JP4286993B2 - Shield excavator - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a shield excavator that is used in a shield construction method, has a simple structure, and can easily and quickly replace a cutter bit in the ground.
[0002]
[Prior art]
The shield method, which is one of the methods for constructing tunnels and tunnels, uses a shield excavator that abuts the face of the tunnel or the like to dig a hole, and then covers the inner wall of the hole with a segment ring to construct the tunnel. It is a construction method and has the feature that it can work safely and reliably.
[0003]
The shield excavator is an excavator that excavates a natural ground using a cutter bit by pushing a head having a cutter bit on the front surface while rotating the head using a driving mechanism such as a hydraulic motor.
In recent years, the shield construction has been extended in terms of construction environment, economy, and shortening of the construction period, and along with this, the durability of each part of the shield excavator has been improved.
[0004]
[Problems to be solved by the invention]
Among shield excavators, the cutter bit is particularly severely deteriorated, and because of its function of excavating directly in contact with natural ground, it is highly worn and must be replaced during construction.
Conventionally, as shown schematically in FIG. 6, a person enters the gap between the face 210 and the shield excavator 100 after the ground 200 around the face is made independent by ground improvement, or the cutter bit is changed. As shown in FIG. 7, after the intermediate shaft 110 was constructed and excavated to the intermediate shaft 110, the cutter bit was exchanged in the intermediate shaft 110.
However, in recent years, in order to make effective use of underground space in urban areas, shield work has become deeper and needs to be constructed with a large cross section. Under such construction conditions, when the cutter bit is replaced by the above-described conventional method, many costs and a long construction period are required.
[0005]
In addition to the conventional method, in JP-A-7-324593, a replacement cutter bit is installed in the cutter head, and the cutter bit is replaced by extruding the replacement cutter bit with an extrusion device such as a jack. Although a shield excavator has also been presented, this shield excavator has a structure in which an extrusion device is installed for each replacement cutter bit, and thus there is a problem that the structure becomes complicated.
[0006]
In view of the above circumstances, an object of the present invention is to provide a shield machine that has a simple structure and can easily and quickly change a cutter bit in the ground.
[0007]
[Means for Solving the Problems]
In order to solve the above-mentioned problem, the invention according to claim 1 is directed to a shield cutter excavator (1) that advances excavation in the ground using a cutter bit provided on the front surface of the cutter head (2). Is held on the front surface (for example, the upper surface 12a), and the movable spoke (12) embedded in the front surface of the cutter head so as to be extrudable, and the movable spoke is pushed out so that the spare cutter bit comes into contact with the face. Means (for example, the spacer 13 and the hydraulic actuator 14). The pushing means is provided on the back side of the movable spoke so as to be movable in a direction parallel to the back surface, and the upper surface (slope 13a) is a slope. Spacer (13), and a moving means (for example, moving the spacer in the direction of pushing into the back surface of the movable spoke) Hydraulic actuator 14), and the movable means pushes out the movable spoke by moving the spacer after the side surface of the spacer is brought into contact with the side portion or the back surface of the movable spoke. Features.
[0008]
According to the first aspect of the present invention, when the excavation efficiency of the cutter bit in use is reduced due to wear, the movable spoke is pushed out using the pushing means to bring the spare cutter bit into contact with the face. The ground can be excavated with a spare cutter bit. That is, the cutter bit can be replaced with a spare part simply by operating the pushing means.
Therefore, since the cutter bit can be exchanged in the ground during construction without modifying the ground such as intermediate shafts and ground improvement, the cutter bit can be exchanged much more easily and inexpensively.
[0009]
Further, since the spare cutter bit is pushed out through the movable spoke, the number of pushing means is reduced. Therefore, since the mechanism for exchanging the cutter bit is simplified, the shield excavator is provided with a more practical spare cutter bit which is inexpensive and has high reliability.
[0011]
According to the first aspect of the present invention, since the driving direction of the moving means such as the hydraulic actuator is different from the moving direction of the movable spoke, the reaction force applied to the moving means even when excavating using the spare cutter bit, The load is reduced. In particular, when the driving direction of the moving means and the moving direction of the movable spoke are perpendicular, this load is almost zero. Therefore, the trouble of the shield excavator due to the moving means is reduced.
[0012]
According to the first aspect of the present invention, as described in the second aspect, the spacer (13) has a substantially trapezoidal shape, and after the movable spoke is pushed out, the upper surface (13b) abuts against the back surface of the movable spoke. Thus, when excavating using the spare cutter bit, it may be configured to be a supporting means that supports the movable spoke so as not to be buried. In this case, the reaction force applied to the spare cutter bit from the face during excavation is received by the spacer. Therefore, since the preliminary cutter bit is stably held, it is not necessary to separately provide a fixing means for fixing and supporting the preliminary cutter bit, and the structure of the peripheral device of the preliminary cutter bit is simplified and its reliability is improved.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the shield excavator 1 which is one Example of this invention is demonstrated in detail using figures.
1A and 1B are a front schematic view and a side schematic view of the shield excavator 1, respectively. 2 is a schematic cross-sectional view in the width direction of the cutter spoke 10 of the shield excavator 1, and FIG. 3 is a schematic cross-sectional view in the longitudinal direction. 4 is a schematic cross-sectional view in the width direction of the cutter spoke 10 when the preliminary cutter bit 16 is extruded, and FIG. 5 is a schematic cross-sectional view in the longitudinal direction.
[0014]
The shield excavator 1 has a configuration in which a total of four cutter spokes 10 having cutter bits are provided at intervals of 90 ° in the circumferential direction on the front surface of the cutter head 2 that abuts against the face, and the cutter head 2 is rotated. This is a shield excavator that excavates the face. That is, since the shield excavator 1 has substantially the same configuration as the known excavator except for the configuration of the cutter spoke 10, only the configuration and functions of the cutter spoke 10 will be described in detail below.
[0015]
2 and 3, the cutter spoke 10 has a substantially rectangular parallelepiped fixed spoke 11 having a hollow portion 11a and a substantially rectangular parallelepiped movable spoke 12 embedded in the hollow portion 11a so as to be movable in the vertical direction. A spacer 13 having a substantially trapezoidal cross section provided in the vicinity of the lower surface side of the movable spoke 12 in a horizontal direction, and a hydraulic actuator 14 that moves the spacer 13 in the horizontal direction and pushes it under the movable spoke 12. And a known hydraulic mechanism 14 a for driving the hydraulic actuator 14.
[0016]
Here, the fixed spoke 11 is provided with the fixed cutter bits 15 projecting from both ends of the long side of the upper surface 11b, which is the surface facing the face, and the movable spoke 12 is the length of the upper surface 12a. Preliminary cutter bits 16 are provided at both end portions on the side in a state of protruding from the upper surface 12a.
The movable spoke 12 is held in a state where the spare cutter bits 16 are settled in the hollow portion 11a.
[0017]
Moreover, the opening part 11c ... which leads to the hollow part 11a is provided in the upper surface 11b so that it may be located just above the preliminary | backup cutter bits 16 ....
The hollow portion 11 a is filled with the grease 18 after the movable spoke 12 is embedded, and the opening portion 11 c is closed with a lid 19 in order to prevent dirt and the like from entering.
[0018]
Further, the lower surface 12b of the movable spoke 12 is supported by the spacer 17 on the bottom surface 11d of the hollow portion 11a with a slight gap. Furthermore, a recess 12c is provided on the lower surface 12b. The side surface of the recess 12c is provided with an inclined surface 12d that rises toward the end side, and the inclined surface 13a of the spacer 13 is held in contact with the inclined surface 12d.
[0019]
Next, the function of the shield excavator 1 will be described.
The shield excavator 1 excavates natural ground by the same method as the conventional shield excavator. At this time, it is the fixed cutter bits 15 that abut the face and cut the ground. If excavation is performed to some extent, the excavation efficiency of the shield excavator 1 decreases due to wear of the fixed cutter bits 15..., So that the spare cutter bits 16 are projected from the opening 11 c by the following method, and the spare cutter bits 16. Use this to advance excavation of natural ground.
[0020]
That is, the hydraulic actuator 14 is driven to push the spacer 13 into the gap on the bottom surface 11 d generated by the spacer 17.
Here, since the inclined surface 13a pushes the inclined surface 12d, the hydraulic actuator 14 applies a lifting force to the movable spoke 12 via the inclined surface 13a of the spacer 13 and the inclined surface 12d of the movable spoke 12.
As a result, the movable spoke 12 is pushed up by the hydraulic actuator 14, and at the same time, the spare cutter bit 16 protrudes outward so as to push out the lid 19 from the opening 11c, and from the fixed cutter bit 15 as shown in FIGS. Is also located on the upper side, that is, the face side.
[0021]
Further, the spacer 13 completely enters the lower surface 12b after the movable spoke 12 is pushed out. Here, since the upper surface 13b of the spacer 13 contacts the lower surface 12b, the spacer 13 supports the movable spoke 12 from below as shown in FIG.
Therefore, once the movable spoke 12 is pushed up, it is stabilized in a state in which the spare cutter bits 16... Are protruded from the fixed cutter bits 15.
As a result, the cutter bits excavating the natural ground are replaced from the fixed cutter bits 15 to the spare cutter bits 16.
[0022]
As described above, according to the shield excavator 1 which is an embodiment of the present invention, the cutter spoke 10 provided in the cutter head 2 is provided with the spare cutter bit 16 in the fixed spoke 11 provided with the fixed cutter bit 15. As a structure in which the movable spoke 12 is buried, the cutter bit for excavating the natural ground is moved from the fixed cutter bit 15 by pushing up the movable spoke 12 and projecting the spare cutter bit 16 to the face of the fixed cutter bit 15. The spare cutter bits 16 can be replaced.
That is, since the cutter bit can be replaced mechanically without performing an auxiliary method such as improving the ground around the intermediate shaft or the face, the cost and time required for replacing the cutter bit are significantly reduced.
[0023]
Further, since a plurality of preliminary cutter bits 16 are provided on the movable spoke 12 and the preliminary cutter bits 16 are projected by pushing up the movable spoke 12, the hydraulic actuator 14 as a power source can be remarkably reduced.
Therefore, the drive mechanism necessary for pushing up the preliminary cutter bits 16 is simplified, the cost for the mechanism is reduced, and the equipment trouble is reduced and the reliability is improved.
[0024]
Further, as a mechanism for pushing up the movable spoke 12, a spacer 13 having a substantially trapezoidal cross section is provided on the lower surface side portion of the movable spoke 12, and the spacer 13 is pushed under the movable spoke 12 using the hydraulic actuator 14. 13 pushes up the movable spoke 12 and supports the movable spoke 12 from below.
Therefore, the movable spoke 12 and the spare cutter bits 16 are stably held during excavation without providing a special fixing mechanism. Further, since the hydraulic actuator 14 is not loaded when excavating a natural ground using the spare cutter bits 16..., The equipment trouble is further reduced.
[0025]
In addition, this invention is not limited to a present Example, In the range which does not deviate from the meaning, it can change arbitrarily.
[0026]
【The invention's effect】
According to the first aspect of the present invention, the movable spoke is pushed out using the pushing means to bring the spare cutter bit into contact with the face, that is, the cutter bit is replaced with a spare part only by operating the pushing means. Therefore, it is possible to replace the cutter bit without modifying the ground such as intermediate shafts and ground improvement, so the cutter bit can be replaced much more easily and inexpensively.
Further, since the spare cutter bit is pushed out through the movable spoke, the number of pushing means is reduced. Therefore, since the mechanism for exchanging the cutter bit is simplified, the shield excavator is provided with a more practical spare cutter bit which is inexpensive and has high reliability.
[0027]
According to the first aspect of the present invention, since the driving direction of the moving means such as the hydraulic actuator is different from the moving direction of the movable spoke, the load applied to the moving means is small even when excavating using the spare cutter bit. Therefore, the trouble of the shield excavator due to the moving means is reduced.
[0028]
According to the second aspect of the present invention, since the reaction force applied to the spare cutter bit from the face during excavation is received by the spacer, there is no need to separately provide fixing means for fixing and supporting the spare cutter bit. The structure of the peripheral device is simplified and the reliability thereof is improved.
[Brief description of the drawings]
FIGS. 1A and 1B are a schematic front view and a schematic side view of a shield excavator according to an embodiment of the present invention, respectively.
FIG. 2 is a schematic cross-sectional view in the width direction of a cutter spoke of the shield excavator.
FIG. 3 is a schematic cross-sectional view in the longitudinal direction of the cutter spoke.
FIG. 4 is a schematic cross-sectional view in the width direction of a cutter spoke when a preliminary cutter bit is pushed out.
FIG. 5 is a schematic longitudinal sectional view of the preliminary cutter bit.
FIG. 6 is a diagram for explaining a conventional method for replacing a cutter bit of a shield machine.
FIG. 7 is a diagram for explaining another conventional method for exchanging the cutter bit.
[Explanation of symbols]
1 Shield machine 2 Cutter head 12 Movable spoke 13 Spacer 16 Spare cutter bit

Claims (2)

In the shield excavator that advances excavation in the ground using a cutter bit provided on the front surface of the cutter head, a plurality of spare cutter bits are held on the surface, and movable spokes embedded in the front surface of the cutter head so as to be pushed out. , And an extruding means for extruding the movable spoke to bring the spare cutter bit into contact with the face, and
The pushing means is provided on the back side of the movable spoke so as to be movable in a direction parallel to the back surface, and has a spacer whose upper surface is a slope, and a moving means for moving the spacer in a direction to push the back surface of the movable spoke. The shield excavator is configured to push the movable spoke by moving the spacer after the side surface of the spacer is brought into contact with the side portion or the back surface of the movable spoke.   2. The shield excavator according to claim 1, wherein the spacer has a substantially trapezoidal shape, and after the movable spoke is pushed out, the upper surface comes into contact with the rear surface of the movable spoke, thereby moving the movable spoke when excavating with the spare cutter bit. A shield excavator characterized in that it serves as a support means for supporting spokes so as not to be buried.

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