JPS6148319B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a speaker system in which a speaker cabinet is provided with an anti-vibration function.

When the speaker is driven, vibration is generated in the speaker cabinet due to mechanical vibration from the speaker and the influence of sound pressure inside the speaker cabinet.
It has been known for a long time to reduce acoustic characteristics. Therefore, various improvements have been made in the past in order to suppress the above-mentioned vibrations of the speaker cabinet. By the way, in one of the conventional examples, a reinforcing material is interposed between opposing walls of a speaker cabinet, and a rubber is interposed in the longitudinally intermediate portion of the reinforcing material, so that the compressive and tensile stress of the rubber is applied. There are some devices that use the vibration absorption effect to prevent vibrations in a speaker cabinet. Although this configuration has a certain vibration-proofing effect, the vibration-absorbing effect due to the compressive and tensile stress of the rubber is not so high, and it is almost ineffective when the loudspeaker has a high output.

The present invention was devised in view of the above-mentioned circumstances, and it is an object of the present invention to provide a device that can perform vibration isolation of a speaker cabinet extremely reliably.

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

First, in FIG. 1, numeral 1 is a speaker cabinet (hereinafter simply referred to as a cabinet), 2 is a baffle board (or unit board) thereof, and 3 is a rear board thereof. Speaker units such as a tweeter 4, a midrange range 5, and a woofer 6 are attached to the buffer board 2.

Therefore, a reinforcing plate 8 is interposed between the opposing walls of the cabinet 1, that is, for example, between the baffle plate 2 and the back plate 3, and the reinforcing plate 8 is interposed between the reinforcing member 8 and at least one wall, that is, for example, the back plate 3. A vibration absorbing material 9 is interposed between them, which absorbs vibrations by shearing stress. Further, a damping member 10 is attached to the reinforcing member 8 to suppress its free vibration.

In this embodiment, first, a metal rod 12 made of iron or the like is used as the reinforcing material 8, and a rubber 1, which is a viscoelastic material, is used as the absorbent material 9.
3 is used, and as the braking material 10, for example, a rubber layer 14 is used. First, the metal rod 12 has a cylindrical shape, and an adjusting screw 16 is formed on the outer periphery of one end 12a, and a screw hole 17 is formed in the center of the other end 12b. Next, the rubber 13 is constituted by an annular body,
A flanged sleeve 19 is attached to its inner circumference, and a flanged ring 20 is attached to its outer circumference. These rubber 13, sleeve 19, and ring 20 are formed by outsert molding (a method in which rubber is poured into a mold with the sleeve and ring set in the mold).
3 is integrally joined (baked) to the sleeve 19 and ring 20. However, at this time, the rubber 13 flows into the plurality of annular grooves 21 and 22 provided on the outer periphery of the sleeve 19 and the inner periphery of the ring 20, respectively, and are joined together, and the binding force between these three is It's becoming very powerful. Further, a screw 23 is formed on the inner periphery of the sleeve 19 and can be screwed into the screw 16. Next, the rubber layer 1
4 is integrally coupled to the outer peripheral surface of the metal rod 12 by baking or the like. Then, the rubber 13 is attached to the sleeve 19 of the screw 16 on the outer periphery of one end 12a of the metal rod 12.
They are screwed together by a screw 23 on the inner periphery. The sleeve 19 is fixed to the metal rod 12 by a lock nut 25 screwed onto the tip of the screw 16.

In the above state, the rubber 13 portion is inserted into the circular opening 26 provided in the back plate 3 portion, and the flange portion of the ring 20 is screwed to the back plate 3 via a plurality of setscrews 27. has been done. Note that the outside of the opening 26 is sealed by a sealing plate 29 screwed to the back plate 3 via a plurality of set screws 28. The other end 12b of the metal rod 12 is fixed to the back surface of the buffle plate 2 via a set screw 30 which is inserted through the buffle plate 2 and screwed into the screw hole 17. At this time, a reinforcing member 31 such as an L-shaped angle is attached to the back of the full board 2, and the metal rod 12 is attached to the reinforcing member 31. You can let them touch each other. Further, a hexagonal hole 32 is formed in the center of one end 12a of the metal rod 12,
By inserting a tool such as a wrench into this hexagonal hole 32 and rotating the metal rod 12, the metal rod 12 and the sleeve 19 are pulled together as shown in FIG. The movement is adjusted to the left and right (directions moving away from each other). That is, the reinforcing member 8 is tensioned and attached between the baffle plate 2 and the back plate 3 via the vibration absorbing member 9 using screws 16 and 23 as tensioning means.

According to the above-described structure, vibration occurs in the cabinet 1 as the speaker is driven, and the baffle plate 2 and the back plate 3 tend to vibrate in opposite directions. Bar 12
When the rubber 13 tries to vibrate in the directions of arrows A and B, shear forces in the directions of arrows a and b act on the outer and inner peripheral surfaces of the rubber 13. In response to this shearing force, the rubber 13 generates shearing stress in the directions of arrows a' and b', and this shearing stress causes the back plate 3 and metal rod 12 to vibrate in the directions of arrows A and B. is absorbed, and vibration of the cabinet 1 is prevented.

However, at this time, the compressive and tensile stress of the rubber 13 does not cause slippage between molecules, but the shear stress of the rubber 13 causes slippage between the levers, and the force is most likely to change into heat. Therefore, the vibration absorption effect due to shear stress is much higher than the vibration absorption effect due to compressive and tensile stress of the rubber 13. As a result, Cabinet 1
It is possible to extremely reliably prevent (brake) vibrations.

Moreover, at this time, the reinforcing material 8 is installed under tension in advance between the buttful plate 2 and the back plate 3 via the vibration absorbing material 9, and Since the housing and the back plate 3 are firmly fastened, the rigidity of the cabinet 1 is extremely high, and vibration prevention due to high pressure is improved.

Moreover, as a result of attaching the reinforcing material 8 between the bumpy plate 2 and the back plate 3 with tension in advance via the vibration absorbing material 9, it is possible to apply shear stress to the vibration absorbing material 8 in advance. Therefore, when the back plate 3 and the metal rod 12 vibrate in opposite directions as the speaker is driven, the shear stress shown in FIG. It is possible to obtain strong braking force to instantly dampen vibrations.

On the other hand, as the cabinet 1 vibrates, the metal rod 12
generates so-called "squeal" due to free vibration, but since the rubber layer 14 provided on the outer peripheral surface of this metal rod 12 damps the free vibration, this metal rod 1
No. 2 "squeal" does not occur at all. Note that this rubber layer 14 may be, for example, a foam layer made of foamed material of various materials.Although only one reinforcing material 8 is shown in the drawing, the more reinforcing materials 8 are used, the better the vibration-proofing effect of the cabinet 1 becomes. It gets expensive. Although it varies depending on the size of the cabinet 1, four reinforcing members 8 are usually used, two reinforcing members 8 arranged one above the other.

In addition, the rubber 1
3 can be adopted.

Although the embodiments of the present invention have been described above, the reinforcing material 8 referred to in the present invention is not limited to the metal rod 12 shown in the embodiments, but may also include various other metal materials, wood, plastic materials, etc. Non-metallic materials can be used. Similarly, various viscoelastic substances can be used as the vibration absorbing material 9.

As described above, the present invention is a structure in which a reinforcing member is tensioned and attached between a pair of walls of a speaker cabinet via a vibration absorbing material made of a viscoelastic material using a tensioning means, and the reinforcing material and the vibration absorbing material are Since the pair of walls can be firmly tightened together through the
It is possible to improve vibration prevention due to high pressure.

Further, as a result of attaching the reinforcing material between the pair of walls under tension in advance via the vibration absorbing material, it is possible to apply shear stress in advance to the vibration absorbing material made of a viscoelastic substance. Therefore, when the pair of walls vibrates against each other due to speaker drive, further shear stress is applied to the vibration absorbing material to which initial shear stress has been applied in advance, and the vibration of the pair of walls is instantly damped. A strong braking force can be obtained, and the vibrations of a pair of walls can be damped instantly.

Therefore, according to the present invention, the vibration-proofing effect of the speaker cabinet is extremely high, works reliably even with high output from the speaker, and the acoustic characteristics of the speaker system can be significantly improved.

Furthermore, according to the present invention, since the damping material is attached to the reinforcing material to suppress the free vibration of the reinforcing material, so-called "squeal" due to the free vibration of the reinforcing material does not occur at all, and noise and acoustic characteristics are improved. Occurrence of disturbance, etc.
There are no adverse effects due to the provision of the reinforcing material.

[Brief explanation of the drawing]

The drawings show embodiments of the invention,
Figure 1 is a sectional view of the speaker cabinet, Figure 2 is a sectional view of the main parts of the same as above, and Figure 3 or 2 is a cross-sectional view of the speaker cabinet.
4 is a cross-sectional view taken along the line -- in FIG. 2, and FIG. 5 is an enlarged cross-sectional view of a main part illustrating the vibration absorption effect due to shear stress. In addition, in the symbols used in the drawings, 1... speaker cabinet, 2... buffer board (or unit board), 3... back plate, 8... reinforcing material, 9... vibration absorbing material, 12... metal rod, 13... rubber , 10... Braking material, 14... Rubber layer, 16, 23... Screws serving as tension means.

Claims (1)

[Claims] 1 A reinforcing material is interposed between a pair of opposing walls of the speaker cabinet, and a vibration absorbing material made of a viscoelastic material and having a vibration absorbing effect by shear stress is placed between the reinforcing material and at least one wall. A speaker system in which the reinforcing member is tensioned between the pair of walls by means of a tensioning means via the vibration absorbing member, and the reinforcing member is provided with a damping member for suppressing free vibration thereof.