Fuel evaporation control system and control method thereof

Abstract

The invention discloses a fuel evaporation control system and a control method thereof, relates to the technical field of fuel systems of automobiles and motorcycles, and aims at solving the problems that an existing fuel evaporation control system is not high in safety and pollutes the environment, the system comprises a fuel tank, and the fuel tank is provided with a first connecting pipe and a second connecting pipe; the extending-in port of the first connecting pipe is lower than the extending-in port of the second connecting pipe, the fuel tank cover is connected with the fuel tank and the carbon tank, the fuel tank cover connector is connected with the first connecting pipe through a first pipeline, the on-off valve is connected with the fuel tank cover connector and comprises a valve body, the valve body is provided with an air channel, a first connector and a second connector, and the first connector and the second connector are communicated with the air channel. The first connector is connected with a second pipeline, the second connector is connected with a second connecting pipe through a third pipeline, a valve element assembly used for controlling connection and disconnection of the first connector and the second connector is arranged in the air channel, the elastic piece is used for providing pre-tightening force enabling the valve element assembly to move in the direction close to the oil tank cover, and therefore the oil tank cover is safer and more environmentally friendly.

Description

Technical Field

[0001] The present invention relates to the technical field of automobile and motorcycle fuel systems, and more specifically, to a fuel evaporation control system and a control method thereof. Background Art

[0002] The current fuel evaporation control system is mainly composed of a fuel tank, a fuel evaporation rubber hose, a dump valve, a carbon canister, a throttle valve, and an engine. This system is more suitable for external fuel tanks that are completely exposed to the air. For built-in fuel tanks that are completely surrounded by vehicle body covers, the heat dissipation environment is relatively poor and there is a risk of failure of the fuel evaporation control system.

[0003] The main problems are poor heat dissipation in the fuel tank, high pressure in the fuel tank in hot summer weather up to 15Kpa, fuel expansion as temperature and pressure continue to rise, carbon canister oil and gas adsorption saturation can not be completely desorbed to the throttle valve and engine, excess oil and gas from the other side of the carbon canister through the vent wall cooled by wind liquefaction out of the polluted atmosphere. When the engine is turned off and restarted, excessive fuel evaporation causes the mixture air-fuel ratio to be too rich and stays in the throttle valve, making it difficult to start. When the fuel tank cap needs to be opened to add fuel when there is more than one-third of the fuel left in the fuel tank, the high-temperature and high-pressure fuel vaporizes into mist and sprays out instantly, posing a safety risk.

[0004] Therefore, how to solve the problems of low safety and environmental pollution in the existing fuel evaporation control system is an urgent problem to be solved by those skilled in the art. Summary of the invention

[0005] In view of this, the purpose of the present invention is to provide a fuel evaporation control system, which can avoid the safety problem of fuel vaporizing into mist and instantly spraying out from the fuel tank filling port due to the high-temperature and high-pressure fuel evaporation process, and can also avoid excess oil and gas from being cooled by wind and condensed and liquefied from flowing out from the vent wall on the other side of the carbon canister to pollute the atmospheric environment.

[0006] Another object of the present invention is to provide a fuel evaporation control method including the above-mentioned fuel evaporation control system, which is safer and more environmentally friendly.

[0007] In order to achieve the above object, the present invention provides the following technical solutions:

[0008] A fuel evaporation control system, comprising:

[0009] A fuel tank, wherein the fuel tank is provided with a first connecting pipe and a second connecting pipe, wherein an inlet port of the first connecting pipe is lower than an inlet port of the second connecting pipe;

[0010] The fuel tank cap is provided with a fuel tank cap joint connected to the fuel delivery pipe, the fuel delivery pipe is connected to the fuel tank, one side of the fuel tank cap joint is connected to the first connecting pipe through the first pipeline, and the other side of the fuel tank cap joint is connected to the carbon canister through the pipeline;

[0011] The on-off valve is connected to the fuel tank cover joint, and the on-off valve includes a valve body, an air passage extending along the axial direction of the valve body is provided inside the valve body, a first interface and a second interface connected to the air passage are provided on the circumference of the valve body, the first interface is connected to the pipeline through a second pipeline, and the second interface is connected to the second connecting pipe through a third pipeline, and a valve core assembly for controlling the on-off of the first interface and the second interface is provided in the air passage, one end of the valve core assembly is abutted against the fuel tank cover, and the other end of the valve core assembly is connected to an elastic member, and the elastic member is used to provide a pre-tightening force to move the valve core assembly toward the fuel tank cover.

[0012] Preferably, the valve core assembly includes a push rod, which is provided with a first shoulder and a second shoulder, the cavity between the first shoulder and the second shoulder is used to connect the first interface and the second interface, one end of the push rod is abutted against the fuel tank cap, and the other end of the push rod is connected to an elastic member, and the elastic member is used to provide a pre-tightening force to move the push rod toward the fuel tank cap so that the first shoulder blocks the second interface.

[0013] Preferably, an annular groove is provided on the outer periphery of the second shoulder, and two annular grooves are provided on the outer periphery of the first shoulder, and the two annular grooves are respectively provided at two ends of the first shoulder, and a sealing member is provided in the annular groove.

[0014] Preferably, the depth of the first connecting pipe inserted into the inner cavity of the fuel tank and the overlapping depth area of ​​the fuel tank form a first inner cavity volume of 15% of the total volume of the fuel tank, and the inner cavity volume of the oil delivery pipe is 10% of the total volume of the fuel tank.

[0015] Preferably, the depth of the second connecting pipe inserted into the inner cavity of the fuel tank and the volume of the second inner cavity formed by the area with the same overlapping depth as the fuel tank are 5% of the total volume of the fuel tank.

[0016] Preferably, the pipeline includes a fourth pipeline, a tee, a fifth pipeline, and a sixth pipeline, one end of the fourth pipeline is connected to the other side of the fuel tank cap joint, the other end of the fourth pipeline is connected to an interface of the tee, the other two interfaces of the tee are respectively connected to the fifth pipeline and the second pipeline, the fifth pipeline is connected to the dump valve, and the dump valve is connected to the carbon canister through the sixth pipeline.

[0017] Preferably, the carbon canister is connected to the throttle valve via a seventh pipeline, and the throttle valve is connected to the engine.

[0018] Preferably, a one-way valve is provided on the seventh pipeline, and the opening pressure of the one-way valve is greater than the outlet pressure of the carbon canister and less than the absolute value of the negative pressure at the front end of the throttle valve intake.

[0019] Preferably, the sealing members are all rubber rings.

[0020] Preferably, the first connecting pipe and the second connecting pipe are both metal pipes, and the first connecting pipe and the second connecting pipe are welded to the fuel tank as a whole.

[0021] Preferably, the elastic member is a spring.

[0022] A fuel evaporation control method is applied to any one of the above-mentioned fuel evaporation control systems, and the fuel evaporation control method comprises:

[0023] Fill the fuel tank with oil, open the fuel tank cap, and allow the elastic member to push the valve core assembly upward to disconnect the first interface from the second interface, and the air in the fuel tank is discharged through the first connecting pipe, the first pipeline, the fuel tank cap joint, the pipeline and the carbon canister;

[0024] Close the fuel tank cap and push the valve core assembly downward to connect the first interface with the second interface, and the air in the fuel tank is discharged through the second connecting pipe, the third pipeline, the on-off valve, the second pipeline, the pipeline and the carbon canister.

[0025] Preferably, during the process of refueling the fuel tank, the fuel enters the fuel tank through the fuel tank cap joint and the fuel delivery pipe. When the amount of oil flowing into the inner cavity of the fuel tank reaches the insertion port of the first connecting pipe, the insertion port of the first connecting pipe is sealed by the fuel to prevent the air in the inner cavity of the fuel tank from flowing out. The area above the insertion port of the first connecting pipe in the inner cavity of the fuel tank is the remaining air, which is sealed in the upper part of the inner cavity of the fuel tank. Fuel is continued to be added until the fuel fills the inner cavity of the fuel delivery pipe.

[0026] Preferably, after closing the fuel tank cap, the fuel in the fuel pipe cavity flows into the fuel tank under the action of gravity while the air in the fuel tank cavity is discharged through the second connecting pipe, the third pipeline, the on-off valve, the second pipeline, the pipeline and the carbon canister.

[0027] The fuel evaporation control system provided by the present invention includes a fuel tank, a first connecting pipe, a second connecting pipe, a fuel tank cap, a fuel tank cap joint, an oil delivery pipe, a carbon canister and an on-off valve. Specifically, the fuel tank cap is provided with a fuel tank cap joint connected to the oil delivery pipe, and a refueling channel is formed by the fuel tank cap, the fuel tank cap joint, the oil delivery pipe and the fuel tank. When refueling, the fuel flows to the fuel tank through the oil delivery pipe. The fuel tank is provided with a first connecting pipe and a second connecting pipe, and the extension port of the first connecting pipe is lower than the extension port of the second connecting pipe. One side of the fuel tank cap joint is connected to the first connecting pipe through a first pipeline, and the other side of the fuel tank cap joint is connected to the carbon canister through a pipeline, so that the air in the fuel tank can be discharged through the first connecting pipe, the first pipeline, the fuel tank cap joint, the pipeline and the carbon canister in sequence.

[0028] The on-off valve is connected to the fuel tank cap joint. The on-off valve includes a valve body. An air passage extending along the axial direction of the valve body is provided inside the valve body to realize the circulation of gas. A first interface and a second interface communicating with the air passage are provided on the circumference of the valve body. The first interface is connected to the pipeline through the second pipeline, and the second interface is connected to the second connecting pipe through the third pipeline. A valve core assembly for controlling the on-off of the first interface and the second interface is provided in the air passage. The connection state of the second pipeline and the third pipeline is controlled by the valve core assembly. One end of the valve core assembly abuts the fuel tank cap, and the other end of the valve core assembly is connected to an elastic member. The elastic member is used to provide a pre-tightening force to move the valve core assembly in a direction close to the fuel tank cap. When the fuel tank cap is opened, the elastic member pushes the valve core assembly upward to disconnect the first interface from the second interface, so that the second pipeline and the third pipeline are in a disconnected state, so that the air in the fuel tank is blocked in the fuel tank inner cavity and the third pipeline. At this time, the air in the fuel tank inner cavity can only pass through the first connecting pipe, the first pipeline, the fuel tank cap joint and the pipeline in sequence, and finally be discharged from the carbon canister.

[0029] When refueling is completed, the oil delivery pipe is filled with fuel, and the inlet port of the first connecting pipe is sealed by the fuel to prevent air from flowing out of the first connecting pipe. At this time, the fuel tank cap is closed, and the fuel tank cap pushes the valve core assembly downward to compress the elastic member, and at the same time connects the first interface with the second interface, so that the second pipeline and the third pipeline are in a connected state, so that the air in the fuel tank passes through the second connecting pipe, the third pipeline, the second interface, the on-off valve, the first interface, the second pipeline and the pipeline in sequence, and is finally discharged from the carbon canister. While the air in the fuel tank is discharged, space is made for the inner cavity of the fuel tank, and the fuel in the oil delivery pipe flows into the fuel tank under the action of gravity to fill the fuel tank.

[0030] By arranging a first connecting pipe and a second connecting pipe in the inner cavity of the fuel tank, and arranging an oil delivery pipe and an on-off valve on the outside thereof, an effective space volume for the evaporation and expansion of high-temperature and high-pressure fuel is formed, so as to prevent insufficient space for the evaporation and expansion of fuel in high temperature weather, which leads to increased pressure in the fuel tank and causes a large amount of oil and gas to evaporate, and then spray out from the refueling port to cause safety problems, and flow into the carbon canister to be cooled, condensed and liquefied by wind and flow out to cause pollution problems, thereby achieving the goals of safety and environmental protection. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0032] Figure 1 This is a schematic diagram of the structure of the fuel evaporation control system provided by the present invention;

[0033] Figure 2 A cross-sectional view of a fuel tank provided by the present invention;

[0034] Figure 3 A cross-sectional view of the on-off valve provided by the present invention;

[0035] Figure 4 A cross-sectional view of the on-off valve when the fuel tank cover provided by the present invention is opened;

[0036] Figure 5 A cross-sectional view of the on-off valve when the fuel tank cover provided by the present invention is closed;

[0037] Figure 6 This is a step diagram of the fuel evaporation control method provided by the present invention.

[0038] Reference numerals:

[0039] 1-Fuel tank; 2-First connecting pipe; 3-Second connecting pipe; 4-Fuel tank cap; 5-Fuel tank cap joint; 6-Oil delivery pipe; 7-First pipeline; 8-Carbon canister; 9-On / Off valve, 91-Valve body, 92-First interface, 93-Second interface, 94-Elastic member, 95-Push rod, 96-First shoulder, 97-Second shoulder, 98-Seal; 10-Second pipeline; 11-Third pipeline; 12-Fourth pipeline; 13-Tee pipe; 14-Fifth pipeline; 15-Sixth pipeline; 16-Dump valve; 17-Seventh pipeline; 18-Throttle valve; 19-Check valve. DETAILED DESCRIPTION

[0040] 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.

[0041] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0042] It should be noted that the directional words such as "upper" and "lower" mentioned below are defined based on the drawings in the specification.

[0043] The core of the present invention is to provide a fuel evaporation control system, which can avoid the safety problem of fuel vaporizing into mist and instantly spraying out from the fuel filling port of the fuel tank 1 due to the high-temperature and high-pressure fuel evaporation process, and can also prevent excess oil and gas from being cooled by wind and condensed and liquefied from flowing out from the vent hole wall on the other side of the carbon canister 8 to pollute the atmospheric environment. Another core of the present invention is to provide a fuel evaporation control method including the above-mentioned fuel evaporation control system, which is safer and more environmentally friendly.

[0044] Please refer to Figure 1 , Figure 2 and Figure 3 A fuel evaporation control system includes a fuel tank 1, a first connecting pipe 2, a second connecting pipe 3, a fuel tank cap 4, a fuel tank cap joint 5, a fuel delivery pipe 6, a carbon canister 8 and an on-off valve 9.

[0045] Specifically, the fuel tank cap 4 is provided with a fuel tank cap joint 5 connected to the oil delivery pipe 6, and a refueling channel is formed by connecting the fuel tank cap 4, the fuel tank cap joint 5, the oil delivery pipe 6 and the fuel tank 1. When refueling, the fuel flows to the fuel tank 1 through the oil delivery pipe 6. The fuel tank 1 is provided with a first connecting pipe 2 and a second connecting pipe 3, and the insertion port of the first connecting pipe 2 is lower than the insertion port of the second connecting pipe 3. One side of the fuel tank cap joint 5 is connected to the first connecting pipe 2 through a first pipeline 7, and the other side of the fuel tank cap joint 5 is connected to the carbon canister 8 through a pipeline, so that the air in the fuel tank 1 can be discharged through the first connecting pipe 2, the first pipeline 7, the fuel tank cap joint 5, the pipeline and the carbon canister 8 in sequence.

[0046] The on-off valve 9 is connected to the fuel tank cap joint 5. The on-off valve 9 includes a valve body 91. The valve body 91 is provided with an air passage extending along its own axial direction to realize the circulation of gas. The valve body 91 is provided with a first interface 92 and a second interface 93 in communication with the air passage in the circumference. The first interface 92 is connected to the pipeline through the second pipeline 10. The second interface 93 is connected to the second connecting pipe 3 through the third pipeline 11. A valve core component for controlling the on-off of the first interface 92 and the second interface 93 is provided in the air passage. The connection state of the second pipeline 10 and the third pipeline 11 is controlled by the valve core component. One end of the valve core component is connected to the fuel tank cap. 4, and the other end of the valve core assembly is connected to the elastic member 94, which is used to provide a pre-tightening force for moving the valve core assembly toward the fuel tank cap 4. When the fuel tank cap 4 is opened, the elastic member 94 pushes the valve core assembly upward to disconnect the first interface 92 from the second interface 93, so that the second pipeline 10 and the third pipeline 11 are in a disconnected state, so that the air in the fuel tank 1 is blocked in the inner cavity of the fuel tank 1 and the third pipeline 11. At this time, the air in the inner cavity of the fuel tank 1 can only pass through the first connecting pipe 2, the first pipeline 7, the fuel tank cap joint 5 and the pipeline in sequence, and finally be discharged from the carbon canister 8.

[0047] When refueling is completed, the fuel delivery pipe 6 is filled with fuel, and the inlet port of the first connecting pipe 2 is sealed by the fuel to prevent air from flowing out of the first connecting pipe 2. At this time, the fuel tank cap 4 is closed, and the fuel tank cap 4 pushes the valve core assembly downward to compress the elastic member 94, and at the same time, the first interface 92 is connected to the second interface 93, so that the second pipeline 10 and the third pipeline 11 are in a connected state, so that the air in the fuel tank 1 passes through the second connecting pipe 3, the third pipeline 11, the second interface 93, the on-off valve 9, the first interface 92, the second pipeline 10 and the pipeline in sequence, and is finally discharged from the carbon canister 8. While the air in the fuel tank 1 is discharged, space is made for the inner cavity of the fuel tank 1, and the fuel in the fuel delivery pipe 6 flows into the fuel tank 1 under the action of gravity to fill the fuel tank 1.

[0048] By arranging the first connecting pipe 2 and the second connecting pipe 3 in the inner cavity of the fuel tank 1, and arranging the oil delivery pipe 6 and the on-off valve 9 on the outside thereof, an effective space volume for the evaporation and expansion of high-temperature and high-pressure fuel is formed, so as to prevent the insufficient space for the evaporation and expansion of fuel in high temperature weather, which leads to the increase of pressure in the fuel tank 1 and causes a large amount of oil and gas to evaporate, and then spray out from the refueling port to cause safety problems, and flow into the carbon canister 8 to be cooled, condensed and liquefied by wind and flow out to cause pollution problems, thereby achieving the purpose of safety and environmental protection.

[0049] The on-off valve 9 is connected to the fuel tank cap joint 5 by bolts, but in practical applications, there is no limitation to this.

[0050] The fuel evaporation control system arranged in the above manner seals the third pipe 11 and part of the air in the inner cavity of the fuel tank 1 during the process of opening the fuel tank cap 4 for refueling. After the fuel is filled, the third pipe 11 and the air in the inner cavity of the fuel tank 1 are conducted after the fuel tank cap 4 is closed, and the fuel filled in the inner cavity of the oil delivery pipe 6 flows back into the inner cavity of the fuel tank 1 under the action of gravity, and the top of the oil delivery pipe 6 and the inner cavity of the fuel tank 1 are filled with air to form the space volume for the evaporation and expansion of the fuel, thereby solving the problem of fuel evaporation. The structure is simple, easy to produce, and durable and reliable.

[0051] Please refer to Figure 4 and Figure 5 The valve core assembly includes a push rod 95, on which a first shoulder 96 and a second shoulder 97 are provided. The cavity between the first shoulder 96 and the second shoulder 97 is used to connect the first interface 92 and the second interface 93. One end of the push rod 95 abuts against the fuel tank cover 4, and the other end of the push rod 95 is connected to the elastic member 94. The elastic member 94 is used to provide a pre-tightening force to move the push rod 95 in a direction close to the fuel tank cover 4, so that the first shoulder 96 blocks the second interface 93.

[0052] It should be noted that when the fuel tank cap 4 is opened, the push rod 95 moves toward the direction close to the fuel tank cap 4, that is, moves upward under the action of the elastic member 94, so that the first shaft shoulder 96 blocks the second interface 93 to seal the third pipe 11, so that the air in the inner cavity of the fuel tank 1 is blocked in the third pipe 11 and the inner cavity of the fuel tank 1, and will not be discharged through the third pipe 11 and the on-off valve 9. When the fuel tank cap 4 is closed, the fuel tank cap 4 pushes the push rod 95 to move downward, so that the first interface 92 is connected to the second interface 93, so as to conduct the third pipe 11 and the second pipe 10, so that the air in the inner cavity of the fuel tank 1 can be discharged through the third pipe 11, the on-off valve 9 and the second pipe 10.

[0053] In the above case, an annular groove is provided on the outer periphery of the second shoulder 97, and two annular grooves are provided on the outer periphery of the first shoulder 96, and the two annular grooves are respectively provided at both ends of the first shoulder 96, and a seal 98 is provided in the annular groove.

[0054] It can be understood that the three seals 98 are sleeved in the three annular grooves of the shoulder of the push rod 95, and then the push rod 95 is installed in the inner cavity of the valve body 91. The seals 98 are used to seal the shoulder and the inner cavity of the valve body 91 to limit the airflow.

[0055] Furthermore, the first inner cavity volume composed of the first connecting pipe 2 inserted into the inner cavity of the fuel tank 1 and the area of ​​the same depth overlapping the fuel tank 1 is 15% of the total volume of the fuel tank 1, the inner cavity volume of the oil delivery pipe 6 is 10% of the total volume of the fuel tank 1, and the second inner cavity volume composed of the second connecting pipe 3 inserted into the inner cavity of the fuel tank 1 and the area of ​​the same depth overlapping the fuel tank 1 is 5% of the total volume of the fuel tank 1.

[0056] It can be understood that when refueling, when the amount of oil flowing into the inner cavity of the fuel tank 1 reaches the insertion port of the first connecting pipe 2, the insertion port of the first connection is sealed by the fuel to prevent air from flowing out, and the area above the insertion port of the first connecting pipe 2 in the inner cavity of the fuel tank 1 is the remaining air, which is sealed in the upper part of the inner cavity of the fuel tank 1, and the inner cavity of the fuel tank 1 is completely filled with most of the fuel and a small amount of air. When the fuel is continuously refilled, the fuel tank 1 is completely filled with most of the fuel and a small amount of air until the fuel fills the inner cavity of the oil delivery pipe 6 connected to the fuel tank 1. The fuel tank cap 4 is closed, and the airflow in the inner cavity of the fuel tank 1 is connected and discharged through the second connecting pipe 3, the third pipeline 11, the on-off valve 9, and the second pipeline 10. The volume vacated during the process of the airflow in the inner cavity of the fuel tank 1 being discharged to the atmosphere is 15% of the total volume of the fuel tank 1, and the fuel stored in the oil delivery pipe 6 is 10% of the total volume of the fuel tank 1. The volume vacated during the process of the airflow in the inner cavity of the fuel tank 1 being discharged to the atmosphere is filled with most of the air space at the top of the fuel tank 1 by the fuel stored in the oil delivery pipe 6 under the action of its own gravity. Therefore, at this time, 5% of the remaining total volume of the fuel tank 1, that is, the air space at the top of the fuel tank 1, and the 5% of the remaining total volume of the fuel tank 1 and the inner cavity space of the oil delivery pipe 6 are set as the fuel evaporation expansion space and volume of the fuel tank 1.

[0057] On the basis of the above embodiment, the pipeline includes a fourth pipeline 12, a tee pipe 13, a fifth pipeline 14, and a sixth pipeline 15. One end of the fourth pipeline 12 is connected to the other side of the fuel tank cap joint 5, and the other end of the fourth pipeline 12 is connected to an interface of the tee pipe 13. The other two interfaces of the tee pipe 13 are respectively connected to the fifth pipeline 14 and the second pipeline 10. The fifth pipeline 14 is connected to the dump valve 16, and the dump valve 16 is connected to the carbon canister 8 through the sixth pipeline 15.

[0058] It should be noted that when refueling, the fuel tank cap 4 is opened, the elastic member 94 in the on-off valve 9 pushes the push rod 95 to move upward, the first shaft shoulder 96 of the push rod 95 seals the airflow entering from the lower end of the valve body 91, and the sealing member 98 on the second shaft shoulder 97 seals the airflow entering from the upper end of the push rod 95, the internal air passage of the on-off valve 9 is closed, and the air in the inner cavity of the fuel tank 1 passes through the second connecting pipe 3 and the third pipeline 11 and is blocked by the on-off valve 9 in the inner cavity of the fuel tank 1 and the third pipeline 11. During the process of injecting fuel from the pipe opening of the fuel tank cap 4, the air blocked in the inner cavity of the fuel tank 1 is gradually discharged from the first connecting pipe 2, the first pipeline 7, the fuel tank cap 4, the fourth pipeline 12, the three-way pipe 13, the fifth pipeline 14, the dumping valve 16, the sixth pipeline 15, and the air hole of the carbon canister 8. When the amount of oil flowing into the inner cavity of the fuel tank 1 reaches the insertion port of the first connecting pipe 2, the insertion port of the first connecting pipe 2 is sealed by the fuel to prevent air from flowing out, the area above the insertion port of the first connecting pipe 2 in the inner cavity of the fuel tank 1 is the remaining air, which is sealed in the upper part of the inner cavity of the fuel tank 1, and the inner cavity of the fuel tank 1 is completely filled with most of the fuel and a small amount of air. The volume of the inner cavity of the oil delivery pipe 6 is 5% of the total volume of the fuel tank 1, that is, the remaining top air space of the fuel tank 1 is the expansion amount after the amount of fuel injected into the inner cavity of the fuel tank 1. When the fuel is continuously added from the fuel tank 1 port, the fuel tank 1 is completely filled with most of the fuel and a small amount of air until the fuel fills the inner cavity of the oil delivery pipe 6 connected to the fuel tank 1. When the fuel in the inner cavity of the oil delivery pipe 6 is filled with fuel, the refueling gun jumps and the user can visually judge that the fuel is full.

[0059] The fuel tank cover 4 is closed, and the fuel tank cover 4 pushes the push rod 95 downward to compress the elastic member 94. When the fuel tank cover 4 is completely closed, the cavity between the two shaft shoulders of the push rod 95 forms a clearance match with the inner cavity of the valve body 91, and the cavity gap between the first shaft shoulder 96 and the second shaft shoulder 97 forms an air flow channel with the third pipe 11 and the second pipe 10. The airflow in the inner cavity of the fuel tank 1 is gradually discharged to the atmosphere from the second connecting pipe 3, the third pipe 11, the on-off valve 9, the second pipe 10, the three-way pipe 13, the fifth pipe 14, the dumping valve 16, the sixth pipe 15 and the air hole of the carbon canister 8 in sequence; the volume of the fuel tank 1 vacated during the process of the airflow in the inner cavity of the fuel tank 1 being discharged to the atmosphere is completely filled by the fuel in the inner cavity of the oil delivery pipe 6 under the action of gravity, and the volume of the inner cavity of the oil delivery pipe 6 and 5% of the total volume of the fuel tank 1, that is, the remaining air space at the top of the fuel tank 1 is set as the evaporation expansion space and volume of the fuel in the fuel tank 1.

[0060] The inner cavity of the fuel tank 1 is provided with a first connecting pipe 2, a second connecting pipe 3, and the outer portion is provided with an oil delivery pipe 6 which cooperates with an on-off valve 9 to form an effective space volume for the evaporation and expansion of high-temperature and high-pressure fuel, thereby preventing a large amount of oil and gas from evaporating and flowing into the carbon canister 8 due to insufficient space for fuel evaporation and expansion in hot weather, and completely solving the safety problem of the fuel vaporizing into mist and instantly spraying out from the fuel filling port of the fuel tank 1 during the evaporation process of the high-temperature and high-pressure fuel, and the problem of excess oil and gas being cooled by wind and condensed and liquefied from the vent wall on the other side of the carbon canister 8, thereby polluting the atmospheric environment.

[0061] In the above embodiment, the carbon canister 8 is connected to the throttle valve 18 through the seventh pipe 17, and the throttle valve 18 is connected to the engine.

[0062] It can be understood that by providing the throttle valve 18 , the oil and gas flow from the carbon canister 8 to the engine can be controlled.

[0063] As a preferred embodiment, a one-way valve 19 is provided on the seventh pipeline 17 , and the opening pressure of the one-way valve 19 is greater than the outlet pressure of the carbon canister 8 and less than the absolute value of the negative pressure at the front end of the intake of the throttle valve 18 .

[0064] It should be noted that when riding for a period of time in hot weather, the carbon canister 8 adsorbs the fuel evaporated gas mixture and the air-fuel mixture is relatively thick. After the vehicle is turned off, when it is started again, due to the negative pressure at the front end of the throttle valve 18, the excessively concentrated fuel evaporated gas mixture enters, causing difficulty in starting the engine. Therefore, a one-way valve 19 is provided between the carbon canister 8 and the throttle valve 18. The setting pressure of the one-way valve 19 is both greater than the pressure at the pipe mouth of the carbon canister 8 and less than the absolute value of the negative pressure at the front end of the throttle valve 18. The one-way valve 19 prevents the excessively concentrated fuel evaporated gas mixture from entering the throttle valve 18 and the engine. The setting pressure of the one-way valve 19 is less than the absolute value of the negative pressure at the front end of the throttle valve 18 to ensure that the fuel evaporated gas mixture is completely desorbed to the engine fuel to do work, so as to solve the problem of difficulty in starting.

[0065] In the above cases, the sealing members 98 are all rubber rings.

[0066] It is understandable that the sealing member 98 may be a rubber ring, but in practical applications, it may also be other structures, which is not limited to this.

[0067] In the above embodiment, the first connecting pipe 2 and the second connecting pipe 3 are both metal pipes, and the first connecting pipe 2 and the second connecting pipe 3 are both welded to the fuel tank 1 as a whole.

[0068] It should be noted that the first connecting pipe 2, the second connecting pipe 3 and the fuel tank 1 are welded and fused into one.

[0069] In the above embodiment, the elastic member 94 is a spring.

[0070] It can be understood that in this embodiment, the elastic member 94 is preferably a spring, but in actual applications, it can also be set to other structures, which is not limited to this.

[0071] Please refer to Figure 6 A fuel evaporation control method is applied to the above-mentioned fuel evaporation control system, and the fuel evaporation control method includes:

[0072] Step S1, refuel the fuel tank 1, open the fuel tank cap 4, and make the elastic member 94 push the valve core assembly upward to disconnect the first interface 92 from the second interface 93, and the air in the fuel tank 1 is discharged through the first connecting pipe 2, the first pipeline 7, the fuel tank cap joint 5, the pipeline and the carbon canister 8;

[0073] Step S2, close the fuel tank cap 4, push the valve core assembly downward to connect the first interface 92 with the second interface 93, and discharge the air in the fuel tank 1 through the second connecting pipe 3, the third pipeline 11, the on-off valve 9, the second pipeline 10, the pipeline and the carbon canister 8.

[0074] It should be noted that when the fuel tank cap 4 is opened, the valve core assembly moves toward the direction close to the fuel tank cap 4 under the action of the elastic member 94, that is, moves upward, so that the first interface 92 is disconnected from the second interface 93, so that the air in the inner cavity of the fuel tank 1 is blocked in the third pipe 11 and the inner cavity of the fuel tank 1, and will not be discharged through the third pipe 11 and the on-off valve 9. At the same time, the air in the fuel tank 1 can be discharged through the first connecting pipe 2, the first pipe 7, the fuel tank cap joint 5, the pipeline and the carbon canister 8; when the fuel tank cap 4 is closed, the fuel tank cap 4 pushes the valve core assembly to move downward, so that the first interface 92 is connected to the second interface 93, so as to conduct the third pipeline 11 and the second pipeline 10, so that the air in the inner cavity of the fuel tank 1 can be discharged through the second connecting pipe 3, the third pipeline 11, the on-off valve 9, the second pipeline 10, the pipeline and the carbon canister 8.

[0075] On the basis of the above embodiment, during the process of refueling the fuel tank 1, the fuel enters the fuel tank 1 through the fuel tank cap joint 5 and the fuel delivery pipe 6. When the amount of oil flowing into the inner cavity of the fuel tank 1 reaches the insertion port of the first connecting pipe 2, the insertion port of the first connecting pipe 2 is sealed by the fuel to prevent the air in the inner cavity of the fuel tank 1 from flowing out. The area above the insertion port of the first connecting pipe 2 in the inner cavity of the fuel tank 1 is the remaining air, which is sealed in the upper part of the inner cavity of the fuel tank 1. Fuel is continuously added until the fuel fills the inner cavity of the fuel delivery pipe 6.

[0076] Furthermore, after closing the fuel tank cap 4, during the process in which the air in the inner cavity of the fuel tank 1 is discharged through the second connecting pipe 3, the third pipeline 11, the on-off valve 9, the second pipeline 10, the pipeline and the carbon canister 8, the fuel in the inner cavity of the oil delivery pipe 6 all flows into the fuel tank 1 under the action of gravity. At this time, the volume of the inner cavity of the oil delivery pipe 6 and 5% of the total volume of the fuel tank 1, that is, the remaining top air space of the fuel tank 1 is set as the evaporation expansion space and volume of the fuel in the fuel tank 1.

[0077] In summary, the fuel evaporation control system provided by the present invention completely solves the safety problem that the fuel vaporizes into mist and instantly sprays out from the fuel filling port of the fuel tank 1 due to the high-temperature and high-pressure fuel evaporation process, and the problem that excess oil and gas are cooled by wind and condensed and liquefied from the vent hole wall on the other side of the carbon canister 8, polluting the atmospheric environment. It also completely solves the problem that the air-fuel ratio of the mixed gas is too rich and is retained in the throttle valve 18 due to excessive fuel evaporation, which makes it difficult to start.

[0078] It should be noted that, in this specification, relational terms such as first and second are merely used to distinguish one entity from other entities, but do not necessarily require or imply any actual relationship or order between these entities.

[0079] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0080] The above is a detailed introduction to a fuel evaporation control system and a control method thereof provided by the present invention. This article uses specific examples to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method and core ideas of the present invention. It should be pointed out that for ordinary technicians in this technical field, without departing from the principles of the present invention, the present invention can also be improved and modified in a number of ways, and these improvements and modifications also fall within the scope of protection of the claims of the present invention.

Claims

1. A fuel evaporation control system, characterized in that: include: A fuel tank (1), the fuel tank (1) being provided with a first connecting pipe (2) and a second connecting pipe (3), the inlet port of the first connecting pipe (2) being lower than the inlet port of the second connecting pipe (3); A fuel tank cap (4) is provided with a fuel tank cap joint (5) connected to a fuel delivery pipe (6), wherein the fuel delivery pipe (6) is connected to the fuel tank (1), one side of the fuel tank cap joint (5) is connected to the first connecting pipe (2) via a first pipeline (7), and the other side of the fuel tank cap joint (5) is connected to a carbon canister (8) via a pipeline; An on-off valve (9) is connected to the fuel tank cover joint (5), the on-off valve (9) comprising a valve body (91), an air passage extending along the axial direction of the valve body (91) is provided inside the valve body (91), a first interface (92) and a second interface (93) in communication with the air passage are provided around the valve body (91), the first interface (92) is connected to the pipeline via a second pipeline (10), the second interface (93) is connected to the second connecting pipe (3) via a third pipeline (11), a valve core assembly for controlling the on-off of the first interface (92) and the second interface (93) is provided in the air passage, one end of the valve core assembly is in contact with the fuel tank cover (4), the other end of the valve core assembly is connected to an elastic member (94), the elastic member (94) is used to provide a preload force for moving the valve core assembly in a direction close to the fuel tank cover (4).

2. The fuel evaporation control system according to claim 1, characterized in that: The valve core assembly comprises a push rod (95), the push rod (95) being provided with a first shaft shoulder (96) and a second shaft shoulder (97), the cavity between the first shaft shoulder (96) and the second shaft shoulder (97) being used to connect the first interface (92) and the second interface (93), one end of the push rod (95) being in contact with the fuel tank cover (4), the other end of the push rod (95) being connected to the elastic member (94), the elastic member (94) being used to provide a pre-tightening force for moving the push rod (95) in a direction close to the fuel tank cover (4), so that the first shaft shoulder (96) blocks the second interface (93).

3. The fuel evaporation control system according to claim 2, characterized in that: An annular groove is provided on the outer periphery of the second shaft shoulder (97), two annular grooves are provided on the outer periphery of the first shaft shoulder (96), and the two annular grooves are respectively provided at two ends of the first shaft shoulder (96), and a sealing member (98) is provided in the annular groove.

4. The fuel evaporation control system according to claim 1, characterized in that: The depth of the first connecting pipe (2) inserted into the inner cavity of the fuel tank (1) and the overlapping area of ​​the fuel tank (1) with the same depth as the inner cavity volume of the first inner cavity are 15% of the total volume of the fuel tank (1), and the inner cavity volume of the oil delivery pipe (6) is 10% of the total volume of the fuel tank (1).

5. The fuel evaporation control system according to claim 4, characterized in that: The depth of the second connecting pipe (3) inserted into the inner cavity of the fuel tank (1) and the overlapping area of ​​the fuel tank (1) with the same depth as the inner cavity volume of the second inner cavity are 5% of the total volume of the fuel tank (1).

6. The fuel evaporation control system according to claim 1, characterized in that: The pipeline comprises a fourth pipeline (12), a three-way pipe (13), a fifth pipeline (14), and a sixth pipeline (15); one end of the fourth pipeline (12) is connected to the other side of the fuel tank cap joint (5); the other end of the fourth pipeline (12) is connected to an interface of the three-way pipe (13); the other two interfaces of the three-way pipe (13) are respectively connected to the fifth pipeline (14) and the second pipeline (10); the fifth pipeline (14) is connected to a dump valve (16); and the dump valve (16) is connected to the carbon canister (8) through the sixth pipeline (15).

7. The fuel evaporation control system according to claim 6, characterized in that: The carbon canister (8) is connected to a throttle valve (18) via a seventh pipe (17), and the throttle valve (18) is connected to an engine.

8. The fuel evaporation control system according to claim 7, characterized in that: The seventh pipeline (17) is provided with a one-way valve (19), wherein the opening pressure of the one-way valve (19) is greater than the outlet pressure of the carbon canister (8) and less than the absolute value of the negative pressure at the front end of the intake of the throttle valve (18).

9. The fuel evaporation control system according to claim 3, characterized in that: The sealing elements (98) are all rubber rings.

10. The fuel evaporation control system according to any one of claims 1 to 8, characterized in that: The first connecting pipe (2) and the second connecting pipe (3) are both metal pipes, and the first connecting pipe (2) and the second connecting pipe (3) are welded to the fuel tank (1) as a whole.

11. The fuel evaporation control system according to any one of claims 1 to 8, characterized in that: The elastic member (94) is a spring.

12. A fuel evaporation control method, applied to the fuel evaporation control system according to any one of claims 1 to 11, characterized in that: The fuel evaporation control method comprises: Refuel the fuel tank (1), open the fuel tank cap (4), and allow the elastic member (94) to push the valve core assembly upward, so that the first interface (92) is disconnected from the second interface (93), and the air in the fuel tank (1) is discharged through the first connecting pipe (2), the first pipeline (7), the fuel tank cap joint (5), the pipeline and the carbon canister (8); The fuel tank cover (4) is closed and the valve core assembly is pushed downward to allow the first interface (92) to communicate with the second interface (93), and the air in the fuel tank (1) is discharged through the second connecting pipe (3), the third pipeline (11), the on-off valve (9), the second pipeline (10), the pipeline and the carbon canister (8).

13. The fuel evaporation control method according to claim 12, characterized in that: During the process of refueling the fuel tank (1), the fuel enters the fuel tank (1) through the fuel tank cap joint (5) and the fuel delivery pipe (6). When the amount of oil flowing into the inner cavity of the fuel tank (1) reaches the insertion port of the first connecting pipe (2), the insertion port of the first connecting pipe (2) is sealed by the fuel to prevent the air in the inner cavity of the fuel tank (1) from flowing out. The area above the insertion port of the first connecting pipe (2) in the inner cavity of the fuel tank (1) is the remaining air, which is sealed at the upper part of the inner cavity of the fuel tank (1). Fuel is continuously added until the fuel fills the inner cavity of the fuel delivery pipe (6).

14. The fuel evaporation control method according to claim 12, characterized in that: After the fuel tank cap (4) is closed, the air in the inner cavity of the fuel tank (1) is discharged through the second connecting pipe (3), the third pipe (11), the on-off valve (9), the second pipe (10), the pipeline and the carbon canister (8), while the fuel in the inner cavity of the oil delivery pipe (6) all flows into the fuel tank (1) under the action of gravity.

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