capacitance level gauge

Abstract

The utility model discloses a kind of capacitive level gauges, including shell, insulating sleeve, machine core component and electrode, machine core component is installed in shell, one end of electrode is fixedly installed with machine core component, the other end extends to the inside of insulating sleeve, fixed part is formed on electrode along radial extension, and the first end surface of insulating sleeve extending to fixed part between the inner wall of shell and the first end surface and the inner wall of shell of fixed part abut.Between the first end surface of the fixed part of the utility model's capacitive level gauge and the inner wall of shell, and the first end surface and the inner wall of shell of fixed part abut, so as to realize the effect of sealing machine core component inside shell, so as to save installation space and sealing space, the minimum can be guaranteed to measure complete condition to whole machine size.

Description

Technical Field

[0001] This utility model belongs to the field of intelligent sensor technology, specifically relating to a capacitive level gauge. Background Technology

[0002] A capacitive level gauge is a device that uses capacitance measurement technology to detect the level of materials in both contact and non-contact modes. It can measure both solid and liquid media and is not overly dependent on physical changes in the density, viscosity, or color of the medium. Due to its unique structure and operating principle, it is widely used in industrial production processes for measuring the level of materials.

[0003] The principle of a capacitive level gauge: It measures the level based on the principle of capacitance change. A capacitive sensor typically consists of two parallel metal plates forming a capacitor, or it has one electrode with a capacitor formed between the electrode and the container wall. When the measured medium comes into contact with the sensor, the capacitance changes. By detecting and calculating this change in capacitance, real-time information on the level height can be obtained, allowing for corresponding level height control.

[0004] Measuring the actual height of ethylene glycol / propylene glycol / aqueous solutions using capacitive level gauges within a liquid-cooled temperature control system requires meeting a range of special operating conditions (including EMC conducted interference, radiated interference, REACH compliance, flame retardancy, IP67 rating, humid and hot environments, and high salt spray). Existing products, in order to meet these conditions, add structural components to the internal circuitry and external structure, resulting in excessively large overall dimensions and causing dimensional interference within the system. Currently available compact capacitive level gauges often cannot meet the demands of these complex and special applications under conditions such as high humidity and heat, EMC conducted interference, and radiated interference.

[0005] The information disclosed in this background section is intended only to enhance the understanding of the overall background of this utility model and should not be construed as an admission or in any way implying that the information constitutes prior art known to those skilled in the art. Utility Model Content

[0006] The purpose of this invention is to provide a capacitive level gauge that can ensure sealing while reducing the overall size of the device.

[0007] To achieve the above objectives, the technical solution provided by a specific embodiment of this utility model is as follows:

[0008] A capacitive level gauge includes a housing, an insulating sleeve, a mechanism assembly, and an electrode. The mechanism assembly is installed inside the housing. One end of the electrode is fixedly installed to the mechanism assembly, and the other end extends into the interior of the insulating sleeve. A fixing portion extends radially on the electrode. The insulating sleeve extends between the first end face of the fixing portion and the inner wall of the housing and abuts against the first end face of the fixing portion and the inner wall of the housing.

[0009] In one or more embodiments of the present invention, the capacitance level gauge further includes a connection terminal, one end of which is fixedly installed with the mechanism assembly, and the other end of which is plugged into and fixed with the electrode.

[0010] In one or more embodiments of this utility model, the movement assembly includes a first circuit board and a second circuit board. The second circuit board is disposed on one side of the first circuit board, and the electrode is disposed on the other side of the first circuit board and fixedly installed thereon. A sampling module is disposed on the first circuit board, and the sampling module is connected to the electrode to sample the capacitance and generate a sampling signal. A power module and a control module are disposed on the second circuit board. The power module is connected to the sampling module and the control module to generate a power supply voltage, and the control module is connected to the sampling module to receive and transmit the sampling signal.

[0011] In one or more embodiments of the present invention, the movement assembly further includes a shielding ring, the shielding ring being in electrical contact with the housing, and the first circuit board and the second circuit board being disposed inside the shielding ring.

[0012] In one or more embodiments of this utility model, a first grounding point is provided on the edge of the first circuit board, and a capacitor is also provided on the first circuit board. The first grounding point is connected to a first end of the capacitor, and a second end of the capacitor is electrically connected to the shielding ring.

[0013] In one or more embodiments of this utility model, three first grounding points are provided, and the three first grounding points form an equilateral triangle.

[0014] In one or more embodiments of this utility model, a second grounding point is provided on the edge of the second circuit board, and the second grounding point is electrically connected to the shielding ring.

[0015] In one or more embodiments of this utility model, three second grounding points are provided, and the three second grounding points form an equilateral triangle.

[0016] In one or more embodiments of this utility model, the first circuit board and the second circuit board are connected by an FPC flexible flat cable.

[0017] In one or more embodiments of the present invention, the capacitive level gauge further includes a sealing ring disposed between the insulating sleeve and the inner wall of the housing.

[0018] Compared with existing technologies, the capacitive level gauge of this invention achieves the effect of sealing the core assembly inside the housing by forming a fixing part extending radially on the electrode and extending an insulating sleeve between the first end face of the fixing part and the inner wall of the housing, and abutting against the first end face of the fixing part and the inner wall of the housing. This saves installation space and sealing space, minimizing the overall size of the device while ensuring complete measurement. By using connecting terminals to fix the core assembly to the electrode, the device achieves a compact structure with no moving parts, avoiding vibration and shaking of the electronic core during product transportation. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of this 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 recorded in this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a schematic diagram of the structure of a capacitive level gauge in one embodiment of the present invention.

[0021] Figure 2 This is a cross-sectional schematic diagram of a capacitive level gauge in one embodiment of the present invention.

[0022] Figure 3 This is a system structure diagram of a capacitive level gauge in one embodiment of the present invention. Detailed Implementation

[0023] To enable those skilled in the art to better understand the technical solutions of this utility model, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of this utility model.

[0024] The terms "coupled," "connected," or "linked" in this specification include both direct and indirect connections. Indirect connections are those made through an intermediate medium, such as those made through an electrically conductive medium, which may have parasitic inductance or capacitance. Indirect connections may also include connections made through other active or passive devices to achieve the same or similar functional purpose, such as connections through switches, follower circuits, or other circuits or components. Furthermore, in this specification, terms such as "first" and "second" are primarily used to distinguish one technical feature from another, and do not necessarily require or imply any actual relationship, quantity, or order between these technical features.

[0025] In the detailed description of this specification, reference is made to the accompanying drawings, which form a part thereof, wherein like reference numerals always denote like parts, and wherein exemplary embodiments are shown by way of example that may be implemented. It should be understood that other embodiments may be utilized, and structural or logical changes may be made, without departing from the scope of this application. Therefore, the following detailed description should not be considered limiting.

[0026] The various operations in the specification may be described sequentially as multiple discrete actions or operations in a manner most conducive to understanding the claimed subject matter. However, the order of description should not be construed as implying that these operations must be sequentially related. Specifically, these operations may not be performed in the order presented. The described operations may be performed in a different order than in the described embodiments. Various additional operations may be performed in additional embodiments and / or the described operations may be omitted.

[0027] For the purposes of this application, the phrase "A and / or B" means (A), (B), or (A and B). For the purposes of this application, the phrase "A, B and / or C" means (A), (B), (C), (A and B), (A and C), (B and C), or (A, B and C).

[0028] Various components and devices may be mentioned or shown in the singular form herein, but only for the convenience of discussion, and any element mentioned in the singular form may include multiple such elements as taught herein.

[0029] The description uses the phrases "in one embodiment," "in other embodiments," or "in some embodiments," each of which may refer to one or more of the same or different embodiments. Furthermore, the terms "comprising," "including," "having," etc., used in relation to embodiments of this application are synonymous.

[0030] Combination Figure 1 and Figure 2 As shown, a capacitive level gauge in one embodiment of the present invention includes a housing 10, an insulating sleeve 20, a mechanism assembly 30, an electrode 40, and a sealing ring 50.

[0031] The mechanism assembly 30 is installed inside the housing 10. One end of the electrode 40 is fixedly installed with the mechanism assembly 30, and the other end extends into the interior of the insulating sleeve 20. A fixing part 41 is formed on the electrode 40 extending radially. The insulating sleeve 20 extends to the space between the first end face of the fixing part 41 and the inner wall of the housing 10 and abuts against the first end face of the fixing part 41 and the inner wall of the housing 10.

[0032] The sealing ring 50 is disposed between the insulating sleeve 20 and the inner wall of the housing 10 to form a double seal, which saves sealing space while ensuring the effectiveness of the seal.

[0033] In one embodiment, the capacitive level gauge further includes a connection terminal 60, one end of which is fixedly mounted to the mechanism assembly 30, and the other end of which is inserted and fixedly connected to the electrode 40. Exemplarily, the connection terminal 60 is inserted into and fixed from the end of the electrode 40.

[0034] In one embodiment, the housing 10 includes a mechanism housing 11 and a process tip 12. The mechanism housing 11 and the process tip 12 are connected by threads. The mechanism assembly 30 is disposed inside the mechanism housing 11. An electrode 40 extends from inside the process tip 12 into an insulating sleeve 20. A fixing portion 41 is disposed on the portion of the electrode 40 located inside the process tip 12. The insulating sleeve 20 extends between the first end face of the fixing portion 41 and the inner wall of the process tip 12, and abuts against the first end face of the fixing portion 41 and the inner wall of the process tip 12.

[0035] By tightening the housing 11 and the process head 12, the top of the insulating sleeve 20 will be pressed between the first end face of the fixing part 41 and the inner wall of the process head 12, forming a good seal. It should be noted that for a complete display, Figure 2 The diagram shown is of the insulating sleeve 20 not being fully compressed. It can be understood that as long as the electrode 40 is pressed down further, the fixing part 41 can compress the insulating sleeve 20 to abut against the inner wall of the process tooth 12.

[0036] For example, the first end face of the fixing part 41 is its bottom surface, and the bottom surface of the fixing part 41 forms a slope that is adapted to the inner wall of the process tooth tip 12. The slope is inclined from bottom to top in the direction outward from the center of the electrode 40. It can be understood that the bottom of the fixing part 41 can also be a plane, a curved surface, a downward slope, etc.

[0037] In one embodiment, the capacitance level gauge further includes a clamping member 71, an insulating pad 72, and an insulating bushing 73.

[0038] The insulating gasket 72 is sleeved on the electrode 40, with one end touching the second end face of the fixing part 41. The clamping member 71 is disposed between the process tooth 12 and the electrode 40 and is fixedly installed on the process tooth 12. The clamping member 71 abuts against the other end of the insulating gasket 72. The insulating gasket 72 can form an insulating barrier between the electrode 40 and the process tooth 12, and between the clamping member 71 and the fixing part 41 of the electrode 40. An insulating bushing 73 is disposed between the clamping member 71 and the electrode 40, and the insulating bushing 73 is used to insulate the clamping member 71 from the electrode 40.

[0039] Specifically, the bottom end of the insulating gasket 72 abuts against the top surface of the fixing part 41, and the bottom end of the clamping member 71 abuts against the top end of the insulating gasket 72. During installation, the clamping member 71 can be pressed down to tighten the insulating gasket 72 and fix it to the process tooth 12, so that the insulating gasket 72 can further press the electrode 40 and the process tooth 12 synchronously, thereby ensuring the sealing of the insulating sleeve.

[0040] The outer side of the clamping member 71 and the inner side of the process tooth head 12 can be respectively provided with matching external threads and internal threads. The two are connected by threads. The clamping member 71 and the process tooth head 12 can also be installed by welding, gluing, snap-fitting or other methods.

[0041] In one embodiment, the clamping member 71 and the insulating sleeve 73 are fitted onto the electrode 40. The bottom of the insulating sleeve 73 may also extend radially to form an abutment portion, the bottom of which abuts against the electrode 40, and the top of which abuts against the clamping member 71. The clamping member 71 can also clamp the electrode 40 via the insulating sleeve 73 while clamping the electrode 40 via the insulating gasket 72.

[0042] In one embodiment, the outer casing 11 of the mechanism and the process tooth 12 are made of metal, and the insulating sleeve 20 is made of plastic materials such as PFA, PP, and PTFE, preferably PFA, which has good flame retardancy and corrosion resistance.

[0043] Combination Figure 2 and Figure 3 As shown, the movement assembly 30 includes a first circuit board 31, a second circuit board 32, and a shielding ring 33. The second circuit board 32 is disposed on one side of the first circuit board 31, and the connecting terminal 60 is disposed on the other side of the first circuit board 31 and fixedly installed thereon. The shielding ring 33 is in electrical contact with the movement housing 11, and both the first circuit board 31 and the second circuit board 32 are disposed inside the shielding ring 33.

[0044] The first circuit board 31 is provided with a sampling module 311, which is connected to the connection terminal 60 to sample the capacitor and generate a sampling signal. The second circuit board 32 is provided with a power module 322 and a control module 321. The power module 322 is connected to the sampling module 311 and the control module 321 to generate a power supply voltage. The control module 321 is connected to the sampling module 311 to receive and send the sampling signal to the outside.

[0045] For example, the sampling module 311 may include a capacitor sampling unit, an operational amplifier unit, a filtering unit, and an analog-to-digital converter unit. The capacitor sampling unit is connected to the electrode 40 to sample the capacitor and generate a sampling signal. The operational amplifier unit is connected to the capacitor sampling unit to amplify the sampling signal. The filtering unit is connected to the operational amplifier unit to filter the amplified sampling signal. The analog-to-digital converter unit is connected to the filtering unit and the control module 321 to perform analog-to-digital conversion on the filtered sampling signal and send the converted sampling signal to the control module 321.

[0046] The control module 321 may include an MCU chip. After receiving the sampling signal, the MCU chip can calculate the mathematical relationship between the collected capacitance value and the corresponding liquid level height using effective algorithms and formulas. Then, in conjunction with peripheral circuitry, it converts the actual level height into a 4-20mA analog signal, 0-5V, 0-10V, RS485 signal output. Preferably, it converts it into a 4-20mA analog signal for output. In one embodiment, the control module 321 can also be connected to a capacitor sampling unit to control the capacitor sampling unit to perform sampling.

[0047] The power supply module 322 may include an LDO circuit and a voltage conversion chip to convert the external input voltage (such as 9-13V DC) into the power supply voltage required by the control module 321 and the sampling module 311. The power supply module 322 generally contains high-power devices. By placing these devices on the second circuit board 32, heat dissipation can be facilitated, and they can be isolated from the sampling module 311 to avoid the influence of power fluctuations on signal acquisition.

[0048] It is understandable that the capacitor sampling unit, operational amplifier unit, filtering unit, analog-to-digital converter unit, LDO circuit, voltage conversion chip and control module 321 can all be implemented using various modules, chips or circuits in the prior art.

[0049] Preferably, the first circuit board 31 and the second circuit board 32 are connected by an FPC flexible flat cable, which can avoid the influence of long plug pins and effectively avoid radiation interference.

[0050] like Figure 3As shown, a first grounding point D1 is provided on the edge of the first circuit board 31, and a capacitor C is also provided on the first circuit board 31. The first grounding point D1 is connected to the first end of the capacitor C, and the second end of the capacitor C is electrically connected to the shielding ring 33.

[0051] In one embodiment, three first grounding points D1 are provided, and the three first grounding points D1 form an equilateral triangle.

[0052] The edge of the second circuit board 32 is provided with a second grounding point D2, which is electrically connected to the shielding ring 33.

[0053] In one embodiment, three second grounding points D2 are provided, and the three second grounding points D2 form an equilateral triangle.

[0054] In one embodiment, both the first circuit board 31 and the second circuit board 32 are circular. First grounding points D1 are evenly distributed at 120° intervals around the circumference of the first circuit board 31, and second grounding points D2 are evenly distributed at 120° intervals around the circumference of the second circuit board 32. The second grounding points D2 can be directly soldered to the shielding ring 33, thereby providing a fixed support for the second circuit board 32.

[0055] The ground wire on the first circuit board is connected to the first grounding point D1, and the ground wire on the second circuit board is connected to the second grounding point D2. The ground wire on the second circuit board can be connected to the ground wire on the first circuit board via an FPC flexible cable to achieve ground potential balance between the two circuit boards.

[0056] By using three-point equivalent grounding, signal transmission interference is avoided, thus improving the EMI resistance of the capacitance level gauge.

[0057] By setting a first grounding point D1 and a second grounding point D2, the ground wires on the first circuit board 31 and the second circuit board 32 are directly or indirectly connected to the shielding ring 33. At the same time, the shielding ring 33 is electrically connected to the mechanism housing 11 and the process tooth 12. In actual operation, the mechanism housing 11 and the process tooth 12 are often connected to the ground voltage through installation. This design can maintain the circuit effectively grounded and avoid conducted interference, while also applying the electrical signal of the capacitance level gauge to the process tooth 12, thereby playing an auxiliary measurement role.

[0058] Compared with existing technologies, the capacitive level gauge of this invention, through its sealed end face design, allows the core assembly 30 to be sealed inside the housing 10, saving installation and sealing space. This minimizes the overall size of the device while ensuring complete measurement, and maintains sealing integrity for extended periods even within a liquid-cooled unit, preventing the risk of failure due to leakage. The core assembly 30 is fixedly mounted to the electrode 40, and the electronic components of the entire device have no moving parts. This reduces the space required compared to conventional products and also prevents vibration and core movement during transport.

[0059] The 30-part core assembly incorporates multiple anti-interference designs to effectively eliminate internal and external electromagnetic interference. Unlike conventional DC 24V power supplies, this electronic design can utilize a 9-13VDC power supply, coupled with a two-wire 4-20mA output for even lower power consumption. It is suitable for long-term operation inside liquid-cooled units in data centers and computing centers to measure the actual height of ethylene glycol / propylene glycol / water solutions.

[0060] It will be apparent to those skilled in the art that this invention is not limited to the details of the exemplary embodiments described above, and that it can be implemented in other specific forms without departing from the spirit or essential characteristics of this invention. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of this invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within this invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0061] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A capacitive level gauge, characterized in that, The device includes a housing, an insulating sleeve, a movement assembly, and an electrode. The movement assembly is installed inside the housing. One end of the electrode is fixedly installed to the movement assembly, and the other end extends into the interior of the insulating sleeve. A fixing portion extends radially from the electrode. The insulating sleeve extends between the first end face of the fixing portion and the inner wall of the housing and abuts against the first end face of the fixing portion and the inner wall of the housing.

2. The capacitance position meter according to claim 1, characterized in that The capacitance level gauge also includes a connection terminal, one end of which is fixedly installed with the mechanism assembly, and the other end of which is plugged into and fixed with the electrode.

3. The capacitance point level gauge according to claim 1, characterized in that, The mechanism assembly includes a first circuit board and a second circuit board. The second circuit board is disposed on one side of the first circuit board, and the electrode is disposed on the other side of the first circuit board and fixedly installed thereon. A sampling module is disposed on the first circuit board, and the sampling module is connected to the electrode to sample the capacitance and generate a sampling signal. A power module and a control module are disposed on the second circuit board. The power module is connected to the sampling module and the control module to generate a power supply voltage, and the control module is connected to the sampling module to receive and transmit the sampling signal.

4. The capacitive level gauge according to claim 3, characterized in that, The movement assembly also includes a shielding ring, which is in electrical contact with the housing, and the first circuit board and the second circuit board are disposed inside the shielding ring.

5. The capacitive level gauge according to claim 4, characterized in that, The first circuit board has a first grounding point on its edge. A capacitor is also provided on the first circuit board. The first grounding point is connected to the first end of the capacitor, and the second end of the capacitor is electrically connected to the shielding ring.

6. The capacitive level gauge according to claim 5, characterized in that, There are three first grounding points, which form an equilateral triangle.

7. The capacitive level gauge according to claim 4, characterized in that, The edge of the second circuit board is provided with a second grounding point, which is electrically connected to the shielding ring.

8. The capacitive level gauge according to claim 7, characterized in that, There are three second grounding points, which form an equilateral triangle.

9. The capacitive level gauge according to claim 3, characterized in that, The first circuit board and the second circuit board are connected by an FPC flexible flat cable.

10. The capacitive level gauge according to claim 1, characterized in that, The capacitive level gauge also includes a sealing ring, which is disposed between the insulating sleeve and the inner wall of the housing.

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