JPS6130119B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a shield excavator for excavating a horizontal shaft in soft ground such as ground below the groundwater level. BACKGROUND ART Conventionally, a shield excavator as shown in FIG. 1 has been used when excavating a horizontal shaft in the ground below the groundwater level, where it is difficult for the face to stand on its own, such as in a sand layer or a gravel layer. This conventional shield tunneling machine has shield outer cylinder A.
A watertight partition wall B is provided in front of the partition wall B, and a rotary excavating tool C having cutting blades C ₁ , C ₂ and a kneading tool C ₃ is provided in front of the partition wall B. The main components include a screw conveyor D raised toward the rear of the cylinder A and an oil jack E provided for propulsion of the excavator. By rotating the screw blade _d1 of the screw conveyor D, the screw is discharged to the outside from its discharge port _d2 . In FIG. 1, d ₃ is an outer cylinder of the conveyor, d ₄ is a rotating shaft, and C ₄ and d ₅ are drive motors. If there is coarse gravel in the ground to be excavated, in order to reliably and smoothly discharge the coarse gravel by the screw conveyor D, the effective inner diameter of the outer cylinder _d3 and the effective outer diameter of the screw blade _d1 must be adjusted. The diameter and pitch need to be formed to a sufficient size. For example, in the cross section of the screw conveyor D shown in FIG. 2, the effective inner diameter of the outer cylinder d ₃ is R, and the rotation axis d ₄
When the outer diameter of m is r, the cross-sectional diameter of the gravel m that can be conveyed by this conveyor is R-r/2. Therefore, in order to secure a conveyance space sufficient for passing coarse gravel, the above specifications must be made large enough. This requires the installation of a large screw conveyor, which raises the price of the excavator itself. In view of the above points, the present invention provides a shield excavator suitable for downsizing, which is equipped with an excavated soil discharge device that can reliably and smoothly convey and discharge coarse gravel without making the screw conveyor itself that large. It was made for the purpose of providing. Embodiments of the present invention will be described below with reference to the drawings. Figure 3 is a side sectional view showing an example of the main parts of the shield tunneling machine of the present invention. The structure of the conveyor device is different. That is, in the figure, 1 is a shield outer cylinder, 2 is a watertight partition provided at the front part of the outer cylinder 1, and the front part thereof becomes the face chamber 3. Reference numeral 4 denotes a rotary excavating tool disposed at the front end of the face chamber 3, which includes a number of excavating blades 5 at the front, a coring excavating blade 6 at the center of the front, and a plurality of rod-shaped kneading blades 7 at the rear. is attached to the rotating shaft 8. 9 is a hollow soil conditioner injection pipe formed in the shaft 8 along its length; 10
is an injection hole at the tip of the injection tube. The rotating shaft 8 is supported by a radial bearing 11 of the partition wall 2 and a thrust radial bearing 12 of a drive mechanism provided on the rear surface of the partition wall. The drive mechanism is formed by a reduction gear 13 attached to the rear end side of the rotating shaft 8, a pinion gear 14 meshed with this gear, and a hydraulic motor 15 serving as a drive source to which this gear 14 is attached. Note that 16 is a swivel joint connected to the injection pipe 9 at the rear end of the shaft 8. Reference numeral 17 denotes a discharge device for excavated soil, and this discharge device 17 is a conveyor outer cylinder 1 having an inclination rising from the lower part of the partition wall 2 toward the rear of the shield outer cylinder 1.
8 is provided with its front end communicating with the face chamber 3, and a composite conveying body having a structure in which a spiral rod body 19 and a shaft 21 of a screw blade 20 are connected is housed inside this outer cylinder 18. It is characterized by its structure. That is, the above-mentioned composite conveying body is formed of a helical rod 19 in the first half and a rotary shaft 21 surrounding the screw blades 20 connected to the helical rod 19 and integrated in series in the latter half. 22 is a discharge port provided at the rear part of the outer cylinder 18;
23 is a drive motor connected to the shaft 8 at the rear end of the outer cylinder 18; 24 is a helical rod 19 connected to the outer cylinder 18;
A gravel outlet 25 is a lid for the gravel outlet provided on the upper surface of the outer cylinder where the rear end is located, and thus constitutes an example of the excavated soil discharge device of the excavator of the present invention. In the figure, 26 is a shield jack, and 27 is a segment that is sequentially assembled into a retaining cylinder at the rear of the shield outer cylinder 1. FIG. 4 is a diagram of the above-mentioned discharge device taken along the line - - in FIG. 3, and the shape and size of the outer cylinder 18, which has a spiral body 19 inside that acts as a conveyance means for excavated soil containing gravel, is indicated by the diagonal line. Part 19S marked with
It is expressed in However, since the spiral rod body 19 does not have a through shaft like the shaft 21 of the screw blade that supports its rotation, the size of gravel that can be transported is Even coarse gravel n that is slightly smaller than the effective inner diameter of 18 can be smoothly conveyed. Incidentally, in the conventional screw conveyor shown in FIG.
It is possible to transport only up to the size of gravel m, which is calculated by subtracting this value and dividing this by 2. The operation mode of the above-mentioned excavator according to the present invention is as follows. For example, when excavating a gravel layer containing coarse gravel,
By rotating the excavator 4 , the face is excavated and the excavated earth and sand is stored in the face chamber 3. During excavation, a soil improver such as clay, bentonite, or CMC is added to the excavated soil through the injection hole 10, and is further mixed throughout the face chamber 3 under the action of the mixing blades 7 to improve plastic fluidity. It is made into mud that is impermeable and has a unit volume weight (1.6 to 2.0 t/m ² ) that is approximately the same as that of the geological formation, and a water content ratio that is approximately the same as that of the earth. This mud fills the face chamber 3 and the outer cylinder 18 of the discharge device, and its earth pressure counteracts the earth pressure and water pressure of the face, thereby maintaining the face in a stable state during excavation. If coarse gravel is included in the mud, the gravel is removed from the conveyor outer cylinder by the rotation of the spiral rod 19.
8, but the movement is stopped at the rear end of the rod 19, that is, at the front end of the screw blade 20. In other words, the coarse gravel may be prevented from moving toward the screw conveyor by the screw blade 20, so open the lid 25 of the gravel outlet 24 and remove the stagnant gravel. It is. In addition, since the spiral rod 19 has a kneading function as well as a moving function, the portion of the rod 19 and the rod 19
At the joint between the screw blade 20 and the screw blade 20, no stagnation occurs except for the coarse gravel. That is, the mud from which gravel has been removed is discharged from the rear end discharge port 22 of the conveyor outer cylinder 18, as in the case of the conventional machine. 5 and 6 are side sectional views showing shield tunneling machines according to other embodiments of the present invention, and therefore, to avoid duplication of explanation, components different from those of the embodiment shown in FIG. 3 are shown. I will only explain about. Therefore, the same reference numerals as in FIG. 3 indicate the same members. This excavator consists of the one shown in Figure 3 and the excavator 4.
A rotating support structure, a kneading means provided integrally with the core excavation blade, and a kneading means housing the kneading means, and a face chamber 3.
The structure of the sediment chamber formed by communicating with each other is different. That is, the digging tool 4 has its rear surface attached to a rotary cylinder 82 which is supported by the partition wall 2 with a seal/bearing 11 via a connecting rod 81.
2, an annular reduction gear 13' provided on the rear surface is connected to a hydraulic motor 15 as a rotational drive source via a pinion gear 14.
It is connected to the. Next, on the coaxial rear side of the core cutting blade 6 which is fixed to the digging tool 4 and rotated together with it, there is a kneading tool having a spiral rod body extending rearward through the inside of the rotary cylinder 82. 71 is attached, and the rear end is
Bearing 12' on the rear wall of the earth and sand chamber 31 to be described later.
It is pivoted through. The kneading tool 71 is connected to the rotating cylindrical body 8.
By loosely inserting its tip tightly into the inner wall surface of the partition wall 2, the dirt chamber 31 is communicated with the face chamber 3 and protrudes from the rear of the partition wall 2, and the inside thereof is hollow. It is now possible to inject soil conditioners. The sediment chamber 31 is formed in a storage portion 32 whose rear end side bulges downward, and a sediment discharge device having the same configuration as that described in the previous embodiment is connected to this storage portion 32 through a gate 33. As described above, another example of the shield tunneling machine according to the present invention is constructed. Therefore, the operation of the shield excavator of the above-described example is such that after the excavated soil is mixed by the mixing blades 7, it is further conveyed from the soil chamber 31 to the storage section 32, while the helical rod is kneaded. The mixture is moved from the front to the rear while being mixed by the mixing tool 71. here,
Even if there is coarse gravel in the excavated soil, the kneading tool 71 in the soil chamber 31 does not have a through shaft on its central axis.
It is possible to encourage and promote the turning of excavated soil into mud while sending gravel backwards. Then, the mud containing gravel passes through the gate 33 from the storage section 32 of the sand chamber 31, and is transported rearward by the discharge device as in the previous embodiment, and the coarse gravel is taken out from the outlet 24, leaving only the mud. The soil is discharged to the outside from the soil discharge port 22 at the rear end of the conveyor outer cylinder. The present invention is as described above, and provides a discharge device for excavated soil of a shield excavator, in which a composite type transport body formed by a screw blade and a helical rod body connected in series to the shaft thereof is conveyed onto a single conveyor. Since the coarse gravel is housed in the outer cylinder and the outlet for the coarse gravel is provided in the outer cylinder where the rear end of the spiral rod-shaped body is located, the coarse gravel can be easily introduced into the discharge device even when the size is reduced. ,
Moreover, while the gravel can be conveyed through the device and taken out during the process, the coarse gravel cannot move toward the screw blade, so the gravel can be effectively removed. In addition, the discharge device itself may be as large as the conventional machine, and if the front half of the screw conveyor of the conventional machine is replaced with a spiral rod and gravel removal holes are provided in the outer cylinder, the present invention can be used. The invention also has economic benefits that can be obtained by making slight modifications to conventional machines.

[Brief explanation of the drawing]

Fig. 1 is a side sectional view showing an outline of a conventional shield excavator, Fig. 2 is an enlarged cross-sectional view taken along the line - - in Fig. 1, and Fig. 3 is a side sectional view of an embodiment of the shield excavator according to the present invention. , FIG. 4 is an enlarged cross-sectional view taken along the line - in FIG. 3, and FIG. 5 is a side sectional view of the embodiment of the present invention.
FIG. 6 is a front view. 1... Shield outer cylinder, 2... Partition wall, 3... Face chamber, 4
...Drilling tool, 5...Drilling blade, 6...Coring drilling blade, 7...Kneading blade, 8...Rotating shaft, 9...Soil conditioner injection pipe, 10
...Injection hole, 11, 12...Bearing, 13...Reduction gear,
14... Pinion gear, 15... Hydraulic motor, 16...
Swivel joint, 17 ...Discharge device, 18...Conveyor outer cylinder, 19...Spiral rod body, 20...Screw blade, 21...Screw blade shaft, 22...Discharge port,
23... Drive motor, 24... Gravel outlet, 25... Lid,
26...Shield jack, 27...Segment.

Claims (1)

[Scope of Claims] 1. The front of the shield outer cylinder is partitioned by a watertight partition wall, the front of the shield is defined as a face chamber, an appropriate excavation blade is provided on the front surface of the face chamber, and the shield is connected to the face chamber and is connected to the face chamber. In a shield excavator equipped with an excavated soil discharge device disposed toward the rear of the shield outer cylinder, a conveyor cylinder communicating with the face chamber has a helical rod at the front and a screw blade at the rear. A composite type of conveyor formed by the above is rotatable and stored in series, and a gravel outlet that can be opened and closed is formed on the wall surface of the conveyor cylinder where the rear end of the spiral rod is located. A shield excavator characterized by being equipped with a discharge device. 2 In the above-mentioned excavated soil discharge device, the conveyor outer cylinder is formed into a sand chamber with its front side substantially horizontal, and has a rear end that is inclined upwardly toward the rear with a drop at the rear end of the sand chamber. On the other hand, the earth and sand chamber rotatably accommodates a helical rod whose front end is connected to the axis of a cored excavator blade, and the rear inclined part of the outer cylinder has a front half connected 2. The shield excavator according to claim 1, wherein the shield excavator is equipped with a composite conveyor in which a portion comprises a helical rod and a rear portion comprises a screw blade.