JP7170990B2 - concrete detector - Google Patents

Description

TECHNICAL FIELD The present invention relates to a concrete detector, and more particularly to a compact and inexpensive concrete detector.

When filling the arc-shaped space formed between the outer circumference of the tunnel center and the inner wall of the tunnel with lining concrete, it is required to detect the position of the space in which the concrete is filled. Capacitive level switches (for example, Model C-1000 manufactured by SEAL Keisoku Kogyo Co., Ltd.) are used for such applications.

As concrete detectors, those using an optical sensor disclosed in Patent Document 1, those detecting concrete pressure disclosed in Patent Document 2, and the like are known.

JP-A-6-240868 JP-A-3-274421

By the way, the capacitance type level switch conventionally used is large and relatively expensive. On the other hand, in recent years, with the progress of IoT (Internet of Things), it is desired to provide more precise lining concrete filling information. The realization of a concrete detector that has

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to solve such problems and to provide a sufficiently small and inexpensive concrete detector as compared with the conventional one.

In order to achieve the above object, in the first invention, a bar-shaped proximity switch (4) of capacitance type and a detection opening (P1) provided in a frame plate (P) forming a concrete filling space (S) are provided. Inside, fixing means (2 ), and a metal layer (52) is provided so as to cover the peripheral surface of the tip detection portion (41) of the proximity switch (4).

According to the first aspect of the present invention, it is possible to realize a sufficiently small and inexpensive concrete detector with a simple configuration in which the proximity switch is positioned within the detection opening. In particular, by providing the metal layer, the distance between the tip detection portion and the inner peripheral surface of the detection opening can be made sufficiently small, so the detection opening can be made smaller, and the entire concrete detector can be installed more compactly. . Also, by providing the metal layer, reliable detection becomes possible.

In the second aspect of the invention, the metal layer is constituted by the peripheral wall (52) of the metal cap (5) covering the peripheral surface and the end face of the tip detecting portion (41).

According to the second aspect of the present invention, the metal layer can be provided with a simple structure in which a metal cap is attached to the tip detecting portion, and the end face of the tip detecting portion can be protected from wear.

In the third invention, only the central portion (511) of the end surface of the metal cap (5) is exposed to the concrete filling space (S).

According to the third aspect of the present invention, since only the central portion of the end face is exposed to the concrete-filled space, the reaction area is reduced compared to exposing the entire end face. It is less susceptible and can avoid false positives more effectively.

In the fourth aspect of the present invention, the cylindrical shape is mounted in the detection opening (P1) so as to cover the periphery of the tip detection part (41) of the proximity switch (4) and has a thickness that secures the distance (d). further comprises an insulator (3) of

According to the fourth aspect of the invention, the proximity switch can be reliably held by the insulator, and the liquid-tightness of the detection opening can be easily ensured.

In the fifth aspect of the present invention, the fixing means (2) fixes the insulator (3) in such a manner that the posture of the insulator (3) can be visually observed.

According to the fifth aspect of the present invention, it is possible to visually confirm whether the insulator is properly positioned in the detection opening and the liquid tightness is ensured.

The symbols in parentheses above refer to the corresponding relationship with specific means described in the embodiments described later.

As described above, the concrete detector of the present invention can be made sufficiently smaller and less expensive than conventional ones.

FIG. 3 is a front view of a tunnel center frame provided with a concrete detector; 1 is an overall cross-sectional view of a concrete detector according to a first embodiment of the present invention; FIG. It is a cross-sectional view of a detector body. It is an exploded sectional view of a detector main body. FIG. 4 is an overall cross-sectional view of a concrete detector in a second embodiment of the invention; FIG. 11 is a cross-sectional view of a detector body in a third embodiment of the present invention; It is an exploded sectional view of a detector main body.

The embodiments described below are merely examples, and various design improvements made by those skilled in the art are also included in the scope of the present invention without departing from the gist of the present invention.

(First embodiment)
FIG. 1 shows a tunnel center M provided with a concrete detector Dt of the invention. That is, the arc-shaped tunnel center M is positioned inside the tunnel T whose inner wall is arc-shaped, and the lining concrete C is filled between the outer circumference of the tunnel center M and the inner wall of the tunnel T. arc-shaped filling space S is formed. The tunnel center M has a central crown form Fa, a side form Fb rotatably connected to the left and right ends thereof by a known structure, and an inverted form Fb rotatably connected to the lower end of the side form Fb by a known structure. Consists of Form Fc. A plurality of concrete detectors Dt, whose details will be explained below, are installed at predetermined intervals in the outer peripheral direction of the tunnel center M on the outer periphery of each of the forms Fa to Fc (more precisely, the skin plate that constitutes the outer periphery). It is In addition, FIG. 1 shows that the lining concrete C is being filled in the filling space S from the inverted form Fc to the lower part of the side form Fb.

FIG. 2 shows a partially cross-sectional side view of the concrete detector Dt. In FIG. 2, a skin plate P as a frame body is provided with a circular detection opening P1 at a predetermined position. S is formed. Inside the skin plate P, a detector body 1, whose details will be described later, is mounted facing the detection opening P1. A fixing means 2, which will be described later, is provided.

FIG. 3 shows a cross-sectional view of the detector body 1, and FIG. 4 shows its exploded cross-sectional view. The insulator 3 constituting the detector main body 1 is made of an electrically insulating material such as a resin, and has a cylindrical shape with a constant thickness and a stepped tip 31 with a small diameter. The outer diameter of the tip 31 of the insulator 3 is substantially equal to the inner diameter of the detection opening P1, and the length of the tip 31 is equal to the thickness of the skin plate P. As shown in FIG. As a result, the tip 31 of the insulator 3 is liquid-tightly fitted in the detection opening P1 (FIG. 3). Here, the thickness of the tip portion 31 of the insulator 3 is set to a dimension that can secure a distance d between the inner periphery of the detection opening P1 and the proximity switch 4, which will be described later, so that the proximity switch 4 does not malfunction under the influence of the skin plate P. .

A rod-shaped capacitive proximity switch 4 having a slightly smaller diameter tip detecting portion 41 is inserted into the cylinder of the insulator 3 . A metal cap 5 covers the entire end surface and the peripheral surface of the tip detecting portion 41, and the end wall 51 of the cap 5 is flush with the outer opening end surface of the insulator 3 and the outer surface of the skin plate P. (Fig. 3).

The end wall 51 of the cap 5 avoids the wear of the tip detector 41 of the proximity switch 4 due to the scraping of the skin plate P, etc., and the peripheral wall 52 of the cap 5 prevents the tip detector 41 from wearing out. A metal layer is provided to cover the peripheral surface. By providing the metal layer, malfunction due to the influence of the skin plate P is eliminated even if the distance d between the detection opening P1 and the inner periphery of the detection opening P1 is made smaller than when there is no metal layer. As a result, the detection aperture P1 can be made smaller, and the size of the detector main body 1 can be reduced. Further, when the metal layer is provided, the proximity switch 4 functions like a touch sensor and does not operate until the tip detecting portion 41 is brought into contact with a material having a different dielectric constant, that is, lining concrete. This allows reliable detection.

The opening end face of the cap 5 is in contact with the stepped surface 32 formed on the inner periphery of the insulator 3, and the cap 5 is adhesively fixed to the inner periphery of the insulator 3 in this state. A signal line 44 extends from the rear end of the proximity switch 4 . As the proximity switch 4, for example, E2K-X manufactured by Omron Co., Ltd. or the like can be suitably used.

In FIG. 2, the fixing means 2 has a holding plate 21 bent in an L shape, and the tip of the long side thereof is fitted to the intermediate threaded portion 42 of the proximity switch 4 through an opening 211 provided here. The rear end surface of the insulator 3 is pressed via the nut member 11 screwed to the portion 42 . A cylindrical body 22 is formed at the tip of the pressing plate 21, and when the tip of the pressing plate 21 is fitted to the intermediate threaded portion 42 of the proximity switch 4, the intermediate threaded portion 42, the base end portion 43, and further The lead-out end of the signal line 44 from the base end portion 43 is positioned inside the cylindrical body 22 and protected from the outside.

A bolt 23 is inserted through an opening 213 provided at the base end of the long side of the restraining plate 21 , and the bolt 23 is coupled to a weld nut 24 fixed to the back surface of the skin plate P. As shown in FIG. By appropriately screwing the bolt 23 into the weld nut 24, the insulator 3 is pressed against the skin plate P with an appropriate force, thereby fixing the detector main body 1. As shown in FIG. With this fixing means 2, the posture of the insulator 3 can always be visually observed from the outside, so that it can be confirmed that the insulator 3 (and the proximity switch 4) are properly positioned within the detection opening P1. .

According to such a concrete detector, the proximity switch 4 detects when the concrete surface of the lining concrete C filled in the filling space S reaches the cap 5 portion covering the tip detection portion 41 of the proximity switch 4. Then, a detection signal is output. Thereby, the filling position of the lining concrete C can be confirmed.

(Second embodiment)
Another example of the fixing means 2 is shown in FIG. Here, the weld nut 25 constituting the fixing means 2 is concentrically arranged so as to surround the outer side of the insulator 3 of the detector body 1 and is fixed to the back surface of the skin plate P. As shown in FIG. A cylindrical holding member 6 is screwed into the weld nut 25 so as to cover the detector main body 1 . The rear end surface of the insulator 3 is pressed through the nut member 11 screwed into the detector body 1, and the insulator 3 is pressed against the skin plate P with an appropriate force, thereby fixing the detector body 1. As shown in FIG.

(Third embodiment)
In the present embodiment shown in FIGS. 6 and 7, the shape of the cap 5 constituting the detector body 1 is different from that of the first embodiment. are also different. Other structures are the same as those of the first embodiment, and the same parts are denoted by the same reference numerals. The following description will focus on differences from the first embodiment.

6 and 7, the metal cap 5 that covers the tip detecting portion 41 of the proximity switch 4 has a small-diameter projecting portion 511 formed in the central portion of the end wall 51 thereof. In this embodiment, the projecting portion 511 has a cylindrical shape. An opening 311 is formed at the center of the tip portion 31 of the insulator 3 that receives the tip detection portion 41 covered with the cap 5, so that the projecting portion 511 of the cap 5 can be inserted. there is In the inserted state, the tip surface of the projecting portion 511 is flush with the end surface of the insulator tip portion 31 (FIG. 6).

According to such a structure, only the central portion of the end surface of the cap 5 is exposed to the filling space S by the projecting portion 511. Therefore, when the concrete detector Dt is provided on the top form Fa (FIG. 1), for example, Even if water droplets fall from the inner wall of the upper tunnel T, the effect of the water droplets can be minimized to effectively prevent malfunction due to adhesion of water droplets. In addition, in this structure, the whole can be fixed simply by inserting the cap 5 into the insulator 3, further inserting the tip detecting portion 41 of the proximity switch 4 into the cap 5, and pressing it against the skin plate P. Therefore, installation and processing are easy. This can be achieved at a lower cost than the structure of the first embodiment. In short, since it is sufficient to expose only a part of the end surface of the tip detecting portion 41 of the proximity switch 4 to the filling space S, the structure in which the protruding portion 511 is formed at the center portion of the end wall of the cap 5 only realizes this. This is only an example of when to do so.

(Other embodiments)
Instead of attaching the metal cap 5 to the tip detection part 41 of the proximity switch 4, a metal foil is wound around the peripheral surface of the tip detection part 41 to form a metal layer, and the end face of the tip detection part 41 is wear-resistant. It is good also as a structure which sticks the resin board etc. which have. Further, if the wear resistance is not a problem, the end face of the leading end detecting portion 41 may be exposed to the filling space S as it is. Also, the insulator 3 is not necessarily required, and may be an air layer. In addition, although the case where the concrete detector is provided in the tunnel center has been described in the above embodiment, the application of the present invention is not limited to this.

DESCRIPTION OF SYMBOLS 1... Detector body, 2... Fixing means, 3... Insulator, 4... Proximity switch, 41... Tip detector, 5... Cap, 51... End wall, 511... Protruding part (center part), 52... Peripheral wall of cap (metal layer), 6: holding member, P: skin plate (frame plate), P1: detection opening, S: space filled with concrete.

Claims (5)

A rod-shaped proximity switch of capacitance type and a detection opening provided in a frame plate forming a concrete-filled space are provided with the proximity switch in a state in which the tip detection portion is spaced from the inner peripheral surface of the detection opening. fixing means for fixing to a frame plate, and a metal layer is provided so as to cover the peripheral surface of the tip detecting portion of the proximity switch. 2. The concrete detector according to claim 1, wherein the metal layer is composed of a peripheral wall of a metal cap that covers the peripheral surface and the end face of the tip detecting portion. 3. The concrete detector according to claim 2, wherein only the central portion of the end face of the metal cap is exposed to the concrete-filled space. 4. The concrete according to any one of claims 1 to 3, further comprising a cylindrical insulator mounted in said detection opening so as to cover the periphery of the tip detection portion of said proximity switch and having a thickness for ensuring said interval. Detector. 5. The concrete detector according to any one of claims 1 to 4, wherein the fixing means fixes the proximity switch in a state where the posture of the proximity switch can be visually observed.

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