JP3889420B2 - Pneumatic caisson and material lock silencer - Google Patents

Description

  TECHNICAL FIELD The present invention relates to a pneumatic caisson and a material lock silencer provided with a material shaft and a material lock as earth removing equipment.

  In the pneumatic caisson method, the work space is under the floor slab provided at the bottom of the caisson, and the work space is excavated under high pressure with compressed air to prevent inundation. The material shaft that has been installed raises and lowers the earth removal bucket for carrying out the earth and sand excavated in the work space under the floor slab, and the material lock provided on the upper part of the material shaft allows the work space to be kept airtight and discharged. It can pass through the soil bucket.

  In material lock, a lock chamber is formed by upper and lower open / close doors, and an air supply pipe and an exhaust pipe are connected to this lock chamber. When carrying a soil bucket, the lower door is closed to ensure airtightness. Open the upper door and insert the earthing bucket, then close the upper door and pressurize the lock chamber between the upper and lower doors, open the lower door and lower the earthing bucket. When unloading the soil bucket, if the soil bucket is located in the lock chamber between the upper and lower doors, close the lower door, then depressurize the lock chamber by exhausting, then open the upper door and lift the soil bucket Carry out.

  The upper door has an insertion hole through which the wire rope that suspends the soil removal bucket is passed. When the soil removal bucket is inserted, high-pressure air leaks from the gap between the wire rope and the insertion hole. Noise due to the atmosphere is generated. As the caisson sinks, the air leak noise increases as the atmospheric pressure in the work space increases, which causes a problem as construction noise.

  As a technique for preventing noise due to air leakage in such a wire rope insertion hole, there is a silencing technique as described in Patent Documents 1 to 5, for example.

  The invention of Patent Document 1 is a material lock wire guide silencer, and is provided with a double-walled reverse cup-shaped box door that is divided into two and can be opened and closed on the left and right on the material lock. The sound absorbing material is filled between the steel plates, the high-pressure air flow leaking from the gap between the wire rope and the wire guide is expanded in the space inside the box door, and the air that has been reduced to a certain level passes through the sound absorbing material such as glass wool. Diffused into the atmosphere.

  The invention of Patent Document 2 is a silencer device in an air lock device for a material passage of a pressure air submerged chamber, provided with a silencer chamber that closes the entrance side of the material passage in a crowned state, and a cylinder that forms the outer peripheral wall surface of the silencer chamber An opening / closing lid that can be opened on both sides is provided on the cylindrical body, and a soundproof member comprising a soundproof panel having a ring frame and a large number of small holes is attached to the inner wall surface of the cylindrical body, and the wire and the wire insertion hole of the upper door High-pressure air leaking from the gaps between them flows into the silencer chamber to reduce the pressure, and most of the noise caused by the leaked sound is absorbed by a soundproofing member attached to the wall of the silencer chamber.

  The invention of Patent Document 3 is a material lock wire guide silencer, which provides a small space by a partition wall or the like on the back surface of the upper door, and a large amount of air entering the small space through the gap between the wire insertion hole on the bottom wall of the small space and the wire. A buffer or labyrinth is provided in a small space so that the air is discharged into the outside atmosphere through a silencer through a diameter exhaust pipe, and further, pressurized air does not reach the upper door and its wire guide.

  The invention of Patent Document 4 is a silencing structure of an air lock device, and is provided with an openable / closable decompression chamber surrounding the wire from both sides at the lower part of the upper door, and the decompression chamber is opened to the atmosphere through a communication pipe and a silencer. The noise caused by leakage is eliminated.

The invention of Patent Document 5 is a material lock silencing method and a silencing device, in which an openable / closable airtight chamber surrounding the wire from both sides is provided at the upper part of the upper door, and after the air leakage is reduced in the airtight chamber, the silencer Through the atmosphere.
Japanese Patent No. 2895478 Japanese Patent No. 3380854 Japanese Patent Laid-Open No. 10-245851 JP 2002-105965 A JP 2002-173940 A

  The conventional pneumatic caisson has a structure in which a material lock is provided on the upper part of the material shaft. Therefore, when adding a shaft due to excavation and sinking, the material lock must be lifted with a crane or the like to add the shaft. However, the work of adding the shaft was cumbersome and time consuming.

  Further, in the soundproof door type silencer of Patent Documents 1 and 2, noise generated by the high pressure air flow leaking from the gap between the wire rope and the wire guide can be reduced. Sufficient noise reduction cannot be performed, for example, after the air has accumulated once in the lower silencing chamber, the air accumulated in the silencing chamber leaks from the wire guide at the ceiling of the silencing chamber and noise is generated from the ceiling of the silencing chamber.

  Moreover, since the silencer of the material lock of patent documents 3-5 provides a silencer structure in the upper door which opens and closes, a structure becomes complicated and cost starts.

  Furthermore, all of the silencers of Patent Documents 1 to 5 are for noise generated by a high-pressure air flow leaking from a gap between the wire rope and the wire guide of the material lock, and from other parts of the material lock. The generated noise cannot be reduced.

  The present invention has been made in order to solve such problems, and can easily add material shafts in a pneumatic caisson, and can be generated from gaps or other places in the wire guide of the material lock. It is an object of the present invention to provide a pneumatic caisson that can reliably reduce noise generated and that can reliably reduce noise generated from material lock with a relatively simple silencer.

  Furthermore, an object of the present invention is to provide a material lock silencer capable of reliably reducing noise generated from material lock with a relatively simple device in a pneumatic caisson.

According to a first aspect of the present invention, there is provided a material shaft for lifting and lowering a soil removal bucket for carrying out the earth and sand excavated in a work space under a floor slab of a caisson, and the work space so as to be able to pass through the soil removal bucket by upper and lower doors In a pneumatic caisson with a material lock that maintains the airtightness of
A material lock is installed on the floor slab, and by placing a partition above the material lock, a space for storing the material lock is formed on the floor slab, and the penetration located above the material lock formed on the partition is formed. The lower part of the material shaft is attached to the hole, and the material shaft is provided with a silencer that reduces noise by interfering with noise with a waveform having a phase opposite to that of the noise. Caisson.

In other words, in terms of the caisson structure, when a material lock is placed on the floor slab at the bottom of the caisson, a material shaft is provided directly above the material lock via the shaft bulkhead, and excavation is performed when the material shaft is added due to excavation subsidence. It facilitates the addition of material shafts accompanying subsidence. In terms of silencing, the noise generated from the material lock is reduced by disposing the material lock in the silencing space surrounded by the caisson housing and the shaft partition under the caisson.
Further, an active silencing system including a sensor microphone that detects noise and a silencing speaker that oscillates sound having a waveform opposite in phase to the noise is used to silence noise generated from the material lock by interference. This active silencing system is effective in reducing noise at a relatively low frequency. For noise having a relatively high frequency, the active silencing system may be used in combination with a passive silencing shaft (sound absorbing material) that is effective at high frequencies.

  A second aspect of the present invention is the pneumatic caisson according to the first aspect, wherein a sound absorbing material is provided inside the material shaft. That is, the material shaft is a passive sound deadening shaft, and the noise generated from the material lock is absorbed by the sound absorbing material to mute.

According to a third aspect of the present invention, in the pneumatic caisson according to any one of the first and second aspects, a silencing device comprising a two-part door body that opens and closes so that the earth discharging bucket can pass is provided on an upper portion of the material shaft. The door body has an insertion hole through which the suspension material of the soil removal bucket is inserted, and a through hole that penetrates the door body around the insertion hole, and has a sound absorbing material on the inner wall surface of the hole . The pneumatic caisson is provided with a number of exhaust holes for discharging the air to the outside. In other words, it is a muffler door type passive silencer (exhaust hole straight type) installed at the upper part of the material shaft, and the noise generated from the material lock is exhausted to the outside while absorbing the sound from the many exhaust holes with the sound absorbing material. Reduce. Moreover, the air leakage sound from the suspension material insertion hole in the center of the silencer is reduced by dispersing and discharging from a number of exhaust holes.

According to a fourth aspect of the present invention, in the pneumatic caisson according to the first or second aspect , a silencer comprising a two-divided door body that opens and closes so that the earth discharging bucket can pass is provided on the upper portion of the material shaft. The door body has an insertion hole through which the suspension material of the soil removal bucket is inserted, a sound deadening space formed inside, and a sound absorbing material inside and outside, and introduces air in the material shaft into the sound deadening space. A pneumatic caisson is provided with a plurality of exhaust pipes and a plurality of exhaust pipes having a sound absorbing material inside and outside and exhausting the air in the silencing space to the outside. In other words, it is a muffler door type passive silencer (labyrinth type) installed on the upper part of the material shaft. The noise generated from the material lock is sucked into the silencer space from the lower exhaust pipe and discharged to the outside from the upper exhaust pipe. At that time, the sound is absorbed by the sound absorbing material in the exhaust pipe and the sound deadening space to reduce noise. Also in this case, the sound leakage from the suspension material insertion hole at the center of the silencer is reduced by dispersing and discharging from a large number of exhaust pipes.

According to a fifth aspect of the present invention, there is provided a material shaft for raising and lowering a soil discharging bucket for carrying out the earth and sand excavated in the work space under the floor slab of the caisson, and an upper door of the material shaft. It is a material lock silencer in a pneumatic caisson equipped with a material lock that keeps the work space airtight so that it can pass through a soil bucket, and it detects the noise generated from the soundproof cylinder provided at the top of the material lock and the material lock And a muffler speaker that oscillates the sound having a waveform opposite in phase to the noise, and a sound having a waveform opposite in phase to the noise based on a detection signal from the sensor microphone. a controller to be output to the mute speaker, the mute speaker at the top or near the top of the soundproof tube Plurality placed at a predetermined interval in the direction, it is material locking muffler, characterized in that the sensor microphone is placed inside the top near the soundproof tube. It is preferable to install a monitor microphone for detecting the sound after mute on the outside of the speaker, and operate the controller so that the sound of the monitor microphone is minimized.

  That is, it is an active silencing system, which silences noise generated from material lock by interference. This active silencing system is effective in reducing noise of a relatively low frequency, and can be used in combination with passive silencing (sound absorbing material) or the like for noise having a relatively high frequency.

In a pneumatic caisson where such a silencer is installed, a material lock is installed on the floor slab, a silencing space is formed by a partition above the material lock, and a material shaft is erected directly above the material lock by this partition. There is a material lock lower type, or a normal type material lock upper type with a material lock provided on the upper part of the material shaft. Claim 5 of this invention is a case where it applies to the normal type material lock upper part type.

  In the lower part of the material lock, if necessary, the material shaft is made a passive silencer shaft by a sound absorbing material, and an active silencer system is installed at the lower part of the material shaft. In the active silencing system, the amplitude and phase of the speaker are adjusted by the signal detected by the sensor microphone, and the signal detected by the monitor microphone is minimized to reduce noise in the material shaft. The noise-removing space where the material lock is stored, the passive sound-reducing shaft, and the active sound-reducing system make it possible to leak sound from the wire rope insertion hole of the upper door of the material lock, air supply sound and exhaust sound when the soil bucket is locked in and out, etc. Noise generated from material lock can be reduced.

  In the normal type material lock upper type, a soundproofing cylinder is provided above the material lock, and an active silencing system is installed in this soundproofing cylinder. If necessary, the soundproof cylinder is made a passive sound deadening cylinder with a sound absorbing material. For example, in the active silencing system, a plurality of silencing speakers are installed at a predetermined interval in the circumferential direction above or near the top of the soundproof cylinder, a sensor microphone is installed inside the top of the soundproof cylinder, and a monitor microphone is installed. Installed on the outside near the top of the soundproof cylinder, the controller adjusts the amplitude and phase of the speaker based on the signal detected by the sensor microphone and minimizes the signal detected by the monitor microphone to reduce the diffracted sound at the upper end of the soundproof cylinder. . The soundproofing cylinder and the active silencing system can reduce the leakage sound from the wire rope insertion hole of the upper door of the material lock.

According to a sixth aspect of the present invention, the working space is configured such that the earthing bucket for carrying out the earth and sand excavated in the working space under the floor slab of the caisson moves up and down, and the upper and lower doors allow the earthing bucket to pass through the earthing bucket. A material lock silencer in a pneumatic caisson equipped with a material lock that maintains the airtightness of the door, and is composed of a two-divided door body that opens and closes so that the soil removal bucket can pass through the door body. There are insertion holes through which the suspension material is inserted, and through holes that penetrate the door body around the insertion holes, and there are a number of exhaust holes that have a sound absorbing material on the inner wall surface of the hole and exhaust the air in the material shaft to the outside. A material lock silencer is provided.

  That is, it is a muffler-door type passive silencer (exhaust hole straight type), and the noise generated from the material lock is exhausted to the outside while absorbing the sound from a large number of exhaust holes with the sound absorbing material, thereby reducing the noise. Moreover, the air leakage sound from the suspension material insertion hole in the center of the silencer is reduced by dispersing and discharging from a number of exhaust holes.

According to a seventh aspect of the present invention, the working space is configured such that the earthing bucket for carrying out the earth and sand excavated in the working space under the floor slab of the caisson moves up and down, and the upper and lower doors allow the earthing bucket to pass through the earthing bucket. It is a material lock silencer in a pneumatic caisson equipped with a material lock that maintains the airtightness of the door, and is composed of a two-part door body that opens and closes so that the soil discharge bucket can pass therethrough. An insertion hole through which the suspension material is inserted, a sound-absorbing space formed inside, a plurality of exhaust pipes having a sound-absorbing material inside and outside and introducing air in the material shaft into the sound-absorbing space, and a sound absorbing material inside and outside And a plurality of exhaust pipes for discharging the air in the silencing space to the outside.

  In other words, it is a muffler door type passive silencer (labyrinth type), and the noise generated from the material lock is sucked from the lower exhaust pipe into the silencer space and discharged from the upper exhaust pipe to the outside. Noise is absorbed by the sound absorbing material in the space to reduce noise. Also in this case, the sound leakage from the suspension material insertion hole at the center of the silencer is reduced by dispersing and discharging from a large number of exhaust pipes.

  This muffler door type passive silencer (exhaust hole straight type, labyrinth type) is also installed in a pneumatic caisson such as a material lock lower type or a normal type material lock upper type. In the material lock lower part type, if necessary, the material shaft is made a passive sound deadening shaft by a sound absorbing material, and a muffler door type passive sound deadening device is installed on the upper part of the material shaft. The noise-removing space in which the material lock is stored, the passive sound-reducing shaft, and the muffler door-type passive sound-reducing device make it possible to leak air from the wire rope insertion hole of the upper door of the material lock, and Noise generated from material lock such as exhaust noise can be reduced. In the normal type material lock upper type, a muffler door type passive silencer is installed above the material lock. With this passive silencer, it is possible to reduce leakage sound from the wire rope insertion hole of the upper door of the material lock.

  (1) In a pneumatic caisson equipped with a material shaft and a material lock, the material lock is placed on the floor slab at the bottom of the caisson, and the material shaft is provided directly above the material lock via the shaft bulkhead. Accordingly, when adding the material shaft, it is not necessary to lift the material lock with a crane or the like as in the prior art, and the adding work of the material shaft can be performed very easily, and the construction efficiency of caisson work can be improved.

  (2) The noise generated from the material lock can be reduced by arranging the material lock in the silencing space surrounded by the caisson housing and the shaft bulkhead below the caisson. Not only the sound of leakage from the suspension material insertion hole of the upper door when entering the soil bucket, but also the air supply sound and exhaust sound when the soil bucket is locked in and out can be reduced.

  (3) A passive silencing shaft or an active silencing system can be provided on the material shaft directly above the material lock, and the noise generated from the material lock can be reliably reduced with a relatively simple silencing device.

  (4) A muffler door type passive silencer is installed on the upper part of the material shaft, and the noise generated from the material lock is exhausted to the outside while absorbing the sound from many exhaust holes or exhaust pipes with the sound absorbing material. The noise generated from the material lock can be reliably reduced with a relatively simple silencer by reducing the leakage sound from the suspension material insertion hole in the center of the silencer by discharging it from the exhaust holes or exhaust pipes can do.

  (5) An active silencer system that interferes with noise with a waveform with a phase opposite to that of the noise, or a muffler door type passive silencer equipped with a number of exhaust holes and exhaust pipes. Since the sound is silenced by being installed above or above, it is possible to reliably reduce the noise generated from the lower and upper material locks with a relatively simple device.

  Hereinafter, the present invention will be described based on the illustrated embodiments. FIG. 1 is a vertical cross-sectional view showing an embodiment of a pneumatic caisson of a material lock lower type according to the present invention. FIG. 2 is a configuration diagram showing an example of an active silencing system used in the caisson of FIG. FIG. 3 is a vertical cross-sectional view showing the caisson method of FIG. 1 in the order of steps. FIG. 4 is a vertical cross-sectional view of the pneumatic caisson of the present invention, showing different embodiments of the caisson housing and the silencer of FIG. FIG. 5 is a perspective view and a vertical sectional view showing an example of a passive silencer used in the caisson of FIG. FIG. 6 is a vertical cross-sectional view showing the insertion of the soil bucket in the caisson of FIG. 4 in the order of steps.

  1 to 6 show a case where the silencer of the present invention is applied to a material lock lower type pneumatic caisson, and FIGS. 7 to 9 show a normal type material lock upper type of the silencer of the present invention. This is a case where it is applied to the pneumatic caisson.

  As shown in FIG. 1, the pneumatic caisson 1 is composed of a floor slab 2, a side wall 3, a partition wall 4, and the like, and a work space (pressure air space) 5 is formed by the floor slab 2 at the bottom. Normally, a material lock that maintains the airtightness of the work space is connected to the upper part of the material shaft on which the earth removal bucket moves up and down. In the present invention, a material lock 6 is installed on the floor slab (work slab) 2. The material shaft 7 is disposed immediately above the material lock 6.

  Further, by providing a horizontal partition wall 8 above the material lock 6, the material shaft 7 can be supported and a sound deadening space 9 in which the material lock 6 is accommodated is formed on the floor slab 2. The horizontal partition wall 8 is provided with a through hole 10 located above the material lock 6, and the lower part of the material shaft 7 is inserted and fixed in the through hole 10. In addition, the space for the water load for subsidence can be formed between the caisson partition 4 and the shaft 7 by the shaft horizontal partition 8.

  As in the prior art, the material lock 6 has a lock chamber formed by upper and lower doors (not shown), and the upper door has an insertion hole (not shown) through which the wire rope 12 for suspending the soil bucket 11 is inserted. Is formed. The lock chamber is provided with an exhaust pipe that discharges internal air to the outside and an air supply pipe that supplies air to the inside (not shown). A through hole 13 through which the earth discharging bucket 11 can pass is formed in the floor slab 2, and a material lock 6 is installed on the through hole 13.

  When the material lock 6 is installed on the floor slab 2 and the material shaft 7 is disposed immediately above the material lock 6 to add the shaft in accordance with the excavation settlement, the unit shaft is added to the upper portion of the shaft 7. Therefore, the shaft extension work can be performed very easily. In addition, by arranging the material lock 6 in the silence space 9 surrounded by the bulkhead 4 and the horizontal bulkhead 8 below the caisson, noise generated from other places such as the wire rope insertion hole of the upper door, the exhaust pipe and the air supply pipe However, in the present invention, the passive noise reduction shaft and the active noise reduction system are further combined to achieve a significant noise reduction.

  The passive muffler shaft can be configured by providing the sound absorbing material 20 on the inner surface of the material shaft 7 and can reduce high-frequency noise. The active silencing system 21 is installed outside the lower portion of the material shaft 7. This active silencing system 21 reduces noise by causing noise having a phase opposite to that of noise to interfere with noise, and can reduce noise at a low frequency (for example, 1000 Hz or less). By combining both, it is possible to reduce high-frequency noise and reduce low-frequency noise, which has recently become a complaint.

  For example, as shown in FIG. 2, the active silencing system 21 can be composed of a sensor microphone 22, a silencing speaker 23, a monitor microphone 24, and a controller 25. The noise N in the material shaft 7 is detected by the sensor microphone 22 arranged on the upstream side of the muffler speaker 23, and the detection signal (amplitude / phase) from the sensor microphone 22 is input to the controller 25. A sound having a waveform having a phase opposite to that of the noise is generated with a sound pressure having a magnitude corresponding to the sound pressure, and is output to the mute speaker 23. The sound of the waveform having the opposite phase is oscillated and interfered with the noise N from the muffler speaker 23 to reduce the noise. The sound after mute is detected by the monitor microphone 24 arranged on the downstream side of the mute speaker 23 and fed back to the controller 25. The controller 25 controls the mute speaker 23 so that the sound of the monitor microphone 24 is minimized.

  In a pneumatic caisson that reduces noise by installing a material lock on the work room slab as described above, caisson work is performed in the following procedure (see FIG. 3).

  (i) After placing the caisson floor slab 2, that is, the working room slab, excavate with no-pressure air. After reaching the groundwater level, dispose the material lock 6 and start the excavation under pressure. At this stage, since the shaft horizontal partition wall 8 cannot be provided because of the height of the material lock 6 and the height of the caisson partition wall 4, the noise reduction in the caisson work depends only on the measure of the sound source.

  (ii) Subsidence excavation and construction of side walls, etc. have progressed, and a space for providing the shaft horizontal partition wall 8 above the material lock 6 is created.

  (iii) The shaft horizontal partition wall 8 and the material shaft 7 are installed above the material lock 6. A sound absorbing material 20 is provided on the inner surface of the material shaft 7, and an active silencing system 21 is installed at the base of the passive silencing shaft 7 to perform subsidence excavation.

 (Iv) The caisson side wall 3 and the caisson bulkhead 4 are added and subsidence excavation is performed.

 (V) Passive silencer shaft 7 is added, caisson side wall 3 and caisson bulkhead 4 are added, and subsidence excavation is performed.

  Due to the passive silencing shaft 7 and the active silencing system 21, the material lock 6 generates air leakage sound from the wire rope insertion hole of the upper door of the material lock 6, air supply sound and exhaust sound when the soil bucket is locked in and out. Noise is greatly reduced.

  Next, the pneumatic caisson 1 shown in FIG. 4 is different from that shown in FIG. 1 in the structure of the caisson housing, but is composed of a floor slab 2, a side wall 3, a partition wall 4 and the like as in FIG. A space (pressure air space) 5 is formed, a material lock 6 is installed on the floor slab (work chamber slab) 2, and a material shaft 7 is arranged immediately above the material lock 6. Further, by providing the horizontal partition 8 above the material lock 6, a silencing space 9 in which the material lock 6 is stored is formed, and the horizontal partition 8 is provided with a through hole 10 positioned above the material lock 6. The lower portion of the material shaft 7 is inserted and fixed in the through hole 10.

  A muffler door-type passive muffler 30 is used, which is installed on the upper part of the material shaft 7 and is composed of a two-part door body 31 that opens and closes so as to allow passage of a soil removal bucket, unlike FIG.

  The door body 31 is configured by dividing a cylindrical member serving as an opening / closing door and a muffler into two parts on a vertical plane and connecting one end portions of the semi-cylindrical door bodies 31a and 31a with a hinge 32. A bell mouth 33 is connected to the upper end of the material shaft 7. A support member 34 that protrudes horizontally is attached to the outer surface of the bell mouth 33, and a pin of the hinge 33 is fixed to the support member 34. The two door bodies 31a, 31a are positioned on the bell mouth 33 in a closed state, and can be retracted from the bell mouth 33 to the side in an open state. An engagement hole 35 is formed at the bottom of the two door bodies 31a, 31a so that the bell mouth 33 can be completely covered in the closed state. The opening / closing method is not limited to the illustrated example, and a horizontal sliding method may be used.

  Such door bodies 31a and 31a are provided with an insertion hole 36 through which the wire rope 12 for suspending the earthing bucket is inserted, and a number of exhaust holes 37 for discharging the air in the material shaft 7 to the outside. The insertion hole 36 is provided in the center in a plan view of the door body 31. A semi-cylindrical hole is formed on the joint surface of the two door bodies 31 a and 31 a with a wire block or the like, and when the door body 31 is closed, the insertion of the cylindrical shape is performed. A hole 36 is formed. The exhaust hole 37 is a straight type formed vertically, and a sound absorbing material 38 is provided on the inner surface thereof.

  In the case of FIG. 4 as well, similarly to FIG. 1, the material lock 6 is disposed in the noise-reducing space 9 surrounded by the partition wall 4 and the horizontal partition wall 8 at the lower part of the caisson, so that the wire rope insertion hole of the upper door, the exhaust pipe, The noise generated from other parts such as the air pipe can be reduced, and further, the muffler door type passive silencer 30 having the above-described configuration is used to leak the air leak through the wire rope insertion hole of the upper door of the material lock 6. The noise generated from the material lock 6 such as the air supply sound and the exhaust sound when the soil bucket is locked in and out is discharged to the outside while being absorbed through the many exhaust holes 37, and the noise generated from the material lock 6 is reduced. Can do. Moreover, by dispersing and discharging from a large number of exhaust holes 37, the sound of leakage from the wire rope insertion hole 36 at the center of the silencer is greatly reduced.

  FIG. 5 shows a labyrinth type with enhanced noise reduction effect, in which a silencer space 40, a plurality of lower exhaust pipes 41, and a plurality of upper exhaust pipes 42 are provided in a semi-cylindrical door body 31a. The door body 31a is a housing composed of a semicircular lower plate 43 and an upper plate 44, an arc-shaped side plate 45, and a linear side plate 46, and a sound deadening space 40 is formed therein. Further, a sound absorbing material 47 is attached inside the housing.

  The lower exhaust pipe 41 is attached to the lower plate 43 so that the lower end thereof penetrates, so that the air in the material shaft 7 can be introduced into the sound deadening space 40. The upper exhaust pipe 42 is attached to the upper plate 44 so that the upper end penetrates, and the air in the muffler space 40 can be discharged to the outside. A sound absorbing material 48 is attached to both the inside and outside of the exhaust pipes 41 and 42. Further, the lower exhaust pipe 41 and the upper exhaust pipe 42 are arranged alternately so that a labyrinth is formed.

  Further, the insertion hole 36 through which the wire rope 12 is inserted can be configured by attaching a wire guide 50 having a semi-cylindrical shape divided into two and having a sound absorbing material 49 attached to the inner surface to the center of the linear side plate 46, When the pair of door bodies 31a and 31a are closed, a circular insertion hole 35 is formed by the pair of integrated wire guides 50 and 50.

  In the case of such a labyrinth type muffler door type passive silencer 30, the air in the material shaft 7 is sucked into the sound deadening space 40 through the lower exhaust pipe 41, and passes through the upper exhaust pipe 42 to the outside. Since it is discharged and discharged while being silenced by the respective sound absorbing materials of the exhaust pipe 41, the silence space 40, and the exhaust pipe 42, noise can be greatly reduced. Also in this case, the air leakage sound from the wire rope insertion hole 36 at the center of the silencer is greatly reduced by dispersing and discharging from the multiple exhaust pipes 41 and 42.

  In the above-structured straight type or labyrinth type muffler door type passive silencer, the dump bucket is inserted in the following procedure (see FIG. 6).

  (I) With the door body 31 divided into two parts, the door body 31 a and 31 a are opened, and the earthing bucket 11 is suspended on the material shaft 7 in a state where the door body 31 is retracted from above the material shaft 7.

  (Ii) The earth removal bucket 11 is inserted into the material shaft 7.

  (Iii) The split door bodies 31a and 31a are closed. The wire rope 12 of the soil removal bucket 11 is disposed through the central insertion hole 35.

  (Iv) Open the upper door of the material lock 6 and suspend the earth removal bucket 11 in the material lock 6.

  (V) When the earth discharging bucket 11 is completely inserted into the material lock 6, the upper door is closed and air is supplied into the material lock 6 through the air supply pipe. The lower door is opened, the soil removal bucket 11 is lowered into the work space (pressure air space) 5 and the earth and sand are loaded. During the air supply period, an air supply sound is generated, and thereafter, during the period when the earth discharging bucket 11 is in the box, an air leak sound is generated from the wire rope insertion hole of the upper door. When the excavation soil loading into the earth discharging bucket 11 is completed and the earth discharging bucket 11 enters the material lock 6, the lower door is closed and the air in the lock chamber is discharged through the exhaust pipe. These air supply sound, air leakage sound, and exhaust sound are greatly reduced by the silencer space 9 and the muffler door type passive silencer 30.

  (Vi) When the pressure in the lock chamber is reduced to atmospheric pressure, the upper door is opened, the soil removal bucket 11 is hung out of the material lock 6, the split door bodies 31a and 31a are opened, and the soil discharge bucket 11 is removed from the material shaft 7. Hang out outside, and after traversing, drain to earth and sand hopper.

  Next, FIG. 7 shows an embodiment in which an active silencing system is applied to a normal type material caliper type pneumatic caisson. 8 and 9 show an embodiment in which a muffler door type passive silencer is applied to a normal type material lock upper type pneumatic caisson.

  In FIG. 7, the material lock upper type pneumatic caisson 1 has a material shaft 7 standing on a floor slab 2, and a material lock 6 installed on the material shaft 7. The material lock 6 is provided with, for example, a pair of upper doors 14 and 14 that swing downward and open and a lower door 15 that swings upward and downward, and the center closing surface of the upper door 14 is divided by a split guide block or the like. An insertion hole 16 for the wire rope 12 is provided. An air supply pipe 17 and an exhaust pipe 18 are connected to the lock chamber between the upper and lower doors.

  In such a normal type, a soundproof cylinder 60 is provided on the material lock 6, and the active sound deadening system 21 is installed in the soundproof cylinder 60. The active silencer system 21 includes a sensor microphone 22, a silencer speaker 23, a monitor microphone 24, and a controller 25, as in the case of the caisson of FIG. 1, but in the case of the caisson of FIG. Since air leakage sound from the rope insertion hole 16 is a target, for example, a plurality of speakers 23 are installed at a predetermined interval near the upper end or near the upper end of the soundproof cylinder 60, and the sensor microphone 22 is placed near the upper end of the soundproof cylinder 60. Installed on the inside, the monitor microphone 24 is installed on the outside near the upper end of the soundproof cylinder 60, and the sound of the opposite phase is created with the sound pressure of the magnitude corresponding to the magnitude of the noise detected by the sensor microphone 22. And the sound from the speaker 23 is controlled so that the sound detected by the monitor microphone 5 is minimized. To reduce the sound.

  If the sound-absorbing material 20 is provided on the inner surface of the sound-proofing cylinder 60 to make a passive sound-deadening cylinder, a comparatively high-frequency noise is reduced and a comparison is made by an active noise reduction system 21 that makes noise opposite in phase to noise interfere with the noise. The noise of a low frequency can be reduced, and the leakage sound from the wire rope insertion hole 16 can be surely reduced.

  The muffler door type passive silencer 30 (exhaust hole straight type and labyrinth type) shown in FIGS. 8 and 9 can be installed directly on the upper part of the material lock 6. The structure and operation are the same as in FIGS. 4 and 5, and the leak sound from the wire rope insertion hole 16 of the upper door is discharged to the outside while absorbing the sound from the numerous exhaust holes 37 or the exhaust pipes 41, 42 with the sound absorbing material. By doing so, the leak sound from the wire rope insertion hole 16 can be reduced. Also in this case, the sound leakage from the wire rope insertion hole 36 at the center of the silencer is greatly reduced by dispersing and discharging from the numerous exhaust holes 37 and the exhaust pipes 41 and 42.

  Although not shown, the passive silencer shaft 7 and the active silencer system 21 and the muffler door type passive silencer 30 can be used in combination.

It is a vertical sectional view showing one embodiment of the pneumatic caisson of the material lock lower part type of the present invention. It is a block diagram which shows an example of the active silence system used with the caisson of FIG. FIG. 2 is a vertical cross-sectional view showing the caisson method of FIG. 1 in the order of steps. It is a pneumatic caisson of the present invention, and is a vertical sectional view showing different embodiments of the caisson housing and the silencer of FIG. FIG. 5A is a perspective view and FIG. 5B is a vertical sectional view showing an example of a passive silencer used in the caisson of FIG. FIG. 5 is a vertical cross-sectional view showing, for example, the introduction of a soil discharging bucket in the caisson of FIG. 1A is a perspective view, FIG. 2B is a vertical cross-sectional view, and FIG. 3C is an illustration of an active silencer system when the silencer of the present invention is applied to a normal type material lock upper type pneumatic caisson. It is a block diagram. (A) is a vertical cross-sectional view and (b) is a plan view showing an embodiment in which the passive silencer of the present invention is applied to a normal type material lock upper type pneumatic caisson. (A) which shows the other example of the passive silencer of this invention used for FIG. 8 is a perspective view, (b) is a vertical sectional view.

Explanation of symbols

1 …… Pneumatic caisson 2 …… Caisson floor slab 3 …… Caisson side wall 4 …… Caisson partition wall 5 …… Work space (pressure air space)
6 ... Material lock 7 ... Material shaft 8 ... Horizontal bulkhead 9 ... Silent space 10 ... Through hole 11 ... Soil bucket 12 ... Wire rope 13 ... Through hole 14 ... Upper door 15 ... Lower Door 16 ... Insertion hole 17 ... Air supply pipe 18 ... Exhaust pipe 20 ... Sound absorbing material 21 of passive silencer shaft ... Active silencer system 22 ... Sensor microphone 23 ... Silencer speaker 24 ... Monitor microphone 25 ... Controller 30... Muffler door type passive silencer 31.. Door body 31 a... Semi-cylindrical door body 32... Hinge 33 .. bell mouth 34 .. support member 35 .. engagement hole 36. …… Exhaust hole 38 …… Sound absorbing material 40 …… Silent space 41 …… Exhaust pipe 42 …… Exhaust pipe 43 …… Lower plate 44 …… Top plate 45 …… Arc-shaped side plate 46 …… Straight side plate 47 …… ... sound absorbing material 48 ... Sound material 49 ...... sound absorbing material 50 ...... wire guide 60 ...... soundproofing tube

Claims (7)

A material shaft that lifts and lowers the earth removal bucket that carries the earth and sand excavated in the work space under the caisson's floor slab, and a material lock that keeps the work space airtight so that the upper and lower doors can pass through the earth removal bucket. In the pneumatic caisson provided,
A material lock is installed on the floor slab, and by placing a partition above the material lock, a space for storing the material lock is formed on the floor slab, and the penetration located above the material lock formed on the partition is formed. The lower part of the material shaft is attached to the hole, and the material shaft is provided with a silencer that reduces noise by interfering with noise with a waveform having a phase opposite to that of the noise. caisson.   2. The pneumatic caisson according to claim 1, wherein a sound absorbing material is provided inside the material shaft. In the pneumatic caisson according to any one of claims 1 and 2, a silencing device comprising a two-part door body that opens and closes so that a soil discharging bucket can pass is provided on an upper portion of the material shaft, A through hole through which the suspension material of the soil removal bucket is inserted, and a through hole that penetrates the door body around the insertion hole and has a sound absorbing material on the inner wall surface of the hole, and discharges air in the material shaft to the outside Pneumatic caisson, characterized in that it has an exhaust hole. In the pneumatic caisson according to any one of claims 1 and 2, a silencing device comprising a two-part door body that opens and closes so that a soil discharging bucket can pass is provided on an upper portion of the material shaft, An insertion hole through which the suspension material of the earthing bucket is inserted, a sound deadening space formed inside, a plurality of exhaust pipes having a sound absorbing material inside and outside and introducing the air in the material shaft into the sound deadening space, and the inside A pneumatic caisson having a sound absorbing material on the outside and provided with a plurality of exhaust pipes for discharging the air in the silencing space to the outside. The material shaft that lifts and lowers the earth removal bucket that carries the earth and sand excavated in the work space under the caisson floor slab, and the work that is provided above the material shaft and that can pass through the earth removal bucket by the upper and lower doors A material lock silencer in a pneumatic caisson equipped with a material lock that keeps the airtight of the space,
From a soundproof cylinder provided in the upper part of the material lock, a sensor microphone for detecting noise generated from the material lock , a muffler speaker for oscillating a sound having a waveform opposite in phase to the noise, and the sensor microphone A controller that creates a sound having a waveform opposite in phase to the noise based on the detected signal and outputs the sound to the muffler speaker , wherein the muffler speaker is arranged at a predetermined interval in the circumferential direction above or near the upper part of the soundproof cylinder. A material lock silencer characterized in that a plurality of sensor microphones are installed inside and near the upper part of the soundproof cylinder . A material shaft that lifts and lowers the earth removal bucket that carries the earth and sand excavated in the work space under the caisson's floor slab, and a material lock that keeps the work space airtight so that the upper and lower doors can pass through the earth removal bucket. A material lock silencer in a pneumatic caisson equipped with,
The door body is composed of a two-part door body that opens and closes to allow passage of the soil removal bucket. The door body has an insertion hole through which the suspension material of the soil disposal bucket is inserted, and a through hole that penetrates the door body around the insertion hole. A material lock silencer characterized in that a sound absorbing material is provided on the inner wall surface of the hole, and a plurality of exhaust holes for discharging the air in the material shaft to the outside are provided. A material shaft that lifts and lowers the earth removal bucket that carries the earth and sand excavated in the work space under the caisson's floor slab, and a material lock that keeps the work space airtight so that the upper and lower doors can pass through the earth removal bucket. A material lock silencer in a pneumatic caisson equipped with,
The door body is composed of a two-part door body that opens and closes so that the soil removal bucket can pass therethrough. The door body has an insertion hole through which the suspension material of the soil disposal bucket is inserted, a sound deadening space formed inside, and a sound absorption inside and outside. And a plurality of exhaust pipes for introducing the air in the material shaft into the silencing space and a plurality of exhaust pipes having a sound absorbing material on the inside and outside for discharging the air in the silencing space to the outside. The material lock silencer characterized by being.

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