JPS5915188A - Intermediate folding type shield excavator - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a folding type shield excavator that can easily perform curved excavation with a small radius of curvature.

Shield tunneling machines are widely used as the safest tunneling machines when constructing tunnels in soft ground, especially in water-logged sand and gravel layers, and are designed to apply a lining to the tunnel as the excavation progresses. ing. This lining is assembled by a series of axially abutting rings made up of a plurality of segments joined in a circular, semicircular, horseshoe, etc. shape.

By the way, when excavating urban tunnels for water supply, sewage, subway, power, and communication cables, curved excavation with a relatively small radius of curvature is required due to constraints such as location conditions. A so-called center-folding type shield excavator is used in which the rear shield is divided into two parts and these parts are connected in a bendable manner. Conventional folding type shield tunneling machines operate the shield jack on the outside of the curve to propel the front shield, and then operate the shield jack on the inside of the curve to pull the rear shield to move forward. , the reaction force of each shield jack at this time is taken up by the front shield. therefore,
According to such a center-folding type shield tunneling machine, it is possible to advance with a smaller radius of curvature compared to an integrated type tunneling machine, and the amount of over-drilling can be reduced, making it possible to prevent collapse of the ground. It has the great advantage of being able to form sharp edges by reducing the amount of backfilling.

However, in this type of center-folding type shield excavator, there is no problem because the segments are used as a reaction force when moving the front shield forward, but when the rear shield is moved forward, they are used as a reaction force. The front shield moved easily, making it difficult to control the direction of the rear shield. Also, depending on the ground conditions in the construction section, if the ground itself is self-supporting such as a loam layer, or if the construction is carried out using shoring, etc., the reaction force may need to be obtained from something other than the segments. Ta.

The present invention has been made in view of the above-mentioned points, and is a center-folding type that can reliably obtain a reaction force on a free-standing ground, etc., and can easily and reliably control the direction of the shield body. This product provides a shield tunneling machine, and its features are that the front shield and rear shield are bendable and relatively slidable when moving forward, and a shield jack is placed at the connecting part. one end thereof is fixed to the front shield, the other end is connected to the rear shield during forward movement of the shields, and within both shields are first and second gripper jacks, respectively, which operate alternately during forward movement of these shields. When the front shield moves forward, the second grit and jack actuates to fix the rear shield to the tunnel peripheral wall, so that the shield forms the reaction force of the shield jack, and the rear shield When the vehicle moves forward, the first gripper jack operates to fix the front shield to the tunnel peripheral wall, and the shield jack pulls the rear shield forward.

Hereinafter, the present invention will be described in detail based on embodiments shown in the drawings.

FIG. 1 is a vertical cross-sectional view showing an embodiment of the folding type shield excavator according to the present invention, FIG. 2 is a half-sectional view taken along the line ■-■ in FIG.
Figure 3 is an enlarged sectional view taken along the line m-m in Figure 1, Figures 4 and 5.
The figures are a sectional view taken along lines IV--IV and v-v in FIG. 3, and FIG. 6 is an enlarged side view showing the structure of the tip of the shield jack. In FIG. 1, the center-folding type shield excavator 1 is
1 includes a front shield 2 and a rear shield 3, each of which is a cylindrical body formed in the same shape and open at both ends, and both shields 2.3 are connected in a bendable manner to form a center-folding type shield. It constitutes the main body of the excavator. In this case, both shields 2.3 connect the small diameter portion 4 provided at the front end of the rear shield 3 to the front shield 2.3 as shown in FIG.
A plurality of shield connectors 6 are slidably inserted into the inner circumferential surface of the rear end through shield packings 5 and provided on the front shield 2 side, and correspondingly provided on the rear shield 3. Connecting pins 8 are removable at each connecting part T.
(See FIG. 1), they are integrally connected to each other. Therefore, the effective grounding length l of the rear shield 3 with respect to the tunnel peripheral wall is shorter than that of the front shield 2 by approximately the length of the small diameter portion 4 to the right.

At the center of the interior of the front shield 2, an excavator 10 with a cutter portion 10A protruding forward to excavate a face portion 12 on the front surface of the shield, and an operation room 11 for operating the excavator 10 are disposed. . The excavator 10 is configured to be rotated forward and backward in a circular pattern around its rear end, and the cutter portion 10A is rotatably driven in a telescopic manner. The earth and sand excavated by the excavator 10 is conveyed rearward by a belt conveyor 13 disposed inside the shield excavator body and discharged to the outside of the tunnel. When excavating the face part 12 in front of the shield, the face 1
In the case of hard geology where the shield 2 can stand on its own, excavation can be carried out without any problem, but in the case of soft ground where the face 12 collapses, not only the inflow of earth and sand into the shield, but also the ground subsidence. In order to prevent this, a movable hood jack 14. A half-moon jack 15 and the like are arranged on the front end side ceiling surface of the front shield 2.

On the other hand, a well-known ring gate type segment erector device 18 is disposed inside and rearward of the rear shield 3.

This segment erector device 18 is rotatably supported by a plurality of rollers 19 arranged concentrically inside the rear shield 3, and includes an erector ring 20 driven by a turning motor (not shown). An erector 22 is disposed on the ring 20 to assemble the lining 21 as the tunnel is excavated. Said lining 2
1 is an arc-shaped segment 21a, 21b, 21°, etc. made of iron, concrete, etc. divided into six parts, for example.
・Constructed by joining in a ring shape, each segment 2
1a, 21b, 21a, . . . are successively suspended by the erector 22, positioned at a predetermined position by the rotation of the erector ring 20, and then pressed against the inner circumferential wall of the rear shield 3 and assembled.

Then, the assembled backing sheets 21 are successively joined in series with a backfilling material such as mortar, and as the rear shield 3 moves forward, it is sent into the tunnel through the rear end opening of the shield 3. A tail packing 25 is disposed around the entire circumference of the tail inner circumferential wall of the rear shield 3, and the outer circumferential surface of the lining sheet 21 slides thereon to prevent muddy water and the like from entering.

A plurality of shield jacks 2T (only one is shown in FIG. 1) extend in the front-rear direction along the inner circumferential wall of the small diameter portion 4 at the connecting portion A between the front shield 2 and the rear shield 3. The jack bodies 27a are arranged in parallel and equally spaced in the circumferential direction of the small diameter portion 4, and the front end surface of each jack body 27a is fixedly held on the rear wall 28a of the gripper storage box 2B provided on the inner peripheral wall of the front shield 2. ing. On the other hand, a screw hole 29 is formed in the outer end surface of the shield jack rod 27b which is slidably fitted into the jack main body 27a of each shield jack 27, as shown in FIG. A male threaded portion 30 integrally provided on the front end surface of the extension fitting 30
& are usually connected by screws. The rod extension fitting 30
The gripper storage box 31 provided on the inner circumferential wall of the rear shield 3 is slidably penetrated so that its rear end faces into the rear shield 3, and the rear end is attached to the rear end by an eccentric metal fitting 32 by an amount of Δδ. A spreader shoe 33 is eccentrically attached to the inner peripheral wall of the rear shield 3 from the center of the rear shield 3 . Each shield jack 2T is connected to a suitable hydraulic pressure supply source (not shown) and pressurized oil is supplied at a constant speed. It is configured to move forward at a constant speed. That is, each shield jack 2T is driven, the shield jack rod 27b extends rearward, and the spreader shoe 33 simultaneously presses the front end surfaces of the segments 21a, 21b, 21a, . . . facing the shield jack rod 27b. Then, each shield jack 2T receives a reaction force, and as a result, the front and rear shields 2 and 3 are moved forward as a unit.

By the way, the lining 21 based on the segment method is effective and effective in constructing tunnels on soft ground as described above, and is the safest, and can prevent collapse of the ground, water springs, etc. However, when excavating free-standing ground using a shoring method, etc., the lining sheet 21 is not installed, and therefore, as shown in FIG. A plurality of first and second gripper jacks 4 each stored and arranged.
0.41 is used. In this case, the gripper storage boxes 28.31 are each formed annularly along the inner circumferential wall of each shield 2.3.

In addition, the first and second gripper jacks are 40°4.
1 are arranged radially inside each gripper storage box 28, 31 at predetermined intervals in the circumferential direction, and each jack 4
0.41 is equipped with grippers 44 and 45 (see FIG. 4) attached to the tips of its jack rods 42 and 43, respectively. These grippers 44, 45 are connected to each shield 2, 3 by normally closing the openings 47° 48 provided on the outer circumferential surface of each gripper storage box 28, 31.
It also serves as the outer peripheral wall of the storage box 28.
31 prevents muddy water from entering each of the shields 2.3. Furthermore, the first and second gripper jacks 40 and 41 are arranged between adjacent shield jacks 27, but the front shield 2 is larger than the rear shield 3. Since the rear shield 3 is heavy, the number of second gripper jacks 41 is increased from that of the first gripper jack 4 in order to form a reaction force that can oppose this when the rear shield 3 moves forward on a self-supporting mountain, which will be described later.
There are many settings including 0 and shi.

Front wall 3 of the gripper storage box 31 of the rear shield 3
1a includes a plurality of plates 50 as shown in FIGS. 3 to 5.
are attached at predetermined intervals, and these plates 50 are provided with connecting portions T to which the aforementioned shield connecting fittings 6 are connected, respectively, and a connecting portion 52 for shield jacks is provided. . These shield jack connecting parts 52 are used when moving the front and rear shields 2 and 3 forward on a self-supporting ground, and are connected to the shield jack rod 27b of each shield jack 21.
are connected to each other. In this case, the rod extension fitting 30 shown in FIG. 6 is removed from the shield jack rod 27b, and replaced with a short connecting fitting 53 shown in FIG.
is threadedly connected to the rod 27b, and this connecting fitting 53 is connected to the shield jack connecting part 5 via a connecting pin 54.
2. Then, the shield connecting fitting 6 that connected the front shield 2 and the rear shield 3 is removed from the connecting portion T as shown in FIGS. 4 and 5. Therefore, both shields 2.3 are connected by the shield jack 2γ, and preparations for alternately moving the shields 2.3 forward are completed.

In such a state, when moving the front and rear shields 2 and 3 forward while the earth is busy excavating, first move the front shield 2 forward at a stroke less than the stroke of the shield jack 27, and then move the shield 2 forward. The rear shield 3 is pulled toward the front shield 2 by the jack 2T, and at this time the first and second gripper jacks 40, 41 are operated alternately. That is, when all the second gripper jacks 41 are driven to extend their jack rods 43, the grippers 45 protrude into the tunnel and bite into the tunnel peripheral wall, thereby fixing the rear shield 3 to the tunnel peripheral wall. Thereafter, when all the shield jacks 2T are simultaneously driven to extend their shield jack rods 27b, the rear shield 3 is pressed through the connecting fittings 53 (see FIG. 7). However, since the rear shield 3 itself is fixed to the tunnel peripheral wall by the second gripper jack 41 and constitutes a reaction force body, the front shield 2 is moved forward by the stroke of the shield jack 2T. In this case, the stroke of the shield jack 2T is set to be shorter than the length 11 (see FIG. 1) of the connecting portion A of both shields 2.3. Further, when the front shield 2 moves forward, the first gripper jack 40 is not operated at all.

Next, after the front shield 2 moves forward and stops, all the first gripper jacks 40 are driven to bite the grippers 44 into the tunnel peripheral wall, and the front shield 2
At the same time, all the second gripper jacks 40 are returned to their original states to release the rear shield 3 from the tunnel peripheral wall. After driving all the shield jacks 27, the shield jack rod 2
7b into the jack body 27a (see FIG. 1), the rear shield 3, which is connected to the rod 27b via the connecting fitting 53, is drawn toward the front shield 2 and moves forward. By repeating these series of operations, the forward movement of the front and rear shields 213, in other words, the folding type shield excavator 1, is guaranteed, making it possible to excavate continuous tunnels in self-supporting ground. do.

As described above, the foldable shield tunneling machine according to the present invention connects the front shield and the rear shield in a bendable and slidable manner, and alternately fixes both shield jacks and each shield to the tunnel peripheral wall. Since the first and second grippers and jacks are configured to move forward alternately, the direction of each shield is easily and reliably controlled, making it possible to construct tunnels with high precision. Because they are moved forward alternately, the thrust of the first and second gripper jacks can be set to a small value, and it is easy to switch to the segment propulsion method. Effective and effective in tunnel construction when used together. In particular, when the first and second gripper jacks are housed in a gripper storage box, each shield is completely watertight, making it easier to switch to the segment propulsion method.

[BRIEF DESCRIPTION OF THE DRAWINGS] Fig. 1 is a longitudinal cross-sectional view showing an embodiment of the folding type shield excavator according to the present invention, Fig. 2 is a half-sectional view taken along line n-■ in Fig. 1,
Figure 3 is an enlarged sectional view of Figure 1 along line m-m, Figures 4 and 5.
The figure is Figure 3 IV-TV line and v-v, li+ cross-sectional view,
Figure 6 is a side sectional view showing the state in which the rod extension fitting is connected to the tip of the shield jack, and Figure 7 is a side sectional view showing the state in which the rod extension fitting is connected to the tip of the shield jack, and the front shield and the rear shield are connected by connecting the connecting fitting to the tip of the shield jack. FIG. 1...Central folding type shield excavator, 2...Front shield, 3...Rear shield, 27...Shield jack, 40...First gripper jack, 41
...Second gripper jack, 44.45...
Gripper, A...Connection part.

Claims (1)

[Claims] A front shield and a rear shield that are bendable and are connected to each other so as to be slidable relative to each other during forward movement; and a shield that is located at a joint between the two shields, with one end held by the front shield and the other end selectively attached to the rear shield. a connected shield jack, and first and second gripper jacks that are respectively disposed within the front shield and the rear shield and operate alternately when these shields move forward to fix each shield to the tunnel peripheral wall. A folding type shield excavator that is characterized by the following: