Double direct injection system control method and device, engine and automobile

Abstract

The invention provides a double-direct-injection-system control method and device, an engine and an automobile, and relates to the field of engines. According to the scheme, when the engine is started, the fuel quantity required value of the engine is obtained, whether the fuel quantity required value is smaller than a target value or not is judged, and when it is judged that the fuel quantity required value is not smaller than the target value, the engine is started. If only one injection nozzle is used to inject fuel of a fuel amount demand value for a long time, the probability value of abnormal combustion phenomena such as misfire and knock caused by the overlong injection time of the injection nozzle exceeds a target probability, and at this time, the injection time of the fuel is reduced. According to the technical scheme, the first injection nozzle and the second injection nozzle can be adopted to inject the target fuel at the same time, due to the fact that the first injection nozzle and the second injection nozzle are adopted to inject the target fuel at the same time, the injection duration is shortened by half compared with the injection duration spent by adopting one injection nozzle to inject the fuel, and the probability value of abnormal combustion phenomena such as engine fire knocking is reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the engine technical field, specifically relates to a double direct injection system control method, device, engine and automobile. BACKGROUND

[0002] Methanol, with its outstanding anti-knock characteristics, rapid flame propagation rate, and clean renewable advantages, stands out among numerous fuels and is widely regarded as one of the most promising options in the field of internal combustion engine alternative fuels.

[0003] At present, most of the port injection type methanol engines adopt a single nozzle per cylinder injection strategy, which specifically involves placing a methanol injector at the intake manifold position. However, during the actual operation and running process of the bench test, this scheme gradually exposes some problems that need to be solved: due to the excessive duration of methanol injection, the engine cycle variation becomes more severe, ultimately leading to misfire, knock, and a series of abnormal combustion phenomena, which adversely affect the performance and stability of the engine. SUMMARY

[0004] Therefore, the embodiments of the present application provide a double direct injection system control method, device, engine and automobile to reduce the problem of misfire, knock and other abnormal combustion phenomena caused by the excessive duration of injection nozzle.

[0005] To achieve the above-mentioned purpose, the embodiments of the present application provide the following technical solutions:

[0006] A double direct injection system control method, comprising:

[0007] determining whether the fuel quantity demand value of the engine is less than a target value;

[0008] controlling the first injection nozzle to inject target fuel when the fuel quantity demand value is less than the target value;

[0009] controlling the first injection nozzle and the second injection nozzle to simultaneously inject target fuel when the fuel quantity demand value is not less than the target value.

[0010] Optionally, in the double direct injection system control method, the double direct injection system is an in-cylinder direct injection system, and the first injection nozzle and the second injection nozzle are fixed on the cylinder head.

[0011] Optionally, in the double direct injection system control method, determining whether the fuel quantity demand value of the engine is less than a target value comprises:

[0012] determining whether the load of the engine is lower than a target load;

[0013] When the load of the engine is lower than the target load, it is determined that the fuel amount demand value of the engine is less than a target value, otherwise, it is determined that the fuel amount demand value of the engine is not less than the target value.

[0014] Optionally, in the double direct injection system control method, the method further comprises:

[0015] The cumulative injection duration of the first injection nozzle and the cumulative injection duration of the second injection nozzle are obtained.

[0016] When the difference between the cumulative injection duration of the first injection nozzle and the cumulative injection duration of the second injection nozzle is greater than a calibration duration, the identities of the first injection nozzle and the second injection nozzle are controlled to be interchanged.

[0017] Optionally, in the double direct injection system control method, the control of the first injection nozzle to inject target fuel comprises:

[0018] The injector injection duration matched with the fuel amount demand value is obtained from the first preset mapping relationship, and the first injection nozzle is controlled to inject target fuel based on the injector injection duration;

[0019] The control of the first injection nozzle and the second injection nozzle to simultaneously inject target fuel comprises:

[0020] The injector injection duration matched with the fuel amount demand value is obtained from the second preset mapping relationship, and the first injection nozzle and the second injection nozzle are controlled to inject target fuel based on the injector injection duration.

[0021] Optionally, in the double direct injection system control method, before the determination of whether the fuel amount demand value of the engine is less than a target value, the method further comprises:

[0022] The fuel type of the engine is obtained.

[0023] When the fuel type is a target fuel, the subsequent steps of determining whether the fuel amount demand value of the engine is less than a target value and the subsequent steps are continued to be executed.

[0024] Optionally, in the double direct injection system control method, the target fuel is a fuel with a target heat value, and the target heat value is lower than the heat value of gasoline.

[0025] A double direct injection system control device comprises:

[0026] A fuel amount demand value determination unit is configured to determine whether a fuel amount demand value of an engine is less than a target value.

[0027] A jet nozzle control unit controls the first jet nozzle to jet target fuel when the fuel amount demand value is less than a target value, and controls the first jet nozzle and the second jet nozzle to jet target fuel at the same time when the fuel amount demand value is not less than the target value.

[0028] An engine including the dual direct injection system control device described above.

[0029] An automobile including the engine described above.

[0030] Based on the technical solution described above, the scheme provided in the embodiment of the application acquires the fuel amount demand value of the engine when the engine starts, judges whether the fuel amount demand value is less than a target value, and if the fuel amount demand value is not less than the target value, the time taken to jet the fuel amount demand value of fuel by using only one jet nozzle is long, at this time, the probability value of abnormal combustion phenomena such as misfire knock caused by the long jetting time of the jet nozzle exceeds a target probability, at this time, in order to reduce the jetting time of fuel, the first jet nozzle and the second jet nozzle can be used to jet target fuel at the same time, since the first jet nozzle and the second jet nozzle jet target fuel at the same time, the jetting time is shortened by half compared with the jetting time taken by using one jet nozzle to jet fuel, and the probability value of abnormal combustion phenomena such as misfire knock of the engine is reduced. BRIEF DESCRIPTION OF DRAWINGS

[0031] In order to more clearly illustrate the technical solutions in the embodiments of the application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description only are the embodiments of the application, and for those skilled in the art, other drawings can be obtained based on the provided drawings without creative labor.

[0032] Figure 1 A flowchart of a dual direct injection system control method provided for the embodiment of the application;

[0033] Figure 2 A flowchart of judging whether the fuel amount demand value of the engine is less than a target value provided for the embodiment of the application;

[0034] Figure 3 A structural diagram of a dual direct injection system control device provided for the embodiment of the application;

[0035] Figure 4 A structural diagram of an electronic device provided for the embodiment of the application. DETAILED DESCRIPTION

[0036] The embodiments of the present application will be described below in conjunction with the accompanying drawings. The terms used in the embodiments section of the present application are only used to explain the specific embodiments of the present application, and are not intended to limit the present application.

[0037] The embodiments of the present application will be described below in conjunction with the accompanying drawings. The embodiments of the present application will be described below in conjunction with the accompanying drawings. The skilled person in the art can know that, with the development of technology and the emergence of new scenarios, the technical solutions provided by the embodiments of the present application are also applicable to similar technical problems.

[0038] The terms "first", "second", and the like in the specification and claims of the present application and the above-described drawings are used to distinguish similar objects, and do not necessarily indicate a specific order or sequence. It should be understood that the terms used in this way can be interchanged under appropriate circumstances, and this is only a way of distinguishing the objects with the same attributes in the description of the embodiments of the present application. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion, so that the processes, methods, systems, products or equipment containing a series of units do not have to be limited to those units, but can include other units not clearly listed or inherent to these processes, methods, products or equipment.

[0039] To prevent abnormal combustion phenomena such as misfire knock as much as possible due to the long injection time of the injection nozzle, the present application installs a double injector, performs fuel injection through the double injector, uses two injection nozzles during double injector injection, and can be divided into a main injection nozzle (first injection nozzle) and a secondary injection nozzle (second injection nozzle). The opening and closing timing and injection amount of the double injection nozzle are independently adjusted by an electronic control unit (ECU) or a mechanical system to adapt to different working condition requirements. The cooperative work of the double injection nozzle can improve the mixing of fuel and air, reduce unburned fuel, and reduce emissions. It has the characteristics of optimizing the combustion process, reducing pollutant emissions, and adapting to multiple working conditions. The double injection scheme has the characteristic of short injection time compared with the single injection scheme. Based on this, the present application proposes a double direct injection system control method.

[0040] Referring to Figure 1 The double direct injection system control method disclosed in the present application can include:

[0041] Step S101: obtaining a fuel quantity demand value of the engine;

[0042] Step S102: determining whether the fuel quantity demand value is less than a target value.

[0043] The fuel quantity demand value refers to the amount of fuel required by the engine to be injected by the injection nozzle in each ignition cycle. In obtaining the fuel quantity demand value, engine parameters can be detected, and the fuel quantity demand value of the engine at the current time can be calculated based on the detected parameters. Specifically, the calculation of the fuel quantity demand value is a relatively mature technical solution in the prior art, and the existing solution can be directly used to calculate the fuel quantity demand value, which will not be described in detail in this application.

[0044] When the injection nozzle injects fuel, the injection time of the injection nozzle is related to the size of the fuel quantity demand value. The larger the fuel quantity demand value, the longer the injection time of the injection nozzle. Therefore, the injection time of the injection nozzle is positively correlated with the fuel quantity demand value. The fuel quantity demand value can be equivalent to the injection time. A target value of the fuel quantity can be pre-configured in this application. The injection time corresponding to the target value is the time when the probability value of abnormal combustion phenomena such as misfire and knock caused by the too long injection time of the injection nozzle exceeds the target probability. After the fuel quantity demand value is determined, the fuel quantity demand value is compared with the target value to determine whether the fuel quantity demand value is less than the target value.

[0045] Step S103: When the fuel quantity demand value is less than the target value, control the first injection nozzle to inject the target fuel.

[0046] In this embodiment, when it is determined that the fuel quantity demand value is less than the target value, the injection time of the injection nozzle is relatively short at this time, and the probability of abnormal combustion phenomena such as misfire and knock is relatively low. At this time, the first injection nozzle can be directly used to inject the target fuel, that is, only one injection nozzle is used to inject the target fuel to meet the fuel demand of the engine.

[0047] Step S104: When the fuel quantity demand value is not less than the target value, control the first injection nozzle and the second injection nozzle to simultaneously inject the target fuel.

[0048] In this step, when it is determined that the fuel quantity demand value is not less than the target value, if only one injection nozzle is used to inject the fuel required by the fuel quantity demand value, the time consumed is relatively long. At this time, the probability value of abnormal combustion phenomena such as misfire and knock caused by the too long injection time of the injection nozzle exceeds the target probability. At this time, in order to reduce the injection time of the fuel, the first injection nozzle and the second injection nozzle can be used to simultaneously inject the target fuel. Since the first injection nozzle and the second injection nozzle simultaneously inject the target fuel, the injection time is shortened by half compared with the injection time consumed by using one injection nozzle to inject the fuel, thereby reducing the probability value of abnormal combustion phenomena such as misfire and knock of the engine.

[0049] In the embodiment, after the fuel quantity demand value of the engine is acquired, the fuel quantity demand value is compared with a preset target value. When the fuel quantity demand value is less than the target value, it indicates that the fuel quantity demand value can be injected by using a single injection nozzle within a specified time, and at this time, the first injection nozzle is controlled to inject the target fuel. When the fuel quantity demand value is not less than the target value, it is difficult for the single injection nozzle to inject the fuel quantity demand value within the specified time, and the first injection nozzle and the second injection nozzle are controlled to inject the target fuel at the same time, so as to reduce the injection time of the single injection nozzle, thereby solving the problem that the engine cycle fluctuation is intensified due to the long injection duration, and further causing abnormal combustion phenomena such as misfire and knocking.

[0050] In the prior art, some injection nozzles are installed on the intake manifold. The injection nozzles installed on the intake manifold are far away from the intake valve disc part, which is not conducive to fuel heat absorption and atomization. For example, the methanol fuel injected from the intake manifold to the air duct in a low temperature environment cannot better absorb the high temperature of the intake valve disc part, which affects the atomization effect of the methanol fuel in the intake duct. Therefore, in order to make the injected fuel absorb the high temperature of the engine intake valve disc part as much as possible and improve the atomization effect of the injected methanol in the intake pipe, the first injection nozzle and the second injection nozzle are arranged in a cylinder direct injection manner in the embodiment, that is, the double direct injection system is a cylinder direct injection system, the first injection nozzle and the second injection nozzle are fixed on the cylinder head, and the specifications of the first injection nozzle and the second injection nozzle can be completely the same. In the embodiment, two injector mounting holes are arranged above the intake port of the cylinder head of the engine. The angle of the mounting hole needs to meet the installation requirement that the fuel injection is as close as possible to the position of the intake valve disc part. Specifically, the spray beam axis of the injection nozzle is perpendicular to the center of the intake valve disc surface, and the temperature of the engine intake valve disc part is used to accelerate the fuel atomization and evaporation in the intake duct.

[0051] In the embodiment, the corresponding fuel quantity demand value of the engine is different in different working conditions. In some working conditions, the fuel quantity demand value is higher than the target value, and in some working conditions, the fuel quantity demand value is lower than the target value. For example, refer to Figure 2 , whether the fuel quantity demand value of the engine is less than the target value is judged, and specifically includes:

[0052] Step S201: judging whether the engine is in a low temperature starting working condition.

[0053] When the engine is in the low-temperature starting working condition, it is determined that the fuel amount demand value of the engine is less than a target value, and the engine fuel demand amount is small. If the ECU controls both injectors to work (controls the first injection nozzle and the second injection nozzle to work) in the low-temperature starting working condition, two beams of sprays injected by the first injection nozzle and the second injection nozzle intersect in the intake pipe to form large fuel droplets, which affects the fuel atomization effect in the intake pipe. Therefore, when the engine is in the low-temperature starting working condition, one injector is controlled to inject, that is, the first injection nozzle is controlled to inject fuel, so as to achieve a good atomization injection effect.

[0054] Step S202: determining whether the engine is normally running

[0055] If the engine is not in the low-temperature starting working condition, it is determined whether the engine is normally running, and if not, the step S201 of judging the working condition of the engine is continued.

[0056] Step S203: when the engine is normally running, it is determined whether the load of the engine is less than a target load.

[0057] The target load is a load at which the fuel amount demand value of the engine is equal to a target value. When the engine is in a low load, that is, the engine load rate is less than the target load A, step S204 is executed: it is determined that the fuel amount demand value of the engine is less than the target value. Since the engine fuel demand amount is small in the low load working condition, the single-injector injection amount can meet the engine power demand. In order to reduce the intersection probability of the fuel beams injected by the injection nozzles in the intake pipe, the ECU controls to use the single-injector scheme, that is, the first injection nozzle is used to inject fuel alone. When the engine is in a medium-high load, the engine load rate is greater than or equal to the target load A, step S205 is executed: it is determined that the fuel amount demand value of the engine is not less than (greater than or equal to) the target value. Since the engine fuel demand amount is large in the low load working condition, if the single-injection nozzle is used to inject fuel, the injection amount of the single-injection nozzle is large, and the injection duration is long, and therefore the double-injection nozzle scheme needs to be used, that is, the first injection nozzle and the second injection nozzle are controlled to simultaneously inject the target fuel.

[0058] In the embodiment, if the cumulative use time difference between the first injection nozzle and the second injection nozzle is too large, it is possible to cause the flow rate of the two injection nozzles to be different. For example, if the second injection nozzle is not used for a long time, the residue in the injection nozzle will volatilize and deteriorate, forming a gum-like substance attached to the injection hole, causing blockage and a decrease in atomization effect. Such deposits will directly affect the accuracy of fuel injection, and thus cause engine starting difficulty, idle vibration and other problems. Therefore, in order to prevent such situations from occurring, in the technical solution disclosed in the application, one of the injection nozzles can be randomly selected as the first injection nozzle and the other injection nozzle as the second injection nozzle each time the engine is started, or every fixed time interval, for example, one month, two months or half a year, the identities of the first injection nozzle and the second injection nozzle are exchanged once, or the cumulative injection time of the first injection nozzle and the second injection nozzle is counted, and when the difference between the cumulative injection time of the first injection nozzle and the cumulative injection time of the second injection nozzle is greater than a specified time interval, the identities of the first injection nozzle and the second injection nozzle are exchanged, that is, the original first injection nozzle is marked as the second injection nozzle, and the original second injection nozzle is marked as the first injection nozzle. Such an identity exchange method can ensure that the first injection nozzle and the second injection nozzle can smoothly inject fuel.

[0059] In the embodiment, the fuel types injected by the first injection nozzle and the second injection nozzle are the same, so the first injection nozzle and the second injection nozzle can be two different injection nozzles on the same injector, and the two injection nozzles use a common liquid inlet pipeline. Of course, the first injection nozzle and the second injection nozzle can also be injection nozzles on different injectors, for example, the first injection nozzle is an injection nozzle on a first injector, and the second injection nozzle is an injection nozzle on a second injector. Of course, even if the two injection nozzles correspond to independent injectors, the two injectors can also use a common liquid inlet pipeline.

[0060] In the embodiment, different mapping relationships are used when a single injection nozzle is used to inject fuel and when two injection nozzles are used to inject fuel, the mapping relationships are used to define the correspondence between the fuel quantity demand value and the injection duration of the injection nozzle, when the first injection nozzle is controlled to inject target fuel, the injector injection duration that matches the fuel quantity demand value can be obtained from the first preset mapping relationship, and the first injection nozzle is controlled to inject target fuel based on the injector injection duration; when the first injection nozzle and the second injection nozzle are controlled to inject target fuel at the same time, the injector injection duration that matches the fuel quantity demand value can be obtained from the second preset mapping relationship, and the first injection nozzle and the second injection nozzle are controlled to inject target fuel based on the injector injection duration, wherein the injection duration of the first injection nozzle and the second injection nozzle is less than the specified time, and the injection duration of the first injection nozzle and the second injection nozzle can be the same or different, preferably, in the embodiment, the injection duration of the first injection nozzle and the second injection nozzle is the same.

[0061] In the technical solution disclosed in the embodiment, the engine can be a dual-fuel engine, the engine can use the first fuel as engine fuel or the second fuel as engine fuel, the first fuel can be fuel with a higher calorific value, and the second fuel is fuel with a lower calorific value, when providing the same energy, the fuel quantity demand value corresponding to the fuel with a higher calorific value is smaller, at this time, the overall injection duration of the injection nozzle is shorter, and a single injection scheme can be used, and it is not necessary to use the dual-injection system control method provided in the embodiment, when the second fuel is used as engine fuel, when providing the same energy, the fuel quantity demand value corresponding to the fuel with a lower calorific value is larger, at this time, the overall injection duration of the injection nozzle is longer, when the fuel quantity demand value is greater than the target value, a dual-injection scheme can be used, and therefore, the dual-injection system control method provided in the embodiment can be used. That is, before the step of judging whether the fuel quantity demand value of the engine is less than the target value, the method further includes: obtaining the fuel type of the engine; when the fuel type is target fuel, the subsequent scheme is continued to be executed, that is, the step of judging whether the fuel quantity demand value of the engine is less than the target value and the subsequent scheme are executed, the target fuel is fuel with a calorific value lower than a target calorific value, and the target calorific value is lower than the calorific value of gasoline. For example, in the embodiment, the target fuel can be methanol, ethanol, fuel gas, or the like.

[0062] In combination with the above-mentioned schemes, the dual direct injection system control method provided in the application has the characteristics of shortened injection duration, good fuel atomization effect in the intake pipe, and the like compared with the intake port single-injection nozzle scheme per cylinder, and the control switching of the single injection nozzle and the dual injection nozzle is realized through a related control system (such as an ECU) in combination with the injection quantity demand difference under different working conditions, and the method has better working condition adaptability.

[0063] The embodiment discloses a double direct injection system control device, and specific working contents of each unit in the device are described in the method embodiment. The double direct injection system control device provided by the embodiment is described below, and the double direct injection system control device described below can be correspondingly referred to the double direct injection system control method described above.

[0064] Referring to Figure 3 , the double direct injection system control device comprises a fuel quantity demand value judgment unit 10 and a nozzle control unit 20.

[0065] The fuel quantity demand value judgment unit 10 corresponds to step S101 in the double direct injection system control method, and is used to judge whether the fuel quantity demand value of the engine is less than a target value.

[0066] The nozzle control unit 20 corresponds to steps S102 and S103 in the double direct injection system control method, and is used to control the first nozzle to spray target fuel when the fuel quantity demand value is less than the target value, and control the first nozzle and the second nozzle to spray target fuel at the same time when the fuel quantity demand value is not less than the target value.

[0067] Corresponding to the method, the device can further comprise an identity switching unit, which is used to obtain the cumulative injection time length of the first nozzle and the cumulative injection time length of the second nozzle, and control the identities of the first nozzle and the second nozzle to be exchanged when the difference between the cumulative injection time length of the first nozzle and the cumulative injection time length of the second nozzle is greater than a calibration time length.

[0068] Corresponding to the method, the device can further comprise an enabling unit, which is used to obtain the fuel type of the engine, and trigger the fuel quantity demand value judgment unit 10 and the nozzle control unit 20 to start when the fuel type is target fuel.

[0069] Corresponding to the device, the application further discloses an electronic device comprising at least one processing device and a storage device connected with the processing device, wherein the storage device is used to store a computer program, and the processing device is used to execute the computer program, so that the electronic device can implement any one of the double direct injection system control methods. The electronic device can be a vehicle-mounted electronic device, for example, an ECU (Electronic Control Unit), a VCU (Vehicle Control Unit), an MCU (Micro Controller Unit), an HCU (Hybrid Control Unit), etc.

[0070] Reference Figure 4 The embodiment of the present application also provides a specific structural diagram of the electronic device. The electronic device in the embodiment of the present application can include but is not limited to a vehicle-mounted terminal such as an ECU (Electronic Control Unit), a VCU (Vehicle Control Unit), an MCU (Micro Controller Unit), an HCU (Hybrid Control Unit), and the like. Figure 4 The electronic device shown is only an example and should not bring any limitation to the functions and use range of the embodiment of the present application.

[0071] As Figure 4 shown, the electronic device can include a processing device (for example, a central processing unit, a graphics processing unit, and the like) 601, which can perform various appropriate actions and processes according to a program stored in a read-only memory (ROM) 602 or a program loaded from a storage device 608 to a random access memory (RAM) 603. In the state that the electronic device is powered on, various programs and data required for the operation of the electronic device are also stored in the RAM 603. The processing device 601, the ROM 602, and the RAM 603 are connected to each other through a bus 604. An input / output (I / O) interface 605 is also connected to the bus 604.

[0072] Generally, the following devices can be connected to the I / O interface 605: an input device 606 including, for example, a touch screen, a touch pad, a keyboard, a mouse, a camera, a microphone, an accelerometer, a gyroscope, and the like; an output device 607 including, for example, a liquid crystal display (LCD), a speaker, a vibrator, and the like; a storage device 608 including, for example, a memory card, a hard disk, and the like; and a communication device 609. The communication device 609 can allow the electronic device to communicate with other devices wirelessly or by wire to exchange data. Although Figure 4 The electronic device with various devices is shown, but it should be understood that it is not required to implement or have all the devices shown. More or fewer devices can be alternatively implemented or provided.

[0073] The embodiment of the present application also provides a computer program product including computer readable instructions, which, when executed on an electronic device, cause the electronic device to implement any one of the double direct injection system control methods provided by the embodiment of the present application.

[0074] The embodiment of the present application also provides a computer readable storage medium, which carries one or more computer programs, which, when executed by an electronic device, can cause the electronic device to implement any one of the double direct injection system control methods provided by the embodiment of the present application.

[0075] The embodiment also provides an engine integrated with the dual direct injection system control device or the electronic device.

[0076] The embodiment also provides an automobile comprising the engine.

[0077] For the convenience of description, the above system is described in various modules in terms of functions. Of course, the functions of the modules can be implemented in one or more software and / or hardware when the present application is implemented.

[0078] Each embodiment in the specification is described in a progressive manner, and the same or similar parts of each embodiment can be referred to each other. Each embodiment mainly describes the difference from other embodiments. Especially, the system or the system embodiment is described more simply because it is basically similar to the method embodiment, and the related part can be referred to the part of the method embodiment. The system and the system embodiment described above are only illustrative, and the units described as separate components can be or can not be physically separated, and the components displayed as units can be or can not be physical units, that is, they can be located in one place or distributed on multiple network units. Part or all of the modules can be selected to achieve the purpose of the embodiment according to the actual needs. Those skilled in the art can understand and implement without creative labor.

[0079] The skilled person can further realize that the units and algorithm steps of each example described in combination with the embodiments disclosed in the specification can be realized by electronic hardware, computer software or combination of the two. In order to clearly show the interchangeability of hardware and software, the composition and steps of each example have been described in general in the above description. Whether the functions are realized by hardware or software depends on the specific application and design constraints of the technical solution. The skilled person can use different methods to realize the described functions for each specific application, but such implementation should not be considered beyond the scope of the present application.

[0080] The steps of the method or algorithm described in combination with the embodiments disclosed in the specification can be directly implemented by hardware, software module executed by a processor, or combination of the two. The software module can be placed in random access memory (RAM), memory, read only memory (ROM), electrically programmable ROM, electrically erasable programmable ROM, register, hard disk, removable disk, CD-ROM, or any other form of storage medium known in the art.

[0081] It is also to be noted that, as used in this specification and the appended claims, the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to "a component" can include a combination of two or more components, and the term "an element" can include comparable reference to a plurality of elements. Additionally, the term "or" as used herein means any one member of a logical disjunction (i.e., it is equivalent to "or" and "or else") and not a logical exclusion. Also, the terms "comprise," "comprising," "include," "including," and the like mean "including but not limited to." Furthermore, the description herein uses terms such as first and second to denote different elements, but the elements should not be limited by such terminology. The terms "first" and "second" are used only to distinguish one element from another and do not imply a physical or chronological order or importance of one element over another.

[0082] The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein can be applied to other embodiments without departing from the spirit or scope of the application. Thus, the present application is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A control method for a dual direct injection system, characterized in that, include: Determine whether the engine's fuel requirement is less than the target value; When the fuel demand value is less than the target value, the first injector is controlled to inject the target fuel; When the fuel demand value is not less than the target value, the first injector and the second injector are controlled to inject the target fuel simultaneously. Obtain the cumulative spray duration of the first nozzle and the cumulative spray duration of the second nozzle; When the difference between the cumulative spray duration of the first nozzle and the cumulative spray duration of the second nozzle is greater than the calibrated duration, the roles of the first nozzle and the second nozzle are switched.

2. The control method for a dual direct injection system according to claim 1, characterized in that, The dual direct injection system is an in-cylinder direct injection system, with the first and second injectors fixed to the cylinder head.

3. The control method for a dual direct injection system according to any one of claims 1-2, characterized in that, Determining whether the engine's fuel requirement is less than the target value includes: Determine if the engine load is lower than the target load; When the engine load is lower than the target load, it is determined that the engine's fuel demand is less than the target value; otherwise, it is determined that the engine's fuel demand is not less than the target value.

4. The control method for a dual direct injection system according to any one of claims 1-2, characterized in that, Controlling the first injector to inject target fuel includes: The injector injection duration that matches the fuel quantity requirement value is obtained from the first preset mapping relationship, and the first injector nozzle is controlled to inject the target fuel based on the injector injection duration; Controlling the first and second injectors to simultaneously inject target fuel includes: The injector injection duration that matches the fuel quantity requirement value is obtained from the second preset mapping relationship, and the first injector and the second injector are controlled to inject the target fuel based on the injector injection duration.

5. The control method for a dual direct injection system according to any one of claims 1-2, characterized in that, Before determining whether the engine's fuel demand is less than the target value, the process also includes: Get the engine's fuel type; When the fuel type is the target fuel, continue with the step of determining whether the engine's fuel demand is less than the target value and subsequent steps.

6. The control method for a dual direct injection system according to claim 5, characterized in that, The target fuel is a fuel with a target calorific value, which is lower than that of gasoline.

7. A control device for a dual direct injection system, characterized in that, include: The fuel demand value judgment unit is used to determine whether the engine's fuel demand value is less than the target value; The injector control unit is used to control the first injector to inject target fuel when the fuel demand value is less than the target value; and to control the first injector and the second injector to inject target fuel simultaneously when the fuel demand value is not less than the target value.

8. An engine, characterized in that, Includes the dual direct injection system control device as described in claim 7.

9. A car, characterized in that, Includes the engine as described in claim 8.

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