Adjustable-gear constant-current valve and detection device

Abstract

The application relates to the technical field of medical detection, and particularly relates to an adjustable-gear constant-current valve and a detection device. The adjustable-gear constant-current valve comprises a first valve body, an inner wall of the first valve body being provided with a first gear part and a second gear part; a second valve body, the first valve body and the second valve body being matched to form an airflow channel, and the first valve body being capable of moving relative to the second valve body; a valve flap, the valve flap being arranged in the airflow channel, the valve flap being provided with a free end and a fixed end, the free end being capable of rotating around the fixed end; as a pressure difference on both sides of the valve flap gradually increases, a rotating angle of the valve flap increases, and a distance between the free end and the first gear part or the second gear part gradually decreases; by moving the first valve body, the valve flap can be relatively arranged with the first gear part or the second gear part, so that the airflow channel is in a first gear state or a second gear state, and a first airflow flow rate passing through the airflow channel in the first gear state is different from a second airflow flow rate capable of passing through the airflow channel in the second gear state.

Description

Technical Field

[0001] This application relates to the field of medical testing technology, and in particular to an adjustable constant flow valve and testing equipment. Background Technology

[0002] Exhaled nitric oxide (FeNO) is produced by airway cells. The concentration of exhaled nitric oxide (FeNO) is related to the number of inflammatory cells and can reflect the state of respiratory inflammation. Therefore, exhaled nitric oxide (FeNO) testing can be used for the pre-diagnosis of respiratory inflammation and to identify respiratory diseases such as asthma. Exhaled nitric oxide (FeNO) testing requires a person to exhale a stable airflow of 50±5 ml / s and 200±20 ml / s at an expiratory pressure of at least 5 cmH2O (water) to detect lower respiratory tract and lung diseases, respectively. However, for children and patients with respiratory diseases, exhaling a constant airflow is difficult, requiring certain measures to assist the body in easily exhaling a constant airflow. Summary of the Invention

[0003] This application provides an adjustable constant flow valve and a testing device, which is designed to be simple in structure and easy to change the gear.

[0004] This application provides an adjustable-gear constant flow valve, comprising: a first valve body having an inner wall, the inner wall having a first gear position and a second gear position; a second valve body, the first valve body cooperating with the second valve body to form an airflow channel, and the first valve body being movable relative to the second valve body; and a valve disc disposed in the airflow channel, the valve disc having a free end and a fixed end, the free end being rotatable around the fixed end; wherein, the airflow channel has an inlet and an outlet, from the inlet to the outlet, as the pressure difference on both sides of the valve disc gradually increases, the rotation angle of the valve disc increases, and the distance between the free end and the first gear position or the second gear position gradually decreases; by moving the first valve body, the valve disc can be disposed opposite to the first gear position or the second gear position, so that the airflow channel is in a first gear position state or a second gear position state, the first airflow flow rate passing through the airflow channel in the first gear position state is different from the second airflow flow rate passing through the airflow channel in the second gear position state.

[0005] In this application, a valve disc is installed within an airflow channel. When a user exhales into the airflow channel, the air pressure acts on the channel, creating a pressure difference between the front and back sides of the valve disc. This pressure difference causes the valve disc to rotate within the airflow channel. By changing the user's exhalation pressure, the rotation angle of the valve disc within the airflow channel is altered, thus changing the area of ​​the airflow channel blocked by the valve disc along the airflow direction, and consequently, the airflow area within the airflow channel. Specifically, when the user's exhalation pressure increases, the pressure difference between the front and back sides of the valve disc increases, the rotation angle of the valve disc within the airflow channel increases, and the area occupied by the valve disc within the airflow channel increases, resulting in a decrease in the airflow area within the airflow channel. Conversely, when the user's exhalation pressure decreases, the pressure difference between the front and back sides of the valve disc decreases, the rotation angle of the valve disc within the airflow channel decreases, and the area occupied by the valve disc within the airflow channel decreases, resulting in a decrease in the airflow area within the airflow channel. By controlling the airflow rate from the airflow channel to the detection device through the relationship between the pressure difference between the front and back sides of the valve disc within the airflow channel and the airflow area, a constant airflow rate can be maintained within the airflow channel as much as possible, allowing the user to quickly exhale a specified flow rate and improving the reliability of exhaled breath detection.

[0006] Furthermore, the adjustable constant flow valve can also be equipped with a set-level section, with the valve disc positioned opposite this section. When the user exhales into the airflow channel, the airflow rate discharged from the airflow channel to the detection device remains constant at a given level. Alternatively, the adjustable constant flow valve can also be equipped with three or more sets of levels, i.e., a first set, a second set, a third set, a fourth set, etc., are provided on the first valve body. Moving the first valve body allows the valve disc to be positioned corresponding to one of the sets, placing the airflow channel 111 in the first, second, third, or Nth level state, etc., with different airflow rates passing through the airflow channel 111 in each level state. For example, the first level corresponds to an airflow rate of 50 ml / s ± 10%, and the second level corresponds to an airflow rate of 200 ml / s ± 10%. When the valve disc is positioned opposite the first gear position, the airflow channel is in the first gear position. After the user exhales into the airflow channel, the airflow rate discharged to the detection device remains at 50 ml / s ± 10%. When the first valve body is moved and the valve disc is positioned opposite the second gear position, the airflow channel is in the second gear position. After the user exhales into the airflow channel, the airflow rate discharged to the detection device remains at 200 ml / s ± 10%. In this embodiment, the adjustable constant flow valve can be set with multiple gears to control the flow rate at multiple gears. Furthermore, gear switching can be directly achieved within an adjustable constant flow valve, making operation simple and convenient.

[0007] In one possible design, the first gear position includes a first curved surface. From the air inlet to the air outlet, the distance between the first curved surface and the valve disc gradually increases, and during the rotation of the valve disc corresponding to the first curved surface, the first airflow rate in the airflow channel remains unchanged.

[0008] The second gear position includes a second curved surface. From the air inlet to the air outlet, the distance between the second curved surface and the valve disc gradually decreases, and the second airflow rate in the airflow channel remains unchanged during the rotation of the valve disc corresponding to the second curved surface.

[0009] The first curved surface is connected to the near end of the second curved surface, and the first curved surface is closer to the valve disc than the second curved surface.

[0010] In this application, the slope of the first curved surface gradually decreases from the air inlet to the air outlet. This change in the curvature of the first curved surface is designed to match the angular changes during valve rotation and the airflow area within the airflow channel, thereby ensuring a constant airflow within the airflow channel as much as possible. Conversely, the slope of the second curved surface gradually increases from the air inlet to the air outlet. This change in the curvature of the second curved surface is also designed to match the angular changes during valve rotation and the airflow area within the airflow channel, thereby ensuring a constant airflow within the airflow channel as much as possible.

[0011] In one possible design, the curvature variation patterns of the first surface and the second surface conform to Formula 1 and Formula 2;

[0012]

[0013] In the formula, Q is the flow rate, C is the throttling coefficient, and A is the flow area. P represents the pressure difference between the front and rear sides of the valve disc, ρ represents the fluid density, L represents the width of the airflow channel, d represents the distance between the valve disc and the sidewall of the airflow channel, H represents the height of the airflow channel, B represents the length of the valve disc, and θ represents the rotation angle of the valve disc. Here, θ is the angle at which the pressure difference pushes the valve disc to balance with the first elastic element. The simulation sets the stiffness of the first elastic element to fit the value of the airflow channel height H.

[0014] In one possible design, the adjustable constant flow valve includes a first elastic element, one end of which is connected to the valve disc, and the other end of which is connected to the second valve body.

[0015] When airflow passes through the airflow channel, the airflow can overcome the elastic force of the first elastic element and push the valve disc to rotate;

[0016] When there is no airflow in the airflow channel, the first elastic element drives the valve disc to reset through its rebound force.

[0017] In this application, during the process of the airflow driving the valve disc to rotate, the valve disc is able to overcome the reverse thrust exerted on it by the first elastic element and rotate, and the airflow force and the elastic force of the first elastic element are in balance; when the airflow disappears, the thrust of the valve disc on the first elastic element disappears, and the first elastic element pushes the valve disc back to its initial position through its own rebound force, resulting in a simple structure. When the valve disc and the first elastic element are in balance, the angle between the valve disc and the second valve body is no greater than 90°.

[0018] The first elastic element can be a torsion spring.

[0019] In one possible design, the adjustable constant flow valve further includes a seal that seals the connection between the first valve body and the second valve body.

[0020] In this application, a sealing element ensures the airtightness of the airflow channel, reducing the risk of partial airflow leakage along the gap at the connection between the first and second valve bodies. This sealing element can be a rubber ring, with the sealing ring fitted around the outer ring of the first or second valve body, or sealing oil can be applied at the connection between the first and second valve bodies.

[0021] In one possible design, the first valve body and the second valve body are connected along the height direction of the adjustable constant flow valve to form the airflow channel.

[0022] In this application, the first valve body and the second valve body have a U-shaped structure, and the two are spliced ​​together to form an airflow channel. After the first valve body and the second valve body are spliced ​​together, the first valve body can move relative to the second valve body. Moving the first valve body realizes gear switching. The first valve body and the second valve body adopt a spliced ​​connection method, which facilitates their assembly. The first valve body and the second valve body can also be connected by other connection methods, which are not limited in this embodiment.

[0023] In one possible design, the adjustable constant flow valve further includes a pusher, which, when pushed, can drive the first valve body to move.

[0024] In this application, the pusher and the first valve body can be fixedly connected. Pushing the pusher causes the first valve body to move relative to the second valve body, thereby changing the gear position. The pusher and the first valve body can be fixedly connected by a snap-fit ​​or threaded connection.

[0025] Alternatively, the pusher is equipped with a slider, and the first valve body is equipped with a slide rail that cooperates with the slider. The slider can slide along the slide rail. When the slider moves to abut against the side wall of the slide rail, the pusher drives the first valve body to move.

[0026] In one possible design, the adjustable constant flow valve includes a housing, in which the first valve body and the second valve body are mounted, and the first valve body is movable relative to the housing.

[0027] The adjustable constant flow valve further includes a first limiting member and a second limiting member, the first limiting member and the second limiting member are installed on the housing, and the first valve body is provided with a first mating part and a second mating part;

[0028] When the first limiting member engages with the first mating part, the airflow channel is in the first gear position; when the second limiting member engages with the second mating part, the airflow channel is in the second gear position.

[0029] In this application, the outer casing has an opening, at least a portion of the pusher extends out of the casing through the opening, and the pusher can slide along the opening to drive the first valve body to move. A first limiting member and a second limiting member are connected to the inner wall of the outer casing, and the pusher is located between the first limiting member and the second limiting member. A first mating part and a second mating part are disposed on the outer wall of the first valve body. When the first limiting member engages with the first mating part, the valve disc faces the first gear position, so that the airflow channel is in the first gear position. Moving the first valve body disengages the first limiting member from the first mating part, and the second limiting member engages with the second mating part, so that the valve disc faces the second gear position, so that the airflow channel is in the second gear position. The distance between the first limiting member and the second limiting member is less than the distance between the first mating part and the second mating part. The engagement of the first limiting member with the first mating part and the engagement of the second limiting member with the second mating part prompts the user to reach the shift position and restricts further movement of the first valve body, ensuring that the airflow channel remains in this gear position when the user exhales, thereby maintaining a constant airflow rate as much as possible. When shifting gears, only a slight increase in pushing force is needed to disengage the first limiting member from the first mating part or the second limiting member from the second mating part, thereby achieving the effect of displacement adjustment.

[0030] When the distance between the first mating part and the second mating part is long, and the stroke of the pusher needs to be greater than the displacement of the pipeline, the length of the slide can be increased so that the slider slides along the slide and there is an ineffective displacement. When the slider abuts against the side wall of the slide, the slider pushes the first valve body to move.

[0031] Specifically, the first and second limiting members can be bent elastic sheets, with the limiting portion of the elastic sheet having a conical structure, and the first and second mating portions being grooves. When the first valve body moves, the sidewall of the groove compresses the elastic sheet, causing it to disengage from the groove, and the elastic sheet remains compressed throughout the movement of the first valve body. When another groove moves below another elastic sheet, the elastic sheet partially engages itself within the groove due to its own elasticity.

[0032] Alternatively, the first and second limiting members can be spheres, with a housing cavity for holding the sphere. The sphere can roll within the cavity, and the opening of the cavity is smaller than the diameter of the sphere to prevent it from falling. The depth of the cavity is greater than the diameter of the sphere so that the sphere can retract into the cavity. When the first valve body is moved, the sphere retracts into the cavity. When the first limiting member (second limiting member) engages with the first mating part (second mating part), part of the sphere falls into the groove.

[0033] In one possible design, the second valve body is at least partially fitted onto the first valve body along the airflow direction to form the airflow channel.

[0034] In this application, a first valve body is nested within a second valve body. Gear switching is achieved by changing the depth to which the first valve body enters the second valve body. The first valve body can be a fixed part, with the second valve body moving to switch gears; alternatively, the second valve body can be a fixed part, with the first valve body moving to switch gears. This eliminates the need for other mating parts to push the first or second valve body, reducing manufacturing costs.

[0035] In one possible design, the adjustable constant flow valve further includes a third limiting member, which is connected to the second valve body, and the first valve body is provided with a third mating part and a fourth mating part.

[0036] When the third limiting member engages with the third mating part, the airflow channel is in the first gear position; when the third limiting member engages with the fourth mating part, the airflow channel is in the second gear position.

[0037] In this application, the third and fourth mating parts are disposed on the outer wall of the first valve body. When the third limiting member engages with the third mating part, the valve disc faces the first gear position, so that the airflow passage is in the first gear position. Moving the first valve body disengages the third limiting member from the third mating part, and moves the third limiting member with the first valve body to the fourth mating part, so that the third limiting member engages with the fourth mating part, and the valve disc faces the second gear position, so that the airflow passage is in the second gear position. The engagement of the third limiting member with the third mating part and the engagement of the third limiting member with the fourth mating part prompts the user to reach the shift position and restricts further movement of the first valve body, ensuring that the airflow passage remains in that gear position during exhalation, thereby maintaining a constant airflow rate as much as possible. During shifting, only a slight increase in pushing force is needed to disengage the third limiting member from the third or fourth mating part.

[0038] In one possible design, the second valve body is provided with a receiving groove, and the third limiting member is disposed within the receiving groove;

[0039] During the movement of the first valve body, the third limiting member retracts into the receiving groove;

[0040] When the airflow channel is in the first gear position or the second gear position, at least a portion of the third limiting member is engaged with the third mating part or the fourth mating part.

[0041] In this application, when the first valve body needs to be moved to change gears (e.g., from the first gear to the second gear), the side wall of the third mating part pushes the third limiting member out and retracts into the receiving groove. During the movement of the first valve body, the third limiting member remains retracted into the receiving groove while abutting against the outer wall of the first valve body. When the fourth mating part moves below the third limiting member, the third limiting member falls and engages with the fourth mating part. By providing this receiving groove, when the third limiting member is not engaged with the third or fourth mating part, there is no need to provide movement space for the third limiting member, thus reducing the overall volume of the adjustable constant flow valve and facilitating its storage.

[0042] The third limiting member may include a limiting block and a spring. One end of the spring is connected to the bottom wall of the receiving groove, and the other end of the spring is connected to the limiting block. The third and fourth mating parts are grooves. When the first valve body is moved, the side wall of the groove pushes the limiting block out of the groove, while the limiting block compresses the spring. When another groove moves below the limiting block, the limiting block does not compress the spring, and the spring pushes the limiting block into the groove through its rebound force. Alternatively, the third limiting member may be a ball that can roll within the receiving groove. The opening of the receiving groove is smaller than the diameter of the ball to limit the ball from falling, and the depth of the receiving groove is greater than the diameter of the ball so that the ball can retract into the receiving groove. When the first valve body is moved, the ball can retract into the receiving groove. When the third limiting part engages with the third mating part (fourth mating part), part of the ball falls into the groove.

[0043] This application also provides a detection device for detecting nitric oxide content, the detection device comprising:

[0044] An adjustable constant flow valve, wherein the constant flow valve is the adjustable constant flow valve described above.

[0045] A detection device is used to detect the gas passing through the constant flow valve. Attached Figure Description

[0046] Figure 1 A schematic diagram of the adjustable constant flow valve provided in this application in a specific embodiment;

[0047] Figure 2 for Figure 1 Schematic diagram of the middle section;

[0048] Figure 3 forFigure 1 A cross-sectional view of the adjustable constant flow valve in the first position.

[0049] Figure 4 for Figure 1 A cross-sectional view of the adjustable constant flow valve in the second position.

[0050] Figure 5 A cross-sectional schematic diagram of the adjustable constant flow valve provided in this application in the first position state in another specific embodiment;

[0051] Figure 6 for Figure 5 A cross-sectional view of a constant flow valve with adjustable settings in the second setting.

[0052] Figure 7 A simplified cross-sectional schematic diagram of the adjustable constant flow valve provided in this application;

[0053] Figure 8 This is a schematic diagram of the testing equipment provided in this application.

[0054] Figure label:

[0055] 1-Adjustable constant flow valve, 11-First valve body, 111-Airflow channel, 111a-Air inlet, 111b-Air outlet, 112-First gear position, 113-Second gear position, 114-First mating part, 115-Second mating part, 116-Third mating part, 117-Fourth mating part, 12-Second valve body, 121-Receiving groove, 13-Valve disc, 131-Free end, 132-Fixed end, 14-First elastic element, 15-Pushing element, 16-Outer shell, 17-First limiting element, 18-Second limiting element, 19-Third limiting element;

[0056] 2-Detection equipment, 21-Detection device;

[0057] L - width of airflow channel, d - distance between valve disc and side wall of airflow channel, H - height of airflow channel, B - height of valve disc, θ - rotation angle of valve disc.

[0058] 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. Detailed Implementation

[0059] To better understand the technical solution of this application, the embodiments of this application will be described in detail below with reference to the accompanying drawings.

[0060] In one specific embodiment, the present application will be further described in detail below with reference to specific embodiments and accompanying drawings.

[0061] Exhaled nitric oxide (FeNO), produced by airway cells, is a biomarker of airway inflammation and is widely used in the diagnosis and treatment of respiratory diseases, such as asthma. The exhaled nitric oxide (FeNO) test requires a person to exhale a steady flow of air at an expiratory pressure of at least 5 cmH2O (water) at a rate of 50±5 ml / s and 200±20 ml / s, respectively, to detect lower respiratory tract and lung diseases. However, for children and patients with respiratory diseases, exhaling a constant flow of air is difficult, requiring certain measures to assist the body in easily exhaling a constant flow of air.

[0062] Existing methods for maintaining a constant exhaled airflow rely on the user adjusting their expiratory airflow based on visual and auditory feedback from the device. However, some users with poor responsiveness may experience a lag, and when adjusting based on feedback, insufficient expiratory control can cause the expiratory flow to exceed or fall below the desired range for short periods. While this method effectively prompts the user to control their expiratory flow, it requires significant user involvement, has low reliability, and results in unstable expiratory flow.

[0063] Some devices employ electrically controlled airflow regulators, which use sensors to acquire the flow rate within the tubing. After processing this data, the motor controls the valve opening to stabilize the user's expiratory flow within a certain range. However, when the user begins exhaling with a high pressure, the motor shuts off to its minimum, causing excessive air resistance and making sustained exhalation difficult. Furthermore, for airflow detection devices, implementing a complete electrically driven control system to achieve constant flow significantly increases costs.

[0064] Some constant flow valves employ self-regulating adjustable settings, controlling expiratory flow rate mechanically. By utilizing the pressure difference between the inlet and outlet of the adjustable constant flow valve, the flow area in the pipeline is altered through valve disc deformation / displacement, thereby controlling the airflow. However, existing adjustable constant flow valves rely on internal pressure differentials to generate deformation / displacement, often requiring multiple structural components installed inside the pipeline, resulting in a complex operating principle and structure. Furthermore, existing adjustable constant flow valves can only control one flow rate setting; two adjustable constant flow valves might be needed to meet the requirements of 50 ml / s and 200 ml / s for exhaled nitric oxide (FeNO) detection, increasing costs and hindering the portability of exhaled nitric oxide (FeNO) detection devices.

[0065] To solve the above-mentioned technical problems, this embodiment provides a detection device, which is a nitric oxide content detection device, including an adjustable constant flow valve 1 and a detection device. The adjustable constant flow valve 1 is connected to the detection device so that the gas flowing out of the adjustable constant flow valve 1 can enter the detection device for detection.

[0066] like Figure 1 and Figure 2 As shown, the adjustable constant flow valve 1 includes a first valve body 11, a second valve body 12, and a valve disc 13. The first valve body 11 has an inner wall with a first position portion 112 and a second position portion 113. The first valve body 11 and the second valve body 12 cooperate to form an airflow channel 111, and the first valve body 11 can move relative to the second valve body 12. The valve disc 13 is disposed in the airflow channel 111 and has a free end 131 and a fixed end 132. The free end 131 can rotate around the fixed end 132. The airflow channel 111 has an inlet 111a and an outlet 111b. From the inlet 111a to the outlet 111b, as the pressure difference on both sides of the valve disc 13 gradually increases, the rotation angle of the valve disc 13 increases, and the distance between the free end 131 and the first position portion 112 or the second position portion 113 gradually decreases. By moving the first valve body 11, the valve disc 13 can be positioned opposite to the first gear part 112 or the second gear part 113, so that the airflow channel 111 is in the first gear state or the second gear state. The first airflow rate passing through the airflow channel 111 in the first gear state is different from the second airflow rate passing through the airflow channel 111 in the second gear state.

[0067] In this embodiment, the valve disc 13 is installed within the airflow channel 111. When the user exhales into the airflow channel 111, the air pressure acts on the airflow channel 111, creating a pressure difference between the front and rear sides of the valve disc 13. This pressure difference causes the valve disc 13 to rotate within the airflow channel 111. By changing the user's exhalation pressure, the rotation angle of the valve disc 13 within the airflow channel 111 is altered, thus changing the area of ​​the airflow channel 111 blocked by the valve disc 13 along the airflow direction, and consequently, changing the airflow area within the airflow channel 111. That is, when the user's exhalation pressure increases, the pressure difference between the front and rear sides of the valve disc 13 increases, the rotation angle of the valve disc 13 within the airflow channel 111 increases, and the area occupied by the valve disc 13 within the airflow channel 111 increases, resulting in a decrease in the airflow area within the airflow channel 111. Conversely, when the user's exhalation pressure decreases, the pressure difference between the front and rear sides of the valve disc 13 decreases, the rotation angle of the valve disc 13 within the airflow channel 111 decreases, and the area occupied by the valve disc 13 within the airflow channel 111 decreases, resulting in a decrease in the airflow area within the airflow channel 111. The airflow rate from the airflow channel 111 to the detection device is controlled by the relationship between the air pressure difference on the front and rear sides of the valve disc 13 inside the airflow channel 111 and the airflow flow area, so as to maintain a constant airflow rate from the airflow channel 111 as much as possible, so that the user can quickly and stably blow out the braking flow rate and improve the reliability of exhaled breath detection.

[0068] Furthermore, the adjustable constant flow valve 1 can also be provided with a speed setting section, with the valve disc 13 positioned opposite to this speed setting section. After the user exhales into the airflow channel 111, the airflow rate discharged from the airflow channel 111 to the detection device remains at a constant speed setting. Alternatively, the adjustable constant flow valve 1 can also be provided with at least three or more speed setting sections, i.e., a first speed setting section 112, a second speed setting section 113, a third speed setting section, a fourth speed setting section, etc., are provided on the first valve body 11. Moving the first valve body 11 allows the valve disc 13 to be positioned corresponding to one of the speed setting sections, so that the airflow channel 111 is in the first speed setting state, the second speed setting state, the third speed setting state, or the Nth speed setting state, etc., and the airflow rate passing through the airflow channel 111 is different in each speed setting state. For example, the airflow rate corresponding to the first speed setting section 112 is 50ml / s±10%, and the airflow rate corresponding to the second speed setting section 113 is 200ml / s±10%. When the valve disc 13 is positioned opposite the first gear position 112, the airflow channel 111 is in the first gear position. After the user exhales into the airflow channel 111, the airflow rate discharged from the airflow channel 111 to the detection device remains at 50 ml / s ± 10%. When the first valve body 11 is moved and the valve disc 13 is positioned opposite the second gear position 113, the airflow channel 111 is in the second gear position. After the user exhales into the airflow channel 111, the airflow rate discharged from the airflow channel 111 to the detection device remains at 200 ml / s ± 10%. In this embodiment, the adjustable constant flow valve 1 can be set with multiple gears to control the flow rate of multiple gears. Furthermore, gear switching can be directly achieved within an adjustable constant flow valve 1, making operation simple and convenient.

[0069] Furthermore, such as Figure 3 As shown, the adjustable-gear constant flow valve 1 includes a first elastic element 14. One end of the first elastic element 14 is connected to the valve disc 13, and the other end is connected to the second valve body 12. When airflow flows through the airflow channel 111, the airflow can overcome the elastic force of the first elastic element 14 and push the valve disc 13 to rotate. When there is no airflow in the airflow channel 111, the first elastic element 14 drives the valve disc 13 to reset through its rebound force. During the process of the airflow pushing the valve disc 13 to rotate, the valve disc 13 can overcome the reverse thrust applied to it by the first elastic element 14 and rotate, and the airflow force is balanced with the elastic force of the first elastic element 14. When the airflow disappears, the thrust of the valve disc 13 on the first elastic element 14 disappears, and the first elastic element 14 pushes the valve disc 13 back to the initial position through its own rebound force. The structure is simple, reducing the manufacturing cost of the adjustable-gear constant flow valve 1. When the valve disc 13 and the first elastic element 14 are balanced, the angle between the valve disc 13 and the second valve body 12 is no greater than 90°.

[0070] The first elastic element 14 can be a torsion spring.

[0071] The adjustable constant flow valve 1 also includes a seal. The seal seals the connection between the first valve body 11 and the second valve body 12, ensuring the airtightness of the airflow channel 111 and reducing the risk of partial airflow leakage along the gap in the connection between the first valve body 11 and the second valve body 12. This seal can be a rubber ring, with a sealing ring fitted around the outer ring of the first valve body 11 or the second valve body 12, or it can be made of sealing oil at the connection between the first valve body 11 and the second valve body 12. This embodiment does not limit the sealing method.

[0072] like Figures 1 to 4 As shown, in one possible design, along the height direction of the adjustable constant flow valve 1, the first valve body 11 and the second valve body 12 are connected to form an airflow channel 111. In this embodiment, the first valve body 11 and the second valve body 12 have a U-shaped structure, and the two are spliced ​​together to form the airflow channel 111. After the first valve body 11 and the second valve body 12 are spliced ​​together, the first valve body 11 can move relative to the second valve body 12. Moving the first valve body 11 achieves gear switching. The first valve body 11 and the second valve body 12 adopt a spliced ​​connection method, which facilitates their assembly. The first valve body 11 and the second valve body 12 can also be connected in other ways, which are not limited in this embodiment.

[0073] Furthermore, such as Figures 1 to 4 As shown, the adjustable constant flow valve 1 also includes a pusher 15. When the pusher 15 is pushed, it can drive the first valve body 11 to move. In this embodiment, the pusher 15 and the first valve body 11 can be fixedly connected. Pushing the pusher 15 causes the first valve body 11 to move relative to the second valve body 12, thereby realizing the gear change. The pusher 15 and the first valve body 11 can be fixedly connected by a snap or a thread.

[0074] Alternatively, the pusher 15 may be equipped with a slider, and the first valve body 11 may be equipped with a slide rail that cooperates with the slider. The slider can slide along the slide rail. When the slider moves to abut against the side wall of the slide rail, the pusher 15 drives the first valve body 11 to move.

[0075] like Figure 3 and Figure 4As shown, the adjustable constant flow valve 1 includes a housing 16, a first valve body 11 and a second valve body 12 are installed inside the housing 16, and the first valve body 11 is movable relative to the housing 16; the adjustable constant flow valve 1 also includes a first limiting member 17 and a second limiting member 18, the first limiting member 17 and the second limiting member 18 are installed in the housing 16, and the first valve body 11 is provided with a first mating part 114 and a second mating part 115; when the first limiting member 17 is engaged with the first mating part 114, the airflow channel 111 is in the first position state, and when the second limiting member 18 is engaged with the second mating part 115, the airflow channel 111 is in the second position state.

[0076] In this embodiment, the outer casing 16 has an opening, at least a portion of the pusher 15 extends out of the outer casing 16 along the opening, and the pusher 15 can slide along the opening to drive the first valve body 11 to move. A first limiting member 17 and a second limiting member 18 are connected to the inner wall of the outer casing 16, and the pusher 15 is located between the first limiting member 17 and the second limiting member 18. A first mating part 114 and a second mating part 115 are disposed on the outer wall of the first valve body 11. When the first limiting member 17 engages with the first mating part 114, the valve disc 13 faces the first gear position 112, so that the airflow channel 111 is in the first gear position. Moving the first valve body 11 causes the first limiting member 17 to disengage from the first mating part 114, and the second limiting member 18 engages with the second mating part 115, causing the valve disc 13 to face the second gear position 113, so that the airflow channel 111 is in the second gear position. The distance between the first limiting member 17 and the second limiting member 18 is less than the distance between the first mating part 114 and the second mating part 115. The engagement of the first limiting member 17 with the first mating part 114 and the second limiting member 18 with the second mating part 115 signals to the user that they have reached the shift position and restricts the continued movement of the first valve body 11, ensuring that the airflow channel 111 remains in that position during exhalation, thus maintaining a constant airflow rate through the airflow channel 111 as much as possible. During shifting, only a slight increase in pushing force is needed to disengage the first limiting member 17 from the first mating part 114 or the second limiting member 18 from the second mating part 115, achieving the effect of displacement adjustment.

[0077] When the distance between the first mating part 114 and the second mating part 115 is long, and the stroke of the pusher 15 needs to be greater than the displacement of the pipeline, the length of the slide can be increased so that the slider slides along the slide and there is an ineffective displacement. When the slider abuts against the side wall of the slide, the slider pushes the first valve body 11 to move.

[0078] Specifically, such as Figure 3 and Figure 4As shown, the first limiting member 17 and the second limiting member 18 can be bent elastic sheets, with the limiting portion of the elastic sheet having a conical structure, and the first mating portion 114 and the second mating portion 115 being grooves. When the first valve body 11 moves, the sidewall of the groove squeezes the elastic sheet, causing it to disengage from the groove, and the elastic sheet remains compressed throughout the movement of the first valve body 11. When another groove moves below another elastic sheet, the elastic sheet partially engages itself within the groove due to its own elasticity.

[0079] Alternatively, the first limiting member 17 and the second limiting member 18 can be spheres, and the outer shell 16 has a receiving cavity for placing the sphere. The sphere can roll within the receiving cavity. The opening of the receiving cavity is smaller than the diameter of the sphere to limit the sphere from falling. The depth of the receiving cavity is greater than the diameter of the sphere so that the sphere can retract into the receiving cavity. When the first valve body 11 is moved, the sphere can retract into the receiving cavity. When the first limiting member 17 (second limiting member 18) engages with the first mating part 114 (second mating part 115), part of the sphere falls into the groove.

[0080] like Figure 5 and Figure 6 As shown, in another possible design, at least a portion of the second valve body 12 is fitted onto the first valve body 11 along the airflow direction, forming an airflow channel 111. In this embodiment, the first valve body 11 is nested within the second valve body 12, and gear switching is achieved by changing the depth of the first valve body 11 entering the second valve body 12. The first valve body 11 can be a fixed part, with the second valve body 12 moving to switch gears; alternatively, the second valve body 12 can be a fixed part, with the first valve body 11 moving to switch gears. This eliminates the need for other mating parts to push the first valve body 11 or the second valve body 12, reducing manufacturing costs.

[0081] like Figure 5 and Figure 6 As shown, the adjustable constant flow valve 1 further includes a third limiting member 19, which is connected to the second valve body 12. The first valve body 11 is provided with a third mating part 116 and a fourth mating part 117. When the third limiting member 19 is mated with the third mating part 116, the airflow channel 111 is in the first position. When the third limiting member 19 is mated with the fourth mating part 117, the airflow channel 111 is in the second position.

[0082] In this embodiment, the third mating part 116 and the fourth mating part 117 are disposed on the outer wall of the first valve body 11. When the third limiting member 19 engages with the third mating part 116, the valve disc 13 is opposite to the first gear part 112, so that the airflow channel 111 is in the first gear state. When the first valve body 11 is moved, the third limiting member 19 disengages from the third mating part 116 and moves with the first valve body 11 to the fourth mating part 117, so that the third limiting member 19 engages with the fourth mating part 117, and the valve disc 13 is opposite to the second gear part 113, so that the airflow channel 111 is in the second gear state. The engagement of the third limiting member 19 with the third mating part 116 and the engagement of the third limiting member 19 with the fourth mating part 117 prompts the user to reach the shift position and restricts the first valve body 11 from continuing to move, ensuring that the airflow channel 111 is always in this gear state when the user exhales, so as to maintain a constant airflow rate from the airflow channel 111 as much as possible. When shifting gears, only a slight increase in pushing force is needed to disengage the third limiting member 19 from the third mating part 116 or the fourth mating part 117.

[0083] Specifically, such as Figure 5 and Figure 6 As shown, the second valve body 12 is provided with a receiving groove 121, and the third limiting member 19 is disposed in the receiving groove 121. During the movement of the first valve body 11, the third limiting member 19 retracts into the receiving groove 121. When the airflow channel 111 is in the first gear state or the second gear state, at least a portion of the third limiting member 19 is engaged with the third mating part 116 or the fourth mating part 117. In this embodiment, when the first valve body 11 needs to be moved to change gears (such as changing from the first gear state to the second gear state), the side wall of the third mating part 116 pushes the third limiting member 19 out and retracts into the receiving groove 121. During the movement of the first valve body 11, the third limiting member 19 is always retracted into the receiving groove 121 and abuts against the outer wall of the first valve body 11. When the fourth mating part 117 moves to the lower part of the third limiting member 19, the third limiting member 19 falls and engages with the fourth mating part 117. By setting the receiving groove 121, when the third limiting member 19 is not locked in the third mating part 116 or the fourth mating part 117, the receiving groove 121 is set in the receiving groove, thereby eliminating the need to provide movement space for the third limiting member 19, reducing the overall volume of the adjustable constant flow valve 1, and making it easier to store.

[0084] The third limiting member 19 may include a limiting block and a spring. One end of the spring is connected to the bottom wall of the receiving groove 121, and the other end of the spring is connected to the limiting block. The third mating part 116 and the fourth mating part 117 are grooves. When the first valve body 11 is moved, the side wall of the groove pushes the limiting block out of the groove, and at the same time, the limiting block compresses the spring. When another groove moves to below the limiting block, the limiting block does not compress the spring, and the spring pushes the limiting block into the groove through its rebound force.

[0085] Alternatively, the third limiting member 19 can be a sphere that can roll within the receiving groove 121. The opening of the receiving groove 121 is smaller than the diameter of the sphere to limit its fall, and the depth of the receiving groove 121 is greater than the diameter of the sphere so that the sphere can retract into the receiving groove 121. When the first valve body 11 is moved, the sphere can retract into the receiving groove 121. When the third limiting part engages with the third mating part 116 (fourth mating part 117), part of the sphere falls into the groove.

[0086] In one possible design, the first gear position 112 includes a first curved surface. From the air inlet 111a to the air outlet 111b, the distance between the first curved surface and the valve disc 13 gradually increases, and the first airflow rate within the airflow channel 111 remains constant during the rotation of the valve disc 13 corresponding to the first curved surface. The second gear position 113 includes a second curved surface. From the air inlet 111a to the air outlet 111b, the distance between the second curved surface and the valve disc 13 gradually decreases, and the second airflow rate within the airflow channel 111 remains constant during the rotation of the valve disc 13 corresponding to the second curved surface. The first curved surface and the second curved surface are connected at their proximal ends, with the first curved surface closer to the valve disc 111 relative to the second curved surface.

[0087] In this embodiment, the slope of the first curved surface gradually decreases from the air inlet 111a to the air outlet 111b. This change in the curvature of the first curved surface is designed to match the angular changes during the rotation of the valve disc 13 and the airflow area within the airflow channel 111, thereby ensuring a constant airflow within the airflow channel 111. Conversely, the slope of the second curved surface gradually increases from the air inlet 111a to the air outlet 111b. This change in the curvature of the second curved surface is designed to match the angular changes during the rotation of the valve disc 13 and the airflow area within the airflow channel 111, thereby ensuring a constant airflow within the airflow channel 111.

[0088] Furthermore, such as Figure 2 and Figure 7 As shown,

[0089] According to the formula (Where Q is the flow rate, C is the throttling coefficient, and A is the flow area)

[0090] P represents the pressure difference across valve disc 13, and ρ represents the fluid density. Therefore, at inlet 111a, as the airflow velocity increases, the pressure difference across valve disc 13... As pressure P increases / decreases, the rotation angle of valve disc 13 increases / decreases, and the distance between the free end 131 and the first gear position 112 decreases / increases, causing the flow area A within the airflow channel 111 to decrease / increase, thereby maintaining the airflow rate Q when the airflow channel 111 is in the first gear position. As the airflow velocity decreases, the pressure difference across valve disc 13... As P increases / decreases, the rotation angle of valve disc 13 increases / decreases, and the distance between the free end 131 and the second gear section 113 decreases / increases, resulting in a decrease / increase in the flow area A within the airflow channel 111, thereby maintaining the airflow rate Q when the airflow channel 111 is in the second gear state. Furthermore, the curvature changes of the first curved surface of the first gear section 112 and the second curved surface of the second gear section 113 conform to Formula 1 and Formula 2:

[0091]

[0092] In the formula, Q is the flow rate, C is the throttling coefficient, and A is the flow area. P is the pressure difference between the front and rear sides of valve disc 13, ρ is the fluid density, L is the width of airflow channel 111, d is the distance between valve disc 13 and the sidewall of airflow channel 111, H is the height of airflow channel 111, B is the length of valve disc 13, and θ is the rotation angle of valve disc 13. P is related. Where θ is the angle when the pressure difference pushes the valve disc 13 and the first elastic element 14 to balance. The stiffness of the first elastic element 14 is set in the simulation to fit the height H value of the airflow channel 111.

[0093] In one possible design, the adjustable constant flow valve can also be used to control the flow of gas or water in pipelines, such as in natural gas lines or water pipes, enabling it to deliver a constant flow of fluid at different pressures.

[0094] like Figure 8 As shown, this embodiment also provides a detection device 2 for detecting nitric oxide content. The detection device 2 includes: an adjustable constant flow valve 1, which is the adjustable constant flow valve 1 in the above embodiments; and a detection device 21, which is used to detect the gas (such as nitric oxide gas) passing through the adjustable constant flow valve 1, thereby diagnosing diseases.

[0095] The foregoing preferred embodiments have further illustrated the objectives, technical solutions, and advantages of the present invention. It should be understood that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A constant flow valve with adjustable range, characterized in that, The adjustable constant flow valve includes: A first valve body; the first valve body has an inner wall, and the inner wall is provided with a first gear position and a second gear position; The second valve body is used in conjunction with the first valve body to form an airflow channel, and the first valve body is movable relative to the second valve body. A valve disc is disposed in the airflow channel. The valve disc has a free end and a fixed end. The free end can rotate around the fixed end. The airflow channel has an air inlet and an air outlet. From the air inlet to the air outlet, as the pressure difference on both sides of the valve disc gradually increases, the rotation angle of the valve disc increases, and the distance between the free end and the first gear position or the second gear position gradually decreases. Wherein, by moving the first valve body, the valve disc can be arranged opposite to the first gear part or the second gear part, so that the airflow channel is in the first gear state or the second gear state. The first airflow flow rate passing through the airflow channel in the first gear state is different from the second airflow flow rate passing through the airflow channel in the second gear state.

2. The adjustable constant flow valve according to claim 1, characterized in that, The first gear position includes a first curved surface. From the air inlet to the air outlet, the distance between the first curved surface and the valve disc gradually increases, and during the rotation of the valve disc corresponding to the first curved surface, the first airflow rate in the airflow channel remains unchanged. The second gear position includes a second curved surface. From the air inlet to the air outlet, the distance between the second curved surface and the valve disc gradually decreases, and the second airflow rate in the airflow channel remains unchanged during the rotation of the valve disc corresponding to the second curved surface. The first curved surface is connected to the near end of the second curved surface, and the first curved surface is closer to the valve disc than the second curved surface.

3. The adjustable constant flow valve according to claim 2, characterized in that, The curvature changes of the first and second surfaces conform to Formula 1 and Formula 2: ； In the formula, Q is the flow rate, C is the throttling coefficient, and A is the flow area. P is the pressure difference between the front and rear sides of the valve disc, ρ is the fluid density, L is the width of the airflow channel, d is the distance between the valve disc and the side wall of the airflow channel, H is the height of the airflow channel, B is the length of the valve disc, and θ is the rotation angle of the valve disc.

4. The adjustable constant flow valve according to any one of claims 1 to 3, characterized in that, The first valve body also includes one or more speed control sections.

5. The adjustable constant flow valve according to any one of claims 1 to 3, characterized in that, The adjustable constant flow valve includes a first elastic element, one end of which is connected to the valve disc, and the other end of which is connected to the second valve body. When airflow passes through the airflow channel, the airflow can overcome the elastic force of the first elastic element and push the valve disc to rotate; When there is no airflow in the airflow channel, the first elastic element drives the valve disc to reset through its rebound force.

6. The adjustable constant flow valve according to any one of claims 1 to 3, characterized in that, The adjustable constant flow valve also includes a sealing element that seals the connection between the first valve body and the second valve body.

7. The adjustable constant flow valve according to any one of claims 1 to 3, characterized in that, Along the height direction of the adjustable constant flow valve, the first valve body and the second valve body are connected to form the airflow channel.

8. The adjustable constant flow valve according to claim 7, characterized in that, The adjustable constant flow valve also includes a pusher, which, when pushed, can drive the first valve body to move.

9. The adjustable constant flow valve according to claim 7, characterized in that, The adjustable constant flow valve includes a housing, and the first valve body and the second valve body are installed inside the housing. The first valve body is movable relative to the housing. The adjustable constant flow valve further includes a first limiting member and a second limiting member, the first limiting member and the second limiting member are installed on the housing, and the first valve body is provided with a first mating part and a second mating part; When the first limiting member engages with the first mating part, the airflow channel is in the first gear position; when the second limiting member engages with the second mating part, the airflow channel is in the second gear position.

10. The adjustable constant flow valve according to any one of claims 1 to 3, characterized in that, Along the airflow direction, at least a portion of the second valve body is fitted onto the first valve body to form the airflow channel.

11. The adjustable constant flow valve according to claim 10, characterized in that, The adjustable constant flow valve also includes a third limiting member, which is connected to the second valve body. The first valve body is provided with a third mating part and a fourth mating part. When the third limiting member engages with the third mating part, the airflow channel is in the first gear position; when the third limiting member engages with the fourth mating part, the airflow channel is in the second gear position.

12. The adjustable constant flow valve according to claim 11, characterized in that, The second valve body is provided with a receiving groove, and the third limiting member is disposed in the receiving groove; During the movement of the first valve body, the third limiting member retracts into the receiving groove; When the airflow channel is in the first gear position or the second gear position, at least a portion of the third limiting member is engaged with the third mating part or the fourth mating part.

13. A testing device, characterized in that, The detection equipment includes: An adjustable constant flow valve, wherein the constant flow valve is the adjustable constant flow valve according to any one of claims 1 to 12; A detection device is used to detect the gas passing through the constant flow valve.

Images