JP2866293B2 - Vehicle generator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicular generator driven by the rotation of an engine to supply power to a vehicle-mounted battery and an electric load, and more particularly to a vehicular generator having improved output efficiency regardless of the alternator rotation speed. It is about.

[0002]

2. Description of the Related Art Conventionally, in a vehicle generator of this type, the specification of an armature winding of an alternator is configured to be selectable, and the winding specification is switched according to the alternator rotation speed so that the full-load operation is performed. Output current is always maximized. FIG. 5 is a block diagram schematically showing a conventional vehicular generator described in, for example, JP-A-56-49697. FIG. 6 is a circuit diagram specifically showing the configuration of the alternator in FIG. FIG. 6 is a block diagram showing a functional configuration of a control circuit in FIG.

In FIG. 1, reference numeral 1 denotes an alternator constituting a three-phase AC generator, which includes an output terminal B for supplying an output voltage Vo and an output current Io by power generation to a battery and a load (to be described later), a ground terminal E, A switching control input terminal C to which a switching control signal Co for switching the specification (described later) of the armature winding is applied, and a field current control terminal F for output voltage control to which a field current If is supplied. Have.

[0004] Reference numerals 2 and 4 denote three-phase armature windings provided on the stator of the alternator 1, which are individually Y-connected. Reference numeral 3 denotes a full-wave rectifier circuit connected to each output terminal of the armature winding 2, and includes three pairs of diodes D1 to D6 corresponding to each phase. Reference numeral 5 denotes a full-wave rectifier circuit connected to each output terminal of the armature winding 4 and, like the full-wave rectifier circuit 3, comprises three pairs of diodes D7 to D12 corresponding to each phase.

Reference numeral 6 denotes a field winding provided on the rotor of the alternator 1, and only one field winding is provided in common for each of the armature windings 2 and 4. 7 controls the duty of the field current If flowing through the field winding 6 and outputs the output voltage V of the alternator 1.
This is a regulator for adjusting o to a predetermined voltage, and is built in the alternator 1.

Reference numeral 8 denotes a battery connected between the output terminal B and the ground terminal E of the alternator 1, and 9 denotes a load connected in parallel with the battery 8, and the output voltage V of the alternator 1
o and the output current Io are supplied. IB is a current flowing through the battery 8 in the charging direction, L is a terminal of the load 9 to which the output voltage Vo of the alternator 1 is applied, and VL is a load 9
Is a current flowing through the load 9.

The terminal L of the load 9 is also an input terminal of the battery 8 and functions as a voltage detection terminal. Terminal voltage VL
Is substantially equal to the output voltage Vo of the alternator 1 and is fed back to the regulator 7. The output current Io of the alternator 1 is equal to the sum of the currents IB and IL.

D13 and D14 are diodes inserted between the output terminals of the full-wave rectifier circuits 3 and 5, and the cathode of the diode D13 is connected to the output terminal B to connect the full-wave rectifier circuits 3 and 5 in parallel. The anode of the diode D14 is connected to the ground terminal E.

The SCR is a thyristor inserted between the anode of the diode D13 and the cathode of the diode D14. The anode is connected to the anode of the diode D13, the cathode is connected to the cathode of the diode D14, and the gate is connected to the switching control input. Controlled by terminal C.
The thyristor SCR constitutes a selection switching means for selectively connecting the full-wave rectifier circuits 3 and 5 in series and switching the specifications of the armature windings 2 and 4.

Reference numeral 10 denotes a control circuit for operating a thyristor SCR (selection switching means) according to the rotation speed N of the alternator 1, and is constituted by the following 11 to 13 (see FIG. 7).

Reference numeral 11 denotes a rotation speed detecting means for detecting an alternator rotation speed N based on, for example, a rotation speed signal No corresponding to the output voltage of the armature winding 2 or 4. Reference numeral 12 denotes an alternator rotation speed N for each winding specification. Current cross point rotation speed NI of each characteristic curve of output current Ios at full load
Is a current cross point setting means for setting 13 is an alternator rotation speed N and a current cross point rotation speed NI
This is a comparison determining means for generating the switching control signal Co based on the comparison result with the above, and is configured to select a connection specification in which the output current Ios of the alternator 1 at full load is increased.

FIG. 8 shows the output current Ios at full load with respect to the alternator rotation speed N for each winding specification when the output voltage Vo of the alternator 1 is constant (that is, the output voltage of the alternator 1 is maintained at a predetermined value Vo). FIG. 6 is a characteristic diagram showing a characteristic curve of a maximum output current that can flow from the alternator 1 in a state.

In the figure, Io1 (solid line) represents the output current of the armature windings 2 and 4 when the full-wave rectifier circuits 3 and 5 are connected in series (first winding specification), and Io2 (dashed line) represents all Currents of armature windings 2 and 4 when wave rectifier circuits 3 and 5 are connected in parallel (second winding specification), Nη and NI are the efficiency cross point rotation speed and current of the characteristic curve for each winding specification Crosspoint speed,
Z1 is a low-speed rotation region below the efficiency crosspoint rotation speed Nη, Z2 is an intermediate rotation speed region between the efficiency crosspoint rotation speed Nη and the current crosspoint rotation speed NI, Z
Reference numeral 3 denotes a high-speed rotation speed region equal to or higher than the current cross point rotation speed NI.

Η1 and η2 are characteristic curves of the output efficiency of the alternator 1 at full load with respect to the alternator rotation speed N, and η1 (solid line) is the full-wave rectifier circuits 3 and 5.
And η2 (dotted line) is the output efficiency of the armature windings 2 and 4 when the full-wave rectifier circuits 3 and 5 are connected in parallel. In general, the cross point rotation speed Nη of the efficiency η at full load of the alternator 1 is smaller than the current cross point rotation speed NI, as shown in FIG.

Next, the operation of the conventional vehicle generator shown in FIGS. 5 to 7 will be described with reference to FIG. First, at the same time as the start of an internal combustion engine (engine) not shown,
When the voltage of the battery 8 is applied to the regulator 7 and the field current If is supplied to the field current control terminal F, the field winding 6 is excited and the armature windings 2 and 4 are energized, respectively. Start power generation.

Here, when the thyristor SCR is in a conductive state, the full-wave rectifier circuits 3 and 5 are connected in series (first winding specification), and the output current Io of the alternator 1 is changed.
Is a solid line Io1 in FIG. 8 according to the alternator rotation speed N.
Changes as shown in FIG. On the other hand, when the thyristor SCR is in a non-conducting state, the full-wave rectifier circuits 3 and 5 are connected in parallel (second winding specification), and the output current Io of the alternator 1 changes according to the alternator rotation speed N. It changes as shown by the one-dot chain line Io2 in FIG.

That is, as is clear from the characteristic diagram of FIG. 8, when the vehicle is running at a low speed, the output current is greater in the series-connected winding specification state (solid line) than in the parallel-connected winding specification state (dashed line). When the Io rises quickly and the vehicle runs at high speed, a higher output current Io can be obtained in the parallel connection winding specification state (dashed line) than in the series connection winding specification state (solid line).

Therefore, specifically, at the same time when the internal combustion engine is started, the control circuit 10 detects the low-speed alternator rotation speed N and determines that the low-speed alternator rotation speed is equal to or less than the current cross point rotation speed NI. Is supplied to the switching control terminal C. As a result, the thyristor SCR is brought into the conductive state, and the winding is connected in series (solid line in FIG. 8). The current cross point rotation speed NI can be set in advance based on, for example, test data.

Subsequently, when the alternator rotation speed N increases to the current crosspoint rotation speed NI, the comparison determination means 13 in the control circuit 10 determines that the alternator rotation speed N is greater than the current crosspoint rotation speed NI. hand,
The output of the switching control signal Co is stopped. Further, in order to make the anode of the thyristor SCR negative with respect to the cathode, the supply of the field current If from the regulator 7 to the field winding 6 is temporarily stopped to stop the power generation, or the thyristor SCR Apply reverse voltage.

Thus, when the vehicle is running at high speed, the thyristor SCR is turned off, and the winding specifications of the armature windings 2 and 4 of the alternator 1 are in a parallel state. As a result, the output current I of the alternator 1 at full load is
As the alternator rotation speed N increases, os is switched from the solid line characteristic Io1 to the one-dot chain line characteristic Io2 to sufficiently charge the battery 8 and supply it to the load 9 as necessary.

The vehicle generator capable of switching the armature winding of the stator to a plurality of specifications as described above is not limited to the above-mentioned publication, but is disclosed in, for example, JP-A-56-49698 and JP-A-51-1981. No. 16414, Japanese Patent Publication No. 53-810,
Various references are also made to JP-A-2-17899, JP-A-4-96699, JP-A-4-88900, and the like. Further, the selection switching means of the winding specification is not limited to the thyristor SCR, but may be a transistor, a relay, or the like.

In other words, Japanese Patent Laid-Open Publication No. Sho 51-16414 discloses two independent armature windings and two rectifier circuits individually connected to these armature windings. The output terminal is connected to the neutral point of the other armature winding to provide a series specification, and the output terminal of one rectifier circuit is connected to the other output terminal via a diode to provide a parallel specification.

In Japanese Patent Publication No. 53-810, a winding group (X ₂ -U ₂ , Y ₂ -V ₂ , Z _2-
W ₂ ) and independent windings (X ₁ −U ₁ , Y ₁ −
V ₁ , Z ₁ -W ₁ ), and X ₁ ,
A series specifications connects Y _1, Z ₁ to U _2, V _2, W ₂ respectively, are parallel specification by a neutral point by shorting _{X 1, Y 1, Z 1} .

In Japanese Unexamined Patent Publication No. 2-17899, two independent armature windings are connected to a series rectifier circuit via a switch unit, and the switch unit is turned on by a relay device to provide a series specification. By turning off the switch part, the parallel specification is achieved.

Japanese Patent Application Laid-Open No. 4-88900 discloses a rotor having a permanent magnet, another rotor having a field winding connected to a field current reversing circuit, and an independent armature opposed to the rotor. It has a winding and a common rectifier circuit connected to each armature winding, and generates a magnetic flux in the opposite direction from each rotor to make a series specification, and energizes each rotor in the same direction to make a parallel specification. And

In Japanese Unexamined Patent Publication No. 4-96699, a first armature winding connected in a Y-connection and a second armature winding connected in a phase opposite to that of the first armature are separately provided. With two connected rectifier circuits, the phases opposite to each other are connected via a silicon controlled rectifier, and the silicon controlled rectifier is turned on to make it a series type, and the silicon controlled rectifier is turned off to make a parallel type. I have.

However, as described above, the efficiency cross-point rotation speed Nη with respect to the output efficiency η of the alternator 1 is smaller than the current cross-point rotation speed NI.
If it is in the intermediate rotation speed region Z2 between η and NI, the output efficiency η of the alternator 1 will be reduced.

That is, if the alternator rotation speed N is equal to or less than the current cross point rotation speed NI, the solid line characteristic Io1
In this case, if the alternator rotation speed N is equal to or higher than the efficiency cross point rotation speed, the winding specification with the low efficiency η at full load is selected.

[0029]

As described above, the conventional vehicular generator switches the winding specification according to the alternator rotation speed N, and the output current Ios at full load with respect to the alternator rotation speed N is maximum. Therefore, there is a problem that the efficiency is reduced depending on the region of the alternator rotation speed N.

The present invention has been made in order to solve the above-mentioned problems, and an object of the present invention is to provide a vehicular generator in which the output efficiency is maximized.

[0031]

A vehicle generator according to a first aspect of the present invention has an armature winding provided on a stator and a field winding provided on a rotor. An alternator that rectifies the output current from the winding and supplies it to the load,
A regulator for controlling the field current flowing through the field winding to adjust the output voltage of the alternator to a predetermined voltage, a selection switching means for switching the specification of the armature winding to a plurality of different winding specifications, and a rotation of the alternator And a control circuit for operating the selection switching means in accordance with the number of rotations, wherein the control circuit comprises an efficiency cross point rotation of each characteristic curve of output efficiency at full load with respect to the alternator rotation speed in each winding specification. A switching control signal to the selection switching means such that the output efficiency at the full load of the alternator is maximized based on the efficiency cross point setting means for setting the number and the result of comparison between the alternator rotation speed and the efficiency cross point rotation speed. And comparison determination means for generating

According to a second aspect of the present invention, there is provided a vehicle generator according to the first aspect, wherein the control circuit is configured such that a current cross of each characteristic curve of an output current at a full load with respect to the alternator rotation speed in each winding specification. Current cross point setting means for setting the point rotation speed, wherein the comparison determination means compares the alternator rotation speed with the efficiency cross point rotation speed and the current cross point rotation speed, and determines whether the alternator rotation speed is the efficiency cross point rotation speed and the current. When the output current of the alternator is larger than the output current at full load in the intermediate rotation speed region between the cross point rotation speed and
If there is another winding specification having an output current characteristic at full load equal to or greater than the alternator output current, a switching control signal for switching the specification of the armature winding to another winding specification is generated.

According to a third aspect of the present invention, in the vehicle generator according to the second aspect, when there are a plurality of other winding specifications, the comparing and judging means may include a full load of the other winding specifications. It switches to the winding specification that maximizes the output efficiency at the time.

According to a fourth aspect of the present invention, in the vehicle generator according to the second aspect, when there is no other winding specification, the output at full load in the intermediate rotation speed region is provided when there is no other winding specification. This is to switch to the winding specification that maximizes the current.

According to a fifth aspect of the present invention, in the vehicle generator according to any one of the second to fourth aspects, the comparing and judging means is provided when the terminal voltage of the load decreases by a predetermined value or more. It is determined that the output current of the alternator is larger than the output current at full load.

According to a sixth aspect of the present invention, in the vehicle generator according to any one of the second to fourth aspects, the comparing and judging means is provided when the duty of the field current indicates the maximum duty value. , The output current of the alternator is determined to be larger than the output current at full load.

[0037]

According to the first aspect of the present invention, the specification of the armature winding is switched so as to obtain the maximum efficiency by comparing the alternator rotation speed with the efficiency cross point rotation speed.

According to a second aspect of the present invention, the specification of the armature winding is switched based on a comparison between the alternator rotation speed, the efficiency crosspoint rotation speed, and the current crosspoint rotation speed so that the maximum efficiency is obtained. In addition, when the output current of the alternator exceeds the output current at full load in the intermediate rotation speed region between the crosspoint rotation speeds, another winding having an output current characteristic at full load equal to or greater than the output current of the alternator. Switch to wire specification to prevent shortage of output current.

According to a third aspect of the present invention, when there are a plurality of other winding specifications having an output current characteristic at full load equal to or higher than the output current of the alternator in the intermediate rotation speed range, there are provided Switching to the winding specification having the characteristic of maximum efficiency prevents output current shortage and minimizes reduction in efficiency.

According to a fourth aspect of the present invention, when there is no other winding specification having an output current characteristic at a full load equal to or greater than the output current of the alternator in the intermediate rotation speed region, the present invention is not limited to this. To switch to the winding specification having the maximum output current characteristics and minimize the shortage of output current.

According to a fifth aspect of the present invention, when the terminal voltage of the load decreases by a predetermined value or more, it is determined that the output current of the alternator has exceeded the output current at full load, and The switching timing is reliably detected.

According to a sixth aspect of the present invention, when the duty of the field current indicates the maximum duty value,
It is determined that the output current of the alternator has exceeded the output current at full load, and the switching timing of the winding specification is reliably detected.

[0043]

[Embodiment 1] Hereinafter, a first embodiment (corresponding to claim 1) of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing a functional configuration of a control circuit according to a first embodiment of the present invention, and 11 is the same as described above. 10A and 13A correspond to the control circuit 10 and the comparison / determination means 13, and the overall schematic configuration (not shown) and the peripheral configuration of the alternator 1 are as shown in FIGS.

Numeral 14 denotes efficiency cross point setting means for setting the efficiency cross point rotation speed Nη of each characteristic curve (see FIG. 8) of the output efficiency η at full load with respect to the alternator rotation speed N in each winding specification. The cross point rotation speed Nη is set in advance based on, for example, test data and the like, like the current cross point rotation speed NI.

In this case, the comparison determination means 13A selects and switches the output so that the output efficiency η of the alternator 1 at full load becomes maximum based on the result of comparison between the alternator speed N and the efficiency cross point speed Nη. A switching control signal Co for the means is generated.

Next, the operation of the first embodiment of the present invention shown in FIG. 1 will be described with reference to FIG. 5, FIG. 6 and FIG. As described above, the rotation speed detecting means 11 detects the alternator rotation speed N from the rotation speed signal No obtained from the alternator 1, and inputs the detected rotation speed N to the comparison determination means 13A.

The comparison determining means 13A generates a switching control signal Co based on the result of comparison between the alternator rotation speed N and the efficiency cross point rotation speed Nη. That is, in the low-speed rotation region Z1 in which the alternator rotation speed N is equal to or less than the efficiency cross point rotation speed Nη, the thyristor SCR (see FIG. 6) is turned on, and the series (first) winding of the armature windings 2 and 4 is performed. The line specification is selected, and the characteristic curve of the output efficiency η of the alternator 1 is set as shown by a solid line η1 (see FIG. 8).

On the other hand, in the intermediate rotation speed region Z2 and the high speed rotation region Z3 in which the alternator rotation speed N is larger than the efficiency cross point rotation speed Nη, the thyristor SCR
Is turned off, the parallel (second) winding specification of the armature windings 2 and 4 is selected, and the characteristic of the output efficiency η is switched as shown by the one-dot chain line η2. As a result, the alternator 1 can always continue power generation at the maximum efficiency, and can improve the output efficiency η.

Embodiment 2 FIG. However, as mentioned above,
When the second winding specification (dashed line) is selected in the intermediate rotation speed region Z2 in FIG. 8, the output efficiency η at full load is higher than that of the first winding specification (solid line) (η2> η1). However, the output current Ios decreases (Io2 <Io1).

Therefore, when the output current Io of the alternator 1 is required to be larger than the output current Io2 at full load in the intermediate rotation speed region Z2 in which the high-efficiency second winding specification (dashed line) is selected. In addition, the power supply capacity of the alternator 1 becomes insufficient, and it becomes impossible to maintain a stable output voltage Vo. In order to prevent this, when the alternator output current Io that is equal to or more than the output current Ios at full load is detected in the intermediate rotation speed region Z2, the alternator 1
It is desirable to increase the capability of the output current Io.

FIG. 2 is a schematic diagram showing a second embodiment (corresponding to claims 2 and 5) of the present invention, and FIG. 3 is a block diagram showing a functional configuration of the control circuit 10 in FIG. In each figure, 1, 7 to 9, 11, 12, and 14 are the same as those described above. 10B and 13B correspond to the control circuit 10A and the comparison / determination means 13A.

In this case, the control circuit 10B includes not only the efficiency crosspoint setting means 14 but also the current crosspoint setting means 12, and takes in the terminal voltage VL of the load 9. Further, the comparison determination unit 13B generates the switching control signal Co based on the comparison result between the alternator rotation speed N, the efficiency crosspoint rotation speed Nη, and the current crosspoint rotation speed NI, and the terminal voltage VL of the load 9. It has become.

The operation of the second embodiment of the present invention shown in FIGS. 2 and 3 will be described below with reference to FIGS. First, the comparison determination means 13B compares the alternator rotation speed N with each of the crosspoint rotation speeds Nη and NI, and determines that the alternator rotation speed N is an intermediate rotation speed between the efficiency crosspoint rotation speed Nη and the current crosspoint rotation speed NI. It is determined whether or not the area Z2 (Nη <N <NI).

If the alternator rotation speed N is in the intermediate rotation speed region Z2, the second winding specification (dashed line) is selected at this time, and then the terminal voltage VL of the load 9 is output. It is determined whether or not the voltage Vo has dropped by a predetermined value (for example, about 0.3 V) or more. As a result, the output current Io of the alternator 1 becomes equal to the output current Io2 at full load.
It is determined whether it is greater than or equal to.

As described above, the output current Io of the alternator 1 is the sum of the currents IB and IL flowing through the battery 8 and the load 9, and thus is affected by the state of charge of the battery 8. Therefore, even if the current IL flowing through the load 9 is compared with the output current Ios at full load, appropriate control for improving the efficiency of the alternator 1 cannot be realized, and the output current Io and the output current Ios at full load cannot be realized. It is necessary to select the winding specification by comparing with the output current Ios.

That is, assuming that the alternator rotation speed N is in the intermediate rotation speed region Z2 and the second winding specification is selected at this time, the terminal voltage VL of the load 9 (or the battery 8) is changed to the output voltage Vo ( For example, a determination is made as to whether the voltage has dropped from 14.4 V) by a predetermined value (about 0.3 V) or more. If the terminal voltage VL is lower than the output voltage Vo, the output current Io of the alternator 1
This means that the output current Ios is larger than the full load output current Ios that can be supplied while maintaining o, so it can be determined whether or not Io> Ios based on the presence or absence of a voltage drop of a predetermined value or more.

When the comparing and judging means 13B judges that the output current Io of the alternator 1 exceeds the output current Io due to the decrease of the terminal voltage VL of the load 9, it judges that the output current Ios at full load is larger than Io2. Output current I
If there is another winding specification having an output current characteristic at full load that is equal to or more than o, the specifications of the armature windings 2 and 4 are changed to other winding specifications (in this case, the first winding specification shown by a solid line in FIG. 8). Winding specifications)
To generate a switching control signal Co for switching to.

As a result, the capability of the output current Ios at the time of full load increases, and stable power can be supplied to the load 9 and the battery 8. The winding specification selecting operation in the other rotation speed regions Z1 and Z3 and the winding specification selecting operation when the output current Io of the alternator 1 is not detected to be excessive are the same as those described above, and the output efficiency η is improved. Will be given priority.

Embodiment 3 FIG. In the first and second embodiments, two types of winding specifications are switched.
By providing a plurality of selection switching means, it is possible to adopt a configuration for switching to an arbitrary number of winding specifications. Therefore, in the second embodiment, when there are a plurality of winding specifications in which the output current Ios at full load is equal to or more than the output current Io of the alternator 1, the winding specification in which the output efficiency η becomes the maximum is set. It is desirable to choose.

Therefore, in the case of the third embodiment (corresponding to claim 3) of the present invention, the comparison and judgment means 13B (see FIG. 3)
When there are a plurality of other winding specifications in which the output current Ios at full load is equal to or more than the output current Io of the alternator 1 in the intermediate rotation speed region Z2, among these, the output efficiency η at full load is A switching control signal Co for switching to the maximum winding specification is generated. Thereby, even if the output current Io of the alternator 1 exceeds, it is possible to secure the capability of the output current Io and suppress the decrease in efficiency to a minimum.

Embodiment 4 FIG. In the second and third embodiments, the output current Ios under full load is
It is assumed that there is always another winding specification that exceeds the output current Io, but if there is no other winding specification that satisfies this condition, priority should be given to securing the output current Io as much as possible. desirable.

Therefore, in the case of the fourth embodiment of the present invention (corresponding to claim 4), the comparison / determination means 13B makes the output current Ios at full load greater than or equal to the output current Io of the alternator 1 in the intermediate speed range. If there is no other winding specification, a switching control signal Co for switching to the winding specification that maximizes the output current Ios at full load is generated. Thereby, even if the output current Io of the alternator 1 exceeds, it is possible to minimize the insufficiency of the output current Io.

Embodiment 5 FIG. Further, the above-described Embodiments 2 to 4
In the above, the terminal voltage VL of the load 9 is detected in order to determine whether the output current Io of the alternator 1 is exceeded. (Corresponding to the duty of the field current If).

FIG. 4 is a block diagram showing a functional configuration of a control circuit according to a fifth embodiment (corresponding to claim 6) of the present invention, wherein 1, 7, 11, 12 and 14 are the same as those described above. 10C and 13C are control circuits 13B
And the comparison determination means 13B.

In this case, the control circuit 10 C determines the field current If from the output signal of the field current control terminal F of the regulator 7.
And a duty detecting means 15 for detecting the duty D of the control signal. Further, the comparison determination means 13C takes in the alternator rotation speed N, the duty D of the field current If, the efficiency crosspoint rotation speed Nη, and the current crosspoint rotation speed NI, and performs a switching control signal Co.

The comparison / determination means 13C compares and determines the duty D based on the output signal of the field current control terminal F, and determines that the duty D of the field current If is the maximum duty value (100%).
%), It is determined that the output current Io of the alternator 1 is larger than the output current Ios at full load. As a result, the switching control signal Co for giving priority to the output current Io is output as described above, and the armature winding 2 in the alternator 1 is output.
And 4 are switched to, for example, the first winding specification (solid line in FIG. 8).

Therefore, according to the fifth embodiment of the present invention, similarly to the second embodiment, the switching timing of the winding specification can be reliably determined, and the output current Io of the alternator 1 can be secured. it can.

Embodiment 6 FIG. In each of the first to fifth embodiments, the thyristor SCR is used as the selection switching means, taking the alternator 1 having the configuration shown in FIG. 6 as an example.
As described above, any configuration of the alternator 1 can be applied, and any selection switching means such as a transistor or a relay can be applied. It goes without saying that the same operation and effect as those of the embodiment are obtained.

[0069]

As described above, according to the first aspect of the present invention, there are provided the armature winding provided on the stator and the field winding provided on the rotor, and An alternator that rectifies the output current and supplies it to the load, a regulator that controls the field current flowing through the field winding to adjust the output voltage of the alternator to a predetermined voltage, and a plurality of armature windings having different specifications. In a vehicle generator including a selection switching means for switching to a winding specification and a control circuit for operating the selection switching means in accordance with the rotation speed of the alternator, the control circuit includes a full load for the alternator rotation speed for each winding specification. Based on the result of comparison between the alternator rotation speed and the efficiency cross point rotation speed, and an efficiency cross point setting means for setting the efficiency cross point rotation speed of each characteristic curve of the output efficiency at the time. And a comparison / judgment means for generating a switching control signal for the selection switching means so that the output efficiency at the time of full load is maximized, so that the specification of the armature winding is always switched so that the efficiency is maximized. In addition, there is an effect that a vehicular generator with the maximum output efficiency is obtained.

According to a second aspect of the present invention, in the first aspect, the control circuit determines the current crosspoint rotation speed of each characteristic curve of the output current at full load with respect to the alternator rotation speed in each winding specification. A current crosspoint setting means for setting, the comparing / determining means comparing the alternator rotation speed with the efficiency crosspoint rotation speed and the current crosspoint rotation speed, and determining whether the alternator rotation speed is the efficiency crosspoint rotation speed and the current crosspoint rotation speed. When the output current of the alternator is larger than the output current at full load, the output current of the alternator is equal to or greater than the output current of the alternator. If there is a wire specification, a switching control signal for switching the armature winding specification to another winding specification is generated, so the maximum With switching the armature windings specifications so that the generator for a vehicle which prevents the shortage of the output current is the effect obtained.

According to a third aspect of the present invention, in the second aspect, when there are a plurality of other winding specifications, the output efficiency at full load among the other winding specifications is determined. Is switched to the maximum winding specification, so that there is an effect that it is possible to obtain a vehicular generator in which the shortage of output current is prevented and the decrease in efficiency is minimized.

According to a fourth aspect of the present invention, in the second aspect, when there is no other winding specification, the comparison / determination means determines whether the alternator rotation speed in the intermediate rotation speed region at full load is sufficient. Since the switching is made to the winding specification in which the output current is maximized, there is an effect that the output efficiency can be maximized and a vehicle generator in which the shortage of the output current is minimized can be obtained.

According to a fifth aspect of the present invention, in any one of the second to fourth aspects, when the terminal voltage of the load decreases by a predetermined value or more, the output current of the alternator is reduced. Is determined to be larger than the output current at the time of full load, so that there is an effect that a vehicle generator capable of reliably detecting the winding specification switching timing when the output current of the alternator is exceeded is obtained.

According to a sixth aspect of the present invention, in any one of the second to fourth aspects, when the duty of the field current indicates the maximum duty value, the output of the alternator is determined. Since it is determined that the current is larger than the output current at the time of full load, there is an effect that a vehicle generator capable of reliably detecting the winding specification switching timing when the output current of the alternator is exceeded is obtained.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a functional configuration of a control circuit according to a first embodiment (claim 1) of the present invention;

FIG. 2 is a configuration diagram schematically showing a second embodiment (claims 2 and 5) of the present invention.

FIG. 3 is a block diagram illustrating a functional configuration of a control circuit in FIG. 2;

FIG. 4 is a block diagram showing a functional configuration of a control circuit according to a fifth embodiment (claim 6) of the present invention;

FIG. 5 is a configuration diagram schematically showing a conventional vehicle generator.

FIG. 6 is a circuit diagram showing a configuration around a general alternator.

FIG. 7 is a block diagram illustrating a functional configuration of a control circuit in FIG. 5;

FIG. 8 is a characteristic diagram showing characteristic curves of output current and output efficiency at full load of the alternator with respect to a general alternator rotation speed.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Alternator 2, 4 Armature winding 6 Field winding 7 Regulator 9 Load 10A, 10B, 10C Control circuit 12 Current crosspoint setting means 13A, 13B, 13C Comparison judgment means 14 Efficiency crosspoint setting means Co switching control signal D Field current duty F Field current control terminal If Field current Io Output current Ios Output current at full load Io1, Io2 Current characteristic curve at full load N Alternator rotation speed Nη Efficiency crosspoint rotation speed NI Current crosspoint rotation Number SCR Thyristor (selection switching means) Vo Output voltage VL Load terminal voltage Z2 Intermediate speed region η Output efficiency η1, η2 Efficiency characteristic curve at full load

Claims (6)

(57) [Claims] An alternator having an armature winding provided on a stator and a field winding provided on a rotor, and rectifying an output current from the armature winding and supplying the rectified current to a load; A regulator that controls a field current flowing through the field winding to adjust the output voltage of the alternator to a predetermined voltage; and a selection switching unit that switches the specification of the armature winding to a plurality of different winding specifications. A control circuit for operating the selection switching means in accordance with the rotation speed of the alternator, wherein the control circuit is configured to output power at full load with respect to the alternator rotation speed in each winding specification. An efficiency cross point setting means for setting an efficiency cross point rotation speed of each characteristic curve, and based on a comparison result between the alternator rotation speed and the efficiency cross point rotation speed, A vehicular generator comprising: comparison determination means for generating a switching control signal for the selection switching means so that the output efficiency of the alternator at full load is maximized. 2. The control circuit includes a current crosspoint setting unit that sets a current crosspoint rotation speed of each characteristic curve of an output current at full load with respect to the alternator rotation speed in each winding specification. The determining means compares the alternator rotation speed with the efficiency crosspoint rotation speed and the current crosspoint rotation speed, and the alternator rotation speed is an intermediate value between the efficiency crosspoint rotation speed and the current crosspoint rotation speed. When the output current of the alternator is higher than the output current of the alternator in a rotation speed region and is larger than the output current of the alternator, another winding specification having an output current characteristic at the full load that is equal to or more than the output current of the alternator is used. If so, a switching control signal for switching the specification of the armature winding to the specification of the other winding is generated. Item 4. A vehicle generator according to item 1. 3. When there are a plurality of other winding specifications, the comparing and judging means switches to a winding specification that maximizes output efficiency at full load among the other winding specifications. The vehicle generator according to claim 2, wherein 4. The method according to claim 1, wherein the comparing and judging means switches to a winding specification that maximizes an output current at the time of full load in the intermediate rotation speed region when the other winding specification does not exist. Item 4. A vehicle generator according to Item 2. 5. The method according to claim 1, wherein the comparing and judging means judges that the output current of the alternator is larger than the output current at full load when the terminal voltage of the load drops by a predetermined value or more. The vehicle generator according to any one of claims 2 to 4. 6. The method according to claim 1, wherein the comparing and judging means judges that the output current of the alternator is larger than the output current at full load when the duty of the field current indicates a maximum duty value. The vehicle generator according to any one of claims 2 to 4.