Engine air inlet system and two-stroke engine

Abstract

The engine air inlet system comprises an air cylinder sleeve and an air inlet cavity, an air cylinder cavity is formed in the air cylinder sleeve, a plurality of air inlets arranged at intervals in the circumferential direction are formed in the circumferential wall of the air cylinder sleeve, and the air inlet directions of the multiple air inlets are obliquely arranged in the same circumferential direction of the air cylinder sleeve; the air inlet cavity surrounds the peripheries of the multiple air cylinder sleeves, the air inlet communicates with the air cylinder cavity and the air inlet cavity, at least two air inlet pipelines arranged at intervals in the circumferential direction are arranged on the circumferential wall of the air inlet cavity, and the air inlet directions of the at least two air inlet pipelines are arranged along the inner circumferential wall of the air inlet cavity. The included angle between the air inlet and the air inlet direction of the air inlet close to the inner circumferential wall of the air inlet cavity is smaller than 90 degrees. Under the condition of the same inclination angle, compared with a traditional air channel, the swirl ratio is remarkably increased, on the premise that the air inlet flow coefficient of the two-stroke engine is the same as that of an existing two-stroke engine, the swirl ratio is increased, and the problem that the swirl ratio is low under the high flow coefficient of the traditional two-stroke engine is solved.

Description

Technical Field

[0001] This invention relates to the field of internal combustion engine technology, and in particular to an engine intake system and a two-stroke engine. Background Technology

[0002] Compared to four-stroke engines, two-stroke engines complete one power stroke per crankshaft revolution, resulting in higher torque, higher power output per liter, and superior performance. However, two-stroke engines also have inherent drawbacks: their intake and exhaust processes occur simultaneously, requiring intake air to remove exhaust gases from the cylinder, often leading to lower scavenging efficiency. Studies have shown that intake swirl can effectively improve scavenging efficiency, but enhancing the swirl (usually achieved by adjusting the intake port angle) often results in a decrease in the flow coefficient.

[0003] Currently, two-stroke engines generally adopt a single-channel or multi-channel same-side intake structure, which is beneficial to achieve uniform intake distribution and a high flow coefficient. However, if it is necessary to increase the swirl ratio, it still mainly relies on adjusting the intake port tilt angle, which in turn causes the flow coefficient to decrease again and increases the workload of the turbocharger. Summary of the Invention The present invention aims to at least solve one of the technical problems existing in the prior art. To this end, the present invention provides an engine intake system and a two-stroke engine, which can improve the vortex ratio while maintaining the same intake flow coefficient as existing two-stroke engines, thus solving the problem of low vortex ratio under high flow coefficients in traditional two-stroke engines.

[0004] The technical solution adopted to solve the above-mentioned technical problems is as follows: This invention provides an engine intake system, comprising: A cylinder liner is provided in multiple ways. The cylinder liner has a cylinder chamber inside. The peripheral wall of the cylinder liner has multiple air inlets arranged at intervals along the circumference. The air intake direction of the multiple air inlets is inclined along the same circumference of the cylinder liner. An intake chamber is provided, in which a plurality of cylinder liners are arranged sequentially at intervals. The intake chamber surrounds the outer periphery of the plurality of cylinder liners. An intake port is connected to the cylinder chamber and the intake chamber. The peripheral wall of the intake chamber is provided with at least two intake pipes arranged at intervals along the circumference. The intake direction of the at least two intake pipes is respectively arranged along the inner peripheral wall of the intake chamber, and the angle between them and the intake direction of the intake port near the inner peripheral wall of the intake chamber is less than 90 degrees.

[0005] The beneficial effects of the engine intake system of the present invention are: In use, this invention allows external air to flow into the intake chamber through at least two intake pipes in different directions, and then into the cylinder chamber via an inclined intake port, forming a vortex intake. The intake pipes are arranged along the inner circumferential wall of the intake chamber, and the angle between the intake pipes and the airflow direction of the intake port adjacent to the inner circumferential wall is less than 90 degrees. This ensures that the airflow direction entering through the intake pipes is consistent with the guide direction of the intake port, effectively reducing flow losses. Simultaneously, this design fully utilizes the guiding effect of the inclination angle of each intake port on the airflow. Under the same inclination angle, it significantly improves the vortex ratio compared to traditional intake ducts. This invention achieves a higher vortex ratio than existing two-stroke engines with the same intake flow coefficient, solving the problem of low vortex ratio under high flow coefficients in traditional two-stroke engines.

[0006] As a further improvement to the above technical solution, the sum of the air intake cross-sectional areas of at least two of the air intake pipes is greater than or equal to 1.5 times the sum of the air intake cross-sectional areas of all the air intake ports.

[0007] As a further improvement to the above technical solution, the cylinder center distance between two adjacent cylinder liners is greater than or equal to 1.4 times the cylinder diameter of the cylinder liner.

[0008] As a further improvement to the above technical solution, multiple cylinder liners are arranged sequentially at intervals along a straight line.

[0009] As a further improvement to the above technical solution, the air intake direction of the intake pipe is arranged parallel to the circumferential tangential direction of the cylinder liner near the intake pipe.

[0010] As a further improvement to the above technical solution, the intake chamber is provided with multiple partitions. The partitions are provided between two adjacent cylinder liners and between the cylinder liners at both ends and the inner peripheral wall of the intake chamber. The multiple partitions divide the intake chamber into two sub-chambers, and each sub-chamber is provided with an intake pipe.

[0011] As a further improvement to the above technical solution, the plurality of partitions include intermediate partitions and end partitions. The plurality of intermediate partitions are respectively disposed between two adjacent cylinder liners, and the two end partitions are respectively disposed between the cylinder liners at both ends and the inner peripheral wall of the intake chamber. The intermediate partitions are inclined, and the intake inclination direction of the intermediate partitions is the same as that of the intake ports on the cylinder liners on both sides.

[0012] As a further improvement to the above technical solution, the extension direction of the end partition is set in the same direction as the air intake direction of the air intake pipe.

[0013] As a further improvement to the above technical solution, the air intake direction of the intake pipe is set in the same direction as the arrangement direction of the plurality of cylinder liners.

[0014] The present invention also proposes a two-stroke engine, including the aforementioned engine intake system.

[0015] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. Attached Figure Description

[0016] The present invention will be further described below with reference to the accompanying drawings and embodiments; Figure 1 This is a structural schematic diagram of an embodiment of the engine intake system provided by the present invention, wherein the dashed arrow indicates the airflow direction; Figure 2 This is a schematic diagram of a second embodiment of the engine intake system provided by the present invention, wherein the dashed arrow indicates the airflow direction; Figure 3 This is a schematic diagram of the structure of a third embodiment of the engine intake system provided by the present invention, wherein the dashed arrows indicate the airflow direction; Figure 4 This is a structural schematic diagram of a fourth embodiment of the engine intake system provided by the present invention, wherein the dashed arrows indicate the airflow direction; Figure 5 This is a structural schematic diagram of a fifth embodiment of the engine intake system provided by the present invention, wherein the dashed arrow indicates the airflow direction; Icon labels: Cylinder liner 100; Cylinder chamber 110; Intake port 120; Air intake chamber 200; air intake pipe 210; sub-chamber 220; intermediate partition 230; end partition 240. Detailed Implementation

[0017] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0018] In the description of this invention, it should be understood that the orientation descriptions, such as up, down, etc., are based on the orientation or positional relationship shown in the drawings and are only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0019] In the description of this invention, "multiple" refers to two or more. The use of "first" and "second" is for distinguishing technical features only and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features or their sequential relationship.

[0020] In the description of this invention, unless otherwise explicitly defined, terms such as "set up," "install," and "connect" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this invention in conjunction with the specific content of the technical solution.

[0021] The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described below are some embodiments of the present invention, not all embodiments.

[0022] Currently, most two-stroke engines employ a single-channel or multi-channel same-side intake structure. While this structure provides good port uniformity and a high flow coefficient, the improvement in swirl ratio mainly relies on increasing the intake port angle by 120 degrees, which often leads to a decrease in the flow coefficient and consequently increases the workload of the turbocharger. Therefore, this invention proposes an engine intake system that can achieve a swirl ratio increase of over 80% while maintaining the same intake flow coefficient as existing two-stroke engines, thus solving the problem of low swirl ratio under high flow coefficient conditions in traditional two-stroke engines.

[0023] Reference Figures 1-5 The engine intake system of the present invention is provided in the following embodiments: Example 1: The engine intake system of this example includes a cylinder liner 100 and an intake chamber 200.

[0024] Among them, the cylinder liner 100 has multiple components, such as... Figure 1 As shown, this embodiment provides three cylinder liners 100, and the cylinder liner 100 has a cylinder chamber 110 inside. The cylinder liner 100 in this embodiment extends axially in the front-to-back direction, and the three cylinder liners 100 are arranged sequentially at intervals along a straight line. The three cylinder liners 100 in this embodiment are also arranged at intervals in the left-to-right direction.

[0025] The cylinder liner 100 has a plurality of air inlets 120 arranged at intervals along the circumference. The air intake direction of the plurality of air inlets 120 is inclined along the same circumference of the cylinder liner 100. It can be understood that the air inlets 120 are inclined on the circumference of the cylinder liner 100 according to a set angle. The air inlets 120 can be set with different angles to obtain intake vortices of different intensities.

[0026] In this embodiment, three cylinder liners 100 are arranged sequentially and spaced apart within the intake chamber 200, which surrounds the outer periphery of the three cylinder liners 100. The intake port 120 connects the cylinder chamber 110 and the intake chamber 200. The peripheral wall of the intake chamber 200 is provided with at least two intake pipes 210 spaced apart along the circumference. In this embodiment, two intake pipes 210 are provided. One intake pipe 210 is located at the lower left position of the intake chamber 200, and the airflow enters from the lower part of the intake chamber 200 from left to right, referred to as lower left intake. The other intake pipe 210 is located at the upper right position of the intake chamber 200, and the airflow enters from the upper part of the intake chamber 200 from right to left, referred to as upper right intake. The airflow enters the intake chamber 200 from different directions through the two intake pipes 210.

[0027] In some other embodiments, the air intake duct 210 may be provided in three or four, etc.

[0028] During use, external air flows into the intake chamber 200 from two intake pipes 210 in different directions, and then enters the cylinder chamber 110 through the inclined intake port 120, forming a vortex intake.

[0029] Currently available air ducts all use single or dual intake pipes, with air entering the intake chamber 200 from a single direction. Because the intake port 120 is designed with an angle, the direction of the incoming airflow will have a certain angle with the direction of the port's tilt. In traditional intake pipes, after the airflow enters the intake chamber 200, half of the intake port 120 has an angle less than 90 degrees with the airflow in the intake pipe, while the other half has an angle much greater than 90 degrees. When the angle between the intake port 120 and the airflow in the intake pipe is much greater than 90 degrees, the inclination angle of the intake port 120 cannot effectively guide the airflow. In other words, only half of the intake port 120 can fully utilize its inclination angle to guide the airflow, which makes it difficult to increase vortex volume.

[0030] In this embodiment, the two air intake pipes 210 are respectively arranged along the inner peripheral wall of the air intake chamber 200, and the angle between them and the air intake direction of the air inlet 120 near the inner peripheral wall of the air intake chamber 200 is less than 90 degrees. Figure 1 As shown, the angle between the air intake direction of the intake duct 210 and the air intake direction of the air inlet 120 near the inner peripheral wall of the intake chamber 200 is A, and the angle A is less than 90 degrees. This ensures that the airflow direction entering the intake duct 210 is consistent with the guidance of all the air inlets 120, effectively reducing flow loss. At the same time, it can give full play to the guiding effect of the inclination angle of each air inlet 120 on the airflow. Under the same inclination angle, the vortex ratio is significantly improved compared with the traditional air duct.

[0031] The intake chamber 200 of this embodiment is rectangular in shape, and the inner corners of the intake chamber 200 are rounded to guide the airflow and reduce resistance. At the same time, the intake direction of the intake pipe 210 is parallel to the circumferential tangential of the cylinder liner 100 near the intake pipe 210. After the airflow enters the intake chamber 200, it is guided by the outer peripheral wall of the cylinder liner 100 to flow through two adjacent cylinder liners 100.

[0032] The sum of the intake cross-sectional areas of the two intake pipes 210 is greater than or equal to 1.5 times the sum of the intake cross-sectional areas of all the intake ports 120, so as to ensure that it will not become a factor limiting the flow coefficient.

[0033] To ensure consistent air intake at each intake port 120, the cylinder center distance between two adjacent cylinder liners 100 is greater than or equal to 1.4 times the cylinder diameter of the cylinder liner 100.

[0034] In this case, the airflow from the two intake pipes 210 may interfere with each other, resulting in a decrease in intake flow rate of about 5%. If the inclination angle of the intake port 120 is reduced while keeping the flow coefficient constant, the vortex ratio can be increased by more than 85% compared to the traditional intake pipe.

[0035] Example 2: Compared to Example 1, this example has multiple baffles in the intake chamber 200 to isolate the airflow and prevent mutual interference between the intake airflows of the two intake pipes 210, which would lead to a decrease in the flow coefficient. Specifically, as shown in the example... Figure 2 As shown, in this embodiment, partitions are provided between two adjacent cylinder liners 100 and between the cylinder liners 100 at both ends and the inner peripheral wall of the intake chamber 200. Multiple partitions divide the intake chamber 200 into two sub-chambers 220, and two intake pipes 210 are respectively connected to the two sub-chambers 220.

[0036] The partition in this embodiment includes a middle partition 230 and end partitions 240. The middle partition 230 is disposed between two adjacent cylinder liners 100, and the two end partitions 240 are respectively disposed between the cylinder liners 100 at both ends and the inner peripheral wall of the intake chamber 200. The middle partition 230 is inclined and its inclination direction is the same as that of the intake ports 120 on the cylinder liners 100 on both sides. The extension direction of the end partitions 240 is the same as that of the intake pipe 210.

[0037] Compared to Embodiment 1 without baffles, the airflow of the two intake pipes 210 in this embodiment will not interfere with each other. However, each cylinder will have 1-2 intake ports 120 with an angle B between their tilt direction and the airflow direction. At this time, the angle B is slightly greater than 90 degrees. This allows more than 80% of the intake ports 120 to fully utilize the guiding effect of the port tilt angle on the airflow, while the guiding effect of the tilt angle of the remaining less than 20% of the intake ports 120 on the airflow will be weakened. However, compared with the traditional intake passage, the flow coefficient is the same when the tilt angle of the intake port 120 remains unchanged, and the vortex ratio can be increased by 80%-90%.

[0038] The air intake direction of the two air intake pipes 210 can also be changed according to different situations, as long as the air intake airflow is consistent with the tilt direction of the air intake port 120.

[0039] like Figure 3 As shown, in Embodiment 3, the two air intake pipes 210 are respectively located at the upper left and lower right positions of the air intake chamber 200.

[0040] like Figure 4 As shown, in Embodiment 4, the two air intake pipes 210 are respectively located at the lower left and lower right positions of the air intake chamber 200.

[0041] like Figure 5 As shown, in Embodiment 5, the two air intake pipes 210 are respectively located at the upper left and upper right positions of the air intake chamber 200.

[0042] The present invention also proposes a two-stroke engine, including the engine intake system described above.

[0043] The two-stroke engine of the present invention employs the above-described engine intake system and has the following beneficial effects: By using two intake pipes 210 to intake air from two different directions, it can be ensured that the tilt direction of all intake ports 120 is consistent with the airflow direction. Even if the airflow direction entering the intake pipe is consistent with the guide of the intake port 120, flow loss can be reduced. At the same time, the tilt angle of each intake port 120 can be fully utilized to guide the airflow, thereby improving the vortex ratio.

[0044] In the embodiment where no baffle is added inside the air intake chamber 200, the angle between the tilt direction of all air intakes 120 and the airflow direction is less than 90 degrees, and the tilt angle of all air intakes 120 can fully exert their guiding effect on the airflow. Compared with the traditional air intake, at the same air intake 120 tilt angle, the vortex ratio can be increased by 100%, but the flow coefficient will decrease by about 5%; if the tilt angle of the air intake 120 is reduced while keeping the flow coefficient unchanged, the vortex ratio can be increased by about 85%.

[0045] In the embodiment where a baffle is added within the intake chamber 200, the airflow from the two intake pipes 210 will not interfere with each other, and the flow coefficient will not decrease. However, the inclination angle of one or two intake ports 120 is slightly greater than 90 degrees from the airflow direction, and these one or two intake ports 120 cannot fully exert their guiding effect on the airflow. Compared to a conventional intake duct, the vortex ratio can be increased by 80-90% while maintaining the same flow coefficient.

[0046] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0047] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention.

Claims

1. An engine intake system, characterized in that, include: A cylinder liner is provided in multiple ways. The cylinder liner has a cylinder chamber inside. The peripheral wall of the cylinder liner has multiple air inlets arranged at intervals along the circumference. The air intake direction of the multiple air inlets is inclined along the same circumference of the cylinder liner. An intake chamber is provided, in which a plurality of cylinder liners are arranged sequentially at intervals. The intake chamber surrounds the outer periphery of the plurality of cylinder liners. An intake port is connected to the cylinder chamber and the intake chamber. The peripheral wall of the intake chamber is provided with at least two intake pipes arranged at intervals along the circumference. The intake direction of the at least two intake pipes is respectively arranged along the inner peripheral wall of the intake chamber, and the angle between them and the intake direction of the intake port near the inner peripheral wall of the intake chamber is less than 90 degrees.

2. The engine intake system according to claim 1, characterized in that: The sum of the intake cross-sectional areas of at least two of the intake pipes is greater than or equal to 1.5 times the sum of the intake cross-sectional areas of all the intake ports.

3. The engine intake system according to claim 1, characterized in that: The cylinder center distance between two adjacent cylinder liners is greater than or equal to 1.4 times the cylinder diameter of the cylinder liner.

4. The engine intake system according to claim 1, characterized in that: The cylinder liners are arranged sequentially at intervals along a straight line.

5. The engine intake system according to claim 1, characterized in that: The intake direction of the intake pipe is parallel to the circumferential tangential direction of the cylinder liner near the intake pipe.

6. The engine intake system according to any one of claims 1 to 5, characterized in that: The intake chamber is provided with multiple partitions. The partitions are provided between two adjacent cylinder liners and between the cylinder liners at both ends and the inner peripheral wall of the intake chamber. The multiple partitions divide the intake chamber into two sub-chambers, and each sub-chamber is provided with an intake pipe.

7. The engine intake system according to claim 6, characterized in that: The plurality of partitions include intermediate partitions and end partitions. The plurality of intermediate partitions are respectively disposed between two adjacent cylinder liners, and the two end partitions are respectively disposed between the cylinder liners at both ends and the inner peripheral wall of the intake chamber. The intermediate partitions are inclined, and the intake inclination direction of the intermediate partitions is the same as that of the intake ports on the cylinder liners on both sides.

8. The engine intake system according to claim 7, characterized in that: The extension direction of the end baffle is set in the same direction as the air intake direction of the air intake pipe.

9. The engine intake system according to claim 6, characterized in that: The intake direction of the intake pipe is the same as the arrangement direction of the plurality of cylinder liners.

10. A two-stroke engine, characterized in that: Includes the engine intake system as described in any one of claims 1 to 9.

Images