JP2006257733A - Fall prevention device for underground structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fall prevention device for an underground structure capable of securely receiving a load applied to the cover part thereof. <P>SOLUTION: This device is installed at the opening part of a receiving frame forming the underground structure to prevent a man and an article from falling into the opening. The device comprises a body 23 having the plate-like cover part 21 of such a size and shape that can cover the opening part 11 of the receiving frame 10 for preventing the man and the article from falling and support parts 24, 25, 26, 27, 28, and 29 formed at the peripheral edge part of the cover part 21 for mounting on the inside of the opening part 11. The support parts 24, 25, 26, 27, 28, and 29 are formed to be continuously supported, over a necessary length, on a receiving part 12 formed on the inside of the opening part 11 to receive the load applied to the cover part 21 of the body 23. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an apparatus that is attached to an opening of a receiving frame constituting an underground structure and prevents a person or an object from falling into the opening.

  There are various types of instruments and devices that prevent people and objects from falling into openings such as manholes, and there are differences in their specific shapes, but a lattice or net structure is fundamental. It can be said that it is a thing. These fall prevention devices are supported on the receiving frame of the underground structure by several locking parts, and each locking part is partial, so when a human fall accident etc. occurs, the load is On average, it is difficult to add, and since it is often offset, the load cannot be supported, and there is a risk that sufficient safety cannot be ensured. Furthermore, in order to withstand the corrosive environment caused by hydrogen sulfide gas or the like in the manhole, it is more difficult to endure a heavy load in the case of those made of a corrosion-resistant synthetic resin.

  On the other hand, the falling prevention lids of Japanese Utility Model Laid-Open Nos. 4-138441, 10-338942, or 11-131512 are provided with several mounting seats at equal intervals, and the load is applied almost evenly. Conceivable. However, since the string facing the center side of the receiving frame is provided in a straight line perpendicular to the center line of the receiving frame as the mounting seat in the above case, there is a problem that the effective diameter of the receiving frame is narrowed. The effective diameter is defined as the inner diameter of the opening at the lower end of the receiving frame. However, in the above invention, the mounting seat is smaller than the effective diameter of the receiving frame. For example, even with a nominal 600φ, the effective diameter of 600 mm is actually insufficient. Things will happen.

In addition, as seen in Japanese Patent Application Laid-Open Nos. 2001-20307, 2002-61214, 2003-206543, etc., pebbles, bolts, nuts, etc. fall into the manhole when the lattice or mesh is large. Therefore, there is a risk that equipment such as a pump in the downstream pump chamber may be damaged. It is possible to prevent the fall of pebbles and the like by using an inner lid for heat insulation together with the fall prevention device, but the outside light is blocked and the work in the manhole is obstructed, so lighting is necessary and a power supply is secured. There are new problems that must be done. Also, this type of device is designed to be attached and detached from the outside, so if you have to work alone, take time to remove the device and get out when you are in the manhole. become.

Utility Kaihei 4-138441 JP 10-338942 A JP-A-11-131512 JP 2001-20307 A JP 2002-61214 A JP 2003-206543 A

  This invention is made paying attention to the said point, The subject is providing the fall prevention apparatus for underground structures which can receive reliably the load added to the cover part of a fall prevention apparatus. Another object of the present invention is to provide a fall prevention device for an underground structure that does not reduce the effective diameter of the receiving frame and has a more suitable performance for use during work in a manhole.

In order to solve the above-mentioned problems, the present invention is a device that is attached to the opening of a receiving frame constituting an underground structure and prevents a person or an object from falling into the opening. And a main body having a plate-like cover portion having a size and a shape covering the opening portion of the receiving frame and a support portion provided at a peripheral edge portion of the cover portion for mounting inside the opening portion. In order to receive the load applied to the cover part of the main body, the part is provided so as to be continuously supported over the required length on the receiving part provided inside the opening, and the main part of the receiving part is Means are provided that are provided outside the portion that defines the effective diameter of the receiving frame and substantially at the bottom of the receiving frame.

  The fall prevention device according to the present invention is attached to an opening of what constitutes an underground structure such as a so-called manhole or handhole, and a person or an object is placed inside the opening while the lid is opened. Is a device that prevents falling or falling. Therefore, this fall prevention device requires a plate-like cover as a means for covering the opening of the receiving frame in order to prevent a person or an object from falling, and the support as a means for attaching the cover to the inside of the opening. I need. The reason why the cover is attached to the inside of the opening is to close the opening with a cover while the main body is attached when not in use.

The covering portion in the present invention is not a lattice shape or a net shape but a plate shape. It is because it can receive a pebble, a bolt, a nut, etc. by being plate-shaped, and can prevent falling into an underground structure. The material is not limited, but either synthetic resin or metal is dominant for ease of manufacture. A support part is provided in the peripheral part of a cover part, and comprises a main body united with a cover part. The part corresponding to the conventional support part is generally partially supported by a receiving seat on the receiving frame side, and when a load is applied to the cover part, the point-like locking part cannot withstand the load and comes off. In the present invention, a wide range of support portions that are continuous in a line shape rather than a dot shape are provided.

  In other words, the support part receives the load applied to the cover part and transmits it to the receiving part, which is a receiving seat on the receiving frame side, so that it is in contact with the receiving part for the necessary length so as to disperse the load without concentrating it. It has been. It is also necessary for the support portion to be able to receive the load of the fall accident evenly in almost the entire region of the entire circumference of 360 degrees. Accordingly, the mechanical conditions required for the support portion are such that the load can be continuously received in a linear manner and transmitted to the receiving portion, and the load can be evenly distributed over almost the entire circumference of 360 degrees. The load applied to the main body can be dispersed without being concentrated on a specific number of points, and can be received with certainty.

  The receiving portion uses a structural portion provided inside the opening of the receiving frame. For example, a structure that can be used as a receiving portion such as an inner protruding edge provided on the lower surface of the receiving frame or in the vicinity thereof and protruding inward or a handle provided inside the opening. Corresponds to the part. The other part that can be a receiving part is a part that is provided at the opening of the receiving frame as a lid receiving part and can bear a load from above. For example, in a receiving frame for a tapered iron lid that receives the tapered surface of the outer periphery of the lid, There is a part that has a receiving piece to stop the biting of the iron lid. For example, in the case of the embodiment in which the handle is set symmetrically and the support part is set at the opposite part and three parts in the middle, the linear support part is dispersed in a total of six places, and an almost equal load is realized. It becomes possible. Among these receiving portions, the main portion is provided outside the portion that defines the effective diameter of the receiving frame and substantially at the lowest part of the receiving frame, thereby preventing the effective diameter of the receiving frame from being reduced. The main part of the receiving part that achieves this purpose corresponds to an inner protruding edge provided at the lowermost part of the receiving frame. Further, the main part means the main part in the receiving part, and the ratio of all the receiving parts is the largest.

  When the main body is formed of a material that is not transparent, in the state where the main body is attached to the inside of the opening, a large number of through-holes that can be used for light can be formed in order to obtain an illuminance that allows work to be performed inside the opening Can do. If the hole diameter is too large, it will be disadvantageous to stop the fall of pebbles, etc. Conversely, if it is too small, it will tend to block the light, and the number of holes must be increased significantly, so it is necessary to find the compromise is there. In the present invention, within 300 750 lux, which is required for visual work in general manufacturing processes, within the JIS regulations on factory illuminance standards, at least 300 lux is located at a depth of 2 m in the manhole during the spring day. The total area of all the through holes was set with the goal of being obtained in An obstruction stopper can be attached to the through-hole to be lighted so that part or all of the obstruction plug can be obstructed, thereby preventing entry of objects, rain, sewage, and the like.

  The main body can be provided with a handle for gripping the main body by hand so as to allow the fall prevention device to be removed from the inside of the opening. Since the handle can be grasped by hand from the inside, the fall prevention device can be securely attached to the receiving frame and removed without difficulty. In addition, the main body can be provided with a reflecting plate in a covering portion or other places to take measures to avoid danger by informing the presence of the opening. For this purpose, the entire main body may be colored with yellow or red. Although the fall prevention device having such a structure can be manufactured as a plastic molded product, it is effective to equip each part with means for improving the structural strength, thereby withstanding the load applied to the main body, and It can be communicated to the receiving frame. In addition to the strength improving means, it is also effective to have a detent means for stopping the support part from moving from the receiving part as the main body is deformed by a load.

  Since the present invention is configured and operates as described above, the load applied to the cover part of the fall prevention device is transmitted to the receiving part on the receiving frame side by the support part provided over the required length. Can be dispersed without concentrating them at a specific location, and the fall prevention device can reliably prevent the fall of a person or an object, and does not reduce the effectiveness of the receiving frame. Further, according to the present invention, it is possible to obtain the illuminance necessary for the work in the manhole, and even one person can attach the apparatus, and an opening on the ground for passersby etc. Therefore, it is possible to show more suitable performance for use during work in a manhole.

  Hereinafter, the present invention will be described in more detail with reference to the illustrated embodiments. FIG. 1 shows a fall prevention device 20 according to the present invention, and FIG. 2 shows that it is attached to a receiving frame 10 of an underground structure. The illustrated one has a plate-like cover portion 21 having a size and a shape covering the opening portion 11 of the receiving frame 10, and a rising portion 22 is provided at the peripheral portion thereof, so that the whole is three-dimensionalized as a dish-shaped structure. , Increase the structural strength. On the outside of the rising part 22 around the cover part 21, support parts 24... Divided into several parts are provided. The main body 23 is configured as a whole including the cover portion 21, the rising portion 22, and the support portions 24.

  The first support portions 24 and 25 are provided with the upper surface of the inner projecting edge 13 provided substantially over the entire circumference so as to protrude inward near the lower surface in the opening of the receiving frame 10 as a stop portion 12. Locked (see FIG. 9). The inner projecting edge 13 is provided at almost the lowermost part of the receiving frame 10 over almost the entire region and is the main part of the receiving part. Therefore, the inner protruding edge 13 is a place for supporting the first support parts 24 and 25 over the widest range. The effective diameter of the illustrated receiving frame 10 is the inner diameter of the inner projecting edge 13. The support parts 24 and 25, which are the first parts of the support parts, are provided on the outer periphery of the rising part 22 of the main body 23 so as to protrude outward and over a required length along the circumferential direction. Part. As shown in FIG. 3B, the first support portions 24, 25 have an arc shape and have a central angle a in the range of about 50 degrees facing the device for locking the lid. Are provided symmetrically at two locations (see FIG. 7).

  The support portions 26 and 27 as the second portion are provided on the upper surface of the main body 23 over the required length substantially along the circumferential direction with the upper end of the rising portion 22 of the main body 23 as the outer edge. As illustrated in FIG. 7, the illustrated second support portions 26 and 27 are linear portions extending about 40 degrees with respect to the central angle b, and are provided in two symmetrical directions. The receiving part 12 that locks the second support parts 26 and 27 uses the upper surface of the handle 14 provided on the left and right sides of the hinge part of the receiving frame 10 (see FIGS. 7 and 9).

  The support portions 28 and 29 as the third portion are provided on the left and right of the central portion of the main body 23 in a shape protruding outward from the upper surface of the main body 23 following the upper end of the rising portion 22 ( 5), the central angle c is about 10 degrees, and it is locked to the receiving frame side over a required length. Although this is the shortest in the embodiment, the receiving portion 12 is the upper surface of the inner peripheral edge 16 in which the receiving piece 15 is provided on the taper iron lid receiving frame 10, and a plurality of the receiving portions 12 may be provided (see FIG. 7, see FIG.

  Such a support structure reaches about 180 degrees, which is a half of the entire circumference of 360 degrees, by the total of the first support parts 24 and 25 and the second support parts 26 and 27, and the third support part. 28, 29 and over the range of about 200 degrees, and also the first support portions 24, 25 on the lock portion side of the opening 11, the third support portions 28, 29 on the center left and right, and the left and right on the hinge portion side. Several second support portions 26 and 27 are provided in an evenly distributed manner. These several support portions are symmetrical with respect to a center line that is provided in the opening 11 of the receiving frame 10 of the underground structure and connects the hinge portion 17 and the lock portion 18 for fixing the iron lid. Are arranged as follows. The main body 23 has a solid three-dimensional structure as a whole, including a recess 31 that avoids conflict with the lock portion 18 and a notch 32 that avoids conflict with the hinge portion 17. When a load due to a fall accident is applied, deformation is prevented by the strength improving means, and the inner protrusion edge 13 as the receiving portion 12 of the receiving frame 10 is not displaced by the shifting preventing means with respect to the receiving frame 10. In this configuration, the handle 14 and the inner peripheral edge 16 are transmitted. In the embodiment as a strength improving means, a plurality of ribs 22a are formed on the lower surfaces of the first support portions 24 and 25, and falling edges 22b are provided on the periphery of the support portion to form a three-dimensional structure. Box-shaped ribs 22c are provided for each piece, and a step portion 22d is formed between the main body covering portion 21 and the second support portion-side raised portion to enhance rigidity. One of the detent means is the second support portions 26 and 27 that are locked to the handles 14 and 14, and the other detent means is formed in the thick part of the first support portions 24 and 25. The locking opening 19a is engaged with a protrusion 19b protruding on the inner protruding edge 13 of the receiving frame 10. See FIGS. 10 and 11E.

  Further, the cover portion 21 of the main body 23 is provided with the through holes 33 penetrating the plate surface almost uniformly over the entire surface, thereby providing light. The illustrated through-hole 33 is opened based on the results of experiments in the Kanto region during the daytime afternoon in spring, so that the illuminance at a point 2 meters deep from the opening 11 is 300 lux. This corresponds to a through hole 33 having a hole diameter of 15 millimeters and having an opening of about 20 percent of the area of the opening 11. This is an example, and it is free to raise or lower the illuminance. Therefore, considering the fact that the experiment was in spring, especially when the conditions in the Tohoku region are more important than the winter or Kanto region. However, it may be necessary to increase the aperture ratio, and conversely if the conditions in the southwest direction are more important than in the summer or Kanto region, it will be necessary to decrease the aperture ratio. A blocking plug 41 can be assembled in the through-hole 33 (see FIG. 12). The closing plugs 41 may be assembled one by one in one through hole 33 or may be assembled so as to block a plurality of through holes 33 together.

The main body 23 is provided with handles 35 and 36 for grasping by hand. Handle 35, 36
Is provided so that a hand can be inserted and grasped by providing penetrating portions 37 and 38 reaching the upper end of the rising portion 22 at a location where the concave portion 31 and the notch portion 32 are provided. The handles 35 and 36 are provided around the diametrical ends of the main body 23 so that the operator can hold the main body 23 using both hands. Further, a reflection plate attachment portion 39 is formed on the cover portion 21 of the main body 23, and a separate reflection plate 40 is attached thereto (see FIGS. 2, 7, and 11D). Further, the main body 23 is colored yellow to improve the overall visibility.

  The state in which the fall prevention device 20 of the present invention is mounted on the receiving frame 10 is shown in FIG. 7 and subsequent figures. FIG. 7 is a cross-sectional view of FIG. 7, and FIG. Respectively. 7, the opening 11 of the receiving frame 10 is entirely covered with the main body 23 of the device of the present invention except for both sides of the hinge portion. The main body 23 includes the first support portions 24 and 25 and the second support portion. 26, 27 and the third support portions 28, 29 are supported by a wide range of linear continuous contact in a range of about 200 degrees, which covers 55 percent of the entire circumference of 360 degrees, and maintain stability against external forces. You can see that That is, the first support portions 24 and 25 having a central angle a of about 50 degrees are supported by the inner projecting edge 13 which is the main portion of the receiving portion 12 near the lower surface of the receiving frame as shown in FIGS. 9 and 11A. The second support portions 26 and 27 having a central angle b of about 40 degrees are supported by the handle 14 as shown in FIGS. 9 and 11B, and the third support portions 28 and 29 are the first and second support portions. 24, 25, 26, 27 is supported by the inner peripheral edge 16 of the receiving frame 10 at a central angle c of about 10 degrees (FIGS. 9 and 11C), and a load caused by a fall accident that will be applied to the main body 23, It is supported continuously at the periphery of the main body.

  The fall prevention device 20 of the present invention can be implemented as described above, has strength improvement means and slip prevention means, and receives the load of the fall accident almost uniformly around the entire circumference of the receiving frame 10. In particular, the linear first support portions 24 and 25 and the second support portions 26 and 27 that are in a wide range achieve even distribution of the load, and the second support portions 26 and 27 and the handle 14, 14 and the locking portions of the locking port 19a and the protrusion 19b serve to prevent slippage and withstand destruction even when subjected to a heavy load. The fall prevention device 20 according to the present invention can be made of a high strength material made of plastic, and the through hole 33 provided in the cover portion 21 is made of pebbles by setting the hole diameter and pitch to 10 to 15 millimeters. Can be effectively prevented, and the operation without artificial lighting in the manhole is also guaranteed.

  In the present invention, the main portion of the receiving portion is provided outside the portion that defines the effective diameter of the receiving frame and substantially at the lowermost portion of the receiving frame, and supports the first support portions 24 and 25 there. The diameter is not impaired, and it does not interfere with people coming and going. Moreover, since the main part of the receiving part 12 is provided in the lowest part of the receiving frame 10, the fall prevention apparatus 20 will be arrange | positioned in the lowest position, and since a large space can be taken in upper part, it interferes with a cover body back surface. There is a feature that does not occur.

The perspective view which shows one Example of the fall prevention apparatus for underground structures which concerns on this invention. The perspective view which attached the apparatus of FIG. 1 to the receiving frame. A is a rear view of the main body of the apparatus of FIG. 1, B is a plan view, and C is a front view. The IV-IV sectional view taken on the line of FIG. 3B. The VV sectional view taken on the line of FIG. 3B. FIG. 2 is a bottom view of the main body of the apparatus of FIG. 1. The top view which shows the state which attached the apparatus of FIG. 1 to the receiving frame. VIII-VIII sectional view taken on the line of FIG. IX-IX sectional view taken on the line of FIG. XX sectional drawing of FIG. 9A is an enlarged cross-sectional view of a portion A in FIG. 9, B is a portion B in FIG. 9, C is a portion C in FIG. 8, D is a portion D in FIG. 9, and E is a portion E in FIG. Sectional drawing of the main body of the apparatus of FIG. 1 which shows the state which assembled | attached the obstruction | occlusion stopper.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Receiving frame 11 Opening part 12 Receiving part 13 Inner projecting edge 14 Handle 16 Inner peripheral edge 20 Fall prevention device 21 Cover part 22 Standing part 23 Main body 24, 25 First support part 26, 27 Second support part 28, 29 Third Supporting part 33 Through hole 35, 36 Handle 40 Reflecting plate 41 Blocking plug

Claims (7)

A device that is attached to the opening of the receiving frame that constitutes the underground structure and prevents people and objects from falling into the opening, and is large enough to cover the opening of the receiving frame to prevent the falling of people and objects. A body having a plate-like cover having a thickness and a shape, and a support provided on the periphery of the cover to be attached to the inside of the opening, the support being a load applied to the cover of the body In order to receive, the receiving part provided inside the opening is continuously supported over a necessary length, and the main part of the receiving part is outside the portion defining the effective diameter of the receiving frame and the receiving frame. A fall prevention device for underground structures, characterized in that it is provided almost at the bottom. The catching portion includes an inner protruding edge provided inward near the lower surface of the receiving frame and a handle provided on the inner side of the opening, which are substantially along the circumferential direction of the opening. The fall prevention device for an underground structure according to claim 1, wherein the fall prevention device has a shape. 2. The structure according to claim 1, wherein in a state where the main body is attached to the inside of the opening, in order to obtain an illuminance capable of working inside the opening, a plurality of through-holes to be lighted are formed. Fall prevention device for underground structures. 4. The underground structure according to claim 3, wherein a total area of all the through holes is set so that the through holes are formed in the cover portion, and the illuminance at a point 2 meters deep from the opening is at least 300 lux. Fall prevention device. 2. The fall prevention device for an underground structure according to claim 1, wherein a handle for grasping by a hand is provided so as to penetrate the main body so that the main body can be removed from the inside of the opening. 2. The fall prevention device for an underground structure according to claim 1, wherein a reflecting plate for notifying the presence of the opening is provided in a cover part or other part of the main body. 2. The fall prevention device for an underground structure according to claim 1, further comprising a blocking plug that can be assembled to the through hole in order to block a part or all of the through hole that serves as a light for the cover portion of the main body.

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