Engine starting fuel injection control strategy and fuel injection control system

Abstract

The application provides an engine starting fuel injection control strategy, which comprises the following steps: judging whether an engine starting command signal is True or False; judging whether an engine starting request signal is True or False; obtaining an engine rated rotating speed according to an engine water temperature signal; judging whether a signal that the engine rated rotating speed is less than an engine actual rotating speed is True or False; judging whether a signal that the engine actual rotating speed is greater than an engine minimum starting rotating speed is True or False; and respectively pre-controlling fuel injection of an injector by sending a fuel injection command signal and controlling fuel injection of the injector by sending a torque model activation signal to segmentally and accurately control an engine starting stage, so that fuel mixture is not enriched, energy consumption is low, and pollution is small. The application also relates to a fuel injection control system.

Description

Technical Field

[0001] This invention relates to the field of automotive engine technology, and in particular to an engine start-up fuel injection control strategy and fuel injection control system. Background Technology

[0002] In recent years, with the rapid development of my country's automobile industry, the number of cars has increased rapidly; however, due to the large-scale use of cars, it has also brought huge pollution to the environment and further put enormous pressure on the environment and energy.

[0003] Currently, the problems of fuel consumption and energy loss caused by control strategies in traditional engines have not been well resolved, especially during the engine start-up phase. Therefore, how to further reduce energy loss and fuel consumption during engine start-up to improve emissions is a major challenge.

[0004] Currently, the traditional engine start-up control strategy related to fuel injection is to start injecting fuel before the 12V starter motor drives the engine to the starting speed. At the same time, in order for the engine to start smoothly, the fuel mixture is mostly in a rich state at this time. Since the water temperature is not high, more fuel injections are required than under normal conditions, resulting in poor emissions and higher fuel consumption. Summary of the Invention

[0005] In view of this, it is necessary to provide an effective engine start-up fuel injection control strategy and fuel injection control system to solve the problems of low emissions and high fuel consumption during engine start-up.

[0006] This invention provides an engine start-up fuel injection control strategy, which includes the following steps:

[0007] Determine whether the engine start command signal is True or False;

[0008] Determine whether the engine start request signal is True or False;

[0009] The engine rated speed is obtained based on the engine coolant temperature signal;

[0010] The signal indicating that the engine's rated speed is less than the engine's actual speed is True or False.

[0011] The signal indicating that the actual engine speed is greater than the engine's minimum starting speed is True or False.

[0012] When the signal that the actual engine speed is greater than the minimum engine starting speed and the engine start command signal are both True, or when the signal that the engine rated speed is less than the actual engine speed is True, a fuel injection command signal is issued to pre-control the fuel injector to inject fuel.

[0013] When both the engine start request signal and the signal that the engine actual speed is greater than the engine minimum start speed are True, and the engine start command signal is False, a torque model activation signal is issued to control the injector to inject fuel.

[0014] Furthermore, the fuel injection control strategy further includes:

[0015] Start counting the number of fuel injections at the beginning of fuel injection;

[0016] The corresponding calibrated number of fuel injections is obtained based on the engine coolant temperature signal;

[0017] Determine if the current number of fuel injections is greater than the calibrated number of fuel injections;

[0018] When the current number of fuel injections exceeds the calibrated number of fuel injections, an engine start-stop signal is issued, and the fuel injection control strategy is suspended.

[0019] Furthermore, the corresponding calibrated number of fuel injections is obtained by looking up a table based on the engine coolant temperature signal.

[0020] Furthermore, the rated speed of the engine is obtained by looking up a table based on the engine coolant temperature signal.

[0021] Furthermore, the steps for obtaining the engine's rated speed based on the engine coolant temperature signal include:

[0022] The standard starting speed is obtained by looking up the table based on the engine coolant temperature signal;

[0023] The engine's rated speed is obtained by subtracting the starting correction speed from the standard starting speed.

[0024] The present invention also provides an engine start-up fuel injection control system, comprising:

[0025] The water temperature signal acquisition unit is used to acquire engine water temperature signals;

[0026] The engine speed signal acquisition unit is used to acquire the actual engine speed; and

[0027] The control unit, connected to the water temperature signal acquisition unit and the speed signal acquisition unit, receives engine start request signals and engine start command signals, determines whether the engine start request signals and engine start command signals are True, obtains the engine rated speed based on the engine water temperature signal, and determines the relationship between the actual engine speed and the engine rated speed, as well as the relationship between the actual engine speed and the engine minimum starting speed. When the engine rated speed is less than the actual engine speed, or when the engine start command signal is True and the actual engine speed is greater than the engine minimum starting speed, it issues an injection command signal to pre-control the injector to inject fuel. When the engine start request signal is True, the engine start command signal is False, and the actual engine speed is greater than the engine minimum starting speed, it issues a torque model activation signal to control the injector to inject fuel.

[0028] Furthermore, the control unit stores the minimum starting speed of the engine and the correspondence between the engine coolant temperature and the engine rated speed. The control unit selects the corresponding engine rated speed based on the engine coolant temperature signal.

[0029] Furthermore, the correspondence between engine coolant temperature and engine rated speed includes a table showing the correspondence between engine coolant temperature and standard starting speed, as well as the correspondence between standard starting speed and engine rated speed.

[0030] Furthermore, the engine start-up fuel injection control system also includes a fuel injection counter for counting the number of fuel injections by the fuel injector. The fuel injection counter starts counting the number of fuel injections when the fuel injection begins. The control unit also stores the correspondence between engine coolant temperature and calibrated number of fuel injections.

[0031] Furthermore, when the fuel injection starts, the control unit obtains the corresponding calibrated number of fuel injections based on the engine coolant temperature, and determines the relationship between the current number of fuel injections and the calibrated number of fuel injections. When the current number of fuel injections is greater than the calibrated number of fuel injections, it issues an engine start-end signal and suspends fuel injection control.

[0032] This invention achieves precise fuel injection control by having the control unit perform two stages of pre-injection control and control on the fuel injector only when the actual speed of the engine reaches the minimum starting speed. This eliminates the need for enriching the fuel-air mixture, resulting in better emissions and lower fuel consumption.

[0033] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of the present invention more apparent and understandable, preferred embodiments are described in detail below with reference to the accompanying drawings. Attached Figure Description

[0034] Figure 1 This is a structural block diagram of a specific embodiment of the engine start-up fuel injection control system provided by the present invention;

[0035] Figure 2 This is a block diagram illustrating the principle of pre-control of fuel injector injection in the engine start-up fuel injection control strategy provided by the present invention.

[0036] Figure 3 In order to be in Figure 2 Based on this, the principle block diagram of the control unit controlling the fuel injection of the injector is shown.

[0037] Figure 4 In order to be in Figure 3 Based on this, the control unit controls the number of times the injector injects fuel. Detailed Implementation

[0038] To further illustrate the technical means and effects adopted by the present invention in order to achieve the intended purpose, the present invention will be described in detail below with reference to the accompanying drawings and preferred embodiments.

[0039] like Figure 1 As shown, the present invention provides an engine start-up fuel injection control system, including a water temperature signal acquisition unit for acquiring engine water temperature signals, a speed signal acquisition unit for acquiring the actual engine speed r, and a control unit that is signal-connected to the water temperature signal acquisition unit and the speed signal acquisition unit.

[0040] The control unit stores the engine's minimum starting speed r. min The system establishes a correspondence between engine coolant temperature and engine rated speed r1, enabling the control unit to select the corresponding engine rated speed r1 based on different engine coolant temperature signals. In this embodiment, the correspondence between engine coolant temperature and engine rated speed r1 includes a table showing the correspondence between engine coolant temperature and standard starting speed, and a formula for calculating engine rated speed r1. In this embodiment, the control unit looks up the standard starting speed from the table based on the engine coolant temperature signal, and then subtracts the starting correction speed from the standard starting speed to obtain the engine rated speed r1. Both the standard starting speed and the starting correction speed can be obtained experimentally. It is understood that in other embodiments of the invention, the correspondence between engine coolant temperature and engine rated speed r1 can also be represented by a table showing the correspondence between engine coolant temperature and engine rated speed r1, allowing the engine rated speed r1 to be directly obtained from the table based on the engine coolant temperature.

[0041] Furthermore, the control unit can also receive engine start request signals and engine start command signals, and determine whether the engine start request signal and engine start command signal are True, and determine the engine rated speed r1 and the engine minimum starting speed r. min The relationship between the engine's rated speed (r) and the actual engine speed (r) is such that when the engine's rated speed is less than the actual engine speed, or when the engine start command signal is True and the actual engine speed is greater than the engine's minimum start speed, an injection command signal is sent to the injector to perform pre-injection control. During the pre-injection control, the injector has not yet started injecting fuel. Subsequently, when the engine start request signal is True, the engine start command signal is False, and the actual engine speed is greater than the engine's minimum start speed, the control unit sends a torque model activation signal to control the injector to start injecting fuel. This makes the present invention highly efficient in controlling injector fuel injection, requires minimal modification, provides precise control, and is low in cost.

[0042] In this invention, when the engine issues a start command signal, the engine has not yet officially started. When the engine issues a start request signal, the engine officially starts. Correspondingly, during the fuel injection pre-control phase, the engine start command signal is True and the engine start request signal is False. During the formal start fuel injection phase, the engine start command signal is False and the engine start request signal is True. The engine start request signal is applicable when the engine is in a start-stop condition due to the vehicle waiting at a red light or other temporary stop, while the engine start command signal is applicable in non-start-stop conditions. The control unit provided by this invention can determine the vehicle's operating condition by judging whether it has received the engine start request signal and the start command signal, thereby enabling more precise fuel injection control of the injectors when the engine starts.

[0043] Furthermore, the engine start-up fuel injection control system provided by the present invention also includes a fuel injection counter for counting the number of fuel injections by the fuel injector. The control unit also stores the correspondence between engine coolant temperature and calibrated number of fuel injections. The fuel injection counter starts counting the number of fuel injections when fuel injection begins. When fuel injection begins, the control unit looks up the corresponding calibrated number of fuel injections according to the engine coolant temperature and determines the relationship between the current number of fuel injections and the calibrated number of fuel injections. When the current number of fuel injections is greater than the calibrated number of fuel injections, an engine start-up end signal is issued to suspend fuel injection control.

[0044] like Figure 2 and Figure 3 As shown, the present invention also relates to a fuel injection control strategy, which specifically includes the following steps for controlling fuel injection by the fuel injector:

[0045] Determine whether the engine start command signal is True or False;

[0046] Determine whether the engine start request signal is True or False;

[0047] Collect engine coolant temperature signals;

[0048] The engine rated speed r1 is obtained based on the engine coolant temperature signal;

[0049] The signal indicating that the engine's rated speed r1 is less than the engine's actual speed r is True or False.

[0050] The signal indicating that the actual engine speed is greater than the engine's minimum starting speed is True or False.

[0051] When the signal indicating that the actual engine speed is greater than the minimum engine starting speed and the engine start command signal are both True, or when the signal indicating that the engine rated speed is less than the actual engine speed is True, an injection command signal is issued to pre-control the injection of fuel into the injectors.

[0052] In detail, such as Figure 2 As shown, the specific strategy for pre-controlling the fuel injector in the fuel injection control strategy provided by this invention is as follows:

[0053] Determine whether the engine start command signal is True or False;

[0054] Determine whether the engine start request signal is True or False;

[0055] The signal indicating that the actual engine speed is greater than the engine's minimum starting speed is True or False.

[0056] When both the engine start request signal and the signal that the engine actual speed is greater than the engine minimum start speed are True, and the engine start command signal is False, a torque model activation signal is issued to control the injector to inject fuel.

[0057] As can be seen from the above process, when the fuel injector is started and fuel injection is controlled, the actual engine speed r is greater than the engine's minimum starting speed r. min In other words, the engine start-up fuel injection control strategy provided by this invention is applicable when the actual engine speed r is greater than the engine's minimum start-up speed r. min Fuel injection is only permitted at this time. Because the engine speed and water temperature are also high at this time, the fuel-air mixture does not need to be enriched, resulting in good combustion and achieving the goals of good emissions and reduced fuel consumption.

[0058] When the control unit controls the fuel injection of the injector, the specific control strategy is as follows: Figure 4 As shown, it includes:

[0059] The corresponding calibrated number of fuel injections is obtained based on the engine coolant temperature signal;

[0060] Start counting the number of fuel injections at the beginning of fuel injection;

[0061] Determine if the current number of fuel injections is greater than the calibrated number of fuel injections;

[0062] When the current number of fuel injections exceeds the calibrated number of fuel injections, an engine start-up termination signal is issued. Afterward, the engine and its components return to normal operation, and the fuel injection control strategy that individually controls the fuel injectors is suspended. Conversely, when the fuel injection counter value is less than or equal to the calibrated number of fuel injections, the control unit continues to control the fuel injectors until the engine start-up is complete. For details regarding the operation of the fuel injectors and other related components after the engine start-up is completed according to the engine start-up fuel injection control system provided by this invention, please refer to the prior art, which will not be elaborated upon here.

[0063] In summary, this invention achieves precise fuel injection control by having the control unit perform pre-injection control and start fuel injection only when the actual engine speed reaches the engine's minimum starting speed. This eliminates the need for enriching the fuel-air mixture, resulting in better emissions and lower fuel consumption.

[0064] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. An engine start-up fuel injection control strategy, characterized in that, It includes the following steps: Determine whether the engine start command signal is True or False; Determine whether the engine start request signal is True or False; The engine rated speed is obtained based on the engine coolant temperature signal; The signal indicating that the engine's rated speed is less than the engine's actual speed is True or False. The signal indicating that the actual engine speed is greater than the engine's minimum starting speed is True or False. When the signal that the actual engine speed is greater than the minimum engine starting speed and the engine start command signal are both True, or when the signal that the engine rated speed is less than the actual engine speed is True, a fuel injection command signal is issued to pre-control the fuel injector to inject fuel. When both the engine start request signal and the signal that the engine actual speed is greater than the engine minimum start speed are True, and the engine start command signal is False, a torque model activation signal is issued to control the injector to inject fuel.

2. The engine start-up fuel injection control strategy according to claim 1, characterized in that, Further includes: Start counting the number of fuel injections at the beginning of fuel injection; The corresponding calibrated number of fuel injections is obtained based on the engine coolant temperature signal; Determine if the current number of fuel injections is greater than the calibrated number of fuel injections; When the current number of fuel injections exceeds the calibrated number of fuel injections, an engine start-stop signal is issued, and the fuel injection control strategy is suspended.

3. The engine start-up fuel injection control strategy according to claim 2, characterized in that, The corresponding calibrated number of fuel injections is obtained by looking up a table based on the engine coolant temperature signal.

4. The engine start-up fuel injection control strategy according to claim 1, characterized in that, The rated speed of the engine is obtained by looking up a table based on the engine coolant temperature signal.

5. The engine start-up fuel injection control strategy according to claim 1, characterized in that, The steps for obtaining the engine's rated speed based on the engine coolant temperature signal include: The standard starting speed is obtained by looking up the table based on the engine coolant temperature signal; The engine's rated speed is obtained by subtracting the starting correction speed from the standard starting speed.

6. An engine starting fuel injection control system, characterized in that, include: The water temperature signal acquisition unit is used to acquire engine water temperature signals; The engine speed signal acquisition unit is used to acquire the actual engine speed; as well as The control unit, connected to the water temperature signal acquisition unit and the speed signal acquisition unit, receives engine start request signals and engine start command signals, determines whether the engine start request signals and engine start command signals are True, obtains the engine rated speed based on the engine water temperature signal, and determines the relationship between the actual engine speed and the engine rated speed, as well as the relationship between the actual engine speed and the engine minimum starting speed. When the engine rated speed is less than the actual engine speed, or when the engine start command signal is True and the actual engine speed is greater than the engine minimum starting speed, it issues an injection command signal to pre-control the injector to inject fuel. When the engine start request signal is True, the engine start command signal is False, and the actual engine speed is greater than the engine minimum starting speed, it issues a torque model activation signal to control the injector to inject fuel.

7. The engine start-up fuel injection control system according to claim 6, characterized in that, The control unit stores the engine's minimum starting speed and the correspondence between engine coolant temperature and engine rated speed. The control unit selects the corresponding engine rated speed based on the engine coolant temperature signal.

8. The engine start-up fuel injection control system according to claim 7, characterized in that, The correspondence between engine coolant temperature and engine rated speed includes a table showing the correspondence between engine coolant temperature and standard starting speed, as well as the correspondence between standard starting speed and engine rated speed.

9. The engine start-up fuel injection control system according to claim 6, characterized in that, The engine start-up fuel injection control system also includes a fuel injection counter for counting the number of fuel injections. The fuel injection counter starts counting the number of fuel injections when fuel injection begins. The control unit also stores the correspondence between engine coolant temperature and calibrated number of fuel injections.

10. The engine start-up fuel injection control system according to claim 9, characterized in that, When fuel injection begins, the control unit obtains the corresponding calibrated number of fuel injections based on the engine coolant temperature, and determines the relationship between the current number of fuel injections and the calibrated number of fuel injections. If the current number of fuel injections is greater than the calibrated number of fuel injections, it issues an engine start-end signal and suspends fuel injection control.

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