WO2016119554A1 - Method for controlling super-knocks of direct-injection supercharged gasoline engine - Google Patents

Abstract

Disclosed is a method for controlling super-knocks of a direct-injection supercharged gasoline engine, which is able to control super-knocks efficiently. The control method comprises: identifying cylinders in which super-knocks are triggered due to mixed gas pre-ignition triggered by the spontaneous combustion of the lubricating oil entering the cylinders, and identifying same as super-knock cylinders; putting off the last oil injection of the super-knock cylinders to the compression stroke, and enabling the crank angle when forming mixed gas for combustion to not be ahead of the crank angle corresponding to pre-ignition by controlling the timing of the last oil injection. The control method in the present invention is relatively simple; as long as the timing of oil injection for individual super-knock cylinders can be controlled, operational reliability is relatively high; and the number of super-knock cylinders identified can be one or more than one. Experiments show that the control method mentioned above is able to control super-knocks efficiently.

Description

一种直喷增压汽油机超级爆震的控制方法Control method for super knocking of direct injection supercharged gasoline engine

本申请要求于2015年01月27日提交中国专利局、申请号为201510041093.7、发明名称为“一种直喷增压汽油机超级爆震的控制方法”的中国专利申请的优先权，其全部内容通过引用结合在本申请中。This application claims the priority of the Chinese Patent Application filed on January 27, 2015, the Chinese Patent Office, Application No. 201510041093.7, entitled "Control Method for Super-Blasting of Direct-Injected Supercharged Gasoline Engine", the entire contents of which are The citations are incorporated herein by reference.

技术领域Technical field

本发明涉及直喷增压汽油发动机燃烧控制技术领域，特别是涉及一种直喷增压汽油机超级爆震的控制方法。The invention relates to the technical field of combustion control of a direct injection supercharged gasoline engine, in particular to a control method for super knocking of a direct injection supercharged gasoline engine.

背景技术Background technique

直喷增压技术是汽油机小型化、节能减排的一种有效方法，由于均匀计量混合气的燃烧和排放比稀薄混合气分层燃烧更容易控制，采用均质计量燃烧的直喷增压汽油机日益成为小型增压汽油机市场的主流。Direct injection supercharging technology is an effective method for miniaturization, energy saving and emission reduction of gasoline engines. Since the combustion and emission of uniform metering mixture is easier to control than the stratified combustion of lean mixture, the direct injection supercharged gasoline engine with homogeneous metering combustion It is increasingly becoming the mainstream of the small supercharged gasoline engine market.

针对上述类型的发动机，在低速高增压工况时会遇到一种由进入气缸的润滑油自燃引发的混合气提前点火导致的强烈爆震现象。由于爆震时的压力振荡可达到正常燃烧时气缸爆发压力的数量级，这种不正常燃烧被称为超级爆震。For the above-mentioned type of engine, in the low-speed high-pressurization condition, a strong knocking phenomenon caused by the pre-ignition of the mixed gas caused by the spontaneous combustion of the lubricating oil entering the cylinder is encountered. Since the pressure oscillation at the time of knocking can reach the order of the cylinder burst pressure at the time of normal combustion, this abnormal combustion is called super knock.

实践中，超级爆震主要发生在发动机转速在2500转以下以及平均有效压力高于16bar的低速大负荷工况，其频繁发生时可造成火花塞和排气门过热烧蚀，活塞熔顶、穿孔或拉缸，以及连杆弯曲等发动机零部件的失效。超级爆震产生的高频压力波会清理掉附着在燃烧室壁面上的引发提前点火的残余润滑油或积碳，这种自清洁作用使得超级爆震具有随机性和不持续性。In practice, super-knocking mainly occurs in low-speed and high-load conditions with an engine speed below 2,500 rpm and an average effective pressure of more than 16 bar. When it occurs frequently, it can cause overheating and ablation of the spark plug and exhaust valve, and the piston is topped, perforated or Pull cylinders, as well as failure of engine components such as connecting rods. The high-frequency pressure waves generated by the super-knocking clean up the residual lubricating oil or carbon deposits that cause pre-ignition on the wall of the combustion chamber. This self-cleaning effect makes the super-knocking random and unsustainable.

因提前点火系润滑油自燃所为，不能像控制普通爆震那样通过推迟火花塞点火时间的方式来控制超级爆震，事实上，火花塞点火时间越迟，超级爆震就越强烈；再者，引发提前点火的润滑油的来源以及点火位置尚不十分清楚，完全消除缸内附着在燃烧室壁面上的润滑油也不现实。因此，目前还没有对超级爆震进行有效控制的方法。Because the pre-ignition is the self-ignition of the lubricating oil, it is not possible to control the super-knocking by delaying the ignition timing of the spark plug as in the control of ordinary knocking. In fact, the later the ignition time of the spark plug, the stronger the super-knocking is. The source of the pre-ignited lubricating oil and the ignition position are not fully understood, and it is not realistic to completely eliminate the lubricating oil adhering to the wall surface of the combustion chamber. Therefore, there is currently no way to effectively control super knock.

因此，如何设计一种直喷增压汽油机超级爆震的控制方法，以便有效 控制超级爆震，是本领域技术人员目前亟需解决的技术问题。Therefore, how to design a super-knocking super-knocking control method for direct injection supercharged gasoline engine Controlling super-knocking is a technical problem that is urgently needed to be solved by those skilled in the art.

发明内容Summary of the invention

本发明的目的是提供一种直喷增压汽油机超级爆震的控制方法，能够有效控制超级爆震。The object of the present invention is to provide a control method for super-knocking of a direct-injection supercharged gasoline engine, which can effectively control super-knocking.

为解决上述技术问题，本发明提供一种直喷增压汽油机超级爆震的控制方法，包括以下步骤：In order to solve the above technical problem, the present invention provides a control method for super-squeezing of a direct-injection supercharged gasoline engine, comprising the following steps:

1)识别因进入缸内的润滑油自燃引发提前点火而产生超级爆震气缸，并将其标识为超级爆震气缸；1) Identifying the super-detonation cylinder generated by the pre-ignition caused by the spontaneous combustion of the lubricating oil entering the cylinder, and marking it as a super-detonation cylinder;

2)将所述超级爆震气缸的最后一次喷油推迟到压缩冲程，并通过控制最后一次喷油的时间，使得形成可供燃烧的混合气时的曲轴转角不早于提前点火所对应的曲轴转角。2) deferring the last injection of the super detonation cylinder to the compression stroke, and by controlling the time of the last injection, so that the crank angle when forming the combustible mixture is not earlier than the crankshaft corresponding to the pre-ignition Corner.

本发明的控制方法，在识别出某个气缸因发生润滑油自燃引发的提前点火而发生超级爆震时，将其作为超级爆震气缸进行单独的喷油控制，以便有效控制超级爆震。在发动机运行过程中，每个循环的喷油可以分为若干次完成，由于前几次喷油所形成混合气的浓度在着火的下界限，因而需要的点火能量大且不容易形成稳定的火焰，所以，混合气稳定燃烧所要求的物理条件由最后一次喷油控制。由于提前点火发生在压缩冲程，而如果最后一次喷油发生在进气冲程，在由进气到压缩的过程中，很有可能形成可供燃烧的混合气，并在进入气缸内的润滑油发生自燃时被点燃，引发混合气的提前点火；基于上述原理，可以将最后一次喷油推迟至压缩冲程，并控制具体地喷油时间，以便使可供燃烧的混合气仅在火花塞点火之前形成，从而避免混合气被过早点燃。可见，本发明的控制方法较为简单，仅需对个别超级爆震气缸的喷油时间进行控制即可，操作可靠性较高；被识别出的超级爆震气缸可以是一个或多于一个。试验证明，上述控制方法能够有效地控制超级爆震。The control method of the present invention performs a separate fuel injection control as a super-detonation cylinder when it is recognized that a certain cylinder has a super-detonation due to pre-ignition caused by spontaneous combustion of the lubricating oil, so as to effectively control super-knocking. During the operation of the engine, the injection of each cycle can be divided into several times. Because the concentration of the mixture formed by the previous injections is below the lower limit of ignition, the required ignition energy is large and it is not easy to form a stable flame. Therefore, the physical conditions required for stable combustion of the mixture are controlled by the last injection. Since the pre-ignition occurs in the compression stroke, and if the last injection occurs in the intake stroke, in the process from the intake to the compression, it is highly probable that a mixture of combustion can be formed and the lubricating oil entering the cylinder occurs. When self-ignited, it is ignited, causing pre-ignition of the mixture; based on the above principle, the last injection can be postponed to the compression stroke, and the specific injection time can be controlled so that the combustible mixture is formed only before the spark plug is ignited. Thereby avoiding the mixture being prematurely ignited. It can be seen that the control method of the present invention is relatively simple, and only needs to control the injection time of the individual super detonation cylinders, and the operation reliability is high; the identified super detonation cylinders may be one or more than one. Tests have shown that the above control method can effectively control super-knocking.

可选地，所述步骤1)具体包括：判断是否存在因进入缸内的润滑油自燃引发提前点火而产生超级爆震的气缸，如果是，则将其标识为超级爆震气缸，并执行所述步骤2)，如果否，则终止。 Optionally, the step 1) specifically includes: determining whether there is a cylinder that generates super-detonation due to pre-ignition caused by spontaneous combustion of the lubricating oil entering the cylinder, and if so, identifying it as a super-detonation cylinder, and executing the Step 2), if no, terminate.

可选地，在所述步骤2)之后还包括以下步骤：Optionally, after the step 2), the following steps are further included:

3)判断超级爆震是否被抑制，如果是，则终止，如果否，则执行步骤4)；3) Determine whether the super knock is suppressed, if yes, terminate, if not, proceed to step 4);

4)增加各气缸每次喷油的喷油量，使得最后一次喷油所形成混合气的浓度对应于最大火焰速度，并按照所述步骤2)控制各气缸最后一次喷油的时间。4) Increasing the injection amount of each injection of each cylinder, so that the concentration of the mixture formed by the last injection corresponds to the maximum flame speed, and controlling the time of the last injection of each cylinder according to the step 2).

可选地，在所述步骤4)之后还包括以下步骤：Optionally, after the step 4), the following steps are further included:

5)判断超级爆震是否被抑制，如果是，则终止，如果否，则执行步骤6)；5) Determine whether the super knock is suppressed, if yes, terminate, if not, proceed to step 6);

6)对发动机实施限扭，以跳出超级爆震区运行。6) Limit the torque of the engine to jump out of the super detonation zone.

可选地，在所述步骤6)中，对发动机降扭升速，以便其在超级爆震区外以相同的输出功率运行。Optionally, in the step 6), the engine is ramped up so that it operates at the same output power outside of the super-knock zone.

可选地，在所述步骤6)中，发动机降扭升速运行至少500个工作循环或30秒，然后终止。Optionally, in the step 6), the engine is operated at a reduced speed of at least 500 working cycles or 30 seconds, and then terminated.

可选地，在所述步骤3)和所述步骤5)中，如果超级爆震被抑制，则按照所述步骤2)或所述步骤4)继续执行至少500个工作循环或至少30秒，然后再终止。Optionally, in the step 3) and the step 5), if the super knock is suppressed, proceeding to perform at least 500 working cycles or at least 30 seconds according to the step 2) or the step 4), Then terminate.

可选地，在所述步骤2)和所述步骤4)中，每循环喷油分至少三次进行，最后一次喷油的喷油量为25％～33％。Optionally, in the step 2) and the step 4), the fuel injection is performed at least three times per cycle, and the fuel injection amount of the last injection is 25% to 33%.

附图说明DRAWINGS

图1为本发明所提供直喷增压汽油机超级爆震的控制方法在一种具体实施方式中的流程示意图；1 is a schematic flow chart of a method for controlling super-knocking of a direct-injection supercharged gasoline engine according to a specific embodiment of the present invention;

图2为本发明所提供控制方法在第一种具体实施方式中的原理示意图；2 is a schematic diagram of the principle of the control method provided by the present invention in the first embodiment;

图3为本发明所提供控制方法在第二种具体实施方式中的原理示意图；3 is a schematic diagram of the principle of the control method provided by the present invention in a second specific embodiment;

图4为汽油混合气的火焰速度和点火能量与过量空气系数的关系示意图； Figure 4 is a schematic diagram showing the relationship between the flame speed and the ignition energy of the gasoline mixture and the excess air ratio;

图5为直喷增压汽油机的***结构示意图。Fig. 5 is a schematic structural diagram of a system of a direct injection supercharged gasoline engine.

图1-5中：In Figure 1-5:

增压器压缩机1、中冷器2、电子节气门3、进气歧管4、高压共轨供油***5、发动机6、多孔喷油器7、气缸8、排气歧管9、增压器废气涡轮机10、发动机排气氧传感器11、三元催化器12。 Supercharger compressor 1, intercooler 2, electronic throttle 3, intake manifold 4, high pressure common rail fuel supply system 5, engine 6, porous injector 7, cylinder 8, exhaust manifold 9, increase The compressor exhaust gas turbine 10, the engine exhaust oxygen sensor 11, and the three-way catalyst 12.

具体实施方式detailed description

本发明的核心是提供一种直喷增压汽油机超级爆震的控制方法，能够有效控制超级爆震。The core of the invention is to provide a control method for super-squeezing of a direct-injection supercharged gasoline engine, which can effectively control super-knocking.

以下结合附图和具体实施例，对本发明的控制方法进行具体说明，以便本领域技术人员更加准确地理解本发明。The control method of the present invention will be specifically described below in conjunction with the drawings and specific embodiments, so that those skilled in the art can understand the present invention more accurately.

诚如背景技术所述，直喷增压汽油发动机在低速大负荷工况下，曲轴箱通风再循环带入气缸内的润滑油颗粒在扫气时会滞留在燃烧室壁面上；在燃烧室的壁面温度及压缩后期的气体温度作用下，滞留在燃烧室壁面上的润滑油颗粒会蒸发并在其颗粒表面达到着火条件，产生和柴油颗粒类似的自燃，自燃的润滑油进一步引发混合气的提前点火。由于点火时间过早，且燃烧室的壁面上存在其它点火源，未燃区的混合气会迅速达到着火条件而引发比常规爆震强度大得多的超级爆震。As described in the background art, in a low-speed supercharged gasoline engine, the lubricating oil particles brought into the cylinder by the crankcase ventilation recirculation are retained on the combustion chamber wall during scavenging; Under the action of wall temperature and gas temperature in the late stage of compression, the lubricating oil particles retained on the wall surface of the combustion chamber will evaporate and reach the ignition condition on the surface of the particles, producing spontaneous combustion similar to that of diesel particles. The self-igniting lubricating oil further induces the advance of the mixture. ignition. Since the ignition time is too early and there are other sources of ignition on the wall of the combustion chamber, the mixture in the unburned zone will quickly reach the ignition condition and cause a super knock that is much greater than the conventional knock strength.

目前，引发提前点火的润滑油的来源以及点火位置尚不十分清楚，而完全消除气缸内附着在燃烧室壁面上的润滑油也不现实。针对上述情况，本发明着重于减弱或消除引发爆震的条件，从超级爆震产生的机理入手，抑制超级爆震。超级爆震在机理上同于普通爆震，即由于未燃区的可燃混合气在被点燃的混合气的火焰到达之前发生自燃所致。提前点火发生的越早，发生自燃的区域就越大，爆震也就越强烈。鉴于超级爆震对发动机的破坏力较大，如何抑制超级爆震成为开发直喷增压汽油机必须考虑的问题。At present, the source of the lubricating oil that causes the pre-ignition and the ignition position are not fully understood, and it is not realistic to completely eliminate the lubricating oil adhering to the wall surface of the combustion chamber. In view of the above, the present invention focuses on attenuating or eliminating the conditions that cause knocking, starting from the mechanism of super-knocking and suppressing super-knocking. The super knock is mechanically identical to the normal knock, that is, the combustible mixture in the unburned zone is caused by spontaneous combustion before the flame of the ignited mixture arrives. The earlier the pre-ignition occurs, the larger the area where spontaneous combustion occurs and the stronger the knocking. In view of the great destructive power of the super detonation on the engine, how to suppress the super detonation has become a problem that must be considered when developing a direct injection supercharged gasoline engine.

针对上述技术问题，本发明避开难以控制的点火源，即避开缸内润滑油的自燃，从被点燃的对象入手，通过控制形成可供燃烧的混合气的时间，控制超级爆震。In view of the above technical problems, the present invention avoids an ignition source that is difficult to control, that is, avoids self-ignition of the lubricating oil in the cylinder, starts from the object to be ignited, and controls super-knocking by controlling the time of forming the mixture for combustion.

如图1所示，本发明的控制方法具体可以包括如下步骤： As shown in FIG. 1 , the control method of the present invention may specifically include the following steps:

S1：采集预先标定的提前点火窗口的信号，即爆震传感器监控发动机振动，检测到的发动机振动信号由滤波器滤掉预先标定的提前点火窗口以外的信号，即因润滑油自燃引发提前点火时所对应的曲轴转角范围以外的发动机振动信号；S1: collecting a signal of the pre-calibrated pre-ignition window, that is, the knock sensor monitors the engine vibration, and the detected engine vibration signal is filtered by the filter to filter out signals other than the pre-calibrated pre-ignition window, that is, when the pre-ignition is triggered by the spontaneous combustion of the lubricating oil Engine vibration signal outside the corresponding crank angle range;

S2：比较各气缸在提前点火窗口内爆震传感器检测到的发动机振动信号和预先标定过的发动机正常燃烧时的振动信号的差异，判断是否存在因进入缸内的润滑油自燃引发提前点火而产生超级爆震的气缸，如果否，则终止，如果是，则将其标识为超级爆震气缸，并执行步骤S3；S2: comparing the difference between the engine vibration signal detected by the knock sensor in the pre-ignition window and the vibration signal detected by the pre-calibrated engine during normal combustion, and determining whether there is a pre-ignition caused by spontaneous combustion of the lubricating oil entering the cylinder. Super knocking cylinder, if not, terminate, if it is, then identify it as a super detonation cylinder, and perform step S3;

S3：将超级爆震气缸的最后一次喷油时间推迟至压缩冲程，并控制最后一次喷油的时间，以使可供燃烧的混合气仅在火花塞点火之前形成，即可供燃烧的混合气形成的曲轴转角全面覆盖提前点火窗口，避免可供燃烧的混合气在提前点火窗口内被缸内的润滑油点燃；S3: Deferring the last injection time of the super detonation cylinder to the compression stroke, and controlling the time of the last injection, so that the combustible mixture is formed only before the ignition of the spark plug, that is, the mixture for combustion can be formed. The crank angle fully covers the pre-ignition window to prevent the combustible mixture from being ignited by the lubricating oil in the cylinder in the pre-ignition window;

S4：判断超级爆震是否被抑制，如果是，则终止，如果否，则执行步骤S5；S4: determining whether the super knock is suppressed, if yes, then terminating, if not, proceeding to step S5;

S5：将各气缸的最后一次喷油时间均推迟至压缩冲程、且对各气缸最后一次喷油的时间进行控制，使得提前点火窗口被覆盖在各气缸形成可供燃烧的混合气所需的曲轴转角范围内；同时，增加各气缸多次喷油中每次喷油的喷油量，使得最后一次喷油所形成的混合气浓度对应于最大火焰速度，以增加提前点火所需的点火能量和滞后期，即使被点燃后的混合气以最大火焰速度扫过未燃区，最大程度地减少火焰到达前未燃混合气自行着火的区域，通过对混合气燃烧的控制进一步抑制超级爆震；S5: delaying the last injection time of each cylinder to the compression stroke, and controlling the time of the last injection of each cylinder, so that the pre-ignition window is covered by the crankshaft required for each cylinder to form a mixture for combustion. In the corner range; at the same time, increase the fuel injection amount of each injection in each cylinder, so that the concentration of the mixture formed by the last injection corresponds to the maximum flame speed to increase the ignition energy required for pre-ignition and During the lag period, even if the ignited mixture sweeps through the unburned zone at the maximum flame speed, the area where the unburned mixture is self-ignited before the flame reaches is minimized, and the super-knock is further suppressed by the control of the combustion of the mixed gas;

S6：判断超级爆震是否被抑制，如果是，则终止，如果否，则执行步骤S7；S6: determining whether the super knock is suppressed, if yes, then terminate, if not, proceed to step S7;

S7：对发动机实施限扭，以便其跳出超级爆震区运行，并按照没有超级爆震情况下的喷油策略进行正常的喷油控制。S7: The engine is limited in twisting so that it can jump out of the super-knocking zone and perform normal fuel injection control according to the fuel injection strategy without super-shock.

进一步，步骤S4和步骤S6中，如果超级爆震被抑制，可以在步骤S3或步骤S5的控制策略下继续运行500个工作循环左右，或者继续运行30秒，以有效防止超级爆震的再次发生，然后再停止超级爆震的控制，回到无超级爆震的正常控制模式，终止整个控制过程。至于控制的时间可以根 据需要增减，不限于上述30秒或500个工作循环。Further, in step S4 and step S6, if the super knock is suppressed, it can continue to run for about 500 working cycles under the control strategy of step S3 or step S5, or continue to run for 30 seconds to effectively prevent the re-crash from happening again. Then stop the super knock control, return to the normal control mode without super knock, and terminate the entire control process. As for the time of control, you can root Increase or decrease as needed, not limited to the above 30 seconds or 500 work cycles.

同理，在步骤S7之后，还可以增加步骤S8，继续在步骤S7中的限扭控制策略下运行500个工作循环左右或者运行30秒，然后解除限扭，回到正常控制模式，终止整个控制过程。也就是说，在超级爆震被抑制的情况下，均可以在原有策略下继续运行500个工作循环左右，或者继续运行30秒，以有效防止超级爆震的再次发生，即按照步骤S8执行，只是继续运行时的控制策略不同。Similarly, after step S7, step S8 may be further added, and the operation of the limit-torque control strategy in step S7 is continued for about 500 working cycles or for 30 seconds, then the limit is released, the normal control mode is returned, and the entire control is terminated. process. That is to say, in the case that the super knock is suppressed, it can continue to run for about 500 working cycles under the original strategy, or continue to run for 30 seconds, so as to effectively prevent the re-occurrence of the super-knock, that is, according to step S8, Just the control strategy is different when you continue to run.

在步骤S1之前通常涉及预先在发动机台架上标定的提前点火窗口。在对提前点火窗口进行标定时，可以根据爆震传感器的检测信号，将提前点火发生的相应曲轴转角范围并在前后各加以一定的曲轴转角余度后标定为提前点火窗口，以便对爆震传感器所检测到的发动机振动信号通过滤波器滤波，仅对该窗口范围内的发动机振动信号进行监测，并根据检测结果进行相应的控制。发动机的普通爆震一般发生在压缩上死点后曲轴转角为10-50度之间，该曲轴转角范围即所谓的爆震窗口(即普通爆震发生时对应的曲轴转角范围)。为对普通爆震进行控制，发动机通常设有爆震传感器，以便发动机控制单元ECU根据发生爆震的曲轴转角对点火提前角进行调整，对爆震进行控制。爆震窗口只要覆盖爆震发生的曲轴转角范围即可，不能定义的太大，否则会增加ECU处理数据和做出反应的时间。同理，鉴于进入缸内的润滑油可能会在压缩上死点之前的某个曲轴转角发生自燃并引发提前点火从而改变发动机的振动，故可以将从发生提前点火时所对应的曲轴转角范围作为提前点火窗口，以便ECU在提前点火窗口内通过爆震传感器对因提前点火导致的发动机振动变化进行监测，以控制因提前点火引发的超级爆震。识别提前点火的爆震传感器可以是特别设置的也可以是控制火花塞点火时间的常规爆震传感器。采用常规爆震传感器同时控制普通爆震和提前点火引发的超级爆震时，必须在提前点火窗口和爆震窗口对其分别进行标定。本文中的提前点火窗口通常对应于压缩上死点前10-30度的曲轴转角范围，而爆震窗口则通常设在压缩上死点后10-50度的曲轴转角范围。Prior to step S1, a pre-ignition window previously calibrated on the engine gantry is typically involved. When the pre-ignition window is calibrated, according to the detection signal of the knock sensor, the corresponding crank angle range in which the pre-ignition occurs can be calibrated to a pre-ignition window after a certain crank angle allowance before and after, so as to be the knock sensor. The detected engine vibration signal is filtered by the filter, and only the engine vibration signal in the window range is monitored, and corresponding control is performed according to the detection result. The normal knocking of the engine generally occurs between 10 and 50 degrees after the compression top dead center. The crank angle range is the so-called knock window (ie, the corresponding crank angle range when the ordinary knock occurs). In order to control the ordinary knock, the engine is usually provided with a knock sensor, so that the engine control unit ECU adjusts the ignition advance angle according to the crank angle at which the knock occurs, and controls the knock. As long as the knocking window covers the range of the crank angle of the knocking, it cannot be defined too much, otherwise it will increase the time for the ECU to process the data and react. Similarly, since the lubricating oil entering the cylinder may spontaneously ignite at a certain crank angle before the compression top dead center and cause pre-ignition to change the vibration of the engine, the range of the crank angle corresponding to the occurrence of the pre-ignition may be used as The ignition window is advanced so that the ECU can monitor the engine vibration change caused by the pre-ignition by the knock sensor in the pre-ignition window to control the super knock caused by the pre-ignition. The knock sensor that identifies the pre-ignition may be a special set or a conventional knock sensor that controls the ignition timing of the spark plug. When a conventional knock sensor is used to simultaneously control the super knock caused by normal knocking and pre-ignition, it must be separately calibrated in the pre-ignition window and the knock window. The pre-ignition window herein generally corresponds to a range of crank angles of 10-30 degrees before compression top dead center, while the knock window is typically set at a crank angle range of 10-50 degrees after compression top dead center.

可以理解，在发动机控制单元ECU的内存中有提前点火窗口及滤波范 围的相关信息时，可以省去步骤S1，而直接执行步骤S2。同时，在步骤S2中，可以默认提前点火和超级爆震的相关性，此时，只需识别出所述发生提前点火的气缸，将其标识为超级爆震气缸，然后再执行相应的控制策略即可。It can be understood that there is an early ignition window and a filtering fan in the memory of the engine control unit ECU. When the related information is surrounded, step S1 can be omitted, and step S2 is directly executed. Meanwhile, in step S2, the correlation between the pre-ignition and the super-knocking may be defaulted. At this time, it is only necessary to identify the cylinder in which the pre-ignition is generated, identify it as a super-detonation cylinder, and then execute the corresponding control strategy. Just fine.

当然，在省去步骤S1时，在步骤S3中，可以直接控制最后一次喷油的时间，以便形成可供燃烧的混合气时的曲轴转角不早于提前点火所对应的曲轴转角，即在可能的提前点火点之后形成可燃的混合气，以避免混合气被自燃的润滑油提前点燃。此处所述的提前点火所对应的曲轴转角在每次发生时有所不同，但最迟和最早的提前点火角通常应落入上述提前点火窗口覆盖范围；因ECU必须根据内存中事先标定并储存的相关信息对爆震传感器信号进行比较来判断发动机燃烧是否正常。Of course, when step S1 is omitted, in step S3, the time of the last injection can be directly controlled, so that the crank angle when forming the combustible mixture is not earlier than the crank angle corresponding to the pre-ignition, that is, possible A flammable mixture is formed after the pre-ignition point to prevent the mixture from being pre-ignited by the self-igniting lubricating oil. The crank angle corresponding to the pre-ignition described here differs each time it occurs, but the latest and earliest pre-ignition angle should normally fall within the above-mentioned pre-ignition window coverage; since the ECU must be pre-calibrated according to the memory and The stored related information compares the knock sensor signals to determine if the engine is burning properly.

在步骤S3中，当推迟最后一次喷油时间至压缩冲程时，最后一次喷油的冷却作用和形成均匀的可供燃烧的混合气需要时间向压缩上死点靠近，消弱了混合气被缸内润滑油提前点燃的条件；通过压缩过程的喷油冷却及控制混合气在压缩过程后期的形成时间，使得提前点火的时间尽可能靠近压缩上死点，以降低提前点火对发动机的损伤，甚至可以使润滑油尚不能点燃混合气时完成火花塞点火，实现正常燃烧，从而避免发生超级爆震。即使润滑油提前将混合气点燃，由于提前点火点被大幅度推迟，经大量试验证明，此时发生的提前点火仅会有限度地提高缸压，不会引发超级爆震。In step S3, when the last injection time is postponed to the compression stroke, the cooling effect of the last injection and the formation of a uniform mixture for combustion require time to approach the compression top dead center, weakening the mixture cylinder. The condition that the internal lubricating oil is ignited in advance; the cooling of the injection through the compression process and the control of the formation time of the mixed gas in the later stage of the compression process, so that the pre-ignition time is as close as possible to the compression top dead center, so as to reduce the damage of the pre-ignition to the engine, even It can make the spark plug ignite when the lubricating oil can not ignite the mixture, and achieve normal combustion, so as to avoid super-knocking. Even if the lubricating oil ignites the mixture in advance, since the pre-ignition point is largely delayed, a large number of tests have proved that the pre-ignition occurring at this time only increases the cylinder pressure to a limit and does not cause super-knocking.

还可以理解，步骤S4-S8均可以省略，而采用步骤S3中的方法控制发动机工作若干个工作循环，如缸内引发提前点火的润滑油在超级爆震发生时已被大部分清除，最终也能实现对爆震的有效控制。当然，在超级爆震较为强烈的情况下，增加步骤S4进行判断，并根据判断结果改变相应的控制策略，按照步骤S5执行增加喷油浓度的控制策略，能够提高爆震控制的可靠性，以便快速有效地控制超级爆震的再次发生，减小对发动机的损伤。同理，在步骤S5之后还可以增加步骤S6进行判断，并在采用增加喷油浓度和推迟最后一次喷油时间均不能有效控制爆震时，按照步骤S7进行限扭控制，可以对车辆驾驶性影响最小的方式跳出爆震区，使其回到正常运行的控制模式，以期减小车辆驾驶人员对发动机超级爆震控制 策略的敏感性。It can also be understood that steps S4-S8 can be omitted, and the method in step S3 is used to control the engine to work for several working cycles. For example, the lubricating oil that initiates pre-ignition in the cylinder has been mostly removed during the super-knocking, and finally Can achieve effective control of knocking. Of course, in the case where the super knock is relatively strong, the step S4 is added to make a judgment, and the corresponding control strategy is changed according to the judgment result, and the control strategy of increasing the fuel injection concentration is performed according to the step S5, so that the reliability of the knock control can be improved, so that Quickly and effectively control the recurrence of super knock and reduce damage to the engine. Similarly, after step S5, step S6 may be added to perform the determination, and when the knocking is not effectively controlled by increasing the fuel injection concentration and delaying the last injection time, the torque limiting control may be performed according to step S7, and the vehicle driving performance may be performed. The least influential way to jump out of the knock zone, returning it to normal operation control mode, in order to reduce vehicle driver's super knock control of the engine The sensitivity of the strategy.

具体地，在步骤S7中，对发动机实施限扭的同时可以进行升速，以使得发动机在相同功率下运行，也就是说，发动机跳出了超级爆震区，以相同的输出功率运行，保证车辆正常运行。由于在低速高负荷运行时，当低速扭矩下降到一定程度，发动机将不再需要通过扫气来提高增压器压缩机的流量以达到低速扭矩所需的增压要求，也就不会使曲轴箱通风再循环带入缸内的润滑油随从进气道到排气道的短路气缸的扫气流动而滞留在燃烧室壁面上并形成可能的提前点火源，从点火源以及燃烧条件等方面限制气缸内的燃烧，从而跳出超级爆震区运行。同时，降扭可能产生的功率下降可以通过提高转速来补偿，最终使得发动机沿等功率线按降扭升速的方法在提前点火区外(即跳出超级爆震区)运行。沿等功率线跳出超级爆震区的方法对变速器换挡策略影响最小，因而该降扭策略对整车的驾驶性影响最小。请进一步结合图2-4，对本发明控制方法的原理进行进一步的详细说明。Specifically, in step S7, the engine can be speed-adjusted while the engine is being operated at the same power, that is, the engine jumps out of the super-detonation zone and operates at the same output power to ensure the vehicle. normal operation. Since the low speed torque drops to a certain level during low speed and high load operation, the engine will no longer need to pass the scavenging gas to increase the flow rate of the supercharger compressor to achieve the supercharging demand required for the low speed torque, and thus the crankshaft will not be used. The lubricating oil brought into the tank by the tank ventilation recirculation is retained on the wall surface of the combustion chamber with the scavenging flow of the short-circuited cylinder from the intake passage to the exhaust passage and forms a possible pre-ignition source, which is limited from the ignition source and combustion conditions. The combustion inside the cylinder, which jumps out of the super detonation zone. At the same time, the power drop that can be generated by the twisting can be compensated by increasing the speed, and finally the engine is operated outside the pre-ignition zone (ie, jumping out of the super-explosion zone) along the equal power line by the method of increasing the speed of the twist. The method of jumping out of the super-knocking zone along the equal power line has the least influence on the transmission shifting strategy, and thus the twist-down strategy has the least impact on the driving performance of the whole vehicle. The principle of the control method of the present invention will be further described in detail with reference to FIGS. 2-4.

实践中，发动机供油***向气缸的喷油通常每循环只有一次，且在进气冲程中完成。但在发生超级爆震的发动机转速区，即低于2500转时，由于进气冲程对应的时间长，可以通过提高喷油压力，缩短一次连续喷油的时间，使喷油分若干次进行。本文所述的若干是指数量不确定的多个，通常为三个或三个以上。本文以三次喷油为例进行说明。本文所述的混合气在无特殊说明的情况下，均指可供燃烧的混合气，通常为均匀混合。In practice, the injection of fuel from the engine fuel supply system to the cylinder is typically only once per cycle and is completed during the intake stroke. However, in the engine speed region where super knocking occurs, that is, below 2500 rpm, since the intake stroke corresponds to a long time, it is possible to shorten the time of one continuous injection by increasing the injection pressure, so that the injection is performed several times. A number referred to herein refers to a plurality of uncertainties, usually three or more. This article uses three injections as an example to illustrate. The gas mixture described herein, unless otherwise specified, refers to a mixture that is combustible, usually in a homogeneous mixture.

如图2所示，在无超级爆震时，三次喷油均可以在进气冲程完成，各次喷油占总喷油量的比例分别可以控制在35％、32％～40％、25％～33％；缸内混合气的过量空气系数随着三次喷油的变化分别为2.86、1.33～1.5、1.0。其中，对第一次喷油量的限制主要是考虑到活塞离开进气上死点不久，油束穿透长度不能太大，否则会和活塞产生干涉。由于不同的发动机活塞形状以及缸内湍流强度的不同，合适的喷油时间以及第二次喷油的喷油量可以通过实验最终确定。当第二次喷油量设定为32％时，对应的过量空气系数为1.5，其为混合气着火的下界限，因而不能形成稳定的火焰。也就是说，只有在完成第三次喷油后，才能够使对应的过量空气系数达到 1.0，形成可供燃烧的计量混合气，因此，本发明通过控制第三次喷油的时间控制混合气的形成时间，进而控制超级爆震。As shown in Figure 2, in the absence of super knock, the three injections can be completed in the intake stroke, and the ratio of each injection to the total injection can be controlled at 35%, 32% to 40%, 25%, respectively. ~33%; the excess air ratio of the in-cylinder mixture is 2.86, 1.33 to 1.5, 1.0 with three injections. Among them, the restriction on the first injection quantity is mainly considering that the piston will not penetrate too much the length of the oil beam to pass through the top dead center of the intake air, otherwise it will interfere with the piston. Due to the different shape of the engine piston and the turbulence intensity in the cylinder, the appropriate injection time and the amount of fuel injected for the second injection can be determined experimentally. When the second injection amount is set to 32%, the corresponding excess air ratio is 1.5, which is the lower limit of the mixture ignition, and thus a stable flame cannot be formed. In other words, the corresponding excess air ratio can be achieved only after the third injection is completed. 1.0, forming a metered mixture for combustion, therefore, the present invention controls the formation time of the mixture by controlling the time of the third injection, thereby controlling super-knocking.

为了提高混合质量，在发动机供油***条件许可时，应尽量增加第二次喷油量，比如可以将其提高到40％，对应的过量空气系数为1.33，可使第三次喷油降为25％，有利于第三次喷油的蒸发和混合，以便形成较为均匀的混合气。In order to improve the mixing quality, the second injection quantity should be increased as much as possible when the engine fuel supply system conditions permit. For example, it can be increased to 40%, and the corresponding excess air ratio is 1.33, which can reduce the third injection to 25% is beneficial to the evaporation and mixing of the third injection to form a relatively uniform mixture.

发动机电控单元ECU可以根据接收到的各气缸爆震传感器信号分析在各气缸对应的提前点火窗口内发动机振动是否正常，并通过比较ECU的内存中储存的发动机正常燃烧时的振动信号判定是否发生提前点火。The engine electronic control unit ECU can analyze whether the engine vibration is normal in the pre-ignition window corresponding to each cylinder according to the received cylinder knock sensor signals, and determine whether the occurrence occurs by comparing the vibration signals of the normal combustion of the engine stored in the memory of the ECU. Ignition ahead.

当ECU在某一气缸的提前点火窗口内识别出提前点火时，将该气缸标记为发生超级爆震的气缸，并将该气缸的第三次喷油推迟至压缩冲程，且控制第三次喷油的时间，使得计量混合气形成的曲轴转角能够覆盖提前点火窗口，即形成混合气所需的曲轴转角不早于提前点火窗口；如图2所示，从第三次喷油开始至压缩上死点的一段时间L1均为第三次喷油的蒸发混合时间，其完全覆盖提前点火窗口。When the ECU recognizes pre-ignition in the pre-ignition window of a cylinder, the cylinder is marked as a cylinder with super-detonation, and the third injection of the cylinder is postponed to the compression stroke, and the third injection is controlled. The time of the oil makes the crank angle formed by the metering mixture cover the pre-ignition window, that is, the crank angle required to form the mixture is not earlier than the pre-ignition window; as shown in Fig. 2, from the third injection to the compression The time L1 of the dead point is the evaporation mixing time of the third injection, which completely covers the pre-ignition window.

由于第三次喷油对缸内混合气的冷却作用及可供燃烧的均匀混合气的形成曲轴转角移向压缩上死点，导致混合气被缸内润滑油点燃时相应的提前点火位置后移且点火滞后期延长，使得火花塞在润滑油引发混合气提前点火之前完成点火，即实现正常点火，从而抑制超级爆震。Due to the cooling effect of the third injection on the in-cylinder mixture and the formation of the uniform mixture of the combustible combustion, the crank angle is shifted to the compression top dead center, and the corresponding pre-ignition position is moved backward when the mixture is ignited by the in-cylinder lubricating oil. And the ignition lag period is extended, so that the spark plug completes the ignition before the lubricating oil initiates the pre-ignition of the mixed gas, that is, normal ignition is achieved, thereby suppressing super-knocking.

如果在实施图2所示的推迟第三次喷油的策略后不能有效抑制超级爆震，可以对混合气进行加浓，使得所形成的混合气对应的过量空气系数为最大火焰速度下的过量空气系数，进而提高点燃混合气所需的点火能量，增加提前点火的难度。If the super-knocking cannot be effectively suppressed after implementing the strategy of delaying the third injection shown in FIG. 2, the mixture may be enriched so that the excess air ratio corresponding to the formed mixture is an excess at the maximum flame speed. The air coefficient, in turn, increases the ignition energy required to ignite the mixture and increases the difficulty of pre-ignition.

如图4所示，计量混合气的点火能量最小，即当过量空气系数等于1时，混合气最容易被点燃，当混合气浓度增加时，要求的点火能量增加，同时，所形成的火焰速度提高。在图4中，以λ表示过量空气系数，以实线表示的曲线为火焰速度的变化，以虚线表示的曲线为点火能量的变化。可见，在λ＝0.78左右时达到火焰速度的最大值，此时，如果继续加浓，火焰速度将下降，在λ＝0.61左右时到达混合气着火浓度的下界限，在该 浓度时不能形成稳定的火焰。混合气要求的点火能量越大，润滑油自燃释放的能量点燃混合气就越困难，故发生提前点火的可能性就越小；同时，即使发生提前点火，促使火焰以最大速度传播，使混合气尽可能被火焰点燃而不是自燃，因而不能引发超级爆震。上述原理可以应用于本发明中对混合气进行加浓的控制策略中。As shown in Fig. 4, the ignition energy of the metered mixture is the smallest, that is, when the excess air ratio is equal to 1, the mixture is most easily ignited, and when the concentration of the mixture is increased, the required ignition energy is increased, and at the same time, the flame speed is formed. improve. In Fig. 4, the excess air coefficient is represented by λ, the curve indicated by the solid line is the change of the flame speed, and the curve indicated by the broken line is the change of the ignition energy. It can be seen that the maximum value of the flame speed is reached when λ=0.78. At this time, if the enrichment is continued, the flame speed will decrease, and when the λ=0.61 or so, the lower limit of the mixture ignition concentration is reached. A stable flame cannot be formed at the concentration. The greater the ignition energy required by the mixture, the more difficult it is to ignite the mixture by the energy released by the self-ignition of the lubricant, so the possibility of pre-ignition is less; at the same time, even if pre-ignition occurs, the flame is caused to propagate at maximum speed, so that the mixture is mixed. When possible, it is ignited by the flame instead of spontaneous combustion, so it cannot cause super-knocking. The above principle can be applied to the control strategy for enriching the mixed gas in the present invention.

详细地，如图3所示，如果图2所示的控制策略不能有效抑制提前点火引发的超级爆震，可以对混合气实施加浓，使得形成混合气的过量空气系数对应于最大火焰速度，即可以处于图4中所示的λ＝0.78位置。In detail, as shown in FIG. 3, if the control strategy shown in FIG. 2 cannot effectively suppress the super-knock caused by the pre-ignition, the mixture may be enriched so that the excess air coefficient forming the mixture corresponds to the maximum flame speed. That is, it can be at the λ=0.78 position shown in FIG.

增加的喷油量可以平均分配给三次喷油，由于发动机混合气的浓度由ECU根据设置在三元催化器前的氧传感器信号控制，故加浓需要对各气缸同时实施，即当ECU识别某一气缸为超级爆震气缸且图2所示的控制策略不足以消除超级爆震时，各气缸的第三次喷油均被推迟至压缩冲程，同时实施加浓策略，并控制各气缸的喷油时间，使得形成混合气的曲轴转角覆盖提前点火窗口。The increased fuel injection amount can be equally distributed to three injections. Since the concentration of the engine mixture is controlled by the ECU according to the oxygen sensor signal disposed in front of the three-way catalyst, enrichment needs to be performed simultaneously for each cylinder, that is, when the ECU recognizes a certain When a cylinder is a super-detonation cylinder and the control strategy shown in Figure 2 is insufficient to eliminate super-knocking, the third injection of each cylinder is postponed to the compression stroke, and a enrichment strategy is implemented, and the injection of each cylinder is controlled. The oil time causes the crank angle forming the mixture to cover the pre-ignition window.

如图3所示，各次喷油占总喷油量的比例分别可以设置为35％、40％、25％，缸内混合气的过量空气系数λ随三次喷油的变化分别为2.23、1.04、0.78。在第二次喷油完成后，λ＝1.04时所对应的混合气的温度远低于混合气的燃点，不足以被任何点火源点燃，也就不会被润滑油点燃。同时，由于喷油量提高，与图2所示的喷油策略相比，可以适当提前第三次喷油的时间，以保证第三次喷油有足够的蒸发和混合时间，形成均匀的可燃的浓混合气。如图3所示，从第三次喷油开始至压缩上死点的时间L2均可以构成第三次喷油的蒸发混合时间，其时间较长，完全覆盖了提前点火窗口。As shown in Figure 3, the ratio of each injection to the total fuel injection can be set to 35%, 40%, 25%, respectively. The excess air ratio λ of the in-cylinder mixture changes with the three injections to 2.23, 1.04. , 0.78. After the second injection is completed, the temperature of the mixture corresponding to λ=1.04 is much lower than the ignition point of the mixture, which is not enough to be ignited by any ignition source, and will not be ignited by the lubricating oil. At the same time, due to the increase in fuel injection amount, compared with the fuel injection strategy shown in Figure 2, the third injection time can be appropriately advanced to ensure sufficient evaporation and mixing time for the third injection to form a uniform flammability. a rich mixture. As shown in FIG. 3, the time L2 from the start of the third injection to the compression top dead center may constitute the evaporation mixing time of the third injection, which is longer and completely covers the pre-ignition window.

采用上述加浓控制策略与推迟第三次喷油时间的控制策略相互结合，一方面，第三次喷油发生在压缩冲程，第三次喷油的燃料蒸发所需的汽化潜热会从混合气中吸收大量的热能，以降低被压缩的混合气的温度，起到对混合气的冷却作用，提高了混合气被润滑油点燃的难度；另一方面，第三次喷油在冷却混合气的同时也冷却了附着在燃烧室壁面上的润滑油颗粒，使得其温度降低，消弱其达到自燃的条件，当润滑油颗粒表面的温度低于着火点时便不再能成为点火源；再者，喷油量的增加减少了缸内的氧 气浓度，导致混合气的点火滞后期因缺氧而延长，即使提前点火发生，提前点火影响的区域也很小，则混合气的燃烧依然主要由火花塞点火所控制，超级爆震从而得以抑制。The above-mentioned enrichment control strategy is combined with the control strategy for delaying the third injection time. On the one hand, the third injection occurs in the compression stroke, and the latent heat of vaporization required for the third injection of fuel is vaporized from the mixture. Absorbing a large amount of heat energy to reduce the temperature of the compressed mixture, cooling the mixture, and improving the difficulty of the mixture being ignited by the lubricating oil; on the other hand, the third injection is cooling the mixture. At the same time, the lubricating oil particles attached to the wall surface of the combustion chamber are cooled, so that the temperature thereof is lowered, and the self-ignition condition is weakened. When the temperature of the surface of the lubricating oil particles is lower than the ignition point, the ignition source can no longer be used as an ignition source; The increase in fuel injection reduces the oxygen in the cylinder The gas concentration causes the ignition lag period of the mixture to be prolonged due to lack of oxygen. Even if the pre-ignition occurs, the area affected by the pre-ignition is small, and the combustion of the mixture is still mainly controlled by the spark plug ignition, and the super-knocking is suppressed.

即使加浓控制策略并不能完全消除提前点火，也可以最大程度地削弱爆震强度，减小提前点火引发的不正常燃烧对发动机的破坏。Even if the enrichment control strategy does not completely eliminate the pre-ignition, it can minimize the knock intensity and reduce the damage of the engine caused by the abnormal combustion caused by the pre-ignition.

更进一步，在上述控制策略均不能抑制超级爆震时，为保护发动机，ECU可以按照对被驱动车辆影响最小的方式对发动机实施限扭，以跳出爆震区运行。对配有自动挡变速箱的车辆，ECU可以控制发动机沿等功率线降扭；对于配有手动挡变速箱的车辆，ECU可控制发动机以对驾驶性能影响尽可能小的方式离开超级爆震区运行。鉴于超级爆震发生的随机性以及不持续性，对超级爆震的控制措施通常为有限时间控制。Furthermore, in the case that the above control strategy cannot suppress super-knocking, in order to protect the engine, the ECU can limit the engine in a manner that minimizes the influence on the driven vehicle to jump out of the knocking zone. For vehicles with automatic gearboxes, the ECU can control the engine to be twisted along the same power line; for vehicles with manual gearboxes, the ECU can control the engine to leave the Super Detonation Zone in such a way as to minimize the impact on drivability. run. In view of the randomness and non-sustainability of super-knocking, the control measures for super-knocking are usually limited time control.

需要说明的是，原则上，可以不增加新的设备而通过在ECU中增加新的控制策略实施上述控制方法，但实施前必须对发动机进行必要的标定，且发动机的ECU及供油***必须具有分缸控制和多次喷油的条件，具体参见上文的描述。但是，上述条件并不是任一台发动机的控制***及喷油***均能够满足的，目前，欧5/欧6的发动机才具有上述控制策略的实施条件。因此，对于此类发动机，并不需增加新的装置。但是，对不具有上述控制策略实施条件的发动机，ECU及供油***必须扩展才可能具有可实施所提出控制策略的条件，否则，多次喷油及分缸喷油控制均无法实现。It should be noted that, in principle, the above control method can be implemented by adding a new control strategy to the ECU without adding new equipment, but the engine must be calibrated before implementation, and the engine ECU and the fuel supply system must have The conditions for split cylinder control and multiple injections are described in detail above. However, the above conditions are not satisfied by any engine control system and fuel injection system. At present, the Euro 5/Euro 6 engine has the implementation conditions of the above control strategy. Therefore, there is no need to add new devices for such engines. However, for an engine that does not have the above-mentioned control strategy, the ECU and the fuel supply system must be expanded to have the conditions for implementing the proposed control strategy. Otherwise, multiple injection and split injection control cannot be achieved.

本发明仅以其中一种发动机为例进行说明，请进一步结合图5。如图5所示，在直喷增压汽油机中，空气经由增压器压缩机1、中冷器2、电子节气门3后进入发动机6的进气歧管4，并分配至各个气缸8。根据发动机6喷油策略，燃油通过高压共轨供油***5及多孔喷油器7按点火次序依次向各缸喷油。燃烧废气经排气歧管9排出气缸8，流向下游的增压器废气涡轮机10，并通过增压器废气涡轮机10及排气氧传感器11，再经过三元催化器12净化后排到外部环境中。其中，增压器废气涡轮机10的输出功用于驱动增压器压缩机1，三元催化器12前的发动机排气氧传感器11根据排气的氧浓度调整喷油器的喷油量，以使得三元催化器12更有效地处理发动机6排放的污染物。 The present invention is described by taking only one of the engines as an example, and furthermore to FIG. As shown in FIG. 5, in the direct injection supercharged gasoline engine, air enters the intake manifold 4 of the engine 6 via the supercharger compressor 1, the intercooler 2, and the electronic throttle 3, and is distributed to the respective cylinders 8. According to the fuel injection strategy of the engine 6, the fuel is injected into the cylinders in turn by the high pressure common rail oil supply system 5 and the porous injector 7 in the order of ignition. The combustion exhaust gas exits the cylinder 8 through the exhaust manifold 9, flows to the downstream supercharger exhaust gas turbine 10, passes through the supercharger exhaust gas turbine 10 and the exhaust oxygen sensor 11, and is purified by the three-way catalytic converter 12 and discharged to the external environment. in. Wherein, the output work of the supercharger exhaust gas turbine 10 is used to drive the supercharger compressor 1, and the engine exhaust oxygen sensor 11 in front of the three-way catalyst 12 adjusts the fuel injection amount of the injector according to the oxygen concentration of the exhaust gas, so that The three-way catalyst 12 processes the pollutants discharged from the engine 6 more efficiently.

其中，详细地控制方法可以参照上文的说明执行，此处不再赘述。The detailed control method can be implemented by referring to the above description, and details are not described herein again.

以上对本发明所提供的直喷增压汽油机超级爆震的控制方法进行了详细介绍。本文中应用了具体个例对本发明的原理及实施方式进行了阐述，以上实施例的说明只是用于帮助理解本发明的核心思想。应当指出，对于本技术领域的普通技术人员来说，在不脱离本发明原理的前提下，还可以对本发明进行若干改进和修饰，这些改进和修饰也落入本发明权利要求的保护范围内。 The control method of the super-squeaking of the direct-injection supercharged gasoline engine provided by the present invention is described in detail above. The principles and embodiments of the present invention have been described herein with reference to specific examples. The description of the above embodiments is only for the purpose of understanding the core concepts of the present invention. It should be noted that those skilled in the art can make various modifications and changes to the present invention without departing from the spirit and scope of the invention.

Claims (8)

1. 一种直喷增压汽油机超级爆震的控制方法，其特征在于，包括以下步骤：A control method for super-squeezing of a direct-injection supercharged gasoline engine, characterized in that the method comprises the following steps:

   1)识别因进入缸内的润滑油自燃引发提前点火而产生超级爆震的气缸，并将其标识为超级爆震气缸；1) Identify the cylinder that caused super-detonation due to pre-ignition caused by spontaneous combustion of the lubricating oil entering the cylinder, and identify it as a super-detonation cylinder;

   2)将所述超级爆震气缸的最后一次喷油推迟到压缩冲程，并通过控制最后一次喷油的时间，使得形成可供燃烧的混合气时的曲轴转角不早于提前点火所对应的曲轴转角。2) deferring the last injection of the super detonation cylinder to the compression stroke, and by controlling the time of the last injection, so that the crank angle when forming the combustible mixture is not earlier than the crankshaft corresponding to the pre-ignition Corner.
2. 如权利要求1所述的控制方法，其特征在于，所述步骤1)具体包括：判断是否存在因进入缸内的润滑油自燃引发提前点火而产生超级爆震的气缸，如果是，则将其标识为超级爆震气缸，并执行所述步骤2)，如果否，则终止。The control method according to claim 1, wherein the step 1) specifically comprises: determining whether there is a cylinder that generates super-detonation due to pre-ignition caused by spontaneous combustion of the lubricating oil entering the cylinder, and if so, It is identified as a super-detonation cylinder and the step 2) is performed, and if not, it is terminated.
3. 如权利要求1-2任一项所述的控制方法，其特征在于，在所述步骤2)之后还包括以下步骤：The control method according to any one of claims 1-2, further comprising the following steps after the step 2):

   3)判断超级爆震是否被抑制，如果是，则终止，如果否，则执行步骤4)；3) Determine whether the super knock is suppressed, if yes, terminate, if not, proceed to step 4);

   4)增加各气缸每次喷油的喷油量，使得最后一次喷油所形成混合气的浓度对应于最大火焰速度，并按照所述步骤2)控制各气缸最后一次喷油的时间。4) Increasing the injection amount of each injection of each cylinder, so that the concentration of the mixture formed by the last injection corresponds to the maximum flame speed, and controlling the time of the last injection of each cylinder according to the step 2).
4. 如权利要求3所述的控制方法，其特征在于，在所述步骤4)之后还包括以下步骤：The control method according to claim 3, further comprising the following steps after said step 4):

   5)判断超级爆震是否被抑制，如果是，则终止，如果否，则执行步骤6)；5) Determine whether the super knock is suppressed, if yes, terminate, if not, proceed to step 6);

   6)对发动机实施限扭，以跳出超级爆震区运行。6) Limit the torque of the engine to jump out of the super detonation zone.
5. 如权利要求4所述的控制方法，其特征在于，在所述步骤6)中，对发动机降扭升速，以便其在超级爆震区外以相同的输出功率运行。The control method according to claim 4, wherein in said step 6), the engine is ramped up so that it operates at the same output power outside the super knock zone.
6. 如权利要求5所述的控制方法，其特征在于，在所述步骤6)中，发动机降扭升速运行至少500个工作循环或30秒，然后终止。The control method according to claim 5, wherein in said step 6), the engine is operated at a reduced speed of at least 500 cycles or 30 seconds, and then terminated.
7. 如权利要求4所述的控制方法，其特征在于，在所述步骤3)或所 述步骤5)中，如果超级爆震被抑制，则按照所述步骤2)或所述步骤4)继续执行至少500个工作循环或至少30秒，然后再终止。The control method according to claim 4, wherein in said step 3) or In step 5), if the super knock is suppressed, then at least 500 work cycles or at least 30 seconds are continued according to the step 2) or the step 4), and then terminated.
8. 如权利要求3所述的控制方法，其特征在于，在所述步骤2)和所述步骤4)中，每循环喷油分至少三次进行，最后一次喷油的喷油量为25％～33％。 The control method according to claim 3, wherein in the step 2) and the step 4), the fuel injection per cycle is performed at least three times, and the fuel injection amount of the last injection is 25% to 33. %.

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