JP4085767B2 - Control device for vehicle generator - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a control device for a vehicle generator driven by an internal combustion engine.
[0002]
[Prior art]
A technique for variably controlling the power generation voltage of an alternator to control the amount of power generated during traveling is known.
[0003]
In the above technique, when the electrical load increases suddenly, such as when the headlamp is lit, the generated voltage also increases correspondingly, but this also increases the rotational torque of the alternator and drives the alternator. As a result, the load on the engine was also increased, causing a problem that the engine speed dropped.
[0004]
Therefore, in order to increase the power generation amount of the generator with high responsiveness without making the engine speed unstable even when the required electric load increases suddenly, the intake air amount of the engine is set to ΔQ in accordance with the increase in the power generation amount. A method of increasing only this is disclosed (see Patent Document 1).
[0005]
[Patent Document 1]
JP 2000-341998 A [0006]
[Problems to be solved by the present invention]
However, Patent Document 1 does not mention a method for setting the correction amount ΔQ of the intake air amount of the engine.
[0007]
Therefore, an object of the present invention is to provide a power generation control device having a specific method for setting the correction amount ΔQ of the engine intake air amount when switching the power generation voltage.
[0008]
[Means for Solving the Problems]
The present invention includes a generator driven by an internal combustion engine, control means for controlling a power generation voltage of the power generator according to an electric load of an electric device mounted on a vehicle, and the power generation voltage of the power generator. Control means for controlling the intake air amount of the internal combustion engine, and when increasing the power generation voltage of the generator, the maximum generated current value at the number of rotations of the generator after voltage switching and the generated current value before voltage switching, Based on the power generation change amount current value that is the difference between the two, the torque applied to the engine is newly estimated as the power generation voltage increases, and the correction amount of the intake air amount is determined based on this torque to correct the engine intake air amount. I do.
[0009]
[Action / Effect]
According to the present invention, when the power generation voltage of the generator is increased with an increase in the electrical load of the electrical equipment , the power generation change amount current that is the difference between the maximum current value of the generator and the power generation current value before the voltage switching. Depending on the value , the engine intake air amount at that time is corrected to an appropriate intake air amount. Therefore, immediately after the power generation voltage is switched, a feeling of deceleration due to a decrease in output is observed during driving, and a decrease in idle rotation occurs during idling. The problem of, does not occur.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0011]
FIG. 1 shows the system configuration of this embodiment.
[0012]
DESCRIPTION OF SYMBOLS 1 is an engine, 2 is a generator (alternator) driven by the engine 1, 3 is a control unit (hereinafter referred to as an ECM) for controlling the engine 1, the generator 2, and a vehicle electric device, 4 is an in-vehicle electric device A battery that supplies power.
[0013]
The ECM 3 reads the state of the generator 2, the current value detected by the generated current sensor 5, and the required amount of electricity from an electric device such as a headlamp, and controls the amount of power generated by the generator 2 based on these. At the same time, the intake air amount of the engine 1 is corrected. That is, when the required amount of electricity increases, the power generation voltage of the generator is increased, and at the same time, the engine intake air amount is corrected to increase accordingly.
[0014]
FIG. 2 shows a flowchart of a control routine performed by the ECM 3 in this embodiment.
[0015]
In step S10, the power generation voltage command value calculated by the ECM 3 according to the required power amount of the electric device of the vehicle is compared with the previous power generation voltage command value. If it is larger than the previous time, the process proceeds to step S11.
[0016]
In step S11, the power generation command value is compared with a predetermined value, and if it is equal to or greater than the predetermined value, the process proceeds to step S12.
[0017]
Here, the predetermined value is a voltage value higher than the electromotive force of the battery 4, for example, a value of 13V or more.
[0018]
In step S12, the difference (power generation change current value) between the generated current value before voltage switching and the maximum generated current value at the current rotational speed of the generator 2 is calculated, and the process proceeds to step S13.
[0019]
The reason why the comparison with the maximum generated current value at the current rotation speed will be described with reference to FIGS.
[0020]
FIG. 3 is a time chart showing inflow current and voltage changes into the battery 4 before and after the generation voltage switching. From this figure, the current value flowing through the battery 4 at the moment when the voltage of the generator 2 is increased at T is shown in FIG. It can be seen that it increases instantaneously and the generated current of the generator 2 increases to near the maximum value.
[0021]
The torque for driving the generator 2 is increased by the increase in the generated current and becomes a load on the engine 1.
[0022]
Therefore, the difference in current value before and after voltage switching is captured as the amount of change in power generation and used as a parameter for correcting the intake air amount.
[0023]
FIG. 4 shows a map of the maximum generated current determined in advance for each generated voltage.
[0024]
Let point A be before the generation voltage switching (current value = IA). At this time, when the generated voltage is switched, the current value increases up to point B (current value = IB) which is the maximum generated current value. At this time, the difference between IA and IB is the power generation variation current value.
[0025]
In step S13, the power generation change current value obtained in step S12 is converted into the rotational torque of the power generator 2 using the torque map (FIG. 6) of the power generator 2 obtained in advance, and the process proceeds to step S14.
[0026]
In step S14, the rotational torque of the generator 2 obtained in step S13 is multiplied by a pulley ratio to newly convert the torque to the engine as the generated voltage increases, and the intake air amount (corrected intake air) corresponding to this torque is converted. Amount).
[0027]
If it is less than or equal to the previous power generation voltage command value in step S10, and if it is smaller than the predetermined value in S11, the process ends.
[0028]
The ECM 3 sends a throttle valve opening command corresponding to the corrected intake air amount calculated in the above steps to a throttle valve actuator (not shown), and increases the intake air amount of the engine 1.
[0029]
As described above, in this embodiment, even if the load on the engine 1 increases as the generated voltage is switched, the amount of intake air to the engine 1 according to the maximum generated current of the generator 2 at the speed after switching. Since the engine output is increased by correcting the above, problems such as a drop in engine rotation and fluctuations in idle rotation do not occur.
[0030]
In order to calculate the corrected intake air amount, it is necessary to recognize the amount of change in power generation, but the amount of change in power generation is caused by changes in vehicle current consumption and changes in the amount of charge to the battery. Since there is no correlation with the amount of change in power generation, the amount of change in power generation cannot be obtained directly from the amount of change in power generation voltage. Therefore, conventionally, when the power generation voltage is raised above a certain value, the power generation amount of the generator is maximized.
[0031]
However, in the present embodiment, the generator 2 is switched to the generation voltage by paying attention to the fact that the maximum generation current in the rotation flows through the generator 2 at the moment when the generation voltage is increased, and the generation amount rises to near the maximum generation amount at the rotation number. The amount of power generation change is calculated from the difference between the previous current value and the maximum generated current value at the number of rotations after switching.
[0032]
As a result, it is not necessary to generate power more than the required power generation as in the prior art, and it is possible to correct the intake air amount in accordance with the power generation change amount.
[0033]
In addition, when the generated voltage command value is less than the predetermined value, that is, when the engine load is hardly affected, the increase in intake air amount is not corrected, so that the engine speed does not increase and fuel consumption can be prevented from deteriorating. There is.
[0034]
Next, a second embodiment will be described with reference to FIG.
[0035]
This is basically the same as in the first embodiment, except that the generated current sensor 5 is not used in this embodiment.
[0036]
The control routine is the same as in FIG. 2, but the method for detecting the generated current value before switching used in step S12 is different.
[0037]
In the present embodiment, by using a means that can grasp the operating status of the in-vehicle electrical device without using the generated current sensor 5, for example, CAN, etc., the required amount of electricity from the operating status of each electrical device is calculated, and based on this To calculate the estimated current value.
[0038]
According to the present embodiment, in addition to the same effect as that of the first embodiment, an effect that the cost is reduced by the amount that the generated current sensor 5 is unnecessary is obtained.
[0039]
Moreover, the current value before switching the generated voltage can be obtained by providing torque detecting means for the generator 2 by detecting the Fr terminal signal or the like and converting it to a current value.
[0040]
The present invention is not limited to the above-described embodiments, and it goes without saying that various modifications can be made within the scope of the technical idea described in the claims.
[Brief description of the drawings]
FIG. 1 is a system configuration diagram of a first embodiment.
FIG. 2 is a flowchart showing a control routine of the first embodiment.
FIG. 3 is a time chart before and after switching a generated voltage.
FIG. 4 is a maximum generated current value map;
FIG. 5 is a system configuration diagram of a second embodiment.
FIG. 6 is a torque map of a generator.
[Explanation of symbols]
1 Engine 2 Generator (alternator)
3 Control unit (ECM)
4 Battery 5 Generated current sensor

Claims (4)

A generator driven by an internal combustion engine;
Voltage control means for controlling the generated voltage of the generator according to the electrical load of the electrical equipment mounted on the vehicle;
Air amount control means for controlling the intake air amount of the internal combustion engine in accordance with the power generation voltage of the generator,
When increasing the power generation voltage of the generator , based on the power generation change amount current value that is the difference between the maximum power generation current value at the number of rotations of the generator after voltage switching and the power generation current value before voltage switching, An on-vehicle generator control device characterized by newly estimating a torque applied to an engine as it increases and determining a correction amount of an intake air amount based on the torque to correct the engine intake air amount. The on-vehicle generator control device according to claim 1, wherein the power generation amount of the generator before voltage switching is detected by a generation current sensor . The on- vehicle generator control device according to claim 1, wherein the power generation amount of the generator before voltage switching is calculated based on an estimated current value obtained from an operating state of the electric load . The on-vehicle generator control device according to claim 1, wherein the power generation amount of the generator before voltage switching is calculated based on a detection value by a rotational torque detection means of the generator.

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