JPS6032006B2 - Engine cooling fan device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a fan device for cooling a radiator incorporated in the cooling system of an automobile engine, etc., and more particularly relates to an electric cooling fan device in which a cooling fan is rotationally driven by an electric motor. related to a fan device.

A radiator cooling fan incorporated into an engine cooling system such as an automobile engine is generally configured to be driven to rotate directly by the engine, but in recent years, such a cooling fan has been driven to rotate by an electric motor. A so-called electric type has been developed.

In such an electric cooling fan, when the engine cooling water temperature has not reached a predetermined temperature and the engine is cold, the power to the electric motor is immediately stopped if the engine cooling water is not circulating in the radiator. By stopping the rotation of the cooling fan, engine horsepower loss can be reduced compared to a fan that is directly rotationally driven by the engine, and the cooling fan can be rotated in the desired control manner regardless of the engine speed. Since it can be driven, it has the advantage of avoiding overheating even in city driving where idling, low speed driving, and driving at medium and high distances are repeated. By the way, even with such an electric cooling fan, when the engine operation is stopped, the power to the electric motor is simultaneously stopped, the rotation of the cooling fan is stopped, and forced cooling of the engine is stopped. When the engine is stopped after severe driving such as driving or climbing a long slope, the heat of the overheated engine causes the fuel pump and carburetor to reach high temperatures, causing the gasoline in the float chamber and fuel passage of the carburetor to become hot. If the temperature becomes extremely high, the gasoline may evaporate abnormally, causing percolation, which may make it impossible to restart the engine.

When such a percolation phenomenon occurs, even if the engine does not become impossible to restart, a large amount of HC is emitted when the engine is restarted, and evaporation emissions increase.Especially as exhaust gas regulations become stricter these days, countermeasures are becoming more and more difficult. The need is growing stronger. Furthermore, recently, the temperature in the engine room tends to increase due to the installation of exhaust gas purification devices, which makes it easier for the percolation phenomenon to occur in the carburetor. SUMMARY OF THE INVENTION An object of the present invention is to provide an engine cooling fan device that can effectively avoid the percolation phenomenon of the carburetor as described above using an existing cooling fan.

According to the present invention, this object includes a cooling fan, an electric motor that rotationally drives the cooling fan, a battery that supplies current to the electric motor, and an electric motor that electrically connects the electric motor and the battery. an electric circuit including two first and second branch paths branched in parallel to each other, an ignition switch and a first branch path connected in series to each other in the middle of the first branch path; The first temperature-sensitive switch includes a temperature-sensitive switch, a timer switch, a second temperature-sensitive switch, and a resistor that are connected in series to each other in the middle of the first branching path, and the first temperature-sensitive switch is configured to control the temperature of the engine coolant. The second overflow switch opens when the acid level is below a predetermined value and closes when the acid level is above a predetermined value. closes for a predetermined period of time from the moment it is opened,
The resistor has a fan rotation speed when the cooling fan is operated through the first branch path compared to a fan circuit speed when the cooling fan is operated through the first branch path. This is achieved by an engine cooling fan device characterized by having a resistance value that substantially reduces the resistance value.

According to this configuration, when the engine is operated with the ignition switch closed, the cooling fan is rotated to perform normal engine cooling when the engine coolant temperature is higher than a predetermined value, and the ignition switch is opened. Even after the engine is stopped, if the representative temperature of the carburetor at that time is higher than a predetermined value, the cooling fan continues to rotate and blows outside air to the carburetor in the engine room, so that the temperature of the carburetor is As a result, the temperature of the fuel (gasoline) present in the float chamber and fuel passage of the carburetor is prevented from increasing, and the occurrence of percolation phenomenon is avoided.

The fuel temperature in the float chamber is the best representative temperature for the above-mentioned carburetor, but it may also be the engine temperature, engine room temperature, or engine cooling water temperature. Further, a timer switch that closes only for a predetermined period of time after the ignition switch is opened may be connected in series with the temperature-sensitive switch. In this case, after the ignition switch is opened and the engine is stopped, if the temperature representing the carburetor at that time is higher than a predetermined value, the cooling fan continues to operate for a predetermined time after the ignition switch is opened. This prevents the power of the battery power source from being wasted unnecessarily. Further, according to the detailed features of the present invention, the number of times after the engine is stopped, that is, the number of revolutions of the motor, is made smaller within an allowable range than that during engine operation, and the power consumption of the power source is reduced. It may be configured to be as small as possible.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to the accompanying drawings. FIG. 1 attached herewith is a diagram showing an electric circuit of a motor of an engine cooling fan device according to the present invention.

In the figure, 1 is a cooling fan located behind the radiator, which is not shown in the figure.
is adapted to be rotationally driven by a DC motor 2. The DC motor 2 is composed of a series motor in which an armature A and a field coil F are connected in series.
Current is selectively supplied from a DC power source 3 such as a battery through each switch described below.
That is, there is a water temperature switch SW, which is connected in series to the engine ignition switch 4, in the middle of the electric circuit that electrically connects the electric motor 2 and the DC power supply 3, and this water temperature switch SW is connected to the engine cooling water. It is configured to open when the temperature is below a predetermined value and close when the temperature is above a predetermined value.

Further, in the middle of the electric circuit, a timer switch SW2 and a temperature sensing switch SW3, which are connected in series with each other, are connected in parallel to the ignition switch 4 and the water temperature switch SW. The timer switch SW2 is configured to close for a predetermined period of time, for example, several minutes after being opened by the ignition switch 4, and to open after the elapse of a predetermined period of time. The temperature-sensitive switch SW3 senses a temperature representative of the carburetor temperature, for example, the temperature of engine cooling water or the vicinity of the carburetor, and closes when the temperature is above a predetermined value and opens when the temperature is below a predetermined value. It is configured. The opening/closing water temperature of the water temperature switch SW is determined by the cooling performance of the engine as before, and the opening/closing temperature of the temperature sensitive switch SW3 is determined as appropriate depending on the amount of fuel percolation while the engine is stopped, restartability, capacity of the battery power source, etc. It can be decided. Further, in this embodiment, a series resistor R is connected in series to the timer switch SW2 and the temperature-sensitive switch SW3, and in parallel to the ignition switch 4 and the water temperature switch SW.

During engine operation with the ignition switch 4 closed, if the water temperature switch SW detects a temperature higher than a predetermined value and is closed, the electric circuit including the DC power supply 3 and the DC motor 2 is turned off. The rated voltage of the DC power supply 3 is applied to the armature A and the field coil F of the DC motor 2. Therefore, at this time, the DC motor 2 has a predetermined rotation speed,
For example, it is rotated at about 2000 RPM, and the cooling fan is driven to rotate at that rotation speed. On the other hand, when the ignition switch 4 is opened to stop the engine operation, the timer switch SW2 is closed for a predetermined period of time.

At this time, if the temperature-sensitive switch SW3 detects a temperature higher than a predetermined temperature that may cause percolation, this temperature-sensitive switch SW3 is also closed, so that the armature A of the DC motor 2 and the field coil F has a series resistor R
A reduced voltage is now applied, and the DC motor 2 continues to rotate at a lower rotational speed than when the engine is operating. Therefore, the carburetor is submergedly cooled by the outside air sucked into the engine room by the cooling fan 1, which continues to rotate after the engine is stopped, thereby avoiding the occurrence of percolation. FIG. 2 is an electrical circuit diagram showing another embodiment of the engine cooling fan device according to the present invention.

In FIG. 2, parts corresponding to those in FIG. 1 are designated by the same reference numerals as those in FIG. In the case of this embodiment, a speed control resistor R' is connected in parallel to the field coil F of the electric motor 2, and in the middle of the electric circuit connecting the resistor R' and the field coil F in parallel. The timer switch S
The structure is substantially the same as that of the embodiment shown in FIG. 1, except that a switch SW〆 which opens and closes like W2 is provided. Therefore, in this case as well, if the temperature-sensitive switch SW3 detects a temperature higher than the predetermined value when the ignition switch is turned off, the DC motor 2 will continue to rotate at a lower rotation speed than when the engine is running, and the cooling fan will continue to rotate. drive the rotation. Although the present invention has been described above in detail only with respect to specific embodiments, it is understood that the present invention is not limited to these and that various modifications and embodiments can be made within the scope of the present invention. This will be obvious to businesses.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing an example of the electric circuit of the motor of the engine cooling fan according to the present invention, and FIG. 2 is another embodiment of the electric circuit of the motor of the engine cooling fan device according to the present invention. FIG. 1... Cooling fan, 2... DC motor, 3... DC power supply, 4... Ignition switch, A... Armature, F...
・Field coil, SW. ...Water temperature switch, SW2.
・・・． ...Timer switch, SW2'.... ...Switch, SW3...Temperature-sensitive switch, R...Series resistor, R'...Resistor. Figure 2 of the vines

Claims (1)

[Claims] 1. A cooling fan, an electric motor that rotationally drives the cooling fan, a battery that supplies current to the electric motor, and an electric circuit that electrically connects the electric motor and the battery, and has two parallel branches in the middle. an ignition switch and a first temperature-sensitive switch connected in series to each other in the middle of the first branch, and the second branch. A timer switch, a second temperature-sensitive switch, and a resistor are connected in series in the middle of the engine, and the first temperature-sensitive switch opens when the temperature of the engine coolant is below a predetermined value. The second temperature-sensitive switch opens when the temperature representing the vaporizer is below a predetermined value and closes when the temperature is above a predetermined value, and the timer switch closes for a predetermined time from the moment the ignition switch is opened. , the resistor has a fan rotation speed when the cooling fan is operated via the second branch path compared to a fan rotation speed when the cooling fan is operated via the first branch path. A cooling fan device for an engine, characterized in that it has a resistance value that substantially reduces the speed.