge passage with respect to the cooling water passage of the turbocharger is provided. The control valve can be switched and controlled in accordance with the operating state of the internal combustion engine.

  In the cooling device for an internal combustion engine according to the present invention, a cooling water temperature detection sensor for detecting a temperature of the cooling water flowing through the cooling water circulation line is provided, and the control means detects the temperature of the cooling water detected by the cooling water temperature detection means. Is determined to be cold start of the internal combustion engine when the temperature is lower than a preset warm-up completion temperature, and the control valve communicates the cooling water passage and the cooling water return passage of the turbocharger, The cooling water passage of the turbocharger and the cooling water discharge passage are shut off.

  In the cooling device for an internal combustion engine of the present invention, a cooling water circulation line for circulating a cooling medium between the intake-side cooling water passage and the radiator is provided, and a water pump is provided in the cooling water circulation line. The cooling water flowing through the cooling water circulation line is supplied from the first cooling water supply passage to the intake-side cooling water passage without mixing the cooling water flowing through the cooling water circulation line and the cooling water in the cooling water return passage. On the other hand, the cooling water in the cooling water return passage is supplied from the second cooling water supply passage to the exhaust side cooling water passage.

  According to the cooling device for an internal combustion engine of the present invention, the intake side cooling water passage and the exhaust side cooling water passage are formed in the cylinder head, and the first cooling water supply passage for supplying the cooling water to the intake side cooling water passage is provided. The second cooling water supply passage for supplying the cooling water to the exhaust side cooling water passage is provided, and the third cooling water supply passage for supplying the cooling water in the exhaust side cooling water passage to the cooling water passage of the turbocharger is provided. Therefore, the cooling water flowing through the exhaust-side cooling water passage is efficiently heated by the exhaust gas passing through the plurality of exhaust ports and the exhaust collecting passage and becomes a high temperature, and the high-temperature cooling water is discharged from the third cooling water supply passage. Since the turbocharger is supplied to the cooling water passage of the turbocharger, the turbocharger is quickly heated by the high-temperature cooling water, and the heat of the exhaust gas is suppressed from being greatly deprived by the turbocharger. Effective purification catalyst with gas Well heated can enable early activation, a result, it is possible to improve the exhaust purification performance by utilizing the heat recovered from the exhaust gas efficiently.

  Embodiments of a cooling apparatus for an internal combustion engine according to the present invention will be described below in detail with reference to the drawings. In addition, this invention is not limited by this Example.

  FIG. 1 is a schematic configuration diagram illustrating a cooling device for an internal combustion engine according to a first embodiment of the present invention, FIG. 2 is a schematic configuration diagram of an engine to which the cooling device for an internal combustion engine according to the first embodiment is applied, and FIG. 1 is a longitudinal sectional view of an engine to which a cooling device for an internal combustion engine of Example 1 is applied.

  In the engine to which the cooling device for the internal combustion engine of the first embodiment is applied, as shown in FIGS. 2 and 3, this engine is a water-cooled in-line four-cylinder engine, and a cylinder head 12 is fastened to the upper part of the cylinder block 11. The cylinder block 11 has four cylinders (cylinder bores) 13 formed in series. Pistons 14 are fitted in four cylinder bores 13 formed in the cylinder block 11 so as to be movable up and down, and are connected to a crankshaft (not shown) via a connecting rod 15.

  The combustion chamber 16 is defined by the cylinder bore 13, the lower surface of the cylinder head 12, and the top surface of the piston 14. An intake port 17 and an exhaust port 18 are formed facing the upper portion of the combustion chamber 16, that is, the lower surface of the cylinder head 12, and an intake valve 19 and an exhaust valve 20 are provided to the intake port 17 and the exhaust port 18. Each is located. The intake valve 19 and the exhaust valve 20 are supported by the cylinder head 12 so as to be movable in the axial direction, and the valve springs 21 and 22 close the intake port 17 and the exhaust port 18 (in FIG. 3). The upper side is biased and supported. An intake camshaft 23 and an exhaust camshaft 24 are rotatably supported on the upper part of the cylinder head 12. An intake cam 25 and an exhaust cam provided integrally with the intake camshaft 23 and the exhaust camshaft 24. 26 can drive the intake valve 19 and the exhaust valve 20.

  Accordingly, when the intake camshaft 23 and the exhaust camshaft 24 rotate in synchronization with the engine, the intake cam 25 and the exhaust cam 26 move the intake valve 19 and the exhaust valve 20 up and down at a predetermined timing. The exhaust port 18 can be opened and closed to allow the intake port 17 and the combustion chamber 16 to communicate with the combustion chamber 16 and the exhaust port 18.

  A surge tank 28 is connected to the intake port 17 of the cylinder head 12 via an intake manifold 27. On the other hand, an air cleaner 30 is attached to an air intake port of the intake pipe 29, and an electronic throttle device 31 having a throttle valve is provided in the intake pipe 29 and is located downstream of the air cleaner 30. The downstream end of the intake pipe 29 is connected to the surge tank 28.

  The exhaust port 18 communicates with an exhaust collecting passage 32 where exhaust gas discharged from the combustion chamber 16 collects, and an exhaust pipe 33 is connected to the exhaust collecting passage 32. In this case, the exhaust port 18 and the exhaust collecting passage 32 are integrally formed in the cylinder head 12. A three-way catalyst 34 is attached to the exhaust pipe 33.

  The engine of this embodiment is provided with a turbocharger 35. The turbocharger 35 is configured by integrally connecting a compressor 36 provided on the intake pipe 29 side and a turbine 37 provided on the exhaust pipe 33 side by a connecting shaft 38. An intercooler 39 that cools intake air that has been compressed by the compressor 36 and that has risen in temperature is disposed in the intake pipe 29 downstream of the compressor 36 in the turbocharger 35 and upstream of the electronic throttle device 31. Is provided.

  An injector 40 that injects fuel into the intake port 17 is attached to the cylinder head 12, and at the center of the ceiling of the combustion chamber 16, that is, on the lower surface of the cylinder head 12 between each intake port 17 and each exhaust port 18. A spark plug 41 is attached. The vehicle is equipped with an electronic control unit (ECU) that can control and detect the fuel injection amount and fuel injection timing by the injector 40, the ignition timing by the spark plug 41, and the like. The fuel injection amount, fuel injection timing, ignition timing, and the like are determined based on the engine operating state such as the intake air amount, throttle opening (accelerator opening), and engine speed.

  The cylinder block 11 is formed with a water jacket 51 located around each cylinder (cylinder bore) 13, while the cylinder head 12 has an intake side water jacket (intake air) penetrating the peripheral portion of the intake port 17. Side cooling water passage) 52 and an exhaust side water jacket (exhaust side cooling water passage) 53 penetrating the periphery of the exhaust port 18 and the exhaust collecting passage 32 are formed. The intake-side water jacket 52 is formed below the intake port 17 and communicates with the water jacket 51 of the cylinder block 11. On the other hand, the exhaust-side water jacket 53 is formed above and below the exhaust port 18 and the exhaust collecting passage 32.

  In the internal combustion engine cooling apparatus according to the first embodiment applied to the engine configured as described above, as shown in FIG. 1, there is a first gap between the water inlet 61 and the radiator 62 in the water jacket 51 of the cylinder block 11. A first coolant circulation passage 63 is provided, and a second coolant circulation passage 65 is provided between the water outlet 64 of the cylinder head 12 and the radiator 62. A thermostat valve 66 is provided adjacent to the water inlet 61 and the water outlet 64 to which the first cooling water circulation passage 63 is connected, and a water pump 67 is mounted adjacent to the thermostat valve 66. The water pump 67 is connected to the inlet portion of the water jacket 51 of the cylinder block 11 via the first cooling water supply passage 68 and is connected to the exhaust side water of the cylinder head 12 via the second cooling water supply passage 69. It is connected to the entrance of the jacket 53.

  Accordingly, by driving the water pump 67, the cooling water is supplied to the water jacket 51 of the cylinder block 11 through the first cooling water supply passage 68, and is supplied from the water jacket 51 to the intake side water jacket 52 of the cylinder head 12. be able to. Further, by driving the water pump 67, the cooling water can be supplied to the exhaust-side water jacket 53 of the cylinder head 12 through the second cooling water supply passage 69.

  A cooling water passage (not shown) of the turbocharger 35 is connected to an outlet of the exhaust-side water jacket 53 of the cylinder head 12 via a third cooling water supply passage 70. On the other hand, the cooling water passages (not shown) of the throttle body 72, the heater core 73, and the ATF warmer 74 are connected to the outlet portion of the intake water jacket 52 of the cylinder head 12 via the fourth cooling water supply passage 71. Yes. The cooling water passage of the turbocharger 35 is connected to the water outlet 64 via the cooling water discharge passage 75, and the cooling water passages of the throttle body 72, the heater core 73, and the ATF warmer 74 are connected to the cooling water discharge passage 76. It is connected to the water outlet 64 via the.

  The cooling water passage of the turbocharger 35 is formed in the turbine housing so that the turbine 37 and the connecting shaft 38 can be cooled. Further, the cooling water passage of the throttle body 72 is formed in the periphery thereof so that the throttle valve can be cooled. The heater core 73 uses cooling water (hot water) as a heat source for heating, and is provided in a passage through which the blower fan winds flow. The ATF warmer 74 is attached to the automatic transmission so as to cool the warm air of the automatic transmission.

  Therefore, the cooling water that has flowed through the exhaust-side water jacket 53 is supplied to the cooling water passage of the turbocharger 35 via the third cooling water supply passage 70 and returned to the water outlet 64 via the cooling water discharge passage 75. It is. On the other hand, the cooling water that has flowed through the intake water jacket 52 is supplied to the cooling water passages of the throttle body 72, the heater core 73, and the ATF warmer 74 through the fourth cooling water supply passage 71, and through the cooling water discharge passage 76. And returned to the water outlet 64.

  The thermostat valve 66 described above opens and closes according to the temperature of the cooling water. Accordingly, when the temperature of the cooling water is low, such as immediately after starting the engine, and below a predetermined temperature set in advance, the cooling water is not circulated to the radiator 62 by the thermostat valve 66 but returned to the engine side through a bypass passage not shown. Promote warm-up. When a predetermined time has elapsed from the start of the engine and the temperature of the cooling water becomes higher than the predetermined temperature, the thermostat valve 66 is switched to flow the cooling water to the radiator 62 to promote cooling.

  In this embodiment, the cooling water circulation line is constituted by the radiator 62, the cooling water circulation passages 63 and 65, the cooling water supply passages 68, 69, 70, 71, the water jackets 51, 53, 54, and the cooling water discharge passages 75, 76. It is configured.

  When the engine is started in the cooling apparatus for an internal combustion engine of the present embodiment configured as described above, the water pump 67 is activated, and the cooling water passes through the first cooling water supply passage 68 and the water jacket 51 of the cylinder block 11. And the cooling water is supplied to the exhaust-side water jacket 53 of the cylinder head 12 through the second cooling water supply passage 69. Then, the cooling water supplied to the exhaust-side water jacket 53 flows through this, and then supplied to the cooling water passage of the turbocharger 35 through the third cooling water supply passage 70 and through the cooling water discharge passage 75 to the water outlet. Return to 64. On the other hand, the cooling water supplied to the water jacket 51 flows through the water jacket 51 and then is supplied to the intake-side water jacket 52 of the cylinder head 12. After flowing through the cooling water, the throttle body 72, The water is supplied to the cooling water passages of the heater core 73 and the ATF warmer 74 and returned to the water outlet 64 through the cooling water discharge passage 76.

  At this time, the water pump 67 supplies the cooling water to the water jacket 51 of the cylinder block 11 and the intake-side water jacket 52 of the cylinder head 12 through the first cooling water supply passage 68 and also passes through the second cooling water supply passage 69. The coolant supplied separately to the exhaust-side water jacket 53 of the cylinder head 12 and heated to flow through the exhaust-side water jacket 53 is heated by flowing therethrough, and then is supplied to the turbocharger through the third coolant supply passage 70. It is supplied to the cooling water passage of the feeder 35. Therefore, the cooling water flowing through the exhaust-side water jacket 53 is effectively heated by receiving the heat of the high-temperature exhaust gas passing through the exhaust ports 18 and the exhaust collecting passages 32 in the vicinity thereof, and becomes a high temperature. This turbocharger 67 is warmed up early.

  When the engine is cold started and the temperature of the cooling water is equal to or lower than the predetermined temperature, the thermostat valve 66 returns the cooling water returned to the water outlet 64 to the engine side without circulating it to the radiator 62. Are switched as follows. Therefore, the cooling water returned to the water outlet 64 is again supplied to the water jacket 51 and the intake-side water jacket 52 through the first cooling water supply passage 68 by the water pump 67 and the second cooling water supply passage 69. The engine is supplied to the exhaust-side water jacket 53 through the engine and warming up of the engine is promoted.

  Thereafter, when the engine is warmed up and the temperature of the cooling water becomes higher than a predetermined temperature, the thermostat valve 66 is switched, and the cooling water returned to the water outlet 64 is circulated to the radiator 62 through the first cooling water circulation passage 65. The high-temperature cooling water is cooled by the radiator 62 and returned to the water inlet 61 through the second cooling water circulation passage 63. In the same manner as described above, the water pump 67 supplies the water jacket 51 and the intake water jacket 52 through the first cooling water supply passage 68 and supplies the exhaust water jacket 53 through the second cooling water supply passage 69. As a result, cooling of the engine is promoted.

  As described above, in the internal combustion engine cooling apparatus according to the first embodiment, the water jacket 51 is formed in the cylinder block 11 and the intake-side water jacket 52 penetrating the peripheral portion of the intake port 17 is formed in the cylinder head 12. The exhaust water jacket 53 is formed so as to communicate with the water jacket 51 and penetrate the periphery of the exhaust port 18 and the exhaust collecting passage 32, and the water pump 67 supplies the cooling water via the first cooling water supply passage 68. While it is possible to supply the water jacket 51 and the intake water jacket 52 to the exhaust water jacket 53 via the second cooling water supply passage 69, the cooling water of the exhaust water jacket 53 is third cooled. The water can be supplied to the cooling water passage of the turbocharger 35 via the water supply passage 70.

  Accordingly, the cooling water flowing through the exhaust-side water jacket 53 is efficiently heated to high temperature by the exhaust gas passing through the plurality of exhaust ports 18 and the exhaust collecting passage 32, and this high-temperature cooling water is supplied to the third cooling water supply. In order to supply the cooling water passage of the turbocharger 35 from the passage 70, the turbocharger 35 is heated early by the high-temperature cooling water, and the heat of the exhaust gas is greatly deprived by the turbocharger 35. Therefore, the three-way catalyst 34 can be efficiently heated by the exhaust gas to enable early activation. As a result, the heat recovered from the exhaust gas can be efficiently used to improve the exhaust purification performance. Improvements can be made.

  FIG. 4 is a schematic configuration diagram illustrating a cooling device for an internal combustion engine according to a second embodiment of the present invention. The overall configuration of the cooling apparatus for an internal combustion engine according to the present embodiment is substantially the same as that of the first embodiment described above, and will be described with reference to FIGS. 2 and 3 and functions similar to those described in this embodiment. The same reference numerals are given to the members having, and duplicate explanations are omitted.

  In the cooling apparatus for an internal combustion engine according to the first embodiment, as shown in FIG. 4, a first coolant circulation passage 63 is provided between the water inlet 61 and the radiator 62, and the first cooling water circulation path 63 is provided between the water outlet 64 and the radiator 62. Two cooling water circulation passages 65 are provided. A thermostat valve 66 is provided adjacent to the water inlet 61 and the water outlet 64, and a water pump 67 is mounted adjacent to the thermostat valve 66. The water pump 67 is connected to the inlet portion of the water jacket 51 of the cylinder block 11 via the first cooling water supply passage 68 and is connected to the exhaust side water of the cylinder head 12 via the second cooling water supply passage 69. It is connected to the entrance of the jacket 53.

  The outlet of the exhaust water jacket 53 of the cylinder head 12 is connected to the cooling water passage of the turbocharger 35 via the third cooling water supply passage 70. On the other hand, the outlet of the intake water jacket 52 of the cylinder head 12 is connected to the cooling water passages of the throttle body 72, the heater core 73, and the ATF warmer 74 through the fourth cooling water supply passage 71. The cooling water passage of the turbocharger 35 is connected to a control valve 82 via a connection passage 81, and the control valve 82 is connected to a water pump 67 (second cooling water supply passage) via a cooling water return passage 83. 69) and also connected to a water outlet 64 (cooling water circulation line) via a cooling water discharge passage 84. The cooling water passages of the throttle body 72, the heater core 73, and the ATF warmer 74 are connected to the water outlet 64 via the cooling water discharge passage 76.

  The above-described control valve 82 switches the communication cutoff state of the cooling water return passage 83 and the cooling water discharge passage 84 with respect to the cooling water passage of the turbocharger 35, and can be switched according to the operating state of the engine. It has become.

  Specifically, the water jacket 51 of the cylinder block 11 is provided with a cooling water temperature detection sensor 85 that detects the temperature of the cooling water, and the ECU 86 is based on the temperature of the cooling water detected by the cooling water temperature detection sensor 85. The control valve 82 is switched and controlled. That is, the ECU 86 determines that the engine is cold-started when the temperature of the cooling water detected by the cooling water temperature detection sensor 85 is lower than a preset warm-up completion temperature, and the turbocharger is controlled by the control valve 82. The cooling water passage 35 and the cooling water return passage 83 communicate with each other, while the cooling water passage and the cooling water discharge passage 84 of the turbocharger 35 are blocked. On the other hand, when the temperature of the cooling water detected by the cooling water temperature detection sensor 85 is higher than the preset warm-up completion temperature, the ECU 86 determines that the cold start of the engine has been completed, and the control valve 82 performs turbocharging. The cooling water passage and the cooling water return passage 83 of the machine 35 are blocked, while the cooling water passage and the cooling water discharge passage 84 of the turbocharger 35 are communicated.

  Further, in this embodiment, the water pump 67 can supply the cooling water from the water outlet 64 (cooling water circulation line) and the cooling water from the control valve 82 and the cooling water return passage 83 without mixing them. Two supply parts 67a and 67b are provided. That is, the cooling water from the water outlet 64 can be supplied to the water jacket 51 and the intake-side water jacket 52 through the first cooling water supply passage 68 by the first supply portion 67 a of the water pump 67, and from the cooling water return passage 83. This cooling water can be supplied from the second cooling water supply passage 69 to the exhaust-side water jacket 53 by the second supply part 67 b of the water pump 67.

  When the engine is started in the cooling apparatus for an internal combustion engine of the present embodiment configured as described above, the water pump 67 is activated, and the first supply portion 67a causes the cooling water to pass through the first cooling water supply passage 68 to the cylinder. While being supplied to the water jacket 51 of the block 11, the cooling water is supplied to the exhaust-side water jacket 53 of the cylinder head 12 through the second cooling water supply passage 69 by the second supply part 67 b. Then, the cooling water supplied to the exhaust-side water jacket 53 flows through this, and then supplied to the cooling water passage of the turbocharger 35 through the third cooling water supply passage 70. Here, the ECU 86 switches and controls the control valve 82 based on the cooling water temperature detected by the cooling water temperature detection sensor 85, and the cooling water in the cooling water passage of the turbocharger 35 passes through the cooling water return passage 83. It is returned to the water pump 67 or returned to the water outlet 64 through the cooling water discharge passage 84. On the other hand, the cooling water supplied to the water jacket 51 flows through the water jacket 51 and then is supplied to the intake-side water jacket 52 of the cylinder head 12. After flowing through the cooling water, the throttle body 72, The water is supplied to the cooling water passages of the heater core 73 and the ATF warmer 74 and returned to the water outlet 64 through the cooling water discharge passage 76.

  At this time, the coolant supplied to the exhaust-side water jacket 53 is heated by flowing therethrough and then supplied to the coolant passage of the turbocharger 35 through the third coolant supply passage 70. Therefore, the cooling water flowing through the exhaust-side water jacket 53 is effectively heated by receiving the heat of the high-temperature exhaust gas passing through the exhaust ports 18 and the exhaust collecting passages 32 in the vicinity thereof, and becomes a high temperature. The turbocharger 35 is warmed up early.

  Further, when the engine is cold started and the temperature of the cooling water detected by the cooling water temperature detection sensor 85 is lower than the warm-up completion temperature, the ECU 86 determines that the engine is cold started, and the control valve 82 The cooling water passage and the cooling water return passage 83 of the turbocharger 35 are communicated, and the cooling water passage and the cooling water discharge passage 84 of the turbocharger 35 are blocked. Then, the cooling water in the cooling water passage of the turbocharger 35 is returned to the water pump 67 through the cooling water return passage 83, and the second supply part 67 b of the water pump 67 is cooled by the cooling water return passage 83. Water is supplied to the exhaust-side water jacket 53 through the second cooling water supply passage 69 without being mixed with the cooling water from the water outlet 64. Therefore, the high-temperature cooling water is circulated between the exhaust water jacket 53 and the cooling water passage of the turbocharger 35, and the conduction of the cooling water to the peripheral members is suppressed to reduce the cooling water heat. This cooling water is heated efficiently by minimizing.

  Thereafter, when the engine is warmed up and the temperature of the cooling water detected by the cooling water temperature detection sensor 85 becomes higher than the warm-up completion temperature, the ECU 86 determines that the cold start of the engine has been completed, and the control valve 82 turbocharges the engine. The cooling water passage and the cooling water return passage 83 of the machine 35 are blocked, while the cooling water passage and the cooling water discharge passage 84 of the turbocharger 35 are communicated. Then, the cooling water in the cooling water passage of the turbocharger 35 is discharged to the water outlet 64 through the cooling water discharge passage 84. When the temperature of the cooling water becomes higher than the predetermined temperature, the thermostat valve 66 is switched, and the cooling water returned to the water outlet 64 is circulated to the radiator 62 through the second cooling water circulation passage 65, so that the high-temperature cooling water Is cooled by the radiator 62 and returned to the water inlet 61 through the second cooling water circulation passage 63. In the same manner as described above, the water pump 67 supplies the water jacket 51 and the intake water jacket 52 through the first cooling water supply passage 68 and supplies the exhaust water jacket 53 through the second cooling water supply passage 69. As a result, cooling of the engine is promoted.

  Thus, in the internal combustion engine cooling apparatus according to the second embodiment, the water pump 67 can supply the cooling water to the water jacket 51 and the intake-side water jacket 52 through the first cooling water supply passage 68. The exhaust water jacket 53 can be supplied to the exhaust water jacket 53 via the second cooling water supply passage 69, and the cooling water of the exhaust water jacket 53 can be supplied to the cooling water passage of the turbocharger 35 via the third cooling water supply passage 70. In addition, the cooling water in the cooling water passage of the turbocharger 35 can be returned to the exhaust-side water jacket 53 via the cooling water return passage 83.

  Accordingly, the cooling water flowing through the exhaust-side water jacket 53 is efficiently heated to high temperature by the exhaust gas passing through the plurality of exhaust ports 18 and the exhaust collecting passage 32, and this high-temperature cooling water is supplied to the third cooling water supply. In order to supply the cooling water passage of the turbocharger 35 from the passage 70 and return to the exhaust water jacket 53 from the cooling water return passage 83, the cooling water is efficiently heated, and the turbocharger 35 is heated by the high-temperature cooling water. Heating of the exhaust gas can be suppressed early, the turbocharger 35 can be prevented from being greatly deprived of heat, and the exhaust gas can efficiently heat the three-way catalyst 34 to enable early activation. it can.

  Further, in this embodiment, a control valve 82 is provided for switching the communication cutoff state of the cooling water return passage 83 and the cooling water discharge passage 84 with respect to the cooling water passage of the turbocharger 35, and the ECU 86 is in accordance with the engine operating state. The control valve 82 can be switched. Specifically, a cooling water temperature detection sensor 85 that detects the temperature of the cooling water is provided, and the ECU 86 detects that the temperature of the cooling water detected by the cooling water temperature detection sensor 85 is lower than a preset warm-up completion temperature. It is sometimes determined that the engine is cold start, and the control valve 82 communicates the cooling water passage and the cooling water return passage 83 of the turbocharger 35, while the cooling water passage and the cooling water discharge passage 84 of the turbocharger 35. And is to be cut off.

  Therefore, when the engine is cold-started, the cooling water that has warmed up the turbocharger 35 is returned to the water pump 67 from the cooling water return passage 83 and is supplied to the exhaust-side water jacket 53 again by the second supply portion 67b. Since the high-temperature cooling water is circulated only between the exhaust water jacket 53 and the cooling water passage of the turbocharger 35 and the temperature is efficiently raised while suppressing the temperature drop of the cooling water, the turbocharging The machine 35 can be warmed up early, and as a result, the three-way catalyst 34 can be overheated and activated early.

  Further, in this embodiment, the water pump 67 is provided with two supply portions 67a and 67b, and the cooling water supply passages 68 are mixed without mixing the cooling water from the water outlet 64 and the cooling water from the cooling water return passage 83. 69, 69 can be supplied to the intake water jacket 52 and the exhaust water jacket 53.

  Therefore, the cooling water from the water outlet 64 and the cooling water from the cooling water return passage 83 are not mixed, and the high-temperature cooling water is circulated between the exhaust water jacket 53 and the cooling water passage of the turbocharger 35. Accordingly, the conduction of the heat of the cooling water to the peripheral members is suppressed to minimize the decrease in the heat of the cooling water, and the cooling water is efficiently heated.

  As described above, the cooling apparatus for an internal combustion engine according to the present invention improves exhaust purification performance by efficiently using heat recovered from exhaust gas, and is applicable to any internal combustion engine. Is also useful.

1 is a schematic configuration diagram illustrating a cooling device for an internal combustion engine according to a first embodiment of the present invention. 1 is a schematic configuration diagram of an engine to which a cooling device for an internal combustion engine according to a first embodiment is applied. 1 is a longitudinal sectional view of an engine to which a cooling device for an internal combustion engine according to a first embodiment is applied. It is a schematic block diagram showing the cooling device of the internal combustion engine which concerns on Example 2 of this invention. It is a schematic block diagram showing the cooling device of the conventional internal combustion engine.

Explanation of symbols

11 Cylinder block 12 Cylinder head 13 Cylinder bore (cylinder)
16 Combustion chamber 17 Intake port 18 Exhaust port 32 Exhaust collecting passage 33 Exhaust pipe 34 Three-way catalyst 35 Turbocharger 51 Water jacket 52 Intake side water jacket (intake side cooling water passage)
53 Exhaust water jacket (exhaust cooling water passage)
62 Radiator 66 Thermostat valve 67 Water pump 68 First cooling water supply passage 69 Second cooling water supply passage 70 Third cooling water supply passage 75, 76, 84 Cooling water discharge passage 82 Control valve 83 Cooling water return passage 85 Cooling water temperature Detection sensor 86 Electric control unit, ECU (control means)

Claims (5)

  A cylinder head is fastened to the upper part of the cylinder block, and a plurality of combustion chambers are defined by pistons being movably supported by a plurality of cylinder bores, and a plurality of intake ports communicating with the respective combustion chambers are provided in the cylinder head. In the internal combustion engine in which a plurality of exhaust ports communicating with the combustion chamber and an exhaust collecting passage where the plurality of intake ports merge are formed and a turbocharger is mounted, the cylinder head includes the intake air An intake-side cooling water passage that penetrates the periphery of the port and an exhaust-side cooling water passage that penetrates the periphery of the exhaust port and the exhaust collecting passage are formed to supply cooling water to the intake-side cooling water passage. A cooling water supply passage is provided, a second cooling water supply passage is provided for supplying cooling water to the exhaust side cooling water passage, and the exhaust side cooling water passage is provided. A cooling apparatus for an internal combustion engine, wherein a coolant third the cooling water supply passage is provided for supplying the cooling water passages of the turbocharger of the internal.   2. The cooling apparatus for an internal combustion engine according to claim 1, further comprising a cooling water return passage for returning the cooling water in the cooling water passage of the turbocharger to the exhaust-side cooling water passage. Cooling system.   The cooling device for an internal combustion engine according to claim 2, wherein a cooling water circulation line for circulating a cooling medium between the intake-side cooling water passage and the radiator is provided, and the cooling water in the cooling water passage of the turbocharger is provided. Is provided with a cooling water discharge passage for discharging the cooling water to the cooling water circulation line, and a control valve is provided for switching a communication cutoff state of the cooling water return passage and the cooling water discharge passage with respect to the cooling water passage of the turbocharger. A cooling device for an internal combustion engine, characterized in that the means can switch and control the control valve in accordance with the operating state of the internal combustion engine.   4. The cooling apparatus for an internal combustion engine according to claim 3, wherein a cooling water temperature detection sensor for detecting a temperature of the cooling water flowing through the cooling water circulation line is provided, and the control means is a cooling detected by the cooling water temperature detection means. When the temperature of water is lower than a preset warm-up completion temperature, it is determined that the internal combustion engine is cold-started, and the control valve communicates the cooling water passage and the cooling water return passage of the turbocharger. On the other hand, a cooling device for an internal combustion engine, wherein the cooling water passage and the cooling water discharge passage of the turbocharger are blocked.   5. The cooling device for an internal combustion engine according to claim 2, wherein a cooling water circulation line for circulating a cooling medium is provided between the intake-side cooling water passage and the radiator, and the cooling water circulation line is provided with water. A pump is provided, wherein the water pump does not mix the cooling water flowing through the cooling water circulation line and the cooling water in the cooling water return passage, and allows the cooling water flowing through the cooling water circulation line to flow through the first cooling water supply passage. A cooling device for an internal combustion engine, wherein the cooling water in the cooling water return passage is supplied from the second cooling water supply passage to the exhaust cooling water passage while being supplied to the intake side cooling water passage.

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