Methanol-diesel oil dual-fuel compression ignition engine capable of premixing outside cylinder
By designing mixing channels and air passages in an externally premixed methanol-diesel dual-fuel compression ignition engine, and combining them with a mode switching device, flexible switching of multiple fuel mixing modes can be achieved, solving the problem of fixed intake methods in existing technologies and improving the engine's environmental performance under complex operating conditions.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- GUANG DONG FEI TE DONG LI KE JI YOU XIAN GONG SI
- Filing Date
- 2026-03-02
- Publication Date
- 2026-05-15
AI Technical Summary
The existing methanol-diesel dual-fuel compression ignition engine injectors are fixedly installed in the intake manifold, and the intake method is fixed and cannot be flexibly adjusted, which makes it impossible to meet environmental protection requirements under complex operating conditions.
The design incorporates an external premixed methanol-diesel dual-fuel compression ignition engine, employing a mixing channel, a first intake port, and a second intake port. Combined with the distribution of methanol and diesel injectors, an external or internal fuel mixing mechanism is implemented through a mode switching device, supporting flexible switching between multiple operating modes.
It enables flexible switching based on engine operating conditions, avoids excessive reduction in combustion chamber temperature, reduces HC and CO emissions, meets stricter emission requirements, and improves the engine's environmental performance.
Smart Images
Figure CN122040403A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of engine technology, and more specifically to an off-cylinder premixed methanol-diesel dual-fuel compression ignition engine. Background Technology
[0002] The latent heat of vaporization of methanol is much greater than that of diesel fuel. This means that if methanol is directly injected into the cylinder for combustion at low engine temperatures, the combustion chamber temperature will drop further, increasing HC and CO emissions. Conversely, injecting methanol into the cylinder for combustion when the engine is warming up can lower the cylinder temperature, thus helping to reduce emissions. Emissions require the engine's fuel injection and intake systems to be able to flexibly switch operating modes to adapt to different engine operating conditions.
[0003] The fuel injectors of existing methanol-diesel dual-fuel compression ignition engines are fixedly installed in the intake manifold, and the intake method is fixed. During the operation of the engine, the fuel-air mixture can only be adjusted by adjusting the fuel injection amount. This limited adjustment method is gradually failing to meet the environmental protection requirements of methanol-diesel dual-fuel compression ignition engines under complex operating conditions. Summary of the Invention
[0004] The purpose of this invention is to overcome the above-mentioned shortcomings and provide an off-cylinder premixed methanol-diesel dual-fuel compression ignition engine.
[0005] To achieve the above objectives, the specific solution of the present invention is as follows: An externally premixed methanol-diesel dual-fuel compression ignition engine includes a cylinder block, a piston movably disposed within the cylinder block, and a cylinder head disposed at the end of the cylinder block; the cylinder head, piston, and cylinder block together enclose a combustion chamber; the cylinder head is provided with methanol injectors and diesel injectors; the cylinder head is provided with a mixing channel, a first intake passage, and a second intake passage; one end of the first intake passage is connected to the middle of the mixing channel; one end of the second intake passage is connected to one end of the mixing channel; the methanol injectors and diesel injectors are distributed on both sides of the first intake passage; the cylinder head is also provided with a first intake valve and a second intake valve for controlling the opening and closing of the mixing channel and the combustion chamber; the first intake valve and the second intake valve are distributed on both sides of the methanol injector and the diesel injector, and the second intake valve is disposed close to the methanol injector; The cylinder head is also provided with a mode switching device; the mode switching device is coupled to the first intake valve and the second intake valve.
[0006] Furthermore, the first intake valve and the second intake valve have the same structure, both including an intake valve, a first valve guide, a first spring, and a first top seat; the first valve guide is embedded in the cylinder head; one end of the intake valve moves through the first valve guide, the mixing passage, and the cylinder head and extends into the combustion chamber; the first top seat is located at the other end of the intake valve; the first spring is sleeved on the other end of the intake valve; both ends of the first spring abut against the first valve guide and the first top seat respectively; the first top seat is coupled to the mode switching device.
[0007] Furthermore, the first top seat has a first arc-shaped boss protruding on the side facing away from the intake valve.
[0008] Furthermore, the mode switching device of the present invention includes a switching seat disposed on the cylinder head, a driving member disposed on the switching seat, a top cup assembly rotatably disposed on the switching seat, and an intake camshaft rotatably disposed on the switching seat; the switching seat is provided with a central hole; the diameter of the central hole is greater than the distance between the first intake valve and the second intake valve. The drive unit is configured to drive the top cup assembly to rotate; the intake camshaft is located above the top cup assembly and coupled to the top cup assembly; the top cup assembly is configured to control the opening and closing of the first air passage and the second air passage, and to be coupled to the first intake valve and the second intake valve; the other end of the first air passage and the other end of the second air passage both pass through the switching seat.
[0009] Furthermore, the top cup assembly includes a turntable; the turntable has an arc-shaped hole near its edge; when the arc-shaped hole is connected to a first air passage, the first air passage is opened; when the arc-shaped hole is connected to a second air passage, the second air passage is opened.
[0010] Furthermore, the turntable is movably provided with four top cups; each top cup is connected to a second spring between itself and the side of the turntable facing away from the switching seat; two of the top cups are located at both ends of the same diameter direction of the central hole; the other two top cups are symmetrically distributed on both sides of the diameter direction of the two top cups; when the top cup rotates to below the cam structure of the intake camshaft, the top cup moves into contact with the cam structure of the intake camshaft and the first top seat.
[0011] Furthermore, the driving component of the present invention includes a motor and a gear; the gear is connected to the output end of the motor; a gear ring is provided on the outer circumference of the turntable; the gear ring meshes with the gear.
[0012] Furthermore, the cylinder head is provided with two exhaust valves; the mode switching device also includes an exhaust camshaft that is rotatably mounted on the switching seat; the exhaust camshaft is in movable contact with the two exhaust valves to control the connection between the combustion chamber and the outside.
[0013] Furthermore, each of the exhaust valve components includes an exhaust valve, a second air guide pipe, a second spring, and a second top seat; the second air guide pipe is embedded in the cylinder head; one end of the exhaust valve extends through the second air guide pipe and the cylinder head and then into the combustion chamber; the second top seat is located at the other end of the exhaust valve; the second spring is sleeved at the other end of the exhaust valve, and both ends abut against the second top seat and the second air guide pipe, respectively.
[0014] The beneficial effects of this invention are as follows: By setting up a mixing channel, a first air passage, and a second air passage, combined with the reasonable distribution of methanol and diesel injectors and different intake methods, this invention can achieve thorough mixing of fuel outside or inside the cylinder. This allows the engine to have multiple operating modes, such as dual-fuel external-cylinder mixing, dual-fuel internal-cylinder mixing, single methanol, and single diesel, which can be flexibly switched according to different engine operating conditions (such as low-temperature start-up, warm-up operation, etc.). In low-temperature engine conditions, a suitable mode can be selected to avoid excessive reduction in combustion chamber temperature leading to increased HC and CO emissions; in warm-up conditions, switching to a mode that reduces emissions is beneficial. The emission mode enables the engine to operate stably under complex conditions, overcoming the limitations of traditional methods that only adjust the fuel injection quantity to regulate the mixture state. This significantly improves the environmental performance of the methanol-diesel dual-fuel compression ignition engine and meets more stringent emission requirements. Attached Figure Description
[0015] Figure 1 This is a schematic diagram of the structure of the methanol-diesel dual-fuel compression ignition engine of the present invention; Figure 2 This is a cross-sectional schematic diagram of the methanol-diesel dual-fuel compression ignition engine of the present invention in dual-fuel external mixing mode; Figure 3 This is a cross-sectional schematic diagram of the methanol-diesel dual-fuel compression ignition engine of the present invention in the dual-fuel in-cylinder mixing mode; Figure 4 This is a cross-sectional schematic diagram of the methanol-diesel dual-fuel compression ignition engine of the present invention in single methanol mode; Figure 5 This is a cross-sectional schematic diagram of the methanol-diesel dual-fuel compression ignition engine of the present invention in single diesel mode; Figure 6 This is a schematic diagram of the hidden mode switching device for the methanol-diesel dual-fuel compression ignition engine of the present invention. Figure 7 This is a schematic diagram of the cylinder head structure of the present invention; Figure 8 This is a schematic diagram of the structure of the first or second intake valve of the present invention. Figure 9 This is a schematic diagram of the mode switching device of the present invention; Figure 10 This is a schematic diagram of the structure of the exhaust valve component of the present invention; Explanation of reference numerals in the attached drawings: 1. Cylinder block; 2. Piston; 3. Cylinder head; 31. Mixing passage; 32. First intake port; 33. Second intake port; 4. Combustion chamber; 51. Methanol injector; 52. Diesel injector; 61. First intake valve; 62. Second intake valve; 7. Mode switching device; 71. Switching seat; 721. Motor; 731. Turntable; 7311. Arc hole; 7312. Gear ring; 732. Top cup; 733. Second spring; 74. Intake camshaft; 75. Exhaust camshaft; 8. Exhaust valve; 81. Exhaust valve; 82. Second air guide pipe; 83. Second spring; 84. Second top seat; 841. Second arc boss; 101. Intake valve; 102. First valve guide; 103. First spring; 104. First top seat; 1041. First arc boss. Detailed Implementation
[0016] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments, but this is not to limit the scope of the invention to this.
[0017] like Figures 1 to 10 As shown, this embodiment of a pre-mixed methanol-diesel dual-fuel compression ignition engine includes a cylinder block 1, a piston 2 movably disposed within the cylinder block 1, and a cylinder head 3 disposed at the end of the cylinder block 1; the cylinder head 3, piston 2, and cylinder block 1 together enclose a combustion chamber 4; the cylinder head 3 is provided with a methanol injector 51 and a diesel injector 52; the cylinder head 3 is provided with a mixing channel 31, a first intake passage 32, and a second intake passage 33; one end of the first intake passage 32 is connected to the middle of the mixing channel 31; one end of the second intake passage 33 is connected to one end of the mixing channel 31; The methanol injector 51 and the diesel injector 52 are distributed on both sides of the first intake passage 32; the cylinder head 3 is also provided with a first intake valve 61 and a second intake valve 62 for controlling the opening and closing of the mixing passage 31 and the combustion chamber 4; the first intake valve 61 and the second intake valve 62 are distributed on both sides of the methanol injector 51 and the diesel injector 52, and the second intake valve 62 is located close to the methanol injector 51; the cylinder head 3 is also provided with a mode switching device 7; the mode switching device 7 is coupled to the first intake valve 61 and the second intake valve 62.
[0018] Specifically, the methanol-diesel dual-fuel compression ignition engine in this embodiment has multiple operating modes in actual use, which can be flexibly switched according to different engine operating conditions: If the first air passage 32 is closed and the second air passage 33 is opened, the mode switching device 7, in conjunction with the second intake valve 62, injects the corresponding fuels into the mixing passage 31 via the methanol injector 51 and the diesel injector 52. At this time, the airflow enters the mixing passage 31 through the second passage. The diesel and methanol, under the action of the airflow, are pre-mixed in the mixing passage 31 and then enter the combustion chamber 4 through the second intake valve 62 for combustion. At this time, the engine is in a dual-fuel external mixing mode. Figure 2 As shown, during the continuous reciprocating motion of the second intake valve 62, the mixed diesel and methanol are continuously fed into the combustion chamber 4. In this mode, the two fuels are fully mixed before entering the combustion chamber 4, which can achieve good results under suitable operating conditions such as engine warm-up and helps to improve combustion efficiency.
[0019] If the first air passage 32 is opened and the second air passage 33 is closed, the mode switching device 7 cooperates with the first intake valve 61 and the second intake valve 62. At this time, the airflow enters the mixing channel 31 and is split from the middle of the mixing channel 31 to both sides. The methanol injector 51 and the diesel injector 52 inject fuel into the mixing channel 31 respectively. Under the action of the airflow, diesel fuel enters the combustion chamber 4 through the first intake valve 61, and methanol enters the combustion chamber 4 through the second intake valve 62, causing the diesel and methanol to mix and burn in the combustion chamber 4. At this time, the engine is in a dual-fuel in-cylinder mixing mode. Figure 3 As shown, through the continuous reciprocating motion of the first intake valve 61 and the second intake valve 62, diesel and methanol are continuously fed into the combustion chamber 4 for mixing and combustion. This mode is suitable for operating conditions with specific requirements for fuel mixing timing and can adjust the mixing process according to actual conditions.
[0020] If the first air passage 32 is opened and the second air passage 33 is closed, the mode switching device 7 only cooperates with the second intake valve 62. At this time, the methanol injector 51 injects methanol into the mixing passage 31. Under the action of the airflow, the methanol enters the combustion chamber 4 through the second intake valve 62 for combustion. At this time, the engine is in single methanol mode. Figure 4 As shown, methanol is continuously supplied to the combustion chamber during the reciprocating motion of the second intake valve 62. This mode can be activated when methanol is required as a fuel, making full use of its properties.
[0021] If the first intake passage 32 is opened and the second intake passage 33 is closed, the mode switching device 7 only cooperates with the first intake valve 61. At this time, the diesel injector 52 injects diesel fuel into the mixing passage 31. Under the action of airflow, the diesel fuel enters the combustion chamber 4 through the first intake valve 61 and is burned. At this time, the engine is in single diesel mode. Figure 5As shown, the continuous reciprocating motion of the first intake valve 61 continuously delivers diesel fuel into the combustion chamber 4. This mode meets the operating requirements where only diesel fuel is needed, ensuring stable engine operation in specific scenarios.
[0022] This embodiment, by setting up a mixing channel 31, a first air passage 32, and a second air passage 33, along with the reasonable distribution of methanol injectors 51 and diesel injectors 52, and different intake methods, can achieve sufficient mixing of fuel outside or inside the cylinder. This allows the engine to have multiple operating modes, such as dual-fuel external-cylinder mixing, dual-fuel internal-cylinder mixing, single methanol, and single diesel, which can be flexibly switched according to different engine operating conditions (such as low-temperature start-up, warm-up operation, etc.). In low-temperature engine conditions, an appropriate mode can be selected to avoid excessive reduction in combustion chamber temperature leading to increased HC and CO emissions; in warm-up conditions, switching to a mode that reduces emissions is beneficial. The emission mode enables the engine to operate stably under complex conditions, overcoming the limitations of traditional methods that only adjust the fuel injection quantity to regulate the mixture state. This significantly improves the environmental performance of the methanol-diesel dual-fuel compression ignition engine and meets more stringent emission requirements.
[0023] like Figure 8 As shown, in some embodiments of the methanol-diesel dual-fuel compression ignition engine, the first intake valve 61 and the second intake valve 62 have the same structure, both including an intake valve 101, a first valve guide 102, a first spring 103, and a first top seat 104; the first valve guide 102 is embedded in the cylinder head 3, providing stable guidance for the movement of the intake valve 101; one end of the intake valve 101 extends through the first valve guide 102, the mixing passage 31, and the cylinder head 3 before entering the combustion chamber 4, and passes through itself... The motion control mixing channel 31 controls the opening and closing of the combustion chamber 4; the first top seat 104 is located at the other end of the intake valve 101, serving as a connection and force transmission function; the first spring 103 is sleeved on the other end of the intake valve 101; the two ends of the first spring 103 abut against the first valve guide 102 and the first top seat 104 respectively, and the elastic force of the spring is used to realize the reset of the intake valve 101; the first top seat 104 is coupled to the mode switching device 7, receives the control signal of the mode switching device 7, and drives the intake valve 101 to move.
[0024] like Figure 8 As shown, in some embodiments of the methanol-diesel dual-fuel compression ignition engine, the first top seat 104 has a first arc-shaped boss 1041 protruding on the side opposite to the intake valve 101. This configuration allows for smoother contact between the first top seat 104 and the intake camshaft 74, reducing wear during contact and improving the service life and operational stability of the components.
[0025] like Figures 2 to 5 , Figure 9 As shown, in some embodiments of the methanol-diesel dual-fuel compression ignition engine, the mode switching device 7 includes a switching seat 71 disposed on the cylinder head 3, a drive member disposed on the switching seat 71, a top cup 732 assembly rotatably disposed on the switching seat 71, and an intake camshaft 74 rotatably disposed on the switching seat 71; the switching seat 71 has a central hole; the diameter of the central hole is larger than the distance between the first intake valve 61 and the second intake valve 62, providing sufficient space for the movement of the top cup 732 assembly; the drive member is configured to drive the top cup 732 assembly to rotate. The intake camshaft 74 is located above the top cup 732 assembly and is coupled to the top cup 732 assembly. Its rotation drives the top cup 732 assembly to move. The top cup 732 assembly is configured to control the opening and closing of the first air passage 32 and the second air passage 33, and to be coupled to the first intake valve 61 and the second intake valve 62 to achieve comprehensive control of the intake mode and the intake valve. The other end of the first air passage 32 and the other end of the second air passage 33 both pass through the switching seat 71 to ensure the air passage is connected to the external airflow.
[0026] like Figures 2 to 5 , Figure 9 As shown, in some embodiments of the methanol-diesel dual-fuel compression ignition engine, the top cup 732 assembly includes a turntable 731. The turntable 731 has an arc-shaped hole 7311 near its edge. When the arc-shaped hole 7311 connects with the first air passage 32, the first air passage 32 opens; when the arc-shaped hole 7311 connects with the second air passage 33, the second air passage 33 opens. In this embodiment, the rotation of the turntable 731 enables the connection between the arc-shaped hole 7311 and different air passages, thereby controlling the opening and closing of the air passages. The operation is simple and reliable, achieving synchronous linkage control between the air passages and the intake valve 101.
[0027] like Figures 2 to 5 , Figure 9 As shown, in some embodiments of the methanol-diesel dual-fuel compression ignition engine, the turntable 731 is movably fitted with four top cups 732; each top cup 732 is connected to a second spring 83733 between it and the side of the turntable 731 facing away from the switching seat 71; two of the top cups 732 are located at both ends of the same diameter direction of the central hole; the other two top cups 732 are symmetrically distributed on both sides of the diameter direction of the two top cups 732; when the top cup 732 rotates to below the cam structure of the intake camshaft 74, the top cup 732 moves into contact with the cam structure of the intake camshaft 74 and the first top seat 104. Through the above arrangement, the top cup 732, under the action of the intake camshaft 74, can push the first top seat 104, thereby controlling the opening and closing of the intake valve 101. The second spring 83733 ensures that the top cup 732 can be reset in time when not under the force of the cam structure, ensuring the normal operation of the intake valve components.
[0028] like Figure 9 As shown, in some embodiments of the methanol-diesel dual-fuel compression ignition engine, the driving components include a motor 721 and a gear; the gear is connected to the output end of the motor 721; a gear ring 7312 is provided on the outer circumference of the turntable 731; the gear ring 7312 meshes with the gear. In this embodiment, the motor 721 drives the turntable 731 to rotate through the meshing of the gear and the gear ring 7312. This driving method has high transmission efficiency and precise control, and can accurately realize the rotational positioning of the top cup 732 component, ensuring the accuracy of mode switching.
[0029] Specifically, such as Figure 2 As shown, if the engine needs to be placed in dual-fuel external hybrid mode, the motor 721 drives the gear to rotate. The gear, in conjunction with the gear ring 7312, drives the turntable 731 to rotate, so that the arc hole 7311 aligns with the position of the second air passage 33. At this time, the second air passage 33 opens, and the turntable 731 closes the first air passage 32. Simultaneously, the turntable 731 drives each top cup 732 to rotate, so that the corresponding top cup 732 rotates to above the first top seat 104 of the second intake valve component 62. At this time, the corresponding top cup 732 is squeezed by the cam structure of the intake camshaft 74. This allows the intake valve 101 of the second intake valve 62 to connect the mixing channel 31 with the combustion chamber 4. The methanol injector 51 and the diesel injector 52 inject their respective fuels into the mixing channel 31. The airflow from one end of the mixing channel 31 towards the second intake valve 62 drives the methanol and diesel to flow, thus ensuring that they are fully mixed in the mixing channel 31 beforehand. After mixing, the methanol and diesel enter the combustion chamber 4 through the intake valve 101 of the second intake valve 62 for combustion. In this way, during the continuous reciprocating motion of the second intake valve 62, the mixed methanol and diesel are continuously fed into the combustion chamber 4.
[0030] like Figure 3As shown, if the engine needs to be in dual-fuel in-cylinder mixing mode, the turntable 731 is rotated, causing the first intake passage 32 to open and the second intake passage 33 to close. The two top cups 732, located in the same diameter direction, rotate to above the first top seat 104 of the first intake valve 61 and the first top seat 104 of the second intake valve 62, respectively. At this time, under the squeezing action of the cam structure corresponding to the intake camshaft 74, the intake valves 101 of the first and second intake valves 61 connect the mixing passage 31 to the combustion chamber 4, respectively. The methanol injector 5... The methanol and diesel injectors 52 inject their respective fuels into the mixing channel 31. Since the first air passage 32 is connected to the middle of the mixing channel 31, and the methanol injector 51 and the diesel injector 52 are distributed on both sides of the first air passage 32, a portion of the airflow carries diesel fuel through the intake valve 101 of the first intake valve 61 into the combustion chamber 4, and another portion of the airflow carries methanol through the intake valve 101 of the second intake valve 62 into the combustion chamber 4, so that diesel fuel and methanol are mixed and burned in the combustion chamber 4. Thus, under the reciprocating motion of the intake valve 101 of the first intake valve 61 and the intake valve 101 of the second intake valve 62, diesel fuel and methanol are continuously sent into the combustion chamber 4.
[0031] like Figure 4 As shown, if the engine needs to be placed in methanol-only mode, the turntable 731 is rotated to open the first air passage 32 and close the second air passage 33. The turntable 731 drives the corresponding top cup 732 to rotate above the first top seat 104 of the second intake valve 62. At this time, the corresponding top cup 732 is squeezed by the cam structure of the intake camshaft 74, causing the intake valve 101 of the second intake valve 62 to connect the mixing passage 31 with the combustion chamber 4. The methanol injector 51 injects methanol into the mixing passage 31. Under the action of airflow, the methanol enters the combustion chamber 4 through the intake valve 101 of the second intake valve 62 and is burned. In this way, the intake valve 101 of the second intake valve 62 continuously sends methanol into the combustion chamber 4.
[0032] like Figure 5As shown, if the engine needs to be placed in diesel mode, the turntable 731 is rotated to open the first air passage 32 and close the second air passage 33. The turntable 731 drives the corresponding top cup 732 to rotate above the first top seat 104 of the first intake valve 61. At this time, the corresponding top cup 732 is squeezed by the cam structure of the intake camshaft 74, so that the intake valve 101 of the first intake valve 61 connects the mixing passage 31 with the combustion chamber 4. At this time, the diesel injector 52 injects diesel into the mixing passage 31. Under the action of airflow, the diesel enters the combustion chamber 4 through the intake valve 101 of the first intake valve 61 and is burned. In this way, the intake valve 101 of the first intake valve 61 continuously sends methanol into the combustion chamber 4.
[0033] like Figures 2 to 6 , Figure 10 As shown, in some embodiments of the methanol-diesel dual-fuel compression ignition engine, the cylinder head 3 is further provided with two exhaust valves 8; the mode switching device 7 also includes an exhaust camshaft 75 rotatably mounted on the switching seat 71; the exhaust camshaft 75 movably abuts against the two exhaust valves 8 to control the opening and closing of the combustion chamber 4 with the outside. In this embodiment, the exhaust valves 8 cooperate with the exhaust camshaft 75 to achieve timely discharge of exhaust gas from the combustion chamber 4, ensuring normal engine operation and improving the overall performance of the engine.
[0034] like Figure 10 As shown, in some embodiments of the methanol-diesel dual-fuel compression ignition engine, each exhaust valve 8 includes an exhaust valve 81, a second air guide pipe 82, a second spring 83733, and a second top seat 84. The second air guide pipe 82 is embedded in the cylinder head 3 to guide the movement of the exhaust valve 81. One end of the exhaust valve 81 extends through the second air guide pipe 82 and the cylinder head 3 and then into the combustion chamber 4, controlling the opening and closing of the exhaust passage between the combustion chamber 4 and the outside through its own movement. The second top seat 84 is located at the other end of the exhaust valve 81 to receive the force of the exhaust camshaft 75. The second spring 83733 is sleeved on the other end of the exhaust valve 81, and both ends abut against the second top seat 84 and the second air guide pipe 82 respectively, using the spring force to reset the exhaust valve 81 and ensure the reliable operation of the exhaust valve 8.
[0035] like Figure 10 As shown, in some embodiments of the methanol-diesel dual-fuel compression ignition engine, the second top seat 84 has a second arc-shaped boss 841 protruding from the side facing away from the exhaust valve 81. This configuration allows for smoother contact between the second top seat 84 and the exhaust camshaft 75, reducing wear during contact and improving the service life and operational stability of the components.
[0036] The above description is only a preferred embodiment of the present invention. Therefore, any equivalent changes or modifications made to the structure, features and principles described in the claims of this patent application are included within the protection scope of this patent application.
Claims
1. An off-cylinder premixed methanol-diesel dual-fuel compression ignition engine, characterized in that, The system includes a cylinder block, a piston movable within the cylinder block, and a cylinder head located at the end of the cylinder block. The cylinder head, piston, and cylinder block together enclose a combustion chamber. The cylinder head is equipped with methanol injectors and diesel injectors. The cylinder head contains a mixing channel, a first intake passage, and a second intake passage. One end of the first intake passage is connected to the middle of the mixing channel. One end of the second intake passage is connected to one end of the mixing channel. The methanol injectors and diesel injectors are distributed on both sides of the first intake passage. The cylinder head also has a first intake valve and a second intake valve for controlling the opening and closing of the mixing channel and the combustion chamber. The first intake valve and the second intake valve are distributed on both sides of the methanol injector and the diesel injector, with the second intake valve positioned closer to the methanol injector. The cylinder head is also provided with a mode switching device; the mode switching device is coupled to the first intake valve and the second intake valve.
2. The methanol-diesel dual-fuel compression ignition engine with external premixing according to claim 1, characterized in that, The first and second intake valve components have the same structure, both including an intake valve, a first valve guide, a first spring, and a first top seat; the first valve guide is embedded in the cylinder head; one end of the intake valve moves through the first valve guide, the mixing passage, and the cylinder head and extends into the combustion chamber; the first top seat is located at the other end of the intake valve; the first spring is sleeved on the other end of the intake valve; both ends of the first spring abut against the first valve guide and the first top seat respectively; the first top seat is coupled to the mode switching device.
3. The methanol-diesel dual-fuel compression ignition engine with external premixing according to claim 2, characterized in that, The first top seat has a first arc-shaped boss protruding on the side facing away from the intake valve.
4. The methanol-diesel dual-fuel compression ignition engine with external premixing according to claim 2, characterized in that, The mode switching device includes a switching seat on the cylinder head, a driving component on the switching seat, a top cup assembly rotatably mounted on the switching seat, and an intake camshaft rotatably mounted on the switching seat; the switching seat has a central hole; the diameter of the central hole is greater than the distance between the first intake valve and the second intake valve. The drive unit is configured to drive the top cup assembly to rotate; the intake camshaft is located above the top cup assembly and coupled to the top cup assembly; the top cup assembly is configured to control the opening and closing of the first air passage and the second air passage, and to be coupled to the first intake valve and the second intake valve; the other end of the first air passage and the other end of the second air passage both pass through the switching seat.
5. The methanol-diesel dual-fuel compression ignition engine with external premixing according to claim 4, characterized in that, The top cup assembly includes a turntable; the turntable has an arc-shaped hole near its edge; when the arc-shaped hole is connected to a first air passage, the first air passage is opened; when the arc-shaped hole is connected to a second air passage, the second air passage is opened.
6. The methanol-diesel dual-fuel compression ignition engine with external premixing according to claim 5, characterized in that, The turntable is movably fitted with four top cups; each top cup is connected to a second spring between itself and the side of the turntable facing away from the switching seat; two of the top cups are located at both ends of the same diameter direction of the central hole; the other two top cups are symmetrically distributed on both sides of the diameter direction of the two top cups; when the top cup rotates to below the cam structure of the intake camshaft, the top cup moves into contact with the cam structure of the intake camshaft and the first top seat.
7. The methanol-diesel dual-fuel compression ignition engine with external premixing according to claim 5, characterized in that, The driving component includes a motor and a gear; the gear is connected to the output end of the motor; the outer circumference of the turntable is provided with a gear ring; the gear ring meshes with the gear.
8. The methanol-diesel dual-fuel compression ignition engine with external premixing according to claim 4, characterized in that, The cylinder head is also provided with two exhaust valves; the mode switching device also includes an exhaust camshaft that is rotatably mounted on the switching seat; the exhaust camshaft is in contact with the two exhaust valves to control the connection between the combustion chamber and the outside.
9. The methanol-diesel dual-fuel compression ignition engine with external premixing according to claim 8, characterized in that, Each of the exhaust valve components includes an exhaust valve, a second air guide pipe, a second spring, and a second top seat; the second air guide pipe is embedded in the cylinder head; one end of the exhaust valve extends through the second air guide pipe and the cylinder head and into the combustion chamber; the second top seat is located at the other end of the exhaust valve; the second spring is sleeved at the other end of the exhaust valve, and both ends abut against the second top seat and the second air guide pipe, respectively.