JP2013236197A - Electrodynamic sound emitting body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrodynamic sound emitting body suppressing leakage of sound from a drain hole with a simple structure, and reducing deterioration in frequency property.SOLUTION: An electrodynamic sound emitting body comprises: a magnetic circuit section including an outer yoke having a shape having a bottom part and a side wall part, and a magnet and an inner yoke arranged so as to be surrounded by the outer yoke; a coil arranged in a magnetic gap formed in the magnetic circuit section; a diaphragm to which the coil is fixed; a first elastic member elastically connecting between the diaphragm and the side wall part of the outer yoke; a case covering the outer yoke; and a second elastic member connecting between the periphery of the case and the periphery of the outer yoke without having a gap. The case, the diaphragm and the side wall outer surface of the outer yoke form an acoustic space. The electrodynamic sound emitting body has a drain tube having a space communicating with between the acoustic space and the outside of the case, and is formed integrally with the case.

Description

  The present invention relates to a sound generator for notifying a pedestrian around a vehicle or the presence of the vehicle to a pedestrian around the vehicle in a highly quiet electric vehicle such as a hybrid vehicle or an electric vehicle, and a back of a commercial vehicle such as a truck. The present invention relates to an electrodynamic sound emitting body used for an alarm device, a left / right turn voice guidance device, and the like.

  Electrodynamic sound emitting bodies (speakers) used for such alarm devices, alarm devices, voice guidance devices and the like are usually mounted outside the vehicle, and thus function sufficiently even when exposed to wind and rain. High reliability is desired to demonstrate. Especially when speakers must be installed in places such as bumpers before and after vehicles exposed to wind and rain, tire houses, engine rooms, etc., water resistance measures for the speakers are indispensable.

  Patent Document 1 describes a speaker in which an edge support portion is formed on the outer periphery of a frame provided behind a diaphragm that emits sound waves, and a drain hole penetrating the frame is formed behind the edge support portion. Yes. In the speaker described in Patent Document 1, water droplets that have entered the diaphragm back space reach a space surrounded by the frame and the edge member, but are then discharged to the outside of the speaker through a drain hole. Thus, the speaker described in Patent Document 1 eliminates the influence of water droplets on the diaphragm.

  Moreover, patent document 2 is disclosing the drain hole of the speaker unit installed in humid environments, such as the outdoors and a bathroom. In this speaker unit, a speaker opening is provided in a unit body having a water drain hole and a moisture drain hole, and the speaker is disposed in the unit body with the speaker facing the speaker opening. Further, a speaker sealing case that covers the speaker from the back is attached to the speaker holding member, and a substantially sealed region including the speaker isolated from the region including the water drain hole and the moisture drain hole is formed in the unit body.

  Incidentally, Patent Document 2 discloses a problem that the reverse phase sound emitted from the back surface of the speaker leaks from the drain hole and turns around the front surface of the speaker, so that the normal phase sound is canceled by the reverse phase sound and the sound quality is deteriorated. In order to solve the problem, it is disclosed that a speaker sealing case that covers the speaker from the back side is provided and isolated from a region including a water drain hole and a moisture drain hole.

Published Utility Model No. 3-79597 JP 2007-201669 A

  The speaker described in Patent Document 1 is simply provided with a hole at the bottom of the frame, and due to sound leakage from the hole, it interferes with the sound radiated forward, and the frequency characteristics of the entire speaker are low. There is a risk of deterioration. Moreover, in the speaker unit described in Patent Document 2, the speaker main body is separated from the region where the water drain hole and the moisture drain hole exist by covering the back surface of the speaker with a sealing case, thereby suppressing the deterioration of the frequency characteristics. However, a sealed case is necessary.

The present invention has been made in order to solve the above-described problems, and provides an electrodynamic sound emitting body that suppresses sound leakage from a drain hole with a simple configuration and has little deterioration in frequency characteristics. For the purpose.

  According to the present invention, an outer yoke having a shape having a bottom portion and a side wall portion, a magnetic circuit portion including a magnet and an inner yoke disposed between the outer yokes, and a magnetic gap formed in the magnetic circuit portion are disposed. A coil, a diaphragm to which the coil is fixed, a first elastic member that elastically connects the diaphragm and the side wall of the outer yoke, a case that covers the outer yoke, a case outer peripheral portion, and a diaphragm outer peripheral portion An electrodynamic sound emitting body having an acoustic space formed by a case, a diaphragm, and an outer surface of a side wall of the outer yoke, wherein the acoustic space and the outside of the case are connected to each other. A drain pipe having a communicating space and formed integrally with the case is provided.

  According to the present invention, an electrodynamic sound emitting body with a simple configuration provided with a drain pipe integrally formed with a case, which suppresses sound leakage from a water drain hole and has a low frequency characteristic deterioration can be obtained. .

It is side surface sectional drawing which shows the structure of the electrodynamic sound-emitting body by Embodiment 1 of this invention. It is sectional drawing in the AA position of FIG. 1 which shows the structure of the electrodynamic sound emission body by Embodiment 1 of this invention. It is sectional drawing which abbreviate | omits and partially shows the cross section in the BB position of FIG. 2 which shows the structure of the electrodynamic sound emission body by Embodiment 1 of this invention. It is sectional drawing which shows the case where the electrodynamic sound emission body by Embodiment 1 of this invention is inclined and arrange | positioned. It is sectional drawing which shows the case where the electrodynamic sound emitting body by Embodiment 1 of this invention is inclined and arrange | positioned at another angle. It is sectional drawing which shows the structure of the electrodynamic sound-emitting body by Embodiment 2 of this invention. It is sectional drawing which shows the case where the electrodynamic sound-emitting body by Embodiment 2 of this invention is inclined and arrange | positioned. It is sectional drawing which shows the case where the electrodynamic sound-emitting body by Embodiment 2 of this invention is inclined and arrange | positioned at another angle. It is sectional drawing which shows another structure of the electrodynamic sound-emitting body by Embodiment 2 of this invention. It is sectional drawing which shows the structure of the electrodynamic sound-emitting body by Embodiment 3 of this invention. It is sectional drawing which shows the structure of the electrodynamic sound-emitting body by Embodiment 4 of this invention.

Embodiment 1
FIG. 1 is a cross-sectional view showing a configuration of an electrodynamic sound emitting body according to Embodiment 1 of the present invention. In FIG. 1, one end magnetic pole side of a columnar magnet 2 is coaxially bonded to the outer yoke 1 on the inner bottom portion of an outer yoke 1 formed of a magnetic material and having a bottom and a cylindrical side wall. In addition, a cylindrical inner yoke 3 made of a magnetic material is bonded coaxially to the outer yoke 1 and the magnet 2 on the other end magnetic pole side of the magnet 2. The outer yoke 1, the magnet 2, and the inner yoke 3 constitute a magnetic circuit unit 100. Hereinafter, the direction of the axis 20 of the magnetic circuit unit 100 constituted by cylindrical or columnar parts indicated by a one-dot chain line in FIG. 1 is referred to as an axial direction.

A coil 7 wound around a bobbin 6 is inserted into a magnetic gap 5 having a high magnetic flux density formed between the inner wall surface of the outer yoke 1 and the outer circumferential surface of the inner yoke 3 in the magnetic circuit unit 100. . The bobbin 6 is bonded to the diaphragm 8 or integrally formed of the same material as the diaphragm 8 and is fixed to the diaphragm 8. The diaphragm 8 is elastically supported on the outer yoke 1 by the first elastic member 9. ing. In addition, the diaphragm 8 extends outward from the outer yoke 1, and the outer peripheral portion of the diaphragm 8 is a damper 80. The diaphragm 8 whose outer peripheral portion is a damper 80 is fixed to the case by a second elastic member 90 that connects the outer peripheral portion of the case 4 and the outer peripheral portion of the diaphragm 8 without a gap. The outer yoke 1 is fixed to the case 4 with bolts 13, and an acoustic space 22 is formed by the case 4, the outer side wall of the outer yoke 1 and the diaphragm 8. Here, the case 4 containing the outer yoke 1 is screwed and fixed at the bottom of the outer yoke 1, but it goes without saying that the fixing method between the case 4 and the outer yoke 1 may be other than screwing. . Further, a cover 14 is provided so as to cover the front surface of the diaphragm 8 in order to protect the diaphragm 8 from scattering of foreign matters such as small stones and sand on the road. The cover 14 includes a gallery 140 having an opening so that sound emitted from the diaphragm 8 is emitted forward. Although the opening of the cover 14 is a gallery 140, the shape of the opening is as long as it has an opening area that can protect the diaphragm 8 from scattering of foreign matter and does not block sound emitted from the diaphragm 8. It doesn't matter what it is. The cover 14 is provided with a drain hole 141 for draining water from the outside.

  In the case 4, an amplifier for driving the coil 7 is incorporated, and a waterproof substrate 10 is installed. The board 10 may incorporate an electronic circuit including a CPU for generating and controlling sound signals. The case 4 is provided with a connector 12 having a terminal 11 for electrical connection from the outside to an amplifier or electronic circuit of the substrate 10. When an electronic circuit for generating and controlling sound signals is incorporated in the board 10, vehicle information such as CAN (Controller Area Network), LIN (Local Interconnect Network), or hard wire is transmitted to the terminal 11. A communication line may be connected.

  FIG. 2 is a sectional view taken along the line AA in FIG. FIG. 3 is a cross-sectional view at the position BB in FIG. The outer shape of the case 4 is rectangular, and a drain tube 30a and a drain tube 30b are provided at two corner positions, respectively. The drain pipe 30 a and the drain pipe 30 b are connected to respective drain pipe outlets 31 opened in the case 4, and act as drain holes when water enters the acoustic space 22. For this reason, it installs so that at least one part of the drain pipe 30a or the drain pipe 30b may become the lowest part.

  As described above, the electrodynamic sound emitting body 200 according to the first embodiment is not only a hole provided in the wall of the case 4 as an opening for draining the acoustic space 22, but also the acoustic space 22 and the case 4. A drain pipe 30a and a drain pipe 30b having a space communicating with the outside are added. If a hole is simply made in the wall of the case 4 as a drain hole, sound is radiated from the acoustic space 22 to the back of the case 4 and interferes with sound radiated from the front surface. Deteriorates the frequency characteristics of the body. On the other hand, in the first embodiment, as shown in the cross-sectional view of FIG. 3, the length L from the opening on the acoustic space side of the drain tube 30a to the drain tube outlet 31 is provided by providing the drain tube 30a. Is longer than the wall thickness t of the case 4. If the length from the opening on the acoustic space side to the drain pipe outlet 31 is longer than the thickness of the wall of the case 4, the drain from the opening on the acoustic space side is easier than a case where a hole is simply made in the wall of the case 4. Attenuation of sound propagating to the tube outlet 31 is increased. As described above, since the drain pipe 30a is added, sound is attenuated while propagating through the drain pipe 30a, so that the sound pressure radiated from the drain pipe outlet 31 to the rear of the case 4 can be reduced. Therefore, an electrodynamic sound emitting body with reduced interference with the sound radiated from the front surface and less frequency characteristic degradation can be obtained. The drain tube 30b has the same configuration as the drain tube 30a.

  The case 4 is made of resin and is manufactured using a mold. In the electrodynamic sound emitting body used outside the vehicle, the resin used is required to have oil resistance to engine oil, chemical resistance to battery fluid, and heat resistance. As a resin that satisfies these requirements, for example, liquid crystal polymer (LCP), heat-resistant ABS, which is a synthetic resin of acrylonitrile, butadiene, or styrene, can be used. The drain tube 30 a and the drain tube 30 b are also formed in the mold of the case 4 so that the drain tube 30 a and the drain tube 30 b are also integrally formed with the case 4. In FIG. 1, the drain tube 30 a and the drain tube 30 b are provided so as to protrude toward the acoustic space 22, but the drain tube 30 a and the drain tube 30 b may be provided so as to protrude outside the case 4.

  FIG. 4 is a cross-sectional view showing a state where the electrodynamic sound emitting body 200 of FIG. In other words, a state in which α is tilted counterclockwise around the axis 20 from the state shown in FIG. FIG. 5 shows a state where it is tilted clockwise by α around the axis 20 from the state shown in FIG. In either case, of the two drain pipes 30a and 30b provided at the corners of the case 4, one drain pipe 30a or the drain pipe 30b is positioned at the lowermost position, so that water enters the acoustic space 22. In this case, water drains from the drain pipe 30a or the drain pipe 30b located at the lowermost position. When the cross-sectional shape of the case 4 is square and the drain pipes are provided at two adjacent corners, the tilt angle α is in the range of 90 degrees> α> −90 degrees. Since the drain pipe is positioned at the lowermost position, the electrodynamic sound emitting body 200 can be attached to be tilted within this range.

  It is conceivable that the electrodynamic sound emitting body 200 is attached to a car having various different specifications, for example. It is conceivable that the requirements for the position of the connector 12 differ between vehicles having different specifications. In this case, like the electrodynamic sound emitting body 200 according to the first embodiment, the drain tube 30a and the drain tube 30b are provided at two corners, so that the connector 12 can be simply changed by changing the mounting angle. There is an effect that the degree of freedom for the position is increased, and it is easy to satisfy the requirements for vehicles having different specifications.

Embodiment 2. FIG.
FIG. 6 is a cross-sectional view showing a cross section perpendicular to the axis 20 of the electrodynamic sound emitting body 200 according to the second embodiment of the present invention. 6, the same reference numerals as those in FIG. 2 denote the same or corresponding parts. In the first embodiment, the shape of the case 4 in the cross section perpendicular to the shaft 20 is square, but in the second embodiment, the shape of the case 4 in the cross section perpendicular to the shaft 20 is a combination of a circle and a straight line. Shaped. The drain tube 30a is arranged at a position where the straight line Q and the straight line Pa intersect. The inner angle β at which the straight line P and the straight line Q in FIG. 6 intersect is less than 180 degrees. That is, when the surface of the case 4 parallel to the axis 20 is a side surface, the side surface is configured by a curved surface and a plane, and the plane 41 and the plane 42 intersect with each other at an angle where the inner angle β is less than 180 degrees. The drain pipe 30a is disposed at a position where the planes intersect. In FIG. 6, the drain pipe 30 b is also disposed at a position where the plane 43 and the plane 41 intersect.

  FIG. 7 is a cross-sectional view showing a state where the electrodynamic sound emitting body 200 of FIG. In other words, a state in which α is tilted counterclockwise around the axis 20 from the state shown in FIG. Further, FIG. 8 shows a state in which it is inclined clockwise by α around the axis 20 from the state shown in FIG. In either case, of the two drain pipes 30a and 30b provided at the position where the planes intersect, one drain pipe 30a or the drain pipe 30b is located at the lowermost position, so that water has entered the acoustic space 22. In this case, water drains from the drain pipe 30a or the drain pipe 30b located at the lowermost position. Inclination angle α is in the range of 180 ° −β> α> − (180 ° −β), and any one of the drain tubes is positioned at the lowermost position. Therefore, electrodynamic sound emitter 200 is inclined and attached in this range. be able to.

  FIG. 9 is a sectional view showing a section perpendicular to the axis 20 of another electrodynamic sound emitting body according to the second embodiment of the present invention. 9, the same reference numerals as those in FIG. 6 denote the same or corresponding parts. In FIG. 9, as in FIG. 6, the shape of the case 4 is a combination of a circle and a straight line, but the position where the drain tube 30a and the drain tube 30b are arranged is a position where the curved surface and the plane intersect. For example, the drain pipe 30 a is disposed at a position where the cylindrical curved surface 44 and the flat surface 41 intersect. At the intersecting position, the inner angle β at which the curved surface 44 and the flat surface 41 intersect is a shape that is less than 180 degrees.

  As described above, the shape of the side surface of the case 4 includes at least two corners having an inner angle of less than 180 degrees at which two sides of the side surface of the case 4 intersect, and the drain pipes are arranged at the two corners. The two intersecting surfaces may be curved surfaces or flat surfaces. However, the surface connecting the two corners provided with the drain tube is preferably a flat surface or a curved surface that is convex toward the acoustic space 22 side. In the case of a curved surface having a concave on the acoustic space 22 side, there is a possibility that a portion where water does not escape is generated depending on the angle.

Embodiment 3 FIG.
FIG. 10 is a cross-sectional view showing a cross section perpendicular to the axis 20 of the electrodynamic sound emitter according to the third embodiment of the present invention. 10, the same reference numerals as those in FIG. 2 denote the same or corresponding parts. In the first and second embodiments, two drain tubes are arranged at the corners of the case 4. However, in the third embodiment, only one drain tube 30 is disposed at the corner of the case. It is arranged. In FIG. 10, the cross-sectional shape of the case 4 is rectangular as in the case 4 of FIG. 2, and the drain tube 30 is arranged at one of the four corners.

  As described above, even if the drain tube 30 is disposed only at one corner, if the inner angle β of the corner is less than 180 degrees, the tolerance of the attachment angle is 180 degrees−β. That is, the angle of both sides of the corner formed by the vertical line V at the position of the drain tube 30 is 180 degrees −β / 2 clockwise around the direction in which both are β / 2 as shown in FIG. It can be tilted 180 degrees to -β / 2 counterclockwise.

  In FIG. 10, the cross-sectional shape of the case side surface is a square shape. However, the shape is not limited to the square shape, and the shape of the side surface of the case 4 includes at least one corner having an inner angle of less than 180 degrees. It is sufficient that a drain pipe is disposed at at least one corner. The two intersecting surfaces may be curved surfaces or flat surfaces. With this configuration, the degree of freedom with respect to the position of the connector 12 can be increased simply by changing the mounting angle, and there is an effect that it is easy to satisfy requirements in vehicles having different specifications.

Embodiment 4 FIG.
FIG. 11 is a cross-sectional view showing a cross section perpendicular to the axis 20 of the electrodynamic sound emitter according to the fourth embodiment of the present invention. 11, the same reference numerals as those in FIG. 2 denote the same or corresponding parts. In the first embodiment, the second embodiment, and the third embodiment, the side surface shape of the case 4 has a corner portion, but the corner portion does not necessarily have a corner portion. FIG. 11 shows an electrodynamic sound emitting body having a circular cross section of the case 4 and no corners. The cross-sectional view of the electrodynamic sound emitting body 200 of FIG. 11 omitting the upper part at the CC position is the same as FIG.

Thus, even if the side surface shape of the case 4 is a shape that does not have a corner, the drain tube 30a functions as a drain hole by installing the drain tube 30a at the lowest position. Moreover, since the length from the opening on the acoustic space side of the drain pipe 30 to the drain pipe outlet 31 is longer than the thickness of the wall of the case 4, the length of the case 4 is simply a hole in the wall of the case 4. The effect that the sound pressure radiated from the drain pipe outlet 31 to the rear of the case 4 can be reduced is the same as that of the electrodynamic sound emitting body of the first to third embodiments. However, the mounting angle of the electrodynamic sound emitting body according to the fourth embodiment is limited.

  Therefore, in order to increase the degree of freedom of the mounting angle of the electrodynamic sound emitting body, the side surface shape of the case 4 is a shape having at least one corner portion described in the first to third embodiments, It is preferable to provide a drain pipe at at least one corner. Further, it is more preferable to provide a drain pipe at two corners adjacent to each other having a plurality of corners.

  It should be noted that the present invention can be combined with each other within the scope of the invention, or can be appropriately modified or omitted from each embodiment.

1: outer yoke 2: magnet 3: inner yoke 4: case 5: magnetic gap 7: coil 8: diaphragm 9: first elastic body 22: acoustic space 30, 30a, 30b: drain pipe 31: drain pipe outlet 90 : Second elastic body 200: electrodynamic sound emitting body

Claims (5)

A magnetic circuit part including an outer yoke having a bottom part and a side wall part, and a magnet and an inner yoke disposed between the outer yokes;
A coil disposed in a magnetic gap formed in the magnetic circuit section;
A diaphragm to which the coil is fixed;
A first elastic member that elastically connects the diaphragm and the side wall of the outer yoke;
A case covering the outer yoke;
A second elastic member that connects the outer periphery of the case and the outer periphery of the diaphragm without gaps, and an electrodynamic discharge comprising an acoustic space formed by the case, the diaphragm, and an outer surface of the side wall of the outer yoke. A sound body,
An electrodynamic sound emitting body comprising a drain pipe having a space for communicating the acoustic space with the outside of the case and formed integrally with the case.   The electrodynamic sound emitting body according to claim 1, wherein the drain pipe is provided on the acoustic space side.   2. The motion according to claim 1, wherein a side surface shape of the case has a corner portion where an inner angle between the surfaces is less than 180 degrees, and the drain pipe is provided in the corner portion. Electric sound emitting body.   4. The electrodynamic sound emitting body according to claim 3, wherein a plurality of the corner portions are provided, and drain tubes are respectively provided at two corner portions of the corner portions.   Two corners provided with the drain pipe are adjacent corners, and a side surface shape of the case connecting the adjacent corners is a flat surface or a curved surface convex toward the acoustic space side. The electrodynamic sound emitting body according to claim 4.

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