Speaker

Abstract

To prevent a connection point between a tinsel wire and a voice coil in a speaker from coming into contact with magnetic circuits.SOLUTION: The speaker 1 includes a frame 2, a diaphragm 3 supported by the frame 2, a cylindrical bobbin 4 connected to the diaphragm 3, a voice coil 5 wound around the bobbin 4, a tinsel wire 6 connected to the voice coil 5, and a magnetic circuit 7 in which a lower half of the bobbin 4 and the voice coil 5 are accommodated in a bottomed circumferential gap 75. In a natural state in which the voice coil 5 is not energized, the connection point 11 between the tinsel wire 6 and the voice coil 5 is disposed above the 72a of the top surface of the outer peripheral portion 72 of the yoke 70, and the length L1 between the connection point 11 and the 72a of the top surface of the outer peripheral portion 72 is designed to be larger than the length L3 between the 4b of the lower end portion of the bobbin 4 and the bottom plate 71 of the yoke 70 in the vibration direction of the diaphragm 3.SELECTED DRAWING: Figure 2

Description

[Technical Field]

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

[0002] An example of a conventional speaker has a structure in which a voice coil is wound around the lower half of a bobbin connected to a diaphragm, the voice coil and tinsel wire are soldered to the outer surface of the upper half of the bobbin, and the lower half of the bobbin and voice coil are housed in a floating state in the gap of the magnetic circuit (see Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2005-277615 Summary of the Invention [Problem to be solved by the invention]

[0004] In the conventional speakers described above, the diaphragm can be deformed excessively due to pressure, for example, when submerged in water, which can cause the connection point between the tinsel wire and the voice coil to come into contact with the magnetic circuit, causing a short circuit, or the connection between the tinsel wire and the voice coil to become disconnected.

[0005] Therefore, one example of a problem that the present invention aims to solve is to prevent the connection point between the tinsel wire and the voice coil in a speaker from coming into contact with the magnetic circuit. [Means for solving the problem]

[0006] The present invention is a speaker comprising a frame, a diaphragm supported by the frame, a cylindrical bobbin connected to the diaphragm, a voice coil wound around the bobbin, a tinsel wire connected to the voice coil, a bottom plate, a center, and an outer periphery forming a bottomed peripheral gap, the gap accommodating the lower half of the bobbin and the voice coil, wherein in a natural state where no current is applied to the voice coil, the connection point between the tinsel wire and the voice coil is positioned above the top surface of the outer periphery, and the distance between the connection point and the top surface of the outer periphery in the vibration direction of the diaphragm is greater than the distance between the lower end of the bobbin and the bottom plate. [Brief explanation of the drawings]

[0007] [Figure 1] 1 is a cross-sectional view of a speaker according to a first embodiment of the present invention in its natural state. [Figure 2] FIG. 2 is an enlarged view of a main part of the speaker shown in FIG. [Figure 3] 3 is a cross-sectional view showing a state in which the diaphragm of the speaker of FIG. 2 is excessively deformed. [Figure 4] FIG. 2 is a perspective view showing the bobbin of FIG. [Figure 5] FIG. 4 is a cross-sectional view of a speaker according to a second embodiment of the present invention in its natural state. [Figure 6] FIG. 6 is an enlarged view of a main part of the speaker shown in FIG. 5. DETAILED DESCRIPTION OF THE INVENTION

[0008] An embodiment of the present invention will be described below. A speaker according to this embodiment includes a frame, a diaphragm supported by the frame, a cylindrical bobbin connected to the diaphragm, a voice coil wound around the bobbin, a tinsel wire connected to the voice coil, and a magnetic circuit having a bottomed, peripheral gap formed by a bottom plate, a center portion, and an outer periphery, the gap accommodating the lower half of the bobbin and the voice coil. In a natural state where the voice coil is not energized, the connection point between the tinsel wire and the voice coil is located above the outer periphery top surface, and the distance between the connection point and the outer periphery top surface in the vibration direction of the diaphragm is greater than the distance between the lower end of the bobbin and the bottom plate. Therefore, even if the diaphragm is excessively deformed due to pressure, such as when submerged in water, the lower end of the bobbin comes into contact with the bottom plate, preventing the connection point between the tinsel wire and the voice coil from coming into contact with the outer periphery top surface. This prevents short circuits and disconnection between the tinsel wire and the voice coil.

[0009] Furthermore, it is preferable that the frame has a cover covering the top surface of the outer periphery. The cover reliably prevents the connection point between the tinsel wire and the voice coil from contacting the top surface of the outer periphery. Furthermore, when the cover is provided, it is preferable that, in a natural state where the voice coil is not energized, the connection point be located above the cover, and that the distance between the connection point and the cover in the vibration direction of the diaphragm be greater than the distance between the lower end of the bobbin and the bottom plate. By forming the frame in this manner, even if the diaphragm is excessively deformed due to pressure, such as when submerged in water, the lower end of the bobbin will come into contact with the bottom plate, preventing the connection point between the tinsel wire and the voice coil from contacting the cover. This prevents the tinsel wire and the voice coil from coming loose.

[0010] The speaker may also include a damper connected to a portion of the bobbin below the connection point. In this case, it is preferable that, in a natural state where the voice coil is not energized, the connection point between the damper and the bobbin is located above the cover, and the distance between the connection point and the cover in the vibration direction of the diaphragm is greater than the distance between the lower end of the bobbin and the bottom plate. By configuring the speaker in this manner, even if the diaphragm is excessively deformed due to pressure, such as when submerged in water, the lower end of the bobbin comes into contact with the bottom plate, preventing the connection point between the damper and the bobbin from coming into contact with the cover. This prevents the connection between the damper and the bobbin from coming loose.

[0011] The magnetic circuit may also include a yoke having the bottom plate and the outer periphery, and a magnet and top plate that form the center. In this case, even if the diaphragm is excessively deformed due to pressure, such as when submerged in water, the bottom end of the bobbin will contact the bottom plate of the yoke, preventing the connection point between the tinsel wire and the voice coil from contacting the top surface of the outer periphery of the yoke. This prevents short circuits and disconnection between the tinsel wire and the voice coil.

[0012] The bobbin may also be composed of a bobbin main material formed in a sheet shape and rolled into a cylindrical shape, and a strip material wound around the outer periphery of the bobbin main material. In this case, the joint of the bobbin main material is preferably such that both ends of the bobbin main material are adjacent but not in contact with each other, and a slit extending in the vibration direction of the diaphragm is present between these ends. This prevents the bobbin from buckling when the diaphragm is excessively deformed by pressure, such as when submerged in water, and the lower end of the bobbin comes into contact with the bottom plate. This ensures that the deformation of the diaphragm is uniform in the circumferential direction. [Example]

[0013] (First Example) Figures 1 to 3 show a speaker 1 according to a first embodiment of the present invention. Figures 1 and 2 show the speaker 1 in its natural state, while Figure 3 shows the speaker 1 in a state in which the diaphragm 3 of the speaker 1 has been excessively deformed due to pressure, such as when submerged in water. The natural state of the speaker 1 refers to a state in which no current is flowing through the voice coil 5 and the voice coil 5 is stationary.

[0014] Speaker 1 includes a frame 2, a diaphragm 3 supported by frame 2, a cylindrical bobbin 4 connected to diaphragm 3, a voice coil 5 wound around bobbin 4, a tinsel wire 6 connected to voice coil 5, and a magnetic circuit 7 that houses the lower half of bobbin 4 and voice coil 5 in a bottomed peripheral gap 75. The dashed-dotted line P in Fig. 1 indicates the center of speaker 1. Diaphragm 3 vibrates in the direction of dashed-dotted line P.

[0015] In this specification, the side of the diaphragm 3 in the direction of the dashed dotted line P of the speaker 1 is referred to as "upper," and the side of the magnetic circuit 7 in the direction of the dashed dotted line P is referred to as "lower." The terms "upper" and "lower" used here are for the convenience of explaining the speaker 1, and do not necessarily coincide with the actual up and down directions when the speaker 1 is in use.

[0016] Frame 2 is made of insulating synthetic resin and is disposed below diaphragm 3. Frame 2 has mounting portion 23 to which the outer periphery of diaphragm 3 is attached, and cover portion 27 that covers top surface 72a of yoke 70 of magnetic circuit 7. Frame 2 also has attached to it a connector (not shown) that connects an external audio current supply source to tinsel cord 6. Note that the material of frame 2 is not limited to insulating synthetic resin, and may be, for example, metal.

[0017] Diaphragm 3 is formed in a cone shape, with the edge and center cap integrated. The outer periphery (edge) of diaphragm 3 is fixed to mounting portion 23 of frame 2. A bobbin 4 is connected to the underside of the center of diaphragm 3.

[0018] As shown in FIG. 4 , the bobbin 4 is composed of a bobbin main material 41 formed in a sheet shape and rolled into a cylindrical shape, and a strip material 42 wound around the outer surface of the bobbin main material 41. The joint of the bobbin main material 41 is such that both ends 41a, 41b of the bobbin main material 41 are adjacent to each other but not in contact with each other, and a slit S extending in the vibration direction of the diaphragm 3 is present between these ends 41a, 41b. The upper end 4a of the bobbin 4 is connected to the underside of the center of the diaphragm 3. In this embodiment, the slit S is located on a center line symmetrical about two connection points 11 (described later), but this is not a limitation and the slit S may be located off the center line. Furthermore, the bobbin main material 41 is not limited to being formed in a sheet shape and rolled into a cylindrical shape; for example, it may be a paper tube or a resin tube cut to a predetermined length. The slit S may also be omitted.

[0019] The voice coil 5 is wound around the outer peripheral surface of the lower half of the bobbin 4. Both ends of the voice coil 5 are soldered to tinsel wires 6 on the outer peripheral surface of the upper half of the bobbin 4. The connection point between the voice coil 5 and the tinsel wires 6 is denoted by the reference numeral 11. The connection point 11 between one end of the voice coil 5 and one tinsel wire 6 and the connection point 11 between the other end of the voice coil 5 and the other tinsel wire 6 are formed at the same position in the height direction of the bobbin 4 but at different positions in the circumferential direction of the bobbin 4.

[0020] There are two tinsel wires 6. One end of each tinsel wire 6 is connected to the connector attached to the frame 2, and the other end is soldered to the voice coil 5 at a connection point 11.

[0021] The magnetic circuit 7 includes a yoke 70 made of a magnetic material, a disk-shaped magnet 73, and a disk-shaped top plate 74 made of a magnetic material.

[0022] The yoke 70 has a disk-shaped bottom plate 71 and a cylindrical outer peripheral portion 72 standing upright from the outer edge of the bottom plate 71, and is open to the diaphragm 3 side. The yoke 70 is fixed to the frame 2. Furthermore, a top surface 72a of the outer peripheral portion 72 of the yoke 70 is covered by a cover portion 27 of the frame 2. The magnet 73 is disposed inside the yoke 70 and overlaps the bottom plate 71. The top plate 74 is overlapped on top of the magnet 73. The top surface 72a of the outer peripheral portion 72 of the yoke 70 and the top surface of the top plate 74 are disposed at approximately the same height. The magnet 73 and the top plate 74 form the center of the magnetic circuit 7.

[0023] A bottomed peripheral gap 75 is formed between the outer peripheral surfaces of the magnet 73 and top plate 74 and the outer peripheral portion 72 of the yoke 70. The lower half of the bobbin 4 and the voice coil 5 are housed in this gap 75 in a floating state.

[0024] In the speaker 1 configured as described above, the voice coil 5 is supplied with an audio current, and an electromagnetic force is generated as a driving force, causing the voice coil 5, bobbin 4, and diaphragm 3 to vibrate in the direction of the dashed-dotted line P, thereby outputting sound. This speaker 1 is designed so that, when used in a normal environment, the lower end 4b of the bobbin 4 does not come into contact with the bottom plate 71 of the yoke 70. However, if a large pressure is applied, for example, due to being submerged in water, the diaphragm 3 may deform excessively toward the magnetic circuit 7, causing the lower end 4b of the bobbin 4 to come into contact with the bottom plate 71 of the yoke 70, as shown in FIG. 3 . The speaker 1 of this example is designed so that, even in such a case, the connection point 11 between the tinsel wire 6 and the voice coil 5 will not come into contact with the magnetic circuit 7, causing a short circuit, or the connection between the tinsel wire 6 and the voice coil 5 will not be disconnected.

[0025] Specifically, in a natural state where the voice coil 5 is not energized, the connection point 11 between the tinsel wire 6 and the voice coil 5 is located above the top surface 72a of the outer periphery 72 of the yoke 70, and the distance L1 between the connection point 11 and the top surface 72a of the outer periphery 72 in the vibration direction of the diaphragm 3 (the direction of the dashed dotted line P) is designed to be greater than the distance L3 between the lower end 4b of the bobbin 4 and the bottom plate 71 of the yoke 70 (see FIG. 2). Therefore, even if the diaphragm 3 is excessively deformed, the lower end 4b of the bobbin 4 comes into contact with the bottom plate 71, preventing the connection point 11 from coming into contact with the top surface 72a of the outer periphery 72. This prevents short circuits and disconnection between the tinsel wire 6 and the voice coil 5.

[0026] In this example, instead of adding a new part to the conventional product, the bobbin 4 is made longer than the conventional product so that the distance L1 is greater than the distance L3.

[0027] Furthermore, in this example, because cover portion 27 of frame 2 covers top surface 72a of outer periphery 72, it is possible to reliably prevent connection point 11 from coming into contact with top surface 72a of outer periphery 72. Although it is preferable that speaker 1 is provided with cover portion 27, even if cover portion 27 is not provided and top surface 72a of outer periphery 72 is exposed, by designing distance L1 to be greater than distance L3, it is possible to prevent connection point 11 from coming into contact with top surface 72a of outer periphery 72 even if diaphragm 3 is excessively deformed.

[0028] Furthermore, in the natural state where the voice coil 5 is not energized, the connection point 11 is positioned above the cover portion 27, and the distance L2 between the connection point 11 and the cover portion 27 in the vibration direction of the diaphragm 3 is designed to be greater than the distance L3 between the lower end portion 4b of the bobbin 4 and the bottom plate 71 (see FIG. 2). Therefore, even if the diaphragm 3 is excessively deformed, the lower end portion 4b of the bobbin 4 comes into contact with the bottom plate 71, preventing the connection point 11 from coming into contact with the cover portion 27. This prevents the connection between the tinsel wire 6 and the voice coil 5 from being disconnected.

[0029] The above-mentioned "distance L2" is the distance between the connection point 11 in its natural state and the point where the connection point 11 first hits the cover portion 27 when the diaphragm 3 is virtually moved toward the magnetic circuit 7 along the vibration direction (the direction of the dotted line P) (in reality, the lower end portion 4b of the bobbin 4 first contacts the bottom plate 71, so the connection point 11 does not hit the cover portion 27).

[0030] Furthermore, since the bobbin 4 of this embodiment may come into contact with the bottom plate 71, a structure that makes it less likely to buckle is employed. Specifically, the joints of the bobbin main material 41 are such that both ends 41a, 41b of the bobbin main material 41 are adjacent to each other but not in contact with each other, and a slit S extending in the vibration direction of the diaphragm 3 is present between these ends 41a, 41b. Conventional bobbins have a structure in which the slit between both ends of the bobbin main material extends obliquely relative to the vibration direction of the diaphragm to improve roundness. Such conventional bobbins buckle when their lower ends come into contact with the bottom plate, and the amount of displacement when the diaphragm deforms is not uniform between the portions with and without the slit. However, by adopting the above structure in this embodiment, buckling of the bobbin 4 when its lower end 4b comes into contact with the bottom plate 71 can be prevented. This ensures that the deformation of the diaphragm 3 is uniform in the circumferential direction, thereby minimizing the deformation of the diaphragm 3.

[0031] (Second Example) 5 and 6 show a speaker 101 according to a second embodiment of the present invention. Figures 5 and 6 show the natural state of the speaker 101. In Figures 5 and 6, the same components as those in the first embodiment described above are given the same reference numerals and their explanations will be omitted.

[0032] The speaker 101 comprises a frame 102, a diaphragm 3 supported by the frame 102, a cylindrical bobbin 4 connected to the diaphragm 3, a voice coil 5 wound around the bobbin 4, a tinsel wire 6 connected to the voice coil 5, a magnetic circuit 7 that houses the lower half of the bobbin 4 and the voice coil 5 in a bottomed peripheral gap 75, and a damper 8 connected to a portion of the bobbin 4 below the connection point 11 between the tinsel wire 6 and the voice coil 5.

[0033] Frame 102 is made of insulating synthetic resin and is disposed below diaphragm 3. Frame 102 has diaphragm mounting portion 123 to which the outer periphery of diaphragm 3 is attached, cover portion 127 that covers top surface 72a of yoke 70 of magnetic circuit 7, and damper mounting portion 128 to which the outer periphery of damper 8 is attached. Note that the material of frame 102 is not limited to insulating synthetic resin, and may be, for example, metal.

[0034] The damper 8 is made of a material in which woven fabric is impregnated with resin and is formed in an annular shape. The outer periphery of the damper 8 is fixed to the damper mounting portion 128 of the frame 102, and the inner periphery is bonded to the bobbin 4. The connection point between the damper 8 and the bobbin 4 is denoted by the reference numeral 12. The connection point 12 is formed in the middle of the bobbin 4 in the height direction. The connection point 12 is also formed below the connection point 11 on the bobbin 4 between the tinsel wire 6 and the voice coil 5. A wavy portion is formed between the inner and outer peripheries of the damper 8. Note that the damper 8 is not limited to being made of a material in which woven fabric is impregnated with resin, and may be made of, for example, a film sheet material, a thermoplastic resin, or a thermosetting resin.

[0035] In the speaker 101 of this example, in a natural state where no current is applied to the voice coil 5, the connection point 11 between the tinsel wire 6 and the voice coil 5 is located above the top surface 72a of the outer periphery 72 of the yoke 70, and the distance L11 between the connection point 11 and the top surface 72a of the outer periphery 72 in the vibration direction of the diaphragm 3 (the direction of the dashed-dotted line P) is designed to be greater than the distance L13 between the lower end 4b of the bobbin 4 and the bottom plate 71 of the yoke 70 (see FIG. 6). Therefore, even if the diaphragm 3 is excessively deformed due to pressure, such as when submerged in water, the lower end 4b of the bobbin 4 comes into contact with the bottom plate 71, preventing the connection point 11 from coming into contact with the top surface 72a of the outer periphery 72. This prevents short circuits and disconnection between the tinsel wire 6 and the voice coil 5.

[0036] Also in this example, since the cover portion 127 of the frame 102 covers the top surface 72a of the outer periphery 72, the connection point 11 can be reliably prevented from coming into contact with the top surface 72a of the outer periphery 72.

[0037] Furthermore, in a natural state where no current is applied to the voice coil 5, the connection point 11 is positioned above the cover portion 127, and the distance L12 between the connection point 11 and the cover portion 127 in the vibration direction of the diaphragm 3 is designed to be greater than the distance L13 between the lower end portion 4b of the bobbin 4 and the bottom plate 71 (see FIG. 6). Therefore, even if the diaphragm 3 is excessively deformed, the lower end portion 4b of the bobbin 4 comes into contact with the bottom plate 71, preventing the connection point 11 from coming into contact with the cover portion 127. This prevents the connection between the tinsel wire 6 and the voice coil 5 from being disconnected.

[0038] Furthermore, in a natural state where no current is applied to the voice coil 5, the connection point 12 between the damper 8 and the bobbin 4 is located above the cover portion 127, and the distance L14 between the connection point 12 and the cover portion 127 in the vibration direction of the diaphragm 3 is designed to be greater than the distance L13 between the lower end portion 4b of the bobbin 4 and the bottom plate 71 (see FIG. 6). Therefore, even if the diaphragm 3 is excessively deformed, the lower end portion 4b of the bobbin 4 comes into contact with the bottom plate 71, thereby preventing the connection point 12 between the damper 8 and the bobbin 4 from coming into contact with the cover portion 127. This prevents the connection between the damper 8 and the bobbin 4 from coming loose and the damper 8 from being damaged.

[0039] Furthermore, in the above-described embodiment, the magnetic circuit 7 is an internal magnetic circuit in which the magnet 73 and top plate 74 are arranged on the inside, but the magnetic circuit of the present invention may be an external magnetic circuit in which the magnet and top plate are arranged on the outside. In that case, the bottom plate of the yoke forms the "bottom plate" of the magnetic circuit, the center pole of the yoke forms the "center" of the magnetic circuit, and the magnet and top plate form the "outer periphery" of the magnetic circuit.

[0040] Although the embodiments of the present invention have been described in detail above with reference to the drawings, the specific configurations are not limited to these embodiments, and the present invention also includes design changes within the scope of the present invention. The examples shown in the above figures can be combined with each other as long as there are no particular contradictions or problems in their purpose, configuration, etc. Furthermore, the contents of each figure can each be an independent embodiment, and the embodiment of the present invention is not limited to a single embodiment obtained by combining the figures. [Explanation of symbols]

[0041] 1,101 speakers 2,102 frames 3 Vibration plate 4 bobbins 5 voice coil 6 Kinshi Line 7 Magnetic Circuit 8 Damper 11 Connection point between voice coil and tinsel wire 12 Damper and bobbin connection point 27,127 Cover 70 York 71 Bottom plate 72 Outer periphery 73 Magnet (center) 74 Top plate (center) 75 Gap

Claims

1. The frame and a diaphragm supported by the frame; a cylindrical bobbin connected to the diaphragm; a voice coil wound around the bobbin; a tinsel wire connected to the voice coil; a bottomed circumferential gap is formed by a bottom plate, a central portion, and an outer circumferential portion, and a magnetic circuit is provided in the gap, accommodating the lower half of the bobbin and the voice coil; In a natural state where no current is applied to the voice coil, the connection point between the tinsel wire and the voice coil is located above the top surface of the outer periphery, and the distance between the connection point and the top surface of the outer periphery in the vibration direction of the diaphragm is greater than the distance between the lower end of the bobbin and the bottom plate. A speaker characterized by:

2. the frame has a cover portion that covers the top surface of the outer periphery, In a natural state where no current is applied to the voice coil, the connection point is disposed above the cover portion, and the distance between the connection point and the cover portion in the vibration direction of the diaphragm is greater than the distance between the lower end of the bobbin and the bottom plate.

2. The speaker according to claim 1.

3. a damper connected to a portion of the bobbin below the connection point; In a natural state where no current is applied to the voice coil, a connection point between the damper and the bobbin is disposed above the cover portion, and the distance between the connection point and the cover portion in the vibration direction of the diaphragm is greater than the distance between the lower end of the bobbin and the bottom plate.

3. The speaker according to claim 2.

4. The magnetic circuit includes a yoke having the bottom plate and the outer periphery, and a magnet and a top plate that form the central portion.

2. The speaker according to claim 1.

5. The bobbin is composed of a bobbin main material formed in a sheet shape and rolled into a cylindrical shape, and a strip material wound around the outer circumferential surface of the bobbin main material, The joint of the bobbin main material is such that both ends of the bobbin main material are close to each other without contacting each other, and a slit extending in the vibration direction of the diaphragm exists between these both ends.

2. The speaker according to claim 1.

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