Carburetor motorcycle fuel evaporation system

Abstract

The present application relates to a kind of carburetor motorcycle fuel evaporation systems, including fuel tank, air filter, ignition controller and carbon tank, the air filter is connected carburetor, the carburetor is connected engine by intake pipe;The oil outlet of the fuel tank is connected by oil pipe with the oil inlet of carburetor, the fuel tank is connected the carbon tank by oil gas pipe, the carbon tank is connected to the intake pipe by desorption pipe, electromagnetic valve is equipped on the desorption pipe, the ignition controller controls connection electromagnetic valve.The carburetor motorcycle fuel evaporation system of the present application still uses electromagnetic valve control scheme, maintains the controllability of carbon tank desorption time and quantity, and is connected by ignition controller of carburetor motorcycle to control electromagnetic valve, in combination with the difference of speed, the duty cycle of electromagnetic valve is controlled and adjusted in real time, thereby avoid the problem of the controllability of carbon tank desorption time and quantity on carburetor motorcycle, obtain the effect of easy control, adjustment.

Description

Technical Field

[0001] This invention belongs to the field of engine technology of hot gas or combustion products, and specifically relates to a fuel evaporation system for a carburetor motorcycle. Background Technology

[0002] In internal combustion engine vehicles, the carbon canister adsorbs fuel vapors from the fuel tank. During engine operation, negative pressure causes the adsorbed fuel vapor molecules to desorb and enter the engine for combustion, thus reducing the amount of fuel vapor molecules released into the atmosphere and controlling emissions. In hybrid vehicles or electronically fuel-injected motorcycles, various sensors and highly integrated ECUs are used. The ECU combines data from these sensors to make comprehensive judgments and control the timing and duration of carbon canister desorption, the opening degree and duration of the carbon canister solenoid valve, and adjust the duty cycle to control the timing and amount of carbon canister desorption. For details, please refer to existing technologies such as CN117145661A and CN115163350A.

[0003] In traditional carburetor motorcycles, due to the relatively simple electronic control system, carbon canister desorption is controlled by a one-way valve on the connecting pipe between the carbon canister and the carburetor. When the engine starts, negative pressure draws fuel molecules from the carbon canister through the one-way valve and carburetor into the engine; see existing technologies such as CN201865795U and CN201358852Y. At idle or low speeds, the low negative pressure closes the one-way valve, preventing carbon canister desorption. At medium and high speeds, the increased negative pressure at the carburetor's desorption port opens the one-way valve on the connecting pipe, allowing carbon canister desorption. This controls the timing of carbon canister desorption, reducing its impact on the engine's air-fuel ratio. However, the amount of carbon canister desorption is solely determined by the negative pressure, lacking flexibility and adjustment capabilities. Summary of the Invention

[0004] In view of the above-mentioned shortcomings of the existing technology, the technical problem to be solved by the present invention is to provide a fuel evaporation system for carburetor motorcycles, so as to avoid the problem of insufficient controllability of the timing and amount of carbon canister desorption on carburetor motorcycles, and to achieve the effect of easy control and adjustment.

[0005] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows:

[0006] A carburetor motorcycle fuel evaporation system includes a fuel tank, an air filter, an ignition controller, and a carbon canister. The air filter is connected to the carburetor, which is connected to the engine via an intake manifold. The fuel tank is connected to the carbon canister via a fuel-air pipe. The carbon canister is connected to the intake manifold via a desorption pipe (compared to being connected to the carburetor's intake passage, this provides sufficient negative pressure during engine operation, better ensuring the amount of desorption). A solenoid valve is installed on the desorption pipe, and the ignition controller controls the solenoid valve. The ignition controller, in conjunction with the engine speed, controls the duty cycle ratio of the solenoid valve.

[0007] To further improve the above technical solution, the oil and gas pipe is connected to a one-way valve via a tee to allow one-way ventilation to the atmosphere, thereby balancing the gas pressure inside the fuel tank.

[0008] Furthermore, the engine is connected to a secondary air supply valve via a secondary air supply pipe, the air filter is connected to the inlet end of the secondary air supply valve via a first pipe, and the secondary air supply valve is also connected to the air supply pipe via a second pipe.

[0009] Compared with the prior art, the present invention has the following advantages:

[0010] The fuel evaporation system of the carburetor motorcycle of the present invention still adopts the solenoid valve control scheme to maintain the controllability of the timing and amount of carbon canister desorption. The solenoid valve is connected to the ignition controller of the carburetor motorcycle and is controlled and adjusted in real time according to the different speeds. This avoids the problem of insufficient controllability of the timing and amount of carbon canister desorption on carburetor motorcycles and achieves the effect of easy control and adjustment. Attached Figure Description

[0011] To make the purpose, technical solution, and advantages of the invention clearer, the invention will now be described in further detail with reference to the accompanying drawings:

[0012] Figure 1 A schematic diagram of a carburetor motorcycle fuel evaporation system as an example;

[0013] Figure 2 This is a schematic diagram of the solenoid valve control for the ignition controller.

[0014] Among them, air filter 1, carburetor 2, intake pipe 3, engine 5, fuel tank 6, fuel evaporation vent pipe 61, carbon canister 7, fuel-air pipe 71, tee 72, one-way valve 73, desorption pipe 75, solenoid valve 76, ignition controller 8, secondary air injection valve 9, first pipe 91, second pipe 92, and secondary air injection intake pipe 93. Detailed Implementation

[0015] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings.

[0016] Please see Figure 1 A specific embodiment of a carburetor motorcycle fuel evaporation system includes a fuel tank 6, an air filter 1, an ignition controller 8, and a carbon canister 7. The air filter 1 is connected to a carburetor 2, which is connected to an engine 5 via an intake manifold 3. The fuel outlet of the fuel tank 6 is connected to the fuel inlet of the carburetor 2 via a fuel line (not shown in the figure). The fuel evaporation vent pipe 61 of the fuel tank 6 is connected to a vapor adsorption pipe 71, which is connected to the vapor adsorption port of the carbon canister 7. The vapor desorption port of the carbon canister 7 is connected to the intake manifold 3 via a desorption pipe 75. A solenoid valve 76 is installed on the desorption pipe 75. The ignition controller 8 controls the solenoid valve 76. The ignition controller 8 controls the duty cycle ratio of the solenoid valve 76 based on the engine speed of the engine 5. The engine speed is positively correlated with the negative pressure in the engine intake manifold; the engine speed determines the magnitude of the negative pressure. Using the engine speed as an input parameter allows for more direct feedback control.

[0017] The fuel evaporation system of the carburetor motorcycle in this embodiment, similar to that of hybrid vehicles or electronic fuel injection motorcycles, still employs a solenoid valve control scheme to maintain controllability of the timing and amount of carbon canister desorption. The solenoid valve 76 is controlled by the ignition controller 8 of the carburetor motorcycle, which controls its opening. Carburetor motorcycles do not have an ECU for controlling fuel injection and unified ignition management; the electronic control section is relatively simple. The ignition controller 8 is arguably the most complex electronic device on a carburetor motorcycle. Traditionally, it determines a relatively fixed ignition timing based on the engine speed signal. In this embodiment, the ignition controller 8 controls the solenoid valve 76, thus combining the functions of controlling ignition timing and solenoid valve opening. The principle can be found in [link to relevant documentation]. Figure 2 The engine speed signal of engine 5 is acquired via a trigger. After being amplified by an amplification and buffer circuit, the signal is synchronously transmitted to the two MCUs of the ignition controller 8. One MCU outputs a real-time control signal to the solenoid valve drive circuit based on the engine speed of engine 5, thereby controlling the duty cycle of solenoid valve 76 and controlling the opening and closing of the carbon canister control solenoid valve 76. The other MCU outputs a control logic signal to the ignition circuit, thereby controlling the ignition coil to ignite. The trigger acquisition of engine speed, ignition control, and power supply connections are all existing and will not be described in detail here.

[0018] In terms of specific control parameters, the ignition controller 8 controls the duty cycle of the solenoid valve 76 in real time by detecting different engine speeds of the engine 5. The fuel vapor in the carbon canister 7 will reach the intake manifold 3 through the desorption pipe 75 and enter the combustion chamber of the engine 5 to participate in combustion, thereby enabling the carbon canister 7 to achieve stable desorption capacity and meet the fuel evaporation requirements of carburetor motorcycles. The control parameters are selectable: after the engine 5 starts, the ignition controller 8 collects the real-time speed of the engine 5. When the speed is below 2500 r / min, the solenoid valve 76 is closed, and the carbon canister 7 does not perform desorption to avoid affecting the air-fuel ratio of the engine. When the engine speed is between 2500 r / min and 3000 r / min, the ignition controller 8 outputs a square wave signal with a frequency of 16 Hz and a duty cycle of 30% to control the solenoid valve 76. As the speed continues to increase, the duty cycle increases by 5% for every 500 r / min increase in engine speed, thereby meeting the fuel evaporation requirements while ensuring that the engine will not stall due to excessive intake air volume. The control parameters can be adjusted and preset in the ignition controller. This avoids the problem of insufficient control over the timing and amount of carbon canister desorption on carburetor motorcycles, achieving a more controllable and adjustable effect.

[0019] The oil and gas pipe 71 is connected to a one-way valve 73 via a tee 72, which is used to allow one-way ventilation to the atmosphere in order to balance the air pressure inside the fuel tank 6 and ensure the normal working pressure of the fuel tank 6.

[0020] The engine 5 is connected to the secondary air supply valve 9 via a secondary air supply pipe 93. The air filter 1 is connected to the inlet end of the secondary air supply valve 9 via a first pipe 91. The secondary air supply valve 9 is also connected to the intake pipe 3 via a second pipe 92. In this way, the air supply device further effectively reduces exhaust pollutants from the motorcycle.

[0021] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit the technical solutions. Those skilled in the art should understand that any modifications or equivalent substitutions to the technical solutions of the present invention without departing from the spirit and scope of the present invention should be covered within the scope of the claims of the present invention.

Claims

1. A carburetor motorcycle fuel evaporation system, comprising a fuel tank, an air filter, an ignition controller, and a carbon canister, wherein the air filter is connected to the carburetor, and the carburetor is connected to an engine via an intake manifold; characterized in that: The fuel tank is connected to the carbon canister via a fuel line, and the carbon canister is connected to the intake manifold via a desorption pipe. The desorption pipe is equipped with a solenoid valve, and the ignition controller controls the solenoid valve.

2. The carburetor motorcycle fuel evaporation system according to claim 1, characterized in that: The oil and gas pipe is connected to a one-way valve via a tee to allow one-way venting to the atmosphere, thereby balancing the gas pressure inside the fuel tank.

3. The carburetor motorcycle fuel evaporation system according to claim 1, characterized in that: The engine is connected to a secondary air supply valve via a secondary air supply pipe. The air filter is connected to the inlet of the secondary air supply valve via a first pipe. The secondary air supply valve is also connected to the air supply pipe via a second pipe.

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