JP2016000971A - Internal combustion engine system with supercharger - Google Patents

Abstract

PROBLEM TO BE SOLVED: To heat cooling water used in an intercooler as early as possible after implementing an engine warm-up operation.SOLUTION: EGR gas is introduced into an intake passage 12 upstream of a compressor 24a. An internal combustion engine system with a supercharger includes a first main cooling water channel 70 circulating first cooling water among an engine body 10a, a first heater core 62, and a first radiator 64. The internal combustion engine system with the supercharger includes a second main cooling water channel 90 circulating second main cooling water among an intercooler 28, an EGR cooler 38, an EGR valve body 40a, the turbine 24b, an exhaust heat recovery unit 94, a second heater core 82, and a second radiator 84. An engine warm-up operation after starting an engine in a cold state is executed in a state in which a second water pump 86 is driven using a second bypass channel form in which the second cooling water does not pass the second radiator 84 and the second cooling water recovers heat of the exhaust heat recovery unit 94.

Description

  The present invention relates to an internal combustion engine system with a supercharger, and more particularly to an internal combustion engine system with a supercharger that can introduce EGR gas into an intake passage upstream of a compressor that supercharges intake gas.

  Conventionally, for example, Patent Document 1 discloses a cooling device for an internal combustion engine including an exhaust heat recovery device. More specifically, this conventional cooling device includes an exhaust heat recovery device in the middle of a cooling water circuit for cooling the engine body. When the cooling water is at a low temperature (when the engine is cold), the exhaust heat recovery is executed without limiting the cooling water flow rate. On the other hand, when the cooling water temperature rises, the cooling water flow rate is limited and the exhaust heat recovery is performed. Non-executable.

JP 2008-231942 A

  An internal combustion engine including a compressor that supercharges intake gas, an intercooler that cools intake gas supercharged by the compressor, and an EGR device that introduces EGR gas into an intake passage upstream of the compressor includes the following: There is a problem like this. That is, if the introduction of EGR gas can be started as soon as possible during warm-up of the internal combustion engine, it can be said that a greater fuel efficiency effect due to the introduction of EGR gas can be obtained. However, in order to achieve early introduction of EGR gas during warm-up, it is necessary to take measures to suppress the generation of condensed water accompanying the introduction of EGR gas. This is because when condensed water is generated, corrosion of the water hammer and the piping constituting the intake passage may be caused, and further, the piping or various valves in the piping may be frozen.

  On the other hand, a water-cooled intercooler that cools intake gas that passes through the intercooler by circulation of cooling water is known. In particular, in order to improve the cooling performance of the mixed gas of intake air and EGR gas, a configuration is known in which a cooling water circuit independent of a cooling water circuit for cooling the engine body is used for the intercooler. However, as a contradiction to adopting such a configuration for the internal combustion engine, there is a problem in that if the cooling water flowing through the intercooler cannot be warmed early at the time of cold start, condensate water increases. .

  The present invention has been made to solve the above-described problems, and is provided with an internal combustion engine system with a supercharger capable of quickly raising the temperature of cooling water used for an intercooler after the engine warm-up operation is performed. The purpose is to provide.

A first invention is an internal combustion engine system with a supercharger,
A first radiator that cools a first coolant that cools an engine body that is a body of an internal combustion engine;
A first main cooling water flow path for circulating the first cooling water between the engine body and the first radiator;
A compressor that is disposed in the intake passage and supercharges gas flowing through the intake passage;
An EGR device that has an EGR passage that connects the intake passage and the exhaust passage upstream of the compressor, and that supplies part of the exhaust gas flowing through the exhaust passage to the intake passage;
An intercooler that is disposed in the intake passage downstream of the compressor and exchanges heat between the gas compressed by the compressor and the second cooling water that cools the gas;
A heat source device serving as a heat source for the second cooling water;
A second radiator for cooling the second cooling water;
A second main cooling water flow path for circulating the second cooling water between the intercooler, the heat source device, and the second radiator;
A first water pump installed in the first main cooling water flow path and pumping the first cooling water;
A second water pump that is installed in the second main cooling water flow path and pumps the second cooling water;
A first bypass flow path that branches from the first main cooling water flow path on the upstream side of the first radiator, and merges with the first main cooling water flow path on the downstream side of the first radiator;
A second bypass flow path that branches from the second main cooling water flow path upstream from the second radiator and merges with the second main cooling water flow path downstream from the second radiator;
A first non-bypass flow path configuration in which the first cooling water passes through the first radiator, and the first cooling water passes through the first bypass flow path so that the first cooling water passes through the first radiator. A first switching valve that switches a flow path form of the first cooling water between a first bypass flow path form that does not pass;
A second non-bypass flow path configuration in which the second cooling water passes through the second radiator; and the second cooling water passes through the second bypass flow path so that the second cooling water passes through the second radiator. A second switching valve for switching the flow path configuration of the second cooling water with a second bypass flow channel configuration that does not pass through;
With
When the compressor is a turbocharger compressor, the heat source device includes at least one of a turbine of the turbocharger and an exhaust heat recovery unit that performs heat exchange between the exhaust gas and the second cooling water. Including one or, if the compressor is a compressor of a turbocharger of a type other than the turbocharger, including the exhaust heat recovery device,
The flow path configuration of the second cooling water is selected to use the second non-bypass flow path configuration, the second water pump is driven, and the heat of the heat source device is recovered by the second cooling water. The engine warm-up operation after the cold start of the internal combustion engine is performed in a state where it is permitted to perform the operation.

The second invention is the first invention, wherein
A first and a second heater core functioning as a heat source for a vehicle interior heater of a vehicle equipped with an internal combustion engine;
The first heater core is installed in the middle of the first main cooling water flow path,
The second heater core is installed in the middle of the second main cooling water flow path.

The third invention is the second invention, wherein
When the engine warm-up operation is performed, the first water pump is driven in a state where the flow path configuration of the first cooling water is selected so as to use the first bypass flow path configuration,
When the required degree of heating using the vehicle interior heater is high, the target temperature of the second cooling water during the engine warm-up operation is a temperature at which the temperature of the first cooling water can meet the heating request. It is characterized by the fact that the required degree of heating is increased as compared with the case where the required degree of heating is low.

Moreover, 4th invention is set in any one of 1st-3rd invention,
The EGR device includes an EGR cooler that cools EGR gas flowing through the EGR passage,
The EGR cooler is installed in the middle of the second main cooling water flow path.

Moreover, 5th invention is based on any one of 1st-4th invention,
The EGR device includes an EGR valve that adjusts an amount of EGR gas flowing through the EGR passage,
The EGR valve body of the EGR valve is installed in the middle of the second main cooling water flow path.

Moreover, 6th invention is set in any one of 1st-5th invention,
The EGR device includes an EGR cooler that cools EGR gas flowing through the EGR passage, and an EGR valve that adjusts the amount of EGR gas flowing through the EGR passage,
The EGR cooler and the EGR valve body of the EGR valve are installed in the middle of the second main cooling water flow path,
The target temperature of the second cooling water during the engine warm-up operation is a minimum temperature at which condensed water is not generated in the intercooler, the EGR cooler, and the EGR valve body, or a predetermined margin is given to the minimum temperature. Temperature.

Moreover, 7th invention is set in any one of 1st-6th invention,
The first main cooling water channel and the second main cooling water channel are configured such that the capacity of the second cooling water is smaller than the capacity of the first cooling water.

  According to the first invention, during the engine warm-up operation, at least one of the turbine and the exhaust heat recovery device is used as a heat source device to raise the temperature of the second cooling water. Such a heat source device becomes hot immediately after the engine is started. For this reason, by using such a heat source device, the second cooling water is used as compared with the case of using the heat transfer from the cooling water for the engine body to the cooling water for the intercooler as in the conventional internal combustion engine system. The temperature can be increased directly. Thereby, after implementation of engine warm-up operation, the temperature of the 2nd cooling water utilized for an intercooler can be raised at an early stage. Further, since the first main cooling water flow path for the engine main body and the second main cooling water flow path for the intercooler are independent, the engine main body, the intercooler and the heat source device are placed in one cooling water circuit. Compared with the case where it prepares for, the flow rate of the cooling water circulating through the circuit while passing through the heat source device is reduced. For this reason, it can be said that the temperature of the second cooling water used for the intercooler can be raised quickly after the engine warm-up operation is performed. These things lead to an early temperature rise of the second cooling water to a temperature at which condensed water is not generated in the intercooler. As a result, the timing at which the introduction of EGR gas can be started without concern about the generation of condensed water. It leads to speeding up.

  According to the second invention, not only the intercooler but also the temperature of the second heater core using the second cooling water can be raised early after the engine warm-up operation. And by providing the 2nd heater core which can raise such an early temperature, compared with the case where only 1st cooling water is used, after a cold start, a vehicle interior heater is early (namely, 1st cooling water). Can be used even when the temperature is not warm enough.

  According to the third aspect of the invention, the performance of the vehicle interior heater can be improved when the engine is warmed up according to the degree of heating demand from the vehicle user.

  According to the fourth aspect of the invention, the second cooling water whose temperature rises early after the engine warm-up operation can be introduced also to the EGR cooler. This leads to an early rise of the EGR cooler temperature to a temperature at which condensed water is not generated in the EGR cooler.

  According to the fifth aspect of the invention, the second cooling water whose temperature rises early after the engine warm-up operation can be introduced also to the EGR valve body. This leads to an early rise of the EGR valve body temperature to a temperature at which condensed water is not generated in the EGR valve body.

  According to the sixth aspect of the invention, during the warm-up operation of the engine, the second cooling water is brought to a temperature at which condensate does not occur in the intercooler, EGR cooler, and EGR valve body while minimizing the influence on the intake charging efficiency. Temperature can be controlled.

  According to the seventh invention, it is possible to more effectively realize an early rise in the temperature of the second cooling water using the heat source device.

1 is a diagram schematically illustrating a configuration of a supercharger-equipped internal combustion engine system according to Embodiment 1 of the present invention. FIG. It is a time chart for demonstrating the effect acquired by the engine warming-up operation | movement of the internal combustion engine system in Embodiment 1 of this invention. It is a time chart for demonstrating the outline | summary of the characteristic cooling water temperature control in Embodiment 2 of this invention. It is a flowchart of the routine performed in Embodiment 2 of this invention.

Embodiment 1 FIG.
[Configuration of internal combustion engine system with turbocharger]
FIG. 1 is a diagram schematically showing a configuration of an internal combustion engine system with a supercharger according to Embodiment 1 of the present invention.

(Overall configuration of internal combustion engine system)
The internal combustion engine system shown in FIG. 1 includes an internal combustion engine (a gasoline engine as an example) 10. An intake passage 12 and an exhaust passage 14 communicate with each cylinder of the internal combustion engine 10. An air cleaner 16 is attached in the vicinity of the inlet of the intake passage 12. The air cleaner 16 includes an air flow meter 18 that outputs a signal corresponding to the flow rate of air (fresh air) sucked into the intake passage 12, an intake air temperature sensor 20 for detecting the temperature of intake air (≈outside air temperature), and An intake humidity sensor 22 for detecting the humidity of the intake air (≈outside air humidity) is provided.

  A compressor 24 a of the turbocharger 24 is installed downstream of the air cleaner 16. The compressor 24a is integrally connected to a turbine 24b disposed in the exhaust passage 14 via a connecting shaft. An electronically controlled throttle valve 26 is provided downstream of the compressor 24a. A water-cooled intercooler 28 for cooling the air compressed by the compressor 24 a is provided downstream of the throttle valve 26. Further, an exhaust purification catalyst (here, a three-way catalyst) 30 is disposed in the exhaust passage 14 on the downstream side of the turbine 24b. A muffler 32 is disposed in the vicinity of the exhaust port of the exhaust passage 14.

  Further, the internal combustion engine 10 shown in FIG. 1 includes a low-pressure loop (LPL) type EGR device 34. The EGR device 34 includes an EGR passage 36 that connects the exhaust passage 14 downstream of the exhaust purification catalyst 30 and the intake passage 12 upstream of the compressor 24a. The EGR passage 36 is provided with an EGR cooler 38 and an EGR valve 40 in order from the upstream side of the EGR gas flow when introduced into the intake passage 12. The EGR cooler 38 is water-cooled, and is provided for cooling the EGR gas flowing through the EGR passage 36. The EGR valve 40 controls the amount of EGR gas that is recirculated to the intake passage 12 through the EGR passage 36. Provided to adjust.

  Further, the system shown in FIG. 1 includes an ECU (Electronic Control Unit) 50. The ECU 50 includes an arithmetic processing unit (CPU), a storage circuit including a ROM and a RAM, an input / output port, and the like. In addition to the air flow meter 18, the intake air temperature sensor 20 and the intake air humidity sensor 22 described above, an internal combustion engine 10 such as a crank angle sensor 52 for detecting the engine speed and water temperature sensors 74 and 96 is provided at the input port of the ECU 50. Various sensors for detecting the driving state are electrically connected. Further, in addition to the throttle valve 26 and the EGR valve 40 described above, an output port of the ECU 50 includes a fuel injection valve 54 for supplying fuel to the internal combustion engine 10, an ignition device 56 for igniting an air-fuel mixture in the cylinder, Various actuators for controlling the operation of the internal combustion engine 10, such as the second water pump 86, the second switching valve 88, and the third switching valve 98, are electrically connected. Further, an air conditioning switch 58 of a vehicle on which the internal combustion engine 10 is mounted is electrically connected to the input port of the ECU 50. Thereby, ECU50 can acquire the information (for example, preset temperature in a vehicle interior) which shows the request | requirement degree of the heating using a vehicle interior heater (illustration omitted). The ECU 50 controls the operation of the internal combustion engine 10 by operating various actuators according to the outputs of the various sensors described above and a predetermined program.

(Configuration of internal combustion engine cooling system)
The cooling system of the internal combustion engine 10 includes a first cooling water circuit 60 and a second cooling water circuit 80 as two water-cooling cooling circuits that circulate cooling water. The first cooling water circuit 60 is a circuit for mainly cooling a main body (hereinafter referred to as “engine main body”) 10 a of the internal combustion engine 10 using the first cooling water. The second cooling water circuit 80 is provided separately from the first cooling water circuit 60 and is a circuit for cooling the gas passing through the intercooler 28 using the second cooling water. The first cooling water circuit 60 is responsible for cooling the engine body 10 a having a higher heat load than the intercooler 28. For this reason, the temperature of the first cooling water is basically higher than the temperature of the second cooling water. Conversely, it can be said that the second cooling water circuit 80 is a circuit in which the second cooling water having a temperature lower than that of the first cooling water circulates. In addition, the arrow in FIG. 1 has shown the flow direction of the cooling water which flows through the 1st and 2nd cooling water circuits 60 and 80. FIG.

  First, a specific configuration of the first cooling water circuit 60 will be described. The first cooling water circuit 60 includes the engine body 10 a, the first heater core 62, the first radiator 64, the first water pump 66, the first switching valve 68, the first main cooling water flow path 70, and the first bypass flow path 72. Has been. Further, a first water temperature sensor 74 for detecting the temperature of the first cooling water is attached to the first main cooling water flow path 70.

  The first main cooling water channel 70 is a channel for circulating the first cooling water among the engine body 10 a, the first heater core 62, and the first radiator 64. Inside the engine main body 10a, a cooling water flow path that functions as a part of the first main cooling water flow path 70 is stretched so as to cool each part in the engine main body 10a (cylinder head, cylinder block, etc.). The first heater core 62 functions as a heat source for the vehicle interior heater, and is a heat exchanger that exchanges heat between the air in the vehicle interior and the first cooling water. The first radiator 64 cools the first cooling water. The 1st water pump 66 is installed in the 1st main cooling water flow path 70, pumps the 1st cooling water, and is driven by the torque output from a crankshaft (illustration omitted) as an example.

  The first bypass flow path 72 is a flow path that branches from the first main cooling water flow path 70 on the upstream side of the first radiator 64 and merges with the first main cooling water flow path 70 on the downstream side of the first radiator 64. is there. The first switching valve 68 includes a first non-bypass flow path configuration in which the first cooling water passes through the first radiator 64, and the first cooling water passes through the first bypass flow path 72 so that the first cooling water is The flow path form of the first cooling water is switched between the form of the first bypass flow path that does not pass through the 1 radiator 64. As the first switching valve 68, for example, a thermostat is used. The first switching valve 68 opens when the temperature of the first cooling water reaches a predetermined temperature (for example, 80 ° C.), and switches the flow path configuration from the first non-bypass flow channel configuration to the first bypass flow channel configuration. The first water pump 66 is provided at a position where the first cooling water is circulated when using either flow path configuration. As an example of the position, the position shown in FIG. The junction part of the 1st bypass flow path 72 to the 1 main cooling water flow path 70 corresponds.

  When the first switching valve 68 is closed because the temperature of the first coolant in the first coolant circuit 60 is lower than the predetermined temperature (that is, when the engine is warming up), the first The cooling water circulates in the first cooling water circuit 60 without passing through the first radiator 64. On the other hand, when the first switching valve 68 is opened because the temperature of the first cooling water has reached the predetermined temperature (that is, after the warm-up of the internal combustion engine 10 is completed), the first radiator 64 is also in the first state. 1 Cooling water circulates. As a result, the first cooling water is cooled by the first radiator 64.

  Next, a specific configuration of the second cooling water circuit 80 will be described. The second cooling water circuit 80 includes an intercooler 28, a turbine housing 24b1 of the turbine 24b, an EGR cooler 38, an EGR valve body 40a of the EGR valve 40, a second heater core 82, a second radiator 84, a second water pump 86, a second The switching valve 88, the second main cooling water channel 90, the second bypass channel 92, and the exhaust heat recovery device 94 are configured. A second water temperature sensor 96 for detecting the temperature of the second cooling water is attached to the second main cooling water channel 90.

  The second main coolant flow path 90 circulates the second coolant between the intercooler 28, the turbine housing 24 b 1, the EGR cooler 38, the EGR valve body 40 a, the second heater core 82, and the second radiator 84. It is a channel for making it happen. The intercooler 28 of this embodiment is a water-cooled type, and heat-exchanges the gas (fresh air or a mixed gas of fresh air and EGR gas) compressed by the compressor 24a and the second cooling water. A cooling water flow path that functions as a part of the second main cooling water flow path 90 is formed in each of the turbine housing 24b1, the EGR cooler 38, and the EGR valve body 40a. Similarly to the first heater core 62, the second heater core 82 also functions as a heat source for the vehicle interior heater, and exchanges heat between the air in the vehicle interior and the second cooling water. The second radiator 84 cools the second cooling water. The 2nd water pump 86 is installed in the 2nd main cooling water flow path 90, and pumps the 2nd cooling water, and shall be an electric type here as an example. In addition, the arrangement of the first heater core 62 and the second heater core 82 in the warm air passage for exchanging heat between the air in the passenger compartment and the heater cores 62 and 82 may be in series with respect to the air flow direction. Or it may be parallel. The number of the first and second heater cores 62 and 82 may be plural.

  The second bypass flow path 92 is a flow path that branches from the second main cooling water flow path 90 on the upstream side of the second radiator 84 and merges with the second main cooling water flow path 90 on the downstream side of the second radiator 84. is there. The second switching valve 88 has a second non-bypass flow path configuration in which the second cooling water passes through the second radiator 84, and the second cooling water passes through the second bypass flow path 92 so that the second cooling water is The flow path configuration of the second cooling water is switched between the second bypass flow channel configuration that does not pass through the two radiators 84. The second switching valve 88 starts to open when the temperature of the second cooling water reaches a predetermined target temperature β, whereby the second switching valve 88 is replaced with or in addition to the second non-bypass flow path configuration. Use of the bypass flow path configuration is started. For example, an electronic thermostat is used as the second switching valve 88 capable of controlling the flow path configuration. By using the electronic thermostat, the second non-bypass flow path configuration (that is, passing through the second radiator 84) is achieved not only by switching the flow path configuration described above but also by adjusting the opening degree based on a command from the ECU 50. It is also possible to control the ratio between the flow rate of the second cooling water and the flow rate of the second cooling water that takes the form of the second bypass flow path (that is, does not pass through the second radiator 84). For this reason, the temperature of the second cooling water can be adjusted by adjusting the opening degree of the second switching valve 88. The second water pump 86 is provided at a position where the second cooling water is circulated when using either flow path configuration. As an example of the position, the second water pump 86 is located at the position shown in FIG. The junction part of the 2nd bypass flow path 92 to the 2 main cooling water flow paths 90 corresponds.

  The exhaust heat recovery device 94 is disposed in the exhaust passage 14 (in the example shown in FIG. 1, the exhaust passage 14 on the downstream side of the junction with the EGR passage 36). The exhaust heat recovery device 94 is a device that exchanges heat between the exhaust gas flowing through the exhaust passage 14 and the second cooling water. The exhaust heat recovery device 94 is configured to be able to select a control state in which heat is exchanged between the exhaust gas and the second cooling water and a control state in which heat exchange between the exhaust gas and the second cooling water is not performed. Since a specific method for realizing such a configuration is known, an example of the specific method will be briefly described here. That is, the exhaust heat recovery device 94 of this embodiment includes a bypass exhaust passage (not shown) for bypassing a part of the exhaust gas in the exhaust passage 14 near the exhaust heat recovery device 94. The exhaust heat recovery device 94 includes a third switching valve 98 capable of switching between a state where no exhaust gas is introduced into the bypass exhaust passage and a state where a part of the exhaust gas is introduced into the bypass exhaust passage. Yes. A part of the second main cooling water channel 90 is inserted inside the bypass exhaust passage so that the exhaust gas and the second cooling water can exchange heat.

  The case where the second switching valve 88 is closed because the temperature of the second cooling water in the second cooling water circuit 80 is lower than the target temperature β (the cold start initial stage (engine warm-up initial stage) corresponds to this case. ), The second cooling water circulates in the second cooling water circuit 80 without passing through the second radiator 84. On the other hand, when the second switching valve 88 is opened due to the temperature of the second cooling water reaching the target temperature β, the second cooling water is also circulated through the second radiator 84. As a result, the second cooling water is cooled by the second radiator 84. The order in which the second cooling water is introduced into each device on the second main cooling water channel 90 is not particularly limited. However, in terms of supplying as much heat as possible to the second heater core 82 in order to ensure good heating performance, the second heater core 82 is closest to the entrance of the second radiator 84 among the devices. It is preferably placed in position. Thereby, the second cooling water in a state of receiving heat as much as possible by other equipment such as the turbine housing 24b1 can be introduced into the second heater core 82.

(Cooling water capacity setting)
The first main cooling water channel 70 and the second main cooling water channel 90 are configured such that the capacity of the second cooling water is smaller than the capacity of the first cooling water. According to such a configuration, the intercooler 28 (moreover, the EGR cooler 38 and the EGR valve body 40a) is circulated during the engine warm-up operation, as compared with the case where the cooling system of each component described above is completed with one system. Early rise in cooling water can be realized more effectively.

(Main source of condensed water)
As with the internal combustion engine 10, a compressor that supercharges intake gas, a water-cooled intercooler that cools the intake gas supercharged by the compressor, and EGR gas is introduced into the intake passage upstream of the compressor. In an internal combustion engine equipped with an EGR device, condensed water is generated when the mixed gas of fresh air and EGR gas is cooled below its dew point when the mixed gas is cooled by an intercooler. Condensed water is also generated when the EGR gas is cooled below its dew point temperature by touching the EGR valve body when the EGR gas passes through the EGR valve. Further, when the internal combustion engine 10 is equipped with an EGR cooler, condensed water is also generated when the EGR gas passing through the EGR cooler is cooled below its dew point temperature.

[Operations and effects during engine warm-up operation of internal combustion engine system of Embodiment 1]
In the system of the internal combustion engine 10 having the above-described configuration, the following operation is performed during the engine warm-up operation after the cold start. That is, according to the 2nd switching valve 88 using an electronic thermostat, a 2nd non-bypass flow path form is obtained at the time of the start of engine warm-up operation. And the 2nd water pump 86 is driven in the state where the 2nd non-bypass channel form is used in this way. Regarding the first cooling water, according to the first switching valve 68 using a thermostat, the point that the first non-bypass flow path configuration is obtained at the start of the engine warm-up operation is that the second cooling water circuit 80 and It is the same. However, since the first water pump 66 exemplified in the present embodiment is a crankshaft drive type, the first coolant is circulated during engine warm-up operation without special control. The engine warm-up operation is an operation until the engine cooling water temperature (first cooling water temperature) is stabilized at a predetermined temperature after the cold start. In addition to the mode performed in the state, a mode performed in a state where the internal combustion engine 10 generates a driving force for traveling the vehicle is also included.

  Further, at the start of the engine warm-up operation, the third switching valve 98 is controlled so that the exhaust heat recovery device 94 is in a state where heat exchange between the exhaust gas and the second cooling water is performed. That is, the engine warm-up operation is started in a “state in which the heat of the exhaust heat recovery device 94 that is a heat source device is allowed to be recovered by the second cooling water”. Further, the system of the internal combustion engine 10 includes not only the exhaust heat recovery device 94 but also a turbine 24b as an equivalent to “heat source device”. However, in the case of the turbine 24b, heat is generated when the turbine 24b starts rotating with the start of operation of the internal combustion engine 10, and this heat is transmitted to the turbine housing 24b1. Then, heat exchange is performed between the turbine housing 24b1 and the second cooling water. As described above, in the case of the turbine 24b, “the heat of the turbine 24b as the heat source device is allowed to be recovered by the second cooling water at the start of the engine warm-up operation without requiring any special control. It can be said that the state has been "made."

  Furthermore, in the present embodiment, the target temperature β (the opening temperature of the second switching valve 88) of the second cooling water during the engine warm-up operation is the condensed water in the intercooler 28, the EGR cooler 38, and the EGR valve body 40a. It is set to be the lowest temperature that does not generate. More specifically, as described above, when the gas passing through each part of the intercooler 28, the EGR cooler 38, and the EGR valve body 40a is cooled below the dew point temperature, condensed water is generated. In other words, the temperature of each part of the intercooler 28, the EGR cooler 38, and the EGR valve body 40a is a gas that passes through each part (for the intercooler 28, it is a mixed gas of fresh air and EGR gas, and the EGR cooler 38 and EGR Concerning the valve body 40a, it can be said that condensed water is not generated if it is higher than the maximum dew point temperature of EGR gas (exhaust gas) flowing through the EGR passage 36. Therefore, the minimum temperature corresponds to a value slightly higher than the maximum value. Further, the target temperature β may be a temperature obtained by giving a predetermined margin (for example, a margin necessary for control) to the minimum temperature.

  The target temperature β set as described above varies depending on the outside air conditions (outside air temperature and outside air humidity conditions) and the engine operating conditions (engine speed, engine load, etc.). The ECU 50 stores a target temperature β determined in advance as a value corresponding to the outside air condition and the engine operating condition.

  Note that after the temperature of the second cooling water reaches the target temperature β during the engine warm-up operation, the temperature of the second cooling water is controlled so as to maintain the target temperature β. Such a water temperature control can be performed, for example, by adjusting the opening degree of the second switching valve 88, or by changing the discharge flow rate of the electric second water pump 86. Further, in the case of this system including the exhaust heat recovery device 94 as a heat source device, opening / closing control of the third switching valve 98 (opening control if opening adjustment is possible) for adjusting the temperature of the second cooling water. Thus, it is possible to use a method of adjusting the heat quantity of the exhaust gas recovered by the second cooling water.

  FIG. 2 is a time chart for explaining an effect obtained by the engine warm-up operation of the internal combustion engine system in the first embodiment of the present invention. FIG. 2A shows the transition of the first and second cooling water temperatures during the engine warm-up operation in the conventional internal combustion engine system used for comparison with the system of the internal combustion engine 10 of the first embodiment. FIG. 2B is a diagram for the system of the internal combustion engine 10 of the present embodiment. The conventional internal combustion engine system mentioned here has a cooling water circuit for the engine main body and a cooling water circuit for the intercooler in separate systems, but the heat source device is used for the intercooler as in this system. The cooling water circuit is not provided, and the temperature of the cooling water for the intercooler is raised by using heat transfer from the cooling water circuit for the engine body to the cooling water circuit for the intercooler.

  According to the system of the internal combustion engine 10 of the present embodiment, the turbine 24b and the exhaust heat recovery device 94 are used to raise the temperature of the second cooling water. These heat source devices become hot immediately after the engine is started. For this reason, by using these heat source devices, the second cooling water is directly used compared to the case of using the heat transfer from the cooling water for the engine body to the cooling water for the intercooler as in the conventional internal combustion engine system. The temperature can be increased. Further, since the first main cooling water flow path 70 for the engine main body 10a and the second main cooling water flow path 90 for the intercooler 28 are independent, the engine main body 10a, the intercooler 28, and the heat source device are connected to each other. Compared with the case where it is provided in the cooling water circuit of the system, the flow rate of the cooling water circulating through the circuit while passing through the heat source device is reduced. For this reason, it can be said that the temperature of the second cooling water used for the intercooler 28 can be raised quickly after the start of the engine warm-up operation. Thereby, as can be seen from a comparison between FIG. 2A and FIG. 2B, the temperature of the second cooling water is set as described above in consideration of the suppression of the generation of condensed water. The timing to reach β can be advanced.

  As a result, when the engine is warmed up, the timing at which the introduction of the EGR gas can be started can be advanced without being affected by the temperature rise of the first cooling water on the engine body 10a side and without concern about the occurrence of condensed water. For this reason, the fuel consumption improvement effect by introduction of EGR gas can be heightened. In addition, the system includes a second heater core 82 that uses the second cooling water. As a result, compared to the case where only the first cooling water, which has a relatively large amount of cooling water and takes a long time to rise, is used, the vehicle interior heater is moved earlier after the cold start (that is, the temperature of the first cooling water is sufficiently high). It can be used even when it is not warm.

  In the present embodiment, the target temperature β of the second cooling water used during the engine warm-up operation is equivalent to the lowest temperature at which condensed water is not generated in the intercooler 28, the EGR cooler 38, and the EGR valve body 40a. If the target temperature β is increased without consideration for such setting, the intake air temperature increases due to a decrease in the cooling capacity of the intercooler, and the intake charging efficiency decreases. From the above, according to the above settings, the temperature of the second cooling water is controlled to a temperature at which the condensed water does not occur at the above-mentioned location while minimizing the influence on the intake charging efficiency during the engine warm-up operation. can do.

  By the way, in Embodiment 1 mentioned above, the 1st main cooling water flow path 70 was provided with the 1st heater core 62, and the 2nd main cooling water flow path 90 was described taking the example of the composition provided with the 2nd heater core 82 as an example. . However, the internal combustion engine system with a supercharger according to the present invention is not necessarily limited to the one having the structure having the heater core in each of the two cooling systems, for example, only on the first cooling water circuit 60 side. A structure having a heater core may be provided.

Embodiment 2. FIG.
Next, Embodiment 2 of the present invention will be described with reference mainly to FIG. 3 and FIG.
The internal combustion engine system of the present embodiment performs the control described below using the system configuration of the internal combustion engine 10 of the first embodiment described above.

  FIG. 3 is a time chart for explaining an outline of characteristic cooling water temperature control in Embodiment 2 of the present invention. This control is for increasing the performance of the vehicle interior heater (the temperature of the hot air blown into the vehicle interior) using the system configuration of the first embodiment.

  Specifically, when the required degree of heating using the vehicle interior heater by the vehicle user is high, the required degree of heating is low as the target temperature of the second cooling water at the start of the engine warm-up operation The target temperature γ that is higher than the target temperature β used in the above is used. Accordingly, as shown in FIG. 3, the second switching valve 88 is kept closed even after the temperature of the second cooling water reaches the target temperature β. Thereby, the temperature of the 2nd cooling water is further raised rather than (beta).

  After the temperature of the second cooling water reaches the target temperature γ, the temperature of the second cooling water is controlled so as to maintain the target temperature γ. Such control can be performed, for example, by adjusting the discharge flow rate of the second water pump 86 or controlling the third switching valve 98 of the exhaust heat recovery device 94 as described in the first embodiment.

  Thereafter, when the temperature of the first cooling water reaches a temperature α that can meet the high heating requirement, the target temperature of the second cooling water is changed from γ to β at normal time (when the degree of heating requirement is low). The Along with this, the second switching valve 88 is opened, and the temperature of the second cooling water is lowered. Thereafter, as a method for maintaining the temperature of the second cooling water at the target temperature β, for example, the method described in the first embodiment can be used.

  FIG. 4 is a flowchart showing a routine executed by the ECU 50 in order to realize the coolant temperature control in the second embodiment of the present invention. In addition, this routine shall be repeatedly performed for every predetermined | prescribed control period.

  In the routine shown in FIG. 4, the ECU 50 first detects the outside air temperature and the outside air humidity using the intake air temperature sensor 20 and the intake air humidity sensor 22 (step 100). Next, the ECU 50 determines whether or not the heating requirement level (heater requirement level) is higher than a predetermined level (step 102). Such a determination can be made based on, for example, whether or not the set temperature in the passenger compartment by the air conditioning switch 58 is higher than a predetermined temperature.

  If it is determined in step 102 that the degree of required heating is low, the ECU 50 controls the second coolant temperature so as to reach the target temperature β (step 104). The ECU 50 acquires the target temperature β corresponding to the outside air condition acquired in step 100 and the engine operating condition according to a map (not shown) set in advance, and uses it for the processing in this step 104.

  On the other hand, when it determines with the request | requirement degree of heating being high in step 102, ECU50 determines whether the temperature of 1st cooling water is lower than target temperature (alpha) next (step 106). As a result, the ECU 50 executes the process of step 104 when the temperature of the first cooling water has reached the target temperature α, and when the temperature of the first cooling water has not yet reached the target temperature α. Goes to step 108. In step 108, the ECU 50 controls the second cooling water temperature so as to be the target temperature γ (> β). The target temperatures α and γ used in these steps 106 and 108 vary depending on the outside air condition, the engine operating condition, and the heating requirement. Therefore, the ECU 50 acquires target temperatures α and γ according to the outdoor air condition, the engine operating condition, and the required heating degree according to a preset map (not shown), and performs the processing of steps 106 and 108, respectively. Use.

  According to the routine shown in FIG. 4 described above, the target temperature of the second cooling water during the engine warm-up operation is set when the required degree of heating using the vehicle interior heater is high when the internal combustion engine 10 is cold-started. Until the temperature of the first cooling water rises to a temperature α that can respond to a high heating requirement, the temperature of the first cooling water is increased as compared to the case where the degree of heating requirement is low. Thereby, compared with the case where this control is not performed, the amount of heat introduced into the second heater core 82 is increased, so that warm air can be blown out early into the vehicle interior. Thus, according to this control, the performance of the vehicle interior heater can be improved as necessary when the engine is warmed up.

  By the way, in the first and second embodiments described above, an example in which the EGR cooler 38 and the EGR valve body 40a together with the intercooler 28 are subject to circulation of the second cooling water by the second main cooling water flow path 90 will be described. It was. However, the circulation target of the second cooling water by the second main cooling water channel in the present invention may be only the intercooler. Alternatively, only one of the EGR cooler and the EGR valve body may be the circulation target of the second cooling water together with the intercooler.

  In the first and second embodiments described above, the internal combustion engine 10 including the compressor 24a of the turbocharger 24 has been described as an example. However, the supercharged internal combustion engine system that is the subject of the present invention may be provided with a compressor other than the turbocharger 24. Such a compressor corresponds to, for example, an electric compressor or a compressor of a mechanical supercharger that uses power from a crankshaft.

  In the first and second embodiments described above, the internal combustion engine 10 in which the first water pump 66 is driven at the start of the engine warm-up operation using the power from the crankshaft will be described as an example. It was. However, in relation to the first embodiment, the drive of the first water pump is not necessarily performed at the start of the engine warm-up operation. That is, in relation to the first embodiment, an internal combustion engine system having a configuration in which the drive of the first water pump is stopped at the start of the engine warm-up operation may be intended in order to further improve fuel efficiency. Furthermore, by applying such an internal combustion engine system, the cooling of the turbine housing is carried by the first cooling water, and the first cooling is performed with a small amount sufficient to cool the turbine housing at the start of the engine warm-up operation. It is good also as a structure which circulates water. In the case of such a configuration, only the exhaust heat recovery device is used as the “heat source device” of the present invention. In contrast to such a configuration, an internal combustion engine system including a turbocharger compressor may include only the turbocharger turbine as the “heat source device”.

  Moreover, in Embodiment 1 and 2 mentioned above, the electronic thermostat was taken up as a specific example of the 2nd switching valve 88 for 2nd cooling water. However, the second switching valve 88 is not limited to a valve that is set to be closed at the start of the engine warm-up operation using a thermostat such as an electronic thermostat, that is, for example, to be closed at the start of the engine warm-up operation. It may be a controlled valve (such as a solenoid valve). In relation to the first embodiment, the second switching valve 88 may use a general thermostat that is not an electronic thermostat that can be arbitrarily opened and closed.

  Moreover, in Embodiment 1 and 2 mentioned above, the flow path form of the 2nd cooling water is selected so that the 2nd non-bypass flow path form may be used, the 2nd water pump 86 is driven, and it is a heat source apparatus. The engine warm-up operation after the cold start of the internal combustion engine 10 is started in a state where the heat of a certain exhaust heat recovery device 94 is allowed to be recovered by the second cooling water. However, the operation related to the engine warm-up operation according to the present invention is not limited to the operation performed at the start of the engine warm-up operation as described above, and may be performed from the middle after the engine warm-up operation is started. Good.

DESCRIPTION OF SYMBOLS 10 Internal combustion engine 10a Engine main body 12 Intake passage 14 Exhaust passage 16 Air cleaner 18 Air flow meter 20 Intake temperature sensor 22 Intake humidity sensor 24 Turbo supercharger 24a Compressor 24b Turbine 24b1 Turbine housing 26 Throttle valve 28 Intercooler 30 Exhaust purification catalyst 32 Muffler 34 EGR device 36 EGR passage 38 EGR cooler 40 EGR valve 40a EGR valve body 50 ECU (Electronic Control Unit)
52 Crank Angle Sensor 54 Fuel Injection Valve 56 Ignition Device 58 Air Conditioning Switch 60 First Cooling Water Circuit 62 First Heater Core 64 First Radiator 66 First Water Pump 68 First Switching Valve 70 First Main Cooling Water Channel 72 First Bypass Flow Path 74 first water temperature sensor 80 second cooling water circuit 82 second heater core 84 second radiator 86 second water pump 88 second switching valve 90 second main cooling water flow path 92 second bypass flow path 94 exhaust heat recovery device 96 first 2 Water temperature sensor 98 Second switching valve

Claims (7)

A first radiator that cools a first coolant that cools an engine body that is a body of an internal combustion engine;
A first main cooling water flow path for circulating the first cooling water between the engine body and the first radiator;
A compressor that is disposed in the intake passage and supercharges gas flowing through the intake passage;
An EGR device that has an EGR passage that connects the intake passage and the exhaust passage upstream of the compressor, and that supplies part of the exhaust gas flowing through the exhaust passage to the intake passage;
An intercooler that is disposed in the intake passage downstream of the compressor and exchanges heat between the gas compressed by the compressor and the second cooling water that cools the gas;
A heat source device serving as a heat source for the second cooling water;
A second radiator for cooling the second cooling water;
A second main cooling water flow path for circulating the second cooling water between the intercooler, the heat source device, and the second radiator;
A first water pump installed in the first main cooling water flow path and pumping the first cooling water;
A second water pump that is installed in the second main cooling water flow path and pumps the second cooling water;
A first bypass flow path that branches from the first main cooling water flow path on the upstream side of the first radiator, and merges with the first main cooling water flow path on the downstream side of the first radiator;
A second bypass flow path that branches from the second main cooling water flow path upstream from the second radiator and merges with the second main cooling water flow path downstream from the second radiator;
A first non-bypass flow path configuration in which the first cooling water passes through the first radiator, and the first cooling water passes through the first bypass flow path so that the first cooling water passes through the first radiator. A first switching valve that switches a flow path form of the first cooling water between a first bypass flow path form that does not pass;
A second non-bypass flow path configuration in which the second cooling water passes through the second radiator; and the second cooling water passes through the second bypass flow path so that the second cooling water passes through the second radiator. A second switching valve for switching the flow path configuration of the second cooling water with a second bypass flow channel configuration that does not pass through;
With
When the compressor is a turbocharger compressor, the heat source device includes at least one of a turbine of the turbocharger and an exhaust heat recovery unit that performs heat exchange between the exhaust gas and the second cooling water. Including one or, if the compressor is a compressor of a turbocharger of a type other than the turbocharger, including the exhaust heat recovery device,
The flow path configuration of the second cooling water is selected to use the second non-bypass flow path configuration, the second water pump is driven, and the heat of the heat source device is recovered by the second cooling water. The internal combustion engine system with a supercharger is characterized in that an engine warm-up operation after a cold start of the internal combustion engine is performed in a state where it is permitted to perform the operation. A first and a second heater core functioning as a heat source for a vehicle interior heater of a vehicle equipped with an internal combustion engine;
The first heater core is installed in the middle of the first main cooling water flow path,
2. The internal combustion engine system with a supercharger according to claim 1, wherein the second heater core is installed in the middle of the second main cooling water flow path. When the engine warm-up operation is performed, the first water pump is driven in a state where the flow path configuration of the first cooling water is selected so as to use the first bypass flow path configuration,
When the required degree of heating using the vehicle interior heater is high, the target temperature of the second cooling water during the engine warm-up operation is a temperature at which the temperature of the first cooling water can meet the heating request. The internal combustion engine system with a supercharger according to claim 2, wherein the heating degree is increased as compared with a case where the required degree of heating is low. The EGR device includes an EGR cooler that cools EGR gas flowing through the EGR passage,
The internal combustion engine system with a supercharger according to any one of claims 1 to 3, wherein the EGR cooler is installed in the middle of the second main cooling water flow path. The EGR device includes an EGR valve that adjusts an amount of EGR gas flowing through the EGR passage,
The supercharged internal combustion engine system according to any one of claims 1 to 4, wherein an EGR valve body of the EGR valve is installed in the middle of the second main cooling water flow path. The EGR device includes an EGR cooler that cools EGR gas flowing through the EGR passage, and an EGR valve that adjusts the amount of EGR gas flowing through the EGR passage,
The EGR cooler and the EGR valve body of the EGR valve are installed in the middle of the second main cooling water flow path,
The target temperature of the second cooling water during the engine warm-up operation is a minimum temperature at which condensed water is not generated in the intercooler, the EGR cooler, and the EGR valve body, or a predetermined margin is given to the minimum temperature. The internal combustion engine system with a supercharger according to any one of claims 1 to 5, wherein the internal combustion engine system has a high temperature.   2. The first main cooling water channel and the second main cooling water channel are configured such that a capacity of the second cooling water is smaller than a capacity of the first cooling water. The internal combustion engine system with a supercharger as described in any one of -6.

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