Low-air-resistance air return valve and fan

Abstract

The air return valve comprises an air valve outer frame, a fixing frame is fixedly arranged at an air outlet of the air valve outer frame, non-return partition plates are evenly distributed on the fixing frame along the circumference, the rotating side of each non-return partition plate is fixedly connected with a rotating shaft in the radial direction, and the rotating shaft is fixedly connected with an air inlet of the air valve outer frame. The two ends of the rotating shaft are correspondingly connected to the fixing frame or the air valve outer frame and the fixing frame through bearings respectively. An angle limiting plate is fixedly arranged on a bearing seat of the bearing away from the axis of the fixing frame. According to the non-return air valve, the flowing angle of airflow can be close to or the same as the opening angle of the non-return partition plate, the resistance when the airflow flows out is greatly reduced, and the exhaust efficiency is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of check air return valves, in particular to a low-wind check air return valve and a fan. Background Art

[0002] In ventilation, smoke exhaust and other piping systems, in order to prevent backflow, a check valve needs to be installed in the piping system. When the fan is running, the air valve blades are open, and when the fan is stopped, the air valve blades are closed to prevent exhaust gas backflow. When the fan is running, the flow direction of the airflow is not parallel to the pipeline, but has a certain angle with the direction of the pipeline. However, in the existing check air valve, the opening angle of the check baffle is inconsistent with the flow angle of the airflow or is close to the same state. Therefore, the check baffle will bring certain resistance to the outflow of the airflow, reducing the ventilation efficiency. There may even be a situation where the exhaust volume design requirements cannot be met, and turbulence will be generated at the air outlet, causing the check baffle to vibrate and make noise, which is easy to cause damage to the rotating shaft and bearing seat of the check baffle.

[0003] When the non-return baffle relies on gravity to close the exhaust port, the edge of the non-return baffle will collide with the fixing frame, which will cause structural vibration and noise, and damage the non-return baffle and its connection structure. In addition, the existing air valve has poor sealing performance, and when negative pressure occurs at the exhaust port, it will cause airflow backflow, which greatly reduces the effect of airflow backflow prevention. Utility Model Content

[0004] The utility model aims to overcome the deficiencies of the prior art and provide a low wind stop return air valve and a fan to solve the problems of the prior art stop return air valve having large air flow resistance, poor sealing and large vibration when closed.

[0005] The utility model provides a low-wind return air valve, which includes: an air valve outer frame, a fixing frame fixedly provided at an air outlet of the air valve outer frame, at least three return check baffles evenly distributed along the circumference of the fixing frame, a rotating side of the return check baffle is radially fixedly connected to a rotating shaft, and both ends of the rotating shaft are respectively connected to the fixing frame or the air valve outer frame and the fixing frame through bearings; an angle limit plate is fixedly provided on the bearing seat of the bearing away from the axis of the fixing frame.

[0006] Furthermore, a sealing strip is provided at the outer circumference of the fixing frame, and the arc edge of the non-return baffle away from the axis of the fixing frame is in corresponding contact with the sealing strip; a sealing strip is provided along the circumference at the axis of the fixing frame, and the arc edge of the non-return baffle close to the axis of the fixing frame is in corresponding contact with the sealing strip.

[0007] Furthermore, the fixing frame is provided with equal amounts of angle limiting plates along the circumference close to the axis corresponding to the non-return partition.

[0008] Furthermore, the limiting angle of the angle limiting plate is 50-70°.

[0009] Furthermore, a filling cover plate is fixedly arranged on the outer side surface of the non-return partition.

[0010] Furthermore, the air valve outer frame is a straight cylinder structure or an inclined cylinder structure.

[0011] The utility model provides a low-wind return air valve, characterized in that the return air valve comprises: an air valve outer frame, two return air baffles are symmetrically arranged on the air valve outer frame, the rotating side of the return air baffle is radially fixedly connected with a rotating shaft, and the two ends of the rotating shaft are correspondingly connected to the air valve outer frame through bearings; an angle limit plate is fixedly arranged on the bearing seat that fixes the bearing.

[0012] Furthermore, a sealing strip is provided on the circumference of the outer frame of the air valve, and the outer arc edge of the non-return partition is in corresponding contact with the sealing strip.

[0013] The utility model provides a fan with a low-wind check air return valve, characterized in that the fan comprises the above-mentioned check air valve and a negative pressure fan, and the check air valve is correspondingly arranged at the air outlet of the negative pressure fan.

[0014] Furthermore, the fan also has a guide rib, and the guide rib is arranged between the air outlet of the negative pressure fan and the check air valve.

[0015] According to the above embodiments, the low-wind return air valve and the fan provided by the utility model have at least the following benefits: the return air valve can achieve an airflow angle close to or the same as the opening angle of the return baffle, greatly reducing the resistance of the airflow when it flows out, and improving the exhaust efficiency. In addition, the return air valve has a good sealing performance between the return baffle and the fixing frame by setting a sealing strip, reducing the possibility of backflow during negative pressure, and the sealing strip can avoid rigid contact between the return baffle and the fixing frame when the return baffle is closed, reducing vibration and noise, and extending the service life of the return baffle and its connecting structure.

[0016] The fan with the check air valve can realize rapid air supply and avoid backflow, thereby improving the air supply efficiency.

[0017] It should be understood that the above general description and the following specific embodiments are only exemplary and illustrative and are not intended to limit the scope of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The following drawings are a part of the specification of the present utility model, which illustrate exemplary embodiments of the present utility model. The attached drawings and the description of the specification are used to explain the principle of the present utility model.

[0019] Figure 1 This is a structural diagram of the first embodiment of the low-wind return air valve provided by the utility model.

[0020] Figure 2 A cross-sectional view of a first embodiment of a fan with a low-wind return air valve provided by the utility model.

[0021] Figure 3 This is a structural diagram of Embodiment 1 of a fan with a low-wind return air valve provided by the utility model.

[0022] Figure 4 This is an exploded view of the first embodiment of the fan with a low-wind return air valve provided by the utility model.

[0023] Figure 5 This is a cross-sectional view of the second embodiment of the fan with a low-wind return air valve provided by the utility model.

[0024] Figure 6 This is a structural diagram of the second embodiment of the low-wind return air valve provided by the utility model.

[0025] Figure 7 This is a cross-sectional view of the third embodiment of the fan with a low-wind return air valve provided by the utility model.

[0026] Figure 8 This is an exploded view of the third embodiment of the fan with a low wind return air valve provided by the utility model.

[0027] Fig. 9 This is a cross-sectional view of a fourth embodiment of a fan with a low-wind return air valve provided by the utility model.

[0028] Fig.10 This is a structural diagram of the third embodiment of the low-wind return air valve provided by the utility model.

[0029] Fig.11 This is a structural diagram of Embodiment 5 of a fan with a low-wind return air valve provided by the utility model.

[0030] Fig.12 This is a structural diagram of Example 6 of a fan with a low-wind return air valve provided by the utility model.

[0031] Fig.13 This is a structural diagram of a fourth embodiment of a low-wind return air valve provided by the utility model.

[0032] Fig.14 This is a structural diagram of Embodiment 7 of a fan with a low-wind return air valve provided by the utility model.

[0033] Fig.15 This is a structural diagram of Embodiment 8 of a fan with a low-wind return air valve provided by the utility model.

[0034] Fig.16 This is a structural diagram of Embodiment 5 of the low-wind return air valve provided by the utility model.

[0035] Fig.17 This is a structural diagram of Embodiment 9 of a fan with a low-wind return air valve provided by the utility model.

[0036] Fig.18 This is a structural diagram of the tenth embodiment of the fan with a low wind return air valve provided by the utility model.

[0037] Fig.19 This is a structural diagram of Example 6 of the low-wind return air valve provided by the utility model.

[0038] Fig. 20 This is a structural diagram of the eleventh embodiment of the fan with a low-wind return air valve provided by the utility model.

[0039] Fig.21 This is a structural diagram of the twelfth embodiment of the fan with a low-wind return air valve provided by the utility model.

[0040] Fig. 22 This is a structural diagram of Embodiment 7 of the low-wind return air valve provided by the utility model.

[0041] Fig.23 This is a structural diagram of the thirteenth embodiment of the fan with a low wind speed return air valve provided by the utility model.

[0042] Fig.24 This is a structural diagram of a fourteenth embodiment of a fan with a low-wind return air valve provided by the utility model.

[0043] Fig.25 This is a structural diagram of Embodiment 8 of the low-wind return air valve provided by the utility model.

[0044] Fig.26 This is a structural diagram of the fifteenth embodiment of the fan with a low wind return air valve provided by the utility model.

[0045] Fig. 27 This is a structural diagram of a sixteenth embodiment of a fan with a low-wind return air valve provided by the utility model.

[0046] Fig.28 This is a structural diagram of Embodiment 9 of the low-wind return air valve provided by the utility model.

[0047] Fig.29 This is a structural diagram of embodiment 17 of a fan with a low-wind return air valve provided by the utility model.

[0048] Fig.30 This is a structural diagram of the eighteenth embodiment of the fan with a low wind return air valve provided by the utility model.

[0049] Fig.31 This is a structural diagram of the tenth embodiment of the low-wind return air valve provided by the utility model.

[0050] Fig.32 This is a structural diagram of the nineteenth embodiment of the fan with a low wind return air valve provided by the utility model.

[0051] Fig.33 This is a structural diagram of Example 20 of a fan with a low-wind return air valve provided by the utility model.

[0052] Description of reference numerals:

[0053] 1-air valve frame, 2-fixed frame, 3-check baffle, 4-rotating shaft, 5-bearing, 6-angle limit plate, 7-sealing strip, 8-filling cover, 9-door closer, 10-negative pressure fan, 11-guide rib, 12-fan casing, 13-motor, 14-impeller. DETAILED DESCRIPTION

[0054] Various exemplary embodiments of the present invention are now described in detail. This detailed description should not be considered as limiting the present invention, but should be understood as a more detailed description of certain aspects, features and embodiments of the present invention.

[0055] It will be apparent to those skilled in the art that various modifications and variations may be made to the specific embodiments of the present invention without departing from the scope or spirit of the present invention. Other embodiments derived from the present invention will be apparent to those skilled in the art. The present application description and examples are merely exemplary.

[0056] The utility model provides a low wind blocking return air valve, such as Figure 1 The figure shows a schematic diagram of the overall structure of the first embodiment of the check air valve. In a specific implementation, the check air valve includes: an air valve outer frame 1. In this embodiment, the air valve outer frame 1 is an inclined cylinder structure, and the air inlet plane and the air outlet plane have an acute angle. And the air outlet of the air valve outer frame 1 is circular. A fixing frame 2 is fixedly provided at the air outlet of the air valve outer frame 1, and five check baffles 3 are evenly distributed along the circumference on the fixing frame 2, and each check baffle 3 has the same size. The rotating side of the check baffle 3 is fixedly connected to a rotating shaft 4 in the radial direction, and the two ends of the rotating shaft 4 are respectively connected to the fixing frame 2 or the air valve outer frame 1 and the fixing frame 2 through bearings 5.

[0057] In addition, an angle limit plate 6 is fixedly provided on the bearing seat of the bearing 5 away from the axis of the fixed frame 2, which is used to limit the opening angle of each check baffle 3 so that its maximum opening angle is the same as the angle of the flow direction of the airflow, thereby reducing the airflow resistance.

[0058] In a specific implementation of the utility model, a sealing strip 7 is provided at the outer circumference of the fixing frame 2, which corresponds to each non-return baffle 3 and is located at the lower part of the non-return baffle 3, and the arc edge of the non-return baffle 3 away from the axis of the fixing frame 2 contacts with the sealing strip 7.

[0059] A sealing strip 7 is provided along the circumference of the axis of the fixing frame 2, and the arc edge of the non-return baffle 3 near the axis of the fixing frame 2 is in contact with the sealing strip 7. The sealing strip can not only achieve a sealing effect to prevent the airflow from flowing back from the gap, but also avoid rigid contact when the non-return baffle 3 is closed, reducing the vibration caused by closing.

[0060] In a specific implementation manner of the utility model, the limiting angle of the angle limiting plate 6 is 50-70°. In this embodiment, since the airflow is rotating due to the rotation of the fan blades, the airflow direction is not perpendicular to the outlet plane when the air flows out of the outlet of the non-return air valve, and therefore the non-return baffle is not perpendicular to the outlet plane when it is opened. Therefore, an angle limiting plate is required to limit the opening angle of the non-return baffle 3. In this embodiment, the opening angle is 50-70°. In addition, since the air inlet plane and the air outlet plane of the non-return air valve are not in the same plane, the angles of each non-return baffle in this embodiment are not the same when they are opened. This is to ensure that the angle of the airflow flowing out of each non-return baffle 3 is close to or the same as the opening angle of the corresponding non-return baffle 3, so as to reduce wind resistance and improve ventilation efficiency.

[0061] In the specific implementation of the utility model, the non-return partition can generally fall back by gravity. In order to ensure the closing effect of the non-return partition 3, a door closer 9 is provided on the non-return air valve, and the fixed end of the door closer 6 is fixed on the outer surface of the non-return partition 3, and the other end of the door closer 9 extends to the outer surface of the adjacent non-return partition 3 and can press the non-return partition 3.

[0062] Generally, the number of door closers 9 is two less than the number of non-return partitions, and they are arranged on the non-return partitions 3 adjacent to the non-return partitions that are difficult to close by gravity. In this embodiment, three door closers 9 are arranged.

[0063] In the specific implementation of the utility model, a filling cover plate 8 is fixedly arranged on the outer side of the check partition 3 to make the outer surface of the check partition 3 smooth and avoid dust accumulation. In addition, the filling cover plate 8 is made of a lightweight filling material, which has little effect on the deadweight of the check partition 3.

[0064] like Figure 6 The figure shows the structure of the second embodiment of the low wind return air valve provided by the utility model. Figure 1The difference of the embodiment shown is that, in this embodiment, the air valve outer frame 1 is a straight cylinder structure, that is, the air inlet plane and the air outlet plane are parallel. And the fixed frame 2 is provided with equal number of angle limit plates 6 along the circumference corresponding to the non-return partition 3 near the axis. The angle limit plates 6 at this position cooperate with the angle limit plates 6 at the outer circle position of the non-return partition 3 to limit the maximum opening angle of the non-return partition 3.

[0065] Since the air inlet plane and the air outlet plane of the non-return air valve are parallel, the angles at which the air flows out from each non-return baffle are the same, and the opening angles of each non-return baffle 3 are also the same.

[0066] In addition, in this embodiment, the non-return air valve is arranged in a vertical direction, so the non-return partition 3 can be closed completely by gravity, and there is no need to provide a door closer 9.

[0067] like Fig.10 The structure diagram of the low wind return air valve provided by the utility model is shown. Figure 1 The difference of the embodiment shown is that, in this embodiment, the number of the non-return baffles 3 is 4, which are evenly distributed at the air outlet. In addition, in this embodiment, two door closers 9 are provided.

[0068] like Fig.13 The structure diagram of the fourth embodiment of the low wind return air valve provided by the utility model is shown. Figure 6 The difference of the illustrated embodiment is that, in this embodiment, the number of the non-return baffles 3 is 4, which are evenly distributed at the air outlet.

[0069] like Fig.16 The figure shows the structure of the fifth embodiment of the low wind return air valve provided by the utility model. Figure 1 The difference of the embodiment shown is that, in this embodiment, the number of the non-return baffles 3 is 3, which are evenly distributed at the air outlet. In addition, in this embodiment, a door closer 9 is provided.

[0070] like Fig.19 The figure shows the structure of the sixth embodiment of the low wind return air valve provided by the utility model. Figure 6 The difference of the illustrated embodiment is that, in this embodiment, the number of the non-return baffles 3 is 3, which are evenly distributed at the air outlet.

[0071] like Fig. 22The structure diagram of the seventh embodiment of the low-wind return air valve provided by the utility model is shown. In a specific implementation, the return air valve comprises: an air valve outer frame 1. In this embodiment, the air valve outer frame 1 is an inclined cylinder structure, and the air inlet plane and the air outlet plane have an acute angle. Two return baffles 3 are symmetrically arranged on the air valve outer frame 1. The rotating side of the return baffle 3 is fixedly connected with a rotating shaft 4 in the radial direction, and the two ends of the rotating shaft 4 are correspondingly connected to the air valve outer frame 1 through bearings 5.

[0072] An angle limit plate 6 is fixedly arranged on the bearing seat of the fixed bearing 5, which is used to limit the opening angle of each non-return baffle 3 so that its maximum opening angle is the same as the angle of the flow direction of the airflow, thereby reducing the wind resistance of the airflow. In this embodiment, the maximum opening angle of the non-return baffle 3 is 90°.

[0073] Furthermore, a sealing strip 7 is provided at the circumferential position of the air valve outer frame 1, and the outer arc edge of the non-return baffle 3 is in corresponding contact with the sealing strip 7. The sealing strip 7 can not only achieve a sealing effect to prevent the airflow from flowing back from the gap, but also avoid rigid contact when the non-return baffle 3 is closed, thereby reducing the vibration caused by closing.

[0074] In the specific implementation of this embodiment, a filling cover plate 8 is fixedly arranged on the outer side of the check partition 3 to make the outer surface of the check partition 3 flat and avoid dust accumulation. In addition, the filling cover plate 8 is made of a lightweight filling material, which has little effect on the deadweight of the check partition 3.

[0075] like Fig.25 The figure shows the structure of the eighth embodiment of the low wind return air valve provided by the utility model. Fig. 22 The difference of the embodiment shown is that, in this embodiment, the air valve outer frame 1 is a straight cylinder structure, that is, the air inlet plane and the air outlet plane are parallel. And the fixed frame 2 is provided with equal number of angle limit plates 6 along the circumference corresponding to the non-return partition 3 near the axis. The angle limit plates 6 at this position cooperate with the angle limit plates 6 at the outer circle position of the non-return partition 3 to limit the maximum opening angle of the non-return partition 3.

[0076] like Fig.28 The figure shows the structure of the ninth embodiment of the low wind return air valve provided by the utility model. Figure 1 The difference of the embodiment shown is that, in this embodiment, the number of the non-return baffles 3 is 6, which are evenly distributed at the air outlet. In addition, in this embodiment, 3 door closers 9 are provided.

[0077] like Fig.31 The figure shows the structure of the tenth embodiment of the low wind return air valve provided by the utility model. Figure 6 The difference of the illustrated embodiment is that, in this embodiment, the number of the non-return baffles 3 is 6, which are evenly distributed at the air outlet.

[0078] The utility model also provides a fan with a low wind stopping return air valve, such as Figure 5 FIG. 1 is a schematic diagram of the structure of the second embodiment of the fan with a non-return air valve. In a specific embodiment, the fan with the non-return air valve includes: Figure 1 In the illustrated embodiment, the check valve and the negative pressure fan 10 are arranged such that the check valve is correspondingly arranged at the air outlet of the negative pressure fan 10, and the negative pressure fan 10 is arranged horizontally.

[0079] In this embodiment, the air valve outer frame 1 of the non-return air valve is an inclined cylinder structure, and the air inlet plane and the air outlet plane have an acute angle. A fixing frame 2 is fixedly arranged at the air outlet of the air valve outer frame 1, and 5 non-return baffles 3 are evenly distributed along the circumference on the fixing frame 2, and each non-return baffle 3 has the same size.

[0080] In this embodiment, the non-return partition can generally fall back by gravity. In order to ensure the closing effect of the non-return partition 3, a door closer 9 is provided on the non-return air valve. The fixed end of the door closer 6 is fixed on the outer surface of the non-return partition 3, and the other end of the door closer 9 extends to the outer surface of the adjacent non-return partition 3 and can press the non-return partition 3. Three door closers 9 are provided.

[0081] The negative pressure fan 10 includes a fan housing 12, a motor 13 and an impeller 14. The fan housing 12 has two openings at both ends, which are an air inlet end and an air outlet end. The motor 13 is fixedly connected to the inside of the fan housing 12 through a motor bracket, and the impeller 14 is fixed to the rotating shaft of the motor 13, facing the air outlet end of the fan housing 12. In addition, the air valve outer frame 1 of the check air valve is fixedly connected to the air outlet end of the fan housing 12.

[0082] like Figure 2-4 The figure shows a schematic diagram of the structure of a fan embodiment 1 of a low wind return air valve provided by the utility model. Figure 5 The difference of the illustrated embodiment is that, in this embodiment, the fan also has a guide rib 11, which is arranged between the air outlet of the negative pressure fan 10 and the check valve and is fixedly connected by fasteners. The guide rib 11 is used to guide the airflow and reduce the occurrence of airflow turbulence.

[0083] like Figure 7 and 8 The figure shows a schematic diagram of the structure of a fan embodiment 3 of a low wind return air valve provided by the utility model. Figure 2-4The difference of the embodiment shown is that, in this embodiment, the negative pressure fan 10 is placed vertically, and the air valve outer frame 1 is a straight cylinder structure, that is, the air inlet plane and the air outlet plane are parallel. And the fixed frame 2 is provided with equal number of angle limit plates 6 along the circumference corresponding to the non-return baffle 3 near the axis. The angle limit plates 6 at this position cooperate with the angle limit plates 6 at the outer circle position of the non-return baffle 3 to limit the maximum opening angle of the non-return baffle 3.

[0084] Since the air inlet plane and the air outlet plane of the non-return air valve are parallel, the angles at which the air flows out from each non-return baffle are the same, and the opening angles of each non-return baffle 3 are also the same.

[0085] In addition, in this embodiment, the non-return air valve is arranged in a vertical direction, so the non-return partition 3 can be closed completely by gravity, and there is no need to provide a door closer 9.

[0086] like Fig. 9 The figure shows a schematic diagram of the structure of a fan embodiment 4 with a low wind speed return air valve provided by the utility model. Figure 7 and Figure 8 The difference of the illustrated embodiment is that, in this embodiment, no guide rib 11 is provided between the negative pressure fan 10 and the check air valve.

[0087] like Fig.11 The figure shows a schematic diagram of the structure of a fifth embodiment of a fan with a low wind return air valve provided by the utility model. Figure 2-4 The difference of the illustrated embodiment is that, in this embodiment, the number of the non-return baffles 3 is 4, which are evenly distributed at the air outlet.

[0088] like Fig.12 The figure shows a schematic diagram of the structure of a sixth embodiment of a fan with a low wind return air valve provided by the utility model. Figure 5 The difference of the illustrated embodiment is that, in this embodiment, the number of the non-return baffles 3 is 4, which are evenly distributed at the air outlet.

[0089] like Fig.14 The figure shows a structural schematic diagram of a fan embodiment 7 of a low wind return air valve provided by the utility model. Figure 7 and 8 The difference of the illustrated embodiment is that, in this embodiment, the number of the non-return baffles 3 is 4, which are evenly distributed at the air outlet.

[0090] like Fig.15 The figure shows a schematic diagram of the structure of an embodiment 8 of a fan with a low wind speed return air valve provided by the utility model. Fig. 9 The difference of the illustrated embodiment is that, in this embodiment, the number of the non-return baffles 3 is 4, which are evenly distributed at the air outlet.

[0091] like Fig.17 The figure shows a schematic diagram of the structure of a fan embodiment 9 with a low wind speed return air valve provided by the utility model. Figure 2-4 The difference of the illustrated embodiment is that, in this embodiment, the number of the non-return baffles 3 is 3, which are evenly distributed at the air outlet.

[0092] like Fig.18 The figure shows a schematic diagram of the structure of a fan embodiment 10 with a low wind return air valve provided by the utility model. Figure 5 The difference of the illustrated embodiment is that, in this embodiment, the number of the non-return baffles 3 is 3, which are evenly distributed at the air outlet.

[0093] like Fig. 20 The figure shows a schematic diagram of the structure of a fan embodiment 11 with a low wind speed return air valve provided by the utility model. Figure 7 and 8 The difference of the illustrated embodiment is that, in this embodiment, the number of the non-return baffles 3 is 3, which are evenly distributed at the air outlet.

[0094] like Fig.21 The figure shows a schematic diagram of the structure of a fan embodiment 12 of a low wind return air valve provided by the utility model. Fig. 9 The difference of the illustrated embodiment is that, in this embodiment, the number of the non-return baffles 3 is 3, which are evenly distributed at the air outlet.

[0095] like Fig.23 The figure shows a schematic diagram of the structure of a fan embodiment 13 of a low wind return air valve provided by the utility model. Figure 2-4 The difference of the embodiment shown is that in this embodiment, the non-return air valve is Fig. 22 The non-return air valve in the illustrated embodiment comprises: an air valve outer frame 1, in this embodiment, the air valve outer frame 1 is an inclined cylinder structure, and the air inlet plane and the air outlet plane have an acute angle. Two non-return baffles 3 are symmetrically arranged on the air valve outer frame 1, and the rotating side of the non-return baffle 3 is fixedly connected with a rotating shaft 4 in the radial direction, and the two ends of the rotating shaft 4 are correspondingly connected to the air valve outer frame 1 through bearings 5.

[0096] An angle limit plate 6 is fixedly arranged on the bearing seat of the fixed bearing 5, which is used to limit the opening angle of each non-return baffle 3 so that its maximum opening angle is the same as the angle of the flow direction of the airflow, thereby reducing the wind resistance of the airflow. In this embodiment, the maximum opening angle of the non-return baffle 3 is 90°.

[0097] Furthermore, a sealing strip 7 is provided at the circumferential position of the air valve outer frame 1, and the outer arc edge of the non-return baffle 3 is in corresponding contact with the sealing strip 7. The sealing strip 7 can not only achieve a sealing effect to prevent the airflow from flowing back from the gap, but also avoid rigid contact when the non-return baffle 3 is closed, thereby reducing the vibration caused by closing.

[0098] In addition, in this embodiment, the two non-return partitions 3 can be closed completely by gravity, and there is no need to provide a door closer 9.

[0099] like Fig.24 The figure shows a schematic diagram of the structure of a fan embodiment 14 with a low wind return air valve provided by the utility model. Fig.23 The difference of the illustrated embodiment is that, in this embodiment, no guide rib 11 is provided between the negative pressure fan 10 and the check air valve.

[0100] like Fig.26 The figure shows a structural schematic diagram of a fan embodiment 15 of a low wind return air valve provided by the utility model. Fig.23 The difference of the embodiment shown is that, in this embodiment, the negative pressure fan 10 is placed vertically, and the air valve outer frame 1 is a straight cylinder structure, that is, the air inlet plane and the air outlet plane are parallel. And the fixed frame 2 is provided with equal number of angle limit plates 6 along the circumference corresponding to the non-return baffle 3 near the axis. The angle limit plates 6 at this position cooperate with the angle limit plates 6 at the outer circle position of the non-return baffle 3 to limit the maximum opening angle of the non-return baffle 3.

[0101] like Fig. 27 The figure shows a schematic diagram of the structure of a sixteenth embodiment of a fan with a low wind return air valve provided by the utility model. Fig.26 The difference of the illustrated embodiment is that, in this embodiment, no guide rib 11 is provided between the negative pressure fan 10 and the check air valve.

[0102] like Fig.29 The figure shows a structural schematic diagram of a fan embodiment 17 of a low wind return air valve provided by the utility model. Figure 2-4 The difference of the illustrated embodiment is that, in this embodiment, the number of the non-return baffles 3 is 6, which are evenly distributed at the air outlet.

[0103] like Fig.30 The figure shows a schematic diagram of the structure of a fan embodiment 18 with a low wind speed return air valve provided by the utility model. Figure 5 The difference of the illustrated embodiment is that, in this embodiment, the number of the non-return baffles 3 is 6, which are evenly distributed at the air outlet.

[0104] like Fig.32 The figure shows a structural schematic diagram of a fan embodiment 19 of a low wind return air valve provided by the utility model. Figure 7 and 8 The difference of the illustrated embodiment is that, in this embodiment, the number of the non-return baffles 3 is 6, which are evenly distributed at the air outlet.

[0105] like Fig.33 The figure shows a schematic diagram of the structure of a fan embodiment 20 with a low wind return air valve provided by the utility model. Fig. 9 The difference of the illustrated embodiment is that, in this embodiment, the number of the non-return baffles 3 is 6, which are evenly distributed at the air outlet.

[0106] The above description is only an illustrative specific implementation of the present invention. Without departing from the concept and principle of the present invention, any equivalent changes and modifications made by those skilled in the art should fall within the scope of protection of the present invention.

Claims

1. A low wind return air valve, characterized in that: The non-return air valve comprises: an air valve outer frame (1), a fixing frame (2) fixedly arranged at the air outlet of the air valve outer frame (1), at least three non-return baffles (3) evenly distributed along the circumference of the fixing frame (2), a rotating side of the non-return baffle (3) fixedly connected to a rotating shaft (4) in the radial direction, and two ends of the rotating shaft (4) correspondingly connected to the fixing frame (2) or the air valve outer frame (1) and the fixing frame (2) through bearings (5); An angle limiting plate (6) is fixedly arranged on the bearing seat of the bearing (5) away from the axis of the fixing frame (2).

2. The low wind blocking return air valve according to claim 1, characterized in that: A sealing strip (7) is provided at the outer circumference of the fixing frame (2), and the arc-shaped edge of the non-return baffle (3) away from the axis of the fixing frame (2) is in corresponding contact with the sealing strip (7); A sealing strip (7) is arranged along the circumference at the axis of the fixing frame (2), and the arc-shaped edge of the non-return partition (3) close to the axis of the fixing frame (2) is in corresponding contact with the sealing strip (7).

3. The low wind blocking return air valve according to claim 1, characterized in that: The fixing frame (2) is provided with equal amounts of angle limiting plates (6) along the circumference corresponding to the non-return partition plate (3) near the axis.

4. The low wind blocking return air valve according to claim 3, characterized in that: The limiting angle of the angle limiting plate (6) is 50-70°.

5. The low wind blocking return air valve according to claim 1, characterized in that: A filling cover plate (8) is fixedly arranged on the outer side surface of the non-return partition plate (3).

6. The low wind blocking return air valve according to claim 1, characterized in that: The air valve outer frame (1) is a straight cylinder structure or an inclined cylinder structure.

7. A low wind return air valve, characterized in that: The non-return air valve comprises: an air valve outer frame (1), the air valve outer frame (1) being symmetrically provided with two non-return baffles (3), the rotating side of the non-return baffle (3) being fixedly connected to a rotating shaft (4) in a radial direction, and the two ends of the rotating shaft (4) being correspondingly connected to the air valve outer frame (1) via bearings (5); An angle limiting plate (6) is fixedly arranged on the bearing seat for fixing the bearing (5).

8. The low wind blocking return air valve according to claim 7, characterized in that: A sealing strip (7) is provided at a circumferential position of the air valve outer frame (1), and the outer arc edge of the non-return partition (3) is in corresponding contact with the sealing strip (7).

9. A fan with a low wind stop return air valve, characterized in that: The fan comprises a non-return air valve as described in any one of claims 1 to 8 and a negative pressure fan (10), wherein the non-return air valve is correspondingly arranged at the air outlet of the negative pressure fan (10).

10. The fan with a low wind speed preventing return air valve according to claim 9, characterized in that: The fan also has a guide rib (11), and the guide rib (11) is arranged between the air outlet of the negative pressure fan (10) and the check valve.

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