JPH0240150Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a hydraulic cylinder protection structure for advancing and retracting the iron body of the rotating shaft of a pile driving device.

Conventionally, when drilling a pilot hole at the driving point in order to drive a pile into the ground, a trowel body that can move forward and backward via a hydraulic cylinder on the rotating shaft is used to pour excavated soil onto the inner wall of the hole. There is a construction method that reduces the amount of excavated soil discharged and increases the supporting capacity of the pile by filling a portion of the pile and causing a consolidation phenomenon on the inner wall surface. A lateral load is applied to the rod tip of the cylinder, and since the cylinder rotates in excavated soil, the exposed sliding surface of the cylinder, the outer circumferential surface of the rod, will be damaged by sand and gravel, etc.
The drawback was that the cylinder was frequently damaged.

In this invention, the iron body is attached to the tip of the rod of the hydraulic cylinder so as to be able to swing freely, and the swinging cylinder and the cylindrical body, which are respectively fixed to the iron body and the rotating shaft, are overlapped, and the rotating shaft is As the iron body swings due to the rotation and ground resistance, the overlap part bends and generates a strong frictional force in the overlap part.
By integrating the swinging cylinder and the cylinder, it supports the lateral load applied to the rod, and also protects the rod from gravel in the excavated soil by covering the cylinder to prevent damage to the hydraulic cylinder. The purpose of this invention is to provide a protective structure for a hydraulic cylinder for advancing and retracting the iron body of a rotating shaft of a pile driving device.

Describing the embodiment of this invention in detail based on the drawings, A indicates a pile driving device, which is composed of a base machine 1 and a high-pressure water pump 2, and the machine 1 is a leader installed on a movable body 3. 4 vertically supports the rotating shaft 5, and while rotating the coaxial shaft 5 by a hydraulic motor 6 interposed between the rotating shaft 5 and the leader 4, the coaxial shaft 5 is lowered along the leader 4, and the lower end of the coaxial shaft 5 is lowered. The cutting edge 7 connected to the
A pilot hole 8 for pile driving is drilled in the ground G, and a part of the excavated soil is applied to the inner wall surface of the pilot hole 8 using a trowel body 9 connected above the cutting edge 7 of the rotary shaft 5. It is composed of The high-pressure water pump 2 communicates with a high-pressure water nozzle 11 via a swivel joint 10, and the jet of high-pressure water from the nozzle 11 facilitates excavation of the cutting edge 7 and turns the excavated soil into mud. and assists the coating action of the iron body 9.

The iron body 9 rotates integrally with the rotating shaft 5 in the mud inside the pilot hole 8, and the front edge 9-1 of the iron body 9 is inclined inward. The mud raked up in step -1 is pressed onto the inner wall surface 8-1 of the pilot hole 8 by the rear edge portion 9-2 of the iron body and is applied thereto. A hydraulic cylinder 12 is interposed between the iron body 9 and the rotating shaft 5.
The second base end 12-1 projects radially from the outer circumferential surface 5-1 of the rotating shaft 5, and the rod tip 12-2, which is the tip of the cylinder 12, is formed into a substantially spherical protruding surface. -2 is fitted into a spherical recess 13-2 provided inside the base 13-1 of a swing cylinder 13 fixed to the inner surface of the iron body 9 to make the iron body 9 swingable; 12 allows the iron body 9 to move forward and backward.

The swinging cylindrical body 13 surrounds the outer circumference of the hydraulic cylinder 12, and its outer shape expands in a tapered shape from the base end 13-1 toward the distal end 13-3. , the tip 14-1 of the cylinder 14 overlaps 15 from the outside, and the outer peripheral surface of the swinging cylinder tip 13-3 and the inner peripheral surface of the cylinder tip 14-1 are in contact with each other. There is.

The cylindrical body 14 surrounds the hydraulic cylinder 12, and has a tapered outer shape that expands from the distal end 14-1 to the proximal end 14-2.
2 is fixed to the outer circumferential surface 5-1 of the rotating shaft, and the swinging cylinder 13 slides back and forth inside the cylinder 14 by the expansion and contraction of the hydraulic cylinder 12.

Therefore, when the iron body 9 applies excavated soil to the inner wall surface of the prepared hole 8 by the rotation of the rotating shaft 5, the overlap portion 15 of the swinging cylinder 13 and the cylinder 14 is caused by the resistance applied to the iron body 9. is bent, and the outer circumferential surface of the swinging cylinder tip 13-3 and the inner circumferential surface of the cylinder tip 14-1 exert strong pressure on each other, causing a strong frictional force to act on the swinging cylinder 13 and the cylinder. The trowel body 14 locks with the iron body 9 to protect the hydraulic cylinder 12 by supporting the lateral load applied to the iron body 9, and also covers the cylinder 12 with the swinging cylinder 13 and cylinder 14 to remove sand and gravel from the excavated soil. The cylinder is protected from

Note that when moving the iron body 9 forward or backward, the lock between the swinging cylinder 13 and the cylinder 14 is released by slightly rotating the rotating shaft 5 in the opposite direction, so that the hydraulic cylinder 12 is not extended or retracted. Iron body 9
can be operated forward and backward.

Note that the protective structure according to the present invention may have the following shapes.

FIG. 4 shows a cylindrical body 14 with a sawtooth locking part 16 on the inner peripheral surface, and the iron body 9 is coated with excavated soil on the inner wall surface 8-1 of the pilot hole 8. When it is inserted, a lateral force acts due to the resistance of the excavated soil, and this lateral force is used to engage the sawtooth-shaped locking portion 16 formed on the inner peripheral surface of the cylindrical body 14 and the swinging Cylinder 1
By engaging the outer periphery of the lower end of the iron body 9 and supporting the force in the retraction direction of the iron body 9, the lateral force applied to the iron body 9 and the force in the forward and backward direction are absorbed by the locking part 16.
This allows the load on the hydraulic cylinder to be reduced.

FIG. 5 shows the swinging cylinder 13 overlapping the cylinder 14 from the outside.

According to this invention, by bendably overlapping the swinging cylinder and the cylinder, which are respectively fixed to the iron body and the rotating shaft and which surround the hydraulic cylinder, the horizontal This has the effect of supporting the directional load and protecting the hydraulic cylinder from sand and gravel in the excavated soil, thereby preventing damage to the cylinder.

[Brief explanation of the drawing]

Figure 1 is an overall side view of a pile driving device having a hydraulic cylinder protection structure for advancing and retracting the iron body according to the present invention;
The figure is a side view of the same essential parts, FIG. 3 is a sectional view of FIG. 2, and FIGS. 4 and 5 are other embodiments. 5: Rotating shaft, 5-1: Outer peripheral surface, 8: Prepared hole, 8
-1: Same inner wall surface, 9: Trowel body, 12: Hydraulic cylinder, 12-1: Same base end, 12-2: Same tip, 1
3: Swinging cylinder, 13-3: Same tip, 14: Cylindrical body,
14-1: same tip, 15: overlap part.

Claims (1)

[Scope of claim for utility model registration] A pilot hole 8 for pile driving is drilled, and the inner wall surface 8 of the pilot hole 8 is
- Pile driving device A designed to fill in the excavated soil of 1
In this, a telescopic hydraulic cylinder 12 is protruded from the outer peripheral surface 5-1 of the rotary shaft 5 for drilling the pilot hole 8 for pile driving, and the inner wall surface of the pilot hole 8 is attached to the tip of the cylinder 12. A trowel body 9 for applying excavated soil is swingably connected to the cylinder 8-1, and the cylinder 14 is attached to the rotating shaft outer peripheral surface 5 so as to surround the outer periphery of the base end 12-1 of the cylinder 12.
-1, and the tip 1 of the cylinder 12.
2-2 The swinging cylinder 13 is fixed to the iron body 9 so as to surround the outer periphery, and the tip 14-1 of the cylinder 14 and the tip 13-3 of the swinging cylinder 13 are bent freely. Hydraulic cylinder protection structure for advancing and retracting the iron body of the rotating shaft of the pile driving device, which is formed by overlapping 15.