Patent Publication Number: US-2009223335-A1

Title: In-pipe work robot

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to an in-pipe work robot, and more specifically to an in-pipe work robot for performing pipe work inside a first pipe (sewer main pipe) intersecting with a second pipe (lateral pipe). 
     2. Description of the Related Art 
     When a sewer pipe or another existing pipe buried underground has deteriorated, it is known that a pipe lining method is used to line the existing pipe using a pipe lining material in order to restore the existing pipe without digging up the pipe. The pipe lining material is comprised of a flexible tubular resin absorbing material impregnated with an uncured liquid setting resin (commonly a thermosetting resin). The resin absorbing material is made of a non-woven fabric having a pipe shape corresponding to the shape of the existing pipe. A highly airtight plastic film is coated on the external peripheral surface of the resin absorbing material. 
     In the lining work, the lining material is pulled into the existing pipe or everted and inserted into the existing pipe by means of fluid pressure. The inserted lining material is pressed against the internal peripheral surface of the existing pipe, and the liquid setting resin impregnated in the pipe lining material is heated and cured to line the internal surface of the existing pipe. 
     Commonly, a lateral pipe communicates with a sewer pipe or another main pipe. When the main pipe is lined with the pipe lining material, the pipe lining material blocks the opening at the end of the juncture of the lateral pipe. Therefore, an in-pipe work robot provided with a drill and a TV camera is transported into the main pipe and operated remotely from aboveground. The cutter (rotary blade) of the drill is rotatably driven from the main pipe to drill through and remove the portion of the pipe lining material that blocks the end of the lateral pipe (JP-A-2000-15509). 
     However, the cutter of the drill must be positioned in the pipe length direction, the peripheral direction and the vertical direction of the main pipe prior to drilling. This is accomplished while monitoring the main pipe interior with a TV camera. However, since the main pipe interior has poor visibility, being dark, there are cases in which mistakes are made in positioning; i.e., mistakes are made in the drilling positions. 
     As a countermeasure, a method is used in which a hole saw linked to a flexible shaft for transmitting the rotary power of a motor is inserted into the lateral pipe prior to drilling, and a tentative hole small in diameter is formed from the lateral pipe in the portion of the pipe lining material that blocks the opening of the lateral pipe. After the tentative hole is formed, the TV camera is inserted through the lateral pipe, and a hole is drilled from the main pipe while the lateral pipe interior is monitored. 
     However, in the method for forming a tentative hole from the lateral pipe, the hole saw is movably supported by the flexible shaft in the direction orthogonal to the pipe length direction of the lateral pipe. Therefore, it is difficult to position the hole saw in the lateral pipe in the desired drilling position (for example, the center position of the opening of the end of the lateral pipe or the like), and there are cases in which the drilling position deviates from the desired position. 
     There are also cases in which the hole saw slips and moves due to a reaction by rotation in the direction orthogonal to the pipe length direction of the lateral pipe, and the hole saw collides with the internal peripheral surface of the lateral pipe, particularly in cases in which the pipe lining material that blocks the end of the lateral pipe has a hard surface. In this case, problems occur such as the hole saw being damaged, or the pipe lining material being scratched in cases in which the lateral pipe is lined. 
     Another problem of the prior art is that a metal cutter or hole saw is used to cut the pipe lining material and form a hole in the pipe lining material from either the lateral pipe or the main pipe. This causes the peripheral portions of the lateral pipe to be unintentionally scratched. 
     It is therefore an object of the invention to provide an in-pipe work robot capable of reliably cutting a lining material to make an opening at that portion of the lining material which blocks the junction of the first and second pipes. 
     Another object of the present invention is to provide an in-pipe work robot capable of shattering or breaking up obstacles when the lining material is to be drilled through. 
     SUMMARY OF THE INVENTION 
     In the present invention, an in-pipe work robot for performing pipe work inside a first pipe intersecting with a second pipe comprises a cutting nozzle for spraying a pressurized fluid material or pressurized granular material onto an internal wall surface of the first pipe to cut a junction between the first pipe and the second pipe; a movement mechanism for moving the cutting nozzle inside the first pipe along a center axis thereof; a rotary mechanism for rotating the cutting nozzle about a vertical axis; and a roll mechanism for rolling the cutting nozzle within a plane perpendicular to the center axis of the first pipe. The cutting nozzle is moved to a predetermined position and rotated to cut the junction between the first and second pipes by the pressurized fluid material or pressurized granular material sprayed from the cutting nozzle and to thereby form an opening for communicating the first pipe with the second pip. 
     An in-pipe work robot according to the present invention also comprises a cutting nozzle for spraying a pressurized fluid material or pressurized granular material onto an internal wall surface of the first pipe to cut a junction between the first pipe and the second pipe; an XY robot for moving the cutting nozzle inside the first pipe along an x-axis direction corresponding to a center axis of the first pipe and a y-axis direction orthogonal to the x-axis direction; and a control means for controlling the position of the cutting nozzle in the x-axis and y-axis directions. The control means moves the XY robot and the cutting nozzle sequentially to predetermined positions to cut the junction between the first and second pipes by the pressurized fluid material or pressurized granular material sprayed from the cutting nozzle and to thereby form an opening for communicating the first pipe with the second pipe. 
     An in-pipe work robot according to the present invention also comprises a disposal nozzle for spraying a pressurized fluid material or pressurized granular material onto an obstruction to be removed; a movement mechanism for moving the disposal nozzle inside the pipe within a plane perpendicular to a center axis of the pipe; and a control means for controlling the movement of the disposal nozzle. The control means moves the disposal nozzle to a predetermined position to dispose of the obstruction in front of the disposal nozzle by the pressurized fluid material or pressurized granular material sprayed therefrom. 
     In the present invention, an opening for communicating the first pipe with the second pipe is formed by a pressurized fluid material or pressurized granular material sprayed from a cutting nozzle, making it possible to drill a hole without breaking or damaging the periphery of the drilled portion, unlike in a case in which a metal cutter or the like is used for drilling. 
     Also in the present invention, the cutting nozzle can be moved along a pipe center axis or rolled within a plane perpendicular to the pipe center axis, or the cutting nozzle can be attached to an XY robot and moved. This allows the cutting nozzle to be placed in desired positions and holes to be drilled accurately. 
     Further features of the invention, its nature and various advantages will be more apparent from the accompanying drawings and following detailed description of the invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view showing a schematic external view of an in-pipe work robot according to the present invention; 
         FIG. 2  is a front view showing a segment of part of the in-pipe work robot; 
         FIG. 3  is a top view showing the rotary mechanism of the in-pipe work robot; 
         FIG. 4  is a front view showing the in-pipe work robot as being set up in a main pipe; 
         FIG. 5   a  is a top view of a metal ball holder, and  FIG. 5   b  is a side view of the same; 
         FIG. 6  is an illustrative view showing an image of the metal ball holder as viewed from the side facing the lateral pipe; 
         FIG. 7   a  is a top view of an XY robot, and  FIG. 7   b  is a side view of the same; 
         FIG. 8  is a front view of an embodiment of an in-pipe work robot provide with an XY robot; 
         FIG. 9  is an illustrative view showing a system for controlling the position of the cutting nozzle; 
         FIG. 10  is an illustrative view showing how the shape of the cut outline is determined; and 
         FIG. 11  is a front view showing another embodiment of the present invention in which the XY robot is stood upright to shatter obstacles. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The present invention will now be described in detail based on the illustrated embodiments. The embodiments are described with reference to a case in which a sewer pipe or other main pipe is used as the first pipe, and a lateral pipe which branches from the main pipe to aboveground is used as the second pipe. However, the present invention is not limited to these embodiments alone and can be applied to a system for drilling a hole in an arrangement in which the first and second pipes intersect with each other, and an opening that communicates with the second pipe is formed at the intersection. An embodiment will be described in which the first pipe is lined with a pipe lining material, a hole is formed in the lined first pipe to provide an opening. However, the method can also be applied to a pipe that has not been lined. The present invention can also be applied to a case of forming a hole in that lining material portion of a main pipe that blocks the open end of a lateral pipe for both cases in which the lateral pipe is lined prior to lining the main pipe, and the main pipe is lined prior to lining the lateral pipe. 
     An in-pipe work robot  1  includes a carriage  8 , which is provided at the front with wheels  4 ,  5  rotated by a motor  2  via a belt  6  and a pulley  3 , as shown in  FIGS. 1 and 2 . Wheels  4 ′,  5 ′ rotated by a motor  2 ′ via a belt  6 ′ and a pulley  3 ′ are similarly mounted at the rear of the carriage  8 . The carriage  8  is moved in the x-axis direction by driving either one of the motors  2 ,  2 ′ or by synchronously driving both of the motors  2 ,  2 ′. The in-pipe work robot  1  is set up inside a main pipe  60  that extends in x-axis direction, i.e., in the pipe length direction. The x-axis direction is also the direction along which lies a central axis  60   a  of the main pipe  60 , as shown in  FIG. 4 . 
     A tubular roll cylinder  10  that constitutes a roll mechanism is mounted on top of the carriage  8  via bearing plates  11 ,  12  composed of ball bearings. An internal gear  10   a  is formed in the internal peripheral surface of the rear end of the cylinder  10 . The internal gear  10   a  meshes with a gear  13  that is rotated about a motor shaft  15   a  by a motor  15  fixed to an attachment platform  16 . When the motor  15  rotates, the meshing between the gear  13  and the internal gear  10   a  causes the cylinder  10  to roll about its own center axis. The in-pipe work robot  1  is configured so that when the robot is set up inside the main pipe  60 , the roll axis of the cylinder  10  substantially coincides with the center axis  60   a  of the main pipe  60 . 
     In the center at the top of the roll cylinder  10 , a lifting cylinder  22  constituting a lifting mechanism is mounted via a guide ring  21  so as to rise and fall relative to the roll cylinder  10 . The top of the lifting cylinder  22  is open. A rotary ring  23  constituting a rotary mechanism is supported via ball bearings  20  in the top of the lifting cylinder, and an internal gear  23   a  is formed in the internal peripheral surface of the rotary ring  23 , as can be seen from  FIG. 3 . Fixed in the bottom part  22   b  of the lifting cylinder  22  is a motor  28  for rotating a gear  24  that is meshed with the internal gear  23   a  of the rotary ring  23 . Rotation of the motor  28  causes torque to be transmitted via the gear  24  to the rotary ring  23 , and the rotary ring  23  rotates about a center axis  22   a  ( FIG. 4 ) of the lifting cylinder  22 . 
     A cutting nozzle  30  extending in a perpendicular direction (the z-axis direction) is fixed to the rotary ring  23 , and water, sand, or another pressurized fluid material or pressurized granular material is sprayed from the spray port  30   a  of the cutting nozzle  30  onto the internal wall surface of the main pipe  60 , as will be described hereinafter. 
     A columnar support  25  is erected in the center of the bottom part  22   b  of the lifting cylinder  22 , and a cylindrical magnet (permanent magnet or electromagnet)  27  is fixed via a disc  26  in the top of the columnar support  25 . The lifting cylinder  22  is closed at the top by a cover  32  having openings  32   a ,  32   b . In  FIG. 1 , the cover  32  is shown separated from the lifting cylinder  22  in order to depict the internal structure, but when the lifting cylinder  22  is closed by the cover  32 , the disc  26  fixed to the columnar support  25  and the cutting nozzle  30  are inserted respectively through the openings  32   a  and  32   b  of the cover  32 . Therefore, the magnet  27  and the spray port  30   a  of the cutting nozzle  30  can protrude from the surface of the cover  32 , as shown in  FIG. 2 . The cover  32  is mounted to the rotary ring  23  so as to be capable of being rotated by the motor  28  about the center axis  22   a  together with the rotary ring  23  and the cutting nozzle  30  mounted thereon. 
     As shown in  FIG. 4 , a lifting device  40  is provided at the bottom part of the roll cylinder  10  so that it can raise and lower a pantograph  41  via a rod  42  and the lifting cylinder  22  mounted on top of the pantograph  41  can rise and fall. 
     As shown in  FIG. 1 , a camera  47  is mounted at the rear of the carriage  8  via a columnar support  46  fixed to a support base  45 , and the images photographed by the camera  47  can be viewed to observe the piping work inside the main pipe  60 . 
     In the embodiment described above, power supply lines to the motors  2 ,  2 ′,  15 ,  28 , the lifting device  40 , and other components, or lines for supplying fluid material or granular material to the cutting nozzle  30  would complicate the drawings and are therefore omitted. 
     The internal peripheral surface of the main pipe  60  is lined by a conventional method using a pipe lining material  62 , as shown in  FIG. 4 . At this time, since the pipe lining material  62  blocks a main pipe-side opening  61   b  of a lateral pipe  61  that intersects the main pipe  60 , a hole must be drilled through the pipe lining material  62  in this portion. 
     The in-pipe work robot  1  is used to form a hole in this type of pipe lining material  62  and to communicate the main pipe  60  with the lateral pipe  61 . The operation of drilling a hole in the pipe lining material  62  is described in the following. 
     The in-pipe work robot  1  is conveyed into the main pipe  60  and is moved within the main pipe  60  in the x-axis direction along the center axis  60   a  of the main pipe  60  by the driving of the motors  2 ,  2 ′. A lamp (not shown) illuminates the interior of the lateral pipe  61  to make brighter the portion of the pipe lining material  62  that blocks the opening  61   b  of the lateral pipe  61 . The carriage  8  is advanced to this portion, which is observed from aboveground or from within the manhole through the camera  47 . 
       FIGS. 5   a  and  5   b  shows a metal ball holder (metal member)  52  for housing metal balls  52   a ,  52   b ,  52   c . The metal ball holder  52  is inserted in advance into the lateral pipe  61 , and rests by gravity on the pipe lining material  62 . The metal ball holder  52 , being attracted by the magnet  27  mounted on the lifting cylinder  22 , moves on the pipe lining material  62  in the x-axis direction in accordance with the forward or reverse movement of the carriage  8 . In order to ensure attraction by the magnet  27 , the lifting device  40  is driven to raise the lifting cylinder  22  to a height where the magnet  27  will come in contact with the internal side of the pipe lining material  62 . 
     When the motor  15  is driven, the roll cylinder  10  rolls about the center axis  60   a  of the main pipe  60 , and the magnet  27  also rolls about the pipe center axis  60   a  within a plane (the yz plane) perpendicular to the center axis  60   a . The metal ball holder  52  moves on the pipe lining material  62  in the y-axis direction in accordance with the rolling of the magnet  27 . 
     Thus, the carriage  8  is moved forward and backward and the cylinder  10  is rolled in order to move the metal ball holder  52  on the pipe lining material  62  in the xy direction. The movement of the metal ball holder  52  can be observed from aboveground through a camera  50  mounted on a flexible shaft  51 .  FIG. 6  shows an image of the metal ball holder  52  positioned on the pipe lining material  62  in the portion of the opening  61   b  of the lateral pipe  61 . The carriage  8  is moved forward and backward and the roll cylinder  10  is rolled until the metal ball holder  52  moves to the substantial center of the opening  61   b.    
     When it has been visually confirmed that the metal ball holder  52  has moved to the substantially center position of the lateral pipe opening  61   b  as shown in  FIG. 6 , the movement of the carriage  8  and the rolling of the roll cylinder  10  are stopped. In this state, the center axis  22   a  of the lifting cylinder  22  intersects with the center axis  61   a  of the lateral pipe  61  in the center of the lateral pipe opening  61   b , as shown in  FIG. 4 . 
     When the center of the opening to be formed by the cutting nozzle  30  is positioned so as to coincide with the pipe center axis  61   a  of the lateral pipe  61 , water, sand, or another such pressurized fluid material or pressurized granular material is supplied to the cutting nozzle  30 , and the motor  28  is actuated to rotate the rotary ring  23  as well as the cutting nozzle  30  mounted thereon at a peripheral velocity of, e.g., 4 mm/sec to 10 mm/sec. The fluid material or granular material sprayed from the spray port of the cutting nozzle  30  is blown onto the internal peripheral surface of the pipe lining material  62  (6.5 mm to 10 mm in thickness) of the main pipe  60  at a jet pressure of about 150 to 250 MPa and a jet diameter of 0.5 mm to 1.5 mm. This allows the pipe lining material  62  to be drilled through. When the rotary ring  23  makes one revolution, a circular hole is drilled into the pipe lining material  62  that has blocked the lateral pipe opening  61   b , thus forming an opening which is substantially equivalent to the opening  61   b  of the lateral pipe  61 . 
     The rotational speed (peripheral velocity) of the cutting nozzle is determined according to at least the jet pressure of the fluid material (or granular material), and the thickness and material of the pipe lining material to be drilled so that a circular hole can be drilled when the cutting nozzle makes one revolution. 
     In a case in which a granular material is sprayed, it is possible to use as the granular material garnet, a silicon-based material (silicon dioxide), or other sand material (grain size: 0.1 mm to 0.5 mm). 
     In the embodiment described above, the shape of the cut pipe lining material  62  is circular because the cutting nozzle  30  rotates about the center axis  22   a . However, the shape of the open end  61   b  of the lateral pipe  61  could be elliptical depending on the manner in which the lateral pipe  61  is mounted to the main pipe  60 , making it impossible to guarantee that a hole matching the shape of the open end  61   b  will be drilled. 
     In view of this, an embodiment is described in which an XY robot (XY table) is used to drill a hole having an arbitrary shape. 
       FIGS. 7   a  and  7   b  show the details of the configuration of an XY robot  70  used to drill a hole. Y-axis rails  72 ,  73  disposed in parallel are fixed to a base  71  of the XY robot  70 , and an X-axis rail  74  is disposed so as to span the Y-axis rails  72 ,  73 . One end  74   a  of the X-axis rail  74  is fixed to a belt  78  wrapped around a driven pulley  77  and a pulley  76  driven by a Y-axis motor  75 . When the Y-axis motor  75  is driven, the X-axis rail  74  moves back and forth in the y-axis direction along the Y-axis rails  72 ,  73 . 
     The X-axis rail  74  carries an X-axis head  80 , an X-axis motor  81 , a driven pulley  83  and a pulley  82  driven by the X-axis motor  81 . One end  80   a  of the X-axis head  80  is fixed to a belt  84  wrapped around the pulleys  82 ,  83 . When the X-axis motor  81  is driven, the X-axis head  80  is guided by the X-axis rail  74  to move back and forth in the x-axis direction. 
     An X-axis rod  85  is disposed on the X-axis rail  74  with one end fixed to the X-axis head  80 . A magnet  27  and cutting nozzle  30  identical to those in  FIG. 1  are mounted via an attachment platform  86  to the other end of the X-axis rod  85 . When the X-axis motor  81  is driven, the X-axis head  80  moves in the x-axis direction, and the magnet  27  and cutting nozzle  30  therefore also move in the x-axis direction in accordance with this movement. When the Y-axis motor  75  is driven, the X-axis head  80  moves in the y-axis direction, and the magnet  27  and cutting nozzle  30  therefore also move in the y-axis direction. Thus, by actuating the X-axis motor  81  and the Y-axis motor  75 , the magnet  27  and cutting nozzle  30  can be moved in the xy directions within a range that corresponds to the movement range of the X-axis head  80  in the xy directions. 
     The reason the cutting nozzle  30  is placed a predetermined distance apart from the Y-axis rail  72  on the XY robot  70  is to prevent the fluid material or granular material, cut scrap, or the like from falling onto the X-axis rail  74 , the Y-axis rails  72 ,  73 , the X-axis motor  81 , the Y-axis motor  75 , and other XY drive mechanisms of the XY robot, and the drive mechanisms thereof from being damaged, as will be described hereinafter. 
     The XY robot  70  is mounted on the in-pipe work robot and moved inside the main pipe  60 , as shown in  FIG. 8 . The XY robot  70  is installed on a mounting platform  49  so as to be capable of being raised and lowered in a perpendicular direction (z-axis direction) via the pantograph  41  by the lifting device  40  fixed to the carriage  8  via an attachment platform  48 . The XY robot  70  is mounted so that the X-axis rail  74  is parallel to the x-axis direction, which is itself parallel to the center axis  60   a  of the main pipe  60 ; the Y-axis rails  72 ,  73  are parallel to the y-axis direction, which is itself perpendicular to the x- and z-axes; and the plane defined by the X-axis rail (x-axis) and Y-axis rails (y-axis) is a horizontal plane. The attachment platform  48  is rotated about the y-axis  48   a  or the x-axis  48   b  so as to keep the XY robot  70  horizontal. Alternatively, adjusters are provided at the four corners of the mounting platform  49  and the base  71 , and the levelness is adjusted to keep the plane defined by the X-axis rail and Y-axis rails horizontal. 
     Next, the magnet  27  mounted on the XY robot  70  is moved in the x-axis and y-axis directions in the main pipe  60 , and the movement of the metal ball holder  52  attracted by the magnet  27  is observed through the camera  50 . 
     As shown in  FIG. 9 , a controller (control means)  90  drives the X-axis motor  81  and Y-axis motor  75  to move the X-axis head  80 , the X-axis rod  85  and the magnet  27  fixed thereto in the x-axis and y-axis directions. Rotary encoders  81   a ,  75   a  are attached respectively to the X-axis motor  81  and Y-axis motor  75  to determine the x, y coordinates of the current position of the magnet  27 , whose information is inputted from the rotary encoders  81   a ,  75   a  to the controller  90 . 
     The magnet  27  is moved to a position where the center of the magnet  27  substantially coincides with the center axis  61   a  of the lateral pipe  61 , and this position is used as an origin (x 0 , y 0 ). The magnet  27  is moved in the r 1  direction, for example, as shown in  FIG. 10 , and the movement of the metal ball holder  52 , which moves in the r 1  direction in accordance with the movement of the magnet  27 , is observed through the camera  50 . The metal ball holder  52  stops when the metal ball holder  52  reaches the lateral wall  61   c  of the lateral pipe  61 . Therefore, driving of the X-axis motor  81  and Y-axis motor  75  stops when the ball holder  52  is observed to have stopped, and the position of the magnet  27  is calculated based on the position information from the rotary encoders  81   a ,  75   a . The coordinates (x 1 , y 1 ) of the positions where the metal ball holder  52  comes in contact with the lateral pipe lateral wall  61   c  can be calculated from the position of the magnet and the diameter d of the metal ball holder  52 . 
     Thus, the magnet  27  is moved in various radial directions away from the pipe center axis  61   a . The positional coordinates of the outline of the opening  61   b  of the lateral pipe  61  can be determined if the coordinates (xn, yn) (n=1, 2, 3, . . . ) of the positions is given where the metal ball holder  52  comes in contact with the lateral wall  61   c . Since the outline of the opening  61   b  is generally elliptical, the outline coordinates can be made more precise through elliptical interpolation when the contact positions are few in number. 
     The positional coordinates of the outline of the opening  61   b  of the lateral pipe  61  determined in this manner are stored in a memory  91 . When the hole is actually drilled, the carriage  8  is moved in advance so that the cutting nozzle  30  is positioned substantially in the center of the opening  61   b  of the lateral pipe  61  while the X-axis head  80  is positioned in the substantial center of the XY robot  70 , as shown in  FIG. 8 . The outline position coordinates of the opening  61   b  are then read from the memory  91 , the X-axis motor  81  and Y-axis motor  75  are driven to move the cutting nozzle  30  to the read position, and the pressurized fluid material or pressurized granular material is sprayed from the cutting nozzle to cut the pipe lining material  62 . 
     When the cutting nozzle  30  is moved sequentially to the coordinate positions stored in the memory  91  while the pressurized fluid material or pressurized granular material is sprayed from the cutting nozzle. The cutting nozzle  30  is moved along a pathway corresponding to the outline of the lateral pipe opening  61   b . Given that the jet parameters of the cutting nozzle  30  (movement speed, jet pressure, jet diameter, and other parameters) are set to those as mentioned above, the pipe lining material  62  that blocks the lateral pipe opening  61   b  can be cut to form a hole corresponding to the opening  61   b  when the cutting nozzle  30  makes a full circle. 
     It is possible to prevent the fluid material or granular material, the cut scrap, or the like from falling onto the XY drive mechanism and damaging the drive mechanism, because the cutting nozzle  30  is mounted away from the drive mechanism of the XY robot  70 , as described above. 
     With the configuration of the embodiment using the XY robot, it is possible to form not only holes having an elliptical shape such as is described above, but also holes having a circular, rectangular, or any arbitrary shape. 
       FIG. 11  shows another embodiment in which an XY robot  100  having the same configuration as the XY robot  70  described above is stood upright and mounted at the front of the carriage  8 . The XY robot  100  has an X-axis rail  101  and Y-axis rails  102 ,  103 , and an X-axis head  104  is mounted on the X-axis rail  101 . A disposal nozzle  105  whose direction of spraying is pointed forward (in the direction running parallel to the center axis  60   a  of the main pipe  60 ) is attached to the X-axis head  104 . 
     The disposal nozzle  105  sprays a pressurized fluid material or a pressurized granular material in the same manner as the cutting nozzle  30 , and the disposal nozzle  105  is used to shatter or break up rock, wood, or other such obstacles (obstructions) in front of the in-pipe work robot when it moves forward. 
     When an obstacle is observed through a camera (not shown) set up in front, the disposal nozzle  105  is moved within a plane (yz plane) perpendicular to the pipe center axis  60   a  to a position where the disposal nozzle  105  faces the obstacle. The pressurized fluid material or pressurized granular material is then sprayed from the disposal nozzle  105  to shatter or break up the obstacle. 
     With this configuration, in-pipe obstacles can be reliably shattered and in-pipe work can be carried out efficiently. 
     A switching valve  110  is provided for supplying the pressurized fluid material or pressurized granular material between the cutting nozzle  30  and the disposal nozzle  105 . The pressurized fluid material or pressurized granular material is supplied to the cutting nozzle  30  when the pipe lining material  62  is to be cut, and the pressurized fluid material or pressurized granular material is supplied to the disposal nozzle  105  when the obstacle in front is to be disposed of. 
     In the embodiments as described above, the metal ball holder  52  and/or the metal balls  52   a ,  52   b ,  52   c  housed therein is made of a metal such as iron, or steel and the like that can be attracted by the magnet  27 , but the holder  27  and balls  52   a ,  52   b ,  52   c  can also be made of a magnetic substance such as iron oxide, chromium oxide, cobalt, ferrite and the like. The embodiments as described above can also be so modified that the holder  52  and the balls  52   a ,  52   b ,  52   c  therein is mounted on the columnar support  25  or the X-axis rod  85  of the XY robot  70 , and the magnet  27  is moved on the pipe lining material  62  at the opening  61   b  of the lateral pipe  61 .