Fire check valve

Abstract

The present invention relates to a fire prevention check valve, which solves the problem that the fire prevention check valve will automatically fail in a low-temperature environment. The fire prevention check valve includes a body, a valve plate, a connecting rod, an elastic element and a dial. An exhaust port is provided on the body. The connecting rod connects the valve plate and the body and is used to drive the valve plate to close the exhaust port. One end of the elastic element is arranged on the body, and the other end of the elastic element is arranged on the dial and is used to drive the dial to rotate relative to the body. It further includes a fusing mechanism and a stop plate. The stop plate is clamped between the fusing mechanism and the body. A rotation stopping portion is provided on the stop plate. When the stop plate is clamped between the fusing mechanism and the body, the rotation stopping portion is arranged on the dial to prevent the dial from rotating relative to the body. After the fusing mechanism acts, the stop plate moves relative to the body and separates the rotation stopping portion from the dial.

Description

Technical Field

[0001] The present invention relates to a fireproof check valve. Background Art

[0002] The locking structure (for the specific structure, reference can be made to the utility model patent with the publication number CN206830892) includes a valve seat, a flap, a temperature sensing element and an elastic element. The flap is rotatably connected to the valve seat. One end of the elastic element is arranged on the valve seat, and the other end of the elastic element is connected to the flap and drives the flap to abut against the temperature sensing element.

[0003] Since the temperature sensing element includes a first copper sheet and a second copper sheet, the first copper sheet and the second copper sheet are integrally connected by a fusible solder. The first copper sheet is fixedly connected to the valve seat, and the second copper sheet abuts against the flap. Therefore, when the other end of the elastic element is connected to the flap and drives the flap to abut against the temperature sensing element, the second copper sheet is always subjected to an upward torsional force. This results in that after the second copper sheet works for a period of time and the connecting force of the fusible solder used to connect the first copper sheet and the second copper sheet < the torsional force of the second copper sheet, the second copper sheet will be separated from the first copper sheet.

[0004] The locking structure is used for a fireproof check valve. The fireproof check valve includes a valve body, a valve flap and a connecting rod. The valve seat is arranged on the valve body. The connecting rod is used to connect the valve flap and the valve seat. After the second copper sheet is separated from the first copper sheet, the elastic element pushes the flap to rotate relative to the valve seat and abut against the connecting rod. The connecting rod drives the valve flap to close the exhaust port on the valve body under the push of the flap. This causes the fireproof check valve to automatically fail in a low-temperature environment. Summary of the Invention

[0005] The problem to be solved by the present invention is to provide a fireproof check valve to avoid the automatic failure of the fireproof check valve in a low-temperature environment.

[0006] To solve the above problems, the present invention provides the following technical solutions:

[0007] The fireproof check valve includes a body, a valve flap, a connecting rod, an elastic element and a flap. An exhaust port is provided on the body. The connecting rod connects the valve flap and the body and is used to drive the valve flap to close the exhaust port. The flap is rotatably arranged on the body. One end of the elastic element is arranged on the body, and the other end of the elastic element is arranged on the flap and is used to drive the flap to rotate relative to the body. The fireproof check valve further includes a temperature sensing mechanism and a stop plate. The stop plate is clamped between the temperature sensing mechanism and the body. A rotation stopping portion is provided on the stop plate. When the stop plate is clamped between the temperature sensing mechanism and the body, the rotation stopping portion is arranged on the flap to prevent the flap from rotating relative to the body. After the temperature sensing mechanism acts, the stop plate moves relative to the body and separates the rotation stopping portion from the flap.

[0008] In the present invention, the fire prevention check valve includes a temperature sensing mechanism and a stop plate. The stop plate is clamped between the temperature sensing mechanism and the body. Among them, the stop plate is provided with an anti-rotation portion. When the stop plate is clamped between the temperature sensing mechanism and the body, the anti-rotation portion is arranged on the flap to prevent the flap from rotating relative to the body; by means of the anti-rotation portion arranged on the flap by the stop plate to prevent the flap from rotating relative to the valve body, compared with the prior art, the stop plate will not have the problem that the fusible solder cannot withstand the torsional force of the second copper sheet, resulting in the separation of the second copper sheet from the first copper sheet. This means that the stop plate can effectively ensure the "continuous" and reliable operation of the fire prevention check valve in a low-temperature environment (the low-temperature environment refers to the ambient temperature where the fire prevention check valve is located is lower than the melting point of the temperature sensing mechanism). Designed in this way, the fire prevention check valve will not automatically fail in a low-temperature environment.

[0009] In the present invention, after the temperature sensing mechanism acts, the stop plate moves relative to the body and separates the anti-rotation portion from the flap. Designed in this way, the fire prevention check valve will close the exhaust port through the valve plate in a high-temperature environment (the high-temperature environment refers to the ambient temperature where the fire prevention check valve is located is higher than the melting point of the temperature sensing mechanism), so that the fire prevention check valve can play the role of fire prevention and smoke isolation.

[0010] Further, the body includes a valve body, a valve seat and a fixing plate. The connecting rod, the flap and the fixing plate are arranged on the valve seat. The valve seat is arranged on the valve body. The stop plate is clamped between the temperature sensing mechanism and the fixing plate. When the connecting rod, the flap and the fixing plate are arranged on the valve seat, and the valve seat is arranged on the valve body, the connecting rod, the flap, the fixing plate, the stop plate and the valve seat can form an integral structure after assembly. This integral structure can be used to connect valve bodies and valve plates of different specifications. In addition, the installation position of the valve seat relative to the valve body can be changed and the installation position of the fixing plate relative to the valve seat can be changed; or, the body includes a valve body and a valve seat. The connecting rod and the flap are arranged on the valve seat. The valve seat is arranged on the valve body. The stop plate is clamped between the temperature sensing mechanism and the valve seat. When the connecting rod and the flap are arranged on the valve seat, and the valve seat is arranged on the valve body, the connecting rod, the flap, the stop plate and the valve seat can form an integral structure after assembly. This integral structure can be used to connect valve bodies and valve plates of different specifications. In addition, the installation position of the valve seat relative to the valve body can be changed; or, the body includes a valve body and a fixing plate. The connecting rod, the flap and the fixing plate are arranged on the valve body. The stop plate is clamped between the temperature sensing mechanism and the fixing plate. This structure can omit the valve seat to reduce the number of parts and assembly steps of the fire prevention check valve; or, the body includes a valve body. The connecting rod and the flap are arranged on the valve body. The stop plate is clamped between the temperature sensing mechanism and the valve body. This structure can omit both the valve seat and the fixing plate to reduce the number of parts and assembly steps of the fire prevention check valve.

[0011] Further, the fire prevention check valve further includes a first bolt and a first nut. The first bolt passes through the fixing plate, one side of the valve seat, the connecting rod, and the other side of the valve seat, and is then threadedly connected to the first nut. This structure uses the existing structure to install the fixing plate on the valve seat, which reduces the increase in manufacturing cost caused by structural improvement to a certain extent.

[0012] Further, the temperature sensing mechanism includes a fastener and a fusing component. The fastener is arranged on the base, the fusing component is arranged on the fastener, and the stop plate is clamped between the fusing component and the base. After the fusing component operates, the stop plate moves axially along the fastener and separates the anti-rotation portion from the dial.

[0013] In the present invention, the fastener has two functions: 1. The fastener is arranged on the base to define the installation positions of the fusing component and the stop plate; 2. The fastener provides a supporting force for the fusing component to enable the stop plate to be clamped between the fusing component and the base.

[0014] Further, the fusing component includes a first metal plate, a second metal plate, and a solder for connecting the first metal plate and the second metal plate. The first metal plate and the second metal plate are respectively arranged on the fastener. The gap between the first metal plate and the second metal plate in the axial direction of the fastener is the axial movement range of the stop plate on the fastener; both the first metal plate and the second metal plate are L-shaped. The first metal plate includes a first connecting portion and a first welding portion formed by bending the first connecting portion. The second metal plate includes a second connecting portion and a second welding portion formed by bending the second connecting portion. The first welding portion and the second welding portion are connected into one body by the solder. After the first welding portion and the second welding portion are connected into one body by the solder, the gap between the first connecting portion and the second connecting portion is the axial movement range of the stop plate on the fastener; a first avoidance hole for avoiding the fastener is provided on the first connecting portion, a second avoidance hole for avoiding the fastener is provided on the second connecting portion, the aperture of the first avoidance hole > the aperture of the second avoidance hole, and the first connecting portion can abut against the stop plate.

[0015] Furthermore, the fuse assembly includes at least one fuse piece, and the fuse piece includes a first fuse part, a second fuse part, and a third fuse part for controlling the axial movement range of the stop plate on the fastener, the first fuse part and the second fuse part are respectively arranged on the fastener, and the third fuse part is used to connect the first fuse part and the second fuse part. In a high temperature environment, as long as one of the first fuse part, the second fuse part, and the third fuse part of the fuse assembly is melted, the fire check valve can play the role of fire and smoke isolation. Such a design shortens the reaction time required for the fire check valve to play the role of fire and smoke isolation in a high temperature environment.

[0016] Furthermore, the fuse assembly further includes a stop ring, which is made of fusible solder or metal, and is clamped between the first fuse part and the second fuse part; or, the stop ring is clamped between two adjacent fuse pieces. Such a design increases the anti-deformation ability of the fuse piece to prevent the fire check valve from automatically failing in a low temperature environment.

[0017] Furthermore, the fuse assembly includes at least one fuse ring, which is provided with a mounting hole, and is sleeved on the fastener and used to control the axial movement range of the stop plate on the fastener. The fuse ring can be used to prevent the fire check valve from automatically failing in a low temperature environment.

[0018] Furthermore, the stop plate is further provided with a clamping portion, the clamping portion and the anti-rotation portion are arranged on the same side of the stop plate, and a limit channel is arranged on the stop plate. After the temperature sensing mechanism is actuated, the stop plate moves axially along the limit channel and separates from the paddle. With such a design, the molding process of the stop plate is simple and the processing speed is fast. In addition, the clamping portion and the anti-rotation portion are arranged on the same side of the stop plate, which can reduce the volume of the stop plate.

[0019] Further, the limiting channel is an elliptical hole, the long axis section of the elliptical hole is arranged vertically, and the short axis section of the elliptical hole is arranged horizontally; or, the limiting channel is a polygonal hole, the vertical length of the polygonal hole is greater than the horizontal length of the polygonal hole; or, the limiting channel is an irregular hole, the vertical length of the irregular hole is greater than the horizontal length of the irregular hole. With such a design, the stop plate can slide and / or rotate along the fastener to avoid the stop plate being stuck on the fastener when the stop plate cannot slide along the fastener and causing the stop plate to be unable to move.

[0020] Further, the fastener includes a screw, which sequentially passes through the fusing assembly and the stop plate and is threadedly connected to the body; alternatively, the fastener includes a second bolt and a second nut, and the second bolt sequentially passes through the fusing assembly, the stop plate, and the body and is threadedly connected to the second nut; alternatively, the fastener includes a second bolt and a second nut, and the second bolt sequentially passes through the stop plate, the body, and the fusing assembly and is threadedly connected to the second nut. When the fastener includes a screw, the screw can conveniently change the distance between the screw head and the body to adjust the clamping force received by the stop plate. When the fastener includes a second bolt and a second nut, the second bolt can conveniently change the distance between the second bolt head and the body to adjust the clamping force received by the stop plate; the second nut can increase the connection strength between the second bolt and the body. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 is a perspective view of the fire check valve in the preferred embodiment of the present invention;

[0022] Figure 2 is a top view of the fire check valve in the preferred embodiment of the present invention;

[0023] Figure 3 is Figure 2 the cross-sectional view at B-B in Embodiment 1;

[0024] Figure 4 is a perspective view of the locking structure in the preferred embodiment of the present invention;

[0025] Figure 5 is a top view of the locking structure in the preferred embodiment of the present invention;

[0026] Figure 6 is Figure 5 the cross-sectional view at A-A in Embodiment 1;

[0027] Figure 7 is Figure 5 the cross-sectional view at A-A in Embodiment 2;

[0028] Figure 8 is Figure 5 the cross-sectional view at A-A in Embodiment 3;

[0029] Figure 9 is a perspective view of a part of the locking structure in the preferred embodiment of the present invention;

[0030] Figure 10 is a cross-sectional view of the fusing assembly in Embodiment 4 of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0031] The technical solutions of the embodiments of the present invention will be explained and described below with reference to the accompanying drawings of the embodiments of the present invention. However, the following embodiments are only the preferred embodiments of the present invention, not all of them. Based on the embodiments in the implementation manners, other embodiments obtained by those skilled in the art without creative efforts all fall within the protection scope of the present invention.

[0032] Embodiment 1

[0033] Refer to Figure 1 、 Figure 2 and Figure 3 , the fire prevention check valve includes a body 1, a valve disc 7, a connecting rod 2, an elastic element and a dial 3. An exhaust port 131 is provided on the body 1. The connecting rod 2 connects the valve disc 7 and the body 1 and is used to drive the valve disc 7 to close the exhaust port 131. The dial 3 is rotatably arranged on the body 1. One end of the elastic element is arranged on the body 1, and the other end of the elastic element is arranged on the dial 3 and is used to drive the dial 3 to rotate relative to the body 1.

[0034] It should be noted that: the existing elastic element is a torsion spring, and the torsion spring is sleeved on the rotating shaft of the dial 3. When the torsion spring is sleeved on the rotating shaft of the dial 3, one end of the torsion spring is fixed on the base 1 in a plug-in manner, and the other end of the torsion spring abuts against the upper end surface of the dial 3. Since the elastic element is not the focus of the present invention, therefore, the structure of the elastic element and the connection structure between the elastic element and other components are not specifically limited in this embodiment. In other words, in this embodiment, the elastic element can be selected as a helical spring, and the elastic element can also be selected as a spring piece. The helical spring and the spring piece can be arranged on the base 1 and the dial 3 in a manner different from the torsion spring, as long as the helical spring or the spring piece can drive the dial 3 to rotate relative to the base.

[0035] Refer to Figure 4 , the difference from the prior art is that: the locking structure of this embodiment further includes a temperature sensing mechanism 4 and a stop plate 5. The stop plate 5 is clamped between the temperature sensing mechanism 4 and the body 1. A rotation stopping portion 51 is provided on the stop plate 5. When the stop plate 5 is clamped between the temperature sensing mechanism 4 and the body 1, the rotation stopping portion 51 is arranged on the dial 3 to prevent the dial 3 from rotating relative to the body 1. After the temperature sensing mechanism 4 acts, the stop plate 5 moves relative to the body 1 and separates the rotation stopping portion 51 from the dial 3.

[0036] Refer to Figure 1 and Figure 3, the body 1 of this embodiment includes a valve body 13, a valve seat 11 and a fixing plate 12. The connecting rod 2, the paddle 3 and the fixing plate 12 are arranged on the valve seat 11, the valve seat 11 is arranged on the valve body 13, and the stop plate 5 is clamped between the temperature sensing mechanism 4 and the fixing plate 12. In other embodiments of the present invention, the body includes a valve body and a valve seat, the connecting rod and the paddle are arranged on the valve seat, the valve seat is arranged on the valve body, and the stop plate is clamped between the temperature sensing mechanism and the valve seat; or, the body includes a valve body and a fixing plate, the connecting rod, the paddle and the fixing plate are arranged on the valve body, and the stop plate is clamped between the temperature sensing mechanism and the fixing plate; or, the body includes a valve body, the connecting rod and the paddle are arranged on the valve body, and the stop plate is clamped between the temperature sensing mechanism and the valve body.

[0037] See Figure 5 , in this embodiment, the fire check valve further includes a first bolt 8 and a first nut 9. The first bolt 8 passes through one side 12 of the fixing plate 12, one side of the valve seat 11, the connecting rod 2, the other side of the valve seat 11 and the other side of the fixing plate 12 and is threadedly connected to the first nut 9. With such a design, the connecting rod 2 is rotatably arranged on the body 1. In other embodiments of the present invention, a rotating shaft is provided on the connecting rod, and a shaft hole is provided on the valve seat. The rotating shaft is inserted into the shaft hole to realize the rotational connection between the connecting rod and the valve seat.

[0038] See Figure 5 and Figure 6 , the temperature sensing mechanism 4 of this embodiment includes a fastener 41 and a fusing assembly. The fastener 41 is arranged on the body 1, the fusing assembly is arranged on the fastener 41, the stop plate 5 is clamped between the fusing assembly and the body 1, and after the fusing assembly acts, the stop plate 5 moves axially along the fastener 41 and separates the anti-rotation portion 51 from the paddle 3. This embodiment only lists the components of one of the temperature sensing mechanisms. In other embodiments of the present invention, the temperature sensing mechanism can be other structures. For example: the temperature sensing mechanism only includes shape memory alloy, the stop plate is clamped between the shape memory alloy and the base, and the shape memory alloy deforms in a temperature sensing environment, which causes the clamping force on the stop plate to disappear; or, the temperature sensing mechanism only includes a fusing assembly, and the stop plate is clamped between the fusing assembly and the body; or, the temperature sensing mechanism includes a mounting plate arranged on the body and a fusing assembly, the fusing assembly is arranged on the mounting plate, and the stop plate is clamped between the fusing assembly and the body. Therefore, all locking structures in which the stop plate is clamped between the fusing assembly and the body are within the protection scope of the present invention.

[0039] Preferably, the fusing component includes at least one fusing piece 42. The fusing piece 42 includes a first fusing part 422, a second fusing part 423, and a third fusing part 421 for controlling the axial movement range of the stop plate 5 on the fastener 41. The first fusing part 422 and the second fusing part 423 are respectively arranged on the fastener 41, and the third fusing part 421 is used to connect the first fusing part 422 and the second fusing part 423.

[0040] See Figure 6 and Figure 9 , a clamping part 53 is further arranged on the stop plate 5 of this embodiment. The clamping part 53 and the anti-rotation part 51 are arranged on the same side of the stop plate 5. A limiting channel 521 is arranged on the stop plate 5. After the temperature-sensing mechanism 4 acts, the stop plate 5 moves axially along the limiting channel 521 and separates from the dial 3.

[0041] From Figure 6 It can be seen that the limiting channel 521 of this embodiment is an oval hole. The long axis section of the oval hole 521 is arranged vertically, and the short axis section of the oval hole is arranged horizontally. Designed in this way, the stop plate 5 can slide along the fastener 41, and the stop plate 5 can also rotate along the fastener 51. This means that when the stop plate 5 cannot slide along the fastener 41, the stop plate 5 can rotate around the fastener 51 to further increase the working reliability of the dial 3. In other embodiments of the present invention, the limiting channel is a polygonal hole, and the vertical length of the polygonal hole > the horizontal length of the polygonal hole; or, the limiting channel is an irregular-shaped hole, and the vertical length of the irregular-shaped hole > the horizontal length of the irregular-shaped hole.

[0042] From Figure 3 It can be seen that the fastener 4 of this embodiment includes a screw. The screw sequentially passes through the fusing component and the stop plate 5 and is threadedly connected to the main body 1. Specifically: through holes are respectively arranged on the first fusing part 422, the second fusing part 423, and the stop plate 5, and a threaded hole is arranged on the main body 1. After the screw sequentially passes through the through holes on the first fusing part 422, the through holes on the second fusing part 423, and the through holes on the stop plate 5, it is fixedly connected to the threaded hole on the main body 1. In other embodiments of the present invention, the fastener includes a bolt and a nut, and the bolt sequentially passes through the fusing component, the stop plate, and the main body and is threadedly connected to the nut; or, the fastener includes a bolt and a nut, and the bolt sequentially passes through the stop plate, the main body, and the fusing component and is threadedly connected to the nut.

[0043] In this embodiment, the fusing piece 42 can be made of one or more of fusible solders such as bismuth-based, indium-based, tin-based, cadmium-based, zinc-based, and lead-based.

[0044] Embodiment Two

[0045] The difference from the first embodiment is that in this embodiment, the structure of the fusing component is improved.

[0046] See Figure 7 , in this embodiment, the fusing component includes at least one fusing piece 42 and at least one retaining ring 43. The retaining ring 43 is made of fusible solder or metal, and the retaining ring 43 is clamped between the first fusing portion 422 and the second fusing portion 423 of the fusing piece 42. When the retaining ring 43 is made of metal, the retaining ring 43 will not be melted. When the retaining ring is made of fusible solder, the retaining ring 43 and the fusing piece 42 will be melted simultaneously. With such a design, the anti-deformation ability of the fusing piece 42 will be significantly enhanced, and the fire check valve will prevent automatic failure in a low-temperature environment.

[0047] In this embodiment, in addition to being clamped between the first fusing portion 422 and the second fusing portion 423 of the fusing piece 42, the retaining ring 43 of this embodiment can also be clamped between two adjacent fusing pieces 42.

[0048] Embodiment Three

[0049] The difference from the first embodiment is that in this embodiment, the structure of the fusing component is improved.

[0050] See Figure 8 , in this embodiment, the fusing component includes at least one fusing ring 43. The fusing ring 43 is provided with a mounting hole, and the fusing ring 43 is sleeved on the fastener 41 and used to control the axial movement range of the retaining plate 5 on the fastener 41.

[0051] Embodiment Four

[0052] The difference from the first embodiment is that in this embodiment, the structure of the fusing component is improved.

[0053] See Figure 10, in this embodiment, the fusing component includes a first metal plate 441, a second metal plate 442, and a solder 443 for connecting the first metal plate 441 and the second metal plate 442. The first metal plate 441 and the second metal plate 442 are respectively arranged on the fastener 41. The gap between the first metal plate 441 and the second metal plate 442 in the axial direction of the fastener 41 is the range of the axial movement of the stop plate 5 on the fastener 41. Specifically: both the first metal plate 441 and the second metal plate 442 are L-shaped. The first metal plate 441 includes a first connecting portion 4411 and a first welding portion 4412 formed by bending the first connecting portion 4411. The second metal plate 442 includes a second connecting portion 4421 and a second welding portion 4422 formed by bending the second connecting portion 4421. The first welding portion 4421 and the second welding portion 4422 are connected into one body by the solder 443. After the first welding portion 4412 and the second welding portion 4422 are connected into one body by the solder 443, the gap between the first connecting portion 4411 and the second connecting portion 4412 is the range of the axial movement of the stop plate 5 on the fastener 41. The advantage of the L-shaped first metal plate 441 and the L-shaped second metal plate 442 is that they can cover the head of the fastener 41, that is, the head of the screw or the head of the bolt, and reduce the probability of the head of the fastener 41 hitting other components. In other embodiments of the present invention, the first metal plate can be "concave-shaped", and the second metal plate can be "linear-shaped"; or, the first metal plate is "U-shaped", and the second metal plate is "Y-shaped".

[0054] In this embodiment, the service life of the fusing component is increased by changing the thrust of the stop plate 5 acting on the fusing component.

[0055] In this embodiment, a first avoidance hole 4413 for avoiding the fastener 41 is provided on the first connecting portion 4411, and a second avoidance hole 4423 for avoiding the fastener 41 is provided on the second connecting portion 4421. The aperture of the first avoidance hole 4413 > the aperture of the second avoidance hole 4423, and the first connecting portion 4411 can abut against the stop plate 5. This structure facilitates the rotation of the stop plate 5 relative to the first avoidance hole 4413.

[0056] As described above, only the specific embodiments of the present invention are shown, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that the present invention includes but is not limited to the content described in the drawings and the above specific embodiments. Any modification that does not deviate from the functional and structural principles of the present invention will be included in the scope of the claims.

Claims

1. Fire prevention check valve, comprising a body, a valve disc, a connecting rod, an elastic element and a paddle. An exhaust port is provided on the body. The connecting rod connects the valve disc and the body and is used to drive the valve disc to close the exhaust port. The paddle is rotatably arranged on the body. One end of the elastic element is arranged on the body, and the other end of the elastic element is arranged on the paddle and is used to drive the paddle to rotate relative to the body. It is characterized in that, It further includes a temperature sensing mechanism and a stop plate. The stop plate is clamped between the temperature sensing mechanism and the body. A rotation stopping portion is provided on the stop plate. When the stop plate is clamped between the temperature sensing mechanism and the body, the rotation stopping portion is arranged on the dial to prevent the dial from rotating relative to the body. After the temperature sensing mechanism operates, the stop plate moves relative to the body and separates the rotation stopping portion from the dial; A clamping portion is further provided on the stop plate. The clamping portion and the rotation stopping portion are arranged on the same side of the stop plate. A limiting channel is provided on the stop plate.

2. The fire prevention check valve according to claim 1, characterized in that, The body includes a valve body, a valve seat and a fixing plate. The connecting rod, the dial and the fixing plate are arranged on the valve seat. The valve seat is arranged on the valve body. The stop plate is clamped between the temperature sensing mechanism and the fixing plate; or, the body includes a valve body and a valve seat. The connecting rod and the dial are arranged on the valve seat. The valve seat is arranged on the valve body. The stop plate is clamped between the temperature sensing mechanism and the valve seat; or, the body includes a valve body and a fixing plate. The connecting rod, the dial and the fixing plate are arranged on the valve body. The stop plate is clamped between the temperature sensing mechanism and the fixing plate; or, the body includes a valve body. The connecting rod and the dial are arranged on the valve body. The stop plate is clamped between the temperature sensing mechanism and the valve body.

3. The fire prevention check valve according to claim 2, characterized in that, The fire check valve further includes a first bolt and a first nut. The first bolt passes through the fixing plate, one side of the valve seat, the connecting rod and the other side of the valve seat and is threadedly connected to the first nut.

4. The fire prevention check valve according to claim 1, characterized in that, The temperature sensing mechanism includes a fastener and a fusing assembly. The fastener is arranged on the body. The fusing assembly is arranged on the fastener. The stop plate is clamped between the fusing assembly and the body. After the fusing assembly operates, the stop plate moves axially along the fastener and separates the rotation stopping portion from the dial.

5. The fire prevention check valve according to claim 4, characterized in that, The fuse assembly includes a first metal plate, a second metal plate and a solder for connecting the first metal plate and the second metal plate, the first metal plate and the second metal plate are respectively arranged on the fastener, and the gap between the first metal plate and the second metal plate in the axial direction of the fastener is the range of axial movement of the stop plate on the fastener; the first metal plate and the second metal plate are both L-shaped, the first metal plate includes a first connecting portion and a first welding portion formed by bending the first connecting portion, the second metal plate includes a second connecting portion and a second welding portion formed by bending the second connecting portion, the first welding portion and the second welding portion are connected as a whole through the solder, and after the first welding portion and the second welding portion are connected as a whole through the solder, the gap between the first connecting portion and the second connecting portion is the range of axial movement of the stop plate on the fastener; the first connecting portion is provided with a first avoidance hole for avoiding the fastener, and the second connecting portion is provided with a second avoidance hole for avoiding the fastener, the aperture of the first avoidance hole is greater than the aperture of the second avoidance hole, and the first connecting portion can be abutted against the stop plate.

6. The fire prevention check valve according to claim 4, characterized in that, The fuse assembly includes at least one fuse piece, which includes a first fuse part, a second fuse part and a third fuse part for controlling the axial movement range of the stop plate on the fastener, the first fuse part and the second fuse part are respectively arranged on the fastener, and the third fuse part is used to connect the first fuse part and the second fuse part; the fuse assembly also includes a stop ring, which is made of fusible solder or metal, and the stop ring is clamped between the first fuse part and the second fuse part; or, the stop ring is clamped between two adjacent fuse pieces.

7. The fire prevention check valve according to claim 4, characterized in that, The fuse assembly includes at least one fuse ring, a mounting hole is provided on the fuse ring, the fuse ring is sleeved on the fastener and is used to control the axial movement range of the stop plate on the fastener.

8. The fire prevention check valve according to claim 1, characterized in that, After the temperature sensing mechanism is actuated, the stop plate moves axially along the limiting channel and separates from the paddle.

9. The fire prevention check valve according to claim 8, characterized in that, The limiting channel is an elliptical hole, the long axis segment of the elliptical hole is vertically arranged, and the short axis segment of the elliptical hole is horizontally arranged; or, the limiting channel is a polygonal hole, the vertical length of the polygonal hole is greater than the horizontal length of the polygonal hole; or, the limiting channel is an irregularly shaped hole, the vertical length of the irregularly shaped hole is greater than the horizontal length of the irregularly shaped hole.

10. The fire prevention check valve according to claim 4, characterized in that, The fastener includes a screw, which passes through the fuse assembly and the stop plate in sequence and is threadedly connected to the main body; or, the fastener includes a second bolt and a second nut, which passes through the fuse assembly, the stop plate and the main body in sequence and is threadedly connected to the second nut; or, the fastener includes a second bolt and a second nut, which passes through the stop plate, the main body and the fuse assembly in sequence and is threadedly connected to the second nut.

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