Overpressure protection device

Abstract

The overpressure protection device comprises a valve body, a valve rod, an adjusting spring assembly and an auxiliary spring assembly, an auxiliary spring cavity, an outlet cavity and an adjusting spring cavity are sequentially formed in the valve body from left to right, the valve rod transversely penetrates through the outlet cavity, and the two ends of the valve rod extend into the auxiliary spring cavity and the adjusting spring cavity correspondingly; the outlet cavity is not communicated with the adjusting spring cavity and is communicated with the auxiliary spring cavity through the valve rod; the auxiliary spring assembly is installed in the auxiliary spring cavity, a working medium flow channel is formed in the auxiliary spring assembly, and the auxiliary spring assembly abuts against the left end of the valve rod. The adjusting spring assembly is installed in the adjusting spring cavity and abuts against the right end of the valve rod. According to the safety valve, the valve rod is balanced through rightward working medium pressure of the auxiliary spring cavity and the outlet cavity and leftward adjusting spring force of the adjusting spring, the problem that an overpressure protection device is subjected to back pressure to generate flutter during pressure relief is solved through a back pressure resisting structure, and the stability and reliability of the safety valve are improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of pressure relief of space propulsion system, in particular, to an overpressure protection device. BACKGROUND

[0002] Safety valve is widely used in space propulsion system, which opens to discharge part of medium in the system when the system pressure exceeds the specified value, so as to ensure that the system pressure does not exceed the allowable value, thereby ensuring that the system does not fail due to excessive pressure. If the safety valve vibrates when it is relieved, it may cause the system to resonate, resulting in serious system failure.

[0003] The existing Chinese patent with publication number CN205173604U discloses a safety valve capable of effectively preventing gas overpressure and overcurrent leakage, which is characterized in that: the safety valve is composed of a valve body, a clasp spring, a spring washer, a barrel-shaped closing shaft, a fixed screw, a knob, a pressure spring, a starting system, a closing system, a gas outlet, a barrel-shaped sealing glue, a cover sheet and a gas inlet, wherein the barrel-shaped closing shaft and the barrel-shaped sealing glue are arranged between the gas inlet and the gas outlet, and cooperate with the knob, the clasp spring, the spring washer, the fixed screw and the pressure spring; the closing system and the starting system are arranged at the gas inlet and cooperate with each other.

[0004] In the traditional design, the safety valve outlet is usually communicated with the adjusting spring cavity, and in this structure, the adjusting spring cavity is filled with medium when the safety valve works, which generates a leftward force to force the valve rod to move leftward. Frequent changes in medium pressure cause the valve rod to reciprocate, and the safety valve vibrates.

[0005] Therefore, it is necessary to provide an overpressure protection device, which can solve the problem of vibration caused by counter pressure when the safety valve is relieved, thereby improving the stability and reliability of the safety valve. SUMMARY

[0006] In view of the defects in the prior art, the purpose of the present application is to provide an overpressure protection device.

[0007] According to the overpressure protection device provided by the present application, the valve body, the valve rod, the adjusting spring assembly and the auxiliary spring assembly are provided, the inside of the valve body is sequentially formed with an auxiliary spring cavity, an outlet cavity and an adjusting spring cavity from left to right, the valve rod transversely penetrates the outlet cavity and extends to the auxiliary spring cavity and the adjusting spring cavity at both ends, the outlet cavity and the adjusting spring cavity are not communicated, and the outlet cavity and the auxiliary spring cavity are communicated through the valve rod. The auxiliary spring assembly is installed in the auxiliary spring cavity, and the inside of the auxiliary spring assembly is formed with a working medium flow channel, and the auxiliary spring assembly is tightly abutted with the left end of the valve rod. The adjusting spring assembly is installed in the adjusting spring cavity, and the adjusting spring assembly is tightly abutted with the right end of the valve rod. When the pressure applied by the working medium on the left end of the valve rod is not greater than the force applied by the adjusting spring assembly on the right end of the valve rod, the valve rod is in sealed connection with the auxiliary spring assembly, and the overpressure protection device is in a closed state; When the pressure applied by the working medium on the left end of the valve rod is greater than the force applied by the adjusting spring assembly on the right end of the valve rod, the valve rod can move to the right, the valve rod is in communication with the working medium flow channel, and the overpressure protection device is in an open state.

[0008] Preferably, the middle part of the valve rod is provided with a first through hole in communication with the outlet cavity, and the left side of the valve rod is internally provided with a second through hole in communication with the auxiliary spring cavity and the first through hole, and the outer wall of the side of the valve rod close to the auxiliary spring cavity is in sealed connection with the valve body through a second O-shaped ring.

[0009] Preferably, the adjusting spring assembly is fastened and installed on the right side of the valve body through an adjusting nut, the adjusting spring assembly comprises an adjusting spring seat and an adjusting spring, the two ends of the adjusting spring are respectively in abutting connection with the adjusting spring seat and the adjusting nut, the left side of the adjusting spring seat is in abutting connection with the right end of the valve rod, and the outer wall of the side of the valve rod close to the adjusting spring cavity is in sealed connection with the valve body through a second O-shaped ring.

[0010] Preferably, a horizontal through hole is formed in the middle part of the adjusting spring seat, a through hole is correspondingly formed in the middle part of the adjusting nut, and the inner side wall of the adjusting nut is in fastening connection with the outer side wall of the valve body through threads.

[0011] Preferably, the right end of the valve rod is formed with an arc-shaped end protruding to the right, and the left side of the adjusting spring seat is formed with an arc-shaped groove matched with the arc-shaped end.

[0012] Preferably, the auxiliary spring assembly comprises a valve core, an auxiliary spring and an auxiliary spring seat, the auxiliary spring seat is in fastening connection with the valve body, the valve core is in abutting connection with the left end of the valve rod, and the two ends of the auxiliary spring are respectively in abutting connection with the valve core and the auxiliary spring seat.

[0013] Preferably, the outer side wall of the auxiliary spring seat is in fastening connection with the inner side wall of the valve body through threads, a first O-shaped ring for sealing is arranged at the connection position, a horizontal through hole is formed in the middle part of the auxiliary spring seat, and the through hole is in communication with the output end of the working medium.

[0014] Preferably, a guide groove is formed in the left side of the valve core, the right end of the auxiliary spring is embedded in the guide groove, the auxiliary spring seat is sleeved on the outer side of the valve core, the inner side wall of the right end of the auxiliary spring seat extends inward to form a connecting ring, the inner diameter of the connecting ring is smaller than the outer diameter of the valve core, and a flow channel is formed on the connecting ring.

[0015] Preferably, the left end of the valve stem is formed with a left protruding sealing blade which can be in sealing connection or separation with the valve core.

[0016] Preferably, when the pressure of the working medium applied on the valve stem is greater than the force of the adjusting spring applied on the valve stem, the valve stem moves rightward, the sealing blade separates from the valve core, and the working medium flow channel communicates with the outlet cavity.

[0017] Compared with the prior art, the present application has the following beneficial effects: The present application realizes the effect of isolating the outlet cavity and the adjusting spring cavity by arranging multiple O-rings for sealing on the valve stem and opening a lateral flow channel hole; by pushing the valve stem to move rightward, the sealing blade on the valve stem leaves the sealing surface of the valve core, the working medium is discharged from the valve body middle outlet cavity through the valve stem flow channel, the working medium does not enter the adjusting spring cavity, the right side of the valve stem is not subjected to the pressure of the working medium, and the valve stem is balanced by the rightward working medium pressure of the auxiliary spring cavity and the outlet cavity and the leftward adjusting spring force of the adjusting spring, the anti-back pressure structure is used to solve the problem of flutter caused by back pressure during pressure relief of the overpressure protection device, the stability of the safety valve is improved, the problem of reciprocating movement of the valve stem caused by back pressure of the outlet cavity during the pressure relief process of the device and the influence of back pressure on the adjusting spring cavity are effectively solved, and the stability and reliability of the safety valve are greatly improved. BRIEF DESCRIPTION OF DRAWINGS

[0018] Other features, objects and advantages of the present application will become more apparent from the following detailed description of non-limiting embodiments with reference to the attached drawings: Figure 1 The present application mainly embodies the cross-sectional view of the overpressure protection device; Figure 2 The present application mainly embodies the cross-sectional view of the valve body; Figure 3 The present application mainly embodies the cross-sectional view of the auxiliary spring seat; Figure 4 The present application mainly embodies the cross-sectional view of the overpressure protection device during pressure relief.

[0019] Shown in the figure: valve body 1, valve core 2, valve stem 3, auxiliary spring 4, auxiliary spring seat 5, first O-ring 6, second O-ring 7, adjusting spring seat 8, adjusting spring 9, adjusting nut 10, flow channel 51. DETAILED DESCRIPTION

[0020] The present application will be described in detail below with reference to specific embodiments. The following embodiments will help those skilled in the art to further understand the present application, but do not limit the present application in any form. It should be noted that those skilled in the art can make several changes and improvements without departing from the concept of the present application. These all belong to the protection scope of the present application.

[0021] As Figures 1-4 shown, according to the present application, a kind of overpressure protection device, comprising: valve body 1, valve stem 3, adjusting spring assembly and auxiliary spring assembly, the inside of valve body 1 is sequentially formed with from left to right: auxiliary spring cavity 11, outlet cavity 12 and adjusting spring cavity 13, valve stem 3 transversely through outlet cavity 12 and two ends extend into auxiliary spring cavity 11, adjusting spring cavity 13 respectively, outlet cavity 12 with adjusting spring cavity 13 is not communicated, outlet cavity 12 with auxiliary spring cavity 11 is communicated by valve stem 3;Auxiliary spring assembly is installed in auxiliary spring cavity 11, and working medium flow channel is formed in the inside of auxiliary spring assembly, and the left end of auxiliary spring assembly is tightly closed with valve stem 3;Adjusting spring assembly is installed in adjusting spring cavity 13, and the right end of adjusting spring assembly is tightly closed with valve stem 3;When the pressure of working medium applied on the left end of valve stem 3 is not greater than the force of adjusting spring assembly applied on the right end of valve stem 3, valve stem 3 is sealedly connected with auxiliary spring assembly, and overpressure protection device is in closed state;When the pressure of working medium applied on the left end of valve stem 3 is greater than the force of adjusting spring assembly applied on the right end of valve stem 3, valve stem 3 can move to right, valve stem 3 is communicated with working medium flow channel, and overpressure protection device is in open state.

[0022] The application is an anti-back pressure safety valve which isolates outlet cavity and adjusting spring cavity, can isolate outlet cavity 12 and adjusting spring cavity 13, has no flutter and good stability.

[0023] The middle part of valve stem 3 is provided with first through hole communicated with outlet cavity 12, the left side of valve stem 3 is provided with second through hole communicated with auxiliary spring cavity 11 and first through hole, and the outer wall of the side of valve stem 3 close to auxiliary spring cavity 11 is sealedly connected with valve body 1 by second O-shaped ring 7.

[0024] Adjusting spring assembly is tightly installed in the right side of valve body 1 by adjusting nut 10, and adjusting spring assembly comprises adjusting spring seat 8 and adjusting spring 9, the two ends of adjusting spring 9 are tightly closed with adjusting spring seat 8 and adjusting nut 10 respectively, the left side of adjusting spring seat 8 is tightly closed with the right end of valve stem 3, and the outer wall of the side of valve stem 3 close to adjusting spring cavity 13 is sealedly connected with valve body 1 by second O-shaped ring 7. The spring force of adjusting spring 9 depends on the setting pressure of safety valve.

[0025] Horizontal through hole is formed in the middle part of adjusting spring seat 8, and corresponding through hole is formed in the middle part of adjusting nut 10, and the inner side wall of adjusting nut 10 is tightly connected with the outer side wall of valve body 1 by thread.

[0026] The right end of valve stem 3 is formed with arc-shaped end protruding to right, and the left side of adjusting spring seat 8 is formed with arc-shaped groove matched with arc-shaped end.

[0027] The auxiliary spring assembly comprises a valve core 2, an auxiliary spring 4 and an auxiliary spring seat 5, the auxiliary spring seat 5 is fastened to the valve body 1, the valve core 2 is tightly connected to the left end of the valve rod 3, and the two ends of the auxiliary spring 4 are tightly connected to the valve core 2 and the auxiliary spring seat 5 respectively. The spring force of the auxiliary spring 4 depends on the sealing specific pressure of the sealing surface of the valve core 2, and the sealing specific pressure depends on the sealing material used, and the sealing specific pressure range corresponding to each sealing material is different, for example, the sealing specific pressure range of polytrifluorochloroethylene is 35-40 MPa, and the setting pressure of the safety valve is a design parameter determined by actual application.

[0028] The outer side wall of the auxiliary spring seat 5 is fastened to the inner side wall of the valve body 1 through threads, and a first O-ring 6 for sealing is arranged at the connection position, and a horizontal through hole is formed in the middle of the auxiliary spring seat 5, and the through hole is communicated with the output end of the working medium.

[0029] A guide groove is formed on the left side of the valve core 2, the right end of the auxiliary spring 4 is embedded in the guide groove, the auxiliary spring seat 5 is sleeved on the outer side of the valve core 2, and the inner side wall of the right end of the auxiliary spring seat 5 extends inward to form a connecting ring, the inner diameter of the connecting ring is smaller than the outer diameter of the valve core 2, and a flow channel 51 is formed on the connecting ring.

[0030] A left protruding sealing blade is formed on the left end of the valve rod 3, and the sealing blade can be connected or separated from the valve core 2.

[0031] When the pressure of the working medium applied on the valve rod 3 is greater than the force of the adjusting spring 9 applied on the valve rod 3, the valve rod 3 moves to the right, the sealing blade is separated from the valve core 2, and the working medium flow channel is communicated with the outlet cavity 12.

[0032] When the upstream overpressure of the device, the working medium passes through the auxiliary spring cavity 11, opens the valve rod 3, and flows into the first through hole from the side through the second through hole in the valve rod 3 and then flows into the outlet cavity 12. The valve rod 3 is sleeved with two second O-rings 7, which isolate the auxiliary spring cavity 11, the outlet cavity 12 and the adjusting spring cavity 13. The medium does not pass through the adjusting spring cavity 13, so the device is not affected by the outlet pressure, and the valve rod 3 will not reciprocate due to the counter pressure.

[0033] In the assembly, the two second O-rings 7 are sleeved on the left outer wall of the valve rod 3, the first O-ring 6 is sleeved on the auxiliary spring seat 5, then the auxiliary spring 4 and the valve core 2 are assembled into the auxiliary spring seat 5, the valve rod 3 is assembled into the valve body 1 from the left side, the assembled auxiliary spring seat assembly is assembled into the valve body 1, and the auxiliary spring seat 5 is fastened to the valve body 1 through threads; then the adjusting spring seat 8 and the adjusting spring 9 are assembled into the right side of the valve body 1 in sequence, and the adjusting nut 10 is connected to the right side of the valve body 1 through threads.

[0034] The safety valve of the present application is in a normally closed state, and the overpressure working medium enters the secondary spring cavity 11 from the left side of the secondary spring seat 5 and pushes the valve stem 3 to move to the right through the flow channel 51, the sealing edge on the valve stem 3 leaves the sealing surface of the valve core 2, and the adjusting spring 9 is compressed by the adjusting nut 10, and since the working medium does not enter the adjusting spring cavity 13, the right side of the valve stem 3 is not subjected to the pressure of the working medium, and the valve stem 3 is balanced by the right working medium pressure of the secondary spring cavity 11 and the outlet cavity 12 and the left adjusting spring force of the adjusting spring 9, and the working medium is discharged from the middle outlet cavity 12 of the valve body 1 through the flow channel of the valve stem 3; after the overpressure is discharged, the valve stem 3 moves to the left under the action of the adjusting spring force, the safety valve is closed, and the system pressure returns to normal.

[0035] The present application does not necessarily consist of the above 10 structures, and the key of the present application is to solve the problem of vibration caused by counter pressure during pressure relief of the overpressure protection device by using the anti-counter pressure structure, thereby improving the stability of the safety valve. Further, the present application does not necessarily discharge the medium directly from the outlet, and since it is not affected by the counter pressure, the outlet can be connected to a long pipeline as needed to discharge the medium to a specified position.

[0036] The present application achieves the effect of isolating the outlet cavity 12 and the adjusting spring cavity 13 by providing a plurality of O-rings for sealing on the valve stem 3 and opening the lateral flow channel holes, effectively solving the problem of reciprocating movement of the valve stem 3 caused by the counter pressure of the outlet cavity 12 during the pressure relief process of the device and the problem of the adjusting spring cavity 13 being affected by the counter pressure, thereby greatly improving the stability and reliability of the safety valve.

[0037] In the description of the present application, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0038] The specific embodiments of the present application have been described above. It should be understood that the present application is not limited to the above specific embodiments, and those skilled in the art can make various changes or modifications within the scope of the claims, which does not affect the essential content of the present application. The embodiments of the present application and the features in the embodiments can be arbitrarily combined with each other without conflict.

Claims

1. An overpressure protection device, characterized in that, include: The valve body (1), valve stem (3), adjusting spring assembly and auxiliary spring assembly are formed in the valve body (1) from left to right as follows: auxiliary spring cavity (11), outlet cavity (12) and adjusting spring cavity (13). The valve stem (3) passes through the outlet cavity (12) laterally and extends to the auxiliary spring cavity (11) and adjusting spring cavity (13) at both ends respectively. The outlet cavity (12) and the adjusting spring cavity (13) are not connected. The outlet cavity (12) and the auxiliary spring cavity (11) are connected through the valve stem (3). The auxiliary spring assembly is installed inside the auxiliary spring cavity (11), and a working medium flow channel is formed inside the auxiliary spring assembly. The auxiliary spring assembly abuts against the left end of the valve stem (3). The adjusting spring assembly is installed in the adjusting spring cavity (13), and the adjusting spring assembly abuts against the right end of the valve stem (3); When the pressure of the working medium applied to the left end of the valve stem (3) is not greater than the force applied to the right end of the valve stem (3) by the adjusting spring assembly, the valve stem (3) is sealed to the auxiliary spring assembly, and the overpressure protection device is in the closed state; When the pressure of the working medium applied to the left end of the valve stem (3) is greater than the force applied to the right end of the valve stem (3) by the adjusting spring assembly, the valve stem (3) can move to the right, the valve stem (3) is connected to the working medium flow channel, and the overpressure protection device is in the open state.

2. The overpressure protection device as described in claim 1, characterized in that, The valve stem (3) has a first through hole in the middle that communicates with the outlet (12). The valve stem (3) has a second through hole in the left side that communicates with both the sub-spring cavity (11) and the first through hole. The outer wall of the valve stem (3) near the sub-spring cavity (11) is sealed to the valve body (1) by a second O-ring (7).

3. The overpressure protection device as described in claim 1, characterized in that, The adjusting spring assembly is fastened to the inside of the right side of the valve body (1) by adjusting nut (10). The adjusting spring assembly includes: adjusting spring seat (8) and adjusting spring (9). The two ends of the adjusting spring (9) are respectively abutted against the adjusting spring seat (8) and adjusting nut (10). The left side of the adjusting spring seat (8) is abutted against the right end of the valve stem (3). The outer wall of the valve stem (3) near the adjusting spring cavity (13) is sealed to the valve body (1) by a second O-ring (7).

4. The overpressure protection device as described in claim 3, characterized in that, The adjusting spring seat (8) has a horizontal through hole in the middle, and the adjusting nut (10) has a corresponding through hole in the middle. The inner wall of the adjusting nut (10) is fastened to the outer wall of the valve body (1) by threads.

5. The overpressure protection device as described in claim 3, characterized in that, The valve stem (3) has a right-protruding arc-shaped end, and the adjusting spring seat (8) has an arc-shaped groove on the left side that matches the arc-shaped end.

6. The overpressure protection device as described in claim 3, characterized in that, The secondary spring assembly includes: a valve core (2), a secondary spring (4) and a secondary spring seat (5). The secondary spring seat (5) is fastened to the valve body (1). The valve core (2) abuts against the left end of the valve stem (3). The two ends of the secondary spring (4) are respectively abutted against the valve core (2) and the secondary spring seat (5).

7. The overpressure protection device as described in claim 6, characterized in that, The outer wall of the auxiliary spring seat (5) is fastened to the inner wall of the valve body (1) by threads, and a first O-ring (6) for sealing is provided at the connection. A horizontal through hole is formed in the middle of the auxiliary spring seat (5), and the through hole is connected to the output end of the working medium.

8. The overpressure protection device as described in claim 7, characterized in that, A guide groove is formed on the left side of the valve core (2), the right end of the secondary spring (4) is embedded in the guide groove, the secondary spring seat (5) is sleeved on the outside of the valve core (2), and the inner sidewall of the right end of the secondary spring seat (5) extends inward to form a connecting ring. The inner diameter of the connecting ring is smaller than the outer diameter of the valve core (2), and a flow channel (51) is formed on the connecting ring.

9. The overpressure protection device as described in claim 8, characterized in that, The left end of the valve stem (3) has a sealing edge protruding to the left, which can be sealed to or separated from the valve core (2).

10. The overpressure protection device as described in claim 9, characterized in that, When the pressure of the working medium applied to the valve stem (3) is greater than the force applied to the valve stem (3) by the adjusting spring (9), the valve stem (3) moves to the right, the sealing edge separates from the valve core (2), and the working medium flow channel communicates with the outlet cavity (12).

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