JP2002188443A - Cooling device for internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a device which optimally maintains cooling performance for an internal combustion engine and the performance of the heat radiation and heating of a radiator. SOLUTION: There are provided a pump 4 with a variable discharging quantity of the cooling water for a water jacket 2 or a radiator 6 of water-cooled internal combustion engine 1, a first cooling water passage A circulating the cooling water into the water jacket 2 by the driving of the pump 4, a second water passage B circulating the cooling water into the radiator by the driving of the pump 4, a changeover device 5 arranged between the internal combustion engine and the outlet port of the pump 4, a sensor of the external air temperature 7 and sensors of cooling water temperature 8, 10 and the external air temperature is detected with the sensor of the external air 7, as well as the cooling water temperature, is detected with the sensors of the cooling water temperature 8, 10. A controller 9 drives the passage changing device 5, based on the information from the sensors of the cooling water temperature 8, 10 and the sensor of the external air temperature 7, so as to change the passage to control the discharge quantity of the pump 4.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cooling system for an internal combustion engine, and more particularly to a cooling system for maintaining a cooling performance and a radiator performance of a water-cooled internal combustion engine at an optimum level.

[0002]

2. Description of the Related Art Conventionally, a water-cooled engine for cooling an internal combustion engine (hereinafter referred to as an engine) by water cooling has been known. To cool the water-cooled engine, a method of circulating cooling water through a cooling water passage (water jacket) inside the engine by a water pump is used.
For example, Japanese Patent Application Laid-Open No. 8-14043 discloses a water pump that circulates cooling water to the inside of an engine and a radiator and a water temperature sensor that detects the temperature of cooling water near a cooling water outlet through which cooling water flows into the engine. There is disclosed a method in which the water pump is stopped or rotated at a high speed depending on the temperature detected by the water temperature sensor.

Japanese Patent No. 25554937 discloses a water pump for circulating cooling water in a water jacket of an engine, and a bypass valve for flowing the cooling water to an engine bypass passage. A method of controlling the amount of circulation to the engine by opening and closing by the water temperature of the engine is disclosed.

In the apparatus disclosed in this publication, a thermostat valve is disposed between a radiator outlet and a water jacket inlet, and when the temperature of the engine cooling water is high, the thermostat valve circulates the radiator through the thermostat valve. Is bypassed. In addition, the outside air temperature is detected by the outside air temperature sensor, and the engine cooling water temperature is detected by the water temperature sensor.When the outside air temperature is low and the engine cooling water temperature is low, the bypass valve is opened to reduce the circulation amount and the combustion chamber wall temperature is reduced. To raise. Then, when the engine cooling water temperature rises due to warm-up, the bypass valve is closed, the amount of cooling water that bypasses the engine is increased by the bypass valve, and the amount of heat recovered by the cooling water from the combustion chamber is increased. A method is disclosed in which the amount of circulating cooling water in a heater core is ensured to improve heater performance.

[0005]

Generally, the temperature of the cooling water (water temperature) depends on the amount of heat generated from the engine and the amount of heat radiated from the radiator, and greatly affects the heat exchange due to the amount of cooling water circulation of the engine and the radiator. Dependent.

Although the flow rate of the water pump for circulating the cooling water can be controlled by the former prior art, the circulation amount of the cooling water flowing to the engine and the radiator is controlled in consideration of the heat generation of the engine and the heat radiation from the radiator. It cannot be controlled optimally. Furthermore, depending on the driving conditions of the vehicle, the radiator is affected by the traveling wind and the like, and it is difficult to settle down to the water temperature to be set (overshoot and undershoot exist).

In other words, the inability to set the optimum water temperature for the engine is a cause that the warming-up promoting effect cannot be sufficiently obtained, and the heater performance of the cooling device having the heater function is reduced, thereby deteriorating the fuel efficiency. Become.

In the latter publication, switching of whether to circulate cooling water to the radiator is possible by controlling the bypass valve, but does not control the amount of circulating water on the radiator side.
Therefore, the amount of heat radiation from the radiator is not considered. Further, since the water pump cannot be driven to supply an optimal flow rate to each of the engine and the radiator, it is necessary to increase the size of the radiator in order to secure the cooling performance at low temperature and high temperature. Further, if the water pump is constantly driven, and control is performed to improve the engine cooling performance and the heater performance by switching the bypass valve, unnecessary driving occurs and wasteful electric energy is consumed. It causes fuel economy to deteriorate.

SUMMARY OF THE INVENTION Accordingly, the present invention has been made in view of the above problems, and has as its object to provide a device which keeps the cooling performance for an internal combustion engine, the radiation of a radiator, and the heater performance optimal.
Improving fuel economy is a technical issue.

[0010]

The technical measures taken to solve the above-mentioned problems include a pump in which the discharge amount of cooling water is variable with respect to a water jacket or a radiator of a water-cooled internal combustion engine, A cooling water passage that circulates cooling water through the water jacket by driving the cooling water passage, and a second cooling water passage that circulates cooling water through the radiator by driving the pump. Flow path switching means for switching a flowing direction of cooling water flowing through the first cooling water passage and the second cooling water passage, an outside air temperature detecting means for detecting an outside air temperature, and a cooling water temperature detecting means for detecting a temperature of the cooling water; Control means for controlling the discharge amount of the pump by switching the path by driving the flow path switching means based on information from the cooling water temperature detection means and the outside air temperature detection means. It is that it was.

According to this, the outside air temperature is detected by the outside air temperature detecting means, the temperature of the cooling water is detected by the cooling water temperature detecting means, and the control means is controlled based on the information from the cooling water temperature detecting means and the outside air temperature detecting means. The direction of the cooling water flowing through the first cooling water passage and the second cooling water passage is switched by the flow path switching means, and the discharge amount of the pump can be controlled. Therefore, the first cooling water is circulated through the water jacket.
The cooling water flowing through the cooling water passage and the second cooling water passage that circulates the cooling water passage through the radiator is supplied to the internal combustion engine and the radiator by operating the flow path switching means to vary the discharge amount of the pump. It is possible to perform optimal control. In this case, wasteful energy consumption of constantly driving the water pump is eliminated, and fuel efficiency is improved.

In this case, if the heater means is provided in the first cooling water passage, the cooling water flowing through the first cooling water passage flows optimally also to the heater means, and the heater performance is improved.

Further, the cooling water temperature detecting means is provided in the first cooling water passage and the second cooling water passage, so that the cooling water flowing through the first cooling water passage and the second cooling water passage can receive information from the cooling water temperature detecting means. Depending on the engine and radiator,
More optimal control.

[0014]

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing a cooling water circulation system, showing a configuration of an embodiment of a cooling device for a water-cooled internal combustion engine (hereinafter referred to as an engine) in a vehicle. In FIG. 1, a water jacket 2 in which cooling water flows around the combustion chamber of each cylinder of the engine 1 is provided inside the engine. By circulating cooling water in the cooling water passage A by a water pump 4 provided on the inlet 2a side of the water jacket 2, the wall temperature of the engine combustion chamber can be cooled.

The cooling water passage A is provided with a flow path switching device 5 described later, a water jacket 2 provided around a combustion chamber of the engine 1, and a heater serving as a hot air source for sending warm air into the vehicle compartment from the water pump 4. This is a path which flows through the heater core (also referred to as heater core) 3 and circulates back to the water pump 4 again. The heater 3 may be provided in parallel with the cooling water passage A. The cooling water passage B is a path through which the cooling water flows from the water pump 4 through the flow path switching device 5, flows to the radiator 6 that radiates the cooling water, and returns to the water pump 4. The cooling water passage A serves as a circulation passage on the engine side, the cooling water passage B serves as a circulation passage on the radiator side, and the cooling water flowing through the radiator 6 on the water pump suction side 4b flows through the heater 3. It is configured to merge with the cooling water and flow into the suction side 4b of the water pump 4. In this configuration, a cooling water temperature sensor 10 is provided at a position where the cooling water joins, and a cooling water temperature sensor 8 which detects the temperature of the cooling water flowing out of the engine to the outlet 2b of the water jacket 2 in the cooling water passage A. Is provided.

In the present embodiment, the cooling water temperature sensor is ideally provided at the downstream outlet of the water jacket 2 of the engine 1 and at the suction side 4b of the water pump 4, but is detected by the cooling water temperature sensor 10. The water temperature at the outlet of the radiator is controlled by the engine control device 9 by information from the cooling water temperature sensor 8 and the outside air temperature sensor,
Can be estimated based on the driving state of the vehicle, the operation state of the flow path switching device 5, the running conditions of the vehicle, and the like. Therefore, when the cost is reduced and the number of parts is reduced, it can be eliminated. However, as shown in FIG. 1, if the cooling water temperature sensor 10 is used to detect the temperature of the radiator side outlet in addition to the cooling water temperature sensor 8, the engine cooling effect, the radiator heat radiation effect, and the heater performance can be improved more optimally. It is possible to control the flow of the cooling water for the purpose.

Referring back to FIG. 1, a water pump 4 is provided at the inlet 2a of the water jacket 2.
A flow path switching device 5 that creates a path for flowing cooling water from the discharge port 4 a of the water pump 4 to the radiator 6 is provided. The flow path switching device 5 is connected to the discharge port 4 of the water pump 4.
It functions so as to distribute and flow the cooling water from a to the engine side or the radiator side. This flow path switching device 5
For example, as schematically shown in FIG. 3, (a) the plunger 5 (not shown) receives an electric drive signal from the external control device 9.
1 is supplied to the operating coil, and the plunger is driven to linearly distribute the flow of the cooling water from the path A serving as the suction port to the path B or C serving as the discharge port (0).
(B) Cooling from the A path serving as a suction port by supplying an electric drive signal from an external control device 9 to a coil for operating a spool valve (not shown) and driving the spool valve. A method of linearly (0 to 100%) distributing the flow of water to the B or C path serving as a discharge port, (c) giving an electric signal from an external control device 9,
By rotating the rotating member (ball member) 53 for switching the flow path, the flow of the cooling water from the A path serving as the suction port is linearly (0 to 100%) distributed to the B path or the C path serving as the discharging port. Any of the above methods can be employed.

The flow rate of the cooling water flowing through the cooling water passages A and B is adjusted by the engine control device 9 by changing the rotation speed of the water pump 4. The path through which the cooling water flows is linearly adjusted by the flow path switching device 5.
For this reason, if the water pump 4 and the flow path switching device 5 are simultaneously controlled by the engine control device 9 in combination, the respective flow rates and paths of the cooling water flowing through the cooling water passages A and B can be adjusted with high accuracy. . In this case, the final circulation flow rate flowing through the cooling water passages A and B is determined by the water pump 4, the flow path switching device 5, and the respective flow path resistances.

The water pump 4 and the flow path switching device 5 are based on information (detection signals) output from an outside air temperature sensor 7 for detecting the outside air temperature, a cooling water temperature sensor 8 on the engine side and a cooling water temperature sensor 10 on the radiator side. The engine control device 9 controls the amount and path of the cooling water flowing through the cooling water passages A and B in accordance with the operating state of the vehicle as follows.

Next, an outline of the circulation control by the engine controller 9 for circulating the cooling water to the cooling water passage A on the engine side and the cooling water passage B on the radiator side will be described below.

As an example, the outside air temperature is low (for example, 0 ° C.).
In the case where the driver needs the air conditioning heater 3 in the vehicle (when a heater operation switch (not shown) is pressed by the driver) in the vehicle or when it is determined that the heater is necessary based on information from the outside air temperature sensor, the engine is started. At the time or immediately after the start of the engine, the cooling water temperature on the engine side is low (for example, 20 ° C. or lower). For this reason, it is impossible in principle to use the heater 3. In this case, the engine control device 9 does not drive the water pump 4, and the cooling water on the engine side and the cooling water on the radiator side circulate. In this case, the temperature rise of the combustion chamber wall surface of the engine 1 is promoted. This will reduce engine friction and improve combustion. This has the effect of improving fuel efficiency by promoting warm-up, and promoting warm-up also leads to quicker rise in water temperature. However, depending on the vehicle, the cooling water on the engine side may be slightly circulated to reduce the time until the heater 3 for air conditioning can be used, so that the startup of the water temperature is more important than the improvement in fuel efficiency. It is possible.

When the outside air temperature is low (10 ° C. or less),
If the temperature of the cooling water on the engine side is not sufficiently high (for example, 50 ° C.) while the engine is warming up, it can be considered that the vehicle needs to use the heater 3 for air conditioning. In this case, the cooling water temperature sensor 8 detects the change of the water temperature and effectively absorbs the heat generated by the engine into the cooling water so that the engine can be warmed up to the extent that the engine is not cooled more than necessary while ensuring the heater performance. I do. Along with this, it is desired to control the circulation of cooling water on the engine side, which is larger than the reference amount, so that the water temperature can be quickly raised. Here, it is assumed that there is no circulation of the cooling water on the radiator side. Here, the reference amount refers to a state in which the cooling water is not circulated to the radiator 6 when the water temperature is low, and a state in which the cooling water is circulated by the normal driving of the water pump 4 on the engine side.

When the outside air temperature is low and the cooling water temperature on the engine side is an appropriate temperature (for example, 80 to 90 ° C.) or higher, the cooling water circulation on the engine side and the radiator side requires a reference amount. Since cooling by the traveling wind can be expected depending on the driving state of the vehicle, a smaller amount of cooling water is circulated than in the past so as not to cool the engine more than necessary. Under this condition, the heat generation of the engine 1 and the state of heat radiation from the radiator 6 are monitored by the detection signals from the cooling water temperature sensors 8 and 10 so as to prevent the cooling water from being excessively cooled, and the cooling water passages A and B are respectively controlled. As a result, the temperature of the cooling water is controlled to an appropriate temperature, and there is no problem in using the heater 3 for air conditioning.

The outside air temperature is not very low (for example,
30 ° C.), when the heater 3 for air conditioning is not required, the temperature of the cooling water on the engine side is an appropriate temperature during warm-up from the start of the engine.
If the temperature is lower than (80 to 90 ° C.), the cooling water of the engine and the radiator are not circulated. In this case, depending on the vehicle, the cooling water on the engine side may be slightly circulated. As a result, it is possible to promote an increase in the temperature of the wall surface of the engine combustion chamber, thereby reducing engine friction and improving combustion. This has the effect of improving fuel efficiency by promoting warm-up, and also leads to quicker rise of water temperature.

The outside air temperature is not very low (15-30
℃), when the cooling water temperature of the engine side is at an appropriate temperature (80-88 ℃), circulation of the cooling water on the engine side and the radiator side is necessary, but cooling by the traveling wind is expected depending on the driving condition of the vehicle. Therefore, the circulation amount of the cooling water can be reduced as compared with the conventional case. Under this condition, a little more cooling water is required to flow through the cooling water passage than when the outside air temperature is low (0 ° C. or less), and the detection signals output from the cooling water temperature sensors 8 and 10 generate heat from the engine 1 and the radiator 6. Is monitored by the engine control device 9 and the cooling water passages A and B are controlled to control the cooling water temperature to an appropriate temperature.

On the other hand, idling after high-load running when the outside air temperature is high (for example, 30 ° C. or higher) and the cooling water temperature on the engine side is higher than appropriate temperature (for example, 95 ° C.) In the case of restarting operation, circulation of cooling water is required on the engine side and the radiator side. Under this state, traveling wind cooling due to the operating state of the vehicle cannot be expected, and it is desirable to improve the heat radiation performance as compared with the conventional one so as not to increase the cooling water temperature more than necessary. Under this condition, by supplying a large amount of water that could not be supplied by the conventional water pump 4, the radiation performance of the radiator 6 can be improved, so that the radiator size can be made smaller than before. Further, a cooling fan 11 for radiator cooling is provided.
It can be expected that the noise can be reduced by reducing the size or the operating time of the cooling fan, and the effect of improving the fuel efficiency by reducing the operating energy of the cooling fan 11 can be expected. As long as the engine 1 is not overheated, the circulation of the cooling water in the cooling water passage A on the engine side is smaller than that in the related art (for example, a system using a water pump that operates with the rotation of the engine as described in the related art). Can be reduced.

Furthermore, in the case of a dead soak in which the outside temperature is high and the engine 1 is stopped, the cooling water temperature is high (for example, 10
In the conventional system, the operation of the water pump 4 has to be stopped in the conventional system, which causes problems such as local overheating and cooling water reduction. In the system configuration, by circulating the cooling water on the engine side and the radiator side a little,
These problems can be solved.

As another embodiment, as shown in FIG. 2, even if the flow path switching device 5 is provided not on the discharge port of the water pump 4 but on the suction side 4, the same effect as described above can be obtained. Can be.

As described above, by adopting the above-described configuration, the driving loss of the water pump 4 can be reduced while the cooling water temperature control optimal for the engine 1 is performed.
To improve fuel efficiency by promoting warm-up, improve comfort by securing heater performance, and reduce the size of the radiator.
Further, noise reduction and fuel efficiency improvement by shortening the fan operation of the cooling fan 11 are improved.

[0031]

According to the present invention, the outside air temperature is detected by the outside air temperature detecting means, the temperature of the cooling water is detected by the cooling water temperature detecting means, and the control is performed based on the information from the cooling water temperature detecting means and the outside air temperature detecting means. The means switches the flow direction of the cooling water flowing through the first cooling water passage and the second cooling water passage by the flow path switching means. Since the discharge amount of the pump is controlled, the first cooling means circulates the cooling water through the water jacket. The cooling water flowing through the water passage and the second cooling water passage that circulates the cooling water passage through the radiator is optimized for the internal combustion engine and the radiator by activating the flow switching means and varying the discharge amount of the pump. Can be controlled. In this case, wasteful energy consumption of constantly driving the water pump is eliminated, and fuel efficiency is improved.

In this case, if the heater means is provided in the first cooling water passage, the cooling water flowing through the first cooling water passage flows optimally also to the heater means, and the heater performance is improved.

Also, the cooling water temperature detecting means is provided in the first cooling water passage and the second cooling water passage, so that the cooling water flowing through the first cooling water passage and the second cooling water passage can receive information from the cooling water temperature detecting means. Can be controlled more optimally.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of a cooling device for an internal combustion engine according to an embodiment of the present invention.

FIG. 2 is a block diagram illustrating a configuration of a cooling device for an internal combustion engine according to another embodiment of the present invention.

FIG. 3 is an explanatory view schematically showing the configuration of the flow path switching device shown in FIGS. 1 and 2.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Engine (internal combustion engine) 2 Water jacket 3 Heater (heater means) 4 Water pump (pump) 5 Flow path switching device (flow path switching means) 6 Radiator 7 Outside air temperature sensor (outside air temperature detection means) 8, 10 Cooling water temperature sensor (Cooling water temperature detection means) 9 Engine control device (control means) A Cooling water passage (first cooling water passage) B Cooling water passage (second cooling water passage)

Claims (3)

[Claims] 1. A pump in which a discharge amount of cooling water is variable with respect to a water jacket or a radiator of a water-cooled internal combustion engine, a first cooling water passage for circulating cooling water through the water jacket by driving the pump, A cooling device for an internal combustion engine, comprising: a second cooling water passage that circulates cooling water through the radiator by driving the pump; wherein a flow direction of the cooling water flowing through the first cooling water passage and the second cooling water passage is changed. Flow path switching means for switching, outside air temperature detecting means for detecting outside air temperature, cooling water temperature detecting means for detecting the temperature of cooling water, and the flow rate based on information from the cooling water temperature detecting means and the outside air temperature detecting means. Control means for driving a path switching means to switch a path to control a discharge amount of the pump. 2. The cooling device for an internal combustion engine according to claim 1, wherein a heater is provided in the first cooling water passage. 3. The cooling device for an internal combustion engine according to claim 1, wherein said cooling water temperature detecting means is provided in said first cooling water passage and said second cooling water passage.