JPH0884471A - Cooling device for generator in automobile - Google Patents

Abstract

PURPOSE: To realize a cooling device for the generator in an automobile in which cooling air can be produced appropriately through simple constitution even under low speed operation. CONSTITUTION: The stator coil 9 of an alternator is connected with a plurality of rectifier diodes 121 constituting a full-wave rectifier circuit connected with a battery 20. The battery 20 has the plus side terminal connected through a field coil 6 with the collector of a transistor Tr1 and the GND terminal connected with the emitter of the transistor Tr1. A cooling motor 14 is connected in parallel with the field coil 6 and the conduction currents thereof vary similarly. Consequently, at the time of idling where the rotational speed of the engine is low, the rotational speed of the cooling motor 14 increases to feed a large quantity of cooling air and at the time of general traveling where the rotational speed of the engine is high, the rotational speed of the cooling motor 14 decreases to exhibit an appropriate cooling effect.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cooling device for an automobile generator, and more particularly to a cooling device for cooling a voltage regulator for adjusting a generated voltage of an automobile generator by a cooling electric motor.

[0002]

2. Description of the Related Art As a conventional cooling device for an automobile generator, there is, for example, a "rotor of an alternator for a vehicle" described in JP-A-5-236700. In this "rotor of an alternator for a vehicle", a fan is fixed to the rotor, and cooling air is generated by rotating the rotor to cool the generator.

However, in the above "rotor of an alternator for a vehicle", the cooling air generated depends on the rotational speed of the rotor, and the rotational speed of the rotor depends on the engine rotational speed. Depends on. Therefore, during low-speed running of the vehicle in which running wind cannot be expected, the rotation speed of the rotor is low and the amount of cooling air is insufficient, so that the generator cannot be cooled sufficiently.

Therefore, as a cooling device capable of obtaining a sufficient cooling air even when the vehicle is running at low speed, for example, Japanese Patent Laid-Open No. 3-270659 and Japanese Patent Laid-Open No. 5-219685.
Is disclosed in Japanese Patent Application Laid-Open Publication No. HEI 9-203 (1995).

In the cooling devices described in the above-mentioned Japanese Patent Laid-Open Nos. 3-270659 and 5-219685,
The vehicle AC generator is provided with a duct, and a hose for ventilation is attached to this duct. An electric fan is installed inside the duct, and when the temperature of the generator rises, such as when the vehicle runs at a low speed, the electric fan forces the cooling air into the generator to cool the generator. ing.

[0006]

However, in the cooling device described in JP-A-3-270659 or JP-A-5-219685, there is a temperature sensor for detecting the temperature of the rectifying device or the voltage adjusting device. The control device for controlling the operation of the electric fan based on the temperature detection signal from the temperature sensor is required separately. Therefore, the structure becomes complicated, which causes a cost increase.

An object of the present invention is to realize a cooling device for an automobile generator, which has a simple structure and can obtain an appropriate cooling air even when the vehicle is running at low speed.

[0008]

In order to achieve the above object, the present invention is configured as follows. In a cooling device for an automobile generator having an armature winding, a field winding, and a voltage control means for controlling a current flowing through the field winding and controlling a generated voltage, an electric motor having a cooling fan is provided. Prepare,
The drive power input terminal of this motor was connected in parallel to the field winding.

Further, in a cooling device for an automobile generator having an armature winding, a field winding, and a voltage control means for controlling a current flowing through the field winding and controlling a generated voltage, An electric motor having a fan was provided, and the drive power input terminal of this electric motor was connected in series to the field winding.

Further, in a cooling device for an automobile generator having an armature winding, a field winding, and a voltage control means for controlling a current flowing through the field winding and a generated voltage, One output terminal of the voltage generated by the child winding, one end of which is connected, and an open / close switch that can be opened / closed based on a command signal corresponding to the cooling water temperature of the radiator from the automobile engine control device, and a cooling switch The motor includes a fan, and an electric motor whose drive power input terminal is connected between the other end of the open / close switch and the other output terminal of the voltage generated by the armature winding. When the water temperature reaches or exceeds the predetermined temperature, it closes and the electric motor is driven.

Further, in a cooling device for an automobile generator, which has an armature winding, a field winding, and voltage control means for controlling a current flowing through the field winding and a generated voltage, One of the start command generation means that determines that the passing current command value to the field winding of the control means is equal to or greater than a predetermined value and outputs a fan start command signal, and the voltage generated by the armature winding. One end is connected to the output terminal of
An open / close switch that can be opened / closed based on a fan start command signal from the start command generation means, and a cooling fan, and is provided between the other end of the open / close switch and the other output terminal of the voltage generated by the armature winding. And an electric motor to which the drive power source input terminal is connected. The open / close switch is closed and the electric motor is driven when the current flowing through the field winding exceeds a predetermined current.

Further, in a cooling device for an automobile generator having an armature winding, a field winding, and a voltage control means for controlling a current flowing through the field winding and a generated voltage, It is arranged on a rotor that rotates in response to the rotation of the engine, and when the rotation speed of the engine becomes equal to or higher than a predetermined rotation speed, it is opened by centrifugal force and one end of the armature winding is connected to one terminal. An opening / closing switch, a cooling fan, and an electric motor whose driving power input terminal is connected between the other end of the opening / closing switch and the other terminal of the armature winding. When the rotation speed becomes lower than the predetermined rotation speed, the motor is closed and the electric motor is driven.

Further, preferably, in the above-described cooling device for an automobile generator, the opening / closing switch is closed when the engine rotation speed falls below a predetermined rotation speed from 500 to 2500 rotations per minute. Becomes

Further, preferably, in the above-described cooling device for an automobile generator, the electric motor is arranged close to the voltage control means, and cooling air from the electric motor is supplied to the voltage control means.

[0015]

The driving power input terminal of the electric motor having the cooling fan is connected to the field winding of the generator in parallel or in series.
The voltage control means adjusts the current flowing through the field winding in order to maintain the voltage generated by the generator at a substantially constant value. When the engine speed is high, the current flowing through the field winding is small, and when the engine speed is low, the current flowing through the field winding is large.

When the engine rotation speed is high, the current flowing through the field winding is small, the amount of heat generated is small, and the running wind of the vehicle can be expected. Therefore, the rotation speed of the electric motor having the cooling fan is high. You don't have to. On the other hand, when the engine speed is low, the current flowing through the field winding is large,
Since a large amount of heat is generated and the traveling wind of the vehicle cannot be expected so much, it is necessary to increase the rotation speed of the electric motor and generate a large amount of cooling wind.

Since the drive power input terminal of the electric motor is connected in parallel or in series with the field winding, the current flowing through the electric motor is substantially proportional to the current flowing through the field winding. As a result, when the engine speed is low, a large current is supplied to the electric motor and a large amount of cooling air is obtained by the cooling fan, and when the engine speed is high, a small current is supplied to the electric motor and the cooling fan is supplied. The cooling air is also small.

Since the automobile generator is arranged near the engine, the temperature of the generator is high when the engine cooling water temperature is high. Normally, the engine cooling water temperature is detected by the engine cooling water temperature sensor, and the detected temperature is
Supplied to the engine control unit. This is carried out to detect whether or not the cooling water temperature is abnormal. Therefore, when the cooling water temperature is equal to or higher than a predetermined temperature, the open / close switch is closed and the driving power is supplied to the cooling electric motor, thereby realizing a cooling device capable of performing an appropriate cooling operation with a simple configuration. it can.

Further, since the current flowing in the field current is controlled by the passing current command value from the voltage control means, it is judged by the start command generating means whether or not the passing current command value becomes equal to or more than a predetermined value. Then, the fan start command signal is output. Then, the opening / closing switch is closed by the fan start command signal, and the cooling electric motor is driven.

Further, an opening / closing switch which is opened by centrifugal force is arranged on the rotor which rotates in response to the rotation of the engine,
If the switch is configured to control the power supply to the cooling electric motor, the cooling electric motor can be driven when the engine speed becomes less than the predetermined rotational speed, and a proper cooling can be performed with a simple structure. It is possible to realize a cooling device that can execute operations.

[0021]

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a schematic circuit configuration diagram of a cooling device for an automobile generator that is a first embodiment of the present invention, and FIG. 6 is a schematic sectional view of an automobile generator (alternator).

First, in FIG. 6, a pulley 3 is arranged at one end of the shaft 1 and a slip ring 4 is arranged at the other end of the shaft 1. A rotor 7 is fixed to the shaft 1, and a field coil (field winding) 6 is arranged inside the rotor 7. The rotor 7 is rotatably supported inside the housing 11 via the bearing 2. The slip ring 4 is slidable with the brush 5 arranged in the housing 11, and electric power is supplied from the brush 5 to the field coil 6 via the slip ring 4.

A built-in fan 10 is attached to the rotor 7 on the pulley 3 side and the slip ring 4 side of the rotor 7, and the built-in fan 10 provides an air volume proportional to the rotation speed of the rotor 7. Further, a stator 8 is arranged on the inner wall of the housing 11 so as to face the rotor 7 with a slight gap therebetween, and a stator coil (armature winding) 9 is wound around the stator 8. There is.

Inside the housing 11, a voltage regulator (voltage control means, generally called an IC regulator) for adjusting the magnitude of the induced voltage generated in the stator coil 9 and induction of alternating current are provided. A control circuit 12 including a rectifying diode for rectifying the voltage is arranged. And
A radiation fin 13 is attached to the control circuit 12, and a cooling electric motor 14 having a cooling fan is arranged so that the radiation fin 13 can be forcibly cooled by air. A perspective view of the control circuit 12, the radiation fins 13, and the cooling electric motor 14 is shown in FIG.

The pulley 3 of the alternator shaft 1 is
It is connected to the pulley on the engine side via a belt,
The shaft 1 rotates in proportion to the engine rotation speed.
When the engine speed is the lowest, it is about 650 rpm when idling. The maximum rotation speed is 6 per minute
The rotation speed is about 500, which is about 10 times the minimum rotation speed, and the engine has a wide rotation speed range.

In such a wide rotation speed range, the power generation voltage of the alternator must be kept constant. In order to keep the output voltage of the alternator constant even if the rotation speed of the engine changes, it is necessary to control the current supplied to the field coil 6 wound around the rotor 7.

Since the magnitude of the induced voltage E _out of the alternator is expressed by the following equation (1), the frequency is low when the vehicle is running at a low speed, so that the energizing current to the field coil 6 is made large, and when running at a high speed. Since the frequency becomes high, it is necessary to control the electric current to the field coil 6 to be small. That is, it is necessary to control the product of the frequency f and the field current i to be constant. E _out = k × f × ns × i × n _R −−− (1) where k is a constant, f is a frequency, ns is the number of turns of the stator coil 9, i is a current flowing through the field coil 6, and n _R Is the number of turns of the field coil 6.

The magnitude of the induced voltage E _out can be adjusted by controlling the energizing current i of the field coil 6 from the above equation (1). However, considering cooling, the amount of wind generated by the built-in fan 10 is small because the rotation speed of the rotor 7 is low when the vehicle runs at a low speed. Further, in order to control the power generation voltage of the alternator to be constant, the frequency f
Is low, the energization current i must be large, the amount of heat generated by the field coil 6 is large, and this heat is trapped in the alternator. In addition, since running wind cannot be expected at low speeds, heat generated by the engine is also transmitted to the alternator, which causes a rise in temperature.

Next, considering the high speed running of the vehicle, the rotation speed of the rotor 7 becomes high and the internal fan 10
Since the amount of wind generated at 1 increases with the square of the speed, and the value of the current supplied to the field coil 6 is small, the amount of heat generated is small. In addition, the heat generated by the engine is also carried out of the engine room by the running wind. Therefore,
When the vehicle runs at high speed, there is no problem in cooling because the amount of heat generated is small and a large amount of cooling air can be taken.

In the alternator, the most severe point in heat resistance is the control circuit 12 composed of a semiconductor such as the IC regulator 122 and the rectifying diode 121 described above.
Part of. Further, as the temperature rises, the resistance value of the winding tends to rise and the copper loss tends to rise, so cooling of the coil is important. Therefore, as described above, it is important to cool the control circuit 12 including the field coil 6 of the rotor and the stator winding at low speed (when idling, etc.).

As described above, when the engine speed is low, the value of the current supplied to the field coil 6 is large, so that the cooling electric motor 14 has a large cooling effect.
A large amount of air is required. On the other hand, the engine speed is
When the speed becomes high, the value of the current supplied to the field coil 6 becomes small, and traveling wind can be expected. Therefore, the air volume of the cooling electric motor 14 does not need to be large.

FIG. 8 shows the magnitude of the current to the field coil 6 with respect to the current generated by the alternator. As shown in FIG. 8, in order to obtain the same generated current value, the energizing current to the field coil 6 must be larger when the engine speed is idling Ni than when the vehicle is running normally Nd. .

Since the magnitude of the current flowing to the field coil 6 is determined by the voltage applied to the field coil 6, the field coil voltage is proportional to the current flowing from a different viewpoint. The field coil voltage is inversely proportional to the engine speed. FIG. 9 is a graph showing the relationship between the cooling motor voltage and the generated current value,
The relationship is similar to the relationship between the field current and the generated current value shown in FIG.

Therefore, if attention is paid to this characteristic and the voltage applied to the cooling motor 14 is made to be the same as the field coil voltage, a large cooling motor voltage can be obtained when a large amount of cooling air is required. Therefore, when there is no need for a large amount of cooling air, a small cooling motor voltage can be obtained.

The first embodiment shown in FIG. 1 is an example using the principle described above. In FIG. 1, the drive power input terminal of the cooling electric motor 14 described above is connected in parallel to the field coil 6. The stator coil 9 of the alternator is connected to the connection points of the anodes and cathodes of the plurality of rectifying diodes 121, and these plurality of rectifying diodes 121 form a full-wave rectifying circuit.

The output terminal of the full-wave rectification circuit composed of a plurality of rectification diodes 121 is the battery 20 (about 12
V). The positive terminal of the battery 20 is connected to the IC regulator 12 via the field coil 6.
It is connected to the collector of the second transistor Tr1. Also,
The GND terminal of the battery 20 is connected to the emitter of the transistor Tr1. A cooling electric motor 14 is connected in parallel with the field coil 6.

As described above, since the cooling electric motor 14 is connected in parallel with the field coil 6, the energizing current of the cooling electric motor 14 changes similarly to the energizing current to the field coil 6. That is, as mentioned above,
A voltage having the characteristics shown in FIG. 9 is applied to the cooling electric motor 14, and when the engine rotational speed is low, the rotational speed of the cooling electric motor 14 is high, a large amount of cooling air is obtained, and the engine rotational speed is high. During traveling, the rotation speed of the cooling electric motor 14 becomes low, and an appropriate cooling effect can be obtained.

As described above, according to the first embodiment of the present invention, the electric motor 14 for cooling is connected in parallel with the field coil 6, and the current having the same change characteristic as the current supplied to the field coil 6 is generated. The electric motor 14 for cooling is energized.
Thus, when the engine rotation speed is low, the rotation speed of the cooling electric motor 14 is high, and a large amount of cooling air is obtained. When the engine rotation speed is high, the cooling electric motor 1 is provided.
The rotation speed of No. 4 is small, and an appropriate air volume is obtained. Therefore, it is possible to realize a cooling device for an automobile generator, which has a simple structure and is capable of obtaining an appropriate cooling air even when the vehicle is running at low speed. Further, when the engine rotation speed is high, the rotation speed of the cooling electric motor 14 becomes small, unnecessary cooling air is prevented from being generated, and labor can be saved.

FIG. 2 is a schematic circuit configuration diagram of a cooling device for an automobile generator, which is a second embodiment of the present invention. Components equivalent to those in FIG. 1 are designated by the same reference numerals. . The difference between the example of FIG. 1 and the example of FIG. 2 is that the field coil 6 and the drive power input terminal of the cooling motor 14 are connected in series. That is, the collector of the transistor Tr1 of the IC regulator 122 is connected to the plus terminal of the battery 20 via the field coil 6 and the cooling electric motor 14.

In the configuration of the example of FIG. 2, a current equivalent to the current flowing in the field coil 6 is the cooling motor 1.
It flows to 4. Therefore, also in the example of FIG. 2, the same effect as that of the example of FIG. 1 can be obtained.

FIG. 3 is a schematic circuit configuration diagram of a cooling device for an automobile generator according to a third embodiment of the present invention. Components equivalent to those in FIG. 1 are designated by the same reference numerals. . In the example of FIG. 3, the positive terminal of the battery 20, that is, the current generated by the stator coil 9 is rectified by the rectifying diode 121, and one output terminal is the switch 15 and the cooling motor 14. Via the GND terminal of the battery 20, that is, the current generated from the stator coil 9 is rectified by the rectifier diode 121 and connected to the other output terminal. The engine control unit (ECU) 22 is usually mounted on an automobile, and the battery 20 is used as its power source. Therefore, the engine control unit 22 is connected in parallel with the switch 15 and the cooling electric motor 14 which are connected in series, and electric power is supplied from the battery 20.

Further, usually, the engine control unit 22 is supplied with a cooling water temperature detection signal of the cooling water temperature sensor 18 of the radiator and monitors the cooling water temperature.
Therefore, the cooling status of the engine can be grasped. Since the alternator is directly connected to the engine or driven by a belt, the alternator temperature and the engine temperature have a close relationship. Therefore, when the temperature of the cooling water becomes equal to or higher than a predetermined temperature during idling or the like, the switch 15 is turned on by a command signal from the engine control unit 22, and the cooling electric motor 1
Power is supplied to 4 and cooling air is generated. Then, when the cooling water temperature becomes lower than the predetermined temperature, the switch 15 is turned off by the command signal from the engine control unit 22, and the rotation of the cooling electric motor 14 is stopped.

As described above, in the example of FIG.
Only by adding the switch 15, the cooling electric motor 14 can be operated properly. Therefore, also with the example of FIG. 3, the same effect as that of the example of FIG. 1 can be obtained.

FIG. 4 is a schematic circuit configuration diagram of a cooling device for an automobile generator according to a fourth embodiment of the present invention. Components equivalent to those in FIG. 1 are designated by the same reference numerals. . In FIG. 4, the positive terminal of the battery 20, that is, the current generated by the stator coil 9 is rectified by the rectifying diode 121, and one output terminal is output via the switch 16 and the cooling electric motor 14. Battery 14G
The ND terminal, that is, the current generated by the stator coil 9 is rectified by the rectifier diode 121 and connected to the other output terminal. The switch 16 is turned on and off by the fan start command Sf from the IC regulator 122.
Controlled by.

The IC regulator 122 controls the generated electric power from the engine rotation speed and the load condition. The IC regulator 122 calculates the engine rotation speed from the generated voltage of the one-phase stator coil 9, and the speed calculation unit 1221. Generated power control unit 1222 that obtains generated power based on the engine speed and load condition calculated by the speed calculation unit 1221
Further, based on the power generation command value from the generated power control unit 1222, the transistor Tr1 is turned on / off, that is, a conduction ratio control unit 1220 for controlling the conduction ratio is provided. The transistor Tr1 is on / off controlled by the on / off command value from the conduction ratio controller 1220, and the field coil 6 is controlled.
The energizing current is controlled.

Further, the IC regulator 122 determines, based on the command value from the generated power control unit 1222, that the load is large and the engine rotation speed is low, and the start command generating unit 1223 that outputs the fan start command signal Sf. Equipped with. When the load is equal to or higher than the predetermined value and the engine speed is equal to or lower than the predetermined value (for example, the engine speed corresponding to idling) by the fan start command signal Sf from the start command generation unit 1223, the switch 1
6 is turned on, and the cooling electric motor 14 is started.

As described above, in the example of FIG.
A switch 16 connected to the cooling motor 14 in series is added with a startup command generator 1223 to the regulator 122.
The cooling electric motor 14 can be operated properly by simply adding Therefore, also with the example of FIG. 4, the same effect as that of the example of FIG. 1 can be obtained.

In the example of FIG. 4, the cooling electric motor 1
Start 4 according to the engine speed and load condition, and 2
It is also possible to execute the air volume control in more than one stage. That is, for example, it is possible to configure the switch 16 with a transistor or the like and control the conduction ratio by the control command signal from the start command generation unit to control the current value flowing through the cooling electric motor 14. As a result, not only can the ON / OFF of the cooling electric motor 14 be controlled, but also the rotational speed of the cooling electric motor 14 can be finely controlled according to the engine rotational speed and the load condition.

Further, in the example of FIG. 4, the start command generating unit 1223 determines that the passing current command value to the field coil 6 is equal to or more than the predetermined current value, and at this time, the fan start command signal Sf is output. It is also possible to supply the open / close switch 16 to drive the electric motor 14.

FIG. 5 is a schematic circuit configuration diagram of a cooling device for an automobile generator according to a fifth embodiment of the present invention. Components equivalent to those in FIG. 1 are designated by the same reference numerals. . In the example of FIG. 5, two of the three-phase stator coils 9 are used.
The cooling electric motor 14 and the governor switch 17, which are connected in series, are connected between the coils for the phases.
The governor switch 17 is a switch that turns on and off depending on the magnitude of centrifugal force. The governor switch 17 is arranged on the rotor 7, and is turned on when the rotation speed of the rotor 7 is lower than the predetermined rotation speed (for example, the rotation speed of the rotor 7 corresponding to idling). The cooling electric motor 14 is in a starting state. Then, when the rotation speed of the rotor 7 becomes equal to or higher than a predetermined rotation speed (the engine rotation speed is about 2500 rotations per minute), the governor switch 17 is turned off by the centrifugal force, and the rotation of the cooling electric motor 14 is stopped.

As described above, in the example of FIG.
When the governor switch 17 is connected in series to the cooling electric motor 14 and the rotation speed of the rotor 7 decreases and reaches a rotation speed corresponding to idling, for example, the governor switch 1
7 is turned on and the cooling electric motor 14 is started. Thus, the cooling electric motor 14 can be properly operated only by connecting the governor switch 17 to the cooling electric motor 14 in series, and the example of FIG. 5 also achieves the same effect as the example of FIG. be able to. Although the cooling electric motor 14 and the governor switch 17 are connected to the stator coil 9 in the example of FIG. 5, they may be connected to the battery 20. Further, in the example of FIG. 5, the engine speed at which the governor switch 17 is turned off may be any speed of 500 to 2500 rpm.

Further, in the above-mentioned example, the present invention can be applied to the cooling electric motor 14 which is either a DC motor or an AC motor. However, when an AC motor is used and a DC power supply is supplied to this AC motor, an inverter is required to generate an AC current from the DC power supply, but most of the fan motors currently on the market use an inverter. Since it is a built-in AC motor (brushless motor), the AC motor can be easily applied as a cooling electric motor. If a DC motor is used and AC power is supplied to this DC motor,
It may be configured to include a rectifying means (rectifying diode) for rectifying the AC power supply to the DC power supply.

Further, in the above-mentioned example, the control circuit 12, the radiation fins 13 and the cooling electric motor 14 are arranged inside the housing 11, but these control circuits 1
2, the radiation fins 13 and the cooling electric motor 14 can be arranged outside the housing 11. in this case,
A duct connecting the cooling electric motor 14 and the inside of the housing 11 may be arranged so that the cooling air from the cooling electric motor 14 can be supplied also into the housing 11.

[0054]

Since the present invention is configured as described above, it has the following effects. A cooling device for an automobile generator is provided with an electric motor having a cooling fan, and a drive power source input terminal of the electric motor is connected to a field winding in parallel or in series. As a result, it is possible to realize a cooling device for an automobile generator, which has a simple structure and is capable of obtaining appropriate cooling air even when the vehicle is running at low speed.

Further, in a cooling device for an automobile generator, an opening / closing switch that can be opened / closed based on a command signal corresponding to a radiator cooling water temperature from an automobile engine control device, and a driving power input to the opening / closing switch. A cooling electric motor to which a terminal is connected is provided, and the opening / closing switch is closed and the electric motor is driven when the cooling water temperature becomes equal to or higher than a predetermined temperature. Thus, it is possible to realize a cooling device for a generator for an automobile, which has a simple structure and is capable of obtaining an appropriate cooling wind even when the vehicle is low in speed when traveling wind cannot be expected.

Further, in the cooling device for the automobile generator, the start command for determining whether the command value of the passing current to the field winding of the voltage control means is equal to or more than the predetermined value and outputting the fan start command signal. The open / close switch includes a generator, an open / close switch that can be opened / closed based on a fan start command signal from the start command generator, and an electric motor to which the drive power input terminal is connected to the open / close switch. When the current flowing through the winding exceeds a predetermined current, the winding closes and the electric motor is driven. As a result, as described above,
It is possible to realize a cooling device for a generator for an automobile, which has a simple structure and is capable of obtaining an appropriate cooling wind even when the vehicle is low in speed when traveling wind cannot be expected.

Further, in the cooling device for the automobile generator, when the rotation speed of the engine exceeds a predetermined rotation speed,
An opening / closing switch that is opened by centrifugal force and an electric motor to which the drive power input terminal is connected to the opening / closing switch are provided, and the opening / closing switch closes when the engine rotation speed becomes lower than a predetermined rotation speed, The electric motor is driven.
As a result, similar to the above, although the configuration is simple,
It is possible to realize a cooling device for an automobile generator that can obtain an appropriate cooling air even when the vehicle is low in speed where traveling air cannot be expected.

[Brief description of drawings]

FIG. 1 is a schematic circuit configuration diagram of a cooling device for an automobile generator that is a first embodiment of the present invention.

FIG. 2 is a schematic circuit configuration diagram of a cooling device for an automobile generator that is a second embodiment of the present invention.

FIG. 3 is a schematic circuit configuration diagram of a cooling device for an automobile generator that is a third embodiment of the present invention.

FIG. 4 is a schematic circuit configuration diagram of a cooling device for an automobile generator that is a fourth embodiment of the present invention.

FIG. 5 is a schematic circuit configuration diagram of a cooling device for an automobile generator that is a fifth embodiment of the present invention.

FIG. 6 is a schematic cross-sectional configuration diagram of an automobile generator.

FIG. 7 is a schematic perspective view of a control circuit, a radiation fin, and a cooling electric motor.

FIG. 8 is a graph showing a relationship between a generated current and a current supplied to a field coil due to a difference in engine rotation speed.

FIG. 9 is a graph showing the relationship between the generated current and the voltage of the cooling electric motor depending on the difference in engine speed.

[Explanation of symbols]

 1 Shaft 2 Bearing 3 Pulley 4 Slip ring 5 Brush 6 Field coil 7 Rotor 8 Stator 9 Stator coil 10 Built-in fan 11 Housing 12 Control circuit 13 Radiating fin 14 Cooling electric motor 15, 16 switch 17 Governor switch 18 Cooling water temperature sensor 20 Battery 22 Engine control unit 121 Rectifier diode 122 IC regulator

Front page continued (72) Inventor Keiichi Masuno 2520 Takaba, Katsuta City, Ibaraki Prefecture Hitachi Ltd. Automotive Equipment Division

Claims (7)

[Claims] 1. A cooling device for an automobile generator, comprising: an armature winding; a field winding; and a voltage control means for controlling a current flowing through the field winding and a generated voltage. A cooling device for an automobile generator, comprising an electric motor having a fan, wherein a drive power input terminal of the electric motor is connected in parallel to the field winding. 2. A cooling device for an automobile generator, comprising: an armature winding; a field winding; and voltage control means for controlling a current flowing through the field winding and a generated voltage. A cooling device for an automobile generator, comprising an electric motor having a fan, wherein a drive power input terminal of the electric motor is connected in series to the field winding. 3. A cooling device for an automobile generator, comprising: an armature winding; a field winding; and a voltage control means for controlling a current flowing through the field winding and a generated voltage. An open / close switch, one end of which is connected to one output terminal of the voltage generated by the armature winding and which can be opened / closed based on a command signal corresponding to the cooling water temperature of the radiator from the engine control device of the vehicle, A motor having a cooling fan, the drive power input terminal of which is connected between the other end of the open / close switch and the other output terminal of the voltage generated by the armature winding; The opening / closing switch is closed when the cooling water temperature is equal to or higher than a predetermined temperature, and the electric motor is driven. 4. A cooling device for an automobile generator, comprising: an armature winding; a field winding; and a voltage control means for controlling a current flowing through the field winding and a generated voltage. The voltage generated by the armature winding and the start command generating means that determines that the passing current command value to the field winding of the voltage control means exceeds a predetermined value and outputs a fan start command signal. One of the output terminals is connected to one end thereof, and has an opening / closing switch which can be opened / closed based on a fan start command signal from the start command generating means, and a cooling fan, and the other end of the open / close switch is connected to the output terminal. An electric motor whose drive power input terminal is connected to the other output terminal of the voltage generated by the armature winding, and the opening / closing switch, wherein the current flowing through the field winding is a predetermined current. Close when Becomes, the cooling apparatus for an automobile generator, characterized in that the electric motor is driven. 5. A cooling device for an automobile generator, comprising: an armature winding; a field winding; and voltage control means for controlling a current flowing through the field winding and a generated voltage. Is arranged on a rotor that rotates in response to the rotation of the engine, and when the rotation speed of the engine exceeds a predetermined rotation speed, it is opened by centrifugal force and one end of the armature winding is connected to one terminal. An opening / closing switch, a cooling fan, and an electric motor having a driving power input terminal connected between the other end of the opening / closing switch and the other terminal of the armature winding. The opening / closing switch is closed when the engine rotation speed becomes lower than a predetermined rotation speed, and the electric motor is driven. 6. The cooling device for an automobile generator according to claim 5, wherein the opening / closing switch has an engine rotation speed lower than a predetermined rotation speed of 500 to 2500 rotations per minute. A cooling device for an automobile generator, characterized in that it is closed. 7. The cooling device for an automobile generator according to any one of claims 1 to 5, wherein the electric motor is arranged close to the voltage control means, and cooling air by the electric motor is A cooling device for an automobile generator, which is supplied to a voltage control means.