WO2019196841A1

WO2019196841A1 - Rotational speed control device for internal combustion engine idling

Info

Publication number: WO2019196841A1
Application number: PCT/CN2019/081943
Authority: WO
Inventors: 江海; 陈云; 涉谷良夫; 陈奋楠
Original assignee: 三国(上海)企业管理有限公司; 株式会社三国
Priority date: 2018-04-09
Filing date: 2019-04-09
Publication date: 2019-10-17
Also published as: CN108612594B; CN108612594A

Abstract

A rotational speed control device for internal combustion engine idling, comprising: an ultra high altitude measurement portion, which is used for determining ultra high altitude idling of a vehicle; a switching portion, which is used for switching to ultra high altitude mode when the vehicle is at an ultra high altitude, wherein an internal combustion engine is controlled by an ultra high altitude control portion under ultra high altitude mode; the ultra-high altitude control portion, which is used to increase the air intake and an ignition advance angle of a cold engine during low temperature idling so as to reach a target rotational speed. Even in the absence of an atmospheric pressure sensor, the target idling rotational speed of an engine may be guaranteed during cold engine idling above an altitude of 3,000 meters, thus the same starting performance and operating performance may be guaranteed as on ground level, and engine flameout and poor driving performance may be improved at an ultra high altitude.

Description

Internal combustion engine idle speed control device

Technical field

The present invention relates to an engine control device for an internal combustion engine, and more particularly to an idle speed control device for an internal combustion engine.

Background technique

As shown in FIGS. 1 and 2, as the height increases, the density of the air sucked into the internal combustion engine decreases, resulting in a decrease in the idle speed. In the fuel injection system in which the atmospheric pressure cannot be detected, since the idle rotation speed at the high altitude becomes lower than the target idle speed at the high altitude, the intake air amount is increased by the feedback control and the engine rotation speed is raised to the target idle speed. The increment at this time is stored as a learning value in the temporary storage device. Normally, the same air volume correction value is also supplied to the heat engine when the machine is cold. However, in such an ultra-high altitude of 3,000 meters or more, the engine requires a drastic increase in the amount of intake air when the engine is cold, so the value obtained at the time of the heat engine is insufficient in the above-described scheme. Ultra-high altitude idle speed correction with atmospheric pressure detection, specifically correcting intake air volume based on atmospheric pressure and engine temperature. In the absence of atmospheric pressure detection, the ultra-high altitude idle speed is corrected. When the heat engine is used, the intake air amount is increased by the speed feedback control, and the increased amount is stored as a learning value in the ECU. Since the amount of intake air in the cold machine is more than the learned value of the heat engine, the intake air amount is insufficient, and the idle speed is lower than the target speed, which may cause the engine to stall.

In the field of the internal combustion engine, the fuel injection system without the atmospheric pressure sensor uses the learning result when the heat engine is used, and the cooling machine uses the same learning value. The specific configuration is: ISCV drive value = basic drive value + ISC correction value + ISC learning value;

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

The high altitude corresponds to the learning value. If the heat engine speed is lower than the target speed, the ISC action value is increased by ISC, and the increment is stored as a learning value in the ECU temporary storage area; the saved learning value is Use to increase the amount of intake air. At ultra-high altitudes, the ISC learning value stored during the thermal engine becomes insufficient during cold operation, resulting in a low idle speed.

Summary of the invention

In view of the above-mentioned deficiencies, the present invention provides an idle speed control device for an internal combustion engine which can ensure the same startability and operational performance as a flat ground and improve engine misfire and poor driving performance in an ultra-high altitude region.

In order to achieve the above object, an embodiment of the present invention adopts the following technical solution: an idle speed control device for an internal combustion engine, which is an idle speed control device of an internal combustion engine mounted on a vehicle, including: an ultra-high altitude measuring portion for performing an ultra-high altitude of the vehicle Idle speed judgment; the switching part is used to switch to the ultra-high altitude mode when the vehicle is at an ultra-high altitude, the internal combustion engine control 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 at the low temperature idle speed The intake air amount of the cold machine and the ignition advance angle to reach the target speed.

According to an aspect of the invention, the method further includes: a threshold setting unit configured to perform an altitude test in the early stage to confirm an altitude demarcation point at which the idle speed of the cold engine is continuously low.

In accordance with one aspect of the invention, the O2FB learning value for each learning region at the altitude demarcation point is determined and the minimum value is set to the ultra-high altitude determination threshold.

According to an aspect of the invention, the determining of the ultra-high altitude idle speed of the vehicle includes: as the altitude increases, the air density decreases, and the A/F becomes rich; in order to compensate for the excessive air-fuel ratio, the O2FB is corrected to reduce the supply. The fuel quantity of the engine is set to the correct A/F. The amount of 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 the engine speed. Value; the O2FB learning value of the super-high altitude demarcation point is obtained by the altitude test; if the O2FB learning value of each area exceeds the O2FB learning value of the ultra-high altitude demarcation point, it is determined as the super-high altitude. According to an aspect of the invention, the super-high altitude demarcation point is 3000 m above sea level.

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

According to an aspect of the invention, the ignition timing is controlled by: ignition timing = basic ignition timing + super high altitude ignition correction value; and the correction of the ISCV driving value is: ISCV driving value = basic driving value + ISC correction value + ISC learning value + super high altitude ISCV correction value.

According to an aspect of the invention, the controlling of the ignition timing includes: presetting an ignition correction value for each temperature of the machine; and modifying the ISCV driving value comprises: presetting an ISCV correction value for each temperature of the machine.

Advantages of the embodiments of the present invention: The idle speed control device for the internal combustion engine of the present invention confirms the O2FB learning value of each learning area at the altitude by confirming the altitude demarcation point of the idle idle speed of the cold machine in the early stage of the altitude test. And set the minimum value to the super-high altitude determination threshold, and set the super-high altitude mode to control the internal combustion engine, specifically, setting the idle speed at the altitude, increasing the ignition advance angle and the intake air amount of the cold low temperature section, In order to reach the target speed; the vehicle switches to the ultra-high altitude mode according to the set value, switches to the ultra-high altitude mode, the low-temperature idle ignition timing advances, and the intake air increases to reach the target speed; thus even without the atmospheric pressure sensor In the case of the idling of the 3,000 meters above sea level, the target speed of the engine can also be guaranteed; at the super-high altitude, the same startability and operational performance as the flat ground can be ensured, and the engine stall and poor driving performance can be improved.

DRAWINGS

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings to be used in the embodiments will be briefly described below. It is obvious that the drawings in the following description are only some embodiments of the present invention. Those skilled in the art can also obtain other drawings based on these drawings without paying any creative work.

1 is a schematic diagram of engine flat and plateau temperatures according to the background art of the present invention;

2 is a schematic diagram of idle speed when the internal combustion engine is started in the background art of the present invention;

3 is a schematic diagram showing the idle speed of the internal combustion engine after the control of the idle speed control device of the internal combustion engine according to the present invention;

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

detailed description

The technical solutions in the embodiments of the present invention are clearly and completely described in the following with reference to the accompanying drawings in the embodiments of the present invention. It is obvious that the described embodiments are only a part of the embodiments of the present invention, but not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative efforts are within the scope of the present invention.

Referring to Figures 3 and 4, there is shown a simplified overall schematic view of an internal combustion engine equipped in accordance with a preferred embodiment of the present invention. As shown in FIG. 4, the internal combustion engine 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 the case of a general engine, intake air enters the engine 1 through the throttle valve 3, and fuel is injected from the corresponding fuel injection valve 4 into the combustion chamber of each cylinder. Air and fuel are mixed in the combustion chamber of each cylinder to form an air fuel mixture. The air-fuel mixture is ignited by a spark plug (not shown), and the resulting combustion or explosion of the air-fuel mixture reciprocates the piston 4 (one of the cylinders), thereby providing the driving force for the vehicle in a conventional manner.

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

The engine control unit 11 preferably includes a built-in microcomputer having an intake air amount control history for controlling the throttle valve 3 and a fuel injection amount control history for controlling the fuel injection valve 4 as follows. The control unit 11 may also include other conventional components of a storage device such as an input interface circuit, an output interface circuit, a ROM (Read Only Memory) device, and a RAM (Random Access Memory) device. The storage circuit stores processing results and control procedures such as for operating the throttle valve 3 and the fuel injection valve 4. The internal RAM of the engine control unit 11 stores the state of various operational 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 will readily appreciate 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 implement the various functions of the present invention. In other words, the "means plus function" statement used in the specification and claims should include any structure or hardware and/or algorithm or software that can be used to implement the functionality of the "device plus function" statement. Control unit 11 is coupled to various sensors in a conventional manner to receive detection signals from 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 transmits 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: air flow meter 12, throttle sensor 13, speed sensor 14, coolant sensor 15, neutral switch 16 The idle switch 17 and the 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. Moreover, those skilled in the art will readily appreciate from this disclosure that sensors 12-18 can be any type of sensor, structure, and/or programming that can be used to implement the present invention.

The air flow meter 12 is configured and arranged to detect the amount of intake air of the engine 1 upstream of the position of the throttle valve 3. Thereby, the intake air amount is detected by the air flow meter 12, which outputs a detection signal indicating the amount of intake air transmitted 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 of the throttle valve 3. Thereby, the throttle position or opening degree of the throttle valve 3 is detected by the throttle sensor 13, and the throttle sensor outputs a detection signal indicating the throttle position or opening degree 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 by, for example, the crank angle of the crankshaft of the engine 1. Thereby, the engine speed is detected by the rotation 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. Thereby, the temperature of the coolant in the engine 1 is detected by the coolant sensor 15, and the coolant sensor 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. Thereby, 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 (i.e., fully release an accelerator). Thereby, 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 traveling speed (vehicle speed) of the vehicle on which the engine 1 is mounted. Thereby, the traveling speed (vehicle speed) of the vehicle is detected by the vehicle speed sensor 18, and the vehicle speed sensor 18 transmits a detection signal indicating the traveling speed (vehicle speed) of the vehicle to the engine control unit 11.

The exhaust system of the engine 1 preferably includes, in addition to other components, an exhaust manifold 19 and a catalytic converter 20 disposed in the exhaust passage 21 extending from the exhaust manifold 19. The oxygen sensor 22 is disposed in the exhaust manifold 19 or in the exhaust passage 21 at a position upstream of the position 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 the sensor or device for detecting the air-fuel ratio, an air-fuel ratio sensor 32 that can detect a wide range of air-fuel ratios may be used instead of the oxygen sensor 22 indicating the lean state. When the air-fuel ratio sensor 32 is provided, the amount by which the air-fuel ratio deviates from the target air-fuel ratio can be directly measured.

As a result, the amount of intake air can be corrected (increased) by an appropriate amount based on the amount of deviation of the air-fuel ratio.

The above is a specific structure and control process of the internal combustion engine in a specific implementation, and embodiments of the present invention include:

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 to confirm the O2FB learning value of each learning area at the altitude by confirming the altitude demarcation point at which the idle speed of the cold engine is continuously low in the previous stage plateau test, and The minimum value is set to the super-high altitude determination threshold, and the ultra-high altitude mode is set to control the internal combustion engine, specifically, the idle speed is set at the altitude, and the ignition advance angle and the intake air amount of the cold low temperature section are increased to achieve the target. The speed of the vehicle is switched to the ultra-high altitude mode according to the set value, and the vehicle switches to the ultra-high altitude mode. The low-temperature idle ignition timing is advanced, and the intake air amount is increased to reach the target speed; thus, even in the absence of the atmospheric pressure sensor, At idle speeds above 3,000 meters above sea level, the engine's target speed can also be guaranteed; at super-high altitudes, the same startability and performance as the flat ground can be ensured, and engine stall and poor driving performance can be improved.

The idle speed control device comprises: an ultra-high altitude measuring part for performing an ultra-high altitude idle speed determination of the vehicle; and a switching part for switching to an ultra-high altitude mode when the vehicle is at an ultra-high altitude, and super-high altitude mode by the super The high altitude control section performs internal combustion engine control; the ultrahigh altitude control section is used to increase the intake air amount and the ignition advance angle of the cold engine at a low temperature idle speed to reach the target rotational speed.

In the specific implementation, the following processes are included:

1. Perform an altitude test in the early stage to confirm the altitude demarcation point where the idle speed of the cold machine continues to be low;

2. Confirm the O2FB learning value of each learning area at the altitude, and set the minimum value to the ultra-high altitude determination threshold;

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

4. The late vehicle switches its super high altitude mode according to the set value.

It also includes actual vehicle determination and switching methods:

1. Perform ultra-high altitude idling judgment.

* Ultra-high altitude measurement means:

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

In order to compensate for this excessive air-fuel ratio, O2FB is corrected;

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

The fuel supply amount reduction amount at this time is stored in the ECU as the O2FB learning value; the O2FB learning value is divided into the learning values of the different regions by the throttle opening degree and the engine speed; if the O2FB learning values of the aforementioned regions exceed the altitude of 3000 m The above O2FB learning value;

Then it is judged as super high altitude.

2. Ultra high altitude control:

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

Ultra-high altitude control is specifically achieved as follows:

According to the O2FB learning value learned at the ultra-high altitude, the ultra-high altitude measurement is performed, and the ignition timing advance angle and the 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 drive value = basic drive value + ISC correction value + ISC learning value + super high altitude ISCV correction value;

Ultra-high altitude ignition correction: preset ignition correction value for each temperature of the machine;

Ultra High Altitude ISCV Correction: The ISCV correction can be preset for each temperature of the machine.

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

Claims

An idle speed control device for an internal combustion engine is an idle speed control device for an internal combustion engine mounted on a vehicle, and includes:

Ultra-high altitude measurement section for judging the vehicle's ultra-high altitude idle speed;

a switching portion for switching to an ultra-high altitude mode when the vehicle is at an ultra-high altitude, and an internal combustion engine control by an ultra-high altitude control portion in an ultra-high altitude mode;

The ultra-high altitude control section is used to increase the intake air amount and the ignition advance angle of the cold engine at a low temperature idle speed to reach the target rotational speed.
The idling speed control device for an internal combustion engine according to claim 1, further comprising: a threshold setting unit configured to perform an altitude test in the early stage to confirm an altitude demarcation point at which the idling speed of the chiller is continuously low.
The idle speed control device for an internal combustion engine according to claim 2, wherein an O2FB learning value of each learning region at the altitude boundary point is confirmed, and a minimum value thereof is set as an ultra-high altitude determination threshold.
The idle speed control device for an internal combustion engine according to claim 1, wherein said determining an ultra-high altitude idle speed of the vehicle comprises: as the altitude increases, the air density decreases, and the A/F becomes rich; The air-fuel ratio, O2FB is corrected, the amount of fuel supplied to the engine is reduced, and it is set to the correct A/F. At this time, the fuel supply reduction amount is stored in the ECU as the O2FB learning value; the O2FB learning value is opened by the throttle Degree and engine speed are divided into learning values of different regions; the altitude test is used to obtain the O2FB learning value of the ultra-high altitude demarcation point; if the O2FB learning value of each region exceeds the O2FB learning value of the ultra-high altitude demarcation point, it is judged to be super high. altitude.
The idle speed control device for an internal combustion engine according to claim 4, wherein the super-high altitude demarcation point is an altitude of 3000 m.
The idle speed control device for an internal combustion engine according to any one of claims 1 to 5, characterized in that the control of the internal combustion engine by the super-high altitude control portion includes control of an ignition timing of the internal combustion engine and correction of an ISCV drive value.
The idle speed control device for an internal combustion engine according to claim 6, wherein the ignition timing is controlled by: ignition timing = basic ignition timing + super high altitude ignition correction value; and the correction of the ISCV driving value is: ISCV driving Value = basic drive value + ISC correction value + ISC learning value + super high altitude ISCV correction value.
The idle speed control device for an internal combustion engine according to claim 7, wherein the control of the ignition timing comprises: presetting an ignition correction value for each temperature of the machine; and the correction of the ISCV driving value comprises: for each temperature of the machine Preset ISCV correction value.