JP7449209B2 - Method and device for detecting the connection port position of existing pipes - Google Patents

Description

The present invention relates to a method and apparatus for detecting the position of a connection port for connecting a branch pipe in an existing pipe from inside the rehabilitated pipe after lining the inner wall of the existing pipe with the rehabilitated pipe.

A connection port is formed in an existing pipe such as a sewer pipe, and a branch pipe is connected to this connection port. When an existing pipe becomes obsolete, it can be rehabilitated by lining it with a rehabilitation pipe, but when the rehabilitation pipe is lined, the connection port of the existing pipe is blocked by the rehabilitation pipe, so a communication port connected to the connection port is added to the rehabilitation pipe. need to be formed.

When forming a communication port from the inside of a rehabilitated pipe, it is necessary to accurately detect the position of the connection port blocked by the rehabilitated pipe in advance. The connection port position detection device disclosed in Patent Document 1 applies vibration to a rehabilitated pipe and detects a change in detection output due to a difference in propagation of vibration between a location corresponding to the connection port and a location not corresponding to the connection port. The position of the connection port is detected based on the

Japanese Patent Application Publication No. 2000-65556

Since the detection device of Patent Document 1 uses vibration, if there is a gap between the existing pipe and the rehabilitated pipe, there will be a difference in detection output between the location corresponding to the connection port and the location corresponding to the connection port in the rehabilitation pipe. The position of the connection port cannot be detected.

In order to solve the above problems, the present invention provides a method in which an existing pipe of a reinforced concrete structure having a connection port for connecting a branch pipe is lined with a rehabilitation pipe, and the connection port is blocked by the rehabilitation pipe. In the method of detecting the position of the connection port from inside the rehabilitated pipe,
A cut point of the reinforcing bar of the existing pipe is detected by electromagnetic detection means arranged inside the rehabilitated pipe, and the position of the connection port is determined based on the detected information of the cut point.
According to the above configuration, by using the electromagnetic detection means, the position of the connection port can be detected even if a gap is formed between the rehabilitated pipe and the existing pipe.

Preferably, the electromagnetic detection means is moved along the reinforcing bars, and the position of the connection port is determined based on detection information of the positions of two cutting points at the cutting location of at least one reinforcing bar.
According to the above configuration, the position of the connection port can be accurately detected based on the position of the connection point.

Preferably, the diameter of the connection port is known, and the position of the connection port is determined based on the detected positions of two cutting points of at least one reinforcing bar and the diameter of the connection port.
More preferably, the reinforcing bars are arranged at known intervals in the axial direction or the circumferential direction of the pipe, and the detected positions of two cutting points of at least one reinforcing bar, the diameter of the connection port, and the The position of the connection port is determined based on the spacing information.
With the above configuration, the accuracy of detecting the position of the connection point can be improved.

In one specific aspect, when the diameter of the connection port is D and the interval between the reinforcing bars is L, the connection port cuts only one reinforcing bar when the condition L<D<2L is satisfied; Assuming that the peripheral edge of the connection port is in contact with one of the reinforcing bars adjacent to the one reinforcing bar, the distance between the cutting points formed on the one reinforcing bar is set as the reference distance, and If the distance between the two cutting points is greater than or equal to the reference distance, the center position between the two cutting points is determined as the position of the connection port.
If the distance between the cutting points is greater than or equal to the reference distance, no cutting points are formed on the reinforcing bars on both sides of the adjacent reinforcing bars. Therefore, since the center position of the connection port cannot be specified as one, the center of the overlapping portion of two possible connection port formation regions is determined as the connection port position. Thereby, drilling can be performed reliably.

In the specific aspect described above, preferably, when the distance between the two cutting points is shorter than the reference distance, on the condition that one of the adjacent reinforcing bars is not cut, Without detecting the cut point of the other of the reinforcing bars, the center position of the connection port is calculated closer to the other reinforcing bar based on the detected positions of the two cut points and the diameter D of the connection port, and this The calculated center position is determined as the position of the connection port.
When the distance between the cutting points is shorter than the reference distance, if a cutting point is not formed on one of the adjacent reinforcing bars, a cutting point is also formed on the other. In this case, the center position of the connection port can be determined based on the detected position of the cut point of the reinforcing bar and the diameter of the connection port, and the process of detecting the cut point of the other reinforcing bar can be omitted, so the work of detecting the location of the connection port can be omitted. can be done efficiently.

In another specific aspect, when the diameter of the connection port is D and the interval between the reinforcing bars is L, when two cutting points are detected in one reinforcing bar when the condition D>2L is satisfied. is, on the condition that one of the reinforcing bars adjacent to the one reinforcing bar in question is not cut, the two cuts are made without detecting the cut point of the other of the adjacent reinforcing bars. Based on the detected position of the point and the diameter D of the connection port, the center position of the connection port is calculated closer to the other reinforcing bar, and this calculated center position is determined as the position of the connection port.
According to this configuration, the process of detecting the cutting point of the other of the adjacent reinforcing bars can be omitted, so that the work of detecting the position of the connection port can be performed efficiently.

In order to accurately detect the connection position, the center position of the connection port is calculated based on the detected positions of the two cutting points of each of the two reinforcing bars, and this calculated center position is used as the position of the connection port. You can also decide.

One embodiment of the electromagnetic detection means is an electromagnetic induction type detection means. This electromagnetic induction type detection means includes an excitation coil, a detection coil, and an alternating current supplied to the excitation coil to generate a magnetic flux passing through the reinforcing steel in the excitation coil, and based on changes in the current or voltage of the detection coil. and a control calculation unit that detects a cutting location of the reinforcing steel.

Another aspect of the electromagnetic detection means is an electromagnetic wave radar. This electromagnetic wave radar radiates electromagnetic waves towards the existing pipe and detects the cut point of the reinforcing bars by receiving the reflection of the electromagnetic waves from the reinforcing bars.

Another aspect of the present invention is that a rehabilitated pipe is lined with an existing pipe having a reinforced concrete structure having a connection port for connecting a branch pipe, and that the rehabilitation pipe is In a device for detecting the position of the connection port from inside,
a traveling body that moves along the pipe axis of the rehabilitated pipe;
a rotating part rotatably supported by the traveling body around an axis extending in the tube axis direction;
an electromagnetic detection means supported by the rotating part;
a distance sensor that detects a travel distance of the traveling body;
a rotation angle sensor that detects the rotation angle of the electromagnetic detection means;
an arithmetic unit;
The calculation unit detects the reinforcing bars based on a change in the detection output from the electromagnetic detecting unit during the process in which the electromagnetic detecting unit moves in the circumferential direction along the annular reinforcing bars of the existing pipe by the rotating unit. detect the cutting point, obtain detection information of the position of the cutting point in the tube axis direction and the angular position in the tube circumferential direction from the distance sensor and the rotation angle sensor, and detect the connection port based on the detection information of the cutting point. Determine the position in the tube axis direction and the angular position in the tube circumferential direction.

Preferably, the rotary part is provided with a perforation part so as to be movable in a radial direction with respect to the rehabilitation pipe.
According to this configuration, following the detection of the position of the connection port, the rehabilitation pipe can be bored to form the communication port.

According to the present invention, a new means for detecting the position of the connection port can be provided. Further, even if a gap is formed between the rehabilitated pipe and the existing pipe, the position of the connection port can be detected.

FIG. 2 is a schematic vertical cross-sectional view showing a method for detecting the position of a connection port in an existing pipe according to an embodiment of the present invention, and is a mobile drilling device equipped with a magnetic induction type detection means inside the rehabilitated pipe after lining the existing pipe with a rehabilitated pipe. This shows the process of moving the vehicle to the vicinity of the detection start position. FIG. 2 is a diagram corresponding to FIG. 1 showing a process of detecting the cutting situation of the second reinforcing bar after detecting the cutting situation of the first reinforcing bar by the electromagnetic induction type detection means. FIG. 2 is a diagram corresponding to FIG. 1 showing a process of detecting the cutting state of the third reinforcing bar by an electromagnetic induction type detection means. FIG. 1 is a diagram corresponding to FIG. 1 showing a process of forming a communication port by drilling a hole in the rehabilitated pipe in accordance with the detected position of the connection port without detecting the cutting state of the fourth reinforcing bar by the electromagnetic induction detection means; . FIG. 2 is an enlarged cross-sectional view taken along line VV in FIG. 1. FIG. FIG. 3 is a circuit diagram of an electromagnetic induction type detection means. FIG. 7 is a schematic plan view showing a first aspect of the connection port when the relationship between the diameter D of the connection port and the reinforcing bar interval L satisfies the condition L<D<2L. It is a schematic plan view which shows the 2nd aspect of a connection port under the same conditions. It is a schematic plan view which shows the 3rd aspect of a connection port under the same conditions. It is a schematic plan view which shows the 4th aspect of a connection port under the same conditions. FIG. 7 is a schematic plan view showing one aspect of the connection port when the relationship between the diameter D of the connection port and the reinforcing bar interval L satisfies the condition D>2L. FIG. 7 is a circuit diagram showing a modification of the electromagnetic induction type detection means.

Hereinafter, one embodiment of the present invention will be described with reference to the drawings.
Outline of existing pipe rehabilitation work
As shown in FIG. 1, an existing pipe 1 to be rehabilitated is, for example, an old underground sewer pipe, and has a reinforced concrete structure. That is, as shown in FIGS. 1 and 5, there are circular ring (annular) reinforcing bars 2 arranged at predetermined intervals along the tube axis direction, and linear reinforcing bars 3 (ring-shaped) arranged at predetermined intervals in the circumferential direction. The existing pipe 1 is constructed by embedding pipes (shown only in FIG. 5) in concrete 4 in a grid-like connected state. The inner diameter of the existing pipe 1 is so large that a person cannot directly enter it, and is, for example, 800 mm or less. One or more connection ports 5 are formed in the middle of the existing pipe 1, and a branch pipe 6 is connected to each connection port 5. Both ends of the existing pipe 1 are connected to a manhole (not shown).

The inner wall of the existing pipe 1 is lined with a rehabilitation pipe 8. The rehabilitation pipe 8 is constructed by, for example, spirally winding a band-like member made of synthetic resin, and fitting the edges of adjacent wound portions together. The rehabilitated pipe 8 can take various forms, and may be constructed by connecting annular strips, or by curing a resin tube with shape memory, a multilayer sheet such as a nonwoven fabric, or a glass fiber sheet with resin. It may be something like that. The connection port 5 of the existing pipe 1 is closed by lining the rehabilitated pipe 8.

After lining the rehabilitated pipe 8, a hole is bored in the rehabilitated pipe 8 at a position corresponding to the connection port 5 of the existing pipe 1, thereby forming a communication port (not shown) that continues to the connection port 5. Thereby, the branch pipe 3 is communicated with the inside of the rehabilitation pipe 8.

Configuration of Mobile Imaging Device and Mobile Perforation Device In order to accurately detect the position of the connection port 5 covered by the rehabilitation pipe 8 and punch the rehabilitation pipe 8 to form a communication port, a mobile imaging device 10 shown in FIG. 1 is used. and a mobile drilling device 20 (connection port position detection device) are used.
The mobile imaging device 10 (position detection device) includes a traveling body 11 and a video camera 12 (imaging means) mounted on the traveling body 11.

The mobile drilling device 20 includes a traveling body 21, a fixing jack 22 provided on the traveling body 21, and a rotating part 23 supported by the traveling body 21 so as to be rotatable about an axis extending in the front-rear direction (pipe axis direction). The basic structure includes an elevating section 24 supported by a rotating section 23 so as to be movable up and down, a support column 25 erected on the elevating section 24, and a perforation section 26 provided at the upper end of the support section 25. The fixing jack has an X-shape and can be extended and contracted up and down.

The movable drilling device 20 of the present embodiment further includes a support arm 27 that is vertically rotatably supported by a support column 25, a sensor probe 28 provided at the tip of the support arm 27, and a sensor probe 28 attached to the sensor probe 28. It includes a distance sensor 29 and a sensor box 30. The distance sensor 29 includes, for example, a roller that contacts the inner surface of the rehabilitation pipe 8 and rotates as the traveling body 21 travels, and a rotary encoder that detects the rotation of this roller. A display 31 is provided on the front of the sensor box 30. The control box 30 also includes built-in sensors such as a rotation angle sensor 35.

As shown in FIG. 6, the mobile drilling device 20 is equipped with an electromagnetic induction type detection means 40 (electromagnetic detection means) for detecting the cut location of the reinforcing bar 2. This electromagnetic induction detection means 40 includes an excitation coil 41 and a detection coil 42 built into the sensor probe 28, an excitation circuit 43, a detection circuit 44, and a control calculation section 45 (calculation section) built into the control box 30. have. The excitation circuit 43 supplies an alternating current to the excitation circuit 41 in response to a command signal from the control calculation unit 45 to pass a magnetic flux through the reinforcing bar 2, and detects a current flowing through the detection coil 42 corresponding to a change in the magnetic flux of the reinforcing bar 2. Alternatively, the voltage is detected by the detection circuit 44 and the detection signal is sent to the control calculation section 45.
In addition to the detection output from the detection circuit 44, the control calculation unit 45 also receives information on the travel distance from the distance sensor 29 and rotation angle information from the rotation angle sensor 35.

Connection Port Position Detection Work In this embodiment, the spacing L between the reinforcing bars 2 is constant and is known from a reinforcement design drawing or the like. The diameter D of the connection port 5 is known through a prior investigation using the mobile imaging device 10 or the like. The approximate position of the connection port 5 is also known by measuring it with the mobile imaging device 10 in advance. In this embodiment, the distance is known as the distance from the right end of the existing pipe 1.
In this embodiment, operators of the mobile imaging device 10 and the mobile drilling device 20 (position detecting device) work together at a base station on the ground to detect the position of the connection port 5. The details will be explained below.

As shown in FIG. 1, the mobile imaging device 10 is run from the right end of the existing pipe 1, and is placed within the field of view of the video camera from the center position of the connection port 5 to the measurement start position (specifically, the measurement start position of the connection port 5). The mobile imaging device 10 is stopped when it reaches a position where an image of the rehabilitation tube 8 in a range from the center position to a position (2L+D/2) leftward in the figure is captured.

Next, the mobile drilling device 20 is run from the left end of the existing pipe 1. The image of the video camera 12 of the mobile imaging device 10 is monitored on the monitor of the base station, and when the sensor probe 28 reaches the detection start position as shown in FIG. 1, the mobile drilling device 20 is stopped. Note that the mobile drilling device 20 may control its travel based on information on the distance traveled from the left end of the existing pipe 1, without relying on the video information from the mobile imaging device 10.

In FIG. 1, four reinforcing bars located in the forward direction (to the right in the figure) from the measurement start position among the reinforcing bars 2 are shown as "a" to "d" after the code "2" for convenience of explanation later. ” sign is added. Note that when these reinforcing bars 2a to 2d are described without being distinguished from each other, the reference numeral "2" is used.
There is almost no possibility that the reinforcing bar 2a is cut by the connection port 5. It is assumed that the reinforcing bar 2c is cut closest to the center of the connection port 5, and the reinforcing bars 2b and 2d on both sides thereof may also be cut.

When the mobile drilling device 20 is advanced from the detection start position, the sensor probe 28 detects the reinforcing bar 2a. As shown in FIG. 5, the rotating part 23 is driven to swing the sensor probe 28 in the circumferential direction along the reinforcing bar 2a over a predetermined angle range, and in this process, the control calculation part 45 of the electromagnetic induction detection means 40 The detection output from the detection circuit 43 (the amplitude of the current or voltage detected by the detection coil 44) is monitored, and based on this detection output, it is determined whether or not the reinforcing bar 2a is cut, and if it is cut, the position of the cutting point is determined. To detect.
Next, as shown in FIGS. 2 and 3, the movable drilling device 20 is moved forward by the reinforcing bar interval L based on the information from the distance sensor 29, and the rotating part 23 is driven in the same manner as described above to move the sensor probe 28 to the reinforcing bar 2b. , 2c, and 2d, and in this process, the electromagnetic induction detection means 40 determines whether or not the reinforcing bars 2b, 2c, and 2d are cut, and if they are cut, the cutting point is detected.

When the reinforcing bar 2 is cut by the connection port 5, two cutting points are formed. The detection output at the reinforcing bar 2 is constant, but the detection output at the cut location changes. If the swing speed is low, the center between the cutting points will have the greatest amount of change. The control calculation unit 45 compares this changed detection output with a threshold value (a value close to the detection output at the reinforcing bar 2), and recognizes the point exceeding the threshold value as a cutting point. Note that when the swing speed is high, two cutting points are detected as the maximum values of the amount of change in the detection output. The control calculation unit 45 may calculate the distance to the reinforcing bar 2 based on the detection output. In this case, the calculated distance is constant when reinforcing bars are present, but increases at the cut location. The point where the calculated distance exceeds the threshold is detected as a cutting point.

When the reinforcing bar 2 is cut, two cutting points are always formed, but if the cutting points are very close, the detection output appears to represent one cutting point. In this case, the control calculation unit 45 recognizes that there are two adjacent cutting points.
Since the electromagnetic induction detection means 40 uses magnetic flux, even if a gap (air layer) is formed between the existing pipe 1 and the rehabilitated pipe 2, the magnetic flux can pass through the reinforcing bars 2, and the reinforcing bars can be cut. Points can be detected.

When the control calculation unit 45 detects the cutting point, it recognizes the rotation angle of the sensor probe 28 detected by the rotation angle sensor 35 as the angular position of the cutting point. Further, the position of the reinforcing bar 2 in the tube axis direction where the cutting point has been detected (that is, the position of the cutting point in the tube axis direction) is recognized based on the distance information from the distance sensor 29. The control calculation unit 45 calculates the position of the cutting point on the cylindrical surface on which the reinforcing bars 2 are arranged, based on the angular position and the position in the tube axis direction of the cutting point.

Hereinafter, a process in which the control calculation unit 45 detects the position of the connection port 5 from the position of the cutting point of the reinforcing bar 2 will be explained in detail. First, a case where the known diameter D of the connection port 5 and the known distance L between the reinforcing bars 2 satisfy the condition L<D<2D will be described with reference to FIGS. 7A to 7D.

When the above condition of L<D<2D is satisfied, the detection method differs depending on the distance X between the connection points 2x and 2x. In addition, this distance X is calculated|required from the following formula.
X=2Rsin(Θ/2)
However, R is the radius of the cylindrical surface on which the reinforcing bars 2 are arranged, and is the sum of the radius of the inner circumference of the existing pipe 1 and the cover thickness of the concrete 4. Θ is the angular spacing between the cutting points 2x, 2x.

Prior to detecting the position of the connection port 5, the reference distance _XR is set as follows. In FIG. 7A, only one reinforcing bar, for example, reinforcing bar 2c, is cut by the connection port 5, and the adjacent reinforcing bars 2b and 2d are not cut, and furthermore, the peripheral edge of the connection port 5 is in contact with either of the neighboring reinforcing bars 2b, 2d. (More specifically, a case where the reinforcing bars 2b and 2c are partially cut off by the connection port 5) is shown. In FIG. 7A, the connection port 5 in contact with the reinforcing bar 2d is shown by a solid line, and the connection port 5 in contact with the reinforcing bar 2b is shown in a broken line. In this case, the distance X between the two cutting points 2x, 2x of the reinforcing bar 2b is defined as the reference distance _XR . The reference distance _XR can be expressed by the following formula.

When the distance X between the cutting points 2x and 2x is the reference distance _XR , there is no cutting point between the adjacent reinforcing bars 2b and 2d. Therefore, it cannot be determined from only the position information of the cutting points 2x, 2x whether the connection port 5 is formed closer to the reinforcing bar 2d as shown by the solid line or closer to the reinforcing bar 2b as shown by the broken line. In this case, the center between the cutting points 2x, 2x (that is, the center of the area where the two circular regions overlap) is determined as the position P of the connection port 5. This position P becomes the center of the drilling described later. A circle 5a inscribed in the solid line circle and the broken line circle representing the connection port 5 indicates the maximum area that can be drilled, and the diameter of the inscribed circle 5a represents the maximum value of the diameter that can be drilled. Therefore, the diameter of the perforated portion 26 needs to be smaller than the diameter of this inscribed circle 5a.
Note that the radius d of the inscribed circle 5a can be determined from the following equation.
d=2(DL)

鉄筋２ｂで切断点を検出せず、図７Ａ，図７Ｂに示すように鉄筋２ｃで切断点２ｘ、２ｘを検出し、この切断点２ｘ、２ｘ間の距離Ｘが基準距離Ｘ_Ｒ以上である場合には、接続口５の位置を上記のようにして決定し、鉄筋２ｄでの切断点検出工程を実行しない。 As shown in FIG. 7B, when the connection port 5 moves away from the position where it touches the reinforcing bars 2b or 2d and its center approaches the reinforcing bars 2c, the distance X between the cutting points 2x and 2x is smaller than the reference distance _XR . become longer. Also in this case, the cutting points 2x, 2x are formed only on one reinforcing bar 2c. Therefore, similarly to FIG. 7A, the center point P between the cutting points 2x and 2x is determined as the position of the connection port 5. Note that the diameter of a circle inscribed in the two circles representing the connection port 5 in this case can be expressed by the following equation.

When the cutting point is not detected with the reinforcing bar 2b, but the cutting points 2x and 2x are detected with the reinforcing bar 2c as shown in FIGS. 7A and 7B, and the distance X between the cutting points 2x and 2x is greater than or equal to the reference distance _XR . In this case, the position of the connection port 5 is determined as described above, and the step of detecting the cutting point at the reinforcing bar 2d is not performed.

As shown in FIG. 7C, when the center of the connection port 5 is on the extension line of the reinforcing bars 2b, the distance X between the cutting points 2x and 2x of the reinforcing bars _2b is longer than the reference distance (equal to the diameter D of the opening 5). In this case, similarly to the above, the center between the cutting points 2x, 2x is determined as the position P of the connection port 5. The position P coincides with the center of the connection port 5.

As shown in FIG. 7D, when the connection port 5 cuts two reinforcing bars, for example, reinforcing bars 2c and 2d, the distance X between the cutting points 2x and 2x of the reinforcing bar 2c and the distance X between the cutting points 2x and 2x of the reinforcing bar 2d are both shorter than the reference distance _XR . In this case, after confirming that the reinforcing bar 2b was not cut, two cutting points 2x and 2x were detected on the reinforcing bar 2c, and the distance X between the cutting points 2x and 2x was determined to be shorter than the reference distance _XR . At this stage, the position of the connection port 5 can be determined as follows, and subsequent detection of the cutting point of the reinforcing bar 2d can be omitted.

As shown in FIG. 7D, when the distance X is shorter than the reference distance _XR , the position of the connection port 5 can be determined by the two cutting points 2x, 2x and the reinforcing bar diameter D. That is, if cutting points 2x, 2x are detected in the reinforcing bar 2c without detecting cutting in the reinforcing bar 2b, there should always be cutting points 2x, 2x in the reinforcing bar 2d. In other words, the center of the connection port 5 must be located closer to the reinforcing bar 2d than the reinforcing bar 2c. Therefore, the connection port 5 can be specified from the information on the two cutting points 2x, 2x of the reinforcing bar 2c and the diameter D, and the center position thereof can be determined as the position of the connection port 5. Specifically, the distance A from the center point between the cutting points 2x and 2x to the center of the connection port 5 is determined from the following equation.

In the case of FIG. 7D, the cutting points 2x, 2x of the reinforcing bar 2d may be further detected, and the center of the connection port 5 may be determined as the position P of the connection port 5 based on the positions of a total of four cutting points 2x. Note that by using the known diameter D, the position P of the connection port 5 can be determined more accurately.

If the error in the detection position of the cutting point is large, the cutting point is detected with only one reinforcing bar, and if the cutting point cannot be detected with the next reinforcing bar, the center of the two cutting points is connected in the same way as described above. When the position of the opening 5 is determined and the cutting point is detected between two reinforcing bars, the center of the spacing between the reinforcing bars may be regarded as the center of the connecting opening 5.

Next, a case where the reinforcing bar diameter D and the reinforcing bar spacing L have a relationship of D>2L will be described with reference to FIG. 8. In this case, two reinforcing bars, for example, reinforcing bars 2c and 2d, are always cut by the connection port 5. Similarly to the above, if the cutting point is not detected for the reinforcing bar 2b but is detected for the reinforcing bar 2c, it is clear that the next reinforcing bar 2d is cut and the center of the connection port 5 is located closer to the reinforcing bar 2d. Therefore, the center of the connection port 5 can be determined as the position P of the connection port 5 based on the positions of the two cutting points 2x and 2x of the reinforcing bar 2c and the reinforcing bar diameter D without detecting the cutting situation of the next reinforcing bar 2d. Can be done.

In the case of FIG. 8, the cutting points 2x, 2x of the reinforcing bar 2d may be further detected, and the center of the connection port 5 may be determined as the position P of the connection port 5 based on the positions of a total of four cutting points 2x. By using the known diameter D, the position P of the connection port 5 can be determined more accurately.

Drilling operation Next, as shown in FIG. 4, a communication port is formed by drilling a hole in the rehabilitated pipe 8 in accordance with the position of the detected connection port 5. More specifically, the control calculation unit 45 displays the position P of the connection port 5 on the display 31 as a position in the tube axis direction and an angular position in the circumferential direction. The operator of the mobile imaging device 10 images the position information of the connection port 5 displayed on the display 31 and conveys the image to the operator of the mobile drilling device 20. The operator runs the traveling body 21 by remote control while viewing the travel distance information from the distance sensor 29 on a monitor until the center position of the perforation 26 coincides with the position of the connection port 5 in the tube axis direction. Next, by extending the fixing jack 22 and abutting it against the top wall of the rehabilitated pipe 5, the movable perforation device 20 is fixed to the rehabilitated pipe 5 and, in turn, to the existing pipe 1. Next, while viewing the circumferential angle information from the rotation angle sensor 29 on a monitor, the rotating section 23 is remotely operated to align the center of the perforation 26 with the circumferential angular position of the connection port 5 . Finally, the elevating section 24 is driven to move the perforation section 16 toward the rehabilitated pipe 8 and perform the perforation. This drilling operation is carried out under the supervision of the mobile imaging means 10.

The present invention is not limited to the embodiments described above, and various modifications can be made without departing from the spirit thereof.
As shown in FIG. 9, the electromagnetic induction type detection means 40A is an excitation/detection coil that doubles as the excitation coil 41 and the detection coil 42 of the electromagnetic induction type detection means 40 of the above embodiment (that is, it substantially includes both). 49 may also be used. In this case, an excitation circuit 43 and a detection circuit 44 are connected to the excitation/detection coil 49 .
The electromagnetic detection means may be an electromagnetic radar means. This electromagnetic radar means emits electromagnetic waves toward the reinforcing bars of the existing pipe, and detects where the reinforcing bars are cut by receiving the reflection of the electromagnetic waves from the reinforcing bars. Detect points.
The annular reinforcing bar may be a circular ring-shaped reinforcing bar, or may be one spirally wound reinforcing bar.
Instead of the annular reinforcing bars, the cutting points of reinforcing bars arranged at intervals in the pipe circumferential direction and extending linearly in the tube axis direction may be detected.
The existing pipe is not limited to a sewer pipe, but may be a water pipe, an agricultural water pipe, a gas pipe, or the like.

The present invention can be applied, for example, to rehabilitation of aging sewer pipes.

1 Existing pipes 2, 2a to 2d Annular reinforcing bars 2x Cutting point 3 Straight reinforcing bars 4 Concrete 5 Connection port 6 Branch pipe 8 Rehabilitation pipe 20 Mobile drilling device (connection port position detection device)
21 Traveling body 23 Rotating part 26 Perforated part 29 Distance sensor 35 Rotation angle sensor 40 Electromagnetic induction type detection means (electromagnetic detection means)
41 Excitation coil 42 Detection coil 45 Control calculation section (calculation section)

Claims (11)

A rehabilitated pipe is lined with an existing pipe of reinforced concrete structure that has a connection port for connecting a branch pipe, and the connection port is blocked by the rehabilitated pipe, and the location of the connection port is determined from inside the rehabilitated pipe. In the method of detecting
The electromagnetic detection means disposed inside the rehabilitated pipe is moved along the reinforcing bars of the existing pipe, and based on the detection information of the positions of two cutting points at the cut point of at least one reinforcing bar, the A method for detecting the position of a connection port of an existing pipe, the method comprising determining the position. the diameter of the connection port is known;
2. The position of the connection port of an existing pipe according to claim 1 , wherein the position of the connection port is determined based on the detected positions of two cutting points of at least one reinforcing bar and the diameter of the connection port. Detection method. The reinforcing bars are arranged at known intervals in the axial direction or circumferential direction of the pipe,
3. The position of the connection port is determined based on information about detected positions of two cutting points of at least one reinforcing bar, a diameter of the connection port, and an interval between the reinforcing bars. A method for detecting the connection port position of existing pipes. When the diameter of the connection port is D and the interval between the reinforcing bars is L, when the condition L<D<2L is satisfied,
A cut formed in one reinforcing bar when the connection port cuts only one reinforcing bar, and the peripheral edge of the connection port is in contact with one of the reinforcing bars adjacent to the one reinforcing bar. Set the distance between points as the reference distance,
If the distance between the two cutting points is equal to or greater than the reference distance, a central position between the two cutting points is determined as the position of the connection port. Method for detecting the position of a pipe connection port. If the distance between the two cutting points is shorter than the reference distance, cutting the other of the adjacent reinforcing bars, provided that one of the adjacent reinforcing bars is not cut. Without detecting the location, calculate the center position of the connection port closer to the other reinforcing bar based on the detected positions of the two cutting points and the diameter D of the connection port, and use this calculated center position as the connection port. 5. The method for detecting the position of a connection port of an existing pipe according to claim 4 , wherein the position is determined as the position of the connection port of an existing pipe. When the diameter of the connection port is D and the interval between the reinforcing bars is L, if the condition D>2L is satisfied,
When two cutting points are detected in one reinforcing bar, on the condition that one of the reinforcing bars adjacent to the one reinforcing bar is not cut, the other of the neighboring reinforcing bars is not cut. Without detecting the cut point of the reinforcing bar, calculate the center position of the connection port closer to the other reinforcing bar based on the detected positions of the two cut points and the diameter D of the connection port, and calculate the calculated center position. 4. The method for detecting the position of a connection port of an existing pipe according to claim 3 , characterized in that the position of the connection port is determined as the position of the connection port. Claim characterized in that the center position of the connection port is calculated based on the detected positions of two cutting points of each of the two reinforcing bars, and the calculated center position is determined as the position of the connection port. The method for detecting the connection port position of an existing pipe according to 1 or 2 . The electromagnetic detection means includes an electromagnetic induction type detection means, and the electromagnetic induction type detection means generates a magnetic flux passing through the reinforcing steel in the excitation coil by supplying an alternating current to an excitation coil, a detection coil, and the excitation coil. 8. The existing pipe according to claim 1, further comprising: a control calculation unit that detects the cut point of the reinforcing bar based on a change in the current or voltage of the detection coil. How to detect the connection port position. The electromagnetic detection means comprises an electromagnetic wave radar, and the electromagnetic wave radar detects the cut point of the reinforcing bar by emitting electromagnetic waves towards the existing pipe and receiving reflection of the electromagnetic waves from the reinforcing bar. A method for detecting a connection port position of an existing pipe according to any one of claims 1 to 7 . A rehabilitated pipe is lined with an existing pipe of reinforced concrete structure having a connection port for connecting a branch pipe, and with the connection port blocked by the rehabilitated pipe, the position of the connection port is determined from inside the rehabilitated pipe. In the detecting device,
a traveling body that moves along the pipe axis of the rehabilitated pipe;
a rotating part rotatably supported by the traveling body around an axis extending in the axial direction;
an electromagnetic detection means supported by the rotating part;
a distance sensor that detects a travel distance of the traveling body;
a rotation angle sensor that detects the rotation angle of the electromagnetic detection means;
an arithmetic unit;
The calculation unit detects the reinforcing bars based on a change in the detection output from the electromagnetic detecting unit during the process in which the electromagnetic detecting unit moves in the circumferential direction along the annular reinforcing bars of the existing pipe by the rotating unit. detect the cutting point, obtain detection information of the position of the cutting point in the tube axis direction and the angular position in the tube circumferential direction from the distance sensor and the rotation angle sensor, and detect the connection port based on the detection information of the cutting point. A detection device for the position of a connection port of an existing pipe, characterized by determining the position in the pipe axis direction and the angular position in the pipe circumferential direction. 11. The device for detecting the position of a connection port of an existing pipe according to claim 10 , wherein the rotating part is provided with a perforation part that is movable in a radial direction with respect to the rehabilitated pipe.

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