JP3140402B2 - Co-rotation prevention device for ground improvement method - Google Patents

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 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 solidified material supplied into the excavated soil is known. 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 response to this problem, the applicant mounts a co-rotation prevention wing longer than the digging diameter on the outer periphery of the digging rod in a state insulated from the rotation of the digging rod, so that the excavated soil adheres to the stirring blade. 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 excavated ground, the wing remains stationary even when the excavated rod rotates. 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 bracket that protrudes from the anti-rotation wing and the anti-rotation wing, the biasing member that returns the anti-rotation wing to its original position when the anti-rotation wing is tilted with respect to the boss, the presence of hard ground To prevent the construction efficiency from lowering and the situation where excavation becomes impossible.

The distance from the axis of the excavation rod to the tip of the co-rotational wing is greater than the radius of rotation of the digging wing, and the co-rotational wing protrudes from the outer periphery of the boss and is supported by the bracket by a horizontal shaft. On the other hand, it is connected to the boss so as to be rotatable about a horizontal axis. The urging member urges the co-rotation prevention wing in a direction to return to a horizontal original position when the co-rotation prevention wing is inclined with respect to the boss.

The tip of the corotation prevention wing is dropped into the ground around the excavation ground from the start of the descent of the excavation rod, and when contacting with the hard ground, it is inclined with respect to the bracket to avoid collision, and 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 bracket is protruded from the outer periphery of the digging rod on the outer periphery of a boss rotatably mounted on the digging rod. A biasing member is installed between the bracket and the anti-rotation wing, which is rotatable about the horizontal axis, and returns the anti-rotation wing to its original position when the anti-rotation wing is inclined with respect to the boss. When the excavating rod descends or rises, the inclined counter-rotating wings that come into contact with the hard ground can be restored to a horizontal state, which reduces the efficiency of construction due to the presence of the hard ground and makes excavation impossible. Can be prevented.

According to the third aspect of the present invention, the anti-corotating wing is pivotally supported on the bracket between the brackets projecting in parallel with the outer periphery of the boss, so that pins protruding from both sides in the width direction of the anti-corotating wing are formed on the bracket. It is possible to move inside the arcuate guide groove thus formed, thereby limiting the inclination angle of the anti-corotating wing with respect to the bracket.

According to the fourth aspect of the present invention, since a spacer for maintaining a space between the both sides of the anti-corotating blade in the width direction and the bracket is interposed therebetween, it is possible to prevent the anti-corotating blade from swinging in the width direction with respect to the bracket. .

According to a fifth aspect of the present invention, the tip of the co-rotation prevention wing is formed by cutting off a part of an arc. The inclination angle from the horizontal state to the contact of the tip with the hole wall can be made smaller than in the case of a circular arc.

[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 (5)

(57) [Claims] 1. A boss rotatably mounted on an excavating rod on an outer periphery of an excavating rod on which a stirring blade is protruded,
A bracket protruding from the outer periphery of the boss and extending from the outer periphery of the boss, supported by the bracket by a horizontal shaft, connected to the boss so as to be rotatable around the horizontal axis with respect to the boss, and extending from the shaft of the excavation rod to the tip. A counter-rotating wing having a length greater than the radius of gyration of the excavating wing, and a counter-rotating wing disposed between the bracket and the co-rotating wing; And a biasing member for returning to an original position in a proper state, and a co-rotation prevention device for a ground improvement method for preventing excavated soil excavated by an excavation blade at the tip of an excavation rod from rotating together with the stirring blade. 2. The co-rotation prevention device for a ground improvement method according to claim 1, wherein the biasing member is a coil spring or a leaf spring. 3. The ground improvement method according to claim 1, wherein the bracket is projected in parallel with the outer periphery of the boss, and the anti-corotating wing is pivotally supported by the bracket between the parallel brackets. Co-rotation prevention device. 4. The co-rotation prevention device for a ground improvement method according to claim 3, wherein a spacer for maintaining a space between the both sides in the width direction of the co-rotation prevention wing and the bracket is interposed therebetween. 5. The co-rotation prevention device for a ground improvement method according to claim 1, wherein the tip of the co-rotation prevention blade has a shape in which a part of an arc is cut off.