Pressure-maintaining sealing structure

Abstract

The utility model provides a pressure maintaining sealing structure which comprises a cylinder body, a first piston, a second piston, a first elastic piece and a second elastic piece. When the pressure in the gas cylinder is low, the first elastic piece pushes the first piston to the second piston, the ejector rod abuts against the vent hole, the vent hole is closed, gas in the gas cylinder cannot leak out, and the pressure in the cylinder body is kept; when the gas cylinder needs to be inflated, gas enters the position between the first piston and the second piston in the circumferential direction of the first piston, due to the fact that the gas inlet pressure is large, the first piston is pushed, the ejector rod ejects the second piston, the second piston leaves the stop protrusion, and inlet gas flows in a gas path in the circumferential direction of the second piston and enters the gas cylinder through the second piston. The pressure maintaining sealing structure is simple in structure, capable of being used in cooperation with a common air valve and low in cost.

Description

Technical Field

[0001] The utility model relates to the field of gas storage, in particular to a pressure-maintaining sealing structure. Background Art

[0002] When using a gas cylinder, it is necessary to maintain a certain pressure inside the cylinder at all times. For example, in an oxygen cylinder, it is necessary to prevent contamination inside the cylinder. The valve body used in existing gas cylinders has both the functions of opening and closing and maintaining pressure and sealing, resulting in a complex structure, difficult maintenance, and high cost. How to reduce the cost of the gas cylinder valve and simplify the structure of the valve body is a problem that needs to be solved. Utility Model Content

[0003] The utility model provides a pressure-maintaining sealing device to overcome the above problems.

[0004] A pressure-maintaining sealing structure includes: a cylinder, a first piston, a second piston, a first elastic member, and a second elastic member;

[0005] The cylinder body has a cavity, one end of the cavity is connected to the gas cylinder port, and the other end is connected to the gas cylinder valve;

[0006] The first piston and the second piston are sequentially slidably disposed in the cavity, the first elastic member is disposed between the first piston and the gas cylinder valve, and the second elastic member is disposed between the second piston and the gas cylinder;

[0007] One end of the first piston is provided with a push rod, and the second piston is provided with an axially penetrating vent hole, and the push rod abuts against the vent hole;

[0008] A radially inward stop protrusion is provided in the cavity, and the first piston and the second piston are respectively placed on both sides of the stop protrusion. Air paths are provided on the outer peripheries of the first piston and the second piston. The second elastic member can press the second piston against one side of the stop protrusion to close the air path on the outer periphery of the second piston.

[0009] Furthermore, a cone is provided at the end of the push rod, a conical hole is provided at the opening of the vent hole, and the cone cooperates with the conical hole.

[0010] Furthermore, the stop protrusion has a tapered surface facing the second piston, and a sealing ring is provided between the second piston and the tapered surface.

[0011] Furthermore, a snap ring is provided in the cavity, and two ends of the second elastic member are respectively in contact with the second elastic member and the snap ring.

[0012] Furthermore, one end of the first piston is provided with a push rod, and the other end is provided with an auxiliary rod, and the auxiliary rod is outer-circuited with the first elastic member.

[0013] The utility model discloses a pressure-maintaining sealing structure. When the pressure in a gas cylinder is low, a first elastic member pushes a first piston toward a second piston, causing a push rod to abut against a vent hole, sealing the vent hole and preventing gas in the gas cylinder from leaking out, thereby maintaining the pressure in the cylinder. When the gas cylinder needs to be inflated, gas flows along the circumference of the first piston and into the space between the first and second pistons. Due to the high intake pressure, the first piston is pushed, and the push rod pushes the second piston, causing the second piston to leave the stop protrusion. The intake gas flows along the circumferential air path of the second piston and enters the gas cylinder through the second piston. The pressure-maintaining sealing structure disclosed by the utility model has a simple structure, can be used in conjunction with a common gas valve, and is low in cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following is a brief introduction to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0015] Figure 1 This is a schematic diagram of a pressure-maintaining sealing structure disclosed in the present utility model;

[0016] Figure 2 This is a schematic diagram of a pressure-maintaining sealing structure disclosed in the present utility model in a deflated state;

[0017] Figure 3 This is a schematic diagram of the air intake state of a pressure-maintaining sealing structure disclosed in the present utility model;

[0018] Figure 4 This is a schematic axial cross-sectional view of the second piston structure disclosed in an embodiment of the present utility model;

[0019] Figure 5 This is a schematic axial cross-sectional view of the cylinder structure disclosed in the embodiment of the present utility model;

[0020] Figure 6 This is a schematic axial cross-sectional view of the first piston structure disclosed in an embodiment of the present utility model;

[0021] Figure 7 This is a radial cross-sectional view of the second piston structure disclosed in an embodiment of the present utility model;

[0022] Figure 8 This is a schematic radial cross-sectional view of the first piston structure disclosed in an embodiment of the present utility model.

[0023] 1. Cylinder body; 11. Cavity; 12. Stopper protrusion; 13. Air passage; 14. Snap ring;

[0024] 2. First piston; 21. Push rod; 22. Auxiliary rod;

[0025] 3. Second piston; 31. Vent hole;

[0026] 4. a first elastic member;

[0027] 5. Second elastic member. DETAILED DESCRIPTION

[0028] To make the purpose, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the embodiments described 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 making creative efforts shall fall within the scope of protection of the present invention.

[0029] like Figure 1-8 As shown, this embodiment discloses a pressure-maintaining sealing valve, comprising: a cylinder 1, a first piston 2, a second piston 3, a first elastic member 4 and a second elastic member 5;

[0030] The cylinder body 1 has a cavity 11, one end of the cavity 11 is connected to the gas cylinder port, and the other end is connected to the gas cylinder valve;

[0031] The first piston 2 and the second piston 3 are sequentially slidably disposed in the cavity, the first elastic member 4 is disposed between the first piston 2 and the gas cylinder valve, and the second elastic member 5 is disposed between the second piston 3 and the gas cylinder;

[0032] The first piston 2 is provided with a push rod 21 at one end, and the second piston 3 is provided with an axially penetrating vent hole 31, and the push rod 21 abuts against the vent hole 31;

[0033] A radially inward stop protrusion 12 is provided in the cavity 11, and the first piston 2 and the second piston 3 are placed on both sides of the stop protrusion 12. An air path 13 is provided on the outer periphery of the first piston 2 and the second piston 3. The second elastic member 5 can press the second piston 3 to one side of the stop protrusion 11, so that the air path 13 on the outer periphery of the second piston 3 is closed.

[0034] The utility model discloses a pressure-maintaining sealing structure. When the pressure in a gas cylinder is low, a first elastic member pushes a first piston toward a second piston, causing a push rod to abut against a vent hole, sealing the vent hole and preventing gas in the gas cylinder from leaking out, thereby maintaining the pressure in the cylinder. When the gas cylinder needs to be inflated, gas flows along the circumference of the first piston and into the space between the first and second pistons. Due to the high intake pressure, the first piston is pushed, and the push rod pushes the second piston, causing the second piston to leave the stop protrusion. The intake gas flows along the circumferential air path of the second piston and enters the gas cylinder through the second piston. The pressure-maintaining sealing structure disclosed by the utility model has a simple structure, can be used in conjunction with an ordinary gas valve that only has an on / off function, and is low in cost.

[0035] Specifically, the pressure-maintaining sealing structure disclosed in this embodiment is provided at the mouth of the gas cylinder and can be connected by threaded connection, with the other end connected to a common gas cylinder valve. The first piston and the second piston in this embodiment have a maximum outer diameter that can fit into the inner cavity of the cylinder. Figure 1 As shown, when the gas cylinder is at rest, the gas cylinder valve is closed, the second elastic member presses the second piston onto the stop protrusion 12, closing the gas path 13 circumferentially of the second piston, and the first elastic member presses the first piston toward the second piston, causing the ejector rod 21 to close the vent hole 31, and the pressure-maintaining sealing structure is in a closed state; Figure 2 As shown, when the gas cylinder is deflated, the gas cylinder valve opens, the gas pressure on the side of the first piston is lower, and the gas cylinder pressure is higher, pushing the push rod open, and the gas flows from the vent hole 31 to between the first piston and the second piston, and passes through the first piston through the gas path circumferentially of the first piston and leaves the gas cylinder valve; Figure 3 As shown, when the gas cylinder is inflated, the cylinder valve opens, and gas enters under higher pressure. The high-pressure gas pushes the first piston to move, and the push rod 21 pushes the second piston, causing the second piston to leave the stop protrusion. The circumferential gas path of the second piston is opened, and the gas passes through the second piston and enters the gas cylinder.

[0036] In this embodiment, the end of the push rod 21 is provided with a cone, and the opening of the vent hole 31 is provided with a tapered hole. The cone and the tapered hole cooperate to better seal the tapered hole. A sealing ring can be provided between the cone and the tapered hole to further enhance the sealing effect.

[0037] The stop protrusion 11 has a tapered surface facing the second piston 3, with a sealing ring disposed between the second piston 3 and the tapered surface. The end of the second piston 3 has a smaller outer diameter and abuts against the tapered surface. The tapered surface can be simultaneously provided on the end of the second piston 3, and a sealing ring is disposed between the second piston 3 and the stop protrusion 11 to improve the sealing effect.

[0038] In this embodiment, a snap ring 14 is disposed within the cavity, and the ends of the second elastic member 5 abut against the second elastic member 5 and the snap ring 14, respectively. A snap ring is disposed within a snap groove at the end of the cavity, and a second elastic member is disposed between the snap ring and the second piston. The second elastic member presses the second piston against the stop protrusion 11, preventing gas from passing between the second piston and the stop protrusion.

[0039] In this embodiment, the first piston 2 has a push rod 21 at one end and an auxiliary rod 22 at the other end, and the auxiliary rod 22 is covered with the first elastic member 4. One end of the first elastic member abuts against the first piston, and the other end abuts against the cylinder valve.

[0040] In this embodiment, the first elastic member and the second elastic member are both springs.

[0041] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A pressure-maintaining sealing structure, characterized in that: include: Cylinder (1), first piston (2), second piston (3), first elastic member (4) and second elastic member (5); The cylinder body (1) has a cavity (11), one end of the cavity (11) is connected to the gas cylinder port, and the other end is connected to the gas cylinder valve; The first piston (2) and the second piston (3) are slidably disposed in the cavity (11) in sequence, the first elastic member (4) is disposed between the first piston (2) and the gas cylinder valve, and the second elastic member (5) is disposed between the second piston (3) and the gas cylinder; One end of the first piston (2) is provided with a push rod (21), and the second piston (3) is provided with an axially penetrating vent hole (31), and the push rod (21) abuts against the opening of the vent hole (31); A radially inward stop protrusion (12) is provided in the cavity (11), the first piston (2) and the second piston (3) are respectively placed on both sides of the stop protrusion (12), and an air path (13) is provided on the periphery of each of the first piston (2) and the second piston (3). The second elastic member (5) can press the second piston (3) against one side of the stop protrusion (12), so that the air path (13) on the periphery of the second piston (3) is closed.

2. A pressure-maintaining sealing structure according to claim 1, characterized in that: A cone is provided at the end of the push rod (21), and a conical hole is provided at the opening of the vent hole (31), and the cone cooperates with the conical hole.

3. The pressure-maintaining sealing structure according to claim 1, characterized in that: The stop protrusion (12) has a conical surface facing the second piston (3), and a sealing ring is provided between the second piston (3) and the conical surface.

4. The pressure-maintaining sealing structure according to claim 1, characterized in that: A snap ring (14) is provided in the cavity, and two ends of the second elastic member (5) respectively abut against the second elastic member (5) and the snap ring (14).

5. The pressure-maintaining sealing structure according to claim 1, characterized in that: One end of the first piston (2) is provided with a push rod (21), and the other end is provided with an auxiliary rod (22), and the auxiliary rod (22) is provided with the first elastic member (4) on its outer sleeve.

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