JPS5994995A - Dynamic speaker - Google Patents

Abstract

PURPOSE:To increase the secondary moment by the curve of a rib and to output a reproducing sound with high quality by providing a sectorial rib having a smooth curve while increasing the width and depth from the vicinity of a voice coil fitting of a rectangular cone diaphragm toward an outer circumference along a longitudinal side direction. CONSTITUTION:The dynamic speaker is constituted the rectangular cone diaphragm 1, a center cap 2, the voice coil 6, a frame 4 and a yoke 8. A recessed or projected sectorial rib 11 formed with a smooth curve increasing the width and depth from the vicinity of the fitting of the coil 6 of the diaphragm 6 toward the outer circumference along the longitudinal side direction is provided. The center of the coil 6 is fitted with an eccentricity from the longitudinal side direction of the diaphragm 1. The secondary moment is increased by the smooth curve of the rib 11, the folding in the long side direction is decreased, and the resonance of the diaphragm 1 is suppressed to output the reproducing sound with high quality.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an electrodynamic speaker having a rectangular cone diaphragm.

Conventional Structures and Their Problems In recent years, as sound reproduction devices have become more compact, rectangular speakers 2A-2A, which can efficiently utilize space, are increasingly being used as electrodynamic speakers.

A conventional rectangular electrodynamic speaker will be described below.

Figure 1 (-1 is a plan view of a conventional rectangular cone speaker;
The same figure (b) is the cross-sectional view taken along the line A-A. 1 is a cone diaphragm, 2 is a hemispherical dust cap attached to the center of the diaphragm, and the cone diaphragm 1 is Connected to frame 4. 6 is a voice coil, one end of which is fixed to the cone diaphragm 1, and the other end inserted into a magnetic gap formed by a yoke 8, a plate 9, and a magnet 10, and is attached to the frame 4 via a damper 6. It is being

The operation of the electrodynamic speaker configured as above will be described below. First, attach the gold thread wire 7 to the voice coil 6.
Apply the audio electrical signal via.

A force proportional to the amplitude of the input signal is applied to the voice coil 6 inserted into the magnetic gap in the vertical direction (in FIG. 1) according to Faraday's left-hand rule.

Therefore, the voice coil 6 vibrates, driving the cone diaphragm 1 and the dust cap 2, and reproducing the acoustic signal. FIG. 2 shows an example of the frequency characteristics of the reproduced signal. Furthermore, Figure 3 (
3(a) shows the vibration mode at the first resonance frequency f1 of the diaphragm, and FIG. 3(b) shows the higher-order resonance vibration mode. 1st
In the next resonance, splitting vibration occurs in the long side direction, and as the order becomes higher, the splitting becomes finer, and splitting also occurs in the short side direction. Therefore, a large peak is shown at frequency f1 in FIG. 2, and peak dips are repeated at frequencies of 11 or more.

The conventional configuration has a problem in that as the ratio of the long side to the short side of the rectangular cone speaker increases, peak dips due to split resonance are more likely to occur, resulting in deterioration of frequency characteristics.

Purpose of the Invention The present invention solves the above conventional problems, and provides an electrodynamic speaker having a rectangular cone diaphragm that suppresses resonance of the rectangular cone diaphragm and flattens peaks and dips in frequency characteristics. The purpose is to provide.

Structure of the Invention The present invention provides a rectangular cone diaphragm whose width gradually increases from the vicinity of the voice coil mounting portion toward the outer periphery along the long side,
This is an electrodynamic speaker that uses a rectangular cone diaphragm that has a concave or convex fan-shaped lip that is composed of a smooth curved surface whose depth increases with the width.By making the fan-shaped rib shape as described above, This suppresses primary resonance in the long side direction and high-order divided resonance in the short side direction, making the frequency characteristics flatter and enabling high quality sound reproduction.

DESCRIPTION OF EMBODIMENTS FIG. 4(a) is a plan view of an electrodynamic speaker equipped with a rectangular cone diaphragm according to an embodiment of the present invention, and FIG. 4(b) is a cross-sectional view taken along the line B-B. It is. 1 is a cone diaphragm, 2 is a dust cap, 3 is an edge, 4 is a frame,
5 is a damper, 6 is a voice coil, 7 is a gold thread wire, 8 is a yoke, 9 is a plate, and 10 is a magnet, which are the same as those of the conventional example. Reference numeral 11 denotes a concave lip provided on the cone diaphragm 1, and as shown in FIG. Further, as shown in FIG. 6(b), the depth of the lip gradually becomes deeper. Further, as shown in FIG. 6(C), which is a sectional view taken along line C-C, the cross section of the lip is a smooth curve. As described above, the concave fan-shaped lip 11 having a smooth curved surface is formed on the cone diaphragm.

The operation of the electrodynamic speaker of this embodiment configured as described above will be described below. When an audio electrical signal is applied to the voice coil 6 as in the conventional example, the voice coil 6 receives the force, causing the cone diaphragm and the dust camp to vibrate, thereby reproducing the acoustic signal. According to this embodiment, since the lip 11 is formed in the long side direction of the cone diaphragm, it is possible to suppress the peak dip due to the first resonance, as shown by the solid line P in FIG. 6. Furthermore, since this lip 11 has a fan shape that widens from the center toward the outer periphery, it is possible to alleviate the split resonance in the short side direction in higher-order modes.

In addition, by making the lip shape a smooth curved surface, lip 11
Stress concentration can be avoided, and the body 6 can be made structurally stronger. The broken line in Fig. 6 is for the conventional example shown in Fig. 2, and as is clear from the comparison, this example can suppress split resonance in both the first and higher orders, and has a flatter structure than the conventional example. Frequency characteristics can be achieved. Therefore, it is possible to improve the sound quality particularly from the mid-range to the high-range of the reproduced sound.

Furthermore, FIG. 7 is a plan view showing an effective structure for suppressing vibrations in the long side direction of the cone diaphragm. The center S is eccentrically attached. In this configuration, the lengths of the left and right sides of the center S differ between the long sides, making it difficult for the cone diaphragm to resonate, and is particularly effective in suppressing resonance in low-order modes.

Effects of the Invention The present invention provides a rectangular cone diaphragm with a fan-shaped lip that increases in width and depth from the vicinity of the voice coil attachment part along the long side toward the outer periphery and is composed of a smooth curve. The second moment of area becomes larger due to the shape effect of the groove, making it difficult to bend in the long side direction, which suppresses the resonance of the cone diaphragm and suppresses peaks and dips in the frequency characteristics, resulting in high quality reproduced sound. It is possible to obtain Furthermore, the entire cone diaphragm can be reinforced, and since split vibrations are damped, there is no need to increase the thickness of the diaphragm, making it possible to reduce the thickness of the diaphragm and improve efficiency. It has excellent effects.

[Brief explanation of the drawing]

FIG. 1(a) is a plan view of a conventional rectangular electrodynamic speaker.
The same figure (bl is a cross-sectional view taken along the line A-A, FIG. 2 is a sound pressure frequency characteristic diagram of a conventional speaker, and FIG. 3 (a). fb) is a resonance mode of a conventional cone diaphragm. Diagrams, Figure 4 (,) is a cross-sectional view of an electrodynamic type according to an embodiment of the present invention, Figure (C) is a cross-sectional view of the C-C @ cross-sectional view, and Figure 6 is a sound diagram of an embodiment of the present invention. FIG. 7 is a plan view of another embodiment. 1... Cone diaphragm, 2... Center cap, 6... Voice coil, 11...
...Rep. Name of agent: Patent attorney Toshio Nakao and 1 other person57
1 Fig. 3 Cα2 tb - Fig. 4 Fig. 6 Fig. 5 Cα] (b) -1-Li5v-curse (C)

Claims (2)

[Claims] (1) A concave or convex shape consisting of a smooth curved surface where the width gradually increases from near the voice coil attachment part of a rectangular cone diaphragm toward the outer periphery along the long side, and the depth also increases as the width increases. An electrodynamic speaker characterized by being equipped with a fan diagnostic volume. (2) The electrodynamic speaker according to claim 1, wherein the center of the voice coil is eccentrically attached to the center of the rectangular cone diaphragm in the longitudinal direction.