JP4247473B2 - Shield excavator - Google Patents

Description

  The present invention relates to a shield excavator, and more particularly to a shield excavator for excavating a tunnel having a non-circular cross-sectional shape.

Conventionally, the cross-sectional shape of a shield tunnel has been circular, but it has been desired to develop a shield excavator that can excavate a tunnel having a free cross-sectional shape depending on the application. Therefore, in recent years, shield excavators capable of excavating a non-circular cross section such as a rectangle or an ellipse have been developed. ), Or an excavator (see Patent Document 2) in which a telescopic cutter is added to a fixed cutter.
(See Patent Document 1).
JP 2000-64782 A (page 2-3, FIG. 3) Japanese Patent Laid-Open No. 6-212883 (Page 2, Fig. 1)

However, an excavator in which circular cutters are arranged in a multiple manner has a risk of being left behind or overexcavated despite the use of a large number of cutters. Further, in the case of an eccentric multi-axis excavator, there are problems that the excavation mechanism is complicated and the shield body swings due to the reaction force of the cutter. Furthermore, in the case of an excavator in which a telescopic cutter is added to a fixed cutter, there is a problem that the telescopic mechanism becomes complicated.
The present invention has been made in view of the above-described problems, and an object thereof is to provide a shield excavator that can smoothly excavate an arbitrary cross-sectional shape and has a simple excavation mechanism.

In order to achieve the above object, in the shield excavator according to the present invention, the outer shell formed in a substantially similar shape to the cross-sectional shape of the tunnel, and the tip portion engaged with the outer shell are movable along the outer shell. The base end portion is rotatably supported around the central axis of the shield body, the intermediate portion includes a cutter that is extendable and contractible in the radial direction of the shield body, and the rack gear along the inner peripheral portion of the outer shell. And a pinion gear that moves in mesh with the rack gear is mounted on the outer peripheral surface of the motor, and the motor is connected to the tip of the cutter .
In the present invention, a jack or the like for extending or retracting the cutter is required by rotating and driving a retractable cutter around the central axis of the shield body along the outer shell formed in a substantially similar shape to the tunnel cross section. In addition, it is possible to realize a shield excavator that can smoothly excavate an arbitrary cross-sectional shape and has a simple excavation mechanism.

Particularly in the shield excavator according to the present invention, as a driving mechanism for the cutter, a rack gear is provided along the inner peripheral portion of the outer shell, and a pinion gear that meshes with the rack gear and moves on the outer peripheral surface of the motor. Since the motor is connected to the front end of the cutter, the pinion gear is moved on the rack gear by driving the motor, and the cutter is moved along the outer shell together with the pinion gear. Can be rotated around the central axis of the shield body.

  According to the present invention, a jack or the like for expanding and contracting the cutter is driven by rotating the retractable cutter around the central axis of the shield body along the outer shell formed in a substantially similar shape to the tunnel cross-sectional shape. A shield excavator that can smoothly excavate an arbitrary cross-sectional shape and has a simple excavation mechanism can be realized.

Hereinafter, an embodiment of a shield excavator according to the present invention will be described with reference to the drawings.
FIG. 1 is an elevation view showing a first embodiment of a shield excavator. FIG. 2 is a side sectional view thereof. Hereinafter, the digging direction of the shield excavator 1 is referred to as “front” and the opposite side is referred to as “rear”.
The shield excavator 1 according to this embodiment includes four cutters 2 radially extending in a direction orthogonal to the rotation axis 6 around the rotation axis 6 positioned on the central axis in front of the shield body 8 at the front end of the shield body 8. ing. A base end portion of each cutter 2 is pivotally supported on the rotary shaft 6 via a base end shaft 6a.
The shield body 8 includes a skin plate 8b forming an outer shell and a partition wall 8a in front of the shield body 8 that supports the rotating shaft 6. The cross-sectional shape of the skin plate 8b is an elliptical shape that is substantially similar to the tunnel cross-sectional shape.
The cutter 2 includes a rectangular parallelepiped cutter tip portion 3 having a plurality of cutter bits 5 on the front surface and a rectangular parallelepiped cutter extension / contraction portion 4 having a plurality of cutter bits 5 on the front surface.
A front end shaft 3 a is connected to the rear surface of the cutter front end portion 3 in parallel with the rotation shaft 6. A motor 7 for rotating the cutter 2 around the rotation shaft 6 is connected to the other end of the tip shaft 3a, and a pinion gear 7a is mounted on the outer peripheral surface of the motor 7. On the other hand, a rack gear 7b is attached to the inner peripheral surface in front of the skin plate 8b over the entire circumference. The motor 7 is sandwiched between the rack gear 7b on the inner peripheral surface of the skin plate 8b and the skin plate 8c formed on the inner side at a certain distance from the skin plate 8b. The motor 7 moves on the rack gear 7b by rotating the outer peripheral surface of the motor 7 together with the pinion gear 7a.
The cutter expansion / contraction part 4 includes a first member 4a on the distal end side, a second member 4b on the proximal end side, and an intermediate member 4c that connects the first member 4a and the second member 4b. Both ends of the intermediate member 4c are built in the first member 4a and the second member 4b, respectively, and the intermediate member 4c slides in the first member 4a and the second member 4b, so that the cutter expansion / contraction part 4 is shielded. The main body 8 expands and contracts in the radial direction.

Next, the operation of the shield excavator 1 according to this embodiment will be described.
When the motor 7 is driven, the shaft of the motor 7 does not rotate, the outer peripheral surface of the motor 7 rotates with the pinion gear 7a, and the motor 7 moves on the rack gear 7b along the inner peripheral surface of the skin plate 8b. At the same time, the cutter 2 whose tip is connected to the motor 7 also moves along the inner peripheral surface of the skin plate 8b while expanding and contracting the cutter expansion / contraction part 4, and using a plurality of cutter bits 5, a face surface (not shown) Drilling.
In the present embodiment, since the motor 7 is provided for each cutter 2, the rotational angular velocity of the cutter 2 is different for each cutter 2. Therefore, the base end portion of the cutter 2 is pivotally supported on the rotating shaft 6 via the base end shaft 6a.

  In the shield excavator 1 according to the present embodiment, the cutter 2 is driven to rotate about the rotation axis 6 of the shield body 8 along the outer shell 8b formed in a substantially similar shape to the tunnel cross section. A shield excavator 1 that can smoothly excavate an arbitrary cross-sectional shape and has a simple excavation mechanism can be realized without requiring a jack or the like for expanding and contracting 2.

As mentioned above, although the embodiment of the shield excavator according to the present invention has been described, the present invention is not limited to the above-described embodiment, and can be appropriately changed without departing from the gist thereof .

1 is an elevation view showing a first embodiment of a shield excavator according to the present invention. 1 is a side sectional view showing a first embodiment of a shield excavator according to the present invention.

Explanation of symbols

  1 Shield excavator
  2 Cutter
  3 Cutter tip
  4 Cutter telescopic part
  5 Cutter bit
  6 Rotating shaft (center axis of shield excavator)
  7 Motor
  7a Pinion gear
  7b Rack gear
  8 Shield body
  8b Skin plate (outer shell)

Claims (1)

An outer shell that is substantially similar to the tunnel cross-sectional shape;
A distal end portion that engages with the outer shell is movable along the outer shell, a proximal end portion is rotatably supported around the central axis of the shield body, and an intermediate portion expands and contracts in the radial direction of the shield body. With a flexible cutter ,
A rack gear is provided along the inner peripheral portion of the outer shell, and a pinion gear that moves in mesh with the rack gear is mounted on the outer peripheral surface of the motor, and the motor is connected to the tip of the cutter. And shield excavator.

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