JPH0720313B2 - Speaker - Google Patents

Description

TECHNICAL FIELD The present invention controls the pressure difference between the inside and the outside of a cone suspension of a speaker to constantly expand the surface of the cone suspension, so that a large amplitude vibration occurs when a small cabinet is mounted. Even so, it is a speaker system that prevents the cone suspension from generating abnormal noise.

2. Description of the Related Art In recent years, audio equipment has been significantly miniaturized due to the progress of semiconductor technology and the advent of high-performance small circuit components. The speaker system is becoming smaller, regardless of whether it is a home-use system or an in-vehicle system. However, the lowest resonance frequency (hereinafter referred to as _OB ) of the speaker system in which the speaker is mounted in a small cabinet is a box caused by the cabinet volume. Due to the stiffness, it is significantly higher than the lowest resonance frequency of the speaker itself (hereinafter referred to as _O ). Therefore, the acoustic characteristics in the low frequency range were deteriorated. Here, in order to improve the acoustic characteristics in the low frequency range, a subwoofer system or the like found in the 3-Dimensional speaker system has been conventionally used.

The speaker system found in the subwoofer system described above will be described below with reference to the drawings.

FIG. 4 is a sectional view of a speaker system mounted in a small cabinet. In FIG. 4, 1 is a bottom plate, 2 is a ring-shaped magnet, 3 is a top plate, and the bottom plate 1 and the top plate 3 hold the magnet 2 to form an annular magnetic gap 4. Reference numeral 5 denotes a frame fixed on the top plate 3.

Reference numeral 6 is a voice coil, and 7 is a voice coil bobbin around which the voice coil 6 is wound, and the voice coil 6 is hung on the frame 5 via a corrugated damper 8 so that the voice coil 6 can vibrate in the magnetic gap 4. Reference numeral 9 is an inverted-head-shaped cone paper, and its lower portion is fixed near the upper end of the voice coil bobbin 7,
The outer peripheral portion is suspended from the frame 5 via a roll edge 10 having a semicylindrical cross section. Reference numeral 11 is a gasket that reinforces the outer peripheral pasting portion of the roll edge 10. 12 is a dust cap that closes the hole in the center of the cone paper 9. Reference numeral 13 is a diaphragm formed from the cone paper 9 and the dust cap 12. The speaker 14 is constituted by the above, and the cabinet 15
Is attached to.

The operation of the conventional speaker system configured as above will be described below.

Bottom plate 1, magnet 2 and top plate 3
When a signal current flows through the voice coil 6 in the magnetic air gap 4 formed in, the voice coil 6 vibrates according to the signal current. This driving force is transmitted by the voice coil bobbin 7 to the vibrating plate 13 including the cone paper 9 and the dust cap 12, and the vibrating plate 13 generates compression waves before and after the vibration. The roll edge 10 has a function of supporting the diaphragm 13 so as to vibrate together with the voice coil bobbin 7, and also has a function of separating front and rear compression waves together with the cabinet 15.

Problems to be Solved by the Invention However, the above-described configuration has the following problems.

Now, the effective vibration area of the diaphragm is S _D , the displacement amount before and after the diaphragm is X, the space volume closed by the cabinet and the diaphragm at rest is V _O , the atmospheric pressure in the cabinet at that time is P _O , and The atmospheric pressure in the cabinet when the diaphragm is displaced X in the front and back
Equations (1) to (3) hold if P _F and P _B are used.

P _O V _O = P _F (V _O + S _D・ X) = P _B (V _O -S _D・ X) …… (1) That is, when the diaphragm is displaced forward, the pressure P _F in the cabinet becomes lower than atmospheric pressure, and when the diaphragm is displaced backward, the pressure P _B in the cabinet becomes high.

Here, in the case of a so-called upper roll in which the roll edge 10 is arranged in a convex shape as shown in FIG. 4, even if the diaphragm is displaced rearward and the pressure in the cabinet rises, the roll edge 10 is locally localized. It does not deform and generate abnormal noise. This is because the shape is optimal when the internal pressure of the circular cylinder is higher than the external pressure. However, when the diaphragm is displaced forward and the atmospheric pressure in the cabinet is lowered, the roll edge is locally deformed (reverse vibration), and an abnormal sound is generated.

This problem is likely to occur in a subwoofer system for reproducing a low frequency range having a small cabinet volume and a 3-Dimensional speaker system for a vehicle.

The present invention has been made in view of the above problems, and provides a speaker system in which a speaker is mounted in a small cabinet and the cone suspension does not generate an abnormal sound even when vibrating at a large amplitude.

Means for Solving the Problems In order to achieve this object, a speaker system of the present invention has a diaphragm vibrating according to an input signal and two edges having a semi-cylindrical cross section on the outer periphery of the diaphragm. And a cone suspension joined to each other in the opposite direction and at least between the outer circumferential side margins of the edges through a spacer having at least one or more one-way air flow regulating valve, and the one-way air flow regulating valve is Rectifying the change in atmospheric pressure caused by the vibration of the diaphragm so that the press-fit inside the cone suspension is equal to or lower than the internal pressure of the cabinet in which the speaker is mounted and the atmospheric pressure outside the speaker system. It is configured by It is configured by setting the direction to be equal or higher.

Operation According to this configuration, a large change in atmospheric pressure occurs inside the cabinet due to the diaphragm vibrating with a large amplitude due to the input signal, particularly the low-range signal, and the cabinet. By rectifying this change in atmospheric pressure, the two edges with a semi-cylindrical cross section are introduced into the internal space of the cone suspension that is constructed in the opposite direction, and the pressure on the inner diameter side of the semi-cylindrical edge is the pressure on the outer diameter side. By setting the value equal to or higher than, no contraction force is generated on the edge surface toward the inner diameter side. Therefore, it is possible to prevent the edge from reciprocally vibrating and generating an abnormal sound even when a large amplitude vibration occurs.

Embodiment An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view of a speaker system according to an embodiment of the present invention.

In FIG. 1, 16a and 16b are roll edges having semi-cylindrical cross-sections, which are arranged in mutually opposite directions so that the convex portions of the edges face each other, and the inner peripheral side pasting portion is the outer peripheral portion of the cone paper 17. It is fixed to the fixed edge fixing ring 18, and is fixed to the frame 21 via a spacer 20 having at least one or more one-way air rectifying valve 19 between the outer peripheral side bonding margins. 22 is a bottom plate, 23 is a magnet, 24 is a top plate, 25 is a magnetic gap, 26 is a voice coil, and 27 is a voice coil.
Is a voice coil bobbin, 28 is a dust cap, 29 is a diaphragm consisting of the cone paper 17 and the dust cap 28, 30 is a speaker made up of the above, and 31 is a cabinet, which have the same configurations as in the conventional example. Reference numeral 32 is a damper in which a cylindrical body having a rectangular cross section is continuously arranged in the circumferential direction, and the voice coil bobbin 27 is hung on the frame 21 via this damper. The cone suspension 33 includes an edge fixing ring 18 and two opposite roll edges 16a and 16b.
And a one-way air rectifying valve 19 and a gasket 20.

The operation of the speaker configured as above will be described below. The diaphragm 29 vibrates back and forth as described in the explanation of the operation of the conventional example. This diaphragm 29 is a cone suspension 33 and a damper fixed to the voice coil bobbin 27.
It is suspended by 32 so that it can vibrate. Here, in the one-way air rectifying valve 19, the internal pressure of the cone suspension 33 (hereinafter referred to as P _s ) is equal to the internal pressure of the cabinet 31 (hereinafter referred to as P _c).
If it is higher than that, it is opened, and in the opposite case it is closed. Now, suppose the diaphragm 29 vibrates before. In this case, P _c is lower than the atmospheric pressure (hereinafter referred to as P _a ) outside the speaker system, and if P _s is higher than P _c (for example, at the time of the first vibration or when the vibration is excessive than before). , The one-way air rectifying valve 19 is opened so that P _s becomes the same as P _c, and vice versa.
If P _s is lower than P _c , it is closed. Therefore, the respective pressure relationships are as shown in equation (4).

P _s ≤P _c <P _a (4) On the contrary, when the diaphragm 29 vibrates later, the equal sign of the equation (5) holds only at the beginning and the inequality sign holds after that.

P _s ≤ P _a <P _c (5) Therefore, in the case of the cone suspension in which the convex surfaces of the roll edges shown in Fig. 1 face each other, P _s is always
Since it is lower than or equal to P _c and P _a , in other words, the pressure inside the cone suspension, which is composed of two roll edges of a semi-cylinder, is the internal pressure of the cabinet and the atmospheric pressure outside the speaker system. The roll hedge surface is in tension because it is equal to or less than.

As described above, according to the present embodiment, the diaphragm vibrating according to the input signal and the semicircular cylindrical cross section on the outer periphery of the diaphragm.
A cone suspension in which a plurality of edges are joined in opposite directions and at least between the outer peripheral side margins of each edge via a spacer having at least one or more one-way air flow regulating valve to form a space inside The one-way air rectifying valve rectifies the change in atmospheric pressure generated by the vibration of the diaphragm so that the pressure inside the cone suspension is the internal pressure of the cabinet in which the speaker is mounted and the outside of the speaker system. By setting it so that it is equal to or lower than the atmospheric pressure of, the surface of the roll edge can be put in a tension state, and the speaker is mounted in a small cabinet to roll even when the speaker system has a large amplitude. It is possible to prevent the edge from reciprocally vibrating and generating an abnormal sound.

Another embodiment of the present invention will be described below with reference to the drawings. FIG. 2 (a) is a sectional view of a cone / suspension portion of a speaker according to another embodiment of the present invention.
FIG. 2B is a cross-sectional shape of the edge used in FIG. 2A at the time of molding one sheet. In FIG. 2 (b), the edge
34a is composed of a sloped surface 35a of a truncated cone, and an outer peripheral side bonding margin 36a and an inner peripheral side bonding margin 37a provided at the upper and lower ends thereof. In FIG. 2 (a), the above-mentioned edges are bent into V-shapes which are opposite to each other when assembling two sheets, and each inner peripheral side margin (37a, 37b) is an edge fixing ring fixed to the outer peripheral portion of the cone paper 38. It is stuck to 39. Further, the outer peripheral side pasting margin (36a, 36b) of each edge is a spacer having at least one or more one-way air rectifying valve 40.
It is fixed to the frame 42 via 41. 43 is the above-mentioned cone suspension.

The operation of the speaker cone suspension configured as described above will be described below. The two edges 34a, 34b bent into a V shape are deformed by the vibration of the diaphragm while sequentially moving the bent portion in the radial direction on the edge surface. The diaphragm 38 as described in the first embodiment.
The pressure change inside the cabinet caused by the vibration of the
Since the internal pressure P _{s of} 43 is equal to or lower than the other pressures (P _a , P _c ), the surface of the edge (34a, 34b) and the bent portion are tensioned in an arc shape as shown by the dotted line in the figure. Become.

As described above, according to the present embodiment, two edges, each of which is composed of a sloped portion of the truncated cone and upper and lower end surfaces thereof, and which is a bonding margin, are bent in opposite V-shapes at the time of assembly, and at least the outer circumference of each edge is formed. A cone suspension that forms a space inside, which is joined via a spacer having at least one or more one-way air rectifying valve between the side attachment margins, and the one-way air rectifying valve is provided with the vibration of the diaphragm. The pressure inside the cone suspension is set to be equal to or lower than the internal pressure of the cabinet in which the speaker is mounted and the atmospheric pressure outside the speaker system by rectifying the change in atmospheric pressure generated by As a result, in a speaker system in which the surface of the V-shaped edge is in a tensioned state and the speaker is mounted in a small cabinet, the edge is inverted and vibrated even at a large amplitude. In addition to preventing the generation of ordinary noise, the radial movement of the bent portion can be smoothly moved without generating abnormal noise, and vibration with a larger amplitude than the roll edge can be generated. It is a thing.

In each of the embodiments, the cone suspension has two edge convex surfaces facing each other, but the concave surfaces are opposed to each other, and the rectifying direction of the one-way air rectifying valve is set to be opposite. For example, as shown in FIG. 3, the concave surfaces of the roll edges 34a and 34b are opposed to each other, and the inner peripheral side adhesive margins 37a and 37b are directly fixed to the outer periphery of the cone paper 38, and the outer peripheral side adhesive margins 36a and 36b. Spacer 41 with one way air rectifying valve 40 in between
Even if the rectification direction of the air rectification valve is fixed to the frame 42 via the, the oscillating system mass can be reduced in weight by the edge fixation ring and the same effect can be obtained. .

EFFECTS OF THE INVENTION The present invention provides a diaphragm that vibrates according to an input signal, and two edges having semi-cylindrical cross-sections on the outer periphery of the diaphragm in opposite directions, and at least the outer peripheral side margin of each edge Cone forming a space inside by joining through a spacer having at least one or more one-way air flow regulating valve between
A suspension, the one-way air rectifying valve, by rectifying the change in atmospheric pressure generated by the vibration of the diaphragm,
By setting the pressure inside the cone suspension to be equal to or lower than the internal pressure of the cabinet in which the speaker is mounted and the atmospheric pressure outside the speaker system, the edge surface is tensioned, and the inside of the cabinet is tensioned. The present invention realizes a speaker system of a small cabinet that prevents an edge from oscillating and generating an abnormal sound even when a large pressure change occurs. Further, as an edge forming the cone suspension, there are pasting margins on the sloped portion and the upper and lower end surfaces of the truncated cone, and by using two edges which are bent and bent in a V shape at the time of assembly, a larger amplitude vibration is possible and abnormal noise is generated. It is possible to realize a speaker system that can prevent the occurrence.

[Brief description of drawings]

FIG. 1 is a sectional view of a speaker according to an embodiment of the present invention,
FIG. 2 (a) is a sectional view of a cone suspension portion of a speaker in another embodiment of the present invention, FIG. 2 (b) is a sectional view of the edge used in FIG. 2 (a) at the time of molding, FIG. 3 is a sectional view of a cone suspension portion of another embodiment of the present invention, and FIG. 4 is a sectional view of a speaker mounted in a conventional small cabinet. 16a, 16b …… Roll edge, 17 …… Cone paper, 18 …… Edge fixing ring, 19 …… One-way air rectifying valve, 20 …… Spacer, 21 …… Frame, 33 …… Cone suspension.

 ─────────────────────────────────────────────────── ─── Continued front page (72) Inventor Kosaku Murata 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (72) Inventor, Mitsuru 1006 Kadoma, Kadoma City, Osaka Prefecture

Claims (2)

[Claims] 1. A diaphragm vibrating in response to an input signal, and two edges having semi-cylindrical cross-sections on the outer periphery of the diaphragm which are opposite to each other, and at least an outer peripheral margin of each edge. , A cone that forms a space inside through a spacer having at least one or more one-way air rectifying valve
A suspension, the one-way air rectifying valve, by rectifying the change in atmospheric pressure generated by the vibration of the diaphragm,
A speaker characterized in that the pressure inside the cone suspension is set to be equal to or lower than the internal pressure of a cabinet in which the speaker is mounted and the atmospheric pressure outside the speaker system. 2. A sloped portion of a truncated cone and two edges each having a bonding margin provided on the upper and lower end surfaces thereof are bent into V-shapes which are opposite to each other during assembly, and at least an outer peripheral bonding margin of each edge. And a cone suspension forming a space inside, which is joined via a spacer having at least one or more one-way air flow regulating valve, and the one-way air flow regulating valve is provided with an air pressure generated by vibration of the diaphragm. 2. The pressure inside the cone suspension is set to be equal to or lower than the internal pressure of the cabinet in which the speaker is mounted and the atmospheric pressure outside the speaker system by rectifying the change in the above condition. Speaker.