阅读说明：本技术 一种gdi发动机的喷油控制策略 (Fuel injection control strategy of GDI engine ) 是由 张健 王艳锋 于 2021-08-18 设计创作，主要内容包括：本发明提供一种GDI发动机的喷油控制策略,涉及发动机技术领域。该GDI发动机的喷油控制策略,包括以下具体步骤：S1、发动机EMS根据需求扭矩、实际进气量、空燃比等参数计算总的燃油量m；S2、设定设定的第5次喷油占总喷油量的占比为r5,根据r5计算第5次喷油量为m5＝m×r5,或者直接设定喷油量m5＝mL,其中,r5的设定范围为0-1；S3、计算前4次喷油量总和：M＝m-m5。本发明,汽油直喷发动机在冲程内可实现多次喷油,通过改变不同喷油的喷油比例和喷油角度,可实现发动机在一个冲程内进行1次到最多5次的喷油,继而可用于抑制发动机超级爆震并降低机油稀释率。(The invention provides an oil injection control strategy of a GDI engine, and relates to the technical field of engines. The fuel injection control strategy of the GDI engine comprises the following specific steps: s1, calculating the total fuel quantity m by the engine EMS according to the parameters such as the required torque, the actual air intake quantity, the air-fuel ratio and the like; s2, setting the ratio of the set 5 th fuel injection to the total fuel injection to be r5, calculating the 5 th fuel injection to be m 5-mxr 5 according to r5, or directly setting the fuel injection to be m 5-mL, wherein the set range of r5 is 0-1; s3, calculating the sum of the oil injection quantity of the previous 4 times: M-M5. According to the invention, the gasoline direct injection engine can realize multiple times of oil injection in a stroke, and the engine can realize 1-5 times of oil injection in one stroke by changing the oil injection proportion and the oil injection angle of different oil injections, so that the engine can be used for inhibiting engine super knocking and reducing the engine oil dilution rate.)

1. A fuel injection control strategy of a GDI engine is characterized in that: the method comprises the following specific steps:

s1, calculating the total fuel quantity m by the engine EMS according to the parameters such as the required torque, the actual air intake quantity, the air-fuel ratio and the like;

s2, setting the ratio of the set 5 th fuel injection to the total fuel injection to be r5, calculating the 5 th fuel injection to be m 5-mxr 5 according to r5, or directly setting the fuel injection to be m 5-mL, wherein the set range of r5 is 0-1;

s3, calculating the sum of the oil injection quantity of the previous 4 times: M-M5;

s4, setting the proportion of the 1 st fuel injection to the sum of the previous 4 fuel injections to be r1, and calculating the 1 st fuel injection to be m1-m 5-x r1 according to r1, wherein the set range of r1 is 0-1;

s5, setting the ratio of the 2 nd fuel injection to the sum of the first 4 fuel injections to be r2, and calculating the 2 nd fuel injection according to r2 to be m 2-min ((m-m5) x r2, (m-m5-m1)), wherein the setting range of r2 is 0-1;

s6, whether the 4 th fuel injection is needed or not can be selected according to the requirement, if the selection is not needed, the 4 th fuel injection quantity is equal to 0, and the 3 rd fuel injection quantity is calculated by the method that m3 is m-m5-m1-m 2; and if the selection is needed, the 3 rd fuel injection quantity is equal to the 4 th fuel injection quantity, and m3 is m4 (m-m5-m1-m 2)/2.

2. The fuel injection control strategy of the GDI engine as set forth in claim 1, wherein: the method also comprises the step of setting 5 injection angles which represent the pulse widths of 5 injection phases of the engine in one cycle stroke, wherein the 1 st injection angle, the 2 nd injection angle, the 3 rd injection angle and the 5 th injection angle are all based on a compression top dead center TDC and the 4 th injection angle is based on the 3 rd injection angle.

3. The fuel injection control strategy of the GDI engine as set forth in claim 2, wherein: the 1 st injection angle represents a phase distance from a compression top dead center to a 1 st injection start angle or end angle, and a phase range is set: 0-360CA degrees.

4. The fuel injection control strategy of the GDI engine as set forth in claim 3, wherein: the 2 nd injection angle represents a phase distance from a compression top dead center to a start angle or an end angle of the 2 nd injection, and a phase range is set: 0-360CA degrees.

5. The fuel injection control strategy of the GDI engine as set forth in claim 4, wherein: the 3 rd injection angle represents a phase distance from a compression top dead center to a start angle or an end angle of the 3 rd injection, and a phase range is set: 0-360CA degrees.

6. The fuel injection control strategy of the GDI engine as set forth in claim 5, wherein: the 5 th injection angle represents a phase distance from a compression top dead center to a 5 th injection start angle or end angle, and a phase range is set: 0-360CA degrees.

7. The fuel injection control strategy of the GDI engine as set forth in claim 6, wherein: said 4 th injection start angle is calculated from the phase difference Δ Φ between the 3 rd injection end angle and the 4 th injection start angle, Δ Φ setting the phase range: 0-360CA degrees.

Technical Field

The invention relates to the technical field of engines, in particular to an oil injection control strategy of a GDI engine.

Background

In order to reduce the knocking of the engine and improve the low-end torque of the engine, the current mainstream gasoline engine development adopts an in-stroke 2-3 times oil injection technology, but still suffers from the problems of super knocking and engine oil dilution, after the super knocking occurs, the engine can be damaged in a short time due to huge in-cylinder detonation pressure and abnormally high combustion temperature, and the engine oil dilution is mainly realized because the oil injection of the direct injection engine is directly carried out in a cylinder, if an oil bundle is directly sprayed on the wall of the cylinder to be mixed with the engine oil and is scraped after a piston ring moves downwards, the oil mixed in the oil sump is more and more fuel oil along with the accumulation of time, so that the engine oil dilution phenomenon is caused, and the viscosity of the engine oil is reduced due to the engine oil dilution, damaging the running parts of the engine.

Research shows that super knocking and engine oil dilution of an engine can be effectively reduced if an oil injection strategy can be realized more than 4 times, so that the engine can be effectively protected, and the development of a multi-injection strategy is always a difficult problem which troubles the development of a GDI engine, so that in order to inhibit super knocking and reduce the risk of engine oil dilution, a control strategy for realizing multi-injection of the GDI engine in a stroke is needed to be developed.

Disclosure of Invention

Technical problem to be solved

Aiming at the defects of the prior art, the invention provides an oil injection control strategy of a GDI engine, which can effectively reduce super knocking and engine oil dilution of the engine, thereby effectively protecting the engine.

(II) technical scheme

In order to achieve the purpose, the invention is realized by the following technical scheme: a fuel injection control strategy of a GDI engine comprises the following specific steps:

s1, calculating the total fuel quantity m by the engine EMS according to the parameters such as the required torque, the actual air intake quantity, the air-fuel ratio and the like;

s2, setting the ratio of the set 5 th fuel injection to the total fuel injection to be r5, calculating the 5 th fuel injection to be m 5-mxr 5 according to r5, or directly setting the fuel injection to be m 5-mL, wherein the set range of r5 is 0-1;

s3, calculating the sum of the oil injection quantity of the previous 4 times: M-M5;

s4, setting the proportion of the 1 st fuel injection to the sum of the previous 4 fuel injections to be r1, and calculating the 1 st fuel injection to be m1-m 5-x r1 according to r1, wherein the set range of r1 is 0-1;

s5, setting the ratio of the 2 nd fuel injection to the sum of the first 4 fuel injections to be r2, and calculating the 2 nd fuel injection according to r2 to be m 2-min ((m-m5) x r2, (m-m5-m1)), wherein the setting range of r2 is 0-1;

s6, whether the 4 th fuel injection is needed or not can be selected according to the requirement, if the selection is not needed, the 4 th fuel injection quantity is equal to 0, and the 3 rd fuel injection quantity is calculated by the method that m3 is m-m5-m1-m 2; and if the selection is needed, the 3 rd fuel injection quantity is equal to the 4 th fuel injection quantity, and m3 is m4 (m-m5-m1-m 2)/2.

Preferably, the method further comprises setting 5 injection angles to represent the pulse width of 5 injection phases of the engine in one cycle stroke, wherein the 1 st, 2 nd, 3 rd and 5 th injection angles are all based on the compression top dead center TDC, and the 4 th injection angle is based on the 3 rd injection angle.

Preferably, the 1 st injection angle represents a phase distance from a compression top dead center to a start angle or an end angle of the 1 st injection, and the phase range is set as follows: 0-360CA degrees.

Preferably, the 2 nd injection angle represents a phase distance from a compression top dead center to a start angle or an end angle of the 2 nd injection, and the phase range is set as follows: 0-360CA degrees.

Preferably, the 3 rd injection angle represents a phase distance from a compression top dead center to a start angle or an end angle of the 3 rd injection, and the phase range is set as follows: 0-360CA degrees.

Preferably, the 5 th injection angle represents a phase distance from a compression top dead center to a start angle or an end angle of the 5 th injection, and the phase range is set as follows: 0-360CA degrees.

Preferably, said 4 th injection start angle is calculated from the phase difference Δ Φ between the 3 rd injection end angle and the 4 th injection start angle, Δ Φ setting the phase range: 0-360CA degrees.

(III) advantageous effects

The invention provides an oil injection control strategy of a GDI engine. The method has the following beneficial effects:

according to the invention, the gasoline direct injection engine can realize multiple times of oil injection in a stroke, and the engine can realize 1-5 times of oil injection in one stroke by changing the oil injection proportion and the oil injection angle of different oil injections, so that the engine can be used for inhibiting engine super knocking and reducing the engine oil dilution rate.

Drawings

FIG. 1 is a schematic flow diagram of the present invention;

FIG. 2 is a schematic view of the fuel injection angle setting of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Example (b):

as shown in fig. 1, the embodiment of the invention provides a fuel injection control strategy of a GDI engine, and S1, an engine EMS calculates a total fuel quantity m according to parameters such as required torque, actual air intake quantity, air-fuel ratio and the like;

s2, setting the ratio of the set 5 th fuel injection to the total fuel injection to be r5, calculating the 5 th fuel injection to be m 5-mxr 5 according to r5, or directly setting the fuel injection to be m 5-mL, wherein the set range of r5 is 0-1;

s3, calculating the sum of the oil injection quantity of the previous 4 times: M-M5;

s4, setting the proportion of the 1 st fuel injection to the sum of the previous 4 fuel injections to be r1, and calculating the 1 st fuel injection to be m1-m 5-x r1 according to r1, wherein the set range of r1 is 0-1;

s5, setting the ratio of the 2 nd fuel injection to the sum of the first 4 fuel injections to be r2, and calculating the 2 nd fuel injection according to r2 to be m 2-min ((m-m5) x r2, (m-m5-m1)), wherein the setting range of r2 is 0-1;

s6, whether the 4 th fuel injection is needed or not can be selected according to the requirement, if the selection is not needed, the 4 th fuel injection quantity is equal to 0, and the 3 rd fuel injection quantity is calculated by the method that m3 is m-m5-m1-m 2; and if the selection is needed, the 3 rd fuel injection quantity is equal to the 4 th fuel injection quantity, and m3 is m4 (m-m5-m1-m 2)/2.

As shown in FIG. 2, the present invention also includes a method of setting 5 injection angles, where 5 rectangles in FIG. 2 represent the pulse width of 5 injection phases of an engine in one cycle stroke, where the 1 st, 2 nd, 3 rd and 5 th injection angles are all referenced to compression top dead center TDC, and the 4 th injection angle is referenced to the 3 rd injection angle;

the 1 st injection angle represents a phase distance from the compression top dead center to the 1 st injection start angle or end angle, and a phase range is set: 0-360CA °;

the 2 nd injection angle represents a phase distance from the compression top dead center to the start angle or the end angle of the 2 nd injection, and a phase range is set: 0-360CA °;

the 3 rd injection angle represents a phase distance from the compression top dead center to the 3 rd injection start angle or end angle, and a phase range is set: 0-360CA °;

the 5 th injection angle represents a phase distance from the compression top dead center to the 5 th injection start angle or end angle, and a phase range is set: 0-360CA °

The 4 th injection start angle is calculated from the phase difference Δ Φ between the 3 rd injection end angle and the 4 th injection start angle, Δ Φ setting the phase range: 0-360CA degrees.

Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.