JPS622117B2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a mud-forming material injection device for a shield excavator, and its purpose is to inject mud-forming material such as a plastic fluidization improver into excavated soil taken into the back of a cutter head. To ensure reliable injection of sludge by reducing the factors that increase the rotational resistance of the cutter head as much as possible by shortening the length of the sludge material injection pipe.

In a shield excavator, a mud preparation material such as a plastic fluidization improver is injected and mixed into the excavated soil taken into the back of the cutter head, and the excavated soil is made plastic and discharged. Conventionally, as a method for injecting mud-making material into excavated soil, a method has been proposed in which mud-making material injection paths are provided inside the rotating central axis of the cutter head or the stationary part of the shield body, and the mud-making material is injected through these injection paths. . In this case, the former has a rotary joint interposed at the connection to the fixed mud-making material supply pipe, and the latter has mud-making material injection points fixed at multiple locations on the shield body. By the way, it is better to inject the mud material into the upper part of the cut head as much as possible to have a better mixing effect with the excavated soil (sufficient mixing is achieved while it falls due to gravity). In addition, if the slurry injection pipe is simply connected to the fixed bulkhead in the center of the cutter head, the slurry material cannot be injected into the upper part, as described above, and the mixing effect with the excavated soil will be poor. However, in order to inject the mud material into the upper part of the cutter head as much as possible, it is necessary to prevent the mud material injection path from interfering with other equipment, which inevitably results in a long mud material injection path. Furthermore, as described above, the piping constituting the sludge material injection path must be fixed at many locations, which inevitably increases the number of curved sections. For this reason,
As the length and curved portion of the pipe increases, the resistance of the pipe increases, making it difficult to feed the slurry material into the cutter head sufficiently. Therefore, the amount of mud material in the excavated soil is reduced, which has the drawback of increasing the rotational resistance of the cutter head.

The present invention has been made in view of the above, and examples thereof will be described below.

Reference numeral 1 denotes a cutter head, which has a cylindrical surrounding wall 2 on its back surface, and this surrounding wall 2 is pivotally supported at the front part of the shield body 3 via a bearing 4 or the like. In the surrounding wall 2, a cylindrical body 5 is inserted and fixed in the center of the rear plate 2A. On the other hand, a case 6 is provided on the shield main body 3 via a support member (not shown). The case 6 consists of an outer cylinder 6A, an inner cylinder 6B, a front plate 6C, and a rear plate 6D, and has an annular mud-making material storage chamber 7 inside thereof.
The casing 6 is concentrically fitted into the cylindrical body 5 via a bearing 8, a seal 9, etc. Reference numeral 10 denotes a screw conveyor for soil removal, which includes a casing 10A and a ribbon screw feeder 10B. That is, the casing 10A has one end fitted and held in the casing 6.
The inside of 0A is communicated with the excavated soil intake chamber 11 inside the surrounding wall 2, and has a soil discharge port (not shown) at the rear thereof. Further, the rear end of the ribbon screw feeder 10B is connected to a rotary drive motor (not shown) provided in the casing 10A, and its tip portion is made to protrude into the center of the excavated earth and sand intake chamber 11.

On the other hand, a plurality of sludge material injection pipes 12 are provided on the outer periphery of the excavated soil intake chamber 11 at required pitches (equal pitches) in the circumferential direction of the intake chamber 11 . The tips of these mud making material injection pipes 12 are opened toward the inside of the excavated soil intake chamber 11 on the back side of the face plate of the cutter head 1, and a blocking prevention plate 13 is provided at the tip opening 12A. The rear end of the sludge material injection pipe 12 penetrates the rear plate 2A of the surrounding wall 2,
It is connected to a hole 14 bored in the cylinder 5. On the other hand, an elongated hole 15 is formed in the outer cylinder 6A of the case 6 over approximately the upper half circumference thereof. That is, this elongated hole 15 is formed along the rotation path accompanying the rotation of the cutter head 1 of the base end opening 12B of the mud making material injection pipe 12.
5 corresponds to the base end opening 12B of the slurry material injection pipe.
Then, on both sides of the elongated hole 15, the cylinder body 5 and the case body 6
A sealing O-ring R is interposed between the two. 16
is a mud-making material supply pipe, which is connected to the mud-making material storage chamber 7 inside the casing 6. In the illustrated example, in addition to this, a mud preparation material injection pipe 17 that penetrates the case 6 is provided.

According to the above, when the mud making material injection pipe 12 rotates together with the cutter head 1, the base end opening 12B of the mud making material injection pipe 12 is inserted through the elongated hole 15 of the casing 6 in the upper half circumference of the rotation path. It communicates with the mud storage chamber 7. Therefore, during this period, the mud making material is injected into the excavated soil intake chamber 11 from the tip opening 12A of the mud making material injection pipe 12. However, in the lower half of the rotation path, the base end opening 12B of the slurry material injection pipe 12 is closed by the outer cylinder 6A of the case 6, so no injection is performed. Since a plurality of mud-making material injection pipes 12 are provided, the mud-making material is always injected into the excavated soil intake chamber 11 in the upper half circumference thereof.

In FIG. 4, the sludge material injection pipe 18 is constructed of a straight pipe, and a ball valve 19 is interposed at the rear end, and a hole 1 of the cylindrical body 5 is inserted in the middle of the pipe.
4 is connected. 20 is a connecting pipe.
According to this, when the mud-making material injection pipe 18 becomes clogged, the ball valve 19 is opened and a rod (not shown) is inserted from the rear end of the mud-making material injection pipe 18.
Alternatively, by spouting jet water at the same time, the inside of the pipe can be easily cleaned and washed.

As is clear from the above description, according to the present invention, the mud material can be constantly injected into the upper part of the excavated soil intake chamber, so that the mud material and the excavated soil can be mixed effectively. In addition, the mud-making material is injected through the mud-making material storage chamber in the casing fixed to the shield main body side and the mud-making material injection pipe whose base end opening faces the mud-making material storage chamber. As a result, the length of the pipe and the number of bends can be reduced compared to the case where the entire length of the pipe is piped, which reduces piping resistance and allows for sufficient injection of mud material, reducing the increase in rotational resistance of the cutter head. It can be suppressed.

[Brief explanation of the drawing]

1 to 3 show embodiments of the present invention, FIG. 1 is a longitudinal sectional view, FIG. 2 is a cross-sectional view taken along line A-A in FIG. 1, and FIG. 3 is a cross-sectional view taken along line B-B in FIG. FIG. 4 is a longitudinal sectional view showing the main part of a modification. 1... cutter head, 2... enclosing wall, 3...
Shield body, 6... Linkage, 7... Sludge material storage chamber, 11... Excavation soil intake chamber, 12, 18... Sludge material injection pipe, 12A... Tip opening, 12B...
Base end opening, 15...long hole.

Claims (1)

[Claims] 1. A cutter head having a surrounding wall on the back and an excavated soil intake chamber formed inside the surrounding wall is pivotally supported at the front part of the shield body, and an annular mud-making material storage to which a mud-making material supply pipe is connected. A case having a chamber is fixed to the shield body side at the rear of the cutter head, and a plurality of mud-making material injection pipes are provided in the cutter head and open at required pitches in the circumferential direction inside the excavated soil intake chamber, and the mud-making material is injected into the cutter head. A sludge material injection device for a shield excavator, characterized in that an elongated hole facing the base end opening of the injection pipe is formed in the upper part of the outer wall of the casing along the rotation path of the base end opening.