A fire-proof check valve

Abstract

The present invention provides a fire-proof check valve, comprising a valve body, a valve element, a force-applying part and a closing part; a valve shaft is arranged on the valve body, and the valve element performs an opening and closing movement around the valve shaft; the force-applying part comprises a flip connecting rod and a balancing connecting rod, a first shaft is arranged on the valve body, the head end of the flip connecting rod is hinged to the valve body through the first shaft, the end of the flip connecting rod and the head end of the balancing connecting rod are hinged to each other, and the end of the balancing connecting rod is hinged to the valve element; the closing part comprises a fuse piece and a spring-pressing member, and a second shaft is arranged on the valve body; the flip connecting rod is provided with a convex portion protruding toward the valve piece, and after the fuse piece is melted, the rotating end of the spring-pressing member rotates around the second shaft until the working end of the spring-pressing member abuts against the convex portion, and a human-shaped support structure is formed between the convex portion and the spring-pressing member, so that the flip connecting rod is locked to the valve closing position. The present invention adopts a human-shaped support structure with a stable structure, which greatly enhances the structural strength.

Description

Technical Field

[0001] The invention belongs to the technical field of residential exhaust ducts, and in particular relates to a fire-proof check valve. Background Art

[0002] The fire check valve is an important component of the residential exhaust duct system. Its main function is to discharge smoke smoothly and prevent smoke backflow. At the same time, it is equipped with a locking structure to facilitate effective fire prevention when necessary to ensure safety. Its fire prevention function is mainly to provide a thermal melt sheet on the fire check valve. In the event of a fire, the thermal melt sheet reaches its critical point and deforms and melts to completely close the exhaust port of the fire check valve to prevent the fire from spreading further.

[0003] For example, Chinese patent application 201710147354.2 discloses a fire check valve, which solves the problem that the fire check valve loses its smoke-isolating effect in a high-temperature environment. A fire check valve comprises a valve body, a valve plate, a connecting rod, a paddle, a temperature-sensing element and an elastic element, wherein the valve body is provided with an exhaust port, the valve plate cover is provided on the exhaust port, the valve plate is connected to the valve body through a connecting rod, the paddle is rotatably connected to the valve body, the temperature-sensing element is fixed to the valve body, one end of the elastic element is fixedly connected to the valve body, the other end of the elastic element is connected to the paddle and drives the paddle to abut against the temperature-sensing element, the paddle is provided with a clamping portion, and the connecting rod is provided with a clamping fitting portion; when the elastic element drives the paddle to rotate relative to the valve body and squeezes the connecting rod so that the connecting rod closes the exhaust port through the valve plate, the clamping portion cooperates with the clamping fitting portion to prevent the connecting rod from rotating relative to the valve body.

[0004] For another example, Chinese patent application 201821290666.5 discloses a locking structure for a fire check valve and a diversion type flue fire check valve, which belong to the field of valve technology, and include a base and an elastic element arranged in a valve body, a movable connecting rod being arranged on the base, a locking piece being hinged on one side of the base, the elastic element being fixed on a hinge shaft of the locking piece and driving the locking piece to resist the movable connecting rod, a connecting piece being hinged at one end of the locking piece to be able to extend from the valve body and be fixedly connected, and the hinge shaft for the hinged connecting piece adopts a low-melting-point alloy fuse.

[0005] At present, the fire-proof check valve in the prior art still has the defects of complex structure and poor matching stability between the locking mechanisms. Summary of the invention

[0006] In view of the defects of the prior art, the present invention provides a fire-proof check valve, which greatly enhances the structural stability and has a simple structure by cooperating with a more stable human-shaped support structure.

[0007] The specific technical solutions of the present invention are as follows:

[0008] A fire-proof check valve comprises a valve body having an exhaust passage, a valve element capable of opening and closing between an open valve position and a closed valve position, a force-applying portion for biasing and / or pulling the valve element toward the closed valve position; and a closing portion for completely locking the valve element to the closed valve position;

[0009] The valve body is provided with a valve shaft, and the valve element performs an opening and closing movement around the valve shaft between an open valve position and a closed valve position;

[0010] The force-applying part includes a flip connecting rod and a balancing connecting rod. A first shaft is arranged on the side of the valve body located at the inlet of the exhaust passage. The head end of the flip connecting rod is hinged to the valve body through the first shaft. The end of the flip connecting rod is hinged to the head end of the balancing connecting rod. The end of the balancing connecting rod is hinged to the valve element.

[0011] The closing part includes a spring-pressing component and a fuse acting on the spring-pressing component. A second axis is arranged on the valve body, and the second axis is arranged between the first axis and the valve axis. The three are arranged to be parallel to each other. The flip connecting rod is provided with a convex portion protruding toward the valve plate. After the fuse is melted, the rotating end of the spring-pressing component rotates around the second axis until the working end of the spring-pressing component is against the convex portion, and a human-shaped support structure is formed between the convex portion and the spring-pressing component to lock the flip connecting rod to the valve closing position.

[0012] In the above technical solution of the present invention, the valve shaft and the first shaft are relatively fixed, the distance between the balancing link and the valve shaft is also fixed, and a four-bar linkage is formed between the valve shaft, the first shaft, the flip link, the balancing link and the valve element, specifically a double rocker mechanism with the valve shaft and the first shaft as the frame, the flip link and the valve element as the rockers, and the balancing link as the connecting rod.

[0013] The flip connecting rod is used as the action point of the force-applying part, that is, the flip connecting rod is driven to rotate by an external force such as an elastic member such as a spring, so as to drive the valve element to rotate around the valve shaft, thereby closing the exhaust passage.

[0014] Furthermore, the closing part directly acts on the flip connecting rod to lock the flip connecting rod, thereby realizing the complete locking of the valve element to the closed valve position by pulling the valve element sideways through the flip connecting rod; the closing part is provided with a fusible piece and a spring-loaded component limited by the fusible piece, wherein the spring-loaded component has a certain tension, and after the limitation of the fusible piece is eliminated, the spring-loaded component can be displaced within a certain range; specifically, the displacement process of the spring-loaded component is a rotation process around the second axis, and the displacement process here refers to the rotation process of the working end of the spring-loaded component (the end not hinged to the second axis).

[0015] The second axis is arranged between the first axis and the valve axis, specifically in the area close to the first axis. The spring-pressing member in displacement contacts with the flip connecting rod, driving it to rotate toward the inlet of the exhaust passage. After the valve element is in the valve closing position, it cannot continue to rotate. At this time, the working end of the spring-pressing member abuts against the convex part of the flip connecting rod, forming a human-shaped support structure between the convex part and the spring-pressing member, wherein an angle is formed between the spring-pressing member and the flip connecting rod to form a limit, and the flip connecting rod cannot rotate toward the outlet of the exhaust passage.

[0016] Furthermore, after a human-shaped support structure is formed between the convex portion and the spring-pressing member to lock the valve element, the angle between the spring-pressing member and the convex portion on the flip link is preferably less than 100°. For example, at this time, the angle between the spring-pressing member and the convex portion on the flip link is 90°, forming a right-angle support with more stable supporting performance. Moreover, when subjected to external forces, such as heat waves caused by fire, due to the existence of the human-shaped support structure between the spring-pressing member and the flip link, before the elements are destroyed and lose their constraints, the position of the valve element will not change completely or almost completely, and there will be no shaking.

[0017] In the fireproof check valve disclosed in the prior art 201710147354.2, a limit locking structure is formed by means of a slot (slot-fitting part) and a stop plate (slotting part). As we know, in order to cooperate with the slot, a latch tooth that cooperates with the slot needs to be provided on the stop plate. Due to its small structure, the structural strength of the latch tooth will be greatly reduced. Therefore, the limit structure formed by the locking connecting rod between the slot and the latch tooth has the defects of low structural strength and easy to produce small displacement and shaking.

[0018] According to another specific embodiment of the present invention, the force-applying part further includes a connecting rod torsion spring, which is sleeved on the first axis and is configured to be compressed by the flipped connecting rod; when smoke and exhaust need to be exhausted, an airflow with a certain rate blows the valve element open, and when it is completely exhausted, under the action of the connecting rod torsion spring, the valve element is reset to a closed state to prevent smoke and odor contamination.

[0019] In this solution, when the valve element is in the valve closing position, the end of the flip connecting rod is preferably located on the side of the first axis away from the valve element. At this time, the center of gravity of the flip connecting rod and the balancing connecting rod is located on the side of the first axis away from the valve element. The flip connecting rod and the balancing connecting rod provide a gravity closing effect for the closing of the valve element, so as to further improve the sealing performance of the closing of the valve element.

[0020] Furthermore, when the valve element is in the open state, the end of the flip connecting rod is located on the side of the first axis close to the valve element, and the center of the flip connecting rod and the balancing connecting rod is located on the side of the first axis close to the valve element; the flip connecting rod and the balancing connecting rod will provide a gravity opening effect for the opening of the valve element, so as to further increase the opening range of the valve element, so that it is in the maximum opening position, thereby quickly exhausting smoke and exhaust.

[0021] The flip connecting rod may be a straight rod or a curved rod.

[0022] Preferably, the valve element is inclined from top to bottom toward the inlet of the exhaust passage, wherein the inclination angle of the valve element is less than 15°, for example, the inclination angle of the valve element is 10°; in the fire check valve in the prior art, the valve element (valve plate) has a large inclination angle, and some of the inclination angles are above 30°, the main purpose of which is to enhance the sealing of the valve element and enhance the tendency of the valve element to rebound to the closed valve state, so as to save the service life of the reset elastic element (spring); however, after setting a larger inclination angle, there will be problems such as a small opening angle of the valve element, increased opening resistance, and a small outflow port of the exhaust passage, which is not conducive to the smoke exhaust process and is prone to smoke exhaust blockage during use; in the present invention, the effect of gravity-driven tendencies in different directions when the flip connecting rod and the support connecting rod are in different positions is utilized, and the valve element with a smaller inclination angle is cooperated to realize a smooth opening and closing process of the valve element, while significantly increasing the opening angle of the valve element, reducing the resistance to the opening of the valve element, and increasing the service life of the connecting rod torsion spring.

[0023] According to another specific embodiment of the present invention, a fixing seat is arranged on the valve body, the fixing seat has two opposite side plates, and a receiving groove is formed between the two side plates. The fuse is arranged on one of the side plates and limits the spring-pressing member in the receiving groove.

[0024] Furthermore, a front connecting ear and a rear connecting ear are respectively provided at the two ends of the side plates, the first axis passes through the front connecting ears of the two side plates, the second axis passes through the rear connecting ears of the two side plates, and a return spring is sleeved on the second axis, and the return spring is configured to be compressed by the rotating end of the spring-pressing component.

[0025] Among them, the front connecting ear and the rear connecting ear in the fixed seat are both located above the fixed seat, so that the fixed seat as a whole presents a posture with high ends and low middle. At this time, the aforementioned accommodating groove is formed in the middle position of the fixed seat, and the spring-pressing component is limited in the accommodating groove by the fuse in the normal state; at this time, in the normal switching process of the valve element between the open valve position and the closed valve position, the flip connecting rod will not interfere with the spring-pressing component, that is, there is no possible contact or constraint between the two, and the rotation process of the flip connecting rod will not be affected.

[0026] Preferably, the first axis and the second axis are flush with each other at a horizontal height, the spring-loaded component is plate-shaped or sheet-shaped, and the return spring provides an external driving force for the spring-loaded component. When the fuse piece melts or deforms at high temperature to eliminate the limit on the spring-loaded component, the spring-loaded component rotates to abut against the convex part of the flip connecting rod through the elastic force of the return spring to form a human-shaped support structure. At this time, the return spring is still in a compressed state. Even if the return spring is destroyed during a high-temperature fire, due to the mutual support between the flip connecting rod and the spring-loaded component, the spring-loaded component cannot rotate forward or reverse before being destroyed, that is, the spring-loaded component has a unique and fixed position.

[0027] According to another specific embodiment of the present invention, a connecting piece is provided at the center of the valve element, the connecting piece is provided with a hinged end, and the end of the balancing connecting rod is hinged to the hinged end of the connecting piece. The connecting piece is preferably integrally formed on the valve element.

[0028] According to another specific embodiment of the present invention, the protrusion has an arc-shaped guiding side edge and an abutment portion located on the arc-shaped guiding side edge near the valve element, and the working end of the elastic pressing member is flipped along the arc-shaped guiding side edge to the abutment portion.

[0029] Before the valve element is in the valve closing position, the working end of the spring-pressing member contacts and squeezes the arc-shaped guiding side edge, so that the flip connecting rod rotates toward the valve closing position; after the valve element is in the valve closing position, the working end of the spring-pressing member just flips to the abutment portion to form a stable abutment support.

[0030] The curvature of the arc-shaped guiding side edge preferably changes gradually, and as the spring-pressing member turns over, the biasing effect of the spring-pressing member on the turning connecting rod becomes more and more obvious;

[0031] Furthermore, an anti-skid protrusion or an anti-skid tooth structure, such as ratchet teeth, is provided on the arc-shaped guiding side to prevent the elastic pressing member from rotating.

[0032] According to another specific embodiment of the present invention, it also includes a connecting seat arranged at the lower end of the valve element, the force-applying part is also provided with a reset closing spring, the connecting seat is hinged to the valve shaft, and the connecting seat is configured to compress the reset closing spring.

[0033] In this solution, the rotational cooperation between the valve shaft and the valve element is achieved by setting a connecting seat, and the valve shaft is set outside the valve element, which simplifies the installation structure on the one hand and increases the turning space of the valve element on the other hand.

[0034] As an extension of the present invention, a stop opening portion is also provided for limiting the opening of the valve element. The stop opening portion is arranged on the side of the outflow port of the valve body located in the exhaust passage, and the stop opening portion includes a stop opening connecting rod, a temperature sensing element and a driving spring; wherein a third axis parallel to the valve axis is provided on the valve body, the driving spring is sleeved on the third axis, the head end of the stop opening connecting rod is hinged to the third axis and presses the driving spring; wherein the stop opening connecting rod is provided with a connecting portion, one end of the temperature sensing element is fixed to the valve body, and the other end is fixed to the connecting portion; after the temperature sensing element is melted, the stop opening connecting rod is rotated to buckle its end against the valve element to prevent the valve element from opening.

[0035] In the present invention, the closing part is used to lock the valve element to the closed position in the event of an indoor fire (i.e., the fire source is generated indoors and the fire spreads to the inlet position of the exhaust passage); the stop-opening part is used in the event of an outdoor fire (i.e., the fire source is generated outdoors and the fire spreads along the exhaust duct to the outlet position of the exhaust passage), and by respectively arranging an internal fire-setting structure and an external fire-prevention structure, double insurance of internal and external fire prevention is achieved.

[0036] In the process of switching the valve element between the open valve position and the closed valve position, the stop-open connecting rod will not contact the valve element, that is, it will not cause interference with the spatial position of the valve element.

[0037] After the temperature sensing element is melted, the stop-opening connecting rod rotates until its end is buckled on the valve element. Preferably, a thrust surface structure that matches the surface of the valve element is provided at the end of the stop-opening connecting rod to prevent the valve element from shaking.

[0038] More preferably, a convex structure may be provided on the surface of the valve element, such as a retaining strip that cooperates with the end of the anti-opening connecting rod, so as to form a limit between the two, so as to further improve the stability of the valve element in the event of a fire.

[0039] According to another specific embodiment of the present invention, the stop opening part also includes a locking plate; a fourth axis is arranged on the valve body, the fourth axis is located between the third axis and the valve axis, and the fourth axis is parallel to the valve axis, and a return spring is sleeved on the fourth axis; one end of the locking plate is hinged to the fourth axis and is arranged to compress the return spring, and a barb is arranged on the other end of the locking plate, and after the temperature sensing element fuses, the locking plate and the stop opening connecting rod rotate synchronously or asynchronously, so that the barb is buckled to the edge of the stop opening connecting rod away from the valve element, and a human-shaped anti-detachment structure is formed between the locking plate and the stop opening connecting rod to limit the opening of the valve element.

[0040] According to another specific embodiment of the present invention, a toothed guide section is provided on the edge of one side of the stop-open link away from the valve element, and a barb is buckled at the starting point of the toothed guide section. After the temperature sensing element is melted, the barb rotates along the toothed guide section as the stop-open link rotates. When the end of the stop-open link abuts against the valve element and biases the valve element to a closed state, the barb rotates to the end point of the toothed guide section. At this time, due to the limitation of the barb, the stop-open link cannot be flipped in the opposite direction and is firmly fixed.

[0041] The present invention has the following beneficial effects:

[0042] The present invention is provided with a force-applying part, and a double rocker structure is formed between the double connecting rod of the force-applying part and the valve element, so that the valve element can be smoothly switched between the valve opening position and the valve closing position, the opening process of the valve element is smoother, the resistance of opening or closing is small, the opening angle is larger, and the sealing performance is better;

[0043] The present invention is provided with a closing part, and a human-shaped support structure can be formed between the elastic pressure component in the closing part and the flip connecting rod of the force-applying part. The elastic pressure component limits the rotation of the flip connecting rod and locks it in the valve closing position. The whole locking mechanism has a strong structural strength and high locking stability, thereby preventing the fire from spreading to the outdoors through the exhaust passage when a fire occurs.

[0044] The present invention is provided with a stop opening part, and a human-shaped anti-detachment structure can be formed between the locking plate in the stop opening part and the stop opening connecting rod. The end of the stop opening connecting rod is firmly buckled on the valve element to limit the opening of the valve element, thereby preventing the fire from spreading to the room through the exhaust passage when a fire occurs.

[0045] The present invention will be further described in detail below in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 It is a schematic diagram of the overall structure of the fire-proof check valve of the present invention;

[0047] Figure 2 It is a partial structural schematic diagram of the fire-proof check valve of the present invention, which shows the state where the valve element is in a normal valve closing position;

[0048] Figure 3 yes Figure 2 Another position state schematic diagram, which shows the state of the valve element in the normal valve open position;

[0049] Figure 4 yes Figure 2 A further state schematic diagram showing a locked state of the closed portion of the valve element;

[0050] Figure 5 It is a schematic diagram of the structure of the closed part of the fire-proof check valve of the present invention in a normal state;

[0051] Figure 6 It is a schematic diagram of the structure of the fire-proof check valve of the present invention in the closed part triggering state;

[0052] Figure 7 It is a structural schematic diagram of the fire-proof check valve of the present invention;

[0053] Figure 8 yes Figure 7 Structural diagram of the suspended part in the trigger state;

[0054] Fig. 9 yes Figure 7 The structural diagram of the suspension opening part;

[0055] Fig.10 yes Fig. 9 Schematic diagram of the partial structure of the suspension part.

[0056] In the description of the present invention, it is necessary to understand that the directions or positional relationships indicated by terms such as “upper”, “lower”, “front”, “back”, “left”, “right”, “horizontal” and “vertical” are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention. They do not indicate or imply that the device or feature referred to must have a specific direction, be constructed and operated in a specific orientation. For those skilled in the art, the above terms should be understood in a broad sense and therefore should not be understood as limitations on the present invention. DETAILED DESCRIPTION

[0057] like Figure 1 As shown in FIG. 10 , a fire-proof check valve comprises a valve body 1 , a valve element 2 (valve plate), a force-applying portion 3 , and a closing portion 4 .

[0058] An exhaust channel 11 is arranged on the valve body 1, and the exhaust channel 11 has an inlet 111 and an outlet 112. A valve seat 12 and a valve shaft 13 arranged on the valve seat 12 near the outlet 112 of the exhaust channel 11 are arranged on the valve body 1 in the exhaust channel 11, wherein the valve element 2 opens and closes around the valve shaft 13 between an open valve position and a closed valve position, and the gas generated in the room and needs to be exhausted flows in from the inlet 111 of the exhaust channel 11, and is exhausted from the outlet 112 of the exhaust channel 11 after the valve element 2 is opened.

[0059] The force-applying portion 3 is arranged at the inlet 111 of the exhaust channel 11, and includes a flip link 31 and a balancing link 32, which are used to pull the valve element 2 toward the valve closing position; a double rocker structure is formed between the flip link 31, the balancing link 32 and the valve element 2. Specifically, a first axis 14 parallel to the valve axis 13 is arranged at the inlet 111 of the exhaust channel 11 of the valve body 1, the head end of the flip link 31 is hinged to the valve body 1 through the first axis 14, the end of the flip link 31 and the head end of the balancing link 32 are hinged to each other, and a connecting piece 21 is arranged at the center of the side of the valve element 2 facing the inlet 111 of the exhaust channel 11, the connecting piece 21 has a hinged end 211, and the end of the balancing link 32 is hinged to the hinged end 211 of the connecting piece 21, thereby forming a double rocker structure with the first axis 14 and the valve axis 13 as the frame, the flip link 31 and the valve element 2 as the rockers, and the balancing link 32 as the connecting rod.

[0060] In order to facilitate the automatic closing of the valve element 2, one of the rockers is selected to apply the automatic reset force. In a preferred example of the present invention, the force applying part 3 can also be a connecting rod torsion spring 33, which is sleeved on the first shaft 14 and is configured to be pressed by the flip connecting rod 31;

[0061] When smoke and gas need to be exhausted, an airflow with a certain rate blows the valve element 2 open and further compresses the connecting rod torsion spring 33. When the gas is completely exhausted, the valve element 2 is reset to the closed position under the action of the connecting rod torsion spring 33.

[0062] In order to improve the sealing performance of the valve element 2 in the closed state, the valve element 2 is tilted from top to bottom toward the inlet 111 of the exhaust passage 11. The tilt angle of the valve element 2 in the present invention is less than 15°, for example Figure 2 The case where the inclination angle is 10° is shown.

[0063] In the present invention, the length and action position of the flip link 31 and the balance link 32 can be designed to provide auxiliary driving force during the opening or closing process of the valve element 2, specifically:

[0064] When the valve element 2 is in the valve closing position, the end of the flip link 31 is preferably located on the side of the first axis 14 away from the valve element 2. At this time, the center of gravity of the flip link 31 and the balancing link 32 are located on the side of the first axis 14 away from the valve element 2, and the flip link 31 and the balancing link 32 provide a gravity closing effect for the closing of the valve element 2.

[0065] When the valve element 2 is in the open state, the end of the flip link 31 is located on the side of the first axis 14 close to the valve element 2. At this time, the centers of the flip link 31 and the balance link 32 are located on the side of the first axis 14 close to the valve element 2; the flip link 31 and the balance link 32 provide a gravity opening effect for the opening of the valve element 2.

[0066] Among them, the flip connecting rod 31 adopts a curved structure design, which can provide a better gravity effect. This design can greatly improve the smoothness of the opening or closing process of the valve element 2, so that the valve element 2 has a larger opening angle and stronger sealing performance in the closed position.

[0067] Furthermore, a sealing ring 22 is provided at the position where the valve element 2 contacts the valve seat 12 for better sealing.

[0068] In a preferred example of the present invention, the force-applying portion 3 may also be provided with a reset closing spring 34, wherein a connecting seat 18 is provided at the lower end of the valve element 2, the connecting seat 18 is hinged to the valve shaft 13, and the connecting seat 18 is configured to compress the reset closing spring 34; after the valve element 2 is opened, the reset closing spring 34 will be further compressed, so that during the closing process, the reset closing spring 34 will provide a biasing force to the valve element 2 to drive the valve element 2 to close.

[0069] The closing part 4 in the present invention includes an internal fuse 41, a spring-pressing member 42 and a return spring 43, wherein the spring-pressing member 42 is selected to be plate-shaped; a second shaft 15 is provided on the valve body 1, and the second shaft 15 is provided between the first shaft 14 and the valve shaft 13, and the three are provided to be parallel to each other; preferably, the second shaft 15 and the first shaft 14 are flush with each other at a horizontal height, and the spring-pressing member 42 has a rotating end and a working end, and the rotating end of the spring-pressing member 42 can rotate around the second shaft 15, but is limited by the internal fuse 41 in a normal state and cannot rotate.

[0070] The flip link 31 has a convex portion 35 protruding toward the valve element 2. After the internal fuse 41 is melted, the limit of the internal fuse 41 on the working end of the spring-pressing member 42 disappears. Under the action of the return spring 43, the rotating end of the spring-pressing member 42 rotates around the second axis 15 until the working end of the spring-pressing member 42 abuts against the convex portion 35, and a human-shaped support structure is formed between the convex portion 35 and the spring-pressing member 42, thereby locking the flip link 31 to the valve closing position.

[0071] When the protrusion 35 abuts against the working end of the spring-pressing member 42, the flip link 31 serving as a rocker is limited and cannot rotate to open the valve element 2. Since the valve element 2 has been covered on the valve seat 12, the flip link 31 serving as a rocker cannot rotate to close the valve element 2 again. At this time, the flip link 31 has a unique and fixed position.

[0072] Furthermore, after the humanoid support structure is formed between the protrusion 35 and the spring member 42 to lock the valve element 2, the angle between the spring member 42 and the flip link 31 is preferably less than 100°, for example Figure 4 The case where the angle is 90° is shown.

[0073] In order to better place the elastic pressure member 42, as Figure 5 , Figure 6 As shown, a preferred installation structure is:

[0074] A fixing seat 19 is provided on the valve body 1 . The fixing seat 19 has two opposite side plates 191 , and a receiving groove 192 is formed between the two side plates 191 . The internal fuse 41 is provided on one of the side plates 191 , and the spring-pressing member 42 is limited in the receiving groove 192 .

[0075] Furthermore, a front connecting ear 193 and a rear connecting ear 194 are respectively provided at both ends of the side plate 191, the first shaft 14 passes through the front connecting ear 193 of the two side plates 191, and the second shaft 15 passes through the rear connecting ear 194 of the two side plates 191. A return spring 43 is sleeved on the second shaft 15, and the return spring 43 is configured to be compressed by the rotating end of the spring-pressing component 42.

[0076] Among them, the front connecting ear 193 and the rear connecting ear 194 in the fixing seat 19 are both located above the fixing seat 19, so that the fixing seat 19 as a whole presents a posture with high ends and low middle. At this time, the aforementioned accommodating groove 192 is formed in the middle position of the fixing seat 19, and the spring-pressing member 42 is limited in the accommodating groove 192 by the internal fuse piece 41 in the normal state.

[0077] An arc-shaped guiding side edge 351 and an abutting portion 352 located on the arc-shaped guiding side edge 351 may be provided near the valve element 2 on the protrusion 35 , and the working end of the elastic pressing member 42 is turned along the arc-shaped guiding side edge 351 to the abutting portion 352 .

[0078] After the internal fuse 41 is melted, if the valve element 2 is not in the valve closing position, the working end of the rotating spring-pressing member 42 contacts and squeezes the arc-shaped guiding side edge 351, so that the flip connecting rod 31 rotates toward the valve closing position, thereby squeezing the valve element 2 to the valve closing position, and the working end of the spring-pressing member 42 just flips to the abutment portion 352 to form a stable human-shaped support.

[0079] Preferably, the curvature of the arc-shaped guiding side edge 351 changes gradually, and as the elastic pressure member 42 turns over, the biasing effect of the elastic pressure member 42 on the turning link 31 becomes more and more obvious.

[0080] In other examples of the present invention, a stop opening portion 5 is also provided to limit the opening of the valve element 2, wherein the stop opening portion 5 is provided on the side of the outlet 112 of the exhaust passage 11 of the valve body 1, and its function is to prevent the outdoor fire from spreading inward.

[0081] like Figure 7As shown in Figure 10, the stop opening part 5 includes a stop opening connecting rod 51, an external fuse 52 (temperature sensing element) and a driving spring 53; wherein a third shaft 16 parallel to the valve shaft 13 is provided on the valve body 1, and the driving spring 53 is sleeved on the third shaft 16, and the head end of the stop opening connecting rod 51 is hinged to the third shaft 16 and presses the driving spring 53; wherein the stop opening connecting rod 51 is provided with a connecting portion 511, and one end of the external fuse 52 is fixed to the valve body 1, and the other end is fixed to the connecting portion 511; wherein after the external fuse 52 is melted, the stop opening connecting rod 51 is rotated to buckle its end against the valve element 2 to prevent the valve element 2 from opening.

[0082] Furthermore, a thrust surface structure 512 that matches with the surface of the valve element 2 is provided at the end of the stop-opening connecting rod 51, so as to improve the stability of the stop-opening connecting rod 51 through surface contact.

[0083] Specifically, the stop opening part 5 is also provided with a locking plate 54, and a fourth axis 17 is provided on the valve body 1, the fourth axis 17 is located between the third axis 16 and the valve shaft 13, and the fourth axis 17 is parallel to the valve shaft 13, and a return spring 55 is sleeved on the fourth axis 17; wherein one end of the locking plate 54 is hinged to the fourth axis 17, and is arranged to compress the return spring 55, and the other end of the locking plate 54 is provided with a barb 541, after the external fuse 52 is melted, the locking plate 54 and the stop opening connecting rod 51 rotate asynchronously, so that the barb 541 is buckled to the side edge of the stop opening connecting rod 51 away from the valve element 2, and a human-shaped anti-detachment structure is formed between the locking plate 54 and the stop opening connecting rod 51 to limit the opening of the valve element 2.

[0084] More specifically, a toothed guide section 513 is provided on one edge of the stop-open link 51 away from the valve element 2, and the barb 541 is buckled at the starting point of the toothed guide section 513. After the external fuse 52 is melted, the barb 541 rotates along the toothed guide section 513 as the stop-open link 51 rotates; when the end of the stop-open link 51 abuts against the valve element 2 and biases the valve element 2 to the closed state, the barb 541 rotates to the end point of the toothed guide section 513. At this time, due to the limitation of the barb 541, the stop-open link 51 cannot be flipped in the opposite direction and is firmly fixed.

[0085] Although the present invention is disclosed as above with preferred embodiments, it is not intended to limit the scope of the present invention. Any person skilled in the art can make some improvements without departing from the scope of the present invention, that is, all equivalent improvements made according to the present invention should be covered by the scope of the present invention.

Claims

1. A fire check valve, characterized in that: include: a valve body having an exhaust passage; A valve element capable of opening and closing between an open valve position and a closed valve position; A force applying portion for biasing and / or pulling the valve element toward a valve closing position; and A closing portion for completely locking the valve element into a closed position; The valve body is provided with a valve shaft, and the valve element performs an opening and closing movement around the valve shaft between a valve opening position and a valve closing position; The force-applying part includes a flip link and a balancing link, a first axis is provided on the valve body at the inlet side of the exhaust passage, the head end of the flip link is hinged to the valve body through the first axis, the end of the flip link and the head end of the balancing link are hinged to each other, and the end of the balancing link is hinged to the valve element; when the valve element is in the valve-closing position, the end of the flip link is located on the side of the first axis away from the valve element, at this time, the center of gravity of the flip link and the balancing link is located on the side of the first axis away from the valve element, and the flip link and the balancing link provide a gravity closing effect for the closing of the valve element; when the valve element is in the open state, the end of the flip link is located on the side of the first axis close to the valve element, at this time, the center of gravity of the flip link and the balancing link is located on the side of the first axis close to the valve element, and the flip link and the balancing link provide a gravity opening effect for the opening of the valve element; The closing part includes a spring-pressing member and a fuse piece acting on the spring-pressing member, a second axis is provided on the valve body, the second axis is provided between the first axis and the valve axis, and the three are provided to be parallel to each other; the flip connecting rod is provided with a convex portion protruding toward the valve element, after the fuse piece is melted, the rotating end of the spring-pressing member rotates around the second axis until the working end of the spring-pressing member abuts against the convex portion, and a human-shaped support structure is formed between the convex portion and the spring-pressing member, so that the flip connecting rod is locked to the valve closing position; The convex portion has an arc-shaped guiding side edge and an abutting portion located on the arc-shaped guiding side edge near the valve element, and the working end of the elastic pressing member is turned over to the abutting portion along the arc-shaped guiding side edge.

2. The fire check valve according to claim 1, characterized in that: The force applying part further comprises a connecting rod torsion spring, which is sleeved on the first shaft and configured to be compressed by the flip connecting rod.

3. The fire check valve according to claim 1, characterized in that: A fixing seat is arranged on the valve body, and the fixing seat has two opposite side plates, and a receiving groove is formed between the two side plates. The fuse piece is arranged on one of the side plates, and the elastic pressure member is limited in the receiving groove.

4. The fire-proof check valve according to claim 3, characterized in that: A front connecting ear and a rear connecting ear are respectively arranged at the two ends of the side plate, the first shaft passes through the front connecting ears of the two side plates, the second shaft passes through the rear connecting ears of the two side plates, and a return spring is sleeved on the second shaft, and the return spring is arranged to be compressed by the rotating end of the spring-pressing component.

5. The fire check valve according to claim 1, characterized in that: A connecting piece is arranged at the center of the valve element, the connecting piece is provided with a hinged end, and the end of the balancing connecting rod is hinged to the hinged end of the connecting piece.

6. The fire check valve according to claim 1, characterized in that: It also includes a connecting seat arranged at the lower end of the valve element, the force-applying part is also provided with a reset closing spring, the connecting seat is hinged to the valve shaft, and the connecting seat is configured to compress the reset closing spring.

7. The fire-proof check valve according to any one of claims 1 to 6, characterized in that: A stop opening portion is also provided to limit the opening of the valve element, the stop opening portion is provided on the side of the outlet of the exhaust passage of the valve body, and the stop opening portion includes a stop opening connecting rod, a temperature sensing element and a driving spring; The valve body is provided with a third shaft parallel to the valve shaft, the driving spring is sleeved on the third shaft, and the head end of the stop-opening connecting rod is hinged to the third shaft and presses the driving spring; The stop link is provided with a connecting portion, one end of the temperature sensing element is fixed to the valve body, and the other end is fixed to the connecting portion; After the temperature sensing element is melted, the anti-opening connecting rod rotates until its end is buckled on the valve element to prevent the valve element from opening.

8. The fire check valve according to claim 7, characterized in that: The stop opening portion also includes a locking piece; A fourth shaft is provided on the valve body, the fourth shaft is located between the third shaft and the valve shaft, and the fourth shaft is parallel to the valve shaft, and a return spring is sleeved on the fourth shaft; One end of the locking plate is hinged to the fourth axis and is configured to compress the return spring, and the other end of the locking plate is provided with a barb. After the temperature sensing element is melted, the locking plate and the stop-opening connecting rod rotate synchronously or asynchronously, so that the barb is buckled to the edge of the stop-opening connecting rod away from the valve element, and a human-shaped anti-detachment structure is formed between the locking plate and the stop-opening connecting rod to limit the opening of the valve element.

9. The fire-proof check valve according to claim 8, characterized in that: A toothed guide section is provided on one side edge of the stop opening link away from the valve element, and the barb is buckled at the starting point of the toothed guide section. After the temperature sensing element is melted, the barb rotates along the toothed guide section as the stop opening link rotates.

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