JP7141906B2 - Diaphragms and loudspeakers for loudspeakers - Google Patents

Description

The present invention relates to a loudspeaker diaphragm and a loudspeaker having the same.

The high-range reproduction limit frequency of cone-type speakers, which are the most common speakers, is determined by the weight of the vibration system, the Young's modulus (rigidity) of the diaphragm, and the half apex angle of the diaphragm at the joint between the diaphragm and voice coil. However, if a shallow diaphragm with a low total height is used for the purpose of making the speaker thinner, the half apex angle of the shallow diaphragm increases, so the high-range reproduction limit frequency becomes lower, and the reproduction frequency of the speaker becomes lower. There was a problem that the band became narrow.

On the other hand, in the speaker diaphragm described in Patent Document 1, injection molding of engineering plastics such as polyarylsulfone and polyetherimide spreads radially on the diaphragm and extends from the center of the diaphragm toward the outer periphery. Since the rigidity of the central part of the diaphragm is high even with a shallow diaphragm, the high-range reproduction limit frequency is as high as that of a deep diaphragm. In addition, since the rigidity of the diaphragm gradually decreases from the center to the outer periphery of the diaphragm, as the frequency increases, split vibration gradually occurs from the outer periphery of the diaphragm. Abrupt peak dips can be reduced. As a result, it is possible to use a shallow diaphragm and widen the reproduction frequency band of the speaker while reducing the thickness of the speaker.

Japanese Utility Model Laid-Open No. 3-46296

However, in the speaker diaphragm described in Patent Document 1, the reinforcing rib is connected to the joint with the voice coil at the center of the diaphragm. Since the opposite side of the convex surface of the reinforcing rib is concave, when the reinforcing rib is connected to the joint with the voice coil, the rigidity of the center portion of the diaphragm is lowered, resulting in an adverse effect.

The present invention has been made in view of the circumstances as described above, and an object thereof is to provide a diaphragm obtained by hot-pressing a sheet-like base material, using a shallow diaphragm to achieve a thin speaker. To provide a diaphragm for a loudspeaker capable of widening the reproduction frequency band of the loudspeaker while improving the efficiency.

A diaphragm for a loudspeaker according to the present invention as a means for achieving the above-mentioned object has a cone-shaped diaphragm main body made of a sheet-like base material, and the diaphragm main body is attached to the diaphragm main body. a reinforcing rib having a convex surface on one side and a concave surface on the other side of the surface on the sound emitting side and the back surface on the side opposite to the sound emitting side of the diaphragm body, the reinforcing rib spreading radially on the diaphragm body, A diaphragm for a speaker, the height of which gradually decreases from the center to the outer periphery of the diaphragm body, and is spaced apart from the joint with the voice coil at the center of the diaphragm body. hand,
A cap covering a central portion of the diaphragm main body is provided, the cap has a dome-shaped cap main body, and a joint portion with the diaphragm main body is formed on an outer periphery of the cap main body, A second reinforcing rib extending radially along the reinforcing rib is formed at the joint portion with the diaphragm main body portion, and the joint portion with the diaphragm main body portion is formed at the joint portion with the diaphragm main body portion with the reinforcing rib. It is characterized in that it is joined with the second reinforcing rib in an overlapping state .

In the case of a diaphragm formed by heat-pressing a sheet-like base material, the opposite side of the convex surface of the reinforcing rib is concave, but the reinforcing rib is spaced apart from the joint with the voice coil in the center of the diaphragm body. Therefore, it is possible to increase the rigidity of the central portion of the diaphragm formed by heat-pressing a sheet-like base material.

According to the present invention, it is possible to widen the reproduction frequency band of the speaker while reducing the thickness of the speaker by using a diaphragm formed by heat-pressing a sheet-like base material and using a shallow diaphragm. .

1 is a plan view showing a loudspeaker having a loudspeaker diaphragm according to an embodiment of the present invention; FIG. FIG. 2 is a cross-sectional view taken along the line AA of FIG. 1; 3 is an enlarged view showing the left half of the diaphragm and the left half of the cap in FIG. 2; FIG. 4A is a plan view of the diaphragm, and FIG. 4B is a plan view of the cap. 5(A) is an enlarged view showing the left half of the diaphragm on the AA cross section of FIG. 4(A), and FIG. 5(B) is the left side of the cap on the AA cross section of FIG. 4(B). It is an enlarged view showing a half. 2 is a frequency characteristic diagram of the speaker of FIG. 1 and a speaker of a comparative example; FIG.

An example of a loudspeaker having a loudspeaker diaphragm according to an embodiment of the present invention will be described below with reference to the drawings. In addition, this invention is not limited by embodiment shown below.

As shown in FIGS. 1 and 2, a speaker 1 includes a magnetic circuit 2 having a magnetic gap 2a, a frame 3 coupled to the magnetic circuit 2, a voice coil 4 disposed within the magnetic gap 2a, and a voice coil 4 is wound around the outer peripheral surface of the lower end portion, and a cone whose center portion is connected to the voice coil 4 via the bobbin 5 and whose outer peripheral portion is supported by the frame 3 via the edge portion 61. A diaphragm 6, a dome-shaped cap 7 covering the center of the diaphragm 6, a corrugation damper 8 interposed between the bobbin 5 and the frame 3, and the frame 3 made of insulating synthetic resin. and a pair of terminals 10 for external connection electrically connected to both ends of the voice coil 4 via lead wires (not shown). It is configured as a conductive type, cone type speaker unit classified according to the shape of the diaphragm 6, and full range type (single cone type) speaker unit classified according to the reproduction band.

The magnetic circuit 2 includes a disk-shaped bottom plate 20 having a cylindrical center pole 20a, an annular magnet 21 placed on the bottom plate 20, and laminated on the bottom plate 20 with the magnet 21 interposed therebetween. The integrated annular top plate 22 forms an external magnet type, and a constant width annular magnetic gap 2a is formed between the outer peripheral surface of the center pole 20a and the inner peripheral surface of the top plate 22. forming.

When a voice signal is input from the outside to the voice coil 4 arranged in the magnetic gap 2a and current flows through the voice coil 4, the voice coil 4 vibrates in the vertical direction in the axial direction based on Fleming's left-hand rule. . Then, the vibration of the voice coil 4 is transmitted to the diaphragm 6 by the bobbin 5, and the diaphragm 6 also vibrates in the vertical direction. Then, the air around the diaphragm 6 vibrates, and sound waves are radiated.

As shown in FIGS. 3, 4A, and 5A, the diaphragm 6 is formed by hot-press molding a sheet-like (thin plate-like) base material. In this embodiment, a synthetic resin sheet such as a polyimide sheet having a thickness of 0.5 μm is used as the base material. In addition, sheets (thin plates) of paper, cloth, PEN, PET, PP, PEI, PEEK, aluminum, titanium, magnesium, etc. may be used.

Diaphragm 6 has a joint angle with voice coil 5, that is, a half apex angle θ of more than 45°, and is formed in a shallow shape with a low overall height.

The diaphragm 6 is obtained by integrally forming a cone-shaped diaphragm body 60 and a roll-shaped edge 61 .

A center hole 60 a and a cylindrical voice coil 4 joint portion 60 b surrounding the center hole 60 a are formed in the central portion of the diaphragm main body 60 . is adhesively fixed to the upper outer peripheral surface of the . In this embodiment, the angle of the diaphragm main body 60 at the joint portion between the diaphragm main body 60 and the bobbin 5 is the half apex angle θ of the diaphragm 6, which is 60° exceeding 45°.

The diaphragm main body 60 is provided with reinforcing ribs 60c that spread radially and gradually decrease in height from the center to the outer periphery of the diaphragm main body 60. The rigidity of the diaphragm body 60 is increased, and the rigidity of the diaphragm body 60 is gradually lowered from the center of the diaphragm body 60 toward the outer periphery.

A plurality of auxiliary ribs 60c are formed at regular intervals in the circumferential direction of the diaphragm main body 60. As shown in FIG. In this embodiment, 18 are formed at intervals of 20° in the circumferential direction of the diaphragm main body 60 .

Since the diaphragm 6 is formed by hot-pressing a sheet-like base material, the auxiliary ribs 60c are formed on the surface (upper surface) of the diaphragm body 60 on the sound radiation side and on the opposite side of the sound radiation side. One of the back surfaces (lower surfaces) of the is convex and the other is concave. In this embodiment, the rear surface of the diaphragm body 60 is convex and the front surface is concave. The cross-sectional shape of the auxiliary rib 60c is formed in a U-shape with an upward opening.

The reinforcing ribs 60c gradually decrease in height from the center to the outer periphery of the diaphragm main body 60 and disappear at the outer periphery of the diaphragm main body 60. Do not add unevenness to the surface.

Reinforcing ribs 60c, which are convex on one side and concave on the other of the front and back surfaces of diaphragm body 60, connect to joint 60b with voice coil 4 at the center of diaphragm body 60, and the diaphragm Since the rigidity of the central portion of the main body portion 60 is low, the reinforcing rib 60c is spaced apart from the joint portion 60b of the central portion of the diaphragm main body portion 60 and the voice coil 4 . It is preferable to make the separation distance as small as possible within a range in which there is no problem in molding the diaphragm 6 .

The edge portion 61 has an edge body portion 61a having a downward convex semicircular cross-sectional shape, and a joining portion 61b with the frame 3 having a flat cross-sectional shape. The edge body 61 a surrounds the outer periphery of the diaphragm body 60 , and the inner periphery of the edge body 61 a is connected to the outer periphery of the diaphragm body 60 . The joint portion 61b with the frame 3 surrounds the outer peripheral portion of the edge body portion 61a, and the inner circumference of the joint portion 61b with the frame 3 is connected to the outer periphery of the edge body portion 61a. The joint portion 61 b with the frame 3 is fixed to the outer peripheral portion of the upper end of the frame 3 .

The edge portion 61 has an edge body portion 61a having a downwardly convex semicircular cross-sectional shape. overall height is reduced. That is, the height of the diaphragm 6 is reduced.

The edge portion 61 has a role of connecting the outer peripheral portion of the diaphragm main body 60 and the frame 3, always holds the diaphragm main body 60 in the correct position, and follows the movement of the diaphragm main body 60 without hindering it. do. The damper 8 has an inner peripheral portion that is adhesively fixed to the outer periphery between the voice coil 5 and the joint portion of the bobbin 5 with the diaphragm body 60 , and an outer peripheral portion of the damper 8 that is attached to the inner portion of the frame 3 . It is adhesively fixed to the bottom surface with an adhesive, has a role of connecting the voice coil 4 and the frame 3, always holds the voice coil 4 in a correct position, and follows the movement of the voice coil 5 without hindering it. The voice coil 4, the bobbin 5, the diaphragm 6, the cap 7 and the damper 8 constitute the vibration system of the speaker 1, and the edge portion 61 and the damper 8 are springs of the vibration system.

As shown in FIGS. 3, 4B, and 5B, the cap 7 is formed by hot-pressing a sheet-like base material. In this embodiment, the same base material as the diaphragm 6 is used as the base material.

The cap 7 has a dome-shaped cap body portion 70 that is convex upward, and a joint portion 71 that is joined to a diaphragm body portion 60 that surrounds the outer circumference of the cap body portion 70 and has an annular shape with a constant width. The inner periphery of the joint portion 71 with the body portion 60 is connected to the outer periphery of the cap body portion 70, and the joint portion 71 with the diaphragm body portion 60 is located between the center portion and the outer periphery portion of the diaphragm body portion 60. It is adhered and fixed with an adhesive in a state of being superimposed on the surface of the diaphragm main body 60, and a joint portion 60b between the upper end opening of the bobbin 5, the center hole 60a of the diaphragm main body 60, and the voice coil 4 of the diaphragm main body 60. The central portion of the diaphragm body portion 60 including the and is covered with the cap body portion 70 .

The cap 7 has a second reinforcing rib 71a extending radially along the reinforcing rib 60c at the joint portion 71 with the diaphragm body portion 60, and the joint portion 71 with the diaphragm body portion 60 at the diaphragm body portion 60. are joined with the reinforcing rib 60c and the second reinforcing rib 71a overlapping each other, so that the rigidity of the joint portion 71 with the diaphragm body portion 60 is increased.

The second reinforcing ribs 71a are formed in the same number as the reinforcing ribs 60c at the same intervals as the reinforcing ribs 60c in the circumferential direction of the joint portion 71 with the diaphragm main body 60. The joining portion 71 can be joined with the reinforcing rib 60c and the second reinforcing rib 71a overlapping each other.

The cross-sectional shape of the second reinforcing rib 71a is formed in an upwardly-opened U-shape so as to overlap the reinforcing rib 60c in a state where the entire second reinforcing rib 71a is fitted inside the reinforcing rib 60c. The back surface of the joint portion 71 with the diaphragm main body portion 60 is made convex and the front surface is made concave.

The height of the second reinforcing rib 71a is set so that the entire second reinforcing rib 71a is fitted inside the reinforcing rib 60c and overlapped with the reinforcing rib 60c. It is gradually lowered from the inner peripheral portion toward the outer peripheral portion. The second reinforcing rib 71a disappears at the outer periphery of the joint portion 71 with the diaphragm main body portion 60, and neither the surface nor the rear surface of the outer periphery of the joint portion 71 with the diaphragm main body portion 60 is uneven. Therefore, the angle of the bottom side of the second reinforcing rib 71a is larger than the angle of the bottom side of the reinforcing rib 60c, and the bottom side of the second reinforcing rib 71a is the inner peripheral portion of the joint portion 71 with the diaphragm body portion 60. , the separation distance from the bottom of the reinforcing rib 60c gradually increases from the state of contact with the bottom of the reinforcing rib 60c toward the outer peripheral portion of the joint portion 71 with the diaphragm main body 60. As shown in FIG. The reinforcing rib 60c and the second reinforcing rib 71a are adhered and fixed by an adhesive filling the gap between the bottom side of the reinforcing rib 60c and the bottom side of the second reinforcing rib 71a.

FIG. 6 shows the frequency characteristics of the speaker 1 of this embodiment and the speaker of the comparative example. The speaker of the comparative example has the same structure as the speaker 1 of the present embodiment except for using a diaphragm that does not form the reinforcing ribs 60 and a cap that does not form the second reinforcing ribs 71a. . In the speaker of the comparative example, as shown by characteristic B in FIG. 6, the sound pressure sharply drops below 8 kHz.

On the other hand, the speaker 1 of this embodiment maintains the sound pressure up to 20 kHz, as indicated by characteristic A in FIG.

As described above, according to the speaker 1 of the present embodiment, the diaphragm 6 has the cone-shaped diaphragm main body 60, spreads radially in the diaphragm main body 60, and spreads from the center of the diaphragm main body 60. By forming the reinforcing ribs 60c whose height gradually decreases toward the outer peripheral portion, the rigidity of the central portion of the diaphragm 6 is high even with the shallow diaphragm 6, so that the high-range reproduction limit frequency is reduced to that of the deep diaphragm. It will be as high as the diaphragm. In addition, since the rigidity of the diaphragm 6 gradually decreases from the center to the outer periphery of the diaphragm 6, as the frequency increases, split vibration gradually occurs from the outer periphery of the diaphragm 6, thereby causing edge rebound. Abrupt peak dips such as resonance can be reduced. As a result, it is possible to widen the reproduction frequency band of the speaker 1 while reducing the thickness of the speaker 1 by using the shallow diaphragm 6 . Here, in the case of the diaphragm 6 formed by hot-press molding a sheet-like base material, the opposite side of the convex surface of the reinforcing rib 60c is concave. , the rigidity of the central portion of the diaphragm 6 formed by heat-press molding a sheet-like base material can be increased. Therefore, by using a shallow diaphragm 6 made by heat-pressing a sheet-like base material, it is possible to widen the reproduction frequency band of the speaker 1 while reducing the thickness of the speaker 1. .

In addition, the diaphragm 6 includes a cap 7 that covers the central portion of the diaphragm main body 60 , the cap 7 has a dome-shaped cap main body 70 , and the diaphragm main body 60 and the diaphragm main body 60 are provided on the outer circumference of the cap main body 70 . and second reinforcing ribs 71a extending radially along the reinforcing ribs 60a are formed in the joint portion 71 with the diaphragm main body 60. By joining the joint 71 with the reinforcing rib 60c and the second reinforcing rib 71a in an overlapping state, the rigidity of the joint 71 with the diaphragm main body 60 is increased. The reproduction limit frequency can be increased, and the reproduction frequency band of the speaker 1 can be widened.

1 speaker 6 diaphragm 7 cap 60 diaphragm body 60c reinforcement rib 70 cap body 71 junction with diaphragm body 71a second reinforcement rib

Claims (3)

A cone-shaped diaphragm main body made of a sheet-like base material is provided, and one of the surface of the diaphragm main body on the sound radiation side and the back surface on the side opposite to the sound radiation side of the diaphragm main body is convex. and forming a reinforcing rib having a concave surface on the other side, the reinforcing rib spreading radially in the diaphragm main body, and gradually decreasing in height from the center to the outer peripheral part of the diaphragm main body, A diaphragm for a speaker spaced apart from a joint with a voice coil at the center of the diaphragm main body,
A cap covering a central portion of the diaphragm main body is provided, the cap has a dome-shaped cap main body, and a joint portion with the diaphragm main body is formed on an outer periphery of the cap main body, A second reinforcing rib extending radially along the reinforcing rib is formed at the joint portion with the diaphragm main body portion, and the joint portion with the diaphragm main body portion is formed at the joint portion with the diaphragm main body portion with the reinforcing rib. A diaphragm for a speaker, characterized in that it is joined to a second reinforcing rib in an overlapping state . A speaker comprising the speaker diaphragm according to claim 1 . An electronic device comprising the speaker according to claim 2 .

Images