JPH09217636A - Control device of internal combustion engine with electric heating catalyst device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a control device of an internal combustion engine capable of restraining variation of the number of rotation of the internal combustion engine and supplying sufficient electric power at the time of heating an electric heating type catalyst device. SOLUTION: It is furnished with a generator 2 driven by an internal combustion engine 1, an intake air quantity variation means 3 to vary intake air quantity of an engine arranged in an intake system of the engine 1, an electric heating catalyst device EHC4 arranged in an exhaust system of the engine 1 as well as supplied with electric power from an electric power source consisting of a battery 8 charged by the generator 2 and the generator 2 and a produced energy variation means 7 to vary generated energy of the generator 2 by varying field quantity of the generator 2, the intake air quantity is increased by the intake air quantity variation means 3, and the produced energy of the generator 2 is increased by the produced energy variation means 7 while the EHC4 is made in an active state. Additionally, increasing start of the field quantity of the generator 2 is delayed by specified time later than increasing start of the intake air quantity, or increase of the intake air quantity and increase of the field quantity of the generator 2 are gradually carried out.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for an internal combustion engine having an electrically heated catalyst device.

[0002]

2. Description of the Related Art There is known a technique in which an exhaust gas purification catalyst is provided in an exhaust passage of an internal combustion engine to purify harmful substances such as HC, CO and NOx in exhaust gas. In general, this exhaust purification catalyst does not exhibit its exhaust purification capability unless it reaches an activation temperature or higher. Normally, the exhaust purification catalyst is heated by the exhaust gas of the internal combustion engine and gradually rises in temperature to reach the activation temperature.However, when the engine is cold started, the exhaust temperature is low and the exhaust purification catalyst reaches the activation temperature. Takes time. Therefore, exhaust gas purification is insufficient until the exhaust gas temperature rises after the cold start of the engine.

Therefore, in order to promptly purify the exhaust gas of the internal combustion engine, the catalyst carrier is heated by an electric heater or the like at the time of starting the engine to raise the catalyst temperature to the activation temperature in a short time ( EHC; Electr
ically Heated Catalysts) have been proposed. An example of this type of electrically heated catalyst device is, for example, Japanese Unexamined Patent Publication No.
There is one disclosed in Japanese Patent No. 179939. This electric heating type catalyst device is configured so that electric power is supplied from the battery to the electric heater, but since a large amount of electric power is consumed when the electric heater operates, a voltage drop occurs in the battery which is the power source. Occurs. In order to suppress this voltage drop,
Japanese Unexamined Patent Publication No. 6-101459 provides an intake system when the idling operation state is detected and the heating operation of the electrically heated catalyst device is detected, and the heating operation of the electrically heated catalyst device is detected during idling operation. Also disclosed is a technique for increasing the intake air amount by means of an intake air amount adjusting means such as an electronic throttle or an idling speed control (ISC). According to this technique, when the intake air amount is increased, the fuel injection amount is also increased according to the intake air amount by the air-fuel ratio control of the internal combustion engine, the output (torque) of the internal combustion engine is increased, and the rotation speed is also increased. To rise.
Then, as the rotational speed of the internal combustion engine increases, the amount of power generation of the generator driven by the internal combustion engine also increases,
This increase in the amount of power generation will compensate for the battery voltage drop. Note that the above-described technology discloses only a configuration in which electric power is supplied from the battery to the electric heater, but even in the case of directly supplying electric power from the generator to the electric heater, the electric power consumption of the electric heater is large. Therefore, when heating the electrically heated catalyst device, it is conceivable to increase the rotation speed of the internal combustion engine in order to increase the power generation amount of the generator, as in the above-described technique.

[0004]

However, the above-mentioned technique has a problem in that the driver feels uncomfortable because the engine speed of the internal combustion engine naturally becomes higher than the normal engine speed. In particular, the electric heating type catalyst device is usually heated by the electric heater when the engine is usually started, that is, in the idling state, and the driver easily feels a slight difference in the number of revolutions. In order to make the above problem clearer, a detailed description will be given below with reference to the drawings.

FIG. 15 is a schematic configuration diagram of a control device for an internal combustion engine having an electrically heated catalyst device according to the prior art. A conventional control device shown in FIG. 15 includes a generator 2 driven by an internal combustion engine (hereinafter simply referred to as engine) 1, and an engine 1.
An intake air amount varying means 3 arranged in the intake system for varying the intake air amount of the engine 1, and an electrically heated catalyst device 4 arranged in the exhaust system of the engine 1 and supplied with electric power from the generator 2. Have. Further, a three-way catalyst 4a that is heated by the exhaust gas from the engine 1 without being electrically heated is provided downstream of the electrically heated catalyst device 4 in the exhaust system of the engine 1. As the intake air amount varying means 3, an electronic throttle for rotating the stepping motor forward or backward by operating the accelerator pedal or controlling the control device 5 to increase or decrease the intake air amount, an idling speed control ISC device described later, or the like is used.
The control device 5 is composed of, for example, an electronic control unit ECU as a microcomputer system including a CPU, a ROM, a RAM, an input interface circuit, an output interface circuit, and a bus line connecting these components so that they can communicate with each other.

Further, in the control apparatus for an internal combustion engine according to the above-mentioned prior art, for example, the engine speed calculated from the detected temperature of the water temperature sensor (not shown) of the engine 1 or the output signal of the crank angle sensor (not shown) is used. Based on the EHC active state determination means 6 for determining whether or not the electrically heated catalyst device 4 is in the active state, and a normal regulator for varying the power generation amount of the power generator 2 by varying the field amount of the power generator 2. The power generation amount varying means 7 and the EHC active state determination means 6 supply electric power from the generator 2 to the electrically heated catalyst device 4 only when the electrically heated catalyst device 4 determines that the electrically heated catalyst device 4 is inactive. And a power supply switching means 19 for switching. Electric power is constantly supplied to the battery 8 from the generator 2. Further, the battery 8 supplies electric power to the control unit ECU 5, the power generation amount varying means 7, and other loads necessary for the vehicle. Further, the power generation amount varying means 7 increases and corrects the field current of the generator 2 so as to compensate for the voltage drop of the battery due to load fluctuation and the like. The correction of the field current is usually performed by duty-controlling the energization time of the field current.

In the control apparatus for an internal combustion engine according to the above-mentioned prior art, when the EHC active state determining means 6 determines that the electrically heated catalyst device 4 is inactive, the intake air amount varying means 3 intake air. Increase the amount.
However, since the generator 2 also supplies the power to the battery 8, the field current of the generator 2 is suppressed so that the battery 8 is not destroyed, and the output voltage of the generator 2 is suppressed to about 15 V or less. It is controlled by the quantity varying means 7. On the other hand, when the EHC active state determination means 6 determines that the electrically heated catalyst device 4 is in the active state, the generator 2
Power supply to the electrically heated catalyst device 4 is cut off by the power supply switching means 9. The engine speed control by the control device for an internal combustion engine according to the above-described conventional technique shown in FIG. 15 will be described below with reference to a time chart.

FIG. 16 is a time chart showing engine speed control according to the prior art. In the description of this figure, the generator 2 is the alternator 2 and the intake air amount varying means 3 is I.
SC3, electric heating type catalyst device 4 EHC4, control device 5
Will be referred to as ECU 5, EHC active state determination means 6 as activity determination means 6, power generation amount varying means 7 as regulator 7, and power supply switching means 19 as control relay 19. Further, in the figure, the horizontal axis represents time, and shows the case where the EHC4 is in the inactive state between the times t ₁ and t ₁₀ . The activity determining means 6 is time t
_{In 1} it was detected that the water temperature had dropped below 35 ° C, and EC
U5 switches the control relay 19 so as to supply the electric power of the alternator 2 to both the battery 8 and the electrically heated catalyst device 4 and at the same time opens the throttle valve (described later) of the ISC 3 to open the intake air amount (hereinafter referred to as the intake amount). ) Is increased by a predetermined amount. Then, the intake amount of the engine 1 increases from time t ₁ to t ₂ , the fuel injection amount increases by the air-fuel ratio control according to the increased intake amount, the generated torque of the engine 1 increases, and the engine speed NE Becomes higher and EH from time t ₁
Since the power is supplied to C4, the load of the battery 8 becomes large and the voltage of the battery 8 drops. At time t ₂ , the regulator 7 increases the field current to compensate for the voltage drop of the battery 8. As a result, the voltage of the battery 8 returns to the original voltage from time t ₂ to time t ₃ . The engine speed N
E also decreases because the load on the engine 1 increases due to the increase in the power generation amount of the alternator ₂ from time t ₂ to time t ₃ , but the engine speed at time t ₃ becomes higher than that at time t ₁ .

After that, the activity determining means 6 detects that the water temperature exceeds 35 ° C. at time t ₁₀ , and the ECU 5 controls the control relay 19 so as to cut off the power supply from the alternator 2 to the electrically heated catalyst device 4. And ISC3 at the same time
And the intake air amount is reduced by a predetermined amount. Then time t
The intake air amount of the engine 1 decreases from ₁₀ to t _11, and the fuel injection amount decreases by the air-fuel ratio control according to the decreased intake air amount.
The torque generated by the engine 1 decreases, the engine speed NE decreases, and electric power is no longer supplied to the EHC 4 from time t _10, so the load on the battery 8 decreases and the voltage of the battery 8 increases. At time t ₁₂ , the regulator 7 reduces the field current to compensate for the voltage increase of the battery 8. As a result, the voltage of the battery 8 returns to the original voltage from time t ₁₁ to time t ₁₂ . Further, the engine speed NE also increases from the time t ₁₁ to the time t ₁₂ because the load on the engine 1 is reduced by the amount of decrease in the power generation amount of the alternator 2 and returns to the original engine speed. That is, it can be seen that the engine speed during idling becomes higher than usual between times t ₁ and t ₁₂ . Therefore, the present invention solves the above problems and has an internal combustion engine having an electrically heated catalyst device capable of supplying sufficient power while suppressing fluctuations in the rotational speed of the internal combustion engine when heating the electrically heated catalyst device. It is an object of the present invention to provide a control device of.

[0010]

According to a first aspect of the present invention, there is provided a control device for an internal combustion engine having an electrically heated catalyst device according to claim 1, wherein the electric power generator is driven by the internal combustion engine and is charged by the generator. A battery, an engine speed varying means for varying the engine speed of the internal combustion engine, and an electrically heated catalyst supplied with power from the generator or the battery,
In a control device for an internal combustion engine having an electric heating type catalyst device including a power generation amount varying means for varying the power generation amount of the generator, while supplying electric power to the electric heating type catalyst,
The engine speed changing means increases the engine speed, and the power generation amount changing means increases the amount of power generated by the generator. A control device for an internal combustion engine having the electrically heated catalyst device according to claim 1,
While supplying electric power to the electrically heated catalyst to activate the electrically heated catalyst, the engine speed varying means increases the engine speed and the power generation varying means increases the power generation amount by the generator. By so doing, the electrically heated catalyst is activated early and the load on the engine is increased. Then, in order to prevent the engine speed from decreasing, as engine speed varying means, for example, by varying the intake air amount, the intake air amount is increased, the fuel injection amount is increased, and the engine torque is increased. As a result, the engine speed is kept constant.

According to a second aspect of the present invention, there is provided a control device for an internal combustion engine having an electrically heated catalyst device, wherein, in addition to the configuration according to the first aspect, the power generation amount varying means varies the field amount of the generator. The power generation amount of the generator is varied, and the control device of the internal combustion engine is configured to delay the start of increasing the field amount of the generator by a predetermined time from the start of increasing the intake air amount of the internal combustion engine. In the control device for the internal combustion engine having the electrically heated catalyst device according to the second aspect, the intake air increased after the actuator for increasing the intake air amount of the engine is operated is supplied to the cylinder of the engine. Since there is a time delay before the increase in the engine generated torque due to the increased intake air and the fuel injection amount that increases accordingly, the increase in the field amount of the generator must be increased. Delayed than the start,
After the torque generated by the engine is increased, the field amount of the generator is increased to increase the load on the engine, so that the electrically heated catalyst can be activated early without substantially reducing the engine speed. it can.

In a control device for an internal combustion engine having an electrically heated catalyst device according to a third aspect, in addition to the configuration according to the first or second aspect, the power generation amount varying means varies the field amount of the generator. As a result, the power generation amount of the generator is varied, and the control device of the internal combustion engine is configured to gradually increase the intake air amount of the internal combustion engine and the field amount of the generator. A control device for an internal combustion engine having the electrically heated catalyst device according to claim 3,
In this way, the intake air amount of the engine is gradually increased and the fuel injection amount is gradually increased to gradually increase the torque generated by the engine, and the field amount of the generator is increased in accordance with the increase in the torque generated by the engine. Since the load of the engine is gradually increased by gradually increasing it, the electrically heated catalyst can be activated early without changing the rotational speed of the engine.

[0013]

FIG. 1 is a basic configuration diagram of an embodiment of the present invention. Compared with the configuration of the control device for the internal combustion engine having the electrically heated catalyst device according to the related art shown in FIG. 15, the configuration of the control device for the internal combustion engine having the electrically heated catalyst device according to the embodiment of the present invention is the power supply switching. The control of the means 9 and the control unit ECU 4, and the output of the generator 2 is transmitted through the power supply switching means 9 to the battery 8 or the electrically heated catalyst device 4.
However, the other configurations are substantially the same. The power supply switching means 9 of the present embodiment supplies electric power from the generator 2 to the electrically heated catalyst device 4 when the electrically heated catalyst device 4 is in the inactive state, and generates power when the electrically heated catalyst device 4 is in the active state. A power supply is connected from the machine 2 to the battery 8. Further, an idling speed control ISC device, which will be described later, is adopted as the intake air amount varying means 3 of this embodiment. In this embodiment, the engine speed changing means for changing the engine speed of the internal combustion engine 1 according to the present invention is executed by changing the intake air amount (intake air amount) by the intake air amount changing means 3.

In the control device 5 for an internal combustion engine according to the embodiment of the present invention, when the EHC active state determination means 6 determines that the electrically heated catalyst device 4 is inactive, the intake air amount varying means 3 determines. The amount of intake air is increased, and the amount of power generation of the power generator 2 is increased by the power generation amount varying means 7. At this time, the generator 2 does not supply power to the battery 8, so that the generator 2 is not damaged.
It is not necessary to suppress the field current of the generator 2 to suppress the output voltage of the generator 2 to about 15 V or less, and the output voltage is, for example, 20 to 30 V.
Can be as high as As a result, the electrically heated catalyst device 4 can be activated early. On the other hand, EHC
When the active state determination means 6 determines that the electrically heated catalyst device 4 is in the active state, the power supply switching means 9
The electric power supplied by the generator 2 is supplied by the electrically heated catalyst device 4
From the battery 8 to the electrically heated catalyst device 4
Since it is not necessary to heat the generator early, the output voltage of the generator 2 is adjusted to about 15 by adjusting the field current by the power generation amount varying means 7.
It can be suppressed to V or less.

The above-mentioned ISC device will be briefly described below. FIG. 2 is a diagram showing a schematic configuration of the ISC device. In FIG. 2, 21 is the engine, 22 is the engine 2
1 is an intake passage, 23 is a throttle valve arranged in the intake passage, 24 is an air flow meter, and 25 is a surge tank. Reference numeral 26 is a bypass passage that bypasses the throttle valve 23 and connects the intake passage between the throttle valve 23 and the air flow meter 24 and the surge tank 25. An ISC valve 28 driven by an actuator 27 such as a stepping motor is provided in the bypass passage 26. The actuator 27 of the ISC valve 28 is an EC
It is connected to the output interface circuit of U5, and E
By controlling the opening of the ISC valve 28 via the actuator 27 by the control signal from the CU 5, the engine intake air amount is controlled independently of the throttle valve 23.

Next, four engine speed controls executed in the control device for the internal combustion engine having the electrically heated catalyst device according to the embodiment of the present invention shown in FIG. 1 will be described below with reference to a time chart and a flow chart.

FIGS. 3, 4, 5 and 6 relate to the first engine speed control after the engine is started, FIG. 3 is a time chart, FIG. 4 is a flowchart of processing executed in the main routine, FIG. 5 and FIG. 6 is a flowchart of the processing executed by the 32 msec interrupt routine. In the time charts after FIG. 3, the horizontal axis represents time. Further, in the description after FIG. 3, the generator 2 is the alternator 2, and the intake air amount varying means 3
Is the ISC 3, the electrically heated catalyst device 4 is the EHC 4, the control device 5 is the ECU 5, the EHC active state determination means 6 is the activity determination means 6, the power generation amount varying means 7 is the regulator 7, and the power supply switching means 9 is the control relay 9. . Also, in the flowcharts of FIG. 4 and subsequent figures, the numbers following S indicate step numbers. Hereinafter, description will be given with reference to FIG. 1, FIG. 3, FIG. 4, FIG. 5 and FIG.

The main routine is executed every several msec, and in step S1 in the flowchart of the main routine, the EHC total operating time counter CEHC is set to 25 sec and EHC is set to E.
Set the HC energization start time counter CEHCON to 10 and EH
The C energization end time counter CEHCOF is set to 10. In step S2, it is determined whether or not the operating condition of the EHC 6 is satisfied by setting the engine speed NE to NE ≧ 400RP.
M and engine water temperature THW is -10 ° C ≤ THW ≤ 35.
Judgment is made depending on whether or not ° C is satisfied, and the judgment result is Y
If ES, go to step S3. If NO, go to step S4.
Proceed to. In step S3, the EHC energization start flag X
Set EHCST and increase IS of valve opening amount IS
Set CSTEP to 5 steps. In step S4, XEHCST is reset. These setting data are used in the interrupt routine. Next, after the processes of steps S3 and S4, the process shifts to the process of the main routine of the engine 1 other than the engine speed control. Next, the interrupt routine will be described.

In step S11 in the flowchart of the 32 msec interrupt routine, the target opening degree of ISC is calculated. The target opening degree of the ISC valve is usually calculated based on the current water temperature THW of the engine 1 and the rotational speed NE. In step S12 to S17, whether EHC operating condition is satisfied is determined in the flags XEHCST, from the time of establishment (time t ₁ in the time chart) the counter value of CEHC for each processing cycle of the interrupt routine The cycle 32
The value is decremented by msec, and the ISC target opening is added by 5 steps at time t ₁ when the EHC operating condition is satisfied, and the valve is opened. The steps S12 to S17 will be individually described below.

In step S12, it is determined whether or not the EHC energization start flag XEHCST is reset, and if the result of the determination is YES, the process proceeds to step S14.
If NO, the process proceeds to step S13. In step S13, it is determined whether or not the EHC total operating time counter CEHC is 0, and if the result of the determination is YES, the process proceeds to step S16.
If NO, the process proceeds to step S15. In step S14, the control of the field current to the alternator 2 is set to the field current suppression control when power is normally supplied to the battery 8, and then the control relay 9 is switched from the EHC 4 side to the battery 8 side, and this interrupt routine is executed. To finish. In step S15, CEHC (sec) -32 (msec) is calculated, and the calculation result is set as a new CEHC. However, it is set to 0 when the calculation result becomes negative. In step S16, step S13
Since it is determined that 25 seconds have elapsed since the execution of this interrupt routine was started, the XEHCST flag is reset to 0, the process proceeds to step S14, and the process of step S14 is executed.
This is when EHC4 is continuously energized for 25 seconds.
This is because it has been experimentally confirmed to be activated. In step S17, the ISCS set in step S3 is set to the target opening of the ISC valve calculated in step S11.
TEP, that is, 5 steps are added to set a new target opening of the ISC valve and the ISC valve is opened to that opening. This time corresponds to time t ₁ in the time chart.

Next, in steps S18 to S20, the counter CEHCO is reached when the current ISC opening reaches the target opening.
To verify that the 320msec has elapsed from the time t ₁ by N. The steps S18 to S20 will be individually described below. In step S18, the current ISC valve opening is ISC.
Whether or not it matches the target opening is determined, and the determination result is Y.
If ES, go to step S19. If NO, go to step S1.
Proceed to 4. In step S19, it is determined whether or not CEHCON = 0, that is, whether or not this interrupt processing routine has been executed 10 times (320 msec has elapsed), and if the determination result is YES, the process proceeds to step S21, and if NO. Advances to step S20. In step S20, the EHC energization start time counter CEHCON-1 is calculated, the calculation result is set as a new CEHCON, and the process proceeds to step S14.

The time from time t ₁ to confirm whether or not 20 seconds has elapsed in step S21, the confirmation result when NO, that has elapsed from the time t ₁ 20 seconds from the time t ₁ from 320msec elapsed time t ₂ up to t ₃ proceeds to step S22, when the check result is YES, that is, the time t ₃ when the time t ₁ has elapsed 20 seconds step S2
The ISC target opening five step partial closing at 3, yet at time t ₄ when passed 320msec from the time t ₃ executes step S14 described earlier. That is, after setting the control for suppressing the field current to the alternator 2 in step S14, the control relay 9 is switched from the EHC 4 side to the battery 8 side. The steps S21 to S27 will be individually described below. In step S21, the EHC total operating time counter C
It is determined whether or not EHC is CEHC <5 (sec). If the determination result is YES, the process proceeds to step S23, and if NO, the process proceeds to step S22. The establishment of CEHC <5 (sec) means that 20 seconds have elapsed from time t ₁ .

In step S22, after the control relay 9 is switched from the battery 8 side to the EHC 4 side, the control of the field current to the alternator 2 is canceled when the normal power supply to the battery 8 is released. The number is increased and this interrupt routine is ended. In step S22, the control relay 9 is switched from the battery 8 side to the EHC 4 side. This time corresponds to time t ₂ in the time chart in which 320 msec has elapsed from time t ₁ . Thus, at time t ₁ , ISC
After 320 msec has elapsed since the valve opening amount of 3 increased, the engine 1
The amount of intake air supplied to each cylinder increases by an amount corresponding to an increase in the valve opening amount of ISC3, and the fuel injection amount is increased by the air-fuel ratio control in accordance with the increased amount of intake air. The injection amount is supplied into the cylinder of the engine 1, and the torque generated by the engine 1 increases. Next, at time t ₂ , electric power is supplied from the alternator 2 to the EHC 4 and the regulator 7
Therefore, even if the field current of the alternator 2 is increased and the load of the engine 1 is increased, the generated torque of the engine 1 is increased due to the increase of the valve opening amount of the ISC valve.
Is never high. However, in reality, the amount of intake air in the cylinder of the engine 1 gradually increases from time t ₁ to t _2, and the engine speed NE also gradually increases accordingly, and the power generation amount of the alternator 2 rapidly increases at time t _2. Since the load on the engine 1 is increased, the engine speed NE is slightly decreased although it does not make the driver feel uncomfortable. The time t ₂ also changes to lose weight side calculation result of the target opening of the ISC in step S11 in accordance with the amount that the engine speed NE is lowered.

In step S23, calculation in step S11
From the target opening of the ISC valve that was set in step S3
SCSTEP, that is, a new IS by subtracting 5 steps
Set the target opening of the C valve and set the ISC valve to that opening.
Is closed. This time is time t in the time chart_Three
Is equivalent to At step S24, the current ISC valve opening
Discriminates whether or not is equal to the ISC target opening
If the result is YES, go to step S25.
Go to step S22. In step S25, CEHCOF =
0 or not, that is, this interrupt processing routine is time t_ThreeFrom
Was it executed 10 times (time t_Three320msec have passed since
Or not), and if the result of the determination is YES, the
If not, go to step S26.
No. In step S26, the EHC energization end time counter C
EHCOF-1 is calculated and the calculation result is used as a new CEHC.
It is set to OF, and the process proceeds to step S22. That is, time t _ThreeOr
Time t when 320 msec have passed_FourThe steps described above
The process of step S14 is executed. In step 27, XEHC
ST is reset to 0 and the process proceeds to step S14.

Thus, at time t_ThreeThe opening amount of ISC3 is
Supply in the cylinder of engine 1 after 32msec has passed from the decrease
The amount of intake air is the amount corresponding to the reduction of the valve opening amount of ISC3
The air-fuel ratio control is performed according to the reduced intake air amount.
The fuel injection amount is reduced and the intake air amount and fuel injection amount
Is supplied to the cylinder of engine 1, and the torque generated by engine 1 is reduced.
Less. Then time t_FourFrom alternator 2 to EHC4
Power supply to the battery 8 and the power supply to the battery 8 are stopped.
Supply is started, and the field current suppression control by the regulator 7
When set to ON, the field current of the alternator 2 decreases and the engine 1
Even if the load on the
Since the torque generated by function 1 is decreasing, the rotational speed of engine 1
NE will not be lowered. However, in reality, time t
_ThreeTo t _FourUntil the intake air amount in the cylinder of engine 1 gradually increases
Decrease and engine speed NE gradually decreases accordingly
And time t_FourThe power generation of the alternator 2 suddenly decreases
As a result, the load on the engine 1 is reduced and the engine speed NE is
It does not cause discomfort to the transferee, but it rises a little
You. Time t_FourIn addition, the engine speed NE has increased
According to the calculation result of the target opening degree of ISC in step S11
Also changes to the increase side and returns to the original valve opening.

7, FIG. 8, FIG. 9 and FIG. 10 relate to the second engine speed control after the engine is started, FIG. 7 is a time chart, FIG. 8 is a flow chart of processing executed in the main routine, FIG. 9 and FIG. Reference numeral 10 is a flowchart of the processing executed by the 32 msec interrupt routine. The flowchart shown in FIG. 8 differs from the flowchart shown in FIG. 4 only in steps S1 and S3. In step S1 in the flowchart of FIG. 8, the EHC total operating time counter CEHC is set to 2
The EHC energization start time counter CEHCON is set to 10 and the EHC energization end time counter CEHCOF is set to 1 in 5 seconds.
Set the alternator field transistor on-time counter TTRON to 0 msec. The set value of this counter indicates the energization time of the field current of the alternator energized at a duty cycle of 20 msec. In step S3, ISC
The valve opening amount ISCSTEP of is set to one step.

Steps S12 to S16 in the flowchart shown in FIG. 9 are the same as those in the flowchart shown in FIG. Step S11 shown in FIG. 5 is deleted in FIG. In steps S12 to S17, it is determined whether or not the EHC operating condition is satisfied by XEHCS.
It is determined by the flag of T, and when it is satisfied (time t ₁ in the time chart), the counter value of CEHC is subtracted by 32 msec for each processing cycle of this interrupt routine, and EH
From the time t ₁ when the C operating condition is established, the ISC target opening is incremented by one step every 32 msec of the cycle to open the valve.
Specifically, the pulse signal of the stepping motor that drives the ISC valve is input one pulse at a time from t ₁ every 32 msec which is the processing cycle of the interrupt routine, and the valve opening is started at time t 1.
Finish at ₃ . On the other hand, the control relay 7 is gradually switched from the battery 8 side to the EHC 4 side at time t ₂ when 320 msec has elapsed from time t ₁ , that is, the duty cycle is 20 msec.
The field current whose duty is controlled by
Each ec is added every 32 msec which is the processing cycle of the interrupt routine to start increasing the field current, and ends at time t ₄ when the preset upper limit duty ratio is reached. Here, FIG.
In step S20 in the flowchart shown in FIG.
It is understood that the upper limit duty ratio is set to 100% since the time t ₄ is determined by determining ON = 20 msec. When reaching the upper limit of 100% duty ratio to be the time t ₄ 0% lower limit duty ratio if at time t _2, the
From time t ₂ to time t ₄ (0.4 / 20) × 32 (ms
ec) = 1.6 seconds.

After that, in steps S22 to S27,
22.5 after execution of this interrupt routine is started in step S22
It is determined that seconds have passed, and the time t_FiveFrom this interrupt processing
The ISC target opening is set to 1 in step S24 every cycle of 32 msec.
At the time t_FiveFrom 320ms
Time t at which it is confirmed in step S25 that ec has elapsed ₆
To step S27 are executed in this interrupt processing cycle of 32 msec
The field current is gradually reduced by
20 msec duty control of field current energization time
32 msec which is the processing cycle of the interrupt routine every 0.4 msec
Start subtracting each time to start decreasing the field current, and
Time t when the ratio is reached₈To end. Below step S
17 to S27 will be described individually.

Step S in the flowchart of FIG.
In 17, the control relay 9 is moved from the battery 8 side to the EHC 4 side.
After switching, control the field current to the alternator 2
Cancel the control when supplying power to the normal battery 8.
The field current is increased and the process proceeds to step S18. Figure 10
In step S18 of the row chart, EHC total operation
Whether the time counter CEHC is CEHC> 22.5 (sec)
If the result is YES, step
If NO in step S18A, the flow advances to step S22. CE
When HC> 22.5 (sec) is satisfied, execution of this interrupt routine is started.
It means that 2.5 seconds have passed from the beginning. Step
In 18A, the alternator field transistor on-time
Unta TTRON is determined whether it is 15msec or more, and
When the determination result is YES, that is, t₁To t_ThreeUntil
If the determination result is NO in step S19,
No t _ThreeAfter the elapse, the process proceeds to step S20. Where t
_ThreeIs t_TwoIt is the time when 1.2 seconds have passed from. Steps
In S19, the target opening of the ISC valve is set in step S3.
ISCSTEP, that is, adding 1 step
Set the target opening of the ISC valve and set IS
Open the C valve. This time is the time in the time chart
t₁Is equivalent to

In step S20, it is determined whether or not the alternator field transistor on-time counter TTRON is 20 msec. If the determination result is YES, this interrupt routine is terminated, and if NO, the process proceeds to step S21. In step S21, TTRON = TTRON + 0.4 (mse
c) is calculated and this interrupt routine ends.

At this step S17, the control relay 9 is closed.
The side is switched from the side 8 to the side EHC 4. This time is
Time t₁In the time chart after 320 msec
Time t_TwoIs equivalent to Thus time t₁Of ISC3
After 320msec has elapsed since the valve opening amount started to increase gradually,
The intake amount supplied to the cylinder of the engine 1 is the valve opening amount of ISC3.
Gradually increases by an amount corresponding to the increase in
The fuel injection amount is increased by air-fuel ratio control according to the air volume,
These intake air amount and fuel injection amount are supplied to the cylinder of the engine 1.
As a result, the torque generated by the engine 1 gradually increases. Then time
t_TwoFrom the alternator 2 to the EHC 4
Both regulators 7 use the field current of the alternator 2
Gradually increase the load of the engine 1 gradually
Also, the opening amount of the ISC valve gradually increases and the engine 1
Since the torque gradually increases, the engine speed NE of the engine 1 becomes high.
Never. Thus time t₁To t_ThreeIn between
The amount of intake air in the cylinder of engine 1 gradually increases, and
Accordingly, the engine speed NE also gradually increases, and at time t₁Or
T_ThreeTime t which is 320 msec later than _Two
To t_FourUntil then, the amount of power generated by the alternator 2 gradually increases.
As the load increases, the engine 1 load gradually increases and the engine speed increases.
The NE will not make the driver feel uncomfortable.

In step S22, it is determined whether or not the EHC total operating time counter CEHC is CEHC <2.5 (sec). If the result of the determination is YES, the process proceeds to step S23.
If NO, this interrupt routine is ended. CEHC <
The establishment of 2.5 (sec) means that 22.5 seconds have elapsed since the execution of this interrupt routine was started. In step S23, the alternator field transistor on-time counter TT
It is determined whether RON is 0 msec, and the determination result is YES.
If this is the case, this interrupt routine is terminated and the result of the determination is NO.
If so, the process proceeds to step S23A. Step S23A in TTRON it is determined whether or not 5msec or more, when the determination result is YES, that is, from t ₅ to t ₇ proceeds to step S24, when the determination result is NO, i.e., t ₇ after step Proceed to S5. Where t ₇ is t ₆
It is the time when 1.2 seconds have passed from. In step S24, the ISC valve target opening degree set in step S3 is set to ISC.
STEP, that is, one step is subtracted to set a new target opening of the ISC valve, and the ISC valve is closed at that opening. This time corresponds to time t ₅ in the time chart. That is, the ISC 3 is gradually closed from time t ₅ . Step S25, CEHCOF = 0 whether, i.e. the interrupt handling routine (or not 320msec elapses from the time t ₅₎ or run from the time t ₅ 10 times to determine whether, when the determination result is NO The process proceeds to step S26, and if YES, the process proceeds to step S27. That is, the field of the alternator is gradually reduced from time t _{6 when} 320 msec has elapsed from time t ₅ . In step S26, the EHC energization end time counter CEHCOF-1 is calculated, the calculation result is set as new CEHCOF, and this interrupt routine is ended. In step S27, TTRON = TTRON-
0.4 (msec) is calculated, and this interrupt routine is ended.

In this way, at the time t ₆ after 32 msec has elapsed since the valve opening amount of the ISC ₃ started to decrease at the time t ₅ , the engine 1
The amount of intake air supplied to each cylinder is reduced by an amount corresponding to a reduction in the valve opening amount of ISC3, and the fuel injection amount is reduced by air-fuel ratio control according to the reduced amount of intake air. The injection amount is supplied into the cylinder of the engine 1, and the torque generated by the engine 1 is reduced. Then at time t ₈ and starts power supply to the battery 8 stops the power supply from the alternator 2 to EHC 4, and sets the field current suppressing control by the regulator 7. Then, the decrease of the field current of the alternator 2 is started and the load of the engine 1 is decreased. However, since the opening amount of the ISC valve has been reduced and therefore the torque generated by the engine 1 has decreased, the engine 1
The rotational speed NE of does not decrease. Thus time t
₅ decreases gradually intake air amount of the cylinder of the engine 1 until t ₇ from also lowered gradually engine speed NE in accordance with the intake air amount, 320 msec to from time t ₅ to t ₇
Between the time delay of the time t ₆ to t _8, the power generation of the alternator 2 is gradually decreased gradually decreases the engine speed load of the engine 1 since the NE is not to give the driver a sense of discomfort.

11, FIG. 12 and FIG. 13 relate to the first engine speed control at the time of starting the engine, FIG. 11 is a time chart, FIG. 12 is a flowchart of processing executed in the main routine, and FIG. 13 is a 32 msec interrupt routine. It is a flowchart of the process performed by. As indicated by the alternate long and short dash line in (a) of FIG. 11, the first engine speed control at the time of engine start is such that the ISC valve is kept in the fully open position at the time of engine start, and after a predetermined time has elapsed, the ISC valve is gradually changed from the fully open position at engine start. Set to the target opening. The flowchart shown in FIG. 12 differs from the flowchart shown in FIG. 4 only in steps S1 and S3. Step S1 in the flowchart of FIG.
Then, the EHC total operating time counter CEHC is set to 25 sec.
The EHC energization start time counter CEHCON to 10
The EHC energization end time counter CEHCOF to 10
, The EHC setting flag XEHCSET is turned on, and the EHC
Delay timer EHCDLY for 2 sec or 500 msec
Set to. In step S3, the EHC energization start flag XEHCST is set to ON. The EHC delay timer EHCDLY is set based on the following. When the distance from the ISC valve to the cylinder is longer than usual, the ISC opening curve indicated by the one-dot chain line in the upper part of FIG. 11 is obtained.
To set the time for holding the SC valve in the fully open position from the engine start time to a value longer than usual, set EHCDLY to 2
Set to (sec). When the distance from the ISC valve to the cylinder is a normal length to obtain the solid ISC opening curve indicated by the symbol (c) in the upper part of FIG. 11, the time to keep the ISC valve in the fully open position from the engine start is set. In order to set the normal length, for example, EHCDLY is set to 500 (msec).
As described above, this is because the intake air that has passed through the ISC valve reaches the intake port of the engine and is sucked into the cylinder together with the fuel injection amount that is injected according to the intake amount to increase the torque generated by the engine. This is because it is desirable to increase the torque generated at the time of engine start as much as possible without decreasing the intake air amount from the ISC valve. Also, in the case of (B) described later, EHCDLY is set to 500 (msec).

Steps S11, S12 and S14 in the flowchart shown in FIG. 13 are the same as those in the flowchart shown in FIG. In step S13 in the flowchart of FIG. 13, step S12
Since it is determined that the EHC energization start flag XEHCST is ON, it is determined whether the EHC setting flag XEHCSET is ON or OFF. This time corresponds to time t ₁ in the time chart shown in FIG. This time t ₁ is also when the engine is started and the start signal STA is input to the ECU 5. In the first processing cycle of this interrupt routine in which XEHCST is determined to be ON in step S12, XEHC
Since SET is ON, step S16, then S17
However, since XEHCSET is turned off in the first processing cycle after the second processing cycle, step S15 is performed.
Proceed to. If it is determined in step S12 that XEHCST is off, the process proceeds to step S13A and step S13.
In A, the IS calculated with the ISC target opening calculated in step S11
The C target opening is set, and the process proceeds to step S14. In the first processing cycle, in step S16, the EHC delay timer EHCDLY is set to 2 sec in the case of (a),
In the case of (c), set to 500 msec. Next, in step S17, XEHCSET is turned off, and step S15
Proceed to. XEH in step S17 of the first processing cycle
Since CSET is turned off, the determination result of step S13 is NO in the second and subsequent processing cycles, and the process proceeds to step S15.

In step S15, EHCDLY is 0 (ms
ec) is determined, and when the determination result is YES, that is, in the case of (a), at time t ₃ after 2 seconds has elapsed from time t _1, and in the case of (c) after 500 msec has elapsed from time t ₁ to the time t _2, the process proceeds to step S20, by adding the current ISCSTEP ie 5 step set a target opening degree of the ISC in step S3 to the target opening of the ISC calculated in step S11 with the intact ISC rate A new target opening of the ISC valve is set, the valve is opened to that new opening, and the process proceeds to step S21. When the determination result of step S15 is NO, that is, in the case of (a), time t ₁
From the time until 2 seconds elapse until time t ₃ (c)
In the case of, from time t ₁ to time t ₂ until 500 msec elapses, the process proceeds to step S18 and step S18.
Then, EHCDLY = EHCDLY-32 (msec), that is, in the case of (a), 2000-32 (msec) is calculated,
In the case of (c), 500-32 (msec) is calculated, and the process proceeds to step S19. In step S19, the current ISC speed is maintained as it is, the target opening degree of ISC is held at the ISC fully open position, and this interrupt routine is ended. This IS
The C speed is changed by changing the cycle of the drive pulse of the stepping motor that drives the ISC valve to open and close.

Next, at step S21, after switching the control relay 9 from the battery 8 side to the EHC 4 side, the control of the field current to the alternator 2 is canceled in the case of supplying the normal battery 8 with electric power. And the field current is increased to end this interrupt routine.

As described above, the first engine speed control is performed by I
Depending on the length from the SC valve to the intake port of the engine,
If time t₁In the case of (a) after 500 msec from
Is the time t₁2 seconds after, the valve opening amount of ISC3 is decreased and opened.
Start. Therefore, supply from the ISC valve into the cylinder of engine 1
The amount of intake air to be injected and the amount of fuel injection corresponding to the amount of intake air
Engine that is supplied to the first cylinder and burns in the cylinder
The torque of 1 is the time t in the case of (c)₁To 500 ms
time t after ec_TwoUp to (a), time t ₁From 2
time t after sec_ThreeCan be up to. The result
As a result, the engine rotates, and in the case of (c), the time t
_TwoFrom (a), time t_ThreeFrom the ISC valve
The valve closes toward the throttle opening, and in the case of (c), time t
_ThreeIn the case of (a), time t_FourTo reach the target opening
You.

In the case of (c), after the time t ₂ , (a)
In the case of, after the time t ₃ , the alternator 2 sends EHC
In addition to supplying electric power to the engine 4, the regulator 7 increases the field current of the alternator 2 to increase the load of the engine 1 and heats the EHC 4 early. Until the opening of the ISC valve reaches the target opening from the fully opened position, the torque generated by the engine based on the intake air amount by opening the ISC valve and the load on the engine 1 due to the increase in the field current of the alternator 2 are balanced. Then, the engine speed NE of the engine 1 is maintained constant without increasing. Therefore, the engine speed NE does not become higher than usual and the driver does not feel uncomfortable. Note that, after time t _{4 in} the case of (a) and after time t _{3 in} the case of (c), the description will be omitted because the engine speed control after the engine start described above is followed.

11, FIG. 12 and FIG. 13 relate to the second engine speed control when starting the engine, FIG. 11 is a time chart, FIG. 12 is a flow chart of the processing executed in the main routine, and FIG. 13 is a 32 msec interrupt routine. It is a flowchart of the process performed by. The code (b) in the upper part of FIG.
When the distance from the ISC valve to the cylinder is longer than usual, the opening of the ISC valve goes from the fully open position at engine start to the target opening over time than usual when the distance from the ISC valve to the cylinder is longer than usual. To set. Further, the second engine speed control at the time of engine start is performed by setting the EHC delay timer EHCDLY to 5 in step S1 of the main routine of FIG.
Although it is set to 00 msec, only this point is different from the first engine speed control when starting the engine. The flowchart of FIG. 14 of the second engine speed control at the time of starting the engine is substantially the same as the flowchart of FIG. 13 of the first engine speed control at the time of starting the engine, except that the processing of steps S18 to S23 is different. It is the same. Therefore, the processing of these steps in the flowchart of FIG. 14 will be described below.

In steps S13A, S18 and S20 in the flow chart of FIG. 14, the ISC speed is constant, and in step S15 EHCDLY is 0 (ms).
ec) is determined, and when the determination result is YES, it is confirmed that 500 msec has elapsed from time t ₁ and time t _1
In step S18, the current ISC speed is maintained and the ISC target opening is set to the target opening set in step S11.
EP, that is, 5 steps are added to set a new target opening degree, and the process proceeds to step S23. If the determination result is NO, the process proceeds to step S19. In step S19, EHC
DLY = EHCDLY-32 (msec), that is, (a)
In case of (c), 2000-32 (msec) is calculated, in case of (c), 500-32 (msec) is calculated, and the process proceeds to step S20. In step S20, the current ISC speed is set to 1 /
The speed is set to 2 and the target opening of ISC is set to a new target opening by adding ISCSTEP set in step S3, that is, 5 steps to the target opening of ISC calculated in step S11, and proceeds to step S21. . IS
By setting the C speed to ½ of that speed, the closing speed of the ISC valve becomes slow as shown by the two-dot chain line in the upper part (b) of FIG. 11, and the target set in step S11 from the full opening of the ISC valve. The time required to reach the opening is longer than in the case where the ISC speed is kept at the current speed (C), and the arrival time t _{4 in} the case of (B) is the arrival time in the case of (C). It will be later than t ₃ . Next, in step S23, the control relay 9 is switched from the battery 8 side to the EHC 4 side, and the control of the field current to the alternator 2 is released to cancel the field current suppression control when power is normally supplied to the battery 8. To increase. The time when the control relay 9 is switched corresponds to time t ₂ .

In step S21, it is determined whether or not the alternator field transistor on-time counter TTRON is 20 msec. If the determination result is YES, step S2
3, the process proceeds to step S22 if NO. In step S22, TTRON = TTRON + 0.4 (msec)
Is calculated and the process proceeds to step S23. These steps S2
By 1 and S22, the field current of the alternator 2 is gradually increased, and the load of the engine does not suddenly increase.

As described above, the second engine speed control is performed by I
Depending on the length from the SC valve to the intake port of the engine, the valve opening speed of the ISC valve is not changed in the case of (c) and is changed to 1/2 in the case of (b). Then, the valve opening amount of ISC3 is reduced, and in the case of (c), from the time t ₂ to the time t ₃ , and in the case of (b), from the time t ₂ to the time t _4.
The C valve is closed from the fully open position to the target opening. Therefore I
The intake air amount supplied from the SC valve into the cylinder of the engine 1 and the fuel injection amount corresponding to the intake air amount are supplied into the cylinder of the engine 1, and the torque of the engine 1 generated by combustion in the cylinder is
In the case of (c) and (b), 500 msec from time t ₁
It can be maximized until a later time t ₂ . as a result,
The engine rotates, and then in both (c) and (b), the ISC valve starts closing toward the target opening from time t ₂ , and in (c) at time t ₃ , In the case of (b), the target opening is reached at time t ₄ . In both cases of (c) and (b), after the time t ₂ , the alternator 2 to EH
While supplying electric power to C4, the regulator 7 gradually increases the field current of the alternator 2 to gradually increase the load of the engine 1. Until the opening of the ISC valve reaches the target opening from the fully opened position, the torque generated by the engine based on the intake air amount by opening the ISC valve and the load on the engine 1 due to the increase in the field current of the alternator 2 are balanced. And then institution 1
The rotational speed NE of is kept constant without increasing. Therefore, the engine speed NE does not become higher than usual and the driver does not feel uncomfortable. The time t in the case of (a)
_{After 4} and in the case of (c), from time t ₃ onward, the explanation is omitted because the engine speed control after the engine start described above is followed.

[0044]

As described above, according to the present invention, when operating the electrically heated catalyst device, it is possible to supply sufficient electric power while suppressing fluctuations in the rotational speed of the internal combustion engine. You can avoid making people feel uncomfortable.

[Brief description of drawings]

FIG. 1 is a basic configuration diagram of an embodiment of the present invention.

FIG. 2 is a diagram showing a schematic configuration of an ISC device.

FIG. 3 is a time chart showing the first engine speed control after the engine is started.

FIG. 4 is a flowchart of a process of a first engine speed control after engine start executed in a main routine.

FIG. 5 is a first half flowchart of a process of a first engine speed control after engine start executed in an interrupt routine.

FIG. 6 is a second half flowchart of a process of first engine speed control after engine start executed in an interrupt routine.

FIG. 7 is a time chart showing the second engine speed control after the engine is started.

FIG. 8 is a flowchart of a process of a second engine speed control after engine start executed in a main routine.

FIG. 9 is a first half flowchart of a process of second engine speed control after engine start executed in an interrupt routine.

FIG. 10 is a second half flow chart of the process of the second engine speed control after engine start executed in the interrupt routine.

FIG. 11 is a time chart showing first and second engine speed control during engine start.

FIG. 12 is a flowchart of a process of first and second engine speed control at engine start, which is executed in a main routine.

FIG. 13 is a flowchart of a process of first engine speed control at engine startup, which is executed in an interrupt routine.

FIG. 14 is a flowchart of a process of a second engine speed control at engine start, which is executed in an interrupt routine.

FIG. 15 is a schematic configuration diagram of a control device for an internal combustion engine having an electrically heated catalyst device according to a conventional technique.

FIG. 16 is a time chart showing engine speed control according to a conventional technique.

[Explanation of symbols]

 1, 21 ... Internal combustion engine 2 ... Generator (alternator) 3 ... Intake amount varying means (ISC) 4 ... Electric heating type catalyst device (EHC) 5 ... Control device (ECU) 6 ... EHC active state judging means (activity judging means) 7 ... Power generation amount varying means (regulator) 8 ... Battery 9, 19 ... Power supply switching means (control relay)

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location F02D 41/04 ZAB 9523-3G F02D 41/04 ZAB 315 315 H02P 9/04 H02P 9/04 J 9 / 14 9/14 F

Claims (3)

[Claims] 1. A generator driven by an internal combustion engine, a battery charged by the generator, engine speed varying means for varying the engine speed of the internal combustion engine, and electric power from the generator or the battery. An electrically heated catalyst that is supplied with, and a power generation amount varying means that varies the power generation amount of the generator,
In an internal-combustion engine control device having an electrically heated catalyst device provided with, while increasing the engine speed by the engine speed variable means while supplying electric power to the electrically heated catalyst, the power generation amount variable A control device for an internal combustion engine having an electrically heated catalyst device, characterized in that the amount of power generated by the generator is increased by means. 2. The power generation amount varying means varies the power generation amount of the generator by varying the field amount of the generator, and the control device for the internal combustion engine increases the intake air amount of the internal combustion engine. The control device for an internal combustion engine having an electrically heated catalyst device according to claim 1, wherein the start of increasing the field amount of the generator is delayed by a predetermined time from the start. 3. The power generation amount changing means changes the power generation amount of the generator by changing the field amount of the generator, and the control device of the internal combustion engine increases the intake air amount of the internal combustion engine. And a control device for an internal combustion engine having an electrically heated catalyst device according to claim 1 or 2, wherein the field amount of the generator is gradually increased.