CN209949404U

CN209949404U - Hidden magnet structure for equal magnetic loudspeaker

Info

Publication number: CN209949404U
Application number: CN201822115876.7U
Authority: CN
Inventors: 杈逛豢; 边仿
Original assignee: Chief Technology (kunshan) Co Ltd
Current assignee: Kunshan Haifeiman Technology Group Co ltd
Priority date: 2018-12-17
Filing date: 2018-12-17
Publication date: 2020-01-14
Anticipated expiration: 2028-12-17

Abstract

The utility model relates to a hidden magnet structure for a constant magnetic loudspeaker, which comprises a magnet array which is formed by a plurality of permanent magnets arranged at equal intervals along one direction and is arranged corresponding to a vibrating diaphragm coil area of the constant magnetic loudspeaker; the permanent magnets comprise bottoms, tops and waists for connecting the tops and the bottoms, the bottoms are planes, the magnetic field directions of the permanent magnets are perpendicular to the bottoms, and the bottoms of the permanent magnets face the diaphragm coil in a coplanar manner; the maximum size of the permanent magnet along the direction parallel to the plane of the diaphragm coil is less than or equal to c/2 pi f_minWhere c is the speed of sound wave, f_minBeing equal-magnet loudspeakersA minimum output audio; the sum of the areas of the bottoms of the permanent magnets is more than or equal to 40% of the area of the diaphragm coil area and less than or equal to 60% of the area of the diaphragm coil area. The utility model discloses can effectively improve the degree of reduction of low frequency sound wave to and improve the sound field of speaker, improve the space stereovision and the resolving power of speaker.

Description

Hidden magnet structure for equal magnetic loudspeaker

Technical Field

The utility model relates to a speaker technical field especially relates to a stealthy magnet structure for waiting magnetic loudspeaker.

Background

The driving type of the electroacoustic speakers can be broadly classified into an equal magnetic speaker, a moving coil speaker, a piezoelectric speaker and an electrostatic speaker.

The isomagnetic loudspeaker can be divided into a push-pull type loudspeaker and a single-end type loudspeaker from the magnet subsection structure. The iso-magnetic speaker combines the advantages of both the moving coil speaker and the electrostatic speaker, has better performance in low frequencies than the electrostatic speaker, and is also stronger in high frequencies than the moving coil speaker. The structure of the transducer at the core is usually that a flexible diaphragm is fixed on a hollow frame, one side (single-end type) or two sides of the diaphragm are respectively provided with (push-pull type) magnet yokes, a plurality of strip-shaped or round permanent magnets (mostly adopting NdFeB magnets with the brand number of N50 and above) are fixed on the magnet yokes, and coils are arranged at the positions opposite to the magnetic pole surfaces of the permanent magnets on the diaphragm. The current flowing inside the coil is orthogonal to the magnetic field generated by the permanent magnet, so that by inputting an alternating current into the coil, the coil generates a force according to faraday's law, under which the diaphragm vibrates in the vertical direction, and the alternating current signal is converted into an acoustic signal.

The permanent magnet of the single-end type equal magnetic loudspeaker is arranged on one side of the vibrating diaphragm, and the magnetic field intensity or the magnetic field uniformity is influenced. Particularly in terms of magnetic field uniformity, the magnetic field intensity generated by the permanent magnet can be rapidly attenuated along with the distance increase (inversely proportional to the cubic distance), so that when the diaphragm vibrates in the vertical direction and is far away from the permanent magnet, the received force can be rapidly attenuated, and the response speed is reduced.

The permanent magnets of push-pull type equal magnetic loudspeakers, which are arranged in the transmission path of sound waves from the diaphragm to the listener, cause a certain attenuation of the sound waves. Particularly, the barrier is more obvious to the low-frequency sound wave, and the reduction degree of the sound wave is influenced. Moreover, the cross section of the existing permanent magnet is rectangular regardless of the shape of a circular ring or a strip, so that multiple reflection of sound waves between the permanent magnets can cause energy loss, and even coherent travel standing waves can be generated. The user feels the sound field disorder and the spatial sense of the sound is degraded.

SUMMERY OF THE UTILITY MODEL

The utility model aims at the structural shortcoming of prior art, provide a stealthy magnet structure for waiting magnetic loudspeaker, solve the poor and chaotic problem of sound field of low frequency sound effect in waiting magnetic loudspeaker.

The embodiment of the utility model provides an invisible magnet structure for an equal-magnetism type loudspeaker, which comprises a magnet array which is formed by a plurality of permanent magnets arranged at equal intervals along any direction and is arranged corresponding to a vibrating diaphragm coil area of the equal-magnetism type loudspeaker; the permanent magnets comprise bottoms, tops and waists for connecting the tops and the bottoms, the bottoms are planes, the magnetic field directions of the permanent magnets are perpendicular to the bottoms, and the bottoms of the permanent magnets are coplanar and face the diaphragm coil; the maximum size of the permanent magnet along the direction parallel to the plane of the diaphragm coil is less than or equal to c/2 pi f_minWhere c is the speed of sound wave, f_minMinimum output audio for equal magnet speakers; and the sum of the areas of the bottoms of the permanent magnets is more than or equal to 40% of the area of the diaphragm coil area and less than or equal to 60% of the area of the diaphragm coil area.

In a preferred embodiment, L is the maximum size of the permanent magnet along the direction parallel to the plane of the diaphragm coil, and L is more than or equal to 2.4mm and less than or equal to 10 m.

In a preferred embodiment, H is the maximum size of the permanent magnet along the direction vertical to the coil of the diaphragm, and H is more than or equal to 5mm and less than or equal to 20 m.

Compared with the prior art, the utility model discloses the beneficial effect of embodiment is: the reduction degree of low-frequency sound waves is improved by adjusting the space size of the permanent magnet; by optimizing the section shape of the permanent magnet, the interference of the permanent magnet to sound in the existing equal-magnetic loudspeaker is reduced on the premise of ensuring the magnetic field intensity, the sound field of the loudspeaker is effectively improved, and the spatial layering sense and the analytic force of the loudspeaker are improved.

Drawings

The above features and advantages of the present invention will become more apparent and readily appreciated from the following description of the exemplary embodiments thereof taken in conjunction with the accompanying drawings.

Fig. 1 is a schematic structural diagram of an equal magnetic speaker according to embodiment 1 of the present invention.

Fig. 2 is an array schematic diagram of a hidden magnet structure for an equal magnetic speaker according to embodiment 1 of the present invention.

Fig. 3 is a schematic bottom structure diagram of a permanent magnet of a magnet structure for an equal magnetic speaker according to embodiment 1 of the present invention.

Detailed Description

The invention will be described in further detail below with reference to the accompanying drawings so as to facilitate understanding by those skilled in the art:

example 1:

referring to fig. 1, fig. 1 shows an isometric speaker. The magnetic loudspeaker comprises a diaphragm 1 with a periphery fixed by a frame 2, and a coil on the diaphragm 1 is electrically connected with a signal wire. Yokes are respectively arranged on two sides of the diaphragm 1, and each yoke comprises an array formed by a plurality of permanent magnets 3 arranged in parallel to the diaphragm 1. The permanent magnet array is arranged corresponding to the coil area on the diaphragm 1 to ensure the magnetic field intensity on the diaphragm 1 and improve the energy conversion efficiency. Referring to fig. 2, fig. 2 shows a permanent magnet array of the hidden magnet structure for an equal magnetic speaker according to the present embodiment, in which permanent magnets 3 are arranged at equal intervals in any direction. The permanent magnets 3 in the magnetic yokes on the two sides of the diaphragm 1 have the same size, and the distances between the permanent magnets 3 can be the same, namely, a symmetrical structure is adopted. The spacing in the different directions may be equal or different, for example, the spacing W1 in the first direction is different from the spacing W2 in the second direction. The coil on the yoke and diaphragm is omitted from the figure.

The permanent magnet 3 has rotational symmetry in a direction perpendicular to the diaphragm coil and comprises a bottom part 4, a top part 5 and a waist part 6 connecting the top part 5 and the bottom part 4. The base 4 is planar and the bases 4 of the plurality of permanent magnets 3 in the array are coplanar and face the coils of the diaphragm 1. Referring to fig. 2, fig. 2 shows a permanent magnet structure of the hidden magnet structure for the isomagnetic speaker of the present embodiment, and a bottom 4 of the permanent magnet 3 is in a regular polygon shape, a circular shape, an oval shape or a rectangular shape. In addition, the bottom 4 also serves as a magnetic pole of the permanent magnet 3, so that the magnetic field direction of the permanent magnet 3 is perpendicular to the bottom 4 and further perpendicular to the coil on the diaphragm 1. An arc chamfer angle can be arranged between the waist part 6 and the bottom part 4. The permanent magnet 3 is a neodymium iron boron magnet, and the higher the magnetic field intensity provided by the permanent magnet 3 is, the higher the ring energy efficiency of the loudspeaker is. The physical properties of the ndfeb magnet suitable for use in a loudspeaker are shown in the following table:

from the above table, it can be seen that according to the performance parameters of the ndfeb magnet, the grade of the ndfeb magnet used in the speaker is usually up to N52.

The maximum size of the permanent magnet 3 along the direction parallel to the plane of the diaphragm coil is less than or equal to c/2 pi f_minWhere c is the acoustic velocity (typically 340m/s), f_minThe minimum output audio frequency of the equal-magnet loudspeaker. When the size of the permanent magnet 3 meets the above conditions, the low-frequency sound wave generated by the diaphragm 1 is subjected to sound wave diffraction at the position of the permanent magnet array, bypasses the permanent magnet 3 in the array and forms a more complete sound field behind the permanent magnet, and the sound effect of the low-frequency sound wave of the equal-magnet loudspeaker is improved. The audio frequency range of the loudspeaker output is typically 20Hz-20KHz, and the maximum dimension of the permanent magnet 3 perpendicular to the direction of sound propagation (parallel to the plane of the diaphragm 1) is selected in the range of 2.7mm-2.7 m. To accommodate a wider range of applications, the dimensions of the permanent magnet 3 are selected in the range of 2.4mm-10m for infrasonic and ultrasonic range sound output.

For a speaker outputting audible audio, the weight of the speaker needs to be controlled to improve the comfort of the user, and therefore the volume of the permanent magnet 3 should be adapted to the light usage requirement of the speaker. Meanwhile, in order to improve the electroacoustic transduction efficiency, ensure the magnetic field intensity and ensure the integrity and better yield of the permanent magnet in the production process, the thickness of the permanent magnet 3 should not be lower than 0.5 cm. When the permanent magnet 3 is made of neodymium iron boron materials, the size is also influenced by the magnetism of the materials. The magnetic conductivity of the neodymium iron boron magnet is poor, the magnetic field intensity is rapidly attenuated along with the increase of the distance, and the magnetic field intensity is limited after the thickness of the permanent magnet 3 is larger than 7 cm. Further preferably, the thickness of the permanent magnet 3 is preferably 1cm-5m under the premise of controlling the quality of the loudspeaker.

Except the size of the permanent magnet 3 perpendicular to the sound transmission direction, the distance between the permanent magnets 3 in the permanent magnet array has an influence on the transmission efficiency of audio, when the distance is too small, the transmission energy consumption of sound waves can be influenced, when the distance is too large, the magnetic field intensity can be increased, therefore, the size is selected for the distance between the preferable permanent magnets 3, the sum of the areas of the bottoms 4 of the permanent magnets 3 in the permanent magnet array is more than or equal to 40% of the area of the vibrating diaphragm coil area, and is less than or equal to 60% of the area of the vibrating diaphragm coil area, so that the sound wave.

The above embodiments are intended to illustrate the present invention and the embodiments in detail, but it can be understood by those skilled in the art that the above embodiments of the present invention are only one of the preferred embodiments of the present invention, and for space limitation, all embodiments can not be listed here one by one, and any implementation that can embody the technical solution of the present invention is within the protection scope of the present invention.

It should be noted that the above is a detailed description of the present invention, and it should not be considered that the present invention is limited to the specific embodiments, and those skilled in the art can make various modifications and variations on the above embodiments without departing from the scope of the present invention.

Claims

1. A stealthy magnet structure for isomagnetic formula speaker which characterized in that: the permanent magnet array is formed by arranging a plurality of permanent magnets at equal intervals along any direction and is arranged corresponding to a diaphragm coil area of the equal magnetic loudspeaker;

the permanent magnets comprise bottoms, tops and waists connecting the tops and the bottoms, the bottoms are planes, the magnetic field directions of the permanent magnets are perpendicular to the bottoms, and the bottoms of the permanent magnets are coplanar and face the diaphragm coil;

the maximum size of the permanent magnets along the direction parallel to the plane of the diaphragm coil is less than or equal to c/2 pi f_minWhere c is the speed of sound wave, f_minA minimum output audio frequency for the equal magnetic loudspeaker; and the number of the first and second groups,

the sum of the areas of the bottoms of the permanent magnets is more than or equal to 40% of the area of the vibrating diaphragm coil area and less than or equal to 60% of the area of the vibrating diaphragm coil area; the thickness of the permanent magnets is 1cm-5m, the maximum size range of the permanent magnets perpendicular to the sound transmission direction is 2.4mm and L which is not less than 10m, and L is the maximum size of the permanent magnets along the direction parallel to the plane of the diaphragm coil.