JPS6115208B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a pipe expansion device for steel pipe piles.

Conventional technology For example, steel pipe piles used for steel tower foundations, etc., are subjected to upward pulling force, so conventionally, protrusions are welded to the tip or outer circumference of the pile, or spiral blades are wrapped around them. There is a problem in that it takes time and effort to fix the pile, and the protrusions and spiral blades get in the way when inserting the pile into a hole in the ground, making it difficult to insert it smoothly.

Therefore, a steel pipe pile is erected in the soil, a pipe expansion device is inserted into the steel pipe pile, the diameter of a predetermined portion of the steel pipe pile is expanded by this pipe expansion device, and the pipe expansion device is pulled out from inside the pile. A possible construction method is to fill the inside with filler.

Problems to be Solved by the Invention However, there has been no suitable pipe expansion device for the above-mentioned construction method. However, as a pipe expansion device used in the construction of concrete piles with spot bumps, there is one that expands the diameter of a thin-walled sheath pipe with slits made of metal or synthetic resin. (Special Publication No. 49-40964). In this method, an expansion tube made of an elastic body is inserted into a sheath tube, and high-pressure water is injected into the expansion tube to expand it, thereby expanding the diameter of the sheath tube. However, such diameter expanding devices simply use high-pressure water to inflate the expansion cylinder, so they cannot provide a strong enough expansion force to expand the diameter of steel pipe piles that can be used for tower foundations, etc. Moreover, a high-pressure water injection device was required, making the entire device large-scale.

An object of the present invention is to provide a pipe expansion device for steel pipe piles that solves the above-mentioned conventional problems.

Means for Solving the Problems In order to solve the above problems, the steel pipe pile expansion device of the present invention includes a cylinder device, a bracket fixed to the main body and the tip of the piston stem, respectively, of the cylinder device, and the piston stem. A plurality of diameter expanding blocks disposed around the piston stem, connecting links disposed between the diameter expanding blocks and a bracket of the cylinder device main body, and between the diameter expanding blocks and a bracket at the tip of the piston stem. The structure consists of the following.

Effect According to the above configuration, by inserting the pipe expansion device into the steel pipe pile and retracting the piston stem of the cylinder device, the diameter expansion block moves radially outward of the steel pipe pile, and the diameter expansion block moves the steel pipe The pile is pushed out.

Embodiment Hereinafter, an embodiment of the present invention will be described based on FIGS. 1 to 5.

1 is a steel pipe pile, and slits 2 along the longitudinal direction of the steel pipe pile 1 are formed at appropriate locations (three locations in this example) near the tip of the steel pipe pile 1 at regular intervals in the circumferential direction. be. Therefore, the portion of the steel pipe pile 1 where the slit 2 is located is strong against the pressing force applied in the longitudinal direction of the steel pipe pile 1, but is relatively weak against the pressing force applied in the direction transverse to the steel pipe pile 1.
Reference numeral 3 denotes a tube expansion device, which includes a cylinder device 4, six brackets 5 and 6 fixed respectively to the outer circumferential surface of the lower end of the main body 4a of the cylinder device 4 and the outer circumferential surface of the tip of the piston stem 4b, and the surroundings of the piston stem 4b. six diameter expansion blocks 7 arranged in the
A connecting link 8 is provided between the diameter expanding block 7 and the bracket 5 of the cylinder body 4a, and between the diameter expanding block 7 and the bracket 6 of the piston stem 4b. Reference numeral 9 designates a wire rope for suspending the tube expansion device, the lower end of which is wrapped around a hanging fitting 10 at the upper end of the cylinder body 4a, and 11 a hydraulic pipe connected to a port of the cylinder body 4a.

When installing the steel pipe pile 1, first, as shown in FIG. 1, the steel pipe pile 1 is driven into the soil with a hammer and erected. Other methods for erecting the steel pipe pile 1 in the soil include a deep excavation method in which an auger is inserted into the steel pipe pile 1 and the steel pipe pile 1 is erected in the soil while excavating the soil, and a hole is drilled into the soil. There is a pre-boring method in which a steel pipe pile 1 is inserted into the hole after excavating the hole.

Next, the pipe expansion device 3 suspended by the wire rope 9 is brought above the steel pipe pile 1. Note that at this time, the piston stem 4b is extended. Next, the wire rope 9 is unwound and the tube expansion device 3 is inserted into the steel pipe pile 1, and the diameter expansion block 7 comes to the bottom slit 2 as shown by the solid line in FIGS. 4 and 5. By the way, the descent of the pipe expansion device 3 is stopped. Next, when the piston stem 4b is retracted,
As shown by the imaginary lines in FIGS. 4 and 5, the diameter expanding block 7 moves horizontally outward via the connecting link 8 and presses the portion of the steel pipe pile 1 where the slit 2 is formed, as shown in FIG. As shown, this part is enlarged in diameter. Next, the piston stem 4b is extended to return the diameter expansion block 7 to its original state shown in solid lines in FIGS. 4 and 5, and the tube expansion device 3 is lifted up to open the remaining central and upper portions where the slits 2 are formed. Expand the diameter using the same procedure as above. Next, after the pipe expansion device 3 is lifted and pulled out from inside the pile 1, the inside of the pile 1 is filled with concrete. In this case, if it is necessary to prevent the concrete from flowing out from the slits 2, the slits 2 should be installed on the inner peripheral surface of the steel pipe pile 1 (or on the outer peripheral surface of the steel pipe pile 1) as shown by the imaginary line in Figure 4. Closing cylindrical rubber cover 13
should be installed in advance. The rubber cover 13
Since it has elasticity, it does not interfere with the diameter expanding operation by the diameter expanding device 3.

In the above embodiment, the amount of pipe expansion can be confirmed by detecting the amount of movement of the piston stem 4b with a limit switch, using a differential transformer, or by detecting the amount of oil returning from the cylinder body 4a to the tank. Bye. In addition, to change the amount of pipe expansion, as long as it is within the small diameter range, it is sufficient to simply replace the bracket 6 and the connecting link 8 at the tip of the piston stem 4b, and even when changing the amount of large diameter,
It is only necessary to replace the cylinder device 4 and beyond. (There is no need to change the control hydraulic unit, stroke detector, piping hoses, etc.), so it can be handled with relatively inexpensive equipment.

As described above, according to the pile pipe device 3 for the steel pipe pile 1 in this embodiment, by retracting the piston stem 4b of the cylinder device 4, the connecting cylinder 8
Since the diameter expanding block 7 is moved radially outward of the steel pipe pile 1 and presses the steel pipe pile 1 via the diameter expanding block 7, for example, the contact area of the diameter expanding block 7 with the steel pipe pile 1 must be set appropriately. As a result, an extremely strong tube expansion force can be obtained, and the steel pipe pile 1 can be expanded easily. Moreover, since a conventional high-pressure water injection device is not required, the entire device can be made compact.

Incidentally, instead of the slits 2, an appropriate number of windows may be formed, a plate may be disposed in the window, and the plate may be bent by a tube expansion device to protrude outside the steel pipe pile.

Effects of the Invention As described above, according to the steel pipe pile expansion device of the present invention, a cylinder device is used and the contact area of the diameter expansion block with the steel pipe pile can be freely set. It is possible to obtain pipe expansion force and easily expand steel pipe piles. Moreover, since a high-pressure water injection device is not required, the entire device can be made compact.

[Brief explanation of the drawing]

The figures show one embodiment of the present invention, Figures 1 and 2 are schematic diagrams showing the procedure for installing a steel pipe pile, Figure 3 is a perspective view of the expanded section of the steel pipe pile, and Figure 4 shows the state of the pile being inserted. FIG. 5 is a partially cutaway front view of the tube expansion device, and FIG. 5 is a plan view of the same device. DESCRIPTION OF SYMBOLS 1... Steel pipe pile, 3... Pipe expansion device, 4... Cylinder device, 4a... Cylinder body, 4b... Piston stem, 5, 6... Bracket, 7... Diameter expansion block, 8... Connection link.

Claims (1)

[Claims] 1 A cylinder device, a bracket fixed to the main body of the cylinder device and the tip of the piston stem, a plurality of diameter expanding blocks arranged around the piston stem, and a bracket between these diameter expanding blocks and the cylinder device main body. 1. A pipe expansion device for a steel pipe pile, comprising connecting links disposed between the diameter expansion block and the bracket at the tip of the piston stem.