CN218582275U

CN218582275U - Coaxial opposed double-rod lifting stop check valve suitable for easily-blocked medium

Info

Publication number: CN218582275U
Application number: CN202222344094.7U
Authority: CN
Inventors: 张斌; 姚鑫; 梁连金; 林建新
Original assignee: Shk Valve Group Co ltd
Current assignee: Shk Valve Group Co ltd
Priority date: 2022-09-01
Filing date: 2022-09-01
Publication date: 2023-03-07
Anticipated expiration: 2032-09-01

Abstract

A coaxial opposed double-rod lifting type stop check valve suitable for easily blocked media comprises; the valve comprises a valve body (1), and a main valve rod body (3) and an auxiliary valve rod body (20) which are arranged on the valve body (1), wherein a second channel (H2) and a third channel (H3) which are coaxial and are communicated with a staggered shaft medium channel (H1) are respectively arranged above and below the staggered shaft medium channel (H1) in the valve body (1); the lifting double-valve rod is oppositely arranged in the criss-cross staggered shaft medium channel, the second channel and the third channel which are communicated with the staggered shaft medium channel and are coaxially arranged up and down, and the whole valve has the functions of a check valve and a stop valve, so that the installation cost and the installation space of a pipeline are saved. In the process of alternating temperature and stress, the pretightening force of the main valve and the auxiliary valve packing is continuously compensated, the medium is prevented from leaking outwards from the main valve or the auxiliary valve rod, and the personal safety is ensured. The valve is opened only by rotating the auxiliary valve hand wheel, the valve is desilted and prevented from being blocked, and the normal non-return function of the valve is recovered.

Description

Coaxial opposed double-rod lifting stop check valve suitable for easily-blocked medium

Technical Field

The utility model belongs to the technical field of the valve, concretely relates to over-and-under type check valve institutional advancement technique that has stop valve and check valve function simultaneously, especially a stop check valve suitable for easy jam medium.

Background

The stop valve is also called a stop valve, needs to apply pressure and belongs to a forced sealing type valve, so when the valve is closed, pressure must be applied to the valve clack to force a sealing surface not to leak. The check valve belongs to the automatic valve class, and is a valve whose opening and closing piece is a circular valve clack and can produce action by means of its self-weight and medium pressure to block back flow of medium. The stop valve makes the valve clack and the sealing surface of the valve seat tightly fit by means of the pressure of the valve rod, and is suitable for cutting off or regulating the flow. The check valve automatically opens and closes the valve flap by the flowing of the medium, and the purposes of the check valve and the check valve are different: the stop valve is a manual or motorized valve for stopping the liquid feed in the pipeline, and the check valve is used for automatically stopping the liquid from flowing back.

The check valve is typically provided with a handle, whereas the check valve is typically not provided with a screw-on handle. The former are generally manual or electrically operated valves widely used to cut off the supply of liquid in a pipeline, while the latter are generally widely used to automatically prevent the backflow of liquid. The former generally does not require full opening, while the latter requires full opening. The former has no strict requirements on the inlet direction and the outlet direction, while the latter generally has strict requirements on the inlet direction and the outlet direction.

The check valve is an automatic valve which is opened by forward flow medium and closed by backward flow medium, and mainly functions to protect mechanical equipment in a pipeline system by preventing the medium from backward flow. The check valve can be divided into a lifting type, a swing type, a butterfly type, a diaphragm type and other structures according to the relative displacement mode of a closing member and a valve seat of the check valve. One salient feature of the lift check valve, compared to other types of check valves, is that it requires only a short stroke to fully open the valve, and is therefore widely used in petrochemical plants.

Conventional poppet check valve closure members move in a guide mechanism to ensure that the sealing surfaces are flush when closed. However, this guide mechanism has a disadvantage that when the medium is blocked, the movement of the closing member is hindered, the valve is slow to act, and even the function of stopping the movement of the closing member and preventing the medium from flowing backwards is failed. Thus, conventional poppet check valves are only suitable for use with clean media and are not suitable for Yi Zusai media. For example, in a slurry bed residuum hydrotreater, the transport medium is characterized in that the solids dispersed in the liquid phase constitute the slurry state, and the solids mainly include all metals brought by the raw materials, coke powder generated at high temperature in the reaction process, and the catalyst. The slurry medium has a high degree of dispersion of fine solids with a very high tendency to settle. Conventional lift check valves may not open when clogged by solids deposition from the slurry medium. In addition, the conventional lifting check valve only has the function of preventing the media from flowing backwards, cannot completely cut off the media, and usually needs to be matched with a stop valve to completely cut off the media, so that the installation cost of the pipeline is increased. For the pipeline with limited installation space, the matched installation of the stop valve is very troublesome.

SUMMERY OF THE UTILITY MODEL

The utility model aims at providing a coaxial opposition double-pole over-and-under type stop check valve suitable for easily block the medium adopts new valve structure in order to be applicable to easily block the medium, has check valve and stop valve function concurrently to practice thrift piping erection expense and installation space.

The purpose of the utility model is realized by the following technical measures: comprises the following steps of; the valve body, the main valve rod body and the auxiliary valve rod body are arranged on the valve body; a medium channel with staggered shafts in the left and right directions is arranged in the middle of the valve body; meanwhile, a second channel and a third channel which are coaxial and are communicated with the staggered shaft medium channel are respectively arranged above and below the staggered shaft medium channel in the valve body; the second channel is used for installing a main valve flap, a main valve rod body, a spring and a valve cover; the third channel is used for installing the auxiliary valve rod body; the upper section of the auxiliary valve rod body is inserted in the third channel; the staggered-shaft medium channel comprises an inlet section and an outlet section, the inner diameters of the inlet section and the outlet section are the same, and the central axes of the inlet section and the outlet section are parallel to each other, wherein the top surface of the inner wall of the inlet section is not higher than the bottom surface of the inner wall of the outlet section; the central axes of the second channel and the third channel are respectively crossed with the central axes of the outlet section and the inlet section to form an included angle of 45-75 degrees; the inlet section is communicated with the upper port of the third channel, the outlet section is communicated with the upper side of the connecting node of the bottom port of the second channel and the upper port of the third channel, namely the side wall of the bottom of the second channel, a necking inner wall is arranged between the bottom end of the second channel and the upper port of the third channel, and the inner diameter of the necking inner wall is the same as that of the inlet section and the outlet section. The main valve flap is arranged in the lower section of the second channel in the valve body, a matching seat hole which is sleeved with the lower end of the main valve rod body is arranged in the middle of the top surface of the main valve flap, and a ring groove is concentrically arranged outside the matching seat hole to arrange the lower end of the spring. The main valve rod body downwards penetrates through the rear lower section of the valve cover and is sleeved with a spring, the bottom end of the main valve rod body extends into a matching seat hole on the top surface of the main valve flap, the lower end of the spring is clamped into a ring groove on the top surface of the main valve flap, and the top of the spring abuts against the bottom surface of the valve cover; a gap is arranged between the inner wall of the shaft hole in the middle of the valve cover and the outer wall of the main valve rod body, and a main valve packing pressing sleeve is arranged in the gap; the outer edge of the main valve flap is closely matched with the inner wall of the second channel in a close tolerance way; the valve cover is fixed on the valve body at the edge of the upper port of the second passage through a main valve stud and a main valve nut. The valve cover bottom lining gasket is fixedly connected to the valve body.

Particularly, the inner diameter of the second channel is larger than that of the staggered shaft medium channel, and the inner diameter of the staggered shaft medium channel is larger than that of the third channel. The auxiliary valve packing body is pressed tightly at the inner edge of the lower port of the third channel through an auxiliary valve packing pressing sleeve and an auxiliary valve packing pressing cover so as to seal the installation gap between the auxiliary valve rod body and the third channel; the main valve packing body is arranged between the inner wall of the main valve packing pressure sleeve and the outer wall of the main valve rod body, a main valve packing gland is in compression joint with the top of the main valve rod body through the main valve packing pressure sleeve, and the edge of the main valve packing gland is locked and fixed on the valve cover through a main valve packing stud penetrating and connecting a main valve disc spring by a main valve packing compression nut. The edge of the auxiliary valve packing gland is connected with an auxiliary valve disc spring in a penetrating way through an auxiliary valve packing stud and is locked and fixed on the lower port edge of the third channel by an auxiliary valve packing gland nut.

In particular, the upper side edge of the valve cover is vertically provided with a main valve upright post in a threaded fixing way, the top of the main valve upright post is tightly connected with the edge of a main valve support, the upper end of a main valve rod body penetrates through a central hole of the main valve support and is fixed by a threaded pressing ring through a main valve rod nut, and the top end of the main valve rod body is fixedly connected with a main valve hand wheel through the main valve rod nut.

Particularly, a main valve rotation preventing plate is arranged between the valve cover and the main valve support, the main valve rotation preventing plate is fixedly connected with the main valve rod body, and at least one side edge of the main valve rotation preventing plate is clamped or sleeved on the main valve upright post in a sliding mode. An auxiliary valve anti-rotation plate is arranged between the bottom end face of the third channel and the auxiliary valve support, the auxiliary valve anti-rotation plate is fixedly connected with the auxiliary valve rod body, and the edge of at least one side of the auxiliary valve anti-rotation plate is clamped or sleeved on an auxiliary valve stand column in a sliding mode.

In particular, the upper side edge of the valve cover is vertically provided with a main valve upright post in a threaded fixing way, the top of the main valve upright post is tightly connected with the edge of a main valve support, the upper end of a main valve rod body penetrates through a central hole of the main valve support and is fixed by a threaded pressing ring through a main valve rod nut, and the top end of the main valve rod body is fixedly connected with a main valve hand wheel through the main valve rod nut. The edge of the bottom end face of the third channel is downwards connected with an auxiliary valve support through a screwed auxiliary valve stand column, an auxiliary valve support middle hole is penetrated through the lower section of an auxiliary valve rod body, an auxiliary valve rod nut is arranged between the inner wall of the auxiliary valve support middle hole and the outer wall of the auxiliary valve rod body, the auxiliary valve rod nut is fixedly connected with the bottom end of the auxiliary valve rod body through a trapezoidal thread pressing ring, and further, an auxiliary valve rod nut is sleeved and fixed with an auxiliary valve hand wheel on the lower side of the auxiliary valve support.

The utility model discloses an advantage and effect:

(1) The lifting double-valve rod is oppositely arranged in the criss-cross staggered shaft medium channel, the second channel and the third channel which are communicated with the staggered shaft medium channel and are coaxially arranged up and down, and meanwhile, the structure of the inner cavity of the valve is optimized, so that the valve has the functions of a check valve and a stop valve integrally, and the installation cost and the installation space of a pipeline are saved.

(2) The excircle of the main valve flap is in tolerance fit with the second channel of the valve body, so that a medium is easy to block and is not easy to enter the spring hole, the spring is effectively protected, and the spring is prevented from losing efficacy due to the blocking of the medium.

(3) The packing compression structures are provided with disc springs, so that the pretightening force of the packing of the main valve and the auxiliary valve is continuously compensated in the process of alternating temperature and stress, the medium is prevented from leaking outwards from the main valve or the auxiliary valve rod, and the personal safety is ensured.

(4) When the main valve flap slowly moves or stops moving due to medium blockage, the main valve flap is driven to move upwards by only rotating the auxiliary valve hand wheel and pushing the auxiliary valve rod, the valve is opened, the valve is desilted and prevented from being blocked, and the normal non-return function of the valve is recovered.

Drawings

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

FIG. 2 is a schematic view of an anti-rotation plate mounting structure of a main valve in an embodiment.

FIG. 3 is a schematic view of an anti-rotation plate mounting structure of the sub-valve in the embodiment.

The reference numerals include:

1-valve body, 2-main valve flap, 3-main valve stem body, 4-spring, 5-gasket, 6-valve cap, 7-main valve stud, 8-main valve nut, 9-main valve packing body, 10-main valve packing gland, 11-main valve packing gland, 12-main valve packing stud, 13-main valve belleville spring, 14-main valve packing gland nut, 15-main valve anti-rotation plate, 16-main valve column, 17-main valve bracket, 18-main valve stem nut, 19-main valve hand wheel, 20-auxiliary valve stem body, 21-auxiliary valve packing body, 22-auxiliary valve packing gland, 23-auxiliary valve packing gland, 24-auxiliary valve packing stud, 25-auxiliary valve belleville spring, 26-auxiliary valve packing gland nut, 27-auxiliary valve column, 28-auxiliary valve anti-rotation plate, 29-auxiliary valve bracket, 30-auxiliary valve stem nut, 31-auxiliary valve hand wheel.

H1-staggered shaft medium channel, H2-second channel and H3-third channel.

Detailed Description

The utility model discloses a valve has check valve and stop valve function concurrently. The method comprises the following steps: the valve comprises a valve body 1, a main valve rod body 3 and an auxiliary valve rod body 20 which are arranged on the valve body 1, and further comprises a main valve flap 2, a spring 4, a valve cover 6, a main valve upright post 16, a main valve support 17, an auxiliary valve upright post 27 and an auxiliary valve support 29 which are arranged between the main valve rod body 3, the auxiliary valve rod body 20 and the valve body 1. The main valve flap 2 and the main valve stem body 3 are not fixedly connected,

the present invention will be described more fully with reference to the accompanying drawings and examples, wherein the examples are given by way of illustration only, and not by way of limitation. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work belong to the protection scope of the present invention.

The present invention will be further explained with reference to the drawings and examples.

Example 1: as shown in fig. 1, the present invention provides an anti-blocking check valve, which is shown in fig. 1:

a staggered shaft medium channel H1 in the left-right direction is arranged in the middle of the valve body 1 and is used for medium circulation; meanwhile, a second channel H2 and a third channel H3 which are coaxial and are communicated with the staggered shaft medium channel H1 are respectively arranged above and below the staggered shaft medium channel H1 in the valve body 1. The second passage H2 is used to mount the main valve flap 2, main valve stem body 3, spring 4 and bonnet 6. The third passage H3 is for mounting the sub-stem body 20. The upper section of the auxiliary valve rod body 20 is inserted in the third channel H3, and an auxiliary valve packing body 21 is tightly pressed at the inner edge of the lower port of the third channel H3 through an auxiliary valve packing pressing sleeve 22 and an auxiliary valve packing pressing cover 23 so as to seal the installation gap between the auxiliary valve rod body 20 and the third channel H3; the auxiliary valve packing body 21 realizes the sealing of the auxiliary valve rod body 20 under the axial compression of the auxiliary valve packing sleeve 22 and the auxiliary valve packing gland 23.

In the foregoing, the cross-axis medium channel H1 includes an inlet section and an outlet section, the inner diameters of the inlet section and the outlet section are the same and the central axes are parallel to each other, wherein the top surface of the inner wall of the inlet section is not higher than the bottom surface of the inner wall of the outlet section; the central axes of the second channel H2 and the third channel H3 are respectively crossed with the central axes of the outlet section and the inlet section to form an included angle of 45-75 degrees; namely, the inlet section is communicated with the upper port of the third channel H3, then the outlet section is communicated with the upper side of the connecting node of the bottom port of the second channel H2 and the upper port of the third channel H3, namely the side wall of the bottom of the second channel H2, a necking inner wall is arranged between the bottom end of the second channel H2 and the upper port of the third channel H3, and the inner diameter of the necking inner wall is the same as the inner diameters of the inlet section and the outlet section. That is, the bottom surface of the main valve flap 2 just presses against the inner wall of the constriction. In particular, the inner diameter of the second channel H2 is larger than that of the staggered shaft medium channel H1, and the inner diameter of the staggered shaft medium channel H1 is larger than that of the third channel H3. In the state that the top end of the auxiliary valve rod body 20 is in the third channel H3, after the main valve flap 2 rises and retreats into the second channel H2, a communication channel with the same inner diameter is formed from the well head section to the outlet section.

In the foregoing, the main valve flap 2 is installed in the lower section of the second passage H2 in the valve body 1, the middle of the top surface of the main valve flap 2 is provided with a fitting seat hole for sleeving the lower end of the main valve stem body 3, and moreover, a ring groove is concentrically arranged outside the fitting seat hole for accommodating the lower end of the spring 4. The outer edge of the main valve flap 2 is closely matched with the inner wall of the second channel H2 in a tolerance manner. The valve cover 6 is fixed on the valve body 1 at the upper port edge of the second channel H2 through a main valve stud 7 and a main valve nut 8. In particular, a gasket 5 is fixedly connected to the valve body 1 at the bottom of the valve cover 6, so that the medium cannot leak outwards from the joint of the valve body 1 and the valve cover 6. The main valve rod body 3 downwards penetrates through the valve cover 6, the lower section is sleeved with a spring 4, the bottom end of the spring extends into a matching seat hole on the top surface of the main valve flap 2, the lower end of the spring 4 is clamped into a ring groove on the top surface of the main valve flap 2, and the top of the spring 4 abuts against the bottom surface of the valve cover 6; a gap is arranged between the inner wall of a shaft hole in the middle of the valve cover 6 and the outer wall of the main valve rod body 3, a main valve packing pressing sleeve 10 is arranged in the gap, a main valve packing body 9 is arranged between the inner wall of the main valve packing pressing sleeve 10 and the outer wall of the main valve rod body 3, a main valve packing gland 11 is in pressure joint with the top of the main valve rod body 3 through the main valve packing pressing sleeve 10, and the edge of the main valve packing gland 11 is tightly locked and fixed on the valve cover 6 through a main valve packing stud 12 connected with a main valve disc spring 13 in a penetrating mode through a main valve packing pressing nut 14.

In the above, further, the upper side edge of the bonnet 6 is erected with a main valve column 16 by screw thread, the top of the main valve column 16 is tightly connected with the edge of the main valve support 17, the upper end of the main valve stem body 3 passes through the central hole of the main valve support 17 and is fixed by a screw thread pressing ring through a main valve stem nut 18, and the top end of the main valve stem body 3 is fixedly connected with a main valve hand wheel 19 through the main valve stem nut 18. In particular, the top of the main valve stem body 3 is connected to the main valve stem nut 18 by means of a trapezoidal thread. A main valve rotation-proof plate 15 is arranged between the valve cover 6 and the main valve support 17, the main valve rotation-proof plate 15 is fixedly connected with the main valve rod body 3, and at least one side edge of the main valve rotation-proof plate 15 is clamped or slidingly sleeved on a main valve upright post 16. Further, as shown in fig. 2, the middle of the main valve rotation-preventing plate 15 is fixed on the main valve stem body 3 by bolts, and the outer ends of both sides of the main valve rotation-preventing plate 15 are respectively provided with an arc-shaped notch for slidably engaging with the outer wall of the inner side of the main valve column 16 to limit the main valve stem body 3 from moving up and down.

In the foregoing, further, the edge of the bottom end face of the third channel H3 is connected downward to the auxiliary valve support 29 by screwing the auxiliary valve pillar 27, the lower section of the auxiliary valve stem body 20 penetrates through the middle hole of the auxiliary valve support 29, an auxiliary valve stem nut 30 is arranged between the inner wall of the middle hole of the auxiliary valve support 29 and the outer wall of the auxiliary valve stem body 20, the auxiliary valve stem nut 30 is fastened and connected to the bottom end of the auxiliary valve stem body 20 by a trapezoidal thread pressing ring, and further, the auxiliary valve stem nut 30 is sleeved and fixed to the auxiliary valve hand wheel 31 at the lower side of the auxiliary valve support 29. An auxiliary valve anti-rotation plate 28 is arranged between the bottom end face of the third channel H3 and an auxiliary valve support 29, the auxiliary valve anti-rotation plate 28 is fixedly connected with the auxiliary valve rod body 20, and at least one side edge of the auxiliary valve anti-rotation plate 28 is clamped or sleeved on the auxiliary valve upright post 27 in a sliding mode. As shown in fig. 3, the middle of the sub-valve rotation-preventing plate 28 is fixed on the sub-valve rod body 20 through a bolt, and the outer ends of the two sides of the sub-valve rotation-preventing plate 28 are respectively provided with an arc-shaped notch which is slidably clamped on the outer wall of the inner side of the sub-valve upright post 27 to limit the sub-valve rod body 20 to move up and down.

In the above, furthermore, the edge of the sub valve packing gland 23 is connected with a sub valve disc spring 25 through a sub valve packing stud 24 and is locked and fixed on the lower port edge of the third channel H3 by a sub valve packing compression nut 26. The auxiliary valve disc spring 25 enables the pretightening force of the auxiliary valve packing body 21 to be continuously compensated in the process of alternating temperature and stress, so that the medium is prevented from leaking outwards from the auxiliary valve rod body 20, and the personal safety is ensured.

The embodiment of the utility model provides an in, main valve packing body 9 locates in the filler hole of valve gap 6, packs at the main valve and presses cover 10 and main valve gland 11's axial compression under, realizes main valve rod body 3's sealing. When the main valve hand wheel 19 is rotated, the main valve stem body 3 is driven to move up and down through the main valve stem nut 18. Spring 4 provides a secondary closing force to main valve flap 2. The main valve disc 2 and the main valve stem body 3 are not fixedly connected, when the main valve stem body 3 descends and presses the main valve disc 2 tightly on the valve body 1, the medium can be completely cut off, and the function of a stop valve is realized.

The embodiment of the utility model provides an in, it is further, after main valve stem body 3 rises, spacing through the plane of 3 bottoms of main valve stem body, main valve lamella 2 can be opened when following current medium, closes during the refluence medium, realizes the function of check valve. Therefore, the valve has the functions of a check valve and a stop valve, and the installation cost and the installation space of the pipeline are saved.

The embodiment of the utility model provides an in, in temperature and stress alternation, make the pretightning force that the main valve packed body 9 obtain the continuity compensation, stop the medium and outwards leaked from main valve stem body 3, guaranteed personal safety.

The embodiment of the utility model provides an in, the equal surfacing welding carbide of valve body 1 and the 2 sealed faces of main valve lamella has effectively prolonged the life of valve. The excircle of the main valve flap 2 is in tolerance fit with the second channel H2 of the valve body 1, so that a blocking medium is easy to enter a spring hole, the spring 4 is effectively protected, and the spring 4 is prevented from losing efficacy due to the blocking medium.

The embodiment of the utility model provides an in, the valve is normal during operation, and vice valve rod body 20 top is in third passageway H3 and is less than wrong axle medium passageway H1 bottom surface, can not obstruct the easy medium circulation that blocks in the wrong axle medium passageway H1. When the main valve flap 2 moves slowly or even stops moving due to medium blockage, the auxiliary valve hand wheel 31 can be rotated, and the auxiliary valve rod body 20 is driven to move up and down through the auxiliary valve rod nut 30. For example, the auxiliary valve hand wheel 31 is rotated, the auxiliary valve rod body 20 is driven to move upwards through the auxiliary valve rod nut 30, after the top of the auxiliary valve rod body 20 is contacted with the bottom plane of the main valve flap 2, the auxiliary valve hand wheel 31 is continuously rotated, the top end of the auxiliary valve rod body 20 pushes the main valve flap 2 to overcome the tension of the spring 4 to move upwards, the main valve flap 2 is driven to move, the valve is opened, and the dredging and blockage preventing functions are realized. When the main valve flap 2 normally acts, the auxiliary valve hand wheel 31 is rotated reversely to enable the top of the upper end of the auxiliary valve rod body 20 to descend and return to the third channel H3.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present invention, "a plurality" means two or more unless specifically limited otherwise.

In the present invention, unless otherwise explicitly specified or limited, the terms "mounted," "connected," "secured," and the like are to be construed broadly, e.g., as being fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present invention can be understood according to specific situations by those skilled in the art.

In the present disclosure, unless expressly stated or limited otherwise, the first feature "on" or "under" the second feature may comprise direct contact between the first and second features, or may comprise contact between the first and second features not directly. Also, the first feature being "on," "above" and "over" the second feature includes the first feature being directly on and obliquely above the second feature, or merely indicating that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature includes the first feature being directly above and obliquely above the second feature, or simply meaning that the first feature is at a lesser level than the second feature.

Claims

1. A coaxial opposed double-rod lifting type stop check valve suitable for easily blocked media comprises; the valve comprises a valve body (1), and a main valve rod body (3) and an auxiliary valve rod body (20) which are arranged on the valve body (1), and is characterized in that a shaft staggering medium channel (H1) in the left-right direction is arranged in the middle of the valve body (1); meanwhile, a second channel (H2) and a third channel (H3) which are coaxial and are communicated with the staggered shaft medium channel (H1) are respectively arranged above and below the staggered shaft medium channel (H1) in the valve body (1); the second channel (H2) is used for installing the main valve flap (2), the main valve rod body (3), the spring (4) and the valve cover (6); the third channel (H3) is used for installing the auxiliary valve rod body (20); the upper section of the auxiliary valve rod body (20) is inserted in the third channel (H3); the staggered shaft medium channel (H1) comprises an inlet section and an outlet section, the inner diameters of the inlet section and the outlet section are the same, and the central axes of the inlet section and the outlet section are parallel to each other, wherein the top surface of the inner wall of the inlet section is not higher than the bottom surface of the inner wall of the outlet section; the central axes of the second channel (H2) and the third channel (H3) are respectively crossed with the central axes of the outlet section and the inlet section to form an included angle of 45-75 degrees; the inlet section is communicated with the upper end port of the third channel (H3), then the outlet section is communicated with the upper side of the connecting node of the bottom end port of the second channel (H2) and the upper end port of the third channel (H3), namely the side wall of the bottom of the second channel (H2), a necking inner wall is arranged between the bottom end of the second channel (H2) and the upper end port of the third channel (H3), and the inner diameter of the necking inner wall is the same as the inner diameter of the inlet section and the outlet section; a main valve flap (2) is arranged in the lower section of a second channel (H2) in the valve body (1), a matching seat hole which is sleeved with the lower end of the main valve rod body (3) is arranged in the middle of the top surface of the main valve flap (2), and a ring groove is concentrically arranged outside the matching seat hole to arrange the lower end of a spring (4); the main valve rod body (3) downwards penetrates through the rear lower section of the valve cover (6) and is sleeved with the spring (4), the bottom end of the main valve rod body extends into a matching seat hole in the top surface of the main valve flap (2), the lower end of the spring (4) is clamped into a ring groove in the top surface of the main valve flap (2), and the top of the spring (4) is tightly propped against the bottom surface of the valve cover (6); a gap is arranged between the inner wall of the shaft hole in the middle of the valve cover (6) and the outer wall of the main valve rod body (3), and a main valve packing pressing sleeve (10) is arranged in the gap; the outer edge of the main valve flap (2) is closely matched with the inner wall of the second channel (H2) in a tolerance way; the valve cover (6) is fixed on the valve body (1) at the upper port edge of the second channel (H2) through a main valve stud (7) and a main valve nut (8).

2. The coaxial opposed two-rod rising and falling type stop check valve for easily clogged media according to claim 1, wherein the sub valve packing body (21) is pressed at the lower port inner edge of the third passage (H3) by the sub valve packing pressing sleeve (22) and the sub valve packing pressing cover (23) to seal the installation gap of the sub valve stem body (20) and the third passage (H3); a main valve packing body (9) is arranged between the inner wall of a main valve packing pressing sleeve (10) and the outer wall of a main valve rod body (3), a main valve packing gland (11) is pressed and connected between the main valve packing pressing sleeve (10) and the top of the main valve rod body (3), and the edge of the main valve packing gland (11) is locked and fixed on a valve cover (6) through a main valve packing stud (12) which is connected with a main valve disc spring (13) in a penetrating mode by a main valve packing gland nut (14).

3. The coaxial opposed double-rod lift type check valve for easy-clogging media as set forth in claim 1, wherein the second passage (H2) has an inner diameter larger than that of the alternate shaft medium passage (H1), and the alternate shaft medium passage (H1) has an inner diameter larger than that of the third passage (H3).

4. A coaxial opposed double rod elevating type stop check valve adapted to easily clogged media according to claim 1, wherein the bottom lining washer (5) of the valve cap (6) is fixedly attached to the valve body (1).

5. The coaxial opposed double-rod lifting type stop check valve for easy-to-clog medium according to claim 1, wherein the upper side edge of the valve cover (6) is erected with a main valve pillar (16) screwed, the top of the main valve pillar (16) is fastened to the edge of the main valve support (17), the upper end of the main valve rod body (3) passes through the central hole of the main valve support (17), and is fixed by a main valve rod nut (18) using a screw pressing ring, and the top of the main valve rod body (3) is fixedly connected to the main valve hand wheel (19) through the main valve rod nut (18).

6. The coaxial opposed double-rod lifting type stop check valve for easy-to-block medium as claimed in claim 1, wherein a main valve rotation preventing plate (15) is installed between the bonnet (6) and the main valve support (17), the main valve rotation preventing plate (15) is fixedly connected with the main valve rod body (3), and at least one side edge of the main valve rotation preventing plate (15) is clamped or slidingly sleeved on the main valve column (16).

7. The coaxial opposed double-rod lifting type stop check valve suitable for the easily-clogged medium according to claim 1, wherein an auxiliary valve rotation preventing plate (28) is installed between the bottom end face of the third passage (H3) and an auxiliary valve support (29), the auxiliary valve rotation preventing plate (28) is fixedly connected with the auxiliary valve rod body (20), and at least one side edge of the auxiliary valve rotation preventing plate (28) is clamped or slidably sleeved on the auxiliary valve upright post (27).

8. The coaxial opposed double-rod lifting type stop check valve for easily clogged media according to claim 1, wherein the edge of the sub valve packing gland (23) is connected to the sub valve disc spring (25) through a sub valve packing stud (24) and is locked and fixed to the lower port edge of the third passage (H3) by a sub valve packing gland nut (26).

9. The coaxial opposed double-rod lifting type stop check valve for easy-to-clog medium according to claim 1, wherein the upper side edge of the valve cover (6) is erected with a main valve pillar (16) screwed, the top of the main valve pillar (16) is fastened to the edge of the main valve support (17), the upper end of the main valve rod body (3) passes through the central hole of the main valve support (17), and is fixed by a main valve rod nut (18) using a screw pressing ring, and the top of the main valve rod body (3) is fixedly connected to the main valve hand wheel (19) through the main valve rod nut (18).

10. The coaxial opposed double-rod lifting type stop check valve suitable for the easily-clogged medium according to claim 1, wherein the edge of the bottom end surface of the third channel (H3) is connected downward with an auxiliary valve support (29) by screwing an auxiliary valve upright post (27), the lower section of the auxiliary valve rod body (20) penetrates through a middle hole of the auxiliary valve support (29), an auxiliary valve rod nut (30) is arranged between the inner wall of the middle hole of the auxiliary valve support (29) and the outer wall of the auxiliary valve rod body (20), the auxiliary valve rod nut (30) is tightly connected with the bottom end of the auxiliary valve rod body (20) by adopting a trapezoidal thread pressing ring, and an auxiliary valve hand wheel (31) is fixedly sleeved on the lower side of the auxiliary valve support (29) by the auxiliary valve rod nut (30).