JP2011035812A - Loudspeaker device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a loudspeaker device which attains thinning together with improvement in characteristics by using a height-reduced diaphragm, in which the shape rigidity is improved, and a damper having an inside diameter larger than an outer form of a magnetic circuit. <P>SOLUTION: On a surface of a diaphragm, a plurality of recessed portions arranged radially are formed from an outer circumferential side to an inner peripheral side to form a slope shape gradually deepened to an outer circumferential circle of a diaphragm annular part, having an outer diameter C substantially equal to an inner diameter of a damper, thereby improving the shape rigidity. Meanwhile, an annular part whose inner peripheral edge is mounted to a voice coil bobbin of a connecting member between the voice coil bobbin and the damper is brought into tight contact with a back of the annular part of the diaphragm and roots of the recessed portions, and is brought into tight contact with the annular part of the diaphragm and surfaces of the roots of the recessed portions in a flange part of a center cap, thereby suppressing concentration of stresses on the roots and simultaneously improving transfer power of a magnetic driving force. A tubular part of the connecting member connects the damper to the voice coil bobbin, while making the placement surface of the damper equal to the surface of a winding width center of a voice coil and suppresses lateral shaking of the voice coil during rolling of the diaphragm. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a speaker device, and more particularly to a speaker device using a low-profile diaphragm that is reduced in thickness.

FIG. 4 is a cross-sectional view showing a configuration of a standard low-profile speaker device that is currently generally used. When assembling a speaker system with this configuration or a similar speaker device, it is necessary to ensure the following four clearances:
(A) Clearance that covers the maximum amplitude forward of diaphragm 20 (b) Clearance between diaphragm 20 back surface and damper 21 outer periphery (c) Clearance between damper 21 back surface and magnetic circuit 22 front surface ( d) Clearance between the rear end of the voice coil 23 and the inner bottom surface of the magnetic circuit 22 Here, in principle, the amplitude clearance (a) of the diaphragm is equal to each of the other clearances (b) to (d). In a standard low-profile speaker device, it is impossible to reduce the thickness to a thickness of [(diaphragm amplitude) × 4] or less. However, strictly speaking, the thickness of the speaker device is [(diaphragm amplitude) × 4] + (1/2 of the voice coil winding width) + (bottom thickness of the magnetic circuit yoke). Must also be considered.

  As an example of reducing the thickness of a speaker device using a cone type diaphragm, there is a configuration in which a voice coil and a magnetic circuit are arranged in an inner space of the cone type diaphragm. In this case, in the configuration of FIG. 4, the connection relationship between the damper 21 and the voice coil 23 is not changed, and the cone-shaped diaphragm 20 is inverted and positioned between the rear surface of the damper 21 and the peripheral edge of the magnetic circuit 22. The length of the bobbin of the voice coil is increased, and the space between the damper arrangement surface and the voice coil winding center surface, which corresponds to the clearance (c) in FIG. The horizontal deflection of the line portion is increased and the magnetic circuit is easily contacted. Therefore, the defect due to the coil touch becomes remarkable as compared with a standard speaker. In addition, since the magnetic gap is exposed in the sound radiation direction on the outer surface of the speaker system, it is vulnerable to intrusion of dust, water droplets, etc. through the clearance (c), and air noise generated in the magnetic gap is not generated. The sound is radiated with sound, and the adverse effect on sound quality is inevitable. (For example, see Patent Document 1)

  A cone-shaped diaphragm having an inner diameter larger than the outer diameter of the magnetic circuit and a damper having an inner diameter larger than the outer diameter of the magnetic circuit are disposed outside the magnetic gap of the magnetic circuit at a normal position with respect to the inner periphery of the diaphragm. There is a speaker device that eliminates the need for the clearance (c) by using a member connected to the voice coil bobbin at the same level position. In this case, due to pressure fluctuations occurring in the space surrounded by the center pole of the magnetic circuit, the upper part of the bobbin, and the center cap that covers the upper end of the bobbin, a hole drilled in the bobbin above the coil, the inner surface of the connecting member, and the yoke Airflow concentrates on the path through the gap between the outer surface and air noise increases if this path is narrowed, and if it is widened, the connection between the connecting member and the bobbin becomes large, and Drive force transmission is reduced. A hole can be provided in the center pole to allow air to escape to the back of the speaker. However, in that case, it is necessary to provide a gap between the back of the speaker and the back of the speaker system, which hinders the reduction in thickness of the entire system. (See Patent Document 2)

  Similarly, by using a connecting member for connecting a damper having an inner diameter larger than the outer diameter of the magnetic circuit to the voice coil bobbin at the same level position as the magnetic gap outside the magnetic gap, the clearance (c) is not required. In this case, the inner periphery of the low-profile diaphragm is connected to the front end of the bobbin at the connection between the front end of the voice coil bobbin protruding to the front and the front end of the connecting member in order to secure clearance (b). To do. However, the low-profile type, that is, the flat diaphragm, has a problem that it is difficult to ensure the shape rigidity and the distortion characteristics are inferior in order to perform the vibration with the amplitude of the clearance (a). (See Patent Document 3)

  As a measure for increasing the rigidity of the flat diaphragm, it is already known to provide a concave portion in the flat plate portion (see, for example, Patent Document 4). However, if the concave portion is simply used, stress concentrates on the root portion. There is a problem of occurrence of a peak in frequency characteristics due to bending of this portion and occurrence of mechanical destruction at the time of large input.

  An open type magnetic circuit with a small thickness is used as the magnetic circuit, and a damper and a cone type diaphragm having an inner diameter larger than the outer diameter of the magnetic circuit are connected to a voice coil bobbin disposed in the magnetic gap at the center of the outer peripheral surface. Some speaker devices do not require the clearance (c), but in this case, since a closed magnetic circuit is not formed, the use efficiency of the magnet in the magnetic circuit is extremely low, which is disadvantageous in terms of acoustic conversion performance and cost. . (For example, see Patent Document 5)

Japanese Patent No. 2685175 JP 2002-271893 A JP 2005-269334 A Japanese Utility Model Publication No. 61-40097 Japanese Utility Model Publication No. 8-441

  As described above, in the standard low-profile speaker device, it is necessary to secure four clearances (a) to (d). In order to reduce the thickness of the speaker device, the total of these clearances and others are required. It is taught that the total thickness of the components must be reduced.

  In the configuration shown in Patent Document 1, an attempt is made to reduce the thickness by placing a magnetic circuit in the inner space of an inverted cone-shaped diaphragm, but the voice coil bobbin becomes longer, and the voice coil contacts the magnetic circuit when the diaphragm is rolled. As a result, noise is generated, and since the magnetic gap is exposed on the outer surface, it is vulnerable to intrusion of dust and the like, and air noise leaks, which has an adverse effect on sound quality.

  While the configuration of Patent Document 2 does not require the clearance (c), the problem of difficulty in selecting the dimension of the air flow path caused by the pressure fluctuation in the space surrounded by the voice coil bobbin on the upper surface of the magnetic circuit and the center cap thereof. Depending on the countermeasures adopted, sacrifices may be made in terms of increasing air noise, worsening transmission of driving force to the diaphragm, or increasing the thickness of the entire speaker system.

  The speaker device of Patent Document 3 also shows a configuration that does not require the clearance (c), but does not show a countermeasure for the problem of low shape rigidity of the low-profile diaphragm used in combination. In this respect, the installation of the concave portion on the diaphragm shown in Patent Document 4 may be one countermeasure, but a mechanical peak is generated due to the concentration of stress at the root of the concave portion or a large input machine. The problem of destructive remains.

  In the case of Patent Document 5, it is a speaker device that is thin but has a problem with low magnetic efficiency of an open magnetic circuit.

  The problem to be solved by the present invention is to employ a configuration that reduces the clearance (c) and a low-profile diaphragm as a reliable measure for reducing the thickness of the speaker device. If this occurs, the lateral vibration of the voice coil is reduced to prevent contact with the magnetic circuit, the performance of the electroacoustic conversion is improved by improving the performance related to the magnetic gap, and the low-profile diaphragm It is intended to provide a speaker device that can increase the shape rigidity of the speaker and efficiently transmit the driving force generated by the voice coil to the entire vibration system.

The speaker device of the present invention is the solving means according to claim 1, wherein the disc-shaped magnet, the center pole placed on the top surface of the magnet, and the bottom plate portion are brought into contact with the bottom surface of the magnet and the upper end inner peripheral surface of the outer peripheral wall portion. A magnetic circuit composed of a yoke that forms a magnetic gap facing the outer peripheral surface of the center pole, a voice coil bobbin in which a voice coil on the outer periphery of the lower end is movably inserted into the magnetic gap in the axial direction, and a center cap that closes the upper end opening of the voice coil bobbin A connecting member comprising an annular part having an inner peripheral edge attached to the outer periphery of the upper end of the voice coil bobbin, a cylindrical part extending from the outer peripheral edge of the annular part to the vicinity of the outer periphery of the upper end of the yoke substantially parallel to the voice coil bobbin, A damper with the inner peripheral edge attached to the outer periphery of the lower end of the connecting member, and the inner peripheral edge attached to the outer periphery of the upper end of the voice coil bobbin It consists of a low-profile diaphragm with an edge attached, and a frame that fixes and supports the bottom surface of the magnetic circuit, the outer peripheral edge of the damper, and the outer peripheral edge of the edge. The center cap includes a flange portion having an outer diameter larger than the inner diameter circle of the concave portion of the diaphragm, and the flange portion of the center cap and the annular portion of the connecting member are diaphragms. The inner peripheral flat plate portion is sandwiched from above and below to be coupled to the voice coil bobbin.
According to a second aspect of the present invention, in the speaker device according to the first aspect, the surface on which the center of the winding width of the voice coil is located and the surface on which the damper is disposed are made equal.
According to a third aspect of the present invention, in the speaker device according to the first aspect, the center cap and the flange portion are provided separately.

  According to the present invention, a low-profile diaphragm is attached to the outer periphery of the upper end of the voice coil bobbin at the inner periphery, and the inner periphery of the damper having an inner diameter larger than the outer diameter of the magnetic circuit is attached to the lower end of the connecting member at the outer periphery of the magnetic gap. This reduces the clearance between the back of the damper and the front of the magnetic circuit to reduce the thickness of the speaker device, and at the same time uses the clearance secured between the back of the diaphragm and the front of the damper to Providing shape rigidity to the low-profile diaphragm by providing a protruding concave portion on the diaphragm, and further, the center cap of the center cap having an outer diameter larger than the inner diameter circle of the concave portion from both the front and rear sides of the diaphragm By holding the flange part and the annular part of the connecting member in close contact with each other, the stress concentrated at the root of the concave part of the diaphragm is absorbed and dispersed. And the occurrence of the peak, to prevent mechanical destruction at the time of large input. In addition, by making the voice coil winding width center on the voice coil bobbin substantially the same as the damper mounting surface, horizontal vibration of the voice coil during rolling of the diaphragm is suppressed, and contact with the magnetic gap is caused. Prevent noise generation.

FIG. 1 is a plan view of a diaphragm used in the speaker device according to the present invention. 2 is a longitudinal sectional view of the speaker device according to the first embodiment of the present invention using the diaphragm of FIG. FIG. 3 is a longitudinal sectional view similar to FIG. 2 of the speaker device according to the second embodiment of the present invention using the diaphragm of FIG. FIG. 4 is a longitudinal sectional view showing an example of a conventional speaker device using a standard low-profile diaphragm.

  2 and 3 will be described with reference to FIGS. 2 and 3 for speaker devices that are reduced in thickness and improved in characteristics by Examples 1 and 2 using a low-profile diaphragm imparted with shape rigidity according to the present invention as shown in FIG.

  FIG. 1 shows a low-profile diaphragm 1 used in the speaker device according to the present invention, and FIG. 2 shows a configuration of the speaker device of Example 1 using the diaphragm 1. The diaphragm 1 is provided with a plurality of concave portions 2 arranged in a radial manner, thereby giving shape rigidity that is insufficient for a low-profile diaphragm. The concave portion 2 is provided on the outer peripheral portion side of the diaphragm 1 and forms a flat annular portion 3 on the inner peripheral portion along the inner peripheral edge 4. An edge 5 is attached to the outer peripheral end of the diaphragm 1. The shape of the concave portion 2 is arbitrary, but here, gradually from the outer peripheral side toward the inner peripheral side to the outer peripheral circle of the annular portion 3 so that the concentrated portion of stress that can be generated during vibration is on the inner peripheral side. As a deep slope type. The depth of the concave portion 2 is also set within the range of the clearance between the back surface of the diaphragm 1 and the upper surface of the damper 12 described later, that is, the clearance (b) described in FIG.

  The diaphragm 1 is attached to the outer peripheral surface of the upper end portion of the cylindrical voice coil bobbin 6 at the inner peripheral edge 4, and the voice coil 7 is wound around the outer peripheral surface of the lower end portion of the voice coil bobbin 6. The outer peripheral surface of the disc-shaped center pole 9 placed on the top surface of 8 and the inner peripheral surface of the upper end portion of the peripheral wall 11 of the yoke 10 that abuts the bottom surface of the magnet 8 around the magnet 8 by contacting the bottom surface of the magnet 8 Is inserted into a magnetic gap formed between the two. The voice coil bobbin 6 is further supported by a damper 12 having an inner diameter larger than the outer diameter of the magnetic circuit, which is movably moved in the axial direction, and is positioned on the same plane as the central surface of the winding width of the voice coil 7. For this reason, the connection member 13 which connects the upper end part outer peripheral surface of the voice coil bobbin 6 in which height positions differ, and the inner peripheral end of the damper 12 is used.

  The connecting member 13 includes an annular portion 13 a that is made to be the same size as the annular portion 3 of the diaphragm 1 and is arranged in close contact with the back surface side thereof, and an annular portion 13 a that abuts on the root of the concave portion 2 of the diaphragm 1. The inner peripheral edge of the annular portion 13 a is attached to the outer peripheral surface of the upper end portion of the voice coil bobbin 6 together with the inner peripheral edge of the annular portion 3 of the diaphragm. The cylindrical portion 13b extends to the vicinity of the outer peripheral surface of the upper end portion of the yoke peripheral wall 11, and is substantially at the same height as the winding width center of the voice coil 7 in the magnetic gap, that is, on the substantially same surface, the inner peripheral edge of the damper 12 Connected. The frame 15 mounts the bottom of the yoke 10 of the magnetic circuit at the center bottom, the outer peripheral edge of the damper 12 is at the center of the coil winding width in the middle step 15a spreading around the periphery, and the outer peripheral edge of the diaphragm in the upper step 15b. The outermost periphery of 5 is each hold | maintained and fixed.

  Holding the voice coil bobbin 6 with the damper 12 so that the surface passing through the center of the winding width of the voice coil 7 and the surface of the damper 12 are made substantially the same realizes the axial movement of the bobbin by magnetic drive. At the same time, it is also a holding position where the bobbin or coil can be minimized in the lateral direction perpendicular to the axial direction. Therefore, even if rolling occurs in the vibration mode of the diaphragm, the accompanying lateral vibration of the voice coil 7 is suppressed, so that contact with the magnetic gap of the coil is effectively prevented. Also, the suppression of the lateral vibration of the coil enables the magnetic gap to be minimized, that is, narrowed, thereby improving the magnetic driving force and extending the low frequency reproduction limit with a low resonance frequency.

  The center cap 14 that closes the upper open end of the voice coil bobbin 6 includes a flange portion 14 a that has a diameter D that exceeds the outer diameter of the voice coil bobbin 6 and that exceeds the diameter C of the outer circumference of the annular portion 3 of the diaphragm 1. Therefore, when the bobbin opening is closed by the center cap 14, the flange portion 14 a covers the annular portion 3 of the diaphragm 1, and a part of the inner peripheral side of the concave portion 2 and the radial leg portion 1 a between the concave portions 2. The diaphragm annular portion 3 is sandwiched from both sides together with the annular portion 13a of the connecting member 13 that covers the partial surface of the circumferential side and contacts the back side of the annular portion 3 of the diaphragm 1. Close to the circumferential root. As a result, the connection between the voice coil bobbin 6 and the vibration plate 1 and the damper 12 via the connecting member 13 is strengthened, and at the same time, the stress concentrated on the inner peripheral side of the concave portion 2 of the vibration plate 1 is absorbed and dispersed. Therefore, the magnetic driving force generated by the voice coil 7 is efficiently transmitted to the entire vibration system, and the vibration system significantly improves the frequency characteristics.

  The center cap 14 is also reduced in weight, and the flange portion 14a is provided with a concave surface portion 14b on the surface side of a plurality of portions located on the radial legs 1a of the diaphragm 1. In addition, as the magnetic gap narrows, the airflow or pressure fluctuation around the magnetic gap also becomes severe. However, the air passage 13c is formed in the cylindrical portion 13b of the connecting member 13 in the portion corresponding to the radial leg 1a of the diaphragm 1. Similarly, vents 15c are provided above and below the middle step portion 15a of the frame 15 at portions corresponding to the radial legs 1a.

  FIG. 3 shows a speaker device according to a second embodiment of the present invention. The difference from the speaker device according to the first embodiment is that the center cap 14 is closed by a main body portion that closes the upper end opening of the voice coil bobbin 6, and the flange portion is a main body portion. The ring plate 14c is separated and separated from the ring plate 14c. The ring plate 14c has an outer diameter D as in the first embodiment, and the annular portion 3 of the diaphragm 1 and the inner periphery of the radial leg portion 1a. It covers and adheres to the surface of a part of the side, and in close contact with the base portion of the concave portion 2 of the diaphragm together with the connecting member 13, absorbs and disperses the stress. Other configurations are the same as those of the first embodiment and function in the same manner.

DESCRIPTION OF SYMBOLS 1 Diaphragm 1a Radial leg part 2 Concave part 3 Annular part 4 Inner peripheral edge 5 Edge 6 Voice coil bobbin 7 Voice coil 8 Magnet 9 Center pole 10 Yoke 11 York peripheral wall 12 Damper 13 Connecting member 13a Annular part 13b Cylindrical part 13c Ventilation path 14 Center cap 14a Flange portion 14b Concave surface portion 14c Ring plate 15 Frame 15a Middle step portion 15b Upper step portion 15c Vent

Claims (3)

  From a disk-shaped magnet, a yoke that forms a magnetic gap by abutting the center pole and bottom plate placed on the top surface of the magnet with the bottom surface of the magnet and facing the outer peripheral surface of the center pole at the inner peripheral surface of the upper end of the outer peripheral wall A magnetic coil, a voice coil bobbin in which a voice coil on the outer periphery of the lower end is movably inserted in the magnetic axis direction, a center cap that closes the upper end opening of the voice coil bobbin, and an annular portion that has an inner periphery attached to the outer periphery of the upper end of the voice coil bobbin A connecting member comprising a cylindrical portion extending from the outer peripheral edge of the annular portion to the vicinity of the outer periphery of the upper end of the yoke substantially parallel to the voice coil bobbin; A low-profile diaphragm with an inner peripheral edge attached to the outer periphery of the upper end of the voice coil bobbin and an edge attached to the outer peripheral edge; The outer peripheral end of the par and the frame that fixedly supports the outer peripheral end of the edge, and the diaphragm includes a plurality of concave portions arranged radially with an inner diameter of a circle equal to the outer diameter of the annular portion of the connecting member, A flange portion having an outer diameter larger than the inner diameter circle of the concave portion of the diaphragm is provided, and the flange portion of the center cap and the annular portion of the connection member are coupled to the voice coil bobbin by sandwiching the inner peripheral side plate portion of the diaphragm from above and below. A speaker device characterized by that.   2. The speaker device according to claim 1, wherein a surface on which the winding width center of the voice coil is located and a surface on which the damper is disposed are made equal.   The speaker device according to claim 1, wherein the flange portion of the center cap is provided as a ring plate separate from the center cap body.

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