JP2685671B2 - Cooling device drive controller - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drive control device for a cooling device which cools air by two electric fans arranged for the same heat exchanger.

[0002]

2. Description of the Related Art As a control device for controlling two electric fans used in a cooling device, two fan motors are switched between a series connection and a parallel connection, and a plurality of resistors are connected in series to the motor for resistance. There are those that switch values and those that PWM control a semiconductor switching element to chop the current to the motor to control the conduction ratio.

[0003]

However, in the case where the motor is switched between series and parallel, only two-step control can be performed, so if the control is performed according to the temperature or pressure of the medium in the heat exchanger, the frequency of parallel operation is high. As a result, noise is generated because the motor rotates at a high speed. Also, in the case where resistors are connected in series, the resistors generate heat and the power loss increases, so an expensive resistor with a large power capacity must be used, and a large space is required for heat dissipation and other measures. Become. Furthermore, in order to control a plurality of motors with a common semiconductor switching element, a large-capacity semiconductor switching element is required, which causes a problem that the cost is high. In driving, there is a problem that the power loss specific to the semiconductor element increases correspondingly.

The present invention is relatively inexpensive and enables multistage control,
Moreover, it is an object of the present invention to provide a drive control device with less power loss.

[0005]

According to a first aspect of the present invention, two fans arranged for the same heat exchanger are driven by a first motor and a second motor, respectively, and cooled by blowing air. In a drive control device for a cooling device, a semiconductor switching element connected in series to a power source and the first motor, and an electromagnetic relay having a series contact position connected in series to the power source and the second motor, The control circuit unit includes a detection unit that detects the temperature or pressure of the medium in the heat exchanger, and a control circuit unit that controls the operation of the semiconductor switching element and the electromagnetic relay based on the detection value of the detection unit. Drives the first motor by changing the conduction ratio of the semiconductor switching element according to the temperature or pressure of the medium, and the temperature or pressure of the medium. Is greater than or equal to a predetermined value, the electromagnetic relay is switched to the series connection position, the second motor is connected to the power source via the electromagnetic relay, and the total air volume of the two fans is adjusted to the medium temperature or pressure. The technical means is to increase as the price rises.

According to the second aspect of the present invention, in the drive control device of the cooling device, the two fans arranged for the same heat exchanger are driven and cooled by the first motor and the second motor respectively, and the power supply is provided in the drive control device. And a semiconductor switching element connected in series with the first motor, a first contact position for connecting the second motor between the power supply and ground, and the second motor in parallel with the first motor. An electromagnetic relay having a second contact position connected to the heat exchanger, detection means for detecting the temperature or pressure of the medium in the heat exchanger, and operation of the semiconductor switching element and the electromagnetic relay based on the detection value of the detection means. And a control circuit unit that controls the conduction ratio of the semiconductor switching element according to the temperature or pressure of the medium, When the body temperature or pressure is lower than a predetermined value, the electromagnetic relay is switched to the second contact position, the second motor is connected in parallel with the first motor, and the temperature or pressure of the medium is a predetermined value. In the above case, the electromagnetic relay is switched to the first contact position, the second motor is connected between the power source and the ground, and the total air volume of the two fans is increased according to the increase in the medium temperature or the pressure. Increasing the amount is a technical means.

In the invention of claim 1 or 2, the control circuit section renders the semiconductor switching element non-conductive when the temperature or pressure of the medium is not more than a first value smaller than the predetermined value, When the second value is equal to or higher than the first value and is equal to or lower than a second value which is higher than the predetermined value, the semiconductor switching element is driven at a constant low conduction ratio. It is good to have continuity.

Alternatively, the control circuit unit makes the semiconductor switching element non-conductive when the temperature or pressure of the medium is a first value smaller than the predetermined value, and is equal to or more than the first value and the predetermined value. In the following cases, the conduction ratio of the semiconductor switching element is gradually increased to a predetermined conduction rate, and when the second value is not less than the predetermined value and is larger than the predetermined value, the conduction ratio of the semiconductor switching element is It is preferable that the semiconductor switching element is made to be fully conductive when it is lower than a predetermined conduction rate and then gradually increased, and when it is the second value or more.

According to a fifth aspect of the present invention, in the drive control device of the cooling device, the two fans arranged for the same heat exchanger are driven and cooled by the first motor and the second motor, respectively, and the power supply is used. A semiconductor switching element serially connected to the first motor, a first contact position for connecting the second motor between the power supply and ground, and the second motor in series with the first motor. And an electromagnetic relay having a second contact position for connecting both motors between the power source and ground, a detection means for detecting the temperature or pressure of the medium in the heat exchanger, and a detection value of the detection means. And a control circuit section for controlling the operation of the semiconductor switching element and the electromagnetic relay based on the above, the control circuit section, when the temperature or pressure of the medium is a predetermined value or less, the electromagnetic relay When the second contact position is set and the semiconductor switching element is made non-conductive, and when the temperature or pressure of the medium is a predetermined value or more, the electromagnetic relay is switched to the first contact position and the conduction ratio of the semiconductor switching element is set. The technical means is to change the temperature in accordance with the temperature or pressure of the medium.

According to a fifth aspect of the present invention, the control circuit section is configured such that, when the temperature or pressure of the medium is equal to or lower than a first value lower than the predetermined value, the first motor and the second motor.
A second electromagnetic relay for cutting off the power supply to the motor may be provided.

Further, in the invention according to claim 5 or 6, the semiconductor device according to the fifth or sixth aspect of the present invention is configured such that, when the temperature or pressure of the medium is equal to or higher than the predetermined value and equal to or lower than a second value which is higher than the predetermined value. It is preferable that the switching element be driven at a constant low conduction ratio, and the semiconductor switching element be fully conducted when the second value or more is reached.

[0012]

According to the first aspect of the invention, as the temperature or pressure of the medium of the heat exchanger rises, the conduction ratio of the semiconductor switching element increases, and the drive ratio of the first motor increases. The amount of air blown by the fan driven by the motor is increased. Also, when the temperature or pressure of the medium rises or becomes higher than a predetermined value, the electromagnetic relay switches to the series connection position and the second motor is connected to the power source and driven, so that it is driven by the second motor. Air is blown by the fan, and at this time, the second motor rotates at the maximum rotation speed to generate the maximum air volume. Therefore, the amount of air blown by the first motor gradually increases until the temperature or pressure of the medium reaches a predetermined value, and the air blow by the second motor is started at a predetermined value. In addition to the maximum air volume of the fan driven by, the air blown by the first motor becomes larger according to the temperature or pressure of the medium.

According to the second aspect of the present invention, when the temperature or pressure of the medium is equal to or lower than a predetermined value, the conduction ratio of the medium is changed by the semiconductor switching element while the first motor and the second motor are connected in parallel. Since the two fans change depending on the temperature or the pressure, the two fans both blow air according to the temperature or the pressure of the medium. When the value exceeds a predetermined value, the first motor remains connected to the semiconductor switching element in series, and only the second motor is connected to the power source in series by the electromagnetic relay. Therefore, the maximum air volume by the fan driven by the second motor is reached. And the air volume according to the temperature or pressure of the medium of the fan driven by the first motor is summed to deliver the air volume.

According to the third aspect of the present invention, when the temperature or pressure of the medium is equal to or lower than the first value which is smaller than the predetermined value, neither of the two fans blows air. At this time, the fan driven by the first motor blows air at a constant air volume. At this time, if the fan has a predetermined value or more, the fan driven by the second motor blows air at the same time.

In the invention of claim 4, below the first value,
The two fans are not driven together, and until the predetermined value is reached, the two fans blow with the same air volume that gradually increases according to the temperature or pressure of the medium.
The fan driven by the motor blows the maximum amount of air,
At this time, the conduction ratio of the semiconductor switching element is once reduced so that the sum of the air volumes of the first motor and the air volume of the two fans immediately before reaching the predetermined value does not significantly differ. . If the value is above a certain value, the second
In addition to the maximum air volume of the fan driven by the motor of
The air volume of the fan driven by the first motor is gradually increased according to the temperature or pressure of the medium, and when the second value or more, the fan of the first motor blows at the maximum air volume.

In the invention of claim 5, when the temperature or pressure of the medium is equal to or lower than a predetermined value, the voltage of the power source is applied to the two motors connected in series. Since each fan is driven by the voltage, each fan blows air with a capacity that is half the maximum blowing capacity.
When the value is equal to or more than the predetermined value, the second motor is directly connected to the power source, and therefore the fan driven by this motor blows air with the maximum blowing capacity. Further, since the first motor is driven at the conduction ratio according to the temperature or pressure of the medium, the fan driven by this motor blows air at a blowing amount according to the temperature or pressure of the medium. Therefore, the sum of the blowing capacities of the two fans is variable according to the temperature or pressure of the medium, and multistage or stepless blowing control can be performed.

According to the sixth aspect of the invention, when the temperature of the medium is low or the pressure is low, the air blowing is stopped.

According to the seventh aspect of the present invention, it is possible to perform air blowing control in three steps, and when the temperature of the medium is high or the pressure is high, the air can be blown with the maximum air blowing capacity of the two fans.

[0019]

According to the present invention, in the air blowing control using two fans, multi-step or stepless air blowing control can be performed according to the temperature or pressure of the medium. In that case, one motor is energized by an electromagnetic relay and the other motor is energized by full conduction of the semiconductor switching element in order to obtain the maximum air volume, so that the semiconductor switching element can be energized by one motor as much as possible. Since it suffices to have the above capacity, a low capacity can be used, and the cost can be suppressed.

[0020]

Next, the present invention will be described based on embodiments. FIG. 1 shows a schematic configuration of a first embodiment and a second embodiment of a vehicle cooling device 10 in which a drive control device for a cooling device of the present invention is applied to a vehicle. In FIG. 1, reference numeral 1 is a radiator for radiating cooling water in a water jacket of an engine in a vehicle, and 2 is a condenser for radiating heat of a vapor phase refrigerant in a refrigeration cycle mounted in the vehicle to a liquid refrigerant ( Condensers), and two electric fans 1 driven by motors 11 and 12, respectively, for blowing and cooling the radiator 1 and the condenser 2 which are arranged in series.
1A and 12A are juxtaposed in front of the radiator 1.

In the vehicle cooling device 10, each motor 1
MOSF is used as the current-carrying member for driving
An ET 7 and an electromagnetic relay 8 are provided, and each motor 11, 1
One terminal 2 is connected to the positive electrode of the battery 6 via the contact 4 of the main relay and the fuse 5 which are closed when the ignition switch 3 is turned on, and the other terminal of the motor 11 is provided as a semiconductor switching element. The drain 7a of the MOSFET 7 is connected, and the other terminal of the motor 12 is connected to the movable contact a of the electromagnetic relay 8. The break contact 8b of the electromagnetic relay 8 is M
When the electromagnetic relay 8 is not driven when it is connected to the drain 7a of the OSFET 7, the motor 12 is
1 is connected in parallel. The make contact 8c of the electromagnetic relay 8 is connected to the negative electrode of the battery 6 together with the source 7b of the MOSFET 7, and when the electromagnetic relay 8 is driven, the motor 12 is directly connected to the battery 6.

The MOSFET 7 and the electromagnetic relay 8 described above are controlled by the control circuit section including the input determination circuit 20 and the output control circuit 40.

The input determination circuit 20 includes a water temperature sensor 13 including a thermistor for detecting the temperature of the cooling water in the radiator 1, and a refrigerant temperature sensor for detecting the temperature of the refrigerant in the condenser 2 which also includes the thermistor. And a blower request signal V1 based on the temperature detected by the water temperature sensor 13, a blower request signal V2 based on the temperature detected by the refrigerant temperature sensor 14, and an air conditioner switch 15 for operating the air conditioner device in the refrigeration cycle. The output control circuit 40 selects the blast request signal Vn having the largest blast request from among the blast request signals V3 based on the generated signal.
Transmit to

The output control circuit 40, in response to the air blowing request signal Vn transmitted from the input determination circuit 20, the MOSFET.
7 and the electromagnetic relay 8 are controlled respectively to perform multi-step control or stepless control of the sum of the air blow rates of the electric fans 11A and 12A. Note that 11B is a commutation diode.

Next, based on FIG. 2, the vehicle cooling system 1
A first example of No. 0 will be described. The input determination circuit 20 converts the detection signal of the water temperature sensor 13 into a voltage proportional to the water temperature to obtain the air blowing request signal V1, and the detection signal of the refrigerant temperature sensor 14 into a voltage proportional to the refrigerant temperature. A differential amplifier circuit 22 for converting the air supply request signal V2 into a blower request signal V2;
The air blowing request signals V1 to V3 of these respective circuits are sent to the analog OR circuit 24, respectively. Analog or circuit 2
4, the highest voltage of the air blowing request signals V1 to V3 of the differential amplifier circuits 21 and 22 and the reference voltage generating circuit 23 is output as the air blowing request signal Vn of the input determination circuit 20.

The reference voltage generating circuit 23 is provided between the positive electrode and the negative electrode of the battery 6 via the transistor 23a provided for switching to apply the voltage of the battery 6 when the air conditioner switch 15 is turned on. This is a circuit for generating the reference voltage for rotating the motors 11, 12 at least at low speed by the output control circuit 40 by the voltage dividing circuit by the resistors 25, 26 as the air blowing request signal V3, and when the air conditioner switch 15 is turned on. , The NPN type transistor 23b provided in the preceding stage of the transistor 23a is turned on, which turns on the PNP type transistor 23a, and the battery 6 is connected to the voltage dividing circuit.
Since the voltage is applied, the air blowing request signal V3 is generated.

In order to eliminate the influence of the refrigerant temperature, the differential amplifier circuit 22 for generating a signal voltage according to the refrigerant temperature turns on the transistor 27 when the air conditioner switch 15 is off to perform the differential amplification. The output stop circuit 28 for switching the output voltage of the circuit 22 to low is provided, and when the air conditioner is not operating, the electric fan 11A, 12A is activated by the air blowing request signal V2 based on the detection signal of the refrigerant temperature sensor 14. I'm trying to stay out of control.

Therefore, when the air conditioner switch 15 is off, the output of the differential amplifier circuit 22 is switched to low by the output stop circuit 28 regardless of the temperature of the refrigerant, and
Since the reference voltage is not generated in the reference voltage generation circuit 23, the analog OR circuit 24 outputs the blowing request signal V1 of the differential amplifier circuit 21 that outputs a voltage according to the temperature detected by the water temperature sensor 13 to the input determination circuit 20. As the output voltage Vn,
It is sent to the output control circuit 40.

On the contrary, when the air conditioner switch 15 is turned on, the output stop circuit 28 does not operate and the reference voltage generating circuit 23 generates the reference voltage. Therefore, the analog OR circuit 2
4 is a differential amplifier circuit 21, 22, a reference voltage generation circuit 23
Of the blow request signals V1 to V3, the highest voltage is selected and sent to the output control circuit 40 as the output voltage Vn of the input determination circuit 20.

The output control circuit 40, based on the air blowing request signal Vn output from the input determination circuit 20, outputs the MOSFE signal.
The T11 and the electromagnetic relay 8 are drive-controlled to drive the motor 11,
A drive control device for controlling the blowing amount of the electric fans 11A, 12A driven by 12 in three stages,
It has a low speed comparison circuit 41, a middle speed comparison circuit 42, and a high speed comparison circuit 43 for performing three-stage air volume control according to the air blowing request signal Vn of the input determination circuit 20. Each comparison circuit 4
1 to 43, the determination voltage circuits 41a, 42a,
43a is provided, and in each of the comparison circuits 41 to 43, the air blowing request signal Vn of the input determination circuit 20 is the low speed determination voltage Va and the medium speed determination voltage V of the determination voltage circuits 41a to 43a.
b, a high level is output when each is higher than the high-speed determination voltage Vc, and a low level is output when each is less than each determination voltage Va to Vc. Here, the determination voltages Va of the determination voltage circuits 41a to 43a,
Vb and the determination voltage Vc have a relationship of Va <Vb <Vc.

In the output control circuit 40, a transistor 44 is provided for driving the coil 8A of the electromagnetic relay 8 in accordance with the output of the medium speed comparison circuit 42, and the MO transistor MO is also provided.
A transistor 45 for inverting a signal to the gate of the MOSFET 7 for controlling the SFET 7, a PWM control comparison circuit 46 for controlling the transistor 45 according to the output of the low speed comparison circuit 41, and a transistor 4
And a transistor 47 for controlling 5 according to the output of the high speed comparison circuit 43.

The PWM control comparison circuit 46 includes a transistor 48 when the low speed comparison circuit 41 outputs a high level.
Is turned on to generate a constant voltage by the voltage dividing circuit of the resistors 48a and 48b.
And a triangular wave generating circuit 46b for generating a triangular wave, and the voltage of the voltage generating circuit 46a and the triangular wave generating circuit 46b.
Of the low speed comparison circuit 41
Of the specified duty ratio when the output of
A pulse signal for WM control is generated to generate the transistor 45.
For switching control.

When the output of the low-speed comparison circuit 41 is low and the transistor 48 is off, the battery 6
Is input to the PWM control comparison circuit 46 via the resistor 48a as the output voltage of the voltage generation circuit 46a, and this voltage is always higher than the triangular wave voltage input from the triangle wave generation circuit 46b to the PWM control comparison circuit 46. Since it is set to be high, the PWM control comparison circuit 46 outputs a high level. Therefore, the transistor 45 is turned on and the MOSFET 7 is turned off.

On the other hand, the transistor 47 does not act on the transistor 45 because it turns off when the high-speed comparison circuit 43 outputs a low level, and the high-speed comparison circuit 4
When 3 outputs a high level, it turns on, so P
By fixing the output of the WM control comparison circuit 46 to a low level and turning off the transistor 45, the MOSFET 7 is forcibly driven to the ON state regardless of the output of the PWM control comparison circuit 46.

Next, the output control circuit 4 having the above configuration
The operation of 0 will be described with reference to FIG. When the air conditioner switch 15 is off, the water temperature of the radiator 1 is low,
The blow request signal Vn of the input determination circuit 20 is equal to the determination voltage Va.
If it is lower, all the comparison circuits 41 to 43 are at the low level, so that the transistor 48 is turned off.
The output of the PWM control comparison circuit 46 becomes high level,
At this time, the transistor 47 is turned off by the output of the high-speed comparison circuit 43, so that the transistor 45 is turned on. Therefore, the MOSFET 7 does not turn on. At this time, the output of the medium speed comparison circuit 42 causes the transistor 44
Is turned off and the coil 8A of the electromagnetic relay 8 is not energized, so that the motor 12 is connected in parallel with the motor 11. Therefore, both the motor 11 and the motor 12 are MOSFs.
It is not energized because it is not driven by ET7. As a result, neither of the electric fans 11A and 12A operates.

When the air blowing request signal Vn is higher than the judgment voltage Va and lower than the judgment voltage Vb, the low speed comparison circuit 41 is used.
Only becomes high level, and the PWM control comparison circuit 46 outputs a pulse signal for PWM control with a predetermined duty ratio, so that the transistor 45 is switched at a predetermined duty ratio, and as a result, the PWM control comparison circuit 46.
MOSFET with the duty ratio that the pulse signal of
7 is switched. Therefore, the motors 11 and 12 are energized and driven by the MOSFET 7 at a low duty ratio,
Both the electric fans 11A and 12A operate at low speed rotation, and the sum of the blown air amounts becomes a small air amount.

When the air blowing request signal Vn is higher than the judgment voltage Vb and lower than the judgment voltage Vc, the low speed comparison circuit 41 is used.
In addition to the output of, the output of the medium speed comparison circuit 42 becomes a high level, the transistor 44 controlled by the medium speed comparison circuit 42 is turned on, and the coil 8A is energized. The movable contact 8a is connected to the make contact 8c. As a result, the motor 11 remains energized and driven by the MOSFET 7 at a low duty, and only the motor 12 is directly connected to the battery 6. Therefore, since the electric fan 11A rotates at a low speed and the electric fan 12A rotates at a high speed, the sum of the blown air amounts of the two fans 11A and 12A becomes the medium air amount.

When the air blowing request signal Vn is higher than the judgment voltage Vc, all the comparison circuits 41 to 43 are at the high level, so that the transistor 47 controlled by the high speed comparison circuit 43 is turned on. Since the transistor 45 is turned off, the MOSFET 7 is not controlled by the pulse signal of the PWM control comparison circuit 46 and is continuously turned on, so that the motor 11 is continuously energized. As a result, the electric fan 11A rotates at a high speed and the electric fan 12A rotates at a high speed, so that the two fans 11
The sum of the air flow rates of A and 12A is the large air flow rate.

Next, a second embodiment of the present invention will be described with reference to FIG. In the second embodiment, instead of the output control circuit 40 of the first embodiment in which the control state of the air flow rate is set to three stages, an output control circuit 40A for performing stepless control in which the air flow rate is continuously changed is used. There is. Hereinafter, the output control circuit 40A
The configuration of will be described. In FIG. 4, the same reference numerals as those in FIGS. 1 and 2 indicate the same or the same functions.

In the second embodiment, a differential amplifier circuit 41A is used in place of the low speed comparison circuit 41 and the transistor 48 which compare the blow request signal Vn with the judgment voltage Va and output only the judgment result in the first embodiment. And analog OR circuit 41B
And a blow request signal Vn is connected to one input terminal of the analog OR circuit 41B via the resistor 41C, and the other input terminal is input to the analog OR circuit 41B via the resistor 41C. The output of the differential amplifier circuit 41A is connected to the air blowing request signal Vn1 that reduces the air blowing request signal Vn at a predetermined ratio and outputs a signal as the air blowing request signal Vn2.

The input terminal to which the resistor 41C is connected has a medium speed comparison circuit 4 for controlling the electromagnetic relay 8 at its input terminal.
The collector of a switching transistor 41D controlled by the output of 2 is connected. This allows
When the blow request signal Vn is lower than the determination voltage Vb in the medium speed comparison circuit 42 and the transistor 41D is off,
When the voltage of the air blowing request signal Vn input to the analog OR circuit 41B via the resistor 41C becomes high, the air blowing request signal Vn is higher than the determination voltage Vb, and the transistor 41D is on, the differential amplifier circuit 41A is used. As a result, the voltage of the air blowing request signal Vn input to the analog OR circuit 41B increases.

The PWM control comparison circuit 46 compares the higher one of the two signals obtained from the air blowing request signal Vn obtained by the analog OR circuit 41B with the voltage of the triangular wave generation circuit 46b, and compares the higher one. Circuit 41
When there is a portion where the air blowing request signal Vn from B becomes higher than the output of the triangular wave generating circuit 46b, the triangular wave generating circuit 46b.
A pulse signal having a duty ratio in which the output is at a high level only while the output is higher than the output is generated as a signal for PWM controlling the motors 11 and 12. Further, on the output side of the PWM control comparison circuit 46, in order to match the ON state of the PWM control comparison circuit 46 and switch the MOSFET 7 to the ON state, a switching circuit formed by a transistor 46A is provided between the transistor 45 and the transistor 45. There are steps.

Next, the operation of the output control circuit 40A of the second embodiment having the above construction will be described with reference to FIG. When the blow request signal Vn input to the analog OR circuit 41B via the resistor 41C is lower than the output of the triangular wave generation circuit 46b and the pulse signal for PWM control does not occur, the output of the comparison circuit 46 for PWM control Becomes low level, the MOSFET 7 is not turned on and the motors 11 and 12 are not energized. Therefore, the electric fans 11A and 12A do not blow air.

Analog OR circuit 4 via resistor 41C
The air blowing request signal Vn input to 1B becomes high, and the PWM
When a pulse signal for PWM control is generated by the control comparison circuit 46, the MOSFET 7 is turned on with a duty ratio corresponding to the pulse signal. The duty ratio at which the MOSFET 7 is turned on becomes higher as the blow request signal Vn becomes higher while the blow request signal Vn is lower than the determination voltage Vb. At this time, the coil 8A of the electromagnetic relay 8
Is not energized, both motors 11 and 12 are MOS
The PWM control by the FET 7 energizes according to the air blowing request signal Vn. Therefore, the electric fans 11A and 12A
Are controlled to rotate at a medium speed or lower in accordance with the air blowing request signal Vn, and the sum of the air blowing amounts becomes equal to or lower than the medium air amount.

When the air blow request signal Vn becomes equal to or higher than the judgment voltage Vb, the transistor 41D is turned on. Therefore, in the PWM control comparison circuit 46, instead of the air blow request signal Vn1 transmitted via the resistor 41C, differential amplification is performed. P based on the ventilation request signal Vn2 whose voltage is reduced by the circuit 41A
A pulse signal for WM control is generated. Therefore, when the air blowing request signal Vn becomes the determination voltage Vb, the duty ratio of the pulse signal of the PWM control comparison circuit 46 temporarily decreases,
The duty ratio increases again as the air blowing request signal Vn becomes higher than the determination voltage Vb. At this time, since the coil 8A of the electromagnetic relay 8 is energized and the movable contact 8a is connected to the make contact 8c, the motor 12 is directly connected to the battery 6. Therefore, the electric fan 11A is
It is controlled to rotate at a medium speed or lower according to the air blowing request signal Vn,
On the other hand, since the electric fan 12A is controlled to rotate at high speed,
The sum of the air flow rates is the air volume around the medium air volume around the medium air volume.

When the air blowing request signal Vn becomes equal to or higher than the judgment voltage Vc, the transistor 47 is turned on, the transistor 45 is turned off, and the MOSFET 7 is always turned on regardless of the output of the PWM control comparison circuit 46. Therefore, since the motor 11 is continuously energized, the electric fan 1
1A is controlled to a high speed rotation. At this time, the electric fan 12
Is controlled to rotate at a high speed, the sum of the air blowing amounts becomes a large air amount.

6 and 7 show a third embodiment of the present invention.
In each drawing, the same reference numerals are given to the same or functional objects in the above-described embodiments. In the vehicle cooling device 100 of the third embodiment, the battery 6 to each motor 11,
An electromagnetic relay 9 for interrupting current is provided in the power supply circuit to 12.

First, the energizing circuit for the motors 11 and 12 will be described. The motor 11 has one terminal 11 a connected to the positive electrode of the battery 6 via the contact 9 a of the electromagnetic relay 9 and the fuse 5 a, and the other terminal 11 b.
Is connected to the break contact 8b of the electromagnetic relay 8. The motor 12 has one terminal connected to the movable contact 8 a of the electromagnetic relay 8 and the other terminal connected to the negative electrode of the battery 6. In the make contact 8c of the electromagnetic relay 8,
A fuse 5b, which is branched and connected, is connected to a connection point between the contact 9a and the fuse 5a. The terminal 11b of the motor 11 connected to the break contact 8b is connected to the MOSFET 7
Is also connected to the drain 7a of the
The anode of the commutation diode 16 is connected to a, and the cathode of the diode 16 and the terminal 11 of the motor 11 are connected.
A noise filter 17 is connected between a and a.

One of the coils 8 A of the electromagnetic relay 8 is connected to the collector of a PNP type transistor 51 which supplies the power of the battery 6 via the ignition switch 3, and the other is connected to the negative electrode of the battery 6. Similarly, one of the coils 9A of the electromagnetic relay 9 supplies the power of the battery 6 via the ignition switch 3 to the PN.
It is connected to the collector of the P-type transistor 52, and the other is connected to the negative electrode of the battery 6.

The above energizing circuit is the control circuit 5 shown in FIG.
Controlled by 0. The control circuit 50 includes a pressure sensor 53 that detects the pressure of the refrigerant in the refrigeration cycle, instead of the refrigerant temperature sensor that detects the temperature of the refrigerant. Further, in order to control at least a small amount of air when the air conditioner is operating, a signal from a contact 19 of a relay for energizing a coil 18 of a magnet clutch for transmitting engine rotation to a refrigerant compressor in a refrigeration cycle is used. doing. Here, when the contact 19 is closed and the voltage of the battery 6 is applied via the connector K, the NPN type transistor 54 is turned on, whereby the transistor 52 for energizing the electromagnetic relay 9 is connected. Force on via L.

The control circuit 50 is provided with a differential amplifier circuit 22a for obtaining a blow request signal V2 corresponding to the pressure detected by the pressure sensor 53 and an output of the differential amplifier circuit 22a when the air conditioner is not operating. Transistors 55 and 56 for setting the low level are provided, and the analog OR circuit 24 causes the differential amplification circuit 2 to respond to the blower request signal V1 of the differential amplification circuit 21 according to the water temperature of the radiator 1 and the pressure of the refrigerant.
A signal having a higher voltage is selected as the ventilation request signal Vn from the ventilation request signal V2 of 2a and transmitted to the low speed comparison circuit 41, the medium speed comparison circuit 42, and the high speed comparison circuit 43.

The low speed comparison circuit 41 outputs the air blowing request signal Vn.
Is higher than the determination voltage Va, the transistor 57 is turned on to energize the electromagnetic relay 9.
2 is forced on via connector L. When the blow request signal Vn is higher than the determination voltage Vb, the medium speed comparison circuit 42 turns on the transistor 58 and connects the transistor 51 for energizing the coil A of the electromagnetic relay 8 to the connector M.
The electromagnetic relay 8 is driven by being turned on via the, and the motor 12 is directly connected to the battery 6. Also,
The medium speed comparison circuit 42 includes a voltage dividing circuit that divides the output by the resistors 59 and 60, and inputs the divided voltage to the PWM control comparison circuit 46.

The PWM control comparison circuit 46 outputs a predetermined duty ratio (50) according to the divided voltage when the middle speed comparison circuit 42 is at a high level and the output of the triangular wave generation circuit 46b.
%) Pulse signal to generate transistors 61, 45
As a PWM control signal having a duty ratio matched with the pulse signal of the PWM control comparison circuit 46,
It is used as a switching signal of the MOSFET 7 via the connector N. The high-speed comparison circuit 43 turns off the transistor 45 by turning on the transistor 47 when the air blowing request signal Vn is higher than the determination voltage Vc, and turns on the connector N.
Is fixed to a high level, and the MOSFET 7 is forcibly turned on regardless of the output of the PWM control comparison circuit 46.

Next, the operation of the control circuit 50 of the third embodiment having the above construction will be described with reference to FIG. When the air conditioner is not in operation, the transistor 56 is turned on and the output of the differential amplifier circuit 22a becomes low level. Therefore, the differential amplifier circuit 21 outputs the blower request signal V1 according to the water temperature of the radiator 1. The air flow rate is controlled.
When the air conditioner is operating, the transistor 54 is turned on, at least the electromagnetic relay 9 is driven, and a voltage half the voltage of the battery 6 is applied to each of the motors 11 and 12, so that each fan is driven. Each of 11A and 12A blows air with a half blowing capacity, and the sum of the blown air amounts becomes 50% of the maximum blown air amount.

When the air blowing request signal Vn is equal to or higher than the judgment voltage Va and lower than the judgment voltage Vb, the MOSFET 7 is not driven. Similarly, the sum of the air blowing amounts is 5 which is the maximum air blowing amount.
It will be 0%. The ventilation request signal Vn is the judgment voltage V
When it is equal to or more than b and is lower than the determination voltage Vc, the transistor 58 and the transistor 51 are turned on and the electromagnetic relay 8 is driven, so that the motor 12 rotates at a high speed and the motor 11
Is subjected to PWM control by the MOSFET 7 at a duty ratio of 50%, so that the medium speed rotation is performed. As a result,
The sum of the air blowing amounts by the electric fan 11A and the electric fan 12A is 75% of the maximum air blowing amount. When the air blowing request signal Vn is equal to or higher than the determination voltage Vc, the transistor 47 is turned on while the electromagnetic relay 8 is driven, so that the MOSFET 7 is continuously turned on.
The motor 11 is continuously energized. Therefore, each electric fan 1
Both 1A and 12A rotate at high speed to obtain the maximum air flow rate.

As described above, according to the above embodiments,
Since the connection between the two motors is switched by using the electromagnetic relay and the MOSFET, it is possible to perform three-step or stepless blow control. When each motor is rotated at high speed, the electromagnetic relay and the MOSFET are individually energized. When controlling the motor by switching the MOSFET, a resistor is used to operate the motor at a low duty. Since there is little power loss and heat generation as in the case of being used, a MOSFET with a small capacitance can be used, and the cost can be suppressed. In addition, in the third embodiment, the MOSFET
When the switch is operated, only one motor is energized, so that the capacity of the noise filter for preventing noise can be reduced and the cost can be suppressed.

[Brief description of the drawings]

FIG. 1 is a circuit diagram showing a schematic circuit configuration of a first embodiment and a second embodiment of the present invention.

FIG. 2 is a circuit diagram showing an output control circuit according to a first embodiment of the present invention.

FIG. 3 is an explanatory diagram for explaining the operation of the first embodiment of the present invention.

FIG. 4 is a circuit diagram showing an output control circuit according to a second embodiment of the present invention.

FIG. 5 is an explanatory diagram for explaining the operation of the second embodiment of the present invention.

FIG. 6 is a circuit diagram showing a schematic circuit configuration of a third embodiment of the present invention.

FIG. 7 is a circuit diagram showing a control circuit according to a third embodiment of the present invention.

FIG. 8 is an explanatory diagram for explaining the operation of the third embodiment of the present invention.

[Explanation of symbols]

 1 Radiator (heat exchanger) 2 Condenser (heat exchanger) 11A, 12A Fan (two fans) 11, 12 Motor 6 Battery (power supply) 7 MOSFET (semiconductor switching element) 8 Electromagnetic relay 13 Water temperature sensor (detection means) 14 Refrigerant temperature sensor (detection means) 20 Input determination circuit (control circuit section) 40 Output control circuit (control circuit section)

Claims (7)

(57) [Claims] 1. A drive control device for a cooling device, wherein two fans arranged for the same heat exchanger are respectively driven by a first motor and a second motor to cool by blowing air. A semiconductor switching element connected in series with the motor, an electromagnetic relay having a series contact position connected in series with the second motor with respect to the power source, and detection for detecting the temperature or pressure of the medium in the heat exchanger. Means, and a control circuit section for controlling the operation of the semiconductor switching element and the electromagnetic relay based on the detection value of the detecting means, wherein the control circuit section is the semiconductor switching element according to the temperature or pressure of the medium. The first motor is driven by changing the conduction ratio of the electromagnetic relay and the electromagnetic relay is activated when the temperature or pressure of the medium is equal to or higher than a predetermined value. Via said electromagnetic relay is switched to column connection position the second
Is connected to the power source, and the total air volume of the two fans is increased according to the increase of the medium temperature or pressure. 2. A drive control device for a cooling device, wherein two fans arranged for the same heat exchanger are respectively driven by a first motor and a second motor to cool by blowing air. A semiconductor switching element connected in series with the motor, a first contact position for connecting the second motor between the power source and ground, and a second connection for connecting the second motor in parallel with the first motor. An electromagnetic relay having a contact position of, a detection means for detecting the temperature or pressure of the medium in the heat exchanger, and a control circuit for controlling the operation of the semiconductor switching element and the electromagnetic relay based on the detection value of the detection means. And a control circuit section that changes the conduction ratio of the semiconductor switching element according to the temperature or pressure of the medium, and the temperature of the medium or When the force is equal to or lower than a predetermined value, the electromagnetic relay is switched to the second contact position, the second motor is connected in parallel with the first motor, and the temperature or pressure of the medium is equal to or higher than a predetermined value, Switching the electromagnetic relay to the first contact position, connecting the second motor between the power source and the ground, and increasing the total air volume of the two fans in response to an increase in the medium temperature or pressure. A drive control device for a cooling device. 3. The control circuit section renders the semiconductor switching element non-conductive when the temperature or pressure of the medium is equal to or lower than a first value smaller than the predetermined value, and is equal to or higher than the first value and equal to the predetermined value. When it is less than the second value that is greater than the value,
3. The semiconductor switching device is driven at a constant low conduction ratio, and when the second value or more is reached, the semiconductor switching device is fully conducted.
The drive control device for the cooling device according to. 4. The control circuit unit renders the semiconductor switching element non-conductive when the temperature or pressure of the medium is a first value smaller than the predetermined value, and is not less than the first value and the predetermined value. When the following, gradually increase the conduction ratio of the semiconductor switching element to a predetermined conduction ratio,
When the second value is equal to or higher than the predetermined value and is equal to or lower than a second value that is higher than the predetermined value, the conduction ratio of the semiconductor switching element is decreased from the predetermined conduction ratio and then gradually increased. The drive control device for the cooling device according to claim 1 or 2, wherein the semiconductor switching element is fully conductive. 5. A drive control device for a cooling device, wherein two fans arranged for the same heat exchanger are respectively driven by a first motor and a second motor to cool by blowing air. A semiconductor switching element connected in series with the motor of No. 1, a first contact position for connecting the second motor between the power supply and ground, and a second switching motor connected in series with the first motor. An electromagnetic relay having a second contact position for connecting a motor between the power source and the ground, a detection means for detecting the temperature or pressure of the medium in the heat exchanger, and the semiconductor based on the detection value of the detection means. A control circuit unit for controlling the operation of the switching element and the electromagnetic relay, wherein the control circuit unit sets the electromagnetic relay to the second contact position when the temperature or pressure of the medium is equal to or lower than a predetermined value. In addition, the semiconductor switching element is made non-conductive, and when the temperature or pressure of the medium is a predetermined value or more, the electromagnetic relay is switched to the first contact position and the conduction ratio of the semiconductor switching element is set to the medium temperature or A drive control device for a cooling device, which is changed according to pressure. 6. The second control circuit cuts off the power supply to the first motor and the second motor when the temperature or pressure of the medium is equal to or lower than a first value lower than the predetermined value. The drive control device for the cooling device according to claim 5, further comprising an electromagnetic relay. 7. The control circuit unit drives the semiconductor switching element at a constant low conduction ratio when the temperature or pressure of the medium is equal to or higher than the predetermined value and equal to or lower than a second value higher than the predetermined value. The drive control device for the cooling device according to claim 5 or 6, wherein when the second value or more, the semiconductor switching element is fully conductive.