A check valve for a range hood

Abstract

The application discloses an anti-return valve for a range hood, which comprises a valve body, a first valve piece, a second valve piece and an opening and maintaining mechanism; a first shaft body is fixedly arranged in the valve body; the first valve piece and the second valve piece are symmetrically hinged to the first shaft body; a second shaft body is arranged above the first shaft body and can slide up and down on the valve body; a first connecting rod is hinged between the first valve piece and the second shaft body; a second connecting rod is hinged between the second valve piece and the second shaft body; the opening and maintaining mechanism comprises an elastic assembly and a constraint assembly; one end of the elastic assembly is connected with the first valve piece and the other end is connected with the constraint assembly. When the first valve piece and the second valve piece are turned over and opened, the elastic assembly is compressed and generates an elongation force, the first valve piece is pulled by a guide rod to maintain the open state; after the range hood is closed, the constraint assembly is released from the limiting, the elastic assembly releases the energy, and the valve pieces fall back under the action of gravity. The application realizes the synchronous opening of the double valve pieces and avoids the increase of the smoke exhaust resistance and the noise.

Description

Technical Field

[0001] This application relates to the field of kitchen appliance technology, and in particular to a check valve for a range hood. Background Technology

[0002] During cooking, the range hood draws in cooking fumes and exhausts them into the shared flue through its vent. To prevent fumes from flowing back into the room when the range hood is not in use, a backflow preventer is usually installed at the range hood's vent or at the connection point to the shared flue.

[0003] Existing check valves generally consist of a valve body and a valve disc that is movable within the valve body. When the range hood is working, the airflow of cooking fumes pushes the valve disc to open; when the range hood stops working, the valve disc returns to its original position and closes due to its own weight or spring force. To increase ventilation area and reduce air resistance, some check valves adopt a dual-valve disc structure, with two valve discs symmetrically arranged and rotating around their respective axes.

[0004] However, existing dual-valve check valves have the following problems in practical use: The two valve plates rotate independently. Due to uneven airflow distribution within the valve body and inconsistent adhesion of grease to the valve plates, one valve plate often opens first, while the other fails to open or opens later. Once one valve plate opens first, the pressure difference across the valve plate decreases after the airflow passes through it, making it even more difficult for the unopened valve plate to open. This results in the check valve remaining in a single-valve-open state for an extended period, increasing exhaust resistance and reducing the effectiveness of fume extraction. Furthermore, when airflow passes through only one side, the flow cross-section decreases, increasing airflow velocity and creating vortices and turbulence at the valve plate edges, generating additional wind noise. Simultaneously, the motor load of the range hood increases, leading to a corresponding increase in operating noise. Summary of the Invention

[0005] The purpose of this application is to provide a check valve for range hoods to solve the problems mentioned in the background art.

[0006] To achieve the above objectives, this application provides the following technical solution: A check valve for a range hood includes a valve body, a first valve plate, a second valve plate, and an opening and holding mechanism; The valve body is fixedly provided with a first shaft, and the first valve plate and the second valve plate are symmetrically hinged on the first shaft. The first valve plate and the second valve plate rotate around the first shaft. A second shaft parallel to the first shaft is provided above the first shaft, and the second shaft is slidably mounted on the valve body. A first connecting rod is hinged between the first valve plate and the second shaft, and a second connecting rod is hinged between the second valve plate and the second shaft; The opening and holding mechanism is connected to the first valve plate; The first valve plate and the second valve plate are rotated and opened around the first axis under the action of airflow. When they are rotated into place, the opening and holding mechanism applies a holding force to the first valve plate, so that the first valve plate and the second valve plate remain in the open state.

[0007] In some embodiments, one end of the second connecting rod sleeved on the second shaft has a U-shaped structure, and one end of the first connecting rod sleeved on the second shaft is clamped in the U-shaped structure, with the second shaft passing through both the U-shaped structure and the first connecting rod.

[0008] In some embodiments, the opening and holding mechanism includes an elastic component and a constraint component; one end of the elastic component is connected to the first valve plate, and the other end is connected to the constraint component. After the first valve plate and the second valve plate are flipped into place, the constraint component cooperates with the elastic component to keep the first valve plate and the second valve plate in the open state.

[0009] In some embodiments, a third shaft is further included, which is arranged parallel to the first shaft; The elastic component includes a guide rod, a rocker arm, and a spring. The peripheral wall of the guide rod extends radially outward to form an annular boss, which divides the guide rod into a first segment and a second segment. The second segment of the guide rod is rotatably connected to the first valve plate. One end of the rocker arm is rotatably connected to the third shaft, and the other end is provided with a cavity. The cavity has an opening, and the first segment of the guide rod slidably extends into the cavity through the opening. The spring is sleeved on the first segment of the guide rod, with one end connected to the edge of the opening and the other end connected to the annular boss. When the first valve plate and the second valve plate flip, the guide rod gradually extends into the cavity of the swing rod, and the guide rod and the swing rod swing toward the second valve plate. The spring is compressed, and the elongation force of the spring causes the guide rod to pull the first valve plate, maintaining the first valve plate and the second valve plate in the open state.

[0010] In some embodiments, the constraint assembly includes a support, a push rod, and a drive member. The third shaft is fixedly mounted on the support, the push rod abuts against the support through a beveled structure, and the output end of the drive member is connected to the push rod. After the range hood is turned off, the driving component drives the push rod to move horizontally away from the support, releasing the support from its limit position. The spring drives the third shaft to move upward. The spring returns from a compressed state to a free state, and the first valve plate and the second valve plate fall under the action of gravity. When the first valve plate and the second valve plate fall to the set position, the driving component drives the push rod to move horizontally towards the support, pushing the support to reset.

[0011] In some embodiments, the inclined structure includes a first inclined surface and a second inclined surface. The first inclined surface is disposed at one end of the push rod facing the support, and the second inclined surface is disposed at one end of the support facing the push rod. The first inclined surface and the second inclined surface have the same inclination direction and fit together.

[0012] In some embodiments, a connector is fixedly provided on the first valve plate, and a fourth shaft is provided on the connector. The fourth shaft is arranged parallel to the first shaft, and one end of the guide rod is rotatably connected to the fourth shaft.

[0013] In some embodiments, the second valve plate is provided with a clearance space for avoiding the connecting member.

[0014] In some embodiments, the system further includes a bracket with an opening extending upward from the bottom of the bracket. Two opposite sidewalls of the opening are provided with first slide rails, and the two ends of the second shaft are slidably disposed in the corresponding first slide rails.

[0015] In some embodiments, the bracket is further provided with a second slide rail, which is located below the first slide rail, and the support is slidably disposed in the second slide rail.

[0016] The technical solutions provided in this application have the following advantages compared with the prior art: The first valve plate is connected to the first connecting rod, and the second valve plate is connected to the second shaft via the second connecting rod. When the airflow pushes the first and second valve plates to rotate and open around the first shaft, the first and second connecting rods simultaneously drive the second shaft to slide upward along the first slide rail, ensuring that the opening angle of the two valve plates remains consistent. This achieves synchronous opening of both valve plates, avoiding airflow turbulence, increased smoke exhaust resistance, and increased noise caused by the opening of a single valve plate. It effectively maintains smooth ventilation of the smoke hood, reduces pressure loss, and improves energy efficiency.

[0017] As the valve plate flips, the guide rod gradually extends into the cavity of the swing rod. The guide rod and the swing rod swing towards the second valve plate, and the spring is compressed. The elongation force of the spring causes the guide rod to pull the first valve plate, maintaining the valve plate in the open state and preventing the valve plate from vibrating due to airflow fluctuations, thereby reducing noise.

[0018] The push rod and the support are engaged and abutted by an inclined plane structure. The drive component only needs to move the push rod horizontally to control the raising and lowering of the support, eliminating the need for a complex transmission mechanism. The structure is simple and the operation is reliable. The inclined plane engagement has a self-locking characteristic, ensuring that the support remains stable after the push rod is in place. Attached Figure Description

[0019] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0020] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] One or more embodiments are illustrated by way of example with reference numerals in the accompanying drawings. These illustrations do not constitute a limitation on the embodiments. Elements with the same reference numerals in the drawings are denoted as similar elements. Unless otherwise stated, the figures in the drawings are not to be limited by scale.

[0022] Figure 1 This is a cross-sectional view of a check valve for a range hood provided in an embodiment of this application.

[0023] Figure 2 This is a schematic diagram of the assembly of the first valve plate, the second valve plate, and the opening and holding mechanism provided in the embodiments of this application.

[0024] Figure 3 The present application provides a schematic diagram of the opening and holding mechanism.

[0025] Figure 4 for Figure 3 A magnified schematic diagram of the structure of A in the middle.

[0026] Explanation of reference numerals in the attached figures: 1. Valve body; 2. First valve plate; 21. Connecting piece; 22. Fourth shaft; 3. Second valve plate; 31. Clearance space; 4. First shaft; 5. Second shaft; 6. First connecting rod; 7. Second connecting rod; 8. Third shaft; 9. Bracket; 91. Opening; 100. Opening and holding mechanism; 110. Elastic component; 111. Guide rod; 1111. First section; 1112. Second section; 1113. Annular boss; 112. Swing rod; 113. Spring; 120. Constraint component; 121. Support; 122. Push rod; 123. Driving component; 124. Inclined surface structure. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0028] The following disclosure provides numerous different embodiments or examples for implementing various structures of this application. To simplify the disclosure, specific examples of components and arrangements are described below. These are merely examples and are not intended to limit the scope of this application. Furthermore, reference numerals and / or letters may be repeated in different examples. Such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed.

[0029] For ease of description, spatial relative terms may be used in the text to describe the relative position or movement of one element or feature relative to another element or feature, as shown in the figure. These relative terms include, for example, "inside," "outside," "middle," "outer," "below," "below," "above," "front," "back," etc. Such spatial relative terms are intended to include different orientations of the device in use or operation, other than those depicted in the figure. For example, if the device in the figure undergoes a positional flip, orientation change, or change of motion, these directional indications will change accordingly. For instance, an element described as "below other elements or features" or "below other elements or features" will subsequently be oriented "above other elements or features" or "above other elements or features." Therefore, the example term "below" can include both upper and lower orientations. The device may be otherwise oriented (rotated 90 degrees or in other directions), and the spatial relative descriptors used in the text will be interpreted accordingly.

[0030] like Figure 1 As shown in the embodiment of this application, a check valve for a range hood includes a valve body 1, a first valve plate 2, a second valve plate 3, and an opening and holding mechanism.

[0031] The valve body 1 is generally cylindrical and extends axially. One end of the valve body 1 connects to the air outlet of the range hood, and the other end connects to the air inlet of the common flue. The interior of the valve body 1 forms a channel for the passage of cooking fumes. The cross-sectional shape of the valve body 1 can be circular, elliptical, or rectangular, depending on the shape of the air outlet of the range hood. In this embodiment, the cross-section of the valve body 1 is circular.

[0032] A first shaft 4 is fixedly installed inside the valve body 1. The first shaft 4 is horizontally positioned and perpendicular to the central axis of the valve body 1, with its two ends fixed to two opposite side walls of the valve body 1. The first shaft 4 can be fixed to the valve body 1 by welding, riveting, or integral molding.

[0033] The first valve plate 2 and the second valve plate 3 are symmetrically hinged to the first shaft 4, and the first valve plate 2 and the second valve plate 3 can rotate around the first shaft 4. Specifically, the first valve plate 2 and the second valve plate 3 are respectively provided with hinge holes that mate with the first shaft 4, and the first shaft 4 passes through the hinge holes, so that the two valve plates can freely rotate around the first shaft 4 within the internal space of the valve body 1. The shapes of the first valve plate 2 and the second valve plate 3 match the cross-sectional shape of the valve body 1. In this embodiment, the first valve plate 2 and the second valve plate 3 are both semi-circular, and the two valve plates are joined together to form a complete circle, which is adapted to the circular cross-section of the valve body 1. The first valve plate 2 and the second valve plate 3 are made of metal or high-temperature resistant plastic, and have a certain rigidity and corrosion resistance.

[0034] When both valve plates are flipped to the closed position, the first valve plate 2 and the second valve plate 3 fit together, covering the cross-section of the valve body 1, thus blocking the passage for fumes to flow back into the room from the common flue. When the two valve plates are flipped to the open position, the passage of the valve body 1 is opened, and the fumes can be discharged smoothly. When the first valve plate 2 and the second valve plate 3 are in the closed position, their edges are either flush with the inner wall of the valve body 1 or have a small gap to ensure a sealing effect.

[0035] like Figure 2 and Figure 3 As shown, a second shaft 5, parallel to the first shaft 4, is provided above the first shaft 4. The second shaft 5 is slidably mounted on the valve body 1.

[0036] A first connecting rod 6 is hinged between the first valve plate 2 and the second shaft 5. Specifically, one end of the first connecting rod 6 is rotatably connected to the first valve plate 2 via a first hinge shaft, and the other end is sleeved on the second shaft 5 and can rotate around the second shaft 5. Similarly, a second connecting rod 7 is hinged between the second valve plate 3 and the second shaft 5. One end of the second connecting rod 7 is rotatably connected to the second valve plate 3 via a third hinge shaft, and the other end is also sleeved on the second shaft 5 and can rotate around the second shaft 5. The first connecting rod 6 and the second connecting rod 7 are of equal length and are symmetrically arranged with respect to the first shaft 4.

[0037] like Figure 3As shown, the second connecting rod 7, sleeved on the second shaft 5, forms a U-shaped structure at one end. This U-shaped structure is formed by the bifurcation of the end of the second connecting rod 7, having two opposing sidewalls and an opening. The first connecting rod 6, sleeved on the second shaft 5, is located within the opening of this U-shaped structure, i.e., sandwiched between the two sidewalls of the U-shaped structure of the second connecting rod 7. The second shaft 5 passes through both sidewalls of the U-shaped structure of the second connecting rod 7 and the end of the first connecting rod 6, so that the first connecting rod 6 and the second connecting rod 7 are coaxially rotatably mounted on the second shaft 5, and the first connecting rod 6 is axially limited by the U-shaped structure of the second connecting rod 7, preventing the first connecting rod 6 from moving axially along the second shaft 5.

[0038] Since both the first connecting rod 6 and the second connecting rod 7 are connected to the same second shaft 5, when the airflow pushes the first valve plate 2 and the second valve plate 3 to rotate around the first shaft 4, the first connecting rod 6 and the second connecting rod 7 simultaneously drive the second shaft 5 to slide upward, ensuring that the opening angle of the two valve plates remains consistent, thus achieving synchronous opening of the two valve plates. Compared to a structure where the two valve plates rotate independently, this avoids airflow turbulence, increased smoke exhaust resistance, and increased noise caused by the opening of a single valve plate, effectively maintaining smooth ventilation of the smoke hood, reducing pressure loss, and improving energy efficiency.

[0039] The opening and holding mechanism is connected to the first valve plate 2.

[0040] The first valve plate 2 and the second valve plate 3 rotate and open around the first shaft 4 under the action of airflow. When the range hood is turned on, the oil fume airflow enters from the air inlet of the valve body 1 and acts on the side surfaces of the first valve plate 2 and the second valve plate 3 facing the air inlet. Driven by the airflow pressure, the first valve plate 2 and the second valve plate 3 rotate upward around the first shaft 4, and the channel of the valve body 1 is opened. After the first valve plate 2 and the second valve plate 3 are rotated into position, the opening and holding mechanism applies a holding force to the first valve plate 2, keeping the first valve plate 2 and the second valve plate 3 in the open state. Since the first valve plate 2 is linked to the second valve plate 3 through the first connecting rod 6 and the second shaft 5, the second valve plate 3 is also kept open while the first valve plate 2 is kept open.

[0041] like Figure 3 As shown, the opening and holding mechanism 100 includes an elastic component 110 and a constraint component 120. One end of the elastic component 110 is connected to the first valve plate 2, and the other end is connected to the constraint component 120. After the first valve plate 2 and the second valve plate 3 are flipped into position, the constraint component 120 cooperates with the elastic component 110 to keep the first valve plate 2 and the second valve plate 3 in the open state. Specifically, in this application, the elastic component 110 is the part of the opening and holding mechanism 100 used for storing and releasing energy. The constraint component 120 is the part of the opening and holding mechanism 100 used for controlling the state switching of the elastic component.

[0042] The check valve of this application also includes a third shaft 8, which is arranged parallel to the first shaft 4, that is, the third shaft 8 extends in the horizontal direction and its axis is parallel to the axis of the first shaft 4. Since the second shaft 5 is also parallel to the first shaft 4, the third shaft 8 is also parallel to the second shaft 5.

[0043] like Figure 3 and Figure 4 As shown, the elastic component 110 includes a guide rod 111, a swing rod 112, and a spring 113.

[0044] The peripheral wall of the guide rod 111 extends radially outward to form an annular boss 1113, which divides the guide rod 111 into a first segment 1111 and a second segment 1112. The second segment 1112 of the guide rod 111 is rotatably connected to the first valve plate 2. Specifically, the second segment 1112 of the guide rod 111 is rotatably connected to the first valve plate 2 through a connector 21 and a fourth shaft 22. When the first valve plate 2 flips, it drives the guide rod 111 to move through the connector 21 and the fourth shaft 22.

[0045] One end of the rocker arm 112 is rotatably connected to the third shaft 8, that is, the third shaft 8 passes through the hinge hole at one end of the rocker arm 112, allowing the rocker arm 112 to rotate freely around the third shaft 8. The other end of the rocker arm 112 has a cavity with an opening. The first section 1111 of the guide rod 111 slidably extends into the cavity through this opening, that is, the first section 1111 of the guide rod 111 is inserted into the cavity of the rocker arm 112 and can slide within the cavity.

[0046] Spring 113 is sleeved on the first section 1111 of guide rod 111, with one end connected to the edge of the cavity opening of rocker arm 112 and the other end connected to the annular boss of guide rod 111. Spring 113 is a helical spring, with its inner diameter larger than the outer diameter of the first section 1111 of guide rod 111, allowing spring 113 to freely extend and retract on guide rod 111. When the relative position between guide rod 111 and rocker arm 112 changes, spring 113 is compressed or stretched. Spring 113 is made of spring steel, possessing a certain degree of elasticity and fatigue strength.

[0047] When the range hood is off, spring 113 is in a stretched state. At this time, guide rod 111 and swing rod 112 are tilted from the first valve plate 2 toward the third shaft 8.

[0048] When the first valve plate 2 and the second valve plate 3 flip, the guide rod 111 gradually extends into the cavity of the swing rod 112. The guide rod 111 and the swing rod 112 swing towards the second valve plate 3, and the spring 113 is compressed. The elongation force of the spring 113 causes the guide rod 111 to pull the first valve plate 2, maintaining the first valve plate 2 and the second valve plate 3 in the open state.

[0049] Specifically, the first valve plate 2 flips, causing the connecting piece 21 and the fourth shaft 22 to move, and the fourth shaft 22 causes the guide rod 111 to move. The first section of the guide rod 111 gradually slides into the cavity of the rocker arm 112, compressing the spring 113 and storing elastic potential energy. At the same time, since one end of the rocker arm 112 is connected to the support 121 through the third shaft 8, and the support 121 is initially limited by the push rod 122 and cannot move upward, the spring 113 is compressed between the annular boss 1113 of the guide rod 111 and the opening edge of the rocker arm 112.

[0050] When the first valve plate 2 and the second valve plate 3 are flipped into place, the guide rod 111 and the swing rod 112 tilt from the second valve plate 3 toward the third shaft 8, at which time the spring 113 is in a compressed state.

[0051] When spring 113 is compressed, it applies an elongation force to guide rod 111. Guide rod 111 transmits this force to first valve plate 2 through fourth shaft 22 and connector 21, keeping first valve plate 2 in the open state and preventing it from falling back due to gravity. Second valve plate 3 is linked to first valve plate 2 through first connecting rod 6 and second connecting rod 7, and is also kept in the open state.

[0052] Because spring 113 is continuously kept in a compressed state, the first valve plate 2 is subjected to a continuous elongation force, preventing vibration or trembling due to airflow fluctuations during the operation of the range hood, thus reducing noise caused by valve plate vibration. Simultaneously, the elongation force of spring 113 maintains the valve plate's opening angle, keeping the flow resistance of the airflow through the valve body 1 stable and preventing additional pressure loss due to changes in the valve plate angle, further improving the range hood's operating efficiency.

[0053] like Figure 3 As shown, in a preferred embodiment, the constraint assembly 120 includes a support 121, a push rod 122, and a drive member 123.

[0054] The support 121 is disposed within the valve body 1 and can slide vertically. In this embodiment, the support 121 is disposed within the opening 91 of the bracket 9, with its two ends slidably disposed in corresponding second slide rails, so that the support 121 can only slide vertically up and down and cannot move horizontally. The support 121 is generally block-shaped or plate-shaped, and has a certain strength and rigidity, used to support the third shaft 8 and cooperate with the push rod 122.

[0055] The third shaft 8 is fixedly mounted on the support 121. The third shaft 8 and the support 121 can be an interference fit, welded, or integrally formed.

[0056] The push rod 122 is horizontally positioned on one side of the support 121. The push rod 122 and the support 121 are engaged and abutted by the inclined structure 124. That is, the end of the push rod 122 facing the support 121 and the side of the support 121 facing the push rod 122 abut against each other through the inclined surface.

[0057] The output end of the drive element 123 is connected to the push rod 122. The drive element 123 is used to drive the push rod 122 to reciprocate horizontally. The drive element 123 is fixedly disposed inside the valve body 1, and its output end is connected to the push rod 122 via a connecting rod or directly. In one embodiment, the drive element 123 is a solenoid valve, and the push rod 122 is the push rod of the solenoid valve itself. When the solenoid valve is energized, it drives the push rod inside to extend or retract, thereby achieving horizontal movement. In other embodiments, the drive element 123 can also be a motor, cylinder, or other power source, as long as it can drive the push rod to move horizontally.

[0058] During the operation of the range hood, the drive component 123 does not move, the push rod 122 remains in place, and the support 121 is limited by the push rod 122 and cannot move.

[0059] After the range hood is turned off, the drive unit 123 drives the push rod 122 to move horizontally away from the support 121, releasing the restriction on the support 121. The compressed spring 113 releases energy, and the spring 113 drives the third shaft 8 to move upward. The spring 113 returns from the compressed state to the free state, the elongation force on the guide rod 111 disappears, and the first valve plate 2 and the second valve plate 3 begin to fall under the action of gravity.

[0060] After the first valve plate 2 and the second valve plate 3 fall to the set position, the drive unit 123 drives the push rod 122 to move horizontally in the direction toward the support 121, and pushes the support 121 downward to reset through the inclined structure. The support 121 drives the third shaft 8 and the rocker arm 112 back to the initial position, and the first valve plate 2 and the second valve plate 3 are completely closed.

[0061] like Figure 3 As shown, the inclined structure 124 includes a first inclined surface and a second inclined surface. The first inclined surface is located at one end of the push rod 122 facing the support 121, and the second inclined surface is located on the side of the support 121 facing the push rod 122. The first inclined surface and the second inclined surface have the same inclination direction and fit together.

[0062] Specifically, the push rod 122 has a first inclined surface at one end facing the support 121. The first inclined surface is inclined relative to the axial direction of the push rod 122, that is, there is a certain angle between the first inclined surface and the axis of the push rod 122. In this embodiment, the first inclined surface gradually slopes from one end to the other along the axial direction of the push rod 122, and its inclination angle is 30° to 60°, preferably 45°. The support 121 has a second inclined surface on the side facing the push rod 122. The second inclined surface is inclined relative to the sliding direction (vertical direction) of the support 121, and its inclination angle is the same as that of the first inclined surface, so that the first inclined surface and the second inclined surface can fit together.

[0063] When push rod 122 moves horizontally, the first inclined plane slides along the second inclined plane. Since the first and second inclined planes have the same inclination direction and are in contact with each other, when push rod 122 moves horizontally, support 121 moves vertically under the guidance of the inclined planes. Specifically, when push rod 122 moves horizontally away from support 121, support 121 is subjected to an upward component force and slides upward along the second slide rail; when push rod 122 moves horizontally towards support 121, support 121 is subjected to a downward component force and slides downward along the second slide rail.

[0064] Both the first and second inclined surfaces are smooth to reduce friction when they slide relative to each other. In this embodiment, the surfaces of the first and second inclined surfaces are polished or coated with a friction-reducing coating, such as a polytetrafluoroethylene coating.

[0065] like Figure 4 As shown, a connector 21 is fixedly mounted on the first valve plate 2. Specifically, the connector 21 is located between the connection point of the first connecting rod 6 and the first valve plate 2 and the first shaft 4, and does not interfere with the movement of the first connecting rod 6.

[0066] The connector 21 protrudes outward from the surface of the first valve plate 2. The connector 21 can be fixed to the first valve plate 2 by welding, riveting, bolting, or integral molding. In this embodiment, the connector 21 is integrally molded with the first valve plate 2, which has high structural strength.

[0067] The connector 21 is provided with a fourth shaft 22, which can be an interference fit, welded, or integrally formed with the connector 21. The fourth shaft 22 is arranged parallel to the first shaft 4.

[0068] One end of the guide rod 111 is rotatably connected to the fourth shaft 22. Specifically, this end of the guide rod 111 is provided with a hinge hole, and the fourth shaft 22 passes through the hinge hole, allowing the guide rod 111 to rotate freely around the fourth shaft 22. In this way, the guide rod 111 is rotatably connected to the first valve plate 2 through the fourth shaft 22 and the connecting piece 21.

[0069] When the first valve plate 2 flips, the connecting piece 21 moves with the first valve plate 2, and drives the guide rod 111 to move through the fourth shaft 22, thereby driving the entire elastic component to move.

[0070] It should be noted that the second valve plate 3 is provided with a clearance space 31 to avoid the connecting piece 21.

[0071] The clearance space 31 is specifically located at the edge of the second valve plate 3 and corresponds to the position of the connector 21. The clearance space 31 is generally in the shape of a groove or notch, and its shape and size are adapted to the movement trajectory of the connector 21.

[0072] When the first valve plate 2 and the second valve plate 3 flip, the connecting piece 21 moves in an arc along the direction of the first valve plate 2 toward the second valve plate 3. Without the clearance space 31, the connecting piece 21 would interfere with the second valve plate 3 during movement, hindering the normal flipping of the valve plates. The clearance space 31 allows the connecting piece 21 to extend into it during movement, thus avoiding collision or interference with the second valve plate 3 and ensuring smooth valve plate flipping.

[0073] The clearance space 31 can be formed by cutting off a portion of material from the edge of the second valve plate 3, or it can be formed directly during the manufacturing process of the second valve plate 3. In this embodiment, the clearance space 31 is a circular groove formed on the edge of the second valve plate 3.

[0074] The check valve of this application also includes a bracket 9. The bracket 9 is fixedly disposed inside the valve body 1 to provide sliding support for the second shaft 5 and the support 121. The bracket 9 can be fixed to the inner wall of the valve body 1 by welding, bolting, or snap-fitting.

[0075] The bracket 9 has an opening 91. The opening 91 extends upward from the bottom of the bracket 9 and is generally rectangular or U-shaped.

[0076] Two first slide rails (not shown in the attached drawings) are respectively provided on the two opposite side walls of the opening 91, and the two ends of the second shaft 5 are slidably disposed in the corresponding first slide rails. Specifically, the first slide rail is a groove or channel extending in the vertical direction, and its cross-sectional shape is adapted to the end shape of the second shaft 5. In this embodiment, the cross-section of the first slide rail is rectangular or arc-shaped, and the end of the second shaft 5 is provided with a sliding block that mates with the first slide rail. The sliding block is embedded in the first slide rail and can slide along the first slide rail. It can be understood that the second shaft 5 can slide freely in the vertical direction along the first slide rail, but cannot move horizontally, ensuring the linearity and stability of the movement of the second shaft 5. Ball bearings or sliding bushings can also be provided between the second shaft 5 and the first slide rail to reduce sliding friction.

[0077] The support 9 is also equipped with a second slide rail (not shown in the attached diagram), which is located below the first slide rail. The support 121 is slidably disposed in the second slide rail. Similar to the first slide rail, the second slide rail provides a vertical guide for the support 121, ensuring that the support 121 can only move up and down under the action of the inclined structure, and cannot move horizontally. Ball bearings or sliding bushings can also be provided between the support 121 and the second slide rail to reduce sliding friction.

[0078] Support 121 is located below the second shaft 5, and the two are vertically aligned without interfering with each other. The third shaft 8 is fixedly mounted on support 121, so when support 121 slides up and down along the second slide rail, the third shaft 8 also moves up and down accordingly.

[0079] In this embodiment, the first slide rail is located above and the second slide rail is located below, with a certain distance between them, to ensure that the second shaft 5 and the support 121 do not interfere with each other during the sliding process.

[0080] It should be understood that the elastic components of the aforementioned opening and holding mechanism are not limited to the combination of the aforementioned guide rod, slide rod, rocker arm and spring.

[0081] In other embodiments, the elastic component of the opening and holding mechanism can also be a magnetic component, which includes a permanent magnet fixedly mounted on the valve body or bracket, and a magnetic guide fixedly mounted on the first or second valve plate. After the first and second valve plates are flipped into position, the magnetic guide moves to a position opposite to the permanent magnet under the control of the constraint component and is attracted by the magnetic force of the permanent magnet, thereby keeping the first and second valve plates in the open state. When closed, the constraint component drives the magnetic guide to move out of the magnetic field of the permanent magnet, and the valve plate closes under the action of gravity.

[0082] The working principle of the check valve for range hoods in this application is as follows: In the initial state, i.e., when the range hood is off, the first valve plate 2 and the second valve plate 3 are in the closed position, together covering the cross-section of the valve body 1. At this time, the guide rod 111 and the swing rod 112 are inclined from the first valve plate 2 toward the third shaft 8, and the spring 113 is in a stretched state.

[0083] When the range hood is turned on, the oily fumes enter through the air inlet of the valve body 1 and act on the surfaces of the first valve plate 2 and the second valve plate 3 facing the air inlet. Driven by the airflow pressure, the first valve plate 2 and the second valve plate 3 rotate and open around the first shaft 4.

[0084] When the first valve plate 2 flips, it drives the second shaft 5 to slide upward along the first slide rail via the first connecting rod 6. Since the second shaft 5 is also connected to the second valve plate 3 via the second connecting rod 7, the second valve plate 3 also flips synchronously. The opening angles of the two valve plates remain consistent, achieving synchronous opening of both valve plates.

[0085] Simultaneously, the first valve plate 2 flips, causing the connecting piece 21 to move in an arc towards the second valve plate 3. The connecting piece 21 drives the guide rod 111 to move via the fourth shaft 22. The first section of the guide rod 111 gradually extends into the cavity of the swing rod 112, and the guide rod 111 and the swing rod 112 swing towards the second valve plate 3. At this time, the spring 113 is compressed between the annular boss 1113 of the guide rod 111 and the opening edge of the swing rod 112, storing elastic potential energy.

[0086] When the first valve plate 2 and the second valve plate 3 are flipped into place, the guide rod 111 and the swing rod 112 tilt from the second valve plate 3 toward the third shaft 8, at which time the spring 113 is in a compressed state.

[0087] During the operation of the range hood, the drive component 123 remains stationary, the push rod 122 remains in its original position, the support 121 is limited by the push rod 122 and cannot move, and the third shaft 8 and the swing rod 112 remain stationary. The spring 113 is continuously kept in a compressed state, and the elongation force of the spring 113 is transmitted to the first valve plate 2 through the guide rod 111 and the connecting piece 21, pulling the first valve plate 2 to keep it in the open state and preventing it from vibrating or falling back due to airflow fluctuations.

[0088] When the range hood is turned off, the oil fume flow disappears, and the first valve plate 2 and the second valve plate 3 are no longer pushed by the airflow pressure.

[0089] The drive unit 123 drives the push rod 122 to move horizontally away from the support 121, releasing the restriction on the support 121. The compressed spring 113 releases energy, causing the swing rod 112 and the third shaft 8 to move upward. The spring 113 returns from the compressed state to the free state, the elongation force on the guide rod 111 disappears, and the first valve plate 2 and the second valve plate 3 begin to fall under the action of gravity.

[0090] After the first valve plate 2 and the second valve plate 3 fall to the set position, the drive unit 123 drives the push rod 122 to move horizontally in the direction toward the support 121, and pushes the support 121 downward to reset through the inclined structure. The support 121 drives the third shaft 8 and the swing rod 112 back to the initial position, and the first valve plate 2 and the second valve plate 3 are completely closed, together covering the cross-section of the valve body 1, blocking the passage between the public flue and the room.

[0091] After closing, the guide rod 111 and the swing rod 112 return to their initial positions, and the spring 113 returns to its stretched state.

[0092] In the above embodiments, the descriptions of each embodiment have different focuses. For parts that are not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0093] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0094] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0095] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0096] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature being directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0097] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. The illustrative expressions of the above terms in this specification should not be construed as necessarily referring to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. In addition, those skilled in the art can combine and integrate the different embodiments or examples described in this specification.

[0098] Obviously, those skilled in the art can make various modifications and variations to this application without departing from the spirit and scope of this application. Since these modifications and variations fall within the scope of the claims and their equivalents, this application also intends to include these modifications and variations.

[0099] The above description describes specific embodiments of this application, but the scope of protection of this application is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in this application, and these modifications or substitutions should all be covered within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A check valve for a range hood, characterized in that, It includes a valve body, a first valve plate, a second valve plate, and an opening and holding mechanism; The valve body is fixedly provided with a first shaft, and the first valve plate and the second valve plate are symmetrically hinged on the first shaft. The first valve plate and the second valve plate rotate around the first shaft. A second shaft parallel to the first shaft is provided above the first shaft, and the second shaft is slidably mounted on the valve body. A first connecting rod is hinged between the first valve plate and the second shaft, and a second connecting rod is hinged between the second valve plate and the second shaft; The opening and holding mechanism is connected to the first valve plate; The first valve plate and the second valve plate are rotated and opened around the first axis under the action of airflow. When they are rotated into place, the opening and holding mechanism applies a holding force to the first valve plate, so that the first valve plate and the second valve plate remain in the open state.

2. The check valve for a range hood according to claim 1, characterized in that, The second connecting rod is sleeved on the second shaft to form a U-shaped structure at one end, and the first connecting rod is sleeved on the second shaft at one end located inside the opening of the U-shaped structure. The second shaft passes through both the U-shaped structure and the first connecting rod.

3. The check valve for a range hood according to claim 1, characterized in that, The opening and holding mechanism includes an elastic component and a constraint component; one end of the elastic component is connected to the first valve plate, and the other end is connected to the constraint component. After the first valve plate and the second valve plate are flipped into place, the constraint component cooperates with the elastic component to keep the first valve plate and the second valve plate in the open state.

4. The check valve for a range hood according to claim 3, characterized in that, It also includes a third shaft, which is arranged parallel to the first shaft; The elastic component includes a guide rod, a rocker arm, and a spring. The peripheral wall of the guide rod extends radially outward to form an annular boss, which divides the guide rod into a first segment and a second segment. The second segment of the guide rod is rotatably connected to the first valve plate. One end of the rocker arm is rotatably connected to the third shaft, and the other end is provided with a cavity. The cavity has an opening, and the first segment of the guide rod slidably extends into the cavity through the opening. The spring is sleeved on the first segment of the guide rod, with one end connected to the edge of the opening and the other end connected to the annular boss. When the first valve plate and the second valve plate flip, the guide rod gradually extends into the cavity of the swing rod, and the guide rod and the swing rod swing toward the second valve plate. The spring is compressed, and the elongation force of the spring causes the guide rod to pull the first valve plate, maintaining the first valve plate and the second valve plate in the open state.

5. The check valve for a range hood according to claim 4, characterized in that, The constraint assembly includes a support, a push rod, and a drive component. The third shaft is fixedly mounted on the support. The push rod and the support are engaged and abutted by an inclined surface structure. The output end of the drive component is connected to the push rod. After the range hood is turned off, the driving component drives the push rod to move horizontally away from the support, releasing the restriction on the support, and the spring drives the third shaft to move upward. The spring returns to its free state from the compressed state, and the first valve plate and the second valve plate fall under the action of gravity; after the first valve plate and the second valve plate fall to the set position, the driving member drives the push rod to move horizontally in the direction toward the support, pushing the support to reset.

6. The check valve for a range hood according to claim 5, characterized in that, The inclined structure includes a first inclined surface and a second inclined surface. The first inclined surface is disposed at the end of the push rod facing the support, and the second inclined surface is disposed at the end of the support facing the push rod. The first inclined surface and the second inclined surface have the same inclination direction and fit together.

7. The check valve for a range hood according to claim 4, characterized in that, A connector is fixedly mounted on the first valve plate, and a fourth shaft is provided on the connector. The fourth shaft is arranged parallel to the first shaft, and one end of the guide rod is rotatably connected to the fourth shaft.

8. The check valve for a range hood according to claim 7, characterized in that, The second valve plate is provided with a clearance space to avoid the connecting member.

9. The check valve for a range hood according to claim 1, characterized in that, It also includes a bracket, which has an opening that extends upward from the bottom of the bracket. Two side walls opposite to the opening are respectively provided with first slide rails, and the two ends of the second shaft are respectively slidably disposed in the corresponding first slide rails.

10. The check valve for a range hood according to claim 9, characterized in that, The support is also provided with a second slide rail, which is located below the first slide rail, and the support is slidably disposed in the second slide rail.

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