JPS6126468Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a shield excavator suitable for excavating ground where the strata change.

When excavating a tunnel with a shield excavator,
Depending on the method of stabilizing the face, it is classified into mud shield method, mud shield method, earth pressure shield method, etc., and the method is selected depending on the ground condition, such as silt ground, sandy ground, gravel ground, etc. , has been adopted.

However, the actual ground does not form a homogeneous stratum, and selecting and deciding on one method before launching the shield and excavating the entire length of the tunnel using the same method would result in reaching ground other than the geology suitable for that method. This has the problem that sometimes smooth excavation cannot be performed.

The present invention has been developed in view of these problems, and the object is to provide a shield excavator that can switch to a mud shield method, an earth pressure shield method, etc. depending on the changing geology during excavation.

The embodiments of the present invention will be explained with reference to the drawings: 1
The cutter head 3 is attached to the front end side of the skin plate 2.
The outer circumferential surface of the partition wall 4 is integrally fixed to the inner circumference of the skin plate 2 at an appropriate distance from the back surface of the cutter head 3, so that the front surface of the partition wall 4 and the skin plate 2 are connected to each other. A pressure chamber 5 is formed between the rear surfaces of the partition wall 4 and an operator's cab 6 is provided on the rear side (atmospheric side) of the partition wall 4 .

Further, the outer peripheral portion of the partition wall 4 is formed into a circumferential step portion 7 that protrudes forward.

Reference numeral 8 denotes a stepped cylinder whose front end is integrally fixed to the outer periphery of the back surface of the cutter head 3. Its rear portion is formed into a small diameter cylindrical portion 8a, and the outer periphery of the small diameter cylindrical portion 8a is connected to the inner periphery of the skin plate 2. The thrust bearing 1 is rotatably supported by a bearing 9 fixed to the
0 is inserted. Further, the stepped cylinder 8 has water-stop gaskets 11 and 12 disposed between the inner circumferential surface of the skin plate 2 and the outer circumferential surface of the large-diameter cylindrical portion, and between the inner circumferential surface of the small-diameter cylindrical portion and the outer circumferential surface of the stepped portion of the partition wall 4, respectively. It is in watertight and rotatable sliding contact with the outer circumferential surfaces of the circumferential portions of the skin plate 2 and the partition wall 4 via etc.

Reference numeral 13 denotes a drive device such as a motor attached to the outer periphery of the rear surface of the partition wall 7, and its rotating shaft projects toward the front side of the partition wall 4, and a pinion 14 fixed to the projecting end is connected to the outer periphery of the small-diameter cylindrical portion of the stepped cylinder 8. Rack 1 stuck to the surface
5 to rotate the cutter head 3.

Reference numeral 16 designates an inner cutter head whose outer circumferential surface is in rotatable sliding contact with the inner circumferential surface of the front end of the small diameter cylindrical portion 8a of the stepped cylinder 8 via a packing 17. It is divided into a chamber 5a and a rear pressure chamber 5b, and the rotation shaft 18 of the cutter head 16 is connected to the partition wall 4.
The rotary shaft 18 is rotatably supported in the center of the driver's cab 6 and is rotated by a drive device 19 such as a motor provided on the driver's cab 6 side.

The inner cutter head 16 has slits 20 formed in the form of elongated holes in the radial direction, and cutter blades 21 are attached to these slits 20.
The slit 20 can be opened and closed by a cutter gate 23 which is rotated by a cylinder 22 attached to the back of the cutter head 16.
Through holes 24, 24 are bored through which a sludge drainage pipe can be inserted, and these through holes 24, 24 can also be opened and closed by a gate 26 which is rotated by a cylinder 25.

Reference numerals 27 and 28 denote a sludge feeding pipe and a sludge draining pipe, which penetrate the partition wall 4 at appropriate locations opposite to the through holes 24 and 24 and have their tips communicated with the pressure chamber 5, respectively. The short pipes 29, 29 are fitted watertightly and slidably into the inner peripheral surfaces of the short pipes 29, 29, which are watertightly and slidably fitted into the muddy water treatment equipment (not shown) installed on the ground and the pressure chamber 5.
Mud water is circulated between the two via a mud pump (not shown).

Further, the tip end of another mud feeding pipe 30 is slidably penetrated in a watertight manner at an appropriate location of the partition wall 4, and the leading end is communicated with the pressure chamber 5, and the rear end is connected to muddy water treatment equipment. It has been done.

Reference numerals 31, 32, and 33 designate cylinders whose one end is connected to the rear surface of the partition wall 4, and whose rod tips are connected to appropriate positions of the feeding and mud removal pipes 27, 28 and another mud feeding pipe 30, respectively. 32 is contracted, and the tips of the sludge removal pipes 27 and 28 are passed across the rear pressure chamber 5b to the inner cutter head 1.
6 and facing the front pressure chamber 5a.
7 and 28 are in communication with the rear pressure chamber 5b, by advancing another mud feeding pipe 30 by the cylinder 33, the tip of the mud feeding pipe 30 is opened through the hole 24.
The front pressure chamber 5a is configured to be able to communicate with the front pressure chamber 5a by penetrating through the front pressure chamber 5a.

To describe the operation of the shield excavator configured as described above, when the excavated ground 34 is suitable for the earth pressure shield method, first, the cylinders 31, 3
2 and 33 are extended and fed, and the distal ends of the mud removal pipes 27 and 28 and another mud feeding pipe 30 are retreated to the vicinity of the partition wall 4 to communicate with the rear pressure chamber 5b and the inner cutter head 16. The through holes 24, 24 provided in the holes 24 and 24 are closed.

Next, the mud water pump is operated to fill the pressure chamber 5 with mud water through the mud feed pipe 27, and while circulating the mud water between the pressure chamber 5 and the above-ground processing equipment through the mud removal pipe 28, pressure such as water pressure on the ground side is reduced. and balance it. In this state, when the cutter head 3 is rotated by the drive device, the excavated earth and sand enters the front pressure chamber 5a through the earth and sand intake port (not shown) provided in the cutter head 3, and is absorbed by the earth and sand. Front pressure chamber 5
The muddy water inside a is discharged into the rear pressure chamber 5b through the slits 20, 20, while filling the front pressure chamber 5a.

In this way, the earth pressure generated in the front pressure chamber 5a is balanced with the earth pressure of the ground 34, thereby preventing the ground from collapsing.

In this state, use the cutter head 3 to cut the ground 3.
When the inner cutter head 16 is rotated by the drive device 19 while excavating the cutter head 4, the earth and sand in the front pressure chamber enters the rear pressure chamber 5b through the slit 20 of the inner cutter head 16 while maintaining a constant earth pressure, and is refluxed. The mud is transported and discharged to treatment facilities outside the mine.

At this time, in order to keep the inside of the front pressure chamber 5a at a constant earth pressure, the earth pressure is measured by an appropriate means and the number of rotations of the inner cutter head 16 or the opening and closing of the slit 20 by the gate 23 opened and closed by the cylinder 22 is adjusted. Adjust the opening and open the inner cutter head 1
Adjust the excavated soil intake speed according to step 6. Furthermore, the static pressure of the reflux mud is maintained at approximately the same pressure as the groundwater pressure.

Next, when the ground suitable for the mud shield method is encountered during shield excavation, the excavation work described above is stopped, and the gate 2 of the inner cutter head 16 is
6 is opened by the operation of the cylinder 25 to open the through hole 2.
4 and 24 are opened, and only the mud feeding pipe 30 is moved forward by the operation of the cylinder 33 and inserted into one of the through holes 24, so that its tip portion faces the pressure chamber 5a.

In this state, when mud is injected and supplied into the front pressure chamber 5a through the mud feeding pipe 30 and the cutter head 3 is rotated to excavate the ground 34, the excavated soil that has entered the front pressure chamber 5a turns into mud. The soil is disturbed and mixed to form muddy soil, and this muddy soil flows through the slit 20 of the inner cutter head 16 where it is stopped.
The slurry is extruded into the rear pressure chamber 5b through the through hole 24, and is discharged to the treatment equipment by the muddy water flowing back through the mud feeding and draining pipes 27 and 28.

Next, when ground suitable for the mud shield method is encountered, the excavation work is stopped, and the through holes 24, 24 of the inner cutter head 16 are opened,
Operate the cylinders 31 and 32 to send the sludge to the drainage pipe 2.
7 and 28 are inserted through the through holes 24 and 24, respectively, so that their tips communicate with the front pressure chamber 5a.

When the slurry is fed in this state and the mud is returned through the mud removal pipes 27 and 28, the front pressure chamber 5a becomes a pressure chamber filled with mud, and the mud water pressure stabilizes the face. In this case, whether the static pressure of the return mud by the mud pump is equal to the earth pressure at the face and the groundwater pressure,
Pressurize and adjust to a slightly higher pressure.

Next, with the inner cutter head 16 stopped, only the front cutter head 3 is moved by the drive device 13.
When the cutter head 3 is rotated, the earth and sand excavated by the cutter head 3 is transported from the front pressure chamber 5a to an outside treatment facility by the return mud water, and thus can be excavated as a mud shield method.

In addition, in the above embodiment, the feed and sludge removal pipes 2
7, 28 are moved in the length direction to selectively communicate their tips with the front and rear pressure chambers 5a, 5b, but as shown in FIG.
The mud draining pipes 27 and 28 are fixed to the partition wall 4 with their tips protruding into the rear pressure chamber 5b, while the inner cutter head 16 is slid back and forth by a cylinder 35 connected between the partition wall 4 and the drive device 19. When the inner cutter head 16 is brought into close contact or close to the front surface of the bulkhead, the feeding and draining pipes 27 and 28
The tip end of the front pressurizing chamber 5a may be communicated with the front pressurizing chamber 5a, and the other configurations are the same as those of the previous embodiment.

As described above, the present invention provides a cutter head at the front end of the shielding machine main body, and an inner cutter head is provided in the pressure chamber formed between the cutter head and the partition wall provided inside the shielding machine main body, and the pressure chamber is advanced through the inner cutter head. The sludge is divided into a pressure chamber and a rear pressure chamber, and the sludge is fed into the pressure chamber from the partition wall, facing the open end of the sludge feed pipe, and fed to the inner cutter head, into which the open end of the sludge removal pipe can be inserted. A through hole is bored, and the inner cutter head and the feed and mud removal pipes are moved relatively toward and away from each other, and the open end of the mud removal pipe is selectively communicated with the front pressure chamber and the rear pressure chamber. This is related to a shield excavator characterized by a structure that allows excavation to be carried out by changing to the earth pressure type, mud type, or mud water type shield method depending on the stratum even if the ground condition changes during excavation. Moreover, the change can be easily made by simply moving the inner cutter head and the feed and mud removal pipes toward and away from each other. Accordingly, tunnels can be excavated safely, and tunnels can be excavated smoothly and efficiently using one type of excavator.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention; FIG. 1 is a longitudinal sectional side view thereof, FIG. 2 is a front view of the inner cutter head, and FIG. 3 is an enlarged sectional view of the slit portion thereof.
FIG. 4 is a longitudinal sectional side view showing another embodiment of the present invention. 1... Shield machine body, 3... Cutter head, 4... Partition wall, 5... Pressure chamber, 5a... Front pressure chamber, 5b... Rear pressure chamber, 16... Inner cutter head, 24... Through hole, 27, 28... feeding, sludge drainage pipe.

Claims (1)

[Scope of utility model registration request] A cutter head is provided at the front end of the shield machine main body, and an inner cutter head is provided in a pressure chamber formed between the cutter head and a partition wall provided inside the shield machine main body, and the pressure chamber is divided into a front pressure chamber and a rear pressure chamber through the inner cutter head. The sludge is further divided into two parts, and then sent into the pressure chamber from the partition wall, facing the open end of the sludge removal pipe, and sent to the inner cutter head. and a sludge removal pipe, the sludge removal pipe is relatively connected to and separated from the sludge removal pipe, and the open end of the sludge removal pipe is selectively communicated with a front pressure chamber and a rear pressure chamber. excavator.