JP3282282B2 - Shield machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shield machine suitable for underground docking.

[0002]

2. Description of the Related Art In tunnel excavation, when the length of a tunnel is long, there is a construction method in which two excavators are excavated from the beginning and end of the tunnel so as to face each other, and docked at an intermediate point. In this case, as shown in FIG. 5, two excavators a are brought into contact with each other and abutted against each other.
The hood cylinder c covered by the shield frame b is pushed forward, and the connection between the excavators a is covered with the hood cylinder c.
Thereby, collapse of the face can be prevented, and spring water from the side ground is stopped. Thereafter, the cutters d and the motors of the two excavators a are sequentially disassembled and removed to connect the shield frames b.

The pushing of the hood cylinder c is performed as follows. As shown in FIG. 6, first, a work hole e is opened from the inside at the portion where the hood tube c of the shield frame b overlaps, and a support f is attached to the inside of the exposed hood tube c by welding or the like. Then, a jack g for pushing out a hood tube attached to the shield frame b is connected to the support f, and the hood tube c is pushed forward by extending the pushing jack g.

[0004]

However, in this case, the extrusion stroke of the hood cylinder c is limited by the stroke of the extrusion jack g and the hole diameter of the working hole e, and the hood cylinder c must be pushed out by a required length. May not be possible. As a countermeasure, it is conceivable that after the hood cylinder c is once pushed out to the limit, the column f is cut off from the hood cylinder c, re-welded to the near side (the extrusion jack g side), and extruded by a small stroke like a scaleworm. However, it is not preferable because the number of steps increases and the work becomes complicated.

When the work hole e is formed in the shield frame b, there is a possibility that spring water from the side ground may erupt through the gap between the hood cylinder c and the shield frame b. In this case, not only is the inside of the shield frame b soiled, but also
There is a possibility that the balance of earth pressure and water pressure at the face will be lost and the face will collapse.

SUMMARY OF THE INVENTION An object of the present invention, which has been made in view of the above circumstances, is to provide a shield excavator that can extrude a hood cylinder with a long extrusion stroke and is excellent in workability and safety.

[0007]

In order to achieve the above object, the present invention relates to a shield excavator for excavating the ground by rotating a cutter provided on the front surface of a cylindrical shield frame. A hood cylinder is slidably fitted to the hood cylinder, a helical screw groove is provided on the inner peripheral surface of the hood cylinder along the axial direction, and a pin that engages with and disengages from the screw groove is provided on the cutter so as to be freely retractable. It is characterized by.

[0008]

When the hood cylinder is pushed out, the cutter is rotated after the pin of the cutter is projected to engage with the thread groove of the hood cylinder. Then, the hood cylinder is fed in the axial direction with the rotation of the cutter by the action of the spiral screw groove.

In addition, during normal excavation, if the pin of the cutter is retracted, the association between the cutter and the hood cylinder is lost, so that the hood cylinder does not move due to the rotation of the cutter. Therefore, there is no hindrance to ordinary excavation.

[0010]

An embodiment of the present invention will be described with reference to the accompanying drawings.

As shown in FIG. 1, a cutter 2 for excavating a ground (face) is rotatably provided on the front surface of a cylindrical shield frame 1. The cutter 2 is driven to rotate by a motor (not shown) and takes excavated earth and sand into the cutter chamber 3 on the back of the cutter. The cutter chamber 3 is separated from the pit 5 by a partition wall 4, and the earth and sand taken into the cutter chamber 3 is discharged into the pit 5 by a screw conveyor or the like.

A hood tube 6 slightly larger in diameter than the shield frame 1 is slidably fitted around the outer periphery of the shield frame 1. The hood cylinder 6 is provided so as to surround the cutter chamber 3, and a part thereof is exposed in the cutter chamber 3. The rear end of the hood cylinder 6 is supported by a stopper 7 welded to the shield frame 1, thereby supporting a load applied to the hood cylinder 6 by the earth pressure of the face during normal excavation. The stopper 7 is formed in a ring shape along the outer periphery of the shield frame 1.

On the inner peripheral surface of the hood cylinder 6, several thread grooves 8 are engraved along its axial direction. The number of threads and the pitch of the thread groove 8 are appropriately determined by the extrusion stroke of the hood cylinder 6. The screw groove 8 has a back surface 2 a of the cutter 2.
The pin 9 provided on the base is disengaged. The pin 9 is provided on a stirring blade 10 provided on the cutter back surface 2a so as to be able to protrude and retract radially outward by a hydraulic jack 11. According to this configuration, if the cutter 2 is rotated in a state where the pins 9 are projected and engaged with the screw grooves 8 as shown in FIG. 3, the hood is rotated with the rotation of the cutter 2 as shown in FIG. The tube 6 is screwed in the axial direction.

At this time, if the hood cylinder 6 rotates with the rotation of the cutter 2, the hood cylinder 6 is not fed by screw.
Therefore, it is necessary to prevent the hood cylinder 6 from rotating by some means. In this embodiment, as shown in FIG.
A key groove 12 is engraved in the inner peripheral surface along the axial direction, and a key 13 is provided on the outer peripheral surface of the shield frame 1. The key groove mechanism 14 prevents the rotation of the hood cylinder 6. The key groove 12 and the key 13 are provided in the circumferential direction at an interval of 90 degrees at about four positions. The keyway 12 is
It may be provided on the rear side 6b separately from the screw groove 8, or may be provided on the screw groove 8 in a superimposed manner.

At the outer end of the cutter 2, a copy cutter 15 for excavation is provided so as to be able to protrude and retract. The copy cutter 15 protrudes to a position corresponding to the outer diameter of the hood cylinder 6 to reduce the resistance applied to the front end of the hood cylinder 6 during excavation.

The operation of this embodiment having the above configuration will be described.

When the hood cylinder 6 is pushed out, as shown in FIG. 3, a pin 9 provided on the agitating blade 10 of the cutter back part 2a is projected radially outward to engage with the thread groove 8 of the hood cylinder 6. Then, the cutter 2 is rotated. Then, since the rotation of the hood cylinder 6 is suppressed by the key groove mechanism 14, the screw is fed forward in the axial direction with the rotation of the cutter 2 by the action of the helical screw groove 8 as shown in FIG. You. At this time, the copy cutter 15 is housed in the cutter 2 before rotating the cutter 2 so as not to hinder the pushing of the hood cylinder 6.

The extrusion stroke of the hood cylinder 6 can be easily lengthened by increasing the number of thread grooves 8 engraved on the inner peripheral surface of the hood cylinder 6 and increasing the pitch. Therefore, FIG.
No limitation is imposed by the stroke of the extrusion jack g and the hole diameter of the working hole e as in the prior art shown in FIG. Further, since the extrusion stroke of the hood cylinder 6 can be accurately calculated based on the rotation speed of the cutter 2, it is possible to accurately match the excavation stroke with the counterpart excavator at the time of docking.

In addition, when the hood cylinder 6 is extruded, it is not necessary to drill the working hole e or weld the support f, which has been conventionally performed. Therefore, it is possible to shorten the work period and reduce the work cost, and to work safely. The performance is also improved. That is, in the present embodiment, an extremely simple operation of engaging the pin 9 with the screw groove 8 and rotating the cutter 2 by remote control using hydraulic pressure is sufficient. Further, a new extrusion jack g or the like is not required at all, and can be easily realized at low cost by making a small modification to an existing excavator.

During normal excavation, as shown in FIG.
The pin 9 is pulled into the stirring blade 10 and is separated from the screw groove 8. Thereby, the association between the cutter 2 and the hood cylinder 6 is lost, so that the rotation of the cutter 2 does not move the hood cylinder 6. Therefore, there is no hindrance to ordinary excavation.

Further, the copy cutter 15 is projected to a position corresponding to the outer shape of the hood cylinder 6. This reduces the resistance of the front end of the hood cylinder 6 from the face. In addition, the stirring blade 10 into which the pin 9 is drawn in stirs the earth and sand in the cutter chamber 3 with the rotation of the cutter 2, and makes the screw conveyor to discharge the soil well.

The present invention is not limited to the above embodiment, and various changes can be made without departing from the scope of the invention. For example, the present invention may be applied to docking with an existing shaft.

[0023]

As described above, according to the present invention, the following excellent effects can be exhibited.

(1) The extrusion stroke of the hood cylinder can be lengthened.

(2) The extrusion stroke of the hood cylinder can be accurately controlled.

(3) It is possible to shorten the working time, reduce the cost, and improve the safety.

(4) It can be easily applied to existing excavators.

[Brief description of the drawings]

FIG. 1 is a side sectional view of a main part of a shield machine showing an embodiment of the present invention (during excavation).

FIG. 2 is a side sectional view of a main part of the shield machine (when a hood cylinder is pushed out).

FIG. 3 is a side sectional view showing pins and screw grooves of the shield machine.

FIG. 4 is a partial cross-sectional view of the shield machine in a direction perpendicular to an axial direction.

FIG. 5 is a diagram showing a state of docking of shield excavators.

FIG. 6 is an explanatory view showing a conventional hood cylinder pushing device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Shield frame 2 Cutter 6 Hood cylinder 8 Screw groove 9 pin

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-3-202588 (JP, A) JP-A-4-12592 (JP, U) JP-A-5-50108 (JP, U) (58) Investigated Field (Int.Cl. ⁷ , DB name) E21D 9/06 301 E21D 9/06 302

Claims (1)

(57) [Claims] 1. A shield excavator for excavating the ground by rotating a cutter provided on the front surface of a cylindrical shield frame, wherein a hood cylinder is slidably fitted on the shield frame. A shield excavator, wherein a spiral screw groove is provided on an inner peripheral surface along an axial direction, and a pin that engages with and disengages from the screw groove is provided on the cutter so as to be freely retractable.