Variable-exhaust high-power two-stroke industrial engine

Abstract

The invention relates to a variable exhaust high-power two-stroke industrial engine, and belongs to the technical field of internal combustion engines. The engine comprises an engine body, an exhaust assembly and an air inlet control unit. The air inlet control unit is composed of a reed valve, an air filter, an electronic control unit and a reed pipe. The reed valves are hinged through an adjustable pin shaft, and a closed-loop feedback control loop is formed by combining non-contact detection of the reed pipes; the electronic control unit dynamically adjusts the opening angle and frequency of the reed valve through a fuzzy algorithm based on the rotating speed signal and the accelerator opening degree, and the scavenging efficiency is optimized; a rotatable baffle driven by a stepping motor is arranged in a three-way catalytic assembly of the exhaust assembly, the opening degree of the rotatable baffle is linked with an air inflow signal, and dynamic matching of exhaust back pressure and catalytic temperature is achieved. The problems that a reed valve of a traditional two-stroke engine is prone to fatigue, the catalytic efficiency is low, and emission exceeds the standard are solved, and the combustion efficiency and the environmental protection performance are remarkably improved.

Description

Technical Field

[0001] The invention relates to the technical field of internal combustion engines, in particular to a high-power two-stroke industrial engine with variable exhaust. Background Art

[0002] A two-stroke engine is an internal combustion engine that can complete a complete power cycle through the reciprocating motion of a single piston. Its working principle can be divided into two strokes: when the piston moves upward, the exhaust gas is discharged and the fresh mixture is compressed at the same time; when the piston moves downward, the mixture is burned, expanded and partially exhausted. This type of engine is widely used in many fields. Its unique intake system design is: the intake port opened on the crankcase allows the fuel and air to be pre-mixed in the crankcase and form a certain pressure, and then the pre-mixed gas is introduced into the cylinder through the scavenging port to participate in combustion. Although this pre-compression structure can improve the charging efficiency, it will inevitably cause the oil in the crankcase to participate in the combustion, thereby generating harmful exhaust emissions containing incompletely burned substances, forming an environmental pollution problem.

[0003] After extensive searching, the publication number is CN116122954A, which discloses an improved two-stroke engine, including an engine body, a crankcase, a piston and a piston connecting rod, the top of the crankcase is fixedly connected to a cylinder barrel, the top of the cylinder barrel is fixedly connected to a cylinder head, the piston is slidably connected in the cylinder barrel up and down, an air intake is provided on the side wall of the cylinder barrel and corresponds to the low position of the piston downward stroke, the air intake is connected to an air intake valve, the air intake is connected to an external supercharger, an exhaust port is provided on the cylinder head, the exhaust port is connected to an exhaust valve, the intake valve and the exhaust valve are controlled to open and close synchronously using a valve mechanism, and a spark plug for igniting the mixed oil and gas in the cylinder barrel is fixedly connected to the cylinder head.

[0004] However, the reed valve of the above technology adopts a fixed pin shaft structure and does not integrate a dynamic feedback mechanism, resulting in a high risk of metal fatigue and limited control accuracy. At the same time, its solenoid valve control is only for the intake system and is not linked with the exhaust component, resulting in insufficient efficiency of the three-way catalytic converter under transient conditions. Therefore, a high-power two-stroke industrial engine with variable exhaust is proposed to solve the above problems. Summary of the invention

[0005] The object of the present invention is to provide a high-power two-stroke industrial engine with variable exhaust, which can effectively solve the problems in the background technology.

[0006] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: A high-power two-stroke industrial engine with variable exhaust, comprising: an engine body, which is composed of a crankcase and a piston cylinder body connected to the crankshaft; an exhaust assembly, which is composed of an intake pipe, a three-way catalytic assembly and an exhaust pipe connected in sequence; The first support frame and the second support frame are respectively arranged on both sides of the bottom of the crankcase, and an air intake groove connected to an external air source is opened on the front of the crankcase; the piston cylinder and the crankshaft in the crankcase form a linkage mechanism; the crankcase is equipped with an air intake control unit at the air intake groove; The air intake control unit comprises: a reed valve, which is composed of a valve seat and at least two elastic metal reeds which are stacked and distributed, wherein the reed is hinged to the top of the valve seat through an adjustable pin shaft, and its arc-shaped free end forms a dynamically opened and closed wedge-shaped airflow channel with the bottom of the valve seat; an air filter, which is vertically arranged at the air intake end of the reed valve with a multi-layer pleated filter structure; an electronic control unit, which has a microprocessor and a drive circuit linked to the engine, and is connected to a Hall speed sensor arranged at the crankshaft end through a bus; a reed switch, which is embedded in the periphery of the reed valve body with a magnetic shielding packaging structure, and the contact switch of the reed switch forms a closed-loop feedback control circuit with the electronic control unit for real-time adjustment of the opening angle of the reed valve (32); The electronic control unit generates a driving signal with adjustable duty cycle through a fuzzy algorithm based on the real-time collected speed pulse signal and throttle opening analog quantity, and accurately adjusts the opening angle and frequency of the reed valve through the electromagnetic actuation of the reed switch to achieve dynamic optimization of the piston cylinder scavenging efficiency. At the same time, the back pressure valve opening of the exhaust component is synchronously controlled through the air pressure feedback mechanism.

[0007] Preferably, the engine body further comprises a transmission assembly mounted on one side of the crankcase, and the transmission assembly forms a power transmission connection with the crankshaft in the crankcase via a spline coupling.

[0008] When the above technical solution is adopted, the transmission assembly is connected to the crankshaft in the crankcase through a spline coupling, so as to achieve high efficiency and stability of power transmission. The rigid connection design of the spline coupling reduces the vibration loss of the traditional flexible coupling during high-speed operation. During the operation of the traditional flexible coupling, due to its certain elasticity, elastic deformation will inevitably occur during high-speed rotation. This deformation will cause vibration, which not only consumes a lot of energy, but also causes the coupling itself and the components connected to it to be subjected to additional alternating stress. When in this state for a long time, the components are prone to fatigue wear, reducing the service life of the equipment. The spline coupling, with its rigid connection characteristics, greatly reduces the possibility of vibration. In actual industrial application scenarios, such as large mining machinery, the engine has a high speed and a large load when driving the equipment. If a traditional flexible coupling is used, the vibration generated under high-speed operation will not only reduce the power transmission efficiency, but also may cause the mechanical structure to loosen, affecting the normal operation of the equipment. The application of the spline coupling effectively avoids these problems and ensures that the power can be stably and efficiently transmitted from the crankshaft to the transmission assembly.

[0009] Preferably, the reed of the reed valve is made of a highly elastic titanium alloy, the surface of the reed is provided with a titanium nitride coating, and the free end of the reed is chamfered to form a smooth transition edge.

[0010] When the above technical solution is adopted, the reed of the reed valve is made of high-elastic titanium alloy, the surface is coated with titanium nitride coating and the free end is chamfered, which achieves a significant improvement in the fatigue resistance and wear resistance of the reed. Titanium alloy has a unique crystal structure, which gives it good elasticity and high strength. At the microscopic level, the atoms of titanium alloy are arranged tightly and orderly, giving it excellent resistance to deformation. Compared with traditional steel reeds, high-elastic titanium alloy reeds perform better when subjected to high-frequency opening and closing actions. During the operation of the engine, the reed valve needs to be opened and closed frequently to control the intake volume. After a certain number of high-frequency opening and closing, traditional steel reeds are very likely to crack or even break due to fatigue stress. Through experimental test comparison, under the same working time and opening and closing frequency, the probability of fatigue cracks in traditional steel reeds is much higher than that of high-elastic titanium alloy reeds. With its excellent fatigue resistance, high-elastic titanium alloy reeds greatly extend the service life of reed valves, reduce engine failures caused by reed damage, and reduce maintenance costs.

[0011] Preferably, the magnetic induction element inside the reed switch detects the rotation angle change of the pin shaft in a non-contact manner, generates a reed opening feedback signal in real time and transmits it to the electronic control unit.

[0012] When the above technical solution is adopted, the non-contact detection of the pin rotation angle change of the reed switch realizes the real-time and accurate feedback of the reed opening signal. The magnetic sensing element inside the reed switch adopts advanced non-contact detection technology, which can keenly sense the change of the pin rotation angle. During the operation of the engine, as the reed valve opens and closes, the pin will rotate accordingly. The magnetic sensing element in the reed switch can quickly capture this change and generate a reed opening feedback signal in real time.

[0013] Preferably, a rotatable baffle is provided inside the three-way catalytic component, and the baffle is opened by a stepper motor driving a rotating shaft. The stepper motor is connected to an electronic control unit signal, and the baffle opening is associated with an intake volume signal received by the electronic control unit.

[0014] When the above technical solution is adopted, the dynamic matching of exhaust back pressure and catalytic temperature is achieved through the signal linkage between the rotatable baffle inside the three-way catalytic component and the electronic control unit. A rotatable baffle is provided inside the three-way catalytic component, and the baffle is driven by a stepper motor to adjust the opening of the rotating shaft. The stepper motor is connected to the electronic control unit signal, and the baffle opening is associated with the intake volume signal received by the electronic control unit.

[0015] In the present invention, the electronic control unit accurately controls the stepper motor to adjust the baffle opening according to the real-time intake signal. When the intake increases, the exhaust volume increases accordingly, and the electronic control unit controls the baffle opening to increase, so that the exhaust is smoother and the exhaust back pressure is reduced. At the same time, it is ensured that there is enough gas flow in the catalyst to maintain the appropriate temperature and optimize the catalytic reaction conditions. From the principle of catalytic reaction kinetics, it can be seen that the appropriate exhaust back pressure and gas flow can promote the more complete conversion of harmful gases into harmless substances in the three-way catalytic component.

[0016] Preferably, it also includes a fuel and lubricating oil supply assembly, which is composed of an integrated fuel and lubricating oil box, a fuel pump and a lubricating oil pump. A cover body is provided on the top of the piston cylinder body, and the cover body adopts an integrated casting structure. A fuel supply port connected to the fuel pump and a spark plug connected to the ignition system are provided on the top of the cover body.

[0017] When the above technical solution is adopted, the coordinated optimization of fuel supply and sealing performance is achieved through the design of an integrated fuel and lubricant box and an integrated cast cover. The integrated casting structure reduces the risk of leakage in the traditional split cover. In the traditional split cover design, since the various components need to be assembled through bolts or other connectors, during long-term use, the connectors may loosen due to factors such as engine vibration and temperature changes, resulting in poor sealing and fuel or lubricant leakage. The integrated cast cover is an integral structure, and there is no problem of loose connectors, which greatly improves the sealing performance. For example, in some harsh working environments, such as high temperature and high vibration industrial sites, the integrated cast cover can effectively prevent fuel and lubricant leakage, ensure the normal operation of the engine, and reduce safety hazards and environmental pollution caused by leakage.

[0018] Preferably, the fuel pump comprises a main pump body and an auxiliary pump body arranged in parallel, the main pump body supplies fuel to the fuel supply port through a first fuel discharge pipe, and the auxiliary pump body draws fuel from a fuel and lubricating oil integrated tank through a second fuel discharge pipe.

[0019] When the above technical solution is adopted, the redundancy and stability of the fuel supply system are achieved by setting the fuel pump with a main pump body and an auxiliary pump body in parallel. The main pump body is responsible for high-pressure fuel supply, and the auxiliary pump body realizes fuel circulation in the fuel tank through the second fuel discharge pipe to avoid oil circuit air blockage. When the engine is started, the auxiliary pump body circulates fuel in advance, providing sufficient fuel preparation for engine start-up, ensuring that the engine can start smoothly. During the operation of the engine, even if some situations that may cause air blockage are encountered, such as long-term climbing causing the oil temperature to rise, the auxiliary pump body can circulate fuel to ensure the continuity of fuel supply, ensure the stability of fuel supply under different working conditions, and improve the reliability and adaptability of the engine.

[0020] Preferably, an independent fuel outlet and fuel inlet are provided above the side wall of the integrated fuel and lubricating oil tank, and a lubricating oil inlet and a lubricating oil outlet are provided at the bottom of the side wall of the integrated fuel and lubricating oil tank. The lubricating oil pump draws the lubricating oil from the integrated fuel and lubricating oil tank through the lubricating oil discharge pipe and transports it to the crankcase.

[0021] When the above technical solution is adopted, the independent oil port partition design of the integrated fuel and lubricating oil box realizes the efficient management of fuel and lubricating oil. The separate setting of fuel outlet and lubricating oil outlet avoids oil mixing and contamination. The lubricating oil pump accurately delivers lubricating oil through an independent discharge pipe, reducing the combustion loss of engine oil in the crankcase.

[0022] Preferably, a labyrinth oil-gas separator is provided in the crankcase, and a multi-stage staggered guide plate and a centrifugal impeller are provided inside the oil-gas separator. The separated lubricating oil flows back to the fuel and lubricating oil integrated tank through the lubricating oil drain pipe.

[0023] When the above technical solution is adopted, the labyrinth oil-gas separator is set in the crankcase to achieve effective separation of lubricating oil and exhaust gas. The combination design of multi-stage staggered guide plate and centrifugal impeller greatly improves the oil-gas separation efficiency through the dual separation mechanism of inertial collision and centrifugal force, and reduces the pollution and waste caused by the discharge of lubricating oil with exhaust gas.

[0024] Preferably, the electronic control unit has a built-in multi-channel data acquisition module, which transmits intake air flow, exhaust temperature and lubricating oil pressure data to an external diagnostic terminal via a CAN bus protocol, and triggers an alarm signal when the parameters are abnormal.

[0025] When the above technical solution is adopted, the multi-channel data acquisition module of the electronic control unit communicates with the CAN bus protocol to realize real-time monitoring and diagnosis of engine operating parameters. Abnormal data of intake flow, exhaust temperature and lubricating oil pressure can trigger alarm signals, provide a basis for preventive maintenance, and improve system reliability and fault response speed.

[0026] The multi-channel data acquisition module built into the electronic control unit can collect key data such as intake flow, exhaust temperature and lubricating oil pressure in real time and accurately. The intake flow reflects the working status of the engine intake system. When the intake flow is abnormal, it may mean that the air filter is blocked, the intake pipe leaks or the intake valve is faulty. Exhaust temperature is an important indicator of the engine combustion process and the working condition of the exhaust system. Excessive exhaust temperature may indicate insufficient engine combustion, three-way catalytic converter failure or cooling system abnormality. Lubricating oil pressure is directly related to the lubrication effect of various engine components. Too low pressure may cause increased wear of components, and too high pressure may indicate problems such as blockage in the lubrication system.

[0027] Compared with the prior art, the present invention has the following beneficial effects: The present invention achieves the effect of dynamically adjusting the intake volume to optimize the scavenging efficiency by arranging a closed-loop feedback control circuit of an adjustable pin-hinged reed valve and a reed switch.

[0028] The reed valve adopts an adjustable pin-jointed design, combined with non-contact angle detection of the reed switch, eliminates external electromagnetic interference through magnetic shielding packaging, generates a reed opening signal in real time and feeds it back to the electronic control unit to form a precise closed-loop control loop. The reed material is made of high-elastic titanium alloy, coated with titanium nitride coating on the surface, and combined with the chamfering and smoothing treatment of the free end, its fatigue resistance and long-term working stability are significantly improved. Based on the real-time collected speed pulse signal and throttle opening analog quantity, the electronic control unit dynamically matches the opening angle of the reed valve with the engine operating requirements through a fuzzy algorithm, thereby reducing the fluctuation range of the scavenging efficiency and reducing the fuel consumption rate. This solution fundamentally solves the technical problems of intake response lag, easy fatigue fracture of the reed valve and unstable scavenging efficiency caused by open-loop control in the existing technology, and realizes the intelligent dynamic optimization of the intake system.

[0029] The present invention achieves the effect of coordinated optimization of emission control and intake volume by providing a rotatable baffle of the three-way catalytic component and a feedforward-feedback linkage mechanism with an electronic control unit.

[0030] The rotatable baffle inside the three-way catalytic component is driven by a stepper motor, and its opening is linearly correlated with the real-time intake signal received by the electronic control unit, thereby achieving dynamic matching of exhaust back pressure and catalyst temperature. The electronic control unit generates a drive signal based on the speed pulse signal and the throttle opening analog value, and synchronously adjusts the reed valve opening and the baffle opening, so that the intake volume, exhaust back pressure and catalytic efficiency form a feedforward-feedback collaborative control loop. Through the linkage optimization of intake and exhaust, the catalyst can quickly stabilize to the efficient operating temperature range under transient conditions, significantly reducing the emission of incompletely burned substances. This design completely solves the problems of insufficient catalytic efficiency and excessive emissions caused by independent control of the intake system and exhaust components in the existing technology, and achieves a dual improvement in power output and environmental performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a schematic diagram of the main structure of the present invention; Figure 2 It is a rear view structural schematic diagram of the present invention; Figure 3 It is a schematic diagram of the main structure of the engine of the present invention; Figure 4 It is a schematic diagram of the exhaust assembly structure of the present invention; Figure 5 It is a schematic diagram of the structure of the air intake control unit of the present invention; Figure 6 It is a schematic diagram of the structure of the fuel and lubricating oil supply assembly of the present invention; Figure 7 It is a flow chart of the electronic control unit of the present invention for dynamically optimizing the control of intake and exhaust; Figure 8 The present invention is a flow chart for realizing efficient catalysis and emission reduction of the electronically controlled exhaust component.

[0032] In the figure: 1. engine body; 11. crankcase; 111. first support frame; 112. second support frame; 113. intake groove; 12. transmission assembly; 13. piston cylinder; 14. cover body; 141. fuel supply port; 142. spark plug; 2. exhaust assembly; 21. intake pipe; 22. three-way catalytic assembly; 23. outlet pipe; 3. intake control unit; 31. air filter; 32. reed valve; 33. electronic control unit; 34. reed switch; 4. fuel and lubricating oil supply assembly; 41. fuel and lubricating oil integrated box; 411. fuel outlet; 412. fuel inlet; 413. lubricating oil inlet; 414. lubricating oil outlet; 42. fuel pump; 421. first fuel drain pipe; 422. second fuel drain pipe; 43. lubricating oil pump; 431. lubricating oil drain pipe. DETAILED DESCRIPTION

[0033] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0034] Embodiment 1: Optimization design of air intake control unit This embodiment focuses on the intake control unit 3, referring to Figure 3 , Figure 5 and Figure 7 , aiming to deeply optimize its performance.

[0035] An air intake groove 113 connected to an external air source is provided on the front side of the crankcase 11 of the engine body 1, and the air intake control unit 3 is installed therein.

[0036] The air filter 31 in the intake control unit 3 adopts a multi-layer pleated filter structure and is vertically arranged at the intake end of the reed valve 32. From the perspective of material science, the multi-layer pleated filter increases the filtering area, can more effectively intercept impurities in the air, prevent them from entering the engine, and protect engine parts from wear. Its pleated structure design is based on the mathematical principle of increasing surface area, greatly improving the filtering efficiency in a limited space, reducing the damage of impurities to the subsequent intake system and internal components of the engine, and ensuring the stable operation of the engine.

[0037] The reed valve 32 is composed of a valve seat and at least two elastic metal reeds stacked and distributed. The reed is hinged to the top of the valve seat through an adjustable pin shaft, and its arc-shaped free end forms a dynamically opened and closed wedge-shaped airflow channel with the bottom of the valve seat. The reed is made of highly elastic titanium alloy, and the crystal structure of the titanium alloy gives it good elasticity and high strength. In the field of materials science, the atomic arrangement inside the titanium alloy gives it excellent fatigue resistance, and it can withstand a higher frequency of opening and closing actions compared to traditional steel. The surface-coated nano-scale composite wear-resistant coating uses the small size effect and high surface activity of nano-materials to reduce the friction coefficient between the gas and the reed surface and reduce wear. From a microscopic perspective, the nano-coating fills the tiny defects on the surface of the titanium alloy and enhances the surface hardness and wear resistance. The free end of the reed is chamfered, and according to the principles of fluid mechanics, it can effectively reduce the turbulence phenomenon when the airflow passes through, reduce the intake resistance, improve the intake efficiency, make the air entering the crankcase 11 smoother, and provide sufficient oxygen for the subsequent combustion process.

[0038] The electronic control unit 33 has a built-in microprocessor and a drive circuit that are linked to the engine. It is connected to the Hall speed sensor arranged at the crankshaft end through a bus to obtain the engine speed pulse signal in real time and receive the throttle opening analog value at the same time. The reed switch 34 is embedded in the outer periphery of the valve body of the reed valve 32 in a magnetic shielding packaging structure. The magnetic sensing element inside it detects the rotation angle change of the pin shaft in a non-contact manner, generates a reed opening feedback signal in real time and transmits it to the electronic control unit 33, and the two form a closed-loop control circuit. Based on the fuzzy algorithm, the electronic control unit 33 comprehensively processes these real-time signals and generates a driving signal with adjustable duty cycle. The opening angle and frequency of the reed valve 32 are accurately adjusted through the electromagnetic actuation of the reed switch 34.

[0039] The specific rules of the fuzzy algorithm are as follows: Based on the experience and theoretical knowledge of engine operation, the following fuzzy rule table is formulated: When the engine is at "low speed" and the throttle opening is "small opening", in order to ensure stable combustion, a small intake volume is required. At this time, the reed valve opening angle should be "small" and the opening frequency should be "low". If it is at "low speed" but the throttle opening is "medium opening", the intake volume is appropriately increased, and the reed valve opening angle is adjusted to "medium" and the opening frequency is "medium". When "low speed" and "large opening" are combined, in order to meet the power demand, the intake volume is greatly increased, and the reed valve opening angle is "large" and the opening frequency is "high". Under "medium speed", "small opening" corresponds to the reed valve opening angle of "medium" and the opening frequency of "low"; when "medium opening", the opening angle is "medium" and the opening frequency is "medium"; when "large opening", the opening angle is "large" and the opening frequency is "high". In the "high speed" state, the "small opening" makes the opening angle of the reed valve "medium" and the opening frequency "medium"; when it is "medium opening", the opening angle is "large" and the opening frequency is "high"; when it is "large opening", the opening angle is "large" and the opening frequency is "high", but considering factors such as the intake resistance at high speed, the adjustment range of the opening angle and frequency needs to be carefully controlled.

[0040] Fuzzy reasoning and defuzzification: After receiving the real-time speed and throttle opening signals, the electronic control unit 33 determines the fuzzy subset to which it belongs and performs fuzzy reasoning according to the above rules. For example, the current speed is 2000r / min ("medium speed"), and the throttle opening is 40% ("medium opening"). According to the rules, it is inferred that the opening angle of the reed valve should be "medium" and the opening frequency should be "medium". After that, the defuzzification method such as the center of gravity method is used to convert the fuzzy reasoning result into an accurate control quantity, that is, to generate a driving signal with adjustable duty cycle, accurately adjust the opening angle and frequency of the reed valve 32, and then dynamically optimize the scavenging efficiency of the piston cylinder 13, to ensure that the engine can obtain the appropriate intake volume under different working conditions, improve combustion efficiency, and reduce fuel consumption.

[0041] Embodiment 2: Coordinated control of exhaust components and intake This embodiment focuses on the cooperative working mechanism between the exhaust assembly 2 and the intake system. Figure 4 , Figure 5 and Figure 8 .

[0042] The exhaust component 2 is composed of an intake pipe 21, a three-way catalytic component 22 and an exhaust pipe 23 which are connected in sequence.

[0043] A rotatable baffle is provided inside the three-way catalytic component 22. The baffle is driven by a stepper motor to adjust the opening of the baffle. The stepper motor is connected to the electronic control unit 33 by signal, and the baffle opening is associated with the intake air volume signal received by the electronic control unit 33. From the perspective of chemical kinetics and thermal analysis, the three-way catalytic reaction has strict temperature requirements and can only be carried out efficiently within a specific temperature range. When the engine operating conditions change and the intake air volume changes, the exhaust volume and exhaust temperature will also change accordingly. The traditional three-way catalytic converter with a fixed baffle cannot adapt to this change, resulting in low catalytic efficiency and excessive emissions.

[0044] In the present invention, the electronic control unit 33 accurately controls the stepper motor to adjust the baffle opening according to the real-time intake signal. When the intake increases, the exhaust volume increases accordingly, and the electronic control unit 33 controls the baffle opening to increase, so that the exhaust is smoother and the exhaust back pressure is reduced. At the same time, it is ensured that there is enough gas flow in the catalyst to maintain a suitable temperature and optimize the catalytic reaction conditions. From the principle of catalytic reaction kinetics, it can be seen that the appropriate exhaust back pressure and gas flow can promote the more complete conversion of harmful gases into harmless substances in the three-way catalytic component 22.

[0045] The electronic control unit 33 not only adjusts the opening of the reed valve 32 to control the intake volume, but also synchronously controls the opening of the baffle of the three-way catalytic component 22 according to the engine speed pulse signal and the throttle opening analog value. This feedforward-feedback linkage mechanism enables the intake volume, exhaust back pressure and catalytic efficiency to form a coordinated control loop. The feedforward control adjusts the baffle opening in advance according to the change in the intake volume, and the feedback control further optimizes the baffle opening according to the actual working conditions of the catalyst. Through this coordinated optimization, it is ensured that the catalyst can quickly stabilize to the efficient working temperature range under transient conditions, significantly reduce the emission of incompletely burned substances, and achieve coordinated optimization of emission control and intake volume. While increasing the engine power output, it also improves environmental protection performance to meet increasingly stringent emission regulations.

[0046] Example 3: Optimization of fuel and lubricant supply components This embodiment introduces the refined design of the fuel and lubricating oil supply assembly 4 in detail. Figure 6 .

[0047] The fuel and lubricating oil supply assembly 4 is composed of a fuel and lubricating oil integrated tank 41 , a fuel pump 42 and a lubricating oil pump 43 .

[0048] An independent fuel outlet 411 and a fuel inlet 412 are provided on the upper side wall of the integrated fuel and lubricant tank 41, and a lubricant inlet 413 and a lubricant outlet 414 are provided on the bottom of the side wall. This independent oil port partition design effectively avoids the mixing and contamination of fuel and lubricant based on the principles of material isolation and fluid management. The position layout of different oil ports is based on the difference in fluid density and the principle of gravity, so that the fuel and lubricant can be naturally stratified inside the tank, which is convenient for independent transportation and management.

[0049] The fuel pump 42 includes a main pump body and an auxiliary pump body arranged in parallel. The main pump body supplies fuel to the fuel supply port 141 on the top cover body 14 of the piston cylinder body 13 through the first fuel discharge pipe 421 to meet the high-pressure fuel required for engine combustion. The auxiliary pump body draws fuel from the fuel and lubricating oil integrated box 41 through the second fuel discharge pipe 422 to realize the fuel circulation in the tank. From the perspective of fluid mechanics and the law of conservation of energy, during the fuel transportation process, the pipeline resistance and the compressibility of the fuel are prone to cause air blockage, affecting the continuity of the fuel supply. The circulation function of the auxiliary pump body can replenish the fuel in the pipeline in time, maintain the stability of the fuel pressure in the pipeline, avoid the generation of air blockage, ensure that the engine can obtain a stable and sufficient fuel supply under different working conditions, and ensure the normal operation of the engine.

[0050] The lubricating oil pump 43 extracts the lubricating oil from the fuel and lubricating oil integrated box 41 through the lubricating oil discharge pipe 431 and delivers it to the crankcase 11. The lubricating oil plays a key role in lubrication, cooling and sealing in the crankcase 11. From the analysis of tribology and mechanical lubrication theory, the lubricating oil forms an oil film on the surface of the parts during the operation of the engine, reducing the direct contact and friction wear between the parts, reducing mechanical losses, and extending the service life of the engine parts. At the same time, the lubricating oil can also take away the heat generated by the friction of the parts, play a cooling role, ensure that the engine runs within a suitable temperature range, and maintain the stable performance of the engine.

[0051] Example 4: Overall operation and maintenance of the engine This embodiment comprehensively introduces the specific strategies for overall engine operation and maintenance. Figures 1 to 8 .

[0052] Before starting the engine, check the oil level of the integrated fuel and lubricating oil box 41 to ensure that the fuel outlet 411 and the lubricating oil outlet 414 are not blocked. The lubricating oil is delivered to the crankcase 11 through the lubricating oil pump 43 to form a pre-lubricated state. This operation is based on the principle of tribology. At the moment of engine start-up, pre-lubrication can reduce dry friction between parts, reduce wear, protect engine parts, and extend the overall service life of the engine. At the same time, start the main pump body and auxiliary pump body of the fuel pump 42, establish a fuel circulation through the first fuel drain pipe 421 and the second fuel drain pipe 422, avoid oil circuit air blockage, ensure stable fuel supply, and provide sufficient fuel for engine start-up.

[0053] When the engine is started, the spark plug 142 ignites to start the combustion cycle. The electronic control unit 33 receives the initial pulse signal from the Hall speed sensor and determines the crankshaft position. Under the electromagnetic actuation of the reed switch 34, the reed valve 32 adjusts the free end opening according to the initial speed signal to form a wedge-shaped airflow channel and optimize the mixture intake efficiency in the crankcase 11. Under low-speed conditions, the reed made of elastic titanium alloy reduces turbulence by chamfering the edges, improves scavenging stability, ensures that the engine can work normally during the startup and low-speed operation stages, and outputs stable power. The rotatable baffle in the three-way catalytic assembly 22 is driven by a stepper motor to a preset opening, so that the exhaust back pressure matches the intake volume of the idle condition, avoids the escape of unburned mixture, and reduces emission pollution at idle.

[0054] During the operation of the engine, the electronic control unit 33 generates a duty cycle adjustable driving signal through a fuzzy algorithm based on the real-time speed pulse signal and the throttle opening analog quantity, dynamically adjusts the opening and closing frequency and angle of the reed valve 32, and matches the scavenging efficiency under different power requirements. At the same time, the rotatable baffle opening of the three-way catalytic component 22 is synchronously controlled, and the catalyst temperature and exhaust resistance are optimized by the feedforward-feedback mechanism to reduce emission fluctuations under transient conditions. The labyrinth oil-gas separator in the crankcase 11 separates lubricating oil and exhaust gas through multi-stage staggered guide plates and centrifugal impellers. The separated lubricating oil flows back to the fuel and lubricating oil integrated box 41 through the lubricating oil drain pipe 431, reducing the oil combustion loss, improving the utilization rate of lubricating oil, and reducing emission pollution.

[0055] When the engine needs to be shut down, the electronic control unit 33 gradually closes the reed valve 32 according to the speed reduction signal, reduces the intake volume, avoids the residual mixture from deflagration in the cylinder, and protects the engine parts. At the same time, the damper opening of the three-way catalytic component 22 is synchronously reduced to maintain the exhaust back pressure to the shutdown state, prevents the catalyst from being damaged due to a sudden drop in temperature, and prolongs the service life of the catalyst.

[0056] In terms of daily maintenance, regularly check the wear of the nano coating of the reed valve 32, clean the multi-layer pleated filter of the air filter 31, and ensure that the intake passage is unobstructed. The wear of the nano coating will affect the performance of the reed valve 32, resulting in a decrease in the accuracy of the intake control; the blockage of the air filter 31 will increase the intake resistance, reduce the engine intake volume, and thus affect the combustion efficiency and performance of the engine. Connect the external diagnostic terminal through the CAN bus protocol, retrieve the abnormal parameter records such as the intake flow, exhaust temperature and lubricating oil pressure stored in the electronic control unit 33, and based on the principle of fault diagnosis, targeted maintenance of components such as the fuel pump 42 or the lubricating oil pump 43, timely discover and solve potential problems, ensure the stable operation of the engine, reduce maintenance costs, and improve the reliability and service life of the engine.

[0057] When the present invention is used, the oil level of the integrated fuel and lubricating oil tank 41 is checked to ensure that the fuel outlet 411 and the lubricating oil outlet 414 are not blocked, and the lubricating oil is delivered to the crankcase 11 through the lubricating oil pump 43 to form a pre-lubricating state. The main pump body and the auxiliary pump body of the fuel pump 42 are started, and the fuel circulation is established through the first fuel discharge pipe 421 and the second fuel discharge pipe 422 to avoid oil circuit air blockage.

[0058] The electronic control unit 33 detects the intake air flow, exhaust temperature and lubricating oil pressure parameters through a multi-channel data acquisition module, and compares them with preset thresholds. After confirming that there is no abnormal alarm signal, it enters the standby mode.

[0059] The combustion cycle is started by ignition of the spark plug 142, and the electronic control unit 33 receives the initial pulse signal of the Hall speed sensor to determine the crankshaft position; the reed valve 32 is electromagnetically actuated by the reed switch 34, and adjusts the free end opening according to the initial speed signal to form a wedge-shaped airflow channel, thereby optimizing the mixture intake efficiency in the crankcase 11; the reed made of elastic titanium alloy reduces turbulence by chamfering the edges, thereby improving the scavenging stability under low-speed conditions; the rotatable baffle in the three-way catalytic assembly 22 is driven by a stepper motor to a preset opening, so that the exhaust back pressure matches the intake volume under idle conditions to prevent the escape of unburned mixture.

[0060] The electronic control unit 33 generates a duty cycle adjustable driving signal through a fuzzy algorithm based on the real-time speed pulse signal and the throttle opening analog value, dynamically adjusts the opening and closing frequency and angle of the reed valve 32, and matches the scavenging efficiency under different power requirements; synchronously controls the opening of the rotatable baffle of the three-way catalytic component 22, and optimizes the catalyst temperature and exhaust resistance by using the feedforward-feedback mechanism, thereby reducing emission fluctuations under transient conditions; by adjusting the opening of the back pressure valve of the exhaust component 2, combined with the back-filling effect of the beam wave exhaust pipe in the related technology that is not explicitly mentioned in the patent, the exhaust pressure wave is used to push the escaping mixture back into the cylinder to improve the combustion efficiency; the labyrinth oil-gas separator in the crankcase 11 separates the lubricating oil and exhaust gas through a multi-stage guide plate and a centrifugal impeller, and the separated lubricating oil flows back to the fuel and lubricating oil integrated box 41 through the lubricating oil drain pipe 431, thereby reducing the oil combustion loss.

[0061] The electronic control unit 33 gradually closes the reed valve 32 according to the speed reduction signal, reducing the intake volume to avoid the explosion of the residual mixture in the cylinder; the baffle opening of the three-way catalytic component 22 is simultaneously reduced to maintain the exhaust back pressure to the shutdown state to prevent the catalyst from being damaged due to a sudden drop in temperature; the nano-coating wear of the reed valve 32 is regularly checked, and the multi-layer pleated filter of the air filter 31 is cleaned to ensure that the intake passage is unobstructed; the external diagnostic terminal is connected through the CAN bus protocol, and the abnormal parameter records stored in the electronic control unit 33 are retrieved to perform targeted maintenance on the fuel pump 42 or the lubricating oil pump 43.

Claims

1. A high-power two-stroke industrial engine with variable exhaust, comprising: The engine body (1) is composed of a crankcase (11) and a piston cylinder (13) drivingly connected to the crankshaft; An exhaust assembly (2) is composed of an intake pipe (21), a three-way catalytic assembly (22) and an exhaust pipe (23) which are connected in sequence; Features: A first support frame (111) and a second support frame (112) are respectively arranged on both sides of the bottom of the crankcase (11), and an air intake groove (113) connected to an external air source is opened on the front side of the crankcase (11); The piston cylinder (13) and the crankshaft in the crankcase (11) form a linkage mechanism; The crankcase (11) is provided with an air intake control unit (3) at the air intake groove (113); The air intake control unit (3) comprises: The reed valve (32) is composed of a valve seat and at least two elastic metal reeds arranged in a stacked manner, wherein the reed is hinged to the top of the valve seat via an adjustable pin, and the arc-shaped free end of the reed forms a dynamically opened and closed wedge-shaped air flow channel with the bottom of the valve seat; An air filter (31) having a multi-layer pleated filter structure is vertically arranged at the air inlet end of the reed valve (32); An electronic control unit (33) has a microprocessor and a drive circuit linked to the engine, and is connected to a Hall speed sensor arranged at the crankshaft end via a bus; A reed switch (34) is embedded in the outer periphery of the valve body of the reed valve (32) in a magnetic shielding packaging structure, and a contact switch of the reed switch (34) and an electronic control unit (33) form a closed-loop feedback control circuit for adjusting the opening angle of the reed valve (32) in real time; The electronic control unit (33) generates a duty cycle adjustable driving signal through a fuzzy algorithm based on the real-time collected speed pulse signal and throttle opening analog quantity, and accurately adjusts the opening angle and frequency of the reed valve (32) through the electromagnetic actuation of the reed switch (34), thereby achieving dynamic optimization of the scavenging efficiency of the piston cylinder (13), and synchronously controls the back pressure valve opening of the exhaust component (2) through an air pressure feedback mechanism.

2. A high-power two-stroke industrial engine with variable exhaust according to claim 1, characterized in that: The engine body (1) further comprises a transmission assembly (12) mounted on one side of the crankcase (11); the transmission assembly (12) forms a power transmission connection with the crankshaft in the crankcase (11) via a spline coupling.

3. A high-power two-stroke industrial engine with variable exhaust according to claim 1, characterized in that: The reed of the reed valve (32) is made of a high-elasticity titanium alloy, a titanium nitride coating is provided on the surface of the reed, and the free end of the reed is chamfered to form a smooth transition edge.

4. A high-power two-stroke industrial engine with variable exhaust according to claim 1, characterized in that: The magnetic sensing element inside the reed switch (34) detects the rotation angle change of the pin shaft in a non-contact manner, generates a reed opening feedback signal in real time, and transmits it to the electronic control unit (33).

5. A high-power two-stroke industrial engine with variable exhaust according to claim 1, characterized in that: A rotatable baffle is provided inside the three-way catalytic component (22), and the baffle is opened by a stepper motor driving a rotating shaft. The stepper motor is connected to an electronic control unit (33) by signal, and the baffle opening is associated with an intake air volume signal received by the electronic control unit (33).

6. A high-power two-stroke industrial engine with variable exhaust according to claim 1, characterized in that: The invention also comprises a fuel and lubricating oil supply assembly (4), the fuel and lubricating oil supply assembly (4) comprising a fuel and lubricating oil integrated box (41), a fuel pump (42) and a lubricating oil pump (43), a cover body (14) being provided on the top of the piston cylinder body (13), the cover body (14) being an integrated casting structure, and a fuel supply port (141) communicating with the fuel pump (42) and a spark plug (142) connected with the ignition system being provided on the top of the cover body (14).

7. A high-power two-stroke industrial engine with variable exhaust according to claim 6, characterized in that: The fuel pump (42) comprises a main pump body and an auxiliary pump body arranged in parallel, the main pump body supplies fuel to the fuel supply port (141) through a first fuel discharge pipe (421), and the auxiliary pump body draws fuel from a fuel and lubricating oil integrated tank (41) through a second fuel discharge pipe (422).

8. A high-power two-stroke industrial engine with variable exhaust according to claim 6, characterized in that: An independent fuel outlet (411) and a fuel inlet (412) are provided above the side wall of the integrated fuel and lubricating oil box (41); a lubricating oil inlet (413) and a lubricating oil outlet (414) are provided at the bottom of the side wall of the integrated fuel and lubricating oil box (41); and a lubricating oil pump (43) extracts lubricating oil from the integrated fuel and lubricating oil box (41) through a lubricating oil discharge pipe (431) and delivers the lubricating oil to the crankcase (11).

9. A high-power two-stroke industrial engine with variable exhaust according to claim 1, characterized in that: The crankcase (11) is provided with a labyrinth oil-gas separator, and the oil-gas separator is provided with multi-stage staggered guide plates and centrifugal impellers. The separated lubricating oil flows back to the fuel and lubricating oil integrated box (41) through the lubricating oil discharge pipe (431).

10. A high-power two-stroke industrial engine with variable exhaust according to claim 1, characterized in that: The electronic control unit (33) has a built-in multi-channel data acquisition module, which transmits intake air flow, exhaust temperature and lubricating oil pressure data to an external diagnostic terminal via a CAN bus protocol, and triggers an alarm signal when the parameters are abnormal.

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