JP2017020179A - Drilling and agitation device with corotation prevention blade - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a drilling and agitation device with a corotation prevention blade, capable of preventing an adverse effect caused by a foreign material if any.SOLUTION: This device comprises: a revolving shaft 2 which rotates underground; drilling blades 3 which protrude from a lower end of the revolving shaft 2 and drill sediment; a boss part 10a which revolves around the revolving shaft 2 and is loosely fit to the revolving shaft 2 above the drilling blades 3; a corotation prevention blade 10 whose base end part is fixed to the boss part 10a and whose tip is positioned outside of the drilling blades 3 and contacts natural ground; and a discharge guide blade 11 which is integrated with the corotation prevention blade 10, is disposed between the corotation prevention blade 10 and the drilling blade 3, and has a guide lateral surface 11a which intersects with the corotation prevention blade 10 in plan view and guides a foreign material from the revolving shaft 2 side to the natural ground side.SELECTED DRAWING: Figure 2

Description

  The present invention relates to an excavation and agitation apparatus with a co-rotation prevention blade that is used in a ground improvement method such as a deep mixing treatment method, and prevents the excavation soil from rotating together with the excavation blade and the agitation blade.

  If the soil is highly viscous (for example, clay, silt, etc.), the excavated earth and sand and the solidified milk will try to rotate together with the rotation of the drilling blade. As a result, a non-homogeneous column will be created and a co-rotation prevention wing will be required.

  Specifically, as disclosed in Patent Document 1 (Japanese Patent No. 1197295), in an auger-type drilling device in which a drilling blade is provided at the lower end of a rotating shaft, a drilling diameter that is a rotating outer diameter of the drilling blade. It is more desirable to loosely fit the large-diameter co-rotation preventing wing to the rotating shaft.

  In this way, while the rotating shaft is actively rotated by the driving means in the ground, since the tip of the co-rotation preventing wing touches the surrounding ground, the co-rotation preventing wing hardly rotates in the ground. . In other words, a large angular velocity difference is generated between the rotating shaft and the co-rotation preventing blade, and this angular velocity difference causes the soil on the upper side and lower side (excavation blade side) to be bordered with the co-rotation preventing blade as a boundary. It will be.

  In this specification, when the region where the excavating action of the excavating blade reaches is referred to as “operation volume”, the co-rotation preventing wing is located at the boundary portion of the operation volume, and when viewed from the soil to be co-rotated, It works like a baffle that prevents co-rotation. By such a function, the operation volume is limited to a certain range, and as a result, the kneading by the excavating blade is good.

  Recently, there are increasing examples of ground improvement at the time of rebuilding a building, and ground such as buried soil and embankment is often targeted for improvement. In such ground, not only soil, but often foreign matters (for example, concrete galley, asphalt galley, crushed rocks, boulders, cobblestones, gravels, wood chips, etc., usually about 10 centimeters to 50 centimeters in diameter) Stuff).

If foreign matter is contained in the ground, the foreign matter may be caught between the excavation blade and the co-rotation prevention blade, and these blades may be deformed or damaged. Furthermore, if the foreign object remains sandwiched between the excavating blade and the co-rotation preventing blade, the blades that should generate the angular velocity difference are rotated by the foreign object and connected together. The edge-cutting action of the anti-rotation wing will not be fulfilled. If it becomes like this, the quality of the ground improvement body will fall remarkably. Originally, foreign matter is often stronger than soil cement, so even if the foreign matter remains in the ground improvement body, the quality of the ground improvement body is not impaired, but the edge cutting action of the co-rotation prevention wing is invalid Must not be
Japanese Patent No. 1197295 JP 2010-180647 A JP 2005-325548 A JP 2001-40651 A

  Then, an object of this invention is to provide the excavation stirring apparatus with a co-rotation prevention wing | blade which can suppress the bad influence even if a foreign material exists.

  According to a first aspect of the present invention, there is provided an excavating and agitating device with a co-rotation preventing blade, a rotating shaft that rotates in the ground, a drilling blade that protrudes from a lower end portion of the rotating shaft, excavates earth and sand, and rotates above the drilling blade. A boss part that circulates around the shaft and is loosely fitted to the rotating shaft, and a co-rotation prevention blade that has a proximal end fixed to the boss part and whose tip is located outside the excavation blade and is in contact with the natural ground. Integrated with the anti-rotation blade, interposed between the co-rotation prevention blade and the excavation blade, and intersects the co-rotation prevention blade in plan view, and has a guide side surface for guiding foreign matter from the rotating shaft side to the natural ground side. And a discharge guide vane.

  Preferably, the guide side surface of the discharge guide vane is formed so that the distal end portion of the discharge guide vane is away from the excavating vane as compared to the base end portion close to the boss portion in plan view. Preferably, the guide side surface of the discharge guide vane is formed with a smooth curve in a plan view, or the guide side surface of the discharge guide vane is formed with a plurality of straight lines bent in a step shape in the plan view. .

  In this configuration, first, since the discharge guide vane is interposed between the co-rotation prevention blade and the excavation blade, the co-rotation prevention blade and the excavation blade are separated by at least the thickness of the discharge guide vane. This alone prevents foreign matter from getting caught between the co-rotation prevention blade and the excavation blade. Secondly, since the discharge guide vane has a guide side surface for guiding foreign matter from the rotating shaft side to the natural ground side, even if foreign matter is present near the co-rotation prevention blade and the excavation blade, the foreign matter is discharged to the discharge guide blade. Since the foreign material is guided to the natural ground side by the guide side surface, the foreign matter is more unlikely to be caught between the excavation blade and the co-rotation prevention blade. Therefore, the situation where the co-rotation preventing blade and the excavation blade rotate together is avoided, and the edge cutting effect by the co-rotation preventing blade is maintained.

  In addition, since the discharge guide vanes are integrated with the co-rotation preventing vanes, not only the co-rotation preventing blades but also the discharge guide vanes provide an edge cutting effect. For this reason, even if the co-rotation prevention blade and the excavation blade are separated, the operation volume of the excavation blade can be reduced as much as possible, and a high-quality ground improvement body can be formed.

  According to the present invention, foreign matter can be guided to the outer peripheral side of the column by the guide side surface of the discharge guide blade, and the foreign matter can be prevented from being caught between the excavation blade and the co-rotation prevention blade, and the discharge guide blade. Since the edge cutting effect is also exerted, the operation volume of the excavating blade can be reduced and a good ground improvement body can be formed.

(Comparative example)
Prior to the description of the embodiment of the present invention, adverse effects due to foreign substances in the comparative example will be described with reference to FIGS. Here, FIG. 9 is a side view of the excavating and stirring apparatus in the comparative example, and FIG. 10 is a cross-sectional view taken along the line AA of FIG.

  In FIG. 9, the rotation shaft 2 has a center line 1, and a rotation force by a driving means (not shown) is applied to the center line 1 in the direction of the arrow N or in the opposite direction to rotate forward or reverse. Note that the forward / reverse rotation is switched in consideration of the operation of descending or ascending by the driving means. Although the position of the center line 1 may slightly fluctuate due to soil resistance or vibration in the ground, the following description will be made on the assumption that the position of the center line 1 is fixed.

  Since the center line 1 is fixed, the tip edge of the excavation blade 3 provided at the lower end of the rotary shaft 2 describes a circular orbit (this is the column outer periphery 9) centered on the center line 1. More specifically, a plurality of claws 3a are provided on the lower side of the excavation blade 3, and excavation proceeds by rotating the claws 3a while biting into the soil.

  The co-rotation prevention blade 7 is provided above the excavation blade 3 by a predetermined distance on the rotary shaft 2. Specifically, the central portion (base end portion) of the co-rotation preventing wing 7 is a boss portion 7a that circulates around the rotation shaft 2 and is loosely fitted to the rotation shaft. The upper stopper 5 and the lower stopper 6 provided on the flange in the outer diameter direction from the rotary shaft 2 are positioned.

  A base end portion of the stirring blade 4 that is orthogonal to the excavation blade 3 (however, it is not essential and is optional) is further fixed above the upper stopper 5.

  As described above, when the rotating shaft 2 rotates, the stirring blade 4 and the excavation blade 3 rotate integrally therewith, but the co-rotation preventing blade 7 is almost stationary and a large angular velocity difference is generated. Due to this angular velocity difference, the edge cutting action described above is achieved.

  The operation volume described above is obtained by multiplying the area within the column outer periphery 9 by the sum of the distance t1 between the co-rotation prevention blade 7 and the excavation blade 3 and the height of the excavation blade 3. Since this area is fixed by the diameter of the excavating blade 3, it may be considered constant. Therefore, in order to reduce the operation volume and increase the effect of kneading, the interval t1 must be set small.

  The co-rotation prevention wing 7 of the comparative example is formed in a straight line in substantially the same manner as the excavation wing 3 in plan view. When the excavation blade 3 rotates with respect to the stationary anti-rotation blade 7, the anti-rotation blade 7 and the excavation blade 3 form a small corner, and cut the soil at the interval t <b> 1 like scissors. It moves like this.

  Here, when the foreign object 8 having a height exceeding the interval t1 approaches between the co-rotation prevention blade 7 and the excavation blade 3, the foreign material 8 is interposed between the blades 7 and 3 as shown in FIG. It gets caught.

  Fortunately, the foreign object 8 only needs to be cut, but normally, the foreign object 8 plays a role as a connecting tool for connecting the excavation blade 3 and the co-rotation prevention blade 7, and as a result, the co-rotation prevention blade 7. Is forcibly rotated by the excavating blade 3. In this case, the edge cutting action is hardly achieved, and the quality of the ground improvement body is significantly deteriorated.

(Embodiment 1)
Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a side view of an excavating and agitating apparatus according to an embodiment of the present invention, and FIG. 2 is a cross-sectional view taken along line BB in FIG.

  1 and 2, elements similar to those in FIGS. 9 and 10 showing the comparative example are denoted by the same reference numerals, and redundant description is omitted. In FIGS. 1 and 2, each pair of the co-rotation preventing blade 10 and the excavation blade 3 or the co-rotation preventing blade 10 and the stirring blade 4 is illustrated in only one stage. In addition, the present invention can be similarly applied, and such a case is also included in the protection scope of the present invention.

  In this embodiment, the height of the boss portion 10a is increased, the base end portion of the co-rotation preventing blade 10 is fixed to the upper side of the boss portion 10a, and the base end portion of the discharge guide blade 11 is fixed to the lower side of the boss portion 10a. doing. In other words, the interval t3 between the co-rotation prevention blade 10 and the excavation blade 3 is made larger than the interval t1 of the comparative example, and the discharge guide vane 11 is interposed between the common rotation prevention blade 10 and the excavation blade 3. Yes. In addition, the discharge guide vane 11 has a guide side surface 11 a having a shape in which the distal end portion moves away from the excavation blade 3 as compared with the base end portion close to the boss portion 10 a. Further, since the co-rotation preventing blade 10 and the discharge guide blade 11 are integrated, an edge cutting effect by the discharge guide blade 11 is also exhibited. As a result, the operation volume of the excavating blade 3 is obtained by multiplying the area of the horizontal section of the column by the sum of the interval t2 in FIG. 1 and the height of the excavating blade 3, and the operating volume can be made as small as possible.

  Due to such a relationship, the foreign matter 8 is not sandwiched between the co-rotation preventing blade 10 and the excavation blade 3, but is guided to the guide side surface 11a and pushed out to the outer peripheral side of the column. For this reason, according to the present invention, it is possible to employ an interval t2 that is smaller than the interval t1 of the comparative example, and as a result, it is possible to construct a high-quality ground improvement body by setting the operation volume smaller, 8 can be prevented from being sandwiched between the excavation blade 3 and the co-rotation prevention blade 10. Thus, when the interval is shortened, the quality of the ground improvement body can be improved, while the problem of a trade-off relationship that the risk of foreign matter pinching increases can be solved at a stretch.

  Although two discharge guide vanes 11 are paired in FIG. 2, they may be one or three or more. The co-rotation preventing blade 10 and the discharge guide vane 11 need only be integrated, and only one of the co-rotation preventing blade 10 and the discharge guide vane 11 is fixed to the boss portion 10a, and the other is not fixed. May be. A gap may be formed between the co-rotation preventing blade 10 and the discharge guide blade 11 in the vertical direction.

  Furthermore, as illustrated in FIGS. 3 to 8, the shape of the guide side surface 11 a of the discharge guide vane 11 in plan view can be variously changed. For example, as shown in FIG. 3, the base end portion may start so as to be in contact with the boss portion 10 a and may have a curved shape that curves smoothly with a certain curvature.

  Alternatively, as shown in FIG. 4, the curvature may be larger than that in FIG. 3 so that the tip portion faces inward.

  Or as shown in FIG. 5, you may comprise by the some straight line group bent in step shape.

  Alternatively, as shown in FIG. 6, the base end portion may be bent perpendicularly to the rotation shaft 2 and the tip end portion may be bent away from the excavation blade 3.

  Alternatively, as shown in FIG. 7, the base end side may be slightly inflated to the upper side of FIG.

  Furthermore, as shown in FIG. 8, the base end portion may be orthogonal to the boss portion 10a, then bent to the right in FIG. 8, and the curved portion may be continued to reach the distal end portion.

  Each of the various shapes in FIGS. 3 to 8 has advantages and disadvantages. However, any shape can be used to achieve certain effects. Therefore, these shapes are naturally included in the present invention. Unless the meaning of the above is changed, shapes not shown in the drawings also belong to the protection scope of the present invention.

  The excavation and stirring device with a co-rotation preventing blade according to the present invention can be suitably used in, for example, the field of ground improvement.

The side view of the excavation stirring apparatus in one embodiment of this invention BB sectional view of FIG. Sectional drawing which shows the shape of the discharge guide blade in the 1st example of this invention Sectional drawing which shows the shape of the discharge guide blade in the 2nd example of this invention Sectional drawing which shows the shape of the discharge guide blade in the 3rd example of this invention Sectional drawing which shows the shape of the discharge guide blade in the 4th example of this invention Sectional drawing which shows the shape of the discharge guide blade in the 5th example of this invention Sectional drawing which shows the shape of the discharge guide blade in the 6th example of this invention Side view of the excavating and stirring device in the comparative example AA line sectional view of FIG.

DESCRIPTION OF SYMBOLS 1 Centerline 2 Rotating shaft 3 Excavation blade 3a Claw 4 Agitation blade 5 Upper stopper 6 Lower stopper 7, 10 Co-rotation prevention blade 7a, 10a Boss part 8 Foreign material 9 Column outer periphery 11 Discharge guide blade 11a Guide side surface t1, t2 Interval

Claims (4)

A rotating shaft that rotates in the ground,
A drilling wing projecting at the lower end of the rotating shaft and drilling earth and sand;
Above the excavating blade, a boss part that circulates around the rotating shaft and is loosely fitted to the rotating shaft;
A joint rotation prevention wing whose base end is fixed to the boss portion and whose tip is located outside the excavation wing and is in contact with the natural ground,
Integrated with the co-rotation prevention wing, interposed between the co-rotation prevention wing and the excavation wing, and intersects the co-rotation prevention wing in a plan view, and foreign matter from the rotating shaft side to the natural ground side A drilling and stirring device with a co-rotation preventing wing comprising a discharge guide wing having a guide side surface for guiding. 2. The guide side surface of the discharge guide vane is formed so that a distal end portion of the discharge guide vane moves away from the excavation blade as compared to a base end portion close to the boss portion in plan view. The excavation and stirring device with the joint rotation prevention wing as described. The excavation and agitation device with a co-rotation preventing blade according to claim 2, wherein the guide side surface of the discharge guide blade is formed with a smooth curve in a plan view. The excavation and stirring device with a co-rotation preventing wing according to claim 2, wherein the guide side surface of the discharge guide wing is formed by a plurality of straight lines bent in a step shape in plan view.

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