JP2003023318A - Array antenna for inspecting concrete structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an array antenna, with which antenna elements for high frequency radar can be easily relocated along with curved surfaces for inspecting the inside of a concrete structure having a large number of curved surfaces on a surface form like a tunnel, etc. SOLUTION: An array antenna 10 for inspecting a state inside the concrete structure (not shown in Figure) as an inspection object from the reflected waves of radiated high frequency radio waves by laterally locating a plurality of antenna elements 2 for high frequency along with the surface of the body structure is formed from a unit antenna 1 for connecting a feeder line 4 (coaxial cable 7) for transmitting a transmitting/receiving signal to each of antenna elements 2 and a connecting member 8, and a prescribed number of unit antenna 3 are freely attachably and detachably fitted and fixed on an array antenna fitting stand (not shown in Figure) by the connecting member 8.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an array antenna for inspecting a concrete structure.

[0002]

2. Description of the Related Art In concrete structures such as tunnels and highways that are subject to harsh conditions, it is necessary to inspect the scratches inside the structures to maintain safety. Most of the measurements were by radio waves using a single element antenna.

[0003]

While the inspection with the single element antenna is a one-dimensional inspection in fact, a method for two-dimensional inspection using a high frequency radar of several gigahertz has been developed. It is being appreciated. The antenna used in this case is a two-dimensional inspection of the structure surface by arranging the array antenna in which the antenna elements are arranged side by side close to the surface of the structure to be inspected and moving the array antenna in the horizontal direction. Therefore, the inspection efficiency can be improved.

By the way, as described above, in the case of a high-frequency radar array antenna, it is necessary to arrange each antenna element close to the surface of the structure. Therefore, in the case of a structure whose surface is mainly a curved surface such as a tunnel. , While an array antenna with a single antenna element attached according to the shape of the tunnel is required, the curved surface of the tunnel is composed of curved surfaces with various curvatures, so it is often necessary to support many tunnels. It is necessary to prepare the array antenna of. Therefore, it is necessary to prepare a large number of expensive antenna elements, and there is a problem that the inspection cost rises.

The present invention has been made in view of the above problems, and high-frequency antenna elements for inspecting the inside of a concrete structure having many curved surfaces such as tunnels can be easily rearranged along the curved surfaces. It is an object of the present invention to provide an array antenna adapted to the above.

[0006]

In order to achieve the above object, the concrete structure inspection array antenna of the present invention has a plurality of high-frequency antenna elements arranged side by side along the surface shape of the concrete structure to be inspected. An array antenna for receiving a reflected wave of a radiated high frequency radio wave to inspect the inside of the structure, wherein the array antenna includes an antenna element, a unit antenna having the antenna element attached, a connecting member and an array antenna mount. The connecting member is configured such that a plurality of the unit antennas are detachably mounted side by side and along the surface of the structure, and are fixed to the array antenna mount.

There is no particular limitation on the means for arranging the unit antennas side by side along the surface shape of the concrete structure to be inspected and attaching it to the connecting member. For example, when the unit antennas are screwed to the connecting member, the antenna elements can be arranged along the surface of the structure to be inspected. Therefore, it is possible to form the edge shape of the connecting member facing the surface of the concrete structure so as to have a curvature along the surface shape, and fix the unit antenna along the edge. The mounting member can usually be made by processing a metal plate, but the present invention is not limited to this. However, it is preferably a conductor.

In the present invention, there is no particular critical value for the curvature, and the curvature is zero, that is, includes a straight line.

Means for removably attaching the unit antenna to the connecting member is not particularly limited. For example, mounting means may be used in which screw holes having common specifications are provided at predetermined positions of the connecting member and the unit antenna, and screwed.

The present invention prepares a number of connecting members which are suitable for each curved surface (including straight line) of a concrete structure such as a tunnel to be inspected in advance, thereby maintaining a high measurement accuracy and reducing the number of connecting members. By preparing a unit antenna, it is possible to inspect many concrete structures to be inspected.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below with reference to an embodiment with reference to the accompanying drawings.

Antenna element 2 used in this embodiment
Is composed of a pair of conductors (triangles in the present embodiment) having the same shape as shown in FIG. 1, and is attached to a predetermined position of the casing 3 for use.

The feed line 4 attached to each piece of the antenna element 2 is drawn into the casing 3 through an opening 5 formed in the casing 3, and a matching circuit 6 is used to feed a transmitter / receiver (not shown). It is connected to a coaxial cable 7 which is connected to a sending / receiving terminal (not shown).

The matching circuit 6 is a circuit which has been conventionally used normally for converting the transmission mode from unbalanced (line in the coaxial cable) to balanced (antenna). The means for connecting the antenna element 2 and the coaxial cable 7 including the matching circuit 6 are:
Since those commonly used in this type of technology can be used as appropriate, detailed description will be omitted.

The casing 3 is for fixing the antenna element 2 to the connecting member 8 (FIGS. 2 to 5) described below, and the shape of the casing 3 used in the present embodiment is the antenna element 2. The side to attach is about 57
A square column having a height of about 78 mm was used as a square column of mm. However, this shape and size are examples, and the present invention is not limited to this, and can be appropriately modified according to the use situation. Reference numeral 9 shown in FIG. 1 is a screw hole for screwing the casing 3 to the connecting member 8.

The connecting member 8 used in the array antenna 10 of the first embodiment shown in FIGS. 2 to 4 is applied to an inspection of a concrete structure (not shown) having a curvature of zero, that is, a flat surface. .

The connecting member 8 of the first embodiment is manufactured by processing a metal plate, and as shown in FIG. 3, a transmitting connecting member 8a to which the unit antennas 1 having the same specifications are attached. (FIG. 3a) and the receiving connecting member 8b (FIG. 3a).
b) (These are collectively referred to as the connecting member 8 when collectively referred to)
And a screw 11 on each connecting member 8a, 8b.
(FIG. 5), the unit antennas 1 are attached (16 in the first embodiment), and the transmitting connecting member 8a and the receiving connecting member 8 are attached.
The array antenna mounting base (not shown) was mounted by the overhanging portion 8c of the mounting member 8 so that the unit antennas 1 and b were arranged alternately (FIG. 2).

The method of using the array antenna 10 is such that the antenna element 2 side can be moved directly toward the array antenna mount (or 5 mm) so that the antenna element 2 side can be moved toward the surface of the concrete structure to be inspected at a constant interval (for example, 5 mm). A car (not shown) is attached, the array antenna is moved in a direction intersecting the longitudinal direction while pressing it, and the emission of radio waves and the reception of reflected waves are repeated, and the state inside the concrete structure (cracking) , Junker, defect, peeling,
The mortar is lifted up) and its image is displayed on the display. For these operations, conventionally used means can be applied.

In FIG. 5, the radius is 4791 mm (curvature: 0.0
2087 m ⁻¹ ). The connecting member 8a for transmitting (FIG. 5a) and the connecting member 8b for receiving (FIG. 5b) for the array antenna (not shown) of the second embodiment, which is used for inspection of a tunnel having a curved surface. ). In the connecting member 8 of the second embodiment, the edge portion 12 facing the inspection symmetry plane is formed so that the arrangement surface of the antenna element (not shown) draws an arc, and the number of attachable antenna elements is 16 The outside is the first
Since it is similar to the embodiment, the same members are denoted by the same reference numerals and the description thereof is omitted.

As described above, in the array antenna 10 of the first and second embodiments, if a required number of common antenna elements are manufactured, the curvature suitable for the surface shape of the concrete structure to be measured can be obtained. Since the inspection can be performed by preparing the connecting member included therein, the inspection cost can be significantly reduced.

[0021]

As described above, the concrete structure inspection array antenna of the present invention has a shape that matches the surface shape of the inspection object so that the antenna element can be arranged along the surface shape of the inspection object. Since the elements are detachably formed, the total number of expensive antenna elements can be reduced as much as possible, and the inspection cost can be significantly reduced while maintaining high inspection accuracy.

[Brief description of drawings]

FIG. 1 is a perspective view for explaining an outline of a unit antenna used in an embodiment of the present invention.

FIG. 2 is a perspective view showing a partially omitted array according to the first embodiment of the present invention.

FIG. 3 is a view taken along the line III-III of FIG.

4a is a side view taken along the line IVa-IVa of FIG. 3, and FIG. 4a is a side view taken along the line IVb-IVb of FIG.

5 is a side view of a connecting member according to a second embodiment of the present invention, FIG. 5a is a transmission side connecting plate, and FIG. 5b is a receiving side connecting plate as viewed from the same direction as FIG. It is a figure.

[Explanation of symbols]

1 unit antenna 2 antenna elements 7 Coaxial cable (feed line) 8 connecting members 10 array antenna

Continued front page    (72) Inventor Asaaki Kageyama             2-2-2 Yoyogi, Shibuya-ku, Tokyo Tohnichi             Inside the passenger railway (72) Inventor Yasunari Mori             Mitsui Shipbuilding, 3-1-1 Tamama, Tamano City, Okayama Prefecture             Tamano Works Co., Ltd. (72) Inventor Takayoshi Yumi             Mitsui Shipbuilding, 3-1-1 Tamama, Tamano City, Okayama Prefecture             Tamano Works Co., Ltd. (72) Inventor Taichi Mizojiri             Mitsui Shipbuilding, 3-1-1 Tamama, Tamano City, Okayama Prefecture             Tamano Works Co., Ltd. (72) Inventor Kyoji Doi             Mitsui Shipbuilding, 3-1-1 Tamama, Tamano City, Okayama Prefecture             Tamano Works Co., Ltd. (72) Inventor Noriaki Kimura             Mitsui Shipbuilding, 3-1-1 Tamama, Tamano City, Okayama Prefecture             Tamano Works Co., Ltd. F-term (reference) 5J021 AA05 AA08 FA32 HA04 JA10                 5J047 AA09 AA12 EF01                 5J070 AC01 AC02 AD08 AE11

Claims (2)

[Claims] 1. An array antenna in which a plurality of high-frequency antenna elements are arranged side by side along a surface shape of a concrete structure to be inspected, and a reflected wave of a radiated high-frequency radio wave is received to inspect the inside of the structure. The array antenna comprises an antenna element, a unit antenna to which the antenna element is attached, a connecting member, and an array antenna mount. The connecting member has a plurality of the unit antennas removably side by side and the structure surface. An array antenna for inspecting a concrete structure, which is attached along a line and is fixed to the array antenna mount. 2. The array antenna for concrete structure inspection according to claim 1, wherein an edge shape of the connecting member on the side facing the concrete structure surface is formed to have a curvature along the surface shape.