A manhole cover mechanism

Abstract

The present invention discloses a manhole cover mechanism, which relates to the technical field of container accessories, including a cover seat and a cover plate, wherein a pin lock assembly capable of being locked with the cover plate is slidably mounted on the cover seat, a power unit capable of being driven in forward and reverse directions is transmission-connected to the cover plate, a slide assembly is mounted on the cover seat, the slide assembly comprises a slide structure arranged on the cover seat, the slide structure has a first limit end and a second limit end, a sliding body is slidably adapted between the first limit end and the second limit end, the sliding body is connected to the power unit, the pin lock assembly is connected to the sliding body, and the pin lock assembly can complete the switching of the locking state as the reaction force generated by the power unit is driven in forward and reverse directions. During the whole process, the present invention does not need to control two power units separately, thereby simplifying the operation steps and improving the simplicity of operation.

Description

Technical Field

[0001] The invention relates to the technical field of container accessories, in particular to a manhole cover mechanism. Background Art

[0002] Manhole cover is a kind of access device used in closed space, which is widely used in ships, storage tanks, industrial equipment and other fields. Its main function is to provide safe access and good sealing performance.

[0003] The basic structure of the existing manhole cover mainly includes a cover seat and a cover plate. One side of the cover plate is connected to the cover seat through a hinge, and a locking member that can be locked with each other is arranged between the other side of the cover plate and the cover seat. In the unlocked state, the cover plate can be deflected by the hinge, thereby controlling the opening and closing of the manhole cover.

[0004] In order to realize automatic opening, closing and locking of the cover plate of the manhole cover, the existing method is to set a driving mechanism to control the switching of unlocking and locking of the locking member, and then set another driving mechanism to control the deflection and opening and closing of the cover plate. However, the disadvantage of the existing solution is that it is necessary to control the two driving mechanisms separately and in turn, which is cumbersome and not simple enough. In order to solve the above problem, we propose a new technical solution. Summary of the invention

[0005] The object of the present invention is to provide a manhole cover mechanism to solve the above-mentioned deficiencies in the prior art.

[0006] In order to achieve the above object, the present invention provides the following technical solutions:

[0007] The lock assembly is connected with the cover plate to release the locking cam, and the locking cam is connected with the locking cam to release the locking cam, so that the locking cam can be locked to the cover plate when the locking cam is in the forward and reverse directions.

[0008] Preferably, the cover seat comprises a base plate, a cover ring is fixed through the base plate, and the cover ring is adapted to be opened and closed with the cover plate.

[0009] Preferably, the power unit has a body part and an output part. The power unit is a telescopic cylinder, the body part is the cylinder barrel part of the telescopic cylinder, and the output part is the piston rod part of the telescopic cylinder.

[0010] Preferably, the slideway structure includes side vertical plates located on both sides of the body part. Each side vertical plate is provided with a line opening on its plate surface. The two ends of the line opening respectively form a first limiting end and a second limiting end. The sliding body is a cylindrical rod connected to the body part, and both ends of the sliding body respectively penetrate through the corresponding line openings.

[0011] Preferably, the pin lock assembly includes a lock tongue part and a lock bolt part. The lock tongue part is fixed to the cover plate, the lock bolt part is fixed to the sliding body, and when the sliding body is located at the second limiting end, the lock tongue part and the lock bolt part are in a separated state.

[0012] Preferably, the lock bolt part includes a frame plate fixed to the sliding body, and a latch strip is fixed on the frame plate. The latch strip can be engaged with the lock tongue part.

[0013] Preferably, a plurality of support plates are vertically fixed on the base plate. Each support plate is provided with a long slot for the lock bolt part to penetrate through on its side surface. The lock bolt part can move synchronously along the length direction of the long slot with the sliding body, so as to complete the switching of the locked and unlocked states.

[0014] Preferably, the cover plate is movably connected to the power unit through a transmission assembly, and the cover plate is movably hinged to the cover opening seat through a hinge.

[0015] Preferably, the transmission assembly includes a support frame. One end of the support frame is movably hinged to the base plate, the other end of the support frame is movably connected to the cover plate through a rocker assembly. A shaft column is rotatably installed in the middle of the support frame, and the shaft column is connected to the output part of the power unit. The support frame can open the cover plate during the forward driving stroke of the power unit.

[0016] In the above technical solution, a manhole cover mechanism provided by the present invention is connected with a power unit capable of driving in both forward and reverse directions through a sliding connection on the cover opening seat, and the power unit and the cover opening seat are connected through a slideway assembly. Thus, the switching of the opening and closing states of the cover plate is completed by changing the driving direction of the power unit. At the same time, by using the reaction forces generated by the power unit driving in different directions, the power unit moves correspondingly on the slideway assembly, so as to complete the switching of the locked and unlocked states of the pin lock assembly. In the whole process, there is no need to separately control two power units, which simplifies the operation steps and improves the simplicity of the operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] To more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments recorded in the present invention, and those of ordinary skill in the art can also obtain other drawings based on these drawings.

[0018] Figure 1 Overall schematic diagram of a manhole cover mechanism of the present invention;

[0019] Figure 2 Of the present invention Figure 1 Enlarged view at A in;

[0020] Figure 3 Schematic diagram of the latch part of a manhole cover mechanism of the present invention;

[0021] Figure 4 Schematic diagram of the rocker assembly of a manhole cover mechanism of the present invention.

[0022] Explanation of reference numerals:

[0023] 1, cover port seat; 1.1, base plate; 1.2, cover port ring; 2, cover plate; 3, power unit; 3.1, body part; 3.2, output part; 4, slideway assembly; 4.1, slideway structure; 4.11, first limit end; 4.12, second limit end; 4.13, side vertical plate; 4.14, line opening; 4.2, sliding body; 5, pin lock assembly; 5.1, lock tongue part; 5.2, latch part; 5.21, frame plate; 5.22, latch bar piece; 6, transmission assembly; 6.1, support frame; 6.2, rocker assembly; 6.21, bar; 6.22, first connecting shaft; 6.23, second connecting shaft; 6.3, shaft column; 7, support plate; 8, long strip opening; 9, hinge piece; 9.1, support plate; 9.2, ear plate; 9.3, hinge shaft. Detailed implementation manners

[0024] In order to enable those skilled in the art to better understand the technical solutions of the present invention, the following will further introduce the present invention in detail in conjunction with the drawings.

[0025] Please refer to Figures 1-4, a manhole cover mechanism provided by an embodiment of the present invention includes a cover seat 1 and a cover plate 2. A pin lock assembly 5 capable of being locked with the cover plate 2 is slidably installed on the cover seat 1. A power unit 3 capable of driving in both forward and reverse directions is drivingly connected to the cover plate 2. A slideway assembly 4 is installed on the cover seat 1. The slideway assembly 4 includes a slideway structure 4.1 provided on the cover seat 1. The slideway structure 4.1 has a first limit end 4.11 and a second limit end 4.12. A slider 4.2 is slidably fitted between the first limit end 4.11 and the second limit end 4.12. The slider 4.2 is connected to the power unit 3, and the pin lock assembly 5 is connected to the slider 4.2. During the forward driving process of the power unit 3, there are two driving strokes. The first driving stroke: the reaction force generated by the power unit 3 causes the slider 4.2 to move from the first limit end 4.11 to the second limit end 4.12 to drive the pin lock assembly 5 to slide and separate from the cover plate 2 for unlocking. The second driving stroke: the forward driving of the power unit 3 causes the cover plate 2 to open. The pin lock assembly 5 can complete the switching of the locked and separated states along with the reaction force generated by the power unit 3 driving in both forward and reverse directions;

[0026] Specifically, the cover seat 1 is connected and installed to the wall surface of a large container such as a tank body. The tank body is, for example, a transport tank on a tank truck. A channel opening is provided on the cover seat 1. Thus, the cover seat 1 forms an access channel on the large container. The cover plate 2 has an open position on the cover seat 1 to keep the channel opening of the cover seat 1 normally accessible. The cover plate 2 also has a closed position on the cover seat 1 that can completely block the channel opening of the cover seat 1. The pin lock assembly 5 has a locked state capable of locking the cover plate 2 in the closed position. The pin lock assembly 5 also has a separated state of releasing the lock on the cover plate 2 in the closed position. The power unit 3 has two driving modes: forward driving and reverse driving. The power unit 3 can provide driving force for the switching of the opening and closing states of the cover plate 2 and the switching of the locked and separated states of the pin lock assembly 5;

[0027] In actual use, for example, when the cover plate 2 is in the closed position and the pin lock assembly 5 is in the locked state, when the cover plate 2 needs to be switched to the open position, the power unit 3 is driven forward at this time. Since the output part of the power unit 3 is connected to the cover plate 2 by transmission, and the body of the power unit 3 is connected to the cover opening seat 1 through the slideway assembly 4, the initial resistance of the cover plate 2 is relatively large at the initial stage of the forward drive of the power unit 3. The resistance sources include the deadweight of the cover plate 2 and the locking of the pin lock assembly 5 in the locked state. The cover plate 2 exerts a reaction force on the forward drive of the power unit 3, so that the power unit 3 moves along the slideway assembly 4. When forward sliding occurs, the power unit 3 switches the pin lock assembly 5 from the locked state to the separated state during the forward sliding process. When the power unit 3 slides forward to the end of the slide assembly 4, the slide assembly 4 limits the forward sliding of the power unit 3. At this time, the pin lock assembly 5 is in the separated state, and the power unit 3 continues to drive forward. After the driving force of the power unit 3 overcomes the resistance of the cover plate 2 itself, the cover plate 2 is switched from the closed position to the open position. Similarly, when it is necessary to restore the cover plate 2 from the open position to the closed position, the pin lock assembly 5 is restored from the separated state to the locked state, and the power unit 3 can be driven in the reverse direction.

[0028] In another embodiment provided by the present invention, the cover seat 1 includes a base plate 1.1, the plate body of the base plate 1.1 is adapted and fixed to the corresponding container wall surface, a cover ring 1.2 is fixed through the upper part of the base plate 1.1, and the cover ring 1.2 forms a channel opening on the container wall surface that communicates with the inside and outside, and the cover ring 1.2 is adapted to be opened and closed with the cover plate 2, that is, the cover plate 2 has a closed position to completely block the cover ring 1.2, and the cover plate 2 has an open position to keep the cover ring 1.2 completely open;

[0029] Furthermore, the cover plate 2 and the power unit 3 are movably connected via a transmission assembly 6, and the cover plate 2 and the cover seat 1 are movably hinged via a hinge 9, the hinge 9 comprises a support plate 9.1 vertically fixed to the base plate 1.1, and ear plates 9.2 fixed to the cover plate 2 are arranged parallel to each other on both sides of the support plate 9.1, and a hinge shaft 9.3 fixed to the ear plate 9.2 is movably penetrated on the support plate 9.1, and the cover plate 2 rotates around the hinge shaft 9.3 when switching back and forth between the closed position and the open position;

[0030] It should be noted that, in the deflection stroke between the closed position and the open position, the cover plate 2 has a vertical position perpendicular to the ring surface, the area between the vertical position and the closed position is an acute angle area, and the area between the vertical position and the open position is an obtuse angle area, with the ring surface of the cover ring 1.2 as the starting surface.

[0031] Among them, the power unit 3 has a body part 3.1 and an output part 3.2. The body part 3.1 is connected to the slideway assembly 4, and the output part 3.2 of the power unit 3 is connected to the cover plate 2 through the transmission assembly 6. Further, the power unit 3 is a telescopic cylinder, the body part 3.1 is the cylinder barrel part of the telescopic cylinder, and the output part 3.2 is the piston rod part of the telescopic cylinder. The telescopic cylinder can be a pneumatic cylinder, a hydraulic telescopic cylinder or a reciprocating linear motor and other reciprocating driving power devices;

[0032] During the actual use process, when the power unit 3 drives forward, at this time, the output part 3.2 of the power unit 3 extends out of the body part 3.1, and the output part 3.2 provides a driving force for the deflection of the cover plate 2 towards the opening position during the extension process. When the power unit 3 drives in the reverse direction, at this time, the output part 3.2 of the power unit 3 retracts into the body part 3.1, and the output part 3.2 provides a driving force for the deflection of the cover plate 2 towards the closing position during the retraction process.

[0033] Another embodiment provided by the present invention, the transmission assembly 6 includes a support frame 6.1. One end of the support frame 6.1 is movably hinged to the base plate 1.1. The trajectory surface generated by the swing of the support frame 6.1 on the base plate 1.1 is parallel to the trajectory surface generated by the swing of the cover plate 2 around the hinge 9. The other end of the support frame 6.1 is movably connected to the cover plate 2 through a rocker assembly 6.2;

[0034] Among them, the rocker assembly 6.2 includes a bar 6.21. One end of the bar 6.21 is rotatably connected with a first connecting shaft 6.22, and the first connecting shaft 6.22 is rotatably connected to the end of the support frame 6.1. The other end of the bar 6.21 is rotatably connected with a second connecting shaft 6.23, and the second connecting shaft 6.23 is fixed to the cover plate 2. The trajectory surface generated by the bar 6.21 during the deflection process is parallel to the trajectory surface generated by the swing of the support frame 6.1 on the base plate 1.1;

[0035] A shaft column 6.3 is rotatably installed in the middle of the support frame 6.1, and the shaft column 6.3 is connected to the output part 3.2 of the power unit 3. The support frame 6.1 can open the cover plate 2 during the forward driving stroke of the power unit 3, that is, switch the cover plate 2 to the opening position. The support frame 6.1 can close the cover plate 2 during the reverse driving stroke of the power unit 3, that is, switch the cover plate 2 to the closing position. Among them, the axis lines of the first connecting shaft 6.22, the second connecting shaft 6.23 and the shaft column 6.3 are all parallel to each other.

[0036] Wherein, when the cover plate 2 is in the closed position, the included angle between the length direction line of the strip bar 6.21 and the length direction line of the support frame 6.1 is in the first included angle state. When the cover plate 2 is in the open position, the included angle between the length direction line of the strip bar 6.21 and the length direction line of the support frame 6.1 is in the second included angle state, and the angle of the first included angle state is smaller than the angle of the second included angle state;

[0037] During the actual use process, when the transmission component 6 receives the forward drive of the power unit 3, specifically, the support frame 6.1 deflects forward around the hinge point on the base plate 1.1. During the forward deflection of the support frame 6.1, it is in sliding contact with the second connecting shaft 6.23, so as to provide a driving force for the cover plate 2 to deflect towards the open position. When the cover plate 2 deflects into the obtuse angle area, at this time, the cover plate 2 can deflect towards the open position autonomously under its own gravity. At this time, the support frame 6.1 is separated from the second connecting shaft 6.23. The support frame 6.1 and the second connecting shaft 6.23 are connected by the strip bar 6.21 and the first connecting shaft 6.22 until the cover plate 2 reaches the open position;

[0038] When the transmission component 6 receives the reverse drive of the power unit 3, specifically, the output part 3.2 of the power unit 3 generates a pulling force on the support frame 6.1 through the shaft column 6.3, so that the support frame 6.1 deflects reversely around the hinge point on the base plate 1.1. At the same time, the support frame 6.1 provides a driving force for the cover plate 2 to deflect towards the closed position through the rocker component 6.2. When the cover plate 2 deflects into the acute angle area, at this time, the cover plate 2 can deflect towards the closed position autonomously under its own gravity until the cover plate 2 reaches the closed position;

[0039] That is to say, during the process of the cover plate 2 deflecting from the closed position to the open position, the power unit 3 provides a pushing driving force for the cover plate 2 deflecting in the acute angle area through the transmission component 6. During the process of the cover plate 2 deflecting from the open position to the closed position, the power unit 3 provides a pulling driving force for the cover plate 2 deflecting in the obtuse angle area through the transmission component 6, so as to realize the reciprocating switching of the cover plate 2 between the closed position and the open position.

[0040] Another embodiment provided by the present invention, the slideway assembly 4 includes a slideway structure 4.1 arranged on the base plate 1.1. The slideway structure 4.1 has a first limiting end 4.11 and a second limiting end 4.12. A sliding body 4.2 is slidably adapted between the first limiting end 4.11 and the second limiting end 4.12. The sliding body 4.2 is connected to the power unit 3. The reaction force generated during the forward drive of the power unit 3 causes the sliding body 4.2 to move from the first limiting end 4.11 to the second limiting end 4.12;

[0041] Specifically, the slideway structure 4.1 includes side vertical plates 4.13 located on both sides of the body part 3.1. The plate surfaces of the two side vertical plates 4.13 are parallel to each other, and a linear slideway is formed between the plate surfaces of the two side vertical plates 4.13. The plate surfaces of the two side vertical plates 4.13 are fixedly perpendicular to the base plate 1.1. The length direction lines of the two side vertical plates 4.13 are parallel to the telescopic direction line of the output part 3.2 of the power unit 3. A line opening 4.14 is provided on the plate surface of each side vertical plate 4.13. The line openings 4.14 on the two side vertical plates 4.13 are on the same horizontal plane. The length direction line of the line opening 4.14 is parallel to the length direction line of the side vertical plate 4.13. The two ends of the line opening 4.14 respectively form a first limiting end 4.11 and a second limiting end 4.12. The sliding body 4.2 is a cylindrical rod connected to the body part 3.1. The side surface of the cylindrical rod is fixed to the body part 3.1 of the power unit 3. The two ends of the sliding body 4.2 respectively penetrate through the corresponding line openings 4.14. A limiting block for axially limiting the movement of the sliding body 4.2 is fixed on the cylindrical rod to ensure that the movement direction line of the cylindrical rod is always perpendicular to the axis line of the cylindrical rod;

[0042] Furthermore, the pin lock assembly 5 includes a lock tongue part 5.1 and a lock bolt part 5.2. The lock tongue part 5.1 is fixed to the cover plate 2, and the number of the lock tongue parts 5.1 is two. The lock bolt part 5.2 is fixed to the sliding body 4.2. The lock bolt part 5.2 can move synchronously with the sliding body 4.2. There are a locked state and a separated state between the lock tongue part 5.1 and the lock bolt part 5.2. When the lock tongue part 5.1 and the lock bolt part 5.2 are in the locked state, at this time the cover plate 2 is in the closed position, and the lock bolt part 5.2 contacts the upper part of the lock tongue part 5.1, so as to limit the deflection of the cover plate 2 towards the open position. When the lock tongue part 5.1 and the lock bolt part 5.2 are in the separated state, the lock bolt part 5.2 is separated from the lock tongue part 5.1, and the lock bolt part 5.2 is located in the area outside the deflection track lines of the lock tongue part 5.1 and the cover plate 2, so as to ensure that the cover plate 2 can normally reciprocate between the closed position and the open position;

[0043] In actual use, when the sliding body 4.2 is located at the second limiting end 4.12, the lock tongue part 5.1 and the lock bolt part 5.2 are in the separated state. When the sliding body 4.2 is located at the first limiting end 4.11, the lock tongue part 5.1 and the lock bolt part 5.2 are in the locked state.

[0044] Specifically, when the cover plate 2 needs to be switched from the closed position to the open position, when the power unit 3 has not been started yet, the cover plate 2 is still in the closed position at this time, the sliding body 4.2 is located at the first limit end 4.11, and the lock tongue part 5.1 and the latch part 5.2 are in the locked state. When the power unit 3 drives forward, the output part 3.2 of the power unit 3 extends out of the body part 3.1, so as to receive the reaction force of the cover plate 2. At this time, the body part 3.1 of the power unit 3 slides forward through the sliding body 4.2 from the first limit end 4.11 towards the second limit end 4.12. When the sliding body 4.2 reaches the position of the second limit end 4.12, the second limit end 4.12 restricts the sliding body 4.2, so that the sliding body 4.2 stops sliding forward. At the same time, the latch part 5.2 also switches from the locked state to the separated state along with the sliding body 4.2. Then, as the output part 3.2 continues to drive forward, at this time, the transmission component 6 can receive the forward drive of the power unit 3 and cause the cover plate 2 to deflect towards the open position direction;

[0045] Similarly, when the cover plate 2 needs to be switched from the open position to the closed position, at this time, the output part 3.2 of the power unit 3 is retracted into the body part 3.1. At this time, the body part 3.1 of the power unit 3 slides reversely through the sliding body 4.2 from the second limit end 4.12 towards the first limit end 4.11. When the sliding body 4.2 reaches the position of the first limit end 4.11, the first limit end 4.11 restricts the sliding body 4.2, so that the sliding body 4.2 stops sliding reversely;

[0046] It should be noted that when the cover plate 2 deflects into the acute angle area, at this time, the cover plate 2 can deflect towards the closed position under the action of its own gravity. At this time, the deflection speed of the cover plate 2 is greater than the speed at which the output part 3.2 of the power unit 3 retracts into the body part 3.1. When the cover plate 2 deflects towards the closed position, it applies a downward pressure to the power unit 3, and the component force generated by the downward pressure causes the body part 3.1 to slide forward through the sliding body 4.2 from the first limit end 4.11 towards the second limit end 4.12, so that the lock tongue part 5.1 and the latch part 5.2 are still in the separated state;

[0047] When the cover plate 2 reaches the closed position, at this time, the output part 3.2 of the power unit 3 continues to retract into the body part 3.1. At this time, the body part 3.1 of the power unit 3 slides reversely through the sliding body 4.2 from the second limit end 4.12 towards the first limit end 4.11. When the sliding body 4.2 reaches the position of the first limit end 4.11, at this time, the lock tongue part 5.1 and the latch part 5.2 are in the locked state, so as to lock the cover plate 2 in the closed position.

[0048] Another embodiment provided by the present invention, the latch portion 5.2 includes a frame plate 5.21 fixed to the sliding body 4.2. The plate surface of the frame plate 5.21 is parallel to the horizontal plane. A latch strip 5.22 is fixed on the frame plate 5.21. The latch strip 5.22 and the frame plate 5.21 are in the same plane. The latch strip 5.22 is of an L-shaped structure. The latch strip 5.22 has a straight strip portion parallel to the length direction line of the frame plate 5.21. The latch strip 5.22 can be engaged with the lock tongue portion 5.1;

[0049] Furthermore, a plurality of support plates 7 are vertically fixed on the base plate 1.1. Long strip openings 8 for the latch portion 5.2 to pass through are provided on the side surfaces of the support plates 7. The length direction line of the long strip opening 8 is parallel to the length direction line of the line opening 4.14. The latch portion 5.2 can move synchronously along the length direction line of the long strip opening 8 with the sliding body 4.2, so as to complete the switching of the locked and unlocked states;

[0050] During actual use, the frame plate 5.21 is connected to the sliding body 4.2. The frame plate 5.21 can drive the latch strip 5.22 to move synchronously with the sliding body 4.2. The support plate 7 limits the frame plate 5.21 in the direction perpendicular to the base plate 1.1 through the long strip opening 8, so as to improve the stability when the lock tongue portion 5.1 and the latch portion 5.2 are in the locked state.

[0051] Another embodiment provided by the present invention, the driving power unit 3, the slideway assembly 4 and the transmission assembly 6 constitute a driving assembly. There are two sets of driving assemblies, and the two sets of driving assemblies are respectively located on both sides of the cover plate 2. The two ends of the frame plate 5.21 of the pin lock assembly 5 are connected to the corresponding slideway assembly 4.

[0052] Only some exemplary embodiments of the present invention have been described by way of illustration above. Undoubtedly, for those of ordinary skill in the art, without departing from the spirit and scope of the present invention, the described embodiments can be modified in various different ways. Therefore, the above drawings and descriptions are illustrative in nature and should not be construed as limiting the protection scope of the claims of the present invention.

Claims

1. A manhole cover mechanism, comprising a cover seat (1) and a cover plate (2), characterized in that: A pin lock assembly (5) capable of being locked with the cover plate (2) is slidably mounted on the cover seat (1); a power unit (3) capable of being driven in forward and reverse directions is transmission-connected to the cover plate (2); a slideway assembly (4) is mounted on the cover seat (1); the slideway assembly (4) comprises a slideway structure (4.1) arranged on the cover seat (1); the slideway structure (4.1) has a first limit end (4.11) and a second limit end (4.12); a sliding body (4.2) is slidably adapted between the first limit end (4.11) and the second limit end (4.12); the sliding body (4.2) is slidably adapted to the power unit ( 3), the pin lock assembly (5) is connected to the sliding body (4.2), and the power unit (3) has two driving strokes during the forward driving process. The first driving stroke is that the reaction force generated by the power unit (3) causes the sliding body (4.2) to move from the first limit end (4.11) to the second limit end (4.12) to drive the pin lock assembly (5) to slide and separate from the cover plate (2) to unlock; the second driving stroke is that the power unit (3) is driven forward to open the cover plate (2), and the pin lock assembly (5) can complete the switching of the locking state with the reaction force generated by the power unit (3) in the forward and reverse directions; The pin lock assembly (5) comprises a lock tongue portion (5.1) and a latch portion (5.2), wherein the lock tongue portion (5.1) is fixed to the cover plate (2), and the latch portion (5.2) is fixed to the sliding body (4.2), and when the sliding body (4.2) is located at the second limiting end (4.12), the lock tongue portion (5.1) and the latch portion (5.2) are in a separated state; The latch portion (5.2) comprises a frame plate (5.21) fixed to the sliding body (4.2), a latch strip (5.22) being fixed to the frame plate (5.21), and the latch strip (5.22) being capable of being engaged with the bolt portion (5.1); The cover seat (1) comprises a base plate (1.1), the cover plate (2) and the power unit (3) are movably connected via a transmission assembly (6), the transmission assembly (6) comprises a support frame (6.1), one end of the support frame (6.1) is movably hinged to the base plate (1.1), the other end of the support frame (6.1) is movably connected to the cover plate (2) via a rocker assembly (6.2), and the rocker assembly (6.2) comprises a bar (6. 21), one end of the bar (6.21) is rotatably connected to a first connecting shaft (6.22), the first connecting shaft (6.22) is rotatably connected to the end of the support frame (6.1), a shaft column (6.3) is rotatably mounted in the middle of the support frame (6.1), the shaft column (6.3) is connected to the output part (3.2) of the power unit (3), and the support frame (6.1) can open the cover plate (2) in the forward driving stroke of the power unit (3).

2. A manhole cover mechanism according to claim 1, characterized in that: A cover ring (1.2) is fixedly passed through the upper portion of the base plate (1.1), and the cover ring (1.2) is adapted to be opened and closed with the cover plate (2).

3. A manhole cover mechanism according to claim 2, characterized in that: The power unit (3) comprises a body part (3.1) and an output part (3.2); the power unit (3) is a telescopic cylinder, the body part (3.1) is the cylinder barrel part of the telescopic cylinder, and the output part (3.2) is the piston rod part of the telescopic cylinder.

4. A manhole cover mechanism according to claim 3, characterized in that: The slideway structure (4.1) comprises side upright plates (4.13) located on both sides of the machine body (3.1), and the plate surface of each side upright plate (4.13) is provided with a line opening (4.14), and the two ends of the line opening (4.14) respectively constitute a first limit end (4.11) and a second limit end (4.12), and the sliding body (4.2) is a cylindrical rod connected to the machine body (3.1), and the two ends of the sliding body (4.2) respectively penetrate the corresponding line opening (4.14).

5. A manhole cover mechanism according to claim 4, characterized in that: A plurality of support plates (7) are vertically fixed on the base plate (1.1), and a long strip opening (8) for a locking latch (5.2) to pass through is provided on the side surface of each support plate (7). The locking latch (5.2) can move synchronously with the sliding body (4.2) along the length direction line of the long strip opening (8), thereby completing the switching of the locking state.

6. A manhole cover mechanism according to claim 5, characterized in that: The cover plate (2) and the cover seat (1) are movably hinged via a hinge (9).

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