CN202431402U - Fuel evaporation control system - Google Patents

Abstract

The utility model relates to a novel fuel evaporation control system. The novel fuel evaporation control system comprises an oil tank 1, an oil tank connecting pipe 2, a pressure retaining valve 3, a dumping valve connecting pipe 4, a dumping valve 5, an evaporation connecting pipe 6, a carbon tank 7, a desorbing pipe 8, a negative pressure control pipe 9, a ventilating rubber hose 10, an air filter, a carburetor 12 and an engine 13. The control system has the advantages that a vehicle can be guaranteed to pass the fuel evaporation rule test smoothly, simultaneously the problem of over-high cost of the fuel evaporation control system is effectively solved, the requirement for the working capability of a carbon tank in absorbing gasoline is reduced, and the optimal bed volume of the carbon tank or the carbon powder with higher performance cost can be obtained, so that the cost of the control system can be reduced to be lowest.

Description

A fuel evaporation control system

technical field

The utility model relates to a fuel evaporation control system, which can not only meet the requirements of the standard "Limits and Measurement Methods of Fuel Evaporation Pollutants of Motorcycles and Mopeds" (GB20998-2007), but also reduce the adsorption of carbon tanks by vehicles. To meet the requirements of gasoline working capacity, obtain the best carbon tank bed volume and cost-effective carbon powder, so that the installation cost and purchase cost of the entire system can be minimized, which has a great cost advantage.

Background technique

From July 1, 2008, the country began to implement the "Motorcycle and Moped Fuel Evaporative Pollutant Emission Limits and Measurement Methods" (GB20998-2007). At present, motorcycle manufacturers use activated carbon tanks to absorb the fuel vapor in the fuel tank. When the motorcycle is stationary, the fuel vapor formed in the fuel tank enters the carbon tank through the vent pipe of the fuel tank, and the fuel vapor is stored by using the adsorption capacity of activated carbon; the vehicle is running At this time, the gasoline vapor in the canister is sucked into the engine to participate in combustion. In addition, the carbon tank can also balance the effect of the air pressure inside and outside the fuel tank, so as to ensure that the negative pressure in the fuel tank will not form and cause poor fuel supply.

When the motorcycle is stationary, the fuel vapor inside the fuel tank continuously enters the inside of the carbon canister. When the outside temperature is high, the evaporation of the fuel tank becomes larger and larger, which puts forward higher requirements on the capacity of the canister to absorb gasoline. At present, motorcycle companies generally use one of the following two measures to improve the gasoline adsorption capacity of the carbon canister.

1. Keep the type of carbon powder unchanged and increase the volume of the carbon tank bed

Although increasing the volume of the canister bed improves the ability of the canister to absorb gasoline, the quality of the carbon powder also increases, which leads to an increase in the purchase cost of the carbon powder. In addition, the larger volume of the canister also brings difficulties to the installation of the vehicle. Even the interfering parts have to be remodeled, resulting in increased costs.

2. Keep the volume of the carbon tank bed unchanged, and replace the carbon powder with stronger adsorption capacity

Replacing the carbon powder with stronger gasoline adsorption ability can effectively improve the gasoline adsorption capacity of the carbon canister, but the purchase cost of carbon powder will increase several times.

Although the above two measures can meet the requirements of regulations, they make enterprises bear the pressure of rising costs and lose the competitiveness of cost advantages.

Utility model content

The purpose of the utility model is to provide a fuel evaporation control system, which can not only meet the vehicle fuel evaporation regulations test, but also reduce the vehicle's requirements on the ability of the carbon tank to absorb gasoline, and obtain the best carbon tank bed volume and cost-effective carbon powder , so that the installation cost and procurement cost of the entire system are minimized, and it has a great cost advantage.

The purpose of this utility model can be achieved through the following technical measures, including fuel tank, fuel tank connecting pipe, pressure maintaining valve, dump valve connecting pipe, dump valve, evaporation connecting pipe, carbon tank, desorption pipe, negative pressure control pipe, ventilation rubber hose, Carburetor, engine. One end of the pressure maintaining valve is connected to the fuel tank through the fuel tank connecting pipe, and the other end is connected to the dump valve; the dump valve is connected to the adsorption port of the carbon tank through the evaporation connecting pipe; the desorption port of the carbon tank is connected to the carburetor through the desorption tube, the negative pressure control tube One end of the carburetor is connected to the engine through the intake pipe, and the other end is connected to the air filter; the vent hose is connected to the vent hole of the carbon tank.

In the "Motorcycle and Moped Fuel Evaporative Pollutant Emission Limits and Measurement Methods" (GB20998-2007) standard, the ventilation requirements of the fuel evaporation control system are stipulated, and the whole system is specified at (3.63±0.10) kPa relative pressure After using the compressed air, the internal pressure of the fuel supply system should drop below 0.98kPa within 30s to 2min. Therefore, this control system stipulates that the opening pressure of one end of the pressure-holding valve connected to the fuel tank is ≤3.6kPa, and the end connected with the tipping valve connecting pipe communicates with the atmosphere through the vent hole of the carbon tank and the vent hose to ensure that the fuel tank communicates with the atmosphere. When the motorcycle is stationary, the fuel volatilizes to produce fuel vapor, and a positive pressure is formed inside the fuel tank. If the relative pressure at this time is ≤3.6kPa, the end of the pressure-holding valve connected to the fuel tank does not operate, and the fuel vapor cannot enter the carbon tank. When the relative pressure inside the fuel tank When it is greater than 3.6kPa, the pressure-holding valve starts to operate, and the fuel vapor enters the carbon tank through the fuel tank connecting pipe, pressure-holding valve, dump valve connecting pipe, dump valve, and evaporation connecting pipe, and is absorbed into the surface pores of the carbon powder. After the fuel vapor enters the canister, the relative pressure inside the fuel tank begins to drop. If the relative pressure drops below 3.6kPa, the pressure-holding valve starts to close, and the fuel vapor cannot pass through the pressure-holding valve. Repeat this process to restrict part of the fuel vapor inside the fuel tank. , so as to effectively reduce the requirements for the working capacity of the carbon canister to absorb gasoline, obtain the optimal bed volume of the canister or carbon powder with higher cost performance, and minimize the cost of the control system. In addition, in the standard "Safety Performance Requirements and Test Methods for Fuel Tanks of Motorcycles and Mopeds" (GB 19482-2004), it is stipulated that the fuel tank must pass the leakage-tightness test with a relative pressure of 30kPa, so when the positive pressure inside the fuel tank is 3.6 kPa, there will be no fuel vapor leakage in the fuel tank.

When the motorcycle is running, the fuel vapor in the carbon tank is desorbed into the carburetor to participate in combustion, and at the same time, the fuel tank has a negative pressure, and the air enters from the vent hose, the vent hole of the carbon tank, the carbon tank, the dump valve and the pressure maintaining valve. Fuel tank, to ensure that the negative pressure in the fuel tank will not cause poor fuel supply.

Description of drawings

Figure 1 is a structural diagram of the fuel evaporation control system of the utility model. the

Detailed ways

Referring to Fig. 1, a fuel evaporation control system includes a fuel tank 1, a fuel tank connecting pipe 2, a dump valve connecting pipe 4, a dump valve 5, an evaporation connecting pipe 6, a carbon tank 7, a desorption pipe 8, a negative pressure control pipe 9, Vent rubber hose 10, air filter 11, carburetor 12, engine 13, and a pressure maintaining valve 3 is arranged between the fuel tank connecting pipe 2 and the dump valve connecting pipe 4, that is, the vent pipe of the fuel tank 1 passes through the fuel tank connecting pipe 2 and the maintenance valve. One end of the pressure valve 3 is connected, the other end of the pressure maintaining valve 3 is connected to one end of the dump valve 5 through the tipping valve connecting pipe 4, the other end of the tipping valve 5 is connected to the adsorption port of the carbon tank 7 through the evaporation connecting tube 6, and the desorption port of the carbon tank 7 passes through The desorption pipe 8 and the negative pressure control pipe 9 are connected to the desorption port of the carburetor 12, and the carburetor 12 is connected to the engine 13 through the intake pipe at one end, and the air filter 11 at the other end; the canister 7 vent hose 10 is connected to the atmosphere connected.

The opening pressure of the end of the pressure maintaining valve 3 connected to the fuel tank 1 is ≤3.6kPa, and the end of the carbon tank 7 connected through the dump valve connecting pipe 4, the dump valve 5, and the evaporation connecting pipe 6 communicates with the atmosphere through the vent hose 10.

When a positive pressure is generated inside the fuel tank 1, if the relative pressure is greater than 3.6kPa at this time, the fuel vapor inside the fuel tank 1 enters through the fuel tank connecting pipe 2, the pressure maintaining valve 3, the tipping valve connecting pipe 4, the tipping valve 5, and the evaporation connecting pipe 6 For the carbon tank 7, as the fuel vapor inside the fuel tank 1 decreases, the internal relative pressure also decreases. If the relative pressure inside the fuel tank 1 is ≤3.6kPa at this time, the pressure-holding valve 3 starts to close, and the fuel vapor is restricted inside the fuel tank 1. If The fuel oil continues to volatilize, and the relative pressure begins to rise. If it is greater than 3.6kPa, the pressure-holding valve 3 starts to act, and so on, which can effectively prevent a part of fuel vapor from entering the carbon tank 7. When the engine 13 is running, the fuel vapor absorbed by the canister 7 enters the carburetor 12, and the engine 13 participates in combustion. At this time, there is a negative pressure inside the fuel tank 1, and the air enters the inside of the fuel tank 1 from the vent hose 10, the evaporation connecting pipe 6, the tipping valve 5, the tipping valve connecting pipe 4, the pressure maintaining valve 3, and the fuel tank connecting pipe 2 to ensure that the fuel tank 1 will not form a negative pressure and cause poor oil supply. The evaporation control system can effectively reduce the requirement of the fuel tank of the vehicle on the working capacity of the carbon canister to absorb gasoline, and can obtain the optimal bed volume of the canister or carbon powder with higher cost performance, so that the cost of the control system can be minimized.

Claims (2)

1. fuel evaporation control system; Comprise fuel tank (1), fuel tank connecting tube (2), Tipping valve connecting tube (4), Tipping valve (5), evaporation connecting tube (6), charcoal jar (7), desorption pipe (8), negative pressure control valve (9), ventilating glue tube (10), empty filter (11), Carburetor (12), motor (13), it is characterized in that: between said fuel tank connecting tube (2) and Tipping valve connecting tube (4), be provided with pressure retaining valve (3).

2. a kind of fuel evaporation control system according to claim 1; It is characterized in that: the end cracking pressure≤3.6kPa that described pressure retaining valve (3) is connected with fuel tank (1), and charcoal jar (7) one end ventilating glue tube (10) and the atmosphere that connect through Tipping valve connecting tube (4), Tipping valve (5), evaporation connecting tube (6).

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