JPH1161800A - Preventive device against rotating together for stabilizing method of ground - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent decrease of excavating efficeincy while slanting preventive blades against rotating together with solid during excavating operation of a hard ground, by fitting the preventive blades to be rotatable and vertically movable against the excavation rod and horizontally turning it by an urging means. SOLUTION: Ground is excavated by an excavating blade 5 of an excavation rod 1 and excavated soil and a solidifying agent are agitated and mixed together by agitation blades 7 to form a solidified body. A boss 2 is rotatably fitted to the excavation rod 1 and a horizontal shaft 62 is provided in a bracket 6 fixed to the boss 2 so as to freely incline preventive blades 3 against rotating together with soil, which are longer than the rotary radius of the excavating blade 5 and horizontally returnable with an urging means such as a coil spring, flat spring. Accordingly, when excavating a hard ground, the preventive blades are inclined to contract the distance between the front ends and prevent decrease of the excavating efficiency and when forming a solidified body, the preventive blades 3 are horizontally turned by the urging member and fixed to the wall of the excavation hole. In this way, excavated soil is prevented from sticking to the agitation blades 7 and rotating together with the blades 7 and a homogeneously solidified body can be constructed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a co-rotation prevention device which is used in a ground improvement method for stirring and mixing excavated soil and a solidified material, and which is mounted on the outer periphery of a drilling rod.

[0002]

2. Description of the Related Art In a ground improvement method for constructing a consolidated body by stirring and mixing excavated soil excavated by an excavation wing at the tip of an excavation rod and a solidified material supplied into the excavated soil, a solidified body is constructed. The excavated soil adheres around the stirring blade at the time of stirring and mixing by the stirring blade protruding from the outer periphery of the drilling rod, and there is a possibility that the earth mass is generated by rotating with the stirring blade.
If the earth mass is generated, the completed compact becomes inhomogeneous in the axial direction, which causes a decrease in the compressive strength of the compact.

[0003] In order to solve this problem, the applicant attaches a co-rotation prevention wing longer than the digging diameter to the outer periphery of the digging rod while being insulated from the rotation of the digging rod. A device to prevent rotation has been proposed (Japanese Patent Publication No. 58-29374).

[0004] When the tip of the co-rotation prevention wing is inserted into the ground around the excavation ground, the wing remains in a stationary state even when the excavation rod rotates, but is dropped into the ground with the excavation of the excavation rod. If there is a hard ground around the excavated ground, the resistance will reduce the construction efficiency,
Or they face problems such as being unable to excavate.

The present invention proposes a co-rotation prevention device that solves the above-mentioned problem.

[0006]

According to the present invention, a co-rotation prevention wing is rotatably connected to a boss rotatably mounted on the drill rod on the outer circumference of the drill rod around a horizontal axis. By installing an urging member between the anti-rotation wings to urge the anti-rotation wings to return to the original position when the anti-rotation wings are inclined with respect to the boss, construction efficiency due to the presence of hard ground To prevent the situation where the digging is impossible.

The anti-corotating wings protrude from the outer periphery of the boss,
The distance from the axis of the drill rod to the tip is greater than the radius of gyration of the drill wing at the tip of the drill rod.

[0008] The tip of the co-rotation prevention wing is dropped into the ground around the excavation ground from the start of the descent of the excavation rod, and at the time of contact with the hard ground, it is inclined with respect to the boss to avoid collision, thereby excavating. Continue excavating the rod. Once over the hard ground, the anti-corotating wing is returned to its original position by the biasing member, and the tip is kept inserted in the ground around the excavated ground.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG.
And a boss 2 rotatably mounted on the excavating rod 1 as shown in FIG. 1 and a co-rotating boss 2 projecting from the outer periphery of the boss 2 and rotatably connected to the boss 2 around a horizontal axis 62. The anti-rotation wing 3 is provided between the boss 2 and the anti-rotation wing 3, and the biasing member 4 is configured to return the anti-rotation wing 2 to the original position when the anti-rotation wing 3 is inclined with respect to the boss 2. Is done. In FIG. 1, reference numeral 7 denotes a stirring blade.

In a state where the anti-corotating wing 3 is not inclined with respect to the boss 2, that is, in a horizontal state indicated by a solid line in FIG. 1, the distance from the axis of the excavating rod 1 to the tip of the anti-corotating wing 3 is reduced. It is larger than the radius of gyration of the excavating wing 5 connected to or protruding from the tip of the excavator.

The anti-corotation wing 3 is supported by brackets 6 and 6 projecting in parallel from the outer periphery of the boss 2 by a horizontal shaft 62. The angle of inclination with respect to the bracket 6 is, for example, as shown in FIGS. The pins 31, 31 projecting from both sides in the width direction of the co-rotation prevention blade 3 are restricted by moving in the arc-shaped guide grooves 61, 61 formed in the brackets 6, 6.

The deflection of the anti-corotating wing 3 in the width direction with respect to the bracket 6 is achieved by interposing a spacer 32 for keeping a space between the both sides of the anti-corotating wing 3 in the width direction or the bracket 6. Is prevented by In FIG. 3, a spacer 32 having the same axis as the pin 31 is formed in a portion of the pin 31 of the co-rotation prevention blade 3 located between the co-rotation prevention blade 3 and the bracket 6.

FIG. 2 shows a case where the tip of the co-rotation prevention blade 3 is formed by cutting off a part of a circle. In the case of the illustrated form, the inclination angle from the horizontal state of the co-rotation prevention wing 3 to the contact of the tip with the hole wall, while the total length of the co-rotation prevention wing 3 is the same as the case of the arc shape shown by the broken line. Can be made smaller than in the case of an arc shape.

FIG. 3 shows an example in which the biasing member 4 is a coil spring disposed around a horizontal shaft 62 that supports the co-rotation prevention blade 3. One end of the urging member 4 is engaged with the co-rotation prevention wing 3, and the other end is engaged with the bracket 6. FIG. 4 shows a case in which the axis of the coil spring is arranged in the direction of the tangent of an arc centered on the horizontal axis 62, and both ends are engaged with the co-rotation prevention blade 3 and the bracket 6.

FIGS. 5 and 6 show an example in which the urging member 4 is a leaf spring. Here, the urging member 4 is connected to the co-rotation preventing wing 3.
Are fixed to the brackets 6 and 6 in a state of contacting the upper end surface and the lower end surface when they are horizontal. When using a leaf spring,
A portion of the horizontal shaft 62 between the anti-corotating wing 3 and the brackets 6, 6 may be formed in a rectangular shape, and leaf springs may be brought into contact with upper and lower surfaces thereof.

In any case, the urging member 4 is used when the co-rotation prevention wing 3 is lowered as shown by a chain line in FIG.
Alternatively, when it comes into contact with the hard ground when ascending and inclines with respect to the boss 2, the horizontal state shown by the solid line is restored.

[0017]

According to the present invention, a co-rotation prevention wing is rotatably connected to a boss rotatably mounted on the digging rod on the outer periphery of the digging rod, and is rotatably connected around a horizontal axis. In order to install an urging member to return the anti-rotation wing to its original position when the rotation prevention wing is inclined with respect to the boss,
It is possible to prevent a reduction in construction efficiency due to the presence of the hard ground and a situation in which excavation becomes impossible.

[Brief description of the drawings]

FIG. 1 is an elevation view showing the relationship between a drilling rod and a co-rotation prevention device.

FIG. 2 is a longitudinal sectional view showing a case where the tip of the co-rotation prevention wing is formed in a polygonal shape.

FIG. 3 is a cross-sectional view of FIG. 1 when the biasing member is a coil spring.

FIG. 4 is a longitudinal sectional view showing a case where another coil spring is used.

FIG. 5 is a partial cross-sectional view of FIG. 1 showing a case where the urging member is a leaf spring.

FIG. 6 is a longitudinal sectional view of FIG.

[Explanation of symbols]

1 ... drilling rod, 2 ... boss, 3 ... anti-rotation wing,
31 ... pin, 32 ... spacer, 4 ... biasing member, 5 ...
Drilling wings, 6 brackets, 61 guide grooves, 62 horizontal shafts, 7 stirring blades.

Claims (1)

[Claims] 1. A stirrer is mounted on the outer periphery of a protruding drilling rod in a state insulated from rotation of the drilling rod,
A device for preventing the excavated soil excavated by the excavation blade at the tip of the excavation rod from rotating together with the agitating blade. A boss rotatably mounted on the outer periphery of the excavation rod with respect to the excavation rod, and an outer periphery of the boss. Between the boss and the boss and the boss and the co-rotation prevention wing, wherein the distance from the axis of the excavation rod to the tip is larger than the radius of rotation of the digging wing, And a biasing member for biasing the co-rotation prevention wing in a direction to return to the original position when the co-rotation prevention wing is inclined with respect to the boss.