JP2000125599A - Ac generator and vehicle using it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To further improve the safety of an AC generator by preventing the temperature of the generator from rising by controlling the current generated from the generator in accordance with the temperature values detected by means of temperature detecting sensors which detect the temperature of a liquid coolant. SOLUTION: An AC generator 1 for vehicle is connected to a pulley 102 arranged on its rotating shaft and another pulley 31 arranged on the shaft of an engine 2 through a belt 32. In order to cool the generator 1, a liquid coolant pump 6 which is connected to the radiator 5 of an automobile for heat exchange through two radiator hoses 4 and circulates a liquid coolant is arranged on the outlet side of the radiator 5. In order to detect the temperature of the liquid coolant, in addition, an inlet-side liquid temperature detecting sensor 117 is provided on the inlet side of the hoses 4 and an outlet-side liquid temperature detecting sensor 118 is provided on the outlet side of the hoses 4. The values detected by means of the sensors 117 and 118 are inputted to the ECU 1000 of an engine controller and used for controlling the current generated from the generator 1. Therefore, the heating value of the generator 1 can be prevented from rising by controlling the current generated from the generator 1 upon detecting abnormality in the cooling system.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an alternator and a vehicle using the alternator, and more particularly to detecting an abnormality in a mechanism for cooling the alternator.

[0002]

2. Description of the Related Art In recent years, the output current required for an automotive alternator has been increasing due to the electronic control of various parts as well as the engine of a car and the increase of new mounted parts typified by a navigation system. I have. As a result, the calorific value of the vehicle alternator tends to increase, but the space around the vehicle alternator attached to the engine body also decreases, and the cooling effect by ventilation tends to be insufficient.

As a countermeasure, there has been proposed a technique for cooling a vehicle alternator by using a coolant for an engine.
One example is disclosed in Japanese Patent Application Laid-Open No. 3-178540. In the AC generator having a cooling structure using air, a cooling means using a coolant of an engine is used as a cooling means for cooling a semiconductor diode and a regulator section which generate heat.

[0004]

However, the above-mentioned prior art does not mention a method of controlling the regulator, and protects the alternator against a rise in liquid temperature due to clogging of the cooling liquid passage and overheating of the engine. There remains a problem with regard to considerations.

[0005] It is an object of the present invention to prevent a rise in the temperature of an alternator when the cooling system of the alternator has an abnormality, thereby further improving safety.

[0006]

SUMMARY OF THE INVENTION The present invention provides a coolant passage through which a coolant flows, a temperature detection sensor for detecting the temperature of the coolant, and a temperature detection sensor for detecting the temperature of the coolant. And an electronic circuit for controlling the generated current.

Preferably, the temperature detection sensor detects a temperature of a coolant inflow portion of the coolant passage and a temperature of a coolant outflow portion of the coolant passage, and the electronic circuit determines the temperature based on a difference between the detected temperatures. It is an AC generator that controls the generated current.

Preferably, when the temperature value detected by the temperature detection sensor exceeds a predetermined first allowable value, the electronic circuit suppresses an increase in generated current. The alternator controls the power generation to be stopped for a certain period of time when the temperature value detected by the temperature detection sensor exceeds a predetermined second allowable value.

Preferably, the AC generator further includes an IC regulator for controlling a generated current, and the temperature detection sensor is an AC generator provided at a position where the temperature of the IC regulator affects.

Preferably, the alternator further includes a diode for rectifying a generated current, and the temperature detection sensor is an alternator provided at a position where the temperature of the diode affects.

Preferably, the alternator is an alternator further having a signal terminal for outputting a temperature signal of the coolant to an engine control unit.

The present invention also provides a coolant passage through which a coolant flows, a signal terminal for inputting a temperature signal of the coolant from an engine control unit, and power generation in accordance with the value of the temperature signal input from the signal terminal. An electronic circuit for controlling current.

The present invention also provides an engine, an engine control unit for controlling the engine, an engine coolant passage, and a generator coolant passage for circulating the coolant diverted from the engine coolant passage. A vehicle having an internal alternator and a signal line connecting between the engine control unit and the alternator, wherein the signal line transmits a coolant temperature of the engine coolant passage to the alternator; It is.

The present invention also provides an engine, an engine control unit for controlling the engine, an engine coolant passage, and a generator coolant passage for circulating the coolant diverted from the engine coolant passage. An alternator provided therein; and a signal line connecting between the engine control unit and the alternator, wherein the signal line transmits a coolant temperature of the alternator coolant passage to an engine control unit. Vehicle.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to FIGS.

FIG. 1 is an overall configuration diagram of an automobile showing a schematic configuration of a cooling system for cooling the vehicle alternator 1. FIG.
, The vehicle alternator 1 is connected to the engine 2 by a pulley 102 disposed on a rotating shaft of the vehicle alternator 1.
And belt 3 on pulley 31 arranged on the axis of engine 2
2 are connected. The speeds of the pulley 102 and the pulley 31 are two to three times as high as those of the vehicle alternator 1. The cooling of the vehicle alternator 1 is connected by two radiator hoses 4 for heat exchange by a radiator 5 of the vehicle, and a coolant pump 6 for circulating a coolant flowing inside is provided at an outlet of the radiator 5. Placed on the side. Normally, the coolant pump 6 is connected to a pulley 31 of the engine 2 (not shown), and can send a water amount proportional to the rotation speed of the engine 2. After passing through the coolant pump 6, the coolant coming out of the radiator 5 is also used for cooling the engine 2. The coolant discharged from the engine 2 is connected to a radiator hose 4 on the outlet side of the vehicle alternator 1.

In the vehicle alternator 1, an inlet-side liquid temperature detection sensor 117 is provided at the inlet side of the radiator hose 4.
A liquid temperature detection sensor 118 is provided on the outlet side to detect the temperature of the coolant. The detected value is input to ECU 1000 which is an engine control unit, and is used for controlling the generated current of AC generator 1 for vehicle as shown in FIG.

In this embodiment, since the coolant of the AC generator is shared with the engine coolant, the coolant temperature is input as a signal from the ECU 1000 which knows the coolant temperature on the engine side. May be. By doing so, there is no need to provide a double coolant temperature sensor,
This contributes to a reduction in the number of parts. In this case, the coolant temperature may be the coolant temperature on the inlet side of the engine, the coolant temperature on the outlet side, or both. In this case, it is necessary to provide a terminal for receiving a signal from the ECU in the vehicle alternator.

Conversely, since the coolant of the AC generator is shared with the engine coolant, the temperature of the coolant of the AC generator may be output to ECU 1000 as a signal. In such a case, the ECU 1000 can treat the temperature signal as the engine coolant temperature and set the coolant temperature sensor to two.
There is no need to provide a double weight, which contributes to a reduction in the number of parts.

FIG. 2 is a correlation diagram for explaining the control of the generated current based on the coolant temperature detected by the liquid temperature detection sensor. The horizontal axis shows the difference between the outlet temperature of the coolant flowing out of the automotive alternator 1 and the inlet temperature of the incoming coolant, and the vertical axis shows the outlet temperature of the coolant flowing out of the vehicle alternator 1. Is shown.

In FIG. 2, the upper limit of the temperature difference Δt between the outlet and the inlet of the liquid temperature when the generated current is large is determined to the value indicated by the symbol t2 in the figure in the range of the normal use area. Further, in the range of the normal use area, the temperature difference Δt between the outlet and the inlet when the amount of generated heat is small and the generated current is small.
Is determined to the value indicated by the symbol t1 in the figure.
During normal operation, the difference Δt between the outlet and inlet coolant temperatures operates within the range between t1 and t2. In other words, when the temperature difference Δt between the outlet and the inlet is equal to or less than t1 or equal to or more than t2, it is outside normal operation, and it can be estimated that there is some failure.

For example, if the temperature difference Δt between the outlet and the inlet is less than t1, it is because the amount of power generated by the vehicle alternator 1 is small, and it is considered that there is an abnormality. When the temperature difference Δt between the outlet and the inlet is equal to or greater than t2, it is considered that the required amount of the coolant does not flow, and the generated current is limited. Further, in order to notify the driver of this abnormality, for example, a charge lamp is blinked and displayed.

The vertical axis in FIG. 2 indicates the temperature of the coolant on the outlet side, and an allowable temperature is provided. When the temperature of the coolant on the outlet side is high, it is considered that the cooling capacity of the radiator 5 has decreased, and overheating of the engine, water leakage of the radiator, and the like are considered. Then, in order to overcome the problem caused by poor cooling of the vehicle alternator 1, the control is performed so as to limit the generated current or stop the power generation. Further, in order to inform the driver of this abnormality, for example, a charge lamp is turned on to display the information.

As described above, when the generated current is limited, the charge lamp blinks, and when the power generation is stopped, the charge lamp is turned on. It is convenient to know.

FIG. 3 is a block diagram for realizing the operation of FIG.

The sensor for detecting the temperature may be any sensor capable of detecting the temperature range of -40 ° C. to 140 ° C., which is a temperature range of the coolant temperature. In this case, the sensor is made of copper and constantan (an alloy of copper and nickel). A thermocouple (thermocouple) was used. In this case, steel is a positive electrode and constantan is a negative electrode.

The two sensors 117 and 118 for detecting the liquid temperature are provided with an A / D which can input an analog voltage of a control circuit provided in the IC regulator 113 for controlling the field winding current described above. A / D1 and A / D of converter 1
D2.

In FIG. 3, the inlet side liquid temperature detecting sensor 117 for detecting the liquid temperature of the cooling fluid of the generator is connected to A / D1, and the signal of the outlet side liquid temperature detecting sensor 118 is connected to A / D2. . The output of the control circuit is the power transistor 11
9 bases.

Further, between the collector of the power transistor 119 and the battery power supply to which the generated voltage is connected,
Temperature fuse 120, brush 11 from battery power supply side
1, the slip ring 110, the field winding 107, the slip ring 110, and the brush 111 are connected in this order.

The control circuit described above is constituted by a microcomputer or the like. The output port connected to the base of the power transistor uses a PWM boat whose duty can be controlled.

This thermocouple (thermocouple) is internally digitized by the analog / digital conversion circuit of the control circuit described above to calculate a temperature difference. By controlling the duty of the power transistor 119 based on the calculated temperature difference, the field current flowing through the field winding 107 is controlled, and the generated current is controlled. For example, in a state where the duty with respect to the generated current is 100% and the field current is flowing at the maximum, if the temperature difference detected by the temperature sensor exceeds an allowable value, the duty of the PWM is reduced to about 80%. Is controlled as follows.

However, when the control cannot be performed normally due to abnormality or malfunction of the liquid temperature detecting sensor, the heat quantity of the generator may be extremely large. In view of this, the above-described thermal fuse 120 is arranged in a portion where the time constant of the temperature rise is short, so that when the temperature exceeds the allowable value, power generation becomes impossible. Specifically, the above-described thermal fuse 120 is disposed on the cooling fin of the diode with a thin insulator interposed therebetween, and when the thermal fuse 120 is melted, the field current is prevented from flowing and power generation is disabled. Is what you do. Since the liquid temperature detection control cannot be performed when the control means breaks down as described above, the temperature of a portion such as a diode having a small temperature rise time constant is monitored.

FIG. 4 is a flowchart for explaining the operation.

First, the liquid temperature on the input side is detected, and if it is lower than the allowable temperature, the temperature difference is calculated. If the temperature difference is a normal value, normal field current control is performed. If the temperature difference is small, the charge lamp blinks to notify the driver of the abnormality. Further, when the temperature difference is large, it is considered that the amount of water is insufficient, so that the operation is performed by reducing the amount of power generation, and similarly, the charge lamp is flashed to notify the driver of the abnormality.

At this time, it is determined whether the reduction ratio of the generated current should be reduced to a ratio related to the temperature difference, or approximately 50% to 80%. Then, even in such a control state, when the liquid temperature on the inlet side becomes equal to or higher than the allowable value, control is performed so as to stop power generation for self-defense.

Next, a second embodiment of the present invention will be described with reference to FIGS. FIG. 5 is a longitudinal sectional view showing the configuration of the vehicle alternator 1. The automotive alternator 1 includes two brackets. The bracket includes a front bracket 103 disposed on the pulley 102 side and a rear bracket 104 disposed on the opposite side of the pulley 102. A shaft 101 is supported at the center of both brackets via bearings. A pulley 102 is attached to one end of the shaft 101, and a slip ring 110 is attached to the other end. The pulley 102 is connected to the pulley 31 disposed on the output shaft of the engine 2 via the belt 32 shown in FIG. 1, and the shaft 101 is rotated by the engine 2.

A brush 111 is slidably attached to the slip ring 110, and supplies electric power from the brush 111 to a field winding 107 described later. Also, the shaft 101
A rotor (rotor) is attached to the center of the.
A claw-shaped magnetic pole 108 having a claw shape is arranged on the outer periphery of the rotor. A field winding 1 is provided at the center of the rotor.
07 is wound, and the slip ring 1
10 to allow the claw-shaped magnetic pole 1 to flow.
08 is magnetized.

The front bracket 10 on the pulley 102 side
3 and a housing 115 having a stator core 105 built in between the rear bracket 104 on the opposite side of the pulley 102.
The inner peripheral surface of the stator core 105 is disposed at a slight distance from the claw-shaped magnetic pole 108 of the rotor. This interval is a predetermined interval required from the relationship of mechanical characteristics, and is generally set to about 0.4 mm.

Teeth and slots are arranged on the stator core 105, and a stator winding 106 is wound in three phases in a slot corresponding to a concave portion of the stator core 105.
When the claw pole 108 is rotated and magnetized, the stator winding 1
At 06, a three-phase induced voltage is generated.

Inside the rear bracket 104, a diode plus fin 109a and a diode minus fin 109b constituting a rectifier circuit are fixed to a rear plate 112 for sealing a water channel 114. Also,
IC regulator 113 for adjusting the generated voltage
It is fixed so as to be in contact with the rear bracket 104.
Further, FIG. 1 shows an arrangement in which an inlet-side liquid temperature detection sensor 117 and an outlet-side liquid temperature detection sensor 118 are provided near the entrance and exit of the radiator hose 4.
One liquid temperature detection sensor 116 is an IC regulator 113
At the same time, it is provided so as to be in contact with the rear bracket 104 so that the temperature of the coolant flowing through a portion near the outlet side of the water channel 114 can be detected.

The diode plus fin 109a is connected to the plus electrode of the battery (not shown), and the diode minus fin 109b has the same potential as the main body of the AC generator, and is electrically connected to the minus terminal of the battery (not shown). . These diodes convert the AC induced voltage generated in the stator winding 106 into a DC voltage by full-wave rectification. The IC regulator 113 has a DC voltage rectified by a diode of approximately 1 to charge the battery.
The field winding current is controlled so as to maintain a constant voltage of about 4.3V.

The vehicle alternator 1 configured as described above
When the pulley 102 is rotated by the driving of the engine 2, the shaft 101 rotates together with the slip ring 110 and the rotor, and a DC current from the brush 111 is supplied to the field winding 107 inside the rotor, so that the field Winding 10
7 operates so that each magnetic pole of the claw-shaped magnetic pole 108 forms an N pole and an S pole. The magnetic flux generated by the field winding 107 is emitted from the claw of the N-pole claw-shaped magnetic pole, passes through the stator core 105, and returns to the claw of the S-pole claw-shaped magnetic pole to form a magnetic circuit. When the magnetic flux of this magnetic circuit crosses the stator winding 106, a three-phase induced voltage is generated in the stator winding 106. The three-phase induced voltages are full-wave rectified by a diode group arranged in the diode plus fin 109a and the minus fin 109b, and are converted into a DC voltage. The rectified DC voltage is adjusted by the IC regulator 113, and is maintained at a constant voltage of about 14.3V. In addition, when the permanent magnet is arranged between the claw magnetic poles so that the same poles face each other, the generated current can be increased.

Next, a method of cooling the heat generated by the copper loss generated in the stator winding 106 will be described. The stator core 105 on which the stator windings 106 are arranged is the housing 1
15 is fixed by a flap or the like so that heat generated by copper loss generated in the stator winding 106 can be generated by the housing 1.
It has a structure that is easy to convey to 15. Although not shown, the stator winding 106
And the inner surface of the housing 115
A heat radiation path for heat may be provided by a resin having high heat conductivity.

A plurality of holes penetrate the housing 115 in the axial direction, and a water passage is formed in a zigzag manner by the front bracket 103 and the rear plate 112. The cooling liquid is configured to flow through a zigzag water channel on the outer peripheral surface of the stator core 105, and can cool the entire peripheral surface of the stator core 105. The heat generated by the copper loss of the field winding 107 generated inside the rotor is generated on the surface of the front bracket 103 and the housing 115 on the inside of the opposite side to the pulley 102, in contact with the axial surface of the rotor with a slight gap. The structure allows heat dissipation.

Thus, by arranging the surface in the axial direction and the outer peripheral surface with respect to the rotor so as to be in contact with the water passage through which the cooling liquid passes, the cooling of the entire rotor can be promoted.

Although not shown, the housing 11
Eight water passages 114 are provided at 5 and the flow of the cooling liquid flows from the rear side and is turned back by the front bracket 103, and flows back to the front side and turns back to the rear side. It was configured to exit from In this way, by making the water channel 114 an even number, it is possible to provide a plumbing pipe in the same direction, and the radiator hose 4 can be easily handled. Further, by disposing the hose joint for water supply and drainage on the side opposite to the pulley, it is possible to eliminate the possibility of danger of being entangled with the belt.

The liquid temperature detection sensor 116 attached to the above-mentioned rear bracket 104 detects the temperature of the coolant through heat transfer and heat conduction between the rear plate 112 and the rear bracket 104. Strictly, since there is heat that escapes during heat conduction, the detected value may be corrected in consideration of this.

The value detected by the liquid temperature detection sensor 116 is
It is used for controlling the generated current as shown in FIG.

FIG. 6 shows a modification of the second embodiment of the present invention shown in FIG. 5, and is a longitudinal sectional view showing the configuration of the vehicle alternator 1 as in FIG.

In this embodiment, in the configuration shown in FIG.
An IC regulator 113 for adjusting the generated voltage and a liquid temperature detection sensor 116 are arranged on a rear plate 112 for closing a water passage 114 for the coolant. This waterway 11
4 selects not the inlet side but the outlet side, and detects the temperature of the coolant on the outlet side. All other configurations are the same as those in FIG. 5, and thus detailed description is omitted.

According to the configuration shown in FIG. 6, since the heat radiation of the IC regulator 113 is directly transmitted to the coolant through the rear plate 112, the cooling effect is higher than that shown in FIG. Further, since the liquid temperature detection sensor 116 detects the temperature of the coolant through the thickness of the rear plate 112, it can detect a temperature close to the actual coolant temperature.

When the IC regulator 113 and the liquid temperature detection sensor 116 are installed in a place as shown in FIG. 5, in order to avoid the influence of the heat generated by the IC regulator 113 and accurately detect the coolant temperature. Requires that the liquid temperature detection sensor 116 be installed separately from the IC regulator 113. However, as shown in FIG. 6, the liquid temperature detection sensor 1 is set so that the detection surface comes to the rear plate 112 in contact with the coolant.
By arranging the IC 16, the influence of heat generated by the IC regulator 113 can be reduced, and the liquid temperature detection sensor 116 can be built in the IC regulator 113.

The value detected by the liquid temperature detection sensor 116 is
It is used for controlling the generated current as shown in FIG.

FIG. 7 is a time correlation diagram showing the time change of the outlet liquid temperature.

In the case of the first embodiment of the present invention shown in FIG. 2, the temperature difference between the outlet and the inlet of the coolant and the outlet temperature are detected to control the generated current. In the case of the second embodiment of the present invention shown in FIG. 7, the generated current is controlled only by the outlet temperature.

The coolant temperature at the outlet side of the automotive alternator 1 is determined by the liquid temperature detection sensor 116 shown in FIG. 5 or FIG.
Is detected by The temperature of the coolant on the outlet side rises with power generation, but an abnormality is detected by setting the following determination conditions in advance. Normally, when the generated current increases, the amount of heat generated increases, so that the temperature of the coolant increases.
If the coolant is circulating normally, the time constant at which the liquid temperature rises is generally several minutes. When the cooling capacity is insufficient, as shown by the saturation time tα in the figure, a phenomenon occurs in which the temperature of the liquid rises rapidly or exceeds a certain time tβ. In such a case, it is considered that the coolant pump 6 is abnormal, the radiator 5 leaks water, the water channel 114 inside the vehicle alternator 1 is clogged, or the like. To control.

As shown in FIG. 7, this control is executed by providing two allowable temperatures. When the outlet temperature exceeds the allowable temperature 1, the generated current is limited. And at this time, the charge lamp blinks,
Display the abnormality to the driver. When the temperature exceeds the allowable temperature 2, the power generation is stopped, the charge lamp is turned on, and the abnormality is displayed to the driver.

As described above, if the generated current is controlled in accordance with the rise in the temperature of the outlet side of the coolant, damage to the vehicle alternator 1 can be prevented.

Although not shown in the figure, instead of using the lighting of the charge lamp, the driver is informed that the charging system has entered the control mode at the time of abnormality, or what kind of situation is present. Is provided, so that the driver can be prompted to move the car to a repair shop before a trouble occurs. For example, the content of the abnormal mode of the charging system may be displayed by a mark or a word on the display panel.

In the above-described embodiment, the cooling system of the engine 2 is used for cooling the vehicle alternator 1.
It goes without saying that a cooling system dedicated to the vehicle alternator 1 may be provided.

As described in the above embodiment, by adopting the configuration of the present invention, the abnormality of the cooling system is determined by the temperature rise of the coolant for cooling the vehicle alternator, the temperature difference between the inlet and the outlet, etc. And controlling the generated current to prevent an increase in the heat generation of the vehicle alternator.

Further, by providing a means for informing the driver of such a control mode, the vehicle can be repaired quickly, so that there is an effect that a sudden stop on the road can be prevented.

[Brief description of the drawings]

FIG. 1 is an entire configuration diagram of an automobile showing a schematic configuration of a cooling system for cooling an automotive alternator.

FIG. 2 is a correlation diagram illustrating control of a generated current based on a coolant temperature detected by a liquid temperature detection sensor.

FIG. 3 is a configuration diagram for realizing the operation of FIG. 2;

FIG. 4 shows a flowchart of the operation of FIG.

FIG. 5 is a longitudinal sectional view showing the configuration of the vehicle alternator.

FIG. 6 is a longitudinal sectional view showing the configuration of the automotive alternator.

FIG. 7 is a time correlation diagram showing a time change of an outlet liquid temperature.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... AC generator for vehicles, 2 ... Engine, 4 ... Radiator hose, 5 ... Radiator, 6 ... Cooling water pump, 31 and 1
02 ... pulley, 32 ... belt, 103 ... front bracket, 104 ... rear bracket, 112 ... rear plate, 113 ... IC regulator, 114 ... water channel, 115
... Housing, 116: Liquid temperature detection sensor, 117: Inlet-side liquid temperature detection sensor, 118: Outlet-side liquid temperature detection sensor.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Yoshiaki Honda 2520 Oita Takaba, Hitachinaka-shi, Ibaraki Co., Ltd. Within the Hitachi, Ltd. Automotive Equipment Group (72) Inventor Masami Takano 2520 Oita-Koba, Hitachinaka-shi, Ibaraki Co., Ltd. Hitachi, Ltd. Automotive Equipment Group (72) Inventor Toshiyuki Innam, 2520 Oji Takaba, Hitachinaka-shi, Ibaraki Prefecture Hitachi, Ltd. Automotive Equipment Group (72) Inventor Atsushi Suzuki 502, Kandachicho, Tsuchiura-shi, Ibaraki, Japan Inside Ritsumeikan Machinery Research Laboratory

Claims (9)

[Claims] 1. A coolant passage for flowing a coolant, a temperature detection sensor for detecting a temperature of the coolant, and an electronic circuit for controlling a generated current according to a value of the temperature detected by the temperature detection sensor. , Having an alternator. 2. The temperature detection sensor according to claim 1, wherein the temperature detection sensor detects a temperature of a coolant inflow portion and a temperature of a coolant outflow portion of the coolant passage, and the electronic circuit detects the detected temperature. An alternator for controlling the generated current based on a temperature difference. 3. The electronic circuit according to claim 1, wherein when the temperature value detected by the temperature detection sensor exceeds a predetermined first allowable value,
The electronic circuit controls so as to suppress a rise in generated current,
An alternator that controls so that power generation is stopped for a certain period of time when the temperature value detected by the temperature detection sensor exceeds a predetermined second allowable value. 4. The alternator according to claim 1, wherein the alternator further includes an IC regulator for controlling a generated current, and the temperature detection sensor is provided at a position where the temperature of the IC regulator affects. . 5. The alternator according to claim 1, wherein the alternator further includes a diode for rectifying a generated current, and the temperature detection sensor is provided at a position where the temperature of the diode affects. 6. The alternator according to claim 1, wherein the alternator further has a signal terminal for outputting a temperature signal of the coolant to an engine control unit. 7. A coolant passage through which a coolant flows, a signal terminal for inputting a temperature signal of the coolant from an engine control unit, and a power generation current controlled in accordance with a value of the temperature signal input from the signal terminal. An alternator having an electronic circuit. 8. An engine, an engine control unit for controlling the engine, an engine coolant passage, and a generator coolant passage for circulating a coolant diverted from the engine coolant passage. A vehicle comprising: an AC generator; and a signal line connecting between the engine control unit and the AC generator, wherein the signal line transmits a coolant temperature of the engine coolant passage to the AC generator. 9. An engine, an engine control unit for controlling the engine, an engine coolant passage, and a generator coolant passage through which coolant diverted from the coolant in the engine coolant passage is provided. A vehicle comprising: an alternator; and a signal line connecting between the engine control unit and the alternator, wherein the signal line transmits a coolant temperature of the alternator coolant passage to an engine control unit.