JP4155468B2 - Reinforcing bar search method and reinforcing bar search device for concrete structure, and concrete structure drilling method and drilling tool - Google Patents

Description

  The present invention relates to a reinforcing bar searching method and a reinforcing bar searching device for searching for reinforcing bars arranged in a concrete structure, and a drilling method and a drilling tool for a concrete structure.

  When drilling holes for piping such as air conditioners in the wall of a house, or when drilling holes in buildings and bridge piers, the location of the reinforcing bars placed inside these concrete structures is not known. A major problem is that the reinforcing bars are cut by mistake. Since cutting the reinforcing bars causes a decrease in the strength of the entire structure, it is important to accurately grasp the position of the reinforcing bars when drilling into a concrete structure.

  Therefore, in order to search for the position of the reinforcing bar, a method of inspecting the position of the internal reinforcing bar from the surface of the concrete structure in a nondestructive manner using an electromagnetic induction device or an electromagnetic wave radar device is widely used.

  For example, in Patent Document 1, a reinforcing bar in an existing structure is magnetized by using a direct current or an alternating magnetic field so that a magnetic flux is generated from the reinforcing bar, and the magnetic flux output from the reinforcing bar is detected by a magnetic sensing coil type reinforcing bar probe. Describes how to detect deep reinforcing bars.

JP-A-5-157851

  However, in a conventional search method using an electromagnetic induction device or an electromagnetic wave radar device, the measurable area of the device is limited, and it is possible to search only to a depth of about 20 cm from the surface of the concrete structure. Therefore, the position of the reinforcing bar in the deep part of the concrete structure cannot be grasped, and the reinforcing bar may be cut by mistake.

  Moreover, in patent document 1, not only magnetizing a reinforcing bar but flowing an alternating current and carrying out alternating current magnetization, using a multiple resonance circuit, or using a magnetic flux gun from which magnetic flux is radiated | emitted strongly only to a measurement direction. Although it is described that it is possible to search from the surface of the concrete structure to a depth of about 50 to 60 cm, in this case, it is assumed that the apparatus is complicated and the manufacturing cost of the apparatus becomes high.

  Therefore, in view of the above problems, the present invention provides a reinforcing bar search method and a reinforcing bar search apparatus for a concrete structure that can search for a reinforcing bar arrangement position inside concrete with a simple structure, and is accurate within a range where there is no reinforcing bar. An object of the present invention is to provide a drilling method and drilling tool for a concrete structure that can be drilled in a single hole.

  The method for searching for reinforcing bars in a concrete structure according to the present invention is a method for searching for reinforcing bars arranged in a concrete structure, wherein a preliminary hole is made in the concrete structure with a concrete drill, and a tip portion is provided in the preliminary hole. The method includes inserting a detection rod having a metal detection sensor into the metal and checking the presence or absence of a reaction of the metal detection sensor.

  The worker first searches for a reinforcing bar arranged at a position closest to the surface from the surface of the concrete structure by scanning a detection rod provided with a metal detection sensor on the surface of the concrete structure. Then, a preliminary hole is drilled with a concrete drill at a position where there is no reaction of the metal detection sensor, that is, the reinforcing bar is not arranged. This concrete drill cannot cut a reinforcing bar in normal use, and can drill a concrete structure by drilling manually or using small power. Therefore, when drilling a spare hole, even if it hits an internal reinforcing bar that could not be explored by the above search, the operator can notice at that time, so cut the reinforcing bar by mistake. There is no. If you hit the rebar in the middle of drilling, pull out the concrete drill once and drill at another position.

  After the preliminary hole is drilled as described above, the detection rod is inserted into the preliminary hole. Since the metal detection sensor is provided at the tip of the detection rod, if a reinforcing bar is arranged around the spare hole, the metal detection sensor is detected at the moment when the tip of the detection rod passes around the reinforcement. Reacts to reinforcing bars. This allows the operator not only to reinforce the reinforcing holes around the preliminary holes, but also how far the reinforcing bars are arranged in the radial direction from the preliminary holes depending on the degree of reaction, and the concrete structure. It is possible to simultaneously recognize how deep the reinforcing bars are arranged from the surface of the object.

  In addition, a coil sensor using an electromagnetic induction method can be used as the metal detection sensor.

  By using a coil-type sensor using an electromagnetic induction method as the metal detection sensor, when the detection rod passes through the preliminary hole, a sudden change in the magnetic field occurs around the metal detection sensor. Here, when the reinforcing bar is arranged within the range in which the magnetic field has changed, the reinforcing bar reacts to the magnetic field of the metal detection sensor, and an induced current flows through the reinforcing bar, thereby generating a magnetic field around the reinforcing bar. Then, since the metal detection sensor detects the generation of the magnetic field, it is possible to detect that a reinforcing bar is arranged around the spare hole. In this way, it is possible to easily detect whether or not a reinforcing bar is arranged in a concrete structure by using a detection rod provided with an electromagnetic induction type metal detection sensor in a non-contact manner.

Also, use a coil type sensor that emits a magnetic field with a non-uniform intensity distribution around the axis of the detection rod, insert it into the spare hole while rotating the detection rod around the axis, or center the axis of the detection rod It is better to put in and out several times by changing the rotation angle with respect to.
In other words, if the magnetic field generated by the coil-type sensor is eccentric from the axial center of the detection rod or has an intensity distribution that protrudes in only one direction from the axial center of the detection rod, the preliminary sensor is rotated while rotating the detection rod. As it is inserted into the hole, the range in which the reinforcing bar can be detected moves sequentially in the rotation direction around the spare hole. Also, if you change the rotation angle of the detection rod with respect to the center of the detection rod and put it in and out several times, the rebar is detected in a certain angle range around the spare hole, and it is divided into multiple times while changing the angle in the rotation direction. Will be done.
Therefore, when the metal detection sensor reacts, it can be specified in which direction the reinforcing bar is arranged from the preliminary hole according to the rotation angle of the detection rod. Thereby, it is possible to detect not only the presence of the reinforcing bar but also in which direction the reinforcing bar is arranged with respect to the preliminary hole.

  The concrete structure reinforcing bar search device of the present invention is provided with a metal detection sensor at the tip, a detection rod inserted into a preliminary hole drilled in the concrete structure, and when the metal detection sensor detects the reinforcement, An informing means for informing is provided.

  According to the reinforcing bar search device of the present invention, when the reinforcing bar is arranged around the preliminary hole when the detecting bar is inserted into the preliminary hole drilled in the concrete structure, the tip of the detecting bar is the reinforcing bar. At the moment of passing around, the metal sensing sensor reacts to the reinforcing bar and is notified by the notification means. Thereby, the operator can recognize by the notification means that reinforcing bars are arranged around the spare hole.

  In addition, if the metal sensor is a coil sensor using the electromagnetic induction method, the rebar search device can be configured in a simple manner, and the rebars arranged in the concrete structure can be detected without contact. can do. Further, if the notification means indicates the intensity of the magnetic field generated from the reinforcing bar sensed by the coil type sensor in a stepwise manner, the extent to which the reinforcing bar is arranged from the spare hole is also included. Can be recognized.

  In addition, if the coil sensor emits a magnetic field with a non-uniform intensity distribution around the axis of the detection rod, not only the presence of the reinforcing bar, but also in which direction the reinforcing bar is arranged with respect to the spare hole In other words, it is possible to provide a reinforcing bar searching device capable of detecting.

  The method for drilling a concrete structure according to the present invention is a method for drilling a hole in a position where there is no reinforcing bar in the concrete structure. The first drilling step of drilling a preliminary hole in the concrete structure with a concrete drill, and the preliminary hole , A reinforcing bar search step for inserting a detection rod provided with a metal detection sensor at the tip and checking the presence or absence of a reaction of the metal detection sensor, and if there is no reaction of the metal detection sensor, a spare hole along the spare hole When a hole having a larger diameter is drilled and there is a reaction of the metal detection sensor, the first drilling step and the reinforcing bar searching step are further performed.

  According to the present invention, by performing the first drilling step and the reinforcing bar searching step, it is confirmed that there is no reinforcing bar around the preliminary hole drilled from the surface of the concrete structure toward the deep part, and the air conditioner or the like. Holes for piping and holes necessary for reinforcement work for buildings and piers can be drilled in concrete structures. In addition, if there is a response of the metal detection sensor in the reinforcing bar search process, the first drilling process and the reinforcing bar search process are repeated until there is no response of the metal detection sensor, so it is ensured that the reinforcing bar is not arranged. Drilling can be performed after detection.

Here, as the metal detection sensor, a coil type sensor using an electromagnetic induction method that generates a magnetic field having a non-uniform intensity distribution around the axis of the detection rod is used. In which direction the rebar is arranged relative to the preliminary hole by inserting the detection rod into the hole while rotating it around the axis, or by changing the rotation angle with respect to the axis of the detection rod multiple times Can be detected.
If there is a reaction of the metal detection sensor, avoiding the direction of the reaction of the metal detection sensor and performing the first drilling process again, the next preliminary hole is surely drilled in a place where the reinforcing bar is not arranged. Therefore, it is possible to prevent unnecessary preliminary holes from being drilled. Then, the reinforcing bar search process is performed again at this position, and if there is no reaction of the metal detection sensor, along the spare hole, it is necessary to reinforce the holes for installing air conditioner pipes, buildings and piers that have a diameter larger than this spare hole. Drill the necessary holes in the concrete structure.

  When there is a reaction of the metal detection sensor, it is possible to directly drill a hole having a diameter larger than that of the preliminary hole while avoiding the direction in which the metal detection sensor has reacted. In a concrete structure, if the density of reinforcing bars is not very high, if there is a reaction of the metal detection sensor in the drilled spare hole, if the hole is drilled away from that direction, it may hit another reinforcing bar. Is low. Therefore, according to this method, since the preliminary hole is not drilled many times, the construction period can be shortened.

  The drilling device of the present invention is a drilling device that drills a hole having a diameter larger than the preliminary hole along a preliminary hole drilled in a concrete structure, and is attached to and detached from a casing provided with a bit at the tip. A guide rod that is freely mounted and can be inserted into a spare hole is provided, and the guide rod is supported at the axial center inside the casing by a support member joined to the inside of the casing by a cantilever beam. And

When the guide rod is inserted into the preliminary hole and the hole is drilled in the concrete structure with the casing bit, the force that tilts the entire drilling tool due to the reaction force of the concrete structure and the vibration due to the rotation of the casing are drilled. Occurring in the instrument, the entire drilling instrument tends to tilt or shake, and the hole to be drilled may be skewed gradually. However, according to the drilling device of the present invention, the guide rod inserted through the preliminary hole is supported at the axial center inside the casing by the support member joined to the inside of the casing by the cantilever. Since the casing does not run out against the guide rod, the hole can be drilled straight without skewing along the preliminary hole.
Further, since the guide rod inserted into the preliminary hole drilled in the concrete structure can be detachably attached to the inside of the casing, it can be applied to a conventional casing, can do.

Further, it is desirable that the tip portion of the guide bar is provided with a screwed cap portion.
Since the cap portion is screwed to the guide rod, the cap portion can freely rotate regardless of the rotation of the guide rod. Therefore, when the concrete structure is drilled with the drilling device, the cap portion does not rotate in synchronization with the casing and the guide rod even if the casing and the guide rod rotate. Therefore, wear of the guide rod can be prevented, and a load on the guide rod caused by friction between the guide rod and the preliminary hole can be reduced.

  According to the present invention, the detection rod provided with the metal detection sensor at the tip portion and the notification means for notifying the reaction when the metal detection sensor detects the reinforcing bar are provided in the deep part of the concrete structure with a simple configuration. You can search for reinforcing bars. Moreover, it is only necessary to drill a preliminary hole in the concrete structure, and it is possible to reliably search for a reinforcing bar by a simple operation. Thereby, without cutting the reinforcing bars arranged in the concrete structure, holes for piping such as an air conditioner and holes necessary for reinforcement work for buildings and piers can be drilled in the concrete structure.

(Embodiment 1)
Hereinafter, the reinforcing bar search device according to the first exemplary embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a schematic diagram of a reinforcing bar search device according to the first embodiment. FIG. 2A is a diagram showing details of the coil type sensor of the reinforcing bar searching device in the first embodiment, and FIG. 2B is a diagram showing a state of the magnetic field of the coil type sensor.

  As shown in FIG. 1, the reinforcing bar search device 1 according to the first embodiment includes a detection rod 2 provided with a coil-type sensor (hereinafter referred to as “sensor”) 3 using an electromagnetic induction method at the tip, It comprises a display unit 4a as notification means for recognizing and notifying the reaction of the sensor 3, and a measuring instrument 4 provided with a speaker unit 4b, a lamp unit 4c, and the like.

  The detection rod 2 is a hollow rod having a diameter of about 10 mm and is made of a non-magnetic material such as a resin. The detection rod 2 can be formed into a telescopic fishing rod shape, and can be expanded and contracted according to the depth of the concrete structure for which the reinforcing bar search is performed. A cord 5 for electrically connecting the sensor 3 and the measuring instrument 4 is inserted into the hollow portion of the detection rod 2.

  As shown in FIG. 2A, the sensor 3 has a configuration in which a detection coil 3b is wound around a magnet 3a serving as a sensor body. With this configuration, the magnetic field V of the sensor 3 has a concentric intensity distribution around the magnet 3a in the axial cross section of the magnet 3a (see FIG. 2B).

  When the sensor 3 moves with directionality, if a metal (in this case, a reinforcing bar arranged in a concrete structure) is present in the magnetic field of the sensor 3, an induced current flows through the metal, thereby surrounding the metal. A new magnetic field is generated. Then, an induction current flows through the detection coil 3 b by the newly generated magnetic field, and this current flows through the cord 5 to the measuring device 4.

The measuring device 4 includes some notifying means for detecting the current flowing from the detection coil 3 b via the cord 5 and notifying it.
When the measuring unit 4 detects the current flowing from the detection coil 3b, the display unit 4a displays the magnitude of the current at several levels. The user can roughly know the distance between the sensor 3 and the metal by looking at the display level of the display unit 4a.
Similarly, the loudspeaker unit 4b and the lamp unit 4c are also notified by sound or light when the measuring instrument 4 detects the current flowing from the detection coil 3b, and the magnitude of the current flowing through the measuring instrument 4 Thus, it is also possible to output the volume of sound, the brightness of light, etc. in stages.

  An initial state setting button 4d is provided on the side of the measuring instrument 4. The initial state setting button 4d is a button for setting the detection range of the sensor 3 and can be stored in the measuring device 4 when pressed when the sensor 3 is calibrated.

  Next, the punch 10 used in the first embodiment will be described with reference to the drawings. Fig.3 (a) is a side view of the punch 10 in this Embodiment 1, (b) is an axial sectional view of (a).

  As shown in FIG. 3, the punching tool 10 is a tool for drilling holes for piping such as an air conditioner and holes necessary for reinforcement work for buildings and piers in a concrete structure. The casing 11 and the casing 11 It is comprised by the guide tool 12 which can be attached or detached inside.

  An existing casing 11 can be used. In the present embodiment, a hollow body portion 11a having a diameter of about 50 mm and a plurality of diamond bits 11b provided at equal intervals on the periphery of the tip of the body portion 11a are used.

  The guide tool 12 includes a guide bar 13 that can be inserted into a preliminary hole drilled in the concrete structure, a screw-type fixing part 16 that fixes the guide bar 13 to the center position of the main body part 11a of the casing 11, and the fixing. A shaft support plate 14 that supports the end portion of the guide rod 13 opposite to the portion 16 at the center position of the main body portion 11a of the casing 11, and a spring 15 that biases the shaft support plate 14 toward the distal end of the main body portion 11a. It is comprised by.

  The guide rod 13 includes a cap portion 13a having a diameter smaller than the diameter of the preliminary hole drilled in the concrete structure at the distal end portion, and a cap portion 13a which is one of the types of screwing on the guide rod 13. ing. In addition, a notch groove 13 b is formed in the vicinity of the cap portion 13 a of the guide rod 13 so that a spanner as a fastener can be fitted when the guide rod 13 is screwed into the fixing portion 16.

  The shaft support plate 14 is a plate-like member joined to the inside of the casing 11 by a cantilever beam. The shaft support plate 14 supports the guide bar 13 at the axial center of the casing 11 and supports a load applied to the guide bar 13 during drilling. 11 can move to the bottom side of the main body 11a.

The fixing portion 16 is attached to the inner bottom surface of the main body portion 11a of the casing 11 with a cap screw so that it can be easily taken out even if the core is clogged when drilling concrete. In addition, when there is not enough space for cap screw fastening, you may screw from the side surface of the main-body part 11a.
A female screw is formed on the inner periphery of the mounting portion 16a provided at the center of the fixed portion 16, and the guide rod 13 having a male screw formed on the outer periphery can be screwed into the mounting portion 16a.

  Next, a reinforcing bar search method and a drilling method according to the first embodiment will be described with reference to the drawings. FIG. 4 is a diagram illustrating a calibration procedure of the sensor 3. FIG. 5 is a schematic cross-sectional view showing a state where the reinforcing bar search device 1 searches for a reinforcing bar. FIG. 6 is a cross-sectional view showing a case where a reinforcing bar is arranged within the range of the magnetic field V of the sensor 3. FIG. 7 is a cross-sectional view showing a state in which the punching tool punches holes.

First, before performing the reinforcing bar search, the reinforcing bar searching apparatus 1 is calibrated. For example, in the present embodiment, this is performed as follows.
As shown in FIG. 4, a reinforcing bar piece A having approximately the same diameter as a reinforcing bar arranged in the concrete structure at a position separated by a distance corresponding to the radius of a hole C (see FIG. 5) drilled in the concrete structure. Put. In the first embodiment, the diameter of the hole to be drilled is set to 50 mm, and the separation distance L is set to 30 mm. In addition, since the diameter R of the sensor 3 is 10 mm, the sensor 3 is substantially 25 mm apart. In this state, the initial state setting button 4d provided on the side of the measuring instrument 4 is pressed. Thereby, the measuring device 4 detects the current flowing from the detection coil of the sensor 3 to the measuring device 4 only when a metal exists within the separation distance L, and the display unit 4a, the speaker unit 4b, and the lamp unit 4c notify the current. Will be.

  The worker first drills a preliminary hole B from the surface of the concrete structure 30 with an existing concrete drill (see FIG. 5). This concrete drill cannot cut a reinforcing bar in normal use. Therefore, even if the operator hits the reinforcing bar while drilling the preliminary hole B, the operator can immediately notice at that time, so that the reinforcing bar is not cut by mistake. If you hit the rebar in the middle of drilling, pull out the concrete drill and drill at another location. In addition, the spare hole which became the waste hole is filled with a repair material and filled. Since the diameter of the hole to be drilled for the preliminary hole is small, only a small amount of repair material is required, and the influence on the aesthetics and the proof stress of the concrete structure 30 is extremely small.

  If the preliminary hole B is drilled so as to avoid the reinforcing bar, then the detection rod 2 of the reinforcing bar searching device 1 is inserted into the preliminary hole B. The sensor 3 emits the magnetic field V concentrically in the axial cross section. When the reinforcing bar is not arranged in the magnetic field V, no notification is given to the measuring device 4, and the operator recognizes that the reinforcing bar D is not arranged around the spare hole B. be able to.

  On the other hand, as shown in FIG. 6, when the reinforcing bar D is arranged somewhere within the range of the magnetic field V of the sensor 3, the reinforcing bar D is caused by a change in the magnetic field caused by the sensor 3 when the sensor 3 advances. Inductive current flows through. A magnetic field is newly generated around the reinforcing bar D by the induced current. Then, an induced current flows to the detection coil 3 b of the sensor 3 by this newly generated magnetic field, and this flows to the measuring instrument 4 via the cord 5. Then, the measuring instrument 4 displays the magnitude | size of an electric current on the display part 4a in steps according to the magnitude | size of an electric current. At the same time, the speaker unit 4b emits a warning sound and the lamp unit 4c is lit.

  Thus, when the reinforcing bar search device 1 detects a reinforcing bar, the detection rod 2 is pulled out from the preliminary hole B. Then, the spare hole B is filled with a repair material. Since the diameter of the preliminary hole B is small, only a small amount of repair material is required, and the effect on the aesthetics and proof stress of the concrete structure 30 is extremely small. After repairing the preliminary hole B, a new preliminary hole is drilled at a position separated from the center of the preliminary hole B by at least the radius of the magnetic field V of the sensor 3, and the detection rod 2 is inserted to check for the presence of a reinforcing bar. . This is repeated until the sensor 3 does not respond.

  As described above, when it is confirmed that the reinforcing bar D is not arranged around the drilled preliminary hole, the hole C for piping or reinforcement is drilled using the punching tool 10.

  As shown in FIG. 7, the guide rod 13 of the punch 10 is inserted into the preliminary hole B. In this state, the drilling tool 10 is operated, and the concrete structure 30 is drilled by the diamond bit 11 b of the casing 11.

When the concrete structure 30 is drilled, a force that causes the entire drilling tool 10 to tilt and vibration due to the rotation of the casing 11 are generated in the drilling tool 10 by the reaction force of the concrete structure 30. As a result, the entire punching tool 10 is likely to be tilted or shaken by vibration, which causes the holes to be drilled to be skewed gradually.
However, according to the punch 10 of the present embodiment, the guide bar 13 is inserted into the preliminary hole B, and the guide bar 13 is supported by the shaft support plate 14 so as to be positioned at the center of the main body 11a of the casing 11. Therefore, the punching tool 10 as a whole is not inclined, and no blurring occurs between the guide bar 13 and the main body 11a of the casing 11. Therefore, the punching tool 10 extends along the preliminary hole B. It is possible to drill straight without skewing.

  Further, since the cap portion 13a of the guide rod 13 is screwed to the guide rod 13 by a cap screw, the guide rod 13 can be freely rotated regardless of the rotation of the guide rod 13, and the main body portion 11a of the casing 11 and the guide Even if the rod 13 rotates, the cap portion 13a does not rotate in synchronism with it, so that it is possible to prevent the guide rod 13 and the spare hole B from being frictional and causing the guide rod 13 to wear. Further, the load on the guide bar 13 caused by the friction between the guide bar 13 and the preliminary hole B can be reduced.

  Thus, by inserting the guide rod 13 into the preliminary hole B and performing perforation, the hole C can be perforated along the preliminary hole B. Therefore, it is possible to prevent the casing 11 from skewing in the middle of the hole C. Thereby, even if the reinforcing bar D is arranged just outside the reinforcing bar detection range by the magnetic field V of the sensor 3, when the hole C is drilled by the punching tool 10, the reinforcing bar D is accidentally cut. Can be prevented.

  As described above, according to the first embodiment, simply by drilling the preliminary hole B in the concrete structure 30, it is possible to easily search even if a reinforcing bar is arranged deep in the concrete structure 30. Can do. Accordingly, since it is possible to drill the hole C in the concrete structure 30 after confirming that the reinforcing bar D is not arranged at the position where the hole C is drilled, the reinforcing bar D is damaged or cut by mistake. Can be prevented.

  Further, since the drilling tool 10 provided with the guide rod 13 can be used to drill straight along the preliminary hole B without skewing, the rebar D is mistaken in the process of drilling the hole C. Can be prevented from being damaged or cut.

  Moreover, since the reinforcing bar search apparatus 1 in this Embodiment 1 can be comprised by the detection rod 2 provided with the sensor 3, and the measuring device 4 which alert | reports the reaction, when the sensor 3 detects a reinforcing bar, A device having a simple configuration can be obtained, and the manufacturing cost of the device can be suppressed. Various kinds of existing measuring instruments 4 can be used, and any one of the display unit 4a, the speaker unit 4b, and the lamp unit 4c as a notification unit can be used. It may be.

  Further, according to the reinforcing bar search method in the present embodiment, the diameter of the spare hole B is considerably smaller than that of the hole C, so that drilling can be performed easily and in a short time without using a large-scale device. Reinforcing bars can be searched simply by inserting the detection rod 2 into the hole B, so that it can be performed in a shorter time than the conventional method, and the work period of the entire work can be shortened.

  In the first embodiment, the sensor 3 in which the detection coil 3b is wound around the magnet 3a is used. However, the present invention is not limited to this, and the transmission coil and the detection coil are wound around a metal rod. It is good also as a structure which generates a magnetic field by sending an electric current through a transmission coil.

(Embodiment 2)
Next, a reinforcing bar search device according to Embodiment 2 of the present invention will be described with reference to the drawings. Since the reinforcing bar search device according to the second embodiment and the reinforcing bar search device according to the first embodiment differ only in the sensors, the other components are denoted by the same reference numerals and description thereof is omitted. FIG. 8A is a diagram showing details of the coil-type sensor of the reinforcing bar search device according to Embodiment 2, and FIG. 8B is a diagram showing the state of the magnetic field of the coil-type sensor.

  As shown in FIG. 8A, the sensor 6 has a configuration in which a detection coil 6b is wound around a magnet 6a serving as a sensor body, and the magnet 6a is provided with a ferromagnetic body 6c such as iron. . With this configuration, the magnetic field T of the sensor 6 is decentered around the magnet 6a and has a directional intensity distribution (see FIG. 8B). As described above, in the second embodiment, the sensor 6 having the magnetic field T having an intensity distribution that is not uniform around the axis of the detection rod 2 is used.

  As a means for generating a magnetic field having a non-uniform intensity distribution around the axis of the detection rod 2 as in the sensor 6, soft iron, pure iron, and yokes are provided at both ends of the magnet 7 as shown in FIG. Alternatively, yokes 7a and 7b may be provided to form a closed circuit magnetic field U, or as shown in FIG. 10, a horseshoe-shaped magnet 8 with a biased magnetic field distribution may be used.

  Next, a reinforcing bar search method using the reinforcing bar search apparatus according to the second embodiment will be described with reference to the drawings. FIG. 11 is a cross-sectional view showing a case where a reinforcing bar is arranged within the range of the magnetic field T of the sensor 6.

As in the first embodiment, when the preliminary hole B is drilled, the detection rod 2 provided with the sensor 6 is slowly inserted into the preliminary hole B while rotating around the axis. Alternatively, the detection rod 2 is inserted and removed a plurality of times by changing the rotation angle of the detection rod 2 with respect to the axis center.
As shown in FIG. 11, the magnetic field of the sensor 6 spreads in a state protruding from the preliminary hole B only in a certain direction, and has a maximum detection distance P. Therefore, when the detection rod 2 is rotated in the rotation direction Q, the range in which the reinforcing bar can be detected is sequentially moved in the rotation direction Q around the detection rod 2. Therefore, when the sensor 6 senses the reinforcing bar D and is notified from the measuring instrument 4 when the detecting bar 2 is inserted into the spare hole B while rotating, the reinforcing bar is detected from the rotation angle of the detecting bar 2 at this time. It is possible to detect where D is in the preliminary hole B.

  In this way, by detecting the position where the reinforcing bar D is arranged with respect to the spare hole B, in the next drilling process of the spare hole, avoiding the reinforcing bar arrangement direction of the reinforcing bar D, and the spare hole. A preliminary hole E can be drilled at a position separated from B by the maximum detection distance P of the sensor 6 (see FIG. 12). As a result, when the preliminary hole E is drilled, it does not hit the reinforcing bar, so that a new preliminary hole E can be drilled in the concrete structure 30.

  Further, by detecting the position where the reinforcing bar D is arranged with respect to the spare hole B, it avoids the reinforcing bar arrangement direction of the reinforcing bar D, and is used for piping or reinforcement having a diameter larger than the preliminary hole B directly. The holes can also be drilled using existing casings with diamond bits. In particular, if the bar arrangement density of the reinforcing bar D is not so high, it is possible to drill the hole avoiding the bar arrangement direction of the reinforcing bar D without drilling the spare hole E again and confirming the arrangement of the new reinforcing bar. Since the possibility of hitting another reinforcing bar is low, a hole for piping or reinforcement can be drilled directly in the concrete structure 30.

  As described above, according to the reinforcing bar search device of the second embodiment, not only the presence of the reinforcing bar D but also the direction in which the reinforcing bar D is arranged with respect to the spare hole B can be detected. Therefore, it is possible to reduce the number of unnecessary preliminary holes, not only shorten the work process, but also prevent the concrete structure 30 from being damaged.

  INDUSTRIAL APPLICABILITY According to the present invention, it is useful as a reinforcing bar searching device and a reinforcing bar searching method for a concrete structure for detecting a reinforcing bar arranged in a concrete structure, and a hole for piping such as an air conditioner without cutting the reinforcing bar. It is useful as a drilling method and drilling tool for a concrete structure that can drill holes necessary for reinforcing work of a building or a pier in a concrete structure.

It is the schematic of the reinforcing bar search apparatus in Embodiment 1. FIG. (A) is a figure which shows the detail of the coil type sensor of the reinforcing bar search apparatus in Embodiment 1, (b) is a figure which shows the mode of the magnetic field of a coil type sensor. The side view of the punching tool in Embodiment 1, (b) is an axial sectional view of (a). It is a figure which shows the procedure of the calibration of a sensor. It is a schematic sectional drawing which shows a mode that the reinforcing bar search apparatus is searching for a reinforcing bar. It is sectional drawing which shows the case where the reinforcing bar is arranged in the range of the magnetic field of a sensor. It is sectional drawing which shows a mode that a piercing tool drills a hole. (A) is a figure which shows the detail of the coil type sensor of the reinforcing bar search apparatus in Embodiment 2, (b) is a figure which shows the mode of the magnetic field of a coil type sensor. It is the schematic which shows the coil type | mold sensor of the reinforcing bar search apparatus in other embodiment. It is the schematic which shows the coil type | mold sensor of the reinforcing bar search apparatus in other embodiment. It is sectional drawing which shows the case where the reinforcing bar is arranged in the range of the magnetic field of a sensor. It is a figure which shows the position which drills a new preliminary hole.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Rebar search apparatus 2 Detection rod 3 Sensor 3a Magnet 3b Detection coil 4 Measuring instrument 4a Display part 4b Speaker part 4c Lamp part 4d Initial state setting button 5 Code 6 Sensor 6a Magnet 6b Detection coil 6c Ferromagnetic body 7 Magnet 7a, 7b York DESCRIPTION OF SYMBOLS 8 Magnet 10 Punching tool 11 Casing 11a Main body part 11b Diamond bit 12 Guide tool 13 Guide rod 13a Cap part 13b Notch groove 14 Shaft support plate 15 Spring 16 Fixing part 16a Mounting part 30 Concrete structure A Reinforcing bar B, E Reserve hole C hole D Rebar R Diameter T, U, V Magnetic field L Separation distance P Maximum detection distance Q Rotation direction

Claims (11)

A method for searching for reinforcing bars arranged in a concrete structure,
A first drilling step of drilling a preliminary hole in a concrete structure with a concrete drill;
Reinforcing bar search step of inserting a detection rod provided with a metal detection sensor at the tip into the preliminary hole and examining the presence or absence of reaction of the metal detection sensor ,
When there is no reaction of the metal detection sensor, the preliminary hole drills a hole having a diameter larger than the preliminary hole along the preliminary hole, and when there is a reaction of the metal detection sensor, the metal detection sensor A method of searching for a reinforcing bar for a concrete structure , characterized in that the first drilling step and the reinforcing bar searching step are performed while avoiding a reacted direction .   2. The method for searching for reinforcing bars in a concrete structure according to claim 1, wherein a coil type sensor using an electromagnetic induction method is used as the metal detection sensor. The coil-type sensor emits a magnetic field having a non-uniform intensity distribution around the axis of the detection rod,
3. The concrete structure according to claim 2, wherein the detection rod is inserted into the preliminary hole while being rotated about an axis, or is inserted / removed a plurality of times by changing a rotation angle with respect to the axis of the detection rod. Rebar search method. A detection rod provided with a metal detection sensor at the tip, and inserted into a preliminary hole drilled in a concrete structure;
Informing means for informing when the metal sensing sensor senses a reinforcing bar ,
The detection rod is inserted into a preliminary hole drilled in the concrete structure to check the presence or absence of the reaction of the metal detection sensor. If there is no response of the metal detection sensor, the preliminary detection hole is moved along the preliminary hole from the preliminary hole. When a hole with a large diameter is drilled and the response of the metal detection sensor is present, avoiding the direction in which the metal detection sensor has reacted, drilling a preliminary hole again and inserting the detection rod into the reaction of the metal detection sensor Reinforcing bar search device for concrete structures to check for presence or absence .   The apparatus for searching for reinforcing bars in a concrete structure according to claim 4, wherein the metal detection sensor is a coil-type sensor using an electromagnetic induction method.   6. The apparatus for searching for a reinforcing bar in a concrete structure according to claim 5, wherein the coil-type sensor emits a magnetic field having a non-uniform intensity distribution around the axis of the detection rod. A method of drilling holes in a concrete structure where there are no reinforcing bars,
A first drilling step of drilling a preliminary hole in a concrete structure with a concrete drill;
In the pre-hole, inserting the detection rod provided with a metal detection sensor in the distal end portion, and a reinforcing bar searching step to check for reaction of the metal detection sensor,
When there is no reaction of the metal detection sensor, a hole having a diameter larger than the spare hole is drilled along the spare hole,
When there is a response from the metal detection sensor, the first drilling step and the reinforcing bar searching step are further performed while avoiding the direction in which the metal detection sensor has reacted . As the metal detection sensor, a coil type sensor using an electromagnetic induction method, which uses a coil type sensor that emits a magnetic field having a non-uniform intensity distribution around the axis of the detection rod,
In the reinforcing bar search step, the detection hole is inserted into the spare hole while rotating around the shaft center, or the rotation angle with respect to the shaft center of the detection rod is changed a plurality of times,
When there is no reaction of the metal detection sensor, a hole having a diameter larger than the spare hole is drilled along the spare hole,
8. The method for drilling a concrete structure according to claim 7, wherein when there is a response from the metal detection sensor, the first drilling step is performed again while avoiding a direction in which the metal detection sensor has reacted. As the metal detection sensor, a coil type sensor using an electromagnetic induction method, which uses a coil type sensor that emits a magnetic field having a non-uniform intensity distribution around the axis of the detection rod,
In the reinforcing bar search step, the detection hole is inserted into the preliminary hole while rotating the detection rod about the axis, or the rotation angle with respect to the axis of the detection rod is changed a plurality of times,
8. The method for drilling a concrete structure according to claim 7, wherein when there is a reaction of the metal detection sensor, a hole having a diameter larger than the preliminary hole is drilled avoiding a direction in which the metal detection sensor has reacted. A detection rod provided with a metal sensor at the tip is inserted into a spare hole drilled in the concrete structure to check whether the metal sensor is responding. If there is no reaction of the metal sensor, the spare A hole having a diameter larger than that of the preliminary hole is drilled along the hole, and when there is a reaction of the metal detection sensor, the preliminary detection of the preliminary hole and the detection rod are performed again while avoiding the direction in which the metal detection sensor has reacted. A perforating instrument for inserting a slab to check the presence or absence of reaction of the metal sensing sensor ,
Removably attached to the inside of the casing provided with a bit at the tip, and provided with a guide rod that can be inserted into the spare hole,
The drilling instrument according to claim 1, wherein the guide bar is supported at the axial center inside the casing by a support member joined to the inside of the casing by a cantilever.   The piercing device according to claim 10, wherein a tip of the guide rod is provided with a screwed cap.

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