JP5932679B2 - Electromagnetic drive device and speaker - Google Patents

Description

  The present invention relates to an electromagnetic drive device configured by arranging a planar coil in a magnetic gap of a magnetic circuit, and a speaker for driving a diaphragm by energizing a voice coil in the magnetic gap.

  In general, a rectangular speaker includes a magnetic circuit composed of a magnet and a yoke that are opposed to each other via a magnetic gap, a voice coil that is movably disposed within the magnetic gap of the magnetic circuit, and a diaphragm connected to the voice coil. The voice coil is vibrated by the interaction between the magnetic flux crossing the magnetic gap and the current flowing in the voice coil. In such a loudspeaker, an electromagnetic driving device is constituted by components of a magnetic circuit and a voice coil, and usually a planar coil is used as the voice coil.

  Conventionally, as a flat coil used in a speaker, a flat α-winding coil is embedded in a recess formed in an insulating substrate, and a pair of lead portions which are ends of winding start and end of the flat α-winding coil are insulated substrate. The thing exposed to the outer surface of this is known (for example, refer patent document 1). In such a planar coil, a pair of linear portions extending in parallel along the longitudinal direction of the insulating substrate among the flat α-winding coils formed in a horizontally long track shape are effective coil portions that contribute to driving the planar coil. The pair of linear portions extending in parallel along the short direction of the insulating substrate are ineffective coil portions that do not contribute to the driving of the planar coil. Further, the pair of lead portions are led out to the ineffective coil portion of the insulating substrate, and the rectangular α-winding coil is energized through these lead portions.

International Publication No. WO2010 / 097974

  By the way, in the electromagnetic drive device as described above, the magnetic efficiency of the magnet is increased as the gap length of the magnetic gap is reduced. Therefore, in the conventional speaker disclosed in Patent Document 1, the voice length can be reduced by setting the gap length narrower. The coil can be driven efficiently. However, in a planar coil used as a voice coil, lead portions are led out at both ends of an insulating substrate, which is an ineffective coil portion, and the plate thickness of the portion is larger than that of the effective coil portion. It is necessary to set the entire magnetic gap to the gap length including the thickness of the lead portion, and it is difficult to increase the driving force of the speaker by narrowing the gap length.

  Such a problem is not limited to a speaker, but also in other devices including an electromagnetic driving device configured by arranging a planar coil in a magnetic gap, such as an optical pickup that drives an objective lens by an electromagnetic driving device. It is the same.

  The present invention has been made in view of the actual situation of the prior art, and a first object thereof is to provide an electromagnetic drive device having a large driving force, and a second object thereof is to provide a magnetic gap. An object of the present invention is to provide a speaker capable of narrowing the gap length.

  In order to achieve the first object, the present invention includes a rectangular parallelepiped magnet, a yoke disposed opposite to the magnet via a magnetic gap, and a planar coil having a flat α-turn coil mounted on an insulating substrate. An electromagnetic drive device in which the planar coil is movably disposed in the magnetic gap, wherein the flat α-winding coil includes a pair of first coil portions extending in a direction orthogonal to a moving direction of the planar coil, A pair of second coil portions extending along a moving direction of the planar coil, and a pair of lead portions led out from the second coil portions to the outer surface of the insulating substrate, the second coil portion and the leads The gap length of the magnetic gap in which the first coil portion is arranged is set narrower than the gap length of the magnetic gap in which the portion is arranged.

  In the electromagnetic drive device configured as described above, the second coil portion and the lead portion of the flat α-turn coil are ineffective coil portions that do not contribute to the driving of the planar coil. And the first coil portion, which is an effective coil portion, is arranged in a magnetic gap with a narrow gap length, so that the required gap length of the magnetic gap can be reduced and the total magnet The magnetic flux can be focused on the effective coil portion of the planar coil, and an electromagnetic driving device with a large driving force can be realized.

  In the above configuration, the protruding portion and the continuous paragraph portion at both ends thereof are integrally formed on the yoke, and the protruding portion is opposed to the first coil portion, and the paragraph portion is opposed to the second coil portion. It is preferable to do.

  In this case, if the magnet is sandwiched between a pair of plates to form a laminated body, and the side end surface of the laminated body and the side wall portion of the yoke are connected via a fastening member made of a nonmagnetic material, It is preferable because the gap length can be set easily and reliably. At that time, it is preferable that the fastening member is made of a flat metal plate having high thermal conductivity such as aluminum, because heat generated in the planar coil is radiated from the yoke through the fastening member, and the heat radiation effect is increased.

  In order to achieve the second object, the speaker of the present invention includes an electromagnetic drive device having the above-described configuration, a base to which the electromagnetic drive device is attached, and a vibration supported by the base via a damper. The vibration plate is connected to the insulating substrate of the planar coil.

  In the speaker configured as described above, the gap length of the magnetic gap is made different between the effective coil portion and the ineffective coil portion of the planar coil, and the gap length of the effective coil portion required for the magnetic circuit is set to an optimum dimension. Since the gap can be set, a speaker with a large driving force can be provided by narrowing the gap length.

  In the electromagnetic drive device of the present invention, the ineffective coil portion of the planar coil is disposed in the magnetic gap having a wide gap length, and the effective coil portion is disposed in the magnetic gap having a narrow gap length. The gap length of the magnetic gap can be reduced, and the total magnetic flux of the magnet can be focused on the effective coil portion of the planar coil, so that an electromagnetic drive device with a large driving force can be realized.

  Further, in the speaker of the present invention, the gap length of the magnetic gap is made different between the effective coil portion and the ineffective coil portion of the planar coil, and the gap length of the effective coil portion required for the magnetic circuit is set to an optimum dimension. Therefore, it is possible to provide a speaker with a large driving force by narrowing the gap length.

It is a top view of the speaker which concerns on the example embodiment of this invention. It is sectional drawing which follows the II-II line of FIG. It is sectional drawing which follows the III-III line of FIG. It is explanatory drawing of the voice coil board | substrate with which this speaker is equipped. It is explanatory drawing which shows the assembly process of this speaker. It is explanatory drawing which shows the assembly process of this speaker. It is explanatory drawing which shows the assembly process of this speaker. It is explanatory drawing of the magnetic circuit with which this speaker is equipped.

  The embodiment of the invention will be described with reference to the drawings. As shown in FIGS. 1 to 3, a speaker 1 according to this embodiment includes a base 2 having a pair of mounting surfaces 2 a and the like, and the base 2. The bottom plate 3, the magnet 4, and the top plate 5 fixed to each mounting surface 2 a in a stacked state, and the laminated body 6 composed of the bottom plate 3, the magnet 4, and the top plate 5 via two magnetic gaps G. The outer yokes 7 arranged in total, four fastening members 8 for fixing the outer yokes 7 to the corresponding laminates 6, the voice coil substrate 9 arranged in the magnetic gap G, and the magnetic gap G projecting A diaphragm 10 connected to the upper end of the voice coil substrate 9 and a damper 11 interposed between the back surface of the diaphragm 10 and the stepped portion 2b of the base 2 Te is mainly composed. Each of these members is housed in a bottomed frame (not shown), and the outer edge of the diaphragm 10 is connected to the frame via an edge.

  The base 2 is made of a nonmagnetic material such as aluminum, and the base 2 is formed with a pair of mounting surfaces 2a extending in parallel with a rectangular stepped portion 2b interposed therebetween. In addition, a pair of pedestals 2c is formed to project from the stepped portion 2b, and the lower surface of the damper 11 is bonded and fixed to the pedestals 2c. As shown in FIG. 2, the damper 11 is generally bowl-shaped, and its lower surface is formed in an annular shape having a corrugated cross section.

  The bottom plate 3, the magnet 4, and the top plate 5 are all plate-like members, and these three members constitute the laminated body 6 by sandwiching the magnet 4 between the bottom plate 3 and the top plate 5. Here, the bottom plate 3 is bonded and fixed on the mounting surface 2 a of the base 2, and the magnet 4 is bonded and fixed on the bottom plate 3, and the top plate 5 is bonded and fixed on the magnet 4. . However, the bottom plate 3 and the top plate 5 are somewhat wider than the magnet 4, and the bottom plate 3 and the top plate 5 are stacked so as to protrude from the magnet 4. A magnetic circuit is constituted by the laminated body 6 and the outer yoke 7, and the magnetic circuit has a two-gap structure having two magnetic gaps G. That is, the bottom plate 3 and the top plate 5 of the laminated body 6 function as an inner yoke, and a lower magnetic gap G is formed between the bottom plate 3 and the outer yoke 7, and the top plate 5 and the outer plate 7 An upper magnetic gap G is formed between the yoke 7 and the yoke 7. Further, a laminated body 6 in which the magnet 4 is sandwiched between the upper and lower plates 3, 5, an outer yoke 7 disposed opposite to the laminated body 6 with a magnetic gap G interposed therebetween, and a movable body disposed in the magnetic gap G. The voice coil substrate 9 constitutes an electromagnetic drive device.

  The outer yoke 7 includes a rectangular protruding portion 7a extending in parallel to face the laminated body 6, a pair of paragraph portions 7b bent from both longitudinal ends of the protruding portion 7a and extending outward, and a paragraph portion 7b. A pair of side wall portions 7 c that are bent at right angles to the rear and extend rearward are integrally formed. The entire length of the outer yoke 7 is set to be approximately the same as that of the laminated body 6 including the magnet 4 and the plates 3 and 5.

  The fastening member 8 is made of a flat nonmagnetic material having a high thermal conductivity such as aluminum, and the fastening member 8 is bonded and fixed to each side wall portion 7c of the outer yoke 7 and each side end surface of the laminated body 6, thereby The yoke 7 is connected to the laminated body 6 by a pair of fastening members 8 while maintaining a predetermined magnetic gap G.

  The voice coil substrate 9 is a planar coil disposed in the magnetic gap G of the magnetic circuit. As shown in FIG. 4, the voice coil substrate 9 is mounted on the rectangular insulating substrate 12 and the insulating substrate 12. And a flat α-winding coil 13. 4A and 4B are explanatory views schematically showing the voice coil substrate 9. FIG. 4A is a front view of the voice coil substrate 9, and FIG. 4B is a plan view of the voice coil substrate 9. FIG. (C) has shown the side view of the voice coil board | substrate 9, respectively.

  The flat rectangular α-wound coil 13 includes a pair of first coil portions 13a extending in a direction orthogonal to the driving direction of the voice coil substrate 9 (X-axis direction in FIG. 4), and a voice that is continuous with the first coil portions 13a. It has a pair of 2nd coil part 13b extended in the drive direction (Y-axis direction of FIG. 4) of the coil board | substrate 9, and the lead | read | reed part 13c derived | led-out from each 2nd coil part 13b, Of these, the 1st coil part 13a The second coil portion 13 b is embedded in the insulating substrate 12, but the lead portion 13 c is drawn out on the outer surface of the second coil portion 13 b and led upward along the outer surface of the insulating substrate 12. The first coil portion 13a is an effective coil portion (a portion indicated by an arrow A in FIG. 4) that contributes to driving the voice coil substrate 9, and the protruding portion 7a of the outer yoke 7 faces the effective coil portion A. Yes. Both ends of the flat α-winding coil 13 including the second coil portion 13b and the lead portion 13c are invalid coil portions (arrow B portion in FIG. 4) that do not contribute to driving of the voice coil substrate 9, and these invalid coil portions B The paragraph portions 7b of the outer yoke 7 are opposed to each other. The flat α-winding coil 13 may be attached to the surface of the insulating substrate 12 by adhesion.

  As shown in FIG. 8, the magnetic gap G of the magnetic circuit has different gap lengths near the center and both ends of the voice coil substrate 9, and the gap length of the effective coil portion A where the first coil portion 13a exists is G1. When the gap length of the reactive coil portion B where the second coil portion 13b and the lead portion 13c exist is G2, the gap length G1 of the effective coil portion A is set narrower than the gap length G2 of the reactive coil portion B ( G1 <G2). As a result, the gap length G1 required for the reactive coil portion B whose thickness is increased by the presence of the lead portion 13c can be secured, and the gap length G1 in the effective coil portion A can be set narrow. The driving force of the speaker 1 can be increased. Further, the outer yoke 7 faces the entire length of the laminated body 6, and the total length (effective length) of the magnet 4 is longer than the effective coil portion A of the voice coil substrate 9. The total magnetic flux can be focused on the effective coil portion A of the flat α-winding coil 13 to increase the magnetic flux density. Moreover, since the side wall 7c of the outer yoke 7 and the side end surface of the laminate 6 are connected by a fastening member 8 such as aluminum having a high thermal conductivity, the heat generated in the voice coil substrate 9 is fastened to the outer yoke 7. Heat can be efficiently radiated through the member 8. A pair of openings S are secured below the magnetic gap G so as to sandwich the voice coil substrate 9, and positioning jigs (an inner gap jig 14 and an outer gap jig 15) to be described later are provided through these openings S. Can be inserted and removed.

  The diaphragm 10 is formed in a rectangular shape in plan view, and the two outer edges of the diaphragm 10 facing each other are bonded and fixed to the upper end of the voice coil substrate 9 protruding above the magnetic gap G. Further, the above-described damper 11 is interposed between the center of the back surface of the diaphragm 10 and the stepped portion 2 b of the base 2, and the diaphragm 10 is linear in the driving direction of the voice coil substrate 9 by the damper 11. Is supported by the base 2 so as to vibrate.

  In the speaker 1 configured as described above, when the rectangular α-wound coil 13 is energized through the pair of lead portions 13c, the upper first coil portion 13a and the lower first coil portion in FIG. Since a reverse current flows through 13a, an electromagnetic driving force in the same direction acts on either first coil portion 13a. According to Fleming's left-hand rule, the direction of this electromagnetic driving force is in the Y-axis direction, so that the voice coil substrate 9 moves up and down in the magnetic gap G in the Y-axis direction. Is supposed to occur.

  Next, the assembly process of the speaker 1 according to the present embodiment will be described with reference to FIGS.

  First, as shown in FIG. 5 (a), a base 2 on which a pair of mounting surfaces 2a, a stepped portion 2b, and the like are formed is prepared. As shown in FIG. The bottom plate 3 is bonded and fixed to the placement surface 2a. Next, as shown in FIG. 5C, after the magnet 4 is bonded and fixed on the bottom plate 3, the inner gap jig 14 is placed outside the bottom plate 3 and the magnet 4 as shown in FIG. Place. The inner gap jig 14 is formed with a plate-like positioning protrusion 14a having a predetermined thickness. The thickness of the positioning protrusion 14a causes the inner surface of the voice coil substrate 9 and the inner yoke (the bottom plate 3 and the top plate) to be formed. 5) is defined.

  Next, as shown in FIG. 6A, the top plate 5 is bonded and fixed on the magnet 4 to form a laminate 6 in which the magnet 4 is sandwiched between the bottom plate 3 and the top plate 5. Note that the step of arranging the inner gap jig 14 shown in FIG. 5D is omitted, the top plate 5 is bonded and fixed on the magnet 4 to form the laminated body 6, and then the inner gap is formed outside the laminated body 6. The jig 14 may be arranged.

  Next, as shown in FIG. 6 (b), after the voice coil substrate 9 is arranged outside the inner gap jig 14, the outer gap is cured outside the voice coil substrate 9 as shown in FIG. 6 (c). The tool 15 is arranged. The outer gap jig 15 is formed with a plate-shaped positioning projection 15a having a predetermined thickness. The thickness of the positioning projection 15a causes the outer surface of the voice coil substrate 9 and the projection 7a of the outer yoke 7 to be formed. The clearance between them is regulated.

  Next, as shown in FIG. 6 (d), the outer gap 7 is disposed outside the outer gap jig 15, and the protrusion 7a of the outer yoke 7 is pressed against the positioning protrusion 15a to thereby fix the inner gap. The positioning protrusion 14 a of the tool 14 is brought into pressure contact with the bottom plate 3 and the top plate 5 of the laminate 6. At this time, the stage 7 b of the outer yoke 7 faces the ineffective coil portion B of the voice coil substrate 9 in a non-contact state, so that the pressing force from the outer yoke 7 does not act on the lead portion 13 c of the voice coil substrate 9.

  Next, as shown in FIG. 7A, the fastening member 8 is bonded and fixed to the side wall surface 7c of the outer yoke 7 and the side end surface of the laminated body 6 while maintaining this state, and both ends of the outer yoke 7 in the longitudinal direction are fixed. The part is connected to the laminate 6 through a pair of fastening members 8.

  Next, as shown in FIG. 7B, after the bottom surface of the damper 11 is bonded and fixed to a pair of bases 2c provided on the stepped portion 2b of the base 2, as shown in FIG. 7C. The back surface of the diaphragm 10 is bonded and fixed to the upper ends of the dampers 11, and the opposite outer edges of the diaphragm 10 are bonded and fixed to the upper ends of the voice coil substrates 9. At that time, since the voice coil substrate 9 is sandwiched between the inner gap jig 14 and the outer gap jig 15 and the position thereof is regulated, the diaphragm 10 can be simply bonded and fixed to the voice coil substrate 9. Can do.

  Next, as shown in FIG. 7D, when the inner gap jig 14 and the outer gap jig 15 are extracted along the plate surface of the voice coil substrate 9 in the direction away from the diaphragm 10 (downward in the drawing). A magnetic gap G is formed between the inner yoke (the bottom plate 3 and the top plate 5) and the outer yoke 7. As a result, an opening S corresponding to the cross-sectional shape of the positioning protrusions 14a and 15a is formed below the magnetic gap G, and the speaker 1 as shown in FIGS. 1 to 3 is obtained. Finally, the base 2 is housed in a frame (not shown) together with the components of the magnetic circuit, the diaphragm 10 and the like, and the upper opening end of the frame and the outer edge of the diaphragm 10 are connected by an edge, The assembly work of the speaker 1 is completed.

  As described above, in the speaker 1 according to the present embodiment, the voice coil substrate 9 is a planar coil in which the flat α-turn coil 13 is mounted on the insulating substrate 12, and the voice coil substrate 9 is disposed. The gap length of the magnetic gap G is made different between the effective coil portion A and the reactive coil portion B of the flat α-turn coil 13, and the gap length G2 of the reactive coil portion B where the second coil portion 13b and the lead portion 13c are present. The gap length G1 of the effective coil portion A where the first coil portion 13a exists is narrowed. As a result, the gap length G1 required for the reactive coil portion B whose thickness is increased by the presence of the lead portion 13c can be secured, and the gap length G1 in the effective coil portion A can be set narrow. The driving force of the speaker 1 can be increased.

  Further, in the speaker 1 according to this embodiment, a pair of paragraph portions 7b are formed integrally with the outer yoke 7 with the protruding portion 7a interposed therebetween, and the protruding portion 7a is formed as an effective coil portion A (first coil) of the voice coil substrate 9. Since the paragraph portion 7b is opposed to the ineffective coil portion B (the second coil portion 13b and the lead portion 13c), the gap length G1 and the gap length G2 are different depending on the shape of the outer yoke 7. Can be made. Moreover, since the side wall 7c of the outer yoke 7 and the side end surface of the laminate 6 are connected by a fastening member 8 such as aluminum having a high thermal conductivity, the heat generated in the voice coil substrate 9 is fastened to the outer yoke 7. Heat can be efficiently radiated through the member 8.

  In the above-described embodiment, the speaker 1 is illustrated and described as a device including an electromagnetic driving device. However, other devices including an electromagnetic driving device in which a planar coil is disposed in a magnetic gap of a magnetic circuit, for example, electromagnetic The present invention can also be applied to an optical pickup that drives an objective lens by a driving device.

DESCRIPTION OF SYMBOLS 1 Speaker 2 Base 2a Mounting surface 2b Stepped part 2c Base 3 Bottom plate 4 Magnet 5 Top plate 6 Laminated body 7 Outer yoke 7a Protrusion part 7b Paragraph part 7c Side wall part 8 Fastening member 9 Voice coil board (plane coil)
DESCRIPTION OF SYMBOLS 10 Diaphragm 11 Damper 12 Insulation board 13 Flat alpha winding coil 13a 1st coil part 13b 2nd coil part 13c Lead part G Magnetic gap G1, G2 Gap length

Claims (5)

It has a rectangular parallelepiped magnet, a yoke disposed opposite to the magnet via a magnetic gap, and a planar coil having a flat α-coil mounted on an insulating substrate, and the planar coil is movably disposed within the magnetic gap. In the electromagnetic drive device
The flat α-winding coil includes a pair of first coil portions extending in a direction orthogonal to the moving direction of the planar coil, a pair of second coil portions extending along the moving direction of the planar coil, and these second coils. A pair of lead portions led out from the portion to the outer surface of the insulating substrate,
An electromagnetic driving device characterized in that a gap length of a magnetic gap in which the first coil portion is arranged is set narrower than a gap length of a magnetic gap in which the second coil portion and the lead portion are arranged. .   2. The projection according to claim 1, wherein the yoke is integrally formed with a projecting portion and a paragraph portion continuous at both ends thereof, the projecting portion is opposed to the first coil portion, and the paragraph portion is disposed on the second coil. Electromagnetic drive device characterized by facing the part.   3. The laminate according to claim 2, wherein the magnet is sandwiched between a pair of plates to form a laminate, and the side end surface of the laminate and the side wall of the yoke are connected via a fastening member made of a nonmagnetic material. An electromagnetic drive device characterized by.   4. The electromagnetic drive device according to claim 3, wherein the fastening member is made of a metal flat plate having high thermal conductivity.   5. An electromagnetic drive device according to claim 1, a base to which the electromagnetic drive device is attached, and a diaphragm supported by the base via a damper. A speaker connected to the insulating substrate of a planar coil.