JP3010888B2 - Vehicle cooling fan speed controller - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle in which cooling air is passed by a cooling fan to a radiator of an internal combustion engine and a condenser of an air conditioner, and more particularly to a cooling fan rotation for controlling the rotation speed of the cooling fan. The present invention relates to a numerical controller.

[0002]

2. Description of the Related Art In a motor vehicle, a radiator of an internal combustion engine and a condenser of an air conditioner are cooled by the same cooling fan through cooling air.

[0003] In this case, the operation of the cooling fan is mainly controlled in accordance with the change in the refrigerant pressure of the air conditioner. Intermittent control for intermittent operation or stepless control for continuously changing the number of revolutions according to a change in refrigerant pressure has been considered.

[0004] By the way, in the most frequent driving of an automobile in an urban area, the stepless control method can reduce energy loss and reduce fuel consumption as compared with the intermittent control method. In some cases, a stepless control method is employed.

That is, in the case of the intermittent control system, the cooling fan operates intermittently, so that the refrigerant pressure of the air conditioner fluctuates. Therefore, not only does the load on the compressor of the air conditioner increase, so that the compressor drive loss increases, but also the fuel injection amount of the internal combustion engine during idle speed control increases, resulting in a large energy loss.

On the other hand, in the case of the stepless control system, since the number of revolutions of the cooling fan is set in accordance with the refrigerant pressure, the water temperature, etc., the fluctuation of the refrigerant pressure is extremely small, and stable control is performed. It is. Therefore, the load on the compressor of the air conditioner is reduced, so that the compressor drive loss can be reduced, and the fuel injection amount of the internal combustion engine during idle speed control can also be reduced, thereby reducing fuel consumption.

[0007]

When a stepless control system is adopted as in the prior art, for example, a running operation such as climbing a hill, which runs on an internal combustion engine after running in a midsummer city area where cooling performance is the strictest, is performed. Thus, there is a problem that the temperature of the cooling water of the internal combustion engine rapidly rises and the internal combustion engine is overheated during traveling.

That is, when driving in an urban area in the midsummer, when the cooling performance is severe, the heat load on the refrigerant pressure of the air conditioner is generally stricter than the cooling water of the internal combustion engine. Since it is normal to operate at a selected number, the radiator of the internal combustion engine is sufficiently cooled and the temperature of the cooling water has not increased so much.

On the other hand, in the stepless control system, as compared with the intermittent control system, the rotation speed of the cooling fan is often equal to the refrigerant pressure and does not reach the maximum rotation speed. Therefore, the radiator of the internal combustion engine is in a state where the temperature of the cooling water has risen from the time of the intermittent control. In such a state, when the running of the internal combustion engine becomes the most severe, such as climbing a hill, the temperature of the cooling water of the internal combustion engine sharply rises. Even if you switch to driving,
The cooling is too late and the internal combustion engine overheats.

Incidentally, in order to solve the above-mentioned problem of the stepless control method, it is conceivable to set a control pattern such that the rotation speed of the cooling fan increases from a low refrigerant pressure region. However, with such a setting, the cooling fan is always operated at a rotational speed that generates excessive cooling air during the most frequent urban area running, and there is a problem that the fuel consumption reduction effect is reduced.

The present invention has been made in view of the above circumstances, and an object thereof is to reduce fuel consumption and improve cooling performance even when a cooling fan is used to pass cooling air through a radiator of an internal combustion engine and a condenser of an air conditioner. An object of the present invention is to provide a cooling fan rotation speed control device for a vehicle that can achieve both improvement and improvement.

[0012]

According to the present invention, there is provided an apparatus for controlling the number of revolutions of a cooling fan of a vehicle, wherein cooling air is passed by a cooling fan to a radiator of an internal combustion engine and a condenser of the air conditioner in the vehicle. A pressure sensor that detects the refrigerant pressure of the cooling fan, stores pattern data in which the relationship between the refrigerant pressure and the rotation speed changes steplessly, and determines the rotation speed of the cooling fan from the pattern data according to the detected refrigerant pressure of the pressure sensor. The control means calculates an average refrigerant pressure per unit time based on the refrigerant pressure detected from the pressure sensor, and compares the average refrigerant pressure with a preset set pressure. Further, the feature is that the pattern data is changed to pattern data having a different rate of change from the pattern data according to the comparison result.

[0013]

According to the cooling fan rotation speed control device for a vehicle of the present invention, the control means controls the rotation of the cooling fan according to the refrigerant pressure based on the pattern data in which the relationship between the refrigerant pressure and the rotation speed changes steplessly. Since the number is set, stable control with small fluctuations in refrigerant pressure can be performed, and fuel efficiency can be reduced.

The control means calculates an average refrigerant pressure per unit time, compares the average refrigerant pressure with a set pressure, and, based on a result of the comparison, converts the pattern data having a different rate of change from the pattern data. Since the pattern data is changed, even if the refrigerant pressure is the same, the rotation speed of the cooling fan becomes different from that of the previous pattern data, so that the cooling performance can be improved.

[0015]

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

First, the overall schematic configuration will be described with reference to FIG.

Radiator 1 for an internal combustion engine of an automobile as a vehicle
Is disposed in front of the engine room, and a condenser 2 of a refrigeration cycle of the air conditioner is provided in front of the radiator 1.
Are arranged. Further, a cooling fan 5 including a fan 3 and a drive motor 4 for rotating the fan 3 is disposed behind the radiator 1.

The microcomputer 6 serving as control means includes:
Each of the input ports has a pressure sensor 7 for detecting the pressure of the refrigerant flowing through the refrigeration cycle of the air conditioner and a temperature sensor 8 for detecting the temperature of the cooling water for cooling the internal combustion engine. Each detection signal is provided.

The microcomputer 6 outputs an invar drive signal from an output port and supplies it to the inverter 9. The inverter 9 uses the battery 10 as a DC power supply and indicates the inverter drive signal supplied from the microcomputer 6. An AC power having an output frequency is output and supplied to the drive motor 4 of the cooling fan 5. Therefore, the drive motor 4 is connected to the inverter 9
Is rotated at a rotational speed proportional to the output frequency of the AC power supplied from the power supply.

Next, the operation of this embodiment will be described with reference to FIGS. 1 and 3 to 5.

When the operation of the air conditioner is started (started), the microcomputer 6 proceeds to the processing step S1 of "PHI ← K". In this processing step S1, the microcomputer 6 sets the temporary set pressure PHI to a predetermined fixed set value K, and shifts to the next processing step S2 of “PH ← PHI”.

In the processing step S2, the microcomputer 6 sets the tentatively set pressure PHI to the maximum rotational speed pressure PH. As shown in FIG. 3, the ROM of the microcomputer 6 stores data for setting the rotation speed R to the minimum rotation speed RL when the refrigerant pressure P is at the minimum rotation speed pressure PL, and stores the data for the maximum rotation speed RH. It is remembered. Therefore, in the processing step S2, the microcomputer 6 reads the ROM
, The data of the minimum rotation speed PL, the minimum rotation speed RL, and the maximum rotation speed RH are read out and stored in the RAM, and the maximum rotation speed pressure PH (= K) is stored in the RAM.

As a result, the RA of the microcomputer 6
As shown in FIG. 3, M has a minimum rotation speed RL at the minimum rotation speed medium pressure PL and a maximum rotation speed RH at the maximum rotation speed pressure PH (= K). As a result, the basic pattern data La of the stepless control system in which the number of rotations changes linearly is stored.

The microcomputer 6 then executes a subroutine S for "determination and operation of the number of revolutions of the cooling fan".
3 in which the refrigerant pressure of the refrigeration cycle of the air conditioner is read from the detection signal of the pressure sensor 7 and the refrigerant pressure of the cooling fan 5 is determined from the detected refrigerant pressure based on the basic pattern data La in FIG. Set the side rotation speed.

The ROM of the microcomputer 6 stores pattern data of the water temperature H and the rotation speed R as shown in FIG. In FIG. 4, HL indicates the lowest rotation speed water temperature, and HH indicates the highest rotation speed water temperature.

Then, in subroutine S3, the microcomputer 6 reads the temperature of the cooling water of the internal combustion engine from the detection signal of the temperature sensor 8, and converts the pattern data of FIG. 4 from the read detected temperature, that is, the detected water temperature. Based on this, the rotation speed of the cooling fan 5 on the water temperature side is set. Then, the microcomputer 6 compares the refrigerant pressure side rotation speed and the water temperature side rotation speed set as described above, and gives priority to the higher rotation speed as the execution rotation speed. And outputs an inverter drive signal indicating an output frequency corresponding to.

As a result, the inverter 9 supplies AC power having an output frequency corresponding to the actual rotation speed to the drive motor 4 of the cooling fan 5, and the drive motor 4
The fan 3 is driven by rotating at the above-described execution speed. Therefore, the air sucked from the front side of the engine room by the blowing action of the fan 3 causes the condenser 2 and the radiator 1
Is discharged to the rear side, whereby the condenser 2 and the radiator 1 are cooled by the cooling air.

In the subroutine S3, the microcomputer 6 sets the higher rotational speed of the refrigerant pressure side rotational speed and the water temperature side rotational speed so as to give priority to the execution rotational speed. According to the experiments so far, it has been found that mainly the refrigerant pressure side rotational speed is prioritized and set as the execution rotational speed.

The microcomputer 6 then proceeds to a subroutine S4 of "calculation of the average refrigerant pressure PT", where the microcomputer 6 reads the detection signal from the pressure sensor 7 over a short unit time ΔT as shown in FIG. , Calculates the average value of the detected detected refrigerant pressures, and calculates
T is stored in the RAM, and “PT ≧ P2?”
The process moves to step S5.

As shown in FIG. 3, the ROM of the microcomputer 6 stores a lower limit set pressure P1 and an upper limit set pressure P3.
And the reference set pressure P2, and the microcomputer 6 compares the set pressures P1 to P3 with the above-described average refrigerant pressure PT as described below.

In this case, the average refrigerant pressure PT is between the lower limit set pressure P1 and the reference set pressure P2 (P1 <PT <) when the vehicle is running in an urban area, which is the most frequent of the automobiles.
P2).

In the determination step S5, the microcomputer 6 determines whether or not the average refrigerant pressure PT is equal to or higher than the reference set pressure P2 (PT ≧ P2). (PT <P2), and proceeds to the determination step S6 of “PT ≦ P1?”. The microcomputer 6 determines in this determination step S6
In this case, the average refrigerant pressure PT is lower than or equal to the lower limit set pressure P1 (PT
≦ P1), and when traveling in an urban area,
Here, the determination is "NO"(PT> P1), and the process returns to the processing step S1.

The microcomputer 6 performs the following steps S1, S2, subroutines S3, S4, and step S5.
And S6 are repeated. Therefore, the basic pattern data La shown in FIG. 3 is always stored in the RAM of the microcomputer 6, and the rotation speed of the cooling fan 5 is set based on the basic pattern data La. Will be.

On the other hand, when driving in an urban area in midsummer, which is the most severe for the cooling performance of the automobile, the average refrigerant pressure PT also becomes large and exceeds the reference set pressure P2.

In such a case, the microcomputer 6 determines “YES” when the process proceeds to the determination step S5 of “PT ≧ P2?”, And determines “PH1 ← PH1-Δ
P ", the process proceeds to step S7. In this processing step S7, the microcomputer 6 sets the temporary set pressure PH.
Then, the constant pressure ΔP is subtracted from 1 to obtain a new temporarily set pressure PH1, and then the process proceeds to a judgment step S8 of “PH1 ≦ P1?”.

In this determination step S8, the microcomputer 6 determines whether or not the new temporary set pressure PH1 is lower than or equal to the lower limit set pressure P1 (PH1 ≦ P1).
If it is determined to be "NO"(PH1> P1), the process returns to the processing step S2, and the maximum rotational speed pressure PH is set as the new temporary setting pressure PH1.

As a result, when the microcomputer 6 next proceeds to the subroutine S3, the new maximum rotational speed pressure PH (= K-ΔP) is stored in the RAM. As shown, the change pattern data Lb indicating the new maximum rotational speed RH at the new maximum rotational speed pressure PH is stored.

Accordingly, the microcomputer 6 thereafter repeats the subroutine S4, steps S5, S6, S2 and subroutine S3, so that the execution speed of the cooling fan 5 is set based on the changed pattern data Lb. Thus, as compared with the case of the basic pattern data La, the number of rotations of the cooling fan 5 becomes higher even at the same refrigerant pressure.

When the average refrigerant pressure PT is equal to or higher than the reference set pressure P2 (PT ≧ P2) also by the rotation speed of the cooling fan 5 based on the above-mentioned changed pattern data Lb, the microcomputer 6 sets “PT ≧ P2?” Judgment step S
5 is determined as “YES” and “PH1 ← P
The process moves to the processing step S7 of “H1-ΔP”. In this processing step S7, the microcomputer 6 subtracts the constant pressure ΔP from the temporary setting pressure PH1 changed as described above to obtain a new temporary setting pressure PH1 (= K−2ΔP). The process proceeds to the determination step S8 of “PH1 ≦ P1?”.

In this determination step S8, the microcomputer 6 determines whether or not the new temporary set pressure PH1 is equal to or lower than the lower limit set pressure P1 (PH1 ≦ P1), and “NO” (PH1> P1). When it is determined, the process returns to the processing step S2, and the maximum rotational speed pressure PH is set as the new temporary setting pressure PH1.

As a result, when the microcomputer 6 next proceeds to the subroutine S3, the new maximum rotational speed pressure PH (= K−2ΔP) is further stored in the RAM. As shown in the figure, the change pattern data Lc indicating the maximum rotation speed PH at the new maximum rotation speed pressure RH is stored.

Accordingly, the microcomputer 6 thereafter repeats the subroutine S4, steps S5, S6, S2 and subroutine S3, so that the execution speed of the cooling fan 5 is set based on the changed pattern data Lc. That is, as compared with the case of the change pattern data Lb, the rotation speed of the cooling fan 5 becomes higher even with the same refrigerant pressure.

If the average refrigerant pressure PT is equal to or higher than the reference set pressure P2 (PT ≧ P2) also by the rotation speed of the cooling fan 5 based on the above-mentioned changed pattern data Lc, the microcomputer 6 proceeds to steps S5, S7 and S8. Is repeated to obtain a value obtained by sequentially subtracting the maximum rotational speed pressure PH by a constant pressure ΔP.

In such a process, the temporarily set pressure P
When H1 becomes equal to or lower than the lower limit set pressure P1 (PH1 ≦ P1), the microcomputer 6 determines in step S
In step S8, "YES" is determined, and the process proceeds to "PH1 ← P1" processing step S9. In this processing step S9, the microcomputer 6 sets the temporary setting pressure PH1 to the lower limit setting pressure P1, and returns to the processing step S2.

Therefore, after the microcomputer 6 sets the maximum rotational speed pressure PH to the lower limit set pressure P1, the microcomputer 6 changes the pattern data even if the average refrigerant pressure PT is higher than the upper limit set pressure P2 (PT ≧ P2). There is no.

On the other hand, for example, when the rotation speed of the cooling fan 5 is set based on the change pattern data Lc, the outside air temperature or the amount of solar radiation decreases, and the average refrigerant pressure PT becomes lower than the lower limit set pressure P1 (PT When ≦ P1), this indicates that the cooling capacity of the cooling fan 5 is excessive.

Therefore, when the microcomputer 6 proceeds to the determination step S6, it determines "YES" here and performs the processing of "PH1 ← PH1 + ΔP" in the processing step S10.
Move to In this processing step S10, the microcomputer 6 adds the constant pressure ΔP to the temporary setting pressure PH1 to obtain a new temporary setting pressure PH1, and then proceeds to the next step of determining “PH1 ≧ P3?” .

In this determination step S11, the microcomputer 6 determines whether or not the new temporary set pressure PH1 is equal to or higher than the upper limit set pressure P3 (PH1 ≧ P3).
If it is determined to be "NO" (PH1 <P3), the process returns to the processing step S2, and the maximum rotational speed pressure PH is set as the new temporary setting pressure PH1.

As a result, when the microcomputer 6 next proceeds to the subroutine S3, the new maximum rotation speed pressure PH (= K-ΔP) is stored in the RAM. Will be stored.

Accordingly, the microcomputer 6 thereafter repeats the subroutine S4, steps S5, S6, S2 and subroutine S3, so that the execution speed of the cooling fan 5 is set based on the changed pattern data Lb. That is, as compared with the case of the change pattern data Lc, the rotation speed of the cooling fan 5 becomes lower even with the same refrigerant pressure.

When the average refrigerant pressure PT is equal to or lower than the lower limit set pressure P1 (PT ≦ P1) also by the rotation speed of the cooling fan 5 based on the above-mentioned changed pattern data Lb, the microcomputer 6 sets “PT ≦ P1?” Judgment step S
6 is determined to be “YES” and “PH1 ← P
H1 + ΔP ”is transferred to the processing step S10. In this processing step S10, the microcomputer 6 sets the temporarily set pressure PH1 changed as described above to a fixed pressure ΔP
Is added to obtain a new temporary setting pressure PH1 (= K). Then, the process returns to the processing step S2 via the determination step S11, and the maximum rotational speed pressure PH is set as the new temporary setting pressure PH1.

As a result, when the microcomputer 6 shifts to the subroutine S3 next, the new maximum rotational speed pressure PH (= K) is stored in the RAM.
Stores the basic pattern data La described above.

When the average refrigerant pressure PT is equal to or lower than the lower limit set pressure P1 (PT ≦ P1) also by the rotation speed of the cooling fan 5 based on the basic pattern data La, the microcomputer 6 proceeds to steps S6, S10 and S11. Is repeated to increase the maximum rotational speed pressure PH by a constant pressure ΔP.

In such a process, the temporarily set pressure P
When the pressure H1 is equal to or higher than the upper limit set pressure P3 (PH1 ≧ P3), the microcomputer 6 determines in the determination step S
In step S11, "YES" is determined, and the process proceeds to step S12 of "PH1 ← P3". The microcomputer 6
In this processing step S12, the temporary set pressure PH1 is set to the upper limit set pressure P3, and the process returns to the processing step S2.

Therefore, after setting the maximum rotational speed pressure PH to the upper limit set pressure P3, the microcomputer 6 changes the pattern data even if the average refrigerant pressure PT is lower than the lower limit set pressure P1 (PT ≦ P1). There is no.

As described above, in this embodiment, the microcomputer 6 calculates the average refrigerant pressure PT per unit time of the refrigeration cycle of the air conditioner, and this is between the lower limit set pressure P1 and the reference set pressure P2. In this case, the rotation speed of the cooling fan 5 is set according to the refrigerant pressure based on the basic pattern data La of the stepless control in which the relationship between the refrigerant pressure P and the rotation speed R changes linearly.

Thus, in the case of the most frequent running of the automobile in the city, the rotation speed of the cooling fan 5 is set to a rotation speed corresponding to the refrigerant pressure.
Therefore, the refrigerant pressure is controlled to be stable at a low level with little fluctuation, so that the load on the compressor of the refrigeration cycle is reduced, and the fuel efficiency can be reduced.

When the average refrigerant pressure PT becomes equal to or higher than the reference set pressure P2, the microcomputer 6 sequentially lowers the maximum rotational speed pressure PH by a constant pressure ΔP and changes the rate of change from the basic pattern data La. That is, the rotation speed is changed to the change pattern data Lb, Lc or the like having a large inclination, and the rotation speed of the cooling fan 5 is set according to the refrigerant pressure based on the change pattern data Lb, Lc or the like.

Thus, when driving in a city in the midsummer summer when the cooling performance of the automobile is severe, the rotation speed of the cooling fan 5 is increased even at the same refrigerant pressure as in the case of the control by the basic pattern data La. Therefore, the radiator 1 can be sufficiently cooled. Therefore, even when the internal combustion engine shifts to climbing hills, which is a heavy burden, the internal combustion engine does not overheat. I can figure it out.

In the above embodiment, the basic pattern data La and the changed pattern data Lb, Lc are set and stored in the RAM by the operation of the microcomputer 6. For example, the magnitude of the average refrigerant pressure PT May be stored in the ROM in advance, and these may be selected and read out and stored in the RAM.

In the above embodiment, the pattern data of the refrigerant pressure P and the number of revolutions R are linearly changed.
For example, it may be a stepless one that changes in a curve.

[0062]

As described above, the cooling fan rotation speed control apparatus for a vehicle according to the present invention, in accordance with the refrigerant pressure of the air conditioner, is based on the pattern data in which the relationship between the refrigerant pressure and the rotation speed changes steplessly. While setting the number of rotations of the cooling fan, the average refrigerant pressure per unit time was compared with the set pressure, and based on the comparison result, the pattern data was changed to pattern data having a different rate of change. Therefore, it is possible to achieve both the effects of reducing fuel consumption and improving cooling performance.

[Brief description of the drawings]

FIG. 1 is a flowchart illustrating an operation of an embodiment of the present invention.

FIG. 2 is a diagram showing an overall schematic configuration.

FIG. 3 is a diagram showing pattern data of refrigerant pressure-rotation speed.

FIG. 4 is a diagram showing pattern data of water temperature-rotation speed.

FIG. 5 is a refrigerant pressure characteristic diagram for explaining the operation.

[Explanation of symbols]

In the drawing, 1 is a radiator, 2 is a condenser, 5 is a cooling fan, 6 is a microcomputer (control means), 7 is a pressure sensor, 8 is a temperature sensor, and 9 is an inverter.

Continuation of front page (58) Field surveyed (Int.Cl. ⁷ , DB name) F01P 7/04

Claims (1)

(57) [Claims] 1. A vehicle in which cooling air is passed by a cooling fan to a radiator of an internal combustion engine and a condenser of an air conditioner in a vehicle, comprising: a pressure sensor for detecting a refrigerant pressure of the air conditioner; Control means for storing pattern data in which the relationship changes steplessly, and for setting the number of revolutions of the cooling fan from the pattern data in accordance with the refrigerant pressure detected by the pressure sensor, the control means Calculate the average refrigerant pressure per unit time based on the detected refrigerant pressure of the sensor, compare the average refrigerant pressure with a preset pressure, and change the pattern data according to the comparison result. A cooling fan rotation speed control device for a vehicle, wherein the control device is configured to change to pattern data having different rates.