JP2018021459A - Cooling system and device for controlling the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cooling system capable of avoiding boiling of cooling water while extending a stop period of a water pump as much as possible during starting of an internal combustion engine.SOLUTION: A cooling system 2 includes a water pump 11, an outflow restraining section 12 for restraining outflow of cooling water in an internal combustion engine 10 to the water pump 11 side, and a flow rate adjusting section 17 for adjusting a flow rate of the cooling water flowing out of the internal combustion engine 10. In the cooling system 2, the water pump 11 and the flow rate adjusting section 17 are driven to increase a pressure of the cooling water in the inside of the internal combustion engine 10, and thus, water pressure increase control is executed.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a cooling system for cooling an internal combustion engine and a control device for the cooling system.

  A cooling water passage is provided in a cylinder head and a cylinder block of the internal combustion engine, and the cooling water is pumped to the cooling water passage by an electric water pump to warm up or cool the internal combustion engine (for example, see Patent Document 1 below). .

  In such a cooling apparatus for an internal combustion engine using an electric water pump, the water pump is stopped when the temperature of the cooling water is low as in the warm-up operation. When the water pump is stopped, the circulation of the cooling water is stopped, so that the cooling effect by the cooling water is suppressed and warming up of the internal combustion engine is promoted. Thereafter, when the coolant temperature rises, the water pump is driven at a timing at which the internal combustion engine is not overheated. When the water pump is driven, the circulation of the cooling water is started, and the cooling effect by the cooling water is exhibited.

International Publication No. 2012/176292

  From the viewpoint of promoting warm-up of the internal combustion engine, it is desirable to make the stop period of the water pump as long as possible. However, if the stop period of the water pump is too long, the possibility that the cooling water will boil increases. If the cooling water boils, the gasket part and the seal part of the internal combustion engine may be damaged. Therefore, driving of the water pump has to be started at a temperature at which the cooling water does not boil, and there is room for improvement from the viewpoint of promoting warm-up and accompanying fuel consumption improvement.

  The present invention has been made in view of such problems, and an object of the present invention is to provide a cooling system capable of avoiding boiling of cooling water while making the stop period of the water pump as long as possible when starting the internal combustion engine. It is to provide the control device.

  In order to solve the above-described problems, a cooling system according to the present invention is a cooling system for cooling an internal combustion engine, and a cooling water passage (50, 51, 52, 53) for circulating cooling water to the internal combustion engine (10). , 54, 55, 56, 57, 58, 59), a water pump (11) provided in the cooling water passage (50, 59), and the cooling water passage (50) on the discharge side of the water pump. And an outflow suppression portion (12) that is provided upstream of the internal combustion engine and prevents the cooling water in the internal combustion engine from flowing out to the water pump side, and the internal combustion engine in the cooling water passage (52). A flow rate adjusting unit (17) that is provided on the downstream side of the engine and adjusts the flow rate of the cooling water flowing out from the internal combustion engine; and the pressure of the cooling water inside the internal combustion engine is increased. Serial water pump includes the flow rate adjusting unit, and warm-up control unit for executing pressure increase control by driving at least one of the outflow inhibition portion (304), the.

  According to the present invention, the coolant is prevented from flowing from the internal combustion engine to the flow rate adjuster by driving the flow rate adjuster, and the coolant is driven into the internal combustion engine by driving the water pump. The pressure of the cooling water inside can be increased. Furthermore, since the outflow suppression portion is provided between the discharge side of the water pump and the internal combustion engine, it is possible to suppress the cooling water sent to the internal combustion engine from returning to the water pump side. Since the state where the pressure of the cooling water in the internal combustion engine is increased can be maintained, the boiling point of the cooling water can be increased and the boiling of the cooling water can be avoided. Thereby, the time for stopping the circulation of the cooling water can be lengthened and the cooling water can be controlled in a high temperature state, so that the warm-up time can be shortened.

  In order to solve the above problems, a control device according to the present invention is a control device for a cooling system that cools an internal combustion engine, and includes a warm-up control unit (304). The cooling system to be controlled includes the water pump (11) provided in a cooling water passage for circulating cooling water to the internal combustion engine (10), and the internal combustion engine in the cooling water passage on the discharge side of the water pump. An outflow suppression portion (12) that is provided upstream of the engine and suppresses cooling water in the internal combustion engine from flowing out to the water pump; and provided downstream of the internal combustion engine in the cooling water passage. And a flow rate adjusting unit (17) for adjusting the flow rate of the cooling water flowing out from the internal combustion engine. The warm-up control unit performs water pressure increase control by driving at least one of the water pump, the flow rate adjustment unit, and the outflow suppression unit so that the pressure of the cooling water inside the internal combustion engine increases. To do.

  Reference numerals in parentheses described in “Means for Solving the Problems” and “Claims” indicate a correspondence relationship with “Mode for Carrying Out the Invention” described later, It does not indicate that the invention described in “Means for Solving the Problems” and “Claims” is limited to “Mode for Carrying Out the Invention” described later.

  ADVANTAGE OF THE INVENTION According to this invention, the cooling system which can avoid the boiling of cooling water, and its control apparatus can be provided, making the stop period of a water pump long as much as possible at the time of start-up of an internal combustion engine.

FIG. 1 is a system configuration diagram showing the configuration of the cooling system according to the first embodiment of the present invention. FIG. 2 is a block diagram for illustrating a functional configuration of the ECU shown in FIG. FIG. 3 is a flowchart for explaining the warm-up determination process. FIG. 4 is a flowchart for explaining the warm-up control process. FIG. 5 is a diagram for explaining fluctuations in water temperature and water pressure when the process shown in FIG. 4 is executed. FIG. 6 is a diagram for explaining the relationship between the boiling point and the water pressure. FIG. 7 is a diagram for explaining the content of the step of calculating the maximum temperature in FIG. FIG. 8 is a system configuration diagram illustrating a configuration of a cooling system according to a comparative example. FIG. 9 is a diagram for explaining the effect of the first embodiment with respect to the comparative example. FIG. 10 is a diagram for explaining the fuel efficiency improvement effect. FIG. 11 is a flowchart for explaining processing when there is a throttle warm-up request. FIG. 12 is a system configuration diagram showing the configuration of the cooling system according to the second embodiment of the present invention. FIG. 13 is a system configuration diagram showing the configuration of the cooling system according to the third embodiment of the present invention. FIG. 14 is a diagram illustrating a relationship between driving of the water pump and water pressure. FIG. 15 is a system configuration diagram showing the configuration of the cooling system according to the fourth embodiment of the present invention. FIG. 16 is a diagram for explaining fluctuations in water temperature and water pressure in the fourth embodiment.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In order to facilitate the understanding of the description, the same constituent elements in the drawings will be denoted by the same reference numerals as much as possible, and redundant description will be omitted.

  As shown in FIG. 1, the cooling system 2 according to the first embodiment of the present invention includes an internal combustion engine 10, a water pump 11, a check valve 12, a thermostat 13, a radiator 14, a heater core 15, A throttle 16, a multi-way valve 17, and an ECU (Electronic Control Unit) 30 are provided.

  The internal combustion engine 10 has a cylinder head 101 and a cylinder block 102. The cylinder head 101 is provided with a combustion chamber (not shown) for burning fuel. The cylinder block 102 is provided with a piston (not shown) and a crankshaft (not shown).

  The internal combustion engine 10 is further provided with a cooling water passage 51 through which cooling water for cooling the cylinder head 101 and the cylinder block 102 is passed. The cooling water passage 51 is provided so as to introduce cooling water from the cylinder block 102 side and discharge the cooling water from the cylinder head 101 side.

  A water pressure sensor 18 and a water temperature sensor 19 are provided at the downstream end of the cooling water passage 51. The water pressure sensor 18 is a sensor that detects the water pressure of the cooling water in the cooling water passage 50. The water pressure sensor 18 outputs an electric signal indicating the water pressure to the ECU 30.

  The water temperature sensor 19 is a sensor that detects the temperature of the cooling water in the cooling water passage 50. The water temperature sensor 19 is provided in the most downstream portion of the cooling water passage 50 in the cylinder head 101. In the cylinder head 101, since the center part of the part in which the combustion chamber is provided is the highest temperature, the water temperature measured by the water temperature sensor 19 is the temperature of the low temperature part compared to the maximum temperature part. The water temperature sensor 19 outputs an electrical signal indicating the water temperature to the ECU 30.

  The downstream end of the cooling water passage 50 is connected to the upstream end of the cooling water passage 51. Since the upstream side of the cooling water passage 51 is provided in the cylinder block 102, the cooling water passage 50 is connected to the downstream end of the cooling water passage 51 in the cylinder block 102.

  The upstream end of the cooling water passage 50 is connected to the discharge port side of the water pump 11. Cooling water that is driven and discharged under pressure by the water pump 11 is sent to the internal combustion engine 10 through the cooling water passage 50.

  A check valve 12 is provided in the cooling water passage 50. The check valve 12 passes the cooling water discharged from the water pump 11 to the internal combustion engine 10 side. The check valve 12 acts so that the cooling water does not flow backward from the internal combustion engine 10 even when the driving of the water pump 11 is stopped.

  The water pump 11 is an electric pump. The water pump 11 is rotationally driven according to a drive signal output from the ECU 30. When the water pump 11 is driven to rotate, the cooling water is discharged to the cooling water passage 50 side.

  The downstream end of the cooling water passage 51 is connected to the upstream end of the cooling water passage 52. Since the downstream side of the cooling water passage 51 is provided in the cylinder head 101, the cooling water passage 50 is connected to the upstream end of the cooling water passage 52 in the cylinder head 101.

  The downstream end of the cooling water passage 52 is connected to the multi-way valve 17. The multi-way valve 17 is also connected to the upstream end of the cooling water passage 53, the upstream end of the cooling water passage 54, and the upstream end of the cooling water passage 56.

  The multi-way valve 17 is a valve that stops the cooling water flowing from the cooling water passage 52 or diverts the cooling water flowing from the cooling water passage 52 to the cooling water passages 53, 54, and 56. The multi-way valve 17 is driven according to a drive signal output from the ECU 30.

  The downstream end of the cooling water passage 53 is connected to the throttle 16. An upstream end of the cooling water passage 55 is connected to the throttle 16. The cooling water flowing into the throttle 16 from the cooling water passage 53 flows through the throttle 16 and flows out into the cooling water passage 55. Since the cooling water flowing out from the internal combustion engine 10 is hot, the throttle 16 is heated by flowing through the throttle 16. Therefore, freezing of the throttle 16 is avoided.

  The cooling water passage 55 is connected to the downstream end of the cooling water passage 54. The downstream end of the cooling water passage 55 is connected to the heater core 15. The upstream end of the cooling water passage 57 is connected to the heater core 15. The cooling water flowing into the heater core 15 from the cooling water passage 55 flows through the heater core 15 and flows out into the cooling water passage 57. Since the cooling water flowing out from the internal combustion engine 10 is hot, heat is exchanged with the conditioned air in the heater core 15 to heat the conditioned air. The cooling water that has flowed through the heater core 15 flows out into the cooling water passage 57 in a state where the temperature is lowered.

  The downstream end of the cooling water passage 56 is connected to the radiator 14. The upstream end of the cooling water passage 58 is connected to the radiator 14. The cooling water that flows into the radiator 14 from the cooling water passage 56 flows through the radiator 14 and flows out to the cooling water passage 58. Since the cooling water flowing out from the internal combustion engine 10 is hot, the radiator 14 exchanges heat with the outside air, and the temperature decreases. The cooling water that has flowed through the radiator 14 flows out into the cooling water passage 58 in a state where the temperature is lowered.

  The downstream end of the cooling water passage 57 and the downstream end of the cooling water passage 58 are connected to the thermostat 13. An upstream end of the cooling water passage 59 is connected to the thermostat 13. When the temperature of the cooling water flowing into the thermostat 13 from the cooling water passages 57 and 58 is equal to or lower than the threshold temperature, the thermostat 13 is closed and the cooling water is stopped. When the temperature of the cooling water flowing into the thermostat 13 from the cooling water passages 57 and 58 exceeds the threshold temperature, the thermostat 13 is opened and the cooling water flows out to the cooling water passage 59. The downstream end of the cooling water passage 59 is connected to the water pump 11.

  Next, the ECU 30 that is a control device used in the cooling system 2 will be described with reference to FIG. The ECU 30 receives a water pressure detection signal output from the water pressure sensor 18 and a water temperature detection signal output from the water temperature sensor 19. The ECU 40 outputs drive signals to the water pump 11 and the multi-way valve 17.

  The ECU 30 includes a water temperature acquisition unit 301, a water pressure acquisition unit 302, a warm-up determination unit 303, a warm-up control unit 304, and a maximum temperature acquisition unit 305 as functional components.

  The water temperature acquisition unit 301 is a part that acquires the water temperature of the cooling water inside the internal combustion engine 10. The water temperature acquisition unit 301 acquires the coolant temperature based on the water temperature detection signal output from the water temperature sensor 19. In the case of the present embodiment, it is used as a water temperature detection signal output from the water temperature sensor 19 provided inside the internal combustion engine 10, but the cooling water inside the internal combustion engine 10 from the output result of the water temperature sensor provided outside the internal combustion engine 10. The water temperature may be estimated.

  The water pressure acquisition unit 302 is a part that acquires the water pressure of the cooling water inside the internal combustion engine 10. The water pressure acquisition unit 302 acquires the water pressure of the cooling water based on the water pressure detection signal output from the water pressure sensor 18. In the case of the present embodiment, it is used as a water pressure detection signal output from the water pressure sensor 18 provided inside the internal combustion engine 10, but the cooling water inside the internal combustion engine 10 from the output result of the water pressure sensor provided outside the internal combustion engine 10. The water pressure may be estimated. Further, the cooling water pressure in the internal combustion engine 10 may be estimated from the driving conditions of the water pump 11 and the multi-way valve 17 regardless of the output result of the water pressure sensor.

  The warm-up determination unit 303 is a part that determines the warm-up state of the internal combustion engine 10. The warm-up determination unit 303 determines whether the internal combustion engine 10 has been warmed up based on the coolant temperature acquired by the water temperature acquisition unit 301.

  The warm-up control unit 304 is a part that executes water pressure increase control by driving at least one of the water pump 11 and the multi-way valve 17 so that the pressure of the cooling water in the internal combustion engine 10 increases. The warm-up control unit 304 controls the water pressure increase by driving the water pump 11 and feeding the cooling water into the internal combustion engine 10 while driving the multi-way valve 17 to suppress the flow rate of the cooling water flowing out from the internal combustion engine 10. Run.

  The maximum temperature acquisition unit 305 is a part that acquires the maximum temperature of the cooling water inside the internal combustion engine 10. A specific mode in which the maximum temperature acquisition unit 305 acquires the maximum temperature of the cooling water will be described later.

  Next, the operation of the cooling system 2 will be described with reference to FIG. In step S <b> 101, the water temperature acquisition unit 301 detects a water temperature sensor temperature T detected by the water temperature sensor 19.

  In step S102 following step S101, the warm-up determination unit 303 determines whether or not the water temperature sensor temperature T has reached the warm-up temperature Th. If the water temperature sensor temperature T has not reached the warm-up temperature Th (step S102: YES), the process proceeds to step S103. If the water temperature sensor temperature T has reached the warm-up temperature Th (step S102: NO), the process is terminated.

  In step S103, warm-up control is executed. The warm-up control will be described in detail with reference to FIG. 4, FIG. 5, FIG. 6, and FIG. FIG. 4 is a flowchart showing the warm-up control. FIG. 5 is a diagram showing the behavior, water pressure, and temperature of each part when the warm-up control is performed. FIG. 5A shows the operation and stop of the water pump 11. FIG. 5B shows the opening degree of the multi-way valve 17. FIG. 6 shows a water vapor pressure diagram. FIG. 7 shows the relationship between the maximum temperature of the cooling water in the internal combustion engine 10 and the integrated flow rate of the water pump 11.

  In step S201 of FIG. 4, the warm-up control unit 304 outputs a drive signal to the multi-way valve 17, and fully closes the multi-way valve 17 in all directions. In step S202 following step S201, the water pressure acquisition unit 302 detects the water pressure sensor pressure P detected by the water pressure sensor 18.

  In step S203 following step S202, the warm-up determination unit 303 determines whether or not the water pressure sensor pressure P has reached the target water pressure P1 during warm-up. If the water pressure sensor pressure P has not reached the target water pressure P1 (step S203: YES), the process proceeds to step S207. If the water pressure sensor pressure P has reached the target water pressure P1 (step S203: NO), the process proceeds to step S204.

  In step S207, the warm-up control unit 304 drives the water pump 11. When the process of step S207 ends, the process returns to step S202. In FIG. 5, this corresponds to the behavior between time t2 and time t3.

  In step S204, the warm-up control unit 304 stops the water pump 11. The processing from step S202 to step S204 corresponds to the period from time t1 to time t3 in FIG.

  In step S205 following step S204, the water temperature acquisition unit 301 detects the water temperature sensor temperature T detected by the water temperature sensor 19.

  In step S206 following step S205, the warm-up determination unit 303 determines whether or not the water temperature sensor temperature T has reached the warm-up temperature Th. If the water temperature sensor temperature T has not reached the warm-up temperature Th (step S206: YES), the process returns to step S202. If the water temperature sensor temperature T has reached the warm-up temperature Th (step S206: NO), the process proceeds to step S208.

  In step S <b> 208, the maximum temperature acquisition unit 305 acquires the maximum temperature Tmax of the cooling water inside the internal combustion engine 10. As shown in FIG. 7, there is a correlation between the maximum temperature Tmax−water temperature sensor temperature T and the integrated flow rate of the water pump 11, and mapping is performed. The integrated flow rate of the water pump 11 can be calculated from the drive time of the water pump 11. Maximum temperature acquisition unit 305 calculates maximum temperature Tmax according to this map. As shown in FIG. 5, Tmax changes at a temperature higher than T.

  In step S209 following step S208, the warm-up determination unit 303 calculates the boiling point Tv from the water pressure sensor pressure P. As shown in FIG. 6, the boiling point Tv can be calculated from the water vapor pressure diagram. For example, when the water pressure sensor pressure P is 200 kPa in absolute pressure, the boiling point is 120 ° C. When the water pressure sensor pressure P is 300 kPa in absolute pressure, the boiling point is 133 ° C. When the water pressure sensor pressure P is 400 kPa in absolute pressure, the boiling point is 143 ° C.

  In step S210 following step S209, the warm-up determination unit 303 determines whether or not the maximum temperature Tmax is lower than the boiling point Tv-5 ° C. 5 ° C. is a margin value when comparing the maximum temperature Tmax and the boiling point Tv.

  When the maximum temperature Tmax is lower than the boiling point Tv−5 ° C. (step S210: NO), the process proceeds to step S213. When the maximum temperature Tmax is higher than the boiling point Tv−5 ° C. (step S210: YES), the process proceeds to step S211.

  In step S213, the warm-up control unit 304 performs control so that the water pump 11 is stopped and the opening degree of the multi-way valve 17 is maintained. In step S <b> 211, the warm-up control unit 304 controls the water pump 11 to be driven so that the opening degree of the multi-way valve 17 is increased. By doing in this way, a pressure can be dropped in steps according to the fall of maximum temperature Tmax, and boiling of cooling water can be avoided. In FIG. 5, this corresponds to the period between time t3 and time t4.

  In step S212 following step S211, the warm-up determination unit 303 determines whether or not the water pressure sensor pressure P has decreased to the post-warm-up water pressure P2. If the water pressure sensor pressure P has not decreased to the water pressure P2 after warming up (step S212: YES), the process returns to step S208. If the water pressure sensor pressure P has decreased to the water pressure P2 after warming up (step S212: NO), the process ends.

  Next, a cooling system 2X as a comparative example will be described with reference to FIG. The cooling system 2 </ b> X is obtained by removing the check valve 12 and the multi-way valve 17 from the cooling system 2. The water pressure sensor 18 is provided in the cooling water passage 50.

  As shown in FIG. 9, in the cooling system 2 of the present embodiment, the water pump 11 is driven from time t2 to time t3 and the multi-way valve 17 is fully closed, so that the water stop time can be extended. ing. On the other hand, in the cooling system 2X of the comparative example, the water pump 11 is driven from time t2, and the water stop time is shortened.

  As shown in FIG. 10, the fuel efficiency improves as the cooling water circulation start water temperature increases. If the water stop time is long, the cooling water circulates after the temperature rises, so that fuel efficiency is improved. In particular, in the cooling system 2 of this embodiment, since the water pressure increase control is executed, the boiling point of the cooling water rises, the temperature of the cooling water is raised without boiling, and the high water temperature control region is expanded. While the cooling system 2 is warmed up at time t3, the cooling system 2X requires time t4, so the warm-up time can be shortened.

  Next, the warm-up determination control when there is a throttle warm-up request will be described with reference to FIG. In step S301, the water temperature acquisition unit 301 detects the water temperature sensor temperature T detected by the water temperature sensor 19.

  In step S302 following step S301, the warm-up determination unit 303 determines whether or not the water temperature sensor temperature T has reached the warm-up temperature Th. If the water temperature sensor temperature T has not reached the warm-up temperature Th (step S302: YES), the process proceeds to step S303. If the water temperature sensor temperature T has reached the warm-up temperature Th (step S302: NO), the process is terminated.

  In step S303, the warm-up determination unit 303 determines whether or not the water temperature sensor temperature T has reached the throttle warm-up temperature Tc. If the water temperature sensor temperature T has not reached the throttle warm-up temperature Tc (step S303: YES), the process proceeds to step S304. If the water temperature sensor temperature T has reached the throttle warm-up temperature Tc (step S303: NO), the process proceeds to step S305.

  In step S <b> 304, the warm-up control unit 304 opens the multi-way valve 17 on the side of the cooling water passage 53, which is a throttle flow path, and executes control for driving the water pump 11. As a result, high-temperature cooling water flowing out from the internal combustion engine 10 can be supplied to the throttle 16.

  In step S <b> 305, the warm-up control unit 304 performs control to close the multi-way valve 17 and stop the water pump 11. In step S306 following step S305, warm-up control is executed. The warm-up control is the same as that described with reference to FIGS. 4, 5, 6, and 7, and thus description thereof is omitted.

  As described above, the cooling system 2 according to the first embodiment cools the internal combustion engine 10, and the cooling water passages 50, 51, 52, 53, 54, 55 for circulating the cooling water to the internal combustion engine 10 are provided. 56, 57, 58, 59, the water pump 11 provided in the cooling water passages 50, 59, and the cooling water passage 50 on the discharge side of the water pump 11, provided upstream of the internal combustion engine 10, A check valve 12 that functions as an outflow suppression unit that suppresses cooling water in the engine 10 from flowing out toward the water pump 11, and a cooling water passage 52 that is provided downstream of the internal combustion engine 10. A multi-way valve 17 that functions as a flow rate adjusting unit that adjusts the flow rate of the flowing out cooling water, and a water pump so that the pressure of the cooling water in the internal combustion engine 10 is increased. It includes a warm-up control unit 304 to perform pressure increase control by driving the first and multiposition valve 17, the.

  According to this embodiment, the multi-way valve 17 is driven to prevent the cooling water from flowing out from the internal combustion engine 10 to the multi-way valve 17 side, and the water pump 11 is driven to feed the cooling water into the internal combustion engine 10. Thus, the pressure of the cooling water inside the internal combustion engine 10 can be increased. Further, since the check valve 12 is provided between the discharge side of the water pump 11 and the internal combustion engine 10, it is possible to suppress the cooling water sent to the internal combustion engine 10 from returning to the water pump 11 side. Therefore, since the state which raised the pressure of the cooling water in the internal combustion engine 10 can be maintained, the boiling point of the cooling water can be increased and the boiling of the cooling water can be avoided. Thereby, the time for stopping the circulation of the cooling water can be lengthened and the cooling water can be controlled in a high temperature state, so that the warm-up time can be shortened.

  When using an electromagnetic valve that functions as an outflow suppression unit instead of the check valve 12, the warm-up control unit 304 closes the electromagnetic valve that functions as an outflow suppression unit while stopping the circulation of the cooling water, When starting to circulate the cooling water, control for opening the valve can be executed.

  The cooling system 2 according to the present embodiment further includes a warm-up determination unit 303 that determines the warm-up state of the internal combustion engine 10. When the warm-up determination unit 303 determines that the internal combustion engine 10 is warming up, the warm-up control unit 304 drives the multi-way valve 17 that is an outflow suppression unit to flow out the cooling water flowing out from the internal combustion engine 10. Water pressure increase control is executed by driving the water pump 11 and feeding cooling water to the internal combustion engine 10 while suppressing the flow rate. When the warm-up determination unit 303 determines that the internal combustion engine 10 is warming up, the warm-up control unit 304 performs the water pressure increase control. The water pressure can be increased.

  The cooling system 2 according to the present embodiment further includes a water pressure acquisition unit 302 that acquires the pressure of the cooling water inside the internal combustion engine 10. The warm-up control unit 304 performs water pressure increase control until the acquired water pressure acquired by the water pressure acquiring unit 302 reaches the target water pressure. Since the water pressure acquisition unit 302 acquires the water pressure of the cooling water based on the water pressure detection signal output from the water pressure sensor 18, it is possible to grasp the changed water pressure even when the water pressure fluctuates inside the internal combustion engine 10. . The warm-up control unit 304 can execute water pressure increase control corresponding to the water pressure fluctuation.

  In the cooling system 2 according to the present embodiment, the warm-up control unit 304 resumes the water pressure increase control when the acquired water pressure becomes lower than the target water pressure after the acquired water pressure reaches the target water pressure and stops the water pressure increase control. . Since the water pressure inside the internal combustion engine 10 can be maintained so as to maintain the target water pressure, the boiling point of the cooling water can be increased corresponding to the increased water pressure.

  In the cooling system 2 according to the present embodiment, the warm-up control unit 304 is an outflow suppression unit when the acquired water pressure becomes higher than the target water pressure after the acquired water pressure reaches the target water pressure and stops the water pressure increase control. The flow rate of the cooling water flowing out from the internal combustion engine 10 can be increased by driving the multi-way valve 17. By adjusting the water pressure of the cooling water in this way, it is possible to avoid an excessive increase in the water pressure of the cooling water.

  The cooling system 2 according to the present embodiment further includes a water temperature acquisition unit 301 that acquires the temperature of the cooling water inside the internal combustion engine 10. The warm-up determination unit 303 determines that the internal combustion engine 10 is warming up until the acquired water temperature acquired by the water temperature acquisition unit 301 reaches the warm-up water temperature. Since the water temperature acquisition unit 301 acquires the coolant temperature based on the water temperature detection signal output from the water temperature sensor 19, the water temperature fluctuation can be accurately grasped.

  Further, in the cooling system 2 according to this embodiment, when the warm-up determination unit 303 determines that the internal combustion engine 10 has been warmed up, the warm-up control unit 304 drives the multi-way valve 17 that is an outflow suppression unit. Then, while increasing the flow rate of the cooling water flowing out from the internal combustion engine 10, the water pressure lowering control is executed by suppressing the driving of the water pump 11 and reducing the cooling water fed into the internal combustion engine 10. By executing the water pressure lowering control, it is possible to shift to the circulating state of the cooling water after the warm-up is completed.

  Further, in the cooling system 2 according to the present embodiment, the warm-up control unit 304 drives the multi-way valve 17 that is an outflow suppression unit stepwise to increase the flow rate of cooling water flowing out from the internal combustion engine 10, while Water pressure lowering control is executed by intermittently driving the pump 11 to reduce the cooling water fed into the internal combustion engine 10. Since the pressure of the cooling water can be lowered stepwise from the high pressure state, it is possible to shift to the cooling water circulation state after completion of warming up while avoiding boiling of the cooling water.

  The cooling system 2 according to this embodiment further includes a maximum temperature acquisition unit 305 that acquires the maximum temperature of the cooling water inside the internal combustion engine 10. The warm-up control unit 304 performs water pressure increase control so that the maximum temperature does not exceed the boiling point of the cooling water. Since the water pressure increase control is executed so that the maximum temperature of the cooling water inside the internal combustion engine 10 does not exceed the boiling point of the cooling water, the gasket can be prevented from being damaged anywhere in the internal combustion engine 10.

  In the cooling system 2 according to the present embodiment, when the warm-up determination unit 303 determines that the internal combustion engine 10 has been warmed up, the warm-up control unit 304 does not exceed the boiling point of the cooling water. As described above, the multi-way valve 17 that is the outflow suppression unit is driven to increase the flow rate of the cooling water flowing out from the internal combustion engine, and the water pressure is lowered by suppressing the driving of the water pump 11 and reducing the cooling water fed to the internal combustion engine. Execute control. Since the water pressure lowering control is executed so that the maximum temperature of the cooling water in the internal combustion engine 10 does not exceed the boiling point of the cooling water, the gasket can be prevented from being damaged at any location in the internal combustion engine 10.

  Further, in the cooling system 2 according to the present embodiment, the warm-up control unit 304 drives the multi-way valve 17 that is an outflow suppression unit stepwise so that the maximum temperature does not exceed the boiling point of the cooling water. The water pressure lowering control is executed by increasing the flow rate of the cooling water flowing out from the engine and reducing the cooling water fed to the internal combustion engine 10 by intermittently driving the water pump 11. Since the pressure of the cooling water can be lowered stepwise from the high pressure state, it is possible to shift to the cooling water circulation state after completion of warming up while avoiding boiling of the cooling water.

  In the cooling system 2 according to the present embodiment, the maximum temperature acquisition unit 305 calculates the maximum temperature based on the acquired water temperature and the flow rate integrated value of the cooling water. By using the map illustrated in FIG. 7, the maximum temperature can be acquired without arranging a water temperature sensor at a location where the maximum temperature is actually reached.

  In the cooling system 2 according to the present embodiment, as described with reference to FIG. 11, when the warm-up determination unit 303 determines that the internal combustion engine 10 is warming up and in a low temperature state, The warm-up control unit 304 drives the multi-way valve 17 that is an outflow suppression unit, and executes throttle warm-up control in which the cooling water flowing out from the internal combustion engine 10 flows through the cooling water passage 53 connected to the throttle 16. By performing the throttle warm-up control, the throttle 16 can be prevented from freezing.

  Next, the cooling system 2A according to the second embodiment will be described with reference to FIG. The cooling system 2A changes the arrangement position of the water pressure sensor 18 to the outside of the internal combustion engine 10 with respect to the cooling system 2. The water pressure sensor 18 is provided in the cooling water passage 50. Further, a temperature sensor 20 is additionally disposed at a portion where the maximum temperature is reached in the internal combustion engine 10. The temperature sensor 20 outputs a water temperature detection signal to the ECU 30.

  In the cooling system 2A according to the second embodiment, the maximum temperature acquisition unit 305 acquires the maximum temperature by detecting the water temperature of the portion where the temperature of the cooling water is highest in the internal combustion engine 10. Since the temperature sensor 20 detects the water temperature at the portion where the temperature of the cooling water is highest, the maximum temperature can be obtained more accurately. The cooling system 2A according to the second embodiment has the same effects as the cooling system 2 according to the first embodiment unless there is a technical contradiction.

  Next, a cooling system 2B according to the third embodiment will be described with reference to FIG. The cooling system 2B additionally includes a thermostat 21 with respect to the cooling system 2. A cooling water passage 51 </ b> B that branches from the cooling water passage 51 is provided inside the cylinder block 102. A thermostat 21 is provided at the downstream end of the cooling water passage 51. The upstream end of the cooling water passage 52B is further connected to the thermostat 21. The downstream end of the cooling water passage 52 </ b> B is connected to the cooling water passage 55. Thus, even if it is the structure by which the thermostat 21 was additionally arrange | positioned, unless there is technical contradiction, there exists an effect equivalent to the cooling system 2 which concerns on 1st Embodiment.

  By the way, even if it is the same drive time, the discharge flow rate of the water pump 11 changes depending on the water pressure condition in the internal combustion engine 10 because the pumping performance of the pump changes. As shown in FIG. 14 as an example, when the water pressure increases, the minimum driving time needs to be increased, and when the water pressure decreases, the minimum driving time relatively decreases. When the water pump 11 is driven in a situation where the water pressure decreases as in step S211 of FIG. 4, the driving time is controlled using the relationship between the water pressure and the minimum driving time as shown in FIG. It is preferable.

  As described above, when intermittently driving the water pump 11, the warm-up control unit 304 is based on the relationship between the minimum driving time in which the discharge flow rate of the water pump 11 becomes zero or more and the water pressure as illustrated in FIG. 14. Thus, the time for driving the water pump 11 can be corrected.

  Subsequently, a cooling system 2 </ b> C according to the fourth embodiment will be described with reference to FIGS. 15 and 16. With respect to the cooling system 2, the cooling system 2 </ b> C additionally includes a pressure regulating valve 22 as a differential pressure adjusting unit and a cooling water passage 60. The cooling water passage 60 is provided so as to connect the cooling water passage 52 and the cooling water passage 54. The pressure regulating valve 22 is provided in the cooling water passage 60. The pressure regulating valve 22 is configured so that the flow rate can be adjusted according to the differential pressure at the inlet / outlet of the multi-way valve 17 when the water temperature in the cylinder head 101 reaches the warm-up completion temperature of the internal combustion engine 10. . The pressure regulating valve 22 is controlled by the warm-up control unit 304.

  FIG. 16A shows the operation of the pressure regulating valve 22 as pressure regulating means. Until the warm-up is completed, the warm-up control unit 304 keeps the pressure regulating valve 22 closed, so that the pressure difference at the inlet / outlet of the multi-way valve 17 increases by the amount of operation of the water pump 11. When the warm-up of the internal combustion engine 10 is completed, the warm-up control unit 304 opens the pressure regulating valve 22 step by step so that the differential pressure at the inlet / outlet of the multi-way valve 17 gradually decreases.

  Thus, the pressure regulating valve 22 as a differential pressure adjusting unit that adjusts the differential pressure at the inlet / outlet of the multi-way valve 17 that is a flow rate adjusting unit can be further provided. When the warm-up determination unit 303 determines that the internal combustion engine 10 has been warmed up, the warm-up control unit 304 controls the pressure regulating valve 22 as a differential pressure adjustment unit, and the multi-way valve 17 as a flow rate adjustment unit. Water pressure lowering control can be executed to reduce the inlet / outlet differential pressure.

  The embodiments of the present invention have been described above with reference to specific examples. However, the present invention is not limited to these specific examples. Those in which those skilled in the art appropriately modify the design of these specific examples are also included in the scope of the present invention as long as they have the features of the present invention. Each element included in each of the specific examples described above and their arrangement, conditions, shape, and the like are not limited to those illustrated, and can be changed as appropriate. Each element included in each of the specific examples described above can be appropriately combined as long as no technical contradiction occurs.

2: Cooling system 10: Internal combustion engine 11: Water pump 12: Check valve 17: Multi-way valve 50, 51, 52, 53, 54, 55, 56, 57, 58, 59: Cooling water passage

Claims (17)

A cooling system for cooling an internal combustion engine,
Cooling water passages (50, 51, 52, 53, 54, 55, 56, 57, 58, 59) for circulating cooling water to the internal combustion engine (10);
A water pump (11) provided in the cooling water passage (50, 59);
In the cooling water passage (50) on the discharge side of the water pump, an outflow suppressing portion (suppressing the cooling water in the internal combustion engine from flowing out to the water pump side, provided upstream of the internal combustion engine) 12)
A flow rate adjusting unit (17) provided downstream of the internal combustion engine in the cooling water passage (52) and adjusting a flow rate of cooling water flowing out of the internal combustion engine;
A warm-up control unit (304) that performs water pressure increase control by driving at least one of the water pump, the flow rate adjustment unit, and the outflow suppression unit so that the pressure of the cooling water in the internal combustion engine increases. And a cooling system. The cooling system according to claim 1,
And a warm-up determination unit (303) for determining a warm-up state of the internal combustion engine,
When the warm-up determination unit determines that the internal combustion engine is warming up,
The warm-up control unit drives the outflow suppression unit to suppress the flow rate of the cooling water flowing out from the internal combustion engine, while driving the water pump to send the cooling water to the internal combustion engine, thereby increasing the water pressure. A cooling system that performs control. The cooling system according to claim 2,
Furthermore, a water pressure acquisition unit (302) for acquiring the pressure of the cooling water inside the internal combustion engine is provided,
The said warm-up control part is a cooling system which performs the said water pressure raise control until the acquisition water pressure which the said water pressure acquisition part acquires reaches a target water pressure. A cooling system according to claim 3,
The warming-up control unit, after the acquired water pressure reaches the target water pressure and stops the water pressure increase control, resumes the water pressure increase control when the acquired water pressure becomes lower than the target water pressure. A cooling system according to claim 3,
After the acquired water pressure reaches the target water pressure and stops the water pressure increase control, when the acquired water pressure becomes higher than the target water pressure, the warm-up control unit drives the outflow suppression unit to A cooling system that increases the flow rate of cooling water. The cooling system according to claim 2,
Furthermore, the water temperature acquisition part (301) which acquires the temperature of the cooling water in the said internal combustion engine is provided,
The cooling system, wherein the warm-up determination unit determines that the internal combustion engine is warming up until an acquired water temperature acquired by the water temperature acquisition unit reaches a warm-up water temperature. The cooling system according to claim 6,
When the warm-up determination unit determines that the internal combustion engine has been warmed up,
The warm-up control unit drives the outflow suppression unit to increase the flow rate of the cooling water flowing out from the internal combustion engine, while suppressing the driving of the water pump and reducing the cooling water fed to the internal combustion engine. Cooling system that performs water pressure drop control. A cooling system according to claim 7,
The warm-up control unit drives the outflow suppression unit stepwise to increase the flow rate of the cooling water flowing out from the internal combustion engine, and reduces the cooling water fed into the internal combustion engine by intermittently driving the water pump. Cooling system that performs water pressure drop control. 9. The cooling system according to claim 8, wherein
When the water pump is intermittently driven, the warm-up control unit corrects the time for driving the water pump based on the relationship between the minimum driving time when the discharge flow rate of the water pump is zero or more and the water pressure. , Cooling system. The cooling system according to claim 6,
Furthermore, a differential pressure adjusting unit (22) for adjusting the differential pressure at the inlet / outlet of the flow rate adjusting unit is provided,
When the warm-up determination unit determines that the internal combustion engine has been warmed up,
The warming-up control unit is a cooling system that controls the differential pressure adjusting unit to perform water pressure lowering control that reduces the differential pressure at the inlet / outlet of the flow rate adjusting unit. The cooling system according to claim 6,
And a maximum temperature acquisition unit (305) for acquiring the maximum temperature of the cooling water inside the internal combustion engine.
The warm-up control unit is a cooling system that executes the water pressure increase control so that the maximum temperature does not exceed the boiling point of the cooling water. A cooling system according to claim 11, comprising:
When the warm-up determination unit determines that the internal combustion engine has been warmed up,
The warm-up control unit drives the water pump while increasing the flow rate of the cooling water flowing out from the internal combustion engine by driving the outflow suppression unit so that the maximum temperature does not exceed the boiling point of the cooling water. A cooling system that executes water pressure lowering control by reducing cooling water that is suppressed and fed to the internal combustion engine. A cooling system according to claim 12, comprising:
The warm-up control unit increases the flow rate of the cooling water flowing out from the internal combustion engine by driving the outflow suppression unit stepwise so that the maximum temperature does not exceed the boiling point of the cooling water. A cooling system that performs water pressure lowering control by reducing the amount of cooling water that is intermittently driven and fed into the internal combustion engine. A cooling system according to any one of claims 11 to 13,
The maximum temperature acquisition unit is a cooling system that calculates a maximum temperature based on the acquired water temperature and a flow rate integrated value of cooling water. A cooling system according to any one of claims 11 to 13,
The said highest temperature acquisition part is a cooling system which acquires the highest temperature by detecting the water temperature of the part where the temperature of cooling water becomes the highest inside the said internal combustion engine. The cooling system according to claim 2,
When the warm-up determination unit determines that the internal combustion engine is warming up and is in a low temperature state,
The warm-up control unit drives the outflow suppression unit, and executes throttle warm-up control for flowing cooling water flowing out from the internal combustion engine to the cooling water passage (53) connected to the throttle (16).
Cooling system. A control device for a cooling system for cooling an internal combustion engine,
A warm-up controller (304),
The cooling system includes:
A water pump (11) provided in a cooling water passage (3) for circulating cooling water to the internal combustion engine (10);
An outflow suppression portion (12) that is provided upstream of the internal combustion engine in the cooling water passage on the discharge side of the water pump and suppresses cooling water in the internal combustion engine from flowing out to the water pump side; ,
A flow rate adjusting unit (17) that is provided on the downstream side of the internal combustion engine in the cooling water passage and adjusts the flow rate of the cooling water flowing out from the internal combustion engine,
The warm-up control unit performs water pressure increase control by driving at least one of the water pump, the flow rate adjustment unit, and the outflow suppression unit so that the pressure of the cooling water inside the internal combustion engine increases. Control device.

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