JP4918814B2 - Air quantity control device for internal combustion engine - Google Patents

Description

  The present invention relates to an air amount control device for an internal combustion engine, and more particularly to a technique for correcting and controlling an intake air amount in accordance with a load state of an alternator.

  For example, it is necessary to drive the alternator by charging the battery by increasing the power generation voltage of the alternator when the vehicle is decelerating, charging the battery, and then covering the power consumption of the in-vehicle electric load with the electricity stored in the battery by regenerative power generation. Energy is reduced and fuel consumption is improved. In this deceleration regeneration control of the alternator, after the battery is charged by regenerative power generation, the power generation voltage of the alternator is set to a low level to place the battery in a discharged state, and the state of charge (SOC) of the battery is controlled to a predetermined set value that can be charged. Thus, the fuel consumption reduction effect, deceleration acceleration performance, etc. are kept constant. Since the load of the alternator is reduced in this battery discharge state, the intake air correction amount corresponding to the alternator load is reduced. Therefore, it is necessary to detect the load of the alternator.

In Patent Document 1, a current sensor for detecting the generated current of the alternator is provided, and the alternator load torque generated in the alternator is calculated from the alternator generated current detected by the current sensor and the engine speed, and suction is performed according to the alternator load torque. A technique for controlling the air correction amount is disclosed.
JP 2003-336532 A

However, in the configuration in which the current sensor is provided to detect the generated current of the alternator as in Patent Document 1, the number of parts increases and the cost increases, and there are problems such as layout restrictions.
The present invention has been made paying attention to the above-mentioned problems, and it is possible to correct the intake air amount appropriately according to the load change of the alternator without providing a current sensor for detecting an alternator power generation current. An object is to provide a quantity control device.

For this reason, the invention of claim 1 is an air amount control device for an internal combustion engine that corrects and controls the intake air amount in accordance with a load change during battery discharge of the alternator driven by the internal combustion engine. When there is an on-vehicle electric load that is ON, the battery air correction amount corresponding to the discharge current value is smaller than the air current correction amount for the current consumption when there is no on-vehicle electric load that is ON. Subtract the battery air correction amount to be subtracted from the electric load air correction amount corresponding to the total consumption current value of the in-vehicle electric load, and subtract the air for the alternator load. A feature is that the amount correction amount is determined.

  According to the present invention, from the air correction amount corresponding to the charge / discharge current value of the battery detected by the existing battery current sensor and the air amount correction amount corresponding to the on-vehicle electric load in which the current consumption value is in the known ON state. Since the air amount correction amount for the alternator load is determined, the air amount correction amount for the alternator load can be provided without providing a current sensor for detecting the alternator power generation current. Therefore, an increase in cost can be suppressed and the layout is not restricted.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a system configuration diagram showing a first embodiment of an air amount control device for an internal combustion engine according to the present invention.
In FIG. 1, an electronically controlled throttle valve (hereinafter referred to as an “electrically controlled throttle valve”) 3 is interposed in an intake passage 2 of the engine 1, and intake air is supplied via an actuator controlled based on the engine operating state. The flow rate is controlled. An alternator 4 that is driven by the engine 1 via a fan belt to generate electric power is controlled by a regulator 5 in response to a power generation voltage command from an ECM (engine control module) 10 incorporating a microcomputer, which will be described later. Electric power from the alternator 4 and the battery 6 is supplied to each in-vehicle electric load 8 via the in-vehicle electric load control unit 7 having a built-in microcomputer. The current sensor 9 detects the charging / discharging current of the battery 6 and inputs the detection output to the ECM 10.

The in-vehicle electric load control unit 7 is driven by power supply from the alternator 4 or the battery 6, and controls the power supply to the in-vehicle electric load 8 connected to drive and control the in-vehicle electric load 8, and the switch is turned on. The ECM 10 is notified of the in-vehicle electric load 8 in use.
The ECM 10 includes, for example, a computer and is driven by power supplied from the alternator 4 and the battery 6 to detect an engine rotation speed, a water temperature sensor that detects an engine cooling water temperature, and an air flow meter that detects an intake air flow rate. The opening degree of the electric throttle valve 3 is controlled according to the engine operating state detected based on signals from various sensors (not shown) such as a throttle sensor for detecting the throttle valve opening degree.

  Further, the ECM 10 performs fuel cut control to stop fuel injection when the engine throttle speed is decelerated at a predetermined value or more in the idle state in which the electric throttle valve 3 is substantially fully closed, and high power generation with respect to the regulator 5 during the fuel cut. The voltage command value is output and the battery 6 is charged by regenerative power generation of the alternator 4. After the regenerative power generation, a power generation voltage command value lower than the battery voltage is output, and the electric energy stored by the regenerative power generation is discharged from the battery 6. The state of charge (SOC) of the battery 6 is maintained and controlled to a constant value that can be charged by regenerative control.

  Further, the ECM 10 includes a battery air correction amount corresponding to the charge / discharge current value of the battery 6 detected by the current sensor 9 and the in-vehicle electric load 8 in the ON state notified from the in-vehicle electric load unit 7. The air correction amount for the alternator load is determined based on the air load correction amount corresponding to the electric load corresponding to the total current consumption value, and the electric throttle valve 3 is opened based on the determined air correction amount for the alternator load. The intake air amount is corrected and controlled according to the load state of the alternator 4.

Here, the generated current Ia of the alternator 4, the charge / discharge current Ib of the battery 6, and the total consumption current IR of the in-vehicle electric load are in a relationship as shown in FIG. 2.
FIG. 2A shows a case where the battery is charged, and the alternator power generation current Ia can be expressed as Ia = IR + Ib. FIG. 2B shows a case where the battery is discharged, and the alternator power generation current Ia can be expressed as Ia = IR−Ib.

  From the relationship of FIG. 2, the alternator power generation current Ia at the time of battery charging can be estimated by adding the battery charging current Ib and the total consumption current value IR of the in-vehicle electric load 8, and the alternator power generation current Ia at the time of battery discharge. Can be estimated by subtracting the battery charging current Ib from the total consumption current value IR of the in-vehicle electric load 8. The battery charge / discharge current Ib is detected by the current sensor 9, and the total current consumption value IR of the in-vehicle electric load 8 is calculated by, for example, storing the current consumption value for each in-vehicle electric load in the ECM 10 in advance. Can do. Therefore, it can be seen that the power generation current value of the alternator 4 can be estimated without providing a current sensor for detecting the power generation current of the alternator. For example, when the battery is discharged, the generated current of the alternator 4 is less by the amount of the discharge current from the battery 6, and the alternator load is reduced by that amount. This corresponds to the total current consumption value of the in-vehicle electric load 8 in the ON state in use. The air correction amount corresponding to the alternator load can be obtained by subtracting the battery air correction amount corresponding to the charge / discharge current value of the battery 6 from the air load correction amount corresponding to the electric load.

Next, the air amount correction control operation by the ECM 10 of the first embodiment will be described with reference to the flowchart of FIG.
In step 1 (indicated by S1 in the figure, the same shall apply hereinafter), it is determined whether or not the battery 6 is being discharged based on a signal from the current sensor 9. If the battery 6 is being discharged, the process proceeds to step 2.
In step 2, the battery discharge current value is read from the input signal from the current sensor 9.

In step 3, for example, the battery air correction amount corresponding to the discharge current value is set from a correspondence map of the battery discharge current value stored in advance and the battery air correction amount.
In step 4, it is determined whether or not there is an in-vehicle electric load 8 in the ON state based on the notification signal of the in-vehicle electric load unit 7. If there is an in-vehicle electric load 8 in the ON state, the determination is YES and step 5 is performed. move on.

In step 5, for example, the air correction amount of each in-vehicle electric load 8 in the ON state notified from the in-vehicle electric load unit 7 is added from the air correction amount for each in-vehicle electric load obtained and stored in advance by an experiment or the like, The total air correction amount of the in-vehicle electric load 8 in the ON state is calculated, and the air correction amount for the electric load is set.
In step 6, the battery air correction amount corresponding to the discharge current value set in step 3 is compared with the air consumption correction amount in the no-load state where there is no on-vehicle electric load 8 and the smaller one is selected. The battery air correction amount to be subtracted used in step 7 described later. Thereby, the upper limit of the battery air correction amount to be subtracted in step 7 described later is limited to the current consumption air correction amount at no load. Here, the air correction amount corresponding to the consumption current at the time of no load is an air correction amount corresponding to the consumption current value necessary for vehicle travel control by the consumption current amount of the in-vehicle electric load unit 7 or the ECM 10.

  In step 7, the air correction amount for the alternator load is calculated by subtracting the battery air correction amount in step 6 from the electric load air correction amount corresponding to the on-vehicle electric load set in step 5. The alternator load air correction amount calculated here corresponds to the generated current amount of the alternator 4, and the opening degree of the electric throttle valve 3 is corrected based on the calculated alternator load air correction amount.

On the other hand, if the determination in step 4 is NO, in step 8, the alternator load air correction amount at no load is calculated.
In step 8, the battery air correction corresponding to the discharge current value set in step 3 from the no-load consumption current air correction amount corresponding to the current consumption corresponding to the consumption current value necessary for the vehicle travel control described above. Subtract the amount to calculate the alternator load air correction amount at no load. Then, the opening degree of the electric throttle valve 3 is corrected based on the calculated alternator load air correction amount.

FIG. 4 shows a flowchart of the air amount correction control operation of the second embodiment. The hardware configuration is the same as that of the first embodiment shown in FIG.
Steps 11 and 12 are the same as steps 1 and 2 of the first embodiment, and it is determined whether or not the battery 6 is being discharged. If the battery 6 is being discharged, the discharge current value is read.
In step 13, it is determined whether or not there is an in-vehicle electric load 8 that is in the ON state based on the notification signal of the in-vehicle electric load unit 7. If YES, the process proceeds to step 14.

In step 14, for example, the current consumption value of each in-vehicle electric load in the ON state is read from the current consumption value for each in-vehicle electric load stored in advance, and the total current consumption value is set.
In step 15, the battery discharge current value read in step 12 is compared with the prestored no-load consumption current value and the smaller one is selected, and the battery discharge current value to be subtracted used in step 16 is selected. To do.

In step 16, the alternator power generation current value is calculated by subtracting the battery discharge current value set in step 15 from the total current consumption value of the in-vehicle electrical load 8 in the ON state set in step 14.
In step 17, for example, the alternator load air correction amount corresponding to the alternator power generation current value calculated in step 16 is set from a correspondence map between the alternator power generation current value and the alternator load air correction amount stored in advance. Then, the opening degree of the electric throttle valve 3 is corrected based on the set alternator load air correction amount.

On the other hand, if the determination in step 13 is NO, the air correction amount corresponding to the alternator load at no load is calculated in step 18.
In step 18, the battery discharge current value set in step 2 is subtracted from the pre-stored no-load consumption current value necessary for vehicle travel control to obtain the no-load alternator power generation current value during battery discharge. calculate. In step 17, the alternator load air correction amount is set in the same manner as described above, and the opening degree of the electric throttle valve 3 is corrected based on the set alternator load air correction amount.

  According to each of the embodiments, the air correction amount for the alternator load corresponding to the generated current value of the alternator 4 is estimated from the input signals from the existing battery current detection current sensor 9 and the in-vehicle electric load unit 7. Can do. Accordingly, it is possible to perform appropriate air correction according to the load state of the alternator 4 during battery discharge without providing a current sensor for detecting the generated current of the alternator 4, thereby reducing costs and restricting the layout. There is nothing. In addition, when the in-vehicle electric load 8 is in the ON state, the in-vehicle electric load 8 is turned on by limiting the upper limit of the battery air correction amount to be subtracted to the air correction amount corresponding to the consumption current at no load. An air correction amount equivalent to the inrush current at the time can be secured.

  When the battery is charged, the air correction amount corresponding to the battery charging current value may be added, contrary to when the battery is discharged.

The system block diagram of 1st Embodiment of the air quantity control apparatus of the internal combustion engine which concerns on this invention The figure which shows the relationship between the alternator power generation current, the battery charge / discharge current, and the current consumption of the in-vehicle electric load The flowchart explaining the air correction amount control operation of the first embodiment. Flowchart for explaining the air correction amount control operation of the second embodiment.

Explanation of symbols

1 Engine 3 Electric throttle valve 4 Alternator 5 Regulator 6 Battery 8 On-board electric load 9 Current sensor 10 ECM

Claims (5)

An air amount control device for an internal combustion engine that corrects and controls an intake air amount in accordance with a load change during battery discharge of an alternator driven by the internal combustion engine,
When there is an on-vehicle electric load during battery discharge, the battery air correction amount equivalent to the discharge current value and the current consumption air correction amount when there is no load when there is no on-vehicle electric load The smaller one is compared with the battery air correction amount to be subtracted, and the battery air correction amount to be subtracted is subtracted from the electric load air correction amount corresponding to the total consumption current value of the in-vehicle electric load, It was configured to determine the amount of air correction for the alternator load.
An air amount control device for an internal combustion engine, characterized in that: When the battery is being discharged and there is no on-vehicle electric load, the battery air correction amount equivalent to the battery discharge current value is subtracted from the air correction amount equivalent to the current consumption value required for vehicle travel control. 2. An air amount control apparatus for an internal combustion engine according to claim 1, wherein an air amount correction amount corresponding to an alternator load is determined. The amount of air correction for the alternator load converted from the battery charge / discharge current value detected by the current sensor and the amount of electric load equivalent to the total consumption current value of the on-vehicle electric load in the ON state 2. The air amount control device for an internal combustion engine according to claim 1, wherein the air amount is determined based on an air correction amount. An air amount control device for an internal combustion engine that corrects and controls an intake air amount in accordance with a load change during battery discharge of an alternator driven by the internal combustion engine,
When there is an on-vehicle electric load during battery discharge, compare the battery charge / discharge current value detected by the current sensor with the pre-stored no-load current consumption value and subtract the smaller one The battery discharge current value to be subtracted, the battery discharge current value to be subtracted is subtracted from the total current consumption value of the on-vehicle electric load in the ON state to estimate the generator current value of the alternator, and the estimated alternator power generation current value An air amount control device for an internal combustion engine, characterized in that an air amount correction amount corresponding to an alternator load is determined based on the above. When the battery is being discharged and there is no on-vehicle electrical load, the generator current value of the alternator is obtained by subtracting the battery charge / discharge current value detected by the current sensor from the current consumption value required for vehicle travel control. The air amount control device for an internal combustion engine according to claim 4 , wherein the air amount correction amount for the alternator load is determined based on the estimated alternator power generation current value.

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