Engine cold start control method, system and equipment and storage medium

Abstract

The invention discloses an engine cold start control method, system and device and a storage medium, belongs to the technical field of engine control, and solves the technical problem that a diesel engine is difficult to catch fire in the cold start process. The method is described. The method comprises the steps that whether the cold starting function needs to be started or not is judged through combination of atmospheric pressure and air inlet temperature, and if the cold starting function is successfully activated, the number of preheating dragging turns is determined according to the atmospheric pressure and the air inlet temperature; in the dragging process of the engine, after cylinder judgment succeeds, the engine continues to drag the cycle of preheating the dragging turns; in the cyclic process of dragging and preheating dragging turns, an exhaust butterfly valve is controlled to be closed by a set opening degree, and EGR is controlled to be fully opened; after the cycle of dragging preheating dragging turns is finished, the exhaust butterfly valve is controlled to be fully opened, and EGR is controlled to be fully closed; and the engine is controlled to inject oil to realize one-time starting. The air cylinder can be rapidly heated, and the cold starting effect is effectively improved.

Description

Technical Field

[0001] The present invention relates to the technical field of engine control, and more specifically, to an engine cold start control method, system, device and storage medium. Background Art

[0002] When the engine is started cold, it cannot be started quickly due to reasons such as large frictional internal resistance and low temperature in the cylinder. This is a difficulty in the industry.

[0003] Take diesel engines as an example. During the cold start process, the engine rail pressure needs to be above 300 bar, which places high demands on the performance of the high-pressure common rail. After the cylinder is successfully judged, fuel is injected immediately to start the engine. However, because the temperature in the cylinder is relatively low at this time, it is difficult to ignite, and the cold start effect is not good. Summary of the invention

[0004] The technical problem to be solved by the present invention is to address the above-mentioned deficiencies in the prior art. One purpose of the present invention is to provide an engine cold start control method that can improve the cold start effect.

[0005] A second objective of the present invention is to provide an engine cold start control system.

[0006] A third object of the present invention is to provide a computer device.

[0007] A fourth objective of the present invention is to provide a computer storage medium.

[0008] In order to achieve the above objective 1, the present invention provides an engine cold start control method, comprising the following steps:

[0009] Step 1. Determine whether to enable the cold start function by combining the atmospheric pressure and the intake air temperature. If the cold start function is successfully activated, execute step 2.

[0010] Step 2. Determine the number of preheating rotations according to the atmospheric pressure and the intake air temperature;

[0011] Step 3. During the engine towing process, after the cylinder is judged to be successful, the engine continues to tow the cycle of the preheating towing number of circles; during the towing cycle of the preheating towing number of circles, the exhaust butterfly valve is controlled to close the set opening, and the EGR is controlled to be fully opened;

[0012] Step 4. After the preheating cycle is completed, the exhaust butterfly valve is controlled to be fully opened, and the EGR is controlled to be fully closed;

[0013] Step 5. Control the engine to perform fuel injection to achieve a one-time start.

[0014] As a further improvement, the number of preheating rotations is 5-10.

[0015] Furthermore, during the cycle of towing the preheating towing revolutions, the lubrication system and cooling system of the engine operate normally.

[0016] Furthermore, the set opening is not less than 80% opening.

[0017] Furthermore, the engine drag speed is 400-450rpm.

[0018] Further, a drag revolution number MAP table is pre-calibrated according to the atmospheric pressure and the intake air temperature;

[0019] After the cold start function is successfully activated, the drag rotation MAP table is queried according to the current atmospheric pressure and intake air temperature to obtain the target number of rotations, and the target number of rotations is used as the preheating drag rotation number of rotations.

[0020] Furthermore, the process of calibrating the drag circle MAP table includes:

[0021] Step 11. Construct a laboratory that can simultaneously regulate internal air pressure and temperature;

[0022] Step 12. Installing a test bench in the laboratory;

[0023] Step 13. Install the engine on the test bench;

[0024] Step 14. Prepare a test parameter table for different test pressures and test temperatures;

[0025] Step 15. Control the air pressure and temperature in the laboratory according to the test parameter table;

[0026] Step 16. The starter starts the engine to rotate, and the number of rotations, the rotation time, the power consumption and the cylinder temperature are recorded in real time, and a curve is made on a graph. The best number of rotations is determined based on a comprehensive judgment of each curve as the target number of rotations corresponding to the current test parameters.

[0027] In order to achieve the above-mentioned second objective, the present invention provides an engine cold start control system, comprising:

[0028] A judgment module, used to judge whether to enable the cold start function by combining atmospheric pressure and intake air temperature;

[0029] a towing revolution number determination module, configured to determine the preheating towing revolution number according to the atmospheric pressure and the intake air temperature after the cold start function is successfully activated;

[0030] The dragging module is used to control the dragging of the engine. During the dragging process of the engine, after the cylinder is judged to be successful, the engine is controlled to continue to drag the cycle of the preheating dragging number of circles; during the dragging cycle of the preheating dragging number of circles, the exhaust butterfly valve is controlled to close the set opening, and the EGR is controlled to be fully opened;

[0031] After the preheating cycle is completed, the exhaust butterfly valve is controlled to be fully opened, and the EGR is controlled to be fully closed;

[0032] The starting module is used to control the engine to perform fuel injection to achieve a one-time start.

[0033] In order to achieve the third objective above, the present invention provides a computer device, including a memory and a processor, wherein the memory stores a computer program, and the processor implements the above-mentioned engine cold start control method when executing the computer program.

[0034] In order to achieve the fourth objective above, the present invention provides a computer-readable storage medium having a computer program stored thereon, and when the computer program is executed by a processor, the above-mentioned engine cold start control method is implemented.

[0035] Beneficial Effects

[0036] Compared with the prior art, the present invention has the following advantages:

[0037] In the process of dragging the engine, the cylinder of the present invention contains compressed air, which can instantly make the temperature reach hundreds of degrees or more, and can quickly heat the cylinder. The duration of the process of dragging the engine is 1.3-2.6s, and will not cause the battery to be depleted. The present invention can effectively improve the cold start effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 It is a flow chart of the present invention. DETAILED DESCRIPTION

[0039] The present invention will be further described below with reference to the specific embodiments in the accompanying drawings.

[0040] See also Figure 1 , an engine cold start control method, comprising the following steps 1 to 5:

[0041] Step 1. Determine whether to enable the cold start function by combining atmospheric pressure and intake air temperature. Because it is more difficult to start the engine under low pressure, this method comprehensively considers the effects of atmospheric pressure and intake air temperature on cold start, so that the cold start effect of the engine can be improved in various environments. If the cold start function is successfully activated, proceed to step 2; otherwise, the engine is started normally.

[0042] Step 2. Determine the number of preheating turns based on the atmospheric pressure and intake air temperature.

[0043] Step 3. During the engine towing (i.e., towing the engine through the starter), after the cylinder is judged to be successful, the engine continues to tow for the number of preheating towing circles. During the number of preheating towing circles, the exhaust butterfly valve is controlled to close the set opening, and the EGR is controlled to be fully open. During this period, the compressed air in the cylinder is continuously circulated in the cylinder to achieve a rapid increase in the temperature in the cylinder.

[0044] When the engine is running, the cylinder contains compressed air, which can instantly raise the temperature to over several hundred degrees. The heated air is not exhausted, but circulated to heat the mechanical parts in the cylinder, thus achieving rapid preheating of the cylinder environment.

[0045] The purpose of controlling the exhaust butterfly valve to close the set opening is to unload the partial pressure in the cylinder during the compression process to prevent the starter from being unable to tow the engine due to excessive pressure. The set opening is not less than 80% of the opening. The set opening can be calibrated according to the cylinder model (size) so that when the exhaust butterfly valve is closed at the set opening, the starter can normally tow the engine, and the pressure in the cylinder is the maximum, thereby improving the tow preheating efficiency.

[0046] The cylinder judgment is successful, that is, after the engine timing system judges the cylinder successfully, the cylinder judgment process is that when the engine is running, the camshaft rotates one circle, and the crankshaft rotates 2 circles. The exhaust top dead center and compression top dead center are comprehensively judged according to the phase of the camshaft. Because the engine injects according to the phase angle of the crankshaft, the exhaust top dead center and compression top dead center cannot be distinguished by the crankshaft alone, so the camshaft phase is needed for comprehensive judgment.

[0047] Step 4. After the towing preheating cycle is completed, the temperature in the cylinder reaches the optimal temperature for engine starting. At this time, the exhaust butterfly valve is controlled to be fully open and the EGR is controlled to be fully closed.

[0048] Step 5. Control the engine to inject fuel to achieve a one-time start.

[0049] In this embodiment, the number of preheating rotations is 5-10, and the engine rotation speed is 400-450 rpm.

[0050] During the towing preheating and towing circle cycle, the engine's lubrication system and cooling system work normally to ensure the lubrication effect during the towing process.

[0051] In order to improve the drag preheating effect, a drag circle MAP table can be calibrated in advance according to the atmospheric pressure and intake temperature.

[0052] After the cold start function is successfully activated, first query the towing revolutions MAP table to obtain the target revolutions based on the current atmospheric pressure and intake air temperature, and use the target revolutions as the preheating towing revolutions to improve the accuracy of the preheating.

[0053] The process of calibrating the drag turns MAP table includes:

[0054] Step 11. Construct a laboratory that can simultaneously regulate internal air pressure and temperature;

[0055] Step 12. Install the test bench in the laboratory;

[0056] Step 13. Install the engine on the test bench;

[0057] Step 14. Prepare a test parameter table for different test pressures and test temperatures;

[0058] Step 15. Control the air pressure and temperature in the laboratory according to the test parameter table;

[0059] Step 16. The starter drags the engine, and records the number of drag turns, drag time, power consumption and cylinder temperature in real time, and makes a curve on a graph. Based on the comprehensive judgment of each curve (i.e., under the premise that the cylinder temperature is satisfied, the less power consumption and the shorter the drag time, the better), the best number of drag turns is determined as the target number of turns corresponding to the current test parameters.

[0060] After the cold start function is successfully activated, the oil in the engine oil pan is heated, specifically through an electric heating module (such as a heating wire or a heating tube) to quickly increase the oil temperature, which can help reduce the internal friction resistance of the engine, thereby facilitating towing preheating and subsequent engine injection starting. After the engine is successfully started, the heating of the oil in the engine oil pan is stopped to save energy and avoid battery depletion.

[0061] The present invention uses compressed air in the cylinder during the engine towing process, which can instantly make the temperature reach hundreds of degrees or more, and can quickly heat the cylinder. It is estimated that if a calibration time of 5-10 turns is used, the duration is about 1.3-2.6 seconds at a speed of 400rpm, and the battery will not be depleted (general starters can be towed for more than 2 minutes, but generally cannot be started by cold starting. The national standard is that the towing time should not exceed about 120 seconds). The present invention can effectively improve the cold starting effect.

[0062] An engine cold start control system, comprising:

[0063] A judgment module, used to judge whether to enable the cold start function by combining atmospheric pressure and intake air temperature;

[0064] A towing revolution number determination module, used to determine the preheating towing revolution number according to the atmospheric pressure and the intake air temperature after the cold start function is successfully activated;

[0065] The dragging module is used to control the engine dragging. During the engine dragging process, after the cylinder is judged successfully, the engine is controlled to continue to drag the preheating dragging circle cycle; during the dragging preheating dragging circle cycle, the exhaust butterfly valve is controlled to close the set opening, and the EGR is controlled to be fully open;

[0066] After the towing preheating towing number of circles is completed, the exhaust butterfly valve is controlled to be fully opened, and the EGR is controlled to be fully closed;

[0067] The starting module is used to control the engine to inject fuel to achieve a one-time start.

[0068] A computer device includes a memory and a processor. The memory stores a computer program. When the processor executes the computer program, the above-mentioned engine cold start control method is implemented.

[0069] A computer-readable storage medium stores a computer program, which implements the above-mentioned engine cold start control method when executed by a processor.

[0070] The above are only preferred embodiments of the present invention. It should be pointed out that for those skilled in the art, several modifications and improvements can be made without departing from the structure of the present invention, which will not affect the effect of the implementation of the present invention and the practicality of the patent.

Claims

1. An engine cold start control method, characterized in that: The following steps are involved: Step 1. Determine whether to enable the cold start function by combining the atmospheric pressure and the intake air temperature. If the cold start function is successfully activated, execute step 2. Step 2. Determine the number of preheating rotations according to the atmospheric pressure and the intake air temperature; Step 3. During the engine towing process, after the cylinder is judged to be successful, the engine continues to tow the cycle of the preheating towing number of circles; during the towing cycle of the preheating towing number of circles, the exhaust butterfly valve is controlled to close the set opening, and the EGR is controlled to be fully opened; Step 4. After the preheating cycle is completed, the exhaust butterfly valve is controlled to be fully opened, and the EGR is controlled to be fully closed; Step 5. Control the engine to perform fuel injection to achieve a one-time start.

2. The engine cold start control method according to claim 1, characterized in that: The number of preheating rotations is 5-10.

3. The engine cold start control method according to claim 1, characterized in that: During the towing cycle of the preheating towing revolutions, the lubrication system and cooling system of the engine operate normally.

4. The engine cold start control method according to claim 1, characterized in that: The set opening is not less than 80% opening.

5. The engine cold start control method according to claim 1, characterized in that: The engine is running at 400-450rpm.

6. The engine cold start control method according to claim 1, characterized in that: A drag circle MAP table is pre-calibrated according to the atmospheric pressure and intake air temperature; After the cold start function is successfully activated, the drag rotation MAP table is queried according to the current atmospheric pressure and intake air temperature to obtain the target number of rotations, and the target number of rotations is used as the preheating drag rotation number of rotations.

7. The engine cold start control method according to claim 6, characterized in that: The process of calibrating the drag turn MAP table includes: Step 11. Construct a laboratory that can simultaneously regulate internal air pressure and temperature; Step 12. Installing a test bench in the laboratory; Step 13. Install the engine on the test bench; Step 14. Prepare a test parameter table for different test pressures and test temperatures; Step 15. Control the air pressure and temperature in the laboratory according to the test parameter table; Step 16. The starter starts the engine to rotate, and the number of rotations, the rotation time, the power consumption and the cylinder temperature are recorded in real time, and a curve is made on a graph. The best number of rotations is determined based on a comprehensive judgment of each curve as the target number of rotations corresponding to the current test parameters.

8. An engine cold start control system, characterized in that: include: A judgment module, used to judge whether to enable the cold start function by combining atmospheric pressure and intake air temperature; a towing revolution number determination module, configured to determine the preheating towing revolution number according to the atmospheric pressure and the intake air temperature after the cold start function is successfully activated; The dragging module is used to control the dragging of the engine. During the dragging process of the engine, after the cylinder is judged to be successful, the engine is controlled to continue to drag the cycle of the preheating dragging number of circles; during the dragging cycle of the preheating dragging number of circles, the exhaust butterfly valve is controlled to close the set opening, and the EGR is controlled to be fully opened; After the preheating cycle is completed, the exhaust butterfly valve is controlled to be fully opened, and the EGR is controlled to be fully closed; The starting module is used to control the engine to perform fuel injection to achieve a one-time start.

9. A computer device comprising a memory and a processor, wherein the memory stores a computer program, wherein: When the processor executes the computer program, an engine cold start control method as described in any one of claims 1 to 7 is implemented.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, an engine cold start control method according to any one of claims 1 to 7 is implemented.

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