JPH04197288A - Reverberation time adjusting device - Google Patents

Abstract

PURPOSE:To improve the adjusting capacity of a reverberation time by providing a cover body which is attached to the lowest part of a sound absorbing material through an elastic body such as a spring, etc., and also, abuts on the ceiling surface at the time when the sound absorbing material is suspended upward and closes an opening part. CONSTITUTION:When a sound absorbing material 4 is suspended by a wire rope 3, a cover body 7 pressed against a supporting device 6 abuts on the lower end part of a guide tube 5, and when it is further suspended, suspending force of the wire rope 3 becomes larger than force by which a sprang 10 presses the cover body 7 to the upper part. Accordingly, in a state that the cover body 7 is pressed against the guide tube 5, the sound absorbing material 4 and a supporting layer 6 are drawn up to the upper part. As a result, an opening part 2 of the ceiling surface 1 is closed up completely by the guide tube 5 and the cover body 7. The guide tube 5 is provided in order to execute surely an operation of the cover body 7 because the ceiling surface of a theater, etc., is constructed with an inclination by considering a sound effect, etc., and also, the spring 10 becomes free from a work for adjusting a suspending stroke by the wire rope 3 so that a clearance of the lower end of the guide tube 5 and the cover body 7 becomes '0'.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Field of Industrial Application) The present invention relates to a reverberation time adjustment device for theaters, studios, music halls, etc.

(Prior Art) It is well known that when a performance is performed in a music hall or the like, there are differences in the suitable reverberation time depending on the type of musical instrument. For example, in the case of a piano, the reverberation time is relatively short;
In the case of a pipe organ, it is said that the longer the organ, the easier it is to play.

Generally, the reverberation time in a theater or the like is determined by the volume of the room, the total area of the interior walls of the room, and the sound absorption coefficient of the interior walls. For this reason, in recent years, there have been an increasing number of cases in which devices are installed on the inner walls of theaters and the like to adjust the reverberation time by changing the exposed area of the sound absorbing material to change the average sound absorption coefficient of the wall surface.

Another possible means of adjusting the reverberation time is to create an opening in the ceiling of the theater, insert and remove a cylindrical sound absorbing material through this opening, and adjust the reverberation time depending on the amount of protrusion of the cylindrical sound absorbing material. It is being

FIG. 8 shows an example of the configuration of such a reverberation time adjustment device. As shown in FIG. 8, cylindrical sound absorbing materials 4 are suspended by wire lobes 3 so as to be movable in the vertical direction from a plurality of openings 2 provided at appropriate intervals in the ceiling surface 1. .

In the figure, (A) shows a state in which the sound absorbing material 4 is suspended to the lowest position, and (C) shows a state in which it is pulled up above the ceiling surface 1 and does not protrude from the ceiling surface 1. B) shows an intermediate state. Here, in (A), the protrusion amount H of the lower side of the ceiling surface 1 is large, and the reverberation time in the room is determined by the surface area of the sound absorbing material 4 within this range of H. That is, depending on the capacity of the room, the total area of the inner wall, the sound absorption coefficient of the inner wall, the surface area of the protruding amount H of the sound absorbing material 4 and its sound absorption coefficient, how many sound absorbing materials 4 should be provided, and how much the protruding amount H should be determined. is calculated. If the protrusion amount H is large, the reverberation time will be shortened, and if H is 0, the reverberation time will be lengthened. This protrusion amount H is adjusted by winding or unwinding using a separately provided wire drum device (not shown) or the like.

(Problem to be Solved by the Invention) By the way, there is naturally a gap (D-d) between the inner diameter of the opening 2 provided in the ceiling surface 1 and the outer diameter d of the sound absorbing material 4.

Therefore, the sound in the room escapes into the space behind the attic through this gap, which cannot be ignored in order to accurately calculate the reverberation time. Sound that enters this gap is almost completely unable to return, so in calculations it can be considered a sound absorption surface with a sound absorption rate of 100%.

Therefore, in order to evaluate the change in reverberation time between state CA) and state (C) in FIG.
Another issue is the size of the gap (D-d). Even if the second gap (D-d) or the width (X) or the protrusion amount H changes in extreme cases, the reverberation time will hardly change.For this reason, this gap should be made as large as possible. Is there a need to make it smaller?

However, as a practical matter, the sound absorbing material 4 is suspended from a beam (not shown) installed directly under the roof via a wire lobe 3 via a pulley or the like (not shown). Since there is a gap between the ceiling surface 1 and the ceiling surface 1 that is longer than the length of the sound absorbing material 4, there must be a certain amount of gap in order to reliably move the sound absorbing material 4 through the opening 2.

The present invention was made in view of the above circumstances, and its purpose is to improve the ability to adjust reverberation time with a simple configuration by ensuring the operation of sound absorbing material through the opening provided in the ceiling surface. The aim is to provide a reverberation time adjustment device that can

[Structure of the Invention (Means for Solving the Problems)] In order to achieve the above object, the present invention suspends a sound absorbing material from an opening provided in a ceiling surface of a theater, etc. In the device for adjusting the reverberation time by adjusting the sound absorbing material, the device is attached to the lowest part of the sound absorbing material via an elastic body such as a spring, and when the sound absorbing material is lifted upward, it comes into contact with the ceiling surface and closes the opening. The structure is such that a lid is provided to close the section.

(Function) In the reverberation time adjustment device with such a configuration, when the sound absorbing material is lifted from the ceiling through the opening, the opening is closed by the lid attached to the lower part of the sound absorbing material via an elastic body. Since the sound is blocked, the sound at this time will not escape to the attic through the gap between the sound absorbing material and the opening, and the ability to adjust the reverberation time can be improved. Further, even if a gap is formed between the opening and the sound absorbing material, it will not affect the adjustment of the reverberation time, so the hoisting and hanging operations of the sound absorbing material will not be hindered.

(Example) Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows the configuration of a first embodiment of the reverberation time adjustment device according to the present invention, and the same parts as in FIG. 8 are indicated by the same symbols. In FIG. 1, a guide tube 5 is inserted into a plurality of openings 2 provided at appropriate intervals in a ceiling surface 1 with its lower opening end being horizontal and protruding downward from the ceiling surface 1. Through each of these guide tubes 5, a cylindrical sound absorbing material 4 is suspended by a wire lobe 3 so as to be movable in the vertical direction. A disk-shaped lid 7 having a larger diameter than the opening 2 is provided on the lower end surface of the sound absorbing material 4 via a support device 6 . This support device 6 has a lid 7 attached to the lower end of a vertically provided rod 8 through a through hole in the bottom of the case 6a, and a lid 7 attached to the bottom of the case 6a and a plate 9 attached to the upper end of the rod 8. The lid body 7 is elastically supported so as to be movable up and down by a spring 10 inserted therein.

In the reverberation time adjustment device configured as described above, when the sound absorbing material 4 is suspended, the spring 10 pushes the plate 9 upward with a force greater than the weight of the lid 7, as shown in (A). The lid body 7 is in a state of being crimped to the bottom of the case of the support device 6.

The amount of protrusion of the sound absorbing material 4 from the ceiling surface 2 in this state is the amount H of protrusion from the lower end of the guide tube 5, as shown. On the other hand, when the sound absorbing material 4 is lifted upward, the lid body 7 is in contact with the lower end of the guide tube 5, as shown in (C). That is, when the sound absorbing material 4 is lifted by the wire rope 3, the lid 7 that has been crimped to the support device 6 hits the lower end of the guide tube 5, and when it is lifted further, the spring 10 presses the lid 7 upward. Since the lifting force of the wire rope 3 is larger than the lifting force, the sound absorbing material 4 and the support device 6 are pulled upward while the lid body 7 remains pressed against the guide tube 5.

As a result, the opening 2 in the ceiling surface 1 is completely closed by the guide tube 5 and the lid 7. The guide pipe 5 is provided to ensure the operation of the lid body 7, since the ceiling surface of theaters etc. is generally constructed with an inclination in consideration of acoustic effects, etc., and the guide pipe 5 is provided with a spring. Reference numeral 10 is provided to omit the work of adjusting the lifting stroke of the wire rope 3 so that the gap between the lower end of the guide tube 5 and the lid 7 becomes zero.

FIG. 2 shows a schematic configuration of a second embodiment of the present invention, and the same parts as in FIG. 1 are denoted by the same symbols. In the embodiment shown in FIG. 2, guide tubes 5 are made to protrude downward from the ceiling surface 1 through a plurality of openings 2 provided at appropriate intervals in the ceiling surface 1 with their lower ends being horizontal. is inserted,
A sound absorbing material 4 is provided through this guide pipe 5, and
It is suspended by a wire rope 3 via a hanging frame 11 so as to be movable in the vertical direction. A lid 7 is attached to the lower end of the sound absorbing material 4 in a structure shown in detail in FIGS. 3 and 4.

FIG. 3 is a cross-sectional view for explaining the state in which the sound absorbing material 4 is suspended above the ceiling surface 1, and FIG.
It is an arrow sectional view along the A line. That is, as shown in FIGS. 3 and 4, a bottom plate 12 is fitted to the lower end of the sound absorbing material 4. In addition, a pair of rods 13a and 13b are provided in the hollow part of the sound absorbing material 4 symmetrically about the central axis.
passes through the spacer tube 14 and is further disposed so as to be vertically movable through a hole provided in the bottom plate 12. At the lower ends of the pair of rods 13a, 13b, a lid body 7 made of a material with low sound absorption coefficient, such as metal, and having a rubber plate 15 pasted on the back side, is attached and fixed, and at the upper end, a cover body 7 is fixed. 16 is fixedly mounted. On the other hand, a rod 17 is disposed on the central axis of the hollow part of the sound absorbing material 4, and its lower end is fixed to the bottom plate 12. The upper end of this rod 17 slidably passes through a hole provided in the plate 16.
Its upper end is connected to a hanging frame 11.

Further, a spring 18 is provided on the outer periphery of the rod 17. In this case, the rod 17 is in contact with spacers (not shown) at appropriate intervals between the rod 17 and the sound absorbing material 4, and together with the holding function of the bottom plate 12, the rod 17 prevents the sound absorbing material 4 from falling due to its weight.

Further, spring pins 19 are driven into the bottom plate 14 of the rods 13a and 13b.

Next, the operation of the reverberation time adjustment device configured as described above will be described.

When the sound absorbing material 4 is suspended downward from the ceiling surface 1, the lid 7 is pushed up by the compressed spring 18, so that the rod 13a.

The spring pin 19 driven into 13b is pushed up to a position where it hits the bottom plate 12. In this case, a rubber plate 15 is attached to the lid 7, and since the rubber plate 15 acts as a damping material, the lid 7 is affected by loud noises in the room.
There is no such thing as resonance.

When the sound absorbing material 4 is lifted upward in this state, the lid 7 hits the lower end of the guide tube 5, and the rods 13a, 13b
The bottom plate 12 slides using the rod 17 as a guide, and the sound absorbing material 4 is lifted up while sliding the rod 17 or the hole in the plate 16 to compress the spring 18. Then, when the sound absorbing material 4 reaches a predetermined position and a limit switch (not shown) is activated, winding of the wire lobe 3 is stopped and the upward movement of the sound absorbing material 4 is stopped. In this case, spring 1
Adjustments have been made so that the compressor 8 will stop before reaching the allowable compressed length. Also, at this time, the rubber plate 15 is sandwiched between the guide tube 5 and the lid 7 and is elastically deformed.
It has the function of closing even the slightest gap between the

As the sound absorbing material 4 is lifted in this way, it is adjusted so that it stops at a predetermined position, or if it does not stop, the plate 16 hits the spacer tube 14.
The wire lobe 3 is stopped by applying a large load to a hoisting device (not shown). Further, the spacer 14 has a dimension longer than the allowable compression length of the spring 18, and is provided to protect the spring 18.

In the second embodiment as shown in 2, since it is possible to eliminate the gap between the sound absorbing material 4 and the ceiling surface 1 when it is lifted, the reverberation time can be lengthened. Further, the rubber plate 15 is connected to the lid body 7.
It has the function of suppressing the vibration of the guide tube 5, and can completely close the gap when it comes into contact with the guide tube 5. Further, since the device supporting the lid 7 is provided in the hollow portion of the sound absorbing material 4, a reduction in the surface area of the sound absorbing material 4 can be avoided.

In the first and second embodiments described above, the cover body 7 is disk-shaped, and the sound-absorbing material 4 is also cylindrical, but the present invention is not limited to this. Various shapes such as square or rectangular cross sections are possible.

In addition, in the above embodiment, considering the use in a theater where the ceiling surface is inclined, a case was described in which a guide pipe was provided in the opening 2 of the ceiling surface 1, but the guide pipe 5 was not provided and the lid body 7 was The opening 2 in the ceiling surface 1 may be closed.

FIG. 5 shows a third embodiment of the present invention in which the guide tube is not provided on the ceiling surface, and only the differences from FIG. 1 will be described below. As shown in FIG. 5, the rod 20 suspended from the support device 7 connects the lid body 7 and
The lid body 7 is configured to be rotatable with respect to the rod 20 in two directions perpendicular to the axial direction of the rod 20.

With such a configuration, the lid body 7 can close the opening 2 without any gap even if the ceiling surface 1 is inclined. Furthermore, if the sound absorbing material 4 is fixed so as not to rotate in its axial direction, the direction in which the lid 7 moves when it hits the ceiling surface 1 is constant; 7 does not need to have a rotation function in any direction other than the direction in which it is necessary to operate. Furthermore, if the ceiling surface 1 is horizontal, all of these functions are unnecessary, and the lid body 7 is fixed to the rod 8 suspended from the support device 7 as explained in FIG. It is also possible to close the opening 2 in the ceiling surface 1 even with a similar structure.

On the other hand, in each of the embodiments described above, a compression coil spring was used to lift the lid 7, but a tension coil spring or a constant force spring 22 as in the fourth embodiment shown in FIG. 6 may also be used. Sponge rubber or the like may be used instead. Furthermore, a fixed pulley may be provided above the lid 7, a wire lobe with one end fixed is hung on the lid 7, and a counterweight is suspended from the other end, so that the lid 7 is always lifted upward.

In each of the embodiments described above, a case has been described in which an elastic body is inserted and supported between the lower part of the sound absorbing material 4 and the lid 7, but this elastic body is not limited to the lower part of the sound absorbing material. It is also possible to provide it at other locations.

FIG. 7 shows the configuration of a device for raising and lowering a plurality of sound absorbing materials 4 via a hanging frame 11 as a fifth embodiment of the present invention. As shown in FIG. 7, the lid 7 is fixed to the sound absorbing material 4, and the sound absorbing material 4 is supported on the hanging frame 11 via a rod 23 and a compression coil spring 24.

In such a configuration, when the hanging frame 11 is lifted up by the wire lobes 3, it hits the lid body 7 or the guide tube 5. Further, when the hanging frame 11 is lifted by the wire lobes 3, the compression coil spring 24 is compressed until it reaches an allowable compression length. Therefore, even with such a configuration, the same effects as those of the above-described embodiments can be obtained.

[Effects of the Invention] As described above, according to the present invention, the reverberation system can improve the ability to adjust the reverberation time with a simple configuration by ensuring the movement of the sound absorbing material through the opening provided in the ceiling surface. A time adjustment device can be provided.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing a first embodiment of a reverberation time adjustment device according to the present invention, Fig. 2 is a block diagram showing a second embodiment of the present invention, and Fig. 3 is a block diagram showing a sound absorbing material in the same embodiment. 4 is a sectional view taken along line A-A in FIG. 3, and FIGS. 5 and 6 are sectional views showing the support structure in detail.
FIG. 7 is a configuration diagram showing a fifth embodiment of the present invention, and FIG. 8 is a configuration explanatory diagram of a conventional reverberation time adjustment device. 1...Ceiling surface, 2...Opening, 3...
... wire rope, 4 ... sound absorbing material, 5 ...
... Guide tube, 6 ... Support device, 7 ...
・Lid body, 8...Rod, 9...Plate, 1
0... Spring, 11... Hanging frame, 12... Bottom plate, 13a, 13b... Rod, 14... Spacer, 15... Rubber plate, 16...Plate, 17...Rod, 18
...Spring, 19...Spring bin. Applicant's representative Patent attorney Takehiko Suzue (A) Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 7 (A) Figure 8 (C)

Claims (1)

[Claims] In a device that suspends a sound absorbing material from an opening provided in the ceiling of a theater, etc. and adjusts the reverberation time depending on the amount of protrusion from the ceiling, the sound absorbing material is attached to the lowest part of the sound absorbing material via an elastic body such as a spring. 1. A reverberation time adjustment device, comprising: a lid body which is arranged such that when the sound absorbing material is lifted upward, the lid body comes into contact with the ceiling surface and closes the opening portion.