JP2012208020A - Steel material selection sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a steel material selection sensor with a coil of which the attachment workability to a reinforced concrete pole and the durability are improved.SOLUTION: A steel material selection sensor 2 includes: a coil 21 wound around like a rectangle; and a holder 22 which is planarly provided to store the coil 21 so that its plate thickness direction and an axis direction of the coil 21 become parallel with each other. In the coil 21 and the holder 22, the long side direction of the coil 21 is provided by being bent along the outer peripheral surface of the reinforced concrete pole 1. Thus, the inner peripheral surface of the holder 22 is brought into contact with the outer peripheral surface of the reinforced concrete pole 1 to be attached to the reinforced concrete pole 1.

Description

  The present invention relates to a steel material selection sensor, and more particularly to a steel material selection sensor for selecting the type of steel material used for a reinforced concrete column.

  The said reinforced concrete pillar is a concrete pillar which has arranged the reinforcing bar 12 inside the concrete 11, as shown in FIG.12 (C). The reinforcing bar 12 is composed of a tension steel material (TW: tension wire) and a non-tensile steel material (NTW: non-tension wire). And as a PC steel material (prestressed concrete tension steel material) used as a tension steel material, either one of two types of steel materials, a strengthened PC steel wire for wire drawing and a heat treated strengthened PC steel rod, is used. Since PC steel wire and PC steel bar have different aging degradation levels, it is necessary to select whether PC steel wire or PC steel bar is used as the tension steel (TW) of reinforced concrete column 1 is there.

  However, the tension steel (TW) is arranged inside the concrete. For this reason, there is no difference in appearance between the reinforced concrete column 1 using a PC steel wire and the reinforced concrete column 1 using a PC steel bar, and there is a problem that it is difficult to select a tension steel material.

  Therefore, a coil is wound around the reinforced concrete column 1, the difference in permeability between the PC steel wire and the PC steel rod is regarded as a change in the inductance of the coil (see FIG. 13), an alternating current is passed through the coil, and the inductance is measured. There has been proposed a steel material sorting device that compares the measured inductance with a reference value and sorts PC steel wires and PC steel bars in a non-destructive manner (Patent Document 1).

  In the steel material sorting apparatus, the steel material in the reinforced concrete column 1 is regarded as one bar, and a circular coil is wound around the reinforced concrete column 1 to measure the inductance. The circular coil is formed by winding a conducting wire in a spiral shape, and a collective coil 4 shown in FIG. 12 (A) and a split coil 5 shown in FIG. 12 (B) have been proposed. The collective coil 4 can be used only for the top portion of the reinforced concrete column 1 because there is no connection portion in the winding direction.

  As shown in FIG. 12C, the split coil 5 is provided with a connecting portion 51 in the winding direction for inserting the reinforced concrete column 1 into the split coil 5, and the reinforced concrete column 1 is inserted into the split coil 5. After that, the connectors C attached on both sides of the connecting portion 51 are connected and wound around the reinforced concrete column 1 for use. By providing the connection part 51, it can wind easily besides the top part of the reinforced concrete pillar 1. FIG.

  However, the split coil 5 needs to perform a series of operations of opening the connection portion 51, winding it around the reinforced concrete column 1, and connecting the connectors C attached to both ends of the connection portion 51, and the workability is poor. There was a problem. Moreover, when the split coil 5 opens the connecting portion 51 and inserts it into the reinforced concrete column 1, there is a risk of foreign matter adhering or pinching to the connector C by moving the connecting portion 51 close to the reinforced concrete column 1. There is a high possibility that the connector C will be damaged. Further, since the attachment and detachment is repeated many times, there is a problem that the wear of the connector C occurs and the life is short.

JP 2010-91303 A

  Then, this invention makes it a subject to provide the steel-material selection sensor provided with the coil which aimed at the workability | operativity and durability improvement to a reinforced concrete pillar.

  The invention according to claim 1 for solving the above-described problem is a steel material selection sensor for selecting the type of steel material used for a reinforced concrete column, and a coil wound in an elliptical shape or a rectangular shape, A holder for receiving the coil so that the plate thickness direction and the axial direction of the coil are parallel to each other, and the coil and the holder have the long side direction of the coil in the reinforced concrete. It exists in the steel-material selection sensor characterized by being curved along the outer peripheral surface of a pillar.

  The invention according to claim 2 resides in the steel material sorting sensor according to claim 1, wherein the short side of the coil is provided at 50 mm or more.

  A third aspect of the present invention resides in the steel material sorting sensor according to the first or second aspect, wherein the distance between the inner peripheral surface of the holder and the coil is 10 mm or less.

  According to a fourth aspect of the present invention, the steel material sorting according to any one of the first to third aspects, wherein the long side of the coil is provided at a quarter or more of the circumference of the reinforced concrete column. It exists in the sensor.

  As described above, according to the first aspect of the present invention, the coil is held inside, and the inner peripheral surface of the curved holder can be attached to the reinforced concrete column simply by touching the outer peripheral surface to the reinforced concrete column. It is possible to improve the workability and durability of mounting on the pillar.

  According to the second aspect of the present invention, when the short side of the coil is provided at 50 mm or more, the one side part and the other side part of the short side direction of the coil cancel each other out and the inductance becomes small. And a sufficient inductance difference for discriminating between the PC steel bar and the PC steel wire can be obtained.

  According to invention of Claim 3, since the distance of the inner peripheral surface of a holder and a coil is provided in 10 mm or less, obtaining sufficient inductance difference for discriminating a PC steel rod and a PC steel wire Can do.

  According to invention of Claim 4, since the long side of a coil is provided in 1/4 or more of the circumference of a reinforced concrete pillar, since steel materials in more reinforced concrete pillars can be measured, PC steel rod and A sufficient inductance difference for discriminating the PC steel wire can be obtained.

It is a perspective view which shows the state which attached the steel material selection sensor of this invention to the reinforced concrete pillar. (A)-(C) is a perspective view, a top view, and a side view of the steel material sorting sensor shown in FIG. 1, respectively. (A)-(C) are the perspective view of the coil accommodated in the holder shown in FIG. 1, a top view, and a side view. (A) is the sectional view on the AA line of FIG. 2 (B), (B) is the sectional view on the BB line of FIG. 2 (A). FIG. 2 is a block diagram showing a steel material sorting apparatus using the steel material sorting sensor shown in FIG. 1. It is a graph which shows the inductance of a coil when attaching the steel sort sensor shown in Drawing 1-Drawing 4 to multiple types of reinforced concrete pillars using PC steel rod, and multiple types of concrete pillars using PC steel wire. . It is a graph which shows the result of having measured the inductance of the coil about several types of steel material selection sensors from which the length of the short side of a coil differs in the range of 40 mm-150 mm. It is a graph which shows the result of having measured the inductance of the coil when the steel-material selection sensor from which the distance of the inner peripheral surface of a holder and a coil differs in the range of 0 mm-25 mm was each attached to the reinforced concrete pillar. Multiple types of steel selection sensors with different coil lengths in the range of 1/8 to 3/4 of the outer circumference of reinforced concrete columns are attached to reinforced concrete columns using PC steel and reinforced concrete columns using PC steel bars, respectively. It is a graph which shows the result of having measured the inductance difference of the coil 21 at the time. It is a top view of the steel material selection sensor in other embodiments. It is a top view of the coil in other embodiments. It is the schematic which shows an example of the coil used for the conventional steel materials sorter. It is a graph which shows the inductance of the coil when the conventional coil shown in FIG. 12 is attached to a plurality of types of reinforced concrete columns using PC steel bars and a plurality of types of concrete columns using PC steel wires.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. First, before describing the steel material selection sensor of the present invention, the structure of a reinforced concrete column will be described with reference to FIG. FIG. 1 is a perspective view showing a state in which a steel material sorting sensor of the present invention is attached to a reinforced concrete column. In addition, in FIG. 1, the reinforced concrete pillar is partially sectional drawing.

  As shown in FIG. 1, the reinforced concrete column 1 is composed of concrete 11 and a plurality of reinforcing bars 12 arranged inside the concrete 11. The concrete 11 is provided in a columnar shape. The plurality of reinforcing bars 12 are provided in a bar shape, and are arranged on a circle along the outer peripheral surface of the concrete 11 so that the longitudinal direction thereof is along the axial direction of the concrete 11.

  A part of the plurality of reinforcing bars 12 is made of a tension steel material (TW: tension wire), and the rest is made of a non-tension steel material (NTW: non-tension wire). And as PC steel materials used as tension steel materials, as explained also in the background art, one of two types of steel materials, PC steel wire and PC steel rod, is used. The steel material selection sensor 2 of the present invention is a sensor for identifying whether a PC steel wire or a PC steel bar is used as the PC steel material of the reinforced concrete column 1 described above. That is, when the steel material sorting sensor 2 is brought close to the reinforced concrete column 1 using the PC steel rod and when the steel material sorting sensor 2 is brought close to the reinforced concrete column 1 using the PC steel wire, the steel material sorting sensor 2 described later is used. The impedance of the inner coil 21 is different. The type of PC steel can be selected based on this impedance difference.

  Next, in addition to FIG. 1 mentioned above, the structure of the steel material selection sensor 2 of this invention is demonstrated with reference to FIGS. 2A to 2C are a perspective view, a top view, and a side view, respectively, of the steel material sorting sensor shown in FIG. 3 (A) to 3 (C) are a perspective view, a top view, and a side view of the coil housed in the holder shown in FIG. 4A is a cross-sectional view taken along line AA in FIG. 2B, and FIG. 4B is a cross-sectional view taken along line BB in FIG.

  The steel material sorting sensor 2 includes a coil 21 and a holder 22 that houses the coil 21. As shown in FIG. 3, the coil 21 is provided by winding a conductive wire in a spiral shape so as to be rectangular when viewed from the axial direction. The short side L1 of this coil 21 is provided at 50 mm or more. Further, the long side L2 of the coil 21 is provided at ¼ or more of the circumference of the reinforced concrete column 1.

  As shown in FIG. 2 and the like, the holder 22 is provided in a flat plate shape, and accommodates the coil 21 so that the plate thickness direction and the axial direction of the coil 21 are parallel to each other. The holder 22 is made of resin for concentrating the influence of the magnetic field of the coil 21 only on the reinforcing bar 12 of the reinforced concrete column 1, and using a highly rigid plastic (for example, ABS or hard polyvinyl chloride) to prevent the deflection. Yes.

  The coil 21 and the holder 22 are provided such that the long side direction of the coil 21 is curved along the outer peripheral surface of the reinforced concrete column 1. 4A, the distance L3 between the inner peripheral surface of the holder 22 and the coil 21 is set to 10 mm or less. Thus, as shown in FIG. 1, when the steel material selection sensor 2 is attached to the reinforced concrete column 1 by placing the inner peripheral surface of the holder 22 against the outer peripheral surface of the reinforced concrete column 1, the outer peripheral surface of the reinforced concrete column 1 and the coil 21. The distance can be 10 mm or less.

  Next, a steel material sorting device 3 using the above-described steel material sorting sensor 2 will be described with reference to FIG. As shown in the figure, the steel material sorting apparatus 3 includes an oscillator 31, a signal synthesis / separation unit 32, a signal amplification unit 33, a microcomputer 34, a memory 35, and a display unit 36. The oscillator 31 generates an alternating current that oscillates at, for example, 100 Hz or 120 Hz and is supplied to the coil 21. The signal synthesis / separation unit 32 supplies the alternating current from the oscillator 31 to the coil 21 and outputs the voltage across the coil 21 and the coil energization current to the signal amplification unit 33. The signal amplifying unit 33 amplifies the terminal voltage of the coil 21 and the coil energization current output from the signal synthesis / separation unit 32 and outputs the amplified voltage to the microcomputer 34. The microcomputer 34 obtains the inductance of the coil 21 from the terminal voltage of the coil 21 and the coil energization current supplied from the signal amplification unit 33. The microcomputer 34 compares the obtained inductance with a reference value (stored in the memory 35), selects whether it is PC steel or PC steel wire, and outputs the result to the display unit 36. To do.

  Next, the present inventors have installed a steel material sorting sensor 2 as shown in FIG. 1 to a plurality of types of reinforced concrete columns 1 using PC steel bars, and a plurality of types of reinforced concrete columns using PC steel wires. In the case where the steel material sorting sensor 2 is attached to each 1 as shown in FIG. 1, the inductance of the coil 21 was measured to measure the effect of the present invention. The results are shown in FIG. As shown in the figure, since there is a difference in the inductance of the coil 21 between the PC steel and the PC steel wire, if the inductance of the coil 21 is measured as in the conventional case shown in FIG. It was found that can be sorted.

  Therefore, since the coil 21 is held inside and the inner peripheral surface of the curved holder 22 can be attached to the reinforced concrete column 1 simply by touching the outer peripheral surface of the reinforced concrete column 1, the workability and durability of the attachment to the reinforced concrete column 1 can be achieved. It is possible to improve the performance.

  Next, the inventors measured the inductance of the coil 21 for different steel material sorting sensors 2 in the range of the short side L1 of the coil 21 in the range of 40 mm to 150 mm, and confirmed the effect of the present invention. The results are shown in FIG. As shown in the figure, when the length of the short side L1 of the coil 21 is less than 50 mm, the inductance decreases rapidly, and when the length is 50 mm or more, the inductance increases rapidly, which is 2.5 times that of the length 40 mm. It was found that the above inductance value can be obtained. That is, by providing the short side L1 of the coil 21 at 50 mm or more, it is possible to prevent the inductance from being reduced by canceling out the magnetic field between the one side portion and the other side portion of the coil 21 in the short side direction. It was found that a sufficient inductance difference for discriminating between the bar and the PC steel wire can be obtained.

  Furthermore, the present inventors set different steel material sorting sensors 2 in the range of the distance L3 (= distance between the reinforced concrete column 1 and the coil 21) between the inner peripheral surface of the holder 22 and the coil 21 in the range of 0 mm to 25 mm, respectively. The effect of the present invention was confirmed by measuring the inductance of the coil 21 when attached to the coil. The results are shown in FIG. As shown in the figure, when the distance L3 is 10 mm or more, the difference in inductance due to the difference between the PC steel material and the PC steel rod decreases rapidly, and when the distance is less than 10 mm, the difference between the PC steel material and the PC steel rod. It was found that the inductance difference due to can be increased. Therefore, it was found that by providing the holder 22 so that the distance L3 is 10 mm or less, a sufficient inductance difference for discriminating between the PC steel bar and the PC steel wire can be obtained.

  Furthermore, the present inventors have used a plurality of types of steel material selection sensors 2 in which the length of the long side L2 of the coil 21 is different in the range of 1/8 to 3/4 of the outer periphery of the reinforced concrete column 1 as a reinforced concrete column 1 using PC steel. The effect of the present invention was confirmed by measuring the inductance difference of the coil 21 when it was attached to each of the reinforced concrete pillars 1 and PC steel bars. The results are shown in FIG. As shown in the figure, when the long side L2 of the coil 21 is less than ¼ of the circumference of one reinforced concrete column, the difference in inductance due to the difference between the PC steel material and the PC steel rod cannot be obtained. In the case of 1/4 or more of one circumference, an inductance difference due to the difference between the PC steel material and the PC steel bar can be obtained.

  In the above-described embodiment, the length of the long side L2 of the coil 21 is set to ¼ that of the reinforced concrete column 1, but the present invention is not limited to this. As shown in FIG. 10 (A), the holder 22 may be formed in a C shape so as to be ½ of the circumference of one reinforced concrete column. Moreover, it is not necessary to curve all the long side directions of the holder 22, and as shown in FIG.

  In the embodiment described above, the coil 21 is formed in a rectangular shape when viewed from the axial direction, but the present invention is not limited to this. As shown in FIG. 11, it may be formed in an elliptical shape. Similarly in this case, it is desirable that the short side L1 is 50 mm or more and the long side L2 is provided at 1/4 or more of the circumference of one reinforced concrete column.

  Further, the above-described embodiments are merely representative forms of the present invention, and the present invention is not limited to the embodiments. That is, various modifications can be made without departing from the scope of the present invention.

1 Reinforced concrete pillar 2 Steel material selection sensor 12 Reinforcing bar 21 Coil 22 Holder L1 Short side L2 Long side

Claims (4)

A steel material sorting sensor for sorting the types of steel materials used in reinforced concrete columns,
A coil wound in an elliptical or rectangular shape;
Provided with a flat plate shape, and a holder for accommodating the coil so that the plate thickness direction and the axial direction of the coil are parallel,
The steel material selection sensor, wherein the coil and the holder are provided such that a long side direction of the coil is curved along an outer peripheral surface of the reinforced concrete column. The steel material selection sensor according to claim 1, wherein a short side of the coil is provided at 50 mm or more. The steel material selection sensor according to claim 1 or 2, wherein a distance between the inner peripheral surface of the holder and the coil is 10 mm or less. The steel material selection sensor according to any one of claims 1 to 3, wherein a long side of the coil is provided at a quarter or more of a circumference of the reinforced concrete column.

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