JP2017108307A - Speaker device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a speaker device capable of improving heat dissipation.SOLUTION: A speaker device 100 has a speaker 10 and a case 20. The speaker device 10 has a magnetic circuit including a yoke 1. The case 20 accommodates the speaker 10. The case 20 has an opening 20b2 in a bottom plate 20b1 located on the opposite side from a direction of sound radiation by the speaker 10, and the yoke 1 projects at least partially outward from the opening 20b2. The bottom plate 20b1 has a concave curved surface 20b3 formed of a curved surface which is hollowed most at an end on the side of the opening 20b2 and gradually decreases in hollowing degree from the yoke 1 in a direction crossing the direction of the sound radiation.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a speaker device in which a speaker is housed in a case.

  Vehicles with quiet running sounds such as hybrid cars and electric vehicles are widespread, and pedestrians may not notice the approach of the vehicles. Therefore, a predetermined sound for causing the pedestrian to notice the approach of the vehicle may be generated from the speaker of the speaker device mounted outside the vehicle.

  The speaker device is mounted in, for example, an engine room. In addition, although an electric vehicle is provided with a motor instead of an engine, the engine room includes a storage unit that stores the motor.

JP 2006-340015 A

  The engine room is at a high temperature exceeding 100 ° C. When the speaker device is used at a high temperature, the components constituting the speaker are liable to deteriorate and the reliability is lowered. Therefore, a speaker device used in a high temperature environment is required to improve heat dissipation.

  An object of this invention is to provide the speaker apparatus which can improve heat dissipation.

  The present invention includes a speaker having a magnetic circuit including a yoke, and a case for housing the speaker, in order to solve the above-described problems of the related art, and the case is opposite to the sound emission direction of the speaker. An opening is formed in the bottom plate, and at least a part of the yoke protrudes outward from the opening. The end of the opening side of the bottom plate is most depressed, and the release from the yoke. Provided is a speaker device characterized in that a concave curved surface formed by a curved surface whose degree of depression gradually decreases as it goes away in a direction intersecting the sound direction.

  According to the speaker device of the present invention, heat dissipation can be improved.

It is sectional drawing which shows the speaker apparatus of one Embodiment. It is a figure which shows roughly the simulation result of the fluid analysis for demonstrating the effect of the speaker apparatus of one Embodiment. It is a figure which shows roughly the simulation result of the fluid analysis of the comparative example 1. It is a figure which shows roughly the simulation result of the fluid analysis of the comparative example 2.

  Hereinafter, a speaker device according to an embodiment will be described with reference to the accompanying drawings. A speaker device 100 according to an embodiment shown in FIG. 1 houses a speaker 10 in a case 20. As an example, the speaker device 100 is used by being mounted in an engine room of a vehicle.

  In FIG. 1, a U-shaped yoke 1 has a circular bottom surface portion 1a and a side surface portion 1b that surrounds the periphery of the bottom surface portion 1a. The yoke 1 is made of a metal such as iron. A circular magnet 2 is fixed on the bottom portion 1 a, and a circular top plate 3 is fixed on the magnet 2. The top plate 3 is made of a metal such as iron.

  A gap of a predetermined distance is provided between the side surface portion 1 b of the yoke 1 and the magnet 2 and the top plate 3.

  A portion below the cylindrical voice coil bobbin 4B is inserted into the gap between the side surface portion 1b, the magnet 2 and the top plate 3. The voice coil bobbin 4B is made of, for example, a plastic resin and a glass material. The voice coil 4 which is a copper wire, for example, is wound around the lower portion of the voice coil bobbin 4B.

  In a state where no voice signal is supplied to the voice coil 4, the lower end portion of the voice coil bobbin 4 </ b> B faces the upper end portion of the magnet 2. The voice coil 4 is located between the side surface portion 1 b and the top plate 3 in a state where no voice signal is supplied to the voice coil 4.

  Near the upper end of the voice coil bobbin 4B, the inner peripheral end of the diaphragm 5 is fixed. The diaphragm 5 is formed of any one of paper, plastic resin, wood, metal, carbon fiber and the like. An inner peripheral side end portion of a damper 6 formed in a bellows shape is fixed to an intermediate portion of the voice coil bobbin 4B. The damper 6 is made of, for example, a plastic resin.

  The inner peripheral side end of the edge 7 is fixed to the outer peripheral side end of the diaphragm 5. The edge 7 is formed of, for example, a synthetic resin (rubber), a fiber material (cloth), or the like, and has a semicircular section. The outer peripheral side end portion of the edge 7 is fixed to a flat portion 8 a formed in the vicinity of the upper end portion of the metal frame 8. The flat portion 8a is formed in a flange shape so as to intersect (orthogonally) the sound emission direction in which sound is emitted from the diaphragm 5. The upper direction in FIG. 1 is the sound emission direction.

  The outer peripheral side end portion of the damper 6 is fixed to a flat portion 8 b formed at the lower end portion of the frame 8. The flat portion 8b is also formed in a flange shape so as to intersect (orthogonal) the sound emission direction of the speaker 10. Although not shown, a plurality of openings are formed in the intermediate portion 8c between the flat portions 8a and 8b of the frame 8 at predetermined intervals in the circumferential direction.

  A center cap 9 is fixed to the center of the diaphragm 5 and closes a circular opening formed at the center of the diaphragm 5. The center cap 9 is made of, for example, a plastic resin.

  The speaker 10 is configured as described above. When a voice signal is supplied to the voice coil 4, the voice coil bobbin 4B vibrates in the vertical direction in FIG. 1, and the diaphragm 5 vibrates with the vibration of the voice coil bobbin 4B. Thereby, the diaphragm 5 emits a sound corresponding to the supplied audio signal.

  In the speaker device 100 shown in FIG. 1, the speaker 10 is a so-called inner magnet type speaker. The speaker 10 may be an external magnet type speaker.

  The case 20 houses the speaker 10, and the speaker 10 and the case 20 constitute the speaker device 100. The case 20 includes an upper case 20a and a lower case 20b. The case 20 is made of, for example, a plastic resin. Although not shown, the case 20 has a plurality of openings.

  For example, the upper case 20a and the lower case 20b are formed in a square columnar shape, a cylindrical shape, or the like whose surface viewed from the sound emission direction side or the opposite side to the sound emission direction. The upper case 20a is formed with a circular opening 20a1 for allowing the diaphragm 5 to face the outside. The upper case 20a may include a top plate that protects the diaphragm 5 and has a plurality of openings formed so that sound from the speaker 10 is emitted.

  A protruding portion 20a2 that protrudes toward the lower end side of the speaker device 100 is formed at the end of the upper case 20a on the opening 20a1 side. The tip of the protrusion 20 a 2 is in contact with the outer peripheral side end of the edge 7 fixed to the flat portion 8 a of the frame 8. That is, the protruding portion 20a2 and the flat portion 8a sandwich the outer peripheral side end portion of the edge 7.

  At the center of the bottom plate 20b1 of the lower case 20b, an opening 20b2 is formed so that the magnetic circuit including the yoke 1 protrudes from the lower case 20b. Since the yoke 1 protrudes to the outside through the opening 20b2, the most part of the magnetic circuit of the speaker 10 is located outside the lower case 20b. Therefore, the speaker device 100 is excellent in heat dissipation.

  In the speaker device 100 shown in FIG. 1, the entire yoke 1 protrudes outside through the opening 20b2. Only part of the yoke 1 may protrude outward from the opening 20b2. However, it is preferable to protrude the yoke 1 as much as possible to the outside.

  The bottom plate 20b1 is recessed in a circumferential shape when viewed from the lower end side of the lower case 20b. The peripheral part of the opening 20b2 in the bottom plate 20b1 is a flat part 20b10 that is most depressed. The flat portion 20b10 is in contact with the lower surface of the flat portion 8b of the frame 8.

  The protruding portion 20a2 presses the flat portion 8a via the edge 7, and the flat portion 20b10 presses the flat portion 8b. Therefore, the upper case 20a and the lower case 20b hold the speaker 10 therebetween.

  The bottom plate 20b1 is formed by a curved surface that continuously decreases from the yoke 1 to the direction (radial direction) intersecting (orthogonal) with the sound emission direction, following the flat surface of the lower surface of the flat portion 20b10. A concave curved surface 20b3 is formed.

  The bottom plate 20b1 may not be provided with the flat portion 20b10 around the opening 20b2, but may be configured by a curved surface in which the degree of the depression gradually decreases as the distance from the yoke 1 increases from the end on the opening 20b2 side.

  In the speaker device 100 shown in FIG. 1, since the speaker 10 is an inner magnet type, the yoke 1 has a bottom surface portion 1a and a side surface portion 1b surrounding the bottom surface portion 1a. The bottom plate 20b1 is recessed so that the position in the direction along the sound emitting direction of the end portion on the opening 20b2 side of the concave curved surface 20b3 reaches the position in the direction along the sound emitting direction of the end portion on the sound emitting direction side of the side surface portion 1b. Yes.

  If comprised in this way, since the whole yoke 1 protrudes outside from opening 20b2, it is preferable at the point of heat dissipation.

  In the speaker device 100 shown in FIG. 1, the position in the direction along the sound emitting direction of the surface opposite to the sound emitting direction of the bottom surface portion 1a is the sound emitting direction of the end portion on the opposite side to the sound emitting direction of the bottom plate 20b1. The end portion 20b4 on the opposite side of the sound emission direction in the lower case 20b does not protrude outward from the lower case 20b. The position of the surface of the bottom surface portion 1a opposite to the sound emission direction may be positioned closer to the sound emission direction than the end portion of the bottom plate 20b1 opposite to the sound emission direction.

  If comprised in this way, since the thickness (distance of the direction along a sound emission direction) of the speaker apparatus 100 becomes the thickness of case 20, it is convenient at the point of handling.

  The concave curved surface 20b3 is preferably formed so that the depression starts from a position as close as possible to the side surface of the lower case 20b. That is, it is preferable to make the length of the concave curved surface 20b3 in the radial direction as long as possible.

  As an example, the speaker device 100 configured as described above is mounted in the engine room of a vehicle with the sound emission direction facing forward in the traveling direction of the vehicle. When a vehicle equipped with the speaker device 100 travels, wind flows from the upper direction to the lower direction in FIG.

  The effects of the speaker device 100 having the concave curved surface 20b3 will be described using FIGS. 2 to 4 in comparison with the speaker devices of Comparative Examples 1 and 2 having no concave curved surface 20b3.

  FIG. 2 partially and schematically shows the yoke 1 and the lower case 20b, and schematically shows a simulation result of fluid analysis when the wind flows in from the right direction of FIG.

  In FIG. 2, in order to facilitate understanding, the wind speed is roughly classified into three stages, that is, a level 3 where the wind speed is strong, a level 2 where the wind speed is weak, and a level 1 where the wind speed is very weak. The distribution is shown. The level 3 wind is indicated by a solid line, the level 2 wind is indicated by a one-dot chain line, and the level 1 wind is indicated by a broken line.

  As can be seen from FIG. 2, since the speaker device 100 has the concave curved surface 20b3, the wind flowing from the right direction to the left direction in FIG. 2 wraps around the concave curved surface 20b3 and the yoke 1 receives a lot of level 2 wind. ing.

  FIG. 3 schematically shows a fluid analysis simulation result of Comparative Example 1 using a lower case 20b 'having a flat bottom plate 20b1' instead of the bottom plate 20b1 having a concave curved surface 20b3. As can be seen from FIG. 3, the yoke 1 is hardly hit by the level 2 wind and is hit by the level 1 wind.

  FIG. 4 shows a fluid analysis of Comparative Example 2 using a lower case 20b ″ having a bottom plate 20b1 ″ formed with a uniform inclined plane instead of the bottom plate 20b1 having a concave curved surface 20b3. The simulation result is shown schematically. Comparative Example 2 corresponds to the speaker device described in Patent Document 1.

  As can be seen from FIG. 4, although the strength of the wind hitting the yoke 1 is improved as compared with the comparative example 1, it is much weaker than the speaker device 100 of FIG.

  In the speaker device 100 of the present embodiment, at least a part of the yoke 1 protrudes outside the case 20, and when the wind flows from the sound emission direction to the direction opposite to the sound emission direction, the yoke 1 is conventional. Stronger than that, and a lot of wind hits. Therefore, according to the speaker device 100 of the present embodiment, the heat dissipation can be improved.

  Even when the speaker device 100 is used at a high temperature such as an engine room of a vehicle, deterioration of components constituting the speaker 10 can be suppressed, and reliability can be improved.

  Moreover, since the input voltage can be increased due to the improvement in heat dissipation, sound can be generated at a higher volume. Since it is not necessary to increase the degree of heat resistance of the components constituting the speaker 10, it is possible to reduce the cost of the components.

  The present invention is not limited to the embodiment described above, and various modifications can be made without departing from the scope of the present invention. The application of the speaker device 100 of the present embodiment is not limited to a vehicle.

DESCRIPTION OF SYMBOLS 1 Yoke 1a Bottom face part 1b Side face part 10 Speaker 20 Case 20a Upper case 20b Lower case 20b1 Bottom plate 20b2 Opening 20b3 Concave surface

Claims (3)

A speaker having a magnetic circuit including a yoke;
A case for housing the speaker;
With
The case has an opening in a bottom plate located on a side opposite to a sound emitting direction by the speaker,
The yoke has at least a part protruding outside from the opening,
The bottom plate is formed with a concave curved surface formed by a curved surface in which the end portion on the opening side is most depressed and gradually decreases from the yoke in a direction intersecting the sound emitting direction. A speaker device characterized by that. The yoke has a bottom surface and a side surface surrounding the bottom surface;
The bottom plate is recessed such that a position in the direction along the sound emitting direction of an end portion on the opening side of the concave curved surface reaches an end portion on the sound emitting direction side of the side surface portion. Item 2. The speaker device according to Item 1.   The bottom surface portion has a position in a direction along the sound emission direction of a surface opposite to the sound emission direction, or the same position as the end portion of the bottom plate opposite to the sound emission direction or the sound emission direction side. The speaker device according to claim 2, wherein the speaker device is located at a position.

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