JP4745274B2 - Divertable shield excavator skin plate - Google Patents

Description

  The present invention includes a front barrel portion provided with a rotary cutter at the tip and a partition wall and a cutter driving device on the inner side, and a rear barrel portion on which the segment is assembled on the inner side. The present invention relates to a skin plate of a shield excavator that can be diverted at a shield construction site.

  The shield method starts excavating ground with a cutter while pressing the cut end surface of the shield excavator with mud, muddy water, pressurized air, etc., and assembling a tunnel lining body with segments behind the shield excavator. It is a method of forming a tunnel in the ground from the vertical shaft to the final shaft, and is widely used as a main tunnel construction method in urban and plain areas.

  The shield excavator used in the shield method is equipped with a rotating cutter that cuts the cut end face at the tip of a metal outer shell called a skin plate, and inside the skin plate, a partition wall, a cutter driving device, a soil removal mechanism, a shield A jack, an erector device, etc. are provided. The skin plate generally includes a front barrel portion provided with a rotary cutter at the tip, a partition wall and a cutter driving device on the inner side, and a rear barrel portion on which the segment is assembled on the inner side. Many skin plates having a middle folded middle body between the rear body and the rear body are also employed.

  The shield excavator digs through the ground while forming a tunnel from the starting shaft to the reaching shaft, but when the tip reaches the reaching shaft, it removes the rotary cutter and is installed inside the skin plate While the cutter drive device, earth removal mechanism, shield jack, erector device, etc. are removed through the reach shaft, the skin plate is generally left in the ground and buried as the outer shell of the tunnel. .

  Also, if the outer diameter of the skin plate by the shield excavator becomes large, for example, 3800 mm or more, it is difficult to carry the skin plate from the factory into the start shaft, so the front trunk, the rear trunk, After the middle folding body is carried in as a plurality of arcuate parts divided in the circumferential direction and joined together by welding etc. inside the start shaft, it will be propelled from the start shaft into the ground .

  According to such a shield excavator, the cutter driving device, the earth removal mechanism, the shield jack, the erector device, etc. removed from the shield excavator that has reached the reach shaft are prepared after unloading, in other shield construction sites. It will be reused. On the other hand, the skin plate was buried in the ground as the outer shell of the tunnel, but the skin plate becomes expensive when the outer diameter of the excavation by the shield excavator is large. It is desirable to dismantle and remove from the reach shaft without burying it so that it can be reused at other shield construction sites.

The skin plate can be disassembled and removed inside the vertical shaft by disassembling the skin plate by gas cutting, or as a unit in which the skin plate is divided into multiple units, and each unit is integrated using bolts and nuts. The skin plate can be disassembled by removing these bolts and nuts (see, for example, Patent Document 1).
JP 59-21895 A

  However, in the method of disassembling the skin plate by gas fusing, the skin plate is likely to be distorted due to high heat during cutting, etc., and a particularly high joining accuracy is required. For the middle-folded middle barrel that has a sliding part with respect to the front barrel, when it is reused at other shield construction sites, it takes a lot of work to repair the strained part, and it can be diverted. It can be difficult. Moreover, in the method of joining a plurality of units using bolts and nuts so that they can be disassembled, large earth pressure or water pressure acts, for example, when joining and integrating skin plates of shield excavators with a large depth and a large cross section, welding As compared with the bonding strength obtained by the above, it is difficult to obtain sufficient bonding strength, and the reliability during construction is lacking.

  The present invention has been made paying attention to such a technical problem, and it is possible to sufficiently secure the joining strength in the divided portion by joining by welding, and particularly where high joining accuracy is required. However, it is an object of the present invention to provide a skin plate for a diverted shield excavator that can be easily disassembled by cutting the joint portion while avoiding distortion.

  The present invention includes a front barrel portion provided with a rotary cutter at the tip and a partition wall and a cutter driving device on the inner side, and a rear barrel portion on which the segment is assembled on the inner side. A shield excavator skin plate that can be diverted at a shield construction site, wherein the front trunk portion and the rear trunk portion are each formed by joining and integrating a plurality of arc-shaped portions divided in the circumferential direction by main welding. The front body portion is overlapped with a pair of joint flanges provided so as to protrude radially inward of the front body portion from each arcuate portion along the dividing surface, and the inside of the front body portion By performing the main welding on the joining corners at the outer peripheral end surface portions of the pair of joining flanges, the joining strength necessary for joint integration is maintained, and the pair of joining frames subjected to the main welding are provided. By providing a skin plate for a divertable shield excavator, wherein the front body portion is disassembled into a plurality of arc-shaped portions by cutting joint corners at the outer peripheral end surface portion of the die. Is achieved.

  In the divertable shield excavator skin plate of the present invention, a plurality of arc-shaped portions divided in the circumferential direction are joined and integrated by main welding between the front body part and the rear body part. A pair of joint flanges provided so as to project radially inward from the respective arc-shaped portions along the dividing surface. And by joining the corners of the outer peripheral end faces of the pair of joint flanges inside the center part of the middle bent middle part, the joint strength necessary for joint integration is maintained, and It is preferable that the middle folded middle body portion is disassembled into a plurality of arc-shaped portions by cutting joint corner portions at outer peripheral end surface portions of the pair of joining flanges subjected to the main welding.

  Further, in the skin plate of the divertable shield excavator of the present invention, the pair of joint flanges are provided with alignment holes, respectively, and the pair of joint flanges are aligned via the alignment holes. In addition, it is preferable that the main welding is performed on a joining corner portion in the outer peripheral end surface portion.

  Furthermore, in the skin plate of the divertable shield excavator of the present invention, each of the pair of joint flanges is provided with a plurality of bolt fastening holes, and the bolts are aligned by aligning the bolt fastening holes. It is preferably fastened.

  Furthermore, in the skin plate of the divertable shield excavator of the present invention, a gap between the divided surfaces is filled in the outer peripheral surface of the front body part and / or the middle folded middle body part along the divided surface. Seal welding is preferably performed.

  Further, in the skin plate of the divertable shield excavator according to the present invention, the connecting flange provided to project radially inward from each arcuate portion along the dividing surface of the front body portion is provided with the partition wall and the cutter drive It is preferable that it is integrally joined to the holding holder of the apparatus.

  Here, in the above description, the main welding is performed in a predetermined thickness so as to obtain a necessary joint strength when joining and integrating a plurality of arc-shaped parts divided in the circumferential direction by welding, This welding is performed according to the length, groove depth, etc., and seal welding is a simple welding performed just in case that the sealing performance can be ensured by simply filling the gap without expecting the joint strength. It is.

  According to the skin plate of the divertable shield excavator of the present invention, by joining by welding, it is possible to sufficiently ensure the joining strength in the divided part, and even in places where particularly high joining accuracy is required, The joint portion can be cut and easily disassembled while avoiding the occurrence of distortion.

  A divertable shield excavator skin plate 10 according to a preferred embodiment of the present invention constitutes, for example, an outer shell of a mud pressure shield excavator 11 as a shield excavator as shown in FIG. The front body 12, the rear body 13, and the middle folded middle body 14 interposed therebetween. The mud pressure shield excavator 11 has a drilling outer diameter of about 4680 mm, for example, and includes a rotary cutter 15 at the tip of the skin plate 10 and a cutter driven inside the skin plate 10. A device 16, a soil removal mechanism 17, a shield jack 18, a center folding jack 19, an erector device 20 and the like are provided. In such a mud pressure shield excavator 11, each component member is brought into the start shaft and assembled, and then started toward the reaching shaft, and the tunnel is dug in the ground while forming a tunnel lining body by the segment 21 in the rear. At the same time, when it reaches the reaching shaft, it is dismantled by each constituent member and carried out from the reaching shaft.

  Moreover, in this embodiment, the front trunk | drum 12, the rear trunk | drum 13, and the middle folded middle trunk | drum 14 which comprise the skin plate 10 are large in the outer diameter, and it manufactures as an integral thing from a factory to a shield construction site. Since it cannot be transported, as shown in FIGS. 2 to 4, for example, semi-circular front trunk units 12a, 12b, respectively, along horizontal or substantially horizontal dividing surfaces Pa, Pb, Pc, The rear trunk unit 13a, 13b and the middle trunk unit 14a, 14b are loaded into the start shaft in a state of being divided into two parts in the vertical direction, and main welding 30 is applied to the divided parts (see FIG. 10 to FIG. 12). The skin plate 10 is formed by the cylindrical front body part 12, the rear body part 13, and the middle folded body part 14.

  Then, components such as the rotary cutter 15, the cutter driving device 16, the soil removal mechanism 17, the shield jack 18, the folding jack 19, and the erector device 20 that are dismantled from the mud pressure shield excavator 11 that reaches the reaching shaft are reached. While being repaired after being removed from the shaft and reused at other shield construction sites, according to conventional technology, the skin plate is generally left in the ground and buried as the outer shell of the tunnel However, such skin plates can also be dismantled and removed from the vertical shaft without being buried in the ground, and reused at other shield construction sites, for example, to reduce the cost of shield construction equipment. In order to make it possible, the skin plate 10 of the present embodiment has been adopted.

  That is, the skin plate 10 of the divertable shield excavator 11 according to the present embodiment has a front barrel portion 12 provided with a rotary cutter 15 at the tip and a partition wall 22 and a cutter driving device 16 inside, and an inner segment. 2 is a skin plate that is divided and dismantled at the reach shaft and can be used in other shield constructions, and includes FIGS. 2 (a), 2 (b) and 3 (a), (b). ), The front body portion 12 and the rear body portion 13 are joined and integrated by main welding of the front body units 12a and 12b and the back body units 13a and 13b, which are arc-shaped portions divided in the circumferential direction, respectively. The front torso part 12 is formed of a pair of front torso joint flanges that protrude from the front torso units 12a and 12b inward in the radial direction of the front torso part 12 along the dividing plane Pa. 23a and 23b are overlapped, and main welding 30 is applied to the joining corner portion 24 at the outer peripheral end surface portion of the pair of front trunk joining flanges 23a and 23b inside the front trunk portion 12 (FIGS. 10A to 10C). The joint corners 24 at the outer peripheral end surfaces of the pair of front barrel joint flanges 23a, 23b to which the joint strength necessary for the joint integration is maintained and the main welding 30 is applied, The body portion 12 is disassembled into a plurality (two) of front body units 12a and 12b.

  Further, in the present embodiment, as shown in FIG. 1, middle barrel units 14 a and 14 b that are arc-shaped portions divided into two in the circumferential direction are formed between the front barrel portion 12 and the rear barrel portion 13 by the main welding 30. The middle-folded middle barrel portion 14 is configured by joining and integrating, and the middle-folded middle barrel portion 14 includes each middle-trunk unit along the dividing plane Pc, as shown in FIGS. 4 (a) and 4 (b). A pair of middle cylinder joint flanges 25a and 25b provided so as to project radially inward from the middle folded body part 14 from 14a and 14b are overlapped, and a pair of middle body joint flanges are provided inside the middle folded middle part 14 By applying the main welding 30 to the joint corners 26 at the outer peripheral end surfaces of 25a and 25b (see FIG. 11), the joining strength necessary for joint integration is maintained, and a pair of the main welding 30 is applied. Outer peripheral end surfaces of the middle-body flanges 25a and 25b By cutting the joint angle portion 26 definitive, so that the seat back tilting in the barrel portion 14 is intermediate trunk units 14a of the plurality (two), it is dismantled 14b.

  Further, in the present embodiment, seal welding 27 is applied to the outer peripheral surfaces of the front barrel portion 12 and the middle folded middle barrel portion 14 along the division surfaces Pa and Pc to fill the gaps between the division surfaces Pa and Pc. (See FIGS. 10 to 11).

  Furthermore, in the present embodiment, the front trunk joining flanges 23a and 23b provided to project radially inward from the front trunk units 12a and 12b along the dividing surface Pa of the front trunk 12 respectively. The barrier rib 22 and the holding holder (drive device holder) 28 of the cutter drive device 16 are integrally joined.

  In the present embodiment, the mud pressure shield excavator 11 that has reached the reach shaft is disassembled and removed before disassembling the skin plate 10. That is, for example, the rotary cutter 15 shown in FIG. 5 is disassembled into two cutter units 15a and 15b and disassembled by a dividing surface Pd that is shifted from the center to one side. Further, the cutter driving device 16 shown in FIG. 6 is removed from the driving device holder 28 (see FIG. 1) provided surrounding the center mounting opening 22a formed in the central portion of the partition wall 22 and disassembled. . Furthermore, the soil removal mechanism 17 shown in FIG. 7 is removed from the lower mounting opening 29 (see FIG. 1) formed in the lower part of the partition wall 22 and disassembled. Furthermore, the erector apparatus 20 shown in FIG. 8 is disassembled into two erector units 20a and 20b and disassembled by a split surface Pe formed by bolting provided at the upper part.

  And in this embodiment, the front trunk | drum 12 cuts the joining corner | angular part 24 in the outer peripheral end surface part of a pair of joining flange 23a, 23b to which this welding 30 was given, and the front trunk | drum 12 has multiple (2 The middle folded middle barrel portion 14 is joined at the outer peripheral end surface portions of the pair of middle barrel joining flanges 25a, 25b to which the main welding 30 is applied. By cutting the portion 26, the plurality of (two) middle body units 14a and 14b are disassembled.

  That is, in this embodiment, as shown in FIGS. 9 and 10 (a) to 10 (c), the joining flanges 23a and 23b of the front body portion 12 are made of, for example, a metal plate having a thickness of about 40 mm, and have the same thickness. It is firmly bonded and fixed to the front body portion 12 and the partition wall 22 made of a metal plate having a length of about 40 mm by welding or the like. The joining flanges 23a and 23b are attached from the inner side surface of the front body portion 12 to the inner side surface of the partition wall 22 so that the planar shape along the dividing surface Pa is substantially L-shaped, and the substantially L-shaped radial direction. An annular driving device holder 28 surrounding the center mounting opening 22a of the partition wall 22 is joined to the inner end portion. Therefore, in the present embodiment, the joining flanges 23 a and 23 b are joined integrally from the front trunk units 12 a and 12 b across the partition wall 22 and the drive device holder 28. This effectively reinforces the fixed state of the partition wall 22 and the drive device holder 28 with respect to the front body units 12a and 12b, which are the main body portions of the front body part 12. The partition wall 22 and the drive device holder 28 are divided in the same manner as the front body portion 12, and are carried into the shield construction site while being joined to the front body units 12a and 12b in a factory or the like.

  And in this embodiment, while overlapping a pair of front trunk joining flanges 23a and 23b which each project radially inward from the upper and lower front trunk units 12a and 12b, A main weld 30 having a groove depth of, for example, about 25 mm is required at the joining corner 24 in the outer peripheral end face including the joining portion with the driving device holder 28 excluding the joining portion between the front body portion 12 and the partition wall 22. By applying with a welding length sufficient to ensure a sufficient joining strength, the front body portion 12 is formed in which the front body units 12a and 12b are joined and integrated in a strong and stable state. Further, by cutting the main weld 30 applied to the outer peripheral end surface portion by gas cutting or the like, the front body portion 12 is easily disassembled into the upper and lower front body units 12a and 12b.

  Further, in the present embodiment, simple sealing is performed on the outer peripheral surface of the front body portion 12 and the outer surface of the partition wall 22 for the purpose of filling the gap between the divided surfaces Pa along the divided surface Pa. The weld 27 is applied with a groove depth of about 6 mm, for example. The seal weld 27 is also easily cut without causing distortion in the front body portion 12 by gas cutting or the like, so that the front body portion 12 is easily disassembled into the upper and lower front body units 12a and 12b. It will be.

  Furthermore, in the present embodiment, the pair of front cylinder joint flanges 23a and 23b are provided with alignment holes 31, respectively. By inserting an alignment pin into the alignment holes 31, for example, a pair of front cylinders After the joining flanges 23a and 23b are aligned, the main welding 30 is applied to the joining corner portion 24 at the outer peripheral end face portion.

  Furthermore, in the present embodiment, a plurality of bolt fastening holes 32 are provided in each of the pair of front trunk joining flanges 23a and 23b, and these bolt fastening holes 32 are aligned to connect the joining bolts 33. By tightening, the pair of front trunk joint flanges 23a and 23b, which are overlapped in a stronger and stable state, can be joined. These joining bolts 33 can be easily released from the joining state of the front trunk joining flanges 23a and 23b by being removed or cut when the front trunk 12 is disassembled.

  On the other hand, as shown in FIGS. 9 and 11, the middle-joint flanges 25 a and 25 b of the middle folded middle body portion 14 are made of, for example, a metal plate having a thickness of about 40 mm. From the inner surface of the attached sliding ring plate 34 to the inner surface of the middle folded middle body portion 14, it is arranged along the dividing surface Pc so as to have a substantially rectangular planar shape with one corner portion cut obliquely. It is firmly joined and fixed by welding or the like.

  In this embodiment, a pair of middle cylinder joint flanges 25a and 25b projecting radially inward from the upper and lower middle cylinder units 14a and 14b are overlapped, and the outer circumferences of the overlapped middle cylinder joint flanges 25a and 25b are overlapped. By applying the main welding 30 having a groove depth of, for example, about 25 mm to the joining corner portion 26 at the end face portion with a welding length sufficient to ensure the necessary joining strength, the inner cylinder units 14a and 14b are strengthened. Further, the middle folded middle body portion 14 is formed which is joined and integrated in a stable state. Further, by cutting the main weld 30 applied to the outer peripheral end surface portion by gas cutting or the like, the middle folded middle barrel portion 14 is easily disassembled into the upper and lower middle barrel units 14a and 14b.

  In the present embodiment, the outer peripheral surfaces of the folded middle barrel portion 14 and the sliding ring plate 34 are simply performed for the purpose of filling the gap between the divided surfaces Pc along the divided surface Pc. The seal weld 27 is applied with a groove depth of about 6 mm, for example. This seal weld 27 is also easily cut without causing distortion in the middle folded middle portion 14 by gas cutting or the like, so that the middle folded middle portion 14 can be easily formed into the upper and lower middle barrel units 14a and 14b. Will be demolished.

  Furthermore, in this embodiment, the pair of middle cylinder joint flanges 25a and 25b are each provided with an alignment hole 31. By inserting an alignment pin, for example, into the alignment hole 31, a pair of middle cylinders are provided. After the joining flanges 25a and 25b are aligned, the main welding 30 is applied to the joining corner part 26 at the outer peripheral end face part.

  Furthermore, in this embodiment, a plurality of bolt fastening holes 32 are provided in each of the pair of middle body joining flanges 25a and 25b, and these bolt fastening holes 32 are aligned to connect the joining bolts 33. By tightening, the pair of middle cylinder joint flanges 25a and 25b, which are overlapped in a stronger and stable state, can be joined. These joining bolts 33 can be easily released from the joining state of the middle body joining flanges 25a and 25b by being removed or cut when the middle folded middle body part 14 is disassembled.

  In the present embodiment, the rear body portion 13 is a portion where the segments are assembled inside, and even when the rear body portion 13 is cut directly by gas fusing or the like and distortion due to high heat or the like occurs, the accuracy is much higher at the time of rejoining. If the joint flange is provided so as to protrude radially inward from the rear body portion 13, it is an obstacle to assembling the segments. Therefore, as shown in FIGS. 3 (a), 3 (b) and 12, the rear body unit 13a, 13b divided up and down by the dividing surface Pb is provided with a joining flange. In the same manner as in the conventional general method, the groove depth is about 25 mm, for example, at the inner corner along the dividing surface Pb in a state where these ends are abutted directly with the rear trunk portion 13. The main welding 35 is performed, and the outer corners along the dividing surface Pb are subjected to seal welding 36 having a groove depth of, for example, about 6 mm to join and integrate the rear trunk units 13a and 13b. Further, when the skin plate 10 is disassembled, the main body 35 and the seal weld 36 are cut by gas cutting or the like so that the rear body portion 13 is easily separated and disassembled into the upper and lower rear body units 13a and 13b. .

  Further, in the present embodiment, as shown in FIGS. 9 and 13, the middle folded middle barrel portion 14 and the rear trunk portion 13 are circumferentially aligned along the axially divided surface Pf with their end portions abutted against each other. Are joined and integrated in the axial direction of the tunnel by a main welding 37 having an inner corner groove depth of, for example, about 25 mm and a seal weld 38 having an outer corner groove depth of, for example, about 6 mm. ing. Further, when the skin plate 10 is disassembled, the main welding portion 37 and the seal welding portion 38 are cut by gas cutting or the like, so that the middle folded body portion 14 and the rear body portion 13 are easily separated and disassembled.

  And according to skin plate 10 of divertable shield excavator 11 of this embodiment provided with the above-mentioned composition, joining strength in a part to be divided is sufficiently secured by joining by main welding 30, 35, 37. In addition, the joining portion is cut while avoiding the occurrence of distortion even at the divided portions along the dividing surfaces Pa and Pc in the front barrel portion 12 and the middle folded middle barrel portion 14 that require particularly high joining accuracy. Can be easily dismantled.

  That is, according to the present embodiment, the front trunk portion 12 and the middle folded middle barrel portion 14 are respectively radially inward from the front trunk units 12a and 12b and the middle trunk units 14a and 14b along the dividing surfaces Pa and Pc. A pair of projecting front body joint flanges 23a and 23b and middle body joint flanges 25a and 25b are overlapped, and the joint corners 24 at the outer peripheral end surfaces are inside the front body part 12 and the middle folded body part 14. , 26 is subjected to main welding 30, so that the main welding 30 applied at a predetermined thickness, length, and groove depth is joined at a portion away from the front body portion 12 and the middle folded middle portion 14. Sufficient bonding strength required for integration is maintained, and sufficient bonding strength that can resist a large earth pressure or water pressure is obtained. Further, by cutting the joint corners 24 and 26 at the outer peripheral end surfaces of the pair of front barrel joint flanges 23a and 23b and the middle barrel joint flanges 25a and 25b to which the main welding 30 has been applied, the front trunk portion 12 is cut. Since the cutting operation is performed at a position that is considerably away from the middle folded middle barrel portion 14, the front barrel portion 12 and the middle folded middle barrel portion 14 are distorted by high heat during cutting when the skin plate 10 is disassembled. It is possible to effectively avoid the occurrence.

  Therefore, according to the divertable skin plate 10 of the present embodiment, the assembly work and the disassembly work can be easily performed without requiring much labor, and the joint portion is joined by the main welding so that a large earth pressure is obtained. And can be integrated through a joint that has sufficient strength to withstand water pressure, and can be efficiently recovered and reused to easily reduce equipment costs during shield construction. It becomes possible.

  The present invention is not limited to the above-described embodiment, and various modifications can be made. For example, the skin plate of the present invention can be used as an outer shell of other shield excavators other than the mud pressure shield excavator. In addition, the front trunk part, the rear trunk part, or the middle folded middle trunk part does not necessarily have to be divided into two vertically along a horizontal or substantially horizontal dividing surface, and is not necessarily divided into vertical or oblique dividing surfaces. It may be divided along or divided into three or more arc-shaped portions. Furthermore, the skin plate which consists of a front trunk | drum and a rear trunk | drum which is not provided with a middle folding middle trunk | drum can also be comprised.

It is a top view explaining the structure of the shield excavator in which the skin plate which concerns on preferable one Embodiment of this invention is used. The structure of the front trunk | drum part divided | segmented along a division surface is demonstrated, (a) is a front view, (b) is sectional drawing. The structure of the rear trunk | drum divided | segmented along a division surface is demonstrated, (a) is a front view, (b) is sectional drawing. FIG. 3A is a front view and FIG. 2B is a cross-sectional view illustrating a configuration of a middle folded middle body portion that is divided along a dividing surface. It is a front view of the rotation cutter disassembled from the shield excavator. It is a side view of the cutter drive device disassembled from the shield excavator. It is a side view of the soil removal mechanism disassembled from the shield excavator. It is a front view of the erector apparatus disassembled from the shield excavator. It is a schematic plan view which cuts out and shows a part of shield excavator explaining the structure of the junction part of a skin plate. The structure of the joint portion of the skin plate will be described. (A) is an enlarged cross-sectional view along DD in FIG. 9, (b) is an enlarged cross-sectional view along EE in FIG. 9, and (c) is a diagram. It is an expanded sectional view in alignment with FF of 9. It is an expanded sectional view along GG of FIG. 9 explaining the structure of the junction part of a skin plate. It is an expanded sectional view in alignment with HH of FIG. 9 explaining the structure of the junction part of a skin plate. It is the A section expanded sectional view of Drawing 9 explaining the composition of the joined part of a skin plate.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Skin plate 11 Mud pressure shield excavator 12 Front trunk | drum 12a, 12b Front trunk | drum unit 13 Rear trunk | drum 13a, 13b Rear trunk | drum unit 14 Middle folding middle trunk | drum 14a, 14b Middle trunk | drum unit 15 Rotary cutter 16 Cutter drive device 22 Bulkhead 23a, 23b Front barrel joint flange 24 Joint corner portions 25a, 25b at the outer peripheral end face portion of the front trunk joint flange Middle barrel joint flange 26 Joint corner portions 27, 36, 38 at the outer end face portion of the middle trunk flange Seal welding 28 Drive device Holder 30, 35, 37 Main welding 31 Positioning hole 32 Bolt fastening hole 33 Joining bolt 34 Sliding ring plate Pa, Pb, Pc Dividing surface Pf Axial dividing surface

Claims (6)

In the other shield construction site, a rotary cutter is provided at the tip, and includes a front trunk portion in which a partition wall and a cutter driving device are provided on the inner side, and a rear trunk portion in which segments are assembled on the inner side. A divertable shield excavator skin plate,
Each of the front body part and the rear body part is configured by joining and integrating a plurality of arc-shaped parts divided in the circumferential direction by main welding,
The front torso overlaps a pair of joint flanges provided so as to protrude radially inward of the front torso from each arcuate portion along the dividing surface, and the pair of joints are formed inside the front torso. Bonding at the outer peripheral end surface portions of the pair of joint flanges to which the main welding is performed is achieved by performing main welding at the bonding corners at the outer peripheral end surface portions of the flanges, and maintaining the bonding strength. A divertable shield excavator skin plate, wherein the front body portion is disassembled into a plurality of arc-shaped portions by cutting a corner portion.   It includes a middle folded middle barrel constituted by joining and integrating a plurality of arc-shaped portions divided in the circumferential direction between the front trunk portion and the rear trunk portion by main welding. The portion overlaps a pair of joint flanges provided so as to protrude radially inward of the middle folded middle barrel portion from each arcuate portion along the dividing surface, and the pair of joint flanges are disposed inside the middle folded middle barrel portion. By performing the main welding at the joint corners on the outer peripheral end surface of the joint flange, the joint strength necessary for joint integration is maintained, and at the outer peripheral end surfaces of the pair of joint flanges subjected to the main welding. The divertable shield excavator skin plate according to claim 1, wherein the middle bent middle part is disassembled into a plurality of arc-shaped parts by cutting a joint corner.   Each of the pair of joining flanges is provided with an alignment hole, and the pair of joining flanges are aligned via the alignment hole, and the main welding is performed at the joining corner portion at the outer peripheral end surface portion. The skin plate of the divertable shield excavator according to claim 1 or 2.   4. The diversion according to claim 1, wherein each of the pair of joint flanges is provided with a plurality of bolt fastening holes, and the joint bolts are fastened by aligning the bolt fastening holes. 5. A skin plate for a shield excavator.   The seal welding which fills the clearance gap between the said division surfaces is given to the outer peripheral surface of the said front trunk | drum and / or the said middle folding middle trunk | drum along the said division | segmentation surface. Convertible shield excavator skin plate.   6. A joining flange provided so as to project radially inward from each arcuate portion along the dividing surface of the front body portion is integrally joined to the partition wall and a holding holder of the cutter driving device. The skin plate of the divertable shield excavator in any one of.

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