JPH0252919B2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a vibration absorbing device.

Conventionally, methods using mechanical loss are well known for absorbing vibrations.

When using mechanical loss, it is mainly composed of a vibrating part, a loss generating part, and a support part, and the vibration energy of the vibrating part is converted into thermal energy in the loss generating part, and the rest is transmitted to the support part. When converting into thermal energy, it is difficult to find a material whose vibration damping characteristics are uniform from low to high frequencies in the mechanical loss generating part, so the vibration energy is also transmitted to the support part, and the vibration of the support part is reduced by the area of the equipment, etc. Even if the vibration energy of the supporting part is small because the vibration is propagated to a wide casing part, the vibration radiated from the wide area can be heard as noise.
Furthermore, in the case of mechanically absorbing vibrations, it is difficult to maintain loss by applying tension beyond a certain level using a viscoelastic material, as this causes deformation of the viscoelastic material. Furthermore, when a viscoelastic material is used, it has the disadvantage that its loss characteristics change when it is compressed and expanded by vibration energy.

The present invention was made in order to solve the drawbacks of the mechanical loss adding method, and consists of a vibrating part, a conductor connected to the vibrating part, and a pair of opposite poles that form a magnetic field parallel to the conductor. The conductor of the vibrating part is supported by the magnetic member through a spacer made of an elastic member, and the vibration of the vibrating part is prevented from being directly transmitted to the support part and absorbed, and the vibration of the vibrating part is absorbed by the conductor. The conductor vibrates in a parallel magnetic field, causing the conductor to cut off the magnetic flux and cause an eddy current to flow through the conductor.The eddy current is damped by the magnetic field in a direction that cancels out the vibration of the conductor. The present invention provides a device that absorbs vibrations.

This will be explained in detail below using the drawings.

FIG. 1 shows a vibration absorbing device of the present invention.

A magnetic circuit of a speaker is constituted by a center pole 5 and a top plate 6 with a magnet 4 in between, a voice coil 3 is provided in an air gap 7, and a voice coil bobbin 2 is fixed to a diaphragm 1. Net-like top cover 9
The structure is such that the diaphragm 1 is protected by the diaphragm 1 and the speaker is attached to the frame 10.

Input terminals 11a and 11b provided on the frame 10
The speaker is driven by this. At the edge part of the diaphragm 1, there are magnets 12a and 12 on both sides of the edge 14.
b. The magnets 12a and 12b vibrately support the edge 14 by a spacer 13 made of an elastic material such as paper or rubber. A conductive material is formed on the edge 14, and magnets 12a and 12b are arranged with their magnetic poles facing each other so that a parallel magnetic field is generated with respect to the conductive material. When an input is applied from the input terminals 11a and 11b, a current flows through the voice coil 3, driving the bobbin 2, and the bobbin 2 vibrates together with the diaphragm 1. The vibration energy of the diaphragm 1 is absorbed mechanically by the bending vibration of the edges, and the edge of a conductive material placed parallel to the magnetic field cuts the magnetic flux due to vibration and generates an eddy current, and the energy is absorbed electromagnetically. . On the other hand, expansion and contraction vibration inside the diaphragm, such as resonance vibration due to the shape of the diaphragm, also produces an electromagnetic energy absorption effect due to a change in the volume of the conductor.

By providing a conductor parallel to the magnetic field in a parallel magnetic field, the conductor can be made thin, and even when connected to the vibrating part, a vibration absorbing device can be constructed without significantly increasing the weight of the vibrating part.

As described above, according to the present invention, the conductive part of the new copper plate is supported by being sandwiched between magnetic members having the same poles facing each other via a spacer made of an elastic member, thereby preventing and absorbing vibrations transmitted to the support part by the elastic members. At the same time, since the vibration of the diaphragm is damped by electromagnetic braking by the conductor, the transmission of vibration to the support portion can be reduced.

[Brief explanation of drawings]

FIG. 1 is a partially sectional view showing an embodiment of the present invention. 1 is the diaphragm, 2 is the bobbin, 3 is the voice coil,
4 is a magnet, 5 is a center pole, 6 is a top plate, 7 is an air gap, 9 is a top cover, 10 is a frame, 11 is an input terminal, 12 is a magnet, 13 is a spacer, 14 is an edge, and 17 is a conductive part. .

Claims (1)

[Claims] 1. A diaphragm with a conductor formed on the diaphragm, a magnetic member with the same poles facing each other to form a magnetic field parallel to the conductor surface of the diaphragm, and a diaphragm between the magnetic members. and a spacer made of an elastic member that is held at a distance from the diaphragm, and the conductor part of the diaphragm is supported by the magnetic member via the spacer, and the elastic member prevents the vibration of the diaphragm from being transmitted to the support part. A vibration absorbing device characterized in that the vibration of the diaphragm is transmitted to a conductor, the conductor vibrates in a parallel magnetic field, an eddy current is generated in the conductor, and the vibration energy of the diaphragm is absorbed by electromagnetic braking by the magnetic field. 2. The vibration absorbing device according to claim 1, characterized in that a conductor is provided at the edge of the diaphragm of the speaker, and vibration energy is absorbed by electromagnetic braking by a parallel magnetic field at the edge supported through a spacer. .