Speaker

Abstract

A speaker 10 comprises: a speaker main body 12 that emits sound forward; and a rear cover 14 that has a rear wall portion 50 disposed behind the speaker main body 12. The speaker main body 12 comprises a vibrating portion 20, a magnetic circuit 30, and a frame portion 42 for supporting the vibrating portion 20 and the magnetic circuit 30. The rear wall portion 50 has a contacting portion 53 that is in a state of contacting with the frame portion 42. The contacting portion 53 is located radially inward of a position at which the frame portion 42 supports an edge 24 of the vibrating portion 20.

Description

Speaker

[0001] The present disclosure relates to a speaker.

[0002] Patent Document 1 discloses a speaker that includes a speaker body and a case that houses the speaker body.

[0003] JP 2013-150264 A

[0004] In such a speaker, there is a risk that the rear wall disposed behind the speaker body will vibrate due to resonance with sound waves, which can cause a buzzing sound.

[0005] An object of the present disclosure is to provide a speaker that can suppress the occurrence of buzzing sounds.

[0006] The speaker of the first aspect is a speaker comprising a speaker body that emits sound forward and a rear cover having a rear wall portion that is positioned behind the speaker body, wherein the speaker body comprises a vibration portion, a magnetic circuit, and a frame portion that supports the vibration portion and the magnetic circuit, and the rear wall portion has a contact portion that is in contact with the frame portion, and the contact portion is located radially inward from the position where the frame portion supports the edge of the vibration portion.

[0007] In this aspect, the speaker includes a speaker body that emits sound forward, and a rear cover having a rear wall portion disposed behind the speaker body. The speaker body includes a vibration portion, a magnetic circuit, and a frame portion that supports the vibration portion and the magnetic circuit.

[0008] However, if the rear wall of the rear cover does not have sufficient rigidity, the rear wall may vibrate due to resonance with sound waves. Vibration of the rear wall can cause a buzzing sound. Therefore, in this embodiment, the rear wall has a contact portion that comes into contact with the frame portion. This increases the rigidity of the rear wall, or changes the vibration node, thereby changing the resonant frequency of the rear wall. As a result, vibration of the rear wall can be suppressed, thereby suppressing the generation of a buzzing sound.

[0009] In particular, in this aspect, the contact portion is located radially inward of the position where the frame portion supports the edge of the vibrating portion. This allows the contact portion to come into contact with the frame portion at a position closer to the center of the rear wall portion. As a result, vibration of the rear wall portion can be effectively suppressed.

[0010] Even if a portion of the rear wall comes into contact with the magnetic circuit, the effect of suppressing vibration of the rear wall can be achieved. However, because the magnetic circuit becomes hot due to heat generated when the speaker is driven, the portion of the rear wall that comes into contact with the magnetic circuit must have high heat resistance. In this regard, in this embodiment, the portion of the rear wall (contact portion) comes into contact not with the magnetic circuit but with a frame that supports the magnetic circuit, etc., and is spaced apart from the magnetic circuit, so high heat resistance is not required for the contact portion of the rear wall.

[0011] In the embodiments described below, the contact portion is a protruding contact portion that protrudes forward. However, the contact portion is not limited to this, and may not have a shape that protrudes forward. If the contact portion does not have a shape that protrudes forward, the frame portion may have a shape that protrudes rearward. In the embodiments described below, a plurality of contact portions are provided, and the contact portion is in contact at a plurality of locations (three locations that form a triangle surrounding the central axis of the speaker body when viewed from the front-to-rear direction). However, this aspect is not limited to this. There may be only one contact portion. In the embodiments described below, the rear cover is formed of a resin (e.g., polypropylene). However, the rear cover is not limited to this. In the embodiments described below, the frame portion is formed of a resin (e.g., polypropylene). However, the frame portion is not limited to this. In the embodiments described below, the contact portion is in direct contact with the frame portion. However, the contact portion in this aspect is not limited to this. The contact portion in this aspect may be in indirect contact with the frame portion via an elastic member such as an adhesive. In the embodiments described below, the rear cover includes a peripheral wall portion. However, the rear cover of this embodiment is not limited to this.

[0012] A speaker according to a second aspect is the speaker according to the first aspect, wherein the contact portion is a protruding contact portion that protrudes forward.

[0013] In this aspect, the contact portion is a protruding contact portion that protrudes forward, which makes it easier to simplify the structure of the frame portion compared to when the contact portion is not a protruding contact portion.

[0014] A speaker according to a third aspect is the speaker according to the second aspect, wherein the tip of the protruding contact portion has a spherical shape.

[0015] In this aspect, the tip of the protruding contact portion has a spherical shape, which allows the tip of the protruding contact portion to be in stable point contact with the frame portion.

[0016] A fourth aspect of the present invention is the speaker of the second or third aspect, wherein the frame portion has a contact recess provided at a position where the tip of the protruding contact portion comes into contact.

[0017] In this aspect, the frame portion has a contact recess provided at a position where the tip of the protruding contact portion comes into contact, and therefore the contact recess can be used to position the protruding contact portion.

[0018] A speaker according to a fifth aspect is the speaker according to the fourth aspect, wherein the contact portion is in contact with the frame portion via an elastic member.

[0019] In this aspect, the contact portion is in contact with the frame portion via the elastic member, which makes it easy to maintain the contact state of the contact portion with the frame portion.

[0020] The elastic member may be, for example, an adhesive, but may be an elastic member other than an adhesive (for example, a thin rubber member).

[0021] A speaker according to a sixth aspect is any one of the first to fifth aspects, wherein the contact portions are provided at multiple locations that form a polygon surrounding the central axis of the speaker body when viewed from the front-to-rear direction.

[0022] In this aspect, the contact portions are provided at a plurality of locations that form a polygon surrounding the central axis of the speaker body when viewed from the front-rear direction, thereby effectively suppressing vibration of the rear wall portion.

[0023] In the embodiments described below, the positions at which the multiple contact portions are provided are positions that form an equilateral triangle surrounding the central axis of the speaker body when viewed from the front-to-back direction, but they may also be positions that form a triangle other than an equilateral triangle, or positions that form a square or pentagon.

[0024] According to the present disclosure, a speaker capable of suppressing the occurrence of buzzing sounds is provided.

[0025] 1 is a cross-sectional perspective view of a speaker, a perspective view of a speaker body, and a perspective view of a rear cover.

[0026] A speaker 10 according to an embodiment will be described below with reference to the drawings. Fig. 1 is a cross-sectional perspective view showing the speaker 10 according to the embodiment. The speaker 10 according to the present embodiment is mounted in a vehicle, for example, and can be used as an external sound system (ESS) such as a warning horn or an acoustic vehicle alerting system (AVAS).

[0027] One side of the central axis of the speaker 10 is referred to as the front side, and the other side of the central axis is referred to as the rear side. In addition, in a direction perpendicular to the central axis, the side closer to the central axis is referred to as the radially inner side, and the side away from the central axis is referred to as the radially outer side. The speaker 10 of this embodiment is mounted in the front of the vehicle so that the front side of the speaker 10 faces downward of the vehicle.

[0028] As shown in FIG. 1, the speaker 10 includes a speaker body 12 (see FIG. 2), a rear cover 14 (see FIG. 3), and a front cover 16.

[0029] (Speaker body 12) The speaker body 12 comprises a vibrating section 20, a magnetic circuit 30, and a frame-integrated cover 40. The vibrating section 20 vibrates to produce sound. The vibrating section 20 comprises a diaphragm 22, an edge 24, a voice coil 26, and a damper 28. When a current flows through the voice coil 26, the voice coil 26 moves back and forth, causing the diaphragm 22 to vibrate and produce sound forward. The edge 24 supports the outer edge of the diaphragm 22 so that it can be displaced. The magnetic circuit 30 comprises a top plate, a magnet, and a yoke 32. In the figure, only the yoke 32 is shown.

[0030] The frame-integrated cover 40 is a resin molded product and includes a frame portion 42 that supports the vibration portion 20 and the magnetic circuit 30, and a peripheral wall portion 44.

[0031] The frame portion 42 has an edge support portion 45 that supports the outer edge portion of the edge 24. The edge support portion 45 has an annular shape, and the outer edge portion of the edge 24 is joined to the front surface of the edge support portion 45.

[0032] The frame portion 42 has a magnetic circuit support portion 46 that supports the magnetic circuit 30. The magnetic circuit support portion 46 is annular and supports the outer edge portion of the yoke 32 of the magnetic circuit 30. The magnetic circuit support portion 46 is located rearward of the edge support portion 45 and radially inward of the edge support portion 45. A portion (protruding portion) of the yoke 32 protrudes rearward from the inside of the annular magnetic circuit support portion 46. In other words, the magnetic circuit support portion 46 extends annularly so as to surround the portion (protruding portion) of the yoke 32.

[0033] As shown in FIG. 2, the magnetic circuit support portion 46 is connected to the edge support portion 45 by a plurality of connecting portions 47 provided at intervals in the circumferential direction.

[0034] As shown in Figure 2, contact recesses 49 are formed on the rear surface of the magnetic circuit support part 46. The contact recesses 49 are portions that come into contact with the later-described protruding contact parts 53, and the same number (three) of contact recesses 49 are provided as the number of protruding contact parts 53. The contact recesses 49 are recesses that are recessed toward the front side. The shape of the contact recesses 49 is approximately spherical (crater-shaped).

[0035] 1, the magnetic circuit support portion 46 supports the outer edge portion of the damper 28. Specifically, the outer edge portion of the damper 28 is joined to the front surface of the magnetic circuit support portion 46.

[0036] The peripheral wall 44 of the frame-integrated cover 40 constitutes the front portion of the peripheral walls 44, 61 of the speaker 10. The peripheral wall 44 has a cylindrical shape. The thickness direction of the peripheral wall 44 is oriented in the radial direction.

[0037] The frame-integrated cover 40 has a plurality of (three) engagement portions 44A. The engagement portions 44A protrude radially outward from the peripheral wall portion 44.

[0038] As shown in FIG. 2 , the frame-integrated cover 40 has mounting pieces 48. A plurality of (three) mounting pieces 48 are provided. The mounting pieces 48 protrude radially outward from the peripheral wall portion 44 of the frame-integrated cover 40. The mounting pieces 48 are formed with through holes 48A that penetrate in the front-to-rear direction. The speaker 10 is attached to an attachment target (a vehicle body member) by inserting a fastener such as a bolt into the through hole 48A.

[0039] In the frame-integrated cover 40, the front end of the peripheral wall portion 44 and the front end of the frame portion 42 are connected, and the peripheral wall portion 44 and the frame portion 42 are integrally formed.

[0040] (Rear Cover 14 ) The rear cover 14 includes a rear wall portion 50 and a peripheral wall portion 61 .

[0041] The rear wall portion 50 comprises a plate-shaped general portion 51 whose thickness direction is generally oriented in the front-to-rear direction, a lattice-shaped rib 52 formed on the front side of the general portion 51, and multiple (three) protruding contact portions 53 protruding forward from the general portion 51.

[0042] The general portion 51 has a central portion 51A that forms a circular region in the center of the general portion 51, and an outer peripheral portion 51B that surrounds the central portion 51A. The central portion 51A has a flat plate shape with its thickness oriented in the front-to-rear direction. The outer peripheral portion 51B is inclined forward from the radially inner side toward the radially outer side.

[0043] 3 , the front-rear direction position of the front ends of the lattice-shaped ribs 52 is constant along the extension direction of each rib constituting the lattice-shaped rib 52. The amount of protrusion of the lattice-shaped ribs 52 from the general portion 51 is zero at the radially outer end of the general portion 51. The front-rear direction position of the front ends of the lattice-shaped ribs 52 is located rearward of the rear surface of the magnetic circuit 30 of the speaker main body 12. In other words, the lattice-shaped ribs 52 are positioned at a distance from the magnetic circuit 30 in the front-rear direction.

[0044] As shown in Figure 3, the three protruding contact portions 53 have the same shape. Each protruding contact portion 53 has a cylindrical shape that protrudes forward from the general portion 51 of the rear wall portion 50. The protruding direction of each protruding contact portion 53 is parallel to the front-rear direction. The tip of each protruding contact portion 53 has a substantially spherical shape.

[0045] The three protruding contact portions 53 are provided at multiple locations (three locations) that form an equilateral triangle surrounding the central axis of the speaker body 12. The central axis of the speaker body 12 coincides with the central axis of the magnetic circuit 30. The three protruding contact portions 53 protrude from the central portion 51A of the central portion 51A and the outer peripheral portion 51B.

[0046] 1, the tip of the protruding contact portion 53 is in contact with the frame portion 42 of the speaker body 12. Specifically, the tip of the plurality of protruding contact portions 53 is in contact with a plurality of contact recesses 49 provided in the magnetic circuit support portion 46 of the frame portion 42. Note that, hereinafter, the protruding contact portion 53 may be referred to as the contact portion 53.

[0047] The peripheral wall portion 61 of the rear cover 14 constitutes the rear portion of the peripheral walls 44, 61 of the speaker 10. The peripheral wall portion 61 of the rear cover 14 and the peripheral wall portion 44 of the frame-integrated cover 40 constitute the peripheral walls 44, 61 of the speaker 10. The peripheral wall portion 61 has a cylindrical shape. The thickness direction of the peripheral wall portion 61 is oriented in the radial direction.

[0048] The rear cover 14 also includes a plurality of (three) locking portions 62. The locking portions 62 are provided so as to protrude forward from the front end of the peripheral wall portion 61, and lock onto the locked portions 44A of the frame-integrated cover 40.

[0049] 1, the rear cover 14 is attached to the frame-integrated cover 40 of the speaker body 12. Specifically, a plurality of locking portions 62 of the rear cover 14 lock onto a plurality of locked portions 44A of the frame-integrated cover 40. The peripheral wall portion 61 of the rear cover 14 and the peripheral wall portion 44 of the frame-integrated cover 40 are also joined together with an adhesive.

[0050] (Front Cover 16) As shown in FIG. 1, the front cover 16 includes a first front cover 16A and a second front cover 16B disposed rearward of the first front cover 16A.

[0051] The first front cover 16A is attached to the frame-integrated cover 40 of the speaker body 12. The first front cover 16A has a flat plate shape and has multiple through holes. An annular cushioning member 19 (e.g., a sponge-like member) is bonded to the front side of the first front cover 16A.

[0052] The second front cover 16B is attached to the frame-integrated cover 40 of the speaker body 12 and covers the vibrating unit 20 of the speaker body 12 from the front side. The second front cover 16B has multiple through-holes. The rear surface of the second front cover 16B is curved to follow the shape of the diaphragm 22. In other words, the second front cover 16B has a shape that protrudes toward the diaphragm 22. This prevents the diaphragm 22 from jumping out toward the front side while the speaker 10 is in operation. As a result, malfunctions due to sudden pressure changes are prevented.

[0053] <Operation and Effect> Next, the operation and effect of this embodiment will be described.

[0054] 1 , the speaker 10 includes a speaker body 12 that emits sound forward, and a rear cover 14 that has a rear wall portion 50 that is disposed behind the speaker body 12. The speaker body 12 includes a vibration portion 20, a magnetic circuit 30, and a frame portion 42 that supports the vibration portion 20 and the magnetic circuit 30.

[0055] However, if the rear wall 50 of the rear cover 14 does not have sufficient rigidity, the rear wall 50 may vibrate due to resonance with sound waves. Vibration of the rear wall 50 can cause rattling noise. Therefore, in this embodiment, as shown in FIG. 1 , the rear wall 50 has a contact portion 53 that comes into contact with the frame portion 42. This increases the rigidity of the rear wall 50, or changes the vibration node, thereby changing the resonant frequency of the rear wall 50. As a result, vibration of the rear wall 50 can be suppressed, thereby suppressing the generation of rattling noise.

[0056] 1, in this embodiment, the contact portion 53 is located radially inward of the position where the frame portion 42 supports the edge 24 of the vibrating portion 20 (the position of the edge support portion 45). Therefore, the contact portion 53 can be brought into contact with the frame portion 42 at a position closer to the center of the rear wall portion 50. As a result, vibration of the rear wall portion 50 can be effectively suppressed.

[0057] Note that even when a portion of the rear wall 50 is in contact with the magnetic circuit 30, the effect of suppressing vibration of the rear wall 50 can be achieved. However, because the magnetic circuit 30 becomes hot due to heat generated when the speaker 10 is driven, a high level of heat resistance is required for the portion of the rear wall 50 that comes into contact with the magnetic circuit 30. In this regard, in this embodiment, as shown in FIG. 1 , a portion of the rear wall 50 (contact portion 53) comes into contact not with the magnetic circuit 30 but with the frame portion 42 that supports the magnetic circuit 30 and the like, and is spaced apart from the magnetic circuit 30, so that a high level of heat resistance is not required for the contact portion 53 of the rear wall 50.

[0058] 1, the contact portion 53 is a protruding contact portion 53 that protrudes forward. Therefore, compared to when the contact portion 53 is not a protruding contact portion 53, it is easier to simplify the structure of the frame portion 42 side.

[0059] 1 and 3, the tip of the protruding contact portion 53 has a spherical shape, which allows the tip of the protruding contact portion 53 to be in stable point contact with the frame portion 42.

[0060] 2, the frame portion 42 has a contact recess 49 provided at a position where the tip of the protruding contact portion 53 comes into contact. Therefore, the contact recess 49 can be used to position the protruding contact portion 53.

[0061] In this embodiment, the contact portions 53 are provided at a plurality of locations that form a polygon (specifically, an equilateral triangle) surrounding the central axis of the speaker body 12 when viewed from the front-to-rear direction. This makes it possible to effectively suppress vibration of the rear wall portion 50.

[0062] In addition, in this embodiment, no adhesive or the like is applied between the tip of the protruding contact portion 53 and the contact recess 49. In other words, the contact portion 53 and the frame portion 42 are not bonded with adhesive. This eliminates the need for a step of applying adhesive to this location, making assembly easier.

[0063] However, the tip of the protruding contact portion 53 and the contact recess 49 may be joined with an adhesive. That is, the contact portion 53 and the frame portion 42 may be bonded with an adhesive. In this case, the contact portion 53 is in contact with the frame portion 42 via the hardened adhesive (elastic member). This makes it easy to maintain the contact state of the contact portion 53 with the frame portion 42. Note that the contact state of the contact portion 53 with the frame portion 42 may be achieved by disposing an elastic member other than adhesive (e.g., a thin rubber sheet) between the contact portion 53 and the frame portion 42. Even in this case, it is easy to maintain the contact state of the contact portion 53 with the frame portion 42. As a result, the contact state of the contact portion 53 with the frame portion 42 (the state in which the contact portion 53 and the frame portion 42 are connected) is maintained in the speaker 10.

[0064] [Supplementary Explanation] Although the preferred embodiments of the present disclosure have been described above, the present disclosure is not limited to the above-described embodiments.

[0065] In the above embodiment, the speaker body 12 includes the frame-integrated cover 40 in which the frame portion 42 and a portion of the peripheral wall portion 44 are integrally formed. In other words, the speaker body 12 includes the peripheral wall portion 44. However, the speaker body of the present disclosure is not limited to this, and may not include a peripheral wall portion.

[0066] In the above embodiment, the contact portion 53 is a protruding contact portion 53 that protrudes forward. However, the contact portion of the present disclosure is not limited to this and does not have to have a shape that protrudes forward. When the contact portion does not have a shape that protrudes forward, the frame portion may have a shape that protrudes backward.

[0067] In the above embodiment, three protruding contact portions 53 are provided. That is, three contact portions are provided. However, the number of contact portions in the present disclosure is not limited to this and may be one, or four or more.

[0068] In the above embodiment, the rear cover 14 includes the lattice-shaped ribs 52. However, the rear cover of the present disclosure is not limited to this, and does not necessarily need to include the lattice-shaped ribs.

[0069] In the above embodiment, the protruding contact portion 53 contacts the contact recess 49 of the magnetic circuit support portion 46 of the frame portion 42. However, the protruding contact portion of the present disclosure may contact the rear flat surface of the magnetic circuit support portion 46. Furthermore, the protruding contact portion of the present disclosure may contact a portion of the frame portion 42 other than the magnetic circuit support portion 46.

[0070] REFERENCE SIGNS LIST 10 Speaker 12 Speaker body 14 Rear cover 20 Vibration section 24 Edge 30 Magnetic circuit 42 Frame section 45 Edge support section 49 Contact recess 50 Rear wall section 53 Protruding contact section (contact section)

Claims

1. A speaker comprising: a speaker body that emits sound forward; and a rear cover having a rear wall portion that is positioned behind the speaker body, wherein the speaker body comprises: a vibration portion; a magnetic circuit; and a frame portion that supports the vibration portion and the magnetic circuit, wherein the rear wall portion has a contact portion that is in contact with the frame portion, and the contact portion is located radially inward from a position where the frame portion supports the edge of the vibration portion.

2. The speaker according to claim 1, wherein the contact portion is a protruding contact portion that protrudes forward.

3. The speaker according to claim 2, wherein the tip of the protruding contact portion has a spherical shape.

4. A speaker according to claim 2 or claim 3, wherein the frame portion has a contact recess provided at a position where the tip of the protruding contact portion comes into contact.

5. The speaker according to claim 1, wherein the contact portion is in contact with the frame portion via an elastic member.

6. The speaker according to claim 1, wherein the contact portions are provided at a plurality of locations that form a polygon surrounding the central axis of the speaker body when viewed from the front-to-rear direction.

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