JPH0227031Y2 - - Google Patents

Description

[Detailed description of the invention] (Field of industrial application) This invention is for underground excavation, which is used by attaching it detachably to the lower end of an excavator such as an auger screw when driving ready-made hollow piles into the soil. It concerns expansion heads.

(Prior art) Various methods of constructing bulbs at the bottom of this type of foundation pile have been seen here and there, but generally speaking, after burying a hollow pile to a predetermined depth, the lower end of the hollow pile is placed at the base of the expansion site. This involves digging a trench and pouring cement milk into the expanded area to create a bulb at the bottom of the hollow pile.

As for the conventional technology, for example,
- As seen in Publication No. 17835, an expansion head is attached to the lower end of the auger screw, its expansion blade is closed, and its stopper is engaged with the stopper for regulating the closed position of the drilling bit body, and the drill bit is inserted into the hollow pile. When the bit is inserted and the lower end protrudes, the auger screw is reversed, the expansion blade is pushed outward by the resistance of the earth and sand, the stopper of the pile tensioning blade is disengaged from the stopper for regulating the closed position of the bit body, and the auger screw is further removed. There is one that drills a hole with a large diameter by lowering the expandable blade and gradually expanding it by the restoring force of a coil spring.

However, in such a case, since the expansion blade of the expansion head is designed to release the engagement of the stopper by direct earth pressure resistance, if the soil is soft, the expansion blade, which is heavy, may be used. This has the disadvantage that it may not open, making it impossible to expand the excavation beyond the diameter of the pile. Furthermore, since the stopper of the expansion blade engages with the stopper for regulating the closed position of the excavation bit body, when the expansion blade hits a hollow pile, etc., both stoppers easily come off and the expansion blade expands to prevent work. It has drawbacks such as being very time consuming.

(Problems to be solved by the invention) This invention was devised to improve each of the above-mentioned drawbacks. It is necessary to expand the wing pieces, to be able to reliably pull them out from the hollow pile, and to ensure that the expanded wing pieces do not expand unless necessary.

However, an expansion head that satisfies these demands has not yet been found, and the appearance of one has been awaited.

This idea has been proposed in response to the above-mentioned demands.

(Means for Solving the Problems) In order to solve all of the above-mentioned problems, the expansion head of this invention is equipped with opposing expansion wing pieces that expand and contract left and right on the body of the head body. death,
Opposite rotating cam hooks for operating expansion and contraction are attached to the lower part of this expansion wing piece with a movable shaft, and the rotating cam hook has a short piece at the upper part and a long piece at the lower part. In addition, the above purpose is achieved by forming a locking step on the side surface for locking and disconnecting.

(Embodiment) Next, an embodiment of this invention will be described with reference to the drawings. A head body A that is detachably attached to the lower end of an auger screw, etc. has a joint part 2 at the upper part and a body part 1 at the lower part. Above the body part 1, screw blades 3 are formed which are connected to the screw blades of the auger screw. Further, inside the head body A, a communication passage 19 is formed for injecting air, mortar, and other chemical liquids.

In the lower part of the body part 1, opposed expansion wing pieces 5, 5 which expand and contract laterally are fitted onto the axis of the central shaft part 7. One end 13 of a coil spring 8, which always urges the expanded wing pieces 5 in an open state, is fixed to a fixing part 9 provided at the end of the shaft part 7.

A spring covering lid 10 that covers the bases of the expanded wing segments 5, 5 from the outside is fixed to the expanded wing segments 5, 5 with fixing screws 12, 12. This spring covered lid 10
The coil spring 8 is housed inside, and fixing rods 11, 11 are inserted and fixed to the spring cover lid 10, and the other end portion 14 of the coil spring 8 is secured by the fixing rods 11, 11. and the extended wing piece 5,
5 in the direction of expanding outward.

Next, below the expansion blades 5, 5, opposing rotary cam hooks 6, 6 for expanding and contracting the expansion blades 5, 5 are mounted on movable shafts perpendicular to the expansion blades 5, 5. 1
It is pivoted with 5. The rotary cam hooks 6, 6 are provided with a short piece 16 at the top and a short piece 1 at the bottom.
By forming a long piece 17 longer than 6, the long piece 1 is always
7 is in the lower position. On the side surface of the rotary cam hook 6, the extended wing pieces 5,
A latching protrusion 18 is formed to maintain the stop when 5 is in the retracted position. Reference numeral 20 indicates the communication path 19
21 is a stop step, and this stop step 21 restricts the rotation of the rotary cam hook 6 during normal rotation. It fulfills the role of Reference numeral 22 indicates a drilling bit provided on the side surface of the expanded wing pieces 5,5.

Further, a stop portion 23 is formed on the side surface of the frame portion 1 to define the expanded position in which the expanded wing pieces 5, 5 are maintained in the expanded state.

(Function) This device has the above-mentioned configuration, and to explain how to use this embodiment now, when a hollow pile is driven into the ground and the ground at the lower end is to be expanded and excavated, it is necessary to The head body A of this invention is attached to the lower end of the auger screw, and the extended wing pieces 5,
5 is contracted against the coil spring 8, and the sides of the expanded wing pieces 5, 5 are locked with the locking protrusion 18 of the rotary cam hook 6 as shown in FIG. 5, and inserted into the hollow pile. . At this time, during normal rotation, the lower long piece 17 of the rotary cam hook 6 is resisted by the earth and sand, and since it tries to move counterclockwise from the state shown in FIG. 6, the rotary cam hook 6 is always rotated. The locking protrusion 18 can hold the expansion wing piece 5 in a locked state.

Next, when you want to completely protrude from the bottom end of the hollow pile and expand the excavation, reverse the auger screw.
This time, the lower long piece 17 of the rotary cam hook 6 moves clockwise due to earth pressure from the opposite side of the earth and sand, and the locking protrusion 18 of the rotary cam hook 6 moves clockwise. By detaching from the expanded blades 5, 5 and further lowering them, the expanded blades 5, 5 are sequentially expanded by the urging of the coil spring 8. Then, if the auger screw is rotated normally after being expanded to the maximum position, the expansion wing pieces 5, 5 stop opening at the stop part 23 to carry out expansion digging, and air, water, and cement are supplied from the communication path 19. Pour milk, etc., and stir thoroughly by turning the mixture upside down to form a bulb.

Next, after the enlarged excavation is completed, when the auger screw is pulled up, the upper edge of the expanded wing pieces 5, 5 will hit the lower end of the hollow pile, and due to the resistance from the hollow pile, the expanded wing pieces 5, 5 will be lifted up. It is pushed and retracted by the internal coil spring 8, and in that state is pulled up inside the hollow pile and pulled out.

It should be noted that this idea can naturally be implemented when enlarging the excavation at the same time as erecting hollow piles, or when excavating with a casing auger attached to the outer periphery of the auger screw.

(Effects of the invention) As described above, according to this invention, when the expansion head for excavation passes through the inside of the hollow pile, the expansion wings can be reliably maintained in the reduced position, so that the passage inside the pile is prevented. The effect is quick and easy, and the slight counter-rotation of the head body ensures the expansion of the expanded winglets, effectively creating the root ball.

The expansion blades are retracted by the opposing expansion wing pieces provided at the lower part of the body of the head body and the opposing rotating cam hooks installed at the lower end of the expansion blades. The locking operation can be easily and reliably held by moving the locking member, and the locking operation is very simple. Furthermore, by making the upper part of the rotary cam hook a short piece and the lower part a long piece, the rotary cam hook can always maintain a normal vertical position with the long piece facing down, and also have a long piece with respect to the reversal direction. One side is pressed by the earth and sand and moves reliably, and the locking protrusion provided on the side of the rotary cam hook also moves together to ensure detachment from the extended wing piece, which is an excellent effect. be.

[Brief explanation of the drawing]

Figure 1 is a front view of this device in an expanded state, Figure 2 is a bottom view of Figure 1, Figure 3 is a side view of the device in a contracted state, and Figure 4 is a cross-sectional plane with the coil spring portion removed. 5 is a perspective view of the extended wing piece and the rotary cam hook in a locked state, and FIG. 6 is a front view of the rotary cam hook. Symbol A is the head body, 1 is the main body, 2 is the joint, 5 is the extended wing piece, 6 is the rotary cam hook, 7 is the shaft,
8 is a coil spring, 9 is a fixing part, 10 is a spring covering lid, 11 is a fixing rod, 13 is one end, 14 is the other end, 16 is a short piece, 17 is a long piece, 18 is a latching protrusion,
21 is a stop step portion, and 23 is a stop portion.

Claims (1)

[Scope of utility model registration request] The head body A, which is detachably attached to the lower end of a load such as an auger screw, has an upper joint part 2,
and a lower body part 1, said body part 1
In the lower part of the holder, opposed expansion wing pieces 5, 5 which expand and contract laterally are fitted into a central shaft part 7, and at the end of the shaft part 7 there is a coil spring which is energized into an open state. 8, 8 are housed and fixed, and below the expansion blades 5, 5, opposite rotating cam hooks 6, 6 for expanding and contracting the expansion blades 5, 5 are installed. The rotary cam hooks 6, 6 have a short piece 16 at the top and a long piece 17 at the bottom.
In addition to forming a latching protrusion 1 on the side surface for engagement and disengagement.
1. An expansion head for underground excavation, characterized in that it has a diameter of 8 and 18.