JP2012052503A - Cooling device of water-cooled internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a cooling device of a water-cooled internal combustion engine capable of reducing wasteful power consumption by maintaining the temperature of cooling water in an appropriate range to improve the fuel consumption rate by controlling the drive of an electric water pump and an electric cooling fan by taking into consideration the drive state of the water-cooled internal combustion engine and the heat radiation property of a heat exchanger.SOLUTION: The cooling device includes an electric water pump 18 configured to circulate cooling water through a cooling water channel provided in a water-cooled internal combustion engine 2, a heat exchanger 13 configured to radiate heat of the cooling water, an electric cooling fan 19 configured to send air to the heat exchanger 13, a cooling water temperature sensor 16 configured to detect the temperature of cooling water within the water-cooled internal combustion engine 2, a drive state detecting unit configured to detect the drive state of the water-cooled internal combustion engine 2, and a control device 21 configured to calculate an amount of heat requested to be radiated required by the heat exchanger 13 based on the temperature of cooling water and the drive state and to control the rotating speed of the electric water pump 18 and the electric cooling fan 19 based on the amount of heat requested to be radiated and the heat radiation property of the heat exchanger 13 when the temperature of cooling water is higher than a predetermined temperature.

Description

  The present invention relates to an electric water pump that circulates cooling water between a water-cooled internal combustion engine and a heat exchanger, and a cooling device for a water-cooled internal combustion engine that includes an electric cooling fan that blows air to the heat exchanger.

  Conventionally, as a cooling device for a water-cooled internal combustion engine, cooling water is circulated between the water-cooled internal combustion engine and the heat exchanger by a mechanical water pump using the driving force of the water-cooled internal combustion engine and cooled by the heat exchanger. Those that dissipate water are generally known.

  However, since the mechanical water pump is driven in synchronism with the rotation of the water-cooled internal combustion engine, for example, when the vehicle is traveling at a high speed, an excessive flow of cooling water circulates and the power loss of the water-cooled internal combustion engine increases. There was a problem that fuel consumption deteriorated. In addition, since the mechanical water pump is driven in synchronization with the rotation of the water-cooled internal combustion engine, there is a problem that it is difficult to control the cooling water temperature within an appropriate range.

  In order to solve the above problems, an electric water pump in which an electric motor is attached to the water pump has been recently proposed. In a cooling system for a water-cooled internal combustion engine using an electric water pump, the number of revolutions of the electric water pump can be controlled regardless of the driving state of the water-cooled internal combustion engine. It can be adjusted to an appropriate range.

  As a cooling device for a water-cooled internal combustion engine using such an electric water pump, the following is known. That is, in the conventional cooling device for a water-cooled internal combustion engine, the control device determines that the state of the coolant flowing in the heat exchanger is in a laminar flow area when the coolant temperature in the water-cooled internal combustion engine is equal to or higher than a predetermined target temperature. The rotational speed of the electric water pump is controlled so as to fall within the transition region between the turbulent region and the turbulent region close to the transition region. Further, the control device controls the rotation speeds of the electric water pump and the electric cooling fan so that the power consumption of the electric water pump and the electric cooling fan necessary for obtaining a predetermined heat radiation amount by the heat exchanger is minimized. (For example, refer to Patent Document 1).

  In another conventional cooling apparatus for a water-cooled internal combustion engine, the control device controls the rotation speed of the electric water pump based on the target flow rate obtained from the rotation speed and the output torque of the water-cooled internal combustion engine, and also performs cooling. The driving of the electric cooling fan is controlled based on the water temperature. Further, when the coolant temperature is higher than the drive temperature at which the drive of the electric cooling fan is started, the control device corrects the number of rotations of the electric water pump to be increased according to the increase in the coolant temperature (for example, Patent Documents). 2).

JP 2002-332842 A JP 2008-215094 A

However, the prior art has the following problems.
In the cooling device for a water-cooled internal combustion engine disclosed in Patent Document 1, the control device does not consider the driving state of the water-cooled internal combustion engine, and based only on the coolant temperature in the water-cooled internal combustion engine, The number of rotations of the electric cooling fan is controlled.

  Here, if the driving state of the water-cooled internal combustion engine is not taken into account, it is not clear how the current driving state will change in the future, and it may be difficult to maintain the cooling water temperature in an appropriate range. There is. For this reason, there is a problem that the friction (power loss) of the water-cooled internal combustion engine increases and fuel consumption deteriorates.

  Further, in the cooling device for a water-cooled internal combustion engine disclosed in Patent Document 2, the control device does not consider the heat dissipation performance of the heat exchanger, and based only on the coolant temperature in the water-cooled internal combustion engine, the electric water pump The number of revolutions is increased and corrected.

  Here, in the heat exchanger, when the air volume is constant, even if the flow rate of the cooling water flowing in the heat exchanger is increased, there is a maximum heat radiation amount that saturates the heat radiation amount. Further, when the heat dissipation performance of the heat exchanger is not taken into account, there is a possibility that the rotational speed of the electric water pump is corrected to increase so that an excessive flow of cooling water exceeding the heat dissipation performance of the heat exchanger circulates. Therefore, there is also a problem that the power consumption of the electric water pump increases unnecessarily.

  The present invention has been made to solve the above-described problems, and controls the driving of the electric water pump and the electric cooling fan in consideration of the driving state of the water-cooled internal combustion engine and the heat dissipation performance of the heat exchanger. Accordingly, an object of the present invention is to obtain a cooling device for a water-cooled internal combustion engine that can maintain the cooling water temperature in an appropriate range to improve fuel efficiency and reduce wasteful power consumption.

  A cooling device for a water-cooled internal combustion engine according to the present invention includes an electric water pump that circulates cooling water in a cooling water passage provided in the water-cooled internal combustion engine, a heat exchanger that radiates cooling water, and a heat exchanger. An electric cooling fan for blowing air, a cooling water temperature detecting means for detecting a cooling water temperature in the water-cooled internal combustion engine, a driving state detecting means for detecting a driving state of the water-cooled internal combustion engine, and the cooling water temperature from a predetermined temperature If it is too high, calculate the required heat dissipation required for the heat exchanger based on the cooling water temperature and the driving state, and based on the required heat dissipation and the heat dissipation performance of the heat exchanger, the electric water pump and the electric cooling fan And a control means for controlling the rotational speed.

According to the cooling apparatus for a water-cooled internal combustion engine according to the present invention, the control means includes the heat radiation required heat amount required for the heat exchanger based on the cooling water temperature and the driving state when the cooling water temperature is higher than a predetermined temperature. Is calculated, and the number of revolutions of the electric water pump and the electric cooling fan is controlled based on the required heat dissipation and the heat dissipation performance of the heat exchanger.
As a result, the drive of the electric water pump and the electric cooling fan can be appropriately controlled, and the cooling water temperature can be maintained in an appropriate range to improve the fuel efficiency, and wasteful power consumption can be reduced.

It is a block diagram which shows the cooling device of the water-cooled internal combustion engine which concerns on Embodiment 1 of this invention with a water-cooled internal combustion engine. In the cooling device for a water-cooled internal combustion engine according to Embodiment 1 of the present invention, it is an explanatory diagram showing a heat radiation performance map of a heat exchanger included in a control device. In the cooling device for a water-cooled internal combustion engine according to the first embodiment of the present invention, it is a flowchart showing a process in which the control device controls the driving of the electric water pump. In the cooling device for a water-cooled internal combustion engine according to the first embodiment of the present invention, it is a flowchart showing a process in which the control device controls the driving of the electric cooling fan.

  Hereinafter, preferred embodiments of a cooling device for a water-cooled internal combustion engine according to the present invention will be described with reference to the drawings. In the drawings, the same or corresponding parts will be described with the same reference numerals. In the following embodiments, the case where the cooling device for the water-cooled internal combustion engine is mounted on a vehicle will be described. However, the present invention is not limited to this, and the cooling device for the water-cooled internal combustion engine includes a water-cooled internal combustion engine. As long as the mobile body is provided, it may be mounted on another vehicle or the like.

Embodiment 1 FIG.
FIG. 1 is a configuration diagram showing a cooling apparatus 1 for a water-cooled internal combustion engine according to Embodiment 1 of the present invention, together with a water-cooled internal combustion engine 2. In FIG. 1, in the water-cooled internal combustion engine 2, air that is sucked from an air intake (not shown) and from which dust and the like are removed by an air cleaner is supplied to each cylinder from the intake manifold. The air supplied to each cylinder is mixed with the fuel injected from the injector in the cylinder to become an air-fuel mixture, and burned by ignition of the spark plug.

  Subsequently, the piston in the cylinder is reciprocated by the expansion force generated by the combustion of the air-fuel mixture, and the reciprocating motion of the piston is converted into the rotational motion of the crankshaft. The rotational movement of the crankshaft is transmitted to the wheels via a transmission or the like, and becomes a driving force for the vehicle. At this time, if the cylinder of the water-cooled internal combustion engine 2 becomes high temperature due to the combustion of the air-fuel mixture, knocking or the like may occur. In order to cool the cylinder of the water-cooled internal combustion engine 2, a cooling device 1 for the water-cooled internal combustion engine is provided.

  A cooling device 1 for a water-cooled internal combustion engine includes a water jacket 11, a first cooling water channel 12, a heat exchanger 13, a second cooling water channel 14, a bypass water channel 15, a cooling water temperature sensor 16 (cooling water temperature detecting means), a thermostat 17, An electric water pump 18, an electric cooling fan 19, an outside air temperature sensor 20 (outside air temperature detecting means) and a control device 21 (control means) are included. Here, the insides of the water jacket 11, the first cooling water channel 12, the heat exchanger 13, the second cooling water channel 14, and the bypass water channel 15 are filled with cooling water.

  The water jacket 11 is a cooling water channel provided around the cylinder of the water-cooled internal combustion engine 2. The water jacket 11 cools the cylinder which became high temperature by combustion with the cooling water which flows through the inside.

  The first cooling water channel 12 is provided so as to connect the outlet of the water jacket 11 and the inlet of the heat exchanger 13. The second cooling water channel 14 is provided so as to connect the outlet of the heat exchanger 13 and the inlet of the water jacket 11.

  The heat exchanger 13 is a radiator, is heated by flowing through the water jacket 11, and cools the cooling water that has flowed in through the first cooling water passage 12 by heat exchange to cool the second cooling water passage 14. To the water jacket 11. The amount of heat released from the heat exchanger 13 is determined by the ambient temperature around the heat exchanger 13 (in the engine room), the amount of air passing through the heat exchanger 13, and the flow rate of cooling water flowing through the heat exchanger 13.

  The bypass water channel 15 is provided to connect the first cooling water channel 12 and the second cooling water channel 14 so as to bypass the heat exchanger 13. For example, when the cooling water temperature is too low, the friction (power loss) of the water-cooled internal combustion engine 2 increases and the fuel consumption deteriorates. Therefore, in such a case, the cooling water is circulated through the bypass water channel 15 without flowing the cooling water in the heat exchanger 13, thereby reducing the cooling water temperature and driving loss of the electric water pump 18. Can be reduced.

  The cooling water temperature sensor 16 is provided in the vicinity of the outlet of the water jacket 11 in the first cooling water channel 12. The cooling water temperature sensor 16 detects the temperature of the cooling water heated through the water jacket 11 and outputs the cooling water temperature as a signal to the control device 21.

  The thermostat 17 is provided at a connection location between the second cooling water channel 14 and the bypass water channel 15. The thermostat 17 opens and closes a valve provided inside according to the temperature of the cooling water flowing through the thermostat 17, and flows through the cooling water circulation path through the heat exchanger 13 or the bypass water path 15 (the heat exchanger 13 Switch to a route that does not flow.

  Specifically, when the cooling water temperature is less than a predetermined value, the valve inside the thermostat 17 is closed, the communication between the heat exchanger 13 and the second cooling water channel 14 is blocked, and the bypass water channel 15 The 2nd cooling water channel 14 is connected. Thereby, the cooling water that has flowed out from the water jacket 11 to the first cooling water passage 12 bypasses the heat exchanger 13 and flows into the water jacket 11 again. Due to such circulation of the cooling water, the cooling water is gradually warmed and the warm-up of the water-cooled internal combustion engine 2 is promoted.

  On the other hand, when the cooling water temperature is equal to or higher than a predetermined value, the valve inside the thermostat 17 is opened to cut off the communication between the bypass water passage 15 and the second cooling water passage 14 and the heat exchanger 13 and the second cooling water. The water channel 14 is communicated. As a result, the cooling water flowing out from the water jacket 11 to the first cooling water passage 12 flows into the heat exchanger 13 and is cooled, and then flows out to the water jacket 11 through the second cooling water passage 14. The cylinder of the water-cooled internal combustion engine 2 is cooled by the circulation of the cooling water.

  The electric water pump 18 is provided at the inlet of the water jacket 11 in the second cooling water channel 14. The electric water pump 18 includes an electric motor and an impeller, and circulates cooling water between the water-cooled internal combustion engine 2 and the heat exchanger 13. Further, the electric water pump 18 is controlled by the drive command from the control device 21 so that the rotation speed of the impeller is controlled and the flow rate of the circulating cooling water is controlled. The electric water pump 18 is supplied with electric power from a battery mounted on the vehicle.

  The electric cooling fan 19 is provided on the back surface of the heat exchanger 13. The electric cooling fan 19 is constituted by an electric motor and an impeller, and cools the heat exchanger 13 by sending air to the heat exchanger 13. In addition, the electric cooling fan 19 is controlled by the drive command from the control device 21 to control the rotation speed of the impeller, and the amount of air passing through the heat exchanger 13 is controlled. The electric cooling fan 19 is supplied with electric power from a battery mounted on the vehicle.

  The outside air temperature sensor 20 is provided in the vicinity of the heat exchanger 13 installed in the engine room. The outside air temperature sensor 20 detects the ambient temperature around the heat exchanger 13 and outputs the ambient temperature to the control device 21 as a signal.

  When the coolant temperature detected by the coolant temperature sensor 16 is higher than the warm-up temperature (predetermined temperature), the control device 21 controls the heat exchanger 13 based on the coolant temperature and the driving state of the water-cooled internal combustion engine 2. Calculate the required heat dissipation heat quantity. Further, the control device 21 rotates the rotational speeds of the electric water pump 18 and the electric cooling fan 19 in order to control the cooling water temperature within an appropriate range based on the calculated heat radiation required heat amount and the heat radiation performance of the heat exchanger 13. To control.

  Here, the control device 21 includes a microprocessor (not shown) having a CPU and a memory storing a program, and each function of the control device 21 is stored in the memory as software. Note that the control device 21 may use an engine control unit of the vehicle in order to easily obtain the driving state of the water-cooled internal combustion engine 2.

  Specifically, the control device 21 has a plurality of maps of the heat dissipation performance of the heat exchanger 13 according to the amount of air passing through the heat exchanger 13, and is calculated when the coolant temperature is higher than the warm-up temperature. The rotational speeds of the electric water pump 18 and the electric cooling fan 19 are controlled based on the required heat dissipation heat amount and the heat dissipation performance map selected according to the airflow passing through the heat exchanger 13. Thereby, since a cooling water temperature can be hold | maintained in an appropriate range, a fuel consumption can be improved. In addition, when the coolant temperature is equal to or lower than the warm-up temperature, the control device 21 controls the rotational speed of the electric water pump 18 to a low speed to promote warm-up of the water-cooled internal combustion engine 2.

  Here, the control device 21 calculates the required heat radiation amount required for the heat exchanger 13 based on the coolant temperature detected by the coolant temperature sensor 16 and the rotational speed and output torque of the water-cooled internal combustion engine 2. To do. At this time, the rotational speed of the water-cooled internal combustion engine 2 is obtained from, for example, a crank angle sensor (driving state detecting means) that detects the rotational angle of the crankshaft. Further, the output torque of the water-cooled internal combustion engine 2 is obtained based on, for example, the intake pressure in the intake manifold and the fuel injection amount from the injector.

  Further, the control device 21 calculates the air volume passing through the heat exchanger 13 based on the vehicle speed wind and the air volume of the electric cooling fan 19 in order to select the heat dissipation performance map. At this time, the vehicle speed wind is estimated from, for example, the speed of the vehicle detected by a speed sensor attached to the wheel of the vehicle. The air volume of the electric cooling fan 19 is estimated from the rotational speed of the impeller of the electric cooling fan 19.

  Further, the control device 21 corrects the heat radiation amount in the heat radiation performance map of the heat exchanger 13 based on the ambient temperature detected by the outside air temperature sensor 20. That is, when the ambient temperature is low, the control device 21 corrects the amount of heat radiated from the heat exchanger 13 so as to increase. When the ambient temperature is high, the control device 21 decreases the heat dissipation performance of the heat exchanger 13. to correct. Thereby, since the exact heat dissipation performance of the heat exchanger 13 can be obtained, the power consumption of the electric water pump 18 can be reduced. Note that the control device 21 may estimate the ambient temperature around the heat exchanger 13 from the temperature outside the vehicle.

  Further, the control device 21 determines the number of rotations of the electric water pump 18 corresponding to the maximum heat radiation heat amount at which the heat radiation heat is saturated in the heat radiation performance map selected according to the air volume passing through the heat exchanger 13. The upper limit number of rotations. Thereby, since the cooling water of the excess flow volume exceeding the heat dissipation performance of the heat exchanger 13 can be suppressed, the power consumption of the electric water pump 18 can be reduced.

  The control device 21 also has the electric cooling fan 19 so as to satisfy the required heat dissipation amount when the required heat dissipation amount is larger than the maximum heat dissipation amount in the heat dissipation performance of the heat exchanger 13 and the required heat dissipation amount is larger than the predetermined heat amount. To increase the amount of heat radiated from the heat exchanger 13. Thereby, the overheating at the time of the high load low speed driving | running | working in which the heat dissipation performance of the heat exchanger 13 will be in a low state can be suppressed. In addition, it is possible to suppress excessive driving of the electric cooling fan 19 during low-load high-speed traveling where the heat dissipation performance of the heat exchanger 13 is high, and to reduce the power consumption of the electric cooling fan 19.

  Here, a heat dissipation performance map of the heat exchanger 13 will be described with reference to FIG. FIG. 2 is an explanatory diagram showing a heat dissipation performance map of the heat exchanger 13 included in the control device 21 in the cooling apparatus for a water-cooled internal combustion engine according to Embodiment 1 of the present invention. The control device 21 has a plurality of heat dissipation performance maps for each air volume passing through the heat exchanger 13. Further, the heat radiation amount in the heat radiation performance map is corrected based on the ambient temperature detected by the outside air temperature sensor 20.

  In FIG. 2, the horizontal axis indicates the amount of heat dissipated by the heat exchanger 13, and the vertical axis indicates the rotational speed of the electric water pump 18. When the required heat dissipation amount is high, the rotational speed of the electric water pump 18 is inevitably high, but the heat dissipation amount is saturated at a certain value due to the limit of the heat dissipation performance. Therefore, if the heat dissipation performance is not taken into account, the number of rotations of the electric water pump 18 becomes excessive, and wasteful power is consumed. Therefore, the control device 21 sets the maximum radiated heat amount in a range in which the radiated heat amount rises linearly as the maximum radiated heat amount Qmax, and sets the rotation speed of the electric water pump 18 at this time as the rotation upper limit value Rwmax.

3 and 4, in the cooling device 1 for a water-cooled internal combustion engine according to the first embodiment of the present invention, the control device 21 controls the driving of the electric water pump 18 and the electric cooling fan 19. The processing to be performed will be described in detail.
First, a process in which the control device 21 controls the driving of the electric water pump 18 will be described with reference to FIG.

First, the control device 21 calculates the required heat dissipation amount Qr based on the rotational speed NE and output torque N of the water-cooled internal combustion engine 2 and the coolant temperature T detected by the coolant temperature sensor 16 (step S1). .
Subsequently, the control device 21 calculates the air volume V passing through the heat exchanger 13 in order to select the heat dissipation performance map of the heat exchanger 13 (step S2).

Next, the control device 21 corrects the heat radiation amount in the heat radiation performance map of the heat exchanger 13 based on the ambient temperature To detected by the outside air temperature sensor 20 (step S3).
Subsequently, the control device 21 sets the rotation upper limit value Rwmax of the electric water pump 18 from the heat dissipation performance map of the heat exchanger 13 at the air volume V passing through the heat exchanger 13 (step S4).

  Next, the control device 21 determines whether or not the cooling water temperature T is higher than the warm-up temperature Tw (step S5).

When it is determined in step S5 that the cooling water temperature T is equal to or lower than the warm-up temperature Tw (that is, No), the control device 21 determines that the water-cooled internal combustion engine 2 needs to be warmed up, The rotation speed Rw of the electric water pump 18 is set to Rwmin, which is a low rotation (step S6).
Subsequently, the control device 21 drives the electric water pump 18 at the set rotation speed Rw (step S7), and ends the process of FIG.

  On the other hand, when it is determined in step S5 that the cooling water temperature T is higher than the warm-up temperature Tw (that is, Yes), the control device 21 needs to dissipate the cooling water in the heat exchanger 13. From the heat dissipation performance map of the heat exchanger 13, the rotational speed Rw of the electric water pump 18 corresponding to the heat dissipation required heat quantity Qr is set (step S8).

  Next, the control device 21 determines whether or not the rotational speed Rw of the electric water pump 18 set in step S8 circulates an excessive amount of cooling water exceeding the heat dissipation performance of the heat exchanger 13. Then, it is determined whether or not the rotation speed Rw is equal to or less than the rotation upper limit value Rwmax (step S9).

  In step S9, when it is determined that the rotation speed Rw of the electric water pump 18 is equal to or less than the rotation upper limit value Rwmax (that is, Yes), the control device 21 determines the flow rate of the cooling water flowing in the heat exchanger 13. It is determined that the electric water pump 18 is appropriate, and the electric water pump 18 is driven at the set rotational speed Rw (step S7), and the process of FIG.

On the other hand, if it is determined in step S9 that the rotational speed Rw of the electric water pump 18 is greater than the rotation upper limit value Rwmax (that is, No), the control device 21 is an electric motor that exceeds the heat dissipation performance of the heat exchanger 13. It is determined that the rotation speed Rw of the water pump 18 is set, and the rotation speed Rw of the electric water pump 18 is set to the rotation upper limit value Rwmax (step S10).
Subsequently, the control device 21 drives the electric water pump 18 at the set rotation speed Rw (step S7), and ends the process of FIG.

  By performing the drive control of the electric water pump 18 as described above, when the cooling water temperature is low, the electric water pump 18 is driven at a low speed, so that the time required for warming up the water-cooled internal combustion engine 2 is shortened. can do. Therefore, the fuel injection amount used when the water-cooled internal combustion engine 2 warms up can be suppressed, and the fuel efficiency of the vehicle can be improved. Even if it is determined that the cooling water needs to be radiated, by setting the upper limit number of rotations of the electric water pump 18, the number of rotations of the electric water pump 18 that exceeds the heat dissipation performance of the heat exchanger 13 is set. Is suppressed, and wasteful power consumption can be reduced.

  Next, a process in which the control device 21 controls the driving of the electric cooling fan 19 will be described with reference to FIG.

First, the control device 21 calculates the heat release required heat amount Qr based on the rotational speed NE and output torque N of the water-cooled internal combustion engine 2 and the coolant temperature T detected by the coolant temperature sensor 16 (step S11). .
Subsequently, the control device 21 calculates the air volume V passing through the heat exchanger 13 in order to select the heat dissipation performance map of the heat exchanger 13 (step S12).

Next, the control device 21 corrects the heat radiation amount in the heat radiation performance map of the heat exchanger 13 based on the ambient temperature To detected by the outside air temperature sensor 20 (step S13).
Subsequently, the control device 21 sets the maximum heat radiation amount Qmax of the heat exchanger 13 from the heat radiation performance map of the heat exchanger 13 at the air volume V passing through the heat exchanger 13 (step S14).

  Next, the control device 21 determines whether or not the calculated heat release required heat amount Qr is larger than the maximum heat release heat amount Qmax (step S15).

  If it is determined in step S15 that the required heat dissipation amount Qr is equal to or less than the maximum heat dissipation amount Qmax (ie, No), the control device 21 has a sufficient heat dissipation performance of the heat exchanger 13 and the electric water pump 18 It is determined that the cooling water can be dissipated by the drive alone, the drive of the electric cooling fan 19 is stopped (step S16), and the processing of FIG.

  On the other hand, when it is determined in step S15 that the required heat dissipation amount Qr is larger than the maximum heat dissipation amount Qmax (that is, Yes), the control device 21 requires the electric cooling fan 19 to drive the required heat dissipation amount Qr. In order to determine whether the value is high, it is determined whether the required heat dissipation amount Qr is larger than the electric cooling fan drive heat amount value Qf (predetermined amount of heat) (step S17).

  If it is determined in step S17 that the required heat dissipation amount Qr is equal to or less than the electric cooling fan drive heat amount value Qf (that is, No), the control device 21 determines that there is a margin in the cooling water temperature and the like. The driving of the cooling fan 19 is stopped (step S16), and the process of FIG.

  On the other hand, if it is determined in step S17 that the required heat dissipation amount Qr is larger than the electric cooling fan drive heat amount value Qf (that is, Yes), the control device 21 drives the electric cooling fan 19 to heat exchanger. 13 is determined to be improved, the electric cooling fan 19 is driven to satisfy the required heat dissipation amount Qr (step S18), and the process of FIG.

  By performing the drive control of the electric cooling fan 19 as described above, the electric cooling fan 19 is driven according to the heat dissipation required heat amount Qr. Overheating can be suppressed. In addition, although the cooling water temperature is high but the vehicle speed is sufficient and the heat dissipation performance of the heat exchanger 13 is ensured, the drive of the electric cooling fan 19 is stopped to reduce wasteful power consumption. Can be reduced.

As described above, according to the first embodiment, when the cooling water temperature is higher than the predetermined temperature, the control unit calculates the required heat radiation amount required for the heat exchanger based on the cooling water temperature and the driving state. Then, the rotational speeds of the electric water pump and the electric cooling fan are controlled based on the required heat dissipation amount and the heat dissipation performance of the heat exchanger.
As a result, the drive of the electric water pump and the electric cooling fan can be appropriately controlled, and the cooling water temperature can be maintained in an appropriate range to improve the fuel efficiency, and wasteful power consumption can be reduced.

  DESCRIPTION OF SYMBOLS 1 Cooling device of water-cooled internal combustion engine, 2 Water-cooled internal combustion engine, 11 Water jacket, 12 1st cooling water channel, 13 Heat exchanger, 14 2nd cooling water channel, 15 Bypass water channel, 16 Cooling water temperature sensor, 17 Thermostat, 18 Electric Water pump, 19 electric cooling fan, 20 outside air temperature sensor, 21 control device.

Claims (7)

An electric water pump for circulating cooling water in a cooling water passage provided in the water-cooled internal combustion engine;
A heat exchanger that dissipates the cooling water;
An electric cooling fan for blowing air to the heat exchanger;
Cooling water temperature detecting means for detecting a cooling water temperature in the water-cooled internal combustion engine;
Drive state detection means for detecting the drive state of the water-cooled internal combustion engine;
When the cooling water temperature is higher than a predetermined temperature, a required heat dissipation amount of heat required for the heat exchanger is calculated based on the cooling water temperature and the driving state, and the required heat dissipation amount and the heat dissipation of the heat exchanger are calculated. Control means for controlling the number of rotations of the electric water pump and the electric cooling fan based on performance;
A cooling device for a water-cooled internal combustion engine, comprising: The control means has a plurality of maps of heat dissipation performance of the heat exchanger according to the amount of air passing through the heat exchanger, and the heat dissipation selected according to the amount of heat required for heat dissipation and the amount of air passing through the heat exchanger. The cooling device for a water-cooled internal combustion engine according to claim 1, wherein the number of revolutions of the electric water pump is controlled based on a performance map. The control means calculates the heat release required heat amount based on the cooling water temperature and at least the rotational speed of the water-cooled internal combustion engine and the output torque of the water-cooled internal combustion engine among the driving states. The cooling device for a water-cooled internal combustion engine according to claim 1 or 2. 2. The air flow passing through the heat exchanger is calculated based on the speed of a vehicle on which the water-cooled internal combustion engine is mounted and the rotational speed of the electric cooling fan. The cooling device for a water-cooled internal combustion engine according to any one of claims 1 to 3. It further comprises outside air temperature detecting means for detecting the ambient temperature around the heat exchanger,
The cooling device for a water-cooled internal combustion engine according to any one of claims 1 to 4, wherein the control means corrects the heat radiation performance of the heat exchanger based on the ambient temperature. . The said control means makes the rotation speed of the said electric water pump corresponding to the maximum heat radiation heat amount which the heat radiation heat | fever saturates in the heat radiation performance of the said heat exchanger the upper limit rotation speed of the said electric water pump. The cooling device for a water-cooled internal combustion engine according to any one of claims 1 to 5. The control means includes the electric cooling so as to satisfy the required heat dissipation when the required heat dissipation is greater than the maximum heat dissipation in the heat dissipation performance of the heat exchanger and the required heat dissipation is greater than a predetermined heat amount. The cooling device for a water-cooled internal combustion engine according to any one of claims 1 to 6, wherein a fan is driven.

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