阅读说明：本技术 一种车辆减排方法和装置 (Vehicle emission reduction method and device ) 是由 崔亚彬 张�浩 宋东先 郑雨佳 李婧媛 王丹 于 2020-04-01 设计创作，主要内容包括：本发明实施例提供的一种车辆减排方法和装置,应用于车辆中的发动机控制单元,所述方法包括：控制目标气缸的第一喷油器按照第一喷油相位喷射第一喷油量的燃油,所述目标气缸是处于停缸状态的气缸中需要运行的气缸；控制目标进气门进行进气,所述目标进气门是所述目标气缸中除预置数量的关闭进气门外的进气门；在所述目标气缸处于压缩进程时,控制所述目标气缸的第二喷油器按照第二喷油相位喷射第二喷油量的燃油。通过在气缸从停缸状态切换至工作状态时,通过采用部分进气门进气及在压缩进程中喷油的方式,增加了气缸内的流动,提高了燃油和空气混合的效果,显著减小了气缸燃烧的烟度。(The embodiment of the invention provides a vehicle emission reduction method and device, which are applied to an engine control unit in a vehicle, and the method comprises the following steps: controlling a first oil injector of a target cylinder to inject fuel oil with a first oil injection quantity according to a first oil injection phase, wherein the target cylinder is a cylinder needing to operate in a cylinder deactivation state; controlling a target intake valve to perform air intake, wherein the target intake valve is an intake valve except a preset number of closed intake valves in the target cylinder; and when the target cylinder is in a compression process, controlling a second fuel injector of the target cylinder to inject fuel of a second fuel injection quantity according to a second fuel injection phase. When the cylinder is switched from a cylinder deactivation state to a working state, the mode that partial air inlet valves are used for air inlet and oil injection is carried out in a compression process is adopted, the flowing in the cylinder is increased, the effect of mixing fuel oil and air is improved, and the smoke intensity of combustion of the cylinder is obviously reduced.)

1. An emission reduction method for a vehicle, characterized by being applied to an engine control unit in a vehicle, the method comprising:

controlling a first oil injector of a target cylinder to inject fuel oil with a first oil injection quantity according to a first oil injection phase, wherein the target cylinder is a cylinder needing to operate in a cylinder deactivation state;

controlling a target intake valve to perform air intake, wherein the target intake valve is an intake valve except a preset number of closed intake valves in the target cylinder;

and when the target cylinder is in a compression process, controlling a second fuel injector of the target cylinder to inject fuel of a second fuel injection quantity according to a second fuel injection phase.

2. The method according to claim 1, wherein the step of controlling the first injector of the target cylinder to inject the fuel of the first injection quantity in accordance with the first injection phase is preceded by the step of:

determining a target total intake air amount according to a target torque of the engine;

determining the target air inflow of the target cylinder according to the target air inflow total quantity and the cylinder deactivation rate;

obtaining the actual air inflow of the target cylinder according to the target air inflow and an air inflow correction coefficient, wherein the air inflow correction coefficient is determined according to the rotating speed of the engine and the target torque;

and determining a first oil injection phase and a corresponding first oil injection quantity of the first oil injector, and a second oil injection phase and a corresponding second oil injection quantity of the second oil injector of the target cylinder according to the actual air inflow.

3. The method of claim 2, wherein said step of determining a first injection phase and a corresponding first injection quantity for said first injector, a second injection phase and a corresponding second injection quantity for said second injector for said target cylinder based on said actual intake air quantity comprises:

determining the total fuel injection amount of the target cylinder according to the actual air intake amount;

and determining a first oil injection phase and a corresponding first oil injection quantity, a second oil injection phase and a corresponding second oil injection quantity according to the total oil injection quantity and the rotating speed of the engine, wherein the first oil injector and the second oil injector are oil injectors of the target cylinder.

4. The method of claim 2, wherein each cylinder of the engine has a first number of intake valves corresponding thereto, the first number being greater than the preset number, and the step of determining the target intake air amount for the target cylinder based on the target total intake air amount and the deactivation rate comprises:

determining a target number of working cylinders of the engine according to the cylinder deactivation rate;

multiplying the target number of cylinders by the first number to obtain a total number of intake valves of the engine;

subtracting the preset number from the total intake valve number to obtain a second number of target intake valves needing to be opened by the engine;

and dividing the target total intake air quantity by the second quantity and multiplying the target total intake air quantity by the first quantity to obtain the target intake air quantity of the target cylinder.

5. The method according to claim 1, wherein the step of controlling the first injector of the target cylinder to inject the fuel of the first injection quantity in accordance with the first injection phase is preceded by the step of:

when the target torque of the engine is detected to be changed, determining a cylinder deactivation rate corresponding to the changed target torque;

determining the cylinders of the engine needing to operate according to the cylinder deactivation rate;

and if the cylinder needing to be operated is in a cylinder deactivation state, determining the cylinder needing to be operated as a target cylinder.

6. An emission reduction device for a vehicle, characterized by being applied to an engine control unit in a vehicle, the device comprising:

the first oil injection module is used for controlling a first oil injector of a target cylinder to inject fuel oil with first oil injection quantity according to a first oil injection phase, and the target cylinder is a cylinder needing to operate in a cylinder deactivation state;

the air inlet module is used for controlling a target air inlet valve to carry out air inlet, and the target air inlet valve is an air inlet valve except a preset number of closed air inlet valves in the target cylinder;

and the second oil injection module is used for controlling a second oil injector of the target cylinder to inject fuel oil with a second oil injection quantity according to a second oil injection phase when the target cylinder is in a compression process.

7. The apparatus of claim 6, further comprising:

a first calculation module for determining a target total intake air amount based on a target torque of an engine;

the second calculation module is used for determining the target air inflow of the target cylinder according to the target air inflow total quantity and the cylinder deactivation rate;

the third calculation module is used for obtaining the actual air inflow of the target cylinder according to the target air inflow and an air inflow correction coefficient, and the air inflow correction coefficient is determined according to the rotating speed of the engine and the target torque;

and the fourth calculation module is used for determining a first oil injection phase and a corresponding first oil injection quantity of the first oil injector of the target cylinder, and a second oil injection phase and a corresponding second oil injection quantity of the second oil injector according to the actual air inflow.

8. The apparatus of claim 7, wherein the fourth computing module comprises:

the first calculation submodule is used for determining the total fuel injection amount of the target cylinder according to the actual air intake amount;

and the second calculation submodule is used for determining a first oil injection phase and a corresponding first oil injection quantity, a second oil injection phase and a corresponding second oil injection quantity according to the total oil injection quantity and the rotating speed of the engine, wherein the first oil injector and the second oil injector are oil injectors of the target cylinder.

9. The apparatus of claim 7, wherein each cylinder of the engine has a first number of intake valves corresponding thereto, the first number being greater than the preset number, the second calculation module comprising:

the third calculation submodule is used for determining the target number of the working cylinders of the engine according to the cylinder deactivation rate;

a fourth calculation submodule for multiplying the target number of cylinders by the first number to obtain a total number of intake valves of the engine;

the fifth calculation submodule is used for subtracting the preset number from the total number of the intake valves to obtain a second number of target intake valves needing to be opened by the engine;

and the sixth calculating submodule is used for obtaining the target air intake quantity of the target cylinder by dividing the target air intake total quantity by the second quantity and multiplying the target air intake total quantity by the first quantity.

10. The apparatus of claim 6, wherein the apparatus comprises:

the engine control device comprises a first determination module, a second determination module and a control module, wherein the first determination module is used for determining a cylinder deactivation rate corresponding to target torque after change when the target torque of an engine is detected to be changed;

the second determining module is used for determining the cylinders needing to be operated by the engine according to the cylinder deactivation rate;

and the third determining module is used for determining the cylinder needing to operate as the target cylinder if the cylinder needing to operate is in a cylinder deactivation state.

Technical Field

The invention relates to the field of automobiles, in particular to a vehicle emission reduction method and device.

Background

As an important vehicle, the automobile is widely applied to the aspects of daily life of people. However, with the increasingly severe global environmental problems and the lack of energy, the more stringent emission standards and lower fuel consumption of automobiles become the mainstream trend of the social demands for automobile engines.

The cylinder deactivation technology is widely applied to an engine technology for reducing oil consumption at the present stage, and when the engine runs at partial load, the engine stops working by cutting off fuel supply, ignition and air intake and exhaust of partial cylinders, so that the load rate of the rest working cylinders is increased, the working efficiency of the engine is improved, and the fuel consumption is reduced.

However, in this way, the cylinder which stops running does not burn in the last cycle, and because the air leakage of the inlet valve is in a negative pressure state in the cylinder and the residual flow of the last working cycle does not exist, the first combustion after restarting is caused, the flow in the cylinder is insufficient, the fuel atomization is uneven, the generated exhaust smoke is high, and the emission of the automobile does not reach the standard.

Disclosure of Invention

In view of the above, the invention aims to provide a vehicle emission reduction method and device, so as to solve the problem that fuel atomization is not uniform and exhaust smoke intensity is high when an engine cylinder in a cylinder deactivation state in the prior art runs again due to insufficient air flow in the cylinder.

In order to achieve the purpose, the technical scheme of the invention is realized as follows:

a vehicle emission reduction method applied to an engine control unit in a vehicle, the method comprising:

controlling a first oil injector of a target cylinder to inject fuel oil with a first oil injection quantity according to a first oil injection phase, wherein the target cylinder is a cylinder needing to operate in a cylinder deactivation state;

controlling a target intake valve to perform air intake, wherein the target intake valve is an intake valve except a preset number of closed intake valves in the target cylinder;

and when the target cylinder is in a compression process, controlling a second fuel injector of the target cylinder to inject fuel of a second fuel injection quantity according to a second fuel injection phase.

Optionally, before the step of controlling the first injector of the target cylinder to inject the fuel of the first injection quantity according to the first injection phase, the method further includes:

determining a target total intake air amount according to a target torque of the engine;

determining the target air inflow of the target cylinder according to the target air inflow total quantity and the cylinder deactivation rate;

obtaining the actual air inflow of the target cylinder according to the target air inflow and an air inflow correction coefficient, wherein the air inflow correction coefficient is determined according to the rotating speed of the engine and the target torque;

and determining a first oil injection phase and a corresponding first oil injection quantity of the first oil injector, and a second oil injection phase and a corresponding second oil injection quantity of the second oil injector of the target cylinder according to the actual air inflow.

Optionally, the step of determining a first fuel injection phase and a corresponding first fuel injection quantity of the first fuel injector, a second fuel injection phase and a corresponding second fuel injection quantity of the second fuel injector of the target cylinder according to the actual intake air amount includes:

determining the total fuel injection amount of the target cylinder according to the actual air intake amount;

and determining a first oil injection phase and a corresponding first oil injection quantity, a second oil injection phase and a corresponding second oil injection quantity according to the total oil injection quantity and the rotating speed of the engine, wherein the first oil injector and the second oil injector are oil injectors of the target cylinder.

Optionally, each cylinder of the engine has a first number of intake valves corresponding thereto, the first number is greater than the preset number, and the step of determining the target intake air amount of the target cylinder according to the target intake total amount and the cylinder deactivation rate includes:

determining a target number of working cylinders of the engine according to the cylinder deactivation rate;

multiplying the target number of cylinders by the first number to obtain a total number of intake valves of the engine;

subtracting the preset number from the total intake valve number to obtain a second number of target intake valves needing to be opened by the engine;

and dividing the target total intake air quantity by the second quantity and multiplying the target total intake air quantity by the first quantity to obtain the target intake air quantity of the target cylinder.

Optionally, before the step of controlling the first injector of the target cylinder to inject the fuel of the first injection quantity according to the first injection phase, the method further includes:

when the target torque of the engine is detected to be changed, determining a cylinder deactivation rate corresponding to the changed target torque;

determining the cylinders of the engine needing to operate according to the cylinder deactivation rate;

and if the cylinder needing to be operated is in a cylinder deactivation state, determining the cylinder needing to be operated as a target cylinder.

A vehicle emission reduction device for use in an engine control unit in a vehicle, the device comprising:

the first oil injection module is used for controlling a first oil injector of a target cylinder to inject fuel oil with first oil injection quantity according to a first oil injection phase, and the target cylinder is a cylinder needing to operate in a cylinder deactivation state;

the air inlet module is used for controlling a target air inlet valve to carry out air inlet, and the target air inlet valve is an air inlet valve except a preset number of closed air inlet valves in the target cylinder;

and the second oil injection module is used for controlling a second oil injector of the target cylinder to inject fuel oil with a second oil injection quantity according to a second oil injection phase when the target cylinder is in a compression process.

Optionally, the apparatus further includes:

a first calculation module for determining a target total intake air amount based on a target torque of an engine;

the second calculation module is used for determining the target air inflow of the target cylinder according to the target air inflow total quantity and the cylinder deactivation rate;

and the third calculation module is used for obtaining the actual air inflow of the target cylinder according to the target air inflow and an air inflow correction coefficient, and the air inflow correction coefficient is determined according to the rotating speed of the engine and the target torque.

And the fourth calculation module is used for determining a first oil injection phase and a corresponding first oil injection quantity of the first oil injector of the target cylinder, and a second oil injection phase and a corresponding second oil injection quantity of the second oil injector according to the actual air inflow.

Optionally, the fourth calculating module includes:

the first calculation submodule is used for determining the total fuel injection amount of the target cylinder according to the actual air intake amount;

and the second calculation submodule is used for determining a first oil injection phase and a corresponding first oil injection quantity, a second oil injection phase and a corresponding second oil injection quantity according to the total oil injection quantity and the rotating speed of the engine, wherein the first oil injector and the second oil injector are oil injectors of the target cylinder.

Optionally, each cylinder of the engine has a first number of intake valves, where the first number is greater than the preset number, and the second calculation module includes:

the third calculation submodule is used for determining the target number of the working cylinders of the engine according to the cylinder deactivation rate;

a fourth calculation submodule for multiplying the target number of cylinders by the first number to obtain a total number of intake valves of the engine;

the fifth calculation submodule is used for subtracting the preset number from the total number of the intake valves to obtain a second number of target intake valves needing to be opened by the engine;

and the sixth calculating submodule is used for obtaining the target air intake quantity of the target cylinder by dividing the target air intake total quantity by the second quantity and multiplying the target air intake total quantity by the first quantity.

Optionally, the apparatus includes:

the engine control device comprises a first determination module, a second determination module and a control module, wherein the first determination module is used for determining a cylinder deactivation rate corresponding to target torque after change when the target torque of an engine is detected to be changed;

the second determining module is used for determining the cylinders needing to be operated by the engine according to the cylinder deactivation rate;

and the third determining module is used for determining the cylinder needing to operate as the target cylinder if the cylinder needing to operate is in a cylinder deactivation state.

Compared with the prior art, the vehicle emission reduction method and the vehicle emission reduction device have the following advantages:

the embodiment of the invention provides a vehicle emission reduction method and device, which are applied to an engine control unit in a vehicle, and the method comprises the following steps: controlling a first oil injector of a target cylinder to inject fuel oil with a first oil injection quantity according to a first oil injection phase, wherein the target cylinder is a cylinder needing to operate in a cylinder deactivation state; controlling a target intake valve to perform air intake, wherein the target intake valve is an intake valve except a preset number of closed intake valves in the target cylinder; and when the target cylinder is in a compression process, controlling a second fuel injector of the target cylinder to inject fuel of a second fuel injection quantity according to a second fuel injection phase. When the cylinder is switched from a cylinder deactivation state to a working state, the mode that partial air inlet valves are used for air inlet and oil injection is carried out in a compression process is adopted, the flowing in the cylinder is increased, the effect of mixing fuel oil and air is improved, and the smoke intensity of combustion of the cylinder is obviously reduced.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate an embodiment of the invention and, together with the description, serve to explain the invention and not to limit the invention. In the drawings:

FIG. 1 is a flow chart illustrating steps of a method for reducing emissions from a vehicle, in accordance with an embodiment of the present invention;

FIG. 2 is a flow chart illustrating steps of another method for reducing emissions from a vehicle, in accordance with an embodiment of the present invention;

FIG. 3 is a flowchart illustrating steps of determining a target intake air amount in another vehicle emission reduction method according to an embodiment of the invention;

FIG. 4 is a schematic diagram of a calculation process of an actual intake air quantity of an engine in another vehicle emission reduction method according to an embodiment of the invention;

FIG. 5 is a flowchart of steps for determining a fuel injector and corresponding fuel injection quantity in another vehicle emission reduction method according to the embodiment of the invention;

FIG. 6 is a schematic diagram illustrating a process of calculating an injection quantity and an injection phase in another vehicle emission reduction method according to an embodiment of the present invention;

fig. 7 is a block diagram of a vehicle emission reduction device according to an embodiment of the present invention.

Detailed Description

It should be noted that the embodiments and features of the embodiments may be combined with each other without conflict.

In the present embodiment, the operating state of the engine is divided into the all-cylinder operating state and the random cylinder deactivation operating state. The all-cylinder working state is a state that all cylinders of the engine work; the random cylinder deactivation working state refers to that in the running process of the vehicle, the engine is controlled to work at different cylinder deactivation rates and cylinder deactivation sequences according to torque requirements under different loads, namely the vehicle can randomly control part of cylinders to stop working according to different torque requirements, so that the purpose that the engine can work with the fewest cylinders on the premise of meeting the torque requirements is achieved, and the optimal working condition oil consumption of the engine can be achieved as far as possible. The embodiment of the invention aims to solve the problem that when an engine cylinder in a cylinder deactivation state operates again, fuel oil atomization is uneven, and exhaust smoke intensity is high due to insufficient air flow in the cylinder.

The random cylinder deactivation working state can save the energy consumption of the engine, and the principle thereof is as follows:

the engine pushes the piston to rotate by consuming fuel oil in the working process, but the consumed fuel oil generates energy which is used for pushing the piston to rotate the crankshaft, and besides, part of the energy is taken away by high-temperature tail gas and cooling water, and part of the energy is used for overcoming friction resistance to do work, and in addition, part of the energy is used for overcoming pumping loss. Further, the larger the engine displacement, the greater the capacity loss due to friction and pumping loss, and therefore, the same torque is output and the smaller the energy loss of the small displacement engine to overcome friction and pumping loss is than that of the large displacement engine. Therefore, if the engine is controlled to operate at a low load, that is, when the target torque is small, the torque output by the cylinders which are partially closed and are ensured to continue operating can meet the target torque demand of the engine, and since the partial cylinders are closed, which corresponds to the reduction of the displacement of the engine, the pumping loss and the friction loss can be reduced.

It can be seen that the working principle of the random cylinder deactivation working state is equivalent to dynamically adjusting the displacement of the engine according to different working conditions, thereby realizing the reduction of the energy consumption of the engine. In order to achieve the random cylinder deactivation operating state, each cylinder of the engine should have an intake valve and an exhaust valve that can be closed or opened individually at any time.

In order to realize the random cylinder deactivation working state, each cylinder of the engine is provided with an intake valve, an exhaust valve, an oil nozzle and an ignition device which can be independently opened and closed, so that the intake and the exhaust of any cylinder can be stopped by closing the intake valve and the exhaust valve at any time, and the ignition and the oil injection are simultaneously stopped, thereby realizing the random cylinder deactivation effect.

Specifically, the control process of the random cylinder deactivation of the embodiment may include: acquiring a target torque of an engine; determining whether a random cylinder deactivation working state needs to be entered; if the random cylinder deactivation working state needs to be entered, determining the running state of the vehicle; when the running state of the vehicle is a steady state, determining a target cylinder deactivation rate corresponding to the target torque according to the target torque; when the running state of the vehicle is transient, determining a target cylinder deactivation rate corresponding to the target torque according to the target torque and the acceleration and deceleration state of the vehicle; the acceleration and deceleration state comprises an acceleration state and a deceleration state, and the target cylinder deactivation rate corresponding to the acceleration state is greater than the target cylinder deactivation rate corresponding to the deceleration state; and controlling the engine to work according to the target cylinder deactivation rate.

The method comprises the following steps that different cylinder deactivation rates correspond to different outer characteristic curve graphs, the outer characteristic curve graphs are determined by torque and engine rotating speed, and a preset optimal oil consumption area is arranged in the outer characteristic curve graphs and is obtained in advance according to actual use. Because the outer characteristic curve chart is determined by the torque and the engine rotating speed, and the preset optimal oil consumption area is arranged in the outer characteristic curve chart, after the condition that the engine needs to enter the random cylinder deactivation working state is determined, the corresponding target cylinder deactivation rate is determined according to the target torque and the current rotating speed, so that the target torque is in the optimal oil consumption area of the outer characteristic curve chart, the target torque can be input into the engine, and the engine can work in the optimal oil consumption state on the premise of outputting the target torque, so that the oil consumption is saved.

In addition, a cylinder deactivation table corresponding to the target cylinder deactivation rate can be obtained according to the preset corresponding relation between the cylinder deactivation rate and the cylinder deactivation table; the cylinder deactivation table is preset with the number of cylinders deactivated in a plurality of working cycles and the cylinder sequence of cylinder deactivation. And controlling the engine to work according to the number of cylinders deactivated in a plurality of working cycles in the cylinder deactivation table and the cylinder sequence of cylinder deactivation. On the basis of meeting the target cylinder deactivation rate, the engine can be controlled to perform cylinder deactivation according to a cylinder deactivation table. The cylinder deactivation table may take into account noise, vibration, and harshness factors to minimize vibration when the engine is operating at the same cylinder deactivation rate.

From the above, in the process of engine operation, the random cylinder deactivation rate of the engine changes along with the working load, so that the cylinder of the engine can be switched between the cylinder deactivation state and the working state according to different cylinder deactivation rates, and at the moment, if the cylinder in the cylinder deactivation state is switched to the working state again, the air flow in the cylinder is insufficient, the fuel atomization is uneven, and the exhaust smoke intensity is large.

The present invention will be described in detail below with reference to the embodiments with reference to the attached drawings.

Referring to fig. 1, a flow chart of steps of a method for reducing emissions from a vehicle according to an embodiment of the present invention is shown.

A vehicle emission reduction method applied to an engine control unit in a vehicle may include:

step 101, controlling a first fuel injector of a target cylinder to inject fuel of a first fuel injection quantity according to a first fuel injection phase, wherein the target cylinder is a cylinder needing to operate in a cylinder deactivation state.

In the present embodiment, in the existing vehicle engine, the injector associated with the cylinder can inject fuel at different times during the operation of the cylinder by adjusting the injection phase, for example, the injector can inject fuel at a certain time during the intake process, the compression process, the power process, the exhaust process, etc. of the cylinder by adjusting the injection phase. Because the target cylinder is in a cylinder deactivation state before, the air flow in the cylinder is insufficient, the effect of fuel and air mixing after oil injection is influenced, and the smoke intensity of exhaust is high. Here, the first fuel injection may be performed by the first fuel injector in the target cylinder according to the first fuel injection phase before the intake valve is opened, so that the fuel of the first fuel injection amount and the air may be uniformly mixed by the intake air flow, and how to perform the second fuel injection will be described in detail later. The first injection phase may be an injection phase at which the fuel consumption rate is the lowest, which is experimentally measured under different rotation speed conditions according to actual use of the engine. It can be understood that the first fuel injector is suitable for different engines and vehicles, and the injection phase of the first fuel injector is different at different rotating speeds of the engine, and can be determined by experiments according to actual needs. For example: the intake process can be used as a first fuel injection phase to allow air to be mixed with fuel immediately when entering the target cylinder, so that the fuel mixed with air directly enters the target cylinder.

And 102, controlling a target intake valve to perform air intake, wherein the target intake valve is the intake valve except for a preset number of closed intake valves in the target cylinder.

In the embodiment of the invention, in order to further increase the flow in the target cylinder in the process of switching the target cylinder from the cylinder deactivation state to the working state, the preset number of closed intake valves in the closed target cylinder are adopted, and the targets except the closed intake valves in the target cylinder are used for intake, so that the flow speed of the intake airflow of the intake valves is increased, the airflow flow in the target cylinder is further improved, the fuel and the air can be mixed more fully, and the exhaust smoke degree of the engine is reduced. The preset number can be specifically determined according to the actual requirement and the number of the intake valves in each cylinder in the engine, for example: when there are two intake valves in each cylinder of an engine of a certain vehicle, single valve intake may be employed by closing one of the two intake valves in a target cylinder to be operated in an intake process to improve the airflow flow in the target cylinder.

And 103, controlling a second oil injector of the target cylinder to inject fuel oil with a second oil injection quantity according to a second oil injection phase when the target cylinder is in a compression process.

In the embodiment of the invention, in order to further improve the air flow in the target cylinder, when the target cylinder is in the compression process, the second injector of the target cylinder injects the fuel with the second fuel injection quantity into the target cylinder according to the second fuel injection phase, so that the flow in the target cylinder is further increased by utilizing the kinetic energy of the fuel injection, and the smoke of combustion in the target cylinder is reduced. It can be understood that the second fuel injection phase of the second fuel injector is different at different rotating speeds of the engine, and the second fuel injection phase can be determined by experiments according to actual needs. For example: the target cylinder compression schedule may be used as the second injection phase of the second injector, and fuel may be directly injected into the cylinder during the compression schedule to increase flow in the target start. It should be noted that the second fuel injector and the first fuel injector may be the same fuel injector or different fuel injectors, and here, the second fuel injector and the first fuel injector are only used to distinguish two fuel injection processes, and may be specifically determined according to actual requirements and the number of fuel injectors included in an engine cylinder, and here, the second fuel injector and the first fuel injector are not specifically limited.

In summary, the vehicle emission reduction method provided by the embodiment of the invention is applied to an engine control unit in a vehicle, and the method includes: controlling a first oil injector of a target cylinder to inject fuel oil with a first oil injection quantity according to a first oil injection phase, wherein the target cylinder is a cylinder needing to operate in a cylinder deactivation state; controlling a target intake valve to perform air intake, wherein the target intake valve is an intake valve except a preset number of closed intake valves in the target cylinder; and when the target cylinder is in a compression process, controlling a second fuel injector of the target cylinder to inject fuel of a second fuel injection quantity according to a second fuel injection phase. When the cylinder is switched from a cylinder deactivation state to a working state, the mode that partial air inlet valves are used for air inlet and oil injection is carried out in a compression process is adopted, the flowing in the cylinder is increased, the effect of mixing fuel oil and air is improved, and the smoke intensity of combustion of the cylinder is obviously reduced.

Referring to FIG. 2, a flow chart of steps of another method for reducing emissions from a vehicle in accordance with an embodiment of the present invention is shown.

Another vehicle emission reduction method applied to an engine control unit in a vehicle, the method comprising:

in step 201, when a change in the target torque of the engine is detected, a cylinder deactivation rate corresponding to the changed target torque is determined.

In the embodiment of the invention, each cylinder of the vehicle engine is provided with an intake valve and an exhaust valve which can be controlled independently, and any intake valve and any exhaust valve in the cylinder can be opened or closed at any time, so that any cylinder in the engine can be flexibly controlled to carry out intake and exhaust, and ignition and oil injection at any moment can be realized by controlling a spark plug and an oil injector. When the work load of the engine changes, the target torque and the minimum fuel consumption region required to be output by the engine change. Therefore, in order to ensure that the fuel consumption of the vehicle is low, the target torque of the engine can be adjusted by adjusting the cylinder deactivation rate, the target torque corresponding to different cylinder deactivation rates is gradually reduced along with the reduction of the cylinder deactivation rate, and the torque corresponding to the optimal fuel consumption is also gradually reduced. When the engine control unit detects that the target torque of the engine needs to be adjusted, the corresponding cylinder deactivation rate can be inquired through a torque-cylinder deactivation rate line graph. The torque-deactivation rate line graph may be obtained by performing an experiment according to a preset fuel consumption standard for an engine in an actually used vehicle, and different engines have different attributes, so that the torque-deactivation rate line graph is different according to different types of vehicles and different types of engines.

And 202, determining the cylinders of the engine needing to be operated according to the cylinder deactivation rate.

In the embodiment of the invention, after the cylinder deactivation rate of the engine which needs to be switched is determined, the cylinder deactivation state which is in the cylinder deactivation state before is determined according to the cylinder deactivation strategy corresponding to the cylinder deactivation rate, and at the moment, the target cylinder needs to be switched to the working state. The cylinder deactivation strategy refers to the strategy aiming at different cylinder deactivation rates, such as: the engine of a certain vehicle has 4 cylinders, the cylinder deactivation rate is 50%, only two cylinders on the inner side in the engine are operated, when the cylinder deactivation rate needs to be switched to 0%, two outer cylinders in the engine which are in the cylinder deactivation state before need to be switched to the working state, and the two outer cylinders are determined as target cylinders.

And 203, if the cylinder needing to operate is in a cylinder deactivation state, determining that the cylinder needing to operate is a target cylinder.

In the embodiment of the invention, when an engine in a vehicle is in cylinder deactivation operation, the load of a working cylinder is directly related to the fuel consumption rate, when the load of the working cylinder is overlarge, the fuel consumption is increased, and at the moment, the cylinder deactivation rate is adjusted to switch a target cylinder in the cylinder deactivation state into the working state, so that the load of each cylinder is reduced, and the fuel consumption rate is reduced. And correspondingly, the cylinder deactivation rate switched according to the requirement can determine the target cylinder required to be switched from the cylinder deactivation state to the working state.

In step 204, a target total intake air amount is determined based on the target torque of the engine.

In the embodiment of the invention, in order to ensure the exhaust treatment efficiency of the three-way catalyst in the engine, the mixing ratio of the air intake quantity and the fuel in the cylinder is generally ensured to reach 14.7:1, the output power of the engine can be determined by multiplying the target torque by the engine speed, the required total fuel injection quantity is obtained by dividing the output power by the fuel consumption rate of the engine, and finally the target total air intake quantity of the engine under the ideal state can be obtained by dividing the total fuel injection quantity by 14.7.

Step 205, determining the target air intake quantity of the target cylinder according to the target air intake total quantity and the cylinder deactivation rate.

In the embodiment of the invention, the cylinders in the working state can suck the air sucked by the engine through the total air inlet pipe into the cylinders through the respectively butted air inlet valves according to different cylinder deactivation rates, so that the air inlet amount sucked by the target cylinder can be determined according to the different cylinder deactivation rates.

Optionally, each cylinder of the engine corresponds to a first number of intake valves, and the first number is greater than the preset number; referring to fig. 3, the step 205 may include:

and step 2051, determining the target number of the working cylinders of the engine according to the cylinder deactivation rate.

Step 2052, multiplying the target number of cylinders by the first number to obtain a total number of intake valves for the engine.

And step 2053, subtracting the preset number from the total intake valve number to obtain a second number of target intake valves for the engine to open.

And step 2054, dividing the target total intake air amount by the second quantity and multiplying the target total intake air amount by the first quantity to obtain the target intake air amount of the target cylinder.

In the embodiment of the invention, the target intake air amount of the target cylinder can be calculated specifically by the following formula (1).

The V is_{General assembly}Indicates the target total intake air, V_TargetRefers to the target air inflow of a target cylinder, a refers to the target working cylinder number of the engine, and n refers to_{General assembly}Each hair of the fingerA first number of engine-butted intake valves, n_{Close off}Refers to a preset number of closed valves that require the target cylinder.

It will be appreciated that the engine passes through a x n_{General assembly}-n_{Close off}The target total intake air amount taken in by each intake valve is theoretically allocated equally to each cylinder, including the target cylinder.

And step 206, obtaining the actual air inflow of the target cylinder according to the target air inflow and an air inflow correction coefficient, wherein the air inflow correction coefficient is determined according to the rotating speed of the engine and the target torque.

In the embodiment of the invention, the temperatures of the cylinders in the engine are different due to the difference of the target torque and the rotating speed value of the engine, in a normal condition, the temperature in the cylinder in a cylinder deactivation state is lower, the airflow is more inclined to flow to a low-temperature region, so the target torque and the rotating speed value are different, the air suction capacity of the air inlet valve of the target cylinder is different, and the actual air suction amount of the target cylinder is obviously higher than that when the whole air inlet valve is opened because the target cylinder adopts a part of the air inlet valve for air suction. Therefore, the method can be experimentally measured according to different rotating speeds and different torques of the engine, and reflects the air intake quantity correction coefficient of the relation between the target air intake quantity and the actual air intake quantity under different rotating speeds and torques, so as to obtain the mapping relation between the rotating speed, the torque and the air intake quantity correction coefficient, so that the actual air intake quantity of the target cylinder can be obtained by combining the target air intake quantity with the air intake quantity correction coefficient, and further, a corresponding air intake quantity correction coefficient table can be generated according to the mapping relation between the rotating speed, the torque and the air intake quantity correction coefficient for subsequent query. The air inflow correction coefficient is obtained by experimental tests on the target air inflow and the actual air inflow of the engine under the conditions of different engine rotating speeds and torques, and an air inflow correction coefficient table can be obtained by summarizing the air inflow correction coefficients. It can be understood that the product of the torque and the rotating speed of the engine is equal to the output power of the engine, and the output power and the air intake quantity of the engine are in nonlinear correlation, so that the actual running quantity and the target air intake quantity have certain gaps under different rotating speeds and torques of the engine.

In practical applications, referring to a schematic diagram of an actual intake air quantity calculation process of an engine shown in fig. 4, each cylinder of the engine is provided with a double intake valve, after a target torque A1 of the engine is determined, the output power of the engine is obtained according to the target torque A1, then the total fuel injection quantity is obtained according to the output power, and then the target intake air quantity A3 is obtained according to the total fuel injection quantity, the fuel consumption rate and the effective fuel mixing ratio of the three-way catalyst; calculating the number aA4 of the working cylinders currently operated according to the cylinder deactivation rate A2, and dividing the target total air intake amount A3 by a-0.5 to obtain the target air intake amount A5 of the target cylinder; an air intake quantity correction coefficient table (including the correlation among the target torque, the rotating speed and the air intake quantity correction coefficient of the engine) is inquired according to the target torque and the engine rotating speed, an air intake quantity correction coefficient A6 is obtained, and the actual air intake quantity A7 of the target cylinder is obtained by combining the air intake quantity correction coefficient A6 with the target air intake quantity A5. Further, the other-cylinder intake air amount A9 may be obtained by subtracting the actual intake air amount A7 of the target cylinder from the target total intake air amount A3 of the engine and dividing by a-1.

And step 207, determining a first oil injection phase and a corresponding first oil injection quantity of the first oil injector of the target cylinder, and a second oil injection phase and a corresponding second oil injection quantity of the second oil injector according to the actual air inflow amount.

Optionally, referring to fig. 5, step 207 may include:

step 2071, determining the total amount of fuel injected into the target cylinder based on the actual intake air amount.

In the embodiment of the invention, in order to ensure the exhaust treatment efficiency of the three-way catalyst in the engine, the mixing ratio of air and fuel is generally ensured to be 14.7:1, so that the total injection amount of a target cylinder can be obtained by dividing the actual air inflow by 14.7 under the condition that the actual air inflow is known.

And 2072, determining a first oil injection phase and a corresponding first oil injection quantity, a second oil injection phase and a corresponding second oil injection quantity according to the total oil injection quantity and the rotating speed of the engine, wherein the first oil injector and the second oil injector are oil injectors of the target cylinder.

In the embodiment of the invention, the first injection phase and the corresponding first injection quantity, the second injection phase and the corresponding second injection quantity can be specifically used for different engines and vehicles, and experiments are carried out according to different total injection quantities and the engine rotating speed to detect the fuel consumption rates corresponding to different first injection phases and first injection quantities, second injection phases and second injection quantities, so as to determine the mapping relation among the first injection phase, the first injection quantity, the second injection phase, the second injection quantity and the total injection quantity with the highest fuel consumption rate at different injection quantities and engine rotating speeds, and generate the corresponding injection management table for subsequent query according to the mapping relation among the first injection phase, the first injection quantity, the second injection phase, the second injection quantity and the total injection quantity. The first injection phase and the second injection phase refer to injection timings of the injectors, and injection is performed at a certain timing in an intake process, a compression process, a power process, an exhaust process, and the like of the engine, for example.

In practical application, referring to a schematic diagram of a calculation process of an oil injection amount and an oil injection phase shown in fig. 6, an oil injection total amount B2 is obtained by dividing an actual intake air amount B1 of a target cylinder by an effective gas mixing ratio 14.7 of a three-way catalyst, and then an oil injection management table B7 (the oil injection management table B7 includes a first oil injection phase and a corresponding first oil injection amount, a second oil injection phase and a corresponding mapping relation between the second oil injection amount and the oil injection total amount) is consulted according to the oil injection total amount B2 and a rotation speed value B3 of an engine to obtain the first oil injection amount, the second oil injection amount B4, the corresponding first oil injection phase B5 and the second oil injection phase B6.

And 208, controlling a first fuel injector of a target cylinder to inject fuel with a first fuel injection quantity according to the first fuel injection phase, wherein the target cylinder is a cylinder needing to be operated in the cylinder deactivation state.

The step 101 may refer to the detailed description of the step, which is not described herein again.

And step 209, controlling a target air inlet valve to perform air inlet, wherein the target air inlet valve is an air inlet valve except a preset number of closed air inlet valves in the target cylinder.

The step 102 may refer to the detailed description of the step, which is not repeated herein.

And step 210, controlling a second fuel injector of the target cylinder to inject fuel of a second fuel injection quantity according to a second fuel injection phase when the target cylinder is in a compression stroke.

The step 103 can refer to the detailed description of the step, which is not repeated herein.

In summary, another vehicle emission reduction method provided by the embodiment of the invention is applied to an engine control unit in a vehicle, and the method includes: controlling a first oil injector of a target cylinder to inject fuel oil with a first oil injection quantity according to a first oil injection phase, wherein the target cylinder is a cylinder needing to operate in a cylinder deactivation state; controlling a target intake valve to perform air intake, wherein the target intake valve is an intake valve except a preset number of closed intake valves in the target cylinder; and when the target cylinder is in a compression process, controlling a second fuel injector of the target cylinder to inject fuel of a second fuel injection quantity according to a second fuel injection phase. When the cylinder is switched from a cylinder deactivation state to a working state, the mode that partial air inlet valves are used for air inlet and oil injection is carried out in a compression process is adopted, the flowing in the cylinder is increased, the effect of mixing fuel oil and air is improved, and the smoke intensity of combustion of the cylinder is obviously reduced.

Referring to fig. 7, the vehicle emission reduction device provided by the embodiment of the invention is applied to an engine control unit in a vehicle, and the device comprises:

a vehicle emission reduction device for use in an engine control unit in a vehicle, the device comprising:

the first fuel injection module 301 is configured to control a first fuel injector of a target cylinder to inject fuel of a first fuel injection amount according to a first fuel injection phase, where the target cylinder is a cylinder that needs to be operated among cylinders in a cylinder deactivation state.

An intake module 302 controls intake of a target intake valve, which is an intake valve of the target cylinder excluding a preset number of closed intake valves.

And the second oil injection module 303 is configured to control a second oil injector of the target cylinder to inject fuel oil of a second oil injection amount according to a second oil injection phase when the target cylinder is in a compression process.

Optionally, the apparatus further includes:

a first calculation module 304 determines a target total intake air amount based on a target torque of an engine.

And a second calculating module 305 for determining the target air intake amount of the target cylinder according to the target total air intake amount and the cylinder deactivation rate.

A third calculation module 306, configured to obtain an actual intake air amount of the target cylinder according to the target intake air amount and an intake air amount correction coefficient, where the intake air amount correction coefficient is determined according to the rotation speed of the engine and the target torque.

A fourth calculating module 307, configured to determine a first fuel injection phase and a corresponding first fuel injection amount of the first fuel injector, a second fuel injection phase and a corresponding second fuel injection amount of the second fuel injector of the target cylinder according to the actual intake air amount.

Optionally, the fourth calculating module 307 includes:

a first calculation submodule 3071 for determining the total amount of fuel injection for the target cylinder based on the actual intake air amount.

And the second calculation submodule 3072 is configured to determine a first oil injection phase and a corresponding first oil injection quantity, a second oil injection phase and a corresponding second oil injection quantity according to the total oil injection quantity and the rotation speed of the engine, where the first oil injector and the second oil injector are oil injectors of the target cylinder.

Optionally, each cylinder of the engine has a first number of intake valves corresponding thereto, the first number being greater than the preset number, and the second calculating module 305 includes:

a third calculation submodule 3051 for determining a target number of cylinders of said engine based on a cylinder deactivation rate.

A fourth calculation submodule 3052, configured to multiply the first number by the target number of cylinders, to obtain a total number of intake valves of the engine.

And the fifth calculation submodule 3053, configured to subtract the preset number from the total number of intake valves to obtain a second number of target intake valves that the engine needs to be opened.

A sixth calculating submodule 3054, configured to divide the target total intake air amount by the second number and multiply by the first number to obtain a target intake air amount for the target cylinder.

Optionally, the apparatus includes:

the first determination module 308 is configured to determine a cylinder deactivation rate corresponding to a changed target torque when a change in the target torque of the engine is detected.

A second determination module 309 is configured to determine a cylinder in which the engine needs to operate based on the cylinder deactivation rate.

The third determining module 310 is configured to determine that the cylinder needing to be operated is a target cylinder if the cylinder needing to be operated is in a cylinder deactivation state.

In summary, an emission reduction device for a vehicle provided by an embodiment of the present invention is applied to an engine control unit in a vehicle, and the device includes: a first calculation module for determining a target total intake air amount based on a target torque of an engine; the second calculation module is used for determining the target air inflow of the target cylinder according to the target air inflow total quantity and the cylinder deactivation rate; and the third calculation module is used for obtaining the actual air inflow of the target cylinder according to the target air inflow and an air inflow correction coefficient, and the air inflow correction coefficient is determined according to the rotating speed of the engine and the target torque. And the fourth calculation module is used for determining a first oil injection phase and a corresponding first oil injection quantity of the first oil injector of the target cylinder, and a second oil injection phase and a corresponding second oil injection quantity of the second oil injector according to the actual air inflow. When the cylinder is switched from a cylinder deactivation state to a working state, the mode that partial air inlet valves are used for air inlet and oil injection is carried out in a compression process is adopted, the flowing in the cylinder is increased, the effect of mixing fuel oil and air is improved, and the smoke intensity of combustion of the cylinder is obviously reduced.

It is clear to those skilled in the art that, for convenience and brevity of description, the specific working processes of the above-described systems, apparatuses and units may refer to the corresponding processes in the foregoing method embodiments, and are not described herein again.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents and improvements made within the spirit and principle of the present invention are intended to be included within the scope of the present invention.

The above description is only for the specific embodiments of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art can easily conceive of the changes or substitutions within the technical scope of the present invention, and all the changes or substitutions should be covered within the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.