JPS58106016A - Sound shielding device for pile driver - Google Patents

Abstract

PURPOSE:To visuablize the rise of a ram as well as suppress the rise of sound pressure in a sound proof wall by covering almost lower half part of a drop hammer body with a sound-proof wall having a specific opening on its upside. CONSTITUTION:The lower half part of a drop hammer H body is covered with a sound-proof wall 20 consisting of a sound shielding plate 20a, an air layer 20b, a double perforated plate 20c and a sound absorber 20d. An opening 24 is provided in the upside of the sound-proof wall 20, and the sound pressure of impaction produced by the collision between the long cap 2 of a ram 1 vertically moving by an oil-pressure cylinder 6 and a piston rod 7, determined by equations (1) and (2) and distance damping to the ground surface for its magnitude, escapes from the opening 24 to the open air, whereby suppressing rise of the sound pressure. When the ram rises, its rising amount can be confirmed because the ram 1 can be seen from the opening 24, and alos the size of the cooler for a power source can be miniaturized because air is flowed in from the opening 24 for cooling.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a soundproofing device for a pile driver configured to move a drop hammer main body up and down along a radius.

Single-force methods of drop hammer devices include hydraulic, pneumatic,
Although there are various types such as mechanical and electromagnetic types, the soundproofing device of the present invention can be applied to any of these types.

Drop hammer devices are generally axially elongated and
Because noise is generated from the part where the weight strikes the pile, i.e. from the lower part of the drop hammer body, the lower half of the drop hammer body is constructed with a sealed soundproof wall structure, and the upper end of the pile is sealed. A soundproofing device with a structure that is attached to the machine, or a soundproofing cover that tightly covers almost the lower half of the drophammer body and the upper end of the pile is placed on the outside of the drop hammer body, either fixedly or movable in the axial direction of the hammer. It is equipped with a soundproofing device woven into the structure.

In the above-mentioned soundproofing device, since the striking portion of the pile, which is the main noise source, is hermetically covered, the sound pressure level inside the soundproofing device is generally higher than when there is no soundproofing device. In order to reduce the amount of increase in sound pressure, measures have been taken to attach a sound absorbing material to the inner surface of a soundproof wall that constitutes a soundproofing device. This makes it possible to suppress the increase in internal sound pressure to some extent, but this amount of increase in sound pressure is generally said to be expressed by the following equation (1), and depends largely on the average sound absorption coefficient of the interior, and is At the given frequency, if a sound absorbing material such as glass wool with a sound absorption coefficient of about 0.7 is attached to the entire inner surface of a soundproof wall, the average internal sound absorption coefficient will be 0.3 degrees, but the average sound absorption coefficient will be even higher. In other words, it is desired to further reduce the increase in internal sound pressure.

Amount of sound pressure rise (dB) - (X+) i in the formula represents the average sound absorption coefficient inside the soundproof wall. This means that the amount of reduction can be increased.

In addition, since the soundproof wall has an airtight structure, the installer cannot visually observe the movement of the ram that drives the pile heads.In construction using a drop hammer device, the pile is driven depending on the hardness and softness of the ground. It is better to vary the setting speed. Generally, this is done while the pourer is controlling the height of the weight. When pile driving is proceeding smoothly, the height of the weight is automatically determined as automatic operation, and there is no need for the installer to visually check the height. In terms of pile construction management, it is often more convenient to perform construction while visually observing the height of the weight. Furthermore, since the soundproof wall has a closed structure, the air inside the soundproof wall is Therefore, if construction is carried out continuously over a long period of time, the balance temperature of the air inside the soundproof wall will gradually rise, and as a result, the drop hammer The heat balance temperature of the device's power source (for example, a hydraulic pump installed on the vehicle body) also rises. Therefore, in order to increase the cooling capacity of the power source to withstand this, the cooling device is also somewhat large.The present invention not only provides a soundproofing effect, but also allows the movement of the weight to
The object of the present invention is to provide a soundproofing device that allows the user to visually observe the noise.

An embodiment of the present invention in which the lower framework of the mass/drop hammer body is a framework of a soundproof wall body will be described with reference to FIGS. 1 to 4.

The upper framework 14 that constitutes the main body of the drop hammer device 1lIH consists of vertical columns 12 and cross beams 13 arranged at intervals in the circumferential direction of the drop hammer device H, and the lower framework 17 is also arranged in the same manner as the columns 12. It consists of pillars 15 and cross beams 16. A connecting portion 5 is provided at the upper end of the upper framework 14, and a cross beam 13 at the lower end of the upper framework 14 is connected to a hanging rod 11 # length that is raised and lowered by a winding net installed on the vehicle body. A shielding plate 25 is attached to the inner periphery of the hydraulic cylinder 6, and a hydraulic cylinder 6 and equipment for supplying power to the hydraulic cylinder 6 are fixed to the shielding plate 25. The piston rod 7 of the hydraulic sill 6 is connected to a weight 1 which uses its energy to drive the pile 4 when it falls.

Between each column 15 of the lower frame 17, there are a sound insulating plate 20a made of a soundproof and vibration isolating material (for example, a composite copper plate), a back space 20b serving as an air layer, and a perforated double internal and external perforated plate 20C1 made of steel or aluminum. A soundproof wall 20 is constructed of a sound absorbing material 20d such as glass wool filled between the plates 2OC,
In the upper part of the soundproof @20, openings 24 are provided at two locations symmetrical with respect to the center. In this embodiment, opening 2
4 is provided between the pillar 15 and the cross beam 16.

A pile cover 19 is fixed to the lower end of the soundproof wall 20, and a packing 21 made of an elastic material such as Gt rubber is installed inside the pile cover 19.
A long cap 2 is attached to the top end of the long cap 2, and a bush ring 3 made of wood or the like is attached to the upper end of the long cap 2. The gasket 21 is for transferring the weight of the hammer device main body and the soundproof wall 20 to the long cap 2. A ring-shaped gasket 22 for shielding the outer peripheral surface of the long cap 2 is provided on the lower end surface of the pile cover 19, and a ring-shaped gasket 22 is provided on the outer periphery of the upper frame 14 fixed by a ring 23 and the shielding plate 20m of the soundproof wall 20. A holding tool 8 for holding a guide rail 9 fixed in the vertical direction is attached to 4f10.

Pressure oil is supplied from a hydraulic power source (not shown) to the hydraulic cylinder Jf6 to raise the weight 1, and then the pressure oil is discharged and the weight 1 is dropped to drive the pile 4. At the same time as the casting, the drop hammer assembly 5 is lowered along the guide rail 9 by letting out the hanging rope 11.

This drop hammer device H has a soundproof wall 20 in almost the lower half of its main body, a pile cover 19 is provided at the lower end of the soundproof wall 20, and a shielding plate 25 is provided at the upper end. is provided. That is, if the soundproof wall 20, the pile cover 19, and the shielding plate 25 are all made up of the sealed wall 18, the sealed wall 18 has a sealed structure except for the opening 24. Therefore, the main noise from the lower part of the drop hammer device 5 during impact is significantly reduced, but due to the effect of the opening 24, the reduction in noise is expected to be even greater.

Here, referring to Figure tH5, the soundproof wall body 1B without the opening 24, the inside and outside of the soundproof wall body 18 with the opening 24,
Describe the noise level.

The soundproof wall 18 is elongated in the axial direction, and the main noise is generated in the lower part of the soundproof wall 18. The noise level in a conventional soundproof wall without an opening 24 is expressed as rupture*a inside the soundproof wall, and rupture IIao outside the soundproof wall near the hammer device (the same applies in the following explanation). Ru. In the diagram on the left side of FIG. 5, the horizontal axis represents the noise level and the vertical axis represents the height above ground. Near the sound source inside the soundproof wall, the sound pressure rises above the noise level of the main body. Note that the change in the noise level depending on the height position is due to distance attenuation.

In the soundproof wall 18 according to the present invention provided with the opening 24, the noise level is represented by a solid line b□ inside the soundproof wall, and as a solid line outside the soundproof wall. It can be expressed as In other words, the presence of the openings 24 inside the soundproof wall reduces the amount of increase in sound pressure, which reduces the noise level near the inside of the soundproof wall, and as a result, the noise level B affecting people on the ground is lower than that of the conventional one. It will be lower than case A.

The reason for the decrease in the sound pressure increase inside the soundproof wall is the above (1).
In the formula, the average sound absorption coefficient inside the soundproof wall body is
This result becomes larger due to the presence of .

In other words, the sound absorption walls inside the soundproof wall body have various sound absorption coefficients of 1 or less, but by providing the opening 24, there is no wall in this part, so the sound absorption coefficient in this part is It becomes 1. By providing such an opening 24, it is possible to obtain a wood-covered soundproof wall that has a sound absorption coefficient of this portion, which reduces the amount of noise compared to the conventional one.

Next, the size and position of the opening 24 will be described.

When the opening 24 is made larger, the noise level inside the soundproof wall becomes like chain * c, and the noise level outside the soundproof wall becomes like chain @c. That is, although the amount of increase in sound pressure within the soundproof wall further decreases, the direct sound from the openings conversely increases, so that the distance attenuation cannot be completed by the time the sound reaches the ground, and the noise level C on the ground actually increases. The noise level outside the soundproof wall at the opening is determined by the size of the opening (2) below.
) is the value obtained by subtracting the amount of transmission loss from the noise level inside the soundproof wall in this part.

(dH) ,...(2) Therefore, the size of the opening 24 is determined based on the dimensions of the soundproof wall, comprehensively considering formulas (1) and (b) and distance attenuation to the ground. .

In the embodiment described above, the opening is provided as a space in the lower framework 17, but if it is necessary to make it smaller based on the above consideration, the soundproof wall 20 may be enlarged to provide the opening 2.
Reduce the size of 4.

In addition, it is desirable that the opening 24 be located above the soundproof wall as much as possible.In addition, there is a provision that allows the opening 24 to be temporarily covered for the purpose of rain protection and dustproofing during rainy days or long-term storage. It is also possible to have a configuration having the following.

Figures 6 and 7 show another embodiment of the present invention in which an approximately hoe-shaped sound absorbing duct 42 made of a sound absorbing material and a perforated plate is provided in an opening 41 corresponding to the opening 24 described above. Indicates the mode. This construction has the simplest structure, and by increasing the sound absorption effect, it is possible to see through the inside of the building.

! Figure R8 and Figure 9 show other embodiments of the present invention in which a plurality of openings 43 are arranged side by side and a sound absorbing duct 44 in the form of a grid within the frame is attached to each opening [4143]. The noise reduction effect can be greater than that of the embodiment shown in Fig. 8 □ Figs. Another embodiment of the present invention is shown in which a duct 6 is attached, and the noise reduction effect can be further increased.

FIGS. 12 and 13 show another embodiment of the present invention in which a plurality of openings 47 are provided in the circumferential direction of the soundproof wall body 18, and a sound absorption duct 48 in the shape of a vertical frame vertical slit is attached to each opening. show. This embodiment is intended to further reduce the amount of sound pressure increase in equation (1), and allows for easy internal viewing.

14 and 15 show the drop hammer device ItH
Another embodiment of the present invention is shown in which substantially the lower half of the pile 4 and the upper end of the pile 4 are sealed with a soundproof cover 65 that is a soundproof wall body,
An opening 66 is provided in the upper part of the soundproof cover 65. In both figures, the same reference numerals as in FIGS. 1 to 4 represent the same or equivalent items.

61 is a cap that transmits the falling energy of the weight l to the pile 4, and 63 is a holding tool fixed to the main body of the drop hammer device H, which penetrates the soundproof cover 65.
The tS portion is configured elastically and hermetically. 6
A holding tool 4 is fixed to the main body of the drop hammer device H which is not surrounded by a soundproof cover 65, and grips the guide rail 9 together with other holding tools 63. The soundproof cover 65 is fixed to the support part 67 of the drop hammer device H via a cushion 68, and the lowermost part of the cover 65 can be opened and closed for erecting the pile 4 or for other purposes. It may be a structure.

16 and 17 show another embodiment of the invention in which a soundproof cover 711 with a guide rail 74 and an opening 72 are provided. In both figures, #! Figures 14 and 15
Items with the same reference numerals as in the figure represent the same or equivalent items.

The soundproof cover 71 seals the lower half of the drop hammer device H and the upper end of the pile 4, and is elastically placed on the support portion 67 of the drop hammer device #LH via a cushion 73. ing. A hanging rope 78 is connected to a connecting portion at the upper end of the soundproof cover 71 . The drop hammer assembly [H is movable in the axial direction relative to the guide rail 74. The drop hammer device H has a guide rail 74.
A holding tool 75 is fixed to hold the soundproof cup (-71
A holding tool 76 for gripping the guide rail 9 is fixed to the cage.
A holding tool 77 for gripping the guide rail 9 is attached to the upper part of the main body of the drop hammer device [H]. When the soundproof cover 71 and the drop hammer device [H] are to be slid significantly, the holder 77 is removed to avoid interference with the soundproof cover 71.

In the embodiments shown in FIGS. 14 and 16, it is also possible to use the long cap 2 used in the embodiment shown in FIG. 1 on the pile cap.

According to the present invention explained above, the following effects can be obtained.

(1) The extremely simple structure can reduce noise when the pile is struck.

(2) The construction worker can directly observe the movement of the weight through the opening when the pile is struck. This allows you to know the rising height of the weight, allowing safe and reliable construction.6 Also, any abnormalities such as shillings can be detected early.

(3) Warm air inside the soundproof wall rises and escapes to the outside through the opening, and conversely, cooling air automatically enters and descends into the soundproof wall. As a result, the heat balance of the power source of the drop hammer device is lowered by 1 degree, contributing to downsizing of the cooling device.

(4) In the event of an emergency, the opening can be used for maintenance, inspection, etc. Therefore, maintenance becomes easier.

(5) The presence of the opening can alleviate the instantaneous increase in wind pressure when the weight falls. As a result, unnecessary force due to wind pressure is not applied to the soundproof wall, extending its lifespan.If the soundproofing wall is designed taking this wind pressure drop into account, it can be made lighter. You can also do it.

Fig. 1 is a cross-sectional view showing one embodiment of the present invention, Fig. 2 is an enlarged cross-sectional view taken along the line ■-■ in Fig. 1, Fig. 3 is an enlarged cross-sectional view taken along FIG. 5 is an explanatory diagram of the noise level of the soundproof wall body according to the present invention, and FIGS. A side view showing another embodiment, FIG. 7 is a side view of FIG.
■ Cross-sectional view, Figure 9 is the ■-■ cross-sectional view of Figure 8, Figure 11 is the XI-XI cross-sectional view of Figure 1θ, and Figure 13 is the ■-■ cross-sectional view of Figure 12.
-XI sectional view, FIG. 14 is a sectional side view showing another embodiment of the present invention, FIG.
6 is a sectional side view showing another embodiment of the present invention, No. 17
The figure is a sectional view taken along line 1--2 in FIG. 16.

H@・Drop hammer device, 1.・Weight, 2@・
o y ri 4 17p, 3...cushion, 4...
Holding stake, 6.-Hydraulic cylinder, 7.-Piston rod, 8.-Holder, 9.-Guide rail, 1.
0...Leader, 11...Hanging rope, 12@-Column, 13...Horizontal beam, 14--Upper frame, 15...Column, 16...Horizontal frame, 17...Upper frame, 1
8. Sealing wall, 191. Pile cover, 20.
・Soundproof wall, 20J1・・Shielding plate, 20b・・Back space, 20C・・Perforated plate, 20d・・Sound absorbing material, 21・・
Patsukin, 22... Patsukin, 23 @ Ring,
24...opening, 25...shielding plate, 41...
・Opening, 42--1 sound duct, 43--opening, 44...sound absorption duct)-i 45"・opening,
46...Sound absorption duct, 63...Holder, 64...Holder, 65...Soundproofing power, 66...Opening part,
67... Support part, 68... Cushion, 71
・・Soundproof cutie, 72・・Opening, 73・・Cushion, 74・・Guide rail, 75・・Holding device, 76・・Holding device, 77・・・Holding device, 78・・e Hanging rope 1st Figure 2 Figure 3 Figure 5 Figure 6 Figure 81 Figure 12 Figure 14 Procedure Sleeve Plan C Method) (Spontaneous) September 8th, 1986 Application No. 208818 2, Name of issue Soundproof eccentricity of pile driver 3 Relationship with the case of the person making the amendment Patent applicant n, +'+i Uchikanda, Chiyoda-ku, Tokyo - Chingll Mayushol
Mr. O Name (as'g) Hitachi Kanki Co., Ltd. Representative Bunpei Nishimoto 4, Agent 8 Contents of amendment (1) "Patent application" changed to "Patent application (Proviso to Article 38 of the Percentage Permit Act) □, (2) Add the paragraph [Number of inventions stated in claim 1: 2] to the title of the invention ◎

Claims (1)

[Scope of Claims] [1] Forming a sealed soundproof wall body surrounding substantially the lower half of the drop hammer main body, or substantially the lower half of the drop hammer main body and the upper end of the pile to be driven; At the top of the wall, an opening whose size is determined by the following formulas (1) and (2) and distance attenuation to the ground (dB) is provided.
・e・(1) Here, α is the average sound absorption coefficient inside the soundproof wall (dB)
...(2) (2) Form a sealed soundproof wall that surrounds substantially the lower half of the drop hammer main body, or substantially the lower half of the drop hammer main body and the upper end of the pile to be driven, and the soundproof wall An opening whose size was determined based on the following formulas (1) and (2) and distance attenuation to the ground was provided at the top of the system, and a sound absorbing element was constructed in the opening (dB)...
・(1) Here, i is the average sound absorption coefficient inside the soundproof wall (dB)
-...(2)