Reciprocating vibration generator
A reciprocating vibration generator of a structure enabling force of a reciprocating vibrating body striking a coil to be absorbed by magnetic fluid even if an external impact force is applied, that is, a reciprocating vibration generator provided in a case body 100 with an upper plate spring 40 and a lower plate spring 50 for supporting a ring-shaped weight 20 having a ring-shaped permanent magnet 30 comprised of a combination of semi-ring-shaped permanent magnets 30 R, 30 L at its inner circumference side so as to be able to reciprocally vibrate in a vertical direction and a cylindrical excitation coil 60 passing through the inside of the ring-shaped permanent magnet 30 in the vertical direction and generating a reciprocating vibrating magnetic field, wherein the semi-ring-shaped permanent magnets 30 R, 30 L are magnetized in a direction spanning the inner circumferential surface and outer circumferential surface, the inner circumferential surface and top and bottom end faces of the semi-ring-shaped permanent magnet 30 R, 30 L are covered by magnetic fluid F, and a gap between the inner circumferential surface and the outer circumferential surface of the excitation coil 60 is filled with magnetic fluid F.
1. A reciprocating vibration generator provided in a case with an elastic member for supporting a ring-shaped weight having a ring-shaped permanent magnet at its inner circumference side to be able to reciprocate in the vertical direction and a cylindrical excitation coil passing through the inside of the ring-shaped permanent magnet in the vertical direction and generating a reciprocating vibrating magnetic field,
wherein the ring-shaped permanent magnet is magnetized in a direction spanning that inner circumferential surface and outer circumferential surface, the inner circumferential surface and top and bottom end faces of the ring-shaped permanent magnet are magnetically covered by magnetic fluid, and a gap between the inner circumferential surface and the outer circumferential surface of the excitation coil is filled with magnetic fluid.
2. A reciprocating vibration generator as set forth in claim 1 , wherein said ring-shaped permanent magnet is comprised of a pair of semi-ring-shaped permanent magnets fit in the inner circumference side of said ring-shaped weight with the same magnetic poles facing each other.
3. A reciprocating vibration generator as set forth in claim 2 , wherein said semi-ring-shaped permanent magnets are magnetized in parallel.
4. A reciprocating vibration generator as set forth in claim 1 , wherein said elastic member has an upper plate spring connecting an end of an outer circumference side elastic piece to a top end face of said ring-shaped weight and a lower plate spring connecting an end of an outer circumference side elastic piece to a bottom end face of said ring-shaped weight, said case has an end plate fastening an inner circumference side of said lower plate spring, and said excitation coil is carried on said end plate and has a striking member made of a magnetic material passing through the inside of said excitation coil, having one end passing through a center part of said upper plate spring, having the other end passing through a hole of said lower plate spring, and striking against said end plate.
5. A reciprocating vibration generator as set forth in claim 1 , wherein said elastic member has a lower plate spring connecting an end of an outer circumference side elastic piece to a bottom end face of said ring-shaped weight, said case has a bottom plate part to which an inner circumference side of said lower plate spring is fastened, and said excitation coil stands up from an end plate made of a magnetic material closing said case and has a striking member made of a magnetic material fit inside said excitation coil, having one end striking against a center part of the end plate, and having the other end striking against said lower plate spring.