JP4767989B2 - Excavation shaft connection method and excavation shaft connection structure for ground improvement device - Google Patents

Description

  In the present invention, the excavation shaft is formed into a double tubular shape with an inner shaft and an outer shaft rotating in opposite directions, and the inner and outer shafts are formed by a plurality of inner and outer shaft structures connected vertically. Further, the present invention relates to a method for connecting excavation shafts and a structure thereof in a ground improvement device in which stirring blades are respectively formed on inner and outer shaft components at the lower end.

  Conventionally, for the purpose of strengthening soft ground or purifying contaminated ground, ground improvement agents (solidifying agents, purification agents, etc.) are discharged into the excavated soil while excavating the soil, and the ground improvement agent and soil are agitated. The ground is improved by mixing.

  In this ground improvement work, a dedicated ground improvement device is used (for example, refer to Patent Document 1). This ground improvement device attaches the base end of the excavation shaft to the rotary motor, forms a stirring blade for agitating the excavated soil at the tip of the excavation shaft, and discharges the ground improvement agent in the vicinity of the stirring blade The ground improver is discharged into the soil from the improver outlet, and the ground improver and the excavated soil are stirred and mixed by a stirring blade.

  In this ground improvement device, in order to perform agitation and mixing of the ground improvement agent and the soil, the excavation shaft is formed into a double tubular shape with an inner shaft and an outer shaft rotating in opposite directions. In addition, a type in which a stirring blade is formed at the lower end of each inner and outer shaft has been developed.

  Also, in the ground improvement device, in order to be able to excavate the ground deeply as needed, each inner and outer shaft can be formed by a plurality of inner and outer shaft constituents connected vertically, and the inner and outer shaft constituents can be added. What has been made possible is being developed.

JP 2005-139788 A

  However, in the above conventional ground improvement device in which the excavation shaft is formed into a double tubular shape with the inner and outer shafts, the inner shaft is accommodated inside the outer shaft, so when the inner shaft structure is added. It was difficult to smoothly connect the excavation shaft because the outer shaft structure was in the way.

  Therefore, in the conventional ground improvement device, a slide mechanism that slides the outer shaft constituent body up and down is provided at the connection portion between the rotary motor and the excavating shaft, and the outer shaft constituent body is displaced from the inner shaft constituent body by the slide mechanism. The thing which connected the excavation axis was developed.

  However, in this ground improvement device, since the slide mechanism is provided at the connection portion between the rotary motor and the excavation shaft, the excavation shaft connection work becomes a work at a high place, and there is a problem in safety. .

  In addition, in the conventional ground improvement device, the upper and lower inner shaft components are configured to be connected by connection pins, and through holes for allowing the connection pins to be inserted from the outside are formed in the outer shaft components, There has also been developed a structure in which the excavation shaft is connected by connecting the upper and lower inner and outer shaft components from outside the outer shaft component.

  However, in this ground improvement device, since the inner and outer shafts are configured to rotate independently in opposite directions, the inner shaft is loosely fitted inside the outer shaft, and the upper and lower inner and outer shafts are If the shaft constituent body is cut off, the lower inner shaft constituent body falls downward due to its own weight. In order to prevent this, the shaft body integrated with the inner and outer shafts with the bearing mechanism that restricts the vertical movement between the inner shaft and the outer shaft and is free to rotate between the agitating blade and the inner and outer shaft components. Provided. As a result, the inner shaft component does not fall due to its own weight, so that the addition work can be performed. However, the inner / outer shaft integrated type shaft body equipped with this bearing mechanism suffers from severe wear and wear of the bearing due to the influence of vibration during construction, etc. In addition, when performing replacement / repair work, it was necessary to dismantle the outer shaft portion and pull out the inner shaft portion, which was very laborious and expensive.

  As described above, in the conventional ground improvement device in which the excavation shaft is formed into a double tubular shape with the inner and outer shafts, it is difficult to safely and smoothly connect the excavation shaft by adding the inner and outer shaft components. It had the problem of being.

  Therefore, in the present invention according to claim 1, the excavation shaft is formed into a double tubular shape with the inner shaft and the outer shaft rotating in the opposite directions, and a plurality of the inner and outer shafts connected vertically. In the excavation shaft connecting method of the ground improvement device formed by the inner and outer shaft constituents and the stirring blades respectively formed on the inner and outer shaft constituents at the lower end, the inner shaft constituents of the outer shaft constituents are fixed to the outer shaft constituents fixed to the ground. It was decided to connect the upper and lower inner and outer shaft components in this state by connecting from the outside to regulate the vertical movement of the inner shaft member.

  Moreover, in this invention which concerns on Claim 2, in this invention which concerns on the said Claim 1, the through-hole formed in the outer-shaft structure body and the latching groove formed in the inner-shaft structure body are latched with a connection pin. Thus, the inner shaft constituent body is connected to the outer shaft constituent body from the outside of the outer shaft constituent body.

  According to a third aspect of the present invention, in the first aspect of the present invention, the outer shaft is formed by inserting a wedge between the upper outer peripheral surface of the inner shaft component and the upper inner peripheral surface of the outer shaft component. The inner shaft constituent body is connected to the shaft constituent body from the outside of the outer shaft constituent body.

  Further, in the present invention according to claim 4, the excavation shaft is formed into a double tubular shape with an inner shaft and an outer shaft rotating in opposite directions, and a plurality of inner and outer shafts are connected vertically. In the excavation shaft connection structure of the ground improvement device formed by the inner and outer shaft constituents and the stirring blades formed on the inner and outer shaft constituents at the lower end, the inner shaft constituents of the outer shaft constituents are fixed to the outer shaft constituents fixed to the ground. An inner / outer shaft constituent body connecting mechanism for restricting the vertical movement of the inner shaft constituent body by being connected from the outside is provided.

  Further, in the present invention according to claim 5, in the present invention according to claim 4, the inner / outer shaft constituent body coupling mechanism includes a through hole formed in the outer shaft constituent body and a locking formed in the inner shaft constituent body. The grooves and the connecting pins that lock the through holes and the locking grooves are used.

  Moreover, in this invention which concerns on Claim 6, in this invention which concerns on the said Claim 4, the said inner / outer shaft structure connection mechanism is the upper end outer peripheral surface of an inner shaft structure and the upper end inner peripheral surface of an outer shaft structure. I decided to make it with wedges that fit in between.

  And in this invention, there exists an effect described below.

  That is, in the present invention, the inner shaft constituent body is connected to the outer shaft constituent body fixed to the ground from the outside of the outer shaft constituent body to restrict the vertical movement of the inner shaft constituent body, and the upper and lower inner and outer shaft constituent bodies in this state are regulated. Therefore, it is possible to connect the excavation shaft safely in a low place, and it is not necessary to provide an inner / outer shaft integrated shaft body equipped with a bearing mechanism. Can be performed safely, inexpensively and smoothly.

  Below, the concrete structure of the ground improvement apparatus which concerns on this invention is demonstrated, referring drawings.

  As shown in FIG. 1, the ground improvement device 1 has a support column 3 standing at the front end of a heavy machine 2, and a drilling mechanism 4 is attached to the support column 3 so as to be movable up and down. An improving agent supply mechanism 59 comprising a water tank 6, an improving agent storage tank 7 and an improving agent discharge pump 8 is connected in communication via a swivel joint 9.

  The excavation mechanism 4 has a lifting support 10 attached to the front side of the support column 3 so that it can be moved up and down. A driving motor 11 and a reversing transmission 12 linked to the driving motor 11 are mounted on the lifting support 10. A base end portion of the excavation shaft 13 is linked to the transmission 12 and a stirring blade 14 is attached to the distal end portion of the excavation shaft 13.

  As shown in FIG. 2, the excavation shaft 13 is formed in a double tubular shape with a hollow cylindrical inner shaft 15 and an outer shaft 16 arranged coaxially, and the reversal transmission 12 includes an inner shaft 15 and an outer shaft. 16 are independently linked and linked so that the reverse transmission 12 causes the inner shaft 15 and the outer shaft 16 to rotate relatively in opposite directions. Specific structures of the inner shaft 15 and the outer shaft 16 will be described later.

  The stirring blade 14 includes a pair of left and right tip-side stirring blades 17 formed at the tip portion of the inner shaft 15, a pair of left and right innermost stirring blades 18 formed at the tip portion of the outer shaft 16, and a middle portion on the tip side of the inner shaft 15. A pair of left and right inner stirring blades 19 formed in a substantially U-shape at the center, and an outer stirring blade 20 formed in a substantially U-shape at an interval of 120 degrees in the circumferential direction at the front end side middle portion of the outer shaft 16 It is composed.

  Here, since the inner shaft 15 and the outer shaft 16 are rotated in the opposite directions relatively by the reverse transmission 12, the tip side stirring blade 17 and the inner stirring blade 19 formed on the inner shaft 15 are The innermost agitating blade 18 and the outer agitating blade 20 formed in 16 are rotated in a relatively opposite direction.

  The tip side agitating blade 17 is attached to the outer peripheral surface of the tip of the inner shaft 15 with a plate-like wing body 21 in an inclined manner, and a plurality of excavation bits 22 are attached to the lower end side portion of the wing body 21 at intervals. An improving agent discharge port 23 is formed above the wing body 21. The improver discharge port 23 communicates with the ground improver supply mechanism 8 through the hollow portion of the inner shaft 15.

  The innermost stirring blade 18 has a plate-like blade body 24 attached to the outer peripheral surface of the tip of the outer shaft 16 in an inclined manner.

  The inner stirring blade 19 has a lower end portion attached to the outer peripheral surface of the inner shaft 15 and an annular body 25 attached to the upper end portion, and the annular body 25 is loosely fitted to the outer peripheral surface of the outer shaft 16. The inner stirring blade 19 has plate-shaped small blade pieces 26, 27, and 28 attached to the outer surface, the inner surface, and the upper surface, respectively. Further, the inner stirring blade 19 has a connecting blade piece 29 attached to the inner shaft 15, and the improving agent discharge port 30 is formed in the connecting blade piece 29. The improver discharge port 30 communicates with the ground improver supply mechanism 8 through the hollow portion of the inner shaft 15.

  The outer stirring blade 20 has an upper end portion attached to the outer peripheral surface of the outer shaft 16 and an annular body 31 attached to the lower end portion, and the annular body 31 is loosely fitted to the outer peripheral surface of the inner shaft 15. The outer stirring blade 20 has plate-shaped small blade pieces 32 and 33 attached to the inner surface.

  The agitating blade 14 is attached to the tip of the excavation shaft 13 via a seal rod 34 so that earth and sand excavated by the seal rod 34 does not enter the excavation shaft 13.

  Next, a specific structure of the inner shaft 15 and the outer shaft 16 (excavation shaft 13), which is a main part of the present invention, will be described.

  The excavation shaft 13 has a configuration in which the inner shaft 15 is accommodated in a hollow portion of the outer shaft 16 so as to be rotatable and movable up and down, and the inner and outer shaft components 35 and 36 in which the inner and outer shafts 15 and 16 are connected vertically. It can be added.

  As shown in FIG. 3, the inner shaft constituting body 35 is formed with a hexagonal connection convex portion 37 in the cross-sectional view at the upper end portion, and on the left and right sides of the connection convex portion 37, a semicircular connection groove 38 in the cross-sectional view. On the other hand, a hexagonal hole-shaped connection recess 39 is formed in the lower end portion in cross-sectional view, and a semicircular arc-shaped connection hole 40 is formed in the outer peripheral surface of the connection recess 39 in a cross-sectional view in a penetrating manner. ing.

  The inner shaft 15 is inserted into the connecting concave portion 39 of the upper inner shaft constituting body 35 with the connecting convex portion 37 of the lower inner shaft constituting body 35 and connected with the connecting pin 41 inserted from the connecting hole 40. By engaging 38 and the connection hole 40, the upper and lower inner shaft components 35, 35 can be connected (see FIG. 4).

  The inner shaft constituting body 35 is formed with a locking groove 42 on the lower outer peripheral surface of the connecting convex portion 37.

  As shown in FIG. 3, the outer shaft constituting body 36 has spline shaft-like connection convex portions 43 formed at the upper end portion, and horizontal connection grooves 44 in the cross-sectional view are horizontally formed on the left and right side surfaces of the connection convex portion 43. On the other hand, a spline shaft hole-like connection recess 45 is formed at the lower end, and a connection hole 46 is formed in the connection recess 45 in a penetrating manner.

  The outer shaft 16 is inserted into the connecting concave portion 45 of the lower outer shaft constituting body 36 by the connecting convex portion 43 of the lower outer shaft constituting body 36 and connected by the connecting pin 47 inserted from the connecting hole 46. By locking 44 and the connection hole 46, the upper and lower outer shaft components 36, 36 can be connected (see FIG. 4).

  In the outer shaft constituting body 36, a through hole 48 is formed on the lower outer peripheral surface of the connecting convex portion 43 at a position facing the connecting groove 38 formed in the inner shaft constituting body 35, and the connecting convex portion 43 A vertically long through hole 49 is formed on the lower outer peripheral surface of the inner shaft constituting body 35 at a position facing the locking groove 42 formed in the inner shaft constituting body 35, and the lid bodies 50 and 51 can be freely attached to and detached from the insertion hole 48 and the through hole 49. Screwed on.

  Further, the outer shaft constituting body 36 is formed with a ring-shaped casing 52 on the outer peripheral surface of the middle portion.

  Thus, the excavation shaft 13 is formed with a through-hole 48 in the outer peripheral surface of the outer shaft constituting body 36 at a position facing the connection groove 38 formed in the inner shaft constituting body 35. The inner shaft 15 (inner shaft component 35) can be connected from the outside of 16 (outer shaft member 36).

  The excavation shaft 13 is inserted through the through-hole 49 because the through-hole 49 is formed on the outer peripheral surface of the outer shaft constituting body 36 at a position facing the locking groove 42 formed in the inner shaft constituting body 35. By locking the locking groove 42 and the through hole 49 with the connecting pin 53, the inner shaft component 35 is connected to the outer shaft component 36 from the outside of the outer shaft component 36 (excavation shaft 13). The vertical movement of the structure 35 can be regulated (see FIGS. 4 and 5).

  The ground improvement device 1 is configured as described above, and the excavation shaft 13 can be added as described below.

  When the excavation shaft 13 is added, the excavation shaft 13 is disconnected and then the excavation shaft 13 is connected.

  When the excavating shaft 13 is cut off, first, as shown in FIG. 4, the ground 54 is excavated between the housing 52 and the ground 54 of the outer shaft constituting body 36 while being buried in the ground. The outer shaft constituting body 36 is fixed to the ground 54 with a support plate 55 interposed therebetween.

  Next, the lids 50 and 51 are removed from the outer shaft constituting body 36, the insertion hole 48 and the through hole 49 are exposed, the connecting pin 53 is inserted from the through hole 49, and the inner pin constituting body 35 is engaged by the connecting pin 53. The stop groove 42 and the through hole 49 of the outer shaft component 36 are locked. At this time, the vertical position of the inner shaft constituting body 35 can be finely adjusted by driving the wedge 56 between the lower portion of the connecting pin 53 and the inner peripheral portion of the vertically long through hole 49. As a result, the inner shaft constituting body 35 is connected to the outer shaft constituting body 36 and the vertical movement is restricted.

  Next, the connection pin 47 is removed from the connection hole 46 of the outer shaft component 36, and the connection pin 41 of the inner shaft component 35 is removed from the insertion hole 48 of the outer shaft component 36. Thereby, the upper and lower inner and outer shaft constituting bodies 35 and 36 can be separated vertically. At this time, since the inner shaft component 35 is connected to the outer shaft component 36 fixed to the ground 54, it is possible to prevent the inner shaft component 35 from falling due to its own weight.

  When the excavation shaft 13 is connected, since it is in the state shown in FIG. 5 by the separation, it can be performed in the reverse procedure to the above-described separation.

  When the inner shaft component 35 can be lifted upward from the outer shaft component 36, as shown in FIG. 6, the upper end outer peripheral surface of the inner shaft component 35 and the upper inner periphery of the outer shaft component 36 are shown. By inserting wedges 57, 57 having a pair of left and right circular cross sections between the inner surface and the inner surface, the inner shaft constituent body 35 is connected to the outer shaft constituent body 36 by utilizing its own weight. The vertical movement of the shaft component 35 can be restricted, and in this state, the inner shaft component 35 and the outer shaft component 36 can be connected in order.

  In an actual construction site, as shown in FIG. 7, first, a drill bit 58 is attached to the lower end of the drilling shaft 13 to be added, and the drilling shaft 13 to be added at a predetermined position is buried (FIG. 7 (a)). After that, excavation to a predetermined depth (FIG. 7 (b)), and then the excavation shaft 13 is disconnected as described above, and the excavation shaft 13 embedded in a predetermined position is connected (FIG. 7 (c)). Then, the buried excavation shaft 13 is pulled out and the excavation bit 58 is removed, and the excavation shaft 13 is connected as described above (FIG. 7 (d)), and then excavated to a predetermined depth (FIG. 7 (e)). During excavation, the ground is excavated by the excavating bit 22 formed on the tip side stirring blade 17 of the excavating mechanism 4, and the ground improver is introduced into the soil together with the compressed air from the improver discharge ports 23 and 30 inside the ground. In addition, the ground is improved by mixing and stirring the soil and the ground improvement agent by the stirring blade 14.

  Further, as shown in FIG. 8, after excavating to a predetermined depth (FIG. 8 (a)), the excavating shaft 13 is pulled up to a predetermined height (FIG. 8 (b)), and then the excavating shaft as described above. 13 and the excavation bit 58 is attached to the tip, and the excavation shaft 13 is buried at a predetermined position (FIG. 8 (c)). Thereafter, the excavation shaft 13 is separated and the excavation shaft 13 previously separated is attached. Then, the excavation shaft 13 is pulled up to the ground (FIG. 8 (e)).

  As described above, in the ground improvement device 1, the inner shaft constituent body 35 is connected to the outer shaft constituent body 36 fixed to the ground 54 from the outside of the outer shaft constituent body 36 to move the inner shaft constituent body 35 up and down. In this state, the upper and lower inner and outer shaft components 35 and 36 are disconnected or connected.

  Therefore, in the ground improvement device 1, the excavation shaft 13 can be safely connected in a low place, and it is not necessary to provide an inner / outer shaft integrated shaft body having a bearing mechanism. Can be performed safely, inexpensively and smoothly.

BRIEF DESCRIPTION OF THE DRAWINGS Whole explanatory drawing which shows the ground improvement apparatus which concerns on this invention. The cross-sectional side view which shows a stirring blade. The side view (a) and sectional drawing (b) (c) which show an excavation axis. The side view (a) and sectional drawing (b) (c) which show the connection method of a digging shaft. The side view (a) and sectional drawing (b) (c) which show the connection method of a digging shaft. The side view (a) and sectional drawing (b) (c) which show the connection method of a digging shaft. Explanatory drawing which shows the connection operation | work of a digging shaft. Explanatory drawing which shows the connection operation | work of a digging shaft.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Ground improvement device 2 Heavy machine 3 Strut 4 Excavation mechanism 5 Improvement agent mixing plant 6 Water tank 7 Improvement agent storage tank 8 Improvement agent discharge pump 9 Swivel joint 10 Lifting support body
11 Drive motor 12 Reverse transmission
13 Drilling shaft 14 Stirring blade
15 Inner shaft 16 Outer shaft
17 Tip side stirring blade 18 Innermost stirring blade
19 Inner stirring blade 20 Outer stirring blade
21 Wings 22 Drilling bits
23 Improving agent outlet 24 Wing body
25 Annulus 26, 27, 28 Small winglet
29 Linkage blade 30 Improvement agent discharge port
31 Annulus 32,33 Small winglet
34 Seal rod 35 Inner shaft component
36 Outer shaft component 37 Connection projection
38 Connection groove 39 Connection recess
40 Connection hole 41 Connection pin
42 Locking groove 43 Convex protrusion
44 Connection groove 45 Connection recess
46 Connection hole 47 Connection pin
48 Insertion hole 49 Through hole
50,51 Lid 52 Enclosure
53 Connecting pin 54 Ground
55 Support plate 56 Wedge
57 wedge 58 drill bit
59 Improving agent supply mechanism

Claims (6)

The excavation shaft is formed into a double tubular shape with an inner shaft and an outer shaft that rotate in opposite directions, and each inner and outer shaft is formed by a plurality of inner and outer shaft components connected vertically, and the inner and outer ends of the lower end are formed. An excavation shaft connection method for a ground improvement device in which stirring blades are respectively formed on a shaft structure,
Outer shaft structure fixed to the ground in the inner shaft structure coupled externally of the outer shaft structure to restrict the vertical movement of the inner shaft structure, connecting the upper and lower inner and outer shaft structure, respectively in the state An excavation shaft connection method for a ground improvement device.   Connecting the inner shaft component to the outer shaft component from the outside of the outer shaft component by locking the through-hole formed in the outer shaft component and the locking groove formed in the inner shaft component with a connecting pin. The excavation shaft connecting method of the ground improvement device according to claim 1.   The inner shaft component is connected to the outer shaft component from the outside of the outer shaft component by inserting a wedge between the upper outer peripheral surface of the inner shaft component and the upper inner peripheral surface of the outer shaft component. The excavation shaft connection method of the ground improvement device according to claim 1. The excavation shaft is formed into a double tubular shape with an inner shaft and an outer shaft that rotate in opposite directions, and each inner and outer shaft is formed by a plurality of inner and outer shaft components connected vertically, and the inner and outer ends of the lower end are formed. Excavation shaft connection structure of a ground improvement device in which a stirring blade is formed on each of the shaft components,
Characterized by providing inner and outer shaft structure coupling mechanism for the outer shaft structure fixed to the ground in the inner shaft structure coupled externally of the outer shaft structure to restrict the vertical movement of the inner shaft structure The excavation shaft connection structure of the ground improvement device.   The inner / outer shaft constituent body coupling mechanism is constituted by a through hole formed in the outer shaft constituent body, a locking groove formed in the inner shaft constituent body, and a connecting pin for locking the through hole and the locking groove. The excavation shaft connection structure of the ground improvement device according to claim 4.   5. The ground improvement according to claim 4, wherein the inner / outer shaft constituent body coupling mechanism is configured by a wedge fitted between an upper end outer peripheral surface of the inner shaft constituent body and an upper end inner peripheral surface of the outer shaft constituent body. Equipment excavation shaft connection structure.

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