Patent ID: 8919748
Filing Date: 2014-12-30
Classification: F16F,H02K,Y10T

Abstract:
1. An active antivibration device, comprising: a main body formed by a base body and a housing which are combined in a unified manner; a mobile element which is elastically supported inside the main body and movable in an axial direction of the main body; and a coil which is disposed inside the main body and fixed to the main body, wherein the mobile element includes a mobile axis body whose respective ends in the axial direction of the main body are elastically supported by a first flat spring and a second flat spring, and a first yoke, a permanent magnet and a second yoke which are held by the mobile axis body and disposed successively along an axial direction of the mobile axis body, wherein the first flat spring whose outer circumferential portion is fixed to an inside of the base body is disposed on one side of the main body in the axial direction of the main body, and the second flat spring whose outer circumferential portion is fixed to a ceiling surface of the housing is disposed on the other side of the main body in the axial direction of the main body, where the outer circumferential portion of the second flat spring is not fixed to an outer circumferential side of the mobile element, wherein the permanent magnet is magnetized in the axial direction of the mobile axis body and disposed between the first yoke and the second yoke, and wherein an elastic member and a locking member are disposed on one side of the mobile axis body in the axial direction between the first flat spring and the second flat spring, the elastic member pushing the first yoke and the permanent magnet toward the other side of the mobile axis body in the axial direction of the mobile axis body, the locking member being engaged with an outer circumferential surface of the mobile axis body; wherein a locking portion of the mobile axis body has a larger diameter in comparison with a portion of the mobile axis body holding the first yoke and permanent magnet disposed on the other side of the mobile axis body in the axial direction of the mobile axis body; and wherein in the mobile element, the first yoke, the permanent magnet and second yoke are closely arranged in this order along the axial direction of the mobile axis body from the one side that is a side of the elastic member to the other side that is a side of the locking portion.