JPS60253621A - Drop hammer for driving pile - Google Patents

Abstract

PURPOSE:To prevent the breakage of a foundation pile by providing a ventilating path through which sliding parts moving on the inner face of the cylinder of a striker and a pile head supporter of a bun-form are led to each other to the striker. CONSTITUTION:When the hammer ram 4 is dropped into a cylinder 1 under its own weight, an anvil 9 is struck through a hard wood 23 by the ram 4. When the insert part 17 of the anvil 9 is pushed into the striker body 8, the body 8 is pushed down to strike a foundation pile A. Since the hollow (a) of the foundation pile A is led through a hole 7a and a ventilating path 16 to a trench 14, the air in the hollow (a) is allowed to escape into the trench 14 each time the hammer is operated. Air in the pile A can thus be allowed to escape through the ventilating path of the striker each time hammer is operated, breakage of the pile can be prevented, and noise can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a pile driving mud and hammer used for constructing foundation piles and the like.

[Technical background of the invention and its problems]

Foundation piles are usually made of concrete and have a hollow shaft structure, so when they are driven with a hammer, the air inside the hollow part of the foundation pile is compressed with each impact of the hammer.

Concrete foundation piles could be damaged due to this compression. Therefore, in the past, the gear of the door hammer and the F-shaped bed head support member were fitted with some play (allowable) against the pile head. This play makes it easier for the air inside the foundation pile to escape to the outside with each strike of the hammer.

However, in such a conventional structure, since the pile head easily moves during impact, there is a problem in that the head of the pile collides with the iron pile head support member and generates a large noise.

Further, a drag hammer is a hammer ram that falls under its own weight inside a cylinder, and drives piles by applying pressure to a striking body to which a pile head support member is attached. However, as the hammer ram falls, the impact noise caused by it hitting the striking body is compressed and pushed downward as the hammer ram falls, and is emitted to the outside through the lower end opening of the cylinder, resulting in sudden impact noise. It was being emitted along with the am air flow. For this reason, conventional drop drills for driving piles have the drawback of being noisy.

[Purpose of the invention]

Therefore, an object of the present invention is to provide a drop hammer for driving piles that can prevent damage to foundation piles and reduce noise.

[Summary of the invention]

The present invention provides a striking body which is movable up and down and which receives pressure when the hammer ram falls, on the lower end side of a cylinder housing a hammer ram that is allowed to fall under its own weight so as to be movable up and down. In a pile driving drlag hammer equipped with a pile head support member for supporting a pile head, an air passage communicating between a sliding portion of the striking body that slides on the inner surface of the cylinder and the inside of the cap-shaped pile head support member, It is characterized in that it is provided on the above-mentioned striking body.

According to this hammer, the inner cavity of the foundation pile is connected to the ventilation path through the inside of the carrier and F-shaped pile cap support member, so when the foundation pile is struck by the hammer, the air inside the foundation pile is struck through the ventilation path. It can be released between sliding parts of the body. This prevents the foundation pile from being damaged due to an increase in air pressure inside the foundation pile.In addition, the airflow that is compressed and pushed downward as the hammer ram falls is caused by the sliding of the striking body. Between the moving parts, it collides with the air flow escaping from the ventilation passage. As a result, the force of the downward air flow can be reduced and the air can be discharged slowly through the lower end opening of the cylinder while suppressing rapid expansion of the tab, thereby suppressing noise.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to the drawings.

In the figure, reference numeral 1 denotes a cylindrical cylinder, and a sliding arm 2 is protruded from the outer peripheral surface of the cylinder and is slidably guided by an end (not shown) that stands on the ground. A striking body 3 is located on the lower end side of the cylinder 1.
A hammer ram 4 is slidably fitted into the cylinder 1 and is housed within the cylinder 1 so as to be movable up and down.

The striking body 3 is struck by the fall of the hammer ram 4, and is able to move up and down with respect to the cylinder 1 due to this striking force. A square-shaped pile cap support member 5 is removably attached to the lower end side of the striking body 3 via a plurality of bolts 6.
This member 5 is adapted to fit into the pile head of a concrete foundation pile and support this pile A. In addition, when driving a steel pile, it goes without saying that a chuck-shaped pillow head support member is attached to the striking body 3. In order to further reduce noise, in this embodiment, the pile cap support member 5 is made by injecting and filling a sound-reducing material 5a such as raw rubber in a liquid state between an inner cylinder and an outer cylinder made of iron plates. It has a solidified structure, and 7 in the figure is a pile cap damage prevention plate made of hard water material or the like. A through hole 7a is formed in the center of the prevention plate 7.

The striking body 3 includes, for example, a striking body main body 8 and γ.

It is equipped with a cabinet 9 and a seal lid 10.

The striking body 8 is an integrally formed forged product, and an annular cylinder receiving plate 11 is attached to the lower part of the striking body 8, with which the lower end surface of the cylinder 1 approaches and separates. A sliding portion 12.13 is formed on the striking body body 8 above the receiving plate 11 to slide on the inner surface of the cylinder 1. The sliding parts 12 and 13 are, for example, flanged, and an annular groove 14 is formed on the outer periphery of the striking body body 8 between them. At the lower end of the cylinder 1 is a double tank moving part 12. A plurality of stops 15 are installed between the ISs, and the striking body 43 can move up and down within the range where the stopper 15 and both tank moving parts 12.18 come into contact. Furthermore, the striking body main body 8 includes:
A ventilation path 16 is formed that communicates between the two tank moving parts 12 and 13 and the inside of the pile cap support member 5.

Further, the straight insertion portion 17 of the anvil 9 is inserted into the striking body body 8 so as to be movable up and down, and a medium enclosure chamber 18 is formed between this and the inner cavity of the striking body body 8. A pressure accumulating medium such as petroleum-based hydraulic oil is sealed in this sealed chamber 18 at a predetermined pressure. In addition, in the figure, 19 is a cylindrical metal that forms the sliding surface of the insertion part 17, 20 is an air vent hole, 2 is a medium filling hole, and 22 is connected to a sensor (not shown) that detects the pressure inside the medium enclosure chamber 18. This passage 22 is airtightly closed as a passage for the electric wire. A hard water material 23 is attached to the upper surface of the anvil 9, and the anvil 9 is lowered through the hard water material 23.
It is now under pressure. Further, the seal lid 10 is bolted to the upper surface of the striking body body 8.

The upper end of the cylinder 1 is closed with an end plate 24.
A hydraulic pressure expanding cylinder 25 is attached to 4 in a downward direction.

The lower end of the piston rod 26 connected to a piston (not shown) in the cylinder 250 is connected to the hammer ram 4.

The piston lower chamber and the piston upper chamber in the cylinder 25 are communicated with the hydraulic pump via a switching valve via an upper outer passage and a lower passage, and are also connected to the lower passage from the upper passage to the lower passage. They are connected by an electromagnetic one-way valve that allows hydraulic oil to flow only in the opposite direction. By filling the lower chamber of the piston with hydraulic oil and discharging the hydraulic oil from the upper chamber of the piston, the hydraulic cylinder 26 is opened.
The hammer ram 4 can be lifted up, and the hydraulic oil in the upper chamber of the piston is discharged and filled into the upper chamber of the piston through the electromagnetic one-way valve, thereby making it possible to rapidly drop the hammer ram 4. Inflow and outflow of hydraulic oil to and from the hydraulic cylinder 25]
By switching the
When it falls inside, the ram 4 hits the anvil 9 through the hard water material 23.

Then, the insertion portion 12 of the anvil 9 is pushed into the striking body body 8 and compresses the pressure-accumulating medium in the medium enclosure chamber 18, so that this medium pushes down the striking body body 8 in an attempt to release compression energy. Therefore, the foundation pile A is struck by the striking body 3. Next, after the hammer ram 4 is raised, it is lowered again by its own weight, and the foundation pile A is driven in as described above, and the pile driving is performed by repeating the above steps. In the above pile driving, the foundation pile The inner space a of the chamber has through holes 7&
Since it is communicated with the groove 14 via the ventilation path 16, the air in the inner space a escapes into the groove 14 every time the hammer strikes. Therefore, it is possible to prevent the air in the inner space a from being compressed and damaging the foundation pile due to the internal pressure.

At the same time, the airflow that is compressed and pushed downward as the hammer ram 4 falls carries the impact noise generated between the hammer ram 4 and the anvil 9. The upward airflow exiting from 16 meets within groove 14. For this reason, 1. The force of the downward airflow can be reduced, after which the downward airflow is discharged through the lower end opening of the cylinder 1.

Therefore, the downward airflow can be released while suppressing rapid expansion. Moreover, by providing the air passage 16 as described above, there is no need to release the air in the inner space a from the lower end opening of the pillow head support member 5.

Therefore, there is no need for a large amount of play between the pile cap and the inner surface of the pile cap support member 5, so that the movement of the pile cap can be suppressed and the noise from the pile cap support can be suppressed. In other words, for these reasons, it is possible to obtain a pile driving hammer with reduced noise. Although the above embodiment is configured as described above, in the present invention, the mechanism for raising and lowering the hammer ram is The winch is not limited to the hydraulic cylinder type described above, but may also be a hydraulic or engine type winch provided on the vehicle body side or the ground side of the crane.

Further, in the above embodiment, the striking body main body is formed of one member, but it may be formed by connecting a plurality of members.

Further, in the above embodiment, only one ventilation path is provided, but a plurality of ventilation paths may be provided.

In addition, in carrying out the present invention, the specific structure, shape, position, material of the cylinder, hammer ram, striking body, sliding part, bedhead support member, ventilation passage, etc. shall be limited to the extent that it does not go against the gist of the invention. It goes without saying that the sake brewer is not limited to the one embodiment described above, and can be configured and implemented in various ways.

〔Effect of the invention〕

Since the present invention described above has the configuration described in the claims above, the air inside the foundation pile can be released through the ventilation path of the striking body every time the hammer strikes, thus preventing damage to the foundation pile. can. Moreover, the airflow flowing into the cylinder from the air passage reduces the force of the downward airflow inside the cylinder, suppressing the sudden expansion of the downward airflow and releasing it from the cylinder, reducing noise. There are other effects.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, in which FIG. 1 is a partially sectional side view, and FIG. 2 is an enlarged sectional view of essential parts. , 4... Hammer ram, 5... Pile head support member, 12.13... Sliding part, 16... Ventilation path, A... Foundation pile, a... Inner space.

Claims (1)

[Claims] A hammer ram that is allowed to fall under its own weight is housed in a cylinder that can be moved up and down, and a striking body that can be moved up and down is installed on the lower end of the cylinder that is movable up and down when the hammer ram falls. In a drop hammer for piling driving equipped with a pile head support member that supports a pile head, an air passage is provided that communicates between the sliding portion of the impacting body that slides on the inner surface of the cylinder and the inside of the cap-shaped pile head support member. A drop hammer for driving piles, characterized in that it is provided on the above-mentioned impacting body.