Electricity larceny prevention meter box

Abstract

This application relates to an anti-theft electricity metering box, belonging to the field of electrical equipment technology. It includes a door, a box body, a locking device, and an alarm device. The lock cylinder of the locking device is rotatably mounted in a mounting slot in the box body, and the key has a complex unlocking structure and operating logic. The alarm device is located in the door; when the door is forcibly opened, the plug-in block displaces and presses against the trigger block, triggering a pressure sensor. When the pressure sensor detects a value exceeding a threshold, it activates the alarm, sounds an alarm sound, controls the main circuit breaker to cut off the power supply circuit to the metering box, and also sprays dye from the compression chamber through a nozzle. This application achieves the technical effect of improving the anti-theft performance of the metering box, promptly issuing an alarm, cutting off the power supply, and leaving a dye mark when forcibly opened, facilitating subsequent investigation.

Description

Technical Field

[0001] This application relates to the field of electrical equipment technology, and in particular to an anti-theft electricity metering box. Background Technology

[0002] In the field of electrical equipment technology, anti-theft metering boxes are crucial devices for ensuring the accuracy of electricity metering and the safe operation of power systems. With the continuous development of the power industry, the rational allocation and accurate metering of power resources are becoming increasingly important. The performance of anti-theft metering boxes directly affects the economic benefits of power companies and the stability of power supply. Their widespread application helps regulate the electricity market order, reduces the illegal theft and waste of power resources, and is of great significance for maintaining the normal operation of the power system and the stable development of society.

[0003] In related technologies, to prevent unauthorized opening of metering boxes for electricity theft, ordinary mechanical locks are commonly used to lock the box door and body. These mechanical locks have a relatively simple structure, typically consisting of a lock cylinder and a key; locking and unlocking are achieved by inserting the key into the lock cylinder and turning it. Some metering boxes are also equipped with simple alarm devices that sound an alarm when the door is detected to be open. Some metering boxes are also equipped with circuit breakers to cut off the power supply circuit when an abnormality is detected.

[0004] However, ordinary mechanical locks are easily cracked, and criminals can use simple tools such as crowbars to force their way in and steal electricity, failing to effectively guarantee the security of the meter box. Simple alarm devices may have false alarms or be slow to respond, unable to respond promptly and accurately to illegal opening attempts. Moreover, when the meter box is forcibly opened, it is impossible to effectively mark the electricity thieves, which is not conducive to subsequent tracking and investigation. Summary of the Invention

[0005] The purpose of this application is to overcome the above-mentioned technical problems and provide an anti-theft electricity metering box.

[0006] An anti-theft electricity metering box includes a door and a body, as well as a locking device and an alarm device;

[0007] The locking device includes a key and a lock cylinder. The lock cylinder is rotatably mounted in the mounting slot of the housing. The lock cylinder has clearance holes and circumferentially distributed matching slots.

[0008] The key includes a housing, inside which a first locking block is slidably connected. The first locking block is connected to the bottom of the housing via a first return spring. The first locking block has symmetrical unlocking slots, and two unlocking blocks are slidably connected within the unlocking slots. The unlocking blocks are connected via a second return spring.

[0009] The first locking block is coaxially slidably connected to the second locking block. The second locking block passes through the outer shell and its outer end is connected to the third return spring. The second locking block is equipped with a fixing rod and a fourth return spring connected to the fixing plate. The fixing rod extends into the slot of the first locking block.

[0010] The alarm device includes a plug-in housing installed on the door, an operating cavity inside the plug-in housing, a plug-in block slidably connected inside the operating cavity, the plug-in block being connected to a trigger block via a pressure spring, and the trigger block being in contact with a pressure sensor.

[0011] The plug-in block is fixed with an extrusion plate, and a bracket hole is opened on the extrusion plate. The plug-in shell is connected to the compression bladder through the fixing plate. The compression bladder is connected to the nozzle through a sealing element. The nozzle passes through the bracket hole and has a sealing block with a nozzle at its end.

[0012] The pressure sensor is electrically connected to an alarm and a main circuit breaker.

[0013] By adopting the above technical solutions, the locking device can lock and unlock the door and the box body. The alarm device can trigger the pressure sensor when the metering box is forcibly opened, thereby causing the alarm to sound and controlling the main circuit breaker to cut off the power supply circuit of the metering box. At the same time, the dye in the compression bladder can be sprayed through the nozzle to mark the person who forcibly opens the box, thereby improving the security of the anti-theft metering box.

[0014] Optionally, the key's operating logic is as follows: push the second lock block to cause the fixing rod to move the first lock block synchronously, and the first lock block passes through the clearance hole; continue to push the second lock block to stretch the fourth return spring, and the end of the second lock block abuts against the unlocking block and drives the unlocking block to extend along the unlocking groove; after the unlocking block is inserted into the matching groove, rotate the outer shell to drive the lock cylinder to rotate and unlock.

[0015] By adopting the above technical solution, the key and lock cylinder can be unlocked by working together. Pushing the second lock block causes the first lock block to pass through the clearance hole. Pushing it again causes the unlocking block to extend and insert into the matching slot. Rotating the outer shell can drive the lock cylinder to rotate and unlock, making it convenient to open the door of the anti-theft electricity metering box.

[0016] Optionally, the unlocking block is provided with a limiting protrusion, and a limiting groove is opened in the unlocking groove, with the limiting protrusion extending into the limiting groove; the contact surface between the unlocking block and the mating groove is provided with staggered toothed blocks.

[0017] By adopting the above technical solution, the limiting protrusion extending into the limiting groove can limit the movement of the unlocking block and prevent the unlocking block from moving excessively; the staggered teeth on the contact surface between the unlocking block and the mating groove can make the key and the lock cylinder firmly connected, improve the stability and reliability of the locking device, and enhance the anti-theft capability of the anti-electricity metering box.

[0018] Optionally, the lock cylinder is provided with a snap-fit ​​boss, and the plug block is provided with a corresponding snap-fit ​​recess. When the lock cylinder rotates, the snap-fit ​​boss and the snap-fit ​​recess engage and fix it. A permanent magnet is embedded in the snap-fit ​​boss, and the permanent magnet and the plug block are magnetically attracted. When the door is forcibly opened, the plug block moves along the operating cavity and presses the trigger block, which compresses the pressure spring and triggers the pressure sensor.

[0019] By adopting the above technical solution, when the lock cylinder rotates, the locking boss and the locking recess engage and fix, which can lock the door and the box body; the permanent magnet and the plug block are magnetically attracted, which can improve the connection stability; when the door is forcibly opened, the plug block is displaced and presses the trigger block, which compresses the pressure spring and triggers the pressure sensor, which can detect abnormal opening behavior in time and provide conditions for subsequent alarm triggering and power-off operations.

[0020] Optionally, when the pressure sensor detects a value that exceeds the threshold for ≥1 second, the following actions are triggered simultaneously: the alarm is activated to emit an alarm sound of ≥90dB; the main circuit breaker is controlled to cut off the power supply circuit to the metering box; the trigger block pushes the extrusion plate to move, causing the compression bladder to be squeezed and deformed, and the internal dye is sprayed through the nozzle.

[0021] By adopting the above technical solution, when the pressure sensor detects a value that exceeds the threshold for ≥1 second, an alarm can be activated simultaneously to emit an alarm sound of ≥90dB to warn against illegal opening behavior. The main circuit breaker is controlled to cut off the power supply circuit of the metering box to prevent electricity theft. The trigger block pushes the extrusion plate to compress and deform the compression bladder, allowing the internal dye to be sprayed through the nozzle, which can mark the illegal opening personnel.

[0022] Optionally, the nozzle outlet end is flush with the outer surface of the box door, and the spray axis forms an angle of 15°-30° with the box door plane, with a nozzle diameter of 0.3-0.5mm.

[0023] By adopting the above technical solution, the nozzle outlet end is flush with the outer surface of the box door, which can prevent the nozzle from protruding and being damaged; the spray axis forms an angle of 15°-30° with the box door plane and the nozzle diameter is 0.3-0.5mm, which can ensure accurate spraying of dye.

[0024] Optionally, the compression bladder is filled with a fast-drying fluorescent dye; the trigger threshold of the pressure sensor is 8N±10%.

[0025] By adopting the above technical solution, the compression bladder is filled with a fast-drying fluorescent dye, which can mark the person who forcibly opens the metering box, making it easier to track them later; by setting the trigger threshold of the pressure sensor to 8N±10%, it can accurately determine whether the box door has been forcibly opened.

[0026] Optionally, the compression bladder is provided with a gas chamber and a liquid chamber. The gas chamber is pre-filled with compressed nitrogen at 0.5 MPa, and the dye is placed in the liquid chamber. The gas chamber and the liquid chamber are separated by a ruptureable diaphragm. A needle is provided on the inner side of the extrusion plate. When triggered, the needle punctures the diaphragm, causing the compressed nitrogen to squeeze the dye in the liquid chamber.

[0027] By adopting the above technical solution, when the alarm device is triggered by violently opening the box door, the needle punctures the fragile diaphragm, and the 0.5MPa compressed nitrogen pre-filled in the gas chamber will squeeze the dye in the liquid chamber, increasing the flow rate of the dye sprayed out of the nozzle, which can better mark the electricity thief.

[0028] In summary, this application includes at least one of the following beneficial technical effects:

[0029] 1. The locking device uses a unique operating logic to engage the key and lock cylinder, allowing the unlocking block to be inserted into the matching slot and rotate the outer shell to drive the lock cylinder to rotate and unlock. This effectively prevents the metering box from being illegally opened and solves the problem that ordinary mechanical locks are easily cracked.

[0030] 2. When the cabinet door is forcibly opened and the pressure sensor reading exceeds the threshold for ≥1 second, the alarm will sound an alarm sound of ≥90dB, which can respond to illegal opening behavior in a timely manner and avoid the problems of false alarms or insensitive response of simple alarm devices;

[0031] 3. When the box door is forcibly opened, the trigger block pushes the compression plate to move, causing the dye in the compression bladder to be sprayed through the nozzle, which can effectively mark the electricity thief and facilitate subsequent tracking and investigation. Attached Figure Description

[0032] Figure 1 This is a schematic diagram of the overall structure of this application;

[0033] Figure 2 This is a structural diagram of the present application, mainly showing the storage box;

[0034] Figure 3 yes Figure 2 A magnified view of part A in the middle;

[0035] Figure 4 This is a cross-sectional structural diagram of this application, mainly showing the key;

[0036] Figure 5 yes Figure 4 A magnified view of part B in the middle section;

[0037] Figure 6 This is a structural diagram of the present application, mainly showing the lock cylinder;

[0038] Figure 7 This is a cross-sectional structural diagram of the present application, mainly showing the compression bladder.

[0039] Attached Figure Descriptions: 1. Door; 2. Box Body; 3. Key; 301. Outer Shell; 302. Outer Side Panel; 303. First Return Spring; 304. First Lock Block; 305. Positioning Block; 306. Unlocking Block; 307. Second Return Spring; 308. Limiting Protrusion; 309. Second Lock Block; 310. Third Return Spring; 311. Fixing Rod; 3111. Locking Block; 3112. Fifth Return Spring; 312. Fourth Return Spring; 4. Lock Cylinder; 401. Locking Boss; 402. Permanent Magnet; 5. Alarm Device; 501. Insertion Shell; 502. Insertion Block; 503. Pressure Sensor; 504. Pressure Spring; 505. 506. Trigger block; 507. Storage box; 508. Sealing plate; 509. Main circuit breaker; 510. Alarm; 511. Fixing plate; 512. Compression bladder; 513. Fragile diaphragm; 514. Squeezing plate; 515. Sealing block; 516. Needle; 6. First slide groove; 7. First positioning groove; 8. Second slide groove; 9. Unlocking groove; 10. Limiting groove; 11. Snap-in groove; 12. Third slide groove; 13. Mounting groove; 14. Clearance hole; 15. Pairing groove; 16. Clearance groove; 17. Tooth block; 18. Operating chamber; 19. Snap-in notch; 20. Metal sheet; 21. Liquid chamber; 22. Gas chamber; 23. Bracket hole. Detailed Implementation

[0040] The following is in conjunction with the appendix Figure 1 -Appendix Figure 7 This application will be described in further detail below.

[0041] A type of anti-theft electricity metering box, referring to Figure 1 The metering box includes a door 1, a body 2, a locking device, and an alarm device 5. The body 2 is made of PC+ABS plastic. The locking device is mounted on the body 2, and the alarm device 5 is detachably mounted on the door 1. The locking device is used to lock the door 1 to the body 2. The alarm device 5 is used to cut off the power to the metering box when it is forcibly opened, and simultaneously sprays a dye mark on the person who forcibly opens it and sounds an alarm.

[0042] Reference Figure 2 , Figure 3 , Figure 4The locking device includes a key 3 and a lock cylinder 4. The key 3 includes a housing 301, one end of which is fixedly connected to two outer plates 302 for convenient operation. A first sliding groove 6 is formed inside the housing 301. A first return spring 303 is fixedly connected to the bottom of the groove near the outer plate 302. A first locking block 304 is fixedly connected to the end of the first return spring 303, and the first locking block 304 slides within the first sliding groove 6. In addition, a through hole is formed at the bottom of the groove away from the outer plate 302 for the first locking block 304 to pass through. Furthermore, a first positioning groove 7 is formed on the side wall of the first sliding groove 6. A positioning block 305 is fixedly connected to the surface of the first locking block 304. The positioning block 305 extends into the first positioning groove 7 and slides along the first positioning groove 7, so that when the housing 301 rotates, the first locking block 304 can rotate synchronously with the housing 301.

[0043] Reference Figure 4 The first locking block 304 has a second sliding groove 8, and an unlocking groove 9 is formed at the bottom of the second sliding groove 8 away from the first return spring 303. Two oppositely arranged unlocking blocks 306 are slidably connected in the unlocking groove 9. The first locking block 304 has through holes at both ends of the unlocking groove 9 for the unlocking blocks 306 to pass through. The cross-section of the unlocking block 306 is wedge-shaped, and its inclined surface is inclined towards the through hole and the first return spring 303. At the same time, the two unlocking blocks 306 are fixedly connected by a second return spring 307. Furthermore, a limiting groove 10 is formed in the inner wall of the unlocking groove 9, and a limiting protrusion 308 is fixedly connected to the side wall of the unlocking block 306. The limiting protrusion 308 extends into the limiting groove 10 and slides along the limiting groove 10. When the unlocking block 306 is fully extended, the limiting protrusion 308 abuts against the inner wall of the limiting groove 10.

[0044] Reference Figure 4 , Figure 5The second sliding groove 8 is slidably connected to a second locking block 309. The end of the second locking block 309 away from the unlocking block 306 passes through the first locking block 304 and the outer shell 301 in sequence. A third return spring 310 is fixedly connected to the end of the second locking block 309 outside the outer shell 301. One end of the third return spring 310 is fixedly connected to the surface of the outer shell 301. At the same time, a slot 11 is opened on the side wall of the second sliding groove 8, and a third sliding groove 12 is opened in the second locking block 309. A fixing rod 311 passes through the third sliding groove 12. The fixing rod 311 is hollow, and both ends of the fixing rod 3111 are slidably connected to a locking block 3111. The two locking blocks 3111 are fixedly connected by a fifth return spring 3112. After installation, the locking blocks 3111 are inserted into the slot 11. In addition, the fixing rod 311 is fixedly connected to the inner wall of the third slide groove 12 through the fourth return spring 312. The rigidity of the fourth return spring 312 is greater than that of the first return spring 303 and the third return spring 310, so that the first return spring 303 and the third return spring 310 deform before the fourth return spring 312 when compressed. After the fourth return spring 312 is deformed and compressed, the fixing rod 311 slides along the third slide groove 12. When the fixing rod 311 abuts against the side wall of the third slide groove 12, the second locking block 309 abuts against the two unlocking blocks 306 and pushes the two unlocking blocks 306 to extend out of the first locking block 304.

[0045] Reference Figure 3 , Figure 4 , Figure 6 The housing 2 has a mounting groove 13, and the lock cylinder 4 is rotatably connected to the bottom of the mounting groove 13. The lock cylinder 4 has a clearance hole 14 for the first lock block 304 to pass through. At the same time, a matching groove 15 distributed circumferentially is formed on the inner side of the clearance hole 14. When the first lock block 304 passes through the clearance hole 14, and the second lock block 309 triggers the unlocking block 306 to extend out of the first lock block 304 along the unlocking groove 9, the unlocking block 306 is inserted into the matching groove 15. In addition, the contact surfaces of the unlocking block 306 and the matching groove 15 are integrally formed with teeth 17, and the teeth 17 on the unlocking block 306 and the teeth 17 on the inner wall of the matching groove 15 are staggered. This ensures that the key 3 and the lock cylinder 4 can be securely connected. In addition, a clearance groove 16 is provided on the side wall of the mounting groove 13. A snap-fit ​​boss 401 is fixedly connected to the lock cylinder 4, and the snap-fit ​​boss 401 can rotate in the clearance groove 16. One side of the clearance groove 16 is connected to the inside of the box 2. When the key 3 is connected to the lock cylinder 4, the snap-fit ​​boss 401 can be driven to extend into or out of the inside of the box 2 through the clearance groove 16 by rotating the key 3.

[0046] Reference Figure 3 , Figure 7The alarm device 5 includes a plug-in housing 501 fixed to the door 1 by screws. An operating cavity 18 is formed inside the plug-in housing 501, and a plug-in block 502 is slidably connected within the operating cavity 18. The plug-in block 502 has a snap-in recess 19 corresponding to the position of the snap-in boss 401. When the key 3 drives the snap-in boss 401 to rotate, it engages and is fixed with the snap-in recess 19. Furthermore, a permanent magnet 402 is embedded in the snap-in boss 401, and a metal sheet 20 is fixedly connected to the bottom surface of the snap-in recess 19. After the snap-in boss 401 engages with the snap-in recess 19, the permanent magnet 402 and the metal sheet 20 are magnetically connected, thereby improving the connection stability between the snap-in boss 401 and the snap-in recess 19. Simultaneously, the surface of the permanent magnet 402 is coated with epoxy resin to increase its service life.

[0047] Reference Figure 2 , Figure 7 A pressure sensor 503 is fixedly connected to the inner wall of the operating chamber 18 on the side away from the door 1. A pressure spring 504 is fixedly connected to the side of the plug block 502 near the pressure sensor 503, and a trigger block 505 that abuts against the surface of the pressure sensor 503 is fixedly connected to the end of the pressure spring 504. Meanwhile, a storage box 506 is fixedly connected inside the box 2. A sealing plate 507 is fixed to the storage box 506 by screws. A main circuit breaker 508, electrically connected to the pressure sensor 503, is fixedly connected inside the storage box 506 and is connected to the power supply circuit of the metering box. Additionally, an alarm 509 is fixedly connected inside the box 2 and is electrically connected to the pressure sensor 503. When the door 1 is forcibly opened, the plug block 502 moves along the operating chamber 18 and presses the trigger block 505, causing the pressure spring 504 to compress and trigger the pressure sensor 503. When the pressure detected by the pressure sensor 503 is 8N±10% and the duration exceeds ≥1s, the pressure sensor 503 transmits an electrical signal to the alarm 509 and the main circuit breaker 508, causing the alarm 509 to emit an alarm sound of 90dB or higher and controlling the main circuit breaker 508 to cut off the power supply circuit of the metering box.

[0048] Reference Figure 1 , Figure 6 , Figure 7 A fixing plate 510 is fixedly connected to the plug-in shell 501. A rubber compression bladder 511 is fixedly connected to the end of the fixing plate 510. Several compression creases are provided on the surface of the compression bladder 511. A fragile diaphragm 512 is fixedly connected to the side of the compression bladder 511 away from the door 1, and the fragile diaphragm 512 divides the inside of the compression bladder 511 into a liquid chamber 21 and a gas chamber 22. In addition, the gas chamber 22 is pre-filled with nitrogen gas at 0.5 MPa, and the liquid chamber 21 is pre-injected with a fast-drying fluorescent dye.

[0049] A compression plate 513 is fixedly connected to the plug-in block 502, and a support hole 23 is provided on the compression plate 513. A nozzle 514 communicating with the liquid chamber 21 is fixedly connected to the compression bladder 511 through a sealing element. The nozzle 514 passes through the support hole 23 of the compression plate 513 and the door 1. In addition, the end of the nozzle 514 is flush with the door 1, and a sealing block 515 with a spray hole is fixedly connected to the end of the nozzle 514 inside the door 1. The diameter of the spray hole is 0.3-0.5mm and it is opened at an angle, with its axis forming an angle of 15°-30° with the plane of the door 1, so as to ensure that the dye can be sprayed accurately. In addition, a needle 516 is fixedly connected to the inside of the compression plate 513, and the needle 516 passes through the compression bladder 511 and extends into the liquid chamber 21, and is aligned with the fragile diaphragm 512 inside the compression bladder 511. When forcibly opened, the plug block 502 connects to the lock cylinder 4, causing the door 1 to move the plug shell 501 closer to the plug block 502, thereby causing the fixing plate 510 to move closer to the compression plate 513 and the compression bladder 511 to deform and compress. When the compression bladder 511 deforms, the dye inside the compression bladder 511 is squeezed and sprayed out along the nozzle 514. In addition, when the piercing needle 516 punctures the fragile diaphragm 512, the high-pressure nitrogen in the gas chamber 22 further squeezes the dye, thereby increasing the flow rate of the dye sprayed out of the nozzle 514.

[0050] The implementation principle of this application embodiment is as follows: When the metering box is opened normally, the staff holds the key 3 and pushes the second lock block 309 first. Since the rigidity of the fourth return spring 312 is greater than that of the first return spring 303 and the third return spring 310, the first return spring 303 and the third return spring 310 are compressed first. The second lock block 309 drives the fixed rod 311 to move. The fixed rod 311 drives the first lock block 304 to move synchronously, so that the first lock block 304 passes through the clearance hole 14 of the lock cylinder 4. Continue pushing the second locking block 309, the fourth return spring 312 begins to stretch, the end of the second locking block 309 abuts against the unlocking block 306 and drives the unlocking block 306 to extend along the unlocking groove 9, the unlocking block 306 is inserted into the matching groove 15 of the lock cylinder 4, at this time rotate the outer shell 301 of the key 3, the outer shell 301 drives the first locking block 304 to rotate, the first locking block 304 engages with the tooth block 17 of the lock cylinder 4 through the unlocking block 306, driving the lock cylinder 4 to rotate, the locking boss 401 of the lock cylinder 4 rotates and disengages from the locking recess 19 of the plug block 502, realizing the unlocking of the box door 1.

[0051] When unauthorized individuals forcibly open the door 1, the movement of the door 1 causes the plug-in block 502 to shift along the operating cavity 18. The plug-in block 502 presses against the trigger block 505, compressing the pressure spring 504 and triggering the pressure sensor 503. When the pressure sensor 503 detects a pressure value of 8N±10% for a duration of ≥1 second, it simultaneously triggers a series of actions. On one hand, the pressure sensor 503 controls the alarm 509 to emit an alarm sound of 90dB or higher to warn against illegal opening; on the other hand, it controls the main circuit breaker 508 to cut off the power supply circuit to the metering box, preventing electricity theft. At the same time, the trigger block 505 pushes the compression plate 513 to shift, causing the compression bladder 511 to be compressed and deformed. The dye inside the compression bladder 511 is sprayed through the nozzle 514 to mark the unauthorized personnel. If the force used to open the valve is too great, the needles 516 inside the compression plate 513 will puncture the fragile diaphragm 512 inside the compression bladder 511. The 0.5MPa nitrogen gas pre-filled in the gas chamber 22 will compress the dye in the liquid chamber 21, further increasing the flow rate of the dye spray nozzle 514, improving the marking effect, and facilitating the subsequent tracking and investigation of electricity thieves.

[0052] The embodiments described in this specific implementation are preferred embodiments of this application and are not intended to limit the scope of protection of this application. Identical components are represented by the same reference numerals. Therefore, all equivalent changes made to the structure, shape, and principle of this application should be covered within the scope of protection of this application.

Claims

1. An anti-theft electricity metering box, comprising a door (1) and a body (2), characterized in that: It also includes locking devices and alarm devices (5); The locking device includes a key (3) and a lock cylinder (4). The lock cylinder (4) is rotatably disposed in the mounting groove (13) of the housing (2). The lock cylinder (4) is provided with a clearance hole (14) and a circumferentially distributed matching groove (15). The key (3) includes a housing (301), in which a first locking block (304) is slidably connected. The first locking block (304) is connected to the bottom of the housing (301) by a first return spring (303). The first locking block (304) is provided with symmetrical unlocking grooves (9). Two unlocking blocks (306) are slidably connected in the unlocking grooves (9). The unlocking blocks (306) are connected by a second return spring (307). The first locking block (304) is coaxially slidably connected to the second locking block (309). The second locking block (309) passes through the outer shell (301) and its outer end is connected to the third return spring (310). The second locking block (309) is provided with a fixing rod (311) and a fourth return spring (312) connected to the fixing plate (510). The fixing rod (311) extends into the slot (11) of the first locking block (304). The alarm device (5) includes a plug-in housing (501) disposed on the door (1), the plug-in housing (501) is provided with an operating cavity (18), a plug-in block (502) is slidably connected in the operating cavity (18), the plug-in block (502) is connected to a trigger block (505) through a pressure spring (504), and the trigger block (505) is in contact with a pressure sensor (503); The plug-in block (502) is fixed with an extrusion plate (513), and the extrusion plate (513) has a bracket hole (23). The plug-in shell (501) is connected to the compression bladder (511) through a fixing plate (510). The compression bladder (511) is connected to the nozzle (514) through a sealing element. The nozzle (514) passes through the bracket hole (23) and has a sealing block (515) with a spray hole at its end. The pressure sensor (503) is electrically connected to an alarm (509) and a main circuit breaker (508).

2. The anti-theft electricity metering box according to claim 1, characterized in that: The operation logic of the key (3) is as follows: Pushing the second locking block (309) causes the fixing rod (311) to move the first locking block (304) synchronously. The first locking block (304) has a clearance hole (14) through it. Continue pushing the second locking block (309) to stretch the fourth return spring (312), the end of the second locking block (309) abuts against the unlocking block (306) and drives the unlocking block (306) to extend along the unlocking groove (9); After the unlocking block (306) is inserted into the matching slot (15), the outer shell (301) is rotated to drive the lock cylinder (4) to rotate and unlock.

3. The anti-theft electricity metering box according to claim 2, characterized in that: The unlocking block (306) is provided with a limiting protrusion (308), and a limiting groove (10) is opened in the unlocking groove (9). The limiting protrusion (308) extends into the limiting groove (10). The contact surface between the unlocking block (306) and the mating groove (15) is provided with staggered tooth blocks (17).

4. The anti-theft electricity metering box according to claim 1, characterized in that: The lock cylinder (4) is provided with a locking protrusion (401), and the plug block (502) is provided with a corresponding locking recess (19). When the lock cylinder (4) rotates, the locking protrusion (401) engages and is fixed with the locking recess (19). The snap-fit ​​protrusion (401) is embedded with a permanent magnet (402), and the permanent magnet (402) is magnetically attracted to the plug block (502); When the box door (1) is forcibly opened, the plug block (502) moves along the operating cavity (18) and presses the trigger block (505), causing the pressure spring (504) to compress and trigger the pressure sensor (503).

5. The anti-theft electricity metering box according to claim 4, characterized in that: When the pressure sensor (503) detects a value that exceeds the threshold for ≥1 second, a synchronous trigger is activated: The alarm (509) is activated to emit an alarm sound of 90dB or higher; Control the main circuit breaker (508) to cut off the power supply circuit to the metering box; The trigger block (505) pushes the extrusion plate (513) to move, causing the compression bladder (511) to be squeezed and deformed, and the internal dye is sprayed through the nozzle (514).

6. The anti-theft electricity metering box according to claim 1, characterized in that: The outlet end of the nozzle (514) is flush with the outer surface of the box door (1), and the spray axis forms an angle of 15°-30° with the plane of the box door (1). The diameter of the spray hole is 0.3-0.5mm.

7. The anti-theft electricity metering box according to claim 1, characterized in that: The compression bladder (511) is filled with a fast-drying fluorescent dye; The trigger threshold of the pressure sensor (503) is 8N±10%.

8. The anti-theft electricity metering box according to claim 7, characterized in that: The compression bladder (511) is provided with a gas chamber (22) and a liquid chamber (21). The gas chamber (22) is pre-filled with compressed nitrogen gas at 0.5 MPa. The dye is placed in the liquid chamber (21). The gas chamber (22) and the liquid chamber (21) are separated by a fragile diaphragm (512). The inner side of the extrusion plate (513) is provided with a needle (516). When triggered, the needle (516) punctures the diaphragm, causing compressed nitrogen gas to squeeze the dye in the liquid chamber (21).

Images