CN210135282U

CN210135282U - Fireproof check valve with locking mechanism

Info

Publication number: CN210135282U
Application number: CN201920996576.6U
Authority: CN
Inventors: 张伯华; 周立新; 张会来
Original assignee: Langfang Jindun Huatong Technology Co Ltd; BEIJING JINDUN HUATONG TECHNOLOGY Co Ltd
Current assignee: Langfang Jindun Huatong Technology Co Ltd; BEIJING JINDUN HUATONG TECHNOLOGY Co Ltd
Priority date: 2019-06-28
Filing date: 2019-06-28
Publication date: 2020-03-10
Anticipated expiration: 2029-06-28

Abstract

The utility model discloses a fire prevention check valve with locking mechanism, including disk seat, valve body, solid fixed ring, valve block and first locking mechanism, the end of giving vent to anger of valve body connect in the middle part through-hole of disk seat, gu fixed ring is connected and is fixed in the inside of valve body with the slope mode through the inner wall airtight of periphery and valve body, the valve block passes through the valve block pivot and rotates the inside of connecting in solid fixed ring, the axis of valve block pivot is located the upper portion of valve block makes the valve block rotate around the valve block pivot under the action of gravity of self weight, first locking mechanism connects in the first depression bar of disk seat including rotating, and the distal end of first depression bar is equipped with the first pole head towards the valve block lower part. The utility model discloses a fire prevention check valve has improved the fire prevention effectively and has separated the cigarette effect, can close at any time and improve the reliability.

Description

Fireproof check valve with locking mechanism

Technical Field

The utility model relates to a fire prevention check valve with locking mechanism.

Background

In a residential building or a commercial building, a common exhaust duct is usually arranged in upper and lower stories, and kitchens and toilets in all stories are respectively connected with the common exhaust duct so as to exhaust smoke or foul air into the exhaust duct through exhaust devices such as a range hood and the like. In order to prevent the smoke in the common exhaust duct from flowing backwards, check valves are arranged between the exhaust devices in each kitchen and toilet and the common exhaust duct. In addition, in order to prevent smoke and fire in the common exhaust duct from flowing backward into the room when a fire occurs on other floors, it is required that the check valve should be a fire-proof valve that is automatically closed to prevent the spread of the fire when a fire occurs in other rooms.

However, in the fireproof check valve in the prior art, the valve plate is sometimes adhered to the valve body or cannot be completely closed after being contaminated by oil stains in smoke; in addition, some fireproof check valves can also cause the problem of failure of the fireproof and smoke-isolating function due to the failure of a locking mechanism; furthermore, it is also desirable to be able to manually close the fire check valve when needed to ensure fire and smoke protection. Therefore, there is still a need for an improved fire check valve to further solve the above technical problems.

SUMMERY OF THE UTILITY MODEL

In order to solve the technical problem, the utility model provides a fire prevention check valve with valve block locking mechanism. Particularly, the utility model provides the following technical scheme.

In one aspect, the present invention provides a fire-proof check valve with a locking mechanism, comprising a valve seat, a valve body, a fixing ring, a valve sheet and a first locking mechanism, wherein the valve body is a cylindrical valve body having an air inlet end and an air outlet end, the outer periphery of the air outlet end of the valve body is hermetically connected to the inner edge of the middle through hole of the valve seat, the fixing ring is hermetically connected to the inner wall of the valve body through the outer periphery and is fixed to the inside of the valve body in an inclined manner such that the upper end of the fixing ring is close to the air inlet end of the valve body and the lower end is close to the air outlet end of the valve body, the valve sheet is rotatably connected to the inside of the fixing ring through a valve sheet rotating shaft, the axis of the valve sheet rotating shaft is located at the upper portion of the valve sheet such that the valve sheet can rotate around the valve, the first locking mechanism comprises a first pressure rod which is rotatably connected to the valve seat, a first pressure rod head facing the lower portion of the valve plate is arranged at the far end of the first pressure rod, the first locking mechanism is in an unlocking state and allows the valve plate to rotate around the valve plate rotating shaft when the first pressure rod is rotated to enable the first pressure rod head to move upwards to leave the motion track of the valve plate rotating around the valve plate rotating shaft, and the first locking mechanism is in a locking state and prevents the valve plate from rotating around the valve plate rotating shaft when the first pressure rod is rotated to enable the first pressure rod head to move downwards until the first pressure rod head contacts and presses the upper surface of the lower portion of the valve plate and enables the lower surface of the lower portion of the valve. Under some circumstances, the axis of the valve body and the normal of the valve plate form an included angle of 5-45 degrees.

Further, the near end of the first pressure lever is provided with a first rotating shaft, the first rotating shaft penetrates through a first shaft sleeve arranged on the valve seat to be rotatably connected with the valve seat, and an included angle between the axis of the first rotating shaft and the axis of the valve body is 0-15 degrees.

Furthermore, a first limiting plate is fixedly connected to the first rotating shaft at the position of one side of the valve seat facing the air outlet end, a first limiting block is fixedly connected to the first shaft sleeve, and a first limiting notch and a second limiting notch which are respectively matched with the first limiting block and used for preventing the first rotating shaft from rotating in the first shaft sleeve are formed in the first limiting plate; when the first locking mechanism is in an unlocking state, the first limiting block is positioned in the first limiting notch; when the first locking mechanism is in a locking state, the first limiting block is positioned in the second limiting notch.

Furthermore, a rotating handle is fixedly connected to the tail end of the first rotating shaft, which is located on one side of the valve seat facing the air inlet end, and a first spring in a pressing state is sleeved between the rotating handle and the first shaft sleeve.

Furthermore, a rotating handle is fixedly connected to the tail end of the first rotating shaft, which is located on one side of the valve seat facing the air inlet end, a second limiting block is fixedly arranged on the surface of the rotating handle facing the first shaft sleeve, and a third limiting notch and a fourth limiting notch are arranged on the end surface of the first shaft sleeve facing the rotating handle; when the first locking mechanism is in a locking state, the second limiting block is positioned in the third limiting notch; when the first locking mechanism is in an unlocking state, the second limiting block is positioned in the fourth limiting notch.

Furthermore, on one side of the valve seat facing the air outlet end, one end of the first rotating shaft connected with the first pressure rod is provided with a first blocking piece, and a first spring in a pressing state is sleeved between the first blocking piece and the valve seat.

Furthermore, the lower part of the valve plate is provided with a balancing weight.

Furthermore, the outer fringe cover of valve block is equipped with sealed the pad.

Furthermore, the fireproof check valve with the locking mechanism further comprises a second locking mechanism, the second locking mechanism comprises a second lock box, a second pressure rod and a hot melt piece, the second lock box is fixed on the valve seat or the valve body, one end of the second pressure rod is rotatably connected to the second lock box through a second rotating shaft, the other end of the second pressure rod extends out of the side opening of the second lock box and then extends to the upper side of the valve plate and is provided with a second pressure rod head pointing to the upper part of the valve plate, and the second lock box is further provided with a pressure rod spring for pressing the second pressure rod towards the lower part direction of the valve plate; one end of the hot melt sheet is fixed on the valve seat, and the other end of the hot melt sheet is fixedly connected with the second pressure lever.

Furthermore, the two lock boxes are also provided with a third limiting block for limiting the rotation range of the second pressure rod.

In the description of the present invention, "substantially" does not exclude the meaning of "completely". For example, a component "substantially free" of Y may also be completely free of Y. "substantially" may be deleted from the definition of the invention if desired. "comprising" includes both the recited factors and also allows for the inclusion of additional, non-deterministic factors. "about", "left or right" and the like refer to +/-5%, +/-4%, +/-3%, +/-2%, +/-1%, +/-0.5% of the standard value, where the concentrations of the components are indicated. "and/or" means that the plurality of terms connected thereby can be used individually or in any combination with each other.

In the present invention, examples are generally described in a certain range, which is only for the purpose of concise and clear explanation, but not for the limitation of the present invention. The ranges recited include sub-ranges as well as all individual values within the range. For example, the range of 1 to 6 includes sub-ranges such as 1 to 3, 1 to 4, 1 to 5, 2 to 4, 2 to 6, 3 to 6, etc., and also includes individual values such as 1, 2, 3, 4, 5, 6 within this range.

In the description of the present invention, it is to be understood that the terms "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", and the like indicate orientations or positional relationships based on those shown in the drawings, and are merely for convenience of description of the present invention, and do not indicate or imply that the device or element so referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore, should not be construed as limiting the present invention.

Drawings

Fig. 1 is a schematic front view of the fire check valve with a locking mechanism according to the present invention in an unlocked state;

FIG. 2 is a front view of the check valve of FIG. 1 in a locked state;

FIG. 3 is a left side view schematic view of one embodiment of the fire check valve of FIG. 1;

FIG. 4 is a cross-sectional schematic view of a first locking mechanism of the fire check valve of FIG. 3;

FIG. 5 is a schematic diagram of a right side view of a first limiting plate of the first locking mechanism of the fire check valve shown in FIG. 3;

FIG. 6 is a left side view schematic view of another embodiment of the fire check valve of FIG. 1;

FIG. 7 is a cross-sectional view of the first locking mechanism of the fire check valve of FIG. 6;

FIG. 8 is a front view of the rotating handle and the first bushing of the first locking mechanism of the fire check valve of FIG. 6;

FIG. 9 is a left side view schematic illustration of a first bushing of the first locking mechanism of the fire check valve of FIG. 6;

in the figure: 1-a valve seat; 2-a valve body; 3-an air inlet end; 4, valve plates; 41-valve plate rotating shaft; 42-the upper part of the valve plate; 43-lower part of valve plate; 5-fixing the ring; 61-a first compression bar; 62-a first limiting plate; 621-a first limit notch; 622-second limit indentation; 63-a first shaft; 64-a first sleeve; 641-a third limit notch; 642-a fourth spacing notch; 65-first indenter head; 66-a first spring; 67-rotating the handle; 671-second stopper; 68-a first stopper; 69-a first flap; 7-a second lock box; 71-hot melt sheet; 72-a second compression bar; 73-a second shaft; 74-a third stopper; 75-second indenter head.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. 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.

Referring to fig. 1-9, an aspect of the utility model provides a fire prevention check valve, including disk seat 1, valve body 2, gas vent 3 and valve block 4, wherein the inner edge of the middle part through-hole of disk seat 1 is connected with the periphery of the end of giving vent to anger of valve body 2 airtight and is used for being fixed in exhaust flue's lateral wall with valve body 2, and valve body 2 airtight connection has solid fixed ring 5, and solid fixed ring 5 slopes to set up and makes the one side slope of the end of giving vent to anger up. Valve block 4 is including locating the coaxial valve block pivot 41 of the left and right sides, and rotate with the shaft hole of the inside both sides of solid fixed ring 5 respectively through valve block pivot 41 and be connected, wherein the area that is located valve block upper portion 42 above valve block pivot 41 is less than the area that is located valve block lower part 43 of valve block pivot 41 below, when valve block 4 rotates around valve block pivot 41 under the effect of self weight, valve block upper portion 42 is close and hugs closely solid fixed ring 5 from solid fixed ring 5's left side, valve block lower part 43 is close and hug closely solid fixed ring 5 from solid fixed ring 5's right side, valve block 4 seals solid fixed ring 5's middle part from this, make the. When wind enters the valve body 2 from the air inlet end 3, the wind pressure on the lower part 43 of the valve plate with a larger area is larger than that on the upper part 42 of the valve plate with a smaller area, and the valve plate rotates anticlockwise around the valve plate rotating shaft 41, so that the fireproof check valve is in a ventilation state. In some cases, the inclined fixing ring 5 makes an included angle between the axis of the valve body 2 and the normal of the valve plate 4 be 5-45 degrees, preferably 10-45 degrees, more preferably 15-40 degrees, such as 20 degrees, 25 degrees, 30 degrees, 35 degrees, etc., so as to facilitate the valve plate 4 to close the exhaust port 3 under the action of gravity. In some cases, the weight block is further arranged on the lower portion 43 of the valve plate, so that the weight of the lower portion 43 of the valve plate is increased, and the sealing effect of the valve plate 4 on the fixing ring 5 is further improved.

Under some circumstances, the inner edge of the middle exhaust through hole of the fixing ring 5 is matched with the outer edge of the valve plate 4, so that the close fit degree of the valve plate 4 to the fixing ring 5 is further improved, and the sealing effect is improved. In some cases, the outer edge of the valve plate 4 is also fitted with a gasket made of an elastic material such as rubber to further enhance the sealing action against the fixing ring 5. In some cases, the valve body 2 is cylindrical, the vent hole of the fixing ring 5 is circular, and the valve sheet 4 is circular sheet-shaped and matches the shape of the vent hole of the fixing ring 5.

The fireproof check valve further comprises a first locking mechanism used for locking the valve plate 4 when needed, the first locking mechanism comprises a first pressure rod 61 which is rotatably connected to the side surface of the valve seat 1 facing the air outlet end, and the far end of the first pressure rod 61 is provided with a first pressure rod head 65 facing the lower part 43 of the valve plate. When the first locking mechanism is in the unlocked state (see fig. 1), the first pressure pin head 65 is away from the movement track of the valve plate 4 when rotating around the valve plate rotating shaft 41, for example, at a position above the fixing ring 5 and close to the inner wall of the left side of the valve body 2, so as to allow the valve plate 4 to be normally opened and closed, and thus the fire-proof check valve is in a normal working state. When the first locking mechanism is in a locked state (see fig. 2), the first pressure rod head 65 presses the upper surface of the valve sheet lower portion 43 so that the lower surface of the valve sheet lower portion 43 is tightly attached to the fixing ring 5, thereby preventing the valve sheet 4 from rotating around the valve sheet rotating shaft 41 and enabling the fireproof check valve to be in a locked state. The first locking mechanism may advantageously allow the user to close the fire check valve by locking the valve plate 4 at any time, blocking the passage of gas through the valve body 2. For example, when the room is empty for a long time, the first locking mechanism can be placed in a locking state, and the effects of fire prevention and smoke insulation are ensured.

In some cases, the proximal end of the first pressing rod 61 is provided with a first rotating shaft 63, and the first rotating shaft 63 is rotatably connected with the valve seat 1 through a first sleeve 64 arranged on the valve seat 1. In some cases, the axis of the first rotating shaft 63 is parallel to the axis of the valve body 2, so that the plane of the rotation locus of the first presser head 65 is perpendicular to the axis of the valve body 2; thus, in the closed state of the valve sheet 4, the first presser foot 65 moves away from the upper surface of the valve sheet lower portion 43 when moving upward, and gradually approaches and finally presses the upper surface of the valve sheet lower portion 43 when moving downward. In other cases, the axis of the first rotating shaft 63 is inclined towards the axis of the valve body 2, so that the plane of the rotating track of the first pressure rod head 65 forms an included angle of 1-15 degrees with the axis of the valve body 2; thus, in the closed state of the valve sheet 4, the first presser foot 65 moves upward and away from the upper surface of the valve sheet lower portion 43, and moves downward and approaches and finally presses the upper surface of the valve sheet lower portion 43.

Referring to fig. 3-5, in an embodiment of the present invention, at the position of the valve seat 4 on the side of the air outlet end, the first limiting plate 62 is fixedly connected to the first rotating shaft 63 and the first limiting block 68 is fixedly connected to the first shaft sleeve 64, and the first limiting plate 62 is provided with a first limiting notch 621 and a second limiting notch 622 which are respectively matched with the first limiting block 68 and used for preventing the first rotating shaft 63 from rotating in the first shaft sleeve 64. When the first locking mechanism is in the unlocked state, the first stopper 68 is located in the first stopper notch 621; when the first locking mechanism is in the locked state, the first stopper 68 is positioned in the second stopper notch 622.

Further, a rotating handle 67 is fixedly connected to a distal end of the first rotating shaft 63 on a side of the valve seat 1 facing the air inlet end, and a first spring 66 is sleeved between the rotating handle and the first sleeve 64. The first spring 66 is in a pressing state, and pushes the rotating handle 67 towards the air inlet end 3, so that the first pressure rod head 65 is pulled towards the air inlet end 3 through the first rotating shaft 63 and the first pressure rod 61, so that on one hand, the first limit plate 62 can be tightly attached to the valve seat 1 to keep the first limit block 68 embedded into the first limit notch 621 or the second limit notch 622, and on the other hand, the first pressure rod head 65 can more strongly press the valve plate lower part 43 in a locking state to further enhance the sealing effect.

When the turning handle 67 is pushed to move the first stopper plate 62 away from the valve seat 1, the first stopper notch 621 or the second stopper notch 622 is disengaged from the first stopper 68, thereby allowing the turning handle 67 to turn, so that the first locking mechanism can be switched between the locked state and the unlocked state.

Referring to fig. 6 to 9, in another embodiment of the present invention, a rotating handle 67 is fixedly connected to the end of the first rotating shaft 63 located on one side of the valve seat 1 facing the air inlet, a second limiting block 671 is fixed on the surface of the rotating handle 67 facing the first shaft sleeve 64, and a third limiting notch 641 and a fourth limiting notch 642 are arranged on the end surface of the first shaft sleeve 64 facing the rotating handle 67. When the first locking mechanism is in the locked state or the unlocked state, the second limit block 671 is respectively inserted into the third limit notch 641 or the fourth limit notch 642, so that the first rotating shaft 63 can no longer rotate in the first sleeve 64.

Further, on the side of the valve seat 1 facing the air outlet end, one end of the first rotating shaft 63 connected to the first pressure lever 61 is provided with a first blocking piece 69, and a first spring 66 is sleeved between the first blocking piece 69 and the valve seat 1. The first spring 66 is in a compressed state, and pushes the rotating handle 67 toward the air outlet end, so that the rotating handle 67 is tightly attached to the end surface of the first shaft sleeve 64 to keep the second limiting block 671 embedded in the third limiting notch 641 or the fourth limiting notch 642.

Referring to fig. 1-2, the fire check valve further includes a second locking mechanism for automatically locking the valve plate 4 under high temperature conditions such as fire, the second locking mechanism includes a second lock box 7, a second pressure lever 72 and a heat fuse 71, the second lock box 7 is fixed to the valve seat 1 or the valve body 2, one end of the second pressure lever 72 is rotatably connected to the second lock box 7 through a second rotating shaft 73, the other end of the second pressure lever 72 extends above the valve plate 4 after extending out from a side opening of the second lock box 7 and is provided with a second pressure lever head 75 pointing to the upper portion 42 of the valve plate, the second lock box 7 is further provided with a third limiting block 74 for limiting a rotation range of the second pressure lever 72 and a pressure lever spring for pressing the second pressure lever 72 toward the lower portion 43 of the valve plate. One end of the hot melt sheet 71 is fixed on the valve seat 1, and the other end of the hot melt sheet 71 is fixedly connected with the second pressure lever 72. When the fireproof check valve is in a normal working state and the hot melt piece 71 is intact, the hot melt piece 71 connects the second pressure lever 72 to the valve seat 1 so as to prevent the second pressure lever 72 from rotating, and the second pressure lever head 75 is far away from the track range of the valve plate 4 rotating around the valve plate rotating shaft 41, so that the second locking mechanism is in an unlocked state, and gas is allowed to push the valve plate 4 away to pass through the valve body 2; when the fire-proof check valve is in a high-temperature state such as a fire, and the hot melt piece 71 is melted and disconnected, the second pressure lever 72 is released and rotates towards the lower part 43 of the valve plate under the action of the pressure lever spring until the second pressure lever 72 is stopped by the third limit block 74, the second pressure lever head 75 enters the track range of the valve plate 4 rotating around the valve plate rotating shaft 41, contacts and presses the valve plate 4 to stop the rotation of the valve plate 4 and enable the valve plate 4 to keep closing the exhaust port 3, so that the second locking mechanism is in a locking state, gas is prevented from passing through the valve body 2, and high-temperature gas or flame outside the valve body 2 is prevented from entering the inside of the valve.

In some cases, the first and/or

second struts

61, 72 have elasticity to improve their rotational stability and to improve their pressure on the valve plate 4.

In some cases, the hot melt sheet 71 may be a hot melt metal sheet or other hot melt material sheet that can be melt broken after being heated at or above its operating temperature for a set time. The operating temperature and the set time may be arbitrarily determined according to the working environment of the fire check valve and the conventional regulations and requirements of the related art, for example, the operating temperature may be, for example, 70, 80, 90, 100, 110, 120, 130, 140, 150, 160, 170, 180, 190, 200 degrees celsius or more, preferably 70 degrees celsius, and the set time may be, for example, 5, 10, 20, 30, 40, 50, 60 seconds or more, preferably 10 seconds. The hot melt sheet 71 is a known commercially available product, and can be selected according to the operating temperature and the set time.

In some cases, the above-mentioned various embodiments of the fire check valve of the present invention further comprise a rectification shield disposed on the valve seat 1. For example, when the fireproof check valve is installed on the vertical exhaust passage side wall, the bottom and both sides of the rectification shield are respectively connected to the bottom and both sides of the valve seat 1, so that the rectification shield only has an opening with an upward adjustable opening degree, thereby preventing smoke from entering the rectification shield from below and being adaptable to various environments. In some cases, the lower part of the rectifying shield is bent (tightened) towards the valve seat 1 so that the rectifying shield forms a streamline shape with a small lower part and a large upper part, and the upper part of the rectifying shield is provided with a jet part which contracts inwards, so that the resistance and disturbance of the fireproof check valve to the gas flow in the exhaust flue are reduced, and the exhaust resistance of the fireproof check valve to the exhaust flue is reduced.

In some cases, the left and right sides of the valve seat 1 are also provided with fixing clips for mounting the fire check valve at the air outlet on the side wall of the exhaust duct.

The fireproof check valve is arranged behind the exhaust flue, smoke from the range hood enters from the air inlet end of the valve body 2, is discharged from the air outlet end of the valve body 2 after the valve plate 4 is pushed open, and enters the exhaust flue, and when the range hood stops working, the inclined valve plate 4 is automatically closed under the action of gravity, so that the smoke in the exhaust flue is prevented from flowing backwards. When the fire prevention check valve needs to be locked, the first rotating shaft 63 can be rotated to enable the first pressure rod head 65 to press the valve plate 4, so that the first locking mechanism is in a locking state, and the smoke is prevented from flowing backwards. When high-temperature smoke such as fire occurs in the exhaust flue, the hot melt sheet 71 is fused to release the second pressure lever 72, so that the second pressure lever head 75 presses and closes the valve plate 4, thereby preventing the high-temperature smoke from flowing backwards through the valve body 2 and effectively preventing the fire from spreading.

The utility model discloses a set up in the inside valve block of valve body aslope, utilize gravity to close the valve block, utilize the characteristics of slope valve block to design the first locking mechanism that can close the locking check valve at any time and the second locking mechanism of self-closing check valve under high temperature simultaneously, effectively improved the reliability that the valve block was closed to the device size has been reduced favorably.

It is obvious to a person skilled in the art that the invention is not restricted to details of the above-described exemplary embodiments, but that it can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. 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.

Claims

1. A fireproof check valve with a locking mechanism is characterized by comprising a valve seat, a valve body, a fixing ring, a valve plate and a first locking mechanism, wherein the valve body is a cylindrical valve body with an air inlet end and an air outlet end, the periphery of the air outlet end of the valve body is hermetically connected to the inner edge of a middle through hole of the valve seat, the fixing ring is hermetically connected with the inner wall of the valve body through the periphery and is fixed in the valve body in an inclined mode, the upper end of the fixing ring is close to the air inlet end of the valve body, the lower end of the fixing ring is close to the air outlet end of the valve body, the valve plate is rotatably connected to the fixing ring through a valve plate rotating shaft, the axis of the valve plate rotating shaft is located at the upper part of the valve plate, so that the valve plate can rotate around the valve plate rotating shaft under the action of gravity of the self weight until the lower part of the, the far end of the first pressure lever is provided with a first pressure lever head facing the lower portion of the valve plate, when the first pressure lever is rotated to enable the first pressure lever head to move upwards to leave the movement track of the valve plate rotating around the valve plate rotating shaft, the first locking mechanism is in an unlocking state and allows the valve plate to rotate around the valve plate rotating shaft, and when the first pressure lever is rotated to enable the first pressure lever head to move downwards until the first pressure lever head contacts and presses the upper surface of the lower portion of the valve plate and enables the lower surface of the lower portion of the valve plate to cling to the fixing ring, the first locking mechanism is in a locking state and prevents the valve plate from rotating around.

2. The fireproof check valve with the locking mechanism according to claim 1, wherein the proximal end of the first pressure rod is provided with a first rotating shaft, the first rotating shaft passes through a first shaft sleeve arranged on the valve seat and is rotatably connected with the valve seat, and an included angle between the axis of the first rotating shaft and the axis of the valve body is 0-15 degrees.

3. The fire check valve with the locking mechanism according to claim 2, wherein a first limiting plate is fixedly connected to the first rotating shaft and a first limiting block is fixedly connected to the first shaft sleeve at a position on one side of the valve seat facing the air outlet end, and the first limiting plate is provided with a first limiting notch and a second limiting notch which are respectively matched with the first limiting block and used for preventing the first rotating shaft from rotating in the first shaft sleeve; when the first locking mechanism is in an unlocking state, the first limiting block is positioned in the first limiting notch; when the first locking mechanism is in a locking state, the first limiting block is positioned in the second limiting notch.

4. The fireproof check valve with a locking mechanism according to claim 3, wherein a rotating handle is fixedly connected to the end of the first rotating shaft on the side of the valve seat facing the air inlet end, and a first spring in a pressing state is sleeved between the rotating handle and the first sleeve.

5. The fireproof check valve with the locking mechanism according to claim 2, wherein a rotating handle is fixedly connected to the end of the first rotating shaft located on the side of the valve seat facing the air inlet end, a second limiting block is fixedly arranged on the surface of the rotating handle facing the first shaft sleeve, and a third limiting notch and a fourth limiting notch are arranged on the end surface of the first shaft sleeve facing the rotating handle; when the first locking mechanism is in a locking state, the second limiting block is positioned in the third limiting notch; when the first locking mechanism is in an unlocking state, the second limiting block is positioned in the fourth limiting notch.

6. The fireproof check valve with the locking mechanism according to claim 5, wherein a first stop is provided at the end of the first rotating shaft connected to the first pressure rod on the side of the valve seat facing the air outlet end, and a first spring in a pressing state is sleeved between the first stop and the valve seat.

7. The fireproof check valve with locking mechanism of any one of claims 1-6, wherein the lower part of the valve plate is provided with a counterweight.

8. The fireproof check valve with locking mechanism of any one of claims 1-6, wherein the outer edge of the valve plate is sleeved with a sealing gasket.

9. The fire prevention check valve with a locking mechanism according to any one of claims 1 to 6, further comprising a second locking mechanism, wherein the second locking mechanism comprises a second lock box, a second compression bar and a thermal fuse, the second lock box is fixed on the valve seat or the valve body, one end of the second compression bar is rotatably connected to the second lock box through a second rotating shaft, the other end of the second compression bar extends to the upper side of the valve plate after extending out of the side opening of the second lock box and is provided with a second compression bar head pointing to the upper part of the valve plate, and the second lock box is further provided with a compression bar spring for pressing the second compression bar towards the lower part of the valve plate; one end of the hot melt sheet is fixed on the valve seat, and the other end of the hot melt sheet is fixedly connected with the second pressure lever.

10. The fire protection check valve with a locking mechanism of claim 9, wherein the two lock boxes are further provided with a third stopper for limiting a rotation range of the second pressing rod.