JPH047800B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] When constructing a cast-in-place concrete shaft, the present invention improves the soil bearing capacity by expanding a cylindrical pile hole drilled to a certain diameter into a conical shape. This is related to the so-called bottom-expanding excavator.

[Prior art] As a bottom-expanding excavator, the present applicant previously filed a patent application in 1980-
No. 118191 was filed. As shown in FIGS. 11 to 14, this consists of a cylindrical bucket 1 and a bucket 1.
Center pipe 2 attached to the shaft center of
, a spline shaft 3 fitted in and out of the center pipe 2, a crosshead 4 rotatably attached to the spline shaft 3 and fixed in the thrust direction, and an upper end of which is locked to the crosshead 4. Two connecting rods 5,5
, two wing expansion bits 6, 6 attached to the lower ends of the connecting rods 5, 5, and the wing expansion bits 6, 6.
When guided vertically along the center pipe 2 and guided downward of the center pipe 2, the expanded wing bits 6, 6 are inserted through a pair of openings 1a, 1a provided on the circumferential surface of the bucket 1, facing each other. Two guide rails 7, 7 which are inclined with respect to the axis so that the wing expansion bits 6, 6 are accommodated approximately within the diameter of the bucket belt 1 when they are projected and guided above the center pipe 2, and the spline shaft 3. a spline sleeve 8 fitted to the outer periphery of the bag; and an opening 1a provided on the circumference of the bucket 1, which is attached to the spline sleeve 8 via an arm 9.
It is equipped with a rotating lid 10 that opens and closes. The inner peripheral surface of the spline sleeve 8 is provided with a spiral protrusion 1 provided on the outer peripheral surface of the spline shaft 3.
A spiral protrusion 12 that engages with the protrusion 11 is provided, and a spiral protrusion 13 that engages with the protrusion 11 is also provided on the upper inner circumferential surface of the center pipe 2.

Then, as shown by the imaginary lines in FIG.
The bucket 1 is inserted into the pile hole 14 which is formed to have approximately the same diameter as the diameter of the bucket 1, and is placed on the bottom of the pile hole 14. When the pile is inserted into the center pipe 2, the rotary lids 10, 10 open, and then the bucket 1 and the wing bits 6, 6 rotate to excavate the circumferential surface of the pile hole 14, and the excavated soil is taken into the bucket 1 through the openings 1a, 1a. After the required amount of bottom expansion excavation has been carried out in this way, the spline shaft 3 is pulled out from inside the center pipe 2 while applying rotational force in the opposite direction (to the left) to the front. moves above the guide rails 7, 7 until it is within the diameter of the cylindrical bucket 1, and then the stepped portion 1
3a brings the rotary lids 10, 10 into a closed state, and in this state, the bottom-expanding excavator is pulled out from inside the pile hole 14 and discharged out of the hole. This operation is repeated until the wing expansion bits 6, 6 reach the lowest part of the guide rails 7, 7, and the bottom expansion excavation is completed.

During actual construction, the machine is suspended from the bottom of the shaft hole.
Before starting the bottom expansion excavation, the shaft is rotated to the left to take in the remaining soil, sand, slime, etc. at the bottom of the shaft hole, and then the bottom is expanded by turning to the right. In this case, even if a vertical force is applied by rotating to the left, the stepped portions 11a and 11b of the spline
are fitted, so the wing expansion bits 6, 6 do not slide and can be rotated to the left. The insertion and extraction of the bottom-expanding excavator into and out of the pile hole 14 and the rotation of the spline shaft 3 are performed by a crane device connected to three sockets by means of a kely bar (not shown).

[Problems to be Solved by the Invention] By the way, in the above-mentioned conventional bottom-expanding excavator, as shown in FIG.
Since the structure was such that the center pipe 2 was placed on top of the upper end of the center pipe 2 and the arm 9 was placed on the center pipe support frame 15 attached to the top of the bucket 1, the following problems occurred.

(1) Since the bucket 1 includes the center pipe 2, the bucket 1 becomes large.

(2) As the bucket 1 becomes larger, the total weight of the bottom-expanding excavator naturally increases, and a larger crane device is required to operate the bottom-expanding excavator.

(3) Along with the bucket 1, the rotating lid 10 also becomes larger.
Since it is heavy, the opening/closing operation of the rotary lid 10 becomes sluggish.

The present invention has been made for the purpose of solving the above-mentioned conventional problems.

[Means for solving the problem] As shown in FIGS. 6, 7, 8, 9, and 10, the spline sleeve 8 is rotatably fitted into the center pipe 2 and installed. In addition, a spiral protrusion 12 is provided on the upper inner peripheral surface of the spline sleeve 8 to engage with a spiral protrusion 11 provided on the outer peripheral surface of the spline shaft 3.
The upper inner peripheral surface of the center pipe 2 is provided with a protrusion 13 that engages with the protrusion 11 of the spline shaft 3, and the protrusion 11 of the spline shaft 3 has stepped portions 11a and 11b provided near its lower end. Stepped part 1
When 1a and 11b are engaged with the protrusion 13 of the center pipe, they are formed to have a rotation gap.

[Operation] With the spline shaft 3 moved upward relative to the center pipe 2, the spline shaft 3
When a clockwise rotational force and a normal force are applied to , first, the protrusion 11 of the spline shaft 3 and the protrusion 12 of the spline sleeve 8 come into contact with each other, and the spline sleeve 8 to the arm 9 rotate together with the spline shaft 3, and the rotating lid 10 will be held. At this time, spline shaft 3
Stepped portions 11a, 11 provided near the lower end of the protruding strip 11
The abutting surface of b with the protrusion 13 of the center pipe 2 is removed, and the spline shaft 3 can move up and down, and the center pipe 2 to bucket 1 subsequently rotate together with the spline shaft 3.

[Example] Next, an example of the present invention will be described with reference to FIGS. 1 to 10. 1 is a bucket formed into a cylindrical shape. The bucket bag 1 is formed into a cylindrical shape with a predetermined diameter, and has a pair of openings 1a on opposite sides of the circumferential surface.
1a is formed, and a bottom cover 1c is attached to the bottom portion by a pivot 1b so as to be openable and closable. 2
is a center pipe attached to the shaft center of bucket 1. The center pipe 2 is integrally formed with the bucket 1 by a center pipe support frame 15, and its upper half protrudes above the bucket 1. The center pipe 2 has a protrusion 11 of the spline shaft 3 and a screw thread on the upper inner circumferential surface of the center pipe 2. Spiral convex shape 13 to match
A cylindrical body 16 is attached. 3 is a spline shaft fitted into the center pipe 2 so as to be movable up and down. The spline shaft 3 is formed to have the same length as the center pipe 2, and has a spiral protrusion 1 provided on the inner circumferential surface of the upper part of the center pipe 2 on its outer circumferential surface.
3 and a spiral protrusion 11 and a stepped portion 11 that mesh with
a and 11b are provided. The spiral protrusions 11 and 13 are normally formed with an inclination angle of 13° to 16° with respect to the shaft, and when the spline shaft 3 is rotated clockwise, they are tilted downward by the rotational force. The spline shaft 3 is designed to generate a force component to offset the frictional force or to apply a slight downward vertical force to facilitate sliding of the spline shaft 3.
4 is a crosshead rotatably attached to the upper part of the spline shaft 3 in a fixed state in the thrust direction, and a socket 17 is provided at the upper part of the crosshead 4 for connecting a kely bar of a crane device (not shown). There is. Reference numerals 5 and 5 designate connection rods whose upper ends are attached to the crosshead 4, and these connection rods 5 and 5 are suspended from the spline shaft 3 by a pin shaft 5a in a state in which they can rotate about the shaft 5a as a fulcrum. It is installed in Reference numerals 6 and 6 designate wing expansion bits that are attached to the lower ends of the connecting rods 5 and 5 and that move in conjunction with the vertical movement of the spline shaft 3 (vertical movement). These expanding wing bits 6, 6 are provided with digging cutting edges 6a...6a on the outer and bottom surfaces, and these digging cutting edges 6a...6a are designed to excavate the circumferential surface of the pile hole 17, etc., and the inner surface. Guide block 6b
is attached, and by using the guide block 6b, it can be slidably attached to the guide rail described below. 7,7
is a guide rail, which is formed integrally with the center pipe 2 and is inclined at a required angle with respect to the axis;
When the wing expanding bits 6, 6 are guided in vertical movement and guided downward, the openings 1a, 1a provided in the circumferential surface of the bucket belt 1 allow these wing expanding bits 6, 6 to be opened.
This is a guide rail that projects outside of the bucket cart from one side and keeps the wing expansion bits 6, 6 within the range of the outer diameter of the bucket cart 1 when guided upward. These guide rails 7, 7 have openings 1a, 1a at their lower ends.
It is located near one side, and the upper end is installed in an inclined manner so as to create an expanded bottom excavation wall surface of a required angle, and when the wing expansion bit 6 is located on the lower end side,
The cutting edges 6a...6a of the wing-spreading bit 6 are connected to the opening 1.
When the wing expanding bit 6 is made to protrude outside the bucket 1 from one side of the bucket 1 and moved to the upper end side, the wing expanding bit 6 is kept within the diameter range of the bucket 1. A spline sleeve 8 is fitted around the outer periphery of the spline shaft 3, and the spline sleeve 8 is rotatably fitted within the center pipe 2 and below the cylindrical body 16 provided with the spiral protrusion 13. It is installed with
A spiral protrusion 12 is provided on the upper inner peripheral surface of the spline shaft 3 and engages with a spiral protrusion 11 provided on the outer peripheral surface of the spline shaft 3. Reference numerals 10 and 10 denote arc-shaped rotating lids connected to the lower end of the spline sleeve 8 via an arm 9, and these rotating lids 10 and 10 are located on the inner peripheral surface side of the bucket bag 1, It rotates around a spline shaft 3 to open and close the openings 1a, 1a of the bucket 1.

Since the bottom-expanding excavator of this embodiment has the above-described configuration, the spline shaft 3 is connected to the kely bar of the crane device (not shown), and the wing-expanding bits 6 are connected to the guide rail 7 in the same way as in the case of the conventional bottom-expanding excavator. , 7, the bottom expanding excavator is inserted into the pile hole 14, which has been formed in advance to have approximately the same diameter as the bucket 1, and the bucket 1 is inserted into the pile hole bottom 14a.
If the spline shaft 3 is placed on the bottom surface of the center pipe 2 and lowered into the center pipe 2 while applying clockwise rotational force and vertical force to the spline shaft 3, the spline shaft 3
The stepped portion 11a is released from contact with the upper part of the protrusion 13 formed on the inner peripheral surface of the upper part of the center pipe 2, and at the same time, the rotating lids 10, 10 are opened, and subsequently, the bucket belt 1 to the wing expansion bits 6, 6 are opened. Rotating, the wing expansion bit 6,
6 moves downward along the guide rails 7, 7, and excavates the circumferential surface of the pile hole 14 with the digging cutting edges 6a, . Once the required intake amount has been excavated, give the spline shaft 3 a slight rotation in the opposite direction (to the left) and pull it out from the center pipe 2.
6 moves upward along the guide rails 7, 7 and falls within the diameter of the cylindrical bucket 1, and the stepped portion 11a of the protrusion 11 comes out from the upper end of the center pipe 2. Then, the spline sleeve 8 rotates, and the rotating lids 10, 10 are in a closed state. Under this condition, the bottom-expanding excavator is pulled out of the pile hole 14 by a crane device, the bottom cover 1c is opened outside the hole, and the excavator is discharged. By repeating this operation and completing the bottom-expanding excavation, an enlarged-bottom pile hole with improved soil bearing capacity will be formed.

[Effects of the Invention] As explained above, the present invention has a structure in which the spline sleeve is rotatably fitted and attached within the center pipe, so that it has the following effects.

(1) By extending the lower end of the spline sleeve fitted into the center pipe downward and attaching the rotating lid to the lower end via an arm, the rotating lid or bucket can be made shorter and smaller than before. I can do it.

(2) By making the bucket and rotating lid smaller, the total weight of the bottom-expanding excavator can be reduced, and the crane device for operating the bottom-expanding excavator can be made smaller.

(3) Improved operability of the rotating lid.

[Brief explanation of drawings]

Figure 1 is a vertical side view of the wing expansion bit pushed down to the bottom of the guide rail, Figure 2 is a vertical side view of the same, and Figure 3 is a vertical cross section of the expansion bit pushed up to the top of the guide rail. Side view, Figure 4 is the 1st
Figure 5 is a plan view of Figure 3, Figure 6 is a sectional view of the main part with the spline shaft fully inserted into the center pipe, Figure 7 is the spline shaft pulled out of the center pipe to its maximum extent. 8 is a sectional view taken along the - line in FIG. 6, FIG. 9 is a sectional view taken along the - line in FIG.
Figure 0 is a cross-sectional view taken along the - line in Figure 7, Figure 11 is a vertical side view of the conventional example, Figure 12 is a front view of the same, Figure 13 is a cross-sectional view taken along the - line in Figure 12, and Figure 14 is a spline sleeve. This is a developed diagram. 1... Bucket, 2... Center pipe, 3...
...Spline shaft, 4...Crosshead, 5
... Connection rod, 6 ... Wing expansion bit, 7 ... Guide rail, 8 ... Spline sleeve, 9 ... Arm, 10 ... Rotating lid, 11 ... Projection, 11a ...
...Stepped portion, 12, 13...Convex strip.

Claims (1)

[Claims] 1 A cylindrical bucket 1, a center pipe 2 that is attached to the axial center of the bucket 1 and whose upper half protrudes from the top of the bucket 1, and a spline fitted into the center pipe 2 so as to be movable up and down. A shaft 3, a crosshead 4 rotatably and fixedly attached to the spline shaft 3 in the thrust direction, a connecting rod 5 whose upper end is locked to the crosshead 4, and a lower end of the connecting rod 5. A wing spreader bit 6 is attached to the spline shaft 3 and moves in conjunction with the vertical movement of the spline shaft 3, and a wing spreader bit 6 guides the vertical movement of the wing spreader bit 6, and when guided downward, the wing spreader bit 6 is connected to the circumferential surface of the bucket belt 1. a guide rail 7 that protrudes from an opening 1a provided in the bucket and fits the wing spreader bit 6 within approximately the outer diameter of the bucket 1 when guided upward; and a spline fitted to the outer periphery of the spline shaft 3. It includes a sleeve 8 and a rotating lid 10 attached to the spline sleeve 8 via an arm 9 to open and close an opening 1a provided on the circumferential surface of the bucket 1. The spline sleeve 8
A spiral protrusion 12 is provided on the upper inner peripheral surface of the center pipe 2 to engage with a spiral protrusion 11 provided on the outer peripheral surface of the spline shaft 3, while a protrusion 13 is provided on the upper inner peripheral surface of the center pipe 2. The convex ridge 11 of the spline shaft 3 is provided to transmit rotational force.
A bottom-expanding excavator is characterized in that the bottom-expanding excavator is engaged with stepped portions 11a and 11b provided near the lower end of the excavator with a predetermined play gap.