Liquid level switch with higher reliability

Abstract

The utility model discloses a liquid level switch with higher reliability. The liquid level switch comprises a shell, a circuit board is arranged in the shell and comprises an output board and a control board; two mounting lock catches are arranged at the bottom outside the shell, first to thirty wiring terminals and a lamp indication panel are arranged at the top outside the shell, the first to fifteenth wiring terminals are electrically connected with the control panel, the sixteenth to thirty wiring terminals are electrically connected with the output panel, the output panel is electrically connected with the control panel, the control panel is electrically connected with the lamp indication panel, and the lamp indication panel is electrically connected with the lamp indication panel. The button and the LED lamp on the lamp indication panel are used for checking the function of the liquid level switch and displaying the operation state. According to the utility model, a dual-electrode structure and an anti-false alarm algorithm are adopted, the accuracy and reliability of liquid level detection are effectively improved, and meanwhile, the device also has the practical functions of monitoring flushing bypass time, flexibly configuring a liquid level detection channel and the like, and the intelligent level of liquid level control is further improved.

Description

Technical Field

[0001] The utility model relates to the technical field of liquid level monitoring, in particular to a liquid level switch with higher reliability. Background Art

[0002] Liquid level switches are important safety devices in steam boilers and hot water equipment. Their function is to monitor and control the liquid volume in the system, prevent instrument damage or other safety accidents caused by low liquid levels, and ensure safe operation of the equipment.

[0003] Traditional liquid level switches primarily utilize a single-electrode structure, resulting in relatively low detection accuracy and reliability, making them unable to meet the stringent requirements of modern industry for liquid level control. Furthermore, in certain situations, such as when a ship's turbulence causes a sudden drop in liquid level, an alarm signal alone may not guarantee accurate level detection. False alarm signals can even disrupt personnel's judgment, leading to unpredictable consequences. Utility Model Content

[0004] In order to solve the above problems, the utility model provides a liquid level switch with higher reliability, which can effectively improve the accuracy of liquid level detection, avoid false alarms, and ensure the safe and stable operation of the equipment in complex environments.

[0005] The technical solution of the utility model is as follows:

[0006] A liquid level switch with higher reliability comprises a housing; a circuit board is disposed within the housing, the circuit board comprising an output board and a control board; two mounting latches are disposed on the bottom exterior of the housing; a wiring terminal group and a light indicator panel are disposed on the top exterior of the housing, the wiring terminal group comprising wiring terminals numbered 1 to 30; the light indicator panel comprises two buttons for diagnosis and testing, four operating status indicator lights for notifying operating status, and three diagnostic indicator lights for diagnosis.

[0007] Terminals No. 1 to 15 in the terminal group are electrically connected to the control board, and terminals No. 16 to 30 in the terminal group are electrically connected to the output board. The output board is electrically connected to the control board via an electronic connecting line. The control board is electrically connected to the light indicator panel. The light indicator panel is electrically connected to the diagnostic test button, the operating status indicator light, and the diagnostic indicator light for checking the function of the liquid level switch and displaying the operating status.

[0008] The first to fifth wiring terminals and the ninth to thirteenth wiring terminals in the wiring terminal group are electrically connected to two liquid level electrodes respectively, and are used to receive liquid level signals from the liquid level electrodes.

[0009] The No. 6 and No. 7 wiring terminals and the No. 14 and No. 15 wiring terminals in the wiring terminal group are electrically connected to the monitoring logic unit for monitoring special situations such as flushing bypass.

[0010] The No. 16 and No. 17 wiring terminals in the wiring terminal group are used to access the power supply voltage and work together with the power conversion module on the output board to provide a stable power supply for the circuit.

[0011] Terminals 20 and 21 and terminals 29 and 30 in the terminal group are used to output a 24V alarm signal without delay, with a maximum load of 100mA, and the output signal is activated only when the liquid level is detected to be lower than the set threshold.

[0012] The No. 23 and No. 24 wiring terminals and the No. 26 and No. 27 wiring terminals in the wiring terminal group are electrically connected to the heating device to control the working state of the heating device.

[0013] Specifically, the shell includes an upper cover body and a lower cover body, the connection between the upper cover body and the lower cover body has the same size, the lower cover body is provided with a connecting buckle, and the upper cover body is provided with a connecting hole, and the connecting buckle and the connecting hole are plugged into each other.

[0014] Specifically, the left and right side walls inside the shell are provided with card slots, and the bottom is provided with a clamping block. The card slots and the clamping block are in contact with the circuit board and are used to fix the output board and the control board; the top of the upper cover is provided with a through slot, and the light indicator panel is electrically connected to the control board through the through slot.

[0015] Specifically, a TH 35 type guide rail is provided at the bottom of the housing, and the guide rail is arranged parallel to the circuit board inside the housing.

[0016] Preferably, in dynamic environments such as maritime navigation, turbulence can lead to inaccurate liquid level measurement data. When the liquid sloshes, the level switch may incorrectly determine the remaining liquid level, triggering an alarm and affecting the stable operation of the equipment. Therefore, by deeply analyzing the dynamic characteristics of liquid level changes and targeting complex environments such as maritime navigation, the present invention equips the control panel with a false alarm prevention function that effectively identifies and filters transient fluctuations in liquid level measurement, ensuring the accuracy of measurement results.

[0017] Specifically, the control panel activates a shutdown delay mechanism when the liquid level falls below a set threshold. If the liquid level rises during the shutdown delay period, the alarm is canceled. If the liquid level continues to fall below the minimum level, an alarm is ultimately triggered. This algorithm effectively avoids false alarms caused by liquid sloshing, improving the reliability of liquid level monitoring in complex environments.

[0018] Preferably, the present invention uses a dual-electrode method to detect liquid level, with one electrode serving as a minimum liquid level alarm electrode and the other serving as an auxiliary electrode. When the liquid level falls below the minimum liquid level, the minimum liquid level alarm electrode triggers an alarm signal, and the control board shuts down the safety circuit of the heating device after the shutdown delay expires, preventing damage to the equipment due to water shortage, thereby effectively improving the accuracy and stability of liquid level detection.

[0019] Preferably, the control panel is provided with two coding switches, corresponding to the input signal channels of the two liquid level electrodes respectively. By operating the coding switches, it is possible to independently select whether to enable the input signal of the corresponding liquid level electrode, thereby flexibly configuring the required liquid level detection channel.

[0020] Preferably, in order to monitor the liquid level in real time and facilitate debugging and inspection, the present invention is provided with a light indication system. When the liquid level electrode is immersed in the liquid, that is, the liquid surface is within the normal liquid level range, the green LED in the operating status indicator lights up, indicating that the safety circuit is closed and the heating device is operating normally; when the liquid level electrode floats out of the liquid, that is, the liquid level is below the set threshold, the red LED in the operating status indicator flashes, and the shutdown delay phase begins, and the safety circuit remains closed; after the shutdown delay time expires, the red LED in the operating status indicator remains on, the safety circuit is disconnected, and the heating device stops operating.

[0021] Furthermore, the test diagnostic button can be used to simulate an alarm state to check whether the liquid level switch is responding normally. The diagnostic indicator light is used to indicate equipment failure, with its flashing or steady state corresponding to different fault types, such as liquid level electrode failure, internal equipment failure, or wiring errors. Based on the state and flashing pattern of the diagnostic indicator light, combined with the troubleshooting process, the cause of the fault can be determined and the corresponding repair can be implemented.

[0022] The present utility model provides a liquid level switch with higher reliability, and its beneficial effects include: by adopting a dual-electrode structure and an anti-false alarm device, the present utility model effectively improves the accuracy and reliability of liquid level detection, avoids the occurrence of false alarms, and ensures the safe and stable operation of the equipment in complex environments. At the same time, the present utility model also has practical functions such as monitoring flush bypass time and flexible configuration of liquid level detection channels, further enhancing the intelligent level of liquid level control. The present utility model has a reasonable structural design, is easy to install, and is simple to operate. It can meet the high requirements of modern industry for liquid level control and has high practical value and application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the present invention, the following briefly introduces the drawings required for describing the embodiments. It is worth noting that the drawings in the following description are only schematic and do not limit the present invention.

[0024] Figure 1 A diagram of a housing not covering a light indicator panel provided in accordance with an embodiment of the present invention;

[0025] Figure 2 A top view of a cover light indicator panel provided in one embodiment of the present utility model;

[0026] Figure 3 A bottom view of an embodiment of the present invention is provided;

[0027] Figure 4 The present invention is a schematic diagram of a three-dimensional cross-sectional structure provided in one embodiment.

[0028] Figure numerals: 1. Housing; 2. Output board; 3. Control board; 4. Mounting lock; 5. Terminal block; 6. Light indicator panel; 7. Test and diagnostic button; 8. Operation status indicator light; 9. Diagnostic indicator light; 10. Upper cover; 11. Lower cover; 12. Connecting buckle; 13. Connecting hole; 14. Card slot; 15. Clamp; 16. Through slot; 17. Guide rail. DETAILED DESCRIPTION

[0029] Hereinafter, an embodiment of a liquid level switch with higher reliability of the present invention will be described with reference to the accompanying drawings. The embodiment described herein is a specific embodiment of the present invention, used to illustrate the concept of the present invention, and is illustrative and exemplary only, and should not be construed as limiting the embodiment and scope of the present invention.

[0030] It should be understood that when used in this specification and the appended claims, the terms "upper", "lower", "left", "right", "front", "back", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like to indicate directions or positional relationships are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a specific direction, be constructed and operate in a specific direction, and therefore should not be understood as limiting the present invention. At the same time, the term "comprising" indicates the presence of the described features, wholes, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, components and / or collections.

[0031] In order to simplify the drawings, some of the drawings only schematically represent and identify the most important parts of the utility model, and they do not represent the actual complete structure of the product.

[0032] It should be further understood that the terms "mounted," "connected," and "connected" should be interpreted broadly. For example, they can refer to fixed, removable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediary; and internal communication between two components. Those skilled in the art will understand the specific meanings of these terms in this utility model based on specific circumstances. Furthermore, the term "and / or" as used in this specification and the appended claims refers to any and all possible combinations of one or more of the associated listed items, including and including these combinations.

[0033] In order to have a clearer understanding of the technical features, purposes and effects of the present invention, the specific implementation of the preferred embodiment of the present invention is now described in detail with reference to the accompanying drawings.

[0034] like Figures 1 to 4 As shown in the figure, a liquid level switch with higher reliability proposed in an embodiment of the present utility model includes a housing 1; a circuit board is arranged in the housing 1, and the circuit board includes an output board 2 and a control board 3; two mounting locks 4 are provided at the bottom outside the housing 1, and a terminal group 5 and a light indicator panel 6 are provided at the top outside the housing 1, wherein the terminal group 5 includes terminal blocks numbered 1 to 30; the light indicator panel 6 includes two buttons 7 for diagnosis and testing, four operating status indicator lights 8 for notifying the operating status, and three diagnostic indicator lights 9 for diagnosis.

[0035] Terminals 1 to 15 in the terminal group 5 are electrically connected to the control board 3, and terminals 16 to 30 in the terminal group 5 are electrically connected to the output board 2. The output board 2 is electrically connected to the control board 3 via an electronic connecting line. The control board 3 is electrically connected to the light indicator panel 6. The light indicator panel 6 is electrically connected to the test diagnosis button 7, the operation status indicator light 8 and the diagnostic indicator light 9, which are used to check the function of the liquid level switch and display the operation status.

[0036] Terminals 1 through 5 and terminals 9 through 13 in terminal block 5 are electrically connected to the two liquid level electrodes, respectively, for receiving liquid level signals from the liquid level electrodes. Both the interface formed by terminals 1 through 5 and the interface formed by terminals 9 through 13 in terminal block 5 utilize a four-pin shielded interface design, effectively preventing electromagnetic interference and ensuring stable and reliable signal transmission.

[0037] Terminals 6 and 7 and terminals 14 and 15 in the terminal group 5 are electrically connected to the monitoring logic unit for monitoring special situations such as flushing bypass. When the liquid level electrode is installed on a lockable measuring container outside the boiler, the connecting pipeline needs to be flushed regularly to prevent dirt accumulation. During the flushing process, the liquid level switch cannot correctly detect the height of the liquid in the container and may mistakenly believe that the liquid level at this time is lower than the set threshold and issue an alarm through the operating status indicator 8. In order to avoid triggering unnecessary alarms during flushing, the utility model provides a 24V DC voltage signal to the liquid level switch through the monitoring logic unit, indicating that the liquid level switch is currently in the flushing state and no alarm is required. After receiving the flushing signal, the liquid level switch will bypass the liquid level electrode, disconnect the safety circuit, turn off the heating device, and start a 5-minute timer. After the timer expires, the liquid level switch will automatically re-enter the monitoring state to ensure that the system returns to normal operation.

[0038] Terminals 16 and 17 in the terminal group 5 are used to access the power supply voltage and work together with the power conversion module on the output board 2 to provide a stable power supply for the circuit, ensuring that the voltage and current fluctuations are within the specified range to meet the operating requirements of the control circuit.

[0039] Terminals 20, 21, and 29, 30 in terminal block 5 are used to output a 24V alarm signal with no delay, a maximum load of 100mA, and are activated only when the liquid level is detected to be below a set threshold. These terminals can be flexibly connected to alarm devices such as buzzers, thereby forming a delay-free alarm system and achieving more immediate safety alerts.

[0040] Terminals 23 and 24, as well as terminals 26 and 27, in terminal block 5 are electrically connected to the heater and control its operating status. When the liquid level is within the normal range, the two output contacts of the liquid level switch close, and the heater continues heating. When the liquid level falls below a set threshold, the two output contacts of the liquid level switch disconnect the heater's safety circuit, and the heater stops heating. The heater shutoff is interlocked in the external safety circuit and will not be re-unlocked until the liquid level returns to the normal range.

[0041] Specifically, the shell 1 includes an upper cover body 10 and a lower cover body 11. The connection between the upper cover body 10 and the lower cover body 11 is of the same size. The lower cover body 11 is provided with a connecting buckle 12, and the upper cover body 10 is provided with a connecting hole 13. The connecting buckle 12 and the connecting hole 13 are plugged into each other.

[0042] Specifically, such as Figure 4As shown, the left and right side walls inside the shell 1 are provided with card slots 14, and the bottom is provided with a clamping block 15. The card slots 14 and the clamping block 15 are fitted with the circuit board to fix the output board 2 and the control board 3; the top of the upper cover 10 is provided with a through slot 16, and the light indicator panel 6 is electrically connected to the control board 3 through the through slot 16.

[0043] Specifically, the bottom of the housing 1 is provided with a TH 35-type guide rail 17, which is arranged parallel to the circuit board inside the housing 1. During installation, the guide rail 17 on the bottom of the housing 1 needs to be precisely aligned with the pre-installed track inside the installation facility to ensure that the two are completely aligned. Then, the installation lock 4 on the bottom of the housing 1 is snapped into the guide rail 17 toward the guide rail to achieve a stable connection between the housing 1 and the installation facility.

[0044] Preferably, in turbulent environments such as sea voyages, liquid level fluctuations can lead to inaccurate liquid level measurement data. When the liquid sloshes, the level switch may incorrectly determine the remaining liquid amount, triggering an alarm, even though the actual liquid volume is still within a safe range. Therefore, based on extensive experimental data and targeting complex environments such as sea voyages, the present invention equips the control panel with a false alarm prevention function that effectively identifies and filters transient fluctuations in liquid level measurement, ensuring accurate measurement results.

[0045] Specifically, the present invention draws a trend graph of liquid level changes by deeply analyzing the dynamic characteristics of liquid level changes. After statistical analysis of the trend graph, the present invention proposes an anti-false alarm algorithm. The control panel can activate the shutdown delay mechanism when the liquid level is lower than the set threshold, rather than immediately alarming. During the shutdown delay period, the control panel will continue to monitor whether the liquid level has rebounded to determine whether the liquid level is continuously declining or temporarily declining. If the liquid level rebounds during the shutdown delay period, the alarm preparation is canceled; if the liquid level continues to be lower than the minimum liquid level, the alarm is eventually triggered. The utility model avoids false alarms caused by liquid shaking, can more accurately measure the position of the liquid surface, and improves the safety and stability of liquid level monitoring in complex environments.

[0046] Preferably, the present invention uses a dual-electrode method to detect liquid level, with one electrode serving as a minimum liquid level alarm electrode and the other serving as an auxiliary electrode. When the liquid level falls below the minimum liquid level, the minimum liquid level alarm electrode triggers an alarm signal, and the control board shuts down the safety circuit of the heating device after the shutdown delay expires, preventing damage to the device due to water shortage, thereby effectively improving the accuracy and reliability of liquid level detection.

[0047] Preferably, the control board 3 is provided with two coding switches, corresponding to the input signal channels of the two liquid level electrodes respectively. By operating the coding switches, it is possible to independently select whether to enable the input signal of the corresponding liquid level electrode, thereby flexibly configuring the required liquid level detection channel.

[0048] Preferably, in order to monitor the liquid level in real time and facilitate debugging and inspection, the utility model is provided with a light indication system. After the power is connected, the operating status indicator light 8 and the diagnostic indicator light 9 will all light up briefly, and then enter the normal operating state. The operating status indicator light 8 will display according to the immersion degree of the liquid level electrode. When the liquid level electrode is immersed in the liquid, that is, the liquid surface is in the normal liquid level range, the green LED light in the operating status indicator light 8 lights up, indicating that the safety circuit is closed and the heating device is operating normally; when the liquid level electrode floats out of the liquid, that is, the liquid level is lower than the set threshold, the red LED light in the operating status indicator light 8 flashes, entering the shutdown delay stage, and the safety circuit remains closed; after the shutdown delay time ends, the red LED light in the operating status indicator light 8 remains on, the safety circuit is disconnected, and the heating device stops running.

[0049] Furthermore, the test diagnostic button 7 can be used to simulate an alarm state to check whether the liquid level switch is responding normally. The diagnostic indicator light 9 is used to indicate equipment failure. Its flashing or steady state corresponds to different fault types, such as liquid level electrode failure, internal equipment failure, or wiring errors. Based on the state and flashing pattern of the diagnostic indicator light 9, combined with the troubleshooting process, the cause of the fault can be determined and the corresponding repair can be performed.

[0050] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A liquid level switch with higher reliability, characterized by: The invention comprises a housing (1), wherein the housing (1) comprises an upper cover (10) and a lower cover (11); a circuit board is arranged inside the housing (1), and the circuit board comprises an output board (2) and a control board (3); two mounting locks (4) are arranged on the bottom outside the housing (1); a wiring terminal group (5) and a light indication panel (6) are arranged on the top outside the housing (1); the wiring terminal group (5) comprises wiring terminals numbered 1 to 30; the light indication panel (6) comprises two buttons (7) for diagnosis and testing, four operating status indicator lights (8) for notifying the operating status, and three diagnostic indicator lights (9) for diagnosis; The first to 15th wiring terminals in the wiring terminal group (5) are electrically connected to the control board (3), the 16th to 30th wiring terminals in the wiring terminal group (5) are electrically connected to the output board (2), the output board (2) is electrically connected to the control board (3) via an electronic connection line, the control board (3) is electrically connected to the light indicator panel (6), and the light indicator panel (6) is electrically connected to the test diagnosis button (7), the operation status indicator light (8) and the diagnosis indicator light (9), for checking the function of the liquid level switch and displaying the operation status; The No. 1 to No. 5 wiring terminals and the No. 9 to No. 13 wiring terminals in the wiring terminal group (5) are electrically connected to the two liquid level electrodes respectively. The interface composed of the No. 1 to No. 5 wiring terminals in the wiring terminal group (5) and the interface composed of the No. 9 to No. 13 wiring terminals in the wiring terminal group (5) both adopt a four-pin shielded interface design; the No. 6 and No. 7 wiring terminals and the No. 14 and No. 15 wiring terminals in the wiring terminal group (5) are electrically connected to the monitoring logic unit; the No. 16 and No. 17 wiring terminals in the wiring terminal group (5) are used for The power supply voltage is connected and works in conjunction with the power conversion module on the output board (2) to ensure that the fluctuation of voltage and current is within the specified range; the No. 20 and No. 21 terminals and the No. 29 and No. 30 terminals in the terminal group (5) are used to output a 24V alarm signal without delay, with a maximum load of 100mA, and the output signal is activated only when the liquid level is detected to be lower than the set threshold; the No. 23 and No. 24 terminals and the No. 26 and No. 27 terminals in the terminal group (5) are electrically connected to the heating device to control the working state of the heating device.

2. A liquid level switch with higher reliability according to claim 1, characterized in that: The connection between the upper cover (10) and the lower cover (11) is of the same size, the lower cover (11) is provided with a connection buckle (12), the upper cover (10) is provided with a connection hole (13), and the connection buckle (12) and the connection hole (13) are plugged into and matched with each other.

3. A liquid level switch with higher reliability according to claim 1, characterized in that: The left and right side walls inside the housing (1) are provided with card slots (14), and the bottom is provided with a clamping block (15). The card slots (14) and the clamping block (15) are fitted with the circuit board and are used to fix the output board (2) and the control board (3); the top of the upper cover (10) is provided with a through slot (16), and the light indication panel (6) is electrically connected to the control board (3) through the through slot (16).

4. A liquid level switch with higher reliability according to claim 1, characterized in that: A TH 35 type guide rail (17) is provided at the bottom of the housing (1), and the TH 35 type guide rail (17) is arranged parallel to the circuit board inside the housing (1).

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