Air pressure differential alarm

Abstract

The utility model discloses an air pressure difference alarm, including casing, end cover, pressure diaphragm, elastic force adjusting mechanism, micro -switch, first interface and second interface, the end cover buckle is on casing and is formed first cavity and second cavity through pressure diaphragm separation, first interface and second interface are used respectively to connect external gas source, and first interface intercommunication first cavity, and second interface intercommunication second cavity, elastic force adjusting mechanism includes setting in the pressure tablet of first cavity, be used for triggering the top rod of micro -switch, pivot, spring and adjusting shaft. Adopt above -mentioned technical scheme, the utility model discloses an air pressure difference alarm, through the adjustment head of rotation exposure, drive the sliding block of screw connection to remove to change the pre -tightening force of spring. This makes the same switch to be able to adapt to the application of different pressure difference range, need not because range mismatch and frequently change different model switch.

Description

Technical Field

[0001] This utility model relates to an air differential pressure alarm, belonging to the technical field of air differential pressure alarms. Background Technology

[0002] An air differential pressure alarm is a switching device that switches states by detecting changes in the gas pressure difference between two pressure ports. It is commonly used for status alarms or switching electrical control circuits, and is particularly suitable for applications such as HVAC (heating, ventilation, and air conditioning) system air pressure control, power plant furnace negative pressure monitoring, fluid machinery protection, and pressure safety interlocking of drying equipment. Traditional mechanical air differential pressure alarms generally suffer from insufficient range coverage. For example, in monitoring filter blockage in air conditioning systems, the initial differential pressure may be as low as 250 Pa, while after blockage, the differential pressure can rise to over 3000 Pa. Traditional switches, due to their narrow range, require frequent model changes, resulting in poor system compatibility and high maintenance costs. Therefore, it is necessary to design an air differential pressure alarm with adjustable range. Utility Model Content

[0003] Therefore, the purpose of this utility model is to provide an air pressure differential alarm with adjustable range.

[0004] To achieve the above objectives, this utility model provides an air differential pressure alarm, comprising a housing, an end cap, a pressure diaphragm, a spring adjustment mechanism, a micro switch, a first interface, and a second interface. The end cap is fastened to the housing, and the outer edge of the pressure diaphragm is clamped and fixed by the end cap and the housing, thereby dividing the internal space enclosed by the end cap and the housing into a first cavity and a second cavity, wherein the first cavity is located near the housing, and the second cavity is located near the end cap. The first interface and the second interface are used to connect to external air sources, with the first interface connecting to the first cavity and the second interface connecting to the second cavity. The elastic adjustment mechanism includes a pressure plate disposed in the first cavity, a push rod for triggering the micro switch, a rotating shaft, a spring, and an adjusting shaft. The pressure plate is mounted on the housing via the rotating shaft. The pressure diaphragm is located on one side of the pressure plate, and the push rod is fixed to the other side of the pressure plate. One end of the pressure plate is connected to the spring, and the spring is connected to a slider. The slider is located in a groove on the housing. The adjusting shaft is rotatably mounted on the housing. One end of the adjusting shaft is provided with an adjusting head, and the other end is a threaded end. The adjusting head extends to the outside of the housing, and the threaded end is screwed onto the slider.

[0005] The first interface and the second interface are disposed on the housing. The housing is also provided with a first air passage and a second air passage. The first air passage connects the first interface and the first cavity, and the second air passage connects the second interface and the second cavity.

[0006] A through hole is provided on the edge of the pressure diaphragm and on the part clamped by the housing and the end cap. The two ends of the second air passage are connected to the second interface and the through hole. A gasket is provided below the through hole, and a vent tube is provided on the gasket and inserted into the through hole. A platform for supporting the gasket is provided on the end cap and below the gasket. A vent groove is provided on the platform, and the two ends of the vent groove are connected to the lower end of the vent tube and the second cavity.

[0007] The slider includes a square plate and a connecting post connected to the square plate. The spring is connected to the connecting post, and the slide groove is a square groove that mates with the square plate.

[0008] The housing is provided with a shaft hole for the adjustment shaft to pass through, and a baffle is provided on the adjustment shaft. The adjustment head and the baffle are clamped on both sides of the shaft hole.

[0009] The housing is provided with an opening slot for inserting a rotating shaft and multiple screw holes for screwing in anti-loosening screws. The screw holes are opened on the side of the opening slot, and anti-loosening screws are installed in the screw holes. The cap of the anti-loosening screw presses against the outside of the rotating shaft, thereby preventing it from coming out of the opening slot.

[0010] A rigid reinforcing sheet is provided on the pressure diaphragm and on the side closest to the pressure plate.

[0011] The pressure diaphragm is a circular silicone diaphragm. The pressure diaphragm includes a diaphragm body and a convex ring located on the outer circumference of the diaphragm body. The housing is provided with a receiving groove for accommodating the convex ring. One end of the convex ring enters into the receiving groove, and the other end of the convex ring is pressed against the other end of the convex ring.

[0012] The diaphragm body includes a mounting portion in the middle and a wavy portion on the outside of the mounting portion. The reinforcing sheet is mounted on the mounting portion, and the wavy portion includes at least one concave or convex portion.

[0013] A hole base block is provided on the radial inner side of the convex ring, the hole base block is connected to the convex ring, and the through hole is formed on the hole base block.

[0014] By adopting the above technical solution, the air differential pressure alarm of this utility model has the following advantages compared with the prior art:

[0015] 1. By rotating the exposed adjusting head, the threaded slider moves, thereby changing the spring preload. This allows the same switch to adapt to applications with different differential pressure ranges, eliminating the need for frequent replacements of different switch models due to range mismatches. Since a single model can cover a wide differential pressure range, it greatly improves the compatibility of the equipment with different systems or operating conditions, reduces the types and inventory of spare parts, and thus lowers the overall system maintenance cost.

[0016] 2. The design of the slider and the square groove effectively prevents the slider from rotating or tilting during adjustment, ensuring the linearity and accuracy of the spring force adjustment, thus making the switching action point more precise. The rotating shaft is limited by anti-loosening screws to prevent it from coming out of the opening slot, allowing the spring force adjustment mechanism to be assembled as a module, making installation relatively simple.

[0017] 3. The pressure diaphragm edge is firmly clamped by the structure of the convex ring and receiving groove, providing good sealing and preventing air leakage between the two chambers. At the same time, a unique ventilation path is designed for the second chamber (second interface → second air passage → through hole → vent pipe → vent groove → second chamber), ensuring that the pressure can be effectively and reliably transmitted to the second chamber side of the diaphragm.

[0018] 4. A rigid reinforcing sheet is placed in the middle of the diaphragm to prevent excessive local stress or deformation, effectively extending the diaphragm's service life. The "wavy" design (pleated structure) of the diaphragm body makes it easier to deform under low pressure differentials, improving the product's sensitivity.

[0019] 5. The adjustment head is located on the outside of the housing, so users can adjust the range using tools (such as screwdrivers) without opening the housing, making the operation simple and quick.

[0020] In summary, this utility model achieves a wide-range, adjustable measurement range through an innovative elastic adjustment mechanism, solving the core pain point of insufficient range coverage in traditional mechanical air differential pressure alarms. Furthermore, a series of structural designs ensure the accuracy of adjustment, the reliability of operation, and the convenience of use, ultimately achieving comprehensive benefits such as improved compatibility and reduced costs. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the structure of this utility model.

[0022] Figure 2 for Figure 1 Another perspective diagram.

[0023] Figure 3 This is an exploded view of the present invention.

[0024] Figure 4 This is a cross-sectional view of the present invention.

[0025] Figure 5 This is a cross-sectional view of the present invention from another angle.

[0026] Figure 6 This is a schematic diagram of the gasket and the platform.

[0027] Figure 7 This is a schematic diagram of the assembly structure of the elastic adjustment mechanism.

[0028] Figure 8 This is a schematic diagram of the elastic adjustment mechanism.

[0029] Figure 9 This is a schematic diagram of the structure of the shell of this utility model after partial cross-section.

[0030] Figure 10 This is an exploded view of the adjusting shaft and slider. Detailed Implementation

[0031] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0032] like Figures 1-3 As shown, the air differential pressure alarm of this utility model includes a housing 1, an end cap 2, a pressure diaphragm 3, an elastic adjustment mechanism 4, a micro switch 5, a first interface 6, and a second interface 7.

[0033] The end cap 2 is fastened to the housing 1, and the outer edge of the pressure diaphragm 3 is clamped and fixed by the end cap 2 and the housing 1, so that the pressure diaphragm 3 divides the internal space enclosed by the end cap 2 and the housing 1 to form a first cavity 100 and a second cavity 200, wherein the first cavity 100 is located on the side closer to the housing 1, and the second cavity 200 is located on the side closer to the end cap 2; the first interface 6 and the second interface 7 are used to connect to an external air source respectively, the first interface 6 is connected to the first cavity 100, and the second interface 7 is connected to the second cavity 200.

[0034] like Figure 4 , Figure 5 As shown, the pressure diaphragm 3 is a circular silicone diaphragm, and a rigid reinforcing sheet 8 is provided on the pressure diaphragm 3 and on the side near the pressure plate 41. The pressure diaphragm 3 includes a diaphragm body 31 and a protruding ring 32 located on the outer circumference of the diaphragm body 31. The housing 1 is provided with a receiving groove 101 for accommodating the protruding ring 32. One end of the protruding ring 32 enters into the receiving groove 101, and the other end of the protruding ring 32 is pressed against the other end of the housing 1. The diaphragm body 31 includes a mounting portion 310 located in the middle and a corrugated portion 311 located outside the mounting portion 310. The reinforcing sheet 8 is mounted on the mounting portion 310. The corrugated portion 311 includes at least one concave portion or an arched portion. For example, in this embodiment, the corrugated portion 311 includes only one arched portion.

[0035] In this embodiment, the first interface 6 and the second interface 7 are disposed on the housing 1, and the housing 1 is also provided with a first air passage 102 and a second air passage 103.

[0036] The first airway 102 is connected to the first interface 6 and the first cavity 100.

[0037] The second air passage 103 connects to the second interface 7 and the second cavity 200. A through hole 330 is provided on the edge of the pressure diaphragm 3, specifically on the portion held by the housing 1 and the end cap 2. More specifically, a hole base block 33 is provided radially inside the convex ring 32, and the hole base block 33 is connected to the convex ring 32. The through hole 330 is formed on the hole base block 33. Both ends of the second air passage 103 connect to the second interface 7 and the through hole 330. A gasket 9 is provided below the through hole 330, and a vent tube 91 inserted into the through hole 330 is provided on the gasket 9. Figure 6 As shown, a platform 201 for supporting the gasket 9 is provided on the end cap 2 and below the gasket 9. A venting groove 202 is formed on the platform 201, and both ends of the venting groove 202 are connected to the lower end of the vent pipe 91 and the second cavity 200. The gasket 9 can support the silicone hole base block 33, preventing the hole base block 33 from pressing firmly onto the platform 201 and thus sealing the venting groove 202, preventing airflow.

[0038] like Figures 7-10 As shown, the elastic adjustment mechanism 4 includes a pressure plate 41 disposed in the first cavity 100, a push rod 42 for triggering the micro switch 5, a rotating shaft 43, a spring 44, and an adjusting shaft 45. The pressure plate 41 is mounted on the housing 1 via the rotating shaft 43. The pressure diaphragm 3 is located on one side of the pressure plate 41, and the push rod 42 is fixed to the other side of the pressure plate 41. After the pressure diaphragm 3 drives the reinforcing plate 8 to move, it can squeeze the pressure plate 41, thereby allowing the push rod 42 on the pressure plate 41 to touch the contact plate of the micro switch 5.

[0039] One end of the pressure plate 41 is connected to the spring 44, and the spring 44 is connected to a slider 46. The slider 46 is located in a groove 105 on the housing 1. The adjusting shaft 45 is rotatably mounted on the housing 1. One end of the adjusting shaft 45 is provided with an adjusting head 451, and the other end is a threaded end 452. The adjusting head 451 extends to the outside of the housing 1, and the threaded end 452 is screwed onto the slider 46. In this embodiment, the slider 46 includes a square plate 461 and a connecting post 462 connected to the square plate 461. The spring 44 is connected to the connecting post 462, and the groove 105 is a square groove that mates with the square plate 461.

[0040] The housing 1 is provided with a shaft hole 106 for the adjustment shaft 45 to pass through, and a baffle 453 is provided on the adjustment shaft 45. The adjustment head 451 and the baffle 453 are clamped on both sides of the shaft hole 106.

[0041] The housing 1 is provided with an opening groove 107 for inserting the rotating shaft 43 and a plurality of screw holes 108 for screwing in the anti-loosening screw 10. The screw holes 108 are opened on the side of the opening groove 107. The anti-loosening screw 10 is provided in the screw hole 108. The cap 10a of the anti-loosening screw 10 presses against the outside of the rotating shaft 43, thereby preventing it from coming out of the opening groove 107.

[0042] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the protection scope of this invention.

Claims

1. An air differential pressure alarm characterized by: The device includes a housing, an end cap, a pressure diaphragm, a spring adjustment mechanism, a micro switch, a first interface, and a second interface. The end cap is fastened to the housing, and the outer edge of the pressure diaphragm is clamped and fixed by the end cap and the housing, thereby dividing the internal space enclosed by the end cap and the housing into a first cavity and a second cavity. The first cavity is located on the side closer to the housing, and the second cavity is located on the side closer to the end cap. The first interface and the second interface are used to connect to an external air source, with the first interface connecting to the first cavity and the second interface connecting to the second cavity. The spring adjustment mechanism includes a pressure plate disposed in the first cavity, a push rod for triggering the micro switch, a rotating shaft, a spring, and an adjustment shaft. The pressure plate is mounted on the housing via the rotating shaft, the pressure diaphragm is located on one side of the pressure plate, the push rod is fixed to the other side of the pressure plate, one end of the pressure plate is connected to the spring, the spring is connected to a slider, the slider is located in a groove on the housing, and the adjustment shaft is rotatably mounted on the housing. One end of the adjustment shaft is provided with an adjustment head, and the other end is a threaded end. The adjustment head extends to the outside of the housing, and the threaded end is screwed onto the slider.

2. The air differential alarm of claim 1, wherein: The first interface and the second interface are disposed on the housing. The housing is also provided with a first air passage and a second air passage. The first air passage connects the first interface and the first cavity, and the second air passage connects the second interface and the second cavity.

3. The air differential alarm of claim 2, wherein: A through hole is provided on the edge of the pressure diaphragm and on the part clamped by the housing and the end cap. The two ends of the second air passage are connected to the second interface and the through hole. A gasket is provided below the through hole, and a vent tube is provided on the gasket and inserted into the through hole. A platform for supporting the gasket is provided on the end cap and below the gasket. A vent groove is provided on the platform, and the two ends of the vent groove are connected to the lower end of the vent tube and the second cavity.

4. The air pressure differential alarm as described in claim 1, characterized in that: The slider includes a square plate and a connecting post connected to the square plate. The spring is connected to the connecting post, and the slide groove is a square groove that mates with the square plate.

5. The air differential pressure alarm as described in claim 4, characterized in that: The housing is provided with a shaft hole for the adjustment shaft to pass through, and a baffle is provided on the adjustment shaft. The adjustment head and the baffle are clamped on both sides of the shaft hole.

6. The air differential pressure alarm as described in claim 1, characterized in that: The housing is provided with an opening slot for inserting a rotating shaft and multiple screw holes for screwing in anti-loosening screws. The screw holes are opened on the side of the opening slot, and anti-loosening screws are installed in the screw holes. The cap of the anti-loosening screw presses against the outside of the rotating shaft, thereby preventing it from coming out of the opening slot.

7. The air differential pressure alarm as described in claim 1, characterized in that: A rigid reinforcing sheet is provided on the pressure diaphragm and on the side closest to the pressure plate.

8. The air differential pressure alarm as described in any one of claims 1-7, characterized in that: The pressure diaphragm is a circular silicone diaphragm. The pressure diaphragm includes a diaphragm body and a convex ring located on the outer circumference of the diaphragm body. The housing is provided with a receiving groove for accommodating the convex ring. One end of the convex ring enters into the receiving groove, and the other end of the convex ring is pressed against the other end of the convex ring.

9. The air differential pressure alarm as described in claim 8, characterized in that: The diaphragm body includes a mounting portion in the middle and a wavy portion on the outside of the mounting portion. The reinforcing sheet is mounted on the mounting portion, and the wavy portion includes at least one concave or convex portion.

10. The air pressure differential alarm as described in claim 8, characterized in that: A hole base block is provided on the radial inner side of the convex ring. The hole base block is connected to the convex ring and a through hole is provided on the hole base block.

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