JPH0330474Y2 - - Google Patents

Description

[Detailed Description of the Invention] <Industrial Field of Application> The present invention relates to a segment grout hole plug that is attached to a concrete segment used in a tunnel using the shield method.

<Prior art> Conventionally, a generally used grout hole plug installed in a concrete segment consists of a plug body with a threaded part and a flange part, and a simple rubber layer on the flange part, as shown in Fig. 4. It adopts a structure in which an O-ring made of etc. is mounted. In this case, the O-ring simply uses a gasket interposed between the flange and the end of the socket, so it cannot be installed stably. Therefore, if the plug body is strongly tightened to improve water-stopping properties, the O-ring may become twisted. Therefore, a reliable water-stopping effect cannot be obtained. Therefore, in conventional devices, even if the water pressure on the socket side is slight, the O-ring deforms and water comes out. This becomes a problem especially when construction is carried out deep underground, which is subject to large underground water pressure, such as in recent subway construction. Furthermore, since the O-ring of the plug configured as described above is unstable, an extremely large torque must be applied to obtain a predetermined squeezing margin, and this poses a problem in workability.

<Problems to be Solved by the Invention> In view of the above-mentioned circumstances, the present invention aims to provide a segmented grout hole plug with high water-stopping properties, with the aim of stably attaching an O-ring.

<Means for solving the problem> The present invention is a plug that is screwed into a grout hole socket embedded in the concrete segment body used in the shield construction method, and has a screw-in part that screws into the grout hole and the base end of the plug. In addition to forming a plug body with a flange portion and a photographing portion, a groove for an O-ring is carved in a tapered flat portion provided at the base of the threaded portion, and an O-ring is fitted into the groove. The plug is designed to prevent the ring from slipping.

<Example> Hereinafter, the present invention will be described in detail based on the drawings of the example.

1 is a threaded part 2 having a predetermined thread, and a flange part 4 having a tapered countersunk part 3 at its base.
and a rectangular photographing part 5 at the center of the back of the flange part 4.
The plug body is made of synthetic resin and has an O-ring groove 6 annularly carved in the taper intermediate position of the platen part 3 of the plug body 1, and an O-ring made of rubber or the like. The ring 7 is fitted to form a grout hole plug 8 as a whole. In this case, the depth of the O-ring groove 6 is such that the O-ring 7 can protrude by about 1/3 to 1/2 (cross section) and has a predetermined width of crushing allowance. Incidentally, the diameter of the O-ring 7 may be smaller than the conventional one.

To explain this function now, first, like a conventional plug, the threaded part 2 is screwed into a grout hole socket 9 placed in a concrete segment A constructed on a tunnel road. In this case, the pick-up portion 5 at the end of the flange portion 4 may be turned by finger or may be turned using a tightening tool (not shown).

Here, even if the screw-in part 2 is screwed in and the O-ring 7 of this countersunk part 3 comes into contact with the mouth edge of the socket 9, the O-ring 7 is fitted into the groove 6.
It has good stability against screw insertion and does not give unnecessary twisting action to the O-ring 7. Of course, since the inner taper 10 having the same slope as the taper of the facing rib 3 is disposed on the mouth edge of the socket 9, the O-ring 7 can be easily inserted and slipped therein. Furthermore, in this case, since the O-ring groove 6 is carved perpendicularly to the axial direction of the threaded part 2, the proximal side (flange side) of the groove 6 inevitably presents a stepped part 6a. , one side of the O-ring 7 can be received to the maximum, and from this point of view as well, stability against screw insertion is increased.

In this way, the plug 8 attached to the socket 9 can be strongly tightened without causing distortion to the O-ring 7.
After this (during use), even if the water pressure in the socket 9 rises, the O-ring 7 is present, so the O-ring's original water-stopping effect is exerted. At this time, even if a so-called extrusion phenomenon occurs in the O-ring 7 due to large pressure, the groove 6
Since the stepped portion 6a on the flange side has a ribbed structure, the stepped portion 6a exerts a kind of back-up spring action and prevents protrusion. Therefore, the O-ring 7 is not deformed and can withstand high pressure.
By the way, for the plug with the shape conditions mentioned above, 30
Even when pressurized to Kg/ ^m2 , there was no water leakage or gushing.

<Effects of the invention> As mentioned above, the concrete segment grout hole plug of the present invention has an O-ring in a groove cut into the base of the threaded part of the plug body, so that the socket (grout hole ), the O-ring is stable and has a reliable water-stopping effect that does not cause distortion, and in this case, the groove is in the tapered further part, so the rear part of the groove becomes a stepped part. Since it has a back-up spring action, it does not cause the phenomenon of extrusion even if a large leakage pressure is applied, and from this point of view it can withstand long-term use.
Further, since this O-ring can be stably installed by fitting in a groove, an extremely small-diameter O-ring is sufficient, and assembly and installation are facilitated. Furthermore, since this O-ring is arranged in the rear part, it has practical effects such as easy tightening work.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention; Fig. 1 is a perspective view, Fig. 2 is a cross-sectional view, Fig. 3 is an explanatory view of the state of use, and Fig. 4 is a partially vertical side view of a conventional product. . 1...Plug body, 2...Threaded part, 3...
Counterpart, 4...Flange part, 6...O-ring groove, 7...O-ring.

Claims (1)

[Scope of utility model registration request] In a grout hole plug that has a threaded part and a flange part that are screwed into a grout hole socket buried in the concrete segment body, an inner taper is provided at the base of the threaded part at the rim of the grout hole socket. A segment grout is formed by forming a tapered flat part corresponding to the flat part, an annular groove for an O-ring perpendicular to the axial direction at an intermediate position of the taper of the flat part, and fitting the O-ring into the groove. Hall plug.