Low-temperature stop valve

Abstract

The utility model discloses a low-temperature stop valve which comprises a valve body assembly, a valve rod assembly, a valve clack assembly and a valve deck. A first channel and a second channel are arranged in the lower part of the valve body assembly, a blocking part with a connecting port is arranged between the top of the inner end of the first channel and the bottom of the inner end of the second channel, and the first channel is communicated with the second channel through the connecting port; a main channel is vertically arranged in the valve body assembly, an upper channel is vertically arranged in the valve cover, the valve rod assembly penetrates through the main channel and the upper channel, a first sealing assembly set is arranged between the valve rod assembly and the main channel, and a second sealing assembly set is arranged between the valve rod assembly and the upper channel. The valve clack assembly is arranged at the bottom of the valve rod assembly, and a valve rod assembly displacement adjusting structure which enables the valve rod assembly to move upwards or downwards to the needed position and maintain the valve rod assembly at the position is arranged in the upper channel. And a self-tightening structure is arranged on the valve clack assembly. The valve has the advantages of being good in sealing performance, convenient, simple and controllable to control and the like.

Description

TECHNICAL FIELD

[0001] The utility model relates to low temperature valve technical field especially relates to a low temperature stop valve. BACKGROUND

[0002] Low temperature stop valve is a kind of low temperature valve that works in low temperature hydrogen or liquid hydrogen medium, is used to connect or cut off the medium of pipeline, it needs to have extremely low temperature resistance, excellent sealing, accurate operation control and other conditions, to ensure the safe supply and accurate control of liquid hydrogen, especially the low temperature stop valve applied in liquid hydrogen storage tank and transport vehicle, low temperature stop valve is in vibration working condition environment for a long time, more to ensure the safety and controllability in the process of liquid hydrogen storage and transportation, thus urgently needing to develop a kind of low temperature stop valve with good sealing performance, can be easily opened and closed under low temperature environment. SUMMARY

[0003] The utility model needs to solve the technical problem: provide a kind of low temperature stop valve with good sealing performance, easy and simple to control, the low temperature stop valve can be easily opened and closed under low temperature environment.

[0004] In order to improve the sealing performance of low temperature stop valve, and make the low temperature stop valve can be easily opened and closed under low temperature environment, the technical scheme of the utility model is: a kind of low temperature stop valve, comprising: valve body assembly, valve stem assembly, valve clapper assembly and valve cover;First channel and second channel are arranged in the lower part of the valve body assembly;The first channel outer end penetrates the outer lateral wall of valve body assembly, and first opening is formed on the outer lateral wall of valve body assembly;The second channel outer end penetrates the outer lateral wall of valve body assembly, and second opening is formed on the outer lateral wall of valve body assembly;Barrier portion is arranged between the first channel inner end top and the second channel inner end bottom, and connecting port is arranged on the barrier portion, and the first channel and the second channel are communicated by connecting port;Main channel is vertically arranged in the valve body assembly, and the main channel top end penetrates the valve body assembly top end, and the main channel bottom end is communicated with connecting port;

[0005] The valve cover is sealedly connected to the top end of the valve body assembly, and an upper channel is vertically arranged in the valve cover, the upper channel is communicated with the main channel, and the upper channel and the main channel are coaxial;

[0006] The valve stem assembly is arranged in the main channel and the upper channel, and first sealing assembly group is arranged between the valve stem assembly and the main channel, and second sealing assembly group is arranged between the valve stem assembly and the upper channel;

[0007] The valve disc assembly is arranged at the bottom of the valve stem assembly, and a valve stem assembly displacement adjusting structure is arranged in the upper passage to move the valve stem assembly upward or downward to a desired position and maintain it at the position; the valve stem assembly can be moved downward by the valve stem assembly displacement adjusting structure to block the valve disc assembly on the connecting port, so that the first passage and the second passage are blocked from being connected; or the valve stem assembly can be moved upward by the valve stem assembly displacement adjusting structure to move the valve disc assembly away from the connecting port, so that the first passage and the second passage are connected;

[0008] A self-tightening structure is arranged on the valve disc assembly, and when the valve disc assembly is blocked on the connecting port, the self-tightening structure enables the valve disc assembly to be pressed on the connecting port with a certain pressure, which can ensure that the valve disc assembly is always blocked on the connecting port and will not be loose. Once the valve disc is loose and a gap exists between the valve disc and the connecting port, the first passage and the second passage will be connected due to the existence of the gap, and the complete cut-off phenomenon will occur, and there will be a leakage problem.

[0009] Further, the low-temperature stop valve, wherein the self-tightening structure is that the valve disc assembly is hinged to the bottom of the valve stem assembly by a pin shaft, and a first installation space, a second installation space and a third installation space are sequentially arranged from top to bottom on the top surface of the valve disc assembly at the bottom surface of the valve stem assembly, a pressing block is arranged in the second installation space and the third installation space, a limiting protrusion is arranged on the top of the pressing block extending out of the second installation space and protruding outward and larger than the opening of the second installation space, and a spring is sleeved on the pressing block at the second installation space; when the valve disc assembly is blocked on the connecting port, the limiting protrusion is pressed on the bottom surface of the valve stem assembly under the elastic force of the spring, and the valve disc assembly is pressed on the connecting port.

[0010] Further, the low-temperature stop valve, wherein the spring is a plurality of butterfly springs, and each butterfly spring is sleeved on the pressing block.

[0011] Further, the low-temperature stop valve, wherein the bottom surface of the valve stem assembly is a downwardly protruding spherical curved surface, and the limiting protrusion is pressed on the spherical curved surface. The cooperation between the limiting protrusion and the spherical curved surface enables the valve disc to have a self-centering function.

[0012] Further, the low-temperature stop valve, wherein the connecting port is sequentially composed of a conical passage with a trumpet-shaped port upward and a circular hole passage from top to bottom;

[0013] The valve disc assembly comprises a valve disc body, a threaded connecting rod arranged at the bottom of the valve disc body, and a plurality of downwardly protruding protruding points arranged on the bottom surface of the valve disc body. A valve disc sealing member is fixed by a locking nut after being sleeved on the threaded connecting rod, and each protruding point is pressed on the valve disc sealing member. When the valve disc assembly is pressed on the connecting port, the valve disc sealing member is in sealing contact with the inner side wall of the conical passage.

[0014] Further, the low-temperature stop valve as claimed in the preceding claim, wherein the outer side wall of the valve disc sealing member is provided with a conical surface with a large diameter at the upper portion and a small diameter at the lower portion, and the conical surface of the valve disc sealing member is in close contact with the inner side wall of the conical passage when the valve disc assembly abuts against the connecting port.

[0015] Further, the low-temperature stop valve as claimed in the preceding claim, wherein the first sealing assembly comprises a guide and liquid-separation assembly.

[0016] The valve rod assembly is composed of a main valve rod and a connecting rod connected to the bottom of the main valve rod, and the valve disc assembly is arranged at the bottom of the connecting rod, and an upper segment external thread segment is arranged at the upper segment of the connecting rod.

[0017] The guide and liquid-separation assembly comprises a guide sleeve, and the top surface of the guide sleeve is sequentially provided with a sealing gasket mounting groove, an internal thread connecting hole and an elastic pad mounting groove from top to bottom, and a lower portion through hole; a sealing gasket is arranged in the sealing gasket mounting groove, and an elastic pad is arranged in the elastic pad mounting groove; after the guide sleeve is screwed on the upper segment external thread segment through the internal thread connecting hole, the guide sleeve is in sealing contact with the bottom of the main valve rod through the sealing gasket; a step is arranged on the connecting rod, the elastic pad is clamped in the step and the elastic pad mounting groove, and the elastic pad applies an upward force to the step and a downward force to the elastic pad mounting groove, so that the thread teeth of the internal thread connecting hole and the thread teeth of the upper segment external thread segment are more tightly engaged, thereby preventing the thread teeth of the internal thread connecting hole and the thread teeth of the upper segment external thread segment from being loose.

[0018] At least one guide ring mounting groove is formed on the outer circumferential side wall of the guide sleeve, and a guide ring is arranged in each guide ring mounting groove; each guide ring is in contact with the main passage, and each guide ring is provided with a through groove for only allowing liquefied gas to pass through.

[0019] Further, the low-temperature stop valve as claimed in the preceding claim, wherein a connecting piece mounting groove is formed downward at the top end of the main passage, and a connecting piece is arranged in the connecting piece mounting groove; the top portion of the connecting piece and the valve cover and the connecting piece and the connecting piece mounting groove are all sealed by upper sealing gaskets.

[0020] A heat insulation sleeve mounting groove and a lower portion passage for the valve rod assembly are sequentially formed downward on the top surface of the connecting piece, and the heat insulation sleeve is arranged on the valve rod assembly and arranged in the heat insulation sleeve mounting groove. The arrangement of the heat insulation sleeve can not only play a heat insulation role, but also play a role in centralizing the valve rod assembly.

[0021] Further, the low-temperature stop valve as claimed in the preceding claim, wherein the lower segment of the valve rod assembly has a hollow sealed cavity; a bellows is sleeved on the valve rod assembly, the upper end of the bellows is fixedly connected to the bottom of the connecting piece, and the lower end of the bellows is connected to the side wall of the valve rod assembly above the sealed cavity.

[0022] A guide heat shield is sleeved on the bellows and the valve stem assembly below the bellows;

[0023] The valve body assembly comprises an outer wrapping heat insulation layer and a jacket assembly.

[0024] Further, the low-temperature stop valve has the valve stem assembly composed of an upper valve stem and a main valve stem, the upper valve stem is provided with a T-shaped slot at the bottom, and the main valve stem is provided with a T-shaped block embedded in the T-shaped slot.

[0025] The second sealing assembly group comprises a valve stem sealing assembly arranged between the upper valve stem and the upper channel.

[0026] The valve stem assembly displacement adjusting structure comprises an outer connecting threaded section arranged on the upper valve stem and an inner connecting threaded section arranged at the top end of the upper channel; a valve stem nut with an inner threaded hole matched with the outer connecting threaded section is screwed on the outer connecting threaded section, the lower end of the valve stem nut is outwardly folded to form a lower flange, and after a thrust ball bearing and a compression nut are sleeved on the valve stem nut, the outer threaded section on the compression nut is screwed with the inner connecting threaded section to limit the position of the valve stem nut, so that the valve stem nut can only rotate and cannot move up and down.

[0027] A hand wheel is fixedly installed on the valve stem nut outside the top of the compression nut.

[0028] The beneficial effects of the low-temperature stop valve are as follows: when the low-temperature stop valve is in a closed state, the self-tightening structure arranged on the valve disc assembly can provide a downward force on the valve disc assembly by a spring, so that the valve disc assembly and the connecting port can be effectively sealed, and even if the low-temperature stop valve is in a vibration working condition for a long time, the valve disc assembly can still be well sealed; the spring can provide an upward force on the valve stem assembly, and the upward force finally acts on the outer connecting threaded section on the upper valve stem and the inner threaded hole on the valve stem nut, so that the threads on the outer connecting threaded section on the upper valve stem and the threads on the inner threaded hole on the valve stem nut are more tightly engaged, so as to ensure that even if the low-temperature stop valve is in a vibration working condition for a long time, the valve stem nut will not be loosened, the valve stem assembly will not move up, and the valve will not be tightly closed, thereby greatly improving the sealing effect of the low-temperature stop valve in the closed state and improving the safe use performance of the low-temperature stop valve. BRIEF DESCRIPTION OF DRAWINGS

[0029] Figure 1 is a structural schematic view of the low-temperature stop valve.

[0030] Figure 2 is a structural schematic view of the valve body assembly.

[0031] Figure 3is a schematic view of a connection structure between a valve stem assembly, a valve disc, and a guide and fluid isolation assembly.

[0032] Figure 4 is Figure 3 a schematic view of a partial structure.

[0033] Figure 5 is Figure 4 a schematic view of a partial enlarged structure of part A in the figure.

[0034] Figure 6 is Figure 1 a schematic view of a partial enlarged structure of the upper half.

[0035] Figure 7 is Figure 1 a schematic view of a partial enlarged structure of the lower half. DETAILED DESCRIPTION

[0036] The technical solutions of the utility model will be described in further detail below in combination with the drawings and preferred embodiments.

[0037] In the following, example embodiments will be described more fully with reference to the accompanying drawings, in which example embodiments can be embodied in different forms and should not be construed as being limited to the embodiments set forth herein. Rather, the purpose of the embodiments is to explain the present disclosure fully and completely, and to enable those skilled in the art to fully understand the scope of the present disclosure. In the case of no conflict, the embodiments of the present disclosure and the features in the embodiments can be combined with each other. Embodiment one

[0038] As shown in Figure 1 , Figure 2 and Figure 7 , the low-temperature cut-off valve in the embodiment comprises a valve body assembly 1, a valve stem assembly 2, a valve disc assembly 3, and a valve cover 4. A first channel 14 and a second channel 15 are arranged in the lower part of the valve body assembly 1. The outer end of the first channel 14 penetrates through the outer side wall of the valve body assembly 1, and a first opening 141 is formed on the outer side wall of the valve body assembly 1. The outer end of the second channel 15 penetrates through the outer side wall of the valve body assembly 1, and a second opening 151 is formed on the outer side wall of the valve body assembly 1. A blocking part 16 is arranged between the top of the inner end of the first channel 14 and the bottom of the inner end of the second channel 15, and a connecting port 17 is arranged on the blocking part 16. The first channel 14 and the second channel 15 are communicated through the connecting port 17. A main channel 11 is arranged vertically in the valve body assembly 1, the top end of the main channel 11 penetrates through the top end of the valve body assembly 1, and the bottom end of the main channel 11 is communicated with the connecting port 17.

[0039] As shown in Figure 1 , Figure 2 , Figure 6 and Figure 7As shown, the valve cover 4 is sealingly connected to the top end of the valve body assembly 1 in this embodiment, and the sealingly connected manner is through the detachable fastening connection manner of the upper sealing gasket 43 + bolt connection assembly 42. An upper passage 41 is vertically arranged in the valve cover 4, which is in communication with the main passage 11 and coaxial with the main passage 11.

[0040] The valve stem assembly 2 passes through the main passage 11 and the upper passage 41, and a first sealing assembly group is arranged between the valve stem assembly 2 and the main passage 11, and a second sealing assembly group is arranged between the valve stem assembly 2 and the upper passage 41.

[0041] As shown in Figure 1 , Figure 3 , Figure 4 and Figure 7 , the valve disc assembly 3 is arranged at the bottom of the valve stem assembly 2 in this embodiment, and a valve stem assembly displacement adjusting structure is arranged in the upper passage 41 to move the valve stem assembly 2 upward or downward to the required position and maintain it at the position; the valve stem assembly 2 can be moved downward by the valve stem assembly displacement adjusting structure to make the valve disc assembly 3 block the connecting port 17, so that the first passage 14 and the second passage 15 are blocked and not communicated, at this time the low-temperature stop valve is in the closed state; or the valve stem assembly 2 can be moved upward by the valve stem assembly displacement adjusting structure to make the valve disc assembly 3 away from the connecting port 17, so that the first passage 14 and the second passage 15 are communicated, at this time the low-temperature stop valve is in the open state.

[0042] A self-tightening structure is arranged on the valve disc assembly 3, which makes the valve disc assembly 3 abut on the connecting port 17 with a certain pressure when the valve disc assembly 3 blocks the connecting port 17.

[0043] The self-tightening structure in this embodiment is that the valve disc assembly 3 is hinged to the bottom of the valve stem assembly 2 through a pin shaft 34, and a first mounting space 311, a second mounting space 312 and a third mounting space 313 are sequentially arranged from top to bottom on the top surface of the valve disc assembly 3 at the bottom surface of the valve stem assembly 2, a pressing block 33 passes through the second mounting space 312 and the third mounting space 313, a limiting block 331 protruding outward and larger than the opening of the second mounting space 312 is arranged on the top of the pressing block 33 extending above the second mounting space 312, and a spring is sleeved on the pressing block at the second mounting space 312.

[0044] When the valve disc assembly 3 is hinged to the bottom of the valve stem assembly 2 by the pin shaft 34, a slight gap will inevitably exist at the hinging position of the pin shaft 34, so that the valve disc assembly 3 has a fine up-and-down adjustment distance. When the valve disc assembly 3 is tightly closed on the connecting port 17, the spring exerts an upward force on the limiting block 331 and a downward force on the step surface between the second mounting space 312 and the third mounting space 313. Under the elastic force of the spring, the limiting block 331 abuts against the bottom surface of the valve stem assembly 2, and the valve disc assembly 3 abuts against the connecting port 17, so that the valve disc assembly 3 is tightly pressed on the connecting port 17.

[0045] In the embodiment, the spring preferably comprises a plurality of butterfly springs 32.

[0046] As shown in Figure 2 , the connecting port 17 in the embodiment comprises, from top to bottom, a trumpet-shaped upward conical passage 171 and a circular hole passage 172. As shown in Figure 4 and Figure 5 , the valve disc assembly 3 comprises a valve disc body 31, a threaded connecting rod 314 arranged at the bottom of the valve disc body 31, and a plurality of downward protruding protruding points 315 arranged on the bottom surface of the valve disc body 31. A valve disc sealing member 35 is fixed on the threaded connecting rod 314 by a locking nut 36, and each protruding point 315 presses on the valve disc sealing member 35. When the valve disc assembly 3 abuts against the connecting port 17, the valve disc sealing member 35 is in sealing contact with the inner side wall of the conical passage 171.

[0047] More preferably, the outer side wall profile of the valve disc sealing member 35 has an upper portion with a large diameter and a lower portion with a small diameter, and the valve disc assembly 3 has a conical surface 351 on the valve disc sealing member 35. When the valve disc assembly 3 abuts against the connecting port 17, the conical surface 351 on the valve disc sealing member 35 is in close contact with the inner side wall of the conical passage 171. When the valve stem assembly 2 is moved downward by the valve stem assembly displacement adjustment structure to make the valve disc assembly 3 tightly close on the connecting port 17, the presence of the spring causes the valve disc sealing member 35 to abut against the inner side wall of the conical passage 171 with a certain pressure, thereby ensuring that the valve disc assembly 3 and the connecting port 17 can be effectively sealed. In addition, in combination with the cooperation of the valve disc sealing member 35 and the inner side wall of the conical passage 171 and the protruding points 315, the sealing between the valve disc assembly 3 and the connecting port 17 is more reliable.

[0048] When the valve disc assembly 3 is hinged to the bottom of the valve stem assembly 2 by the pin shaft 34, the valve disc assembly 3 also has a small amount of swing amplitude that can be adjusted. Therefore, in order to further improve the sealing performance between the valve disc assembly 3 and the connecting port 17, as shown in Figure 4 , a more preferred solution is to arrange the bottom surface of the valve stem assembly 2 in a downwardly protruding spherical curved surface shape, and the limiting block 331 abuts against the spherical curved surface 231. At this time, the valve disc assembly 3 can automatically align under the action of the elastic force, having a self-centering effect. Embodiment Two

[0049] As shown in Figure 1 , Figure 2 and Figure 7 , the low-temperature stop valve in this embodiment includes a valve body assembly 1, a valve stem assembly 2, a valve disc assembly 3, and a valve cover 4. A first passage 14 and a second passage 15 are provided in the lower part of the valve body assembly 1. The outer end of the first passage 14 penetrates through the outer lateral wall of the valve body assembly 1, forming a first opening 141 on the outer lateral wall of the valve body assembly 1. The outer end of the second passage 15 penetrates through the outer lateral wall of the valve body assembly 1, forming a second opening 151 on the outer lateral wall of the valve body assembly 1. A blocking part 16 is provided between the top of the inner end of the first passage 14 and the bottom of the inner end of the second passage 15, and a connecting port 17 is provided on the blocking part 16, through which the first passage 14 and the second passage 15 are connected. A main passage 11 is vertically provided in the valve body assembly 1, the top end of which penetrates through the top end of the valve body assembly 1, and the bottom end of which is connected to the connecting port 17.

[0050] As shown in Figure 1 , Figure 2 and Figure 7 , the valve cover 4 in this embodiment is sealingly connected to the top end of the valve body assembly 1, and the sealing connection is achieved by the detachable fastening connection of the upper sealing gasket 43 + bolt connection assembly 42. An upper passage 41 is vertically provided in the valve cover 4, which is connected to the main passage 11 and coaxial with the main passage 11.

[0051] As shown in Figure 1 , Figure 3 , Figure 4 and Figure 7 , the valve disc assembly 3 in this embodiment is provided at the bottom of the valve stem assembly 2, and a valve stem assembly displacement adjustment structure is provided in the upper passage 41 to move the valve stem assembly 2 up or down to the desired position and maintain it at that position; the valve stem assembly 2 can be moved downward by the valve stem assembly displacement adjustment structure to block the valve disc assembly 3 on the connecting port 17, so that the first passage 14 and the second passage 15 are blocked and not connected; or the valve stem assembly 2 can be moved upward by the valve stem assembly displacement adjustment structure to move the valve disc assembly 3 away from the connecting port 17, so that the first passage 14 and the second passage 15 are connected. A self-tightening structure is provided on the valve disc assembly 3, which allows the valve disc assembly 3 to be pressed against the connecting port 17 with a certain pressure when the valve disc assembly 3 is blocked on the connecting port 17.

[0052] The valve stem assembly 2 penetrates through the main passage 11 and the upper passage 41, and a first sealing assembly group is provided between the valve stem assembly 2 and the main passage 11, and a second sealing assembly group is provided between the valve stem assembly 2 and the upper passage 41.

[0053] The first sealing assembly group comprises a guide and liquid isolation assembly 5.

[0054] As shown in Figure 3 and Figure 4 , the valve stem assembly 2 is composed of a main valve stem 22 and a connecting rod 23 connected to the bottom of the main valve stem 22, wherein the lower section of the main valve stem 22 has a hollow sealed cavity 222, which is provided to reduce heat transfer. In order to facilitate the processing of the sealed cavity 222, the sealed cavity 222 is processed upward from the bottom of the main valve stem 22. In order to seal the sealed cavity 222, the top of the connecting rod 23 has a shaft shoulder 231 capable of sealing the sealed cavity 222, and the shaft shoulder 231 is usually welded to seal the sealed cavity 222. Here, for the sake of description, the lower end face of the shaft shoulder 231 is uniformly defined as the bottom of the main valve stem.

[0055] The valve disc assembly 3 is arranged at the bottom of the connecting rod 23, and an upper section external thread section is arranged at the upper section of the connecting rod 23. Figure 4 and Figure 7 As shown in and

[0056] , the guide and liquid isolation assembly 5 comprises a guide sleeve 51, and the top surface of the guide sleeve 51 is sequentially provided with a sealing gasket mounting groove 511, an internal thread connecting hole 512, an elastic pad mounting groove 513, and a lower through hole 514 from top to bottom. A sealing gasket 52 is placed in the sealing gasket mounting groove 511, and an elastic pad 53 is placed in the elastic pad mounting groove 513. After the guide sleeve 51 is screwed on the upper section external thread section through the internal thread connecting hole, the guide sleeve 51 and the bottom of the main valve stem are in sealing contact through the sealing gasket 52.

[0057] In view of the difficulty in processing the thread with self-locking function, the upper section external thread section on the connecting rod 23 and the internal thread connecting hole 512 on the guide sleeve 51 both adopt threads with easy processing and without self-locking function. A step 232 is arranged on the connecting rod 23, and the elastic pad 53 is clamped in the step 232 and the elastic pad mounting groove 513. At this time, the elastic force of the elastic pad 53 will give the connecting rod 23 and the guide sleeve 51 an acting force, so that the threads of the upper section external thread section and the threads of the internal thread connecting hole 512 are engaged more tightly, thereby ensuring that the guide sleeve 51 will not be easily loosened. Embodiment Three

[0058] As shown in Figure 1 , Figure 2 andFigure 7 As shown in the drawings, the low-temperature cut-off valve in the embodiment includes a valve body assembly 1, a valve stem assembly 2, a valve disc assembly 3, and a valve cover 4. A first passage 14 and a second passage 15 are arranged in the lower part of the valve body assembly 1. The outer end of the first passage 14 penetrates through the outer lateral wall of the valve body assembly 1 to form a first opening 141 on the outer lateral wall of the valve body assembly 1. The outer end of the second passage 15 penetrates through the outer lateral wall of the valve body assembly 1 to form a second opening 151 on the outer lateral wall of the valve body assembly 1. A blocking part 16 is arranged between the top of the inner end of the first passage 14 and the bottom of the inner end of the second passage 15. A connecting port 17 is arranged on the blocking part 16. The first passage 14 and the second passage 15 are connected through the connecting port 17. A main passage 11 is arranged vertically in the valve body assembly 1. The top end of the main passage 11 penetrates through the top end of the valve body assembly 1. The bottom end of the main passage 11 is connected with the connecting port 17.

[0059] As shown in the drawings, Figure 1 , Figure 2 and Figure 7 , the valve cover 4 in the embodiment is sealingly connected with the top end of the valve body assembly 1. Here, the sealingly connected manner is the detachable fastening connection manner of the upper sealing gasket 43 + bolt connection assembly 42. An upper passage 41 is arranged vertically in the valve cover 4. The upper passage 41 is connected with the main passage 11. The upper passage 41 is coaxial with the main passage 11.

[0060] The valve stem assembly 2 penetrates through the main passage 11 and the upper passage 41. A first sealing assembly group is arranged between the valve stem assembly 2 and the main passage 11. A second sealing assembly group is arranged between the valve stem assembly 2 and the upper passage 41.

[0061] As shown in the drawings, Figure 1 , Figure 3 , Figure 4 and Figure 7 , the valve disc assembly 3 in the embodiment is arranged at the bottom of the valve stem assembly 2. A valve stem assembly displacement adjustment structure is arranged in the upper passage 41 to move the valve stem assembly 2 upward or downward to a desired position and maintain it at the position. The valve stem assembly 2 can be moved downward through the valve stem assembly displacement adjustment structure to block the valve disc assembly 3 on the connecting port 17, so that the first passage 14 and the second passage 15 are blocked and not connected. Or the valve stem assembly 2 can be moved upward through the valve stem assembly displacement adjustment structure to move the valve disc assembly 3 away from the connecting port 17, so that the first passage 14 and the second passage 15 are connected.

[0062] As shown in the drawings, Figure 1 , Figure 2 and Figure 6As shown, in this embodiment, a connecting piece mounting groove 111 is formed at the top end of the main channel 11, and the connecting piece 6 is placed in the connecting piece mounting groove 111, and the top of the connecting piece 6 and the valve cover 4 are sealed by the upper sealing gasket 43, and the connecting piece 6 and the connecting piece mounting groove 111 are also sealed by the upper sealing gasket 43.

[0063] As shown, a heat insulation sleeve mounting groove 61 and a lower channel 62 for the valve stem assembly 2 are formed in sequence on the top surface of the connecting piece 6, and the heat insulation sleeve 7 is placed in the heat insulation sleeve mounting groove 61 and passes over the valve stem assembly 2, and because the valve stem assembly 2 is relatively long, the above-mentioned heat insulation sleeve 7 can ensure concentricity and has the function of heat insulation and centralizing.

[0064] The lower section of the valve stem assembly 2 has a hollow sealed cavity 222; a bellows 8 is sleeved on the valve stem assembly 2, and the upper end of the bellows 8 is fixedly connected to the bottom of the connecting piece 6, and the lower end of the bellows 8 is connected to the side wall of the valve stem assembly 2 above the sealed cavity 222.

[0065] The valve body assembly 1 includes an external heat preservation layer 12 and a jacket assembly 13.

[0066] As shown in Figure 2 and Figure 6 , a guide heat blocking sleeve 9 is sleeved on the bellows 8 and the valve stem assembly 2 below the bellows 8, and a flange heat dissipation assembly 10 composed of a flange 101, a heat dissipation plate 102 and a connecting pipe 103 is arranged on the upper part of the valve body 1, and the flange heat dissipation assembly 10 is usually welded on the top end of the valve body assembly 1 by welding, and for the convenience of description, the flange heat dissipation assembly 10 is also regarded as part of the valve body assembly 1. The heat dissipation plate 102 and the jacket upper ring plate 131 on the jacket assembly 13 have the function of heat dissipation and can prevent low-temperature stop valve from condensation. The guide heat blocking sleeve 9 can reduce the gap between the valve stem assembly 2 and the flange heat dissipation assembly 10 and prevent too much cold air from being transmitted upward.

[0067] As shown in Figure 1 , Figure 3 and Figure 6 , in this embodiment, the valve stem assembly 2 is composed of an upper valve stem 21 and a main valve stem 22, and a T-shaped groove 212 is formed at the bottom of the upper valve stem 21, and a T-shaped block 221 is arranged at the top of the main valve stem 22 and is clamped and connected in the T-shaped groove 212.

[0068] The second sealing assembly group includes a valve stem sealing assembly 60 arranged between the upper valve stem 21 and the upper channel 41, and the valve stem sealing assembly 60 can be a combination of multiple sealing rings, which is relatively common and will not be described here.

[0069] As shown in Figure 1 , Figure 3 and Figure 6As shown, in the embodiment, the valve stem assembly displacement adjusting structure is that an outer connecting threaded section 211 is arranged on the upper valve stem 21, an inner connecting threaded section is arranged at the top end of the upper channel 41, a valve stem nut 20 with an inner threaded hole matched with the outer connecting threaded section is screwed on the outer connecting threaded section, the lower end of the valve stem nut 20 is outwardly folded to form a lower flange 201, after the push ball bearing 30 and the compression nut 40 are sleeved on the valve stem nut 20, the outer threaded section on the compression nut 40 is screwed with the inner connecting threaded section, the upper and lower positions of the valve stem nut 20 are limited, so that the valve stem nut 20 can only rotate but cannot move up and down, and the hand wheel 50 is fixedly installed on the valve stem nut 20 extending out of the top of the compression nut 40.

[0070] The valve disc assembly 3 is arranged with a self-tightening structure, and when the valve disc assembly 3 is blocked on the connecting port 17, the valve disc assembly 3 is pressed against the connecting port 17 with a certain pressure through the self-tightening structure.

[0071] In the embodiment, the self-tightening structure is that the valve disc assembly 3 is hinged to the bottom of the valve stem assembly 2 through the pin shaft 34, the top surface of the valve disc assembly 3 at the bottom surface of the valve stem assembly 2 is sequentially arranged from top to bottom with the first installation space 311, the second installation space 312 and the third installation space 313, the pressing block 33 penetrates through the second installation space 312 and the third installation space 313, the limiting protrusion 331 outwardly protruding and larger than the opening of the second installation space 312 is arranged on the top of the pressing block 33 extending above the second installation space 312, and the spring is sleeved on the pressing block at the second installation space 312.

[0072] In the embodiment, the spring preferably adopts a plurality of butterfly springs 32.

[0073] When the low-temperature stop valve is in the closed state, the spring has two effects, one is to give the valve disc assembly 3 a downward force to ensure that the valve disc assembly 3 and the connecting port 17 can be effectively sealed, and even if they are in a vibration working condition for a long time, they can still be well sealed, and the other is to give the valve stem assembly 2 an upward force, which finally acts on the outer connecting threaded section 211 of the upper valve stem 21 and the inner threaded hole of the valve stem nut 20, so that the threads of the outer connecting threaded section 211 of the upper valve stem 21 and the threads of the inner threaded hole of the valve stem nut 20 are engaged more tightly, to ensure that even if the low-temperature stop valve is in a vibration working condition for a long time, the valve stem nut 20 will not loosen, causing the valve stem assembly 2 to move up, and thus the valve cannot be tightly closed, greatly improving the sealing effect of the low-temperature stop valve in the closed state and improving the safe use performance of the low-temperature stop valve.

[0074] The above merely is the preferred embodiment of the present application, and is not any other form of limitation to the present application, and any modification or equivalent change according to the technical essence of the present application still belongs to the range required to be protected by the present application.

Claims

1. A cryogenic stop valve, comprising: The valve body assembly, valve stem assembly, valve flap assembly and valve cover; characterized in that: a first channel and a second channel are arranged in the lower part of the valve body assembly; the outer end of the first channel penetrates through the outer side wall of the valve body assembly, forming a first opening on the outer side wall of the valve body assembly; the outer end of the second channel penetrates through the outer side wall of the valve body assembly, forming a second opening on the outer side wall of the valve body assembly; a blocking part is arranged between the top of the inner end of the first channel and the bottom of the inner end of the second channel, a connecting port is arranged on the blocking part, and the first channel and the second channel are communicated through the connecting port; a main channel is vertically arranged in the valve body assembly, the top end of the main channel penetrates through the top end of the valve body assembly, and the bottom end of the main channel is communicated with the connecting port; The valve cover is sealingly connected to the top end of the valve body assembly, an upper channel is vertically arranged in the valve cover, the upper channel is communicated with the main channel, and the upper channel and the main channel are coaxial; The valve stem assembly is arranged in the main channel and the upper channel, a first sealing assembly group is arranged between the valve stem assembly and the main channel, and a second sealing assembly group is arranged between the valve stem assembly and the upper channel; The valve flap assembly is arranged at the bottom of the valve stem assembly, a valve stem assembly displacement adjusting structure is arranged in the upper channel to move the valve stem assembly upward or downward to a required position and maintain the valve stem assembly at the position; the valve stem assembly can be moved downward by the valve stem assembly displacement adjusting structure to block the valve flap assembly on the connecting port, so that the first channel and the second channel are blocked and not communicated; or the valve stem assembly can be moved upward by the valve stem assembly displacement adjusting structure to move the valve flap assembly away from the connecting port, so that the first channel and the second channel are communicated; A self-tightening structure is arranged on the valve flap assembly, and the valve flap assembly is pressed against the connecting port with a certain pressure by the self-tightening structure when the valve flap assembly is blocked on the connecting port.

2. A cryogenic stop valve according to claim 1, characterized in that: The self-tightening structure is that the valve flap assembly is hingedly connected to the bottom of the valve stem assembly by a pin shaft, a first installation space, a second installation space and a third installation space are sequentially arranged from top to bottom on the top surface of the valve flap assembly at the bottom surface of the valve stem assembly, a pressing block is arranged in the second installation space and the third installation space, a limiting protrusion is arranged on the top of the pressing block extending out of the second installation space, and the limiting protrusion is outwardly protruding and larger than the opening of the second installation space, and a spring is sleeved on the pressing block at the second installation space; when the valve flap assembly is blocked on the connecting port, the limiting protrusion is pressed against the bottom surface of the valve stem assembly under the elastic force of the spring, and the valve flap assembly is pressed against the connecting port.

3. A cryogenic stop valve according to claim 2, characterised in that: The spring is a plurality of butterfly springs.

4. A cryogenic stop valve according to claim 2, characterized in that: The bottom surface of the valve stem assembly is a downwardly protruding spherical curved surface, and the limiting protrusion is pressed against the spherical curved surface.

5. A cryogenic stop valve according to claim 1 or 2 or 3 or 4, characterised in that: The connecting port is sequentially composed of a conical channel with a trumpet-shaped opening upward and a round hole channel from top to bottom; The valve flap assembly comprises a valve flap body, a threaded connecting rod arranged at the bottom of the valve flap body, a plurality of downwardly protruding protruding points arranged on the bottom surface of the valve flap body, and a valve flap sealing member fixed by a locking nut after being sleeved on the threaded connecting rod, and each protruding point is pressed against the valve flap sealing member; when the valve flap assembly is pressed against the connecting port, the valve flap sealing member is sealingly contacted with the inner side wall of the conical channel.

6. A cryogenic stop valve according to claim 5, characterised in that: The outer side wall profile of the valve clack seal has a conical surface with a large upper diameter and a small lower diameter, and the conical surface of the valve clack seal is tightly attached to the inner side wall of the conical passage when the valve clack assembly is abutted against the connecting port.

7. A cryogenic stop valve according to claim 1, characterized in that: The first sealing assembly group comprises a guide liquid-separation assembly. The valve stem assembly is composed of a main valve stem and a connecting rod connected to the bottom of the main valve stem, and the valve clack assembly is arranged at the bottom of the connecting rod, and an upper segment external thread segment is arranged on the upper segment of the connecting rod. The guide liquid-separation assembly comprises a guide sleeve, and a sealing gasket mounting groove, an internal thread connecting hole, an elastic pad mounting groove and a lower through hole are sequentially arranged on the top surface of the guide sleeve from top to bottom; a sealing gasket is placed in the sealing gasket mounting groove, and an elastic pad is placed in the elastic pad mounting groove; after the guide sleeve is screwed on the upper segment external thread segment through the internal thread connecting hole, the guide sleeve and the bottom of the main valve stem are in sealing contact through the sealing gasket; a step is arranged on the connecting rod, the elastic pad is clamped in the step and the elastic pad mounting groove, and the elastic pad is abutted against the step and the elastic pad mounting groove, respectively; At least one guide ring mounting groove is formed on the outer circumferential side wall of the guide sleeve, and a guide ring is placed in each guide ring mounting groove, and each guide ring is in contact with the main passage, and a through groove for passing only liquefied gas is arranged on the outer side wall of each guide ring.

8. A cryogenic stop valve according to claim 1, characterized in that: A connecting piece mounting groove is formed downward on the top end of the main passage, and a connecting piece is placed in the connecting piece mounting groove, and the top of the connecting piece and the valve cover and the connecting piece and the connecting piece mounting groove are sealed by upper sealing gaskets; A heat insulation sleeve mounting groove and a lower passage for passing the valve stem assembly are sequentially formed downward on the top surface of the connecting piece, and the heat insulation sleeve is worn on the valve stem assembly and placed in the heat insulation sleeve mounting groove.

9. A cryogenic stop valve according to claim 8, characterised in that: The lower segment of the valve stem assembly has a hollow closed cavity; a bellows is sleeved on the valve stem assembly, the upper end of the bellows is fixedly connected to the bottom of the connecting piece, and the lower end of the bellows is connected to the side wall of the valve stem assembly above the closed cavity; A guide heat insulation sleeve is sleeved on the bellows and the valve stem assembly below the bellows; The valve body assembly comprises an external wrapping heat preservation layer and a jacket assembly.

10. A cryogenic stop valve according to claim 1, characterized in that: The valve stem assembly is composed of an upper valve stem and a main valve stem spliced together, a T-shaped groove is formed on the bottom of the upper valve stem, and a T-shaped block is arranged on the top of the main valve stem and embedded in the T-shaped groove; The second sealing assembly group comprises a valve stem sealing assembly arranged between the upper valve stem and the upper passage; The displacement adjustment structure of the valve stem assembly is that an external connecting thread segment is arranged on the upper valve stem, and an internal connecting thread segment is arranged at the top end of the upper passage; a valve stem nut with an internal thread hole matched with the external connecting thread segment is screwed on the external connecting thread segment, the lower end of the valve stem nut is outwardly folded to form a lower flange, and after a thrust ball bearing and a pressing nut are sleeved on the valve stem nut, the external thread segment on the pressing nut is screwed with the internal connecting thread segment to limit the position of the valve stem nut, so that the valve stem nut can only rotate and cannot move up and down; A hand wheel is fixedly installed on the valve stem nut protruding outward from the top of the pressing nut.

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