JP5413004B2 - Corrugation damper and speaker - Google Patents

Description

  The present invention relates to a corrugation damper and a speaker having the same.

  FIG. 11 is a diagram of a display screen showing a half view of a conventional corrugation damper used for a speaker when viewed obliquely from above. FIG. 12 shows a cross-sectional view of a conventional corrugation damper. As shown in these drawings, the corrugation (wave portion) has a wave shape like a non-disturbing surface wave spreading from the center of the corrugation damper. That is, as shown in FIG. 12, the height (amplitude) h of each peak 81 of the waveform is always constant without changing in the circumferential direction of the corrugation.

  FIG. 13 is a diagram of a display screen that displays the result of structural analysis of the conventional corrugation damper as shown in FIG. 11 assuming the force applied in the actual operating state in the speaker. A dark colored portion appearing closer to the center of the corrugation damper is a portion with high stress. It can be seen that the stress above the predetermined value is distributed concentrically on the inner peripheral side of the corrugation damper.

  A corrugation damper is known in which the width, height, shape, and the like of the corrugation mountain are changed in the radial direction. For example, the height of the corrugation peak is gradually reduced from the inner circumference side to the outer circumference side so that the stiffness of the corrugation damper decreases from the inner circumference side to the outer circumference side, or the width of the mountain is sequentially reduced from the inner circumference side to the outer circumference side. The thing which made it become large is known (for example, refer patent document 1). In addition, there is also known one in which the width of the corrugation is changed in order to make the flexibility per unit length in the radial direction of the corrugation damper substantially equal (see, for example, Patent Document 2).

JP 2001-326993 A Japanese Patent Laid-Open No. 11-127497

  However, as a problem with general corrugation dampers, the sound quality of the speaker deteriorates due to low linearity when changing from small amplitude to large amplitude, distortion due to amplitude asymmetry, and distortion due to resonance. The problem of letting it go is known. As for amplitude linearity, it is generally known that a butterfly damper is better than a corrugation damper. However, the butterfly damper has a drawback that it is likely to break when it vibrates with an extremely large amplitude.

  An object of the present invention is to provide a corrugation damper that further improves the sound quality of a speaker in view of the problems of the prior art.

To this end, the corrugation damper in accordance with the first invention, have a undulating crests of each annular constituting the corrugations in the circumferential direction, the undulations of the annular ridges, regular high and low during the round Repeated multiple times, starting from a predetermined intermediate height, gradually changing the height, going through the highest height, middle height, and lowest height in this order, the middle height It is characterized in that the change in the height of the unit cycle of returning to is repeated by a predetermined number of cycles while making a round of the annular ridge .

The corrugation damper according to a second invention is the corrugation damper according to the first invention, wherein the predetermined number of cycles is the same in each annular ridge, and the starting point of the unit cycle in each annular ridge is from the annular ridge on the inner peripheral side. It is characterized in that it is shifted sequentially by a predetermined angle centered on the damper center over the outer peripheral annular ridge.

The corrugation damper according to a third aspect of the present invention is the first or second aspect of the present invention , as viewed in cross-section, each annular peak is a curved portion having a constant radius of curvature including the apex, and a linear shape adjacent to both sides of the curved portion. , The arrangement interval between the annular ridges is constant, and the curvature radius of the curved portion of each annular ridge is the same.

A speaker according to a fourth aspect of the invention includes a plurality of corrugation dampers according to any one of the first to third aspects of the invention.

The speaker according to a fifth aspect is the speaker according to the fourth aspect , wherein the plurality of corrugation dampers have the same undulation direction in the corrugation dampers adjacent to each other, or the undulation directions are reversed. And

A speaker according to a sixth aspect of the present invention is the corrugation damper according to the second aspect of the present invention, characterized in that it has a plurality of speakers in which the angular directions of the sequential deviations are the same or opposite to each other.

  According to the present invention, the sound quality of the speaker can be further improved.

It is the top view of the corrugation damper which concerns on one Embodiment of this invention, and its AA sectional view taken on the line. It is sectional drawing to which the right half of FIG.1 (b) was expanded. It is sectional drawing to which a part of FIG. 2 was expanded. It is a figure which shows a mode that the height of each mountain in the corrugation damper of FIG. 1 changes in the circumferential direction. It is a figure which shows the starting point of the 10 reciprocation change about each mountain in the corrugation damper of FIG. It is a figure of the display screen which shows the mode of the change of the height of each mountain in the corrugation damper of FIG. It is the figure which represented FIG. 6 by the ridgeline of R bottom. It is a figure of the display screen which displays the structural analysis result about the corrugation damper of FIG. It is a figure which shows the result of having measured the admittance by driving the speaker using the corrugation damper of FIG. It is a figure which shows the result of having measured the admittance by driving the speaker using the conventional corrugation damper. It is a figure of the display screen which shows a mode that the conventional corrugation damper was seen from diagonally upward. It is a figure which shows the mode of the cross section of the conventional corrugation damper. It is a figure of the display screen which displays the structural analysis result about the conventional corrugation damper.

  Fig.1 (a) is a top view of the corrugation damper based on one Embodiment of this invention, The same figure (b) is the AA sectional view taken on the line. In the figure, 1 is a corrugation damper, 2 is an inner peripheral portion for supporting a speaker diaphragm and a voice coil bobbin, 3 is an outer peripheral portion fixed to the speaker frame, and 4 is interposed between the inner peripheral portion 2 and the outer peripheral portion 3. Corrugation (wave-shaped part), 5 is an annular mountain constituting corrugation 4 (here, “valley” is also considered as a mountain in the opposite direction and is called “mountain”), and 6 is an R in each mountain 5 described later The ridgeline of the bottom. The corrugation damper 1 can be manufactured by thermoforming using a cotton cloth or nylon fiber as a base material. It can also be manufactured by thermoforming using a polymer film such as polyimide resin as a base material, or by injection molding using a so-called engineering plastic such as ABS resin as a material.

  FIG. 2 is an enlarged cross-sectional view of the right half of FIG. As shown in the figure, the corrugation damper 1 includes peaks 5 a to 5 i as peaks 5. The intervals S between the peaks 5a to 5i are equal. As a value of the interval S, for example, 2.3 [mm] is applicable. Each of the peaks 5a to 5i exhibits the same regular undulation along the circumferential direction of the annular shape, and the phases of the undulations do not match except for the peaks 5a and 5i at the position of the cross section of FIG. Therefore, the heights h of the peaks 5a to 5i are different in the cross section of FIG. 2 except for the peaks 5a and 5i.

  FIG. 3 is an enlarged cross-sectional view of a part of FIG. As shown in the figure, the corrugation 4 includes a curved portion C having a radius R and a straight portion L between the curved portions C. That is, the vicinity of the top of each mountain 5 is constituted by the curved portion C, and the skirt portion is constituted by the straight portion L. The above-described ridge line 6 of the R edge is a boundary line between the curved portion C and the straight portion L. The radius R of the curved portion C is equal in the circumferential direction and is equal in each mountain 5. However, since there are undulations in the circumferential direction, the height of each mountain 5 changes in the circumferential direction. Further, as shown in FIG. 2, the intervals S between the peaks 5 are equal. Therefore, as shown in FIG. 1A, when viewed from above, the width of the curved portion C of each mountain 5 expressed as the width between the ridge lines 6 of the R tail also changes the height of each mountain 5. Will change accordingly.

  FIG. 4 shows how the height of each mountain 5 changes in the circumferential direction. 41 to 43 in the figure are imaginary lines representing the cross section of the mountain 5 in the state of the intermediate height, the maximum height, and the minimum height, respectively. Each mountain 5 has an undulation in the circumferential direction, and the height h of each mountain 5 changes in the vertical direction indicated by the arrow 44 as indicated by imaginary lines 41 to 43. That is, the height h of each mountain 5 gradually increases starting from the intermediate height h1, reaches the maximum height h2, gradually decreases from there, returns to the intermediate height h1, and further decreases. The one-time reciprocal change of reaching the minimum height h3 and gradually increasing from there to return to the intermediate height h1 is repeated 10 times during one round along the circumferential direction. That is, one round trip corresponds to 36 °. As values of the heights h1, h2, and h3, for example, h1 = 0.8 [mm], h2 = 1.1 [mm], and h3 = 0.5 [mm] are applicable. However, the starting point of the 10 reciprocal changes is different for each mountain 5.

  FIG. 5 is a diagram showing the starting point of 10 reciprocal changes for each mountain 5. In the same figure, each starting point is shown about the case where the corrugation damper 1 is seen from the top. In the figure, a to i are ridge lines of the peaks 5a to 5i (a sequence of the highest portions), Pa to Pi are starting points at which the mountains 5a to 5i start the 10 round trips, and 51 is each ridge line a to A broken line passing through a point having the highest height h2 of i, 52 is a dotted line passing through a point having the lowest height h3 of each ridge line a to i, and 53 is a center C of the corrugation damper 1. It is a line which shows the circumferential direction position (angular position) every 9 degrees made into the center.

  As shown in the figure, the start points Pa to Pi are sequentially arranged with an interval of 45 ° with the center C as the center. Therefore, the start points Pa and Pi are located at the same angular position with the center C as the center. Also, since one round trip corresponds to 36 ° (= 360 ° ÷ 10 round trips), as indicated by the lines 51 and 52, the same height portion of each mountain 5a to 5i extends from the mountain 5a to the mountain 5i. Sequentially shifted by 9 ° (= 45 ° -36 °), they are arranged in a spiral shape.

  FIG. 6 is a diagram of a display screen showing how the height of each mountain 5 changes. FIG. 7 is a view of FIG. 6 represented by the ridgeline 6 of the R edge. In these drawings, a state in which almost half of the corrugation damper 1 is viewed obliquely from above is shown. Thus, by changing the height of each peak 5 in the circumferential direction while sequentially shifting the phase between the peaks 5 by 9 °, the corrugation 4 is provided with hard and soft portions in a spiral shape. Yes.

  When driving the speaker using the corrugation damper 1, the inner peripheral portion 2 vibrates together with the vibration of the voice coil bobbin of the speaker. Since the outer peripheral part 3 is fixed to the speaker frame, it does not vibrate. Therefore, the vibration of the inner peripheral portion 2 is attenuated through the corrugation 4 between the inner peripheral portion 2 and the outer peripheral portion 3 and is supported by the outer peripheral portion 3. At this time, in order to improve the performance of the speaker, the corrugation damper 1 needs to hold the vibration transmitted from the voice coil to the diaphragm as accurately as possible without impairing the linearity with respect to the drive signal.

  FIG. 8 is a diagram of a display screen that displays the result of structural analysis performed by applying the force assumed when the speaker using the corrugation damper 1 is actually driven to the analysis model of the corrugation damper 1. It can be seen that the stress in the corrugation 4 is dispersed according to the 10 reciprocal height changes in the above-described peaks 5 and is dispersed in a spiral shape consisting of 10 branches. That is, it can be seen that the stress is distributed in the vicinity of the portion where the height h3 of the mountain indicated by the line 52 (FIG. 5) is low h3. That is, it can be seen that the vibration of the diaphragm can be supported by the action close to the butterfly damper.

  FIG. 9 shows the result of driving a speaker using the corrugation damper 1 and measuring the admittance for the drive current. FIG. 10 shows the result of measuring the admittance of the drive current under the same conditions using a conventional corrugation damper prepared in the same manner as the corrugation damper 1 except that the height of each corrugation peak is constant in the circumferential direction. Indicates. As shown in FIG. 10, according to the conventional corrugation damper, a large secondary resonance peak appears at 761 [Hz], whereas according to the corrugation damper 1 of the present embodiment, it is shown in FIG. As can be seen, the secondary resonance peaks are dispersed at 640 [Hz], 649 [Hz], and 693 [Hz] and appear to be small. Therefore, according to the corrugation damper 1 of this embodiment, compared with the conventional corrugation damper, it turns out that distortion can be suppressed and it can contribute to the improvement of sound quality.

  As described above, according to the present embodiment, the corrugation is provided with undulations in the circumferential direction, so that in the past, a large stress was distributed on the inner peripheral side, whereas a portion subjected to a large stress was distributed. And can be distributed to the outer peripheral portion. Therefore, the resonance peak can be separated and reduced as compared with the conventional case. Therefore, distortion can be suppressed. In addition, resistance to bending fatigue can be improved.

  In addition, the undulation angular period is constant for each mountain, and the starting point of undulation is shifted sequentially from the inner peripheral mountain to the outer peripheral mountain by a predetermined angular position at each mountain, so high stress is applied. Therefore, the diaphragm can be vibrated more smoothly by the behavior like a butterfly damper. That is, since it has the characteristics of a butterfly damper, the linearity of the amplitude can be improved as compared with the conventional corrugation damper. Further, even in the case of vibration with a large amplitude, there is no fear of breakage as in the case of a normal corrugation damper.

  Note that the present invention is not limited to the above-described embodiment, and can be implemented with appropriate modifications. For example, although not mentioned above, when the corrugation damper according to the present invention is used in a speaker having a large aperture and high input resistance, a plurality of corrugation dampers may be used. . In this case, you may make it adjust the angular position between each corrugation damper so that the direction of undulation in each corrugation damper may become the same, or it may invert. Further, as each corrugation damper, a plurality of undulation start points arranged in the same direction or in opposite directions may be used.

  1: Corrugation damper, 2: Inner periphery, 3: Outer periphery, 4: Corrugation, 5, 5a to 5i: Mountain, 6: R ridgeline, 41-43: Imaginary line representing the cross section of mountain, C: R Part, L: straight line part, ai: ridge line, Pa-Pi: start point, 51: broken line, 52: dotted line, 53: line indicating circumferential position.

Claims (6)

Have the undulating crests of each annular constituting the corrugations in the circumferential direction, the teeth
The ups and downs of each annular ridge are regularly repeated multiple times during one round, starting from a predetermined intermediate height, gradually changing the height, And a change in the height of the unit cycle of returning to the intermediate height through the minimum height in this order is repeated for a predetermined number of cycles while making a round of the annular ridge. Corrugation damper. The predetermined number of cycles is the same in each annular ridge, and the starting point of the unit cycle in each annular ridge is centered on the damper center from the annular ridge on the inner peripheral side to the annular ridge on the outer peripheral side. The corrugation damper according to claim 1 , wherein the corrugation damper is sequentially shifted by a predetermined angle. When viewed in cross section, each annular ridge is composed of a curved portion having a constant radius of curvature including the apex, and a linear skirt portion adjacent to both sides of the curved portion, and the arrangement interval between each annular ridge is as follows. The corrugation damper according to claim 1 or 2 , wherein the corrugation damper is constant, and the curvature radius of the curved portion of each annular crest is the same. A speaker comprising a plurality of corrugation dampers according to any one of claims 1 to 3 . The speaker according to claim 4 , wherein the plurality of corrugation dampers have the same undulation direction in the corrugation dampers adjacent to each other, or the undulation directions are reversed. 3. The corrugation damper according to claim 2 , wherein a plurality of the corrugation dampers have the same angular direction of the sequential shifts or are opposite to each other.