Pressure retaining valve

Abstract

The utility model relates to a pressure retaining valve which comprises a valve body, a spring and a piston, one side of the valve body is provided with a first valve nozzle connected with an automobile carbon tank, and the other side of the valve body is provided with a second valve nozzle connected with an oil tank. A spring and a piston are sequentially arranged on the inner end face of the first valve nozzle, the piston is annular, one end of the spring abuts against the bottom of the valve nozzle, the other end of the spring abuts against the bottom of the piston, the top of the piston is attached to the sealing face of the valve body, and the valve is in a normally-closed state. The interior of the oil tank is in a positive pressure state, and elastic force of the spring can control opening and exhausting of the pressure retaining valve. According to the utility model, the function of supplying air to the oil tank can be realized when the relative pressure difference of the oil tank is in a negative pressure state.

Description

Technical Field

[0001] The utility model relates to the field of valves, in particular to a pressure-maintaining valve. Background Art

[0002] Valves are pipeline accessories used to open and close pipelines, control flow direction, and adjust and control the parameters (temperature, pressure and flow) of the transported medium.

[0003] The valve is normally closed because the pressure of the spring makes the piston fit the sealing surface of the valve body. When the car is in normal use, the inside of the fuel tank is in a positive pressure state, and the elastic force of the spring can control the opening and exhaust capacity of the pressure-maintaining valve. Therefore, the valve can realize the low-pressure sealing function of the fuel tank and the high-pressure exhaust function. Ensure the normal refueling function and safe use of the car tank.

[0004] An umbrella-shaped sealing sheet is provided between the piston and the valve body in the existing pressure-maintaining valve. The umbrella-shaped sealing sheet has relatively high strength, and long-term adhesion may cause adhesion of the rubber parts, poor opening, and unstable ventilation performance. The traditional pressure-maintaining valve oil tank is filled with air when the relative pressure difference is in a negative pressure state, which easily causes the risk of the oil tank being sucked flat. Summary of the invention

[0005] The utility model aims to overcome the defects of the prior art and provide a pressure-maintaining valve to solve the problems of oil tank deflation and unstable ventilation performance.

[0006] In order to solve the above technical problems, the utility model is achieved as follows:

[0007] A pressure-maintaining valve, characterized in that it comprises a valve body, a spring and a piston, wherein a first valve nozzle connected to a carbon canister of an automobile is provided on one side of the valve body, and a second valve nozzle connected to a fuel tank is provided on the other side of the valve body; a spring and a piston are provided in sequence on the inner end surface of the first valve nozzle, the piston is annular, one end of the spring abuts against the bottom of the valve nozzle, the other end of the spring abuts against the bottom of the piston, the top of the piston fits against the sealing surface of the valve body, and the valve is in a normally closed state; the interior of the fuel tank is in a positive pressure state, and the elastic force of the spring can control the opening and exhaust of the pressure-maintaining valve.

[0008] The pressure-maintaining valve is characterized in that grooves are respectively provided at both ends of the sealing area where the valve body contacts the piston, so that air can be replenished into the oil tank when the relative pressure difference of the oil tank is in a negative pressure state.

[0009] The pressure-maintaining valve is characterized in that a rubber sealing sheet is provided on the sealing surface where the piston contacts the valve body.

[0010] The beneficial effects of the utility model are as follows: It can be seen from the above technical solution that the application provides a pressure-maintaining valve, which realizes the function of replenishing air to the oil tank when the relative pressure difference of the oil tank is a negative pressure state by respectively providing grooves at both ends of the sealing area where the valve body contacts the piston. The flat sealing sheet can ensure stable ventilation performance and the sealing effect of the pressure-maintaining valve at low pressure. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] The present invention is further described in detail below in conjunction with the accompanying drawings and implementation examples:

[0012] Figure 1 This is a schematic diagram of the structure of this application.

[0013] Figure 2 An enlarged schematic diagram of the two grooves in the sealing area.

[0014] Figure 3 for Figure 2 Side view. DETAILED DESCRIPTION

[0015] The technical solutions of the embodiments of the present application will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field without creative work based on the embodiments in the embodiments of the present application are within the scope of protection requested by the present application.

[0016] like Figure 1-3 As shown: a pressure-maintaining valve, which includes a valve body 1, a spring 2 and a piston 3. A first valve nozzle 4 connected to a carbon canister of an automobile is provided on one side of the valve body, and a second valve nozzle 5 connected to a fuel tank is provided on the other side of the valve body; a spring and a piston are provided in sequence on the inner end surface of the first valve nozzle, the piston is annular, one end of the spring abuts against the bottom of the valve nozzle, the other end of the spring abuts against the bottom of the piston, the top of the piston fits against the sealing surface of the valve body, and the valve is in a normally closed state; the interior of the fuel tank is in a positive pressure state, and the elastic force of the spring can control the opening and exhaust of the pressure-maintaining valve.

[0017] Furthermore, grooves 6 are respectively provided at both ends of the sealing area where the valve body contacts the piston, so that the oil tank can be replenished with air when the relative pressure difference of the oil tank is in a negative pressure state. The two grooves on the sealing area can satisfy the function of replenishing air to the oil tank when the relative pressure difference of the oil tank is in a negative pressure state, thereby avoiding the risk of the oil tank being deflated.

[0018] Furthermore, a rubber sealing sheet 7 is provided on the sealing surface where the piston contacts the valve body. The sealing sheet is a flat sealing sheet, which can ensure stable ventilation performance and a good sealing effect of the pressure-maintaining valve at low pressure.

[0019] When the car is in normal use, the inside of the fuel tank is in a positive pressure state, and the elastic force of the spring can control the opening and exhaust capacity of the pressure-maintaining valve. Therefore, the valve can realize the low-pressure sealing function of the fuel tank and the high-pressure exhaust function, ensuring the normal refueling function and safe use of the car's fuel tank.

[0020] The above are only embodiments provided for the present application and are not intended to limit the present application. Although the present application is described in detail with reference to the embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or make equivalent substitutions for some of the technical features therein. However, any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present application should be included in the protection scope of the present application.

Claims

1. A pressure-maintaining valve, characterized in that: It includes a valve body, a spring and a piston. A first valve nozzle connected to a carbon canister of an automobile is provided on one side of the valve body, and a second valve nozzle connected to a fuel tank is provided on the other side of the valve body. A spring and a piston are provided in sequence on the inner end surface of the first valve nozzle. The piston is annular. One end of the spring abuts against the bottom of the valve nozzle, and the other end of the spring abuts against the bottom of the piston. The top of the piston fits against the sealing surface of the valve body, and the valve is in a normally closed state. The interior of the fuel tank is in a positive pressure state, and the elastic force of the spring can control the opening and exhaust of the pressure-maintaining valve.

2. A pressure-maintaining valve according to claim 1, characterized in that: Grooves are respectively provided at both ends of the sealing area where the valve body contacts the piston, so that air can be replenished into the oil tank when the relative pressure difference of the oil tank is in a negative pressure state.

3. A pressure-maintaining valve according to claim 1, characterized in that: A rubber sealing sheet is arranged on the sealing surface where the piston contacts the valve body.

Images