A Miller cycle high tumble intake port and design method

Abstract

The present invention discloses a Miller cycle high-tumble intake port, including: an intake port, at the lower end of which there is an airway connecting pipe, and an included angle is formed between the airway connecting pipe and the intake port; a combustion chamber roof plate, which is connected to the airway connecting pipe; a shielding member is arranged between the combustion chamber roof plate and the airway connecting pipe. By changing three parameters, namely the shielding height h, the shielding angle range A, and the valve shielding clearance d, the present invention guides most of the air flow to flow along the central side of the combustion chamber to form a positive tumble, improves the tumble ratio of the intake port at medium and low valve lifts, improves the in-cylinder air flow intensity of the supercharged Miller cycle engine, improves the air-fuel mixing, maintains a large flow coefficient while increasing the tumble ratio, and reduces the pumping loss.

Description

Technical Field

[0001] The present invention relates to the technical field of engine intake ports, and particularly relates to a Miller cycle high-tumble intake port and a design method thereof. Background Art

[0002] The engine intake port is one of the most important components that determine the combustion and performance of an internal combustion engine. Two important performance parameters of the intake port: the flow coefficient and the tumble ratio, affect the size of the cyclic intake air volume of the engine, the quality of the fuel-air mixture in the cylinder, and the combustion diffusion speed, and ultimately affect the performance and fuel economy of the engine. The traditional intake port design method mainly designs and adjusts three main parameters, namely, the intake port angle α, the intake port throat diameter, and the intake valve angle, to design the intake port. The existing technology has the following deficiencies:

[0003] For a Miller cycle supercharged engine, the maximum lift and included angle of the intake valve profile will be smaller than those designed for an Otto cycle engine, and the intake impulse and the quality of the fuel-air mixture will be very poor, resulting in pre-ignition and knocking problems under low-speed high-load conditions. The existing intake port design method can only increase the tumble ratio at a relatively high valve lift and cannot effectively increase the tumble ratio at medium and low valve lifts. The existing intake port design method will greatly sacrifice the flow coefficient of the intake port while increasing the tumble ratio of the air passage, affecting the power performance of the engine. Summary of the Invention

[0004] The purpose of this part is to outline some aspects of the embodiments of the present invention and briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this part, as well as in the abstract and title of the present application, to avoid obscuring the purpose of this part, the abstract, and the title, and such simplifications or omissions shall not be used to limit the scope of the present invention.

[0005] In view of the problems existing in the above-mentioned existing Miller cycle high-tumble intake ports, the present invention is proposed.

[0006] Therefore, the purpose of the present invention is to provide a Miller cycle high-tumble intake port and a design method thereof.

[0007] To solve the above technical problems, the present invention provides the following technical solution: A Miller cycle high-tumble intake port includes an intake port, a gas passage connecting pipe is provided at the lower end of the intake port, and an included angle is formed between the gas passage connecting pipe and the intake port, and; a combustion chamber top plate, the combustion chamber top plate is connected to the gas passage connecting pipe; a shielding member is provided between the combustion chamber top plate and the gas passage connecting pipe.

[0008] As a preferred embodiment of the Miller cycle high-tumble intake port of the present invention, wherein: the height of the shielding member is 0.2 - 4.0 mm, and the radial clearance between the shielding member and the valve mechanism is 0.6 - 2.0 mm.

[0009] As a preferred embodiment of the Miller cycle high-tumble intake port of the present invention, wherein: the shielding member includes an upper baffle provided at the end of the airway connecting pipe, a lower baffle connected to the upper baffle, and a connecting member provided between the upper baffle and the lower baffle. The connecting member includes a threaded rod provided on the lower baffle and a threaded hole provided on the upper baffle for cooperating with the threaded rod.

[0010] As a preferred embodiment of the Miller cycle high-tumble intake port of the present invention, wherein: a first card slot is provided on the lower baffle, a second card slot is provided on the upper baffle, a locking belt is provided between the first card slot and the second card slot, and an inlet is provided at the first card slot and the second card slot.

[0011] As a preferred embodiment of the Miller cycle high-tumble intake port of the present invention, wherein: one end of the locking belt is provided with a locking block, a locking cavity is provided in the locking block, a plug is provided on the other side of the locking belt, the locking belt includes a plurality of component blocks hinged in sequence at the ends, a winding column is provided in the locking cavity, a guide rail is provided on the inner bottom surface of the locking cavity, the inner diameter of the guide rail gradually increases from inside to outside, and a protrusion is provided on the outer side of each component block.

[0012] As a preferred embodiment of the Miller cycle high-tumble intake port of the present invention, wherein: an outlet groove is provided on the locking block, and an insertion groove is provided at one end of the locking block away from the outlet groove.

[0013] The present invention also discloses a design method for a Miller cycle high-tumble intake port, including the following steps:

[0014] According to the performance requirements of the engine, confirm the target values of the flow coefficient and tumble ratio parameters of the intake port;

[0015] Pre-select a set of shielding member parameter combinations for shielding member design;

[0016] Perform numerical simulation analysis on the intake port model to calculate the flow coefficient and tumble ratio parameters at each lift; and,

[0017] Compare the flow coefficient and tumble ratio parameters to select the target airway parameters.

[0018] As a preferred embodiment of the Miller cycle high-tumble intake port and design method of the present invention, wherein: the average flow coefficient of the intake port needs to be not less than 0.25, and in order to cooperate with efficient combustion, the average tumble ratio of the intake port needs to be higher than 2.5.

[0019] As a preferred embodiment of the Miller cycle high-tumble intake port and design method of the present invention, wherein: the shielding height is set to 0 - 4 mm, the shielding angle range is 60 - 180°, and the valve shielding clearance range is 0.6 - 2.0 mm.

[0020] As a preferred embodiment of the design method of the Miller cycle high tumble intake port of the present invention, where: if the flow coefficient meets the target, but the tumble ratio is less than the target, then within the parameter range, continue to reduce the d parameter or increase the h / A parameters. After determining a version of the intake port model scheme, repeat the above steps until both the flow coefficient and the tumble ratio meet the design targets;

[0021] If the tumble ratio parameter meets the design target, but the flow coefficient is less than the target value, then within the parameter range, correspondingly increase the d parameter or reduce the h / A parameters. After determining a version of the intake port model scheme, repeat the above steps until both the flow coefficient and the tumble ratio meet the design targets.

[0022] Advantages of the present invention: By changing three parameters, namely the shielding height h, the shielding angle range A, and the valve shielding clearance d, the present invention guides most of the air flow to flow along the center side of the combustion chamber, forming a positive tumble, improving the tumble ratio of the intake port at medium and low valve lifts, improving the in-cylinder air flow intensity of the supercharged Miller cycle engine, improving the air-fuel mixing, maintaining a large flow coefficient while increasing the tumble ratio, and reducing the pumping loss. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings. Among them:

[0024] Figure 1 It is a schematic diagram of the overall structure of the Miller cycle high tumble intake port of the present invention.

[0025] Figure 2 It is a schematic cross-sectional view of the internal structure of the Miller cycle high tumble intake port of the present invention.

[0026] Figure 3 It is a schematic diagram of the shielding member structure in Embodiment 2 of the Miller cycle high tumble intake port of the present invention.

[0027] Figure 4 It is a schematic diagram of the locking block structure of the Miller cycle high tumble intake port of the present invention.

[0028] Figure 5 It is an exploded schematic diagram of the shielding member structure of the Miller cycle high tumble intake port of the present invention.

[0029] Figure 6 It is a schematic diagram of the composition of the component blocks of the Miller cycle high tumble intake port of the present invention.

[0030] Figure 7 Schematic diagram for comparing tumble ratio parameters of the intake port of the Miller cycle high-tumble intake port of the present invention.

[0031] Figure 8 Schematic flow chart of the design method of the Miller cycle high-tumble intake port of the present invention. Specific embodiments

[0032] To make the above objects, features and advantages of the present invention more obvious and understandable, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings of the specification.

[0033] In the following description, many specific details are set forth in order to fully understand the present invention. However, the present invention can also be implemented in other ways different from those described herein. Those skilled in the art can make similar extensions without departing from the connotation of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed below.

[0034] Secondly, the so-called "one embodiment" or "embodiment" herein refers to a specific feature, structure or characteristic that can be included in at least one implementation manner of the present invention. The appearances of "in one embodiment" in different places in this specification do not all refer to the same embodiment, nor are they separate or alternative embodiments that exclude each other from other embodiments.

[0035] Thirdly, the present invention is described in detail with reference to the schematic diagrams. When describing the embodiments of the present invention in detail, for the convenience of explanation, the cross-sectional views showing the device structure will be enlarged locally in a non-general proportion, and the schematic diagrams are only examples and should not limit the scope of protection of the present invention here. In addition, in actual production, three-dimensional spatial dimensions including length, width and depth should be included.

[0036] Embodiment 1

[0037] Referring to Figure 1 and Figure 2 , the present invention discloses a Miller cycle high-tumble intake port 100, including an intake port 100. An airway connecting pipe 101 is provided at the lower end of the intake port 100. The lower end of the airway connecting pipe 101 bulges outwards to form a disk-like shape, and the upper end bulges upwards. At the same time, airway holes are provided at the upper end of the airway connecting pipe 101. Two airway holes are arranged in parallel. At the same time, the orientations of both airway holes are inclined outwards, and the angle formed between the opening surfaces of the two airway holes is 120°. At the same time, the included angle formed between the opening surface of each airway hole and the horizontal plane is an acute angle, so that an included angle is formed between the airway connecting pipe 101 and the intake port 100.

[0038] The lower end of the air passage connecting pipe 101 is directly connected to the combustion chamber top plate 102. The combustion chamber top plate 102 is connected and communicated with the air passage connecting pipe 101, so as to form a complete air passage path. A shielding member 103 is arranged between the combustion chamber top plate 102 and the air passage connecting pipe 101. In this embodiment, the shielding member is an annular shielding plate, which is arranged around between the air passage connecting pipe 101 and the combustion chamber top plate 102, and the height of the shielding member is 0.2 - 4.0 mm. In this embodiment, 3.0 mm is selected. The radial clearance between the shielding member 103 and the valve mechanism is 0.6 - 2.0 mm. In this embodiment, 0.6 mm is selected.

[0039] And its structural axis coincides with the axis of the intake valve. The main design parameters are three parameters: the shielding height h, the shielding angle range A, and the valve shielding clearance d. It guides most of the air flow to flow along the central side of the combustion chamber to form a positive tumble. And by using fluid analysis software to conduct numerical simulation analysis on the designed intake port 100 model, the flow coefficient and tumble ratio parameters at each lift are obtained. If the design requirements are met, the design is completed. Otherwise, the three parameters of the shielding masking structure h / A / d are readjusted until the air passage flow coefficient and tumble ratio parameters meet the design requirements.

[0040] The present invention guides most of the air flow to flow along the central side of the combustion chamber to form a positive tumble by changing the three parameters of the shielding height h, the shielding angle range A, and the valve shielding clearance d, improves the tumble ratio of the intake port 100 at medium and low valve lifts, improves the in-cylinder air flow intensity of the supercharged Miller cycle engine, improves the air-fuel mixing, maintains a large flow coefficient while increasing the tumble ratio, and reduces the pumping loss.

[0041] Embodiment 2

[0042] Refer to Figure 1-7 In this embodiment, different from the first embodiment, the shielding member 103 includes an upper baffle 103a connected to the air passage connecting pipe 101. The shape of the upper baffle 103a is an arc ring, and its overall size is the same as the size of the lower end of the air passage connecting pipe 101. A lower baffle 103b is arranged at the upper end of the combustion chamber top plate 102. The size of the lower baffle 103b is set the same as the size of the upper baffle 103a, and its shape is also an arc ring. When the air passage connecting pipe 101 and the combustion chamber top plate 102 are connected, the upper baffle 103a and the lower baffle 103b are in complete contact. A connecting member is arranged between the upper baffle 103a and the lower baffle 103b, and the connecting member can be used to connect or disassemble between the upper baffle 103a and the lower baffle 103b, which is convenient for the operator to install.

[0043] Further, in this embodiment, the connecting member includes a threaded rod disposed on the lower baffle 103b and a threaded hole disposed on the upper baffle 103a that cooperates with the threaded rod. When installing the lower baffle 103b, the operator only needs to align the lower baffle 103b with the upper baffle 103a, and then rotate the threaded rod so that the threaded rod is connected to the threaded hole, thereby completing the installation. After the installation is completed, there will be a gap between the upper baffle 103a and the lower baffle 103b.

[0044] To make up for the gap, a first card slot 200 is provided on the lower baffle 103b, and a second card slot 201 is provided on the upper baffle 103a. The shapes of the first card slot 200 and the second card slot 201 are both annular and are provided along the shapes of the upper baffle 103a and the lower baffle 103b. When the upper baffle 103a cooperates with the lower baffle, the two are exactly overlapped and butted. A locking band 202 is provided between the first card slot 200 and the second card slot 201. After the upper baffle 103a is butted with the lower baffle 103b, the locking band 202 is snapped into the first card slot 200 and the second card slot 201 to seal the gap, thereby enhancing the connection and shielding.

[0045] Further, an inlet 203 is provided at the first card slot 200 and the second card slot 201. A locking block 301 is provided at the inlet 203 of the first card slot 200. The shape of the locking block 301 is a rectangular block. A locking cavity 302 is provided in the locking block 301. A plug 303 is also provided on the other side of the locking band 202.

[0046] Among them, in this embodiment, the locking band 202 includes a plurality of component blocks 304 that are sequentially hinged at the ends. An ear plate is provided at the front end of the component block 304. There are two ear plates. A hanging plate also extends downward at the rear end of the component block 304. To achieve the interconnection between the component blocks 304, a mating plate is also provided at the rear end of each component block 304. A rotating shaft is connected between the mating plate and the ear plate; and the plug 303 is connected to the foremost component block 304. A protrusion 400 is provided on the outside of each component block 304.

[0047] Preferably, when the component blocks 304 extend outwards, a plurality of component blocks 304 are connected into a "band" shape. This setting increases the connection stability between the component blocks 304 after they extend outwards, and can cooperate with the upper baffle 103a and the lower baffle 103b to enhance the effectiveness of shielding.

[0048] Further, a winding column is arranged in the locking cavity 302. The winding column is vertically arranged with respect to the inner bottom surface of the locking block 301, and a coating layer is arranged on the winding column. At the same time, a lock is also arranged on the winding column. The last component block 304 is hinged to the side wall of the winding column, and a guide rail 306 is arranged on the inner bottom surface of the locking cavity 302. The inner diameter of the guide rail 306 gradually increases from the inside to the outside, showing an outward rotating and spreading shape, and several component blocks 304 are arranged in the guide rail 306. An outlet groove is formed on the locking block 301, and an insertion groove is arranged at one end of the locking block 301 away from the outlet groove.

[0049] Preferably, baffles extend outwards from both the upper and lower ends of each component block 304, and fitting grooves for cooperating with the baffles are formed in both the first card slot 200 and the second card slot 201.

[0050] The remaining structure is the same as that of Embodiment 1.

[0051] Operation process: When the operator installs the airway connecting plate, align the upper baffle 103a with the lower baffle 103b, and then the operator pulls the protrusions on the outside of the component block 304 to push several component blocks 304 outwards. After the component blocks 304 are pushed out, they will be clamped in the first card slot 200 and the second card slot 201, and after moving around in the first card slot 200 and the second card slot 201 for one week, the front plug 303 is inserted into the insertion groove, thereby forming an annular shielding range and achieving a shielding effect.

[0052] Embodiment 3

[0053] Referring to Figure 8 , the present invention discloses a design method for a Miller cycle high tumble intake port 100, including the following steps:

[0054] According to the performance requirements of the engine, confirm the target values of the flow coefficient and tumble ratio parameters of the intake port 100;

[0055] Pre-select a set of shielding component parameter combinations for shielding component design;

[0056] Conduct numerical simulation analysis on the intake port 100 model, and calculate the flow coefficient and tumble ratio parameters at each lift; compare the flow coefficient and tumble ratio parameters, and select the target airway parameters.

[0057] Design an arc shielding surface structure with an axis coinciding with the axis of the intake valve at the connection position between the valve seat sealing surface and the combustion chamber surface on the lower contour side of the intake passage 100. When the intake valve opens for intake, within the low valve lift, due to the shielding effect of the airway masking structure, when the air flow flows along the lower contour line of the intake passage 100 through the intake valve, it guides the air flow to flow towards the center side of the combustion chamber, forming a positive tumble; the main design parameters of the masking structure are three parameters: shielding height h, shielding angle range A, and valve shielding clearance d. The main process of this invention's design is as follows:

[0058] According to the high thermal efficiency performance requirements of the Miller cycle engine, the combustion system requires very high air flow motion to cooperate, and a high-tumble intake passage 100 needs to be designed;

[0059] According to the performance requirements of the engine, confirm the target values of the flow coefficient and tumble ratio parameters of the intake passage 100. To ensure the external characteristic power performance of the engine, the average flow coefficient of the intake passage 100 needs to be not less than 0.25. To cooperate with efficient combustion, the average tumble ratio of the intake passage 100 needs to be higher than 2.5;

[0060] Design an intake passage 100 with a valve shielding masking structure. Generally, set the shielding height to 0 - 4 mm, the shielding angle range to 60 - 180°, and the valve shielding clearance range to 0.6 - 2.0 mm; for the initial airway scheme, first pre-select a set of parameter combinations for the shielding structure design;

[0061] After the airway scheme digital model is completed, use fluid analysis software to conduct numerical simulation analysis on the designed intake passage 100 model, calculate the flow coefficient and tumble ratio parameters at each lift. If both the flow coefficient and tumble ratio parameters meet the design goals, the design scheme is the target scheme;

[0062] If the flow coefficient meets the target, but the tumble ratio is less than the target, then within the parameter range of this step, continue to reduce the d parameter or increase the h / A two parameters. After determining a version of the airway model scheme, repeat this step until both the flow coefficient and tumble ratio meet the design goals;

[0063] If the tumble ratio parameter meets the design goal, but the flow coefficient is less than the target value, then within the parameter range, correspondingly increase the d parameter or reduce the h / A two parameters. After determining a version of the airway model scheme, repeat this step until both the flow coefficient and tumble ratio meet the design goals.

[0064] The average flow coefficient of the intake port 100 needs to be not less than 0.25. To cooperate with efficient combustion, the average tumble ratio of the intake port 100 needs to be higher than 2.5. The masking height is set to 0 - 4 mm, the masking angle range is 60 - 180°, and the valve masking clearance range is 0.6 - 2.0 mm. If the flow coefficient meets the target, but the tumble ratio is less than the target, then within the parameter range, continue to reduce the d parameter or increase the h / A parameters. After determining a version of the intake port model scheme, repeat the above steps until both the flow coefficient and the tumble ratio meet the design goals;

[0065] If the tumble ratio parameter meets the design goal, but the flow coefficient is less than the target value, then within the parameter range, correspondingly increase the d parameter or reduce the h / A parameters. After determining a version of the intake port model scheme, repeat the above steps until both the flow coefficient and the tumble ratio meet the design goals.

[0066] The invention is applied to the design of the intake port 100 of a Miller cycle supercharged engine, solving the problem of the relatively small tumble ratio in traditional low and medium valve lifts, so as to meet the high tumble requirement of the Miller cycle engine, improve the combustion state of the engine, and enhance the performance of the engine. Specifically, it is manifested in the following aspects:

[0067] 1) While increasing the tumble ratio of low and medium valve lifts, maintaining a large flow coefficient;

[0068] 2) Improving the economy of the Miller cycle engine while maintaining high power performance;

[0069] 3) Greatly increasing the tumble ratio of the intake port 100, improving the air-fuel mixture, improving the combustion state, and reducing the combustion noise of the engine;

[0070] 4) Using fluid analysis software to conduct digital simulation calculations on the design scheme, which is simple and fast, with a short iterative design cycle, reducing the test verification cycle and development costs.

[0071] Importantly, it should be noted that the construction and arrangement of the present application shown in multiple different exemplary embodiments are merely illustrative. Although only a few embodiments are described in detail in this disclosure, those who refer to this disclosure should easily understand that many modifications are possible without materially departing from the novel teachings and advantages of the subject matter described in this application (e.g., changes in the dimensions, scales, structures, shapes and proportions of various elements, as well as parameter values (such as temperature, pressure, etc.), installation arrangements, use of materials, colors, orientations, etc.). For example, an element shown as integrally formed may be composed of multiple parts or elements, the position of the element may be inverted or otherwise changed, and the nature, number or position of discrete elements may be altered or changed. Accordingly, all such modifications are intended to be included within the scope of the present invention. The order or sequence of any process or method steps may be altered or reordered according to alternative embodiments. In the claims, any "means-plus-function" clause is intended to cover the structures that perform the recited function described herein, and not only structural equivalents but also equivalent structures. Other substitutions, modifications, changes and omissions may be made in the design, operating conditions and arrangement of the exemplary embodiments without departing from the scope of the present invention. Therefore, the present invention is not limited to a particular embodiment, but extends to various modifications that still fall within the scope of the appended claims.

[0072] In addition, in order to provide a concise description of the exemplary embodiments, not all features of the actual embodiments may be described (i.e., those features that are not relevant to the currently contemplated best mode of carrying out the present invention, or those features that are not relevant to the implementation of the present invention).

[0073] It should be understood that in the development of any actual implementation, as in any engineering or design project, numerous specific implementation decisions may be made. Such development efforts may be complex and time-consuming, but for those of ordinary skill in the art who benefit from this disclosure, the development efforts will be a routine task of design, fabrication and production without undue experimentation.

[0074] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the spirit and scope of the technical solutions of the present invention, and they should all be covered by the scope of the claims of the present invention.

Claims

1. A Miller cycle high tumble intake port, characterized in that: including, an intake passage (100) having an air passage connecting pipe (101) provided at its lower end, and an angle is formed between the air passage connecting pipe (101) and the intake passage (100), and; a combustion chamber top plate (102) connected to the air passage connecting pipe (101); a shielding member (103) is provided between the combustion chamber top plate (102) and the air passage connecting pipe (101); the shielding member (103) includes an upper baffle (103a) provided at the end of the air passage connecting pipe (101), a lower baffle (103b) connected to the upper baffle (103a), and a connecting member provided between the upper baffle (103a) and the lower baffle (103b), wherein the connecting member includes a threaded rod provided on the lower baffle (103b) and a threaded hole provided on the upper baffle (103a) for mating with the threaded rod; a first card slot (200) is formed on the lower baffle (103b), a second card slot (201) is formed on the upper baffle (103a), a locking belt (202) is provided between the first card slot (200) and the second card slot (201), and an inlet (203) is formed at the first card slot (200) and the second card slot (201); a first card slot (200) is formed on the lower baffle (103b), a second card slot (201) is formed on the upper baffle (103a), a locking belt (202) is provided between the first card slot (200) and the second card slot (201), and an inlet (203) is formed at the first card slot (200) and the second card slot (201); one end of the locking belt (202) is provided with a locking block (301), a locking cavity (302) is formed in the locking block (301), a plug (303) is provided on the other side of the locking belt (202), the locking belt (202) includes a plurality of component blocks (304) sequentially hinged at the ends, a winding column is provided in the locking cavity (302), a guide rail (306) is provided on the inner bottom surface of the locking cavity (302), the inner diameter of the guide rail (306) gradually increases from inside to outside, and a protrusion (400) is provided on the outer side of each component block (304).

2. The Miller cycle high tumble intake port according to claim 1, characterized in that: The height of the shielding member (103) is 0.2 - 4.0 mm, and the radial clearance between the shielding member (103) and the valve mechanism is 0.6 - 2.0 mm.

3. The Miller cycle high tumble intake port according to claim 2, characterized in that: An outlet groove is formed on the locking block (301), and an insertion groove is provided at one end of the locking block (301) away from the outlet groove.

4. A design method for a Miller cycle high tumble intake port, characterized in that: Including the Miller cycle high tumble intake passage according to any one of claims 1 to 3, the following steps are further included, According to the performance requirements of the engine, confirm the target of the flow coefficient and tumble ratio parameters of the intake passage (100); Pre-select a set of shielding member parameter combinations for shielding member design; Conduct numerical simulation analysis on the intake passage (100) model, calculate the flow coefficient and tumble ratio parameters at each lift, and compare the flow coefficient and tumble ratio parameters to select the target airway parameters.

5. The design method according to claim 4, characterized in that: The average flow coefficient of the intake port (100) needs to be not less than 0.

25. To cooperate with efficient combustion, the average tumble ratio of the intake port (100) needs to be higher than 2.

5.

6. The design method according to claim 4 or 5, characterized in that: Set the masking height to 0 - 4 mm, the masking angle range to 60 - 180°, and the valve masking clearance range to 0.6 - 2.0 mm.

7. The design method according to claim 6, characterized in that: If the flow coefficient meets the target but the tumble ratio is less than the target, then continue to reduce the d parameter or increase the h / A parameter within the parameter range. After determining a version of the intake port model scheme, repeat the above steps until both the flow coefficient and the tumble ratio meet the design target; If the tumble ratio parameter meets the design target but the flow coefficient is less than the target value, then correspondingly increase the d parameter or reduce the h / A parameter within the parameter range. After determining a version of the intake port model scheme, repeat the above steps until both the flow coefficient and the tumble ratio meet the design target; Wherein, h is the masking height, A is the masking angle range, and d is the valve masking clearance.

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