JPS6131072Y2 - - Google Patents

Description

[Detailed description of the invention] This invention relates to a pile driving device, and more specifically, to a pile driving device that uses the cutter of an earth boring machine inserted into a hollow pile to be driven, excavates beneath the pile, and then drives the pile into the ground along this hole.

As shown in Fig. 1, with such a pile driving device, when a pile a such as a concrete pile is to be penetrated into the ground, the soil excavated with a cutter b at the tip is transported by means of transportation such as an auger c. When the material is transported to the ground, air or the like may be discharged from the nozzle d of the cutter device to assist in transportation. Furthermore, when pile driving is performed by connecting a large number of long piles, the underground boring machine may be raised a little in order to connect the upper pile to the lower pile after driving.

As the underground drilling machine is raised, the space under the pile becomes larger by the amount of volume reduced by the cutter and auger. However, as construction was completed, the pressure in the space under the pile decreased as the drilling machine was pulled up due to the fact that the valve in the air supply path to the nozzle was closed and the gap between the augers was clogged with soil. It becomes negative pressure.

For this reason, there is a difference in the pressure applied to the upper and lower ends of the pile, and a downward force acts on the pile a, which may cause the pile a to sink when the drilling machine is pulled up.

If this happens, not only will it be difficult to connect the pile a, but if it occurs at a predetermined penetration depth, it will become a serious problem in the pile driving process.

To avoid the above problem, a valve communicating with the atmosphere was installed in the air supply circuit connected to the nozzle of the drilling machine, and this valve had to be opened and closed every time the drilling machine was lifted, which was cumbersome. .

The present invention was developed with the above in mind, and when the space below the pile becomes negative pressure, air can be automatically flowed into this space without operating the valve each time. The purpose of the present invention is to provide a pile driving device that can prevent piles from sinking.

An embodiment of the present invention will be described below based on FIG. 2.

In the figure, 1 is a hollow pile such as a concrete pile that is driven into the ground, 2 is an underground boring machine that is inserted into this pile 1 and excavates below it, 3 is its cutter, and 4 is a nozzle. This nozzle 4 is connected via a hollow rod 5 of the underground drilling machine to a piping system 6 outside the machine. A mortar plant 7 for injecting cent milk and an air supply device 8 for injecting compressed air are connected to this piping device 6 via on-off valves 9 and 10, respectively. Also, between the piping device 6 and the on-off valve 10 on the air supply side, only the flow from the air supply device 8 is allowed, and a reverse flow is established to prevent the cement milk from the mortar plant 7 from flowing back to the air supply device 8 side. A stop valve 11 is interposed. A check valve 12 is connected between the check valve 11 and the on-off valve 10 on the air supply side, with one end open to the atmosphere and allowing flow from the atmosphere.

In the above configuration, after the underground drilling machine 2 excavates the lower part of the pile 1, the underground drilling machine 2 is pulled up to connect the pile 1, and when the space after that becomes negative pressure, the non-returning machine opens to the atmosphere. Atmospheric air flows in from the valve 12,
This space is prevented from becoming negative pressure. Note that at this time, both on-off valves 9 and 10 are closed.

Although the above embodiment shows an example in which the mortar plant 7 is connected to the piping device 6, the mortar plant 7 is omitted if the cement milk for hardening is not injected into the lower part of the pile and the foot hardening is done by hammer driving. You may.

The pile driving device according to the present invention is as described in detail above, and the cutter of the underground boring machine inserted into the hollow pile 1 to be driven is used to drill the lower part of the pile 1, and to drive along the hole. In a pile driving device, in which a nozzle 4 is provided at the tip of the underground boring machine, one side of the piping device 6 connected to the nozzle 4 is opened to the atmosphere. Since the check valve 12 that only allows flow from the side is connected, when the space below the pile 1 becomes negative pressure due to the lifting of the underground boring machine 2, the check valve 12 connects the piping to this space. Air is automatically supplied from the nozzle 4 via the device 6 to prevent the space below the pile 1 from becoming negative pressure,
It is possible to prevent the pile 1 from sinking due to negative pressure in this space without manually opening and closing the on-off valve each time.

[Brief explanation of the drawing]

FIG. 1 is a schematic structural explanatory diagram showing a conventional general pile driving device, and FIG. 2 is a structural explanatory diagram showing an embodiment of the present invention. 1 is a pile, 4 is a nozzle, 6 is a piping device, and 12 is a check valve.

Claims (1)

[Scope of utility model registration request] The cutter of the underground drilling machine inserted into the hollow pile 1 to be driven is used to excavate the lower part of the pile 1, and the pile 1 is penetrated into the ground along this hole, and the tip of the underground drilling machine is In a pile driving device equipped with a nozzle 4 in the part,
A pile driving device characterized in that a check valve 12 is connected to a piping device 6 connected to the nozzle 4, one side of which is open to the atmosphere and which allows flow only from this side of the atmosphere.