JPH0721621Y2 - Ground improvement device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention is intended to excavate and agitate the ground while rotating an inner shaft and a hollow outer shaft externally fitted to the inner shaft by a rotary drive device. The present invention relates to a ground improvement device.

(Prior Art and its Problems) As a conventional device of this type, there is one disclosed in Japanese Patent Laid-Open No. 59-15118. This device has an inner hollow excavating shaft with an excavating head attached to the tip and an outer hollow stirring shaft externally fitted with stirring blades on the outer periphery thereof, via a transmission gear by a common prime mover. While descending along the leader while rotating in the normal or reverse direction, the ground is excavated by the excavation head, and after reaching the predetermined depth, the cement milk supplied through the hollow part of the excavation shaft is raised while raising both the inner and outer shafts. Further, the cement milk and the excavated soil are jetted into the excavated soil and mixed and stirred by a stirring blade.

However, generally, in an apparatus for excavating the ground or penetrating into the ground while lowering the excavation axis and the casing along the leader, the excavation depth and the penetration depth in one step are limited to the effective length of the leader. When excavating or penetrating deeper than the effective length, it is necessary to extend the excavation shaft and casing by a predetermined length. However, in the case of a uniaxial excavating shaft or a single pipe casing, the excavating shaft or casing can be detached from the auger machine etc. while being excavated or penetrated to a predetermined depth in the ground and added. It is possible to easily add shafts and the like, but in the case of a device consisting of a double tube shaft in which the inner shaft and the outer shaft are driven to rotate, the work of adding to each shaft is not easy, In a device such as a conventional device that is rotationally driven by one common prime mover, it is extremely difficult or impossible to cut and splice (separate and add) each shaft.

In view of the above-mentioned problems, the present invention makes it possible to easily suspend the shafts in a device having a double pipe shaft including an inner shaft and an inner shaft for outer excavation.

(Means for Solving Problems) A ground improvement device of the present invention is an inner shaft driving device that rotationally drives an inner shaft, and an outer shaft driving device that rotationally drives a hollow outer shaft that is externally fitted to the inner shaft. Is installed so that it can be moved up and down along the leader,
The inner shaft and the outer shaft can be rotationally driven independently of each other, and the inner shaft and the inner shaft driving device and the outer shaft and the outer shaft driving device are arranged so as to be relatively movable in the axial direction, and the inner shaft and the outer shaft are arranged. Are each divided into an upper shaft member and a lower shaft member, which are detachably connected by a detachable pin, an excavation head is attached to the lower end of the lower shaft member of the inner shaft, and a stirring blade is attached to the outer periphery of the lower shaft member of the outer shaft. It is characterized by being attached.

(Operation) According to the ground improvement device of the present invention, the inner shaft and the outer shaft are effectively rotated by the inner shaft driving device and the outer shaft driving device while the upper and lower shaft parts are connected by the detachable pins. You can dig into the ground up to the length. When the depth of excavation is to be extended beyond the effective length of the leader, the attachment / detachment pin on the outer shaft side is first detached to release the connection between the upper shaft member and the lower shaft member of the outer shaft, By relatively moving the inner shaft drive device and the outer shaft and outer shaft drive device in the axial direction, the connecting end portions of the upper shaft member and the lower shaft member of the outer shaft facing each other can be properly lengthened in the axial direction. The inner shaft connecting portion where the upper shaft member and the lower shaft member are connected to each other by the detachable pin is exposed in the space. In such a state, after detaching the attachment / detachment pin to release the connection between the upper shaft member and the lower shaft member of the inner shaft, the expanding lower shaft members of both the inner and outer shafts are left as they are, and The upper shaft member is lifted, and the inner shaft adding shaft member having a required length is interposed between the upper shaft member of the inner shaft and the lower shaft member that is separated from the upper shaft member, and these shaft members are Are connected to each other by means of attachment / detachment pins, and then similarly, an outer shaft extension shaft member of a required length is interposed between the upper shaft member and the lower shaft member of the outer shaft, and those shaft members are mutually connected by the attachment / detachment pin. Connect to. When the addition of the inner shaft and the outer shaft is completed in this way, the inner shaft driving device and the outer shaft driving device rotate the inner shaft and the outer shaft again, and the ground is excavated by the length of the additional shaft member. .

As described above, according to the device of the present invention, it is possible to easily connect the additional shaft member to the inner shaft and the outer shaft.

(Embodiment) An embodiment will be described with reference to the drawings. FIG. 1 schematically shows the whole ground improvement device according to the present invention, in which a guide rail 3 of a leader 2 supported by a crawler crane 1 is provided. Is equipped with an inner shaft drive device 4 that can be moved up and down, and a hollow drilling shaft (inner shaft) with a drilling head 5 attached to the lower end.
6 and a hollow stirring shaft (outer shaft) 8 which is fitted on the outer peripheral surface of the lower end portion thereof and has a stirring blade 7 attached to the lower part of the outer shaft driving device 4, and is provided below the inner shaft driving device 4. Is mounted on the guide rail 3 of the outer shaft driving device 9 so as to be able to move up and down. These inner shaft driving device 4 and outer shaft driving device 9 are hung from the top of the reader 2 by separate wires (not shown). It is independently suspended so that it can be raised and lowered.

As shown in FIG. 2, the inner shaft driving device 4 is a housing.
In the housing 10, the upper end of the inner shaft 6 for excavation is supported by a bearing 11 so as to be rotatable but immovable in the axial direction.
The gear 13 fixed to the output shaft of the motor 12 is meshed with the gear 14 concentrically fixed to the inner shaft 6, and the inner shaft 6 for excavation is driven to rotate by the activation of the motor 12. Supporting cylinders 10a and 10b are connected to the lower part, and supporting cylinders 10c are connected to the upper part. The inner shaft 6 for excavation is divided into an upper shaft member 6a and a lower shaft member 6b at a position slightly below the position where the outer shaft drive 9 is provided, and is detachably connected by a detachable pin 15. As shown in FIGS. 2 and 4, the attachment / detachment pin 15 is provided on the outer peripheral surface of the support shaft portion 16 and the upper outer peripheral surface of the lower shaft member 6b which are integrally connected to the lower end portion of the upper shaft member 6a. It is fitted and inserted into the pin hole which is provided over the entire length. A cement milk supply pipe 17 is concentrically inserted into the excavating inner shaft 6, and an upper portion of the pipe 17 communicates with a cement milk supply port 18 via a swivel joint in the support cylinder 10c. The lower part communicates with the cement milk discharge port 19 of the drilling head 5. Cement milk is supplied to the supply port 18 by the pump P ₁ . Although illustration is omitted, it is assumed that the cement milk supply pipe 17 is also detachably connected at the lower part of the connecting portion of the vertical shaft members 6a and 6b.

The agitating outer shaft 8 is also divided into an upper shaft member 8a and a lower shaft member 8b slightly below an outer shaft driving device 9 for rotationally driving the stirring shaft 8. As shown in FIGS. The upper end of the upper shaft member 8a is connected to the bearings 21a and 21b in the support cylinder 10b at the lower part of the inner shaft drive device 4 by being detachably connected by 20.
Is held so as to be rotatable and slidable in the axial direction for a required stroke. The outer shaft driving device 9 has a housing 22 in which the upper shaft member 8a of the stirring outer shaft 8 is rotatably supported by a bearing 23 so as to be immovable in the axial direction. The fixed gear 25 is meshed with the gear 26 that is concentrically fixed to the upper shaft 8a, and the motor 24
The outer shaft 8 for stirring is rotationally driven by the activation of. The housing 10 of the inner shaft 6 for excavation and the housing 22 of the outer shaft 8 for stirring are slidably supported by the guide rails 3 of the reader 2, and these housings 10, 22 are respectively hung from the top of the reader 2 by a wire. I have it.

Further, as shown in FIG. 2, the lower shaft member 8b of the outer stirring shaft 8 is
The outer peripheral side stopper piece 27 of the leader shape is attached to the inner peripheral surface of the lower end of the
A ring-shaped inner shaft side stopper 28 is fixed to the lower shaft member 6b of the excavating inner shaft 6 below the outer shaft side stopper piece 27 on the outer peripheral surface of the lower end portion thereof. The gap 29 between the agitating outer shaft 8 and the excavating inner shaft 6 is located below the inner shaft driving device 4 via the communication holes 30 and 30 and the swivel joint 31 formed in the excavating inner shaft 6. Is communicated with the pressure fluid supply port 32 provided in the supporting cylinder portion 10a of the above, and the pressure fluid is supplied from the water pressure pump P ₂ or the air pump P ₃ to the above-mentioned gap portion 29 via the three-way switching valve 33, whereby the gap portion The pressure of 29 is increased to prevent cement milk or the like from entering the gap 29 between the outer peripheral surface of the inner shaft stopper piece 28 and the inner peripheral surface of the lower shaft member 8b of the outer shaft 8. .

A guide member 34 for holding and guiding the outer shaft 8 is provided below the leader 2.

In the use of the ground improvement device having the above-mentioned configuration, when the depth of the ground to be improved does not exceed the effective length of the leader 2, the two shafts are changed from the state shown in FIG.
If the ground is excavated while unwinding the wires that respectively suspend 6 and 8 while rotating both shafts 6 and 8 in the opposite directions, or by rotating only the excavation shaft 6, if the predetermined depth is reached. For example, both shafts 6 and 8 are raised, the rotational speeds of both shafts 6 and 8 are switched to high speed, and the shafts 6 and 8 are repeatedly moved up and down repeatedly to mix and mix cement milk and excavated soil uniformly. To do. During this time, the pressure fluid is supplied into the gap 29 at a pressure slightly higher than the earth pressure to prevent cement milk or the like from entering the gap 29.

When the depth of excavation of the ground is to be deeper than the effective length of the leader 2, the both shafts 6 and 8 are lowered and rotated as described above, and the ground is dug to near the effective length limit of the leader 2. At that point, the excavation of both shafts 6 and 8 is stopped. Then, first, the attachment / detachment pin 20 is pulled out to release the connection between the upper shaft member 8a and the lower shaft member 8b of the stirring outer shaft 8, and the outer shaft driving device 9 is pulled up by a wire so that the upper end portion of the upper shaft member 8a becomes the inner shaft. Drive unit 4
The lower shaft support member 8b is in a state of being embedded in the ground, but is lowered to some extent by its own weight, and the stopper piece 27 is locked to the inner shaft side stopper piece 28. The state shown in FIG. 5 is obtained. by this,
As is apparent from FIG. 5, the upper shaft member 8a of the stirring outer shaft 8
And the connecting end portions of the lower shaft member 8b which face each other are vertically separated from each other by an appropriate length, and the connecting portion of the excavating inner shaft 6 which is connected by the attachment / detachment pin 15 is exposed in the space S thereof. Become.
Then, in this state, the detachable pin 15 of the excavating inner shaft 6 is pulled out, and the upper shaft member 6a and the lower shaft member 6b are disconnected, and then the inner shaft driving device 4 and the outer shaft driving device 9 are wired. The upper shaft member 6a of the inner shaft 6 for excavation and the upper shaft member 8a of the outer shaft 8 for stirring which are integrally united with these devices 4 and 9 are raised to a required height, and then the inner shaft 6 for excavation is Between the upper shaft member 6a and the lower shaft member 6b which is separated from the upper shaft member 6a, a supplementary shaft member (not shown) for the inner shaft 6 having a required length is inserted and arranged while being held by a wire or the like, The upper and lower ends of the replenishing shaft member are connected to the upper shaft member 6a and the lower shaft member 6b, respectively, by attachment / detachment pins. A cement milk supply pipe is also inserted and supported in the shaft of the replenishing shaft member for the inner shaft 6 by a required length, and the upper and lower ends of the pipe are connected to the vertical shaft members 6a and 6b. The cement milk supply pipes in 6a and 6b are ready to be connected. When the work of adding the inner shaft 6 for excavation is completed in this way, a connecting shaft member for the outer shaft 8 having a required length is provided between the upper shaft member 8a and the lower shaft member 8b of the stirring outer shaft 8 (shown in the figure. (Omitted) is inserted in the same manner as above, and the additional shaft member is connected to the upper shaft member 8a and the lower shaft member 8b by a detachable pin. When the work of adding the stirring outer shaft 8 is completed, the inner shaft driving device 4
Then, the outer shaft drive device 9 is restarted, and the inner shaft 6 for excavation and the outer shaft 8 for stirring are rotated downward while further excavating the ground.

In the embodiment described above, the connecting portion between the upper and lower shaft members 6a and 6b in the inner shaft 6 for excavation is located slightly above the connecting portion between the upper and lower shaft members 8a and 8b in the outer stirring shaft 8. Therefore, after the upper shaft member 8a and the lower shaft member 8b of the stirring outer shaft 8 are separated, the outer shaft driving device 9 is attached to the stirring outer shaft 8.
The upper shaft member 8a is slid upward together with the upper shaft member 8a. However, for example, when the connecting portion of the inner shaft 6 for excavation is provided at a position slightly higher than the connecting portion of the outer shaft 8 for stirring, The upper shaft member 8a and the lower shaft member 8b of the outer shaft 8 are separated, the lower shaft member 8b is slightly lowered by its own weight to separate the shaft members 8a, 8b from each other by a required distance, and then the inner shaft driving device 4 is excavated. The inner shaft 6 is slid downward together with the upper shaft member 6a so that the connecting portion of the inner shaft 6 for excavation faces the space between the vertical shaft members 8a and 8b of the outer shaft 8 for stirring.

Further, in the embodiment, the outer shaft driving device 9 is mounted on the upper shaft member 8a of the stirring outer shaft 8, but it may be mounted on the lower shaft member 8b.

Further, in the embodiment, the inner shaft 6 is a hollow shaft, and the cement milk supply pipe is inserted therein. However, in the present invention, the cement milk supply pipe is not essential, and therefore the inner shaft 6 is solid. It may be an axis.

(Effect of the Invention) According to the ground improvement device of the present invention, after excavating the ground by the inner shaft and the outer shaft to the effective length of the leader, when the excavation depth is further deepened, the addition work of the inner shaft and the outer shaft is added. Can be done easily. That is, when replenishing both the inner and outer shafts, the attachment / detachment pin for connecting the outer shaft is detached to release the connection between the upper and lower shaft members of the outer shaft, and the inner shaft and the inner shaft drive device and the outer shaft and the outer shaft drive device are connected. By relatively moving in the axial direction, the upper and lower shaft members of the outer shaft are separated by an appropriate length in the axial direction,
If the connecting portion of the inner shaft is made to face the space portion, the detaching operation of the inner shaft connecting attachment / detachment pin becomes possible. Therefore, the connecting shaft member can be connected to the inner shaft and the connecting shaft member can be connected to the outer shaft. It can be done easily.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an overall schematic side view of a ground improvement device showing an embodiment of the present invention, FIG. 2 is a detailed vertical sectional view of the same device, and FIG. 3 is III of FIG. -III line enlarged sectional view, Fig. 4 is Fig. 2 IV-
IV line enlarged sectional view, FIG. 5 is a longitudinal sectional view showing a state in which the upper shaft member and the lower shaft member of the outer shaft are separated. 2 ... Leader, 4 ... Inner shaft drive device, 5 ... Cutter, 6 ... Excavation inner shaft (inner shaft), 6a ... Inner shaft upper shaft member, 6b ... Inner shaft lower shaft member, 7 ... Stirring blade, 8 ... stirring outer shaft, 8a ... outer shaft upper shaft member, 8b ... outer shaft lower shaft member, 9 ... outer shaft drive device,
15… Removable pin for inner shaft connection, 20… Removable pin for outer shaft connection.

Claims (1)

[Scope of utility model registration request] 1. An inner shaft driving device for rotating an inner shaft, and an outer shaft driving device for rotating a hollow outer shaft externally fitted to the inner shaft so as to be vertically movable along a reader. The outer shaft and the outer shaft can be rotationally driven independently of each other, and the inner shaft and the inner shaft drive device and the outer shaft and the outer shaft drive device are arranged so as to be relatively movable in the axial direction, and the inner shaft and the outer shaft are respectively upper parts. The shaft member and the lower shaft member were divided and connected by a detachable pin so that they could be separated from each other, and an excavation head was attached to the lower end of the lower shaft member of the inner shaft, and a stirring blade was attached to the outer periphery of the lower shaft member of the outer shaft. A soil improvement device.