JPS6351209B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to improvements in embedded pile construction equipment.

Generally, it is known to increase the bearing capacity of an embedded pile by forming an enlarged base larger than the diameter of the pile at the tip of the pile.

Conventionally, such holes for embedding piles and enlarged holes for enlarged foundations have been formed using the following construction equipment. That is, this construction device includes a screw auger and an auger head replaceably attached to the tip of the screw auger.
The auger head is fitted with enlarged vanes that form enlarged holes. When the screw auger is rotated in the forward direction, the expansion blades expand due to the resistance of the soil to form an enlarged hole, and when the screw auger is rotated in the reverse direction, the blades close due to the resistance of the soil and do not excavate the soil.

However, such construction equipment has a drawback in that the screw auger cannot be pulled out if an excessive resistance force is applied to the expanding blade, such as when the expanding blade digs into the soil. Additionally, there was a fear that soil would accumulate on the mounting portion of the expanding blade, making the expanding action of the expanding blade impossible.

An object of the present invention is to provide an embedded pile construction device that improves the drawbacks of the prior art as described above.

In order to achieve this object, the embedded pile construction device according to the present invention includes a screw auger inserted into the inner hole of the pile to be embedded, and an auger head replaceably attached to the tip of the screw auger. The auger head has a main body, a plurality of fixed blades for digging formed at the tip of the main body, and a plurality of enlarged blades for digging attached to the main body, the enlarged blades having: It has a blade attachment part pivotally attached to the main body by a mounting pin, and a blade arm part extending from the blade attachment part, and the enlarged blade is such that when the auger head rotates forward, the tip of the blade arm part is bent due to the resistance of the soil. The auger head excavates the soil while expanding diagonally upward, and when the auger head rotates in the opposite direction, it closes due to the resistance of the soil and does not excavate the soil. It is characterized in that it has a cleaning liquid port for cleaning a mounting part and a mounting pin, and the thickness ratio of the blade mounting part and the blade arm part is set to 3:2.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In Fig. 3, a screw auger (hereinafter referred to as auger) 2 is inserted into the inner hole of the pile 1, and the enlarged blade 4 of the auger head 3, which is attached to the auger 2 in advance, is in an enlarged state due to normal rotation as shown in Fig. 3a. While excavating and removing soil, pile 1 is sunk to a predetermined supporting ground. The enlarged diameter of the enlarged blade 4 during this excavation and settling, that is, the inner diameter of the excavated portion 5, is preferably about 2 to 5 cm larger than the pile diameter. If the diameter is too large, there will be many gaps on the outside of the pile, which may cause the pile to tilt or settle when the foundation is expanded, resulting in a lack of stability.If the diameter is smaller than the outside diameter of the pile, the friction on the circumferential surface of the pile will increase, making it difficult to sink. .

Next, as shown in Fig. 3b, the auger 2 is rotated in the opposite direction to close the expanding blade 4, and the auger 2 is replaced with the auger head 3, which has a larger enlarged diameter. Insert into.

Next, as shown in FIG. 3c, the pile is rotated in the normal direction, and the excavated portion 5 at the tip of the pile 1 is enlarged and excavated with the enlarging blade 4, and the earth is dug down and removed to form an enlarged excavated portion 5'.

Next, the cement mortar 6 is passed through the shaft hole of the auger 2 as shown in FIG.
When the mortar is injected and stirred with the expanding blade 4, an expanded mortar base 6' is formed at the tip of the pile 1.

When a predetermined amount of mortar 6 has been poured and stirred, the auger 2 is rotated in the opposite direction as shown in FIG. 3e, the enlarged blades 4 are closed and pulled up, and the embedding of the pile is completed by waiting for the enlarged mortar base 6' to harden.

The construction device according to the present invention used in this construction method has an auger head 3 according to the present invention replaceably attached to a screw auger 2 attached to an ordinary pile driver, as shown in FIGS. 1 and 2. It is. The auger head 3 has a hollow body 3a,
At the tip of this main body, a plurality (two in the figure) of fixed blades 11 for digging are provided which protrude downward. Further, the main body is provided with the same number of expanding blades 4 for excavation as the fixed blades, and the expanding blades are composed of a blade attachment part 4' attached to the main body 3a and a blade arm part 4'' extending from this blade attachment part. The blade mounting portion 4' is pivotally mounted to the main body by a mounting pin 8.
Therefore, when the auger 2 is rotated in the direction shown by the arrow in FIG. It closes by rolling it up.

Therefore, the excavation diameter becomes larger as the length of the expansion blade 4 increases.If the length of the expansion blade 4 is changed and the degree of curvature and the size and shape of the auger head 3 are adjusted accordingly, an auger with the same outer diameter can be obtained. It is easy to change the excavation diameter with head 3.

In addition, the thickness ratio of the blade attachment part 4' and the blade arm part 4'' is set to 3:2, and the blade arm part 4'' is made into a curved shape, unlike the conventional shape that opens horizontally or diagonally downward. It has the characteristic of opening and closing more smoothly than other products, and even when the expanding blade is subjected to excessive resistance, only the blade arm 4'' breaks, and unlike conventional products, the expanding blade cannot be pulled up due to deformation. It also has the feature that it can be pulled up and replaced without damaging any parts.

Furthermore, in addition to the tip port 7 of the auger head 3, there are injection ports for cement milk, cement mortar, etc., such as the inside of the enlarged blade 4, the blade attachment part 4', and the attachment pin 8.
A cleaning liquid opening 10 is provided in the upper part of the mounting pin 8 facing downward so that the cleaning liquid can be cleaned. This is because when the expansion blade 4 is rotated in the opposite direction to close it, it will not close if a lump of earth and sand gets caught in it, so it is cleaned with injection liquid to prevent such an accident.

In addition, the mounting part 9 between the auger 2 and the auger head 3 is square to prevent slippage during rotation, and a bolt hole 9' is provided in the mounting part 9 to insert a bolt to prevent the auger head 3 from falling off. It is as follows. As described above, this auger head has a hole that is smaller than the inner hole of the pile 1 depending on the direction of rotation, and has the expanding blade 4 that can be enlarged and excavated larger than the outer diameter of the pile 1, so that enlarged excavation can be easily performed. If you lift the auger 2 while it is enlarged as described above, it will hit the tip of the pile 1, so you can confirm that you are enlarging the excavation.

In addition, if excessive resistance is received from boulders etc. during excavation, the auger 2 may bend, the auger head 3 may become deformed or damaged, or become unable to be pulled up, resulting in an accident where the auger 2 is thrown away. 4'' is broken, so care has been taken to prevent such an accident.In addition, the shape of the expanding blade 4 is one that smoothly expands diagonally upward and contracts diagonally downward depending on the direction of rotation, and the blade 4 and the auger shaft are Consideration has also been given to cleaning with cement milk spouted from the cleaning fluid port 10 to prevent lumps of earth and sand from being caught in between and causing irreducible accidents.

Note that the connecting portion 9 between the auger 2 and the auger head 3 is rectangular, and rotational force is reliably transmitted through fitting, so a pin connection, which is the simplest connection method as shown, is sufficient in the axial direction. It is not limited to this.

As described above, the construction equipment of the present invention is mainly based on an auger head that has a number of features, and the construction method of the present invention that utilizes the auger head integrally forms an expanded base of cement mortar of a required diameter on the supporting ground. This is a useful tool that can be used to measure the effective use of piles, as it strengthens the pile and its size can be confirmed by the size of the enlarged blade during excavation.

The above-mentioned embodiment of the construction equipment was explained as a so-called hollow construction method in which an auger is inserted into the inner hole of a ready-made pile and the ground at the tip of the pile is excavated with the expanding blade 4. Even if it is not possible to insert the pile into the ground, an expanded base can be formed by first preboring to the specified ground, replacing the auger head, enlarging only the tip, injecting cement mortar, and then inserting and setting the pile.

According to the present invention, since the ratio of the blade attachment part to the blade arm part is set to 3:2, when excessive force is applied to the enlarged blade, the blade arm part breaks and the auger can be smoothly pulled out. Further, there is a practical benefit in that the cleaning liquid from the cleaning liquid port can prevent soil from being accumulated on the blade attachment part.

[Brief explanation of drawings]

Fig. 1 is a perspective view of an auger head according to the present invention, Fig. 2 is a half-sectional side view thereof, and Figs. 3 a to e.
FIG. 2 is a continuous process explanatory diagram of the embedded pile construction device according to the present invention. 1...Pile, 2...Spiral auger, 3...
Auger head, 4...Expanding blade for excavation, 4'
...Blade mounting part, 4''...Blade arm part, 5...Excavation part, 5'...Expanded excavation part, 6...Cement mortar, 6'...Expanded base, 7...Tip opening, 8... Mounting pin, 9... Mounting part, 9'... Bolt hole, 10
...Cleaning liquid port, 11...Fixed blade for excavation.

Claims (1)

[Claims] 1 A screw auger inserted into the inner hole of a pile to be embedded, and an auger head replaceably attached to the tip of the screw auger, the auger head having a main body and a screw auger formed at the tip of the main body. a plurality of fixed blades for digging; and a plurality of enlarged blades for digging attached to the main body; and a blade arm extending from the auger head, and when the auger head rotates in the forward direction, the tip of the blade arm expands diagonally upward due to the resistance of the soil and excavates the soil, and when the auger head rotates in the reverse direction, the blade arm excavates the soil. is configured to reversely close due to the resistance of the soil so as not to excavate the soil, and the main body has a tip opening for pouring out cement mortar and a cleaning liquid opening for cleaning the blade mounting portion and the mounting pin, An embedded pile construction device characterized in that a thickness ratio between the blade attachment portion and the blade arm portion is set to 3:2.