A manhole door fastening device
By controlling the opening and closing of the manhole door with a bladder-type air spring and a compressed air system, the problem of numerous and easily damaged bolts in the normal pressure inspection manhole door fastening method is solved, enabling fast and reliable maintenance operations.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- SINOSTEEL TIANCHENG ENVIRONMENTAL PROTECTION SCI&TECH
- Filing Date
- 2026-04-30
- Publication Date
- 2026-06-05
AI Technical Summary
The existing fastening methods for atmospheric pressure inspection manholes have the following drawbacks: a large number of bolts are required, maintenance is time-consuming and labor-intensive, and the manholes are prone to damage. Furthermore, the frequent opening and closing of manholes is necessary during the maintenance of large equipment, resulting in low maintenance efficiency.
The system employs a bladder-type air spring and a compressed air system. The bladder-type air spring provides support force to press the manhole cover, and the inflation and deflation of the air bladder is controlled by a three-position three-way valve to achieve rapid opening and closing of the manhole door.
It reduced manpower and time consumption, improved the opening and closing efficiency of manhole doors, reduced the risk of bolt damage, and optimized the maintenance process.
Smart Images
Figure CN122148164A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to manhole doors for inspection under normal pressure, and more specifically to a manhole door fastening device. Background Technology
[0002] Each ash hopper in various dust collection systems or centralized ash silos needs to be equipped with an atmospheric pressure inspection manhole.
[0003] The main methods for fastening manhole doors are as follows: Screw fastening method: This is the most common fastening method. Usually, holes are pre-drilled along the edge of the manhole cover, and then holes are drilled in the frame to fix the screws. Fastening method: This method involves fastening the door cover to the frame with fasteners and securing the door cover with the fasteners. Sometimes, screws are also used to connect the door cover to the frame. The movable overlapping fastening method is a method of fastening by overlapping the door cover and the slot on the frame of the manhole door. It includes two forms: cross-slot and same-slot. If the cross-slot is used, additional frame support may be required.
[0004] Current atmospheric pressure manhole doors have certain problems, mainly in the following aspects: There are too many bolts around the manhole, numbering in the dozens. Each time the manhole is overloaded, disassembly and repair are time-consuming and laborious, and over time, the bolts and internal threads may be damaged. Large equipment has a large number of manholes for maintenance, and all of them need to be opened and closed during maintenance, which takes time and manpower. Summary of the Invention
[0005] This invention provides a manhole door fastening device to address the problems existing in the prior art.
[0006] The technical solution of this invention is: a manhole door fastening device, comprising a base and a door cover, the door cover being placed on the base, a sealing strip being provided inside the door cover, two ear holes being provided on both sides of the base, a crossbar being inserted through the two ear holes, the crossbar being placed on the door cover, and a bladder-type air spring being provided between the crossbar and the door cover; the bladder-type air spring having a bladder-type air bladder inside, air bladder metal cover plates on both sides of the air bladder, the upper and lower parts of the air bladder metal cover plates being rubber air bladders, and an air inlet and outlet hole being provided in the middle of the air bladder metal cover plate; the bladder-type air spring being connected to a compressed air hose, the compressed air hose being connected to a compressed air source through a three-position three-way manual valve; and a one-way valve being provided on the compressed air hose.
[0007] The door cover is round or square.
[0008] The beneficial effects of this invention are: by using the supporting force generated by the air spring between the manhole base and the crossbar to press the manhole cover plate, the bladder-type manhole can be quickly inflated and deflated, which can greatly save manpower and time and achieve excellent results. Attached Figure Description
[0009] Figure 1 This is a front view of a manhole door fastening device.
[0010] Figure 2 This is a three-dimensional structural diagram of a manhole door fastening device.
[0011] Figure 3 This is a left view of a manhole door fastening device.
[0012] Figure 4 This is a structural diagram of a bladder-type air spring.
[0013] Figure 5 This is a diagram of the base of a manhole door.
[0014] Figure 6 This is a diagram of a manhole cover.
[0015] Figure 7 It is a diagram of a horizontal bar structure.
[0016] Figure 8 This is a diagram of the compressed air connection.
[0017] Figure 9 This is a connection diagram for a three-position three-way valve.
[0018] In the diagram: 1-base; 2-door cover; 3-bladder air spring; 4-crossbar; 5-compressed air hose; 6-three-position three-way valve; 7-one-way valve; 11-ear hole; 31-rubber airbag; 32-air inlet / outlet port; 33-airbag metal cover. Detailed Implementation
[0019] The present invention will be further described below with reference to the accompanying drawings. It should be noted that the description of these embodiments is for the purpose of aiding understanding the present invention, but does not constitute a limitation thereof. Furthermore, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.
[0020] like Figure 1 , Figure 2 , Figure 3 , Figure 4A manhole door fastening device includes a base 1 and a door cover 2. The door cover 2 covers the base 1 and has a sealing strip inside. The base 1 has two ear holes 11 on both sides, through which a crossbar 4 passes. The crossbar 4 is set on the door cover 2, and a bladder-type air spring 3 is set between the crossbar 4 and the door cover 2. The bladder-type air spring 3 has a bladder-type air bladder inside, and air bladder metal cover plates 33 on both sides of the air bladder. The upper and lower parts of the air bladder metal cover plates 33 are rubber air bladders 31, and an air inlet and outlet hole 32 is set in the middle of the air bladder metal cover plates 33. The bladder-type air spring 3 is connected to a compressed air hose 5, and the compressed air hose 5 is connected to a compressed air source through a three-position three-way valve 6. A one-way valve 7 is set on the compressed air hose 5.
[0021] The air spring 6 is commonly known as an air spring, air spring cylinder, or bladder cylinder.
[0022] The door cover 2 is round or square.
[0023] Figure 5 It is a manhole base 1, with two ear holes 11 on the base 1, and a horizontal bar 4 inserted through the two ear holes 11.
[0024] Figure 6 It is the manhole door cover 2. A sealing gasket can be used between the door cover 2 and the base 1 to ensure a tight seal.
[0025] Figure 7 The horizontal bar 4 ensures that the door cover 2 presses firmly against the base 1 when the airbag is inflated.
[0026] Figure 8 This is a diagram of the compressed air connection. The compressed air hose 5 is connected via a quick plug, and the inflation, pressure holding, and deflation states of the airbag are changed via a three-position three-way valve 6.
[0027] like Figure 9 The three-way valve 6 can also be replaced by a three-way valve, an inflation valve, and an deflation valve.
[0028] The present invention utilizes the states (inflation, pressure holding, and deflation) of a three-position three-way valve 6. Its working principle is as follows: when the handle is in the "inflation" position: P → A are connected, and the air source inflates the bladder air spring 6; when the handle is in the "neutral" position: P, A, and T are not connected, and the system maintains pressure; when the handle is in the "deflation" position: A → T are connected, and the air in the bladder air spring 8 is discharged to the atmosphere. By changing the state of the bladder air spring 6, the opening and closing of the manhole door can be controlled.
[0029] It should be understood that those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the protection scope of the appended claims.
Claims
1. A manhole door fastening device, comprising a base (1) and a door cover (2), wherein the door cover (2) covers the base (1), characterized in that: The door cover (2) is provided with a sealing strip. The base (1) is provided with two ear holes (11) on both sides. The two ear holes (11) are inserted through a crossbar (4). The crossbar (4) is set on the door cover (2). A bladder-type air spring (3) is set in the middle between the crossbar (4) and the door cover (2). The bladder-type air spring (3) is filled with a bladder-type air bladder. The two sides of the air bladder are air bladder metal cover plates (33). The upper and lower parts of the air bladder metal cover plates (33) are rubber air bladders (31). An air inlet and outlet hole (32) is set in the middle of the air bladder metal cover plates (33). The bladder-type air spring (3) is connected to a compressed air hose (5). The compressed air hose (5) is connected to a compressed air source through a three-position three-way valve (6). A one-way valve (7) is provided on the compressed air hose (5).
2. The manhole door fastening device according to claim 1, characterized in that: The door cover (2) is round or square.