JP2003286845A - Cooler for water cooled engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cooler for a water cooled engine which can enhance fuel efficiency without lowering the performance of an air conditioner even when a condition such as outside temperature changes in the water cooled engine having an oil cooler and the air conditioner. <P>SOLUTION: The water cooled engine cooler having the oil cooler for adjusting the temperature of operating oil of an automatic transmission by the heat exchange of cooling water and a water temperature detecting means for detecting the temperature of the cooling water. The water cooled engine cooler includes a switching means capable of switching the operation and the stop of the oil cooler and a switching control means for controlling the switching operation of the switching means. The switching control means outputs a command for stopping the oil cooler to the switching means when the detected water temperature is lower than a preset temperature, and outputs a command for operating the oil cooler to the switching means when the detected water temperature is higher than the preset temperature. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water-cooled engine cooling device, and more particularly to a water-cooled engine cooling device in which a pump for circulating cooling water in an engine is electrified and a control method thereof.

[0002]

2. Description of the Related Art Conventionally, as a cooling device for a water-cooled engine, a technique described in Japanese Utility Model Publication No. 4-41972 is known. In the water-cooled engine cooling device described in this publication, an oil cooler that heats and cools the hydraulic oil of the transmission by using the cooling water of the engine and an air conditioner that coordinates the air in the vehicle interior are provided. It is provided.
As a result, even when the oil temperature is low, such as after the engine is started, by heating the hydraulic oil with the oil cooler,
By ensuring proper viscosity of hydraulic oil and reducing friction loss in the automatic transmission, the fuel efficiency of the vehicle is improved.

[0003]

However, the above-mentioned prior art has the following problems. That is, in a good season such as spring or autumn, the hydraulic fluid of the automatic transmission does not significantly decrease even if the engine is stopped. Furthermore, even when the air conditioner is used, since the difference between the target temperature that is considered to be set by the passenger and the outside air temperature is small, the cooling oil is used to heat the hydraulic oil while operating the air conditioner. Even if it does, fuel efficiency can be improved. However, in an environment where the outside air temperature is very low, such as in winter, the hydraulic oil of the automatic transmission becomes extremely low due to the continuation of the engine stop state. Further, the difference between the above-mentioned target temperature and the outside temperature becomes large, so that when heating the hydraulic oil and heating the vehicle interior, the energy used for heating the hydraulic oil is large, which causes air conditioning. There is a problem that the heating function of the device deteriorates and it takes time to reach the target temperature.

It is a well known fact that operating an engine at a temperature as high as possible leads to improvement of fuel efficiency by reducing friction loss of the engine itself, but further in order to accelerate warm-up of the engine at cold start. In addition, generally, control is performed to increase the fuel injection amount during idling until a predetermined temperature (hereinafter, referred to as warm-up control temperature) is reached. Therefore, when the operating oil is heated and heated in a situation where the outside air temperature is low, there is a problem that the rise of the cooling water to the warm-up control temperature is delayed and fuel efficiency is deteriorated.

The present invention has been made by paying attention to such a conventional problem, and in a cooling system for a water-cooled engine equipped with an oil cooler and an air conditioner, when conditions such as an outside air temperature change. Even if there is, it is an object of the present invention to provide a water-cooled engine cooling device capable of improving fuel efficiency without deteriorating the performance of the air conditioner.

[0006]

According to the first aspect of the invention, an oil cooler for circulating cooling water flowing out from a water-cooled engine and adjusting the temperature of the hydraulic fluid of the automatic transmission by exchanging heat with the cooling water is provided. A water cooling type engine cooling device comprising: a water temperature detecting means for detecting the cooling water temperature; and a switching control means for switching the operation of the oil cooler and a switching control means for controlling switching of the switching means. When the detected water temperature is less than a preset temperature set, the switching control means outputs a command to stop the oil cooler to the switching means, and the detected water temperature is set to a preset temperature. In the above case, the means for outputting a command to operate the oil cooler to the switching means is characterized.

According to a second aspect of the present invention, there is provided the water-cooled engine cooling device according to the first aspect, wherein the cooling water is circulated through the tubes and the air in the vehicle interior is targeted by heat exchange with the cooling water. An air conditioning unit that adjusts to the temperature, a circulation unit that variably distributes the flow state of the cooling water in the tube, and the circulation unit to control the flow state of the cooling water in the tube. A control means; and a room temperature detection means for detecting the temperature in the vehicle compartment, wherein the control means, when a value detected by the room temperature detection means is less than the target temperature, a flow state of cooling water in the tube. Is controlled to a range including at least one of the transition region between the laminar flow region and the turbulent flow region and the turbulent flow region adjacent to this transition region.

According to a third aspect of the invention, in the water-cooled engine cooling device according to the first or second aspect, the switching means is a cooling water switching valve for stopping the circulation of the cooling water to the oil cooler. It is characterized by

According to a fourth aspect of the invention, in the water-cooled engine cooling device according to the first or second aspect, the switching means is a hydraulic oil switching valve for stopping the circulation of hydraulic oil to the oil cooler. It is characterized by

According to a fifth aspect of the present invention, in the water-cooled engine cooling device according to the first to fourth aspects, the switching means is a thermostat that automatically switches when a preset temperature is reached. Is characterized by.

According to a sixth aspect of the present invention, in the water-cooled engine cooling device according to the fifth aspect, a hydraulic oil circulation passage for circulating the hydraulic oil to the oil cooler is provided, and the hydraulic fluid circulation passage is provided with the hydraulic oil circulation passage. A hydraulic oil switching valve having a built-in thermostat is provided, and a water temperature supply path for supplying the cooling water temperature to the thermostat built in the hydraulic oil switching valve is provided, and the switching control means is provided with the water temperature of the water temperature supply path. It is characterized in that it is a means for switching the circulation of the hydraulic oil to the oil cooler.

[0012]

The water-cooled engine cooling device according to the present invention is provided with the switching means capable of switching the operation and the stop of the oil cooler. When the detected water temperature is lower than the preset temperature set in the switching control means, a command to stop the oil cooler is output to the switching means, and when the detected water temperature is equal to or higher than the preset temperature set in advance. Is controlled to output a command to operate the oil cooler to the switching means. That is, when the water temperature is lower than the set temperature, the water temperature is raised to the warm-up control temperature quickly, and the engine is operated at a temperature as high as possible to reduce the friction loss of the engine itself and increase the fuel injection amount control time. By shortening the fuel consumption, it is possible to obtain a fuel consumption improvement effect more than the fuel consumption improvement effect due to the rise of the hydraulic oil of the automatic transmission by the oil cooler, and it is possible to improve the fuel consumption particularly at the time of starting the engine.

Further, when the air conditioner is switched on and the room temperature is lower than the target temperature, the circulation of the cooling water to the oil cooler may be stopped. That is, in an environment where the outside air temperature is extremely low, such as in winter, the difference between the outside air temperature and the target temperature in the passenger compartment set by the passenger is large, so that heating of the hydraulic oil and air conditioning are performed. As a result, the energy used for heating the hydraulic oil is large, the heating function of the air conditioner deteriorates, and it takes time to reach the target temperature. However, until the target temperature is reached, when the cooling water temperature is lower than 80 ° C., the operation of the oil cooler is prohibited, thereby achieving stable air conditioning without lowering the heating function of the air conditioner. be able to.

Further, an air conditioner for circulating the cooling water is provided in the tube, and the circulation state of the cooling water in the tube is
The flow means may be controlled in a range including at least one of the transition region between the laminar flow region and the turbulent flow region and the turbulent flow region adjacent to the transition region. That is, the heat exchange efficiency of the air conditioner is improved, and the time for achieving the target temperature can be shortened.

Further, the switching means may be a cooling water switching valve for stopping the circulation of the cooling water to the oil cooler or a hydraulic oil switching valve for stopping the circulation of the hydraulic oil to the oil cooler. More specifically, the switching means may be a thermostat that automatically switches when it reaches a preset temperature.

Further, a hydraulic oil circulation path for circulating hydraulic oil to the oil cooler, a hydraulic oil switching valve having a built-in thermostat, and a water temperature supply for supplying cooling water temperature to the thermostat built in the hydraulic oil switching valve. A passage may be provided, and the switching control means may switch the circulation of the hydraulic oil to the oil cooler according to the water temperature of the water temperature supply passage.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in more detail below.

(Embodiment 1) FIG. 1 is an explanatory view showing a cooling device for a water-cooled engine according to Embodiment 1.
As shown in FIG. 1, the cooling device 1 according to the first embodiment includes a header 4 for cooling water flowing out from a water-cooled engine (hereinafter, simply referred to as an engine) 2 through a cooling water circuit (cooling water distribution pipe) 3. , A radiator 7 as a heat exchanger that cools the cooling water by flowing through a tube 6 arranged between the two.
Is provided.

An electric pump 8 is provided which is driven independently of the engine 2 and circulates cooling water between the engine 2 and the radiator 7. Although only the electric pump 8 is used in the first embodiment, the present invention is not limited to this configuration, and another configuration may be used as long as the circulation amount of the cooling water can be adjusted. For example, by using an electric pump as the main pump, combining a normal water pump driven by the engine as the sub pump, and adjusting the flow rate of the main pump based on the engine speed,
The configuration may be such that the circulation amount of the entire cooling water is adjusted.

Further, a temperature sensor 9 as a temperature detecting means for detecting the temperature of the cooling water in the engine 2 and a room temperature sensor 9a for detecting the room temperature are provided. In addition, a cooling water circuit 10 is provided in the middle of which an electric pump 8 is interposed to allow cooling water to flow from the radiator 7 to the engine 2. In addition, the fan 11 that blows air to the tube 6 of the radiator 7
A rotary drive motor 12 is provided. Also,
An electrically controllable thermostat that diverts the cooling water, which is interposed in the cooling water circuit 3 and is sent from the engine 2 toward the radiator 7, to the suction side of the electric pump 8 via the bypass circuit 13 according to the cooling water temperature. 14 are provided. Further, the control device 1 that controls the drive output of the electric pump 8 and the rotation speed of the rotary drive motor 12 based on the detection values detected by the temperature sensor 9 and the room temperature sensor 9a.
5 are provided.

Further, the cooling water circuit 24 has an air conditioner 25.
Is provided in parallel with the cooling water circuit 24a. The cooling water circuit 24a includes an oil circulation path 28a for circulating oil with the automatic transmission 30, and an oil cooler 28 that exchanges heat with the oil of the automatic transmission 30.
A thermostat 29 is provided for switching the communication of the cooling water circuit 24a to be connectable and disconnectable, and is set to connect the cooling water circuit 24a and the cooling water circuit 24 when the cooling water has a warm-up control temperature (for example, 80 ° C.) or higher. The cooling water circuit 24a is set to be closed at a temperature lower than 80 ° C. Therefore, when the cooling water is below the warm-up control temperature, the automatic transmission oil is not cooled by the oil cooler 28, and when the cooling water is 80 ° C. or higher, the automatic transmission oil is cooled.

A cooling water flow passage 23 is formed in the engine 2 so as to communicate with the cylinder head 21 and the cylinder block 22. The cooling water circuit 10 is connected to the end of the cooling water flow passage 23 on the cylinder head 21 side so as to communicate therewith. On the other hand, at the end of the cooling water flow passage 23 on the cylinder block 22 side, the cooling water circuit 3 described above is provided.
Are connected so that they communicate with each other. That is, the cooling water delivered by the electric pump 8 is set so as to enter from the cylinder head 21 side and be delivered from the cylinder block 22 side.

The radiator 7 is provided with, for example, headers 4 and 5 which are vertically spaced apart from each other, and a large number of tubes 6 which are arranged parallel to each other between the headers 4 and 5, so-called a longitudinal flow. However, a radiator having a so-called transverse flow structure may be used. The tube 6 is appropriately provided with heat exchange plate fins, corrugated fins, and the like.

The cooling water circuit 3 connected to the end of the cooling water flow passage 23 on the cylinder block 22 side is connected to the upper header 4 of the radiator 7. In the middle of the cooling water circuit 3, is electrically controllable thermostat 14 is interposed, the ratio W _R between the flow rate W _B that flows through the flow W _R and the bypass circuit 14 to _flow: the W _B, for example, from 100 ° C. 105 The temperature is set to gradually change from 0: 100 to 100: 0 depending on the temperature of the cooling water.

The thermostat 14 has a lower header 5
And is located in the middle of the cooling water circuit 10 that connects the engine 2, the ratio between the flow rate W _B that flows through the flow W _K and the bypass circuit 13 for circulating the cooling water circuit 10 W _R: to control the W _B You may set it.

Further, a rotary drive motor 12 in which a fan 11 for blowing air is attached to the tube 6 of the radiator 7
Is connected to the control device 15 and is configured to control its rotation speed based on the rotation speed control signal Sr from the control device 15.

The electric pump 8 operates on the basis of the flow velocity control signal Sv from the control device 15 and is configured to change the flow velocity of the cooling water.

The temperature sensor 9 is arranged so as to detect the temperature in the vicinity of the end of the cooling water flow passage 23 of the cylinder block 22. Although the detection end of the temperature sensor 9 is inserted in the cylinder block 22 in the first embodiment, the temperature near the outlet of the cooling water flow passage 23 may be detected.

The controller 15 controls the flow velocity generated by the electric pump 8, in particular, the pipe flow velocity of the radiator 7 and the rotation speed of the rotary drive motor 12 of the fan 11. In particular, by specifying the characteristics of the cooling water flowing through the pipe inside the radiator 7 under high load, power loss is reduced, and it is possible to achieve a significant improvement in fuel consumption.

Before explaining the control and operation of the cooling system 1 for a water-cooled engine according to the first embodiment, the relationship between the water side Reynolds number in the radiator 7, the fan wind speed and the power required for cooling will be described. 4 will be described.

The graph shown in FIG. 4 shows that the core portion (heat dissipation portion) has a lateral dimension of 691.5 mm, a longitudinal dimension of 360 mm, and a depth dimension of 16 mm, when a high load is applied to a general longitudinal flow radiator (cooling water temperature is It is a figure which shows the power required for cooling in the state which reached 105 degreeC and the cooling water is circulating through the radiator 7). In the figure, the horizontal axis represents the water side Reynolds number of the radiator 7 and the fan wind speed (m / sec), and the vertical axis represents the power (W) required for cooling. As shown in FIG.
When the water side Reynolds number of the radiator 7 increases, the power of the electric pump 8 also increases accordingly. Then, when the fan wind speed increases, the fan power, that is, the power of the rotary drive motor 12 increases accordingly.

The sum of the pump power and the fan power, that is, the power required for cooling is low when the water side Reynolds number is 1800 to 6000, as shown in FIG. In the region where the power required for cooling is low, the flow state of the cooling water flowing in the tube 6 of the radiator 7 is a transition region between laminar flow and turbulent flow, and a turbulent flow region near this transition region. It extends to. In such a radiator, when the load is high, the electric pump 8 is controlled so that the Reynolds number is in the 1800 to 6000 region, and the fan 11 is controlled to be in the wind velocity region of 2.8 to 3.3 m / sec, which is necessary for cooling. It is possible to keep the power consumption low, which means that the fuel efficiency is improved at this time.

Incidentally, in the performance of the radiator 7, the performance improvement of the fins formed on the outer side of the tube 6 and the increase of the air volume are the key points of the performance improvement, but the Reynolds number on the water side of the cooling water decreases and turbulent flow occurs. When it disappears, the cooling performance of the cooling water deteriorates extremely, so it is important to use it in turbulent flow as much as possible.

Here, the optimum design for cooling will be described from the viewpoint of energy. In engine cooling with a radiator, we verify whether the balance of cooling water temperature, fan air volume, etc. is most suitable by calculating the energy required for cooling.

(Contribution rate of water amount / air amount of radiator alone) The heat radiation amount of the radiator is obtained by the following formula. (Equation 1) Q = κAΔT However, Q: Radiator heat dissipation (W), κ: Radiator heat transfer rate (W / mm ² K) K value is displayed by using radiator performance as a substitute. It is determined. (Formula 2) 1 / κ = 1 / (αw · Aw / A) + d / (λt · Aw /
A) + 1 / αa · ηa (Equation 3) 1 / κ = 11 (%) + 0.1 (%) + 88.9 (%) As shown in FIG. 5, λt is the tube conductivity (W /
mK), αa is the heat transfer coefficient on the air side (W / m ² K), αw is the heat transfer coefficient on the water side, ηa is the fin integration efficiency (%), Aw is the heat radiation area on the water side (mm ² ), and A is the air side. Heat dissipation area (mm ² ), d
Is the tube plate thickness (mm). Also, Equation 3 is Equation 2
Represents the contribution rate of each term in the calculation, and in the calculation, a longitudinal flow radiator with a core part (heat dissipation part) having a horizontal dimension of 691.5 mm, a vertical dimension of 360 mm, and a depth dimension of 16 mm, with 76 tubes The flow rate was 40 liters / second (Reynolds number 3500) and the wind speed was 3 m / second.

The relationship between the K value and the Reynolds number on the water side is shown in the graph of FIG. FIG. 6 also shows the flow state of the cooling water that changes with the water-side Reynolds number. From FIG. 6, the region where the power required for cooling is low in FIG. 4 described above, that is, the region where the Reynolds number of the cooling water in the tube is 1800 to 6000, is the cooling water flowing in the tube 6 of the radiator 7. It can be seen that the flow state extends over the transition region between laminar flow and turbulent flow and the turbulent flow region near this transition region.

In this state, the contribution rate to the performance on the water and air sides is larger on the air side (88.9%) than on the water side (11%), as in the above mathematical formula 3. Therefore, when the required amount of supplementary heat is increased, it is possible to cool the engine with less power by fixing the amount of water and increasing the air amount of the fan (on the air side). In this way, by determining the Reynolds number of the cooling water in the range in which the power required for cooling is optimized, optimum control is possible in radiators of various forms. The present invention can be applied to a heat exchanger (of a water-cooled engine) including a heater core of any form in which cooling water flows in a pipe.

That is, the Reynolds number Re is Da, the mass velocity of the cooling water is G, the viscosity coefficient is G, and the viscosity coefficient is obtained by multiplying the value obtained by dividing the water passage cross-sectional area by the wet edge length (inner circumference length) by 4. Μ
Then, it is represented by DaG / μ (equivalent diameter × mass velocity / viscosity coefficient), and if this Reynolds number Re is the same,
The flows are mechanically similar and have equal thermal conductivity. Therefore, by controlling the Reynolds number of the cooling water flowing through the various radiators 7 to fall within the range of 1800 to 6000 as described above, the power required for cooling the engine 2 (the sum of the pump power and the fan power). ) Can be the lowest. As a result, the power load can be reduced and the fuel efficiency of the engine can be significantly improved.

(Optimal Air Energy Balance for Cooling Radiator) Next, similar to the radiator 7, the core portion (heat dissipation portion) has a lateral dimension of 691.5 mm, a longitudinal dimension of 360 mm, and a depth dimension of 16 mm. With a vertical flow radiator,
Radiator performance (radiator heat dissipation Q) and air volume (wind speed V)
The relationship between a) and the cooling water flow rate (Gw) is shown in the graph of FIG. The vertical axis represents the radiator heat radiation amount, and the horizontal axis represents the wind speed. In addition, Table 1 below shows the wind speed (V) for obtaining the same performance (radiator heat dissipation) (Q) with the same radiator.
The combination of a) and the cooling water flow rate (Gw) is shown. In this way, the same radiator heat dissipation flow rate of 3.4 × 104W
It is possible to appropriately select the combination of the wind speed and the cooling water flow rate for producing

[0040]

[Table 1] (Amount of Energy Required for Cooling) Next, when the required energies are compared using the theoretical power represented by the following formula 4 on both the air side and the cooling water side, the results shown in the table below are obtained. (Formula 4) P = ρgQH where P: power (W), ρ: fluid density (kg / m ³ ),
g: Gravitational acceleration (m / s ² ), Q: Flow rate (m ³ / s), H: Pressure difference (m)

[Table 2] In Table 2 above, the total required power is the minimum at 280 W, and the Reynolds number at that time is 2600, and the Reynolds number range (1800 to 600) that minimizes the power required for cooling described above.
You can confirm that it is in 0).

By the way, although the air-side contribution to the radiator performance is large, the water-side contribution is small. Therefore, as for the amount of energy, the amount of energy required to cool the engine can be reduced by decreasing the flow rate of the cooling water and increasing the air flow rate. However, if the flow rate of the cooling water decreases to the laminar flow region, the performance on the water side is extremely deteriorated, which is not preferable.

(Control Method of Embodiment 1) The control method and operation of the cooling device 1 for a water-cooled engine will be described with reference to the flowchart shown in FIG. 2 and the diagram showing the relationship between the water temperature and the fan air flow and the water flow shown in FIG. explain. Output data of the electric pump 8 corresponding to the optimum water side Reynolds number shown in FIG. 4 and output data of the rotary drive motor 12 corresponding to the fan wind speed are stored in a memory unit (not shown) provided in the control device 15. Is stored.

In step 101, the electric pump 8 is operated at a flow rate as low as possible (hereinafter referred to as a lower limit flow rate) such that the cooling water in the engine does not locally boil, for example, 10 L / min.

In step 102, the water temperature detected by the temperature sensor 9 is read.

In step 103, it is judged whether or not the air conditioner switch is turned on. When it is turned on, the process proceeds to step 104, and when it is not turned on, the step 1 is performed.
Go to 20.

At step 104, the target temperature for which the detected value detected by the room temperature sensor 9a is set is read and the routine proceeds to step 105.

In step 105, it is determined whether or not the read detection value of the room temperature sensor 9a is higher than the target temperature. If it is higher than the target temperature, the process proceeds to step 120, and if it is lower than the target temperature, the process proceeds to step 106.

In step 106, cooling water is caused to flow through the heater core 26 so that the water side Reynolds number in the tube becomes 2600, and the process proceeds to step 107.

In step 107, it is judged whether the water temperature is higher than 80 ° C., and if it is higher than 80 ° C., step 1
08, the process proceeds to step 109 when the temperature is 80 ° C. or lower.

In step 108, warm water is flown through the oil cooler 28, and the process proceeds to step 112. Oil cooler 28
Also, it is desirable that the Reynolds number on the cooling water side be around 2600.

At step 109, the cooling water is prevented from flowing through the oil cooler 28 and the routine proceeds to step 110.

In step 110, driving of the fan 11 is stopped.

In step 111, the thermostat 14
The cooling water circuit 3 is fully closed, and the bypass circuit 13 is fully opened.

In step 112, it is determined whether or not the water temperature is higher than 105 ° C. If the water temperature is high, the process proceeds to step 113, and if it is low, the process proceeds to step 117.

In step 113, the thermostat 14
The cooling water circuit 3 is fully opened, the bypass circuit 13 is fully closed, and the routine proceeds to step 114.

At step 114, it is judged whether or not the electric pump 8 is driven so that the water side Reynolds number of the radiator 7 becomes 2600, and when it is driving, the routine proceeds to step 115, otherwise to step 116. move on.

At step 115, the drive amount of the fan 11 is increased.

In step 116, the electric pump 8 is driven so that the water side Reynolds number of the radiator 7 becomes 2600.

In step 117, the thermostat 14
Is the flow rate W flowing through the cooling water circuit 3. _RAnd bypass circuit 1
Flow rate of 3_BRatio W with_R: W_BThe cooling water temperature
It gradually changes from 0: 100 to 100: 0 and is distributed.
Let

That is, immediately after the engine is started, the electric pump 8 is driven at a flow rate of 10 L / min (corresponding to FIG. 3). At this time, the circulation of the cooling water to the oil cooler 28 is prohibited. Then, the cooling water flows through the cooling water flow passage 23 of the cylinder head 21 and the cylinder block 22. Along with this, the temperature sensor 9 is connected to the cooling water flow passage 2 of the cylinder block 22.
The temperature detection within 3 is started. In thermostat 14,
Until the temperature of the circulating cooling water reaches 100 ° C, for example,
Cooling water is caused to flow into the bypass circuit 13 and circulate so as to bypass the radiator 7.

Next, it is determined whether the air conditioner is switched on. Here, when the switch is not turned on, the temperature value detected by the temperature sensor 9 is 80
It is determined whether the temperature is higher than ℃. If the cooling water temperature is higher than 80 ° C. in this judgment, warm water is flowed through the oil cooler (corresponding to FIG. 3).

On the other hand, in step 105, it is judged whether or not the vehicle interior temperature is higher than the target temperature of the air conditioner 25. When the vehicle interior temperature is lower than the target temperature, the electric pump 8 is driven so that the Reynolds number of the hot water flowing through the tube of the heater core 26 becomes 2600.

When the temperature of the cooling water coming out of the cylinder block 22 rises to 80 ° C. with the operation of the engine 2, the thermostat 29 opens the cooling water circuit 24a and causes the cooling water to flow to the oil cooler 28 (see FIG. 3). Equivalent to).

Next, in step 112, the flow rate when the cooling water temperature is lower than 105 ° C., the thermostat 14, in response to the coolant temperature, which flows through the flow W _R and a bypass circuit 13 for circulating the cooling water circuit 3 the ratio of W _B be distributed gradually changed.

At this time, if the temperature detected by the temperature sensor 9 has not reached the predetermined target temperature of 105 ° C., the rotary drive motor 12 is not normally driven and the fan 1
No. 1 is not rotating, and the cooling water passing through the tube 6 only exchanges heat with the traveling outside air. In step 118, it is determined whether or not the fan 11 is driven, and when the fan 11 is not driven, the detection of the cooling water temperature is continued. When the fan 11 is driven, the fan 11 is controlled so that the cooling water temperature in the cooling water flow passage 23 of the cylinder block 22 becomes 105 ° C.
Controls the number of revolutions of to be low and continues to detect the cooling water temperature.

The cooling water discharged from the header 5 is supplied to the electric pump 8
And is sent to the cooling water flow passage 23 of the cylinder head 21 via the cooling water circuit 10. When the air conditioner 25 is operating, a fan air volume may be generated according to a request from the air conditioner 25 side.

The temperature of the cooling water, that is, the temperature sensor 9
If the detected temperature of is higher than 105 ℃, thermostat 1
Reference numeral 4 fully closes the bypass circuit 13 and fully closes the cooling water circuit 3 to circulate the cooling water to the radiator 7.

Then, in step 114, it is judged whether the electric pump 8 has the water side Reynolds number of the tube 6 of 2600. When the water side Reynolds number is 2600, the control device 15 outputs the rotation speed control signal Sr to the rotary drive motor 12 so that the cooling water temperature in the cooling water flow passage 23 of the cylinder block 22 becomes 105 ° C. , Fan 1
The rotation of 1 is controlled to increase. On the other hand, when the water-side Reynolds number is not 2600, the drive of the electric pump 8 is controlled so that the water-side Reynolds number is 2600, and the temperature sensor 9 continues to detect the cooling water temperature (corresponding to that in FIG. 3). ).

(Operation and Effect of First Embodiment) In the water-cooled engine cooling device of the first embodiment, the water temperature detected by the temperature sensor 9 is set at a preset temperature (80
When the temperature is lower than 80 ° C, the thermostat 29 stops the circulation of the cooling water to the oil cooler 28, and when the water temperature is equal to or higher than the preset temperature (80 ° C), the thermostat 2
9 controls to circulate the cooling water to the oil cooler 28. That is, when the water temperature is below the set temperature,
By increasing the water temperature quickly to the warm-up control temperature and operating the engine at the highest possible temperature, the friction loss of the engine itself is reduced and the fuel injection amount increase control time is shortened. It is possible to obtain the fuel consumption improvement effect more than the fuel consumption improvement effect due to the increase of the hydraulic oil of the transmission 30, and it is possible to improve the fuel consumption particularly when the engine is started.

When the air conditioner is switched on and the room temperature is lower than the target temperature, the circulation of the cooling water to the oil cooler 28 is stopped. That is, in an environment where the outside air temperature is very low, such as in winter, the difference between the target temperature in the passenger compartment set by the passenger and the outside air temperature is large.
When heating the working oil and air conditioning, the energy used for heating the working oil is large, the heating function of the air conditioner deteriorates, and it takes time to reach the target temperature. However, until the target temperature is reached, when the cooling water temperature is lower than 80 ° C., the operation of the oil cooler is prohibited, so that the heating function of the air conditioner does not deteriorate,
Stable air conditioning can be achieved.

Further, an air conditioner for circulating the cooling water is provided in the tube, and the flow state of the cooling water in the tube is determined by the transition region between the laminar flow region and the turbulent flow region and the turbulent flow region close to the transition region. Alternatively, the electric pump 8 may be controlled in a range including at least one of the regions. That is, the heat exchange efficiency of the air conditioner is improved, and the time for achieving the target temperature can be shortened.

(Second Embodiment) FIG. 8 is an explanatory view showing a cooling device for a water-cooled engine according to a second embodiment.
Since the basic configuration is the same as that of the first embodiment, only different points will be described.

On the oil circulation path 28a for circulating oil between the automatic transmission 30 and the oil cooler 28, a thermostat 28b for switching the circulation state of oil is provided. Further, in the hot water flow passage 24, a thermostat circulation passage 24b through which circulating cooling water circulates is connected to the thermostat 28b.

The thermostat 28b switches the circulation state so as to circulate oil when the temperature of the cooling water in the thermostat circulation path 24b is 80 ° C. or higher. In this way, the operating state of the oil cooler 28 may be switched by switching the circulation of the oil circulating in the oil cooler 28. This makes it possible to obtain the same effects as those of the first embodiment.

(Other Embodiments) As described above, in Embodiments 1 and 2, the flow rate of the cooling water is controlled by using only the electric pump, but only the water pump driven by the engine may be used. However, it goes without saying that the object of the present invention can be achieved even with a configuration including both an electric pump and a water pump.

Further, although the first and second embodiments have been described by taking the example in which the preset temperature is set to 80 ° C., the present invention is not limited to this, and the fuel injection amount at the time of starting is increased. The temperature may be a predetermined temperature (warm-up control temperature) or higher at which the control is performed.

Further, in the first and second embodiments, the thermostat 14 is set so as to gradually change from 0: 100 to 100: 0 depending on the cooling water temperature, for example, between 100 ° C and 105 ° C. However, the present invention is not limited to this, and it goes without saying that the set temperature may be changed depending on the characteristics of the engine, and the set temperature may be variable according to the load state of the engine. good.

[0078]

[Brief description of drawings]

FIG. 1 is a schematic explanatory view showing a water-cooled engine cooling device according to a first embodiment.

FIG. 2 is a flowchart showing the contents of control in the first embodiment.

FIG. 3 is a diagram showing a relationship between an engine water temperature, a fan air volume, and a water flow rate according to the first embodiment.

FIG. 4 is a graph showing the relationship between the power required for cooling, the radiator water side Reynolds number, the fan wind speed, and the relationship between the fan power and the pump power in the first embodiment.

FIG. 5 is an explanatory diagram showing a cooling water flowing in the tube and a heat transfer system.

FIG. 6 is a graph showing a relationship between a K value, a water side Reynolds number, and a fan wind speed.

FIG. 7 is a graph showing the relationship between radiator heat radiation and fan wind speed.

FIG. 8 is a schematic explanatory diagram showing a water-cooled engine cooling device according to a second embodiment.

[Explanation of symbols]

1 Cooling device 2 engine 3 Cooling water circuit 4,5 header 6 tubes 7 radiator 8 electric pumps 9 Temperature sensor 9a Room temperature sensor 10 Cooling water circuit 11 fans 12 rotation drive motor 13 Bypass circuit 14 Thermostat 15 Control device 16 cylinder head 17 cylinder block 23 Cooling water flow passage 24 Hot water flow passage 24a Cooling water circuit 24b thermostat circuit 25 Air conditioner 26 heater core 27 Electromagnetic valve 28 oil cooler 29 Thermostat 30 automatic transmission

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) F16H 57/04 F16H 57/04 G

Claims (6)

[Claims] 1. An oil cooler which circulates cooling water flowing out from a water-cooled engine and adjusts the temperature of hydraulic oil of an automatic transmission by heat exchange with the cooling water, and a water temperature detecting means for detecting the cooling water temperature. In a water-cooled engine cooling device provided with, a switching means capable of switching the operation / stop of the oil cooler and a switching control means for controlling switching of the switching means are provided, and the switching control means controls the detected water temperature. When the temperature is lower than a preset temperature, a command to stop the oil cooler is output to the switching means, and when the detected water temperature is equal to or higher than a preset temperature, a command to operate the oil cooler is issued. A water-cooled engine cooling device characterized in that it is a means for outputting to the switching means. 2. The water-cooled engine cooling device according to claim 1, wherein the cooling water is circulated through a tube to exchange heat with the cooling water to adjust the air in the vehicle interior to a target temperature. A circulation unit that variably distributes the flow state of the cooling water in the tube; a control unit that controls the circulation unit to control the flow state of the cooling water in the tube; Room temperature detecting means for detecting the temperature of, and the control means determines the flow state of the cooling water in the tube when the detected value by the room temperature detecting means is less than the target temperature. A water-cooled engine cooling device, characterized in that the circulation means is controlled in a range including at least one of a transition region between the transition region and the transition region and a turbulent flow region adjacent to the transition region. 3. The water-cooled engine cooling device according to claim 1, wherein the switching means is a cooling water switching valve that stops circulation of cooling water to the oil cooler. Engine cooling system. 4. The water-cooled engine cooling device according to claim 1, wherein the switching means is a hydraulic oil switching valve that stops circulation of hydraulic oil to the oil cooler. Engine cooling system. 5. The water-cooled engine cooling apparatus according to claim 1, wherein the switching means is a thermostat that automatically switches when a preset temperature is reached. Cooling system. 6. The water-cooled engine cooling device according to claim 5, wherein a hydraulic oil circulation path for circulating hydraulic oil to the oil cooler is provided, and the hydraulic oil switching path has the thermostat built in on the hydraulic oil circulation path. A valve is provided, and a water temperature supply path for supplying the temperature of cooling water to the thermostat built in the hydraulic oil switching valve is provided. A water-cooled engine cooling device characterized by being a means for switching circulation.