Piezoelectric relay with a piezoelectric longitudinal effect actuator

Claim 1

A piezoelectric relay comprising: a base frame made of synthetic resin and having a base plate; a first block having a first arm and a second arm extending in parallel with each other, and a connection channel fixed on said base plate for inter-connecting said arms; a second block engaged with said connection channel of said first block; an elongated piezoelectric actuator having one end portion abutting against said second block and extending in the axial direction thereof, said actuator having a driving chip on its other end portion thereof, said actuator being arranged between said first arm and said second arm of said first block, and being expansion-displaced in said axial direction in response to applied voltage; displacement magnifying means having an input section for receiving as an input the displacement from said actuator, and a first-stage magnifying section and a second-stage magnifying section for sequentially magnifying the output displacement of said input section; said input section of said displacement magnifying means comprising a first resilient lever having one end which is fixed to said first arm of said first block, a first non-resilient lever which is fixed at one end portion thereof to the other end portion of said resilient lever, said first non-resilient lever abutting against said driving chip of said actuator at substantially a center portion thereof; said first-stage magnifying section comprising a second resilient lever which is fixed at one end portion thereof to the other end portion of said first non-resilient lever, a third resilient lever which is fixed at one end portion thereof to said second arm of said first block, a second non-resilient lever which is fixed at one end portion thereof to the other end portion of said second and third resilient levers; said second-stage magnifying section comprising a fourth resilient lever which is fixed at one end portion thereof to the other end portion of said second non-resilient lever, a fifth resilient lever which is fixed at one end portion thereof to the other end portion of said second arm, said second arm of said first block having a stopper which abuts on at least one of said fourth and fifth resilient levers of said magnifying means, a third non-resilient lever which is fixed at one end portion thereof to the other end portion of said fourth and fifth resilient levers; and a movable resilient member driven by said magnifying means to connect between a movable contact and a stationary contact; wherein Δl 2 =Δl 3 -Δl 1 is satisfied where the dimensional variations caused by the temperature variation among said actuator, said first block, and said second block are -Δl 1 , Δl 2 , and Δl 3 , respectively.