JP3250261B2 - Control device for 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 control system for a vehicular generator, and more particularly to a vehicular system capable of appropriately changing a generated voltage to effectively prevent overcharging of a battery and improving fuel efficiency of a vehicle required for power generation. The present invention relates to a control device for a power generator.

[0002]

2. Description of the Related Art In a conventional control device for a vehicle generator, a constant power generation voltage (for example, 14.5 V) which is considerably higher than a battery open terminal voltage (for example, 12.8 V) in order to quickly charge a battery. However, in this case, when the electric load is smaller than the power generation capacity, there is a possibility that the charging of the battery is promoted and the battery is brought into a fully charged state. If this state continues even after full charge, the load on the engine may be increased to deteriorate fuel economy and the battery may be overcharged.

Therefore, for example, Japanese Patent Application Laid-Open No. 59-103529
In this publication, the state of charge of the battery is predicted from the average value of the conductivity of the switching transistor (that is, the power generation rate of the generator) that flows through the field winding of the generator, and the proper charging is performed by changing the generated voltage. A control device for performing the control has been proposed.

[0004]

The control device proposed above has an excellent function of properly maintaining the state of charge of the battery. However, in order for the conductivity to indicate the state of charge of the battery well, it is relatively difficult. Because it requires a long average time,
There was a problem that responsiveness was somewhat lacking depending on the application.

The present invention has been made to solve the above-mentioned problem, and has a sufficient response to a change in an electric load and a change in a power generation capacity due to a running state. An object of the present invention is to provide a vehicular generator control device that maintains a proper state and also improves the fuel efficiency of a vehicle.

[0006]

To explain the structure of the present invention, the present invention has a stator winding and a field winding, is driven to rotate by an engine, and supplies power to an electric load and charges a battery. A generator 1, a rotation speed detecting means 2 for detecting the rotation speed of the generator 1, a generation voltage control means 3 for controlling the generated voltage of the generator 1 to a target value, Power generation rate detection means 4 for detecting the power generation rate of the vehicle and deceleration state detection means for detecting the deceleration state of the vehicle
2, 81, and when the accumulated time during which the power generation rate is equal to or more than a predetermined value under one power generation voltage target value exceeds a certain value, the power generation voltage target value is changed to a higher value, Target value changing means for returning the generation voltage target value to the original low value when the generator rotation speed is lower than the predetermined rotation speed and the power generation rate becomes lower than another predetermined value ;
When the battery is fully charged, set the low value of the target
In addition to the value near the open circuit voltage, the deceleration state of the vehicle is detected.
When the power is output, the generated voltage target value is
The control device is constituted by the target value changing means 5 set to change the value .

[0007]

In the control device having the above structure, when the power generation rate is equal to or higher than a predetermined value during the control in which the charging of the battery is suppressed by lowering the generated voltage target value, it is determined that the battery may be discharged. When the accumulated time of the state exceeds a certain value,
The target value of the power generation voltage is changed to a high value to perform quick charging. On the other hand, when the generator rotation speed is lower than the predetermined rotation speed and the power generation rate becomes lower than another predetermined value, it is determined that the charging current of the battery has decreased and the charging state has been improved. Return the generated voltage target value to the original low value. As a result, overcharging of the battery is avoided and wasteful power generation is not performed, thereby improving fuel efficiency of the vehicle.

[0008] If the lower power generation voltage target value is set close to the open terminal voltage when the battery is fully charged, the charging of the battery is suppressed and overcharging is avoided.
If the power generation capacity of the generator exceeds the load current, that is, if the power generation rate has not reached 100%, the battery is not discharged, and there is no concern about running out of the battery. In addition, the engine load is greatly reduced in normal times when rapid battery charging is not required, and fuel efficiency is greatly improved. Also, during deceleration
Only by increasing the power generation voltage target,
Kinetic energy can be effectively regenerated to the battery, and after deceleration
If the power generation voltage target value is quickly returned to the original low value, the
The charging current that flows during high speed causes the open terminal voltage of the battery to rise.
It rises for a short time. Using this, the load current can be
Is extracted, and the amount of power generated by the generator can be reduced.
The burden on vehicles has been greatly reduced, and fuel economy has been further improved.
You.

In a vehicle idling state where the number of revolutions of the generator is low, it is possible to more reliably detect the full charge of the battery.

[0010]

Embodiment 1 In FIG. 1, a generator 1 comprises an armature coil 11 serving as a stator winding, a field coil 12 serving as a field winding, and a full-wave rectifier 13. , And the power generation capacity increases or decreases according to the rotation speed. The field coil 12 is a power generation voltage control circuit 3
ON-OFF current is supplied by the switching transistor 31. The operation of the transistor 31 is controlled by the output of the comparator 32, and the comparator 32 supplies the generated voltage target value signal Vre from the D / A converter 33.
g and the feedback voltage signal VF of the battery 6 are input. As a result, the battery voltage follows the target value given to the D / A converter 33 via the I / O port 52 of the target value changing circuit 5. .

The target value changing circuit 5 includes an arithmetic unit (CPU)
51, a ROM 53, and a RAM 54. The CPU 51 receives signals from the power generation rate detection circuit 4, the throttle switch detection circuit 81, and the engine speed (ie, generator speed) detection circuit 2 by using the I / O port. 5
2 and the generated voltage target value Vr according to a procedure described later.
Change and set eg. The power generation rate detection circuit 4 receives the collector voltage of the transistor 31 and detects the conductivity, that is, the power generation rate, with a sufficiently short time average. The throttle detection switch 81 detects the fully closed state of the accelerator, and knows the idle state and the deceleration state based on the detection of the fully closed state and the detection value of the engine speed detection circuit 2. Throttle detection switch 81 and engine speed detection
The output circuit 2 constitutes a deceleration state detecting means. That is, if the engine speed is equal to or less than a predetermined value when the accelerator is fully closed, it is determined that the engine is idle.

An idle speed controller (ISC) 82 is provided, and controls the engine speed to a set speed output via the I / O port 52 in an engine idle state. Operating power is supplied from a constant voltage power supply 86 to each of the above circuits by turning on a key switch 83. An electric load 85 such as a headlamp, a blower motor, and an electric fan is connected in parallel to the battery 6 via a load switch 84.

FIG. 2 shows a processing program of the CPU 51 . This program is started, for example, by a timer interrupt every 10 ms. In step 101, the generated voltage target value Vreg
Is set to 13 V, and the counters α and β are reset to 0, respectively. The idle speed in the idle state is 6
It is set to 00 rpm. The above 13V takes into account that the open terminal voltage when the battery is fully charged is 12.8V. In this state, if the state of charge of the battery 6 is near full charge, the battery 6 is hardly charged. The power supply to the load is also reduced, the load on the generator is reduced, and fuel efficiency is improved.

In step 102, it is determined that the vehicle is being decelerated.
If the vehicle is decelerating, the target value Vreg is increased to 15 V, and the energy wastefully consumed by braking is stored in the battery 6.
(Step 103). In step 105, V
It is checked whether reg1 is 13 V, and the process proceeds to step 106 and subsequent steps.

By increasing the target value Vreg only during deceleration, braking energy during deceleration can be effectively used by the battery 6.
When the target value Vreg is immediately returned to the original low value after the deceleration, the open terminal voltage of the battery 6 increases for a short period due to the charging current flowing during the deceleration. By utilizing this, the load current is extracted from the battery 6 and the amount of power generated by the generator 1 can be reduced, so that the engine burden is further reduced and the fuel efficiency is further improved.

In step 106, it is checked whether the power generation rate (Duty) is A or more (for example, 90 to 100%). When the power generation rate is A or more, the battery 6
It is highly possible that the battery has been discharged to 85 . So step 1
At 07 and 108, the counter α is counted up. When the count value exceeds a predetermined value B, it is determined that the battery 6 needs to be charged, and Vreg1 (= Vreg step 10)
4) to 14.5 V (step 109). Thereby, quick charging of the battery 6 is started. In step 110, the counter α is reset, and the counter β
Is set to 5.

After the power generation voltage target value Vreg is increased to 14.5 V, steps 105 to 11 are performed.
Proceed to 1 to check if it is idle. This idle state is confirmed by fully closing the accelerator and lowering the engine speed. If the engine is in the idle state, the idle speed control is performed in step 112 so that the average duty within a predetermined time is 80 to 99%, and in this state, it is confirmed whether the idle speed Ne has become equal to or less than E. This E is, for example, 650 r, which is close to the lower limit value (600 rpm) of the idle speed.
pm.

If Ne ≦ E, the process proceeds to step 114 and the following.
If uty is equal to or less than F (for example, 70%), the counter β is counted up (step 115), and if it is larger than F, the counter β is counted down to 0 (step 11).
6). When the counter β becomes equal to or more than G (for example, 10) in step 117, Vreg1 is returned to 13V (step 118), and the idling speed is also reduced to 600 rpm (step 119).

That is, the above steps 114 to 117
Then, it was confirmed that the state where the power generation rate was relatively low at a sufficiently low engine speed continued for a long time. In this case, the power generation capacity was sufficient and the battery 6 was fully charged, and the power generation voltage target value was lowered to reduce the engine load. Reduce and reduce idle speed. As a result, overcharging of the battery 6 is avoided, and the fuel efficiency of the engine is further improved.

In the above embodiment, when the ISC control is not performed, steps 112, 113 and 119 are omitted. Further, steps 115 to 117 for increasing the certainty of the determination are not always necessary.

[0021]

Embodiment 2 FIG. 3 shows another embodiment of the present invention. A vehicle speed detecting circuit 9 is provided in place of the engine speed detecting circuit 2 of the above embodiment. Vehicle speed detection circuit 9 and throttle detection switch
The switch 81 constitutes a deceleration state detecting means. The other circuit configuration is the same as that of the above embodiment.

Hereinafter, the operation of the control device will be described with reference to the flowchart of FIG. In step 201, the power generation target voltage Vreg is set to 14.5 V, and the counter α is reset.

Subsequently, it is confirmed whether or not the vehicle is idling (step 202). This is confirmed by the fact that the vehicle speed is, for example, 2 km / h or less when the accelerator is fully closed. Then, in this idling state, the power generation rate of the generator 1 (Dut)
If y) is equal to or less than the predetermined value F (step 203), Vreg1 (= Vreg, see step 207) is set to 13 which is close to the open terminal voltage of the battery 6 in order to prevent overcharging.
V (step 204).

In step 205, it is confirmed whether or not the vehicle is decelerating. This is because the throttle valve is fully closed and the vehicle speed is 5
It is confirmed by Km / h or more. If the vehicle is decelerating, change Vreg to 15V in step 206,
The energy wastefully consumed by the deceleration is regenerated to the battery 6. As a result, the battery voltage increases (13 V or more) due to charge polarization after the end of the deceleration, so that the power generation of the generator 1 is hardly performed, and the fuel efficiency of the vehicle is improved.

When deceleration is completed, at step 207 Vre
g is returned to Vreg1, and steps 208 to 20
If the number of times that the duty exceeds the predetermined value A becomes 9 or more in B9, it is determined that the battery is slightly discharged and Vreg1 is set to 1
The voltage is changed to 4.5 V and the counter α is reset (steps 211 and 212). Thus, charging of the battery 6 except when the vehicle is decelerated is started.

According to this embodiment, the same effect as in the first embodiment can be obtained.

[0027]

As described above, according to the control device of the present invention, the charge state of the battery is reliably determined and the target value of the generated voltage is immediately changed, thereby preventing overcharging and discharging of the battery, and Engine fuel efficiency can also be improved.

[Brief description of the drawings]

FIG. 1 is a circuit diagram of a control device according to an embodiment of the present invention.

FIG. 2 is a program flowchart of a calculation device of a target value changing circuit.

FIG. 3 is a circuit diagram of a control device according to another embodiment of the present invention.

FIG. 4 is a program flowchart of an arithmetic unit of the target value changing circuit.

[Explanation of symbols]

1 generator 2 engine speed detection circuit (speed detection means , deceleration
State detection means ) 3 power generation voltage control circuit (power generation voltage control means) 4 power generation rate detection circuit (power generation rate detection means) 5 target value change circuit (target value change means) 6 battery 7 engine 81 throttle detection switch (deceleration state detection means) 9 ) Vehicle speed detection circuit (idle detection means , deceleration state detection
Stage )

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-60-87636 (JP, A) JP-A-60-16195 (JP, A) JP-A-61-203830 (JP, A) JP-A-60-860 35925 (JP, A) JP-A-61-203831 (JP, A) JP-A-59-103529 (JP, A) JP-A-2-111298 (JP, A) JP-A 62-53135 (JP, A) (58) Field surveyed (Int.Cl. ⁷ , DB name) H02J ^7/ 00-7/16 H02P 9/00

Claims (2)

(57) [Claims] 1. A generator having a stator winding and a field winding, which is driven to rotate by an engine, supplies power to an electric load and charges a battery, and detects a rotation speed of the generator. Rotation speed detection means, power generation voltage control means for controlling the power generation voltage of the generator to maintain the target value, power generation rate detection means for detecting the power generation rate of the generator, and detecting the deceleration state of the vehicle. A deceleration state detecting means for changing the power generation voltage target value to a higher value when the accumulated time during which the power generation rate becomes a predetermined value or more under one power generation voltage target value exceeds a certain value; A target value changing means for returning the generation voltage target value to the original low value when the generator rotation speed is lower than the predetermined rotation speed and the power generation rate becomes lower than another predetermined value; Voltage target
When the battery is fully charged,
Value when the vehicle deceleration state is detected.
Change the power generation voltage target value to a value
And a target value changing means set as described above . 2. A generator having a stator winding and a field winding, driven by an engine and supplying power to an electric load and charging a battery, and a generator for determining that the vehicle is idling. Idle detecting means for detecting,
Power generation voltage control means for controlling the power generation voltage of the generator to a target value, power generation rate detection means for detecting the power generation rate of the generator, and a deceleration state for detecting a deceleration state of the vehicle
Detecting means for changing the power generation voltage target value to a higher value when the accumulated time during which the power generation rate is equal to or higher than a predetermined value under one power generation voltage target value exceeds a certain value; Is target value changing means for returning the generated voltage target value to the original low value when the vehicle is idling and the power generation rate becomes smaller than another predetermined value.
A low value near the terminal open voltage when the battery is fully charged
And when the deceleration state of the vehicle is detected,
Change the generated voltage target value to a value equal to or higher than the high value
And a target value changing means set as described above .