JP2000199393A - Excavating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To absorb and damp hammering noise of an air hammer during excavating work to reduce noise to a minimum by charging sound absorbing material in a space part between the air hammer and a casing. SOLUTION: A support ring 14 having a clearance to the outer peripheral surface of a hammer body 8a is fastened to the inner peripheral surface lower end of a casing 7 for a hammer. A partition wall 15 surrounding the body 8a is disposed between the support ring 14 and a holding plate 9b of the casing 7, and sound absorbing material 16 is charged in a space part between the outer peripheral surface of the partition wall 15 and the inner peripheral surface of the casing 7. A synthetic resin foam body, unwoven fabric, or the like is used as the sound absorbing material 16, and impact sound is absorbed and damped by a large number of air layers and resiliency. Storing hammering noise generated by the drive of the hammer 8 during excavating work are therefore absorbed and damped by the sound absorbing material to reduce noise. Work environment is therefore improved to avoid noise pollution around a construction site.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an excavator in which an air hammer is rotatably driven in a casing, and the ground is excavated by a rotary impact action of the air hammer.

[0002]

2. Description of the Related Art FIG. 6 shows a main part of a conventional excavator of this type. In this figure, Ko denotes a hammer casing in which an air hammer H is rotatably driven.
Kn is a connection casing connected to the upper end of the hammer casing Ko, and inside the connection casing Kn,
A hollow rod R for rotation transmission and air supply is inserted and arranged, and a female joint Ja on the rod R side and a male joint Jb on the air hammer H side are pin-connected. The upper end of the hollow rod R is connected to a rotary drive unit, and air is supplied to the rod R via an air swivel mechanism, and the ground is excavated by the rotary hammer action of the air hammer H.

[0003]

By the way, in this type of excavator, during the excavation work, the impact sound of the air hammer H resonates in the space S between the air hammer H and the hammer casing Ko, and the excavation work becomes large. There is a problem that noise is generated, the working environment is deteriorated, and noise pollution is caused around the site.

[0004] In view of the above, it is an object of the present invention to provide an excavator capable of absorbing and attenuating the impact sound of an air hammer during excavation work to reduce and mitigate the noise as much as possible.

[0005]

The invention according to claim 1 is
In an excavator in which an air hammer 8 is provided in the casing 7 or 17 and the ground is excavated by the rotary impact action of the air hammer 8, a sound absorbing material 16 or a space is provided in a space between the air hammer 8 and the casing 7. 26 is loaded.

According to a second aspect of the present invention, in the excavator according to the first aspect, a hollow portion between the air hammer 8 and the casing 7 and an air supply hollow rod 10 connected to an upper end of the air hammer 8 and the casing. A sound absorbing material 16 or 26 is loaded in a space between the sound absorbing material 6 and 17 respectively.

According to a third aspect of the present invention, in the excavator according to the first or second aspect, a cylindrical partition wall 15 is formed in the casing 7 or 17 so as to form a slight gap between the outer peripheral surface of the hammer body 8a. The sound absorbing material 16 is mounted between the outer peripheral surface of the cylindrical partition wall 15 and the inner peripheral surface of the casing 7 or 17.

According to a fourth aspect, in the excavator according to the first or second aspect, the inner peripheral surface of the casing 7 and the hammer body 8 are provided.
The sound-absorbing material 16 or 26 is directly loaded between the outer peripheral surface and the outer peripheral surface.

[0009]

FIG. 1 shows the whole of an excavator. In this figure, reference numeral 1 denotes a leader, which is held in a vertical posture by a back stay 3 extended from a traveling vehicle 2. Reference numeral 4 denotes a rotary drive device which is supported so as to be able to move up and down along the reader 1 and is suspended by a wire 5 for moving up and down. A connecting casing 6 is rotatably suspended at the lower end of the rotary drive device 4, and a hammer casing 7 is connected to a lower end of the casing 6. An air hammer 8 is inserted into the casing 7. ing. The connection casing 6 includes, for example, two upper and lower casings connected to each other.

As shown in FIG. 2, the hammer casing 7 is held by the air hammer 8 via holding plates 9a and 9b so as to be integrally rotatable. As shown in FIG. 3, the connection casing 6 is provided with holding plates 11a and 11b and 12a and 1a.
It is held rotatably with the hollow rod 10 for rotation transmission and air supply via 2b. The male joint Jb on the side of the air hammer 8 is fitted and pin-coupled to the female joint Ja provided at the lower end of the hollow rod 10, and the male joint Jb at the upper end of the hollow rod 10.
Is fitted to the female joint Ja at the lower end of the upper connection casing 6 and is pin-connected, and the male joint (not shown) at the upper end of the upper connection casing 6 is interlocked with the rotary drive 4. Are linked. The supply of air from the air supply source (air compressor) to the inside of the hollow rod 10 is performed through an air swivel mechanism 13 (see FIG. 1).

The internal structure of the air hammer 8 is omitted because it is well known, but a piston that slides in a cylinder provided inside the hammer body 8a is a hollow rod for rotation transmission and air supply. The hammer piston reciprocates by compressed air supplied through the hammer body 10, and the hammer piston 8b projects into the lower part of the hammer body 8a.
Is to be hit. The air hammer 8 rotates with the casings 6 and 7 by the rotation of the hollow rod 10. Therefore, the air hammer 8 excavates the ground by the rotary impact action of the excavation bit 8b as described above, and the excavated soil and the like are removed by the excavation bit 8b.
The air blown out from the air blowing hole at the tip blows up and discharges the space between the casing 7 and the inner wall of the borehole.

As shown in FIG. 2, at the lower end of the inner peripheral surface of the casing 7 for the hammer, a support ring 14 having a slight gap between itself and the outer peripheral surface of the hammer body 8a is fixed. A cylindrical partition wall 15 surrounding the hammer body 8a is disposed between the holding plate 9b at the upper end of the casing 7 and the outer peripheral surface of the partition wall 15 and the casing 7.
The sound absorbing material 16 is loaded in a space between the inner peripheral surface of the sound absorbing member and the sound absorbing member 16. A slight gap is formed between the inner peripheral surface of the cylindrical partition wall 15 and the outer peripheral surface of the hammer body 8a.

As the sound absorbing material 16, synthetic resin foam, nonwoven fabric, felt and the like are generally used. In particular, as the foam, a polyolefin resin such as a polyethylene resin, a polypropylene resin, and an ethylene-vinyl acetate copolymer, or a polyurethane resin (compressed urethane) is preferable, and the impact sound is generated due to a large number of air layers and elasticity of the resin. Can be absorbed and attenuated. In the case of a synthetic resin foam, a sheet-shaped material may be bent into a cylindrical shape and pushed into the space, or a chip-shaped material may be loaded into the space, or may be in a molten state. The foaming synthetic resin may be loaded by so-called in-situ foaming in which the foamable synthetic resin is directly injected into the space and foamed. In a space between the hammer casing 7 shown in FIG. 2 and the cylindrical partition wall 15 disposed inside the casing, a sound absorbing material 16 made of, for example, a chip of a synthetic resin foam is loaded. still,
The casings 6 and 7 (or the casing 17 described later)
Since the welding operation may be performed on the hollow rod 10 and the maintenance work, the synthetic resin foam is preferably flame-retardant.

As shown in FIG. 3, the sound absorbing material 1 is provided in each connection casing 6 in a space between the outer peripheral surface of the hollow rod 10 for rotation transmission and air supply and the inner peripheral surface of the casing 6.
6 are loaded. As the sound absorbing material 16, various kinds of materials as described above can be used. The sound absorbing material 16 made of, for example, a chip of a synthetic resin foam is loaded in this space.

As described above, the sound absorbing material 16 is loaded into the space between the inner peripheral surface of the hammer casing 7 and the outer peripheral surface of the hammer main body 8a, so that the air hammer 8 can be hit by the striking action during excavation work. The generated intense striking sound is absorbed and attenuated by the sound absorbing material 16, so that the noise is reduced and alleviated. Further, the impact sound of the hammer 8 propagates through the hollow rod 10 to the connection casing 6 side, and resonates in its internal space to easily generate noise outside. However, as shown in FIG. The sound absorbing material 16 is also loaded in the space between the hollow rod 10 and the striking sound propagating to the connection casing 6 side through the hollow rod 10 is absorbed and attenuated by the sound absorbing material 16 to reduce and reduce noise. It is supposed to be.

Further, in the above-mentioned hammer casing 7, a cylindrical partition wall 15 is formed inside the casing 7 so as to form a slight gap between the outer peripheral surface of the hammer body 8a and the outer peripheral surface of the cylindrical partition wall 15. Since the sound absorbing material 16 is loaded between the casing and the inner peripheral surface of the casing 7,
The vibration of the hammer body 8a caused by the operation of the air hammer 8 is prevented from being transmitted to the partition wall 15, and the expansion of the vibration sound can be suppressed. In addition, the air hammer 8 is removed from the hammer casing 7 due to the breakage of the excavation bit 8b. In this case, there is an advantage that the hammer 8 can be easily taken out and the sound absorbing material 16 can be easily loaded.

The hammer casing 7 shown in FIGS. 1 and 2 is a case of a short hammer casing 7 having a relatively short casing length. FIG. 4 shows an air hammer 8.
1 shows a long hammer casing 17 having the same length and a relatively long casing length. In the long hammer casing 17, a holding plate 9c is provided at an intermediate portion in the casing length direction in the casing 17, and a slight hammer body 8a is provided between the holding plate 9c and the support ring 14 at the lower end of the casing 17. A cylindrical partition wall 15 is provided which is surrounded by a gap, and a sound absorbing material 16 is loaded in a space between the outer peripheral surface of the partition wall 15 and the inner peripheral surface of the casing 7. The sound absorbing material 16 is loaded between the hollow rod 20 for air supply and rotation transmission extending upward from the upper end of the main body 8a and the inner peripheral surface of the casing 17.

Therefore, in the case of such a long hammer casing 17, the sound absorbing material 16 is loaded between the inner peripheral surface of the casing 17 and the hammer body 8a and the hollow rod 20, so that air during the excavation work is provided. The intense striking sound generated by the striking of the hammer 8 and the striking sound propagating to the upper side of the casing 17 through the hollow rod 10 are absorbed and attenuated by the sound absorbing material 16, so that the noise can be reduced and reduced. The male joint Jb at the upper end of the hollow rod 20 is fitted to the female joint Ja of the hollow rod 10 on the connection casing 6 side and is pin-connected.

FIG. 5 has the same internal structure as the hammer casing 7 shown in FIG. 2, but does not have the partition wall 15 as in the case of the casing 7, and has an outer peripheral surface of the hammer body 8a and the hammer main body 8a. A case in which a sound absorbing material 26 made of a synthetic resin foam, a nonwoven fabric, a felt, or the like formed in a sheet shape is loaded in a space between the inner peripheral surface of the casing 7 and the sound absorbing material 26 in a cylindrical shape. This cylindrical sound absorbing material 26
Fix its inner peripheral surface to the outer peripheral surface of the hammer body 8a,
It is loaded so as to form a slight gap between the outer peripheral surface of the cylindrical sound absorbing material 26 and the inner peripheral surface of the casing 7.

In the case 7 of the hammer casing, a chip, a non-woven fabric, a felt or the like of synthetic resin foam is provided between the outer peripheral surface of the hammer body 8a and the inner peripheral surface of the casing 7 without providing the partition 15 inside. May be loaded.

In this embodiment, the hollow rods 10 and 20 for rotation transmission and air supply are used. However, only the supply of air is performed by the hollow rods 10 and 20, and the rotation drive of the air hammer 8 is performed as follows. The rotation may be performed via casings 6, 7, and 17 that are integrally rotatably connected to the air hammer 8 and are linked to the rotation driving device 4. Further, the casings 6, 7, 17 may not be driven to rotate, and only the air hammer 8 may be driven to rotate.

[0022]

According to the first aspect of the present invention, since the sound absorbing material is loaded in the space between the air hammer and the casing, a violent impact sound generated by the impact of the air hammer during excavation work. Absorbed by sound absorbing material
Attenuation can reduce and mitigate noise, thereby improving the working environment and avoiding the occurrence of noise pollution around the site.

As described in the second aspect, the space between the air supply and rotation transmitting hollow rod connected to the upper end of the air hammer and the casing together with the space between the air hammer and the casing. However, if a sound absorbing material is loaded, the impact sound transmitted by the hollow rod is absorbed by the sound absorbing material.
Since it can be attenuated, it is more effective.

According to a third aspect of the present invention, a cylindrical partition which forms a slight gap between the outer peripheral surface of the hammer body and the outer peripheral surface of the cylindrical partition and the inner peripheral surface of the casing are provided in the casing. When a sound-absorbing material is loaded between the surface and the surface, the vibration of the hammer body due to the operation of the air hammer is prevented from being transmitted to the partition wall, and the expansion of the vibration sound can be suppressed,
When the air hammer is removed from the hammer casing due to breakage of the hammer drill bit, the hammer can be easily taken out and the sound absorbing material can be easily loaded.

In the case where the sound absorbing material is directly loaded between the inner peripheral surface of the casing and the outer peripheral surface of the hammer body, the structure inside the casing is simplified and the production is easy. Becomes

[Brief description of the drawings]

FIG. 1 is a side view showing an entire excavator.

FIG. 2 is a sectional view showing an internal structure of a hammer casing side.

FIG. 3 is a cross-sectional view showing an internal structure on a connection casing side.

FIG. 4 is a sectional view showing an internal structure of a long hammer casing.

FIG. 5 is a cross-sectional view showing an internal structure of a hammer casing side, in which a sheet-shaped sound absorbing material is loaded in a cylindrical state.

FIG. 6 is a sectional view showing an internal structure of a conventional hammer casing.

[Explanation of symbols]

 Reference Signs List 6 Casing for connection 7 Casing for hammer 8 Air hammer 8a Hammer body 8b Drilling bit 10 Hollow rod for air supply 15 Partition wall 16 Sound absorbing material 17 Casing for hammer 20 Hollow rod for air supplying 26 Sound absorbing material

Claims (4)

[Claims] 1. An air hammer is provided in a casing,
An excavator for excavating the ground by a rotary impact action of an air hammer, wherein a sound absorbing material is loaded in a space between the air hammer and a casing. 2. A sound absorbing material is loaded into a space between an air hammer and a casing and a space between a casing and an air supply hollow rod connected to an upper end of the air hammer. The excavator according to claim 1, characterized in that: 3. A sound-absorbing material is provided between the outer peripheral surface of the cylindrical partition and the inner peripheral surface of the casing. The excavator according to claim 1 or 2, wherein the excavator is loaded. 4. The excavator according to claim 1, wherein a sound absorbing material is directly loaded between an inner peripheral surface of the casing and an outer peripheral surface of the hammer body.