CN219452918U - Valve for conveying corrosive fluid - Google Patents

Abstract

The utility model discloses a valve for conveying corrosive fluid, which comprises a valve main body and a housing, wherein the valve main body is provided with an inlet flow passage, an outlet flow passage and a valve port, the valve port is used for communicating the inlet flow passage and the outlet flow passage, a valve shaft extending into the valve main body is arranged in the housing, a corrugated pipe valve core is arranged at the bottom of the valve, and the corrugated pipe valve core comprises: an annular mounting member; a flange in sealing engagement with an annular groove formed in the top of the valve body to confine fluid within the valve body; a bellows assembly including a plurality of axially extending bellows that axially extend or compress as the valve shaft moves axially; the valve core sealing part is formed at the bottom of the corrugated section group; the bottom end of the valve shaft is connected with a valve core sealing part, and the valve core sealing part can axially move along with the valve shaft to block or open the valve port. According to the utility model, the valve main body is subjected to axial displacement by means of the expansion and contraction deformation of the bellows group in the opening and closing process, the annular mounting piece can keep the shape unchanged basically, and the service life of the bellows valve core is prolonged.

Description

Valve for conveying corrosive fluid

Technical Field

The utility model belongs to the technical field of fluid control valves, and particularly relates to a valve for conveying corrosive fluid.

Background

In the semiconductor industry, diaphragm valves are commonly used to deliver highly corrosive liquids, and generally include an upper housing, a valve body having a flow passage therein for the flow of the corrosive liquid, a valve seat therein separating the flow passage upstream from the flow passage downstream, and a valve port above the valve seat; the valve assembly generally includes a fixed portion, a membrane portion, and a valve element, the valve being in a closed state when the valve element closes the valve seat, and corrosive liquid being prevented from passing through the valve port by the membrane portion when the valve is in an open state.

The patent number CN217898795U discloses a diaphragm valve for conveying corrosive fluid, which comprises a valve main body, a valve assembly, a diaphragm pressing plate and an exhaust runner, wherein an inlet runner, an outlet runner and a valve port are arranged in the valve main body, wherein the inlet runner and the outlet runner are used for allowing the corrosive fluid to flow through the valve main body, and the valve port is used for connecting the inlet runner and the outlet runner. The valve assembly comprises a valve core, a membrane part and a fixing part, wherein the membrane part is arranged along the circumferential direction of the valve core, the fixing part is arranged on the outer ring of the membrane part, the valve assembly is connected to the valve body in a sealing mode by the fixing part, the valve core axially reciprocates to realize the purpose of blocking or opening a valve port, and the membrane part deforms in the state switching process of the valve core.

However, the diaphragm type diaphragm of the above patent relies on the vertical deformation of the diaphragm portion to make the valve core sealing portion obtain axial displacement during the opening and closing process of the valve body, the fatigue failure is caused by long time turning of the start and stop points of the diaphragm portion, and the diaphragm portion is limited by the size, the vertical deformation distance of the diaphragm portion is small, namely, the axial displacement of the valve core sealing portion is small, the opening of the valve port is small, and the flow coefficient is low in the application of large-caliber valves.

Disclosure of Invention

In order to overcome the defects in the prior art, the utility model provides a valve for conveying corrosive fluid, wherein the axial displacement of a valve core sealing part is regulated and increased through a corrugated pipe, and the valve core sealing part does not need to be axially moved mainly by deformation of an annular mounting piece.

The utility model solves the technical problem that the technical scheme adopted by the utility model is a valve for conveying corrosive fluid, which comprises a valve main body and a housing arranged at the top of the valve main body, wherein the valve main body is provided with an inlet flow passage, an outlet flow passage and a valve port for fluid to flow through, the valve port is used for communicating the inlet flow passage and the outlet flow passage, a valve shaft capable of axially moving is arranged in the housing, the valve shaft extends into the valve main body, the bottom of the valve shaft is provided with a corrugated pipe valve core, and the corrugated pipe valve core comprises:

an annular mounting member;

a flange formed on the outer side of the annular mounting member and in sealing engagement with an annular groove formed in the top of the valve body to confine fluid within the valve body;

a bellows group formed inside the annular mounting member, including a plurality of axially extending bellows that axially expand or compress when the valve shaft axially moves;

the valve core sealing part is formed at the bottom of the corrugated section group;

the bottom end of the valve shaft penetrates through the annular mounting piece and the inner side of the corrugated joint group to be connected with the valve core sealing part, and the valve core sealing part can axially move along with the valve shaft to seal or open the valve port.

In the utility model, the axial displacement of the valve core sealing part is not required to be obtained mainly by the up-and-down deformation of the annular mounting piece, the annular mounting piece can keep unchanged shape, or the shape change is little or negligible, so that the service life of the valve core of the corrugated pipe is prolonged; the valve main body mainly relies on compression and stretching deformation of the corrugated joint groups to obtain axial displacement in the opening and closing process, the axial displacement of the valve core sealing part is obtained by accumulating the compression and stretching deformation of a plurality of corrugated joints, the axial displacement of the valve core sealing part can be increased by increasing the number of the corrugated joints, the use flexibility is high, the axial movable range of the valve shaft is large, and an ideal flow coefficient annular mounting piece can be obtained in a large-caliber valve.

Further, each of the bellows includes a straight portion and a curved portion, the curved portion and the straight portion smoothly transition, and the thickness of the curved portion is greater than the thickness of the straight portion.

When the corrugated joint is axially compressed or stretched to deform, the bending part is used as a part playing a main role in deformation, and the fatigue life of the corrugated joint can be prolonged by increasing the wall thickness of the bending part, so that the service life of the corrugated joint group is prolonged.

Further, the radial width of each corrugated section is a, the height of the gap between every two adjacent corrugated sections is b, and the value of a/b is in the range of 1.5-10.

Under the numerical range, the axial displacement of the corrugated joint can be increased under the same deformation degree, meanwhile, the outer groove can not be too deep, the flow velocity of fluid in the outer groove is prevented from being too small, the deposition and accumulation of particles caused by too deep groove depth when a solution containing particles (such as grinding fluid) is used are prevented, the effective axial stretching or compression of the corrugated joint is ensured, and the service life of the corrugated joint group is prolonged.

Further, an outer groove is formed between two adjacent bellows, and the depth of the outer groove is less than or equal to 10mm.

The depth of the outer groove is reasonably set, and the situation that particles in the corrosive fluid with the too large depth of the outer groove are deposited and accumulated in the depth of the outer groove and are not easy to flow out is reduced as much as possible.

Further, the top of the valve body is provided with pressing plates respectively connected with the valve body and the housing in a sealing mode, and the pressing plates are located right above the annular mounting piece and penetrated by the valve shaft.

So set up, the clamp plate forms the support at the back of annular mounting spare, when the large-traffic fluid passes through the valve port, great fluid pressure acts on the annular mounting spare openly, and the clamp plate supports the back of annular mounting spare to annular mounting spare is with pressure transmission on the clamp plate, improves the atress condition of annular mounting spare, reduces the pressure-bearing and the reliability requirement to annular mounting spare, and extension annular mounting spare's life.

Further, an outer edge of one of the platen and the annular mount is provided with an annular protrusion that contact presses an outer edge of the other of the platen and the annular mount.

The arrangement is such that at least part of the annular projection corresponds up and down to the flange, whereby the axial force exerted by the flange during installation is increased, a powerful downward pressing action is formed on the annular mounting and flange, whereby the flange fits into the annular groove with interference to form a sealing fit.

Further, a sleeve is sleeved on the outer wall of the valve shaft and right above the valve core sealing part, and the sleeve separates the bellows group and the valve shaft in the axial direction.

The telescopic material of reasonable setting makes the friction between sleeve and the bellows group soft relatively, avoids the wearing and tearing that bellows group and valve shaft direct contact lead to, simultaneously, the sleeve has still formed radial spacing effect to the bellows group, avoids the crooked part of bellows to stretch out and draw back at radial expansion many times back, guarantees the effective axial expansion volume of bellows group.

Further, an air inlet and an air inlet channel communicated with the air inlet are formed in the housing, a piston and an elastic piece propped against the piston are arranged in the housing, the piston is in sliding sealing fit with the inner wall of the housing, the piston is connected with the top end of the valve shaft, and the lower area of the piston is communicated with the air inlet channel.

Above-mentioned structure sets up for external gas can get into the air inlet channel through the air inlet, and then drive piston upward movement drives valve shaft upward movement, thereby can realize opening of valve port through pneumatic means, and whole cooperation simple structure is effective.

Further, an inclined plane is formed on the inner side of the valve port, and the outer wall of the valve core sealing part is provided with a sealing surface which can be in contact sealing fit with the inclined plane.

The valve port and the valve core sealing part are sealed by the inclined plane, so that even if the valve core sealing part has small deflection in the up-and-down movement in consideration of the manufacturing precision and the assembly precision of parts, good sealing effect can be ensured between the sealing surface and the inclined plane, and the risk of micro leakage is avoided; the sealing surface can be designed into an outwards-protruding arc sealing surface, and the valve core sealing part and the valve port inclined surface have a guiding self-centering function in the closing process, so that the sealing surface circumference is ensured to be effectively contacted and sealed.

Further, the valve body and the housing are in locking connection through a clamp, and the clamp comprises a radial inner flange and an axial side wall which can be in threaded connection with the valve body; the inner wall of the housing is provided with a step compression ring which can be propped against the top surface of the pressing plate, and the outer wall of the housing is provided with an annular check ring which can be propped against the radial inner flange.

So set up, make things convenient for the assembly connection between housing and the valve main part, accomplish the assembly back, step clamping ring downwardly extrusion clamp plate, the valve main part upwards supports the clamp plate, and radial inward flange is located annular retainer ring top, and when axial lateral wall and valve main part threaded connection, radial inward flange is the annular retaining ring of holding downwards, and simultaneously, step clamping ring is the clamp plate of holding downwards pressure, and whole assembly structure is simple and firm again.

Further, a support member is provided below the annular mounting member, in contact with the lower surface of the annular mounting member, and is connected to the top inner side wall of the valve body.

The support piece forms effectual bearing supporting role to annular mounting piece, prevents that annular mounting piece from producing deformation under the downwardly stretching atress effect of bellows group, and support piece links to each other with the top inner wall of valve main part, sets up simple structure, connects firmly.

The beneficial effects of the utility model are as follows: the valve main body mainly relies on compression and stretching deformation of the corrugated joint group to obtain axial displacement in the opening and closing processes, the annular mounting piece can keep unchanged shape, or the shape change is little or negligible, so that the service life of the corrugated pipe valve core is prolonged; in addition, the axial displacement of the valve core sealing part is obtained by accumulating compression and stretching deformation of a plurality of bellows, the axial displacement of the valve core sealing part can be increased by increasing the number of the bellows, the use flexibility is high, the axial movable range of the valve shaft is large, and an ideal flow coefficient can be obtained in a large-caliber valve; the annular mounting part corrugated section group axially displaces and increases under the same deformation degree, so that the fluid ensures larger flow velocity and local accumulation is not caused; the pressure plate forms a support on the back surface of the annular mounting piece, fluid pressure acts on the front surface of the annular mounting piece, and the pressure plate supports the back surface of the annular mounting piece, so that the annular mounting piece transmits pressure on the pressure plate, the pressure bearing and reliability requirements on the annular mounting piece are reduced, and the service life of the annular mounting piece is prolonged; the sleeve not only avoids the direct contact between the corrugated joint group and the valve shaft, but also avoids radial expansion of the bending part of the corrugated joint after multiple expansion and contraction; the valve port and the valve core sealing part are sealed by inclined planes, so that the risk of micro leakage is avoided.

Drawings

Fig. 1 is a schematic perspective view of a valve according to the present utility model.

Fig. 2 is a schematic perspective view of a valve according to the present utility model.

Fig. 3 is a schematic top view of a valve according to the present utility model.

Fig. 4 is a cross-sectional view A-A of fig. 3, with the valve in a closed position.

Fig. 5 is a schematic cross-sectional view of the valve according to the present utility model, and the valve is in a closed state.

Fig. 6 is a cross-sectional view A-A of fig. 3, with the valve in an open state.

Fig. 7 is a schematic cross-sectional structure of the valve according to the present utility model, and the valve is in an open state.

Fig. 8 is a front view of the bellows valve core provided by the utility model.

Fig. 9 is a cross-sectional view of a bellows valve core provided by the utility model.

Fig. 10 is a cross-sectional view of a single bellows provided by the present utility model.

Wherein 1-valve body, 11-inlet flow passage, 12-outlet flow passage, 13-valve port, 131-inclined surface, 14-annular groove, 15-inlet, 16-inlet passage, 17-slot, 2-housing, 21-valve shaft, 22-pressure plate, 221-annular protrusion, 23-piston, 231-pilot stem, 24-elastic member, 25-stepped pressure ring, 26-annular retainer ring, 27-insert, 3-bellows spool, 31-annular mount, 32-flange, 33-bellows group, 331-bellows, 3311-straight portion, 3312-bent portion, 3313-bent portion, 332-outer groove, 34-spool seal, 341-sealing surface, 35-sleeve, 36-support, 4-clip, 41-radially inner flange, 42-axial sidewall.

Detailed Description

In order to make the present utility model better understood by those skilled in the art, the following description of the technical solutions of the present utility model will be made in detail, but not all embodiments of the present utility model are apparent to some embodiments of the present utility model. All other embodiments, which can be made by those skilled in the art based on the embodiments of the present utility model without making any inventive effort, shall fall within the scope of the present utility model.

As shown in fig. 1 to 4, a valve for transporting corrosive fluid includes a valve body 1, and a housing 2 mounted on top of the valve body 1, the valve body 1 having an inlet flow passage 11 through which fluid flows, an outlet flow passage 12, and a valve port 13, the valve port 13 being for communicating the inlet flow passage 11 and the outlet flow passage 12, a valve shaft 21 being axially movable in the housing 2, wherein the axial direction refers to the up-down direction shown in fig. 4. The valve shaft 21 extends downward into the valve body 1, and the bottom of the valve shaft 21 is provided with a bellows spool 3.

As shown in fig. 8 and 9, the bellows spool 3 includes an annular mount 31, a flange 32 formed outside the annular mount 31, a bellows group 33 formed inside the annular mount 31, and a spool sealing portion 34 formed at the bottom of the bellows group 33. The top of the valve body 1 is provided with an annular groove 14, and the flange 32 is in interference fit with the annular groove 14 to seal and mount the annular mounting piece 31 on the top of the valve body 1, so that the fluid is limited in the valve body 1, and the fluid is prevented from flowing in the direction of the housing 2.

The bellows group 33 includes a plurality of axially extending bellows 331, and the bottom end of the valve shaft 21 is connected to the spool sealing portion 34 after passing through the annular mounting member 31 and the inside of the bellows group 33, and when the valve shaft 21 moves axially, the spool sealing portion 34 moves axially along with the valve shaft 21, thereby blocking or opening the valve port 13, and at the same time, the plurality of bellows 331 extend or compress axially.

The valve body 1 is opened and closed, the valve core sealing part 34 obtains axial displacement by means of compression and stretching deformation of the bellows group 33, the axial displacement of the valve core sealing part 34 is obtained by accumulating compression and stretching deformation of the bellows 331, the number of the bellows 331 is increased, the axial displacement of the valve core sealing part 34 can be increased, and a desired flow coefficient can be obtained in a large-caliber valve. At the same time, the annular mounting member 31 can be kept substantially unchanged in shape, or the annular mounting member 31 has little or negligible change in shape, and less stress is generated, compared with the prior art structure, thereby prolonging the service life of the bellows core 3.

Specifically, as shown in fig. 10, the single bellows 331 has a U-shape or C-shape with an opening facing outward or an opening facing inward, where outward means toward the outside of the ring-shaped mounting member 31, and inward means toward the inside of the bellows group 33. Accordingly, the bellows 331 includes a flat portion 3311 and a curved portion 3312, the curved portion 3311 and the flat portion 3311 are smoothly transited, and the thickness of the curved portion 3312 is greater than that of the flat portion 3311, so that the curved portion 3311 serves as a main deformation region when the bellows 331 is axially compressed or stretched, which serves as a main portion when deformed, and increasing the wall thickness of the curved portion 3311 can improve the fatigue life thereof. In the present embodiment, the thickness of the bent portion 3312 is preferably 0.8mm, i.e., f=0.8 mm in fig. 9, and the thickness of the flat portion 3311 is preferably 0.6mm. It should be noted that, in studying the deformation of the flat portion 3311 and the curved portion 3311, not only the thickness thereof but also the shape and position thereof are considered, as shown in fig. 9, during the stretching of the bellows group 33, mainly the curved portion 3312 is stretched and deformed so that the opening of the single bellows 331 is enlarged, and the flat portion 3311 is also stretched and inclined.

More specifically, referring to fig. 9, where the radial width of a single bellows 331 is a, the gap height between two adjacent bellows is b, that is, the spacing between the flat portions 3311 of the adjacent bellows 331 is b, the value of a/b is in the range of 1.5 to 10. Further, the radial width a may be 2.8-4.6mm, preferably a=3.7 mm, and the pitch b may be 0.8-1.6mm, preferably b=1.2 mm. An outer groove 332 is formed between two adjacent bellows 331, the depth of the outer groove 332 is 10mm or less, i.e. c is 10mm or less in fig. 8, the width of the outer groove 332 is preferably 1.2mm, and the width of the outer groove 332 is the interval b. Under the above numerical range, the axial displacement of the bellows 331 can be increased under the same deformation degree, and at the same time, the outer groove 332 is prevented from being too large, the fluid flow rate of the fluid in the outer groove 332 is prevented from being too small, the deposition and accumulation of particles caused by too large groove depth when the solution (such as grinding fluid) containing particles is used, the effective axial stretching or compression of the bellows 331 is ensured, and the service life of the bellows group 33 is prolonged. In this embodiment, the bellows group 33 and the ring-shaped mounting member 31 are manufactured by machining or turning, and the formed bellows 331 are integrally provided, and the bellows 331 and the ring-shaped mounting member 31 are integrally connected, wherein the bellows group 33 is composed of a plurality of continuous bellows 331, and of course, in other embodiments, the bellows group 33 may be composed of discontinuous bellows 331, and the discontinuous portion is an elastic structure with other shapes, which is not particularly limited.

It should be further noted that, as shown in fig. 10, the single bellows 331 further includes a warp portion 3313 located at an end of the flat portion 3311, the two bellows 331 are smoothly transited by the warp portion 3313, the uppermost bellows 331 is integrally connected to the lower surface of the ring-shaped mount 31 by the warp portion 3313, the warp portion 3313 integrally connected to the ring-shaped mount 31 is deformed to stretch and compress only a substantially half (which may be made substantially vertical) of the warp portion 3313 integrally connected to the ring-shaped mount 31 during stretching or compressing, and the other substantially half (which may be made curved) of the warp portion 3313 is not deformed substantially, so that the warp portion 3313 of the uppermost bellows 331 integrally connected to the ring-shaped mount 31 is not easily broken during repeated stretching and compressing operations. Further, the uppermost warp portion 3313 for integrally connecting the bellows 331 with the ring mount 31 and the warp portion 3313 for smooth transition between the bellows 331 may be made the same or different.

In order to facilitate the sealing installation between the bellows valve core 3 and the valve body 1, the top of the valve body 1 is provided with a pressure plate 22, which pressure plate 22 is in sealing connection with the valve body 1 and the housing 2, respectively, by means of peripheral seals. The pressure plate 22 is located directly above the annular mount 31 and is penetrated by the valve shaft 21. The outer edge of one of the pressing plate 22 and the annular mount 31 is provided with an annular protrusion 221, and the annular protrusion 221 contacts the outer edge of the other of the pressing plate 22 and the annular mount 31. In this embodiment, the annular protrusion 221 is disposed on the outer edge of the lower surface of the pressing plate 22, and at least partially corresponds to the flange 32 up and down after the assembly is completed, so as to form a powerful downward pressing action on the annular mounting member 31 and the flange 32, thereby ensuring that the flange 32 is assembled into the annular groove 14 in an interference sealing manner.

In this embodiment, the annular mounting member 31 is made of a material having a small elastic modulus, and the deformation amount thereof is small, and the axial height of the annular mounting member 31 is 0.4mm or less, that is, d is 0.4mm or less in fig. 4. In the presence of the annular protruding portion 221, under the practical application condition or after the installation is completed, in the process that the annular protruding portion 221 presses the flange 32 into the annular groove 14, the edge of the upper surface of the annular mounting piece 31 is pressed downwards to deform due to concentrated axial stress, the annular protruding portion 221 is also downwards concavely filled in the deformation area, the upper surface of the annular mounting piece 31 is also in direct contact with the lower surface of the pressing plate 22, and therefore the upper surface of the annular mounting piece 31 and the lower surface of the pressing plate 22 are basically abutted, the position of the annular mounting piece 31 can be kept in the horizontal direction in the opening and closing process of the valve main body 1, the shape of the annular mounting piece 31 is kept to be free from deformation or the deformation is tiny, the annular mounting piece 31 is not singly subjected to the fluid back pressure by virtue of the pressing plate 22, and the service life of the annular mounting piece 31 is prolonged.

In order to more effectively ensure that the annular mounting piece 31 cannot deform after long-time use, the service life of the annular mounting piece 31 is prolonged, an annular supporting piece 36 is arranged below the annular mounting piece 31, as shown in fig. 4, the upper end face of the supporting piece 36 is contacted with the lower surface of the annular mounting piece 31, the side face of the supporting piece 36 is fixedly connected with the inner side wall of the top of the valve main body 1, the shape of the supporting piece 36 is not limited, and therefore the supporting piece 36 is firmly connected, and an effective bearing supporting effect can be formed on the annular mounting piece 31. In order to avoid wear caused by contact of the bellows group 33 with the valve shaft 21, a sleeve 35 is fitted over the outer wall of the valve shaft 21 directly above the valve element seal 34, the sleeve 35 separating the bellows group 33 from the valve shaft 21 in the axial direction. In the present embodiment, the sleeve 35 is made of PFA material, the bellows group 33 is made of PTFE material, and friction between the bellows 331 and the valve shaft 21 is relatively gentle, avoiding large friction between the two. At the same time, the sleeve 35 also forms a radial limit function on the bellows group 33, so that the bending part 3312 of the bellows 331 is prevented from expanding in the radial direction after multiple times of expansion, and the effective axial expansion amount of the bellows group 33 is ensured.

The valve provided in this embodiment is a pneumatic driving structure, an air inlet 15 and an air inlet channel 16 communicated with the air inlet 15 are arranged on the housing 2, a piston 23 and an elastic piece 24 propped against the piston 23 are arranged in the housing 2, the other end of the elastic piece 24 is propped against the inner top surface of the housing 2, the outer wall of the piston 23 is in sliding sealing fit with the inner wall of the housing 2, the bottom of the piston 23 is connected with the top end of the valve shaft 21, in this embodiment, the two are in threaded connection, and the lower area of the piston 23 is communicated with the air inlet channel 16. Furthermore, in other embodiments the valve is provided as manual, by which the valve shaft is driven in axial motion.

The bottom end of the valve shaft 21 passes through the pressing plate 22, the annular mounting piece 31 and the inner side of the bellows group 33 in sequence, and is assembled and connected with the valve core sealing part 34 in a threaded connection mode. An inclined surface 131 is formed on the inner side of the valve port 13, and a sealing surface 341 is formed on the outer wall of the valve element sealing portion 34, and the sealing surface 341 is in contact sealing fit with the inclined surface 131. In other words, the valve port 13 and the valve element sealing portion 34 are sealed by inclined planes, so that even if the valve element sealing portion 34 has a small deflection in moving up and down in consideration of the manufacturing precision and the assembly precision of the components, the sealing surface 341 and the inclined plane 131 can ensure a good sealing effect, and the risk of micro leakage is avoided. In order to further ensure the sealing effect, in this embodiment, the sealing surface 341 is an arc sealing surface protruding outwards, and the valve element sealing portion 34 has a guiding self-centering function with the inclined surface 131 of the valve port 13 during closing, so as to ensure circumferential contact of the sealing surface 341.

Further, in order to facilitate the assembly connection between the casing 2 and the valve body 1, the valve body 1 and the casing 2 are in locking connection by a clip 4, the clip 4 comprises a radial inner flange 41 and an axial side wall 42 which can be in threaded connection with the valve body 1, the radial inner flange 41 and the axial side wall 42 are of an integral structure, and threads are arranged on the inner surface of the axial side wall 42. The inner wall of the housing 2 is formed with a stepped pressure ring 25 which can be brought into abutment with the top surface of the pressure plate 22, and the outer wall of the housing 2 is formed with an annular collar 26 which can be brought into abutment with the radially inner flange 41. After the assembly, the step pressing ring 25 presses the pressing plate 22 downwards, the valve body 1 supports the pressing plate 22 upwards, the radial inner flange 41 is located above the annular retainer ring 26, the outer wall of the valve body 1 is provided with external threads, and when the axial side wall 42 is in threaded connection with the valve body 1, the radial inner flange 41 presses the annular retainer ring 26 downwards, and meanwhile, the step pressing ring 25 presses the pressing plate 22 downwards. In order that the housing 2 and the valve main body 1 cannot generate radial deflection during assembly, the bottom of the housing 2 is provided with the insert block 27, the upper end of the valve main body 1 is provided with the slot 17, the insert block 27 can be axially downwards inserted into the slot 17, and the valve main body is matched with the assembly structure, so that the whole structure is simple and stable, and the installation process is simple and convenient.

The operation of the present utility model is that in this embodiment the valve is a normally closed valve, i.e. the initial state of the valve is the sealing contact of the valve core sealing part 34 and the valve port 13. When the valve needs to be opened, as shown in fig. 6 and 7, gas flows through the gas inlet 15 and the gas flows to the area below the piston 23 through the gas inlet channel 16, so that the piston 23 is pushed to move upwards axially against the resistance of the elastic piece 24, the valve shaft 21 is driven to move upwards axially, the bellows group 33 is compressed, the sealing surface 341 of the valve core sealing part 34 is separated from the inclined surface 131, the valve port 13 is opened, and the inlet flow channel 11 and the outlet flow channel 12 are communicated. When the valve needs to be closed, as shown in fig. 4 and 5, at this time, the elastic member 24 extends downward, so that the piston 23 presses the valve shaft 21 downward, the valve shaft 21 moves axially downward, the bellows group 33 is driven to extend, the sealing surface 341 of the valve core sealing portion 34 is firmly abutted against the inclined surface 131 of the valve port 13, the valve port 13 is closed, and the inlet flow passage 11 and the outlet flow passage 12 are blocked.

In order to visually indicate whether the valve port 13 is in a closed or open state, an indication rod 231 is provided at the upper end of the piston 23, the indication rod 231 is movably penetrated through the top of the housing 2 and is penetrated to the outside, and the state of the valve port 13 is determined by the axial length of the indication rod 231 extending out of the housing 2.

The foregoing detailed description is provided to illustrate the present utility model and not to limit the utility model, and any modifications and changes made to the present utility model within the spirit of the present utility model and the scope of the appended claims fall within the scope of the present utility model.

Claims (11)

1. A valve for delivering corrosive fluids, comprising a valve body and a housing mounted on top of the valve body, the valve body having an inlet flow passage through which the fluid flows, an outlet flow passage, and a valve port for communicating the inlet flow passage with the outlet flow passage, an axially movable valve shaft being provided in the housing, the valve shaft extending into the valve body, characterized in that a bellows valve core is provided at the bottom of the valve shaft, the bellows valve core comprising:

an annular mounting member;

a flange formed on the outer side of the annular mounting member and in sealing engagement with an annular groove formed in the top of the valve body to confine fluid within the valve body;

a bellows group formed inside the annular mounting member, including a plurality of axially extending bellows that axially expand or compress when the valve shaft axially moves;

the valve core sealing part is formed at the bottom of the corrugated section group;

the bottom end of the valve shaft penetrates through the annular mounting piece and the inner side of the corrugated joint group to be connected with the valve core sealing part, and the valve core sealing part can axially move along with the valve shaft to seal or open the valve port.

2. The valve for delivering a corrosive fluid of claim 1, wherein: the single corrugated section comprises a straight portion and a bending portion, wherein the bending portion and the straight portion are in smooth transition, and the thickness of the bending portion is larger than that of the straight portion.

3. The valve for delivering corrosive fluids according to claim 1 or 2, characterized in that: the radial width of each corrugated section is a, the height of the gap between every two adjacent corrugated sections is b, and the value of a/b is in the range of 1.5-10.

4. The valve for delivering a corrosive fluid of claim 1, wherein: an outer groove is formed between two adjacent corrugated sections, and the depth of the outer groove is less than or equal to 10mm.

5. The valve for delivering a corrosive fluid of claim 1, wherein: the top of the valve main body is provided with pressing plates which are respectively connected with the valve main body and the housing in a sealing mode, and the pressing plates are located right above the annular mounting piece and penetrated by the valve shaft.

6. The valve for delivering a corrosive fluid of claim 5, wherein: an outer edge of one of the platen and the annular mount is provided with an annular protrusion that contact presses an outer edge of the other of the platen and the annular mount.

7. The valve for delivering a corrosive fluid of claim 1, wherein: the outer wall of the valve shaft and positioned right above the valve core sealing part are sleeved with a sleeve, and the sleeve axially separates the corrugated joint group from the valve shaft.

8. The valve for delivering a corrosive fluid of claim 1, wherein: the valve is characterized in that an air inlet and an air inlet channel communicated with the air inlet are formed in the housing, a piston and an elastic piece propped against the piston are arranged in the housing, the piston is in sliding sealing fit with the inner wall of the housing, the piston is connected with the top end of the valve shaft, and the lower area of the piston is communicated with the air inlet channel.

9. The valve for delivering a corrosive fluid of claim 1, wherein: an inclined plane is formed on the inner side of the valve port, and the outer wall of the valve core sealing part is provided with a sealing surface which can be in contact sealing fit with the inclined plane.

10. The valve for delivering a corrosive fluid of claim 1, wherein: the valve main body is in locking connection with the housing through a clamp, and the clamp comprises a radial inner flange and an axial side wall which can be in threaded connection with the valve main body; the inner wall of the housing is provided with a step compression ring which can be propped against the top surface of the pressing plate, and the outer wall of the housing is provided with an annular check ring which can be propped against the radial inner flange.

11. The valve for delivering a corrosive fluid of claim 1, wherein: and a supporting piece is arranged below the annular mounting piece, is contacted with the lower surface of the annular mounting piece and is connected with the top inner side wall of the valve main body.