CN108612594A - Idling for internal combustion engine rotating speed controls - Google Patents

Abstract

The invention discloses a kind of idling for internal combustion engine revolution speed control devices, including：Superelevation height above sea level measures part, judges for carrying out vehicle super-high height above sea level idling；Switching part carries out internal combustion engine control under superelevation altitude mode for switching to superelevation altitude mode when vehicle is in superelevation height above sea level by superelevation height above sea level control section；Superelevation height above sea level control section, the air inflow and ignition advance angle for increasing cold in low temperature idling are to reach rotating speed of target；Even if in the case of no barometric pressure sensor, in the cold idling of 3000 meters of height above sea level or more, it is also ensured that engine target rotating speed；In superelevation Altitude Regions, it can be ensured that startability identical with level land and operation performance, and improve engine misses and cornering ability is bad.

Description

Internal combustion engine idle speed control

technical field

The invention relates to an engine control device for an internal combustion engine, in particular to an idle speed control device for an internal combustion engine.

Background technique

As shown in Figure 1, as the altitude increases, the density of the air drawn into the internal combustion engine decreases, resulting in a decrease in idle speed. In a fuel injection system that cannot detect atmospheric pressure, since the idle speed at high altitude becomes lower than the target idle speed at high altitude, the amount of intake air is increased and the engine speed is raised to the target idle speed by feedback control. The increment at this time is stored in the temporary storage device as a learned value. Normally, the same air volume correction value as in the warm state is supplied when the machine is cold. However, at such an ultra-high altitude of 3000 meters or more, the air intake required by the engine tends to increase dramatically when the engine is cold, so the value obtained when the engine is warm is the disadvantage of the above-mentioned solution. Ultra-high altitude idle speed correction with atmospheric pressure detection, specifically correcting the intake air volume according to atmospheric pressure and engine temperature. While there is no ultra-high altitude idle speed correction when the atmospheric pressure is detected, the intake air volume is increased through the speed feedback control when the engine is hot, and the increased amount is stored in the ECU as a learning value. Since the amount of air inhaled under the condition of the cold engine is more than the learned value when the engine is hot, the air intake is insufficient, and the idle speed is lower than the target speed, which may cause the engine to stall.

In the existing internal combustion engine field, the fuel injection system without an atmospheric pressure sensor uses the learning result of the warm engine, and the same learning value is used for the hot and cold engines. The specific composition is: ISCV driving value = basic driving value + ISC correction value + ISC learning value;

ISCV: idle speed control valve (solenoid valve or stepping motor); basic drive value: ISCV drive value according to preset machine temperature; ISC correction value: perform feedback control at preset target idle speed, that is, ISC, and increase/decrease ISC Correction value; ISC learning value: The correction value of ISC increase or decrease is used as the learning value.

The high altitude correspondence depends on the learning value; if the heat engine speed is lower than the target speed, the ISC actuation value is increased through the ISC, and the increment is stored as a learning value in the ECU temporary storage area; the saved learning value will be used at the next startup When used to increase the air intake. At very high altitudes, the ISC learning value stored during the warm engine becomes insufficient when the engine is cold, resulting in a lower idle speed.

Contents of the invention

In view of the above-mentioned shortcomings existing at present, the present invention provides an internal combustion engine idling speed control device, which can ensure the same starting and operating performance as that on flat ground in ultra-high altitude areas, and improve engine stalling and poor drivability.

In order to achieve the above object, embodiments of the present invention adopt the following technical solutions:

An internal combustion engine idle speed control device is an idle speed control device of an internal combustion engine mounted on a vehicle, comprising:

The ultra-high altitude measurement part is used to judge the idling speed of the vehicle at ultra-high altitude;

The switching part is used to switch to the ultra-high altitude mode when the vehicle is at an ultra-high altitude, and the internal combustion engine is controlled by the ultra-high altitude control part in the ultra-high altitude mode;

The ultra-high altitude control part is used to increase the intake air volume and ignition advance angle of the cold engine to reach the target speed when idling at low temperature.

According to an aspect of the present invention, it further includes: a threshold value setting unit, which is used to conduct a plateau test in the early stage to confirm the altitude cut-off point at which the idling speed of the cold machine continues to be low.

According to one aspect of the present invention, the O2FB learning value of each learning area under the altitude cut-off point is confirmed, and the minimum value is set as the ultra-high altitude judgment threshold.

According to one aspect of the present invention, the judging the idling speed of the vehicle at an ultra-high altitude includes: as the altitude increases, the air density decreases, and the A/F becomes richer; in order to compensate for this too rich air-fuel ratio, O2FB is corrected to reduce the supply The fuel quantity of the engine, and set it to the correct A/F, the fuel supply reduction at this time is stored in the ECU as the O2FB learning value; the O2FB learning value is divided into different areas by the throttle opening and engine speed value; conduct plateau experiments to obtain the O2FB learning value of the ultra-high altitude cut-off point; if the O2FB learning value of each area exceeds the O2FB learning value of the ultra-high altitude cut-off point, it is judged as an ultra-high altitude.

According to one aspect of the present invention, the ultra-high altitude demarcation point is 3000m above sea level.

According to an aspect of the present invention, the control of the internal combustion engine by the ultra-high altitude control part includes: control of the ignition timing of the internal combustion engine and correction of the ISCV driving value.

According to one aspect of the present invention, the control of the ignition period is: ignition period = basic ignition period + super high altitude ignition correction value; the correction of the ISCV drive value is: ISCV drive value = basic drive value + ISC correction value + ISC learning value + super high altitude ISCV correction value.

According to one aspect of the present invention, the control of the ignition period includes: preset an ignition correction value for each temperature of the machine; the correction of the ISCV driving value includes: preset an ISCV correction value for each temperature of the machine.

The advantages of the implementation of the present invention: the internal-combustion engine idle speed control device according to the present invention confirms the altitude cut-off point at which the idle speed of the cold machine continues to be low by carrying out plateau tests in the early stage, confirms the O2FB learning value of each learning area under this altitude, and Set the minimum value as the ultra-high altitude judgment threshold, and set the ultra-high altitude mode to control the internal combustion engine. Specifically, set the idle speed at this altitude, increase the ignition advance angle and intake air volume at the low temperature section of the cold engine, In order to achieve the target speed; in the later stage, the vehicle switches to the ultra-high altitude mode by itself according to the set value, switches to the ultra-high altitude mode, the low-temperature idle ignition timing is advanced, and the intake air volume is increased to achieve the target speed; thus even in the absence of an atmospheric pressure sensor Under certain circumstances, the target engine speed can also be guaranteed when the engine is idling at an altitude above 3,000 meters; in ultra-high altitude areas, it can ensure the same starting and operating performance as on flat ground, and improve engine stalling and poor driving performance.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the accompanying drawings that need to be used in the embodiments. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For Those of ordinary skill in the art can also obtain other drawings based on these drawings without making creative efforts.

Fig. 1 is the schematic diagram of engine level and plateau temperature described in the background technology of the present invention;

Fig. 2 is a schematic diagram of idling when the internal combustion engine is started in the background technology of the present invention;

Fig. 3 is a schematic diagram of idle speed when the internal combustion engine is started after being controlled by the internal combustion engine idle speed control device according to the present invention;

Figure 4 is a simplified overall schematic diagram of an internal combustion engine in which the preferred embodiment of the present invention may be practiced.

Detailed ways

The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some, not all, embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

Referring to FIG. 3 , there is shown a simplified overall schematic diagram of an internal combustion engine 1 equipped according to a preferred embodiment of the present invention. As shown in FIG. 1 , an internal combustion engine 1 is preferably a gasoline engine having a throttle motor 2 that operates a throttle valve 3 and a plurality of fuel injection valves 4 (one for each cylinder). As in a general engine, intake air enters the engine 1 through the throttle valve 3, and fuel is injected into the combustion chamber of each cylinder from the corresponding fuel injection valve 4. Air and fuel mix in the combustion chamber of each cylinder to create an air-fuel mixture. The air-fuel mixture is ignited by a spark plug (not shown), and combustion or explosion of the resulting air-fuel mixture reciprocates pistons 4 (one for each cylinder), thereby providing drive power for the vehicle in a conventional manner.

The internal combustion engine 1 also has an engine control unit (ECU) or device 11 that controls a throttle valve 3 (air intake amount) and a fuel injection valve 4 (fuel injection amount).

The engine control unit 11 preferably includes a built-in microcomputer having an intake air amount control routine for controlling the throttle valve 3 and a fuel injection amount control routine for controlling the fuel injection valve 4 as described below. The control unit 11 may also include other conventional components such as storage devices such as input interface circuits, output interface circuits, ROM (Read Only Memory) devices, and RAM (Random Access Memory) devices. The storage circuit stores processing results and control routines such as for operating the throttle valve 3 and the fuel injection valve 4 . The internal RAM of the engine control unit 11 stores states of various operation flags and various control data. The internal ROM of the engine control unit 11 stores operating parameters for controlling various operations of the throttle valve 3 and the fuel injection valve 4 . Those skilled in the art can easily understand from this disclosure that the precise structure and algorithm for the engine control unit 11 can be any combination of hardware and software that can realize various functions of the present invention. In other words, a "means-plus-function" clause used in the specification and claims shall include any structure or hardware and/or algorithm or software that can be used to carry out the function of the "means-plus-function" clause.

The control unit 11 is coupled with various sensors in a conventional manner to receive detection signals from the various sensors. Based on these detection signals, the engine control unit 11 is configured or programmed to control the throttle valve 3 and the fuel injection valve 4 . Specifically, based on these detection signals, the engine control unit 11 calculates control signals for the throttle motor 2 and the fuel injection valve 4 , and then sends these control signals to operate the throttle motor 2 and the fuel injection valve 4 .

More specifically, the engine control unit 11 is configured to receive various input signals from the following devices or sensors: air flow meter 12, throttle sensor 13, rotational speed sensor 14, coolant sensor 15, neutral switch (neutral switch) 16, Idle switch 17 and vehicle speed sensor 18. Sensors 12-18 are conventional components well known in the art. Since sensors 12-18 are well known in the art, these structures will not be discussed or detailed below. Also, as will be readily understood by those skilled in the art from this disclosure, the sensors 12-18 may be any type of sensor, structure, and/programming that may be used to implement the present invention.

The air flow meter 12 is configured and arranged to detect the intake air quantity of the engine 1 upstream of the position of the throttle valve 3 . Thus, the intake air amount is detected by the air flow meter 12 , which outputs a detection signal indicative of the intake air amount delivered to the combustion chamber of the engine 1 to the engine control unit 11 . The throttle sensor 13 is configured and arranged to detect the opening degree of the throttle valve 3 . Thus, the throttle position or opening of the throttle valve 3 is detected by the throttle sensor 13 , which outputs a detection signal indicating the throttle position or opening of the throttle valve 3 to the engine control unit 11 . The rotational speed sensor 14 is configured and arranged to detect the rotational speed of the engine 1 , for example, through the crank angle of a crankshaft of the engine 1 . Thereby, the engine speed is detected by the speed sensor 14 , which outputs a detection signal indicating the engine speed to the engine control unit 11 . The coolant sensor 15 is configured and arranged to detect the temperature of the coolant in the engine 1 . Thus, the temperature of the coolant in the engine 1 is detected by the coolant sensor 15 , which outputs a detection signal indicating the temperature of the coolant in the engine 1 to the engine control unit 11 . The neutral switch 16 is configured and arranged to detect whether a transmission (not shown) used in combination with the engine 1 is in a neutral shift position. Thus, the neutral position or state of the transmission is detected by the neutral switch 16 , which outputs a detection signal indicating the neutral position or state of the transmission to the engine control unit 11 . The idle switch 17 is configured and arranged to detect whether the engine 1 is in an idle state (ie, the accelerator is fully released). Thus, the idle state of the engine 1 is detected by the idle switch 17 which outputs a detection signal indicating the idle state of the engine 1 to the engine control unit 11 . The vehicle speed sensor 18 is configured and arranged to detect the running speed (vehicle speed) of the vehicle on which the engine 1 is installed. Thus, the running speed (vehicle speed) of the vehicle is detected by the vehicle speed sensor 18 which sends a detection signal indicating the running speed (vehicle speed) of the vehicle to the engine control unit 11 .

The exhaust system of the engine 1 preferably includes, among other components, an exhaust manifold 19 and a catalytic converter 20 disposed in an exhaust passage 21 extending from the exhaust manifold 19 . An oxygen sensor 22 is provided in the exhaust manifold 19 or in the exhaust passage 21 at a position upstream of the catalytic converter 20 . The oxygen sensor 22 is configured and arranged to detect whether the actual air-fuel ratio is rich or lean based on the oxygen concentration of the exhaust gas upstream of the catalytic converter 20 compared to a theoretical or stoichiometric air-fuel ratio.

As a sensor or device for detecting the air-fuel ratio, an air-fuel ratio sensor 32 capable of detecting a wide range of air-fuel ratios may also be used instead of the oxygen sensor 22 indicating a lean state. When the air-fuel ratio sensor 32 is provided, it is possible to directly measure the amount by which the air-fuel ratio deviates from the target air-fuel ratio. As a result, the intake air amount can be corrected (increased) by an appropriate amount based on the deviation amount of the air-fuel ratio.

The above is the concrete structure and control process of the internal combustion engine during concrete implementation, and the implementation of the present invention includes:

An idle speed control device is provided in the engine control unit 11 . The idle speed control device of the engine control unit 11 is configured or programmed as follows: through the plateau test in the early stage, confirm the altitude cut-off point at which the idle speed of the cold machine continues to be low, confirm the O2FB learning value of each learning area at this altitude, and set The minimum value is set as the ultra-high altitude judgment threshold, and the ultra-high altitude mode is set as the control of the internal combustion engine. Specifically, the idle speed is set at this altitude, and the ignition advance angle and intake air volume of the low-temperature section of the cold engine are increased to achieve The target speed; in the later stage, the vehicle switches to the ultra-high altitude mode by itself according to the set value. When switching to the ultra-high altitude mode, the low-temperature idle ignition timing is advanced, and the intake air volume is increased to reach the target speed; thus even in the absence of an atmospheric pressure sensor , when the engine is idling at an altitude above 3,000 meters, it can also ensure the target engine speed; in ultra-high altitude areas, it can ensure the same starting and operating performance as on flat ground, and improve engine stalling and poor driving performance.

The idle speed control device includes: an ultra-high altitude measuring part for judging the idling speed of the vehicle at an ultra-high altitude; a switching part for switching to an ultra-high altitude mode when the vehicle is at an ultra-high altitude. The high-altitude control part controls the internal combustion engine; the ultra-high-altitude control part is used to increase the intake air volume and ignition advance angle of the cold engine to achieve the target speed when idling at low temperature.

During specific implementation, the following processes are included:

1. The plateau test was carried out in the early stage to confirm the altitude cut-off point where the idling speed of the cold machine continues to be low.

2. Confirm the O2FB learning value of each learning area at this altitude, and set the minimum value as the ultra-high altitude judgment threshold.

3. Set the idle speed at this altitude, and increase the ignition advance angle and intake air volume in the low temperature section of the cold engine to reach the target speed.

4. In the later period, the vehicle switches to the ultra-high altitude mode by itself according to the set value.

It also includes the actual vehicle judgment and switching method:

①. Carry out ultra-high altitude idling judgment.

*Ultra-high altitude measurement means:

As the altitude increases, the air density decreases and the A/F becomes denser;

In order to compensate for this too rich air-fuel ratio, O2FB makes corrections;

Reduce the amount of fuel supplied to the engine and set it to the correct A/F (stoichiometric ratio);

The reduced amount of fuel supply at this time is stored in the ECU as the O2FB learning value;

The O2FB learning value is divided into learning values in different regions by the throttle opening and engine speed;

If the O2FB learning value in each area mentioned above exceeds the O2FB learning value at an altitude above 3000m;

It is judged as super high altitude.

②.Ultra high altitude control:

Switching to ultra-high altitude mode, the low-temperature idle ignition timing is advanced, and the intake air volume is increased to reach the target speed.

Ultra-high altitude control is specifically achieved through the following methods:

According to the O2FB learning value learned at the ultra-high altitude, the ultra-high altitude is measured, and the ignition timing advance angle and ISCV height correction are added, and the idle speed is set as the target speed.

Ignition period = basic ignition period + super high altitude ignition correction;

ISCV driving value = basic driving value + ISC correction value + ISC learning value + super high altitude ISCV correction value;

Ignition correction at ultra-high altitude: The ignition correction value can be preset for each temperature of the machine;

Super high altitude ISCV correction value: ISCV correction value can be preset for each temperature of the machine.

The advantages of the implementation of the present invention: the internal-combustion engine idle speed control device according to the present invention confirms the altitude cut-off point at which the idle speed of the cold machine continues to be low by carrying out plateau tests in the early stage, confirms the O2FB learning value of each learning area under this altitude, and Set the minimum value as the ultra-high altitude judgment threshold, and set the ultra-high altitude mode to control the internal combustion engine. Specifically, set the idle speed at this altitude, increase the ignition advance angle and intake air volume at the low temperature section of the cold engine, In order to achieve the target speed; in the later stage, the vehicle switches to the ultra-high altitude mode by itself according to the set value, switches to the ultra-high altitude mode, the low-temperature idle ignition timing is advanced, and the intake air volume is increased to achieve the target speed; thus even in the absence of an atmospheric pressure sensor Under certain circumstances, the target engine speed can also be guaranteed when the engine is idling at an altitude above 3,000 meters; in ultra-high altitude areas, it can ensure the same starting and operating performance as on flat ground, and improve engine stalling and poor driving performance.

The above is only a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any skilled person familiar with the art can easily think of changes or substitutions within the technical scope disclosed in the present invention. All should be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention should be determined by the protection scope of the claims.

Claims (8)

1. a kind of idling for internal combustion engine revolution speed control device is mounted in the idle speed control device of the internal combustion engine of vehicle, special Sign is, including：

Superelevation height above sea level measures part, judges for carrying out vehicle super-high height above sea level idling；

Switching part, for switching to superelevation altitude mode when vehicle is in superelevation height above sea level, by superelevation under superelevation altitude mode Height above sea level control section carries out internal combustion engine control；

Superelevation height above sea level control section, air inflow and ignition advance angle for increasing cold in low temperature idling are turned with reaching target Speed.

2. idling for internal combustion engine revolution speed control device according to claim 1, which is characterized in that further include：Threshold value configuration part, Confirm that cold idling speed continues relatively low height above sea level separation for carrying out highland test early period.

3. idling for internal combustion engine revolution speed control device according to claim 2, which is characterized in that confirm in the height above sea level separation Under each learning region O2FB learning values, and wherein minimum value will be set as superelevation height above sea level decision threshold.

4. idling for internal combustion engine revolution speed control device according to claim 1, which is characterized in that the progress vehicle super-high sea Pulling out idling judgement includes：With the raising of height above sea level, atmospheric density declines, and A/F thickens；In order to compensate for the air-fuel ratio of this overrich, O2FB makes corrections, and reduces the amount of fuel of supply engine, and is set to correct A/F, and fuel feed at this time subtracts It is stored in ECU as O2FB learning values on a small quantity；O2FB learning values are divided into not same district by throttle opening and engine speed The learning value in domain；Carry out the O2FB learning values that highland test obtains superelevation height above sea level separation；If the O2FB learning values in each region The above O2FB learning values of superelevation height above sea level separation, then be determined as superelevation height above sea level.

5. idling for internal combustion engine revolution speed control device according to claim 4, which is characterized in that the superelevation height above sea level separation For height above sea level 3000m.

6. the idling for internal combustion engine revolution speed control device according to one of claim 1 to 5, which is characterized in that the superelevation sea Pull out control section includes to the control of internal combustion engine：The amendment of control and ISCV driving values to internal combustion engine ignition timing.

7. idling for internal combustion engine revolution speed control device according to claim 6, which is characterized in that the control of the ignition timing For：Ignition timing=basic ignition period+superelevation height above sea level igniting compensating value；The ISCV drivings value is modified to：ISCV drives Value=basic driver value+ISC compensating values+ISC learning values+superelevation height above sea level ISCV compensating values.

8. idling for internal combustion engine revolution speed control device according to claim 7, which is characterized in that the control of the ignition timing Including：For the default igniting correction value of each temperature of machine；The amendment of the ISCV drivings value includes：It is default for each temperature of machine ISCV correction values.