Diagnostic method for overlarge deviation of fuel injection quantity of fuel injector

Abstract

The invention discloses a diagnosis method for the overlarge deviation of the fuel injection quantity of a fuel injector, relates to the field of fuel injectors, and solves the technical problem that the risk of burn-through post-treatment and engine damage exists in the current mode for treating the fuel injection quantity of the fuel injector. The method comprises the steps that a single-cylinder fuel injection quantity correction value and a torque deviation value are obtained, a single-cylinder fuel injector fuel quantity deviation fault detection strategy is triggered according to the single-cylinder fuel injection quantity correction value so as to judge the fuel quantity deviation of the single-cylinder fuel injector, and an overall fuel injector fuel quantity deviation detection strategy is triggered according to the torque deviation value so as to judge the fuel quantity deviation of the overall fuel injector. And triggering protection measures according to the oil quantity deviation of the single-cylinder oil injector and the oil quantity deviation of the whole oil injector. The problem of fuel injection quantity deviation of the fuel injector is found as early as possible, and the risk of damage to the engine and post-treatment is reduced.

Description

Technical Field

[0001] The present invention relates to the field of fuel injectors, and more specifically, it relates to a diagnostic method for excessive deviation of fuel injection quantity of a fuel injector. Background Art

[0002] When the positive deviation of the fuel injection quantity of the fuel injector is too large, a large amount of fuel will burn in a short time, and there is a risk of burning through the aftertreatment.

[0003] When the negative deviation of the fuel injection quantity of the fuel injector is too large, the fuel injection duration will be corrected during the next injection, resulting in some fuel not being fully burned and accumulating on the surface of the cylinder block. If the negative deviation occurs for a long time, a large amount of fuel will accumulate on the surface of the cylinder block, which will further increase the wear. In addition, when these fuels burn again after reaching the temperature, due to the large amount of fuel, the temperature will rise instantly, and the phenomenon of melting the top will occur. There is a risk of damaging the engine.

[0004] The current method for dealing with the fuel injection quantity of the fuel injector only indirectly judges the deviation of the fuel injection quantity based on the rail pressure, and there is no strategy for directly identifying the positive and negative deviations of the fuel injection quantity of the fuel injector. Therefore, there is a risk of burning through the aftertreatment and damaging the engine. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a diagnostic method for excessive deviation of fuel injection quantity of a fuel injector in view of the deficiencies of the prior art, and solve the technical problem that the current method for dealing with the fuel injection quantity of the fuel injector has the risks of burning through the aftertreatment and damaging the engine.

[0006] The diagnostic method for excessive deviation of fuel injection quantity of a fuel injector according to the present invention is as follows: obtain the single-cylinder fuel injection quantity correction value and the torque deviation value, trigger the single-cylinder fuel injector fuel quantity deviation fault detection strategy according to the single-cylinder fuel injection quantity correction value to judge the single-cylinder fuel injector fuel quantity deviation, trigger the overall fuel injector fuel quantity deviation detection strategy according to the torque deviation value to judge the overall fuel injector fuel quantity deviation, and trigger the protection measure according to the single-cylinder fuel injector fuel quantity deviation and the overall fuel injector fuel quantity deviation.

[0007] For further improvement, the single-cylinder fuel injector fuel quantity deviation fault detection strategy is as follows:

[0008] Set the first calibration limit value. When the single-cylinder fuel injection quantity correction value is greater than zero and greater than the first calibration limit value, it is judged that the positive deviation of the single-cylinder fuel injector fuel quantity is too large, and at the same time, the single-cylinder fuel injector fuel quantity deviation is further judged;

[0009] When the single-cylinder fuel injection quantity correction value is less than zero and less than the first calibration limit value, it is judged that the negative deviation of the single-cylinder fuel injector fuel quantity is too large, and at the same time, the single-cylinder fuel injector fuel quantity deviation is further judged.

[0010] Further, the method for further judging the fuel quantity deviation of the single-cylinder injector is as follows:

[0011] Set a first calibration time limit. When it is judged that the positive fuel quantity deviation of the single-cylinder injector is too large, the first calibration time limit starts to count down simultaneously; when the first calibration time limit ends, if the corrected value of the single-cylinder fuel injection quantity is still greater than zero and greater than the first calibration limit, it is judged that the fuel quantity deviation of the single-cylinder injector is large.

[0012] When it is judged that the negative fuel quantity deviation of the single-cylinder injector is too large, the first calibration time limit starts to count down simultaneously; when the first calibration time limit ends, if the corrected value of the single-cylinder fuel injection quantity is still less than zero and less than the first calibration limit, it is judged that the fuel quantity deviation of the single-cylinder injector is large.

[0013] Furthermore, the overall fuel injector fuel quantity deviation detection strategy is as follows:

[0014] Set a second calibration limit. When the torque deviation value is greater than zero and greater than the second calibration limit, it is judged that the positive fuel quantity deviation of the overall fuel injector is too large, and at the same time, a further judgment is made on the overall fuel injector fuel quantity deviation.

[0015] When the torque deviation value is less than zero and less than the second calibration limit, it is judged that the negative fuel quantity deviation of the overall fuel injector is too large, and at the same time, a further judgment is made on the overall fuel injector fuel quantity deviation.

[0016] Furthermore, the method for further judging the overall fuel injector fuel quantity deviation is as follows:

[0017] When it is judged that the positive fuel quantity deviation of the overall fuel injector is too large, the second calibration time limit starts to count down simultaneously; when the second calibration time limit ends, if the torque deviation value is still greater than zero and greater than the first calibration limit, it is judged that the overall fuel injector fuel quantity deviation is large.

[0018] When it is judged that the negative fuel quantity deviation of the overall fuel injector is too large, the second calibration time limit starts to count down simultaneously; when the second calibration time limit ends, if the torque deviation value is still less than zero and less than the second calibration limit, it is judged that the overall fuel injector fuel quantity deviation is large.

[0019] Furthermore, the protection measure is as follows:

[0020] When it is judged that the fuel quantity deviation of the single-cylinder injector is large or the fuel quantity deviation of the overall fuel injector is large, a torque limit operation is performed to reduce the fuel injection quantity, and at the same time, an alarm for large fuel quantity deviation is given.

[0021] Furthermore, the method for obtaining the torque deviation value is to obtain the actual torque of the vehicle and calculate the difference between the actual torque and the preset required torque to obtain the torque deviation value.

[0022] Beneficial effects

[0023] The advantages of the present invention are as follows:

[0024] By obtaining the single-cylinder fuel injection quantity correction value and the torque deviation value, triggering the single-cylinder injector fuel quantity deviation fault detection strategy according to the single-cylinder fuel injection quantity correction value to judge the single-cylinder injector fuel quantity deviation, triggering the overall injector fuel quantity deviation detection strategy according to the torque deviation value to judge the overall injector fuel quantity deviation, and triggering the protection measure according to the single-cylinder injector fuel quantity deviation and the overall injector fuel quantity deviation, the problem of fuel quantity deviation of the injector can be detected as early as possible, and the risk of damage to the engine and aftertreatment can be reduced. Description of the drawings

[0025] Figure 1 It is a flowchart of the diagnostic method for excessive fuel quantity deviation of the injector of the present invention. Specific embodiments

[0026] The following will further describe the present invention in conjunction with embodiments, but it does not constitute any limitation to the present invention. Any limited modifications made by anyone within the scope of the claims of the present invention are still within the scope of the claims of the present invention.

[0027] Refer to Figure 1 , a diagnostic method for excessive fuel quantity deviation of the injector of the present invention. The present invention is applied to the national VI heavy and light diesel engine system. The method is to obtain the single-cylinder fuel injection quantity correction value and the torque deviation value, adopt the single-cylinder fuel injection quantity correction value for the single-cylinder injector, trigger the single-cylinder injector fuel quantity deviation fault detection strategy according to the single-cylinder fuel injection quantity correction value to judge the single-cylinder injector fuel quantity deviation, trigger the overall injector fuel quantity deviation detection strategy according to the torque deviation value to judge the overall injector fuel quantity deviation, and trigger the protection measure according to the single-cylinder injector fuel quantity deviation and the overall injector fuel quantity deviation.

[0028] The method for obtaining the torque deviation value is to obtain the actual torque of the vehicle through a neural network, and subtract the preset required torque from the actual torque to obtain the torque deviation value. Obtaining the actual torque of the vehicle through a neural network is a prior art, and the present invention will not expand it too much.

[0029] The single-cylinder injector fuel quantity deviation fault detection strategy is as follows:

[0030] Set the first calibration limit value and the first calibration time limit value. When the single-cylinder fuel injection quantity correction value is greater than zero and greater than the first calibration limit value, it is judged that the positive deviation of the single-cylinder injector fuel quantity is too large, and the first calibration time limit value starts to count; when the first calibration time limit value ends, if the single-cylinder fuel injection quantity correction value is still greater than zero and greater than the first calibration limit value, it is judged that the single-cylinder injector fuel quantity deviation is large.

[0031] When the single-cylinder fuel injection quantity correction value is less than zero and less than the first calibrated limit value, it is determined that the negative fuel quantity deviation of the single-cylinder injector is too large, and the first calibrated time limit starts timing; when the first calibrated time limit ends, and the single-cylinder fuel injection quantity correction value is still less than zero and less than the first calibrated limit value, it is determined that the fuel quantity deviation of the single-cylinder injector is large.

[0032] Regardless of which cylinder injector it is, all injectors are regarded as a whole. The overall fuel quantity deviation detection strategy for the injectors is as follows:

[0033] Set the second calibrated limit value and the second calibrated time limit. When the torque deviation value is greater than zero and greater than the second calibrated limit value, it is determined that the positive fuel quantity deviation of the overall injector is too large, and the second calibrated time limit starts timing; when the second calibrated time limit ends, and the torque deviation value is still greater than zero and greater than the first calibrated limit value, it is determined that the fuel quantity deviation of the overall injector is large.

[0034] When the torque deviation value is less than zero and less than the second calibrated limit value, it is determined that the negative fuel quantity deviation of the overall injector is too large, and the second calibrated time limit starts timing; when the second calibrated time limit ends, and the torque deviation value is still less than zero and less than the second calibrated limit value, it is determined that the fuel quantity deviation of the overall injector is large.

[0035] The protection measure is that when the fuel quantity deviation of the single-cylinder injector is large fuel quantity deviation of the single-cylinder injector or the fuel quantity deviation of the overall injector is large fuel quantity deviation of the overall injector, a torque limit operation is performed to reduce the fuel injection quantity, and at the same time, an alarm for large fuel quantity deviation is given to remind the user to perform maintenance to ensure that the engine and aftertreatment are not damaged. The torque limit operation is an existing technology that ensures the vehicle runs smoothly under specific conditions by restricting the engine torque output.

[0036] The above are only the preferred embodiments of the present invention. It should be pointed out that for those skilled in the art, without departing from the structure of the present invention, several deformations and improvements can be made, which will not affect the implementation effect of the present invention and the practicality of the patent.

Claims

1. A method for diagnosing excessive deviation of fuel injection amount of a fuel injector, characterized in that: The method comprises the following steps: obtaining a single-cylinder fuel injection quantity correction value and a torque deviation value, triggering a single-cylinder injector fuel quantity deviation fault detection strategy according to the single-cylinder fuel injection quantity correction value to determine the single-cylinder injector fuel quantity deviation, triggering an overall injector fuel quantity deviation detection strategy according to the torque deviation value to determine the overall injector fuel quantity deviation, and triggering protective measures according to the single-cylinder injector fuel quantity deviation and the overall injector fuel quantity deviation.

2. A method for diagnosing excessive deviation of fuel injection amount of a fuel injector according to claim 1, characterized in that: The single cylinder injector oil quantity deviation fault detection strategy is: A first calibration limit is set, and when the single-cylinder fuel injection amount correction value is greater than zero and greater than the first calibration limit, it is judged that the positive deviation of the fuel amount of the single-cylinder fuel injector is too large, and further judgment is made on the fuel amount deviation of the single-cylinder fuel injector; When the single-cylinder fuel injection quantity correction value is less than zero and less than the first calibration limit, it is determined that the negative deviation of the single-cylinder fuel injector fuel quantity is too large, and further judgment is made on the single-cylinder fuel injector fuel quantity deviation.

3. A method for diagnosing excessive deviation of fuel injection amount of a fuel injector according to claim 2, characterized in that: The method for further judging the oil quantity deviation of the single cylinder injector is as follows: A first calibration time limit is set, and when it is determined that the positive deviation of the oil quantity of the single-cylinder injector is too large, the first calibration time limit starts timing; when the first calibration time limit ends, if the correction value of the single-cylinder injection quantity is still greater than zero and greater than the first calibration limit, it is determined that the oil quantity deviation of the single-cylinder injector is large; When it is determined that the negative deviation of the oil quantity of the single-cylinder injector is too large, the first calibrated time limit starts timing at the same time; when the first calibrated time limit ends, if the single-cylinder injection quantity correction value is still less than zero and less than the first calibrated limit, it is determined that the oil quantity deviation of the single-cylinder injector is large.

4. A method for diagnosing excessive deviation of fuel injection amount of a fuel injector according to claim 1, characterized in that: The overall injector oil quantity deviation detection strategy is: A second calibration limit is set, and when the torque deviation value is greater than zero and greater than the second calibration limit, it is determined that the positive deviation of the overall injector oil quantity is too large, and further determination is made on the overall injector oil quantity deviation; When the torque deviation value is less than zero and less than a second calibration limit, it is determined that the negative deviation of the overall injector oil quantity is too large, and further determination is made on the overall injector oil quantity deviation.

5. A method for diagnosing excessive deviation of fuel injection amount of a fuel injector according to claim 4, characterized in that: The method for further judging the overall injector oil quantity deviation is: When it is determined that the positive deviation of the overall injector oil quantity is too large, the second calibration time limit starts timing; when the second calibration time limit ends, if the torque deviation value is still greater than zero and greater than the first calibration limit, it is determined that the overall injector oil quantity deviation is large; When it is determined that the negative deviation of the overall injector oil quantity is too large, the second calibrated time limit starts timing; when the second calibrated time limit ends, if the torque deviation value is still less than zero and less than the second calibrated limit, it is determined that the overall injector oil quantity deviation is large.

6. A method for diagnosing excessive deviation of fuel injection amount of a fuel injector according to claim 1, characterized in that: The protection measures are: When it is determined that the oil quantity deviation of the single-cylinder injector is large or the oil quantity deviation of the entire injector is large, a torque limiting operation is performed to reduce the injection quantity, and a large oil quantity deviation alarm is issued at the same time.

7. The method for diagnosing excessive deviation of fuel injection amount of a fuel injector according to claim 1, characterized in that: The method for obtaining the torque deviation value is to obtain the actual torque of the vehicle, and to obtain the torque deviation value by subtracting the actual torque from a preset required torque.

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