Vibration generating apparatus

1. A vibration generating apparatus comprising:

a bracket having a circular plate shape;

a vibration member having a lower edge portion of a central portion fixed to the bracket and having a closed curved line shape;

a piezoelectric element fixed to a lower surface of the vibration member among inner surfaces of the vibration member and deformed when power is applied thereto; and

a mass body fixed to the inner surfaces of the vibration member and disposed to face the piezoelectric element, wherein the vibration member includes:

a first fixed portion fixed to an upper surface of the bracket;

first and second piezoelectric element installation portions extended from the first fixed portion in an outer diameter direction;

first and second displacement direction changing portions extended upwardly from the first and second piezoelectric element installation portions, respectively;

first and second deformation amplifying portions extended from the first and second displacement direction changing portions in an inner diameter direction, respectively; and

a second fixed portion connected to the first and second deformation amplifying portions and having the mass body mounted thereon.

2. The vibration generating apparatus of claim 1 , wherein the piezoelectric element is seated on upper surfaces of the first and second piezoelectric element installation portions and is installed in the vibration member so that both end surfaces thereof are supported by inner surfaces of the first and second displacement direction changing portions.

3. The vibration generating apparatus of claim 2 , wherein the piezoelectric element has a rectangular parallelepiped shape.

4. The vibration generating apparatus of claim 1 , wherein a central portion of the mass body is fixed to a lower surface of the second fixed portion.

5. The vibration generating apparatus of claim 1 , wherein the mass body includes protrusion portions protruding in the outer diameter direction and is roughly coin shaped.

6. The vibration generating apparatus of claim 5 , wherein the mass body has a piezoelectric element insertion groove formed in a lower surface thereof so as to prevent contact with the piezoelectric element.

7. The vibration generating apparatus of claim 1 , further comprising a case attached to the bracket and having an internal space.

8. The vibration generating apparatus of claim 7 , further comprising a circuit board having one end exposed to the outside of the case through a groove formed in the case and connected to the piezoelectric element.

9. A vibration generating apparatus comprising:

a case having an internal space;

a bracket attached to a lower edge portion of the case;

a vibration member having a lower edge portion of a central portion fixed to the bracket and having a closed curved line shape;

a piezoelectric element fixed to a lower surface of the vibration member among inner surfaces of the vibration member and deformed when power is applied thereto;

a mass body fixed to the inner surfaces of the vibration member to be disposed to face the piezoelectric element and

having a shape corresponding to that of the case; and a circuit board having one end exposed to the outside of the case through a groove formed in the case and connected to the piezoelectric element, wherein the vibration member includes:

a first fixed portion fixed to an upper surface of the bracket;

first and second piezoelectric element installation portions extended from the first fixed portion in an outer diameter direction;

first and second displacement direction changing portions extended upwardly from the first and second piezoelectric element installation portions, respectively;

first and second deformation amplifying portions extended from the first and second displacement direction changing portions in an inner diameter direction, respectively; and

a second fixed portion connected to the first and second deformation amplifying portions and having the mass body mounted thereon.