Pneumatic gate valve
Technical field
The present invention relates to a kind of valve.Be a kind of large-scale pneumatic gate valve specifically, be applicable to Chemical Manufacture departments such as poisonous, harmful gas or liquid, be particularly useful in the large-scale nuclear chemical industry system of nuclear material production department.
Background technique
At present, in the large-scale nuclear chemical industry system of nuclear material production department and Chemical Manufacture departments such as other is poisonous, harmful gas or liquid, used large-scale gate valve mostly is a wedge action valve.This wedge action valve contains valve body, and the valve body top has cylinder and driving mechanism successively.Valve body wherein contains valve casing, and this valve casing is a cylinder, and there is the wedge shape valve seat centre of its inner chamber.Flashboard is arranged in the valve casing, and this flashboard is circular, and its diameter equates that with valve seat axial chimb is all arranged on the two sides at its edge, and axially chimb diminishes to downside gradually from its upside, is convenient to the sphenoid surface that cooperates with the wedge shape valve seat with formation.In the middle of the valve casing upper wall valve casing extended cavity is arranged, the oral area of valve casing extended cavity has valve gap, and through hole is arranged on the valve gap.Between valve body and cylinder valve rod is arranged, the valve rod lower end joins with flashboard after passing through hole on the valve gap, and the upper end links to each other with piston after passing the base plate of cylinder.Between cylinder and driving mechanism piston rod is arranged, the lower end of piston rod links to each other with piston after passing the top board of cylinder, and a support is then passed in the upper end and driving mechanism joins.In lower cylinder body on the piston of pressurized air being sent into cylinder respectively, promote piston and move up and down, do elevating movement by piston drive valve rod and flashboard again, thereby realize the open and close of valve.Wherein, the deadweight of moving elements such as the flashboard of large-scale gate valve, valve rod and piston is bigger, is example with DN500 type Pneumatic gate valve, and it is from focusing on about 500kg.When valve closing, because the factor of moving element deadweight, can form sizable inertia impulsive force, impact valve seat with the very large power of closing, make stuck valve " wedge the is dead " fault that promptly occurs between valve seat and flashboard, make that valve can't be opened, pipeline is blocked, even pipelines from bursting, poisonous and harmful gas or leak of liquid accident take place.For avoid can't opening because of valve " wedge is dead " fault, valve occurring, pipeline is blocked the accident that may cause and takes place, and just must take " enforced opening " measure.In order to realize " enforced opening ", people have designed two cylinder gate valves again.This pair of cylinder gate valve is to increase a boosting with serial fashion to open cylinder on the basis of traditional, pneumatic gate valve.The accident that may cause though adopt two cylinders can avoid that " wedge is dead " fault, valve can't be opened, pipeline is blocked takes place.But owing to increased a cylinder, the total height of valve is increased greatly, structure becomes more complicated, and manufacture cost is increased greatly.
Summary of the invention
The problem to be solved in the present invention provides a kind of Pneumatic gate valve.This Pneumatic gate valve can avoid not only that " wedge is dead " fault, valve can't be opened, pipeline is blocked and the accident that may cause takes place, and relatively simple for structure, low cost of manufacture.
For addressing the above problem, take following technological scheme:
Pneumatic gate valve of the present invention contains valve body, and the valve body top has cylinder and driving mechanism successively.Valve body wherein contains valve casing, and this valve casing is a cylinder, and there is the wedge shape valve seat centre of its inner chamber.Flashboard is arranged in the valve casing, and this flashboard is circular, and its diameter equates that with the wedge shape valve seat axial chimb is all arranged on the two sides at its edge, and axially chimb diminishes to downside gradually from its upside, is convenient to the sphenoid surface that cooperates with the wedge shape valve seat with formation.In the middle of the valve casing upper wall valve casing extended cavity is arranged, the oral area of valve casing extended cavity has valve gap, and through hole is arranged on the valve gap.Between valve body and cylinder valve rod is arranged, the valve rod lower end joins with flashboard after passing through hole on the valve gap, and the upper end links to each other with piston after passing the base plate of cylinder.Support, position limit switch and piston rod are arranged between cylinder and driving mechanism, and the lower end of piston rod links to each other with piston after passing the top board of cylinder, and the upper end then passes support and driving mechanism joins.Be characterized between the base plate of piston and cylinder energy storage spring being arranged.This energy storage spring contains some steels dish disks, on the steel dish disk center hole is arranged all, and they are enclosed within by this center hole on that section valve rod between the base plate of piston and cylinder.Wherein, be between steel dish disk after superimposed face-to-face back-to-back more superimposed more together.
Said flashboard contains two plectanes, and all there is axis hole the centre of two plectanes, all is installed with pin in the axis hole, will weld together between the two ends of pin and corresponding plectane by welding manner again.The outside of two plectanes is all to be processed with axial chimb on disconnected the edge, and this two axial chimb diminishes to downside gradually from its upside, is convenient to the sphenoid surface that cooperates with the wedge shape valve seat so that its two sides forms.The junction surface edge of two plectanes is processed with circumferential step accordingly, so that two plectane butt joint backs form the gap between their edge.
Said wedge shape valve seat is made up of two steel loops, and two steel loops are positioned opposite, and their fixed outside is on the inwall of valve casing, and their downside spacing is less than upside, so that form up big and down small wedge shape valve pocket between them.
Take such scheme, have the following advantages:
Owing between the base plate of piston and cylinder, be provided with energy storage spring.In the throttle down process, when flashboard is approaching but when not touching valve seat as yet, piston at first touches energy storage spring, the inertia potential energy that enters cushion stroke and be moving elements such as flashboard is absorbed by energy storage spring and stores, and movement velocity is slowed down.But close under the power effect at cylinder, moving elements such as flashboard continue to move downward.When ram movement to its two sides contacts with the inner side surface of valve seat, just enter shutoff stroke.In the shutoff stroke, energy storage spring continues to be compressed, and stores more energy, and moving elements such as flashboard, valve rod and piston are formed a reaction force.When the need Open valve, the unlatching thrust that produces with cylinder is the main force, and the reaction force of adding energy storage spring can be realized the smooth unlatching of valve as boost.Thereby the accident of having avoided that " wedge is dead " fault, valve can't be opened, pipeline is blocked and may having caused takes place.
Again owing between the base plate of piston and cylinder, be provided with energy storage spring.In the shutoff stroke, energy storage spring can form a reaction force to moving elements such as flashboard, valve rod and pistons.Adopt single cylinder just can realize the smooth unlatching of Pneumatic gate valve.Compare with the two cylinder gate valves in the background technique, not only can reduce valve total height, make the structure of valve become fairly simple, also can reduce manufacture cost greatly.
Description of drawings
Fig. 1 is a Pneumatic gate valve structural representation of the present invention;
Fig. 2 is the rigging position enlarged diagram between energy storage spring and piston, valve rod and valve casing base plate;
Fig. 3 is the single steel dish disk schematic representation in the energy storage spring.
Embodiment
As depicted in figs. 1 and 2, Pneumatic gate valve of the present invention comprises valve body 1, and valve body 1 top has cylinder 10 and driving mechanism successively.Valve body 1 wherein contains valve casing, and this valve casing is a cylinder, and it is lateral arrangement, is processed with valve port on its upper side wall, is provided with the wedge shape valve seat in the middle of the valve shell cavity at valve port place.This wedge shape valve seat contains two steel loops 2, the interior circular diameter of the outside diameter of steel loop 2 and valve casing adapts, and two steel loops 2 are positioned opposite, and their outer side surface is welded on the inwall of valve casing, their downside spacing is less than upside, so that form up big and down small wedge shape valve pocket between them.Be furnished with flashboard 3 in the valve casing, this flashboard also is circular, and its diameter equates with the wedge shape valve seat, all is processed with axial chimb on the two sides at its edge, and axial chimb diminishes to downside gradually from its upside, so that the sphenoid surface that cooperates with the wedge shape valve seat is convenient in its two sides formation.Be provided with valve casing extended cavity 19 in the middle of the valve casing upper wall, this valve casing extended cavity is up big and down small inverted cone, its oral area is provided with valve gap 18, and the oral area of the oral area of valve gap 18 and valve casing extended cavity 19 all is processed with flange, and the two is the sealing shape by bolt 5, nut and this flange and links together.
The top center of valve gap 18 is processed with through hole.Be provided with valve rod 4 between valve body 1 and cylinder, valve rod 4 lower ends are passed behind the through hole on the valve gap 18 and flashboard 3 Joints, and its upper end is fixed in the center hole of piston 9 after passing the base plate 7 of cylinder 10.The center hole outside of the center hole outside at valve gap 18 tops and the base plate 7 of cylinder 10 all is processed with flange, the equal diameters of this two flange, and the two is fixed together by stuffing box packing 6, bolt, nut and sealing shape.
Be provided with support 17, position limit switch 13 and piston rod 11 between the top board 12 of cylinder 10 and driving mechanism, support 17 wherein is in the centre of the top board 12 of cylinder 10, and Zhi Hangcheng switch 13 is installed on the support 17.The centre that is fixed on piston 9 behind the top board 12 of cylinder 10 is passed in the lower end of piston rod 11, and its upper end is then passed support 17 and joined with driving mechanism.Said driving mechanism is mutual vertical configuration engagement by two screw mandrels and forms, the lower end of its vertical screw mandrel 15 is fixed together by the upper end of T shape pin 14 with piston rod 11, one end of its cross lead screw is equipped with handwheel 16, by rotation hand wheel 16, can drive piston rod 11, piston 9, valve rod 4 and flashboard 3 and move up and down.
7 of base plates at piston 9 and cylinder 10 are provided with energy storage spring 8.As Fig. 1, Fig. 2 and shown in Figure 3, said energy storage spring contains six steels dish disks, all is processed with center hole on these six steels dish disks, and they are enclosed within by this center hole on that section valve rod 4 between the base plate 7 of piston 9 and cylinder 10.Wherein, six steels dish disks are divided into three groups, earlier two steels dish disks in every group are during installation superimposed mouth to mouth after, again three groups of steels dish disks are back-to-back and are superimposed together.
Said flashboard 3 contains two plectanes, and the centre of two plectanes is all corresponding is processed with a circle axis hole, wears a pin 21 in corresponding every pair of axis hole earlier, will weld together between the two ends of pin 21 and corresponding plectane by welding manner again.The outside of two plectanes is all to be processed with axial chimb on disconnected the edge, and this two axial chimb diminishes to downside gradually from its upside, is convenient to the sphenoid surface that cooperates with the wedge shape valve seat so that its two sides forms.
The junction surface edge of two plectanes is processed with circumferential step accordingly, so that two plectane butt joint backs form gap 20 between their edge.Like this, can make the periphery of flashboard 3 have certain elasticity in the axial direction, be convenient to closing and opening of valve.