JPH0316953Y2 - - Google Patents

Description

[Detailed description of the invention] (Industrial application field) This invention relates to a pile hole drilling head and belongs to the industrial field of excavation machines.

(Prior Art) Conventionally, when excavating a pile hole, the pile hole excavation method is composed of a rotary shaft connected to the excavation shaft at the tip of the excavation shaft, and a spiral auger provided on the outside of the rotary shaft. The drilling head is installed and the excavation shaft is rotated from the ground. A drilling blade is fixed to the lower edge of the spiral auger, and the pile hole is excavated by the drilling blade.

When forming a bulbous portion at the lower end of the pile, it is necessary to form a portion at the bottom of the pile hole that has a larger diameter than the excavated pile hole. In this case, the upper or middle portion of the spiral auger A rotating arm is provided. When the excavation axis is reversed, the rotating arm is rotated by the reaction force from the hole wall, and the tip protrudes from the spiral auger.
This makes it possible to form parts with large diameters.

(Problem to be solved by the invention) However, since the properties of the hole wall of the pile hole excavated by the excavation head are not always in a constant state, when the excavation axis is reversed, the swivel arm Due to the reaction force from the wall, it was difficult to make the tip protrude beyond the spiral auger. Therefore, the reliability of protruding the swing arm was low and it was difficult to confirm, resulting in the problem that the piles were not installed as designed.

(Means for Solving the Problems) The pile hole drilling head of this invention has vertical shafts rotatably arranged side by side on the outside of the lower end of the rotating shaft, a horizontal axis fixed to the lower end of the vertical shaft, A grounding blade is fixed downward to the lower outer end of the horizontal arm, and at the upper end of the vertical axis there is a digging arm with a length that can protrude from the outer edge of the spiral auger, which is horizontal and at an angle with the horizontal arm. It is characterized by being firmly fixed.

One or more vertical shafts are installed,
The horizontal arm and the grounding blade are fixed to the lower end of each, while the digging arm is fixed to the upper end of each.

The grounding blade fixed to the bottom of the outer end of the horizontal arm may be at almost the same level as the digging blade fixed to the lower edge of the spiral auger, but it is better to have it protrude below the digging blade for better contact with the bottom of the pile hole. This is desirable because it is reliable.

The angle between the horizontal arm and the digging arm is determined by taking into account the length of the digging arm, so that when the rotating shaft rotates in the normal direction, the digging arm does not protrude beyond the outer edge of the spiral auger, but when the rotating shaft rotates in the reverse direction, the tip of the arm does not protrude beyond the outer edge of the spiral auger. Set the angle to make it more protruding.

(Function) According to the head for pile hole excavation of this invention, when the horizontal arm reliably receives the reaction force from the bottom of the pile hole and uses this as the turning force of the excavation arm, the protrusion of the excavation arm is prevented. It can be done reliably.

(Example) An example of this invention will be described below with reference to FIGS. 1 and 2.

In the figure, 1 is a rotating shaft connected to an excavation shaft (not shown), and two spiral augers 2, 2 are fixed to the outside, and the lower edges of the spiral augers 2, 2 are used for drilling inside and outside. Blades 3, 3 are fixed. On the outer side of the lower end of the rotating shaft 1, a flat plate bearing 4 is provided on the lower side and a bearing 5 having a U-shaped cross section is protruded on the upper side.
Vertical shafts 6, 6 are rotatably arranged parallel to each other.
A horizontal arm 7 is fixed at a right angle to the lower end of the vertical shaft 6, and a grounding blade 8 is fixed downward to the lower outer end of the horizontal arm 7. A removable digging arm 9 is fixed to the inside of the U-shaped bearing 5. The excavation arm 9 is longer than the length from the vertical axis 6 to the outer edge of the spiral auger 2, so that it can protrude beyond the spiral auger 2, and forms an angle with the horizontal arm 7 (in the embodiment, it is approximately 135 degrees), and when the horizontal arm 7 faces in the diametrical direction of the spiral auger 2, the digging arm 9 is located inside the spiral auger 2, as shown in Fig. 3, so that it does not protrude beyond the outer edge. It's getting old.

FIG. 3 shows the state of the pile hole drilling head of the above embodiment during normal rotation. That is, the rotation axis 1 is indicated by the arrow 1
Rotate in the 0 direction. At this time, the horizontal arm 7 receives a reaction force in the direction of the arrow 11 due to the grounding blade 8 in contact with the bottom of the pile hole, so the vertical shaft 6 and the excavating arm 9 also rotate in the same direction, and the excavating arm 9 It stops at the position where the side wall of the rotary shaft 1 comes into contact with the outer wall of the rotating shaft 1. As a result, a pile hole having the diameter of the spiral auger 2 shown by the chain line 12 is excavated.

Figure 4 shows the situation when the pile hole drilling head is reversed. That is, the rotating shaft 1 is rotated in the direction of the arrow 13, and at this time, a reaction force in the direction of the arrow 14 is transmitted to the horizontal arm 7 via the grounding blade 8 that is in contact with the bottom of the pile hole. The vertical shaft 6 and the digging arm 9 also rotate in the same direction until the side wall of the digging arm 9 comes into contact with the vertical wall 5a of the bearing 5 having a U-shaped cross section. This is the position where the digging arm 9 faces in the radial direction of the spiral auger 2, and the tip of the digging arm 9 protrudes from the outer edge of the spiral auger 2, making it possible to excavate a pile hole with a diameter larger than the diameter of the spiral auger 2. Become.

Incidentally, when the rotating shaft 1 is reversed, the spiral auger 2 is also reversed together with the rotating shaft 1. Therefore, the surrounding earth and sand receives a downward force from the spiral auger 2. This force acts on the digging arm 9 as an expanding force. That is, it can be said that the expansion of the excavating arm 9 is performed by the joint action of the force from the grounding blade 8 side and the force from the spiral auger 2 side. At this point the drilling arm 9
It is desirable to provide it close to the lower surface of the spiral auger 2 as in the embodiment.

Further, when the excavating arm 9 is expanded to perform enlarged excavation, the excavating arm 9 does not have a transport function for the earth and sand, but since the earth and sand is pushed down by the spiral auger 2, the earth around the excavating arm can be removed. , the excavation efficiency of the excavation arm 9 can be ensured.

(Effect of the invention) As explained above, according to this invention, the reaction force at the time of reversal is received by the grounding blade in contact with the bottom of the pile hole,
Since the excavating arm is rotated through this reaction force, it is possible to reliably control the plunge and sink from the spiral auger. Therefore, a large diameter pile hole for the bulb at the lower end of the pile can be excavated correctly, which has the effect of allowing the pile to be installed as designed.

[Brief explanation of the drawing]

Figure 1 is a front view of the embodiment of this invention, Figure 2 is a side view, and Figures 3 and 4 are A in Figure 1.
FIG. 4 is a diagram illustrating operations during normal rotation and reverse rotation using a cross-sectional view taken along line -A. 1...Rotating axis, 2...Spiral auger, 3...Drilling blade, 6...Vertical axis, 7...Horizontal arm, 8...Grounding blade, 9...
drilling arm.

Claims (1)

[Claims for Utility Model Registration] 1. A head for pile hole drilling in which a spiral auger is provided on the outside of a rotating shaft, in which vertical shafts are rotatably arranged side by side on the outside of the lower end of the rotating shaft,
A horizontal arm is fixed to the lower end of the vertical shaft, and a grounding blade is fixed downward to the lower outer end of the horizontal arm,
A pile hole drilling head 2 characterized in that an excavation arm with a length that can protrude from the outer edge of the spiral auger is fixed to the upper end of the vertical axis horizontally and at an angle with the horizontal arm. A pile hole drilling head 3 according to claim 1 of the utility model registration claim, in which a plurality of heads are installed, each having a horizontal arm and a grounding blade fixed to its lower end, and an excavating arm fixed to its upper end. A pile hole drilling head according to claim 1 of the utility model registration claim, which protrudes from a drilling blade fixed to the lower edge of a spiral auger.