JP3267820B2 - Electric fan control device - Google Patents

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 for cooling engine cooling water.
The present invention relates to a control device that switches an electric fan on and off in accordance with a cooling water temperature of an engine.

[0002]

2. Description of the Related Art Conventionally, as this kind of technology, for example, a technology disclosed in Japanese Patent Application Laid-Open No. 58-96119 is known. In this technique, an electric fan is provided so as to face a radiator. Then, the coolant temperature of the engine is detected by the coolant temperature sensor, and the electric fan is turned on or off based on the detection result. That is, when the detected water temperature becomes higher than the set temperature for operation, it is determined that the cooling water needs to be cooled, and the microcomputer operates the electric fan. on the other hand,
When the detected water temperature becomes lower than the set temperature for stopping, the microcomputer operates the electric fan assuming that it is not necessary to cool the cooling water. By such control, abnormal rise or fall of the cooling water temperature is suppressed.

In such a cooling system, a thermostat is provided between the engine and the radiator. This thermostat is a type of valve that opens and closes by the temperature of the cooling water. The thermostat blocks the passage between the engine and the radiator when the temperature of the cooling water is lower than a predetermined value, thereby blocking the inflow of the radiator into the water jacket of the engine. On the other hand, when the cooling water temperature is equal to or higher than the predetermined value, the passage between the engine and the radiator is opened, and as a result, the flow from the radiator to the water jacket of the engine is permitted.

[0004]

However, in the above prior art, tolerances, deterioration, etc. of various components including the thermostat have not been considered. For example, it has been empirically found that a thermostat deteriorates with time, and the temperature (predetermined value) at which the thermostat opens and closes with time elapses. Therefore, the timing at which the thermostat opens the passage between the engine and the radiator is delayed, and it has been difficult to effectively lower the cooling water temperature no matter how much the electric fan operates. Therefore, after the electric fan is operated, there is a possibility that the electric fan is not easily stopped and the fan operation rate is increased. As a result, various problems such as an increase in the noise generation time due to the rotation of the fan, a decrease in the durability of the electric fan, an increase in the load on the battery and the alternator, and a deterioration in the fuel consumption may occur.

[0005] Further, the above-mentioned problem may occur not only due to deterioration of the thermostat, but also due to its tolerance or tolerance or deterioration of other components such as a water temperature sensor.
The present invention has been made in view of the above circumstances,
An object of the present invention is to provide an electric fan control device capable of suppressing occurrence of a malfunction due to an increase in a fan operation rate.

[0006]

According to the first aspect of the present invention, there is provided an engine M including at least a radiator M1 as shown in FIG.
An electric fan M3 which is provided opposite to the radiator M1 to cool the cooling water in the cooling water passage 2 and is operated / stopped, and a water temperature detecting means M4 for detecting the temperature of the cooling water; When the water temperature detected by the water temperature detecting means M4 becomes higher than the first set temperature and the cooling water needs to be cooled, the electric fan M3 is operated and the water temperature detected by the water temperature detecting means M4 is detected. A control unit M5 for stopping the electric fan M3 when the coolant temperature becomes lower than the second set temperature and there is no need to cool the cooling water. Malfunction determining means M6 for determining whether or not the electric fan M3 malfunctions outside the set temperature ranges due to tolerances and deterioration of components related to the fan control device; When the malfunction judging means M6 judges that the electric fan M3 malfunctions, the gist is that a correcting means M7 for correcting at least one of the first set temperature and the second set temperature is provided. .

Further, in the invention according to claim 2,
The malfunction determining means M6 according to the first aspect of the invention detects the water temperature change rate detecting means M61 for detecting a change rate of the water temperature when the electric fan M3 is stopped, and the water temperature change rate detecting means M61. The change rate comparing means M62 for determining whether the actual rate of change is lower than a predetermined reference change rate, and the change rate comparing means M62,
When it is determined that the actual rate of change is lower than the reference rate of change, the electric fan M3 includes first certifying means M63 that certifies that the electric fan M3 malfunctions outside the range of the set temperatures. It is a gist.

Further, according to the third aspect of the present invention, the malfunction determining means M6 according to the first aspect of the present invention.
Are operating time detecting means M64 for detecting the time during which the electric fan M3 is operating, and operating time detecting means M
The operation time comparison means M65 which determines whether the actual operation time detected by the operation 64 is longer than a predetermined reference time, and the operation time comparison means M65 determines that the actual operation time is longer than the reference time. Is also long,
The gist is that the electric fan M3 includes second certifying means M66 for certifying that the electric fan M3 malfunctions outside the set temperature ranges. Further, in the invention according to claim 4, an electric fan which is provided opposite to the radiator to cool the cooling water in the cooling water passage of the engine including at least the radiator, and which is switched between operation and stop, Water temperature detecting means for detecting the temperature of the cooling water, and when the water temperature detected by the water temperature detecting means becomes higher than a first set temperature and the cooling water needs to be cooled, the electric fan And a control means for stopping the electric fan when the water temperature detected by the water temperature detection means becomes lower than a second set temperature and there is no need to cool the cooling water. A fan control device, comprising: a water temperature change rate detection means for detecting a change rate of water temperature when the electric fan is stopped; and a water temperature change rate detection means. The change rate comparing unit that determines whether the actual change rate is lower than a predetermined reference change rate, and the change rate comparing unit determines that the actual change rate is lower than the reference change rate. The gist of the invention is a control device for an electric fan including a correction unit that corrects at least one of the first set temperature and the second set temperature to a higher temperature. Further, in the invention according to claim 5, an electric fan which is provided opposite to the radiator to cool the cooling water in the cooling water passage of the engine including at least the radiator, and which is switched between operation and stop, Water temperature detecting means for detecting the temperature of the cooling water, and when the water temperature detected by the water temperature detecting means becomes higher than a first set temperature and the cooling water needs to be cooled, the electric fan And a control means for stopping the electric fan when the water temperature detected by the water temperature detection means becomes lower than a second set temperature and there is no need to cool the cooling water. A fan control device for detecting a time during which the electric fan is operated.
Operating time detecting means and the operating time detecting means.
Actual operating time is longer than the predetermined reference time.
Operating time comparing means for determining whether the operation time is long or not;
The actual operation time is longer than the reference time
When it is determined that the long, the control apparatus for an electric fan and a correcting means for correcting at least one of the first set temperature and a second set temperature to a higher temperature is set to its gist.

[0009]

According to the above arrangement, as shown in FIG. 1, the temperature of the cooling water is detected by the water temperature detecting means M4. When the water temperature becomes higher than the first set temperature and it becomes necessary to cool the cooling water, the electric fan M
3 operates. On the other hand, when the detected water temperature becomes lower than the second set temperature and the cooling water does not need to be cooled, the electric fan M3 is stopped by the control means M5. By operating the electric fan M3, the cooling water in the cooling water passage of the engine M2 including at least the radiator M1 can be cooled.

According to the present invention, the malfunction judging means M6 determines whether or not the electric fan M3 malfunctions outside the set temperatures due to tolerances and deterioration of components related to the electric fan control device. It is determined whether or not. When the malfunction judging means M6 judges that the electric fan M3 malfunctions, at least one of the first set temperature and the second set temperature is corrected by the correcting means M7. For this reason, even if the electric fan M3 becomes in a state where it can malfunction out of the range of each set temperature due to tolerances and deterioration of related parts, the set temperature is corrected, and the actual water temperature is considerably lowered. By not doing so, abnormally prolonged operation of the electric fan M3 is suppressed.

According to the second aspect of the present invention, in the operation of the first aspect, the malfunction determining means M
6, the water temperature change rate detecting means M61 detects the change rate of the water temperature when the electric fan M3 is stopped, and determines whether the detected actual change rate is lower than a predetermined reference change rate. The determination is made by the change rate comparing means M62. Further, when the change rate comparing means M62 determines that the actual change rate is lower than the reference change rate, the first qualifying means M63 causes the electric fan M3 to malfunction out of the range of each set temperature. Be certified. Therefore, the malfunction can be reliably and easily determined.

Further, according to the third aspect of the present invention,
In the operation of the first aspect of the present invention, the operating time detecting means M64 of the malfunction determining means M6 detects the time during which the electric fan M3 is operated, and the detected actual operating time is determined in advance. The operation time comparison means M65 determines whether or not the time is longer than the predetermined reference time.
When the actual operation time is determined to be longer than the reference time by the operation time comparison means M65, the second qualification means M66 certifies that the electric fan M3 malfunctions outside the range of each set temperature. Is done. Therefore, claim 2
As in the operation of the invention described in (1), the determination of the malfunction can be made reliably and easily.

[0013]

【Example】

(First Embodiment) Hereinafter, a first embodiment of a control device for an electric fan according to the present invention will be described in detail with reference to FIGS.

FIG. 2 schematically shows a V-type engine (hereinafter simply referred to as an engine) 1 having a plurality of cylinders. These cylinders are divided into two banks, and each bank is arranged in a V-shape around a crankshaft (not shown). The engine 1 burns a mixture of fuel and air to obtain thermal energy, and converts the thermal energy into power. Some of the heat energy that is not converted to power is lost together with the exhaust gas or as friction loss, and the rest is absorbed by various parts of the engine 1. In order to prevent the engine 1 from being overheated by the absorbed heat, a water-cooled cooling device described below is provided.

In the cylinder block 2 of the engine 1,
A water jacket 3, which is a passage for cooling water, is provided. A water jacket 5 is provided in each cylinder head 4 so as to communicate with the jacket 3. The downstream ends of the two water jackets 5 merge into one.

A radiator 9 including an upper tank 6, a core 7, and a lower tank 8 is disposed in front of the engine 1 (left side in FIG. 2). The core 7 includes a number of tubes 7a connecting the upper tank 6 and the lower tank 8, and cooling fins 7b provided around the tubes 7a.
And The cooling water that has passed through the water jackets 3, 5 flows in the order of the upper tank 6, the core 7, and the lower tank 8.

The water jacket 5 in the cylinder head 4 is connected to the upper tank 6 by a first passage 11. Further, the water jacket 3 in the cylinder block 2 is connected to the lower tank 8 by the second passage 12. These water jackets 3, 5 and the first passage 1
1, a radiator 9, a second passage 12, and a bypass passage 15 described later form a cooling water passage 13.

In the cylinder block 2, the second passage 1
A water pump 14 composed of a centrifugal pump is attached to a connection portion between the water jacket 2 and the water jacket 3. The water pump 14 is connected to a crankshaft by a pulley, a belt, or the like, and is operated by rotation of the crankshaft accompanying operation of the engine 1. The water pump 14 suctions the cooling water in the second passage 12 and discharges the cooling water to the water jacket 3. By the suction and the discharge, the cooling water circulates in the cooling water passage 13 starting from the water pump 14. During this circulation, the cooling water absorbs heat of the engine 1 and rises in temperature while passing through the water jackets 3 and 5. The heated cooling water basically radiates heat from the cooling fins 7 b when passing through the core 7 of the radiator 9.

The first passage 11 and the second passage 12 are communicated by a bypass passage 15, and the cooling water in the first passage 11 can bypass the radiator 9 and flow to the second passage 12 via the bypass passage 15. It has become.

The bypass passage 1 for the second passage 12
A thermostat 16 is provided at the junction 15a of the fifth thermometer. The thermostat 16 is a temperature-sensitive valve that operates in accordance with the temperature of the cooling water. In the present embodiment, a so-called wax-type one that opens and closes a passage with a valve body using expansion and contraction due to heat of wax is used. ing. It should be noted that a bellows type thermostat may be used instead of the wax type.

When the temperature of the cooling water (cooling water temperature) THW is equal to or lower than a predetermined value, the thermostat 16 closes the second passage 12 to cut off the flow of the cooling water from the radiator 9 to the water jacket 3. Then, the bypass passage 15 is opened to allow the flow of the cooling water from the passage 15 to the second passage 12. When the temperature of the cooling water is higher than the predetermined value, the thermostat 16 opens the second passage 12 to allow the cooling water to flow from the radiator 9 to the water jacket 3 and closes the bypass passage 15, The flow of the cooling water from the passage 15 to the second passage 12 is blocked. Further, in the present embodiment, although not shown, the downstream portions of the first passage 11 and the second passage 12 below the thermostat 16 are communicated with each other by an auxiliary passage having a smaller passage area than the circulation passage 13, and in the middle thereof. Is provided with a reservoir tank. The reservoir tank is for absorbing a change in the volume of cooling water caused by a change in temperature. The air chamber for absorbing the change in the volume of the cooling water may be provided in the upper tank 6 of the radiator 9.

In this embodiment, an electric fan 17 is provided so as to face the radiator 9. The electric fan 17 is driven by the radiator 9
And a motor 19 for rotating the impeller 18.

A water temperature sensor 20 for detecting the temperature of cooling water (cooling water temperature THW) is provided in the first passage 11 of the engine 1 (may be inside the water jacket 3). Further, the engine 1 and the like are provided with the following other various sensors. That is, a throttle position sensor for detecting a throttle opening is provided in the vicinity of the throttle valve, and a distributor is provided with a rotation speed sensor for detecting the engine rotation speed from the rotation of the rotor. Further, an air flow meter for detecting an intake air amount is provided downstream of the air cleaner.

Further, the accelerator pedal, which is depressed by the driver and adjusts the engine speed, is provided with an accelerator operation amount sensor for outputting a voltage signal corresponding to the operation amount (accelerator opening). In addition, sensors for detecting various operating states, such as an intake air temperature sensor, a vehicle speed sensor, and a neutral switch, are provided.

Various sensors including the water temperature sensor 20 include an electronic control unit (hereinafter referred to as “ECU”) 31.
Is electrically connected to the input side. A drive circuit 21 for rotating the motor 19 by switching the energization or non-energization of the motor 19 is electrically connected to the output side of the ECU 31.

In the present embodiment, the ECU 31 includes a control unit, a malfunction determination unit, a correction unit, a water temperature change rate detection unit,
It constitutes the change rate comparing means and the first qualifying means. The ECU 31 also includes a central processing unit (CPU), a read-only memory (ROM), a random access memory (RAM), a backup RAM, an input port,
Output ports, which are connected to each other by a bus 38. The CPU executes various arithmetic processing according to a preset control program, and the ROM previously stores a control program and initial data necessary for executing the arithmetic processing by the CPU. Further, the RAM temporarily stores the calculation result of the CPU.

Detection signals from various sensors such as the water temperature sensor 20 are input to various input ports. The CPU performs various conversions and calculations based on these signals, and finally outputs a drive signal for driving the motor 19 to the drive circuit 21 via the output port.

Next, the operation and effect of the embodiment constructed as described above will be described. The flowchart shown in FIG. 3 is an “electric fan control routine” performed as an operation for controlling the motor 15 to operate and stop the electric fan 17 among the processes executed by the ECU 31. Executed by a periodic interrupt.

When the processing shifts to this routine, the ECU
First, at step 101, the water temperature sensor 20
Based on the detection results of various sensors and the like, signals indicating various operating states such as the cooling water temperature THW are read.

Next, at step 102, it is determined whether or not the current cooling water temperature THW is higher than the fan operation reference temperature TFON. Then, if the cooling water temperature THW is higher than the fan operation reference temperature TFON, step 1
At 03, a predetermined signal is output to the drive circuit 21 to operate (turn on) the electric fan 17, and the motor 19 is driven. Then, the subsequent processing ends once.

If the cooling water temperature THW is not higher than the fan operation reference temperature TFON, the routine proceeds to step 104. In step 104, it is determined whether the electric fan 17 is currently operating. If the electric fan 17 is not operating, the subsequent processing is temporarily terminated.

On the other hand, if the electric fan 17 is operating, it is determined in step 105 whether the current cooling water temperature THW is lower than the fan stop reference temperature TFOFF. In this embodiment, the fan stop reference temperature TFOFF is set to a value lower than the fan operation reference temperature TFON. That is, the fan stop reference temperature TF
Hysteresis is provided between OFF and the fan operation reference temperature TFON. If the cooling water temperature THW is not lower than the fan stop reference temperature TFOFF, it is determined that the cooling water temperature THW exists during the hysteresis and the electric fan 17 does not need to be stopped yet.
Thereafter, the processing is temporarily terminated.

On the other hand, if the cooling water temperature THW is lower than the fan stop reference temperature TFOFF, it is determined that the cooling water has been sufficiently cooled, and in step 106, the electric fan 17 is driven to stop (turn off). A predetermined signal is output to the circuit 21 to stop the motor 19.

Subsequently, in step 107, based on the various signals read this time, the current operation state is recognized, and it is determined whether a predetermined learning condition is satisfied. The learning conditions here include, for example, that the vehicle is idling, that the air conditioner is not operating, that the vehicle speed is “0”, that the intake air temperature is within a predetermined range, and the like. When the learning condition is not satisfied, the subsequent processing is temporarily terminated.

When the learning condition is satisfied,
In step 108, it is determined whether or not the temperature change rate ΔT immediately before the stop of the electric fan 17 is lower than a predetermined reference change rate α. As shown in FIGS. 4 and 5, the temperature change rate ΔT is determined by comparing the cooling water temperature THW when the electric fan 17 is stopped by a predetermined time A and the cooling water temperature THW when the electric fan 17 is stopped. Is divided by a predetermined time A (ΔT = B / A). Here, when the thermostat 16 deteriorates with time, the temperature at which the thermostat 16 opens and closes (predetermined value) tends to increase. in this case,
As shown in FIG. 4, even when the electric fan 17 is operated, the cooling water temperature THW is hard to decrease, and it takes time until the electric fan 17 actually stops.
The temperature change rate ΔT tends to decrease. For this reason, when the temperature change rate ΔT becomes lower than the reference change rate α,
Deterioration of the thermostat 16 occurs, and the electric fan 17
Is found to be malfunctioning outside the range of the original reference temperatures. If the temperature change rate ΔT is lower than the predetermined reference change rate α in step 108, each reference temperature is corrected and the electric fan 1
It is determined that it is necessary to avoid prolonging the operation time of step 7, and the process proceeds to step 109.

That is, in step 109, a value obtained by adding the predetermined value β to the previous fan operation reference temperature TFON is set as a new fan operation reference temperature TFON, and the previous fan stop reference temperature TFOF is set.
A value obtained by adding a predetermined value γ to F is set as a new fan stop reference temperature TFOFF. And ECU3
1 temporarily ends the subsequent processing. Step 1
In 08, when the temperature change rate ΔT is not lower than the reference change rate α, it is determined that there is no need to correct each reference temperature, and the subsequent processing is temporarily terminated.

As described above, in this embodiment,
When the thermostat 16 is functioning normally,
As shown by the solid line in FIG. 4, when the cooling water temperature THW reaches the initial fan operation reference temperature TFON, the electric fan 17
Is turned on (timing t1). As a result, the cooling water is cooled, and thereafter, the cooling water temperature THW decreases.
The cooling water temperature THW is equal to the initial fan stop reference temperature T.
When FOFF is reached, the electric fan 17 is turned off (timing t2).

On the other hand, when the thermostat 16 or the like deteriorates, its own opening / closing temperature tends to increase. For this reason, even if the electric fan 17 operates (timing t1), the cooling water from the radiator 9 is not guided toward the water jackets 3, 5, and the cooling water is not easily cooled. Therefore, in the related art, as shown by a broken line in FIG. 4, a phenomenon that the cooling water temperature THW does not readily decrease may occur. As a result, the cooling water temperature T
It takes a long time for the HW to reach the initial fan stop reference temperature TFOFF (timing t2a), and the electric fan 1
7 caused an increase in the operating rate.

In this embodiment, when a predetermined learning condition is satisfied, a temperature change rate ΔT for a predetermined time A before the electric fan 17 is stopped is detected, and the temperature change rate ΔT is determined. When the rate of change becomes lower than the reference change rate α, the thermostat 16 is degraded, and the electric fan 17 is recognized to be erroneously operated outside the range of each of the initial reference temperatures. In such a case, a value obtained by adding a predetermined value β to the previous fan operation reference temperature TFON is set as a new fan operation reference temperature TFON, and
A value obtained by adding a predetermined value γ to the previous fan stop reference temperature TFOFF is set as a new fan stop reference temperature TFOFF. For this reason, as indicated by the dashed line in FIG. 4, the electric fan 17 is turned on at a higher fan operation reference temperature TFON (timing t1b), and is turned off at a higher fan stop reference temperature TFOFF. (Timing t2b).

For this reason, even if the electric fan 17 can malfunction out of the initial reference temperature range due to tolerances and deterioration of related components such as the thermostat 16 and the water temperature sensor 20, the set temperature can be maintained. Is appropriately corrected. Then, it is possible to suppress the operation of the electric fan 17 from being abnormally prolonged due to the fact that the actual cooling water temperature does not easily decrease. As a result, the electric fan 1
7, it is possible to suppress an increase in noise generation time associated with an increase in the operation rate. Further, the durability of the electric fan 17 is improved,
Life can be extended. Further, the load on the battery and the alternator can be reduced, adverse effects on these can be prevented, and deterioration of fuel efficiency can be suppressed.

In the present embodiment, when the temperature change rate ΔT becomes lower than the reference change rate α, it is determined that the electric fan 17 malfunctions. Therefore, it is possible to reliably and easily determine the malfunction.

Second Embodiment Next, a second embodiment of the present invention will be described with reference to FIGS. However, since the configuration and the like of this embodiment are the same as those of the above-described first embodiment, the same members and the like are denoted by the same reference numerals and description thereof will be omitted. The following description focuses on the differences from the first embodiment.

In this embodiment, there is a great difference from the first embodiment in the method of judging malfunction of the electric fan 17. The ECU 31 constitutes control means, malfunction determination means, correction means, operation time detection means, operation time comparison means, and second qualification means.

Next, the operation and effect of the embodiment constructed as described above will be described. The flowchart shown in FIG. 6 is an “electric fan control routine” that is executed as an operation for controlling the motor 15 to operate and stop the electric fan 17 among the processes executed by the ECU 31. Executed by a periodic interrupt.

When the processing shifts to this routine, the ECU
First, at step 201, the water temperature sensor 20
Based on the detection results of various sensors and the like, signals indicating various operating states such as the cooling water temperature THW are read.

Next, at step 202, it is determined whether or not the current cooling water temperature THW is higher than the fan operation reference temperature TFON. If the cooling water temperature THW is not higher than the fan operation reference temperature TFON, it is determined in step 203 whether the electric fan 17 is operating (ON). If the electric fan 17 is not operating, the subsequent processing is temporarily terminated. If the electric fan 17 is operating, it is determined in step 204 whether the current cooling water temperature THW is lower than the fan stop reference temperature TFOFF. When the cooling water temperature THW is not lower than the fan stop reference temperature TFOFF, it is determined that the cooling water temperature THW exists during the hysteresis already described, and it is not necessary to stop the electric fan 17 yet, and the subsequent processing is temporarily performed. finish.

If the cooling water temperature THW is lower than the fan stop reference temperature TFOFF, a predetermined signal is output to the drive circuit 21 to stop (turn off) the electric fan 17 in step 205, and the motor 19 is turned off. Stop. Then, in step 206, the count value C of the counter is cleared to "0", and the subsequent processing is temporarily terminated.

On the other hand, if the cooling water temperature THW is higher than the fan operation reference temperature TFON in step 202, the process proceeds to step 207. In step 207, in order to operate (turn on) the electric fan 17,
A predetermined signal is output to the drive circuit 21 to operate the motor 19.

Next, in step 208, based on the various signals read this time, the current operation state is recognized and predetermined learning conditions (substantially the same as in the first embodiment).
It is determined whether or not is established. If the learning condition is not satisfied, the process jumps to step 206, where the count value C of the counter is cleared to "0", and the subsequent processing is temporarily terminated.

When the learning condition is satisfied,
In step 209, the count value C of the counter is incremented by "1" to measure the operation time.
Next, in step 210, it is determined whether or not the count value C is greater than a predetermined reference value T0, that is, whether or not the operation time of the electric fan 17 is longer than a predetermined reference time. to decide. Here, when the thermostat 16 deteriorates with time, the temperature at which the thermostat 16 opens and closes (predetermined value) tends to increase. In this case, as shown in FIG. 7, even if the electric fan 17 is operated, the cooling water temperature THW does not easily decrease, and it takes time until the electric fan 17 actually stops. That is, the operation time tends to be long. For this reason, if the operation time is longer than the reference time, the thermostat 16 is deteriorated and the like, and the electric fan 17 is recognized as being erroneously operable outside the range of the respective reference temperatures. Then, the above step 21
At 0, if the count value C is larger than the reference value T0, it is determined that it is necessary to correct each reference temperature to avoid prolonging the operation time of the electric fan 17, and the process proceeds to step 211.

That is, in step 211, a value obtained by adding a predetermined value β to the previous fan operation reference temperature TFON is set as a new fan operation reference temperature TFON, and the previous fan stop reference temperature TFOF is set.
A value obtained by adding a predetermined value γ to F is set as a new fan stop reference temperature TFOFF. And ECU3
1 temporarily ends the subsequent processing. Step 2
In 09, when the count value C is not larger than the reference value T0, that is, when the operation time of the electric fan 17 is shorter than the reference time, the count is continued when predetermined conditions are satisfied in the next routine. In order to achieve this, the subsequent processing ends once.

As described above, in the present embodiment, although there is a difference in a method of judging a malfunction of the electric fan 17, basically the same operation and effect as in the above-described first embodiment are exerted. . That is, when the predetermined learning condition is satisfied and the operation time of the electric fan 17 is longer than the reference time, the thermostat 16
Is degraded, and it is determined that the electric fan 17 can malfunction out of the range of each of the initial reference temperatures. In such a case, the fan operating reference temperature TFON
Is a value obtained by adding a predetermined value β to a new fan operating reference temperature T.
A value obtained by adding a predetermined value γ to the previous fan stop reference temperature TFOFF is set as a new fan stop reference temperature TFOFF. For this reason, as shown by the dashed line in FIG.
It is turned on at a higher fan operation reference temperature TFON than before (timing t1b), and is turned off at a higher fan stop reference temperature TFOFF (timing t2).
b).

Therefore, even if the electric fan 17 can malfunction out of the range of the initial reference temperature, the operation of the electric fan 17 can be suppressed from being abnormally prolonged. As a result, an effect similar to that of the first embodiment is obtained.

The present invention is not limited to the above embodiments,
For example, the configuration may be as follows. (1) In the above embodiment, when the fan operation reference temperature TFON and the fan stop reference temperature TFOFF are corrected, it is determined whether or not the learning condition is satisfied.
This may be embodied when the judgment of the learning condition is not performed.

(2) In the above embodiment, the predetermined value β is added to the fan operation reference temperature TFON and the predetermined value γ is added to the fan stop reference temperature TFOFF for correction. May be the same value. Further, it may be a value that varies according to various conditions.

(3) In the above embodiment, the present invention is embodied in the case of the cooling system of a V-type engine, but may be embodied in the case of another in-line engine. (4) In the above embodiment, the thermostat 16 is provided at the junction 15a of the bypass passage 15 with the second passage 12, but may be provided at the junction of the first passage 11 and the bypass passage 15.

The technical ideas that are not described in each claim of the claims but can be grasped from each of the above embodiments are described below together with their effects. (A) The electric fan control device according to any one of claims 1, 2 and 3, wherein a thermostat is included as one of the components related to the electric fan control device. With such a configuration, it is possible to suppress the deterioration of the thermostat and the occurrence of problems due to tolerances.

[0058]

As described above in detail, according to the electric fan control device of the present invention, an excellent effect that it is possible to suppress the occurrence of problems due to an increase in the fan operation rate is achieved.

[Brief description of the drawings]

FIG. 1 is a conceptual configuration diagram illustrating a basic conceptual configuration of the present invention.

FIG. 2 is a configuration diagram illustrating a control device of the electric fan according to the first embodiment.

FIG. 3 is a flowchart illustrating an “electric fan control routine” according to the first embodiment.

FIG. 4 is an operation diagram showing a temperature change with respect to time in the first embodiment.

FIG. 5 is a diagram illustrating a temperature change rate in the first embodiment.
FIG.

FIG. 6 is a flowchart illustrating an “electric fan control routine” according to the second embodiment.

FIG. 7 is an operation diagram showing a temperature change with respect to time in the second embodiment.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Engine, 9 ... Radiator, 13 ... Cooling water passage, 1
7: Electric fan, 20: Water temperature sensor constituting water temperature detecting means, 31: Control means, correcting means, malfunction determining means, water temperature change rate detecting means, change rate comparing means, first qualifying means,
An ECU constituting the operating time detecting means, the operating time comparing means, and the second qualifying means.

Continuation of the front page (56) References JP-A-6-299852 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) F01P 7/04 F01P 11/16

Claims (5)

(57) [Claims] 1. An electric fan which is provided opposite to a radiator for cooling a cooling water in a cooling water passage of an engine including at least a radiator and which is switched between operation and stop, and detecting a temperature of the cooling water. Water temperature detecting means for performing the operation of the electric fan when the water temperature detected by the water temperature detecting means becomes higher than a first set temperature and the cooling water needs to be cooled; A control unit for stopping the electric fan when the water temperature detected by the detection unit is lower than a second set temperature and there is no need to cool the cooling water. A malfunction judgment for judging whether or not the electric fan malfunctions outside the set temperature ranges due to tolerances and deterioration of components related to the electric fan control device; Disconnecting means, and correcting means for correcting at least one of the first set temperature and the second set temperature to a higher temperature when the malfunction determining means determines that the electric fan malfunctions. A control device for an electric fan. 2. The malfunction detection means includes: a water temperature change rate detection means for detecting a change rate of water temperature when the electric fan is stopped; and an actual change rate detected by the water temperature change rate detection means. A change rate comparing means for determining whether the change rate is lower than a predetermined reference change rate; and the electric motor when the actual change rate is determined to be lower than the reference change rate by the change rate comparing means. 2. The electric fan control device according to claim 1, further comprising first certifying means for certifying that the fan malfunctions outside the range of each of the set temperatures. 3. 3. The erroneous operation determination means includes: an operation time detection means for detecting a time during which the electric fan is operated; and an actual operation time detected by the operation time detection means, wherein the actual operation time is a predetermined reference. Operating time comparing means for determining whether or not the operating time is longer than a reference time, when the operating time comparing means determines that the actual operating time is longer than a reference time, The second to be recognized as malfunctioning outside
The control device for an electric fan according to claim 1, comprising a certification unit. 4. An engine comprising at least a radiator.
The radiator to cool the cooling water in the cooling water passage of the gin.
Motor, which is provided opposite to the
And a water temperature detecting means for detecting a temperature of the cooling water , and a water temperature detected by the water temperature detecting means is a first set temperature.
And the cooling water needs to be cooled.
When the electric fan is operated and the water temperature is
The water temperature detected by the detecting means is lower than the second set temperature.
And it is no longer necessary to cool the cooling water
Control means for stopping the electric fan.
A control device for a moving fan, which detects a rate of change in water temperature when the electric fan is stopped.
Water temperature change rate detecting means, and the actual change rate detected by the water temperature change rate detecting means.
Is lower than a predetermined reference rate of change
The actual change rate is changed by a reference change rate by the change rate comparing means.
When it is determined that the temperature is lower than the first set temperature and the first set temperature,
And at least one of the second set temperatures to a higher temperature.
An electric fan, comprising:
Control device. 5. An electric fan, which is provided opposite to the radiator to cool cooling water in a cooling water passage of an engine including at least a radiator, and is operated and switched to stop, detects a temperature of the cooling water. Water temperature detecting means for performing the operation of the electric fan when the water temperature detected by the water temperature detecting means becomes higher than a first set temperature and the cooling water needs to be cooled; A control unit for stopping the electric fan when the water temperature detected by the detection unit is lower than a second set temperature and there is no need to cool the cooling water. At the time of operation for detecting the time during which the electric fan is operated
Interval detecting means, and the actual operating time detected by the operating time detecting means
Is longer than a predetermined reference time.
Operating time comparing means, and the actual operating time is determined by the operating time comparing means.
A controller for correcting at least one of the first set temperature and the second set temperature to a higher temperature when it is determined that the time is longer than the time .