JP2016208287A - Speaker - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a speaker in which acoustic performance is hardly deteriorated even if the space on the front face of the diaphragm is not hermetically sealed, and sufficient strength against external stress is obtained.SOLUTION: An electrodynamic speaker 1 has a diaphragm 2, a voice coil 3, a magnetic circuit 4, a frame 5, and a cover 7 arranged on the front surface side of the diaphragm 2, and in which a soldering terminal attached to the frame 5 is attached to a circuit substrate 12. First ventilation holes communicating a first internal space 8 formed by the frame and the diaphragm with the outside are provided in the frame, and second ventilation holes 11 communicating a second internal space 10 formed between the cover and the diaphragm with the outside are provided in the cover. The ventilation pipes 9 that extend the first ventilation holes to the back of the speaker are formed in a protruding manner from the back surface of the frame, and the ventilation pipes are inserted into the through holes provided in the substrate. The sound wave radiated from the surface side of the diaphragm is released to the outside through the ventilation holes and the sound wave radiated from the back surface side of the diaphragm is released to the outside from the back surface 12b side of the circuit board via the ventilation pipes.SELECTED DRAWING: Figure 4

Description

  The present invention relates to an electrodynamic speaker attached to a circuit board.

  For example, it is mounted on the surface of the circuit board located behind the pointer-type display means and liquid crystal-type display means mounted on a vehicle meter, and is small and thin to emit an alarm sound when the driver is not wearing a seat belt. In recent years, liquid crystal screens for vehicle instruments have become larger and the number of parts has increased, so there is not enough room for speakers on the vehicle instrument or instrument panel side. In many cases, the structure cannot be secured and the front surface of the speaker cannot be sealed.

  In such a situation, the speaker is small and thin, and when the narrow back space of the diaphragm is configured as a sealed space, the diaphragm receives acoustic resistance and the sound pressure is significantly reduced. Therefore, a ventilation hole that communicates the back space of the diaphragm with the outside is provided in the frame (see, for example, Patent Document 1). However, the ventilation hole is short and the distance from the front surface of the diaphragm is short. For this reason, there is a problem that the sound pressure is reduced because the sound tends to circulate and the circulated sound cancels out with the sound emitted from the front surface of the diaphragm.

  In addition, when the speaker is attached to the substrate, the terminal attached to the frame is fixed to the substrate by soldering (see, for example, Patent Document 1). However, when only reflow soldering is used, the strength is low against external stress. There was a problem.

JP 2011-18953 A

  It is an object of the present invention to provide a speaker that is attached to a circuit board and that is less susceptible to deterioration in acoustic performance and that has sufficient strength against external stress without sealing the space in front of the diaphragm. And

  In order to achieve the above-mentioned object, the present invention according to claim 1 is an electrodynamic speaker attached to a circuit board, comprising a diaphragm, a voice coil, a magnetic circuit, a frame, and the frame. The other end of the voice coil having a plurality of attached soldering terminals, the magnetic circuit being coupled to the frame on the back side of the diaphragm, and one end inserted into a magnetic gap of the magnetic circuit In the speaker in which the diaphragm is coupled to a portion, an outer peripheral portion of the diaphragm is supported and fixed to the frame, and an internal space is formed between the diaphragm and the frame, the frame is attached to the frame. In a state where a plurality of ventilation pipes communicating with the outside of the internal space on the back side are projected toward the rear of the speaker, and the plurality of ventilation pipes are inserted into a plurality of through holes provided in advance in the circuit board, It is characterized in that attached to the serial circuit board.

  The invention according to claim 2 is characterized in that the plurality of terminals for soldering attached to the frame according to claim 1 are of a surface mount type. According to a third aspect of the present invention, in addition to the configuration according to the first or second aspect, an outer peripheral portion of the cover is coupled to the frame so as to cover the diaphragm on the front side of the diaphragm. The cover is provided with a vent hole that communicates an internal space formed between the diaphragm and the cover to the outside.

  The invention described in claim 4 is characterized in that the speaker described in claims 1 to 3 is a vehicle speaker as an auditory information providing means.

According to the present invention, on the back side of the diaphragm, the sound is radiated from the plurality of vent pipe openings, and the distance between the vent pipe opening and the diaphragm front surface does not protrude from the frame. The sound is radiated from the back side of the circuit board through a plurality of vent pipe openings on the back side of the diaphragm, and the circuit board is interposed between the vent pipe opening and the front side of the diaphragm. Therefore, sound wraparound can be reduced.
Further, the plurality of vent pipes are positioned with respect to the circuit board, and the strength is increased against external stress in the surface direction of the circuit board.
Therefore, it is possible to provide a speaker that is attached to a circuit board and that is less susceptible to deterioration in acoustic performance and that has sufficient strength against external stress without sealing the space in front of the diaphragm.

It is the perspective view which looked at the speaker which shows one embodiment of this invention from the back side. It is AA sectional drawing of FIG. It is a side view which shows the state which attached the speaker to the circuit board. It is sectional drawing equivalent to FIG. 2 which shows the state which attached the speaker to the circuit board. It is the perspective view which looked at the speaker of the comparative example from the back side. It is a sectional side view explaining the effect | action of the speaker which concerns on embodiment of this invention, comparing with the speaker of a comparative example.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a perspective view of a speaker according to an embodiment of the present invention as viewed from the back side, and FIG. 2 is a cross-sectional view taken along line AA in FIG. According to the figure, the speaker 1 is a small and thin electrodynamic type, and includes a diaphragm 2, a voice coil 3, a magnetic circuit 4, a frame 5, and a plurality of soldering terminals 6 attached to the frame 5. And a cover 7.

  On the back side (back side) of the diaphragm 2 (the lower side of the drawing in FIG. 2), the magnetic circuit 4 is coupled to the frame 5, and one end (lower end) is inserted into the magnetic gap G of the magnetic circuit 4. The other end (upper end) of the diaphragm 2 is coupled, the outer periphery of the diaphragm 2 is supported and fixed to the frame 5, and a first internal space 8 is formed between the diaphragm 2 and the frame 5. A plurality of ventilation pipes 9 communicating with the outside of the first internal space 8 on the back side of the diaphragm 2 are formed to protrude from the frame 5 toward the rear of the speaker 1.

  On the front side (front side) of the diaphragm 2 (upper side in FIG. 2), the edge of the cover 7 is coupled to the frame 5 so as to cover the diaphragm 2, and a second portion is provided between the diaphragm 2 and the cover 7. The inner space 10 is formed, and the cover 7 is provided with a vent hole 11 for communicating the second inner space 10 on the front side of the diaphragm 2 with the outside.

  FIG. 3 is a side view showing a state where the speaker is attached to the circuit board, and FIG. 4 is a cross-sectional view corresponding to FIG. 2 showing a state where the speaker is attached to the circuit board. According to the figure, the speaker 1 is attached to the surface 12a of the circuit board 12 located behind the pointer type display means and the liquid crystal type display means mounted on the vehicle meter, for example. The plurality of vent pipes 9 are respectively inserted into the through holes 13 and attached to the surface 12 a of the circuit board 12. Specifically, the speaker 1 is fixed and connected by soldering a plurality of terminals 6 to the surface 12 a of the circuit board 12. More specifically, the plurality of terminals 6 are of surface mount type, and are fixed and connected by reflow soldering to a plurality of pads (also referred to as lands) provided in advance on the circuit board 12 together with the plurality of through holes 13. . Note that the plurality of terminals 6 are of an insertion mounting type instead of a surface mounting type, and are inserted into a plurality of through holes provided in advance together with the plurality of through holes 13 in the circuit board 12, and the circuit is reflow soldered. The circuit board 12 may be fixed and connected to only the back surface 12b of the substrate 12 or to both surfaces 12a and 12b of the circuit substrate 12 by reflow soldering and reflow soldering.

  The components of the speaker 1 will be further described with reference to FIGS.

  The frame 5 is made of an insulating synthetic resin material, has a substantially square outer shape in a plan view, is provided with a circular opening 5a for mounting the magnetic circuit 4, and the lower surface of the frame 5 is the speaker 1 When the circuit board 12 is attached to the circuit board 12, a board facing surface 5b (back face of the speaker 1) facing the surface 12a of the circuit board 12 is formed. The substrate facing surface 5 b is formed so as to be positioned slightly below the lower surface of the magnetic circuit 4. A circular step surface concentric with the circular opening 5a is provided on the inner peripheral portion of the upper surface of the frame 5, and this circular step surface constitutes the diaphragm support portion 5c.

  On the back side of the diaphragm 2, the magnetic circuit 4 is coupled to the frame 5, and the diaphragm 2 is coupled to the other end of the voice coil 3 with one end inserted into the magnetic gap G of the magnetic circuit 4. The edge of the diaphragm 2 is supported and fixed to the frame 5, and an internal space 8 is formed between the diaphragm 2 and the frame 5. The diaphragm 2 is fixed to the frame 5 by adhering and fixing the rear surface of the outer peripheral portion of the diaphragm 2 to the diaphragm support portion 5c. By this fixing, the first internal space 8 is formed on the back side of the diaphragm 2.

  Terminals 6 are embedded in the corners of the four corners of the frame 5 by insert molding, and the four terminals 6 are integrally attached to the frame 5. Each terminal 6 is for surface mounting, and the substrate contact portion 6a of each terminal 6 is exposed substantially flush with the substrate facing surface 5b at the corners at the four corners of the substrate facing surface 5b. Two terminals 6 embedded in the two corner portions of the corner portions at the four corners of the frame 5 are exposed on the upper surfaces of the corner portions, and the exposed portions serve as connection portions with a pair of coil lead wires. .

  In the frame 5, the vent pipes 9 are formed at right angles from four positions between the four board contact portions 6 a exposed at the corners of the four corners of the board facing surface 5 b, and the four vent pipes 9 are integrated with the frame 5. Is formed. Each vent tube 9 is formed in a rectangular tube shape having a substantially rectangular cross-sectional shape in which the adjacent direction of the two substrate contact portions 6a sandwiching the vent tube 9 is the longitudinal direction, and the speaker 1 is attached to the surface 12a of the circuit board 12 In this case, the front end of the vent tube 9 has a length that slightly protrudes from the back surface 12 b of the circuit board 12, that is, a length that is slightly longer than the thickness of the circuit board 12. The surface located outside the frame 5 of each vent pipe 9 has a cross-sectional shape that is a middle-high and sub-arc shape, and each vent pipe 9 is aligned to the same length.

  The diaphragm 2 has a circular front surface 2a and a back surface 2b made of a metal film or a resin film, and the cross section of the diaphragm 2 forms a dome shape in which the central portion 14 swells to the front side, and around the central dome portion 14. And a peripheral edge 15 having a rectangular shape in plan view.

  FIG. 5 is a perspective view of a speaker having a conventional structure as viewed from the back side, and the members described in the above embodiment are denoted by the same reference numerals. In the speaker shown in FIG. 5, a communication hole 16 that communicates the internal space 8 formed between the diaphragm 2 and the frame 5 to the outside of the frame 5 opens in the substrate facing surface 5 b of the frame 5. The communication hole 16 opens into a notch groove 17 formed in the substrate facing surface 5b, and forms a sound wave leakage space with the surface 12a of the circuit board 12. The present embodiment is different from the present invention in that it does not have the vent pipe 9 protruding from the substrate opening surface of the frame 5.

FIG. 6 is a comparison between the embodiment of the present invention and the conventional form shown in FIG. 5. The left side of the center line shows the conventional structure, and the right side shows the structure of the present invention. Yes.
In the speaker 1 having the conventional structure shown in the left half of FIG. 6, the internal space 8 formed between the diaphragm 2 and the frame 5 is between the surface 12 a of the circuit board 12 and the board facing surface 5 b of the frame 5. Since the air leakage hole 16 is short and the distance from the front surface of the diaphragm 2 is short because the sound wave leakage space is released to the outside of the frame 5, the sound wraps around due to reflection on the surface of the circuit board 12. It is easy and the sound that wraps around interferes with the sound emitted from the front surface of the diaphragm 2 to cancel each other, so that the sound pressure is reduced.

On the other hand, in the speaker 1 to which the structure according to the present invention shown in the right half of FIG. 6 is applied, an internal space 8 formed between the diaphragm 2 and the frame 5 protrudes from the substrate facing surface 5b. It is discharged to the back side of the circuit board 12 through the vent tube 9. For this reason, since the sound wave emitted from the vent pipe 9 bypasses the outer periphery of the circuit board 12 and reaches the front surface of the speaker 1 due to the presence of the circuit board 12, the sound wave is attenuated during the period. Since the influence of the sound wave interference can be suppressed by the influence, the acoustic performance is hardly deteriorated as compared with the speaker having the conventional structure.
Furthermore, in the speaker 1 employing the technical idea of the present invention, the ventilation pipes 9 protruding from the board facing surface 5b of the frame 5 are inserted into the through holes 13 provided in the circuit board 12, respectively, so that the frame 5 is connected to the circuit. Since the positioning soldering is performed on the board 12, the frame 5 can be firmly connected and fixed to the circuit board 12.

  The present invention can be applied not only to a reflow type speaker but also to a pin terminal type speaker or a lead wire type speaker.

  DESCRIPTION OF SYMBOLS 1 ... Speaker, 2 ... Vibration plate, 3 ... Voice coil, 4 ... Magnetic circuit, 5 ... Frame, 5a ... Circular opening part, 5b ... Substrate facing surface, 5c ... Vibration plate support part, 6 ... Soldering terminal, 6a DESCRIPTION OF SYMBOLS ... Board | substrate contact part, 7 ... Cover, 8 ... 1st internal space, 9 ... Vent pipe, 10 ... 2nd internal space, 11 ... Vent hole, 12 ... Circuit board, 12a ... Surface of 2nd board | substrate, 12b ... Circuit Back surface of substrate, 13 through-hole, 14 central dome portion of vibration plate, 15 peripheral edge of diaphragm, 16 communication hole, 17 notch groove, G magnetic gap.

Claims (4)

An electrodynamic speaker attached to a board by soldering,
A diaphragm that radiates sound waves from both the front and back surfaces due to vibration,
A voice coil, a magnetic circuit and a frame disposed on the back side of the diaphragm;
A cover disposed on the surface side of the diaphragm;
A plurality of terminals for soldering attached to the frame;
Have
On the back side of the diaphragm, the magnetic circuit is coupled to the frame, the diaphragm is coupled to the other end of the voice coil with one end inserted into a magnetic gap of the magnetic circuit, and an edge of the diaphragm A portion is supported and fixed to the frame, and the frame is provided with a plurality of first ventilation holes that communicate with the outside a first internal space formed by the frame and the diaphragm,
On the surface side of the diaphragm, an edge of the cover is coupled to the frame, and a second internal space formed by the cover and the diaphragm is communicated with the cover. In a speaker provided with a vent hole,
The frame is formed with a plurality of vent pipes that project the plurality of first vent holes to the back of the speaker, and the plurality of vent pipes are formed in advance on the board when the speaker is attached to the board. Inserted into a plurality of through holes provided,
The sound waves radiated from the front surface side of the diaphragm radiate from the speaker mounting surface side of the substrate to the outside through the second ventilation hole, whereas the sound waves radiated from the back surface side of the diaphragm are a plurality of sound waves. A speaker configured to radiate to the outside from the back side of the substrate opposite to the speaker mounting surface side through the first vent hole and the vent pipe.   The speaker according to claim 1, wherein the plurality of terminals are provided with a soldering surface arranged in a plane parallel to the substrate, and are attached to the substrate by surface mounting.   On the front side of the diaphragm, an outer peripheral portion of the cover is coupled to the frame so as to cover the diaphragm, and a vent hole that communicates the internal space formed between the diaphragm and the cover to the outside. The speaker according to claim 1, wherein the speaker is provided on the cover.   The speaker according to any one of claims 1 to 3, wherein the speaker is a vehicle speaker as an auditory information providing unit.

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