JP2006328729A - Underground jacking device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To remove an excavating head into a start position for replacement in a short time without removing a buried pipe when replacing the excavating head halfway in laying the buried pipe. <P>SOLUTION: This underground jacking device 1 comprises a jacking machine 20; a leading body 2 arranged at the rear part; an inner cylindrical body 3 inserted in the leading body 2; a screw 4 arranged in the inner cylindrical body 3; and the excavating head 5 fixed to the tip of the screw 4. The excavating head 5 has a head body 8 having an outer diameter smaller than the inner diameter of the leading body 2 and larger than the outer diameter of the inner cylindrical body 3, and a plurality of turning plates 10 or the like formed with excavating bits 15 fixed thereto, and mounted to the head body 8. The plurality of turning plates are arranged to move so that the respective tips project outward from the outer periphery of the leading body 2 due to excavating resistance when the head body 8 is normally rotated and to move inward from the outer periphery of the head body 8 due to excavating resistance when the head body 8 is reversely rotated. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an underground propulsion apparatus used when an underground pipe is continuously propelled while excavating the underground and the underground pipe is laid in the ground.

  Conventionally, for example, a ground where a large number of buried pipes are sequentially propelled from the start position toward a reach position such as a start shaft from a start position such as a start shaft, and the buried pipes are installed in the ground from the start position to the reach position. An intermediate propulsion method is known, and an underground propulsion device is used as a device for performing such a propulsion method.

This underground propulsion device is used in combination with a propulsion device disposed at a start position, and this propulsion device rotates a pressing mechanism that presses the underground propulsion device in the direction of the arrival position and a screw described later. A rotation mechanism is provided. The underground propulsion apparatus includes a cylindrical tip conductor having a continuous buried pipe at the rear, an inner cylinder inserted into the tip conductor, and a helical structure disposed on the outer periphery of the inner cylinder. And a rotatable screw, and an excavation head fixed to the front end of the screw and having a plurality of excavation bits fixed to the front (see Patent Document 1). In such a conventional underground propulsion device, the screw and the excavation head are rotationally driven by the propulsion device, and the buried pipe following the leading conductor is pressed in the direction of the arrival position, so that the natural ground is excavated gradually. The leading conductor and the buried pipe are propelled, and the earth and sand excavated by the excavation head passes through the inner cylinder by the rotation of the screw and is conveyed to the start position. When the underground propulsion device propels the underground, the buried pipe is added from the rear according to the propulsion distance, and the screw and the inner cylinder are also added.
JP 2001-214690 A

  By the way, in the ground where the buried pipe should be laid while excavating, there are cases where there are a large number of gravels and, in some cases, obstacles such as buried pipes laid in the past. In the case where such an obstacle exists, it is not possible to lay the initially planned buried pipe unless the excavation head originally arranged is replaced. However, in the conventional underground propulsion device described above, in order to replace the excavation head, all of the pipes including the already laid underground pipes must be removed to the starting position, which is very troublesome and Long working time is required. In particular, when steel pipes are used as the buried pipes and propelled while welding the individual steel pipes, the drawn steel pipes must be cut, which is a very harsh operation. Even when these steel pipes are not used or when fasteners such as bolts and nuts are used without welding, there is a risk of causing ground subsidence due to the collapse of the cavity formed after drawing. For this reason, it is necessary to fill the cavity with a filler or the like, which not only causes a significant delay in the construction period but also requires enormous costs.

  Therefore, the present invention has been proposed in order to solve the problems of the conventional underground propulsion device described above, and it is a case where the necessity to replace the excavation head occurs during the laying of the buried pipe. The purpose of this project is to propose a new underground propulsion device that eliminates the need to remove the buried pipe, and allows the excavation head to be removed and replaced within a very short time. is there.

  The present invention has been proposed in order to achieve the above-described object, and the first invention (the invention described in claim 1) is pressed in the direction of the arrival position by the propulsion device disposed at the start position. A cylindrical tip conductor with a buried buried tube at the rear, an inner cylinder inserted into the tip conductor, a screw that is arranged in the inner cylinder and has a helical structure on the outer periphery, and a rotatable screw, An underground propulsion device having a drilling head fixed to the tip of the screw and having a plurality of drilling bits fixed to the front, wherein the drilling head has an outer diameter smaller than the inner diameter of the leading conductor. The head main body has an outer diameter larger than the outer diameter of the inner cylinder and is formed in a substantially disk shape. The head main body is pivotally supported on the front of the head main body, and a drilling bit is fixed on the front. A plurality of rotating plates The plurality of rotating plates move so that the excavation bit receives the resistance of the soil in the ground when the head main body rotates in the forward direction and the tips protrude outward from the outer periphery of the leading conductor, and during the reverse rotation. The excavation bit receives the resistance of the soil in the ground, and is arranged so as to move inward from the outer periphery of the head body.

  In the first aspect of the invention, when the excavation head fixed to the tip of the screw is driven to rotate forward together with the screw, a plurality of rotation plates fixed to the front surface of the head main body constituting the excavation head are Due to the resistance between the excavation bit fixed to the front surface and the soil in the ground, the excavator bit moves outside the outer periphery of the leading conductor. When the excavation head rotates in the forward direction, the natural ground is excavated, and the earth and sand generated by the excavation flows into the inner cylinder and is transferred to the start position by the rotation of the screw. Along with such operations, the leading conductor, the buried pipe, the inner cylinder, the screw, and the excavation head that follow the leading conductor are pressed from the starting position, and as a result, the whole gradually propels through the ground. In addition, since the tip of each rotary plate constituting the excavation head is located outside the outer periphery of the leading conductor, the friction resistance between the leading conductor and the outer peripheral surface of the buried pipe following this and the natural ground is reduced. Reduced. During such propulsion, when the excavation head hits an obstacle such as gravel and it becomes necessary to replace the excavation head, the screw and the excavation head are reversely rotated. Due to the reverse rotation of the excavating head, each rotating plate that has been projected outward from the outer periphery of the leading conductor until now is more than the outer periphery of the head body due to the resistance between the excavating bit fixed to the front surface of the rotating plate and earth and sand. Also move inward. When each rotating plate moves in this manner, the outer diameter of the head main body is smaller than the inner diameter of the leading conductor, so that the inner cylindrical body, the screw, and the excavation head are left in the state where the advanced leading conductor and the buried pipe are left as they are. Can be pulled out to the starting position, and the excavation head can be replaced.

  The excavation head may be formed in advance with a circular through hole through which a guide pipe propelled and installed in the ground is inserted, or an opening into which excavated earth and sand flows is formed. It may be a thing. Further, at least two or more rotating plates constituting this excavation head need to be provided, each of which is rotatably disposed on the front surface of the head body, and the excavation bit needs to be fixed on the front surface. is there. The rotation range of these rotation plates is a position where the tip end is located outside the outer periphery of the leading conductor and is located inside the outer periphery of the head body, and the rotation center of the rotation plate is The position is not particularly limited. However, these rotating plates receive the resistance of the soil in the ground when the head main body rotates in the forward direction and move so that their tips protrude outward from the outer periphery of the leading conductor, respectively, It is necessary to be arranged so as to move inward from the outer periphery of the head body under the resistance of the earth. For example, the position of the excavation bit needs to be located in the positive rotation direction from the line connecting the arbitrary rotation center and the center of the head body on the outer peripheral side of the head body, and The angle between the line connecting the rotation center and the excavation bit (when moving inward from the outer periphery) and the line connecting the rotation center and the center of the head body may be 45 degrees or more and less than 170 degrees. desirable. When the angle between the line connecting the rotation center and the excavation bit and the line connecting the rotation center and the center of the head main body is less than 45 degrees, when the excavation head rotates forward, The tip may not protrude outside the outer circumference of the leading conductor due to the resistance of the soil inside, and when the angle is 170 degrees or more, the distance from the rotation center to the excavation bit is short. Therefore, there is a possibility that excavation beyond the outer periphery of the leading conductor cannot be performed. Therefore, the angle between the line connecting the rotation center and the excavation bit and the line connecting the rotation center and the center of the head body is more preferably in the range of 50 degrees to 90 degrees.

  Further, according to a second invention (invention of claim 2), in the first invention, the rotating plate moved when the head main body rotates in reverse is in contact with the front surface of the head main body and moves further. It is characterized in that a restricting portion for restricting the operation is formed.

  In the second aspect of the invention, when the head main body rotates in the reverse direction, the excavation bit receives the resistance of the soil in the ground and moves to the inside of the outer periphery of the head main body. If the angle between the connected line and the line connecting the center of rotation and the center of the head body moves to a position narrower than 45 degrees, when the excavation head is replaced and rotated forward, There is a possibility that the tip of the rotating plate does not rotate so as to open to the outside of the head main body due to resistance to the earth. According to the second invention, such inconvenience can be solved.

  The restricting portion only needs to restrict at least the rotation plates that have moved during the reverse rotation of the head main body and restrict further movement.For example, a convex portion is formed on the front surface of the head main body, The convex portion may be configured to contact the rotating plate, or a thin portion corresponding to the outer shape of the rotating plate is formed on the front surface of the head body, and the thin portion and the normal thickness are formed. Alternatively, the rotating plate may be in contact with an upright surface that forms the boundary of the part.

  A third invention (invention according to claim 3) is the invention according to any one of the first and second inventions, wherein a guide tube that is propelled and installed in advance in the ground in the center of the head body. A circular through-hole to be inserted is formed, and a cylindrical portion having the same axis as the through-hole and through which the guide tube is inserted is formed at the center of the screw. It is a feature.

  In the underground propulsion apparatus according to the third aspect of the invention, the guide pipe is propelled in advance from the starting position to the arrival position, and can be applied to a type of underground propulsion apparatus that propels while being guided by the guide pipe. It is.

  According to a fourth invention (invention of claim 4), in the invention of any one of the first, second and third inventions, one engaging portion is formed at the tip of the leading conductor. The front conductor side ring is fixed, and the other end of the inner cylindrical body is engaged with the other engagement portion to engage with the one engagement portion, and the front conductor side ring cooperates with the front conductor side ring. An inner cylinder-side ring that closes the space between the inner cylinder and the inner cylinder is fixed.

  According to a fifth invention (invention according to claim 5), in the fourth invention, the outer peripheral surface of the excavation head is formed with one reduced diameter surface gradually reduced in diameter toward the back side. In addition, the inner peripheral surface of the inner cylinder side ring is formed with the other reduced diameter surface that is gradually reduced in diameter corresponding to one reduced diameter surface formed in the excavation head. It is what.

  According to the first invention (the invention described in claim 1), even when it becomes necessary to replace the excavation head during the laying of the buried pipe, there is no need to remove the laid buried pipe. The excavation head can be removed and replaced to the starting position very easily and within a short time. That is, the excavation head constituting the underground propulsion apparatus has a head body that has an outer diameter smaller than the inner diameter of the leading conductor and an outer diameter larger than the outer diameter of the inner cylinder, and is formed in a substantially disk shape. And a plurality of rotating plates that are pivotally supported on the front surface of the head main body and have excavation bits fixed to the front surface. The plurality of rotating plates are connected to the head main body. During forward rotation, it receives the resistance of underground soil and moves so that its tip protrudes outside the outer periphery of the leading conductor. During reverse rotation, it receives the resistance of underground soil and receives the outer periphery of the head body. Since the excavation bit fixed to each rotating plate can excavate the natural ground with a diameter larger than the outer diameter of the leading conductor, the excavation head is reversed. By rotating, the above By moving the rotating plate to the inside of the outer periphery of the head body, the inner cylinder, the screw, and the excavation head can be pulled out to the start position while leaving the leading conductor and the buried pipe laid. In turn, the drilling head can be replaced.

  In the second invention (the invention described in claim 2), the front surface of the head main body is provided with a restricting portion for restricting movement of the rotating plates that are moved when the head main body is rotated in reverse. Because it is formed, when the excavation head is rotated forward, it is effective that the rotating plate receives the resistance of the excavation bit and the soil in the ground and the tip does not protrude outward from the outer periphery of the leading conductor. Can be prevented.

  In the third invention (the invention described in claim 3), a circular through-hole into which a guide tube propelled and installed in the ground is previously inserted is formed in the center of the head body. In the center of the screw, since a cylindrical portion having the same axis as the through hole is formed and the guide tube is inserted, the guide tube is driven in advance from the starting position to the reaching position, While being guided by the guide pipe, the buried pipe can be laid straight and accurately.

  In the fourth invention (the invention described in claim 4), when the inner cylinder is pressed in the direction of the arrival position by the propulsion device arranged at the start position, the one engagement portion formed on the leading conductor side ring and By engaging with the other engaging portion formed on the inner cylinder side ring, the leading conductor can also be propelled integrally with the inner cylinder, and this inner cylinder side ring is the leading conductor side ring. Since the gap between the tip conductor and the inner cylinder is closed together, there is no risk that the earth and sand excavated by the excavation head enters between the tip conductor and the inner cylinder.

  In the fifth invention (the invention described in claim 4), the inner peripheral surface of the inner cylinder side ring is gradually reduced in diameter corresponding to one of the reduced diameter surfaces formed in the excavation head. Since the reduced diameter surface is formed, first, when the screw and the excavation head are moved in the start position direction, the one reduced diameter surface and the other reduced diameter surface come into contact with each other, and then the screw and the excavation head By moving the inner cylinder and the inner cylinder in the direction of the starting position, it is possible to suppress the risk of earth and sand flowing into the remaining leading conductor.

  Hereinafter, an underground propulsion apparatus according to the best mode for carrying out the present invention will be described in detail in the order of steps with reference to the drawings. The underground propulsion device according to this embodiment applies the present invention to an underground propulsion device that propels the ground (in the second step) while being guided by a guide pipe laid in advance (in the first step). It is a thing. Therefore, in the following, an embodiment of the underground propulsion apparatus will be described in detail, and then an underground propulsion method using the underground propulsion apparatus will be briefly described.

  As shown in FIG. 1, the underground propulsion device 1 includes a leading conductor 2, an inner cylinder 3, a screw 4, and an excavation head 5. The leading conductor 2 is a tubular body made of steel, and a leading conductor side ring 6 is fixed to the tip. The leading conductor 2 is basically the same as the buried pipe laid in the ground following the leading conductor 2 except for the leading conductor side ring 6. The front conductor side ring 6 is formed with a ring-shaped recess 6a into which the tip of the front conductor 2 is inserted on the back surface, and the back surface of the portion located on the inner peripheral side is one engagement constituting the present invention. Part 6b. The rear end of the leading conductor 2 is fixed while the buried pipe P having an outer diameter substantially equal to the outer diameter of the leading conductor 2 is sequentially added. In addition, two O-rings (reference numerals are omitted) are arranged on the inner peripheral surface of the leading conductor side ring 6 to achieve sealing performance with an outer peripheral surface of an inner cylinder side ring 7 described later. The inner cylinder 3 is a cylindrical body having an outer diameter smaller than the inner diameter of the leading conductor 2 (and the embedded pipe P), and an inner cylinder-side ring 7 is provided on the outer periphery of the tip. It is fixed. The inner cylinder side ring 7 is engaged (abutted) when the inner cylinder body 3 is moved from the rear side to the front side with respect to one engaging portion 6b formed on the leading conductor side ring 6. The engaging portion 7a is formed in a ring shape. Further, the outer diameter on the front side of the position where the other engagement portion 7a is formed is slightly smaller than the inner diameter of the leading conductor side ring 6, and the tip of the inner cylinder 3 is formed at the tip. A ring-shaped protrusion 7b that protrudes forward from the tip is formed. And the inner peripheral surface of this ring-shaped protrusion part 7b is made into the other diameter reducing surface 7c gradually diameter-reduced from the front end side to the base end side. The inner cylinder 3 having the inner cylinder side ring 7 fixed to the tip thereof has flange portions 3a and 3b formed on the outer periphery of the front end and the outer periphery of the rear end, respectively, and is formed on the outer periphery of the rear end of the specific inner cylinder 3. The flange portion 3a and the flange portion 3a formed on the outer periphery of the front end of the other inner cylinder body 3 following the specific inner cylinder body 3 are mutually connected via bolts and nuts (both of which are omitted from the reference numerals). By fixing (according to the propulsion of the underground propulsion device 1), it is added in order.

  A screw 4 is inserted into the inner cylindrical body 3. The screw 4 includes a cylindrical portion 4a formed into a cylindrical shape and a spiral blade portion 4b formed on the outer periphery of the cylindrical portion 4a. The cylindrical portion 4a has an inner diameter that is larger than the outer diameter of the tip conduit described later. In addition, this screw 4 is also gradually added with the propulsion of the underground propulsion device 1 in the same manner as the inner cylinder 3.

  An excavation head 5 is fixed to the tip of the screw 4. As shown in FIG. 2, the excavation head 5 includes a head body 8 whose overall shape is formed in a substantially disc shape, and first to third moving plates that are pivotally supported by the head body 8. 9, 10, and 11. As shown in FIG. 1, the head main body 8 has an outer diameter smaller than the inner diameter of the leading conductor 2 and the inner diameter of the leading conductor side ring 6, and the outer peripheral surface of the head main body 8 has the same outer surface. The same-diameter surface 8 a having a diameter and a (one) reduced-diameter surface 8 b formed at the rear of the same-diameter surface 8 a are formed on the inner cylinder side ring 7. It corresponds to the other reduced diameter surface 7c formed. That is, as will be described later, the one diameter-reducing surface 8b and the other diameter-reducing surface 7c have the same diameter-reducing rate so as to be in close contact with each other. Further, as shown in FIGS. 1 and 2, the head main body 8 is formed with a through hole 8c (through which a pre-laid tip conduit is inserted) at the center, and the through hole 8c and the screw 4 are connected to each other. It is set as the same axial center as the cylindrical part 4a to comprise. The first to third thin portions 8d, 8e, and 8f are formed on the front surface of the head main body 8 formed in the above-described shape at equal intervals with respect to the rotation direction of the head main body 8. The first moving plate 9 is pivotally supported by a first support shaft 12 on one thin-walled portion 8d, and the second moving plate 10 is mounted on a second thin-walled portion 8e. The third moving plate 11 is pivotally supported by the third support shaft 14 on the third thin portion 8f. In FIG. 2, the outermost portion indicated by the alternate long and short dash line is the outer diameter of the leading conductor 2. The first to third thin portions 8d, 8e, 8f are formed on the outer peripheral surface side of the head body 8, and the first to third thin portions 8d, 8e, 8f The shape is substantially the same as the outer shape of the first to third moving plates 9, 10, 11. In addition, the step part (a code | symbol is abbreviate | omitted) between the said 1st thru | or 3rd thin part 8d, 8e, 8f and the front surface of the head main body 8 is a control part which comprises this invention.

  The shapes of the first to third thin-walled portions 8d, 8e, and 8f are such that the portion that is widest from the outer periphery of the head main body 8 toward the center of the head main body 8 in the normal rotation direction (counterclockwise in FIG. 2). The width from the outer periphery of the head body 8 is gradually narrowed toward the direction). In addition, inclined surface portions 8h, 8i, and 8j are formed at the tips of the first to third thin-walled portions 8d, 8e, and 8f (in the positive rotation direction of the excavation head 5), respectively. These inclined surface portions 8h, 8i, and 8j are substantially defined by the outer periphery of the head main body 8, the boundary lines of the first to third thin-walled portions 8d, 8e, and 8f, and the boundary lines of the front surface of the head main body 8, respectively. From the apex formed by the boundary line between the outer periphery of the head body 8 and the front surface of the head body 8 to the boundary lines of the first to third thin portions 8d, 8e, and 8f. In this range, the head body 8 is inclined so that the thickness of the head body 8 is gradually reduced. And the 1st thru | or 3rd support shaft 12,13,14 which pivotally supports the said 1st thru | or 3rd moving plates 9,10,11 is the said 1st thru | or 3rd thin part 8d, 8e, 8f. It is fixed to the widest part.

  A large number of excavation bits 15 are fixed to the front surface of the excavation head 5 as shown in FIG. Specifically, the excavation bit 15 is in front of the head main body 8, two between the first moving plate 9 and the second moving plate 10, and the second moving plate 10 and the second moving plate 10. Three are fixed between the third moving plate 11 and four between the third moving plate 11 and the first moving plate 9. Two each of the first to third moving plates 9, 10, 11 are arranged in the middle part on the front end side. And these excavation bits 15 incline so that it may approach gradually the normal rotation direction of the excavation head 5 from the base end side to the front end side.

  Therefore, when the excavation head 5 rotates forward and is pushed forward in the ground, the earth and sand are moved from the inclined surface portions 8h, 8i, 8j to the front of the first to third moving plates 12, 13, 14. To. Then, frictional resistance between the earth and sand and each of the excavation bits 15 is generated, and the first to third moving plates 12, 13, and 14 are slightly moved clockwise from the state shown in FIG. 3 as shown in FIG. The tip ends of the first to third moving plates 12, 13, 14 protrude outward from the outer periphery of the head body 8. In such a state, the natural ground is excavated by the respective excavation bits 15 in substantially the same range as the outer diameter of the leading conductor 2. Further, by stopping and rotating the excavation head 5 that is normally rotated, the first to third movable plates 9, 10, and 11 whose front ends have protruded to the outside are connected to the excavation bits 15. Each of the support shafts 12, 13, 14 is centered from the state shown in FIG. 2 due to resistance with the earth or sand or resistance between the earth and sand existing on the outer periphery of the excavation head 5 and the first to third moving plates 9, 10, 11. 2, the first to third thin portions 8d, 8e, 8f and the front surface of the head body 8 are further stepped by the step portions (reference numerals are omitted). The third moving plates 9, 10, and 11 do not rotate and are in the state shown in FIG. That is, the first to third moving plates 9, 10, and 11 whose leading ends have protruded to the outside of the head main body 8 are accommodated in the first to third thin portions 8d, 8e, and 8f, and the head main body 8 It will be in the state which does not protrude outside from the outer periphery. Then, after the screw 4 is moved forward (starting position direction) after the state shown in FIG. 3, one of the reduced diameter surfaces 8 b formed on the excavation head 5 is brought into contact with the inner cylinder side ring 7. When it joins with the other diameter-reduced surface 7c formed and the screw 4 is further moved forward, the screw 4 and the inner cylindrical body 3 are integrally moved (pulled out).

  Hereinafter, a method of excavating the underground and laying the buried pipe P while using the above-described underground propulsion device 1 will be described. In this buried pipe laying method, a start shaft which is a start position and a reach shaft which is a reach position separated from the start shaft are formed, and the propulsion device 20 is installed in the start shaft. The propulsion device 20 is arranged on two left and right rails 21 and 22 as shown in FIG. 4, FIG. 5, or FIG. 6. These two rails 21 and 22 are arranged from the starting vertical shaft toward the final vertical shaft, and guide the propulsion device 20. Further, left and right contact members 23 and 24 (see FIG. 6) are fixed to the upper surfaces of the rear ends of the two rails 21 and 22, respectively. The starter 20 includes a slide member 25 that is slidably supported in the length direction of the two rails 21 and 22, and a left hydraulic cylinder 26 and a right hydraulic cylinder 27 that are fixed to the slide member 25. It has. A cylinder rod (not shown) of the left hydraulic cylinder 26 is fixed to the left contact member 23, and a cylinder rod 27 a of the right hydraulic cylinder 27 is fixed to the right contact member 24. Therefore, the propulsion device 20 moves forward and backward by driving the left hydraulic cylinder 26 and the right hydraulic cylinder 27. In addition, an inner rotating disk 30 formed in a disk shape is disposed at the center of the slide member 25 so as to be freely rotatable in the forward and backward directions. The inner turntable 30 is a part used when rotating the leading conduit described later and when rotating the screw 4. A through hole 30a is formed at the center of the inner turntable 30. A ring-shaped inner positioning portion 30b having an inner diameter of the same diameter as the through hole 30a protrudes from the front surface of the rotating plate 30 (see FIG. 5). Further, an outer positioning portion 25a having a diameter larger than the diameter of the inner positioning portion 30b protrudes from the front surface of the slide member 25, and an outer turntable 29 is provided inside the outer positioning portion 25a. It is arranged so that it can rotate freely. The outer rotating disk 29 is formed in a donut shape, and is a member used when rotating the inner cylinder 3 described later. The inner positioning part 30b is a part for positioning a pipe inner pipe to be described later, and the outer positioning part 25a is a part for positioning the inner cylindrical body 3. Further, as shown in FIG. 6, six drive motors 31 for rotating the rotating board 30 forward and backward are arranged on the back surface of the slide member 25.

In this buried pipe laying method, first, as shown in FIG. 7, the propulsion unit 20 is installed in the start shaft H ₁ , and the proximal end of the leading conduit 40 is attached to the rotating plate 30. by repeating the advancing and retracting the slide member 25 of the propulsion unit 20, press-fitting the lead pipe 40 to the arrival pit H ₂ directions. The tip conduit 40 is composed of a tip conduit outer tube 41 made of a steel pipe and a tip conduit inner tube 42 inserted into the tip conduit outer tube 41. The distal end of the inner pipe 42 is positioned by an inner positioning portion 30b that constitutes the propulsion unit 20, and an excavation bit 43 is fixed to the distal end. Note that a plurality (three) of high-intensity light-emitting diodes (not shown) are fixed inside the distal end of the inner pipe 42. Accordingly, by driving the left hydraulic cylinder 26 and the right hydraulic cylinder 27 constituting the propulsion device 20, the slide member 25 is advanced, and the six drive motors 31 are driven, whereby the excavation bit 43 is rotated. is pressed into the arrival pit H ₂ direction while. In addition, when the leading conduit 40 having a predetermined length corresponding to the stroke length of the left hydraulic cylinder 26 and the right hydraulic cylinder 27 is press-fitted into the ground according to the above procedure, the left hydraulic cylinder 26 and the right hydraulic cylinder are again inserted. 27 is driven to return to the original state, and a new front conduit outer tube (reference numeral is omitted) is welded to the rear end of the front conduit outer tube 42, and the front inner tube 42 is also connected. Add in the same way. Incidentally, the leading extravascular tube 41 is not always necessary annex continuously until it reaches the arrival pit H _2, stop the annex in the middle, may be topped only lead tube pipe 42.

By repeating these operations, the leading end of the lead pipe tube 42 constituting the lead pipe 40, which is a spliced are in long reaches into the arrival pit H _2, remove the drill bit 43, the distal conduit tube As shown in FIG. 8, the tip of 42 is fixed to the inner wall of the reaching shaft H < _b > ₂ by the fixing bracket 44. Then, using the above propulsion unit 20 is pulled out only the leading extravascular pipe 41 starting pit H ₁ direction (1 step eye termination). Then, after all of the outer pipe 41 is pulled out, the buried pipe P is sequentially buried using the underground propulsion device 1 as a second process.

The underground pipe construction method using the underground propulsion device 1 is as follows. First, the end portion of the leading pipe inner pipe (hereinafter simply referred to as the leading pipe 40) 40 on the start shaft H ₁ side is connected to the excavation head 5. The tip of the cylindrical part 4a which comprises the said screw 4 is fixed to the back surface of this excavation head 5 next through the formed through-hole 8c. Next, the tip conductor 2 is positioned outside the screw 4, and the screw 4 is inserted into the inner cylinder 3 while the inner cylinder 3 is inserted into the tip conductor 2. Set as follows. By inserting the inner cylindrical body 3 into the leading conductor 2, the other engaging portion 7 a fixed to the tip of the inner cylindrical body 3, and one engaging portion 6 b formed on the leading conductor side ring 6, Engage each other. Therefore, by pressing the inner cover 3 to the arrival pit H ₂ direction, it is also pressed lead body 2. Therefore, the rear end of the (short) inner cylinder 3 is engaged with an outer positioning portion 25a provided on the slide member 25 of the propulsion device 20, and the cylindrical portion 4a constituting the (short) screw 4 is engaged. The rear end is fixed to the rotating board 30. When such operation is completed, is advanced driving the propulsion unit 20, thereby pressing the screw 4 and the inner cylindrical body 3 to the front (arrival pit H ₂ side), rotated forward the six drive motors 31. By such work, the excavation head 5 rotates forward and the ground is excavated by the excavation bit 15 fixed to the front of the excavation head 5 (the head main body 8). The drilling head 5 and the screw 4 are advanced while being guided by a leading conduit 40 inserted into a cylindrical portion 4a constituting the screw 4. Note that sediment excavated by the excavating head 5 is moved to the rear side from the outer peripheral side of該掘cutting head 5, is transported to the starting pit H ₁ further passes through the tubular body 3 above. Sediment were transferred to the starting pit H ₁ thus, by means not shown, is conveyed to the ground.

When the predetermined length (the stroke length of the left hydraulic cylinder 26 and the right hydraulic cylinder 27) is promoted, the screw 4 and the inner cylinder 3 are then added, and the buried pipe P is welded to the leading conductor 2. To do. When such operation is completed, using the propulsion unit 20 across again propel the arrival pit H ₂ directions. FIG. 9 schematically shows a state after a plurality of propulsion pipes P are laid on a predetermined distance while being connected to the leading conductor 2 in such a manner. In this state, when the excavation head 5 hits an obstacle (not shown) such as gravel or concrete in the ground and does not advance further than the position, the drive of the drive motor 31 is once stopped, and then the drive The motor 31 is reversely rotated. Due to the reverse rotation of the drive motor 31, the excavation head 5 also rotates in the reverse direction, and the first to third moving plates 9, 10, and 11 whose front ends have protruded (opened) until then are described above. Thus, due to the resistance between each excavation bit 15 and the earth and sand, the state rotates from the state shown in FIG. 2 around the respective support shafts 12, 13, and 14 in the counterclockwise direction in FIG. 2 to the state shown in FIG. . That is, the first to third moving plates 9, 10, and 11 whose leading ends have protruded to the outside of the head main body 8 are accommodated in the first to third thin portions 8d, 8e, and 8f, and the head main body 8 It will be in the state which does not protrude outside from the outer periphery. Then, after the screw 4 is moved forward (starting position direction) after the state shown in FIG. 3, one of the reduced diameter surfaces 8 b formed on the excavation head 5 is brought into contact with the inner cylinder side ring 7. When it joins with the other diameter-reduced surface 7c formed and the screw 4 is further moved forward, the screw 4 and the inner cylindrical body 3 are integrally moved (pulled out).

Explaining such a drawing operation or exchanging operation of the excavation head 5, first, the rear end of the screw 4 is fixed to the propulsion unit 20, and the (right and left) hydraulic cylinders 26 and 27 are driven to excavate the tip. the screw 4 and the inner cylindrical body 3 of the head 5 is fixed predetermined length drawer (left hydraulic cylinder 26 and the right hydraulic stroke length of the cylinder 27) min only in the starting pit H ₁ of the site replenishment earlier It is removed while cutting or releasing the fastening state with bolts and nuts (not shown), and the hydraulic cylinders 26 and 27 (left and right) are driven again to pull out a predetermined length. Figure 10 is a drilling head 5 and the screw 4 and the inner cylindrical body 3 is drawn slightly starting pit H ₁ direction, which shows an enlarged state after slightly moved, FIG. 11, the leading body 2 and It shows the middle of the excavation head 5, the screw 4, and the inner cylinder 3 being pulled out with the laid buried pipe P remaining. By repeating these operations, already laid down by the leading body 2 and buried pipe P while intact, it is possible to move the drill head 5 until inside the starting pit H _1, in this state, a separate drilling head Exchange. After the excavation head is replaced with a new excavation head, the other engagement formed on the inner cylinder side ring 7 as shown in FIG. and engaging portion 7a, and one of the engagement portions 6b formed leading side ring 6 so that advanced until engaging with one another, in the manner previously described is, laying buried pipe P until arrival pit H _2.

After the ground propulsion apparatus 1 is promoted to arrival pit H ₂ in the manner described above, the like work when replacing a drilling head 5, using the propulsion unit 20 installed in the starting pit H ₁ while, as shown in FIG. 12, sequentially extracted drilling head 5 and the screw 4 and the inner cylindrical body 3 in the starting pit H ₁ direction, removing the leading side ring 6 fixed to the lead body 2 which is left. The leading conductor 2 and a number of the buried pipes P subsequent thereto are formed in the same diameter from the same material, so that they remain in the ground as a part of the buried pipe P.

Thus, according to the underground propulsion apparatus 1, obstacles such as gravel and concrete exist in the course of propulsion, and there is a need to replace the excavation head 5 used so far with a new excavation head. even if not necessary to extract previously until all starting pit H ₁ a buried pipe P was laid, the buried pipe P can be exchanged as is. Therefore, according to this underground propulsion apparatus 1, it is possible to prevent the risk of ground subsidence due to the collapse of the cavity formed after the already laid buried pipe P is pulled out, and using a filler or the like The work of filling the cavity is not necessary, the work period can be shortened, and the cost can be reduced.

In the ground propulsion apparatus 1 according to the above embodiment, the present invention shall be guided to advance a start position which is a position reached from starting pit H ₁ arrival pit H ₂ lead pipe 40 laid over the However, the present invention does not necessarily need to have a structure guided by such a leading conduit 40. That is, it is not necessary to form the through hole 8c through which the leading conductor 40 is inserted at the center of the excavation head 5, and the axis of the screw 4 is a cylindrical portion 4a through which the leading conductor 40 is inserted. There is no need to be.

It is a sectional side view which shows the principal part of the underground propulsion apparatus which concerns on embodiment. It is a front view of the excavation head which shows the state after the 1st thru | or 3rd moving board opened. It is a front view of the excavation head which shows the state after the 1st thru | or 3rd moving board closed. It is a front view which shows a propulsion machine. It is a right view which shows a propulsion machine. It is a rear view which shows a propulsion machine. It is a side view which shows typically the process of laying a front conduit. It is a side view which shows typically the process of removing the front pipe outer pipe | tube which comprises a front pipe. It is a side view which shows typically the propulsion process of an underground propulsion apparatus. It is a side view which expands and shows the state by which the excavation head etc. were pulled a little in the start shaft direction in the state which left the front conductor and the buried pipe. It is a side view which shows the state by which the excavation head etc. were pulled in the start shaft direction in the state which left the front conductor and the buried pipe. It is a side view which shows the state by which the excavation head etc. were pulled in the starting shaft direction after laying a buried pipe to a reaching shaft.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Underground propulsion apparatus 2 Lead conductor 3 Inner cylinder 4 Screw 5 Excavation head 6 Lead conductor side ring 6b One engagement part 7 Inner cylinder side ring 7a The other engagement part 7c The other diameter reduction surface 8 Head main body 8b One Reduced diameter surface 9 First moving plate 10 Second moving plate 11 Third moving plate 12 First support shaft 13 Second support shaft 14 Third support shaft 15 Drilling bit H ₁ Start shaft H ₂ Arrival shaft

Claims (5)

A cylindrical tip conductor that is pressed in the direction of the arrival position by the propulsion device arranged at the start position and has a buried pipe continuous at the rear, an inner cylinder inserted into the tip conductor, and arranged in the inner cylinder An underground propulsion device comprising a screw having a spiral structure on the outer periphery and a rotatable screw, and a drilling head fixed to the front end of the screw and having a plurality of drilling bits fixed to the front surface,
The excavation head has an outer diameter smaller than the inner diameter of the leading conductor and an outer diameter larger than the outer diameter of the inner cylinder, and is formed in a substantially disc shape, and is rotated in front of the head body. It has a plurality of pivot plates that are pivotally supported and have a drilling bit fixed on the front,
The plurality of rotating plates are moved so that the excavation bit receives the resistance of the soil in the ground during the forward rotation of the head body, and the tip protrudes outside the outer periphery of the leading conductor, and during the reverse rotation, An underground propulsion device, wherein the excavation bit receives the resistance of underground soil and is moved so as to move inward from the outer periphery of the head body.   2. The ground according to claim 1, wherein a regulating portion is formed on a front surface of the head main body to prevent the rotation plates that have moved when the head main body is rotated in a reverse direction and from further moving. Medium propulsion device.   In the center of the head body, a circular through hole into which a guide tube propelled and installed in the ground is inserted is formed in advance, and the same axis as the through hole is formed in the center of the screw. The underground propulsion device according to claim 1, wherein a cylindrical portion through which the guide tube is inserted is formed.   A front-conductor-side ring having one engaging portion is fixed to the tip of the leading conductor, and the other engaging portion that engages with the one engaging portion is formed at the tip of the inner cylinder. 4. The ground according to claim 1, 2 or 3, wherein an inner cylinder side ring that cooperates with the front conductor side ring and closes between the front conductor and the inner cylinder is fixed. Medium propulsion device. The outer peripheral surface of the excavation head is formed with one reduced diameter surface that is gradually reduced in diameter toward the back side, and the inner peripheral surface of the inner cylinder side ring is the one formed on the excavation head. 5. The underground propulsion device according to claim 4, wherein the other reduced diameter surface is formed so as to be gradually reduced in diameter corresponding to the reduced diameter surface.