JP2003064659A - Excavating device for soil improvement - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an excavating device for soil improvement, which can make a larger-diameter excavated hole. SOLUTION: In this excavating device, hollow auxiliary rotating shafts 7L and 7R, which are shorter than a hollow main rotating shaft 5, are provided in such a manner as to be arranged on both sides of the rotating shaft 5 whose lower end is equipped with a main excavating blade 11 with a small diameter; the vicinities of lower parts of the rotating shafts 5, 7L and 7R are provided in such a manner as to be supported rotatably by a separation maintaining member 27; auxiliary excavating blades 11L and 11R with a small diameter are provided at lower ends of the respective rotating shafts 7L and 7R; auxiliary enlarged excavating blades 17L and 17R with a large diameter are provided on upper sides of the excavating blades 11L and 11R; an enlarged excavating blade 17 with a large diameter is provided in the rotating shaft 5 in a position approximately as high as positions of the excavating blades 11L and 11R; agitating blades 29, 29L and 29R for agitating excavated soil are provided in the rotating shafts 5, and 7L and 7R, respectively; and the rotating shaft 5 and the respective rotating shafts 7L and 7R are rotated in mutually opposite directions.

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a land improvement excavator used in the CSL method as one of the methods for improving soft ground, and more particularly to a conventional excavator. The present invention also relates to an excavator capable of excavating a larger diameter. 2. Description of the Related Art For example, Japanese Utility Model Publication No. Sho 58-33139 discloses a prior art of the present invention. [0003] In the above-mentioned prior art, two rotary shafts having a cutting edge at the lower end and a plurality of stirring blades at an intermediate height are provided in parallel. is there. That is, in the above configuration, a larger diameter excavation can be performed than when excavation is performed using a single rotating shaft. Therefore, by excavating a large number of rotary shafts having the same configuration in parallel and performing excavation at the same time, it is possible to perform excavation of a larger diameter.
In addition to the problem that the straightness when excavating vertically may cause a problem, and the fact that the diameter of the excavating blade and the stirring blade is almost equal, the load on the excavating blade is large and there is a problem to be further improved in extending the life. . SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems, and is provided on both sides of a hollow main rotating shaft having a small-diameter main excavating blade at a lower end portion. A hollow sub-rotation shaft shorter than the main rotation shaft is arranged and provided, and a lower portion of the main rotation shaft and each sub-rotation shaft is rotatably supported by a separation holding member, and a lower end of each sub-rotation shaft A small-diameter sub-drilling blade is provided in the portion and a large-diameter sub-enlarged drilling blade is provided above the sub-drilling blade, and a large-diameter enlarged drilling blade is provided on the main rotating shaft at a height substantially equal to the sub-drilling blade. A stirring blade for stirring the excavated soil excavated on the main rotary shaft and each sub rotary shaft, and configured to rotate the main rotary shaft and each sub rotary shaft in opposite directions. Referring to FIG. 1, a ground improvement excavator 1 according to an embodiment of the present invention is a rotary driving device which is hung on a tip of a boom of a crane (not shown). 3 is provided with a main rotating shaft 5 suspended vertically, and left and right sub-rotating shafts 7L and 7R are vertically provided on both sides of the main rotating shaft 5. The rotary drive device is for rotating the main rotary shaft 5 and the sub rotary shafts 7L and 7R, and is provided with an appropriate number of drive motors and an appropriate speed reduction mechanism. 5 and the auxiliary rotation shafts 7L and 7R are configured to rotate in mutually opposite directions. The main rotary shaft 5 is a hollow rotary shaft and is provided longer than the left and right sub rotary shafts 7L and 7R.
A small-diameter inclined plate 9 helically inclined with respect to the main rotating shaft 5 is attached to a lower end portion of the main rotating shaft 5. Tooth 13
It has. And, on the lower end surface of the main rotating shaft 5,
A baffle plate 15 is provided to prevent soil or the like from entering the slurry discharge port opened at the lower end surface. At a position slightly above the main digging blade 11,
A large-diameter enlarged excavation blade 17 for enlarging a small-diameter excavation hole excavated by the main excavation blade 11 is provided. More specifically, a blade plate 19 inclined in the same direction as the inclined plate 9 is provided horizontally long slightly above the main excavating blade 11, and a plurality of excavations are provided near the tip of the blade plate 19. The teeth 21 are mounted. The height of the lower ends of the left and right sub-rotating shafts 7L and 7R is substantially equal to the height of the enlarged excavating blade 17, and the lower ends of the sub-rotating shafts 7L and 7R are Although the inclination direction is opposite to that of the inclined plate 9, the inclined plates 9L and 9R having the same configuration are attached. The small-diameter sub-drilling blades 11L, 1R are provided at the lower edges of the inclined plates 9L, 9R.
A plurality of digging blades 13L and 13R are mounted as 1R. Further, baffle plates 15L and 15R similar to the baffle plate 15 are attached to the lower end surfaces of the sub rotary shafts 7L and 7R. At the position slightly above the sub-drilling blades 11L and 11R, the inclined plates are used as enlarged drilling blades 17L and 17R for enlarging small-diameter holes drilled by the sub-drilling blades 11L and 11R. Blade plates 19L and 19R inclined in the same direction as 9L and 9R are provided to be long horizontally. Similar to the blade plate 19, the blade plates 19L and 19R excavate so as to enlarge the small-diameter excavation hole excavated by the sub-drilling blades 11L and 11R. Although one part overlaps, the parts are vertically shifted so as not to interfere with each other. The main rotation shaft 5 and the left and right sub rotation shafts 7L, 7
In order to always keep the distance between the main rotating shaft 5 and the main rotating shaft 5 and the left and right sub-rotating shafts 7L and 7R at equal heights, a bearing portion 25 provided with flanges 23 vertically separated from each other. Are formed, and the main rotary shaft 5 and the left and right sub rotary shafts 7 are formed.
Each of the bearing portions 25 formed on the L and 7R is rotatably supported by a horizontal separation holding member 27. Therefore, the main rotation shaft 5 and the left and right sub rotation shafts 7L and 7R are always kept at a fixed interval. In order to stir the excavated soil excavated by the main excavating blade 11 and the enlarged excavating blade 17, the main rotating shaft 5 is inclined in the same direction as the blade plate 19 and is substantially equal to the blade plate 19. A plurality of stirring blades 29 having a length are provided horizontally at appropriate intervals in the vertical direction. Similarly, the blade plates 19L, 1R are attached to the left and right auxiliary rotation shafts 7L, 7R.
A plurality of stirring blades 29L and 29R, which are inclined in the same direction as 9R and have substantially the same length, are provided horizontally at appropriate intervals in the vertical direction. When viewed in a plan view, the rotation trajectory of the stirring blade 29 provided on the main rotary shaft 5 and the left and right sub rotary shafts 7L, 7L
Although a part of the rotation trajectories of the stirring blades 29L and 29R provided on the R overlap, the positions are vertically shifted so as not to interfere with each other. In the above configuration, when the excavator 1 is positioned with respect to the soft ground to be improved, the main rotary shaft 5 is rotated forward, and the left and right auxiliary rotary shafts 7L and 7R are rotated and gradually lowered. First, a small-diameter hole is excavated prior to a small-diameter main excavation blade 11 provided at the lower end of the main rotary shaft 5. Thereafter, the small-diameter excavation hole excavated by the main excavation blade 11 is enlarged by the large-diameter enlarged excavation blade 17, and the small-diameter sub-excavation blade 11L provided at the lower end of the left and right sub-rotating shafts 7L, 7R. , 11R starts excavation of a small excavation hole. And after that, the sub-rotating shafts 7L, 7R
The large-diameter enlarged excavation blades 17L and 17R provided in the above-mentioned form cause the small-diameter excavation hole to be enlarged and excavated. Thereafter, when the excavation further proceeds, the excavated soil is divided into a plurality of agitating blades 29 provided on the main rotary shaft 5 and the sub rotary shaft 7.
The stirring is performed by a plurality of stirring blades 29L and 29R provided in L and 7R. Therefore, at the time of stirring the excavated soil, a soil hardening material such as cement is appropriately discharged from the slurry discharge ports provided at the lower ends of the main rotary shaft 5 and the sub rotary shafts 7L and 7R together with the excavated soil, as in the related art. Stir. Therefore, after the stirring is completed, the soil is improved by raising the excavator 1 and leaving it unattended. As will be understood, at the time of excavation, the small-diameter main excavating blade 11 provided at the lower end of the main rotary shaft 5 performs excavation first, and later, at the lower end of the left and right auxiliary rotary shafts 7L and 7R. Since the provided small-diameter sub-drilling blades 11L and 11R are for excavation, the main drilling blade 11 and the left and right sub-drilled blades 11L and 11R are excavated.
The relationship with 11R is a triangular positional relationship, which acts so that the loads on the left and right sub-digging blades 11L and 11R are equal, and improves the straightness in the vertical downward direction. At the time of the excavation operation, first, a small-diameter hole is excavated by the small-diameter main excavation blade 11 and the left and right small-diameter sub-excavation blades 11L, 11R, and then by the subsequent large-diameter enlarged excavation blades 17, 17L, 17R. Since the excavation is performed so as to enlarge the small-diameter excavation hole, the small-diameter excavation blades 11, 11L, 11R and the large-diameter enlarged excavation blades 17, 17L, 17R are formed despite excavating the large-diameter excavation hole. At the same time, the load at the time of excavation is divided into two, so that the load on each excavation blade can be reduced and the life of the excavation blade can be extended. Therefore, the enlarged excavating blades 17, 17L, 1
The diameter of 7R can be made larger, and a larger hole can be excavated than before. Further, since a small-diameter excavation hole precedes a large-diameter enlarged excavation blade, a small-diameter excavation hole is excavated. The property is improved. As will be understood from the above description, according to the present invention, it is possible to improve the straightness when excavating vertically and to excavate a large-diameter excavation hole. In this case, the load can be reduced by dividing the load into the small-diameter excavation blade and the large-diameter enlarged excavation blade, so that the load can be reduced and the life of the excavation blade can be prolonged.
Therefore, the conventional problem as described above can be solved.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an operation explanatory view showing an overall configuration of a ground improvement excavator according to an embodiment of the present invention. [Description of Signs] 1 ... ground improvement excavator 5 ... main rotary shaft 7L, 7R ... sub rotary shaft 11, 11L, 11R ... small-diameter cutting blade 17, 17L, 17R ... enlarged cutting blade 27 ... separation holding member 29, 29L, 29R: stirring blade

Claims (1)

Claims: 1. A hollow sub-rotating shaft, which is shorter than the main rotating shaft, is arranged and provided on both sides of a hollow main rotating shaft having a small-diameter main excavating blade at a lower end portion. The lower portions of the main rotary shaft and the sub rotary shafts are rotatably supported and provided by a separation holding member. A sub-enlarged excavating blade having a diameter is provided, and a large-diameter enlarged excavating blade is provided on the main rotating shaft at a height substantially equal to the sub-excavating blade, and the excavated soil excavated on the main rotating shaft and each sub-rotating shaft is stirred. And an agitating blade for rotating the main rotation shaft and the sub rotation shafts in opposite directions.