Manhole cover frame structure

Abstract

The present invention provides a manhole cover frame structure that can reliably suppress the swing and rotation of a manhole cover relative to a manhole frame in a simpler way. The manhole cover frame structure (1) comprises: a manhole cover (2) having a rim hanging down at its periphery; and a manhole frame (3) having a fitting groove (30) for the rim (20) of the manhole cover (2) to fit in. The manhole cover frame structure (1) is characterized in that a prevention member (A) is provided on at least one of the rim (20) of the manhole cover (2) and the fitting groove (30) of the manhole frame (3). When the manhole cover (2) is fitted into the manhole frame (3), the prevention member (A) is broken and / or deformed, thereby preventing the manhole cover (2) from lateral movement relative to the manhole frame (3).

Description

Technical Field

[0001] The present invention relates to a manhole cover frame structure, which comprises: a manhole cover having an edge portion hanging down at its periphery; and a manhole frame having a fitting groove for fitting the edge portion of the manhole cover. Background Art

[0002] Generally, dimensional deviations may occur in manhole covers and manhole frames due to manufacturing errors during molding or thermal expansion and contraction caused by environmental conditions after construction. Therefore, the following design is proposed: when the manhole cover is inserted into the manhole frame in a manner that the manhole cover is tightly closed even with such dimensional deviations, a more or less gap will be generated between the edge of the manhole cover and the fitting groove of the manhole frame.

[0003] Manhole covers that require high load-bearing performance are heavy, and rarely swing sideways even if there is a gap between them and the manhole frame. However, in applications that do not require such high load-bearing performance, lighter manhole covers are used, and due to their lightness, the manhole covers are prone to swinging.

[0004] In particular, when the manhole cover is just installed on the manhole frame, the surrounding sand and gravel have not entered the gap, so there is rarely any mixing of foreign matter such as sand and gravel on the contact surface between the manhole cover and the manhole frame, or damage to the contact surface. Therefore, there is less friction, and the manhole cover is prone to swinging laterally when vibration is applied. Sometimes, the manhole cover will rotate in the circle due to external forces such as the force of the workers stepping on the manhole cover.

[0005] As a conventional method for suppressing the swing and rotation of the manhole cover, for example, Figure 7 The method shown is to stick a rubber sheet G or the like on the contact surface between the manhole cover and the manhole frame.

[0006] It should be noted that the existing anti-sloshing method of such manhole covers is widely known, but there is no appropriate literature, so the prior art literature is not disclosed.

[0007] According to the above-mentioned anti-swaying method of the manhole cover, the rubber sheet must be attached to the manhole cover manually, the assembly operation is time-consuming, and there is a risk of the rubber sheet falling off during transportation and construction after attachment. Summary of the invention

[0008] Problems to be solved by the invention

[0009] The object of the present invention is to provide a manhole cover frame structure which can reliably suppress the swing and rotation of the manhole cover relative to the manhole frame in a simpler way.

[0010] Solutions for solving problems

[0011] The manhole cover frame structure of the present invention is characterized in that it comprises: a manhole cover having a rim hanging down at its periphery; and a manhole frame having a fitting groove for the rim of the manhole cover to be fitted into, wherein a preventing member is provided on at least one of the rim of the manhole cover and the fitting groove of the manhole cover, and when the manhole cover is fitted into the manhole frame, the preventing member is broken and / or deformed, thereby preventing the manhole cover from lateral movement relative to the manhole frame.

[0012] According to the present structure, the edge of the manhole cover is tightly attached to the fitting groove of the manhole frame by preventing the member from being broken and / or deformed, and as a result, the swing and rotation caused by the lateral movement of the manhole cover relative to the manhole frame can be prevented. Therefore, there is no need to perform additional assembly work, and the swing and rotation of the manhole cover relative to the manhole frame can be reliably suppressed in a simpler way.

[0013] Preferably, in the manhole cover frame structure of the present invention, the shape of the preventing member is selected from the group consisting of a longitudinal rib shape extending in a radial direction, a longitudinal rib shape extending in a circumferential direction, and a cylindrical shape.

[0014] According to the present structure, the shape of the preventing member is more easily broken and / or deformed. Therefore, the part where the manhole cover or manhole frame contacts the preventing member due to manufacturing errors or thermal expansion, thermal contraction, etc. can be easily adhered by being broken and / or deformed. As a result, the swinging and rotation of the manhole cover relative to the manhole frame can be more reliably suppressed.

[0015] Preferably, in the manhole cover frame structure of the present invention, the preventing member is shaped like a longitudinal rib extending in a radial direction, and the preventing member is provided in a fitting groove of the manhole frame.

[0016] According to this structure, since the prevention member is provided in the fitting groove of the manhole frame, it can be applied to various manhole covers matching the specifications of the manhole frame, and the construction performance is excellent.

[0017] Preferably, in the manhole cover frame structure of the present invention, the prevention member is integrally provided when the manhole cover or the manhole frame is formed.

[0018] According to this structure, the prevention member is integrally formed on the manhole cover or the manhole frame, so there is no risk of the prevention member falling off during transportation or construction. Therefore, the construction performance is excellent and the manhole cover can be reliably prevented from swaying or rotating relative to the manhole frame.

[0019] Preferably, in the manhole cover frame structure of the present invention, the length of the preventing member in the radial direction of the manhole cover frame structure or the length of the radial width of the area where the multiple preventing members are located is the radial length of the manhole cover or the manhole frame equivalent to the dimensional deviation of the manhole cover or the manhole frame, and the dimensional deviation of the manhole cover or the manhole frame is caused by thermal expansion, thermal contraction, etc. caused by assumed manufacturing errors or environmental conditions after construction.

[0020] According to the present structure, even if dimensional deviations occur in the manhole cover or manhole frame due to manufacturing errors or thermal expansion, thermal contraction, etc. caused by environmental conditions after construction, the manhole cover or manhole frame can be kept in close contact with the prevention member by making the prevention member more reliably prevent it from being broken and / or deformed. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a three-dimensional diagram of the manhole cover frame structure.

[0022] Figure 2 A longitudinal cross-sectional view of a manhole cover frame structure in which the manhole frame is relatively small relative to the manhole cover

[0023] Figure 3 It is a longitudinal sectional view of the manhole cover frame structure in the case where the manhole frame is relatively larger than the manhole cover.

[0024] Figure 4 It is a perspective view showing another embodiment of the preventing member.

[0025] Figure 5 It is a perspective view showing another embodiment of the preventing member.

[0026] Figure 6 It is a perspective view showing another embodiment of the preventing member.

[0027] Figure 7 It is a longitudinal sectional view of an existing manhole cover frame structure.

[0028] Description of Reference Numerals

[0029] 1: Manhole cover frame structure; 2: Manhole cover; 20: Edge; 21: Inner inclined surface; 22: Outer inclined surface; 3: Manhole frame; 30: Fitting groove; 31: Radially inner side surface; 32: Radially outer side surface; 33: Bottom surface; 40: Gap (gap between the outer inclined surface 22 and the radially outer side surface 32); A: Longitudinal rib (an example of a prevention member); R1: Cover edge root (root portion of the edge 20 of the manhole cover 2); R2: Top end portion (top end portion of the longitudinal rib A); G: Rubber sheet; W: Radial width. DETAILED DESCRIPTION

[0030] [Implementation Method]

[0031] Hereinafter, embodiments of the present invention will be described.

[0032] like Figure 1 As shown, the manhole cover frame structure 1 of the present embodiment includes: a manhole cover 2; and a manhole frame 3 in which the manhole cover 2 is inserted.

[0033] The manhole cover 2 is a disc-shaped circular cover, and a rim 20 is suspended from the periphery thereof.

[0034] The manhole frame 3 is an annular frame, and a fitting groove 30 is formed on the periphery thereof. The manhole frame 3 is configured such that when the manhole cover 2 is mounted on the manhole frame 3 , the edge 20 of the manhole cover 2 fits into the fitting groove 30 .

[0035] The fitting groove 30 of the manhole frame 3 of the present embodiment is provided with a longitudinal rib A extending in the radial direction from the radially inner side surface 31 to the bottom surface 33. The longitudinal rib A of the present embodiment is integrally formed with the manhole frame 3, but the present invention is not limited to this structure.

[0036] The longitudinal rib A functions as a preventing member. When the manhole cover 2 is fitted into the manhole frame 3 , the longitudinal rib A is broken and / or deformed, so that the manhole cover 2 and the longitudinal rib A are in close contact, thereby preventing the manhole cover 2 from lateral movement relative to the manhole frame 3 .

[0037] like Figure 2 As shown, when the manhole frame 3 is relatively small relative to the manhole cover 2, the gap 40 generated between the outer inclined surface 22 of the manhole cover 2 and the radially outer side surface 32 of the manhole frame 3 is small, and the manhole cover 2 is not easy to swing laterally. In addition, in this case, the inner inclined surface 21 of the edge 20 of the manhole cover 2 is prevented from contacting the longitudinal rib A.

[0038] On the other hand, when the manhole frame 3 is relatively large relative to the manhole cover 2, a relatively large gap 40 may be generated between the outer inclined surface 22 of the manhole cover 2 and the radially outer side surface 32 of the manhole frame 3. As a result, especially when the manhole cover 2 is just assembled on the manhole frame 3, the surrounding sand and gravel do not enter the gap, so it is rare for foreign matter such as sand and gravel to mix into the contact surface between the manhole cover and the manhole frame, and the contact surface is damaged. Therefore, there is less friction, and when vibration is applied, the manhole cover 2 is easy to swing laterally, and sometimes the manhole cover is subjected to external forces such as the force of the operator stepping on the manhole cover and rotates in the circumferential direction.

[0039] However, according to the manhole cover frame structure 1 of this embodiment, Figure 3As shown, when the manhole cover 2 is assembled to the manhole frame 3, the inner inclined surface 21 of the edge 20 of the manhole cover 2 comes into contact with the longitudinal rib A. At this time, a part of the longitudinal rib A is broken by being cut away and / or a part of the longitudinal rib A is deformed, so that the edge 20 of the manhole cover 2 is closely attached to the fitting groove 30 of the manhole frame 3. As a result, the swing and circumferential rotation caused by the lateral movement of the manhole cover 2 relative to the manhole frame 3 are prevented.

[0040] The shape of the longitudinal rib A as the preventing member is preferably such that the inclination of the longitudinal rib A facing the inner inclined surface 21 of the edge 20 of the manhole cover 2 is the same as or steeper than the inclination of the inner inclined surface. When the manhole cover 2 is fitted into the manhole frame 3, the contact portion between the edge 20 of the manhole cover 2 and the longitudinal rib A becomes minimum, so that the edge 20 of the manhole cover 2 is easily inserted into the fitting groove 30 of the manhole frame 3 for positioning.

[0041] Preferably, the tip end R2 of the longitudinal rib A as the preventing member is formed in an arc shape. When the manhole cover 2 is fitted into the manhole frame 3, insertion becomes easier.

[0042] In addition, it is preferred that the shape of the cover edge root R1 of the edge 20 of the manhole cover 2 is formed into an arc shape, and the curvature of the cover edge root R1 of the edge 20 of the manhole cover 2 and the curvature of the top end R2 of the longitudinal rib A as the prevention member are R1>R2. When the manhole cover 2 is fitted into the manhole frame 3, the cover edge root R1 of the edge 20 of the manhole cover 2 contacts the top end R2 of the longitudinal rib A, and the top end R2 of the longitudinal rib A is broken and / or deformed and tightly attached by pressing the cover edge root R1, thereby reliably suppressing the manhole cover from swinging and rotating relative to the manhole frame.

[0043] It should be noted that the inner inclined surface 21 of the edge 20 of the manhole cover 2 may be textured to increase the friction coefficient. This makes it easier to prevent the manhole cover 2 from rotating.

[0044] Ideally, three or more longitudinal ribs A of the same shape are provided at equal intervals in the circumferential direction. Thus, when the manhole cover 2 is mounted on the manhole frame 3 , the manhole cover 2 can be easily fitted so that the central axis of the manhole cover 2 coincides with the central axis of the manhole frame 3 .

[0045] In addition, the width of the longitudinal rib A can be appropriately set according to the ease of being broken and / or deformed, etc., but the radial length of the longitudinal rib A is preferably set to a radial length of the manhole cover 2 or the manhole frame 3 that is equivalent to the dimensional deviation of the manhole cover 2 or the manhole frame 3, which is caused by thermal expansion, thermal contraction, etc. caused by assumed manufacturing errors or environmental conditions after construction. It should be noted that the maximum radial length of the longitudinal rib A is the length obtained by subtracting the radial length of the edge 20 of the manhole cover 2 from the radial length of the fitting groove 30 of the manhole frame 3.

[0046] As constituent materials applicable to the manhole cover 2 and the manhole frame 3 of the present invention, for example, synthetic resins such as polypropylene resin (PP) can be cited, but it is not limited to this as long as it can be configured so that the longitudinal rib A will be broken and / or deformed when the manhole cover 2 is assembled on the manhole frame 3.

[0047] (Other embodiments)

[0048] 1. In the above-mentioned embodiment, the longitudinal rib A extending in the radial direction is shown as the shape of the preventing member, but the shape is not limited to this shape as long as it can be broken and / or deformed when the manhole cover 2 is assembled to the manhole frame 3. In addition, for example, Figure 4 As shown, longitudinal ribs A extending in the circumferential direction are used, or as Figure 5 As shown in the figure, a structure with multiple longitudinal ribs A extending in the circumferential direction is adopted, or as Figure 6 The structure shown is provided with a plurality of cylindrical preventing members. Figure 5 and Figure 6 In the case of the structure shown, the length of the radial width W of the area where the multiple preventing components A are located is ideally set to a radial length of the manhole cover 2 or the manhole frame 3 that is equivalent to the dimensional deviation of the manhole cover 2 or the manhole frame 3. The dimensional deviation of the manhole cover 2 or the manhole frame 3 is caused by thermal expansion, thermal contraction, etc. caused by assumed manufacturing errors or environmental conditions after construction.

[0049] 2. In the above-mentioned embodiment, a structure is shown in which the longitudinal rib A as a preventing member is provided from the radially inner side surface 31 to the bottom surface 33 of the fitting groove 30 of the manhole frame 3, but the structure is not limited to this. The preventing member may be provided from the radially outer side surface 32 to the bottom surface 33 of the fitting groove 30 of the manhole frame 3, or the preventing member may be provided on both side surfaces of the fitting groove 30.

[0050] 3. In the above-mentioned embodiment, the structure in which the prevention member is provided in the fitting groove of the manhole frame is shown, but it is not limited to this structure, and the prevention member may also be provided in the edge of the manhole cover. In this case, for example, the prevention member may also be provided in the inner side, outer side or both sides of the edge of the manhole cover.

[0051] 4. The manhole cover frame structure of the present invention can be applied to the manhole of a septic tank, for example, and can be particularly suitably used in small septic tanks and medium septic tanks.

[0052] It should be noted that, as long as there is no contradiction, the structure disclosed in the above-mentioned embodiment (including other embodiments, the same below) can be used in combination with the structures disclosed in other embodiments. In addition, the embodiments disclosed in this specification are for illustration only, and the embodiments of the present invention are not limited thereto and can be appropriately changed without departing from the scope of the purpose of the present invention.

[0053] Industrial Applicability

[0054] The present invention can be suitably used in the technical field of suppressing the swaying and rotation of a manhole cover of a septic tank, for example.

Claims

1. A manhole cover frame structure, comprising: a manhole cover having an edge portion hanging down at its periphery; and a manhole frame having a fitting groove for the edge portion of the manhole cover to fit in, characterized in that: A preventing member is provided on at least one of the edge of the manhole cover and the fitting groove of the manhole cover, and when the manhole cover is fitted into the manhole frame, the preventing member is broken, thereby preventing the manhole cover from lateral movement relative to the manhole frame. The preventing member is integrally provided when forming the manhole cover or the manhole frame. The preventing member is in the shape of a plurality of longitudinal ribs extending in the radial direction or a plurality of cylindrical shapes extending in the radial direction.

2. The manhole cover frame structure according to claim 1, characterized in that: The preventing member is in the shape of a plurality of longitudinal ribs extending in the radial direction, and the preventing member is arranged in the fitting groove of the manhole frame.

3. The manhole cover frame structure according to claim 1 or 2, characterized in that: The radial length of the preventing member or the radial width of the area where the multiple preventing members are located is the radial length of the manhole cover or the manhole frame equivalent to the dimensional deviation of the manhole cover or the manhole frame, and the dimensional deviation of the manhole cover or the manhole frame is caused by thermal expansion, thermal contraction, etc. caused by manufacturing errors or environmental conditions after construction.

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