JPH0419112Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a small-diameter shield excavator having a gravel crushing mechanism.

(Prior Art) Conventionally, as a shield excavator for propelling and excavating a small-diameter tunnel while crushing gravel, a device as described in, for example, Japanese Patent Application Laid-Open No. 60-215996 has been known.

This device has a conical rotary head that becomes larger in diameter toward the rear inside the front end opening of the shield body, and while eccentrically rotating the rotary head, the inner peripheral surface of the opening of the shield body and the conical shape of the rotary head are rotated eccentrically. It is configured to crush gravel by feeding it so that it bites between the outer peripheral surfaces.

(Problem to be solved by the invention) However, since the rotary head rotates in a fixed position, even if the rotary head is eccentric, the opening width between its outer circumferential surface and the inner circumferential surface of the opening of the shield body hardly changes. Therefore, when excavating the ground such as a clay layer, the shield is press-fitted and adhered in a compacted state between the inner surface of the shield body, whose opening width becomes narrower toward the rear, and the conical outer surface of the rotary head. Excavation and discharge of earth and sand becomes difficult.

Further, during excavation, large soil pressure is applied from the ground side over the entire length of the outer peripheral surface of the shield body, so there is a problem that the excavation direction of the shield body cannot be smoothly controlled.

The object of the present invention is to provide a shield excavator that solves these problems.

(Means for Solving the Problems) In order to achieve the above object, the shield excavator of the present invention has the following features as shown in the drawings corresponding to the embodiments:
The rear part of a cutter head 3 which is rotated by a drive device 11 is rotatably supported on the partition wall 2 in the shield shell 1, and the diameter of the front part of the cutter head 3 gradually becomes smaller toward the rear, and its center is offset from the center of rotation. A truncated cone-shaped earth and sand intake port 4 is formed in the center so that the earth and sand intake port 4 faces the front end opening of the shield shell 1, and a hole is formed on the front end outer circumferential surface of the cutter head 3 outward from the front end surface outer circumference of the shield shell 1. A protruding cutter blade 5 is attached, and a shaft portion 9 of a center cutter 9 is attached to the rear center of the cutter head 3 and is slidable back and forth on the central axis of the shield shell 1.
b is inserted, the front end cone portion 9a of the center cutter 9 is disposed in the space inside the earth and sand intake port 4 of the cutter head 3, and the earth and sand discharge port 7 is provided at the rear end of the earth and sand intake port 4. 6 are arranged in series, and a longitudinally movable jack 18 for the center cutter 9 is disposed inside the rear part of the partition wall 2.

(Function) When excavating gravel ground by moving the shield shell 1 forward while rotating the cutter head 3, the gravel in the earth and sand taken into the earth and sand intake port 4 of the cutter head 3 is transferred to the truncated cone of the earth and sand intake port 4 which rotates eccentrically. Between the shape surface 4a and the cone portion 9a of the center cutter 9
While passing through the gap, it is crushed into small pieces and discharged together with the earth and sand from the earth and sand discharge port 7 at the rear.

When large-diameter gravel is taken into the cutter head 3 during excavation, when the center cutter 9 is moved forward, the outer peripheral surface of the cone portion of the center cutter 9 and the truncated conical surface 4a of the earth and sand intake port 4 As the gap between the holes becomes larger, large-diameter gravel can easily enter the center cutter 9. Furthermore, by moving the center cutter 9 back and forth, it becomes possible to draw in the gravel, and the cutter head 3
Since the center of the truncated cone-shaped earth and sand intake port 4 is eccentric with respect to the rotation center, the rotation causes a ring between the inner peripheral surface of the earth and sand intake port 4 and the outer peripheral surface of the cone portion of the center cutter 9. The width of the shaped opening changes continuously, and even when excavating a clay layer, it eliminates clogging and allows for smooth uptake.

Further, since the cutter blade 5 attached to the outer circumferential surface of the front end of the cutter head 3 protrudes outward from the outer circumference of the front end surface of the shield shell 1, it is possible to excavate a hole with a larger diameter than the outer diameter of the shield shell 1. shield shell 1
The direction can be easily corrected.

(Example) To explain the example of the present invention with reference to the drawings, 1
is a cylindrical shield shell, with a front cylinder part 1a and a middle cylinder part 1.
b. The rear cylindrical portion 1c is integrally connected, and the adjacent cylindrical portions inside are partitioned by partition walls 2a and 2b, respectively, and a cutter head 3 is provided in the center of the front partition 2a.
The shaft portion 3a is rotatably inserted and supported.

The front part of the cutter head 3 is formed to have a large diameter, and the inner circumferential surface of the large diameter part 3b is formed into a truncated cone-shaped earth and sand intake port 4 whose diameter gradually becomes smaller toward the rear from the front end opening. Along with this sediment intake port 4
The front end of the shield shell 1 is made to project forward from the front end of the shield shell 1, and the outer periphery is formed to be approximately equal to the outer diameter of the shield shell 1. cutter blades 5 are attached.

Reference numeral 6 denotes a recess bored in the shaft portion 3a of the cutter head 3, and its front end opening is connected to the rear end of the hard facing truncated conical surface 4a of the earth and sand intake port 4. The center of the earth and sand intake port 4 formed in the recess 6 and the truncated conical surface 4a is eccentric with respect to the central axis of rotation of the cutter head 3.

Reference numeral 7 denotes a discharge port extending from the recess 6 to the outer circumferential surface of the shaft portion 3a, and is connected to the shield shell 1 in the front part of the partition wall 2.
and the space 8 between the shaft portion 3a.

Reference numeral 14 denotes a stirring blade protruding toward the space 8 from the outer peripheral surface of the shaft portion 3a.

Reference numeral 9 designates a center cutter having a hollow shaft portion 9b inserted into the center of the shaft portion 3a of the cutter head 3 so as to be slidable in the front and back direction, and the hollow shaft portion 9b is formed to have a smaller diameter than the recess 6. At the same time, the front end is formed into a large-diameter cone portion 9a, and the outer peripheral surface of the cone portion 9a is a truncated conical surface inclined in the opposite direction to the truncated conical surface 4a of the earth and sand intake port 4 of the cutter head 3. A plurality of blades 10, 10, each having an outer end surface substantially parallel to the truncated conical surface of the earth and sand intake port 4, are protruded radially from the circumferential surface thereof.

Reference numeral 11 denotes a cutter head drive device whose front end is fixed to three sides of the rear partition wall 2b of the partition wall 2, and a small gear 12 fixed to its rotating shaft meshes with a large diameter gear 13 formed on the outer peripheral surface of the shaft portion 3a of the cutter head 3. The cutter head 3 is rotated by rotating the cutter head 3.

Reference numeral 15 denotes a cylindrical bearing fixed to the center of the rear partition wall 2b, into which the rear end of the shaft 9b of the center cutter 9 is slidably inserted.
Reinforcing members 16 are radially fixed to the rear surface of the rear partition wall 2b on three sides of the outer periphery of the rear partition wall 2b.

Reference numeral 17 denotes a jack fixing member fixed to the rear end of the bearing 15, to which a longitudinally movable jack 18 connected to the rear end of the hollow shaft portion 9b of the center cutter 9 is fixed.
A joint 20 of a water pipe 19 communicating with the hollow shaft portion 9b is connected to the rear end of the jack 18.

Reference numeral 21 designates an ejection hole bored in the front end of the hollow shaft portion 9b of the center cutter 9, and is open toward the recess 6.

Reference numeral 22 denotes a short sludge draining pipe arranged between the outer peripheries of the front and rear partition walls 2a and 2b at appropriate locations, with its front end opening facing the space 8 and its rear end facing toward the mine entrance. It is connected to pipe 23.

24 is a radial thrust bearing ring that rotatably supports the cutter head 3.

Reference numeral 25 denotes a plurality of direction adjustment jacks whose rod tips are connected to the rear outer ends of the respective reinforcing members 16, and whose rear ends are connected to the front end of a short pipe 26 connected to the rear end of the rear cylinder portion 1c of the shield shell 1. It is supported by the department.

27 is a tube body such as a trailing tube or a temporary tube connected to the short tube 26.

To describe the operation of the shield excavator of the embodiment configured as described above, the pipe body 27 following the shield shell 1 is pressed from the mine entrance side to push the shield shell 1 into the ground, and the cutter head drive device 11 is driven. The cutter head 3 is driven to rotate, and the hollow shaft portion 9b of the center cutter 9 is further connected to the water pipe 19.
Mud water is spouted from the spout hole 21 into the space 8 through the spout.

The earth and sand excavated by the rotation of the cutter head 3 and the earth and sand taken into the intake port 4 by the advancement of the shield shell 1 are transferred to the truncated conical surface of the intake port 4.
a and the cone portion 9a of the center cutter 9 into the recess 6. In addition, the gravel in the earth and sand is crushed by the truncated conical surface 4a of the earth and sand intake port 4 which is rotating eccentrically and the outer peripheral surface of the cone portion 9a of the center cutter 9, but at this time, the center cutter 9
The outer circumferential surface of the cutter head 3 is formed into a truncated conical surface facing opposite to the truncated conical surface 4a of the earth and sand intake port 4, and a plurality of fixed vanes 10 are protruded from the outer circumferential surface, so that rotation of the cutter head 3 is prevented. Despite this, the gravel that comes into contact with the fixed blade 10 and is caught is easily and quickly crushed, while large-diameter gravel can be crushed by moving the center cutter 9 forward by the operation of the forward and backward movement jack 18. Crushing can be achieved by increasing the distance between the outer peripheral surface of the cone portion of the center cutter 9 and the truncated conical surface 4a of the earth and sand intake port 4. Furthermore, during excavation, the center cutter 9 is reciprocated back and forth to draw in gravel, and if the excavated ground is a clay layer, the truncated conical surface 4a of the earth and sand intake port 4 and the center cutter 9 are This is to prevent clogging by varying the distance between the outer peripheral surfaces of the cone portions 9a.

The earth and sand thus introduced into the recess 6 passes through the hollow shaft portion 9b of the center cutter 9 and passes through the spout hole 2.
From the discharge port 7 to the space 8 along with the muddy water spouted from 1
The sludge flows into the sludge drain pipe 22 and is discharged outside the mine through the sludge pipe 23.

When the direction of the shield shell 1 is to be corrected during excavation, a predetermined jack 25 is operated to change the direction of the shield shell 1. At this time, the cutter blade 5 attached to the front end of the cutter head 3 protrudes outward from the outer periphery of the front end surface of the shield shell 1, and since a hole having a diameter larger than the outer diameter of the shield shell 1 is drilled, the direction can be easily corrected.

(Effects of the invention) As described above, according to the shield excavator of the present invention, the earth and sand intake port 4 of the cutter head 3 is shaped like a truncated cone, which has a small diameter as it faces backward, and whose center is eccentric with respect to the center of rotation. At the same time, the front end cone portion 9a of the center cutter 9 is arranged so as to be movable back and forth within the earth and sand intake port 4.
As the cutter head 3 rotates, the truncated cone-shaped earth and sand intake port 4 rotates eccentrically, and the ring-shaped opening width between its inner circumferential surface and the outer circumferential surface of the cone portion 9a of the center cutter 9 changes in the direction of expanding and contracting. Even when the center cutter 3 and the center cutter 9 are rotating at a fixed position, the gravel can be reliably crushed by the opposing surfaces that expand and contract.Also, large diameter gravel can be moved forward by the center cutter 9 by the operation of the forward and backward movement jack 18. By doing so, the distance between the outer circumferential surface of the cone portion of the center cutter 9 and the truncated conical surface 4a of the earth and sand intake port 4 is increased, and the material can be taken between the two surfaces for reliable crushing. .

Furthermore, during excavation, the center cutter 9
By reciprocating back and forth, gravel can be smoothly drawn into the earth and sand intake port 4, and the face can be held down to prevent collapse of the face ground. Furthermore, if the excavated ground is a clay layer, the gravel can be drawn into the earth and sand intake port 4 smoothly. Since the ring-shaped gap between the truncated conical surface 4a of the intake port 4 and the outer peripheral surface of the cone portion 9a of the center cutter 9 changes continuously, clogging can be prevented.

Further, since the cutter blade 5 that protrudes outward from the outer circumference of the front end surface of the shield shell 1 is attached to the outer circumferential surface of the front end of the cutter head 3, a hole having a diameter larger than the outer diameter of the shield shell 1 can be excavated. , the direction of the shield shell 1 can be easily adjusted and controlled during excavation.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, in which Fig. 1 is a vertical side view, Fig. 2 is a front view, and Fig. 3 is a side view of the first embodiment.
- It is a sectional view taken along the A line. DESCRIPTION OF SYMBOLS 1... Shield shell, 2... Partition wall, 3... Cutter head, 4... Sediment intake port, 4a... truncated conical surface, 5... Cutter blade, 6... Recess, 7...
Discharge port, 8... Space part, 9... Center cutter, 9a... Cone part, 9b... Hollow shaft part, 10
...Blade, 11...Cutter head drive device, 1
8... Back and forth movement jack, 19... Water pipe, 21...
...Blowout hole, 23...Sludge drainage pipe, 25...Direction correction jack.

Claims (1)

[Claims for Utility Model Registration] A rear part of a cutter head 3 rotated by a drive device 11 is rotatably supported on a partition wall 2 in a shield shell 1, and the front part of the cutter head 3 has a diameter that gradually becomes smaller toward the rear. A truncated cone-shaped earth and sand intake port 4 whose center is eccentric with respect to the rotation center is formed, and the earth and sand intake port 4 faces the front end opening of the shield shell 1 and is shielded on the front end outer peripheral surface of the cutter head 3. A cutter blade 5 protruding outward from the outer periphery of the front end face of the shell 1 is attached to the center of the rear of the cutter head 3, and is slidable back and forth on the central axis of the shield shell 1, and whose rotation center is aligned with the rotation of the cutter head 3. The shaft portion 9b of the center cutter 9 aligned with the center is inserted, and the front end cone portion 9a of the center cutter 9 is disposed in the space inside the earth and sand intake port 4 of the cutter head 3, and the earth and sand intake port 4, a recess 6 having an earth and sand discharge port 7 is successively provided at the rear end of the shield excavator 4, and a back-and-forth movable jack 18 of a center cutter 9 is disposed in the rear part of the partition wall 2. The shield excavator according to claim 1, which is a registered utility model, in which a plurality of blades 10, 10 are provided radially projecting from the outer peripheral surface of the cone portion 9a of the center cutter 9.