Loudspeaker

Abstract

To provide a loudspeaker which is improved in heat dissipation efficiency with respect to heat generation of a voice coil.SOLUTION: A loudspeaker S1 comprises: a diaphragm 1; a voice coil 2 connected to the diaphragm 1; a magnetic circuit 3 having a magnetic gap 30 to which the voice coil 2 is inserted; and a frame 6 which supports the diaphragm 1 via an edge 4 and a damper 5 and to which the magnetic circuit 3 is attached. The damper 5 includes a thermo-conductive material, and has a voice coil contact part 52 and a magnetic circuit contact part 54. Then, heat generated in the voice coil 2 is transmitted to the magnetic circuit 3 and is dissipated from the magnetic circuit 3.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a dynamic speaker. [Background technology]

[0002] Conventionally, with regard to dynamic speakers, speakers with a cone-shaped diaphragm have been known in which the diaphragm and frame are significantly larger than the diameter of the voice coil, and a heat conduction path from the voice coil to the frame is formed by a voice coil bobbin made of a good thermal conductor and a damper with a good thermal conductor layer formed on one or both sides, so that heat generated by the voice coil is transferred to the frame and dissipated from the frame (see Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 51-150319 Summary of the Invention [Problem to be solved by the invention]

[0004] The above-mentioned conventional technology had the problem that in speakers with dome-shaped or flat diaphragms, the frame (heat dissipation area) was small compared to the heat generated by the voice coil, and many of them were made of resin, making it difficult to achieve sufficient heat dissipation.

[0005] SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a speaker with improved heat dissipation efficiency for heat generated by a voice coil. [Means for solving the problem]

[0006] A speaker according to the present invention comprises a diaphragm, a voice coil connected to the diaphragm, a magnetic circuit having a magnetic gap into which the voice coil is inserted, and a frame that supports the diaphragm via an edge and a damper and to which the magnetic circuit is attached; The damper is characterized by including a thermally conductive material and having a voice coil contact portion and a magnetic circuit contact portion.

[0007] In the speaker according to the present invention, it is preferable to add the following configurations (1) to (3) in order to improve the heat transfer from the damper to the magnetic circuit and further enhance the heat dissipation effect that lowers the temperature of the voice coil. (1) The damper has a thermally conductive layer formed on one or both sides. (2) The voice coil contact portion is arranged between the diaphragm and the voice coil and comes into contact with the voice coil, and the magnetic circuit contact portion has a magnetic circuit side contact portion that contacts the side of the magnet of the magnetic circuit arranged outside the voice coil or the side wall that is bent up from a yoke arranged at the bottom of the magnetic circuit, and a magnetic circuit bottom contact portion that contacts the underside of the yoke. (3) The magnetic circuit contact portion is fixed to the magnetic circuit with a thermally conductive double-sided tape. [Effects of the Invention]

[0008] According to the present invention, the damper contains a material with good thermal conductivity (e.g., a metal material with a thermal conductivity of 100 W / mk or more) and easily conducts heat. It also has a voice coil contact portion and a magnetic circuit contact portion, forming a heat conduction path from the voice coil to the magnetic circuit, allowing heat generated in the voice coil to be transferred to the magnetic circuit and then dissipated from the magnetic circuit. This ensures a larger heat dissipation area than the frame. Furthermore, the magnetic circuit can ensure a larger damper contact area than the frame, allowing heat generated in the voice coil to be efficiently transferred to the magnetic circuit. As a result, a speaker with improved heat dissipation efficiency for heat generated by the voice coil can be provided. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a cross-sectional view of a speaker according to an embodiment of the present invention. [Figure 2] 2 is a perspective view showing the speaker of FIG. 1 in an assembled state, seen obliquely from below. [Figure 3] FIG. 2 is an exploded perspective view of the speaker of FIG. 1. [Figure 4] FIG. 2 is a plan view showing a damper of the speaker of FIG. [Figure 5] FIG. 5 is a cross-sectional view taken along line AA in FIG. 4. [Figure 6] FIG. 10 is a cross-sectional view of a speaker according to another embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0010] A speaker S1 according to one embodiment of the present invention will be described below with reference to FIGS.

[0011] As shown in Figures 1 to 3, speaker S1 is mounted on small electronic devices such as smartphones, laptops, tablets, and digital cameras, and is a dynamic speaker comprising a diaphragm 1, a voice coil 2 connected to the diaphragm 1, a magnetic circuit 3 having a magnetic gap 30 into which the voice coil 2 is inserted, and a frame 6 on which the diaphragm 1 is supported via an edge 4 and a damper 5 and to which the magnetic circuit 3 is attached.When an audio current is passed through the voice coil 2, the voice coil 2 vibrates and the diaphragm 1 vibrates, emitting sound.

[0012] In the following, the side of the diaphragm 1 seen from the voice coil 2 (left side of the paper in Figure 1) is defined as the top, and the opposite side (right side of the paper in Figure 1) is defined as the bottom, and the stacking direction of the voice coil 2 and diaphragm 1 (i.e., the vibration direction of the voice coil 2 and diaphragm 1) is described as the up-down direction (left-right direction of the paper in Figure 1, up-down direction of the paper in Figure 3).

[0013] The diaphragm 1 has a rectangular plate-shaped vibration surface portion 11 made of a resin film, a rectangular ring-shaped edge 4 arranged around the vibration surface portion 11, and a rectangular ring-shaped outer frame portion 12 arranged around the edge 4.

[0014] The frame 6 is molded from a resin material and formed into a rectangular, short cylindrical shape with its axis extending vertically, and has two pairs of opposing side walls. The diaphragm 1 has a peripheral frame portion 12 fixed to the upper end of the frame 6, and a vibrating surface portion 11 supported via an edge 4 at the opening in the upper surface of the frame 6 so as to be able to vibrate vertically. The peripheral frame portion 12 is adhesively fixed to the upper ends of one pair of opposing cylindrical walls of the frame 6 located on the second magnet 33, 33 side as viewed from the first magnet 32, by adhesively fixing the upper surfaces of the base pieces 51 a, 51 a of the damper 5 via the base pieces 51 a, 51 a. The frame 6 is directly adhesively fixed to the upper ends of the other pair of opposing cylindrical walls of the frame 6.

[0015] The edge 4 is a fixed edge made of an extension of the material of the vibration surface portion 11. The edge 4 can also be a free edge made of a material different from that of the vibration surface portion 11 and fixed to the periphery of the vibration surface portion 11. The edge 4 is an up-roll edge that is convex upward.

[0016] The peripheral frame portion 12 is an extension of the edge 4 .

[0017] The diaphragm 1 is a planar type with a flat vibration surface portion 11. The diaphragm 1 may also be a dome type with the vibration surface portion 11 being convex upward.

[0018] The voice coil 2 is an air-core coil formed by winding a conductive wire into a rectangular short cylinder shape with its axis extending in the vertical direction. The voice coil 2 is connected and fixed to the underside of the vibrating surface 11 via the voice coil contact portion 52 of the damper 5, and hangs down from the voice coil contact portion 52 to the inside of the frame 6.

[0019] The magnetic circuit 3 has a rectangular plate-shaped yoke 31 fixed to the opening on the underside of the frame 6, a rectangular plate-shaped first magnet 32 ​​placed and fixed in the center of the upper surface of the yoke 31, a pair of rectangular plate-shaped second magnets 33, 33 placed and fixed on the upper surface of the yoke 31 outside a pair of opposite sides of the first magnet 32, a rectangular plate-shaped first pole piece 34 placed and fixed on the upper surface of the first magnet 32, and a pair of rectangular plate-shaped second pole pieces 35, 35 fixed on the upper surfaces of the second magnets 33, 33, forming a magnetic gap 30 between the first pole piece 34 and the second pole pieces 35, 35 into which a pair of opposing cylindrical wall portions of the voice coil 2 are inserted and positioned.

[0020] The yoke 31 has a pair of yoke side walls 31a, 31a that are bent up from a pair of opposing sides that are parallel to another pair of opposing sides of the first magnet 32. The yoke 31, the first pole piece 34, and the second pole pieces 35, 35 are made of a metallic magnetic material (magnetic body). The first magnet 32 ​​and the second magnets 33, 33 are permanent magnets.

[0021] The damper 5 holds the voice coil 2 and diaphragm 1 (i.e., the vibration system of the speaker S1), which vibrate in the vertical direction, in the correct position, and also plays a role in suppressing abnormal vibrations together with the edge 4. The damper 5 also forms a heat conduction path 50 from the voice coil 2 to the magnetic circuit 3.

[0022] 1 to 5, the damper 5 has a base 51 supported by the frame 6, a voice coil contact portion 52 that is a voice coil support portion, and a support arm portion 53 that supports the voice coil contact portion 52 on the base 51. The base 51, the voice coil contact portion 52, and the support arm portion 53 are on the same plane.

[0023] The base 51 is composed of a pair of rectangular plate-shaped base pieces 51a, 51a. The base pieces 51a, 51a are fixed to the upper ends of a pair of opposing cylindrical walls of the frame 6 on the second magnet 33, 33 side when viewed from the first magnet 32.

[0024] The voice coil contact portion 52 is formed in a rectangular plate shape and is disposed between the base pieces 51 a, 51 a. The voice coil contact portion 52 is adhesively fixed to the lower surface of the vibrating surface portion 11, and the upper end of the voice coil 2 is adhesively fixed to the lower surface of the voice coil contact portion 52. The voice coil contact portion 52 is disposed between the vibrating surface portion 11 and the voice coil 2.

[0025] The support arm portion 53 is configured as a pair disposed between the base pieces 51a, 51a and the voice coil contact portion 52. Each of the support arm portions 53, 53 is configured as a pair of crank-shaped support arm pieces 53a, 53a, one end of which extends from near the center of a pair of opposing sides of the voice coil contact portion 52 and the other end of which is connected to the inner edge end of the base pieces 51a, 51a.

[0026] The damper 5 has a base 51 fixed to the upper end of the frame 6, and a support arm 53 supporting the voice coil 2 and the vibration surface 11 via a voice coil contact portion 52 so that they can vibrate together in the vertical direction. The support arm pieces 53a, 53a are extendable and contractible, with the intermediate piece between one end piece and the other end piece formed in a wavy, meandering shape.

[0027] The damper 5 also has a magnetic circuit contact portion 54. The magnetic circuit contact portion 54 extends from the base portion 51 and is fixed to the magnetic circuit 3.

[0028] The damper 5 contains a metal material (an example of a thermally conductive material) such as aluminum having a thermal conductivity of 100 W / mk or more, and has a voice coil contact portion 52 and a magnetic circuit contact portion 54, forming a heat conduction path 50 from the voice coil 2 to the magnetic circuit 3.

[0029] The damper 5 has a thermally conductive layer 5b formed on the surface of a damper substrate 5a made of a resin film (see FIG. 5). The thermally conductive layer 5b is formed on both sides of the damper substrate 5a, but may be formed on only one side of the damper substrate 5a, including the lower surface, which is the voice coil contact surface of the voice coil contact portion 52, and the inner surface, which is the magnetic circuit contact surface of the magnetic circuit contact portion 54. The thermally conductive layer 5b can be formed by vapor-depositing a metal such as aluminum with a thermal conductivity of 100 W / mK or higher onto the damper substrate 5a. Alternatively, it can be formed by attaching a metal foil, such as aluminum, with a thermal conductivity of 100 W / mK or higher.

[0030] The magnetic circuit contact portion 54 has magnetic circuit side contact portions 54a, 54a that contact the outer surfaces of the second magnets 33, 33 arranged outside the magnetic gap 30, and a magnetic circuit bottom contact portion 54b that contacts the lower surface of the yoke 31.

[0031] The magnetic circuit side contact portions 54a are rectangular plate-shaped portions that are bent downward from the outer edges of the base pieces 51a, 51a, and are configured as a pair, with the inner surfaces of the magnetic circuit side contact portions 54a, 54a adhesively fixed to the outer surfaces of the second magnets 33, 33.

[0032] The magnetic circuit bottom contact portions 54b are rectangular plate-shaped portions that are bent inward from the lower ends of the magnetic circuit side contact portions 54a, 54a, and are configured as a pair, with the inner surfaces (upper surfaces) of the magnetic circuit bottom contact portions 54b, 54b being adhesively fixed to the lower surface of the yoke 31.

[0033] The magnetic circuit contact portion 54 is bonded to the magnetic circuit 3 with thermally conductive double-sided tape (not shown). Specifically, the inner surfaces of the magnetic circuit side contact portions 54a and 54a are bonded to the outer surfaces of the second magnets 33 and 33 with thermally conductive double-sided tape, and the inner surfaces of the magnetic circuit bottom contact portions 54b and 54b are bonded to the underside of the yoke 31 with thermally conductive double-sided tape. For this bonding, a thermally conductive adhesive containing aluminum or other metal powder with a thermal conductivity of 100 W / mk or higher can be used. Furthermore, thermally conductive double-sided tape or a thermally conductive adhesive can also be used to bond the voice coil contact portion 52 to the voice coil 2, the voice coil contact portion 52 to the vibrating surface portion 11, the base pieces 51a and 51a to the frame 6, and the base pieces 51a and 51a to the outer peripheral frame portion 12.

[0034] The present invention is not limited to the present embodiment, and various modifications are possible within the scope of the present invention. For example, the speaker S1 of the present embodiment includes a magnetic circuit 3 having magnets 32, 33, 33 on the inside and outside of the magnetic gap 30, but it may also include a well-known external magnet type magnetic circuit that has a magnet only on the outside of the magnetic gap 30.

[0035] In the speaker S1 of this embodiment, the damper 5 has magnetic circuit side surface contact portions 54a that contact the side surfaces of the second magnets 33 that are arranged outside the magnetic gap 30. However, for example, the damper 5 may be rotated 90° around the axis of the voice coil 2, resulting in a speaker S2 as shown in Fig. 6 in which the damper 5 has magnetic circuit side surface contact portions 54a that contact the outer surfaces of the yoke side walls 31a that are arranged outside the magnetic gap 30. This speaker S2 may also be provided with a well-known internal magnet type magnetic circuit that has magnets only inside the magnetic gap 30. [Explanation of symbols]

[0036] S1 Speaker 1 diaphragm 2 voice coils 3 Magnetic Circuit 30 Magnetic Gap 31 York 31a Yoke side wall 33 Second Magnet 4. Edge 5 Damper 5b Good thermal conductor layer 52 Voice coil contact 54 Magnetic circuit contact part 54a Magnetic circuit side contact part 54b Magnetic circuit bottom contact part 6 frames

Claims

1. a diaphragm; a voice coil connected to the diaphragm; a magnetic circuit having a magnetic gap in which the voice coil is disposed; and a frame that supports the diaphragm via an edge and a damper and to which the magnetic circuit is attached; The speaker is characterized in that the damper contains a thermally conductive material and has a voice coil contact portion and a magnetic circuit contact portion.

2. 2. The speaker according to claim 1, wherein the damper has a thermally conductive layer formed on one or both sides thereof.

3. 2. The speaker according to claim 1, wherein the voice coil contact portion is disposed between the diaphragm and the voice coil and contacts the voice coil, and the magnetic circuit contact portion has a magnetic circuit side contact portion that contacts the side of a magnet disposed outside the magnetic gap or a side wall that is bent up from a yoke disposed at the bottom of the magnetic circuit, and a magnetic circuit bottom contact portion that contacts the underside of the yoke.

4. 2. The speaker according to claim 1, wherein the magnetic circuit contact portion is fixed to the magnetic circuit with a thermally conductive double-sided tape.

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