JP2003106082A - Extensive excavation jig for driving foundation pile - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an excavation jig for driving a foundation pile, which can extend the diameter of excavation in a large amount without incurring rapid and severe resistance from the ground at the time of excavation. SOLUTION: According to the extensive excavation jig, an excavating shaft 3 is spline-connected to a driving shaft 2 in a manner being relatively displaceable in the vertical direction. Then, an upper end of an extended blade 4 is connected to the driving shaft 2 in a vertically rotatable manner, and a lower end of the extended blade 4 is connected to an upper end of an auxiliary link 12 in a vertically rotatable manner, followed by connecting a lower end of the auxiliary link 12 to the excavating shaft 3 in a vertically rotatable manner. Further, a cutter 8 for extensive excavation is attached to the extended blade 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an excavating jig for foundation pile construction, which has an expanding blade for expanding the diameter to form a root-consolidating bulb portion in a medium excavation method.

[0002]

2. Description of the Related Art In the medium excavation method, the following method has been proposed as a method for forming a root-hardening bulb. This method uses a device in which a tip of a spiral screw has an excavating blade for shaft excavation at the tip and a drilling jig having an expanding blade mechanism is attached to the tip. Then, the spiral screw to which the excavating jig is attached is inserted into the hollow pile and the rotary torque is transmitted to the excavating jig to perform the intermediate excavation. Then, after the pile is sunk to a predetermined depth, the expansion blade is expanded in diameter, and subsequently the ground at the tip of the pile is expanded and excavated by the blade for expansion and excavation attached to the expansion blade to consolidate the root space. To form. After that, cement milk is sprayed into the excavated bulb space, and the root consolidating bulb is built by stirring and mixing with the earth and sand by rotating the expanding blades or the like.

A conventional mechanism for expanding and reducing the diameter of the expanding blade is disclosed in, for example, Japanese Patent Application Laid-Open No. 11-62452. That is, as shown in FIG.
An expanding blade 52 is horizontally rotatably attached to a support shaft 51 that is eccentric from the rotary shaft 50 of the excavating jig and extends vertically.

When the excavating jig is rotated normally (to the right), the tip of the blade of the expanding blade 52 is located on the rotary shaft 50 side and is in a reduced diameter state (see FIG. 21 (a)). As a result, they are arranged in a circle having a diameter smaller than the inner diameter of the pile and can pass through the inside of the pile. On the other hand, when the excavating jig is rotated in the reverse direction, the tip of the blade provided on the expanding blade 52 bites into the ground, and the expanding blade 52 is in a state of being forcibly expanded at a stretch (see FIG. 21 (b)). Expanded excavation is possible.

[0005]

However, in the above-mentioned expanding wing mechanism, when the expanding wing 52 expands in a horizontal plane,
Since it is a mechanism that forcibly opens (expands) at a stretch by using the reaction force that cuts into the ground, there is a problem that a large resistance from the ground is suddenly received. In particular, since the support layer for expanding and excavating is hard, this problem becomes remarkable.

Further, in the prior art, since it is a mechanism system for reducing and expanding the expanding blade 52 in a horizontal plane, considering that it is necessary to reduce the diameter until it can pass through the pile. However, there is also a problem that the amount of diameter expansion is limited. This causes a problem that the size of the bulb root fixing portion related to the bearing capacity of the pile is limited. The present invention has been made in view of the above problems, and excavation for foundation pile construction capable of setting a large diameter expansion amount while preventing a sudden resistance from the ground at the time of diameter expansion. The challenge is to provide jigs.

[0007]

In order to solve the above-mentioned problems, the invention described in claim 1 of the present invention is a drive shaft, an excavation shaft splined to the drive shaft, and a tip of the excavation shaft. An excavating jig for foundation pile construction, comprising: a shaft excavating blade provided on the shaft, and an expanding blade that is supported by the drive shaft and the excavating shaft and is capable of expanding in diameter and to which an expanding excavating blade is attached. The drive shaft and the excavating shaft are spline-coupled so as to be relatively displaceable in the vertical direction, and the upper end portion of the expanding blade is rotatably connected to the drive shaft in the vertical direction, and the lower end of the expanding blade is Or an intermediate position in the extending direction is vertically rotatably connected to an upper end of the auxiliary link, and a lower end of the auxiliary link is vertically rotatably connected to the excavation shaft. It is a thing.

According to the present invention, the drive shaft and the excavating shaft are vertically displaced relative to each other, whereby the upper end portion of the expanding blade and the lower end portion of the auxiliary link move away from each other or come close to each other. The expanded blade expands in the upward direction and contracts in the downward direction. In this way, since the expanding blades are expanded in the vertical direction to expand and contract the diameter, it is possible to set the expanding amount larger than in the conventional case.

Next, the invention described in claim 2 is provided with a rotating member which is supported on the excavating shaft in a state capable of being rotationally displaced about the axis of the excavating shaft, and the rotating member has the above-mentioned rotating member. The lower end portion of the auxiliary link is connected so as to be vertically rotatable. According to the present invention, when the drive shaft is displaced relative to the excavation shaft in the vertical direction, even if rotational displacement occurs in the circumferential direction, the rotating member is absorbed by being rotationally displaced with respect to the drive shaft, and the auxiliary It is possible to prevent an unnecessary unnecessary torque from being input to the link and the expanding blade.

If the upper end of the expanding blade is supported by the drive shaft via the rotating member as described above, it becomes impossible to transmit the rotational torque from the drive shaft to the expanding blade. Next, the invention described in claim 3 is the same as claim 1 or claim 2.
In contrast to the configuration described in (1), the auxiliary link is arranged so as to cross the rotation axes of the drive shaft and the excavation shaft in a side view.

According to the present invention, since the arm for moment when opening the expanding blade is earned, the expanding blade can be easily opened. next,
The invention described in claim 4 is a drive shaft, an excavation shaft spline-coupled to the drive shaft so as to be relatively displaceable in the vertical direction, a shaft excavating blade provided at the tip of the excavation shaft, and the drive shaft. On the other hand, the upper end portion is rotatably connected in the vertical direction so that the diameter can be expanded, and the enlarged blade to which the enlarged excavating blade is attached, and the upward protruding from the excavation shaft toward the lower surface of the enlarged blade, The present invention provides an excavating jig for performing foundation piles, the guide bar having an upper end abutting against a lower surface of the expanding blade and guiding a diameter expansion of the expanding blade.

According to the present invention, when the distance between the excavation shaft and the drive shaft approaches, the expansion blade attached to the drive shaft also moves to the excavation shaft side. Since the attached guide bar abuts, the downward movement of the expanding blade is restricted, and as a result, the expanding blade expands in diameter. Next, in the invention described in claim 5, in contrast to the structure described in any one of claims 1 to 4, at least an upper portion of the excavation shaft constitutes a tubular portion made of a tubular body, and the tubular portion The lower part of the drive shaft is coaxially inserted into the inside of the portion, and a vertically extending key groove is formed on one of the inner diameter surface of the excavation shaft or the outer diameter surface of the drive shaft, and the inner diameter surface of the excavation shaft or the drive shaft is formed. A key protruding toward the key groove is formed on the other of the outer diameter surfaces of the key groove, and a part of the key groove in the extending direction has a wide groove width and has an abutting surface vertically facing the key. It is characterized by forming a part.

According to the present invention, the drive shaft and the excavation shaft can be relatively displaced in the vertical direction by extending the key groove in the vertical direction. In addition, since a part of the key groove is wide and has an abutting surface that vertically opposes the key, when the key abuts on the abutting surface at the position of the wide portion, the vertical load is applied to the drive shaft and the excavating shaft. It is possible to prevent the key from moving upwards or downwards even if it is loaded on the valve, that is, to stop the expansion or contraction of the expanding blade at that position. That is, it is possible to regulate unnecessary expansion of the expanding blades.

Next, in the invention described in claim 6, in addition to the structure described in claim 5, the key is provided on the outer diameter surface of the drive shaft, and the key groove is provided on the inner diameter surface of the tubular portion. The wide portion has a groove width that is wide on the side wall side of the key groove against which the key is pressed when the drive shaft rotates in the forward direction at a position facing the key when the expanding blade is in a reduced diameter state, and the protrusion is formed. It is characterized in that the contact surface faces upward.

Here, the normal rotation direction means a rotation direction at the time of digging the shaft, and generally means right rotation. According to the present invention, since the key provided on the drive shaft faces the abutting surface from the upper side in the state of normal rotation for shaft digging,
Even if a downward force is applied to the drive shaft at the time of digging the shaft, the abutting surface prevents the key from moving downward and prevents the expanding blade from expanding.

Next, in the invention described in claim 7, in addition to the structure described in claim 5, the key is provided on the inner diameter surface of the tubular portion, and the key groove is provided on the outer diameter surface of the drive shaft. The wide portion has a groove width that is wide on the side wall side of the key groove against which the key is pressed when the drive shaft rotates in the forward direction at a position facing the key when the expanding blade is in a reduced diameter state, and the protrusion is formed. It is characterized in that the contact surface faces downward.

According to the present invention, since the key provided on the excavating shaft faces the abutting surface from the lower side in the state of normal rotation for excavating the shaft, the key faces downward with respect to the drive shaft at the time of excavating the shaft. Even if a force is applied, the abutting surface prevents the key from moving upward and prevents the expanding blade from expanding. Next, in the invention described in claim 8, in addition to the structure described in any one of claims 1 to 4, at least a lower portion of the drive shaft constitutes a tubular portion made of a tubular body, and the tubular portion The upper part of the excavation shaft is coaxially inserted into the part from below, and a vertically extending key groove is formed on one of the inner diameter surface of the drive shaft or the outer diameter surface of the excavation shaft, and the inner diameter surface of the drive shaft or the excavation shaft is formed. A key that protrudes toward the key groove is formed on the other outer diameter surface of the shaft, and a part of the key groove in the extending direction has an abutting surface that widens the groove width and vertically opposes the key. It is characterized in that a wide portion is formed.

According to the present invention, the drive shaft and the excavation shaft can be relatively displaced in the vertical direction by extending the key groove in the vertical direction. In addition, since a part of the key groove is wide and has an abutting surface that vertically opposes the key, when the key abuts on the abutting surface at the position of the wide portion, the vertical load is applied to the drive shaft and the excavating shaft. It is possible to prevent the key from moving upwards or downwards even if it is loaded on the valve, that is, to stop the expansion or contraction of the expanding blade at that position. That is, it is possible to regulate unnecessary expansion of the expanding blades.

Next, in the invention described in claim 9, in contrast to the structure described in claim 8, the key is provided on the outer diameter surface of the excavation shaft and the key groove is provided on the inner diameter surface of the tubular portion. The wide portion has a groove width that is wide on the side wall side of the key groove against which the key is pressed when the drive shaft rotates in the forward direction at a position facing the key when the expanding blade is in a reduced diameter state, and the protrusion is formed. It is characterized in that the contact surface faces downward.

According to the present invention, since the key provided on the drive shaft faces the abutting surface from the lower side in the state of normal rotation for shaft digging, the key is directed downward with respect to the drive shaft during shaft digging. Even if a force is applied, the abutting surface prevents the key from moving upward and prevents the expanding blade from expanding. Next, the invention described in claim 10 is different from the structure described in claim 8, in that the key is provided on the inner diameter surface of the tubular portion and the key groove is provided on the outer diameter surface of the excavating shaft, and the wide portion is provided. Is that the groove width is wide on the side wall side of the key groove against which the key is pressed when the drive shaft is positively rotated at the position facing the key when the expanding blade is in the reduced diameter state, and the abutting surface is It is characterized by facing upward.

According to the present invention, since the key provided on the drive shaft faces the abutting surface from the lower side in the state of normal rotation for the shaft digging, the key faces downward with respect to the drive shaft during the shaft digging. Even if a force is applied, the abutting surface prevents the key from moving upward and prevents the expanding blade from expanding. Next, the invention described in claim 11 is different from the structure described in any one of claims 5 to 10.
The key groove extends vertically in a spiral shape, and the extending direction is
The guide shaft is set so as to be guided upward as it goes in the forward rotation direction of the drive shaft.

According to the present invention, the extending direction (guide direction) of the key groove is inclined so as to be displaced upward in the forward rotation direction. For this reason, when the drive shaft is rotated in the reverse direction and enlarged excavation is performed, when the torque is transmitted from the drive shaft to the excavation shaft through the key, when the key is provided on the drive shaft, the side wall of the key groove is formed. Since there is a downward component force in the reaction force from the key, it is easy for the key to be displaced downward along the keyway, and when the key is provided on the excavation shaft, the key from the side wall of the keyway Since the reaction force has an upward component, the key is likely to be displaced upward along the key groove.

In the case where the key groove extends along the axial direction, the drive shaft is relatively displaced downward with respect to the excavation shaft only by applying a force for pressing the drive shaft downward. Is possible. The expansion wings open due to this relative displacement, but since the expansion wings are in the ground,
When opening it receives more resistance than the ground. Therefore, the pressing force for relatively displacing the drive shaft downward becomes large, and a large pressing means is required. If the key groove extends vertically in a spiral shape, rotating the drive shaft will generate propulsive force on the drive shaft. Therefore, even if the pressing force on the drive shaft is small, the drive shaft should be rotated. The expansion wings can be opened by.

Next, in the invention described in claim 12, in contrast to the structure described in claim 11, the inclination angle of the key groove is
It is characterized in that the tilt angle is set to a range of 10 degrees or more with respect to the axis. The key can be effectively displaced in the vertical direction by defining the inclination angle of the key groove.

If the inclination angle is less than 10 degrees, the vertical component of the reaction force generated when the key is pressed against the side wall of the key groove is small, and the drive shaft is rotated. Efficient drive shaft propulsion does not occur. Therefore, the inclination angle of the key groove is preferably 10 degrees or more with respect to the axis. There is no particular upper limit to the inclination angle of the key groove, but if the inclination angle is 90 degrees with respect to the axis, the key groove does not spirally extend in the vertical direction, so the inclination angle is less than 90 degrees with respect to the axis. Needless to say.

Next, the invention described in claim 13 is different from the structure described in any one of claims 1 to 12 in that the expanding blade is driven with respect to the excavation shaft when the expanded blade is in the expanded state. It is characterized in that a lock mechanism for restricting relative displacement of the shaft upward is provided. According to the present invention, the lock mechanism restricts the drive shaft from being relatively displaced upward with respect to the excavation shaft in a state where the expansion blade is expanded in diameter. Is regulated.

Next, the invention described in claim 14 is different from the structure described in claim 13, in that the lock mechanism projects downward from the projection provided on the excavation shaft and the drive shaft, and It is characterized by comprising a hook-shaped member having a hooking portion which can face the protrusion from below. According to the present invention, when the drive shaft is relatively displaced upward with respect to the excavation shaft, the hooking portion abuts the protrusion from the lower side, and further displacement is restricted.

Next, in the invention described in claim 15, in contrast to the structure described in claim 13, the lock mechanism is provided with a protrusion provided on the drive shaft, and the lock mechanism protrudes upward from the excavation shaft and It is characterized by comprising a hook-shaped member having a hooking portion which can face the protrusion from above. According to the present invention, when the drive shaft is relatively displaced upward with respect to the excavation shaft, the hooking portion abuts the protrusion from the lower side, and further displacement is restricted.

Next, in the invention described in claim 16, in contrast to the structure described in claim 13, the lock mechanism has a drive shaft for a key groove facing the key when the expanding blade is in the expanded state. Is formed by a second wide portion having a wide groove width on the side wall side of the key groove against which the key is pressed when the key rotates in the reverse direction. According to the present invention, the key is moved into the second wide portion by the torque during the reverse rotation, and the abutting surface of the second wide portion is in contact with the key at least during the reverse rotation, The expansion wing restricts the displacement in the diameter reducing direction and locks it.

[0030]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the present invention will be described with reference to the drawings. 1 and 2 are views showing an excavating jig K attached to the tip of an auger screw 1 according to the present embodiment, and a drive shaft 2 to which a rotational torque is transmitted from the auger screw 1, and the drive shaft 2 And an excavation shaft 3 which is spline-coupled to and co-rotates with the drive shaft 2. Note that FIG. 2 shows a state in which the expansion blade 4 described later is expanded to the maximum diameter.

From the tip of the excavation shaft 3, a straight blade 5 is formed downward.
And a plurality of blades 7 are attached to the excavation blade 6 to form a shaft excavation blade. The drive shaft 2 is
It is composed of a tubular body, and the upper portion of the excavation shaft 3 is coaxially inserted into the drive shaft 2 of the tubular body. Further, the drive shaft 2 and the excavation shaft 3 are spline-coupled so as to be relatively displaceable in the vertical direction. The excavation shaft 3 is also composed of a cylindrical body.

Explaining the structure of the spline connection, as shown in FIG. 3, a key 11 having a rhombic shape in plan view protrudes from the inner diameter surface of the drive shaft 2 in the inner diameter direction, and the outer diameter surface of the excavation shaft 3 has the above-mentioned structure. Keyway 1 for guiding the key 11 up and down
0 is formed. FIG. 4 is a partially enlarged view of the key groove 10 as seen from the outer diameter side in a state of being developed in the circumferential direction.
As shown in (a), it extends obliquely with respect to the axis P of the excavation shaft 3 by a predetermined angle θ, that is, extends vertically along the inner diameter surface of the excavation shaft 3. Key groove 1 above
The inclination direction of 0 is set so as to be displaced upward as the excavation shaft 3 rotates in the direction of normal rotation.

The inclination angle θ of the key groove 10 is set to about 20 degrees with respect to the axis P, for example. The keyway 10
The width of the lower part 10B is about twice the width of the key 11, but the upper part 10A constitutes a wide part.
The groove width is set to about 3 times the width of the key 11, and the upper portion 10
At the boundary between A and the lower portion 10B, there is a step portion that forms a horizontal surface (abutting surface 10a) that can face the lower end portion of the key 11 from the lower side. The stepped portion is widened to the left side when viewed from the outer diameter side in a state where the enlarged blade is reduced in diameter, that is, to the left side wall 10b side where the key 11 is pressed when the drive shaft 2 rotates in the forward direction, and the stepped portion of the upper portion 10A. Right side wall 10c and lower part 10
There is no step between the right side wall 10c of B.

Further, the upper end of the expanding blade 4 is attached to the outer diameter surface of the drive shaft 2 so as to be rotatable only in the vertical direction, and a blade 8 for expanding excavation is attached to the expanding blade 4. . The upper end of the auxiliary link 12 is rotatably connected to the lower end of the expansion wing 4 in the vertical direction, and the lower end of the auxiliary link 12 is rotatably connected to the excavation shaft 3 only in the vertical direction. There is.

In the figure, the expanding wing 4 and the auxiliary link 1 are shown.
Although only one set consisting of two is shown, only a plurality of sets are provided in axial symmetry. Further, as shown in FIG. 2, the support shaft 1 protruding in the outer diameter direction is provided on the outer diameter surface of the excavation shaft 3.
3, a swing member 14 is swingably attached to the support shaft 13. The swinging member 14 extends downward. The support shaft 13 and the swinging member 14 form a protrusion.

A hook-shaped member 15 extending downward is provided at the lower end of the drive shaft 2. A tip portion of the hook-shaped member 15 extends rightward in a side view to form a hooking portion 15a that can face the swinging member 14 in the vertical direction. The relationship between the protrusion and the hook-shaped member 15 is such that when the expanding blade 4 is expanded to the maximum diameter, the hooking portion 15a of the hook-shaped member 15 contacts the lower end of the swinging member 14 from below. Designed in position.

When the expanding blade 4 is expanded to the maximum diameter, the lower end surface of the drive shaft 2 comes into contact with the excavation shaft 3,
Further, the drive shaft 2 is provided with an abutment portion 3a for restricting relative movement downward, that is, the expansion blade 4 moving further upward. Here, reference numeral 16 is an injection hole for cement milk, and as shown in FIG. 6, it communicates with a pipe passage 17 extending vertically inside the excavation shaft 3 and the drive shaft 2, and the pipe passage 17
The cement milk can be injected through the injection hole 16 through. The upper portion of the pipe passage is inserted into an insertion passage in a plug 18 attached to the upper end of the drive shaft 2.

Next, the operation and effects of the excavating jig K having the above structure will be described. In the state where the auger screw 1 is suspended and inserted into the pile, that is, when the excavation jig K is suspended, the drive shaft 2 is displaced upward with respect to the excavation shaft 3, and the expansion blade 4 swivels downward. The diameter has been reduced. In this state, the key 11 provided on the drive shaft 2
Located on the upper portion 10A of the keyway 10 (see FIG. 4 (a))
To do. The vertical movement range of the key 11 with respect to the key groove 10 is restricted by the abutting portion 3a, the expanding blade 4, and the auxiliary link 12.

Then, the excavation jig is suspended,
The expansion blade 4 is inserted into the pile in a reduced diameter state. Next, when the rotational torque is transmitted to the drive shaft 2 and the shaft is dug, the key 11 rotates to the left (normal rotation) as shown in FIG. By being pressed against the side wall 10b on the left side of 10, the torque is transmitted from the drive shaft 2 to the excavation shaft 3 via the key 11 and the side wall 10b, the excavation shaft 3 rotates, and the shaft excavation shaft 3 is rotated. The ground is excavated with a blade. At this time, in order to proceed with the excavation downward, an external force downward is applied to the drive shaft 2 from above, and an upward external force is applied to the excavation shaft 3 as a reaction force from the ground, so that the key 11 Is the keyway 1
Although the key 11 tries to move downward along 0, the key 11 comes into contact with the horizontal surface (abutting surface 10a) of the step portion, so that the key 11 is prevented from moving downward, that is, the expanding blade 4 expands in diameter. To be prevented. This enables axial excavation along the inside of the pile even if the enlarged excavation mechanism is provided.

After the axial digging in the pile to the tip of the pile is completed as described above, subsequently, the enlarged digging for the bulb fixing portion is performed. The expanded excavation is performed as follows. First, the drive shaft 2 is rotated in the opposite direction. As a result, the key 11 moves to the right in the circumferential direction and contacts the side wall 10c on the right side of the key groove 10 when viewed from the outer diameter direction, as shown in FIG.

Then, by applying a downward load to the drive shaft 2 while rotating in the reverse direction, the key 11 is pressed against the right side wall 10c of the key groove 10 as shown in FIG. Displace downwards along. As described above, as the key moves to the right side wall 10c of the keyway 10, the excavation shaft 3 is relatively displaced upward with respect to the drive shaft, and the expansion blade 4 gradually rotates upward and expands in diameter.

At this time, since the key groove 10 is inclined in the reverse rotation direction of the drive shaft 2 and extends spirally, the key 1
An external force that acts downward from the side wall of the key groove 10 acts on the key 11 by the reaction force when the key 1 is pressed against the right side wall 10c of the key groove 10. Even when the pressure is large, the key 11 is likely to move downward along the right side wall 10c of the key groove 10, that is, the expanding blade 4 is likely to open.

Further, since the diameter of the expanding blade 4 is expanded by rotating it up and down, the maximum diameter of the expanding blade 4 at the time of expanding the diameter can be increased even if the expanded blade 4 can be reduced in diameter to be smaller than the pile inner diameter. You can Further, as the key moves downward, the hook-shaped member 15 approaches the swinging member 14 from the upper side, and
Since the keyway 10 extends so as to move downward as the keyway 10 rotates in the reverse direction, when the drive shaft 2 is rotationally displaced leftward with respect to the excavation shaft 3 and expanded to the maximum diameter, the hook-shaped member 15 is formed.
As shown in (a) → (b) of FIG. 7, the locking portion 15a approaches the swinging member 14 from the left side and latches on the swinging member 14 from below.

FIG. 8 shows a plan view of the expanded blade 4 when the diameter thereof is expanded. Subsequently, while continuing the reverse rotation (counterclockwise rotation), pulling upward and expanding excavation upward. At this time, the rocking member 14 and the hook-shaped member 15 prevent the excavation shaft 3 from being displaced downward with respect to the drive shaft 2, that is, the expanding blade 4 can be held in the expanded state.

Next, when the above-mentioned expanded excavation is completed and a space for root consolidation is formed, cement milk is injected into the space through the injection hole 16. At this time, while rotating in reverse,
The excavation shaft 3 is vertically reciprocated to perform stirring. At this time, since the excavating jig K is moved up and down while rotating in the reverse direction, the key 11 is pressed against the right side wall 10c of the key groove 10 and the expansion blade 4 is prevented from being reduced in diameter by the lock mechanism.

Next, by rotating the drive shaft 2 clockwise, as shown in FIG. 7 (b) → (a), the hook-shaped member 15 is formed.
Is disengaged from the swing member 14. When the key 11 is pulled upward from that state, the key 11 moves upward along the key groove 10, and as a result, the expanding blade 4 is in a reduced diameter state and can pass through the pile. Here, in the above embodiment, the case where the excavation shaft 3 is coaxially inserted into the drive shaft 2 has been described, but the present invention is not limited to this. The drive shaft 2 may be coaxially inserted into the excavation shaft 3 from above. In this case, for example, the key 11 is provided on the outer diameter surface of the drive shaft 2 and the key groove 10 is formed on the inner diameter surface of the excavation shaft 3. Even in this case,
The shape of the key groove 10 provided on the excavation shaft 3 may be such that the wide portion is formed on the upper side and is inclined so as to be displaced to the upper side in the forward rotation direction, similarly to the above description.

Further, the bracket 9 for attaching the lower end of the auxiliary link to the excavation shaft 3 so as to be vertically rotatable may be attached so as to be rotationally displaceable with respect to the excavation shaft 3. When the drive shaft 2 is reversely rotated or the key 11 is moved up and down along the key groove 10, the drive shaft 2 is rotationally displaced relative to the excavation shaft 3, but the rotational displacement is caused by the bracket. Since 9 absorbs, it is possible to prevent the twisting torque more than required from being generated in the auxiliary link 12 and the expanding blade 4.

In the above embodiment, the case where the protrusion of the lock mechanism is provided on the excavation shaft 3 and the hook-shaped member 15 is provided on the drive shaft 2 is shown as an example, but the present invention is not limited to this. For example, the projection is provided on the drive shaft 2, the hook-shaped member 15 is provided on the excavation shaft 3,
The hook-shaped member 15 may be set so as to extend upward from the excavation shaft 3. Further, in the above-described embodiment, the protrusion and the hook-shaped member 15 that form the lock mechanism are provided on the outer diameter side, but the present invention is not limited to this. For example, a swinging member may be swingably provided on a support shaft projecting from the inner diameter surface of the excavation shaft 3 in the inner diameter direction, and the hook-shaped member may be projected downward from the inner diameter surface of the drive shaft 2.

The lock mechanism is not limited to the above construction. For example, the lock mechanism may be configured by the second wide portion shown in the third embodiment described later. Next, a second embodiment according to the present invention will be described with reference to the drawings. The same members as those in the above embodiment will be described with the same reference numerals. The basic configuration of the present invention is the same as that of the first embodiment, but the spline mechanism is different.

That is, as shown in FIG. 9, a key 11 is provided on the outer diameter surface of the excavation shaft 3 and the key groove 1 is formed on the inner diameter surface of the drive shaft 2.
0 is set. The key groove 10 is a partially enlarged view of the key groove 10 as seen from the outer diameter side in a state of being developed in the circumferential direction.
As shown in FIG. 5, the digging shaft 3 extends in an oblique direction inclined by a predetermined angle with respect to the axis of the digging shaft 3, that is, extends vertically along the inner diameter surface of the digging shaft 3. The inclination direction of the key groove 10 is set so as to be displaced upward as the excavation shaft 3 rotates in the direction of normal rotation.

The inclination angle of the key groove 10 is set to about 20 degrees with respect to the axis. The width of the key groove 10 is about twice the width of the key 11 in the upper portion 10A, but the lower portion 10B forms a wide portion and is about three times the width of the key 11. The width is set, and at the boundary between the lower portion 10B and the upper portion 10A, there is a step portion that forms a horizontal surface (abutting surface 10a) that can face the upper end portion of the key 11 from the upper side. The stepped portion is widened to the right side as viewed from the outer diameter side, that is, to the right side wall 10c side against which the key 11 is pressed when the drive shaft 2 rotates in the forward direction, and the left side wall 10b and the lower side portion 10B of the upper side portion 10A. There is no step between the left side wall 10b and the left side wall 10b.

Next, the operation and effects of the excavating jig K having the above construction will be described. In the state where the auger screw 1 is suspended and inserted into the pile, that is, when the excavation jig K is suspended, the drive shaft 2 is displaced upward with respect to the excavation shaft 3, and the expansion blade 4 swivels upward. The diameter has been reduced. In this state, the key 11 provided on the drive shaft 2
It is located in the lower portion 10B of the keyway 10. The vertical position of the key 11 is restricted by the expanding blade 4 and the auxiliary link 12.

Then, the excavation jig is suspended,
The expansion blade 4 is inserted into the pile in a reduced diameter state. Next, when the rotational torque is transmitted to the drive shaft 2 and the shaft is dug, the key 11 rotates to the left (normal rotation) as shown in FIG. By being pressed against the side wall 10c on the right side of 10, the torque is transmitted from the drive shaft 2 to the excavation shaft 3 via the key 11 and the side wall, the excavation shaft 3 rotates, and the cutting tool for shaft excavation described above. The ground is excavated by. At this time, an external force downward is applied to the drive shaft 2 from above in order to advance the excavation downward, and an upward external force is applied to the excavation shaft 3 as a reaction force from the ground, so that the key 11 is The key 11 tries to move upward along the key groove 10, but the key 11 comes into contact with the horizontal surface (abutting surface 10a) of the step portion to prevent downward movement, that is, the expanding blade 4 expands in diameter. Is prevented. This enables axial excavation along the inside of the pile even if the enlarged excavation mechanism is provided.

After the axial excavation in the pile is completed up to the tip of the pile as described above, subsequently, enlarged excavation for the bulb fixing portion is performed. The expanded excavation is performed as follows. First, the drive shaft 2 is rotated in the opposite direction. As a result, the key 11 is, as shown in FIG.
It moves to the right in the circumferential direction and contacts the side wall 10b on the left side when viewed from the outer diameter direction of the key groove 10.

Then, by applying a downward load to the drive shaft 2 while rotating in the reverse direction, the key 11 is pressed against the left side wall 10b of the key groove 10 as shown in FIG. Displace upwards along. as mentioned above,
As the key moves to the left side wall 10b of the keyway 10,
The expanding wings gradually rotate upward and expand in diameter.

At this time, since the key groove 10 is inclined in the reverse rotation direction of the drive shaft 2 and extends spirally, the key 1
The reaction force generated when 1 is pressed against the left side wall 10b of the key groove 10 causes an external force to move upward from the side wall of the key groove 10 to the key 11, so that the key 11 and the left side wall 10b of the key groove 10 are Even if the pressure between the two is large, the key 11 is likely to move upward along the left side wall 10b of the key groove 10, that is, the excavation shaft 3 is likely to be relatively displaced upward with respect to the drive shaft 2, and the expansion blade is expanded. 4 becomes easier to open.

Further, since the diameter of the expanding blade 4 is expanded by rotating it up and down, the maximum diameter of the expanding blade 4 at the time of expanding the diameter can be increased even if the expanded blade 4 can be reduced in diameter to be smaller than the pile inner diameter. You can Further, as the key 11 moves upward, the hook-shaped member 15 approaches the swinging member 14 from the upper side, and extends so as to move downward as the key groove 10 rotates in the reverse direction. On the other hand, when the drive shaft 2 is rotationally displaced leftward and expanded to the maximum diameter, the hook-shaped member 15 approaches the swinging member 14 from the left side, as shown in FIGS. Then, the hooking portion 15a is attached to the swinging member 14
Hang from below.

Then, while continuing the reverse rotation (counterclockwise rotation), pulling upward and expanding excavation upward. At this time,
The rocking member 14 and the hook-shaped member 15 prevent the excavation shaft 3 from being displaced downward with respect to the drive shaft 2, that is, the expanding blade 4 can be held in the expanded state. Next, when the above-mentioned enlarged excavation is completed and a space for root consolidation is formed, cement milk is injected from the injection hole 16 into the space. At this time, the excavation shaft 3 is reciprocally moved up and down while rotating in the reverse direction to perform stirring.

At this time, since the excavating jig K is moved up and down while rotating in the reverse direction, the key 11 is pressed against the left side wall 10b of the key groove 10 and the expansion blade 4 is prevented from being reduced in diameter by the lock mechanism. It Next, the hook 11 is removed from the swinging member 14 by positively rotating the drive shaft 2 and then pulled upward, so that the key 11 moves downward along the key groove 10. The expanded wings 4 are reduced in diameter and can pass through the pile.

Here, in the above embodiment, the case where the excavation shaft 3 is coaxially inserted into the drive shaft 2 has been described, but the present invention is not limited to this. The drive shaft 2 may be coaxially inserted into the excavation shaft 3 from above. In this case, for example, the key 11 is provided on the inner diameter surface of the excavation shaft 3 and the key groove 10 is formed on the outer diameter surface of the drive shaft 2. Even in this case,
The shape of the key groove 10 provided on the drive shaft 2 may be formed such that the wide portion is formed on the lower side and is displaced so as to be displaced upward as it goes in the forward rotation direction, as in the case described above.

Other configurations, operations and effects are the same as those in the first embodiment. Next, a third embodiment will be described with reference to the drawings. It should be noted that parts similar to those in each of the above-described embodiments will be described with the same reference numerals. Book Third
The basic configuration of the embodiment is the same as that of the first embodiment. That is, as shown in FIGS. 11, 12, and 13, the drive shaft 2 to which the rotational torque is transmitted from the auger screw 1 and the drive shaft 2 that is spline-coupled to the drive shaft 2.
And an excavation shaft 3 that rotates together with the excavation shaft 3. Note that FIG.
Represents the state when the expansion blade 4 described later is expanded to the maximum diameter.

The tip of the excavation shaft 3 is provided with a straight blade 5 and a shaft excavation blade 6 to which a plurality of blades 7 are attached, which constitutes a shaft excavation blade. The drive shaft 2 is composed of a tubular body, and the upper portion of the excavation shaft 3 is coaxially inserted into the drive shaft 2. Further, the drive shaft 2 and the excavation shaft 3 are spline-coupled so as to be relatively displaceable in the vertical direction. The excavation shaft 3 is also composed of a cylindrical body.

The structure of the spline connection in the third embodiment will be described. As in FIG. 3, the key 1 having a rectangular shape in plan view from the inner diameter surface of the drive shaft 2 in the inner diameter direction.
A key groove 10 for guiding the key 11 up and down is formed on the outer diameter surface of the excavation shaft 3. As shown in FIG. 14 (b), which is a partially enlarged view of the key groove 10 when it is expanded in the circumferential direction from the outer diameter side, it extends vertically in parallel with the axis P of the excavation shaft 3. It is set.

The width of the key groove 10 is the central portion 10C.
Is approximately the same size as the width of the key 11, but the upper portion 10A constitutes the first wide portion and is set to have a groove width which is about twice the width of the key 11, and the upper portion 10A and the central portion. At the boundary with 10C, a step portion is formed at the lower end of the key 11 to form a horizontal surface (abutting surface 10a) that can be opposed from below. The stepped portion is widened to the left side as viewed from the outer diameter side in a state where the enlarged blade 4 is reduced in diameter, that is, to the left side wall 10b side against which the key 11 is pressed when the drive shaft 2 rotates forward.

Further, the lower portion 10B of the key groove 10
Constitutes a second wide portion (lock mechanism) and is set to have a groove width which is about twice the width of the key 11. At the boundary between the lower part 10B and the central part 10C, Has a step portion that forms a horizontal surface (abutting surface 10d) that can face each other. The stepped portion is on the right side as viewed from the outer diameter side with the expanded blade 4 expanded, that is, when the drive shaft 2 rotates in the reverse direction.
Is widened to the right side wall where is pressed.

Further, the upper end of the expansion blade 4 is attached to the outer diameter surface of the drive shaft 2 so as to be rotatable only in the vertical direction, and the blade 8 for expansion excavation is attached to the expansion blade 4. . An upper end portion of the auxiliary link 12 is rotatably connected in a vertical direction to a position near the lower end portion in the extending direction of the expansion blade 4, and the lower end portion of the auxiliary link 12 is only vertically connected to the excavation shaft 3. It is rotatably connected.

Here, reference numeral 21 is a member that reinforces and protects the mounting portion of the expanding blade 4 to the drive shaft. Further, in the present embodiment, the blade 8 is also provided on the lower surface side of the expanding blade 4. When the expansion blade 4 expands to the maximum diameter, the lower end surface of the drive shaft 2 comes into contact with the upper end of the excavation shaft 3, and the drive shaft 2 moves downward relative to the expansion blade 4, that is, the expansion blade 4. Is further provided with an abutting portion for restricting upward movement.

Next, the operation and effects of the excavating jig K having the above structure will be described. In the state where the auger screw 1 is suspended and inserted into the pile, that is, when the excavation jig K is suspended, the drive shaft 2 is displaced upward with respect to the excavation shaft 3 and the expansion blade 4 swivels downward. The diameter has been reduced. In this state, the key 11 provided on the drive shaft 2
It is located in the upper portion 10A of the keyway 10. The vertical movement range of the key 11 with respect to the key groove 10 is restricted by the contact portion, the expanding blade 4, and the auxiliary link 12.

The excavating jig is suspended,
The expansion blade 4 is inserted into the pile in a reduced diameter state. Then, when the rotational torque is transmitted to the drive shaft 2 and the shaft is dug, the key 11 rotates to the left (normal rotation) as shown in FIG. By being pressed against the side wall 10b on the left side of 10, the torque is transmitted from the drive shaft 2 to the excavation shaft 3 via the key 11 and the side wall 10b, the excavation shaft 3 rotates, and the shaft excavation shaft 3 is rotated. The ground is excavated by the blades 5 and 7. At this time, in order to proceed with the excavation downward, an external force downward is applied to the drive shaft 2 from above, and an upward external force is applied to the excavation shaft 3 as a reaction force from the ground, so that the key 11 Tries to move downwards along the keyway 10, but the key 11
By contacting the horizontal surface (abutting surface 10a) of the step, the downward movement is prevented, that is, the expansion blade 4 is prevented from expanding in diameter. This enables axial excavation along the inside of the pile even if the enlarged excavation mechanism is provided.

After the axial excavation in the pile is completed up to the tip of the pile as described above, subsequently, enlarged excavation for the bulb fixing portion is performed. The expanded excavation is performed as follows. First, the drive shaft 2 is rotated in the opposite direction. As a result, the key 11 is, as shown in FIG.
It moves to the right in the circumferential direction and contacts the right side wall 10c when viewed from the outer diameter direction of the key groove 10.

Then, by applying a downward load to the drive shaft 2 while rotating in the reverse direction, as shown in FIG.
Is pressed against the right side wall 10c of the keyway 10,
It is gradually displaced downward along the right side wall 10c. Here, since the excavation shaft 3 is rotating in the reverse direction, the excavation of the ground by the shaft excavating blade (straight blade 5, blade 7) is not substantially performed.
Therefore, since the pressure acting between the key 11 and the right side wall 10c of the key groove 10 is not so large, the key 11
Is movable downward along the right side wall 10c. However, similarly to the first embodiment, the key groove 10 may be formed in a spiral shape so that it can be moved more easily.

As described above, as the key moves to the right side wall 10c of the key groove 10, the excavation shaft 3 is relatively displaced upward with respect to the drive shaft 2, and the expansion blade 4 is gradually rotated upward. Expand the diameter. Then, as shown in FIG. 17, when the diameter expansion of the expansion blade 4 is completed, the key moves to the right as viewed from the outer shape direction and enters the step portion of the second wide portion as shown in FIG. The upward movement is restricted by the surface 10d.

At this time, since the excavation shaft 3 does not move downward (does not excavate), the drive shaft 2 moves downward in synchronism with the upward rotation of the expansion wing 4, and therefore, as shown in FIG. Like the locus, the tip (lower end) of the expanding blade 4 moves (excavates) substantially horizontally. That is, the expansion wing 4
Since the amount of excavation for expanding the diameter of the expansion blade 4 is small, the work amount for expanding the diameter of the expansion blade 4 is efficient. Further, even in the above-mentioned excavation for expanding the diameter, the expanding blade 4 gradually expands into the ground according to the contraction amount of the drive shaft 2 with respect to the excavating shaft 3, so that the expanding blade 4 can be surely expanded in diameter even if the ground is hard. .

Further, since the diameter of the expanding blade 4 is expanded by rotating it up and down, the maximum diameter of the expanding blade 4 at the time of expanding the diameter can be increased even if the expanded blade 4 can be reduced in diameter to be smaller than the inner diameter of the pile. You can Subsequently, while continuing the reverse rotation (counterclockwise rotation), pulling upward and expanding excavation upward. At this time,
The excavation shaft 3 is prevented from being displaced downward with respect to the drive shaft 2 by contacting the abutting surface of the second widened portion with the key, that is, the expanded blade 4 can be held in the expanded state.

Next, when the above-mentioned enlarged excavation is completed and a space for root consolidation is formed, cement milk is injected from the injection hole 16 into the space. At this time, while rotating in reverse,
The excavation shaft 3 is vertically reciprocated to perform stirring. At this time, since the excavating jig K is moved up and down while rotating in the reverse direction, the key 11 is pressed against the right side wall 10c of the key groove 10 and the expansion blade 4 is prevented from being reduced in diameter by the lock mechanism.

Next, by rotating the drive shaft 2 clockwise, the key 11 is moved to the state shown in FIGS.
If the key 11 is moved upward along the keyway 10 due to the weight of the excavation shaft 3 when pulled upward from that state, the enlarged blade 4 is in a reduced diameter state and can pass through the pile. . Here, in the above embodiment, the case where the excavation shaft 3 is coaxially inserted into the drive shaft 2 has been described, but the present invention is not limited to this. The drive shaft 2 may be coaxially inserted into the excavation shaft 3 from above. In this case,
For example, a key 11 is provided on the outer diameter surface of the drive shaft 2,
The key groove 10 is formed on the inner diameter surface of the. Even in this case, the shape of the key groove 10 provided on the excavation shaft 3 is the same as that described above.

The lower end of the auxiliary link 12 is connected to the excavation shaft 3
The bracket 9 is attached to the excavator shaft 3 so as to be vertically rotatable.
Alternatively, it may be attached so that it can be rotationally displaced. When the drive shaft 2 is reversely rotated or the key 11 is moved up and down along the key groove 10, the drive shaft 2 is rotationally displaced relative to the excavation shaft 3, but the rotational displacement is caused by the bracket. 9
Is absorbed, it is possible to prevent the twisting torque more than necessary from being generated in the auxiliary link 12 and the expanding blade 4.

Next, a fourth embodiment will be described with reference to the drawings. The same members as those in each of the above-described embodiments will be described with the same reference numerals. As shown in FIGS. 19 and 20, the basic configuration of the present embodiment is the third
Similar to the embodiment, except that a guide bar 20 is provided instead of the auxiliary link 12.

That is, the guide bar 20 is fixed to the outer diameter surface of the excavation shaft 3. The guide bar 20 includes the expansion wings 4
Is arranged at a position where it can face the lower surface of the expanding blade 4 in the vertical direction, and the upper end portion thereof can come into contact with the lower surface of the expanding blade 4. The contact position is as described above in a state where the tip of the expanding blade 4 is located inside the tip of the excavating blade 6 for shaft digging in a diameter-reduced state in which the key is located at the step of the first wide portion. The tip portion of the guide bar 20 is set so as to contact the lower surface of the expansion blade 4.

The position of the lower surface of the enlarged blade 4 with which the tip of the guide bar 20 can abut is in the extending direction so that the abutting portion of the guide bar 20 can slide along the extending direction. A contour shape such as a straight line shape or an arc shape along which there is no great change in curvature along the extending direction is set. Also, in the figure,
Although the guide bar 20 is shown only for one expansion wing 4, the guide bar 20 is provided for each expansion wing 4.

Next, the operation and effect of the excavating jig K having the above-mentioned structure will be described. In the state where the auger screw 1 is suspended and inserted into the pile, that is, when the excavation jig K is suspended, the drive shaft 2 is displaced upward with respect to the excavation shaft 3 and the expansion blade 4 swivels downward. The diameter has been reduced. Then, the excavating jig K is suspended and inserted into the pile with the expanded blade 4 in a reduced diameter state.

Then, even if the rotary torque is transmitted to the drive shaft 2 and the shaft is excavated, the space between the excavation shaft 3 and the drive shaft 2 is not contracted as described above. There is nothing to do. As a result, it becomes possible to perform axial excavation along the inside of the pile even if the expansion excavation mechanism is provided. After the axial digging inside the pile to the tip of the pile is completed as described above, the drive shaft 2 is then rotated in the opposite direction in order to perform the enlarged digging for the bulb root fixing part. The distance from the drive shaft 2 is gradually reduced, and the expansion blade 4 also approaches the excavation shaft 3 in accordance with the contraction, but since the guide bar 20 is in contact with the expansion blade 4 below the expansion blade 4, Rotate relatively upward to expand the diameter. That is, as shown in FIG. 20, as the drive shaft 2 is displaced downward relative to the excavation shaft 3, the contact position of the guide bar 20 moves to the inner diameter side, so that the expanding blade 4 expands in diameter. .

Subsequently, while continuing the reverse rotation (counterclockwise rotation), pulling upward and expanding the excavation upward. At this time,
The excavation shaft 3 is prevented from being displaced downward with respect to the drive shaft 2 by the key 11 coming into contact with the abutting surface 10d of the second widened portion, that is, the expanded blade 4 can be held in the expanded state. . Next, when the above-mentioned expanded excavation is completed and a space for root consolidation is formed, cement milk is injected into the space. At this time, the excavation shaft 3 is rotated while rotating in the reverse direction.
Is reciprocally moved up and down to perform stirring.

At this time, since the excavating jig K is moved up and down while being rotated in the reverse direction, the key 11 is pressed against the right side wall 10c of the key groove 10 and the expansion blade 4 is prevented from being reduced in diameter by the lock mechanism. It Next, when the drive shaft 2 is rotated clockwise and pulled up from that state, the drive shaft 2 is displaced relatively upward with respect to the excavation shaft 3 to return to the state of FIG. 4 is in a reduced diameter state and can pass through the pile.

Other operational effects are similar to those of the third embodiment. Here, in the present embodiment, since the upper end portion of the guide bar 20 is only in contact with the lower surface of the expansion blade 4,
There may be a gap between the guide bar 20 and the enlarged blade 4. In order to prevent this, a guide means may be provided to attach the upper end of the guide bar 20 to the lower surface of the expansion wing 4 so that the upper end of the guide bar 20 can move only in the extending direction of the expansion wing 4.

[0086]

As described above, by adopting the present invention, it is possible to set the diameter expansion of the expanding blade to be large, and it is possible to avoid receiving a sudden resistance from the ground when the expanding blade is expanded.

[Brief description of drawings]

FIG. 1 is a side view showing an excavating jig according to a first embodiment of the present invention.

FIG. 2 is a side view showing the excavating jig according to the first embodiment of the present invention.

FIG. 3 is a sectional view showing a spline connection according to the first embodiment of the present invention.

FIG. 4 is a cross-sectional view showing the spline connection according to the first embodiment of the present invention as seen from the outer diameter direction, in which (a) shows a state when the diameter is reduced, (b) shows a shaft digging, and (c) shows Reverse rotation is shown respectively.

5A and 5B are cross-sectional views showing the spline connection according to the first embodiment of the present invention as viewed from the outer diameter direction, FIG. 5D shows a state when the diameter is expanded, and FIG.

FIG. 6 is a sectional view showing an excavating jig according to the first embodiment of the present invention.

7A and 7B are views showing a lock mechanism according to the first embodiment of the present invention, in which FIG. 7A shows a state immediately before locking, and FIG. 7B shows a locked state.

FIG. 8 is a plan view showing a state in which the expanding blade according to the first embodiment of the present invention has an expanded diameter.

FIG. 9 is a sectional view showing a spline connection according to a second embodiment of the present invention.

FIG. 10 is a diagram showing a spline connection according to a second embodiment of the present invention as viewed from the outside, wherein (a) is for axial digging, (b) is for reverse rotation, and (c) is for enlargement. When completed,
(D) shows the unlocked state respectively.

FIG. 11 is a view showing an excavating jig according to a third embodiment of the present invention, in which (a) is a plan view and (b) is a side view.

FIG. 12 is a side view showing an excavating jig according to a third embodiment of the present invention.

FIG. 13 is a side view showing an excavating jig according to a third embodiment of the present invention.

14A and 14B are diagrams illustrating a state at the time of shaft digging according to the third embodiment of the present invention, in which FIG. 14A is a plan view and FIG.
[Fig. 6] is a view showing a spline connection as viewed from the outer diameter direction.

FIG. 15 is a view for explaining a state at the time of transition from axial digging to diameter expansion according to the third embodiment of the present invention,
Is a plan view and (b) is a view showing the spline coupling as viewed from the outer diameter direction.

FIG. 16 is a view showing a spline connection for explaining a state at the time of expanding the diameter according to the third embodiment of the present invention, as viewed from the outer diameter direction.

FIG. 17 is a diagram illustrating a state immediately before the completion of the diameter expansion according to the third embodiment of the present invention, in which (a) is a plan view;
(B) is the figure which showed the spline connection seen from the outer diameter direction.

FIG. 18 is a view for explaining a state during enlarged digging according to the third embodiment of the present invention, in which (a) is a plan view,
(B) is the figure which showed the spline connection seen from the outer diameter direction.

FIG. 19 is a diagram showing an excavating jig according to a fourth embodiment of the present invention, in which (a) is a plan view and (b) is a side view.

FIG. 20 is a view showing an excavating jig according to a fourth embodiment of the present invention, in which (a) is a plan view and (b) is a side view.

FIG. 21 is a view showing a conventional expansion blade, in which (a) shows a diameter reduction time and (b) shows a diameter expansion time.

[Explanation of symbols]

1 auger screw 2 drive shaft 3 excavation axis 4 expansion wings 5 Straight blade (cutting tool for shaft digging) 6 excavation wings 7 cutlery (cutting tool for shaft digging) 8 blades (enlargement excavation blades) 9 bracket 10 keyway 10A upper part 10B lower part 10C central part 10a abutting surface 10b left side wall 10c right side wall 10d abutting surface 11 keys 12 Auxiliary link 13 Supporting axis 14 Swing member 15 Hook-shaped member 15a Hook part 16 injection holes 17 pipelines 18 plugs 20 Guide bar P axis θ inclination angle

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Yasushi Wakiya             2-3-2 Uchisaiwaicho, Chiyoda-ku, Tokyo             Saki Steel Co., Ltd. (72) Inventor Yuichi Tatsumi             2-3-2 Uchisaiwaicho, Chiyoda-ku, Tokyo             Saki Steel Co., Ltd. (72) Inventor Hachiro Inoue             4-12-9 Hokuei Stock Exchange, Urayasu City, Chiba Prefecture             Company Tokyo Works (72) Inventor Kazuo Fukuda             3 Noza, 223 Shinko, Mihama-ku, Chiba-shi, Chiba             Ki Kenko Co., Ltd. F-term (reference) 2D029 EB03 PA02                 2D041 AA02 BA13 CA03 FA03                 2D050 CA02 CB03 CB09

Claims (16)

[Claims] 1. A drive shaft, an excavation shaft that is spline-coupled to the drive shaft, a shaft excavating blade provided at the tip of the excavation shaft, and a diameter that is supported by the drive shaft and the excavation shaft so that the diameter can be increased. A digging jig for foundation pile construction comprising a wing with an enlarged digging blade attached thereto, wherein the drive shaft and the digging shaft are spline-coupled in a vertically displaceable manner, The upper end of the expanding wing is vertically rotatably connected to the drive shaft, and the lower end of the expanding wing or an intermediate position in the extending direction is vertically rotatably connected to the upper end of the auxiliary link. An excavating jig for foundation pile construction, wherein a lower end portion of the auxiliary link is connected to the excavating shaft so as to be rotatable in a vertical direction. 2. A rotating member that is supported with respect to the excavation shaft in a state capable of being rotationally displaced about the axis of the excavation shaft, and the lower end portion of the auxiliary link rotates vertically in the rotating member. The excavating jig for constructing a foundation pile according to claim 1, wherein the excavating jig is movably connected. 3. The foundation pile construction according to claim 1 or 2, wherein the auxiliary link is arranged so as to intersect the rotation axes of the drive shaft and the excavation shaft in a side view. Drilling jig. 4. A drive shaft, an excavation shaft spline-coupled to the drive shaft so as to be vertically displaceable relative to each other, a shaft excavating blade provided at a tip end of the excavation shaft, and an upper end portion with respect to the drive shaft. Is rotatably connected in the vertical direction so that the diameter can be expanded, and an enlarged blade to which a blade for enlarged excavation is attached; and an upper end portion that protrudes upward from the excavation shaft toward the lower surface of the enlarged blade. An excavating jig for performing foundation piles, comprising: a guide bar that abuts a lower surface of a blade and guides the expansion of the expanded blade. 5. At least an upper portion of the excavation shaft constitutes a tubular portion made of a tubular body, and a lower portion of the drive shaft is coaxially inserted into the tubular portion from an upper side, and an inner diameter surface of the excavation shaft or a drive shaft is formed. A key groove extending vertically is formed on one of the outer diameter surfaces, and a key protruding toward the key groove is formed on the other of the inner diameter surface of the excavating shaft or the outer diameter surface of the drive shaft. The foundation pile according to any one of claims 1 to 4, wherein a part of the extending direction forms a wide portion having a widened groove width and an abutting surface that vertically opposes the key. Excavation jig for construction. 6. The key is provided on the outer diameter surface of the drive shaft, and the key groove is provided on the inner diameter surface of the tubular portion, and the wide portion opposes the key when the expanding blade is in a reduced diameter state. The base according to claim 5, wherein a groove width is widened toward a side wall side of the key groove against which the key is pressed when the drive shaft is normally rotated at the position, and the abutting surface is directed upward. Excavation jig for pile construction. 7. The key is provided on the inner diameter surface of the tubular portion, and the key groove is provided on the outer diameter surface of the drive shaft, and the wide portion opposes the key when the expanding blade is in the reduced diameter state. 6. The foundation according to claim 5, wherein a groove width is widened on a side wall side of a key groove against which a key is pressed when the drive shaft is normally rotated at the position, and the abutting surface faces downward. Excavation jig for pile construction. 8. At least a lower portion of the drive shaft constitutes a tubular portion made of a tubular body, and an upper portion of the excavation shaft is coaxially inserted from the lower side into the tubular portion, and an inner diameter surface of the drive shaft or the excavation shaft is formed. A key groove extending vertically is formed on one of the outer diameter surfaces of the shaft, and a key protruding toward the key groove is formed on the other of the inner diameter surface of the drive shaft or the outer diameter surface of the excavating shaft. 5. The base according to any one of claims 1 to 4, wherein a part of the extending direction of the groove has a wide groove width to form a wide portion having an abutting surface vertically facing the key. Excavation jig for pile construction. 9. The key is provided on the outer diameter surface of the excavation shaft, and the key groove is provided on the inner diameter surface of the cylindrical portion, and the wide portion opposes the key when the expanding blade is in a reduced diameter state. 9. The foundation according to claim 8, wherein a groove width is widened on a side wall side of the key groove against which the key is pressed when the drive shaft is normally rotated at the position, and the abutting surface is directed downward. Excavation jig for pile construction. 10. The key is provided on the inner diameter surface of the tubular portion, and the key groove is provided on the outer diameter surface of the excavating shaft, and the wide portion opposes the key when the expanding blade is in a reduced diameter state. 9. The foundation according to claim 8, wherein a groove width is widened on a side wall side of the key groove against which the key is pressed when the drive shaft is normally rotated at the position, and the abutting surface faces upward. Excavation jig for pile construction. 11. The key groove extends vertically in a spiral shape,
The extension direction is set so as to guide it upward as it goes in the forward rotation direction of the drive shaft, and the excavating jig for foundation pile construction according to any one of claims 5 to 10 is characterized. . 12. The excavating jig for constructing a foundation pile according to claim 11, wherein the inclination angle of the key groove is set within a range of an inclination angle of 10 degrees or more with respect to the axis. 13. A lock mechanism for restricting upward relative displacement of the drive shaft with respect to the excavation shaft when the expanded blade is in a diameter expanded state.
An excavation jig for constructing a foundation pile according to claim 12. 14. The lock mechanism includes a protrusion provided on the excavation shaft, and a hook-shaped member that protrudes downward from the drive shaft and has a hooking portion that can face the protrusion from below. The excavating jig for constructing a foundation pile according to claim 13, wherein. 15. The lock mechanism comprises a protrusion provided on a drive shaft, and a hook-shaped member protruding upward from the excavation shaft and having a hooking portion capable of facing the protrusion from above. The excavating jig for constructing a foundation pile according to claim 13. 16. The lock mechanism has a wide groove width on the side wall side of the key groove against which the key is pressed when the drive shaft rotates in the reverse direction, with respect to the key groove which the key faces when the expanding blade is in the expanded state. The excavating jig for constructing a foundation pile according to claim 13, wherein the excavating jig is constituted by a second wide portion.