JPH0949390A - Pit mouth sealing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily expand the tip of a rocking backing plate by fitting an elastic seal member so that an part periphery part is brought into slidable contact with the outer peripheral face of a conduit forming body or a leading apparatus, and tightening a protruded piece tightening wire. SOLUTION: The gap between the outer peripheral face of a conduit forming body 7 or a leading apparatus 6 and a pit mouth sealing device is sealed. An elastic seal member 14 is provided so that the inner periphery section of the pit mouth sealing device is brought into slide contact with the outer peripheral face of the conduit forming body 7 or the leading apparatus 6. A rocking backing plate 18 supporting the back face of the elastic seal member 14 is expanded to an excavated pit side until the tip is separated from the outer periphery of the leading apparatus 6 and rockably fitted. The rocking backing plate 18 is rockably fitted to a fixed plate via a hinge part 19. When a protruded piece tightening wire 22 is tightened, the tip of the outside or inside rocking backing plate 18 is easily expanded.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wellhead sealing device installed at a wellhead, and more specifically, to a tunnel provided in an inner surface of the wellhead and an excavation hole formed in the ground by communicating with the wellhead. The present invention relates to a wellhead sealing device that seals between an outer peripheral surface of a pipe forming member such as a segment or a buried pipe, or a leading machine such as a shield machine or a blade pipe provided at the tip thereof.

[0002]

2. Description of the Related Art Conventionally, a wellhead formed on the wall of a tunnel or a tunnel well whose inner surface has been completely lined, or a wellhead formed on the surface of the ground, has an inner peripheral surface of the well and, for example, a shield construction method. Between the outer peripheral surface of a leading device such as a shield machine used in a shield machine or a propulsion method or the outer peripheral surface of a conduit forming body such as a tunnel segment or a buried pipe that is continuously provided behind the leading device. A wellhead sealing device for sealing the For example, Japanese Examined Patent Publication No. 3-3797 discloses a wellhead sealing device provided at a launching side entrance (starting entrance) of a shield machine of a vertical shaft.
Japanese Patent No. 0392 discloses a wellhead sealing device provided at a shield excavator starting side entrance (starting mouth) or a shield excavator reaching side entrance (arrival opening) of a vertical shaft.

The starting port sealing device disclosed in the above publication is an elastic device which is attached to the starting port of a vertical shaft to seal between the inner peripheral surface of the starting port and the outer peripheral surface of the shield machine or tunnel segment. A plurality of swing backing plates arranged along the side surface of the seal member and the elastic seal member on the inner side of the vertical shaft, and swingably attached to the wellhead such that the tip is expanded to the outer side of the vertical shaft. It has and. This rocking backing plate has its tip abutted against the outer peripheral surface of the shield machine or tunnel segment due to expansion toward the excavation pit side so that it is between the inner peripheral surface of the wellhead and the outer peripheral surface of the shield machine or tunnel segment. Since the back surface of the elastic seal member is supported by, the elastic seal member can be pressure-resistant supported against pressure such as earth pressure and water pressure on the excavation pit side.

On the other hand, the sealing device for the access port disclosed in the above publication is attached to the access port of the vertical shaft to seal between the inner peripheral surface of the access port and the outer peripheral surface of the shield machine or tunnel segment. Elastic seal member, and a plurality of swings disposed along the side surface of the elastic seal member on the inner side of the vertical shaft and swingably attached to the wellhead so that the tip end is expanded to the inner side of the vertical shaft. And a backing plate.
Since this swing backing plate expands to the inside of the shaft, it cannot support the elastic seal member by itself against the pressure on the side of the excavation shaft. For this reason, in this kind of access port sealing device, a tightening wire for reducing the diameter of the swinging backing plate and pressing the tip of the swinging backing plate against the outer peripheral surface of the shield machine or tunnel segment through the elastic sealing member. Is wound.

[0005]

In general, a plurality of cutting blades called bits are radially provided on the peripheral edge of the tip of a shield machine. Further, in general, a step is provided between the tail portion of the shield machine and the outer peripheral surface of the tunnel segment, and the tail portion of the shield machine is slidably contacted with the outer surface of the tunnel segment to shield the shield machine and the outer surface of the segment. A wire-brush-like sealing means for sealing the gap between and is provided. Further, generally, in the propulsion method, the tip conduit provided at the tip of the buried pipe propelled by the propulsion device has an outer diameter slightly larger than that of the buried pipe, and also has a tapered sharp tip.

Therefore, the above-described conventional wellhead sealing device for a starting opening has the following problems.

(1) When the rocking backing plate is pressed by the peripheral edge of the tip end of the shield machine to expand the tip of the rocking backing plate, a cut provided on the peripheral edge of the tip end of the shield machine. The blade may come into contact with the rocking backing plate or the elastic sealing member and damage the cutting blade, the rocking backing plate or the elastic sealing member. Also in the propulsion method, the elastic seal member may be damaged by the blade pipe at the tip of the buried pipe that is propelled, and the sealing performance may be deteriorated.

(2) While the tip of the rocking backing plate is transferred from the outer circumference of the tail portion of the shield machine to the outer peripheral surface of the tunnel segment, the tip of the rocking backing plate is provided in the tail portion of the shield machine. There is a risk that the wire brush-shaped sealing means may come into contact with the existing wire-brush-shaped sealing means, causing an inconvenient deformation of the wire-brush-shaped sealing means to deteriorate the sealing function.

Further, in the above-described conventional wellhead sealing device for the entrance, the following problems occur.

(1) Since the pressure on the side of the digging hole that acts on the elastic seal member acts in the direction of expanding the inner peripheral portion of the elastic seal member and the tip of the swing backing plate, the elastic seal member is placed on the side of the digging pit. In order to support the rocking backing plate against pressure, it is necessary to strongly tighten the rocking backing plate with the tightening wire.
It is difficult to secure sufficient pressure resistance.

(2) When the elastic seal member is pressed by the peripheral edge of the tip of the shield machine to expand the inner peripheral part of the elastic seal member together with the tip of the swing backing plate, the peripheral edge of the tip of the shield machine. There is a possibility that the cutting edge protruding from the blade may contact the elastic seal member and damage the elastic seal member. Also in the propulsion method, the elastic seal member may be damaged by the blade pipe at the tip of the buried pipe that is propelled, and the sealing performance may be deteriorated.

Therefore, the object of the present invention is applicable to both the starting side and the reaching side of a leading equipment such as a shield machine or a blade for a propulsion method, and in a leading equipment or a well-sealing device. It is an object of the present invention to provide a wellhead sealing device which can prevent damage to its constituent parts and which is excellent in pressure tight sealing.

[0013]

In order to solve the above-mentioned problems, the invention according to claim 1 is a pipe forming body which is arranged in an excavation pit which is formed by excavation in the ground by communicating with the pit and the pit. Or a wellhead sealing device for sealing between the tip and the outer peripheral surface of the leading equipment, wherein an elastic seal attached to the wellhead such that the inner peripheral portion thereof is in sliding contact with the outer peripheral surface of the pipe forming body or the leading equipment. A member and a side surface of the elastic seal member opposite to the side surface on the digging pit side, and is swingably attached to the wellhead such that the tip is expanded to the digging pit side. The tip end abuts the outer peripheral surface of the duct forming body by expanding to the pit side, and supports the back surface of the elastic seal member between the inner peripheral surface of the pit mouth and the outer peripheral surface of the leading device or the duct forming body. A plurality of rocking backing plates, and the tip of the rocking backing plate is attached to the leading device. Providing wellhead sealing device being characterized in that a backing plate widening means for widening to a position away from the periphery.

In the wellhead sealing device having the above-mentioned structure, the pressure on the side of the excavated wellhole is elastic even when it is provided at the wellhead on the starting side of the leading device or at the wellhead on the arrival side. Since the inner peripheral portion of the seal member and the tip of the rocking backing plate act in a direction of reducing the diameter, the elastic sealing member can be firmly pressure-resistant supported by the rocking backing plate against the pressure on the digging side. it can.

Further, when the wellhead sealing device is provided at the wellhead on the starting side of the leading equipment, when the leading equipment starts from the wellhead, the tip end of the rocking backing plate is elastically sealed by the backing plate expanding means in advance. Since it can be expanded together with it, it is possible to prevent the tip end portion of the leading device from coming into contact with the swing backing plate or the elastic seal member. Also, in the case of the shield construction method, when the tip of the swing backing plate moves from the outer periphery of the tail portion of the shield machine to the outer peripheral surface of the tunnel segment,
Since the tip of the rocking backing plate can be maintained at a required expansion degree by the backing plate expanding means, the tip of the rocking backing plate is shaped like a wire brush provided on the tail portion of the shield machine. It is possible to prevent contact with the sealing means.

On the other hand, when the wellhead seal device is provided at the wellhead on the arrival side of the leading equipment, when the leading equipment reaches the wellhead, the tip end of the swinging backing plate together with the elastic seal member is expanded beforehand with the backing plate expanding means. Thus, the leading device can be expanded in the direction opposite to the forward direction, so that the tip of the leading device can be prevented from coming into contact with the elastic seal member or the swing backing plate.

Therefore, a wellhead seal device which can be applied to both the starting side entrance and the reaching side entrance of the leading equipment and which can prevent damage to the components of the leading equipment or the wellhead sealing device and which is excellent in pressure-proof sealing property. Can be provided.

According to a second aspect of the present invention, in the wellhead sealing device according to the first aspect, each of the swing backing plates is swingably attached to a fixed plate fixed to the wellhead via a hinge portion. The backing plate expanding means is connected to the projecting piece and a projecting piece provided on each swinging backing plate and extending in a direction opposite to the tip of the swinging backing plate with respect to the hinge portion. The projecting piece tightening wire is provided, and the tip of the swing backing plate is expanded by tightening the projecting piece tightening wire.

According to the above structure, the tip of the swing backing plate can be easily opened by tightening the protruding piece tightening wire connected to the protruding piece.

According to a third aspect of the present invention, in the wellhead seal device according to the first aspect, there is further provided a seal member expanding means for expanding the inner peripheral portion of the elastic seal member.

According to the above construction, the inner peripheral portion of the elastic seal member can be expanded by the seal member expansion means when necessary or can be maintained at a required expansion degree, so that the leading device or the swing back. When the inner peripheral portion of the elastic seal member is expanded by the plate, the expanding operation of the inner peripheral portion of the elastic seal member can be assisted by the seal member expanding means. Therefore, even in the case of an elastic seal member that is attached to a non-circular wellhead such as a rectangular shape or a laterally rounded shape, it is possible to easily expand a portion that is difficult to expand with only the leading device.

According to a fourth aspect of the invention, in the wellhead seal device according to the third aspect, the seal member expanding means is circumferentially arranged on an inner peripheral surface of the wellhole and an inner peripheral portion of the elastic seal member. A plurality of through rings provided, a seal member expanding wire alternately inserted through the through rings provided on the inner peripheral surface of the wellhead and the through rings provided on the inner peripheral portion of the elastic seal member. And the inner peripheral portion of the elastic seal member is expanded by tightening the seal member expanding wire.

According to the above construction, the seal member expanding wire, which is alternately inserted between the through ring provided on the inner peripheral surface of the wellhead and the through ring provided on the inner peripheral portion of the elastic seal member, is tightened. As a result, the inner peripheral portion of the elastic seal member can be easily expanded.

According to a fifth aspect of the present invention, in the wellhead sealing device according to the fourth aspect, the seal member expanding wire is guided to the wellhead from the inside of the wellhole to the outside of the wellhead on the side opposite to the excavation well. Is provided with a wire guiding means.

According to the above construction, since the seal member expanding wire can be guided from the inside of the pit through the wire guiding means to the outside of the pit on the side opposite to the excavation pit, the elastic seal member is expanded. The tightening operation of the seal member expanding wire can be easily performed in the working space outside the wellhead on the side opposite to the excavation well.

Further, the invention according to claim 6 is between the wellhead and the outer peripheral surface of the pipe forming body or the tip end of the conduit forming body arranged in the excavation well formed by excavating and forming in the ground in communication with the wellhead. A wellhead sealing device that seals a hole, is arranged in the wellhead with an interval in the direction of drilling the wellhole, and an inner peripheral portion is in sliding contact with an outer peripheral surface of the pipe forming body or the leading device. The outer and inner elastic seal members attached to the wellhead and along the side surface of the outer elastic seal member on the side of the excavation hole, and the tip is expanded to the side opposite to the excavation hole. It is swingably attached to the wellhead, and the tip comes into contact with the outer peripheral surface of the leading equipment or pipe forming body by expanding toward the side opposite to the digging pit, and the inner peripheral surface of the wellhead and the leading equipment or pipe. Between the outer peripheral surface of the path forming body and the digging pit side of the outer elastic seal member A plurality of outer rocking backing plates that support the surface and the inner elastic seal member are arranged along a side surface of the inner elastic seal member opposite to the side surface on the side of the excavation hole, and the tip is expanded to the side of the excavation hole. Is swingably attached to the wellhead, and the tip is brought into contact with the outer peripheral surface of the leading equipment or conduit forming body by expanding toward the digging pit side, and the inner peripheral surface of the wellhead and the leading equipment or conduit forming A plurality of inner swing backing plates that support a side surface of the inner elastic seal member opposite to the side surface on the digging pit side with the outer peripheral surface of the body, and tips of the outer and inner swing backing plates. An outer and inner backing plate expanding means for expanding each of them to a position spaced apart from the outer periphery of the leading device is provided.

The wellhead seal device having the above-described structure has elastic seals on the outer side and the inner side when necessary, whether it is provided at the wellhead on the starting side of the leading equipment or at the wellhead on the arrival side of the leading equipment. The inside of the airtight space defined by the member and the inner peripheral surface of the wellhead and the outer peripheral surface of the leading equipment or pipe forming body is set to a pressure higher than the external pressure on the side of the excavation hole and the external pressure on the side opposite to the excavation hole. By doing so, the outer and inner elastic seal members can be firmly pressure-resistant supported by the outer and inner swing backing plates.

Further, since the tips of the outer and inner rocking backing plates can be spread by the backing plate spreading means together with the outer and inner elastic seal members when necessary, the leading end of the leading device is placed outside or It is possible to prevent contact with the inner swinging backing plate and the outer or inner elastic seal member.
Also, in the case of the shield construction method, when the tip of the rocking backing plate is transferred from the outer periphery of the tail part of the shield machine to the outer peripheral surface of the tunnel segment at the time of starting, the tip of the outer or inner rocking backing plate is Since the required expansion can be maintained by the outer or inner backing plate expanding means, the tip of the outer or inner rocking backing plate has a wire brush-like shape provided in the tail portion of the shield machine. It is possible to prevent contact with the sealing means.

Therefore, the wellhead seal which can be applied to both the starting side entrance and the reaching side entrance of the leading equipment, can prevent damage to the components of the leading equipment or the wellhead sealing device, and can enhance the pressure tight sealing property. A device can be provided.

According to a seventh aspect of the present invention, in the wellhead sealing device according to the sixth aspect, each of the outer and inner swing backing plates is swingable to a fixed plate fixed to the wellhole via a hinge portion. And the outer and inner backing plate expanding means are provided on each of the swinging backing plates and extend toward the hinge portion in a direction opposite to the tip of the swinging backing plate. And a projecting piece tightening wire connected to the projecting piece, so that the tips of the outer and inner swing backing plates are expanded by tightening the outer and inner projecting piece tightening wires. It is characterized by having done.

According to the above construction, the tip of the outer or inner swing backing plate can be easily opened by tightening the outer or inner protruding piece tightening wire connected to the protruding piece.

The invention according to claim 8 is the wellhead sealing device according to claim 7, wherein the outer protruding piece tightening wire is provided in the wellhead from the inside of the wellhead to the outside of the wellhead on the side opposite to the drilling well. It is characterized in that a wire guide means for guiding is provided.

According to the above construction, the outside protruding piece tightening wire can be guided from the inside of the well through the wire guiding means to the outside of the well on the side opposite to the digging pit. The tightening operation of the outer protruding piece tightening wire for expanding can be easily performed in the work space outside the wellhead on the side opposite to the pit.

Further, the invention according to claim 9 is between the wellhead and the outer peripheral surface of the pipe forming body or the tip end of the conduit forming body arranged in the excavation well formed in the ground by communicating with the wellhead. A wellhead sealing device for sealing the inner hollow portion of the elastic seal member having an internal hollow structure attached to the wellhole such that an inner peripheral portion thereof is in sliding contact with the outer peripheral surface of the conduit forming body or the leading device. Arranged along the side of the mine shaft side,
Also, the tip is swingably attached to the well so that the tip is opened to the side opposite to the digging pit, and the tip is expanded to the side opposite to the digging pit so that the tip is the outer periphery of the leading device or the conduit forming body. A plurality of outer rocking backing plates that abut the surface and support the side surface of the elastic seal member on the excavation pit side between the inner peripheral surface of the wellhead and the outer peripheral surface of the leading device or the conduit forming body, The elastic seal member is disposed along a side surface opposite to the side surface on the digging pit side, and is swingably attached to the mine mouth so that the tip is expanded to the digging pit side, and is attached to the digging pit side. Of the elastic seal member between the inner peripheral surface of the wellhead and the outer peripheral surface of the leading device or the conduit forming member by contacting the outer peripheral surface of the leading device or the conduit forming member by the expansion of A plurality of inner rocking backing plates supporting a side surface opposite to the side surface, and the outer and inner rocking backing plates. Providing wellhead seal device characterized by comprising an outer and inner backing plate spreader means is expanded end to a position away from the outer periphery of each lead instrument.

In the wellhead seal device having the above-described structure, the inside of the elastic seal member is not required when the well is installed at the wellhead on the starting side of the leading equipment or at the wellhead on the arrival side of the leading equipment. By setting the pressure higher than the external pressure on the side of the pit and the external pressure on the side opposite to the pit, the elastic seal member is strongly pressure-resistant supported by the outer and inner swing backing plates against these external pressures. It becomes possible to do.

Further, since the tips of the outer and inner rocking backing plates can be expanded together with the inner peripheral portion of the elastic seal member by the outer and inner backing plate expanding means when necessary, the leading end of the leading device can be obtained. Can be prevented from contacting the outer or inner swing backing plate and the elastic seal member. Also, in the case of the shield construction method, when the tip of the rocking backing plate is transferred from the outer periphery of the tail part of the shield machine to the outer peripheral surface of the tunnel segment at the time of starting, the tip of the outer or inner rocking backing plate is Since the required expansion can be maintained by the outer or inner backing plate expanding means, the tip of the outer or inner rocking backing plate has a wire brush-like shape provided in the tail portion of the shield machine. It is possible to prevent contact with the sealing means.

Therefore, the wellhead seal can be applied to both the starting-side wellhead and the reaching-side wellhead of the leading equipment, can prevent damage to the components of the leading equipment or the wellhead sealing device, and can enhance the pressure-proof sealing property. A device can be provided.

According to a tenth aspect of the present invention, in the wellhead sealing device according to the ninth aspect, the outer and inner swing backing plates are swingable through a hinge portion to a fixed plate fixed to the wellhead, respectively. And the outer and inner backing plate expanding means are provided on each of the swinging backing plates and extend toward the hinge portion in a direction opposite to the tip of the swinging backing plate. And a projecting piece tightening wire connected to the projecting piece, so that the tips of the outer and inner swing backing plates are expanded by tightening the outer and inner projecting piece tightening wires. It is characterized by having done.

According to the above structure, the tip of the outer or inner swing backing plate can be easily opened by tightening the outer or inner protruding piece tightening wire connected to the protruding piece.

The invention according to claim 11 is the wellhead sealing device according to claim 9, wherein the outer protruding piece tightening wire is provided in the wellhead from the inside of the wellhead to the outside of the wellhead on the side opposite to the drilling well. It is characterized in that a wire guide means for guiding is provided.

According to the above structure, the outer protruding piece tightening wire can be guided from the inside of the wellhead to the outside of the wellhead on the side opposite to the digging pit through the wire guide means, so that the outer rocking backing plate is provided. It is possible to easily perform the tightening operation of the protruding piece tightening wire on the outer side for expanding the opening in the work space outside the wellhead on the side opposite to the digging pit.

[0042]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings.

FIGS. 1 to 3 show a first embodiment of a wellhead sealing device when the present invention is applied to a wellhead on the starting side of a shield machine of a vertical shaft. 1 is a longitudinal sectional view of a main part of the wellhead sealing device, FIG. 2 is a perspective view showing an example of a hinge connection configuration of a swing backing plate and a fixed plate used in the wellhead sealing device of FIG. 1, and FIG. FIG. 2 is a side view schematically showing an arrangement state of a swing backing plate and a protruding piece tightening wire in the wellhead seal device of FIG. 1.

First, referring to FIG. 1, a wellhead 2 having a surface coated with a covering plate 3 is formed on a wellhole 2 of a vertical shaft 1, and the wellhead 4 is formed on an outer wall surface and an inner wall surface of the wellwall 2. It is open. Here, the wellhead 4 has a circular cross section corresponding to a cylindrical shield machine. A plurality of anchor bolts 5 projecting from the inner wall surface of the mine wall 2 are embedded around the inner opening end of the mine mouth 4 and arranged at equal intervals in the circumferential direction.

In FIG. 1, reference numeral 6 schematically shows a main part of a shield machine as a leading device that is launched from the wellhead 4, and reference numeral 7 is a pipe line connected to the rear part of the shield machine 6. 1 schematically shows a main part of a tunnel segment as a forming body. The shield machine 6 includes a rotary cutter portion 9 at the tip of the tubular portion 8, and the rotary cutter portion 9 together with a large number of front digging blades 10 protrudes radially outward from the outer shape of the tubular portion 8. (Cutting edge) 11 and the like are provided. With this bit 11, it is possible to excavate a tunnel hole slightly larger than the outer diameter of the tubular portion 8 in the natural ground.

The tubular portion 8 of the shield machine 6 has an outer diameter larger than the outer diameter of the tunnel segment 7, and the tubular portion 7 and the outer peripheral surface of the tunnel segment 7 are formed on the inner surface of the tail portion of the tubular portion 8. A wire brush-like sealing means 12 for sealing the gaps is provided. Generally, this sealing means 1
No. 2 can secure hermeticity by filling grease between the wires. The sealing means 12 obliquely projects rearward from the inner surface of the tubular portion 8 toward the outer peripheral surface of the tunnel segment 7, and a part of the sealing means 12 is in the tubular body 8.
It is generally arranged so that the rear end is exposed to the outside.

The wellhead 4 has a space between the inner peripheral surface of the wellhead 4 and the outer peripheral surface of the shield machine 6 or the tunnel segment 7 disposed in the excavation mine which is communicated with the wellhead 4 and excavated in the ground. An elastic sealing member 14 for sealing is attached. As shown in FIG. 2, the elastic seal member 14 has a circular ring shape, and its inner diameter is equal to that of the tunnel segment 7.
It is set smaller than the outer diameter of. As shown in FIG. 1, the outer peripheral portion of the elastic seal member 14 is a ring-shaped pressing plate 1.
5 and a plurality of fixing plates 16 which will be described later, are fastened and fixed to the inner opening end surface of the wellhead 4 by a nut 17 screwed to the anchor bolt 5. By expanding the inner peripheral side of the elastic seal member 14 to the outside of the vertical shaft, that is, the digging pit side, the inner peripheral part of the elastic seal member 14 can be brought into close contact with the outer peripheral surface of the shield machine 6 or the tunnel segment 7. This allows the inner surface of the wellhead 4 and the shield machine 6
Alternatively, a seal can be formed between the outer peripheral surface of the tunnel segment 7.

As shown in FIGS. 2 and 3, each fixing plate 16
A swing backing plate 18 is connected to the swinging backing plate 18 via a hinge portion 19. The swinging backing plate 18 is arranged radially along the side surface of the elastic seal member 14 on the inner side of the vertical shaft, and swings to the wellhead 4 via the fixing plate 16 so that the tip is expanded to the excavating shaft side. Can be mounted as possible. Then, due to the expansion toward the digging pit side, the tip comes into contact with the outer peripheral surface of the shield machine 6 or the tunnel segment 7, and thereby the inner peripheral surface of the wellhead 4 and the outer peripheral surface of the shield machine 6 or the tunnel segment 7. The back surface of the elastic seal member 14 can be pressure-supported between them.

The elastic seal member 14 for the wellhead 4
The above-described mounting structure of the rocking backing plate 18 is merely an example. For example, when using a fixed plate in an interconnected form as shown in Japanese Patent Laid-Open No. 5-340184 by the present applicant, the pressing plate 15 is It can be omitted. Further, a plurality of swing backing plates 18 may be swingably attached to the ring-shaped or arc-shaped fixed plate 16, and further, it is further disclosed in JP-A-6-1467.
As disclosed in Japanese Patent Publication No. 78, an outer peripheral portion of an elastic seal member is attached to a side surface on an excavation mine side of an annular mounting plate projecting inward from an inner opening end of a wellhead, and a swing backing plate is attached to the mounting plate. It is also possible to directly or indirectly swingably mount. Further, the swing backing plate 18 of the illustrated example is swingably attached to the fixed plate 16 by a hinge portion having a hinge shaft, but the swing backing plate 18 swings by utilizing elastic deformation of the elastic joint plate as the hinge portion. The backing plate may be swingable.

The swing backing plate 18 is provided with a backing plate expanding means 20 which is a feature of the present invention. The backing plate expanding means 20 is for expanding the tip end of the swinging backing plate 18 toward the digging pit side to a position separated from the outer periphery of the shield machine 6. In this embodiment, the backing plate expanding means 20 is
A protruding piece 21 provided on each swing backing plate 18 and extending in a direction opposite to the tip of the swing backing plate 18 with respect to the hinge portion 19;
It has a projecting piece tightening wire 22 which is connected to the projecting piece 21 and is wound around the projecting piece 21, and by tightening the projecting piece tightening wire 22 to reduce the diameter of the projecting piece 21. The tip of the rocking backing plate 18 can be opened to the digging pit side. In the case of a relatively small wellhead sealing device, the projecting piece tightening wire 22 can be manually tightened, but in a large wellhead sealing device, the projecting piece tightening wire 22 can be tightened by, for example, a hydraulic cylinder device. It is preferable to use the power of.

In the illustrated embodiment, as the wire holding means, the through hole 23 for inserting the protruding piece tightening wire 22 is formed in each protruding piece 21, but as the wire holding means,
It suffices that the protruding piece tightening wire 22 can hold the protruding piece tightening wire 22 so that the protruding piece tightening wire 22 does not come off from the protruding piece 21. Therefore, for example, a notch groove, a hook or the like may be provided in the protruding piece 21. Further, the protruding piece tightening wire 22 may be wound around the protruding piece 21 over one round (360 °) or more.

Generally, the pressure P1 inside the shaft 1 (that is, the pressure on the side opposite to the excavation shaft) is almost atmospheric pressure, but the pressure P2 on the side of the shaft 1 is generally higher than the pressure P1 inside the shaft 1. Become. Therefore, when the wellhead seal device having the above-described configuration is used, the pressure P2 on the side of the excavation well acts in a direction of reducing the inner peripheral portion of the elastic seal member 14 and the tip of the swing backing plate 18, so that the elastic seal The member 14 can be firmly pressure-resistant supported by the rocking backing plate 18 against the pressure P2 on the digging side.

Further, the shield machine 6 is connected to the wellhead 4 of the vertical shaft 1.
Since the tip of the rocking backing plate 18 can be expanded by the protruding piece tightening wire 22 in advance when the vehicle is started from the ground, the rocking backing plate 18 and the bit (cutting blade) 11 projecting on the peripheral edge of the tip of the shield machine 6 rock. It is possible to prevent contact with the moving backing plate 18. Moreover, when the tip of the rocking backing plate 18 is transferred from the outer periphery of the tail portion of the shield boring machine 6 onto the outer peripheral surface of the tunnel segment 7 by the further advance of the shield backing machine 6, the backing plate 18 of the rocking backing plate 18 is moved. Since the tip can be maintained at a required expansion degree by the protruding piece tightening wire 22, the swing backing plate 1
It is possible to prevent the tip of 8 from coming into contact with the wire brush-shaped sealing means 12 provided in the tail portion of the shield machine 6.

After the space between the inner peripheral surface of the wellhead 4 and the outer peripheral surface of the tunnel segment 7 is sealed by the wellhead sealing device, the backfill material injection pipe 24 provided in the wellhole 2 is provided.
As shown in FIG. 1, the backfill material can be injected into the space outside the elastic seal member 14.

FIG. 4 is a longitudinal sectional view of an essential part showing an embodiment in which the wellhead sealing device of the first embodiment is applied to the wellhead on the arrival side of a shield machine of a vertical shaft. As you can see from Figure 4,
Also at the wellhead on the arrival side of the shield machine, the swing backing plate 18 of the wellhead sealing device is arranged along the side surface of the elastic seal member 14 on the inner side of the vertical shaft, and the tip is expanded to the side of the drilling hole. Thus, it is swingably attached to the wellhead 4.

Therefore, even at the wellhead 4 on the arrival side of the shield machine, the pressure on the side of the excavation works in the direction of reducing the diameter of the inner peripheral portion of the elastic seal member 14 and the tip of the swing backing plate 18, so that the elasticity is reduced. The seal member 14 can be firmly pressure-resistant supported by the rocking backing plate 18 against the pressure on the digging side. On the other hand, when the shield machine 6 reaches the wellhead 4, the tip of the rocking backing plate 18 is expanded together with the elastic seal member 14 in advance to the digging mine side by the protruding piece tightening wire 22 of the backing plate expanding means 20. Therefore, it is possible to prevent the bit (cutting blade) 11 and the like protruding from the peripheral edge of the tip of the shield machine 6 from coming into contact with the elastic seal member 14 or the swing backing plate 18.

FIG. 5 and FIG. 6 show a second embodiment of the present invention. FIG. 5 is a longitudinal sectional view of a main part when a wellhead sealing device is applied to a wellhead on the starting side of a shield machine. FIG. 6 is an explanatory view of an arrangement state of the seal member expanding wire shown in FIG. 5. In these figures, the same components as those in the first embodiment are denoted by the same reference numerals.

The wellhead seal device of the second embodiment is characterized in that it is provided with a seal member expanding means 25 for expanding the inner peripheral portion of the elastic seal member 14. In this embodiment, the seal member expanding means 25 includes a plurality of passages arranged in the inner peripheral surface of the wellhead 4 (that is, the inner peripheral surface of the cover plate 4) and the inner peripheral portion of the elastic seal member 14 in the circumferential direction. It has rings 26 and 27 and a seal member expanding wire 28. The seal member expanding wire 28 is alternately inserted into the through ring 26 provided on the inner peripheral surface of the wellhead 4 and the through ring 27 provided on the inner peripheral portion of the elastic seal member 14 so that the elastic seal member 14 is inserted. It is possible to expand the inner peripheral portion of the elastic seal member 14 by tightening the seal member expanding wire 28. In addition, this seal member expanding wire 2
8 may be wound around the elastic seal member 14 for one round (360 °) or more, and a part of the inner peripheral portion of the elastic seal member 14 may be covered with a plurality of seal member expanding wires. It is also possible to expand each.

Further, in this second embodiment, the vertical shaft 1
The mine wall 2 is provided with wire guide means 29 for guiding the seal member expanding wire 28 from the inside of the pit 4 into the inside of the vertical shaft 1. Although both ends of the seal member expanding wire 28 may be pulled in order to expand the inner peripheral portion of the elastic seal member 14, one end of the seal member expanding wire 28 is connected to the wellhead 4
It may be fixed inside and the other end may be pulled. Therefore, both ends of the seal member expanding wire 28 can be guided to the inside of the vertical shaft 1 by the wire guiding means 29.
Only one end of the seal member expanding wire 28 may be guided into the vertical shaft 1.

The wellhead sealing device of the second embodiment is the first
Similar to the embodiment, the present invention can be applied to a shield excavator starting side entrance and a shield excavator reaching side entrance, but the inner peripheral portion of the elastic seal member 14 is used as a seal member expanding means 2 when necessary.
Since it can be widened or maintained at a required widening opening by 5, the shield machine 6 or the swing backing plate 1
When expanding the inner peripheral portion of the elastic seal member 14 at 8,
The seal member expanding means 25 can assist the expanding operation of the inner peripheral portion of the elastic seal member 14. Therefore,
The elastic seal member 14 can be easily and surely expanded. Further, as shown in FIGS. 7A and 7B, even in the case of the elastic seal member 14 attached to a non-circular wellhead such as a rectangular shape or a horizontally-oriented Daruma shape, the rectangular elastic seal member 14 is It is possible to easily widen a corner portion or a portion which is difficult to be widened only by the shield machine, such as a central constriction of the laterally-sealed elastic seal member 14.

In the wellhead seal device of the second embodiment, the through-holes 26 arranged on the inner peripheral surface of the wellhead 4 and the through-rings 27 arranged on the inner peripheral portion of the elastic seal member 14 are alternately arranged. The inner peripheral portion of the elastic seal member 14 can be easily expanded by tightening the seal member expansion wire 28 that has been inserted through. Further, since the seal member expanding wire 28 can be guided from the inside of the wellhead 4 into the vertical shaft 1 through the wire guiding means 29, the tightening operation of the seal member expanding wire 28 for expanding the elastic seal member 14 is performed. Can be easily performed in the vertical shaft 1.

FIG. 8 is a longitudinal sectional view of a main part of a wellhead sealing device showing a third embodiment of the present invention. In the figure, the same components as those in the first embodiment are denoted by the same reference numerals.

The wellhead sealing device according to the third embodiment is attached to the wellhole 4 of the vertical shaft 1 at a distance in the inner and outer directions of the vertical shaft 1 so that the inner peripheral surface of the wellhole 4 and the shield machine 6 or the tunnel segment 7 are provided. Outer and inner elastic seal members 14A and 14B for sealing between the outer peripheral surface, outer and inner elastic seal members 14A and 14B, the inner peripheral surface of the wellhead 4, and the outer peripheral surface of the shield machine 6 or the tunnel segment 7. The pressurizing means 30 for maintaining the inside of the airtight space defined by the above at a pressure higher than the external pressure and the outer elastic sealing member 14A are arranged along the side surface on the digging side and the tip is Is a plurality of outer swing backing plates 1 swingably attached to the wellhead 4 so as to be expanded to the opposite side, that is, the inside of the shaft.
8A and the inner side elastic seal member 14B are arranged on the side surface on the inner side of the vertical shaft (that is, the side surface on the side opposite to the side surface on the excavation shaft side), and swing to the wellhead 4 so that the tip is expanded to the excavation shaft side. A plurality of inner swing backing plates 18B movably mounted
And A gas or liquid such as air or a resin or the like can be press-fitted into the airtight space by the pressurizing means 30, but if a filler having elasticity is press-fitted and sealed, the sealing property and elasticity are excellent. You can get a wellhead sealing device.

The outer rocking backing plate 18A is brought into contact with the shield excavator 6 or the outer peripheral surface of the tunnel segment 7 while the tip of the outer swing backing plate 18A is expanded toward the inside of the vertical shaft, so that the inner peripheral surface of the wellhead 4 and the shield excavator are advanced. 6 or the outer peripheral surface of the tunnel segment 7, the side surface of the outer side elastic seal member 14A on the side of the excavation hole can be pressure-resistant supported. Also, the inner swing backing plate 18
In B, the tip is a shield machine 6 in the expanded state to the digging side.
Alternatively, by contacting the outer peripheral surface of the tunnel segment 7, the inner elastic seal member 14B is formed between the inner peripheral surface of the wellhead 4 and the outer peripheral surface of the shield machine 6 or the tunnel segment 7.
The side surface on the inner side of the vertical shaft can be pressure-resistant supported.

Furthermore, the wellhead seal device of the third embodiment is
The outer and inner rocking backing plates 18A and 18B are provided with outer and inner backing plate expanding means 20A and 20B for expanding the tips of the rocking backing plates 18A and 18B to positions separated from the outer circumference of the shield machine 6, respectively. Then, the outer and inner swing backing plates 18
Similar to the first embodiment, A and 18B are swingably attached to the fixed plate 16 fixed to the wellhead 4 via hinge portions 19A and 19B, and the outer and inner backing plate expansions are performed. Means 20A and 20B respectively correspond to each rocking backing plate 18
Projecting pieces 21A and 21B provided on A and 18B and extending in the direction opposite to the tips of the swing backing plates 18A and 18B with respect to the hinge parts 19A and 19B, and projecting pieces connected to the projecting pieces 21A and 21B, respectively. It has tightening wires 22A and 22B. Therefore, the protruding pieces 21A, 21B are tightened by tightening the outer and inner protruding piece tightening wires 22A, 22B.
As in the first embodiment, the tip ends of the outer and inner swing backing plates 18A and 18B can be expanded by reducing the diameter of the.

Further, in the wellhead seal device of the third embodiment, the outer protruding piece tightening wire 2 is attached to the wellhole 2 of the vertical shaft 1.
Wire guide means 29 for guiding 2A from the inside of the well 4 to the inside of the shaft 1 (that is, the outside of the well on the opposite side to the excavation hole) is provided.

The wellhead seal device according to the third embodiment, whether it is provided at the wellhead on the starting side of the shield machine or at the wellhead on the arrival side of the shield machine,
When necessary, the pressurizing means 30 allows the inside of the airtight space defined by the outer and inner elastic seal members 14A and 14B, the inner peripheral surface of the wellhead 4 and the outer peripheral surface of the shield machine 6 or the tunnel segment 7 to be inside the shaft. (That is, the external pressure on the side opposite to the excavation hole) P1 and the pressure P3 higher than the external pressure P2 on the excavation hole side, so that the outer and inner elastic seal members 14A and 14B swing outward and inner. The backing plates 18A and 18B can firmly support the pressure.

Also, the outer and inner swing backing plates 18A,
Since the tip of 18B can be expanded by the backing plate expanding means 20A, 20B together with the outer and inner elastic seal members 14A, 14B when necessary, the bit (projected on the edge of the tip of the shield machine 6 ( It is possible to prevent the cutting edge 11 and the like from coming into contact with the outer or inner swing backing plates 18A, 18B and the outer or inner elastic seal members 14A, 14B. In addition, the outer or inner swing backing plate 18
Even when the tips of A and 18B are transferred from the outer periphery of the tail portion of the shield machine 6 at the time of starting to the outer peripheral surface of the tunnel segment 7, the tips of the outer or inner rocking backing plates 18A and 18B are placed outside or inside. Since it is possible to maintain the required expansion degree by the backing plate expanding means 20A, 20B, the tip of the outer or inner rocking backing plates 18A, 18B is shielded by the shield machine 6.
It is possible to prevent contact with the wire brush-shaped sealing means 12 provided on the tail portion of the.

In the third embodiment, the outer or inner swing piece backing plates 18A, 18B are tightened by tightening the outer or inner projecting piece tightening wires 22A, 22B connected to the projecting pieces 21A, 21B. The tip of can be easily expanded. Further, since the outer protruding piece tightening wire 22A can be guided from the inside of the wellhead 4 to the inside of the vertical shaft 1 through the wire guiding means 29, the outer protruding for expanding the outer swing backing plate 18A. Single tightening wire 2
The tightening operation of 2A can be easily performed in the vertical shaft 1.

FIG. 9 shows a fourth embodiment of the present invention. In the figure, the same reference numerals are attached to the same components as those in the first and third embodiments.

The wellhead sealing device of the fourth embodiment is the third one.
Outer and inner elastic seal members 14A in the embodiment,
Instead of 14B, the inner peripheral surface of the wellhead 4 and the shield machine 6
Alternatively, an elastic seal member 14C having an internal hollow structure that seals with the outer peripheral surface of the tunnel segment 7 is used, which is different from the third embodiment described above, and other configurations are the same as the third embodiment. The elastic seal member 14C of the fourth embodiment has a substantially C-shaped cross section, and a pair of inner and outer peripheral ends are attached to the wellhead 4. Further, the elastic seal member 1 having a hollow structure
The interior of 4C can be filled with pressurized gas, elastic material, or the like by the pressurizing means 30.

Therefore, the wellhead sealing device of the fourth embodiment is similar to the third embodiment, even when it is provided at the wellhead on the starting side of the shield machine, and at the wellhead on the arrival side of the shield machine. Even when the elastic seal member 14C is provided, the elastic seal member 14C having an internal hollow structure is made to have a pressure P3 higher than the pressure P1 inside the shaft and the external pressure P2 on the side of the excavation shaft when necessary, by making the elastic seal member 14C outside. Also, it is possible to firmly support the inner side of the swing backing plates 18A and 18B against pressure.

Also, the outer and inner swing backing plates 18A,
Since the tip of 18B can be expanded by the backing plate expanding means 20A, 20B together with the inner peripheral part of the elastic seal member 14C when necessary, a bit (cutting blade) projecting on the periphery of the tip of the shield machine 6 ) 11 and the like can be prevented from coming into contact with the outer or inner swing backing plates 18A, 18B and the elastic seal member 14C. Also, when the tips of the outer or inner swing backing plates 18A and 18B are transferred from the outer periphery of the tail portion of the shield machine 6 to the outer peripheral surface of the tunnel segment 7 at the time of starting, the outer or inner swing backing plates Board 18
A backing plate expanding means 20 with the tips of A and 18B outside or inside
Since the required expansion opening can be maintained by A and 20B, the wire brush-like sealing means 12 in which the tips of the outer or inner swing backing plates 18A and 18B are provided in the tail portion of the shield machine 6 is provided. It is possible to prevent contact with.

Also in the fourth embodiment, the outer or inner swing backing plates 18A, 18B are tightened by tightening the outer or inner protruding piece tightening wires 22A, 22B connected to the protruding pieces 21A, 21B. The tip of can be easily expanded. Further, since the outer protruding piece tightening wire 22A can be guided from the inside of the wellhead 4 to the inside of the vertical shaft 1 through the wire guiding means 29, the outer protruding for expanding the outer swing backing plate 18A. Single tightening wire 2
The tightening operation of 2A can be easily performed in the vertical shaft 1.

FIG. 10 shows a fifth embodiment of the present invention. In the figure, the same components as those in the first, third and fourth embodiments are designated by the same reference numerals.

The wellhead sealing device of the fifth embodiment is the fourth
Unlike the fourth embodiment, the elastic seal member 14D having a tubular inner hollow structure is used in place of the elastic seal member 14C having an inner hollow structure having a substantially C-shaped cross section in the embodiment, and other configurations are the same as the above. This is similar to the fourth embodiment. The elastic seal member 14D of the fifth embodiment can be easily fixed to the inner peripheral surface of the wellhead 4 with an adhesive or the like. In addition, the pressurizing means 30 is provided inside the elastic seal member 14D having a hollow structure.
Thus, for example, it is possible to fill a pressurized gas, an elastic material or the like.

Therefore, the wellhead seal device of the fifth embodiment is similar to the fourth embodiment, even when it is provided at the wellhead on the starting side of the shield machine, and at the wellhead on the arrival side of the shield machine. Even when the elastic seal member 14D is provided, the elastic seal member 14D having an internal hollow structure is made to have a pressure P3 higher than the pressure P1 inside the shaft and the external pressure P2 on the side of the excavation shaft when necessary, so that the elastic seal member 14D is located outside. Also, the rocking backing plates 18A and 18B on the inside can firmly support the pressure resistance. Since the elastic seal member 14D has a tubular shape, the elastic seal member 14C of the fourth embodiment is used.
It is possible to secure a higher hermeticity.

Although the embodiments shown in the drawings have been described above, the present invention is not limited to the embodiments described above,
Various modifications can be made to the components within the scope of the invention described in the claims. For example, also in the third to fifth embodiments shown in FIGS. 8 to 10, the elastic seal members 14A, 14B, 14C and 14D are used.
It is possible to provide a seal member expanding means for expanding the seal member.

Further, the wellhead seal device according to the present invention can be applied not only to the wellhead to which the shield construction method is applied but also to the wellhead to which the propulsion method is applied, for example. In this case, a blade tip pipe with a tapered tip is used as the leading device in place of the shield machine, and an embedded pipe, that is, a cylinder body is used in place of the tunnel segment as the duct forming body. Furthermore, the wellhead sealing device according to the present invention is used not only for wellholes formed in the wall of a vertical shaft, but also for wellholes for branch tunnel tunneling formed in the wall of a tunnelhole, or for vertical shaft excavation formed on the surface of the ground. The same can be applied to the wellheads, etc.

[0080]

As is apparent from the above description, according to the present invention, the present invention can be applied to either the leading-side equipment starting side entrance or the reaching-side entrance, and damage to the components of the leading equipment or the entrance sealing device. It is possible to provide a wellhead sealing device that is capable of preventing the above and has excellent pressure-resistant sealing properties.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view of a main part showing a first embodiment of a wellhead seal device when the present invention is applied to a wellhead on the starting side of a shield machine of a vertical shaft.

FIG. 2 is a perspective view showing an example of a hinge connection configuration of a swing backing plate and a fixed plate used in the wellhead seal device of FIG.

FIG. 3 is a side view schematically showing an arrangement state of a swing backing plate and a protruding piece tightening wire in the wellhead sealing device of FIG.

FIG. 4 is a longitudinal cross-sectional view of essential parts showing an embodiment in which the wellhead sealing device shown in FIG. 1 is applied to a wellhead on the shield machine side of a vertical shaft.

FIG. 5 is a longitudinal cross-sectional view of a main part of a wellhead seal device showing a second embodiment when the present invention is applied to a shield excavator starting side wellhead.

FIG. 6 is an explanatory view of an arrangement state of the seal member expanding wire shown in FIG.

7A and 7B are schematic explanatory views each showing a modification of the shape of the elastic seal member in the second embodiment.

FIG. 8 is a longitudinal cross-sectional view of a main part of a wellhead seal device showing a third embodiment in which the present invention is applied to a starter well of a shield machine.

FIG. 9 is a longitudinal cross-sectional view of a main part of a wellhead sealing device showing a fourth embodiment in which the present invention is applied to a launching side entrance of a shield machine.

FIG. 10 is a longitudinal cross-sectional view of a main part of a wellhead seal device showing a fifth embodiment in which the present invention is applied to a starter well of a shield machine.

[Explanation of symbols]

 1 Vertical shaft 2 Well wall 4 Well mouth 6 Shield machine (leading device) 7 Tunnel segment (pipe forming body) 11 Bit (cutting blade) 12 Wire brush-like sealing means 14, 14A, 14B Elastic seal member 14C Internal hollow structure Elastic seal member 14D Elastic seal member having an internal hollow structure 16, 16A, 16B Fixed plate 18, 18A, 18B Swing backing plate 19 Hinge part 20, 20A, 20B Backing plate expanding means 21, 21A, 21B Projecting piece 22 , 22A, 22B Projecting piece tightening wire 24 Backfilling material injection pipe 25, 25A, 25B Seal member expanding means 26, 27 Circular ring 28 Seal member expanding wire 29 Wire guide means 30 Pressurizing means

Claims (11)

[Claims] 1. A wellhead sealing device for sealing between a wellhead and an outer peripheral surface of a pipe forming body or a tip end of the conduit forming body disposed in an excavation well formed in the ground by communicating with the wellhead. An elastic seal member attached to the wellhead such that an inner peripheral portion thereof is in sliding contact with the outer peripheral surface of the conduit forming body or the leading device, and a side surface opposite to the side surface of the elastic seal member on the digging pit side. Are arranged along and are swingably attached to the wellhead so that the tip is opened to the side of the excavation shaft, and the tip is brought into contact with the outer peripheral surface of the pipe forming body by the expansion to the side of the excavation hole. A plurality of swing backing plates that support the back surface of the elastic seal member between the inner peripheral surface of the wellhead and the outer peripheral surface of the leading device or the conduit forming body; And a backing plate expanding means for expanding to a position separated from the outer periphery of the leading device. A wellhead sealing device. 2. Each of the swing backing plates is swingably attached to a fixed plate fixed to the wellhead via a hinge portion, and the backing plate expanding means includes each swing backing plate. A projecting piece tightening wire connected to the projecting piece, the projecting piece being provided on the plate and extending in a direction opposite to the tip of the swing backing plate with respect to the hinge part; and the projecting piece tightening wire. The wellhead sealing device according to claim 1, wherein the tip of the swing backing plate is expanded by tightening. 3. The wellhead seal device according to claim 1, further comprising a seal member expanding means for expanding the inner peripheral portion of the elastic seal member. 4. The seal member expanding means includes a plurality of through rings arranged circumferentially on the inner peripheral surface of the wellhead and the inner peripheral portion of the elastic seal member, and on the inner peripheral surface of the wellhead. The elastic member further includes a seal member expanding wire that is alternately inserted between the arranged communicating ring and the communicating ring arranged on the inner peripheral portion of the elastic seal member, and the elastic member is formed by tightening the seal member expanding wire. The wellhead sealing device according to claim 3, wherein the inner peripheral portion of the seal member is expanded. 5. The wire hole guide means for guiding the seal member expanding wire from the inside of the hole to the outside of the hole on the opposite side of the excavation hole is provided at the hole. Item 4. A wellhead sealing device according to item 4. 6. A wellhead sealing device for sealing between a wellhead and an outer peripheral surface of a pipe forming body or a tip end of the conduit forming body disposed in an excavation well formed in the ground by communicating with the wellhead. An outer side which is arranged in the wellhead with a space in the direction of the wellhole and is attached to the wellhole such that an inner peripheral portion of the well forms the sliding contact with the outer peripheral surface of the conduit forming body or the leading device. And an inner elastic seal member, and is arranged along the side surface of the outer elastic seal member on the side of the excavation hole, and is swingably attached to the wellhead so that the tip is expanded to the side opposite to the excavation hole. The tip end abuts the outer peripheral surface of the leading equipment or conduit forming body by expanding to the side opposite to the digging pit and the inner peripheral surface of the wellhead and the outer peripheral surface of the leading equipment or conduit forming body. A plurality of outer rockers supporting the side surface of the outer elastic seal member on the digging side. A backing plate and a side surface of the inner elastic seal member opposite to the side surface on the side of the excavation hole, and is swingably attached to the wellhead so that the tip is expanded to the side of the excavation hole. The tip is brought into contact with the outer peripheral surface of the leading device or the conduit forming body by expanding to the digging pit side, and the tip is abutted with the outer peripheral surface of the mine mouth and the outer peripheral surface of the leading device or the conduit forming body. A plurality of inner swing backing plates that support a side surface of the inner elastic seal member opposite to the side surface on the digging side, and the tips of the outer and inner swing backing plates are separated from the outer periphery of the leading device. A wellhead sealing device comprising outer and inner backing plate expanding means for expanding to a position. 7. The outer and inner swing backing plates are swingably attached to a fixed plate fixed to the wellhead via a hinge portion, and the outer and inner backing plate expanding Means respectively provided on each swing backing plate and extending toward the hinge portion in a direction opposite to the tip of the swing backing plate, and a projecting piece tightening wire connected to the projecting piece. 7. The wellhead seal device according to claim 6, wherein the tip ends of the outer and inner swing backing plates are expanded by tightening the outer and inner protruding piece tightening wires. 8. A wire guide means is provided at the wellhead for guiding the outer protruding piece tightening wire from the inside of the wellhole to the outside of the wellhead on the side opposite to the pit. The wellhead sealing device according to claim 7. 9. A wellhead sealing device for sealing between a wellhead and an outer peripheral surface of a pipe forming body or a tip end of the conduit forming body disposed in an excavation well formed in the ground by communicating with the wellhead. And an elastic seal member having an internal hollow structure attached to the wellhead such that an inner peripheral portion thereof is in sliding contact with the outer peripheral surface of the pipe forming body or the leading device, and along the side surface of the elastic seal member on the digging pit side. Is arranged and swingably attached to the wellhead so that the tip is opened to the side opposite to the digging well, and the tip is formed into the leading device or conduit by the extension to the side opposite to the digging well. A plurality of outer rocking backings that contact the outer peripheral surface of the body and support the side surface of the elastic seal member on the excavation pit side between the inner peripheral surface of the wellhead and the outer peripheral surface of the leading device or the conduit forming body. A plate and a side surface opposite to the side surface of the elastic seal member on the side of the digging pit And is swingably attached to the wellhead so that the tip is expanded toward the digging side, and the tip is brought into contact with the outer peripheral surface of the leading device or the conduit forming body by expanding toward the digging side. A plurality of inner rocking backing plates that contact and support the side surface of the elastic seal member opposite to the side surface on the excavation pit side between the inner peripheral surface of the wellhead and the outer peripheral surface of the leading device or the pipe forming body. And an outer and inner backing plate expanding means for expanding the ends of the outer and inner swinging backing plates to positions separated from the outer periphery of the leading device, respectively. . 10. The outer and inner swing backing plates are swingably attached to fixed plates fixed to the wellhead via hinges, respectively, and the outer and inner backing plate expansions are performed. Means respectively provided on each swing backing plate and extending toward the hinge portion in a direction opposite to the tip of the swing backing plate, and a projecting piece tightening wire connected to the projecting piece. 10. The wellhead seal device according to claim 9, wherein the tip ends of the outer and inner swing backing plates are expanded by tightening the outer and inner protruding piece tightening wires. 11. The wellhead is provided with wire guide means for guiding the outer protruding piece tightening wire from the inside of the wellhead to the outside of the wellhead on the side opposite to the excavation well. The wellhead sealing device according to claim 9.