Plug valve with elastic automatic compensation sealing function
Technical Field
The utility model belongs to the valve field, specific soft sealing plug valve that says so.
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
The utility model discloses shortcoming to prior art exists provides one kind and opens and close moment little, low, the processing of valve body casting quality requirement is convenient, service pressure is high have the sealed plug valve of elasticity automatic compensation.
The technical scheme of the utility model 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 plug body 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 is arranged in the plug body, and a lining is arranged between the plug body and the conical cylindrical cavity of the valve body; 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 convex ring.
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.
Compared with the prior art, the utility model beneficial effect be: 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 diagram 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 in 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 of metal material; 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 moving space for the left half bush 2 and the right half bush 5; 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 sealing surfaces is automatically compensated, and the sealing performance is good; 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 5 and the valve body 1 is realized, and the sealing performance is further improved. 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 utility model discloses 1 inner chamber of valve body, left half bush 2, right half bush 5 can adopt the finish machining to reach higher machining precision, and is lower to valve body foundry goods required precision, has solved prior art valve body inner chamber and has set up and has prevented changeing the difficult processing of muscle, to the high problem of valve body foundry goods required precision, reduces the manufacturing cost of valve body foundry goods, improves the cooperation precision between valve body, bush, the cock body, improves and produces the property ability.
The utility model discloses a flexible non-metallic seal 13, rubber seal 17 adopt metal seal, can use in high temperature medium operating mode, and these changes should belong to the protection scope of this invention.