Cooling device for a turbocharged internal combustion engine

Abstract

Cooling device (30) for a turbocharged internal combustion engine (10), wherein the turbocharged internal combustion engine (10) comprises: a cylinder head (18) with an exhaust port (18C); a turbocharger (12) comprising a compressor (12a) arranged in an inlet channel (22) and a turbine (12b) arranged on a downstream side of the outlet opening (18C) in an outlet channel (24) which includes a channel in the outlet opening (18C); and a charge air cooler (26) which is arranged on a downstream side of the compressor (12a) in the inlet channel (22), the cooling device (30) comprises: a high-temperature side cooling circuit (32) comprising a high-temperature side pump (36) configured to circulate a high-temperature coolant, and an HT cooler (38) acting as a high-temperature side cooling section, configured to cool the high-temperature coolant, wherein the high-temperature side cooling circuit (32) is configured to supply the high-temperature coolant to the cylinder head (18); a low-temperature side cooling circuit (34) comprising a low-temperature side pump (62) configured to circulate a low-temperature coolant, and an LT cooler (64) acting as a low-temperature side cooling section, configured to cool the low-temperature coolant, wherein the low-temperature side cooling circuit (34) is configured to supply the low-temperature coolant to the charge air cooler (26); and an electronic control unit (70), where the high-temperature cooling section and the low-temperature cooling section are at least partially used together, comprising the high-temperature cooling circuit (32), a first coolant channel (54) in which the high-temperature coolant flows around the outlet opening (18C), a second coolant channel (56) in which the high-temperature coolant flows through the cylinder head (18) without flowing around the exhaust port (18C), and a flow rate control valve (58) configured to control the flow rate of the high-temperature coolant flowing through the first coolant channel (54), and wherein the electronic control unit (70) is configured to perform a response improvement process for controlling the flow rate control valve (58) in at least part of an acceleration period from the start of acceleration of a vehicle containing the turbocharged internal combustion engine (10) to the end of acceleration, in order to reduce the flow rate of the high-temperature coolant flowing through the first coolant channel (54), characterized by the fact that the electronic control unit (70) is configured to control the low-temperature side pump (62) to increase the flow rate of the low-temperature coolant circulating through the low-temperature side cooling circuit (34), wherein the electronic control unit (70) is configured to control the flow rate control valve (58) during the response improvement process to stop the flow of high-temperature coolant through the first coolant channel (54), and wherein the electronic control unit (70) is configured to control the low-temperature side pump (62) during the response improvement process by increasing the flow rate of the low-temperature coolant in order to increase the cooling capacity of the low-temperature side cooling circuit (34) by an amount corresponding to a decrease in the cooling capacity of the high-temperature side cooling circuit (32) in response to a decrease in the amount of heat absorbed by the high-temperature coolant from the exhaust gas via the outlet opening (18C).

Description

BACKGROUND OF THE INVENTION 1. Field of the invention

[0001] The present invention relates to a cooling device for a turbocharged internal combustion engine according to the preamble of independent claims 1 and 2. 2. Description of the state of the art

[0002] Japanese patent application JP 2010-48187A discloses a turbocharger system for an internal combustion engine. The internal combustion engine comprises an internal coolant channel within a turbine housing and a flow control valve configured to regulate the flow rate of coolant through the internal coolant channel. In the turbocharger system, the flow control valve closes when an acceleration state of the internal combustion engine is detected. As a result, a drop in exhaust gas temperature is suppressed, and exhaust gas energy is increased. Therefore, the transient response of the turbocharger during acceleration is improved.

[0003] A cooling device for a turbocharged internal combustion engine according to the preamble of claims 1 and 2 is the subject of JP 2014 - 20 288 A. Further prior art relating to turbocharged internal combustion engines can be found in JP 2015 - 108 337 A and DE 10 2018 107 317 A1. SUMMARY OF THE INVENTION

[0004] Generally, coolant is supplied around the exhaust port of a cylinder head. Therefore, the exhaust temperature (gas temperature) decreases as the exhaust gas flows through the exhaust port before reaching a turbine. The technology described in JP 2010-48187A offers potential for further improvement in the acceleration performance of the vehicle, which includes the turbocharged internal combustion engine.

[0005] The present invention was made with regard to the problem described above and aims to provide a cooling device for a turbocharged internal combustion engine, thereby improving the acceleration performance of a vehicle. This objective is achieved by the features of independent claims 1 and 2; an advantageous embodiment is the subject of the dependent claim.

[0006] One aspect of the present invention relates to a cooling device for a turbocharged internal combustion engine, comprising a cylinder head, a turbocharger, and an intercooler. The cylinder head includes an exhaust port. The turbocharger comprises a compressor arranged in an intake port and a turbine arranged on a downstream side of the exhaust port in an exhaust port, which includes a channel in the exhaust port. The intercooler is arranged on a downstream side of the compressor in the intake port. The cooling device comprises a high-temperature cooling circuit, a low-temperature cooling circuit, and an electronic control unit. The high-temperature cooling circuit includes a high-temperature pump configured to circulate a high-temperature coolant.The system comprises a high-temperature-side cooling circuit, configured to cool the high-temperature coolant, and a high-temperature-side cooling section configured to cool the high-temperature coolant, the high-temperature-side cooling circuit being configured to supply the high-temperature coolant to the cylinder head. The low-temperature-side cooling circuit comprises a low-temperature-side pump configured to circulate a low-temperature coolant, and a low-temperature-side cooling section configured to cool the low-temperature coolant, the low-temperature-side cooling circuit being configured to supply the low-temperature coolant to the charge air cooler. The high-temperature-side cooling section and the low-temperature-side cooling section are at least partially shared.The high-temperature side cooling circuit comprises a first coolant channel in which the high-temperature coolant flows around the outlet opening, a second coolant channel in which the high-temperature coolant flows through the cylinder head without flowing around the outlet opening, and a flow control valve configured to adjust the flow rate of the high-temperature coolant flowing through the first coolant channel.The electronic control unit is configured to perform a response improvement process for controlling the flow control valve to reduce the flow rate of the high-temperature coolant flowing through the first coolant channel and for controlling the low-temperature side pump to increase the flow rate of the low-temperature coolant circulating through the low-temperature side cooling circuit during at least part of an acceleration period from the start of acceleration of a vehicle containing the turbocharged internal combustion engine to the end of acceleration.

[0007] In the cooling device according to claim 1, the electronic control unit is configured to control the flow rate control valve during the response improvement process in order to stop the flow of the high-temperature coolant through the first coolant channel.

[0008] In the cooling device according to claim 2, the electronic control unit is configured such that, during the response improvement process, it controls the low-temperature side pump in such a way as to increase the flow rate of the low-temperature coolant when a decrease in the flow rate of the high-temperature coolant flowing through the first coolant channel increases.

[0009] According to the invention, the electronic control unit is configured such that, during the response improvement process, it controls the low-temperature side pump to increase the flow rate of the low-temperature coolant in order to increase the cooling capacity of the low-temperature side cooling circuit by an amount corresponding to a decrease in the cooling capacity of the high-temperature side cooling circuit in response to a decrease in the amount of heat absorbed by the high-temperature coolant from the exhaust gas via the outlet opening.

[0010] In the cooling system, as described above, the turbocharged internal combustion engine may also include an ignition device. The electronic control unit can be configured to control the ignition device during the response improvement process, advancing the ignition timing in response to an increase in the flow rate of the low-temperature coolant.

[0011] In the cooling device according to the invention, the response improvement process is carried out during at least part of the acceleration period. During this process, the flow control valve is controlled to constrict the first coolant channel. This reduces the amount of heat absorbed by the high-temperature coolant from the exhaust gas via the outlet, thereby suppressing a drop in exhaust gas temperature (exhaust gas energy). This allows the intake air volume to be increased due to the boost pressure. The high-temperature and low-temperature cooling sections are at least partially shared. Therefore, a portion of the cooling capacity of the high-temperature cooling circuit, resulting from the reduction in the amount of heat absorbed by the high-temperature coolant, can be attributed to the cooling capacity of the low-temperature cooling circuit.The cooling capacity for the intake air can be increased by increasing the flow rate of the low-temperature coolant. The responsiveness of the cooling system for the turbocharged combustion engine can improve the vehicle's acceleration. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] The features and advantages as well as the technical and economic significance of exemplary embodiments of the invention are described below with reference to the accompanying drawings, in which the same reference numerals denote the same elements, showing: Fig. 1 a schematic representation showing the system configuration of a turbocharged internal combustion engine according to a first embodiment of the present invention; Fig. 2 a schematic representation that provides an example of the in Fig. Figure 1 shows the structures of coolant channels around a cylinder head; Fig. 3 a flowchart illustrating an example of the sequence of a response improvement process during acceleration according to the first embodiment; Fig. 4 a graph that represents a relationship between the cooling capacity of a high-temperature cooling circuit (HT cooling circuit) in relation to an internal combustion engine load and a high-temperature flow rate (HT flow rate) in a turbocharged internal combustion engine; Fig. 5 a graph illustrating the cooling performance of the HT cooling circuit and a low temperature cooling circuit (LT cooling circuit) in the turbocharged internal combustion engine; Fig. 6 a graph showing the relationship between the permissible cooling capacity in relation to the combustion engine load and the airflow (wind volume) in the turbocharged combustion engine; Fig. 7 a graph that shows a relationship between the cooling capacity of the low-temperature cooling circuit (LT cooling circuit) in relation to the internal combustion engine load and the low-temperature flow rate (LT flow rate) in the turbocharged internal combustion engine; Fig. 8 a graph that represents a relationship between an ignition timing in relation to the combustion engine load and an intake temperature in the turbocharged combustion engine; Fig. 9 a time diagram to describe processes during acceleration together with the response improvement process according to the first embodiment; and Fig. 10 a flowchart illustrating an example of a response improvement process during acceleration according to a second embodiment of the present invention. DETAILED DESCRIPTION OF EXECUTION FORMS

[0013] When the number, quantity, amount, range, or other numerical value of each element is described in the first and second embodiments described below, the present invention is not limited to the described numerical value unless otherwise noted or the numerical value is definitively determined in theory. Structures and steps described in the first and second embodiments are not necessarily essential to the present invention unless otherwise noted or the structures and steps are definitively required in theory.

[0014] The first embodiment of the present invention is described. Example of a system configuration

[0015] Fig. Figure 1 is a schematic representation of the system configuration of a turbocharged internal combustion engine 10 according to the first embodiment. The in Fig. The turbocharged internal combustion engine 10 shown in Figure 1 is an internal combustion engine with a turbocharger 12. More precisely, the turbocharged internal combustion engine 10 is, for example, a gasoline engine. The turbocharged internal combustion engine 10 comprises an engine block 14. The engine block 14 includes a cylinder block 16 and a cylinder head 18.

[0016] The cylinder head 18 comprises a combustion chamber cover 18a, intake ports 18b and exhaust ports 18c. An intake port 22 and an exhaust port 24 are connected to a combustion chamber 20 (see Fig. 2) of the turbocharged internal combustion engine (hereinafter also referred to simply as "engine") 10 in conjunction. The intake port 22 includes passages in the intake openings 18b. The exhaust port 24 includes channels or passages in the exhaust openings 18c.

[0017] The turbocharger 12 comprises a compressor 12a and a turbine 12b. The compressor 12a is located in the intake channel 22 and is coupled to the turbine 12b via a coupling shaft 12c. The turbine 12b is located in the exhaust channel 24 downstream of the exhaust ports 18c and is set in rotation by the exhaust gas expelled from the exhaust ports 18c. The compressor 12a is set in rotation by the turbine 12b to compress the intake air.

[0018] An intercooler 26 is located downstream of the compressor 12a in the intake duct 22. The intercooler 26 cools the intake air compressed by the compressor 12a. The intercooler 26 is a water-cooled intercooler, as described later. An electronically controlled throttle valve 28 is located downstream of the intercooler 26. The intake air volume is controlled by adjusting the opening degree of the throttle valve 28. To control the boost pressure, the internal combustion engine 10 can include a wastegate mechanism or a variable nozzle mechanism.

[0019] The turbocharged internal combustion engine 10 includes a cooling device 30. The cooling device 30 comprises a high-temperature (HT) cooling circuit 32 and a low-temperature (LT) cooling circuit 34. The HT cooling circuit 32 supplies the internal combustion engine body 14 with the cylinder head 18 with coolant. The LT cooling circuit 34 supplies the coolant to the charge air cooler 26. Since the HT cooling circuit 32 cools the internal combustion engine body 14, which has a higher temperature than that of the charge air cooler 26, the coolant flowing through the HT cooling circuit 32 is referred to as the "high-temperature coolant (HT coolant)." The coolant flowing through the LT cooling circuit 34 is referred to as the "low-temperature coolant (LT coolant)."

[0020] Next, the high-temperature (HT) cooling circuit is described. The HT cooling circuit 32 comprises a high-temperature pump (HT pump) 36 and a high-temperature radiator (HT radiator) 38. The HT pump 36 circulates the HT coolant through the HT cooling circuit 32. The HT pump 36 is, for example, mounted on the cylinder block 16 and is rotated by the crankshaft of the internal combustion engine 10. The HT radiator 38 cools the HT coolant by heat exchange with air (ambient air).

[0021] The high-temperature coolant pumped by the HT pump 36 flows through the cylinder block 16, the cylinder head 18, and the HT radiator 38 in this sequence. A specific example of the coolant channel structures of the HT coolant around the cylinder head 18 is given with reference to Fig. 2 together with Fig. 1 described.

[0022] Fig. Figure 2 is a schematic representation showing the example of the structures of the coolant channels around the cylinder head 18. Fig. Figure 2 shows the internal structure of the internal combustion engine block 14 as seen in the axial direction of the crankshaft. The HT cooling circuit 32 comprises an internal water jacket (WJ) 40, an intermediate intake valve WJ 42, an intermediate exhaust valve WJ 44, an upper exhaust port WJ 46, and a lower exhaust port WJ 48. The internal water jacket WJ 40 is formed on the outer circumference of the cylinder bores in the cylinder block 16. Fig. Sections of the block-internal WJ 40 are connected to each other on an intake side and an exhaust side in a circumferential direction of each cylinder bore. The intermediate intake valve WJ 42 is formed between adjacent intake valves 50, which are arranged along the axial direction of the crankshaft. Similarly, the intermediate exhaust valve WJ 44 is arranged between adjacent exhaust valves 52. The upper exhaust port WJ 46 and the lower exhaust port WJ 48 are formed above and below the exhaust ports 18c (i.e., around the exhaust ports 18c).

[0023] The HT cooling circuit 32 comprises a first coolant channel 54 and a second coolant channel 56, formed using the block-internal WJ 40, the intermediate intake valve WJ 42, the intermediate exhaust valve WJ 44, the upper exhaust port WJ 46, and the lower exhaust port WJ 48 as its main components. The first coolant channel 54 is a path along which the HT coolant flows around the exhaust ports 18c (broad solid arrows). The second coolant channel 56 is a path along which the HT coolant flows through the cylinder head 18 without flowing around the exhaust ports 18c (broad dashed arrows). More precisely, the second coolant channel 56 is a path by which the HT coolant flows through the cylinder head 18 at a point that is separate from the exhaust ports 18c, and not around the exhaust ports 18c.

[0024] The high-temperature (HT) cooling circuit 32 further includes a flow control valve 58 configured to regulate the flow rate of the HT coolant flowing through the first coolant channel 54. The flow control valve 58 is, for example, an electric valve and can modify the flow rate of the HT coolant flowing around the outlet ports 18c (including zero, i.e., a flow-stop state). The flow control valve 58 is, for example, located in the first coolant channel 54 on a part situated outside the cylinder head 18.

[0025] The high-temperature (HT) coolant flowing from the HT pump 36 into the intake side of the in-block WJ 40 splits into two paths: one leading to the intermediate intake valve WJ 42, and the other flowing through the in-block WJ 40 from the intake side to the exhaust side along the cylinder bores, then to the exhaust side of the cylinder head 18. The subsequent path of the HT coolant varies depending on whether the flow control valve 58 is open or closed.

[0026] First, the high-temperature (HT) coolant flows around the cylinder head 18 are described with the flow control valve 58 open. In this open state, the HT coolant flowing through the intermediate inlet valve WJ 42 branches into one path leading to the upper outlet port WJ 46 and another path 60 flowing out of the cylinder head 18 without passing through the upper outlet port WJ 46. The HT coolant flowing from the outlet side of the block-integrated valve WJ 40 into the outlet side of the cylinder head 18 branches into one path leading to the intermediate outlet valve WJ 44 and another path leading to the lower outlet port WJ 48. The HT coolant flowing through the intermediate outlet valve WJ 44 branches into path 60 and the path along which the HT coolant flows to the upper outlet opening WJ 46.The streams of HT coolant flowing from the upper outlet opening WJ 46 and the lower outlet opening WJ 48 combine, flow through the flow control valve 58 and merge with the HT coolant flowing through path 60.

[0027] When open, the HT coolant flows through both the first coolant channel 54 and the second coolant channel 56. As in Fig. As shown in Figure 2, the high-temperature coolant flows in the first coolant channel 54 around the outlet openings 18c (upper outlet opening WJ 46 and lower outlet opening WJ 48) and through the flow control valve 58 in that order. The high-temperature coolant in the second coolant channel 56 flows through the intermediate inlet valve WJ 42 and path 60, as well as through the intermediate outlet valve WJ 44 and path 60.

[0028] When the flow control valve 58 is closed, the high-temperature coolant stops flowing around the outlet openings 18c (upper outlet WJ 46 and lower outlet WJ 48). In the closed state, the high-temperature coolant does not flow through the first coolant channel 54, but only through the second coolant channel 56. In the closed state, the high-temperature coolant stagnates around the outlet openings 18c. Therefore, the high-temperature coolant no longer cools the outlet openings 18c (cooling is at least sufficiently suppressed) and continues to cool the areas around the combustion chamber roof 18a and the inlet openings 18b.Instead of the example where the flow control valve 58 is closed (fully closed), the degree of opening of the flow control valve 58 can be reduced to decrease the flow rate of the HT coolant flowing around the outlet openings 18c, thereby reducing the amount of heat absorbed by the HT coolant from the exhaust gas via the outlet openings 18c.

[0029] The structures of the first and second coolant channels are not based on the structures of the one in Fig. 1 and Fig. The possibilities are limited to the example shown in Figure 2. That is, the first coolant channel can be structured arbitrarily as long as the high-temperature coolant flows around the exhaust ports, and the second coolant channel can be structured arbitrarily as long as the high-temperature coolant flows through the cylinder head without flowing around the exhaust ports. For example, the first and second coolant channels can be designed such that the high-temperature coolant does not branch within the cylinder head 18, but branches completely as it flows from the cylinder block into the cylinder head.

[0030] Any flow control valve can be used, as long as the valve can regulate the flow rate of the high-temperature coolant flowing through the first coolant channel. The arrangement and design of the flow control valve are not limited to those mentioned in the example of flow control valve 58.

[0031] Next, the NT cooling circuit will be described. As in Fig. As shown in Figure 1, the low-temperature (LT) cooling circuit 34 comprises a low-temperature pump (LT pump) 62 and a low-temperature cooler (LT cooler) 64. The LT pump 62 circulates the LT coolant through the LT cooling circuit 34. The LT pump 62 is, for example, an electric pump. The LT pump 62 is arranged, for example, between an inlet of the charge air cooler 26 and an outlet of the LT cooler 64, and its position is not particularly limited. The LT cooler 64 cools the LT coolant by heat exchange with air (ambient air). Although in Fig. Not shown, the NT cooling circuit 34 can also cool the turbocharger (T / C) 12, as in a later described example by Fig. 5.

[0032] Next, the shared use of a high-temperature cooling section and a low-temperature cooling section is described. As in Fig. As shown in Figure 1, the vehicle with the turbocharged internal combustion engine 10 includes a condenser 66. The condenser 66 is a component of a cooling circuit for the air conditioning of a vehicle cabin and is a heat exchanger configured to cool and condense a refrigerant (air conditioning refrigerant) flowing through the cooling circuit. In particular, the condenser 66 cools the air conditioning refrigerant by heat exchange with air (outside air).

[0033] In this embodiment, the condenser 66 is designed such that the high-temperature (HT) coolant in the HT cooling circuit 32 can exchange heat with the air conditioning refrigerant in the condenser 66. More precisely, the HT cooling circuit 32, as shown in Fig. As shown in Figure 1, the system is configured such that the high-temperature (HT) refrigerant flowing through the HT cooler 38 flows through the condenser 66 and then back through the HT cooler 38. Similarly, the condenser 66 is configured so that the low-temperature (LT) refrigerant in the low-temperature (LT) cooling circuit 34 can exchange heat with the air conditioning refrigerant in the condenser 66. More precisely, the LT cooling circuit 34 is configured such that the LT refrigerant flowing through the LT cooler 64 flows through the condenser 66 and then back through the LT cooler 64.

[0034] As in Fig. As shown in Figure 1, the condenser 66 is mounted on the vehicle on the upstream side of the airflow (the airflow generated by the vehicle's movement) with respect to the high-temperature (HT) cooler 38 and the low-temperature (LT) cooler 64. The HT cooler 38 and the LT cooler 64 are arranged orthogonally to the direction of airflow. During vehicle movement, the refrigerant, the HT coolant, and the LT coolant in the condenser 66 are cooled by the airflow. In the HT cooler 38, the HT coolant is further cooled by the airflow that has passed through the condenser 66. Similarly, in the LT cooler 64, the LT coolant is further cooled by the airflow that has passed through the condenser 66.

[0035] In the Fig. In the configuration example shown in Figure 1, the HT cooler 38 is an example of a "high-temperature-side cooling section" according to the present invention. The LT cooler 64 is an example of a "low-temperature-side cooling section" according to the present invention. The HT refrigerant and the LT refrigerant, which are introduced into the structured condenser 66 as described above, are cooled in the condenser 66 and exchange heat with each other via the air conditioning refrigerant, both while the cooling circuit is in operation (an air conditioner is running) and also when it is at rest. In the configuration example shown in Figure 1, the HT cooler 38 is an example of a "high-temperature-side cooling section" according to the present invention. Fig. In the configuration example shown in 1, the “high-temperature side cooling section” and the “low-temperature side cooling section” are partially shared by the condenser 66.

[0036] The “high-temperature cooling section” and the “low-temperature cooling section” can be used instead of the one in Fig. The cooling system can be divided as follows, as shown in the example in Figure 1. For example, the low-temperature coolant can flow through a portion of the high-temperature-side cooler, corresponding to the "high-temperature-side cooling section." Conversely, the high-temperature coolant can flow through a portion of the low-temperature-side cooler, corresponding to the "low-temperature-side cooling section." The "high-temperature-side cooling section" and the "low-temperature-side cooling section" can be used entirely together. For example, the cooler that cools the high-temperature coolant and the cooler that cools the low-temperature coolant can be integrated together.

[0037] Next, an electronic control unit will be described. This is in Fig. The system shown in Figure 1 further comprises an electronic control unit (ECU) 70. The ECU 70 comprises a processor 70a and a memory 70b. The memory 70b stores various control programs and various data types, including maps, for use in controlling the turbocharged internal combustion engine 10, including the control of the cooling device 30. The processor 70a reads the control programs in the memory 70b and executes them to implement various processes and different types of control by the ECU 70. The number of ECUs 70 can be plurality. The ECU 70 corresponds to an example of an "electronic control unit" within the meaning of the present invention.

[0038] The ECU 70 acquires sensor signals from a sensor unit 72 for use in controlling the internal combustion engine 10. The sensor unit 72 comprises various sensors attached to the internal combustion engine 10 (e.g., a crankshaft angle sensor, an internal combustion engine coolant temperature sensor, an airflow sensor, and an intake air temperature sensor) and various sensors attached to the vehicle (e.g., an accelerator pedal position sensor and a vehicle speed sensor). Actuators to be controlled by the ECU 70 include the throttle valve 28, the flow control valve 58, and the LT pump 62, as well as a fuel injection device 74 and an ignition device 76 of the internal combustion engine 10.

[0039] Next, the control system for improving acceleration behavior according to the first embodiment is described. In this embodiment, the ECU 70 performs the following "response improvement process" to improve the acceleration behavior of the vehicle with the turbocharged internal combustion engine 10. In the response improvement process, during an acceleration period TACC from the beginning to the end of the vehicle's acceleration, the ECU 70 controls the flow control valve 58 to achieve a high-temperature (HT) flow rate V. HTex to reduce, and controls the LT pump 62 to achieve an LT flow rate V LT to increase the HT flow rate V HTex is the flow rate of the HT coolant flowing through the first coolant channel 54, where the HT coolant flows around the outlet openings 18c. The LT flow rate V LTis the flow rate of the LT coolant circulating through the NT cooling circuit 34. For example, in this embodiment, the flow rate control valve 58 is controlled such that the flow of the HT coolant through the first coolant channel 54 is stopped.

[0040] More precisely, in the response improvement process of this embodiment, the ECU 70 controls the LT pump 62 to increase the LT flow rate V LT to increase cooling capacity Qw LT to increase the NT cooling circuit 34 by an amount corresponding to a decrease in cooling capacity Qw HT of the HT cooling circuit 32 as a reaction to a decrease in the heat absorption quantity of the HT coolant from the exhaust gas via the outlet openings 18c.

[0041] In the response improvement process of this embodiment, the ECU 70 shifts an ignition timing in response to the increase in the flow rate V. LT of the LT coolant.

[0042] Fig. Figure 3 is a flowchart showing an example of the response improvement process during acceleration according to the first embodiment. The process in this flowchart is repeated during operation of the turbocharged internal combustion engine 10.

[0043] In Fig. In step S100, the ECU 70 first detects the accelerator pedal detent, the engine coolant temperature, and the vehicle speed. The accelerator pedal detent can be detected, for example, using the accelerator pedal position sensor. The engine coolant temperature (HT coolant temperature) can be detected, for example, using the engine coolant temperature sensor mounted on cylinder block 16. The vehicle speed can be detected, for example, using the vehicle speed sensor. The procedure then continues with step S102.

[0044] In step S102, ECU 70 determines whether the vehicle is in the TACC acceleration period (whether the vehicle is in an acceleration state). Vehicle acceleration includes acceleration from a stationary state and acceleration initiated while the vehicle is moving. For example, ECU 70 detects an acceleration request (in other words, it determines that acceleration is starting) when the accelerator pedal detent (accelerator pedal depressor amount) is equal to or greater than a predetermined setpoint. For example, ECU 70 determines that the TACC acceleration period is over when the vehicle speed, as detected by the vehicle speed sensor, reaches a target vehicle speed determined based on the accelerator pedal detent.The method for determining the acceleration period TACC is not limited to this method and can be any generally known method.

[0045] If the ECU 70 detects in step S102 that the acceleration period TACC has not occurred, the ECU 70 terminates the current processing cycle. If the acceleration period TACC has occurred, the procedure continues with step S104.

[0046] In step S104, the ECU 70 calculates a requested combustion engine torque. For example, the requested combustion engine torque is calculated so that it increases with increasing deceleration of the accelerator pedal. The procedure then continues with step S106.

[0047] In step S106, the ECU 70 determines whether the combustion engine coolant temperature (HT coolant temperature) is equal to or lower than a predetermined setpoint TH. The setpoint TH is a threshold value for the combustion engine coolant temperature (e.g., 100°C) used to determine whether the reliability of the exhaust system can be ensured even when the flow control valve 58 is closed to stop the coolant flow around the exhaust ports 18c.

[0048] If the combustion engine coolant temperature in step S106 is higher than the determined value TH, ECU 70 terminates the current processing cycle. More precisely, the response improvement process for the current acceleration period TACC (steps S108 to S112) is not executed if the process first proceeds to step S106 after the acceleration period TACC has begun and the determined value of step S106 is negative. The currently executed response improvement process is halted if the process proceeds to step S106 during an acceleration period TACC and the determined value of step S106 is negative. The response improvement process can be executed using the process of step S106 while ensuring the reliability of the exhaust system.

[0049] If the combustion engine coolant temperature in step S106 is equal to or less than the determined value TH, the procedure continues with step S108. In step S108, the ECU 70 closes the flow control valve 58 to stop the flow of the HT coolant around the outlet ports 18c. The procedure then continues with step S110.

[0050] In step S110, the ECU 70 calculates an increase amount ΔV. LT the LT flow rate V LT to increase cooling capacity Qw LT of the NT cooling circuit 34 by an amount corresponding to a decrease in cooling capacity Qw HT The HT cooler 38 reacts to a decrease in the heat absorption rate of the HT coolant from the exhaust gas via the outlet openings 18c, in conjunction with the process of step S108. The ECU 70 controls the LT pump 62 to increase the calculated amount ΔV. LT increased LT flow rate V LT to achieve. The increase amount ΔVLT This is calculated, for example, when the process transitions to step S110 for the first time after the acceleration period TACC has elapsed. The increase amount ΔV LT can be calculated, for example, by a procedure which is described below with reference to the Fig. 4 to Fig. 7 is described.

[0051] Fig. Figure 4 is a graph that shows a relationship between the cooling capacity Qw HT of the HT cooling circuit 32 in relation to an internal combustion engine load and the HT flow rate V HTex represents. As in Fig. As shown in 4, the cooling capacity Qw takes on HT (kW) of the HT cooling circuit 32 (HT system) increases when the combustion engine load decreases, and it increases when the HT flow rate V HTex increases. Memory 70b stores the data in Fig. 4. Relationship shown as a characteristic curve.

[0052] From the characteristic map, which is in Fig. Based on the relationship shown in section 4, the ECU 70 calculates a cooling capacity Qw. HT 1 based on an internal combustion engine load and an HT flow rate V HTex (value before the flow rate control valve 58 is closed) at a time t1 when the acceleration period TACC has arrived (see Fig. 9) The ECU 70 also calculates a cooling capacity Qw from the characteristic map. HT 2 based on the combustion engine load at time t1 and an HT flow rate V HTex After closing the flow rate control valve 58 (i.e., zero), the ECU 70 calculates a difference ΔQw. HT between the cooling capacities Qw HT 1 and Qw HT 2 (= Qw HT 2 - Qw HT 1) The difference ΔQw HT corresponds to a margin of cooling capacity Qw HT , which is achieved by reducing the HT flow rate V HTexis generated. For example, the combustion engine load (engine load factor based on an intake air boost rate) can be calculated based on an intake air volume derived from an airflow sensor output and a combustion engine speed derived from a crankshaft position sensor output. For example, the HT flow rate V HTex before closing the flow rate control valve 58, the speed of the HT pump 36 is calculated based on the internal combustion engine speed.

[0053] Fig. Figure 5 is a graph showing the cooling capacities Qw of the HT cooling circuit 32 and the NT cooling circuit 34. Fig. Figure 5 shows the relationships between the cooling capacities Qw (kW) of the HT cooling circuit 32 and the NT cooling circuit 34 in two examples. In the first example, the response improvement process is not executed (i.e., the flow control valve 58 is open). In the second example, the response improvement process is executed (i.e., the flow control valve 58 is closed).

[0054] In Fig. 5 corresponds to Qw T a permissible total cooling capacity of the HT cooling circuit 32 and the LT cooling circuit 34. The HT cooler 38 and the LT cooler 64 are cooled by the airflow (cooling air) via the common condenser 66. As in Fig. Figure 5 shows the permissible cooling capacity (total cooling capacity) Qw. Tas the sum of the cooling capacities of the HT cooling circuit 32 and the NT cooling circuit 34. Thus, when the flow control valve 58 is closed by the process of step S108 to stop the cooling around the outlet openings 18c, the cooling capacity, which is the margin ΔQw HT This corresponds to the cooling in the NT cooling circuit 34.

[0055] Fig. Figure 6 is a graph that shows a relationship between the permissible cooling capacity Qw T in relation to the combustion engine load and the driving air (wind volume).

[0056] As in Fig. As shown in section 6, the permissible cooling capacity Qw T The volume decreases when the combustion engine load decreases and increases when the wind volume of the driving air increases. Storage unit 70b stores the energy in Fig. The relationship shown in section 6 is represented as a characteristic map. The ECU 70 calculates a permissible cooling capacity Qw from this characteristic map. TBased on the combustion engine load and a wind volume at time t1, the ECU 70 calculates a difference between the calculated permissible cooling capacity Qw. T and the margin ΔQw HT (= Qw T - Qw HT The difference is called the increase amount ΔQw. LT cooling capacity Qw LT The NT cooling circuit 34 is discussed. The wind volume of the airflow increases with increasing vehicle speed. Therefore, the wind volume can be calculated based on the vehicle speed.

[0057] Fig. Figure 7 is a graph showing the relationship between the cooling capacity Qw LT of the NT cooling circuit 34 and the combustion engine load as well as the LT flow rate V LT shows. As in Fig. As shown in 7, the cooling capacity Qw takes on LT decreases with increasing combustion engine load and increases with increasing LT flow rate V LT Memory 70b stores the data in Fig. The relationship shown in section 7 is represented as a characteristic map. The ECU 70 calculates a cooling capacity Qw from this characteristic map. LT 1 based on the combustion engine load and an LT flow rate V LT 1 at time t1.

[0058] The ECU 70 calculates a cooling capacity Qw LT 2, by increasing the amount ΔQw LT to the calculated cooling capacity Qw LT 1 is added, and an LT flow rate V is calculated from the characteristic map. LT 2 based on the cooling capacity Qw LT 2 and the combustion engine load at time t1. The ECU 70 calculates an increase amount ΔV. LT , which represents a difference between the LT flow rates V LT 1 and V LT 2 is (= V LT 2 - V LT 1) For example, the LT flow rate ΔV LT 1 at time t1 based on a rotational speed of the LT pump 62.

[0059] The quantity of the HT flow rate V that is taken off HTexThe flow rate caused by closing the flow rate control valve 58 increases when the HT flow rate V HTex before the flow rate control valve 58 closes. According to the procedure for calculating the increase amount ΔV LT with reference to Fig. 4 to Fig. 7 the increase amount ΔV LT calculated so that it increases when the quantity of the HT flow rate V decreases. HTex increases.

[0060] In step S112, which follows step S110, the ECU 70 advances the ignition timing along with the increase in the LT flow rate V. LT through the process of step S110. Fig. Figure 8 is a graph illustrating the relationship between ignition timing, combustion engine load, and intake air temperature. As shown in Fig. As shown in Figure 8, the ignition timing is advanced further with decreasing engine load and is advanced further with decreasing intake air temperature. The intake air temperature is the temperature of the intake air that has flowed through the charge air cooler 26. The accumulator 70b stores the in Fig. The relationship shown in Figure 8 is represented as a map. For example, the ECU 70 calculates an ignition timing from the map based on the combustion engine load at time t1 and an intake air temperature (estimated value), after the LT flow rate V has been determined. LT was increased. If the LT flow rate V LT As the process of step S110 increases, the intake air temperature decreases because the cooling of the intake air in the charge air cooler 26 is accelerated. Therefore, the calculated ignition timing is lower compared to the ignition timing before the LT flow rate V LT The value is increased, the forward value.

[0061] The decrease in intake temperature together with the increase in the LT flow rate V LT It generally increases if the increase amount ΔV LT increases. Therefore, the intake air temperature (estimated value) used to determine the amount of ignition timing advance can, for example, be calculated such that it decreases compared to the intake air temperature value at time t1, as detected by the intake air temperature sensor, when the amount of increase ΔV LT increases.

[0062] Fig. Figure 9 is a time diagram describing processes during acceleration together with the response improvement process according to the first embodiment. Fig. 9. The solid lines correspond to the processes of the cooling device of this embodiment during acceleration together with the response enhancement process, and the dashed lines correspond to the processes in a comparative example during acceleration without the response enhancement process. Fig. In section 9, time t0 corresponds to the point in time when the driver begins to depress the accelerator pedal (acceleration request). Time t1 after time t0 corresponds to the point in time when the acceleration request is detected (i.e., the vehicle begins to accelerate). As described above, the acceleration period TACC starts from time t1.

[0063] According to the response improvement process, the flow control valve 58 closes at time t1. As a result, the HT coolant stops flowing around the outlet ports 18c (upper outlet port WJ 46 and lower outlet port WJ 48). Therefore, a decrease in exhaust gas temperature (exhaust gas energy) due to cooling of the outlet ports 18c is suppressed. Thus, the exhaust gas temperature (exhaust gas energy) increases compared to the reference example (dashed line), as shown in Fig. Figure 9 illustrates this. Consequently, the boost pressure can be increased by increasing the turbocharger speed. Since the coolant does not cease flowing around the combustion chamber ceiling 18a and the intake ports 18b, the exhaust energy can be improved without increasing the surface temperature of the combustion chamber 20 (i.e., without increasing the possibility of knocking).

[0064] At time t1, the LT flow rate V LTin conjunction with the interruption of the coolant flow around the outlet openings 18c, the cooling capacity of the charge air cooler 26 for the intake air is increased. Therefore, the intake air temperature decreases compared to the reference example, as shown in Fig. 9 shown.

[0065] As the intake air temperature decreases, the compression end temperature in the cylinder also decreases, thus suppressing knocking. Therefore, the ignition timing at time t1 is adjusted to account for the decrease in intake air temperature along with the increase in the intake air flow rate V. LT The ignition timing is advanced. More precisely, the ignition timing is advanced to approximate an optimal ignition timing (Minimal Advance for Best Torque: MBT).

[0066] By performing the response improvement process, the response behavior of the combustion engine torque is improved, as described in Fig. Figure 9 illustrates this. In particular, the combustion engine torque increases due to an increase in the intake air volume along with the increase in boost pressure, and due to the advance of the ignition timing and the improvement in intake air density along with the reduction in intake air temperature. As a result, acceleration is improved. By advancing the ignition timing to the MBT (Minimum Threshold Time), thermal efficiency is improved.

[0067] In Fig. 9 corresponds to a time t2, a time at which the vehicle speed reaches the target speed, which is based on the amount of accelerator pedal input. In the Fig. In example 9, the response improvement process ends at time t2. This means that the supply of the HT coolant around the outlet openings 18c is resumed after time t2 has passed. In the example shown in Fig. In the example shown in Figure 9, the acceleration period TACC ends at time t2. The time until the vehicle reaches its target speed, which is used as the point at which the response improvement process ends, is not limited to the point at which acceleration stops. That is, in the example where the response improvement process ends, the target vehicle speed to be reached can be a predetermined vehicle speed value during acceleration.

[0068] The response improvement process does not necessarily have to be executed during the entire TACC acceleration period. For example, the response improvement process can be executed during a period from the start of acceleration until a point in time when the accelerator pedal input during acceleration decreases to a predetermined input level that is greater than the input level before acceleration (i.e., the acceleration request level decreases to a certain level or lower after the start of acceleration).

[0069] Next, the effects of the cooling device for the turbocharged internal combustion engine according to the first embodiment are described. As described above, in the response improvement process of the first embodiment, the flow control valve 58 is controlled during the acceleration period TACC to constrict the first coolant channel 54. For example, the flow control valve 58 is closed to stop the coolant flow in the first coolant channel 54. This reduces the amount of heat that the HT coolant absorbs from the exhaust gas via the outlet openings 18c, thus preventing a drop in exhaust gas temperature (exhaust gas energy). This allows the intake air volume to be increased due to an increase in boost pressure. Part of the radiator in the HT cooling circuit 32 (high-temperature side cooling section) is shared with the radiator in the NT cooling circuit 34 (low-temperature side cooling section). Therefore, the margin ΔQw HTcooling capacity Qw HT of the HT cooling circuit 32, which is generated by the reduction in the heat absorption quantity of the HT coolant, the cooling capacity Qw LT of the NT cooling circuit 34. Thus, the cooling capacity for the intake air can be increased by increasing the NT flow rate V. LT This increases the intake air density. According to the response improvement process described above, the vehicle's acceleration behavior can be improved.

[0070] The reduction in exhaust gas temperature is generally greater when passing through the outlet openings 18c than when passing through the turbine 12b. Therefore, suppressing the cooling of the outlet openings 18c by reducing the coolant flow around the outlet openings 18c can suppress the drop in exhaust gas temperature (exhaust gas energy) more effectively than in a case where the cooling of the turbine 12b is suppressed.

[0071] In the response improvement process of the first embodiment, the flow rate V LT of the LT refrigerant increased to improve cooling performance Qw LT to increase the NT cooling circuit 34 by the amount corresponding to the decrease in cooling capacity Qw HT of the HT cooling circuit 32 (margin ΔQw HT ) as a reaction to the decrease in the heat absorption rate of the HT coolant at the outlet openings 18c. Thus, the margin ΔQw can be HT , which is generated by the reduction in the amount of heat absorbed by the HT refrigerant, the cooling capacity Qw LT of the NT cooling circuit 34 are appropriately assigned.

[0072] In the response improvement process of the first embodiment, the ignition timing is adjusted in response to the increase in the flow rate V. LTThe ignition timing is advanced by reducing the intake air temperature (i.e., by advancing the LT coolant). This allows the increased combustion engine torque due to the ignition advance to be added to the increased combustion engine torque due to the increased intake air volume along with the increased boost pressure. Consequently, acceleration performance can be further improved. If the ignition timing is advanced while only the intake air temperature is reduced, the exhaust gas temperature (exhaust gas energy) decreases due to the advance of the combustion center point. According to the response improvement process, this decrease in exhaust gas energy is mitigated by reducing the coolant flow around the exhaust ports 18c. Therefore, more exhaust gas energy can be supplied to the turbine 12b while the ignition timing is advanced along with the reduction in intake air temperature. This allows acceleration performance to be improved more effectively.

[0073] Next, modified examples of the first embodiment are described. In the first embodiment, the increase amount ΔV LT The LT flow rate VLT is calculated such that the cooling capacity Qw LT the NT cooling circuit 34 is increased by the amount corresponding to the decrease in cooling capacity Qw HT of the HT cooling circuit 32 corresponds to (margin ΔQw HT ). Instead of this calculation example, the increase amount ΔV can be used. LT the NT flow rate V LT in response to the decrease in the HT flow rate V HTex For example, it could be a predetermined fixed value. This also applies when using the simply determined increase amount ΔV. LT At least part of the margin ΔQwHT generated by reducing the heat absorption quantity of the HT coolant can be used in the NT cooling circuit 34.

[0074] In the response improvement process of the first embodiment, the ignition timing is adjusted in response to the increase in the LT flow rate V. LT brought forward.

[0075] The response improvement process can also be performed without advancing the ignition timing.

[0076] In the response improvement process of the first embodiment, the flow rate control valve 58 is closed to stop the flow of the HT coolant in the first coolant channel 54 (i.e., the HT flow rate V). HTex is zero). In a response improvement process according to a second embodiment, the HT flow rate V HTex The LT flow rate V is variable during acceleration, depending on the operating state of the turbocharged combustion engine. LT The LT pump 62 is controlled in such a way that it increases when the quantity of HT flow rate V is reduced. HTex increases.

[0077] Fig. Figure 10 is a flowchart showing an example of the response improvement process during acceleration according to the second embodiment. The process in this flowchart is similar to the process in Figure 10. Fig. 3 flowchart shown, with the exception that steps S108 and S110 are replaced by steps S200 and S202.

[0078] If the combustion engine coolant temperature is equal to or lower than the determined value TH in step S106, the process continues in Fig. 10 continues with step S200. In step S200, the ECU 70 determines a reduced high-temperature flow rate V. HTex A and controls the flow rate adjustment valve 58 to reduce the HT flow rate V HTex To reach A.

[0079] The reduced HT flow rate V HTex A is changed depending on the operating state of the combustion engine 10. In particular, the HT flow rate V is HTexA was modified to ensure the reliability of the exhaust system of the internal combustion engine 10. For example, the HT flow rate V is HTex A is determined (calculated) to decrease when the combustion engine coolant temperature (HT coolant temperature) decreases at time t1, when the acceleration period TACC has begun. More precisely, in the range of the combustion engine coolant temperature that is equal to or lower than the determined value TH, the HT flow rate V is reduced. HTex A is determined (calculated) so that it decreases with decreasing combustion engine coolant temperature and reaches zero when the combustion engine coolant temperature is equal to or lower than a certain value.

[0080] In step S202, which follows step S200, the ECU 70 calculates an increase amount ΔV. LT the LT flow rate V LT based on the reduced HT flow rate V HTexA. An example of a procedure for calculating the increase amount ΔV LT is identical to the example in step S 110 with reference to Fig. 4 to Fig. 7. According to this calculation method, the increase amount ΔV LT calculated so that it increases when the decrease in the HT flow rate V HTex in the process of step S200 increases. According to this calculation method, the increase amount ΔV LT calculated to determine the cooling capacity Qw LT to increase the NT cooling circuit 34 by an amount that corresponds to a decrease in cooling capacity Qw HT of the HT cooler 38 in response to a decrease in the heat absorption quantity of the HT coolant together with the selection of the HT flow rate V HTex A corresponds to.

[0081] In step S202, the ECU 70 controls the LT pump 62 to increase the calculated amount ΔV by the calculated increase. LT increased LT flow rate V LT to reach.

[0082] In the response improvement process of the second embodiment, the acceleration behavior can be improved similarly to the first embodiment. In the first embodiment, the coolant flow around the outlet openings 18c is uniformly stopped when the combustion engine coolant temperature is equal to or lower than the set value TH. According to the second embodiment, in which the HT flow rate V HTexSince the response improvement process is variable during execution (e.g., gradually reduced depending on the combustion engine coolant temperature) to account for the reliability of the exhaust system, the determined value TH for use in step S106 can be set higher than in the first embodiment. In other words, the operating condition for executing the response improvement process (e.g., the combustion engine coolant temperature range) can be extended compared to the first embodiment.

[0083] In the second embodiment, the increase amount ΔV LT the LT flow rate V LT calculated to determine the cooling capacity Qw LT to increase the NT cooling circuit 34 by the amount corresponding to the decrease in cooling capacity Qw HT of the HT cooling circuit 32 (margin ΔQw HT ) together with or corresponding to the decrease in the HT flow rate V HTexThis corresponds to the following calculation example. Instead of this example, the increase amount ΔV can be used. LT even without calculating the margin ΔQw HT so that it is calculated such that it decreases with increasing decrease of the HT flow rate V HTex rises.

Claims

[1] Cooling device (30) for a turbocharged internal combustion engine (10), wherein the turbocharged internal combustion engine (10) comprises: a cylinder head (18) with an exhaust port (18C); a turbocharger (12) comprising a compressor (12a) arranged in an inlet channel (22) and a turbine (12b) arranged on a downstream side of the outlet opening (18C) in an outlet channel (24) which includes a channel in the outlet opening (18C); and a charge air cooler (26) which is arranged on a downstream side of the compressor (12a) in the inlet channel (22), the cooling device (30) comprises: a high-temperature side cooling circuit (32) comprising a high-temperature side pump (36) configured to circulate a high-temperature coolant, and an HT cooler (38) acting as a high-temperature side cooling section, configured to cool the high-temperature coolant, wherein the high-temperature side cooling circuit (32) is configured to supply the high-temperature coolant to the cylinder head (18); a low-temperature side cooling circuit (34) comprising a low-temperature side pump (62) configured to circulate a low-temperature coolant, and an LT cooler (64) acting as a low-temperature side cooling section, configured to cool the low-temperature coolant, wherein the low-temperature side cooling circuit (34) is configured to supply the low-temperature coolant to the charge air cooler (26); and an electronic control unit (70), where the high-temperature cooling section and the low-temperature cooling section are at least partially used together, comprising the high-temperature cooling circuit (32), a first coolant channel (54) in which the high-temperature coolant flows around the outlet opening (18C), a second coolant channel (56) in which the high-temperature coolant flows through the cylinder head (18) without flowing around the exhaust port (18C), and a flow rate control valve (58) configured to control the flow rate of the high-temperature coolant flowing through the first coolant channel (54), and wherein the electronic control unit (70) is configured to perform a response improvement process for controlling the flow rate control valve (58) in at least part of an acceleration period from the start of acceleration of a vehicle containing the turbocharged internal combustion engine (10) to the end of acceleration, in order to reduce the flow rate of the high-temperature coolant flowing through the first coolant channel (54), characterized by , that the electronic control unit (70) is configured to control the low-temperature side pump (62) to increase the flow rate of the low-temperature coolant circulating through the low-temperature side cooling circuit (34), wherein the electronic control unit (70) is configured to control the flow rate control valve (58) during the response improvement process to stop the flow of high-temperature coolant through the first coolant channel (54), and wherein the electronic control unit (70) is configured to control the low-temperature side pump (62) during the response improvement process by increasing the flow rate of the low-temperature coolant in order to increase the cooling capacity of the low-temperature side cooling circuit (34) by an amount corresponding to a decrease in the cooling capacity of the high-temperature side cooling circuit (32) in response to a decrease in the amount of heat absorbed by the high-temperature coolant from the exhaust gas via the outlet opening (18C). [2] Cooling device (30) for a turbocharged internal combustion engine (10), wherein the turbocharged internal combustion engine (10) comprises: a cylinder head (18) with an exhaust port (18C); a turbocharger (12) comprising a compressor (12a) arranged in an inlet channel (22) and a turbine (12b) arranged on a downstream side of the outlet opening (18C) in an outlet channel (24) which includes a channel in the outlet opening (18C); and a charge air cooler (26) which is arranged on a downstream side of the compressor (12a) in the inlet channel (22), the cooling device (30) comprises: a high-temperature side cooling circuit (32) comprising a high-temperature side pump (36) configured to circulate a high-temperature coolant, and an HT cooler (38) acting as a high-temperature side cooling section, configured to cool the high-temperature coolant, wherein the high-temperature side cooling circuit (32) is configured to supply the high-temperature coolant to the cylinder head (18); a low-temperature side cooling circuit (34) comprising a low-temperature side pump (62) configured to circulate a low-temperature coolant, and an LT cooler (68) acting as a low-temperature side cooling section, configured to cool the low-temperature coolant, wherein the low-temperature side cooling circuit (34) is configured to supply the low-temperature coolant to the charge air cooler (26); and an electronic control unit (70), where the high-temperature cooling section and the low-temperature cooling section are at least partially used together, comprising the high-temperature cooling circuit (32), a first coolant channel (54) in which the high-temperature coolant flows around the outlet opening (18C), a second coolant channel (56) in which the high-temperature coolant flows through the cylinder head (18) without flowing around the exhaust port (18C), and a flow rate control valve (58) configured to control the flow rate of the high-temperature coolant flowing through the first coolant channel (54), and wherein the electronic control unit (70) is configured to perform a response improvement process for controlling the flow rate control valve (58) in at least part of an acceleration period from the start of acceleration of a vehicle containing the turbocharged internal combustion engine (10) to the end of acceleration, in order to reduce the flow rate of the high-temperature coolant flowing through the first coolant channel (54), characterized by , that the electronic control unit (70) is configured to control the low-temperature side pump (62) to increase the flow rate of the low-temperature coolant circulating through the low-temperature side cooling circuit (34), wherein the electronic control unit (70) is configured to control the low-temperature side pump (62) during the response improvement process by increasing the flow rate of the low-temperature coolant when a decrease in the flow rate of the high-temperature coolant flowing through the first coolant channel (54) increases, and wherein the electronic control unit (70) is configured to control the low-temperature side pump (62) during the response improvement process by increasing the flow rate of the low-temperature coolant in order to increase the cooling capacity of the low-temperature side cooling circuit (34) by an amount corresponding to a decrease in the cooling capacity of the high-temperature side cooling circuit (32) in response to a decrease in the amount of heat absorbed by the high-temperature coolant from the exhaust gas via the outlet opening (18C). [3] Cooling device (30) according to claim 1 or 2, wherein: the turbocharged internal combustion engine (10) further comprises an ignition device (76); and the electronic control unit (70) is configured to control the ignition device (76) during the response improvement process in such a way as to advance an ignition timing in response to an increase in the flow rate of the low temperature coolant.

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