JP3859918B2 - Ground improvement agitator with expansion recognition function - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention includes a ground improvement stirrer for forming a support for increasing the ground supporting force in the ground, in particular, an expansion blade having an expansion arm that opens and closes by forward and reverse rotation, and the expansion arm is enlarged. The present invention relates to a ground improvement agitator having a function of recognizing this.
[0002]
[Prior art]
In general, when a house or the like is built on soft ground, a ground improvement method is implemented in which a plurality of cylindrical bodies 6 as shown in FIG. . Further, in order to improve the supporting force per one cylinder, as shown in FIG. 8 (b), a ground improvement method for forming a columnar cylinder 7 having a plurality of nodes 8 on the cylinder is formed. There is also.
[0003]
Since the above-mentioned columnar body 7 with nodes has a node portion 8 having an outer shape larger than the outer diameter of the columnar body, the frictional force with the ground is increased as compared with the normal columnar body 6. Therefore, if a cylindrical body with a node is used, the number of cylindrical bodies to be formed can be reduced, the length of the cylindrical body can be shortened, and the ground improvement method can be simplified.
[0004]
Hereinafter, the ground improvement stirrer which forms the said cylindrical body with a node is demonstrated.
As shown in FIG. 9, the ground improvement agitator 1 is provided on a column 3 fixed by a construction machine 2 so as to be movable up and down, and a mixer 4 produces a solidifying agent slurry in which water and a solidifying agent are kneaded. The solidifying agent slurry is pumped by the pump 5 to the ground improvement stirrer 1.
[0005]
As shown in FIG. 10, the ground improvement stirrer 1 has a hollow rotary shaft 10 having a discharge port 10 a formed at the tip thereof, and a cutting tip 110 at the tip portion thereof, and the tip of the rotary shaft 10. It has a drilling head 11 provided so as not to block the discharge port 10a in a part, a drilling tip 120 on one edge side thereof, and an inclination of a certain angle with respect to a horizontal plane in the vicinity of the tip of the rotary shaft 10. A pair of drilling stirring blades 12 provided opposite to each other and the rotary shaft 10 above the drilling stirring blades 12 are provided so as to face each other so as to have a certain angle of inclination with respect to the horizontal plane. The pair of suppression stirring blades 13 and the expansion blade 14 provided on the rotary shaft 10 between the drilling stirring blade 12 and the suppression stirring blade 13.
The hole-sharing stirring blade 12 and the suppression stirring blade 13 are provided so as to protrude in a direction perpendicular to the rotary shaft 10, respectively, and the direction in which the hole-sharing stirring blade 12 protrudes and the suppression stirring blade 13 protrude. The direction is 90 degrees out of phase around the rotation axis 10.
[0006]
As shown in FIGS. 10 and 11, the expanding blade 14 has a pair of brackets 40 fixed to the rotary shaft 10 at regular intervals in the vertical direction and a support pin 41 penetrating the bracket 40 as a support shaft. , And a pair of enlarged arms 42 provided so as to be rotatable about an axis, and a excavating tip 420 is fixed to a tip portion of the enlarged arms 42. Furthermore, the bracket 40 is provided with four restriction pins 43 for restricting the rotation of the enlargement arm 42 so as to penetrate the bracket 40.
[0007]
The expansion arm 42 is plate-shaped, and a cutting tip 420 is fixed to the side of the tip side of the expansion arm 42 in the direction of rotation at the time of reversal. Further, as shown in FIG. 11, an arcuate portion 42a is provided at the proximal end of the expanding arm 42 so that the expanding arm 42 can rotate without contacting the regulating pin 43 with the support pin 41 as a support shaft. A corner portion 42b is formed so as to restrict the rotation of the expansion arm 42 by contacting the restriction pin 43 at the position.
[0008]
Thereby, as shown in FIG. 11 (a), when the rotary shaft 10 reverses (rotates counterclockwise), the expansion arm 42 opens in the direction in which the expansion arm 42 opens due to the resistance of centrifugal force and earth and sand. To turn. The enlargement arm 42 has its tip portion farthest from the rotary shaft 10 and the corner portion 42b abuts against the restriction pin 43 so that the rotation is restricted. It becomes larger than the rotating outer diameter of the stirring blade 13. On the other hand, as shown in FIG. 11B, when the rotary shaft 10 rotates in the forward direction (clockwise), it rotates until the side portion of the expansion arm 42 abuts against the regulation pin 43 due to the resistance of earth and sand. As a result, the rotating outer diameter of the expanding blade 14 becomes equal to the rotating outer diameter of the drilling stirring blade 12 or the suppression stirring blade 13.
[0009]
Next, a method for forming a knotted cylinder in the ground using the ground improvement stirrer 1 will be described with reference to FIG.
First, after positioning the ground improvement stirrer 1, the rotary shaft 10 is rotated forward, and the ground is dug by the drilling head 11 and the drilling stirring blade 12 (FIG. 12 (a)). At this time, the expansion arm 42 of the expansion blade 14 is in a state of being accommodated within the rotating outer diameter of the drilling stirring blade 12 as shown in FIG. And after the front-end | tip of the ground improvement stirrer 1 reaches the set depth, the solidifying agent slurry is pumped into the rotating shaft 10 of the ground improving stirrer 1 by the pump 5, and the solidifying agent slurry is transferred to the rotating shaft 10. While discharging from the discharge port 10a, the ground improvement stirrer 1 is pulled up while the rotating shaft 10 is rotated forward. Thereby, the drilling stirring blade 12 and the suppression stirring blade 13 mix and stir the earth and sand and the solidifying agent slurry (FIG. 12 (b)).
[0010]
After finishing the mixing and stirring of the earth and sand and the solidifying agent slurry, the rotating shaft 10 is reversed at an arbitrary depth. As a result, as shown in FIG. 11 (a), the enlarged arm 42 of the enlarged blade 14 has a tip portion that exceeds the rotational outer diameter of the drilling stirring blade 12 and has a larger outer diameter portion than when the cavity is dug first. The earth and sand are excavated, and the earth and sand and the solidifying agent slurry are mixed and stirred. In this state, the ground improvement stirrer 1 is moved up and down by the width of the node to be formed to form a node in the cylindrical body to be formed (FIG. 12 (c)). Thereafter, the rotating shaft 10 is rotated forward so that the expanding arm 42 is rotated to a state where it can be accommodated within the rotating outer diameter of the hole agitating blade 12 and pulled up to a predetermined depth, and then the rotating shaft 10 is reversed again. In the same manner as described above, a new node is formed in the cylindrical body to be formed (FIG. 12 (d)). Again, the rotating shaft 10 is rotated forward to rotate the expanding arm 42 so as to be within the rotating outer diameter of the hole agitating blade 12 and pull it up to a predetermined depth (FIG. 12 (e)). By repeating this, an arbitrary number of nodes are formed, the rotating shaft 10 is rotated forward, and the expansion arm 42 is rotated to a state that fits within the rotating outer diameter of the drilling stirring blade 12 to improve the ground improvement stirring. The machine 1 is pulled up (FIG. 12 (f)).
By repeating such a series of operations, an arbitrary number of knotted cylinders are produced on the ground, and when a certain time elapses, the solidifying agent slurry is hardened and a knotted cylinder is formed.
[0011]
[Problems to be solved by the invention]
As described above, when the nodal portion is formed in the cylindrical body by the ground improvement stirrer 1, it is necessary to reverse the rotation shaft 10 and enlarge the rotation outer diameter of the expansion blade 14. Since it is in the ground, it cannot be confirmed on the ground whether or not the expansion arm 42 is open. For this reason, even if foreign matter such as rocks in the ground obstructs the opening / closing operation of the expansion arm 42 and the expansion arm 42 does not open and the rotation outer diameter of the expansion blade 14 does not expand, a desired node is added to the cylindrical body. Construction is performed as if the portion was formed, and as a result, the ground may not be strengthened to the target strength.
This invention is made | formed in view of said point, and it aims at providing the means which can confirm from the ground whether the expansion blade provided in the ground improvement stirrer expanded.
[0012]
[Means for Solving the Problems]
The ground improvement stirrer with an expansion recognition function according to claim 1 of the present invention, which has been made to achieve the above object, includes an expansion blade whose expansion arm opens and closes by forward and reverse rotation, and excavates or stirs the ground by rotation. In the ground improvement stirrer that performs one or both of the above, the surface of the stirrer is stretched and stretched between members located at positions where the expansion arm open / close track is inserted, and expands and contracts when the expansion arm contacts and opens and closes. Detecting a line covered with a tubular protective tube having an opening hermetically sealed with a stopper and one or both of the line extending or retracting a predetermined threshold or more and outputting a detection signal It comprises a detection means and a display means for receiving the detection signal and displaying the open / closed state of the enlargement arm.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a diagram for explaining a configuration of a ground improvement stirrer with an enlarged recognition function according to an embodiment of the present invention. As shown in the figure, the ground improvement stirrer 100 with this enlargement recognition function is provided so as to be movable up and down on a column 3 fixed by the construction machine 2, and two lights 16 a and 16 b are provided at the end of the ground side. Is provided.
In addition, although not shown in figure, the solidification agent slurry which knead | mixed water and a solidification agent is produced with the mixer 4 similarly to the above, and this solidification agent slurry is pumped by the above-mentioned ground improvement stirrer 100 with an expansion recognition function. It is supposed to be pumped.
[0015]
2 (a) shows the front side of the ground improvement stirrer 100, and FIG. 2 (b) shows the side surface of the ground improvement stirrer 100. As shown in each figure, On the ground side of the ground improvement stirrer 100 with the enlargement recognition function, there is a hollow rotary shaft 10 having a discharge port 10a formed at the tip thereof, and a cutting tip 110 at the tip portion. It has a drilling head 11 provided so as not to block the discharge port 10a in a part, a drilling tip 120 on one edge side thereof, and an inclination of a certain angle with respect to a horizontal plane in the vicinity of the tip of the rotary shaft 10. A pair of drilling stirring blades 12 provided opposite to each other and the rotary shaft 10 above the drilling stirring blades 12 are provided so as to face each other so as to have a certain angle of inclination with respect to the horizontal plane. Between the pair of suppression stirring blades 13 and the drilling stirring blades 12 and the suppression stirring blades 13. And larger wings 15 provided on the rotating shaft 10 is provided.
The hole-sharing stirring blade 12 and the suppression stirring blade 13 are provided so as to protrude in a direction perpendicular to the rotary shaft 10, respectively, and the direction in which the hole-sharing stirring blade 12 protrudes and the suppression stirring blade 13 protrude. The direction is 90 degrees out of phase around the rotation axis 10.
[0016]
As shown in FIGS. 2 and 3, the expansion wing 15 has a pair of brackets 50 fixed to the rotary shaft 10 at regular intervals in the vertical direction and a support pin 51 penetrating the bracket 50 as a support shaft. A pair of enlarged arms 52 is provided so as to be rotatable about an axis, and the base end portion of the enlarged arms 52 is sandwiched between a pair of spacers 53 and a bracket 50, through which the support pins 51 penetrate. It has become a thing. The bracket 50 is provided with two regulation pins 54 a and 54 b for regulating the rotation of the enlargement arm 52 so as to penetrate the bracket 50.
[0017]
The restriction pin 54a is located at the position where the tip end portion is farthest from the rotary shaft 10 when the enlargement blade 15 is reversed and the enlargement arm 52 is opened, that is, the rotation outer diameter of the enlargement blade 15 is maximum. Is provided so as to restrict the rotation of the enlargement arm 52. On the other hand, the restriction pin 54b is a position where the rotating outer diameter of the expanding blade 15 becomes equal to the rotating outer diameter of the drilling stirring blade 12 when the expanding blade 15 rotates forward and the expanding arm 52 rotates in the closing direction. Thus, the rotation of the expansion arm 52 is restricted.
[0018]
Further, as shown in FIGS. 2 and 3, the pair of brackets 50 are arranged in the vicinity of the regulation pins 54 a and 54 b that regulate the rotation of the one enlargement arm 52, and the rotation trajectory of the enlargement arm 52. A wire rope 55 is stretched so as to cross the line. Each bracket 50 is provided with an insertion hole through which the wire rope 55 is inserted, and one end of each wire rope 55 is fixed by a stopper while being inserted through the insertion hole of the lower bracket 50. . On the other hand, the other end of each wire rope 55 is inserted through the insertion hole of the upper bracket 50 and penetrates into the rotary shaft 10, and the wire rope 55 stretched in the vicinity of the restriction pin 54 a has an expansion arm. The wire rope 55 stretched in the vicinity of the regulation pin 54b is connected to the light 16b for indicating that the expansion arm is closed. The material of the wire rope 55 is preferably made of stainless steel in consideration of rust prevention properties and the like.
[0019]
The enlargement arm 52 is plate-shaped, and the excavation tip 520 is fixed to the tip side of the enlargement arm 52 at the side portion in the rotation direction at the time of reversal. Further, as shown in FIG. 3, the base end portion of the expansion arm 52 has an arc portion 52 a that allows the expansion arm 52 to rotate without contacting the restriction pin 54 a with the support pin 51 as a support shaft, A corner portion 52b that restricts the rotation of the enlargement arm 52 by contacting the restriction pin 54a at a predetermined position is formed.
[0020]
Further, each of the pair of expansion arms 52 is provided with three excavation stirring pins 56 each. Of the three excavation stirring pins 56 provided on one of the pair of expansion arms 52, the first one is provided to protrude upward from the tip of the expansion arm 52, and the second is It is provided so as to protrude downward from the first excavation stirring pin 56 at a position on the rotary shaft 10 side, and the third is located above the position of the second excavation stirring pin 56 on the rotary shaft 10 side. It is provided so as to protrude.
[0021]
Of the three excavation stirring pins 56 provided on the other expansion arm 52, the first is provided at the tip of the expansion arm 52 so as to protrude downward, and the second The third excavator is provided so as to protrude upward from the first excavation stirring pin 56 to the position on the rotary shaft 10 side, and the third excavator is located below the second excavation stirring pin 56 to the position on the rotary shaft 10 side. It is provided so as to protrude to the side. Each of the excavation stirring pins 56 has a cylindrical shape and is detachably fixed to the expansion arm 52.
[0022]
FIG. 4 is a cross-sectional view for explaining the details of the state in which the wire rope 55 is inserted through the insertion hole of the upper bracket 50. The wire rope 55 extends from the upper bracket 50 to the lights 16a and 16b. The portion up to the connection with is covered with a tubular wire rope protective tube 550. As shown in the figure, the wire rope protective tube 550 is provided with an opening 550a in the vicinity of the connection end with the bracket 50, and the opening 550a is sealed with a stopper 551. The opening 550 a is for injecting the grease 553 into the wire rope protective tube 550, and formed at the connection end of the wire rope protective tube 550 between the inside and the wire rope 55. The space is always filled with grease 553. This prevents the improved soil, which is a mixture of earth and sand or slurry, from entering the inside of the wire rope protective tube 550 from the insertion hole of the bracket 50. Further, by further press-fitting the grease 553 from the opening 550a, it is possible to discharge the grease 553 contaminated with earth and sand from the insertion hole of the bracket 50.
[0023]
FIG. 5 is a cross-sectional view showing a cross section of the rotary shaft 10. As shown in the figure, the rotary shaft 10 includes a hexagonal rod 101 provided with a hollow portion for pumping the solidifying agent slurry, and a rod. A space formed between the inner tube 102 and the outer tube 103, which includes a columnar inner tube 102 inscribed in the inner tube 101, and a columnar outer tube 103 that includes the inner tube 102 and the wire rope protection tube 550. Is provided with a wire rope protective tube 550. When the rotary shaft 10 rotates, the inner tube 102, the wire rope protection tube 550, and the outer tube 103 rotate together with the rod 101 as an axis.
In order to secure the connection between the inner tube 102 and the outer tube 103, a space formed between the inner tube 102 and the outer tube 103 is further provided with a wire at a position indicated by a dotted line in the drawing. It is desirable to provide a rope protection tube 550. When the wire rope protective tube 550 stretches the wire rope similar to the two wire ropes 55 described above also in the vicinity of each of the regulation pins 54a and 54b that regulate the rotation of the other expansion arm 52. In addition, it can be used for inserting the wire rope.
[0024]
Each of the lights 16a and 16b is provided with a limit switch 160 at a connecting portion with the wire rope 55. The limit switch 160 is not particularly limited as long as it detects the expansion and contraction of the wire rope 55 and lights or extinguishes the lights 16a and 16b. For example, a limit switch 160 as shown in FIG. 6 is used.
[0025]
As shown in FIG. 6, the limit switch 160 is provided with a pair of plate-like bodies 162 having contact terminals 161 facing each other, and is contacted by a spring 163 provided between the pair of plate-like bodies 162. The terminal 161 is normally in a separated state. Each of the pair of plate-like bodies 162 is provided with an insertion hole, and the wire rope 55 is inserted into the insertion hole of each plate-like body 162 and is a stopper 164 on the upper surface side of the upper plate-like body 162. It is fixed by. As a result, the wire rope 55 is always given an upward pulling force by the spring 163. A conductive cord 165 is connected to the contact terminal 161, and the other end of the conductive cord 165 is connected to the light 16. Further, these are entirely covered by a cover 166. The member for fixing the limit switch 160 may be either the light 16a, 16b, or the inner tube 102 or the outer tube 103 of the rotating shaft 10, and is not particularly limited.
[0026]
The distance between the pair of plate-like bodies 162 is equivalent to the length by which the wire rope 55 is pulled when the enlargement arm 52 is opened or closed.
Accordingly, when the wire arm 55 is pulled in the direction shown by the opening and closing of the enlargement arm 52, the spring 163 contracts and the contact terminals 161 come into contact with each other, and the conductive cord 165 becomes conductive.
[0027]
The expansion arm 52 is opened and closed as follows.
As shown in FIG. 3 (a), when the rotary shaft 10 is reversed (rotates counterclockwise), the enlarged arm 52 has the corner 52b connected to the regulating pin 54a due to the centrifugal force and the resistance of earth and sand. The expansion arm 52 rotates until it abuts. At this time, the distal end portion of the expansion arm 52 is in the state farthest from the rotation shaft 10, and the rotation outer diameter of the expansion blade 15 is expanded to be larger than the rotation outer diameter of the drilling stirring blade 12 or the suppression stirring blade 13. . At the same time, the corner 52b of the expanding arm 52 is brought into contact with and pulled by the wire rope 55 stretched in the vicinity of the regulation pin 54a. On the other hand, as shown in FIG. 3B, when the rotating shaft 10 rotates in the forward direction (clockwise rotation), it rotates until the side portion of the enlarged arm 52 comes into contact with the regulation pin 54b due to resistance of earth and sand. Move. Thereby, the rotation outer diameter of the expansion blade 15 is reduced, and becomes equal to the rotation outer diameter of the drilling stirring blade 12 or the suppression stirring blade 13. At the same time, the side portion of the expansion arm 52 comes into contact with and pulls the wire rope 55 stretched in the vicinity of the regulation pin 54b. In addition, the rotation outer diameter of the expansion blade 15 can be further reduced by changing the position where the restriction pin 54b is to be provided on the bracket 50.
[0028]
7A and 7B show details of the state in which the expansion arm is opened and closed. FIG. 7A is a side view seen from the viewpoint X in FIG. 3A, and FIG. It is the side view which looked at 3 (b) from the viewpoint Y. When the rotary shaft 10 is reversed, as shown in FIG. 7A, the enlargement arm 52 rotates in the opening direction, the corner 52b of the enlargement arm 52 abuts on the wire rope 55, and further, the restriction pin 54a The wire rope 55 is pulled by rotating until it abuts. As a result, the spring 163 of the limit switch 160 shown in FIG. 6 is retracted, the contact terminals 161 come into contact with each other, and the limit switch 160 becomes conductive. In response to this, the light 16a is turned on to indicate that the expansion arm is opened.
On the other hand, when the rotary shaft 10 rotates in the forward direction, the enlargement arm 52 rotates in the closing direction, the corner 52b is separated from the wire rope 55, and the contact terminal 161 of the limit switch 16 is separated. Is cut off, and the light 16a is turned off.
[0029]
Further, as shown in FIG. 7B, the rotating shaft 10 rotates in the forward direction so that the enlargement arm 52 rotates, and the side portion of the enlargement arm 52 is stretched in the vicinity of the regulation pin 54b. The wire rope 55 is pulled by rotating until it abuts against the rope 55 and further abuts against the regulation pin 54b. As a result, the spring 163 of the limit switch 160 shown in FIG. 6 is retracted, the contact terminals 161 come into contact with each other, and the limit switch 160 becomes conductive. In response, the light 16b is turned on to indicate that the expansion arm is closed.
Therefore, the operator confirms on the ground whether the expanding blade 15 is in an expanded state or a closed state, depending on whether the light 16a or the light 16b is lit.
[0030]
Thus, according to the ground improvement stirrer 100 with the enlargement recognition function according to the present embodiment, the lights 16a and 16b are provided at the end on the ground side, the enlargement blade 15 is reversed, and the enlargement arm 52 is rotated. The wire rope 55 is stretched so that the corner portion 52b of the enlargement arm 52 abuts on the trajectory of the enlargement arm 52, and the enlargement wing 15 rotates forward so that the enlargement arm 52 rotates. The wire ropes 55 are stretched so that the side portions are in contact with each other, and a limit switch 160 that detects that each wire rope 55 has been pulled for a certain distance is provided. When the limit switch 160 becomes conductive, the light 16a or the light 16b Since the light is turned on, the operator confirms whether the enlarged arm 52 is open or closed by turning on the lights 16a and 16b. It is possible.
As a result, it is possible to prevent the ground from being strengthened to the desired strength, and to prevent the ground from being strengthened without expanding the rotating outer diameter of the expansion wing 15, and to reliably form the node in the cylindrical body. can do.
[0031]
In the present embodiment, the wire rope 55 is stretched in the vicinity of the regulation pin 54a and the regulation pin 54b of the bracket 50. However, the wire rope 55 is stretched only in the vicinity of the regulation pin 54a, and the expansion arm Even if it can confirm only that 52 expanded from the ground, in the construction of ground reinforcement, the effect that a node part can be certainly formed in a cylinder can be acquired.
[0032]
In this embodiment, the wire rope 55 is stretched between the pair of brackets 50. However, the wire rope 55 is linked between the bracket 50 and the expansion arm 52 in conjunction with the opening / closing operation of the expansion arm 52. 55 may be stretched so as to expand and contract.
[0033]
Further, in the present embodiment, the limit switch 160 is used as a means for detecting the expansion and contraction of the wire rope 55. However, the wire rope 55 is configured by another configuration, for example, a configuration in which the wire rope 55 is wound. A sensor that detects the length of expansion / contraction and that outputs a detection signal when expansion / contraction exceeds a certain threshold value may be used.
[0034]
In this embodiment, the lights 16a and 16b are used as means for displaying the opening / closing of the enlargement arm 52. However, a display panel for displaying the opening / closing state of the enlargement arm 52 on the screen or the enlargement arm 52 is provided. You may use the speaker etc. which emit an audio | voice or an alarm sound in the open state.
[0035]
【The invention's effect】
As described above, according to the ground improvement stirrer with the expansion recognition function according to claim 1 of the present invention, the ground improvement stirrer includes the expansion blade that opens and closes the expansion arm by forward and reverse rotation, and the ground is excavated or stirred by the rotation. One or both ground improvement agitators are stretched between members located at the position where the expansion arm open / close track is inserted, and expand and contract when the expansion arm contacts and opens and closes. A detection that outputs a detection signal by detecting one or both of a rope covered with a tubular protective tube having an opening hermetically sealed by a stopcock and that the rope has expanded or retracted over a certain threshold. And a display means for receiving the detection signal and displaying the open / closed state of the enlargement arm so that the open / closed state of the enlargement arm can be confirmed on the ground. Unterminated ground Construction of reinforced is performed, it is possible to prevent to be a state where the ground until the desired intensity is not reinforced, to form a securely knuckles support to strengthen the ground, expanding recognition function Ground The structure of the improved stirrer can be simplified.
[Brief description of the drawings]
FIG. 1 is a diagram for explaining a ground improvement stirrer 100 with an enlarged recognition function according to an embodiment of the present invention.
FIGS. 2A and 2B are a front view and a side view showing a configuration of a ground improvement stirrer with an enlargement recognition function according to an embodiment of the present invention.
FIG. 3 is a plan view showing a state of the expansion blade 15 during normal rotation and reverse rotation.
4 is a cross-sectional view for explaining details of a state in which the wire rope 55 is inserted into an insertion hole provided in the bracket 50. FIG.
FIG. 5 is a cross-sectional view for explaining a detailed configuration of a rotating shaft 10;
6 is a cross-sectional view showing a configuration of a limit switch 160. FIG.
FIG. 7 is a diagram showing a detailed state of the expansion blade 15 at the time of forward rotation and reverse rotation.
FIG. 8 is a schematic diagram showing a cylindrical body and a cylindrical body with a node for increasing the supporting force of the ground.
FIG. 9 is a schematic view showing an apparatus used in the ground improvement method.
FIG. 10 is a front view and a side view showing a configuration of a conventional ground improvement stirrer 1.
FIG. 11 is a plan view showing a state of the expansion blade 14 at the time of normal rotation and reverse.
FIG. 12 is a schematic diagram for explaining a method of forming a knurled cylinder using a conventional ground improvement stirrer 1;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Rotating shaft 100 Ground improvement stirrer with expansion recognition function 11 Drilling head 12 Drilling stirring blade 13 Suppression stirring blade 15 Expansion blade 16a, 16b Light 160 Limit switch 52 Expansion arm 55 Wire rope 6 Cylindrical body 7 Knotted cylindrical body

Claims (1)

In a ground improvement stirrer that has an expansion blade that opens and closes the expansion arm by forward and reverse rotation, and that excavates and / or agitates the ground by rotation, between the members located at the position where the expansion arm opening and closing track is inserted A cord that is stretchably stretched and expands and contracts by opening and closing when the expansion arm comes into contact with the cord, and is covered with a tubular protective tube having an opening hermetically sealed with a stopper on the surface thereof, and the cord Is provided with a detection means for detecting one or both of expansion or contraction of a predetermined threshold or more and outputting a detection signal, and a display means for receiving the detection signal and displaying an open / closed state of the enlargement arm. A ground improvement agitator with an enlarged recognition function.

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