JPS5916965B2 - Air blow control device for automotive air conditioners - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to an improvement in an air blow control device for an automobile air conditioner in which an electric fan is used to cool a radiator and a condenser of an automobile air conditioner. be.

Conventional configuration and its problems In conventional air conditioners that use a radiator electric fan (hereinafter referred to as electric fan) to cool the radiator as well as the refrigerant condenser (hereinafter referred to as condenser), the electric fan is not used in the air conditioner. In some cases, when the water temperature of the radiator rises, it turns on, and when it falls, it turns off.

When the air conditioner is used next time, the ON-OFF operation is repeated in synchronization with the operation of the refrigerant compressor of the air conditioner.

Next, a conventional example will be explained based on FIG. 2 of the accompanying drawings.

That is, in the figure, 1a is a battery, 2a is a key switch, 3a is a fuse box, 4a is a cooler switch, and 5a is a cooler relay, which has a coil 7a and a movable contact 6a.

8a is an indoor fan, 9a is an electromagnetic clutch, 10a is a first
This is a radiator electric fan relay, which has a coil 12a and a movable contact 11a, and 13a is a radiator thermostat,
A second radiator electric fan relay 14a includes a movable contact 15a and a coil 16a.

20a indicates the minus side of batch 'J 1 a.

In this configuration, when the key switch 2a is turned on, the engine (not shown) enters the operating state.

Then, the radiator cooling water temperature is set to a predetermined value (for example, 85°C).
), the radiator thermostat 13a is turned ON, the movable contact 11a is energized by the coil 12a, and the electric fan 1γa is rotated while being directly connected to the power source (strong).

Further, when the radiator water temperature falls, the radiator thermostat 13a is turned off, the movable contact 11a is also opened, and the electric fan 17a is stopped.

Next, when the cooler switch 4a is turned on, the coil 7a is energized, the movable contact 6a is turned on, the indoor fan 8a is turned on, the electromagnetic clutch 9a is also turned on, and the refrigerant compressor (not shown) is also turned on. It rotates and starts cooling.

At the same time, the coil 16a of the relay 14a is also energized, and the movable contact 15a also causes the ONL electric fan 17a to rotate.

In such a conventional example, the electric fan 17a continues to rotate as usual with the direct connection of strong wind even in the early morning, at night, or on cloudy or rainy days when the cooling load is small.

In addition, even when there is no cooling load all day, such as in spring or autumn, strong winds can cause the air conditioner to rotate in the same way as described above.

That is, the electric fan 17a is turned on and off by the radiator thermostat 13a, and is also repeatedly stopped by turning the compressor on and off.

In other words, the electric fan 17a is the radiator thermostat 1
3a will also turn ON, and even if synchronized with the compressor, it will turn ON.
Since the electric fan 17a operates in N mode, when the air conditioner is used, the electric fan 17a
The operating time becomes very long.

This is undesirable because it shortens the life of the fan motor.

As is well known, if the electric fan 17a is inoperable due to the end of its service life, the water temperature in the radiator will rise, which will cause a serious problem such as engine heat, which will make the vehicle unable to run.

Therefore, it goes without saying that it is preferable that the life of the electric fan 17a is as long as possible.

Furthermore, the longer the electric fan operates, the more power it consumes, which reduces the amount of electricity stored in the battery, leading to a problem called a dead battery.

Conventionally, the latter drawback has been addressed by increasing the amount of power generated by enlarging the generator and increasing its capacity, or by replacing the V-belt pulley of the generator with a smaller diameter one to increase the rotation speed. Measures have been taken to extend the life of the generator, and in order to extend the life of the generator, due to the increasing quality and quantity of official materials, luxurious measures have been taken to ensure that the generator capacity is sufficient for the load.

Such an increase in rotational speed shortens the lifespan, and material input increases costs.

Purpose of the Invention The present invention aims to improve the above-mentioned conventional problems, and aims to protect the engine and improve air conditioning efficiency by changing the speed of the electric fan in accordance with the load on the condenser. shall be.

Composition of the Invention In order to achieve the above object, the air blow control device of the present invention includes a temperature detection section that operates when the radiator temperature of the engine reaches a predetermined temperature, and a temperature detection section that operates when the automobile air conditioner is operated. a detection section, a control device that operates upon receiving a signal from at least one of the temperature detection section or the operation detection section, and the operation of this control device cools a radiator and a condenser constituting the automobile air conditioner. The air blower is equipped with a capacity control device that detects the pressure in the refrigeration cycle of the automobile air conditioner in the operation detection section and controls the air blowing capacity of the blower.

DESCRIPTION OF THE EMBODIMENTS The present invention will be described below with reference to FIG. 1 of the accompanying drawings showing one embodiment thereof.

In the figure, 1 is a battery, 2 is a key switch, 3 is a fuse box, 4 is a cooler switch, 5 is a cooler relay, 6 is a movable contact, γ is a coil, 8 is an indoor fan, and 9 is an electromagnetic clutch. Controls power transmission between the engine and the compressor (not shown) of the automobile cooler.

10 is a first relay of the radiator electric fan 17, 11 is a movable contact, 12 is a relay coil, 13 is a radiator thermostat, 14 is a second relay of the radiator electric fan 17, 15 is a movable contact, and 16 is a coil.

Reference numeral 18 denotes a pressure switch, which sets the pressure of the condenser constituting the automobile cooler to a predetermined value (for example, 12 kg/c).
The structure is such that it turns on when the voltage exceeds IIlG).

19 is a resistor, which is typically made of nichrome wire.

In the above configuration, when the key switch 2 is turned on, the engine (not shown) is started and the water temperature in the radiator also rises.

Here, the water temperature of the radiator is set to a predetermined value (e.g. 85°C).
, the radiator thermostat 13 turns ON, and the relay coil 12 is energized to turn the movable contact 11 OFF.
Even in the N operation, the radiator electric fan 17 rotates.

Next, when the water temperature drops, the radiator thermostat 13 is turned off again, and the rotation of the radiator electric fan 17 is stopped.

Thereafter, the radiator electric fan 17 repeatedly starts and stops as described above due to the rise and fall of the water temperature in the radiator.

Let's consider the case where a cooler is used.

First, when the air conditioner switch 4 is turned on when the cooling load is large, such as in the middle of the day in midsummer, if the contact 11 of the first relay 10 is in the ON state, there will be no change in the rotation of the radiator electric fan 17. It is already rotating.

Also, when the radiator thermostat 13 is in the OFF state, the first
When the relay 10 is in the OFF operation, the movable contact 15 is first turned ON by the energization of the coil 16 of the second relay 14, and the radiator electric fan 17 is rotated via the resistor 19.

At this time, the fan 17 is weak and rotates at a low speed.

After a while, the condenser pressure rose and the pressure cass inch 18
For example, the set value is 12kg/Cl71. When the pressure exceeds G, the pressure switch 18 turns ON and the radiator electric fan 1
The power supply voltage is directly applied to the motor 7 without going through the resistor 19, and the motor rotates at high speed so as to operate in a strong wind.

When the capacitor pressure again drops to a low value, the pressure switch 18 is turned off and the radiator electric fan 17 returns to low speed rotation via the resistor 19.

Here, in addition to early mornings, nights, cloudy days, and both days when the cooling load is low, and in the intermediate period before and after the cooler season, the condenser pressure does not increase and often shows, for example, 8 to 10 kg/=G.

In other words, at such a low cooling load ζ, only a small amount of air is blown to the condenser, and there is no need to operate the radiator electric fan 17 in direct connection with strong wind. energizes the radiator electric fan 17, causing the radiator electric fan 17 to rotate at a low wind speed.

In this state, if the water temperature of the radiator exceeds a predetermined value, the radiator thermostat 13 is turned ON, the circuit of the first relay 10 is closed, and the radiator electric fan 17 is directly connected to the power supply via the movable contact 11. Return to strong wind and high speed rotation.

Therefore, when either the condenser or the radiator reaches a predetermined load or higher, the radiator electric fan 17 enters normal high-speed operation, thereby preventing an abnormal pressure rise in the condenser and overheating the engine.

Note that when the water temperature in the radiator is low, the cabin temperature due to the cooler has sufficiently decreased, and the electromagnetic clutch circuit is turned off by the room temperature thermostat (not shown), the first relay 10 and the second relay 14 of the radiator electric fan 17 are activated. Since both are OFF operations, the radiator electric fan 17 is stopped.

Therefore, various drawbacks of conventional automobiles that employ a condenser cooling method using the radiator electric fan 17, such as the short life of the motor of the radiator electric fan 17 and over-discharge of the battery due to high power consumption, are greatly improved. This makes it possible to provide more stable quality as an automobile, and in addition, since the electric fan 17 of the radiator does not always rotate at high speed when the cooler is in use, a quiet operation effect can be obtained.

Effects of the Invention As is clear from the above embodiments, the air blow control device for an automobile air conditioner according to the present invention includes a temperature detection section that operates when the radiator temperature of the engine reaches a predetermined temperature, and a temperature detecting section that operates when the radiator temperature of the engine reaches a predetermined temperature. an operation detection unit that operates when the temperature is exceeded; a control device that operates upon receiving a signal from at least either the temperature detection unit or the operation detection unit; and the operation of the control device configures the radiator and the automotive air conditioner. An air conditioner for an automobile, comprising: an air blower that cools a condenser; and a capacity control device that detects pressure during a refrigeration cycle of the air conditioner in the operation detection section to control the air blowing capacity of the air blower. is driven,
When the pressure in the refrigeration cycle is normal, the radiator and condenser are cooled by low-speed air blowing, which prevents the engine from overheating due to the operation of the automobile air conditioner.
At the same time, the cooling capacity is increased.

Furthermore, the blower rotates at high speed only when the temperature of the radiator that cools the engine exceeds the set value, or when the pressure during the refrigeration cycle of the automobile air conditioner rises above the set value. Since the blower rotates at high speed only in limited times, it is possible to control the high speed rotation time of the blower to the minimum necessary, suppress over-discharge of the battery as much as possible, and extend the life of the blower.
This has various advantages, such as increasing the life span of the electrical system.

[Brief explanation of drawings]

FIG. 1 is a schematic electrical circuit diagram of an automobile air conditioner equipped with an air blow control device according to an embodiment of the present invention, and FIG. 2 is a schematic electrical circuit diagram of a conventional automobile air conditioner. 4...Cooler switch (operation detection part), 10
... 1st relay (control device), 13...
・Radiator thermostat (temperature detection part), 14...
... Second relay (control device), 18 ... Pressure switch, 19 ... Resistor (capacity control device).

Claims (1)

[Claims] 1. A temperature detection section that operates when the radiator temperature of the engine reaches a predetermined temperature, an operation detection section that operates before the automobile air conditioner is operated, and a condenser that constitutes the radiator and automobile air conditioner. A blower that performs cooling, a rotation speed control device that controls the rotation speed of this blower,
a first relay that rotates the blower at high speed by the operation of the temperature detection section; a second relay that operates a rotation speed control device so that the blower is slowed down by the operation of the operation detection section; An air blow control device for an automobile air conditioner comprising a pressure switch that detects pressure in a refrigeration cycle and operates a rotation speed control device so that the blower speeds up when the pressure rises to a set value.