Two-stroke engine and scavenging control system thereof

Abstract

The embodiment of the utility model discloses a two-stroke engine and a scavenging control system thereof, and relates to the technical field of engines. The scavenging control system is applied to the two-stroke engine and comprises a blocking piece and a driving device. The blocking piece is arranged in a containing cavity in the side face of an engine exhaust passage. The driving device is connected with the blocking piece and used for driving the blocking piece to reciprocate in the containing cavity and the engine exhaust passage so as to adjust the opening degree of an exhaust port of the engine exhaust passage. According to the scavenging control system provided by the utility model, the maximum power output of the engine can be improved on the premise of ensuring the fuel economy. According to the two-stroke engine, the opening degree of the exhaust port of the exhaust passage is adjusted through the scavenging control system, flexible output of engine power can be achieved, scavenging efficiency is improved, the engine power is improved, and the requirements of more application scenes are met.

Description

Technical Field

[0001] The utility model relates to the technical field of engines, in particular to a two-stroke engine and a scavenging control system thereof. Background Art

[0002] With the continuous decline of China's working-age population for many years, the steady increase of China's urbanization rate, the accelerating flow of rural population, and the continuous rise of labor costs, the development of mechanization has become a trend. At the same time, the increasing urban population density has brought about people's livelihood problems such as traffic congestion and public security. Driven by the general environment, industrial drones that can assist and replace manual labor have obtained great development impetus.

[0003] For electric drones, affected by the battery energy density, the endurance is short. And with the increase of endurance and power requirements, the weight and cost increase significantly, the battery charging time is long, and the endurance drops significantly in harsh usage environments such as low temperature. While for gasoline / extended-range drones, the engine power density is high and the endurance is long. Therefore, in scenarios such as agricultural and forestry plant protection / logistics with frequent short-term operations, medium / long endurance, large load capacity, meeting medium / long distance, cross-regional / sea-crossing transportation, and operation scenarios in mountainous areas, plateaus, and sea transportation that require low temperature resistance, high altitude resistance, and strong wind resistance, gasoline / extended-range drones cannot be replaced.

[0004] To meet the load requirements of drone application scenarios, the load efficiency of drone engines is particularly important, and the engine needs to achieve a higher power-to-weight ratio to improve efficiency. Compared with four-stroke engines, two-stroke engines have the advantages of small volume, light weight, large power-to-weight ratio, low cost, simple operation, and simple and convenient maintenance, and can better meet the needs of the drone market. However, due to structural constraints, traditional two-stroke engines are relatively sensitive to environmental factors such as operating altitude pressure and wind speed, which limits their usage scenarios.

[0005] For traditional two-stroke engines, the intake and exhaust channels are opened and closed through the reciprocating movement of the piston, and the scavenging process is difficult to control. In the low-altitude / low-load operating environment, the unburned mixture gas is easily directly discharged, resulting in low engine efficiency, high fuel consumption, and poor emissions; in the high-altitude / large-load operating environment, the exhaust gas cannot be quickly discharged, resulting in low engine power. It can be seen that traditional two-stroke engines are difficult to balance the requirements of fuel economy and power performance. Summary of the Utility Model

[0006] The technical problem to be solved by the embodiments of the utility model is the problem that traditional two-stroke engines are difficult to balance fuel economy and power performance.

[0007] To solve the above problems, the embodiments of the utility model provide the following technical solutions:

[0008] A scavenging control system is applied to a two-stroke engine and includes a blocking member and a driving device; the blocking member is arranged in a receiving cavity on the side of the engine exhaust passage; the driving device is connected to the blocking member and is used to drive the blocking member to reciprocate in the receiving cavity and in the engine exhaust passage so as to adjust the opening degree of the exhaust port of the engine exhaust passage.

[0009] Further, the blocking member includes a baffle portion, and the baffle portion is provided with a convex portion extending to the outer edge of the mouth of the receiving cavity, and the convex portion and the outer edge of the mouth of the receiving cavity form an upper limit structure.

[0010] Further, a motion track is arranged between the driving device and the blocking member, a stretching rod is arranged in the motion track, the driving device is connected to the blocking member through the stretching rod, and the motion track is communicated with the receiving cavity.

[0011] Further, a lower limit structure is arranged in the motion track for limiting the distance that the blocking member moves into the engine exhaust passage.

[0012] Further, the motion track includes a first track section and a second track section which are communicated with each other, and the inner diameter of the second track section is smaller than that of the first track section;

[0013] The stretching rod includes a connecting seat and a rod body; the connecting seat is located in the first track section, the outer diameter of the connecting seat is larger than the inner diameter of the second track section, and the connecting seat is connected to the driving device; the rod body is located in the second track section, one end of the rod body is connected to the connecting seat, and the other end of the rod body is connected to the blocking member;

[0014] The bottom of the first track section and the connecting seat form the lower limit structure.

[0015] Further, the blocking member further includes a connecting column arranged on the baffle portion, and the rod body is connected to the connecting column.

[0016] Further, the driving device includes a motor, the motor includes an output shaft, and the connecting seat is connected to the output shaft.

[0017] Further, the driving device further includes a motor controller, and the motor controller is connected to the motor.

[0018] Further, the two-stroke engine further includes an ECU, a speed sensor, and a throttle position sensor, the motor controller is connected to the ECU, and the ECU is connected to the speed sensor and the throttle position sensor.

[0019] The present utility model further provides a two-stroke engine including the above-mentioned scavenging control system.

[0020] Compared with the prior art, the technical effects that can be achieved by the embodiments of the present utility model include:

[0021] The scavenging control system provided by the present utility model uses a driving device to drive the blocking member to move up and down in the exhaust passage, so as to adjust the opening degree of the exhaust port of the exhaust passage, and further adjust the flexible output of the engine power. In a low-altitude / low-load operating environment, the scavenging control system adjusts the exhaust port to a low opening degree, which can reduce the fuel scavenging amount while ensuring power output, and reduce fuel consumption; in a high-altitude / high-load operating environment, the scavenging control system adjusts the exhaust port to a high opening degree to achieve a higher power output and improve the engine operating efficiency. The scavenging control system provided by the present utility model can enable the engine to improve the maximum power output on the premise of ensuring fuel economy.

[0022] The two-stroke engine provided by the present utility model can adjust the opening degree of the exhaust port of the exhaust passage by using the scavenging control system, which can realize the flexible output of the engine power, improve the scavenging efficiency, increase the engine power, and meet the requirements of more application scenarios. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0024] Figure 1 It is a schematic structural diagram of the scavenging control system according to the embodiment of the present utility model;

[0025] Figure 2 It is a schematic structural diagram of the connection between the blocking member and the driving device according to the embodiment of the present utility model;

[0026] Figure 3 is Figure 2 exploded view of;

[0027] Figure 4 It is a sectional view of the blocking member inside the cylinder according to the embodiment of the present utility model.

[0028] Reference numerals

[0029] Motor controller 1, motor 2, driving device 20, output shaft 21;

[0030] Tensile rod 3, connecting seat 31, rod body 32;

[0031] Blocking member 4, baffle portion 41, connecting column 42, convex portion 43;

[0032] First track section 51, second track section 52;

[0033] Exhaust passage 5, piston 6, intake passage 7, cylinder 8, combustion chamber 9, rotational speed sensor 10, throttle position sensor 11, ECU 12. Specific embodiments

[0034] Next, the technical solutions in the embodiments will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Similar component numbers in the drawings represent similar components. Obviously, the embodiments described below are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts fall within the protection scope of the present invention.

[0035] It should be understood that when used in this specification and the appended claims, the terms "comprising" and "including" indicate the presence of the described features, wholes, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, components, and / or their combinations.

[0036] It should also be understood that the terms used in the specification of the embodiments of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the embodiments of the present invention. As used in the specification of the embodiments of the present invention and the appended claims, unless the context clearly indicates otherwise, the singular forms "a", "an", and "the" are intended to include the plural forms.

[0037] See Figures 1-4 , the embodiments of the present invention provide a scavenging control system applied to a two-stroke engine. As can be seen from the figure, the two-stroke engine includes a cylinder 8, and the cylinder 8 includes a combustion chamber 9 and an exhaust passage 5 communicating with the combustion chamber 9. The scavenging control system provided in this embodiment includes a blocking member 4 and a driving device 20. The blocking member 4 is disposed in the accommodation cavity on the side of the engine exhaust passage 5, and the driving device 20 is connected to the blocking member 4. The driving device 20 is used to drive the blocking member 4 to move up and down in the accommodation cavity and in the exhaust passage 5 to adjust the opening degree of the exhaust port of the exhaust passage 5.

[0038] Specifically, in this embodiment, the blocking member 4 is disposed at the exhaust inlet position of the engine exhaust passage 5. The blocking member 4 is specifically an air passage baffle that can block part of the exhaust port. The blocking member 4 is disposed on the same side of the exhaust passage 5, and the driving device is used to drive the blocking member 4 to move up and down at the exhaust port to adjust the opening degree of the exhaust port of the exhaust passage 5, thereby flexibly adjusting the output of the engine power.

[0039] Further see Figure 2, in this embodiment, the blocking member 4 includes a baffle portion 41, and the baffle portion 41 is provided with a convex portion 43 extending to the outer edge of the opening of the accommodation cavity. The convex portion 43 and the outer edge of the opening of the accommodation cavity form an upper limit structure to limit the distance that the blocking portion 4 moves into the accommodation cavity.

[0040] In this embodiment, a movement track is provided between the driving device 20 and the blocking member 4. A tension rod 3 is arranged in the movement track, and the driving device 20 is connected to the blocking member 4 through the tension rod 3. The movement track is communicated with the accommodation cavity. The driving device 20 drives the tension rod 3 to reciprocate in the movement track, so that the blocking member 4 moves up and down at the exhaust port to adjust the opening degree of the exhaust port.

[0041] See Figure 4 , in this embodiment, a lower limit structure is arranged in the movement track to limit the distance that the blocking member 4 moves into the engine exhaust passage 5.

[0042] Specifically, the movement track includes a first track section 51 and a second track section 52 that are communicated with each other. The inner diameter of the second track section 52 is smaller than the inner diameter of the first track section 51;

[0043] The tension rod 3 includes a connecting seat 31 and a rod body 32; the connecting seat 31 is located in the first track section 51, and the outer diameter is larger than the inner diameter of the second track section 52. The connecting seat 31 is connected to the driving device 20; the rod body 32 is located in the second track section 52. One end of the rod body 32 is fixedly connected to the connecting seat 31, and the other end of the rod body 32 is connected to the blocking member 4; the bottom of the first track section 51 and the connecting seat 31 form the lower limit structure.

[0044] In this embodiment, by setting a segmented track, the driving device 20 drives the connecting seat 31 to move only within the length range of the first track section 51, so as to realize the adjustment of the maximum position and the minimum position of the opening degree of the exhaust port.

[0045] In other embodiments, the connecting seat 31 and the rod body 32 are integrally formed.

[0046] In this embodiment, the accommodation cavity is located at one end of the second track section 52 away from the first track section and is a part of the second track section 52.

[0047] It can be understood that according to the design of the exhaust port height of the exhaust passage 5, the full opening degree of the exhaust port is set as 1, and the exhaust volume is the largest in this state; the full closing of the exhaust port is set as 0, and there is no exhaust in this state. In this embodiment, the blocking member 4 is used to move at the exhaust port to block part of the exhaust port to adjust the opening degree of the exhaust port. Further, through the limit at the bottom of the first track section 51, the connecting seat 31 cannot enter the second track section 52. Those skilled in the art can flexibly adjust the opening degree of the exhaust port within the range of 0.3 - 1, preferably in the range of 0.5 - 1.

[0048] Further refer to Figure 3 In this embodiment, the driving device 20 includes a motor 2. The motor 2 includes an output shaft 21, and the output shaft 21 is connected to the stretching rod 3. The output shaft 21 converts the rotational motion of the motor 2 into a linear motion, thereby driving the stretching rod 3 to move.

[0049] In this embodiment, a motion track is provided on the side wall of the cylinder 8, and the stretching rod 3 slides in the motion track. The motion track plays a role in guiding and limiting. The motor 2 drives the stretching rod 3 to reciprocate in the motion track, and further drives the blocking member 4 to adjust the opening degree of the exhaust port.

[0050] Specifically, in this embodiment, the blocking member 4 further includes a connecting column 42 provided on the baffle portion 41. The outer surface of the connecting column 42 is provided with threads; the other end of the rod body 32 is provided with a first threaded hole, and the connecting column 42 is threadedly connected to the first threaded hole; the connecting seat 31 is connected to the output shaft 21.

[0051] In this embodiment, the connecting seat 31 is provided with a second threaded hole, the outer surface of the output shaft 21 is provided with threads, and the output shaft 21 is threadedly connected to the second threaded hole.

[0052] Please continue to refer to Figure 4 , part A in the figure shows a schematic diagram of the threaded connection between the connecting seat 31 and the output shaft 21; part B in the figure shows a schematic diagram of the threaded connection between the connecting column 42 and the rod body 32.

[0053] In this embodiment, the driving device further includes a motor controller 1, and the motor controller 1 is connected to the motor 2; the two-stroke engine further includes an ECU 12, a speed sensor 10, and a throttle position sensor 11. The motor controller 1 is connected to the ECU 12, and the ECU 12 is connected to the speed sensor 10 and the throttle position sensor 11.

[0054] The motor controller 1, the speed sensor 10, and the throttle position sensor 11 perform signal interaction through the engine ECU12. The motor controller 1 controls the operation of the motor 2 according to the instructions of the engine ECU12.

[0055] Further refer to Figures 1-4 , this embodiment further provides a two-stroke engine, including the scavenging control system described above.

[0056] The two-stroke engine provided in this embodiment adjusts the opening degree of the exhaust port by using the scavenging control system, and can realize flexible output of the engine power. The specific working principle is introduced as follows:

[0057] The operation of the engine realizes the opening and closing of the intake passage 7 and the exhaust passage 5 through the reciprocating up and down movement of the piston 6, forming a two-stroke combustion Otto cycle. In the structural design of the two-stroke engine, during the reciprocating up and down movement of the piston 6, there is a certain overlapping part between the airway opening of the intake passage 7 and the airway opening of the exhaust passage 5, so that part of the fresh air can enter the cavity through the intake passage 7, and push the residual exhaust gas after combustion out through the exhaust passage 5.

[0058] In a low-altitude / low-load operating environment, the engine operates in a low-speed and small-load region. The demand for fresh air in the cylinder is small and more residual exhaust gas can be tolerated. The rotational speed sensor 10 feeds back the low-speed signal to the engine ECU 12, and the throttle position sensor 11 feeds back the small-load signal to the engine ECU 12. The engine ECU 12 makes a judgment according to the program control logic stored in itself and conveys a downward instruction to the motor controller 1. Thus, the motor controller 1 controls the motor 2 to drive the stretching rod 3 to move downward in the movement track, and then drives the blocking member 4 to move downward to reduce the opening degree of the exhaust port of the exhaust passage 5, which can not only ensure power output but also reduce the fuel scavenging amount and lower fuel consumption.

[0059] In a high-altitude / high-load operating environment, the engine operates under high-load and high-speed conditions, and it is necessary to ensure the intake air volume and quickly scavenge the exhaust gas in the cylinder. The rotational speed sensor 10 feeds back the high-speed signal to the engine ECU 12, and the throttle position sensor 11 feeds back the high-load signal to the engine ECU 12. The engine ECU 12 makes a judgment according to the program control logic stored in itself and conveys an upward instruction to the motor controller 1. Thus, the motor controller 1 controls the motor 2 to drive the stretching rod 3 to move upward in the movement track, and then drives the blocking member 4 to move upward to reduce the opening degree of the exhaust port of the exhaust passage 5, so that the engine can achieve a higher power output.

[0060] In this embodiment, through the scavenging control system, the height of the scavenging port is controlled to flexibly adjust the power output of the engine, effectively improving the scavenging efficiency, enhancing the engine power, and meeting the requirements of more application scenarios.

[0061] In the above embodiments, the descriptions of each embodiment have their own emphases. For the parts not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0062] In the description of the present utility model, it should be understood that the orientation or positional relationships indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc. are based on the orientation or positional relationships shown in the drawings. These are only for the convenience of describing the present utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting the present utility model.

[0063] In addition, the terms "first" and "second" are only used for descriptive purposes and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present utility model, "a plurality of" means two or more, unless otherwise specifically defined.

[0064] In the present utility model, unless otherwise clearly defined and limited, the terms "mounted", "connected", "coupled", "fixed", etc. shall be construed in a broad sense. For example, it may be a connection, a detachable connection, or integrated; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the communication inside two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.

[0065] In the present utility model, unless otherwise clearly defined and limited, the first feature being "above" or "below" the second feature may include the first and second features being in direct contact, or may include the first and second features not being in direct contact but in contact through additional features therebetween. Moreover, the first feature being "above", "over" and "on" the second feature includes the first feature being directly above and obliquely above the second feature, or merely indicating that the first feature has a higher horizontal height than the second feature. The first feature being "under", "beneath" and "under" the second feature includes the first feature being directly below and obliquely below the second feature, or merely indicating that the first feature has a lower horizontal height than the second feature.

[0066] In the description of this specification, the descriptions referring to terms such as "one embodiment", "some embodiments", "examples", "specific examples", or "some examples", etc. mean that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present utility model. In this specification, the schematic expressions of the above terms should not be understood as necessarily referring to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples. In addition, those skilled in the art can combine and combine the different embodiments or examples described in this specification.

[0067] Obviously, those skilled in the art can make various changes and modifications to the present utility model without departing from the spirit and scope of the present utility model. Thus, provided that these modifications and variations of the present utility model fall within the scope of the claims of the present utility model and their equivalent technologies, the present utility model also intends to include these changes and modifications therein.

[0068] As described above, the above is the specific implementation manner of the present utility model, but the protection scope of the present utility model is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present utility model can easily think of various equivalent modifications or substitutions, and these modifications or substitutions should all be covered by the protection scope of the present utility model. Therefore, the protection scope of the present utility model shall be subject to the protection scope of the claims.

Claims

1. A scavenging control system, applied to a two-stroke engine, characterized in that: It comprises a blocking member and a driving device; the blocking member is arranged in a containing cavity on the side of the engine exhaust passage; the driving device is connected to the blocking member and is used to drive the blocking member to reciprocate in the containing cavity and the engine exhaust passage to adjust the exhaust port opening of the engine exhaust passage.

2. The scavenging control system according to claim 1, characterized in that: The blocking member comprises a baffle portion, wherein the baffle portion is provided with a convex portion extending to the outer edge of the accommodating cavity mouth portion, and the convex portion and the outer edge of the accommodating cavity mouth portion form an upper limit structure.

3. The scavenging control system according to claim 2, characterized in that: A moving track is arranged between the driving device and the blocking member, a stretching rod is arranged in the moving track, the driving device is connected to the blocking member via the stretching rod, and the moving track is communicated with the accommodating cavity.

4. The scavenging control system according to claim 3, characterized in that: A lower limit structure is arranged in the moving track, which is used to limit the distance that the blocking member moves into the exhaust passage of the engine.

5. The scavenging control system according to claim 4, characterized in that: The motion track comprises a first track segment and a second track segment which are connected to each other, and the inner diameter of the second track segment is smaller than the inner diameter of the first track segment; The stretching rod comprises a connecting seat and a rod body; the connecting seat is located in the first track segment, the outer diameter of the connecting seat is larger than the inner diameter of the second track segment, and the connecting seat is connected to the driving device; the rod body is located in the second track segment, one end of the rod body is connected to the connecting seat, and the other end of the rod body is connected to the blocking member; The bottom of the first track segment and the connecting seat form the lower limit structure.

6. The scavenging control system according to claim 5, characterized in that: The blocking member further comprises a connecting column arranged on the baffle portion, and the rod body is connected to the connecting column.

7. The scavenging control system according to claim 5, characterized in that: The driving device comprises a motor, the motor comprises an output shaft, and the connecting seat is connected to the output shaft.

8. The scavenging control system according to claim 7, characterized in that: The driving device further comprises a motor controller, and the motor controller is connected to the motor.

9. The scavenging control system according to claim 8, characterized in that: The two-stroke engine further comprises an ECU, a rotation speed sensor and a throttle position sensor. The motor controller is connected to the ECU, and the ECU is connected to the rotation speed sensor and the throttle position sensor.

10. A two-stroke engine, characterized in that: Comprising a scavenging control system as described in any one of claims 1-9.

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