JP3207911U - Mortar leakage prevention jig - Google Patents

Abstract

To provide a mortar leakage preventing jig capable of effectively preventing leakage of mortar before curing in mortar placing work in manhole cover receiving frame installation work. A mortar leakage preventing jig includes an annular ring formed by bending a strip-shaped steel plate into an annular shape, and a pantograph type screw jack structure expander / contractor provided inside the annular ring. The expansion / contraction end portions 21 of the expansion / contraction device 20 are fixed in the vicinity of both ends of the circular ring 20 so that the diameter of the annular ring 20 can be expanded and contracted. The handle 12 is provided at at least three locations inside the ring 10. [Selection] Figure 7

Description

  The present invention relates to a jig for preventing leakage of mortar before curing in a mortar placing process in which a ring-shaped receiving frame of a manhole cover is installed at the upper end of a lower heel.

In general manholes, as shown in a schematic cross-sectional view of FIG. 1, a receiving frame for placing a manhole cover is installed and fixed in an upper end opening portion of a concrete underlay buried in the ground. The structure of the lower arm is generally standardized, and the upper end opening is horizontal in principle. However, in order to adapt the manhole cover to the level and inclination angle of the ground such as roads, the receiving frame has a plurality of height adjustment bolts. Is attached to the upper end surface of the lower collar with a necessary inclination angle. Then, the receiving frame is installed and fixed to the lower rod by filling the space between the receiving frame and the upper end surface of the lower rod with mortar and curing it. After that, backfilling and pavement around the lower iron are performed, and only the ring portion of the receiving frame is exposed on the pavement surface.

FIG. 2 is a schematic view of an example of a popular receiving frame, and FIG. 3 is an enlarged schematic cross-sectional view of an example of a mounting position of the receiving frame on the upper end surface of the lower eyelid. In FIG. 3, G1 indicates a pavement surface, G2 indicates an installation position of the receiving frame, G3 indicates an upper end surface of the lower arm, and a space between G1 and G2 is embedded with a pavement material. The height between G2 and G3 is adjusted by adjusting bolts as necessary, and the loaded mortar is cured to support the load on the receiving frame. Also, the mortar is filled from a plurality of holes provided in the receiving frame through a hole that is not provided with a height adjusting bolt.

In recent years, as the structure and shape of the receiving frame and the height adjustment bolt have been improved, products with high fluidity, ultra-high strength, and non-shrinkable mortar have become widespread. Due to the high fluidity, it is possible to easily flow into even a small gap during filling and to perform uniform filling. The ultra-fast strength shortens the curing time and improves the compressive strength. Due to the non-shrinkage, there is no shrinkage after curing as in a conventional mortar in which cement and fine aggregate (sand) are kneaded with water, so that there is no gap between the receiving frame and the lower iron, and the adhesion is improved.

By the way, as shown in FIGS. 4 to 6, mortar filling is performed by sealing the inner and outer side surfaces of the height adjustment space between the receiving frame and the lower collar with a belt-shaped urethane foam after adjusting the height of the receiving frame. The urethane foam is removed after the mortar is cured. At this time, the outer foam is wound around the outer periphery of the height adjusting space and then fixed with an adhesive tape. Further, the outer peripheral surface can be bound by a belt, so that leakage of mortar before curing can be sufficiently prevented. However, as shown in FIG. 4, the inner foam is in close contact with the inner peripheral surface of the height adjustment space by the elasticity of urethane itself, but is not sufficiently crimped. As described above, since the high flow mortar easily penetrates into a small gap when filling, as shown in FIG. 6 (4), the lower end of the soft inner foam is bent due to the weight of the mortar itself. There was a problem that mortar easily leaked from the gap.
Hinoide Water Supply Equipment Co., Ltd. Home Page> Product Information> “Hijuster (registered trademark)”> Product Features URL: http://www.hinodesuido.co.jp/solution/city/productinformation/sewer/sewerhj.html

If a cavity is formed in the height adjustment space after curing due to leakage of the mortar, the load bearing strength of the receiving frame is lowered, and the mortar and the paving material are damaged, thereby aging is accelerated. For this reason, the installer has so far tried to take urgent measures to prevent leakage of mortar, such as by inserting a stick of wood or bamboo inside the receiving frame to support the inner surface of the inner foam. It was difficult to completely prevent leakage.

  The present invention was created in view of the above points, and provides a mortar leakage prevention jig that can effectively prevent leakage of mortar before curing in mortar placement work in manhole cover frame installation work. The task is to do.

  In order to solve the above-mentioned problems, the invention described in claim 1 is characterized by comprising an annular ring whose diameter can be expanded and contracted, and an expander / contractor provided inside the annular ring. Unlike the outer foam, which can be fixed with a belt, etc., the inner foam is in close contact with the height adjustment space between the receiving frame and the lower collar only by the elasticity of the urethane itself. This is the cause of leakage. According to the configuration of the present invention, the diameter of the annular ring that is in contact with the entire inner periphery of the inner foam is expanded by the expander / contractor, and the lower end of the inner foam is brought into close contact with the inner wall of the lower collar, thereby effectively mortaring. Can prevent leakage. In addition, after the mortar is cured, it can be easily removed by shrinking the diameter of the ring with an expander.

  Further, the invention described in claim 2 is the mortar leakage preventing jig according to claim 1, wherein the ring is formed by bending a strip steel plate into an annular shape, and the expander is a pantograph screw jack. The both ends of the said strip steel plate were each fixed to each expansion / contraction end part of this. As the circular ring, a strip-shaped steel plate having a width that does not deeply penetrate into the inner foam inner surface when expanded is suitable, but the material is not necessarily limited to steel. A pantograph type screw jack as an expander / contractor has a structure similar to that of a simple manual tire replacement jack mounted on an automobile, and is originally applied to expand or contract in the horizontal direction what is vertically expanded or contracted. The hydraulic system and the electric system can be applied, but the configuration of the present invention is as light and bulky as possible, considering that it should be used in a narrow work space in the manhole and that it must be held so that it will not fall until expansion is completed. Is preferred.

  Further, the invention described in claim 3 is a jig for preventing leakage of mortar according to claim 1 or claim 2, wherein the horizontal portion protrudes outside the ring and is adjustable in height. The handle is provided in at least three places inside the ring. The handle improves the convenience of carrying the mortar leakage prevention jig and handling it when installed in a manhole, and hooks a substantially inverted L-shaped horizontal part protruding outside the ring onto the upper surface of the receiving frame. Even if the operator does not hold it, the ring before expansion or after contraction can be prevented from falling into the manhole. In addition, since the handle is configured to be adjustable in height, by setting and fixing the handle height according to the distance from the upper surface of the receiving frame to the position where the annular ring is in close contact with the inner foam inner surface, Immediately after inserting the ring into the receiving frame, the inner form can be fixed by expanding the ring with an expander.

  According to the jig for preventing leakage of mortar according to the present invention, in the mortar placement work in the manhole cover receiving frame installation work, it is effective that the filled mortar leaks from the gap between the inner foam and the inner wall of the lower arm. Can be prevented. It can be manufactured at a low cost with an extremely simple structure, and the ring can be expanded and contracted simply by manually rotating the expander screw, so that no special skill or experience is required. Further, since a stick or the like is not used in the manhole, even if this jig is applied, it does not become an obstacle to the person entering and exiting the manhole.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. 7 is a perspective view showing a configuration of a mortar leakage preventing jig according to an embodiment of the present invention, FIG. 8 is a plan view thereof, FIG. 9 is a side view thereof, and FIG. 10 is an application state of the mortar leakage preventing jig. FIG. The mortar leakage preventing jig 1 includes a ring 10 formed by bending a belt-shaped steel plate in an annular shape, an expander / contractor 20, and three substantially inverted L-shaped handles 12. The expander / contractor 20 is a pantograph screw jack, and both ends of the ring 10 are fixed to the respective expansion / contraction end portions 21. Both ends of the strip-shaped steel plate of the ring 10 are overlapped without being connected, and when the expanding / contracting end portion 21 is expanded in the horizontal direction by manually rotating the rotating portion 22 at the upper end of the expanding / contracting device 20 with a bar or the like, the overlapping portion 11 opens and the diameter of the ring 10 expands. Further, the handle 12 can be fixed at an arbitrary height by inserting a vertical portion into a tubular handle mounting portion 13 provided on the inner surface of the annular ring 10, and using a retaining screw 14.

  During construction, after adjusting the height of the receiving frame with the adjusting bolt, cover both the inner and outer sides of the height adjustment space between the receiving frame and the lower arm with inner foam and outer foam. Secure with. On the other hand, the handle 12 of the mortar leakage preventing jig 1 is fixed with a retaining screw 14 at a height that matches the distance from the upper surface of the receiving frame that has been measured in advance to the position where the annular ring is in close contact with the inner surface of the inner foam. At that time, the horizontal portion of the handle 12 is fixed at a position protruding toward the outside of the ring 10.

Next, the annular ring 10 is inserted into the receiving frame by holding the handle 12, and the annular mortar leakage preventing jig 1 is placed in an appropriate position by hooking the handle 12 on the upper surface of the edge of the receiving frame. Retained. Then, the rotating portion 22 is rotated by a bar or the like to bring the annular ring 10 into contact with the inner foam, and further, the diameter of the annular ring 10 is expanded until the inner foam is appropriately adhered to the inner wall of the lower eyelid.
Thereafter, the mortar is filled and cured as usual. After the curing, the rotating part 22 is rotated in the reverse direction to contract the diameter of the annular ring 10, the handle 12 is held, the mortar leakage preventing jig 1 is removed from the receiving frame, the inner and outer urethane foam is removed, and the process is completed.

  As mentioned above, although embodiment of this invention was described referring drawings, this invention is not necessarily limited only to the structure mentioned above, In the range which achieves the objective of this invention and has an effect, suitably As long as they can be modified and fall within the scope of the technical idea of the present invention, they belong to the technical scope of the present invention.

The jig for preventing leakage of mortar according to the present invention can be used in mortar filling and placing work in manhole work, and contributes to improving the efficiency of work for curing mortar using urethane foam and improving work quality.

It is a section schematic diagram showing the structure of a general manhole. 1 is a schematic view of an example of a receiving frame for a manhole cover that is commonly used. It is the cross-sectional schematic which expanded an example of the attachment location of the receiving frame to a lower collar upper end surface. It is the schematic which shows the attachment method of the inner foam to inner and outer urethane foam and a receiving frame. It is the schematic which shows the filling method of the mortar after inner and outer form attachment. It is a cross-sectional schematic diagram which shows the leakage of the mortar in the operation process by a prior art. It is a perspective view which shows the structure of the jig | tool for mortar leak prevention which concerns on embodiment. It is a top view of the jig for prevention of mortar leakage concerning an embodiment. It is a side view of the jig for prevention of mortar leakage concerning an embodiment. It is a side view which shows the application state of the jig | tool for mortar leak prevention which concerns on embodiment.

1 Mortar Leakage Prevention Jig 10 Ring 11 Overlap 12 Handle
13 Handle mounting portion 14 Retaining screw 20 Expander / contractor 21 Expanding / contracting end portion 22 Rotating portion 23 Jack screw

Claims (3)

A mortar leakage prevention jig used in a mortar placing work in which a receiving frame of a manhole cover is installed at the upper end of the lower arm,
A jig for preventing leakage of mortar, characterized by comprising an annular ring whose diameter can be expanded and contracted and an expander / contractor provided inside the annular ring.   The annular ring is formed by bending a belt-shaped steel plate into an annular shape, and the expander / contractor is a pantograph screw jack, and both ends of the strip-shaped steel plate are fixed to respective expansion / contraction end portions of the expander / contractor. The jig for preventing mortar leakage according to claim 1. 3. The height-adjustable substantially inverted L-shaped handle having a horizontal portion protruding outside the ring is provided at at least three positions inside the ring. The mortar leakage preventing jig according to any one of the above.