CN112664669A

CN112664669A - Plug valve with elastic automatic compensation seal

Info

Publication number: CN112664669A
Application number: CN202110195676.0A
Authority: CN
Inventors: 邹新鹏; 柯一杭; 张国西; 胡鹏程
Original assignee: Koflow Valve Group Co ltd
Current assignee: Koflow Valve Group Co ltd
Priority date: 2021-02-22
Filing date: 2021-02-22
Publication date: 2021-04-16

Abstract

The invention relates to a plug valve with elastic automatic compensation sealing, which comprises a valve body, a valve cover, a plug body, a valve rod and a transmission mechanism, wherein a bushing between the valve body and the plug body is composed of a left half bushing and a right half bushing, the left half bushing and the right half bushing have an axial gap in the direction of the central line of a valve body channel, a floating sealing pair is formed between the bushing and the plug body, and the abrasion of the sealing pair is automatically compensated; the tapered cylindrical cavity of the valve body can be subjected to finish machining to obtain the inner cavity wall with high precision, the problem that the inner cavity needs to be provided with anti-rotation ribs and cannot be subjected to finish machining in the prior art is solved, and the precision requirement on a valve body casting is lowered. The valve has the advantages of small opening and closing moment, low requirement on the casting precision of the valve body, convenience in processing, high use pressure and the like.

Description

Plug valve with elastic automatic compensation seal

Technical Field

The invention belongs to the field of valves, and particularly relates to a soft sealing plug valve.

Background

The soft sealing plug valve is generally composed of a valve body, a valve cover, a valve rod and a plug body, wherein plastic sealing rings are embedded in the inlet and outlet passage ports of the valve body or fluoroplastic lined in a valve cavity is matched with a conical cylindrical surface of the plug body to form a soft sealing pair. A soft sealing plug valve as CN201610967458.3 is composed of valve body, plug and liner fixed to the wall of flow channel hole

And the plug cock is pressed into the bushing hole and matched with the bushing to form a sealing pair. The main disadvantages are: the outer cylindrical surface of the plug is in sealing contact with the bush in the opening and closing process, the plug generates a large friction force with the bush when rotating, and the opening and closing torque is large, so that the conventional plug valve can only be suitable for a low-pressure working condition; the valve body is generally formed by casting, the bush is pressed in the flow passage hole of the valve body, the anti-rotation rib is generally required to be arranged in the inner cavity of the valve body, the requirement on the quality of a valve body casting is high, and the processing is troublesome.

Disclosure of Invention

Aiming at the defects in the prior art, the invention provides the plug valve with the elastic automatic compensation seal, which has the advantages of small opening and closing moment, low requirement on the casting quality of the valve body, convenient processing and high use pressure.

The technical scheme includes that the valve comprises a valve body, a valve cover, a plug body, a valve rod and a transmission mechanism, wherein the valve body is provided with a conical cylindrical cavity and an inlet and outlet channel communicated with the conical cylindrical cavity; the method is characterized in that: the bushing is composed of a left half bushing and a right half bushing which are positioned on the left side and the right side of the central line of the valve rod, the left half bushing and the right half bushing are respectively provided with a flow passage hole with the same shape and size as the flow passage hole of the plug body, the left half bushing and the right half bushing are pressed in the conical cylindrical cavity of the valve body through the valve cover on the upper end face, and a gap is formed between the opposite end faces of the left half bushing and the right half bushing; the outer cylindrical surfaces of the left half bushing and the right half bushing are provided with rubber sealing rings concentric with the flow channel hole, flexible nonmetal sealing rings concentric with the flow channel hole are embedded in the inner cylindrical surfaces of the left half bushing and the right half bushing, and sealing surfaces of the flexible nonmetal sealing rings matched with the plug body protrude out of the inner cylindrical surfaces of the left half bushing and the right half bushing; the middle positions of the upper end faces of the left half bushing and the right half bushing are respectively provided with an anti-rotation groove, a check block is arranged on the valve cover right above the anti-rotation groove and is embedded in the anti-rotation groove.

In the technical scheme, the peripheries of the flow passage holes of the outer cylindrical surfaces of the left half bushing and the right half bushing are respectively provided with a spring groove, and disc springs are respectively arranged between the spring grooves and the inner cavity wall of the conical cylindrical cavity of the valve body; the outer cylindrical surfaces of the left half lining and the right half lining are respectively provided with a left convex ring and a right convex ring which surround the flow passage hole, the wall of the inner cavity of the tapered cylindrical cavity at the periphery of the flow passage hole of the inlet and outlet channel of the valve body is respectively provided with a groove which is in movable sealing fit with the left convex ring and the right convex ring, and a rubber sealing ring is arranged between the outer annular surface of the left convex ring and the right convex ring and the outer groove wall of the groove which is in mutual fit with the left convex ring and the right.

In the technical scheme, the lower end face of the valve cover is provided with an annular sealing groove concentric with the valve rod mounting hole, an annular sealing gasket is embedded in the annular sealing groove, and the annular sealing gasket is in sealing contact with the upper end face of the plug body; a sealing gasket is arranged between the valve rod and the upper end surface of the valve cover, and the sealing gasket and the annular sealing gasket form a middle cavity double sealing structure.

In the technical scheme, the lower end face of the plug body is provided with a positioning shaft concentric with the valve rod, and the positioning shaft is inserted in a positioning hole in the upper end face of the lower cover.

Compared with the prior art, the invention has the beneficial effects that: the bushing between the valve body and the plug body is composed of a left half bushing and a right half bushing, the left half bushing and the right half bushing have axial clearance in the direction of the center line of a valve body channel, a floating type sealing pair is formed between the bushing and the plug body, and the abrasion of the sealing pair is automatically compensated; the tapered cylindrical cavity of the valve body can be subjected to finish machining to obtain the inner cavity wall with high precision, the problem that the inner cavity needs to be provided with anti-rotation ribs and cannot be subjected to finish machining in the prior art is solved, and the precision requirement on a valve body casting is lowered. The valve has the advantages of small opening and closing moment, low requirement on the casting precision of the valve body, convenience in processing, high use pressure and the like.

Drawings

Fig. 1 is a schematic structural view of the present invention.

Fig. 2 is a schematic structural view of the inner circular surfaces of the left half bushing and the right half bushing of fig. 1 according to the present invention.

In the figure: 1 valve body, 2 left half bushes, 3 cock bodies, 4 left bulge loops, 5 right half bushes, 6 anti-rotation check blocks, 7 valve covers, 8 annular sealing gaskets, 9 sealing gaskets, 10 valve rods, 11 transmission mechanisms, 12 disc springs, 13 flexible non-metal sealing rings, 14 right bulge loops, 15 positioning shafts, 16 lower covers, 17 rubber sealing rings and 18 anti-rotation grooves.

Detailed Description

The plug valve with elastic automatic compensation sealing as shown in fig. 1 comprises a valve body 1, a valve cover 7, a plug body 3, a valve rod 10 and a transmission mechanism 11, wherein the valve body 1 is provided with a tapered cylindrical cavity and an inlet and outlet channel communicated with the tapered cylindrical cavity, the tapered cylindrical cavity is that an inner cavity of the valve body 1 is provided with a conical inner cavity wall to form a tapered cylindrical cavity with an upper port diameter larger than a lower port diameter, the plug body 3 is a tapered cylinder matched with the tapered cylindrical cavity, a flow passage hole matched with the inlet and outlet channel of the valve body 1 is arranged in the plug body 3, the flow passage hole is an upper arc surface and a lower arc surface, two sides of the flow passage hole and the plug body 3 form a square hole with the same taper plane, a bushing is arranged between the plug body 3 and the tapered cylindrical cavity of the valve body 1, and the bushing is made; the method is characterized in that: the bush is composed of a left half bush 2 and a right half bush 5 which are positioned on the left side and the right side of the central line of the valve rod 10, the left half bush 2 and the right half bush 5 are respectively provided with a runner hole with the same size and shape as the runner hole of the cock body 3, the left half bush 2 and the right half bush 5 are pressed in a conical cylindrical cavity of the valve body 1 through a valve cover 7 on the upper end face, the runner holes of the left half bush 2 and the right half bush 5 are aligned with the runner holes of the inlet and outlet channels of the valve body 1, and a gap is formed between the opposite end faces of the left half bush 2 and the right half bush 5 to provide a left-right; the outer cylindrical surfaces of the left half bushing 2 and the right half bushing 5 are provided with rubber sealing rings concentric with the flow passage hole to realize sealing with the inner cavity wall of the tapered cylindrical cavity of the valve body 1, the inner cylindrical surfaces of the left half bushing 2 and the right half bushing 5 are embedded with flexible non-metal sealing rings 13 concentric with the flow passage hole to realize sealing with the plug body 3, as shown in fig. 2, the sealing surfaces of the flexible non-metal sealing rings 13 and the plug body 3 are protruded out of the inner cylindrical surfaces of the left half bushing 2 and the right half bushing 5, so that the plug body 3 and the flexible non-metal sealing rings 13 are mutually matched to form an elastic automatic compensation sealing pair, the contact area between the plug body 3 and the bushing is reduced, the opening and closing torque is reduced, the medium pressure after the sealing surfaces are abraded pushes the left half bushing 2 positioned on the inlet side to be tightly pressed and matched with the plug body 3 for sealing, the abrasion of; the flexible nonmetal sealing ring 13 is a wear-resistant rubber sealing ring and is embedded in dovetail grooves of the left half lining 2 and the right half lining 5 to prevent the flexible nonmetal sealing ring 13 from falling off when the plug body 3 rotates; the middle positions of the upper end faces of the left half bushing 2 and the right half bushing 5 are respectively provided with an anti-rotation groove 18, a valve cover 7 right above the anti-rotation groove 18 is provided with an anti-rotation stop block 6, the anti-rotation stop block 6 is embedded in the anti-rotation groove 18, and the left half bushing 2 and the right half bushing 5 are prevented from being driven to rotate when the plug body 3 rotates.

Spring grooves are respectively formed in the peripheries of flow passage holes in the outer cylindrical surfaces of the left half bushing 2 and the right half bushing 5, disc springs 12 are respectively arranged between the spring grooves and the inner cavity wall of the conical cylindrical cavity of the valve body 1, the left half bushing 2 and the right half bushing 5 are pressed and sealed to the plug body 3, the sealing specific pressure is increased, and the sealing performance is improved; the outer cylindrical surfaces of the left half bushing 2 and the right half bushing 5 are respectively provided with a left convex ring 4 and a right convex ring 14 which surround the flow passage hole, the inner cavity wall of the tapered cylindrical cavity at the periphery of the flow passage hole of the inlet and outlet channel of the valve body 1 is respectively provided with a groove which is in movable sealing fit with the left convex ring 4 and the right convex ring 14, and a rubber sealing ring 17 is arranged between the outer cylindrical surface of the left convex ring 4 and the right convex ring 14 and the outer groove wall of the groove which is in mutual fit with the outer cylindrical surface of the left convex ring 4 and the right convex ring 14, so that the sealing between the left half bushing 2 and the right half bushing. The left convex ring 4 and the left half lining 2 can be integrally processed and formed, and can also be connected by welding; similarly, the right bulge loop 14 can be integrally formed with the right half liner 5, or can be welded.

An annular sealing groove concentric with the valve rod mounting hole is formed in the lower end face of the valve cover 7, an annular sealing gasket 8 is embedded in the annular sealing groove, and the annular sealing gasket 8 is in sealing contact with the upper end face of the plug body 3 to realize sealing of the middle cavity; a sealing gasket 9 is arranged between the valve rod 10 and the upper end surface of the valve cover 7, and the sealing gasket 9 and the annular sealing gasket 8 form a middle cavity double sealing structure.

The lower end surface of the cock body 3 is provided with a positioning shaft 15 concentric with the valve rod 10, and the positioning shaft 15 is inserted into a positioning hole on the upper end surface of a lower cover 16.

The inner cavity of the valve body 1, the left half bushing 2 and the right half bushing 5 can be processed by finish machining to achieve higher processing precision, the precision requirement on a valve body casting is lower, the problems that an anti-rotation rib is arranged in the inner cavity of the valve body in the prior art and is difficult to process and the precision requirement on the valve body casting is high are solved, the production cost of the valve body casting is reduced, the matching precision among the valve body, the bushings and the plug body is improved, and the product performance is improved.

When the flexible non-metal sealing ring 13 and the rubber sealing ring 17 adopt metal sealing rings, the flexible non-metal sealing ring can be used in the working condition of high-temperature medium, and the changes belong to the protection scope of the invention.

Claims

1. A plug valve with elastic automatic compensation sealing comprises a valve body (1), a valve cover (7), a plug body (3), a valve rod (10) and a transmission mechanism (11), wherein the valve body (1) is provided with a conical cylindrical cavity and an inlet and outlet channel communicated with the conical cylindrical cavity, the plug body (3) is a conical cylinder matched with the conical cylindrical cavity, a flow passage hole matched with the inlet and outlet channel of the valve body (1) is formed in the plug body (3), and a bushing is arranged between the plug body (3) and the conical cylindrical cavity of the valve body (1); the method is characterized in that: the bushing is composed of a left half bushing (2) and a right half bushing (5) which are positioned on the left side and the right side of the central line of the valve rod (10), the left half bushing (2) and the right half bushing (5) are respectively provided with a flow passage hole with the same size and shape as those of the flow passage hole of the plug body (3), the left half bushing (2) and the right half bushing (5) are pressed in a conical cylindrical cavity of the valve body (1) through a valve cover (7) on the upper end face, and a gap is reserved between the opposite end faces of the left half bushing (2) and the right half bushing (5); the outer cylindrical surfaces of the left half bushing (2) and the right half bushing (5) are in sealing fit with a tapered cylindrical cavity of the valve body (1), the inner cylindrical surfaces of the left half bushing (2) and the right half bushing (5) are embedded with flexible non-metal sealing rings (13) which are concentric with the flow channel hole, and the sealing surfaces of the flexible non-metal sealing rings (13) and the plug body (3) are protruded out of the inner cylindrical surfaces of the left half bushing (2) and the right half bushing (5); the middle positions of the upper end faces of the left half bushing (2) and the right half bushing (5) are respectively provided with an anti-rotation groove (18), a valve cover (7) right above the anti-rotation groove (18) is provided with an anti-rotation stop block (6), and the anti-rotation stop block (6) is embedded in the anti-rotation groove (18).

2. A plug valve with resilient self-compensating seal as defined in claim 1, wherein: spring grooves are respectively formed in the peripheries of flow passage holes in the outer cylindrical surfaces of the left half bushing (2) and the right half bushing (5), and a disc spring (12) is arranged between each spring groove and the inner cavity wall of the conical cylindrical cavity of the valve body (1); the outer cylindrical surfaces of the left half lining (2) and the right half lining (5) are respectively provided with a left convex ring (4) and a right convex ring (14) which surround the flow passage hole, the inner cavity wall of the tapered cylindrical cavity at the periphery of the flow passage hole of the inlet and outlet channel of the valve body (1) is respectively provided with a groove which is in dynamic sealing fit with the left convex ring (4) and the right convex ring (14), and a rubber sealing ring (17) is arranged between the outer cylindrical surface of the left convex ring (4) and the right convex ring (14) and the outer groove wall of the groove which is mutually matched with the outer cylindrical surface.

3. A plug valve with resilient self-compensating seal according to claim 1 or 2, wherein: an annular sealing groove concentric with the valve rod mounting hole is formed in the lower end face of the valve cover (7), an annular sealing gasket (8) is embedded in the annular sealing groove, and the annular sealing gasket (8) is in sealing contact with the upper end face of the plug body (3); a sealing gasket (9) is arranged between the valve rod (10) and the upper end surface of the valve cover (7), and the sealing gasket (9) and the annular sealing gasket (8) form a middle cavity double sealing structure.