JPH06102978B2 - Control device for vehicle cooling fan - Google Patents

Description

The present invention relates to a controller for a vehicle cooling fan, and more particularly to a controller for an electric fan that cools a condenser for coolers 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, there is a problem that the step noise is very annoying to the driver of the vehicle and other occupants and causes discomfort. It was

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

As a cooling device in such a case, as shown in FIG. 7, a condenser and a radiator are arranged in parallel with respect to the air flow, and each is cooled by an electric fan. As shown in FIG. Some are arranged in series with the flow of air.

The apparatus shown in FIG. 7 is effective when the condenser and the radiator are arranged in parallel with respect to the air flow, and the cooling of the condenser and the cooling of the radiator are independently performed by the respective cooling fans.

Further, in the apparatus shown in FIG. 8, a radiator cooling fan 14 and a condenser cooling fan 16 are arranged in parallel with each other, and a radiator is provided in a flow path of cooling air supplied by each cooling fan.
It is formed by arranging 10 and the cooler 12 in series with each other. Then, independently of the electric motor for the radiator, the electric motor of the condenser cooling fan is turned on when the compressor of the cooler is turned on, and this electric motor is also turned off when the compressor is turned off.

[Problems to be Solved by the Invention] Conventional Problems However, in the conventional technology, the condenser is also cooled when the electric fan for cooling the radiator is rotating. Therefore, even if the condenser cooling fan is rotated at a lower speed, the cooler high pressure can be set to the set pressure. Conversely, when the cooling fan that cools the condenser is rotating, the radiator is also cooled.

Therefore, even if the cooling fan for cooling the radiator is rotated at a lower speed, the engine cooling water temperature can be maintained at the set temperature.

Therefore, the radiator 10 and the condenser 12 are blown with extra cooling air more than they need, and such extra cooling air blowing causes energy waste and noise generation. There was a flaw.

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, the radiator and the cooler condenser are arranged in series with each other in the flow path of the cooling air supplied by each cooling fan.

Then, the air volume for keeping the engine cooling water temperature at the set temperature and the air volume necessary for keeping the cooler high pressure at the set pressure are calculated, and the two are compared. Then, of the two, the larger air volume is selected so that the sum of the air volumes by the two cooling fans becomes the air volume by the rotation of the two cooling fans.

This allows the engine cooling water temperature to be maintained at the set temperature and the cooler high pressure to be maintained at the set pressure even when the condenser and the radiator are arranged in series with respect to the air flow. Energy can be effectively used with a limited air volume.

Further, the rotation speeds of the two cooling fans can be continuously and effectively controlled, and the generation of noise due to the abrupt change of the rotation speeds can be prevented.

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

FIG. 1 is a configuration explanatory view of a control device for a vehicle cooling fan according to the present invention.

In the figure, a first cooling fan 22 directly connected to the rotary shaft of the first electric motor 20 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. A condenser 28 and a radiator 30 are arranged in series in a flow path of cooling air blown from the cooling fans 26, 26.

Then, by blowing cooling air to the condenser 28 and the radiator 30, the condenser 22 and the radiator 30.
Is cooling.

In the embodiment, the condenser 28 for the cooler includes the compressor 32, the expansion valve 34, and the evaporator.
The cooler refrigeration cycle is formed together with the temperature sensing cylinder.

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

Here, if the refrigerant passing through the inside of the evaporator 36 becomes all gas while reaching the vicinity of its outlet, the vaporized refrigerant is heated until it reaches the outlet, and the temperature at the evaporator outlet rises. Not preferable.

To prevent this from happening, the evaporator 36
The temperature near the outlet of the temperature sensor 38 is detected by the temperature sensitive tube 38, and when the detected temperature rises, the flow path of the expansion valve 34 is expanded to increase the supply amount of the refrigerant, and the refrigerant is still present at the outlet of the evaporator 36. When a large amount of liquid drops remain, the temperature sensing cylinder 38 senses the low temperature of the refrigerant and narrows the flow path of the expansion valve 34 to reduce the amount of the refrigerant supplied.

In this way, the expansion valve 34 controls the supply amount of the refrigerant supplied into the evaporator 36 so that all the refrigerant is vaporized just before its outlet.

In the refrigeration cycle of this cooler, the heat radiation amount of the condenser 28 is Qe + Qp, which is the sum of the heat absorption amount Qe of the evaporator 36 and the heat amount conversion value Qp of the compression work of the compressor 32. Therefore, the sum Qe + Qp of the heat absorption amount Qe of the evaporator 36 and the heat amount conversion Qp of the compression work of the compressor 32 may be cooled by the condenser 28 so that the high pressure becomes the set pressure Ps. If the amount of cooling air to the condenser 28 is increased,
The amount of heat released increases, the high-pressure pressure in the refrigeration cycle decreases, and conversely, if the amount of cooling air blown is reduced, the high-pressure pressure in the refrigeration cycle increases. Therefore, by controlling the cooling air, the high pressure in the condenser 28 can be controlled to the desired set value Ps.

The radiator 30 cools the engine cooling water, and the engine cooling water is forcibly circulated between the radiator 30 and the engine 40 by the water pump 42.

By the way, in the device of the present invention, both the condenser 28 and the radiator 30 are located in the flow path of the cooling air by the cooling fans 22 and 26.

Therefore, the condenser 28 is cooled not only by the second cooling fan 22 but also by the first cooling fan 26, and the radiator 30 is cooled not only by the first cooling fan 26 but also by the second cooling fan 22. .

Further, the fuel injection amount information is wired so as to be input to the arithmetic circuit 44 from the fuel injection amount control device 43 that controls the fuel injection amount of the engine 40. Further, in an appropriate place of the vehicle, an outside air temperature sensor 46 for detecting the outside air temperature, a vehicle speed sensor 48 for detecting the vehicle speed, a water temperature sensor 50 for detecting the engine cooling water temperature, a high pressure sensor 52 for detecting the high pressure of the cooler, and a cooler A low pressure sensor for detecting the low pressure and a refrigerant temperature sensor 56 for detecting the refrigerant temperature near the evaporator outlet are arranged.

Then, motor control devices 58, 60 are provided to control the cooling fans 22, 26. This controls the voltage applied to the electric motors 20 and 24 of the cooling fans 22 and 26 based on the command from the arithmetic circuit 44. The motor control device 58, 60 may be like a transistor. In this case, pulse duty control is performed, and the motor 20, 20, 2 is controlled by changing the duty ratio.
The voltage applied to 4 can be controlled.

Further, the arithmetic unit 44 may be something like a microcomputer, and performs control as will be described later. In addition, regarding the cooler of the vehicle, in general, most of the coolers are mounted on the market after the vehicle is manufactured or after being marketed. If it does not have a cooler, it is cooled by one cooling fan 22.
Also, when equipped with a cooler, the arithmetic circuit 44 is previously provided with terminals for newly required sensors, that is, the high pressure sensor 52, the low pressure sensor 54, and the refrigerant temperature sensor 56. Be prepared to connect.

The arithmetic circuit 44 includes both circuits (programs) with and without a cooler in advance. As a result, when equipped with a cooler, the necessary sensor wiring, cooler equipment, another cooling fan 26, and motor controller 60
Is added.

Further, the control device 44 is provided with a terminal 62, which is connected so that an ON signal is inputted through this terminal when the cooler is attached. As a result, the arithmetic circuit 44 determines whether or not the cooler is provided.

The arithmetic circuit 44 calculates the air volume by the two cooling fans 22 and 26 required to keep the cooler high pressure at the set value (air volume calculation value 1).

In addition, the air volume by the two cooling fans 22 and 26 required to keep the engine cooling water temperature in the case with the cooler at the set temperature is calculated (air volume calculation value 2).

Further, in order to maintain the engine cooling water temperature without the cooler at the set temperature, the air volume required by one cooling fan 22 is calculated (air volume calculation 2 ').

Here, the characteristic feature of the present invention is that the air volume for maintaining the engine cooling water temperature at the set temperature is compared with the air volume required for maintaining the cooler condenser pressure at the set pressure, and either of the required air volumes is greater. That is, the rotation control of the first and second cooling fans is performed so as to obtain one of the air volumes.

That is, in this embodiment, the air volume by the cooling fans 22 and 26 required to maintain the cooler condenser pressure at the set pressure is the cooler high pressure detected by the high pressure sensor 52 and the cooler low pressure detected by the low pressure sensor 54. It is calculated from the pressure, the refrigerant temperature in the vicinity of the evaporator outlet detected by the refrigerant temperature sensor 56, the outside air temperature detected by the outside air temperature sensor 46, and the vehicle speed detected by the vehicle speed sensor 48.

In addition, the air volume by the cooling fans 22 and 26 required to keep the engine cooling water temperature at the set temperature is adjusted by the fuel injection amount control device 4
Data from 3, the outside air temperature detected by the outside air temperature sensor 46, the engine cooling water temperature detected by the water temperature sensor 50,
It is calculated from the vehicle speed detected by the vehicle speed sensor 48.

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. Therefore, it is possible to reduce the energy required for cooling and effectively suppress the generation of noise.

Hereinafter, regarding these air volume calculations, the air volume calculations 1, 2 ′, 2
Will be described in detail in this order.

Calculation of First Air Volume In the embodiment, the condenser 28 and the radiator 30 are cooled not only by the cooling air by the cooling fans 22 and 26 but also by the vehicle speed air 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 to control the high pressure of the capacitor 28 to the desired set value Ps is required for the capacitor cooling. Calculate 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 wa} b + K 3 (tc-ts)
+ C (1) where Qe is the amount of heat absorbed by the evaporator, Qp is the calorie conversion value of the compressor compression work, and ts is the refrigerant temperature with respect to the high pressure Ps of the condenser, which is the refrigerant pressure and evaporation (condensation). It can be uniquely determined from the relationship of temperature. Also, to
Is the outside air temperature, w is the vehicle speed, tc is the refrigerant temperature (condensation temperature) in the condenser, and K ₁ , K ₂ , K ₃ and a, b, c are constants.

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 formula from the Pi 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, to calculate this Qe, the variables G, i _I , i _IV
Need to ask for each.

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

However, s: passage area of expansion valve ζ: passage coefficient of expansion valve γ: specific weight of refrigerant at evaporator outlet g; gravitational acceleration Since s, ζ and γ change with Pe and t _I respectively, the above (2) The formula is transformed into the following formula.

put it here, Is the relationship between Pe and t _I In other words, using F ₁ (x, y), the equation (3 ′) is converted as follows.

Therefore, G can be obtained by measuring and obtaining F ₁ (Pe, t _I ) in advance. (Note that Pe, t _I , Pc
Is detected by the sensor. ) (A-2) Variable i _IV Next, the operation for obtaining the enthalpy i _IV of the refrigerant at the inlet of the evaporator will be described based on the Pi diagrams shown in FIGS. 2 and 3.

First, the value i of the point enthalpy on the saturated liquid line AB of the refrigerant is obtained. Here, an arbitrary point x (pressure p) on the saturated liquid line
The enthalpy i of 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.
The value obtained by subtracting the difference Δi _III in enthalpy, that is, i _IV = i _III ′ −Δi _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 therefore i _IV = i _III = i _III ′
−CL · Δt _III .

On the other hand, i _III ′ is the high pressure Pc detected by the high pressure sensor 64.
Is calculated based on the equation (4) as follows.

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,
As a result, i _IV is obtained using the above equation (5).

(A-3) Variable i _I Next, find the enthalpy i _I at the exit of the evaporator 12. _{First, = F 2 (Pe) ··} 'i IV by the equation (4)' When low pressure low pressure sensor 66 has detected the 'a Enpitaru of i _IV' point IV of saturated liquid line when Pe and i _IV・ ・ It becomes (6).

Next, the imperial i _I ′ at the point I ′ on the saturated vapor line is calculated as 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.

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

On the other hand, the empital i I at the point _I is the empirical i _I ′ at the point _I ′ plus the enthalpy difference Δi _I from _I to _I ′, i _I = i _I ′ + Δi _I where Δi _I is the I point Let t _I be the temperature of point _I and t _I ′ be the temperature at point I ′.

Δi _I = Cp Δt _I However, Δt _I = t _I −t _I ′, Cp represents constant pressure specific heat.

Also, t _I ′ is a function of the pressure and evaporation temperature of the following refrigerant F ₄ (x)
Required from. t = F ₄ (P) (9) Here, if the low pressure Pe detected by the low pressure sensor 66 is substituted into the equation (9), the evaporation temperature at that time, t _I ′, is given by the following equation. Desired.

tI ′ = F ₄ (Pe) (10) On the other hand, the temperature t I at point _I is detected by the refrigerant temperature sensor 68, so Δt _I is calculated by Δt _I = t _I −F ₄ (Pe) As a result, Δi _I becomes Δi _I = Cp {t _I −F ₄ (Pe)} ... (11).

Therefore, the enthalpy i _I = I _IV ′ + r + Δi _I ′ at point _I can be obtained from Eqs. (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 Eqs. (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 (P
e)} − {F ₂ (Pc) −CL · Δi _III }] ... (13).

(B) Converted calorific value Qp of compressor compression work First, the compression work L of the compressor 14 is given by the following equation.

(N-1) / n L = G (n / n-1) P 1 V I [(P 2 / P 1) -1] ···· (1
4) where G is the refrigerant flow rate, n is the polytropic index,
P ₁ is the refrigerant pressure at the inlet of the compressor 32, P ₂ is the refrigerant pressure at the outlet of the compressor 32, V _I is the specific volume of the refrigerant at the inlet of the compressor 32, G is obtained from equation (3), and n is approximately the specific heat. The ratio κ may be substituted, P ₁ ≈Pe, P ₂ ≈Pc. The V _I is represented by the relational expression P ₁ V _I = RT ₁ , where T ₁ = 237 + t _I , R is the gas constant 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 equations (3) and (15) into equation (14), P ₁ = P
Substituting e, 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 work equivalent of heat) Therefore, from 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), (17)}.

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 required to maintain the high pressure at a constant value Ps.
W ₁ (first air volume) is given by the following equation.

W ₁ = K ₁ [{(Qe + Qp) / (F ₄ (Ps) −to)} − K ₂ Wa} b
＋ K ₃ {F ₄ (Pc) −F ₄ (Ps)} + C ・ ・ ・ ・ (18) where And F ₁ (x, y), F ₂ (x), F ₃ (x) and F ₄ (x) are predetermined functions.

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, W is the vehicle speed detected by the vehicle speed sensor 72, Pe is the low pressure pressure detected by the low pressure sensor 66, t _I is the refrigerant temperature at the outlet of the evaporator 36 detected by the refrigerant temperature sensor 68, 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, a is around 0.5, b is a value around 2.

Second 'Calculation of Air Volume This is the air volume by one cooling fan 22 required to keep the engine cooling water temperature at the set temperature ts when the cooler is not provided.

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 heat quantity supplied to the cooling water can be obtained from the fuel injection quantity. On the other hand, the amount of heat radiated from the cooling water is mainly affected by the outside air temperature, the vehicle speed (wind speed due to running wind), and the rotation speed of the cooling fan (wind speed due to the cooling fan), and the cooling water temperature is maintained at the set temperature tse. Electric cooling fan 2 required for
The air volume by 2 (air volume calculation 2 ') is calculated by the following equation.

W ₂ ′ = K ₁₁ ′. _{{K 12 hm / (tse-} to) -K 13 'wa} b +
K ₁₄ ′ (t _W −tse) + Ce ′ (101) However, W ₂ ′: Air volume (electric volume calculation 2 by the electric cooling fan required to set the engine cooling water temperature without the cooler to the set temperature tse ′) _M : fuel injection amount per unit time value w: vehicle speed detected by the vehicle speed sensor t _W : engine cooling water temperature detected by the water temperature sensor to: outside air temperature detected by the outside air temperature sensor tse: cooling water to be kept constant Target value of temperature h: Calorific value of fuel per unit weight (about 10,200 kcal / kg) K ₁₁ ′, K ₁₂ ′, K ₁₃ ′, K ₁₄ ′, Co ′, a, b are constants. However, a is
The values around 0.5 and b are around 2.

Second air volume calculation This is the air volume by the two cooling fans 22 and 26 required to keep the engine cooling water temperature at the set temperature tse when the cooler is attached.

Basically, the formula (101) is used, but if a cooler is attached, a condenser will be installed first, which will increase the ventilation resistance and reduce the air volume due to the vehicle speed. This can be done by newly changing the multiplier K13 'in the expression (101) to K13.

Next, when the cooler operates, the air that has passed through the condenser 28 is heated by the condenser 28 and the temperature thereof rises, and passes through the radiator 30, as shown in FIG. Therefore (10
The temperature of the air after passing through the capacitor 28 must be substituted in place of the outside air temperature to in equation (1).

The temperature of the air after passing through the condenser 28 is calculated by the following equation.

ta = Atc + (1-A) × to (102) However, ta: Air temperature after passing through the condenser tc: Refrigerant temperature at the condenser, and the pressure and the evaporation temperature of the refrigerant from the high pressure detected by the high pressure sensor. The relational expression, that is, tc = F ₄ (P) obtained from t = F ₄ (P) in the expression (9)
c) However, Pc: Cooler high pressure detected by the high pressure sensor to: Outside air temperature detected by the outside air temperature sensor A: Constant Also, the equation (102) is tc = t when the cooler is not operating.
Since it is o, substituting it gives ta = to. That is, since the air temperature after passing through the condenser is the outside air temperature when the cooler is not operating, the equation (102) can be used as it is even when the cooler is not operating.

Therefore, the cooling fans 22,26 required to keep the engine cooling water temperature at the set temperature tse when the cooler is installed
For the air flow rate (air flow rate calculation 2), the constant of equation (101) is changed, and ta is substituted for the outside air temperature to. That is, ta
= Atc + (1-A) to = sought by substituting the _{AF 4 (Pc) + (1} -A) to be the next equation.

W ₂ = K ₁₁ [K ₁₂ × h × m / {tse−AF ₄ (Pc) − (1-A) to
−K ₁₃ wa] + K ₁₄ (t _W −tse) + Ce… (103) where W ₂ : is the engine cooling water temperature when equipped with a cooler.
Air volume by cooling fans 22 and 26 required to keep se (air volume calculation 2) K ₁₁ , K ₁₂ , and K ₁₄ are constants K ₁₁ = K ₁₁ ′, K ₁₂ ＝ K ₁₂ ′ K ₁₄ ＝ K ₁₄ ′.

Then the applied voltage V _S of the electric motor necessary for obtaining the air volume W _S is substantially proportional to the air volume W _S.

That is, W _S = K · V _S K is a constant. However, when the cooler is not attached, the air flow resistance of the capacitor 28 decreases, so a slightly smaller applied voltage is required to obtain the same air volume, and in this case W _S = K ′ · It becomes V _S , and K ′ becomes a constant of K ′ <K.

Next, regarding the control method by the arithmetic circuit 44, if the cooler is not attached, the air volume (W ₂ ′ by one cooling fan 22 required to keep the engine cooling water temperature at the set temperature tse based on the equation (101). ) Is calculated (air volume calculation 2 ').

Next, the electric motor 20 of the cooling fan 22 for obtaining the above air volume W ₂ ′
Calculate the voltage to be transferred to.

(Voltage calculation value _{2 ') V 2' = K'W} 2 '... (104) V 2': air volume W ₂ in the case of no cooler '(airflow rate computation value 2') voltage value 2 'subsequent operation for obtaining the The circuit 44 issues a command to the electric motor control device 58, and the electric motor control device 58 applies the voltage of the calculated voltage value 2 ′ (V ₂ ′) to the electric motor 20 of the cooling fan 22.

Next, in the case with a cooler, set the air volume W ₁ (air volume calculation 1) by the two cooling fans 22 and 26 required to keep the cooler high pressure at the set pressure P _S to (19), (20), (18 ) Calculate from the formula.

After that, the air volume W ₂ (air volume calculation 2) by the two cooling fans 22 and 26 required to keep the engine cooling water temperature at the set temperature tse is calculated based on the equation (103).

Next, the arithmetic circuit 44 uses the above-mentioned air volume calculation 1 (W ₁ ) and air volume calculation 2
Compare with (W ₂ ). The larger air volume of W ₁ and W ₂ is obtained, but here, for example, the case where W ₁ is larger will be described.

The air volume of air volume calculation 1 (W ₁ ) is distributed to the two cooling fans 22 and 26. Here, a case where the two cooling fans 22 and 26 are the same will be described. W ₁ / by cooling fans 22,26
Try to get two airflows each. Therefore, the arithmetic circuit 44 is 1
The voltage to be applied to the electric motor to obtain the air volume of W _1/2 with each cooling fan 22 is calculated, but in the end V ₁ = KW ₁
The voltage of V ₁ becomes 1/2 × V ₁ and becomes the same as the voltage, and cooling fan 2
A voltage of 1/2 × V ₁ is applied to each of the electric motors 20 and 24 of 2,26. W ₂
When it is larger than W _1, a voltage of 1/2 × V ₂ of the voltage V ₂ = K · W ₂ is applied to the electric motors 20 and 24.

Next, a control flow chart of the present invention will be described with reference to FIG.

In step 501, the inputs of the outside air temperature sensor 46, the vehicle speed sensor 48, and the water temperature sensor 50 are read. In step 502, the fuel injection amount information is received from the fuel injection amount control device 43. In step 503, it is determined from the information of the terminal 62 of the arithmetic circuit 44 whether or not a cooler is provided. If no cooler, step 521 (1
01) for calculating air flow rate, i.e. flow rate calculation value 2 '(W _2') by the cooling fan 22 required to keep the engine cooling water temperature to the set temperature ts based on the formula. Also, the voltage applied to the electric motor 22 to obtain W ₂ ′, that is, the voltage calculation value 2 ′
Calculate (V ₂ ′).

In step 522, V ₂ ′ is compared with a predetermined value of C ₁ . V ₂ ′
Is greater than or equal to the predetermined value C ₁ , the cooling fan 22 must be rotated to keep the engine cooling water temperature at the set temperature tse, and in step 525, the voltage V ₂ ′ is applied to the electric motor 20.
If V ₂ ′ is less than C _{1 in} step 522, then in step 523
Compare V ₂ ′ with a predetermined value C _{2 that} is less than C ₁ .

When V ₂ ′ is C ₂ or less, set the engine cooling water temperature to the set temperature ts
Since the cooling fan 22 does not need to rotate to keep e, the electric motor 20 is stopped.

'Is larger than C _2, V _2' V ₂ at step 523 C ₁ -C
A value between ₂ and in this case keep the current value. That is, if the cooling fan 22 is currently rotating, it continues to rotate at the same rotation speed. If the cooling fan 22 is currently stopped, the stopped state is maintained. C ₁ -C ₂ is a hysteresis motor 20 is ON with a little change of V ₂ '
Prevent hunting for / OFF.

If a cooler is installed in step 503, proceed to step 504, high pressure sensor 52, low pressure sensor 54, refrigerant temperature sensor.
Read input from 56.

Next, at step 505, the refrigerant flow rate is calculated based on the equation (3).

In step 506, the amount of heat supplied to the evaporator is calculated based on the equation (19).

In step 507, the heat conversion of the compressor compression work is calculated based on the equation (20).

In step 508, the air volume by the cooling fan required to maintain the cooler high pressure at the set pressure P _S , that is, the air volume calculation value 1 (W ₁ ) is calculated based on the equation (18).

If the two cooling fans 22 and 26 have the same specifications, the air volume by the two cooling fans 22 and 26 will be 1 / 2W ₁ each, and the voltage applied to the motors 20 and 24 will also be V ₁ = It becomes ₁ / 2V 1 at a time that bisects the KW ₁ becomes V _1. Therefore, the calculated voltage value (V ₁ ) is calculated from V ₁ = KW ₁ .

Next, at step 509, based on the equation (103), the air volume by the cooling fan required to keep the engine cooling water temperature with the cooler at the set temperature tse, that is, the air volume calculation value 2
Calculate (W ₂ ). Similar to step 508, the voltage calculation value 2 (V ₂ ) such that V ₂ = KW _{2 is} obtained.

Next, in step 510, W ₁ and W ₂ are compared. When W ₁ is W ₂ or more, W ₁ is substituted for W in step 511. If W ₁ is smaller than W ₂ , then W ₂ is substituted for W in step 516. Then, in step 512, W is compared with a predetermined value A ₁ . When W is A ₁ or more, the cooling fan must be rotated to keep the cooler high pressure at the set value P _S or the engine cooling water temperature at the set temperature tse.
Voltage is applied.

If W is smaller than A _{1 in} step 512, the process proceeds to step 513, and W is compared with a predetermined value A ₂ smaller than the predetermined value. When W is equal to or lower than A ₂ , it is not necessary to rotate the cooling fan to keep the cooler high pressure at the set value P _S or the engine cooling water temperature at the set temperature tse, so at least one cooling fan 24 is stopped.

If W is larger than A _{2 in} step 513, the current state is maintained. That is, if the cooling fan 26 is currently rotating, it continues to rotate at the same number of revolutions, and if the cooling fan 26 is currently stopped, the stopped state is maintained.

A _{1 to} A ₂ are hysteresis, and a slight change in W
Prevent 24 from hunting ON / OFF. Next, at step 514, W is compared with a predetermined value B1. When W is B ₁ or more, the cooling fan needs to rotate to keep the cooler high pressure at the set value P _S and the engine cooling water temperature at the set temperature tse, and at least one cooling fan 22 is rotated. Therefore, in step 520, a voltage of 1/2 W is applied to the electric motor 20. If W is smaller than B _{1 in} step 514, step 515
To advances W and comparing the predetermined value B ₁ is smaller than a predetermined value B _2.

If W is B ₂ or less, set the cooler high pressure to the set pressure P _S ,
Alternatively, since it is not necessary to rotate the cooling fan to keep the engine cooling water temperature at the set value tse, the electric motor 20 is stopped in step 518.

If W is larger than B _{2 in} step 515, the current state is maintained. That is, if the cooling fan 22 is currently rotating, the cooling fan 22 continues to rotate at the same rotation speed, and if it is stopped, the stopped state is maintained. B _{1 and} B ₂ are hysteresis and prevent the motor 20 from hunting ON / OFF by a slight change in W.

Then, the reset of step 526 returns to the start of step 500, and this is repeated.

Next, the value of W and the operation of the electric motors 20 and 24 in FIG. 6 will be described.

It is assumed that the value of W gradually increases from a very small value. Initially, both electric motors 20 and 24 are stopped. When W becomes B1, the electric motor 20 starts rotating. The rotation speed at this time is N1, and thereafter, the rotation speed also increases as W increases.
On the other hand, the electric motor 24 is still stopped when W is B1, and starts to rotate when W becomes a larger value and becomes A1. At this time, the rotation speed is N2.

After that, the number of rotations increases as the rotation of W increases. At A _{1 and} above, both motors 20 and 24 are rotating. Next, a case where a large value of W, for example, a value of W from D becomes small will be described.

When W is D, the electric motors 20 and 24 are rotating at the rotation speed N3. As W decreases, the rotation speed also decreases, and when W becomes A ₁ , the rotation speed of both motors 20 and 24 is N ₂ , and when W decreases further, motor 24 remains at the rotation speed of N _2.
20 will reduce the number of rotations.

When W becomes B1, the rotational speed of the electric motor 24 is an electric motor 20 remains N2 is the rotational speed of N _1. When W is further reduced, the electric motor 24 remains at N ₂ and the electric motor 20 remains at N ₁ . When W becomes smaller and W becomes A ₂ , the electric motor 24 stops and the electric motor 20 becomes the rotation speed of N1 and W becomes smaller,
When becomes B ₂ , the electric motor 20 also stops.

In the above description, as an example, two cooling fans 2
The case where the specifications of 2 and 26 are the same has been described, but these may be different, and the specifications of the motors 24 and 20 may be different.

As described above, the present invention maintains the engine cooling water temperature at the set temperature and sets the cooler high pressure to the set pressure even when the condenser and the radiator are arranged in series with respect to the air flow. Since the control is performed with the minimum required air volume that satisfies both of the requirements, the noise level is low and the energy can be effectively used.

Further, by continuously changing the rotation speeds of the two cooling fans, there is no stepwise change in the rotation speed as in the conventional case, and therefore the generation of noise is prevented.

[Brief description of drawings]

FIG. 1 is a configuration explanatory view of the present invention, FIG. 2 and FIG. 3 are pi diagrams of a refrigerant, and FIG. 4 is a diagram showing temperature change of air passing through a condenser with respect to an air flow direction, FIG. Is a diagram showing a control flow chart of the present invention, FIG. 6 is a diagram showing the relationship between the calculated value W and the rotation speed of the cooling fan, and FIGS. 7 and 8 are diagrams showing the arrangement of the condenser, the radiator and the cooling fan. is there. 20 …… First electric motor 22 …… First cooling fan 24 …… Second electric motor 26 …… Second cooling fan 28 …… Condenser 30 …… Radiator 36 …… Evaporator 43 …… Fuel injection amount control device 44 …… Computational circuit 46 …… Outside temperature sensor 48 …… Vehicle speed sensor 50 …… Water temperature sensor 52 …… High pressure sensor 54 …… Low pressure sensor 56 …… Refrigerant temperature sensor

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 performed by each of these cooling fans. A control device for a vehicle cooling fan that cools the radiator and the condenser by controlling a voltage applied to the first electric motor and the second electric motor by arranging a radiator and a condenser for the cooler in series in an air flow path. In the above, including an arithmetic circuit having a built-in cooling control program for both the condenser for the cooler and the radiator, the air volume required to keep the engine cooling water temperature at the set temperature and the air volume required to keep the condenser pressure at the set pressure. And the rotation control of the first and second cooling fans is performed so that the larger one of these required air flows is obtained. The vehicle cooling fan control device being characterized in that the. 2. The device according to claim 1, wherein the device detects a high pressure sensor for detecting a high pressure in the refrigerant circulation path of the cooler, and a low pressure for detecting a low pressure in the refrigerant circulation path of the cooler. Low-pressure pressure sensor, refrigerant temperature sensor that detects the refrigerant temperature near the evaporator outlet in the refrigerant circulation path of the cooler, outside air temperature sensor that detects the outside air temperature of the vehicle, water temperature sensor that detects the engine cooling water temperature, and vehicle speed A vehicle speed sensor that detects The refrigerant temperature near the evaporator outlet detected by the refrigerant temperature sensor, the outside air temperature detected by the outside air temperature sensor, and the vehicle speed detected by the vehicle speed sensor. And et operation, the air volume of the cooling fan required to keep the engine cooling water temperature to the set temperature,
A cooling fan for a vehicle, which is calculated from data from a fuel injection amount control device, outside air temperature detected by an outside air temperature sensor, engine cooling water temperature detected by a water temperature sensor, and vehicle speed detected by a vehicle speed sensor Control device.