JPH06146955A - Operation control device before warming-up for internal combustion engine - Google Patents

Abstract

PURPOSE:To prevent an engine from over-running by accelerating the warming-up of an exhaust purifying device by controlling ignition time in the lag side before detecting the warming-up completion of the engine and restricting the increasing ratio of intake air quantity to a specified value or less regardless of accelerator operation before the completion of warming-up. CONSTITUTION:In a control device of running before warming-up which controls the running of an internal combustion engine until the temperature of an exhaust gas purifying device installed in the exhaust system of the internal combustion engine rises enough to activate the exhaust gas purifying device, completing warmingup, a warming-up completion detecting means M1 is provided to detect the completion of the warming-up of the internal combustion engine. Until the warming-up completion detecting means M1 detects the completion of the engine, ignition time is controlled in the lag side more than ordinary ignition time by an ignition time controlling means M2. A throttle valve is provided to control intake air quantity according to the operation quantity of an accelerator, and an air quantity increase restricting means M3 including a sub-throttle valve for limiting intake air quantity is also provided to restrict the increasing ratio of intake air quantity to a specified value or less before detecting the completion of warming-up regardless of accelerator operation.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pre-warming operation control device for an internal combustion engine, and more particularly to a device for controlling the operation of the internal combustion engine until the exhaust purification device has reached the activation temperature or higher until completion of warming up.

[0002]

2. Description of the Related Art Conventionally, in order to accelerate the completion of warming up of an exhaust gas purification device, control has been performed to retard the ignition timing from the normal ignition timing. This is by retarding the ignition timing,
This is because the combustion timing is delayed and combustion is performed during the exhaust stroke to accelerate the temperature rise of the exhaust purification device. In order to avoid the problem of misfire due to the sudden operation of the accelerator during the retard control (rapid increase of the intake air amount), the retard control of the ignition timing is further improved. There is proposed an ignition timing control device for an internal combustion engine (Japanese Patent Laid-Open No. 3-246369) which sets a maximum value of an advance amount and controls so as not to retard or advance the maximum value.

[0003]

However, in this ignition timing control device, the maximum value of the retard angle amount is set according to the operating time of the internal combustion engine, so the retard angle amount for promoting warm-up is limited. However, there is a problem in that a large retard angle cannot be set. Therefore, it takes more time and fuel than necessary to warm up the exhaust purification device.

In order to maintain the idle speed,
The amount of idle air is increasing, and the throttle valve is operated to try to reduce this amount of idle air.However, it takes a certain amount of time to reduce the amount of idle air. However, there is a problem that a so-called overrun occurs, which is a state in which the rotation speed of the internal combustion engine is high.

The internal combustion engine pre-warming operation control apparatus according to the present invention solves these problems, completes the warm-up early, and maintains a stable operating state even when the throttle valve is operated during warm-up. It was made for the purpose of having adopted the following composition.

[0006]

As shown in FIG. 1, an internal combustion engine pre-warming operation control apparatus of the present invention includes an exhaust gas purification apparatus for purifying exhaust gas in an exhaust system of the internal combustion engine, and the exhaust gas purification apparatus A device for controlling the operation of the internal combustion engine until the device is warmed up to the activation temperature or higher, and a warm-up completion detecting means M1 for detecting completion of warm-up of the internal combustion engine, and at least completion of the warm-up. Until it is detected, ignition timing control means M2 for controlling the ignition timing to be retarded from the normal ignition timing, a throttle valve for varying the intake air amount of the internal combustion engine according to the operation of an accelerator, and the completion of the warm-up. Until is detected, regardless of the operation of the accelerator, an air amount increase suppressing means M3 for suppressing the increase rate of the intake air amount to the internal combustion engine to a predetermined value or less is provided.

Here, in addition to the throttle valve,
A sub-throttle valve that limits the intake air amount of the internal combustion engine is provided in the intake system of the internal combustion engine, and when the accelerator operation is not performed, the sub-throttle valve is held in a substantially fully closed state to suppress the increase in the air amount. The means M3 may be configured to open the sub-throttle valve at a speed determined based on the opening degree of the throttle valve when the accelerator is operated.

Further, in place of the air amount increase suppressing means M3, an air amount for prohibiting the increase of the intake air amount to the internal combustion engine is disabled until the completion of the warm-up is detected. A configuration including the increase prohibiting means M4 is also possible.

[0009]

In the internal combustion engine pre-warming operation control apparatus of the present invention configured as described above, at least the warm-up completion detecting means M is used.
Until 1 detects the completion of warming up of the internal combustion engine, the ignition timing control means M2 controls the ignition timing to be retarded from the normal ignition timing to accelerate the warming up of the exhaust emission control device. When the accelerator is operated before the warm-up is completed, the air amount increase suppression means M3 suppresses the rate of increase of the intake air amount to the internal combustion engine to a predetermined value or less regardless of the operation of the accelerator.

When the sub-throttle valve is provided, the sub-throttle valve is held in a substantially fully closed state when the accelerator is not operated, and when the accelerator is operated, the opening of the throttle valve is changed. By opening the sub-throttle valve at a speed determined based on this, a sudden increase in the intake air amount is prevented.

Furthermore, when the air amount increase inhibiting means M4 is provided in place of the air amount increase suppressing means M3, the intake air amount is increased by disabling the operation of the accelerator until the completion of warming up is detected. Ban.

[0012]

Preferred embodiments of the present invention will be described below in order to further clarify the structure and operation of the present invention described above. FIG. 2 is a schematic configuration diagram showing an automobile engine equipped with a control device according to an embodiment of the present invention and its peripheral devices.

As shown in FIG. 1, in the intake passage 2 of the engine E / G, an air cleaner 3, an air flow meter 4, a throttle valve 8, a surge tank 9 for suppressing the pulsation of the intake air, and an engine from the intake air intake port. A fuel injection valve 10 that supplies fuel to the E / G is provided. The intake air taken in through the intake passage 2 is supplied to the fuel injection valve 10
It is mixed with fuel injected from the engine and sucked into the combustion chamber 11 of the engine E / G. This fuel-air mixture is used in the combustion chamber 1
A spark plug 12 ignites a spark in the engine 1 to drive the engine E / G by explosive combustion. The gas (exhaust gas) burned in the combustion chamber 11 is guided to the catalyst device 16 through the exhaust passage 15, is purified, and is then discharged to the atmosphere.

The throttle valve 8 is connected to the accelerator pedal 5 via a wire 6 and a link 7 so that the depression amount of the accelerator pedal 5 becomes the opening degree of the throttle valve 8. The link 7 is fixed to the link 7 with the throttle valve 8 closed to disable the operation of the accelerator pedal 5.
Is provided.

The spark plug 12 has a distributor 2
A high voltage is applied from the igniter 22 via 1 and the ignition timing is determined by the application timing. The distributor 21 distributes the high voltage generated by the igniter 22 to the ignition plugs 12 of the respective cylinders, and outputs 24 pulse signals to the distributor 21 for one rotation (two rotations of the crankshaft). A rotation speed sensor 23 is provided.

Further, in the intake passage 2 of the engine E / G,
A bypass passage 31 is formed so as to bypass the intake passage portion where the throttle valve 8 is provided, and an idle speed control valve (hereinafter referred to as ISCV) 32 is provided in the bypass passage 31. I
The SCV 32 includes a valve body whose valve opening is controlled by a solenoid, and controls the flow rate of air supplied to the engine E / G when the throttle valve is fully closed (idle time). By controlling the ISCV 32, the idling speed is controlled to the target speed.

Further, in the engine E / G and its peripheral devices, as a sensor for detecting the operating state of the engine E / G, in addition to the rotational speed sensor 23 described above, the opening degree of the throttle valve 8 and the throttle are detected. Valve 8
Throttle position sensor 43 having a built-in idle switch 42 for detecting the fully closed state of the intake air, and an intake air temperature sensor 4 arranged in the intake passage 2 for detecting the temperature of intake air (intake air)
1, an air flow meter 4 for detecting the amount of intake air, and a water temperature sensor 4 arranged in the cylinder block for detecting the cooling water temperature
4. An oxygen concentration sensor 45 provided in the exhaust passage 15 for detecting the oxygen concentration in the exhaust gas, a catalyst bed temperature sensor 46 provided in the catalyst device 16 for detecting the temperature of the catalyst bed, and a shift position can run. A shift position signal 47 for issuing a signal when the vehicle is in a different position, a vehicle speed sensor 48 for detecting the vehicle speed, and the like are provided. Detection signals from these sensors are input to an electronic control unit (ECU) 70.

As shown in FIG. 3, the ECU 70 is constructed as a logical operation circuit centered on a microcomputer, and more specifically, it executes various kinds of arithmetic processing for controlling the engine E / G according to a preset control program. A CPU 70a, a ROM 70b in which control programs and control data necessary for executing various arithmetic processes in the CPU 70a are stored in advance, and a RAM 70c in which various data necessary for executing various arithmetic processes in the CPU 70a are temporarily read and written. , A / D converter 70d and input processing circuit 70 for inputting detection signals from the respective sensors
e, the igniter 2 according to the calculation result in the CPU 70a
2. The fuel injection valve 10, the ISCV 32, the throttle limiting mechanism 50, and the like are provided with an output processing circuit 70f that outputs a drive signal. The ECU 70 also includes a power supply circuit 70g connected to the battery 88, and is configured to supply a required voltage to each unit.

With the ECU 70 thus configured,
The fuel injection amount is calculated based on the detection signal from each sensor, and the fuel injection valve 1
An air-fuel ratio control for driving 0 to open the valve is performed. In addition, the igniter 22, the ISC, etc., depending on the operating state of the engine E / G.
The V32, the throttle limiting mechanism 50 and the like are drive-controlled, and ignition timing control and ISCV control are performed. These controls are well known and will not be described. Next, pre-warming operation control in the embodiment will be described.

When the engine E / G is started, the ECU 7
The start-up process routine executed by the CPU 70a of No. 0 will be described with reference to FIG. When the engine E / G is started, the throttle limiting mechanism 50 is operated (step S100). Since the throttle limiting mechanism 50 fixes the link 7 with the throttle valve 8 fully closed, the accelerator pedal 5 cannot be depressed while the throttle limiting mechanism 50 is operating.

Next, the water temperature Tw and the set water temperature Tws are compared (step S110). Here, the water temperature Tw is obtained from the water temperature sensor 44 via the A / D converter 70d by the ECU.
The cooling water temperature is input to 70, and the set water temperature Tws is a set value of the cooling water temperature stored in advance in the ROM 70b as a temperature that does not require warming up. Also, set water temperature Tws
Is determined by the characteristics of the engine E / G and the catalyst device 16.

When the water temperature Tw is lower than the set water temperature Tws, it is determined that warm-up is necessary, and the ignition timing is controlled to the retard side (step S120). In this case, the ignition timing is controlled to be retarded until the catalyst bed temperature Te becomes higher than the set catalyst bed temperature Tes (step S13).
0) When the catalyst bed temperature Te becomes higher than the set catalyst bed temperature Tes, the throttle limiting mechanism 50 is released, the ignition timing is shifted to normal control (step S140), and this routine is ended. Here, the catalyst bed temperature Te is determined by the ECU 70 from the catalyst bed temperature sensor 46 via the A / D converter 70d.
Is the temperature of the catalyst bed input to, and the set catalyst bed temperature Te
s is a temperature in advance of the ROM 70b, which is a temperature at which the catalyst function sufficiently operates
This is the set value of the catalyst bed temperature stored in.

On the other hand, when the water temperature Tw is higher than the set water temperature Tws in step S110, it is determined that warming up is not necessary, the throttle limiting mechanism 50 is released, and the ignition timing is shifted to normal control (step S140). , This routine ends. Therefore, when the engine E / G is restarted, normal ignition timing control is performed without performing retardation control for warming up. The operation of the throttle limiting mechanism 50 in step S100 may be performed immediately before step S120. In this case, it is desirable to release the throttle limiting mechanism 50 in step S140 immediately after step S130.

According to the pre-warming operation control apparatus for the internal combustion engine of the embodiment described above, the throttle valve 8 is not opened during the warming-up, so that the retard amount of the ignition timing can be set large. . Therefore, the warm-up can be completed early, so that the function of the catalyst device 16 can be fully exerted, and wasteful fuel is not consumed. Moreover, since the emission does not deteriorate, the global environment can be protected.

In this embodiment, the link 7 is fixed so that the throttle valve 8 is fully closed.
A configuration in which the accelerator pedal 5 is fixed or a configuration in which the connection between the throttle valve 8 and the link 7 is disconnected is also suitable. When the accelerator pedal 5 is fixed, the accelerator pedal 5 cannot be depressed, but when the connection between the throttle valve 8 and the link 7 is disconnected, the accelerator pedal 5 can be depressed, but the throttle valve 8 does not open.

Next, a second embodiment of the present invention will be described. The pre-warming operation control device for the internal combustion engine of the second embodiment is
As shown in FIG. 5, the throttle limiting mechanism 50 is removed from the hardware configuration of the first embodiment, the accelerator pedal 5 and the throttle valve 8 are directly connected, and the sub throttle valve 60 and the sub throttle valve 60 are driven in the intake passage 2. This is a configuration including an actuator 61. The actuator 61 is a CPU for input signals from each sensor.
70a is driven by the drive signal calculated and output,
The opening degree of the sub throttle valve 60 is changed.

The operation at the time of starting the engine E / G of the second embodiment will be described with reference to the starting processing routine of FIG. First, when the engine E / G is started, the actuator 6
A drive signal is output from the ECU 70 to 1, the sub throttle valve 60 is fully closed, and ISCV control is started (step S200). The ISCV control is to adjust the ISCV 32 so that the idling rotation speed becomes a predetermined target rotation speed according to the water temperature Tw.

Next, the water temperature Tw and the set water temperature Tws are compared (step S210). Water temperature Tw is set Water temperature Tws
When it is smaller, the shift is set to a travelable position (step S220), and when the accelerator pedal 5 is operated (step S230), the sub throttle is opened based on the opening degree of the throttle valve 8 opened by the accelerator operation. The opening speed of the valve 60 is calculated (step S24
0), the sub-throttle valve 60 is driven at that speed (step S250). The opening speed of the sub-throttle valve 60 can be obtained from the relationship shown in FIG. 8, for example.

FIG. 8 shows an example of the relationship between the opening speeds of the throttle valve 8 and the sub-throttle valve 60. The throttle valve 8 can be opened up to a predetermined opening degree.
The opening speed of the sub-throttle valve 60 is proportional to the opening of the sub-throttle valve 60, and the opening speed of the sub-throttle valve 60 is made constant when the opening exceeds a predetermined opening. This constant value is a value that is set so that the air-fuel ratio of the air-fuel mixture supplied to the engine E / G does not suddenly increase and misfires, and is determined by the characteristics of the engine E / G. is there. Therefore, even if the throttle valve 8 is suddenly opened by depressing the accelerator pedal 5 during warm-up, the opening speed of the sub-throttle valve 60 is controlled, and the intake air amount only slowly increases.
As a result, the air-fuel ratio of the air-fuel mixture does not suddenly increase, and the engine E / G does not misfire and stop.

On the other hand, when the water temperature Tw is lower than the set water temperature Tws (step S210), the shift is not in the travelable position (step S220), or even if the shift is in the travelable position, the accelerator pedal is operated. If the operation of 5 is not performed (step S230), the ignition timing is controlled to the retard side (step S230).
260), promote warm-up.

Steps S220 to S260 are repeated until the catalyst bed temperature Te becomes higher than the set catalyst bed temperature Tes (step S270). When the catalyst bed temperature Te becomes higher than the set catalyst bed temperature Tes, it is judged that the warm-up is completed. Then, the sub-throttle valve 60 is fully opened, the ignition timing is shifted to normal control (step S280), and this routine is ended.

When the water temperature Tw is higher than the set water temperature Tws in step S210, it is determined that the warm-up is not necessary, the sub-throttle valve 60 is fully opened, and the ignition timing is shifted to the normal control (step S280). This routine ends. Therefore, when the engine E / G is restarted, normal ignition timing control is performed without performing retardation control for warming up.

According to the pre-warming pre-warming operation control apparatus for the internal combustion engine of the second embodiment described above, when the accelerator pedal 5 is not operated, the retard amount of the ignition timing is set to a large value, so the warm-up is performed. Can be completed early, and the function of the catalyst device 16 can be fully exhibited. Therefore, wasteful fuel is not consumed and emission is not deteriorated, so that the global environment can be protected.

Further, when the accelerator pedal 5 is operated, the air-fuel ratio of the air-fuel mixture is prevented from suddenly increasing.
Since the sub-throttle valve 60 is opened at a speed determined based on the opening degree of the throttle valve 8, it is possible to prevent the engine E / G from stopping due to a misfire. Further, since the control of the idle valve can be synchronized with the control of the opening speed of the sub-throttle valve 60, the control of the idle valve is not delayed with respect to the control of the advance amount of the ignition timing, and the engine E / G is not delayed. Overrun can be prevented.

In the second embodiment, the sub-throttle valve 60 is used for the opening of the throttle valve 8 up to a predetermined opening.
Although the opening speed of the sub-throttle valve 6 is driven in proportion to the opening speed of the engine E / G, the sub-throttle valve 6 is driven at a constant opening speed within a range where the engine E / G does not misfire.
A configuration in which the opening speed of 0 is changed over time to drive, a configuration in which the sub-throttle valve 60 is driven with a predetermined response delay with respect to the opening of the throttle valve 8, a process of smoothing the opening of the throttle valve 8 (previous opening Also, a configuration in which the opening of the sub-throttle valve 60 is controlled by the opening obtained by performing a weighted average of the current opening and the present opening is suitable.

The embodiment of the present invention has been described above.
The present invention is not limited to these examples, and it goes without saying that the present invention can be implemented in various modes without departing from the scope of the present invention.

[0037]

As described above, in the pre-warming operation control apparatus for an internal combustion engine of the present invention, the control is performed so that the intake air amount does not suddenly increase during warm-up, so the ignition timing is retarded. The amount can be set large and warm-up can be completed early. Further, it does not consume useless fuel. Therefore, the exhaust emission control device can fully exhibit its function, which can contribute to the preservation of the global environment.

[Brief description of drawings]

FIG. 1 is a block diagram illustrating a basic configuration of an internal combustion engine pre-warming operation control device of the present invention.

FIG. 2 is a schematic configuration diagram showing an automobile engine equipped with a control device according to an embodiment of the present invention and peripheral devices thereof.

FIG. 3 is a block diagram showing an electrical configuration of a control system centered on an ECU 70.

FIG. 4 is a flowchart showing a start-up processing routine executed by a CPU 70a of the ECU 70.

FIG. 5 is a schematic configuration diagram showing an automobile engine equipped with a control device according to a second embodiment of the present invention and peripheral devices thereof.

FIG. 6 is an ECU of a control device according to a second embodiment of the present invention.
7 is a block diagram showing an electrical configuration of a control system centered on 70. FIG.

FIG. 7 is an ECU of a control device according to a second embodiment of the present invention.
10 is a flowchart showing a start-up processing routine executed by a CPU 70a of 70.

8 is a graph showing an example of the relationship between the opening degree of the throttle valve 8 and the opening speed of the sub throttle valve 60. FIG.

[Explanation of symbols]

 M1 ... Warm-up completion detecting means M2 ... Ignition timing control means M3 ... Air amount increase suppressing means M4 ... Air amount increase prohibiting means E / G ... Engine 2 ... Intake passage 3 ... Air cleaner 4 ... Air flow meter 5 ... Accelerator pedal 6 ... Wire 7 ... Link 8 ... Throttle valve 9 ... Surge tank 10 ... Fuel injection valve 12 ... Spark plug 15 ... Exhaust passage 16 ... Catalyst device 21 ... Distributor 22 ... Igniter 23 ... Rotation speed sensor 31 ... Bypass passage 32 ... ISCV 41 ... Intake air temperature Sensor 42 ... Idle switch 43 ... Throttle position sensor 44 ... Water temperature sensor 45 ... Oxygen concentration sensor 46 ... Catalyst bed temperature sensor 47 ... Shift position signal 48 ... Vehicle speed sensor 50 ... Throttle limiting mechanism 60 ... Sub throttle valve 61 ... Actuator 70 ... ECU 70a ... C PU 70b ... ROM 70c ... RAM 70d ... A / D converter 70e ... Input processing circuit 70g ... Power supply circuit 88 ... Battery

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Claims (3)

[Claims] 1. An apparatus for controlling an operation of an internal combustion engine until an exhaust system of the internal combustion engine is provided with an exhaust purification apparatus for purifying exhaust gas, and the exhaust purification apparatus controls the operation of the internal combustion engine until completion of warming up to an activation temperature or higher. Warm-up completion detecting means for detecting completion of warm-up of the engine, ignition timing control means for controlling ignition timing to be retarded from normal ignition timing at least until completion of warm-up is detected, and accelerator A throttle valve that varies the intake air amount of the internal combustion engine in accordance with an operation, and a rate of increase in the intake air amount to the internal combustion engine, regardless of the operation of the accelerator, until the completion of warming up is detected. A pre-warming operation control device for an internal combustion engine, comprising: an air amount increase suppression unit that suppresses the amount to a predetermined value or less. 2. The pre-warm-up operation control device for an internal combustion engine according to claim 1, wherein, in addition to the throttle valve, a sub-throttle valve for limiting an intake air amount of the internal combustion engine is provided in an intake system of the internal combustion engine. In addition, in a state in which the accelerator operation is not performed, the sub-throttle valve is held in a substantially fully closed state, and the air amount increase suppression means is based on the opening degree of the throttle valve when the accelerator is operated. A pre-warming operation control device for an internal combustion engine, which is means for opening the sub-throttle valve at a fixed speed. 3. The pre-warming operation control device for an internal combustion engine according to claim 1, wherein the accelerator operation is disabled until the completion of warming up is detected instead of the air amount increase suppressing means. A prewarming operation control device for an internal combustion engine, comprising an air amount increase inhibiting means for inhibiting an increase in the intake air amount to the internal combustion engine.