JPS64439Y2 - - Google Patents

Description

[Detailed explanation of the invention] (Industrial application field) This invention is attached to the lower end of a concrete pile that is poured into the foundation ground, and is used to dig through the concrete pile in order to improve the soil bearing capacity of buildings, etc. Regarding excavation fittings used for.

(Prior art) Conventionally, in order to drive concrete piles into the ground of buildings, etc., highly pressurized water is ejected from the bottom of the concrete pile using iron pipes, and the surrounding soil is removed while sinking (water injection pile method). There are two methods: concrete piles are placed in holes that have been excavated in advance.

And, in Utility Model Publication No. 58-33147, a concrete pile is sunk into a buried hole that has been excavated in advance, and at the final stage of installation, the pile is rotated so that the lower end of the pile digs into the supporting ground and is firmly supported. In the construction method shown in Figure 1, feather metal fittings are fixed radially to the underside of an annular end plate attached to the lower end of the pile. In this case, the strength of the end plate is insufficient because the hole is made in the end plate on the center side of the blade fitting. Therefore, in order to solve the above problem, Japanese Utility Model Publication No. 58-33147 proposes a method in which a cylindrical body having mud removal holes is fixed to cover the central perforation of the end plate that covers the lower end surface of the concrete pile body. ing. However, even if the cylindrical body is fixed to the end plate as described above, since the blade fitting is made of a thin plate, the pile must be rotated in order to make the lower end of the pile dig into the supporting ground, and the blade plate can be used to secure the ground. When digging, the problem that the strength of the feather metal fittings is not sufficient and the feather metal fittings fall down and the lower end of the pile does not dig into the supporting ground remains unsolved. In addition, manufacturing the blade fittings is troublesome and requires a large number of man-hours for manufacturing.

(Problem to be solved by the invention) In view of the above, this invention allows drilling of holes not only in cases where holes for burying concrete piles have been drilled in advance, but also in cases where holes for burying concrete piles have not yet been drilled. The object of the present invention is to provide a concrete pile excavation fitting that can penetrate into the supporting ground with sufficient strength and does not require a large number of man-hours to manufacture unlike feather fittings.

(Means for solving the problem) In order to achieve the above object, this invention makes the outer periphery of the main body of the excavation fitting attached to the lower end of the concrete pile tapered, and along the tapered surface, the large diameter side and the small diameter side The structure is such that a chain can be installed across the sides.

(Function) When a concrete pile with a tunneling fitting attached to its lower end is placed upright at its buried position and rotated in the same manner as in the past,
The chains installed along the inclined surface of the main body of the tunneling fixture push the mud on the ground to the side while drilling a hole. When a concrete pile is inserted into the partially drilled hole and rotated, the tunneling fixture pushes the mud at the bottom of the hole to the side while drilling a hole.

(Example) Next, this invention will be explained based on an example shown in the drawings.

In Figures 1 to 4, the main body 2 of the digging tool 1 includes a tapered part 3 made of iron plate in the shape of a truncated cone, and a disc-shaped upper part fixed to the tip of the small diameter side of the tapered part 3. An annular fixing part 5 having a predetermined length fixed to the plate 4 and the large-diameter end of the tapered part 2
It is made up of

The chain 6 has one end 6a attached to the bottom plate 4 by a bolt 7 inserted into a hole in the bottom plate 4 from the outside, and a nut 8 screwed into the bolt 7 from the back side of the bottom plate 4. The fixing part 5 is fixed by a bolt 9 whose end 6b is inserted into the hole of the fixing part 5 from the outside, and a nut 10 screwed into the bolt 9 from the back side of the fixing part 5.
is attached to. The bolts 9 and nuts 10 that attach the chain 6 to the fixing part 5 have shaft holes 9a and 10a, respectively, passing through their shaft centers. Here, connect the chain 6 to the bottom plate 4.
As shown in FIG. 2, the bolt 7 attached to the excavation fitting 1 is located forward of the bolt 9 in the direction of rotation of the digging tool 1, so the chain 6 has a curved shape. In this way, three chains 6 are attached to the digging tool 1 at the same pitch. The body part 2 has an appropriate number of elongated holes 11 at the same pitch near the center of the conical part in order to insert the steel rods 12 when creating a concrete pile. It's opened.

When the concrete pile 13 is manufactured by a method using centrifugal force, the excavation fitting 1 formed as described above is attached to one end of the pile body 14 via the steel rod 12 to an end plate disposed at the other end of the pile body 14. It can be attached integrally with 15.

In the above configuration, the concrete pile 13
When the burial hole 16 is drilled at the burial position, when burying, insert the digging fitting 1 into the burial hole 16.
After inserting the side, the concrete pile 13 is rotated in a conventional manner. As the concrete pile 13 rotates, the digging tool 1 also rotates, and its three chains 6 scratch the mud at the bottom of the hole and enter the hole while pushing it laterally. In this case, since the chain 6 is very strong, it will not fall down and become useless like conventional blade fittings. Further, when the concrete pile rotates, the bolts 7 of the bottom plate 4 and the bolts 9 of the fixing part 5 also rotate, pushing away the mud and forming a void as it enters. Accordingly,
The concrete pile 13 can reliably dig into the supporting ground. Then, by injecting cement milk through the shaft holes 9a, 10a of the bolts 9 and nuts 10, the lower end of the concrete pile 13 is more firmly fixed to the ground.

In the above embodiment, the digging fitting 1 is fixed directly to the lower end of the concrete pile 13, but if an end plate is fixed to the lower end of the concrete pile 13, the digging fitting 1 can be attached to the end plate. become.

(Effects of the invention) As is clear from the above explanation, since we decided to attach the chain to the excavation fitting, there is no damage to the excavation fitting while burying the concrete pile, and the excavation fitting is attached to the supporting ground. It can be powerfully and reliably penetrated. Further, since a commercially available chain can be used to be buried underground together with the concrete pile, the number of man-hours required for manufacturing it can be reduced, and the manufacturing cost of the excavation fitting can be extremely reduced.

[Brief explanation of drawings]

Figures 1 to 4 show an embodiment of this invention,
Figure 1 is a partially cutaway front view of the excavation fitting, Figure 2 is a plan view of Figure 1, Figure 3 is an enlarged view of part A in Figure 1, and Figure 4 is a partial cross section of the concrete pile. It is a diagram. DESCRIPTION OF SYMBOLS 1...Drilling metal fitting, 2...Main body part, 3...Tapered part, 4...Bottom plate, 5...Fixing part, 6...Chain, 6a...One end, 6b...Other end, 7...Bolt, 8...nut, 9...bolt, 10...nut, 13...concrete pile, 14...pile body.

Claims (1)

[Scope of utility model registration request] An excavation fitting attached to the lower end of a concrete pile, characterized in that the outer periphery of the main body is tapered, and a chain is attached along the tapered surface between the large diameter side and the small diameter side. digging metal fittings.