阅读说明：本技术 一种用于吸油烟机的防火阀 (Fire-proof valve for range hood ) 是由 张青松 于 2019-09-06 设计创作，主要内容包括：本发明涉及一种用于吸油烟机的防火阀,包括阀体,其内包括有互成夹角并连通的第一流道和第二流道,其中第一流道的端部为进烟口,用来与吸油烟机的出风口相流体连通,第二流道的端部为排烟口,用来与公共烟道相流体连通；其特征在于：所述第一流道和第二流道的其中之一具有自两者连通处反向延长的延伸段；并且,还包括有：阀芯,以活塞方式能滑动地设置在所述的延伸段中；驱动机构,用来驱动所述的阀芯来回滑动,使阀芯封堵或打开所述的连通处。阀芯在烟道起火状态下能够可靠封堵住连通处,达到阻断油烟倒灌的目的。(The invention relates to a fire damper for a range hood, which comprises a valve body, wherein a first flow passage and a second flow passage which form an included angle with each other and are communicated are arranged in the valve body, the end part of the first flow passage is a smoke inlet and is used for being in fluid communication with an air outlet of the range hood, and the end part of the second flow passage is a smoke outlet and is used for being in fluid communication with a common flue; the method is characterized in that: one of the first flow passage and the second flow passage is provided with an extension section which is reversely prolonged from the communication part of the first flow passage and the second flow passage; and, also include: a valve core which is arranged in the extension section in a piston mode in a sliding mode; and the driving mechanism is used for driving the valve core to slide back and forth so as to enable the valve core to block or open the communication position. The valve core can reliably block the communication position when the flue is on fire, so as to achieve the purpose of blocking the oil smoke from flowing backwards.)

1. A fire damper for a range hood, comprising:

the valve body (1) comprises a first flow channel (111) and a second flow channel (112) which form an included angle and are communicated with each other, wherein the end part of the first flow channel (111) is a smoke inlet (111a) and is used for being in fluid communication with an air outlet of the range hood, and the end part of the second flow channel (112) is a smoke outlet (112b) and is used for being in fluid communication with a common flue;

the method is characterized in that:

one of the first flow passage (111) and the second flow passage (112) is provided with an extension section (13) which is reversely prolonged from a communication part (113) of the first flow passage and the second flow passage; and, also include:

a valve core (3) which is arranged in the extension section (13) in a piston mode in a sliding mode;

and the driving mechanism (4) is used for driving the valve core (3) to slide back and forth so as to enable the valve core (3) to block or open the communication part (113).

2. The fire damper of claim 1, wherein: the extension section (13) is formed by extending the second flow passage (112) in the opposite direction.

3. The fire damper of claim 2, wherein: the valve body (1) is provided with a smoke inlet pipe (11a) and a smoke outlet pipe (11b) which are communicated with each other and have T-shaped sections, a flow passage in the smoke inlet pipe (11a) is a first flow passage (111), and a flow passage in the smoke outlet pipe (11b) is a second flow passage (112); the valve core (3) is cylindrical, the outer diameter of the valve core is matched with the inner diameter of the smoke exhaust pipe (11b), and the length of the valve core (3) along the axial direction of the valve core is not less than the inner diameter of the smoke inlet pipe (11a) at the communication part (113).

4. A fire damper as claimed in claim 3, wherein: the outer side of the tail end of the extension section (13) is provided with a first chamber (12a) extending along the axial direction of the smoke inlet pipe (11a), a second chamber (12b) is arranged between the first chamber (12a) and the smoke inlet pipe (11a), and the driving mechanism (4) is partially positioned in the first chamber (12a) and the second chamber (12 b).

5. The fire damper of claim 4, wherein: the driving mechanism comprises

The first transmission rod (41) is partially positioned in the second chamber (12b), one end of the first transmission rod penetrates into the first flow passage (111) of the smoke inlet pipe (11a), and a first transmission gear (421) is fixedly penetrated on the first transmission rod (41);

a second transmission rod (422), which is partially positioned in the second chamber (12b), is parallel to the first transmission rod (41), penetrates a second transmission gear (423) meshed with the first transmission gear (421), and penetrates a third transmission gear (424) with one end penetrating the second chamber (12b), entering the first chamber (12 a); and

and the third transmission rod (43) is used for driving the valve core (3) to move back and forth towards the direction of the communication part (113), is parallel to the second transmission rod (422), is partially positioned in the first chamber (12a), a first end of the third transmission rod (43) positioned in the first chamber (12a) is fixedly penetrated with a fourth transmission gear (425) meshed with the third transmission gear (424), and a second end positioned in the extension section (13) is in threaded connection with an inner shaft hole (31) formed in the valve core (3) along the axial direction.

6. The fire damper of claim 5, wherein: the first transmission rod (41) is provided with an energy storage elastic piece (6) which enables the first transmission rod (41) to rotate towards the opposite rotation direction so as to enable the valve core (3) to always have the trend of moving towards the smoke exhaust port (112b), and the energy storage elastic piece (6) is in an energy storage state under the state that the valve core (3) is positioned in the extension section (13).

7. The fire damper of claim 6, wherein: one end of the first transmission rod (41) located in the first flow passage (111) is fixedly provided with a fusing ring (5) in a penetrating manner, and the first transmission rod (41) is fixed on the side wall of the smoke inlet pipe (11a) through the fusing ring (5), namely, when the fusing ring (5) is in a fusing state, the smoke inlet pipe (11a) and the first transmission rod (41) are in a separation state.

8. The fire damper of claim 7, wherein: energy storage elastic component (6) are for setting up the torsional spring of first transfer line (41), the stiff end of torsional spring with the wallboard of second chamber (12b) links to each other, install application of force end (61) of torsional spring on first transfer line (41).

9. A fire damper as claimed in claim 3, wherein: and a contraction section (110) for limiting the valve core (3) to continuously move towards the smoke outlet (112b) is arranged at the position, adjacent to the communication part (113), of the inner side wall of the smoke exhaust pipe (11 b).

10. The fire damper of claim 9, wherein: the outer peripheral wall of one end of the valve core (3) facing the smoke exhaust port (112b) is provided with an annular inclined surface (32) extending in an inclined mode towards the axial direction of the valve core (3), and correspondingly, the end portion, close to the communication portion (113), of the contraction section (110) is provided with an inclined pipe orifice (1101) matched with the annular inclined surface (32) of the valve core (3).

Technical Field

The invention belongs to the technical field of range hoods, and particularly relates to a fireproof valve for a range hood.

Background

At present, a common flue is generally used in a household building, and oil smoke exhausted by a range hood of each household enters the common flue from the range hood and then is exhausted from the upper part of the house.

Like the fire damper for a range hood of the chinese utility model patent with patent number CN201820857187.0 (publication number CN208535256U) previously applied by the applicant, the fire damper for a range hood includes a valve body with an air inlet, a fusing component, and a first valve plate and a second valve plate rotatably disposed on the valve body, the first valve plate and the second valve plate rotate in the same rotating direction to open or close the air inlet, the valve body is respectively provided with a first closing member for closing the first valve plate and a second closing member for closing the second valve plate, the first closing member and the second closing member are fixed on the valve body through a common fusing component and separated from the corresponding valve plates in a normal state, the first closing member and the second closing member are respectively connected with corresponding elastic members and separated from the fusing component in a fusing state, and move towards the same direction under the action of the corresponding elastic piece, and further drive the corresponding valve plate to rotate so that the air inlet tends to be closed.

When the range hood works for a long time, the valve body is stained with oil stains, so that the opening difficulty of the other valve plate is increased; when the range hood is closed, one valve plate is closed first due to uneven external resistance, and when the other valve plate is closed, poor sealing may occur, which causes oil smoke in a flue to be mixed into a kitchen of a user, and influences the kitchen environment; in addition, the valve plate is usually made of a thin cold plate or a galvanized plate, and the valve plate is easy to corrode and rust or deform by air in the long-term use process. In addition, the elastic part is directly exposed on one surface adjacent to the public flue, and after the flue is ignited, the elastic part is likely to be subjected to thermal deformation and lose the action of tensile force, so that the valve plate cannot be closed in emergency; due to the fact that the valve plate may deform under the factors of actual assembly, oil smoke corrosion and the like, the valve plate is driven to rotate towards the closed state position by the closing member, the closing member is likely to be incapable of pressing the valve plate, and the phenomenon that the oil smoke flows backwards due to the fact that the air inlet of the valve body channel is not tightly closed is likely to occur.

Therefore, a need exists for further improvements to existing fire dampers for range hoods.

Disclosure of Invention

The technical problem to be solved by the invention is to provide a fire damper for a range hood, which can reliably close a valve body channel after a flue is on fire so as to achieve the purpose of blocking oil smoke from flowing backwards, aiming at the current situation of the prior art.

In order to solve the technical problems, the technical scheme adopted by the invention is as follows: a fire damper for a range hood, comprising:

the valve body comprises a first flow channel and a second flow channel which form an included angle and are communicated with each other, wherein the end part of the first flow channel is a smoke inlet and is used for being communicated with an air outlet of the range hood in a fluid mode, and the end part of the second flow channel is a smoke outlet and is used for being communicated with a common flue in a fluid mode;

the method is characterized in that:

one of the first flow passage and the second flow passage is provided with an extension section which is reversely prolonged from the communication part of the first flow passage and the second flow passage; and, also include:

a valve core which is arranged in the extension section in a piston mode in a sliding mode;

and the driving mechanism is used for driving the valve core to slide back and forth so as to enable the valve core to block or open the communication position.

The extension section can be formed by reversely extending the first flow channel and can also be formed by reversely extending the second flow channel, and one of the design modes is adopted: the extension section is formed by extending the second flow channel in the opposite direction.

The first flow channel and the second flow channel can be mutually vertical or communicated in an acute angle, and from the viewpoint of simple processing, the valve body is preferably provided with a smoke inlet pipe and a smoke exhaust pipe which are mutually communicated and have T-shaped sections, the flow channel in the smoke inlet pipe is the first flow channel, and the flow channel in the smoke exhaust pipe is the second flow channel; the valve core is cylindrical, the outer diameter of the valve core is matched with the inner diameter of the smoke exhaust pipe, and the length of the valve core along the axial direction of the valve core is not smaller than the inner diameter of the smoke inlet pipe at the communication position. By the design, when the valve core is positioned at the communication position, the communication position can be blocked.

In order to reduce the contact degree of the driving mechanism to the oil fume flow, a first chamber extending along the axial direction of the fume inlet pipe is arranged on the outer side of the tail end of the extension section, a second chamber is arranged between the first chamber and the fume inlet pipe, and the driving mechanism is partially positioned in the first chamber and the second chamber.

The driving mechanism has various structural forms, can adopt the form of a gear and a transmission rod, and can also adopt the form of a structure of matching the gear, the transmission rod and a rack, and from the viewpoint of structural reliability, the driving mechanism preferably comprises

The first transmission rod is partially positioned in the second chamber, one end of the first transmission rod penetrates into the first flow channel of the smoke inlet pipe, and a first transmission gear is fixedly penetrated on the first transmission rod;

the part of the second transmission rod is positioned in the second cavity, is parallel to the first transmission rod, is penetrated with a second transmission gear meshed with the first transmission gear, and one end of the second transmission rod penetrates through the second cavity, enters the first cavity and is penetrated with a third transmission gear; and

and the third transmission rod is used for driving the valve core to move back and forth towards the communicating direction, is parallel to the second transmission rod, is partially positioned in the first cavity, is fixedly penetrated with a fourth transmission gear meshed with the third transmission gear at the first end of the third transmission rod positioned in the first cavity, and is in threaded connection with an inner shaft hole formed in the valve core along the axial direction at the second end positioned in the extension section.

In order to reliably block the communication position of the first flow passage and the second flow passage in the fire state of the flue, the first transmission rod is provided with an energy storage elastic piece which enables the first transmission rod to rotate towards the reverse rotation direction so as to enable the valve core to always have the trend of moving towards the smoke exhaust port, and the energy storage elastic piece is in an energy storage state in the state that the valve core is positioned in the extension section. The energy storage elastic piece is arranged on the first transmission rod, namely is positioned in the second cavity far away from the smoke exhaust port, and the energy storage elastic piece is not directly exposed in the oil smoke environment and is prevented from being deformed by heating when a public flue is on fire, so that the purpose of reliably making the valve core have the trend of moving towards the smoke exhaust port is achieved.

In order to enable the energy storage elastic piece to be in an energy release state, a fusing ring is fixedly penetrated at one end of the first transmission rod, which is positioned in the first flow passage, and the first transmission rod is fixed on the side wall of the smoke inlet pipe through the fusing ring, namely, the smoke inlet pipe and the first transmission rod are in a separation state when the fusing ring is in a fusing state. In addition, as the fuse link is arranged in the smoke inlet pipe, when a fire breaks out in a room, the fire can spread along the smoke inlet pipe, the fuse link is fused, the smoke inlet pipe is in a separation state with the first transmission rod, and then the connection part can be blocked through the driving mechanism, so that the open fire is blocked from spreading into the public flue.

The energy storage elastic part can adopt a coil spring, but preferably, the energy storage elastic part is a torsion spring arranged on the first transmission rod, the fixed end of the torsion spring is connected with the wall plate of the second chamber, and the force application end of the torsion spring is arranged on the first transmission rod.

In order to limit the valve core to move out of the smoke outlet, a contraction section for limiting the valve core to continue to move towards the smoke outlet is arranged at the position, close to the communication position, of the inner side wall of the smoke exhaust pipe.

Specifically, the valve core is provided with an annular inclined surface which extends in an inclined way towards the axis direction of the valve core on the peripheral wall of one end facing the smoke exhaust port, and correspondingly, the end part of the contraction section adjacent to the communication part is provided with an inclined pipe orifice matched with the annular inclined surface of the valve core.

The end face of one end of the valve core, which is adjacent to the smoke exhaust port, is closed, so that the second end of the third transmission rod is prevented from penetrating out of the valve core and being polluted by oil stains.

Compared with the prior art, the valve core of the fireproof valve for the range hood can move towards the communication position under the driving of the driving mechanism to block the communication position when the flue is on fire, so that the first flow passage and the second flow passage in the valve body are blocked, and the aim of blocking the backflow of oil smoke is fulfilled; the valve core moves towards the communication position in the form of the piston, and the valve core is not easy to deform, so that the communication position can be more reliably blocked, and the situation that the communication position is blocked by the valve core is not firm is reduced; the energy storage elastic piece enables the valve core to have a trend of moving towards the direction of the smoke exhaust port to block the communication position of the first flow channel and the second flow channel, the energy storage elastic piece is located on one side far away from the public flue and located in the second chamber, the possibility of thermal deformation of the elastic piece is reduced, the elastic piece is prevented from losing efficacy, and then the valve core is driven to move reliably to achieve the purpose of blocking the communication position.

Drawings

FIG. 1 is a schematic structural view of an embodiment of the present invention with the communication in an open state;

FIG. 2 is a cross-sectional view of FIG. 1;

FIG. 3 is a schematic view of the structure of FIG. 2 at another angle;

FIG. 4 is a schematic view of a portion of the structure of FIG. 1;

FIG. 5 is a cross-sectional view of an embodiment of the present invention with communication blocked;

FIG. 6 is a schematic view of the structure of FIG. 5 at another angle;

FIG. 7 is an enlarged view of portion A of FIG. 3;

FIG. 8 is an enlarged view of the portion B of FIG. 5;

fig. 9 is a schematic structural diagram of a fuse ring according to an embodiment of the present invention.

Detailed Description

The invention is described in further detail below with reference to the accompanying examples.

As shown in fig. 1 to 8, the fire damper for a range hood according to an embodiment of the present invention includes a valve body 1, a valve core 3, an energy storage elastic member 6, and a driving mechanism 4 for driving the valve core 3 to slide back and forth to close or open a communication position 113 of the valve core 3.

As shown in fig. 2 to 6, the valve body 1 includes a first flow channel 111 and a second flow channel 112 which are mutually included and communicated, wherein an end of the first flow channel 111 is a smoke inlet 111a, the smoke inlet 111a is used for being in fluid communication with an air outlet of the range hood, an end of the second flow channel 112 is a smoke outlet 112b, and the smoke outlet 112b is used for being in fluid communication with a common flue; specifically, the valve body 1 has a smoke inlet pipe 11a and a smoke outlet pipe 11b which are communicated with each other and have a T-shaped cross section, a flow passage in the smoke inlet pipe 11a is a first flow passage, and a flow passage in the smoke outlet pipe 11b is a second flow passage 112. In addition, one of the first flow channel 111 and the second flow channel 112 has an extending section 13 extending from a connecting portion 113 of the two, and in this embodiment, the extending section 13 is formed by extending the second flow channel 112 in the opposite direction, as shown in fig. 2, 3, 5 and 6.

As shown in fig. 2 and 3, the spool 3 is disposed slidably in a piston manner in the extension section 13; as shown in fig. 4, the valve core 3 is cylindrical, the outer diameter of the valve core 3 is matched with the inner diameter of the smoke exhaust pipe 11b, and the length of the valve core 3 along the axial direction is not less than the inner diameter of the smoke inlet pipe 11a at the communication part 113, as shown in fig. 5 and 6. As shown in fig. 4, the outer peripheral wall of the valve body 3 is provided with a guide rib 33 extending along the axial direction thereof, and correspondingly, a guide groove (not shown) engaging with the guide rib 33 in a limited manner is formed in the extension section 13 of the valve body, the extending direction of the guide groove coincides with the extending direction of the guide rib 33, and the guide rib 33 is slidably limited in the guide groove.

As shown in fig. 2, fig. 3, fig. 5 and fig. 6, the extension section 13 has a first chamber 12a extending along the axial direction of the smoke inlet pipe 11a at the outer side of the end, and a second chamber 12b is provided between the first chamber 12a and the smoke inlet pipe 11a, and the driving mechanism 4 is partially located in the first chamber 12a and the second chamber 12 b. Specifically, the driving mechanism includes a first transmission rod 41, a second transmission rod 422 and a third transmission rod 43 for driving the valve plug 3 to move back and forth in the direction of the communication part 113, wherein the first transmission rod 41 is partially located in the second chamber 12b, a first through hole is formed in the sidewall of the smoke inlet pipe 11a, a first bearing 412 is disposed between the first through hole and the first end of the first transmission rod 41, an inner ring of the first bearing 412 is fixedly inserted into the first end of the first transmission rod 41, and an outer ring of the first bearing 412 is supported in the first through hole, so that the first end of the first transmission rod 41 is rotatably disposed in the first through hole through the first bearing 412; a second through hole is formed in the wall plate 121 of the second chamber 12b opposite to the smoke inlet pipe 11a, a second bearing 413 is disposed between the second through hole and the second end of the first transmission rod 41, an inner ring of the second bearing 413 is fixedly inserted into the second end of the first transmission rod 41, and an outer ring of the second bearing 413 is supported in the second through hole, so that the second end of the first transmission rod 41 is partially rotatably disposed in the second through hole through the second bearing 413. In addition, a first transmission gear 421 is fixedly inserted into the first transmission rod 41, and the first transmission gear 421 is located in the second chamber 12b, as shown in fig. 2, 3, 5 and 6.

As shown in fig. 2, the second transmission rod 422 is partially located in the second chamber 12b, is parallel to the first transmission rod 41, and is penetrated by a second transmission gear 423 engaged with the first transmission gear 421, the second transmission gear 423 is also located in the second chamber 12b, a third through hole is formed in the side wall of the smoke inlet pipe 11a, the third through hole is located above the first through hole, a third bearing 4221 is arranged between one end of the second transmission rod 422 and the third through hole, an inner ring of the third bearing 4221 is penetrated and fixed at one end of the second transmission rod 422, and an outer ring of the third bearing 4221 is supported in the third through hole, so that one end of the second transmission rod 422 is rotatably disposed in the third through hole through the third bearing 4221; a fourth through hole is further formed in the wall plate 121 of the second chamber 12b opposite to the smoke inlet pipe 11a, the fourth through hole is located above the second through hole, a fourth bearing 4222 is arranged between the other end of the second transmission rod 422 and the fourth through hole, an inner ring of the fourth bearing 4222 is fixedly penetrated at the other end of the second transmission rod 422, and an outer ring of the fourth bearing 4222 is supported in the fourth through hole, so that the other end of the second transmission rod 422 is partially and rotatably arranged in the fourth through hole through the fourth bearing 4222, in addition, the other end of the second transmission rod 422 can penetrate through the fourth through hole of the second chamber 12b, enter the first chamber 12a and is fixedly penetrated with a third transmission gear 424, and the third transmission gear 424 is located in the first chamber 12 a.

As shown in fig. 2, 3, 5 and 6, the third transmission rod 43 is parallel to the second transmission rod 422, and the third transmission rod 43 is partially located in the first chamber 12a, a first end of the third transmission rod 43 located in the first chamber 12a is fixedly penetrated with a fourth transmission gear 425 engaged with the third transmission gear 424, the extension section 13 is separated from the first chamber 12a by a partition 426, a fifth through hole is formed in the partition 426, a fifth bearing 431 is arranged between the third transmission rod 43 and the fifth through hole, an inner ring of the fifth bearing 431 is fixedly penetrated on the third transmission rod 43, and an outer ring of the fifth bearing 431 is supported in the fifth through hole, so that the third transmission rod 43 is partially and rotatably arranged in the fifth through hole by the fifth bearing 431; as shown in fig. 2, 3, 5 and 6, the valve core 3 is provided with an inner shaft hole 31 along the axial direction, and the inner shaft hole 31 is internally provided with an internal thread, correspondingly, the third transmission rod 43 penetrates through the first chamber 12a and is provided with an external thread on the outer peripheral wall of the second end in the extension section 13, and the second end of the third transmission rod 43 is in threaded connection with the inner shaft hole 31 of the valve core 3.

When the flue is in a fire state, in order to close the communication part 113 of the valve core 3, the energy storage elastic piece 6 is arranged on the first transmission rod 41, and the first transmission rod 41 rotates towards the reverse rotation direction, so that the valve core 3 always has a trend of moving towards the smoke exhaust port 112b, and in a state that the valve core 3 is positioned in the extension section 13, the energy storage elastic piece 6 is in an energy storage state. As shown in fig. 8, the energy storage elastic member 6 is a torsion spring disposed on the first transmission rod 41, a fixed end of the torsion spring is connected to the wall plate 121 of the second chamber 12b, a force applying end 61 of the torsion spring is mounted on the first transmission rod 41, specifically, a limiting block 411 is disposed on a peripheral wall of one end of the first transmission rod 41 far away from the smoke inlet pipe 11a, the limiting block 411 is provided with a limiting groove 4111 extending along an axial direction of the first transmission rod 41, the force applying end 61 of the torsion spring is limited in the limiting groove 4111 of the first transmission rod limiting block 411, which is specifically shown in fig. 8.

In addition, as shown in fig. 2 to fig. 7, the fusing ring 5 is sleeved on one end of the first transmission rod 41 located in the first flow channel 111, and the cross section of one end of the first rotation rod 41 located in the first flow channel 111 is non-circular, in this embodiment, the cross section of one end of the first transmission rod 41 located in the first flow channel 111 is square, as shown in fig. 7. As shown in fig. 9, a concentrically arranged connecting piece 51 is fixed on the fusing ring 5 by hot melting, the connecting piece is semicircular, a V-shaped opening 511 matched with the square end of the first transmission rod 41 is formed in the position, corresponding to the central hole of the fusing ring 5, of the connecting piece 51, the V-shaped opening 511 is formed in the right-angle side of the connecting piece 51, the square end of the first transmission rod 41 is arranged on the fusing ring 5 in a penetrating manner and limited on the V-shaped opening 511 of the connecting piece 51, namely, the first transmission rod 41 and the fusing ring 5 are fixed in a limiting manner, and a square hole matched with the square end of the first transmission rod can be directly formed in the fusing piece to realize the relative fixed connection between the fusing piece and the first transmission rod; in addition, as shown in fig. 2, 3 and 7, the fusing ring 5 is fixed on the sidewall of the smoke inlet pipe 11a by the screw 2, so that the first transmission rod 41 is fixed on the sidewall of the smoke inlet pipe 11a by the fusing ring 5, that is, the smoke inlet pipe 11a can be in a disengaged state with the first transmission rod 41 when the fusing ring 5 is in a fused state. When the flue is in a fire state, the fusing ring is in a fusing state, the first transmission rod 41 is separated from the fixation of the side wall of the smoke inlet pipe 11a, the first transmission rod 41 rotates under the action of the energy storage elastic piece 6 to drive the first transmission gear 421 to rotate, at the moment, the second transmission rod 422 rotates under the transmission meshing of the first transmission gear 421 and the second transmission gear 423, then the power is transmitted to the third transmission rod 43 under the transmission meshing of the third transmission gear 424 and the fourth transmission gear 425, and finally the third transmission rod 43 drives the valve core 3 to move towards the smoke outlet 112b direction of the second flow passage 112 to seal the communication part 113 and block the first flow passage 111 and the second flow passage 112. In addition, the fusing ring 5 is arranged in the smoke inlet pipe 11a, so that the invention can also be used for blocking the open fire from spreading into the public flue when an indoor fire is started.

In this embodiment, in order to limit the valve core 3 from moving out of the smoke exhaust port 112b, a contraction section 110 for limiting the valve core 3 from continuing to move towards the smoke exhaust port 112b is disposed at a position on the inner side wall of the smoke exhaust pipe 11b adjacent to the communication position 113, specifically, the valve core 3 has an annular inclined surface 32 extending obliquely towards the axial direction of the valve core on the outer peripheral wall of one end facing the smoke exhaust port 112b, and correspondingly, an inclined nozzle 1101 matched with the annular inclined surface of the valve core is disposed at an end of the contraction section 110 adjacent to the communication position 113. Furthermore, in order to prevent the end of the third transmission rod 43 in driving connection with the valve core 3 from being contaminated by oil stains, the end face of the end of the valve core 3 adjacent to the smoke discharge port 112b is closed, that is, the end of the valve core 3 remote from the fourth transmission gear 425 is closed, so that the second end portion of the third transmission rod 43 is prevented from penetrating the valve core 3 and contacting the oil smoke flow.