Dead band adjustment mechanism and pressure switch

Abstract

The utility model relates to pressure switch technical field discloses a kind of dead zone adjusting mechanism and pressure switch, dead zone adjusting mechanism includes top rod: top rod is used to trigger microswitch;Lever: lever is set on the action path of top rod, lever is rotatably installed;Sub pressure difference adjusting mechanism: including support surface, pressure difference spring and pressure difference adjusting assembly, pressure difference spring one end is used to contact with support surface, the distance of pressure difference spring for the end of contact with support surface and lever rotation center is greater than the distance of top rod and lever rotation center;By being provided with dead zone adjusting mechanism, when pressure rises, distance adjusting screw is topped to microswitch action position, so that pressure difference spring force is completely acted on lever end;When pressure drops, microswitch returns to reset position, pressure difference spring force is completely acted on the support surface of pressure difference screw rod, and lever is not acted, and the compression amount of pressure difference spring is adjusted by the pressure difference nut on pressure difference screw rod to realize that dead zone is widely adjustable.

Description

Technical Field

[0001] This utility model relates to the field of pressure switch technology, specifically to a dead zone adjustment mechanism and a pressure switch. Background Technology

[0002] The dead zone of a pressure switch refers to the pressure value that must be exceeded before the switch can be activated or deactivated during pressure fluctuations. The size of the dead zone has a significant impact on the accuracy and stability of the pressure switch.

[0003] Traditional industrial pressure switches have no adjustable dead zone or require special microswitches to achieve a small range of dead zone adjustment, which is not only costly but also only allows for pressure setting within 10%.

[0004] In addition, the "push rod" of the actuating part at the front end of the traditional micro switch has a distance in the axial space that is not effectively constrained, resulting in poor overall vibration resistance of the switch. Under strong vibration conditions, the push rod is prone to accidentally triggering the micro switch.

[0005] This application is submitted in response to the above-mentioned problems. Utility Model Content

[0006] The purpose of this utility model is to provide a dead zone adjustment mechanism and pressure switch to overcome the problems of traditional differential pressure switches having no adjustable dead zone or a small dead zone adjustment range and high cost.

[0007] This utility model is achieved through the following technical solution.

[0008] This utility model provides a dead-zone adjustment mechanism, comprising:

[0009] Push rod: The push rod is used to trigger the micro switch. When the pressure rises, the push rod moves to trigger the micro switch. When the pressure drops, the push rod disengages from the micro switch and resets.

[0010] Lever: The lever is set in the action path of the push rod. The lever is rotated and connected to the lever shaft at one end, and the other end extends to the lower side of the pressure difference spring.

[0011] The secondary differential pressure adjustment mechanism includes a support surface, a differential pressure spring, and a differential pressure adjustment component. One end of the differential pressure spring is used to directly or indirectly contact the support surface. The distance between the end of the differential pressure spring that contacts the support surface and the rotation center of the lever is greater than the distance between the push rod and the rotation center of the lever, thereby amplifying the movement difference on one side of the differential pressure spring. This facilitates the adjustment of the two force states of the differential pressure spring, ultimately achieving a wide range of adjustable dead zones for the pressure switch. The differential pressure adjustment component is used to adjust the compression of the differential pressure spring, achieving a wide range of adjustable dead zones.

[0012] The lever has two states: the active state and the reset state.

[0013] When the push rod triggers the micro switch, the lever enters the operating state. In the operating state, the lever rotates due to the push of the push rod, and the lever pushes the differential pressure spring out of contact with the support surface. This causes the differential pressure spring force to act entirely on the lever, which is included in the switch's "upper pressure value".

[0014] When the push rod disengages from the microswitch and resets, the lever enters the reset state. In the reset state, the lever rotates to reset, the differential pressure spring falls back to contact the support surface, and separates from the lever. At this time, the force of the differential pressure spring no longer acts on the lever, so it is not included in the switch's "downward pressure value". The dead zone of the switch is equal to the "upward pressure value" minus the "downward pressure value". The dead zone can be adjusted over a wide range by adjusting the compression of the differential pressure spring through the differential pressure adjustment component.

[0015] Furthermore, the secondary differential pressure regulating mechanism also includes a differential pressure screw, the support surface is disposed on the differential pressure screw, the differential pressure adjusting assembly includes a differential pressure nut, the differential pressure nut is installed on the differential pressure screw, and the differential pressure spring is disposed between the differential pressure nut and the support surface. By rotating the differential pressure nut, its position on the differential pressure screw can be adjusted to achieve the adjustment of the compression of the differential pressure spring, thereby achieving the effect of a wide range of adjustable dead zone.

[0016] Furthermore, the differential pressure spring is connected to a spring pressure plate, which is used to contact the support surface and the lever. The spring pressure plate increases the contact area between the differential pressure spring and the support surface or the lever, thereby improving the stability during contact and operation.

[0017] Furthermore, the differential pressure spring is mounted on the differential pressure screw, which improves the structural integration, reduces the structural volume, and facilitates the installation of the differential pressure spring.

[0018] Furthermore, the lever is provided with a through hole through which the differential pressure screw passes. The diameter of the through hole is larger than the diameter of the differential pressure screw, allowing one end of the lever to move freely. This structural design can further improve the compactness of the structure and further reduce the structural volume.

[0019] A pressure switch includes the aforementioned dead zone adjustment mechanism, pressure sensing mechanism, and micro switch. The pressure sensing mechanism is connected to a push rod and is used to drive the push rod to trigger the micro switch when the pressure changes.

[0020] Furthermore, the push rod is connected to an adjustable telescopic body, and the length of the adjustable telescopic body can be adjusted to adjust the stroke required by the push rod to trigger the micro switch.

[0021] Preferably, when the push rod triggers the micro switch, it pushes the lever to a horizontal position.

[0022] Furthermore, the adjustable telescopic body employs an adjustable screw.

[0023] In this design, the push rod and the adjusting screw are divided into two independent parts. This is mainly because the operating position (OP) tolerance of the micro switch is about ±0.4mm, so the clearance of the "front-end actuating part" of the micro switch also needs to be adjusted accordingly. The top of the part that pushes the lever needs to be designed to be in a relatively fixed position because the switch stroke is relatively fixed. The ideal and stable scenario is when the top of the part pushes the lever to the horizontal position and triggers the operating position of the micro switch. Therefore, this "front-end actuating part" is divided into two independent parts: the push rod and the adjusting screw.

[0024] Furthermore, the pressure switch also includes a pressure regulating mechanism, which includes a pressure regulating bolt and a pressure regulating spring. One end of the pressure regulating spring is connected to the transmission disk, and the other end is connected to the pressure regulating bolt. The pressure regulating bolt is used to adjust the pressure of the pressure regulating spring on the transmission disk.

[0025] To address the issue in existing pressure switches where the push rod has a section without effective constraint, resulting in poor overall vibration resistance and the risk of accidental triggering of the microswitch under strong vibration conditions, this design incorporates a pressure sensing mechanism consisting of a diaphragm and a transmission disc. The transmission disc is fixedly connected to the push rod, and the gap between it and the microswitch is adjusted by an adjusting screw, ensuring both high switching performance and high pressure resistance. In this way, the transmission disc, push rod, and adjusting screw are fixedly connected, and the transmission disc is pressed against the pressure sleeve by a pressure regulating spring. Only when the pressure increases can the transmission disc, push rod, and adjusting screw move, effectively preventing accidental triggering of the microswitch under strong vibration conditions. This design significantly improves the switch's vibration resistance.

[0026] The beneficial effects of this utility model are as follows: By setting a dead zone adjustment mechanism, when the pressure rises and the adjusting screw reaches the microswitch's operating position, the top of the push rod pushes the lever and ensures that the lever lifts the spring pressure plate, effectively separating it from the support surface of the differential pressure screw. This allows the differential pressure spring force to act entirely on the lever end, which is included in the switch's "upper pressure value." When the pressure drops and the microswitch returns to the reset position, the spring pressure plate has fallen back to the support surface of the differential pressure screw and ensures effective separation from the lever. The differential pressure spring force acts entirely on the support surface of the differential pressure screw and has no effect on the lever, therefore it is not included in the switch's "lower pressure value." The size of the switch dead zone is equal to the "upper pressure value" minus the "lower pressure value." The dead zone can be adjusted over a wide range by adjusting the compression of the differential pressure spring through the differential pressure nut on the differential pressure screw.

[0027] By setting the "front-end actuating part" of the micro switch into two independent parts, namely the push rod and the adjusting screw, it is convenient to adjust parameters such as the actuating position tolerance of the micro switch. The lever will not be pushed when adjusting the gap between the push rod and the micro switch, ensuring that the micro switch is triggered precisely when the lever is pushed to the horizontal position.

[0028] By fixing the transmission disc to the push rod and threading an adjusting screw to the top of the push rod, the gap between the screw and the micro switch is adjusted to ensure both the switching performance and high pressure resistance. The transmission disc is also pressed against the pressure sleeve by the pressure regulating spring. Only when the pressure rises can the transmission disc, push rod and adjusting screw be driven to move. This effectively avoids the micro switch being accidentally triggered under strong vibration conditions and improves the vibration resistance of the switch. Attached Figure Description

[0029] To more clearly illustrate the technical solutions in the embodiments of the utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0030] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0031] Figure 1 This is a schematic diagram of the overall structure of the pressure switch;

[0032] Figure 2 A schematic diagram showing the spring plate disengaging from the support surface when the micro switch is triggered;

[0033] Figure 3 This is a schematic diagram showing the spring plate falling back to the support surface and separating from the lever when the micro switch is reset. Detailed Implementation

[0034] The following is combined with Figures 1-3 This utility model will be described in detail.

[0035] Example 1:

[0036] The pressure switch of this utility model, such as Figure 1 It includes a housing, a base 3 connected to the housing, a dead zone adjustment mechanism, a pressure sensing mechanism, a pressure regulating mechanism, and a micro switch 25.

[0037] The pressure sensing mechanism is connected to the push rod 8 and is used to drive the push rod 8 to trigger the micro switch 25 when the pressure changes.

[0038] In this embodiment, the pressure sensing mechanism includes a base 1, a diaphragm 4, a transmission disk 6, a sealing ring 2, and a pressure sleeve 5. The pressure sleeve 5, diaphragm 4, transmission disk 6, sealing ring 2, and base 1 are installed in the base 3. The diaphragm 4 and sealing ring 2 are located between the pressure sleeve 5 and the base 1. The transmission disk 6 can contact the diaphragm 4 and the pressure sleeve 5.

[0039] The micro switch 25 is installed in the housing, and the housing is provided with anti-vibration cardboard 26 around the micro switch 25.

[0040] The push rod 8 is connected to an adjustable telescopic body. Adjusting the length of the adjustable telescopic body allows for adjustment of the stroke required to trigger the micro switch 25. In this embodiment, the adjustable telescopic body uses an adjustable screw 30. In other embodiments, a telescopic rod or other structure capable of adjusting the length can be used.

[0041] When a pressurized medium acts on the diaphragm 4 through the air inlet of the connector 1, the diaphragm 4 pushes the transmission disk 6 by displacement. The transmission disk is equipped with a push rod 8, and the push rod 8 is equipped with an adjusting screw 30 until the adjusting screw pushes the micro switch to activate.

[0042] In other embodiments, the diaphragm 4 can be replaced with other types of sealed sensing elements such as bellows or plungers.

[0043] like Figure 1 The pressure regulating mechanism includes a pressure regulating bolt 13 and a pressure regulating spring 7. One end of the pressure regulating spring 7 rests against the near end of the transmission disk 6. A spring washer 28 is provided between the transmission disk 6 and the pressure regulating spring 7. The other end of the pressure regulating spring 7 rests against the pressure regulating bolt 13. The pressure regulating bolt 13 is installed in the bolt hole in the housing. The switching pressure is regulated by adjusting the amount of compression of the pressure regulating spring 7 by the pressure regulating bolt 13.

[0044] To address the issue in existing pressure switches where the push rod has a section without effective constraint, resulting in poor overall vibration resistance and the risk of accidental triggering of the micro switch under strong vibration conditions, the transmission disc 6 is riveted to the push rod 8 for a fixed connection. The gap between the transmission disc 6 and the micro switch 25 is adjusted using the adjusting screw 30, ensuring both switch operation performance and high pressure resistance. In this way, the transmission disc 6, push rod 8, and adjusting screw 30 are fixedly connected, and the transmission disc 6 is pressed against the pressure sleeve 5 by the pressure regulating spring 7. Only when the pressure increases can the transmission disc 6, push rod 8, and adjusting screw 30 move, effectively preventing accidental triggering of the micro switch under strong vibration conditions. This design significantly improves the switch's vibration resistance.

[0045] Preferably, when the push rod 8 triggers the micro switch 25, it pushes the lever 17 to the horizontal position.

[0046] In this embodiment, the front-end actuating component is divided into two independent parts: the push rod 8 and the adjusting screw 30. This is mainly because the operating position (OP) tolerance of the micro switch 25 is about ±0.4mm, so the clearance of the "front-end actuating component" of the micro switch 25 also needs to be adjusted accordingly. The top of the component that pushes the lever 17 to move needs to be designed to be in a relatively fixed position because the switch stroke is relatively fixed. The ideal and stable scenario is that when the top of the component pushes the lever to the horizontal position, it triggers the operating position of the micro switch. Therefore, this "front-end actuating component" is divided into two independent parts: the push rod 8 and the adjusting screw 30. This makes it easier to match the operating position tolerance and other parameters of the micro switch 25 for adjustment, and will not push the lever due to adjusting the clearance between the push rod and the micro switch.

[0047] The dead zone adjustment mechanism includes top rod 8, lever 17 and secondary differential pressure adjustment mechanism.

[0048] In this solution, a lever mechanism (lever 17 and lever shaft 16) is added to achieve a wide range of adjustable dead zone of the switch. To achieve adjustable dead zone of the pressure switch, a secondary differential pressure spring (i.e., differential pressure spring 19, used for dead zone adjustment) needs to be added to the main adjusting spring (i.e., adjusting spring 7). At the same time, it is necessary to ensure that the secondary differential pressure spring is active when the microswitch is activated, but inactive when the microswitch is reset. Only in this way can a wide range of adjustable dead zone of the switch be achieved. However, the movement difference (the movement distance or angle from the active position of the drive rod to the reset position) of conventional microswitches is generally small, ≤0.1mm. It is very difficult to achieve two force states of the secondary differential pressure spring within such a small range. Therefore, a lever mechanism (a single-sided lever that also takes into account the compactness of the switch) is introduced. By amplifying the movement difference on the secondary differential pressure spring side by about 3 times through the lever arm, it is easy to achieve the two force states of the secondary differential pressure spring, and finally achieve a wide range of adjustable dead zone of the pressure switch.

[0049] Specifically, such as Figure 2 , Figure 3 The push rod 8 is used to trigger the micro switch. When the pressure rises, the push rod 8 moves to trigger the micro switch. When the pressure drops, the push rod 8 disengages from the micro switch and resets.

[0050] like Figure 2 , Figure 3 The lever 17 is set on the action path of the top rod 8. The lever 17 is rotatably mounted, with one end connected to the lever shaft 16. The lever shaft 16 is mounted on the base mounting post 31 set on the housing, and the other end extends to the lower side of the differential pressure spring 19. The lever 17 is provided with a through hole, and the adjusting screw 30 is set through the through hole. The diameter of the through hole is larger than the diameter of the adjusting screw 30.

[0051] The secondary differential pressure adjustment mechanism includes a support surface 32, a differential pressure spring 19, and a differential pressure adjustment assembly. One end of the differential pressure spring 19 is used to contact the support surface 32, and the differential pressure adjustment assembly is used to adjust the compression of the differential pressure spring 19 to achieve a wide range of adjustable dead zones.

[0052] The distance between the end of the differential pressure spring 19 that contacts the support surface 32 and the rotation center of the lever 17 is greater than the distance between the top rod 8 and the rotation center of the lever 17.

[0053] In this embodiment, the support surface 32 is disposed on the differential pressure screw 23, the differential pressure screw 23 is mounted on the base mounting column 31 and fixed by the fastening nut 15. The differential pressure adjustment assembly includes a differential pressure nut 22, which is mounted on the differential pressure screw 23. A differential pressure spring 19 is disposed between the differential pressure nut 22 and the support surface 32. Preferably, the differential pressure spring 19 is fitted onto the differential pressure screw 23 to improve structural integration, reduce structural volume, and facilitate the positioning and installation of the differential pressure spring 19. Both ends of the differential pressure spring 19 are connected to the spring pressure plate 20. The differential pressure spring 19 indirectly contacts the differential pressure nut 22 and the support surface 32 (or lever 17) through the spring pressure plate 20. The spring pressure plate 20 increases the contact area between the differential pressure spring 19 and the support surface 32 or the lever 17, thereby improving the stability during contact and operation.

[0054] like Figure 2 , Figure 3 The lever 17 also has a through hole through which the differential pressure screw 23 passes. The diameter of the through hole is larger than the diameter of the differential pressure screw 23, allowing one end of the lever 17 to move freely. This structural design can further improve the compactness of the structure and further reduce the volume of the structure.

[0055] Rotate the differential pressure nut 22 to adjust its position on the differential pressure screw 23, thereby adjusting the compression of the differential pressure spring 19 and achieving a wide range of adjustable dead zone.

[0056] Lever 17 has two states: active state and reset state.

[0057] like Figure 2 When the pressure increases, the adjusting screw 30 on the push rod 8 reaches the microswitch activation position, triggering the microswitch. At this point, lever 17 enters the activated state. Figure 2 As shown at point A, in the operating state: lever 17 rotates due to the push of top rod 8, and the top of lever 17 pushes up spring pressure plate 20, causing spring pressure plate 20 to disengage from the support surface 32 of differential pressure screw 23. At this time, the force of differential pressure spring 19 is fully applied to lever 17, which is included in the switch "upper pressure value".

[0058] like Figure 3 When the pressure drops and the push rod 8 disengages from the microswitch and resets, as... Figure 3As shown at point D, lever 17 enters the reset state. In the reset state, lever 17 rotates to reset, and spring plate 20 falls back to contact the support surface 32, ensuring effective separation from lever 17. At this time, the force of differential pressure spring 19 acts entirely on the support surface 32 of differential pressure screw 23 and no longer acts on lever 17. Therefore, it has no effect on lever 17 and is not included in the switch "downward pressure value".

[0059] The dead zone of the switch is equal to the "upper pressure value" minus the "lower pressure value". The dead zone can be adjusted over a wide range by adjusting the compression of the differential pressure spring through the differential pressure adjustment component.

[0060] The differential pressure screw 23 is threadedly connected to the base mounting post. The above action is ensured by adjusting the height of the support surface of the differential pressure screw 23 (the adjustment range is expanded to 3 times the movement difference of the micro switch for better adjustment), and then the fastening nut 15 is used to lock and fix it.

[0061] Example 2:

[0062] Unlike in Example 1, this example does not include a dead-zone adjustment mechanism. Without the dead-zone adjustment mechanism, the pressure switch does not have a dead-zone adjustment function, but it can still perform basic functions and is suitable for users who do not require a dead-zone adjustment function.

[0063] The above embodiments are only for illustrating the technical concept and features of this utility model, and are intended to enable those skilled in the art to understand and implement the content of this utility model. They should not be construed as limiting the scope of protection of this utility model. All equivalent changes or modifications made in accordance with the spirit and essence of this utility model should be covered within the scope of protection of this utility model.

Claims

1. A dead-zone adjustment mechanism, characterized in that: include: Push rod (8): Push rod (8) is used to trigger the micro switch; Lever (17): The lever (17) is set on the action path of the top rod (8), and the lever (17) is rotated; The secondary differential pressure adjustment mechanism includes a support surface (32), a differential pressure spring (19), and a differential pressure adjustment assembly. One end of the differential pressure spring (19) is used to contact the support surface (32). The distance between the end of the differential pressure spring (19) that is in contact with the support surface (32) and the rotation center of the lever (17) is greater than the distance between the top rod (8) and the rotation center of the lever (17). The differential pressure adjustment assembly is used to adjust the compression of the differential pressure spring (19) to achieve a wide range of adjustable dead zones. The lever (17) has two states: the active state and the reset state. When the push rod (8) triggers the micro switch, the lever (17) enters the action state. In the action state, the lever (17) rotates due to the push of the push rod (8), and the lever (17) pushes the differential pressure spring (19) to disengage from the support surface (32). At this time, the force of the differential pressure spring (19) is fully applied to the lever (17). When the push rod (8) is disengaged from the micro switch reset, the lever (17) enters the reset state. In the reset state, the lever (17) rotates to reset, the differential pressure spring (19) falls back to contact the support surface (32) and separates from the lever (17). At this time, the force of the differential pressure spring (19) no longer acts on the lever (17).

2. The dead-zone adjustment mechanism according to claim 1, characterized in that: The secondary differential pressure regulating mechanism also includes a differential pressure screw (23), the support surface (32) is disposed on the differential pressure screw (23), the differential pressure adjusting assembly includes a differential pressure nut (22), the differential pressure nut (22) is installed on the differential pressure screw (23), and the differential pressure spring (19) is disposed between the differential pressure nut (22) and the support surface (32).

3. The dead-zone adjustment mechanism according to claim 2, characterized in that: The differential pressure spring (19) is connected to the spring pressure plate (20).

4. The dead-zone adjustment mechanism according to claim 2, characterized in that: The differential pressure spring (19) is mounted on the differential pressure screw (23).

5. The dead-zone adjustment mechanism according to claim 4, characterized in that: The lever (17) has a through hole, through which the differential pressure screw (23) passes.

6. A pressure switch, characterized in that: Includes the dead zone adjustment mechanism, pressure sensing mechanism and micro switch (25) as described in any one of claims 1-5, wherein the pressure sensing mechanism is connected to the push rod (8) and is used to drive the push rod (8) to trigger the micro switch (25) when the pressure changes.

7. The pressure switch according to claim 6, characterized in that: The top rod (8) is connected to an adjustable telescopic body. The length of the adjustable telescopic body is adjusted to adjust the stroke required to trigger the micro switch (25) of the top rod (8).

8. The pressure switch according to claim 7, characterized in that: The adjustable telescopic body uses an adjustable screw (30).

9. The pressure switch according to claim 7 or 8, characterized in that: The pressure switch also includes a pressure regulating mechanism, which includes a pressure regulating bolt (13) and a pressure regulating spring (7). One end of the pressure regulating spring (7) is connected to the transmission disc (6), and the other end is connected to the pressure regulating bolt (13).

10. The pressure switch according to claim 9, characterized in that: The pressure sensing mechanism includes a diaphragm (4) and a transmission disk (6). The transmission disk (6) is connected to a push rod (8). When the pressure changes, the diaphragm (4) can drive the transmission disk (6) to move.

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