阅读说明：本技术 熔断机构及防火止回阀 (Fusing mechanism and fireproof check valve ) 是由 王启定 曹正祥 于 2018-08-19 设计创作，主要内容包括：本发明涉及一种熔断机构及防火止回阀,解决了熔断机构使用寿命短的问题。熔断机构,包括至少一个用于阻止锁紧杆相对阀体轴向运动的熔断单元,每个熔断单元上设有匹配锁紧杆的安装孔。(The invention relates to a fusing mechanism and a fireproof check valve, and solves the problem of short service life of the fusing mechanism. The fusing mechanism comprises at least one fusing unit for preventing the locking rod from moving axially relative to the valve body, and each fusing unit is provided with a mounting hole matched with the locking rod.)

1. The fusing mechanism is characterized by comprising at least one fusing unit for preventing the locking rod from moving axially relative to the valve body, and each fusing unit is provided with a mounting hole matched with the locking rod.

2. The fuse mechanism of claim 1, wherein each fuse unit includes a solder ring having a mounting hole; or each fusing unit comprises an arc-shaped brazing filler metal section, a mounting hole is formed in the arc-shaped brazing filler metal section, and a gap communicated with the mounting hole is formed between the head end and the tail end of the arc-shaped brazing filler metal section; or each fusing unit comprises at least two arc-shaped brazing filler metal sections, and the at least two arc-shaped brazing filler metal sections are spliced to form the mounting hole.

3. The fuse mechanism of claim 2, wherein the axial dimension of the solder ring is 10mm or less; the mounting hole is a through hole with a smooth inner wall.

4. The fireproof check valve comprises a valve body with an exhaust port, a valve plate and a connecting mechanism, wherein the connecting mechanism is connected with the valve plate and used for driving the valve plate to close the exhaust port, and is characterized by further comprising a locking mechanism, a shifting mechanism, an elastic element and a fusing mechanism, the locking mechanism and the shifting mechanism are arranged on the valve body, the fusing mechanism is the fusing mechanism in any one of claims 1 to 3, the locking mechanism is provided with a locking position and an unlocking position, when the locking mechanism is located at the locking position, at least one fusing unit is clamped between the locking mechanism and the valve body, after the at least one fusing unit acts, the elastic element drives the locking mechanism to move from the locking position to the unlocking position through the shifting mechanism, when the locking mechanism is located at the unlocking position, the valve plate closes the exhaust port.

5. The fire resistant check valve of claim 4, wherein the locking mechanism includes a locking lever disposed on the valve body for preventing movement of the toggle mechanism relative to the valve body, the locking lever extending through a mounting hole in the fuse unit.

6. The fire resistant check valve of claim 5 wherein said locking member includes a screw having a head portion that abuts said fuse unit.

7. The fire check valve of claim 5, further comprising a temperature sensing mechanism, wherein one end of the temperature sensing mechanism is fixedly connected to the rod portion of the locking rod, and when at least one fuse unit is clamped between the head portion of the locking rod and the valve body, the other end of the temperature sensing mechanism is in snap-fit connection with the toggle mechanism to prevent the elastic element from driving the toggle mechanism to move relative to the valve body.

8. The fire protection check valve of claim 7, wherein the temperature sensing mechanism comprises a first metal plate, a second metal plate and a brazing material for connecting the first metal plate and the second metal plate, the first metal plate is provided with a threaded hole for engaging with the locking rod, the second metal plate is provided with a rotation stop at its end, and when the locking mechanism is located at the locking position, the rotation stop is engaged with the toggle mechanism to prevent the elastic element from driving the toggle mechanism to move relative to the valve body.

9. A fireproof check valve as claimed in claim 8, wherein the first metal plate and/or the second metal plate is provided with a receiving cavity, and the brazing material is melted and then placed in the receiving cavity.

10. The fire check valve of claim 4, further comprising a securing mechanism movably disposed on said valve body, wherein a wall of the vent is captured between said securing mechanism and said valve body.

Technical Field

The invention relates to a fusing mechanism and a fireproof check valve.

Background

The existing fireproof check valve (the specific structure of which refers to the invention patent with the application number of 201610651149.5) comprises a valve seat, a shifting rod, a fusing mechanism and a torsion spring, wherein the fusing mechanism comprises a first metal plate, a second metal plate and a fusible solder for connecting the first metal plate and the second metal plate, the shifting rod and the second metal plate are rotatably connected with the valve seat, one torsion arm of the torsion spring is connected with the valve seat, the other torsion arm of the torsion spring is connected with the shifting rod and drives the shifting rod to abut against the first metal plate, a limiting part is arranged on the valve seat, when the other torsion arm of the torsion spring is connected with the shifting rod and drives the shifting rod to abut against the first metal plate, and the first metal plate and the second metal plate are connected through the fusible solder, the second metal plate abuts against the limiting part, so that the fusing mechanism is clamped between the shifting rod and the limiting part.

When the fusing mechanism is clamped between the shifting lever and the limiting part, the shifting lever applies a first acting force to the first metal plate, the limiting part applies a second acting force to the second metal plate, the first acting force and the second acting force are the same in size and opposite in direction, in other words, the first acting force keeps the upward movement trend of the first metal plate relative to the fusible solder, the second acting force keeps the downward movement trend of the second metal plate relative to the fusible solder, and the position where the shifting lever abuts against the first metal plate and the position where the limiting part abuts against the second metal plate are staggered with each other, so that the position where the fusible solder is abutted against by the torsional force for a long time.

The first metal plate (or the second metal plate) can be separated from the fusible solder due to the long-term action of the torsional force on the fusible solder, which means that the fusing mechanism can automatically lose efficacy after the fireproof check valve is used for a period of time in a normal temperature environment. After the fusing mechanism automatically fails, the torsion spring drives the deflector rod to rotate relative to the valve seat so as to realize that the deflector rod drives the valve plate to close the exhaust port through the connecting rod.

Disclosure of Invention

The invention aims to provide a fusing mechanism and a fireproof check valve to prolong the service life of the fusing mechanism.

In order to solve the above problems, the present invention provides the following technical solutions: the fusing mechanism comprises at least one fusing unit for preventing the locking rod from moving axially relative to the valve body, and each fusing unit is provided with a mounting hole matched with the locking rod.

Further, each fusing unit includes a solder ring having a mounting hole; or each fusing unit comprises an arc-shaped brazing filler metal section, a mounting hole is formed in the arc-shaped brazing filler metal section, and a gap communicated with the mounting hole is formed between the head end and the tail end of the arc-shaped brazing filler metal section; or each fusing unit comprises at least two arc-shaped brazing filler metal sections, and the at least two arc-shaped brazing filler metal sections are spliced to form the mounting hole.

Further, the axial size of the brazing ring is less than or equal to 10 mm; the mounting hole is a through hole with a smooth inner wall.

The fireproof check valve comprises a valve body with an exhaust port, a valve plate and a connecting mechanism, wherein the connecting mechanism is connected with the valve plate and used for driving the valve plate to close the exhaust port, the fireproof check valve further comprises a locking mechanism, a shifting mechanism, an elastic element and a fusing mechanism, the locking mechanism and the shifting mechanism are arranged on the valve body, the fusing mechanism is the fusing mechanism in any one of the technical schemes, the locking mechanism is provided with a locking position and an unlocking position, when the locking mechanism is located at the locking position, at least one fusing unit is clamped between the locking mechanism and the valve body, after the at least one fusing unit acts, the elastic element drives the locking mechanism to move from the locking position to the unlocking position through the shifting mechanism, and when the locking mechanism is located at the unlocking position, the valve plate closes the exhaust port.

Furthermore, the locking mechanism comprises a locking rod which is arranged on the valve body and used for preventing the toggle mechanism from moving relative to the valve body, and the locking rod penetrates through a mounting hole in the fusing unit.

Further, the locking member includes a screw, and a head of the screw may abut against the fusing unit.

Furthermore, the fire-proof check valve further comprises a temperature sensing mechanism, one end of the temperature sensing mechanism is fixedly connected with the rod part of the locking rod, and when at least one fusing unit is clamped between the head part of the locking rod and the valve body, the other end of the temperature sensing mechanism is in buckle connection with the shifting mechanism so as to prevent the elastic element from driving the shifting mechanism to move relative to the valve body.

Furthermore, the temperature sensing mechanism comprises a first metal plate, a second metal plate and a brazing filler metal piece used for connecting the first metal plate with the second metal plate, a threaded hole matched with the locking rod is formed in the first metal plate, a rotation stopping part is arranged at the tail end of the second metal plate, and when the locking mechanism is located at a locking position, the rotation stopping part is connected with the shifting mechanism in a clamped mode to prevent the elastic element from driving the shifting mechanism to move relative to the valve body.

Furthermore, the first metal plate and/or the second metal plate are/is provided with an accommodating cavity, and the brazing filler metal piece can be arranged in the accommodating cavity after being melted.

Furthermore, the fireproof check valve also comprises a fixing mechanism movably arranged on the valve body, and the wall of the exhaust passage can be clamped between the fixing mechanism and the valve body.

The invention has the beneficial effects that:

1. in the present invention, the fusing mechanism includes a fusing unit. By the design, the structure of the fusing mechanism is simplified, and the manufacturing cost of the fusing mechanism is reduced.

2. In the invention, each fusing unit is provided with a mounting hole, and the fusing unit is sleeved on the locking rod. By the design, the fusing unit is prevented from being automatically separated from the locking rod, so that the service life of the fusing unit is prolonged.

3. In the invention, the fireproof check valve comprises a locking mechanism and a fusing mechanism, and the fusing mechanism is clamped between the locking mechanism and the valve body. Among the prior art, the fire prevention check valve need just can install fusing mechanism on the disk seat through three step in the manufacture: step one, a fusing mechanism is arranged on a valve seat through a locking rod; secondly, one side of the fusing mechanism is abutted against the limiting part; and thirdly, the other side of the fusing mechanism is abutted against the deflector rod. In the invention, the fusing mechanism is arranged on the locking mechanism firstly, then the fusing mechanism is clamped between the locking mechanism and the valve body, and the fusing mechanism completes the installation steps through the two steps. So design, through the mounted position, the mounting structure who changes the fuse-link mechanism to the realization has simplified the installation procedure of fire prevention check valve, has improved the production efficiency of fire prevention check valve, has reduced the manufacturing cost of fire prevention check valve.

4. According to the invention, the locking mechanism is provided with a locking position and an unlocking position, after the fusing mechanism acts, the elastic element drives the locking mechanism to move from the locking position to the unlocking position through the toggle mechanism, and after the fusing mechanisms with different specifications are replaced by the fireproof check valve, the locking position of the locking mechanism is changed. By the design, the position precision requirement of the locking mechanism can be properly reduced, so that the manufacturing cost of the fireproof check valve is reduced.

5. According to the invention, when the fusing mechanism is clamped between the locking mechanism and the valve body, the fusing mechanism is positioned at the outer side of the valve body, and the structure can prevent smoke from entering the exhaust passage when the fireproof check valve catches fire indoors; when the fusing mechanism is clamped between the locking mechanism and the valve body, the fusing mechanism is positioned on the inner side of the valve body, and the structure can prevent smoke from entering the room through the exhaust duct when the fireproof check valve catches fire outdoors; when the fusing mechanism is clamped between the locking mechanism and the valve body, part of the fusing mechanism is positioned on the outer side of the valve body, and the rest of the fusing mechanism is positioned on the inner side of the valve body.

Drawings

FIG. 1 is a perspective view of a fire check valve in a preferred embodiment of the present invention;

FIG. 2 is a bottom view of the fire check valve in the preferred embodiment of the present invention;

FIG. 3 is a cross-sectional view taken at A-A of FIG. 2;

FIG. 4 is a cross-sectional view taken at B-B of FIG. 2 (with the locking mechanism in the locked position);

FIG. 5 is a cross-sectional view taken at B-B of FIG. 2 (with the locking mechanism in an unlocked position);

FIG. 6 is a perspective view of the latching mechanism and the fuse mechanism in the preferred embodiment of the present invention;

FIG. 7 is a cross-sectional view of the latching mechanism and the fusing mechanism in a preferred embodiment of the invention;

FIG. 8 is a perspective view of a valve body in a preferred embodiment of the invention;

FIG. 9 is a front view of the toggle mechanism in the preferred embodiment of the present invention;

FIG. 10 is a perspective view of a second valve seat in the preferred embodiment of the present invention;

FIG. 11 is a perspective view of a portion of the fire check valve of the preferred embodiment of the present invention (with the valve plate and attachment mechanism omitted);

FIG. 12 is a perspective view of a portion of the fire check valve in the preferred embodiment of the present invention (with the toggle mechanism omitted);

fig. 13 is a perspective view of a connection mechanism in a preferred embodiment of the invention.

Detailed Description

The technical solutions of the embodiments of the present invention are explained and illustrated below with reference to the drawings of the embodiments of the present invention, but the following embodiments are only preferred embodiments of the present invention, and not all embodiments. Based on the embodiments in the implementation, other embodiments obtained by those skilled in the art without any creative effort belong to the protection scope of the present invention.

Referring to fig. 6 and 7, the fusing mechanism includes at least one fusing unit for preventing the locking lever 4 from moving axially with respect to the valve body 1, and each fusing unit is provided with a mounting hole 511 matching the locking lever 4.

In the present embodiment, each fusing unit includes a solder ring 51 having a mounting hole 511; or each fusing unit comprises an arc-shaped brazing filler metal section, the arc-shaped brazing filler metal section is provided with a mounting hole, and a gap communicated with the mounting hole is formed between the head end and the tail end of the arc-shaped brazing filler metal section; or each fusing unit comprises at least two arc-shaped brazing filler metal sections, and the at least two arc-shaped brazing filler metal sections are spliced to form the mounting hole.

Preferably, the axial dimension of the brazing ring 51 is less than or equal to 10 mm. So designed, the time required for the solder ring 51 to melt at high temperature is shortened.

Preferably, the mounting hole 511 is a through hole with a smooth inner wall. By such a design, the manufacturing cost of the solder ring 51 is reduced, and the time consumed for assembling the solder ring 51 is shortened. Of course, in other embodiments of the present invention, the mounting holes may be threaded holes.

Referring to fig. 2 and 3, the fire-proof check valve includes a valve body 1 having an exhaust port 111, a valve sheet 2, and a connecting mechanism 3, wherein the connecting mechanism 3 is used for connecting the valve sheet 2 with the valve body 1 and driving the valve sheet 2 to close the exhaust port 111.

As can be seen from fig. 3, the valve body 1 of this embodiment has the exhaust passage 11, and the exhaust port 111 is arranged on the exhaust passage 11, and when the exhaust port 111 is closed by the valve plate 2, the exhaust passage 11 is located on both sides of the exhaust port 111, and the flow of the smoke cannot be realized, which means that when the exhaust port 111 is closed by the valve plate 2, the smoke in the user room cannot enter the exhaust passage through the fireproof check valve, and the smoke in the exhaust passage cannot enter the user room through the fireproof check valve. Of course, in the prior art, the valve body may include an annular baffle having exhaust ports, such valve body being devoid of exhaust passages.

The connecting mechanism 3 on the fire-proof check valve has three modes of closing the air outlet 111 through the valve plate 2: 1. as shown in fig. 3, the fireproof check valve includes a second elastic element 8, the second elastic element 8 is one of a second torsion spring, a tension spring and a compression spring, and the second elastic element 8 is used for driving the connecting mechanism 3 to drive the valve plate 1 to move relative to the valve body 1, so as to maintain a tendency that the valve plate 1 closes the exhaust port 111; 2. the valve plate keeps the trend of closing the exhaust port under the action of self gravity; 3. the connecting mechanism is eccentrically arranged to maintain the tendency of the valve plate to close the exhaust port.

Referring to fig. 1, 6 and 11, in this embodiment, the fire check valve further includes a locking mechanism, a toggle mechanism 6, an elastic element and a fusing mechanism, the elastic element is referred to as a first elastic element 7 for easy distinction, the locking mechanism and the toggle mechanism 6 are movably disposed on the valve body 1, the locking mechanism has a locking position and an unlocking position, as shown in fig. 4, when the locking mechanism is located at the locking position, at least one fusing unit is clamped between the locking mechanism and the valve body 1, after the at least one fusing unit is actuated, the first elastic element 7 drives the locking mechanism to move from the locking position to the unlocking position through the toggle mechanism 6, as shown in fig. 5, when the locking mechanism is located at the unlocking position, the valve sheet 2 closes the exhaust port 111.

In this embodiment, after the at least one fusing unit is actuated, the toggle mechanism 6 drives the valve plate 2 to close the air outlet 111 through the connecting mechanism 3. So design, toggle mechanism 6 does not with valve block 2 direct contact to avoid valve block 2 to take place to warp under toggle mechanism 6's striking. Of course, in other embodiments of the present invention, after the at least one fusing unit is activated, the toggle mechanism may directly drive the valve plate to close the vent.

Referring to fig. 8, the valve body 1 is provided with a guide channel for guiding the movement direction of the locking mechanism, at least part of the locking mechanism is arranged in the guide channel, and when the locking mechanism is located at the locking position or the unlocking position, at least one end surface of the locking mechanism is located outside the guide channel. Due to the design, the locking mechanism can be conveniently taken out of the guide channel, the fusing mechanism can be conveniently arranged on the outer side of the valve body 1, and the temperature sensing mechanism 52 is arranged on the inner side of the valve body 1. In other embodiments of the present invention, the locking mechanism may be welded to the inside of the valve body, and a space for holding the temperature sensing mechanism is left between the locking mechanism and the side wall of the valve body.

Preferably, the valve body 1 includes first blast pipe 101, second blast pipe 103 and can offset the annular baffle 102 with valve block 2, and first blast pipe 101 is connected through annular baffle 102 with second blast pipe 103, and annular baffle 102 encloses into gas vent 111, is equipped with guiding hole 12 on the annular baffle 102, and guiding hole 12 does the guide way, locking mechanism are including setting up the check lock lever 4 that is used for preventing the relative valve body motion of toggle mechanism on the valve body 1, and behind mounting hole 511 and the guiding hole 12 on the fuse unit, check lock lever 4 run through in proper order, with temperature sensing mechanism 52 fixed connection. So design, temperature sensing mechanism 5 can set up in the valve body 1 outside, also can set up in the valve body 1 inboard, and this just means, and the fire prevention check valve just can realize indoor, outdoor dual smoke insulation through setting up one set of toggle mechanism 6. In addition, in other embodiments of the present invention, the guide channel may also be disposed at other positions of the valve body by changing the shape, for example, a guide seat is disposed inside the valve body, a guide groove is disposed on the guide seat, the top of the guide groove is open, two opposite openings are disposed on the side wall of the guide groove, and the guide groove is a guide channel; alternatively, the guide holes are provided on the mounting panel 104.

In this embodiment, when the fuse mechanism is held between the latch mechanism and the valve body 1, the fuse mechanism is located outside the valve body 1, and the temperature sensing mechanism 52 is located inside the valve body 1. So design realizes that the fire prevention check valve carries out indoor, outdoor dual smoke insulation. Of course, in other embodiments of the invention, the fuse mechanism is only located inside the valve body when it is clamped between the locking mechanism and the valve body.

Referring to fig. 6, the locking rod 4 has a fixing portion at one end, the fuse mechanism is clamped between the fixing portion and the ring-shaped baffle plate 102, as can be seen from fig. 7, the locking rod includes a screw, the axial length of the screw rod portion 42 is greater than the sum of the lengths of the solder ring 51 and the guide hole 12, the head portion 41 of the screw is a fixing portion capable of abutting against the fuse unit, and when the screw rod portion 42 penetrates through the mounting hole 511, at least one solder ring 51 is clamped between the head portion 41 of the screw and the ring-shaped baffle plate 102. In other embodiments of the invention, the locking mechanism comprises a bolt and a nut, and the bolt is fixedly connected with the nut after penetrating through the brazing ring and the first metal plate.

In this embodiment, one solder ring 51 is clamped between the head 41 of the screw and the ring baffle 102, but in other embodiments of the invention, the number of solder rings clamped between the fixing portion and the ring baffle may be adjusted according to actual requirements.

Referring to fig. 6, the fire check valve further includes a temperature sensing mechanism 52, one end of the temperature sensing mechanism 52 is fixedly connected to the rod portion of the locking rod 4, when at least one fusing unit is clamped between the head portion of the locking rod 4 and the valve body 1, the other end of the temperature sensing mechanism 52 is connected to the toggle mechanism 6 in a snap-fit manner, so as to prevent the first elastic element 7 from driving the toggle mechanism 6 to move relative to the valve body 1, specifically: the temperature sensing mechanism 52 further includes a first metal plate 521, a second metal plate 523 and a brazing filler metal member 522 for connecting the first metal plate 521 and the second metal plate 523, the first metal plate 521 is detachably disposed at the other end of the locking rod 4, the end of the second metal plate 523 is provided with a rotation stopping portion 5231, and when the locking mechanism is located at the locking position, the rotation stopping portion 5231 is in clamping connection with the toggle mechanism 6 to prevent the first elastic element 7 from driving the toggle mechanism 6 to move relative to the valve body 1. In other embodiments of the present invention, the temperature sensing mechanism further includes a solder rod, one end of the solder rod is clamped between the locking rod and the valve body, and the other end of the solder rod is provided with a rotation stopping portion, when the locking mechanism is located at the locking position, the rotation stopping portion is clamped with the toggle mechanism to prevent the first elastic element from driving the toggle mechanism to move relative to the valve body. When a fire breaks out indoors, the brazing filler metal ring 51 is melted, and the locking rod 4 moves axially from the locking position to the unlocking position, so that the valve plate 2 closes the exhaust port 111. When a fire breaks out outdoors, the brazing member 522 is melted and the first metal plate 521 is separated from the second metal plate 523 to allow the valve sheet 2 to close the discharge port 111.

Referring to fig. 7, the rotation stopper 5231 has a height H1, and the axial length of the solder ring 51 is H3, H1 < H3. So designed, after the solder ring 51 is melted, the range of the axial movement of the locking mechanism relative to the valve body 1 is > H1, which means that the rotation stop 5231 will be disengaged from the toggle mechanism 6 when the locking mechanism is moved from the locked position to the unlocked position.

In this embodiment, the solder ring 51 and the solder member 522 may be one or more of a solder material such as sapphire, indium, tin, cadmium, zinc, and lead.

It is clear from the above description that: the fusing mechanism action includes a melting action of the solder ring 51. In other embodiments of the present invention, the fuse mechanism may include a memory metal, the memory metal is clamped between the locking mechanism and the valve body, after the memory metal deforms (the deformation includes but is not limited to the memory metal bending under the action of pressure, and the thickness of the memory metal changing under the action of pressure), the first elastic element drives the locking mechanism to move from the locking position to the unlocking position through the toggle mechanism, and when the locking mechanism is located at the unlocking position, the valve plate closes the exhaust port.

Preferably, the first metal plate 521 and/or the second metal plate 523 are provided with an accommodating cavity, the accommodating cavity is generally an accommodating hole (which may be an accommodating groove or a notch) provided on the first metal plate 521 and/or the second metal plate 523, and the brazing filler material 522 may be disposed in the accommodating hole after being melted. By such design, the connection strength between the first metal plate 521 and the second metal plate 523 is increased.

In this embodiment, the first metal plate 521 can be detachably disposed at the other end of the locking rod 4 by means of clamping, screwing, hinging, and the like, preferably, the first metal plate 521 is provided with a fixing section 5211, and the fixing section 5211 is provided with a threaded hole matching with the rod portion 42 of the screw, so that the rod portion 42 of the screw penetrates through the threaded hole to fixedly connect the rod portion 42 of the screw with the first metal plate 521.

Referring to fig. 3 and 13, the connecting mechanism 3 includes a connecting rod 31, a lower end of the connecting rod 31 is rotatably connected to the valve body 1, and an upper end of the connecting rod 31 is movably connected to the valve plate 2. In addition, in other embodiments of the invention, the lower end of the connecting rod can slide along the slide rail on the valve body to realize that the valve plate closes the exhaust port, and the upper end of the connecting rod is rotatably connected with the valve plate.

In this embodiment, the fireproof check valve further includes a bolt 91 and a nut 92, the bolt 91 sequentially penetrates through the connecting rod 31 and the valve plate 2 and then is fixedly connected with the nut 92, and when the bolt 91 sequentially penetrates through the connecting rod 31 and the valve plate 2 and then is fixedly connected with the nut 92, the gap between the bolt head and the nut 92 is larger than the sum of the thickness of the valve plate 2 and the thickness of the upper bottom plate 301 of the connecting rod 31.

Preferably, the bolt 91 is a step bolt, the step bolt sequentially comprises a bolt head, a platform stage and a screw section along the axial direction of the step bolt, and the valve plate 2 is sleeved on the platform stage.

In this embodiment, the connecting mechanism 3 further includes a rotating shaft 10, and the connecting rod 31 is rotatably connected to the second valve seat 107 through the rotating shaft 10. In other embodiments of the present invention, one of the connecting rod and the second valve seat is provided with a rotating shaft, and the other is provided with a shaft hole matched with the rotating shaft.

In this embodiment, the fire check valve further includes a fixing mechanism movably disposed on the valve body 1, the wall of the exhaust passage may be clamped between the fixing mechanism and the valve body 1, the fixing mechanism includes a third torsion spring, and the wall of the exhaust passage is clamped between a torsion arm of the third torsion spring and the inner wall of the valve body 1. Of course, in other embodiments of the present invention, the fixing mechanism may be other adjusting mechanisms, and the adjusting mechanism includes an operating rod and a clamping block, and the operating rod is used for adjusting the spacing distance between the clamping block and the valve body.

Referring to fig. 9 and 11, the toggle mechanism 6 includes a toggle lever transversely disposed on the valve body 1, an adapter portion is disposed at an edge position of the toggle lever, and a middle position of the toggle lever protrudes outward. In other embodiments of the invention, the toggle mechanism arc, the rotating rod, and the fastener for connecting the arc and the rotating rod.

Referring to fig. 9, the shift lever is provided with an accommodating cavity for limiting the installation position of the temperature sensing element 5, specifically: the outer side wall of the shift lever is provided with a positioning groove 611, the positioning groove 611 is the accommodating cavity, and when the rotation stop portion 5231 is engaged with the shift lever, the second metal plate 523 is located in the positioning groove 611. By the design, the position of the second metal plate 523 clamped on the toggle mechanism 6 is effectively limited. In other embodiments of the present invention, the driving lever is provided with a positioning hole, the positioning hole is the accommodating cavity, and the second metal plate can be inserted into the positioning hole.

Preferably, the depth of the positioning groove 611 is H2, and H2 > the thickness of the second metal plate 523.

As can be seen from fig. 9, the middle position of the shift lever is provided with an arc-shaped section 61 for connecting the adapter, and the outer side wall of the arc-shaped section is arc-shaped. Due to the design, the interference between the deflector rod and the valve body 1 in the movement process is avoided.

In this embodiment, the adaptor portion includes a rotating shaft section 62 and a clamping section 63, and the first elastic element 7 is a first torsion spring sleeved on the clamping section 63. Of course, in other embodiments of the present invention, the adapter portion may only include a shaft section, and the first torsion spring is sleeved on the shaft section; alternatively, the adapter part only comprises a shaft hole section, and the first torsion spring is sleeved on the valve body.

Referring to fig. 12 and 13, the connecting rod 31 includes a first side plate 302, a second side plate 303, and a bottom plate 301 for connecting the first side plate 302 and the second side plate 303, the first side plate 302, the bottom plate 301, and the second side plate 303 enclose an accommodating cavity 311, a first inclined section 3021 is disposed on the first side plate 302, and a second inclined section 3031 is disposed on the second side plate 303, after the temperature sensing mechanism 5 operates, the toggle mechanism 6 slides forward along the first inclined section 3021 and/or the second inclined section 3031, so that the connecting rod 31 closes the exhaust port 111 through the valve sheet 2. So designed, the direction of movement of the toggle mechanism 6 is defined.

In this embodiment, the first inclined section 3021 and/or the second inclined section 3031 are provided with at least one protrusion for preventing the shift lever from sliding along the reverse direction. By the design, the valve plate 2 is effectively prevented from opening the exhaust port 111 under the action of high-temperature airflow.

Preferably, the protrusion is a pawl, and thus the shift lever cannot slide reversely. In other embodiments of the invention, the projection may be a boss.

Referring to fig. 3 and 10, a first valve seat 106 and a second valve seat 107 are provided on the valve body 1, the first valve seat 106 is connected with the valve body 1 by a first fixing screw 20, and the second valve seat 107 is connected with the valve body 1 by a second fixing screw 30. In other embodiments of the invention, the first valve seat is connected with the valve body in a buckling manner, and the second valve seat is connected with the valve body into a whole by welding.

While the present invention has been described with reference to the preferred embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims. Any modification which does not depart from the functional and structural principles of the present invention is intended to be included within the scope of the claims.