CN220563382U - Cover plate pressing mechanism and cabin top manhole sealing device - Google Patents

Abstract

The cover plate pressing mechanism comprises a pressing component and a locking component; the compression assembly comprises an electric push rod vertically arranged above the cover plate, a shell of the electric push rod is fixed on the cover plate through a bracket, a telescopic rod of the electric push rod is respectively hinged with a plurality of slide bar type lock tongues through a plurality of connecting rods, one end of the slide bar type lock tongue, which is far away from the connecting rods, is provided with a wedge-shaped head, and a guide rail for the slide bar type lock tongue to slide is arranged on the cover plate; the locking assembly comprises locking frames, the number of which is consistent with that of the slide bar type lock bolts, and locking channels for the slide bar type lock bolts to be inserted are formed in the locking frames. According to the utility model, the edge of the cover plate can be simultaneously pressed on the bin top manhole, so that the efficiency of pressing work is improved.

Description

Cover plate pressing mechanism and cabin top manhole sealing device

Technical Field

The utility model relates to the technical field of airtight of storage facilities, in particular to a cover plate pressing mechanism and a bin top manhole airtight device.

Background

The shallow round bin is used as a storage and transfer bin, has lower comprehensive cost than a common silo, higher mechanization degree than a room type bin, and has the advantages of large storage capacity, small occupied area and low operation cost. The top of the shallow circular bin is provided with a channel-manhole for a worker to enter and exit the bin to sample and check grain conditions, at present, the shallow circular bin mostly adopts an escalator-type manhole, namely the manhole is a rectangular hole with larger size, so that the worker can conveniently carry things into and out of the bin, and the sealing device is used for sealing to ensure the sealing performance of the shallow circular bin.

In the prior art, the manhole extends upwards to form an extension part, the sealing device is connected with the extension part, the sealing device can cover the cover plate of the manhole, the rubber mat is often bonded on the bottom surface of the cover plate, and when the cover plate covers the orifice, the rubber mat is used for sealing the manhole.

In practical application, a compressing unit is arranged between the manhole and the cover plate to improve the sealing effect of the manhole, as shown in fig. 10, the compressing unit 8 comprises a rotating part with the bottom end rotationally connected with the cabin top, the top end of the rotating part bends towards the center of the manhole to form a bending part, the bending part rotates to be provided with a compressing rod capable of compressing the cover plate to an upper port of the manhole, and when the compressing rod is rotated to compress the cover plate. However, in order to ensure the sealing effect, the compressing units between the manhole and the cover plate are often arranged in a plurality of groups, and when the compressing operation is performed by using the compressing units, the compressing rods of the compressing units need to be twisted one by one, so that the compressing operation efficiency is limited.

Disclosure of Invention

The utility model aims to provide a cover plate pressing mechanism and a bin top manhole sealing device, so that the edge of a cover plate is pressed on a bin top manhole at the same time, and the pressing efficiency is improved.

In order to solve the technical problems, the utility model adopts the following specific scheme: the cover plate pressing mechanism is used for being covered on the cabin top manhole, an elastic sealing piece is arranged between the cover plate and the cabin top manhole, and the cover plate pressing mechanism comprises a pressing component and a locking component; the compression assembly comprises an electric push rod vertically arranged above the cover plate, a shell of the electric push rod is fixed on the cover plate through a bracket, a telescopic rod of the electric push rod is respectively hinged with a plurality of slide bar type lock tongues through a plurality of connecting rods, one end of the slide bar type lock tongue, which is far away from the connecting rods, is provided with a wedge-shaped head, and a guide rail for the slide bar type lock tongue to slide is arranged on the cover plate; the locking assembly comprises locking frames, the number of which is consistent with that of the slide bar type lock bolts, and locking channels for the slide bar type lock bolts to be inserted are formed in the locking frames.

As a further optimization of the technical scheme, the guide rail is provided with a limiting component which can limit the sliding amplitude of the sliding rod type lock tongue.

As a further optimization of the technical scheme, the limiting component comprises a guide slot hole formed along the length direction of the guide rail, and a limiting block capable of sliding in the guide slot hole is arranged on the slide bar type lock tongue.

As a further optimization of the technical scheme, the limiting assembly comprises a limiting strip arranged on the guide rail, and a limiting hole is formed in the sliding rod type lock tongue along the length direction of the sliding rod type lock tongue.

The utility model provides a storehouse top advances manhole closing device, includes apron opening and closing mechanism, apron slewing mechanism and foretell apron hold-down mechanism, and apron slewing mechanism includes the bottom and advances the screw rod that the manhole outer wall rotated and be connected, and the apron is passed on the top of screw rod and the rotatory hand wheel that can reciprocate along the screw rod is installed.

As a further optimization of the technical scheme, a rod body of the screw is sleeved with a spring.

As a further optimization of the technical scheme, the cover plate opening and closing mechanism comprises a rotating shaft fixed outside the manhole, a large supporting rod connected to the rotating shaft and a small supporting rod connected to the tail end of the large supporting rod, and the tail end of the small supporting rod is hinged to the upper plate surface of the cover plate.

As a further optimization of the above technical solution, the cover plate opening and closing mechanism comprises a push rod hinged outside the manhole.

As a further optimization of the technical scheme, the upper end face of the manhole wall and the lower plate face of the cover plate are provided with concave-convex matched sealing pairs.

As a further optimization of the technical scheme, the sealing pair comprises an annular bulge and an annular recess, the annular bulge is arranged on the upper end face of the manhole wall, the annular recess is arranged on the lower plate surface of the cover plate, or the annular bulge is arranged on the lower plate surface of the cover plate, and the annular recess is arranged on the upper end face of the manhole wall.

Compared with the prior art, the utility model has the following beneficial effects:

1. after the cover plate is covered on the manhole, the telescopic rod pushes the connecting rod downwards to move, so that the connecting rod pushes the slide bar type lock tongue to slide on the upper plate surface of the cover plate, and the wedge-shaped head at the end part of the slide bar type lock tongue is inserted into the locking frame, so that the cover plate is tightly pressed on the manhole. Therefore, the utility model can simultaneously control the sliding of the plurality of sliding rod type lock tongues below through the movement of the telescopic rod, simultaneously compress the edge of the cover plate, improve the efficiency of compressing work, simultaneously, different sliding rod type lock tongues are simultaneously inserted into the locking frame, and simultaneously compress different angles.

2. When the cover plate is opened, the spring can jack up the cover plate to form a gap between the rubber pad and the upper port of the manhole, so that one side of the rubber pad, which is close to the cover plate rotating mechanism, cannot be extruded laterally in the process of closing the cover plate, the rubber pad is prevented from falling off the cover plate, and the sealing effect of the utility model is ensured.

Drawings

FIG. 1 is a schematic diagram of a front view of the present utility model;

FIG. 2 is a schematic top view of the present utility model;

FIG. 3 is a cross-sectional view of section A-A of FIG. 2 and a compression view of the cover plate compression mechanism;

FIG. 4 is an exploded view of the closure hold-down mechanism;

FIG. 5 is a manhole open schematic;

FIG. 6 is a schematic diagram of the arrangement of the mechanisms of the escalator manhole;

FIG. 7 is a schematic view of the structure in which an annular protrusion is provided on the upper end surface of the sidewall of the manhole and an annular recess is provided on the lower plate surface of the cover plate;

FIG. 8 is a schematic view of the structure in which an annular recess is provided on the upper end surface of the side wall of the manhole and an annular projection is provided on the lower plate surface of the cover plate;

FIG. 9 is a schematic view of the structure of the annular protrusion disposed on the upper end surface of the sidewall of the manhole and outside the sidewall, and the annular recess disposed on the lower plate surface of the cover plate;

FIG. 10 is a schematic view showing a structure of a compressing unit arranged between a manhole and a cover plate in the prior art;

reference numerals: 1. cover plate, 2, cover plate opening and closing mechanism, 21, rotating shaft, 22, big support rod, 23, small support rod, 24, small support rod base, 3, cover plate rotating mechanism, 31, hinge base, 32, spring, 33, screw rod, 34, hinge upper fixing seat, 35, rotating hand wheel, 4, cover plate compressing mechanism, 41, electric push rod, 42, connecting rod, 43, coaxial hinging piece, 44, slide bar type lock tongue, 45, guiding slot hole, 46, limit block, 47, guide rail, 48, wedge-shaped head, 49, locking frame, 410, limit bar, 411, limit hole, 5, manhole, 6, elastic sealing piece, 7, sealing pair, 71, annular bulge, 72, annular recess, 8 and compressing unit.

Detailed Description

The technical solutions of the present utility model are further described in detail below with reference to the accompanying drawings and specific embodiments, and the parts of the present utility model which are not specifically described and disclosed in the following embodiments should be understood as the prior art known or should be known to those skilled in the art.

As shown in fig. 1, the utility model discloses a cover plate pressing mechanism, wherein a cover plate 1 is used for being covered on a cabin top manhole 5, an elastic sealing element 6 is arranged between the cover plate 1 and the cabin top manhole 5, and the elastic sealing element is a sealing rubber pad and is adhered to the lower plate surface of the cover plate 1. In addition, the elastic sealing member 6 can be replaced by a sealing rubber strip, the sealing rubber strip is circumferentially arranged along the lower plate surface of the cover plate 1 and corresponds to the upper end surface of the hole wall of the cabin jacking manhole 5, and when the cover plate 1 is covered on the cabin jacking manhole 5, the cover plate 1 and the cabin jacking manhole 5 are sealed through the sealing rubber strip.

The cover plate pressing mechanism 4 comprises a pressing assembly and a locking assembly. The compression assembly comprises an electric push rod 41 arranged above a cover plate 1, a shell of the electric push rod 41 is fixed on the cover plate 1 through a bracket (not shown in the figure), a telescopic rod of the electric push rod 41 is vertically downwards, the tail end of the telescopic rod is hinged with a plurality of connecting rods 42, the upper ends of the connecting rods 42 are all hinged to the tail ends of the telescopic rod, and the lower ends of the connecting rods 42 face different directions. The end of the connecting rod 42, which is far away from the telescopic rod, is hinged with a slide bar type lock tongue 44, and the end of the slide bar type lock tongue 44, which is far away from the connecting rod 42, is integrally formed and provided with a wedge-shaped head 48. The longitudinal section of the wedge-shaped head 48 is triangular, the lower end surface of the wedge-shaped head 48 is flush with the lower end surface of the slide bar type lock tongue 44, and the upper end surface gradually decreases along the direction of the slide bar type lock tongue 44 away from the connecting rod 42.

Specifically, as shown in fig. 1 and 2, the roof manhole 5 in this embodiment is a square hole, so the cover plate 1 used in cooperation with the manhole 5 is also square, the electric push rod 41 is disposed at the center of the cover plate 1, and four connecting rods 42 hinged below the electric push rod 41 face four sides of the square cover plate 1 respectively. One end of the connecting rod 42 far away from the telescopic rod is connected with the slide bar type lock tongue 44 through the coaxial hinge piece 43, the four slide bar type lock tongues 44 are mutually perpendicular, and the four slide bar type lock tongues 44 are respectively perpendicular to the four sides of the square cover plate 1. The coaxial hinge 43 is a rotation shaft, a raised line extending along the length direction of the connecting rod 42 is arranged at one end of the connecting rod 42 far away from the telescopic rod, a groove part for the raised line to be inserted is arranged at one end of the slide bar type lock tongue 44 facing the connecting rod 42, after the raised line is inserted into the groove part, the groove part and the raised line are sequentially inserted through the rotation shaft, so that the coaxial hinge of the connecting rod 42 and the slide bar type lock tongue 44 is realized, the rotation shaft is perpendicular to the length direction of the connecting rod 42, and the rotation shaft is parallel to the plate surface of the cover plate 1.

When the manhole is a staircase manhole, as shown in fig. 6, since the staircase manhole is rectangular, in order to effectively seal the periphery of the rectangular cover plate 1, two cover plate pressing mechanisms 4 are disposed on the upper surface of the cover plate 1, and each cover plate pressing mechanism 4 is connected with three slide bar type locking bolts 44. Each cover plate pressing mechanism 4 keeps one slide bar type lock tongue 44 towards the short side of the rectangular cover plate 1, and the other two slide bar type lock tongues 44 respectively face the long sides of the two sides, so that each long side of the rectangular cover plate 1 is correspondingly provided with two slide bar type lock tongues 44, and the short side is correspondingly provided with one slide bar type lock tongue 44, thereby ensuring uniform stress around the cover plate 1.

The locking assembly comprises locking frames 49 with the same number as the slide bar type locking bolts 44, and locking channels for inserting the slide bar type locking bolts 44 are formed in the locking frames 49. The locking frame 49 is -shaped and comprises two vertical rods and a cross rod which is positioned at the upper ends of the vertical rods and connected between the two vertical rods, the vertical rods and the cross rod enclose a locking channel, the height of the locking channel is lower than the highest position of the wedge-shaped head 48, so that the wedge-shaped head 48 is extruded by the locking channel along with the insertion of the wedge-shaped head 48 into the locking channel in the compression process of the cover plate 1, the wedge-shaped head 48 drives the cover plate 1 to move downwards to extrude the elastic sealing element 6, and finally the sealing of the elastic sealing element 6 on the manhole 5 is realized.

Two vertical rods of the locking frame 49 are fixed on the outer side of the wall of the manhole 5, and in this embodiment, a bending part extending towards the outside of the manhole 5 is arranged at the lower end of the vertical rod, so that a certain gap is reserved between the vertical rod and the wall of the manhole 5, and interference of the vertical rod to the covering process of the cover plate 1 can be avoided.

In addition, the locking frame 49 may be fixedly arranged on the wall outside the manhole 5, and only the locking channel in the locking frame 49 is required to be ensured to face the wedge-shaped head 48 to be inserted by the wedge-shaped head 48, and the height of the locking channel is lower than the highest position of the wedge-shaped head 48.

The cover plate 1 is provided with a guide rail 47 for sliding the slide bar type lock tongue 44, and the guide rail 47 is provided with a limiting component capable of limiting the sliding amplitude of the slide bar type lock tongue 44. As shown in fig. 1, the limiting assembly includes a guide slot 45 formed along the length direction of a guide rail 47, and a limiting block 46 capable of sliding in the guide slot 45 is provided on the slide bar type lock tongue 44.

The guide rail 47 is a mounting frame arranged on the cover plate 1, the mounting frame is in a strip shape, a sliding channel for the sliding rod type lock tongue 4 to extend in is arranged in the mounting frame, and the direction of the sliding channel is consistent with the length direction of the mounting frame. The guide slot 45 is formed on the side wall of the sliding channel, and the sliding amplitude of the sliding rod type lock tongue 44 is limited by the guide slot 45, so that the depth of the wedge-shaped head 48 extending into the locking frame 49 is controlled, and the sealing degree of the cover plate 1 is controlled.

As another arrangement mode of the limiting assembly, as shown in fig. 3, the limiting assembly includes a limiting strip 410 disposed on the guide rail 47, and a limiting hole 411 is formed on the slide bar type lock tongue 44 along the length direction thereof. In the sliding process of the slide bar type lock tongue 44, the limiting hole 411 moves along with the sliding of the slide bar type lock tongue 44, and the sliding amplitude of the slide bar type lock tongue 44 can be limited by the limiting strip 410 fixed on the guide rail 47.

Fig. 3 is a schematic structural view of the wedge-shaped head 48 inserted into the locking frame 49 (i.e. when the cover plate pressing mechanism 4 is pressed), at this time, the limiting strip 410 abuts against the hole wall at one end of the limiting hole 411 away from the wedge-shaped head 48, and fig. 4 is a schematic structural view of the wedge-shaped head 48 separated from the locking frame 49 (i.e. when the cover plate pressing mechanism 4 is released), at this time, the limiting strip 410 abuts against the hole wall at one end of the limiting hole 411 close to the wedge-shaped head 48.

According to the utility model, the electric push rod 41 of the cover plate pressing mechanism 4 works to drive the telescopic rod on the electric push rod to move up and down, so that the sliding of the lower Fang Duo slide bar type lock tongue 44 can be controlled, the simultaneous pressing of the edge of the cover plate 1 is realized or released, the pressing work efficiency is improved, and the degree of automation is higher.

With continued reference to fig. 1 and 2, the utility model also discloses a cabin top manhole sealing device, which comprises a cover plate opening and closing mechanism 2, a cover plate rotating mechanism 3 and the cover plate compressing mechanism 4.

The cover plate opening and closing mechanism 2 and the cover plate rotating mechanism 3 are arranged on the same side of the manhole 5, and the cover plate opening and closing mechanism 2 comprises a rotating shaft 21 fixed outside the manhole 5, a large supporting rod 22 connected to the rotating shaft 21 and a small supporting rod 23 connected to the tail end of the large supporting rod 22. The rotating shaft 21 is transversely fixed on the wall at one side of the manhole 5, the rotating shaft 21 is connected with a driving motor for driving the rotating shaft to rotate, the two large supporting rods 22 and the two small supporting rods 23 are respectively arranged in parallel and fixed at two ends of the rotating shaft 21, each small supporting rod 23 is coaxially hinged with the corresponding large supporting rod 22, and the specific hinging mode can refer to the connection mode between the connecting rod 42 and the slide rod type lock tongue 44 and is not repeated here. The upper plate surface of the cover plate 1 is provided with a small supporting rod base 24, and the tail end of the small supporting rod 23 is hinged to the upper plate surface of the cover plate 1. Fig. 5 is a schematic diagram of the manhole 5 after opening, when the manhole 5 is opened, the driving motor drives the rotating shaft 21 to rotate, that is, the rotating shaft 21 drives the large supporting rod 22 to rotate, and the rotation of the large supporting rod 22 can pull the small supporting rod 23 to move towards the rotating shaft 21, so as to drive the cover plate 1 to turn around the cover plate rotating mechanism 3, and open the manhole 5; the manhole 5 can be closed by rotating the rotating shaft 21 in the reverse direction.

The two large support rods 22 and the two small support rods 23 are respectively arranged, so that the stability of the cover plate 1 when being opened or closed can be ensured, and the two large support rods 22 and the more than two small support rods 23 can be respectively arranged according to different specific sizes of the cover plate 1.

As another arrangement of the cover opening and closing mechanism 2, the cover opening and closing mechanism 2 includes two pushing rods (not shown in the figure) hinged to the outside of the manhole 5, and the number of the pushing rods is two and the two pushing rods are distributed in parallel. The push rod is electric putter, and electric putter's casing articulates on the wall of manhole 5 one side, and electric putter's telescopic link end articulates the face on apron 1, through electric putter's shrink in order to stimulate apron 1 to open manhole 5, through electric putter's extension with apron 1 lid in manhole 5.

The cover plate opening and closing mechanism 2 of the embodiment can automatically and slowly open and close the cover plate 1, and compared with a mode of manually pulling the cover plate 1, the cover plate opening and closing mechanism reduces the workload of operators and has higher practicability.

As shown in fig. 1 and 7, the cover plate rotating mechanism 3 includes a screw 33 having a bottom end rotatably connected to the outer wall of the manhole 5, and a rotating hand wheel 35 which is capable of moving up and down along the screw 33 is mounted to the top end of the screw 33 through the cover plate 1. The hinge base 31 is fixedly arranged on the outer side wall of the manhole 5, the hinge base 31 comprises two fixed blocks arranged at intervals, a rotating shaft with the axis perpendicular to the axis of the screw 33 is fixedly connected between the two fixed blocks, the bottom of the screw 33 is rotationally connected with the rotating shaft, and the screw 33 can rotate around the axis of the rotating shaft in the opening process of the cover plate 1. The cover plate 1 is fixedly connected with an upper hinge fixing seat 34 corresponding to the hinge base 31, the upper hinge fixing seat 34 is a fixing plate, and a through hole through which the screw 33 can pass is formed in the upper hinge fixing seat 34. The upper hinge fixing seat 34 extends towards the direction away from the cover plate 1, and the upper hinge fixing seat 34 and the cover plate 1 can be connected in a bolt connection, an integral connection or a welding way, and in the embodiment, the two are connected in an integral connection way; the perforations have a diameter greater than the diameter of the screw 33 and are coaxial with the screw 33, facilitating passage of the screw 33 through the perforations.

The rotating hand wheel 35 is positioned above the hinge upper fixing seat 34, the outer diameter of the rotating hand wheel 35 is larger than the diameter of the through hole, the inner diameter is the same as the diameter of the screw rod 33, and the inner side wall of the rotating hand wheel 35 is provided with an inner thread matched with the screw rod 33.

The rod body of the screw 33 is sleeved with a spring 32, and in this embodiment, the spring 32 is located at a portion between the hinge upper fixing seat 34 and the hinge base 31. In the process that the cover plate 1 is pressed on the manhole 5, the rotary hand wheel 35 is rotated to enable the cover plate 1 to move downwards, so that the hinge upper fixing seat 34 and the cover plate 1 are pushed to move towards the manhole 5 until the corresponding cover plate 1 is pressed on the upper end face of the side wall of the manhole 5, and at the moment, the spring 32 is in a compressed state; in the opening process of the cover plate 1, the hand wheel 35 is reversely rotated to enable the cover plate 1 to move upwards, the spring 32 pushes the cover plate 1 to deviate from the direction of the inlet hole 5 under the action of restoring elastic force until a gap is formed between the elastic sealing element 6 and the upper end face of the side wall of the inlet hole 5, then the cover plate 1 is lifted to be away from one side of the cover plate rotating mechanism 3, so that the cover plate 1 is upwards turned and opened, at the moment, the side wall of the inlet hole 5, which is positioned on one side close to the cover plate rotating mechanism 3, cannot laterally squeeze the elastic sealing element 6, and meanwhile, when the cover plate 1 is closed again, the side wall of the inlet hole 5, which is positioned on one side close to the cover plate rotating mechanism 3, cannot laterally squeeze the elastic sealing element 6, so that the elastic sealing element 6 falls off from the cover plate 1 to cause gradual worsening of tightness. Especially when the elastic sealing element 6 arranged on the lower plate surface of the cover plate 1 is a sealing rubber strip, the sealing rubber strip is limited in width and is more easily extruded by the side wall of the manhole 5 to fall off, and the arrangement of the spring 32 on the screw 33 is more beneficial to ensuring the sealing performance of the cover plate 1 when the sealing rubber strip is arranged.

In order to further enhance the orifice sealing effect of the manhole 5, a sealing pair 7 matched with the lower plate surface of the cover plate 1 in a concave-convex way is arranged on the upper end surface of the wall of the manhole 5.

The sealing pair 7 comprises an annular bulge 71 and an annular recess 72, as shown in fig. 7, the annular bulge 71 is arranged on the upper end surface of the wall of the manhole 5 and is positioned in the middle of the upper end surface, and the annular recess 72 is arranged on the lower plate surface of the cover plate 1; as shown in fig. 8, an annular protrusion 71 is provided on the lower plate surface of the cover plate 1, and an annular recess 72 is provided on the upper end surface of the wall of the manhole 5; as shown in fig. 9, an annular projection 71 is provided on the upper end surface of the wall of the manhole 5 at the side of the upper end surface, and an annular recess 72 is provided on the lower plate surface of the cover plate 1. Therefore, the arrangement positions of the annular projection 71 and the annular recess 72 may be various, and only the two are required to ensure the concave-convex fit. Through the cooperation use of annular protruding 71, annular sunken 72, joint strip or elastic sealing member 6 set up between annular protruding 71 and annular sunken 72, have strengthened the fastness of joint strip, cushion, have also increased downthehole, the resistance of hole outer air flow to a certain extent, have improved sealed effect.

The foregoing description of the preferred embodiments of the utility model is not intended to be limiting, but rather is intended to cover all modifications, equivalents, alternatives, and improvements that fall within the spirit and scope of the utility model.

Claims (10)

1. The utility model provides a apron hold-down mechanism, apron (1) are used for the lid to close on storehouse top manhole (5), are provided with elastic sealing element (6), its characterized in that between apron (1) and storehouse top manhole (5): the cover plate pressing mechanism (4) comprises a pressing component and a locking component;

the compressing assembly comprises an electric push rod (41) vertically arranged above the cover plate (1), a shell of the electric push rod (41) is fixed on the cover plate (1) through a bracket, a telescopic rod of the electric push rod (41) is hinged with a plurality of slide bar type lock tongues (44) through a plurality of connecting rods (42), one end, far away from the connecting rods (42), of each slide bar type lock tongue (44) is provided with a wedge-shaped head (48), and a guide rail (47) for the slide bar type lock tongue (44) to slide is arranged on the cover plate (1);

the locking assembly comprises locking frames (49) with the same number as the sliding rod type locking bolts (44), and locking channels for the sliding rod type locking bolts (44) to be inserted are formed in the locking frames (49).

2. A cover plate hold-down mechanism as claimed in claim 1, wherein: the guide rail (47) is provided with a limiting component which can limit the sliding amplitude of the sliding rod type lock tongue (44).

3. A cover plate hold-down mechanism as claimed in claim 2, wherein: the limiting component comprises a guide slot hole (45) formed along the length direction of the guide rail (47), and a limiting block (46) capable of sliding in the guide slot hole (45) is arranged on the slide bar type lock tongue (44).

4. A cover plate hold-down mechanism as claimed in claim 2, wherein: the limiting component comprises a limiting strip (410) arranged on the guide rail (47), and a limiting hole (411) is formed in the sliding rod type lock tongue (44) along the length direction of the sliding rod type lock tongue.

5. The utility model provides a storehouse top advances manhole closing device which characterized in that: the device comprises a cover plate opening and closing mechanism (2), a cover plate rotating mechanism (3) and the cover plate compressing mechanism (4) as claimed in claim 1, wherein the cover plate rotating mechanism (3) comprises a screw rod (33) with the bottom end rotationally connected with the outer wall of a manhole (5), and the top end of the screw rod (33) penetrates through the cover plate (1) and is provided with a rotating hand wheel (35) capable of moving up and down along the screw rod (33).

6. The roof manhole sealing device of claim 5, wherein: the rod body of the screw rod (33) is sleeved with a spring (32).

7. The roof manhole sealing device of claim 5, wherein: the cover plate opening and closing mechanism (2) comprises a rotating shaft (21) fixed outside the manhole (5), a large supporting rod (22) connected to the rotating shaft (21) and a small supporting rod (23) connected to the tail end of the large supporting rod (22), and the tail end of the small supporting rod (23) is hinged to the upper plate surface of the cover plate (1).

8. The roof manhole sealing device of claim 5, wherein: the cover plate opening and closing mechanism (2) comprises a push rod hinged to the outside of the manhole (5).

9. The roof manhole sealing device of claim 5, wherein: the upper end surface of the wall of the manhole (5) and the lower plate surface of the cover plate (1) are provided with a concave-convex matched sealing pair (7).

10. The roof manhole sealing device of claim 9, wherein: the sealing pair (7) comprises an annular bulge (71) and an annular recess (72), wherein the annular bulge (71) is arranged on the upper end face of the wall of the manhole (5), the annular recess (72) is arranged on the lower plate surface of the cover plate (1), or the annular bulge (71) is arranged on the lower plate surface of the cover plate (1), and the annular recess (72) is arranged on the upper end face of the wall of the manhole (5).