JPH0782988A - Outbreaking device of shield excavator - Google Patents

Abstract

PURPOSE:To make easily outbreak-excavation even if a bedrock is a hard soil layer or a sand gravel layer mixed with cobbl stone and to make it possible to ensure a sufficient amount of outbreak and durability. CONSTITUTION:A roller bit 13 having a plurality of disk-like blades 13a are provided to a bearing body 15 located around the outermost peripheral surface section of a revolving cutter heard 5 and sliding in the direction of the radius with the expansion of a hydraulic jack 18 in a rotatable manner in a state to incline the axial center against a driving direction. The ends of the blades of the roller bit 13 are projected and recessed from a normal excavation face 24 of the cutter head 5 with the hydraulic jack 18.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shield excavator overexcavation device suitable for excavating a hard soil layer or a cobblestone-containing gravel layer.

[0002]

2. Description of the Related Art A shield excavator uses an overcutting device called an overcutter or a copy cutter in order to facilitate excavation of the ground into a hole diameter larger than the outer diameter of the shield main body when making a curve or correcting the direction of the shield excavator. Equipped.

Conventionally used excavation equipment has a cylindrical shank 26 with a cemented carbide tip 27 radially embedded in its end (FIG. 4), or a tooth bit 28 at the end of the cylindrical shank 26. The bolt-joined one (FIG. 5) was projected radially outward from the outermost peripheral portion of the cutter head 5 by the hydraulic jack 29 to perform overdrilling.

As another example of the excavator, as shown in FIG. 6, a holding body 31 in which a tilted roller bit 30 is rotatably held and a supporting shaft body 32 are provided at appropriate positions in the peripheral portion of the front surface of the cutter head 5. Via the cylinder device 33 so that the holder 31 is swung by the cylinder device 33 so that the outer peripheral portion of the inclined roller bit 30 is positioned outside the shield body and inside the shield body. The one that is moved between the two is also described in Japanese Utility Model Laid-Open No. 61-6598.

[0005]

The overexcavation apparatus shown in FIGS. 4 and 5 is originally intended for excavation of soft ground or gravel ground, and it is often used in deep soil construction, which is increasing in recent years. For the cobblestone-mixed gravel layer, it is difficult to excavate or the tooth bit 28 is broken, which causes the progress speed of the shield machine not to be increased.

On the other hand, the overburdening device shown in FIG. 6 uses a roller bit having a rock crushing function so that it can cope with a hard soil layer or a cobblestone-containing gravel layer. In the structure in which the holding body 31 in which the inclined roller bit 30 is rotatably held is rocked around the support shaft body 32, the roller bit 30 in the cutter head radial direction is formed.
It is difficult to obtain a large amount of blade edge movement, that is, the amount of excess excavation, and the blade edge of the roller bit 30 is in the same row as the normal excavation surface in front of the cutter head and is in contact with the ground even when not excavating. The amount of wear of the cutting edge is large and durability is impaired.

An object of the present invention is to provide a shield excavator capable of easily performing overdrilling and securing a sufficiently large amount of overburden and durability even if the ground is a hard soil layer or a cobblestone gravel layer. To provide a digging device.

[0008]

In order to achieve the above object, the present invention is a support located near the outermost peripheral portion of a rotating cutter head and sliding in the radial direction of the cutter head as the hydraulic jack expands and contracts. A roller bit equipped with a plurality of disc-shaped blades is rotatably attached to the body with the shaft center inclined relative to the excavation direction, and the blade tip of the roller bit is normally excavated by the cutter head when the hydraulic jack is extended. It is characterized in that the blade tip of the roller bit is projected to the position outside the surface and the blade tip of the roller bit is retracted to the position inside the excavation surface of the cutter head when the hydraulic jack is contracted.

[0009]

When a dug is required, the hydraulic jack of the dug device is extended so that the roller bit mounted on the support with the axis inclined with respect to the direction of excavation moves in the radial direction of the cutter head together with the support. The blade tip of the roller bit is moved to a position outside the normally excavated surface of the cutter head to a position outside. By doing this, the roller bit rolls while its protruding blade edge is pressed against the ground by the propulsion force of the shield machine, and exerts the rock crushing function due to the wedge effect of the blade edge. Even if it is a layer or a boulder-mixed gravel layer, it is possible to carry out excess excavation corresponding to the protruding amount of the cutting edge.

Further, when the excavation is not necessary, the cutting edge of the roller bit can be retracted to the position inward of the excavation surface of the cutter head by retracting the hydraulic jack of the excavation device. It will not hit the edge and the wear of the cutting edge can be reduced.

[0011]

Embodiments of the present invention will be described below with reference to FIGS. In the figure, 1 is an earth pressure type shield machine, and a dome-shaped cutter head 5 that forms a cutter chamber 4 between the shield body 2 and a partition wall 3 of the shield body 2 has a rotating bearing 6 at the front portion thereof. The cutter head 5 is rotatably supported via a ring gear 7 provided on the inner ring of the turning bearing 6 and a pinion 8 meshing with the ring gear 7,
It is rotationally driven by a cutter drive motor 9 installed behind the partition wall 3. A plurality of roller bit mounting grooves 10 are provided on the face plate 5a of the cutter head 5, and a slit 11 for taking in sediment is provided between the grooves 10. Of these, one of the groove portions 10 located in the vicinity of the outermost peripheral portion of the cutter head 5 is equipped with the excavation device 12 of the present invention. The excavator 12 includes a plurality of disc-shaped blades 1.
A support (shank) 15 slidably held in the radial direction of the cutter head 5 by a roller bit 13 provided with 3a and a cylindrical guide 14 provided inside the face plate 5a.
And the rod end is incorporated into the support 15 and
It is composed of a hydraulic jack 18 connected to a bracket 16 of a by a pin 17. The roller bit 13 is rotatably attached to the tip end portion of the support body 15 via the bearing base 13b in a state where the shaft center is inclined with respect to the excavation direction so that the blade edge faces the cutting face side, and the hydraulic jack is used. With the expansion and contraction of 18, the cutter head 5 moves together with the support 15 in the radial direction. Reference numeral 19 is a detent pin fixed to the cylindrical guide 14, and the tip of the detent pin engages with the groove 15a of the support 15 to prevent the support 15 from rotating. Further, the hydraulic jack 18 is provided with a rotary joint 20 located behind the partition wall 3 and connected to a hydraulic pressure source, a central pipe 21 of the cutter head 5 provided through the cutter chamber 4, a central pipe 21 and a central pipe 21. Hydraulic oil is supplied through a hydraulic hose (not shown) connected to an oil passage in the cutter head 5.
In the groove portion 10 of the face plate 5a, in addition to the above excavation device 12,
A large number of roller bits 22 used for ordinary excavation are mounted, and a large number of cutter bits 23 are mounted on the peripheral edge of the slit 11 of the face plate 5a. Virtual line 2 in FIGS. 1 and 2
Reference numeral 4 denotes a normal excavation surface of the cutter head 5 formed by the roller bit 22 and the cutter bit 23. In addition,
Reference numeral 25 is a screw conveyor for discharging the excavated earth and sand from the cutter chamber 4 into the rear shield machine.

At the time of normal excavation of the earth pressure type shield machine 1 constructed as described above, as shown by the solid lines in FIG. 1 and FIG. The cutting edge is retracted from the excavation surface 24 of the cutter head 5 to the inner position. In this state, since the blade tip of the roller bit 13 does not directly contact the ground, wear of the blade tip can be reduced.

When over dug is required, the roller jack 1 is extended by extending the hydraulic jack 18 of the over dug device 12.
The cutting edge of No. 3 is in a state of protruding from the normal excavation surface 24 of the cutter head 5 to an outer position, as indicated by an imaginary line 13 'in FIGS. In this state, the blade tip of the roller bit 13 tilted in the excavation direction is pressed against the ground by the propulsive force of the shield excavator, so rocks, boulders, etc. are also crushed by the wedge effect of the blade tip, and the cutter head 5 rotates. The protrusion amount S of the blade edge is prevented while preventing uneven wear of the blade edge due to the rolling of the roller bit 13 (see FIG. 2).
You can excavate as much as. Further, the protrusion amount S of the cutting edge may be controlled according to the rotation amount of the cutter head 5 to be used as a copy cutter for excavating in a desired shape, for example, a crescent shape.

[0014]

According to the present invention, a roller bit supported in a state where its axis is inclined with respect to the excavation direction is cut by a hydraulic jack until the cutting edge protrudes outward from the normal excavation surface of the cutter head. Since it can be moved in the radial direction of the head, even if the ground is a hard soil layer or a boulder-mixed gravel layer, overburden can be easily performed using the rock crushing function of the roller bit, and the progress speed of the shield machine Can be increased.

Further, as compared with the conventional example shown in FIG. 6, the jack stroke can be used as it is as the moving amount of the blade edge of the roller bit in the radial direction of the cutter head. Otherwise, the blade tip of the roller bit can be retracted to a position inward of the normal excavation surface of the cutter head, so that wear of the blade tip is reduced and durability of the overdrilling device can be enhanced.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of a shield machine equipped with an overexcavation device of the present invention.

FIG. 2 is an enlarged view of a main part of FIG.

FIG. 3 is a front view of the cutter head of FIG.

FIG. 4 is a longitudinal sectional view of a main part of Conventional Example 1.

FIG. 5 is a longitudinal sectional view of a main part of Conventional Example 2.

FIG. 6 is a longitudinal sectional view of a main part of Conventional Example 3.

[Explanation of symbols]

2 ... Shield body, 5 ... Cutter head, 12 ... Excavator, 13, 13 '... Excavator roller bit, 13a ... Disc-shaped blade, 14 ... Cylindrical guide, 15 ... Support, 18 ... Hydraulic jack, 24 ... Excavation surface of the cutter head at normal times.

Front page continuation (72) Inventor Takeshi Yoshida 650 Jinrachi-cho, Tsuchiura-shi, Ibaraki Hitachi Construction Machinery Co., Ltd. Tsuchiura Plant (72) Inventor Nobuyoshi Tamachi 2-544 Shimoyama-cho, Furukawa-shi, Ibaraki Furukawa Plant Co., Ltd. (72) Inventor Shigeru Kumakura 2-544 Shimoyama-cho, Furukawa City, Ibaraki Prefecture

Claims (1)

[Claims] 1. A roller bit provided with a plurality of disk-shaped blades on a support located near the outermost peripheral portion of a rotating cutter head and sliding in the radial direction of the cutter head as the hydraulic jack expands and contracts. Is rotatably mounted with its axis inclined with respect to the direction of excavation, the blade tip of the roller bit is projected to a position outside the excavation surface of the cutter head when the hydraulic jack is extended, and the roller is retracted when the hydraulic jack is contracted. An excess excavation device for a shield machine, characterized in that the cutting edge of the bit is configured to be retracted from the excavation surface of the cutter head to a position inward.