JP5004474B2 - Multi-axis auger device - Google Patents

Description

  The present invention relates to a multi-axis auger device for drilling ground in the construction of soil cement underground continuous walls.

  Conventionally, a soil cement underground continuous wall (SMW) is created using an earth auger excavator. As this earth auger excavator, for example, as shown in FIGS. 4 and 5, there is one using a three-axis auger device 21 equipped with three auger shafts 22 a to 22 c arranged in parallel. The auger shafts 22a to 22c have auger heads 23a to 23c provided at the tips and rods 24a to 24c connected to the auger heads 23a to 23c. Then, the auger shafts 22a to 22c are rotated by the drive device 29 to inject and knead the solidified material while excavating the ground, thereby forming the underground continuous wall. In FIG. 5, a two-dot chain line R2 represents the excavation diameter.

By the way, the soil cement underground continuous wall construction method has become popular as an effective construction method for water blocking walls due to its inexpensive construction cost and wide application range, and it is required to increase the depth of construction and further improve the water stopping performance. Yes. In response to these needs, in recent years, excavation is widely performed while monitoring excavation accuracy (see, for example, Patent Document 1). Furthermore, construction apparatuses capable of correcting the excavation direction according to the detection result are being developed (see, for example, Patent Document 2).
JP-A-1-278687 JP 2002-266370 A

  However, the auger shaft is generally configured to have a length necessary for construction by connecting rods having a diameter of 200 to 300 mm and a length of 5 to 10 m to each other. Therefore, even if a high-accuracy monitoring system and an excavation direction correcting device are provided, there has been a drawback that it is difficult to continue a desired operation due to elastic deformation of the rod or looseness of the joint portion. In addition, there is a drawback that the excavation performance is lowered by providing a correction device in the vicinity of the excavation tip. In addition, these devices are expensive and require careful attention to maintenance.

  An object of the present invention is to increase excavation accuracy and reduce the construction cost by suppressing elastic deformation of a rod and looseness of a joint portion in a multi-axis auger apparatus.

In order to solve the above problems, the invention described in claim 1 is connected to an auger head 3a-c provided at the tip and above the auger head 3a-c, for example, as shown in FIGS. A multi-axis auger apparatus 1 for excavating the ground by arranging a plurality of auger shafts 2a-c having rods 4a-c and rotating each auger shaft 2a-c, around each of the rods 4a-c Casing 5a-c through which this is inserted is equipped, the external shape of the cross section of these casings 5a-c is formed in noncircle, and a part of those rotation locus overlaps adjacent casings 5a-c. is disposed so as, the outer shape of the cross section of the casing 15a~c is formed and a convex portion 17 and concave portion 18, a casing 15a~c the adjacent convex portions at a position where their rotation locus overlap And 7 and the recess 18 is equal to or adapted to face.

In this way, the casings 5a to 5c having a non-circular outer cross-sectional shape are inserted into the rods 4a to 4c, and the adjacent casings 5a to 5c are overlapped with each other so that a part of the rotation locus (excavation diameter R) overlaps. By disposing, the multi-axis auger apparatus can be equipped with casings 5a to 5c having a larger cross-sectional performance than conventional rods. Therefore, even when deeply excavating the ground, the elastic deformation generated in the casings 5a to 5c is small, and the amount of bending and twisting of the excavation hole can be reduced. Moreover, since the joint part of casing 5a-c becomes larger than the joint part of rod 4a-c, the displacement angle which generate | occur | produces by the backlash can also be made small. And since construction with a small displacement can be performed, the initial cost and running cost of a multi-axis auger apparatus can be reduced, without using the expensive monitoring system and correction apparatus like the past.
Moreover, the casing 15a-c which formed the outer shape of the cross section with the convex part 17 and the recessed part 18 is inserted in each rod 4a-c, and the adjacent casing 15a-c is a rotation locus (excavation diameter R1). By making the convex portion 17 and the concave portion 18 face each other at a position where the portions overlap, the outer shapes of the casings 15a to 15c can be further increased, and the cross-sectional performance can be further improved.

  According to the present invention, in the multi-axis auger apparatus, the rod connected to the upper side of the auger head provided at the tip is inserted, and the outer shape of the cross section is equipped with the casing formed in a non-circular shape. Since the matching casings are arranged so that their rotation trajectories partially overlap, it is possible to excavate the ground with a casing having a larger cross-sectional performance than conventional rods. For this reason, at the time of long construction, a deformation | transformation of a rod etc., the displacement by the play of a joint part, etc. can be suppressed slightly, the bending of an excavation hole and a twist can be made small. Then, by performing construction with a small displacement, an expensive monitoring system and a correction device as in the prior art are unnecessary, and the cost of construction using a multi-axis auger device can be reduced.

Hereinafter, the best mode for carrying out the present invention will be described in detail with reference to the drawings.
The multi-axis auger device according to the present embodiment is provided in an earth auger excavator (agitating and kneading machine) that is used to construct a soil cement underground continuous wall, and is suspended and supported by a leader supported by a crawler crane, for example. Is.

  As shown in FIG. 1, the multi-axis auger apparatus 1 includes three auger shafts 2a to 2c arranged in parallel with each other at a required interval. Each auger shaft 2a-c has an auger head 3a-c provided at the tip thereof, and a rod 4a-c connected above the auger head 3a-c. Furthermore, the multi-axis auger apparatus 1 is equipped with casings 5a to 5c through which the rods 4a to 4c are inserted. And each auger shaft 2a-c and each casing 5a-c are droopingly connected by the drive device 9 so that each upper end part can be rotationally driven. The rods 4a to 4c and the casings 5a to 5c are configured by connecting an appropriate number of rods.

  The auger shafts 2a to 2c are formed in a hollow shape as in the prior art, and a solidified material or the like can be injected into the excavation hole from the hollow portion during excavation. Similarly to the conventional auger heads 3a to 3c, the auger head 3b of the central auger shaft 2b is positioned higher than the auger heads 3a and 3c of the auger shafts 2a and 2c on both ends so that they do not interfere with each other.

  The casings 5a to 5c are made of steel or the like and have a cylindrical shape, and cylindrical casing heads 6a to 6c are provided at the ends of the casings 5a to 5c. With the casing heads 6a to 6c, the ground can be cut into a donut shape and excavated. The inside of the donut shape can be excavated by the auger heads 3a to 3c. Further, the lower ends of the casings 5a and 5c on both ends are formed with a small diameter so as not to interfere with the rotation of the central casing head 6b.

  The outer shape of the transverse cross section of the casings 5a to 5c (the cross section perpendicular to the axial direction of the casings 5a to 5c) is non-circular so that the casings 5a to 5c do not interfere with each other. And the adjacent casings 5a-c are arrange | positioned so that a part of those rotation locus may overlap.

  Specifically, as shown in FIG. 2, the outer shape is formed in a substantially square shape with four apexes 7 and sides 8 respectively. And as for the adjacent casings 5a-c, the top part 7 and the edge part 8 oppose in the position where those rotation locus | trajectories overlap. Each top portion 7 is formed in a convex arc shape toward the outside. A two-dot chain line R in FIG. 2 represents the excavation diameter.

  Here, although the internal structure of the driving device 9 is not shown, the auger shafts 2a and 2c on both ends are rotationally driven in the same direction, and the central auger shaft 2b is rotationally driven in the opposite direction. The casings 5a to 5c can be driven in the same manner. Further, the rotation directions can be reversed, and the auger shafts 2a to 2c and the casings 5a to 5c can be rotated in opposite directions.

  Using the multi-axis auger devices 1 and 11 having such a configuration, the auger shafts 2a to 2c and the casings 5a to 5c are rotated to excavate the ground with the auger heads 3a to 3c and the casing heads 6a to 6c. A soil cement underground continuous wall is formed by injecting and kneading the solidifying material.

  In another embodiment shown in FIG. 3, the outer shapes of the cross sections of the casings 15 a to 15 c are formed so as to be rotationally symmetric with four convex portions 17 and concave portions 18 alternately. The adjacent casings 15a to 15c are configured such that the convex portion 17 and the concave portion 18 face each other at a position where their rotation trajectories overlap. In addition, the convex part 17 and the recessed part 18 are each formed in the circular arc shape convex toward the outer side and the inner side. A two-dot chain line R1 in FIG. 3 represents the excavation diameter. Other configurations are the same as those of the multi-axis auger apparatus 1 shown in FIGS.

  According to the above embodiment, the outer shape of the transverse cross section of the casing is formed in a non-circular shape, and the casings 5a to 5c that are adjacent to each other by inserting such casings 5a to 5c and 15a to c into the rods 4a to 4c, The multi-axis auger apparatus 1 is provided with casings 5a to 5c and 15a to c having a larger cross-sectional performance than the conventional rods 4a to 4c and 14a to c. is doing. Therefore, even when deeply excavating the ground, the elastic deformation generated in the rods 4a to c and 14a to c and the casings 5a to c and 15a to c is reduced, and the bending amount of the excavation hole and the displacement amount of torsion are reduced. be able to. Moreover, since the joint part of casing 5a-c, 15a-c becomes larger than the joint part of rod 4a-c, 14a-c, the displacement angle which generate | occur | produces by the backlash can also be made small. And since construction with a small displacement can be performed, the initial cost and the running cost of the multi-axis auger devices 1 and 11 can be reduced without using an expensive monitoring system and correction device as in the prior art.

  Further, when the outer shape is formed with the convex portion 17 and the concave portion 18, and the adjacent casings 15a to 15c are opposed to each other at a position where a part of the rotation locus overlaps, the convex portion 17 and the concave portion 18 face each other. Further, the outer shape of the casings 5a to 5c can be increased, and a larger cross-sectional performance can be obtained.

  Conventionally, prior drilling with a multi-shaft type is sometimes performed as a guide hole with a single-shaft type. However, the increased drilling accuracy eliminates the need for prior drilling and greatly reduces the overall construction cost. can do.

  In the above embodiment, the multi-axis auger device of the present invention is used to create a soil cement underground continuous wall. However, the present invention is not limited to this, and methods such as foundations, ground improvement, etc. You may use for. Further, the number of auger shafts and casings is not limited to three, and may be two or a plurality of four or more. Furthermore, the shape of the casing may be a triangle other than a square, or a polygon such as a pentagon, and the shape and number of convex portions and concave portions may be appropriately changed. In addition, it is needless to say that specific detailed structures and the like can be appropriately changed.

It is a front view which shows the structure of the multi-axis auger apparatus which concerns on one embodiment to which this invention is applied. It is AA sectional drawing of FIG. It is sectional drawing equivalent to the AA position of FIG. 1 in the multi-axis auger apparatus which concerns on other embodiment. It is a front view which shows the structure of the conventional multi-axis auger apparatus. FIG. 3 is a cross-sectional view of FIG. 2.

Explanation of symbols

1, 11, 21 Multi-axis auger devices 2a to c, 22a to c Auger shafts 3a to c, 23a to c Auger heads 4a to c, 14a to c, 24a to c Rods 5a to c, 15a to c Casings 6a to c Casing head 7 Top part 8 Side part 17 Convex part 18 Concave part 9, 29 Driving device R, R1, R2 Excavation diameter

Claims (1)

A multi-axis auger device for excavating the ground by arranging a plurality of auger shafts having an auger head provided at the tip and a rod connected above the auger head and rotating each auger shaft,
Equipped with a casing through which each rod is inserted,
The outer shape of the cross section of these casings is non-circular,
Adjacent casings are arranged so that some of their rotation trajectories overlap ,
The outer shape of the cross section of the casing is formed with a convex portion and a concave portion,
The multi-axis auger device is characterized in that the adjacent casings are configured such that the convex portions and the concave portions face each other at positions where their rotation trajectories overlap .

Images