A fuel tank isolation valve

Abstract

The present invention relates to the technical field of isolation valves, and specifically to a fuel tank isolation valve. A fuel tank isolation valve comprises an isolation valve housing, a solenoid valve, an upper cover, a lower cover, a spring, and a diaphragm, and is characterized in that: connecting pipes are respectively provided at the left and right ends of the isolation valve housing, and a plurality of umbrella-shaped valves are connected to the upper end of the isolation valve housing; a diaphragm is provided above the isolation valve housing, and the upper part of the diaphragm is connected to the upper cover through a spring; the lower part of the isolation valve housing is connected to the lower cover through an overpressure / negative pressure safety valve module; one end of the solenoid valve is embedded in one side of the isolation valve housing, and the other end of the solenoid valve is connected to the solenoid valve cover. Compared with the prior art, a fuel tank isolation valve is provided, which cooperates with a hybrid vehicle to provide the overall performance of the hybrid vehicle.

Description

Technical Field

[0001] The invention relates to the technical field of isolation valves, in particular to an oil tank isolation valve. Background Art

[0002] The fuel tank isolation valve is used between the high-pressure fuel tank and the carbon canister of a hybrid vehicle. One side is connected to the exhaust system in the fuel tank, and the other side is connected to the carbon canister. It is driven by an electrical signal to exchange with the atmosphere and balance the pressure in the fuel tank. However, there are only isolation valve structures for ordinary vehicles on the market, but no isolation valve structures for hybrid vehicles, which makes the performance of hybrid vehicles fail to meet customer requirements. Summary of the invention

[0003] In order to overcome the deficiencies of the prior art, the present invention provides a fuel tank isolation valve which cooperates with a hybrid electric vehicle to improve the overall performance of the hybrid electric vehicle.

[0004] In order to achieve the above-mentioned purpose, a fuel tank isolation valve is designed, including an isolation valve housing, a solenoid valve, an upper cover, a lower cover, a spring, and a diaphragm, and its characteristics are: connecting pipes are respectively provided at the left and right ends of the isolation valve housing, and a plurality of umbrella valves are connected to the upper end of the isolation valve housing; a diaphragm is provided above the isolation valve housing, and the upper part of the diaphragm is connected to the upper cover through a spring; the lower part of the isolation valve housing is connected to the lower cover through an overpressure / negative pressure safety valve module; one end of the solenoid valve is embedded in one side of the isolation valve housing, and the other end of the solenoid valve is connected to the solenoid valve cover.

[0005] The overpressure / negative pressure safety valve module includes a sealing pin, a sealing gasket, a base, a negative pressure spring, a fixing seat, and a high-pressure spring. The top of the base is connected to the sealing pin through a sealing gasket; the bottom of the base is connected to the fixing seat through a negative pressure spring, and a high-pressure spring is provided on the outside of the negative pressure spring and the fixing seat.

[0006] The lower part of the sealing nail is embedded in the base.

[0007] The top of the negative pressure spring abuts against the bottom of the base, and the bottom of the negative pressure spring abuts against the top of the fixing seat.

[0008] The top of the high-pressure spring abuts against the bottom of the base, and the bottom of the high-pressure spring abuts against the top groove of the lower cover.

[0009] An O-ring is arranged between one end of the solenoid valve and the housing of the isolation valve.

[0010] The top of the spring abuts against the bottom of the upper cover, and the bottom of the spring abuts against the inner groove of the upper end of the diaphragm.

[0011] One end of the isolation valve housing is connected to the oil tank, and the other end of the isolation valve housing is connected to the carbon canister.

[0012] The number of the umbrella-shaped valves is at least 4.

[0013] Compared with the prior art, the present invention provides a fuel tank isolation valve which cooperates with a hybrid electric vehicle to improve the overall performance of the hybrid electric vehicle.

[0014] Due to battery drive, the fuel tank of a hybrid vehicle may not be in operation for a long time. At this time, the fuel tank isolation valve is closed, which is needed to prevent the fuel from evaporating from the fuel tank to the atmosphere.

[0015] When the fuel pressure inside the fuel tank increases or decreases with the temperature, the tank isolation valve must be opened in time when the tank pressure sensor identifies the limit pressure in the high-pressure tank, so as to release the overpressure / negative pressure inside the high-pressure tank. When the pressure sensor is not working, the tank isolation valve has the function of actively releasing the overpressure / negative pressure.

[0016] Before each refueling, the high-pressure fuel tank must release the internal pressure of the tank in time by opening the fuel isolation valve after receiving the refueling signal. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of the structure of the present invention.

[0018] Figure 2 This is a schematic diagram of the overpressure / negative pressure safety valve module structure.

[0019] Figure 3 , Figure 4 This is a schematic diagram of the overpressure opening principle of the present invention.

[0020] Figure 5 , Figure 6 It is a schematic diagram of the negative pressure opening principle of the present invention.

[0021] Figures 7 to 9 This is a schematic diagram of the working principle of the overpressure / negative pressure safety valve module.

[0022] See also Figures 1 to 3 , 1 is the upper cover, 2 is the spring, 3 is the diaphragm, 4 is the umbrella valve, 5 is the isolation valve housing, 6 is the O-ring, 7 is the solenoid valve, 8 is the solenoid valve cover, 9 is the lower cover, 10 is the overpressure / negative pressure safety valve module, 10-1 is the sealing pin, 10-2 is the sealing gasket, 10-3 is the base, 10-4 is the negative pressure spring, 10-5 is the fixing seat, and 10-6 is the high pressure spring. DETAILED DESCRIPTION

[0023] The present invention will be further described below with reference to the accompanying drawings.

[0024] like Figure 1 , Figure 2As shown, connecting pipes are respectively provided at the left and right ends of the isolation valve housing 5, and a plurality of umbrella valves 4 are connected to the upper end of the isolation valve housing 5; a diaphragm 3 is provided above the isolation valve housing 5, and the upper part of the diaphragm 3 is connected to the upper cover 1 through a spring 2; the lower part of the isolation valve housing 5 is connected to the lower cover 9 through an overpressure / negative pressure safety valve module 10; one end of the solenoid valve 7 is embedded on one side of the isolation valve housing 5, and the other end of the solenoid valve 7 is connected to the solenoid valve cover 8.

[0025] The overpressure / negative pressure safety valve module 10 includes a sealing pin, a sealing gasket, a base, a negative pressure spring, a fixed seat, and a high-pressure spring. The top of the base 10-3 is connected to the sealing pin 10-1 through a sealing gasket 10-2; the bottom of the base 10-3 is connected to the fixed seat 10-5 through a negative pressure spring 10-4, and a high-pressure spring 10-6 is provided on the outer side of the negative pressure spring 10-4 and the fixed seat 10-5.

[0026] The lower part of the sealing pin 10-1 is embedded in the base 10-3.

[0027] The top of the negative pressure spring 10 - 4 abuts against the bottom of the base 10 - 3 , and the bottom of the negative pressure spring 10 - 4 abuts against the top of the fixing seat 10 - 5 .

[0028] The top of the high-pressure spring 10 - 6 abuts against the bottom of the base 10 - 3 , and the bottom of the high-pressure spring 10 - 6 abuts against the top groove of the lower cover 9 .

[0029] An O-ring 6 is provided between one end of the solenoid valve 7 and the isolation valve housing 5 .

[0030] The top of the spring 2 abuts against the bottom of the upper cover 1 , and the bottom of the spring 2 abuts against the inner groove of the upper end of the diaphragm 3 .

[0031] One end of the isolation valve housing 5 is connected to the oil tank, and the other end of the isolation valve housing 5 is connected to the carbon canister.

[0032] At least four umbrella valves 4 are provided.

[0033] like Figure 1 As shown, after the four umbrella valves 4 are installed in the isolation valve housing 5, the diaphragm 3 is installed in the corresponding slot of the isolation valve housing 5, and then the spring 2 is installed along the diaphragm 3 and the fixing ribs of the upper cover 1, and then the upper cover 1 and the isolation valve housing 5 are laser welded. The installed overpressure / negative pressure safety valve module 10 is installed between the isolation valve housing 5 and the lower cover 9 at the lower part, and then the lower cover 9 and the isolation valve housing 5 are laser welded. Finally, the O-ring 6 is installed on the solenoid valve 7, installed in the isolation valve housing 5, and finally the solenoid valve cover 8 is covered.

[0034] like Figure 2As shown, after the sealing gasket 10-2 is installed on the base 10-3, the sealing nail 10-1 is passed downward from the sealing gasket 10-2, and then the negative pressure spring 10-4 is put on, stuck on the top of the fixing seat 10-, and finally placed between the isolation valve housing 5 and the lower cover 9 together with the high pressure spring 10-6.

[0035] like Figure 3 As shown, the over-pressure opening principle is that when the pressure in the fuel tank increases, the pressure in the fuel tank will fill the cavity below the diaphragm 3, and pass through the umbrella valve A among the four umbrella valves 4, and enter the cavity with the spring 2 above the diaphragm 3. Because the pressure above and below the diaphragm 3 is the same, the diaphragm 3 will seal the pipe mouth of the carbon canister more and more tightly as the pressure increases.

[0036] like Figure 4 As shown, when the solenoid valve receives the opening command, the solenoid valve opens, and the pressure in the chamber where the spring is located quickly flows to the uppermost chamber, and then quickly discharges to the carbon canister through the umbrella valve D. Since the pressure on the upper part of the diaphragm is quickly released, the pressure on the lower part of the diaphragm pushes the diaphragm up, so that the pressure in the fuel tank begins to flow into the carbon canister rapidly in the direction of the arrow until the fuel tank pressure is released to the point where it cannot overcome the diaphragm opening.

[0037] like Figure 5 As shown in the figure, the negative pressure opening principle is that when the negative pressure in the fuel tank increases, the negative pressure in the fuel tank will fill the bottom of the diaphragm and enter the uppermost cavity through the umbrella valve B. At this time, if the negative pressure leaks into the cavity where the spring is located, the umbrella valve outlet C will replenish the atmospheric pressure from the carbon canister in time to prevent the diaphragm from being sucked up by the negative pressure. The higher the negative pressure in the fuel tank, the tighter the diaphragm will be sucked, so as to achieve a seal between the fuel tank and the carbon canister.

[0038] like Figure 6 As shown, when the solenoid valve receives the opening command, the solenoid valve opens, and the pressure in the cavity where the spring is located quickly flows to the uppermost cavity, and then is quickly sucked back to the oil tank through the umbrella valve B. The cavity where the diaphragm is located quickly creates negative pressure, which sucks up the diaphragm, thereby reaching the external atmospheric pressure and starting to quickly replenish the oil tank in the direction of the arrow until the negative pressure in the oil tank cannot overcome the deformation resistance of the diaphragm and the diaphragm rebounds.

[0039] like Figure 7 As shown, the working principle of the overpressure / negative pressure safety valve module is that under normal circumstances, when the safety valve is closed, the sealing gasket is pressed against the shell due to the spring force.

[0040] like Figure 8 As shown, when the internal pressure of the oil tank is greater than the opening pressure of the high-pressure safety valve, the high-pressure safety valve opens.

[0041] like Fig. 9 As shown, when the negative pressure inside the oil tank is greater than the opening pressure of the negative pressure safety valve, the negative pressure safety valve opens.

[0042] Due to battery drive, the fuel tank of a hybrid vehicle may not be in operation for a long time. At this time, the fuel tank isolation valve is closed, which is needed to prevent the fuel from evaporating from the fuel tank to the atmosphere.

[0043] When the fuel pressure inside the fuel tank increases or decreases with the temperature, the tank isolation valve must be opened in time when the tank pressure sensor identifies the limit pressure in the high-pressure tank, so as to release the overpressure / negative pressure inside the high-pressure tank. When the pressure sensor is not working, the tank isolation valve has the function of actively releasing the overpressure / negative pressure.

[0044] Before each refueling, the high-pressure fuel tank must release the internal pressure of the tank in time by opening the fuel isolation valve after receiving the refueling signal.

Claims

1. A fuel tank isolation valve, comprising an isolation valve housing, a solenoid valve, an upper cover, a lower cover, a spring, and a diaphragm, characterized in that: Connecting pipes are respectively provided at the left and right ends of the isolation valve housing (5); the upper end of the isolation valve housing (5) is connected to a plurality of umbrella valves (4); a diaphragm (3) is provided above the isolation valve housing (5); the upper part of the diaphragm (3) is connected to an upper cover (1) via a spring (2); the lower part of the isolation valve housing (5) is connected to a lower cover (9) via an overpressure / negative pressure safety valve module (10); one end of a solenoid valve (7) is embedded in one side of the isolation valve housing (5); the other end of the solenoid valve (7) is connected to a solenoid valve cover (8); The over-pressure opening principle of the fuel tank isolation valve is as follows: when the pressure in the fuel tank increases, the pressure in the fuel tank will fill the cavity below the diaphragm (3), and enter the cavity with the spring (2) above the diaphragm (3) through the umbrella valve A among the four umbrella valves (4). Since the pressure above and below the diaphragm (3) is the same, the diaphragm (3) will seal the pipe opening of the carbon canister more and more tightly as the pressure increases; When the solenoid valve (7) receives the opening command, the solenoid valve (7) opens, and the pressure in the cavity where the spring (2) is located quickly flows to the uppermost cavity, and then quickly discharges to the carbon canister through the umbrella valve D. As the pressure on the upper part of the diaphragm (3) is quickly released, the pressure on the lower part of the diaphragm (3) pushes the diaphragm (3) up, so that the pressure in the fuel tank starts to flow into the carbon canister quickly along the direction of the arrow until the pressure in the fuel tank is released to a level that cannot overcome the opening of the diaphragm (3); The negative pressure opening principle of the fuel tank isolation valve is as follows: when the negative pressure in the fuel tank increases, the negative pressure in the fuel tank will fill the area below the diaphragm (3) and enter the uppermost cavity through the umbrella valve B. At this time, if negative pressure leaks into the cavity where the spring (2) is located, the umbrella valve outlet C will promptly replenish atmospheric pressure from the carbon canister to prevent the diaphragm (3) from being sucked up by the negative pressure. The higher the negative pressure in the fuel tank, the tighter the diaphragm (3) will be sucked, thereby achieving a seal between the fuel tank and the carbon canister. When the solenoid valve (7) receives an opening command, the solenoid valve (7) opens, and the pressure in the cavity where the spring (2) is located quickly flows to the uppermost cavity, and then is quickly sucked back to the oil tank through the umbrella valve B. The cavity where the diaphragm (3) is located quickly develops negative pressure, sucking up the diaphragm (3), thereby reaching the external atmospheric pressure and starting to quickly replenish the oil tank in the direction of the arrow until the negative pressure in the oil tank cannot overcome the deformation resistance of the diaphragm, and the diaphragm (3) rebounds.

2. A fuel tank isolation valve according to claim 1, characterized in that: The overpressure / negative pressure safety valve module (10) comprises a sealing pin, a sealing gasket, a base, a negative pressure spring, a fixing seat, and a high pressure spring. The top of the base (10-3) is connected to the sealing pin (10-1) via a sealing gasket (10-2); the bottom of the base (10-3) is connected to the fixing seat (10-5) via a negative pressure spring (10-4); and a high pressure spring (10-6) is sleeved on the outer sides of the negative pressure spring (10-4) and the fixing seat (10-5).

3. The fuel tank isolation valve according to claim 2, characterized in that: The lower part of the sealing pin (10-1) is embedded in the base (10-3).

4. The fuel tank isolation valve according to claim 2, characterized in that: The top of the negative pressure spring (10-4) abuts against the bottom of the base (10-3), and the bottom of the negative pressure spring (10-4) abuts against the top of the fixing seat (10-5).

5. The fuel tank isolation valve according to claim 2, characterized in that: The top of the high-pressure spring (10-6) abuts against the bottom of the base (10-3), and the bottom of the high-pressure spring (10-6) abuts against the top groove of the lower cover (9).

6. The fuel tank isolation valve according to claim 1, characterized in that: An O-ring (6) is provided between one end of the solenoid valve (7) and the isolation valve housing (5).

7. The fuel tank isolation valve according to claim 1, characterized in that: The top of the spring (2) abuts against the bottom of the upper cover (1), and the bottom of the spring (2) abuts against the inner groove of the upper end of the diaphragm (3).

8. The fuel tank isolation valve according to claim 1, characterized in that: One end of the isolation valve housing (5) is connected to the oil tank, and the other end of the isolation valve housing (5) is connected to the carbon canister.

9. The fuel tank isolation valve according to claim 1, characterized in that: At least four umbrella-shaped valves (4) are provided.

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