CN111022679A

CN111022679A - Knife gate valve with combined type middle cavity sealing ring

Info

Publication number: CN111022679A
Application number: CN201911404935.5A
Authority: CN
Inventors: 石敬永; 沈克勤
Original assignee: Suzhou Lirui Fluid Control Equipment Co ltd
Current assignee: Suzhou Lirui Fluid Control Equipment Co ltd
Priority date: 2019-12-31
Filing date: 2019-12-31
Publication date: 2020-04-17

Abstract

The invention discloses a knife gate valve with a combined type middle cavity sealing ring, which comprises a valve body, wherein a U-shaped sealing strip is arranged inside the valve body, a flashboard is arranged on the inner side of the U-shaped sealing strip, the middle cavity of the valve body is provided with the middle cavity sealing ring, a packing gland is arranged above the middle cavity sealing ring, a valve rod nut is arranged above the packing gland, and the center of the valve rod nut is connected with a valve rod through threads. In the knife gate valve with the combined type middle cavity sealing ring, a combined type molding framework sealing structure is adopted at the middle cavity position; the contact part of the sealing element and the valve body is static sealing, and a full rubber contact surface is adopted to improve the sealing effect and reliability; novel combination formula shaping skeleton lumen seal structure has the sealing performance that is showing high, the good reliability, and the characteristic that the operating torque is low, and the maintenance volume reduces by a wide margin, and the maintenance cycle is prolonged by a wide margin, and the practicality is stronger.

Description

Knife gate valve with combined type middle cavity sealing ring

Technical Field

The invention relates to the technical field of valves, in particular to a knife gate valve with a combined type middle cavity sealing ring.

Background

Along with scientific and technological development and social progress, various high-performance and compact pipeline control systems are increasingly applied to occasions with small structural space and high performance requirements, such as municipal water supply and drainage, petrochemical industry, high-speed rail locomotives and the like. Due to the limitation of installation space, the conventional gate valve, stop valve, etc. are often too long to be installed in a narrow space. Thus, compact knife gate valves have found widespread use in these areas. The gate plate of the knife gate valve has the structural property of a thin plate and has certain cutting-off capacity, so that the knife gate valve is widely adopted in a medium pipeline system containing long fibers or similar characteristics, so that the fibers can be completely cut off at the fully-closed position of the valve, and the valve is completely closed.

Most knife gate valve lumen sealing washers all adopt shaping to pack or packing to carry out the lumen position seal on the existing market, but because the material characteristic, must adopt the multiunit shaping to pack, or many rings of packing just can realize sealedly, and valve totally seal back lumen position often leads to the operating torque too big because of the tension that packs the gland and press, and typical result is two kinds: one is to reduce the operation torque, but the valve can only bear very low pressure, the valve can only work under ultra-low pressure, another situation, the valve can operate under high pressure, but the operation torque is increased by times, the operation is inconvenient, especially for the self-control valve, a driving mechanism with larger power must be selected, the problems of higher cost and lower performance exist, and the situation of leakage is easy to occur due to the poor elastic characteristic of the material.

Disclosure of Invention

Technical problem to be solved

Aiming at the defects of the prior art, the invention provides a knife gate valve with a combined type middle cavity sealing ring, and solves the problem that the middle cavity sealing performance of most knife gate valves in the existing market is poor. Ordinary knife gate valve lumen sealing washer all adopts shaping filler or packing to carry out the lumen position sealed, but because the material characteristic limits, must adopt the multiunit shaping filler, or many rings of packing just can realize sealing, and the valve totally seals back lumen position often leads to the operating torque too big because the tension that the gland pressed packs, and typical result is two kinds: one is to reduce the operation torque, but the valve can only bear very low pressure, the valve can only work under ultra-low pressure, another situation, the valve can operate under high pressure, but the operation torque is increased by times, the operation is inconvenient abnormally, especially for the automatic control valve, a driving mechanism with larger power must be selected, the problems of higher cost and lower performance exist, and the problem of leakage is easy to occur due to the poor material elastic characteristic of common packing or packing.

(II) technical scheme

In order to achieve the purpose, the invention is realized by the following technical scheme: the utility model provides a knife gate valve with combination formula lumen sealing washer, includes the valve body the internally mounted U type sealing strip of valve body, the inboard of U type sealing strip is equipped with the flashboard, the lumen of valve body is equipped with the lumen sealing washer, the top of lumen sealing washer is equipped with gland, gland's top is equipped with valve-stem nut, threaded connection valve rod is passed through at valve-stem nut's center, apron under the top fixed connection valve rod of valve rod, the top of apron is equipped with the valve rod upper cover plate under the valve rod, the valve rod uide bushing is connected through the mode that cup joints at the top of valve rod.

Preferably, the top of the valve body is fixedly connected with upright columns, and the upright columns are symmetrically distributed.

Preferably, the top of the valve rod is fixedly connected with a hand wheel, and anti-skid stripes are arranged outside the hand wheel.

Preferably, the inside of lumen sealing washer is equipped with the self-lubricating friction disc, the self-lubricating friction disc is the symmetric distribution form.

Preferably, the top of the middle cavity sealing ring is provided with a middle cavity flashboard guide strip, and the top of the middle cavity flashboard guide strip is tightly attached to the packing gland.

(III) advantageous effects

The invention provides a knife gate valve with a combined type middle cavity sealing ring. The method has the following beneficial effects:

the knife gate valve with the combined type middle cavity sealing ring adopts a combined type molding framework sealing structure at the middle cavity position; the contact part of the sealing element and the valve body is static sealing, and a full rubber contact surface is adopted to improve the sealing effect and reliability; the contact part of the sealing element and the flashboard adopts a rubber-coated self-lubricating framework combined sealing structure due to the existence of a motion sealing condition, and a middle cavity flashboard guide sleeve is additionally arranged to accurately position the flashboard, so that the compression amount of the flashboard on rubber can be accurately controlled, high sealing specific pressure under the condition of low compression amount is realized, and the operation torque of the valve is greatly reduced; novel combination formula shaping skeleton lumen seal structure has the sealing performance that is showing high, the good reliability, and the characteristic that the operating torque is low, and the maintenance volume reduces by a wide margin, and the maintenance cycle is prolonged by a wide margin, and the practicality is stronger.

Drawings

FIG. 1 is a schematic structural view of the present invention as a whole;

FIG. 2 is a schematic view of the external structure of the valve of the present invention;

fig. 3 is a partial structural schematic view of the middle chamber sealing ring of the present invention.

In the figure, a valve body-1, a U-shaped sealing strip-2, a flashboard-3, a middle cavity sealing ring-4, a packing gland-5, a valve rod nut-6, an upright post-7, a valve rod-8, a valve rod lower cover plate-9, a valve rod guide sleeve-10, a valve rod upper cover plate-11, a hand wheel-12, a self-lubricating friction plate-13 and a middle cavity flashboard guide strip-14.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Referring to fig. 1-3, an embodiment of the present invention provides a technical solution: the utility model provides a knife gate valve with combination formula lumen sealing washer, includes valve body 1, the internally mounted U type sealing strip 2 of valve body 1, the inboard of U type sealing strip 2 is equipped with flashboard 3, the lumen of valve body 1 is equipped with lumen sealing washer 4, the top of lumen sealing washer 4 is equipped with gland 5, gland 5's top is equipped with valve-stem nut 6, threaded connection valve rod 8 is passed through at valve-stem nut 6's center, apron 9 under the top fixed connection valve rod of valve rod 8, the top of apron 9 is equipped with valve rod upper cover plate 11 under the valve rod, valve rod uide bushing 10 is connected through the mode that cup joints at the top of valve rod 8.

The top of the valve body 1 is fixedly connected with the upright post 7, and the upright post 7 is in a symmetrical distribution form, so that the valve body is uniform in stress, reliable in strength and stable in performance.

The top fixed connection hand wheel 12 of valve rod 8, the outside of hand wheel 12 is equipped with anti-skidding stripe, is equipped with anti-skidding stripe through the outside at hand wheel 12, can avoid the smooth condition of hand that the staff appears when operating this knife gate valve, and the protectiveness is stronger.

The inside of lumen sealing washer 4 is equipped with self-lubricating friction disc 13, self-lubricating friction disc 13 is the symmetric distribution form, through the self-lubricating friction disc 13 that is equipped with, can effectively reduce the frictional force between lumen sealing washer 4 and the stainless steel flashboard 3, very big reduction valve opens and close the moment of torsion.

The top of lumen sealing washer 4 is equipped with lumen flashboard gib block 14, gland 5 is hugged closely at the top of lumen flashboard gib block 14, through the lumen flashboard gib block 14 that is equipped with, can play the effect of supplementary direction, and the practicality is stronger.

The working principle is as follows: when the knife gate valve with the combined type middle cavity sealing ring 4 is applied, firstly, two valve bodies 1 are fixedly connected through bolts and nuts, and a U-shaped sealing strip 2 is arranged in a U-shaped groove in the middle of each valve body 1; the flashboard 3 is U-shaped, an inner cavity penetrates through the middle of the two valve bodies 1, two side faces of the flashboard 3 are attached to the rubber surface of the U-shaped sealing strip 2 to realize sealing, a formed middle cavity sealing ring 4 is installed in the middle cavity at the top of the two valve bodies 1, and a self-lubricating sliding sheet is installed on the inner side of the middle cavity sealing ring 4 and is in contact with the flashboard 3; the integral combined type middle cavity sealing ring 4 and the middle cavity flashboard guide strip 14 are fixed in the middle cavity space of the valve body 1; the top of the middle cavity gate plate guide strip 14 is provided with a packing gland 5, and the packing gland 5 is fixed on the valve body 1 through a bolt; four upright posts 7 are connected and installed on the two-piece type valve body 1 through threads, a lower valve rod cover plate 9 is arranged at the top of each upright post 7, a valve rod 8 penetrates through a valve rod guide sleeve 10 and is installed on the lower valve rod cover plate 9 and is tightly pressed and fixed through a valve rod upper cover plate 11 through a bolt, a valve rod nut 6 is installed on one side of the flashboard 3 through a bolt, the valve rod nut 6 is connected with the valve rod 8 through a trapezoidal thread, a hand wheel 12 is installed at the top of the valve rod 8 through a bolt, the outer side of the middle cavity sealing ring 4 is in contact with the valve body 1, the position is static sealing, and a rubber material; the contact part of the inner side of the middle cavity sealing ring 4 and the flashboard 3 is dynamic sealing, so that a self-lubricating slip sheet with higher hardness is arranged on the inner side of the middle cavity sealing ring 4, the sliding friction coefficient of the self-lubricating slip sheet in contact with the flashboard 3 is extremely low, the friction force between the middle cavity sealing ring 4 and the stainless steel flashboard 3 can be effectively reduced, and the opening and closing torque of the valve is greatly reduced; the self-lubricating slip sheet is positioned in the middle of the middle cavity sealing ring 4 and is contacted with the flashboard 3, so that two sealing structures are formed between the middle cavity sealing ring 4 and the flashboard 3, and the self-lubricating slip sheet has double safety compared with the traditional single-layer sealing; a certain gap exists between the self-lubricating sliding sheet and the rubber due to material difference, so that a labyrinth sealing characteristic is formed, and the valve can bear higher water pressure and keep excellent sealing performance; at the valve totally-closed position, due to the action of one-way water pressure, the flashboard 3 is pushed to one side of low pressure, the middle cavity flashboard guide strip 14 provides a reaction force at the moment, the flashboard 3 is firmly fixed at the middle position of the valve cavity, the rubber compression amount of the middle cavity sealing ring 4 at the two sides of the flashboard 3 is ensured to be completely equal, the situation that the leakage is caused due to the fact that the rubber at one side of the low pressure is excessively compressed and the gap is formed between the pressure-measuring flashboard 3 and the middle cavity sealing ring 4 is avoided, the valve is ensured to bear high pressure for a long time. When the valve is closed: the hand wheel 12 is rotated clockwise, the valve rod nut 6 moves downwards, the gate plate 3 is pushed to enter the valve cavity until the gate plate 3 reaches the bottom of the flow channel to press the U-shaped sealing element, at the moment, the valve is completely closed, and water flows on two sides are completely cut off; because the two sides of the valve body 1 are completely symmetrical, the flashboard 3 and the U-shaped sealing strip 2 can effectively seal water flow no matter which direction the pressure comes from. When the valve is opened: and the hand wheel 12 is rotated anticlockwise, the valve rod nut 6 moves upwards, the gate plate 3 is pulled out from the valve cavity until the bottom of the gate plate 3 is higher than the top of the runner hole, and the knife gate valve is completely opened at the moment. In the whole process of opening and closing the valve, because the optimization of the middle cavity sealing ring 4, the whole opening and closing torque is greatly reduced compared with the traditional middle cavity sealing structure, the sealing reliability is greatly improved, the knife gate valve can be suitable for high-pressure working conditions, and because the combined middle cavity sealing ring 4 adopts low-compression-ratio high-compression-ratio parameters, the position has the characteristic of remarkable low maintenance amount, the maintenance period of the middle cavity position is at least prolonged by 3-5 times compared with that of the traditional valve, and finally, in the whole process of opening and closing the valve, because the valve rod 8 only keeps rotating without up-down movement, the space size required by the valve in the whole process of opening and closing the valve is kept unchanged, and the valve is very suitable for.

The invention relates to a valve body 1, a U-shaped sealing strip 2, a flashboard 3, a middle cavity sealing ring 4, a packing gland 5, a valve rod nut 6, an upright post 7, a valve rod 8, a valve rod lower cover plate 9, a valve rod guide sleeve 10, a valve rod upper cover plate 11, a hand wheel 12, a self-lubricating friction plate 13 and a middle cavity flashboard guide strip 14, wherein the components are all universal standard components or components known by technical personnel in the field, the structure and the principle of the components can be known by technical manuals or conventional experimental methods, and the problem of poor sealing performance of a middle cavity of a traditional knife gate valve on the market is solved. Traditional knife gate valve lumen sealing washer all adopts shaping filler or packing to carry out the lumen position sealed, but because the material characteristic limits, must adopt the multiunit shaping filler, or many rings of packing just can realize sealing, and valve totally seal back lumen position often leads to the operating torque too big because the tension that gland 5 pressed, and typical result is two kinds: one is to reduce the operation torque, but the valve can only bear very low pressure, and the valve can only work under ultra-low pressure, and the other is to operate the valve under high pressure, but the operation torque is multiplied, and the operation is inconvenient, especially for the self-control valve, a driving mechanism with larger power must be selected, the cost is higher, and the performance is lower. And because of the poor elastic characteristic of the material of the middle cavity part, the condition of leakage is easy to occur. According to the invention, through the mutual combination of the components, the combined type molding framework sealing structure is adopted at the middle cavity position; the contact part of the sealing element and the valve body 1 is static sealing, and a full rubber contact surface is adopted to improve the sealing effect and reliability; the contact part of the sealing element and the flashboard 3 adopts a rubber-coated self-lubricating framework combined sealing structure due to the existence of a motion sealing condition, and the flashboard 3 is accurately positioned by the guide sleeve of the middle cavity flashboard 3, so that the compression amount of the flashboard 3 to rubber can be accurately controlled, high sealing specific pressure under the condition of low compression amount is realized, and the operation torque of the valve is greatly reduced; novel combination formula shaping skeleton lumen seal structure has the sealing performance that is showing high, the good reliability, and the characteristic that the operating torque is low, and the maintenance volume reduces by a wide margin, the extension by a wide margin of maintenance cycle, and the practicality is stronger.

While there have been shown and described what are at present considered the fundamental principles and essential features of the invention and its advantages, it will be apparent to those skilled in the art that the invention is not limited to the details of the foregoing exemplary embodiments, but is capable of other specific forms without departing from the spirit or essential characteristics thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. Any reference sign in a claim should not be construed as limiting the claim concerned.

Furthermore, it should be understood that although the present description refers to embodiments, not every embodiment may contain only a single embodiment, and such description is for clarity only, and those skilled in the art should integrate the description, and the embodiments may be combined as appropriate to form other embodiments understood by those skilled in the art.

Claims

1. The utility model provides a knife gate valve with combination formula lumen sealing washer, includes valve body (1), its characterized in that: the internally mounted U type sealing strip (2) of valve body (1), the top of U type sealing strip (2) is equipped with flashboard (3), the lumen of valve body (1) is equipped with lumen sealing washer (4), the top of lumen sealing washer (4) is equipped with gland (5), the top of gland (5) is equipped with valve-stem nut (6), threaded connection valve rod (8) are passed through at the center of valve-stem nut (6), apron (9) under the top fixed connection valve rod of valve rod (8), the top of apron (9) is equipped with valve rod upper cover plate (11) under the valve rod, valve rod uide bushing (10) is connected through the mode that cup joints at the top of valve rod (8).

2. The knife gate valve with the combined middle cavity sealing ring as claimed in claim 1, wherein: the top of the valve body (1) is fixedly connected with the upright posts (7), and the upright posts (7) are symmetrically distributed.

3. The knife gate valve with the combined middle cavity sealing ring as claimed in claim 1, wherein: the top of valve rod (8) fixed connection hand wheel (12), the outside of hand wheel (12) is equipped with anti-skidding stripe.

4. The knife gate valve with the combined middle cavity sealing ring as claimed in claim 1, wherein: the inner part of the middle cavity sealing ring (4) is provided with self-lubricating friction plates (13), and the self-lubricating friction plates (13) are symmetrically distributed.

5. The knife gate valve with the combined middle cavity sealing ring as claimed in claim 1, wherein: the top of lumen sealing washer (4) is equipped with lumen flashboard gib block (14), gland (5) are hugged closely to the top of lumen flashboard gib block (14).