JP2624890B2 - Reverberation time adjustment device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial application field) The present invention relates to a reverberation time adjusting device in a theater, a studio, a music hall, or the like.

(Prior Art) It is well known that when performing in a music hall or the like, there is a difference in the preferred reverberation time depending on the type of musical instrument. For example, it is said that the reverberation time is relatively short for a piano, and longer for a pipe organ.

Generally, the reverberation time in a theater or the like is determined by the volume of the room, the total area of the inner wall of the room, and the sound absorption coefficient of the inner wall. For this reason, in recent years, an apparatus for adjusting the reverberation time by changing the exposed area of the sound absorbing material to change the exposed area of the sound absorbing material and adjusting the reverberation time has been increased in many cases.

As another means for adjusting the reverberation time, a device is proposed in which an opening is provided in the ceiling surface of the theater, a cylindrical sound absorbing material is put in and out of the opening, and the reverberation time is adjusted by the amount of protrusion. Have been.

FIG. 8 shows a configuration example of such a reverberation time adjusting device. As shown in FIG. 8, a cylindrical sound-absorbing material 4 is formed through a plurality of openings 2 provided on the ceiling surface 1 at appropriate intervals.
Are suspended by the wire rope 3 so as to be movable in the vertical direction.

In the figure, (A) shows a state in which the sound absorbing material 4 is hung to the bottom, (C) shows a state where it is pulled up above the ceiling surface 1 and does not protrude from the ceiling surface 1, and (B) shows a state in which ) Indicates an intermediate state. Here, in (A), the amount of protrusion H below 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 in this H range. That is, the volume of the room, the total area of the inner wall and the sound absorption coefficient of the inner wall,
Then, the number of the sound absorbing members 4 to be provided and the amount of the projecting amount H are calculated in accordance with the surface area of the protrusion amount H of the sound absorbing member 4 and the sound absorption coefficient. If the protrusion amount H is large, the reverberation time is short, and if H is 0, the reverberation time is long.
The protrusion amount H is adjusted by winding or rewinding by a separately provided wire drum device (not shown).

(Problems to be Solved by the Invention) Incidentally, there is naturally a gap (D-d) between the inner diameter D of the opening 2 provided on the ceiling surface 1 and the outer diameter d of the sound absorbing material 4. Therefore, since the sound in the room escapes from the gap to the space above the ceiling, it cannot be ignored in order to accurately calculate the reverberation time. Since the sound that enters this gap does not return almost completely, it can be considered as a sound absorption surface having a sound absorption coefficient of 100% in calculation.

Therefore, in order to evaluate the change in the reverberation time in the states (A) and (C) of FIG. 8, the size of the gap (D-d) besides the protrusion amount H of the sound absorbing material 4 must be determined. It becomes a problem. If the gap (D-d) is large, the reverberation time hardly changes in an extreme case even if the protrusion amount H changes. For this reason, it is necessary to make this gap as small as possible.

However, as a practical matter, the sound absorbing material 4 is a wire rope 3
A beam provided directly under the roof through the (not shown)
, And is suspended via a pulley or the like (not shown), and the gap between the beam and the ceiling surface 1 is longer than the length of the sound absorbing material 4, so that the sound absorbing material 4 is opened. For reliable operation through the part 2, there must be some gap.

The present invention has been made in view of the above circumstances,
It is an object of the present invention to provide a reverberation time adjusting device capable of ensuring the operation of a sound absorbing material through an opening provided in a ceiling surface and improving the reverberation time adjusting ability with a simple configuration.

[Means for Solving the Problems] In order to achieve the above object, the present invention hangs a sound absorbing material from an opening provided on a ceiling surface of a theater or the like, and projects the sound absorbing material from the ceiling surface. In the device for adjusting the reverberation time by adjusting the sound absorbing material, the opening is attached to the lowermost part of the sound absorbing material via an elastic body such as a spring, and contacts the ceiling surface when the sound absorbing material is lifted upward. In this configuration, a lid for closing the portion is provided.

(Operation) In the reverberation time adjusting device having such a configuration, when the sound absorbing material is lifted from the ceiling surface through the opening, the opening is formed by the lid attached to the lower portion of the sound absorbing material again via the elastic body. Is closed, so that the sound at this time does not escape to the space above the ceiling through the gap between the sound absorbing material and the opening, and the ability to adjust the reverberation time can be enhanced. Further, even if a gap is formed between the opening and the sound absorbing material, the adjustment of the reverberation time is not affected, so that there is no hindrance to the lifting and suspending operations of the sound absorbing material.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings.

FIG. 1 shows the configuration of a first embodiment of the reverberation time adjusting apparatus according to the present invention, and the same parts as those 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 the ceiling surface 1 so as to protrude downward from the ceiling surface 1 with its lower opening end horizontal. A cylindrical sound absorbing material 4 is suspended by the wire rope 3 so as to be vertically movable through each of the guide tubes 5. A disc-shaped lid 7 having a diameter larger than that of the opening 2 is provided on a lower end surface of the sound absorbing material 4 via a support device 6.
Is provided. The support device 6 has a lid 7 attached to a lower end of a rod 8 provided vertically through a through hole formed in the bottom of the case 6a, and a gap between a plate 9 attached to the upper end of the rod 8 and the bottom of the case 6a. Spring inserted in
The cover 10 elastically supports the lid 7 so as to be vertically movable.

In the reverberation time adjusting device thus configured, the spring 10 pushes the plate 9 upward with a force greater than the weight of the lid 7 as shown in FIG. The lid 7 is pressed against 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 of protrusion H from the lower end of the guide tube 5 as shown in the figure. On the other hand, when the sound absorbing material 4 is lifted upward, the lid 7 comes into contact with the lower end of the guide tube 5 as shown in FIG. That is, when the sound absorbing material 4 is lifted by the wire rope 3, the lid 7 pressed against the support device 6 hits the lower end of the guide tube 5, and when further lifted, the spring 10 presses the lid 7 upward. Since the lifting force of the wire rope 3 is set to be greater than the lifting force, the sound absorbing material 4 and the supporting device 6 are pulled upward while the lid 7 is pressed against the guide tube 5.

As a result, the opening 2 in the ceiling surface 1 has the guide tube 5 and the lid 7
Completely occluded. Since the guide tube 5 is generally constructed such that the ceiling surface of a theater or the like is inclined in consideration of acoustic effects and the like, the guide tube 5 is provided to ensure the operation of the lid 7 and a spring. Reference numeral 10 is provided to omit the operation of adjusting the lifting stroke by 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 those in FIG. Second
In the embodiment shown in the figure, a guide tube 5 is inserted into a plurality of openings 2 provided at appropriate intervals in the ceiling surface 1 by protruding downward from the ceiling surface 1 with the lower ends thereof being horizontal. The sound absorbing material 4 is provided through the guide tube 5, and is suspended by the wire rope 3 via the suspension 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 configuration as shown in detail in FIGS.

FIG. 3 is a cross-sectional view for explaining a state in which the sound absorbing material 4 is suspended above the ceiling surface 1, and FIG. 4 is a sectional view of FIG.
It is arrow sectional drawing which follows the -A line. That is, as shown in FIGS. 3 and 4, the bottom plate 12 is fitted to the lower end of the sound absorbing material 4. A pair of rods 13a and 13b provided symmetrically about the central axis penetrate the spacer tube 14 in the hollow portion of the sound absorbing material 4 and are disposed so as to be vertically movable through a hole provided in the bottom plate 12. Have been. This pair of rods
At the lower ends of 13a and 13b, a lid 7 made of a material having a low sound absorption coefficient, for example, metal and having a rubber plate 15 adhered to the back side is fixedly mounted, and a plate 16 is mounted and fixed at the upper end portion. ing. On the other hand, a rod is placed on the central axis of the hollow portion of the sound absorbing material 4.
A lower end 17 is fixed to the bottom plate 12.
The upper end of the rod 17 slidably penetrates a hole provided in the plate 16, and the upper end is connected to the suspension frame 11. In addition, a spring is
18 are provided. In this case, the rod 17 is in contact with a spacer (not shown) at an appropriate interval between the rod 17 and the sound absorbing material 4, and together with the holding function of the bottom plate 12, prevents the sound absorbing material 4 from falling down due to its weight. Also, rods 13a and 13b
A spring pin 19 is driven below the bottom plate 14.

Next, the operation of the thus-configured reverberation time adjusting device will be described.

When the sound absorbing material 4 is suspended from the ceiling surface 1 downward,
Since the lid 7 is pushed up by the spring 18 in a compressed state, the spring pin 19 driven into the rods 13a and 13b is pushed up to a position where it comes into contact with the bottom plate 12. In this case, since the rubber plate 15 is attached to the lid 7 and the rubber plate 15 functions as a vibration damping material, the lid 7 does not resonate due to the large acoustics in the room.

When the sound absorbing material 4 is lifted upward in such a state,
The lid 7 contacts the lower end of the guide tube 5, the bottom plate 12 slides using the rods 13a and 13b as guides, and the rod 17 slides through the hole of the plate 16 to compress the spring 18 while lifting the sound absorbing material 4. Go. Then, when the sound absorbing member 4 reaches a predetermined position and a limit switch (not shown) is operated, the winding of the wire rope 3 is stopped, so that the upward movement of the sound absorbing member 4 is stopped. In this case, an adjustment is made so that the spring 18 stops before reaching the allowable compression length. At this time, the rubber plate 15 is elastically deformed by being sandwiched between the guide tube 5 and the lid 7, and has a function of closing a small gap between the guide tube 5 and the lid 7.

In this manner, the sound absorbing material 4 is lifted and adjusted so as to stop at a predetermined position. However, if the sound absorbing material 4 does not stop, the plate 16 hits the spacer tube 14 so that the wire rope 3 When a heavy load is applied to a hoisting device (not shown), the hoisting device stops. Also,
The spacer 14 has a dimension longer than the allowable compression length of the spring 18 and is provided to protect the spring 18.

As described above, in the second embodiment, it is possible to eliminate the gap between the sound absorbing material 4 and the ceiling surface 1 when the sound absorbing material 4 is lifted, so that the reverberation time can be lengthened. The rubber plate 15 is used for the lid 7.
Has the function of suppressing the vibration of the guide tube 5, and when it comes into contact with the guide tube 5, it is possible to completely close the gap. In addition, since the device for supporting the lid 7 is provided in the hollow portion of the sound absorbing material 4, a decrease in the surface area of the sound absorbing material 4 can be avoided.

In the above-described first and second embodiments, the lid 7 has a disk shape and the sound absorbing material 4 has a cylindrical shape. However, the present invention is not limited to this. Various cross sections such as a square and a rectangle are possible.

In the above embodiment, the guide tube 5 is provided in the opening 2 of the ceiling surface 1 in consideration of use in a theater where the ceiling surface is inclined. However, the cover 7 is directly provided without the guide tube 5. The opening 2 of the ceiling surface 1 may be closed.

FIG. 5 shows a third embodiment of the present invention in which a guide tube is not provided on the ceiling surface. Here, only points different from FIG. 1 will be described. As shown in FIG. 5, the rod 20 suspended from the support device 7 is connected to the lid 7 at a support point 21. The lid 7 is connected to the rod 20 in two directions perpendicular to the axial direction of the rod 20. It is configured to be freely rotatable.

With such a configuration, the lid 7 can close the opening 2 without a gap even if the ceiling surface 1 is inclined. When the sound absorbing member 4 is fixed so as not to rotate in the axial direction, when the cover 7 hits the ceiling surface 1, the direction in which the cover 7 operates is constant. The rotation function may not be provided in a direction other than the direction in which the 7 needs to operate. When the ceiling surface 1 is horizontal, all of these functions are unnecessary, and the lid 7 is fixed to the rod 8 suspended from the support device 7 as described with reference to FIG. It is possible to close the opening 2 of the ceiling surface 1 even with a closed structure.

On the other hand, in each of the above embodiments, a compression coil spring is used to lift the lid 7, but a tension coil spring or a constant load spring 22 may be used as in the fourth embodiment shown in FIG. Instead, sponge rubber or the like may be used. Further, a fixed pulley may be provided above the lid 7, a wire rope having one end fixed to the lid 7, a counterweight may be suspended at the other end, and the lid 7 may always be lifted upward.

In each of the embodiments described above, the case where the elastic body is interposed and supported between the lower part of the sound absorbing material 4 and the lid 7 has been described.
This elastic body is not limited to the lower part of the sound absorbing material,
It is also possible to provide them in other places.

FIG. 7 shows a fifth embodiment of the present invention.
1 shows a configuration of a device that raises and lowers through a hanging frame 11. As shown in FIG. 7, the lid 7 is fixed to the sound absorbing material 4, and the sound absorbing material 4 is attached to the rod 23 and the compression coil spring 24.
And is supported by the suspension frame 11 via the

In such a configuration, when the suspension frame 11 is lifted by the wire rope 3, the lid 7 contacts the guide tube 5. Furthermore, the frame suspended by the wire rope 3
When 11 is lifted, the compression coil spring 24 is compressed until it reaches the 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, reverberation that can improve the ability to adjust the reverberation time with a simple configuration by reliably operating the sound absorbing material through the opening provided in the ceiling surface. A time adjustment device can be provided.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a first embodiment of a reverberation time adjusting apparatus according to the present invention, FIG. 2 is a block diagram showing a second embodiment of the present invention, and FIG. FIG. 4 is a sectional view showing the supporting structure in detail, FIG. 4 is a sectional view taken along line AA of FIG. 3, and FIGS. 5 and 6 are third and fourth embodiments of the present invention.
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 adjusting device. 1 ... ceiling surface, 2 ... opening, 3 ... wire rope,
4 ... Sound absorbing material, 5 ... Guide tube, 6 ... Support device, 7 ...
... Lid, 8 ... Rod, 9 ... Plate, 10 ... Spring,
11 ... hanging frame, 12 ... bottom plate, 13a, 13b ... rod, 14 ... spacer, 15 ... rubber plate, 16 ... plate, 17 ...
Rod, 18 ... spring, 19 ... spring pin.

 ──────────────────────────────────────────────────の Continuing on the front page (72) Inventor Masaki Kaneko 2-4, Suehirocho, Tsurumi-ku, Yokohama-shi, Kanagawa Inside Toshiba Keihin Works

Claims (1)

(57) [Claims] An apparatus for suspending a sound absorbing material from an opening provided on a ceiling surface of a theater or the like and adjusting a reverberation time by an amount of protrusion from the ceiling surface, wherein an elastic material such as a spring is provided at a lowermost portion of the sound absorbing material. A reverberation time adjusting device, comprising: a lid attached via a body and abutting on the ceiling surface to close the opening when the sound absorbing material is lifted upward.