Manhole protection device

Abstract

To provide a curing device which covers at least a part of an inner surface of a manhole such as a storage tank, and efficiently cures the part.SOLUTION: A curing device is applied to a manhole 110 that has a cylindrical shape and contains a magnetic material, and includes a curing mat 20 that can be attached to at least a part of an inner face of the manhole by a magnetic force. The curing mat preferably has cushioning property since an operator moves thereon.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to the protection of manholes installed in the walls of structures such as storage tanks, towers, and tanks, and in particular to a protection device for protecting the inner surfaces of manholes from scratches and dirt. [Background technology]

[0002] When constructing a structure such as a storage tank for oil or the like, or when inspecting, repairing, or performing other internal work during maintenance, workers may enter the structure through a horizontal manhole installed in the wall of the structure (or in the side wall of a storage tank) to perform their work. During this process, the inside of the manhole, especially the lower inside, may be scratched by the tools carried by the workers, or may become dirty with mud, paint, etc. on the workers' shoes or clothing.

[0003] For this reason, it has been common practice to perform protective work by fixing a rag or polymer sheet called protective sheet 100 to the lower inner surface of a manhole 110 to protect that surface, as shown in (A) of Figure 9. The protective sheet 100 is usually fixed by attaching both ends of the protective sheet 100 to the inner surface of the manhole 110 with protective adhesive tape 120.

[0004] Furthermore, when a gasket surface 130 is formed on the flange portion around the manhole opening, in order to protect this gasket surface 130 as well, conventionally, a protective work was carried out in which the gasket surface 130 around the manhole opening was covered with protective adhesive tape 140, as shown in Fig. 9(B). Another method of protecting the gasket surface 130 was to place a previously used gasket on that portion and fix it with adhesive tape or the like. Summary of the Invention [Problem to be solved by the invention]

[0005] However, the above-mentioned protective work is time-consuming, and there is a problem in that it takes time to remove the protective sheets and adhesive tape after protective work is completed and to restore the protected areas.

[0006] Therefore, a first object of the present invention is to solve the above problems and provide a protective device that can cover at least a portion of the inner surface of a manhole and efficiently protect that portion.

[0007] In addition, when the gasket surface is cured with adhesive tape, there is a problem that it takes a lot of time to apply the adhesive tape to the gasket surface without any gaps, and to remove the adhesive tape after curing and restore the gasket surface. The same problem occurs when the gasket surface is covered with a used gasket, and there is a risk that the used gasket itself cannot be used, especially when the used gasket is contaminated with contaminants or other dust. In addition, when the gasket surface is cured, it is usually done at the same time as curing the inner surface of the manhole, so it is considered to be disadvantageous in terms of work efficiency to perform both curings separately.

[0008] Therefore, the second object of the present invention is to solve the above-mentioned problems when curing a gasket surface and to provide a curing device that can efficiently cure the gasket surface and the inner surface of a manhole. [Means for solving the problem]

[0009] The present invention has been made in consideration of the fact that manholes used in many structures such as storage tanks are cylindrical and contain magnetic material, and a curing device according to one aspect of the present invention is characterized by comprising a curing mat that can be attached to at least a part of the inner surface of the manhole by magnetic force. As a source of magnetic force, a bendable magnetic sheet may be used as a basic component of the curing mat, or a permanent magnet such as a neodymium magnet fixed to a part of the curing mat may be used.

[0010] In addition, since workers move on the protective mat, it is preferable that the protective mat has cushioning properties. When using a magnetic sheet, it is considered to configure the magnetic sheet by attaching a protective material to at least one side of the magnetic sheet (usually the side that the worker comes into contact with).

[0011] In addition, a protective device according to another aspect of the present invention is characterized in that, in addition to the protective mat, it is provided with a protective sheet that can be magnetically attached to the surrounding area of ​​the manhole opening so as to cover the gasket surface around one of the openings of the manhole.

[0012] As with the curing mat, the curing sheet may also use a bendable magnetic sheet as a basic component of the curing sheet as a source of magnetic force, or a permanent magnet such as a neodymium magnet fixed to a part of the curing sheet. It is also preferable that the curing sheet has cushioning properties.

[0013] It is preferable that the curing sheet can be detachably joined to the curing mat so that the curing sheet and the curing mat can be used simultaneously.

[0014] Furthermore, since the protective mat or protective sheet is attached to the manhole by magnetic force, it is possible that it may come off for some reason, and since manhole protective covering often takes a long time, it is expected that the opening of the manhole will be opened and closed frequently. Therefore, it is preferable that the protective cover according to the present invention further comprises a protective cover that is arranged to cover one opening of the manhole, and that is configured to be fixed to the cylindrical part of the manhole by tightening the opening with a string body with a string fastener, also called a cord lock or cord stopper, provided at the opening of the protective cover. Effect of the Invention

[0015] A curing device equipped with a curing mat as described above can achieve the first object of the present invention, and since it can be attached to the inner surface of a manhole by magnetic force, it can be easily installed even by someone with no curing skills.

[0016] Furthermore, the curing device according to the present invention is equipped with a curing sheet that protects the gasket surface in addition to the curing mat, and this can also be attached to cover the gasket surface by magnetic force, making it possible to achieve the second object of the present invention. In particular, if the curing sheet can be detachably attached to the curing mat, it becomes possible to install the curing sheet at the same time as installing the curing mat, improving work efficiency. On the other hand, the curing mat and the curing sheet can be separated and used separately, so it is also possible to perform only the curing work as needed.

[0017] Furthermore, when the above-mentioned protective cover is provided, by using a string body with a string fastener, the protective cover can be attached to the manhole without using adhesive tape, which is particularly suitable for cases where the manhole opening is frequently opened and closed.

[0018] In addition, the protective mat, protective sheet and protective cover in the protective equipment can be reused. [Brief description of the drawings]

[0019] [Figure 1] 1A and 1B are perspective views showing a curing mat and a curing sheet of a curing apparatus according to the present invention, in which (A) shows them in a separated state and (B) shows them in a combined state. [Diagram 2] FIG. 2 is a front view showing the state in which the curing device of FIG. 1 is installed in a manhole. [Diagram 3] FIG. 3 is a cross-sectional view taken along line III-III in FIG. [Figure 4] FIG. 2 is a front view showing a schematic view of a curing cover of the curing apparatus according to the present invention. [Diagram 5] FIG. 2 is a front side view showing a schematic view of a curing cover of the curing apparatus according to the present invention. [Figure 6]FIG. 11 is a perspective view showing a curing mat in a curing apparatus according to another embodiment of the present invention. [Figure 7] FIG. 11 is a perspective view showing a curing sheet in a curing apparatus according to another embodiment of the present invention. [Figure 8] FIG. 11 is a perspective view showing a protective cover in a protective device according to another embodiment of the present invention. [Figure 9] 1A and 1B are schematic diagrams showing conventional curing methods, in which (A) shows curing of the inner surface of a manhole and (B) shows curing of a gasket surface. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In addition, the same reference numerals are used throughout the drawings to designate the same or corresponding parts, and duplicated explanations will be omitted.

[0021] Fig. 1 shows one embodiment of a manhole protection device according to the present invention. In this embodiment, the protection device 10 is applied to a horizontal manhole 110 installed in a side wall 200 of a storage tank for oil or the like, as shown in Figs. 2 and 3, and the manhole 110 is cylindrical and contains a magnetic material.

[0022] As shown in Fig. 1(A), the curing device 10 is composed of a rectangular plate-shaped curing mat 20 and an annular curing sheet 30. As can be understood from Fig. 2 and Fig. 3, the curing mat 20 in this embodiment is placed on the lower inner surface of the cylindrical part of the manhole 110, and the curing sheet 30 is for protecting an annular gasket surface 130 formed on a flange part surrounding the opening of the manhole 110.

[0023] The curing mat 20 is composed of a magnetic sheet 22. The magnetic sheet 22 is a magnetic sheet obtained by applying a magnetic force to a thin magnetic material, and is flexible and can be curved into a cylindrical shape. In addition, it is preferable that a protective material 24 having cushioning properties is provided on at least one surface of the magnetic sheet 22 (the upper surface in FIG. 1, the surface that the worker comes into contact with). The protective material 24 is preferably configured by sandwiching a sheet material such as a polyethylene foam sheet of an appropriate thickness (for example, Minafoam (registered trademark) of 10 mm thickness manufactured and sold by Sakai Chemical Industry Co., Ltd.) between two appropriate surface materials, but is not limited to this. In the case of a manhole 110 in a storage tank, since a worker crawls through the manhole 110, providing the protective material 24 is effective in supporting the weight of the worker and protecting the knees and hands, thereby obtaining a comfortable working environment. In addition, a tarpaulin having excellent durability, antifouling properties, and water resistance is effective as the surface material of the protective material 24.

[0024] There are various possible dimensions for the protective mat 20, but in order to cover the area through which workers will pass, it is preferable that the short side D1 has a length equivalent to the overall length of the manhole 110, and the long side D2 has a length equivalent to the arc length of the inner surface of the lower half of the manhole 110, i.e., "the inner diameter of the manhole × π ÷ 2".

[0025] The curing sheet 30 is also composed of a magnet sheet 32, similar to the curing mat 20. The curing sheet 30 is preferably provided with a protective material 34 similar to that of the curing mat 20 on at least one side (the side that is visible in FIG. 1 and is exposed to the outside) in order to reduce the impact when a worker touches the curing sheet 30, but since the sheet is rarely touched by workers, the protective material may be thinner than the curing mat 20. The protective material 34 is preferably composed of a polyethylene foam sheet of an appropriate thickness, for example, a sheet material having cushioning properties such as 2 mm thick Belpollen or Minafoam (registered trademark), sandwiched between two appropriate surface materials such as tarpaulin, but is not limited thereto.

[0026] The dimensions of the protective sheet 30 need only be sufficient to cover an area sufficient to conceal the gasket surface 130 of the manhole 110, so that the inner diameter of the protective sheet 30 needs only to be equal to the inner diameter of the gasket surface 130, essentially the inner diameter of the opening of the manhole 110, and the outer diameter of the protective sheet 30 needs only to be equal to the outer diameter of the gasket surface 130.

[0027] Since the curing mat 20 and the curing sheet 30 are preferably used simultaneously during the curing work, it is effective to have them in a combined state as shown in FIG. 1B. As a combining means, various means such as inseparably integrating them are conceivable, but in this embodiment, they are combined separably. That is, an ear 26 is formed in the center of one side edge of the curing mat 20, and this ear 26 can be passed through a center hole of the curing sheet 30 and folded to abut against a part of the curing sheet 30. In addition, one side of a hook-and-loop fastener known as Magic Tape (registered trademark) (not shown) is provided on the folded side surface of the ear 26, and the other side of the hook-and-loop fastener 36 is provided on the surface of the curing sheet 30 that receives the ear 26, and by abutting them, the curing mat 20 and the curing sheet 30 are combined separably. It is not essential to make them separable, but it is effective because only one of the curing mat 20 and the curing sheet 30 may be sufficient depending on the type of curing work. For example, although not shown, a possible embodiment is to use only the protective sheet 30 when it is desired to protect the gasket surface of a manhole cover.

[0028] The ears 26 can also be used as gripping pieces to be held with the fingers for easy handling, particularly removal, of the protective mat 20. They also serve as a marker to indicate that protective covering remains when attempting to close the manhole 110 with a manhole cover. For the same purpose, it is preferable to form ears 38 on the protective sheet 30.

[0029] When using such a curing device 10, when both ends of the short side of the curing mat 20 are brought closer to each other from the state shown in Fig. 1(B), the curing mat 20 is curved and its cross section becomes approximately semicircular. In this state, the side edge of the curing mat 20 opposite to the ears 26, 38 is inserted from the opening of the manhole 110 and pushed in until the curing sheet 30 contacts the flange part of the manhole 110 where the gasket surface 130 is formed. Because the curing mat 20 has self-restoring properties due to the nature of its material, the magnetic sheet 22 of the curing mat 20 contacts the lower inner surface of the manhole 110 as shown in Figs. 2 and 3 simply by removing the force applied thereto. Because the manhole 110 contains a magnetic material, the magnetic sheet 22 of the curing mat 20 adheres tightly to the manhole 110 without any gaps due to the magnetic force. In addition, the protective sheet 30 has its magnetic sheet 32 ​​in contact with the surface of the flange portion of the manhole 110 and adheres to it by magnetic force, covering and protecting the gasket surface 130.

[0030] In this way, the curing device 10 according to the present embodiment can be attached to the manhole 110 by magnetic force, so that the installation can be easily completed without using adhesive tape as in the past. This work does not require any special skills, and even inexperienced workers can fully carry out the desired curing work. When the curing device 10 is installed, workers can enter and exit through the central hole of the curing sheet 30 and move back and forth on the curing mat 20, but the surface of the manhole 110 under the curing mat 20 and the curing sheet 30 is not scratched or stained at that time, and even if the worker comes into contact with the curing mat 20 and the curing sheet 30, the protective materials 24, 34 protect the worker, making it possible to perform maintenance and other work comfortably. In addition, even if the curing mat 20 and the curing sheet 30 are relatively thin, they are in close contact with the contact surface with the manhole 110, so there is no risk of wrinkles.

[0031] When the maintenance work for the storage tank is completed and the protection of the manhole 110 is no longer necessary, the protection device 10 can be removed from the manhole 110 by pulling the tabs 26, 38 with enough force to overcome the magnetic force of the magnetic sheets 22, 32. This removal work is much easier than the conventional work of peeling off adhesive tape, and it is also unnecessary to remove the adhesive remaining in the manhole 110 after peeling off the adhesive tape. In addition, since the protection mat 20 and the protection sheet 30 are separable, for example, when the gasket surface 130 is to be restored, only the protection sheet 30 can be removed, and when the inner surface of the manhole 110 is to be restored, only the protection mat 20 can be removed.

[0032] Furthermore, the protective mat 20 and protective sheet 30 that are removed after curing can be reused because they are not attached with adhesive tape or the like.

[0033] By the way, maintenance work for storage tanks often takes a long time, and in such cases, conventionally, the curing sheet on the inner surface of the manhole and the adhesive tape on the gasket surface were left on the manhole as they were, and instead of using a manhole cover, the manhole opening was temporarily closed with a curing cover as a fireproof and waterproofing measure. Conventional curing covers are made of a fireproof and waterproof sheet material such as tarpaulin, which is placed over the manhole opening, and the free edge of the curing cover is gathered together with the cylindrical part of the manhole and secured with adhesive tape or rope.

[0034] However, when performing maintenance or other work, the protective cover must be removed each time, and when the work is completed, the protective cover must be reinstalled. Reinstalling this protective cover is time-consuming, and there is a risk of gaps occurring when fastening with adhesive tape or rope. Furthermore, when the protective cover is fixed with adhesive tape, it is often difficult to reuse the protective cover.

[0035] On the other hand, in the case of the curing device 10 according to the present invention, since the curing mat 20 and the curing sheet 30 can be easily removed, the curing cover is important for preventing the curing mat 20 and the like from accidentally falling off.

[0036] Therefore, a novel curing cover 40 as shown in Figs. 4 and 5 has been invented as an optional component of the curing apparatus 10.

[0037] The protective cover 40 according to an embodiment of the present invention is made of a flexible sheet material suitable for fireproofing and waterproofing, such as tarpaulin, as in the conventional case, and is configured in a bag shape so as to cover the entire flange of the manhole 110. A string passage part 42 is formed at the periphery of the mouth of the protective cover 40, and a single string 44 is passed through it in a loop shape. An ester round rubber string having a diameter of about 4 mm is suitable as the string 44, and by pulling both ends of this string 44, the mouth of the protective cover 40 can be elastically tightened in a purse shape. Both ends of the string 44 are passed through a string fastener 46 generally called a cord stopper or cord lock (for example, a cord lock (CL2-T) manufactured and sold by Nifco Co., Ltd.), and the tightening degree of the mouth of the protective cover 40 can be easily and quickly adjusted by this string fastener 46. Conventional methods of fastening with adhesive tape or ropes tended to result in gaps between the protective cover and the manhole, but the protective cover 40 of this embodiment can increase the degree of sealing between the manhole 110, improving fire resistance and waterproofing. In addition, it is possible to suppress or prevent gas inside the storage tank from escaping to the outside, improving safety.

[0038] In addition, a window 48 is formed on the main surface of the protective cover 40, which can be opened and closed airtightly by a fastener (for example, a plastic fastener with double-sided head joint). A gas hose 50 or the like can be installed through this window 48, and it is used to discharge residual gas and odors inside the storage tank to the outside and to maintain an atmosphere of nitrogen or the like. Conventional protective covers were not intended to be reused, so such a window was not provided, but according to the present invention, since the protective cover 40 is also reused, the window 48 is provided, making it possible to discharge residual gas and provide a simple access means for other work. The reference numeral 54 in Figs. 4 and 5 denotes a rain cover that prevents rainwater from entering through a gap that occurs when the gas hose 50 is inserted through the fastener of the window 48.

[0039] In addition, since the main surface of the protective cover 40 is widely exposed, for example, the portion indicated by the reference numeral 52 in FIG. 4 can be used as a display section for displaying work precautions and the like.

[0040] Although the preferred embodiment of the present invention has been described in detail above, it goes without saying that the present invention is not limited to the above embodiment.

[0041] For example, the curing mat 20 shown in Figs. 1 to 3 has a main body made of a magnet sheet 22, and although a magnetic force is generated over almost the entire surface of the curing mat 20, a configuration in which a magnetic force is generated partially may also be used. For example, small magnet sheets may be arranged in a dispersed manner over the entire curing mat 20, or multiple (three in the illustrated embodiment) disk-shaped permanent magnets 60 may be fixed to both ends of the curing mat 20 as shown in Fig. 6. As the permanent magnets 60, for example, neogeo magnets with strong magnetic force are preferable. The main body of the curing mat 20 shown in Fig. 6 may be configured similarly to the protective material of the curing mat 20 shown in Figs. 1 to 3, but is not limited thereto. In the case of the curing mat 20 configured as shown in Fig. 6, if the permanent magnets 60 are kept away from the inner surface of the manhole 110, the curing mat 20 can be moved without being affected by the magnetic force, making it easier to install the curing mat 20.

[0042] The protective sheet 30 protecting the gasket surface 130 shown in Figs. 1 to 3 is an annular, indivisible, one-piece type, but it may be a dividable one. For example, as shown in Fig. 7, a plurality of arc-shaped protective sheet segments 70 may be arranged in a ring shape, with the ends of adjacent protective sheet segments 70 joined separably by hook-and-loop fasteners 72a, 72b. Making the protective sheet 30 dividable in this way facilitates the handling of the protective sheet 30, such as attachment and removal. Of course, the protective mat 20 may also be dividable.

[0043] 7, each protective sheet segment 70 is made by sandwiching a cushioned sheet material 70c, such as BELL POLLEN or MINAFOAM (registered trademark), between two surface materials 70a, 70b, such as tarpaulin, and joining the surface materials 70a, 70b by sewing or the like along the periphery of the sheet material 70c. If the surface materials 70a, 70b are shifted in the circumferential direction during the production of the protective sheet segment 70 and hook-and-loop fasteners 72a, 72b are provided at the shifted portions, when the protective sheet segment 70 is joined to the adjacent protective sheet segment 70, the surface of the joint is less uneven, making it less likely for workers' clothes to get caught or for dirt to get in.

[0044] The magnetic force source in the protective sheet 30 shown in Fig. 7 is a disk-shaped permanent magnet 74 such as a neodymium magnet, similar to the protective mat 20 in Fig. 6. This permanent magnet 74 can be installed by embedding it in a recess or through hole 76 provided in the sheet material 70c, but is not limited to this.

[0045] The protective cover 40 shown in Figs. 4 and 5 is made of a flexible sheet material such as tarpaulin in a bag shape, but as in the protective cover 40 shown in Fig. 8, the portions 80, 82 surrounding the flange portion of the manhole 110 may be made to have a certain degree of rigidity. In the case of a protective cover 40 having rigidity, the cover itself does not twist or bend, making installation very easy. In addition, a flame-retardant polyester twill 84 such as F2600 Ernest sold by Aotake Co., Ltd. extends in a skirt shape from the free edge of the cylindrical portion 82 of the protective cover 40. The opening of the twill 84 is provided with a string 44 with a fastener 46, as in the protective cover 40 shown in Figs. 4 and 5, making it easy to attach the protective cover 40 to the manhole 110 and adjust its position.

[0046] Also, for example, in the above embodiment, the protective mat 20 is fixed only to the lower inner surface of the manhole 110, but it is also possible to extend the entire length of the protective mat 20 so as to cover the entire circumference of the inner surface of the manhole 110.

[0047] Furthermore, the present invention is not limited to the manhole 110 of an oil storage tank, but can also be applied to manholes of other buildings or their equivalents. For example, in a building having a plurality of compartments, such as a nuclear reactor building, the present invention can be applied to a pipe that penetrates a wall separating the compartments as an equivalent of a manhole, so long as it is cylindrical and contains a magnetic material. The manholes to which the present invention is applicable are not limited to horizontal types, and since the curing mat 20 and / or the curing sheet 30 in the curing device 10 of the present invention can be attached by magnetic force, the present invention can also be applied to vertical manholes that extend vertically. [Explanation of symbols]

[0048] 10... protective device, 20... protective mat, 22... magnetic sheet of protective mat, 24... protective material of protective mat, 26... ear of protective mat, 30... protective sheet, 32... magnetic sheet of protective sheet, 34... protective material of protective sheet, 36... hook-and-loop fastener, 38... ear of protective sheet, 40... protective cover, 42... string passage, 44... string body, 46... string fastener, 48... window, 50 ...Gas hose, 52...Display unit, 54...Rain cover, 60...(Disc-shaped) permanent magnet, 70...Curing sheet segment, 70a, 70b...Surface material, 70c...Sheet material, 74...(Disc-shaped) permanent magnet, 76...Recess or through hole, 80, 82...Rigid part of curing cover, 84...Twill, 110...Manhole, 130...Gasket surface, 200...Side wall of storage tank (wall of building)

Claims

1. A covering device for use in a manhole including a magnetic material installed through a side wall of a building, A curing device for a manhole, comprising a curing mat that is attached to at least a portion of the inner surface of the manhole by magnetic force in a curved state that follows the curved shape of the manhole.

2. 2. The manhole protection device according to claim 1, further comprising an annular protection sheet that is attached to the periphery of one of the openings of the manhole by magnetic force so as to cover the gasket surface around the opening of the manhole.

3. A protective device for a manhole as described in claim 1 or 2, comprising a protective cover that is arranged to cover one opening of the manhole, and is configured to tighten the mouth of the protective cover with a string body with a string fastener provided at the mouth of the protective cover and fix the cover to the cylindrical portion of the manhole.

Images