JP2011239125A - Edge and electrodynamic speaker using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrodynamic speaker suppressing a peak dip of a playback sound pressure frequency characteristics, enhancing efficiency, also sufficiently increasing a playback sound pressure level and improving playback audio quality, and suitable for attaching to devices such as a display, the electrodynamic speaker comprising an elongated edge including a support movable part connecting an inner peripheral part and an outer peripheral part.SOLUTION: The cross-section shape of the corner roll part of the edge comprises: a central flat plane part specified in correspondence to a central straight line part; an inner peripheral curved standing wall part specified in correspondence to an inner peripheral straight line part; and an outer peripheral curved standing wall part specified in correspondence to an outer peripheral straight line part, where each of the length of the central straight line part, the length of the inner peripheral straight line part and the length of the outer peripheral straight line part of the corner roll part increases from the minimum to the maximum between a long side part and a short side part, and then decreases to minimum again.

Description

  The present invention is an edge that supports an elongated, substantially rectangular diaphragm having a shorter minor axis direction than the major axis direction, and has excellent sound reproduction capability and is suitable for mounting on a device such as a display. It relates to electric speakers.

  In an audio device such as a display to which a speaker for reproducing sound is attached, it is desired to reduce the space required for attaching the speaker. In particular, elongate (rectangular, rectangular, oval (including elliptical, track-shaped)) electrodynamic speakers are divided vibrations that are characteristic of elongated speaker diaphragms, where the diaphragm area is limited in the minor axis direction. If you try to adopt a speaker magnetic circuit with a high magnetic flux density in a magnetic gap, the magnetic circuit is wider than the speaker diaphragm and cannot be downsized. For various reasons, there are disadvantages in sound reproduction capability. Therefore, conventionally, various speaker diaphragms, edges, speaker magnetic circuits, and electrodynamic speakers using the same have been proposed to solve these problems.

  In a conventional elongated speaker, a voice coil including an elongated coil having a major axis direction and a minor axis direction and an elongated bobbin, and an elongated diaphragm and an edge having a bobbin fixed to the center thereof are provided. Regarding electric type speakers, the outer peripheral end of the diaphragm and the inner peripheral part of the edge are formed of a set of long sides along the major axis direction and a set of arcs connecting the set of long sides. The outer peripheral part of the edge and the fixed part of the frame are formed of a pair of long sides along the major axis direction and a pair of short sides along the minor axis direction connecting the pair of long sides. The support movable part has a long side roll part corresponding to the long side of the track shape of the inner peripheral part, and a short side roll part corresponding to the arc of the inner peripheral part, and the short side The cross-sectional shape and dimensions of the roll part are the same as the connection part with the long side roll part. Gradually change so that the roll width becomes the largest in the vicinity of the long edge of the outer edge of the edge and the connection corner with the short side of the edge in the short diameter direction. There is an edge for a speaker (Patent Document 1).

  On the other hand, conventionally, in the case of a so-called square speaker in which the coupling portion with the roll edge has a diaphragm having a substantially rectangular edge, the curvature of the roll inside of the arc portion of the roll edge coupled to the corner of the diaphragm. There is a rectangular speaker having the same or larger than the outer curvature (Patent Document 2). The roll width of the edge part joined to the corner part of the diaphragm is larger than that of the straight part, and the inner circumferential curvature is large, so that the increase in compliance due to circumferential expansion and contraction is suppressed. And the overall compliance of the edge can be reduced, whereby the lowest resonance frequency can be reduced, and the low-frequency reproduction capability can be expanded.

  In addition, for example, the width of the corner of the edge of the rectangular flat plate diaphragm integrated with the cone having the voice coil attached to the frame is made larger than the width of the straight portion of the edge. There is a speaker device characterized in that is made equal to or smaller than the stiffness in the straight part (Patent Document 3). In the speaker device shown in FIGS. 3 and 4 of Patent Document 3, as a result of forming the width dimension at the corner portion of the edge larger than the width dimension at the straight portion of the edge, the cross-sectional shape of the corner portion 9b of the edge 9 has a roll shape. A straight line portion that is formed by extending the vertex of the edge appears. However, as for the shape of the corner portion 9b of the edge 9, the detailed configuration including the cross-sectional shape other than the cross-section illustrated in FIG. 4 of Patent Document 3 is unknown, and in the cross-section illustrated in FIG. At both ends of the portion, a single circular arc roll portion is formed which is substantially equal to the roll shape of the straight portion of the edge 9, and is continuous with the inner peripheral portion and the outer peripheral portion of the edge, respectively.

JP 2009-201005 A (FIGS. 1 and 2) Japanese Utility Model Publication No. 3-14878 (FIGS. 1a to 2b) Japanese Utility Model Publication No. 60-144390 (FIGS. 3 to 4)

  However, none of the prior art speakers are sufficient. The speaker described in Patent Document 1 is a special type including a track-type coil having a major axis direction and a minor axis direction, a voice coil including a track-type bobbin, and a track-type diaphragm in which the bobbin is fixed to the center. This is a case of a simple speaker and is not necessarily suitable for an elongated speaker having a substantially rectangular diaphragm. In addition, in the case of a substantially rectangular diaphragm that is close to a square, the edge described in Patent Document 2 or 3 is effective, but in the case of an elongated speaker having a rectangular diaphragm, the long side connected to the corner portion of the edge Since the configuration of the edge on the side and the short side is significantly different, there is a problem in that excessive stress is applied to the corner portion, the sound pressure frequency characteristics may be disturbed, or edge breakage may occur.

  The present invention has been made in order to solve the above-described problems of the prior art, and an object thereof is an electrodynamic type having an elongated edge including a support movable portion that connects an inner peripheral portion and an outer peripheral portion. For speakers, electrodynamic speakers that can suppress peak dip of playback sound pressure frequency characteristics, are highly efficient, have a sufficiently high playback sound pressure level, and have excellent playback sound quality and are suitable for mounting on devices such as displays. Is to provide.

  The edge of the present invention includes an inner peripheral portion that joins an outer peripheral end portion of an elongated diaphragm having a major axis direction and a minor axis direction, an outer peripheral portion that joins a fixed portion of the frame, an inner peripheral portion, and an outer peripheral portion. A long and narrow edge including a pair of long sides along the major axis direction, and a pair of long sides. It is a substantially rectangular shape defined by a set of short sides along the minor axis direction to be connected, and four corners that connect one long side and one short side in a substantially arc shape, and is movable. The long side roll part includes a single arc with a cross section corresponding to the long side part, and the full height is the same as the total height of the long side roll part including a single arc corresponding to the short side part. A short side roll part, and a corner roll part whose overall height is the same as the total length of the long side roll part and the short side roll part corresponding to the corner part. A central straight portion that is a straight line that defines the overall height, an inner circular arc portion that is an arc continuously formed at an inner peripheral end of the central straight portion, and a central portion An outer peripheral side arc portion that is an arc continuously formed at the outer peripheral end of the linear portion, and an inner peripheral linear portion that is a straight line formed continuously at the inner peripheral end of the inner peripheral side arc portion and connected to the inner peripheral portion And an outer straight line portion that is a straight line formed continuously to the outer peripheral end of the outer peripheral arc portion, and is connected to the outer peripheral portion, and the length of the central straight portion of the corner roll portion and the length of the inner peripheral straight portion The length of the outer straight line portion is defined corresponding to the central straight portion, increasing from the minimum to the maximum from the long side portion to the short side portion and then decreasing again to the minimum. Corresponding to the central plane portion that is a flat surface, the inner peripheral standing wall portion that is a curved surface defined corresponding to the inner peripheral straight portion, and the outer peripheral straight portion And an outer peripheral erect wall portion is a curved surface to be constant, but are formed respectively.

  Preferably, the edge of the present invention has a radius from the long side portion to the short side portion that defines the inner circular arc portion and the outer circular arc portion in the cross-sectional shape of the angular roll portion of the support movable portion of the edge. Reduce from maximum to minimum and then increase again to maximum.

  Preferably, the electrodynamic speaker of the present invention includes the above-described edge, a diaphragm to which the inner peripheral portion of the edge and the outer peripheral end thereof are joined, a frame to which the outer peripheral portion of the edge and the fixing portion thereof are joined, A voice coil coupled to the diaphragm and a magnetic circuit coupled to the frame and having a magnetic gap in which the coil of the voice coil is disposed.

  The operation of the present invention will be described below.

  The edge of the present invention includes an inner peripheral portion that joins an outer peripheral end portion of an elongated diaphragm having a major axis direction and a minor axis direction, an outer peripheral portion that joins a fixed portion of the frame, an inner peripheral portion, and an outer peripheral portion. A long and narrow edge including a pair of long sides along the major axis direction, and a pair of long sides. It is a substantially rectangular shape defined by a set of short sides along the minor axis direction to be connected and four corners that connect one long side and one short side in a substantially arc shape. The electrodynamic speaker of the present invention is connected to the edge, a diaphragm that joins the inner peripheral portion of the edge and the outer peripheral end thereof, a frame that joins the outer peripheral portion of the edge and the fixed portion thereof, and the diaphragm. And a magnetic circuit connected to the frame and having a magnetic gap in which the coil of the voice coil is disposed. Therefore, even when the space for mounting the audio equipment is narrow, an elongated electrodynamic speaker that is excellent in reproduction sound quality that can be mounted is realized.

  In the edge of the present invention, the movable movable portion includes a long-side roll portion including a single circular arc corresponding to the long side portion, and a total height including a single circular arc corresponding to the short side portion. Has a short side roll part that is the same as the total height of the long side roll part, and a corner roll part that has the same total height as that of the long side roll part and the short side roll part corresponding to the corner part. That is, this edge is a roll edge having a uniform height and a constant protruding dimension over the entire circumference of the elongated shape. The long side roll portion corresponding to the long side portion and the short side roll portion corresponding to the short side portion are roll edges each having a single cross section, and in some cases, a straight line in a part of the cross section. It is a roll edge including a part. The width of the long side roll part and the width of the short side roll part may be different. Preferably, the width in the cross-sectional shape of the long side part of the support movable part of the edge is the cross-sectional shape of the short side part. It is better to be larger than the width at.

  On the other hand, the angular roll part that connects the long side roll part and the short side roll part is a roll edge whose circumferential cross section is not composed of only a single arc. In the angular roll portion, the cross-sectional shape gradually changes depending on the angle in the circumferential direction, so that the long side roll portion and the short side roll portion can be smoothly connected. The width of the corner roll portion in the circumferential cross-sectional shape may be equal to or greater than either the width of the long side roll portion or the width of the short side roll portion. In the cross-sectional shape in the circumferential direction, the square roll portion is a central straight portion that is a straight line that defines the total height, an inner peripheral arc portion that is an arc formed continuously at the inner peripheral end of the central straight portion, An outer peripheral side arc portion that is an arc continuously formed at the outer peripheral end of the linear portion, and an inner peripheral linear portion that is a straight line formed continuously at the inner peripheral end of the inner peripheral side arc portion and connected to the inner peripheral portion And an outer straight line portion that is a straight line continuously formed on the outer peripheral end of the outer peripheral arc portion and is connected to the outer peripheral portion.

  Therefore, in the corner roll part, it corresponds to the central plane part which is a plane defined corresponding to the central straight part, the inner peripheral standing wall part which is a curved surface defined corresponding to the inner peripheral linear part, and the outer peripheral linear part And an outer peripheral standing wall portion which is a curved surface defined as described above. The length of the central straight part increases from the minimum to the maximum from the long side to the short side in accordance with the change in the angle in the circumferential direction, and then decreases to the minimum again. Form. In addition, the length of the inner peripheral linear portion is increased from the minimum to the maximum from the long side portion to the short side portion according to the change in the angle in the circumferential direction, and then reduced to the minimum again. This inner peripheral straight line portion forms an inner peripheral standing wall portion. Similarly, the length of the outer straight line portion is increased from the minimum to the maximum during the period from the long side portion to the short side portion according to the change in the angle in the circumferential direction, and then reduced to the minimum again. This outer peripheral straight portion forms the outer peripheral standing wall portion. On the other hand, the radius that defines the inner and outer circular arcs in the cross-sectional shape of the corner roll portion of the support movable part of the edge is reduced from the maximum to the minimum from the long side to the short side. Then increase again to the maximum.

  In this way, the overall height is defined in the cross-sectional shape in the circumferential direction so as to form not only a flat and strong central flat surface portion but also an inner peripheral vertical wall portion and an outer peripheral vertical wall portion that further increase rigidity in the corner roll portion. The central straight portion, inner peripheral straight portion, and outer peripheral straight portion are included, so that the rigidity of the corner roll portion is increased and the edge can endure excessive stress that tends to concentrate on the corner roll portion. It is possible to prevent breakage, suppress the peak dip of the reproduction sound pressure frequency characteristic, and improve the reproduction sound quality of the electrodynamic speaker using this edge. In the electrodynamic speaker of the present invention, by making the shape of the elongated edge as described above, even if the electrodynamic speaker has a substantially rectangular diaphragm, the divided vibration of the diaphragm is suppressed, and the efficiency is improved. In addition, the playback sound pressure level can be increased to improve playback sound quality and input resistance.

  The electrodynamic speaker of the present invention can suppress the peak dip of the sound pressure frequency characteristic of reproduction even if the electrodynamic speaker includes a substantially rectangular diaphragm having a major axis direction and a minor axis direction and an edge. Therefore, it is possible to provide an electrodynamic speaker that has high efficiency, a sufficiently high reproduction sound pressure level, and excellent reproduction sound quality.

It is a figure explaining the electrodynamic speaker 1 by preferable embodiment of this invention. Example 1 It is a figure explaining the edge 3 by preferable embodiment of this invention. Example 1 It is a figure explaining the corner roll part 30 of the edge 3 by preferable embodiment of this invention. Example 1 It is a figure explaining the change of the cross-sectional shape of the corner roll part 30 of the edge 3 by preferable embodiment of this invention. Example 1 It is a figure explaining the change of the cross-sectional shape of the square roll part 40 of the edge 3x of a comparative example. (Comparative Example 1)

  Hereinafter, although the electrodynamic speaker by preferable embodiment of this invention is demonstrated, this invention is not limited to these embodiment.

  FIG. 1 is a diagram for explaining an electrodynamic speaker 1 according to a preferred embodiment of the present invention. Specifically, the electrodynamic speaker 1 is a perspective view of the electrodynamic speaker 1 viewed obliquely from the front side. The electrodynamic speaker 1 of this embodiment is an elongated electrodynamic speaker having a substantially rectangular speaker diaphragm 2 having a major axis length of about 16.0 cm and a minor axis direction length of about 4.0 cm. As will be described later, a part of the structure of the electrodynamic speaker 1, the internal structure, and the like are omitted. The direction in which the straight line connecting the points A-A ′ extends is the major axis direction, and the direction in which the straight line connecting the points B-B ′ extends is the minor axis direction.

  The speaker diaphragm 2 having a substantially rectangular outer shape is a flat diaphragm formed by press-molding paper made of paper having five rectangular vibration surface portions each having a substantially rectangular shape with a slightly convex central portion. The end portion is supported, and the outer peripheral end portion of the edge 3 is fixed to the frame 6. A gasket 5 is connected to the front side of the outer peripheral end of the edge 3. In addition, the back side of the speaker diaphragm 2 includes a total of three (not shown) rectangular voice coils and a rectangular headband member (not shown) that connects these in a vertical and horizontal grid pattern (not shown). A voice coil assembly 4 (not shown) is connected. Note that the speaker diaphragm 2 may be a flat diaphragm that press-molds PSP, PP, foamed PP, paper, aluminum alloy, or the like, and is formed by punching a thin flat plate material. May be.

  In the voice coil assembly 4 (not shown), a rectangular headband member connects a rectangular voice coil correspondingly to three parts of the center and both ends of the five rectangular vibration surface parts, and a pair of adjacent rectangular voices. A rectangular space in which no voice coil is arranged is defined between the coils, and the rectangular voice coils are separated and connected in a substantially lattice shape. In the voice coil assembly of the present embodiment, the rectangular bobbin and the rectangular headband member are formed of an aluminum material that is lightweight and has sufficient rigidity when formed into a rectangular shape. Even if it does not make it the structure to make, the intensity | strength sufficient to drive the plane diaphragm 2 whole surface can be ensured. The speaker 1 drives the entire surface of the flat diaphragm 2 so that divided vibration hardly occurs and a flat frequency characteristic can be obtained.

  The frame 6 has an elongated shape corresponding to the track-shaped speaker diaphragm 2, and the magnetic circuit 10 fixed to the frame 6 also has an elongated shape having a narrow width less than the length in the minor axis direction. Specifically, the magnetic circuit 10 fixed to the frame 6 includes three magnetic circuits having magnetic gaps corresponding to the shapes of the three rectangular voice coils included in the voice coil assembly 4. Parts constituting the vibration system such as the magnetic circuit 10 and the voice coil assembly 4 are exposed from the window on the back side of the frame 6. Therefore, the electrodynamic speaker 1 is a speaker suitable for a device having a small width for mounting the speaker, such as a side portion of a display unit included in a device such as a display.

  A speaker vibration system including the speaker diaphragm 2, the edge 3, and the voice coil assembly 4 is supported so as to be able to vibrate with respect to the frame 6. In the electrodynamic speaker 1, when an audio current is supplied to the rectangular voice coil of the voice coil assembly 4, a driving force acts on the rectangular voice coil arranged in the magnetic gap of the magnetic circuit 10, and the voice coil assembly 4. Vibrates in the front-rear direction, and the connected speaker diaphragm 2 also vibrates in the front-rear direction. In the electrodynamic loudspeaker 1, the front and rear refer to the side where the voice coil 4 and the magnetic circuit 10 are attached when the speaker diaphragm 2 vibrates, and the speaker diaphragm 2 and the edge 3 are The exposed side is the front side.

  2, 3 and 4 are diagrams illustrating the edge 3 according to a preferred embodiment of the present invention. 2 is a plan view of the electrodynamic speaker 1 including the edge 3, and FIG. 3 is a portion S1 surrounded by a dotted line in the perspective view of FIG. FIG. FIG. 4 is a diagram for explaining a change in the cross-sectional shape of the corner roll portion 30 of the edge 3, and a state in which the cross-sectional shape changes by enlarging a portion S2 surrounded by a dotted line in the plan view of FIG. Includes a plurality of cross-sectional views showing the intervals at 15 ° intervals.

  The edge 3 is formed, for example, by impregnating rubber into a woven fabric in which a plurality of warp yarns and weft yarns of cotton and polyester fibers are substantially orthogonal to each other to form a base material, and heat-molding with a mold to cut the inner periphery and outer periphery It is a roll edge for an elongated speaker and has a thickness of about 0.2 mm. For example, the edge 3 is formed in a substantially annular shape by injecting foamed rubber into the mold, hot press molding and foaming to obtain a predetermined shape, and cutting the inner peripheral side and the outer peripheral side with a cutting die. The speaker edge may be formed in the shape of an elongated roll edge.

  The edge 3 includes a substantially rectangular and planar inner peripheral portion 31 that is joined to the outer peripheral end portion of the speaker diaphragm 2, a substantially rectangular and planar outer peripheral portion 32 that includes a plane that is joined to the frame 6, and the inner peripheral portion 31. The support movable part 33 comprised from the roll shape with which the cross section of the radial direction which connects the outer peripheral part 32 and the continuous was comprised. The front shape of the inner peripheral portion 31 and the outer peripheral portion 32 and the support movable portion 33 of the edge 3 is a set of long side portions along the major axis direction and a short axis direction connecting the pair of long sides. It is a substantially rectangular shape defined from a short side portion of a set and four corner portions that connect one long side and one short side in a substantially arc shape. Specifically, the outer dimensions of the edge 3 are about 139.1 mm in the major axis direction length and about 35.0 mm in the minor axis direction length. The inner dimension of the edge 3 is about 123.9 mm in the major axis direction length and about 19.8 mm in the minor axis direction length.

  The support movable portion 33 of the edge 3 has an up-roll shape that is convex in the forward direction as a whole, and corresponds to the long-side roll portion 34 including a single circular arc corresponding to the long-side portion and the short-side portion. The short side roll portion 35 whose cross section includes a single arc and the total height is the same as the total height of the long side roll portion 34, and the total height of the long side roll portion and the short side roll portion corresponds to the corner portion. And an angular roll portion 30 that is the same as the overall height. The long side roll portion 34 is a convex roll whose cross-sectional shape is defined by a single arc having a radius of 1.5 mm, its width Lw1 is about 3.5 mm, and its total height Lh is about 1.9 mm. The planar inner peripheral portion 31 and the outer peripheral portion 32 are connected to each other at the long side portion. Similarly, the short-side roll portion 35 is a convex roll whose cross-sectional shape is defined by a single arc having a radius of 1.5 mm, its width Lw2 is about 3.5 mm, and its overall height Lh is long. The planar inner peripheral portion 31 and the outer peripheral portion 32 are connected at the short side portion so as to be the same as the total height Lh of the side roll portion 34.

  FIG. 4 illustrates how the cross-sectional shape of the corner roll portion 30 formed following the long-side roll portion 34 and the short-side roll portion 35 of the edge 3 changes with a cross-sectional view shown at 15 ° intervals. FIG. As shown in FIG. 4, the cross-sectional shape of the corner roll portion 30 includes a convex roll defined by a single arc in the long side roll portion 34 when the angle is 0 degrees shown in FIG. In the case of an angle of 90 degrees shown in FIG. 4G, a convex roll in the short side roll portion 35 is included. The width Lw0 in the cross-sectional shape of the corner roll portion 30 is equal to the width Lw1 of the long-side roll portion 34 at an angle of 0 degrees and the angle even in the case of the angles of 15 degrees to 75 degrees shown in FIGS. It is the same as the width Lw2 of the short side roll part 35 at 90 degrees and is constant. In addition, the width Lw0 in the cross-sectional shape of the corner roll portion 30 depends on the angle in the range of Lw1 or less and Lw2 or more when the width Lw1 of the long side roll portion 34 is larger than the width Lw2 of the short side roll portion 35. It may change smoothly.

  The four square roll portions 30 are circular arcs formed continuously from the central straight portion 30a that is a straight line that defines the total height Lh and the inner peripheral end of the central straight portion 30a in the respective cross-sectional shapes in the circumferential direction. A circumferential arc portion 30b, an outer circumferential arc portion 30c that is an arc continuously formed on the outer peripheral end of the central linear portion 30a, and a straight line continuously formed on the inner peripheral end of the inner circumferential arc portion 30b. An inner peripheral straight portion 30d connected to the inner peripheral portion 31, and an outer peripheral straight portion 30e connected to the outer peripheral portion 32, which is a straight line formed continuously from the outer peripheral end of the outer peripheral arc portion 30c. The central straight portion 30a is a straight line extending in a direction substantially orthogonal to the direction in which the speaker diaphragm 2 and the voice coil assembly 4 vibrate. Therefore, the maximum height of the support movable portion of the edge 3 is the total height Lh over the entire circumference, and is substantially constant.

  The length of the central straight portion 30a of the corner roll portion 30 of the edge 3, the length of the inner peripheral straight portion 30d, and the length of the outer peripheral straight portion 30e respectively reach the short side roll portion 35 from the long side roll portion 34. In the meantime, the length is increased from the minimum to the maximum and then decreased again to the minimum. That is, the length of the central straight portion 30a, the length of the inner straight portion 30d, and the length of the outer straight portion 30e change as the angle in the circumferential direction changes, and each has an angle of 45 degrees shown in FIG. The longest around. Specifically, the length of the central straight portion 30a changes in the range of 0 mm to about 1.4 mm, and the length of the inner peripheral straight portion 30d changes in the range of 0 mm to about 1.6 mm. The length of the portion 30e varies in the range of 0 mm to about 1.0 mm.

  On the other hand, the radius that defines the inner circumferential side arc portion 30b and the outer circumferential side arc portion 30c in the cross-sectional shape of the corner roll portion 30 of the edge 3 is maximized from the long side roll portion 34 to the short side roll portion 35. Reduce to a minimum and then increase again to a maximum. That is, the radius that defines the inner circular arc portion 30b and the radius that defines the outer circular arc portion 30c are the smallest in the vicinity of an angle of 45 degrees shown in FIG. It is. The radius defining the inner circular arc portion 30b and the radius defining the outer circular arc portion 30c are the largest at an angle of 0 degrees shown in FIG. 4A to an angle of 90 degrees shown in FIG. 4G, respectively. Each of the long side roll part 34 or the short side roll part 35 continues to a single arc.

  As a result, in the corner roll portion 30 of the edge 3, as shown in FIG. 3, the central plane portion 30A, which is a plane defined corresponding to the central straight portion 30a, and the inner peripheral linear portion 30d are defined. An inner peripheral standing wall portion 30D that is a curved surface and an outer peripheral standing wall portion 30E that is a curved surface defined corresponding to the outer peripheral straight portion 30e (not shown because it is hidden behind the back surface) are formed. Moreover, in the corner roll part 30 of the edge 3, it is a curved surface prescribed | regulated corresponding to the inner peripheral side curved surface part 30B which is a curved surface prescribed | regulated corresponding to the inner peripheral side circular arc part 30b, and the outer peripheral side circular arc part 30c. An outer peripheral curved surface portion 30C is formed.

  As shown in FIG. 3, the central plane portion 30 </ b> A is a plane that gradually increases in width as it bends in the circumferential direction and further decreases in width thereafter. The inner peripheral standing wall portion 30D and the outer peripheral standing wall portion 30E are curved surfaces that gradually increase in width as they bend in the circumferential direction, and then decrease in width, and do not include a portion that is spherical when viewed locally. It is. On the other hand, the inner peripheral curved surface portion 30B and the outer peripheral curved surface portion 30C are curved surfaces that gradually become narrower as they bend in the circumferential direction, and then become wider, and are portions that are spherical when viewed locally. Is a curved surface. In the corner roll portion 30 of the edge 3, the central plane portion 30A, the inner peripheral curved surface portion 30B, the outer peripheral curved surface portion 30C, the inner peripheral standing wall portion 30D, and the outer peripheral standing wall portion 30E are smoothly continuous. .

  FIG. 5 is a diagram illustrating a change in the cross-sectional shape of the corner roll portion 40 of the edge 3x of the comparative example. The edge 3x of the comparative example is an edge having the same material, specifications, and dimensions, except that the cross-sectional shape of the corner roll portion 40 is different from the corner roll portion 30 of the edge 3 in the previous embodiment. Therefore, in the following, common parts are denoted by common numbers, and description thereof is omitted.

  The support movable portion 33 of the edge 3x of the comparative example includes a long-side roll portion 34 including a single circular arc corresponding to the long side portion, and a single circular arc corresponding to the short side portion. A short-side roll portion 35 whose overall height is the same as the overall height of the long-side roll portion 34, and a corner roll portion 40 whose overall height is the same as the overall height of the long-side roll portion and the short-side roll portion, corresponding to the corner portion, Have The long side roll portion 34 is a convex roll whose cross-sectional shape is defined by a single arc having a radius of 1.9 mm, its width Lw1 is about 3.5 mm, and its total height Lh ′ is about 1. The planar inner peripheral portion 31 and the outer peripheral portion 32 are connected at the long side portion so as to be 2 mm. Similarly, the short side roll portion 35 is a convex roll whose cross-sectional shape is defined by a single arc having a radius of 1.8 mm, its width Lw2 is about 3.5 mm, and its total height Lh ′ is The planar inner peripheral portion 31 and the outer peripheral portion 32 are connected to each other at the short side portion so as to be equal to the total height Lh ′ of the long side roll portion 34.

  As shown in FIG. 5, the cross-sectional shape of the corner roll portion 40 of the edge 3x of the comparative example is defined from a single arc at the long side roll portion 34 in the case of an angle of 0 degrees shown in FIG. The convex roll in the short side roll part 35 is included in the case of the angle 90 degree shown in FIG.5 (g). The width Lw0 in the cross-sectional shape of the corner roll portion 40 is equal to the width Lw1 of the long-side roll portion 34 at an angle of 0 degrees and the angle even in the case of the angles of 15 degrees to 75 degrees shown in FIGS. It is equal to the width Lw2 of the short side roll part 35 at 90 degrees.

  The four corner roll portions 40 of the edge 3x of the comparative example are continuously connected to the central straight portion 40a that is a straight line that defines the overall height Lh ′ and the inner peripheral end of the central straight portion 40a in the respective cross-sectional shapes in the circumferential direction. An inner circumference side arc portion 40b that is a formed arc and an outer circumference side arc portion 40c that is an arc formed continuously at the outer circumference end of the central straight portion 40a are included. The central straight portion 30a is a straight line extending in a direction substantially orthogonal to the direction in which the speaker diaphragm 2 and the voice coil assembly 4 vibrate. Therefore, the maximum height of the support movable portion of the edge 3 is the total height Lh ′ over the entire circumference and is substantially constant. Moreover, in the corner roll part 40, the inner peripheral linear part 30d in the angular roll part 30 of the edge 3 of an Example, or the linear part equivalent to the outer periphery linear part 30e is not formed in the cross-sectional shape of the circumferential direction.

  The length of the central straight portion 40a of the corner roll portion 40 of the edge 3x of the comparative example increases from the minimum to the maximum during the period from the long side roll portion 34 to the short side roll portion 35 and then decreases to the minimum again. To do. In other words, the length of the central straight portion 30a changes as the angle in the circumferential direction changes, and becomes the longest in the vicinity of the angle of 45 degrees shown in FIG. Specifically, the length of the central straight portion 30a varies in the range of 0 mm to about 1.6 mm.

  On the other hand, the radius that defines the inner circular arc portion 40b and the outer circular arc portion 40c in the cross-sectional shape of the corner roll portion 40 of the edge 3x of the comparative example is from the long side roll portion 34 to the short side roll portion 35. Reduce from maximum to minimum and then increase again to maximum. That is, the radius that defines the inner circular arc portion 40b and the radius that defines the outer circular arc portion 40c are the smallest in the vicinity of an angle of 45 degrees shown in FIG. It is. The radius defining the inner circular arc portion 40b and the radius defining the outer circular arc portion 40c are the largest at an angle of 0 degrees shown in FIG. 5A to an angle of 90 degrees shown in FIG. 5G, respectively. Each of the long side roll part 34 or the short side roll part 35 continues to a single arc.

  As a result, in the corner roll portion 40 of the edge 3x of the comparative example, a central plane portion 40A (not shown) which is a plane defined corresponding to the central straight portion 40a is formed, and corresponds to the inner circumferential side arc portion 40b. An inner peripheral curved surface portion 40B (not shown) that is a curved surface that is defined in the above, and an outer peripheral curved surface portion 40C that is a curved surface (not illustrated) that is defined in correspondence with the outer circular arc portion 40c are formed. . However, in the corner roll portion 40 of the edge 3x of the comparative example, like the corner roll portion 30 of the edge 3 of the embodiment shown in FIG. 3, the inner circumference is a curved surface defined corresponding to the inner circumference straight portion 30d. The standing wall portion 30D and the outer circumferential standing wall portion 30E that is a curved surface defined in correspondence with the outer circumferential straight portion 30e are not formed.

  As with the central plane portion 30A of the edge 3 of the embodiment shown in FIG. 3, the central plane portion 40A is a plane that gradually increases in width as it bends in the circumferential direction and then decreases in width. On the other hand, the inner circumferential curved surface portion 40B and the outer circumferential curved surface portion 40C are curved surfaces whose width gradually narrows as they bend in the circumferential direction, and then increase in width. Is a curved surface. In the corner roll portion 40 of the edge 3x, the central flat surface portion 40A, the inner peripheral curved surface portion 40B, and the outer peripheral curved surface portion 40C are smoothly continuous.

  The electrodynamic speaker 1 of the present embodiment includes the edge 3, the substantially rectangular speaker diaphragm 2, and the voice coil assembly 4. Therefore, the electrodynamic speaker 1 at 300 Hz or more that is likely to be generated by the elongated speaker diaphragm 2. Therefore, smooth frequency characteristics can be realized. In the edge 3 of the present embodiment, not only a flat central plate 30A that is strong against stress but also an inner peripheral wall 30D and an outer peripheral wall 30E that further increase rigidity are formed on the corner roll 30. In the cross-sectional shape in the circumferential direction, the central straight portion 30a defining the overall height, the inner peripheral straight portion 30d, and the outer peripheral straight portion 30e are included, so that the overall rigidity of the angular roll portion 30 is increased, Edges are prevented from being cut off by being able to withstand excessive stress that tends to concentrate on the corner roll portion 30, and the peak dip of the reproduction sound pressure frequency characteristics is suppressed. Quality can be improved.

  On the other hand, in the electrodynamic speaker 1x including the edge 3x of the comparative example (not shown), as described above, the edge 3x includes a flat central flat portion 40A on the corner roll portion 40, but further rigid. Since the portions corresponding to the inner peripheral standing wall portion 30D and the outer peripheral standing wall portion 30E in this embodiment are not formed, it is not sufficient to increase the rigidity of the corner roll portion 40 so as to withstand excessive stress that tends to concentrate. . As a result, in the corner roll portion 40 of the edge 3x, edge breakage may occur, and a peak dip is likely to occur in the reproduction sound pressure frequency characteristics.

  Therefore, the electrodynamic loudspeaker 1 of the present embodiment has a relatively flat reproduction even when the substantially rectangular speaker diaphragm 2 is used by making the shape of the elongated edge 3 as described above. Sound pressure frequency characteristics can be obtained. That is, the cross-sectional shape of the corner roll portion 30 of the edge 3 is a curved surface defined corresponding to the inner peripheral standing wall portion 30D and the outer peripheral straight portion 30e, which are curved surfaces defined corresponding to the inner peripheral straight portion 30d. Since the outer peripheral standing wall portion 30E is formed and gradually changes, the overall rigidity of the corner roll portion 30 is increased so that it can withstand excessive stress that tends to concentrate on the corner roll portion 30. Thus, it is possible to prevent edge breakage, suppress the peak dip of the reproduction sound pressure frequency characteristic, and improve the reproduction sound quality of the electrodynamic speaker 1 using this edge.

  Note that the edge 3 constituting the electrodynamic speaker of the present invention is not limited to the up-roll edge in which the support movable portion 33 is convex in the forward direction (concave in the rear direction) as in the above-described embodiment. The movable part 33 may be a down-roll edge that is concave in the forward direction (convex in the backward direction). Moreover, the edge 3 which comprises the electrodynamic speaker of this invention is not limited to the case of the said Example, The case where materials, such as foaming rubber | gum, or foaming urethane, is used may be sufficient. The elastic material forming the speaker edge may be molded by, for example, injecting rubber or elastomer into an injection mold. Alternatively, an elastomer sheet may be press-molded.

  The electrodynamic speaker of the present invention is not limited to a speaker using a substantially rectangular speaker diaphragm, but an elongated diaphragm that emits sound waves and an elongated drive member that transmits driving force to the elongated diaphragm. The present invention can also be applied to other electric-mechanical-acoustic transducers having other vibration systems that have a combination of shapes.

DESCRIPTION OF SYMBOLS 1 Electrodynamic type speaker 2 Speaker diaphragm 3 Edge 4 Voice coil assembly 5 Gasket 6 Frame 10 Magnetic circuit 30, 40 Square roll part 31 Inner peripheral part 32 Outer peripheral part 33 Support movable part 34 Long side roll part 35 Short side roll part

Claims (3)

An inner peripheral portion that joins the outer peripheral end of the elongated diaphragm having a major axis direction and a minor axis direction, an outer peripheral portion that joins the fixed portion of the frame, and a support that connects the inner peripheral portion and the outer peripheral portion An elongated edge including a movable part,
The front shape of the inner peripheral portion and the outer peripheral portion of the edge has a pair of long side portions along the major axis direction and a pair of short sides along the minor axis direction connecting the pair of long sides. A substantially rectangular shape defined by a side portion and four corners connecting one long side and one short side in a substantially arc shape;
The support movable part has a long side roll part including a single arc in a cross section corresponding to the long side part, and a total height of the long side roll including a single arc in a cross section corresponding to the short side part. A short side roll part that is the same as the total height of the roll part, and a corner roll part that has the same total height as the long side roll part and the short side roll part corresponding to the corner part,
In the cross-sectional shape in the circumferential direction, the angular roll portion is a central straight portion that is a straight line that defines the total height, and an inner peripheral side arc portion that is an arc formed continuously at the inner peripheral end of the central straight portion. And an outer peripheral side arc portion that is an arc continuously formed on the outer peripheral end of the central straight portion, and a straight line formed continuously on the inner peripheral end of the inner peripheral side arc portion. An inner straight line part to be connected, and an outer straight line part connected to the outer peripheral part which is a straight line formed continuously to the outer peripheral end of the outer peripheral side arc part,
The length of the central straight portion, the length of the inner peripheral straight portion, and the length of the outer peripheral straight portion of the angular roll portion are respectively minimized from the long side portion to the short side portion. A central plane portion that is a plane defined corresponding to the central straight line portion and an inner circumference that is a curved surface defined corresponding to the inner peripheral linear portion. A standing wall portion and an outer peripheral standing wall portion that is a curved surface defined corresponding to the outer peripheral straight portion are formed, respectively.
Edge. The radius that defines the inner circumference side arc part and the outer circumference side arc part in the cross-sectional shape of the corner roll part of the support movable part of the edge is maximum between the long side part and the short side part. From the minimum to the minimum and then to the maximum again,
The edge according to claim 1. The elongated edge according to claim 1 or 2,
The diaphragm to which the inner peripheral portion of the edge and the outer peripheral end portion are joined;
The frame to which the outer peripheral part of the edge and the fixed part are joined;
A voice coil coupled to the diaphragm;
A magnetic circuit coupled to the frame and having a magnetic gap in which the coil of the voice coil is disposed;
An electrodynamic speaker further equipped with