Two four stroke variable engine

Abstract

The application relates to the engine technical field, and particularly provides a two-four stroke variable engine, which comprises a cylinder body, a piston arranged in the cylinder body, and a main combustion chamber defined between the 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 cylinder body and outputs mixed gas to the main combustion chamber when the engine is in a four-stroke mode, and outputs mixed gas to the main combustion chamber to perform a first scavenging process and a second scavenging process when the engine is in a two-stroke mode. The second air inlet part is arranged at the side of the cylinder body and outputs mixed gas to the main combustion chamber to perform a second scavenging process and a third scavenging process when the engine is in the two-stroke mode. The exhaust valve is arranged at the top of the cylinder body and has an open state and a closed state, and is kept in the open state to cooperate with the first air inlet part and the second air inlet part to perform the first scavenging process, the second scavenging process and the third scavenging process when the engine is in the two-stroke mode.

Description

Technical Field

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

[0002] Two-stroke engines are widely used in small machinery such as motorcycles, small boats, and chainsaws due to their simple structure, compact size, and high power density. Their working principle involves the reciprocating motion of the piston to complete the intake, compression, and exhaust processes, while scavenging is achieved using the pressure difference generated by the scavenging pump or the exhaust stroke. Two-stroke engines have a simple valve structure, are easy to maintain, and offer high power density.

[0003] Four-stroke engines are the most common type of engine in automobiles and other vehicles. They complete a full working cycle through four strokes of the piston: intake, compression, power, and exhaust. Four-stroke engines have a more complete combustion process, resulting in better fuel economy, relatively lower emissions, and easier compliance with stringent environmental standards. Furthermore, their lubrication systems are more sophisticated, and their operating conditions are relatively mild, leading to longer lifespans and higher reliability.

[0004] In related technologies, both two-stroke and four-stroke engines have their own drawbacks. For example, two-stroke engines have low combustion efficiency and high pollutant emissions; four-stroke engines have relatively low power density and insufficient response speed, making it difficult to meet the demands of high-power applications. Therefore, how to optimize the engine structure to combine the advantages of both two-stroke and four-stroke engines and adapt to more application needs has become an urgent technical problem to be solved. 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 block and intake structure, the engine can switch between two-stroke mode and four-stroke mode according to actual working conditions, thus combining the advantages of both two-stroke and four-stroke engines.

[0006] To achieve the above objectives, the present invention provides a two- or four-stroke variable displacement engine, comprising: a cylinder block and a piston disposed inside the cylinder block, wherein a main combustion chamber is defined between the cylinder block and the top of the piston; and further comprising: a first intake portion disposed at the top of the cylinder block, configured to output a mixture to the main combustion chamber in response to the engine being in a four-stroke mode; and to output a mixture to the main combustion chamber in response to the engine being in a two-stroke mode for performing a first scavenging process and a second scavenging process; a second intake portion disposed at the side of the cylinder block, configured to output a mixture to the main combustion chamber in response to the engine being in a two-stroke mode for performing a second scavenging process and a third scavenging process; and an exhaust valve disposed at the top of the cylinder block, having an open state and a closed state, configured to remain open in response to the engine being in a two-stroke mode to cooperate with the first intake portion and the second intake portion in performing the first scavenging process, the second scavenging process, and the third scavenging process.

[0007] In one illustrative embodiment, the first intake section includes: an intake valve disposed on the top of the cylinder block, having an open state and a closed state; a first intake passage adapted to connect the main combustion chamber to the outside; and a fuel injector installed on the side wall of the first intake passage, adapted to inject fuel into the first intake passage to form a mixture with air from the outside.

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

[0009] In one illustrative embodiment, an air intake is formed on the side of the cylinder block, which is adapted to connect the second air intake passage and the main combustion chamber. The air intake is configured to close in response to the piston being at top dead center and to fully open in response to the piston being at bottom dead center.

[0010] In one illustrative embodiment, the intake valve and the exhaust valve are configured to remain open simultaneously in response to the piston descending from top dead center, so as to perform a first scavenging process and a second scavenging process.

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

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

[0013] In one illustrative embodiment, multiple air inlets are provided and distributed at intervals along the outline of the cylinder block.

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

[0015] In one illustrative embodiment, two first air intakes are provided.

[0016] The two-stroke / four-stroke variable displacement engine provided by this invention, in four-stroke mode, supplies a mixture to the main combustion chamber via the first intake section, and performs intake, compression, power, and exhaust strokes in coordination with the piston movement and the opening and closing of the exhaust valve. In two-stroke mode, during the first scavenging process, the first intake section supplies a mixture to the main combustion chamber, while the exhaust valve opens to discharge exhaust gases. During the second scavenging process, both the first and second intake sections supply a mixture to the main combustion chamber, while the exhaust valve opens to discharge exhaust gases. During the third scavenging process, the second intake section supplies a mixture to the main combustion chamber, while the exhaust valve opens to discharge exhaust gases. After the third scavenging process, the exhaust valve closes, the mixture in the main combustion chamber is compressed and ignited, and after combustion and power generation, the next stroke continues with the first scavenging process through the third scavenging process. Through the coordination between the first intake section, the second intake section, and the exhaust valve, the engine can switch between two-stroke mode and four-stroke mode according to actual operating conditions. For example, when there is a demand for high power output, the two-stroke mode is used to increase power density; when the load is low or during 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 and four-stroke engines when it is working. Attached Figure Description

[0017] The above and other objects, features and advantages of this disclosure will become clearer from the following description of embodiments with reference to the accompanying drawings, in which:

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

[0019] Figure 2 This is a magnified three-dimensional schematic diagram of the cylinder block in the two- or four-stroke variable engine provided by the present invention.

[0020] Figure 3 yes Figure 2 The exemplary embodiment shown is a perspective view from another angle.

[0021] The meanings of the reference numerals in the above figures are as follows:

[0022] 1. Cylinder block;

[0023] 11. Air intake;

[0024] 2. Piston;

[0025] 3. First air intake section;

[0026] 31. Intake valve;

[0027] 32. First air intake;

[0028] 33. Fuel injectors;

[0029] 4. Second air intake;

[0030] 41. Second air intake;

[0031] 42. Valves;

[0032] 5. Exhaust valve;

[0033] 6. Pre-combustion chamber;

[0034] 7. Spark plugs;

[0035] 8. Oil supply device;

[0036] 81. Fuel tank;

[0037] 82. Common rail fuel system. Detailed Implementation

[0038] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments and the accompanying drawings. The terminology used herein is merely for describing specific embodiments and is not intended to limit the invention.

[0039] The terms “comprising,” “including,” etc., as used herein indicate the presence of the described features, steps, operations, and / or components, but do not preclude 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 are to be interpreted in a manner consistent with the context of this specification and not in an idealized or overly rigid way.

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

[0041] When using expressions such as "at least one of A, B, and C," the meaning should generally be interpreted according to the understanding of someone skilled in the art. For example, "a system having at least one of A, B, and C" should include, but is not limited to, systems having A alone, having B alone, having C alone, having A and B, having A and C, having B and C, and / or having A, B, and C. Similarly, when using expressions such as "at least one of A, B, or C," the meaning should generally be interpreted according to the understanding of someone skilled in the art. For example, "a system having at least one of A, B, or C" should include, but is not limited to, systems having A alone, having B alone, having C alone, having A and B, having A and C, having B and C, and / or having A, B, and C.

[0042] Those skilled in the art will understand that the features described in the various embodiments and / or claims of the present invention can be combined or combined in various ways, even if such combinations 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 can be combined or combined in various ways without departing from the spirit and teachings of the present invention. All such combinations and / or combinations fall within the scope of the present invention.

[0043] Figure 1 This is an overall schematic diagram of the two- or four-stroke variable displacement engine provided by the present invention. Figure 2 This is a magnified three-dimensional schematic diagram of the cylinder block in the two- or four-stroke variable displacement engine provided by this invention. Figure 3 yes Figure 2 The exemplary embodiment shown is a perspective view from another angle.

[0044] An exemplary embodiment of the present invention provides a two-to-four-stroke variable displacement engine, such as... Figure 1As shown, the system includes a cylinder block 1 and a piston 2 disposed inside the cylinder block 1, with a main combustion chamber defined between the top of the cylinder block 1 and the piston 2. It also includes a first intake section 3, a second intake section 4, and an exhaust valve 5. The first intake section is disposed at the top of the cylinder block 1 and configured to output a mixture to the main combustion chamber in response to the engine being in four-stroke mode, and to output a mixture to the main combustion chamber in response to the engine being in two-stroke mode for a first scavenging process and a second scavenging process. The second intake section 4 is disposed on the side of the cylinder block 1 and configured to output a mixture to the main combustion chamber in response to the engine being in two-stroke mode for a second scavenging process and a third scavenging process. The exhaust valve 5 is disposed at the top of the cylinder block and has an open state and a closed state. It is configured to remain open in response to the engine being in two-stroke mode to cooperate with the first intake section 3 and the second intake section 4 in the first, second, and third scavenging processes.

[0045] In this implementation, when the engine is in four-stroke mode, such as during start-up or low-load conditions, the first intake section 3 supplies the air-fuel mixture to the main combustion chamber, and the intake, compression, power, and exhaust strokes occur in coordination with the piston movement and the opening and closing of the exhaust valve 5. When the engine is in two-stroke mode, such as under high-load, high-power output conditions, during the first scavenging process, the first intake section 3 supplies the air-fuel mixture to the main combustion chamber, while the exhaust valve 5 opens to expel exhaust gases. During the second scavenging process, the first intake section 3 and the second intake section 4 simultaneously supply the air-fuel mixture to the main combustion chamber, while the exhaust valve 5 opens to expel exhaust gases. During the third scavenging process, the second intake section 4 supplies the air-fuel mixture to the main combustion chamber, while the exhaust valve 5 opens to expel exhaust gases. After the third scavenging process, the two-stroke engine closes the exhaust valve 5, compresses the air-fuel mixture in the main combustion chamber, and ignites it after compression. The air-fuel mixture burns to perform power, and the next stroke continues with the first scavenging process through the third scavenging process. Through the cooperation between the first intake section 3, the second intake section 4, and the exhaust valve 5, the engine can switch between two-stroke mode and four-stroke mode according to actual operating conditions. For example, when there is a demand for high power output, the two-stroke mode is used to increase power density; when the load is low or during 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 and four-stroke engines when it is working.

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

[0047] In this implementation, both the intake valve 31 and the fuel injector 33 are electrically connected to the engine's electronic control unit, such as the ECU, to achieve changes in operating frequency.

[0048] According to an embodiment of this disclosure, the second intake section 4 includes a second intake passage 41 and a valve 42. The second intake passage 41 is adapted to guide the air-fuel mixture in the first intake passage 32 to the main combustion chamber. The valve 42 is disposed within the second intake passage 41 and is 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 two-stroke mode and close in response to the engine being in four-stroke mode.

[0049] In this implementation, one end of the second intake manifold 41 is connected to the first intake manifold 32, and the other end is connected to the main combustion chamber. The body of the second intake manifold 41 is located outside the cylinder block 1 and is arranged around the cylinder block 1. The air-fuel mixture output from the second intake manifold 4 to the main combustion chamber comes from the first intake manifold 32. In four-stroke mode, the valve 42 is closed, and the air-fuel mixture in the first intake manifold 32 will not enter the main combustion chamber through the second intake manifold 41. In two-stroke mode, the valve 42 is open, and the air-fuel mixture can enter the main combustion chamber through the second intake manifold 41 for the second and third scavenging processes.

[0050] Further according to embodiments of this disclosure, such as Figures 2-3 As shown, an air inlet 11 is formed on the side of the cylinder block 1, which is adapted to connect the second air intake 41 and the main combustion chamber. The air inlet 11 is configured to close in response to the piston 2 being at top dead center and to fully open in response to the piston 2 being at bottom dead center.

[0051] In this embodiment, the second intake duct 41 is connected to the intake port 11 to deliver the air-fuel mixture into the main combustion chamber. When the piston 2 is at top dead center, the intake port 11 is completely blocked by the piston 2, and the air-fuel mixture cannot enter the main combustion chamber. As the piston 2 moves downward, until the upper end face of the piston 2 is lower than the upper end face of the intake port 11, the air-fuel mixture begins to enter the main combustion chamber. When the piston 2 is at bottom dead center, the upper end face of the piston 2 is flush with (or lower than) the lower end face 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 one exemplary embodiment, the intake valve 31 and the exhaust valve 5 are configured to remain open simultaneously in response to the piston 2 descending from top dead center to perform a first scavenging process and a second scavenging process.

[0053] In this implementation method, refer to Figure 1 and Figure 2As shown, the process of piston 2 descending from top dead center to its upper end face being flush with the upper end face of intake port 11 is the first scavenging process. During this process, intake valve 31 opens, and the air-fuel mixture enters the main combustion chamber. At the same time, exhaust valve 5 opens, and exhaust gas is discharged from the main combustion chamber. The process of piston 2 continuing to descend to bottom dead center is the second scavenging process. During this process, intake valve 31 and exhaust valve 5 remain open, and intake port 11 also gradually opens as piston 2 descends. Intake valve 31 and intake port 11 simultaneously output air-fuel mixture to the main combustion chamber.

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

[0055] In this implementation, the piston 2 moves upward from the bottom dead center, and the intake port 11 is gradually blocked by the piston 2. The piston 2 pushes upward to compress the air-fuel mixture in the main combustion chamber. During this process, the intake valve 31 will be closed to prevent exhaust gas from entering the first intake passage 32 from the intake valve 31, which would cause exhaust gas backflow.

[0056] According to a further 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, so as to perform the compression process in two-stroke mode.

[0057] In this implementation, when the intake port 11 is completely blocked (closed), the intake valve 31 is also closed. At this time, the exhaust valve 5 is closed, and the piston 2 continues to move upward to compress the air-fuel mixture. When the piston 2 reaches top dead center, the air-fuel mixture is ignited and does work, pushing the piston 2 downward. The intake valve 31 and the exhaust valve 5 then open, entering the first scavenging process.

[0058] In one exemplary embodiment, multiple air intakes 11 are provided and are spaced apart along the outline of the cylinder body 1.

[0059] In such an implementation, such as Figures 2-3 As shown, the cylinder block 1 is constructed as a cylindrical body, and multiple air inlets 11 are arranged at intervals along the circumferential direction of the cylinder block 1.

[0060] In one exemplary embodiment, such as Figures 2-3 As shown, the air inlet 11 is constructed as a rectangular through hole.

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

[0062] In one exemplary embodiment, two first air intakes 3 are provided.

[0063] In such an implementation, such as Figures 2-3As shown, two intake valves 31 are provided at the top of the cylinder block 1, which are used to switch the on / off state between the two first intake passages 32 and the main combustion chamber. The two first 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 pre-combustion chamber 6 and a spark plug 7. The pre-combustion chamber 6 is disposed at the top of the cylinder block 1. The first intake section 3 is also configured to provide a mixture to the pre-combustion chamber 6. The spark plug 7 is suitable for igniting the mixture in the pre-combustion chamber 6. A jet flame nozzle is provided at the bottom of the pre-combustion chamber 6 so that after the mixture in the pre-combustion chamber 6 is ignited, a jet flame is formed to ignite the mixture in the main combustion chamber.

[0065] According to further embodiments of this disclosure, the first intake section 3 outputs a mixture to the pre-combustion chamber 6 through the second intake passage 41. The valve 42 is a high-frequency solenoid valve, which adjusts the on / off frequency and connection direction according to the engine's operating frequency in two-stroke mode, so that the first intake section 3 and the second intake section 4 perform displacement and coordinated scavenging in the second scavenging process; and in four-stroke mode, it periodically connects with the pre-combustion chamber and regulates the jet flame energy by extending and shortening the closing time.

[0066] In some other exemplary embodiments, a bypass valve is also provided at the connection between the second air intake 41 and the first air intake 32.

[0067] In one exemplary embodiment, the system further includes an electronic control unit (ECU) and a variable camshaft control unit. The ECU receives engine operating mode information, such as two-stroke or four-stroke, and is electrically connected to the fuel injector 33, spark plug 7, and valve 42 to adjust, but is not limited to, fuel injection quantity, fuel injection frequency, ignition frequency, and operating parameters of valve 42. The variable camshaft control unit also receives engine operating mode information and is electrically connected to the engine's camshaft mechanism to control the opening and closing of the intake valve 31 and exhaust valve 5.

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

[0069] The embodiments of the present invention have been described above. However, these embodiments are merely illustrative and not intended to limit the scope of the invention. Although various embodiments have been described above, this does not mean that the measures in the various embodiments cannot be used advantageously in combination. The scope of the invention is defined by the appended claims and their equivalents. Various substitutions and modifications can be made by those skilled in the art without departing from the scope of the invention, and all such substitutions and modifications should fall within the scope of the invention.

Claims

1. A two- or four-stroke variable displacement engine, comprising a cylinder block (1) and a piston (2) disposed inside the cylinder block (1), wherein a main combustion chamber is defined between the cylinder block (1) and the top of the piston (2), characterized in that, Also includes: The first intake section (3) includes a first intake passage (32) for communicating the main combustion chamber with the outside. The first intake section (3) is disposed on the top of the cylinder block (1) and is configured to output a mixture to the main combustion chamber in response to the engine being in four-stroke mode. And in response to the engine being in two-stroke mode, a mixture is output to the main combustion chamber for a first scavenging process and a second scavenging process; A second intake section (4) is disposed on the side of the cylinder block (1) and configured to output a mixture to the main combustion chamber in response to the engine being in two-stroke mode for performing a second scavenging process and a third scavenging process. The second intake section (4) includes: The second air intake (41) is adapted to guide the air-fuel mixture in the first air intake (32) to the main combustion chamber; A valve (42) is arranged in the second air intake (41) and is suitable for switching the on / off state of the second air intake (41); The exhaust valve (5) is located on the top of the cylinder block (1) and has an open state and a closed state. It is configured to remain open in response to the engine being in two-stroke mode to cooperate with the first intake section (3) and the second intake section (4) to perform a first scavenging process, a second scavenging process and a third scavenging process. The first intake section includes an intake valve, which is disposed on the top of the cylinder block and has an open state and a closed state; The intake valve and the exhaust valve are configured to remain open simultaneously in response to the piston moving downward from top dead center, to perform a first scavenging process and a second scavenging process. The intake valve is also configured to switch to a closed state in response to the piston moving upward from bottom dead center to perform a third scavenging process; The cylinder block has an air inlet formed on its side, which is suitable for connecting the second air intake passage and the main combustion chamber; The exhaust valve is also configured to switch to a closed state in response to the piston moving upward to close the intake port for the compression stroke in two-stroke mode; A pre-combustion chamber is disposed at the top of the cylinder block, and the first intake section is further configured to provide a mixture to the pre-combustion chamber; A spark plug is used to ignite the gas mixture in the pre-combustion chamber, and the bottom of the pre-combustion chamber is provided with a jet flame nozzle so that a jet flame is formed after the gas mixture in the pre-combustion chamber is ignited. The valve is configured to open in response to the engine being in two-stroke mode to output a mixture to the pre-combustion chamber through the second intake duct and to perform scavenging in conjunction with the first and second intake sections; and to periodically open and close in response to the engine being in four-stroke mode to regulate the jet flame energy injected into the main combustion chamber.

2. The two- or four-stroke variable displacement engine according to claim 1, characterized in that, The first air intake (3) also includes: The fuel injector (33) is installed on the side wall of the first air intake (32) and is suitable for injecting fuel into the first air intake (32) to form a mixture with the air from the outside.

3. The two- or four-stroke variable displacement engine according to claim 1, characterized in that, The air inlet (11) is configured to close in response to the piston (2) being at top dead center and to be fully open in response to the piston (2) being at bottom dead center.

4. The two- or four-stroke variable displacement engine according to claim 3, characterized in that, Multiple air inlets (11) are provided and are distributed at intervals along the outline of the cylinder body (1).

5. The two- or four-stroke variable displacement engine according to claim 3, characterized in that, The air inlet (11) is constructed as a rectangular through hole.

6. The two- or four-stroke variable displacement engine according to claim 3, characterized in that, The first air intake (3) has two parts.

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