Ultrasonic gas meter

Abstract

The invention provides an ultrasonic gas meter, and relates to the technical field of metering equipment. The ultrasonic gas meter comprises a controller which comprises a shell and a main control board, and the main control board is arranged in the shell; the base meter is connected to the rear side of the controller; the base meter comprises a meter shell and a metering module, the metering module is arranged in the meter shell, and the grounding end of the metering module is electrically connected with the reference ground end of the main control board; and the filtering circuit board is electrically connected between the reference ground end of the main control board and the meter shell. According to the ultrasonic gas meter, the interference signal can be transmitted to the meter shell, the influence of the interference signal on the metering module is eliminated, the stability of the metering module is enhanced, and the metering precision of the ultrasonic gas meter is improved.

Description

Technical Field

[0001] The present application relates to the technical field of metering equipment, and in particular to an ultrasonic gas meter. Background Art

[0002] With the improvement of living standards, more and more residential houses and commercial places use gas as a daily fuel. Places where gas is used are usually equipped with gas meters to measure the gas used.

[0003] As an electronic flow meter, the core principle of the ultrasonic gas meter is to detect the uplink and downlink flight transmission waveforms of the ultrasonic transducer, calculate the flight time difference, and then infer the gas flow based on the changes in the flight time difference caused by different media.

[0004] However, as a core component, the ultrasonic transducer generates weak signal characteristics and is easily affected by electromagnetic interference, which can lead to inaccurate measurement and even no flow measurement in severe cases. Summary of the Invention

[0005] The present application provides an ultrasonic gas meter, which can eliminate electromagnetic radiation field interference, enhance the stability of the metering module, and improve the metering accuracy of the ultrasonic gas meter.

[0006] The present application provides an ultrasonic gas meter, comprising:

[0007] The controller comprises a housing and a main control board, wherein the main control board is arranged in the housing;

[0008] The base meter is connected to the rear side of the controller; the base meter includes a meter case and a metering module, the metering module is arranged in the meter case, and the ground terminal of the metering module is electrically connected to the reference ground terminal of the main control board;

[0009] The filter circuit board is electrically connected between the reference ground terminal of the main control board and the case.

[0010] In one possible implementation, the filter circuit board includes a reference ground portion, a filter circuit, and a protection ground portion, wherein the reference ground portion and the protection ground portion are electrically isolated and connected via the filter circuit;

[0011] The reference ground part is electrically connected to the reference ground terminal of the main control board, and the protective ground part is electrically connected to the case.

[0012] In a possible implementation, the main control board further includes a protective ground terminal, the protective ground terminal of the main control board is electrically isolated from the reference ground terminal of the main control board, and the protective ground terminal of the main control board is electrically connected to the case.

[0013] In a possible implementation, the filter circuit board is disposed between the controller and the base meter.

[0014] In a possible implementation, the filter circuit board is connected to the main control board via a connecting wire, and the filter circuit board is connected to the watch case via a connecting wire.

[0015] In one possible embodiment, the housing of the controller includes a connected controller front housing and a connected controller rear housing, the housing of the base meter includes a connected base meter front housing and a connected base meter rear housing, and the controller rear housing is connected to the base meter front housing;

[0016] The filter circuit board is arranged between the rear shell of the controller and the front shell of the base meter, and the filter circuit board is electrically connected to the front shell of the base meter.

[0017] In a possible implementation, the filter circuit board is disposed in a watch case of the base watch.

[0018] In a possible implementation, the filter circuit board is electrically connected to the main control board via contact pins.

[0019] In a possible implementation, the base table further includes:

[0020] The shielding cover is arranged in the case of the base meter and is electrically insulated from the case, and the shielding cover is arranged on the periphery of the metering module.

[0021] In a possible embodiment, the base watch includes a base watch front shell and a base watch rear shell connected to each other, and the shielding cover includes a left cover body and a right cover body connected to each other;

[0022] The docking direction of the base watch front shell and the base watch rear shell is a first direction, the docking direction of the left cover body and the right cover body is a second direction, and the first direction and the second direction have an angle.

[0023] The ultrasonic gas meter provided in the present application includes a controller, a base meter, and a filter circuit board. The controller includes a housing and a main control board arranged in the housing. The base meter is connected to the rear side of the controller. The base meter includes a case and a metering module installed in the case. The filter circuit board is electrically connected between the reference ground terminal of the main control board and the case of the base meter. The ground terminal of the metering module is electrically connected to the reference ground terminal of the main control circuit board. By connecting the filter circuit board between the reference ground terminal of the main control board and the case, the interference signal generated by the main control board and the connecting line connected thereto can be transmitted to the case through a limited flow loop, so as to eliminate the influence of the interference signal on the metering module, enhance the stability of the metering module, and improve the metering accuracy of the metering module. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] To more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present application. Those skilled in the art can also derive other drawings based on these drawings without inventive effort.

[0025] Figure 1 A schematic structural diagram of an ultrasonic gas meter according to an embodiment of the present application from one perspective;

[0026] Figure 2 for Figure 1 A schematic structural diagram of an ultrasonic gas meter from another perspective;

[0027] Figure 3 for Figure 1 Exploded structure diagram of ultrasonic gas meter in;

[0028] Figure 4 A schematic diagram of the electrical connection of an ultrasonic gas meter provided in an embodiment of the present application;

[0029] Figure 5 A cross-sectional view of another base table provided in an embodiment of the present application.

[0030] Description of reference numerals:

[0031] 10-Ultrasonic gas meter;

[0032] 100-controller;

[0033] 110-housing; 120-main control board;

[0034] 111-controller front shell; 112-controller rear shell; 121-reference ground terminal; 122-protective ground terminal;

[0035] 1111-display screen; 1112-button;

[0036] 200-base table;

[0037] 210-case; 220-metering module; 230-shielding cover; 240-connecting wire; 250-contact pin;

[0038] 211 - base meter front shell; 212 - base meter rear shell; 221 - module circuit board; 231 - left cover; 232 - right cover;

[0039] 2101-air inlet; 2102-air outlet; 2211-ground terminal;

[0040] 300- filter circuit board;

[0041] 310 - reference ground part; 320 - filter circuit; 330 - protection ground part. DETAILED DESCRIPTION

[0042] As mentioned in the background, the ultrasonic transducer, the core component of an ultrasonic gas meter, generates weak signals that are susceptible to electromagnetic interference, which can lead to inaccurate measurements and, in severe cases, even zero flow.

[0043] To improve the anti-interference performance of ultrasonic gas meters, the following solutions are commonly used in related technologies. Solution 1: Use a metal shielding structure to provide electromagnetic protection for the metering module. Solution 2: Analyze the metering module's detection data and filter it using software algorithms. Solution 3: Wrap the metering module's circuit board with a metal layer or add a metal baffle for electromagnetic shielding.

[0044] However, all of the above-mentioned solutions have some defects. The defect of Solution 1: Due to the limitation of the flow channel opening of the metering module, it is impossible to completely shield the metering module, and the intensity of electromagnetic interference received by the meter at different angles is different. In addition, the circuit board in the controller of the meter and the lead part connected to the base meter cannot effectively protect against electromagnetic interference. The defect of Solution 2: Due to the randomness and disorder of electromagnetic interference, the filtering algorithm cannot guarantee that while correctly processing the normal operating flow data, it can also correctly identify the interfered data and completely filter it out. The defect of Solution 3: If the circuit board is wrapped or shielded with metal, while shielding the electromagnetic interference, it will also shield the normal communication signal of the meter, resulting in the failure of the communication function, so this method is not practical.

[0045] In view of this, an embodiment of the present application provides an ultrasonic gas meter, which includes a controller, a base meter, and a filter circuit board. The controller includes a housing and a main control board arranged in the housing. The base meter is connected to the rear side of the controller. The base meter includes a case and a metering module installed in the case. The filter circuit board is electrically connected between the reference ground terminal of the main control board and the case of the base meter. The ground terminal of the metering module is electrically connected to the reference ground terminal of the main control circuit board. By connecting the filter circuit board between the reference ground terminal of the main control board and the case, the interference signal generated on the main control board and the connecting line connected thereto can be transmitted to the case through a limited flow loop to eliminate the influence of the interference signal on the metering module, enhance the stability of the metering module, and improve the metering accuracy of the metering module.

[0046] To make the purpose, technical solutions, and advantages of the embodiments of this application more clear, the technical solutions in the embodiments of this application will be clearly and completely described below in conjunction with the drawings in the embodiments of this application. Obviously, the described embodiments are part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0047] Figure 1 A schematic structural diagram of an ultrasonic gas meter from one perspective provided in an embodiment of the present application. Figure 2 for Figure 1 Another perspective of the ultrasonic gas meter structure diagram. Figure 1 and Figure 2 As shown, an embodiment of the present application provides an ultrasonic gas meter 10, which includes a controller 100 and a base meter 200. The controller 100 and the base meter 200 are connected to each other. The base meter 200 is used to measure the gas flow, and the controller 100 is used to control the operation of the base meter 200.

[0048] The controller 100 and base meter 200 can be docked horizontally, meaning they can be placed side by side. Furthermore, the base meter 200 can be connected to the rear of the controller 100. In other words, the controller 100 is placed in front of the base meter 200, with the side of the controller 100 facing away from the base meter 200 corresponding to the front of the ultrasonic gas meter 10. The side of the controller 100 facing away from the base meter 200 can be equipped with a display screen 1111, buttons 1112, and other components to facilitate human-computer interaction.

[0049] Figure 3 for Figure 1 The exploded structure diagram of the ultrasonic gas meter in . Figure 3 As shown, the controller 100 may include a housing 110 and a main control board 120. The housing 110 is the external structural component of the controller 100, and the main control board 120 is disposed within the housing 110. The main control board 120 is electrically connected to the base meter 200 and can control the operating status of the base meter 200. The housing 110 surrounds the main control board 120, fully enclosing it to provide waterproof and dustproof protection, ensuring the stability and reliability of its operation.

[0050] The base meter 200 includes a housing 210 and a metering module 220. The housing 210 is the external structural component of the base meter 200, and the metering module 220 is housed within the housing 210. The metering module 220 is used to measure gas flow and is electrically connected to the main control board 120 of the controller 100, enabling signal transmission between the two. The housing 210 encloses the metering module 220 to protect it and allow the base meter 200 to be assembled into a self-contained, integrated structure.

[0051] The housing 110 of the controller 100 and the housing 210 of the base meter 200 are connected to form the ultrasonic gas meter 10. For example, the housing 110 of the controller 100 and the housing 210 of the base meter 200 can be fastened together using fasteners such as screws and bolts. Alternatively, the housing 110 of the controller 100 and the housing 210 of the base meter 200 can be connected by snapping together using a snap-fit ​​structure such as a snap or slot. Alternatively, the housing 110 of the controller 100 and the housing 210 of the base meter 200 can be adhesively bonded.

[0052] The housing 110 of the controller 100 may include a front housing 111 and a rear housing 112. The front housing 111 and the rear housing 112 are joined horizontally front to back to form a housing cavity, within which the main control board 120 is disposed. The front housing 111 may be located on the side of the controller 100 facing away from the base meter 200, while the rear housing 112 faces the base meter 200 and is connected to the housing 210 of the base meter 200. Components such as the display screen 1111 and buttons 1112 may be disposed on the front housing 111.

[0053] Similar to the housing 110 of the controller 100, the housing 210 of the base meter 200 may also include a base front housing 211 and a base rear housing 212. The base front housing 211 and the base rear housing 212 are connected horizontally front to back to form a storage space, and the meter module 220 is disposed within this storage space. The base front housing 211 can face the controller 100 and is connected to the controller rear housing 112. The base rear housing 212 is located on the side of the base meter 200 facing away from the controller 100.

[0054] For example, a sealing ring (not shown in the figure) may be provided between the controller front shell 111 and the controller rear shell 112 to achieve a sealed connection between the controller front shell 111 and the controller rear shell 112, thereby ensuring the sealing of the housing 110 of the controller 100 and improving the waterproof and dustproof performance of the main control board 120 located in the housing 110. Similarly, a sealing ring (not shown in the figure) may also be provided between the base meter front shell 211 and the base meter rear shell 212 to achieve a sealed connection between the base meter front shell 211 and the base meter rear shell 212, thereby ensuring the airtightness of the base meter 200 and improving the measurement accuracy of the metering module 220.

[0055] In addition, in some embodiments, the housing 110 of the controller 100 may include only a controller front housing 111. The controller front housing 111 and the base meter front housing 211 of the base meter 200 together form a housing cavity to enclose the main control board 120. Similarly, the housing 210 of the base meter 200 may include only a base meter rear housing 212. The base meter rear housing 212 and the controller rear housing 112 of the controller 100 together form a housing cavity to enclose the aforementioned metering module 220, valves, rectifiers, and other components.

[0056] Continue to refer to Figure 3 As shown, the base meter 200 has a housing 210 provided with an air inlet 2101 and an air outlet 2102. Gas enters the housing 210 through the air inlet 2101 and exits the base meter 200 through the air outlet 2102. As the gas flows within the housing 210 of the base meter 200, the gas flow rate can be measured by a metering module 220 provided within the housing 210.

[0057] A valve (not shown) may also be provided within the housing 210 of the base meter 200. The valve may be connected to the air inlet 2101 on the housing 210 and is used to control the on / off flow of gas within the housing 210. A metering module 220 may be provided between the valve and the air outlet 2102 on the housing 210, with the metering module 220 and the air outlet 2102 being connected. When the valve is open, gas enters the housing 210 through the air inlet 2101, passes through the valve, and then enters the metering module 220, where the gas flow rate is measured. The gas then flows out through the air outlet 2102 on the housing 210.

[0058] In some embodiments, a rectifying element (not shown) may be disposed within the housing 210 of the base meter 200 and located between the valve and the metering module 220. Before the gas flows from the valve to the metering module 220, it undergoes rectification by the rectifying element, thereby improving the uniformity of the gas flow. This ensures a more balanced flow rate and pressure of the gas entering the metering module 220, thereby improving the metering accuracy of the metering module 220.

[0059] This embodiment does not limit the location of the air inlet 2101 and the air outlet 2102 on the watch case 210 of the base watch 200, and can be designed according to the installation space of the base watch front case 211 and the base watch rear case 212. For example, the air inlet 2101 and the air outlet 2102 can both be located on the base watch rear case 212 (e.g., Figure 3 ), or, the air inlet 2101 and the air outlet 2102 may both be arranged on the base watch front shell 211, or, one of the air inlet 2101 and the air outlet 2102 may be arranged on the base watch front shell 211 and the other may be arranged on the base watch rear shell 212.

[0060] For example, the air inlet 2101 and the air outlet 2102 can be arranged at the top of the case 210 of the base watch 200. Figure 3 As shown in the example, the air inlet 2101 and the air outlet 2102 are both provided at the top of the base meter rear case 212. The air inlet 2101 and the air outlet 2102 provided at the top of the meter case 210 can be close to both ends of the top of the meter case 210, respectively, so as to reserve a sufficient distance between the air inlet 2101 and the air outlet 2102 to ensure smooth flow of gas in the meter case 210.

[0061] In this case, the metering module 220 can extend along the height direction of the base watch 200, or in other words, the axial direction of the metering module 220 can be aligned with the height direction of the base watch 200. The metering module 220 can be open at both axial ends, with the bottom end of the metering module 220 serving as its inlet and the top end as its outlet. The top outlet of the metering module 220 is connected to the air outlet 2102 on the watch case 210.

[0062] Continue to refer to Figure 3 The base meter 200 also includes a shielding cover 230, which is disposed within the case 210 of the base meter 200 and covers the periphery of the meter module 220. Both the shielding cover 230 and the case 210 can be made of metal materials, and both can be made of corrosion-resistant metal materials, such as stainless steel, titanium alloy, or other metal materials. Alternatively, both can be formed by chrome or nickel plating on sheet metal surfaces. Furthermore, the shielding cover 230 and the case 210 are electrically insulated. In other words, a gap should exist between the shielding cover 230 and the case 210, so that the two do not contact each other.

[0063] With this arrangement, the case 210, an external structural component of the base meter 200 and made of metal, surrounds the outermost portion of the meter module 220, forming a metal shield for the meter module 220. Furthermore, the shielding cover 230, also made of metal and located around the periphery of the meter module 220, also forms a metal shield for the meter module 220. The case 210 and shielding cover 230 of the base meter 200 form a double-layer shielding structure for the meter module 220, providing comprehensive spatial protection for the meter module 220 and effectively eliminating electromagnetic interference from radiation fields.

[0064] The case 210 of the base meter 200, serving as the external structural component of the base meter 200, fully surrounds the metering module 220 located therein, providing comprehensive spatial protection for the metering module 220. The shielding cover 230, located around the periphery of the metering module 220, can be designed to surround and shield the metering module 220 as much as possible, leaving only the inlet of the metering module 220 exposed to allow smooth gas flow in and out of the module. This effectively shields the metering module 220, enhancing the dual protective effects of the case 210 and the shielding cover 230.

[0065] The shielding cover 230 can extend axially along the metering module 220. For example, if the metering module 220 extends along the height of the base meter 200, the shielding cover 230 can also extend along the height of the base meter 200. This allows the shielding cover 230 to better match the metering module 220, shielding the metering module 220 as much as possible and enhancing the shielding effect of the shielding cover 230 on the metering module 220. The shielding cover 230 and the case 210 of the base meter 200 cooperate to provide dual protection for the metering module 220, thereby enhancing the overall resistance of the base meter 200 to electromagnetic interference from radiated fields.

[0066] When the air inlet 2101 and air outlet 2102 of the base meter 200 are located at the top of the meter case 210, the metering module 220 has its inlet and outlet at its axial ends, and the outlet at the top of the metering module 220 is connected to the air outlet 2102 on the meter case 210, the shielding cover 230 can be designed as a cylindrical structure. The shielding cover 230 extends along the height direction of the base meter 200. The upper and lower ends of the shielding cover 230 are open to facilitate the shielding cover 230 to be installed outside the metering module 220. The inlet or outlet at the bottom of the metering module 220 is exposed outside the shielding cover 230, so that gas can smoothly enter and exit the metering module 220.

[0067] For example, the bottom end of the shielding cover 230 may extend below the bottom end of the metering module 220. In other words, the extension length of the shielding cover 230 may be greater than the extension length of the metering module 220, and the bottom end of the shielding cover 230 may extend beyond the bottom end of the metering module 220. In this way, the shielding cover 230 can completely cover the periphery of the metering module 220, which is equivalent to the shielding cover 230 fully surrounding the metering module 220, and the shielding cover 230 can effectively shield and protect the metering module 220.

[0068] Continue to refer to Figure 3 As an embodiment, the shielding cover 230 may include a left cover body 231 and a right cover body 232, which are connected to each other to form a cylindrical shielding cover 230. When installing the shielding cover 230, one of the left cover body 231 and the right cover body 232 may be first connected to the periphery of the metering module 220, and then the other may be connected thereto to assemble the entire shielding cover 230. This facilitates the placement of the shielding cover 230 outside the metering module 220, reduces the difficulty in manufacturing the shielding cover 230, and reduces the manufacturing cost of the shielding cover 230, thereby reducing the overall cost of the base meter 200.

[0069] In other embodiments, the shielding cover 230 may also be an integrated structure. In this case, the shielding cover 230 and the metering module 220 may be assembled together before the metering module 220 is installed in the case 210 of the base meter 200. The metering module 220 and the shielding cover 230 are then integrally installed in the case 210. The following description uses the example of a shielding cover 230 comprising a left cover body 231 and a right cover body 232 that are connected to each other.

[0070] For ease of explanation, in this embodiment, the mating direction of the base watch front case 211 and the base watch rear case 212 is defined as a first direction, and the mating direction of the left cover 231 and the right cover 232 of the shielding cover 230 is defined as a second direction. In this embodiment, an angle is formed between the first direction and the second direction. In other words, an angle is formed between the mating direction of the base watch front case 211 and the base watch rear case 212 and the mating direction of the left cover 231 and the right cover 232.

[0071] In this way, the seam between the front and rear housings 211 and 212 of the base watch is staggered with the seam between the left and right covers 231 and 232. The shielding cover 230 and the case 210 of the base watch 200 can fully enclose the metering module 220. Furthermore, there are no radially corresponding seams on the periphery of the metering module 220, which enhances the shielding effect of the shielding cover 230 and the base watch 200 on the metering module 220.

[0072] For example, the first direction in which the front case 211 and the rear case 212 of the base meter are joined can be perpendicular to the second direction in which the left cover 231 and the right cover 232 are joined. This maximizes the offset between the seam of the shielding cover 230 and the seam of the case 210, further enhancing the dual protection provided by the shielding cover 230 and the base meter 200 for the meter module 220. For example, if the first direction in which the front case 211 and the rear case 212 of the base meter are joined is the front-to-back direction, the second direction in which the left cover 231 and the right cover 232 are joined can be the left-to-right direction.

[0073] Figure 4 This is a schematic diagram of the electrical connection of the ultrasonic gas meter provided in the embodiment of the present application. Figure 3 and Figure 4 As shown, as for the electrical connection between the metering module 220 and the controller 100 , a module circuit board 221 may be provided in the metering module 220 , and the module circuit board 221 in the metering module 220 is electrically connected to the main control board 120 in the controller 100 .

[0074] Specifically, the module circuit board 221 of the metering module 220 is connected to the main control board 120 of the controller 100 via a signal line, and the signal line connects the main control board 120 and the part of the module circuit board 221 that needs to transmit the control signal. In addition, the main control board 120 may also include a reference ground terminal 121 ( Figure 4 The module circuit board 221 may include a ground terminal 2211 (GND in the main control board 120 shown in FIG). Figure 4 The ground terminal 2211 of the module circuit board 221 is electrically connected to the reference ground terminal 121 of the main control board 120 to achieve signal grounding of the module circuit board 221.

[0075] Reference Figure 4 As shown, the main control board 120 of the controller 100 may further include a protection ground terminal 122 ( Figure 4 The PE in the main control board 120 shown in FIG, the protective ground terminal 122 of the main control board 120 and the reference ground terminal 121 of the main control board 120 can be connected to each other via an AC capacitor. In addition, the protective ground terminal 122 of the main control board 120 is electrically connected to the case 210 of the base meter 200, for example, the protective ground terminal 122 of the main control board 120 is electrically connected to the front case 211 of the base meter.

[0076] By providing a protective earth terminal 122 on the main control board 120 of the controller 100 and electrically connecting the protective earth terminal 122 of the main control board 120 to the case 210 of the base meter 200, the main control board 120 can be protectively grounded. The case 210 of the base meter 200 can be provided with a grounding wire, and current can be discharged to the ground along the grounding wire of the case 210 to achieve safety.

[0077] Combine Figure 3 and Figure 4 As shown, the ultrasonic gas meter 10 of this embodiment also includes a filter circuit board 300, which is electrically connected between the reference ground terminal 121 of the main control board 120 and the meter case 210 of the base meter 200. For example, the filter circuit board 300 is electrically connected between the reference ground terminal 121 of the main control board 120 and the base meter front case 211.

[0078] The interference signals on the main control board 120 and the connection lines connected to the main control board 120 can be transmitted to the watch case 210 through the filter circuit board 300, so as to reduce or even avoid the electromagnetic interference of the interference signals on the metering module 220, enhance the stability of the metering module 220, and improve the metering accuracy of the metering module 220.

[0079] Among them, reference Figure 4 As shown, the filter circuit board 300 may include a reference ground portion 310 ( Figure 4 GND in the filter circuit board 300 shown in FIG), the filter circuit 320 and the protection ground portion 330 ( Figure 4 PE in the filter circuit board 300 shown in FIG), the reference ground portion 310 and the protective ground portion 330 can be electrically isolated, and the two are connected through the filter circuit board 320. For example, the reference ground portion 310 and the protective ground portion 330 can be arranged on both sides of the filter circuit board 300, and the filter circuit 320 is arranged between the reference ground portion 310 and the protective ground portion 330. The reference ground portion 310 of the filter circuit board 300 is electrically connected to the reference ground terminal 121 of the main control board 120, and the protective ground portion 330 of the filter circuit board 300 is electrically connected to the watch case 210, for example, the protective ground portion 330 of the filter circuit board 300 is electrically connected to the base watch front case 211.

[0080] By first connecting the ground terminal 2211 on the module circuit board 221 of the metering module 220 to the reference ground terminal 121 of the main control board 120, and then connecting the reference ground terminal 121 of the main control board 120 to the reference ground portion 310 of the filter circuit board 300, and then connecting to the protective ground portion 330 of the filter circuit board 300 through the filter circuit 320, and finally connecting to the case 210, a limited flow path can be provided for interference signals generated on the main control board 120 and the connecting cables connected thereto.

[0081] Interference signals generated by the main control board 120 and its connecting lines are conducted along this defined flow path by the filter circuit board 300 to the case 210. Since the case 210 (e.g., the base front case 211) is generally a metal body with a large surface area, the equivalent impedance of the case 210 is very low, and the introduction of interference signals does not cause significant voltage changes. Therefore, the reference signal at the ground terminal 2211 of the metering module 220 also becomes very stable, thereby improving the operating stability of the metering module 220 and enhancing the metering accuracy of the metering module 220.

[0082] Furthermore, as previously mentioned, since the main control board 120 of the controller 100 also includes a protective earth terminal 122, the ground terminal 2211 on the module circuit board 221 of the metering module 220 is connected to the reference ground terminal 121 of the main control board 120, and then connected to the protective earth terminal 122 of the main control board 120 via an AC circuit. The protective earth terminal 122 of the main control board 120 is then connected to the meter case 210 (e.g., the base meter front case 211). This provides another ground loop for interference signals on the main control board 120 and its connecting cables.

[0083] In this way, the interference signals generated by the main control board 120 and its connecting lines can be transmitted to the watch case 210 via the filter circuit board 300, or directly transmitted to the watch case 210 via the protective ground terminal 122 of the main control board 120. This arrangement forms a multi-point grounding structure for the main control board 120, limiting the return path of the interference signals and effectively filtering out interference signals caused by electromagnetic interference.

[0084] In some embodiments, the filter circuit board 300 can be disposed between the controller 100 and the base meter 200. For example, the filter circuit board 300 can be disposed between the controller rear housing 112 and the base meter front housing 211 (e.g., Figure 3 shown).

[0085] With this arrangement, the filter circuit board 300 is sandwiched between the controller rear housing 112 and the base watch front housing 211. The filter circuit board 300 is relatively close to the main control board 120 of the controller 100, and is also relatively close to the case 210 of the base watch 200, facilitating connection between the filter circuit board 300, the main control board 120, and the case 210. The filter circuit board 300 can be connected to the base watch front housing 211, which is close to it.

[0086] In this case, the filter circuit board 300 can be connected to the main control board 120 of the controller 100 via a connecting wire, and the filter circuit board 300 can also be connected to the base meter front housing 211 via a connecting wire. The connecting wires between the filter circuit board 300 and the main control board 120 and between the filter circuit board 300 and the base meter front housing 211 are both very short, which can improve the filter circuit board 300's ability to filter out interference signals and enhance the stability of the metering module 220. Furthermore, the electrical connections between the filter circuit board 300, the main control board 120, and the base meter front housing 211 are stable and reliable.

[0087] Among them, since the controller rear shell 112 is separated between the filter circuit board 300 and the main control board 120, a wire hole (not shown in the figure) can be opened on the controller rear shell 112 to allow the connecting wire to pass through the controller rear shell 112 to connect the filter circuit board 300 and the main control board 120.

[0088] Figure 5 This is a cross-sectional view of another base table provided in an embodiment of the present application. Figure 5 As shown, in other embodiments, the filter circuit board 300 can also be disposed within the case 210 of the base watch 200. For example, the filter circuit board 300 can be mounted on the inner wall surface of the base watch front case 211. This places the filter circuit board 300 closer to the controller 100, facilitating connection between the filter circuit board 300 and the main control board 120 of the controller 100.

[0089] At this point, the filter circuit board 300 can still be connected to the base meter front housing 211 via the connecting wire 240. However, since the base meter front housing 211 and the controller rear housing 112 separate the filter circuit board 300 and the main control board 120, it is not convenient to connect the filter circuit board 300 to the main control board 120. To address this issue, contact pins 250 can be provided on the main control board 120 or the filter circuit board 300 to achieve electrical contact between the main control board 120 and the filter circuit board 300. This configuration makes the electrical connection between the filter circuit board 300 and the main control board 120 more flexible, facilitating assembly and disassembly of the controller 100 and the base meter 200.

[0090] Of course, the filter circuit board 300 and the main control board 120 can also be electrically connected by connecting wires. Threading holes can be provided on both the base meter front shell 211 and the controller rear shell 112, so that the connecting wires pass through the base meter front shell 211 and the controller rear shell 112 in sequence to electrically connect the filter circuit board 300 and the main control board 120. In summary, the ultrasonic gas meter 10 provided in this embodiment, on the one hand, provides a shielding cover 230 on the outer periphery of the metering module 220 to electrically insulate the shielding cover 230 from the case 210 of the base meter 200. The shielding cover 230 and the case 210 work together to form a double-layer shielding protection for the metering module 220. The metering module 220 can be protected in all directions in space, effectively eliminating the electromagnetic interference of the electromagnetic radiation field on the metering module 220.

[0091] On the other hand, by setting up an electrical connection between the filter circuit board 300 and the main control board 120 of the controller 100 and the case 210 of the base meter 200, a limited flow loop can be provided for the interference signals generated on the main control board 120 and its connecting lines. These interference signals can be directly transmitted to the case 210 through the main control board 120, and can also be transmitted to the case 210 through the filter circuit board 300, providing a multi-point grounding loop for these interference signals, which can enhance the stability of the grounding terminal 2211 of the metering module 220.

[0092] Such an arrangement can not only ensure that the metering module 220 is not spatially interfered with by the electromagnetic radiation field, but also transmit the interference signals generated by the main control board 120 and the connecting wires to the watch case 210 .

[0093] Furthermore, it ensures that the metering module 220 is not affected by electromagnetic interference in all directions, enhances the working stability of the metering module 220, and improves the measurement accuracy of the metering module 220.

[0094] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on this application.

[0095] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some or all of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application.

Claims

1. An ultrasonic gas meter, characterized in that: include: A controller, comprising a housing and a main control board, wherein the main control board is disposed in the housing; a base meter connected to the rear side of the controller; The base meter includes a meter case and a metering module, the metering module is arranged in the meter case, and the ground terminal of the metering module is electrically connected to the reference ground terminal of the main control board; The filter circuit board is electrically connected between the reference ground terminal of the main control board and the case.

2. The ultrasonic gas meter according to claim 1, characterized in that: The filter circuit board includes a reference ground portion, a filter circuit and a protection ground portion, wherein the reference ground portion and the protection ground portion are electrically isolated and connected through the filter circuit; The reference ground portion is electrically connected to the reference ground terminal of the main control board, and the protection ground portion is electrically connected to the case.

3. The ultrasonic gas meter according to claim 1, characterized in that: The main control board further includes a protective ground terminal, the protective ground terminal of the main control board is electrically isolated from the reference ground terminal of the main control board, and the protective ground terminal of the main control board is electrically connected to the case.

4. The ultrasonic gas meter according to any one of claims 1 to 3, characterized in that: The filter circuit board is arranged between the controller and the base meter.

5. The ultrasonic gas meter according to claim 4, characterized in that: The filter circuit board is connected to the main control board via a connecting line, and the filter circuit board is connected to the watch case via a connecting line.

6. The ultrasonic gas meter according to claim 4, characterized in that: The housing of the controller includes a controller front housing and a controller rear housing connected to each other, the housing of the base meter includes a base meter front housing and a base meter rear housing connected to each other, and the controller rear housing is connected to the base meter front housing; Wherein, the filter circuit board is arranged between the controller rear shell and the base watch front shell, and the filter circuit board is electrically connected to the base watch front shell.

7. The ultrasonic gas meter according to any one of claims 1 to 3, characterized in that: The filter circuit board is arranged in the watch case of the base watch.

8. The ultrasonic gas meter according to claim 7, characterized in that: The filter circuit board is electrically connected to the main control board via contact pins.

9. The ultrasonic gas meter according to any one of claims 1 to 3, characterized in that: The base table also includes: The shielding cover is arranged in the case of the base meter and is electrically insulated from the case, and the shielding cover is arranged on the periphery of the metering module.

10. The ultrasonic gas meter according to claim 9, characterized in that: The base watch case includes a base watch front case and a base watch back case connected to each other, and the shielding cover includes a left cover body and a right cover body connected to each other; The docking direction of the base watch front shell and the base watch rear shell is a first direction, the docking direction of the left cover body and the right cover body is a second direction, and the first direction and the second direction have an angle.

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