CN215002283U - Anti-downdraft device and gas water heater - Google Patents

Abstract

The application is suitable for the technical field of electric appliances, and provides an anti-backflow device and a gas water heater, wherein the anti-backflow device comprises a pipe body, a support and an anti-backflow plate, a first channel is formed inside the pipe body, the support is installed on the inner wall of the pipe body, the anti-backflow plate is rotatably installed on the support, the support is a flexible part, and when the anti-backflow plate is rotated to be lapped on the support, the support and the anti-backflow plate are matched to seal the first channel; the support is arranged in the pipe body, the anti-backflow plate is rotatably arranged on the support, and the support is arranged to be a flexible part, so that abnormal sound cannot be generated between the support and the anti-backflow plate, other structures such as a gasket and a washer are not required to be arranged, the material and structure cost is lower, the assembly is simpler and more convenient, and the overall cost of the anti-backflow device is favorably reduced; the gas water heater comprises the anti-downdraft device, and has lower material and structure cost and assembly cost on the basis of ensuring that no abnormal sound is generated between the support and the anti-downdraft plate.

Description

Anti-downdraft device and gas water heater

Technical Field

The application relates to the technical field of electric appliances, in particular to a down draft prevention device and a gas water heater.

Background

The gas water heater uses gas as fuel, and obtains hot water by burning gas inside and transferring heat to cold water flowing through a heat exchanger. The flue gas after burning needs to be discharged to the outdoor through a smoke discharge pipe. The smoke exhaust pipe is generally provided with a down draft prevention device, so that cold air is prevented from flowing back to enter the gas water heater when the ambient temperature is lower, and water in the heat exchanger is frozen to cause the water pipe of the heat exchanger to burst to cause potential safety hazards. In the anti-backflow device of the gas water heater, the anti-backflow plate is pivotally arranged on a support inside the smoke exhaust pipe, and the anti-backflow plate can be attached to the support after rotating to seal an internal channel of the smoke exhaust pipe. Because the anti-backflow plate and the support are both made of metal, the anti-backflow plate and the support are rigidly collided to generate abnormal sound when wind exists outside, and the user experience is poor.

At present, in order to solve the problem that abnormal sound is generated due to rigid collision between the backflow prevention plate and the support, a gasket, a washer and other soft buffer structures are usually additionally arranged between the backflow prevention plate and the support, but the overall structure cost and the assembly cost of the gas water heater are undoubtedly increased by the solution.

SUMMERY OF THE UTILITY MODEL

An object of the embodiment of the application is to provide a down draught prevention device, aim at solving the problem that down draught prevention device among the prior art avoids structural cost and assembly cost high that rigid collision produced between support and the down draught prevention plate.

The embodiment of the application is realized like this, a prevent down-draught device includes:

a pipe body, a first channel is formed inside the pipe body;

the bracket is arranged on the inner wall of the pipe body; and

the backflow preventing plate is rotatably arranged on the bracket;

the bracket is a flexible part, and when the backflow preventing plate rotates to be lapped on the bracket, the bracket and the backflow preventing plate are matched to seal the first channel.

In one embodiment, the bracket comprises a bearing part which is in a closed ring shape, and the outer edge of the backflow preventing plate can be lapped on the bearing part and is positioned between the inner edge and the outer edge of the bearing part.

In one embodiment, the bracket further comprises two oppositely arranged mounting parts, the mounting parts are connected to the outer edge of the end face of the bearing part, and the backflow preventing plate is rotatably mounted on the mounting parts.

In one embodiment, the radial width of the mounting portion is less than the radial width of the carrier portion.

In one embodiment, the inner wall of the tube body is expanded radially to form a mounting groove, and the bearing part is arranged in the mounting groove.

In one embodiment, the pipe body includes a first through body having a first end and a second through body having a second end, the first end and the second end are connected to each other, and the mounting groove is formed at the first end and/or the second end.

In one embodiment, the axial height of the bearing part is less than that of the mounting groove, and the sum of the axial height of the mounting part and the axial height of the bearing part is greater than or equal to that of the mounting groove.

In one embodiment, each of the mounting portions has a first mounting hole formed thereon, the anti-backflow device further includes a rotating shaft, two ends of the rotating shaft are respectively inserted into the first mounting holes of the mounting portions, and the anti-backflow plate is rotatably mounted on the rotating shaft.

In one embodiment, the anti-downdraft device further comprises a cross beam, wherein a clamping groove is formed in the inner side surface of the installation part, two ends of the cross beam are clamped in the clamping groove respectively, and two ends of the rotating shaft penetrate through the cross beam respectively.

In one embodiment, the bracket further comprises at least one bearing part, the bearing part is connected to the outer edge of the end face of the bearing part where the mounting part is located, and the sum of the axial height of the bearing part and the axial height of the bearing part is greater than or equal to the axial height of the mounting groove.

In one embodiment, the bracket is a flexible plastic, silicone or rubber member, and the bracket is an integrally formed member.

Another object of the embodiments of the present application is to provide a gas water heater, which includes the anti-downdraft device of the above embodiments.

The utility model provides a prevent down draught device and gas heater, its beneficial effect lies in:

the utility model provides a prevent down draught device, with the support mounting in the pipe body, and to prevent down draught plate and install on this support with rotating, and set up the support into the flexible piece, thus, because the support is the flexible piece, when preventing down draught plate rotation and directly patting on the support, not only can guarantee can not produce the abnormal sound because of the rigidity collision between support and the preventing down draught plate, and need not additionally to set up other gaskets, structures such as packing ring, the material, the structure cost is lower, the assembly is also more simple and convenient, be favorable to reducing down the overall cost who prevents down draught device. The embodiment of the application provides a gas heater, and it includes foretell anti-wind-back device, on the basis that can not produce the abnormal sound between support and the anti-wind-back plate, has lower material, structural cost and assembly cost.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings without creative efforts.

FIG. 1 is an angular perspective view of a device for preventing downdraft according to an embodiment of the present disclosure;

FIG. 2 is another perspective view of the anti-downdraft apparatus provided in the embodiments of the present application;

FIG. 3 is an exploded perspective view of a down draft prevention device provided in an embodiment of the present application;

FIG. 4 is a top view of a down draft prevention device provided by embodiments of the present application;

FIG. 5 is a cross-sectional view taken along line A-A of FIG. 3;

FIG. 6 is an enlarged view at C in FIG. 5;

FIG. 7 is a cross-sectional view taken along line B-B of FIG. 3, wherein the anti-backflow plate is in a closed state;

fig. 8 is another sectional view corresponding to fig. 7, wherein the anti-backflow plate is in an open state.

The designations in the figures mean:

100-anti-downdraft device;

1-a pipe body, 10-a first channel, 11-a first through body, 110-a first end, 111-a first step groove, 12-a second through body, 120-a second end, 121-a second step groove and 13-a mounting groove;

2-bracket, 20-second channel, 21-bearing part, 22-mounting part, 221-first mounting hole, 222-clamping groove, 23-bearing part;

3-beam, 31-second mounting hole;

4-a rotating shaft;

5-anti-backflow plate, 51-blade, 510-buckling part.

Detailed Description

In order to make the objects, technical solutions and advantages of the present application more apparent, the present application is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present application and are not intended to limit the present application.

It will be understood that when an element is referred to as being "secured to" or "disposed on" another element, it can be directly or indirectly secured to the other element. When an element is referred to as being "connected to" another element, it can be directly or indirectly connected to the other element. The terms "upper", "lower", "left", "right", and the like, indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description, but do not indicate or imply that the referred devices or elements must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the patent. The terms "first", "second" and "first" are used merely for descriptive purposes and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features. The meaning of "plurality" is two or more unless specifically limited otherwise.

In order to explain the technical solutions of the present application, the following detailed descriptions are made with reference to specific drawings and examples.

Referring to fig. 1 and 3, an anti-backflow device 100 according to an embodiment of the present disclosure includes a pipe 1, a bracket 2, and an anti-backflow plate 5. Specifically, the pipe body 1 is hollow in form, and a first passage 10 is formed inside thereof, as shown in fig. 5. The bracket 2 is installed on the inner wall of the pipe body 1, and the bracket 2 is formed with a second passage 20 corresponding to the first passage 10, and the first passage 10 and the second passage 20 are used for allowing air flow in the form of air, smoke, steam, etc. to pass through. After the stent 2 is installed on the inner wall of the tubular body 1, the first passage 10 is divided into two parts located at opposite sides of the stent 2. The backflow preventing plate 5 is rotatably mounted on the support 2, where the support 2 is a flexible member, and the backflow preventing plate 5 can rotate to overlap and attach to the end surface of the support 2, please refer to fig. 7, at this time, the backflow preventing plate 5 and the support 2 cooperate to seal the first channel 10, that is, two parts of the first channel 10 cannot be communicated with each other, and of course, at this time, the backflow preventing plate 5 also seals the second channel 20, and the airflow cannot pass through the pipe body 1; the backflow prevention plate 5 can also rotate to form a gap without being attached to the end surface of the bracket 2, please refer to fig. 8, at this time, the first channel 10 and the second channel 20 are both opened, and the two parts of the first channel 10 can be communicated, so that the air flow can pass through the pipe body 1.

In the anti-downdraft device 100 that this application embodiment provided, through installing support 2 in body 1, anti-downdraft plate 5 is installed on this support 2 rotatoryly, and set up support 2 into the flexible piece and anti-downdraft plate 5 rotates and beats on support 2, not only can guarantee that support 2 and anti-downdraft plate 5 between can not produce the abnormal sound because of the rigidity collision, and need not to set up other gaskets, structures such as packing ring, the material, the structure cost is lower, the assembly is also more simple and convenient, be favorable to reducing anti-downdraft device 100's overall cost.

Wherein, the bracket 2 may be a flexible plastic part, such as a PPS (polyphenylene sulfide) part; alternatively, the holder 2 may be a silicone member or a rubber member.

In order to realize the unidirectional air flow, the anti-backflow plate 5 is set to automatically return to the state of being attached to the end surface of the bracket 2 under the action of force so as to seal the first channel 10, and the anti-backflow plate 5 is opened by the pushing action of the air flow on the anti-backflow plate 5.

For example, in the present embodiment, the bracket 2 may be horizontally disposed, and the backflow preventing plate 5 rotates under its own gravity until the upper end surface of the bracket 2 is attached, as shown in fig. 7; when the air flow passes from bottom to top (in the direction of the dotted arrow in fig. 8), the backflow preventing plate 5 is pushed upwards to turn over, as shown in fig. 8. Of course, this is only an example, in other alternative embodiments, the end surface of the bracket 2 for abutting against the backflow preventing plate 5 may be a lower end surface thereof or a side surface inclined at another angle, and the backflow preventing plate 5 is automatically restored by the pulling force of an elastic member (such as a spring, an elastic strip) and the like. In practical applications, the automatic recovery mode of the backflow prevention plate 5 is selected and used according to a specific application scenario, and is not particularly limited herein.

Hereinafter, the above-described case in which the holder 2 is horizontally installed and the backflow preventing plate 5 is rotated by its own weight to be fitted to the upper end surface of the holder 2 will be described as an example.

Referring to fig. 1, 3 and 6, in one embodiment, the inner wall of the tube body 1 is recessed in a radially outward direction to form a mounting groove 13, and the bracket 2 is disposed in the mounting groove 13. This has the advantage that, on the one hand, the mounting groove 13 can be formed for quick positioning of the mounting of the support 2, improving the assembly efficiency, and, on the other hand, the lower end face of the support 2 can be at least partially supported on the lower side wall of the mounting groove 13, so that the support 2 can be partially or pre-fixed.

The tube body 1 may be a plastic part, and may be a hard plastic part, such as a PP (Polypropylene) tube, a PVC (polyvinyl chloride) tube, a melamine resin tube, or the like; the tube body 1 may also be a ceramic piece or a metal piece, such as a stainless steel tube. This is selected according to the specific use scenario of the anti-wind down device 100, for example, when the passing airflow is a high temperature airflow, a material capable of withstanding the high temperature may be selected accordingly. The examples are given herein by way of illustration only and are not intended to be limiting.

The pipe body 1 can be integrally formed, and can be respectively integrally injection-molded, dry-compression-molded, integrally punch-molded and the like according to different materials.

Alternatively, the pipe body 1 may be a separate structure. As shown in fig. 1 and 3, in one embodiment, the tubular body 1 comprises a first through body 11 and a second through body 12 connected to each other in an axial direction. The first through body 11 and the second through body 12 may be independently selected from a plastic part, a ceramic part or a metal part, and the first through body 11 and the second through body 12 may be respectively integrally formed, for example, the first through body 11 and the second through body 12 may be respectively integrally formed by injection molding, dry compression molding, integral punch forming, etc. according to different specific materials.

Referring to fig. 3, in the present embodiment, the first through body 11 has a first end 110 for connecting with the second through body 12, and the second through body 12 has a second end 120 for connecting with the second through body 12. Referring to fig. 6, the first end 110 is radially outwardly expanded to form a first stepped groove 111, the second end 120 is radially outwardly expanded to form a second stepped groove 121, and the second end 120 is inserted into the first stepped groove 111, such that the first end 110 and the second end 120 cooperate to form the mounting groove 13. Of course, the second end 120 is inserted into the first stepped groove 111 because the inner diameter of the first stepped groove 111 is greater than or equal to the outer diameter of the second stepped groove 121. Therefore, in other alternative embodiments, it is also possible that the inner diameter of second step groove 121 is greater than or equal to the outer diameter of first step groove 111, so that first end 110 is inserted into second step groove 121.

In addition, in some other alternative embodiments, the mounting groove 13 may be formed only at the first end 110, or only at the second end 120. The selection is specifically performed according to actual requirements, and is not particularly limited herein.

The first end 110 and the second end 120 are fixedly connected, such as welded, bonded, or screwed. Also can be selected according to specific requirements, and is not described and limited herein.

Referring to fig. 3 and 6, in one embodiment, the bracket 2 includes a bearing portion 21, the bearing portion 21 is in a closed ring shape, and the second channel 20 is formed on the bearing portion 21. The diameter of the backflow preventing plate 5 is smaller than the outer diameter of the bearing part 21 and larger than the inner diameter of the bearing part 21, so that when the backflow preventing plate 5 is flatly fitted on the end face of the bearing part 21, the outer edge of the backflow preventing plate 5 can be located between the outer edge and the inner edge of the bearing part 21, as shown in fig. 7. This has the advantage that, on the one hand, the anti-backflow plate 5 is ensured to completely close the second channel 20 of the bearing part 21, and, on the other hand, the outer edge of the anti-backflow plate 5 is not too close to the outer edge of the bearing part 21 and the bottom wall of the mounting groove 13, so that interference between the pipe body 1 and the anti-backflow plate 5 is prevented from affecting the rotation of the anti-backflow plate 5.

It should be understood that the above-mentioned "diameter of the backflow preventing plate 5" refers to the diameter of a circle of the end surface when it is in a flat state, that is, when it is attached to the upper end surface of the bearing part 21 (the backflow preventing plate 5 is in a closed state). Therefore, it should be noted that the cross-sections of the first and second passages 10 and 20 may be circular, and the backflow preventing plate 5 may be circular in the closed state. But not limited thereto, the cross-sections of the first and second passages 10, 20 may have other shapes such as an ellipse, etc., and the shape of the backflow preventing plate 5 in the closed state corresponds thereto. That is, regardless of the shape of the pipe body 1 and the first passage 10 thereof, the shape of the backflow preventing plate 5 is identical to the shape of the first passage 10 and the shape of the second passage 20, and the outer edge of the backflow preventing plate 5 may overlap between the outer edge and the inner edge of the upper end surface of the bearing part 21.

Referring to fig. 3 and 6, in an embodiment, the bracket 2 further includes a plurality of mounting portions 22, the mounting portions 22 are connected to an outer edge of the upper end surface of the supporting portion 21, the anti-backflow device 100 further includes a rotating shaft 4, the rotating shaft 4 is mounted between the mounting portions 22, and the anti-backflow plate 5 is rotatably mounted on the rotating shaft 4. Such a benefit is that the installation part 22 not only can fix and support the rotating shaft 4, but also makes the backflow preventing plate 5 and the rotating shaft 4 higher than the bearing part 21 in the horizontal direction, so that the end surface of the backflow preventing plate 5 facing the support 2 can be flatly attached to the upper end surface of the bearing part 21 of the support 2 without inclination, as shown in fig. 7, the attachment sealing performance between the backflow preventing plate 5 and the support 2 is ensured, and further, the anti-backflow effect is improved.

The shaft 4 may be selected to be a rigid member to provide rigid support to the anti-backflow plate 5 to ensure rotation of the anti-backflow plate 5. Specifically, the rotating shaft 4 may be a metal shaft, such as a stainless steel shaft; or the rotating shaft 4 is a ceramic shaft; alternatively, the rotating shaft 4 is a hard plastic shaft, specifically, a PP shaft, a PVC shaft, a melamine resin shaft, or the like. The selection is specifically made according to actual requirements, and is not particularly limited herein.

Specifically, in the present embodiment, the number of the mounting portions 22 is two, and the two mounting portions 22 are disposed oppositely, as shown in fig. 3.

Specifically, in the present embodiment, the first mounting hole 221 is formed in each mounting portion 22, and both ends of the rotating shaft 4 are inserted into the first mounting holes 221 of each mounting portion 22, respectively, so that the rotating shaft 4 is fixed and supported on the mounting portions 22, as shown in fig. 3 and 6.

The first mounting hole 221 may be a through hole, as shown in fig. 3. In other alternative embodiments, the first mounting hole 221 may be a blind hole, and the opening of the blind hole faces the inner side of the mounting portion 22.

In one embodiment, referring to fig. 3 and 6, the radial width of the mounting portion 22 (the width along the radial direction of the pipe body 1) is smaller than the radial width of the bearing portion 21, so that the mounting portion 22 does not affect the rotation of the backflow preventing plate 5, and further, the backflow preventing plate 5 is not affected to be tiled and lapped on the upper end surface of the bearing portion 21. That is, when the backflow preventing plate 5 is in the closed state, the outer peripheral surface of the backflow preventing plate 5 and the inner side surface of the mounting portion 22 can be in intimate contact or form a gap.

With continued reference to fig. 3 and 6, in one embodiment, the axial height of the bearing portion 21 (the height along the axial direction of the tube body 1, the same applies hereinafter) is smaller than the axial height of the mounting groove 13, and the sum of the axial height of the mounting portion 22 and the axial height of the bearing portion 21 is greater than or equal to the axial height of the mounting groove 13. This has the advantage that the mounting portion 22 can be snugly captured within the mounting slot 13 or even interference pressed within the mounting slot 13. From this, this support 2 can be installed in mounting groove 13 comparatively steadily, can need not other fixed connection modes, has simplified the installation of support 2 in body 1. Of course, in other alternative embodiments, other further fixing connection manners, such as adhesive connection, welding connection or clamping connection, may be provided between the bracket 2 and the mounting groove 13 according to specific needs, so as to improve the connection stability between the two.

In one embodiment, referring to fig. 2 and 3, the anti-wind-back device 100 further includes a cross beam 3, a locking groove 222 is disposed inside the mounting portion 22, two ends of the cross beam 3 are respectively locked in the locking groove 222, and the rotating shaft 4 is further mounted on the cross beam 3. Because the support 2 is a flexible part, the support may deform or deflect under the action of the airflow to press the rotating shaft 4, and the like, the rotating shaft 4 can be further supported by the cross beam 3 in the embodiment, and the flexible support 2 is prevented from having adverse effects on the rotating shaft 4.

The cross member 3 may be selected to be a rigid member to further provide rigid support to the shaft 4 and to the anti-backflow plate 5 to ensure rotation of the anti-backflow plate 5. In particular, the cross beam 3 may be a metal shaft, in particular a stainless steel shaft; or the cross beam 3 is a ceramic shaft; alternatively, the cross member 3 is a rigid plastic shaft, specifically, a PP shaft, a PVC shaft, a melamine resin shaft, or the like. The selection is specifically made according to actual requirements, and is not particularly limited herein.

As shown in fig. 3 and 6, the cross beam 3 is provided with a second mounting hole 31 corresponding to the first mounting hole 221, two ends of the rotating shaft 4 respectively penetrate through and protrude from the second mounting hole 31, and the second mounting hole 31 is a through hole.

In addition, referring to fig. 3 and 5, in an embodiment, the bracket 2 further includes at least one pressure-bearing portion 23, and the pressure-bearing portion 23 may be disposed with reference to the mounting portion 22 in terms of axial height, radial width and position, which is not described again. The advantage of this is that, have on this support 2 more than two positions by the installation, compress tightly in mounting groove 13, can guarantee the equilibrium of this support 2 installation, avoid the installation department 22 both sides to take place buckling deformation etc. further guarantee the laminating leakproofness between support 2 and the anti-backflow board 5.

Specifically, in the present embodiment, the pressure receiving portions 23 are two in number and are oppositely disposed on both sides of the two mounting portions 22. In this way, the two mounting portions 22 and the two pressure receiving portions 23 are substantially uniformly distributed in the mounting groove 13, and the mounting stability of the bracket 2 can be ensured. Of course, the number of the pressing portions 23 is only an example, and is not particularly limited, and in a specific application, the number and distribution of the pressing portions 23 may be comprehensively set according to the size of the bearing portion 21, the cost of the bonding process, and the like.

In the present embodiment, the bearing portion 21, the mounting portion 22 and the pressing portion 23 are integrally formed, that is, the bracket 2 is an integrally formed component.

Referring to fig. 3, in one embodiment, the anti-backflow plate 5 includes two blades 51 rotatably connected to the rotating shaft 4, respectively. The two blades 51 may be semicircular in shape so that the backflow preventing plate 5 is circular as shown in fig. 4. When the anti-backflow plate 5 is non-circular in flat shape, the two blades 51 are correspondingly shaped.

In this embodiment, as shown in fig. 3, at least one buckling portion 510 is formed at the edge of the straight edge of the blade 51, and the buckling portions 510 of the two blades 51 are staggered along the straight edge direction, so that the buckling portions of the two blades 51 can be clamped on the rotating shaft 4. In other alternative embodiments, the two blades 51 may be rotatably connected to the rotating shaft 4 by other manners, which are not limited herein.

In the present embodiment, the blade 51 is a rigid member to ensure that it can reliably abut against the end surface of the bearing portion 21 without generating a gap. Specifically, the blade 51 may be a metal member, such as a stainless steel member, and may be manufactured by integral punch forming or the like. In other alternative embodiments, the blade 51 may also be a ceramic or rigid plastic part, such as a PP part, a PVC part, a melamine resin part, and the like. It is understood that any material member capable of ensuring that the backflow preventing plate 5 has a suitable weight to be automatically restored by gravity and pushed away by the air flow can be applied thereto, and is not particularly limited.

Another object of the present embodiment is to provide a gas water heater (not shown), which includes the anti-downdraft device 100 of the above embodiments.

The embodiment of the application provides a gas water heater, its prevent that support 2 sets up to the flexible piece in the anti-wind device 100, and prevent that the anti-wind plate 5 rotates and the laminating is in order to seal body 1 on support 2, not only can guarantee that support 2 and prevent producing the abnormal sound because of the rigidity collision between the anti-wind plate 5, need not to set up other gaskets, gasket isotructures moreover, material, structure cost are lower, the assembly is also more simple and convenient, this gas water heater's overall cost is lower.

The specific structure of the gas water heater is not limited, and the gas water heater can be any gas water heater capable of being provided with the anti-downdraft device 100. For example, gas water heaters typically include: the air supply and exhaust device, the combustor, the heat exchanger, the water-gas linkage device, the control system and the like. The water-gas linkage device is used for detecting impact water pressure and controlling the opening and closing of a gas valve, the combustor is used for igniting gas and enabling the gas to be continuously combusted to generate heat, cold water flowing through the heat exchanger exchanges heat at the combustor, the air supply and exhaust device comprises a backflow prevention device 100, the pipe body 1 is a smoke exhaust pipe of the air supply and exhaust device, and smoke generated after gas combustion is exhausted from the smoke exhaust pipe.

In the gas water heater in this embodiment, the pipe of discharging fume is vertical to be set up, and the flue gas that produces after the gas combustion upwards discharges and promotes blade 51 and upwards overturn to prevent that backflow plate 5 opens, the flue gas can further be discharged. When no smoke passes through the smoke exhaust pipe, the blades 51 automatically return to the upper end face of the support 2 to be attached under the action of the self gravity, the first channel 10 is closed, and external air cannot flow back to enter the gas water heater.

The above description is only exemplary of the present application and should not be taken as limiting the present application, as any modification, equivalent replacement, or improvement made within the spirit and principle of the present application should be included in the protection scope of the present application.

Claims (12)

1. A down draft prevention device, comprising:

a pipe body, a first channel is formed inside the pipe body;

the bracket is arranged on the inner wall of the pipe body; and

the backflow preventing plate is rotatably arranged on the bracket;

the bracket is a flexible part, and when the backflow preventing plate rotates to be lapped on the bracket, the bracket and the backflow preventing plate are matched to seal the first channel.

2. The anti-downdraft device according to claim 1, wherein the bracket includes a bearing portion having a closed loop shape, wherein an outer edge of the anti-downdraft plate is adapted to overlap the bearing portion between an inner edge and an outer edge of the bearing portion.

3. The anti-downdraft device according to claim 2, wherein the bracket further comprises two oppositely disposed mounting portions connected to an outer edge of an end surface of the bearing portion, the anti-downdraft plate being rotatably mounted to the mounting portions.

4. The apparatus of claim 3, wherein a radial width of the mounting portion is less than a radial width of the bearing portion.

5. The anti-downdraft device according to claim 3, wherein an inner wall of the pipe body is expanded radially outward to form a mounting groove, and the bearing part is disposed in the mounting groove.

6. The anti-downdraft device according to claim 5, wherein the pipe body comprises a first through body having a first end and a second through body having a second end, the first end and the second end are connected to each other, and the mounting groove is formed at the first end and/or the second end.

7. The anti-downdraft device according to claim 5, wherein an axial height of the bearing portion is less than an axial height of the mounting groove, and a sum of the axial height of the mounting portion and the axial height of the bearing portion is greater than or equal to the axial height of the mounting groove.

8. The anti-downdraft device according to claim 3, wherein each of the mounting portions has a first mounting hole formed therein, the anti-downdraft device further comprising a rotating shaft having both ends inserted into the first mounting holes of the mounting portions, respectively, the anti-downdraft plate being rotatably mounted on the rotating shaft.

9. The anti-downdraft device according to claim 8, further comprising a cross beam, wherein a clamping groove is formed in the inner side surface of the mounting portion, two ends of the cross beam are respectively clamped in the clamping groove, and two ends of the rotating shaft respectively penetrate through the cross beam.

10. The anti-downdraft device according to claim 5, wherein the bracket further comprises at least one bearing portion, the bearing portion is connected to an outer edge of an end face of the bearing portion where the mounting portion is located, and the sum of the axial height of the bearing portion and the axial height of the bearing portion is greater than or equal to the axial height of the mounting groove.

11. The anti-downdraft device according to any one of claims 1 to 10, wherein the bracket is a flexible plastic, silicone or rubber member, and the bracket is an integrally formed member.

12. A gas water heater comprising the anti-downdraft apparatus of any one of claims 1 to 11.

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