JP2014114739A - Cooling device of engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cooling device of an engine capable of achieving early warming-up of a cylinder block and shortening of an in-vehicle heating preparation time in warming-up of the engine, and preventing a temperature of the cylinder block from excessively lowering while securing heating performance in using in-vehicle heating.SOLUTION: An ECU 60 for controlling an operation of a cooling device 1 of an engine completely closes a radiator flow rate control valve 22, and drives a second cooling water pump 32 according to a heating request state, when a block water temperature is a warming-up completion determination temperature or less. Here, the ECU 60 completely closes a head flow rate control valve 21 when the block water temperature is a heater water temperature or more, and drives the head flow rate control valve 21 to a valve opening side according to temperature difference between the block water temperature and the head water temperature when the block water temperature is less than the head water temperature.

Description

  The present invention relates to an engine cooling apparatus.

  Conventionally, in a water-cooled engine, a thermostat is provided on a cooling water circulation path, and when the engine is warmed up, the cooling water path is switched by the thermostat so as to bypass the radiator and the warm-up proceeds. Further, in a vehicle equipped with a water-cooled engine, a configuration in which a part of cooling water heated by the engine is used as a heat source of a heater for heating a vehicle is widely used.

  For example, in Patent Document 1, a cylinder head having the same shape can be shared by engines having different cooling water circulation methods (longitudinal flow method, U-turn flow method), and production management can be facilitated and costs can be reduced. An engine cooling structure is disclosed. In this engine cooling structure, a water pump that forcibly circulates cooling water, a radiator that dissipates the heat of the cooling water to the outside, a heater that heats the cooling water using the heat of the cooling water, and a cooling water And a thermostat that automatically operates in accordance with the water temperature and switches and changes the cooling water passage. A radiator supply passage for supplying cooling water from the engine to the radiator, a heater return passage for returning the cooling water from the engine (cylinder head) to the heater, and a bypass passage for returning the cooling water directly from the engine to the water pump are provided. It has been.

  In this engine cooling structure, the cooling water that has flowed inside the cylinder block and the cylinder head is discharged through a first cooling water outlet formed in the rear wall of the cylinder head. The discharged cooling water is supplied to the radiator through the radiator supply passage and is also supplied to the heater through the heater supply passage.

  Patent Document 2 discloses an engine cooling device that can improve the heating effect of the heater during heating operation or during light load operation after warm-up operation. In this engine cooling device, the water jacket of the cylinder head and the water jacket of the cylinder block are formed independently (so-called two-system cooling), and the merging with the outflow side passage of the cylinder head in the outflow side passage of the cylinder block A temperature sensing valve (thermo valve) is provided upstream of the unit. By this temperature sensing valve, the temperature of the cooling water flowing through the water jacket of the cylinder block is set higher (for example, 90 ° C. or higher) than the temperature of the cooling water flowing through the cylinder head, while the cylinder block is in the heater-on state. Cooling water upstream of the temperature sensing valve in the outflow side passage of the gas is introduced into the upper part of the heater through the switching valve.

  According to this engine cooling device, when the heater is turned on, the cooling water of the cylinder head and the cooling water of the cylinder block whose cooling water temperature is higher than that of the cylinder head are always introduced into the heater. The heating effect of the heater can be enhanced during warm-up operation with poor heating and during light load operation.

JP 2004-21645 A JP-A-62-99616

  By the way, in recent years, further improvement in fuel efficiency has been demanded. From such a viewpoint, when the engine is warmed up, the cylinder block (especially the combustion chamber surface) is warmed up, so that the viscosity of the engine oil is accelerated. It is desirable to reduce the engine friction. On the other hand, from the viewpoint of improving passenger comfort, it is desirable to shorten the vehicle heating preparation time (that is, the time until the engine warms up and the coolant temperature rises and the heating becomes available). Yes.

  However, in the engine cooling structure described in Patent Document 1, the cooling water discharged from the water pump is sent from the water jacket formed in the cylinder block to the heater / radiator through the water jacket of the cylinder head. Therefore, all the cooling water is heated up on average, and the selective early warm-up of the cylinder block cannot be achieved. Moreover, although the cooling water for heaters is taken from the cylinder head side, as mentioned above, since all the cooling water is warmed on average, it is difficult to shorten the vehicle interior heating preparation time. Furthermore, when the heater is used in the vicinity of the maximum capacity, that is, when heat dissipation in the vehicle interior heating is large, the temperature of the cylinder block or the like may be excessively lowered.

  On the other hand, the engine cooling device described in Patent Document 2 employs an independent cooling system for the cylinder block and the cylinder head, that is, two-system cooling. When the heater is not used, the thermo valve and the switching valve are closed. Since it will be in a state, the warm-up property of a cylinder block can be improved. However, when the heater is turned on, the switching valve is opened, and cooling water flows from the upstream side of the switching valve (that is, the cylinder block side) to the heater. Therefore, the temperature of the cylinder block (cooling water) decreases. Therefore, when the heater is used, the warm-up property of the cylinder block may be impaired. Further, in this engine cooling device, the cooling water flowing out from the cylinder block and the cooling water flowing out from the cylinder head are mixed (that is, the water temperature is averaged) and supplied to the heater, so that the heater starts to work. It is difficult to shorten the time (preparation time for heating inside the vehicle). Furthermore, when the heat radiation at the heater is increased, the water temperature of the engine (cylinder block) may be greatly reduced.

  The present invention has been made to solve the above problems, and can warm up the cylinder block early and shorten the preparation time for the interior heating when the engine is warmed up. An object of the present invention is to provide an engine cooling device that can prevent the temperature of a cylinder block from excessively decreasing while ensuring heating performance.

  An engine cooling apparatus according to the present invention includes a first cooling water passage including a water jacket formed in a cylinder head, and a water jacket provided in parallel with the first cooling water passage and formed in the cylinder block. The second cooling water passage and one end are communicated with a joining portion of the first cooling water passage and the second cooling water passage, and the other end is communicated with a branch portion between the first cooling water passage and the second cooling water passage. The third cooling water passage, the radiator disposed in the third cooling water passage and performing heat exchange between the cooling water and the atmosphere, and the third cooling water passage, pressurizing the cooling water. The first cooling water pump to be discharged, the first temperature detecting means for detecting the temperature of the cooling water in the first cooling water passage as the first temperature, and the temperature of the cooling water in the second cooling water passage are detected as the second temperature. 2nd temperature detection means and the water jacket of the 1st cooling water passage A first valve that opens and closes the first cooling water passage; a second valve that opens and closes the third cooling water passage; and one end upstream of the first valve in the first cooling water passage. And the other end is disposed in the fourth cooling water passage and the fourth cooling water passage which is communicated with the downstream side of the branch portion in the first cooling water passage, and the second cooling water is pressurized and discharged. A cooling water pump, a heater core that is disposed in the fourth cooling water passage and exchanges heat with the cooling water, and the first valve and the second valve based on the first temperature and / or the second temperature. , A first cooling water pump, and a control means for controlling the second cooling water pump. When the control temperature is equal to or lower than a predetermined warm-up completion determination temperature, the second valve Is fully closed, the second cooling water pump is driven according to the heating request state, and the second temperature is When the temperature is equal to or lower than the machine completion determination temperature and equal to or higher than the first temperature, the first valve is fully closed, and when the second temperature is equal to or lower than the warm-up completion determination temperature and lower than the first temperature, the second temperature is set. The first valve is driven to the valve opening side according to the temperature difference between the first temperature and the first temperature.

  According to the engine cooling device of the present invention, when the second temperature is equal to or lower than the warm-up completion determination temperature (that is, during warm-up) and equal to or higher than the first temperature, the first valve is fully closed. . Therefore, the communication between the first coolant passage (and the fourth coolant passage) passing through the cylinder head and the second coolant passage (and the third coolant passage) passing through the cylinder block is blocked (that is, the passage is The cooling water on the low-temperature cylinder head side is prevented from flowing into the cylinder block side. Therefore, warming up of the cylinder block can be promoted. On the other hand, when the second temperature is lower than the first temperature, the first valve is driven to the valve opening side according to the temperature difference between the second temperature and the first temperature. For this reason, the first cooling water passage (and the fourth cooling water passage) and the second cooling water passage (and the third cooling water passage) that pass through are communicated with each other, and the higher-temperature cylinder head side cooling water flows into the cylinder block side. To do. Therefore, warming up of the cylinder block can be further promoted.

  By the way, the cylinder head has a smaller heat capacity than the cylinder block and is formed with an exhaust port or the like that has a high temperature. Here, according to the engine cooling device of the present invention, the second cooling water pump is driven according to the heating request state, and the cooling water on the cylinder head side (fourth cooling water passage) that is more likely to rise in temperature is used. And can be heated. Therefore, the vehicle interior heating preparation time can be shortened when the engine is warmed up. Furthermore, as described above, the first cooling water passage (and the fourth cooling water passage) and the second cooling water passage (and the third cooling water passage) can be separated by fully closing the first valve. it can. Therefore, for example, even after the warm-up is completed, it is possible to prevent the temperature of the cylinder block from being excessively lowered while ensuring the heating performance when using the vehicle interior heating. As a result of the above, when the engine is warmed up, the cylinder block can be warmed up quickly and the preparation time for heating the interior of the vehicle can be shortened. It is possible to prevent the decrease.

  The engine cooling device according to the present invention has one end communicating with the upstream side of the radiator in the third cooling water passage and the other end between the second valve and the first cooling water pump in the third cooling water passage. A bypass passage that is communicated and bypasses the radiator, and a third valve that opens and closes the bypass passage, the second temperature is higher than the warm-up completion determination temperature, and a preset predetermined external heat release determination temperature In the following cases, the control means may fully close the second valve, fully open the third valve, and drive the first cooling water pump so as to adjust the discharge amount according to the second temperature. preferable.

  In this way, when the second temperature is higher than the warm-up completion determination temperature and not more than the external heat dissipation determination temperature, the second valve is fully closed and the third valve is fully opened. Thus, external heat dissipation from the radiator can be stopped. At that time, the discharge amount of the first cooling water pump is adjusted according to the second temperature. For this reason, after the cylinder block has been warmed up, the cylinder block (the second block) is maintained in accordance with the temperature rise of the cylinder block while maintaining the cylinder block warm-up state (that is, without reducing the temperature of the cylinder block). The cooling water can be circulated through the cooling water passage), the third cooling water passage, and the bypass passage. Therefore, it is possible to diffuse heat throughout the cylinder block while maintaining the warm-up state of the cylinder block.

  In the engine cooling device according to the present invention, when the second temperature is higher than the external heat radiation determination temperature, the control means opens the first valve, opens the second valve fully, and fully closes the third valve. In addition, it is preferable to drive the first cooling water pump.

  In this way, when the second temperature is higher than the external heat release determination temperature, the first cooling water passage (and the fourth cooling water passage) and the second cooling water passage (and the third cooling water passage) communicate with each other. Thus, the heat of the cooling water on the cylinder block side and the cooling water on the cylinder head side can be dissipated to the outside from the radiator.

  In the engine cooling device according to the present invention, when the second temperature is higher than the external heat radiation determination temperature, the control means determines the discharge amount of the first cooling water pump based on the second temperature and the engine load. It is preferable to make it variable.

  In this way, when the second temperature is higher than the external heat radiation determination temperature, the temperature of the cooling water can be adjusted so as to suppress the temperature change of the cylinder block (that is, to maintain the optimum temperature). it can.

  In the engine cooling apparatus according to the present invention, when the second temperature is higher than the external heat release determination temperature and the engine is operating at a high load, the control means drives the first cooling water pump at the maximum discharge amount. In addition, it is preferable to drive the second cooling water pump with the maximum discharge amount regardless of the heating request state.

  In this way, the flow rate of the cooling water flowing through the cylinder head and the cylinder block is increased when the second temperature is higher than the external heat release determination temperature and the high load operation (that is, when the engine heat generation amount is large). Can do. Therefore, the heat transfer coefficient of the cylinder head and the cylinder block can be increased and the cooling capacity can be improved. As a result, knocking can be suppressed and output can be improved.

  In the engine cooling apparatus according to the present invention, it is preferable that the control means stops driving the second coolant pump when there is no heating request.

  In this way, when heating is not used, the warm-up can be further accelerated by stopping the circulation of the cooling water on the heater core side.

  The engine cooling device according to the present invention preferably further includes a heat source that is interposed in the fourth cooling water passage and raises the temperature of the cooling water flowing through the fourth cooling water passage.

  In this case, by providing a heat source that raises the temperature of the cooling water flowing through the fourth cooling water passage, warm air can be further promoted. In addition, it is possible to further shorten the heating preparation time when the engine is warmed up. Furthermore, heating performance can be ensured even when the engine is stopped, for example, by idling stop.

  In the engine cooling device according to the present invention, it is preferable that the fourth cooling water passage is formed so as to pass in the vicinity of the exhaust port formed in the cylinder head.

  In this way, since the cooling water flows in the vicinity of the exhaust port that becomes high in temperature, the temperature rise of the cooling water on the cylinder head side can be further promoted. Therefore, it is possible to further shorten the heating preparation time when the engine is warmed up.

  According to the present invention, when the engine is warmed up, the cylinder block can be warmed up early and the heating time for the vehicle interior heating can be shortened. Can be prevented from excessively decreasing.

It is a block diagram which shows the whole structure of the cooling device of the engine which concerns on embodiment. It is a flowchart which shows the process sequence of the cooling process by the cooling device of the engine which concerns on embodiment. It is a table | surface which shows device operation for every cooling mode / control mode.

  DESCRIPTION OF EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. In addition, in each figure, the same code | symbol is attached | subjected to the same element and the overlapping description is abbreviate | omitted.

  First, the configuration of the engine cooling device 1 according to the embodiment will be described with reference to FIG. FIG. 1 is a block diagram showing the overall configuration of an engine cooling device 1.

  The engine 5 is, for example, a water-cooled horizontally opposed four-cylinder gasoline engine. In the engine 5, the air taken in from the air cleaner is throttled by the throttle valve and sucked into each cylinder formed in the engine 5. Here, the amount of inhaled air is detected by a hot wire type air flow meter 61 disposed between the air cleaner and the throttle valve.

  In each cylinder, the mixture of intake air and fuel is combusted, and the exhaust gas after the combustion is discharged to an exhaust pipe through an exhaust port and an exhaust manifold. The heat generated by the combustion of the air-fuel mixture is released to the cooling water in the water jacket 11a provided in the cylinder head 5H of the engine 5 and in the water jacket 12a provided in the cylinder block 5B.

  A first cooling water passage 11 including a water jacket 11a formed in the cylinder head 5H is attached to the cylinder head 5H of the engine 5. On the other hand, the cylinder block 5B of the engine 5 is provided with a second cooling water passage 12 provided in parallel with the first cooling water passage 11 and including a water jacket 12a formed in the cylinder block 5B.

  In the vicinity of the outlet of the water jacket 11a of the cylinder head 5H, the temperature of the cooling water in the first cooling water passage 11 (corresponding to the first temperature described in the claims, hereinafter referred to as “head water temperature”) is detected. A head water temperature sensor (corresponding to the first temperature detecting means described in claims) 51 is attached. The head water temperature sensor 51 is connected to an electronic control device (hereinafter referred to as “ECU”) 60 described later, and the detected temperature of the cooling water is output to the ECU 60. On the other hand, in the vicinity of the outlet of the water jacket 12a of the cylinder block 5B, the temperature of the cooling water in the second cooling water passage 12 (corresponding to the second temperature described in the claims, hereinafter referred to as “block water temperature”). A block water temperature sensor 52 (corresponding to the second temperature detection means described in the claims) 52 for detection is attached. The block water temperature sensor 52 is connected to the ECU 60, and the detected temperature of the cooling water is output to the ECU 60.

  One end of the third cooling water passage 13 is communicated with the joining portion 123 of the first cooling water passage 11 and the second cooling water passage 12. On the other hand, the other end of the third cooling water passage 13 communicates with a branch portion 321 between the first cooling water passage 11 and the second cooling water passage 12.

  A radiator 41 is interposed in the third cooling water passage 13. The radiator 41 is a heat exchanger that performs heat exchange between the cooling water and the atmosphere. When the cooling water passes through the radiator core portion composed of the tubes and the fins, the heat of the cooling water is released to the atmosphere.

  A radiator flow rate control valve 22 that adjusts the flow rate of the cooling water flowing through the radiator 41 by opening and closing the third cooling water passage 13 on the downstream side of the radiator 41 in the third cooling water passage 13 (within claims) Corresponding to the second valve described). Here, as the radiator flow control valve 22, for example, an electric ball valve that adjusts the flow rate by driving the ball valve with an electric motor and continuously changing the opening area is preferably used. The radiator flow control valve 22 is connected to the ECU 60 and is controlled by the ECU 60.

  A first cooling water pump 31 that pressurizes and discharges cooling water is disposed on the downstream side of the radiator flow rate control valve 22 in the third cooling water passage 13. In the present embodiment, an electric water pump that is driven by an electric motor and that can continuously vary the discharge amount is used as the first cooling water pump 31. The first cooling water pump 31 is connected to the ECU 60 and is controlled by the ECU 60.

  Connected to the third cooling water passage 13 are a first bypass passage 15 and a second bypass passage 16 for circulating the cooling water without passing through the radiator 41. One end of each of the first bypass passage 15 and the second bypass passage 16 is communicated with the upstream side of the radiator 41 in the third cooling water passage 13, and the other end of each is the radiator flow rate control valve 22 in the third cooling water passage 13. And the first cooling water pump 31. The first bypass passage 15 is provided with a bypass flow rate control valve (corresponding to a third valve described in claims) that opens and closes the first bypass passage 15. For the bypass flow rate control valve 23, for example, an electric ball valve or the like is preferably used, similarly to the radiator flow rate control valve 22 described above. The bypass flow rate control valve 23 is connected to the ECU 60 and is controlled by the ECU 60.

  The first bypass passage 15 is a passage that can stop the supply of cooling water depending on the warm-up state or the operating state of the engine 5. On the other hand, the second bypass passage 16 is a passage in which the supply of cooling water cannot be stopped regardless of whether the engine 5 is warmed up or operated in order to cool a high temperature part such as a bearing of a turbocharger. In addition, when there is no site | part which cannot stop supply of cooling water, it is not necessary to provide the 2nd bypass channel 16.

  Between the outlet of the water jacket 11a of the first cooling water passage 11 and the merging portion 123, a head flow rate control valve 21 (corresponding to the first valve described in the claims) that opens and closes the first cooling water passage 11 is provided. Is provided. For the head flow rate control valve 21, for example, an electric ball valve or the like is preferably used in the same manner as the radiator flow rate control valve 22 described above. The head flow control valve 21 is connected to the ECU 60 and is controlled by the ECU 60.

  One end of the fourth cooling water passage 14 communicates with the upstream side of the head flow rate control valve 21 in the first cooling water passage 11. On the other hand, the other end of the fourth cooling water passage 14 communicates with the downstream side of the branch portion 321 in the first cooling water passage 11. That is, the fourth cooling water passage 14 shares the water jacket 11a of the cylinder head 5H with the first cooling water passage 11 described above. The fourth cooling water passage 14 (water jacket 11a) passes in the vicinity of the exhaust port formed in the cylinder head 5H in the cylinder head 5H, and a discharge port is provided in the vicinity of the exhaust port. It is preferable.

  The fourth cooling water passage 14 is provided with a second cooling water pump 32 that pressurizes and discharges the cooling water. In the present embodiment, an electric water pump is used as the second cooling water pump 32 in the same manner as the first cooling water pump 31 described above. The second cooling water pump 32 is controlled by an ECU 60 described later.

  A heater core 42 for exchanging heat with the cooling water is disposed upstream of the second cooling water pump 32 in the fourth cooling water passage 14. The heater core 42 is a heat dissipating device for in-vehicle air conditioning (heating) that is configured by tubes and fins and that exchanges heat when cooling water flows through the tubes. A blower blower (not shown) is disposed outside the passenger compartment of the heater core 42. The blower is a blower that includes a fan and a blower motor. The heat discharged from the heater core is supplied into the passenger compartment by the wind blown from the blower blower. The blower blower is connected to the ECU 60, and the rotational speed of the blower motor that rotates the fan is controlled by the ECU 60. By controlling the rotational speed of the fan, the amount of air blown into the passenger compartment is adjusted, and the amount of heat supplied to the passenger compartment is adjusted.

  Further, for example, a positive temperature coefficient (PTC) thermistor is used as a heating element on the upstream side of the heater core 42 in the fourth cooling water passage 14 in order to raise the temperature of the cooling water in the fourth cooling water passage 14. The electric heater (corresponding to the heat source described in the claims, hereinafter referred to as “PTC heater”) 43 is disposed. The PTC heater 43 is connected to the ECU 60. For example, the amount of electric power supplied to the PTC heater 43 is adjusted by the ECU 60 according to the temperature of the cooling water, whereby the amount of heat generated by the PTC heater 43 is controlled. The PTC heater 43 is not indispensable, but for example, when a generator with a large power generation capacity or a battery with a large power storage capacity is mounted, such as a hybrid vehicle, the PTC heater 43 is added, so that heating and The PTC heater 43 can be used for both warm-up promotion applications.

  The operation of the engine 5 and the engine cooling device 1 is controlled by the ECU 60. That is, the ECU 60 functions as a control unit described in the claims. The ECU 60 stores the contents stored therein by a microprocessor that performs calculations, a ROM that stores a program for causing the microprocessor to execute each process, a RAM that stores various data such as calculation results, and a 12V battery. A backup RAM or the like.

  The ECU 60 includes the head water temperature sensor 51, the block water temperature sensor 52, the first cooling water pump 31, the second cooling water pump 32, the head flow rate control valve 21, the radiator flow rate control valve 22, the bypass flow rate control valve 23, and In addition to the PTC heater 43, an air flow meter 61 for detecting the intake air amount of the engine 5, a crank angle sensor 62 for detecting a crank position (engine speed), and the like are connected. The ECU 60 includes a motor driver circuit that drives the first cooling water pump 31 and the second cooling water pump 32, a head flow control valve 21, a radiator flow control valve 22, a motor driver circuit that drives the bypass flow control valve 23, and And an output circuit for operating the PTC heater 43.

  The ECU 60 calculates control values such as the fuel injection amount and the ignition timing based on inputs from various sensors. Then, the operation of the engine 5 is comprehensively controlled based on the calculated control value. Further, the ECU 60 controls the head flow rate control valve 21, the radiator flow rate control valve 22, the bypass flow rate control valve 23, the first cooling water based on the head water temperature, the block water temperature, and / or the operation state (load state) of the engine 5. The pump 31 and the second cooling water pump 32 are controlled.

  More specifically, the ECU 60 fully closes the radiator flow control valve 22 when the block water temperature is equal to or lower than a predetermined warm-up completion determination temperature (for example, 40 to 50 ° C.) (that is, during warm-up). To. Thereby, the heat radiation from the radiator 41 to the outside is prevented. Further, the ECU 60 opens the bypass flow rate control valve 23 to a necessary opening degree so that the coolant flow rate becomes a necessary flow rate (for example, the minimum flow rate for preventing surface boiling), and the first coolant pump 31 The discharge amount is adjusted (see the warming-up mode in FIG. 3). Further, the ECU 60 drives the second cooling water pump 32 in accordance with a heating request state (for example, heating switch on / off, heating set temperature, vehicle interior temperature, fan air volume, etc.). In addition, when there is no heating request | requirement, the drive of the 2nd cooling water pump 32 is stopped.

  Further, the ECU 60 fully closes the head flow rate control valve 21 when the block water temperature is equal to or higher than the head water temperature. Thereby, the communication between the first cooling water passage 11 (and the fourth cooling water passage 14) on the cylinder head 5H side and the second cooling water passage 12 (and the third cooling water passage 13) on the cylinder block 5B side is blocked ( The passage is separated), and low-temperature cooling water on the cylinder head 5H side is prevented from flowing into the cylinder block 5B side. On the other hand, when the block water temperature is lower than the head water temperature, the ECU 60 drives the head flow control valve 21 to the valve opening side according to the temperature difference between the block water temperature and the head water temperature. As a result, the first cooling water passage 11 (and the fourth cooling water passage 14) and the second cooling water passage 12 (and the third cooling water passage 13) communicate with each other, and the higher-temperature cylinder head 5H side cooling water flows. It flows into the cylinder block 5B side.

  Further, the ECU 60 has a block water temperature higher than the warm-up completion determination temperature and a predetermined external heat release start determination temperature (for example, 80 to 100 ° C.) set in advance (external heat release determination according to claims) In the following cases, the radiator flow control valve 22 is fully closed and the bypass flow control valve 23 is fully opened. Thereby, the heat radiation from the radiator 41 to the outside is prevented. Further, the ECU 60 drives the first cooling water pump 31 so as to adjust the discharge amount according to the block water temperature (that is, the discharge amount increases as the block water temperature increases) (see the external heat dissipation stop mode in FIG. 3). ). Thereby, after the warm-up of the cylinder block 5B is completed, the warm-up state of the cylinder block 5B is maintained (that is, without reducing the temperature of the cylinder block 5B), and the temperature of the cylinder block 5B is adjusted. Cooling water is circulated through the cylinder block 5B (second cooling water passage 12), the third cooling water passage 13, and the first and second bypass passages 15 and 16.

  At that time, the ECU 60 drives the second coolant pump 32 according to the heating request state. In addition, when there is no heating request | requirement, the drive of the 2nd cooling water pump 32 is stopped. Further, the ECU 60 fully closes the head flow rate control valve 21 when the block water temperature is equal to or higher than the head water temperature. On the other hand, when the block water temperature is lower than the head water temperature, the ECU 60 drives the head flow control valve 21 to the valve opening side according to the temperature difference between the block water temperature and the head water temperature.

  On the other hand, when the block water temperature is higher than the external heat release start determination temperature, the ECU 60 fully opens the head flow control valve 21, controls the radiator flow control valve 22 to the fully open side, and fully closes the bypass flow control valve 23. (Refer to the external heat radiation mode in FIG. 3). Here, the opening degree of each of the radiator flow control valve 22 and the bypass flow control valve 23 is such that the block water temperature changes with time and / or the engine load (engine heat generation amount) so that the block water temperature is maintained at an optimum temperature. It is preferable to set in consideration of the above. Further, the ECU 60 varies the discharge amount of the first cooling water pump 31 based on the block water temperature and the engine load. The engine load (engine heat generation amount) can be calculated based on the intake air amount Ga and the engine speed Ne, for example.

  Thus, when the block water temperature is higher than the external heat release start determination temperature, the heat of the cooling water on the cylinder block 5B side and the cooling water on the cylinder head 5H side is dissipated from the radiator 41 to the outside. Further, the temperature of the cooling water is adjusted so as to suppress the temperature change of the cylinder block 5B (that is, to maintain the optimum temperature).

  Further, the ECU 60 drives the first cooling water pump 31 at the maximum discharge amount and the second cooling water pump when the block water temperature is higher than the external heat radiation start determination temperature and the engine 5 is operated at a high load. 32 is driven with the maximum discharge amount regardless of the heating request state. Thereby, the flow volume of the cooling water which flows through the cylinder head 5H and the cylinder block 5B increases. Therefore, the heat transfer rates of the cylinder head 5H and the cylinder block 5B are increased, and the cooling capacity is improved.

  Next, the operation of the engine cooling device 1 will be described with reference to FIGS. FIG. 2 is a flowchart showing a processing procedure of cooling processing by the engine cooling device 1. FIG. 3 is a list showing device operation (operation of each device) for each cooling mode / control mode. This process is repeatedly executed in the ECU 60 at a predetermined timing.

  First, in step S100, the head water temperature detected by the head water temperature sensor 51 and the block water temperature detected by the block water temperature sensor 52 are read.

  Next, in step S102, it is determined whether or not the block water temperature is equal to or lower than the warm-up completion determination temperature (for example, 40 to 50 ° C.), that is, whether or not the warm-up in the combustion chamber and around the cylinder is completed. Here, when the block water temperature is equal to or lower than the warm-up completion determination temperature (in the middle of warm-up), the process proceeds to step S104. On the other hand, when the block water temperature is higher than the warm-up completion determination temperature (when the warm-up is completed), the process proceeds to step S112.

  In step S104, the radiator flow control valve 22 is fully closed. Further, the bypass flow rate control valve 23 is opened by a necessary opening degree so that the cooling water flow rate becomes a necessary flow rate (for example, the minimum flow rate for preventing surface boiling), and the discharge amount of the first cooling water pump 31. Is adjusted. Further, the second cooling water pump 32 is driven according to a heating request state (for example, on / off of a heating switch, heating set temperature, vehicle interior temperature, fan air volume, etc.). In addition, when there is no heating request | requirement, the drive of the 2nd cooling water pump 32 is stopped (refer warming-up mode of FIG. 3).

  Subsequently, in step S106, it is determined whether or not the block water temperature is lower than the head water temperature. If the block water temperature is lower than the head water temperature, the process proceeds to step S108. On the other hand, when the block water temperature is equal to or higher than the head water temperature, the process proceeds to step S110.

  In step S108, the head flow rate control valve 21 is driven to the valve opening side according to the temperature difference between the block water temperature and the head water temperature (see the warming-up mode in FIG. 3). Thereafter, the process is temporarily exited.

  On the other hand, in step S110, the head flow control valve 21 is fully closed (see the warming-up mode in FIG. 3). Thereafter, the process is temporarily exited.

  When the block water temperature is higher than the warm-up completion determination temperature, in step S112, it is determined whether or not the block water temperature is equal to or lower than the external heat release start determination temperature (for example, 80 to 100 ° C.). That is, a determination is made as to whether or not the entire engine has been warmed up. If the block water temperature is equal to or lower than the external heat release start determination temperature, the process proceeds to step S114. On the other hand, when the block water temperature is higher than the external heat release start determination temperature, the process proceeds to step S116.

  In step S114, the radiator flow control valve 22 is fully closed and the bypass flow control valve 23 is fully opened. Further, the first cooling water pump 31 is driven so as to adjust the discharge amount in accordance with the block water temperature (that is, the discharge amount increases as the block water temperature increases) (see the external heat radiation stop mode in FIG. 3). Further, the second cooling water pump 32 is driven according to a heating request state (for example, on / off of a heating switch, heating set temperature, vehicle interior temperature, fan air volume, etc.). In addition, when there is no heating request | requirement, the drive of the 2nd cooling water pump 32 is stopped. Thereafter, the process proceeds to step S106. In addition, since the process after step S106 is as above-mentioned, detailed description is abbreviate | omitted here.

  On the other hand, in step S116, the head flow control valve 21 is fully opened, the radiator flow control valve 22 is controlled to the fully open side, and the bypass flow control valve 23 is controlled to the fully closed side. Further, the discharge amount of the first cooling water pump 31 is adjusted based on the block water temperature and the engine load (engine heat generation amount) (see the external heat dissipation mode in FIG. 3). The engine load (engine heat generation amount) can be calculated based on the intake air amount Ga and the engine speed Ne, for example.

  Subsequently, in step S118, a determination is made as to whether or not the engine 5 is operating at a high load. Here, when the engine 5 is not operated at a high load, the process proceeds to step S120. On the other hand, when the engine 5 is operating at a high load, the process proceeds to step S122.

  In step S120, the second cooling water pump 32 is driven according to the heating request state. In addition, when there is no heating request | requirement, the drive of the 2nd cooling water pump 32 is stopped. Thereafter, the process is temporarily exited.

  On the other hand, when the block water temperature is higher than the external heat release start determination temperature and the engine 5 is operating at a high load, the first cooling water pump 31 is driven at the maximum discharge amount and the second cooling is performed in step S122. The water pump 32 is driven at the maximum discharge amount regardless of the heating request state. Thereafter, the process is temporarily exited.

  As described above in detail, according to the present embodiment, when the block water temperature is equal to or lower than the warm-up completion determination temperature (that is, during warm-up) and equal to or higher than the head water temperature, the head flow control valve 21 is fully Closed. Therefore, the communication 123 between the first coolant passage 11 (and the fourth coolant passage 14) passing through the cylinder head 5H and the second coolant passage 12 (and the third coolant passage 13) passing through the cylinder block 5B is provided. The cooling water on the low-temperature cylinder head 5H side is blocked from flowing into the cylinder block 5B side. Therefore, warming up of the cylinder block 5B can be promoted. On the other hand, when the block water temperature is lower than the head water temperature, the head flow control valve 21 is driven to the valve opening side according to the temperature difference between the block water temperature and the head water temperature. Therefore, the first cooling water passage 11 (and the fourth cooling water passage 14) and the second cooling water passage 12 (and the third cooling water passage 13) communicate with each other, and the higher-temperature cylinder head 5H side cooling water is supplied to the cylinder. It flows into the block 5B side. Therefore, warming up of the cylinder block 5B can be further promoted. In this case, the radiator flow rate control valve 22 is fully closed, so that heat radiation from the radiator 41 to the outside is prevented.

  Further, at that time, according to the engine cooling apparatus 1 according to the present embodiment, the second cooling water pump 32 is driven according to the heating request state, and the cooling water on the cylinder head 5H side that is more likely to rise in temperature is used. And can be heated. Therefore, the vehicle interior heating preparation time can be shortened when the engine is warmed up. Further, as described above, by fully closing the head flow rate control valve 21, the first cooling water passage 11 (and the fourth cooling water passage 14) and the second cooling water passage 12 (and the third cooling water passage 13). And can be separated. Therefore, for example, even after the warm-up is completed, it is possible to prevent the temperature of the cylinder block 5H from excessively decreasing while ensuring the heating performance when using the vehicle interior heating. As a result of the above, when the engine is warmed up, the cylinder block 5B can be warmed up quickly and the time for preparing heating in the vehicle can be shortened. Can be prevented from excessively decreasing.

  According to the present embodiment, when the block water temperature is higher than the warm-up completion determination temperature and equal to or lower than the external heat release start determination temperature, the radiator flow control valve 22 is fully closed and the bypass flow control valve 23 is By being fully opened, the external heat radiation from the radiator 41 can be stopped. Further, at that time, since the discharge amount of the first cooling water pump 31 is adjusted according to the block water temperature, the warm-up state of the cylinder block 5B is maintained after the warm-up of the cylinder block 5B is completed (that is, The cylinder block 5B (second cooling water passage 12), the third cooling water passage 13, the first and second bypass passages 15 are matched to the temperature rise of the cylinder block 5B (without reducing the temperature of the cylinder block 5B). , 16 can circulate cooling water. Therefore, it is possible to diffuse heat throughout the cylinder block 5B while maintaining the warm-up state of the cylinder block 5B.

  According to this embodiment, when the block water temperature is higher than the external heat release start determination temperature, the head flow control valve 21 is fully opened, the radiator flow control valve 22 is fully opened, and the bypass flow control valve 23 is fully closed. And the first cooling water pump 31 is driven. Therefore, the first cooling water passage 11 (and the fourth cooling water passage 14) and the second cooling water passage 12 (and the third cooling water passage 13) communicate with each other, and the cooling water on the cylinder block 5B side and the cylinder head 5H side. It becomes possible to dissipate the heat of each cooling water from the radiator 41 to the outside.

  According to this embodiment, when the block water temperature is higher than the external heat release start determination temperature, the discharge amount of the first cooling water pump 31 is varied based on the block water temperature and the engine load. Therefore, it is possible to adjust the temperature of the cooling water so as to suppress the temperature change of the cylinder block 5B (that is, to maintain the optimum temperature).

  According to this embodiment, when the block water temperature is higher than the external heat release start determination temperature and the engine is operating at a high load, the first cooling water pump 31 is driven at the maximum discharge amount and the second cooling is performed. The water pump 32 is driven at the maximum discharge amount regardless of the heating request state. Therefore, the flow rate of the cooling water flowing through the cylinder head 5H and the cylinder block 5B can be increased when the block water temperature is higher than the external heat release start determination temperature and during high load operation (that is, when the engine heat generation amount is large). . Therefore, the heat transfer coefficient of the cylinder head 5H and the cylinder block 5B can be increased to improve the cooling capacity. As a result, knocking can be suppressed and output can be improved.

  According to the present embodiment, when there is no heating request, the driving of the second cooling water pump 32 is stopped. Therefore, when heating is not used, the warm-up can be further accelerated by stopping the circulation of the cooling water on the cylinder head 5H side.

  According to this embodiment, warm air can be further promoted by providing the PTC heater 43 that raises the temperature of the coolant flowing through the fourth coolant passage 14. In addition, it is possible to further shorten the heating preparation time when the engine is warmed up. Furthermore, heating performance can be ensured even when the engine is stopped, for example, by idling stop.

  According to the present embodiment, the fourth cooling water passage 14 is formed so as to pass in the vicinity of the exhaust port formed in the cylinder head 5H. Therefore, since the temperature rise of the cooling water on the cylinder head 5H side can be further promoted, the heating preparation time can be further shortened when the engine is warmed up.

  In addition, according to the present embodiment, for example, when there is a circuit (second bypass passage 16) in which the supply of cooling water cannot be stopped in order to cool a high temperature part such as a bearing of a turbocharger, the circuit (second bypass) The passage 16), the cylinder block 5B (second cooling water passage 12), and the first cooling water pump 31 constitute a circuit in which the cooling water is constantly circulated. Therefore, it is possible to improve the temperature heat retention of the cylinder block 5B without diffusing heat.

  Further, according to the present embodiment, for example, even when the engine 5 is stopped due to idling stop or the like, the heat stored in the cylinder head 5H and the cylinder block 5B are driven by driving the second cooling water pump 32. Thus, heating can be performed using the heat transmitted through the joint to the cylinder head 5H, and the reduction in heating capacity can be moderated. In addition, since heat transfer from the cylinder block 5B is limited to heat transfer at the joint with the cylinder head 5H, the temperature of the cooling water is less lowered than when all the cooling water is circulated, and it is easy to maintain the warm-up state. . Therefore, for example, the combustion state at the time of restart after idling stop can be made better.

  Further, according to the present embodiment, since the head flow rate control valve 21 is opened, the first coolant passage 11, the fourth coolant passage 14, and the third coolant passage 13 can be communicated with each other. For example, even if the second cooling water pump 32 provided in the fourth cooling water passage 14 fails, a system that does not affect the cooling system in the warm-up completion state can be constructed.

  Although the embodiment of the present invention has been described above, the present invention is not limited to the above embodiment, and various modifications can be made. For example, in the above embodiment, the PTC heater 42 is disposed in the fourth cooling water passage 14, but instead of the PTC heater 42, for example, a heat exchanger for heating (such as a heat pump) may be used. It is not essential to provide the PTC heater 42 or the like.

  In the above embodiment, the radiator flow rate control valve 22 is disposed in the third coolant passage 13 and the bypass flow rate control valve 23 is disposed in the first bypass passage 15, but instead of these flow rate control valves, It is good also as a structure using a mixing valve, a thermostat, etc.

  In the said embodiment, although the electric water pump was used as the 1st cooling water pump 31, it may replace with an electric water pump and may use the mechanical pump driven by the engine 5, for example.

DESCRIPTION OF SYMBOLS 1 Engine cooling device 5 Engine 5H Cylinder head 5B Cylinder block 11 1st cooling water passage 12 2nd cooling water passage 13 3rd cooling water passage 14 4th cooling water passage 15 1st bypass passage 16 2nd bypass passage 123 Merge part 321 Branching section 21 Head flow control valve 22 Radiator flow control valve 23 Bypass flow control valve 31 First cooling water pump 32 Second cooling water pump 41 Radiator 42 Heater core 43 PTC heater 51 Head water temperature sensor 52 Block water temperature sensor 60 ECU

Claims (8)

A first cooling water passage including a water jacket formed in the cylinder head;
A second cooling water passage provided in parallel with the first cooling water passage and including a water jacket formed in the cylinder block;
One end is communicated with a junction between the first cooling water passage and the second cooling water passage, and the other end is communicated with a branch portion between the first cooling water passage and the second cooling water passage. 3 cooling water passages,
A radiator disposed in the third cooling water passage and performing heat exchange between the cooling water and the atmosphere;
A first cooling water pump disposed in the third cooling water passage and pressurizing and discharging the cooling water;
First temperature detecting means for detecting the temperature of the cooling water in the first cooling water passage as a first temperature;
Second temperature detecting means for detecting the temperature of the cooling water in the second cooling water passage as a second temperature;
A first valve that is provided between the water jacket of the first cooling water passage and the merging portion, and opens and closes the first cooling water passage;
A second valve for opening and closing the third cooling water passage;
A fourth cooling water passage having one end communicated with the upstream side of the first valve in the first cooling water passage and the other end communicated with the downstream side of the branch portion in the first cooling water passage;
A second cooling water pump disposed in the fourth cooling water passage and pressurizing and discharging the cooling water;
A heater core disposed in the fourth cooling water passage and performing heat exchange with the cooling water;
Control means for controlling the first valve, the second valve, the first cooling water pump, and the second cooling water pump based on the first temperature and / or the second temperature. ,
When the second temperature is equal to or lower than a predetermined warm-up completion determination temperature, the control means fully closes the second valve and drives the second cooling water pump according to a heating request state. When the second temperature is equal to or lower than the warm-up completion determination temperature and equal to or higher than the first temperature, the first valve is fully closed, and the second temperature is equal to or lower than the warm-up completion determination temperature. When the temperature is lower than the first temperature, the first valve is driven to the valve opening side according to a temperature difference between the second temperature and the first temperature. One end is communicated with the upstream side of the radiator in the third cooling water passage, and the other end is communicated between the second valve and the first cooling water pump in the third cooling water passage to bypass the radiator. A bypass passage,
A third valve for opening and closing the bypass passage,
The control means fully closes the second valve when the second temperature is higher than the warm-up completion determination temperature and is equal to or lower than a predetermined external heat dissipation determination temperature set in advance. 2. The engine cooling device according to claim 1, wherein the first cooling water pump is driven so that the three valves are fully opened and the discharge amount is adjusted according to the second temperature.   When the second temperature is higher than the external heat dissipation determination temperature, the control means fully opens the first valve, fully opens the second valve, fully closes the third valve, and The engine cooling device according to claim 1 or 2, wherein one cooling water pump is driven.   When the second temperature is higher than the external heat radiation determination temperature, the control means varies the discharge amount of the first cooling water pump based on the second temperature and the engine load. The engine cooling device according to claim 3.   When the second temperature is higher than the external heat radiation determination temperature and the engine is operating at a high load, the control means drives the first cooling water pump at a maximum discharge amount and also controls the second cooling. 5. The engine cooling apparatus according to claim 4, wherein the water pump is driven at a maximum discharge amount regardless of a heating request state.   The engine cooling device according to any one of claims 1 to 5, wherein the control means stops driving the second cooling water pump when there is no heating request.   The engine cooling according to any one of claims 1 to 6, further comprising a heat source interposed in the fourth cooling water passage and configured to raise the temperature of the cooling water flowing through the fourth cooling water passage. apparatus. The engine cooling device according to any one of claims 1 to 7, wherein the fourth cooling water passage is formed so as to pass in the vicinity of an exhaust port formed in the cylinder head.

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