Low-fuel evaporation system of general engine and working machine
By using a low-fuel evaporation system with carbon canister and normally closed solenoid valve in general engines, the evaporation emissions of the carburetor are solved, and efficient emissions are achieved Reduce and environmental protection goals, reducing system costs.
Patent Information
- Application Number
- CN202421060808.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-05-16
- Publication Date
- 2024-12-20
- Estimated Expiration
- 2034-05-16
AI Technical Summary
During the shutdown state, the existing carburetors cause the evaporated fuel emissions to be directly discharged into the atmosphere, causing air pollution. The electronic injection system is costly and complex in control, making it difficult to meet strict emission standards.
A low fuel evaporation system was designed to absorb the evaporated emissions of the carburetor using carbon canisters and normally closed solenoid valves and burn them when the engine is running, achieving closed-loop operation, reducing evaporation emissions, and through a simple structural layout and low Cost materials reduce emissions.
It effectively reduces the emission of evaporated emissions of carburetors, meets green and environmental protection requirements, reduces pollution to the atmospheric environment, improves fuel utilization, and simplifies the system structure and reduces costs.
Smart Images
Figure CN222208109U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of a low fuel evaporation system for a general engine, in particular to a low fuel evaporation system for a general engine. Background Art
[0002] At present, carburetors are widely used in the fuel supply system of fuel engines. Carburetors have the advantages of simple structure, low cost, stable performance, etc. However, due to the limitation of the structure of the carburetors themselves, when the fuel engine is in a shutdown state, the evaporative emissions generated in the carburetors will be directly discharged into the atmosphere through the nozzle, balance port and other channels, causing air pollution. The new US regulations CARB2024 require that fuel engines with a displacement of less than 225cc must meet the requirements of tilting 90° on each of the other three directions except the engine air intake direction, and last for 5 minutes without fuel leakage; and the overall evaporation of the fuel engine must not exceed 0.6g. Therefore, it is necessary to solve the problem of air pollution caused by carburetors' evaporative emissions. The existing technology generally adopts the electronic fuel injection system solution, which can meet the requirements of dumping and evaporative emissions, but the electronic fuel injection system has a long matching time, a complex control program, and high cost. Therefore, it is necessary to further research and develop new technologies to reduce the emission of carburetor evaporative emissions, thereby reducing the degree of pollution to the atmospheric environment. Optimizing and adjusting the existing carburetors to meet the evaporative emission requirements can greatly reduce costs compared to the electronic fuel injection system and enhance the market competitiveness of the product. Summary of the invention
[0003] The purpose of this application is to provide a low fuel evaporation system for a general engine, which can effectively reduce the fuel evaporation loss of the engine, improve fuel utilization, reduce environmental pollution, and improve engine performance.
[0004] To achieve the above-mentioned objectives, the present application proposes the following technical solutions: A low-fuel evaporation system for a general engine, comprising a fuel tank, a carbon canister, a carburetor and an air filter, the carbon canister being provided with a first adsorption port, a second adsorption port and a desorption port, the diaphragm switch of the carburetor being connected to the fuel tank through an oil pipe, the vent valve of the fuel tank being connected to the first adsorption port of the carbon canister through a first vent pipe, the balance port of the carburetor being connected to the second adsorption port of the carbon canister through a second vent pipe, and the air filter being connected to the desorption port of the carbon canister through a third vent pipe.
[0005] Furthermore, the first adsorption port, the second adsorption port, and the desorption port are located at the same end of the carbon canister.
[0006] Furthermore, the oil tank also includes a ventilation valve, and the first ventilation pipe is connected to the oil tank through the ventilation valve.
[0007] Furthermore, the fuel tank also includes a fuel tank cover, on which a sealing gasket is arranged, and the sealing gasket is made of fluororubber.
[0008] Furthermore, the membrane switch is provided with an oil receiving port, and the oil receiving port is connected to one end of the oil pipe.
[0009] Furthermore, the inner layer of the oil pipe is made of fluororubber, and the outer layer is made of nitrile rubber.
[0010] Furthermore, the first ventilation pipe, the second ventilation pipe and the third ventilation pipe are made of fluororubber material.
[0011] Furthermore, it also includes a solenoid valve, which is a normally closed solenoid valve.
[0012] Furthermore, the top end of the needle valve of the solenoid valve is made of fluororubber material.
[0013] In order to better achieve the above-mentioned purpose, the present application also discloses a working machine, which includes the low fuel evaporation system of the above-mentioned general engine.
[0014] In summary, the present application includes at least one of the following beneficial effects: when the general engine is in a shutdown state, the evaporative emissions at the carburetor balance port and inside the fuel tank enter the carbon canister through the vent pipe, and at this time, the normally closed solenoid valve greatly reduces the amount of evaporative emissions inside the carburetor discharged into the atmosphere through the nozzle; when the general engine is in a running state, the air filter draws the evaporative emissions adsorbed inside the carbon canister into the combustion chamber of the engine for combustion. The entire low-fuel evaporation system, on the one hand, can achieve closed-loop operation to reduce evaporative emissions, meet the corresponding emission standards, and meet the requirements of green environmental protection; on the other hand, the entire system does not use structures such as one-way valves to limit the flow direction of evaporative emissions, and the entire system structure layout is simple and low cost. BRIEF DESCRIPTION OF THE DRAWINGS
[0015] Figure 1 This is a schematic diagram of the structure of this application.
[0016] Figure 2 This is a schematic diagram of the membrane switch structure in this application.
[0017] Figure 3 This is a schematic diagram of the carbon canister structure in this application.
[0018] Figure 4 This is a schematic diagram of the fuel tank structure in this application.
[0019] Description of reference numerals:
[0020] Fuel tank 1 fuel pipe 11 ventilation valve 12 fuel outlet nozzle 13 fuel tank cap 14 carbon canister 2 first adsorption port 21 second adsorption port 22 desorption port 23 atmospheric air outlet 24 carburetor 3 diaphragm switch body 31 diaphragm 311 oil receiving port 3111 diaphragm support plate 312 spring 313 diaphragm switch cover 314 connecting pipe 315 fastening bolt 316 sealing ring 317 normally closed solenoid valve 32 air filter 4 first ventilation pipe 51 second ventilation pipe 52 third ventilation pipe 53. DETAILED DESCRIPTION
[0021] The following is an explanation of the implementation of the present invention through specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific implementations, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention.
[0022] The following is combined with Figure 1-4 The utility model is described in further detail.
[0023] like Figure 1-4As shown, the present application is a low fuel evaporation system for a general engine, comprising a fuel tank 1, a carbon canister 2, a carburetor 3 and an air filter 4, the carbon canister 2 is provided with a first adsorption port 21, a second adsorption port 22, and a desorption port 23, the diaphragm switch 31 of the carburetor 3 is connected to the fuel tank 1 through the fuel pipe 11, the fuel tank 1 is connected to the first adsorption port 21 of the carbon canister 2 through the first ventilation pipe 51, the balance port of the carburetor 3 is connected to the second adsorption port 22 of the carbon canister 2 through the second ventilation pipe 52, and the air filter 4 is connected to the desorption port 23 of the carbon canister 2 through the third ventilation pipe 53. When the universal engine is in a shutdown state, the diaphragm switch 31 is always kept closed to prevent the fuel in the fuel tank 1 from entering the carburetor 3, and the solenoid valve is always kept closed to prevent the fuel inside the carburetor 3 from evolving into the nozzle in the carburetor 3. At this time, the evaporative emissions in the fuel tank 1 enter the carbon canister 2 through the vent valve and the first vent pipe 51 and are adsorbed by the carbon powder inside the carbon canister 2. At the same time, the evaporative emissions in the carburetor 3 enter the carbon canister 2 through the balance port and the second vent pipe 52 and are adsorbed by the carbon canister 2. When the universal engine is in a running state: the diaphragm switch 31 and the solenoid valve are always kept open, the evaporative emissions in the fuel tank 1 enter the carbon canister 2 through the vent valve and the first vent pipe 51 and are adsorbed by the carbon canister 2. The evaporative emissions in the carburetor 3 enter the carbon canister 2 through the balance port and the second vent pipe 52 and are adsorbed by the carbon canister 2. At this time, the desorption port 23 of the carbon canister 2 generates a negative pressure. Under the action of the negative pressure, the air filter 4 sucks the evaporative emissions adsorbed inside the carbon canister 2 into the combustion chamber of the engine through the third vent pipe 53 for combustion. On the one hand, the entire low-fuel evaporation system realizes closed-loop operation, thereby reducing evaporative emissions, reaching corresponding emission standards, and meeting green environmental protection requirements; on the other hand, the entire low-fuel evaporation system does not use structures such as one-way valves for controlling the flow direction of evaporative emissions in the prior art, and the entire structural layout is simple and the cost is low.
[0024] In this embodiment, Figure 3 As shown, an interface for connecting the balance port of the carburetor 3 is added to the carbon canister 2, and the carbon canister 2 is connected to the carburetor 3 through the balance port of the carburetor 3. The evaporative emissions inside the carburetor 3 enter the carbon canister 2 through the balance port and the second vent pipe 52. The carbon canister 2 adsorbs most of the evaporative emissions onto the carbon powder inside the carbon canister 2, which can greatly reduce the overall evaporative emissions of the fuel engine and improve fuel utilization; at the same time, the evaporative emissions in the fuel tank 1 enter the carbon canister 2 through the vent valve and the first vent pipe 51. The carbon canister 2 adsorbs most of the evaporative emissions onto the carbon powder, and the remaining gas flows into the atmosphere. At the same time, the present application has a simple structure and is easy to achieve the emission matching requirements of general engines; the carbon canister, fuel tank, carburetor, air filter and their pipelines simplify the pipeline wiring and reduce the cost of the fuel evaporation device of the original general engine.
[0025] In this embodiment, the fuel tank 1 further includes a vent valve 12, a fuel nozzle 13 and a fuel tank cap 14. The first vent pipe 51 is connected to the vent valve 12 to achieve communication between the carbon canister 2 and the fuel tank 1. The fuel pipe 11 is connected to the fuel nozzle 13 to achieve communication between the carburetor 3 and the fuel tank 1. At the same time, a sealing gasket is provided on the fuel tank cap 14. The sealing gasket is made of fluororubber to enhance the sealing performance of the fuel tank cap 14.
[0026] In this embodiment, Figure 2 As shown, the membrane switch 31 is composed of a membrane switch body 311, a membrane 312, a membrane support plate 313, and a membrane switch cover 315. The diaphragm 312, the diaphragm support plate 313, and the membrane switch cover 315 are sequentially installed in the membrane switch body 311, a spring 314 is provided between the diaphragm support plate 313 and the membrane switch cover 315, the diaphragm switch cover 31 is fixed to the diaphragm switch body 311 by fastening bolts 316, the diaphragm switch body 311 is fixed to the carburetor by fastening bolts 316, and a sealing ring 317 is also provided at the fixed connection between the diaphragm switch 31 and the carburetor 3. The diaphragm switch 3 is also provided with an oil receiving port 3111, which is connected to the oil tank 1 through the oil pipe 11. By arranging the diaphragm switch 31 structure on the carburetor 3, it is realized that when the general engine is in the shutdown state, the diaphragm switch 31 closes the diaphragm 312 through the internal spring 313 structure to prevent the fuel in the fuel tank 1 from entering the carburetor 3; when the general engine is in the running state, the negative pressure generated by the throttle valve of the carburetor 3 sucks the diaphragm 312 open, so that the carburetor 3 can operate normally.
[0027] In this embodiment, one end of the first ventilation pipe 51 , the second ventilation pipe 52 and the third ventilation pipe 53 are connected to the same end of the carbon canister 2 .
[0028] In this embodiment, in order to enhance the sealing performance of the entire evaporation system, enhancing the sealing performance of the components themselves can effectively prevent the leakage of evaporative emissions. Therefore, the sealing gaskets and sealing rings 317 involved in the fuel tank 1, carburetor 3, diaphragm switch 31, and solenoid valve 32 are all made of fluororubber material, which plays a key role in enhancing the sealing performance of the entire evaporation system.
[0029] In this embodiment, in order to enhance the sealing performance of the entire evaporation system, the sealing performance of the connection position is also enhanced to effectively prevent the leakage of evaporative emissions. For example, the oil pipe 11 is made of a double-layer material, wherein the inner layer is made of fluororubber and the outer layer is made of nitrile rubber. The fluororubber material of the inner layer can directly contact the fuel. Further optimization is performed, the first ventilation pipe 51, the second ventilation pipe 52, and the third ventilation pipe 53 are all made of fluororubber as the inner layer and epichlorohydrin rubber as the outer layer. At the same time, the connections between the first ventilation pipe 51, the second ventilation pipe 52, the third ventilation pipe 53 and the oil pipe 11 are all fixed by clamping.
[0030] In this embodiment, the solenoid valve 32 is a normally closed solenoid valve and is located at the bottom of the carburetor 3. Normally, when the general engine is in a shutdown state, the needle valve of the normally closed solenoid valve 32 is in a normally closed position, blocking the oil inlet on the oil cup of the carburetor that enters the nozzle, which can not only prevent the fuel inside the carburetor 3 from entering the nozzle, but also prevent the fuel from being retained and evaporated in the oil circuit behind the oil inlet hole of the carburetor 3, reducing the loss of fuel, and in addition, it can also block the oil circuit of the main nozzle at the same time to avoid fuel leakage and safety hazards; when the general engine is in a working state, the needle valve of the normally closed solenoid valve 32 is in a normally open position, at this time the oil inlet between the oil cup and the nozzle is unobstructed, so that the carburetor 3 can operate normally, thereby realizing accurate control of the fuel supply, which helps to improve the utilization efficiency of fuel and reduce fuel waste. Evaporative emissions from the carburetor balance port and inside the fuel tank enter the universal engine carbon canister 2 through the vent pipe. At this time, the normally closed solenoid valve 32 greatly reduces the amount of evaporative emissions from inside the carburetor 3 discharged into the atmosphere through the nozzle; at the same time, the top of the needle valve of the normally closed solenoid valve 32 is made of fluororubber material, which can better seal the oil inlet on the oil cup entering the nozzle after power is off, preventing the evaporative emissions from inside the carburetor 3 from being directly discharged into the atmosphere through the nozzle.
[0031] In this embodiment, a port connected to the balancing port of the carburetor 3, namely the second adsorption port 22, is added to the carbon canister 2. When the fuel engine is in a shutdown state, the evaporative emissions inside the carburetor 3 enter the carbon canister 2 through the balancing port and the vent pipe. The carbon canister 2 adsorbs most of the evaporative emissions onto the carbon powder, which can greatly reduce the overall evaporative emissions of the fuel engine. Specifically, the carbon canister 2 is provided with a first adsorption port 21 connected to the first ventilation pipe 51, a second adsorption port 22 connected to the second ventilation pipe 52, a desorption port 23 connected to the third ventilation pipe 53, and an atmosphere port connected to the atmosphere. When the general engine is in a shutdown state, the evaporative emissions in the fuel tank 1 enter the carbon canister 2 through the ventilation valve and the first ventilation pipe 51, and the carbon canister 2 adsorbs most of the evaporative emissions onto the carbon powder, and the remaining gas flows to the atmosphere through the outlet 24; when the general engine is in a running state, the air filter 4 generates negative pressure, and the evaporative emissions adsorbed in the carbon canister 2 are sucked out through the third ventilation pipe 53 and transported to the combustion chamber of the general engine for combustion, which can greatly reduce the overall evaporative emissions of the fuel engine.
[0032] The present application also discloses a working machine, comprising the low fuel evaporation system of any general engine described above, and the working machine may be a generator set.
[0033] The present application also discloses a flameout control method for a general engine, comprising a flameout switch connected to the general engine, a carburetor 3, and a fuel tank 1, wherein the carburetor 3 is provided with a diaphragm switch and a normally closed battery valve 32; the method comprises: step 1: when the general engine is operating normally, the flameout switch state is changed; step 2: the normally closed solenoid valve 32 is immediately powered off and in a normally closed state, and the igniter stops igniting after a preset time. When the flameout switch state in the above step 1 changes to the flameout state, the igniter continues to ignite, and the normally closed solenoid valve 32 is immediately powered off and in a normally closed state, preventing the fuel inside the carburetor 3 from entering the main nozzle of the carburetor 3. At this time, the residual fuel inside the nozzle can still make the general engine operate normally, and the diaphragm switch remains open; until the residual fuel in the main nozzle of the carburetor 3 is burned out, the general engine automatically turns off within the preset time when the igniter stops igniting, and the diaphragm switch is in a closed state to prevent the fuel in the fuel tank from entering the carburetor 3. Specifically, when the flameout switch changes the flameout switch state, that is, the flameout switch disconnects the power supply of the normally closed battery valve 32, and transmits the flameout signal to the igniter, after the igniter receives the flameout signal, the preset ignition stop program runs, and the normally closed solenoid valve is immediately powered off and is in a closed state to prevent the fuel inside the carburetor 3 from entering the main nozzle of the carburetor 3, but the diaphragm switch 31 of the carburetor 3 continues to remain open, and the fuel in the fuel tank enters the carburetor 3 through the diaphragm switch 31. After a certain period of time, the float chamber needle valve of the carburetor 3 blocks the oil inlet of the carburetor 3 and prevents the fuel from entering the carburetor 3; within the preset ignition stop time of the igniter, the residual fuel in the nozzle of the carburetor 3 will be sucked into the combustion chamber and continue to burn until the residual fuel in the nozzle is exhausted. The automatic flameout time of the general engine is shorter than the preset ignition stop time of the igniter, that is, the general engine automatically shuts down within the preset ignition stop time of the igniter. The fuel remaining in the nozzle of the carburetor 3 is completely burned, which solves the problem of direct discharge of part of the fuel remaining in the nozzle into the atmosphere through the nozzle, causing environmental pollution, and can reduce the evaporative emissions of general engines.
[0034] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the utility model rather than to limit it. Although the utility model has been described in detail with reference to the preferred embodiments, ordinary technicians in the field should understand that the technical solution of the utility model can be modified or replaced by equivalents without departing from the purpose and scope of the technical solution of the utility model, which should be included in the scope of the claims of the utility model.
Claims
1. A low fuel evaporation system for a general engine, comprising a fuel tank, a carbon canister, a carburetor and an air filter, characterized in that: The carbon canister is provided with a first adsorption port, a second adsorption port, and a desorption port. The diaphragm switch of the carburetor is connected to the fuel tank through an oil pipe. The fuel tank is connected to the first adsorption port of the carbon canister through a first ventilation pipe. The balance port of the carburetor is connected to the second adsorption port of the carbon canister through a second ventilation pipe. The air filter is connected to the desorption port of the carbon canister through a third ventilation pipe.
2. The low fuel evaporation system for a general engine as claimed in claim 1, characterized in that: The first adsorption port, the second adsorption port and the desorption port are located at the same end of the carbon canister.
3. The low fuel evaporation system for a general engine as claimed in claim 1, characterized in that: The oil tank further includes a vent valve, and the first vent pipe is connected to the oil tank through the vent valve.
4. The low fuel evaporation system for a general engine as claimed in claim 1, characterized in that: The oil tank further comprises an oil tank cover, on which a sealing gasket is arranged, and the sealing gasket is made of fluororubber.
5. The low fuel evaporation system for a general engine as claimed in claim 1, characterized in that: The membrane switch is provided with an oil receiving port, and the oil receiving port is connected to one end of the oil pipe.
6. The low fuel evaporation system for a general engine as claimed in claim 1, characterized in that: The inner layer of the oil pipe is made of fluororubber, and the outer layer is made of epichlorohydrin rubber.
7. The low fuel evaporation system for a general engine as claimed in claim 1, characterized in that: The inner layers of the first ventilation pipe, the second ventilation pipe and the third ventilation pipe are made of fluororubber, and the outer layers are made of epichlorohydrin rubber.
8. The low fuel evaporation system for a general engine as claimed in claim 1, characterized in that: It also includes a solenoid valve, which is a normally closed solenoid valve.
9. The low fuel evaporation system for a general engine as claimed in claim 8, characterized in that: The needle valve top of the solenoid valve is made of fluororubber material.
10. A working machine, characterized in that: A low fuel evaporation system for a general engine comprising the method according to any one of claims 1 to 7.