JPH0354472Y2 - - Google Patents

Description

[Detailed explanation of the idea] [Industrial application field] The present invention relates to a speaker cabinet.

[Prior Art] Conventionally, methods have been put into practical use to increase the mechanical strength of the box itself by attaching reinforcing crosspieces or reinforcing rods to the cabinet, and to disperse and control the plate vibrations of the full plate, side plate, and back plate. However, among these, there is a method for damping plate vibration of a full plate, for example, Utility Model Application No. 58-147376
There is a publication.

The device described in the same publication has a narrow groove in the board thickness direction around the speaker unit of the full board.
It has a structure in which this groove is filled with a viscoelastic material such as rubber.

[Problems to be solved by the invention] One of the causes of plate vibration of the buttful plate is the reaction of the speaker unit, but since the conventional structure is a structure in which grooves are provided in the buttful plate, the mechanical strength of the buttful plate is becomes smaller. Therefore, the buffer plate, which serves as a reference for the sound source (speaker unit), vibrates and radiates sound more easily, so the sound from the buffer plate is superimposed on the sound from the speaker unit, and the response characteristics of the system are affected. There were problems that led to deterioration of transient characteristics and distortion characteristics.

The present invention aims to solve these problems.

[Means for Solving the Problems] The present invention provides a speaker cabinet in which a bump-full plate is joined to the front surface of a cabinet structure consisting of each side plate, and the inner periphery of the joint end face is attached to the joint end face of the cabinet structure. A reinforcing member is provided in which a step is cut out to a predetermined depth from the surface side of each side plate, leaving a portion, and both ends of the first reinforcing member and the second reinforcing member are joined by a connecting member. Equipped with
The first reinforcing member of the reinforcing member is attached to the inner side of the outer circumferential portion of the buffle plate that is joined to the joint end surface of the cabinet structure, the baffle plate is fitted into the front face of the cabinet structure, and the second A reinforcing member is bonded to the inside of the inner periphery of the joint end surface of the cabinet structure, thereby forming a slit-like groove along the entire circumference at the joint between the buttful plate and the cabinet structure. It is something.

[Function] According to the above configuration, (a) the path through which the vibration from the baffle plate propagates to the side plate via the slit-shaped groove portion changes the cross-sectional area of the medium through which the vibration propagates in the slit-shaped groove portion. According to research by Cremer et al., when vibrations propagate to media with different characteristic impedances, that is, when the cross-sectional area of the medium is changed, the amount of attenuation of longitudinal waves and bending waves due to changes in plate thickness is as shown in Figure 2. For example, the ratio of cross-sectional areas becomes
10, longitudinal waves are attenuated by about 5 dB and bending waves are attenuated by about
Attenuates by 7.5dB. (b) In addition, the reinforcing member is separated at a portion other than both ends where the first reinforcing member and the second reinforcing member are joined by the coupling member, and the first reinforcing member and the second reinforcing member
Since the second reinforcing members are vibration-insulated from each other, not only the vibration damping effect is remarkable, but also the vibration damping effect of the slit-shaped groove is not impaired. (c) Since the front part of the cabinet structure is assembled by fitting the buttful plate to which reinforcing members are attached in advance, workability is good and the mechanical strength after assembly is sufficient.

[Example] This will be explained in the drawings from FIG. 1 onwards.

In a structure in which a cabinet structure 3 is constituted by the top, bottom, left and right plate sides 2, 2, 2, 2, and a buttful plate 1 is joined to the front part of this cabinet structure 3, the joint end surface of the cabinet structure 3 4
A cutout step 5 is provided at a predetermined depth from the surface side of each side plate 2, 2, 2, 2, leaving the inner circumference 4a of the joint end surface 4.

On the other hand, reinforcing members 6, 6 each having a rectangular cross section are attached to the inside of the outer circumferential portion of the baffle plate 1, that is, to the inside of the portion to be joined to the joint end surface 4 of the cabinet structure 3.

Then, the frame-shaped reinforcing members 6, 6 are fitted inside the cabinet structure 3, and the baffle plate 1 is joined to the front surface of the cabinet structure 3 to assemble it.

With such a structure, a slit-like groove 7 is formed around the entire circumference at the joint between the buffle plate 1 and the cabinet structure 3.

It is desirable that the depth of the slit-shaped groove 7 be as long as possible in view of the vibration damping effect, but on the other hand, this reduces the mechanical strength of the cabinet. Therefore, in reality, the depth of the slit-like groove 7 is determined from the balance between the vibration damping effect and the mechanical strength of the cabinet.

Next, an embodiment in which the depth of the slit-like groove 7 is set to 1/4 of the thickness of the side plate 2 will be described. In this example, the dimensions of each part of the cabinet (unit: mm)
(Fig. 3) is determined as follows, outer diameter 380W x 670H x 320D t1 = 25, t2 = 20, l1 = 1, l2 = 5, l3 = 18, l4 = 25 A speaker unit is placed in the center of the full board 1. A vibrator 10 of the same structure is attached, and this vibrator 10 applies impulse vibration to the center point P of the back plate.
The plate vibration response waveform was measured.

FIG. 5 shows the measurement results of the conventional example (without slit-like grooves), and FIG. 6 shows the measurement results of the present example.

FIG. 4 shows another specific example of the reinforcing member 6, in which a first reinforcing member 8a having a triangular cross section and a second reinforcing member 8b having the same shape are connected to connecting members 9, 9 at both ends thereof. Therefore, it has a bonded structure. The first reinforcing member 8a is attached to the inner side of the outer peripheral portion of the baffle plate 1 that is joined to the front surface of the cabinet structure 3, and the second reinforcing member 8b
is joined to the inside of the front surface of the cabinet structure 3.

The connecting members 9, 9 may be made of wood, plastic, or a viscoelastic material such as foamed neoprene rubber or low-hardness neoprene rubber.

In an embodiment using such a reinforcing member 6, the first reinforcing member 8a and the second reinforcing member 8b
are separated at a portion other than both ends connected by connecting members 9, 9, and both reinforcing members 8a, 8b
are vibration isolated from each other. Therefore, vibrations propagating from the buff-full plate 1 to the side plates 2, 2, 2, 2 through the first reinforcing member 8a and the second reinforcing member 8b are significantly reduced.

[Effects of the invention] The present invention has the following features: (a) Vibrations propagated from the speaker unit as a vibration source to the top plate, left and right side plates, and bottom plate through the buff-full plate and slit-shaped grooves are attenuated by the slit-shaped grooves. (b) As a result, the top plate,
Plate vibration of the left and right side plates, bottom plate, and back plate is significantly reduced, and deterioration of various characteristics caused by plate vibration is improved.
(c) Since the cabinet in which the slit-shaped groove is formed all around the circumference is reinforced by the reinforcing member, the mechanical strength of the cabinet is increased. Since the reinforcing members are vibration-insulated from each other, the vibration damping effect of the slit-like grooves is not impaired, and (e) the structure is such that the buttful plate to which the reinforcing members are attached in advance is joined to the front part of the cabinet structure. Therefore, it is easy to assemble.

[Brief explanation of the drawing]

Figure 1 shows the structure of the speaker cabinet of the present invention, Figure 2 shows the attenuation (theoretical values) of longitudinal waves and bending waves due to changes in plate thickness, and Figure 3 shows the same parts. FIG. 4 is a diagram showing the structure of another specific example of the reinforcing member, FIG. FIG. 6 is a vibration response waveform diagram at the center point of the back plate to an impulse of the speaker cabinet of the present invention (one embodiment). DESCRIPTION OF SYMBOLS 1... Buff full plate, 2... Side plate, 3... Cabinet structure, 4... Joint end surface of the cabinet structure, 4a... Inner peripheral part, 5... Notch step, 6
...Reinforcement member, 7...Slit-shaped groove.

Claims (1)

[Scope of utility model registration request] In a speaker cabinet in which a baffle plate 1 is bonded to the front surface of a cabinet structure 3 consisting of side plates 2, 2, 2, 2, an inner circumferential portion 4 of the bonded end surface 4 is attached to a bonded end surface 4 of the cabinet structure 3.
A cutout step 5 is provided by cutting out a predetermined depth from the surface side of each side plate 2, 2, 2, 2, leaving a portion a, and both ends of the first reinforcing member 8a and the second reinforcing member 8b are The first reinforcing member 8a of the reinforcing member 6 is connected to the outer periphery of the baffle plate 1 to be joined to the joining end surface 4 of the cabinet structure 3. The buff-full plate 1 is fitted to the front surface of the cabinet structure 3, and the second reinforcing member 8b is attached to the inner circumference 4a of the joint end surface 4 of the cabinet structure 3.
By joining the inside of the
A speaker cabinet characterized in that a slit-like groove 7 is formed around the entire circumference at the joint between the speaker cabinet and the cabinet structure 3.