CN213477038U

CN213477038U - Anti-theft self-locking system for fire hydrant

Info

Publication number: CN213477038U
Application number: CN202022442626.1U
Authority: CN
Inventors: 刘亮; 蒲蜀茂
Original assignee: Dual-Flow Polyethylene Pipe Production Workshop Of Minjiang Waterworks In Chengdu; Chengdu Nuowei Technology Co ltd
Current assignee: Chengdu Nuowei Technology Co.,Ltd.; Sichuan Qingrun Pipe Industry Co.,Ltd.
Priority date: 2020-10-28
Filing date: 2020-10-28
Publication date: 2021-06-18
Anticipated expiration: 2030-10-28

Abstract

The utility model discloses a theftproof self-locking system for fire hydrant, which comprises a housin, above-mentioned casing upper end is equipped with the opening, be equipped with the valve pole of opening supply valve door in the above-mentioned opening, be equipped with the shielding cover on the above-mentioned opening, be used for by shielding cover switch opening, above-mentioned casing one side is equipped with locking mechanism, be used for sheltering from the cover removal by locking mechanism restriction, the above-mentioned casing outside is equipped with the ware of punching the card, the above-mentioned ware of punching the card is connected with locking mechanism electricity, by the opening of the above-mentioned locking mechanism of ware control that punches the card of the aforesaid, be used for by the above-mentioned ware of punching the card and monitor terminal data connection, with the current theftproof intelligence fire hydrant of expectation optimization, often appear because staff's maloperation, and make.

Description

Anti-theft self-locking system for fire hydrant

Technical Field

The utility model relates to a water supply line configuration, concretely relates to theftproof self-locking system for fire hydrant.

Background

The fire hydrant is a fixed water taking facility connected with a water supply pipeline and is a powerful guarantee for quickly extinguishing a big fire. In a fire-fighting system, fire hydrants are widely divided into indoor fire hydrants and outdoor fire hydrants, and the outdoor fire hydrants can provide water taking facilities for municipal construction and maintenance under necessary conditions besides providing main tasks for fire fighting of fire trucks or other mobile fire-fighting equipment. Such as for example, for municipal road construction, for municipal greening irrigation.

The water supply valve who opens the fire hydrant bottom through rotating the valve pole is to the fire hydrant usually, and the rotation of valve pole is the leading condition of water intaking promptly, and current intelligent theftproof fire hydrant sets up a limit gear at valve pole lower extreme usually, locks limit gear through embracing lock mechanism, effectively avoids the valve pole to rotate, opens through the key and embraces the lock mechanism after, by embracing the restraint of lock mechanism contact to limit gear to make the valve pole can normally rotate and accomplish the water intaking. In the actual application process of the fire hydrant, the phenomenon that the locking mechanism is violently broken due to misoperation of a user often occurs, and normal water taking of the valve rod is influenced. Therefore, how to improve the anti-theft self-locking component of the fire hydrant is worthy of study.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide a theftproof self-locking system for fire hydrant to expect to optimize current theftproof intelligence fire hydrant, often appear because staff's maloperation, and make easily that locking mechanism damages, influence the problem of user's normal water intaking.

In order to solve the technical problem, the utility model adopts the following technical scheme:

the anti-theft self-locking system for the fire hydrant comprises a shell, wherein an opening is formed in the upper end of the shell, a valve rod for opening a water supply valve is arranged in the opening, a shielding cover is arranged on the opening and used for opening and closing the opening through the shielding cover, a locking mechanism is arranged on one side of the shell and used for limiting the shielding cover to move through the locking mechanism, a card swiping device is arranged on the outer side of the shell and electrically connected with the locking mechanism, the card swiping device controls the locking mechanism to start and stop, and the card swiping device is used for being in data connection with a monitoring terminal.

Preferably, the locking mechanism is an electric control lock and is used for unlocking the shielding cover by electrifying the electric control lock, a limiting lock is arranged below the shielding cover and is electrically connected with the card reader, a limiting groove matched with the limiting lock is arranged at the lower end of the shielding cover and is used for releasing the shielding cover after the limiting lock is electrified and is used for delaying disconnection after the card reader is electrified to the limiting lock.

The shielding cover is provided with an opening, the opening is provided with a driving mechanism, the driving mechanism is used for driving the shielding cover to move, and the shielding cover is provided with a shielding cover.

Preferably, the locking mechanism is a push-pull electromagnet, a push-out mechanism is arranged on one side of the locking mechanism, a telescopic rod of the push-pull electromagnet is connected with the head end of the push-out mechanism, the tail end of the push-out mechanism is connected with a shielding cover, and the shielding cover is controlled to be opened and closed by the push-pull electromagnet; guide rails are arranged at two ends of the opening, and two ends of the shielding cover extend into the guide rails.

The technical scheme is that the pushing mechanism comprises a first rocker and a second rocker, the first rocker is connected with the locking mechanism, the second rocker is connected with the shielding cover, a lever is arranged between the first rocker and the second rocker, the first rocker and the second rocker are respectively connected with two ends of the lever, the lever is pushed and pulled by the first rocker, and the second rocker is driven by the lever to move.

A further technical scheme is that the end part of the second rocking rod is provided with a limit nut, the lever is provided with a strip-shaped hole corresponding to the limit nut, and the limit nut moves in the strip-shaped hole.

According to a further technical scheme, guide wheels are arranged in the shell and are positioned at the upper end and the lower end of a second rocker, and guide grooves matched with the guide wheels are formed in the second rocker.

Preferably, a push block is arranged at one end of the shielding cover, a negative pressure switch device corresponding to the push block is arranged in the shell, and the push block is abutted by the negative pressure switch device.

The technical scheme is that the negative pressure switch device comprises a cavity, an air valve assembly is arranged at the rear end of the cavity, a piston is arranged in the middle of the cavity, negative pressure is generated in the cavity through the air valve assembly, an inner convex portion is arranged in the cavity, a return spring is arranged between the inner convex portion and the piston, a push rod is arranged at the front end of the piston, the front end of the push rod extends out of the cavity, air is injected into the cavity through the air valve assembly to enable the push rod to abut against a push block, and thrust is applied to the piston through the return spring.

According to a further technical scheme, a limiting block is arranged at the tail end of the cavity, the limiting block limits the moving path of the piston, the air valve assembly comprises a check valve and a stop valve, air is injected into the cavity from the stop valve to enable the interior of the cavity to be positive pressure, and the air in the cavity is extracted from the check valve to enable the interior of the cavity to be negative pressure.

Compared with the prior art, the beneficial effects of the utility model are one of following at least:

the utility model discloses utilize locking mechanism control to shelter from the removal of lid, make and shelter from the lid and cover the opening of casing under the normality to avoid the staff to pass through spanner operating valve pole, during the water intaking, through the circular telegram of the ware control locking mechanism of punching the card, make locking mechanism control shelter from the lid and open, so that the user water intaking, thereby play the effect that prevents to reduce the water theft, and punch the card ware and carry out data connection with monitor terminal, the user state of the supervision fire hydrant of being convenient for.

The locking mechanism of the utility model is an electric control lock, the shielding cover is released through the electric control lock, the spacing lock is matched with the spacing groove, and the electrification delay is utilized, so that the worker can open the shielding cover by applying thrust to the operating handle within a certain time after swiping the card, and the shielding cover is locked again through the spacing lock after delay so as to keep the opening state; the power is switched on through secondary card swiping, the limiting lock and the electric control lock are unlocked, and the reset mechanism is utilized to enable the shielding cover to cover the opening after being reset.

The utility model discloses a push-out mechanism's first rocker passes through the lever by first rocker and promotes or stimulates the second rocker along with plug-type electro-magnet removes, makes the second rocker drive shelter from the lid antedisplacement or retreat to make first rocker effectively drive the long distance removal of second rocker through the short distance removal. Through the design of limit nut and bar hole, make the second rocker be in horizontal migration. And through guide pulley and guide slot, promote the stability that the second rocker moved.

The utility model discloses a negative pressure switch device adopts the physical action to open under emergency and shelters from the lid, makes relevant personnel can obtain the water permission under emergency, accords with the condition of a fire water demand.

The utility model discloses a negative pressure switching device, through the air valve subassembly take out from the air in the cavity, make the piston auto-lock backward, when necessary, pour into the air through the air valve subassembly, make the cavity form the malleation, promote the piston by reset spring again, make the push rod release and conflict ejector pad, drive by the ejector pad and shelter from the lid and remove.

The utility model discloses a stopper restraint piston avoids the piston to deviate from the cavity, is convenient for take out the air in the cavity through the check valve, makes cavity one end be in the negative pressure state, is convenient for manual operation through the stop valve, lets cavity and external atmosphere intercommunication through the stop valve, makes the air of injecting in the cavity obtain the malleation.

Drawings

Fig. 1 is a schematic structural diagram of an embodiment of the present invention.

Fig. 2 is a schematic structural diagram of another embodiment of the present invention.

Fig. 3 is a schematic diagram of the operation of the ejecting mechanism.

FIG. 4 is a schematic view of a second rocker structure.

Fig. 5 is a schematic structural diagram of the negative pressure switch device.

Description of reference numerals:

the device comprises a shell 1, a shell 2, an opening 2, a negative pressure switch 3, a shielding cover 4, a locking mechanism 5, a pushing mechanism 6, a card reader 7, a guide rail 8, a pushing block 9, a limiting block 10, a check valve 11, a stop valve 12, a guide wheel 13, a limiting lock 14, a cavity 301, an air valve assembly 302, a piston 303, an inner convex part 304, a reset spring 305, a push rod 306, a limiting groove 401, an operating handle 402, a reset mechanism 403, a first rocker 601, a second rocker 602, a lever 603, a limiting nut 604, a strip-shaped hole 606, a guide groove 606 and a valve rod A.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

Example 1:

referring to fig. 1 and 2, an embodiment of the present invention is an anti-theft self-locking system for fire hydrant, including a housing 1, an opening 2 is provided on the upper end of the housing 1, a valve rod a for opening a water supply valve is provided in the opening 2, wherein the housing 1 is an external housing of the existing fire hydrant, related pipeline facilities are usually provided inside the housing 1 to ensure normal water supply, the opening is an opening 2 on the upper end of the housing 1, the position of the opening 2 corresponds to the valve rod, so that a user can insert a wrench corresponding to the valve rod through the opening 2, and the water supply valve inside the housing 1 is opened by rotating the valve rod.

Above-mentioned opening 2 is equipped with shielding cover 4 for by shielding cover 4 switch opening 2, wherein, the form of opening 2 can be circular or square, and its shielding cover 4 size and opening 2 adaptation shelter from opening 2 through shielding cover 4, and the valve pole is rotated through opening 2 to the prevention unauthorized personnel utilization spanner to steal the water source.

A locking mechanism 5 is arranged on one side of the shell 1 and used for limiting the movement of the shielding cover 4 by the locking mechanism 5, a card reader 7 is arranged on the outer side of the shell 1, the card reader 7 is electrically connected with the locking mechanism 5, the card reader 7 controls the start and stop of the locking mechanism 5 and is used for data connection between the card reader 7 and a monitoring terminal; the card reader 7 is an existing wireless card reader, corresponding user card information is read through the card reader 7, a user inserts a corresponding identity card into the card reader 7, the card reader 7 controls the locking mechanism 5 to be powered on for data connection between the card reader 7 and a monitoring terminal, the monitoring terminal is terminal equipment universal to existing electronic monitoring equipment, and the monitoring terminal is arranged near the card reader 7 so as to collect working information of nearby fire hydrants.

Example 2:

based on the above embodiment, referring to fig. 1, the embodiment is an embodiment of a locking mode of the shielding cover 4, the locking mechanism 5 is an electric control lock, and is used for unlocking the shielding cover 4 by electrifying the electric control lock, wherein the electric control lock may be zns7 series electric control locks with feedback, and the lock catch is bounced off and releases the shielding cover 4 by electrifying the electric control lock.

The shielding cover 4 is provided with a limiting lock 14 in a downward placing mode, the limiting lock 14 is electrically connected with the card reader 7, the lower end of the shielding cover 4 is provided with a limiting groove 401 matched with the limiting lock 14, the shielding cover 4 is released after the limiting lock 14 is powered on, and the shielding cover is delayed to be disconnected after the card reader 7 is powered on the limiting lock 14.

Wherein spacing lock 14 and electric control lock all control the circular telegram opportunity through the ware 7 of punching the card, can adopt delay control to the staff of being convenient for is according to operating specification, after opening shielding cover 4, shielding cover 4 is restricted by spacing lock 14 and spacing groove 401.

Further, an operating handle 402 is arranged above the shielding cover 4, the operating handle 402 extends out of the opening 2 and is used for being moved in the opening 2 by the operating handle 402, after the shielding cover 4 is released by the electric control lock through the operating handle 402, a worker drives the shielding cover 4 to move to an opening position through the operating handle 402, and then the shielding cover 4 is limited by the limiting lock 14 and the limiting groove 401.

In order to facilitate the automatic resetting of the shielding cover 4 after use, the shielding cover 4 is provided at the end thereof with a resetting mechanism 403 for continuously applying a pushing force to the shielding cover 4 by the resetting mechanism 403.

When in operation, the worker swipes the card for the second time to the card reader 7, the card reader 7 energizes the limit lock 14 and the electric control lock again,

at this time, the limit lock 14 is separated from the limit groove 401, the shielding cover 4 loses the limit constraint, the shielding cover 4 is reset under the action of the reset mechanism 403, and the shielding cover 4 is clamped into the electric control lock to complete locking.

It should be noted that the electronic control lock supports manual unlocking by a key under special conditions, so that the matching of the limit lock 14 and the limit groove 401 can prevent the shielding cover 4 from shaking randomly in principle, and the shielding cover 4 is prevented from influencing the water taking operation of workers; its limit lock 14 also supports the mechanical release of the key from a security point of view.

Example 3:

based on the above embodiment, referring to fig. 2, this embodiment is an embodiment of another locking manner of the shielding cover 4, the locking mechanism 5 is a push-pull electromagnet, wherein the locking mechanism 5 is an existing push-pull electromagnet, a draw bar of the push-pull electromagnet is in an extended state when not powered, and the draw bar is in a retracted state after the push-pull electromagnet is powered.

A push-out mechanism 6 is arranged on one side of the locking mechanism 5, a telescopic rod of the push-pull electromagnet is connected with the head end of the push-out mechanism 6, the tail end of the push-out mechanism 6 is connected with the shielding cover 4, and the shielding cover 4 is controlled to open and close by the push-pull electromagnet.

Because the push-pull electromagnet adopts a part which works in a long-distance suction manner, in order to ensure the stability of the suction, the telescopic distance of the traction rod of the locking mechanism 5 cannot reach the moving distance required by the opening and closing of the shielding cover 4, and the function of controlling the large stroke of the shielding cover 4 by the small stroke of the locking mechanism 5 is realized by the push-out mechanism 6.

Specifically, when the locking mechanism 5 is not powered on, the movable iron core and the static iron core of the locking mechanism 5 are not attracted, and at the moment, the movable iron core keeps a certain distance from the static iron core due to the action of a spring, so that a traction rod of the locking mechanism 5 is in a push-out state, and the push-out mechanism 6 pushes the shielding cover 4 to move forwards. When the locking mechanism 5 is powered on, the movable iron core and the static iron core are attracted for a long distance, so that the traction rod of the locking mechanism 5 is contracted, and the shielding cover 4 is pulled to move backwards through the push-out mechanism 6.

The two ends of the opening 2 are provided with guide rails 8, the two ends of the shielding cover 4 extend into the guide rails 8, the guide rails 8 can be U-shaped metal strips, the two ends of the shielding cover 4 extend into the guide rails 8, and the moving path of the shielding cover 4 is ensured through the guide rails 8, so that the moving stability of the shielding cover 4 is improved. It should be noted that, in order to reduce the friction between the shielding cover 4 and the guide rail 8, a sliding block may be disposed in the guide rail 8, and the sliding block is connected to the shielding cover 4, so as to realize the sliding of the shielding cover 4 on the guide rail.

Example 4:

on the basis of above-mentioned embodiment 3, refer to fig. 3 again, another embodiment of the utility model is that, above-mentioned ejecting mechanism 6 includes first rocker 601 and second rocker 602, and locking mechanism 5 is connected to above-mentioned first rocker 601, and above-mentioned second rocker 602 is connected and is sheltered from lid 4, is equipped with lever 603 between above-mentioned first rocker 601 and the second rocker 602, and above-mentioned first rocker 601 and second rocker 602 are connected the lever 603 both ends respectively, are pushed and pulled lever 603 by first rocker 601, are driven the second rocker 602 by lever 603 and move.

The first rocker 601 is connected with a traction rod of the push-pull electromagnet, the traction rod extends or contracts to drive the first rocker 601 to move, and the first rocker 601 pushes or pulls the lever 603.

The lever 603 is provided with a rotating shaft, and the distance between the first rocking bar 601 and the rotating shaft is smaller than the distance between the second rocking bar 602 and the rotating shaft, so that the small-range distance movement of the first rocking bar 601 can drive the large-range distance movement of the second rocking bar 602.

Furthermore, in order to ensure that the second rocker 602 moves in the horizontal direction, a limit nut 604 is disposed at an end of the second rocker 602, and a bar-shaped hole 605 corresponding to the limit nut 604 is disposed on the lever 603, and the limit nut 604 moves in the bar-shaped hole 605.

The second rocking bar 602 is movably connected to the lever 603 through the limiting nut 604, and when the lever 603 swings, the lever 603 pushes or pulls the limiting nut 604, so that the second rocking bar 602 can move horizontally while the limiting nut 604 moves in the strip-shaped hole 605.

Further, referring to fig. 4, in order to reduce the risk of the second rocking bar 602 rocking, the housing 1 is provided with guide wheels 13, the guide wheels 13 are located at the upper and lower ends of the second rocking bar 602, and the second rocking bar 602 is provided with a guide groove 606 adapted to the guide wheels 13.

Through two guide pulleys 13 centre gripping second rocker 602, through guide slot 606 and guide pulley 13 cooperation, avoid second rocker 602 to appear rocking at the removal in-process, effectively guarantee to shelter from the stable removal of lid 4.

Example 5:

based on the basis of any of the above embodiments, in order to ensure normal water intake in an emergency, and meet the premise that the shielding cover 4 can be opened without using the card reader 7, one end of the shielding cover 4 is provided with the push block 9, wherein the push block 9 extends outward, the housing 1 is provided with the negative pressure switch device 3 corresponding to the push block 9, and the push block 9 is abutted by the negative pressure switch device 3. The negative pressure switch device 3 is manually opened, so that the negative pressure switch device 3 can generate certain thrust to forcibly push the push block 9, and the shielding cover 4 is opened. It should be noted that the fire hydrant may be equipped with an existing fire alarm device and be linked with the negative pressure switch device 3, that is, when the negative pressure switch device 3 is activated, fire alarm is performed at the same time.

Further, referring to fig. 5, the negative pressure switch device 3 includes a cavity 301, wherein the cavity 301 is a metal pipe, an air valve assembly 302 is disposed at a rear end of the cavity 301, a piston 303 is disposed at a middle portion of the cavity 301, a sealed space is formed in the cavity 301 by the air valve assembly 302 and the piston 303, the air valve assembly 302 controls an air flow state of the sealed space, the air valve assembly 302 makes the interior of the cavity 301 be a negative pressure, and when the cavity 301 is subjected to the negative pressure, an adsorption force is formed on the piston 303, so that the piston 303 moves toward the air valve assembly 302.

In order to restrict the movement of the piston 303, an inner protrusion 304 is disposed in the cavity 301, and a return spring 305 is disposed between the inner protrusion 304 and the piston 303, i.e. when the piston 303 is at the maximum stroke, the piston 303 abuts against the inner protrusion 304, thereby effectively preventing the piston 303 from contacting the air valve assembly 302.

The front end of the piston 303 is provided with a push rod 306, the front end of the push rod 306 extends out of the cavity 301, air is injected into the cavity 301 through the air valve assembly 302, the push rod 306 is abutted against the push block 9, and the return spring 305 applies pushing force to the piston 303.

When the cavity 301 is at negative pressure, the piston 303 and the push rod 306 move backwards by the return spring 305 between the inner convex part 304 and the piston 303, and the return spring 305 is extruded at the moment; when the air valve assembly 302 makes the cavity 301 under normal air pressure, the return spring 305 pushes the piston 303 to move forward, the push rod 306 extends out of the cavity 301 to contact the push block 9, and pushes the push block 9 to move, so that the shielding cover 4 moves to leak out of the opening 2.

Furthermore, in order to prevent the piston 303 from being pushed out of the cavity 301 by the return spring 305, the end of the cavity 301 is provided with a stopper 10, and the stopper 10 limits the moving path of the piston 303; the air valve assembly 302 includes a check valve 11 and a check valve 12, and the check valve 12 injects air into the cavity 301 to make the interior of the cavity 301 positive in pressure, and the check valve 11 withdraws air from the cavity 301 to make the interior of the cavity 301 negative in pressure.

Specifically, the air valve assembly 302 is two channels installed on the pipe plug, and the channel is respectively installed with a check valve 11 and a stop valve 12, and both the check valve 11 and the stop valve 12 are existing commercial products, wherein the check valve 11 only allows the air flow to be drawn out from the cavity 301. Wherein the stop valve 12 is an existing valve and is opened by manually rotating a valve disc, and the operation is easy.

The air valve assembly 302 is exposed out of the outer wall of the shell 1, an operation box is additionally arranged outside the shell 1, pedestrians are prevented from touching the operation box, and the operation box can be made of glass so as to be broken in emergency.

Reference throughout this specification to "one embodiment," "another embodiment," "an embodiment," "a preferred embodiment," or the like, means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment described generally in this application. The appearances of the same phrase in various places in the specification are not necessarily all referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with any embodiment, it is submitted that it is within the scope of the invention to effect such feature, structure, or characteristic in connection with other embodiments.

Although the invention has been described herein with reference to a number of illustrative embodiments thereof, it should be understood that numerous other modifications and embodiments can be devised by those skilled in the art that will fall within the spirit and scope of the principles of this invention. More specifically, various variations and modifications are possible in the component parts and/or arrangements of the subject combination arrangement within the scope of the disclosure, the drawings and the appended claims. In addition to variations and modifications in the component parts and/or arrangements, other uses will also be apparent to those skilled in the art.

Claims

1. The utility model provides a theftproof auto-lock system for fire hydrant, includes casing (1), casing (1) upper end is equipped with opening (2), be equipped with the valve pole of opening water supply valve door in opening (2), its characterized in that: be equipped with on opening (2) and shelter from lid (4) for by sheltering from lid (4) switch opening (2), casing (1) one side is equipped with locking mechanism (5) for shelter from lid (4) removal by locking mechanism (5) restriction, the casing (1) outside is equipped with the ware of punching the card (7), the ware of punching the card (7) is connected with locking mechanism (5) electricity, by the ware of punching the card (7) control the opening of locking mechanism (5) is stopped, be used for by the ware of punching the card (7) and monitor terminal data connection.

2. The anti-theft self-locking system for fire hydrants according to claim 1, wherein: the locking mechanism (5) is an electric control lock and is used for unlocking the shielding cover (4) by electrifying the electric control lock, the shielding cover (4) is placed with a limiting lock (14), the limiting lock (14) is electrically connected with the card swiping device (7), the lower end of the shielding cover (4) is provided with a limiting groove (401) matched with the limiting lock (14) and used for releasing the shielding cover (4) after the limiting lock (14) is electrified and delaying disconnection after the card swiping device (7) is electrified to the limiting lock (14).

3. The anti-theft self-locking system for fire hydrants according to claim 2, wherein: an operating handle (402) is arranged above the shielding cover (4), the operating handle (402) extends out of the opening (2) and is used for being moved in the opening (2) by the operating handle (402), and the tail end of the shielding cover (4) is provided with a resetting mechanism (403) which is used for continuously applying pushing force to the shielding cover (4) by the resetting mechanism (403).

4. The anti-theft self-locking system for fire hydrants according to claim 1, wherein: the locking mechanism (5) is a push-pull electromagnet, a push-out mechanism (6) is arranged on one side of the locking mechanism (5), a telescopic rod of the push-pull electromagnet is connected with the head end of the push-out mechanism (6), the tail end of the push-out mechanism (6) is connected with a shielding cover (4), and the shielding cover (4) is controlled to be opened and closed by the push-pull electromagnet; guide rails (8) are arranged at the two ends of the opening (2), and the two ends of the shielding cover (4) extend into the guide rails (8).

5. The anti-theft self-locking system for fire hydrants according to claim 4, wherein: the push-out mechanism (6) comprises a first rocker (601) and a second rocker (602), the first rocker (601) is connected with the push-pull electromagnet, the second rocker (602) is connected with the shielding cover (4), a lever (603) is arranged between the first rocker (601) and the second rocker (602), the first rocker (601) and the second rocker (602) are respectively connected with two ends of the lever (603), the lever (603) is pushed and pulled by the first rocker (601), and the lever (603) drives the second rocker (602) to move.

6. The anti-theft self-locking system for fire hydrants according to claim 5, wherein: the end part of the second rocker (602) is provided with a limit nut (604), the lever (603) is provided with a strip-shaped hole (605) corresponding to the limit nut (604), and the limit nut (604) moves in the strip-shaped hole (605).

7. The anti-theft self-locking system for fire hydrants according to claim 6, wherein: the guide wheel (13) is arranged in the shell (1), the guide wheel (13) is located at the upper end and the lower end of the second rocker (602), and the second rocker (602) is provided with a guide groove (606) matched with the guide wheel (13).

8. The anti-theft self-locking system for fire hydrants according to claim 1, wherein: one end of the shielding cover (4) is provided with a push block (9), a negative pressure switch device (3) corresponding to the push block (9) is arranged in the shell (1), and the negative pressure switch device (3) is abutted against the push block (9).

9. The anti-theft self-locking system for fire hydrants according to claim 8, wherein: negative pressure switch device (3) are including cavity (301), cavity (301) rear end is equipped with air valve subassembly (302), cavity (301) middle part is equipped with piston (303), makes cavity (301) inside be the negative pressure by air valve subassembly (302), be equipped with interior convex part (304) in cavity (301), be equipped with reset spring (305) between interior convex part (304) and piston (303), piston (303) front end is equipped with push rod (306), stretches out from cavity (301) by push rod (306) front end, injects the air into cavity (301) by air valve subassembly (302) and makes push rod (306) conflict ejector pad (9), applys thrust to piston (303) by reset spring (305).

10. The anti-theft self-locking system for fire hydrants according to claim 9, wherein: cavity (301) end is equipped with stopper (10), by stopper (10) restriction piston (303) moving path, air valve subassembly (302) are including check valve (11) and stop valve (12), by stop valve (12) are injected into the air to cavity (301) and are made the inside malleation of cavity (301), are taken out the air in cavity (301) by check valve (11) and are made the inside negative pressure of cavity (301).