JPS61229919A - Cooling fan controller for vehicle - Google Patents

Abstract

PURPOSE:To reduce the power consumption by operating the voltages necessary for cooling a radiator and a condenser independently through independent arithmetic unit while setting the voltage to be applied onto a condenser cooling fan at the minimum necessary level. CONSTITUTION:On the basis of engine cooling water temperature, outer air temperature, etc., second arithmetic unit 44 will operate second voltage necessary for controlling the engine cooling water temperature to predetermined setting level only through second cooling fan 24 then drive second cooling fan 24 on the basis of said voltage. Upon turning on of cooler, first arithmetic unit 42 will function to operate the first voltage necessary for controlling the high pressure of cooler to predetermined setting level only through the first cooling fan 20 on the basis of cooling temperature, etc. thus to drive the first cooling fan 20 on the basis of the operated differential voltage level between the first and second operated voltage levels. Consequently, power consumption can be saved considerably.

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 more particularly to a control device for a cooling fan for a vehicle that uses an electric motor to drive a cooling fan that cools a cooler condenser and a radiator.

[Prior Art] The condenser in a vehicle cooling system is cooled by a cooling fan, which uses the rotational force of the engine crankshaft transmitted through a belt. There are some types that use electric motors, and in recent years, many vehicle cooling systems that use electric motors have been used. A cooling fan using this electric motor operates while the compressor is operating, and when the compressor is turned on, a voltage of 12V is applied to the electric motor to start, and when the compressor is turned off, the driving of the electric motor is stopped.

In a cooling fan using such an electric motor, preventing noise from the cooling fan is an important issue. That is,
As mentioned above, each time the electric motor is turned on, the rotation speed of the cooling fan suddenly rises from 0 and temporarily generates a loud noise, which can be extremely annoying to the driver and other passengers, causing discomfort. give.

Further, in such a device, it is necessary to perform sufficient drive control in response to changes in the environment and to reduce power consumption. In other words, when the vehicle is traveling at high speed, for example,
Since the vehicle-speed wind that is taken into the vehicle is also extremely high-speed, this vehicle-speed wind alone may be sufficient to cool the condenser, and even in this case, conventionally, if the compressor is on, the electric motor is driven. This wastes energy.

By the way, cooling of a condenser in a vehicle cooling system is always performed with consideration to the cooling of a radiator, and conventionally there are two types of radiator and condenser arranged in parallel and in series. That is, the seventh
As shown in the figure, a radiator cooling fan 10 and a condenser cooling fan 12 are arranged in parallel, and a radiator 14 and a cooler condenser 16 are arranged in parallel along the flow path of the air blown by these cooling fans. As shown in FIG. 8, a radiator 14 and a condenser 16 are arranged in series along a flow path of air blown by a radiator cooling fan 10 and a condenser cooling fan 12 arranged in parallel. It is the same thing.

To cool the radiator 14, the cooling water inside the radiator 14 is heated to 85°C to 95°C to cool the engine.
The temperature is maintained at around °C, and when the coolant temperature reaches the set value or higher, the radiator cooling fan 10 is automatically turned on to start cooling the radiator, and the coolant temperature reaches the set value. The radiator cooling fan is automatically turned on when the following conditions are reached:

Particularly, a device in which the radiator 14 and the condenser 16 are arranged in series has the advantage that part of the condenser cooling can be performed simultaneously by driving only the radiator cooling fan 10.

[Problems to be Solved by the Invention] LL Anti-propagation I" In the vehicle cooling fan described above, it is desired to have a device that consumes as little power as possible and prevents noise. The following devices are examples of improved devices that save money.

That is, the rotation speed of the electric motor of the capacitor cooling fan 12 is set to LO (applied voltage 6V) and Hi (applied voltage 12V).
) When the compressor is turned on, the electric motor is rotated at LO, and when the high pressure of the refrigerant from the compressor reaches 18 Kg102 or higher, or when the water temperature in the radiator 14 reaches 93°C or higher, A device has been put into practical use that controls the rotational speed of the electric motor in two stages, in which the electric motor is rotated at Hi.

However, this device has the problem that even when the vehicle is running at high speed, where the wind alone can sufficiently cool the condenser, the electric motor continues to rotate at the LO speed, resulting in unnecessary energy consumption. was there.

Also, in terms of noise prevention, the change in noise is somewhat improved compared to when a conventional cooling fan is rotated with an applied voltage of Ov and 12V, but even so, the electric motor is turned off,
Since the motor is driven in three steps, Lo and Hi, the motor goes from OFF to LO.

There was a problem that the change in noise when switching from LO to Hl was still annoying.

On the other hand, as a conventional device for preventing noise, there is also a device that calculates and continuously changes the rotation speed of the motor of the condenser cooling fan 16 so that the cooler high pressure becomes the set pressure. This is because the rotation of the electric motor changes continuously and slowly, so there are no step-like changes and the driver does not feel it is jarring.

However, although such a device is effective for a device in which the radiator 14 and the capacitor 16 are arranged in parallel as described above, it is effective for a device in which the radiator 14 and the capacitor 16 are arranged in series (according to the present invention).
However, there is a problem in that it is extremely wasteful in terms of power consumption. That is, when the radiator cooling fan 10 is rotating to cool the radiator 14, the condenser is also being cooled, so it is not possible to control the rotation of the condenser cooling fan 12 to follow changes in the cooling of the condenser 16. As a result, power is wasted.

Furthermore, in a device in which the radiator 14 and the condenser 16 are arranged in series, the control device for the radiator cooling fan 10 and the condenser cooling fan 12 is formed by integrating one computing device, and this one computing device The voltages applied to the motors of the radiator cooling fan 10 and the condenser cooling fan 12 are computationally controlled.

However, coolers are not only installed when the vehicle is completed, but are also often installed at the time of or after the vehicle is sold. There is a problem in that incorporating this into a vehicle is extremely wasteful unless a cooler is attached, and also increases the manufacturing cost of a control device for a vehicle cooling fan, making it uneconomical.

The present invention has been made in order to solve the above-mentioned conventional problems, and its purpose is to provide condenser cooling with a device in which the radiator cooling and the condenser are arranged in series even when the cooler is installed after the vehicle is manufactured. An object of the present invention is to provide a control device for a cooling fan for a vehicle, which can reduce power consumption and effectively suppress noise generated by a condenser cooling fan.

[Means and operations for solving the problems] In order to achieve the above object, the present invention consists of the following configuration.

(a) A first cooling fan driven by a first electric motor and a second cooling fan driven by a second electric motor? A radiator and a cooler capacitor are arranged in series along the flow path of the air blown by each of these cooling W fans, and the voltage is applied to the first electric motor and the second electric motor. It is a control device for a vehicle cooling fan that cools the radiator and condenser by controlling the voltage.

(b) A first calculation device that calculates a first voltage to be applied to the first electric motor necessary for controlling the high pressure of the cooler to a desired set value using only the first cooling fan; Separately comprising a second calculation device that calculates a second voltage to be applied to the second electric motor necessary to control the engine cooling water temperature in the radiator to a desired set value using only the cooling fan.

(c) Cool the radiator by driving a second cooling fan based on the second voltage calculation value, and based on the voltage calculation value obtained by subtracting the second voltage calculation value from the first voltage calculation value. The present invention is characterized in that the first cooling fan is driven in conjunction with the second cooling fan to cool the condenser.

According to the above configuration, first, the second arithmetic unit calculates the second voltage that controls the engine coolant temperature to a constant set value using only the second cooling fan, based on the current engine coolant temperature, outside air temperature, etc. is calculated, and the second voltage is calculated based on this second voltage.
drive the cooling fan.

When the cooler is turned on, the first calculation device operates and calculates the first voltage for controlling the high pressure of the cooler to a constant set value using only the first cooling fan from the refrigerant temperature, etc. The first cooling fan is driven based on the voltage calculation value that is the difference between the first voltage calculation value and the second voltage calculation value. At this time, the second cooling fan is also being driven.
The condenser is cooled by both the first and second cooling fans.

[Embodiments] Hereinafter, preferred embodiments of the present invention will be described based on the drawings. Note that the same members as those in the conventional device are given the same reference numerals and explanations will be omitted.

FIG. 1 shows a control device for a vehicle cooling fan, in which a first cooling fan 20 is directly connected to the rotation shaft of a first electric motor 18, and a second electric motor 22 is directly connected to the rotation shaft. The second cooling fan 24 is arranged in parallel, and the radiator 14 and the condenser 16 are arranged in series along the flow path of the air blown from each cooling fan 20.24.

This capacitor 16 is connected to an expansion valve 26. Evaporator 28. A compressor 30 and the like are connected to form a refrigeration cycle.

Therefore, the refrigerant sealed in the condenser 16 circulates within the refrigeration cycle, transferring heat from the low heat source of the air inside the vehicle to the high heat source of the outside air, thereby performing cooling.

That is, the liquefied refrigerant in the condenser 16 passes through the expansion pulp 26 and is adiabatically expanded by the throttling action of the valve at this time. The refrigerant, which has become atomized by lowering its pressure and temperature, is supplied to the evaporator 28, where it absorbs the heat inside the vehicle interior, vaporizes the refrigerant, and continues to expand isothermally. Provides a cooling effect. Next, the refrigerant that has become superheated vapor is sucked into the compressor 30, becomes a high-temperature, high-pressure gas through adiabatic compression, and reaches the condenser 16, where the cooling fan releases heat to the outside air and returns to the state of liquefied refrigerant. .

In this case, a temperature sensing cylinder 32 is provided at the outlet of the evaporator 28, and this temperature sensing cylinder 32 allows the evaporator 28 to
The refrigerant temperature near the outlet of the expansion pulp 26 is sensed and the opening/closing layer of the valve of the expansion pulp 26 is changed. Therefore, if the refrigerant is heated in the middle of the evaporator 28 and becomes completely gaseous, and the temperature rises to a point where the refrigerant cannot effectively perform the cooling action,
The thermosensor tube 32 senses that the refrigerant temperature is high, and based on this temperature, the passage in the expansion valve 26 is enlarged to allow a large amount of refrigerant to flow, and all of the refrigerant is removed just before the outlet of the evaporator 28. It can be adjusted to become a gas.

Conversely, if there is still a considerable amount of refrigerant remaining in the form of droplets at the outlet of the evaporator 28, the thermosensor 32 will sense that the refrigerant temperature is low, so the passage inside the expansion valve 26 will be made smaller and the refrigerant will be removed. The flow can be reduced, and the refrigerant is controlled so that it is all vaporized just before the outlet of the evaporator 28.

In contrast to the above-described cooling effect in the vehicle interior, the engine is cooled by supplying hot water warmed by the engine 34 from the water jacket of the engine 34 to the radiator 14, as is well known. After being cooled down to a predetermined temperature, the water is returned to the water jacket of the engine 34 via the water pump 36.

A characteristic feature of the present invention is that a device is separately provided for calculating the motor voltage of the cooling fan necessary for cooling the radiator and the condenser in a separate and independent state, and the first cooling fan 20 for the condenser is provided separately. This is to suppress the operation as much as possible, and the present invention focuses on the fact that the radiator 14 and the condenser 16 are arranged in parallel in the air flow path for cooling.

That is, the condenser 16 is cooled by air blown not only from the first cooling fan 20 but also from the second cooling fan 24, and the radiator 14 is cooled by not only the second cooling fan 24 but also the first cooling fan 24. It is also cooled by air blown from 20. Therefore, when the second cooling fan 24 for the radiator 14 is operated, the cooling of the condenser 16 for maintaining the cooler high pressure at the set pressure is transferred to the first electric motor 18 of the first cooling fan 20. It is understood that this can be done by applying a small voltage.

Since the present invention treats the radiator 14 and the condenser 16 separately, the first and second electric motors 18.22 that drive the first and second cooling fans 20.24 have a first electric motor controller 38 and a A second motor control device 40 is connected to the first motor control device 38, and a first calculation device that calculates a first voltage to be applied to the first electric motor 18 is connected to the first motor control device 38. A second calculation device 44 that calculates a second voltage of the second electric motor 22 is connected to the motor control device 4o. Then, the first calculation device 42 calculates the electric mm voltage necessary to control the high pressure of the cooler to a desired set value using only the first cooling fan, and the second
The calculation device 44 calculates the motor voltage necessary to control the engine cooling water temperature in the radiator to a desired set value using only the second cooling fan.

In vehicles that are not equipped with a cooler, the equipment constituting the refrigeration cycle and the first electric
Since the first cooling fan 20 to which the l118 is connected, the first motor control device 30, and the first calculation device 42 are not installed, the 2 motor control device 1 (via 40
The cooling fan 24 is rotated. A transistor can be used as the second motor control device 40, and in this case, the voltage applied to the second motor 22 is set by changing the duty ratio by pulse duty control.

Further, the second arithmetic unit 44 is connected to receive signals from an outside temperature sensor 46, a vehicle speed sensor 48, and a water temperature sensor 50, and is further connected to a fuel injection m control bag @52. A signal representative of the fuel injection period is supplied to a second computing device 44 .

The second arithmetic unit 44 performs computations based on the information supplied from each of these sensors, and the computations of the second arithmetic unit 44 will be described in detail below.

The voltage applied to the second electric motor 22 required to maintain the temperature of the engine cooling water in the radiator 14 at the set temperature tse using only the second cooling fan is calculated as a second voltage calculation value using the following equation.

W-2=ni-o (K-a XhXm/ (tse-t
o) − to −+3W”) b+1(−s+(tW −tse
)+C-e... (101) Here, W'2: Voltage m required to bring the engine cooling water temperature to the set temperature tse when the cooler is not attached: Fuel injection per unit time Listening fuel injection can Based on signals from control equipment 52. ) W: Vehicle speed detected by vehicle speed sensor 48 tW: Cooling water temperature detected by water temperature sensor 50 tO: Outside temperature tse detected by outside temperature sensor 46 Target value of cooling water temperature to be kept constant h: Per unit weight The calorific value of the fuel (approximately 10,200 kcal/Ng) K"u * K'w + K'o, K'+4,
Ce −+ atb is a constant. However, a = approximately o, s, b
- approximately 2.

Here, 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. Therefore, the amount of heat supplied to the cooling water can be determined from the amount of fuel injection, while the heat m radiated from the cooling water mainly depends on the outside temperature, the vehicle speed (wind speed due to the running wind),
The voltage required to maintain the cooling water temperature at the set temperature tse is calculated by the above equation (101), which is influenced by the rotational speed of the cooling fan (wind speed by the cooling fan).

As described above, when the cooler is not installed, the second voltage calculation value W -2 causes the first electric power 1lI2
2 is driven, and the radiator 14 is driven by the second cooling fan 24.
cooled by

Next, when the cooler is attached, the configuration is as shown in FIG. 1, and the attached first calculation bag!
! The first electric motor drives the first cooling fan 20 at 42! 118 voltage is calculated. In this case, the refrigeration cycle includes a high pressure sensor 54 that detects the high pressure of the cooler, a low pressure sensor 56 that detects the low pressure of the cooler, and a refrigerant temperature sensor 5 that detects the refrigerant temperature near the evaporator outlet.
8 may be arranged, and a refrigerant flow meter 60 may be further attached, or the refrigerant flow rate may be determined by another calculation means.
stomach. The first arithmetic device f42 is connected to the second arithmetic device 44, and outputs a signal indicating that the cooler is attached to the second arithmetic bag [44]. , outside temperature data, vehicle speed data, etc. necessary for the calculation are received from the second calculation device 44.

Under the above configuration, the first calculation device 142 calculates the applied voltage of the first electric Ja 18 necessary to bring the cooler high pressure to the set pressure Ps using only the first cooling fan 20. Below is the calculation device of cylinder 1! 42 will be explained in detail.

First of all, the sum of the amount of heat absorbed by the refrigerant from the air inside the vehicle by the evaporator 28 and the compression work compressed by the compressor 30 is equal to the amount of heat radiated by the condenser 16, so the amount of heat absorbed by the evaporator 28 is The sum QO+QD of Qe and the calorific value QEI of the compression work of the compressor 30 may be cooled by the condenser 16 so that the high pressure (pressure at the condenser 16) becomes the set pressure Ps. in fact,
The higher the amount of cooling air in the condenser 16, the lower the high pressure becomes, and conversely, the smaller the amount of cooling air, the higher the high pressure becomes. By controlling the amount of cooling air in this way, the high pressure can be brought to the set pressure ps.
This means that it can be controlled at a rotation speed of 0, and as a result, the first
Electric! This is done by controlling the voltage applied to l118.

Furthermore, while the vehicle is running, the capacitor 16 is cooled by the wind at the vehicle speed, so the capacitor 16 is cooled by the wind at the vehicle speed and the first cooling fan 20. The voltage calculation value is calculated so that the high pressure of the cooler becomes the set pressure ps.

That is, the voltage to be applied to the first motor 18 of the first cooling fan 20 necessary to bring the high pressure to the set pressure Ps, that is, the first voltage calculation value is expressed by the following equation.

+3 (tc - ts) + C (1) where, Qe: Amount of heat absorbed in the evaporator 28 Qp: Calorific value conversion of compressor compression work tS: Refrigerant temperature with respect to the set pressure ps of the high pressure in the condenser 16. This is uniquely determined by the relationship between refrigerant pressure and evaporation (condensation) temperature.

tO: outside temperature, W: vehicle speed tC: refrigerant temperature (condensing temperature) in the condenser 16 K +
#K 21 K i * a e b sc c Ha constant theal.

Next, it will be shown that the above values other than the constants can be obtained from the sensor shown in FIG.

First, to explain the calculation of the endothermic IQe in the evaporator 28, the P-i diagram (Mollier diagram) of the refrigerant shown in FIG.
Therefore, Qe = G (i work ■).

Here, G is the refrigerant flow rate, lI is the enthalpy at the outlet of the refrigerant evaporator 28, and i■ is the enthalpy at the inlet of the refrigerant evaporator 28.

Then, the above G is determined by a refrigerant flow rate detection means.

In other words, the flowmeter 6 installed in the refrigeration cycle shown in FIG.
It is determined by the detection signal from 0. As another method, the high pressure pc detected by the high pressure sensor 54, the low pressure pe detected by the low pressure sensor 56, and the refrigerant temperature sensor 58 provided near the outlet of the evaporator 28 are used.
It can be determined from the detected temperature near the outlet of the evaporator 28 using the following equation.

G-ζ"' 207 (PC-Po) "" (2
) Here, S: Passage area of the expansion pulp 26 ζ: Flow coefficient of the passage of the expansion valve 26 γ: Ratio of refrigerant at the evaporator outlet 1M a: Tfi force acceleration P output High pressure High pressure detected by the pressure sensor 54 Pressure Pe: low pressure detected by the low pressure pressure sensor 56, and ζ, S,
γ changes with Pe and tI, respectively. Also, equation (2) can be written as G-8-(iqi)j-.

ζ・8 books is a function of Pe and tI, so ζ-8r-F (Pe, machined) 2Qγ Totoru.

Note that F+ (χ, y) is a function. Therefore, the refrigerant flow mG is 0'''R (Pe・1 t)50'', (3), and by measuring and determining F+ (Pe, tI) in advance, the refrigerant flow rate G can be determined. Yes, pe and tpc are detected by each sensor.

Next, while referring to FIGS. 2 and 3, the evaporator 28
The calculation of the refrigerant enthalpy i at the inlet will be explained, but first, the enthalpy of the saturated liquid line A to B of the refrigerant is determined.

The enthalpy 1 at any point χ (pressure P) on the saturated liquid line in the figure is expressed as 1=F2 (P) (F2 (χ) is a function).

By the way, the enthalpy 1■ at the entrance of the evaporator 28 in FIG. 2 is obtained by subtracting the difference Δi■ between the enthalpies at points ■' to ■ from the enthalpy at the point ■.

That is, l - f - i yl ' - Δi -.

Here, if the temperature difference between points ■′ and ■ is Δtm and the specific heat of the refrigerant liquid is C, then Δ′ I[=CL・Δtm, so 1−i−i−−Q・IVil[L Δtm becomes. On the other hand, 1III' is the high pressure pressure sensor 22
is calculated by equation (4) from the detected high pressure Pc.

This enthalpy i ′ is i ′−F2 (PC)
■■ Therefore, the enthalpy ■ is expressed by the following formula.

i ■= F 2 (P C) CI ・Δtm・
(5) Here, Δt is generally around 5°C and may be a constant value, and since C4 is also a constant, I■ can be easily determined.

Next, the enthalpy +1 at the exit of the evaporator 28 is determined. First, the low pressure Pe detected by the low pressure sensor 56
Assuming that the enthalpy i' of the point ■' on the saturated liquid line when

i■'-F2 (Pe)...(6) Then, the enthalpy i' of the point ' on the saturated steam line is obtained by the following equation.

iku'-i■=+r where r is the latent heat of vaporization. This r can be found once the pressure is determined, and is expressed by r-Fi (P) ·-(7'). Now, the pressure at the work point is the low pressure pressure sensor 5.
Since 6 is the detected low pressure, the latent heat of vocalization at this time is r-Ft (Pe) - (8).

On the other hand, the enthalpy i of the work point is the enthalpy of the work point plus the difference in enthalpy from work to work' by Δf work.

In other words, it becomes i - i - + Δf.

I Here, Δi is the temperature at one point tI, and the temperature at one point I is t
', then ■ A i I = Cp A t engineering・IIIΔt
−t −t ”. Cp is specific heat at constant pressure.

Here, t - is the pressure and evaporation temperature of the refrigerant shown below. It is obtained from the relational expression.

j = F4 (P) (9) Next, by substituting the low pressure pe detected by the low pressure sensor 56 into equation (9), t knee, which is the evaporation temperature at that time, can be obtained. That is, i ′=F4 (Pe) −・
(1o)■ becomes. In addition, when measuring the temperature at one point, the detected temperature value detected by the refrigerant temperature sensor 58 is used as is. Therefore, Δ =
”F4 (Pe), and Δ is calculated as F4 (Pe).
t knee FI (Pe)) - (11>. Therefore, the enthalpy t knee i ■'+ r + Δtl of one point can be found from equations (6), (8), and (11), and i knee F2 (Pe) + F 3 (P e) +
cp (tl F4 (Pe)) ... (12
).

Therefore, the heat absorption fAQe in the evaporator 12 is oe=
It is obtained by substituting formulas (3), (5), and (IrV 2) into a<+ + >, and Qe −Fl (Pe, is calculated) [F2 (Pe)
+F3 (Pe)+Cp[F4 (Pa)) (
F2 (PC) CI ・Δ1■)]...(13
) Next, the heat quantity conversion Ql of the compressor compression work in equation (1)
) calculation will be explained. If the compression work of the compressor 30 is L...-(14) Here, G is the refrigerant flow rate, n is the polytropic index, Pl is the refrigerant pressure at the inlet of the compressor 30, F2 is the refrigerant pressure at the outlet of the compressor 30, υ G is the refrigerant specific volume at the inlet of the compressor 30, and G is obtained from equation (3),
Approximately substitute the specific heat ratio K for n<P+: PC, F
2 #PC.

Also, υ is found from P IvI = R'T+,
Here, T and -273+tR are the gas constants of the refrigerant, so the following equation is obtained.

Therefore, by substituting equations (3) and (15) into equation (14), P+
By substituting =Pe and F2 =Pc, the compression work becomes Bie... (16). Calorie conversion Q of compressor compression work from the above equation
Find p from Ql) - AL [A is the heat damage caused by work I (1/A is the heat damage ff1)].

Therefore, the following equation is obtained from equation (16).

Ql) = Δ・FI (pe, 1I) qi: As explained above (1), (9), (13).

From equation (17), the high pressure of the capacitor 16 is set to a constant value P
The first N pressure to be applied to the first electric motor 18 can be calculated to make the voltage s. However, ts is calculated using equation (9).
=F+ (Ps), and tc is also determined from tc=F4 (Pc) using equation (9).

That is, the first voltage calculation value W1 required to make the high voltage power a constant value ps is +KJ (F4 (PC) - F4 (PS))
+C... (18) Here, Qe = FI (Pe, work) 5 X [F2 (Pe) + F3 (Pe) + cp (tI
F4 (Pe)) −(F2 (PC)−C, −at■) ] ++
(19゜Ql)-A-FI (Pe,'j 工) (
PCPe-x[(Pc/Pe)-1],
0. (2o.

, FI (χ, V), F2 (χ), F3 (χ
), F4 (χ) are predetermined functions.

Further, PS is a value predetermined by the set value of the high pressure of the capacitor 16, to is the outside temperature detected by the outside air temperature sensor 46 and data sent from the second calculation device 44, and W is detected by the vehicle speed sensor 48. pe is the low pressure detected by the low pressure sensor 56, pe is the refrigerant temperature at the outlet of the evaporator 28 detected by the refrigerant temperature sensor 58, and Cp is the refrigerant gas pc is the high pressure detected by the high pressure sensor 54, C1 is the specific heat of the refrigerant liquid, ΔjI (is a constant value (constant)
, K I * K 2 @ K 3 * a e b
e C is a constant, a has a value of approximately 0.5, and b has a value of approximately 2.

Next, the second arithmetic unit 44 determines the voltage to be applied to the second electric motor 22 that is necessary to maintain the engine cooling water temperature at the set temperature tse using only the second cooling fan 24 when the cooler is installed. calculate.

First, the air resistance valve due to the attachment of the capacitor 16 is corrected using equation (101). This is done by changing the value of ni=o in equation (101) to a new constant KIIIK+3. Furthermore, the air that has passed through the condenser 16 due to the operation of the cooler is heated by the condenser 16 and its temperature increases, as shown in FIG. 4, and then passes through the radiator 14. Therefore, the outside temperature t in equation (101)
The temperature of the air after passing through the condenser 16 must be substituted for o.

The temperature of the air after passing through the condenser 16 is determined by the following equation.

ta −Atc + (1-A)to...(102)
Here, ta is the air temperature after passing through the condenser 16, t
c is the refrigerant temperature (condensation temperature) in the condenser 16,
The high pressure detected by the high pressure sensor 54 is determined from the relational expression between the pressure and the evaporation temperature (condensation temperature) of the refrigerant, that is, t=F+ (P) in equation (9). Therefore, tc=F
+ (PC), where Pc is the cooler high pressure detected by the high pressure sensor 54, to is the outside air temperature detected by the outside air temperature sensor 46, and A is a constant.

Also, equation (102) is expressed as t when the cooler is not operating.
Since c=to, if this is substituted into equation (101), ta=to. In other words, when the cooler is not operating, the air temperature after passing through the condenser is the same as the outside temperature, which means that it can be used as is even when the cooler is not operating.

Therefore, when the cooler is installed, the voltage that should be applied to the second electric motor 22 necessary to maintain the engine cooling water temperature at the set temperature tse using only the second cooling fan, that is, the second voltage calculation value W2 is obtained by changing the constants in equation (101) and substituting ta, that is, AtC+(1-A)to, into equation (102) instead of the outside temperature to, resulting in the following equation.

W2 = Kn [KQX h xm/ (t 5o
-AtC-(1-A) to )-K13W a
) b ]+Kg(tW-tSe)+Ce...
(1oa) However, Ku'-KT2-1KH-KI4-
, tc wF4 (PC).

The second voltage calculation value W2 obtained in the above manner is
The second calculation value voltage is supplied from the second calculation device 44 to the second motor control device 40 and applied to the second electric motor 22 . At the same time, the second calculation value output is supplied to the first calculation device 44, and the first calculation device f42 subtracts the second voltage calculation value from the first voltage calculation value obtained by this device. The calculated voltage value is supplied to the first motor control device 38.

Therefore, the first electric motor 18 that drives the first cooling fan 20 for cooling the capacitor 16 has a driving voltage less that of the cooling by the second cooling fan 24 for cooling the radiator 14. will be applied.

In this case, the first cooling fan and the second cooling fan may have different cooling capacities, and when subtracting the second voltage calculation value from the first voltage calculation value, the cooling fan This is done taking into account ability.

The configuration of this embodiment has been described above. Next, the operation of this embodiment will be explained based on FIG. 5.6.

FIG. 5 shows a control flowchart of the second arithmetic unit 44, and in step 201, the outside air temperature, vehicle speed, and engine coolant temperature detected by various sensors such as the outside air temperature sensor 46 are read. Next, in step 202, fuel injection amount information is read from the fuel injection amount control device 52, and then the process moves to step 203.

In this step 203, it is determined whether the cooler is attached or not based on the signal output from the first calculation bag [42]. If a cooler is attached, the process moves to step 208, in which data on the high-pressure case 54 is received, and then in step 209.
Then, the applied voltage required to cool the radiator 14 only by the second cooling fan 24, that is, the second voltage calculation value W2, is calculated according to equation (103). Then, the process moves to step 206.

Further, if it is determined in step 203 that the cooler is not installed, the process moves to step 204, and in step 204, the radiator 14 is cooled only by the second cooling fan 24 in accordance with the above equation (101). The applied voltage required to do this, that is, the second voltage calculation value W''2, is calculated.Next, the process moves to step 205, where the value of W'2 is entered as W2 obtained in step 209, and the process proceeds to step 206. Transition.

In this step 206, it is determined whether the second voltage calculation value W2 is larger than the predetermined value A1, and if W2 is larger than 81, the process moves to step 210. In this step 210, a voltage W2 is applied to the second electric motor 22 that rotates the second cooling fan 24 in order to maintain the engine cooling water temperature at the set concentration tse.

Further, if W2 is smaller than the predetermined value A+ in step 206, the process moves to step 207, and this step 2
In step 07, it is determined whether W2 is larger than a predetermined value A2 (A2<A+), and if W2 is smaller than A2, the process moves to step 211.

In this case, since the engine cooling water temperature is maintained at the set temperature tse, there is no need to drive the second electric motor 22, and in step 211 the second electric motor 85 is
122 stops.

Further, when it is determined in step 207 that W2 is larger than A2, since W2 is a value between A2 and A1, the state is maintained as it is, and the process moves to step 212.

That is, if the second cooling fan 24 is rotating, it continues to rotate at the same rotation speed, and if it is in a stopped state, it continues to remain stopped. And step 21
In step 2, a reset is performed and the process returns to step 200, and this series of operations is repeated.

Note that the predetermined values A2 to A+ are hysteresis,
Hunting of the second electric motor 22 between ON and OFF is prevented by a slight change in W2.

Next, FIG. 6 shows a control flowchart of the first calculation bag W142, and in step 301, the high pressure sensor 54
Cooler high pressure pressure, low pressure pressure, detected by various sensors such as
Read the evaporator outlet refrigerant temperature. Next, in step 302, the refrigerant flow IG is calculated according to the above equation (3),
The process moves to step 303.

In step 303, the amount of heat absorbed by the evaporator is calculated according to equation (19), and the process moves to step 304.

In this step 304, the heat ffi conversion Qp of the compression work of the compressor 30 is calculated according to the above equation (20),
The process moves to step 306 via step 305.

In this step 305, the outside air temperature data is converted to the second data.

In step 306, vehicle speed data is received from the second arithmetic unit 44, and the process proceeds to step 307.

In this step 307, the first
The voltage applied to the electric motor 18, that is, the first voltage calculation value W1, is calculated according to the above equation (18). Next, in step 308, the second calculation bag @42 obtained
The calculation value W31 is obtained by subtracting the second voltage calculation value W2 from the first voltage calculation value W+.
Calculate x=W2-W+. And step 309
to move to.

In this step 309, it is determined whether the voltage calculation value W3 obtained in the step 308 is larger than a predetermined value B1, and if W3 is larger than 81, the process moves to step 311. In this step 311, the first cooling fan 2
This is a state in which a rotation of 0 is required, and a voltage of W is applied to the first electric motor 18.

Further, when W3 is smaller than B1 in step 309, the process moves to step 310, and in this step 310, W3 is smaller than B1.
, is larger than 82 (82<8+). Next, if W3 is smaller than 82, the process moves to step 312, and in this step 312, since the current state does not require rotation of the first cooling fan 20 to maintain the cooler high pressure at the set pressure ps, the first cooling fan 20 is rotated. The electric motor 18 is stopped.

Also, when W3 is larger than 82, this W is B2
to B1, and the current state is maintained as is. That is, 82 to B1 are considered to be hysteresis,
If the first cooling fan 20 is rotating, it continues to rotate at the same rotation speed, and if it is stopped, it remains stopped. Next, in step 313, a reset is performed, and the process returns to step 300 to repeat the series of operations described above.

[Effects of the Invention] As described above, according to the present invention, in the electric motor that drives the cooling fan, the voltages required to separately cool the radiator and the capacitor are calculated using separate calculation devices, By making it possible to set the voltage applied to the condenser cooling fan to the minimum required voltage, it is possible to significantly reduce power consumption in the vehicle cooling system, and the rotation of the cooling fan can be set in steps from 0 to 12V. There is no sudden change, and the driver or the like does not feel harsh.

Furthermore, by making the arithmetic unit separate, the cooling system can be easily installed at low cost even after the vehicle is sold.

[Brief explanation of drawings]

Fig. 1 is an explanatory diagram showing a preferred embodiment of the control device for a vehicle cooling fan according to the present invention, Figs. 2 and 3 are P-1 diagrams of the refrigerant, and Fig. 4 shows the refrigerant passing through the condenser and radiator. An explanatory diagram showing temperature changes with respect to air flow, FIG. 5 is a flowchart showing control of the second calculation device, FIG. 6 is a flowchart showing control of the first calculation device, FIGS. 7 and 8 FIG. 2 is an explanatory diagram showing the arrangement of a capacitor and a radiator. 14... Radiator 16... Capacitor 18... First electric motor 20... First cooling fan 22... Second electric motor 24... Second cooling fan 26... Expansion pulp 28...
Evaporator 30 ... Compressor 38 ... First motor control device 40 ... Second motor control device 42 ... First calculation device 44 ... Second calculation device 46 ... Outside temperature Sensor 48...Vehicle speed sensor 50...Water temperature sensor 52...Fuel injection amount control device 54...High pressure sensor 56...Low pressure sensor 58...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, and a flow path for air blown by each of these cooling fans is provided. In a control device for a vehicle cooling fan that cools the radiator and the capacitor by arranging a radiator and a cooler capacitor in series along the radiator and controlling the applied voltage to the first electric motor and the second electric motor. , a first calculation device that calculates a first voltage to be applied to the first electric motor necessary to control the high pressure of the cooler to a desired set value using only the first cooling fan; and a second cooling fan. a second calculation device that calculates a second voltage to be applied to the second electric motor necessary for controlling the engine coolant temperature in the radiator to a desired set value, and A second cooling fan is driven to cool the radiator based on the second voltage calculation value, and the first cooling is performed based on the voltage calculation value obtained by subtracting the second voltage calculation value from the first voltage calculation value. A control device for a cooling fan for a vehicle, characterized in that the fan is driven and shared with a second cooling fan to cool a condenser. (2) The device according to claim (1), which includes a high pressure sensor that detects the high pressure of the cooler, a low pressure sensor that detects the low pressure of the cooler, and a refrigerant temperature near the outlet of the evaporator connected to the cooler. a refrigerant temperature sensor that detects the temperature of the outside air, an outside temperature sensor that detects the outside air temperature, a water temperature sensor that detects the engine coolant temperature, and a vehicle speed sensor that detects the vehicle speed, and the first arithmetic unit is configured to detect the temperature of each of the sensors. The first voltage calculation value is calculated based on the cooler high pressure, the cooler low pressure, the refrigerant temperature near the evaporator outlet, the outside air temperature, and the vehicle speed, and the second calculation device calculates the outside air temperature output from each of the sensors. A control device for a cooling fan for a vehicle, characterized in that a second voltage calculation value is determined based on a cooling water temperature, a vehicle speed, and a fuel injection amount output from a fuel injection amount control device.