JP2006348644A - Excavation head and excavator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an excavation head capable of smoothly excavating and stirring without large vibration and noise with a simple constitution, preventing a bit from being damaged easily, avoiding the slippage of an excavation position and smoothly excavating hard soil, and an excavator. <P>SOLUTION: The excavation head 23 is pivoted on an excavation shaft of an excavator which is rotated and simultaneously vertically moved to stir excavated soil and jet consolidated material from the tip end for constructing the consolidated body underground. A plurality of excavation blades 22 are spirally provided around a rotary shaft 20 mounted to the tip end of the excavation shaft, and the tip end of the rotating shaft 20 and the excavation blades 22 are provided with excavating claws 21 installed in a plurality of stages along the axial direction, and a plurality of the excavating claws are arranged in a plurality of rows in the radial direction in each stage, and a plurality of the excavating claws 21 are provided to one row. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an excavation head that is attached to a tip of an excavator that excavates an excavation hole for a retaining wall such as a soil column wall, and a multi-axis excavator (auger) including the excavation head.

  The multi-axis excavator used when the soil column wall is constructed by the in-situ soil mixing method (SMW method) is excavated in a drive mechanism 4 including a hydraulic motor and a speed reducer, for example, as shown in FIGS. A plurality of excavation shafts 5 (five in the drawing) are arranged in parallel, and the rods are bound by a binding band 9 for steadying.

  The excavation shaft 5 is provided with an excavation head 5a at the tip, and an excavation blade 5b serving as an agitation blade by an intermittent screw blade, but is additionally provided with an agitation blade 10 as shown in FIG. It doesn't matter if you do. Although not shown in the figure, the excavation shaft 5 is a hollow shaft that allows a caking liquid such as cement milk to flow inside, and can be poured out from the discharge port of the excavation head 5a.

  The drive mechanism 4 is supported by a wire from a top sheave 3 of a leader mast 2 standing on a base machine 1 such as a crawler while the excavation shaft 5 is connected. Furthermore, the drive mechanism 4 engages the curved bracket 6 provided on the back surface with the leader 7 provided along the leader mast 2. In the figure, reference numeral 8 denotes a neck-like steady rest provided at the lower end of the leader mast 2, and the excavation shaft 5 penetrates vertically.

  The excavation shaft 5 is rotationally driven by the drive mechanism 4 and excavation is carried out in the shape of a cone with the excavation head 5a. During the excavation, a caking liquid such as cement milk is discharged from the excavation head 5a, and the soil is in situ in the soil. The soil cement wall body of the preceding element is formed by mixing with.

  Further, when excavating by rotating a plurality of excavating shafts 5 as described above, the excavating shafts 5 so that the excavating diameters of adjacent excavating shafts 5 partially overlap each other in order to use the soil cement wall as a continuous wall. , The tip position of the excavation shaft 5 is alternately shifted so that the excavation head 5a does not collide, and the excavation shafts 5 adjacent to each other rotate in the opposite direction. For example, the excavation shaft 5 in which the excavation head 5a is positioned forward in the axial direction (both ends and the central excavation shaft 5 in the figure) rotates to the right when excavating toward the distal direction, and is located between the excavation heads 5a. The excavation shaft 5 positioned at the rear in the axial direction rotates in the left direction.

  By the way, as shown in FIG. 6, the excavation claws provided in the excavation head 5a have been generally arranged in the same plane. When such an excavation head 5a is used, since all the excavation claws 11 are in contact with the excavation target surface at the same time, the pressing force in the ground direction of the excavation shaft 5 is distributed over the entire excavation diameter, When the ground is hard ground, there was a problem that excavation did not go smoothly.

  Further, when the excavation shaft 5 positioned forward in the axial direction rotates to the right, the entire three axes of the excavation shaft 5 bound by the binding band 9 touch in the right rotation direction, and the entire three axes tend to twist and rotate. The torsion becomes larger as the depth increases, and the excavation direction of the excavation hole tends to shift in the horizontal direction. When dispersed, the excavation direction is more likely to deviate from the center position.

By the way, the technique which can eliminate this inconvenience is disclosed in the following patent documents.
Japanese Patent Application Laid-Open No. 07-150546 JP 09-177462 A JP 07-293178 A JP 2002-129863 A

  As shown in FIG. 7, in the excavator that is a soil cement pile building device described in Patent Document 1, the rotary shaft 16 has a double shaft structure of an outer shaft 16a and an inner shaft 16b, and the inner shaft 16b A second stage excavation head in which an excavation bit (excavation claw) 9a is disposed above the first stage excavation head 18 and at an outer position with respect to the first stage excavation head 18 that is attached to the shaft. 19 is provided on the outer periphery of the outer shaft 16a, and the first stage excavation head 18 is driven at a low speed and the second stage excavation head 19 is driven at a high speed.

  According to this, the first stage excavation head 18 is driven at a low speed rotation to perform the first stage excavation, and then the second stage excavation head 19 is driven at a high speed rotation. Since the outer diameter of the excavation part of the eye excavation head 18 is excavated to create a large-diameter hole, the first-stage excavation head is controlled by keeping the first-stage excavation diameter smaller than the final excavation diameter. The excavation load of 18 can be reduced, and further, since the excavation head 19 in the second stage only needs to excavate only the outer periphery of the already excavated portion, the excavation load can be reduced.

  That is, by reducing the excavation load applied to the excavation head, it is possible to smoothly excavate even on hard ground, and it is possible to make it difficult to shift the excavation direction from the center position.

  Further, in Patent Document 2, as shown in FIG. 8, the rotary shaft 17 is attached to the upper portion of the down hammer 12 that has a function of jetting a fluid at a high pressure downward from the tip and drills the rock by moving up and down. An apparatus for drilling a sediment layer and a rock mass, which is provided with a rock excavation bit 13 having a diameter larger than that of the down hammer 12 and drilled by rotation, is disclosed.

  This is because even when the ground to be excavated is hard ground, the down hammer 12 is driven up and down while the fluid is ejected to drill the ground, and the down hammer 12 drills the ground to a small diameter. Since the periphery is drilled into a large-diameter hole by the rotation of the large-diameter rock drilling rotary bit 13, the excavation load can be reduced smoothly while maintaining the center position in the excavation direction.

  In Patent Document 3, as shown in FIG. 9, the excavation head 14 that is pivotally attached to the tip of the rotary shaft 15 has a radial end edge on the descending side of the blade plate 14 a as an attachment base to the rotary shaft 15. The excavator shaft of the excavator in which the excavator claw 11a is arranged along the inclined edge 14b is disclosed as shown in FIG. The excavation claw 11b is provided so as to be located in the central direction as it goes in the direction of the tip of the excavation shaft.

  As a result, only the excavation claws 11a and 11b positioned at the center of the rotation direction at the time of excavation first come into contact with the excavation target surface, so that the pressing force from the rotation shaft is dispersed over the entire excavation diameter. The excavation load can be reduced and smooth excavation can be performed while maintaining the center position in the excavation direction.

  However, since the excavator described in Patent Document 1 changes the rotation speed between the first-stage excavation head and the second-stage excavation head, it has a complicated configuration such as a multi-axis rotation axis. It takes a lot of labor and cost to produce.

  Moreover, in the apparatus described in Patent Document 2, the down hammer is suitable for rocking the bedrock by up-and-down driving. However, the rotating shaft is moved up and down to stir fluid such as a consolidated material and earth and sand. At that time, the earth and sand are tightened by the vertical movement of the down hammer, and the presence of the down hammer hinders smooth stirring. Furthermore, since the down hammer uses a vertical hit / vibration force during excavation, noise and vibrations applied to the surroundings also increase.

  Further, in the excavators of Patent Document 3 and Patent Document 4, since all the excavation claws are arranged to be inclined with respect to the excavation direction, a plurality of pressing forces from the excavation shaft are generated particularly at the tip portion of the excavation head. Although it will not be distributed to the excavation claws, the load applied to each excavation claw from the excavation surface such as the ground becomes too large, especially because the excavation claw at the tip is heavily loaded, so the excavation claws are easily damaged There is a risk of it.

  The object of the present invention is to eliminate the inconvenience of the conventional example, and with a simple configuration, can excavate smoothly without large vibration and noise, and can prevent the excavation position from shifting without easily damaging the bit. Another object of the present invention is to provide an excavation head capable of smoothly excavating hard ground and an excavator equipped with the excavation head.

  In order to achieve the above-mentioned object, the present invention according to claim 1 is configured such that the excavating shaft is rotated and moved up and down to stir the excavated soil, and the consolidated material is ejected from the tip portion and consolidated into the ground. In the excavation head that is attached to the excavation shaft of the excavator that forms the body, a plurality of excavation blades are provided spirally around the rotary shaft that is attached to the tip of the excavation shaft, and the excavation claw is axially provided on the rotary shaft tip and the excavation blade. A plurality of stages are provided along the line, and a plurality of excavation claws are arranged in the radial direction in each stage, and a plurality of excavation claws are provided in one line.

  According to the first aspect of the present invention, the excavation claw is provided in a plurality of stages along the axial direction. Therefore, when the tip of the excavation head comes into contact with the excavation surface such as the ground, Since the pressure is concentrated on the excavation claw of the stage located at the tip of the excavation head, the excavation position does not shift, and even the hard ground can be excavated smoothly. Also, at this time, a plurality of digging claws are arranged in each stage in the radial direction, and a plurality of digging claws are provided in one row. It is possible to prevent the load from being overloaded and to reduce the damage to the claw. In addition, since the drilling claw is provided on the spiral drilling blade and the rotating shaft, the pressing force and rotational force from the drilling shaft can be efficiently applied to the drilling claw, and the rotating shaft is complicated such as a double shaft structure. Even without a simple structure, the excavation position can be prevented and the hard ground can be smoothly excavated with a simple structure. Moreover, since no down hammer is used, excavation does not involve large vibrations and noises, and stirring by vertical movement of the excavating shaft can be performed smoothly with little resistance.

  According to a second aspect of the present invention, in an excavator provided with a plurality of excavation shafts in which the excavation diameters of adjacent excavation shafts partially overlap, the excavation shafts are arranged by alternately shifting the tip positions of the excavation shafts. The gist of the invention is that the excavation head of the shaft is the excavation head according to claim 1.

  According to the second aspect of the present invention, since the excavation head of the excavation shaft located in front of the excavation direction is the excavation head according to the first aspect, the excavation head that reaches the excavation surface of the ground or the like first. In this case, the excavation position does not shift and the hard ground can be excavated smoothly. And since the excavation axis adjacent to the excavation axis located in front of the excavation direction is located in the rear of the excavation direction and the excavation diameters partially overlap, the load required for excavation is larger than the excavation axis located in front of the excavation direction. Therefore, the correct position is excavated following the previously excavated portion, and the excavator as a whole can prevent the excavation position shift and smoothly excavate the hard ground.

  The excavation head of the present invention and the excavator equipped with the excavation head can be excavated and smoothly stirred without large vibrations and noises with a simple configuration, and can prevent the excavation position from shifting without easily damaging the bit. Hard ground can be excavated smoothly.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a front view showing an embodiment of an excavation head according to the present invention, and FIG. 2 is a side view of the same.

  As shown in FIGS. 1 and 2, the excavation head 23 of the present invention is provided with a spiral excavation blade 22 around a rotary shaft 20 having a base portion 20 a that is attached to an excavation shaft of an excavator described later. The front end of the excavating blade 22 in the excavation direction (the lower end in FIG. 2) is rearward in the excavation direction than the front end of the rotary shaft 20 and perpendicular to the rotary shaft 20.

  Excavation claws 21 are provided at the tip of the excavation blade 22 and the tip of the rotary shaft 20. At this time, the excavation claws 21 are arranged in a plurality of rows along the radial direction from the axis center. In this embodiment, two rows are arranged, and each row is provided on the opposite side from the axial center. The number of excavation claws 21 provided per row is plural. For example, the number of excavation claws 21a provided at the tip of the rotary shaft 20 is two per row, and the number of excavation claws 21b provided at the tip of the excavation blade 22 is two to three per row.

By doing in this way, the excavation claw 21a provided on the rotating shaft 20 becomes the first stage where the excavation claw 21b provided on the excavation blade 22 contacts the excavation surface next. In the second stage, the excavation claws 21 are provided in a plurality of stages.

In this embodiment, two excavation blades 22 are provided with one excavation blade 22a, and the other with three excavation claws 21b. Further, the row of excavation claws 21b provided on the excavation blades 22 and the row of excavation claws 21a provided on the rotary shaft 20 are provided so as to be shifted from each other by 90 degrees.

  One embodiment near the excavation axis of an excavator equipped with the excavation head 23 is shown in FIG. The excavator in the present embodiment is a multi-axis excavator having five excavating shafts 5. In the figure, 10 is a stirring blade, 5b is an excavating blade, 9 is a binding band, and the overall configuration is shown in FIG. 4 and FIG. Since it has already been described, a detailed description thereof is omitted here.

  When excavating by rotating a plurality of excavation shafts 5 as described above, the distance between the excavation shafts 5 is such that the excavation diameters of adjacent excavation shafts 5 partially overlap each other in order to use the soil cement wall as a continuous wall. In addition, the tip positions of the excavation shafts 5 are alternately shifted so that the excavation heads 23 do not collide with each other, and the three excavation shafts 5 positioned at the left and right ends and the center are moved forward in the excavation direction, and the two excavation shafts therebetween Position 5 behind the excavation direction.

  The excavation head 23 is pivotally attached to the tips of the three excavation shafts 5 located in front of the excavation direction. Moreover, the excavation head 5a attached to the tip of the excavation shaft 5 located in the rear of the excavation direction may be one in which excavation claws are arranged on one plane as in the conventional case.

  Next, the operation will be described. First, the position of the excavating shaft 5 of the excavator is adjusted to a predetermined location on the ground to be excavated, and the excavating shaft 5 is rotationally driven by a drive mechanism (not shown). When the five excavation shafts 5 are rotated toward the ground excavation surface while rotating, the excavation heads 23 of the three excavation shafts 5 located in front of the excavation direction reach the excavation surface first, and the excavation head 23 The excavation is performed in a cone shape.

  Since the excavation claw 21 of the excavation head 23 is provided in two stages, the first excavation claw 21a first contacts the excavation surface. Thereby, the pressing force from the excavation shaft 5 is concentrated on the first excavation claw 21a, so that the excavation position does not shift, and even the hard ground can be excavated smoothly. In addition, since the first stage excavation claws 21a are arranged in a plurality of rows in the radial direction and a plurality of excavation claws are provided in one row, the plural excavation claws 21a simultaneously contact the excavation surface, and each excavation claw It is possible to prevent the load on the excavation claw 21a from being reduced by preventing an excessive load on the 21a. Further, the same arrangement can be made for the second level excavation claw 21b, so that the damage to the excavation claw 21b can be reduced.

Further, since the excavation claw 21 is provided on the spiral excavation blade 22 and the rotary shaft 20, the pressing force and the rotational force from the excavation shaft 5 can be efficiently applied to the excavation claw 21, and the rotary shaft 20 is reduced to 2 Even without a complicated structure such as a heavy shaft structure, the displacement of the excavation position can be prevented and the hard ground can be smoothly excavated with a simple structure. Moreover, since no down hammer is used, excavation does not involve large vibrations and noises.

  Furthermore, when the excavation shaft 5 is rotated downward and the excavation is continued, the excavation heads 5a of the two excavation shafts 5 located rearward in the excavation direction reach the excavation surface, and the excavation head 5a excavates in a cone shape. I do. In order to prevent the excavation blades 5b and the stirring blades 10 of the adjacent excavation shafts 5 from colliding with each other due to the rotation of the excavation shafts 5, the adjacent excavation shafts 5 are rotated in the opposite directions.

  At this time, since the excavation diameter of the excavation head 5a partially overlaps with the excavation diameter of the excavation head 23, the load required for excavation is less than that of the excavation head 23 of the excavation shaft 5 located in front of the excavation direction. The correct position will be excavated following the excavated location, and the excavator as a whole can prevent excavation position shift and smooth excavation of hard ground.

  Then, a solidified liquid such as cement milk is discharged from the excavation head 23 and the excavation head 5a during excavation, and further moved up and down while rotating the excavation shaft 5, thereby mixing with the original soil in the soil and leading elements. The soil cement wall body is constructed. Since neither the excavation head 23 nor the excavation head 5a is a screw type without using a down hammer, the agitation between the consolidated liquid and the original soil by the vertical movement of the excavation shaft 5 can be performed smoothly with little resistance. .

It is a front view showing one embodiment of the excavation head of the present invention. It is a side view which shows one Embodiment of the excavation head of this invention. It is a side view showing one embodiment near the excavation axis of the excavator of the present invention. It is a front view which shows an example of the conventional multi-axis excavator. It is a side view which shows an example of the conventional multi-axis excavator. It is a side view which shows one example of the excavation axis | shaft vicinity of the conventional excavator. It is a side view which shows the 2nd example of the conventional excavation head. It is a side view which shows the 3rd example of the conventional excavation head. It is a side view which shows the 4th example of the conventional excavation head. It is a side view which shows the 5th example of the conventional excavation head.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Base machine 2 Leader mast 3 Top sheave 4 Drive mechanism 5 Excavation shaft 5a Excavation head 5b Excavation blade 6 Curved bracket 7 Leader 8 Anti-rest 9 Binding band 9a Excavation bit 10 Stirring blade 11, 11a, 11b Excavation claw 12 Down hammer 13 Rock Rotating excavation bit for cutting 14 Excavation head 14a Blade 14b Inclined edge 15, 16 Rotating shaft 16a Outer shaft 16b Inner shaft 17 Rotating shaft 18 First stage excavating head 19 Second stage excavating head 20 Rotating shaft 20a Base 21 , 21a, 21b Drilling claws 22, 22a Drilling blade 23 Drilling head

Claims (2)

  In the excavation head which is moved up and down while rotating the excavation shaft, stirs the excavated soil and ejects the consolidated material from the tip, and attaches to the excavator shaft of the excavator that forms the consolidated body in the ground, A plurality of excavating blades are provided in a spiral shape around the rotary shaft attached to the tip, and a plurality of excavation claws are provided along the axial direction on the distal end of the rotary shaft and the excavation blade, and a plurality of rows of excavation claws are provided in each step in the radial direction. An excavation head arranged and provided with a plurality of excavation claws in one row.   An excavator comprising a plurality of excavation shafts in which the excavation diameters of adjacent excavation shafts partially overlap each other and arranged by alternately shifting the tip positions of the excavation shafts, wherein the excavation head of the excavation shaft is located in front of the excavation direction. Excavator which is the described excavation head.

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