JP2003262123A - Device and method for controlling electric fan - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To cool a radiator while maintaining excellent drivability. <P>SOLUTION: An engine ECU 300 controls motors 220, 270 rotating electric fans installed in radiators 200, 250 exchanging the heat of cooling water of an engine 100. The electric power generated by the engine 100 is supplied to motors 220, 270. The engine ECU 300 comprises a temperature sensor 120 detecting the temperature of the cooling water, a linear drive circuit 310 controlling a current flowing in the motor 220 based on the temperature of the cooling water detected by the temperature sensor 120, an on-off driving circuit 330 on-off controlling the motor 270, a CPU 320 stopping the control by the linear driving circuit 310 and starting the control by the on-off driving circuit 330 when the water temperature of the cooling water reaches the predetermined temperature. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for an electric fan provided in a radiator device for heat exchange of cooling water for cooling an engine mounted on a vehicle, and particularly to a drivability good for a vehicle driver. The present invention relates to a control device for an electric fan that provides the electric power.

[0002]

2. Description of the Related Art In an engine mounted on a vehicle such as an automobile, gas is constantly burned in a cylinder, and the temperature of the burned gas reaches 2000.degree. If this is left as it is, the cylinder will be deformed, lubrication will be poor, and the piston will eventually burn into the cylinder. Therefore, it is necessary to cool the engine appropriately.

For this reason, in a normal engine,
A water jacket is provided on the outer circumference of the cylinder and a radiator is provided on the front of the engine, and cooling water is circulated by a water pump to cool the engine.

Japanese Unexamined Patent Publication No. 5-156938 discloses such a radiator cooling device. The cooling device disclosed in this publication is a device for air-cooling two radiators by two fans. The temperature sensor for detecting the temperature of the engine cooling water and the temperature of the engine cooling water are T (1).
When the temperature is T (1) to T (2), only one fan is operated, and when the temperature is T (2) or higher, the operation is stopped. Includes a control circuit for controlling to operate two fans (where T (1) <T (2)).

According to the cooling device disclosed in this publication,
When the temperature of the engine cooling water is lower than T (1), both fans are stopped, and the temperature is T (1) or higher and T
When the temperature is less than (2), only the first fan is operated, and when the temperature is T (2) or more, the two fans are operated together. Therefore, the temperature of the engine cooling water is T
In the low region from (1) to T (2), the amount of heat radiation from the radiator can be reduced, and excessive heat radiation of engine cooling water is eliminated.

[0006]

However, the current flowing through the fan of the cooling device disclosed in this publication is as shown in FIG.
become that way. That is, when the temperature of the cooling water reaches T (2), two fans are operated, so that the current flowing through the motor that rotates the fans suddenly increases. Generally, a motor for rotating a radiator cooling fan mounted on a vehicle is supplied with electric power generated by an alternator connected to a rotating shaft of an engine. In this case, when the temperature of the cooling water reaches T (2), the current value suddenly increases,
A sudden load change occurs in the alternator, and a shock generated based on this load change deteriorates drivability.

Further, there is a method of controlling the current value supplied to the motor for rotating the fan based on the temperature of the cooling water. That is, when the temperature of the cooling water is low, the current value is lowered, the rotation speed of the motor is lowered, and the rotation speed of the fan is lowered. When the temperature of the cooling water is high, the current value is increased, the rotation speed of the motor is increased, and the rotation speed of the fan is increased. When such a current control motor is used and the temperature of the engine cooling water is less than T (1), 2
When both fans are stopped and the temperature is T (1) or more and less than T (2), only the first fan is current-controlled based on the temperature of the cooling water, and the temperature is T (2) or more. In the case of 2, both fans are current-controlled based on the temperature of the cooling water. At this time, the current flowing through the fan of the cooling device is as shown in FIG. That is, even if the current control motor is used, when the temperature of the cooling water reaches T (2), two fans are operated, so that the current flowing through the motor that rotates the fans suddenly increases. Therefore, also in this case, there is a problem in that drivability is deteriorated by a shock generated due to a load change.

The present invention has been made in order to solve the above-mentioned problems, and it is possible to suppress an increase in cost, cool cooling water satisfactorily, and keep the drivability of a vehicle satisfactorily. An object of the present invention is to provide a control device and a control method for an electric fan that cools a fan.

[0009]

A control device according to a first aspect of the present invention controls two or more electric fans installed in a radiator that heat-exchanges a cooling medium of an internal combustion engine. Electric power generated by the internal combustion engine is supplied to the electric fan. This control device changes a current flowing through a first electric fan in the electric fan based on the detection means for detecting the temperature of the cooling medium and the temperature of the cooling medium detected by the detection means. A first control means for controlling the first electric fan, a second control means for controlling a second electric fan in the electric fan, and a detected temperature having a predetermined value. When the condition 1 is satisfied, a switching unit for stopping the control by the first control unit and starting the control by the second control unit is included.

According to the first aspect of the invention, when the temperature of the cooling medium is in a relatively low region, the first electric fan is controlled to cool it. As a result, in a region where the temperature of the cooling medium is relatively low, if the temperature is low in that region,
The first electric fan is rotated at a low rotation speed at a low current value, and when the temperature is high in that region, the first electric fan is rotated at a high rotation speed at a high current value. When the condition that the temperature of the cooling medium exceeds a predetermined temperature is satisfied, the control of the first electric fan is stopped and the operation of the second electric fan is started. At this time, the second electric fan is controlled by the second control means. This allows
In a region where the temperature is relatively low, the first electric fan is controlled based on the detected temperature of the cooling medium, and when the temperature reaches a certain temperature, the first electric fan is stopped and the second electric fan is operated. Therefore, it is possible to prevent a sudden load change. As a result, at least one of the two or more electric fans is current-controlled, and when the temperature reaches a certain temperature, the second electric fan is operated while the current value to the first electric fan is 0. Since it is turned on, there is no abrupt change in the current value, so there is no shock generated due to abrupt load changes in the alternator, and it is possible to provide a controller for an electric fan that cools the radiator and has good drivability. .

In the control device according to the second aspect of the invention, in addition to the structure of the first aspect of the invention, when the switching means satisfies the first condition and the second condition which are predetermined,
It includes means for resuming control by the first control means.

According to the second aspect of the present invention, after the second electric fan is operated in place of the first electric fan, the temperature of the cooling medium further rises and further exceeds a predetermined temperature. When the above condition is satisfied, the first electric fan is operated. At this time, the first electric fan is restarted by using the current value at the time when the first electric fan first started to operate, and the first electric fan is based on the temperature of the cooling medium. Since the current value is determined by the current value, even if the first electric fan restarts while the second electric fan is operating,
There is no sudden change in current value.

In the control device according to the third aspect of the invention, in addition to the configuration of the first or second aspect of the invention, the second control means includes means for controlling on / off of the second electric fan.

According to the third aspect of the present invention, the second electric fan control method does not cause a rapid change in the current value even if the on / off control is inexpensive, so that the cost increase can be suppressed.

In the control device according to the fourth aspect of the invention, in addition to the configuration of the first or second aspect of the invention, the second control means is based on the temperature of the cooling medium detected by the detection means, and is controlled by the second electric motor. Means are included for controlling the second electric fan to vary the current flowing through the fan.

According to the fourth invention, the first electric fan is changed by changing the current flowing through the second electric fan on the basis of the temperature of the cooling medium detected by the detecting means. Of the current value of the second electric fan and the current value of the second electric fan can be suppressed, and the responsiveness of reaching the target value can be improved, and the cooling performance can be improved
The radiator can be cooled well.

A control method according to a fifth aspect of the present invention controls two or more electric fans installed in a radiator that heat-exchanges a cooling medium of an internal combustion engine. Electric power generated by the internal combustion engine is supplied to the electric fan, and the electric fan includes a first electric fan and a second electric fan. This control method is based on a detection step of detecting the temperature of the cooling medium, and a first step based on the temperature of the cooling medium detected in the detection step.
The first control step for controlling the first electric fan, the second control step for controlling the second electric fan, and the detected temperature are predetermined so as to change the current flowing through the electric fan. When the first condition is satisfied, the switching step of stopping the control by the first control step and starting the control by the second control step is included.

According to the fifth aspect of the invention, when the temperature of the cooling medium is in a relatively low region, the first electric fan is controlled to cool it. When the condition that the temperature of the cooling medium exceeds a predetermined temperature is satisfied, the control of the first electric fan is stopped and the second electric fan is operated. At this time, the second electric fan is controlled by the second control means. As a result, in the region where the temperature is relatively low,
The first electric fan is controlled based on the detected temperature of the cooling medium, and when the temperature reaches a certain temperature, the first electric fan can be stopped and the second electric fan can be operated, resulting in a sudden load change. Can be prevented. As a result, current control of at least one of the two or more electric fans,
When the temperature reaches a certain temperature, the operation of the second electric fan is started in a state where the current value to the first electric fan is 0, so that there is no sudden change in the electric current value, so that the alternator makes a sudden change. It is possible to provide a method for controlling an electric fan that cools a radiator without causing shock due to load fluctuation and having good drivability.

In the control method according to the sixth aspect of the invention, in addition to the configuration of the fifth aspect of the invention, in the switching step, when the detected temperature satisfies predetermined first and second conditions, The step of restarting the control by the first control step is included.

According to the sixth aspect of the present invention, after the second electric fan is operated in place of the first electric fan, the temperature of the cooling medium further rises and further exceeds a predetermined temperature. When the above condition is satisfied, the first electric fan is operated. At this time, the first electric fan is restarted by using the current value at the time when the first electric fan first started to operate, and the first electric fan is based on the temperature of the cooling medium. Since the current value is determined by the current value, even if the first electric fan restarts while the second electric fan is operating,
There is no sudden change in current value.

In the control method according to the seventh invention, in addition to the configuration of the fifth or sixth invention, the second control step includes the second control step.
And on / off controlling the electric fan.

According to the seventh aspect of the invention, the second electric fan control method does not cause a rapid change in the current value even with inexpensive on / off control.

In the control method according to the eighth invention, in addition to the configuration of the fifth or sixth invention, the second control step is based on the temperature of the cooling medium detected in the detection step. To change the current flowing through the electric fan, the second
Controlling the electric fan of.

According to the eighth invention, the first electric fan is changed by changing the current flowing through the second electric fan based on the temperature of the cooling medium detected by the detecting means. The radiator can be satisfactorily cooled while suppressing the total value of the current value of 1 and the current value of the second electric fan.

[0025]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. In the following description, the same parts are designated by the same reference numerals. Their names and functions are also the same. Therefore, detailed description thereof will not be repeated.

Referring to FIG. 1, a block diagram of a vehicle engine cooling device including an engine ECU (Electronic Control Unit) according to the present embodiment will be described. Figure 1
As shown in FIG. 3, the engine 100 is provided with a water jacket 110, and a temperature sensor 120 is provided near the outlet (on the radiator side) of the water jacket 110. The temperature sensor 120 is connected to a CPU (Central Processing Unit) 320 of an engine ECU described later. The pipe line connected to the water jacket 110 includes a first radiator 200 and a second radiator 2
Connected to 10. From the outlet of the water jacket 110, the second radiator 2 is driven by the water pump 130.
50, first radiator 200, water jacket 1
Cooling water circulates in the order of 10 inlets.

The first radiator 200 includes a fan 210 for cooling the first radiator 200 and a fan 210.
And a motor 220 for rotating the. Also, the second
The radiator is provided with a fan 260 that cools the second radiator 250 and a motor 270 that rotates the fan 260.

Engine ECU according to the embodiment of the present invention
300 is a fan 2 that cools the first radiator 200.
Linear drive circuit 310 connected to the motor 220 of 10
And an on / off drive circuit 3 connected to a motor 270 that rotates a fan 260 that cools the second radiator 250.
30 and a CPU 320 connected to the linear drive circuit 310 and the on / off drive circuit 330.

The CPU 320 uses the water jacket 11
Based on the water temperature T of the cooling water detected by the temperature sensor 120 provided near the 0 outlet, the linear drive circuit 310
And controlling the on / off drive circuit 330.

Engine ECU 300 according to the present embodiment
The block diagram of the cooling device including may be as shown in FIG. That is, as shown in FIG. 2, the radiator is the first
The radiator 200 and the second radiator 250 may be divided into a single radiator 290. In any case, two or more fans are provided for the radiator. Further, at least one of the two or more fans is connected to the linear drive circuit 3
Controlled by 10.

With reference to FIG. 3, the characteristics of the cooling water temperature and the current value in the linear drive circuit 310 will be described. As shown in FIG. 3, in the linear drive circuit 310, the current value supplied to the motor 220 is controlled to linearly increase as the temperature of the cooling water detected by the temperature sensor 120 increases.

Referring to FIG. 4, on / off drive circuit 330
The characteristics of the cooling water temperature and the current value will be described. As shown in FIG. 4, the on / off drive circuit 330 controls the motor 270 to operate at a certain temperature T (2). The electric power supplied to the motor 220 and the motor 270 is the electric power generated by the alternator connected to the rotating shaft of the engine 100.

Referring to FIG. 5, the program executed by CPU 320 of engine ECU 300 according to the present embodiment has the following control structure.

Step (hereinafter, step is abbreviated as S)
At 100, CPU 320 determines whether or not the sampling time has been reached. This determination is made based on the clock built in the CPU 320. For example,
The sampling time is set to 1 second. When the sampling time comes (YES in S100), the process proceeds to S10.
Moved to 2. If not (N at S100)
O), the process is returned to S100.

In S102, CPU 320 causes temperature sensor 120 to detect the water temperature T of the cooling water. S104
At, CPU 120 determines whether cooling water temperature T is lower than T (1). The temperature T of the cooling water is T
If it is smaller than (1) (YES in S104), the process proceeds to S110. If not (NO in S104), the process proceeds to S106.

At S106, CPU 320 determines whether or not the water temperature T of the cooling water is T (1) ≤T <T (2). When the water temperature T of the cooling water satisfies T (1) ≦ T <T (2) (YES in S106), the process is S10.
Moved to 8. If not (N at S106)
O), the process proceeds to S112.

At S 108, CPU 320 instructs linear drive circuit 310 to operate. As a result, the linear drive circuit 310 operates, the motor 220 starts rotating, and the fan 210 cools the first radiator 200.

In S110, CPU 320 gives a stop instruction to linear drive circuit 310, and ON / OFF drive circuit 3
A stop instruction is given to 30. As a result, the motor 220 and the motor 270 stop, and the fan 210 and the fan 260 stop. Then, the process is returned to S100.

At S112, CPU 320 determines whether or not the water temperature T of the cooling water is T (2) ≤T <T (2) + α. The temperature T of the cooling water is T (2) ≦ T <T (2)
If it is + α (YES in S112), the process is S
It is moved to 114. If not (N in S112,
O), the process proceeds to S116.

At S114, CPU 320 issues a stop instruction to linear drive circuit 310 to turn on / off drive circuit 3
The operation instruction is given to 30. As a result, the linear drive circuit 310 is stopped, the supply of electric power to the motor 220 is stopped, and the fan 210 is stopped. On the other hand, the supply of electric power to the motor 270 is started and the fan 260 rotates.

At S116, CPU 320 determines whether the cooling water temperature T is T (2) + α≤T or not.
When the water temperature T of the cooling water is T (2) + α ≦ T (S11
If YES, the process proceeds to S118. If not (NO in S116), the process returns to S100.

At S118, CPU 320 instructs linear drive circuit 310 to operate and on / off drive circuit 330 to operate. At this time, when the linear drive circuit 310 is instructed to operate, the linear drive circuit 310 causes the S10
8, when receiving an operation instruction from the CPU 320,
The same current value as the current value given to the motor 220 is set to the motor 2
It is controlled so that it is supplied to 20. This current value is called current initial value I (0).

The operation of the cooling device including engine ECU 300 according to the present embodiment will be described based on the structure and flowchart as described above.

When the engine 100 starts to start, the water pump 130 starts to operate, and the cooling water in the water jacket 110 circulates between the radiators 200 and 250.

As the engine 100 continues to rotate,
The temperature of the cooling water in the water jacket 110 rises,
The temperature sensor 120 detects the water temperature T of the raised cooling water.

When the sampling time comes (YES in S100), the temperature T of the cooling water is detected by the temperature sensor 120 (S102). When the water temperature T of the cooling water is smaller than T (1) (YES in S104). ), The linear drive circuit 310 and the on / off drive circuit 330 are instructed to stop. At this time, electric power is not supplied to the motor 220 and the motor 270, and the fan 210 and the fan 260 do not rotate.

In such a state, the water temperature T of the cooling water rises (NO in S104), and the water temperature T of the cooling water becomes T
When (1) ≦ T <T (2) (YE at S106)
S), the CPU 320 instructs the linear drive circuit 310 to operate (S108). At this time, as shown in FIG. 6, when the water temperature T of the cooling water is temperature T (1), a current having an initial current value I (0) is controlled to flow to the motor 220. In this state, the temperature T of the cooling water is T
It continues until (2) is reached.

The temperature T of the cooling water is T (2) ≤T <T
If (2) + α is satisfied (YES in S112), CP
By U320, the linear drive circuit 310 is instructed to stop,
An operation instruction is given to the on / off drive circuit 330 (S1).
14). As a result, the power supply to the motor 220 is stopped and the fan 210 is stopped. On the other hand, the supply of electric power to the motor 270 is started and the fan 260 rotates. At this time, as shown in FIG. 6, a current value I (2) when the motor 270 alone operates.

Further, the water temperature T of the cooling water rises (S112
If the cooling water temperature T satisfies T (2) + α ≦ T (YES in S116), the CPU 320 issues an operation instruction to the linear drive circuit 310 and an operation instruction to the on / off drive circuit. (S118). At this time,
As shown in FIG. 6, when the water temperature T of the cooling water becomes T (2) + α, it is controlled so that a current value I (2) flows through the motor 270 and a current I (0) flows through the motor 220. It As a result, the current value flowing through the motor 220 and the motor 270 becomes I (2) + I (0).

After that, when the temperature T of the cooling water further rises, the linear drive circuit 3 is operated while the motor 270 is operating.
The current value supplied to the motor 220 by 10 increases while maintaining a linear relationship with the increase in temperature. Finally, when the temperature T of the cooling water reaches T (3), the current value I (1) is controlled to flow through the motor 220 and the motor 270.

As described above, in the cooling device including the engine ECU according to the present embodiment, the radiator has at least two electric fans. At least one of the two electric fans is controlled so that the temperature and the current value have a linear relationship. In a region where the temperature of the cooling water is relatively low, only the linear drive controlled electric fan is operated, and when the temperature of the cooling water reaches a predetermined temperature, the linear drive controlled electric fan is stopped. , Starts the operation of the electric fan that is controlled on and off. At this time, since the motor that is linearly controlled is stopped, a sudden load change does not occur and the alternator is not affected. When the temperature further rises, in addition to the operation of the motor that is controlled to be turned on and off, the motor that is stopped by the linear drive control is restarted. At this time, since the current value at the time of restarting is the initial value of the current, the current value does not suddenly change and the alternator does not change suddenly. As a result, it is possible to provide a control device for an electric fan that cools a radiator and that has good drivability.

In the present embodiment, the drive circuit included in the engine ECU has been described as including the linear drive circuit and the on / off drive circuit, but the present invention is not limited to this. A fan for cooling the second radiator may be controlled by a linear drive circuit.
As a result, it is possible to efficiently cool the radiator by the fans that are both linearly controlled.

Furthermore, in the present embodiment, two cooling electric fans are described, but the number of cooling electric fans is not limited to this. The number of electric fans controlled by the engine ECU according to the present embodiment may be two or more, and at least one of the two or more electric fans may be linearly drive-controlled.

Further, the characteristics of the cooling water temperature and the current value in the linear drive circuit 310 are not limited to being linear. Any material may be used as long as the current value increases as the cooling water temperature rises.

The embodiments disclosed this time are to be considered as illustrative in all points and not restrictive. The scope of the present invention is shown not by the above description but by the claims, and is intended to include meanings equivalent to the claims and all modifications within the scope.

[Brief description of drawings]

FIG. 1 is a control block diagram (part 1) including a cooling device according to the present embodiment.

FIG. 2 is a control block diagram (part 2) including the cooling device according to the present embodiment.

FIG. 3 is a diagram showing characteristics of temperature and current value in a linear drive circuit.

FIG. 4 is a diagram showing characteristics of temperature and current value in an on / off drive circuit.

FIG. 5 is a CP that controls the cooling device according to the present embodiment.
7 is a flowchart showing a control structure of a program executed by U.

FIG. 6 is a diagram showing characteristics of temperature and current value in the electric fan of the cooling device according to the present embodiment.

FIG. 7 is a diagram (No. 1) showing characteristics of temperature and current value in the electric fan of the cooling device according to the related art.

FIG. 8 is a diagram (No. 2) showing characteristics of temperature and current value in the electric fan of the cooling device according to the conventional technique.

[Explanation of symbols]

100 engine, 110 water jacket, 12
0 temperature sensor, 130 water pump, 200, 2
50, 290 radiator, 210, 260 fan, 2
20 270 motor, 300 engine ECU, 31
0 linear drive circuit, 320 CPU, 330 on / off drive circuit.

Claims (8)

[Claims] 1. A control device for controlling two or more electric fans installed in a radiator that heat-exchanges a cooling medium of an internal combustion engine, wherein the electric fan receives electric power generated by the internal combustion engine. The control device is supplied, and the control unit flows to a first electric fan in the electric fan based on the detection unit for detecting the temperature of the cooling medium and the temperature of the cooling medium detected by the detection unit. First control means for controlling the first electric fan so as to change an electric current, second control means for controlling a second electric fan in the electric fan, and the detection And a switching unit for stopping the control by the first control unit and starting the control by the second control unit when the predetermined temperature satisfies a predetermined first condition. . 2. The switching means includes means for restarting control by the first control means when the sensed temperature satisfies predetermined first and second conditions. The control device according to claim 1. 3. The second control means includes means for controlling on / off of the second electric fan.
Or the control device described in 2. 4. The second control means changes the current flowing through the second electric fan based on the temperature of the cooling medium detected by the detection means.
A control device according to claim 1 or 2, including means for controlling the electric fan of. 5. A control method for controlling two or more electric fans installed in a radiator that heat-exchanges a cooling medium of an internal combustion engine, wherein the electric fan receives electric power generated by the internal combustion engine. Is supplied, the electric fan is
A first electric fan and a second electric fan are included, and the control method includes a detection step of detecting the temperature of the cooling medium, and the cooling method based on the temperature of the cooling medium detected in the detection step. A first control step for controlling the first electric fan so as to change the current flowing through the first electric fan; a second control step for controlling the second electric fan; and the detected temperature. When the predetermined first condition is satisfied, the control method is stopped, and the control by the first control step is stopped, and the control by the second control step is started. 6. The switching step includes a step of resuming control by the first control step when the detected temperature satisfies a predetermined first condition and a second condition. The control method according to item 5. 7. The control method according to claim 5, wherein the second control step includes a step of performing on / off control of the second electric fan. 8. The second electric fan so as to change the current flowing through the second electric fan based on the temperature of the cooling medium detected in the detecting step in the second control step. The control method according to claim 5 or 6, including the step of controlling.