JPH08260965A - Engine cooling device - Google Patents

Abstract

PURPOSE: To cope with a state of emergency that it exceeds the cooling capacity of a cooling device by applying voltage more than a rated voltage of an electric motor to the electric motor for driving a fan in rotation in the case where the temperature of engine cooling water detected by a water temperature detecting means is above a designated value. CONSTITUTION: Fans 5a, 5b for cooling a radiator 6 and a capacitor 7 are driven in rotation by electric motors 4a, 5b, and the application of an electric current to the electric motors 4a, 4b from an alternator 1 or a battery 2 is controlled through a control circuit 3. At this time, the control circuit is provided with an engine cooling water temperature sensor 8a and a pressure switch 8b for detecting the high tension side pressure of a coolant of a refrigerating cycle and decides the voltage applied to the electric motors 4a, 4b according to the engine cooling water temperature. When the engine cooling water temperature is above a designated value, the voltage more than the rated voltages of the electric motors 4a, 4b is applied to the motors to increase the rotating speed of the fans 5a, 5b and increase the air quantity.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an engine cooling device for cooling engine cooling water.

[0002]

2. Description of the Related Art Conventionally, as a method of cooling engine cooling water, the engine cooling water is circulated through a radiator and the engine cooling water is cooled by blowing air from an electric blower.
The specifications of these radiators and blowers are the most severe conditions (outside air temperature,
It is set with a margin so that the engine does not overheat due to running load, etc., so measures are taken to increase the size of the radiator or the electric blower.

[0003]

However, in recent years,
As the engine output increases, the running state of the vehicle (for example,
Depending on the case where the engine is always operated near the red zone in the summer, the engine cooling water may reach a higher temperature, which may cause an emergency in which the cooling capacity of the cooling device is exceeded.

In view of the above problems, the present invention has been made in view of the above problems.
An object of the present invention is to provide an engine cooling device that can cope with an emergency situation in which the cooling capacity of the cooling device is exceeded.

[0005]

In order to solve the above problems, the present invention provides a radiator for cooling engine cooling water by exchanging heat between engine cooling water and cooling air. Water temperature detecting means for detecting the temperature of engine cooling water, a fan for blowing cooling air toward the radiator,
An electric motor for rotationally driving the fan is provided, and when the temperature of the engine cooling water detected by the water temperature detecting means becomes equal to or higher than a predetermined value, the electric motor is applied with a voltage equal to or higher than a rated voltage of the electric motor. Engine cooling system.

[0006]

According to the configuration of the invention described above, according to the invention of claim 1, when the temperature of the engine cooling water detected by the water temperature detecting means exceeds a predetermined value, the motor is rated. By applying a voltage higher than the voltage, the rotation speed of the fan increases and the air flow improves.
The temperature of the engine cooling water can be forcibly reduced.

As a result, it is possible to avoid an emergency in which the engine cooling water becomes excessively high in temperature (predetermined temperature).

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to FIGS.
It will be described based on. FIG. 2 shows an overall configuration diagram of a cooling system for cooling the engine cooling water. These cooling systems are arranged in the engine room of the vehicle, and are provided with a radiator 6 which is a radiator for cooling an engine (not shown) that generates a driving force for driving the vehicle.

The radiator 6 cools engine cooling water circulating in a water jacket which is a water flow passage formed in the engine. Specifically, the radiator 6 is provided between stacked tubes (not shown) and between the tubes. And fin means for increasing heat exchange efficiency. Then, the engine cooling water flows in the tube, and the outer peripheral surface of the tube and the air blown to the outer periphery of the tube by a fan described later exchange heat with each other, whereby the engine cooling water is cooled.

Further, the circulation cycle of the engine cooling water is a well-known one in which a water pump, a water jacket, a radiator, and a water pump are circulated in this order. On the upstream side in the direction of air flow passing through the radiator 6, a condenser, specifically a condenser 7, which is one component of the refrigeration cycle of the vehicle, is installed.

In this refrigeration cycle, the refrigerant is sucked in, compressed,
It has components such as a refrigerant compressor (not shown) for discharging, a condenser 7 for condensing and liquefying the refrigerant, a decompression expansion means (not shown) for decompressing and expanding the liquefied refrigerant, and an evaporator for evaporating the refrigerant decompressed and expanded. It is well known. Two fans 5a and 5b are arranged on the air downstream side of the radiator 6 and the condenser 7. The fans 5a and 5b are rotationally driven by fan driving means, specifically, electric motors 4a and 4b, generate a blowing capacity according to the number of revolutions, and allow cooling air to pass through the radiator 6 and the condenser 7. Cooling. The electric motor 4
The electric motor of the present invention is formed by a and 4b.

The electric motors 5a and 5b are generators using the driving force of the engine as a drive source, specifically the voltage generated by the alternator 1, or a charger mounted on the vehicle, specifically the battery 2. The voltage is supplied from the control circuit 3, and this voltage is controlled by the control circuit 3 according to the states of the radiator 6 and the capacitor 7. The control circuit 3 determines the voltage applied to the electric motors 4a and 4b. As input information, the control circuit 3 detects the temperature of the engine cooling water and constitutes the water temperature detecting means of the present invention. The voltage is determined based on the output value of the pressure switch 8b that detects the high pressure side pressure of the refrigerant in the refrigeration cycle.

The specific operation of the control circuit 3 will be described below with reference to FIGS. 1 and 5. FIG. 3 shows the relationship between the output value of the engine cooling water temperature sensor 8a and the voltage applied to the electric motors 4a and 4b. FIG. 4 shows the relationship between the output value of the pressure switch 8b and the voltage applied to the electric motors 4a and 4b. In this embodiment, the electric motors 4a and 4b are
When any one of the conditions is satisfied as shown in FIG. 3 or FIG. 4, the control circuit 3 applies a voltage to apply a voltage equal to or higher than Lo and Hi and the rated voltage as in the conventional case.

As shown in FIGS. 3 and 4, the temperature and the pressure of the engine cooling water change rapidly depending on the use condition, the environmental condition of the outside air and the running condition, and accordingly, the blowing ability of the fans 5a and 5b. Variably controlled.
It should be noted that the engine cooling water has a good temperature determined according to the engine, and is 80 degrees to 90 degrees in the present embodiment.

Next, the specific operation of the fans 5a and 5b will be described with reference to FIG. 1 and Table 1.

[0016]

[Table 1] First, when the compressor is off, that is, when the refrigerant is not compressed, the normal refrigerant pressure is P2 (note that
This refrigerant pressure P1 is set by the capacity of the condenser 7, but is smaller than, for example, 15.5 kg / cm ^2, and it is not necessary to blow air to the condenser 7.

The voltage applied to the electric motors 4a and 4b is determined according to the temperature of the engine cooling water. Explaining in the order shown in Table 1, the vehicle ignition is ON.
After that, it is assumed that the temperature of the engine cooling water gradually rises and reaches t1 (for example, 90 degrees). In this case, since it is necessary to cool the engine cooling water, the engine cooling water is applied to the electric motors 4a and 4b so that the rotation speed becomes Hi.

Then, the engine cooling water further rises,
If it becomes t2 (for example, when the engine is continuously rotated at a high rotation speed), the engine cooling water must be further cooled, so that a voltage higher than the rated voltage is applied to the electric motors 4a and 4b. Where the electric motor 4
The rated voltage of a and 4b is 12V, which is the same as the rated voltage of the battery 2.

Further, here, the temperature t2 of the engine cooling water is
The upper limit of the temperature of the engine cooling water is generally determined according to the vehicle, so if this upper limit is 108 degrees, t2 should be set to 1 with a margin.
Set it to 05 degrees. That is, the engine cooling water is 105
In the above case, the engine may overheat, so it is necessary to immediately cool the engine cooling water.

Then, a voltage higher than the rated voltage is applied to the electric motors 4a, 4b.
For example, the voltage of the electric motors 4a and 4b, that is, the speeds of the fans 5a and 5b are increased and the temperature of the engine cooling water is decreased by forcibly increasing the voltage to 15 V by means of a transformer or the like. On the other hand, in the process in which the temperature of the engine cooling water gradually decreases from this state, there is a hysteresis and finally t3 (for example, 83 degrees).
At, the voltage applied to the electric motors 4a and 4b becomes zero.

Next, the case where the compressor is ON will be described. When the compressor is ON, the refrigerant pressure varies depending on the required refrigerating capacity of the refrigeration cycle. First, a case where the temperature of the engine cooling water is lower than t3 will be described. Basically, when the engine cooling water is t3, it is not necessary to blow air to the radiator 6, but since the refrigerant circulates in the refrigeration cycle although it is minute, it is necessary to condense the refrigerant with the condenser 7. Therefore, the electric motor 4
A voltage is applied to a and 4b so that the rotation becomes Lo.

When the refrigerant pressure becomes higher than P1, a larger amount of heat of condensation is required, and therefore a voltage is applied to the electric motors 4a and 4b so that the rotation thereof becomes Hi. Next, when the temperature of the engine cooling water becomes higher than t1, it is determined that the heat load of the engine has increased irrespective of the refrigerant pressure, and a voltage is applied to the electric motors 4a and 4b so that the rotation speed becomes Hi. Is applied.

When the temperature of the engine cooling water further rises to t2, as described above, the electric motor 4a,
A voltage higher than the rated voltage is applied to 4b to suppress the temperature rise of the engine cooling water. In this way, before the temperature of the engine cooling water reaches the predetermined upper limit value, the electric motor 4a,
By increasing the voltage applied to 4b to the rated voltage or higher, the temperature of the engine cooling water can be forcibly lowered, and the heat load on the engine can be reduced in an emergency.

Since a voltage higher than the rated voltage is applied to the electric motors 4a, 4b, it is considered that the durability is adversely affected, but it is very unlikely that an emergency will occur throughout the year. It is considered that there is no problem in durability of the electric motors 4a and 4b. In addition, the electric motor 4a,
If there is no problem in the durability of 4b, the following effects can be obtained by using such an idea.

As described above, the radiator 6 and the electric motors 4a and 4b have been improved with the recent improvement of the engine output.
However, there is a problem in that the mountability on a vehicle deteriorates. However, the electric motor 4
Since the cooling capacity of the engine cooling water is improved by increasing the rotational speeds of a and 4b, the cooling capacity can be secured without increasing the size of the radiator 6 or the electric motors 4a and 4b, and the mountability on the vehicle is improved. Can be made.

[Brief description of drawings]

FIG. 1 is a diagram showing an operation of a cooling device according to a first embodiment of the present invention.

FIG. 2 is a schematic configuration diagram of a cooling system in the first embodiment.

FIG. 3 is a diagram showing a relationship between a temperature of engine cooling water and a voltage applied to an electric motor.

FIG. 4 is a diagram showing a relationship between a refrigerant pressure and a voltage applied to an electric motor.

[Explanation of symbols]

 6 radiator (radiator) 4a electric motor (electric motor) 4b electric motor (electric motor) 5a fan 5b fan 8a engine cooling water temperature sensor 8b pressure switch

Claims (1)

[Claims] 1. A radiator for cooling the engine cooling water by exchanging heat between the engine cooling water and the cooling air, water temperature detecting means for detecting the temperature of the engine cooling water, and cooling air for the radiator. A fan that blows air and an electric motor that drives the fan to rotate are provided. When the temperature of the engine cooling water detected by the water temperature detecting means reaches or exceeds a predetermined value, the electric motor is applied with a voltage equal to or higher than the rated voltage of the electric motor. An engine cooling device characterized by the above.