JPS632548Y2 - - Google Patents

Description

[Detailed description of the invention] This invention relates to an earth auger screw for drilling holes in troubled ground, and its purpose is to use earth auger screws when excavating troubled ground where obstacles such as existing foundations and rock layers are buried. To provide a drilling blade for drilling holes in troubled ground, which can be attached to the tip of a shaft and used to effectively excavate a specific troubled ground.

The inventor has continued to research methods and equipment for excavating so-called obstructed ground, such as the foundations of existing buried structures or rock layers, and has already clarified the details. A specific earth auger excavator equipped with a drilling blade 3 equipped with a superalloy bit on the tip 2a of a screw head 1 wound around the outer periphery of a screw head 1 as shown in Figure 1 is capable of excavating faulty ground. It has become clear that holes can be made.

Especially such earth auger excavator is the first
As shown in Figure B, the digging blade 3a on the outer circumferential side of the screw thread 2 is made into the largest shape according to its circumferential speed, and then the digging blade 3b on the inside is made into the next largest shape, and the shape of the digging blade is changed sequentially to match the circumferential speed. It is characterized by having a suitable shape.

However, although the screw head 1 of the previously proposed earth auger excavator is effective to a certain extent in drilling through faulty ground, its effectiveness may be insufficient depending on the content of the faulty ground. There were times when I was unable to demonstrate my full potential.

In other words, the compressive strength of the faulty ground, especially the rock layer, is generally in the range of 800Kg/cm ² to 2800Kg/cm ² , but even with such variations, depending on the type of rock, the first The already designed head shown in the figure can be used to sufficiently drill holes. For example, if the compressive strength of igneous rock is relatively high at 2000 kg/ ^cm2 , but the rock layer has brittle characteristics, the drilling stone can be used in the form of a quartz stone. As a result, the rock was successfully drilled to the desired depth.

However, in the case of metamorphic rocks, sedimentary rocks, etc. where the compressive strength of the rock layer is high and the rock properties are uniform in hardness, such as metamorphic rocks and sedimentary rocks, the drilling stone cannot be drilled into a quartz-like shape, and the drilling stone is in the form of powder, such as sand or pebbles. Since the drilling blade 3 has a large contact area with the rock, the hole continues to be drilled in a state of polishing, and the wear of the drilling blade 3, especially the bit, is very severe, and the screw is worn out during the excavation process. It was necessary to raise the head 1 to the ground and repeatedly remove and replace the excavation blade 3.

In addition, in the abrasive excavation process, as shown in Fig. 2, part of the cutting edge 3a of the excavation blade 3 may bite into a crater 5 in the bedrock at the bottom of the excavation hole 4. There was a drawback that the rapid deformation of the drilling contact surface of the cutting edge that bit into the crater 5 applied an impact as concentrated stress to the drilling blade 3, damaging the cutting edge and reducing the drilling ability.

The reason why such a crater 5 occurs is not necessarily clear, but according to the inventor's knowledge, for example, if the bedrock has a fault shape, a crater may be created on the fault plane, or when the rock is in a uniform bedrock layer. It is assumed that this is because other soft rocks are partially mixed in.

This invention was made to improve these drawbacks, and is shown in Figure 3 A, B and Figure 4 A, B below.
An embodiment of this invention will be described based on the following.

In the drawing, reference numeral 6 denotes a drilling blade for drilling holes in disturbed ground according to an embodiment of this invention, and the shank base 7 of this drilling blade 6 is bifurcated with a U-shaped side surface. At least two through holes 8 for attaching bolts are formed so as to be perpendicular to the axis l of the excavating blade 6 , spanning the two prongs.

In addition, in this invention, a through hole 8 for attaching a bolt is provided.
does not necessarily have to be provided. Through hole 8
In the embodiment in which the shank base 7 is not drilled,
You can weld them directly.

9 is a shank tip, and the shank tip 9 has an inverted U-shape on the side and has free ends 10, 10a, 10, respectively.
Superalloy bits 11, 11a, and 11b are attached to b.

With this invention, the shank tip 9 is connected to its free end 1.
When the bit 11 installed at
The bits 11, 11a, and 11b are shaped so that their tips are aligned on the horizontal line H with respect to this angle.

4A and 4B are explanatory diagrams of the usage state of the excavating blade 6 according to this invention, and in this embodiment, the excavating blade 6 is an end portion of the screw thread 2 wound around the outer periphery of the screw head 1. Bolt nut 1 to 2a
2 is tightened and fixed.

As shown in FIG. 4B, the mounting position of the excavating blade 6 according to this invention is preferably at position A on the outermost periphery of the end 2a of the screw thread 2 and position B on the inner side thereof, and its shape is also located at the position It is desirable to increase A, B, and C in this order in accordance with the circumferential speed and torque. In addition, the ordinary digging blades 13 and 14 shown in FIG. 5 A and B may be attached to the positions B and C in FIG. .

The drilling blade 6 for drilling holes in disturbed ground according to this invention having such a configuration can be used as an earth auger excavator for drilling holes in ground where a bedrock layer is buried as an obstacle.
When this drilling blade 6 is installed, the bit 11 is attached in a saw-blade shape in double against the drilling direction surface of the obstacle, so that the contact surface of the drilling blade 6 is on the drilling path circumference of the drilling surface. This means that the contact surface is twice as large as that of the conventional method, and even when the rock is crushed into abrasive shapes and the cutting edge 3 bites into the crater 5 after the grinding and crushing, impact force is applied to the excavating blade 6 . ,
Bits 11 and 11b that are forward in the direction of travel
Since the bits 11 and 11a provided at the rear come into contact with other crushed obstacles, the biting of the bit 11b in front is weakened, which weakens the impact and reduces the drilling ability. This will improve the results.

By showing examples and comparative examples of the excavating blade according to this invention, the effects of the excavating blade according to this invention will be made clearer.

Example As shown in Figure 6, the area from the ground surface to a depth of 2 m is soft surface soil A, and from 2 m below this surface soil A to a depth of 2 m.
Up to 3.5m is weathered rock layer B, from depth 3.5m to depth 8.0
When an earth auger excavator equipped with a drilling blade according to this invention was used to excavate a geological layer that was bedrock layer C (mudstone) up to a depth of 500 m, continuous drilling was completed in approximately 5 hours.

See Figure 6.

Comparative Example As shown in Fig. 7, a hole was drilled in the same stratum as in the example in exactly the same manner as in the example except that an earth auger excavator equipped with the previously designed auger screw head shown in Fig. 1 was used. Although surface soil layer A and weathered rock layer B were successfully excavated, the bit broke during the excavation after 4 hours and 11 hours, and it took 2 hours each and 4 hours in total to replace the excavation blade. After that, drilling continued and the hole was drilled to a depth of approximately 8m approximately 16 hours after the start of drilling.

As is clear from the above results, the drilling blade for drilling in troubled ground according to this invention has an extremely excellent drilling effect in troubled ground, and is effective even when the obstacle is a bedrock layer or a reinforced concrete layer. It can be seen that this is a digging blade that can demonstrate the following.

[Brief explanation of drawings]

1A and 1B are explanatory diagrams of a conventional example, FIG. 2 is an explanatory diagram of the usage state of the conventional example, and FIG. 3A is a side explanatory diagram of a drilling blade for drilling holes in troubled ground according to an embodiment of this invention;
FIG. 3B is a bottom view of a drilling blade for drilling holes in troubled ground according to an embodiment of this invention, and FIG. 4A is an explanatory diagram of the installation state of the drilling blade for drilling holes in troubled ground according to an embodiment of this invention. , FIG. 4B is an explanatory view showing the mounting position of the excavation blade for drilling holes in disturbed ground according to an embodiment of this invention, FIGS. 5A and B are side views of the conventional excavation blade, and FIG. An excavation state diagram of the excavation blade of one embodiment of this invention according to the embodiment, and FIG. 7 is an excavation state diagram of a conventional example. 6 ...Drilling blade, 7...Shank base, 9...Shank tip, 10...Free end, 11...Bit.

Claims (1)

[Scope of utility model registration request] A drilling blade for drilling holes in troubled ground, in which the base of the shank is bifurcated with a U-shaped side surface, the tip of the shank is shaped like an inverted U-shape on the side, and a bit is attached to each free end of the tip.