JP4603994B2 - Pipe roof forming pipe - Google Patents

Description

  In the present invention, when an underground structure serving as an underground passage is embedded and constructed in a ground directly below the track or the road across the track or the road, the underground structure precedes the underground structure. The present invention relates to a pipe for forming a pipe roof that serves as a guide when propelling an object.

Conventionally, as a method of constructing an underground passage by burying an existing underground structure in the ground under a track or under a road, for example, as described in Patent Document 1, a blade edge is attached to the front end. The underground structure is installed on the start side, and a plurality of receiving pipes are juxtaposed along the lower surface of the upper wall of the blade edge at least in front of the upper floor of the underground structure to form a pipe roof. Protruding jacks between the rear end face of each receiving pipe and the front end face of the upper floor portion of the underground structure and extending the rods of these propulsion jacks to propel the front end face of the upper floor portion of the underground structure While receiving the reaction force, the receiving pipe is sequentially excavated toward the arrival side by a certain length, and then the towing means installed on the arrival side of the underground structure or the propulsion jack installed on the departure side More forward than propulsion means Fixed length Te, and embedded in the ground, buried in the burying plan area of the underground construction By repeating this, it has been practiced to construction.
JP-A-56-125597

  As described above, in order to dig a pipe roof into the ground for a certain length in advance of the underground structure, a plurality of receiving pipes forming the pipe roof are addressed to one, and are sequentially propelled by a propulsion jack. In this case, all the receiving pipes always have their front end openings facing the front excavation ground. When the receiving pipe other than the receiving pipe under excavation is in a stopped state without propulsion, when the face ground is a soft ground with small independence, etc. The ground in front collapses and enters the front end opening of the receiving pipe that is stopped, and the shallow ground under the track and under the road that must be supported by the pipe roof relaxes, causing ground subsidence, etc. , There is a possibility to inhibit through.

  The present invention has been made in view of such problems, and the purpose of the present invention is to reliably prevent the ground from collapsing inside by stopping the earth of the face during stoppage, It is in providing the pipe roof formation pipe which can carry out excavated earth and sand smoothly back.

In order to achieve the above object, the pipe roof forming pipe according to the present invention, as set forth in claim 1, is used to advance and embed an underground structure in the ground prior to the underground structure. A pipe roof forming pipe to be propelled to the inside of the pipe body is provided with a spiral blade for carrying out earth and sand on the outer peripheral surface, and an inner spiral blade for carrying back gravel etc. on the inner peripheral surface. The inner tube is rotatably arranged, and a cutter head is integrally provided at the front end opening of the inner tube. Further, an expandable / contractible shutter is disposed on the back side of the cutter head. The front end opening of the pipe body is closed by widening.

  In the pipe roof forming pipe configured as described above, the invention according to claim 2 is characterized in that the shutter has a shaft projecting rearward from the center of the cutter head and the outer periphery of the front end of the shaft. A plurality of shutter pieces radially provided on the surface and pivotally mounted in a undulating manner in the front-rear direction, a flexible sheet that is foldable between opposing edges of the shutter pieces, and slidable on the shaft A sliding piece connected to each shutter piece via a link and a jack mounted on the shaft to slide the sliding piece in the front-rear direction. The flexible sheet is configured to expand and contract by being moved. According to a third aspect of the present invention, the shutter piece in the shutter is formed in a shape in which the outer peripheral end surface is an arcuate end surface along the inner peripheral surface of the inner tube and becomes narrower toward the inner peripheral end. It is characterized by being.

According to the invention according to claim 1, when the underground structure is propelled and buried in the ground, the pipe roof forming pipe is propelled into the ground prior to the underground structure. An inner pipe provided with spiral blades for carrying out sediment on the outer peripheral surface is rotatably arranged inside, and a cutter head is integrally provided at the front end opening of this inner pipe. The cutter head can efficiently excavate the ground in front, and the excavated earth and sand can be efficiently carried out backward by the spiral blades protruding from the outer peripheral surface of the inner pipe. since the spiral blade to the inner peripheral surface provided, it is possible to unload the gravel or the like to the rear through the inside tube, the promotion of the pipe roof, the construction is carried out smoothly shortened buried installation construction period of underground structures and Can be planned.

  In addition, an expandable / contractible shutter is provided on the back side of the cutter head facing forward from the front end opening of the pipe body, and the front end opening of the pipe body is closed by expanding the shutter. Therefore, when the pipe body is dug, the pipe body can be easily dug while the earth and sand are dug and carried out by the cutter head and the inner and outer spiral blades by reducing the shutter. The front end opening of the pipe body can be closed by expanding this shutter when stopping the operation, and the face is grounded by this shutter to ensure that the face ground collapses and enters the pipe body. Therefore, the upper ground of the underground structure to be propelled and buried under the track and under the road is shallow with earth cover. Promotion of underground construction while preventing its collapse there is, it is possible to burying operation is performed with high efficiency.

  According to a second aspect of the present invention, the shutter includes a shaft projecting rearward from the center portion of the cutter head, and a plurality of the shutters are radially provided on the outer peripheral surface of the front end portion of the shaft, and in the front-rear direction. A shutter piece pivotably mounted on the shaft, a flexible sheet foldably disposed between opposing edges of the shutter piece, and each shutter provided on the shaft slidably through a link. A sliding piece connected to the piece and a jack that is mounted on the shaft and slides the sliding piece in the front-rear direction. The flexible sheet is formed by sliding the sliding piece in the front-rear direction. Because it is configured to expand and contract, it is possible to easily expand and contract each shutter piece while moving the sliding piece on the shaft in the front-rear direction by bending and extending the jack to refract the link like an umbrella bone. In In this case, the flexible sheet piece connecting between the opposite side edges of the adjacent shutter pieces is tensioned at the time of enlargement, and the entire shutter can be greatly expanded like an umbrella so that it can be expanded into the pipe body. It is possible to reliably prevent the face ground from entering.

  In addition, when the shutter is reduced, the flexible sheet piece connecting between the opposing side edges of the adjacent shutter pieces is folded into a pleat shape, so that the shutter can be reduced smoothly. When the shutter is contracted, the shutter can be folded along the shaft provided at the center of the inner tube, and the jack for expanding and contracting the shutter is also mounted on the shaft. During the excavation of the pipe body, these shutters and jacks have no influence on the excavated earth and sand taken into the pipe body, and the excavated earth and sand can be smoothly carried out by the inner and outer spiral blades.

  As the shutter piece, as described in claim 3, a planar member having an outer peripheral end surface formed on an arcuate end surface along the inner peripheral surface of the inner tube and narrowing toward the inner peripheral end. Is used, and the earth retaining action is performed together with the flexible sheet by the plate surface. However, the shutter piece may be formed in a rod shape.

  A specific embodiment of the present invention will be described with reference to the drawings. FIGS. 1 to 3 show an arrival shaft (not shown) from the start shaft B side in the ground directly below a road or a track (hereinafter referred to as a track A). When the underground structure C is propelled and buried toward the ground to construct the underground passage that crosses the track, the lateral width is approximately equal to the width of the underground structure C on the front side of the upper floor C1 of the underground structure C. The pipe roof P is disposed and the pipe roof P is propelled forward by a predetermined length toward the reaching shaft, and the process of propelling the underground structure C by a predetermined length is repeated following this process. This shows the state in which the underground structure C is buried in the ground, and the underground structure C is made of a ready-made reinforced concrete box having a rectangular cross section penetrating in the front-rear direction, and has a blade at the front end opening. Wearing mouth D.

  The blade edge D has a rear end frame portion D1 having substantially the same cross-sectional shape as the rectangular cross section of the underground structure C joined to the front end surface of the underground structure C and is fixed integrally therewith. Constantly moving forward from the upper surface of the upper floor portion C1 of the underground structure C at the front upper end portion by a distance equal to the thickness of the upper floor portion C1 or below the thickness of the upper floor portion C1. A base plate D2 having a length that protrudes horizontally, and a lower frame portion that is shorter than the length of the base plate D2 at the front lower end portion of the rear end frame portion D1 and has a tip formed at the blade edge portion. D3 is projected forward, and the front plate D2 and the lower frame portion D3 are connected together by slanted frame portions D4 and D4 inclined obliquely rearward from the upper end to the lower end. In addition, a blade edge portion is formed over the entire length at the front ends of the both side inclined frame portions D4 and D4.

  The rear lower surfaces of the plurality of pipes 1 forming the pipe roof P on the front half of the base plate D2 of the blade edge D configured in this way are individually supported so as to be movable forward. Yes. As shown in FIG. 4 and FIG. 5, the pipe 1 has a pipe body 1a made of a steel pipe having a rectangular cross section with a certain length, and spiral blades 2 and 3 for carrying out sediment on the inner and outer peripheral surfaces. An inner pipe 1b made of a steel pipe having a circular cross section, which is fixed to the front end of the pipe body 1a and is fixed to the front end of the pipe body 1a. An expandable / shrinkable shutter 5 is provided on the back side of the head 4 and the shutter 5 is expanded to close the front end opening of the pipe body 1.

  The shutter 5 has a front unequal leg trapezoidal shape in which the outer peripheral end surface is formed as an arcuate end surface along the inner peripheral surface of the inner tube 1b and the width between both end surfaces gradually decreases from the outer peripheral end surface toward the inner peripheral end. A plurality of shutter pieces 5a made of a metal plate or a hard synthetic resin plate formed at a predetermined interval in the circumferential direction, and the opposing edge of the adjacent shutter pieces 5a, 5a is folded in a pleat shape. It is connected by a flexible sheet piece 5b in the shape of a fan-shaped piece such as a cloth or a synthetic resin sheet, and the inner end of each shutter piece 5a protrudes rearward from the center of the cutter head 4 When it is erected on the outer peripheral surface of the bearing piece 7 fixed to the front end of the shaft 6 so that it can be swung up and down in the front-rear direction, it expands into a front circular umbrella and tilts backward. In this case, as shown in FIG. 6 and FIG. It is formed so as to be folded shifted 6 so as to cover. The shutter piece 5a is not limited to a planar member such as a front unequal foot trapezoidal shape but may be a rod-shaped member.

  The expansion / contraction means of the shutter 5 includes a small-diameter cylindrical slide piece 8 fitted on the shaft 6 at the rear of the shutter 5 so as to be slidable back and forth, and the outer periphery of the slide piece 8 and the shutter pieces 5a. The ends are rotatably connected by a link 9 and two hydraulic jacks 10 and 10 are arranged along the shaft 6 on the rear side of the sliding piece 8 in the length direction of the shaft 6. The rod ends of these hydraulic jacks 10, 10 facing forward are connected to the sliding piece 8 while the rear ends thereof are connected in parallel to the fixing member 11 fixed to the shaft 6. By connecting and extending the rods of the hydraulic jacks 10 and 10, the shutter pieces 5 a are undulated in the front-rear direction via the links 9 to expand and contract the shutter 5.

  The shaft 6 is disposed at the center of the inner tube 1b and the front end thereof is supported by the center of the cutter head 4 as described above, while the rear end is the center of the rear end of the inner tube 1b. Further, the shaft 6 is formed in a hollow shape, and a pressure oil pipe (not shown) connected to the hydraulic jacks 10 and 10 is disposed in the hollow portion, and at the rear end of the shaft 6. A rotary joint (not shown) is connected, pressure oil is supplied from outside the rear end of the pipe 1 to the pressure oil piping through the rotary joint, and the hydraulic jacks 10 and 10 are operated. Such a pressure oil supply path may be provided with a pressure oil pipe along the inner peripheral surface of the inner pipe 1b without using the shaft 6.

  The inner diameter of the inner tube 1b is larger than the width of the outer peripheral surface of the inner tube 1b and the flat tube wall inner surface of the pipe body 1a having a rectangular cross section. The sediment transport passage 13 formed by the space portion in the inner pipe 1b is made larger than the sediment transport passage 12 formed by the space portion between the inner peripheral surfaces. It is configured to be taken in and to be carried out rearward by the inner spiral blade 3 having a fixed height protruding from the inner peripheral surface of the inner tube 1b.

  Further, the cutter head 4 fixed to the front end opening of the inner tube 1b has a plurality of cutters on the front surface in the radial direction from the outer peripheral surface of the center member 4a projecting the center bit 4a 'on the front surface. Several spoke bodies 4b (in the figure, 3) projecting from the bit 4b 'project radially, and the space between the adjacent spoke bodies 4b, 4b is drilled earth or gravel. Are formed in the earth and sand intake port 14 having a size that can be taken in, and an arm piece 4c is projected rearward on the rear surface of the outer end of each spoke body 4b, and the rear end of the arm piece 4c is The inner tube 1b is configured to be fixed to a connecting piece 4d projecting outward from the outer peripheral surface of the front end opening of the inner tube 1b and rotated integrally with the inner tube 1b.

  Further, as shown in FIG. 9, earth discharge ports 15 and 16 are provided on the rear end peripheral walls of the pipe main body 1a and the inner pipe 1b, respectively, and an end face plate 17 is provided at the rear end opening of the pipe main body 1a. The rear end portion of the inner tube 1b is rotatably supported by the end face plate 17, and a rotation described later is provided at the rear end of the rotating shaft that protrudes rearward from the central portion of the rear end of the inner tube 1b. A clutch piece 24 fixed to the front end of the rotating shaft of the drive motor 22 and a clutch piece 18 detachably locked are fixed.

  As shown in FIGS. 1 to 3 and 8, the pipe 1 configured in this way has a width of the base plate D <b> 2 on the base plate D <b> 2 of the blade D attached to the front end opening of the underground structure C. The pipe roof P is formed by arranging the rear end of the base plate D2 so as to be slidable in the front-rear direction in parallel with each other in the direction. Further, the pipe body 1a is formed to have a height (thickness) whose upper surface is flush with the upper surface of the upper floor portion C1 of the underground structure C and is substantially equal to the width of the pipe body 1a on the upper surface. A friction cut plate 19 made of a strip steel strip having a certain width is placed, and the front end thereof is integrally fixed to the upper surface of the front end of the pipe body 1a by welding, and the friction cut plate 19 is attached to the pipe body 1a. The rear part is extended backward from the rear end, and the rear part thereof is slidably mounted on the upper surface of the upper floor part C1 of the underground structure C so as to be exposed rearward from the wellhead of the start shaft B.

  Further, between the rear end of the pipe roof P composed of the plurality of pipe rows and the front surface of the upper end portion of the rear end frame portion D1 of the blade edge D in contact with the front end surface of the upper floor portion C1 of the underground structure C. As shown in FIGS. 8 and 9, a space portion on the base plate D2 of the blade opening D is formed in a work space portion 20 that is long in the width direction of the upper floor portion C1, and this work space portion 20 is formed as a pipe 1. Covering with the middle part in the length direction of the friction cut plate row extending in a erected state between the upper surface of the upper floor part C1 of the underground structure C from the upper surface of the rear end and supporting the upper ground by this middle part, It prevents the earth and sand from collapsing in the work space 20.

  In the work space 20, a lateral movement is possible in the width direction of the underground structure C along the front surface of the upper end of the rear end frame D 1 in contact with the front end surface of the upper floor C 1 of the underground structure C. A movable carriage 21 is disposed, and a front and rear movable platform 23 is disposed on the laterally movable carriage 21 and a rotational drive motor 22 for rotationally driving the inner pipe 1b in the pipe body 1a is disposed. Yes. At the front end of the rotary shaft of the rotary drive motor 22, a clutch piece 24 that is engaged with and disengaged from the clutch shaft 18 that is fixed to the rotary shaft protruding rearward from the center of the rear end of the inner pipe 1b is fixed. In addition, pipe propulsion jacks 25, 25 are fixed on both sides of the front / rear moving table 23. The spreader 26 integrally connects the ends of the rods facing backward in the pipe propulsion jacks 25, 25. ing.

  Further, as shown in FIGS. 9 and 10, locking pieces 27 are projected downward on the lower surfaces of both sides of the rear end of the spreader 26, while these are formed on the upper surfaces of both sides of the rear end of the laterally moving carriage 21. A stopper piece 28, which is disposed on the front side of the locking piece 27 and receives the front end surface of the locking piece 27, projects upward, and when the rods of the pipe propulsion jacks 25 and 25 are extended. In this case, the locking piece 27 is separated from the stopper piece 28 rearward, and when the rod is contracted, the locking piece 27 is received by the stopper piece 28 and the rod is further contracted from this state. The front and rear moving table 23 is configured to move backward with the portion as a fulcrum.

  On the other hand, in FIG. 1 and FIG. 2, the above-mentioned underground structure C is installed on a bottom slab (not shown) whose upper surface laid on the bottom surface of the start shaft B is slidably movable in the front-rear direction. A plurality of underground structure propulsion jacks 32 are arranged between a reaction force receiver 30 arranged on the rear end face of the underground structure C and the front retaining wall 29 of the start shaft B through a plurality of spacers 31. The front end face of the propulsion jack 32 is fixed in a state where it is pressed against the rear face of the press ring 33 joined to the rear end face of the underground structure C, and the tip of the rod of the propulsion jack 32 protruding rearward is fixed. The underground structure C is brought into the ground from the entrance of the start shaft B by extending the rod of the propulsion jack 32 by contacting and receiving the front surface of the frontmost spacer 31 made of a plate material or a frame material having a certain thickness. It is configured to be propelled and buried in.

  The underground structure C is propelled and buried by sequentially propelling all the pipes 1 constituting the pipe roof P into the ground by a predetermined length and after the constant length propulsion process of the pipe roof P. This is performed by sequentially repeating the step of propelling the object C by the same length. In addition, when the friction cut plate 19 drawn out from the pipe 1 to the upper floor C1 of the underground structure C behind it is propelled together with the pipe 1 and embedded in the ground for a certain length, it starts. The front end face of the next fixed length friction cut plate is abutted with the rear end face of the friction cut plate 19 exposed in the shaft B, and is added by welding.

  When the pipes 1 constituting the pipe roof P are sequentially excavated by a predetermined length, the front end openings of the pipe bodies 1a in all the pipes 1 other than the pipes 1 to be propelled are previously closed by the shutter 5. On the other hand, the front end opening of the pipe body 1a in the pipe 1 to be propelled is left in a fully open state. In order to close the front end opening of the pipe body 1a with the shutter 5, pressure oil is supplied from the rear side of the pipe 1 to the hydraulic jack 10 disposed on the shaft 6 in the front end of the inner pipe 1b in the pipe 1. When the rod is extended, the sliding piece 8 connected to the rod slides forward on the shaft 6 and links with the shutter piece 5a which connects the outer ends to each other so as to be rotatable. 9 is erected in the outer diameter direction with the bearing piece 7 pivotably attached to the inner end portion thereof while being refracted from each other and the sliding piece 8 as a fulcrum, and accordingly between the adjacent shutter pieces 5a and 5a The flexible sheet piece 5b is unfolded and the entire shutter 5 is expanded in an umbrella shape as shown in FIGS.

  In this way, when the front end opening of the pipe body 1a is closed by the shutter 5, the face ground is prevented from collapsing by the shutter 5 and is maintained in a self-supporting state while preventing the upper ground from being relaxed. The underground structure C can be promoted and buried.

  On the other hand, in order to contract the shutter 5 and fully release the front end opening of the inner tube 1b, when the pressure oil is supplied to the hydraulic jack so that the rod contracts, the sliding piece 8 moves on the shaft 6. The shutter piece 5a and the link 9 which are reversely connected to each other so that the outer end portions are pivotably connected to each other are supported by the bearing piece 7 and the sliding piece 8 which are pivotally attached to the inner end portion thereof. As shown in FIGS. 6 and 7, the flexible sheet piece 5b between the adjacent shutter pieces 5a and 5a is folded into a pleat shape and stored along the shaft 6, and the pipe body 1a The front end opening is fully released.

In order to sequentially dig the pipe 1 constituting the pipe roof P by a predetermined length, the laterally movable carriage 21 is driven in the work space portion 20 provided in front of the upper floor portion C1 of the underground structure C. Then, it is moved to the rear of one pipe 1 to be propelled and stopped at that position, and is disposed on both sides of the front and rear moving table 23 on the laterally moving carriage 21 as shown in FIG. By extending the pipe propulsion jacks 25, 25, the spreader 26 connecting the rear ends of the rods is brought into contact with and received by the rear end frame portion D1 of the blade D, and propelled by the rear end frame portion D1. When the rod is further extended with the reaction force applied, the front / rear moving base 23 moves forward, and the clutch piece 24 attached to the tip of the rotary shaft of the rotary drive motor 22 installed on the front / rear moving base 23 is The clutch piece 18 fixed to the rear end rotation shaft of the inner tube 1b is engaged .

When the inner tube 1b is rotated by operating the rotary drive motor 22 in this state and the pipe propulsion jacks 17 and 17 are further extended, as shown in FIG. While the reaction force is received, the forward / backward moving table 23 moves forward, and the pipe 1 is propelled integrally with the friction cut plate 19 placed on the upper surface while excavating the front ground by the cutter head 4. The excavated soil is taken into the outer sediment transport passage 12 between the pipe body 1a and the inner tube 1b and the inner sediment transport passage 13 in the inner tube 1b through the soil intake port 14 of the cutter head 4, and the inside and outside of the inner tube 1b. It is carried out backward by the spiral blades 2 and 3 provided integrally on the peripheral surface, falls from the sediment discharge ports 15 and 16, and moves to the start shaft B side through the underground structure C together with the excavated soil on the ground in front of the blade D Discharged. In this case, a large-diameter gravel or the like that cannot be taken into the outer sediment transport passage 12 is taken into the inner pipe 1b and carried backward in the inner pipe 1b by the spiral blade 3 .

  Thus, after digging one pipe 1 into the ground for a fixed length and then contracting the pipe propulsion jacks 25, 25, the spreader 26 is separated forward from the rear end frame D1 of the blade edge D, which is a reaction force receiver. At the same time, the locking piece 27 protruding downward from the spreader 26 abuts on the rear end surface of the stopper piece 28 protruding upward at the rear end of the laterally moving carriage 21, and is further separated When the pipe propulsion jacks 25, 25 are further contracted from this state, the forward / backward moving base 23 moves backward, and the clutch pieces 18, 24, which have connected the rotating shaft of the rotary drive motor 22 and the inner pipe 1b, The connection is broken.

  Thereafter, the laterally moving carriage 21 is laterally moved behind the next pipe 1 to be propelled, and the shutter 5 of the pipe 1 is released again in the same manner as described above, while the shutters 5 of the other pipes 1 are closed. Then, the rods of the pipe propulsion jacks 25, 25 are extended and the rotary drive motor 11 is driven to dig the pipe 1 by the same length as the pipe 1 propelled first.

  Thereafter, the pipes 1 are sequentially excavated in the same manner, and all of these pipes 1 constituting the pipe roof P are excavated for a certain length, and then a plurality of propulsion units arranged in the start shaft B are provided. The same as the above-mentioned pipe roof P while extending the jack 32 and applying a reaction force to the reaction force receiver 30 through the spacer 31 so that the upper surface of the upper floor portion C1 slides on the lower surface of the friction cut plate row. Only the propulsion head is propelled forward.

  In this way, each pipe 1 is sequentially excavated in the horizontal direction by the laterally moving carriage 21 in which the front and rear moving base 23 is arranged, and the pipe roof P made of these pipe rows is moved forward by a certain length toward the reaching vertical shaft side. And after this step, the propulsion jack 32 disposed on the start shaft B side is extended so as to be in contact with the lower surface of the pipe roof P by the same distance as the pipe roof P. The underground structure C is made to reach the reaching shaft side by repeatedly performing the step of propelling forward, and an underground passage by the underground structure C is constructed between the starting shaft B and the reaching shaft.

  At this time, every time the pipe roof P is propelled for a certain length, the friction cut plate 19 in which only the front end of each pipe 1 is fixed to the upper surface of the front end of the pipe 1 by welding is also integrally propelled to the start shaft B. Therefore, before the rear end portion of the friction cut plate 19 enters the ground from the start shaft B, a certain length is applied to the rear end surface of each friction cut plate 19. In the same manner as described above, welding is performed in a state in which the front end surfaces of the new friction cut plates are joined to each other, and again, the propulsion of the pipe roof P and the propulsion of the underground structure C following the propulsion are performed again. Repeat.

  Similarly, each time the underground structure C is excavated into the ground for a predetermined length, a spacer 31 having a thickness corresponding to the excavation length is interposed in the start shaft B at the rear side of the propulsion jack 32, and the underground structure When the length of the underground passage to be constructed by the object C is long, the underground structure of a certain length obtained by dividing the length of the underground passage into several parts is sequentially joined and connected to be propelled to reach the reaching shaft, and start An underground passage by the underground structure C is constructed between the shaft B and the reaching shaft. In the above-described embodiment, the underground structure C is constructed on the direct foundation board of the track A, but it is needless to say that the underground structure 1 can be constructed by the same method as described above even under the road.

A simplified longitudinal side view of an underground structure propelled underground. The simplified plan view. The simplified front view of a pipe roof. The expanded vertical side view of the front-end part of a pipe provided with the shutter. The front view of the state which cut off the center part of the cutter head. The expanded vertical side view of the pipe front-end part which shows the state which folded the shutter. The front view of the state which cut off the center part of the cutter head. The partially abbreviate | omitted top view of the state which was located in the back of the pipe which should drive a horizontal movement trolley | bogie. The longitudinal side view. The vertical side view of the state which is pushing the pipe.

Explanation of symbols

A Track B Start shaft C Underground structure P Pipe roof 1 Pipe
1a Pipe body
1b Inner tube 2, 3 Inner and outer spiral blades 4 Cutter head 5 Shutter
5a Shutter piece
5b Flexible sheet piece 6 Shaft 8 Sliding piece 9 Link
10 Hydraulic jack

Claims (3)

When a underground structure is propelled and buried in the ground, it is a pipe roof forming pipe that is propelled underground before the underground structure, and is used for carrying out sediment on the outer peripheral surface of the pipe body. An inner pipe provided with a spiral blade and an inner spiral blade for carrying gravel etc. to the rear on the inner peripheral surface is rotatably arranged, and a cutter head is integrated with the front end opening of the inner pipe. And a pipe roof characterized in that a shutter which can be expanded and contracted is provided on the back side of the cutter head, and the front end opening of the pipe body is closed by expanding the shutter. Pipe for forming.   The shutter has a shaft projecting rearward from the center of the cutter head, a plurality of shutter pieces radially provided on the outer peripheral surface of the front end of the shaft, and pivotally pivoted in the front-rear direction, and the shutter A flexible sheet that is foldably disposed between opposite edges of the piece, a sliding piece that is slidably provided on the shaft and connected to each shutter piece via a link, and a shaft And the flexible sheet is configured to expand and contract by sliding the sliding piece in the front-rear direction. The pipe roof forming pipe according to claim 1.   The pipe roof according to claim 2, wherein the shutter piece is formed such that an outer peripheral end surface is formed in an arcuate end surface along the inner peripheral surface of the inner tube and becomes narrower toward the inner peripheral end. Pipe for forming.

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