CN114419827B

CN114419827B - DC power supply alarm device

Info

Publication number: CN114419827B
Application number: CN202210274388.9A
Authority: CN
Inventors: 李福忠; 周承; 谭新强; 王晶磊
Original assignee: Shandong Sanjing Lighting Science & Technology Co ltd
Current assignee: Shandong Sanjing Lighting Science & Technology Co ltd
Priority date: 2022-03-21
Filing date: 2022-03-21
Publication date: 2022-07-12
Anticipated expiration: 2042-03-21
Also published as: CN114419827A

Abstract

The invention is suitable for the technical field of alarms, and provides a direct-current power supply alarm device, which comprises: a housing and a labyrinth cover; the casing is provided with a fixed interface, a detection circuit board is fixedly connected inside the casing, a light source and a light source receiver are arranged on the detection circuit board, a partition plate is arranged between the light source and the light source receiver, the casing is provided with a mounting hole, the labyrinth cover is inserted into the mounting hole, and the labyrinth cover can cover the light source and the light source receiver; the outer side of the upper end of the labyrinth cover is provided with an annular clamping groove, and the outer side of the lower end of the labyrinth cover is provided with a filter screen mounting groove; the casing corresponds ring groove is equipped with clamping mechanism, clamping mechanism can with the labyrinth lid is fixed. Therefore, the filter screen and the labyrinth cover are integrally disassembled and assembled through the modular design of the filter screen and the labyrinth cover, the operation is simple and rapid, meanwhile, the rotary disassembling mode is changed into the pressing type disassembling mode, the operation is more convenient, and the rotating direction does not need to be distinguished.

Description

DC power supply alarm device

Technical Field

The invention relates to the technical field of alarms, in particular to a direct-current power supply alarm device.

Background

With the increase of fire and electricity consumption in modern hotels, restaurants, entertainment places, families and the like, the frequency of various fires is higher and higher. In order to enable early detection and avoid serious life and property losses, fire alarm devices are generally equipped. The fire alarm utilizes a high-sensitivity detection element arranged in the fire alarm to capture abnormal changes such as temperature, gas content and the like in the air and send out an alarm signal. The fire alarm is generally arranged on a ceiling, the early warning range of a single alarm is limited, a large number of alarms are often arranged in one building, in order to reduce the wiring difficulty, a battery is generally adopted to provide a direct-current power supply, and signals are transmitted in a wireless transmission mode.

After the fire alarm is used for a long time, a large amount of dust and oil smoke can be adsorbed on a filter screen and a labyrinth cover in the fire alarm, the filter screen is blocked, and the detection of the fire alarm is influenced. There are two methods for clearing the fire alarm: after being disassembled, the cleaning or self-cleaning device is cleaned or self-cleaned, and in practical use, the self-cleaning effect is not ideal, the structure is complex, and the cost and the failure rate are high. Remove abluent mode after the dismantlement and can effectual clearance filter screen and the dust that the labyrinth covered, clean effectual, nevertheless need dismantle the shell of fire alarm when dismantling, demolish the back to the filter screen, just can demolish the labyrinth lid again, and is more arduous, workman work efficiency is low. The existing fire alarm is generally fixed in a rotary clamping mode, but when the fire alarm is disassembled at high altitude, the rotating direction is easy to be confused, so that the workers can perform arm suspension operation for a long time, and the difficulty and the danger of the high altitude operation are increased.

In view of the above, the prior art is obviously inconvenient and disadvantageous in practical use, and needs to be improved.

Disclosure of Invention

In view of the above-mentioned drawbacks, an object of the present invention is to provide a dc power supply alarm device, which realizes the overall removal and installation of a filter screen and a labyrinth cover by modular design of the filter screen and the labyrinth cover, and has simple and quick operation, and changes the rotary removal mode into a push-type removal mode, so that the operation is more convenient, the rotation direction does not need to be distinguished, the labyrinth cover can be removed by the push-type removal mode, the operation difficulty of high-altitude operation is reduced, and the safety factor of high-altitude operation is improved.

In order to achieve the above object, the present invention provides a dc power supply alarm device, including: a housing and a labyrinth cover; the casing is provided with a fixed interface, a detection circuit board is fixedly connected inside the casing, a light source and a light source receiver are arranged on the detection circuit board, a partition plate is arranged between the light source and the light source receiver, the casing is provided with a mounting hole, the labyrinth cover is inserted into the mounting hole, and the labyrinth cover can cover the light source and the light source receiver;

the outer side of the upper end of the labyrinth cover is provided with an annular clamping groove, the outer side of the lower end of the labyrinth cover is provided with a filter screen mounting groove, a filter screen is arranged in the filter screen mounting groove, the inner side of the filter screen mounting groove is provided with a labyrinth structure, and the labyrinth structure is used for preventing light rays from entering the labyrinth cover;

the shell is provided with a clamping mechanism corresponding to the annular clamping groove, and the clamping mechanism can fix the labyrinth cover;

the clamping mechanism comprises: the rotary shaft is provided with a short rod perpendicular to the axis direction, one end of the connecting rod is hinged to the short rod, the other end of the connecting rod is hinged to one end of the clamping plate, the rotary shaft is rotatably connected with the shell, and the rotary shaft can drive the clamping plate to be clamped with the annular clamping groove.

According to the direct current supply alarm device, the other end of the clamping plate is hinged with the shell.

According to the direct-current power supply alarm device, the number of the rotating shafts is two, the number of the connecting rods is two, the two rotating shafts are symmetrically arranged on two sides of the mounting hole and correspond to the connecting rods one to one, and two ends of the clamping plate are respectively hinged to the other ends of the two connecting rods.

According to the direct-current power supply alarm device, the number of the rotating shafts is two, the number of the connecting rods is four, the number of the clamping plates is two, the two rotating shafts are symmetrically arranged on two sides of the mounting hole, two short rods which are perpendicular to the axial direction and are symmetrically arranged are arranged on one rotating shaft, each short rod is hinged to one end of one connecting rod, the two clamping plates are symmetrically arranged on two sides of a connecting line of the two rotating shafts, and two ends of each clamping plate are hinged to one connecting rod on different rotating shafts respectively.

According to the direct current power supply alarm device, a torsion spring is arranged between the rotating shaft and the shell.

According to the direct current supply alarm device, the upper side wall and the lower side wall of the annular clamping groove and the outer wall of the upper end of the labyrinth cover are respectively provided with a chamfer angle structure.

According to the direct-current power supply alarm device, the relative heights of the annular clamping groove and the clamping plate can be adaptively set, so that when the clamping plate is clamped in the annular clamping groove, the upper surface of the clamping plate abuts against the upper side wall of the annular clamping groove.

According to the direct-current power supply alarm device, the clamping mechanism further comprises a switching rod, the switching rod is connected with the shell in a sliding mode, a gear structure is arranged on the rotating shaft, and a rack structure is arranged on the switching rod corresponding to the gear structure.

According to the direct current supply alarm device, the shell is further provided with a buffering part, the buffering part is arranged corresponding to the filter screen installation groove, the buffering part comprises an elastic piece, the elastic piece is located on the outer side of the filter screen, and the elastic piece is interfered with the moving track of the labyrinth cover.

According to the direct current power supply alarm device, the elastic piece is a steel ball, and a spring is arranged between the steel ball and the shell.

The invention provides a direct current supply alarm device, which comprises: a housing and a labyrinth cover; the casing is provided with a fixed interface, a detection circuit board is fixedly connected inside the casing, a light source and a light source receiver are arranged on the detection circuit board, a partition plate is arranged between the light source and the light source receiver, the casing is provided with a mounting hole, a labyrinth cover is inserted into the mounting hole, and the labyrinth cover can cover the light source and the light source receiver; the outer side of the upper end of the labyrinth cover is provided with an annular clamping groove, the outer side of the lower end of the labyrinth cover is provided with a filter screen mounting groove, a filter screen is arranged in the filter screen mounting groove, the inner side of the filter screen mounting groove is provided with a labyrinth structure, and the labyrinth structure is used for preventing light rays from entering the labyrinth cover; the shell is provided with a clamping mechanism corresponding to the annular clamping groove, and the clamping mechanism can fix the labyrinth cover; according to the invention, the labyrinth cover is clamped in the shell, and the labyrinth cover is rapidly disassembled by using the clamping mechanism under the condition of not disassembling the machine, so that the labyrinth cover is more convenient to install, the difficulty of high-altitude operation is reduced, the structure is simple, the use is convenient, and the manufacturing cost is low; the rotating disassembly mode is changed into the pressing disassembly mode, the operation is more convenient, the rotating direction does not need to be distinguished, the labyrinth cover can be disassembled by using the pressing mode, the design of the man-machine mechanics is met, and the safety coefficient of the high-altitude operation is improved; meanwhile, the buffering part is additionally arranged, so that the labyrinth cover is prevented from falling from a high position when the labyrinth cover is disassembled, and the safety coefficient of operation is improved; utilize cardboard and ring groove's relative difference in height simultaneously for the cardboard upwards extrudees ring groove, increases labyrinth lid and detection circuit board's leakproofness, and increases the stability of being connected of labyrinth lid and casing, prevents to take place to become flexible between labyrinth lid and the casing, influences the normal work of alarm.

Drawings

FIG. 1 is a schematic structural view of the present invention; FIG. 2 is a schematic structural view of the labyrinth cover of the present invention; FIG. 3 is a schematic structural view of a first embodiment of the clamping mechanism of the present invention; FIG. 4 is a schematic structural view of a second embodiment of the clamping mechanism of the present invention; FIG. 5 is a schematic structural view of a third embodiment of the clamping mechanism of the present invention; FIG. 6 is a structural view of a third embodiment of the latch mechanism of the present invention in an operating state; FIG. 7 is a structural schematic view of a first installation state of the present invention; FIG. 8 is a structural schematic view of a second installation state of the present invention; FIG. 9 is a schematic view of a first state of detail A of FIG. 8; FIG. 10 is a schematic view of a second state of detail A in FIG. 8; in the figure, 1-shell, 11-detection circuit board, 12-fixed interface, 13-insect-proof net, 2-labyrinth cover, 21-annular clamping groove, 211-chamfer structure, 22-filter screen mounting groove, 23-filter screen, 3-clamping mechanism, 31-rotating shaft, 32-connecting rod, 33-clamping plate, 34-switching rod and 4-elastic element.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further 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.

Referring to fig. 1, the present invention provides a dc power supply alarm device. This DC power supply alarm device includes: casing 1 and labyrinth lid 2, casing 1 is equipped with fixed interface 12 and detection circuit board 11, fixed interface 12 is used for with casing 1 fixed connection on the ceiling, detection circuit board 11 fixed connection is in casing 1, be equipped with light source and light source receiver on the detection circuit board 11, be equipped with the baffle between light source and the light source receiver, the baffle separates light source and light source receiver, under the normality, the light source receiver can't receive the light signal of light source transmission, when there is a certain amount of smog in labyrinth lid 2, the light source receiver can receive the light signal of smog scattering, this alarm device reports to the police. Be equipped with the mounting hole on

casing

1, 2 grafting mounting holes of labyrinth lid, labyrinth lid 2 can cover light source, light source receiver and baffle, arranges light source and light source receiver in the darkroom, and labyrinth lid 2's upper end is equipped with flexible sealing member, can closely laminate labyrinth lid 2 in the below of detecting circuit board 11, prevents the light leak, and flexible sealing member can be for the impervious insulating elastic substance such as rubber pad.

Referring to fig. 2, labyrinth lid 2's the upper end outside is equipped with ring groove 21, and labyrinth lid 2's the lower extreme outside is equipped with filter screen mounting groove 22, is equipped with filter screen 23 in the filter screen mounting groove 22, and filter screen mounting groove 22's inboard is equipped with labyrinth structure, and labyrinth structure is used for blockking in light gets into labyrinth lid 2, and labyrinth lid 2's upper end is opened, and labyrinth lid 2's lower extreme seals, and labyrinth lid 2's upper end cup joints on detection circuit board 11.

The casing 1 is equipped with latch mechanism 3 corresponding to ring groove 21, and latch mechanism 3 can fix labyrinth lid 2 in casing 1.

Referring to fig. 3, as a preferred embodiment of the present invention, the latch mechanism 3 includes: pivot 31, connecting rod 32 and cardboard 33, pivot 31 rotates and connects casing 1, be equipped with torsional spring or spiral spring between pivot 31 and the casing 1, torsional spring or spiral spring provide the power of the 31 rotation of pivot, be equipped with the quarter butt of perpendicular axis direction on the pivot 31, the articulated pivot 31 of quarter butt is passed through to the one end of connecting rod 32, the articulated one end of cardboard 33 of the other end of connecting rod 32, the articulated casing 1 of the other end of cardboard 33, joint in ring slot 21 under the cardboard 33 normality, when rotating pivot 31, connecting rod 32 drives the cardboard 33 rotatory, rotate out ring slot 21 with cardboard 33, realize the release of labyrinth cover 2.

Referring to fig. 4, as another preferred embodiment of the present invention, the latch mechanism 3 includes: the two rotating shafts 31 are symmetrically arranged on two sides of the mounting hole, the rotating shafts 31 are rotatably connected with the shell 1, a torsion spring or a volute spiral spring is arranged between the rotating shafts 31 and the shell 1 and provides power for the rotating shafts 31 to rotate, short rods perpendicular to the axial direction are arranged on the rotating shafts 31, one ends of the connecting rods 32 are hinged with the rotating shafts 31 through the short rods, one rotating shaft 31 is hinged with one connecting rod 32, two ends of the clamping plate 33 are respectively hinged with the other ends of the two connecting rods 32, and when one rotating shaft 31 rotates, the connecting rods 32 drive the clamping plate 33 to move, and the clamping plate 33 rotates; when the two rotating shafts 31 synchronously rotate in opposite directions, the catch plate 33 moves in a straight line.

Referring to fig. 5, as a third preferred embodiment of the present invention, the latch mechanism 3 includes: two rotating shafts 31, four connecting rods 32 and two clamping plates 33, wherein the two rotating shafts 31 are symmetrically arranged at two sides of the mounting hole, the rotating shafts 31 are rotatably connected with the shell 1, a torsion spring is arranged between the rotating shafts 31 and the shell 1 and provides power for the rotation of the rotating shafts 31, two short rods which are perpendicular to the axial direction and are symmetrically arranged are arranged on the rotating shafts 31, one end of each connecting rod 32 is hinged with the rotating shaft 31 through the short rod, the short rods are in one-to-one correspondence with the connecting rods 32, each short rod is hinged with one end of one connecting rod 32, and one rotating shaft 31 is symmetrically hinged with the two connecting rods 32. for better description, referring to fig. 5, the connecting line of the two rotating shafts 31 is set as a central line, the position above the connecting line is called as the front of the mounting hole, and the position below the connecting line is called as the rear of the mounting hole; two cardboard 33 are located the place ahead of mounting hole and the rear of mounting hole respectively, and the both ends of a cardboard 33 articulate the one end of two connecting rods 32 respectively, and the other end of two connecting rods 32 here articulates respectively on different pivot 31, and two connecting rods 32 are located the place ahead of mounting hole or the rear of mounting hole with this cardboard 33 simultaneously. Referring to fig. 6, when one rotating shaft 31 rotates, two connecting rods 32 hinged to the same rotating shaft 31 drive two clamping plates 33 to move, and the rotating track of the clamping plates 33 is a rotating motion; when the two rotating shafts 31 rotate synchronously, the catch plate 33 moves in a straight line.

Preferably, the clamping plate 33 can be in the shape of a straight bar, and has a simple structure and low manufacturing cost.

Referring to fig. 6, preferably, the shape of the clamping plate 33 can be matched with the shape of the labyrinth cover 2, and the middle part of the clamping plate 33 is provided with an arc-shaped section, so that the volume of the clamping mechanism 3 can be reduced, the volume of the dc power supply alarm device is further reduced, the production cost is reduced, and the subsequent optimization design is facilitated.

Referring to fig. 3 to 6, further, the clamping mechanism 3 further includes a switching rod 34, the switching rod 34 is slidably connected to the housing 1, a rack structure is arranged on the switching rod 34, the rotating shaft 31 is provided with a gear structure, the switching rod 34 is screwed to the rotating shaft 31 through the rack structure and the gear structure, the rotating shaft 31 is driven to rotate through the movement of the switching rod 34, and the clamping plate 33 is clamped to the annular clamping groove 21. Under the normal state, the rotating shaft 31 clamps the clamping plate 33 into the annular clamping groove 21 on the labyrinth cover 2 under the action of the torsion spring, and the switching rod 34 extends to the outer side of the shell 1. When needing to dismantle labyrinth cover 2, press switching lever 34 in to casing 1, drive pivot 31 rotation for cardboard 33 breaks away from the contact with ring channel 21, releases labyrinth cover 2, and labyrinth cover 2 is released after, unclamps switching lever 34, and switching lever 34 resets under the effect of pivot 31, and cardboard 33 resets.

Referring to fig. 7 to 10, further, casing 1 is last still to be equipped with buffering portion, and buffering portion corresponds filter screen mounting groove 22 and sets up, and labyrinth lid 2 whereabouts in-process, buffering portion plays flexible joint's effect, prevents that labyrinth lid 2 from directly dropping to casing 1's outside, takes place the danger that the high altitude falls. Buffer includes elastic component 4, and elastic component 4 is located filter screen 23's the outside, and when labyrinth lid 2 whereabouts, the last lateral wall of filter screen mounting groove 22 falls on elastic component 4, prevents labyrinth lid 2's whereabouts, then the staff utilizes manual mode to pull labyrinth lid 2 downwards for elastic component 4 is out of shape to labyrinth lid 2's the outside, and labyrinth lid 2 is manual slowly takes out under certain damping force effect, convenient operation, factor of safety is high.

Preferably, the elastic part 4 can be a rubber rod or a silica gel rod, the rubber rod and the silica gel rod have certain elasticity, the labyrinth cover 2 can be blocked by the elasticity of the material, and the rubber rod and the silica gel rod deform under the action of manual dragging to take out the labyrinth cover 2.

Preferably, the elastic member 4 is a steel ball, the steel ball is elastically connected with the housing 1, the steel ball slightly protrudes out of the mounting hole, in a normal state, the steel ball interferes with the moving track of the labyrinth cover 2, the steel ball is close to but does not contact with the filter screen 23, so that the upper side wall of the filter screen mounting groove 22 is hung on the steel ball in the falling process, then the labyrinth cover 2 is manually dragged, the steel ball is compressed into the housing 1, and the labyrinth cover 2 is manually taken out.

Further, ring slot 21's upper and lower lateral wall and labyrinth lid 2's upper end outer wall all are equipped with chamfer structure 211, make things convenient for elastic component 4 when through ring slot 21, and smooth transition prevents that 4 joints of elastic component from in ring slot 21, causing labyrinth lid 2 can't dismantle. The chamfer 211 serves as a guide when the card 33 engages the ring slot 21.

Further, ring slot 21 can carry out the adaptability setting with the relative height of cardboard 33, when making cardboard 33 joint to ring slot 21 in, the last lateral wall of upper surface butt ring slot 21 of cardboard 33, cardboard 33 applys ascending extrusion force to

ring slot

21, 2 extrusion with labyrinth cover are on detecting circuit board 11, the flexible sealing member of labyrinth cover 2 tops is extruded and takes place slight deformation simultaneously, increase labyrinth cover 2 and the leakproofness between detecting circuit board 11, labyrinth cover 2's fixed more reliable, it is not hard up to prevent to produce between labyrinth cover 2 and the casing 1.

Further, an insect-proof net 13 is arranged below the shell 1, the diameter of the meshes of the insect-proof net 13 is larger than that of the meshes of the filter screen 23, the insect-proof net 13 can block insects outside, especially flies, mosquitoes and the like, and the dust attachment amount of the filter screen 23 is reduced.

Referring to fig. 3 to 10, when the dc power supply alarm device needs cleaning, the switching rod 34 is pressed by a hand, the switching rod 34 drives the rotating shaft 31 to rotate, the rotating shaft 31 drives the connecting rod 32 to rotate, the connecting rod 32 drives the clamping plate 33 to move, the clamping plate 33 moves out of the circular clamping groove 21, the labyrinth cover 2 falls down by self weight, when the upper side wall of the filter screen mounting groove 22 contacts the elastic element 4, the elastic element 4 blocks the labyrinth cover 2 and hooks the labyrinth cover, at this time, the lower end of the labyrinth cover 2 is manually pulled, and the labyrinth cover 2 moves down by overcoming the damping force of the elastic element 4 until the labyrinth cover 2 is completely separated from the housing 1. Then, the new labyrinth cover 2 is operated reversely, the labyrinth cover 2 is pushed upwards, the labyrinth cover 2 overcomes the damping force of the elastic part 4 to continue rising, the upper part of the labyrinth cover 2 is provided with a chamfer structure 211, along with the rising of the labyrinth cover 2, the chamfer structure 211 outwards expands the clamping plate 33, the rotating shaft 31 rotates, the torsion spring applies torsion to the rotating shaft 31, when the annular clamping groove 21 of the labyrinth cover 2 moves to the clamping plate 33, the clamping plate 33 is clamped in the annular clamping groove 21 under the action of the torsion of the rotating shaft 31 and under the guiding action of the chamfer structure 211, the upper surface of the clamping plate 33 is abutted against the upper side wall of the annular clamping groove 21, the labyrinth cover 2 is upwardly abutted against the lower part of the detection circuit board 11, the fixing of the labyrinth cover 2 is realized, and the installation of the new labyrinth cover 2 is completed. The labyrinth cover 2 which is replaced is subjected to uniform cleaning treatment, and waits for the next replacement.

In summary, the present invention provides a dc power supply alarm device, including: a housing and a labyrinth cover; the casing is provided with a fixed interface, a detection circuit board is fixedly connected inside the casing, a light source and a light source receiver are arranged on the detection circuit board, a partition plate is arranged between the light source and the light source receiver, the casing is provided with a mounting hole, and a labyrinth cover is inserted into the mounting hole and can cover the light source and the light source receiver; the outer side of the upper end of the labyrinth cover is provided with an annular clamping groove, the outer side of the lower end of the labyrinth cover is provided with a filter screen mounting groove, a filter screen is arranged in the filter screen mounting groove, the inner side of the filter screen mounting groove is provided with a labyrinth structure, and the labyrinth structure is used for preventing light rays from entering the labyrinth cover; the shell is provided with a clamping mechanism corresponding to the annular clamping groove, and the clamping mechanism can fix the labyrinth cover; according to the invention, the labyrinth cover is clamped in the shell, and the labyrinth cover is rapidly disassembled by using the clamping mechanism under the condition of not disassembling the machine, so that the labyrinth cover is more convenient to install, the difficulty of high-altitude operation is reduced, the structure is simple, the use is convenient, and the manufacturing cost is low; the rotating disassembly mode is changed into the pressing disassembly mode, the operation is more convenient, the rotating direction does not need to be distinguished, the labyrinth cover can be disassembled by using the pressing mode, the design of the man-machine mechanics is met, and the safety coefficient of the high-altitude operation is improved; meanwhile, the buffering part is additionally arranged, so that the labyrinth cover is prevented from falling from a high position when the labyrinth cover is disassembled, and the safety coefficient of operation is improved; utilize cardboard and ring groove's relative difference in height simultaneously for the cardboard upwards extrudees ring groove, increases labyrinth lid and detection circuit board's leakproofness, and increases the stability of being connected of labyrinth lid and casing, prevents to take place to become flexible between labyrinth lid and the casing, influences the normal work of alarm.

In the description of the present invention, it is to be understood that the terms "upper", "lower", "left", "right", and the like indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience in describing the present invention and simplifying the description, but do not indicate or imply that the referred device or element must have a specific orientation, be constructed in a specific orientation, and be operated, and thus, should not be construed as limiting the present invention.

The present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof, and it should be understood that various changes and modifications can be effected therein by one skilled in the art without departing from the spirit and scope of the invention as defined in the appended claims.

Claims

1. A dc powered alarm device, comprising: a housing and a labyrinth cover; the casing is provided with a fixed interface, a detection circuit board is fixedly connected inside the casing, a light source and a light source receiver are arranged on the detection circuit board, a partition plate is arranged between the light source and the light source receiver, the casing is provided with a mounting hole, the labyrinth cover is inserted into the mounting hole, and the labyrinth cover can cover the light source and the light source receiver;

the clamping mechanism comprises: the rotary shaft is provided with a short rod perpendicular to the axis direction, one end of the connecting rod is hinged to the short rod, the other end of the connecting rod is hinged to one end of the clamping plate, the rotary shaft is rotatably connected with the casing, the rotary shaft can drive the clamping plate to be clamped with the annular clamping groove, and the other end of the clamping plate is hinged to the casing.

2. The direct-current power supply alarm device according to claim 1, wherein the number of the rotating shafts is two, the number of the connecting rods is two, the two rotating shafts are symmetrically arranged on two sides of the mounting hole, the rotating shafts correspond to the connecting rods one to one, and two ends of the clamping plate are respectively hinged to the other ends of the two connecting rods.

3. The direct current supply alarm device according to claim 1, wherein the number of the rotating shafts is two, the number of the connecting rods is four, the number of the clamping plates is two, the two rotating shafts are symmetrically arranged on two sides of the mounting hole, two short rods which are perpendicular to the axial direction and symmetrically arranged are arranged on one rotating shaft, each short rod is hinged to one end of one connecting rod, the two clamping plates are symmetrically arranged on two sides of a connecting line of the two rotating shafts, and two ends of each clamping plate are respectively hinged to one connecting rod on different rotating shafts.

4. The direct current power supply alarm device according to any one of claims 2-3, wherein a torsion spring is arranged between the rotating shaft and the housing.

5. The direct current supply alarm device according to claim 4, wherein the upper and lower side walls of the ring-shaped clamping groove and the outer wall of the upper end of the labyrinth cover are provided with chamfer structures.

6. The direct current supply alarm device according to claim 5, wherein the relative heights of the ring slot and the clamping plate can be adaptively set, so that when the clamping plate is clamped in the ring slot, the upper surface of the clamping plate abuts against the upper side wall of the ring slot.

7. The alarm device of claim 6, wherein the latch mechanism further comprises a switch rod, the switch rod is slidably connected to the housing, the shaft is provided with a gear structure, and the switch rod is provided with a rack structure corresponding to the gear structure.

8. The direct current supply alarm device according to claim 7, wherein the housing is further provided with a buffer portion, the buffer portion is disposed corresponding to the filter screen mounting groove, the buffer portion includes an elastic member, the elastic member is located outside the filter screen, and the elastic member interferes with a moving track of the labyrinth cover.

9. The dc power supply alarm device of claim 8, wherein the elastic member is a steel ball, and a spring is disposed between the steel ball and the housing.