Impedance devices and systems for simulating impact of head on vibration of vibration unit
The present disclosure provides an impedance device and a system for simulating an impact of a head on a vibration of a vibration unit. The impedance device may include a mass part, an elastic part, and a fixing part. The mass part is connected to the fixing part through the elastic part. The fixing part is a hollow structure, the fixing part includes an opening. The elastic part is located at the opening and is connected to the fixing part. The elastic part forms a cavity with the fixing part. An elastic coefficient of the elastic part of a vibration direction in which the mass part vibrates relative to the fixing part in a range of 600 N/m~5000 N/m.
1 . An impedance device for simulating an impact of a head on a vibration of a vibration unit, comprising:
a mass part, an elastic part and a fixing part, the mass part being connected to the fixing part through the elastic part, wherein the fixing part is a hollow structure, the fixing part includes an opening, the elastic part is located at the opening and is connected to the fixing part, the elastic part forms a cavity with the fixing part, and an elastic coefficient of the elastic part in a vibration direction in which the mass part vibrates relative to the fixing part is in a range of 600 N/m~5000 N/m.
2 . The impedance device of claim 1 , wherein at least one hole is set on the fixing part, the at least one hole is covered with an acoustic gauze, and the acoustic gauze enables the air inside the cavity to communicate with the air outside the cavity and provides a damping.
3 . The impedance device of claim 2 , wherein a total area of the at least one holes occupies 10% to 90% of an area of a side wall of the fixing part where the at least one holes is located, a volume of the cavity is not more than 1000 cm 3 , and an acoustic resistance of the acoustic gauze is in a range of 500 Rayl to 1600 Rayl.
4 . The impedance device of claim 1 , wherein the elastic part includes a reed structure, including a hollow area, and the hollow area enables the air inside the cavity to communicate with the air outside the cavity.
5 . The impedance device of claim 4 , wherein the hollow area is covered with an acoustic gauze, the acoustic gauze enables the air inside the cavity to communicate with the air outside the cavity, and the acoustic gauze provides the damping.
6 . The impedance device of claim 1 , wherein the elastic part includes a membranous structure connected to the fixing part through a peripheral side of the membranous structure.
7 . The impedance device of claim 6 , wherein one or more holes are set on the membranous structure, the one or more holes are covered with an acoustic gauze, and the acoustic gauze enables the air inside the cavity to communicate with the air outside the cavity and provides a damping.
8 . The impedance device of claim 1 , wherein a magnetic circuit structure is provided between the elastic part and the fixing part, the magnetic circuit structure has a magnetic gap, and a metal sheet extends from the mass part or the elastic part and protrudes into the magnetic gap.
9 . The impedance device of claim 8 , wherein along the vibration direction of the mass part relative to the fixing part, a projected area of the metal sheet on the magnetic circuit structure is in a range of 25 mm 2 ~400 mm 2 .
10 . The impedance device of claim 8 , wherein the magnetic circuit structure includes a first magnet and a second magnet arranged at intervals in a groove, one pole of the first magnet and one pole of the second magnet are opposite to each other to form the magnetic gap.
11 . The impedance device of claim 10 , wherein the other pole of the first magnet and the other pole of the second magnet are connected to the fixing part.
12 . The impedance device of claim 8 , wherein the magnetic circuit structure and the metal sheet are a damping structure of the impedance device configured to provide a damping for movement of the mass part.
13 . The impedance device of claim 1 , wherein the cavity is filled with a flexible structure, and the flexible structure is in contact with the elastic part and the fixing part respectively.
14 . The impedance device of claim 13 , wherein the flexible structure is porous.
15 . The impedance device of claim 1 , wherein the impedance device includes a damping structure, the damping structure is located on a side of the mass part away from the elastic part, and is spaced apart from the mass part.
16 . The impedance device of claim 1 , when an external force acts on the elastic part, the impedance device provides a mechanical impedance in a range of 6 dB~50 dB, wherein, the external force is in the same direction as the vibration direction of the mass part relative to the fixing part, and the external force is in a range of 0.05 N~3.5 N.
17 . The impedance device of claim 1 , wherein a mass of the mass part is adjusted in a range of 0.5 g~5 g.
18 . The impedance device of claim 1 , wherein the elastic part is a membranous structure, and the elastic part connects with a side wall of the fixing part through its peripheral side to form a closed cavity.
19 . The impedance device of claim 1 , wherein a damping structure is provided on the elastic part, the damping structure provides a damping for a vibration of the elastic part, and the damping structure is made of a flexible material.