JP2003049647A - Electric cooling fan device for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electric cooling fan device capable of preventing damage of a duty controller, a harness, or the like when an electric fan controlled by pulse width modulation control is locked, and rapidly cooling a cooling medium after releasing the lock. SOLUTION: When current I of an electric motor is not smaller than a first predetermined current I1 larger than normal current IMa corresponding to the maximum duty ratio DM in control in the normal time, the electric fan is determined to be locked, and the duty ratio is converted to a protective duty ratio DP in which the current I of the electric motor in the lock time of the electric fan is set to be a protective current IP smaller than the first predetermined current I1. When the current I of the electric motor corresponding to the protective duty ratio DP is not larger than a second predetermined current I2 smaller than the protective current IP, the lock of the electric fan is determined to be released and the control is returned to the normal control.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric fan device for cooling a vehicle, and more particularly to an electric fan device for cooling a vehicle that enables control when the electric fan is locked and return control when the electric fan is unlocked.

[0002]

2. Description of the Related Art Conventionally, in a cooling fan device for an automobile,
In an automobile with an air conditioner (AC), the engine cooling water flowing through the radiator is cooled by operating a cooling fan.
The engine cooling water flowing through the radiator and the AC gas flowing through the AC condenser are cooled by a common cooling fan device.

Recently, an electric cooling fan unit using an electric fan as a cooling fan has been widely put into practical use. As this cooling electric fan device, there is conventionally a device that detects the water temperature of engine cooling water and controls to turn ON / OFF the electric fan with a constant water temperature value as a boundary.

However, in such control, when an electric fan having a high rated output is applied, the electric motor is turned off.
When F is switched to ON, a voltage drop occurs, for example, there is a risk of flicker of the headlamp, noise of the electric fan is large when the engine is idle, and ON / OFF switching of the electric fan is frequently performed near the constant water temperature value. There are problems such as what happens, the cooling medium cannot be cooled efficiently, and the power consumption increases.

Therefore, pulse width modulation control (PWM control)
An electric fan device for cooling using is used. In this electric fan device for cooling, the semiconductor switching element is driven to change the duty ratio according to the state of the cooling medium, and the current value of the electric motor, that is, the rotation speed of the electric fan can be arbitrarily adjusted.

[0006] For example, Japanese Patent Publication No. 3102355 also discloses an electric cooling fan device using pulse width modulation control. In this cooling electric fan device, if the electric fan locks for some reason, an abnormal increase in the current value of the electric motor that is in an overload state (overload) is detected and a lock judgment is made to determine the electric current value of the electric motor. A technique is disclosed in which the protection duty ratio is switched so as to lower the voltage.

[0007]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention In an electric fan device that controls to switch ON / OFF of an electric fan with a constant water temperature value of engine cooling water as a boundary, as described above,
Especially when an electric fan with a high rated output is applied, a voltage drop may occur when the electric motor is switched from OFF to ON, for example, the headlamp may flicker, and the noise of the electric fan that is turned ON when the engine is idle is large. ON / O of the electric fan near the constant water temperature value
There are problems such as frequent switching of FFs, inefficient cooling of the cooling medium, and increased power consumption.

Further, in the electric fan device, when the electric fan is locked for some reason (for example, water resistance when traveling on a submerged road, foreign matter getting caught, etc.), the electric motor is overloaded. Overcurrent may flow, causing problems such as disconnection of the harness, blown fuses, and damage to the control unit. Therefore, Patent Publication No. 3
In the cooling electric fan device of Japanese Patent No. 102355, when the electric fan is locked, an abnormal increase in the current value of the electric motor is detected to perform lock determination, and the protection duty ratio is switched to reduce the electric current value of the electric motor. However, it does not describe the control after the electric fan is unlocked.

In other words, if the electric duty of the electric fan is unlocked and the protection duty ratio remains unchanged, the current value of the electric motor in which the overload state has been eliminated decreases and the rotation speed of the electric fan decreases. If the state is left unattended, it is impossible to quickly cool the cooling medium, which is obviously heated up when the electric fan is locked. Eventually, the engine will overheat or the AC efficiency will deteriorate. There is also a fear.

The object of the present invention is to prevent the damage of the duty ratio control device and the like when the electric fan is locked by using the pulse width modulation control and to prevent the cooling medium from being broken when the electric fan is unlocked. An object of the present invention is to provide an electric fan device for cooling a vehicle that can be cooled quickly.

[0011]

According to another aspect of the present invention, there is provided an electric fan device for cooling a vehicle, an electric fan for cooling a cooling medium flowing through a heat exchanger of the vehicle, an electric motor for driving the electric fan, and an electric motor for driving the electric fan. In a cooling electric fan device including a duty ratio control device for driving and controlling an electric motor by pulse width modulation control according to the state of a cooling medium, the duty ratio control device is configured to control the current of the electric motor during normal control. It is determined that the electric fan is locked when the value becomes equal to or larger than the first predetermined current value larger than the current value in the normal state corresponding to the maximum duty ratio, and the electric current value of the electric motor is set to be larger than the first predetermined current value. The protection duty ratio is set to a lower protection current value, and the current value of the electric motor corresponding to this protection duty ratio is less than the second predetermined current value smaller than the protection current value. It is characterized in that it is configured to determine that the electric fan has been unlocked when returning to the lower position, and to return to normal control.

If the electric fan is locked for some reason, an overcurrent will flow to the electric motor that is in an overload state.
At that time, since the current value of the electric motor becomes equal to or higher than the first predetermined current value, at that time, it is determined that the electric fan is locked, and the duty ratio is quickly switched to the protection duty ratio to change the current value of the electric motor. The protection current value can be lower than the first predetermined current value. Therefore, it is possible to reliably prevent the problem that the duty ratio control device or the like is damaged or the harness around the motor is damaged.

Here, when the electric fan is locked,
When the duty ratio less than the maximum duty ratio is set, immediately after the electric fan locks, the current value of the electric motor driven with the duty ratio less than the maximum duty ratio becomes equal to or higher than the first predetermined current value. It may not reach. In this case, since the electric fan is locked,
Since the temperature of the cooling medium rises, the duty ratio also rises, and it is highly possible that the duty ratio eventually becomes the maximum duty ratio. Therefore, the current value of the electric motor becomes equal to or higher than the first predetermined current value while the duty ratio is increasing, and it is determined that the electric fan is locked at that time.

After that, when the electric fan is unlocked, the current value of the electric motor from which the overload condition has been eliminated decreases and becomes less than the second predetermined current value lower than the first predetermined current value. , It is determined that the electric fan has been unlocked, and control returns to normal. Therefore, it is possible to quickly cool the cooling medium whose temperature obviously rises when the electric fan is locked, and it is possible to prevent overheating of the engine and deterioration of the effectiveness of AC as much as possible.

According to a second aspect of the present invention, there is provided an electric fan device for cooling a vehicle according to the first aspect, wherein the first predetermined current value is
It is characterized in that it is set to be equal to or less than the maximum current value of the electric motor when the electric fan is locked, which corresponds to the maximum duty ratio. In other words, if the electric fan locks,
Since the electric current value of the electric motor surely becomes equal to or more than the first predetermined electric current value, it is possible to surely make the determination that the electric fan is locked.

According to a third aspect of the present invention, there is provided an electric fan device for cooling a vehicle according to the first aspect, wherein the second predetermined current value is
It is characterized in that it is set to a value equal to or higher than the minimum current value of the electric motor in a normal state corresponding to a protection duty ratio other than the duty ratio 0. That is, when the electric fan is unlocked, the electric current value of the electric motor is surely equal to or less than the second predetermined current value, and thus the electric fan can be reliably judged to be unlocked.

According to a fourth aspect of the present invention, in the electric fan device for cooling a vehicle according to the first aspect, the duty ratio is set to the maximum duty ratio for a predetermined time immediately after returning to the normal control. It is characterized by that. When the electric fan locks, it is clear that the temperature of the cooling medium rises, and immediately after the control returns to the normal state, the electric fan driven at the maximum duty ratio for a predetermined time immediately removes the increased cooling medium. Can be cooled to.

According to a fifth aspect of the present invention, there is provided an electric fan device for cooling a vehicle according to any one of the first to fourth aspects, wherein a radiator and an air conditioner condenser are provided as the heat exchanger, and the duty ratio control device distributes the radiator. In the case where the air conditioner is not in operation, the first air conditioner is provided with first operation means for calculating the duty ratio according to the water temperature of the cooling water and second operation means for calculating the duty ratio according to the gas pressure in the air conditioner condenser. , The duty ratio calculated by the first calculation means is adopted, and when the air conditioner is operating, the duty ratio calculated by the first calculation means and the second
It is characterized in that the larger duty ratio among the duty ratios calculated by the calculation means is adopted.

If the air conditioner is not operating, the first
When the duty ratio calculated by the calculation means is adopted and the air conditioner is operating, the larger duty of the duty ratio calculated by the first calculation means and the duty ratio calculated by the second calculation means. By adopting the ratio,
An optimum duty ratio (current value of the electric motor) based on the temperature of the cooling water and the gas pressure in the air conditioner condenser can be set to obtain the optimum rotation speed of the electric fan.

[0020]

Embodiments of the present invention will be described below. The present embodiment is an example in which the present invention is applied to a cooling electric fan device equipped with an electric fan, an electric motor, and a motor control device mounted on a vehicle such as an automobile. FIG. 1 shows a configuration diagram of a vehicle cooling electric fan device 1 (hereinafter referred to as an electric fan device 1) of the present invention.
This electric fan device 1 includes two electric fans 2 for cooling a cooling medium flowing through a heat exchanger of a vehicle, two electric motors 3 for driving the two electric fans 2, and two electric motors 3 in parallel. It is composed of a motor control device 4 and the like which are connected and drive-controlled by pulse width modulation control (PWM control) according to the state of the cooling medium. In the following description, "AC" means an air conditioner.

A radiator 5 and an air conditioner condenser 6 (AC condenser 6) are provided as the heat exchanger,
The cooling electric fan device 1 is configured to be able to cool both the engine cooling water flowing through the radiator 5 and the air conditioner refrigerant gas (AC gas) flowing through the AC condenser 6. The radiator 5 and the AC capacitor 6 are arranged side by side in the front-rear direction of the vehicle, and the two electric fans 2 are arranged side by side in the vehicle width direction so as to approach and face the radiator 5.

A battery 7 is connected to the motor control device 4, and the two electric motors 3 are operated by the battery voltage applied via the motor control device 4. Further, the motor control device 4 is connected to an engine control ECU 8 that performs engine control and AC control. This engine control E
In the CU 8, various sensor signals required for engine control are read, and among them, the engine cooling water temperature T, the air conditioner operating state, and the gas pressure P in the AC condenser 6 required for the pulse width modulation control by the motor control device 4 are read. (Predetermined pressure P1
A signal from a gas pressure switch that is turned on when the above is reached, and a signal relating to the battery voltage E and the like are output to the motor control device 4.

The motor control device 4 includes a switching element 10 composed of a MOS-FET and an electric fan control circuit 11.
It has and. The switching element 10 is controlled by PWM control by the electric fan control circuit 11, and when the switching element 10 is turned on, the battery voltage E is applied to each electric motor 3, so that the electric motor 3 is driven.
The electric fan control circuit 11 receives signals from the engine control ECU 8 regarding the water temperature T of the engine cooling water, the operating state of the air conditioner, the gas pressure P of AC gas, the battery voltage E, and the current value I ( Based on the voltage value), ON / OFF switching control of the switching element 10 is performed at every minute time to change the duty ratio D (ratio of ON time of the switching element 10) to change the current value of the electric motor 3 ( An average current value) is arbitrarily adjusted to perform pulse width modulation control. As described above, since the duty ratio is output by the motor control device 4 based on the signal output from the engine control ECU 8, the duty ratio control device according to claim 1 and claim 5 is the engine control EC.
It corresponds to U8 and the motor control device 4.

In this motor control device 4, the radiator 5
The first calculation process of calculating the first duty ratio D1 according to the water temperature T of the engine cooling water flowing through the second duty ratio and the second duty according to the gas pressure P in the AC condenser 6 when the AC is operating. It is configured to perform a second calculation process for calculating the ratio D2.

In the first calculation process, as shown in FIG. 2, the water temperature T of the engine cooling water flowing through the radiator 5 is 98.
The first duty ratio D is less than 98 ° C. and 98 ° C. to 100 ° C. when the temperature rises after less than 98 ° C.
1 is determined to be 0%, and when descending after passing through a temperature of 100 ° C or higher, when the first duty ratio D1 is determined to be 30% when 98 ° C to 100 ° C, and when 100 ° C to 108 ° C. , The first duty ratio D1 is 3 in proportion to the water temperature T.
It is determined to a value within 0 to 90%.

The water temperature T of the engine cooling water is from 108 ° C to 110 ° C.
In case of 110 ° C and 112 ° C when the temperature rises below 110 ° C, the first duty ratio D1 is determined to be 90%. In the case of 110 ° C. to 112 ° C. when descending after passing through, the first duty ratio D1 is determined to be 100%.

In the second arithmetic processing, as shown in FIG.
When the gas pressure P in the C condenser 6 is less than the predetermined pressure P1, the second duty ratio D2 is determined to be 70%,
When the pressure is equal to or higher than the predetermined pressure P1, the second duty ratio D2
Is determined to be 90%. In this motor control device 4, A
When C is not operating, the first duty ratio D1 calculated in the first arithmetic processing is adopted, and when AC is operating, the first duty ratio D1 is calculated in the first arithmetic processing. And the second duty ratio D calculated in the second calculation processing
The larger duty ratio of the two is adopted.

Further, with respect to the adopted duty ratio,
A correction process corresponding to the battery voltage is performed. In this duty ratio correction process, as shown in FIG. 4, a correction coefficient α corresponding to the battery voltage E is obtained (for example, when the normal voltage is 13.5V, the correction coefficient is 1.000, and when the voltage is 12V, the correction coefficient 1.125). Then, the correction coefficient α is multiplied by the adopted duty ratio for correction, and the corrected duty ratio is set as the duty ratio for driving the electric motor 3.

By the way, this motor control device 4 is shown in FIG.
As shown in, the electric current value Ia of the electric motor 3 corresponds to the maximum duty ratio DM (100%), and the electric current value IMa at the normal time is
A first predetermined current value I1 larger than (for example, 31 A)
(Eg 41A) or more, electric fan 2
Is determined to be locked, and the current value I of the electric motor 3 when the electric fan 2 is locked is set to a protection current value IP (for example, 18 A) lower than the first predetermined current value I1. 30%).

Further, the motor control device 4 determines that the electric fan 2 is locked, and then the protection duty ratio DP
The current value I of the electric motor 3 corresponding to (30%) is the second predetermined current value I2 smaller than the protection current value IP (18A).
When it becomes less than (for example, 10 A), it is determined that the electric fan 2 is unlocked, and the control returns to the normal control, and a predetermined time tc immediately after the control returns to the normal control.
The duty ratio D is set to the maximum duty ratio DM (100%).

Regarding the first predetermined current value I1, the maximum current value IMb (for example, 67) of the electric motor 3 corresponding to the maximum duty ratio DM (100%) when the electric fan 2 is locked.
A) and the second predetermined current value I2 (10A), the protection duty ratio DP other than 0 is set.
It is set to the minimum current value Im (for example, 4 A) of the electric motor 3 at the normal time corresponding to (30%).

That is, when the maximum duty ratio DM (100%) is set and the electric fan 2 is not locked, the current value I of the electric motor 3 is IMa (31A).
However, when the electric fan 2 is locked, the electric motor 3 is overloaded (overloaded), and the current value I of the electric motor 3 rises to IMb (67A).
During that time, the electric current value I of the electric motor 3 becomes equal to or higher than the first predetermined electric current value I1 (41A), so that it is determined that the electric fan 2 is locked at this time, and immediately after that, the protection duty ratio DP (30 %) And set. Then, the current value I of the electric motor 3 is changed to the first predetermined current value I1.
Second predetermined current value I2 (10A) smaller than (41A)
The protection current value IP (18A), which is larger than the above, is reduced and maintained.

When the electric fan 2 is unlocked, the overload state of the electric motor 3 is also canceled, so that the current value I of the electric motor 3 driven with the protection duty ratio DP (30%) is Im (4A). ). During that time, the electric current value I of the electric motor 3 becomes equal to or less than the second predetermined electric current value I2 (10 A), so that at this time, it is determined that the electric fan 2 is unlocked, and immediately after that, the maximum duty ratio DM
Set to (100%). Then, the current value I of the electric motor 3 rises to the normal current value IMa (31A) corresponding to the maximum duty ratio DM (100%), and the predetermined time t has elapsed since the maximum duty ratio DM (100%) was set.
The maximum duty ratio DM (100%) is set and maintained until c has elapsed.

If the duty ratio less than the maximum duty ratio DM (100%) is set when the electric fan 2 is locked, the maximum duty ratio DM is set immediately after the electric fan 2 is locked. The current value I of the electric motor 3 driven with a duty ratio of less than (100%) may not reach the first predetermined current value I1 or more. In this case, since the electric fan 2 is locked, the water temperature T of the engine cooling water of the radiator 5 rises and the gas pressure P of the AC gas in the AC condenser 6 rises, so the duty ratio D also rises. Eventually, there is a high possibility that the water temperature T of the engine cooling water will eventually rise to 112 ° C. and the duty ratio D will become the maximum duty ratio DM (100%).

Therefore, while the duty ratio D is increasing, the current value I of the electric motor 3 is changed to the first predetermined current value I1 (4
1A) or more, and at that time, it is determined that the electric fan 2 is locked. Immediately after the electric fan 2 is locked, the current value I of the electric motor 3 is changed to the first predetermined current value I1 (4
1A) or more, the time lag between the actual lock of the electric fan 2 and the lock determination increases, but the current value I is the first predetermined current value I1 from the actual lock of the electric fan 2 to the lock determination. There is no problem because the value does not become higher than (41A).

Next, the calculation setting control of the duty ratio performed by the motor control device 4 will be described with reference to the flowcharts of FIGS. 6 and 7. Note that Si in the flow chart
(I = 1, 2, 3, ...) Shows each step. Also,
The characteristics shown in FIG. 2, FIG. 3, and FIG. 4 are stored in the memory of the motor control device 4 as a map or an arithmetic expression associated with this control.

As shown in FIG. 6, first, engine control E
Various signals related to the engine cooling water temperature T, the operating condition of the air conditioner, the gas pressure P in the AC condenser 6 (a signal from a gas pressure switch that turns on when the pressure exceeds a predetermined pressure P1), the battery voltage E, etc. are read from the CU 8. (S1). Next, the current value I of the electric motor 3 is changed to the first predetermined current value I1 (4
When it is not more than 1A) (S2; No), the first arithmetic processing is executed as described above to determine the first duty ratio D1 (S3). Next, when the AC is operating (S4; Yes), the second arithmetic processing is executed as described above to determine the second duty ratio D2 (S5).

Next, the first duty ratio D1 and the second duty ratio D2 are compared (S6), and when D1> D2 (S6; Yes), the first duty ratio D1 is adopted (S6).
7), when D1> D2 is not satisfied (S6; No), the second duty ratio D2 is adopted (S8). Thus, the first
The larger duty ratio of the duty ratio D1 and the second duty ratio D2 is adopted.

On the other hand, in S3, the first duty ratio D1
If the AC is not operating after the determination of (S4; No
), The first duty ratio D1 calculated in the first calculation process
Is adopted (S7). Then, as described above, the correction process (S9) is executed on the adopted duty ratio according to the battery voltage, the corrected duty ratio is set as the duty ratio of the motor drive (S10), and this duty ratio is set. The achieved control signal is output to the PWM control,
Then return.

When the current value I of the electric motor 3 becomes equal to or larger than the first predetermined current value I1 (S2; Yes), it is determined that the electric fan 2 is locked (S11), as shown in FIG.
The current value I of the electric motor 3 is switched to the protection duty ratio DP (30%) that sets the protection current value IP (18A) (S
12) Then, it is determined whether the current value I of the electric motor 3 is less than or equal to the second predetermined current value I2 (10A) (S13).

When the current value I of the electric motor 3 becomes equal to or less than the second predetermined current value I2 (10A) (S13; Yes), it is determined that the electric fan 2 is unlocked (S14), and the duty ratio is set to the maximum duty ratio DM. Set to (100%) (S
15). Immediately after that, the time is measured and when a predetermined time tc has elapsed (S16; Yes), the process returns.

According to the electric fan device 1 of the present invention, the electric motor 3 is driven and controlled by the pulse width modulation control according to the state of the cooling medium. Therefore, in the normal control, the electric fan 2 having a particularly high rated output is used. When applied, a voltage drop occurs when the electric motor 3 is switched from OFF to ON,
For example, it is possible to solve the problems that the headlamp may flicker, the noise of the electric fan 2 that is turned on when the engine is idle, the cooling medium cannot be efficiently cooled, and the power consumption increases.

In the normal control, the motor control device 4 corresponds to the maximum duty ratio DM (100%) when the current value I of the electric motor 3 is the normal current value IMa (3
1A) and a first predetermined current value I1 (41A) larger than 1A), it is determined that the electric fan 2 is locked, and the electric current value I of the electric motor 3 when the electric fan 2 is locked is set to the first predetermined value. The protection duty ratio DP (30) for setting the protection current value IP (18A) lower than the current value I1 (41A)
%).

That is, when the electric fan 2 is locked for some reason, an overcurrent flows through the electric motor 3 which is in an overload state. At that time, the current value I of the electric motor 3 is the first predetermined current value I1 (41A). ) Is exceeded, at that time, it is determined that the electric fan 2 is locked, the duty ratio D is quickly switched to the protection duty ratio DP (30%), and the current value I of the electric motor 3 is changed to the first predetermined current. Value I1
A protection current value IP (18A) lower than (41A) can be obtained. Therefore, the problem that the motor control device 4 or the like is damaged or the harness around the motor is damaged can be surely prevented.

Further, the motor control device 4 includes the electric fan 2
After locking, the current value I of the electric motor 3 corresponding to the protection duty ratio DP (30%) changes to the protection current value IP (1
8A) and the second predetermined current value I2 (10A) smaller than that, it is determined that the electric fan 2 is unlocked, and control is returned to normal control, and immediately after the control returns to normal control. The duty ratio D is set to the maximum duty ratio DM for a predetermined time tc.

That is, after the electric fan 2 is unlocked, the normal control is promptly returned, and immediately after the return, the electric fan is operated at the maximum duty ratio DM (100%) for the predetermined time tc and the duty ratio D. By rotating 2 at a high speed, the engine cooling water of the radiator 5 and the AC condenser 6 that have risen when the electric fan 2 is in the locked state
By rapidly cooling the cooling medium, it is possible to quickly eliminate the risk of overheating of the engine and difficulty in AC.

Regarding the first predetermined current value I1, the second predetermined current value I2, and the protection current value IP, taking into consideration the output of the electric motor to be applied, the battery voltage of the battery, and the like,
The current value other than the above-mentioned embodiment can be set appropriately.

The maximum duty ratio can be set to a duty ratio other than 100%. For example, when the maximum duty ratio is 90%, when the duty ratio of less than 90% is set, the electric fan is driven at a duty ratio of less than 90% immediately after locking. It is assumed that the electric current value of the electric motor does not reach the first predetermined current value I1 or more.

Here, the first predetermined current value I1 is set to be larger than the normal current value corresponding to the maximum duty ratio of 90% and equal to or less than the electric fan lock current value corresponding to the maximum duty ratio of 90%. Therefore, when the electric fan locks, the rising gas pressure in the AC condenser is P1.
When the above is reached, the duty ratio is switched to 90%, so that the first predetermined current value I1 is reached and the lock determination can be performed.

It should be noted that various modifications can be implemented without departing from the spirit of the present invention.
For example, in the present embodiment, a signal from the engine control ECU 8 is input and the motor control device 4 determines the duty ratio based on this input signal, but the following method may be used. That is, the engine control ECU 8 determines the duty ratio in the same manner as above based on the water temperature T of the engine cooling water, the operating state of the air conditioner, the gas pressure P of the AC condenser 6, and the battery voltage E. However, the duty ratio is, for example, a duty ratio at 0V-5V, and this duty ratio is output to the motor control device 4. The motor control device 4 sets 0V- based on the input duty ratio.
The electric motor 3 is converted to the duty ratio of the battery voltage E.
Drive control. Electric fan 2 by motor controller 4
When it is determined that the motor is locked, the motor control device 4
The lock duty control and the subsequent return control are performed by switching to the protection duty ratio by the engine control ECU 8 during that period.
The duty ratio input to the motor control device 4 from is canceled. Further, it goes without saying that the present invention can be applied to various cooling electric fan devices other than the cooling electric fan device.

[0051]

According to the vehicle cooling electric fan device of the first aspect, when the electric fan is locked for some reason, an overcurrent flows to the electric motor that is in an overload state.
At that time, the electric current value of the electric motor becomes equal to or larger than the first predetermined electric current value which is larger than the electric current value corresponding to the maximum duty ratio. Therefore, at that time, it is determined that the electric fan is locked, and the duty ratio is swiftly protected. By switching to the ratio, the current value of the electric motor can be set to a protection current value lower than the first predetermined current value. Therefore, the problem that the motor control device or the like is damaged or the harness around the motor is damaged can be surely prevented.

When the electric fan is unlocked,
The current value of the electric motor whose overload condition has been eliminated decreases,
Since it becomes the second predetermined current value or less, at that time, it is determined that the electric fan is unlocked, and the control returns to the normal control.
Therefore, it is possible to quickly cool the cooling medium which is apparently raised when the electric fan is locked, and it is possible to prevent the engine from overheating or the effectiveness of AC from being deteriorated.

According to the vehicle cooling electric fan device of the second aspect, the first predetermined current value is set to be equal to or less than the maximum current value of the electric motor when the electric fan is locked, which corresponds to the maximum duty ratio. If the electric fan locks,
Since the electric current value of the electric motor surely becomes equal to or more than the first predetermined electric current value, it is possible to surely make the determination that the electric fan is locked.

According to the vehicle cooling electric fan device of the third aspect, the second predetermined current value is set to be equal to or more than the minimum current value of the electric motor in the normal state corresponding to the protection duty ratio other than the duty ratio 0. Therefore, when the electric fan is unlocked, the electric current value of the electric motor is surely equal to or less than the second predetermined current value, and thus the electric fan can be reliably judged to be unlocked.

According to the electric fan device for cooling a vehicle of the fourth aspect, the duty ratio is set to the maximum duty ratio for a predetermined time immediately after the control returns to the normal state. Therefore, when the electric fan is locked, the cooling medium is cooled. It is clear that the temperature rises, and the raised cooling medium can be quickly cooled by the electric fan driven at the maximum duty ratio for a predetermined time immediately after the control returns to the normal state.

According to the vehicle cooling electric fan device of the fifth aspect, when the air conditioner is not operating, the duty ratio calculated by the first calculating means is adopted, and when the air conditioner is operating. Adopts the larger duty ratio of the duty ratio calculated by the first calculation means and the duty ratio calculated by the second calculation means, and is based on the temperature of the cooling water and the gas pressure in the air conditioner condenser. An optimum duty ratio (current value of the electric motor) can be set to obtain an optimum rotation speed of the electric fan.

[Brief description of drawings]

FIG. 1 is a configuration diagram of an electric cooling fan device according to an embodiment of the present invention.

FIG. 2 is a characteristic diagram showing a relationship between a cooling water temperature and a first duty ratio.

FIG. 3 is a characteristic diagram showing a relationship between a pressure inside a capacitor and a second duty ratio.

FIG. 4 is a characteristic diagram showing a relationship between a battery voltage and a correction coefficient.

FIG. 5 is a diagram showing a current value and a duty ratio in locking and unlocking.

FIG. 6 is a part of a flowchart showing duty ratio calculation setting control.

FIG. 7 is the rest of the flowchart showing the duty ratio calculation setting control.

[Explanation of symbols]

1 Electric fan device for cooling 2 electric fan 3 electric motor 4 Motor control device 5 radiator 6 Air conditioner condenser 8 Engine control ECU

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Kazuya Sugiyama             3-1, Shinchi, Fuchu-cho, Aki-gun, Hiroshima Prefecture Mazda             Within the corporation F-term (reference) 3D038 AA00 AB01 AC14 AC20                 5H570 AA21 BB02 BB09 CC02 DD06                       EE03 FF03 GG04 HA08 HB12                       HB16 JJ18 JJ25 KK05 LL02                       LL20

Claims (5)

[Claims] 1. An electric fan for cooling a cooling medium flowing through a heat exchanger of a vehicle, an electric motor for driving the electric fan, and drive control of the electric motor by pulse width modulation control according to the state of the cooling medium. In the cooling electric fan device including a duty ratio control device for controlling the duty ratio control device, the duty ratio control device is configured such that, in a control at a normal time, a current value of the electric motor is larger than a current value at a normal time corresponding to a maximum duty ratio. It is determined that the electric fan is locked when the current exceeds the first predetermined current value, and the current value of the electric motor is switched to a protection duty ratio that is a protection current value lower than the first predetermined current value. When the electric current value of the electric motor corresponding to is less than or equal to the second predetermined current value smaller than the protection current value, it is determined that the electric fan is unlocked, and the positive value is determined. An electric fan device for cooling a vehicle, which is configured to return to normal control. 2. The vehicle cooling apparatus according to claim 1, wherein the first predetermined current value is set to be equal to or less than the maximum current value of the electric motor when the electric fan is locked, which corresponds to the maximum duty ratio. Electric fan device. 3. The duty ratio of the second predetermined current value is set to 0.
The electric current is set to a value equal to or greater than the minimum current value of the electric motor in a normal state corresponding to a protection duty ratio other than the above.
An electric fan device for cooling a vehicle according to item 1. 4. The electric fan device for cooling a vehicle according to claim 1, wherein the duty ratio is set to the maximum duty ratio for a predetermined time immediately after returning to the normal control. . 5. A radiator and an air conditioner condenser are provided as the heat exchanger, and the duty ratio control device calculates a duty ratio according to a water temperature of cooling water flowing through the radiator, and a duty ratio controller in the air conditioner condenser. A second calculation means for calculating a duty ratio according to the gas pressure is provided, and when the air conditioner is not operating, the duty ratio calculated by the first calculation means is adopted and the air conditioner is operating. In this case, the larger duty ratio of the duty ratio calculated by the first calculation means and the duty ratio calculated by the second calculation means is adopted. An electric fan device for cooling the vehicle described.