Overturn anti-overflow fire-retardant breather valve

Abstract

The invention discloses a fire-retardant breather valve capable of preventing overflow during overturning, and belongs to the technical field of breather valves. A pressure regulating assembly comprises a positive pressure valve core, a negative pressure valve core, a pressure regulating component and a pressure regulating component, and the positive pressure valve core comprises a vent hole penetrating through the bottom of the positive pressure valve core; the negative-pressure valve element is inserted into the positive-pressure valve element, and when the positive-pressure valve element and the negative-pressure valve element move relatively in the axial direction, the vent hole is communicated; the joint of the vent hole and the bottom of the positive pressure valve element is sunken inwards to form an annular groove. The end, close to the vent hole, of the negative pressure valve element is sleeved with a sealing ring. And in the resetting process after the positive pressure valve element and the negative pressure valve element relatively move in the axial direction, the sealing ring is compressed by the positive pressure valve element or the negative pressure valve element to be tightened. The joint of the vent hole and the bottom of the positive-pressure valve element is concaved inwards to form the annular groove, the end, close to the vent hole, of the negative-pressure valve element is sleeved with the sealing ring, the sealing ring is automatically tightened through relative movement of the positive-pressure valve element and the negative-pressure valve element, and the sealing performance is improved.

Description

Technical Field

[0001] The invention relates to the technical field of breathing valves, in particular to an overturning anti-overflow fire-blocking breathing valve. Background Art

[0002] The tank truck breathing valve is a key component specially designed and installed on the top of the tank truck or storage tank to finely control the pressure balance in the tank. Its core function is to adjust the pressure in time by responding to the fluctuation of ambient temperature and the increase or decrease of liquid in the tank, avoiding damage to the tank body caused by abnormal pressure increase or decrease, and ensuring the safety and reliability of the transportation process.

[0003] However, if Figures 1 to 3 As shown in the figure, conventional tank truck breathing valves mostly use flat washers as sealing elements. This design has certain defects. In actual operation, the pre-tightening of the valve disc and the valve seat often causes the flat washers to be unable to be tightly pressed together, resulting in unsatisfactory sealing effects. Therefore, it has become urgent to transform the existing flat washers or explore new sealing technologies.

[0004] When exploring the use of seals as an alternative, we must re-examine the installation strategy of the seals and focus on solving the problem of insufficient sealing similar to flat gaskets. This not only involves the layout of the seals, positive pressure valve cores, and negative pressure valve cores, but more importantly, it is important to ensure that the sealing elements can be accurately compressed during operation to provide stable and reliable sealing performance. Summary of the invention

[0005] The purpose of this section is to summarize some aspects of embodiments of the present invention and briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this section and the specification abstract and the invention title of this application to avoid blurring the purpose of this section, the specification abstract and the invention title, and such simplifications or omissions cannot be used to limit the scope of the present invention.

[0006] In view of the above problems and / or the problems existing in the prior art, the present invention is proposed.

[0007] Therefore, the first object of the present invention is to provide a pressure regulating assembly, which can replace the flat gasket with a sealing ring and rearrange the position of the sealing ring to improve the sealing performance.

[0008] To solve the above technical problems, the present invention provides the following technical solutions: a pressure regulating assembly, comprising a positive pressure valve core, comprising an air vent running through the bottom of the positive pressure valve core; a negative pressure valve core, which is inserted into the positive pressure valve core, and when the positive pressure valve core and the negative pressure valve core undergo relative axial movement, the air vent is connected; the connection between the air vent and the bottom of the positive pressure valve core is recessed inward to form an annular groove; a sealing ring is provided at one end of the negative pressure valve core close to the air vent; during the resetting process after the positive pressure valve core and the negative pressure valve core undergo relative axial movement, the sealing ring is tightened by the pressure of the positive pressure valve core or the negative pressure valve core.

[0009] As a preferred solution of the pressure regulating assembly of the present invention, the negative pressure valve core includes a pressure plate arranged at the bottom of the negative pressure valve core, the pressure plate is coaxially arranged with the vent, and the inner diameter of the vent is smaller than the outer diameter of the pressure plate.

[0010] As a preferred solution of the pressure regulating assembly of the present invention, the cross-sectional shape of the annular groove is a right triangle, the length of the horizontal side of the right triangle is defined as d1, the inner diameter of the vent hole is r1, and the outer diameter of the pressure plate is r2, then r1<r2≤r1+d1.

[0011] As a preferred solution of the pressure regulating assembly of the present invention, the annular groove is ground to a mirror-like grade of 0.04 μm.

[0012] As a preferred solution of the pressure regulating assembly of the present invention, at least one flow channel is provided on the outer circumferential surface of the positive pressure valve core, and the flow channel is connected to the vent hole.

[0013] As a preferred solution of the pressure regulating assembly of the present invention, wherein: a mounting hole is provided at the top of the positive pressure valve core, the negative pressure valve core is slidably connected to the mounting hole, and the end of the negative pressure valve core away from the vent hole extends out from the mounting hole, and a negative pressure spring is provided at the end of the negative pressure valve core away from the vent hole, and the negative pressure spring is connected to the top of the positive pressure valve core.

[0014] A second object of the present invention is to provide a breathing valve whose internal structure is rearranged so as to match the sealing ring.

[0015] To solve the above technical problems, the present invention provides the following technical solutions: a breathing valve, comprising: the above-mentioned pressure regulating assembly; and a shell, a bottom of which is provided with a first through hole and a side of which is provided with a second through hole, the first through hole being capable of being connected to the air vent, and the second through hole being connected to the circulation channel; an upper cover body, which is detachably connected to the shell, and a accommodating space is formed between the upper cover body and the shell, and an end of the negative pressure valve core away from the air vent is located in the accommodating space; a positive pressure spring, which is located in the accommodating space, and the two ends of the positive pressure spring respectively conflict with the inner bottom wall of the upper cover body and the top of the positive pressure valve core.

[0016] As a preferred solution of the breathing valve of the present invention, it further comprises a protective cover and a fire-blocking cover, wherein the protective cover is sleeved on the shell, and the fire-blocking cover is arranged between the protective cover and the shell.

[0017] As a preferred solution of the breathing valve of the present invention, the anti-dumping component includes a mounting shell arranged at the bottom of the shell, a sealing hemisphere arranged in the mounting shell, and a gasket arranged in the first through hole; when the breathing valve dumps, the sealing hemisphere moves in a direction close to the gasket, and the spherical surface of the sealing hemisphere can seal the gasket.

[0018] As a preferred solution of the breathing valve of the present invention, wherein: a spherical hole is opened on the bottom plane of the sealing hemisphere, a spherical rotating block is arranged in the spherical hole, a return spring is arranged in the mounting shell, and the return spring is connected to the spherical rotating block; when the breathing valve is vertical, the return spring is completely compressed by the gravity of the sealing hemisphere and the spherical rotating block; when the breathing valve is tilted, the gravity component of the sealing hemisphere and the spherical rotating block along the axial direction of the return spring is smaller than the elastic force of the return spring.

[0019] The beneficial effects of the present invention are as follows: an annular groove is formed by inward depression at the connection between the vent hole and the bottom of the positive pressure valve core, a sealing ring is sleeved on the end of the negative pressure valve core close to the vent hole, and the sealing ring is automatically tightened by the relative movement of the positive pressure valve core and the negative pressure valve core, thereby improving the sealing performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative labor.

[0021] Figure 1 It is a structural diagram of a breathing valve in the prior art.

[0022] Figure 2It is a cross-sectional view of a breathing valve in the prior art.

[0023] Figure 3 for Figure 2 Magnified view of area B.

[0024] Figure 4 A cross-sectional view of the breathing valve.

[0025] Figure 5 This is the structural diagram of the positive pressure valve core of the breathing valve.

[0026] Figure 6 This is a positive pressure leakage test diagram of a breathing valve in the prior art.

[0027] Figure 7 This is a negative pressure leakage test diagram of the breathing valve in the prior art.

[0028] Figure 8 This is the positive pressure leakage test diagram of the breathing valve.

[0029] Fig. 9 This is the negative pressure leakage test diagram of the breathing valve.

[0030] 100, positive pressure valve core; 101, vent hole; 101a, annular groove; 102, circulation channel; 103, mounting hole; 200, negative pressure valve core; 201, sealing ring; 202, pressure plate; 300, negative pressure spring; 400, shell; 401, first through hole; 402, second through hole; 500, upper cover; 600, positive pressure spring; 700, anti-dumping assembly; 701, mounting shell; 702, blocking hemisphere; 702a, spherical hole; 703, gasket; 704, spherical rotating block; 705, reset spring; 800, protective cover; 900, fireproof cover; A, accommodating space. DETAILED DESCRIPTION

[0031] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the accompanying drawings.

[0032] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0033] Secondly, the present invention is described in detail with reference to schematic diagrams. When describing the embodiments of the present invention in detail, for the sake of convenience, the cross-sectional diagrams showing the device structure will not be partially enlarged according to the general scale, and the schematic diagrams are only examples, which should not limit the scope of protection of the present invention. In addition, in actual production, the three-dimensional dimensions of length, width and depth should be included.

[0034] Furthermore, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The term "in one embodiment" that appears in different places in this specification does not necessarily refer to the same embodiment, nor does it refer to a separate or selective embodiment that is mutually exclusive with other embodiments.

[0035] Example 1, reference Figure 4~Figure 9 , which is the first embodiment of the present invention, provides a pressure regulating assembly, including a positive pressure valve core 100 and a negative pressure valve core 200, and the sealing ring 201 is tightened by the relative movement of the positive pressure valve core 100 and the negative pressure valve core 200.

[0036] Specifically, the positive pressure valve core 100 includes a vent hole 101 that runs through the bottom of the positive pressure valve core 100, and the vent hole 101 is used for ventilation; the negative pressure valve core 200 is inserted into the positive pressure valve core 100, and when the positive pressure valve core 100 and the negative pressure valve core 200 move relative to each other axially, the vent hole 101 is connected; the positive pressure valve core 100 is opened when the pressure in the tank increases, and releases the gas in the tank to the external environment to prevent the tank body from being ruptured due to excessive pressure in the tank; the negative pressure valve core 200 is opened when the pressure in the tank decreases, allowing external gas to enter the tank to prevent the formation of negative pressure in the tank and collapse of the tank body. When the pressure in the tank exceeds the set pressure, the positive pressure valve core 100 will move upward, the vent hole 101 will be connected and form a gas discharge channel, thereby reducing the pressure in the tank; when the pressure in the tank is lower than the atmospheric pressure, the negative pressure valve core 200 will move downward, and the vent hole 101 will be connected to form a gas entry channel, thereby increasing the pressure in the tank.

[0037] It is worth noting that the positive pressure leakage refers to the situation where the positive pressure valve core 100 is completely closed, due to the incomplete seal between the positive pressure valve core 100 and the negative pressure valve core 200, a small amount of gas will still leak from the tank to the outside, which usually occurs when the pressure in the tank is higher than the atmospheric pressure. The negative pressure leakage refers to the situation where the negative pressure valve core 200 is completely closed, due to the incomplete seal, a small amount of external gas will still leak into the tank, which usually occurs when the pressure in the tank is lower than the atmospheric pressure, that is, the system is in a negative pressure state. The testing and control of leakage are crucial to ensure the safe operation of the storage tank, because they are directly related to the sealing performance and operating efficiency of the storage tank.

[0038] Preferably, the bottom connection between the vent hole 101 and the positive pressure valve core 100 is inwardly recessed to form an annular groove 101a; a sealing ring 201 is sleeved on one end of the negative pressure valve core 200 near the vent hole 101; during the reset process after the positive pressure valve core 100 and the negative pressure valve core 200 have relative axial movement, the sealing ring 201 is compressed by the positive pressure valve core 100 or the negative pressure valve core 200 and tightened. Placing the sealing ring 201 here can ensure that the external gas cannot leak into the tank through this place when the negative pressure is applied; the annular groove 101a provides a placement space for the sealing ring 201 to ensure that the sealing ring 201 will not shift or twist during the movement of the positive pressure valve core 100 and the negative pressure valve core 200, and at the same time ensure that the sealing ring 201 is evenly stressed. The use of the sealing ring 201 and the annular groove 101a together forms a double seal, which improves the reliability of the seal. By fixing the sealing ring 201 through the annular groove 101 a , possible paths for gas leakage are reduced, thereby reducing positive pressure leakage and negative pressure leakage.

[0039] Preferably, the negative pressure valve core 200 includes a pressure plate 202 arranged at the bottom of the negative pressure valve core 200 , the pressure plate 202 is coaxially arranged with the vent hole 101 , and the inner diameter of the vent hole 101 is smaller than the outer diameter of the pressure plate 202 .

[0040] Preferably, the cross-sectional shape of the annular groove 101a is a right triangle, and the length of the horizontal side of the right triangle is defined as d1, the inner diameter of the vent hole is r1, and the outer diameter of the pressure plate is r2, then r1<r2<r1+d1. This design brings a variety of beneficial effects, such as a double sealing effect: a sealing ring 201 is provided at the position where the bottom of the negative pressure valve core 200 contacts the positive pressure valve core 100, which can provide a seal between two important moving parts, ensuring that external gas cannot enter when the negative pressure valve core 200 is actuated, and at the same time ensuring that the internal gas cannot leak out when the positive pressure valve core 100 is actuated. Effectively prevent pressure fluctuations: This position is the dynamic contact point between the positive pressure valve core 100 and the negative pressure valve core 200. When switching, this position will be affected by pressure. The sealing ring 201 at this position can effectively prevent gas leakage during pressure fluctuations. In addition, the valve core movement is utilized: when the negative pressure valve core 200 and the positive pressure valve core 100 are opened or closed, they will make relative movement; the sealing ring 201 can utilize this movement to improve its sealing effect, because the movement of the negative pressure valve core 200 and the positive pressure valve core 100 will help compact the sealing ring 201 and enhance the sealing.

[0041] Preferably, the annular groove 101a is ground to a mirror grade of 0.04 μm; precision grinding can ensure that the sealing surface is flat and smooth, thereby improving the sealing effect of the sealing ring 201. Precision grinding can reduce friction and wear between the sealing surfaces and extend the service life of the sealing ring 201. Precision grinding ensures good contact between the sealing surfaces and reduces the risk of gas leakage through potential uneven surfaces.

[0042] Preferably, at least one circulation channel 102 is provided on the outer circumferential surface of the positive pressure valve core 100 . In this embodiment, there are eight circulation channels 102 . The eight circulation channels 102 are arranged around the outer circumferential surface of the positive pressure valve core 100 , and the circulation channels 102 are connected to the vent holes 101 .

[0043] Preferably, a mounting hole 103 is provided at the top of the positive pressure valve core 100, the negative pressure valve core 200 is slidably connected to the mounting hole 103, and one end of the negative pressure valve core 200 away from the vent hole 101 extends out of the mounting hole 103, and one end of the negative pressure valve core 200 away from the vent hole 101 is provided with a negative pressure spring 300, and the negative pressure spring 300 is connected to the top of the positive pressure valve core 100. The negative pressure spring 300 is used to provide an axial reset force to the negative pressure valve core 200.

[0044] Embodiment 2 is the second embodiment of the present invention, which is basically the same as Embodiment 1, except that r2=r1+d1 in this embodiment. This arrangement can also ensure that the movement of the negative pressure valve core 200 and the positive pressure valve core 100 will help compact the sealing ring 201 and enhance the sealing.

[0045] Example 3, see Figure 4~Figure 9 , which is the third embodiment of the present invention, and this embodiment is based on embodiment 1 or embodiment 2. This embodiment provides a breathing valve, which includes a housing 400 , an upper cover 500 and a positive pressure spring 600 .

[0046] Preferably, a first through hole 401 is provided at the bottom of the shell 400 , and a second through hole 402 is provided at the side of the shell 400 . The first through hole 401 can be connected to the vent hole 101 , and the second through hole 402 is connected to the circulation channel 102 .

[0047] Preferably, the upper cover body 500 is detachably connected to the shell body 400, and the upper cover body 500 covers the top of the shell body 400. An accommodating space A is formed between the upper cover body 500 and the shell body 400, and the end of the negative pressure valve core 200 away from the vent hole 101 is located in the accommodating space A.

[0048] Preferably, the positive pressure spring 600 is located in the accommodating space A, and the two ends of the positive pressure spring 600 are respectively in contact with the inner bottom wall of the upper cover 500 and the top of the positive pressure valve core 100. The positive pressure spring 600 is used to provide axial restoring force to the positive pressure valve core 100.

[0049] Preferably, it further comprises a protection cover 800 and a fire-blocking cover 900, wherein the protection cover is sleeved on the housing 400, and the fire-blocking cover is arranged between the protection cover and the housing 400. The fire-blocking cover 900 can block fire.

[0050] Preferably, the anti-dumping assembly 700 includes a mounting shell 701 arranged at the bottom of the shell 400, a sealing hemisphere 702 arranged in the mounting shell 701, and a gasket 703 arranged in the first through hole 401; the interior of the mounting shell 701 is hollow, and a plurality of holes are provided on the outer circumferential surface. When the breathing valve dumps, the sealing hemisphere 702 moves toward the direction close to the gasket 703 under the action of gravity, and the spherical surface of the sealing hemisphere 702 can seal the gasket 703.

[0051] Preferably, a spherical hole 702a is opened on the bottom plane of the sealing hemisphere 702, a spherical rotating block 704 is arranged in the spherical hole 702a, a return spring 705 is arranged in the mounting shell 701, and the return spring 705 is connected to the spherical rotating block 704; when the breathing valve is vertical, the return spring 705 is completely compressed by the gravity of the sealing hemisphere 702 and the spherical rotating block 704; when the breathing valve is tilted, the gravity component of the sealing hemisphere 702 and the spherical rotating block 704 along the axial direction of the return spring 705 is smaller than the elastic force of the return spring 705.

[0052] Compared with the conventional breathing valve which is only provided with the blocking hemisphere 702, the conventional breathing valve is not very sensitive to the overturning angle. Only when the breathing valve overturns beyond the horizontal plane and continues to overturn, the blocking hemisphere 702 can completely block the gasket 703. However, by providing the reset spring 705 and the spherical rotating block 704, the blocking hemisphere 702 and the spherical rotating block 704 can move in advance towards the direction close to the gasket 703 under the action of the reset spring 705 before the breathing valve overturns beyond the horizontal plane, thereby improving the sensitivity of the breathing valve to prevent overturning.

[0053] See also Figure 6 and Figure 7 In addition, it is worth noting that the breathing valve test of the prior art is as follows: take-off pressure test: positive pressure: +119mbar, negative pressure: -26mbar; leakage test: positive pressure (+108.3mbar): leakage: 0.3376 m3 / h, leakage rate: F; negative pressure (-19.7mbar): leakage: 0.1217m3 / h, leakage rate: F; the leakage rate refers to the following standards: QC / T1064-2017, BS EN 12266-1-2017.

[0054] See also Figure 8 and Fig. 9 , and the test results of the present invention are: after actual measurement, the positive pressure leakage at 0.9 times the opening pressure is 0.0004158m 3 / h, the negative pressure leakage is 0.0002346m 3 / h, the positive pressure leakage of the existing breathing valve is 0.3376m 3 / h, the negative pressure leakage is 0.1217m3 / h; according to BS EN 12266-1-2017 standard test, the leakage rate meets the C-level standard, which is far higher than existing products.

[0055] Based on the above, the beneficial effects of the present invention are: 1. By utilizing the movement of the valve core, when the negative pressure valve core 200 and the positive pressure valve core 100 are opened or closed, they will move relative to each other; the sealing ring 201 can utilize this movement to improve its sealing effect, because the movement of the negative pressure valve core 200 and the positive pressure valve core 100 will help compact the sealing ring 201 and enhance the sealing.

[0056] 2. By setting the return spring 705 and the spherical rotating block 704, before the breathing valve overturns beyond the horizontal plane, the blocking hemisphere 702 and the spherical rotating block 704 can move in advance towards the direction close to the gasket 703 under the action of the return spring 705, thereby improving the anti-overturning sensitivity of the breathing valve.

[0057] 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 preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A pressure regulating assembly, characterized in that: include: A positive pressure valve core (100), comprising a vent hole (101) penetrating the bottom of the positive pressure valve core (100); A negative pressure valve core (200) is inserted into the positive pressure valve core (100), and when the positive pressure valve core (100) and the negative pressure valve core (200) move relative to each other in the axial direction, the vent hole (101) is connected; The connection between the vent hole (101) and the bottom of the positive pressure valve core (100) is recessed inwards to form an annular groove (101a); a sealing ring (201) is sleeved on one end of the negative pressure valve core (200) close to the vent hole (101); During the resetting process after the positive-pressure valve core (100) and the negative-pressure valve core (200) have undergone relative axial movement, the sealing ring (201) is compressed by the positive-pressure valve core (100) or the negative-pressure valve core (200) and tightened.

2. The pressure regulating assembly according to claim 1, characterized in that The negative pressure valve core (200) comprises a pressure plate (202) arranged at the bottom of the negative pressure valve core (200); the pressure plate (202) is coaxially arranged with the vent hole (101); the inner diameter of the vent hole (101) is smaller than the outer diameter of the pressure plate (202).

3. The pressure regulating assembly according to claim 2, characterized in that The cross-sectional shape of the annular groove (101a) is a right triangle, the length of the horizontal side of the right triangle is defined as d1, the inner diameter of the vent hole (101) is r1, and the outer diameter of the pressure plate (202) is r2, then r1<r2≤r1+d1.

4. The pressure regulating assembly according to claim 1 or 3, characterized in that: The annular groove (101a) is ground to a mirror-like level of 0.04 μm.

5. The pressure regulating assembly according to claim 1, characterized in that: At least one circulation channel (102) is provided on the outer circumferential surface of the positive pressure valve core (100), and the circulation channel (102) is connected to the vent hole (101).

6. The pressure regulating assembly according to claim 5, characterized in that A mounting hole (103) is provided at the top of the positive pressure valve core (100), the negative pressure valve core (200) is slidably connected to the mounting hole (103), and an end of the negative pressure valve core (200) away from the vent hole (101) extends out from the mounting hole (103), and a negative pressure spring (300) is provided at the end of the negative pressure valve core (200) away from the vent hole (101), and the negative pressure spring (300) is connected to the top of the positive pressure valve core (100).

7. A breathing valve, characterized in that: include: A pressure regulating assembly as claimed in claim 5 or 6; and A shell (400), wherein a first through hole (401) is provided at the bottom and a second through hole (402) is provided at the side, wherein the first through hole (401) is capable of being connected to the vent hole (101), and the second through hole (402) is connected to the circulation channel (102); an upper cover body (500) which is detachably connected to the shell (400), wherein an accommodation space (A) is formed between the upper cover body (500) and the shell (400), and an end of the negative pressure valve core (200) away from the vent hole (101) is located in the accommodation space (A); A positive pressure spring (600) is located in the accommodating space (A), and two ends of the positive pressure spring (600) are respectively in contact with the inner bottom wall of the upper cover body (500) and the top of the positive pressure valve core (100).

8. The breathing valve according to claim 7, characterized in that: It also comprises a protective cover (800) and a fire-blocking cover (900), wherein the protective cover (800) is sleeved on the shell (400), and the fire-blocking cover (900) is arranged between the protective cover (800) and the shell (400).

9. The breathing valve according to claim 7, characterized in that: Also includes: An anti-dumping assembly (700) comprising a mounting shell (701) arranged at the bottom of the housing (400), a blocking hemisphere (702) arranged in the mounting shell (701), and a gasket (703) arranged in the first through hole (401); When the breathing valve is tilted, the blocking hemisphere (702) moves in a direction close to the gasket (703), and the spherical surface of the blocking hemisphere (702) can block the gasket (703).

10. The breathing valve according to claim 9, characterized in that: A spherical hole (702a) is provided on the bottom plane of the blocking hemisphere (702), a spherical rotating block (704) is provided in the spherical hole (702a), a return spring (705) is provided in the mounting shell (701), and the return spring (705) is connected to the spherical rotating block (704); When the breathing valve is vertical, the return spring (705) is completely compressed due to the gravity of the blocking hemisphere (702) and the spherical rotating block (704); When the breathing valve is tilted, the gravity component force of the blocking hemisphere (702) and the spherical rotating block (704) along the axial direction of the return spring (705) is smaller than the elastic force of the return spring (705).

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