JP4011271B2 - Tunnel excavator - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a tunnel excavator for excavating a tunnel for burying a small-diameter pipe body in the ground.
[0002]
[Prior art]
Conventionally, in order to embed pipes such as small-diameter sewage pipes in the ground, pipes having a certain length are sequentially followed by tunnel excavators and propelled and buried in the ground according to the excavation of the tunnel excavator. Is going on. In this tunnel excavator, when excavated sediment is configured to be discharged to the rear of the tunnel through the discharge pipe, a pinch valve is provided at the tip of the discharge pipe, and the pinch valve is closed when excavation is stopped. By maintaining the earth and sand chamber on the back side of the cutter head at a predetermined mud pressure, the face can be stabilized, the drainage pipe can be inspected and clogged, and the pinch valve opening is adjusted. It adjusts the amount of soil discharged, mud pressure, mud pressure, etc.
[0003]
The pinch valve is usually provided in the skin plate of the tunnel excavator. In particular, in the mud pressure shield, the pinch valve is disposed in the vicinity of the rear of the isolation at the front part of the skin plate. The reason is that when the earth and sand excavated by the cutter head is taken into the earth and sand chamber formed between the cutter head and the partition wall, and the mud is sent back using the mud pressure in the earth and sand chamber, Since the viscosity of the mud is larger and the fluidity is poorer than the mud water, the length of the mud pressure that can be pumped backward is shortened by the mud pressure, and if a pinch valve is arranged behind the length, the front of the pinch valve is placed. This is because sediment blockage occurs on the face side.
[0004]
[Problems to be solved by the invention]
However, in the skin plate in the vicinity of the rear part of the isolation where the pinch valve is installed, various devices and a large number of parts are provided, particularly in a tunnel excavator with a diameter of about 30 to 60 cm, Since these devices and parts are arranged in a dense state, the working space is remarkably limited, and there is a problem that maintenance and inspection of the pinch valve and repair when the pinch valve fails are difficult.
[0005]
Furthermore, when the pressure inside the pipe suddenly increases due to the concentration of the joint part of the drainage pipe in the installation part of the pinch valve, the soil discharges from this joint part or the pinch valve is damaged and replaced. In some cases, the discharged soil erupts and contaminates the interior of the machine, which may adversely affect various devices such as driving means and measuring devices.
[0006]
The present invention has been made in view of such problems, and the object of the present invention is to prevent the inside of the machine from being soiled by the discharged soil even when discharged soil is ejected at the time of replacement of the valve. It is to provide a tunnel excavator that can be easily replaced.
[0007]
[Means for Solving the Problems]
  In order to achieve the above object, a tunnel excavator according to the present invention includes a cylindrical skin plate, a partition wall disposed in front of the skin plate, and a skin in front of the partition wall. The rotary excavation part disposed in the front opening of the plate, the earth and sand chamber formed between the rotary excavation part and the partition, and the earth and sand in the earth and sand chamber sent out through the discharge port provided in the partition are discharged backward. A tunnel excavator provided with a soil discharge pipe, wherein a valve installation chamber that is cut off from the inside of the skin plate is formed on the rear side of the soil discharge port provided in the partition wall, and the valve installed in the valve installation chamber The connecting short pipe is integrally connected to the front and rear opening ends of the front connecting short pipe and the rear connecting short pipe.With the exitIt is characterized by the fact that it communicates with the earth removal pipe.
[0008]
In the tunnel excavator, the invention according to claim 2 has a structure in which the valve installation chamber is exposed to the outside of the skin plate through an opening formed in a part of the skin plate.
[0009]
  Further, in the invention according to claim 3, the rear connection short pipe of the valve is provided in a through hole provided in the rear wall of the valve installation chamber, and the front connection short pipe of the valve is provided in the front wall of the valve installation chamber.Earth exitAnd at least one of the connecting short tubes is configured to be movable in the tube axis direction.
[0010]
[Action]
The earth and sand excavated by the rotary excavation part of the tunnel excavator is taken into the earth and sand chamber between the rotary excavation part and the bulkhead, and then sent from the drainage port provided in the bulkhead to the earthpipe through the valve. It is discharged backward through the clay pipe. At this time, the mud pressure in the earth and sand chamber is set to a predetermined pressure by adjusting the opening of the valve. The mud pressure suppresses the face and stabilizes the face, and the mud in the earth and sand room is removed. The pressure is positively pushed out to the valve side through the discharge port.
[0011]
During excavation by this tunnel excavator, even if mud is sprayed into the valve installation chamber from the short pipe connecting part of the valve due to a sudden increase in mud pressure, the valve installation chamber is protected by a waterproof cover. Since it is cut off from the inside of the plate, mud soil can be prevented from scattering and flowing into the skin plate at the rear of the partition wall where equipment and many parts are arranged. There is no risk of fouling.
[0012]
In addition, as described in claim 2, the valve installation chamber has a structure that faces the outside of the skin plate through an opening formed in a part of the skin plate, so that the valve needs to be repaired or replaced. Sometimes, after pulling the tunnel excavator into the start shaft, regardless of the equipment arranged in the skin plate, only the valve can be easily taken out from the outside of the skin plate through the opening, The repair and replacement work can be easily performed, and even during this work, the leaked mud is not discharged from the valve installation chamber to the outside of the skin plate, and the inside of the machine is not polluted.
[0013]
Furthermore, according to the invention of claim 3, the rear connection short pipe of the valve is a through hole provided in the rear wall of the valve installation chamber, and the front connection short pipe of the valve is a through hole provided in the front wall of the valve installation chamber. Since each of the connecting short pipes is rotatably inserted in the holes and is movable in the pipe axis direction, the valve can be easily and reliably attached and detached from the outside of the skin plate, and the valve The work of removing the bolts that fasten the main body and the front and rear connecting short pipes and the work of fastening with the bolts can be performed efficiently, and the workability is remarkably improved.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Next, a specific embodiment of the present invention will be described with reference to the drawings. Reference numeral 1 denotes a cylindrical skin plate which forms a body portion of a small diameter tunnel excavator A having a diameter of 30 to 60 cm, and has a front end opening. A partition 3 is provided with a rotary excavation part 2 composed of a cutter head, and partitions the rotary excavation part 2 side and the rear side in the machine at the front part of the skin plate 1 in the vicinity of the rear of the rotary excavation part 2. A space between the rear surface of the rotary excavation unit 2 and the front surface of the partition wall 3 is formed in the earth and sand chamber 4, and the lower part of the partition wall 3 is formed in the earth and sand chamber 4 from the rear surface side of the partition wall 3. The earth discharge port 5 communicated with the earth discharge pipe 5 is provided, and the earth discharge port 5 communicates with the earth discharge pipe 8 through the air pinch valve 7 installed in the valve installation chamber 6.
[0015]
The skin plate 1 is divided into two front and rear skin plate portions 1A and 1B. The outer peripheral portion of the partition wall 3 is integrally fixed to the front skin plate portion 1A and the rear end of the front skin plate portion 1A. A partition wall 9 is fixed to the part, and a space between the partition wall 3 and the partition wall 9 is formed in the equipment installation chamber 10, and the valve installation room 6 is provided in the lower part of the equipment installation chamber 10. Is provided. In addition, a through hole 11 is provided in the lower part of the partition wall 9 so as to face the rear of the earth discharge port 5 provided in the lower part of the partition wall 3 and penetrates between the front and rear surfaces on the same center line as the earth discharge port 5. The front end portion of the soil discharge pipe 8 is inserted into the rear portion of the through hole 11 and communicated with the rear end of the air pinch valve 7.
[0016]
In addition, the valve installation chamber 6 is formed by a waterproof cover 12 whose upper peripheral wall portion is curved in a dome shape disposed in the lower part of the equipment installation chamber 10, and the front and rear end surfaces of the waterproof cover 12 are the front and rear surfaces. It is formed by a space surrounded by the partition wall 3, the partition wall 9, and the waterproof cover 12 by being watertightly joined and fixed to the lower part of the opposing surface of the partition wall 3 as the wall and the partition wall 9 as the rear wall. The valve installation chamber 6 is separated from the equipment installation chamber 10 outside the waterproof cover 12 by a waterproof cover 12, and is shut off. Furthermore, the lower end of the valve installation chamber 6 is opened by cutting the lower peripheral portion of the front skin plate portion 1A surrounded by the lower end of the waterproof cover 12, and faces the outside of the skin plate through the opening portion 13. A closing plate 14 is detachably attached to the opening 13 with a bolt.
[0017]
As shown in FIG. 3, the air pinch valve 7 disposed in the valve installation chamber 6 is in contact with the inner peripheral surface of a cylindrical casing 7A having flange portions 7a, 7a at both ends, and both ends are connected to the casing 7A. A cylindrical rubber valve body 7B is disposed between the rubber valve body 7B and the casing 7A. The cylindrical rubber valve body 7B is disposed between the rubber valve body 7B and the casing 7A. By connecting pressurized air to the hose 7E that is connected to the air port 7D from the outside through an air port 7D that is drilled at an appropriate position in the center of the casing 7A in the longitudinal direction, the opposed surface of the valve element 7B is indicated by a two-dot chain line. It is configured so that the valve is closed by being deformed and pressed into a flat shape.
[0018]
Further, at the front and rear opening ends of the air pinch valve 7, the earth discharge port 5 provided at the lower part of the partition wall 3 and the through hole 11 provided at the lower part of the partition wall 9 are respectively connected via annular packing materials 18 and 19. Connection short pipes 16 and 17 that are rotatably inserted are integrally attached. In these connection short tubes 16, 17, the front connection short tube 16 is in contact with the front surface of the front annular sandwiching plate 7C at the rear end thereof, and is integrally fixed to the annular sandwiching plate 7C by the bolt 15 A flange 16a is provided, and the rear connecting short tube 17 is in contact with the rear surface of the rear annular sandwiching plate 7C at the front end thereof, and is integrated with the annular sandwiching plate 7C by the bolt 15. A flange portion 17a fixed to is provided.
[0019]
Further, the length of the front connection short pipe 16 is made longer than the length of the rear connection short pipe 17, and the entire length of the air pinch valve 7 to which these front and rear connection short pipes 16, 17 are attached, That is, the length between the opening ends of the front and rear connection short pipes 16 and 17 is longer than the dimension between the discharge opening 5 and the opposed opening end of the through hole 11, and the front connection short pipe 16 is extended to the discharge opening 5. The rear connection short tube 17 is formed in such a length that it can be detached from the front end opening of the through-hole 11 when inserted to the middle.
[0020]
In addition, when the front and rear connection short tubes 16 and 17 are inserted into the discharge port 5 and the through hole 11 and the air pinch valve 7 is disposed in the valve installation chamber 10, the front connection short tube 16 is more than necessary. In order to prevent the air pinch valve 7 from moving forward by moving into the discharge port 5 and detaching the rear connection short tube 17 from the through hole 11, the flange portion 17a of the rear connection short tube 17 is provided. A stopper member 20 is interposed between the flange portion 16a of the front connection short pipe 16 and the opening rear end surface of the earth discharge port 5 in the state of being in contact with the front end surface of the through-hole 11, so that the air pinch valve 7 is moved in the front-rear direction. Is configured to be disposed at a predetermined position. The stopper member 20 is integrally fixed to the inner surface of a closing plate 14 that closes the opening 13 of the valve installation chamber 6. After the air pinch valve 7 is disposed in the valve installation chamber 6, the opening 13 is closed. At the same time as closing by 14, a stopper member 20 is interposed between the flange portion 16 a of the front connection short pipe 16 and the opening rear end surface of the earth discharging port 5 to prevent the air pinch valve 7 from moving back and forth.
[0021]
The length of the rear connection short tube 17 may be formed longer than the length of the front connection short tube 16, in short, either one of the connection short tubes is formed longer than the other connection short tube. Just keep it.
[0022]
  The rotary excavation part 2 composed of the cutter head is rotatably supported at the center part of the partition wall 3 and the center part of the partition wall 9 at the front and rear ends of the rotary shaft 2a and disposed on the rear surface of the partition wall 9. The inner cone 2b that is gradually reduced in diameter toward the front end is fixed to the outer peripheral surface of the front end portion of the rotary shaft 2a that is driven to rotate by the drive motor 21 and protrudes into the earth and sand chamber 4. The outer cone 2c having a diameter gradually increased toward the front end is fixed to the inner peripheral surface of the front end portion of the front skin plate portion 1A. Further, the inner cone rotates integrally with the rotating shaft 2a.2bAn earth and sand scraping plate 2d for agitating the mud in the earth and sand chamber 4 is projected from the outer peripheral portion of the rear end face.
[0023]
The rotary shaft 2a is covered with a cylindrical protective cover 22 made of a rigid material, and both front and rear end surfaces of the protective cover 22 are fixed to the center of the opposing surface between the partition wall 3 and the partition wall 9 to rotate the rotary shaft. While protecting 2a, it also has a role of transmitting a part of the propulsive force from the rear skin plate portion 1B to the front skin plate portion 1A. The upper end of the dome-shaped waterproof cover 12 is joined and fixed to the lower peripheral portion of the protective cover 22 by welding or the like.
[0024]
  Furthermore, the equipment arrangement room 10 includes an earth and sand room.4Earth pressure gauge 23 for measuring mud pressure in the soil, magnetic line generator (Zonte) 24 for measuring the position by transmitting to a receiver on the ground, biaxial inclinometer 25 for measuring rolling and pitching of tunnel excavator A, etc. Equipment is installed, and thisEquipment installation room TenAn inspection window 26 is provided on the upper peripheral portion of the front skin plate portion 1A that forms the ceiling wall.
[0025]
The rear end portion of the front skin plate portion 1A and the front end portion of the rear skin plate portion 1B are joined and connected to each other so as to be able to be bent, and are arranged at predetermined intervals in the circumferential direction on the inner peripheral surface of the rear skin plate portion 1B. A plurality of direction correcting jacks 27 are attached to the front ends of the partition walls 9 of the front skin plate portion 1A and the rod ends of the direction correcting jacks 27 are connected to the outer peripheral portion.
[0026]
The earth removal pipe 8 is disposed on the inner bottom portion of the rear skin plate 1B in the skin plate 1, and the rear end opening portion is provided under the ring-shaped connecting plate 28 fixed to the rear end of the rear skin plate 1B. The mounting holes 29 are supported in communication. The connecting plate 28 is formed by connecting a ring-shaped connecting plate 30 integrally provided at the front end opening of the foremost small-diameter pipe body B to be embedded with a bolt 31 to connect the small-diameter pipe body B to the tunnel excavator A. The small-bore tube body B is integrally provided with a ring-shaped connecting plate (not shown) at the rear end opening portion, and a plurality of small-bore tube bodies B are sequentially arranged in series. It is configured to be connected.
[0027]
Further, a communication hole in which a front and rear opening end portion of a sediment discharge pipe (not shown) communicating with the soil discharge pipe 8 on the same center line is inserted and supported below the front and rear connection plate 30 of each small-diameter pipe body B. 32 is provided, and is configured to discharge excavated earth and sand from the earth discharge pipe 8 to the start shaft C side through the earth and sand discharge pipe. The excavated sediment is carried out by the suction force of a vacuum pump (not shown) connected to and communicated with the rear end side of the sediment discharge pipe, and the front end of the soil discharge pipe 8 has an air intake assisting the suction of the vacuum pump. A slot 8a is provided.
[0028]
As shown in FIG. 4, the tunnel excavator A configured as described above excavates from the start shaft C toward the arrival shaft D. In the excavation, while rotating the rotary excavating part 2, the abutment plate f of the front / rear moving base F installed in the start shaft C is brought into contact with the rear end surface of the skin plate 1 so that the mobile base F is placed in the rear end portion of the start shaft C. This is done by extending the piston rods of the plurality of propulsion jacks E installed in the forward direction. When the tunnel excavator A digs into the ground for a certain length, the piston rod of the propulsion jack E is contracted and the moving base F is retracted, and then the skin plate 1 and the skin plate 1 are connected to the rear end of the skin plate 1 of the tunnel excavator A. A small bore tube B having substantially the same diameter is connected, and the rear end of the small bore tube B is pushed forward by a propulsion jack E in the same manner as described above, so that the small bore tube B is excavated by the tunnel excavator A. To promote. In the same manner, each time the tunnel excavator A excavates for a certain length, the small-diameter pipe B is connected.
[0029]
  The earth and sand excavated by the rotary excavator 2 of the tunnel excavator A is a sediment chamber.4It is taken in. At this time, in the case of large block soil, it is crushed finely by the inner cone 2b and the outer cone 2c, and the earth and sand chamber4Take it in and muddy it. If the excavated sediment is not mud,4Inject a suitable amount of muddy water into the earth and sand chamber4The soil inside is made into uniform mud.
[0030]
  The excavated sediment is a sediment chamber4It is excavated by the rotary excavation part 2 while the face is suppressed by the pressure and the face ground is prevented from collapsing. This earth and sand room4The mud pressure inside is4This is performed by adjusting the opening degree of the air pinch valve 7 connected in direct communication with the rear end discharge port 5 and mud is sent from the discharge port 5 to the air pinch valve 7 side by the mud pressure. At this time, earth and sand room4Since the length of the soil discharge port 5 and the front side connecting short pipe 16 which is a mud extruding passage from the air to the air pinch valve 7 is extremely short,4A predetermined amount of excavated earth (mud) can be sent into the air pinch valve 7 reliably and smoothly by the mud pressure inside. The opening degree of the air pinch valve 7 is adjusted by supplying compressed air through the hose 7E.7BThis is done by reducing the width between the opposing surfaces and expanding the width by eliminating the compressed air.
[0031]
The excavated earth and sand sent from the discharge port 5 into the air pinch valve 7 through the front connection short pipe 16 of the air pinch valve 7 is connected to the rear side connection short pipe 17 of the air pinch valve 7. The short pipe 17 is fed through the through hole 11 into which the short pipe 17 is rotatably inserted, and is sent out to the earth discharging pipe 8 having the front end portion inserted into the through hole 11, and communicated in series with the earth discharging pipe 8 from the earth discharging pipe 8. It is discharged to the start shaft C side through the earth and sand discharge pipe in the small-diameter pipe body B. This earth and sand is discharged by operating a vacuum pump installed on the start shaft C side to generate a suction force in the earth discharge pipe 8 through the earth and sand discharge pipe, and the above-mentioned excavated earth and sand reaching the air pinch valve 7 by the suction force. It is carried out by taking it into the earth discharge pipe 8.
[0032]
In this way, the excavated soil in the earth and sand chamber 4 is excavated in the front ground by the tunnel excavator A while being sent rearward from the discharge port 5 through the air pinch valve 7 and the exhaust pipe 8. In some cases, mud mud that is excavated soil may erupt from the connecting short pipe portion due to clogging of excavated soil, a sudden increase in mud pressure on the sediment chamber 4 side, or damage to the air pinch valve 7. However, since the air pinch valve 7 including the front and rear connecting short pipes 16 and 17 is disposed in the valve installation chamber 6 surrounded by the waterproof cover 12, the partition wall 3 and the partition wall 9, It stays in the valve installation chamber 6 and does not scatter into the device installation chamber 10 outside the waterproof cover 12, but the devices 23 to 25 and various parts arranged in the device installation chamber 10 There is no risk of fouling.
[0033]
When repairing or replacing the air pinch valve 7, after removing the closing plate 14 closing the opening 13 of the valve installation chamber 6, the front and rear connecting short pipes 16, 17 of the air pinch valve 7 are removed. The flange portions 16a and 17a are separated from the front and rear flange portions 7a and 7a of the casing 7A of the air pinch valve 7 by removing the plurality of bolts 15 connecting and fixing the flange portions to each other. The casing 7A and the front and rear connecting short pipes 16 and 17 are separately taken out from the valve installation chamber 6, and the air pinch valve 7 is repaired or replaced with a new air pinch valve.
[0034]
When the air pinch valve 7 is removed, the front and rear connection short pipes 16 and 17 are rotatably inserted into the earth discharge port 5 provided in the partition wall 3 and the through-hole 11 provided in the partition wall 9 respectively. The front and rear flanges 7a and 7a of the air pinch valve 7 and the flanges 16a and 17a of the front and rear connecting short pipes 16 and 17 are connected to a plurality of bolts 15 that connect a plurality of circumferential positions. The connecting short tubes 16 and 17 are rotated and sequentially moved to the front side, that is, the opening 13 side of the valve installation chamber 6 to perform the bolt removing operation reliably and smoothly. The air pinch valve 7 can be taken out of the valve installation chamber 6 by removing either one of the casings 7 </ b> A of the air pinch valve 7 without removing the front and rear connecting short tubes 16 and 17.
[0035]
In order to arrange the air pinch valve 7 thus repaired or a new air pinch valve 7 in the valve installation chamber 6, first, the front short connecting pipe 16 is inserted into the earth discharge port 5 and the air is inserted. The pinch valve 7 is inserted into the valve installation chamber 6 and the front flange portion 7a of the air pinch valve 7 is connected to the flange portion 16a of the connecting short tube 16 with a bolt 15, and then the front connecting short tube 16 is discharged. The gap between the rear end of the air pinch valve 7 and the front end face of the through-hole 11 is widened with the opening 5 being inserted into the opening 5, and the rear connecting short pipe 17 is inserted into this gap so that the flange portion 17 a is inserted. It is connected to the rear flange portion 7a of the air pinch valve 7 with a bolt 15, and then the rear connection short tube 17 is inserted into the through hole 11 while the front connection short tube 16 is retracted. Also in this case, the operation of connecting with the bolts 15 can be performed easily and efficiently by rotating the air pinch valve 7 and sequentially moving the bolt connecting holes of the flange portions to be connected to the front side. The air pinch valve 7 is attached to the air pinch valve 7 previously connected to the rear connection short pipe 17 with a bolt 15 in the valve installation chamber in which the front connection short pipe 16 is inserted. You may do it.
[0036]
The air pinch valve 7 can be repaired or replaced before excavating the tunnel or in the shaft after excavating the tunnel. If the air pinch valve 7 breaks down during excavation of the tunnel, Once the tunnel excavator A is pulled back to the start shaft C side, it is performed in the start shaft C. The tunnel excavator A is a small-diameter excavator having a diameter of 30 to 60 cm as described above, and the depth of the recessed portion of the waterproof cover 12 reaching the rotary shaft 2a from the space of the valve installation chamber 6, that is, the skin plate 1. Therefore, the flanges of the air pinch valve 7 and the connecting short pipes 16 and 17 cannot be fully accommodated in the valve installation chamber 6, so that the upper and lower parts of these flanges are horizontally placed as shown in FIG. 33 has been excised. In this case, since the front and rear connecting short pipes 16 and 17 are configured integrally with the air pinch valve 7 so as to be rotatable with respect to the soil discharge port 5 and the through hole 11, the upper and lower cut portions formed in the flange portion. 33 can be surely positioned in a state where the narrow space is directed to the rotating shaft 2a side and the skin plate side.
[0037]
In the above embodiment, the partition wall 3 is used as the front wall of the valve installation chamber 6 and the partition wall 9 is used as the rear wall. However, the present invention is not limited to this, and the front and rear walls of the valve installation chamber 6 are separated from the partition walls and partition walls. You may provide independently, without combining. Further, in the above-described embodiment, it has been described that the front and rear connection short pipes 16 and 17 are also removed and reattached when the air pinch valve 7 is repaired or replaced, but the present invention is not limited to this, and the front and rear connection The short pipes 16 and 17 may be left in the tunnel excavator and only the air pinch valve 7 may be taken out and reattached. In this case, it is necessary to limit the length of the front and rear connection short pipes 16 and 17 in particular. It is sufficient that at least one of the connecting short pipes can be moved back and forth.
[0038]
【The invention's effect】
As described above, according to the tunnel excavator of the present invention, as described in claim 1, the cylindrical skin plate, the partition wall disposed in the front portion of the skin plate, and the front end of the skin plate in front of the partition wall A rotary excavation part disposed in the opening, a earth and sand chamber formed between the rotary excavation part and the bulkhead, and a soil discharge pipe for discharging the earth and sand in the earth and sand chamber sent out through a drainage port provided in the bulkhead to the rear The valve excavator is provided on the rear side of the earth opening provided in the partition wall, and a valve installation chamber is formed by a waterproof cover that is cut off from the skin plate outside the waterproof cover. A connecting short pipe is integrally connected to the front and rear opening ends of the valve installed in the installation chamber, and the front connecting short pipe communicates with the earth discharge port, and the rear connecting short pipe communicates with the front end of the earth discharging pipe. So the valve directly at the discharge port So that communicated structure, the mud through the soil discharge port by mud pressure in the soil chamber can be fed reliably to within the valve.
[0039]
Furthermore, since the valve installation chamber is shielded from the inside of the skin plate outside the waterproof cover by the waterproof cover, mud from the short pipe connecting part before and after the valve due to a sudden increase in mud pressure during excavation by the tunnel excavator. Even if it erupts into the valve installation chamber, it can prevent mud from scattering or flowing into the skin plate at the rear of the bulkhead where equipment and many parts are installed. There is no risk of fouling.
[0040]
Further, according to the invention according to claim 2, since the valve installation chamber is structured to be exposed to the outside of the skin plate through an opening formed in a part of the skin plate, the valve needs to be repaired or replaced. Sometimes, regardless of the equipment installed in the skin plate, only the valve can be easily taken out from the outside of the skin plate through the opening, and the repair and replacement work can be done easily. Even during this operation, the leaked mud is not discharged from the valve installation chamber to the outside of the skin plate, and the interior of the machine is not soiled.
[0041]
According to the invention of claim 3, the front connection short pipe and the rear connection short pipe of the valve are formed in the through hole provided in the partition wall that forms the rear wall of the earth discharge port and the valve installation chamber. Insert and remove the front and rear connection short pipes with respect to the soil outlet and the through hole by inserting them in a rotatable manner and forming either one of the short connection pipes longer than the other short connection pipe and moving the valve in the pipe axis direction. Since the valve can be attached and removed from the outside of the skin plate easily and reliably, the bolts that fasten the valve body and the front and rear connection short pipes can be removed and fastened with bolts. Work can be performed efficiently and workability is remarkably improved.
[Brief description of the drawings]
FIG. 1 is a longitudinal side view of a tunnel excavator,
FIG. 2 is a longitudinal front view of the front skin plate portion,
FIG. 3 is a simplified vertical side view of an air pinch valve;
FIG. 4 is a simplified side view showing a tunnel construction state.
[Explanation of symbols]
1 Skin plate
2 Rotary excavation part
3 Bulkhead
4 earth and sand room
5 earth exit
6 Valve installation room
7 Air pinch valve
8 Drainage pipe
9 Partition wall
10 Equipment installation room
11 Through hole
12 Waterproof cover
16, 17 Connection short pipe

Claims (3)

A cylindrical skin plate, a partition wall disposed in front of the skin plate, a rotary excavation unit disposed in a front opening of the skin plate in front of the partition wall, and formed between the rotary excavation unit and the partition wall. A tunnel excavator, and a drain excavator for discharging the earth and sand in the earth and sand chamber sent out through the earth discharge port provided in the partition wall to the rear, the rear of the earth discharge port provided in the partition wall A valve installation chamber that is cut off from the inside of the skin plate is formed on the side, and a connection short pipe is integrally connected to the front and rear opening ends of the valve installed in this valve installation chamber to connect the front connection short pipe to the rear side A tunnel excavator characterized in that a short pipe communicates with the earth discharge port and the earth discharge pipe.   The tunnel excavator according to claim 1, wherein the valve installation chamber faces the outside of the skin plate through an opening formed in a part of the skin plate. The valve rear connection short pipe is rotatably inserted into a through hole provided in the rear wall of the valve installation chamber, and the valve front connection short pipe is rotatably inserted into a discharge port provided in the front wall of the valve installation chamber. The tunnel excavator according to claim 1, wherein one of the short connecting pipes is configured to be movable in the pipe axis direction.

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