JPH0635827B2 - Control device for vehicle cooling fan - Google Patents

Description

The present invention relates to a control device for a vehicle cooling fan, and more particularly to a control device for an electric fan that cools a condenser for a cooler and a radiator.

[Prior Art] Conventionally, it has been well known that an electric cooling fan is used as a radiator cooling device for an automobile, and this device maintains the cooling water of the engine at an optimum value in the vicinity of 85 to 95 ° C. When the engine cooling water temperature reaches the upper limit temperature of the set value, the motor is automatically turned on to start cooling the radiator, and when the engine cooling water temperature is cooled to the lower limit temperature of the set value, the motor is automatically turned off. ing. That is, the engine cooling water temperature is controlled in the optimum range, usually in the range of 85 to 93 ° C., by such on / off control of the electric motor.

However, such a device, when the motor is turned on,
Since the rotation speed of the cooling fan rapidly rises from 0 and a large noise is temporarily generated, this noise is very annoying to the driver of the vehicle and other occupants, which is uncomfortable.

Particularly, in such a device, the electric motor is frequently turned on and off to control the temperature of the engine cooling water to an optimum value,
Since the noise is generated each time, an effective countermeasure for it has been desired.

Therefore, an apparatus according to Japanese Patent Application No. 59-168528 has been proposed. This device has various sensors such as an outside air temperature sensor vehicle speed sensor and a water temperature sensor, etc., and constantly calculates in real time the motor applied voltage required to keep the engine cooling water at a set value based on the output of these sensors. , This voltage is constantly applied to the electric motor for driving the cooling fan.

Therefore, the cooling fan is analog-controlled so that the cooling water of the engine is always at the optimum set temperature, and the rotating speed does not fluctuate abruptly, so that it is possible to significantly reduce the noise generated. Become.

By the way, most vehicles today are provided with a cooler for cooling the vehicle interior, and in such a vehicle, it is necessary to effectively cool the condenser for the cooler in addition to the radiator.

FIG. 7 shows a cooling device in such a case.

This device is formed by arranging a radiator cooling fan 14 and a condenser cooling fan 16 in parallel with each other, and arranging a radiator 10 and a cooler 12 in tandem in a flow path of cooling air supplied by each cooling fan.
Independently of the electric motor for the radiator, when the compressor of the cooler is turned on, the electric motor of the condenser cooling fan is turned on, and when the compressor is turned off, this electric motor is also turned off.

Therefore, in such a device, each cooling fan 14, 16
As a cooling method using, it is possible to perform the following cooling operation. That is, only the cooler cooling fan 14 calculates the amount of cooling air required to control the high pressure of the cooler to a desired set value, and the amount of cooling air thus obtained is supplied from the cooler cooling fan 14 to the condenser 12. . At the same time, the cooling air volume necessary for cooling the engine cooling water passing through the radiator to a desired set value is calculated only by the radiator cooling fan 16, and the cooling air volume thus obtained is used for radiator cooling. The fan 16 is used to supply the heat to the radiator.

In this case, the number of revolutions of the cooler cooling fan 14 and the radiator cooling fan 16 is continuously analog-controlled to sufficiently reduce the generated noise as compared with the conventional ON / OFF control device. Twelve coolings can be performed.

[Problems to be Solved by the Invention] By the way, in the device shown in FIG.
Since the zeros and the condensers 12 are arranged in series with each other, the radiator 10 and the condensers 12 are cooled by both the radiator cooling fan and the condenser cooling fan, respectively. Therefore, in such a device, it is sufficient to blow the cooling air with the air volume exceeding both the radiator cooling required air volume and the condenser cooling required air volume using both the radiator cooling fan and the condenser cooling fan.

However, in the conventional technology, as described above, since the radiator cooling fan and the condenser cooling fan separately blow the radiator cooling required air volume and the condenser cooling required air volume, respectively, the radiator 10 and the condenser 12 need more than necessary. However, there is a drawback in that the extra cooling air is blown, and such extra cooling air blows energy and generates noise.

OBJECT OF THE INVENTION The present invention has been made in view of such a conventional problem, and an object thereof is to efficiently cool a radiator and a condenser for a cooler with a minimum necessary cooling air, and to reduce noise generated. An object of the present invention is to provide a vehicle cooling fan control device that can be effectively suppressed.

[Means for Solving the Problems] In the device of the present invention, a first fan driven by a first electric motor and a second fan driven by a second electric motor are arranged in parallel with each other. Then, a radiator and a cooler condenser are arranged in series in a flow path of the cooling air supplied by each cooling fan.

Then, the cooler cooling required air volume necessary for controlling the cooler high pressure to a desired set value is calculated and output by the first calculation means as the first air volume. Further, the radiator cooling required air volume necessary for cooling the temperature of the engine cooling water passing through the radiator to a desired set value is arithmetically output by the second arithmetic means as the second air volume.

Then, a value obtained by subtracting the radiator cooling required air amount from the cooler cooling required air amount is calculated and output from the third calculating means as the third air amount.

Then, the first electric motor is driven based on the output of the first computing means, and the first cooling fan blows the cooling air in an amount equal to the required air volume for cooling the condenser.

Further, the drive of the second electric motor is controlled so as to blow the cooling air volume equal to the third air volume when the third air volume which is the output of the third computing means is equal to or more than the predetermined value. Therefore,
In this case, the sum of the first air volume and the third air volume, that is, the second air volume passes through the condenser and the radiator. On the other hand, when the third air volume is less than or equal to the predetermined value, the second electric motor is stopped. Therefore, in this case, the first air volume passes through the condenser and the radiator.

Therefore, according to the present invention, the total air volume of the cooling air blown from both the first cooling fan and the second cooling fan is controlled to an optimum value necessary and sufficient for cooling both the condenser and the radiator. , There is no need to blow extra cooling air as in the past.

Therefore, according to the present invention, the condenser and the radiator can be effectively cooled with a small amount of energy, and the noise generated during the cooling can be further reduced.

[Embodiment] Next, a preferred embodiment of the present invention will be described with reference to the drawings.

FIG. 1 shows a preferred embodiment of a control device for a vehicle cooling fan according to the present invention.
First cooling fan 2 directly connected to the rotating shaft of the electric motor 20 of
2 and a second cooling fan 26 directly connected to the rotary shaft of the second electric motor 24 are arranged in parallel with each other, and a condenser 28 and a radiator are provided in a flow path of cooling air blown from each of the cooling fans 22 and 24. 30 are arranged in tandem with each other.

Then, the condenser 2 is connected to the cooling fans 22 and 24.
The cooling air is blown toward the radiator 8 and the radiator 30 to cool the condenser 22 and the radiator 30.

In the embodiment, the cooler condenser 28 is
The compressor 32, the expansion valve 34, the evaporator 36, and the temperature-sensitive cylinder 38 form a refrigerating cycle of a cooler.

Then, the refrigerant circulating in the refrigeration cycle is compressed in the compressor 14 to become a high-temperature refrigerant gas, cooled in the condenser 28 to become a liquid, and adiabatically expanded and atomized in the expansion valve 34 by the throttling action of the valve, In the evaporator 36, heat is taken from the air to be vaporized, and all become gas just before the outlet of the evaporator 36, and are absorbed again in the compressor 32.

Here, if all the refrigerant passing through the inside of the evaporator 36 becomes a gas while reaching the vicinity of its outlet,
The vaporized refrigerant is heated before reaching the outlet and the temperature at the outlet of the evaporator rises, which is not preferable. In order to prevent such a situation from occurring, the temperature near the outlet of the evaporator 36 is detected by the temperature sensing cylinder 38, and if the detected temperature rises, the expansion valve 3
4 expands the flow path of the refrigerant to increase the supply amount of the refrigerant, and when the refrigerant still remains as droplets at the outlet of the evaporator 36, the temperature sensing cylinder 38 senses the low temperature of the refrigerant and the expansion valve 34. To narrow the flow path of and reduce the supply amount of the refrigerant. In this way, the expansion valve 34 controls the supply amount of the refrigerant supplied into the evaporator 36 so that the refrigerant is completely vaporized just before its outlet.

By the way, in the refrigerant cycle of this cooler, the heat radiation amount of the condenser 28 is equal to the heat absorption amount Qe of the evaporator 36.
And the heat quantity conversion value Qp of the compression work of the compressor 32, Qe + Qp. Therefore, the heat absorption amount Qe of the evaporator 36 and the heat amount conversion Gp of the compression work of the compressor 32
The sum Qe + Qp may be cooled by the condenser 28 so that the high pressure becomes the set pressure Ps. Further, if the amount of cooling air blown to the condenser 28 is increased, the amount of heat radiation is increased and the high pressure in the refrigeration cycle is lowered, and if the amount of cooling air blown is reduced, the high pressure in the refrigeration cycle is high. Become.

Therefore, by controlling the cooling air, the condenser 2
The high pressure in 8 can be controlled to the desired set value Ps.

The radiator 30 cools the engine cooling water, and the engine cooling water is cooled by the water pump 4.
2 forcibly circulates between the radiator 30 and the engine 40.

By the way, in the device of the present invention, each cooling fan 22 and 2
Both the condenser 28 and the radiator 30 are located in the flow path of the cooling air blown from 6. Therefore, the condenser 28 is supplied with cooling air not only from the first cooling fan 22 but also from the second cooling fan 26, and the radiator 3
At 0, cooling air is blown not only from the second cooling fan 26 but also from the first cooling fan 22.

The present invention has been made paying attention to such a point, and the characteristic features thereof are the first cooling fan 22 and the second cooling fan 22.
The total value of the amount of cooling air blown from the cooling fan 26 is to control the minimum value that satisfies both the condenser cooling required air amount and the radiator cooling required air amount.

Therefore, in the device of the present invention, the first calculation means 50 causes the first air flow rate W ₁ to be the required condenser cooling air flow rate for controlling the high pressure of the cooler to the desired set value Ps.
And output as.

Then, based on the output of the first calculation means 50, the first electric motor 20 is driven and the first cooling fan 22 sends a first air amount, that is, a cooling air amount equal to the condenser cooling required air amount W ₁ .

As a result, the refrigerant passing through the condenser 28 is appropriately cooled, and the high pressure in the condenser is set to the desired set value Ps.
Controlled by.

Further, the device of the present invention calculates and outputs, as the second air amount, the radiator cooling required air amount necessary for cooling the temperature of the engine cooling water passing through the radiator 30 to the desired set value or less by the second arithmetic means 52. ing.

In the conventional technique, the second electric motor 24 is driven on the basis of the thus-obtained second air volume, and the second cooling fan 26 blows a cooling air volume equal to the radiator cooling required air volume. Therefore, the radiator 30 and the condenser 28 are blown with extra cooling air that is the sum of the condenser cooling required air volume and the radiator cooling required air volume,
This causes waste of energy and noise generation.

The characteristic feature of the present invention is that the value obtained by subtracting the first air volume W ₁ output by the first arithmetic means 50 from the _second air volume W ₂ output by the second arithmetic means 52 is the third air volume W 2. a third arithmetic means 54 which calculates the output as ₃ provided, the third drive the second electric motor 24 based on the output of the arithmetic unit 54, a third cooling air flow rate W ₃ from the second cooling fan 26 To blow air.

By doing so, the radiator 30 is blown with the radiator cooling required air volume, that is, the cooling air having a total air volume of the first air volume and the third air volume, and the engine cooling water passing through the radiator 30 is set to a predetermined set value. It can be cooled down to the following. At the same time, the condenser 2
Since the first cooling fan 22 supplies the condenser 8 with the required cooling air volume of the cooling air, the high pressure in the condenser 16 can be appropriately controlled to a desired set value.

Therefore, according to the present invention, such cooling of the condenser 28 and the radiator 30 can be performed with a smaller amount of cooling air as compared with the conventional technique, and the energy required for cooling can be saved and noise can be effectively generated. Can be suppressed.

Next, the second specific embodiment of the apparatus of the present invention described above will be described.
A description will be given based on the figure.

In this embodiment, the first to third calculating means 50, 5
2, 54 are formed by using the microcomputer 60, and the calculation of the first, second and third air volumes performed by using the microcomputer 60 will be described in detail below.

Calculation of First Air Volume In the embodiment, the condenser 28 and the radiator 30 are
Not only the cooling air blown from each cooling fan 22 and 26 but also the vehicle speed air is cooled while the vehicle is traveling.
Therefore, in the present embodiment, in consideration of the cooling of the condenser 28 by the vehicle-speed air, the value obtained by subtracting the vehicle-speed air from the amount of cooling air required for controlling the high pressure of the capacitor 28 to the desired set value Ps is required for the capacitor cooling. It is calculated as the quantity W ₁ .

Here, the required cooling air volume W ₁ is given by the following equation.

_{W 1 = K 1 {(Qe} + Qp / ts-to) -K 2 W a} b + K 3 (tc-ts) + c ·· (1) where, Qe endothermic amount in the evaporator, Qp is the compressor compression The work calorie conversion value, ts, is the refrigerant temperature with respect to the high pressure Ps in the condenser, which is uniquely obtained from the relationship between the refrigerant pressure and the evaporation (condensation) temperature.
Further, to is the outside air temperature, W is the vehicle speed, tc is the refrigerant temperature (condensation temperature) in the condenser, K ₁ , K ₂ , K ₃ , a, b, c.
Represents a constant.

In order to calculate the condenser cooling required air volume W ₁ shown in the first expression, it is necessary to first obtain the variables Qe and Qp.

(A) Heat absorption amount Qe Here, the heat absorption amount Qe to the evaporator, which is one of the variables, is obtained by the following equation from the Pi line diagram (Mollier diagram) of the refrigerant shown in FIG.

Qe = G (i _I -i _IV ) where G is the refrigerant flow rate, i _I is the enthalpy of the refrigerant at the outlet of the evaporator, and i _IV is the enthalpy of the refrigerant at the inlet of the evaporator.

Therefore, in order to calculate this Qe, the variables G, i
_It is necessary to obtain _{I 1} and i _IV respectively.

(A-1) Variable G First, in the present embodiment, the refrigerant flow rate G can be obtained based on the detection signal of the flow path meter 62 provided in the refrigerant circulation path of the cooler.

In addition to this, the refrigerant flow rate G can be obtained as follows.

That is, the high-pressure pressure Pc, the low-pressure pressure Pe of the refrigerant detected by the high-pressure pressure sensor 64, the low-pressure pressure sensor 66 provided in the refrigerant circulation path of the cooler, and the refrigerant temperature sensor 68 provided near the evaporator outlet, and the vicinity of the evaporator outlet, respectively. Using the temperature ti, the refrigerant flow rate is expressed by the following equation.

However, s: passage area of expansion valve ζ: passage flow coefficient of expansion valve γ: specific weight of refrigerant at evaporator outlet g: gravitational acceleration Since s, ζ, and γ change with Pe and tI, respectively, the above equation (2) is used. Is transformed into the following equation.

put it here, Is a function of Pe and T _I In other words, the above equation (3 ′) is converted as follows using F ₁ (x, g).

Therefore, G can be obtained by measuring and obtaining F ₁ (Pe, t _I ) in advance. (In addition, Pe,
The t _I and Pc are detected by the sensor. ) (A-2) Variable i _IV Next, the calculation for obtaining the enthalpy i _IV of the refrigerant at the inlet of the evaporator will be described based on the P-i diagrams shown in FIGS. 3 and 4.

First, the value i of the point enthalpy on the saturated liquid line AB of the refrigerant is obtained. Here, the enthalpy i at an arbitrary point x (pressure p) on the saturated liquid line is expressed by the following equation using a function.

i = F ₂ (P) (4) By the way, the enthalpy i _IV near the inlet of the evaporator is III ′ to III from the enthalpy at the III position.
A value obtained by subtracting the difference Δi _III in enthalpy, that is, i _III = i _{III ′} −Δ _III .

Here, if the temperature difference between points III 'and III is Δt _III and the specific heat of the refrigerant liquid is CL, then Δi _III = CL · Δt _III , and thus i _IV = i _III =
i _{III ′} -CL · Δt _III .

On the other hand, i _{III ′} is calculated as follows based on the equation (4) using the high pressure Pc detected by the high pressure sensor 64.

i _{III ′} = F ₂ (Pc) Therefore, the enthalpy i _IV of the refrigerant to be obtained is expressed by the following equation.

i _IV = F ₂ (Pc ₎ − CL · Δt _III (5) Here, Δt is generally around 5 ° C. and may be set to a constant value. Therefore, CL · Δt can be regarded as a constant, and as a result, i _IV can be obtained by using the equation (5).

(A-3) Variable i _I Next, the enthalpy i _I at the exit of the evaporator 12 is obtained. First, the low pressure detected by the low pressure sensor 66 is P
If the IV of the point IV 'on the saturated liquid line at e is i _{IV '} , i _{IV '} becomes i _{IV '} = F ₂ (Pe) (6) according to the equation (4).

Next, comes to seek 'Enpitaru _{i I'} of point I of the saturated vapor line and _{i I '= i IV' +} r.

Here, r is the latent heat of vaporization and is represented by r = F ₃ (P) ... (7) using the pressure P.

Since the pressure I'is the low pressure Pe detected by the low pressure sensor 66, the latent heat of vaporization at this time is r = F ₃ (Pe) (8).

On the other hand, Enpitaru i of Enpitaru _{i I} is I 'point of point I
And plus the enthalpy difference .DELTA.i _I of _{'I～I the' I, i I = i I} '+ Δi I wherein, .DELTA.i _I is the temperature of the point I _{t I} and I' the temperature of the point t
_{If I ′} , it is expressed by the following equation.

Δi _I = Cp Δt _I where Δt _I = t _I −t _{I ′} and Cp represent specific heat of constant pressure.

The t _{I 'is} a function of pressure and the evaporation temperature of the refrigerant below F
₄ (X).

t = F ₄ (P) (9) Here, if the low-pressure pressure Pe detected by the low-pressure pressure sensor 66 is substituted into the equation (9), the evaporation temperature t _{I ′} at that time is given by the following equation. Desired.

t _{I ′} = F ₄ (Pe) (10) On the other hand, the temperature t _{I at the} point _I is detected by the refrigerant temperature sensor 68, and therefore Δt _I is Δt _I = t _I −F ₄ (Pe). This is the result Δi
_I becomes Δi _I = Cp {t _I -F ₄ (Pe)} ... (11).

Therefore, the enthalpy i _I = I _{IV ′} + r + Δi _{I ′ at the} point _I is obtained from the equations (6), (8) and (11), and i _I = F ₂ (Pe) + F ₃ (Pe) + Cp {t _I -F ₄ (Pe)} ... (12)

Therefore, the heat absorption amount Qe in the evaporator 12 is obtained by substituting the formulas (3), (5), and (12) into Qe = G (i _I -i _IV ) Qe = F ₁ (Pe, t _I ) [F _{2 (Pe) + F 3 (Pe} ) + Cp {t I -F 4 (Pe)} - {F 2 (Pc) -CL · Δi III}] ·· (1
3)

(B) Compressed work amount Qp of compressor compression work First, the compression work L of the compressor 14 is given by the following equation.

L = G (n / n -1 ) P 1 V I [(P 2 / P 1) (n-1) / n-1] ···· (14) wherein, G is a refrigerant flow rate, n represents polytropic index,
Inlet of the refrigerant pressure P ₁ compressor 32, _{P 2} is the refrigerant pressure, _{V I} of the compressor 32 outlet is the refrigerant specific volume at the inlet of the compressor 32, G is Motomari than (3), n
May approximately substitute the specific heat ratio κ, and P ₁ ≈P e, P ₂
≈Pc. The V _I is represented by a relational expression of P ₁ V _I = RT ₁ , where T ₁ = 237 + t _I and R are gas constants of the refrigerant. Therefore, V ₁ is calculated by the following equation.

V ₁ = {RT ₁ / P ₁ } = {R × (237 + t _I ) / Pe} ...
(15) Therefore, by substituting the equations (3) and (15) into the equation (14), P
By substituting ₁ = Pe and P ₂ = Pc, L is expressed by the following equation.

Next, the converted heat quantity Qp of the compressor compression work L is obtained.
Here, the conversion formula of L to Qp is given by the following formula.

Qp = AL However, A is the heat equivalent of work (1 / A is the heat equivalent of heat) Therefore, from the equation (16), Qp is given by the following equation.

As described above, it is possible to calculate the condenser cooling required amount for making the high pressure of the condenser 16 a constant value Ps, that is, the first air volume W ₁ {(1), (9), (13), (1)}.

However, ts is calculated from ts = F ₄ (Ps) using the equation (9). tc is also calculated from tc = F ₄ (Pc) using the equation (9).

That is, the air volume W ₁ (first air volume) required to bring the high pressure to the constant value Ps is given by the following equation.

_{W 1 = K 1 [{(} Qe + Qp) / (F 4 (Ps) -to)} -K 2 W a} b + K 3 {F 4 (Pc) -F 4 (Ps)} + C ·· (18) where And F ₁ (x, y), F ₂ (x), F ₃ (x) F ₄
(X) is a predetermined function.

Further, Ps is a value set as the high pressure of the condenser 28, to is the outside air temperature detected by the outside air temperature sensor 70, and W
Is the vehicle speed detected by the vehicle speed sensor 72, Pe is the low pressure detected by the low pressure sensor 66, and t _I is the refrigerant temperature sensor 68.
The refrigerant temperature at the outlet of the evaporator 36, Cp is the constant pressure specific heat of the refrigerant gas, Pc is the high pressure detected by the high pressure sensor 64, CL is the specific heat of the refrigerant liquid, Δt _III is a constant value (constant), K ₁ , K ₂ , K ₃ , a, b, c are constants, and a is
The values around 0.5 and b are around 2.

Calculation of Second Air Volume Next, a required radiator cooling air volume (second air volume) required to maintain the engine cooling water temperature at a predetermined value is obtained.

(A) Apparent radiator cooling required air volume The engine cooling water temperature is theoretically determined by the balance between the amount of heat supplied to the cooling water and the amount of heat radiated from the cooling water. The amount of heat supplied to the cooling water can be obtained from both fuel injections, while the amount of heat radiated from the cooling water is mainly the outside air temperature, vehicle speed (air volume due to running wind), and rotation speed of the cooling fan (cooling fan). Wind speed).

Therefore, the air volume of the cooling air (second air volume) required to keep the temperature of the cooling water of the engine at a predetermined value is originally obtained by the following equation.

_{W 2 '= K 1' {} K 2 '× h × m / (ts -to) -K 3' × W a} b + K 4 '× (tw-tse) + C'
.. (101) However, W ₂ ′: apparently required condenser cooling air volume (air volume required to bring the cooling water temperature to the target value ts only by the cooling fan) m: fuel injection amount per unit time (fuel injection Quantity control device 7
The signal from 6 determines the fuel injection amount. ) W: vehicle speed detected by the vehicle speed sensor 72 tw: cooling water temperature detected by the water temperature sensor 74 to: outside air temperature detected by the outside air temperature sensor 70 tse: target value of cooling temperature to be kept constant h: per unit weight Calorific value of fuel (about 10200 Kcal / Kg) K ₁ ′, K ₂ ′, K ₃ ′, K ₄ ′, c ′, b, c: constants. However, a is about 0.5 and b is about 2.

However, the air heated by the condenser 28 passes through the radiator 30 because there is the radiator 30 after the condenser 28 in terms of the flow of wind velocity generated when the vehicle is traveling.

FIG. 5 shows the change of the air temperature with respect to the flow direction of the vehicle speed air at this time. Therefore, the air temperature after passing through the condenser 28 must be substituted in place of the outside air temperature to in the equation (101).

Here, the air temperature after passing through the condenser 28 is obtained by the following equation: ta = Atc + (1−A) to (102) where ta: air temperature after passing through the condenser 28 tc: at the condenser 28 It is the refrigerant temperature (condensation temperature) and is obtained from the high pressure Pc detected by the high pressure sensor 64 based on the equation (9).

to: outside air temperature A: constant Therefore, the equation (102) is ta = AF ₄ (Pc) + (1-A) to ··· (10
3) and the true air volume required for cooling the radiator (second air volume) W
₂ is calculated by the following equation.

W ₂ = K ₁ ′ [K ₂ ′ · h · m / {tse −A · F ₄ (Pc)-(1-A) to} -k ₃ ′ · W ^a ] ^b + K ₄ ′ (tw-tse) + C '··· (104) in the computation such third air volume, calculated the first air volume _{W 1} and a second air volume _{W 2,} then the second air volume _W according to the following formulas: ₂ The first air volume W ₁ is subtracted from the third air volume W ₃ to obtain the third air volume W ₃ .

W ₃ = W ₂ −W _{1 In} this way, when the first to third air volumes W ₁ , W ₂ and W ₃ are calculated, the microcomputer 60 sets the first air volume W ₁ to the capacitor motor control device. 80 and inputs the third air volume W ₃ to the radiator electric motor control device 8
Enter 2.

Accordingly, the electric motor control device 80 causes the first electric motor 20 to
By controlling the voltage applied to the cooling fan 22, the cooling fan 22 sends the cooling air of the required condenser cooling air volume W ₁ instructed by the microcomputer 60.

Similarly, the radiator electric motor control device 82 uses the second
The voltage applied to the electric motor 24 is controlled so that the cooling fan 26 blows the third air volume, that is, the cooling air of the air volume W ₃ obtained by subtracting the condenser cooling air volume (W ₁ ) from the radiator cooling air volume (W ₂ ). .

As described above, in the apparatus of this embodiment, the microcomputer 60 calculates the condenser cooling required air volume (W ₁ ) and the radiator cooling required air volume (W ₂ ) in real time, and the cooling fan 22 outputs the W ₁ from the cooling fan 22 based on the calculation result. The cooling air is blown, and the cooling fan 26 blows the cooling air (W ₂ −W ₁ ). Therefore, the condenser 28 and the radiator 30 are always favorably cooled with the optimum amount of cooling air.

Further, according to the present invention, the rotation speed of each of the electric motors 20 and 24 does not change stepwise, and the amount of cooling air to be blown is smaller than that of the conventional device, so that the noise generated is sufficient. Therefore, the occupant of the vehicle is not uncomfortable.

It should be noted that, as the electric motor control devices 80 and 82, those formed by using a transistor circuit are generally used today. In such a device, the rotation speed control of the electric motors 20 and 24 is applied and the applied voltage is duty controlled. It is suitable to carry out.

Next, the operation of the present embodiment will be described based on the flowchart shown in FIG.

When the device of this embodiment is operated, the microcomputer 60 first causes the high pressure sensor 64 and the low pressure sensor 6 to operate.
6, the detection signals from the refrigerant temperature sensor 68, the vehicle speed sensor 72, the outside air temperature sensor 70, and the water temperature sensor 74 are read, and further the fuel injection amount information output from the fuel injection control device 76 is read.

When this reading operation is completed, the refrigerant flow rate G is calculated using the third equation based on the next read data, and the heat absorption amount Qe is calculated based on the nineteenth equation.
The calorie conversion value Qp of the compression work of the compressor 28 is calculated based on the diagram.

Then, on the basis of each calculated value and detection data thus obtained, the condenser cooling required air volume W ₁ is calculated based on the above equation 8, and the first air volume W ₁ thus obtained is preset. Compare with a predetermined reference value A ₁ .

Then, as a result of performing this comparison operation, W ₁ is equal to the reference value A ₁
In the above case, the first air volume W _{1 is set} to the motor control device 80.
And the first air volume calculated from the cooling fan 22,
That is, the cooling air of the required cooling air volume W ₁ is blown.

When W ₁ is equal to or less than the reference value A ₁ as a result of the comparison operation, the reference value A ₂ set to a value smaller than A ₁ is compared with W ₁ .

As a result, when W ₁ is A ₂ or less, the capacitor 2
In order to set the high pressure of 8 to the set pressure Ps, the fan 22
It is determined that the air is not required to be blown, and the voltage applied to the electric motor 20 is turned off to stop the rotation of the electric motor.

When W ₁ is larger than the reference value A ₂ , W ₁ is A
_It is an intermediate value between ₁ and A ₂ , and at this time, the rotation of the electric motor 20 is maintained as it is. That is, if the voltage is currently applied to the electric motor 20, the microcomputer 60 continues to apply the voltage. Further, if the electric motor 20 is currently stop-controlled, the electric motor 20 is continuously stopped and controlled.

The reference values A ₁ and A ₂ are hysteresis, and prevent the electric motor 20 from performing on / off hatching operations by a slight change in the first air volume W ₁ .

Next, in the device of the present embodiment, the radiator cooling required air volume necessary for controlling the engine cooling water temperature to the set value ts by only the other cooling fan 26, that is, the second air volume W _{2 is set} to the expression 104 described above. Then, the first air volume W ₁ is subtracted from the _second air volume W ₂ thus obtained to obtain the third air volume W ₃ .

Then, the third air volume W ₃ thus obtained is compared with a predetermined reference value B ₁ set in advance.

At this time, when W ₃ is B ₁ or more, the third air volume is input to the electric motor control device 82, and the cooling fan 26 outputs the third air amount.
The cooling air having the air flow rate W ₃ is blown.

If the calculated third air volume W ₃ is smaller than the reference value B ₁ , then the reference value B ₂ set to a value smaller than B ₁ is compared with W ₃ .

At this time, when W ₃ is B ₂ or less, when cooling the engine cooling water temperature to the set temperature ts, it is determined that it is not necessary to blow the cooling air from the other cooling fan 26, and the electric motor 24 is stopped and controlled. . When W ₂ is B ₂ or more, that is, when W ₃ has a value between B ₁ and B ₂ , the electric motor 24 is controlled in the current state. That is, if a predetermined voltage is currently applied to the electric motor 24, the current voltage continues to be applied, and if the electric motor 24 is currently stopped, the stop control is continued. become.

Here, B ₁ and B ₂ are hysteresis, and prevent the electric motor 24 from performing an on-off hatching operation by a slight change in the third air volume W ₃ .

As described above, the apparatus according to the present embodiment repeats the above-described series of operations in real time, and blows the cooling air of an appropriate air volume from each of the cooling fans 22 and 26.

[Effects of the Invention] As described above, according to the present invention, the condenser and the radiator can be effectively cooled with a smaller amount of air flow as compared with the conventional device, and as a result, the energy for driving the electric motor can be reduced. It is possible to reduce the noise and effectively prevent the generation of noise.

[Brief description of drawings]

FIG. 1 is a circuit diagram showing a preferred embodiment of the device according to the present invention, FIG. 2 is a circuit diagram showing a specific configuration of the device shown in FIG. 1, and FIGS. 3 and 4 are Pi. Diagram, FIG. 5 is an explanatory diagram showing the relationship between the flow direction of vehicle speed wind and air temperature, FIG. 6 is a flow chart diagram showing the operation of the apparatus of this embodiment, and FIG. 7 is a layout of radiators and condensers. FIG. 20 ... 1st electric motor 22 ... 1st cooling fan 24 ... 2nd electric motor 26 ... 2nd cooling fan 28 ... Condenser 30 ... Radiator 50 ... 1st calculating means 52 ... 1st Second computing means 54 ... Third computing means 60 ... Microcomputer

Claims (2)

[Claims] 1. A first cooling fan driven by a first electric motor and a second cooling fan driven by a second electric motor are arranged in parallel with each other, and cooling is provided by each cooling fan. A controller for a vehicle cooling fan that cools the radiator and the condenser by controlling the voltage applied to the first electric motor and the second electric motor by arranging a radiator and a cooler condenser in tandem in an air flow path. In addition, the first calculation means for calculating and outputting the condenser cooling required air volume necessary for controlling the high pressure of the cooler to a desired set value as the first air volume, and the engine cooling water temperature passing through the inside of the radiator Second calculating means for calculating and outputting as a second air volume the radiator cooling required air volume necessary for cooling to a desired set value; and the first air volume from the second air volume. Third calculation means for calculating and outputting a value obtained by subtracting the amount as a third air quantity, and based on the output of the first calculation means, a cooling air quantity equal to the first air quantity is blown from the first cooling fan. First
First electric motor control means for controlling the drive of the electric motor, and when the third air quantity output from the third computing means is equal to or more than a predetermined value, a cooling air quantity equal to the third air quantity is blown. A control device for a vehicle cooling fan, which controls driving of the second electric motor and stops the second electric motor when the third air volume is equal to or less than a predetermined value. 2. The apparatus according to claim 1, wherein the apparatus detects a high pressure pressure sensor for detecting a high pressure in the refrigerant circulation path of the cooler, and a low pressure pressure in the refrigerant circulation path of the cooler. A low pressure sensor, a refrigerant temperature sensor that detects the refrigerant temperature near the evaporator outlet in the cooler refrigerant circulation path, an outside air temperature sensor that detects the outside air temperature of the vehicle, a water temperature sensor that detects the engine cooling water temperature, and a vehicle speed And a vehicle speed sensor for detecting the high speed pressure, the low pressure in the refrigerant circulation path of the cooler output from the respective sensors,
A first air volume is calculated and output based on the refrigerant temperature, the vehicle speed of the vehicle, and the outside air temperature, and the second calculating means outputs the vehicle outside air temperature, the engine cooling water temperature, the vehicle speed, and the fuel injection control. The second based on the signal of the fuel injection amount output from the device
A control device for a vehicle cooling fan, characterized in that it calculates and outputs the air flow rate.