JPS59165729A - Pile driver - Google Patents

Abstract

PURPOSE:To reduce noise during the pile driving period by a method in which a skirt to cover the periphery of the upper end of a pile is formed below a pile striker, and the skirt is supported on the periphery of the pile through an elastic material. CONSTITUTION:When compressed air is set into an inlet 18, the air coming into the lower operating chamber 13 enters the upper operating chamber 15 through paths 16 and 17, a piston 9 is lowered, and the bottom 5a of the recession 5 of a cap 2 is struck by the striker 19 to drive a steel tubular pile 1. Since the striking position is positioned in the inside of the cap 2 and the skirt 20 is supported through an elastic material to prevent the rocking movement, noise is reduced because the recession 5 and the skirt 20 serve as sound-proof cover.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a pile driving device mainly used for reinforcing the ground of a house.

As a pile driving method for improving the ground of houses, a pile driving device equipped with a cylinder and a piston is attached to the top end of a steel pipe pile, and compressed air is sent into the cylinder to cause the piston to reciprocate.
A device for driving piles using this method is well known (Japanese Patent Application Laid-open No. 5
5-26340). Compared to methods using Monken or diesel hammers, this kind of pile driving device does not require large-scale equipment and is suitable for construction work in narrow sites such as residential areas. is often carried out in urban areas, and has the disadvantage that noise is often a problem. The present invention was made for the purpose of reducing noise in such pile driving equipment,
As its configuration, the present invention is attached to the upper end of the pile, and
It consists of a pneumatic or hydraulically operated striking device equipped with a cylinder and a piston, and a camp that is also attached to the upper end of the pile and receives the striking force, and forms a skirt that extends downward from the striking device and covers the outer periphery of the upper end of the pile. In addition, this skirt portion is supported by the outer periphery of the pile via an elastic member.

The apparatus of the present invention will be explained below based on an illustrated embodiment. In the figure, (1) is a steel pipe pile that is driven into the ground, and at the upper end of this steel pipe pile (1) is a steel pipe made by &I. Camp (2) is inserted and installed.

This cap (2) includes an insertion part (31) inserted into the upper end of the steel pipe pile (1) and a flange part (31) that is integrally formed with the upper end of the insertion part (3) and abuts on the upper end of the steel pipe pile (1). 4)
A circular recess (5) is formed vertically downward from the upper surface. Further, this circular recess (5) has an air vent hole (6) penetrating through it from its bottom surface (5a) to the bottom side of the insertion portion (3).

On the other hand, (7) is a striking device consisting of a cylindrical cylinder (8) with an open lower end and a piston (9) inserted into this cylinder (8), and the piston (9) has a main body ( 10) A large diameter portion (11) is formed on the outer periphery of the upper end, and the outer circumferential surface of this large diameter portion (11) is in sliding contact with the inner wall surface of the cylinder (8). Further, an annular protrusion (12) is provided on the inner wall surface of the cylinder (8) below the piston large diameter portion (11).
) is formed, and the main body (10) of the piston (9) comes into sliding contact with the inner surface of this annular protrusion (12), and a space is formed between the piston large diameter part (11) and the annular protrusion (12). The space between the top surface of the piston (9) and the ceiling surface (14) of the cylinder (8) is defined as a lower working chamber (15).

Furthermore, the piston (9) has a transverse passage (16) extending diametrically through its body (10) and a transverse passage (16) extending diametrically through its body (10).
A vertical passageway (17) is formed that penetrates from the middle of 16) toward the upper working chamber (15). The peripheral wall of the cylinder (8) has an inlet (
18) is formed. In addition, the piston (9) has
The main body (10) is integrally formed with a small-diameter striking portion (19) that protrudes downward from the bottom.
) When the lower end is inserted into the fourth part (5) formed in the camp (2) and the piston (9) descends, the striking part (19
) is adapted to strike the bottom surface (5a) of the recess (5). At this time, the corner (5b) of the entrance of the recess (5) is formed into a rounded shape so that the piston striking part (19) can easily enter therein. Furthermore, the skirt portion (20) extending downward from the cylinder (8) is connected to these camps (2).
and is placed on the outside of the upper end of the steel pipe pile (1) so as to cover the outer periphery of the upper end of the steel pipe pile (1). As shown in FIG. 3, the lower end of this skirt portion (20) has a plurality of bolts (21
) (21)... are arranged at appropriate intervals in the circumferential direction, and inside the skirt portion (20), these bolts (21) (21) have a spring receiver (22) at the tip.
(22)...A spring (
23) (23)...The other end comes into contact with the outer peripheral surface of the steel pipe pile (1), and the skirt part (2o) sways, causing the steel pipe pile (
11 is prevented.

Now, in the drawings, Fig. 1 shows a state in which the piston (9) is raised, and Fig. 2 shows a state in which the piston (9) is similarly descended. 17), the lower working chamber (13) and upper working chamber (15) communicate with each other, and therefore, at this stage, the inlet (
When compressed air is sent from the lower working chamber (13)
One air enters each of these passages (16) (17)
It enters the upper working chamber (15) through the piston (9
) is lowered, and the striking part (19) inserted into the recess (5) of the camp (2) strikes the bottom surface (5a) of the recess (5), thereby driving the steel pipe pile (1). In this way, when the piston (9) descends and hits the steel pipe pile (fl), as shown in FIG.
16) is located below the annular protrusion (12) of the cylinder (8), therefore, the lower working chamber (13) and the upper working chamber (
15) is closed and thus the inlet (18)
The compressed air sent in is supplied only to the lower working chamber (13) to raise the piston (9), and while repeating this reciprocating motion, the steel pipe pile (1) is driven into the ground. .

In the above, if the diameter of the air bleed hole (6) is too large, the strength of the bottom of the recess (5) will be insufficient, while if it is too small, there is a risk that the camp (2) will be lifted up when the piston (9) rises. In the experiment conducted by the author, when the inner diameter of the recess (5) was 60 mm, the best result was when the inner diameter was 10.5 mm.

In addition, the stroke of the piston (9) at that time is approximately 15 m.
m, and the inner diameter of the steel pipe pile (1) was 100 mm.

In the above embodiments, it is explained that the actuator is actuated by compressed air, but the same effect can be obtained if the actuator is actuated by a liquid such as hydraulic pressure.

In the above embodiment, the striking part of the piston is inserted into the recess formed in the cap, and the striking part hits the bottom of the recess, so unlike the case where the upper surface of the camp is directly hit, the hitting point is Located inside the camp, these act as a soundproof cover and therefore reduce noise. In the present invention, the skirt also functions as a soundproof cover, whereas in the past, this skirt had the disadvantage of swaying and hitting the outer circumferential surface of the steel pipe pile, rather emitting noise. As mentioned above, since the skirt portion is supported via an elastic member such as a spring, this disadvantage is not present, and noise can be further reduced. Table 1 shows the noise levels compared between a conventional device that hits the top surface of the cap directly, a device that hits the bottom of the recess, and one that does not have a spring to support the skirt and one that has a spring. The table shows the measurement results, and as can be seen from the table, the one with the recess has a lower BIJ sound level of about 8 dBIJ compared to the one without.
It can be seen that with the support spring provided, the reduction is further reduced by 6 dB.

Margin below this page Table■

[Brief explanation of the drawing]

Figures 1 and 2 are longitudinal cross-sectional views of the upper end of a steel pipe pile, respectively, showing how the device of the present invention is used, and Figure 3 is
- It is an A line enlarged sectional view. (ll---Steel pipe pile, (2)-camp, (51-recess, (5a)-bottom, (7)--pile driving device, (8)
- Cylinder, (9) - Piston, (19) - Impact part, (20) - Skirt part, (23) - Spring (elastic member). Patent Applicant: Block House Co., Ltd. Representative Patent Attorney Hisashi Tarumoto

Claims (1)

[Claims] It consists of a pneumatic or hydraulically actuated striking device that is attached to the upper end of the pile and is equipped with a cylinder and a piston, and a camp that is also attached to the upper end of the pile and receives the striking force, and extends downward from the said striking device. A pile driving device characterized in that a skirt portion is formed to cover the outer periphery of the upper end, and the skirt portion is supported by the outer periphery of the pile via an elastic member.