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US 4,570,098 AGranted
Temperature compensated stack of piezoelectric elements
AssigneeNippon Soken, Inc.
InventorsMasahiro Tomita, Eturo Yasuda
Life of this patent
Estimating the term…
Abstract
A piezoelectric transducer comprising a lamination of piezoelectric elements including one or more elements in which the distortion has a positive temperature dependency and one or more elements in which the distortion has a negative temperature dependency. By selecting the ratio of the number of the piezoelectric elements having the positive and negative temperature dependencies, the temperature dependency of the distortion of a transducer can be eliminated. An actuator for injecting fuel into an automobile at a high speed and delicate response to external operation is provided.
Claims21
A piezoelectric transducer comprising:
- at least one piezoelectric element of a first type, having a distortion with a positive temperature dependency during application of a voltage thereto;
- at least one piezoelectric element of a second type, having a distortion with a negative temperature dependency during application of a voltage thereto;
- said piezoelectric elements of both said first and second types being arranged and laminated together to provide a laminated composite piezoelectric element means having a distortion which is less dependent on temperature during application of a voltage thereto than are said distortions of said first type of piezoelectric element and than are said distortions of said second type of piezoelectric element;
- and
- a plurality of electrodes operatively connected with said composite piezoelectric element means and being constructed and arranged for applying a distortion-producing voltage to said composite piezoelectric element.
2 more elements
An actuator, comprising:
- a piezoelectric transducer including:
- at least one piezoelectric element of a first type, having a distortion with a positive temperature dependency during application of a voltage thereto;
- at least one piezoelectric element of a second type, having a distortion with a negative temperature dependency during application of a voltage thereto;
- said piezoelectric elements of both said first and second types being arranged and laminated together to provide a laminated composite piezoelectric element means having a distortion which is less dependent on temperature during application of a voltage thereto than are said distortions of said first type of piezoelectric element and than are said distortions of said second type of piezoelectric element;
- and
- a plurality of electrodes operatively connected with said composite piezoelectric element means and being constructed and arranged for applying a distortion-producing voltage to said composite piezoelectric element;
- wall means defining a chamber having a fluid outlet;
- said piezoelectric transducer being effectively communicated to said chamber so that voltage applied to said electrodes, by distortion of said composite piezoelectric element means, may eject fluid from said chamber through said outlet.
5 more elements
An actuator, comprising:
- a piezoelectric transducer including:
- at least one piezoelectric element of a first type, having a distortion with a positive temperature dependency during application of a voltage thereto;
- at least one piezoelectric element of a second type, having a distortion with a negative temperature dependency during application of a voltage thereto;
- said piezoelectric elements of both said first and second types being arranged and laminated together to provide a laminated composite piezoelectric element means having a distortion which is less dependent on temperature during application of a voltage thereto than are said distortions of said first type of piezoelectric element and than are said distortions of said second type of piezoelectric element;
- and
- a plurality of electrodes operatively connected with said composite piezoelectric element means and being constructed and arranged for applying a distortion-producing voltage to said composite piezoelectric element;
- a case containing said piezoelectric transducer as a drive means;
- a chamber defined in the case for containing fuel;
- an inlet port for fuel connected to the chamber;
- a nozzle for ejecting fuel out of the chamber to the outside of the actuator, the nozzle comprising a nozzle holder defining a part of the wall of the chamber and a nozzle plunger engaging the nozzle holder;
- the nozzle plunger being constructed and arranged to be driven by said piezoelectric transducer so as to form a gap between the nozzle plunger and the nozzle holder to eject fuel therethrough.
8 more elements
Dependencies are inferred from the claim text.