JP2001173481A - Control device for vehicular generator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve vehicular accelerating performance while preventing degradation in a life of a battery by suppressing the change of battery voltage. SOLUTION: When accelerating an engine 1, under the condition that the current consumption of an electric load 4 and a battery current consumption integrating value are not more than a predetermined value, generating of an alternator 2 is cut. In the case in which the current consumption and the integrating current are comparatively high, an excessive discharge is prevented in advance without cutting electric power generation, which enables improving vehicular accelerating performance while suppressing the excessive discharging/ charging of the battery 3 to prevent degradation in a life of the battery 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicular generator control device for suppressing the load on the generator during acceleration.

[0002]

2. Description of the Related Art For example, a vehicle is equipped with various electric devices (electric loads) such as lamps, a drive motor for driving an air conditioning blower and a power device, and the electric power consumed by the electric devices is sufficient. Powered by a dischargeable battery. On the other hand, a vehicle is equipped with a generator (alternator) driven by an engine, and a battery is charged by operation control of the alternator to secure a capacity.
Then, due to the balance between the power consumption and the generated power, the battery is discharged when the power consumption exceeds the generated power, and the battery is charged when the power consumption is opposite.

[0003] In recent years, in consideration of environmental problems, various hybrid electric vehicles in which an electric motor and an engine are combined, and vehicles in which the engine is stopped when the vehicle is stopped such as at a signal stop and the engine is forcibly started when the vehicle is started have been developed. Is coming. In such automobiles, various measures have been taken to improve fuel efficiency by suppressing various loads.By minimizing the operation of the alternator when the engine is accelerating, the acceleration performance is not reduced. The engine load can be reduced to improve fuel efficiency.

Conventionally, in order to minimize the operation of the alternator during the acceleration of the engine to a necessary minimum, there has been known a technique in which the power of the alternator is cut off for a predetermined period of time during the acceleration of the engine, and then the output of the alternator is gradually increased (for example, Japanese Patent Laid-Open Publication No. H11-163873). See Japanese Unexamined Patent Publication No. Hei 5-92678). After cutting off the power generation for a predetermined time, the output of the alternator is gradually increased, whereby the load on the engine can be reduced without lowering the acceleration performance. However, such a prospective control has a problem that the power supply amount is insufficient during the power generation cut depending on the state of the electric load. In this conventional example, a means for detecting a load current is provided, but is not used for control during acceleration.

In order to minimize the operation of the alternator during acceleration of the engine, power generation is cut off when the acceleration of the engine is detected. It is known (for example, see Japanese Utility Model Publication No. 3-113908). By prohibiting the power generation cut, it is possible to reduce the load on the engine, improve the acceleration performance, and prevent the malfunction of the auxiliary equipment when the battery voltage drops.

[0006]

In the prior art, the value of the voltage is used as a condition for prohibiting power generation cut. However, the battery voltage greatly fluctuates depending on the ambient temperature and the electric load, whereas the fluctuation amount due to the increase and decrease of the battery charge amount is small, so that the charge state of the battery cannot be accurately detected by the voltage. Therefore, when the voltage threshold value is set low, the fluctuation of the battery charge amount becomes large, and a heavy load is imposed on the battery, which is one of the causes of shortening the life of the battery. It is conceivable to set the voltage value that is the threshold value high and safe,
In this case, the chance of cutting off the power generation decreases, and the load on the engine cannot be reduced, resulting in a problem that the acceleration performance decreases.

The present invention has been made in view of the above circumstances, and minimizes the operation of a generator during acceleration, secures acceleration performance, and suppresses excessive charge / discharge of a battery to shorten the life of the battery. It is an object of the present invention to provide a control device for a vehicle generator capable of suppressing the occurrence of a vehicle.

[0008]

In order to achieve the above object, according to the present invention, when the acceleration detecting means detects the acceleration state of the engine, the current consumption detected by the current consumption detecting means is reduced. The power generation of the generator is cut off by the control means on condition that it is equal to or less than a predetermined value, and the operation of the generator during acceleration is minimized to secure the acceleration performance.

In order to achieve the above object, according to the present invention, when the acceleration detecting means detects the acceleration state of the engine, the integrated value of the battery consumption current integrated by the integrating means is equal to or less than a predetermined value. Under this condition, the power generation of the generator is cut off by the control means, and the operation of the generator during acceleration is minimized to secure the acceleration performance.

At this time, as the acceleration detecting means, the throttle opening, the accelerator opening, the vehicle speed, the rate of change thereof, the intake charging efficiency and the like are used alone or in combination.

[0011]

FIG. 1 shows a schematic configuration of a vehicle provided with a control device for a vehicle generator according to an embodiment of the present invention.
FIG. 2 shows a control flowchart of the power generation control means, FIG. 3 shows a temporal change of the differential current, and FIG. 4 shows a relationship between the adjustable current and the differential current.

As shown in FIG. 1, a generator (alternator) 2 driven by a crankshaft of an engine 1 is provided. The alternator 2 issues a command from an ECU 5 according to the status of a battery 3 and an electric load 4 of various electric devices. Is controlled based on the power generation rate. The state of the alternator 2 is not shown in FR
A terminal is input to the ECU 5, and a power generation control duty signal (G terminal Duty) is output from the ECU 5 to a G terminal (not shown) according to the state of the battery 3 and the electric load 4. G terminal Duty is 0% of the minimum generated power to 10% of the maximum generated power so that the power generation rate is achieved.
Controlled between 0%.

The battery 3 is chargeable / dischargeable. The battery 3 is supplied with power from the alternator 2 to be charged, and the electric load 4 is appropriately supplied with power from the alternator 2 and the battery 3. On the path from the alternator 2 to the battery 3, a first current sensor 6 is provided as a generated current detecting means, and the generated current of the alternator 2 is detected by the first current sensor 6. In addition, a second current sensor 7 as a current consumption detecting means is provided on a path from the battery 3 to the electric load 4 on the electric load 4 side of the first current sensor 6, and the second current sensor 7 uses Current is detected. The battery 3 is provided with a voltage sensor 8 as a battery voltage detecting means.
The voltage of the battery 3 is detected by the voltage sensor 8.

In the above-described embodiment, the first current sensor 6 is provided as the generated current detecting means, and the second current sensor 7 is provided as the consumed current detecting means, so that the generated current and the consumed current are directly detected. However, it is also possible to indirectly detect the generated current and the consumed current. That is, a current sensor is provided immediately before the battery 3 and the first current sensor 6
It is also possible to calculate the current consumption from (the detection value of the first current sensor 6 -the detection value of the current sensor). In addition, a current sensor is provided immediately before the battery 3 and the second
It is also possible to provide the current sensor 7 and calculate the generated current from (the detection value of the second current sensor 7 -the detection value of the current sensor). In these cases, the detected value of the current sensor uses a positive or negative value because the direction of the current changes. Further, the alternator 2 may be a motor generator that can also be used as a starter switch or a traveling motor.

The condition of the throttle opening and the vehicle speed (not shown) are input to the ECU 5, and the vehicle (engine 1) is accelerating, decelerating, or running in a steady state based on the rate of change of the throttle opening and the vehicle speed. A function (acceleration detecting means) for determining whether or not the vehicle speed is provided is provided. As the acceleration detecting means, a throttle opening, an accelerator opening, a vehicle speed, a rate of change thereof, an intake charging efficiency, and the like can be appropriately used alone or in combination.

The detection signals of the first current sensor 6, the second current sensor 7, and the voltage sensor 8 are input to the ECU 5. EC
U5 includes power generation control means for controlling the power generation capacity of the alternator 2 so that the difference between the current consumption detected by the second current sensor 7 and the power generation current detected by the first current sensor 6 is within a predetermined value. Have been. Further, the ECU 5 is provided with integrating means for deriving a battery current consumption value obtained from the difference between the current consumption detected by the second current sensor 7 and the generated current detected by the first current sensor 6.

Further, in the power generation control means of the ECU 5, when the acceleration detection means detects the acceleration state of the engine 1, the current consumption detected by the second current sensor 7 is equal to or less than a predetermined value or integrated by the integration means. The alternator 2 is provided on condition that the integrated value of the battery consumption current is not more than a predetermined value.
It has a function to cut off power generation.

In the above-described vehicle, for example, during steady running, the alternator 2 generates power so that the difference between the current consumption detected by the second current sensor 7 and the generated current detected by the first current sensor 6 becomes zero. Is controlled. That is, G terminal Duty
Is controlled between 0% of the minimum generated power and 100% of the maximum generated power to generate power with the required power. When decelerating, G terminal
Duty is set to 100% to generate power with the maximum generated power and recover deceleration energy. In addition, if the vehicle has a function of stopping the engine when idling while the vehicle is stopped and automatically starting the engine when the vehicle starts moving, the second engine is used during the vehicle stop to prevent the engine from being restarted while the vehicle is stopped. The engine is appropriately started based on the current consumption detected by the current sensor 7 or the integrated value of the battery current consumption, the alternator 2 generates power, and the battery 3 is charged.

In the power generation control means of the ECU 5, when the current consumption detected by the second current sensor 7 while the vehicle is running is in a predetermined state (a state in which the integrated value of the current consumption and the battery current consumption is equal to or less than a predetermined value), The running state is determined. Then, the power generation of the alternator 2 is cut off during acceleration, the power generation is performed with the maximum generated power during deceleration, and the power generation corresponding to the consumed current is performed during steady running at a constant vehicle speed. This makes it possible to minimize the driving of the alternator 2 during steady running while minimizing the load while balancing the discharging and charging of the battery. In addition, acceleration can be ensured during acceleration. They also contribute to improved fuel efficiency.

The power generation control means will be described in detail with reference to FIGS.

As shown in FIG. 2, it is determined whether or not the current consumption detected by the second current sensor 7 is equal to or less than a predetermined value, or whether the integrated value of the battery current consumption integrated by the integrating means is equal to or less than a predetermined value. It is determined in S1. If it is determined in step S1 that the integrated value of the current consumption and the battery current consumption is equal to or smaller than the predetermined value, it is determined in step S2 whether or not the vehicle (engine 1) is accelerating. Or) if it is determined that the integrated value of the battery current consumption exceeds a predetermined value, then G is determined in step S3.
With the terminal Duty set to 100%, the alternator 2 generates power to fully charge the battery 3 and returns.

In step S2, it is determined whether or not the engine 1 is accelerating by determining whether the rate of change of the throttle opening is equal to or more than a predetermined value on the positive side or whether the rate of change of vehicle speed is equal to or more than the predetermined value on the positive side. It is carried out in. If it is determined in step S2 that the vehicle is accelerating, the G terminal Du is determined in step S4.
By setting ty to 0%, the power generation of the alternator 2 is cut, and the return is made. That is, the acceleration detection unit detects the acceleration state of the engine 1 on condition that the current consumption detected by the second current sensor 7 is equal to or less than a predetermined value or the integrated value of the battery current consumption integrated by the integration unit is equal to or less than the predetermined value. Is detected, the power generation of the alternator 2 is cut off.

It is also possible to add a control for cutting off the power generation of the alternator 2 for a predetermined period of time even after the acceleration determination is completed and the vehicle shifts to the steady running. The time to cut off the power generation depends on the capacity of the alternator 2, the capacity of the battery 3, the acceptability,
The vehicle is set to an optimum value based on a driving pattern assumed in the market. In this case, it is advantageous for improving fuel efficiency in a city area where acceleration and deceleration are repeated.

In the embodiment of the present invention, the power generation of the alternator 2 is cut off on condition that the current consumption of the electric load 4 (the integrated value of the battery current consumption) is equal to or less than a predetermined value when the engine 1 is accelerated. Therefore, when the current consumption (the integrated value of the battery current consumption) is relatively high, the power generation is not cut off and the excessive discharge of the battery 3 can be prevented beforehand,
Acceleration of the vehicle can be ensured while suppressing excessive charging / discharging of the battery 3 to prevent the life of the battery 3 from being shortened. It also contributes to improved fuel efficiency.

On the other hand, when it is determined in step S2 that the vehicle is not accelerating, it is determined in step S5 whether the vehicle (engine 1) is decelerating. The determination as to whether the engine 1 is decelerating is made based on whether the rate of change of the throttle opening is equal to or less than a predetermined value on the minus side or whether the rate of change of the vehicle speed is equal to or less than a predetermined value on the minus side. If it is determined in step S5 that the vehicle is decelerating, the process proceeds to step S3, the G terminal Duty is set to 100%, the alternator 2 generates power, the battery 3 is fully charged, and the process returns.

If it is determined in step S5 that the vehicle is not decelerating, it is determined that the vehicle is traveling normally in step S6 because neither acceleration nor deceleration is in progress.
The power of the alternator 2 is appropriately controlled between 0% and 100%, and the power generation corresponding to the consumed current is performed.

The power generation corresponding to the current consumption will be described.

The difference ΔI between the current consumption value detected by the second current sensor 7 and the power generation current value detected by the first current sensor 6 (current consumption value−power generation current value) ΔI is calculated, and ΔI falls within a predetermined range. G terminal Duty from 0% so that
The power of the alternator 2 is generated by controlling appropriately between 100%.
In the calculation of ΔI (n) this time, the value of the previous ΔI (n−1) is taken into account and calculated by the following equation. ΔI (n) = ΔI (n) × K + ΔI (n−1) × (1−K) where K is a coefficient less than 1.

That is, the current ΔI (n) is the current ΔI (n)
Is multiplied by K and the previous value of ΔI (n-1) by (1-
K) is added and set. For example, K
If 0.9, 90% of the current ΔI (n) value and the previous ΔI (n)
ΔI is set by adding 10% of the value of I (n-1). For this reason, when setting ΔI,
The noise of the first current sensor 6 and the second current sensor 7 is removed by reflecting the value of (n), and the power generation state of the alternator 2 does not suddenly fluctuate due to a sudden change in ΔI. After ΔI is set, ΔI is compared with a predetermined value A. A dead zone is set for the predetermined value A, and it is determined whether ΔI is equal to or more than a predetermined value + A on the plus side (in a state where current consumption is large) or ΔI is equal to or less than a predetermined value −A in the minus side (a state where current consumption is small). Is done.

When setting the current ΔI (n), the coefficient K is used to set ΔI in consideration of the value obtained by multiplying the value of the previous ΔI (n−1) by (1−K). Is used to remove noise, but it is also possible to simply use this time ΔI (n) alone.

When ΔI is equal to or more than a predetermined value + A on the plus side,
Since the current consumption is large, the previous target G terminal Duty
The current target G terminal Duty is set so that power generation can be performed at a high power generation voltage by adding a predetermined value to the current value, and the generated current value is increased to make ΔI close to zero. ΔI is a predetermined value on the minus side −
In the case of A or less, since the current consumption is small, the current target G terminal Duty is set so that power generation can be performed at a low power generation voltage by subtracting a predetermined value from the previous target G terminal Duty,
The generated current value is reduced to make ΔI close to zero. Thereby, as shown in FIG. 3, the difference (consumption current value−generation current value) ΔI between the consumption current value and the generation current value converges to zero. still,
Power generation control may be performed so that ΔI falls within a predetermined value from 0 to −A (charging side). In this case, the battery 3 is not discharged, so that the battery charge amount does not decrease.

The predetermined value (addition value, subtraction value) to be added to or subtracted from the previous target G terminal Duty is, for example, substantially in proportion to the difference ΔI between the consumed current value and the generated current value, as shown in FIG. Is set. That is, as the difference ΔI is larger, the previous target G
A predetermined value to be added to or subtracted from the terminal Duty is also set large. The predetermined value to be added to or subtracted from the target G terminal Duty is set stepwise according to the magnitude of the difference ΔI,
It is possible to provide a threshold value for I and set two or three types of values at the threshold value.

Since the power generation corresponding to the current consumption is performed in step S7, only the current that matches the current consumption is generated, so that the driving of the alternator 2 during steady running is minimized to suppress the load. Can be
Fuel efficiency can be improved by suppressing the load on the engine 1. Further, the frequency of discharging and charging of the battery 3 is reduced, so that the increase and decrease of the battery charge amount is suppressed, and it is possible to suppress a decrease in the life of the battery 3. By the way, for example, as a result of driving by simulating a traveling pattern, it has been proved that unnecessary power generation is omitted by performing power generation corresponding to current consumption, and that fuel efficiency is improved.

In the above-described embodiment, the power generation is cut off during acceleration depending on the current consumption condition. However, the current consumption condition is set in two stages, that is, a light load condition and a high load condition. It is also possible to cut off the power generation until the load, and to generate the power corresponding to the current consumption during the acceleration from the middle load to the high load even during the acceleration as in the steady state. The power generation corresponding to the current consumption (Step S7) is performed when the integrated value of the current consumption and the battery current consumption is equal to or less than a predetermined value. However, the power generation may be performed at all times during traveling.

[0035]

According to a first aspect of the present invention, when the acceleration detecting means detects the acceleration state of the engine, the current consumption detected by the current consumption detecting means is a predetermined value. Since the power generation of the generator is cut by the control means on the condition that the following conditions are satisfied, the operation of the generator during acceleration can be minimized. When the current consumption is relatively high, power generation is not cut off, so that excessive discharge and discharge of the battery can be prevented beforehand. It is possible to improve fuel efficiency.

According to a second aspect of the present invention, when the acceleration detecting means detects the acceleration state of the engine, the integrated value of the battery current consumption integrated by the integrating means is equal to or less than a predetermined value. Since the power generation of the generator is cut off by the control means on the condition that the above condition is satisfied, the operation of the generator during acceleration can be minimized. As a result, when the current consumption and the integrated value of the battery current consumption are relatively high, the power generation is not cut off, so that the excessive discharge of the battery can be prevented beforehand, and the excessive discharge and discharge of the battery is suppressed to prevent the battery life from being shortened. However, the acceleration of the vehicle can be ensured, which contributes to improved fuel efficiency.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a vehicle including a vehicular generator control device according to an embodiment of the present invention.

FIG. 2 is a control flowchart of a power generation control unit.

FIG. 3 is a graph showing a temporal change of a differential current.

FIG. 4 is a graph showing a relationship between an adjustable current and a differential current.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Engine 2 Generator (alternator) 3 Battery 4 Electric load 5 ECU 6 1st current sensor 7 2nd current sensor 8 Voltage sensor

 ──────────────────────────────────────────────────続 き Continued from the front page F term (reference)

Claims (2)

[Claims] A generator driven by an engine to supply power to a battery and an electric load; acceleration detection means for detecting an acceleration state of the engine; current consumption detection means for detecting a current consumption of the electric load; Control means for cutting off the power generation of the generator when the current consumption detected by the current consumption detection means is equal to or less than a predetermined value when the acceleration state of the engine is detected by the detection means. A control device for a vehicular generator. 2. A generator driven by an engine to supply power to a battery and an electric load; acceleration detecting means for detecting an acceleration state of the engine; current consumption detecting means for detecting a current consumption of the electric load; Current generation means for detecting the generated current generated by the machine, integrating means for integrating the difference between the consumed current and the generated current, and the above-described means when the acceleration detection means detects the acceleration state of the engine. A control unit for a vehicle generator, comprising: a control unit that cuts off the power generation of the generator when the integrated value of the battery current consumption integrated by the integration unit is equal to or less than a predetermined value.