Implementation method of intake valve lift curve for improving flow coefficient and tumble ratio

Abstract

The present invention provides a method for implementing an intake valve lift curve to improve the flow coefficient and tumble ratio. By detecting the valve mechanism and crankshaft mechanism of an internal combustion engine, it is determined whether the working states of the valve mechanism and crankshaft mechanism are normal, and whether the air passage of the internal combustion engine is currently unobstructed. When the internal combustion engine enters the normal operation stage, valve lift data and crankshaft angle data are periodically collected to generate the current valve lift curve of the valve mechanism. The current valve lift curve is compared with the desired valve lift curve. Thus, when the current overall working state of the internal combustion engine is abnormal, the valve lift values of the valve mechanism at different crankshaft angle intervals are adjusted, so that the valve lift curve is transformed into a curve shape with a "convex" type. In this way, the maximum tumble ratio is achieved in the combustion chamber at the small valve lift stage, and the maximum flow coefficient is achieved in the combustion chamber at the medium and high valve lift stages, thereby maximizing the working efficiency of the internal combustion engine.

Description

Technical Field

[0001] The present invention relates to the technical field of internal combustion engine valve mechanism control, and particularly to a method for implementing an intake valve lift curve for improving the flow coefficient and tumble ratio. Background Art

[0002] During the working process of an engine combustion system such as an internal combustion engine, it is necessary to reasonably control the working process of the air passage and the combustion chamber so that the air entering the combustion chamber through the air passage can be fully mixed with the atomized gasoline to ensure full combustion inside the combustion chamber. In order to maximize the combustion efficiency inside the combustion chamber, it is necessary to adaptively increase the corresponding flow coefficient and tumble ratio when the valve mechanism of the combustion engine is at different valve lift stages. The flow coefficient is a characterization value of the impulse of the air entering the combustion chamber, and the tumble ratio is a characterization value of the turbulent kinetic energy of the atomized gasoline. The adjustment of the flow coefficient and the tumble ratio can be achieved by changing the curve shape of the valve lift curve of the valve mechanism. However, there is currently no related solution to improve the working efficiency of an internal combustion engine by changing the curve shape of the valve lift curve. Summary of the Invention

[0003] Aiming at the defects existing in the prior art, the present invention provides a method for implementing an intake valve lift curve for improving the flow coefficient and tumble ratio. By detecting the valve mechanism and the crankshaft mechanism of the internal combustion engine, it is judged whether the working states of the valve mechanism and the crankshaft mechanism are normal, and whether the air passage of the internal combustion engine is currently unobstructed; when the internal combustion engine enters the normal operation stage, the valve lift data and the crankshaft rotation angle data are periodically collected to generate the current valve lift curve of the valve mechanism; the current valve lift curve is compared with the expected valve lift curve, so that when the current overall working state of the internal combustion engine is abnormal, the valve lift value of the valve mechanism at different crankshaft rotation angle intervals is adjusted, so as to transform the valve lift curve into a curve shape with a "convex" shape, so that the combustion chamber realizes the maximum tumble ratio in the small valve lift stage and the maximum flow coefficient in the medium and high valve lift stages, thereby maximizing the working efficiency of the internal combustion engine.

[0004] The present invention provides a method for implementing an intake valve lift curve for improving the flow coefficient and tumble ratio, which includes the following steps:

[0005] Step S1, when the internal combustion engine starts, detect the valve mechanism and the crankshaft mechanism of the internal combustion engine, and judge whether the working states of the valve mechanism and the crankshaft mechanism are normal; when both the valve mechanism and the crankshaft mechanism are in the normal working state, collect the real-time flow coefficient and the real-time tumble ratio of the internal combustion engine, so as to judge whether the air passage of the internal combustion engine is currently in an unobstructed state;

[0006] Step S2, when the air passage of the internal combustion engine is currently in an unobstructed state, instruct the internal combustion engine to enter the normal operation stage, and periodically collect the valve lift data of the valve mechanism and the crank angle data of the crankshaft mechanism; according to the valve lift data and the crank angle data, generate the current valve lift curve of the valve mechanism;

[0007] Step S3, analyze and process the current valve lift curve to determine the difference information between the current valve lift curve and the expected valve lift curve; and judge whether the current overall working state of the internal combustion engine is normal according to the difference information;

[0008] Step S4, if the current overall working state of the internal combustion engine is abnormal, when the crankshaft mechanism is in different crank angle intervals, adjust the valve lift value of the valve mechanism, so that the valve lift curve of the valve structure changes from a smooth connecting curve shape to a curve shape with a "convex" shape.

[0009] Further, in the step S1, when the internal combustion engine starts, detect the valve mechanism and the crankshaft mechanism of the internal combustion engine, and judge whether the working states of the valve mechanism and the crankshaft mechanism are normal specifically includes:

[0010] When the internal combustion engine starts and enters the preheating stage, collect the cam rotation angular velocity data of the valve mechanism of the internal combustion engine and the crank rotation angular velocity data of the crankshaft mechanism of the internal combustion engine;

[0011] Analyze and process the cam rotation angular velocity data and the crank rotation angular velocity data respectively to obtain the instantaneous rotation angular velocity values in different rotation angle intervals during the complete rotation of the cam of the valve mechanism, and the instantaneous rotation angular velocity values in different rotation angle intervals during the complete rotation of the crankshaft of the crankshaft mechanism;

[0012] If the instantaneous rotation angular velocity value corresponding to the cam satisfies the first preset rotation angular velocity distribution condition, it is judged that the working state of the valve mechanism is normal; otherwise, it is judged that the working state of the valve mechanism is abnormal;

[0013] If the instantaneous rotation angular velocity value corresponding to the crankshaft satisfies the second preset rotation angular velocity distribution condition, it is judged that the working state of the crankshaft mechanism is normal; otherwise, it is judged that the working state of the crankshaft mechanism is abnormal.

[0014] Further, in the step S1, analyze and process the cam rotation angular velocity data and the crank rotation angular velocity data respectively to obtain the instantaneous rotation angular velocity values in different rotation angle intervals during the complete rotation of the cam of the valve mechanism, and the instantaneous rotation angular velocity values in different rotation angle intervals during the complete rotation of the crankshaft of the crankshaft mechanism specifically includes:

[0015] Step S101: Using the following formula (1), based on the cam rotational angular velocity data and the crankshaft rotational angular velocity data, obtain the angular acceleration weight values within each system acquisition period in different rotational angle intervals during one complete rotation of the cam of the valve mechanism, and the angular acceleration weight values within each system acquisition period in different rotational angle intervals during one complete rotation of the crankshaft of the crankshaft mechanism.

[0016]

[0017] In the above formula (1), G m_i (a) represents the angular acceleration weight value within the a-th system acquisition period in the i-th different rotational angle interval during one complete rotation of the cam of the valve mechanism; G z_i (a) represents the angular acceleration weight value within the a-th system acquisition period in the i-th different rotational angle interval during one complete rotation of the crankshaft of the crankshaft mechanism; T represents the system acquisition period; ω m_i (a×T) represents the angular velocity value collected in the a-th system acquisition period in the i-th different rotational angle interval in the cam rotational angular velocity data; ω m_i [(a - 1)×T] represents the angular velocity value collected in the (a - 1)-th system acquisition period in the i-th different rotational angle interval in the cam rotational angular velocity data; ω z_i (a×T) represents the angular velocity value collected in the a-th system acquisition period in the i-th different rotational angle interval in the crankshaft rotational angular velocity data; ω z_i [(a - 1)×T] represents the angular velocity value collected in the (a - 1)-th system acquisition period in the i-th different rotational angle interval in the crankshaft rotational angular velocity data; n(i) represents the total number of angular velocities collected in the i-th different rotational angle interval.

[0018] Step S102: Using the following formula (2), based on the angular acceleration weight values within each system acquisition period in different rotational angle intervals during one complete rotation of the cam of the valve mechanism, and the angular acceleration weight values within each system acquisition period in different rotational angle intervals during one complete rotation of the crankshaft of the crankshaft mechanism, obtain the weighted average angular acceleration values within each system acquisition period in different rotational angle intervals during one complete rotation of the cam of the valve mechanism, and the weighted average angular acceleration values within each system acquisition period in different rotational angle intervals during one complete rotation of the crankshaft of the crankshaft mechanism.

[0019]

[0020] In the above formula (2), e m(i) represents the weighted average angular acceleration value within the i-th different rotation angle interval during one complete rotation of the cam of the valve mechanism; e z (i) represents the weighted average angular acceleration value within the i-th different rotation angle interval during one complete rotation of the crankshaft of the crankshaft mechanism;

[0021] Step S103, using the following formula (3), based on the weighted average angular acceleration values within different rotation angle intervals during one complete rotation of the cam of the valve mechanism and the weighted average angular acceleration values within different rotation angle intervals during one complete rotation of the crankshaft of the crankshaft mechanism, obtain the instantaneous rotational angular velocity values within different rotation angle intervals during one complete rotation of the cam of the valve mechanism and the instantaneous rotational angular velocity values within different rotation angle intervals during one complete rotation of the crankshaft of the crankshaft mechanism,

[0022]

[0023] In the above formula (3), W m (i) represents the instantaneous rotational angular velocity value within the i-th different rotation angle interval during one complete rotation of the cam of the valve mechanism; W z (i) represents the instantaneous rotational angular velocity value within the i-th different rotation angle interval during one complete rotation of the crankshaft of the crankshaft mechanism; θ m (i) represents the angle value rotated within the i-th different rotation angle interval during one complete rotation of the cam of the valve mechanism; θ z (i) represents the angle value rotated within the i-th different rotation angle interval during one complete rotation of the crankshaft of the crankshaft mechanism.

[0024] Further, in the step S1, when both the valve mechanism and the crankshaft mechanism are in a normal working state, collect the real-time flow coefficient and real-time tumble ratio of the internal combustion engine, and thereby determine whether the air passage of the internal combustion engine is currently in an unobstructed state, which specifically includes:

[0025] When the valve mechanism or the crankshaft mechanism is in an abnormal working state, then instruct the internal combustion engine to stop working;

[0026] When both the valve mechanism and the crankshaft mechanism are in a normal working state, then collect the real-time flow coefficient data and real-time tumble ratio data of the internal combustion engine within a preset time period; based on the real-time flow coefficient data and the real-time tumble ratio data, obtain the average flow coefficient value and average tumble ratio value within the preset time period;

[0027] If the average flow coefficient value is not within the preset flow coefficient range and the average tumble ratio is not within the preset tumble ratio range, it is determined that the air passage of the internal combustion engine is currently in an unobstructed state; otherwise, it is determined that the air passage of the internal combustion engine is not currently in an unobstructed state.

[0028] Further, in the step S2, when the air passage of the internal combustion engine is currently in an unobstructed state, instructing the internal combustion engine to enter the normal operation stage and periodically collecting the valve lift data of the valve mechanism and the crank angle data of the crankshaft mechanism specifically includes:

[0029] When the air passage of the internal combustion engine is not currently in an unobstructed state, the internal combustion engine is instructed to stop working;

[0030] When the air passage of the internal combustion engine is currently in an unobstructed state, the internal combustion engine is instructed to switch from the preheating stage to the normal operation stage, and the valve lift data and the crank angle data are respectively and periodically collected through the valve movement amplitude sensor installed on the valve mechanism and the crankshaft rotation sensor installed on the crankshaft mechanism.

[0031] Further, in the step S2, generating the current valve lift curve of the valve mechanism according to the valve lift data and the crank angle data specifically includes:

[0032] Taking the acquisition time of each data value in the valve lift data and the crank angle data as the association, constructing a one-to-one correspondence relationship of the data values for the valve lift data and the crank angle data, and then generating the current valve lift curve of the valve mechanism according to the one-to-one correspondence relationship of the data values.

[0033] Further, in the step S3, analyzing and processing the current valve lift curve to determine the difference information between the current valve lift curve and the expected valve lift curve specifically includes:

[0034] According to the magnitude of the valve lift value, the current valve lift curve and the expected valve lift curve are respectively divided into a small valve lift stage sub-curve and a medium-high valve lift stage sub-curve;

[0035] Determining the tumble ratio difference information between the small valve lift stage sub-curve of the current valve lift curve and the small valve lift stage sub-curve of the expected valve lift curve;

[0036] Determining the flow coefficient difference information between the medium-high valve lift stage sub-curve of the current valve lift curve and the medium-high valve lift stage curve of the expected valve lift curve.

[0037] Further, in the step S3, judging whether the current overall working state of the internal combustion engine is normal according to the difference information specifically includes:

[0038] If the tumble ratio difference information indicates that the tumble ratio of the sub - curve in the small valve lift stage of the current valve lift curve is less than that of the sub - curve in the small valve lift stage of the expected valve lift curve, it is determined that the current overall working state of the internal combustion engine is abnormal;

[0039] Or,

[0040] If the flow coefficient difference information indicates that the flow coefficient of the sub - curve in the small valve lift stage of the current valve lift curve is less than that of the sub - curve in the small valve lift stage of the expected valve lift curve, it is determined that the current overall working state of the internal combustion engine is abnormal.

[0041] Further, in the step S4, if the current overall working state of the internal combustion engine is abnormal, when the crankshaft mechanism is in different crankshaft angle intervals, the valve lift value of the valve mechanism is adjusted, so that the valve lift curve of the valve structure is changed from a smoothly connected curve shape to a curve shape with a "convex" type, which specifically includes:

[0042] If the current overall working state of the internal combustion engine is abnormal, when the crankshaft angle is in the interval of [320°, 350°), it is indicated that the valve lift is maintained at 2.7 mm; when the crankshaft angle is in the interval of [350°, 510°), it is indicated that the valve lift first linearly increases from 2.7 mm to 9.3 mm and then remains at 9.3 mm; when the crankshaft angle is in the interval of [510°, 560°], it is indicated that the valve lift decreases and remains at 2.7 mm, so that the valve lift curve of the valve structure is changed from a smoothly connected curve shape to a curve shape with a "convex" type.

[0043] Compared with the prior art, this method for implementing the intake valve lift curve for improving the flow coefficient and tumble ratio detects the valve mechanism and crankshaft mechanism of the internal combustion engine to determine whether the working states of the valve mechanism and crankshaft mechanism are normal, and whether the air passage of the internal combustion engine is currently unobstructed; when the internal combustion engine enters the normal operation stage, the valve lift data and crankshaft angle data are periodically collected to generate the current valve lift curve of the valve mechanism; the current valve lift curve is compared with the expected valve lift curve, so that when the current overall working state of the internal combustion engine is abnormal, the valve lift value of the valve mechanism is adjusted when it is in different crankshaft angle intervals, so that the valve lift curve is changed to a curve shape with a "convex" type, so that the maximum tumble ratio is achieved in the combustion chamber in the small valve lift stage, and the maximum flow coefficient is achieved in the combustion chamber in the medium - high valve lift stage, thereby maximizing the working efficiency of the internal combustion engine.

[0044] Other features and advantages of the present invention will be set forth in the following description, and in part will be obvious from the description, or may be learned by practice of the present invention. The objectives and other advantages of the present invention may be realized and attained by the structure particularly pointed out in the written description, claims, as well as the drawings.

[0045] The technical solution of the present invention will be further described in detail below with reference to the drawings and embodiments. Description of the Drawings

[0046] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or in the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention, and for those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0047] Figure 1 It is a schematic flow chart of the implementation method of the intake valve lift curve for improving the flow coefficient and tumble ratio provided by the present invention.

[0048] Figure 2 It is a schematic comparison diagram between the traditional valve lift curve and the "convex" valve lift curve in the implementation method of the intake valve lift curve for improving the flow coefficient and tumble ratio provided by the present invention. Detailed Embodiments

[0049] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, rather than all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0050] Refer to Figure 1 , which is a schematic flow chart of the implementation method of the intake valve lift curve for improving the flow coefficient and tumble ratio provided by the embodiments of the present invention. The implementation method of the intake valve lift curve for improving the flow coefficient and tumble ratio includes the following steps:

[0051] Step S1, when the internal combustion engine starts, detect the valve mechanism and the crankshaft mechanism of the internal combustion engine to determine whether the working states of the valve mechanism and the crankshaft mechanism are normal; when both the valve mechanism and the crankshaft mechanism are in normal working states, collect the real-time flow coefficient and the real-time tumble ratio of the internal combustion engine to determine whether the air passage of the internal combustion engine is currently in a smooth state;

[0052] Step S2, when the air passage of the internal combustion engine is currently in an unobstructed state, instruct the internal combustion engine to enter the normal operation stage, and periodically collect the valve lift data of the valve mechanism and the crank angle data of the crankshaft mechanism; according to the valve lift data and the crank angle data, generate the current valve lift curve of the valve mechanism.

[0053] Step S3, analyze and process the current valve lift curve to determine the difference information between the current valve lift curve and the expected valve lift curve; and based on the difference information, judge whether the current overall working state of the internal combustion engine is normal.

[0054] Step S4, if the current overall working state of the internal combustion engine is abnormal, when the crankshaft mechanism is in different crank angle intervals, adjust the valve lift value of the valve mechanism, so that the valve lift curve of the valve structure changes from a smoothly connected curve shape to a curve shape with a "convex" type.

[0055] The beneficial effects of the above technical solution are as follows: The implementation method of the intake valve lift curve for improving the flow coefficient and tumble ratio detects the valve mechanism and the crankshaft mechanism of the internal combustion engine to judge whether the working states of the valve mechanism and the crankshaft mechanism are normal, and whether the air passage of the internal combustion engine is currently unobstructed; when the internal combustion engine enters the normal operation stage, periodically collect the valve lift data and the crank angle data to generate the current valve lift curve of the valve mechanism; compare the current valve lift curve with the expected valve lift curve, and when the current overall working state of the internal combustion engine is abnormal, adjust the valve lift value of the valve mechanism when it is in different crank angle intervals, so as to change the valve lift curve into a curve shape with a "convex" type, so that the combustion chamber achieves the maximum tumble ratio in the small valve lift stage and the maximum flow coefficient in the medium and high valve lift stages, thereby maximizing the working efficiency of the internal combustion engine.

[0056] Preferably, in step S1, when the internal combustion engine is started, detecting the valve mechanism and the crankshaft mechanism of the internal combustion engine to judge whether the working states of the valve mechanism and the crankshaft mechanism are normal specifically includes:

[0057] When the internal combustion engine is started and enters the preheating stage, collect the cam rotation angular velocity data of the valve mechanism of the internal combustion engine and the crank rotation angular velocity data of the crankshaft mechanism of the internal combustion engine.

[0058] Analyze and process the cam rotation angular velocity data and the crank rotation angular velocity data respectively to obtain the instantaneous rotation angular velocity values of the cam in different rotation angle intervals during one complete rotation of the valve mechanism, and the instantaneous rotation angular velocity values of the crankshaft in different rotation angle intervals during one complete rotation of the crankshaft mechanism.

[0059] If the instantaneous rotational angular velocity value corresponding to the cam satisfies the first preset rotational angular velocity distribution condition, it is determined that the working state of the valve mechanism is normal; otherwise, it is determined that the working state of the valve mechanism is abnormal;

[0060] If the instantaneous rotational angular velocity value corresponding to the crankshaft satisfies the second preset rotational angular velocity distribution condition, it is determined that the working state of the crankshaft mechanism is normal; otherwise, it is determined that the working state of the crankshaft mechanism is abnormal.

[0061] The beneficial effects of the above technical solution are as follows: When the internal combustion engine starts, it will first enter the corresponding preheating stage. During this preheating stage, the valve mechanism and the crankshaft mechanism of the internal combustion engine will also enter the working state accordingly. At this time, the cam rotation angular velocity data of the valve mechanism and the crankshaft rotation angular velocity data of the crankshaft mechanism of the internal combustion engine are respectively collected through the cam rotation sensors and the crankshaft rotation sensors pre-installed in the valve mechanism and the crankshaft mechanism. Then, the collected cam rotation angular velocity data and crankshaft rotation angular velocity data are analyzed and processed to determine the instantaneous rotational angular velocity values of the cam and the crankshaft respectively. In this way, the rotational angular velocity distribution of the cam and the crankshaft corresponding to different rotational angle intervals during a complete rotation can be obtained, so as to comprehensively analyze the rotational speed of the cam and the crankshaft. In addition, the first preset rotational angular velocity distribution condition refers to the rotational angular velocity range corresponding to different rotational angle positions of the cam during a complete rotation, and the second preset rotational angular velocity distribution condition refers to the rotational angular velocity range corresponding to different rotational angle positions of the crankshaft during a complete rotation; when the instantaneous rotational angular velocity value corresponding to the cam in different rotational angle intervals matches the rotational angular velocity range defined in the first preset rotational angular velocity distribution condition, it is determined that the working state of the valve mechanism is normal; when the instantaneous rotational angular velocity value corresponding to the crankshaft in different rotational angle intervals matches the rotational angular velocity range defined in the second preset rotational angular velocity distribution condition, it is determined that the working state of the crankshaft mechanism is normal. In this way, the rotational states of the valve mechanism and the crankshaft mechanism can be quickly judged for their working states.

[0062] Preferably, in step S1, the cam rotation angular velocity data and the crankshaft rotation angular velocity data are respectively analyzed and processed to obtain the instantaneous rotational angular velocity values of the cam of the valve mechanism in different rotational angle intervals during a complete rotation of the cam, and the instantaneous rotational angular velocity values of the crankshaft of the crankshaft mechanism in different rotational angle intervals during a complete rotation of the crankshaft, specifically including:

[0063] Step S101, using the following formula (1), obtain the angular acceleration weight values within each system acquisition period in different rotation angle intervals during one complete rotation of the cam of the valve mechanism, and the angular acceleration weight values within each system acquisition period in different rotation angle intervals during one complete rotation of the crankshaft of the crankshaft mechanism, based on the cam rotation angular velocity data and the crankshaft rotation angular velocity data.

[0064]

[0065] In the above formula (1), G m_i (a) represents the angular acceleration weight value within the a-th system acquisition period in the i-th different rotation angle interval during one complete rotation of the cam of the valve mechanism; G z_i (a) represents the angular acceleration weight value within the a-th system acquisition period in the i-th different rotation angle interval during one complete rotation of the crankshaft of the crankshaft mechanism; T represents the system acquisition period; ω m_i (a×T) represents the angular velocity value collected in the a-th system acquisition period within the i-th different rotation angle interval in the cam rotation angular velocity data; ω m_i [(a - 1)×T] represents the angular velocity value collected in the (a - 1)-th system acquisition period within the i-th different rotation angle interval in the cam rotation angular velocity data; ω z_i (a×T) represents the angular velocity value collected in the a-th system acquisition period within the i-th different rotation angle interval in the crankshaft rotation angular velocity data; ω z_i [(a - 1)×T] represents the angular velocity value collected in the (a - 1)-th system acquisition period within the i-th different rotation angle interval in the crankshaft rotation angular velocity data; n(i) represents the total number of angular velocities collected in the i-th different rotation angle interval.

[0066] Step S102, using the following formula (2), obtain the weighted average angular acceleration values within different rotation angle intervals during one complete rotation of the cam of the valve mechanism, and the weighted average angular acceleration values within different rotation angle intervals during one complete rotation of the crankshaft of the crankshaft mechanism, based on the angular acceleration weight values within each system acquisition period in different rotation angle intervals during one complete rotation of the cam of the valve mechanism and the angular acceleration weight values within each system acquisition period in different rotation angle intervals during one complete rotation of the crankshaft of the crankshaft mechanism.

[0067]

[0068] In the above formula (2), e m (i) represents the weighted average angular acceleration value within the i-th different rotation angle interval during one complete rotation of the cam of the valve mechanism; ez (i) represents the weighted average angular acceleration value within the i-th different rotation angle interval during one complete rotation of the crankshaft of the crankshaft mechanism;

[0069] Step S103, using the following formula (3), based on the weighted average angular acceleration values within different rotation angle intervals during one complete rotation of the cam of the valve mechanism and the weighted average angular acceleration values within different rotation angle intervals during one complete rotation of the crankshaft of the crankshaft mechanism, obtain the instantaneous rotational angular velocity values within different rotation angle intervals during one complete rotation of the cam of the valve mechanism and the instantaneous rotational angular velocity values within different rotation angle intervals during one complete rotation of the crankshaft of the crankshaft mechanism,

[0070]

[0071] In the above formula (3), W m (i) represents the instantaneous rotational angular velocity value within the i-th different rotation angle interval during one complete rotation of the cam of the valve mechanism; W z (i) represents the instantaneous rotational angular velocity value within the i-th different rotation angle interval during one complete rotation of the crankshaft of the crankshaft mechanism; θ m (i) represents the angle value rotated within the i-th different rotation angle interval during one complete rotation of the cam of the valve mechanism; θ z (i) represents the angle value rotated within the i-th different rotation angle interval during one complete rotation of the crankshaft of the crankshaft mechanism.

[0072] The beneficial effects of the above technical solution are as follows: By using the above formula (1), based on the cam rotation angular velocity data and the crankshaft rotation angular velocity data, the angular acceleration weight values within each system acquisition period in different rotation angle intervals during one complete rotation of the cam of the valve mechanism are obtained, as well as the angular acceleration weight values within each system acquisition period in different rotation angle intervals during one complete rotation of the crankshaft of the crankshaft mechanism. Thus, the angular velocity collected at each acquisition point is transformed into angular acceleration to know the change rate of its angular velocity. Then, according to the situation of the change rate, the corresponding weights are obtained to ensure the accuracy when calculating the instantaneous angular velocity subsequently. Then, by using the above formula (2), based on the angular acceleration weight values within each system acquisition period in different rotation angle intervals during one complete rotation of the cam of the valve mechanism and the angular acceleration weight values within each system acquisition period in different rotation angle intervals during one complete rotation of the crankshaft of the crankshaft mechanism, the weighted average angular acceleration values within each system acquisition period in different rotation angle intervals during one complete rotation of the cam of the valve mechanism and the weighted average angular acceleration values within each system acquisition period in different rotation angle intervals during one complete rotation of the crankshaft of the crankshaft mechanism are obtained. Thus, the angular velocity at each acquisition point is transformed into angular acceleration and the weighted average angular acceleration value of the entire rotation angle interval is obtained according to the weight of each acquisition point, making the calculation result more reasonable and more in line with the actual situation. Finally, by using the above formula (3), based on the weighted average angular acceleration values within each system acquisition period in different rotation angle intervals during one complete rotation of the cam of the valve mechanism and the weighted average angular acceleration values within each system acquisition period in different rotation angle intervals during one complete rotation of the crankshaft of the crankshaft mechanism, the instantaneous rotation angular velocity values within each system acquisition period in different rotation angle intervals during one complete rotation of the cam of the valve mechanism and the instantaneous rotation angular velocity values within each system acquisition period in different rotation angle intervals during one complete rotation of the crankshaft of the crankshaft mechanism are obtained. Thus, the instantaneous rotation angular velocity is obtained by combining angular acceleration and angle, which can avoid the inaccuracy of the instantaneous rotation angular velocity caused by the fluctuation of a single acquisition point and can reflect the angular velocity situation of each acquisition point from multiple aspects at the same time.

[0073] Preferably, in this step S1, when both the valve mechanism and the crankshaft mechanism are in a normal working state, the real-time flow coefficient and the real-time tumble ratio of the internal combustion engine are collected to determine whether the air passage of the internal combustion engine is currently in an unobstructed state, which specifically includes:

[0074] When either the valve mechanism or the crankshaft mechanism is in an abnormal working state, it is indicated that the internal combustion engine stops working;

[0075] When both the valve mechanism and the crankshaft mechanism are in a normal working state, the real-time flow coefficient data and the real-time tumble ratio data of the internal combustion engine within a preset time period are collected; according to the real-time flow coefficient data and the real-time tumble ratio data, the average flow coefficient value and the average tumble ratio value within the preset time period are obtained;

[0076] If the average flow coefficient value is not within the preset flow coefficient range and the average tumble ratio value is not within the preset tumble ratio range, it is determined that the air passage of the internal combustion engine is currently in an unobstructed state; otherwise, it is determined that the air passage of the internal combustion engine is currently not in an unobstructed state.

[0077] The beneficial effects of the above technical solution are as follows: Since both the flow coefficient and the tumble ratio are used to measure the thermodynamic state of the combustible mixture inside the combustion chamber, and the air passage of the internal combustion engine is used to input air into the combustion chamber of the internal combustion engine for auxiliary combustion, when the air passage is blocked and unobstructed, the amount of air input into the combustion chamber will also decrease accordingly. At this time, the flow coefficient and the tumble ratio inside the combustion chamber will also change. Through the above method, according to the relationship between the average flow coefficient value and the average tumble ratio value within the preset time period and the preset flow coefficient range and the preset tumble ratio range, it is possible to infer reversely whether the air passage of the internal combustion engine is currently unobstructed, thus ensuring the reliability of the air delivery of the internal combustion engine air passage.

[0078] Preferably, in the step S2, when the air passage of the internal combustion engine is currently in an unobstructed state, instructing the internal combustion engine to enter the normal operation stage and periodically collecting the valve lift data of the valve mechanism and the crank angle data of the crankshaft mechanism specifically includes:

[0079] When the air passage of the internal combustion engine is currently not in an unobstructed state, instruct the internal combustion engine to stop working;

[0080] When the air passage of the internal combustion engine is currently in an unobstructed state, instruct the internal combustion engine to switch from the preheating stage to the normal operation stage, and periodically collect the valve lift data and the crank angle data through the valve movement amplitude sensor installed on the valve mechanism and the crankshaft rotation sensor installed on the crankshaft mechanism respectively.

[0081] The beneficial effects of the above technical solution are as follows: Through the above method, when the air passage of the internal combustion engine is unobstructed, the internal combustion engine is stopped in time to avoid irreversible damage to the internal combustion engine in the future; when the air passage of the internal combustion engine is unobstructed, instruct the internal combustion engine to switch from the preheating stage to the normal operation stage, which can ensure that the internal combustion engine continuously outputs power to the outside world. At this time, by collecting the valve lift data and the crank angle data through the valve movement amplitude sensor and the crankshaft rotation sensor respectively, continuous and stable monitoring of the valve mechanism and the crankshaft mechanism can be realized; among them, the valve movement amplitude sensor can be, but is not limited to, a displacement sensor installed on the valve, and the crankshaft rotation sensor can be, but is not limited to, an angular velocity sensor installed on the crankshaft.

[0082] Preferably, in the step S2, generating the current valve lift curve of the valve mechanism according to the valve lift data and the crank angle data specifically includes:

[0083] Taking the acquisition time of each data value in the valve lift data and the crankshaft rotation angle data as the association, a one-to-one correspondence relationship of data values for the valve lift data and the crankshaft rotation angle data is constructed. Then, according to the one-to-one correspondence relationship of data values, a valve lift curve of the current valve mechanism is generated.

[0084] The beneficial effects of the above technical solution are as follows: Since the valve lift data and the crankshaft rotation angle data are both acquired within a preset time period, taking the same acquisition time point as the association, the valve lift data value and the crankshaft rotation angle data value acquired at the same acquisition time point are corresponding. In this way, a number of data pairs of valve lift data values and crankshaft rotation angle data values can be formed. Then, according to the number of data pairs, a valve lift curve in a coordinate system with the crankshaft rotation angle as the abscissa and the valve lift as the ordinate is obtained.

[0085] Preferably, in step S3, analyzing and processing the current valve lift curve to determine the difference information between the current valve lift curve and the expected valve lift curve specifically includes:

[0086] According to the magnitude of the valve lift value, the current valve lift curve and the expected valve lift curve are respectively divided into a sub-curve of the small valve lift stage and a sub-curve of the medium-high valve lift stage;

[0087] Determining the tumble ratio difference information between the sub-curve of the small valve lift stage of the current valve lift curve and the sub-curve of the small valve lift stage of the expected valve lift curve;

[0088] Determining the flow coefficient difference information between the sub-curve of the medium-high valve lift stage of the current valve lift curve and the curve of the medium-high valve lift stage of the expected valve lift curve.

[0089] The beneficial effects of the above technical solution are as follows: In actual work, a valve lift reference value can be set. The curve part corresponding to the valve lift value less than the valve lift reference value is used as the sub-curve of the small valve lift stage, and the curve part corresponding to the valve lift value greater than or equal to the valve lift reference value is used as the sub-curve of the medium-high valve lift stage. Then, combined with the corresponding thermodynamics analysis principle, the tumble ratio difference information between the sub-curve of the small valve lift stage of the current valve lift curve and the sub-curve of the small valve lift stage of the expected valve lift curve is determined, and the flow coefficient difference information between the sub-curve of the medium-high valve lift stage of the current valve lift curve and the curve of the medium-high valve lift stage of the expected valve lift curve is determined. In this way, the current valve lift curve can be quantitatively identified and judged with the expected valve lift curve as the standard; among them, the expected valve lift curve is an ideal valve lift curve set in advance.

[0090] Preferably, in step S3, judging whether the current overall operating state of the internal combustion engine is normal according to the difference information specifically includes:

[0091] If the tumble ratio difference information indicates that the tumble ratio of the sub - curve in the small valve lift stage of the current valve lift curve is less than that of the sub - curve in the small valve lift stage of the expected valve lift curve, it is judged that the current overall operating state of the internal combustion engine is abnormal;

[0092] Or,

[0093] If the flow coefficient difference information indicates that the flow coefficient of the sub - curve in the small valve lift stage of the current valve lift curve is less than that of the sub - curve in the small valve lift stage of the expected valve lift curve, it is judged that the current overall operating state of the internal combustion engine is abnormal.

[0094] The beneficial effect of the above - mentioned technical solution is: By the above method, the quantitative judgment of the current overall operating state of the internal combustion engine can be carried out, which is convenient for accurately judging whether the current operating state of the internal combustion engine is normal.

[0095] Preferably, in step S4, if the current overall operating state of the internal combustion engine is abnormal, when the crankshaft mechanism is in different crankshaft angle intervals, the valve lift value of the valve mechanism is adjusted, so that the valve lift curve of the valve structure is changed from a smooth connecting curve shape to a curve shape with a "convex" type, specifically including:

[0096] If the current overall operating state of the internal combustion engine is abnormal, when the crankshaft angle is in the interval of [320°, 350°), the valve lift is indicated to be maintained at 2.7 mm; when the crankshaft angle is in the interval of [350°, 510°), the valve lift is indicated to linearly increase from 2.7 mm to 9.3 mm first and then be maintained at 9.3 mm; when the crankshaft angle is in the interval of [510°, 560°], the valve lift is indicated to decrease and be maintained at 2.7 mm, so that the valve lift curve of the valve structure is changed from a smooth connecting curve shape to a curve shape with a "convex" type.

[0097] The beneficial effect of the above - mentioned technical solution is: By the above method, when the current overall operating state of the internal combustion engine is abnormal, when the crankshaft mechanism is in different crankshaft angle intervals, the valve lift value of the valve mechanism is adjusted linearly. In this way, the maximum tumble ratio can be achieved in combination with the combustion chamber air guide screen in the small valve lift stage, and the maximum flow coefficient can be achieved in the medium - high valve lift stage. Using the above valve lift process, the flow coefficient can be maximized and the tumble ratio can be maintained as large as possible.

[0098] Refer to Figure 2, which is a comparison schematic diagram between the traditional valve lift curve and the "convex" valve lift curve in the method for implementing the valve lift curve for improving the flow coefficient and tumble ratio provided by the present invention. In Figure 2 , the abscissa is the crankshaft angle and the ordinate is the valve lift; the traditional valve lift curve is a continuous smooth curve that first rises and then falls, which is represented by a thin solid line; while the "convex" valve lift curve represented by a thick solid line in the figure is the adjusted valve lift curve. Specifically, in the interval where the crankshaft angle is in [320°, 350°), the valve lift is maintained at 2.0 mm - 3.0 mm, preferably 2.7 mm, and the valve is combined with the air guide screen in the combustion chamber to achieve the maximum tumble ratio within this interval; in the interval where the crankshaft angle is in [350°, 510°), the valve maintains a maximum lift of 9.0 mm - 10.0 mm, preferably 9.3 mm, to maximize the flow coefficient, and within this interval, the tumble ratio of the combustion chamber is at a medium to high value; in the interval where the crankshaft angle is in [510°, 560°], the valve lift decreases and is maintained at 2.0 mm - 3.0 mm, preferably 2.7 mm. At this time, the valve is combined with the air guide screen in the combustion chamber to generate a relatively large tumble ratio, and within this interval, the flow coefficient is the same as that in the valve opening stage; finally, at the crankshaft angle of 560°, the valve closes to complete the intake process. In addition, there is a section of inclined linear rise in the "convex" valve lift curve represented by a thick solid line. Through the above section, interference between the piston and the valve of the internal combustion engine can be avoided, and the inclination angle of this section needs to be determined according to the valve lift and valve timing.

[0099] As can be seen from the content of the above embodiments, the method for implementing the valve lift curve for improving the flow coefficient and tumble ratio detects the valve mechanism and crankshaft mechanism of the internal combustion engine to determine whether the working states of the valve mechanism and crankshaft mechanism are normal, and whether the air passage of the internal combustion engine is currently unobstructed; when the internal combustion engine enters the normal operation stage, the valve lift data and crankshaft angle data are periodically collected to generate the current valve lift curve of the valve mechanism; the current valve lift curve is compared with the expected valve lift curve, so that when the current overall working state of the internal combustion engine is abnormal, the valve lift value of the valve mechanism at different crankshaft angle intervals is adjusted, so as to transform the valve lift curve into a curve shape with a "convex" shape. In this way, the maximum tumble ratio is achieved in the combustion chamber in the small valve lift stage, and the maximum flow coefficient is achieved in the combustion chamber in the medium to high valve lift stage, thereby maximizing the working efficiency of the internal combustion engine.

[0100] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalent technologies, the present invention is also intended to include these changes and modifications.

Claims

1. An implementation method of an intake valve lift curve for improving the flow coefficient and tumble ratio, characterized in that It includes the following steps: Step S1: When the internal combustion engine starts, detect the valve mechanism and crankshaft mechanism of the internal combustion engine to determine whether the working states of the valve mechanism and the crankshaft mechanism are normal; when both the valve mechanism and the crankshaft mechanism are in normal working states, collect the real-time flow coefficient and real-time tumble ratio of the internal combustion engine, so as to determine whether the air passage of the internal combustion engine is in an unobstructed state currently; Step S2: When the air passage of the internal combustion engine is in an unobstructed state currently, instruct the internal combustion engine to enter the normal operation stage, and periodically collect the valve lift data of the valve mechanism and the crank angle data of the crankshaft mechanism; according to the valve lift data and the crank angle data, generate the current valve lift curve of the valve mechanism; Step S3: Analyze and process the current valve lift curve to determine the difference information between the current valve lift curve and the expected valve lift curve; and according to the difference information, judge whether the current overall working state of the internal combustion engine is normal; Step S4: If the current overall working state of the internal combustion engine is abnormal, when the crankshaft mechanism is in different crank angle intervals, adjust the valve lift value of the valve mechanism, so that the valve lift curve of the valve mechanism changes from a smooth connected curve shape to a curve shape with a "convex" type; Among them, in the step S1, when the internal combustion engine starts, detecting the valve mechanism and crankshaft mechanism of the internal combustion engine to determine whether the working states of the valve mechanism and the crankshaft mechanism are normal specifically includes: When the internal combustion engine starts and enters the preheating stage, collect the cam rotation angular velocity data of the valve mechanism of the internal combustion engine and the crankshaft rotation angular velocity data of the crankshaft mechanism of the internal combustion engine; Analyze and process the cam rotation angular velocity data and the crankshaft rotation angular velocity data respectively to obtain the instantaneous rotation angular velocity values in different rotation angle intervals during the complete rotation of the cam of the valve mechanism, and the instantaneous rotation angular velocity values in different rotation angle intervals during the complete rotation of the crankshaft of the crankshaft mechanism; If the instantaneous rotation angular velocity value corresponding to the cam meets the first preset rotation angular velocity distribution condition, judge that the working state of the valve mechanism is normal; otherwise, judge that the working state of the valve mechanism is abnormal; If the instantaneous rotation angular velocity value corresponding to the crankshaft meets the second preset rotation angular velocity distribution condition, judge that the working state of the crankshaft mechanism is normal; otherwise, judge that the working state of the crankshaft mechanism is abnormal.

2. The intake valve lift curve implementation method for improving the flow coefficient and tumble ratio as described in claim 1, characterized in that: In the step S1, analyzing and processing the cam rotation angular velocity data and the crankshaft rotation angular velocity data respectively to obtain the instantaneous rotation angular velocity values in different rotation angle intervals during the complete rotation of the cam of the valve mechanism, and the instantaneous rotation angular velocity values in different rotation angle intervals during the complete rotation of the crankshaft of the crankshaft mechanism specifically includes: Step S101: Using the following formula (1), obtain the angular acceleration weight values within each system acquisition period in different rotation angle intervals during one complete rotation of the cam of the valve mechanism, and the angular acceleration weight values within each system acquisition period in different rotation angle intervals during one complete rotation of the crankshaft of the crankshaft mechanism, based on the cam rotation angular velocity data and the crankshaft rotation angular velocity data. In the above formula (1), represents the angular acceleration weight value in the -th different rotation angle interval during one complete rotation of the cam of the valve mechanism in the -th system acquisition cycle; the angular acceleration weight value in the -th different rotation angle interval during one complete rotation of the crankshaft of the crankshaft mechanism in the -th system acquisition cycle; represents the system acquisition cycle; represents the angular velocity value collected in the -th different rotation angle interval and the -th system acquisition cycle in the cam rotation angular velocity data; represents the angular velocity value collected in the -th different rotation angle interval and the -th system acquisition cycle in the cam rotation angular velocity data; represents the angular velocity value collected in the -th different rotation angle interval and the -th system acquisition cycle in the crankshaft rotation angular velocity data; represents the angular velocity value collected in the -th different rotation angle interval and the -th system acquisition cycle in the crankshaft rotation angular velocity data; represents the total number of angular velocities collected in the -th different rotation angle interval; Step S102, using the following formula (2), obtain the weighted average angular acceleration values within different rotation angle intervals during one complete rotation of the cam of the valve mechanism, and the weighted average angular acceleration values within different rotation angle intervals during one complete rotation of the crankshaft of the crankshaft mechanism, according to the angular acceleration weight values within each system acquisition cycle within different rotation angle intervals during one complete rotation of the cam of the valve mechanism, and the angular acceleration weight values within different rotation angle intervals during one complete rotation of the crankshaft of the crankshaft mechanism. In the above formula (2), represents the weighted average angular acceleration value within the th different rotation angle interval during one complete rotation of the cam of the valve mechanism; represents the weighted average angular acceleration value within the th different rotation angle interval during one complete rotation of the crankshaft of the crankshaft mechanism; Step S103: Using the following formula (3), obtain the instantaneous rotation angular velocity values within each system acquisition period in different rotation angle intervals during one complete rotation of the cam of the valve mechanism, and the instantaneous rotation angular velocity values within each system acquisition period in different rotation angle intervals during one complete rotation of the crankshaft of the crankshaft mechanism, based on the weighted average angular acceleration values within each system acquisition period in different rotation angle intervals during one complete rotation of the cam of the valve mechanism and the weighted average angular acceleration values within each system acquisition period in different rotation angle intervals during one complete rotation of the crankshaft of the crankshaft mechanism. In the above formula (3), represents the instantaneous rotational angular velocity value within the th different rotational angle interval during one complete rotation of the cam of the valve mechanism; represents the instantaneous rotational angular velocity value within the th different rotational angle interval during one complete rotation of the crankshaft of the crankshaft mechanism; represents the angle value rotated within the th different rotational angle interval during one complete rotation of the cam of the valve mechanism; represents the angle value rotated within the th different rotational angle interval during one complete rotation of the crankshaft of the crankshaft mechanism.

3. The method for implementing an intake valve lift curve for improving the flow coefficient and tumble ratio as claimed in claim 1, wherein: In step S1, when both the valve mechanism and the crankshaft mechanism are in a normal operating state, collect the real-time flow coefficient and real-time tumble ratio of the internal combustion engine, and the specific method for determining whether the air passage of the internal combustion engine is currently unobstructed includes: When either the valve mechanism or the crankshaft mechanism is in an abnormal operating state, instruct the internal combustion engine to stop working. When both the valve mechanism and the crankshaft mechanism are in a normal operating state, collect the real-time flow coefficient data and real-time tumble ratio data of the internal combustion engine within a preset time period; based on the real-time flow coefficient data and the real-time tumble ratio data, obtain the average flow coefficient value and the average tumble ratio value within the preset time period. If the average flow coefficient value is not within the preset flow coefficient range and the average tumble ratio value is not within the preset tumble ratio range, it is determined that the air passage of the internal combustion engine is currently unobstructed; otherwise, it is determined that the air passage of the internal combustion engine is currently not unobstructed.

4. The method for implementing an intake valve lift curve for improving the flow coefficient and tumble ratio as claimed in claim 3, wherein: In step S2, when the air passage of the internal combustion engine is currently unobstructed, instruct the internal combustion engine to enter the normal operation stage, and periodically collect the valve lift data of the valve mechanism and the crankshaft angle data of the crankshaft mechanism, and the specific method includes: When the air passage of the internal combustion engine is currently not unobstructed, instruct the internal combustion engine to stop working. When the air passage of the internal combustion engine is currently unobstructed, instruct the internal combustion engine to switch from the preheating stage to the normal operation stage, and periodically collect the valve lift data and the crankshaft angle data through a valve motion amplitude sensor installed on the valve mechanism and a crankshaft rotation sensor installed on the crankshaft mechanism respectively.

5. The method for implementing an intake valve lift curve for improving the flow coefficient and tumble ratio as claimed in claim 4, wherein: In the step S2, generating the current valve lift curve of the valve mechanism according to the valve lift data and the crankshaft rotation angle data specifically includes: Taking the acquisition time of each data value in the valve lift data and the crankshaft rotation angle data as the association, constructing a one-to-one correspondence relationship of the data values for the valve lift data and the crankshaft rotation angle data, and then generating the current valve lift curve of the valve mechanism according to the one-to-one correspondence relationship of the data values.

6. The method for implementing an intake valve lift curve for improving the flow coefficient and tumble ratio according to claim 5, wherein: In the step S3, analyzing and processing the current valve lift curve to determine the difference information between the current valve lift curve and the desired valve lift curve specifically includes: Dividing the current valve lift curve and the expected valve lift curve into a small valve lift stage sub-curve and a medium-high valve lift stage sub-curve respectively according to the magnitude of the valve lift value; Determining the tumble ratio difference information between the small valve lift stage sub-curve of the current valve lift curve and the small valve lift stage sub-curve of the desired valve lift curve; Determining the flow coefficient difference information between the medium-high valve lift stage sub-curve of the current valve lift curve and the medium-high valve lift stage curve of the desired valve lift curve.

7. The method for implementing an intake valve lift curve for improving the flow coefficient and tumble ratio according to claim 6, wherein: In the step S3, judging whether the current overall working state of the internal combustion engine is normal according to the difference information specifically includes: If the tumble ratio difference information indicates that the tumble ratio of the small valve lift stage sub-curve of the current valve lift curve is less than the tumble ratio of the small valve lift stage sub-curve of the desired valve lift curve, it is judged that the current overall working state of the internal combustion engine is abnormal; Or, If the flow coefficient difference information indicates that the flow coefficient of the small valve lift stage sub-curve of the current valve lift curve is less than the flow coefficient of the small valve lift stage sub-curve of the desired valve lift curve, it is judged that the current overall working state of the internal combustion engine is abnormal.

8. The method for implementing an intake valve lift curve for improving the flow coefficient and tumble ratio according to claim 7, wherein: In the step S4, if the current overall working state of the internal combustion engine is abnormal, when the crankshaft mechanism is in different crankshaft rotation angle intervals, adjusting the valve lift value of the valve mechanism, so that the valve lift curve of the valve mechanism is transformed from a smooth connecting curve shape to a curve shape with a "convex" shape specifically includes: If the current overall operating state of the internal combustion engine is abnormal, when the crankshaft angle is in the range of [320°, 350°), the indicated valve lift is maintained at 2.7 mm; when the crankshaft angle is in the range of [350°, 510°), the indicated valve lift first linearly increases from 2.7 mm to 9.3 mm and then is maintained at 9.3 mm; when the crankshaft angle is in the range of [510°, 560°], the indicated valve lift decreases and is maintained at 2.7 mm, so that the valve lift curve of the valve mechanism is transformed from a smooth connected curve shape to a curve shape with a "convex" type.

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