JP2842764B2 - Air introduction control device in exhaust pipe of internal combustion engine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air introduction control device for introducing secondary air into an exhaust pipe of a vehicular internal combustion engine in which a catalyst for purifying exhaust gas is disposed.

[0002]

2. Description of the Related Art FIG. 3 is a block diagram showing an example of a conventional air intake control device in an exhaust pipe of an internal combustion engine, in which 1 is an internal combustion engine, 2 is a transmission, 3 is an intake pipe of the internal combustion engine 1, and 4 is an intake pipe. The exhaust pipe 5, 5 is a catalyst device provided in the path of the exhaust pipe 4, 6 is a throttle valve, 7 is an air cleaner, and 8 is an electric air pump. Reference numeral 9 denotes an air introduction pipe whose one end is connected to the air pump 8 and the other end is connected to the exhaust pipe 4, and 10 is provided in the path of the air introduction pipe 9 and is discharged from the air pump 8 and exhausted through the air introduction pipe 9. A control valve for controlling the flow rate of the secondary air introduced into the pipe 4, a check valve 11 provided in the path of the air introduction pipe 9 for preventing exhaust gas from flowing toward the air pump 8, and a reference numeral 12 for introducing air 2 provided in the path of the pipe 9 and introduced into the exhaust pipe 4
A heater for heating the secondary air.

[0003] Reference numeral 14 denotes opening and closing of the control valve 10, and further, turning on of a relay 16 for an air pump and a relay 17 for a heater.
A controller for controlling / OFF, 15 is an engine battery as a power supply, and 18 is a generator mounted on the engine.

[0004] Next, the operation of the above-mentioned conventional air introduction control in the exhaust pipe of the internal combustion engine will be described. First, the internal combustion engine 1 is driven by supplying a mixed gas of air and fuel from the air cleaner 7. At this time, the throttle valve 6
Thus, the flow rate of the mixed gas is adjusted, and the output of the internal combustion engine 1 is adjusted. The output of the internal combustion engine 1 is transmitted to drive wheels via a transmission 2. Immediately after the start of the internal combustion engine 1, the air / fuel ratio becomes small, and carbon monoxide (C
0) and hydrocarbon (HC) emissions are increasing,
In addition, the temperature of the catalyst has not reached the reaction temperature and has not been sufficiently activated.

Therefore, at the same time as the start of the internal combustion engine 1 or after a lapse of a predetermined time from the start, the controller 14 controls the air pump relay 16 to be turned on, and power is supplied from the battery 15 to the air pump 8 so that the air pump 8 is driven. You. Secondary air discharged from the air pump 8 is introduced into the exhaust pipe 4 via the air introduction pipe 9. The internal combustion engine 1
Simultaneously with or after a predetermined period of time from the start of the heater, the heater relay 17 is controlled to be ON by the controller 14, and power is supplied from the battery 15 to the heater 12.
Is driven. Then, the secondary air flowing through the air introduction pipe 9 is heated when passing through the heater 12 and is introduced into the exhaust pipe 4.

[0006] The heated secondary air introduced into the exhaust pipe 4 is introduced into the catalyst device 5 together with the exhaust gas. In the catalyst device 5, the temperature of the catalyst is increased by the heated secondary air, so that the catalyst quickly reaches the reaction temperature and is activated. Then, in the exhaust gas, harmful CO and HC are converted into CO ₂ in the exhaust pipe 4 and the catalyst device 5, that is, the exhaust gas is purified and released into the atmosphere.

Here, since the air pump 8 and the heater 12 are operating at the same time, and the current consumed at that time is large, the generator 18 is always operating to charge the battery 15. Further, the amount of secondary air introduced into the exhaust pipe 4 is substantially constant as shown in FIG. 4, and the amount is maintained by the control valve 10 at an appropriate amount.

[0008]

As described above, the generator 18 consumes a part of the output of the internal combustion engine 1 to generate electric power.
Since the power supply 15 is configured to be charged during the power generation operation of the power generator 15, when the power generation of the power generator 18 is operated while supplying the power from the battery 5 to operate the air pump 8 and the heater 12, the power generator 15 is charged. The output of the internal combustion engine 1 is greatly consumed by the power generation operation of 18. As a result, the output of the internal combustion engine 1 is reduced, and the operation state of the internal combustion engine 1 is operated on a high load side as compared with a state in which power generation is not required. there were.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and stops the operation of the generator while the air pump and the heater are operating, thereby reducing the output of the internal combustion engine and reducing harmful effects. It is an object of the present invention to obtain an air introduction control device in an exhaust pipe of an internal combustion engine that suppresses exhaust gas emission.

[0010]

According to a first aspect of the present invention, there is provided an exhaust pipe air introduction control device for an internal combustion engine in which at least one of an air pump and a heater is operated to stop the power generation of a generator. It has a control device.

[0011] Further, according to a second aspect of the present invention, there is provided an exhaust pipe air introduction control device for an internal combustion engine, provided that at least one of an air pump and a heater is operating and a predetermined time has elapsed since the start of the internal combustion engine. And a control device for stopping the power generation of the generator during the period of time.

A third aspect of the present invention provides an exhaust pipe air introduction control device for an internal combustion engine, in which at least one of an air pump and a heater is operated to stop power generation of a generator, and a terminal of a power supply is provided. A control device is provided for activating the power generation of the generator when the voltage is equal to or lower than a predetermined value.

[0013]

According to the first aspect of the present invention, the power generation of the generator is stopped by the control device while at least one of the air pump and the heater is operating. Therefore, there is no large consumption of the output of the internal combustion engine due to the power generation of the generator during operation of the air pump and the heater, and the reduction of the output of the engine is suppressed,
Furthermore, operation on the high load side is avoided, and emission of harmful exhaust gas is suppressed.

[0014] In a second aspect of the present invention,
The power generation of the generator is stopped by the control device under the condition that at least one of the air pump and the heater is operating and for a predetermined time from the start of the internal combustion engine. Therefore, the load caused by the power generation of the generator is not applied to the internal combustion engine whose rotation is unstable due to the influence of the circulatory system or the like for a predetermined time from the start, and the unstable rotation of the internal combustion engine is promoted. There is no. Further, after a predetermined time has elapsed from the start of the internal combustion engine, the generator generates power and charges the power supply, so that the performance deterioration of the air pump and the heater due to insufficient charging of the power supply can be suppressed.

In a third aspect of the present invention,
When the terminal voltage of the power supply is equal to or lower than the predetermined value by the control device, the power generation of the generator is activated, and the power supply is charged by the generator. Therefore, the terminal voltage of the power supply is always maintained at a predetermined value or more, sufficient power is supplied from the power supply to the air pump and the heater, and a decrease in the performance of the air pump and the heater is suppressed.

[0016]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. Embodiment 1 FIG. Embodiment 1 is an embodiment according to the first invention of the present invention. FIG. 1 is a configuration diagram of an air introduction control device in an exhaust pipe of an internal combustion engine according to a first embodiment of the present invention. In FIG. 1, the same or corresponding portions as those in the conventional exhaust air introduction control device in an internal combustion engine shown in FIG. Are assigned the same symbols,
The description is omitted.

In the figure, reference numeral 20 denotes a control device, which controls opening and closing of the control valve 10 and turns on / off a relay 16 for an air pump and a relay 17 for a heater.
The FF is controlled, and the generator 18 is controlled via a control signal line 19.
Is configured to control the operation / stop of power generation.
The other configuration is the same as the configuration of the conventional air introduction control device in the exhaust pipe of the internal combustion engine shown in FIG.

Next, the operation of the first embodiment will be described. Simultaneously with the start of the internal combustion engine 1 or after a lapse of a predetermined time from the start, the controller 20 controls the air pump relay 16 to be turned on, and power is supplied from the battery 15 to the air pump 8 to drive the air pump 8. Then, the secondary air discharged from the air pump 8 is introduced into the exhaust pipe 4 via the air introduction pipe 9. Simultaneously with the start of the internal combustion engine 1 or after a lapse of a predetermined time from the start, the controller 20 controls the heater relay 17 to be turned on, and power is supplied from the battery 15 to the heater 12 to drive the heater 12. . Then, the secondary air flowing through the air introduction pipe 9 is heated when passing through the heater 12 and is introduced into the exhaust pipe 4. The amount of secondary air introduced into the exhaust pipe 4 is maintained at an appropriate amount by the control valve 10, and the temperature of the heated secondary air is higher than the exhaust temperature after the internal combustion engine 1 is started. Desirably, it is usually controlled at 300 to 400 ° C.

The heated secondary air introduced into the exhaust pipe 4 is introduced into the catalyst device 5 together with the exhaust gas. In the catalyst device 5, the temperature of the catalyst is increased by the heated secondary air, so that the catalyst quickly reaches the reaction temperature and is activated. Then, in the exhaust gas, harmful CO and HC are converted into CO ₂ in the exhaust pipe 4 and the catalyst device 5, that is, the exhaust gas is purified and released into the atmosphere.

The introduction of the heated secondary air into the exhaust pipe 4 by the operation of the air pump 8 and the heater 12 is usually continued until the catalyst is activated and stable purification is obtained. It is.

Here, when at least one of the air pump 8 and the heater 12 is operating, the control device 20
From the generator 18 via the control signal line 19
And the power generation of the generator 18 is stopped. When the air pump 8 and the heater 12 are not operating, the controller 20 sends a power generation operation command to the generator 18 via the control signal line 19 to operate the generator 18 to generate power. And
During the power generation operation of the generator 18, the power supply 15 is charged.

According to the first embodiment, when at least one of the air pump 8 and the heater 12 is operating, a power generation stop command is sent to the generator 18 via the control signal line 19, and the power generation of the generator 18 is performed. Since the control device 20 for stopping the engine is provided, the power generation of the generator 18 when the air pump 8 and the heater 12 consume a large amount of output of the internal combustion engine 1 is stopped, and the reduction of the output of the internal combustion engine 1 is suppressed. Can be. Further, the internal combustion engine 1 is operated on a low load side, and emission of harmful exhaust gas is suppressed.

The control device 20 controls the air pump 8
The generator 18 stops the power generation of the generator 18 when at least one of the heaters 12 is operating, and activates the power generation of the generator 18 when both the air pump 8 and the heater 12 are not operating. Is controlled, the output of the internal combustion engine 1 is suppressed from decreasing when the air pump 8 and the heater 12 operate, and the battery 15 is charged when the air pump 8 and the heater 12 do not operate. Internal combustion engine 1, air pump 8 and heater 12
Can be operated stably.

Embodiment 2 FIG. Embodiment 2 is an embodiment according to the second invention of the present invention. In the first embodiment, the control device 20 stops the power generation of the generator 18 when at least one of the air pump 8 and the heater 12 is operating, and when the air pump 8 and the heater 12 are not operating. Although the operation / stop of the power generation of the generator 18 is controlled so as to operate the power generation of the generator 18, in the second embodiment, the control is performed during the time from the start of the internal combustion engine 1 until a predetermined time elapses. With the device 20,
When at least one of the air pump 8 and the heater 12 is operating, the power generation of the generator 18 is stopped, and when both the air pump 8 and the heater 12 are not operating, the power generation of the generator 18 is operated. The operation / stop of the power generation of the machine 18 is controlled.

During a predetermined time, for example, several tens of seconds, from the start of the internal combustion engine 1, the internal combustion engine 1 is cold and its rotation is unstable due to the influence of the circulating system and the like. At this time, when the power generation of the generator 18 is operated, a load is applied to the internal combustion engine 1, which promotes unstable rotation of the internal combustion engine 1. According to the second embodiment, under the condition that at least one of the air pump 8 and the heater 12 is operating, the power generation of the generator 18 is stopped for a predetermined time from the start of the internal combustion engine 1. Such an unstable rotation of the internal combustion engine 1 is not promoted.

If power generation of the generator 18 is stopped while at least one of the air pump 8 and the heater 12 is operating, charging becomes insufficient depending on the capacity of the battery 15. Sufficient power cannot be supplied, and there is a risk that their performance may be reduced. According to the second embodiment, the air pump 8
Under a condition in which at least one of the heaters 12 is operating, the battery 15 can be charged by activating the power generation of the generator 18 after a lapse of a predetermined time from the start of the internal combustion engine 1, and the charge / discharge balance of the battery 15 can be maintained. Is maintained, and the performance of the air pump 8 and the heater 12 is not reduced.

Embodiment 3 FIG. Embodiment 3 is an embodiment according to the third invention of the present invention. In the third embodiment, as shown in FIG. 2, in addition to the configuration of the first embodiment, the control device 20 is configured to be able to detect the terminal voltage of the battery 15 via the voltage detection line 21.

In the third embodiment, similarly to the first embodiment, the air pump 8 and the heater 12 are controlled by the control device 20.
The power generation of the generator 18 is stopped when at least one of them is operating, and the power generation of the generator 18 is operated when both the air pump 8 and the heater 12 are not operating. At this time, the control device 20 monitors the terminal voltage of the battery 15 via the voltage detection line 21. Therefore, when the terminal voltage of the battery 15 falls below a predetermined value, the control device 20
Transmits a power generation operation command via the control signal line 19 to the generator 18.
To operate the power generation of the generator 18. This generator 18
The battery 15 is charged during the power generation operation of.

According to the third embodiment, when the terminal voltage of the battery 15 becomes equal to or lower than the predetermined value, the power generation of the generator 18 is activated. Is quickly generated and charged,
The deterioration of the performance of the air pump 8 and the heater 12 due to the shortage of the charge amount of the battery 15 is prevented, and the purification efficiency is not reduced.

[0030]

Since the present invention is configured as described above, it has the following effects.

According to the first aspect of the present invention, since the control device for stopping the power generation of the generator while at least one of the air pump and the heater is operating, the output of the internal combustion engine is greatly consumed. Power generation of the generator during operation of the air pump and the heater is stopped, and a decrease in the output of the internal combustion engine can be suppressed. Further, the internal combustion engine is operated on a low load side, and emission of harmful exhaust gas is suppressed.

According to the second aspect of the present invention, the power generation of the generator is stopped under a condition that at least one of the air pump and the heater is operating and for a predetermined time from the start of the internal combustion engine. Since the control device is provided, the balance of charge and discharge of the power supply is maintained, the performance of the air pump and the heater is prevented from deteriorating due to insufficient charging of the power supply, the purification efficiency is not reduced, and the internal combustion engine after starting is started. It does not promote unstable rotation of the motor.

According to the third aspect of the present invention, the power generation of the generator is stopped while at least one of the air pump and the heater is operating, and when the terminal voltage of the power supply is lower than a predetermined value, the power generation of the generator is stopped. Since the control device for activating the power generation is provided, the same effects as those of the first aspect of the invention can be obtained. In addition, when the charge amount of the power supply is insufficient, the generator is generated and quickly charged, and the charge amount of the power supply is reduced. The performance of the air pump and the heater is prevented from being deteriorated due to the shortage of air, and the purification efficiency is not reduced.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of an air introduction control device in an exhaust pipe of an internal combustion engine according to a first embodiment of the present invention.

FIG. 2 is a configuration diagram of an air introduction control device in an exhaust pipe of an internal combustion engine according to a third embodiment of the present invention.

FIG. 3 is a configuration diagram illustrating an example of a conventional air introduction control device in an exhaust pipe of an internal combustion engine.

FIG. 4 is a time chart of an introduced air amount in a conventional exhaust pipe air introduction control device for an internal combustion engine.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Internal combustion engine 4 Exhaust pipe 8 Air pump 9 Air introduction pipe 12 Heater 15 Battery (power supply) 18 Generator 20 Control device

Continuation of the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) F01N 3/30 F01N 3/20 F01N 3/24 F02D 29/06 H02P 9/04

Claims (3)

(57) [Claims] 1. An exhaust pipe air introduction control device for an internal combustion engine, wherein a heater is provided in a path of an air introduction pipe communicating an air pump and an exhaust pipe, and heated secondary air is introduced into the exhaust pipe. A power supply that supplies power to an air pump and the heater, a generator that generates power by an output of an internal combustion engine to charge the power supply, and a power generator that operates while at least one of the air pump and the heater operates. A control device for stopping power generation, and an air introduction control device in an exhaust pipe of an internal combustion engine. 2. An exhaust pipe air introduction control device for an internal combustion engine, wherein a heater is provided in a path of an air introduction pipe that communicates an air pump and an exhaust pipe, and heated secondary air is introduced into the exhaust pipe. A power supply that supplies power to an air pump and the heater, a generator that generates power by an output of an internal combustion engine to charge the power supply, under a condition that at least one of the air pump and the heater is operating, and A control device for stopping power generation of the generator for a predetermined time from the start of the internal combustion engine. 3. An exhaust pipe air introduction control device for an internal combustion engine, wherein a heater is provided in a path of an air introduction pipe that communicates an air pump and an exhaust pipe, and heated secondary air is introduced into the exhaust pipe. A power supply that supplies power to an air pump and the heater, a generator that generates power by an output of an internal combustion engine to charge the power supply, and a power generator that operates while at least one of the air pump and the heater operates. A control device for stopping power generation and activating the power generation of the generator when a terminal voltage of the power supply is equal to or lower than a predetermined value.