CN218913820U - Diaphragm valve - Google Patents

Abstract

The utility model discloses a diaphragm valve, which comprises a valve main body, a diaphragm valve and a valve seat, 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, and the valve port is connected with the inlet flow passage and the outlet flow passage; the valve assembly comprises a valve core, a membrane part and a sealing part, wherein the membrane part is arranged along the circumferential direction of the valve core, the sealing part is arranged on the outer ring of the membrane part, and the valve core axially reciprocates to block or open the valve port; an upper housing provided at an axial upper end of the valve main body; the bottom of the upper shell is provided with a flexible piece, the valve body is provided with an annular bulge, and the flexible piece and the annular bulge clamp the sealing part in opposite directions so as to form sealing fit between the valve assembly and the valve body. In the utility model, the flexible piece and the annular bulge clamp the sealing part in opposite directions from two surfaces of the thickness direction of the sealing part respectively, so that particulate matters are prevented from entering the flow channel to pollute the conveyed fluid; the matching precision requirement of the sealing part and the valve assembly is reduced; under the deformation effect of the flexible piece, the effective contact sealing area of the sealing part and the annular bulge is large, and the sealing effect is good.

Description

Diaphragm valve

Technical Field

The utility model belongs to the technical field of filter equipment, and particularly relates to a diaphragm valve.

Background

In the semiconductor industry, diaphragm valves are commonly used to deliver highly corrosive liquids such as highly pure wet chemicals, and these diaphragm valves consist of a valve body having an annular socket disposed around a valve port therein, a valve assembly having a seal portion outside thereof that is interference fit with the annular socket to form a seal, and an actuating assembly, etc.

In the prior art, the sealing part is designed to be approximately perpendicular to the membrane part, as shown in the patent of publication No. CN217328488U, the annular slot comprises a first slot wall and a second slot wall which are opposite, the slot width is gradually reduced from the top to the slot bottom, the sealing part is provided with a first surface and a second surface, at least part of the first surface can form extrusion sealing with the first slot wall, and at least part of the second surface can form extrusion sealing with the second slot wall.

The structure has high requirement on the matching precision between the bottom end face of the sealing part and the bottom wall of the annular groove, the bottom end face of the sealing part and the bottom surface of the annular groove incline in the manufacturing process or the valve component inclines in the mounting process, so that liquid leakage is caused, if the two sides of the periphery of the sealing part are in interference with the side wall of the annular groove, the sealing part is difficult to mount into the annular groove, and extrusion and friction acting forces between the sealing part and the annular groove are overlarge during mounting, on one hand, the peripheral sealing flange can be possibly worn, on the other hand, the sealing part and the annular groove inevitably form particles due to extrusion and friction, and the particles fall into a downstream flow channel on the radial inner side of the annular slot to pollute high-purity wet chemicals; if the seal is clearance fit, the seal portion cannot be supported by the annular socket during compression, and thus the axial plastic deformation affects the sealing performance.

Disclosure of Invention

In order to overcome the defects of the prior art, the utility model provides the diaphragm valve which is effective in sealing, low in processing precision requirement and free from pollution to fluid.

The technical scheme adopted for solving the technical problems is as follows: a diaphragm valve, comprising,

a valve body having an inlet flow passage for fluid flow therethrough, an outlet flow passage, and a valve port connecting the inlet flow passage and the outlet flow passage;

the valve assembly comprises a valve core, a membrane part and a sealing part, wherein the membrane part is arranged along the circumferential direction of the valve core, and the sealing part is arranged on the outer ring of the membrane part;

an upper housing provided at an axial upper end of the valve main body;

the bottom of the upper shell is provided with a flexible piece, the valve main body is provided with an annular bulge, and the flexible piece and the annular bulge clamp the sealing part in opposite directions to form sealing fit of the valve assembly and the valve main body.

According to the diaphragm valve, the flexible piece and the annular bulge of the diaphragm valve clamp the sealing part in opposite directions from the two surfaces of the sealing part in the thickness direction, so that the problem that particles are generated due to mutual extrusion friction between the sealing part and the annular groove due to the fact that the sealing part is clamped into the annular groove of the valve main body in the traditional structure is effectively avoided, and the particles are prevented from entering the flow channel to pollute the conveyed fluid; meanwhile, the matching precision requirement on the sealing part and the valve assembly is reduced, and the processing and the installation are more convenient; under the deformation effect of the flexible piece, the contact sealing surface between the flexible piece and the sealing part is increased, so that the whole sealing part is subjected to curvature deformation along the surface of the annular bulge, the effective contact sealing area of the sealing part, the flexible piece and the annular bulge is ensured, and the sealing effect is better.

Further, the sealing part is integrally formed from the outer ring of the membrane part in an extending manner, and the included angle between the sealing part and the membrane part is 150-180 degrees.

The sealing part and the membrane part are integrally formed, so that the processing is convenient, and the connection strength of the sealing part and the membrane part is high; the sealing part and the membrane part form an included angle of 150-180 degrees, so that the membrane part is obliquely arranged, the membrane part is ensured to have enough deformation, and the service life of the membrane part is prolonged.

Further, a groove is formed radially outward of the annular projection to accommodate the tip of the seal portion.

The arrangement of the groove body enables the tail end of the sealing part to be provided with an accommodating space, the sealing part can be continuously bent downwards after being attached to the convex peak and the second side surface, the tail end of the sealing part is prevented from interfering with the inner wall of the valve main body, and the contact area between the sealing part and the annular protrusion is increased.

Further, a pressing ring is arranged at the bottom of the upper shell, is positioned at the radial outer side of the flexible piece, and presses the tail end of the sealing part towards the direction of the groove body.

If the deformation of the sealing part is mainly provided by the flexible part, the flexible part is caused to generate a large amount of deformation, but the sealing part and the second side surface are not formed to be effectively sealed, the sealing part can be pressed downwards by the arrangement of the pressing ring, the pressing ring is matched with the flexible part, the sealing part is firstly enabled to generate larger deformation, the acting force is applied to the sealing part through the flexible part, the sealing part is enabled to generate smaller deformation, the sealing part is enabled to be effectively attached to the annular convex second side surface, the sealing part and the second side surface are enabled to have enough contact areas, and effective sealing clamping of the sealing part by the flexible part and the second side surface is further guaranteed.

Further, the end of the sealing portion forms a gap with the inner wall of the valve body.

The setting in clearance avoids pressing down the terminal circumstances of sealing part at the clamping ring, forms the interference between the inner wall of sealing part terminal and valve main part, avoids the valve main part inner wall to form radial inwards extrusion force to the sealing part to make the sealing part form the crimping of certain degree, even to radial inboard removal, avoid seal area's reduction, guarantee the effective contact seal between sealing part and the annular bulge.

Further, the annular protrusion comprises a convex peak, a first side surface positioned on the inner side of the convex peak, and a second side surface positioned on the outer side of the convex peak, and the flexible piece and the second side surface clamp the sealing part in opposite directions.

The center of the flexible piece is arranged above the second side surface on the radial outer side, so that the flexible piece and the second side surface clamp the sealing part in opposite directions, namely, the sealing part is sealed outside the convex peak, the sealing part cannot occupy the space of the membrane part, the angle deformation of the sealing part cannot be too large, and the deformation quantity of the membrane part is ensured on the premise of ensuring the service life of the membrane part.

Further, the first side surface, the convex peak and the second side surface are all arc surfaces and are in smooth transition.

The first side surface, the convex peak and the second side surface are arc surfaces in smooth transition, so that the sealing part can be tightly attached to the sealing part, the sealing contact area is large, and finally, a good sealing effect is achieved.

Further, the radial width of the sealing part is L1, and the cambered surface length of the second side surface is L2; the second side surface forms a side wall of the groove body, and then L2 is more than or equal to L1; the side wall of the groove body comprises a second side surface and a wall surface, wherein the height of the wall surface is L3, and then L2+L3 is more than or equal to L1.

Above-mentioned numerical value sets for, guarantees that sealing portion is pressed down when holding by the clamping ring, and the end of sealing portion can not lead to contacting the bottom surface of cell body because of its radial length is too big, and then leads to the cell body bottom surface to form the extrusion force to sealing portion, forms the crimping of sealing portion certain degree, and ascending skew even guarantees the effective laminating between sealing portion and the second side surface, guarantees the effective seal between sealing portion and the annular bulge then.

Further, the bottom of the upper shell is provided with a mounting groove, and the outer ring of the flexible piece is propped against the outer side wall of the mounting groove.

The setting of mounting groove is convenient for the assembly of flexible piece, offsets the outer lane of flexible piece with the lateral wall of mounting groove for the outer end of flexible piece can flow downwards and seal portion offsets better.

Further, the inner ring of the flexible piece is located above the first side surface, and forms a gap with the inner side wall of the mounting groove.

The gap is formed between the inner end of the flexible piece and the mounting groove, so that the inner end of the flexible piece can deform towards the direction of the gap, the strength of the inner end of the flexible piece or the pressure applied to the inner end of the flexible piece is reduced, and the inner end of the flexible piece can better provide flexible support for the movement of the membrane part.

Further, the thickness of the sealing part is 0.3-0.7mm, the thickness of the root part of the membrane part connected with the valve core is 0.4-0.8mm, the thickness of the root part is larger than that of the sealing part, and the thickness of the membrane part is gradually changed between the sealing part and the root part; or the sealing part and the film part are horizontally and integrally connected, and the thickness of the sealing part and the film part is 0.3-0.7mm.

If the thickness of the sealing part is too large, the sealing part cannot form effective sealing fit with the annular bulge under the action of the flexible piece, and if the thickness of the sealing part is too small, the contact area of the sealing part and the annular bulge is too small, the strength is insufficient, and the service life is too short; the thickness of the root part is larger than that of the sealing part, so that the stable connection between the sealing part and the valve core is ensured; the gradual change arrangement prevents abrupt change of thickness between the membrane part and the sealing part, prevents stress concentration of the membrane part on the sealing part, ensures the strength of the membrane part and prolongs the service life of the membrane part; the sealing part is relatively thinner, the strength is lower, the deformation is more easy to occur, the membrane part is relatively thicker, and corrosive gas is not easy to penetrate through the membrane part from intermolecular gaps in the membrane part to corrode parts in the upper shell.

Further, the valve assembly is provided with a step part above the membrane part, and the bottom of the upper shell is provided with a blocking part which can prop against the step part so as to limit the axial movable stroke of the valve assembly.

When the valve assembly moves upwards to the blocking part to be abutted against the step part, the valve assembly stops moving, excessive upward movement of the valve assembly is effectively avoided, deformation of the membrane part caused by excessive stretching is avoided, the service life of the membrane part is prolonged, the membrane part is prevented from being separated from the flexible part and the sealing clamping of the annular protrusion, and effective sealing fit of the valve assembly and the valve main body is ensured.

The beneficial effects of the utility model are as follows: the flexible piece and the annular bulge of the diaphragm valve clamp the sealing part in opposite directions from two surfaces of the thickness direction of the sealing part respectively, so that particles are prevented from entering the flow channel to pollute the conveyed fluid; the matching precision requirement on the sealing part and the valve assembly is reduced, and the processing and the installation are more convenient; under the deformation action of the flexible piece, the contact sealing surface between the flexible piece and the sealing part is increased, the effective contact sealing area of the sealing part and the annular bulge is large, and the sealing effect is better; the sealing part and the membrane part form an included angle of 150-180 degrees, so that the membrane part is obliquely arranged, the membrane part is ensured to have enough deformation quantity, and the service life of the membrane part is prolonged; the arrangement of the groove body enables the tail end of the sealing part to be provided with an accommodating space, so that interference between the tail end of the sealing part and the inner wall of the valve main body is avoided, and effective contact sealing between the sealing part and the annular protrusion is ensured.

Drawings

Fig. 1 is a perspective view of a diaphragm valve provided in a first embodiment of the present utility model.

Fig. 2 is a cross-sectional view of a diaphragm valve provided in a first embodiment of the present utility model.

Fig. 3 is an enlarged view of the structure at a in fig. 2.

Fig. 4 is a perspective view of a diaphragm pressing plate according to a first embodiment of the present utility model.

Fig. 5 is a cross-sectional view of a diaphragm pressing plate provided in a first embodiment of the present utility model.

Fig. 6 is a cross-sectional view of a valve assembly provided in a first embodiment of the present utility model.

Fig. 7 is a partial cross-sectional view of a valve assembly provided in a first embodiment of the present utility model.

Fig. 8 is a cross-sectional view of a valve body provided in a first embodiment of the present utility model.

Fig. 9 is an enlarged view of the first construction at B in fig. 8. Fig. 10 is an enlarged view of the second construction at B in fig. 8. Fig. 11 is a schematic view showing a state in which the seal portion is sealed and held by the flexible member and the annular projection in fig. 3.

Fig. 12 is a schematic view of a fitting structure of the flexible member, the sealing portion and the annular protrusion provided by the present utility model.

Fig. 13 is a partial cross-sectional view of a valve assembly provided in a second embodiment of the present utility model.

Fig. 14 is a partial cross-sectional view of a valve assembly provided in a third embodiment of the present utility model. The valve comprises a 1-valve body, a 11-inlet flow passage, a 12-outlet flow passage, a 13-valve port, a 14-annular bulge, a 141-convex peak, a 142-first side surface, a 143-second side surface, a 144-wall surface, a 15-groove body, a 16-gap, a 2-valve assembly, a 21-valve core, a 22-membrane part, a 23-sealing part, a 24-root part, a 25-step part, a 3-upper shell, a 30-membrane pressing plate, a 31-flexible part, a 32-pressing ring, a 33-mounting groove, a 34-gap and a 35-blocking part.

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.

Example 1

As shown in fig. 1-2, a diaphragm valve comprises a valve body 1, a valve assembly 2, and an upper housing 3 provided at an axial upper end of the valve body 1; the valve body 1 has an inlet flow passage 11, an outlet flow passage 12, and a valve port 13 for fluid to flow therethrough, the valve port 13 connecting the inlet flow passage 11 and the outlet flow passage 12; the valve assembly 2 comprises a valve core 21, an annular membrane part 22 arranged along the circumferential direction of the valve core 21, and a sealing part 23 arranged on the periphery of the membrane part 21, wherein the valve core 21 axially reciprocates to block or open the valve port 13, so that isolation or communication between the inlet flow channel 11 and the outlet flow channel 12 is realized. In the present embodiment, the valve body 21 reciprocates up and down in the axial direction, taking the direction shown in fig. 2 as an example.

In order to limit the axial movable stroke of the valve assembly 2, the valve assembly 2 is provided with a step portion 25 above the membrane portion 22, the bottom of the upper shell 3 is provided with a blocking portion 35, when the valve assembly 2 moves upwards to the position where the blocking portion 35 is abutted against the step portion 25, the movement is stopped, the excessive upward movement of the valve assembly 2 is effectively avoided, the deformation of the membrane portion 22 caused by excessive stretching is avoided, the service life of the membrane portion 22 is prolonged, the membrane portion 22 is prevented from being separated from the sealing clamping of the flexible piece 31 and the annular protrusion 14, and the effective sealing fit of the valve assembly 2 and the valve main body 1 is ensured.

As shown in fig. 3, a flexible member 31 is provided at the bottom of the upper case 3, and the valve body 1 has an annular projection 14, and the flexible member 31 and the annular projection 14 sandwich the sealing portion 23 in opposition, thereby forming a sealing engagement between the valve assembly 2 and the valve body 1. In other words, the flexible member 31 is pressed against the sealing portion 31 downwards on the upper surface of the sealing portion 23, and the annular protrusion 14 is pressed against the sealing portion 31 upwards on the lower surface of the sealing portion 23, so that the flexible member 31 and the annular protrusion 14 can seal and clamp the sealing portion 31 in the thickness direction of the sealing portion 31, the problem that particles are generated due to mutual extrusion friction between the sealing portion and the annular groove due to the fact that the sealing portion needs to be clamped into the annular groove of the valve main body in the conventional structure is effectively avoided, and the particles can be prevented from entering into the flow channel to pollute the conveyed fluid. At the same time, the precision requirements for the cooperation of the sealing portion 31 and the valve assembly 2 are reduced, and the machining and the installation are more convenient.

By pressing the flexible member 31 against the upper surface of the sealing portion 23, the sealing portion 23 is deformed as a whole, and a large sealing surface is formed between the sealing portion 23 and the annular projection 14, so that the sealing effect is improved. Specifically, as shown in fig. 11 and 12, the sealing portion 23 is pressed against the portion a of the flexible member 31, so that the portion D of the sealing portion 23 forms a seal with the convex peak 141 of the annular protrusion 14, and under the extrusion action of an external force, the flexible member 31 deforms, and the portion B and the portion C of the flexible member continue to flow toward the sealing portion 23 until the portion E and the portion F of the sealing portion 23 press against the annular protrusion 14 to form a seal, thereby achieving the effect of increasing the sealing surface. As shown in fig. 6 and 7, the sealing portion 23 is integrally formed from the outer periphery of the film portion 22, and the included angle between the sealing portion 23 and the film portion 22 is 150 to 180 °, preferably 172 °, that is, the angle α is 150 to 180 ° in fig. 7. Specifically, at this time, the plane of the sealing portion 23 is perpendicular to the axial direction of the valve assembly 2, the included angle between the junction of the membrane portion 22 and the sealing portion 23 and the plane perpendicular to the axial direction of the valve assembly 2 is 150-180 °, and more specifically, taking the direction shown in fig. 6 as an example, the membrane portion 22 is obliquely arranged, and the sealing portion 23 is horizontally arranged. After a long period of use, the horizontal sealing portion 23 sags, that is, the above-mentioned angle α decreases. The thickness of the sealing portion 23 is 0.3-0.7mm, i.e. s1=0.3-0.7 mm in fig. 7, preferably s1=0.5 mm; the thickness of the root portion 24 of the membrane portion 22 connected to the spool 21 is 0.4-0.8mm, that is, s2=0.4-0.8 mm, preferably s2=0.6 mm, and the thickness of the root portion 24 is larger than that of the seal portion 23, so that the thickness of the membrane portion 22 is gradually set between the seal portion 23 and the root portion 24, that is, the cross section of the membrane portion 22 is substantially trapezoidal. The gradual change arrangement prevents abrupt change of thickness between the film portion 22 and the sealing portion 23, prevents stress concentration of the film portion 22 on the sealing portion 23, ensures strength of the film portion 22, and prolongs service life thereof. The gradual change herein means that the thickness of the film portion 22 gradually increases from the sealing portion 23, that is, the sealing portion 23 is relatively thinner, the strength thereof is lower, deformation is more likely to occur, the film portion 22 is relatively thicker, and corrosive gas is less likely to corrode parts in the upper case 3 through the film portion 22 from intermolecular gaps in the film portion 22.

As shown in fig. 8 and 9, the annular projection 14 includes a convex peak 141, a first side surface 142 located inside the convex peak 141, and a second side surface 143 located outside the convex peak 141, where the inside and outside are inside with respect to the central axis near the valve body 1. In this embodiment, the first side surface 142, the convex peak 141 and the second side surface 143 are all arc surfaces and transition smoothly. The first side surface 142, the convex peak 141 and the second side surface 143 are arc surfaces with smooth transition, so that the annular protrusion 14 can be closely attached to the sealing portion 31, the sealing contact area is large, and a good sealing effect is finally achieved. Of course, in other embodiments, the peak 141 may be an arc surface, the first side surface 142 and the second side surface 143 may be planes, or the second side surface 143 and the peak 141 may be arc surfaces, which is not particularly limited.

As mentioned above, the flexible member 31 and the annular projection 14 seal the grip seal portion 31, and more specifically, the flexible member 31 and the second side surface 143 face the grip seal portion 31. If the center of the flexible member 31 is located above the convex peak 141, the sealing portion 31 can form a seal with the first side surface 142, the convex peak 141 and the second side surface 143 at the same time, which can cause excessive angular deformation of the sealing portion 31, and affect the service life of the film portion 22. If the center of the flexible member 31 is located above the radially inner first side surface 142, i.e. a seal is formed inside the ridge 141, the sealing portion 31 occupies the space of the membrane portion 22, the radial dimension of the membrane portion 22 is reduced, and the smaller the radial dimension of the membrane portion 22, the shorter the service life, in case a predetermined amount of deformation of the membrane portion 22 is required. In summary, the center of the flexible member 31 is disposed above the radially outer second side surface 143, that is, the flexible member 31 and the second side surface 143 clamp the sealing portion 31 in opposition, so that the deformation amount of the membrane portion 22 is ensured on the premise of ensuring the service life of the membrane portion 22.

As shown in fig. 3, 8 and 9, the radially outer side of the annular protrusion 14 forms a groove 15, so as to accommodate the end of the sealing portion 23, so that the end of the sealing portion 23 can be attached to the second side surface 143 and then continue downward, thereby avoiding interference between the end of the sealing portion 23 and the inner wall of the valve body 1. As shown in fig. 3, a pressing ring 32 is provided at the bottom of the upper case 3, and is located radially outward of the flexible member 31, and presses the end of the seal portion 23 in the direction in which the groove 15 is located. The pressing ring 32 presses the sealing part 23 downwards, and is matched with the flexible piece 31, the sealing part 23 is firstly enabled to generate larger deformation through the pressing ring 32, then the flexible piece 31 applies acting force to the sealing part 23, so that the sealing part 23 generates relatively smaller deformation, the sealing part 23 is effectively attached to the second side surface 143 of the annular protrusion 14, the sealing part 23 and the second side surface 143 have enough contact area, and effective sealing clamping of the flexible piece 31 and the second side surface 143 to the sealing part 23 is further ensured. The gap 16 is formed between the tail end of the sealing part 23 and the inner wall of the valve body 1, interference between the tail end of the sealing part 23 and the inner wall of the valve body 1 is avoided under the condition that the press ring 32 presses down the tail end of the sealing part 23, radial inward extrusion force is avoided on the sealing part 23 by the inner wall of the valve body 1, so that the sealing part 23 forms a certain degree of curl, even moves to the radial inner side, the reduction of the sealing area is avoided, and effective contact sealing between the sealing part 23 and the annular bulge 14 is ensured.

As shown in fig. 7, if the second side surface 143 forms a sidewall of the groove body 15 and the cambered surface length of the second side surface 143 is L2, as shown in fig. 9, the cambered surface length of the second side surface 143 is equal to or greater than L1 when the second side surface 143 is only the sidewall of the groove body 15, that is, when the second side surface 143 is only the sidewall of the groove body 15, the cambered surface length of the second side surface 143 is equal to or greater than the radial width of the seal portion 23. As shown in fig. 10, the side wall of the tank 15 may further include a wall surface 144 in addition to the second side surface 143, and if the wall surface 144 has a height L3, l2+l3 is equal to or greater than L1, that is, the overall length of the side wall of the tank 15 is equal to or greater than the radial width of the sealing portion 23. Thereby, when the sealing part 23 is pressed downwards by the pressing ring 32, the tail end of the sealing part 23 can not be contacted with the bottom surface of the groove body 15 due to the overlarge radial length of the tail end, so that the bottom surface of the groove body 15 forms extrusion force on the sealing part 23, the sealing part is curled to a certain extent, even the sealing part is deflected upwards, the effective fit between the sealing part 23 and the second side surface 143 is ensured, and then the effective sealing between the sealing part 23 and the annular bulge 14 is ensured.

For convenience of processing, the bottom of the upper case 3 is provided with a diaphragm pressing plate 30, and the blocking portion 35 is provided on the diaphragm pressing plate 30. The bottom of the diaphragm pressing plate 30 is provided with a mounting groove 33, the flexible member 31 is assembled in the mounting groove 33, the outer ring of the flexible member 31 is propped against the outer side wall of the mounting groove 33, and the inner ring of the flexible member 31 is positioned above the first side surface 142 and forms a gap 34 with the inner side wall of the mounting groove 33. The flexible piece 31 is made of a material capable of generating certain elastic deformation, and the outer ring of the flexible piece 31 is propped against the outer side wall of the mounting groove 33, so that the outer end of the flexible piece 31 can better flow downwards to prop against the sealing part 23; a gap 34 is formed between the inner end of the flexible member 31 and the mounting groove 33, so that the inner end of the flexible member 31 can deform towards the direction of the gap 34, the strength of the inner end of the flexible member 31 or the pressure applied to the inner end of the flexible member 31 is reduced, and the inner end of the flexible member 31 can better provide flexible support for the movement of the membrane portion 22.

Example two

As shown in fig. 13, this embodiment is different from the first embodiment in that the included angle between the sealing portion 23 and the membrane portion 22 is 0 °, and at this time, the included angle between the sealing portion 23 and the plane perpendicular to the axial direction of the valve assembly 2 is 150-180 °, that is, the membrane portion 22 and the sealing portion 23 are horizontally integrally connected. In the present embodiment, the plane in which the membrane portion 22 and the sealing portion 23 are located is perpendicular to the axial direction of the valve assembly 2, that is, the membrane portion 22 and the sealing portion 23 are both disposed horizontally. After a long period of use, the horizontal sealing portion 23 sags, and the angle between the membrane portion 22 and the sealing portion 23 is not 180 °, but less than 180 °.

When the sealing portion 23 and the film portion 22 are horizontally integrally connected, the thickness thereof is 0.3 to 0.7mm, preferably 0.5mm.

Other structures are the same as those of the first embodiment, and will not be described again.

Example III

As shown in fig. 14, in the present embodiment, the film portion 22 and the sealing portion 23 are integrally connected, but are not horizontally disposed, but are both disposed obliquely. After a long period of use, the sealing portion 23 sags, and the angle between the film portion 22 and the sealing portion 23 is not 180 °, but less than 180 °.

When the sealing portion 23 and the film portion 22 are horizontally integrally connected, the thickness thereof is 0.3 to 0.7mm, preferably 0.4mm. The thickness of the membrane portion 22 is appropriately reduced, which is advantageous for deformation of the membrane portion 22 and increases the service life of the membrane portion 22.

Other structures are the same as those of the first embodiment, and will not be described again.

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 (12)

1. A diaphragm valve, comprising,

a valve body having an inlet flow passage for fluid flow therethrough, an outlet flow passage, and a valve port connecting the inlet flow passage and the outlet flow passage;

the valve assembly comprises a valve core, a membrane part and a sealing part, wherein the membrane part is arranged along the circumferential direction of the valve core, and the sealing part is arranged on the outer ring of the membrane part;

an upper housing provided at an axial upper end of the valve main body; the method is characterized in that:

the bottom of the upper shell is provided with a flexible piece, the valve main body is provided with an annular bulge, and the flexible piece and the annular bulge clamp the sealing part in opposite directions to form sealing fit of the valve assembly and the valve main body.

2. The diaphragm valve of claim 1 wherein: the sealing part is integrally formed by extending from the outer ring of the membrane part, and the included angle between the sealing part and the membrane part is 150-180 degrees.

3. The diaphragm valve of claim 1 wherein: the radially outer side of the annular projection forms a groove to receive the tip of the seal.

4. A diaphragm valve according to claim 3, characterized in that: the bottom of the upper shell is provided with a compression ring which is positioned at the radial outer side of the flexible piece and presses the tail end of the sealing part towards the direction of the groove body.

5. The diaphragm valve of claim 4 wherein: the end of the sealing portion forms a gap with the inner wall of the valve body.

6. A diaphragm valve according to claim 3, characterized in that: the annular bulge comprises a convex peak, a first side surface positioned on the inner side of the convex peak and a second side surface positioned on the outer side of the convex peak, and the flexible piece and the second side surface clamp the sealing part in opposite directions.

7. The diaphragm valve of claim 6 wherein: the first side surface, the convex peak and the second side surface are all arc surfaces and are in smooth transition.

8. The diaphragm valve of claim 6 wherein: the radial width of the sealing part is L1, and the cambered surface length of the second side surface is L2; the second side surface forms a side wall of the groove body, and then L2 is more than or equal to L1; the side wall of the groove body comprises a second side surface and a wall surface, wherein the height of the wall surface is L3, and then L2+L3 is more than or equal to L1.

9. The diaphragm valve of claim 6 wherein: the bottom of the upper shell is provided with a mounting groove, and the outer ring of the flexible piece is propped against the outer side wall of the mounting groove.

10. The diaphragm valve of claim 9 wherein: the inner ring of the flexible piece is positioned above the first side surface and forms a gap with the inner side wall of the mounting groove.

11. The diaphragm valve of claim 1 or 2, wherein: the thickness of the sealing part is 0.3-0.7mm, the thickness of the root part of the membrane part connected with the valve core is 0.4-0.8mm, the thickness of the root part is larger than that of the sealing part, and the thickness of the membrane part is gradually changed between the sealing part and the root part; or the sealing part and the film part are horizontally and integrally connected, and the thickness of the sealing part and the film part is 0.3-0.7mm.

12. The diaphragm valve of claim 1 wherein: the valve assembly is provided with a step part above the membrane part, the bottom of the upper shell is provided with a blocking part which can prop against the step part to limit the axial movable stroke of the valve assembly.

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