JP3960962B2 - Ground improvement device - Google Patents

Description

  The present invention relates to a ground improvement device for improving a soft ground or the like by stirring and mixing a solidified material such as cement milk and soil while excavating the ground.

Conventionally, as a ground improvement device, a plurality of fixed stirring blades are provided at predetermined intervals on an endless chain suspended between two sprockets, and these fixed stirring blades circulate in the ground together with the endless chain. In addition, a configuration is known in which a solidified material such as cement milk is supplied into the ground via a solidified material supply pipe so that the excavated soil and the solidified material are stirred and mixed (for example, Patent Document 1). 2).
Japanese Patent Laid-Open No. 10-204868 JP 2002-212941 A

The fixed stirring blade of the above-mentioned conventional ground improvement device has a flat plate portion to be attached to the endless chain, and a vertical plate portion formed integrally with the flat plate portion. By having these vertical plate portions and the like, the underground is excavated downward, and the excavated soil and the solidified material are mixed and stirred.
However, since the vertical plate part excavating the ground is integrally fixed to the flat plate part attached to the endless chain, the ground subject to ground improvement has a slightly higher adhesive strength. If the soil consists of soil or volcanic ash, such as clay soil (loam soil), the sticky soil will remain attached to the vertical plate, leading to a decline in excavation and agitation capabilities, Alternatively, there is a problem that a so-called co-rotation phenomenon occurs in which a large amount of soil adheres so as to wrap up the entire fixed stirring blade, and the endless chain is idle in the ground and cannot be stirred and mixed with the soil.
Therefore, the present invention provides a ground improvement device that can perform excavation and stirring mixing well even if the target of ground improvement is soil that is prone to co-rotation phenomena such as cohesive soil. The purpose is to do.

  As a result of intensive studies to solve the above-mentioned problems, the present inventor has a large adhesive force such as a viscous soil by using a rotatable blade having a rotatable shaft body to which a plurality of stirring rods extending radially are fixed. It has been found that excavation and agitation mixing can be performed satisfactorily without causing co-rotation or the like even in soil, and the present invention has been completed.

That is, the present invention provides the following [1] to [3].
[1] A ground improvement device for mounting to a lower end of a movable arm extending from a work vehicle (base machine), and a support body to be attached to the lower end of the movable arm, and an upper portion of the support body A driven sprocket, a driven sprocket disposed below the support, an endless chain hung between the driving sprocket and the driven sprocket, and a plurality provided on the outer peripheral surface of the endless chain A plurality of rotatable wings, the rotatable wings being attached to the endless chain, a shaft rotatably supported by the frame, and a plurality of radially extending members fixed to the shaft. The frame body has a pair of side plate portions, each of the pair of side plate portions is formed in a flat plate shape extending in parallel to the extending direction of the endless chain, and Shaft Through and soil improvement apparatus characterized by having a through hole for supporting.
[2] Three to nine pairs of the stirring rods are provided at equal intervals in the axial direction of the shaft body, with two pairs extending from the shaft body extending in opposite directions. However, the ground improvement device according to [1], wherein the ground improvement device is provided so as to be sequentially shifted from the axis of the shaft by a predetermined angle.
[3] The ground improvement device according to [1] or [2], wherein the stirring bar is provided so as to extend in a direction perpendicular to a direction in which the shaft body extends.

  According to the ground improvement device of the present invention, a plurality of radially extending stirring rods fixed to a rotatable shaft body stir the soil by rotation of the shaft body separately from the movement accompanying the rotation of the endless chain. Therefore, even if the target of ground improvement is viscous soil, etc., a phenomenon in which a large amount of soil adheres to the entire rotatable wing and hardly rotates, and excavation and stirring mixing can be performed in a good state. .

Hereinafter, embodiments of the ground improvement device of the present invention will be described with reference to the drawings.
FIG. 1 is an overall view showing an example of a work vehicle equipped with the ground improvement device of the present invention, FIG. 2 is a front view showing the internal structure of the ground improvement device of the present invention, and FIG. 3 is a ground improvement device of the present invention. FIG. 4 is a diagram for explaining the arrangement of the stirring rod of the rotatable wing shown in FIG. 3, and FIG. 5 is a diagram of the rotatable wing shown in FIG. It is a left side view.

As shown in FIG. 1, the ground improvement device 1 of the present invention is attached to the lower end of a movable arm 3 extending from a work vehicle 2, and is submerged as the movable arm 3 moves up and down. The ground 5 made of soft soil or the like is excavated, and the soil and a solidified material to be described later are agitated and mixed to form improved soil 6 suitable for a building foundation or the like.
The work vehicle 2 is guided with a solidification material supply pipe 4 for supplying a solidified material such as slurry or powdered cement from the storage tank to the excavation site. The solidification material supply pipe 4 reaches the vicinity of the driven sprocket 12 of the ground improvement device 1 through the movable arm 3 from the work vehicle 2 and discharges the solidification material into the ground.

As shown in FIG. 2, the ground improvement device 1 includes a support 10 that is attached to the lower end of the movable arm 3, a drive sprocket 11 and a driven sprocket 12 that are supported by the support 10, and a space between these sprockets 11 and 12. And an endless chain 13 and the like that are hung on.
The support 10 is a fixed part that does not move relative to the movable arm 3. The support 10 is formed below the connecting part with the movable arm 3 and extends substantially horizontally, and the front and rear of the ceiling wall 19. A pair of side walls 20 that hang down from the edges, a connecting portion 21 that is fixed between the pair of side walls 20 at a lower portion of the side wall 20, and a tension ring 23 that is attached to the connecting portion 21. Yes. Here, the tension wheel 23 is a guide means for slightly extending the endless chain 13 to the side to maintain a predetermined tension.

The drive sprocket 11 is disposed between the pair of side walls 20 and slightly above the connecting portion 21 and is rotated by a drive shaft 18 using a motor (not shown) as a drive source. The drive shaft 18 is supported by a bearing (not shown) provided in the connecting portion 21.
The driven sprocket 12 is rotatably supported at the lower portion of the connecting portion 21. Note that the shaft of the driven sprocket 12 is supported by a bearing (not shown) provided in the connecting portion 21.
When the drive shaft 18 is driven to rotate the drive sprocket 11, the endless chain 13 circulates between the drive sprocket 11 and the driven sprocket 12 while being guided by the tension wheel 23.

Rotation that is fixed on the outer peripheral surface of the endless chain 13 at a predetermined interval in a state where the movable arm 3 descends in the ground at a predetermined excavation speed and the endless chain 13 circulates at a predetermined rotation speed. The universal wing 14 is discharged downward from the excavated soil and the solidified material discharge part 25 in the process of newly excavating the ground when passing through the lower end of the endless chain 13 and circling with the endless chain 13. The improved soil 6 is obtained by stirring and mixing with a solidified material such as cement milk.
In the vicinity of the driven sprocket 12, an air injection unit 22 that is an end of an air supply pipe for supplying compressed air is provided. The air injection unit 22 injects compressed air toward the vicinity of the lower end of the driven sprocket 12. The compressed air injection region is, for example, a range indicated by reference numeral 24 in FIG. The compressed air prevents the soil from adhering to the rotatable wing 14 (the direction of travel is indicated by an arrow A in FIG. 2) that passes near the lower end of the driven sprocket 12, and the rotation of the rotatable wing 14 in the soil. It has the effect | action which reduces the resistance with respect to rotation of the shaft body 16 and the stirring rod 17 (refer FIG. 3).
As shown in FIGS. 3 to 5, the rotatable blade 14 includes a frame body 15, a shaft body 16 that is rotatably supported by the frame body 15, and a stirring rod 17 fixed to the shaft body 16.

As shown in FIG. 3, the frame body 15 is a member having a substantially U-shaped cross section. The frame body 15 has a flat bottom plate portion 15 a fixed to the endless chain 13 and both edges of the bottom plate portion 15 a. It is formed from a pair of side plate portions 15b that are bent upward substantially vertically. Each of the pair of side plate portions 15b is provided with a through hole for inserting and supporting the shaft body 16.
As shown in FIG. 5, each of the pair of side plate portions 15b is formed in a flat plate shape extending in parallel to the extending direction of the endless chain 13 (the arrow in the figure indicates the traveling direction of the endless chain). Yes. A plate-like member such as the side plate portion 15b is not formed on the front and rear sides of the frame body 15 in the extending direction of the endless chain 13. Therefore, from the shaft body 16 supported by the frame body 15 and the stirring rod 17 The resulting rotating body can be in direct contact with the soil for excavation and mixing.

The shaft body 16 is rotatably supported by the side plate portion 15 b of the frame body 15. As the shaft body 16, for example, a steel round bar having an appropriate diameter cut into a predetermined length can be used. An annular rib 26 for positioning with respect to the frame body 15 is fixed to the shaft body 16.
The stirring rod 17 is a rod-like body or plate-like body having a smaller diameter than the shaft body 16, and is, for example, a steel round bar having a suitable diameter, a square bar or the like cut into a predetermined length, or made of steel. What cut | disconnected the flat plate of this to the predetermined shape can be used.
Examples of the method for attaching the stirring rod 17 include a method in which a hole matching the diameter of the stirring rod 17 is provided in the shaft body 16 and then the stirring rod 17 is inserted into this hole and fixed by welding or the like. At this time, if the stirring rod 17 is detachably attached to the shaft body 16, it is advantageous because only the stirring rod 17 can be easily replaced when the stirring rod 17 is broken.

The stirring rod 17 may be provided so as to extend in a direction perpendicular to the extending direction of the shaft body 16 (FIGS. 3 to 5), or at a predetermined angle with respect to a plane perpendicular to the axis of the shaft body 16. It may be provided and attached obliquely.
In the example shown in FIGS. 3 to 5, the stirring rod 17 is positioned inside the stirring rods a, c, d, and b (two each) located outside the frame 15 and the side plate portion 15 b of the frame 15. Stirring rods f and e (two each).
The two stirring bars 17 extending in opposite directions from the shaft body 16 are paired (for example, b and b in FIG. 5), and these pairs are denoted by b, d, f, e, c, and FIG. As shown as a, it is configured by providing six (12 stirring rods) at equal intervals in the axial direction of the shaft body 16.

Here, as shown in FIGS. 3 and 4, the stirring rods a to f are provided so as to be sequentially shifted from the axis of the shaft body 16 by a predetermined angle (30 degrees) sequentially. That is, FIG. 4 shows the arrangement of the six pairs (af) constituting the stirring rod 17 shown in FIG. 3 as viewed from the left side of FIG. As shown, the stirring rods b and b, the stirring rods c and c, the stirring rods d and d, the stirring rods e and e, and the stirring rods f and f are each 30 degrees in the direction opposite to the rotation direction of the clock hands. Indicates that they are shifted. FIG. 5 is a view of the rotatable blade 14 shown in FIG. 3 as viewed from the left (however, the stirring rod 17 shows only b and d). 4 and 5, reference numeral 27 indicates a rotation locus of the end portion of the stirring rod 17.
The number of the stirring rods 17 is not particularly limited and is not particularly limited to 12 as the stirring rods a to f in FIG. 3, but if the amount is too small, the stirring force becomes insufficient, and if too large, the number of the stirring rods Since the gap becomes narrow and the soil easily adheres, the number is preferably 6 to 18, particularly preferably 8 to 16.

  Only one endless chain 13 having a plurality of rotatable blades 14 may be mounted between the pair of side walls 20, or two or more endless chains 13 may be mounted. When two or more are mounted, the same number of drive sprockets 11, driven sprockets 12, connecting portions 21, etc. as the endless chain 13 may be provided between the pair of side walls 20.

1 is an overall view showing an example of a work vehicle equipped with a ground improvement device of the present invention. It is a front view which shows the internal structure of the ground improvement apparatus of this invention. It is a front view which shows the structure of the rotatable wing | blade which is a component of the ground improvement apparatus of this invention. It is a figure for demonstrating arrangement | positioning of the stirring rod of the rotatable blade shown in FIG. FIG. 4 is a left side view of the rotatable wing shown in FIG. 3.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Ground improvement apparatus 2 Work vehicle 3 Movable arm 4 Solidification material supply pipe 5 Ground 6 Improvement soil 10 Support body 11 Drive sprocket 12 Driven sprocket 13 Endless chain 14 Rotating vane 15 Frame 15a Bottom plate part 15b Side plate part 16 Shaft body 17 Stirring Rod 18 Drive shaft 19 Ceiling wall 20 Side wall 21 Connecting portion 22 Air injection portion 23 Tension wheel 24 Compressed air injection region 25 Solidified material discharge portion 26 Annular rib 27 Rotating locus of the tip of the stirring rod

Claims (3)

A ground improvement device for mounting to a lower end of a movable arm extending from a work vehicle,
A support for attaching to the lower end of the movable arm, a drive sprocket disposed at the upper part of the support, a driven sprocket disposed at the lower part of the support, and a space between the drive sprocket and the driven sprocket. And an endless chain that is hung on the outer peripheral surface of the endless chain, and a plurality of rotatable wings provided on the outer peripheral surface of the endless chain,
The rotatable wing comprises a frame for attaching to the endless chain, a shaft rotatably supported by the frame, and a plurality of radially extending stirring rods fixed to the shaft .
The frame includes a pair of side plate portions;
Each of the pair of side plate portions is formed in a flat plate shape extending in parallel to the extending direction of the endless chain, and has a through hole for inserting and supporting the shaft body. apparatus. The stirring rods are provided in pairs of two extending in the opposite directions from the shaft body, and 3 to 9 pairs are provided at equal intervals in the axial direction of the shaft body. The ground improvement device according to claim 1, wherein the ground improvement device is provided so as to be sequentially shifted by a predetermined angle radially from the axis of the shaft body. The ground improvement device according to claim 1 or 2, wherein the stirring bar is provided so as to extend in a direction perpendicular to a direction in which the shaft body extends.

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