JPH0115755Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a bending type shield excavator, in particular, when excavating in a bent state, the pressing force of the shield jack is applied approximately perpendicularly to the contact surface between the segment and the spretshu. The present invention relates to a folding type shield excavator that can prevent these damages and make the radius of curvature of curved construction as small as possible.

Generally, when constructing a curved line using a shield excavator, a construction method is used in which over-digging is performed using an overcut or copy cutter, and the excavating machine is advanced into the area where this over-excavation has been performed. Furthermore, in order to reduce the construction cost and construction period, it is required to reduce the amount of excess excavation. On the other hand, if the amount of excess digging is small, the excavator cannot be bent significantly, and the radius of curvature of curved construction becomes large. Against this background, in order to create a shield excavator that can obtain a small radius of curvature even with a small amount of excess excavation, the shield frame is divided into two at the axial middle part, and the front frame and rear frame are bent. A breakable type shield excavator that can dig is being considered.

By the way, in the case of the conventional folding type shield tunneling machine, as shown in FIG. 1, the shield jack 1 for propulsion has its proximal end 2 rotatably supported on the front frame 3. The jacking thrust is configured to obtain a reaction force on the end face of the segment 4 via the spread dash 5 and to act on the front frame 3. Therefore, the basic movement is that the front frame 3 obtains thrust, and the rear frame 6 moves to the front frame 3 via the bending jack 7 provided across the front frame 3 and the rear frame 6. It will be led by In addition, when proceeding around a curve, the rear frame 6 is left in an idle state so that the direction in which it faces can be freely set according to the radius of curvature of the curved construction. Next, as shown in FIG. 2, the shield jack 1 on the outer periphery side in the direction of the curve is pressed one-sidedly to move the front frame 3 along the curved trajectory. The rear frame 6 follows the bending of the front frame 3 from the idle state, and a center bending angle θ is ensured due to the stroke difference of each shield jack 1. To ensure this state continuously,
Excavate with one side of Shield Jacket 1 pressed.

As explained above, when constructing a curved line using a conventional folding type shield excavator, excavation is carried out with the shield jack 1 pushed in one direction, resulting in the following problems.

The front proximal end of the shield jack is pivotally supported by the front frame, and the rear free end is in contact with the end face of the segment via the spreader, but when the front frame and the rear frame are in a bent state. will swing around the front proximal end. Therefore, a support device for the shield jack is required to absorb the amount of movement caused by the rocking. However, as the bending angle θ increases, the swing angle and the amount of movement also increase, and it is difficult to provide a support device that can absorb this large amount of movement.

When the front frame and rear frame are in a bent state, the posture of the shield jack is inclined with respect to the rear frame, so the spray dash will hit the inner peripheral surface of the rear frame, and if you try to propel it as it is, there is a risk that the shield jack will be damaged. There is.

Further, since the pressing force of the shield jack acting on the end face of the segment is not perpendicular to the end face but is pressed diagonally, there is a risk that the segment may be damaged.

The present invention has been devised in view of the above-mentioned problems and to effectively solve them.

The purpose of the present invention is to apply the pressing force of the shield jack almost perpendicularly to the contact surface between the segment and the spretz dash during curved construction to prevent damage to these parts, and to reduce the radius of curvature of curved construction as much as possible. To provide a foldable type shield excavator that can be made small.

A preferred embodiment of the present invention will be described below with reference to the accompanying drawings.

FIG. 3 shows a schematic configuration of a folding type shield excavator according to the present invention.

The shield frame is the front frame 3 with the same outer diameter.
and a rear frame 6, and the outer diameter of the front end of the rear frame 6 is reduced and the frame is fitted into the rear end of the front frame 3 so as to be internally and superimposed thereon.

At the overlapping portion of the front frame 3 and rear frame 6, shield jacks 1 and bending jacks 7 are alternately arranged at approximately equal intervals along the circumferential direction, as shown in FIG. Further, as shown in FIGS. 5 to 7, the shield jack 1 passes through a rear frame girder 8 provided on the rear frame 6 and is fixed thereto. It passes through the front frame girder 9 in a loosely fitted state, and the front and rear frames 3, 6
It is configured to allow bending. The bending jack 7 has its front end (the cylinder tip in the illustrated example) rotatably supported on the front frame 3 via a bracket 10 by a spherical bearing or the like, and its rear end (the rod tip in the illustrated example). ) is rotatably supported by the rear frame 6 and rear frame girder 8. Further, the bending jacks 7 pass through the front and rear frame girders 8 and 9, but are loosely fitted in both of them and are configured to allow the front and rear frames 3 and 6 to bend. There is.
The bending jack 7 has the same ability as the shield jack 1 (the cylinder inner diameter, rod diameter, and working pressure are the same) in order to transmit the thrust of the shield jack 1 from the rear frame 6 to the front frame 3. .

A sealing member 11 is provided in the gap between the front frame 3 and the rear frame 6 at approximately the middle of the plane where they overlap, allowing them to slide in the front and rear directions while preventing water from entering the overlap area. It is configured to prevent

Next, the operation of the present invention will be explained.

The thrust of the shield jack 1 obtains its reaction force on the end face of the segment 4 via the spread dash 5.
It acts on the rear frame 6 first. The thrust is transmitted from the rear frame 6 to the front frame 3 via the bending jack 7 to push it, and both the front and rear frames 3 and 6 are dug by the thrust of the shield jack 1. In addition, when making a turn, first extend the shield jack 1 and then use the spread jack 5.
The shield jack 1 is fixed by bringing it into contact with the existing segment 4. This prevents the rear frame 6 from moving backward even if the bending jack 7 extends. Next, a reaction force is applied to the rear frame 6, and while a stroke difference (extension difference) is provided to the bending jack 7, digging is performed using only the front frame 3. Excavation is performed using only the front frame 3 until a bending angle θ of the front and rear frames 3, 6 is obtained in accordance with the radius of curvature set for curved construction.
As shown in FIG. 8, the bending jack 7 is fixed in a state where a predetermined bending angle θ is secured, and then, while maintaining the bent state, the individual shield jacks 1 are evenly propelled to advance the excavation. Continue.

In addition, when excavating using only the front frame 3,
If the predetermined bending angle θ cannot be obtained by one stroke extension of the bending jack 7, the bending jack 7 is shortened in synchronization with the extension of the shield jack 1 as a jack for preventing the front frame from retreating; Excavation is performed again using only the front frame 3 to obtain a predetermined bending angle θ.

As is clear from the above explanation, the present invention provides the following excellent effects.

(1) During curved construction, the pressing force of the shield jack can be applied approximately perpendicularly to the contact surface between the segment and the spreader.

(2) Therefore, damage to the spread dash and segments can be prevented.

(3) Since there is no swinging of the shield jack, there is no need for a supporting device for the shield jack to absorb the amount of movement thereof, thus achieving a large center bend angle and making the radius of curvature of curved construction as small as possible. be able to.

(4) Compared to a mechanism in which the rear frame is towed, setting the center bending angle only needs to be adjusted on the front frame, making operability as high as possible.

(5) Since the bending jacks are placed between the shield jacks, the overall length of the shield excavator can be shortened and the ease of working on curves can be improved as much as possible.

(6) Since the bending jack and the shield jack have the same ability, great bending performance can be obtained.

(7) The structure is simple and can be easily adopted.

[Brief explanation of the drawing]

Figure 1 is a schematic configuration diagram showing the conventional folding type shield tunneling machine in a straight traveling state, Figure 2 is a schematic diagram showing the curved traveling state of the shield tunneling machine of Figure 1, and Figure 3 is a diagram showing the structure of the shield tunneling machine according to the present invention. A schematic configuration diagram showing an embodiment of a bending type shield tunneling machine, FIG. 4 is a view taken along the - line in FIG. 3, and FIG. 5 is an implementation of the arrangement of the shield jack and bending jack according to the present invention. FIG. 6 is a side sectional view showing an example of how the shield jack is attached according to the present invention; FIG. 7 is an example of how the bending jack is attached according to the present invention. FIG. 8 is a side cross-sectional view showing an example, and is a schematic configuration diagram showing a bending state of the folding type shield tunneling machine according to the present invention. In the figure, 1 is a shield jack, 3 is a front frame, 6 is a rear frame, and 7 is a bending jack.

Claims (1)

[Scope of utility model registration request] In a center-folding type shield excavator in which a cylindrical shield frame is divided into a front frame and a rear frame at its axially intermediate portion, and these front and rear frames are connected to each other in a flexible manner, Shield jacks for propulsion are provided on the inner peripheral surface of the rear frame at approximately equal intervals along the circumferential direction, and one end is provided between the shield jacks, and one end is located on the inner peripheral surface of the front frame. 1. A bending type shield excavator, comprising: a bending jack, the other end of which is pivotally supported on the inner circumferential surface of the rear frame;