JPS5920480Y2 - Deep digging blade for gravel layer - Google Patents

Description

[Detailed description of the invention] The present invention relates to a deep digging blade for use in excavating sand and gravel layers. is to provide.

In order to excavate a horizontal shaft in a sand and gravel layer using the conventional shield method, as shown in Figs. Excavation tool A, which is equipped with a cone-shaped deep digging blade e for sand and gravel layers as shown enlarged in Fig. 1, is attached to shield tube B.
By rotating this excavating tool A, the front face G' of the shield tube B is excavated and the horizontal pile H is excavated into the gravel layer G. Since the deep digging blade e for the sand and gravel layer in A is cone-shaped, the sand and gravel layer G may be compact, relatively large-diameter gravel may be mixed in, or the gravel may be located far apart over a long distance. If so, there is a risk that the deep digging blade e for the sand and gravel layer will be worn out or damaged by short-term excavation and become unable to excavate.

In this case, it is natural that the deep excavation blade e for the sand and gravel layer must be replaced, and this replacement work is extremely difficult due to the nature of the shield construction method, and may sometimes endanger the life of the tool.

The purpose of the present invention is to eliminate the drawbacks of the deep digging blade for sand and gravel layers as described above.

Figures 4 and 5 show an embodiment of the deep digging blade for sand and gravel layers according to the present invention. A plurality of plate-shaped chips 4 made of a carbide material such as tungsten carbide are embedded in the arcuate edge 3 at appropriate intervals, with the top 4' and both sides 4'' slightly exposed. It is something.

In order to excavate a horizontal shaft in a sand and gravel layer by the shield method, for example, using the deep excavation blade for sand and gravel layers of the present invention shown in FIGS. 4 and 5, the rotary shaft 6 is and,
A plurality of wings 7 radially attached to this rotating shaft 6,
A rotary cutter 10 consisting of a normal excavation blade 8 attached to each wing 7, a central excavation blade 9, and a deep excavation blade 1 for sand and gravel layer according to the present invention is provided in front of the shield tube 11, and this cutter 10 is rotated. By excavating the face G' and advancing the shield cylinder 11, the gravel layer G is excavated.
A horizontal shaft H is to be excavated inside.

The deep digging blade for sand and gravel layers of the present invention has various excellent effects as described below.

1. The tip surface of the deep digging blade for sand and gravel layers of the present invention, that is, the surface that contacts the sand and gravel layer to be excavated, is an arcuate surface, and this arcuate surface and both sides thereof are covered with plate-shaped chips made of carbide. Since the leading edge and both side edges are exposed, the sand and gravel layer can be excavated easily and smoothly, and there is almost no risk that the deep digging blade will be damaged or worn out.

2. Even if the deep digging blade for sand and gravel layers of the present invention collides with gravel in the sand and gravel layer, the plate-shaped chips made of carbide are almost buried within the plate-shaped main body made of steel plates, etc. The impact force is absorbed by this plate-like main body and can sufficiently compensate for the fragility of the plate-like chip, so there is no fear that the deep digging blade will break due to the above-mentioned impact force.

[Brief explanation of the drawing]

Fig. 1 is a perspective view of a conventional deep digging blade for sand and gravel layers, Fig. 2 is a vertical sectional view of a part of a shield tube equipped with a digging tool to which this deep digging blade is attached, and Fig. 3 is its front view. Fig. 4 is a plan view of one embodiment of the deep digging blade for sand and gravel layers of the present invention, Fig. 5 is a side view thereof, and Fig. 6 is a shield tube equipped with a digging tool to which the deep digging blade for sand and gravel layers of the present invention is attached. FIG. 7 is a longitudinal cross-sectional view of a portion of the same, and FIG. 7 is a front view thereof. 2... Plate-shaped main body, 3... Arc-shaped edge,
4...Plate chip.

Claims (1)

[Scope of utility model registration request] A deep digging blade for sand and gravel layers, which has a plurality of plate-shaped chips made of carbide material embedded at appropriate intervals in the arcuate edge of the tip of a plate-shaped main body made of a fan-shaped or similar shape made of a steel plate, etc. .