Air inlet assembly of engine, engine, vehicle and air inlet control method of engine

Abstract

The invention discloses an air inlet assembly of an engine, the engine, a vehicle and an air inlet control method of the engine. The air inlet assembly is characterized in that a first air inlet valve is provided with a first air inlet lift profile; the second air inlet valve is provided with different second air inlet lift molded lines, namely the first molded line, the second molded line, the third molded line and the fourth molded line. The first molded line is the same as the first air inlet lift molded line; the valve lift and the valve opening duration of the second molded line are smaller than those of the first air inlet lift molded line; the valve lift of the third molded line is smaller than that of the first air inlet lift molded line; the valve lift and the valve opening duration of the fourth molded line are smaller than the valve lift and the valve opening duration of the first air inlet lift molded line. The second air inlet valve selects the corresponding second air inlet lift molded line to operate according to different requirements of the engine, so that asynchronous air inlet of the second air inlet valve and the first air inlet valve is achieved, different vortex effects are generated in a cylinder, and different in-cylinder air flowing requirements of the engine are met.

Description

Technical Field

[0001] The present invention relates to the technical field of engine air intake, and in particular to an engine air intake component, an engine, a vehicle and an engine air intake control method. Background Art

[0002] In order to alleviate the energy crisis and environmental pollution, reducing the gas consumption and emissions of the engine is an urgent problem to be solved for natural gas engines. Improving the thermal efficiency of natural gas engines is the only way to reduce gas consumption.

[0003] Traditional natural gas engines mostly use premixed ignition, where premixed ignition means that the fuel and oxygen (or air) are premixed into a uniform mixture. The premixed ignition method has a high combustion temperature in the cylinder, and the unburned area is easily affected by the high temperature in the cylinder to cause spontaneous combustion, thereby causing engine knock. The use of a strong tumble combustion system is an effective means for natural gas engines to suppress knock and improve engine thermal efficiency.

[0004] However, in the context of large cylinder diameter, it is difficult to generate circumferential vortex motion in the cylinder after strong tumble flow is constructed using parallel air passages. As a result, the tumble effect of the gas in the cylinder gradually weakens during the combustion process, resulting in a long late combustion period and incomplete combustion, leading to problems with exhaust temperature, emissions and gas consumption.

[0005] Therefore, how to provide an intake assembly for an engine to change the intake effect according to the engine operating conditions, so that the engine generates vortexes and improves the combustion efficiency of the engine is a technical problem that needs to be urgently solved by technical personnel in this field. Summary of the invention

[0006] In view of this, the present invention provides an intake assembly of an engine, which can change the intake effect according to the engine working condition, so that the engine generates vortex and improves the combustion efficiency of the engine. In addition, the present invention also provides an engine and a vehicle having the intake assembly of the engine, and an intake control method of the engine.

[0007] To achieve the above object, the present invention provides the following technical solutions:

[0008] An air intake assembly of an engine, comprising:

[0009] a first intake valve, the first intake valve having a first intake lift profile;

[0010] A second intake valve, the second intake valve has a different second intake lift profile, wherein the different intake lift profiles are respectively: a first profile, the first profile is the same as the first intake lift profile; a second profile, the rotation angle of the crankshaft when the valve is at its maximum opening of the second profile is smaller than the rotation angle of the crankshaft when the valve is at its maximum opening of the first intake lift profile, and the valve lift and the duration of valve opening of the second profile are respectively smaller than the valve lift and the duration of valve opening of the first intake lift profile; a third profile, the valve lift of the third profile is smaller than the valve lift of the first intake lift profile; a fourth profile, the rotation angle of the crankshaft when the valve is at its maximum opening of the fourth profile is greater than the rotation angle of the crankshaft when the valve is at its maximum opening of the first intake lift profile, and the valve lift and the duration of valve opening of the fourth profile are respectively smaller than the valve lift and the duration of valve opening of the first intake lift profile.

[0011] Preferably, in the above-mentioned intake assembly, the first intake lift profile and the third profile are both early-opening and late-closing profiles.

[0012] Preferably, in the above-mentioned air intake assembly, the second profile is an early-opening and early-closing profile.

[0013] Preferably, in the above-mentioned air intake assembly, the fourth profile is a late-opening and late-closing profile.

[0014] Preferably, in the above-mentioned intake assembly, the valve lift of the second profile, the valve lift of the third profile and the valve lift of the fourth profile are the same.

[0015] An engine comprises an air intake assembly, wherein the air intake assembly is any of the air intake assemblies described above.

[0016] Preferably, in the above engine,

[0017] The engine is in a first operating state, the first intake valve of the engine operates with a first intake lift profile, and the second intake valve operates with a first profile;

[0018] The engine is in a second operating state, the first intake valve of the engine operates with a first intake lift profile, and the second intake valve operates with a second profile;

[0019] The engine is in a third operating state, the first intake valve of the engine operates with a first intake lift profile, and the second intake valve operates with a third profile;

[0020] The engine is in the fourth operating state, the first intake valve of the engine operates with the first intake lift profile, and the second intake valve operates with the fourth profile.

[0021] Preferably, in the above-mentioned engine, the torque of the engine in the first working condition and the torque of the engine in the third working condition are both greater than the torque of the engine in the second working condition;

[0022] and the torque of the engine in the second operating condition is greater than the torque of the engine in the fourth operating condition;

[0023] The speed of the engine in the first operating condition is greater than the speed of the engine in the third operating condition.

[0024] A vehicle comprises an engine, wherein the engine is any one of the engines described above.

[0025] An engine intake control method, applied to any of the above engines, comprising:

[0026] The operating conditions of the engine are defined as follows: when the engine speed is greater than a and the torque is greater than b, the engine is in the first operating condition; when the engine torque is greater than c and not greater than b, the engine is in the second operating condition; when the engine speed is not greater than a and the torque is greater than b, the engine is in the third operating condition; when the engine torque is not greater than c and greater than zero, the engine is in the fourth operating condition, where b is greater than c;

[0027] Obtain the engine speed and torque, and determine the engine operating conditions;

[0028] According to the operating condition of the engine, the second intake valve of the engine switches to operate the profile, and the first profile, the second profile, the third profile and the fourth profile are all the profiles of the second intake valve.

[0029] An embodiment of the present invention discloses an intake assembly of an engine, wherein a second intake valve has a different second intake lift profile, and the second intake valve selects a corresponding second intake lift profile to operate when the engine has different requirements, so that the second intake valve and the first intake valve can achieve asynchronous intake and produce different gas flow effects in the cylinder to meet different in-cylinder gas flow requirements of the engine. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0031] Figure 1 It is a schematic structural diagram of an air intake assembly of an engine disclosed in an embodiment of the present invention;

[0032] Figure 2An intake lift profile of an intake valve of an intake assembly disclosed in an embodiment of the present invention;

[0033] Figure 3 A universal working condition division diagram of the engine disclosed in the embodiment of the present invention;

[0034] Figure 4 The figure is a flow chart of an intake control method of an engine disclosed in an embodiment of the present invention. DETAILED DESCRIPTION

[0035] The invention discloses an air intake assembly of an engine, which can change the air intake effect according to the engine working condition, so that the engine generates vortex and improves the combustion efficiency of the engine. In addition, the invention also discloses an engine and a vehicle having the air intake assembly of the engine, and an air intake control method of the engine.

[0036] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0037] In the following, the terms "first" and "second" are used for descriptive purposes only and are not to be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features.

[0038] In order to alleviate the energy crisis and environmental pollution, reducing the gas consumption and emissions of the engine is an urgent problem to be solved for natural gas engines. Improving the thermal efficiency of natural gas engines is the only way to reduce gas consumption.

[0039] Traditional natural gas engines mostly use premixed ignition, where premixed ignition means that the fuel and oxygen (or air) are premixed into a uniform mixture. The premixed ignition method has a high combustion temperature in the cylinder, and the unburned area is easily affected by the high temperature in the cylinder to cause spontaneous combustion, thereby causing engine knock. The use of a strong tumble combustion system is an effective means for natural gas engines to suppress knock and improve engine thermal efficiency.

[0040] However, in the context of large cylinder diameter, it is difficult to generate circumferential vortex motion in the cylinder after strong tumble flow is constructed using parallel air passages. As a result, during the combustion process in the cylinder, the tumble effect of the gas in the cylinder gradually weakens. Due to the low turbulent kinetic energy of the circumferential edge of the cylinder, the flame development speed in the later stage slows down, resulting in a long late combustion period and incomplete combustion, which leads to problems with exhaust temperature, emissions and gas consumption.

[0041] In addition, different operating conditions of natural gas engines have different requirements for in-cylinder gas flow. Traditional intake forms are difficult to take into account all engine operating conditions and it is difficult to reasonably match in-cylinder gas flow with actual needs.

[0042] It should be noted that tumble and swirl are two different forms of airflow movement. Swirl is an organized airflow movement around the cylinder axis generated during the engine intake process, which is divided into intake swirl, compression swirl and combustion swirl; while tumble is a specific flow pattern formed by airflow in the cylinder, which is mainly achieved through the design of the intake duct and combustion chamber.

[0043] Based on the above technical problems, the embodiment of the present application discloses an intake assembly of an engine, such as Figure 1 As shown, the intake assembly of the engine includes a first intake valve 10 , a second intake valve 20 , a cylinder head 30 and a piston 40 .

[0044] The first intake valve 10 and the second intake valve 20 are both connected to the cylinder head 30 , and a combustion chamber 5 is formed between the cylinder head 30 and the piston 40 . The first intake valve 10 and the second intake valve 20 can be connected to and disconnected from the combustion chamber 5 .

[0045] The first intake valve 10 includes a first intake doorway 11 and a first intake valve stem 12 , and the second intake valve 20 includes a second intake doorway 21 and a second intake valve stem 22 .

[0046] The first intake valve 11 and the second intake valve 21 are both connected to the combustion chamber 5. The first intake valve stem 12 is installed in the first intake valve 11 and controls the opening of the first intake valve 11. The second intake valve stem 22 is installed in the second intake valve 21 and controls the opening of the second intake valve 21.

[0047] The piston 40 can move in the height direction relative to the cylinder head 30, so as to realize different strokes of the engine, wherein the piston 40 has an intake stroke of the engine when it moves away from the cylinder head 30 in the height direction as the crankshaft rotates, and the engine can realize intake of air into the combustion chamber 5 through the first intake valve 10 and the second intake valve 20 during the intake stroke. It can be understood that the first intake valve 11 and the second intake valve 21 of the engine are in an open state during the intake stroke.

[0048] In the engine of the embodiment of the present application, the first intake valve 10 has the same opening degree and time for the first intake valve stem 12 to open the first intake valve path 11 during the intake stroke. In the natural gas engine, the second intake valve 20 has different opening degrees and time for the second intake valve stem 22 to open the second intake valve path 21 during the intake stroke. It can be understood that the second intake valve 20 has different opening angles, opening times and opening sizes to meet the requirements for vortex in different working conditions of the natural gas engine, thereby improving the combustion efficiency of the engine.

[0049] like Figure 2 As shown, the first intake valve 10 has a first intake lift profile, represented by a black line in the figure.

[0050] The second intake valve 20 has a different second intake lift profile, wherein the intake lift profile is divided into: a first profile (black in the figure), a second profile (red in the figure), a third profile (blue in the figure) and a fourth profile (green in the figure), and the valve opening angles and closing angles corresponding to the four profiles are different.

[0051] The first profile is the same as the first intake lift profile. Exemplarily, the crankshaft rotation angle range of the opening state of the first profile valve is 0° to 20°.

[0052] The rotation angle of the crankshaft when the valve of the second profile is at its maximum opening is less than the rotation angle of the crankshaft when the valve of the first intake lift profile is at its maximum opening. The valve lift of the second profile is less than the valve lift of the first intake lift profile. The duration of the valve opening of the second profile is less than the duration of the valve opening of the first intake lift profile. Exemplarily, the crankshaft rotation angle range of the opening state of the valve of the second profile is 1° to 14°.

[0053] The valve lift of the third profile is smaller than the valve lift of the first intake lift profile. Exemplarily, the crankshaft rotation angle range of the valve opening state of the third profile is 0° to 20°.

[0054] The rotation angle of the crankshaft when the valve of the fourth profile is at its maximum opening is greater than the rotation angle of the crankshaft when the valve of the first intake lift profile is at its maximum opening. The valve lift of the fourth profile is less than the valve lift of the first intake lift profile. The duration of the valve opening of the fourth profile is less than the duration of the valve opening of the first intake lift profile. Exemplarily, the crankshaft rotation angle range of the valve opening state of the third profile is 7° to 20°.

[0055] The second intake valve in the intake assembly of the engine of the embodiment of the present application has a different second intake lift profile, and the second intake valve selects the corresponding second intake lift profile to operate when different requirements are met, so that the second intake valve and the first intake valve can achieve asynchronous intake and produce different gas flow effects in the cylinder to meet the different in-cylinder gas flow requirements of the engine.

[0056] In addition, since strong tumble and weak vortex are generated in the cylinder, the speed in the later stage of combustion can be increased, knock can be suppressed, exhaust temperature can be reduced, and engine economy and reliability can be improved.

[0057] Figure 2It is shown in the figure that the crankshaft rotation angle corresponding to the piston top dead center is about 3°, and the crankshaft rotation angle corresponding to the piston bottom dead center is about 18°. Combining the crankshaft rotation angle range of the valve opening state of the first profile, the second profile, the third profile and the fourth profile, it can be known that the first profile is an early opening and late closing profile, the second profile is an early opening and early closing profile, the third profile is an early opening and late closing profile, and the fourth profile is a late opening and late closing profile.

[0058] Among them, the early opening of the embodiment of the present application refers to the early opening of the intake valve before the engine piston reaches the top dead center, so that the negative pressure generated by the downward movement of the piston can be used during the intake process to make the intake smoother, reduce the intake resistance, and increase the intake volume. Late closing refers to the delayed closing of the intake valve after the piston reaches the bottom dead center, making full use of the inertia of the intake airflow to continue to inflate the cylinder, thereby improving the intake efficiency. Combining the effects of early opening and late closing, it can be seen that the second intake valve adopts the intake method of the first profile, and the first intake valve adopts the early opening and late closing intake method, which can meet the engine's smooth intake and intake volume requirements. It should be noted that the early opening and late closing intake method can extend the intake time.

[0059] The early closing of the early opening and early closing of the embodiment of the present application means that the intake valve is closed before the engine piston reaches the bottom dead center. The second intake valve adopts the early opening and early closing intake mode of the second profile, and the first intake valve adopts the early opening and late closing intake mode, so that the intake process of the first intake valve and the second intake valve is different, which can meet the demand for small fuel demand in the later stage of the engine.

[0060] The second intake valve of the embodiment of the present application adopts the early opening and late closing intake method of the third profile, and the first intake valve adopts the early opening and late closing intake method, which can meet the engine's requirements for smooth intake and intake volume, thereby achieving the purpose of suppressing engine knock.

[0061] The late opening and late closing of the embodiment of the present application means that the intake valve opens after the engine piston reaches the top dead center. The second intake valve adopts the late opening and late closing intake mode, and the first intake valve adopts the early opening and late closing intake mode, which can meet the engine's needs to increase the combustion speed and reduce the amount of reflux in the cylinder at the initial stage of intake.

[0062] In some embodiments, the valve lift of the second profile, the valve lift of the third profile, and the valve lift of the fourth profile are the same.

[0063] It should be noted that the valve lift of the second profile, the valve lift of the third profile, the valve lift of the fourth profile, and the valve lift of the first profile can be set according to different needs and are all within the protection range.

[0064] Illustratively, an intake lift profile of the first intake valve 10 can be realized by the convex shape of the cam that is transmission-connected to the first intake valve; the first profile, second profile, third profile and fourth profile of the second intake valve 20 can be realized by convexities at different positions on the cam that is transmission-connected to the second intake valve, and the second intake valve 20 can execute the corresponding second intake lift profile by switching the different convex positions on the cam for transmission.

[0065] In addition, an embodiment of the present application also discloses an engine, including an intake assembly, wherein the intake assembly is the intake assembly disclosed in the above embodiment. Therefore, the engine having the intake assembly also has all the above technical effects, which will not be repeated here.

[0066] In the engine of the embodiment of the present application, under different working conditions, the second intake valve can be switched to the corresponding second intake lift profile according to the working condition requirements. Exemplarily, when the engine is in the first working condition, the first intake valve of the engine operates with the first intake lift profile, and the second intake valve operates with the first profile; when the engine is in the second working condition, the first intake valve of the engine operates with the first intake lift profile, and the second intake valve operates with the second profile; when the engine is in the third working condition, the first intake valve of the engine operates with the first intake lift profile, and the second intake valve operates with the third profile; when the engine is in the fourth working condition, the first intake valve of the engine operates with the first intake lift profile, and the second intake valve operates with the fourth profile.

[0067] The shapes of the first intake lift line, the first line, the second line, the third line and the fourth line can be found in Figure 2 The description in will not be repeated here.

[0068] It should be noted that the first working condition in this paper is Figure 3 Medium-high speed and high load conditions, the second condition is Figure 3 The third load condition is Figure 3 Medium and low speed high load conditions, the fourth condition is a low load condition.

[0069] Among them, the torque of the engine in the first operating condition and the torque of the engine in the third operating condition are both greater than the torque of the engine in the second operating condition; and the torque of the engine in the second operating condition is greater than the torque of the engine in the fourth operating condition; the speed of the engine in the first operating condition is greater than the speed of the engine in the third operating condition.

[0070] The dividing speed between high speed and low speed of the engine is defined as a, the dividing torque between high load torque and medium load torque is defined as b, and the dividing torque between medium load torque and low load torque is defined as c. The specific values ​​of a, b, and c are determined based on performance calibration.

[0071] For example, the current engine speed is 600r / min-1900r / min, the value range of a is 1300r / min-1400r / min. The value range of b is about 75% of the rated torque of the engine, and the value range of c is about 25% of the rated torque of the engine. For other contents of this article, please refer to this data relationship.

[0072] When the engine is under high-speed and high-load conditions, the engine intake volume is large and the flow in the cylinder is strong. At this time, the engine thermal efficiency is mainly affected by the smoothness of the intake. Based on this, the engine of the embodiment of the present application needs to ensure that the first intake valve and the second intake valve have sufficient intake time under high-speed and high-load conditions to ensure smooth engine intake. Therefore, the second intake valve operates with the first profile. It can be understood that when the engine is under high-speed and high-load conditions, the second intake valve operates with the first profile and the first intake valve operates with the first intake lift profile to ensure that the first intake valve and the second intake valve have sufficient intake time and can both smoothly intake air, thereby ensuring the stable operation of the engine. Exemplarily, the intake rates of the first intake valve and the second intake valve are the same, so that the cylinders of the engine are symmetrically intake.

[0073] When the engine is under intermediate load conditions, the engine intake volume is small and the flow in the cylinder is weak. At this time, the late combustion speed in the cylinder is slow, which can easily cause problems such as long afterburning time, low engine thermal efficiency, and high emissions and gas consumption. Based on this, the engine of the embodiment of the present application needs to increase the difference between the first intake valve lift and the second intake valve lift to improve the swirl ratio under intermediate load conditions, and needs to reduce the late intake volume in the engine cylinder. Therefore, the second intake valve and the second new type are operated. It can be understood that: when the engine is under intermediate load conditions, the second intake valve operates with the second profile, and the first intake valve operates with the first intake lift profile, which can reduce the late intake volume in the engine cylinder and avoid long late combustion time; it can also improve the swirl ratio, and can solve the problems of low thermal efficiency and long emission time.

[0074] When the engine is under low-speed and high-load conditions, the engine intake volume is moderate, but due to the high temperature in the cylinder in this area, knock is prone to occur. In addition to being affected by the smoothness of the intake, the engine thermal efficiency also depends on the impact of the combustion speed in the cylinder on the knock. Based on this, the engine of the embodiment of the present application needs to ensure sufficient intake time under low-speed and high-load conditions, and increase the difference between the first intake valve lift and the second intake valve lift to increase the swirl ratio, so as to achieve the purpose of accelerating the fuel combustion speed and suppressing knock. It can be understood that when the engine is under low-speed and high-load conditions, the second intake valve runs on the third profile, and the first intake valve runs on the first intake lift profile, so that the engine has sufficient intake time, and there is a difference between the first intake valve lift and the second intake valve lift to increase the swirl ratio, so as to achieve the purpose of suppressing knock.

[0075] When the engine is under low load conditions, the engine intake volume is small, the flow in the cylinder is weak, and at the same time, due to the small throttle opening, there is a negative intake pressure. There is a backflow at the initial opening of the intake valve, which causes the exhaust gas in the cylinder to flow back to the intake pipe, further deteriorating the combustion speed. Based on this, the engine of the embodiment of the present application needs to construct a vortex by delaying the opening angle of the second intake valve under low load conditions, so as to achieve the purpose of increasing the combustion speed and reducing the amount of backflow in the cylinder at the initial intake stage. It can be understood that: when the engine is under low load conditions, the second intake valve operates with the fourth profile, and the first intake valve operates with the first intake lift profile, delaying the angle when the second intake valve is opened, so as to generate a vortex when the second intake valve is opened, thereby achieving the purpose of increasing the combustion speed and reducing the amount of backflow in the cylinder at the initial intake stage.

[0076] Combined with the above analysis, it can be seen that the engine of the embodiment of the present application, under different working conditions, selects different second intake lift profiles through the second intake valve, so that the first intake valve and the second intake valve intake differentially, so that the first intake valve and the second intake valve have differentiated intake positions, so that a vortex is formed in the engine, thereby improving the combustion efficiency of the engine. In addition, the above method does not affect the effect of the engine tumble flow, and avoids the problem of reduced tumble flow intensity caused by using changes in the airway structure to generate vortices.

[0077] It should be noted that the engine in some embodiments is a natural gas engine.

[0078] In addition, the present application protects a vehicle including an engine, and the engine is the engine disclosed in the above-mentioned embodiment, therefore, the vehicle having the engine also has all the above-mentioned technical effects.

[0079] like Figure 4 As shown, the embodiment of the present application also discloses an intake control method of an engine, comprising the following steps: It should be noted that, Figure 4 The No. 2 intake valve in the figure is the second intake valve in this article.

[0080] S1: Define the engine operating conditions.

[0081] During the operation of the engine, according to the engine speed and torque request, the boundary speed between high speed and low speed of the engine is defined as a, the boundary torque between high load torque and medium load torque is b, and the boundary torque between medium load torque and low load torque is c. The specific values ​​of a, b, and c are determined based on performance calibration.

[0082] Among them, when the engine speed is greater than a and the torque is greater than b, the engine is in a high-speed and high-load condition, which is also referred to as the first condition in this article; when the engine speed is not greater than a and the torque is greater than b, the engine is in a low-speed and high-load condition, which is also referred to as the third condition in this article; when the engine torque is not greater than b and greater than c, the engine is in an intermediate load condition, which is also referred to as the second condition in this article; when the engine torque is not greater than c but greater than zero, the engine is in a low-load condition, which is also referred to as the fourth condition in this article.

[0083] S2: Pre-store engine operating condition information.

[0084] The speed and torque information corresponding to the engine's medium-high speed and high load conditions, low-speed and high load conditions, intermediate load conditions and low load conditions are pre-stored in the engine's control system.

[0085] S3: Obtain engine operation information.

[0086] After detecting that the engine is started, the speed and torque of the engine are obtained during operation.

[0087] S4: Determine the operating condition of the engine, and switch the operating profile of the second intake valve of the engine.

[0088] If the torque during the operation of the engine is not greater than zero, the engine is in a reverse drag condition, and the second intake valve of the engine executes the first profile.

[0089] If the torque during the operation of the engine is greater than b, and the speed during the operation of the engine is greater than a, the engine is in the first operating condition, and the second intake valve of the engine executes the first profile.

[0090] If the torque during the operation of the engine is greater than b, and the speed during the operation of the engine is not greater than a, the engine is in the third operating condition, and the second intake valve of the engine executes the third profile.

[0091] If the torque during the operation of the engine is not greater than b and greater than c, the engine is in the second operating condition; wherein b is greater than c, and the second intake valve of the engine executes the second profile.

[0092] If the torque during the operation of the engine is not greater than c, the engine is in the fourth operating condition, and the second intake valve of the engine executes the fourth profile.

[0093] It should be noted that the first profile, the second profile, the third profile and the fourth profile are all second intake valve operation profiles, and their respective shapes can be seen in Figure 1 As described in the description, and the engine has a structure for realizing different second intake lift profiles for the second intake valve, the structure for realizing different second intake lift profiles for the second intake valve is not specifically limited herein.

[0094] When the engine is operating at high speed and high load, the second intake valve operates on the first profile and the first intake valve operates on the first intake lift profile to ensure that the first intake valve and the second intake valve have sufficient intake time and can both intake air smoothly, thereby ensuring stable operation of the engine.

[0095] When the engine is under medium load conditions, the second intake valve operates on the second profile and the first intake valve operates on the first intake lift profile, which can reduce the intake volume in the engine cylinder in the later stage and avoid long combustion time in the later stage; it can also improve the swirl ratio and solve the problems of low thermal efficiency and long emission time.

[0096] When the engine is operating at low speed and high load, the second intake valve operates on the third profile and the first intake valve operates on the first intake lift profile, so that the engine has sufficient intake time, and there is a difference between the first intake valve lift and the second intake valve lift to increase the swirl ratio, thereby achieving the purpose of suppressing knock.

[0097] When the engine is in low load condition, the second intake valve operates on the fourth profile and the first intake valve operates on the first intake lift profile, delaying the opening angle of the second intake valve, thereby generating vortex when the second intake valve opens, thereby achieving the purpose of increasing the combustion speed and reducing the amount of reflux in the cylinder at the initial stage of intake.

[0098] Combined with the above analysis, it can be seen that the engine of the embodiment of the present application, under different working conditions, selects different second intake lift profiles through the second intake valve, so that the first intake valve and the second intake valve intake differentially, so that the first intake valve and the second intake valve have differentiated intake positions, so that a vortex is formed in the engine, thereby improving the combustion efficiency of the engine. In addition, the above method does not affect the effect of the engine tumble flow, and avoids the problem of reduced tumble flow intensity caused by using changes in the airway structure to generate vortices.

[0099] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0100] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An air intake assembly of an engine, characterized in that: include: a first intake valve, the first intake valve having a first intake lift profile; A second intake valve, the second intake valve has a different second intake lift profile, wherein the different intake lift profiles are respectively: a first profile, the first profile is the same as the first intake lift profile; a second profile, the rotation angle of the crankshaft when the valve is at its maximum opening of the second profile is smaller than the rotation angle of the crankshaft when the valve is at its maximum opening of the first intake lift profile, and the valve lift and the duration of valve opening of the second profile are respectively smaller than the valve lift and the duration of valve opening of the first intake lift profile; a third profile, the valve lift of the third profile is smaller than the valve lift of the first intake lift profile; a fourth profile, the rotation angle of the crankshaft when the valve is at its maximum opening of the fourth profile is greater than the rotation angle of the crankshaft when the valve is at its maximum opening of the first intake lift profile, and the valve lift and the duration of valve opening of the fourth profile are respectively smaller than the valve lift and the duration of valve opening of the first intake lift profile.

2. The air intake assembly according to claim 1, characterized in that: The first intake lift profile and the third profile are both early-opening and late-closing profiles.

3. The air intake assembly according to claim 2, characterized in that: The second profile is an early opening and early closing profile.

4. The air intake assembly according to claim 3, characterized in that: The fourth profile is a late opening and late closing profile.

5. The air intake assembly according to any one of claims 1 to 4, characterized in that: The valve lift of the second profile, the valve lift of the third profile, and the valve lift of the fourth profile are the same.

6. An engine, comprising an air intake assembly, characterized in that: The air intake assembly is the air intake assembly according to any one of claims 1 to 5.

7. The engine according to claim 6, characterized in that The engine is in a first operating state, the first intake valve of the engine operates with a first intake lift profile, and the second intake valve operates with a first profile; The engine is in a second operating state, the first intake valve of the engine operates with a first intake lift profile, and the second intake valve operates with a second profile; The engine is in a third operating state, the first intake valve of the engine operates with a first intake lift profile, and the second intake valve operates with a third profile; The engine is in the fourth operating state, the first intake valve of the engine operates with the first intake lift profile, and the second intake valve operates with the fourth profile.

8. The engine according to claim 7, characterized in that The torque of the engine in the first working condition and the torque of the engine in the third working condition are both greater than the torque of the engine in the second working condition; and the torque of the engine in the second operating condition is greater than the torque of the engine in the fourth operating condition; The speed of the engine in the first operating condition is greater than the speed of the engine in the third operating condition.

9. A vehicle comprising an engine, characterized in that: The engine is the engine according to any one of claims 6 to 8.

10. An intake control method for an engine, applied to the engine according to any one of claims 6 to 8, characterized in that: include: Define the operating conditions of the engine: when the engine speed is greater than a and the torque is greater than b, the engine is in the first operating condition; When the torque of the engine is greater than c and not greater than b, the engine is in the second operating condition; When the engine speed is not greater than a and the torque is greater than b, the engine is in the third operating condition; When the torque of the engine is not greater than c and greater than zero, the engine is in the fourth operating condition, wherein b is greater than c; Obtain the engine speed and torque, and determine the engine operating conditions; According to the operating condition of the engine, the second intake valve of the engine switches to operate the profile, and the first profile, the second profile, the third profile and the fourth profile are all the profiles of the second intake valve.

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