JP5708042B2 - V-type engine cooling system - Google Patents

Description

  The present invention relates to a cooling device for a V-type engine that cools a V-type engine mounted on a vehicle such as an automobile by circulating cooling water.

  In an engine (internal combustion engine) mounted on a vehicle such as an automobile, a so-called two-system cooling system cooling device in which a cooling water channel on the cylinder block side and a cooling water channel on the cylinder head side are provided independently of each other is known. It has been. In this type of cooling device, the cooling state on the cylinder block side and the cooling state on the cylinder head side can be controlled independently.

  Conventionally, a technique in which such a two-system cooling system cooling device is applied to a V-type engine has been proposed (see, for example, Patent Document 1). In the cooling device for the V-type engine described in Patent Document 1, a cooling water outlet communicating with a water jacket on the cylinder block side of the pair of banks is formed upward at a position between the banks at the rear end of the cylinder block. Has been. This simplifies the configuration of the V-type engine and shortens its overall length.

  However, Patent Document 1 does not describe an appropriate arrangement of an EGR cooler and a heat exchange device such as a heater core when a two-system cooling system cooling device is applied to a V-type engine, and EGR by an EGR cooler. There is room for improvement in terms of increasing the gas cooling efficiency and increasing the heating efficiency of the passenger compartment by the heater core.

JP 05-044661 A

  The present invention has been made in view of the above-described problems, and is a V-type engine that employs a two-system cooling system capable of efficiently operating a heat exchange device installed in a cooling water circulation circuit. An object is to provide a cooling device.

  In the present invention, means for solving the above-described problems are configured as follows. That is, the present invention includes a V-type engine mounted horizontally in a front portion of a vehicle, a water pump, a radiator, and a cooling water circulation circuit for circulating cooling water to these devices, and a cylinder block of the V-type engine Side cooling water flow path and cylinder head side cooling water flow path are provided independently of each other, and the cooling water circulation circuit has a type of heat exchange device that radiates heat to the cooling water. And a heat exchange device of the type that absorbs heat from the cooling water, and the heat exchange device of the type that dissipates heat to the cooling water includes a cooling on the cylinder head side of the front bank of the front and rear banks of the V-type engine. The heat exchange device of the type that is supplied with cooling water from the water flow path and absorbs heat from the cooling water includes a cylinder block in the rear bank of a pair of front and rear banks of the V-type engine. Tsu cooling water is characterized in that it is supplied from the click-side cooling water passage. Here, the heat exchange device refers to a device that cools a cooling target or heats a heating target by performing heat exchange with cooling water flowing through a cooling water circulation circuit. The radiator is not included in the heat exchange device referred to here.

  According to the above configuration, even when the V-type engine is warmed up, the coolant is actively circulated through the coolant flow path on the cylinder head side, so that the cylinder head is in a lower temperature state than the cylinder block. In addition, when the vehicle is traveling forward, the front bank of the V-type engine is located in front of the traveling wind, so that it is easy to be cooled by the traveling wind. Accordingly, the cylinder head in the front bank of the V-type engine is likely to be in the coldest state in the V-type engine. As a result, a type of heat exchange device that radiates heat to the cooling water by supplying the cooling water taken out from the cooling water flow path on the cylinder head side of the front bank (in other words, a type of heat exchange that cools the object to be cooled by the cooling water) Device) can be operated efficiently, and the cooling performance by the heat exchange device can be improved.

  On the other hand, during the warm-up of the V-type engine, the flow rate of the cooling water circulating in the cooling water flow path on the cylinder block side is limited, so that the cylinder block becomes hotter than the cylinder head. In addition, when the vehicle is traveling forward, the rear bank of the V-type engine is hard to receive the traveling wind and is likely to accumulate heat. Therefore, the cylinder block in the rear bank of the V-type engine is likely to be the hottest state in the V-type engine. Thereby, by supplying the cooling water taken out from the cooling water flow path on the cylinder block side of the rear bank, a heat exchange device of a type that absorbs heat from the cooling water (in other words, a type that heats the object to be heated by the cooling water). Heat exchange device) can be operated efficiently, and the heating performance of the heat exchange device can be improved.

  Therefore, according to the above configuration, the cooling water to the heat exchange device installed in the cooling water circulation circuit is utilized by utilizing the fact that the temperature difference generated in the V-type engine mounted horizontally in the front portion of the vehicle becomes large. Thus, the heat exchange device can be operated efficiently.

  In the V-type engine cooling apparatus of the present invention, the heat exchange device of the type that radiates heat to the cooling water is disposed on the front side of the front bank, and the heat exchange device of the type that absorbs heat from the cooling water is the rear side. It is preferable to arrange on the rear side of the bank.

  According to the said structure, the length of the piping of the cooling water from a V-type engine to a heat exchange device can be shortened.

  In the V-type engine cooling apparatus of the present invention, it is preferable that the flow rate of the cooling water circulated through the cooling water flow path on the cylinder block side is limited during the warm-up of the V-type engine.

  According to the said structure, warming-up of a cylinder block is accelerated | stimulated by restrict | limiting the flow volume of the cooling water circulated through the cooling water flow path by the side of a cylinder block. And by taking out the cooling water from the rear bank of the cylinder block in a high temperature state, it is possible to operate the heat exchange device that absorbs heat from the cooling water more efficiently, and the heating performance of the heat exchange device is sufficient. Can be demonstrated.

  In the V-type engine cooling apparatus of the present invention, it is preferable that cooling water is always circulated in the cooling water flow path on the cylinder head side during operation of the V-type engine.

  According to the said structure, a cylinder head is hold | maintained in a low-temperature state by always circulating a cooling water to the cooling water flow path by the side of a cylinder head. And by taking out the cooling water from the cylinder head of the front bank in the low temperature state, it is possible to operate the heat exchange device that radiates heat to the cooling water more efficiently, and the cooling performance of the heat exchange device is sufficiently It can be demonstrated.

  Here, examples of the type of heat exchange device that radiates heat to the cooling water include an EGR cooler provided in an EGR passage that recirculates a part of the exhaust gas flowing through the exhaust passage of the V-type engine to the intake passage. In this case, by supplying cooling water taken out from the cooling water flow path on the cylinder head side of the front bank to the EGR cooler, the EGR cooler can be operated efficiently and the cooling performance of the EGR cooler can be sufficiently exhibited. The cooling efficiency of the EGR gas by the EGR cooler can be increased.

  Examples of the heat exchange device that absorbs heat from the cooling water include a heater core for heating the passenger compartment. In this case, by supplying the cooling water taken out from the cooling water flow path on the cylinder block side of the rear bank to the heater core, the heater core can be operated efficiently and the heating performance of the heater core can be sufficiently exhibited. The heating efficiency of the passenger compartment can be increased.

  According to the cooling apparatus for a V-type engine of the present invention, heat exchange installed in the cooling water circulation circuit is performed by utilizing the fact that the temperature difference generated in the V-type engine mounted horizontally in the front portion of the vehicle increases. By supplying the cooling water to the device, the heat exchange device can be operated efficiently.

It is a schematic block diagram which shows an example which has arrange | positioned the cooling device of the V-type engine which concerns on embodiment of this invention in the vehicle front part. It is a figure which shows typically the cooling water circulation circuit of the cooling device of the V-type engine of FIG. FIG. 3 is a diagram showing the flow of cooling water when the cooling water temperature is equal to or lower than a second switching temperature in the V-type engine cooling device of FIG. FIG. 3 is a diagram showing a flow of cooling water when the cooling water temperature is higher than a second switching temperature and equal to or lower than a first switching temperature in the cooling device for the V-type engine of FIG. 2. FIG. 3 is a diagram illustrating a flow of cooling water when the cooling water temperature is higher than a first switching temperature in the V-type engine cooling device of FIG. 2. It is a figure which shows typically the cooling water circulation circuit of the cooling device of the V-type engine which concerns on other embodiment.

  Embodiments of the present invention will be described with reference to the accompanying drawings.

  Below, the example which applied this invention to the cooling device of the V-type engine which cools the V-type engine mounted in vehicles, such as a motor vehicle, by circulation of a cooling water is demonstrated. An example in which the present invention is applied to a two-system cooling system cooling device in which the cooling water flow path on the cylinder block side and the cooling water flow path on the cylinder head side of the V-type engine are independent from each other will be described.

  As shown in FIG. 1, the cooling device for the V-type engine of this example is disposed at the front portion of the vehicle 1. A V-type engine cooling device includes a V-type engine 10, a water pump 30, a radiator 40 (see FIG. 2), an EGR (Exhaust Gas Recirculation) cooler 50, a heater core 60, and cooling water (for example, LLC: Long Life). A cooling water circulation circuit 100 for circulating Coolant) is provided.

  A V-type engine (hereinafter, also simply referred to as “engine”) 10 is mounted horizontally in an engine room provided at the front portion of the vehicle 1 as shown in FIG. That is, the engine 10 is arranged such that the crankshaft as the output shaft extends in parallel with the vehicle width direction.

  The engine 10 has a pair of banks 12 </ b> F and 12 </ b> R protruding in a V shape at the upper part of the cylinder block 11. As described above, since the engine 10 is arranged horizontally, one bank (hereinafter also referred to as “front-side bank”) 12F disposed on the front side of the pair of banks 12F and 12R is inclined frontward. The other bank (hereinafter also referred to as a “rear bank”) 12R provided to be inclined to the rear side is provided to be inclined rearward. Each bank 12F, 12R includes a cylinder head 14F, 14R attached to the upper end of the cylinder block 11. The cylinder block 11 is provided with a plurality of cylinders 13F and 13R (for example, three for each bank 12F and 12R) (see FIG. 2). The cylinders 13F and 13R of the banks 12F and 12R are arranged with a predetermined sandwich angle (for example, 60 °) in a side view. Although not shown, pistons are accommodated in the cylinders 13F and 13R so as to be able to reciprocate, and the pistons are connected to a crankshaft via connecting rods so that power can be transmitted.

  A crankcase 15 is attached to the lower side of the cylinder block 11. Further, an oil pan (not shown) for storing engine oil for lubricating and cooling each part of the engine 10 is provided at the lower part of the crankcase 15.

  In the cylinder block 11, water jackets 17F and 17R as cooling water flow paths are formed (see FIG. 2). The water jackets 17F and 17R are individually provided for the banks 12F and 12R, and are provided so as to surround the cylinders 13F and 13R of the banks 12F and 12R.

  Also, water jackets 18F and 18R as cooling water flow paths are formed inside the cylinder heads 14F and 14R (see FIG. 2). The water jackets 18F and 18R are individually provided for the cylinder heads 14F and 14R of the banks 12F and 12R.

  The water pump 30 is for generating a water flow in the cooling water circulation circuit 100 and is driven by the rotation of the crankshaft of the engine 10 as a power source. The water pump 30 supplies cooling water to the water jackets 17F and 17R of the cylinder block 11 and the water jackets 18F and 18R of the cylinder heads 14F and 14R, respectively. Although not shown, the water pump 30 is disposed on the side of the engine 10, and a transmission belt is provided between a water pump pulley provided on the drive shaft of the water pump 30 and a crank pulley provided on the crankshaft. Is over.

  The radiator 40 is of a down flow type, for example, and is configured to include a radiator core between the upper tank and the lower tank. The cooling water that has flowed into the upper tank of the radiator 40 exchanges heat with the outside air (running air or air blown by a cooling fan) when flowing down the radiator core toward the lower tank. And cooling water is cooled by radiating heat to the outside air. The radiator 40 is disposed at a front portion in the engine room of the vehicle 1.

  The EGR cooler 50 is a heat exchange device for cooling the EGR gas by performing heat exchange between the cooling water and the EGR gas. The EGR cooler 50 is disposed in an EGR passage that recirculates a part of the exhaust gas flowing through the exhaust passage of the engine 10 to the intake passage. By cooling the EGR gas by the EGR cooler 50, the density is lowered and the reduction of the combustion temperature due to the recirculation of the EGR gas is promoted. In this embodiment, the EGR cooler 50 is disposed on the front side of the front bank 12F of the engine 10 as shown in FIG.

  The heater core 60 is a heat exchange device for heating the vehicle interior by causing heat exchange between the cooling water and the conditioned air. The heater core 60 is disposed facing a blower duct of an air conditioner (not shown). That is, when heating the vehicle interior, the conditioned air flowing in the air duct is passed through the heater core 60 and supplied as warm air to the vehicle interior, while at other times (for example, during cooling), the heater core 60 is bypassed. Air conditioned air is sent into the passenger compartment. In this embodiment, the heater core 60 is disposed on the rear side of the rear bank 12R of the engine 10, as shown in FIG.

  Next, the cooling water circulation circuit 100 provided in the cooling device for the V-type engine will be described.

  As shown in FIG. 2, the cooling water circuit 100 includes a radiator circuit (first circulation path) 101, a bypass circuit (second circulation path) 102, and an EGR cooler circuit (first circuit) as circulation paths for circulating the cooling water. 3 circulation paths) 103 and a heater circuit (fourth circulation path) 104 are provided. One water pump 30 is used for cooling water circulation of the radiator circuit 101, the bypass circuit 102, the EGR cooler circuit 103, and the heater circuit 104.

  The radiator circuit 101 serves as a circulation path for circulating cooling water via the water jackets 17F, 17R, 18F, and 18R of the engine 10, the radiator 40, and the water pump 30. The bypass circuit 102 is a circulation path for circulating the cooling water via the water jackets 17F, 17R, 18F, and 18R of the engine 10, the bypass flow path 120, and the water pump 30. The EGR cooler circuit 103 is a circulation path for circulating cooling water via the water jacket 18F of the cylinder head 14F of the front bank 12F of the engine 10, the EGR cooler 50, and the water pump 30. The heater circuit 104 is a circulation path for circulating the coolant through the water jacket 17R, the heater core 60, and the water pump 30 of the cylinder block 11 of the rear side bank 12R of the engine 10. The cooling water circulation in each of the circuits 101 to 104 will be described later.

  In this embodiment, a two-system cooling system is employed in which cooling water is circulated in parallel between the water jackets 17F and 17R of the cylinder block 11 of the engine 10 and the water jackets 18F and 18R of the cylinder heads 14F and 14R. That is, the cooling state on the cylinder block 11 side and the cooling state on the cylinder heads 14F, 14R side can be controlled independently. In addition, in this embodiment, cooling water is circulated in parallel to the water jackets 17F and 17R of the cylinder block 11. Further, cooling water is circulated in parallel to the water jackets 18F and 18R of the cylinder heads 14F and 14R.

  Specifically, the discharge flow path 111 that communicates with the discharge port side of the water pump 30 includes a block side flow path 112 that communicates with the water jackets 17F and 17R side of the cylinder block 11 of the engine 10 and cylinder heads 14F and 14R. It is branched into a head side flow path 113 communicating with the water jackets 18F, 18R. A first thermostat 70 is disposed in the middle of the block side flow path 112.

  The cooling water inlets 17 a and 17 c of the water jackets 17 </ b> F and 17 </ b> R of the cylinder block 11 are communicated with each other via the inlet side communication passage 21. The inlet side communication path 21 is configured such that the cooling water flowing in from the cooling water inlet 21 a communicating with the block side flow path 112 is divided into two by the inlet side communication path 21 and flows out. . And the cooling water branched by the entrance side communication path 21 is each flowed in into the water jackets 17F and 17R.

  The cooling water outlets 17b and 17d of the water jackets 17F and 17R are in communication with each other via the outlet side communication passage 22. The outlet side communication path 22 is configured such that the cooling water that has flowed in from each of the water jackets 17F and 17R merges into one through the outlet side communication path 22 and flows out. And the cooling water merged by the exit side communication path 22 flows out into the outflow channel 114 from the cooling water outlet 22a.

  On the other hand, the cooling water inlets 18 a and 18 c of the water jackets 18 F and 18 R of the cylinder heads 14 F and 14 R are communicated with each other via the inlet side communication passage 23. The inlet side communication path 23 is configured such that the cooling water flowing in from the cooling water inlet 23 a communicating with the head side flow path 113 is divided into two by the inlet side communication path 23 and flows out. . And the cooling water branched by the entrance side communication path 23 is each flowed in into the water jackets 18F and 18R.

  The cooling water outlets 18b and 18d of the water jackets 18F and 18R of the cylinder heads 14F and 14R are communicated with each other via the outlet side communication passage 24. The outlet side communication passage 24 is configured such that the cooling water that has flowed in from each of the water jackets 18F and 18R merges into one through the outlet side communication passage 24 and flows out. And the cooling water merged by the exit side communication path 24 flows out into the outflow channel 115 from the cooling water outlet 24a. The outflow channels 114 and 115 are merged on the upstream side of the inlet 41 of the radiator 40, but bypass the radiator 40 and the channel 118 communicating with the inlet 41 side of the radiator 40 at the junction. The bypass channel 120 is branched.

  The inlet side communication paths 21 and 23 and the outlet side communication paths 22 and 24 are provided across the banks 12F and 12R before and after the engine 10. The inlet side communication passages 21 and 23 are provided on one side (the right side in FIG. 2) in the left-right direction of the engine 10, and are disposed in the vicinity of the water pump 30. The outlet side communication passages 22 and 24 are provided on the other side (left side in FIG. 2) of the engine 10 in the left-right direction. The inlet side communication passages 21 and 23 and the outlet side communication passages 22 and 24 may be formed by passages provided inside the engine 10 or may be formed by piping provided outside the engine 10. Good.

  Further, the water jacket 18F of the cylinder head 14F of the front bank 12F is communicated with the EGR cooler flow path 116 via a cooling water outlet 25 formed in the cylinder head 14F. The EGR cooler channel 116 is a channel that extends from the cooling water outlet 25 to the suction port side of the water pump 30. An EGR cooler 50 is disposed in the middle of the EGR cooler flow path 116.

  Further, the water jacket 17R of the cylinder block 11 of the rear bank 12R is communicated with the heater flow path 117 via the cooling water outlet 26 formed in the cylinder block 11 of the rear bank 12R. The heater channel 117 is a channel from the cooling water outlet 26 to the suction port side of the water pump 30. A heater valve 61 and a heater core 60 are disposed in the middle of the heater channel 117.

  The heater valve 61 is a flow rate control valve that controls the flow rate of the cooling water supplied to the heater core 60 by adjusting the opening degree. The opening degree of the heater valve 61 is controlled by an ECU (not shown). Specifically, when the air conditioning switch is operated by the occupant and a heater request (heating request) is generated in the passenger compartment, the heater valve 61 is switched to an open state. As a result, the cooling water is supplied to the heater core 60 and the passenger compartment is heated. The opening degree of the heater valve 61 is adjusted according to the required flow rate of the heater core 60 based on the heater request. On the other hand, when there is no heater request, the heater valve 61 is switched to a closed state, and cooling water is not supplied to the heater core 60.

  The cooling water circulation circuit 100 is provided with first and second thermostats 70 and 80 for switching the cooling water circulation path.

  The first thermostat 70 is provided between the inlet side communication path 21 of the cylinder block 11 and the discharge port of the water pump 30. Here, the first thermostat 70 is provided in the block-side flow path 112 that supplies cooling water to the water jackets 17F and 17R of the cylinder block 11.

  The first thermostat 70 is configured as a wax type thermostat that opens and closes according to the temperature of the cooling water. Specifically, the first thermostat 70 is configured such that a valve (valve element) is actuated by expansion and contraction of a thermo wax (for example, paraffin wax or the like) in a heat sensitive part. The first thermostat 70 is provided with a first port 71, a second port 72, and a third port 73.

  The first port 71 communicates with the upstream flow path 112 a on the upstream side of the first thermostat 70 in the block side flow path 112. The second port 72 is in communication with the downstream-side channel 112 b on the downstream side of the first thermostat 70 in the block-side channel 112. The third port 73 communicates with the bypass flow path 112c. The bypass channel 112c is provided with a restriction 90, and the channel cross-sectional area of the bypass channel 112c is smaller than the channel cross-sectional area of the downstream channel 112b. The downstream end of the bypass flow path 112c is connected to the downstream flow path 112b. The flow rate of the cooling water flowing through the bypass flow path 112c is limited by the throttle 90, and the flow rate is set to a minimum flow rate that can secure the required flow rate of the heater core 60. The flow rate is set so as not to adversely affect.

  In the first thermostat 70, the first port 71 and the second port 72, and the first port 71 and the third port 73 are communicated or blocked by the operation of the valve. In this case, when the first port 71 and the second port 72 are communicated, the first port 71 and the third port 73 are blocked, and conversely, the first port 71 and the third port 73 are communicated. Then, the first port 71 and the second port 72 are blocked.

  The first thermostat 70 supplies the cooling water from the water pump 30 to the water jackets 17F and 17R of the cylinder block 11 via the throttle 90 (the state shown in FIGS. 3 and 4), and passes through the throttle 90. It is switched to the state (state of FIG. 5) performed without doing.

  Specifically, when the temperature of the cooling water is cold at a relatively low temperature, specifically, when the temperature of the cooling water is equal to or lower than the first switching temperature Th1, the thermowax contracts and the first port 71 and the third port 73 are switched to a state where they communicate with each other (the states shown in FIGS. 3 and 4). In this state, the cooling water discharged by the water pump 30 flows from the upstream channel 112a into the bypass channel 112c. Thereby, the cooling water discharged by the water pump 30 is supplied to the water jackets 17F and 17R of the cylinder block 11 with the flow rate restricted by the throttle 90. Note that the first switching temperature Th1 is set to a temperature at which the warm-up of the engine 10 is completed.

  On the other hand, when the temperature of the cooling water rises and becomes higher than the first switching temperature Th1, the thermowax expands and switches to a state in which the first port 71 and the second port 72 communicate with each other (FIG. 5). State). In this state, the cooling water discharged by the water pump 30 flows from the upstream channel 112a into the downstream channel 112b. Thus, the cooling water discharged by the water pump 30 is supplied to the water jackets 17F and 17R of the cylinder block 11 without being restricted by the flow rate by the throttle 90.

  The second thermostat 80 is provided between the outlet 42 of the radiator 40 and the suction port of the water pump 30. Here, the second thermostat 80 is provided at a junction where the flow path 119 on the outlet 42 side of the radiator 40 and the bypass flow path 120 merge. The bypass flow path 120 is provided to circulate cooling water without passing through the radiator 40, and is arranged in parallel with the radiator 40. Specifically, the bypass flow path 120 is a flow path that extends from the junction of the outflow flow paths 114 and 115 to the second thermostat 80.

  The second thermostat 80 is configured as a wax type thermostat that opens and closes according to the temperature of the cooling water. Specifically, the second thermostat 80 is configured such that a valve (valve element) is actuated by expansion and contraction of a thermo wax (for example, paraffin wax or the like) in a heat sensitive part. The second thermostat 80 is provided with a first port 81, a second port 82, and a third port 83.

  The first port 81 communicates with the flow path 119. The second port 82 communicates with the bypass flow path 120. The third port 83 communicates with a flow path 121 that communicates with the suction port side of the water pump 30.

  In the second thermostat 80, the first port 81 and the third port 83, and the second port 82 and the third port 83 are communicated or blocked by the operation of the valve. In this case, when the first port 81 and the third port 83 communicate with each other, the second port 82 and the third port 83 are blocked, and conversely, the second port 82 and the third port 83 communicate with each other. Thus, the first port 81 and the third port 83 are blocked.

  The second thermostat 80 is in a state in which the cooling water is circulated in the bypass circuit 102 via the radiator 40 (state in FIG. 3), and in a state in which the cooling water is circulated in the radiator circuit 101 without passing through the radiator 40 (FIG. 4). , The state of FIG. 5).

  Specifically, when the temperature of the cooling water is low, specifically, when the temperature of the cooling water is equal to or lower than the second switching temperature Th2, the thermowax contracts and the second port 82 and the third The state is switched to the state in which the port 83 communicates (the state shown in FIG. 3). In this state, the cooling water is returned to the water pump 30 side via the bypass flow path 120. As described above, the cooling water is circulated in the bypass circuit 102 and the cooling water is not circulated through the radiator 40, so that warm-up of the engine 10 is promoted. The second switching temperature Th2 is set to a temperature lower than the first switching temperature Th1 (Th2 <Th1).

  On the other hand, when the temperature of the cooling water rises and becomes higher than the second switching temperature Th2, the thermowax expands and is switched to a state where the first port 81 and the third port 83 communicate with each other (FIG. 4, The state of FIG. In this state, the cooling water is returned to the water pump 30 side via the radiator 40. In this way, the cooling water is circulated by the radiator circuit 101 and the cooling water is circulated through the radiator 40, so that the heat recovered by the cooling water is released from the radiator 40 to the atmosphere.

  Next, the operation of the cooling device for the V-type engine provided with the cooling water circulation circuit 100 having the above-described configuration will be described with reference to FIGS. 3 to 5, the flow path through which the cooling water circulates is indicated by a thick solid line, and the flow path through which the cooling water does not circulate is indicated by a broken line. 3 to 5 show a state where there is a heater request and the heater valve 61 is open, but when there is no heater request, the heater valve 61 is switched to a closed state.

  In this embodiment, by switching the operating state of the first thermostat 70 and the second thermostat 80 in accordance with the temperature of the cooling water (cooling water temperature) Thw, the circulation path in which the cooling water circulation is performed is changed as follows. It has become so.

  First, as shown in FIG. 3, when the cooling water temperature Thw is equal to or lower than the second switching temperature Th2 (Thw ≦ Th2), the first thermostat 70 communicates with the first port 71 and the third port 73. The second thermostat 80 is switched to a state in which the second port 82 and the third port 83 communicate with each other. Thereby, the cooling water is circulated through the bypass circuit 102, the EGR cooler circuit 103, and the heater circuit 104.

  Specifically, in the bypass circuit 102, the cooling water is circulated in the order of the water jackets 17 </ b> F, 17 </ b> R, 18 </ b> F, 18 </ b> R of the engine 10 → the bypass flow path 120 → the second thermostat 80 → the water pump 30. In the EGR cooler circuit 103, the cooling water is circulated in the order of the water jacket 18 </ b> F of the cylinder head 14 </ b> F of the front side bank 12 </ b> F of the engine 10 → the EGR cooler 50 → the water pump 30. In the heater circuit 104, cooling water is circulated in the order of the water jacket 17 </ b> R of the cylinder block 11 of the rear bank 12 </ b> R of the engine 10 → the heater valve 61 → the heater core 60 → the water pump 30. When the heater request is completed, the circulation of the cooling water in the heater circuit 104 is stopped.

  In this state, since the circulation of the cooling water in the radiator circuit 101 is stopped, warm-up of the engine 10 is promoted. Further, since the flow rate of the cooling water circulating through the water jackets 17F and 17R of the cylinder block 11 is limited by the throttle 90, the cooling of the cylinder block 11 is suppressed and the warming up is not hindered. On the other hand, cooling water is circulated through the water jackets 18F and 18R of the cylinder heads 14F and 14R without limiting the flow rate.

  Next, as shown in FIG. 4, when the coolant temperature Thw is higher than the second switching temperature Th2 and is equal to or lower than the first switching temperature Th1 (Th2 <Thw ≦ Th1), the first thermostat 70. However, the first port 71 and the third port 73 are switched to the communication state, and the second thermostat 80 is switched to the communication state of the first port 81 and the third port 83. As a result, cooling water is circulated through the radiator circuit 101, the EGR cooler circuit 103, and the heater circuit 104.

  Specifically, in the radiator circuit 101, the cooling water is circulated in the order of the water jackets 17F, 17R, 18F, and 18R of the engine 10 → the radiator 40 → the second thermostat 80 → the water pump 30. The flow of cooling water in the EGR cooler circuit 103 and the heater circuit 104 is substantially the same as in the case of FIG. 3 described above.

  In this state, the cylinder heads 14F and 14R are cooled by the cooling water circulating in the radiator circuit 101. In this case, cooling water is circulated through the water jackets 18F and 18R of the cylinder heads 14F and 14R without limiting the flow rate. On the other hand, since the flow rate of the cooling water circulating through the water jackets 17F and 17R of the cylinder block 11 is limited by the throttle 90, excessive cooling of the cylinder block 11 is suppressed, and the warm-up is not hindered. Yes.

  Next, as shown in FIG. 5, when the coolant temperature Thw is higher than the first switching temperature Th1 (Thw> Th1), the first thermostat 70 is connected to the second port 72 and the third port 73. The state is switched to the communication state, and the second thermostat 80 is switched to the state where the first port 81 and the third port 83 are in communication. As a result, cooling water is circulated through the radiator circuit 101, the EGR cooler circuit 103, and the heater circuit 104. The flow of cooling water in the radiator circuit 101, the EGR cooler circuit 103, and the heater circuit 104 is substantially the same as in the case of FIG. 4 described above.

  In this state, the cylinder block 11 and the cylinder heads 14F and 14R are cooled by the cooling water circulating through the radiator circuit 101. In this case, cooling water is circulated through the water jackets 18F and 18R of the cylinder heads 14F and 14R without limiting the flow rate. Further, since the cooling water does not pass through the throttle 90 in the water jackets 17F and 17R of the cylinder block 11, the cooling water is circulated without being restricted in flow rate so that the cooling water having a necessary flow rate is reliably supplied. It has become.

  Here, since the cooling water is actively circulated in the water jackets 18F and 18R of the cylinder heads 14F and 14R even during the warming-up of the engine 10 where the cooling water temperature Thw is equal to or lower than the first switching temperature Th1, The cylinder heads 14 </ b> F and 14 </ b> R are at a lower temperature than the cylinder block 11. In addition, when the vehicle is traveling forward, the front bank 12F of the engine 10 is located in front of the traveling wind, so that it is easily cooled by the traveling wind. Therefore, the cylinder head 14F of the front side bank 12F of the engine 10 is likely to be in the lowest temperature state in the engine 10.

  In this embodiment, the EGR cooler 50 is disposed in the vicinity of the cylinder head 14F of the front side bank 12F of the engine 10, and the cooling water taken out from the water jacket 18F of the cylinder head 14F is supplied to the EGR cooler 50. . Thereby, the EGR cooler 50 can be operated efficiently, and the cooling performance of the EGR cooler 50 can be sufficiently exerted, and the cooling efficiency of the EGR gas by the EGR cooler 50 can be increased.

  On the other hand, the flow rate of the cooling water circulated through the water jackets 17F and 17R of the cylinder block 11 of the engine 10 is limited by the throttle 90 while the engine 10 is warmed up so that the cooling water temperature Thw becomes equal to or lower than the first switching temperature Th1. The cylinder block 11 is hotter than the cylinder heads 14F and 14R. In addition, when the vehicle is traveling forward, the rear bank 12R of the engine 10 is hard to receive the traveling wind and is likely to accumulate heat. Therefore, the cylinder block 11 of the rear bank 12R of the engine 10 is likely to be the hottest state in the engine 10.

  In this embodiment, the heater core 60 is disposed in the vicinity of the cylinder block 11 of the rear side bank 12R of the engine 10, and the cooling water taken out from the water jacket 17R of the cylinder block 11 is supplied to the heater core 60. . Thereby, the heater core 60 can be operated efficiently, and the heating performance of the heater core 60 can be sufficiently exhibited, and the heating efficiency of the vehicle interior by the heater core 60 can be enhanced.

  Therefore, according to this embodiment, the EGR cooler 50 installed in the cooling water circulation circuit 100 using the fact that the temperature difference generated in the engine 10 mounted horizontally in the front portion of the vehicle 1 becomes large, By supplying cooling water to a heat exchange device such as the heater core 60, the heat exchange device can be operated efficiently. Moreover, since the EGR cooler 50 is disposed on the front side of the front bank 12F of the engine 10 and the heater core 60 is disposed on the rear side of the rear bank 12R, cooling water from the engine 10 to the EGR cooler 50 is disposed. The length of the piping and the length of the cooling water piping from the engine 10 to the heater core 60 can be shortened.

-Other embodiments-
The present invention is not limited only to the above-described embodiments, and all modifications and applications within the scope of the claims and within the scope equivalent to the scope are possible.

  The above-described cooling water circulation circuit 100 is an example, and is provided independently of the water jackets 17F and 17R of the cylinder block 11 and the water jackets 18F and 18R of the cylinder heads 14F and 14R. If the flow rate of the cooling water circulated through the water jackets 17F and 17R of the cylinder block 11 is limited, various changes can be made. For example, when the engine 10 is warmed up, the cooling water is not circulated through the water jackets 17F and 17R of the cylinder block 11, and the cooling water is circulated only through the water jackets 18F and 18R of the cylinder heads 14F and 14R. Ten warm-ups may be promoted.

  Further, the EGR cooler 50 and the heater core 60 mentioned as the heat exchange device are an example, and by performing heat exchange with the cooling water flowing through the cooling water circulation circuit 100, the cooling target or the heating target is cooled. As long as heating is performed, various types of heat exchange devices can be provided in the cooling water circulation circuit 100. In addition, as an EGR cooler 50, as a heat exchange device, the heat exchange device of the type which mainly radiates heat to cooling water (in other words, the heat exchange device of the type which cools the object to be cooled with cooling water), and the heater core 60 Thus, there is a type of heat exchange device that mainly absorbs heat from cooling water (in other words, a type of heat exchange device that heats a heating target with cooling water).

  The heat exchange device of the type that radiates heat to the cooling water is preferably disposed in front of the front side bank 12F of the engine 10, and the water of the cylinder head 14F of the front side bank 12F is opposed to the heat exchange device. It is desirable to supply the cooling water taken out from the jacket 18F. On the other hand, it is desirable to dispose the heat exchange device of the type that absorbs heat from the cooling water on the rear side of the rear bank 12R of the engine 10, and with respect to this heat exchange device, the water in the cylinder block 11 of the rear bank 12R. It is desirable to supply the cooling water taken out from the jacket 17R.

  As a heat exchange device other than the EGR cooler 50 and the heater core 60, for example, as shown in FIG. 6, an oil cooler 91 for cooling engine oil that lubricates and cools each part of the engine 10, intake air compressed by a turbocharger There are an intercooler 92 for cooling, a throttle body 93 provided in the intake passage of the engine 10 and incorporating a throttle valve. Among these, the oil cooler 91 and the intercooler 92 are heat exchange devices that radiate heat to the cooling water, and the cooling water taken out from the water jacket 18F of the cylinder head 14F of the front side bank 12F is the oil cooler 91 and the intercooler. 92 is supplied. In the example of FIG. 6, the oil cooler 91 and the intercooler 92 are each arranged in parallel with the EGR cooler 50. And the cooling water which flowed out from the oil cooler 91, and the cooling water which flowed out from the intercooler 92 are distribute | circulated to the flow path 119 between the exit 42 of the radiator 40, and the 2nd thermostat 80, respectively. .

  On the other hand, the throttle body 93 is a type of heat exchange device that absorbs heat from the cooling water, and the cooling water taken out from the water jacket 17R of the cylinder block 11 of the rear bank 12R is supplied to the throttle body 93. Yes. In the example of FIG. 6, the throttle body 93 is disposed in parallel with the heater core 60 and the heater valve 61. The cooling water that has flowed out of the throttle body 93 is returned to the suction port side of the water pump 30.

  The present invention relates to a cooling device for a V-type engine mounted horizontally in a front portion of a vehicle such as an automobile, wherein a cooling water passage on a cylinder block side and a cooling water passage on a cylinder head side are independent of each other. The present invention can be used for a two-system cooling system cooling device provided.

1 Vehicle 10 V-type Engine 11 Cylinder Block 12F Front Bank (Front Bank)
12R Rear bank (rear bank)
14F, 14R Cylinder head 17F, 17R Water jacket (cooling water flow path)
18F, 18R Water jacket (cooling water flow path)
30 Water pump 40 Radiator 50 EGR cooler (Heat exchange device)
60 Heater core (heat exchange device)
100 Cooling water circulation circuit

Claims (6)

A V-type engine mounted horizontally in the front of the vehicle, a water pump, a radiator, and a cooling water circulation circuit for circulating cooling water to these devices,
A cooling device for a V-type engine in which a cooling water passage on a cylinder block side of a V-type engine and a cooling water passage on a cylinder head side are provided independently of each other,
The cooling water circulation circuit is provided with a type of heat exchange device that radiates heat to the cooling water and a type of heat exchange device that absorbs heat from the cooling water,
The heat exchange device of the type that radiates heat to the cooling water is supplied with cooling water from the cooling water flow path on the cylinder head side of the front bank of the pair of front and rear banks of the V-type engine,
In the heat exchange device of the type that absorbs heat from the cooling water, the cooling water is supplied from a cooling water flow path on the cylinder block side of the rear bank of the pair of front and rear banks of the V-type engine. Engine cooling system. The cooling device for a V-type engine according to claim 1,
The type of heat exchange device that radiates heat to the cooling water is disposed on the front side of the front bank, and the type of heat exchange device that absorbs heat from the cooling water is disposed on the rear side of the rear bank. V-type engine cooling device. The cooling device for a V-type engine according to claim 1 or 2,
A cooling apparatus for a V-type engine, wherein a flow rate of cooling water circulated through the cooling water flow path on the cylinder block side is limited during warm-up of the V-type engine. The V-type engine cooling device according to any one of claims 1 to 3,
A cooling apparatus for a V-type engine, characterized in that cooling water is always circulated through the cooling water passage on the cylinder head side during operation of the V-type engine. The cooling device for a V-type engine according to any one of claims 1 to 4,
The heat exchange device of the type that radiates heat to the cooling water is an EGR cooler provided in an EGR passage that recirculates part of the exhaust gas flowing through the exhaust passage of the V-type engine to the intake passage. Engine cooling system. The cooling device for a V-type engine according to any one of claims 1 to 5,
The V-type engine cooling apparatus, wherein the heat exchange device that absorbs heat from the cooling water is a heater core for heating the vehicle interior.

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