An automatic meter reading device and method for mechanical water meters

Abstract

The invention relates to the technical field of mechanical water meters, and discloses an automatic meter reading device for a mechanical water meter and a meter reading method thereof, comprising a connection cover, a fastening ring, and a meter reading device connected to the mechanical water meter through the connection cover and the fastening ring, the meter reading device comprising a housing, a micro camera, a fill light LED lamp, a water immersion sensor, a control circuit board, and a power module for power supply; a wide circular ring protrudes outward from the upper end of the connection cover, the inner diameter of the fastening ring is slightly larger than the outer diameter of the lower end of the connection cover and smaller than the outer diameter of the wide circular ring at the upper end of the connection cover, an internal thread is arranged on the inner wall of the fastening ring, a stepped external thread joint is arranged at the lower end of the housing, the internal thread of the fastening ring matches the thread of the stepped external thread joint at the lower end of the housing, and the connection cover is provided with an internal thread, which matches the external thread on the mechanical water meter. Compared with the prior art, the invention has strong adaptability, only replaces the copper cover on the original mechanical water meter, and has the characteristics of state monitoring, quick installation, and convenient maintenance, and meets the requirements of manual and automatic meter reading at the same time.

Description

Technical Field

[0001] The invention relates to the technical field of mechanical water meters, and in particular to an automatic meter reading device and a meter reading method for a mechanical water meter. Background Art

[0002] With the rapid development of information and communication technology and the continuous maturity of Internet of Things technology, the traditional manual meter reading method in the water industry has been gradually replaced by remote automatic meter reading. One solution for automatic meter reading is to use an electronic water meter with automatic meter reading function, and another solution is to attach a meter reading device to the traditional mechanical water meter to achieve remote automatic meter reading. The mechanical and electronic parts of the currently used electronic water meters are located in the same housing. When there is a leak or other fault, not only can the data not be read, but the entire water meter needs to be removed for repair. At the same time, due to the huge number of mechanical water meters and the high replacement cost, it is necessary to attach an automatic meter reading device to achieve remote automatic meter reading of mechanical water meters for a period of time.

[0003] Water meters are usually installed indoors, outdoors or underground along pipelines. The use environment is complex, especially in the harsh environment of underground water meter wells with long-term humidity or even water accumulation. Therefore, additional automatic meter reading devices are required to have waterproof functions. An additional intelligent remote water meter reading device that is easy to install on site (CN 108051043 A) changes the imaging path of the digital disk by embedding a prism coated with a reflective aluminum film to lower the height of the device, solving the problem of being unable to be installed in the water meter box due to height, but it does not take into account installation in harsh environments such as flooding. A new type of intelligent remote water meter (CN 111765940 A) connects the water meter to the connecting lock nut through a thread, and the connecting lock nut is connected to the connecting main board of the meter reading device through a clamp and a screw. Although it can be automatically locked, the clamp fixing method cannot achieve complete waterproofing. Summary of the invention

[0004] Purpose of the invention: In view of the problems existing in the prior art, the present invention provides a mechanical water meter automatic meter reading device and a meter reading method thereof, which has the characteristics of waterproofing, status monitoring, quick installation, and convenient maintenance, and meets the requirements of manual and automatic meter reading at the same time.

[0005] Technical solution: The present invention provides an automatic meter reading device for a mechanical water meter, which is applied to a mechanical water meter and includes a connection cover, a fastening ring, and a meter reading device connected to the mechanical water meter through the connection cover and the fastening ring. The meter reading device includes a housing, a miniature camera, a fill light LED lamp, a water immersion sensor, a control circuit board, and a power module for power supply;

[0006] The micro camera is installed in the housing and faces the mechanical water meter code area. The micro camera, the fill light LED lamp, and the water immersion sensor are connected to the control circuit board circuit.

[0007] A wide circular ring protrudes outward from the upper end of the connecting cover, the inner diameter of the fastening ring is slightly larger than the outer diameter of the lower end of the connecting cover and smaller than the outer diameter of the wide circular ring at the upper end of the connecting cover, an internal thread is arranged on the inner wall of the fastening ring, a stepped external thread joint is arranged at the lower end of the shell, the internal thread of the fastening ring matches the thread of the stepped external thread joint at the lower end of the shell, and the connecting cover is provided with an internal thread, which matches the external thread on the mechanical water meter.

[0008] Furthermore, a plurality of lead-sealing handles are arranged at intervals on the outer wall of the connection cover, and notches are arranged at positions corresponding to the lead-sealing handles at the lower end of the inner wall of the fastening ring.

[0009] Furthermore, a pair of fastening handles are also provided on the outer wall of the fastening ring.

[0010] Furthermore, a groove is arranged on the wide circular ring, and a first sealing ring is arranged in the groove.

[0011] Furthermore, a stepped external threaded joint is provided at the upper end of the shell, on which a second sealing ring is placed, and the upper end of the shell is threadedly connected to a top cover made of a transparent material.

[0012] Furthermore, a protective cover is rotatably connected to the top cover.

[0013] Furthermore, the control circuit board includes an upper circuit board and a lower circuit board, both of which are arranged in the shell, the upper circuit board is provided with a camera chip interface, a water immersion signal chip interface, an LED light interface and a power conditioning circuit, the lower circuit board is provided with a microprocessor chip and a storage chip, the microprocessor chip is connected to the storage chip, the microprocessor chip is connected to the micro camera and the water immersion sensor through the camera chip interface and the water immersion signal chip interface, the microprocessor chip is also provided with a trapezoidal correction algorithm, the trapezoidal correction algorithm performs digital recognition on the image taken by the micro camera; the fill light LED light is connected to the microprocessor chip through the LED light interface; the upper circuit board and the lower circuit board are connected through a cable.

[0014] Furthermore, the power module is a U-shaped soft-pack lithium battery, which is connected to each circuit module through a power conditioning circuit.

[0015] Furthermore, a 485 communication interface is also provided on the lower circuit board, the microprocessor chip is connected to the communication module via the 485 communication interface, and the communication module is connected to the host computer.

[0016] Furthermore, a clock chip is also provided on the lower circuit board, and is connected to the microprocessor chip via an interface.

[0017] The present invention also discloses a meter reading method based on the automatic meter reading device of a mechanical water meter, comprising the following steps:

[0018] S1: Timing meter reading, according to the preset meter reading time in the microprocessor chip, when the clock chip reaches the preset meter reading time, the microprocessor chip controls the LED light to turn on, the micro camera tilts to take pictures, the microprocessor chip performs trapezoidal correction on the graphics, and digitally recognizes the corrected graphics, and automatically checks the recognition results;

[0019] S2: Communication meter reading. When the host computer sends a meter reading request through the communication interface, the communication interface sends the meter reading request to the microprocessor chip. The microprocessor chip controls the LED light to turn on and the micro camera to tilt and take pictures. The microprocessor chip performs trapezoidal correction on the graphics, and then performs digital recognition on the corrected graphics, and automatically checks the recognition results.

[0020] S3: abnormal alarm. When the water sensor receives a water signal, the microprocessor chip controls the LED light to turn on and the micro camera to tilt and take photos. The pictures and fault alarm signals are uploaded to the host computer and stored in the storage chip.

[0021] S4: According to the recognition results of steps S1 to S2, if it is lower than the last meter reading result, an error signal is output and re-recognition is performed; if the recognition error occurs 5 times in a row, the meter is re-photographed and re-recognized, and if the recognition is successful, the mechanical water meter reading result, the picture, and the shooting time parameters are stored in the storage chip and uploaded to the host computer; if the recognition is unsuccessful after 5 consecutive retakes, the current reading is marked as abnormal, and the microprocessor chip stores the picture and shooting time parameters in the storage chip and uploads it to the host computer;

[0022] S5: When meter reading is finished or abnormal alarm is finished, the microprocessor controls to turn off the fill light LED lamp (213), and ends meter reading and fault alarm.

[0023] Beneficial effects:

[0024] 1. The present invention replaces the copper cover above the original mechanical water meter with a connecting cover and a fastening ring, and connects a meter reading device through the connecting cover and the fastening ring. First, there is no need to replace the existing mechanical water meter structure. It is only necessary to replace the copper cover above the original mechanical water meter, and use the connecting cover and the fastening ring to thread the housing of the meter reading device, which is quick and convenient to install. The micro camera and the fill light LED lamp arranged in the meter reading device are used to take photos to perform meter reading work, thereby realizing the automatic meter reading function. Moreover, according to the water immersion sensor, the present invention is convenient for always monitoring the water inflow state of the mechanical water meter installed in a harsh environment such as water accumulation. When the water immersion sensor sends a water immersion signal, the micro camera is started to take a photo to perform image recognition of the water meter to determine whether there is water inflow or other abnormalities, or when performing water meter code image recognition, an abnormal situation is found, and an abnormal alarm is issued through the communication interface. Moreover, when the present invention is installed, the fastening ring is threadedly connected to the external thread at the lower end of the housing, the connecting cover is threadedly connected to the mechanical water meter, and the connecting cover is clamped and fixed with the fastening ring through a wide ring, so that the automatic meter reading device is convenient to connect with the existing mechanical water meter without falling off.

[0025] 2. The present invention provides a notch on the inner wall of the lower end of the fastening ring, which can effectively avoid the lead sealing handle of the connection cover. In addition, a fastening handle is provided on the outer wall of the fastening ring to facilitate the connection between the fastening ring and the lower end of the housing.

[0026] 3. The present invention sets a groove on the wide circular ring at the upper end of the connecting cover and places a first sealing ring in the groove. When the connecting cover is connected to the shell through the fastening ring, the first sealing ring is used to seal the shell and the mechanical water meter below, and water will not enter the mechanical water meter from the gap between the connecting cover and the shell, thereby achieving a waterproof effect.

[0027] 4. The present invention uses a transparent top cover to screw on the housing of the automatic meter reading device, so that the automatic meter reading can be realized while the manual meter reading can be realized, and the mechanical water meter value can be viewed through the transparent top cover on the housing. In addition, the second sealing ring arranged between the top cover and the housing can play a waterproof function to prevent water and dust from entering, meeting the requirements of video recording of water meter digital. The protective cover can protect the automatic meter reading device to prevent stones from falling and causing damage to it during use.

[0028] 5. The microprocessor chip of the control circuit board of the present invention is provided with a trapezoidal correction algorithm. The micro camera is used to take photos, and the algorithm is used to perform digital recognition and automatic inspection to complete the automatic meter reading function. The fill light LED lamp can illuminate the interior to prevent the photos taken by the micro camera from being too dark and unrecognizable. The power module uses a U-shaped soft-pack lithium battery to save the internal space of the housing.

[0029] 6. The communication module provided in the present invention can communicate with the host computer, upload the current detection status of the mechanical water meter to the host computer in real time, and when an abnormality occurs, it can promptly notify the host computer and arrange personnel for maintenance as soon as possible.

[0030] 7. The present invention sets a clock chip on the control circuit board to perform timing processing. The meter reading time can be pre-set on the control circuit board. According to the clock chip, the meter reading starts when the time is reached. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 Schematic diagram of mechanical water meter and automatic meter reading device;

[0032] Figure 2 Structural diagram of the connection cover and fastening ring;

[0033] Figure 3 Exploded view of the automatic meter reading device.

[0034] Among them, 1-mechanical water meter, 11-connection cover, 12-fastening ring, 13-first sealing ring, 14-lead sealing handle, 15-notch, 16-wide ring, 17-groove, 18-fastening handle, 2-meter reading device, 21-shell, 211-semi-cylinder, 212-mini camera, 213-fill light LED lamp, 214-water immersion sensor, 215-485 communication interface, 22-lower circuit board, 23-upper circuit board, 24-U-shaped soft-pack lithium battery, 25-second sealing ring, 26-top cover, 27-protective cover. DETAILED DESCRIPTION

[0035] The present invention will be further described below in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and cannot be used to limit the protection scope of the present invention.

[0036] See attached Figure 1 To Attachment Figure 3 The present invention discloses an automatic meter reading device for a mechanical water meter, which can be applied to a mechanical water meter in a harsh environment, and includes a connection cover 11, a fastening ring 12, and a meter reading device 2 connected to the mechanical water meter 1 through the connection cover 11 and the fastening ring 12. The meter reading device 2 includes a housing 21, a miniature camera 212, a fill light LED lamp 213, a water immersion sensor 214, a control circuit board, and a power module for power supply. In this embodiment, the power module uses a U-shaped soft-pack lithium battery 24.

[0037] The connection cover 11 replaces the original copper cover of the mechanical water meter 1. The lower part of the connection cover 11 has the same structure as the original copper cover, meeting the requirements of water meter sealing and anti-tampering lead sealing. In this embodiment, a 5mm wide ring 16 protrudes outward from the upper end of the connection cover 11. The wide ring 16 has a groove 17. When installed, a first sealing ring 13 is placed on the groove 17. Four lead sealing handles 14 are arranged at intervals on the outer wall of the connection cover 11.

[0038] Before installing the connection cover 11, place the fastening ring 12 on the mechanical water meter. Figure 2 The inner diameter of the fastening ring 12 is slightly larger than the outer diameter of the lower end of the connecting cover 11 and smaller than the outer diameter of the wide circular ring 16 at the upper end of the connecting cover 11. An internal thread is arranged on the inner wall of the fastening ring 12, and a stepped external thread joint is arranged at the lower end of the shell 21. The stepped external thread joint at the lower end of the shell 21 matches the internal thread of the fastening ring 12. The connecting cover 11 is provided with an internal thread, which matches the external thread on the mechanical water meter 1.

[0039] Four notches 15 are arranged at intervals within the inner ring at the bottom of the fastening ring 12 . The four notches 15 correspond to the positions of the four lead sealing handles 14 on the connecting cover 11 . When installing, avoid the lead sealing handles 14 of the connecting cover 11 . There are two fastening handles 18 on the outer wall of the fastening ring 12 .

[0040] See attached Figure 3 The housing 21 of the meter reading device 2 of the present invention is generally configured as a cylindrical structure that is wide at the top and narrow at the bottom. The narrow lower part of the housing 21 is a stepped external thread joint that matches the internal thread of the fastening ring 12. The upper wide part is composed of two semicircular structures. The control circuit board is placed in the semicircular space on one side, and the other side is a semi-cylindrical hollow structure. The top of the semi-cylinder 211 is made of transparent material. The semi-cylinder 211 is directly opposite to the code area of ​​the mechanical water meter 1 (the pointer type water meter is the black pointer area, and the word wheel type or pointer word wheel combination water meter is the word wheel area, the same below). The upper end of the housing 21 is also configured as a stepped external thread joint. A second sealing ring 25 is placed on the stepped external thread joint at the upper end of the housing 21, and then threadedly connected to the top cover 26 with the transparent material glued in the middle. A protective cover 27 is also rotatably connected to the top cover 26, which can be rotatably connected to the top cover 26 through a hinge, and the edge is fixed by a buckle.

[0041] The micro camera 212 is installed in the housing 21 and is directly opposite to the mechanical water meter code area 1. The micro camera 212, the fill light LED lamp 213, and the water immersion sensor 214 are connected to the control circuit board circuit. In this embodiment, the micro camera 212 and the fill light LED lamp 213 are installed on the upper inner side of the vertical facade of the semi-cylinder 211. The micro camera 212 is tilted toward the mechanical water meter code area, and the water immersion sensor 214 is installed below. After installation, the entire semi-cylinder 211 is injected with waterproof glue, which can withstand normal tap water pressure without leakage; there is a semi-annular space between the semi-cylinder 211 and the housing 21 for placing the U-shaped soft-pack lithium battery 24.

[0042] The control circuit board placed in the semicircular space on the other side of the housing 21 of the meter reading device 2 includes an upper circuit board 23 and a lower circuit board 22. The upper circuit board 23 is provided with a camera chip interface, a water immersion signal chip interface, an LED light interface and a power conditioning circuit, and the lower circuit board 22 is provided with a microprocessor chip and a storage chip. The microprocessor chip is connected to the storage chip, and the microprocessor chip is connected to the micro camera 212 and the water immersion sensor 214 through the camera chip interface and the water immersion signal chip interface. The microprocessor chip is also provided with a trapezoidal correction algorithm, which performs digital recognition of the image taken by the micro camera and automatically checks the recognition result; the fill light LED lamp is connected to the microprocessor chip through the LED light interface; the upper circuit board 23 and the lower circuit board 22 are connected through a flat cable. The U-shaped soft-pack lithium battery is connected to each circuit module through the power conditioning circuit to supply power to each circuit module.

[0043] The lower circuit board 22 is also provided with a 485 communication interface, and the microprocessor chip is connected to the communication module through the 485 communication interface, and the communication module is connected to the host computer. In this embodiment, a waterproof 485 communication interface 215 connected to the lower circuit board 22 is left on the outside of the housing 21, and the communication module can be connected to the communication module through the 485 communication interface 215. The communication module communicates with the host computer and can be used to receive meter reading instructions or transmit signal abnormality data, meter reading data, etc. to the host computer. The present invention adopts a method of separating the meter reading device 2 from the communication module, and provides data to the communication module, which can meet multiple communication modes such as wired and wireless, and can realize the sharing of communication modules by multiple meters, thereby reducing the cost of remote automatic meter reading. A clock chip is also provided on the lower circuit board 22, which is connected to the microprocessor chip through an interface.

[0044] The meter reading device 2 of the present invention has two meter reading modes: scheduled meter reading and communication interface command. At zero o'clock every day or when receiving the communication meter reading command, the meter reading device 2 turns on the fill light LED lamp 213, and the micro camera 212 takes a photo of the water meter code. The microprocessor chip MCU first performs trapezoidal correction on the graphics, and then performs digital recognition, and transmits the recognition result to the host computer through the 485 communication interface 215, and the recognition result and the picture are stored in the storage chip. When the water immersion sensor 214 sends a water immersion signal, the microprocessor chip MCU controls the micro camera 212 to start taking pictures to perform image recognition on the water meter to see if there are abnormalities such as water ingress, or if an abnormality is found when performing water meter code image recognition, the meter reading device 2 issues an abnormal alarm through the 485 communication interface 215.

[0045] The method of using the automatic meter reading device of the present invention is as follows:

[0046] Installation: When installing the automatic meter reading device, first close the water inlet valve of the mechanical water meter 1, remove the original copper cover of the water meter, put the fastening ring 12 on the mechanical water meter 1, and then connect the connecting cover 11 with the external thread on the mechanical water meter 1. Note: After the connecting cover 11 is tightened, the position of the lead seal hole corresponds to the position of the lead seal hole of the mechanical water meter 1. Then connect the meter reading device 2 with the mechanical water meter 1 below. Before connection, the first sealing ring 13 is completely located in the groove 17. The code area of ​​the mechanical water meter 1 is located in the middle of the semicircular transparent window of the meter reading device 2. The micro camera 212 faces the code area of ​​the mechanical water meter 1. Then move the fastening ring 12 upward, and make the notch 15 face the lead seal handle 14 of the connecting cover 11. Connect the internal thread of the fastening ring 12 with the external thread under the housing 21 of the meter reading device 2, and press the first sealing ring 13 on the connecting cover 11 to achieve waterproofing. Finally, use a waterproof connector to connect to the host computer through the waterproof 485 communication interface 215 of the meter reading device 2.

[0047] Use: The meter reading device 2 of the present invention has two levels of waterproof function. One is that the meter reading device 2 itself has a waterproof function. The other is that the meter reading device 2 and the mechanical water meter 1 form a waterproof space between the two through the connection cover 11. In the harsh environment of water immersion such as underground water meter wells, the requirements of video recording of water meter digital are met. The meter reading device 2 takes pictures by tilting the micro camera 212, and the pictures are corrected by trapezoidal diagrams to meet the requirements of graphic recognition, saving equipment space and reducing the size of the equipment, which can meet the installation requirements of small spaces. When the preset meter reading time comes, the fill light LED lamp 213 is turned on, the micro camera 212 takes a picture of the water meter digital reading, the microprocessor chip performs trapezoidal correction on the graphics, and then digitally recognizes the corrected graphics, and automatically checks the recognition result. If it is lower than the last meter reading result, it will be considered an error and will be re-recognized. If the recognition error occurs 5 times in a row, it will be re-photographed and re-recognized. If the recognition is successful, the water meter digital result, picture, and shooting time parameters are stored in the storage chip and can be uploaded to the host computer. The microprocessor chip controls the closing of the fill light LED lamp 213. If the recognition fails for 5 consecutive retakes, the current reading is marked as abnormal, and the microprocessor chip stores the current shooting picture and shooting time parameters in the storage chip and can upload them to the host computer, and the microprocessor chip controls to turn off the fill light LED lamp 213. When the host computer sends a meter reading request through the communication interface, the communication interface sends the meter reading request to the microprocessor chip, and the microprocessor chip continues to control to turn on the fill light LED lamp 213 and the micro camera 212.

[0048] When the mechanical water meter 1 breaks and leaks, the water sensor 214 in the meter reading device 2 receives the water signal, turns on the fill light LED 213 to shoot the picture, and uploads the picture and the fault alarm signal to the host computer and stores them in the storage chip. The clock, communication and water signal triggering mode are adopted. The device is in standby mode at ordinary times, and the working current is less than 3mA. Only when the preset meter reading time comes or there is a communication request and water signal, the whole machine will work, reducing the power consumption of the device. The meter reading device 2 of the present invention adopts a large-capacity U-shaped soft-pack lithium battery 24, which can meet the use time of 3 years when fully charged.

[0049] When it is necessary to manually read the meter on site, the protective cover can be opened to see the water level through the transparent semicircular window of the meter reading device 2, and the number can be directly read.

[0050] Maintenance: 1) Replace the battery. When the capacity of the U-shaped soft-pack lithium battery 24 reaches 15%, the microprocessor chip of the meter reading device 2 will send an alarm signal through the communication interface. When replacing the U-shaped lithium battery 24, the meter reading device 2 can be unscrewed when it is in a normal state without water immersion, or the top cover 26 of the device can be directly unscrewed, and the battery line can be unplugged to replace the U-shaped lithium battery 24. 2) Replace the meter reading device 2. When the meter reading device 2 cannot work normally due to a fault, the meter reading device 2 can be unscrewed and replaced with another one when it is in a normal state without water immersion.

[0051] Compared with the prior art, the dual waterproof function of the present invention meets the requirements of various harsh use environments indoors, outdoors and in water meter wells with flooding. One is the specific waterproof function of the meter reading device itself, and the other is that the meter reading device and the mechanical water meter form a waterproof space between the two through a connecting cover to prevent water and dust from entering. In addition, the device can determine whether the water meter is broken or other faults through the water immersion sensor combined with the image; the device stores the daily water meter readings, and can determine whether there is a water leakage site in the pipeline network through the regional water meter data. The present invention adopts a method of separating the meter reading device 2 from the communication module, and provides data to the communication module, which can meet multiple communication methods such as wired and wireless, and can realize the sharing of communication modules by multiple meters, reducing the cost of remote automatic meter reading; the meter reading device adopts a hollow transparent structure (the top cover 26 is transparent), and after installation, it can still meet the requirements of on-site manual meter reading.

[0052] The above embodiments are only for illustrating the technical concept and features of the present invention, and their purpose is to enable people familiar with the technology to understand the content of the present invention and implement it accordingly, and they cannot be used to limit the protection scope of the present invention. Any equivalent transformation or modification made according to the spirit of the present invention should be included in the protection scope of the present invention.

Claims

1. A mechanical water meter automatic meter reading device, applied to a mechanical water meter (1), characterized in that: It comprises a connection cover (11), a fastening ring (12), and a meter reading device (2) connected to the mechanical water meter (1) via the connection cover (11) and the fastening ring (12), the meter reading device (2) comprising a housing (21), a miniature camera (212), a fill light LED lamp (213), a water immersion sensor (214), a control circuit board, and a power supply module for powering; The micro camera (212) is installed in the housing (21) and faces the code area of ​​the mechanical water meter (1); the micro camera (212), the fill light LED lamp (213), and the water immersion sensor (214) are connected to the control circuit board circuit; A wide circular ring (16) protrudes outward from the upper end of the connection cover (11); the inner diameter of the fastening ring (12) is slightly larger than the outer diameter of the lower end of the connection cover (11) and smaller than the outer diameter of the wide circular ring (16) at the upper end of the connection cover (11); an inner wall of the fastening ring (12) is provided with an internal thread; a stepped external thread joint is provided at the lower end of the shell (21); the internal thread of the fastening ring (12) matches the thread of the stepped external thread joint at the lower end of the shell (21); and the connection cover (11) is provided with an internal thread that matches the external thread on the mechanical water meter (1); A groove (17) is provided on the wide circular ring (16), and a first sealing ring (13) is provided in the groove (17). The upper end of the housing (21) is also provided with a stepped external thread joint, on which a second sealing ring (25) is placed. The upper end of the housing (21) is threadedly connected to a top cover (26) made of a transparent material.

2. The automatic meter reading device for a mechanical water meter according to claim 1, characterized in that: A plurality of lead-sealing handles (14) are arranged at intervals on the outer wall of the connection cover (11), and notches (15) are arranged at positions corresponding to the lead-sealing handles (14) at the lower end of the inner wall of the fastening ring (12).

3. The automatic meter reading device for a mechanical water meter according to claim 1, characterized in that: The top cover (26) is also rotatably connected to a protective cover (27).

4. The automatic meter reading device for a mechanical water meter according to any one of claims 1 to 3, characterized in that: The control circuit board comprises an upper circuit board (23) and a lower circuit board (22), the upper and lower circuit boards are both arranged in the housing (21), the upper circuit board (23) is provided with a camera chip interface, a water immersion signal chip interface, an LED light interface and a power conditioning circuit, the lower circuit board (22) is provided with a microprocessor chip and a storage chip, the microprocessor chip is connected to the storage chip, the microprocessor chip is connected to the micro camera (212), the water immersion sensor (214) and the fill light LED light (213) via the camera chip interface, the water immersion signal chip interface and the LED light interface, the microprocessor chip is also provided with a trapezoidal correction algorithm, the trapezoidal correction algorithm performs digital recognition on the image captured by the micro camera (212); the upper circuit board (23) and the lower circuit board (22) are connected via a flat cable.

5. The automatic meter reading device for a mechanical water meter according to claim 4, characterized in that: The power module is a U-shaped soft-pack lithium battery (24), which is connected to each circuit module via a power conditioning circuit.

6. The automatic meter reading device for a mechanical water meter according to claim 5, characterized in that: The lower circuit board (22) is also provided with a 485 communication interface, the microprocessor chip is connected to the communication module via the 485 communication interface, and the communication module is connected to the host computer.

7. The automatic meter reading device for a mechanical water meter according to claim 6, characterized in that: The lower circuit board (22) is also provided with a clock chip, which is connected to the microprocessor chip via an interface.

8. A meter reading method based on the mechanical water meter automatic meter reading device according to claim 7, characterized in that: The steps include: S1: timing meter reading, according to the preset meter reading time in the microprocessor chip, when the clock chip reaches the preset meter reading time, the microprocessor chip controls the light-filling LED lamp (213) to be turned on, and the micro camera (212) to tilt and take pictures, the microprocessor chip performs trapezoidal correction on the graphics, and performs digital recognition on the corrected graphics, and automatically checks the recognition result; S2: Communication meter reading. When the upper computer sends a meter reading request through the communication interface, the communication interface sends the meter reading request to the microprocessor chip. The microprocessor chip controls the start of the fill light LED lamp (213) and the micro camera (212) to tilt and take photos. The microprocessor chip performs trapezoidal correction on the graphics, then performs digital recognition on the corrected graphics, and automatically checks the recognition results. S3: abnormal alarm, when the water immersion sensor (214) receives a water immersion signal, the microprocessor chip controls the light-filling LED (213) to be turned on, the micro camera (212) to tilt and take photos, and uploads the photos and fault alarm signals to the host computer and stores them in the storage chip; S4: According to the recognition result of steps S1 to S2, if it is lower than the last meter reading result, an error signal is output and the recognition is repeated; If the recognition is wrong for 5 consecutive times, the water meter will be re-photographed and re-recognized. If the recognition is successful, the reading result of the mechanical water meter (1) and the picture and shooting time parameters will be stored in the storage chip and uploaded to the host computer; if the recognition is unsuccessful for 5 consecutive times, the reading will be marked as abnormal, and the microprocessor chip will store the picture and shooting time parameters in the storage chip and upload them to the host computer; S5: When meter reading is finished or abnormal alarm is finished, the microprocessor controls to turn off the fill light LED lamp (213), and ends meter reading and fault alarm.

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