Two-stroke and four-stroke variable engine

Abstract

The invention relates to the technical field of engines, in particular to a two-four-stroke variable engine which comprises an air cylinder body and a piston arranged in the air cylinder body, and a main combustion chamber is defined between the air cylinder body and the top of the piston. The engine further comprises a first air inlet part, a second air inlet part and an exhaust valve, the first air inlet part is arranged at the top of the air cylinder body, when the engine is in a four-stroke mode, mixed gas is output to the main combustion chamber, and when the engine is in a two-stroke mode, the mixed gas is output to the main combustion chamber so that a first scavenging process and a second scavenging process can be conducted. The second air inlet part is arranged on the side portion of the air cylinder body, and when the engine is in the two-stroke mode, mixed gas is output to the main combustion chamber so that a second scavenging process and a third scavenging process can be conducted. The exhaust valve is arranged at the top of the air cylinder body and has an opening state and a closing state, and when the engine is in a two-stroke mode, the opening state is kept so as to be matched with the first air inlet part and the second air inlet part to conduct the first scavenging process, the second scavenging process and the third scavenging process.

Description

Technical Field

[0001] At least one embodiment of the present invention relates to the technical field of engines, and more specifically, to a two-stroke or four-stroke variable speed engine. Background Art

[0002] The two-stroke engine is widely used in small machines such as motorcycles, small ships, and chain saws due to its simple structure, light size, and high power density. Its working principle is to complete the suction, compression, and exhaust processes through the reciprocating motion of the piston, and to achieve ventilation by using the pressure difference generated by the scavenging pump or exhaust stroke. The two-stroke valve structure is simple, easy to maintain, and has a high power density.

[0003] The four-stroke engine is the most common type of engine in vehicles such as automobiles. It completes a complete working cycle through the four strokes of the piston: suction, compression, power, and exhaust. The combustion process of the four-stroke engine is more complete, the fuel economy is better, the emission of pollutants is relatively small, and it is easy to meet strict environmental standards. In addition, the lubrication system is more complete and the working conditions are relatively mild, so the life and reliability are higher.

[0004] In the related technologies, two-stroke engines and four-stroke engines also have some disadvantages, such as low combustion efficiency and high pollutant emissions of two-stroke engines; four-stroke engines have relatively low power density and insufficient response speed, which makes it difficult to meet high-power usage requirements. Therefore, how to optimize the engine structure to have the advantages of both two-stroke engines and four-stroke engines and adapt to more usage requirements has become a technical problem that needs to be solved urgently. Summary of the invention

[0005] In view of the above problems, the present invention provides a two-stroke and four-stroke variable engine. By optimizing the cylinder body and intake structure, the engine can switch between two-stroke mode and four-stroke mode according to actual working conditions, thereby combining the working advantages of both two-stroke engines and four-stroke engines.

[0006] In order to achieve the above-mentioned purpose, the present invention provides a two-four-stroke variable engine, including: a cylinder body and a piston arranged inside the above-mentioned cylinder body, a main combustion chamber is defined between the above-mentioned cylinder body and the top of the above-mentioned piston, and also includes: a first intake part, arranged at the top of the above-mentioned cylinder body, and configured to output a mixture to the above-mentioned main combustion chamber in response to the above-mentioned engine being in the four-stroke mode; and in response to the above-mentioned engine being in the two-stroke mode, output a mixture to the above-mentioned main combustion chamber to perform a first scavenging process and a second scavenging process; a second intake part, arranged at the side of the above-mentioned cylinder body, and configured to output a mixture to the above-mentioned main combustion chamber to perform a second scavenging process and a third scavenging process in response to the above-mentioned engine being in the two-stroke mode; an exhaust valve, arranged at the top of the above-mentioned cylinder body, having an open state and a closed state, and configured to maintain an open state in response to the above-mentioned engine being in the two-stroke mode to cooperate with the above-mentioned first intake part and the above-mentioned second intake part to perform the first scavenging process, the second scavenging process and the third scavenging process.

[0007] In an illustrative embodiment, the above-mentioned first intake part includes: an intake valve, which is arranged at the top of the above-mentioned cylinder body and has an open state and a closed state; a first intake duct, which is suitable for connecting the above-mentioned main combustion chamber with the outside world; and a fuel injector, which is installed on the side wall of the above-mentioned first intake duct and is suitable for injecting fuel into the above-mentioned first intake duct to form a mixture with air from the outside world.

[0008] In an illustrative embodiment, the second intake duct is adapted to guide the mixture in the first intake duct to the main combustion chamber; the valve is arranged in the second intake duct, adapted to switch the on / off state of the second intake duct, and is configured to open in response to the engine being in the two-stroke mode, and to close in response to the engine being in the four-stroke mode.

[0009] In an exemplary embodiment, an intake port is formed on the side of the cylinder block, which is suitable for connecting the second intake passage and the main combustion chamber. The intake port is configured to close in response to the piston being at the top dead center and to fully open when the piston is at the bottom dead center.

[0010] In an exemplary embodiment, the intake valve and the exhaust valve are configured to simultaneously maintain an open state in response to the piston descending from the top dead center to perform a first scavenging process and a second scavenging process.

[0011] In an illustrative embodiment, the intake valve is further configured to switch to a closed state in response to the piston moving upward from a bottom dead center to perform a third scavenging process.

[0012] In an exemplary embodiment, the exhaust valve is further configured to switch to a closed state to perform a compression stroke in a two-stroke mode in response to the piston moving upward to close the intake port.

[0013] In an illustrative embodiment, a plurality of the air inlets are provided and are spaced apart along the contour of the cylinder body.

[0014] In an illustrative embodiment, the air inlet is configured as a rectangular through hole.

[0015] In an illustrative embodiment, two first air intake portions are provided.

[0016] The two-stroke and four-stroke variable engine provided by the present invention, when the engine is in the four-stroke mode, the first air intake part provides a mixed gas to the main combustion chamber, and the suction, compression, power and exhaust strokes are carried out in coordination with the movement of the piston and the opening and closing of the exhaust valve. When the engine is in the two-stroke mode, in the first scavenging process, the first air intake part provides a mixed gas to the main combustion chamber, and the exhaust valve is opened to discharge the exhaust gas. In the second scavenging process, the first air intake part and the second air intake part simultaneously provide a mixed gas to the main combustion chamber, and the exhaust valve is opened to discharge the exhaust gas. In the third scavenging process, the second air intake part provides a mixed gas to the main combustion chamber, and the exhaust valve is opened to discharge the exhaust gas. After the third scavenging process, the exhaust valve will be closed, the mixed gas in the main combustion chamber is compressed and ignited, and after the mixed gas is burned and works, the first scavenging process to the third scavenging process of the next stroke will continue. Through the coordination between the first intake part, the second intake part and the exhaust valve, the engine can switch between the two-stroke mode and the four-stroke mode according to the actual working conditions. For example, when there is a high power output demand, the two-stroke mode is used to improve the power density; when the load is low or cruising, the four-stroke mode is used to improve fuel efficiency and reduce emissions, so that the engine has the advantages of both two-stroke engines and four-stroke engines when working. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The above and other objects, features and advantages of the present disclosure will become more apparent through the following description of the embodiments of the present disclosure with reference to the accompanying drawings, in which:

[0018] Figure 1 It is an overall schematic diagram of the two- and four-stroke variable engine provided by the present invention;

[0019] Figure 2 It is a three-dimensional schematic diagram of an enlarged cylinder body in a two- or four-stroke variable-speed engine provided by the present invention;

[0020] Figure 3 yes Figure 2 The illustrated exemplary embodiment is a perspective schematic diagram at another angle.

[0021] In the above drawings, the meanings of the reference numerals are as follows:

[0022] 1. Cylinder block;

[0023] 11. Air inlet;

[0024] 2. Piston;

[0025] 3. The first air intake portion;

[0026] 31. Intake valve;

[0027] 32. First air intake;

[0028] 33. Fuel injection nozzle;

[0029] 4. Second air intake;

[0030] 41. Second air intake;

[0031] 42. Valve

[0032] 5. Exhaust valve;

[0033] 6. Pre-combustion chamber;

[0034] 7. Spark plug;

[0035] 8. Oil supply device;

[0036] 81. Fuel tank;

[0037] 82. Common rail fuel system. DETAILED DESCRIPTION

[0038] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with specific embodiments and with reference to the accompanying drawings. The terms used herein are only for describing specific embodiments and are not intended to limit the present invention.

[0039] The terms "include", "comprising", etc. used herein indicate the presence of the features, steps, operations and / or components, but do not exclude the presence or addition of one or more other features, steps, operations or components. All terms used herein, including technical and scientific terms, have the meanings commonly understood by those skilled in the art unless otherwise defined. It should be noted that the terms used herein should be interpreted as having a meaning consistent with the context of this specification and should not be interpreted in an idealized or overly rigid manner.

[0040] In this document, unless otherwise specified, directional terms such as "upper", "lower", "left", "right", "inner", "outer", etc. are used to indicate the orientation or positional relationship based on the drawings, and are only for the convenience of describing the present invention, and do not indicate or imply that the device, element or component referred to must have a specific orientation, be constructed or operate in a specific orientation. It should be understood that when the absolute position of the described object changes, the relative positional relationship they represent may also change accordingly. Therefore, these directional terms should not be understood as limiting the present invention.

[0041] When using expressions such as "at least one of A, B, and C, etc.", it should generally be interpreted as the meaning of the expression generally understood by those skilled in the art. For example, "a system having at least one of A, B, and C" should include but not be limited to a system having A alone, B alone, C alone, A and B, A and C, B and C, and / or A, B, C, etc. When using expressions such as "at least one of A, B, or C, etc.", it should generally be interpreted as the meaning of the expression generally understood by those skilled in the art. For example, "a system having at least one of A, B, or C" should include but not be limited to a system having A alone, B alone, C alone, A and B, A and C, B and C, and / or A, B, C, etc.

[0042] It will be appreciated by those skilled in the art that the features described in the various embodiments and / or claims of the present invention may be combined and / or combined in various ways, even if such combinations and / or combinations are not explicitly described in the present invention. In particular, the features described in the various embodiments and / or claims of the present invention may be combined and / or combined in various ways without departing from the spirit and teachings of the present invention. All of these combinations and / or combinations fall within the scope of the present invention.

[0043] Figure 1 It is an overall schematic diagram of the two- and four-stroke variable engine provided by the present invention. Figure 2 It is a three-dimensional schematic diagram of the cylinder body of the two-stroke or four-stroke variable speed engine provided by the present invention after being enlarged. Figure 3 yes Figure 2 The illustrated exemplary embodiment is a perspective schematic diagram at another angle.

[0044] The exemplary embodiment of the present invention provides a two-stroke four-stroke variable speed engine, such as Figure 1As shown, it includes a cylinder body 1 and a piston 2 arranged inside the cylinder body 1, and a main combustion chamber is defined between the cylinder body 1 and the top of the piston 2. It also includes a first intake portion 3, a second intake portion 4 and an exhaust valve 5, wherein the first intake portion is arranged at the top of the cylinder body 1, and is configured to output a mixed gas to the main combustion chamber in response to the engine being in a four-stroke mode, and to output a mixed gas to the main combustion chamber in response to the engine being in a two-stroke mode to perform a first scavenging process and a second scavenging process. The second intake portion 4 is arranged at the side of the cylinder body 1, and is configured to output a mixed gas to the main combustion chamber in response to the engine being in a two-stroke mode to perform a second scavenging process and a third scavenging process. The exhaust valve 5 is arranged at the top of the cylinder body, has an open state and a closed state, and is configured to remain in an open state in response to the engine being in a two-stroke mode to cooperate with the first intake portion 3 and the second intake portion 4 to perform the first scavenging process, the second scavenging process and the third scavenging process.

[0045] In such an embodiment, when the engine is in a four-stroke mode, such as starting or low-load conditions, the first intake part 3 provides a mixed gas to the main combustion chamber, and the intake, compression, power, and exhaust strokes are performed in coordination with the movement of the piston and the opening and closing of the exhaust valve 5. When the engine is in a two-stroke mode, such as a high-load, high-power output condition, in the first scavenging process, the first intake part 3 provides a mixed gas to the main combustion chamber, and the exhaust valve 5 is opened to discharge the exhaust gas. In the second scavenging process, the first intake part 3 and the second intake part 4 simultaneously provide a mixed gas to the main combustion chamber, and the exhaust valve 5 is opened to discharge the exhaust gas. In the third scavenging process, the second intake part 4 provides a mixed gas to the main combustion chamber, and the exhaust valve 5 is opened to discharge the exhaust gas. After the third scavenging process, the engine in the two-stroke mode will close the exhaust valve 5, compress the mixed gas in the main combustion chamber, and ignite after compression, the mixed gas burns and performs work, and continues the first scavenging process to the third scavenging process of the next stroke. Through the coordination among the first air intake part 3, the second air intake part 4 and the exhaust valve 5, the engine can switch between the two-stroke mode and the four-stroke mode according to the actual working conditions. For example, when there is a high power output demand, the two-stroke mode is used to improve the power density; when the load is low or cruising, the four-stroke mode is used to improve fuel efficiency and reduce emissions, so that the engine has the advantages of both a two-stroke engine and a four-stroke engine when working.

[0046] According to an embodiment of the present disclosure, the first air intake portion 3 includes an air intake valve 31, a first air intake passage 32 and a fuel injector 33, wherein the air intake valve 31 is disposed at the top of the cylinder body 1 and has an open state and a closed state, and the first air intake passage 32 is adapted to connect the main combustion chamber with the outside. The fuel injector 33 is mounted on the side wall of the first air intake passage 32 and is adapted to inject fuel into the first air intake passage 32 to form a mixed gas with the air from the outside.

[0047] In such an embodiment, the intake valve 31 and the fuel injector 33 are both electrically connected to an electronic control unit of the engine, such as an ECU, to achieve a change in the operating frequency.

[0048] According to an embodiment of the present disclosure, the second intake portion 4 includes a second intake passage 41 and a valve 42. The second intake passage 41 is adapted to guide the mixed gas in the first intake passage 32 to the main combustion chamber. The valve 42 is arranged in the second intake passage 41, adapted to switch the on-off state of the second intake passage 41, and is configured to open in response to the engine being in the two-stroke mode, and to close in response to the engine being in the four-stroke mode.

[0049] In such an embodiment, one end of the second intake passage 41 is connected to the first intake passage 32, and the other end of the second intake passage 41 is connected to the main combustion chamber. The body of the second intake passage 41 is located outside the cylinder body 1 and is arranged around the cylinder body 1. The mixed gas output by the second intake portion 4 to the main combustion chamber comes from the first intake passage 32. In the four-stroke mode, the valve 42 is closed, and the mixed gas in the first intake passage 32 will not enter the main combustion chamber through the second intake passage 41. In the two-stroke mode, the valve 42 is opened, and the mixed gas can enter the main combustion chamber through the second intake passage 41 to perform the second scavenging process and the third scavenging process.

[0050] According to further embodiments of the present disclosure, Figure 2-Figure 3 As shown, an intake port 11 is formed on the side of the cylinder block 1 for connecting the second intake passage 41 and the main combustion chamber. The intake port 11 is configured to be closed in response to the piston 2 being at the top dead center and fully opened when the piston 2 is at the bottom dead center.

[0051] In such an embodiment, the second intake passage 41 is connected to the intake port 11 to deliver the mixed gas into the main combustion chamber. When the piston 2 is at the top dead center, the intake port 11 is completely blocked by the piston 2, and the mixed gas cannot enter the main combustion chamber. The piston 2 moves downward until the upper end surface of the piston 2 is lower than the upper end surface of the intake port 11, and the mixed gas begins to enter the main combustion chamber. When the piston 2 is at the bottom dead center, the upper end surface of the piston 2 is flush with the lower end surface of the intake port 11 (or lower than the lower end surface of the intake port 11), and the intake port 11 is not blocked by the piston 2 and is in a fully open state.

[0052] In an exemplary embodiment, the intake valve 31 and the exhaust valve 5 are configured to simultaneously maintain an open state in response to the piston 2 moving downward from the top dead center to perform the first scavenging process and the second scavenging process.

[0053] In such an embodiment, reference Figure 1 and Figure 2As shown, the process of the piston 2 descending from the top dead center until the upper end surface is flush with the upper end surface of the intake port 11 is the first scavenging process, in which the intake valve 31 is opened, the mixed gas enters the main combustion chamber, and the exhaust valve 5 is opened at the same time, and the exhaust gas is discharged from the main combustion chamber. The process of the piston 2 continuing to descend to the bottom dead center is the second scavenging process, in which the intake valve 31 and the exhaust valve 5 remain open, and the intake port 11 is gradually opened as the piston 2 descends, and the intake valve 31 and the intake port 11 simultaneously output the mixed gas to the main combustion chamber.

[0054] According to an embodiment of the present disclosure, the intake valve 31 is further configured to switch to a closed state in response to the piston 2 moving upward from the bottom dead center to perform a third scavenging process.

[0055] In such an embodiment, the piston 2 moves upward from the bottom dead center, the intake port 11 is gradually blocked by the piston 2, and the piston 2 pushes upward to squeeze the mixture in the main combustion chamber. During this process, the intake valve 31 will be closed to prevent the exhaust gas from entering the first intake duct 32 from the intake valve 31, causing the exhaust gas to flow back.

[0056] Further according to an embodiment of the present disclosure, the exhaust valve 5 is configured to switch to a closed state in response to the piston 2 moving upward to close the intake port 11 to perform a compression process in a two-stroke mode.

[0057] In such an embodiment, when the air inlet 11 is completely blocked, i.e. closed, the air inlet valve 31 is also closed, and the exhaust valve 5 is closed, and the piston 2 continues to move upward to compress the mixed gas. When the piston 2 runs to the top dead center, the mixed gas is ignited to do work, pushing the piston 2 downward, and the air inlet valve 31 and the exhaust valve 5 are opened, and the first scavenging process begins.

[0058] In an exemplary embodiment, a plurality of intake ports 11 are provided and are distributed at intervals along the contour of the cylinder block 1 .

[0059] In such an implementation, Figure 2-Figure 3 As shown, the cylinder block 1 is configured as a cylindrical body, and a plurality of intake ports 11 are arranged at intervals along the circumferential direction of the cylinder block 1 .

[0060] In an exemplary embodiment, Figure 2-Figure 3 As shown, the air inlet 11 is configured as a rectangular through hole.

[0061] In some other embodiments, the shape of the air inlet 11 includes but is not limited to a circular shape, an elliptical shape, and the like.

[0062] In an exemplary embodiment, two first air inlet portions 3 are provided.

[0063] In such an implementation, Figure 2-Figure 3As shown, two intake valves 31 are provided at the top of the cylinder block 1, which are used to switch the on and off states between the two first intake passages 32 and the main combustion chamber respectively. The two intake passages 32 will converge into the main intake passage of the engine to increase the intake volume of the cylinder block 1.

[0064] In some other embodiments, the above-mentioned two- or four-stroke variable engine also includes a precombustion chamber 6 and a spark plug 7. The precombustion chamber 6 is arranged at the top of the cylinder body 1. The first air intake part 3 is also configured to provide a mixture to the precombustion chamber 6. The spark plug 7 is suitable for igniting the mixture in the precombustion chamber 6. A jet flame nozzle is arranged at the bottom of the precombustion chamber 6 to form a jet flame after the mixture in the precombustion chamber 6 is ignited, thereby igniting the mixture in the main combustion chamber.

[0065] Further according to the embodiment of the present disclosure, the first air intake part 3 outputs the mixed gas to the pre-combustion chamber 6 through the second air intake duct 41, and the valve body 42 is a high-frequency solenoid valve, which adjusts the on-off frequency and the connection direction according to the operating frequency of the engine in the two-stroke mode, so that the first air intake part 3 and the second air intake part 4 can drive and cooperate in scavenging in the second scavenging process; and in the four-stroke mode, it is periodically connected to the pre-combustion chamber, and the jet flame energy is regulated by extending and shortening the closing time.

[0066] In some other exemplary embodiments, an airway bypass valve is further provided at the connection point between the second air intake passage 41 and the first air intake passage 32 .

[0067] In an exemplary embodiment, an electronic control unit and a variable cam control unit are also included. The electronic control unit is used to receive the working mode information of the engine, such as two-stroke or four-stroke, and is electrically connected to the fuel injector 33, the spark plug 7 and the valve body 42 to adjust parameters including but not limited to the fuel injection amount, the fuel injection frequency, the ignition frequency and the working parameters of the valve body 42. The variable cam control unit is also used to receive the working mode information of the engine, and is electrically connected to the cam mechanism of the engine to adjust the opening and closing of the intake valve 31 and the exhaust valve 5.

[0068] In some other exemplary embodiments, a fuel supply device 8 is further included. The fuel supply device 8 includes a fuel tank 81 and a fuel common rail mechanism 82 . The fuel common rail 82 draws fuel from the fuel tank 81 and delivers it to the fuel injector 33 .

[0069] The embodiments of the present invention are described above. However, these embodiments are only for the purpose of illustration, and are not intended to limit the scope of the present invention. Although each embodiment is described above, it does not mean that the measures in each embodiment cannot be used in combination. The scope of the present invention is defined by the attached claims and their equivalents. Without departing from the scope of the present invention, those skilled in the art may make various substitutions and modifications, which should all fall within the scope of the present invention.

Claims

1. A two-stroke or four-stroke variable speed engine, comprising a cylinder body (1) and a piston (2) arranged inside the cylinder body (1), wherein a main combustion chamber is defined between the cylinder body (1) and the top of the piston (2), and characterized in that: Also includes: A first air intake portion (3) is disposed on the top of the cylinder body (1) and is configured to output a mixed gas to the main combustion chamber in response to the engine being in a four-stroke mode; and in response to the engine being in a two-stroke mode, outputting the mixed gas to the main combustion chamber to perform a first scavenging process and a second scavenging process; A second intake portion (4) is disposed on a side of the cylinder body (1) and is configured to output a mixed gas to the main combustion chamber to perform a second scavenging process and a third scavenging process in response to the engine being in a two-stroke mode; An exhaust valve (5) is arranged at the top of the cylinder body (1), has an open state and a closed state, and is configured to maintain an open state in response to the engine being in a two-stroke mode to cooperate with the first intake portion (3) and the second intake portion (4) to perform a first scavenging process, a second scavenging process, and a third scavenging process.

2. The two-stroke or four-stroke variable speed engine according to claim 1, characterized in that: The first air intake portion (3) comprises: An intake valve (31) is arranged at the top of the cylinder body (1) and has an open state and a closed state; A first air inlet (32), adapted to connect the main combustion chamber to the outside; The fuel injection nozzle (33) is mounted on the side wall of the first air intake passage (32) and is suitable for injecting fuel into the first air intake passage (32) to form a mixed gas with air from the outside.

3. The two-stroke or four-stroke variable speed engine according to claim 2, characterized in that: The second air intake portion (4) comprises: A second air intake passage (41) adapted to guide the mixed gas in the first air intake passage (32) to the main combustion chamber; The valve (42) is arranged in the second air intake passage (41), is suitable for switching the on-off state of the second air intake passage (41), and is configured to open in response to the engine being in the two-stroke mode, and to close in response to the engine being in the four-stroke mode.

4. The two-stroke or four-stroke variable speed engine according to claim 3, characterized in that: An intake port (11) is formed on a side of the cylinder block (1) and is suitable for connecting the second intake passage (41) and the main combustion chamber. The intake port (11) is configured to be closed in response to the piston (2) being at the top dead center, and to be fully opened when the piston (2) is at the bottom dead center.

5. The two-stroke or four-stroke variable speed engine according to claim 4, characterized in that: The intake valve (31) and the exhaust valve (5) are configured to simultaneously maintain an open state in response to the piston (2) descending from the top dead center, so as to perform a first scavenging process and a second scavenging process.

6. The two-stroke or four-stroke variable speed engine according to claim 5, characterized in that: The intake valve (31) is also configured to switch to a closed state in response to the piston (2) moving upward from the bottom dead center to perform a third scavenging process.

7. The two-stroke or four-stroke variable speed engine according to claim 6, characterized in that: The exhaust valve (5) is also configured to switch to a closed state to perform a compression stroke in a two-stroke mode in response to the piston (2) moving upward to close the intake port (11).

8. The two-stroke or four-stroke variable speed engine according to claim 4, characterized in that: A plurality of air inlets (11) are provided, distributed at intervals along the contour line of the cylinder body (1).

9. The two-stroke or four-stroke variable speed engine according to claim 4, characterized in that: The air inlet (11) is configured as a rectangular through hole.

10. The two-stroke or four-stroke variable speed engine according to claim 4, characterized in that: Two first air intake parts (3) are provided.

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