JPS61229921A - Cooling fan controller for vehicle - Google Patents

Abstract

PURPOSE:To lower the noise level while to utilize the energy effectively by controlling with the minimum necessary air flow for satisfying both conditions that the engine cooling water temperature is maintained at a setting level and the cooler high pressure is maintained at a setting level even when a condenser and a radiator are arranged in series against the air flow. CONSTITUTION:First fan 22 to be driven through first motor 20 and second fan 26 to be driven through second motor 24 are arranged in parallel. The air flows necessary for maintaining the engine cooling water temperature at a setting level and for maintaining the cooler high pressure at a setting level are operated through an arithmetic circuit 44 and compared. Then the larger one is selected to equalize the sum of the air flows of two cooling fans with said level. Consequently, the noise level is lowered while the energy is utilized effectively.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a control device for a cooling fan for a vehicle, and particularly to a control device for an electric fan that cools a cooler condenser and a radiator.

[Prior Art] Conventionally, a radiator cooling device for automobiles using an electric cooling fan is well known, and this device maintains engine cooling water at an optimum value of around 85 to 95 degrees Celsius. Therefore, when the engine coolant temperature reaches the upper limit temperature of the set value, the electric motor is automatically turned on to start cooling the radiator, and when the engine coolant temperature reaches the lower limit temperature of the set value, the electric motor is automatically turned on. It's off. That is,
Through such on/off control of the electric motor, the engine coolant temperature is controlled within an optimal range, usually in the range of 85 to 93°C.

However, such devices each time the electric motor is turned on,
The problem is that the rotation speed of the cooling fan suddenly rises from 0 and temporarily generates a large noise, and this step-like noise is extremely annoying and uncomfortable for the driver and other passengers of the vehicle. was there.

In particular, in such devices, the electric motor is frequently turned on and off in order to control the temperature of the engine cooling water to an optimal value.
Since the noise is generated each time, an effective countermeasure has been desired.

For this reason, a device according to Japanese Patent Application No. 59-168528 has been proposed. This device has various sensors such as an outside temperature sensor, a vehicle speed sensor, and a water temperature sensor.Based on the output of these sensors, it constantly calculates the voltage applied to the motor in real time to maintain the engine cooling water at the set value. However, this voltage is always applied to the motor that drives the cooling fan.

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

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

In such cases, two types of cooling systems are available: one in which a condenser and a radiator are arranged in parallel with the air flow, as shown in Figure 7, and each cooled by an electric fan, and the other, as shown in Figure 8, in which a condenser and a radiator are arranged in parallel to the air flow. Some are placed in series with the air flow.

The apparatus shown in FIG. 7 is effective when the condenser and the radiator are arranged in parallel with the air flow, and the condenser and the radiator are cooled independently by their 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 10 and a cooler 12 are arranged in series with each other in the flow path of cooling air supplied by these cooling fans. It is formed. And, independent of the electric motor for the radiator,
When the cooler compressor is turned on, the motor of the condenser cooling fan is also turned on, and when the compressor is turned off, this motor is also turned off.

[Problems to be Solved by the Invention] ``However, with the above-mentioned conventional technology, is it possible to cool the radiator? When the I-movement is rotating roughly, the condenser is also being cooled. Therefore, even if the condenser cooling fan is rotated at a lower speed, the cooler high pressure can be kept at the set pressure.

Conversely, when the cooling fan that cools the condenser is rotating, the radiator is also being cooled.

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

Therefore, extra cooling air is blown to the radiator 10 and condenser 12 than they require, and such extra cooling air causes wasted energy and generation of noise. There were drawbacks.

The present invention has been devised in view of these conventional problems, and its purpose is to efficiently cool the radiator and cooler condenser with the minimum necessary amount of cooling air, and to reduce the noise generated. An object of the present invention is to provide a control device for a cooling fan for a vehicle that can effectively suppress the above.

[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. A radiator and a cooler condenser are arranged in series with each other in the flow path of cooling air supplied by each of these cooling fans.

Then, the air pressure required to maintain the engine coolant temperature at the set temperature and the air flow required to maintain the cooler high pressure at the set pressure are calculated, and the two are compared.

Then, the larger air volume is selected between the two, and the rotation of the two cooling fans is made such that the sum of the airflow from both fans becomes the air volume.

As a result, even when the condenser and radiator are placed in series with the air flow, the engine cooling water temperature can be maintained at the set temperature, and the cooler high pressure can also be maintained at the set pressure, making it possible to maintain the required minimum Effective use of energy can be achieved with a limited amount of airflow.

Further, the rotation speeds of the two cooling fans can be continuously and effectively controlled, and generation of noise due to sudden changes in the rotation speed can be prevented.

[Example] Next, preferred embodiments of the present invention will be described based on the drawings.

FIG. 1 is an explanatory diagram of the configuration 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 rotating shaft of a first electric motor 20 and a second cooling fan 26 directly connected to the rotating shaft of a second electric motor 24 are arranged in parallel with each other. A condenser 28 and a radiator 30 are arranged in series with each other in a flow path of cooling air blown from each cooling fan 22,26.

The condenser 22 and the radiator 30 are cooled by blowing cooling air to the condenser 28 and the radiator 30.

In an embodiment, the cooler capacitor 28 includes:
Compressor 32. Expansion valve 34. Evaporator 36. Together with the temperature sensing tube 38, it forms a refrigeration cycle of the cooler.

The refrigerant circulating in this refrigeration cycle is compressed in the compressor 14 to become a high-temperature refrigerant gas, cooled in the condenser 28 to become a liquid, expanded adiabatically in the expansion valve 34 by the throttling action of the valve, and is atomized. Heat is removed from the air in the evaporator 36 and the air is vaporized, becoming completely gas just before the exit of the evaporator 36 and absorbed into the compressor 32 again.

Here, if the refrigerant passing through the evaporator 36 completely becomes gas on the way to the vicinity of its outlet,
This vaporized refrigerant is then heated until it reaches the outlet, and the temperature at the evaporator outlet increases, which is undesirable.

To prevent this kind of situation from occurring, evaporator 3
Feel the temperature near the exit of 6! i! If the detected temperature rises in the cylinder 38, the flow path of the expansion valve 34 is expanded to increase the amount of refrigerant supplied, and if a large amount of refrigerant still remains in the form of droplets at the outlet of the evaporator 36, Then, the sensor m138 senses the low temperature of the refrigerant and narrows the flow path of the expansion valve 34 to reduce the amount of refrigerant supplied.

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

By the way, in the refrigeration cycle of this cooler, the heat radiation amount of the condenser 28 is equal to the heat absorption IQe of the evaporator 36.
and the calorific value Qp of the compression work of the compressor 32, which is the sum of Qe+Qp. Therefore, the sum Qe+Qp of the heat absorption amount Qe of the evaporator 36 and the heat conversion IQp 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. In addition, if the amount of cooling air to the condenser 28 is increased, the amount of heat dissipated will increase, and the high pressure inside the refrigeration cycle will be lowered.On the other hand, if the amount of cooling air blown is decreased, the high pressure inside the refrigeration cycle will increase. Become.

Therefore, by controlling the cooling air, the condenser 2
8 can be controlled to a desired set point ps.

Further, the radiator 30 cools engine cooling water, and the engine cooling water is supplied to 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 of the cooling fans 22 and 2
Both a condenser 28 and a radiator 30 are located in the cooling air flow path by 6.

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 26.
It is also cooled by a cooling fan 22.

Further, the fuel injection information is the fuel injection information that controls the fuel injection amount of the engine 40. l) l I It is connected so that it is input from the II control device 43 to the arithmetic circuit 44.

Furthermore, at appropriate locations on the vehicle are 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 coolant temperature, and a high pressure sensor 52 for detecting the high pressure of the cooler. A low pressure sensor that detects the low pressure and a refrigerant temperature sensor 56 that detects the refrigerant temperature near the evaporator outlet are arranged.

A motor control device 58.60 is provided to control the cooling fan 22.26. This controls the voltage applied to the motor 20.24 of the cooling fan 22.26 based on commands from the arithmetic circuit 44. The motor control device F58.60 may be something like a transistor,
In this case, pulse 1 duty control is performed, and by changing the duty ratio, the voltage applied to the electric motor 20.24 can be controlled.

Arithmetic equipment again! ! 44 may be something like a microcomputer, and performs control as described later. Furthermore, when looking at vehicle coolers, they are generally installed after the vehicle is manufactured or on the market.

If a cooler is not installed, one cooling fan 22 is used for cooling. Also, when the cooler is installed, a new sensor is required, namely the high pressure sensor 52. Low pressure sensor 54. A terminal for the refrigerant temperature sensor 56 is provided in the arithmetic circuit 44 in advance so that it can be connected when the cooler is installed.

The arithmetic circuit 44 includes in advance both circuits (programs) without a cooler and with a cooler. As a result, when a cooler is installed, the necessary sensor connections, cooler equipment, another cooling fan 26, and motor control device 60 are added.

The control device 44 is also provided with a terminal 62, which is connected to receive an ON signal when the cooler is installed. Accordingly, the arithmetic circuit 44 determines whether the air conditioner is equipped with a cooler or not.

The calculation circuit 44 calculates the air volume of the two cooling fans 22 and 26 necessary to maintain the cooler high pressure at the set value (air volume calculation value 1).

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

Furthermore, in order to maintain the engine cooling water temperature at the set temperature when there is no cooler, one cooling fan 22 is required.
Calculate the amount i (7111 calculation 2-).

Here, the characteristic feature of the present invention is to compare the ventilation required to maintain the engine cooling water temperature at the set temperature with the air volume required to maintain the cooler condenser pressure at the set pressure, and to determine which of these required air volumes. The purpose is to control the rotation of the first and second cooling fans so that JiRffi is larger.

That is, in this embodiment, the cooling fans 22 and 26 necessary to maintain the cooler condenser pressure at the set pressure are
The air flow rate is determined by the air flow rate detected by the high pressure sensor 52, the low pressure sensor 54, the low pressure sensor 54, the refrigerant temperature near the evaporator outlet, and the outside air temperature sensor 46. It is calculated based on the outside temperature and the vehicle speed detected by the vehicle speed sensor 48.

In addition, the air volume by the cooling fans 22 and 26 necessary to maintain the engine coolant temperature at the set temperature is calculated based on the data from the fuel injection amount control device 43, the outside air temperature detected by the outside air temperature sensor 46, and the water temperature sensor 50. It is calculated from the detected engine coolant temperature and the vehicle speed detected by the vehicle speed sensor 48.

Therefore, according to the present invention, the condenser 28 and the radiator 30 can be cooled with a smaller amount of cooling air than in the conventional technology.

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

Below, regarding these air volume calculations, the above ff1fl enson 1
．． 2' and 2 will be explained in detail in this order.

In the first air volume calculation example, the capacitor 28 and the radiator 30 are
The vehicle is cooled not only by the cooling air generated by each of the cooling fans 22 and 26, but also by the wind generated by the speed of the vehicle while the vehicle is running. Therefore, in this embodiment, considering the cooling of the condenser 28 by the vehicle speed wind, the value obtained by subtracting the vehicle speed wind from the cooling air volume required to control the high pressure of the condenser 28 to the desired set value ps is calculated as the value required for condenser cooling. Calculate as I W + .

Here, the required air volume W1 for cooling the capacitor is given by the following equation.

W+ −to+ ((Qe +QD /ls −to)
-K2W) + Ks (tc-ts) 10... (1) However, Qe is the amount of heat absorbed in the evaporator, Qp is the calorific value of the compressor compression work, and ts is the refrigerant temperature with respect to the high pressure ps in the condenser. , which is uniquely determined from the relationship between refrigerant pressure and evaporation (condensation) temperature.

Also, to is the outside temperature, W is the vehicle speed, tc is the refrigerant temperature in the condenser (condensation temperature), Kl + K2 v K3
, ae be C each represent a constant.

The capacitor shown in this first equation must be cooled! In order to calculate ff11w+, it is first necessary to obtain its variables Qe and Qp.

(a) Heat absorption amount Qe Here, the heat absorption IQe to the evaporator, which is one of the variables, is determined by the following equation using the P-1 diagram (Mollier diagram) of the refrigerant shown in FIG.

Q e-G (i 1 - i 1y ) where G is the refrigerant flow rate, 11 is the enthalpy of the refrigerant at the outlet of the evaporator, and 'IV is the enthalpy of the refrigerant at the inlet of the evaporator.

Therefore, in order to calculate this Qe, the variables Q, i
, i, respectively.

I■ (a-1) Variable G First, in this embodiment, the refrigerant flow ff1G can be determined based on the detection signal of the flow meter 62 provided in the refrigerant circulation path of the cooler.

In addition to this, the refrigerant 111G can also be determined in the following manner.

That is, the high pressure sensor 64 installed in the refrigerant circulation path of the cooler. Using the high pressure PC1 and low pressure Pe of the refrigerant detected by the low pressure sensor 66 and the refrigerant temperature sensor 68 provided near the evaporator outlet, and the temperature t near the evaporator outlet, the refrigerant flow rate is expressed by the following equation.

G-ζ・52g7 (Pc-Pe) ・・・(2
) However, S: Expansion valve passage area ζ: Expansion valve passage flow coefficient γ: Ratio of refrigerant at the evaporator outlet fiffiQ: 1 force acceleration The above S, ζ, and γ each change by pe, so the above (2 ) is transformed into the following equation.

G-ζ・Sshiwangqjiangi...(3') Here, ζ・8 is a function of pe and tI, so if we set ζ-5i-Fl (Pe, is calculated), Fl ( Equation (3') is converted as follows using X, V).

G-6 (pe, work) q7 possible---(3) Therefore,
G can be determined by measuring and determining Fl (pe, ) in advance.

(Note that Pe, t, and Pc are detected by sensors.) (a-2) Variable fly Next, based on P-illil shown in FIGS. 2 and 3, the refrigerant ental' at the inlet of the evaporator is I
The calculation to obtain V will be explained.

First, the enthalpy value i of a point on the saturated liquid line AS of the refrigerant is determined. Here, any point X on the saturated liquid line (pressure p
) is expressed by the following equation using a function.

1=F2(P)...(4) By the way,
The ental billy near the evaporator inlet is ■′
The value obtained by subtracting the enthalpy difference Δ1■ between ■′ and ■ from the enthalpy at the position, ie, 1=i−−Δfz ■■.

Here, if the temperature difference between point ■' and point ■ is Δtm and the specific heat of the refrigerant liquid is C[, then ΔIm-CL ・Δtm, and therefore i■-iz#:
・-CL ・Δtm ■.

On the other hand, i is calculated as follows based on equation (4) using the high pressure pc detected by the high pressure sensor 64.

+ m −= F 2 (P C) Therefore, the enthalpy i of the refrigerant to be determined is expressed by the following formula: % Here, Δt is generally 5° C. in advance and may be taken as a constant value. Therefore, OL·Δt can be regarded as a constant, and as a result, i■ can be obtained using the above-mentioned equation (5).

(a-3) Variable iI Next, find the enthalpy difference at the exit of the evaporator 12. First, the low pressure detected by the low pressure sensor 66 is Pe
If the ambient of point ■' on the saturated liquid line is i, then i■- is given by equation (4) as ■- 1=F2 (Pe) ・ ・ ・ ・ (6)
■−.

Next, finding the enthalpy of the dot ′ on the saturated steam line, i　I--1■-”r　　　　　

Here, r is the latent heat of vaporization, and using pressure P, r-Fi(P
)...(7) Now, the pressure at I' is the low pressure pe detected by the low-pressure pressure sensor 66, so the latent heat of vaporization at this time is r-F3 (Pe)...
8).

On the other hand, the empirical fl of one point is the empirical i of point I'
− plus the enthalpy difference Δ11 between I~k′, iI−17−+ΔfI, where Δi′ is the temperature at one point tI and the temperature at point T′
−, it is expressed by the following formula.

Δ1−cpΔtI ■ However, Δt I= j I −tI −1 cp represents specific heat at constant pressure.

Also, tI- is a function F4 of the refrigerant pressure and evaporation temperature as shown below.
It is found from (X).

j=F+(P) (9) Here, by substituting the low pressure pe detected by the low pressure sensor 66 into equation (9), the evaporation temperature at that time, tI-, can be found using the following equation.・I can do it.

'jI'-Fl (Pe)...e, 6 @
(10) On the other hand, the temperature t at one point is detected by the refrigerant temperature sensor 68, and therefore Δ is At −t −Fl (Pe)? The result I is calculated as Δi = Cp (tI − Fl (pe))・
...(11).

Therefore, the enthalpy 'I"IIV-÷r+Δi of one point can be found from equations (6), (8), and (11), i ■-F2 (Pe)"Fl (Pe)"Cp (
t −Fl (Pe))...(12)■.

Therefore, the amount of heat absorbed by the evaporator 12 Qe is Qe −'
G (i 1-i ■) - to (3), (5), (12)
Substituting the formula, we find Qe−P+ (Pe, tI) [F
2 (PG)”Fl (Pe)”CD (tI −
Fl (Pa)) - (F2 (PC) - OL・Δ
jIII)]...(13)

(b) Converted hot eel value Qp of compressor compression work First, the compression work of compressor #t14 is given by the following equation.

(n-1)/n L= G(n/n-1) P+ V [(F2/
PI)-1] ...(14)
Here, G is the refrigerant flow 1. n is the polytropic index,
Pl is the refrigerant pressure at the inlet of the compressor 32, and F2 is the refrigerant pressure at the outlet of the compressor 32.

v is the refrigerant specific volume at the inlet of the compressor 32, and G
is determined from equation (3), n may be approximately substituted for the specific heat ratio, and P+ = pe, F2 #PCt'. Note that the above ■■ is expressed by the relational expression P+V1=RT+, where T+ -237+t R is the gas constant of the refrigerant. Therefore, v+ is determined by the following formula.

V+ −(RT t /P I)−(Rx (237+
(15) Therefore, by substituting equations (3) and (15) into equation (14), P
By substituting + -Pa and F2-Pc, L is expressed by the following formula.

L= P+ (pe, t I) J” (lower c-Pe)
, (n/n-1)・Pe・(R(engineering 237+)
/Pe) [Pc/Pe) -11---
-(16) Next, the converted heat amount of compressor compression work Qp
seek. Here, the conversion formula for L into 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), QD is given by the following equation.

op-AF+ (Pe, i engineering) C cat-(n
/n-1) ・pe ・(R(237+t I ) /Pe ) [(Pc/Pe
) -1] ... (17) In the above, when it is necessary to cool the capacitor in order to make the high pressure of the capacitor 16 a constant value ps, that is, the first Ml ff
i W + can be calculated ((1), (9).

(13), (17)).

However, ts is calculated from ts-Fl(PS) using equation (9). tc is also calculated using equation (9) as tc=Fl (P
Determine from C).

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

W+ -K+ [((Qe+Qp)/ (Fl (P
S ) -to))- to 2 Wa) b + to 3 (F
l (PC)-P+ (Ps)) ◆C...(18) Here, Qe=F+ (Pe, tI) Ci four lower i-[F2
(Pe)”Fl (Pe)”Cp(tI −Fl
(Pe))-(F2 (PC)-ct・Δtm)
] ......(19) Qp-A e F+ (P e, j engineering) to Pe
)・((n-1)/n)・P e・(R(23
7+tI)/Pe)−[(Pc/Pe)(”10)
-Month ・ ・ ・ ・ (20) and F+ (X, V), F2 (X), F3
(X)F4 (X) is a predetermined function.

Further, PS is a value set as the high pressure of the capacitor 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 pe is 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, C[ is the specific heat of the refrigerant liquid, and Δtm is a constant value (
constant) s K+ * K2, 3- a-b, cG;
is a constant, a has a value of around 0.5, and b has a value of around 2.

2' This is one cooling fan 22 necessary to keep the engine coolant temperature at the set temperature ts when the cooler is not installed.
The air volume is determined by

The engine coolant temperature is theoretically determined by the balance between the amount of heat supplied to the coolant and the amount of heat radiated from the coolant. The amount of heat supplied to the cooling water can be determined from the amount of fuel injection. On the other hand, the amount of heat radiated from the cooling water is mainly affected by the outside air temperature, vehicle speed (wind speed due to driving wind), and cooling fan rotation speed (wind speed due to the cooling fan), and maintains the cooling water temperature at the set WA degree tse. The air volume required by the electric cooling fan 22 (air volume calculation 2') is calculated by the following equation.

W2--to ++ -(KEI hm/ (tse-to
)-Kn-Wa)b +KI4- (tw -tse) +Ce -...(
101) However, W2': The wind generated by the electric cooling fan that is necessary to bring the engine cooling water temperature to the set temperature tse when the cooler is not installed! (Air volume calculation 2') m: Fuel injection amount per unit time value W: Vehicle speed tW detected by the vehicle speed sensor; Engine cooling water temperature tO detected by the water temperature sensor: Outside air temperature tse detected by the outside temperature sensor (kept constant) Target value h of cooling water temperature: Calorific value of fuel per unit weight (approximately 10,200 kcal/klJ) Kn −* KH2−, Ni+a −, Kss−, Go−
, a.

b is a constant. However, a has a value of around 0.5, and b has a value of around 2.

Anal Yunoso 11 times! These are the two cooling fans 22 necessary to keep the engine coolant temperature at the set temperature tse when a cooler is installed.
．． This is the air volume based on 26.

Basically, formula (101) is used, but first, when a cooler is installed, a condenser is attached, which increases ventilation resistance and slightly reduces the air volume due to the vehicle speed, so this is corrected. This is 1 for the multiplier in equation (101).
It is sufficient to newly change 3' to K13.

Next, when the cooler is activated, the air that has passed through the condenser 28 is heated by the condenser 28 as shown in FIG. Therefore, instead of the outside air temperature 10 in equation (101), the capacitor 28
The temperature of the air after passing through must be substituted.

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

ta −Atc + (1−A)xtO・ (102) However, ta: Air temperature after passing through the condenser tC: Refrigerant temperature in the condenser, calculated from the high pressure detected by the high pressure sensor and the evaporation temperature of the refrigerant. tc obtained from the relational expression, 1-F4 (P) in equation (9) = F+ (PC) 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, equation (102) is t when the cooler is not operating.
Since it is c-to, substituting this gives ta-1o. That is, equation (102) can be used as is even when the cooler is not operating, since the air temperature after passing through the condenser is the outside temperature when the cooler is not operating.

Therefore, the cooling fan 2 required to maintain the engine cooling water temperature at the set temperature tse when a cooler is installed
For the air volume according to 2.26 (air volume calculation 2), change the constant in equation (101) and substitute ta in place of the outside temperature to. That is, ta −Atc +(1−A)to −AF◆
(Pc) + (1-A) t.

It is obtained by substituting , resulting in the following formula.

Wl-Ku [KI2xhxm/ (ts13 A
F4(Pc) (IA)to-Kaw ]+
Kg (tw - tse) +Ce (103) where Wl: 22.26L of cooling fan required to maintain the engine cooling water temperature at the set temperature tse when equipped with a cooler
J: 6fflit (filal I calculation 2) Kne KH
2, KH4 is a constant where Kn = Ku', KH2''KI2' +4 = K14-.

Next, the applied voltage ys of the electric motor required to obtain ff1ffiWS is approximately proportional to the wind IWS.

In other words, WS-K・VS K is a constant. However, if the cooler is not connected, the ventilation resistance of the capacitor 28 decreases, so a slightly smaller applied voltage is required to obtain the same HA value, so in this case, WS − becomes ′・Vs. , K'<K, then it becomes a constant of '.

Next, if the control method is based on the arithmetic circuit 44 but the cooler is not installed, l1ii (Wl') by one cooling fan 22 necessary to maintain the engine coolant temperature at the set temperature tse based on equation (101). Calculate (Air volume calculation 2
')do.

Next, the voltage to be transferred to the electric motor 20 of the cooling fan 22 in order to obtain the air volume W2' is calculated.

(Voltage calculation value 2-) V2 -- to -Wl'... (104)■2':
ffl amount W2-(HA amount calculation value 2
') to obtain the voltage value 2- After that, the performance circuit 44 issues a command to the motor control unit 58, and the motor control device 58 applies a voltage of the voltage calculation value 2' (V2-) to the motor 20 of the cooling fan 22. do.

Next, in the case of a cooler, two cooling fans 22, 26 are required to maintain the cooler high pressure at the set pressure Ps.
The air volume W+ (air volume calculation 1) is expressed as (19), (20),
Calculate from equation (18).

After that, the air volume W2 (
Wind II calculation 2) is calculated based on equation (103).

Next, the calculation circuit 44 compares the air volume calculation 1 (W+) and the air volume calculation 2 (Wl). , W+ and Wl, whichever is the larger air volume.
The case where + is larger will be explained.

The ffi amount of JiIm calculation 1 (W+) is distributed to the two cooling fans 22 and 26. Here, a case where the 2WA cooling fans 22 and 26 are the same will be explained. The cooling fans 22 and 26 are configured to obtain an air volume of W+/2. Therefore, the calculation circuit 44 calculates the voltage that should be applied to the motor in order to obtain an air volume of VV+/2 with one cooling fan 22, but in the end, HVI=KW1
The voltage V+ is the same as the voltage of 17) 1/2XV+, and each electric motor 20.2 of the cooling fans 22 and 26
4, a voltage of 1/2×V I is applied. Wl
When is larger than Wl, V2=K・Wl, 1/ of the voltage.
A voltage of 2XV2 is applied to electric ta20.24.

Next, a control flowchart of the present invention will be explained based on FIG.

In step 501, the outside temperature sensor 46. Vehicle speed sensor 48.
Read the input of the water temperature sensor 50. In step 502, fuel injection amount information is received from the fuel injection amount control device 43. In step 503, it is determined based on the information at the terminal 62 of the arithmetic circuit 44 whether the air conditioner is equipped with a cooler or not. If there is no cooler, in step 521, the air volume required by the cooling fan 22 to maintain the engine cooling water temperature at the set temperature ts, that is, the air volume calculation value 2'(W2') is calculated based on equation (101). Further, the voltage applied to the motor 22 to obtain W2', that is, the voltage calculation value 2' (V2-) is calculated.

In step 522, Vt' is compared with a predetermined value CI. When V2- is equal to or higher than the predetermined value 01, it is necessary to rotate the cooling fan 22 in order to maintain the engine coolant temperature at the set temperature tse, and in step 525, the motor 20 is
- Apply voltage. If V2' is smaller than CI in step 522, V2- is compared with a predetermined value C2 smaller than C1 in step 523.

When V2' is below C2, the electric motor 20 is stopped because rotation of the cooling fan 22 is not required to maintain the engine cooling water temperature at the set temperature tse.

If V2- is greater than C2 in step 523, ■2
' is a value between C1 and C2, and in this case, the current value is maintained as it is. That is, if the cooling fan 22 is currently rotating, it continues to rotate at the same number of rotations. If the cooling fan 22 is currently stopped, it remains stopped. CI to C2 are hysteresis, and a slight change in 2' prevents the motor 20 from hunting at 0N10FF.

If the cooler is included in step 503, step 50
Proceed to 4, high pressure pressure sensor 52. Low pressure sensor 54. The input from the refrigerant temperature sensor 56 is read.

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

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

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

In step 508, based on equation (18), J
lll, that is, the air volume calculation value 1 (Wl) is calculated.

Here, if the two cooling fans 22 and 26 are of the same specification, the air volume by the two cooling fans 22 and 26 will be 1/2 W + each, and the voltage applied to the motor 20 and 24 will also be Vl - KW voltage. The result is 1/2 V+, which is obtained by dividing Vl into two. Therefore, from Vl −KW+, the calculated voltage value (
vl ).

Next, in step 509, based on equation (103), the air required by the cooling fan to maintain the engine cooling water temperature at the set temperature tse when equipped with a cooler is -1, that is, ff1l.
Compute the computed value 2 (Wl). Similarly to step 50B, a voltage calculation value 2 (V2) of V2-KW2 is obtained.

Next, in step 510, Wl is compared with Wl.

If Wl is greater than or equal to W2, Wl is substituted for W in step 511. If Wl is less than Wl, Wl is assigned to W in step 516. Thereafter, in step 512, W is compared with a predetermined value A1. , W is greater than or equal to A1, it is necessary to rotate the cooling fan in order to maintain the cooler high pressure at the set value ps or the engine coolant temperature at the set temperature tse, and in step 519, the motor 24 is powered by 1/2W.
Apply a voltage of

If W is smaller than A+ in step 512, the process proceeds to step 513, where W is compared with a predetermined value A2 smaller than the predetermined value. When W is less than or equal to A2, at least one cooling fan 24 is stopped because rotation of the cooling fan is not required to maintain the cooler high pressure at the set value Ps or the engine coolant temperature at the set temperature tse.

If W is greater than A2 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 rotation speed, and if the cooling fan 26 is currently stopped, it remains stopped.

81 to A2 are hysteresis, and a small change in W causes i
! To prevent the motive 24 from hunting 0N10FF. Next, in step 514, W is compared with a predetermined value B1. If W is 81 or higher, set the cooler high pressure to 1I
At Ps, rotation of the cooling fan is necessary to maintain the engine coolant temperature at the set temperature tse, and at least one cooling fan 22 is rotated. Therefore, step 520
A voltage of 1/2 W is applied to the electric motor 20. Step 5
If W is smaller than 81 in step 14, the process proceeds to step 515, where W is compared with a predetermined value B2 smaller than the predetermined value B+.

If W is 82 or less, set the cooler high pressure to the set pressure ps
or because the rotation of the cooling fan is not required to maintain the engine coolant temperature at the set value tse, step 5
At step 18, the electric motor 20 is stopped.

If W is greater than 82 in step 515, the current state is maintained as is. That is, if the cooling fan 22 is currently rotating, it will continue to rotate at the same rotation speed, and if it is stopped, it will remain stopped. aB+~82 is hysteresis, and a small change in W will cause the motor 20 to 0
Prevent N-OFF hunting.

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

Next, the value of W and the operation of the electric motor 20.24 in FIG. 6 will be explained.

Assume that the value of W gradually increases from a very small value. I! Both the first motors 1120 and 24 are in a stopped state. When W reaches 81, the electric motor 20 starts rotating. The rotational speed at this time is N1, and thereafter, as W increases, the rotational speed also increases. On the other hand, the electric motor 24 is still stopped when W is 81, and starts rotating when W increases to a larger value and reaches A1, and at this time the number of revolutions is N2.

Thereafter, as the rotation of W increases, the number of rotations also increases.

Above A1, both electric motors 20,24 are rotating.

Next, a case will be described in which the value of W becomes small from a large value of W, for example, D.

When W is D, the electric motors 20 and 24 are both rotating at the rotation speed N3. As W becomes smaller, the rotation speed also decreases and W becomes A
When W becomes 1, the rotational speed of both the electric motors 1120 and 24 is N2, and when W becomes smaller, the electric motor 24 remains at the rotational speed of N2, and the rotational speed of the electric motor 20 decreases.

When W becomes 81, the rotation speed of the electric motor 24 remains at N2 and the rotation speed of the electric motor 20 becomes N+.

When W further decreases, the motor 24 remains at the rotational speed of N2, and the electric motor 20 remains at the rotational speed of N1. W further decreases, and when W reaches A2, the electric motor 24 stops, the electric motor 20 reaches a rotational speed of N1, W decreases, and when W reaches 82, the electric motor 2o also stops.

In addition, in the above, a 2I cold W fan 2 is used as an example.
2. The case where the specifications of the motors 26 are the same has been described, but these may be different, and the specifications of the electric motors 24 and 20 may be different.

[Effects of the Invention] As explained above, the present invention is capable of maintaining the engine cooling water temperature at the set temperature and keeping the cooler high pressure at the set pressure even when the condenser and radiator are arranged in series with respect to the air flow. Since the control is performed using the minimum necessary ff1ffi that satisfies both the requirements of maintaining the noise level, the noise level is also low and energy can be used effectively.

Furthermore, by continuously changing the rotational speed of the two cooling fans, there is no stepwise change in the rotational speed unlike in the prior art, and therefore noise generation is prevented.

[Brief explanation of drawings]

Fig. 1 is an explanatory diagram of the configuration of the present invention, Figs. 2 and 3 are p-i diagrams of refrigerant, Fig. 4 is a diagram showing temperature changes in the air flow direction of air passing through a condenser, Figure 5 shows a control flowchart of the present invention, Figure 6 shows the relationship between the calculated value W and the rotation speed of the cooling fan, and Figures 7 and 8 show the arrangement of the condenser, radiator, and cooling fan. It is a diagram. 20... First electric motor 22... First cooling fan 24... Second electric motor 26... Second cooling fan 28... Capacitor 30... Radiator 36... Evaporator 43 ... Fuel injection 011 control device 44 ... Arithmetic circuit 46 ... Outside temperature sensor 48 ... Vehicle speed sensor 50 ... Water temperature sensor 52 ... High pressure pressure sensor 54 ... Low pressure 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 the cooling air cooled by each of these cooling fans is A radiator and a cooler capacitor are arranged in series with each other in the flow path, and the first electric motor and the second electric motor are connected to each other in series.
A control device for a vehicle cooling fan that cools a radiator and a capacitor by controlling the voltage applied to an electric motor, comprising an arithmetic circuit having a built-in cooling control program for both the cooler capacitor and the radiator,
The air volume required to maintain the engine cooling water temperature at the set temperature is compared with the air volume required to maintain the condenser pressure at the set pressure, and the air volume is determined to be the larger of these required air volumes. 1. A control device for a cooling fan for a vehicle, characterized in that the rotation of a first cooling fan and a second cooling fan are controlled. (2) The device according to claim 1, which includes a high pressure sensor that detects high pressure in the refrigerant circulation path of the cooler, and a low pressure sensor that detects the low pressure in the refrigerant circulation path of the cooler. A refrigerant temperature sensor that detects the refrigerant temperature near the evaporator outlet in the refrigerant circulation path of the cooler, an outside air temperature sensor that detects the outside air temperature of the vehicle, a water temperature sensor that detects the engine coolant temperature, and a vehicle speed sensor. A vehicle speed sensor that detects the air volume required by the cooling fan to maintain the cooler high pressure at the set pressure, the cooler high pressure detected by the high pressure sensor, the cooler low pressure detected by the low pressure sensor, and the refrigerant temperature. Calculated from the refrigerant temperature near the evaporator outlet detected by the sensor, the outside temperature detected by the outside air temperature sensor, and the vehicle speed detected by the vehicle speed sensor, calculates the air volume required by the cooling fan to maintain the engine coolant temperature at the set temperature. is calculated from data from a fuel injection amount control device, outside air temperature detected by an outside air temperature sensor, engine coolant temperature detected by a water temperature sensor, and vehicle speed detected by a vehicle speed sensor. Cooling fan control device.